KR20250029801A - Laminated film - Google Patents

Abstract

A laminated film having a configuration in which a cured resin layer (A) and a cured resin layer (B) are sequentially laminated on at least one surface of a base film, wherein the cured resin layer (A) is a cured product of a curable resin composition (A') containing (A-a) a binder, and the cured resin layer (B) is a cured product of a curable resin composition (B') containing (X) a urethane (meth)acrylate and (Y) a compound having a cyclic siloxane skeleton. According to the present invention, in a laminated film having excellent practical repeated bending characteristics and scratch resistance, and further having an interference pattern that is difficult to be seen, it is possible to propose a laminated film having good antistatic properties, and further capable of achieving both antistatic properties and antifouling properties, and also having excellent wear resistance.

Description

Laminated film

The present invention relates to a laminated film having a base film and a cured resin layer, a laminated film having excellent abrasion resistance, repeated folding characteristics, and antistatic properties, and a laminated film having excellent antistatic properties, antifouling properties, and abrasion resistance.

Recently, there has been a trend toward the use of flexible substrates and flexible printed circuit boards in conjunction with the miniaturization and weight reduction of electronic devices, etc. In addition, along with this trend, there has been a trend toward an increase in the demand for flexibility in display applications. In addition, surface protection films for display screens used in such applications require not only surface protection properties such as high hardness, scratch resistance, contamination resistance, and wear resistance, but also high durability with respect to bending, and further performance improvement is desired.

For this reason, many proposals have been made recently regarding surface protection films to improve flexibility and bendability while maintaining high hardness and abrasion resistance.

For example, Patent Document 1 discloses a hard coating film having a hard coating layer formed on at least one surface of a transparent substrate, wherein the hard coating layer is formed in two or more layers, the elasticity modulus of the hard coating layer formed closest to the transparent substrate is higher than the elasticity modulus of the surface hard coating layer, and further, the content of inorganic fine particles in the hard coating layer formed closest to the transparent substrate is higher than the content of the surface hard coating layer.

In addition, Patent Document 2 discloses a method for producing a hard coating film, characterized in that an ultraviolet-curable paint (a) having an elongation of a cured coating film of 80% or more is applied onto a film substrate, and an ultraviolet-curable paint (b) having a pencil scratch value of 4H or more of the cured coating film is applied onto the ultraviolet-curable paint, and then ultraviolet irradiation is performed to form a cured coating film.

In addition, Patent Document 3 discloses a hard coating film having a substrate film and a hard coating layer and used as a surface material of a touch panel that satisfies specific conditions.

In this way, the development of flexible portable terminals whose image display screens (displays) can be folded or bent is progressing, and surface protection films used in image display screens of this type are also required to have practical repeatable bending performance (e.g., durability capable of repeatable bending 200,000 or more times) as well as practical abrasion resistance (e.g., no scratches when returned and forth 2,000 times with a 1 kg load using steel wool #0000).

In addition, recently, the demand for image display devices having liquid crystal displays such as smart phones and tablet terminals has been further expanding. In order to protect the screen display portion or image display body of these displays, a protective film coated on a base film is being used.

For the protective film of the screen display portion or image display body of a display, etc., plastic films such as triacetyl cellulose film, cycloolefin film, polyester film, acrylic film, polycarbonate film, and transparent polyimide film are used in terms of optical properties such as transparency. However, since these plastic films exhibit high electrical insulation, they are easily charged, and dust easily adheres to the surface.

Therefore, in order to form a coating layer having antistatic properties, several coating compositions containing a quaternary ammonium base-containing polymer have been proposed (Patent Documents 4 to 6).

Patent Document 4 describes a resin composition for forming a hard coating layer. This resin composition for forming a hard coating layer comprises a (meth)acrylic copolymer obtained by copolymerizing a vinyl group-containing monomer having a quaternary ammonium group and a (meth)acrylic monomer copolymerizable therewith; a polyurethane oligomer having a vinyl group of three or more functions; and an acrylic monomer having a vinyl group of two to six functions.

Patent Document 5 discloses an antistatic hard coating resin composition. The antistatic hard coating resin composition comprises: a compound having a (meth)acryloyl group; a polymer containing a quaternary ammonium base; acetone; and a mixed solvent with at least one alcohol selected from the group consisting of methanol, ethanol, and isopropyl alcohol.

Patent Document 6 discloses a surface-cured article comprising a substrate and a cured coating film formed on the surface thereof. The cured coating film contains a quaternary ammonium base-containing polymer and metal oxide fine particles having an average particle size of 5 to 500 nm.

Japanese Patent No. 4574766 Japanese Patent No. 4569807 Japanese Patent Publication No. 2021-7016 Japanese Patent Publication No. 2008-56872 Japanese Patent Publication No. 2013-91698 Japanese Patent Publication No. 2013-132784

The inventions described in the above patent documents 1 to 3 all have excellent surface hardness, but practical abrasion resistance is not sufficiently considered. Among them, in patent document 3, although a test for practical abrasion resistance is assumed, the flexibility of the hard coating layer is not assumed, so it is assumed that the repeated bending characteristics when assembled into a device are insufficient.

Additionally, depending on the required characteristics, there were cases where interference patterns were required to be difficult to see.

In addition, surface protection films used for purposes such as flexible displays may have interference patterns caused by various factors, and when interference patterns are created in the surface protection film, the appearance deteriorates and the visibility as a display deteriorates, which causes problems. For this reason, surface protection films sometimes require interference patterns that are difficult to see as a required characteristic.

In addition, the inventions described in the above patent documents 4 to 6 were all in a situation where it was difficult to achieve both antistatic properties and antifouling properties. In addition, depending on the required characteristics, there are cases where it is necessary for interference patterns to be difficult to be seen.

In addition, in the case of surface protection films for display screens such as displays, there is a tendency toward the use of flexible substrates or flexible printed circuit boards in conjunction with the miniaturization and weight reduction of electronic devices, and in addition to surface protection characteristics such as high hardness, scratch resistance, and contamination resistance, a high degree of durability with respect to bending properties is required. Recently, in addition to characteristics related to hardness such as abrasion resistance, wear resistance against elastic bodies such as rubber has also been required, and further improvement has been desired.

Therefore, the present invention aims to provide a novel laminated film that has excellent practical repeated bending characteristics and abrasion resistance, as well as excellent wear resistance, and is also difficult to show interference patterns (first task).

In addition, it is intended to propose a new laminated film that has the flexibility of an appropriate hard coating layer, excellent practical repeated bending characteristics and abrasion resistance, good antistatic properties, and yet is difficult to show interference patterns (second task).

In addition, the present invention proposes a new laminated film that is capable of achieving both antistatic and antifouling properties, has excellent wear resistance, is difficult to show interference patterns, and satisfies practical repeated bending characteristics and abrasion resistance (third task).

The present inventors, taking the above circumstances into consideration, have conducted repeated examinations and, as a result, have found that the first problem can be solved by providing a configuration in which a cured resin layer (A) and a cured resin layer (B) of a specific configuration are laminated, and have thus completed the present invention. That is, the present invention provides the following [1-1] to [1-18].

In addition, by having a configuration in which a cured resin layer (C), a cured resin layer (A), and a cured resin layer (B) of a specific configuration are laminated, it has been found that the second problem can be easily solved, and thus the present invention has been completed. That is, the present invention provides the following [2-1] to [2-16].

In addition, by having a configuration in which a cured resin layer (A) and a cured resin layer (D) of a specific configuration are laminated, it has been found that the above problem can be easily solved, and thus the present invention has been completed. That is, the present invention provides the following [3-1] to [3-16].

The gist of the present invention is as follows.

[1-1] A laminated film having a configuration in which a cured resin layer (A) and a cured resin layer (B) are sequentially laminated on at least one surface of a base film, wherein the cured resin layer (A) is a cured product of a curable resin composition (A') containing (a) a binder, (b) a crosslinking agent, and (c) particles, and wherein the cured resin layer (B) is a cured product of a curable resin composition (B') containing (X) a urethane (meth)acrylate and (Y) a compound having a cyclic siloxane skeleton, and (a) the binder contains a compound having a condensed polycyclic aromatic structure.

[1-2] (Y) A laminated film as described in [1-1], wherein the compound having a cyclic siloxane skeleton is a fluorine compound having a perfluoroether structure.

[1-3] A laminated film as described in [1-1] or [2-1], in which, when the following steel resistance test is performed on the surface of the cured resin layer (B), the rate of change in film haze after 2000 round trips is less than 1%;

(Nestle Wool Test)

The uppermost surface of the cured resin layer (B) is rubbed 2,000 times at a speed of 50 mm/sec while applying a load of 1 kg in a 2 cm by 2 cm dimension using #0000 steel wool in a friction tester, and the haze value of the laminated film before and after the friction is measured, and the rate of change from the initial film haze (film haze before friction) is calculated.

Change rate (%) = (film haze after friction - initial film haze) / initial film haze × 100

[1-4] A laminated film as described in any one of [1-1] to [1-3], wherein the number of repeated bendings in the repeated bending test is 200,000 or more;

(Repeated bending test)

Using a bending tester, a bending test is performed with a minimum radius R=1.5 so that the cured resin layer side of the laminated film becomes the inner surface, and the presence or absence of cracks in the cured resin layer on the inner surface is visually confirmed, and the number of repeated bends until cracks occur is measured.

[1-5] A laminated film as described in any one of [1-1] to [1-4], having a film haze of 1.0% or less.

[1-6] A laminated film according to any one of [1-1] to [1-5], wherein the elongation at break of the cured resin layer (A) and the cured resin layer (B) is 0.5% or more.

[1-7] A laminated film as described in any one of [1-1] to [1-6], wherein the light transmittance at a wavelength of 380 nm on the surface of the cured resin layer (B) is 3% or less.

[1-8] A laminated film as described in any one of [1-1] to [1-7], wherein the substrate film contains an ultraviolet absorber.

[1-9] (c) A laminated film as described in any one of [1-1] to [1-8], comprising two types of particles having different particle sizes.

[1-10] A laminated film as described in any one of [1-1] to [1-9], wherein the compound having a condensed polycyclic aromatic structure is a polyester resin having a condensed polycyclic aromatic structure.

[1-11] A laminated film as described in any one of [1-1] to [1-10], wherein the substrate film is a polyester film.

[1-12] A laminated film as described in any one of [1-1] to [1-11], wherein the substrate film is a polyethylene terephthalate (PET) film.

[1-13] A laminated film as described in [1-11] or [1-12], having a retardation (Re) of 1400 nm or less when light having a wavelength of 590 nm is incident on a polyester film surface at an angle of 0°.

[1-14] A laminated film as described in any one of [1-11] to [1-13], wherein the change in retardation (Re) in the direction of the forward axis is 10 nm or more and 600 nm/m or less when light having a wavelength of 590 nm is incident on a polyester film surface at an angle of 0°.

[1-15] A laminated film according to any one of [1-1] to [1-14], wherein the thickness of the cured resin layer (B) is 10.0 ㎛ or less.

[1-16] A laminated film as described in any one of [1-1] to [1-15] for surface protection.

[1-17] A laminated film for display purposes, described in any one of [1-1] to [1-16].

[1-18] A laminated film described in any of [1-1] to [1-17] for the front panel.

[2-1] A laminated film having a structure in which a cured resin layer (A), a cured resin layer (B), and a cured resin layer (C) are sequentially laminated on at least one surface of a base film, wherein the cured resin layer (A) is a cured product of a curable resin composition A containing an antistatic agent, the cured resin layer (B) is a cured product of a curable resin composition (B') containing (B-a) a binder, and the cured resin layer (C) is a cured product of a curable resin composition (C') containing (X) a urethane (meth)acrylate and (Y) a fluorine compound having a cyclic siloxane skeleton and a perfluoroether structure.

[2-2] A laminated film as described in [2-1] above, in which, when a steel-resistant test is performed on the surface of the cured resin layer (C), the rate of change in film haze after 2000 round trips is less than 1%;

(Nestle Wool Test)

The surface of the cured resin layer (C) is rubbed 2000 times back and forth at a speed of 50 mm/sec while applying a load of 1 kg in a 2 cm by 2 cm dimension using #0000 steel wool in a friction tester, and the haze value of the laminated film before and after the friction is measured, and the rate of change from the initial film haze (film haze before friction) is calculated.

Change rate (%) = (film haze after friction - initial film haze) / initial film haze × 100

[2-3] A laminated film described in [2-1] or [2-2], which can be folded 200,000 times or more in a repeated bending test (under the condition of internal bending, R=1.5).

(Repeated bending test)

Using a bending tester, a bending test is performed with a minimum radius R=1.5 so that the cured resin layer side of the laminated film becomes the inner surface, and the presence or absence of cracks in the cured resin layer on the inner surface is visually confirmed, and the number of repeated bends until cracks occur is measured.

[2-4] A laminated film according to any one of [2-1] to [2-3], having a film haze of 1.0% or less.

[2-5] A laminated film according to any one of [2-1] to [2-4], wherein the light transmittance at a wavelength of 380 nm of the surface of the cured resin layer (C) is 3% or less.

[2-6] A laminated film according to any one of [2-1] to [2-5], wherein the maximum reflectivity difference at a wavelength of 500 to 600 nm on the surface of the cured resin layer (C) is 1.5% or less.

[2-7] A laminated film as described in any one of [2-1] to [2-6], wherein the above-mentioned substrate film contains an ultraviolet absorber.

[2-8] A laminated film according to any one of [2-1] to [2-7], wherein the cured resin layer (B) includes (B-c) particles, and the (B-c) particles are two types of particles having different particle sizes.

[2-9] A laminated film as described in any one of [2-1] to [2-8], wherein the above-mentioned substrate film is a polyester film.

[2-10] A laminated film as described in any one of [2-1] to [2-9], wherein the above-mentioned substrate film is a polyethylene terephthalate (PET) film.

[2-11] A laminated film as described in [2-9] or [2-10], wherein the retardation (Re) of the polyester film is 1400 nm or less.

[2-12] A laminated film according to any one of [2-9] to [2-11], wherein the variation in retardation (Re) in the width direction of the polyester film is 10 nm/m or more and 600 nm/m or less.

[2-13] A laminated film according to any one of [2-1] to [2-12], wherein the thickness of the cured resin layer (C) is 10.0 ㎛ or less.

[2-14] A laminated film described in any one of [2-1] to [2-13] above for surface protection.

[2-15] A laminated film for display purposes, as described in [2-14] above.

[2-16] A laminated film for the front panel, as described in [2-15] above.

[3-1] A laminated film having a structure in which a cured resin layer (A) and a cured resin layer (D) are sequentially laminated on at least one surface of a substrate film, wherein the cured resin layer (A) is a cured product of a curable resin composition (A') containing (A-a) a binder, (A-b) a crosslinking agent, and (A-c) particles, and wherein the cured resin layer (D) is a cured product of a curable resin composition (D') containing (D-a) a trifunctional or higher (meth)acrylate, (D-b) a quaternary ammonium base-containing polymer, and (D-c) a compound having a fluorine atom-containing structure and a cyclic siloxane structure.

[3-2] A laminated film as described in [3-1], wherein, when the following steel-resistant test is performed on the surface of the cured resin layer (D), the rate of change in film haze after 1000 round trips is less than 1%.

(Nestle Wool Test)

The uppermost surface of the cured resin layer (D) is rubbed 1000 times back and forth at a speed of 50 mm/sec while applying a load of 1 kg in a 2 cm by 2 cm dimension using #0000 steel wool in a friction tester, and the haze value of the laminated film before and after the friction is measured, and the rate of change from the initial film haze (film haze before friction) is calculated.

Change rate (%) = (film haze after friction - initial film haze) / initial film haze × 100

[3-3] A laminated film as described in [3-1] or [3-2] above, having a film haze of 1.0% or less.

[3-4] A laminated film according to any one of [3-1] to [3-3], wherein the light transmittance at a wavelength of 380 nm on the surface of the cured resin layer (D) is 3% or less.

[3-5] A laminated film according to any one of [3-1] to [3-4], wherein the maximum reflectivity difference at a wavelength of 500 to 600 nm on the surface of the cured resin layer (D) is 1.5% or less.

[3-6] A laminated film according to any one of [3-1] to [3-5], wherein the substrate film contains an ultraviolet absorber.

[3-7] A laminated film as described in any one of [3-1] to [3-6], wherein the above (A-c) particles are two types of particles having different particle sizes.

[3-8] A laminated film according to any one of [3-1] to [3-7], wherein the (A-a) binder comprises a compound having a condensed polycyclic aromatic structure.

[3-9] A laminated film according to any one of [3-1] to [3-8], wherein the above-mentioned substrate film is a polyester film.

[3-10] A laminated film as described in any one of [3-1] to [3-9], wherein the above-mentioned substrate film is a polyethylene terephthalate (PET) film.

[3-11] A laminated film as described in [3-9], wherein the retardation (Re) of the polyester film is 1400 nm or less.

[3-12] A laminated film as described in [3-9], wherein the variation in retardation (Re) in the width direction of the polyester film is 10 nm/m or more and 600 nm/m or less.

[3-13] A laminated film according to any one of [3-1] to [3-12], wherein the thickness of the cured resin layer (D) is 10.0 ㎛ or less.

[3-14] A laminated film described in any one of [3-1] to [3-13] above for surface protection.

[3-15] A laminated film for display purposes, described in any one of [3-1] to [3-14] above.

[3-16] A laminated film for the front panel, described in any one of [3-1] to [3-15] above.

According to the present invention, it is possible to provide a laminated film having excellent practical repeated bending characteristics and abrasion resistance, and also in which interference patterns are difficult to be seen.

In addition, it is possible to propose a laminated film having flexibility of an appropriate hard coating layer, excellent practical repeated bending characteristics and abrasion resistance, good antistatic properties, and also having a low interference pattern visibility.

Furthermore, it is possible to propose a laminated film that is both antistatic and antifouling, has a low visibility of interference patterns, has excellent wear resistance, and satisfies practical repeated bending characteristics and abrasion resistance.

Figure 1 is a cross-sectional view illustrating the configuration of a laminated film.

Next, the present invention will be described based on embodiments. However, the present invention is not limited to the embodiments described below.

The laminated film of the present invention has a configuration in which a cured resin layer (A) and a cured resin layer (B) are sequentially laminated on at least one surface of a base film, wherein the cured resin layer (A) is a cured product of a curable resin composition (A') containing (A-a) a binder, and the cured resin layer (B) is a cured product of a curable resin composition (B') containing (X) a urethane (meth)acrylate and (Y) a compound having a cyclic siloxane skeleton.

Below, three embodiments are described in detail.

[Embodiment 1]

A laminated film according to the first embodiment of the present invention has a configuration in which a cured resin layer (A) and a cured resin layer (B) are sequentially laminated on at least one surface of a base film (hereinafter, sometimes referred to as “the present base film”). The cured resin layer (A) is a cured product of a curable resin composition (A') containing (A-a) a binder, (A-b) a crosslinking agent, and (A-c) particles, and the cured resin layer (B) is a cured product of a curable resin composition (B') containing (X) a urethane (meth)acrylate and (Y) a compound having a cyclic siloxane skeleton. Furthermore, the binder (A-a) contained in the cured resin layer (A) contains a compound having a condensed polycyclic aromatic structure.

In addition, the present laminated film may have other layers as long as it has the above configuration.

Fig. 1 is a cross-sectional view illustrating the configuration of the present laminated film. As shown in Fig. 1, the laminated film (10) has a base film (2), and has a cured resin layer (A) (4) and a cured resin layer (B) (6) in that order on the base film (2). In Fig. 1, a configuration in which a cured resin layer (A) (4) and a cured resin layer (B) (6) are sequentially provided on one surface of the base film (2) is illustrated, but the cured resin layer (A) (4) and the cured resin layer (B) (6) may be provided on both surfaces of the base film (2). In addition, different layers may be provided between the substrate film (2) and the cured resin layer (A) (4), and between the cured resin layer (A) (4) and the cured resin layer (B) (6), but it is preferable that the substrate film (2) and the cured resin layer (A) (4), and the cured resin layer (A) (4) and the cured resin layer (B) (6) are laminated so as to be in direct contact.

Since the laminated film of the present invention has the above configuration, it has excellent practical repeated bending characteristics (bending resistance) and abrasion resistance. In the laminated film of the present invention, a cured resin layer (A) and a cured resin layer (B) are sequentially laminated on at least one surface of a base film, and since the cured resin layer (B) is a cured product formed by curing a curable resin composition containing (X) a urethane acrylate and (Y) a compound having a cyclic siloxane skeleton, the cured resin layer has flexibility, and at the same time, it is possible to achieve a high level of abrasion resistance (for example, 2,000 times or more in terms of SW resistance) and repeated bending resistance (can be bent 200,000 times under the condition of R = 1.5). It is presumed that the compound having a (Y) cyclic siloxane skeleton of the cured resin layer (B) is different from a conventional particle additive system and can improve the sliding properties of the surface of the cured resin layer, and as a result, since it can smoothly receive and pass over pressure from the outside with less resistance, the abrasion resistance of the laminated film is improved.

In addition, since the laminated film of the present invention has the above configuration, the occurrence of interference fringes is suppressed. In the laminated film of the present invention, a cured resin layer (A) and a cured resin layer (B) are sequentially laminated on at least one surface of a base film, and since the cured resin layer (A) and the cured resin layer (B) having a predetermined composition are sequentially laminated, optical interference is reduced, and the occurrence of interference fringes is suppressed. The occurrence of interference fringes tends to occur more easily when the refractive index difference between the base film and the cured resin layer is large. In the present invention, by containing particles in the cured resin layer (A), the refractive index difference between the base film and the cured resin layer (A) is reduced, and by using a compound having a specific structure as the (A-a) binder included in the curable resin composition (A'), the occurrence of interference fringes can be suppressed.

Hereinafter, the laminated film related to the first embodiment of the present invention will be described in more detail.

<Film>

The laminated film of the present invention has a base film. The base film is not limited to a material and composition as long as it is a film that can obtain necessary and sufficient rigidity and repeated bending properties. However, in terms of having appropriate flexibility, practical repeated bending properties, and excellent abrasion resistance, it is preferably a polyester film or a polyimide film, more preferably a polyester film, and particularly preferably a polyethylene terephthalate (PET) film.

The substrate film may have a single-layer configuration or a multi-layer configuration.

When the substrate film has a multilayer structure, in addition to a two-layer or three-layer structure, it may have four or more layers as long as it does not exceed the gist of the present invention. In a preferred embodiment, the substrate film has a multilayer structure, and a three-layer structure is particularly preferred.

Even if the substrate film has a single-layer or multi-layer configuration, it is preferable that the main component resin of each layer is polyester or polyimide (PI). A film whose main component resin is polyester or polyimide is called a “polyester film” or a “polyimide film.”

At this time, the "main component resin" means the resin having the largest content ratio among the resins constituting the base film. The content of the main component resin is preferably 50 mass% or more, more preferably 70 mass% or more, and even more preferably 80 mass% or more, with respect to the total mass of the resin constituting the base film. In addition, the content of the main component resin may be 100 mass% of the resin constituting the base film.

In addition, each layer constituting the base film may contain a resin other than polyester or polyimide, or a component other than a resin, if the main component resin is polyester or polyimide.

(polyester)

The polyester (hereinafter referred to as “this polyester”) as the main component resin constituting the base film may be either a homopolyester or a copolymerized polyester.

When the present polyester is composed of a homopolyester, the present polyester is preferably obtained by polycondensation of an aromatic dicarboxylic acid and an aliphatic glycol. Examples of the aromatic dicarboxylic acid include terephthalic acid and 2,6-naphthalenedicarboxylic acid. Examples of the aliphatic glycol include ethylene glycol, diethylene glycol, and 1,4-cyclohexanedimethanol.

In addition, when the present polyester is a copolymerized polyester, it is preferable that it is a copolymer containing a third component of 30 mol% or less. As the dicarboxylic acid component of the copolymerized polyester, examples thereof include isophthalic acid, phthalic acid, terephthalic acid, 2,6-naphthalenedicarboxylic acid, and sebacic acid. On the other hand, as the glycol component, examples thereof include ethylene glycol, diethylene glycol, propylene glycol, butanediol, 1,4-cyclohexanedimethanol, and neopentyl glycol. As these third components, one or more types may be used.

As a polymerization catalyst for condensation of polyester, known catalysts such as antimony compounds, germanium compounds, titanium compounds, and aluminum compounds can be used. Among these, in the present invention, it is preferable to use at least one selected from antimony compounds and titanium compounds as a catalyst.

Specific examples of typical polyesters include, for example, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polybutylene terephthalate (PBT), polybutylene naphthalate (PBN), and polyethylene furanoate (PEF). Among them, PET and PEN are preferable from the viewpoint of ease of handling, and PET is most preferable.

In addition, when the main component resin constituting the base film is, for example, polyethylene terephthalate, the film is called a "polyethylene terephthalate film." The same applies when another resin is the main component resin.

(polyimide)

As the base film, in addition to a polyester film, a polyimide film is also preferable. Regarding the imidization of polyimide, an example is a method in which a diamine and a dianhydride, particularly an aromatic dianhydride and an aromatic diamine, are polymerized with polyamic acid at an equivalent ratio of 1:1, and then imidized.

Examples of aromatic dianhydrides include 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride (6FDA), 4-(2,5-dioxotetrahydrofuran-3-yl)-1,2,3,4-tetrahydronaphthalene-1,2-dicarboxylic dianhydride (TDA), pyromellitic dianhydride (1,2,4,5-benzenetetracarboxylic dianhydride, PMDA), benzophenonetetracarboxylic dianhydride (BTDA), biphenyltetracarboxylic dianhydride (BPDA), and biscarboxyphenyldimethylsilane dianhydride (SiDA). These may be used alone or in combination of two or more.

In addition, examples of aromatic diamines include oxydianiline (ODA), p-phenylenediamine (pPDA), m-phenylenediamine (mPDA), p-methylenedianiline (pMDA), m-methylenedianiline (mMDA), bistrifluoromethylbenzidine (TFDB), cyclohexanediamine (13CHD, 14CHD), bisaminohydroxyphenylhexafluoropropane (DBOH), etc. These may be used alone or in combination of two or more.

(Other resin components)

The main component resin of each layer constituting the base film is preferably polyester or polyimide (PI), but the base film may have a layer whose main component resin is a resin other than polyester and polyimide. Examples of the main component resin in that case include epoxy resins, polyarylates, polyethersulfones, polycarbonates, polyether ketones, polysulfones, polyphenylene sulfides, polyester liquid crystal polymers, triacetyl cellulose, cellulose derivatives, polypropylene, polyamides, and polycycloolefins.

(particle)

The base film may contain particles for the purpose of providing slipperiness to the film surface and preventing scratches during each process.

The type of the particle is not particularly limited as long as it is a particle capable of imparting activity. Examples thereof include inorganic particles such as silica, calcium carbonate, magnesium carbonate, barium carbonate, calcium sulfate, calcium phosphate, magnesium phosphate, kaolin, aluminum oxide, and titanium oxide; and organic particles such as acrylic resin, styrene resin, urea resin, phenol resin, epoxy resin, and benzoguanamine resin. These may be used alone or in combination of two or more of these.

Additionally, as particles, precipitated particles obtained by precipitating and microdispersing a portion of a metal compound such as a catalyst during a polyester manufacturing process may also be used.

The shape of the above particles is not particularly limited. For example, it may be any shape such as spherical, block-shaped, rod-shaped, or flat.

In addition, there are no special restrictions on the hardness, specific gravity, color, etc. of the particles. These series of particles may be used in combination of two or more types as needed.

The average particle size of the above particles is preferably 5 µm or less, more preferably 3 µm or less, and even more preferably 2.5 µm or less. By setting the average particle size of the particles to the upper limit or less, the surface roughness of the base film can be kept within an appropriate range, and problems can be prevented from occurring when forming a cured resin layer made of various curing compositions in a post-process. Meanwhile, the average particle size of the above particles is preferably 0.01 µm or more, and even more preferably 0.5 µm or more.

The content of particles is preferably 5 mass% or less, more preferably 3 mass% or less, and even more preferably 2 mass% or less, relative to the total mass of the base film. In addition, the content of particles is preferably 0.0003 mass% or more, more preferably 0.001 mass% or more, and even more preferably 0.01 mass% or more, relative to the total mass of the base film. When the average particle diameter is within the above range, the surface roughness of the base film can be made within an appropriate range, and problems can be prevented from occurring, such as when forming a cured resin layer made of various curing compositions in a post-process.

There is no particular limitation on the method for adding particles to the base film, and a conventionally known method can be adopted. For example, it can be added at any stage of manufacturing a raw material resin such as polyester. When the base film is polyester, it is preferable to add it after the esterification or ester exchange reaction is completed.

(Other ingredients)

The base film may contain, if necessary, other components such as conventionally known antioxidants, antistatic agents, heat stabilizers, lubricants, dyes, pigments, ultraviolet absorbers, etc. In particular, in order to secure the weather resistance of the present laminated film, it is preferable that the base film contain an ultraviolet absorber.

(thickness)

The thickness of the substrate film is preferably 9 µm or more, more preferably 12 µm or more, even more preferably 15 µm or more, and particularly preferably 20 µm or more, in terms of being able to obtain necessary and sufficient rigidity and repeatable bending properties. In addition, the thickness of the substrate film is preferably 125 µm or less, more preferably 100 µm or less, and even more preferably 75 µm or less. In addition, when the substrate film has a multilayer configuration, it is preferable that the total thickness of all layers is within the above range.

(Method for manufacturing substrate film)

The base film can be formed, for example, by a melt film forming method or a solution film forming method using a resin composition. In the case of a multilayer structure, coextrusion may be used.

In addition, the base film may be a uniaxially stretched or biaxially stretched film, and from the viewpoint of rigidity, a biaxially stretched film is preferable.

Hereinafter, a method for manufacturing a polyester film as an example of a base film will be described. Generally, first, by a known method, undried or dried polyester chips are supplied to a melting extrusion device, and each polymer is heated to a temperature higher than the melting point to melt it. Next, the molten polymer is extruded from a die, rapidly cooled on a rotary cooling drum to a temperature lower than the glass transition temperature, and solidified, thereby obtaining a substantially amorphous, unoriented sheet. In this case, in order to improve the flatness of the sheet, it is preferable to increase the adhesion between the sheet and the rotary cooling drum, and in the present invention, an electrostatically applied adhesion method and/or a liquid application adhesion method are preferably employed.

It is preferable from the viewpoint of the strength of the film to stretch the sheet obtained as described above in two directions to form a film. Specifically speaking about the stretching conditions, the unstretched sheet is stretched, preferably in the longitudinal direction (machine direction), at a stretching ratio of 2.0 to 4.5 times, preferably 3.0 to 4.0 times, at a temperature of 70 to 145°C, preferably 80 to 120°C, to form a uniaxially stretched film.

Next, stretching is performed in the transverse direction (width direction), which is orthogonal to the longitudinal direction (machine direction), at a temperature of 90 to 160°C and a stretching ratio of 3.0 to 6.5 times and 3.5 to 6.0 times, to form a biaxially stretched film.

Next, it is preferable to perform heat treatment (heat setting) at 210 to 260°C for 10 to 600 seconds under tension or within 30% relaxation. And, it is preferable to relax by 1 to 10% in the longitudinal and/or transverse directions in the highest temperature zone of the heat treatment and/or the cooling zone of the heat treatment exit.

In addition, when it is desired to suppress the retardation (hereinafter, sometimes simply referred to as “Re”) of the base film, with regard to the stretching ratio described above, the difference between the longitudinal and transverse stretching ratios is preferably smaller, and the difference is preferably 0.5 times or less, and more preferably 0.3 times or less. In addition, the heat treatment temperature is also preferably lower, and is preferably 200°C or less, more preferably 180°C or less, and even more preferably 160°C or less. By satisfying the above range, it is possible to obtain a base film having Re at a certain level or less, regardless of the sampling position in the film width direction.

In addition, the longitudinal direction (machine direction) of the film refers to the direction in which the film progresses in the film manufacturing process, that is, the winding direction of the film roll. The transverse direction (width direction) refers to the direction parallel to the film plane and orthogonal to the length direction, that is, the direction parallel to the central axis of the roll when the film is in the shape of a roll.

(Characteristics of the film)

The tensile modulus of elasticity (JIS K 7161:2014) of the base film is preferably 2.0 GPa or more, more preferably 2.5 GPa or more, and even more preferably 3.0 GPa or more, in order to obtain necessary and sufficient rigidity and repeatable bending properties. In addition, the tensile modulus of elasticity of the base film is preferably 9.0 GPa or less, more preferably 8.0 GPa or less, and even more preferably 7.0 GPa or less.

(Retardation (Re))

When light having a wavelength of 590 nm is incident on the substrate film, particularly the polyester film surface, the retardation (Re) is preferably 1400 nm or less, more preferably 1200 nm or less, and particularly preferably 1000 nm or less. When light having a wavelength of 590 nm is incident on the polyester film surface at an angle of 0°, the retardation (Re) is preferably closer to 0, but may be 50 nm or more, or even 100 nm or more.

When light having a wavelength of 590 nm is incident on a polyester film surface at an angle of 0°, the change in retardation (Re) in the true axis direction (width direction) is preferably 5 nm/m or more, more preferably 10 nm/m or more, still more preferably 20 nm/m or more, and particularly preferably 50 nm/m or more.

In addition, when light having a wavelength of 590 nm is incident on the polyester film surface at an angle of 0°, the change in retardation (Re) in the true axis direction (width direction) is preferably 600 nm/m or less, and more preferably 550 nm/m or less.

Here, when light having a wavelength of 590 nm is incident at an angle of 0° on the polyester film surface, the amount of change in retardation (Re) in the direction of the true axis (in the width direction) is calculated by calculating the difference between the maximum and minimum retardation values obtained by a 3.5 cm × 3.5 cm film sample, and dividing the difference by the distance (m) in the direction of the true axis (in the width direction) of the positions in the film sample where the maximum and minimum values were obtained. Specifically, it is calculated by the following equation.

The change in retardation (Re) in the direction of the true axis (in the width direction) (㎚/m) = (maximum value of retardation - minimum value of retardation) / distance between the maximum value and the minimum value in the direction of the true axis (in the width direction) (m)

Additionally, the width of the range satisfying the above-described Re condition is preferably 50% or more of the entire film width, more preferably 55% or more, and particularly preferably 60% or more. Furthermore, the width of the range satisfying the above-described Re condition may be 100% of the entire film width.

In particular, it is preferable that the range in which the amount of variation in the retardation (Re) in the true axis direction (width direction) per 1 m width is 10 to 600 nm/m is 50% or more, more preferably 60% or more, and even more preferably 70% or more, of the entire film width. By setting the ratio of the range in which the amount of variation in the retardation (Re) in the true axis direction (width direction) is 10 to 600 nm/m within the above range, for example, in a wide-width film corresponding to a large-screen display of 40 inches or more, preferably 50 inches or more, the vibration range of the retardation within the film plane can be suppressed, and when used in combination with various light sources, it becomes possible to reduce the occurrence of rainbow spots.

<Curing resin layer (A) and curing resin layer (B)>

The laminated film of the present invention has a cured resin layer (A) and a cured resin layer (B). The laminated film has a laminated configuration in which a cured resin layer (A) is provided on at least one surface of a base film, and a cured resin layer (B) is additionally provided on the surface side thereof. The cured resin layer (A) is a cured product of a curable resin composition (A') containing (A-a) a binder, (A-b) a crosslinking agent, and (A-c) particles, and the cured resin layer (B) is a cured product of a curable resin composition (B') containing (X) a urethane (meth)acrylate and (Y) a compound having a cyclic siloxane skeleton.

The thickness of the cured resin layer (A) is preferably 1.0 µm or less, more preferably 0.6 µm or less, still more preferably 0.4 µm or less, and particularly preferably 0.2 µm or less. The lower limit of the thickness of the cured resin layer (A) is not particularly limited, but is preferably, for example, 0.01 µm or more, and preferably 0.03 µm or more.

The thickness of the cured resin layer (B) is preferably 10.0 µm or less, more preferably 8.0 µm or less, still more preferably 6.0 µm or less, and particularly preferably 5.0 µm or less. The lower limit of the thickness of the cured resin layer (B) is not particularly limited, but is, for example, preferably 1.0 µm or more. By making the thickness of the cured resin layer (B) equal to or greater than the lower limit, the base film can be appropriately protected by the cured resin layer (B). In addition, by making the thickness of the cured resin layer (B) equal to or less than the upper limit, curling or thermal wrinkles can be prevented in the laminated film having the cured resin layer (B), thereby ensuring good flatness.

In addition, from the viewpoint of bendability, the total thickness of the cured resin layer (A) and the cured resin layer (B) is preferably 10.0 µm or less, more preferably 8.0 µm or less, further preferably 6.0 µm or less, and particularly preferably 5.0 µm or less. The lower limit of the total thickness of the cured resin layer (A) and the cured resin layer (B) is not particularly limited, but is preferably 1.0 µm or more, for example.

The thickness of each of the cured resin layer (A) and the cured resin layer (B) can be measured, for example, using a SAICS (DN-01 type, manufactured by Daipla Wintes). Specifically, first, a laminated film having the cured resin layer (A) and the cured resin layer (B) is adhered onto a glass slide glass using "Alon Alpha Series" manufactured by Dong-A Synthetic Co., Ltd. to prepare a SAICS sample. The obtained SAICS sample is set on a SAICS (DN-01 type, manufactured by Daipla Wintes), and a slit with a width of 300 µm and a depth of 1 µm is made in advance using a diamond blade (a single crystal diamond blade with a V-angle dimension of 80°, an inclination angle of 5°, and a relief angle of 5° is used for the slit). The measurement is performed by setting a 300 ㎛ wide borazone blade on a sample with a 300 ㎛ wide slit in advance, and measuring the film thickness of each cured resin layer at an arbitrary depth, a horizontal speed of 1 ㎛/s, and a vertical speed of 0.5 ㎛/s (for the measurement, a boron nitride blade with a blade width of 0.3 mm, an inclination angle of 20°, and a relief angle of 10° is used). The material strength is measured from the vertical displacement position and cutting force, and the thickness of each layer is calculated.

The light transmittance at a wavelength of 380 nm of the surface of the cured resin layer (B) is preferably 3.0% or less, and more preferably 2.8% or less. The lower limit of the light transmittance at a wavelength of 380 nm of the surface of the cured resin layer (B) is not particularly limited, and may be 0%. By setting the light transmittance at a wavelength of 380 nm of the surface of the cured resin layer (B) within the above range, the partner member to be bonded can be prevented from deteriorating due to ultraviolet rays. For the measurement of the light transmittance at a wavelength of 380 nm, a spectrophotometer (U-3900H, manufactured by Hitachi High-Technologies Co., Ltd.) can be used, for example.

The absolute reflectivity of the surface of the cured resin layer (B) at a wavelength of 550 nm is preferably 1% or more, more preferably 2% or more, and still more preferably 3% or more. In addition, the absolute reflectivity of the surface of the cured resin layer (B) at a wavelength of 550 nm is preferably 10% or less, more preferably 8% or less, and still more preferably 6% or less. By setting the absolute reflectivity of the surface of the cured resin layer (B) at a wavelength of 550 nm within the above range, it also becomes possible to impart anti-glare properties when used as a cover film for a display screen.

The absolute reflectance at a wavelength of 550 nm of the surface of the cured resin layer (B) is a value measured by the following method. First, a black tape is attached to the side of the laminated film on which the cured resin layer is not laminated, and the absolute reflectance at a wavelength of 550 nm of the side of the cured resin layer is measured using a spectrophotometer. The absolute reflectance is calculated as the ratio of the amount of light reflected from the surface of the cured resin layer of the laminated film to the amount of light measured directly from a light source without using a reference plate.

Absolute Reflectance (%) = Amount of light reflected from the cured resin layer of the laminated film / Amount of light used × 100

In addition, the cured resin layer (B) may have its refractive index adjusted in advance so as to be difficult to affect optical interference. For example, if the refractive index is a low-refractive layer of about 1.53, by adopting a composition of the cured resin layer (B) that can achieve the low refractive index, it becomes possible to achieve both the desired abrasion resistance and repeated bending properties.

The refractive index of the cured resin layer (B) is preferably 1.46 to 1.60, more preferably 1.49 to 1.57, from the viewpoint of reducing interference unevenness.

The elongation at break of the cured resin layer (A) and the cured resin layer (B) (hereinafter, the cured resin layer (A) and the cured resin layer (B) are collectively referred to as the cured resin layer) is preferably 0.5% or more, more preferably 1.0% or more, and even more preferably 1.5% or more. In addition, the elongation at break of the cured resin layer is preferably 3.0% or less, more preferably 2.5% or less, and even more preferably 2.0% or less. By setting the elongation at break of the cured resin layer within the above range, it becomes easy to obtain a laminated film having excellent practical repeated bending characteristics (bending resistance).

In addition, the elongation at break here is the value of the cured resin layer that laminates the cured resin layer (A) and the cured resin layer (B).

The elongation at break of the cured resin layer is a value measured by the following method. First, a laminated film in which a cured resin layer (A) and a cured resin layer (B) are sequentially laminated on the surface of a base film is cut into a strip shape having a width of 10 mm and a length of 150 mm to make a test piece, and the test piece is inserted into the chuck of a tensile tester so that the initial chuck distance is 50 mm. Then, the sample is tensioned at a tensile speed of 5 m/min, and the displacement at which a crack occurs in the cured resin layer is visually confirmed, and the elongation is calculated by the following formula.

Elongation (%) = (length at break - initial length) / initial length × 100

(Surface condition of each layer)

The surface of the cured resin layer (A) may be uneven or flat, but from the perspective of appearance (surface gloss), it is preferable that it be flat.

In addition, the surface of the cured resin layer (B) may be either uneven or flat, but from the viewpoint of appearance (surface gloss), it is preferable to be flat. On the other hand, from the viewpoint of imparting anti-glare properties, it is preferable to be uneven. Depending on the required characteristics, it can be arbitrarily selected.

<Curable resin composition>

The curable resin composition (A') and the curable resin composition (B') for forming the curable resin layer (A) and the curable resin layer (B) are described below.

(Curable resin composition (A'))

The curable resin composition (A') contains a binder (A-a), and preferably further contains a crosslinker (A-b) and particles (A-c). Each component is described in detail below.

(A-a) Binder

As the (A-a) binder used in the curable resin composition (A'), a resin is used. Examples of the resin constituting the binder include polyester resins, acrylic resins, urethane resins, etc. In addition, as the binder, polyvinyl (polyvinyl alcohol, polyvinyl chloride, vinyl chloride acetate copolymer, etc.), polyalkylene glycol, polyalkylene imine, methyl cellulose, hydroxy cellulose, starch, etc. may be used together. Among these binders, it is preferable to use at least one selected from the group consisting of polyester resins, acrylic resins, and polyurethane resins, and it is more preferable to use a polyester resin.

(A-a) The content of the binder is preferably 1 to 90 mass%, more preferably 3 to 85 mass%, and even more preferably 5 to 80 mass%, based on the total nonvolatile component content (total solid content) in the curable resin composition (A'). By setting the content of the binder within the above range, good film-forming properties can be secured.

(polyester resin)

Polyester resins are made by condensing polycarboxylic acids and polyhydroxy compounds, such as the following, as main components. That is, as polycarboxylic acids, terephthalic acid, isophthalic acid, orthophthalic acid, phthalic acid, 4,4'-diphenyldicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 2-potassium sulfoterephthalic acid, 5-sodium sulfoisophthalic acid, 2,6-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, glutaric acid, succinic acid, trimellitic acid, trimesic acid, pyromellitic acid, trimellitic anhydride, phthalic anhydride, p-hydroxybenzoic acid, trimellitic acid monopotassium salt, and their ester-forming derivatives can be used. As the polyhydroxy compounds, ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, 2-methyl-1,5-pentanediol, neopentyl glycol, 1,4-cyclohexanedimethanol, p-xylylene glycol, bisphenol A-ethylene glycol adduct, diethylene glycol, triethylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polytetramethylene oxide glycol, dimethylolpropionic acid, glycerin, trimethylolpropane, sodium dimethylol ethyl sulfonate, potassium dimethylolpropionate, etc. can be used. From these compounds, one or more can be appropriately selected, and a polyester resin can be synthesized by a polycondensation reaction using a general method.

(Acrylic resin)

As for the acrylic resin, there is no particular limitation, and it may be appropriately selected within the range of the effect of the present invention, and for example, (meth)acrylate is preferable.

Examples of monofunctional (meth)acrylates include alkyl (meth)acrylates such as methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and lauryl (meth)acrylate; hydroxyl group-containing (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, monobutyl hydroxy fumarate, and monobutyl hydroxy itaconate.

In addition, as bifunctional (meth)acrylates, examples thereof include alkane diol di(meth)acrylates such as 1,4-butanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, and tricyclodecanedimethylol di(meth)acrylate; bisphenol-modified di(meth)acrylates such as bisphenol A ethylene oxide-modified di(meth)acrylate and bisphenol F ethylene oxide-modified di(meth)acrylate; polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, urethane di(meth)acrylate, and epoxy di(meth)acrylate.

In addition, as polyfunctional (meth)acrylates having three or more functions, examples thereof include dipentaerythritol hexa(meth)acrylate, pentaerythritol tetra(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, pentaerythritol tri(meth)acrylate, trimethylolpropane tri(meth)acrylate; ethylene oxide-modified (meth)acrylates such as ethylene oxide-modified dipentaerythritol hexa(meth)acrylate and ethylene oxide-modified pentaerythritol tetra(meth)acrylate; isocyanuric acid-modified tri(meth)acrylates such as isocyanuric acid ethylene oxide-modified tri(meth)acrylate and ε-caprolactone-modified tris(acryloxyethyl)isocyanurate.

In addition, as (meth)acrylates, (meth)acrylates having an epoxy group can be mentioned, and examples thereof include glycidyl (meth)acrylate, 3,4-epoxycyclohexyl (meth)acrylate, 3,4-epoxycyclohexylmethyl (meth)acrylate, and the like. Among these, glycidyl (meth)acrylate is preferable, and glycidyl methacrylate is particularly preferable, considering particularly good reactivity and ease of use of the material.

In addition, as (meth)acrylates, carboxyl group-containing (meth)acrylates such as acrylic acid, methacrylic acid, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, itaconic acid, citraconic acid, maleic acid, fumaric acid, crotonic acid, and isocrotonic acid can be suitably mentioned.

(urethane resin)

Urethane resin is a polymer compound having a urethane structure in the molecule. Urethane resin is usually manufactured by the reaction of polyol and polyisocyanate. Examples of polyols include polycarbonate polyols, polyester polyols, polyether polyols, polyolefin polyols, and acrylic polyols. These compounds may be used alone or in combination.

Polycarbonate polyols are obtained from polyhydric alcohols and carbonate compounds by a dealcoholization reaction. Examples of the polyhydric alcohols include ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, 3,3-dimethylolheptane, etc. Examples of carbonate compounds include dimethyl carbonate, diethyl carbonate, diphenyl carbonate, and ethylene carbonate, and examples of polycarbonate polyols obtained from reactions thereof include poly(1,6-hexylene) carbonate and poly(3-methyl-1,5-pentylene) carbonate.

Polyester polyols include polycarboxylic acids (malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, sebacic acid, fumaric acid, maleic acid, terephthalic acid, isophthalic acid, etc.) or their acid anhydrides and polyhydric alcohols (ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 2-methyl-1,3-propanediol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 2-methyl-2,4-pentanediol, 2-methyl-2-propyl-1,3-propanediol, 1,8-octanediol, Examples thereof include those obtained from the reaction of 2,2,4-trimethyl-1,3-pentanediol, 2-ethyl-1,3-hexanediol, 2,5-dimethyl-2,5-hexanediol, 1,9-nonanediol, 2-methyl-1,8-octanediol, 2-butyl-2-ethyl-1,3-propanediol, 2-butyl-2-hexyl-1,3-propanediol, cyclohexanediol, bishydroxymethylcyclohexane, dimethanolbenzene, bishydroxyethoxybenzene, alkyldialkanolamines, lactone diols, etc.

Examples of polyether polyols include polyethylene glycol, polypropylene glycol, polyethylene propylene glycol, polytetramethylene ether glycol, and polyhexamethylene ether glycol.

Isocyanate compounds used for obtaining urethane resins include aromatic diisocyanates such as tolylene diisocyanate, xylylene diisocyanate, methylene diphenyl diisocyanate, phenylene diisocyanate, naphthalene diisocyanate, and tolidine diisocyanate; aliphatic diisocyanates having an aromatic ring such as α,α,α',α'-tetramethylxylylene diisocyanate; aliphatic diisocyanates such as methylene diisocyanate, propylene diisocyanate, lysine diisocyanate, trimethylhexamethylene diisocyanate, and hexamethylene diisocyanate; Examples include alicyclic diisocyanates such as cyclohexane diisocyanate, methylcyclohexane diisocyanate, isophorone diisocyanate, dicyclohexyl methane diisocyanate, and isopropylidenedicyclohexyl diisocyanate. These may be used alone or in combination of two or more.

When synthesizing a urethane resin, a chain extender may be used. There are no particular restrictions on the chain extender as long as it has two or more active groups that react with isocyanate groups. In general, chain extenders having two hydroxyl groups or amino groups can be mainly used.

Examples of chain extenders having two hydroxyl groups include aliphatic glycols such as ethylene glycol, propylene glycol, and butanediol; aromatic glycols such as xylylene glycol and bishydroxyethoxybenzene; and glycols such as ester glycols such as neopentyl glycol hydroxypivalate. In addition, examples of chain extenders having two amino groups include aromatic diamines such as tolylene diamine, xylylene diamine, and diphenyl methane diamine; aliphatic diamines such as ethylene diamine, propylenediamine, hexanediamine, 2,2-dimethyl-1,3-propanediamine, 2-methyl-1,5-pentane diamine, trimethylhexanediamine, 2-butyl-2-ethyl-1,5-pentane diamine, 1,8-octanediamine, 1,9-nonane diamine, and 1,10-decane diamine. Examples include alicyclic diamines such as 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane, dicyclohexylmethanediamine, isoproviritincyclohexyl-4,4'-diamine, 1,4-diaminocyclohexane, and 1,3-bisaminomethylcyclohexane.

(Compound having a condensed polycyclic aromatic structure)

In the laminated film of the present invention, it is preferable that the binder (A-a) included in the curable resin composition (A') forming the cured resin layer (A) includes a compound having a condensed polycyclic aromatic structure. By including the compound, it becomes easy to adjust the refractive index of the cured resin layer (A).

As condensed polycyclic aromatics, naphthalene, anthracene, phenanthrene, naphthacene, benzo[a]anthracene, benzo[a]phenanthrene, pyrene, benzo[c]phenanthrene, perylene, etc. can be mentioned as exemplified in the formula below.

A compound having a condensed polycyclic aromatic structure means a compound including a condensed polycyclic aromatic as exemplified in the formula below, or a compound including a structure derived from a condensed polycyclic aromatic as exemplified in the formula below.

[Chemical Formula 1]

Considering the applicability to a base film such as a polyester film, as a compound having a condensed polycyclic aromatic structure, for example, a polymer compound such as a polycyclic polyester resin is preferable. In particular, the compound having a condensed polycyclic aromatic structure is preferably a polycyclic polyester resin, and this is preferable because more condensed polycyclic aromatics can be introduced into the polycyclic polyester resin. In addition, in this specification, a polycyclic polyester resin is a polyester resin having a condensed polycyclic aromatic structure.

As a method for incorporating a condensed polycyclic aromatic structure into a polyester resin, for example, there is a method of introducing two or more hydroxyl groups as substituents into a condensed polycyclic aromatic to form a diol component or a polyvalent hydroxyl group component, or of introducing two or more carboxylic acid groups to form a dicarboxylic acid component or a polyvalent carboxylic acid component, and using them for polymerization of a polyester resin.

In the manufacturing process of the laminated film, from the viewpoint of being difficult to color, it is preferable that the compound having a condensed polycyclic aromatic structure included in the cured resin layer (A) is a compound having a naphthalene skeleton. Furthermore, from the viewpoint of having good adhesion to the cured resin layer (B) formed on the cured resin layer (A) and good transparency, a resin incorporating a naphthalene skeleton as a polyester component is suitably used. Representative examples of the naphthalene skeleton include 1,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, and 2,7-naphthalenedicarboxylic acid.

In addition, in addition to a hydroxyl group or a carboxylic acid group, by introducing a substituent containing a sulfur element, an aromatic substituent such as a phenyl group, a halogen element group, etc., into the condensed polycyclic aromatic, an improvement in the refractive index can be expected, and from the viewpoint of coatability or adhesion, a substituent such as an alkyl group, an ester group, an amide group, a sulfonic acid group, a carboxylic acid group, or a hydroxyl group can be introduced.

Among compounds having condensed polycyclic aromatic groups, the proportion of condensed polycyclic aromatic rings is preferably 5 to 80 mass%, more preferably 10 to 60 mass%. The proportion of condensed polycyclic aromatic rings means, for example, the content of naphthalene rings in a polyester resin having a naphthalene ring as the condensed polycyclic aromatic group.

In addition, the content of the compound having a condensed polycyclic aromatic group in the curable resin composition (A') is preferably 80 mass% or less, more preferably 5 to 70 mass%, and even more preferably 10 to 50 mass%, with respect to the total nonvolatile component amount (total solid content) in the curable resin composition A.

By setting the content of the compound having a condensed polycyclic aromatic group in the curable resin composition (A') within the above range, it becomes easy to adjust the refractive index of the cured resin layer (A) itself, and it becomes easy to reduce the occurrence of an interference pattern after the formation of the cured resin layer (B). In addition, the content of the compound having a condensed polycyclic aromatic group can be obtained, for example, by dissolving and extracting the cured resin layer (A) in a suitable solvent or warm water, fractionating it by chromatography, analyzing the structure by NMR or IR, or further analyzing it by pyrolysis GC-MS (gas chromatography mass spectrometry) or optical analysis.

(A-b) Crosslinker

Examples of the crosslinking agent include oxazoline compounds, melamine compounds, epoxy compounds, carbodiimide compounds, and isocyanate compounds. Among these crosslinking agents, from the viewpoint of improving adhesion to the base film, it is preferable to use at least one selected from the group consisting of oxazoline compounds, epoxy compounds, isocyanate compounds, melamine compounds, and carbodiimide compounds, more preferably at least one selected from an oxazoline compound, an epoxy compound, and an isocyanate compound, still more preferably at least one selected from an oxazoline compound and an epoxy compound, and particularly preferably a combination of an oxazoline compound and an epoxy compound.

The content of the crosslinking agent is preferably 2 to 80 mass%, more preferably 4 to 60 mass%, and even more preferably 10 to 40 mass%, based on the total nonvolatile component content (total solid content) in the curable resin composition (A'). By setting the content of the crosslinking agent within the above range, the adhesion of the cured resin layer (A), which is a cured product, to the cured resin layer (B) can be more effectively increased.

(Oxazoline compounds)

An oxazoline compound is a compound having an oxazoline group in the molecule, and in particular, a polymer containing an oxazoline group is preferable. The polymer containing an oxazoline group can be produced by polymerization of an addition polymerizable oxazoline group-containing monomer alone or with another monomer. Examples of the addition polymerizable oxazoline group-containing monomer include 2-vinyl-2-oxazoline, 2-vinyl-4-methyl-2-oxazoline, 2-vinyl-5-methyl-2-oxazoline, 2-isopropenyl-2-oxazoline, 2-isopropenyl-4-methyl-2-oxazoline, 2-isopropenyl-5-ethyl-2-oxazoline, and the like, and one type or a mixture of two or more types thereof can be used. Of these, 2-isopropenyl-2-oxazoline is preferable because it is easy to obtain industrially. There is no limitation on other monomers as long as they are monomers copolymerizable with the addition polymerizable oxazoline group-containing monomer, and examples thereof include (meth)acrylic acid esters such as alkyl (meth)acrylates (alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl, 2-ethylhexyl, and cyclohexyl); unsaturated carboxylic acids such as acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid, styrenesulfonic acid, and their salts (sodium salts, potassium salts, ammonium salts, tertiary amine salts, etc.); unsaturated nitriles such as acrylonitrile and methacrylonitrile; Unsaturated amides such as (meth)acrylamide, N-alkyl (meth)acrylamide, N,N-dialkyl (meth)acrylamide, (alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl, 2-ethylhexyl, and cyclohexyl); vinyl esters such as vinyl acetate and vinyl propionate; vinyl ethers such as methyl vinyl ether and ethyl vinyl ether; α-olefins such as ethylene and propylene; halogen-containing α,β-unsaturated monomers such as vinyl chloride, vinylidene chloride, and vinyl fluoride; α,β-unsaturated aromatic monomers such as styrene and α-methylstyrene; and one or more types of these monomers can be used.

(melamine compound)

Melamine compounds are compounds having a melamine skeleton among compounds. For example, alkylated melamine derivatives, compounds partially or completely etherified by reacting alkylated melamine derivatives with alcohol, and mixtures thereof can be used. As the alcohol used for etherification, methyl alcohol, ethyl alcohol, isopropyl alcohol, n-butanol, isobutanol, etc. are suitably used. In addition, the melamine compound may be a monomer, a polymer of dimers or more, or a mixture thereof can be used. In addition, a compound obtained by co-condensing urea, etc. with a part of melamine can also be used, and it is also possible to use a catalyst to increase the reactivity of the melamine compound.

(epoxy compound)

Epoxy compounds are compounds having an epoxy group in the molecule, and examples thereof include condensates of epichlorohydrin with hydroxyl groups or amino groups such as ethylene glycol, polyethylene glycol, glycerin, polyglycerin, and bisphenol A, as well as polyepoxy compounds, diepoxy compounds, monoepoxy compounds, and glycidylamine compounds. Examples of polyepoxy compounds include sorbitol polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, diglycerol polyglycidyl ether, triglycidyl tris(2-hydroxyethyl) isocyanate, glycerol polyglycidyl ether, and trimethylolpropane polyglycidyl ether. Examples of diepoxy compounds include neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, resorcin diglycidyl ether, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, polytetramethylene glycol diglycidyl ether, etc. Examples of monoepoxy compounds include allyl glycidyl ether, 2-ethylhexyl glycidyl ether, phenyl glycidyl ether, and examples of glycidylamine compounds include N,N,N',N'-tetraglycidyl-m-xylylene diamine, 1,3-bis(N,N-diglycidylamino)cyclohexane, etc.

(Carbodiimide compounds)

A carbodiimide-based compound is a compound having a carbodiimide structure, and is a compound having one or more carbodiimide structures in the molecule. However, for better adhesion, etc., a polycarbodiimide-based compound having two or more carbodiimide structures in the molecule is more preferable.

Carbodiimide compounds can be synthesized by conventionally known techniques, and generally, a condensation reaction of a diisocyanate compound is used. The diisocyanate compound is not particularly limited, and both aromatic and aliphatic compounds can be used, and specific examples thereof include tolylene diisocyanate, xylene diisocyanate, diphenylmethane diisocyanate, phenylene diisocyanate, naphthalene diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, cyclohexane diisocyanate, methylcyclohexane diisocyanate, isophorone diisocyanate, dicyclohexyl diisocyanate, and dicyclohexylmethane diisocyanate.

Additionally, in a range that does not lose the effects of the present invention, in order to improve the water solubility or water dispersibility of the polycarbodiimide compound, a surfactant may be added, or a hydrophilic monomer such as a polyalkylene oxide, a quaternary ammonium salt of a dialkylaminoalcohol, or a hydroxyalkyl sulfonate may be added and used.

(isocyanate compounds)

Isocyanate compounds are compounds having an isocyanate derivative structure, represented by isocyanate or blocked isocyanate. Examples of the isocyanate include aromatic isocyanates such as tolylene diisocyanate, xylylene diisocyanate, methylene diphenyl diisocyanate, phenylene diisocyanate, and naphthalene diisocyanate; aliphatic isocyanates having an aromatic ring such as α,α,α',α'-tetramethylxylylene diisocyanate; aliphatic isocyanates such as methylene diisocyanate, propylene diisocyanate, lysine diisocyanate, trimethylhexamethylene diisocyanate, and hexamethylene diisocyanate; Examples thereof include alicyclic isocyanates such as cyclohexane diisocyanate, methylcyclohexane diisocyanate, isophorone diisocyanate, methylenebis(4-cyclohexyl isocyanate), and isopropylidenedicyclohexyl diisocyanate. In addition, polymers and derivatives of these isocyanates such as biuret compounds, isocyanurate compounds, uretdione compounds, and carbodiimide-modified products can also be mentioned. These may be used alone or in combination of two or more types. Among the above isocyanates, aliphatic isocyanates or alicyclic isocyanates are more preferable than aromatic isocyanates in order to avoid yellowing due to ultraviolet rays.

When used in the state of a blocked isocyanate, examples of the blocking agent include phenol compounds such as bisulfite, phenol, cresol, and ethylphenol; alcohol compounds such as propylene glycol monomethyl ether, ethylene glycol, benzyl alcohol, methanol, and ethanol; active methylene compounds such as dimethyl malonate, diethyl malonate, methyl acetoacetate, ethyl acetoacetate, and acetylacetone; mercaptan compounds such as butyl mercaptan and dodecyl mercaptan; lactam compounds such as ε-caprolactam and δ-valerolactam; amine compounds such as diphenylaniline, aniline, and ethyleneimine; Examples of the compounds include oxime compounds such as acetanilide, acid amide compounds of acetic acid amide, formaldehyde, acetaldoxime, acetone oxime, methyl ethyl ketone oxime, and cyclohexanone oxime, and these may be used alone or in combination of two or more.

(A-c) particle

From the viewpoint of imparting a high refractive index to the curable resin layer (A), the curable resin composition (A') may contain particles. Examples of the particles include inorganic particles such as silica, calcium carbonate, magnesium carbonate, barium carbonate, calcium sulfate, calcium phosphate, magnesium phosphate, kaolin, aluminum oxide, and titanium oxide; and organic particles such as acrylic resin, styrene resin, urea resin, phenol resin, epoxy resin, and benzoguanamine resin.

Among these, it is preferable that the cured resin layer (A) contains a metal oxide as (A-c) particles. By containing a metal oxide in the cured resin layer (A), its refractive index can be increased, and the occurrence of interference patterns can be suppressed more effectively.

(metal oxide)

As the metal oxide, it is preferable to use a metal oxide having a high refractive index, and it is preferable to use a metal oxide having a refractive index of 1.7 or higher. Specific examples of the metal oxide include silicon dioxide, zirconium oxide, aluminum oxide (alumina), titanium oxide, tin oxide, yttrium oxide, antimony oxide, indium oxide, zinc oxide, antimony tin oxide, indium tin oxide, etc., and these may be used alone or in combination of two or more. Among these, at least one selected from zirconium oxide and titanium oxide is more suitably used, and in particular, zirconium oxide is more suitably used from the viewpoint of weather resistance.

Metal oxides are preferably used in the form of particles because there is a concern that the adhesion may be reduced depending on the form of use. In addition, from the viewpoint of transparency, the average particle diameter is preferably 100 nm or less, more preferably 50 nm or less, and even more preferably 25 nm or less. In addition, there is no particular limitation on the lower limit of the average particle diameter, but from the viewpoint of dispersibility, it is preferably 5 nm or more, and more preferably 10 nm or more.

In addition, the cured resin layer (A) may contain particles other than the metal oxides described above for the purpose of improving the adhesiveness and sliding properties. Specific examples of particles other than the metal oxides include silica, kaolin, calcium carbonate, organic particles, etc., and among these, silica is suitably used from the viewpoint of sliding properties. The average particle diameter of the particles other than the metal oxides is preferably 1.0 µm or less, more preferably 0.5 µm or less, and even more preferably 0.2 µm or less from the viewpoint of the transparency of the film. In addition, there is no particular limitation on the lower limit of the average particle diameter of the particles other than the metal oxides, but it is preferably 20 nm or more, and more preferably 40 nm or more from the viewpoint of dispersibility.

In addition, as particles, it is preferable to use two types of particles with different particle sizes from the viewpoint of imparting activity, and furthermore, it is preferable to use a combination of metal oxides and particles other than metal oxides with different particle sizes.

The above average particle size is a value measured by, for example, laser diffraction/scattering, dynamic light scattering (DLS), centrifugal sedimentation, particle trajectory analysis (PTA), scanning electron microscopy (SEM), etc.; however, if it is a commercial product, the catalog value can be adopted.

The average particle size can be calculated by the sedimentation method based on the Stokes resistance value. As a measuring device, for example, a centrifugal sedimentation particle size distribution measuring device SA-CP3 manufactured by Shimadzu Corporation can be used.

The content of the (A-c) particles with respect to the total nonvolatile component amount (total solid content) in the curable resin composition (A') forming the cured resin layer (A) is preferably 3% by mass or more, more preferably 5% by mass or more, and even more preferably 7% by mass or more. Furthermore, the content of the (A-c) particles with respect to the total nonvolatile component amount (total solid content) in the curable resin composition (A') is preferably 70% by mass or less, more preferably 50% by mass or less, even more preferably 40% by mass or less, and especially preferably 30% by mass or less. By setting the content of the (A-c) particles within the above range, it is possible to achieve both transparency and low-interference effect of the laminated film.

In the present embodiment, a more excellent low-interference effect is obtained by combining particles (A-c) of a metal compound or the like and the polycyclic polyester resin (polyester resin having a condensed polycyclic aromatic structure) described above in the cured resin layer (A).

(Curable resin composition (B'))

Curable resin composition B contains (X) urethane (meth)acrylate and (Y) a compound having a cyclic siloxane skeleton.

The mass average molecular weight of the (X) urethane (meth)acrylate included in the curable resin composition (B') is preferably 100 or more, more preferably 200 or more, and more preferably 400 or more. On the other hand, with regard to the upper limit, it is preferably 500,000 or less, more preferably 400,000 or less, and more preferably 250,000 or less.

In addition, in the present invention, when the expression "(meth)acrylic" is used, it means one or both of "acrylic" and "methacrylic." The same applies to "(meth)acrylate" and "(meth)acryloyl."

((X) Urethane (meth)acrylate)

Urethane (meth)acrylate is produced by reacting an isocyanate compound and a hydroxyl group-containing (meth)acrylate compound, or by reacting an isocyanate compound, a polyol compound, and a hydroxyl group-containing (meth)acrylate compound. Urethane (meth)acrylate can be used alone or in combination of two or more.

As the isocyanate compound, examples thereof include polyisocyanate compounds such as aromatic polyisocyanates, aliphatic polyisocyanates, and alicyclic polyisocyanates. Among these, it is preferable that the isocyanate compound is a diisocyanate compound. In addition, as the isocyanate compound, an isocyanate compound having an isocyanurate skeleton obtained by isocyanurating a diisocyanate compound can also be used.

Examples of the above aromatic polyisocyanates include tolylene diisocyanate, diphenylmethane diisocyanate, polyphenylmethane polyisocyanate, modified diphenylmethane diisocyanate, xylylene diisocyanate, tetramethylxylylene diisocyanate, phenylene diisocyanate, naphthalene diisocyanate, and the like.

Examples of the above aliphatic polyisocyanates include hexamethylene diisocyanate, pentamethylene diisocyanate, trimethylhexamethylene diisocyanate, lysine diisocyanate, and lysine triisocyanate.

As the above alicyclic polyisocyanates, examples thereof include hydrogenated diphenylmethane diisocyanate, hydrogenated xylylene diisocyanate, isophorone diisocyanate, norbornene diisocyanate, 1,3-bis(isocyanatomethyl)cyclohexane, 1,4-bis(isocyanatomethyl)cyclohexane, and the like.

Among these, it is preferable to use aliphatic diisocyanates and alicyclic diisocyanates from the viewpoint of excellent yellowing resistance. In addition, it is also preferable to use an isocyanate compound having an isocyanurate skeleton, and from the same viewpoint, it is also preferable to use an isocyanate compound having an isocyanurate skeleton obtained by isocyanurating an aliphatic diisocyanate or an alicyclic diisocyanate, and among these, it is more preferable to use an isocyanate compound having an isocyanurate skeleton.

Isocyanate compounds may be used alone or in combination of two or more.

The above hydroxyl group-containing (meth)acrylate is a compound having a hydroxyl group and a (meth)acryloyl group, and examples thereof include hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, and 6-hydroxyhexyl (meth)acrylate; Monofunctional hydroxyl group-containing (meth)acrylates having one ethylenically unsaturated group, such as 2-hydroxyethyl acryloyl phosphate, 2-(meth)acryloyloxyethyl-2-hydroxypropyl phthalate, caprolactone-modified 2-hydroxyethyl (meth)acrylate, dipropylene glycol (meth)acrylate, fatty acid-modified glycidyl (meth)acrylate, polyethylene glycol mono (meth)acrylate, polypropylene glycol mono (meth)acrylate, and 2-hydroxy-3-(meth)acryloyloxypropyl (meth)acrylate; Examples thereof include bifunctional hydroxyl-containing (meth)acrylates having two ethylenically unsaturated groups, such as glycerin di(meth)acrylate, 2-hydroxy-3-acryloyl-oxypropyl methacrylate; trifunctional or higher hydroxyl-containing (meth)acrylates having three or more ethylenically unsaturated groups, such as pentaerythritol tri(meth)acrylate, caprolactone-modified pentaerythritol tri(meth)acrylate, ethylene oxide-modified pentaerythritol tri(meth)acrylate, dipentaerythritol penta(meth)acrylate, caprolactone-modified dipentaerythritol penta(meth)acrylate, and ethylene oxide-modified dipentaerythritol penta(meth)acrylate; These can be used alone or in combination of two or more.

Among these, it is preferable to use a (meth)acrylate compound containing three or more ethylenically unsaturated groups, and furthermore, it is particularly preferable to use pentaerythritol tri(meth)acrylate or dipentaerythritol penta(meth)acrylate, in view of excellent reactivity and versatility and excellent balance of abrasion resistance and bendability of the cured resin layer.

The above polyol compound may be a compound having two or more hydroxyl groups (except for the above hydroxyl group-containing (meth)acrylate).

Examples of the polyol compounds include aliphatic polyols, alicyclic polyols, polyether polyols, polyester polyols, polycarbonate polyols, polyolefin polyols, polybutadiene polyols, polyisoprene polyols, (meth)acrylic polyols, and polysiloxane polyols.

Examples of the aliphatic polyols include aliphatic alcohols containing two hydroxyl groups, such as ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, trimethylene glycol, dimethylolpropane, neopentyl glycol, 2,2-diethyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-propanediol, 1,4-tetramethylenediol, 1,3-tetramethylenediol, 2-methyl-1,3-trimethylenediol, 1,5-pentamethylenediol, 1,6-hexamethylenediol, 3-methyl-1,5-pentamethylenediol, 2,4-diethyl-1,5-pentamethylenediol, pentaerythritol diacrylate, 1,9-nonanediol, and 2-methyl-1,8-octanediol; sugar alcohols such as xylitol and sorbitol; Examples include aliphatic alcohols containing three or more hydroxyl groups, such as glycerin, trimethylolpropane, and trimethylolethane.

Examples of the above alicyclic polyols include cyclohexanediols such as 1,4-cyclohexanediol and cyclohexyldimethanol; hydrogenated bisphenols such as hydrogenated bisphenol A; and tricyclodecane dimethanol.

Examples of polyether polyols include alkylene structure-containing polyether polyols such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polybutylene glycol, polypentamethylene glycol, and polyhexamethylene glycol, and random or block copolymers of these polyalkylene glycols.

Examples of polyester polyols include condensation polymers of polyhydric alcohols and polyhydric carboxylic acids, ring-opening polymers of cyclic esters (lactones), and reaction products of three types of components: polyhydric alcohols, polyhydric carboxylic acids, and cyclic esters.

Examples of the above polyhydric alcohols include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, trimethylene glycol, 1,4-tetramethylenediol, 1,3-tetramethylenediol, 2-methyl-1,3-trimethylenediol, 1,5-pentamethylenediol, neopentyl glycol, 1,6-hexamethylenediol, 3-methyl-1,5-pentamethylenediol, 2,4-diethyl-1,5-pentamethylenediol, glycerin, trimethylolpropane, trimethylolethane, cyclohexanediols (such as 1,4-cyclohexanediol), bisphenols (such as bisphenol A), and sugar alcohols (such as xylitol and sorbitol).

Examples of the above polycarboxylic acids include aliphatic dicarboxylic acids such as malonic acid, maleic acid, fumaric acid, succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, and dodecanedioic acid; alicyclic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid; and aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, orthophthalic acid, 2,6-naphthalenedicarboxylic acid, paraphenylenedicarboxylic acid, and trimellitic acid.

Examples of the above-mentioned cyclic esters include propiolactone, β-methyl-δ-valerolactone, and ε-caprolactone.

Examples of the above polycarbonate-based polyols include a reaction product of a polyhydric alcohol and phosgene, a ring-opening polymerization product of a cyclic carbonate ester (such as an alkylene carbonate), etc.

As the polyhydric alcohol used in the polycarbonate-based polyol, examples thereof include the polyhydric alcohols exemplified in the description of the polyester-based polyol, and as the alkylene carbonate, examples thereof include ethylene carbonate, trimethylene carbonate, tetramethylene carbonate, and hexamethylene carbonate.

In addition, the polycarbonate polyol may be a compound having a carbonate bond in the molecule and a hydroxyl group at the terminal, and may also have an ester bond together with the carbonate bond.

As the above polyolefin-based polyol, examples thereof include those having a homopolymer or copolymer of ethylene, propylene, butene, etc. as a saturated hydrocarbon backbone and having a hydroxyl group at the molecular terminal.

As the above polybutadiene-based polyol, one may exemplify one having a copolymer of butadiene as a hydrocarbon skeleton and having a hydroxyl group at the molecular terminal.

The polybutadiene-based polyol may be a hydrogenated polybutadiene polyol in which all or part of the ethylenically unsaturated groups included in its structure are hydrogenated.

As the above polyisoprene-based polyol, one may exemplify one having an isoprene copolymer as a hydrocarbon skeleton and a hydroxyl group at the molecular terminal.

The polyisoprene-based polyol may be a hydrogenated polyisoprene polyol in which all or part of the ethylenically unsaturated groups included in its structure are hydrogenated.

As the above (meth)acrylic polyol, examples thereof include those having at least two hydroxyl groups in the molecule of a polymer or copolymer of (meth)acrylic acid ester, and examples of such (meth)acrylic acid esters include (meth)acrylic acid alkyl esters such as methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, hexyl (meth)acrylate, octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, decyl (meth)acrylate, dodecyl (meth)acrylate, and octadecyl (meth)acrylate. In addition, it may be a copolymer of (meth)acrylic acid ester and (meth)acrylic acid hydroxyalkyl such as (meth)acrylic acid hydroxyethyl, (meth)acrylic acid hydroxypropyl, and (meth)acrylic acid hydroxybutyl.

Examples of the above polysiloxane-based polyols include dimethylpolysiloxane polyol and methylphenylpolysiloxane polyol.

The above polyol compounds can be used singly or in combination of two or more.

In the addition reaction of the above isocyanate compound and the hydroxyl group-containing (meth)acrylate compound, or the addition reaction of the isocyanate compound, the hydroxyl group-containing (meth)acrylate compound, and the polyol, the reaction is terminated when the content of residual isocyanate groups in the reaction system becomes 0.5 mass% or less, thereby obtaining urethane (meth)acrylate.

When the urethane (meth)acrylate includes one formed by reacting an isocyanate-based compound, a polyol-based compound, and a hydroxyl group-containing (meth)acrylate-based compound, it is preferable to obtain the urethane (meth)acrylate by reacting a reaction product having an isocyanate group obtained by reacting the isocyanate-based compound and the polyol-based compound, or a mixture of the reaction product and the isocyanate-based compound, with a hydroxyl group-containing (meth)acrylate-based compound. The urethane (meth)acrylate obtained by such a reaction may be a mixture of one formed by reacting an isocyanate-based compound and a hydroxyl group-containing (meth)acrylate-based compound, and one formed by reacting an isocyanate-based compound, a polyol-based compound, and a hydroxyl group-containing (meth)acrylate-based compound.

In the reaction of an isocyanate compound and a hydroxyl group-containing (meth)acrylate compound, it is also preferable to use a catalyst for the purpose of promoting the reaction, and examples of such catalysts include organometallic compounds such as dibutyltin dilaurate, dibutyltin diacetate, trimethyltin hydroxide, tetra-n-butyltin, zinc bisacetylacetonate, zirconium tris(acetylacetonate)ethylacetoacetate, and zirconium tetraacetylacetonate; metal salts such as tin octenoate, zinc hexanoate, zinc octenoate, zinc stearate, zirconium 2-ethylhexanoate, cobalt naphthenate, stannous chloride, stannous chloride, and potassium acetate; Amine catalysts such as triethylamine, triethylenediamine, benzyldiethylamine, 1,4-diazabicyclo[2,2,2]octane, 1,8-diazabicyclo[5,4,0]undecene, N,N,N',N'-tetramethyl-1,3-butanediamine, N-methylmorpholine, and N-ethylmorpholine; bismuth nitrate, bismuth bromide, bismuth iodide, bismuth sulfide, and the like; organic bismuth compounds such as dibutylbismuth dilaurate and dioctylbismuth dilaurate; Examples of bismuth catalysts include organic acid bismuth salts such as 2-ethylhexanoic acid bismuth salt, naphthenic acid bismuth salt, isodecanoic acid bismuth salt, neodecanoic acid bismuth salt, lauric acid bismuth salt, maleic acid bismuth salt, stearic acid bismuth salt, oleic acid bismuth salt, linoleic acid bismuth salt, acetic acid bismuth salt, bismuthtribisneodecanoate, disalicylic acid bismuth salt, and digalic acid bismuth salt. Among these, dibutyltin dilaurate and 1,8-diazabicyclo[5,4,0]undecene are preferable as catalysts. These may be used alone or in combination of two or more.

In addition, in the reaction of an isocyanate compound and a hydroxyl group-containing (meth)acrylate compound, an organic solvent that does not have a functional group that reacts with an isocyanate group, for example, an organic solvent such as esters such as ethyl acetate and butyl acetate; a ketone such as methyl ethyl ketone and methyl isobutyl ketone; an aromatic solvent such as toluene and xylene, can be used. In addition, a polymerization inhibitor, etc. may be appropriately used.

In addition, urethane (meth)acrylate is a reaction product of a hydroxyl group-containing (meth)acrylate compound and an isocyanate compound, or a hydroxyl group-containing (meth)acrylate compound, an isocyanate compound, and a polyol compound, but may be produced by reacting a mixture of a hydroxyl group-containing (meth)acrylate and a (meth)acrylate not having a hydroxyl group with an isocyanate compound. Alternatively, it may be produced by reacting a mixture of a hydroxyl group-containing (meth)acrylate and a (meth)acrylate not having a hydroxyl group, an isocyanate compound, and a polyol compound. At this time, the (meth)acrylate not having a hydroxyl group remains as an unreacted product, but may be contained as is in the curable resin composition.

In addition, in the reaction of the isocyanate compound and the hydroxyl group-containing (meth)acrylate compound described above, as described above, part or all of the isocyanate compound may be a reaction product of the isocyanate compound and the polyol compound.

(X) The (meth)acryloyl group equivalent of the urethane (meth)acrylate is preferably 120 g/eq or more and 250 g/eq or less, more preferably 135 g/eq or more and 220 g/eq or less, and even more preferably 150 g/eq or more and 200 g/eq or less. (X) When the (meth)acryloyl group equivalent of the urethane (meth)acrylate is within the above range, it becomes easy to adjust the crosslinking point, and formation of a cured resin layer having an appropriate crosslinking density becomes possible. Thereby, high hardness can be imparted to the cured resin layer.

The content of (X) urethane (meth)acrylate in the curable resin composition (B') is preferably 50 mass% or more, and more preferably 60 mass% or more, based on the total nonvolatile component content (total solid content) in the curable resin composition (B').

When forming a curable resin (B), it is preferable to prepare a base polymer by using the above (X) urethane (meth)acrylate alone or by mixing two or more types and polymerizing them. It is preferable that the base polymer is dissolved or dispersed in a solvent, etc. described below, and then applied onto a curable resin layer (A), and cured to form a curable resin layer (B).

(menstruum)

The curable resin composition (B') may be made into a coating liquid by diluting it with a solvent. It is preferable that the curable resin composition (B') is applied as a liquid coating liquid on the curable resin layer (A), dried, and further cured to form the curable resin layer (B). Each component constituting the curable resin composition (B') may be dissolved in a solvent, or may be dispersed in the solvent.

As the solvent, an organic solvent is preferable. As the organic solvent, for example, aromatic solvents such as toluene and xylene; ketone solvents such as methyl ethyl ketone (MEK), acetone, methyl isobutyl ketone (MIBK), cyclohexanone and diisobutyl ketone; ether solvents such as diethyl ether, isopropyl ether, tetrahydrofuran, dioxane, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, propylene glycol monomethyl ether (PGM), anisole and phenetole; ester solvents such as ethyl acetate, butyl acetate, isopropyl acetate and ethylene glycol diacetate; amide solvents such as dimethylformamide, diethylformamide, dimethylacetamide and N-methylpyrrolidone; cellosolve solvents such as methyl cellosolve, ethyl cellosolve and butyl cellosolve. Examples thereof include alcohol solvents such as methanol, ethanol, propanol, isopropanol, and butanol; halogen solvents such as dichloromethane and chloroform; and the like. One of these organic solvents may be used alone, or two or more may be used in combination. Among these organic solvents, at least one selected from the group consisting of ester solvents, ether solvents, alcohol solvents, and ketone solvents is preferably used.

There is no particular limitation on the amount of the organic solvent to be used, and it is appropriately determined in consideration of the coatability of the curable resin composition to be prepared, the viscosity and surface tension of the liquid, the compatibility of the solid content, etc. The curable resin composition is prepared as a coating liquid having a solid content concentration of preferably 15 to 80 mass%, more preferably 20 to 70 mass%, using the solvent described above. In addition, the "solid content" in the curable resin composition means a component excluding the solvent, which is a volatile component, and includes not only solid components but also semi-solid or viscous liquid substances.

((Y) Compound having a cyclic siloxane skeleton)

The curable resin composition (B') contains a compound having a cyclic siloxane skeleton (Y). The compound having a cyclic siloxane skeleton is preferably a compound represented by the following general formula.

[Chemical formula 2]

In the above formula, R ¹ and R ² each independently represent a hydrogen atom or a substituent, and n represents an integer from 1 to 50. As the substituent, examples thereof include a hydrocarbon group, an organic group containing a fluorine atom, an organic group containing a (meth)acrylic group, and the like. In terms of abrasion resistance, n is preferably an integer from 1 to 30, and more preferably an integer from 2 to 20.

As the hydrocarbon group, an aliphatic hydrocarbon group (for example, an alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group), an aromatic hydrocarbon group (for example, a phenyl group, a naphthyl group, anthryl group, a phenanthryl group, a biphenyl group), etc. can be mentioned. The hydrocarbon group is preferably a linear or branched alkyl group or phenyl group having 1 to 18 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an isopropyl group, etc. In addition, the hydrocarbon group may further have a substituent, and may have a halogen atom (for example, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom) as the substituent.

As the organic group containing a fluorine atom, for example, a group represented by C _x F _2x+1 (CH ₂ ) _p - (wherein x is an integer from 1 to 8 and p is an integer from 2 to 10), a group represented by C _x F _2x+1 C(CF ₃ ) ₂ (CH ₂ ) _p - (wherein x is an integer from 1 to 8 and p is an integer from 2 to 10), or a group having a perfluoroether structure (for example, a perfluoropolyether-substituted alkyl group) is preferable. Specific examples of organic compounds containing a fluorine atom include, for example, CF ₃ C ₂ H ₄ -, C ₄ F ₉ C ₂ H ₄ -, C ₄ F ₉ C ₃ H ₆ -, C ₈ F ₁₇ C ₂ H ₄ -, C ₈ F ₁₇ C ₃ H ₆ -, C ₃ F ₇ C(CF ₃ ) ₂ C ₃ H ₆ -, C ₃ F ₇ OC(CF ₃ )FCF ₂ OCF ₂ CF ₂ C ₃ H ₆ -, C ₃ F ₇ OC(CF ₃ )FCF ₂ OC(CF ₃ )FC ₃ H ₆ -, CF ₃ CF ₂ CF ₂ OC(CF ₃ )FCF ₂ OC(CF ₃ )FCONHC ₃ H ₆ -.

As the organic group containing a (meth)acrylic group, examples thereof include CH ₂ =CHCOO-, CH ₂ =C(CH ₃ )COO-, CH ₂ =CHCOOC ₃ H ₆ -, CH ₂ =C(CH ₃ )COOC ₃ H ₆ -, CH ₂ =CHCOOC ₂ H ₄ O-, CH ₂ =C(CH ₃ )COOC ₂ H ₄ O-, etc. When the organic group containing a (meth)acrylic group is used as the substituent, it is more preferable that the bond to the Si atom is a Si-OC bond from the perspective of ease of industrial synthesis.

Among these, the compound having a (Y) cyclic siloxane skeleton preferably includes an organic group containing at least one fluorine atom, and more preferably includes a group having a perfluoroether structure. That is, the compound having a (Y) cyclic siloxane skeleton is preferably a fluorine compound having a cyclic siloxane skeleton and a perfluoroether structure. By having the above structure, the sliding properties of the cured resin layer surface can be further improved, and further, since the water droplet contact angle of the cured resin layer surface can be increased, high abrasion resistance can be exhibited.

Specifically, it is preferable that the compound having a (Y) cyclic siloxane skeleton is a fluorine compound represented by the following formula.

[Chemical Formula 3]

In the above formula, R is a hydrogen atom, a methyl group, an ethyl group, a propyl group or a phenyl group, Rf is an organic group containing a fluorine atom, Rx is an organic group containing a (meth)acryl group, and n is n≥2.

Specific examples of the organic group containing a fluorine atom and the (meth)acrylic group include the specific examples described above. In addition, from the viewpoint of abrasion resistance, n is preferably an integer of 2 to 20, and more preferably an integer of 2 to 10.

The content of the compound having a cyclic siloxane skeleton (Y) in the curable resin composition (B') is preferably 0.01 part by mass or more, more preferably 0.1 part by mass or more, further preferably 0.15 part by mass or more, particularly preferably 0.2 part by mass or more, and particularly preferably 0.3 part by mass or more, per 100 parts by mass of the urethane (meth)acrylate (X). Furthermore, the content of the compound having a cyclic siloxane skeleton (Y) in the curable resin composition (B') is preferably 20 parts by mass or less, more preferably 15 parts by mass or less, further preferably 10 parts by mass or less, and particularly preferably 5 parts by mass or less. By setting the content of the compound having a cyclic siloxane skeleton within the above range, it is easy to achieve both flexibility, curability and abrasion resistance of the cured resin layer (B).

(Other ingredients)

In addition to the compound having the above-mentioned (X) urethane (meth)acrylate and (Y) cyclic siloxane skeleton, the curable resin composition (B') may contain a photopolymerizable compound such as (meth)acrylate.

In addition, various additives can be appropriately blended into the curable resin composition (B') as needed within a range that does not impair the subject matter of the present invention. As the additives, for example, a photoinitiator, a light stabilizer, an antioxidant, an antistatic agent, a flame retardant, a leveling agent, a dispersant, a thixotropic agent (thickener), an antifoaming agent, etc. can be used in combination.

Here, as leveling agents, examples thereof include fluorine-based leveling agents, silicone-based leveling agents, and acrylic-based leveling agents. Among these, fluorine-based leveling agents are preferable as leveling agents in that they impart functions such as repelling water and oil well to the surface of the cured resin layer (B) and preventing adhesion of contaminants such as fingerprints.

(Photoinitiator (photopolymerization initiator))

When the curable resin composition (B') is a photocurable resin composition, it is preferable to contain a photoinitiator (photopolymerization initiator) in order to improve curability. The photoinitiator is a photopolymerization initiator, and a known one can be used. Examples of the photopolymerization initiator include a photoradical generator, a photoacid generator, and the like.

Among the photopolymerization initiators that can be used in the curable resin composition (B'), examples of photoradical generators include benzoin and its alkyl ethers, such as benzoin, benzoin methyl ether, benzoin ethyl ether, and benzoin isopropyl ether; Acetophenone, 2,2-dimethoxy-2-phenylacetophenone [e.g., trade name "Omnirad (registered trademark) 651", IGM RESINS product], 2,2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, 1-hydroxycyclohexylphenyl ketone [e.g., trade name "Omnirad (registered trademark) 184", IGM RESINS product], 2-hydroxy-2-methyl-1-phenylpropan-1-one [e.g., trade name "Omnirad (registered trademark) 1173", IGM RESINS product], 2-hydroxy-1-(4-(4-(2-hydroxy-2-methylpropionyl)benzyl)phenyl)-2-methylpropan-1-one [e.g., trade name Alkylphenones such as "Omnirad (registered trademark) 127, IGM RESINS product"], 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propan-1-one [e.g., trade name "Omnirad (registered trademark) 2959", IGM RESINS product], 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one [e.g., trade name "Omnirad (registered trademark) 907", IGM RESINS product], and 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-1-butanone; Examples thereof include phosphine oxides such as 2,4,6-trimethylbenzoyldiphenylphosphine oxide [e.g., product name "Omnirad (registered trademark) TPO", manufactured by IGM RESINS], bis-(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide [e.g., product name "Omnirad (registered trademark) 819", manufactured by IGM RESINS]; anthraquinones such as 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 1-chloroanthraquinone, and 2-amylanthraquinone; benzophenone and various derivatives thereof; formic acid derivatives such as methyl benzoyl formate and ethyl benzoyl formate, etc. These may be used alone or in combination of two or more.

Among these photoradical generators, from the viewpoint of the light resistance of the cured product, preferable ones are alkylphenones, phosphine oxides, and formic acid derivatives, and more preferable ones are 1-hydroxycyclohexylphenyl ketone, 2-hydroxy-1-(4-(4-(2-hydroxy-2-methylpropionyl)benzyl)phenyl)-2-methylpropan-1-one, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis-(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide, and methyl benzoyl formate, and particularly preferable ones are 1-hydroxycyclohexylphenyl ketone, 2-Hydroxy-1-(4-(4-(2-hydroxy-2-methylpropionyl)benzyl)phenyl)-2-methylpropan-1-one.

As the photoacid generator, known ones can be used, but among them, diaryl iodonium salts and triaryl sulfonium salts are preferable from the viewpoints of curability, acid generation efficiency, etc. Specific examples include anionic salts of di(alkyl-substituted)phenyliodonium (specifically, PF ₆ salt, SbF ₅ salt, tetrakis(perfluorophenyl)borate salt, etc.).

As a specific example of an anionic salt of (alkyl-substituted) phenyliodonium, a PF ₆ salt of dialkylphenyliodonium [trade name “Omniad (registered trademark) 250”, manufactured by IGM RESINS] is particularly preferable. These photoacid generators may be used alone or in combination of two or more.

From the viewpoint of improving curability, the content of the photoinitiator is preferably 0.01 parts by mass or more, more preferably 0.1 parts by mass or more, and particularly preferably 1 part by mass or more, per 100 parts by mass of the (X) urethane (meth)acrylate in the curable resin composition (B'). On the other hand, from the viewpoint of maintaining the stability of the coating liquid when the curable resin composition (B') is made into a solution and from the viewpoint of the planarity of the cured coating film, the content of the photoinitiator is preferably 20 parts by mass or less, more preferably 10 parts by mass or less, further preferably 7 parts by mass or less, and particularly preferably 5 parts by mass or less.

(Viscosity of curable resin composition)

The curable resin composition (A') and the curable resin composition (B') for forming the cured resin layer (A) and the curable resin layer (B) preferably have a viscosity at 25°C of 60 mPa·s or less, more preferably 30 mPa·s or less, still more preferably 20 mPa·s or less, still more preferably 15 mPa·s or less, and particularly preferably 12 mPa·s or less, as measured by an E-type viscometer in order to improve coatability. In addition, the viscosity of the curable resin composition is preferably 10 mPa·s or more.

<<Method for manufacturing laminated film>>

Both the curable resin layer (A) and the curable resin layer (B) (hereinafter, both are collectively referred to simply as the “curable resin layer”) can be formed by curing a curable resin composition, i.e., a composition having a curable performance. For example, the curable resin layer is formed by applying a curable resin composition onto a base film and curing it.

More specifically, the present laminated film can be manufactured by applying a curable resin composition (A') to at least one surface of a base film and curing it to form a cured resin layer (A), and then applying a curable resin composition (B') thereon and curing it to form a cured resin layer (B). At this time, the cured resin layer (A) and the cured resin layer (B) may be cured simultaneously.

In addition, after forming the cured resin layer (A), the film may be first wound into a roll shape, the film may be unwound again, and a curable resin composition (B') may be applied onto the cured resin layer (A) and cured to form the cured resin layer (B). In addition, after forming the cured resin layer (A) on the surface of the base film, a curable resin composition (B') may be continuously applied and cured to form the cured resin layer (B). In addition, the method for producing the laminated film is not limited to these methods at all.

As a method for applying the curable resin composition, for example, a conventionally known coating method such as air doctor coating, blade coating, rod coating, bar coating, knife coating, squeeze coating, impregnation coating, reverse roll coating, transfer roll coating, gravure coating, kiss roll coating, cast coating, spray coating, curtain coating, calendar coating, extrusion coating, etc. can be used.

Drying conditions are not particularly limited, and may be performed at around room temperature or by heating, for example, at about 25 to 120°C, preferably 50 to 100°C, and more preferably 60 to 90°C. In addition, the drying time is not particularly limited as long as the solvent can sufficiently volatilize, and is for example, about 10 seconds to 30 minutes, preferably about 15 seconds to 10 minutes.

The curing method of the curable resin composition can be appropriately selected depending on the curing mechanism of the curable resin composition. If the curable resin composition is a thermosetting resin composition, it can be cured by heating. In addition, if it is a photocurable resin composition, it can be cured by irradiating it with energy rays.

In the laminated film of the present invention, active energy rays that can be used when curing the photocurable resin composition include ultraviolet rays, electron rays, X-rays, infrared rays, and visible light. Among these active energy rays, ultraviolet rays and electron rays are preferable from the viewpoints of curability and prevention of resin deterioration.

The curing method of the curable resin composition is preferably curing by energy ray irradiation from the viewpoints of molding time and productivity, and from the viewpoint of being able to prevent thermal shrinkage and thermal deterioration of each member due to heating. The energy ray irradiation may be performed from any surface side, from the base film side, or from the opposite side of the base film.

When producing the laminated film of the present invention, if the curable resin composition is cured by irradiating with ultraviolet rays, various ultraviolet irradiation devices can be used, and a xenon lamp, a high-pressure mercury lamp, a metal halide lamp, an LED-UV lamp, etc. can be used as the light source. The amount of ultraviolet irradiation (unit: mJ/cm2) is preferably 50 to 3,000 mJ/cm2, and from the viewpoints of the curability of the curable resin composition, the flexibility of the cured product (cured film), etc., it is more preferably 100 to 1,000 mJ/cm2, and from the viewpoint of the flatness of the laminated film, it is further preferably 100 to 500 mJ/cm2. In addition, the amount of ultraviolet irradiation is appropriately determined depending on the reaction rate of the (meth)acryloyl group required in each curing step.

In particular, when using a laminated film under a strict environment, it is preferable to increase the amount of ultraviolet ray irradiation to adjust the surface hardness of the cured product of the curable resin composition.

In addition, when producing the laminated film of the present invention, when curing the curable resin composition by electron beam irradiation, various electron beam irradiation devices can be used. The electron beam irradiation dose (Mrad) is preferably 0.5 to 20 Mrad, and is more preferably 1 to 15 Mrad from the viewpoints of the curability of the curable resin composition, the flexibility of the cured product, and the prevention of damage to the substrate. In addition, the electron beam irradiation dose is appropriately determined according to the reaction rate of the (meth)acryloyl group required in each curing step.

<<Properties of laminated films>>

(My Steel Wool Castle (My SW Castle))

Since this laminated film has the above-described composition, it has excellent abrasion resistance. Specifically, the abrasion resistance can be evaluated by a steel wool resistance (SW resistance) test. The surface hardness of this laminated film, specifically, the SW resistance of the surface of the cured resin layer (B), can be evaluated as having excellent abrasion resistance when the rate of change in haze after 2000 round trips of steel wool is small. In addition, the steel wool resistance (SW resistance) test is performed by the following method. First, the uppermost surface of the cured resin layer (B) is rubbed with #0000 steel wool (trade name: BONSTAR, manufactured by Nippon Steel Wool Co., Ltd.) using a friction tester (RT-300 manufactured by Daiei Kagaku Seiki Seisakusho Co., Ltd.) while applying a load of 1 kg to a 2 cm by 2 cm (area of 4 cm2) at a speed of 50 mm/sec for 2,000 reciprocations, and the presence or absence of scratches on the surface of the cured resin layer (B) is visually checked. At that time, the haze value of the laminated film before and after the friction is measured. The change rate of the film haze after 2,000 reciprocations from the initial film haze (film haze before friction) is calculated, and if the change rate is less than 1%, the abrasion resistance is evaluated as excellent.

Change rate (%) = (film haze after friction - initial film haze) / initial film haze × 100

(water contact angle)

The water droplet contact angle on the cured resin layer side of the present laminated film is preferably 100° or more, more preferably 105° or more, and still more preferably 110° or more.

In addition, the water droplet contact angle after the uppermost surface of the cured resin layer (B) is subjected to 1,000 reciprocating frictions at a speed of 50 mm/sec while applying a load of 1 kg in a 2 cm by 2 cm dimension using a friction tester (RT-300 manufactured by Daiei Kagaku Seiki Seisakusho Co., Ltd.) with #0000 steel wool (trade name: BONSTAR, manufactured by Nippon Steel Wool Co., Ltd.) in a friction tester is preferably 90° or more, more preferably 95° or more, and still more preferably 100° or more. In addition, after the uppermost surface of the cured resin layer (B) is subjected to reciprocating friction 2,000 times at a speed of 50 mm/sec while applying a load of 1 kg in a 2 cm by 2 cm dimension using a friction tester (RT-300 manufactured by Daiei Kagaku Seiki Seisakusho Co., Ltd.) with #0000 steel wool (trade name: BONSTAR, manufactured by Nippon Steel Wool Co., Ltd.), the water contact angle is preferably 70° or higher, more preferably 75° or higher, and even more preferably 80° or higher. The fact that the water contact angle after 1,000 or 2,000 reciprocating frictions is within the above range indicates that a predetermined water repellency or higher is maintained even after the reciprocating friction, and indicates that the steel wool resistance (SW resistance) of the cured resin layer is good. In addition, the water droplet contact angle on the cured resin layer side of the laminated film is a value obtained by dropping a water droplet on the outermost surface (cured resin layer side) of the laminated film using an automatic contact angle meter and measuring the contact angle after 60 seconds.

(repeated bending)

Since the present laminated film has the above-described configuration, it has excellent repeated bending properties (bending resistance). By providing a cured resin layer (A) and a cured resin layer (B) on the surface of the present base film, and designing the configuration of the cured resin layer (B) within a specific range, the present base film can exhibit practical repeated bending properties. The repeated bending properties (bending resistance) can be evaluated, specifically, by the following method. The repeated bending test is performed using a bending tester (DLDMLH-FS manufactured by Yuasa System Equipment Co., Ltd.) with a minimum radius R = 1.5 so that the cured resin layer side of the laminated film becomes the inner surface. Then, the presence or absence of cracks in the cured resin layer on the inner surface is visually confirmed, and the number of repeated bends until cracks occur is measured. At that time, if no cracks occur even after bending 200,000 times or more, the repeated bending properties (bending resistance) can be evaluated as good.

(Light transmittance)

When the present laminated film is intended for optical use, it is preferable that the total light transmittance be 85% or higher, more preferably 86% or higher, and particularly preferably 88% or higher. In addition, the total light transmittance of the present laminated film is measured using a haze meter. Details of the measurement method are in accordance with the method described in the Examples.

(film haze)

When the present laminated film is intended for optical use, the film haze is preferably 1.0% or less, and more preferably 0.8% or less. In addition, the film haze of the present laminated film is measured with a haze meter. Details of the measurement method are in accordance with the method described in the examples.

(interference pattern)

Since this laminated film has the above-described configuration, the occurrence of interference patterns is suppressed. The interference pattern can be evaluated by the oscillation width of the light reflectance of 500 to 600 nm. The oscillation width of the light reflectance of 500 to 600 nm is preferably less than 1.1%, more preferably 1.0% or less, and particularly preferably less than 0.6%. By setting the oscillation width of the light reflectance of 500 to 600 nm within the above range, a film in which an interference pattern is difficult to be seen can be obtained. In addition, the oscillation width of the light reflectance of 500 to 600 nm is the oscillation width of the reflectance in the reflection simulation of light having a wavelength of 500 to 600 nm.

<<Characteristics and Uses of Laminated Film>>

As described above, the present laminated film is a laminated film having excellent practical repeated bending characteristics and abrasion resistance, and also having an interference pattern that is difficult to be seen. In the present laminated film, a high level of surface hardness (SW resistance, for example, 2,000 round trips or more) and repeated bending performance (bending durability, bending resistance, capable of being bent 200,000 times under the condition of R=1.5) are both achieved. It is presumed that these effects are due to the fact that by adjusting the composition of the cured resin layer (B), it is possible to reduce the stress transmission into the cured resin layer (B) applied when the present laminated film is bent.

In addition, when using the cured resin layer (B) as described above, there is no need to increase the tensile elasticity of the base film used extremely high.

In the past, when designing a laminated film having a surface layer with high surface hardness to have a target surface hardness at a desired level (for example, 2000 round trips or more in terms of SW resistance), it was necessary to review the structural design of the raw materials constituting the base film being used to further increase the tensile modulus.

In contrast, by utilizing the composition of the cured resin layer (B) as described above, it is possible to appropriately select a general-purpose base film distributed on the market, so there is an advantage in that the degree of freedom in selecting the base film increases. In addition, in the present embodiment, another layer may be provided between the cured resin layer (A) and the cured resin layer (B).

This laminated film has excellent abrasion resistance and practical repeated bending properties, and can also obtain wear resistance and transparency, so it can be suitably used for applications such as surface protection, display, and especially front panel. For example, it can be suitably used as a surface protection film, especially a surface protection film for a display, and especially a surface protection film for a flexible display. However, the applications of this laminated film are not limited to these applications.

[Second embodiment]

A laminated film of the present invention related to the second embodiment is a laminated film having a configuration in which a cured resin layer (C), a cured resin layer (A), and a cured resin layer (B) are sequentially laminated on at least one surface of a base film.

In addition, the present laminated film may have other layers as long as it has the above configuration.

<Film>

As for the substrate film, it is the same as that described in the first embodiment.

<Curing resin layer (C), (A) and (B)>

This laminated film has a laminated configuration in which a cured resin layer (C) is provided on at least one surface side of a base film, and a cured resin layer (A) and a cured resin layer (B) are additionally provided on the surface side.

<Curable resin composition>

The curable resin composition (C'), the curable resin composition (A') and the curable resin composition (B') for forming the curable resin layer (C), the curable resin layer (A) and the curable resin layer (B) are described below.

[Curable resin composition (C')]

The curable resin layer (C) is formed by a curable resin composition (C'). The curable resin composition (C') is characterized by containing an antistatic agent. The antistatic agent is not particularly limited as long as it has antistatic properties, but it is preferable to contain the following compound (C-a). As the curable resin composition (C'), it is more preferable to be formed from a resin composition containing (C-b) and (C-c) in addition to the following compound (C-a).

(C-a) A polymer doped with an anionic compound comprising a compound comprising thiophene and/or a thiophene derivative

(C-b) (Meth)acrylic polymer having a styrene structure

(C-c) (C-c1) polyglycerin, and (C-c2) at least one compound selected from alkylene oxide adducts to polyglycerin, or a derivative thereof

Compound (C-a) is a polymer doped with another anionic compound in a compound comprising (C-a1) thiophene or a thiophene derivative, or (C-a2) a polymer self-doped by having an anionic group in a compound comprising thiophene or a thiophene derivative. These substances are preferable because they exhibit excellent conductivity. The compound (C-a) may be one type, or two or more types may be used.

As the compound (C-a), for example, a compound of the following formula (C-1) or (C-2) is exemplified, which is obtained by polymerizing in the presence of a polyanion. A polymer obtained by polymerizing the following formula (C-1) in the presence of a polyanion and a polymer obtained by polymerizing the following formula (C-2) in the presence of a polyanion may be used together.

[Chemical Formula 4]

In the above formula (C-1), R ¹ and R ² each independently represent hydrogen or an aliphatic hydrocarbon group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, etc. having 1 to 20 carbon atoms.

[Chemical Formula 5]

In the above formula (C-2), n represents an integer from 1 to 4.

Examples of polyanions used in polymerization include poly(meth)acrylic acid, polymaleic acid, polystyrene sulfonic acid, and polyvinyl sulfonic acid. As a method for producing such polymers, a method such as that disclosed in Japanese Patent Laid-Open No. 7-90060 can be adopted.

In the present invention, in the compound of the above formula (2), n is 2 and polystyrene sulfonic acid is suitably used as the polyanion.

In addition, if these polyanions are acidic, some or all of them may be neutralized. Ammonia, organic amines, and alkali metal hydroxides are preferable as bases used for neutralization.

Compound (C-b) is a (meth)acrylic polymer having a styrene structure.

The styrene structure is styrene and styrene derivatives, and for example, an alkyl group such as a methyl group or an ethyl group, or a phenyl group may be introduced as a substituent to styrene. From the viewpoint of the effect of preventing precipitation of an oligomer by heat treatment, styrene substituted with an alkyl group having 4 or less carbon atoms or styrene without a substituent is preferable, and styrene is more preferable.

A (meth)acrylic polymer is a polymer having (meth)acrylic acid or a (meth)acrylic acid alkyl ester as a structural unit, and the compound (C-b) is a copolymer of styrene or a styrene derivative and (meth)acrylic acid or a (meth)acrylic acid alkyl ester.

In addition, in the present invention, when the expression "(meth)acrylic acid" is used, it is intended to mean one or both of "acrylic acid" and "methacrylic acid". In addition, similarly, "(meth)acrylate" is intended to mean one or both of "acrylate" and "methacrylate", and "(meth)acryloyl" is intended to mean one or both of "acryloyl" and "methacryloyl".

In addition, examples of the (meth)acrylic acid alkyl ester include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, sec-butyl (meth)acrylate, t-butyl (meth)acrylate, n-pentyl (meth)acrylate, n-hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, and the like. In addition, it may be a (meth)acrylic acid alkyl ester containing a hydroxyl group, such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, or 4-hydroxybutyl (meth)acrylate.

These may be used alone or in combination of two or more. Among these, from the viewpoint of the effect of preventing precipitation of oligomers by heat treatment, (meth)acrylic acid is preferable, and acrylic acid is more preferable. That is, the acrylic structure of the (meth)acrylic polymer is preferably a (meth)acrylic acid structure.

Additionally, the (meth)acrylic polymer may have a radically polymerizable double bond.

In addition, it is also possible to combine other polymerizable monomers copolymerizable with (meth)acrylic polymers having a styrene structure. Examples of copolymerizable monomers include: hydroxyl group-containing dibasic acid ester compounds such as monobutyl hydroxy fumarate and monobutyl hydroxy itaconate; various nitrogen-containing compounds such as (meth)acrylamide, diacetone acrylamide, N-methylolacrylamide and (meth)acrylonitrile; various vinyl esters such as vinyl propionate and vinyl acetate; various silicon-containing polymerizable monomers such as γ-methacryloxypropyltrimethoxysilane and vinyltrimethoxysilane; phosphorus-containing vinyl monomers; various halogenated vinyls such as vinyl chloride and vinylidene chloride; various conjugated dienes such as butadiene, etc.

The ratio of (meth)acrylic acid or (meth)acrylic acid alkyl ester in the (meth)acrylic polymer having a styrene structure is, for example, 3 mol% or more, preferably 5 to 40 mol%, more preferably 10 to 30 mol%, and even more preferably 15 to 25 mol%, based on the total amount of monomers constituting the (meth)acrylic polymer having a styrene structure. When the ratio of (meth)acrylic acid or (meth)acrylic acid alkyl ester is 3 mol% or more, the effect of preventing oligomer precipitation due to heat treatment is exhibited. In addition, when it is equal to or less than the upper limit, the ratio of the styrene structure increases, so that the durability of the antistatic performance can be ensured.

The ratio of styrene and styrene derivatives in the (meth)acrylic polymer having a styrene structure is, for example, 50 to 97 mol%, preferably 60 to 95 mol%, more preferably 70 to 90 mol%, and even more preferably 75 to 85 mol%, based on the total amount of monomers constituting the (meth)acrylic polymer having a styrene structure. When the ratio of styrene and styrene derivatives is equal to or greater than the lower limit above, the durability of antistatic performance is ensured, and when it is equal to or less than the upper limit above, the effect of preventing oligomer precipitation from the base film (polyester film) due to heat treatment is ensured.

The mechanism by which precipitation of the oligomer component contained in the polyester film is suppressed is speculated as follows. When the polyester film is heated above the glass transition point, the oligomer component precipitates on the surface thereof, but it is speculated that by forming a cured resin layer made of a resin composition using a (meth)acrylic polymer having a styrene structure on the polyester film, the aromatic rings contained in the styrene form a structure in which they overlap in parallel with the film, thereby inhibiting the precipitation of the oligomer component.

Compound (C-c) is at least one compound or derivative thereof selected from (C-c1) polyglycerin, and (C-c2) an alkylene oxide adduct to polyglycerin. Polyglycerin is a compound represented by the following general formula (C-3).

[Chemical formula 6]

In the above formula, n is 2 or more, and in the present invention, n in the formula is usually in the range of 2 to 20, preferably 3 to 15, and more preferably 3 to 12.

An alkylene oxide adduct to polyglycerin has a structure in which an alkylene oxide is added to the hydroxyl group of polyglycerin represented by the general formula (C-3).

Here, the structure of the alkylene oxide added to each hydroxyl group of the polyglycerin skeleton may be different. In addition, it is sufficient that it is added to at least one hydroxyl group of the molecules, and it is not necessary for the alkylene oxide or its derivative to be added to all the hydroxyl groups.

As an alkylene oxide added to polyglycerin, ethylene oxide or propylene oxide is preferable. If the alkylene chain of the alkylene oxide becomes too long, the hydrophobicity becomes strong, the dispersibility in the coating solution deteriorates, and the antistatic property and transparency of the cured resin layer tend to deteriorate. Ethylene oxide is particularly preferable.

In addition, the number of additional components is preferably in the range of 200 to 2000, more preferably in the range of 300 to 1000, and even more preferably in the range of 400 to 900, as a number average molecular weight as a final compound.

The above polyglycerin or alkylene oxide adduct to polyglycerin may be used alone or in combination of two or more types.

The resin composition (C') related to the present invention may contain a crosslinking agent for the purpose of improving the durability of the cured resin layer (C), particularly the durability of the antistatic performance.

As the crosslinking agent, various known crosslinking agents can be used, and examples thereof include melamine compounds, epoxy compounds, isocyanate compounds, carbodiimide compounds, oxazoline compounds, and silane coupling compounds. Among these, melamine compounds, epoxy compounds, isocyanate compounds, and carbodiimide compounds are preferable in that they suppress the deterioration of antistatic properties after exposure to air, and melamine compounds are more preferable in that they can suppress oligomer precipitation more effectively. The crosslinking agent such as a melamine compound is as described in the first embodiment, and can be used in the same manner in the resin composition (C').

In the resin composition (C') related to the present invention, it is also possible to contain various conventionally known polymers, such as polyester resin, acrylic resin, urethane resin, etc., as a binder in order to improve the coating appearance or transparency of the cured resin layer (C).

In addition, within a range that does not impair the spirit of the present invention, it is also possible to use particles in combination with the resin composition (C') related to the present invention for the purpose of improving the blocking property or sliding property of the cured resin layer (C).

The proportion of the compound (C-a) in the nonvolatile component in the resin composition (C') related to the present invention is usually 2 to 30 mass%, more preferably 3 to 15 mass%, and even more preferably 5 to 12 mass%. When the proportion of the compound (C-a) is equal to or lower than the upper limit, the strength and transparency of the cured resin layer are good. On the other hand, when the proportion of the compound (C-a) is equal to or higher than the lower limit, sufficient antistatic performance is obtained, and furthermore, the antistatic performance does not deteriorate after exposure to air.

The proportion of the compound (C-b) in the non-volatile components in the resin composition (C') related to the present invention is usually in the range of 5 to 80 mass%, preferably 10 to 50 mass%, and more preferably 15 to 40 mass%.

When the ratio of compound (C-b) is below the above upper limit, since the ratio of other components increases, sufficient antistatic properties are obtained, and also the appearance of the coating becomes good. On the other hand, when the ratio of compound (C-b) is above the above lower limit, precipitation of oligomers can be sufficiently suppressed, and also sufficient film-forming properties can be secured, so that a uniform coating film is obtained.

The proportion of the compound (C-c) in the nonvolatile component of the resin composition A related to the present invention is usually in the range of 10 to 85 mass%, preferably 40 to 70 mass%, and more preferably 45 to 65 mass%. When the proportion of the compound (C-c) is equal to or lower than the upper limit, the proportions of other components become high, so that the antistatic property and film-forming property become sufficient. On the other hand, when the proportion of the compound (C-c) is equal to or higher than the lower limit, the transparency of the cured resin layer becomes good.

In the case where a crosslinking agent is used in combination in the resin composition (C') related to the present invention, the proportion of the crosslinking agent in the nonvolatile components in the resin composition (C') is usually 30 mass% or less, preferably 1 to 25 mass%, and more preferably 3 to 20 mass%. By using the crosslinking agent in this range, sufficient antistatic performance is obtained, and furthermore, deterioration of antistatic performance after exposure to air can be suppressed, and the strength of the cured resin layer (C) is improved.

(Thickness of the cured resin layer (C))

The thickness of the cured resin layer (C) is preferably 0.002 µm or more and 1.0 µm or less, more preferably 0.005 µm or more and 0.25 µm or less, and even more preferably 0.02 µm or more and 0.10 µm or less. When the thickness of the cured resin layer is within the above range, precipitation of the oligomer component can be suppressed and also good antistatic properties can be imparted.

In addition, it can be assumed that unreacted substances of various compounds of the resin composition (C'), compounds after reaction, or mixtures thereof exist in the cured resin layer (C).

[Curable resin composition (A')]

The cured resin layer (A) is formed by a curable resin composition (A'). The curable resin composition (A') is as described in the first embodiment.

((A-c) particle)

It is preferable that the curable resin composition (A') contains particles (A-c). As the particles, it is preferable to contain a metal oxide from the viewpoint of imparting a high refractive index to the curable resin layer (A). By increasing the refractive index, interference patterns can be suppressed.

(metal oxide)

As the metal oxide, it is preferable to use a metal oxide having a high refractive index, and it is preferable to use one having a refractive index of 1.7 or more at 550 nm. Specific examples of the metal oxide include zirconium oxide, aluminum oxide, titanium oxide, tin oxide, yttrium oxide, antimony oxide, indium oxide, zinc oxide, antimony tin oxide, indium tin oxide, etc., and these may be used alone or in combination of two or more. Among these, zirconium oxide and titanium oxide are more suitably used, and in particular, zirconium oxide is more suitably used from the viewpoint of weather resistance.

Metal oxides are preferably used in the form of particles because there is a concern that adhesion may be reduced depending on the form of use, and furthermore, the average particle diameter is preferably 100 nm or less, more preferably 50 nm or less, and even more preferably 25 nm or less, from the viewpoint of transparency. Furthermore, there is no particular limitation on the lower limit of the average particle diameter, but from the viewpoint of dispersibility, it is preferably 5 nm or more, and more preferably 10 nm or more.

In addition, the curable resin composition (A') may contain particles other than the metal oxide described above for the purpose of improving the adhesiveness and sliding properties of the curable resin layer (A). The average particle diameter of the particles other than the metal oxide is preferably 1.0 µm or less, more preferably 0.5 µm or less, and particularly preferably 0.2 µm or less from the viewpoint of transparency of the present laminated film. In addition, the lower limit of the average particle diameter is not particularly limited, but is preferably 20 nm or more, and more preferably 40 nm or more, from the viewpoint of dispersibility.

Specific examples of particles other than the metal oxides described above include silica, kaolin, calcium carbonate, zirconia, organic particles, etc., and among these, silica is suitably used from the viewpoint of sliding properties.

In addition, as particles, it is preferable to use two types of particles with different particle sizes from the viewpoint of imparting activity, and furthermore, it is preferable to use a combination of metal oxide and particles other than metal oxide with different particle sizes.

The above average particle size is a value measured by, for example, laser diffraction/scattering, dynamic light scattering (DLS), centrifugal sedimentation, particle trajectory analysis (PTA), scanning electron microscopy (SEM), etc.; however, if it is a commercial product, the catalog value can be adopted.

As a ratio of the non-volatile component in the curable resin composition (A') forming the cured resin layer (A), the (A-c) particles are usually in the range of 5 to 80 mass%, preferably 10 to 80 mass%, more preferably 20 to 80 mass%, and particularly preferably 40 to 80 mass%. By satisfying the above range, both transparency of the film and low-interference effect can be achieved.

In particular, a more excellent low-interference effect is obtained by combining particles such as metal compounds and the polycyclic polyester resin described above.

The content of the binder resin (A-a) in the curable resin composition (A') is usually 1 to 60 mass%, preferably 3 to 40 mass%, and more preferably 5 to 30 mass%. By satisfying the above range, good film-forming properties can be secured.

The content of the crosslinking agent (A-b) in the curable resin composition (A') is usually 2 to 80 mass%, preferably 2 to 60 mass%, and more preferably 2 to 40 mass%. By satisfying the above range, the adhesion to the cured resin layer (B) becomes good.

The content of the acrylic resin in the curable resin composition (A') is preferably 80 mass% or less, more preferably 5 to 70 mass%, and particularly preferably 10 to 50 mass%. By satisfying the above range, the refractive index of the cured resin layer (A) itself can be easily adjusted, and interference unevenness after the formation of the cured resin layer (B) can be easily reduced. In addition, the proportion of the acrylic resin can be obtained, for example, by dissolving and extracting the coating layer in a suitable solvent or warm water, fractionating it by chromatography, analyzing the structure by NMR or IR, and further analyzing it by pyrolysis GC-MS (gas chromatography mass spectrometry) or optical analysis.

[Curable resin composition (B')]

The cured resin layer (B) is formed by a curable resin composition (B'). The curable resin composition (B') contains (X) a urethane (meth)acrylate and a fluorine compound having a cyclic siloxane skeleton and a perfluoroether structure.

The mass average molecular weight of the curable resin composition (B') is preferably 100 or more, more preferably 200 or more, and more preferably 400 or more. On the other hand, with respect to the upper limit, it is preferably 500,000 or less, and more preferably 400,000 or less, and more preferably 250,000 or less.

In addition, in the present invention, when the expression "(meth)acrylic" is used, it is intended to mean one or both of "acrylic" and "methacrylic". The same applies to "(meth)acrylate" and "(meth)acryloyl". In addition, "(poly)propylene glycol" is intended to mean one or both of "propylene glycol" and "polypropylene glycol". "(poly)ethylene glycol" is intended to have the same meaning.

The (X) urethane (meth)acrylate in the curable resin composition (B') is the same as that described in the first embodiment.

(Fluorine compound having a cyclic siloxane skeleton and a perfluoroether structure)

The curable resin composition (B') forming the cured resin layer (B) contains a fluorine compound having a cyclic siloxane skeleton and a perfluoroether structure. As the fluorine compound, for example, a fluorine compound represented by the following general formula (4) can be mentioned.

[Chemical formula 7]

In formula (4), R ³ and R ⁴ are each independently an organic group having 1 to 12 carbon atoms which may have a substituent; m is an integer of 3 to 10.

In equation (4), m is preferably an integer from 3 to 6 in terms of abrasion resistance, and 3 or 4 is particularly preferable.

Examples of the organic group for R ³ and R ⁴ include chain alkyl groups such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, a butyl group, an isobutyl group, a sec-butyl group, and a t-butyl group; an alkoxy group such as a methoxy group and an ethoxy group; a cyclic alkyl group such as a cyclohexyl group and a norbornanyl group; an alkenyl group such as a vinyl group, a 1-propenyl group, an allyl group, a butenyl group, and a 1,3-butadienyl group; an alkynyl group such as an ethynyl group, a propynyl group, and a butynyl group; a halogenated alkyl group such as a trifluoromethyl group; an alkyl group having a saturated heterocyclic group such as a 3-pyrrolidinopropyl group; an aryl group such as a phenyl group which may have an alkyl substituent; an aralkyl group such as a phenylmethyl group and a phenylethyl group; etc.

In addition, the organic group for R ³ , R ⁴ may have an oxygen atom between carbon atoms, or may have an amide bond between carbon atoms. In addition, the organic group for R ³ , R ⁴ may be a perfluoro organic group in which all hydrogen atoms bonded to the carbon atoms are replaced with fluorine atoms.

When imparting water repellency to the coating layer, a perfluoroorganic group which may have an oxygen atom between carbon atoms is preferable as at least a part of R ³ and R ⁴ , and a perfluoroalkylene group which may have an oxygen atom between carbon atoms is more preferable.

As the substituent that the organic group for R ³ and R ⁴ may have, examples thereof include a hydroxy group, a halogen atom (e.g., a fluorine atom, a chlorine atom, a bromine atom, an iodine atom), a (meth)acryloyl group, etc. Among them, a hydroxy group, a halogen atom, and a (meth)acryloyl group are preferable.

In addition, the fluorine compound having a cyclic siloxane skeleton and a perfluoroether structure is preferably a compound having a perfluoroether structure at the terminal. That is, it is preferably a fluorine compound in which a perfluoroether skeleton is bonded to a cyclic siloxane skeleton in a single-terminal structure. By having the above structure, the sliding properties of the cured resin layer surface can be further improved, resulting in excellent abrasion resistance.

The fluorine compound having a siloxane skeleton and a perfluoroether structure may be a reactive siloxane compound or a non-reactive siloxane compound.

Reactive siloxane compounds are compounds having a reactive functional group and a siloxane bond. Examples of the reactive functional group include an amino group, an epoxy group, a carboxyl group, a carbinol group, a (meth)acrylic group, a mercapto group, and a phenol group.

Non-reactive siloxane compounds are compounds that do not have reactive functional groups and have siloxane bonds. Examples thereof include polyether-modified siloxane compounds, methylstyryl-modified siloxane compounds, alkyl-modified siloxane compounds, higher fatty acid ester-modified siloxane compounds, hydrophilic special-modified siloxane compounds, higher alkoxy-modified siloxane compounds, and fluorine-modified siloxane compounds.

Examples of methods for synthesizing a fluorine compound having a cyclic siloxane skeleton and a perfluoroether structure include a method in which an organic group containing three or more fluorine atoms and a siloxane compound having three or more Si-H groups undergoes an addition reaction with allyl (meth)acrylate or the like, and a method in which an organic group containing three or more fluorine atoms and a siloxane compound having three or more Si-H groups undergoes a dehydrogenation reaction with a (meth)acrylic compound having an OH group such as hydroxyethyl acrylate.

Among these methods, the method using an addition reaction is preferable. Although there is a possibility that the (meth)acrylic group may undergo an addition reaction, in the dehydrogenation reaction, the reaction proceeds while maintaining the (meth)acrylic group by using a catalyst such as an amine, so that the target compound can be easily obtained.

In the cured resin layer (B), i.e., in the curable resin composition (B'), it is preferable to mix a fluorine compound having a cyclic siloxane skeleton and a perfluoroether structure in the range of 0.1 to 30 parts by mass with respect to 100 parts by mass of (X) urethane (meth)acrylate, more preferably in the range of 0.15 to 20 parts by mass, still more preferably in the range of 0.2 to 10 parts by mass, and particularly preferably in the range of 0.3 to 5 parts by mass. When the content of the fluorine compound is in the above range, both curability and abrasion resistance are particularly good.

(menstruum)

The curable resin composition (B') may be made into a coating liquid by being diluted with a solvent. The curable resin composition (B') may be made into a curable resin layer (B) by applying it as a liquid coating liquid on a curable resin layer (A), drying it, and further curing it. Each component constituting the curable resin composition (B') may be dissolved in a solvent, or may be dispersed in the solvent.

As a solvent, the same one as that used in the curable resin composition (B') of the first embodiment can be used. In addition, the amount of organic solvent used is the same as that used in the curable resin composition (B') of the first embodiment.

In addition, other components described in the first embodiment may be added to the curable resin composition (B'). In addition, the type and content of the photoinitiator, photopolymerization initiator, and photoacid generator may be the same as those of the curable resin composition (B') of the first embodiment.

Additionally, the viscosity of the curable resin compositions (A') and (B') is the same as that of the curable resin compositions (A') and (B') in the first embodiment.

(particulate)

It is also preferable to contain fine particles in the curable resin composition (B') to increase the surface hardness (abrasion resistance) of the curable resin layer (B).

Examples of the fine particles include inorganic particles such as silica, calcium carbonate, magnesium carbonate, barium carbonate, calcium sulfate, calcium phosphate, magnesium phosphate, kaolin, aluminum oxide (alumina), titanium oxide, etc.; and organic particles such as acrylic resin, styrene resin, urea resin, phenol resin, epoxy resin, benzoguanamine resin, etc. Among them, it is preferable to use inorganic particles, and aluminum oxide is particularly preferable because it is easy to adjust the abrasion resistance.

In addition, from the viewpoint of transparency, the average particle diameter of the above fine particles is preferably 25 nm or less, more preferably 20 nm or less, and even more preferably 15 nm or less. In addition, with respect to the lower limit of the average particle diameter, there is no particular limitation, but from the viewpoint of dispersibility, it is preferably 5 nm or more, and more preferably 10 nm or more.

The content of fine particles relative to the total amount (solid content) of (X) urethane (meth)acrylate and fine particles in the curable resin composition (B') is preferably 5 to 40 mass% or more, more preferably 10 to 35 mass% or more, and even more preferably 15 to 30 mass% or more. By setting the content of fine particles within the above range, the laminated film can achieve both excellent abrasion resistance and antistatic properties, and can also be satisfactory in transparency.

(Thickness of cured resin layer)

Regarding the thickness of the cured resin layer (B), it is the same as the cured resin layer (B) in embodiment 1 described above. In addition, regarding the total thickness of the cured resin layer (A) and the cured resin layer (B), it is the same as in embodiment 1, but in terms of making it easy to adjust the balance between excellent abrasion resistance and antistatic properties of the laminated film, it is preferable that the thickness of the cured resin layer (C) is 5.0 µm or less.

It is preferable that the light transmittance of the surface of the cured resin layer (B) at a wavelength of 380 nm is 3.0% or less. If the light transmittance is 3.0% or less, it is advantageous in that the partner material to be bonded can be prevented from deteriorating due to ultraviolet rays. From the above viewpoint, the light transmittance at a wavelength of 380 nm is more preferably 2.8% or less.

In addition, it is preferable that the maximum reflectivity difference of the surface of the cured resin layer (B) at a wavelength of 500 to 600 nm is 1.5% or less. If the maximum reflectivity difference (the oscillation amplitude of the light transmittance) is 1.5% or less, it is advantageous in that interference patterns become difficult to see. From the above viewpoint, the maximum reflectivity difference is more preferably 1.0% or less, more preferably 0.5% or less, and particularly preferably 0.3% or less.

Additionally, the maximum reflectance difference in the present invention means the difference between the maximum and minimum reflectance values at a wavelength of 500 to 600 nm.

<Surface condition of each layer>

The surface of the cured resin layer (C) and the surface of the cured resin layer (A) may be uneven or flat, but from the perspective of appearance (surface gloss), it is preferable that they be flat.

In addition, the surface of the cured resin layer (B) may be either uneven or flat, but from the viewpoint of appearance (surface gloss), it is preferable to be flat. On the other hand, from the viewpoint of imparting anti-glare properties, it is preferable to be uneven. Depending on the required characteristics, it can be arbitrarily selected.

<<Method for manufacturing laminated film>>

The cured resin layer (C), the cured resin layer (A), and the cured resin layer (B) can all be formed by curing a curable resin composition. That is, the cured resin layer is formed by, for example, applying a curable resin composition having a mass average molecular weight in the range of 1,000 to 500,000 onto a base film and curing it.

More specifically, the present laminated film can be manufactured by applying a curable resin composition (C') to at least one surface of a base film, curing it to form a cured resin layer (C), then applying a curable resin composition (A') and curing it to form a cured resin layer (A), and then applying a curable resin composition (B') thereon and curing it to form a cured resin layer (B). At this time, the curing of the cured resin layer (C), the cured resin layer (A), and the cured resin layer (B) may be performed separately when forming each layer, or curing may be performed simultaneously after applying a plurality of layers.

In addition, after forming the cured resin layer (C), or after forming the cured resin layer (C) and the cured resin layer (A), the film may be first wound into a roll shape, the film may be unwound again, and a curable resin composition (B') may be applied onto the cured resin layer (A) and cured to form the cured resin layer (B). In addition, a cured resin layer (C) may be formed on the surface of a base film, a curable resin layer (A) may be formed thereon, and then a curable resin composition (B') may be continuously applied and cured to form the cured resin layer (B). In addition, the method for producing a laminated film is not limited to these methods at all.

<Method for forming a cured resin layer>

Regarding the method for applying the curable resin composition, drying conditions, and curing method, the same method and conditions as those described in the first embodiment can be used.

<<Properties of laminated films>>

(My SW)

In this laminated film, the surface hardness of the film, specifically, the SW resistance (#0000 steel wool, load 1 kg) of the surface of the cured resin layer (B) can be increased to 2000 times or more.

(repeated bending)

The laminated film having the above configuration can further enhance practical repeated bending characteristics by providing a cured resin layer (C), a cured resin layer (A), and a cured resin layer (B) on the surface of the base film, and further comprising a cured resin layer (B) composed of a specific component. Specifically, the laminated film can obtain durability in which no cracks are generated even when folded 200,000 times or more in a repeated bending performance evaluation (under the condition of bending resistance, R = 1.5).

(Light transmittance)

When the present laminated film is intended for optical use, it is preferable that the total light transmittance be 85% or higher, more preferably 86% or higher, and particularly preferably 88% or higher. In addition, the total light transmittance was measured using a haze meter. Details of the measurement method are in accordance with the method described in the examples.

(film haze)

When the present laminated film is intended for optical use, it is preferable that the film haze be 1.0% or less, more preferably 0.8% or less, and particularly preferably 0.6% or less. In addition, the film haze was measured with a haze meter. Details of the measurement method are in accordance with the method described in the examples.

(interference pattern)

By setting the vibration range of the light transmittance of 500 to 600 nm to 1.5% or less, preferably 1.0% or less, more preferably 0.5% or less, a film in which interference patterns are difficult to be seen can be obtained.

(anti-warfare)

The surface resistivity of the surface of the cured resin layer (B) is not particularly limited, but is, for example, 1×10 ¹² Ω/□ or less, preferably 1×10 ¹¹ Ω/□ or less. There is no particular lower limit to the surface resistivity, but considering the cost of the antistatic agent, it is preferably 1×10 ⁴ Ω/□ or more. The lower the surface resistivity of the cured resin layer (B), the better the antistatic property, and for example, in a process of peeling a functional layer such as an adhesive layer provided on the cured resin layer (B), peeling electrification can be suppressed, thereby preventing adhesion of foreign substances, etc. The surface resistivity of the cured resin layer (B) can be made within the above range, for example, by containing an antistatic agent in the cured resin layer (C).

<<Characteristics and Uses of Laminated Film>>

This laminated film can achieve both a high level of surface hardness (SW resistance, for example, 2,000 round trips or more) and repeated bending performance (bending durability, bending resistance, can be bent 200,000 times under the condition of R=1.5). It is presumed that this is because by adjusting the composition of the cured resin layer (B), it becomes possible to reduce the overall stress applied to the cured resin layer (B) when the present laminated film is bent.

In addition, by using the cured resin layer (B) as described above, there is no need to increase the tensile elasticity of the base film used extremely high.

In the past, when designing a laminated film having a surface layer with high surface hardness to have a target surface hardness at a desired level (for example, 2000 round trips or more in terms of SW resistance), it was necessary to review the structural design of the raw materials constituting the base film being used to further increase the tensile modulus.

In contrast, by utilizing the composition of the cured resin layer (B) as described above, it is possible to appropriately select a general-purpose base film distributed on the market, so there is an advantage of increased freedom in selecting the base film.

This laminated film has excellent abrasion resistance and practical repeated bending properties, and can also obtain transparency and antistatic properties, so it can be used for applications such as surface protection, display, and especially front panel. For example, it can be suitably used as a surface protection film, especially a surface protection film for a display, and especially a surface protection film for a flexible display. However, the applications of this laminated film are not limited to these applications.

<<Explanation of phrase>>

In the present invention, even when referred to as a “film,” it is considered to include a “sheet,” and even when referred to as a “sheet,” it is considered to include a “film.”

In addition, in this specification, when it is written as “X~Y” (X and Y are arbitrary numbers), unless specifically stated otherwise, it includes the meaning of “more than X and less than Y,” as well as the meaning of “preferably greater than X” or “preferably less than Y.”

In addition, when it is written as “X or more” (X is any number), it includes the meaning of “preferably greater than X” unless otherwise stated, and when it is written as “Y or less” (Y is any number), it also includes the meaning of “preferably less than Y” unless otherwise stated.

[Third embodiment]

A laminated film of the present invention related to the third embodiment has a configuration in which a cured resin layer (A) and a cured resin layer (D) are sequentially laminated on at least one surface of a base film, wherein the cured resin layer (A) is a cured product of a curable resin composition (A') containing (A-a) a binder, (A-b) a crosslinking agent, and (A-c) particles, and wherein the cured resin layer (D) is a cured product of a curable resin composition (D') containing a trifunctional or higher (meth)acrylate (D-a), a quaternary ammonium base-containing polymer (D-b), and a compound (D-c) having a fluorine atom-containing structure and a cyclic siloxane structure.

The laminated film of the present invention, by having the above-described configuration, can achieve both excellent antistatic properties and antifouling properties, while at the same time making it difficult for interference patterns to be seen and satisfying practical repeated bending characteristics and abrasion resistance, and in particular, by including a specific compound, that is, a curable resin composition (D'), a quaternary ammonium base-containing polymer (D-b) and a compound (D-c) having a fluorine atom-containing structure and a cyclic siloxane structure, in addition to the antistatic properties and antifouling properties, it can also achieve excellent wear resistance.

With respect to the cured resin layer (A), it is the same as described in the first embodiment. That is, the cured resin layer (A) is a cured product of a curable resin composition (A') containing (A-a) a binder, (A-b) a crosslinking agent, and (A-c) particles, and with respect to the (A-a) binder, (A-b) crosslinking agent, and (A-c) particles, it is the same as described in the first embodiment. Hereinafter, the cured resin layer (D) will be described.

[Curable resin composition (D')]

The curable resin composition (D') contains a trifunctional or higher (meth)acrylate (D-a), a quaternary ammonium base-containing polymer (D-b), and a compound (D-c) having a fluorine atom-containing structure and a cyclic siloxane structure.

(Meth)acrylate (D-a) with more than 3 functions)

The trifunctional or higher (meth)acrylate (D-a) may be a compound having three or more (meth)acryloyl groups per molecule, and is not particularly limited. In addition, the trifunctional or higher (meth)acrylate (D-a) may be a monomer or an oligomer.

In the present invention, it is preferable to use urethane (meth)acrylate (D-a-u) from the viewpoint of balance between repeated bending characteristics and abrasion resistance and adjustment of refractive index.

As the three or more functional (meth)acrylates (D-a-m) of the monomer, for example, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol tri(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, tri(meth)acryloyloxyethoxytrimethylolpropane, glycerin polyglycidyl ether poly(meth)acrylate, isocyanuric acid ethylene oxide-modified poly(meth)acrylate, ethylene oxide-modified dipentaerythritol penta(meth)acrylate, ethylene oxide-modified Examples thereof include dipentaerythritol hexa(meth)acrylate, ethylene oxide-modified pentaerythritol tri(meth)acrylate, ethylene oxide-modified pentaerythritol tetra(meth)acrylate, succinic acid-modified pentaerythritol poly(meth)acrylate, and caprolactone-modified pentaerythritol poly(meth)acrylate.

As an example of a trifunctional or higher functional (meth)acrylate (D-a-o) of an oligomer, a trifunctional or higher functional urethane (meth)acrylate (D-a-u) can be mentioned. A trifunctional or higher functional urethane (meth)acrylate is a compound having three or more (meth)acryloyl groups and one or more urethane bonds.

Urethane (meth)acrylate is produced by reacting an isocyanate compound and a hydroxyl group-containing (meth)acrylate compound, or is produced by reacting an isocyanate compound, a polyol compound, and a hydroxyl group-containing (meth)acrylate compound. Urethane (meth)acrylate can be used alone or in combination of two or more.

As the trifunctional or higher urethane (meth)acrylate, for example, (1) a reaction product of a hydroxyl group-containing (meth)acrylate compound (D-a1) containing at least one (meth)acryloyl group and a polyvalent isocyanate compound (D-a2); (2) a reaction product of the above (D-a1), the above (D-a2) and a polyol compound (D-a3); (3) a reaction product of a hydroxyl group-containing (meth)acrylate compound (D-a4) containing a hydroxyl group and three or more (meth)acryloyl groups and a monoisocyanate compound (D-a5); etc.

Among these, as a trifunctional or higher urethane (meth)acrylate (D-a-u) having excellent antifouling and abrasion resistance, etc., (1) a reaction product of a hydroxyl group-containing (meth)acrylate compound (D-a1) and a polyvalent isocyanate compound (D-a2) is preferable.

Regarding a hydroxyl group-containing (meth)acrylate compound (D-a1) containing one or more (meth)acryloyl groups, examples of the hydroxyl group-containing (meth)acrylate compound containing one (meth)acryloyl group include hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, and 6-hydroxyhexyl (meth)acrylate, 2-hydroxyethyl acryloyl phosphate, 2-(meth)acryloyloxyethyl-2-hydroxypropyl phthalate, and caprolactone-modified 2-hydroxyethyl (meth)acrylate. Examples thereof include dipropylene glycol (meth)acrylate, fatty acid-modified glycidyl (meth)acrylate, polyethylene glycol mono (meth)acrylate, and polypropylene glycol mono (meth)acrylate.

In addition, as hydroxyl group-containing (meth)acrylate compounds containing two (meth)acryloyl groups, examples thereof include glycerin di(meth)acrylate, 2-hydroxy-3-acryloyl-oxypropyl methacrylate, and pentaerythritol di(meth)acrylate.

A hydroxyl group-containing (meth)acrylate compound (D-a1) containing at least one (meth)acryloyl group may be used alone, or two or more types may be used in combination.

Examples of the polyisocyanate compounds (D-a2) include aromatic polyisocyanates such as tolylene diisocyanate, diphenylmethane diisocyanate, polyphenylmethane polyisocyanate, modified diphenylmethane diisocyanate, xylylene diisocyanate, tetramethylxylylene diisocyanate, phenylene diisocyanate, and naphthalene diisocyanate; aliphatic polyisocyanates such as pentamethylene diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, lysine diisocyanate, and lysine triisocyanate; alicyclic polyisocyanates such as hydrogenated diphenylmethane diisocyanate, hydrogenated xylylene diisocyanate, isophorone diisocyanate, and norbornene diisocyanate; Examples thereof include terpolymer compounds, multimer compounds of these polyisocyanates; allophanate-type polyisocyanates; biuret-type polyisocyanates; water-dispersible polyisocyanates; and the like.

Among these, from the viewpoint of stability during the urethane reaction, diisocyanate compounds are preferable, and aliphatic diisocyanates such as pentamethylene diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, and lysine diisocyanate; and alicyclic diisocyanates such as hydrogenated diphenylmethane diisocyanate, hydrogenated xylylene diisocyanate, isophorone diisocyanate, norbornene diisocyanate, and 1,3-bis(isocyanatemethyl)cyclohexane are more preferable.

In terms of small curing shrinkage, isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated xylylene diisocyanate, and norbornene diisocyanate are preferable, and in terms of excellent reactivity and versatility, isophorone diisocyanate is particularly preferable.

One type of polyisocyanate compound (D-a2) may be used alone, or two or more types may be used in combination.

The polyol compound (D-a3) is not particularly limited as long as it is a compound containing two or more hydroxyl groups. Examples thereof include aliphatic polyols, alicyclic polyols, polyether polyols, polyester polyols, polycarbonate polyols, polyolefin polyols, polybutadiene polyols, polyisoprene polyols, (meth)acrylic polyols, etc.

Examples of aliphatic polyols include aliphatic alcohols containing two hydroxyl groups, such as ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, trimethylene glycol, dimethylolpropane, neopentyl glycol, 2,2-diethyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-propanediol, 1,4-tetramethylenediol, 1,3-tetramethylenediol, 2-methyl-1,3-trimethylenediol, 1,5-pentamethylenediol, 1,6-hexamethylenediol, 3-methyl-1,5-pentamethylenediol, 2,4-diethyl-1,5-pentamethylenediol, pentaerythritol diacrylate, 1,9-nonanediol, and 2-methyl-1,8-octanediol; sugar alcohols such as xylitol and sorbitol; Aliphatic alcohols containing three or more hydroxyl groups, such as glycerin, trimethylolpropane, and trimethylolethane; etc.

Examples of alicyclic polyols include cyclohexanediols such as 1,4-cyclohexanediol and cyclohexyldimethanol, hydrogenated bisphenols such as hydrogenated bisphenol A, and tricyclodecane dimethanol.

Examples of polyether polyols include alkylene structure-containing polyether polyols such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polybutylene glycol, polypentamethylene glycol, and polyhexamethylene glycol; and random copolymers and block copolymers of these polyalkylene glycols.

As polyester polyols, examples thereof include condensation polymers of polyhydric alcohols and polyhydric carboxylic acids; ring-opening polymers of cyclic esters (lactones); reaction products of three types of components: polyhydric alcohols, polyhydric carboxylic acids, and cyclic esters; etc.

Examples of polyhydric alcohols include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, trimethylene glycol, 1,4-tetramethylenediol, 1,3-tetramethylenediol, 2-methyl-1,3-trimethylenediol, 1,5-pentamethylenediol, neopentyl glycol, 1,6-hexamethylenediol, 3-methyl-1,5-pentamethylenediol, 2,4-diethyl-1,5-pentamethylenediol, glycerin, trimethylolpropane, trimethylolethane, cyclohexanediols (such as 1,4-cyclohexanediol), bisphenols (such as bisphenol A), and sugar alcohols (such as xylitol and sorbitol). These may be used alone or in combination of two or more.

Examples of the polycarboxylic acids include aliphatic dicarboxylic acids such as malonic acid, maleic acid, fumaric acid, succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, and dodecanedioic acid; alicyclic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid; and aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, orthophthalic acid, 2,6-naphthalenedicarboxylic acid, paraphenylenedicarboxylic acid, and trimellitic acid. These may be used alone or in combination of two or more.

Examples of cyclic esters include propiolactone, β-methyl-δ-valerolactone, and ε-caprolactone.

Examples of polycarbonate polyols include reaction products of polyhydric alcohols and phosgene, ring-opening polymerization products of cyclic carbonate esters (such as alkylene carbonates), etc. These may be used alone or in combination of two or more.

The polyhydric alcohol in the polycarbonate polyol may be a compound similar to the polyhydric alcohol in the polyester polyol. Examples of the alkylene carbonate include ethylene carbonate, trimethylene carbonate, tetramethylene carbonate, and hexamethylene carbonate. One of these may be used alone, or two or more may be used in combination.

The polycarbonate polyol is not particularly limited as long as it is a compound having a carbonate bond in the molecule and a hydroxyl group at the molecular terminal. The polycarbonate polyol may additionally have an ester bond in addition to the carbonate bond.

Examples of polyolefin polyols include those having a homopolymer or copolymer of ethylene, propylene, butene, etc. as a saturated hydrocarbon backbone and having a hydroxyl group at the molecular terminal.

As a polybutadiene-based polyol, there can be mentioned one having a copolymer of butadiene as a hydrocarbon skeleton and having a hydroxyl group at the molecular terminal. The polybutadiene-based polyol may be a hydrogenated polybutadiene polyol in which all or part of the ethylenically unsaturated groups contained in the structure are hydrogenated.

As polyisoprene-based polyols, there can be mentioned those having a copolymer of isoprene as a hydrocarbon skeleton and having a hydroxyl group at the molecular terminal. The polyisoprene-based polyol may be a hydrogenated polyisoprene polyol in which all or part of the ethylenically unsaturated groups contained in the structure are hydrogenated.

As (meth)acrylic polyols, examples thereof include polymers or copolymers of (meth)acrylic acid esters having at least two hydroxyl groups in the molecule. As such (meth)acrylic acid esters, examples thereof include hydroxyl group-containing (meth)acrylate compounds containing one ethylenically unsaturated group as described above. If necessary, other copolymerizable monomers may also be copolymerized.

Examples of the copolymerizable monomer include acrylic acid esters such as (meth)acrylic acid alkyl esters, such as methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, hexyl (meth)acrylate, octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, decyl (meth)acrylate, dodecyl (meth)acrylate, and octadecyl (meth)acrylate; styrene-based compounds such as styrene and methylstyrene;

In addition, it may be a hydroxyl group-containing (meth)acrylic polyol formed by reacting a carboxylic acid such as (meth)acrylic acid with a (meth)acrylic polymer having a glycidyl group in the side chain, or it may be a hydroxyl group-containing (meth)acrylic polyol formed by reacting a glycidyl group-containing compound with a (meth)acrylic polymer having a carboxylic acid in the side chain.

Among them, polyester polyols and polyether polyols are preferable, and in terms of flexibility of the cured product (adhesive) and compatibility with the photopolymerizable compound, polyether polyols are particularly preferable, and polytetramethylene glycol is most preferable. The polyol compound (a3) may be used alone, or two or more types may be used in combination.

The number average molecular weight of the polyol compound (D-a3) is preferably 200 to 3,000, more preferably 250 to 2,000, and even more preferably 300 to 1,000. If the number average molecular weight of the polyol compound (D-a3) is too small, the crosslinking density tends to increase excessively, resulting in poor adhesion to the substrate. If the number average molecular weight of the polyol compound (D-a3) is too large, the crystallinity tends to increase, resulting in high viscosity.

The number average molecular weight is the number average molecular weight converted to standard polystyrene molecular weight. For example, it can be measured using a high-performance liquid chromatograph (Nippon Waters Co., Ltd., "Waters 2695 (main unit)" and "Waters 2414 (detector)") with three columns: Shodex GPCKF-806L (exclusion limit molecular weight: 2×107, separation range: 100 to 2×107, theoretical plate number: 10,000 plates/piece, filler material: styrene-divinylbenzene copolymer, filler particle size: 10 μm) connected in series.

As the hydroxyl group-containing (meth)acrylate compound (D-a4) containing three or more (meth)acryloyl groups, examples thereof include pentaerythritol tri(meth)acrylate, caprolactone-modified pentaerythritol tri(meth)acrylate, ethylene oxide-modified pentaerythritol tri(meth)acrylate, dipentaerythritol penta(meth)acrylate, caprolactone-modified dipentaerythritol penta(meth)acrylate, and ethylene oxide-modified dipentaerythritol penta(meth)acrylate.

Among them, dipentaerythritol penta(meth)acrylate and pentaerythritol tri(meth)acrylate are preferable.

Examples of monoisocyanate compounds (D-a5) include monoisocyanates such as butane isocyanate, 3-chlorobenzene isocyanate, cyclohexane isocyanate, and 3-isopropenyl-α,α-dimethylbenzyl isocyanate.

Urethane (meth)acrylate (D-a-u) can be synthesized according to a known method. For example, the reaction product of a hydroxyl group-containing (meth)acrylate compound (D-a1) and a polyhydric isocyanate compound (D-a2) can be synthesized according to the method described in paragraphs [0036] to [0042] of Japanese Patent Application Laid-Open No. 2020-152786.

The weight average molecular weight of the urethane (meth)acrylate (D-a-u) that can be used in the present invention is preferably 1,000 to 60,000, more preferably 1,500 to 50,000, and even more preferably 1,800 to 30,000. When the weight average molecular weight is equal to or greater than the lower limit, the curing shrinkage of the cured product upon curing does not increase, and when it is equal to or less than the upper limit, the viscosity is maintained low, making handling easy.

The weight average molecular weight is the weight average molecular weight converted to standard polystyrene molecular weight, and can be measured using a high-performance liquid chromatograph (Nippon Waters Co., Ltd., "Waters 2695 (main unit)" and "Waters 2414 (detector)") with three columns, Shodex GPCKF-806L (exclusion limit molecular weight: 2×107, separation range: 100 to 2×107, theoretical plate number: 10,000 plates/piece, filler material: styrene-divinylbenzene copolymer, filler particle size: 10 μm), connected in series.

The viscosity of urethane (meth)acrylate (D-a-u) at 60°C is preferably 500 to 100,000 mPa·s, more preferably 800 to 50,000 mPa·s, and still more preferably 1,00 to 35,000 mPa·s. When the viscosity is within the above range, workability is good. In addition, the viscosity is a value measured by an E-type viscometer.

The curable resin composition (D') related to the present invention may contain, in addition to a trifunctional or higher (meth)acrylate (D-a), a (meth)acrylate-based compound. Examples of such (meth)acrylate-based compounds include monofunctional (meth)acrylates and derivatives thereof, difunctional (meth)acrylates and derivatives thereof, and the like.

The content of (meth)acrylate compounds other than the trifunctional or higher (meth)acrylate (D-a) is usually 20 parts by mass or less, preferably 10 parts by mass or less, per 100 parts by mass of the trifunctional or higher (meth)acrylate (D-a).

Monofunctional (meth)acrylates and derivatives thereof include, for example, methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, iso-propyl (meth)acrylate, n-butyl (meth)acrylate, iso-butyl (meth)acrylate, sec-butyl (meth)acrylate, n-hexyl (meth)acrylate, n-octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-decyl (meth)acrylate, lauryl (meth)acrylate, n-tridecyl (meth)acrylate, stearyl (meth)acrylate, benzyl (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, Alkoxypolyalkylene glycol (meth)acrylates such as tetrahydrofurfuryl (meth)acrylate, ethoxyethyl (meth)acrylate, ethylcarbitol (meth)acrylate, butoxyethyl (meth)acrylate, dimethylaminoethyl (meth)acrylate and its modified products by a cationizing agent, diethylaminoethyl (meth)acrylate and its modified products by a cationizing agent, cyanoethyl (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, and methoxypolypropylene glycol (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, Examples thereof include 2-hydroxy-3-phenoxypropyl (meth)acrylate, 2-(meth)acryloyloxyethyl-2-hydroxyethyl phthalate, (meth)acrylic acid, 2-(meth)acryloyloxyethyl phthalate, 2-(meth)acryloyloxyethyl hexahydrophthalate, 2-(meth)acryloylpropyl phthalate, (meth)acryloyloxyethyl succinate, and 2-isocyanateethyl (meth)acrylate.

As bifunctional (meth)acrylates and derivatives thereof, for example, bifunctional (meth)acrylates such as ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, butanediol di(meth)acrylate, hexanediol di(meth)acrylate, nonanediol di(meth)acrylate, ethoxylated di(meth)acrylate, propoxylated hexanediol di(meth)acrylate, triethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, and ethoxylated neopentyl glycol di(meth)acrylate, bifunctional urethane (meth)acrylates, Examples include bifunctional epoxy acrylate and bifunctional polyester acrylate.

(Quaternary ammonium base-containing polymer (D-b))

A quaternary ammonium base-containing polymer (D-b) is a polymer having one or more quaternary ammonium base groups (excluding trifunctional or higher (meth)acrylates (D-a)).

As the polymer having the main skeleton constituting the quaternary ammonium base-containing polymer (D-b), examples thereof include a quaternary ammonium base-containing acrylic polymer, a quaternary ammonium base-containing olefin polymer, a quaternary ammonium base-containing ester polymer, a quaternary ammonium base-containing cellulose polymer, a quaternary ammonium base-containing styrene polymer, copolymers thereof, and the like.

In the present invention, by containing a quaternary ammonium base-containing polymer (D-b), the antistatic property of the laminated film can be efficiently improved, and excellent wear resistance can also be achieved. Among these, a quaternary ammonium base-containing acrylic polymer is preferable because it has an excellent balance of segregation on the surface for expressing compatibility with (meth)acrylate and antistatic property, and can obtain a high level of antistatic performance. The quaternary ammonium base-containing polymer (D-b) may be used alone, or two or more types may be used in combination.

A quaternary ammonium base-containing polymer (D-b) can be obtained, for example, by copolymerization of a monomer having a quaternary ammonium base and an unsaturated group and a compound (e.g., a monomer, an oligomer) having another unsaturated group.

Examples of the monomer having a quaternary ammonium base and an unsaturated group include (meth)acryloyloxyethyltrimethylammonium chloride, 2-hydroxy-3-(meth)acryloxypropyltrimethylammonium chloride, 2-hydroxy-3-(meth)acryloxypropyltriethylammonium bromide, 2-hydroxy-3-(meth)acryloxypropyltributylammonium chloride, 2-hydroxy-3-(meth)acryloxypropylmethylethylbutylammonium chloride, 2-hydroxy-3-(meth)acryloxypropyldimethylphenylammonium chloride, and 2-hydroxy-3-(meth)acryloxypropyldimethylcyclohexylammonium chloride.

Examples of compounds having other unsaturated groups include (meth)acrylic acid alkyl esters such as cyclohexyl (meth)acrylate, methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, hexyl (meth)acrylate, octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, decyl (meth)acrylate, dodecyl (meth)acrylate, and octadecyl (meth)acrylate; 2-(meth)acryloyloxyethylsuccinic acid; 2-(meth)acryloyloxyethylhexahydrophthalic acid, and the like.

The number average molecular weight of the quaternary ammonium base-containing polymer (D-b) is obtained, for example, by a polystyrene standard using gel permeation chromatography (GPC). The number average molecular weight of the quaternary ammonium base-containing polymer (D-b) is usually in the range of 5,000 to 500,000, and preferably 7,000 to 300,000. When the number average molecular weight of the quaternary ammonium base-containing polymer (D-b) is equal to or greater than the lower limit of the above numerical range, no bleed occurs on the surface of the coating layer. On the other hand, when the number average weight molecular weight of the quaternary ammonium base-containing polymer (D-b) is equal to or less than the upper limit of the above numerical range, the compatibility in the present coating composition becomes good.

A quaternary ammonium base-containing polymer (D-b) can be produced, for example, by polymerizing a monomer component including a quaternary ammonium base and a monomer having an unsaturated group. The monomer component may additionally include a compound having another unsaturated group, a polymerization initiator, etc., as necessary.

(Compound having a fluorine atom-containing structure and a cyclic siloxane structure (D-c))

The curable resin composition (D') forming the cured resin layer (D) contains a compound having a fluorine atom-containing structure and a cyclic siloxane structure. Examples of the compound include a fluorine compound represented by the following general formula.

[Chemical formula 8]

In formula (1), R ¹ and R ² are each independently an organic group having 1 to 12 carbon atoms which may have a substituent; m is an integer from 3 to 10.

In equation (1), m is preferably an integer from 3 to 6 in terms of abrasion resistance or wear resistance, and 3 or 4 is particularly preferable.

Examples of the organic group for R ¹ and R ² include chain alkyl groups such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, a butyl group, an isobutyl group, a sec-butyl group, and a t-butyl group; an alkoxy group such as a methoxy group and an ethoxy group; a cyclic alkyl group such as a cyclohexyl group and a norbornanyl group; an alkenyl group such as a vinyl group, a 1-propenyl group, an allyl group, a butenyl group, and a 1,3-butadienyl group; an alkynyl group such as an ethynyl group, a propynyl group, and a butynyl group; a halogenated alkyl group such as a trifluoromethyl group; an alkyl group having a saturated heterocyclic group such as a 3-pyrrolidinopropyl group; an aryl group such as a phenyl group which may have an alkyl substituent; an aralkyl group such as a phenylmethyl group and a phenylethyl group; etc.

In addition, the organic group for R ¹ and R ² may have an oxygen atom between carbon atoms, or may have an amide bond between carbon atoms. In addition, the organic group for R ¹ and R ² may be a perfluoro organic group in which all hydrogen atoms bonded to the carbon atoms are replaced with fluorine atoms.

When imparting water repellency to the coating layer, at least a part of R ² and R ³ is preferably a perfluoroorganic group having an oxygen atom between carbon atoms, and a perfluoroalkylene group having an oxygen atom between carbon atoms is more preferable.

As the substituent that the organic group for R ¹ and R ² may have, examples thereof include a hydroxy group, a halogen atom (e.g., a fluorine atom, a chlorine atom, a bromine atom, an iodine atom), a (meth)acryloyl group, etc. Among them, a hydroxy group, a halogen atom, and a (meth)acryloyl group are preferable.

In the present invention, the compound (D-c) having a fluorine atom-containing structure and a cyclic siloxane structure is preferably a fluorine compound having a perfluoroether structure and a cyclic siloxane structure. In addition, it is preferably a compound having a perfluoroether structure at the terminal. That is, it is preferably a fluorine compound in which a perfluoroether skeleton is bonded to a cyclic siloxane skeleton in a single-terminal structure. By having the above structure, the sliding property of the cured resin layer surface can be further improved, and further, the water droplet contact angle of the cured resin layer surface can be increased. That is, since the water repellency is excellent, in addition to excellent stain resistance and practical abrasion resistance, excellent wear resistance can also be exhibited.

Compound (D-c) may be a reactive siloxane compound or a non-reactive siloxane compound.

Reactive siloxane compounds are compounds having a reactive functional group and a siloxane bond. Examples of the reactive functional group include an amino group, an epoxy group, a carboxyl group, a carbinol group, a (meth)acrylic group, a mercapto group, and a phenol group.

Non-reactive siloxane compounds are compounds that do not have reactive functional groups and have siloxane bonds. Examples thereof include polyether-modified siloxane compounds, methylstyryl-modified siloxane compounds, alkyl-modified siloxane compounds, higher fatty acid ester-modified siloxane compounds, hydrophilic special-modified siloxane compounds, higher alkoxy-modified siloxane compounds, and fluorine-modified siloxane compounds.

Examples of methods for synthesizing the compound (D-c) include a method in which an organic group containing three or more fluorine atoms and a siloxane compound having three or more Si-H groups undergoes an addition reaction with allyl (meth)acrylate or the like, and a method in which an organic group containing three or more fluorine atoms and a siloxane compound having three or more Si-H groups undergoes a dehydrogenation reaction with a (meth)acrylic compound having an OH group such as hydroxyethyl acrylate.

Among these methods, the addition reaction is preferable. Although the (meth)acrylic group may also undergo an addition reaction, in the dehydrogenation reaction, the reaction proceeds while maintaining the (meth)acrylic group by using a catalyst such as an amine, so that the target compound can be easily obtained.

(Composition of curable resin composition (D'))

The content of the trifunctional or higher (meth)acrylate (D-a) is preferably 50 to 99 parts by mass, more preferably 60 to 97 parts by mass, based on 100 parts by mass of the solid content of the curable resin composition (D'). When the content of the trifunctional or higher (meth)acrylate (D-a) is equal to or greater than the lower limit above, the abrasion resistance of the cured resin layer (D) becomes sufficient. On the other hand, when the content of the trifunctional or higher (meth)acrylate (D-a) is equal to or less than the upper limit above, a sufficient concentration of the quaternary ammonium base-containing polymer (D-b) is obtained, thereby obtaining good antistatic properties.

The content of the quaternary ammonium base-containing polymer (D-b) is preferably 0.5 to 30 parts by mass, more preferably 1 to 20 parts by mass, per 100 parts by mass of (meth)acrylate (D-a). When the content of the quaternary ammonium base-containing polymer (D-b) is equal to or greater than the lower limit above, an effect of improving antistatic properties by the quaternary ammonium base-containing polymer is obtained. On the other hand, when the content of the quaternary ammonium base-containing polymer (D-b) is equal to or less than the upper limit above, the transparency of the coating layer becomes good. In addition, when the content of the compound (D-c) is in a range equal to or greater than the lower limit above and equal to or less than the upper limit above, wear resistance can also be improved.

In the cured resin layer (D), that is, in the curable resin composition (D'), the content of the compound (D-c) is preferably 0.01 to 5 parts by mass, more preferably 0.05 to 3 parts by mass, and particularly preferably 0.1 to 1 part by mass, per 100 parts by mass of (meth)acrylate (D-a). When the content of the compound (D-c) is equal to or greater than the lower limit above, the effect of improving the antifouling properties by the compound (D-c) is sufficiently obtained. On the other hand, when the content of the compound (D-c) is equal to or less than the upper limit above, the transparency of the coating layer is maintained, and sufficient antistatic properties are exhibited. In addition, when the content of the compound (D-c) is in a range equal to or greater than the lower limit above and equal to or less than the upper limit above, wear resistance can also be improved.

(menstruum)

The curable resin composition (D') may be made into a coating liquid by being diluted with a solvent. The curable resin composition (D') may be made into a cured resin layer (D) by applying it as a liquid coating liquid on the cured resin layer (A), drying it, and further curing it. Each component constituting the curable resin composition (D') may be dissolved in a solvent, or may be dispersed in the solvent.

As a solvent, the same type and amount as those described for the curable resin composition (B') can be used. In addition, other components described in the first embodiment may be added to the curable resin composition (D'). In addition, regarding the photoinitiator, photopolymerization initiator, and photoacid generator, the type and content thereof can be the same as those for the curable resin composition (B') of the first embodiment.

Additionally, the viscosity of the curable resin compositions (A') and (D') is the same as that of the curable resin compositions (A') and (B') in the first embodiment.

(Viscosity of curable resin compositions (A') and (D'))

The curable resin compositions (A') and (D') for forming the cured resin layer (A) and the cured resin layer (D) preferably have a viscosity of 10 to 60 mPa·s at 25°C as measured by an E-type viscometer in order to improve coatability, and more preferably 30 mPa·s or less, more preferably 20 mPa·s or less, more preferably 15 mPa·s or less, and more preferably 12 mPa·s or less.

(Thickness of the cured resin layer (D))

The thickness of the cured resin layer (D) is preferably 10.0 µm or less, more preferably 8.0 µm or less, still more preferably 6.0 µm or less, and particularly preferably 5.0 µm or less.

When the thickness of the cured resin layer (D) is equal to or less than the upper limit, curling or thermal wrinkles can be prevented in a laminated body configuration having the cured resin layer (D) such as a laminated film, and thus good flatness can be secured.

Meanwhile, there is no particular limitation on the lower limit of the thickness of the cured resin layer (D), but it is preferable to be 1.0 ㎛ or more in order to appropriately protect the base film.

In addition, from the viewpoint of bendability, the total thickness of the cured resin layer (A) and the cured resin layer (D) is preferably 10.0 µm or less, more preferably 8.0 µm or less, particularly preferably 6.0 µm or less, and particularly preferably 5.0 µm or less.

It is preferable that the light transmittance of the surface of the cured resin layer (D) at a wavelength of 380 nm is 3.0% or less. If the light transmittance is 3.0% or less, it is advantageous in that the partner material to be bonded can be prevented from deteriorating due to ultraviolet rays. From the above viewpoint, the light transmittance at a wavelength of 380 nm is more preferably 2.8% or less.

In addition, it is preferable that the maximum reflectivity difference of the surface of the cured resin layer (D) at a wavelength of 500 to 600 nm is 1.5% or less. If the maximum reflectivity difference (the oscillation amplitude of the light transmittance) is 1.5% or less, it is advantageous in that interference patterns become difficult to see. From the above viewpoint, the maximum reflectivity difference is more preferably 1.0% or less, more preferably 0.5% or less, and particularly preferably 0.3% or less.

(Surface condition of each layer)

The surface of the cured resin layer (A) may be uneven or flat, but from the perspective of appearance (surface gloss), it is preferable that it be flat.

In addition, the surface of the cured resin layer (D) may be either uneven or flat, but from the viewpoint of appearance (surface gloss), it is preferable to be flat. On the other hand, from the viewpoint of imparting anti-glare properties, it is preferable to be uneven. Depending on the required characteristics, it can be arbitrarily selected.

<<Method for manufacturing laminated film>>

Both the curable resin layer (A) and the curable resin layer (D) (hereinafter, both may be collectively referred to simply as the “curable resin layer”) can be formed by curing a curable composition, i.e., a composition having a curable performance (curable resin composition). That is, the curable resin layer is formed by, for example, applying a curable resin composition having a mass average molecular weight in the range of 1,000 to 500,000 onto a base film and curing it.

More specifically, the present laminated film can be manufactured by applying a curable resin composition (A') to at least one surface of a substrate film and curing it to form a cured resin layer (A), and then applying a curable resin composition (D') thereon and curing it to form a cured resin layer (D). At this time, the cured resin layer (A) and the cured resin layer (D) may be cured simultaneously.

In addition, after forming the cured resin layer (A), the film may be first wound into a roll shape, the film may be unwound again, and a curable resin composition B may be applied onto the cured resin layer (A) and cured to form a cured resin layer (D). In addition, after forming the cured resin layer (A) on the surface of the base film, a curable resin composition (D') may be continuously applied and cured to form the cured resin layer (D). In addition, the method for producing a laminated film is not limited to these methods at all.

<Method for forming a cured resin layer>

Regarding the method for forming the cured resin layer, the same method as in the first embodiment can be used. Regarding the drying conditions and curing method, the same method as in the first embodiment can be used.

<<Properties of laminated films>>

(My SW)

In the present laminated film, the surface hardness of the film, specifically, the SW resistance of the surface of the cured resin layer (D), can be set to 1000 times or more. Specifically, when measured by the method described in the examples, the number of round trips at which there are no scratches visible to the naked eye and the change from the initial film haze is less than 1% can be set to 1000 times or more.

(repeated bending)

This laminated film has excellent repetitive bending properties (bending resistance). Specifically, when a test is performed with a minimum radius R=1.5 so that the cured resin layer side of the laminated film becomes the inner surface, and the number of repetitive bends until cracks occur in the cured resin layer on the inner surface is measured, if no cracks occur even after 200,000 or more bends, the repetitive bending properties (bending resistance) can be evaluated as good.

(water contact angle)

The water droplet contact angle on the cured resin layer side of the present laminated film is preferably 100° or more, more preferably 105° or more, and still more preferably 110° or more.

In addition, after the uppermost surface of the cured resin layer (D) is subjected to reciprocating friction 1,000 times at a speed of 50 mm/sec while applying a load of 1 kg in a 2 cm by 2 cm dimension using a friction tester (RT-300 manufactured by Daiei Kagaku Seiki Seisakusho Co., Ltd.) with #0000 steel wool (trade name: BONSTAR, manufactured by Nippon Steel Wool Co., Ltd.), the water contact angle is preferably 90° or higher, more preferably 95° or higher. The fact that the water contact angle after reciprocating friction is within the above range indicates that a predetermined water repellency or higher is maintained even after the reciprocating friction, and indicates that the steel wool resistance (SW resistance) of the cured resin layer is good.

In addition, an eraser (product number: ER-KM, circular diameter 6.7 mm, manufactured by Tombow Pencil Co., Ltd.) is mounted on a rubbing tester (manufactured by Ohirarika Industries, Ltd.) with the tip of the eraser extending 1 to 3 mm from the mounting portion so that the circular portion evenly contacts the uppermost surface of the cured resin layer (D), and after applying a load of 0.5 kg and performing 100 reciprocations at a speed of 1 reciprocation/sec over an area of 5 cm, the water droplet contact angle is preferably 90° or more, and more preferably 95° or more.

(Light transmittance)

When the present laminated film is intended for optical use, it is preferable that the total light transmittance be 85% or higher, more preferably 86% or higher, and particularly preferably 88% or higher. In addition, the total light transmittance was measured using a haze meter. Details of the measurement method are in accordance with the method described in the examples.

(film haze)

When the present laminated film is intended for optical use, it is preferable that the film haze be 1.0% or less, more preferably 0.8% or less, and particularly preferably 0.6% or less. In addition, the film haze was measured with a haze meter. Details of the measurement method are in accordance with the method described in the examples.

(interference pattern)

By setting the vibration range of the light transmittance of 500 to 600 nm to 1.5% or less, preferably 1.0% or less, more preferably 0.5% or less, a film in which interference patterns are difficult to be seen can be obtained.

(anti-warfare)

The surface resistivity of the surface of the cured resin layer (B) is not particularly limited, but is, for example, 1×10 ¹² Ω/□ or less, preferably 1×10 ¹¹ Ω/□ or less. There is no particular lower limit to the surface resistivity, but considering the cost of the antistatic agent, it is preferably 1×10 ⁴ Ω/□ or more. The lower the surface resistivity of the cured resin layer (B), the better the antistatic property, and for example, in a process of peeling a functional layer such as an adhesive layer provided on the cured resin layer (B), peeling electrification can be suppressed, thereby preventing adhesion of foreign substances, etc. The surface resistivity of the cured resin layer (B) can be made within the above range, for example, by containing an antistatic agent in the cured resin layer (B).

(Fluorine atomic concentration)

The ratio (F2/F1) of the fluorine atomic concentration (F2; Atomic%) at a point where Ar etching is performed for 10 seconds at an acceleration voltage of 200 eV to the fluorine atomic concentration (F1: Atomic%) of the uppermost surface of the laminated film (the surface on the cured resin layer (B) side) as measured by X-ray photoelectron spectroscopy (XPS) is preferably 0.2 or less, more preferably 0.0001 to 0.10, and particularly preferably 0.001 to 0.02.

If the above ratio (F2/F1) is small, it means that the fluorine atom occupancy rate of the fluorine compound having the (Y) cyclic siloxane skeleton on the surface of the laminated film is high, and by segregating the fluorine atoms on the surface of the laminated film and setting (F2/F1) within a specific range, a laminated film having excellent abrasion resistance or wear resistance can be obtained.

Details of the method for measuring the fluorine atom concentration of this laminated film are according to the method described in the examples.

<<Characteristics and Uses of Laminated Film>>

This laminated film has a high level of surface hardness (for example, SW resistance of more than 2000 round trips).

In addition, the present laminated film has excellent antistatic properties and antifouling properties, is unlikely to show interference patterns, and further has excellent wear resistance and satisfies practical repeated bending properties, so it can be used for purposes such as surface protection, display, and especially front panels. For example, it can be suitably used as a surface protection film, and especially as a surface protection film for displays. However, the uses of the present laminated film are not limited to these uses.

Example

Hereinafter, the present invention will be described in more detail using examples, comparative examples, and reference examples; however, the present invention is not limited to the following examples, comparative examples, and reference examples, unless it deviates from the spirit thereof.

Also, in the example, "bu" and "%" indicate mass standards.

<Evaluation method>

The measurement and evaluation methods used in the examples are as follows.

(1) Method for measuring film thickness of cured resin layer

Each laminated film was adhered onto a glass slide glass using Dong-A Synthetic's "Aron Alpha Series" to prepare a SAICS sample. The obtained SAICS sample was set on a CYCAS (DN-01 manufactured by Daipla Wintes Co., Ltd.), and a slit 300 µm wide and 1 µm deep was made in advance with a diamond blade. The slit was performed using a single-crystal diamond blade having a V-angle dimension of 80°, a rake angle of 5°, and a relief angle of 5°. For the measurement, a 300 µm wide borazone blade was set on the sample into which a 300 µm wide slit had been made in advance, and the film thickness of each cured resin layer was measured at an arbitrary depth, a horizontal speed of 1 µm/s, and a vertical speed of 0.5 µm/s. For the measurement, a boron nitride blade having a blade width dimension of 0.3 mm, a rake angle of 20°, and a relief angle of 10° was used. The thickness of each layer was calculated by measuring the material strength from the vertical displacement position and cutting force.

(2) Film Haze

In accordance with JIS K 7136:2000, the film haze of each laminated film was measured using a haze meter HM-150 manufactured by Murakami Color Technology Research Institute. The judgment criteria are as follows.

(Judging criteria)

○ : 1.0% or less

△ : Over 1.0% and less than 1.5%

× : 1.5% or more

(3) Retardation (Re) of the substrate film

To measure the retardation (Re) of the substrate film, a "Phase Difference Measuring Device (KOBRA-21ADH)" manufactured by Wangja Measurement Equipment Co., Ltd. was used. A 3.5 cm x 3.5 cm sample was cut out at 10 cm intervals in the film width direction from the center in the film width direction, and the sample was installed in the device so that the film width direction was at an angle defined by this measuring device of 0°, and the retardation (Re) in the true axis direction (width direction) at a wavelength of 590 nm at an incident angle of 0° was measured.

The difference between the maximum and minimum values of retardation obtained by each substrate film sample was calculated, and the difference was divided by the distance (m) in the direction of the true axis (in the width direction) of the position in the film sample (3.5 cm × 3.5 cm sample) where the maximum and minimum values were obtained, and the result was calculated as the “change in retardation (Re) in the direction of the true axis (in the width direction) (ΔRe).”

The change in retardation (Re) in the direction of the true axis (in the width direction) (㎚/m) = (maximum value of retardation - minimum value of retardation) / distance between the maximum value and the minimum value in the direction of the true axis (in the width direction) (m)

(4) Steel wool (SW resistance) test (abrasion resistance)

The uppermost surface (surface of the cured resin layer) of the laminated film was subjected to reciprocal friction at a speed of 50 mm/sec while applying a load of 1 kg in a 2 cm by 2 cm dimension using #0000 steel wool (trade name: BONSTAR, manufactured by Nippon Steel Wool Co., Ltd.) in a friction tester (RT-300 manufactured by Daiei Kagaku Seiki Seisakusho Co., Ltd.), and the presence or absence of scratches on the surface of the cured resin layer was visually confirmed. In addition, the haze value of the laminated film before and after the friction was measured. It was confirmed that there were no scratches on the surface of the cured resin layer that could be visually confirmed, and the rate of change in the film haze after 2000 reciprocations from the initial film haze (film haze before friction) was determined, and the judgment was made according to the following judgment criteria. In addition, the rate of change in haze was calculated by the following equation.

Change rate (%) = (film haze after wear - initial film haze) / initial film haze × 100

(Judging criteria)

A: The change rate is less than 1%.

B: Change rate is 1% or more.

(5) Bending durability

Using a bending tester (DLDMLH-FS, manufactured by Yuasa System Equipment Co., Ltd.), a test was performed with a minimum radius R=1.5 so that the cured resin layer side of the laminated film became the inner surface, and the presence or absence of cracks in the cured resin layer on the inner surface was visually confirmed. Then, the number of repeated bends until cracks occurred was measured, and the results were judged according to the following judgment criteria.

(Judging criteria)

A: Repeated bending count is more than 200,000 times

B: Repeated bending count is more than 100,000 times but less than 200,000 times

C: Repeated bending count is more than 1000 times and less than 100,000 times

D: Repeated bending count is less than 1000 times

(6) Elongation at break of cured resin layer

The laminated film was cut into a strip shape with a width of 10 mm and a length of 150 mm to produce a test piece. A tensile tester (201X type tester manufactured by Indesco) equipped with a constant temperature and humidity chamber was used, and the test piece was inserted into the chuck of the tensile tester so that the initial chuck-to-chuck distance was 50 mm. Then, the sample was pulled at a tensile speed of 5 m/min, and the displacement at which cracks occurred in the cured resin layer was visually confirmed, and the elongation was calculated.

Elongation (%) = (length at break - initial length) / initial length × 100

(7) Light transmittance

In accordance with JIS K 7136:2000, the total light transmittance of each laminated film was measured using a haze meter HM-150 manufactured by Murakami Color Technology Research Institute.

(8) Light transmittance

Using a spectrophotometer (U-3900H manufactured by Hitachi High-Technologies Co., Ltd.), the light transmittance of each laminated film at each measurement wavelength of 380 nm, 400 nm, and 500 to 600 nm was measured.

(9) Absolute reflectance

Black tape (3M, Scotch117) was attached to the side of the laminated film where the cured resin layer was not laminated, and the absolute reflectance at a wavelength of 550 nm of the side of the cured resin layer was measured using a spectrophotometer (Hitachi High-Technologies, U-3900H).

Absolute reflectance was calculated as the ratio of the amount of light reflected from the cured resin layer surface of the laminated film to the amount of light measured directly from the light source without using a reference plate.

Absolute Reflectance (%) = Amount of light reflected from the cured resin layer of the laminated film / Amount of light used × 100

(10) Interference pattern

In a film laminate in which a black tape (3M, Scotch117) was attached to the side on which the cured resin layer of the laminated film is not laminated, an interference pattern was visually confirmed from the side on which the cured resin layer is formed under a three-wavelength fluorescent lamp, and the result was evaluated according to the following criteria. In addition, the oscillation width of the light transmittance of 500 to 600 nm is the oscillation width of the reflectance in the reflection simulation of light with a wavelength of 500 to 600 nm.

(Judging criteria)

A: Almost no interference pattern (especially good)

(Less than 0.6% with a vibration amplitude of light transmittance of 500~600㎚)

B: Interference pattern is difficult to see (good)

(0.6% or more and less than 1.1% in vibration amplitude of light transmittance of 500~600㎚)

C: Interference pattern is visible (slightly bad)

(1.1% or more and 1.5% or less in vibration amplitude of light transmittance of 500~600㎚)

D: Interference pattern is clearly visible (bad)

(Exceeds 1.5% in vibration amplitude of light transmittance of 500~600㎚)

(11) Anti-static

Using a high-resistance resistivity meter: Hiresta UX MCP-HT800 and a measuring electrode: UR-100, all from Nitto Seiko Analytech Co., Ltd., the sample was humidified for 30 minutes in a measurement atmosphere of 23°C and 50% RH, and measurement was performed at an applied voltage of 500 V. The value after 1 minute was taken as the surface resistivity. If the resistance value exceeded the upper limit of the measurable range, it was considered as not measurable (over).

(12) Water contact angle (1)

Using an automatic contact angle meter (Data Physics, type OCA20), a drop of water was dropped on the uppermost surface (surface of the cured resin layer) of the laminated film, and the contact angle was measured after 60 seconds. Five measurements were taken, and the average value was used.

The measurements were performed before the steel wool test, after 1,000 reciprocating frictions, and after 2,000 reciprocating frictions using the method described in the steel wool test above.

(12) Water contact angle (2)

Using an automatic contact angle meter (Data Physics, type OCA20), a water droplet was dropped on the uppermost surface (surface of the cured resin layer) of the laminated film, and the contact angle was measured after 30 seconds. Measurements were made five times, and the average value was used.

The measurements were performed before the steel wool test, after 500 reciprocating frictions, after 1000 reciprocating frictions, and after the steel wool test using the method described in the steel wool test above.

(13) Fluorine atomic concentration

Measurements were made by X-ray photoelectron spectroscopy (XPS) using the following device.

Test device: XPS Thermo K-Alpha

Test conditions: X-ray monochromator Al Kα

: Analysis area 400㎛φ

: Extraction angle 90°

By performing a narrow scan on the detected elements through a wide scan, the ratio of fluorine among the ratios of the detected elements was obtained as the fluorine element concentration.

(14) Wear resistance

The uppermost surface (surface of the cured resin layer) of the laminated film was mounted on a rubbing tester (manufactured by Ohirarika Industries, Ltd.) with an eraser (model number: ER-KM, circular diameter 6.7 mm, manufactured by Tombow Pencil Co., Ltd.) with the tip of the eraser extending 1 to 3 mm from the mounting portion so that the circular portion was in even contact with the surface of the cured resin layer. While applying a load of 0.5 kg, the tester was made to reciprocate 100 times in an area of 5 cm at a speed of 1 reciprocation/sec, and the water contact angle on the surface of the cured resin layer was measured.

The water contact angle was measured by dropping 1.0 μL of a water droplet on the uppermost surface (surface of the cured resin layer) of the laminated film using a contact angle meter (model DMo-501, manufactured by Kyowa Interface Science Co., Ltd.), and measuring the contact angle after 60 seconds by the θ/2 method.

If the measured water contact angle was 90° or more, it was judged as ○ (good wear resistance).

The various materials used in the examples and comparative examples were prepared as follows.

The various materials used in the examples and comparative examples were prepared as follows.

<Polyester raw material>

(PET-A)

Solid-phase polymerized homopolyethylene terephthalate (using Ti polymerization catalyst)

(PET-B)

Homopolyethylene terephthalate (using Sb polymerization catalyst)

(PET-C)

Master batch containing 5 mass% of silica particles with an average particle size of 2.3 μm in homopolyethylene terephthalate (using Ti polymerization catalyst)

(PET-D)

Master batch containing 10 mass% of ultraviolet absorber (Sun Chemical Co., Ltd., Cyasorb 3638F) in homopolyethylene terephthalate (using Sb polymerization catalyst)

(PET-E)

Master batch containing 2 mass% of silica particles with an average particle size of 2.3 μm in homopolyethylene terephthalate (using Sb polymerization catalyst)

<Film>

(Material film PET1)

As a surface layer, a raw material was used in which PET-A was mixed at a ratio of 94 mass% and PET-C at a ratio of 6 mass%.

As an intermediate layer, a raw material was used in which PET-B was mixed at a ratio of 75 mass% and PET-D at a ratio of 25 mass%.

(Material film PET2)

As a surface layer, a raw material was used in which PET-B was mixed at a ratio of 90 mass% and PET-E at a ratio of 10 mass%.

As an intermediate layer, PET-B was used as a raw material at 100 mass%.

<Curable resin composition (A')>

(Curable resin composition (A'1))

The following compounds were mixed in a1:a2:b1:b2:c1:c2=55:17.5:5:15:2.5:5 (mass % of solid content).

((Binder Resin))

(a1) A water dispersion of a polyester resin copolymerized with the following composition

Monomer composition: (acid component) terephthalic acid/isophthalic acid/5-sodium sulfoisophthalic acid//(diol component) ethylene glycol/1,4-butanediol/diethylene glycol=56/40/4//70/20/10(㏖%)

(a2) A water dispersion of a polyester resin having a condensed polycyclic aromatic group, copolymerized with the following composition.

Monomer composition: (acid component) 2,6-naphthalenedicarboxylic acid/5-sodium sulfoisophthalic acid//(diol component) ethylene glycol/diethylene glycol = 92/8//80/20 (㏖%)

((Bridge))

(b1) Polyglycerol polyglycidyl ether, an epoxy compound

(b2) Oxazoline group-containing acrylic polymer (Nippon Shokubai Co., Ltd. "Epocross" (registered trademark)) Oxazoline group content 7.7mmol/g

((particle))

(c1) Silica particles with an average particle size of 70 nm

(c2) Zirconia sol with an average particle size of 20 nm

(Curable resin composition (A'2))

The following compounds were mixed in a ratio of a2:a3:b1:b2:b3=60:10:10:10:10 (mass % of solid content).

((Binder Resin))

(a2) A water dispersion of a polyester resin having a condensed polycyclic structure, copolymerized with the following composition:

Monomer composition: (acid component) 2,6-naphthalenedicarboxylic acid/5-sodium sulfoisophthalic acid//(diol component) ethylene glycol/diethylene glycol = 92/8//80/20 (㏖%)

(a3) Acrylic resin water dispersion polymerized with the following composition

Ethyl acrylate/n-butylacrylate/methyl methacrylate/N-methylolacrylamide/acrylic acid = 65/21/10/2/2 (mass %) emulsifying polymer (emulsifier: anionic surfactant)

((Bridge))

(b3) Hexamethoxymethylolated melamine

(b4) Water-soluble polyglycerol polyglycidyl ether

(b5) Oxazoline group-containing acrylic polymer (Nippon Shokubai Co., Ltd. "Epocross" (registered trademark)) Oxazoline group content 4.5 mmol/g

<Curable resin composition (B')>

(Curable resin composition (B'1))

To 100 parts by mass of a urethane acrylate (Mitsubishi Chemical Corporation's Shiko "UV1700B"), 0.5 parts by mass of a fluorine compound having a cyclic siloxane skeleton and a perfluoroether structure (KY1203, manufactured by Shin-Etsu Chemical) and 5 parts by mass of a photopolymerization initiator (Omnirad 127, manufactured by IGM Resins B.V.) were added a curable resin composition (B'1). The mass average molecular weight of the urethane acrylate of the curable resin composition (B'1) was 2,000, and the refractive index of the cured resin layer (B1), which was a cured product of the curable resin composition (B'1) prepared above, was 1.53.

(Curable resin composition (B'2))

To 100 parts by mass of urethane acrylate (Mitsubishi Chemical Corporation's Shiko "UV1700B"), 0.5 parts by mass of a compound having a urethane acrylate skeleton (RS-90 manufactured by DIC) and 5 parts by mass of a photopolymerization initiator (Omnirad 127 manufactured by IGM Resins B.V.) were added a curable resin composition (B'2). The mass average molecular weight of the urethane acrylate of the curable resin composition (B'2) was 2,000, and the refractive index of the cured resin layer (B2), which was a cured product of the curable resin composition (B'2) prepared above, was 1.53.

(Curable resin composition (B'3))

To 100 parts by mass of urethane acrylate (Mitsubishi Chemical Corporation's Shiko "UV1700B"), 0.5 parts by mass of a fluorine compound containing a long-chain siloxane skeleton (RS-58 manufactured by DIC) and 5 parts by mass of a photopolymerization initiator (Omnirad 127 manufactured by IGM Resins B.V.) were added a curable resin composition (B'3). The mass average molecular weight of the urethane acrylate of the curable resin composition (B'3) was 2,000, and the refractive index of the cured resin layer (B3), which was a cured product of the curable resin composition (B'3) prepared above, was 1.53.

(Curable resin composition (B'4))

To 60 parts by mass of urethane acrylate (Mitsubishi Chemical Corporation, Shiko "UV-1700B"), 40 parts by mass of fine alumina particles (surface-modifying nanoparticles, CIK Nanotechnical Corporation, ALMIBK-M114, average particle size: 13 nm), 5 parts by mass of a photopolymerization initiator (IGM Resins B.V., Omnirad 127), and 0.5 parts by mass of a leveling agent (DIC Corporation, Megapack "RS-90") were added, to prepare a curable resin composition (B'4). The mass average molecular weight of the urethane acrylate of the curable resin composition (B'4) was 2,000, and the refractive index of the cured resin layer (B4), which was a cured product of the curable resin composition (B'4) prepared above, was 1.56.

[Example 1]

The raw materials for the surface layer and the middle layer of the PET1 film described above were each fed into separate melt extruders, co-extruded at each extrusion temperature of 280°C, and cooled and solidified on a casting drum cooled to 25°C, thereby obtaining a non-oriented sheet (unstretched sheet) of two types and three layers (discharge amount (mass ratio) of surface layer/middle layer/surface layer = 3/59/3).

Next, the film was stretched 3.3 times in the machine direction (longitudinal direction) at 80°C using a roll stretcher, and the above-described curable resin composition (A'1) was applied so that the coating thickness (after drying) became 0.04 g/m2, and further stretched 3.5 times in the width direction at 110°C in a tenter. Finally, heat treatment was performed at 200°C to relax 5% in the transverse direction. In this way, a laminated polyester film (base film PET1/cured resin layer (A1)) having a cured resin layer (A1) and a thickness of 65 μm (each surface layer: 3 μm, middle layer: 59 μm) was obtained.

In order to cover the cured resin layer (A1) of the above-described laminated film, the curable resin composition (B'1) prepared as described above was applied with a bar coater so that the coating thickness (after drying) was 5 µm. After drying by heating at 90° C. for 1 minute, ultraviolet irradiation at an accumulated light dose of 400 mJ/cm2 was performed under a nitrogen atmosphere to cure the curable resin composition (B'1), thereby obtaining a laminated film having a laminated configuration of base film PET1/cured resin layer (A1)/cured resin layer (B1).

[Comparative Example 1]

In Example 1, except that the curable resin composition (B'1) was changed to the curable resin composition (B'2) prepared as described above, a laminated film comprising a laminated configuration of base film PET1/curable resin layer (A1)/curable resin layer (B2) was obtained in the same manner as in Example 1.

[Comparative Example 2]

In Example 1, except that the curable resin composition (B'1) was changed to a curable resin composition (B'3), a laminated film comprising a laminated configuration of base film PET1/curable resin layer (A1)/curable resin layer (B3) was obtained in the same manner as in Example 1.

[Comparative Example 3]

In Example 1, the base film PET1 was changed to the following base film PET2, and the laminated polyester film in Example 1 was changed to the following laminated polyester film, and a laminated film having a laminated configuration of base film PET2/cured resin layer (A2)/cured resin layer (B1) was obtained, by manufacturing in the same manner as in Example 1.

<Material film PET2>

The raw materials for the surface layer and the middle layer of the PET1 film were each fed into separate melt extruders, co-extruded at each extrusion temperature of 285°C, and cooled and solidified on a casting drum cooled to 40°C, thereby obtaining a non-oriented sheet (unstretched sheet) of two types and three layers (discharge amount (mass ratio) of surface layer/middle layer/surface layer = 1/8/1).

Next, the film was stretched 3.4 times in the machine direction (longitudinal direction) at 85°C using a roll stretcher, and the above-described curable resin composition (A'2) was applied so that the coating thickness (after drying) became 0.1 g/m2, and further stretched 4.3 times in the width direction at 110°C in a tenter. Finally, heat treatment was performed at 235°C to relax 2% in the transverse direction. In this way, a laminated polyester film (base film PET2/cured resin layer (A2)) having a cured resin layer (A2) and a thickness of 50 μm (each surface layer: 5 μm, middle layer: 40 μm) was obtained.

[Comparative Example 4]

In Example 1, except that the curable resin composition (B'1) was changed to a curable resin composition (B'4), a laminated film having a laminated configuration of base film PET1/curable resin layer (A1)/curable resin layer (B4) was obtained in the same manner as in Example 1.

<Evaluation Results>

The characteristics of each laminated film obtained in the above examples and comparative examples are shown in Table 1 below.

<Consideration>

From the results of the above examples and comparative examples, it can be seen that since the substrate film has a configuration in which a cured resin layer (A) and a cured resin layer (B) are sequentially laminated on the surface, and the cured resin layer (A) is a cured product of a curable resin composition (A') containing (A-a) a compound having a condensed polycyclic aromatic structure as a binder, (A-b) a crosslinking agent, and (A-c) particles, and the cured resin layer (B) is a cured product of a curable resin composition (B') containing (X) a urethane acrylate and (Y) a compound having a cyclic siloxane skeleton, it is possible to achieve both flexibility and a high level of abrasion resistance (for example, in terms of SW resistance, a reciprocating number of times at which a change from the initial film haze is less than 1%, i.e., 2,000 or more) and repeated bending properties (under the condition of R = 1.5, it can be bent 200,000 times), and also has a high contact angle and excellent low interference properties.

In contrast, it can be seen that it is difficult to achieve both the desired abrasion resistance and repeated bending property simply by providing a cured resin layer that does not include a compound having (X) urethane acrylate and (Y) a cyclic siloxane skeleton, as in Comparative Examples 1, 2, and 4. In addition, it can be seen from Comparative Example 4 that the desired abrasion resistance is not obtained even if particles are included in the curable resin composition (B').

In addition, it can be seen that Comparative Example 3, which does not include particles in the curable resin composition (A'), does not have sufficient low interference properties.

It is presumed that the reason for such difference is due to the composition of the cured resin layer (A) and the cured resin layer (B). Due to the composition of the cured resin layer (A), the interference of light with the base film is mainly reduced, making it difficult to see the interference pattern. In addition, by adopting the composition of the cured resin layer (B) whose refractive index is adjusted in advance so as to be difficult to affect the interference of light (in the present embodiment, the target refractive index is 1.53), it is possible to achieve both the desired abrasion resistance and the repeated bending property.

In the past, in laminated films having a surface layer with high SW resistance, when designing the target SW resistance to a desired level (e.g., 2000 times or more), the structural design of the raw materials constituting the base film being used was reexamined, as necessary, to further increase the tensile modulus.

In this regard, if the cured resin layer (A) or the cured resin layer (B) has a specific composition, it is possible to appropriately select a general-purpose base film distributed on the market, and thus an advantage of increased freedom in selecting the base film is obtained.

<Curable resin composition (C'1)>

The following compounds (CⅠ) to (CⅤ) were mixed to prepare a curable resin composition C1. The mixing ratio of (CⅠ), (CⅡ), (CⅢ), (CⅣ), and (CⅤ) was 7:69:12:10:2.

(Compound (C-a))

(CI): A conductive agent composed of polyethylenedioxythiophene and polystyrene sulfonic acid (Orgacon ICP 1010 manufactured by Agphagebat) neutralized with concentrated ammonia water to pH=9, nonvolatile component; 1.2 mass%, solvent; water

(CⅡ) Polyester resin water dispersion copolymerized with the following composition

Monomer composition: (acid component) 2,6-naphthalenedicarboxylic acid/5-sodium sulfoisophthalic acid = 92/8 (molar ratio) // (diol component) ethylene glycol/diethylene glycol = 80/20 (molar ratio)

(Compound (C-c))

(AⅢ): Polyglycerin with an average of n=4 in the following equation (3)

[Chemical formula 9]

(CⅣ): A nonionic surfactant having a structure of polyethylene oxide in the side chain, in which the average of m+n is 10 in the following formula (5)

[Chemical Formula 10]

(CⅤ): A fluorine-based nonionic surfactant having a hydrophobic group with a branched perfluoroalkenyl group and a hydrophilic group with a polyethylene oxide chain (average chain length of 8 units).

<Curable resin composition (A'1)>

The following compounds were mixed in a1:a2:b1:b2:c1:c2=55:17.5:5:15:2.5:5 (mass % of solid content).

((A-a) Binder)

(a1) A water dispersion of a polyester resin copolymerized with the following composition:

Monomer composition: (acid component) terephthalic acid/isophthalic acid/5-sodium sulfoisophthalic acid//(diol component) ethylene glycol/1,4-butanediol/diethylene glycol=56/40/4//70/20/10(㏖%)

(a2) A water dispersion of a polyester resin having a condensed polycyclic aromatic copolymerized with the following composition

Monomer composition: (acid component) 2,6-naphthalenedicarboxylic acid/5-sodium sulfoisophthalic acid//(diol component) ethylene glycol/diethylene glycol = 92/8//80/20 (㏖%)

((A-b) crosslinker)

(b1) Polyglycerol polyglycidyl ether, an epoxy compound

(b2) Oxazoline group-containing acrylic polymer (Nippon Shokubai Co., Ltd. "Epocross" (registered trademark)) Oxazoline group content 7.7mmоl/g

((A-c) particle)

(c1) Silica particles with an average particle size of 70 nm

(c2) Zirconia sol with an average particle size of 20 nm

<Curable resin composition (A'3)>

27.5 parts by mass of acrylic binder (ELAC medium: manufactured by Toyo Ink Co., Ltd.), 2.5 parts by mass of isocyanate hardener (Z202S: manufactured by Toyo Ink Co., Ltd.), 70 parts by mass of zirconium particles (ZP153: manufactured by Nippon Shokubai Co., Ltd.)

<Curable resin composition (B'5)>

(Synthesis of fluorine compounds)

69.4 parts by mass (0.1 mol) of a compound represented by the following formula (6), 36.5 parts by mass (0.315 mol) of 2-hydroxyethyl acrylate, and 111.9 parts by mass of toluene were mixed in a reactor, and after becoming uniform, 1.12 parts by mass (0.0126 mol) of N,N-diethylhydroxylamine as a catalyst was added. Thereafter, the reaction was performed at 70°C for 8 hours. After washing with water, toluene and the like were distilled off, and a compound (7) having the following fluorine atom-containing structure and cyclic siloxane structure was obtained.

[Chemical Formula 11]

[Chemical Formula 12]

To 80 parts by mass of (X) urethane (meth)acrylate (Mitsubishi Chemical Corporation's CIKO "UV1700B"), 0.5 parts by mass of a fluorine compound (7) having the above-described cyclic siloxane skeleton and perfluoroether structure, 20 parts by mass of fine alumina particles (surface-modified nanoparticles, ALMIBK-M115 manufactured by CIK Nanotechnical Co., Ltd., average particle size: 13 nm), and 5 parts by mass of a photopolymerization initiator (Omnirad 127 manufactured by IGM Resins B.V.) were added, to prepare a curable resin composition (B'5). The mass average molecular weight of the curable resin composition (B'5) was 2,000, and the refractive index of the cured resin layer (B5) was 1.53.

[Example 2]

The raw materials for the surface layer and the middle layer of the PET1 film described above were each fed into separate melt extruders, co-extruded at each extrusion temperature of 280°C, and cooled and solidified on a casting drum cooled to 25°C, thereby obtaining a non-oriented sheet (unstretched sheet) of two types and three layers (discharge amount (mass ratio) of surface layer/middle layer/surface layer = 3/59/3).

Next, the film was stretched 3.3 times in the machine direction (longitudinal direction) at 80°C using a roll stretcher, and the above-described curable resin composition (C'1) was applied so that the coating thickness (after drying) became 0.03 g/m2, and further stretched 3.5 times in the width direction at 110°C in a tenter. Finally, heat treatment was performed at 200°C to relax 5% in the transverse direction. In this way, a laminated polyester film (PET1/cured resin layer (C1)) having a cured resin layer (C) having a thickness of 65 μm (each surface layer: 3 μm, middle layer: 59 μm) was obtained.

In order to cover the cured resin layer (C1) of the above-described substrate film PET1, the following curable resin composition (A'3) was applied with a bar coater so that the coating thickness (after drying) would be 0.06 µm. It was dried by heating at 100°C for 30 seconds, thereby obtaining a cured resin layer (A'3) (before curing). Next, the above-described curable resin composition (B'5) was applied with a bar coater so that the coating thickness (after drying) would be 2.5 µm on the cured resin layer (A'3). It was dried by heating at 90°C for 1 minute, thereby obtaining a cured resin layer (B'5) (before curing). By irradiating the substrate with 400 mJ/cm2 of ultraviolet light in a nitrogen atmosphere, the cured resin layer (A'3) (before curing) and the cured resin layer (B'5) (before curing) were cured, thereby obtaining a laminated film having a laminated configuration of base film PET1/cured resin layer (C1)/cured resin layer (A3)/cured resin layer (B5).

The results evaluated using the above method are shown in Table 2.

[Comparative Example 5]

A laminated film was obtained by manufacturing in the same manner as in Example 2, except that the cured resin layer (A) was not provided. The results of evaluation in the same manner as in Example 1 are shown in Table 2.

[Comparative Example 6]

In Example 1, except that the cured resin layer (C) was not provided, a laminated film was obtained by manufacturing according to Example 1. That is, the raw materials for the surface layer and the middle layer of the base film PET2 were each fed into separate melting extruders, and each was melted at an extrusion temperature of 285°C, and then cooled and solidified on a casting drum cooled to 40°C, thereby coextruding in 2-type 3-layers (output amount (mass ratio) of surface layer/middle layer/surface layer = 1/8/1) to obtain an unoriented sheet (unstretched sheet).

Next, the film was stretched 3.4 times in the machine direction (longitudinal direction) at 85°C using a roll stretcher, and the above-described curable resin composition (A'1) was applied so that the coating thickness (after drying) became 0.1 g/m2, and then further stretched 4.3 times in the width direction at 110°C in a tenter, and then heat-treated at 235°C to relax 2% in the transverse direction. In this way, a laminated polyester film (PET2/cured resin layer (A1)) having a cured resin layer (A) having a thickness of 50 μm (each surface layer: 5 μm, middle layer: 40 μm) was obtained.

In order to cover the cured resin layer (A1) of the above-described laminated film, the curable resin composition (B'5) prepared as described above was applied with a bar coater so that the coating thickness (after drying) was 5 µm. After drying by heating at 90° C. for 1 minute, ultraviolet irradiation at an accumulated light dose of 400 mJ/cm2 was performed under a nitrogen atmosphere to cure the curable resin composition (B'5), thereby obtaining a laminated film having a laminated configuration of base film PET2/cured resin layer (A1)/cured resin layer (B5).

The results of the evaluation, similar to Example 1, are shown in Table 2.

<Consideration>

From the results of the above examples and comparative examples, it was found that the substrate film has a configuration in which a cured resin layer (C), a cured resin layer (A), and a cured resin layer (B) are sequentially laminated on the surface, and the cured resin layer (B) contains (X) a urethane acrylate and (Y) a fluorine compound having a cyclic siloxane skeleton and a perfluoroether structure, thereby achieving both flexibility and a high level of surface hardness (for example, in terms of SW resistance, a reciprocating number of times at which a change from the initial film haze is less than 1%, 2,000 or more) and repeated bending properties (under the condition of R = 1.5, it can be bent 200,000 times).

In contrast, as shown in Comparative Example 5, it was found that it was difficult to achieve both the desired hard coatability, repeatable bendability, and low-interference properties in a layer configuration without a cured resin layer (A) by only providing a cured resin layer (B), or in a layer configuration without a cured resin layer (C) as shown in Comparative Example 2. It is presumed that the cause of this difference is due to the difference in the composition of the cured resin layer (A) and the cured resin layer (B). In addition, since the optical interference with the cured resin layer (B) is reduced depending on the composition of the cured resin layer (A), it becomes difficult to see the interference pattern. On the other hand, by adopting the composition of the cured resin layer (B), it becomes possible to achieve both the desired abrasion resistance and repeatable bendability.

In addition, it was found that by setting the composition materials and thickness ratio of the cured resin layer (B) within a specific range, there is no need to make the tensile elastic modulus of the base film used extremely large, and thus there is no need to use a customized base film.

In the past, when designing a laminated film having a surface layer with high SW resistance to a desired level of SW resistance (e.g., 2000 times or more), it was necessary to review the structural design of the raw materials constituting the base film used to further increase the tensile modulus.

In contrast, if the cured resin layer (B) has a specific configuration, it is possible to appropriately select a general-purpose base film distributed on the market, and thus an advantage of increased freedom in selecting the base film is obtained.

<Curable resin composition>

(Curable resin composition (A'1))

The following compounds were mixed in a1:a2:b1:b2:c1:c2=55:17.5:5:15:2.5:5 (mass % of solid content).

((A-a) binder resin)

(a1) A water dispersion of a polyester resin copolymerized with the following composition

Monomer composition: (acid component) terephthalic acid/isophthalic acid/5-sodium sulfoisophthalic acid//(diol component) ethylene glycol/1,4-butanediol/diethylene glycol=56/40/4//70/20/10(㏖%)

(a2) A water dispersion of a polyester resin having a condensed polycyclic aromatic copolymerized with the following composition

Monomer composition: (acid component) 2,6-naphthalenedicarboxylic acid/5-sodium sulfoisophthalic acid//(diol component) ethylene glycol/diethylene glycol = 92/8//80/20 (㏖%)

((A-b) crosslinker)

(b1) Polyglycerol polyglycidyl ether, an epoxy compound

(b2) Oxazoline group-containing acrylic polymer (Nippon Shokubai Co., Ltd. "Epocross" (registered trademark)) Oxazoline group content 7.7mmol/g

((A-c) particle)

(c1) Silica particles with an average particle size of 70 nm

(c2) Zirconia sol with an average particle size of 20 nm

[Example 3]

In order to cover the cured resin layer (A) of the above-described base film PET1, a curable resin composition (D'1) prepared as follows was applied with a bar coater so that the coating thickness (after drying) became 5 µm. After drying by heating at 90° C. for 1 minute, ultraviolet irradiation at an accumulated light dose of 400 mJ/cm2 was performed in a nitrogen atmosphere to obtain a cured resin layer (D'1) (before curing). The cured resin layer (D'1) (before curing) was cured to obtain a laminated film having a laminated configuration of base film PET1/cured resin layer (A1)/cured resin layer (D1).

In addition, the fluorine atom concentration ratio (F2/F1) of the uppermost surface of the laminated film (the surface on the cured resin layer (D) side) measured by X-ray photoelectron spectroscopy (XPS) was 0.013.

(Curable resin composition (D'1))

As a (D-a) component, 80 parts by mass of urethane acrylate (Mitsubishi Chemical Corporation's Shiko "UV1700B") and 20 parts by mass of urethane acrylate (Mitsubishi Chemical Corporation's Shiko "UV7610B"), 5 parts by mass of the (D-b1) component described below, 0.2 parts by mass of a fluorine compound (D-c1) having a fluorine atom-containing structure and a cyclic siloxane structure, and 5 parts by mass of a photopolymerization initiator (IGM Resins B.V.'s Omnirad 127) were added to prepare a curable resin composition (D'1).

((D-b1) component)

B-b1: A polymer solution (D-b1) containing a quaternary ammonium base synthesized as follows was used. The synthesis method is as follows.

First, 83.2 parts of polycaprolactone monool (weight average molecular weight 2,000), 16.7 parts of m-isopropenyl-α,α'-dimethylbenzyl isocyanate, and 0.03 part of dioctyltin laurate were charged into a four-necked flask equipped with a thermometer, a stirrer, a water-cooled condenser, and a nitrogen gas inlet, and the mixture was reacted at 80°C. The reaction was terminated when the residual isocyanate group became 0.03% or less, thereby obtaining a polyester macromonomer (b-1m).

In a four-necked flask equipped with a thermometer, a stirrer, a water-cooled condenser, and a nitrogen gas inlet, 10 parts of polyester macromonomer (b-1m), 15 parts of methacryloyloxyethyl trimethyl ammonium chloride, 5 parts of cyclohexyl methacrylate, 0.2 part of azobisisobutyronitrile, 20 parts of methyl ethyl ketone, and 50 parts of isopropyl alcohol were charged, and polymerization was performed at 70°C for 8 hours under a nitrogen stream to obtain a solution of a quaternary ammonium base-containing polymer (D-b1).

((D-c1) Synthesis of fluorine compounds)

69.4 parts by mass (0.1 mol) of a compound represented by the following formula (2), 36.5 parts by mass (0.315 mol) of 2-hydroxyethyl acrylate, and 111.9 parts by mass of toluene were mixed in a reactor, and after becoming uniform, 1.12 parts by mass (0.0126 mol) of N,N-diethylhydroxylamine as a catalyst was added. Thereafter, the reaction was performed at 70°C for 8 hours. After washing with water, toluene and the like were distilled off, and compound (3) having the following fluorine atom-containing structure and cyclic siloxane structure was obtained.

[Chemical Formula 13]

[Chemical Formula 14]

[Example 4]

A laminated film having a laminated configuration of base film PET1/cured resin layer (A1)/cured resin layer (D1) was obtained by manufacturing in the same manner as in Example 1 except that the thickness of the cured resin layer (D) was changed.

[Example 5]

Except for changing the amount of the compound (D-c1) having a fluorine atom-containing structure and a cyclic siloxane structure, a laminated film was produced in the same manner as in Example 4, thereby obtaining a laminated film having a laminated configuration of base film PET1/cured resin layer (A1)/cured resin layer (D2).

That is, a laminated film was obtained in the same manner as in Example 4, except that a curable resin composition (D'2) similar to (D'1) was used, except that 0.5 mass part of a fluorine compound (D-c1) having a fluorine atom-containing structure and a cyclic siloxane structure was used instead of the curable resin composition (D'1).

[Comparative Example 7]

In Example 3, a curable resin composition (D'3) similar to (D'1) was used instead of the curable resin composition (D'1) except that it did not contain the component (D-b) (quaternary ammonium salt-containing polymer), and a laminated film was obtained by manufacturing in the same manner as in Example 3.

[Comparative Example 8]

In Example 3, a curable resin composition (D'4) similar to (D'1) was used instead of the curable resin composition (D'1) except that it did not contain a fluorine compound (D-c1) having a cyclic siloxane skeleton and a perfluoroether structure, and a laminated film was obtained by manufacturing in the same manner as in Example 3.

<Evaluation Results>

The characteristics of each laminated film obtained in the above examples and comparative examples are shown in Table 3 below.

For the laminated films obtained in Examples 4 and 5 and Comparative Examples 9 to 11 below, wear resistance was additionally evaluated. The results are shown in Table 4 below.

[Comparative Example 9]

In Example 4, a curable resin composition (D'3) similar to (D'1) was used instead of the curable resin composition (D'1) except that it did not contain the (D-b1) component (quaternary ammonium salt-containing polymer), and a laminated film was obtained by manufacturing in the same manner as in Example 2.

[Comparative Example 10]

In Example 5, a curable resin composition (D'5) similar to (D'2) was used instead of the curable resin composition (D'2) except that it did not contain the component (D-b1) (quaternary ammonium salt-containing polymer), and a laminated film was obtained by manufacturing in the same manner as in Example 2.

[Comparative Example 11]

In Example 4, a curable resin composition (D'4) similar to (D'1) was used instead of the curable resin composition (D'1) except that it did not contain a fluorine compound (D-c1) having a cyclic siloxane skeleton and a perfluoroether structure, and a laminated film was obtained by producing the composition in the same manner as in Example 2.

<Consideration>

From the results of the above examples and comparative examples, it was found that a high level of antistatic and antifouling properties can be achieved by having a structure in which a cured resin layer (A) and a cured resin layer (D) are sequentially laminated on at least one surface of a base film, and the cured resin layer (D) contains a trifunctional or higher (meth)acrylate (D-a), a quaternary ammonium base-containing polymer (D-b), and a compound (D-c) having a fluorine atom-containing structure and a cyclic siloxane structure. In addition, it was found that interference fringes are difficult to be seen, and practical repeated bending characteristics and abrasion resistance are also satisfied.

In addition, with regard to water repellency, it is evaluated that the change in the water contact angle before and after treatment by SW is small.

In contrast, it was found that it was difficult to achieve both the desired antistatic and antifouling properties with only one component, as in Comparative Examples 7 and 8, and the wear resistance was also unsatisfactory.

It is presumed that the reason for this difference is the difference in the composition of the cured resin layer (D). In addition, the composition of the cured resin layer (A) reduces the optical interference with the cured resin layer (D), making it difficult to see the interference pattern. In addition, it was found that the laminated film of Comparative Example 8 also had poor SW resistance.

Additionally, from Examples 9 to 11, it can be seen that the laminated film having a cured resin layer (A) and a cured resin layer (D) satisfying the composition specified in the present invention also has excellent wear resistance.

The laminated film of the present invention has excellent abrasion resistance (for example, 2,000 times or more in SW resistance evaluation) and repeated bending resistance (bending resistance, can be bent 200,000 times under the condition of R=1.5) at a high level, and can be applied as a film for protecting various surfaces. Among them, it can be suitably used for optical purposes such as display components (surface protection films, etc.) that require flexibility.

In addition, the laminated film of the present invention has excellent abrasion resistance (for example, 2,000 times or more in SW resistance evaluation) and repeated bending resistance (bending resistance, can be bent 200,000 times under the condition of R=1.5) at a high level, and at the same time, has excellent antistatic properties and can be used for various surface protection purposes. Among them, it can be suitably used for optical purposes such as display components (surface protection films, etc.) that require flexibility.

In addition, the laminated film of the present invention is capable of achieving both antistatic and antifouling properties at a high level, and is also excellent in wear resistance, so it can be used for various surface protection purposes. Among them, it can be particularly suited for optical purposes such as display components (surface protection films, etc.).

2 Base film
4. Cured resin layer (A)
6. Cured resin layer (B)
10 laminated film

Claims (26)

At least one side of the substrate film has a configuration in which a cured resin layer (A) and a cured resin layer (B) are sequentially laminated,
The above cured resin layer (A) is a cured product of a curable resin composition (A') containing a binder (Aa),
A laminated film, wherein the above-mentioned cured resin layer (B) is a cured product of a curable resin composition (B') containing (X) urethane (meth)acrylate and (Y) a compound having a cyclic siloxane skeleton. In paragraph 1,
A laminated film, wherein the curable resin composition (A') further comprises (Ab) a crosslinking agent and (Ac) particles, and the (Aa) binder comprises a compound having a condensed polycyclic aromatic structure. In paragraph 1,
A laminated film comprising a cured resin layer (C) between the above-described base film and the cured resin layer (A), wherein the cured resin layer (C) is a cured product of a curable resin composition (C') containing an antistatic agent, and wherein the compound having a cyclic siloxane skeleton (Y) is a fluorine compound having a cyclic siloxane skeleton and a perfluoroether structure. A laminated film having a configuration in which a cured resin layer (A) and a cured resin layer (D) are sequentially laminated on at least one surface of a base film, wherein the cured resin layer (A) is a cured product of a curable resin composition (A') containing (A-a) a binder, (A-b) a crosslinking agent, and (A-c) particles, and wherein the cured resin layer (D) is a cured product of a curable resin composition (D') containing (D-a) a trifunctional or higher (meth)acrylate, (D-b) a quaternary ammonium base-containing polymer, and (D-c) a compound having a fluorine atom-containing structure and a cyclic siloxane structure. In the second paragraph,
A laminated film, wherein the compound having the above (Y) cyclic siloxane skeleton is a fluorine compound having a perfluoroether structure. In clause 4 or 5,
A laminated film, wherein the ratio (F2/F1) of the fluorine atomic concentration (F2; Atomic%) at a point where Ar etching is performed for 10 seconds at an acceleration voltage of 200 eV to the fluorine atomic concentration (F1: Atomic%) of the uppermost surface (surface of the cured resin layer) of the laminated film, as measured by X-ray photoelectron spectroscopy (XPS), is 0.2 or less. In the second paragraph,
A laminated film, wherein, when the following steel-resistant test is performed on the surface of the above-mentioned cured resin layer (B), the rate of change in film haze after 2000 round trips is less than 1%;
(Nestle Wool Test)
The uppermost surface of the cured resin layer (B) is rubbed 2,000 times back and forth at a speed of 50 mm/sec while applying a load of 1 kg in a 2 cm by 2 cm dimension using #0000 steel wool in a friction tester, and the haze value of the laminated film before and after the friction is measured, and the rate of change from the initial film haze (film haze before friction) is calculated.
Change rate (%) = (film haze after friction - initial film haze) / initial film haze × 100 In paragraph 4,
A laminated film having a number of reciprocating cycles of 1,000 or more as measured by the abrasion resistance evaluation of the above-mentioned cured resin layer (D).
(Evaluation of the internal abrasion resistance)
The uppermost surface of the cured resin layer (D) was rubbed back and forth at a speed of 50 mm/sec using steel wool No. 0000 in a friction tester while applying a load of 1 kg in a 2 cm by 2 cm dimension. The presence or absence of scratches on the surface of the cured resin layer (D) was visually checked, and the haze value was measured. The number of reciprocations at which there were no scratches visible to the naked eye and the change from the initial film haze was less than 1% was measured. In the third paragraph,
A laminated film having a number of reciprocating cycles of 2,000 or more as measured by the abrasion resistance evaluation of the above-mentioned cured resin layer (B).
(Evaluation of the internal abrasion resistance)
The uppermost surface of the cured resin layer (B) was rubbed back and forth at a speed of 50 mm/sec using steel wool No. 0000 in a friction tester while applying a load of 1 kg in a 2 cm by 2 cm dimension. The presence or absence of scratches on the surface of the cured resin layer (B) was visually checked, and the haze value was measured. The number of reciprocations at which there were no scratches visible to the naked eye and the change from the initial film haze was less than 1% was measured. In the second or third paragraph,
A laminated film having a number of repeated bendings of 200,000 or more in the following repeated bending tests;
(Repeated bending test)
Using a bending tester, a bending test is performed with a minimum radius R=1.5 so that the cured resin layer side of the laminated film becomes the inner surface, and the presence or absence of cracks in the cured resin layer on the inner surface is visually confirmed, and the number of repeated bends until cracks occur is measured. In any one of paragraphs 2 to 4,
A laminated film having a film haze of 1.0% or less. In the second paragraph,
A laminated film, wherein the elongation at break of the cured resin layer (A) and the cured resin layer (B) (cured resin layer) is 0.5% or more. In the second or third paragraph,
A laminated film having a light transmittance of 380 nm at the surface of the cured resin layer (B) of 3% or less. In the second or third paragraph,
A laminated film having a maximum reflectivity difference of 1.5% or less at a wavelength of 500 to 600 nm on the surface of the cured resin layer (B). In any one of paragraphs 2 to 4,
A laminated film, wherein the above-mentioned film contains an ultraviolet absorber. In any one of paragraphs 2 to 4,
A laminated film, wherein the above-mentioned cured resin layer (A) contains (Ac) particles, and the (Ac) particles are two types of particles having different particle sizes. In the second paragraph,
A laminated film, wherein the compound having the above condensed polycyclic aromatic structure is a polyester resin having a condensed polycyclic aromatic structure. In paragraph 4,
A laminated film, wherein the above (Aa) binder comprises a compound having a condensed polycyclic aromatic structure. In any one of paragraphs 2 to 4,
A laminated film, wherein the above-mentioned film is a polyester film. In any one of paragraphs 2 to 4,
A laminated film, wherein the above-described film is a polyethylene terephthalate (PET) film. In Article 19,
A laminated film having a retardation (Re) of 1400 nm or less when light having a wavelength of 590 nm is incident on the polyester film surface at an angle of 0°. In Article 19,
A laminated film, wherein the change in retardation (Re) in the true axis direction when light having a wavelength of 590 nm is incident on the polyester film surface at an angle of 0° is 10 nm or more and 600 nm/m or less. In the second or third paragraph,
A laminated film having a thickness of the above-mentioned cured resin layer (B) of 10.0 ㎛ or less. In any one of paragraphs 2 to 4,
Laminated film for surface protection. In Article 24,
Laminated film for display purposes. In Article 25,
Laminated film for front panel.