CN117794987A

CN117794987A - Film containing methacrylate resin as main component

Info

Publication number: CN117794987A
Application number: CN202280052866.XA
Authority: CN
Inventors: 安本宪朗; 宫村康史; 高野敬司
Original assignee: Denka Co Ltd
Current assignee: Denka Co Ltd
Priority date: 2021-08-06
Filing date: 2022-07-19
Publication date: 2024-03-29
Also published as: CN117715757A

Abstract

The invention provides a resin film having both high transparency and excellent blocking resistance. A film comprising crosslinked (meth) acrylate resin particles and a methacrylic resin as a main component, wherein the crosslinked (meth) acrylate resin particles have an average particle diameter of 1% to 10% relative to the average thickness of the film, the film does not contain a vinylidene fluoride resin, and the film is based on JIS K7136: the haze measured at 2000 was 5% or less, and the Clarity (CLR) of the film calculated from the following formula was 97% or more. Clr=100× (Ic-Ir)/(ic+ir), where Ic represents the light quantity of light traveling straight with respect to the optical axis of parallel light incident perpendicularly to the surface of the film among the light transmitted through the film, and Ir represents the light quantity of narrow angle scattered light having an angle of ±2.5° or less with respect to the optical axis of parallel light.

Description

Film containing methacrylate resin as main component

Technical Field

The present invention relates to a single-layer film or a laminated film including a film containing a methacrylate resin as a main component. In particular, the present invention relates to a single-layer film or a laminated film that can be applied as the outermost layer of a metal-like decorative film.

Background

Conventionally, a resin film containing a vinylidene fluoride resin is excellent in weather resistance and chemical resistance, and therefore, is suitable for use as an outermost layer (generally referred to as a "protective layer") of a decorative film used for interior or exterior decoration of an automobile, an electric appliance member, or the like. The decorative film is generally produced through a process of bonding a decorative layer to a film of the outermost layer. As a bonding method, lamination using an adhesive and thermal lamination are generally used.

In recent years, the design of automobile interior decoration has been diversified and complicated, and in order to prevent the color and feel from being impaired, the outermost layer of the decorative film is required to have high transparency. Particularly, among the decorative films, a metal-like decorative film produced by metal vapor deposition of a resin film for the purpose of imparting a metal-like design is required to have an outermost layer with high transparency. Accordingly, a technique for improving the transparency of a resin film containing a vinylidene fluoride resin has been developed.

In patent document 1 (international publication No. 2011/142453), in order to provide a film having high crystallinity, transparency, and surface smoothness, a film is proposed which contains a vinylidene fluoride resin (a) and an acrylic resin (B), has an arithmetic average roughness of at least one surface of 0.1 to 20nm, has a heat of fusion of 18 to 40J/g as measured by a differential scanning calorimeter, and has a haze value of 3.5 or less.

Patent document 2 (japanese patent application laid-open No. 2012-187934) describes that a novel fluororesin film, which is excellent in transparency, surface hardness, chemical resistance and stain resistance, is successfully produced by using a fluorine-based (meth) acrylic resin containing a fluoroalkyl (meth) acrylate component, and can also be used for the purpose of interior and exterior parts of a vehicle. Further, this document specifically discloses a fluororesin laminated acrylic resin film in which a fluororesin film layer is laminated on at least one surface of a film layer formed of an acrylic resin (a), the fluororesin film layer being formed by molding a fluororesin (C) containing a fluororesin (meth) acrylic resin (B) containing a fluoroalkyl (meth) acrylate polymer component.

Prior art literature

Patent literature

Patent document 1: international publication No. 2011/142453

Patent document 2: japanese patent application laid-open No. 2012-187934

Disclosure of Invention

Problems to be solved by the invention

As described above, techniques for improving the transparency and the like of a resin film used as the outermost layer of a decorative film are known. However, the resin film is often provided in the form of a film roll wound in a roll shape, but there is a problem in that films are easily adhered (stuck) to each other during the process of keeping the tube. If the resin films are peeled off from each other when the resin films are taken out from the film roll, the surface of the resin film becomes rough. Therefore, there is room for improvement in the conventional resin film when it is considered to be applied to a decorative film requiring an excellent appearance, particularly a metal-like decorative film (for example, a metal-like decorative film having a metal mirror-like appearance).

The present invention has been made in view of the above circumstances, and an object thereof is to provide a resin film having both high transparency and excellent blocking resistance in one embodiment.

Means for solving the problems

As a result of intensive studies to solve the above problems, the inventors of the present application have found that it is effective to add crosslinked (meth) acrylate resin particles of a predetermined size to a film containing a methacrylate resin as a main component and containing no vinylidene fluoride resin, and have completed the present invention as exemplified below.

[1]

A film containing crosslinked (meth) acrylate resin particles and containing a methacrylate resin as a main component,

the crosslinked (meth) acrylate resin particles have an average particle diameter of 1% to 10% relative to the average thickness of the film,

the film does not contain a vinylidene fluoride resin,

the film was based on JIS K7136: haze measured at 2000 is 5% or less,

the film has a Clarity (CLR) of 97% or more as calculated by the following formula.

CLR＝100×(Ic-Ir)/(Ic+Ir)

Where Ic represents the light quantity of light traveling straight with respect to the optical axis of parallel light incident perpendicularly to the surface of the film, and Ir represents the light quantity of narrow angle scattered light having an angle of ±2.5° or less with respect to the optical axis of parallel light.

[2]

The film according to [1], wherein the amount of the crosslinked (meth) acrylate resin particles is 0.1 parts by mass or more and 2 parts by mass or less based on 100 parts by mass of the methacrylate resin.

[3]

A laminated film is provided with:

[1] or the film of [2], and

a vinylidene fluoride resin-containing film laminated on one surface of the film;

the laminated film is based on JIS K7136: haze measured at 2000 is 5% or less, clarity (CLR) is 97% or more, and is based on JIS Z8741: the 60 DEG specular gloss on the outer surface side of the film containing a vinylidene fluoride resin measured in 1997 is 100 or more.

[4]

The laminate film according to [3], wherein the film containing a vinylidene fluoride resin contains (A) in an amount of 50 to 80 parts by mass and (B) in an amount of 20 to 50 parts by mass based on 100 parts by mass of the total of 1 or 2 kinds (A) selected from the group consisting of a copolymer of vinylidene fluoride and hexafluoropropylene and polyvinylidene fluoride, and the methacrylate resin (B).

[5]

The metal-like decorative film of [1] or [2] wherein the film is laminated as the outermost layer, or of [3] or [4] wherein the laminated film is laminated so that the vinylidene fluoride resin-containing film is outside the outermost layer.

Effects of the invention

According to one embodiment of the present invention, a single-layer film or a laminated film having both high transparency and excellent blocking resistance can be obtained. The single-layer film or the laminated film can be used by being attached to a substrate, and for example, can be suitably used as an outermost layer of a decorative film, particularly a metal-like decorative film.

Drawings

Fig. 1 is a schematic cross-sectional view showing a laminated structure of films according to a second embodiment of the present invention.

Detailed Description

Hereinafter, embodiments of the present invention will be described. The embodiments described below exemplarily show representative embodiments of the present invention, and are not intended to interpret the technical scope of the present invention in a narrower manner accordingly.

(1. First embodiment)

The film according to the first embodiment may be composed of a resin composition containing crosslinked (meth) acrylate resin particles and containing a methacrylate resin as a main component.

In the present specification, the term "methacrylate-based resin" refers to a homopolymer of a methacrylate such as methyl methacrylate, or a copolymer of a methacrylate and a monomer copolymerizable with the methacrylate, and refers to particles having a particle diameter of less than 0.2 μm in a film (including particles having a particle diameter as small as possible and particles forming a matrix phase). In contrast, the resin particles having a particle diameter of 0.2 μm or more in the film are not included in the methacrylate resin in the present specification. The particle diameter of the resin particles means: the film was held and fixed by a small metal vice, and the film was cut so that the cross section was smooth by a single blade knife, and when the film was observed with a confocal laser microscope (for example, VK-X110 manufactured by KEYENCE corporation) at a magnification of 2000 times in a state where the film was held by the vice, the diameter of the smallest circle that could surround the resin particles was obtained.

As the monomer copolymerizable with the methacrylate ester, there are (meth) acrylic esters such as butyl acrylate, butyl methacrylate, ethyl acrylate, and ethyl methacrylate; aromatic vinyl monomers such as styrene, α -methylstyrene, p-methylstyrene, o-methylstyrene, t-butylstyrene, divinylbenzene, and triphenylethylene; vinyl cyanide monomers such as acrylonitrile and methacrylonitrile; glycidyl group-containing monomers such as glycidyl (meth) acrylate; vinyl carboxylate monomers such as vinyl acetate and vinyl butyrate; olefin monomers such as ethylene, propylene, and isobutylene; diene monomers such as 1, 3-butadiene and isoprene; unsaturated carboxylic acid monomers such as maleic acid, maleic anhydride, and (meth) acrylic acid; vinyl methyl ketone and other ketene monomers, can be used alone or in combination of 2 or more. Among them, from the viewpoints of strength and flexibility of the film, a homopolymer of methyl methacrylate or an acrylic rubber-modified methacrylic copolymer obtained by copolymerizing a monomer mainly composed of methyl methacrylate with an acrylic rubber containing butyl (meth) acrylate is preferable.

Examples of the copolymer include a random copolymer, a graft copolymer, a block copolymer (for example, a linear type such as a diblock copolymer, a triblock copolymer, or a gradient copolymer, a star-shaped copolymer obtained by polymerization by a core-before-arm method or a core-before-arm method, and the like), a copolymer obtained by polymerization of a macromonomer using a polymer compound having a polymerizable functional group (a macromonomer copolymer), and a mixture thereof. Among them, graft copolymers and block copolymers are preferable from the viewpoint of productivity of the resin.

Examples of the polymerization reaction for obtaining the methacrylate resin include known polymerization reactions such as radical polymerization, living anion polymerization, and living cation polymerization. Further, as the polymerization method, known polymerization methods such as bulk polymerization, suspension polymerization, emulsion polymerization, and solution polymerization are mentioned. The mechanical properties of the resulting resin change according to the polymerization reaction and polymerization method.

The film according to the first embodiment contains a methacrylate resin as a main component, and refers to a film in which the methacrylate resin is the component having the largest mass ratio among the components of the film. The amount of the methacrylate resin blended in the film is preferably 50% by mass or more, more preferably 70% by mass or more, still more preferably 90% by mass or more, still more preferably 95% by mass or more, and may be set to 50 to 99% by mass, for example.

The film according to the first embodiment contains crosslinked (meth) acrylate resin particles in addition to the methacrylate resin. In a typical embodiment, the crosslinked (meth) acrylate resin particles are present in a state dispersed in a matrix of the methacrylate resin. Since the refractive index of the crosslinked (meth) acrylate resin particles is similar to that of the methacrylate resin as a main component, the crosslinked (meth) acrylate resin particles have the following characteristics: even if dispersed in the methacrylate resin, the transparency of the film is not easily impaired.

In the present specification, the crosslinked (meth) acrylate resin particles refer to resin particles having a particle diameter of 0.2 μm or more in the film. The particle diameter of the resin particles means the diameter of the smallest circle that can surround the resin particles when the film is observed by the above method. Therefore, even in the case of a particulate crosslinked (meth) acrylate resin, the resin particles having a particle diameter of less than 0.2 μm in the film belong to the methacrylate resin as long as the above definition concerning the methacrylate resin is satisfied.

The crosslinked (meth) acrylate resin particles in the film preferably have an average particle diameter of 1% to 10% relative to the average thickness of the film. The crosslinked (meth) acrylate resin particles preferably have an average particle diameter of 1% or more, more preferably 2% or more, still more preferably 3% or more, relative to the average thickness of the film, whereby moderate irregularities can be imparted to the film surface, and the blocking resistance can be improved. Further, the crosslinked (meth) acrylate resin particles preferably have an average particle diameter of 10% or less, more preferably 9% or less, still more preferably 8% or less, still more preferably 7% or less, still more preferably 6% or less, relative to the average thickness of the film, whereby the roughness of the film surface is not excessively increased, and the sharpness of the film can be improved.

As described above, the preferable range of the average particle diameter of the crosslinked (meth) acrylate resin particles is desirably defined according to the relationship with the average thickness of the film. Therefore, the average particle diameter of the crosslinked (meth) acrylate resin particles is not particularly important, but in view of the thickness of the film generally conceived, the average particle diameter of the crosslinked (meth) acrylate resin particles is preferably 0.5 to 5. Mu.m, more preferably 0.5 to 2. Mu.m. In the present specification, the average particle diameter of the crosslinked (meth) acrylate resin particles refers to the D50 value (volume basis) of the particle size distribution measured by a laser diffraction/scattering method.

The average thickness of the film according to the first embodiment is preferably 10 to 100. Mu.m, more preferably 15 to 90. Mu.m, still more preferably 20 to 85. Mu.m, particularly preferably 25 to 80. Mu.m. When the average thickness of the film is 10 μm or more, the film forming property is improved, and the protective function when used as the outermost layer of the laminated film can be improved, and by setting the thickness to 100 μm or less, the transparency and the processability can be improved. The film according to the first embodiment may be formed of a single layer or a plurality of layers, but it is desirable to have the total average thickness fall within the above average thickness range. The average thickness of the film can be calculated as an average value when the thicknesses of a plurality of portions are measured by observing the film cross section using a confocal laser microscope.

The crosslinked (meth) acrylic resin particles are not limited, and examples thereof include crosslinked polymethyl acrylate, crosslinked polyethyl acrylate, crosslinked polymethyl methacrylate, crosslinked polyethyl methacrylate, and crosslinked n-butyl methacrylate, and may be used alone or in combination of 2 or more. Among them, the crosslinked polymethyl methacrylate is preferably contained because the difference between the refractive index of the resin and the refractive index of the methacrylate resin constituting the matrix is small. Even when heat is applied during the production of a film, the crosslinked (meth) acrylate resin particles are not compatible with the methacrylate resin constituting the matrix due to the crosslinked structure, and are easily maintained.

The film according to the first embodiment can improve transparency when the amount of the crosslinked (meth) acrylate resin particles blended is small, but can improve blocking resistance when the amount blended is large. Therefore, from the viewpoint of achieving both transparency and blocking resistance, the amount of the crosslinked (meth) acrylate resin particles to be blended is preferably 0.1 part by mass or more and 2 parts by mass or less, more preferably 0.3 part by mass or more and 1.5 parts by mass or less, and even more preferably 0.5 part by mass or more and 1 part by mass or less, relative to 100 parts by mass of the methacrylate resin.

The lower limit of the glass transition temperature (Tg) of the methacrylate resin is preferably 70℃or higher, more preferably 80℃or higher. The upper limit of Tg of the methacrylate resin is preferably 120℃or lower.

Tg of the methacrylate-based resin can be measured by a calorimetric measurement (heat flux DSC) of a heat flux difference scan. For example, it can be obtained from a DS C curve (first run) obtained when the sample is heated to 200℃from room temperature under conditions of a sample mass of 1.5mg and a heating rate of 10℃per minute using a differential scanning calorimeter DSC3100SA manufactured by Bruker AXS.

From the viewpoint of improving transparency, the film according to the first embodiment is based on JIS K7136: the haze measured at 2000 is preferably 5% or less, more preferably 4% or less, and may be set in the range of 1 to 5%, for example.

In one embodiment, the film according to the first embodiment may have a Clarity (CLR) calculated by the following formula of 97% or more, preferably 98% or more, more preferably 99% or more, and may be set to 97 to 99.5%, for example.

CLR＝100×(Ic-Ir)/(Ic+Ir)

Where Ic represents the light quantity of light traveling straight with respect to the optical axis of parallel light incident perpendicularly to the surface of the film, and Ir represents the light quantity of narrow angle scattered light having an angle of ±2.5° or less with respect to the optical axis of parallel light. In the measurement, CIE-D65 illuminant was used as illuminant.

Clarity is a similar parameter to haze, but good haze does not necessarily mean that Clarity (CLR) is good. Haze is a parameter for evaluating optical properties of a film perceived by an observer using wide-angle scattered light (transmitted light that deviates by 2.5 ° or more from incident light due to forward scattering). On the other hand, sharpness is a parameter for evaluating optical properties of a film perceived by an observer using narrow angle scattered light. Therefore, it can be said that haze evaluates the degree of haze of the film, whereas clarity evaluates the degree of sharpness of the outline of the article when the article is viewed through the film. That is, the definition is high in addition to the haze, which means that: in the case of using the film attached to the surface of the article, the design presented on the surface of the article can be faithfully viewed. For example, in the case where the article is a substrate of a metal-like decorative film, the metallic luster of the substrate surface can be clearly observed even after the film is attached.

From the viewpoint of improving transparency, the film according to the first embodiment is based on JIS K7361-1: the total light transmittance measured in 1997 is preferably 80% or more, more preferably 85% or more, still more preferably 90% or more, and may be set to 80 to 95%, for example.

The film according to the first embodiment may contain, in addition to the methacrylate resin and the crosslinked (meth) acrylate resin particles, an ultraviolet absorber, other resin, plasticizer, heat stabilizer, antioxidant, light stabilizer, nucleating agent, antiblocking agent, sealing agent, mold release agent, colorant, pigment, foaming agent, flame retardant and the like as appropriate within a range not to impair the object of the present invention. However, in general, the total content of the methacrylate resin and the crosslinked (meth) acrylate resin particles in the film according to the first embodiment is 90 mass% or more, typically 95 mass% or more, more typically 97 mass% or more, and may be set to 100 mass% or more. In addition, from the viewpoint of improving transparency, particularly sharpness, it is desirable that the film according to the first embodiment does not contain a vinylidene fluoride resin.

The film according to the first embodiment preferably contains an ultraviolet absorber. By incorporating the ultraviolet absorber in the resin composition, ultraviolet rays are blocked, and weatherability can be effectively improved. The ultraviolet absorber is not limited, and examples thereof include hydroquinone-based, triazine-based, benzotriazole-based, benzophenone-based, cyanoacrylate-based, oxanilide-based, hindered amine-based, salicylic acid derivative-based, and the like, and these may be used singly or in combination of 2 or more. Among them, the triazine compound, the benzotriazole compound, or a mixture thereof is preferably contained in view of the durability of the ultraviolet blocking effect.

The amount of the ultraviolet absorber blended in the film according to the first embodiment is preferably 0.1 to 10 parts by mass per 100 parts by mass of the methacrylate resin. The amount of the ultraviolet absorber blended in the resin composition is set to 0.1 part by mass or more, preferably 1 part by mass or more, more preferably 2 parts by mass or more, based on 100 parts by mass of the methacrylate resin, whereby an effect of improving weather resistance and an effect of absorbing ultraviolet light can be expected, and the amount of the ultraviolet absorber blended in the resin composition is set to 10 parts by mass or less, preferably 5 parts by mass or less, based on 100 parts by mass of the methacrylate resin, whereby bleeding of the ultraviolet absorber to the film surface can be prevented, and cost reduction can be achieved.

The film according to the first embodiment can be produced by performing the following steps.

Step 1: and a step of melt extrusion molding a resin composition containing a methacrylate resin and 0.1 to 2 parts by mass of crosslinked (meth) acrylate resin particles per 100 parts by mass of the methacrylate resin, from a T die at a temperature of 200 to 260 ℃.

Step 2: and a step of cooling the film obtained by melt extrusion molding by bringing at least one surface of the film into contact with a surface of a metal roll whose temperature has been adjusted to 30 to 60 ℃ after extrusion from an outlet of the T die.

When a film having a thickness of about 30 to 50 μm is produced under the above conditions, the film transport speed is suitably set to 3 to 7 m/min. In addition, in the case where a screen is provided in the extruder from the viewpoint of removing foreign matters, the mesh of the screen needs to be adjusted to a size through which the crosslinked (meth) acrylate resin particles can pass.

As a method of adjusting the temperature of the surface of the metal roll, for example, a method of circulating a cooling medium such as cooling water in the metal roll can be mentioned.

Examples of the method of melt extrusion molding include a T-die method for forming a film using a T-die and a method using a blow die. From the viewpoint of transferring the smooth surface of the metal roll to the film, it is more preferable that a rubber contact roll is disposed opposite to the metal roll during cooling, and the molten resin composition extruded from the outlet of the die is sandwiched between the metal roll (casting roll) and the contact roll. The surface temperature of the rubber contact roller is preferably 0 to 70 ℃, more preferably 0 to 30 ℃, from the viewpoint of suppressing transfer of the surface shape of the rubber roller.

From the viewpoint of reducing the surface roughness of the film, it is desirable that the surface roughness of the metal roller is small, and further, that the surface roughness of the contact roller is also small. Reducing the surface roughness of the film is advantageous for reducing the haze value of the film and improving the sharpness. This is because the surface roughness of the metal roller and the contact roller is reflected on the surface roughness of the film. Thus, the metallic roller is based on JIS B0601: the arithmetic average roughness Ra measured in 2001 is preferably 100nm or less, more preferably 80nm or less, still more preferably 60nm or less, still more preferably 40nm or less, still more preferably 20nm or less, and may be set to, for example, 10 to 100nm. JIS B0601-based on the surface of the contact roller: the arithmetic average roughness Ra measured in 2001 is preferably 150nm or less, more preferably 120nm or less, and may be set to 100 to 150nm, for example.

(2. Second embodiment)

Fig. 1 shows a schematic cross-sectional view showing a laminated structure of a film 1 according to a second embodiment. The film 1 has a laminated structure including at least a surface layer 10 and a back layer 20 laminated on the surface layer 10 in this order. Typically, no other resin layer is sandwiched between the surface layer 10 and the back surface layer 20, and the two are directly bonded.

In one embodiment, the surface layer is composed of a film containing a vinylidene fluoride resin. The film constituting the surface layer preferably contains a vinylidene fluoride resin and a methacrylate resin.

The mixing ratio of the vinylidene fluoride resin and the methacrylate resin in the film constituting the surface layer is preferably such that the vinylidene fluoride resin/methacrylate resin=50 to 80 parts by mass, 20 to 50 parts by mass, more preferably 60 to 75 parts by mass, and 25 to 40 parts by mass, relative to 100 parts by mass of the total of the both. When the amount of the vinylidene fluoride resin is 50 parts by mass or more based on 100 parts by mass of the total of the vinylidene fluoride resin and the methacrylate resin, the properties such as chemical resistance, weather resistance and stain resistance can be improved. In addition, by containing a small amount of a methacrylate resin in the film constituting the surface layer, adhesion and adhesiveness to the back surface layer can be improved.

In the present specification, the vinylidene fluoride resin refers to a homopolymer of vinylidene fluoride and a copolymer of vinylidene fluoride and a monomer copolymerizable with vinylidene fluoride. Examples of the monomer copolymerizable with vinylidene fluoride include known vinyl monomers such as vinyl fluoride, tetrafluoroethylene, hexafluoropropylene, hexafluoroisobutylene, chlorotrifluoroethylene, various fluoroalkyl vinyl ethers, and styrene, ethylene, butadiene, and propylene, and may be used alone or in combination of 2 or more. Among them, at least 1 selected from the group consisting of vinyl fluoride, tetrafluoroethylene, hexafluoropropylene and chlorotrifluoroethylene is preferable, and hexafluoropropylene is more preferable.

Therefore, the film constituting the surface layer preferably contains (a) in a total of 50 to 80 parts by mass and (B) in a total of 20 to 50 parts by mass, based on 100 parts by mass of the total of 1 or 2 kinds (a) selected from the group consisting of a copolymer of vinylidene fluoride and hexafluoropropylene and a polyvinylidene fluoride (PVDF homopolymer), and a methacrylate resin (B); more preferably, the amount of (A) is 60 to 75 parts by mass, and the amount of (B) is 25 to 40 parts by mass.

Examples of the polymerization reaction for obtaining a vinylidene fluoride resin include known polymerization reactions such as radical polymerization and anionic polymerization. Further, as the polymerization method, known polymerization methods such as suspension polymerization and emulsion polymerization are mentioned. The mechanical properties and the like of the obtained resin are changed according to the polymerization reaction and/or the polymerization method.

The lower limit of the melting point of the vinylidene fluoride resin is preferably 150 ℃ or higher, more preferably 160 ℃ or higher. The upper limit of the melting point of the vinylidene fluoride resin is preferably 170 ℃ or less which is equal to the melting point of polyvinylidene fluoride (PV DF).

The melting point of the vinylidene fluoride resin and the Tg of the methacrylate resin can be measured by a thermal mass spectrometry (heat flux DSC). For example, the measurement can be performed using a differential scanning calorimeter DSC3100SA manufactured by Bruker AXS, from a DSC curve (first run) obtained when the sample is heated from room temperature to 200℃under conditions of a sample mass of 1.5mg and a heating rate of 10℃per minute.

The film constituting the surface layer may contain, in addition to the vinylidene fluoride resin and the methacrylate resin, other resins, plasticizers, heat stabilizers, antioxidants, light stabilizers, nucleating agents, antiblocking agents, sealing modifiers, mold release agents, colorants, pigments, foaming agents, flame retardants, and the like as appropriate within a range not to impair the object of the present invention. However, the total content of the vinylidene fluoride resin and the methacrylate resin in the film constituting the surface layer is usually 80 mass% or more, typically 90 mass% or more, more typically 95 mass% or more, and may be set to 100 mass%.

In a preferred embodiment, the total content of 1 or 2 (a) selected from the group consisting of a copolymer of vinylidene fluoride and hexafluoropropylene and polyvinylidene fluoride (PVDF homopolymer) and a methacrylate-based resin (B) in the film constituting the surface layer is 80 mass% or more, typically 90 mass% or more, more typically 95 mass% or more, and may be set to 100 mass%.

The ultraviolet absorber may be added to the film constituting the surface layer, but from the viewpoint of cost and bleeding, it is preferable not to add the ultraviolet absorber.

The average thickness of the film constituting the surface layer is preferably 1 to 40. Mu.m, more preferably 5 to 35. Mu.m, still more preferably 8 to 30. Mu.m, particularly preferably 10 to 20. Mu.m. When the average thickness of the film is 1 μm or more, the film forming property is improved, and the protective function when used as the outermost layer can be improved, and by setting the thickness to 40 μm or less, the improvement in transparency and the reduction in cost can be achieved. The film constituting the surface layer may be formed of a single layer or may be formed of a plurality of layers, but it is desirable to have the total average thickness fall within the above-mentioned average thickness range. The average thickness of the film can be calculated as an average value when the thicknesses of a plurality of portions are measured by observing the film cross section using a confocal laser microscope.

On the other hand, the embodiments of the film constituting the back layer, including the composition, average particle diameter, average thickness, haze, clarity, and total light transmittance of the crosslinked (meth) acrylate resin particles, are applicable to the same description as those of the film according to the first embodiment, and therefore, the description thereof is omitted.

From the viewpoint of improving transparency, the film according to the second embodiment is based on JIS K7136: the haze measured at 2000 is preferably 5% or less, more preferably 4% or less, and may be set in the range of 1 to 5%, for example.

In the film according to the second embodiment, in one embodiment, the Clarity (CLR) described in relation to the film according to the first embodiment is 97% or more, preferably 98% or more, more preferably 99% or more, and may be set to 97 to 99.5%, for example.

From the viewpoint of improving transparency, the film according to the second embodiment is based on JIS Z8741: the 60 ° specular gloss on the outer surface side of the surface layer (vinylidene fluoride resin-containing film) measured in 1997 is preferably 100 or more, more preferably 110 or more, still more preferably 120 or more, and may be set to, for example, 100 to 130.

The laminated film in which the surface layer and the back layer are laminated can be produced by, for example, a melt coextrusion method in which a plurality of resins are bonded and laminated in a molten state by a plurality of extrusion molding machines. The melt coextrusion molding method comprises the following modes: in the multi-manifold die head mode, after a plurality of resins are made into a sheet, each layer is contacted and bonded at the front end inside the T die; a feed block die head mode, wherein a plurality of resins are adhered in a converging device (feed block) and then spread into a sheet shape; and a double slot die (dual slot die) method, wherein after a plurality of resins are formed into a sheet, the layers are contacted and bonded at the front end outside the T die. In addition, the molded article can be produced by an inflation molding method using a circular die.

The film according to the second embodiment can be produced by performing the following steps.

Step 1: a second resin composition comprising a first resin composition comprising a vinylidene fluoride resin and 0.1 to 2 parts by mass of crosslinked (meth) acrylate resin particles per 100 parts by mass of the methacrylate resin,

and a step of melt coextrusion molding in a film form from a T die at a temperature of 200 to 260 ℃ so that the average thickness of the first resin composition is 1 to 40 [ mu ] m and the average thickness of the second resin composition is 10 to 100 [ mu ] m.

Step 2: and a step of cooling the film obtained by melt coextrusion molding by bringing at least the first resin composition side surface of the film into contact with the surface of a metal roll whose temperature has been adjusted to 30 to 60 ℃ after extrusion from the outlet of the T die.

When a film having a thickness of about 30 to 50 μm is produced under the above conditions, the film transport speed is suitably set to 5 to 9 m/min. In addition, in the case where a screen is provided in the extruder from the viewpoint of removing foreign matters, the mesh of the screen needs to be adjusted to a size through which the crosslinked (meth) acrylate resin particles can pass.

As a method of adjusting the temperature of the surface of the metal roll, for example, a method of circulating a cooling medium such as cooling water inside the metal roll is mentioned.

From the viewpoint of transferring the smooth surface of the metal roll to the film, it is more preferable that a rubber contact roll is disposed opposite to the metal roll during cooling, and a laminate of the first resin composition and the second resin composition in a molten state extruded from the outlet of the T-die is sandwiched between the metal roll (casting roll) and the contact roll. The surface temperature of the rubber contact roller is preferably 0 to 70 ℃, more preferably 0 to 30 ℃, from the viewpoint of suppressing transfer of the surface shape of the rubber roller.

(3. Film laminated with substrate)

The base material may be laminated on the film according to the first embodiment and the second embodiment. Accordingly, in one embodiment, the present invention can provide a film obtained by laminating a substrate on either side of the film according to the first embodiment. In another embodiment, the present invention provides a film obtained by laminating a substrate on the surface layer and/or the back surface layer of the film according to the second embodiment. When the average value of the total thickness of the film laminated with the base material is 50 to 1000 μm, it is preferable in view of workability and cost of adhesion to the automobile interior trim component.

Examples of the substrate include a decorative layer, a protective layer, an adhesive layer, a printed layer, a metal deposition layer, and the like. The substrate may be used in a single layer of 1 kind, or may be used in a stack of 2 or more kinds.

As described above, the films according to the first and second embodiments can have high transparency. Therefore, by applying the film to the surface of a substrate having high glossiness, the characteristics can be effectively utilized. Accordingly, in a preferred embodiment, the substrate is based on JIS Z8741 on the surface of the substrate that is bonded to the film: the 60 DEG specular gloss measured in 1997 is 100 to 600, typically 300 to 550, based on JIS Z8781-4:2013, and L of the light receiving angle 15 ° in the color space is 0 to 20, typically 0 to 5.

In a preferred embodiment, a metal-like decorative film obtained by laminating the film according to the first embodiment as the outermost layer, or a metal-like decorative film obtained by laminating the film according to the second embodiment with the surface layer (vinylidene fluoride resin-containing film) on the outside as the outermost layer may be provided.

In one embodiment, the metal-like decorative film includes, in order, the film according to the first embodiment, an anchor layer, a metal deposition layer, and an adhesive layer, and the film according to the first embodiment constitutes the outermost layer. In another embodiment, the metal-like decorative film includes, in order, the film according to the second embodiment, an anchor layer, a metal deposition layer, and an adhesive layer, and the film according to the second embodiment is configured as an outermost layer such that a surface layer (a film containing a vinylidene fluoride resin) is an outer side.

The anchor layer is not limited, and is an acrylic resin, a nitrocellulose resin, a polyurethane resin (including a resin obtained by curing a polyol resin as a main agent and an isocyanate resin as a curing agent), an acrylic urethane resin (including a resin obtained by curing an acrylic polyol resin as a main agent and an isocyanate resin as a curing agent), a polyester resin, a styrene-maleic resin, a chlorinated PP resin, or the like. Among them, the anchor layer preferably contains an acrylic resin in view of more excellent adhesion of the obtained film.

The metal deposition layer is not limited, and may include a metal such as indium. The metal deposition layer may contain various nonmetallic materials, metals, metal oxides, and metal nitrides.

The adhesive layer may contain various adhesives, binders, pressure sensitive adhesives (PSA: pres sure Sensitive Adhesive), and the like.

As a method of laminating substrates for the films according to the first and second embodiments, for example, adhesive lamination and thermal lamination are given. Other known lamination methods may also be employed. The film according to the first and second embodiments may be formed by heating. Examples of the method of the thermoforming include a method of bonding a substrate to one or both surfaces of a film and then vacuum forming, pressure forming, and vacuum pressure forming.

Examples of the method for surface coating an article such as an automobile interior part with a decorative film, particularly a metal-like decorative film, include film insert molding, in-mold molding, and vacuum lamination molding (including vacuum-pressure air molding such as TOM molding). Among them, in the case of film insert molding, since the decorative film is heated to perform preforming, there are advantages in that compared with in-mold molding and vacuum lamination molding: even for a member of a relatively complex shape, the decorative film can follow the member, and a good surface coating state can be achieved.

Examples

The present invention will be described in detail below with reference to examples, in comparison with comparative examples.

<1 Single layer film >

(1-1. Material)

< methacrylate resin >

The following materials were prepared as the methacrylate-based resin.

Mitsubishi Chemical Corporation "HIPET HBS000" (methacrylate-based resin having a Tg of 97℃of a rubber component comprising butyl acrylate (n-BA) and Butyl Methacrylate (BMA))

< crosslinked (meth) acrylate-based resin particles >

As the crosslinked (meth) acrylate resin particles, the following materials were prepared.

Aica Kogyo Co., ltd., "GM-0105" (crosslinked methyl methacrylate-based resin particles) (average particle diameter=2.5 μm)

"MX-80H3wT" (crosslinked methyl methacrylate resin particles) manufactured by Zodiac Co., ltd.) (average particle diameter=0.81 μm)

"MR-1HG" (crosslinked methyl methacrylate resin particles) (average particle diameter=1.2 μm) manufactured by Zodiac chemical Co., ltd

Aica Kogyo Co., ltd., "GM-0449S-2" (crosslinked methyl methacrylate-based resin particles) (average particle diameter=3.7 μm)

Aica Kogyo Co., ltd., "GM-0806S" (crosslinked methyl methacrylate-based resin particles) (average particle diameter=8.2 μm)

In any of the above-mentioned types of particles, particles having a particle diameter of less than 0.2 μm are substantially absent, and therefore, it can be considered that the total amount blended constitutes crosslinked (meth) acrylate resin particles in the film.

The average particle diameter is the D50 value (based on volume) of the particle size distribution measured by the laser diffraction/scattering method. The D50 value, which is sometimes referred to as a median particle diameter, is a particle diameter at which the cumulative particle size distribution from the side having a smaller particle diameter becomes 50%. Examples of the measuring device include Mastersizer 2000 (manufactured by Malvern Panalytical).

< ultraviolet absorber >

As the ultraviolet absorber, the following materials were prepared.

Triazine ultraviolet absorber "Tinuvin (registered trademark) 1600" manufactured by BASF corporation "

(1-2. Film production)

According to the test numbers, the formulation shown in Table 1 was usedAfter kneading by a twin-screw extruder, each compound was obtained. Use->The obtained composites were melt-extruded by a T-mode single screw extruder, and the extruded film-like resin composition was cooled by being nipped by a metal roll (surface temperature: about 40 ℃) and a rubber-made contact roll (surface temperature: about 20 ℃) through which cooling water was circulated while being conveyed at a conveying speed of 4.5m/min, to obtain films having average thicknesses as shown in table 1. Here, JIS B0601 based on the surface of the metal roll was measured with a contact surface roughness meter (Mitutoyo, SJ210, inc.) to: the arithmetic average roughness Ra measured in 2001 was 0.013 μm. Based on JIS B0601, on the surface of the contact roller with a contact surface roughness meter (Mitutoyo, SJ210, co., ltd.): the arithmetic average roughness Ra measured in 2001 was 0.116. Mu.m.

<2 > laminated film >

(2-1. Material)

Surface layer (vinylidene fluoride resin-containing film)

< vinylidene fluoride resin >

As vinylidene fluoride resin (PVDF), the following materials were prepared.

Kynar1000HD (PVDF homopolymer with melting point 168 ℃ C.) manufactured by Arkema Co

< methacrylate resin >

The following materials were prepared as the methacrylate-based resin.

Sumipex MGSS, sumitomo chemical Co., ltd. (polymethyl methacrylate with Tg of 101 ℃ C.)

For the back surface layer (film containing a methacrylate resin as a main component)

The same materials as the single-layer film were prepared as the methacrylate resin, the crosslinked (meth) acrylate resin particles, and the ultraviolet absorber.

(2-2. Film production)

According to the test numbers, the following formulation is used as described in Table 2After kneading by a twin-screw extruder, each of the composites for the surface layer and the back layer was obtained. For the surface layer compound and the back layer compound, 2 +.>The single screw extruder and a T-die multi-layer extruder of a feed block system having a feed block and a T-die at the front end were melt-co-extrusion molded, and the extruded film-like resin composition was cooled by being held between a metal roll (surface temperature: about 20 ℃) and a rubber contact roll (surface temperature: about 40 ℃) in which cooling water was circulated while being conveyed at a conveying speed of 6.7m/min, to obtain a laminated film having an average thickness as shown in Table 2. Here, JIS B0601 based on the surface of the metal roll was measured with a contact surface roughness meter (Mitutoyo, SJ210, inc.) to: the arithmetic average roughness Ra measured in 2001 was 0.013 μm. Using contact surface roughness gauges (Mitutoyo, kyowa, co., ltd., SJ 210) based on JIS B0601 on the surface of a contact roller: the arithmetic average roughness Ra measured in 2001 was 0.116. Mu.m.

<3 > film Properties

(3-1. Average film thickness)

For each film produced under the above conditions (length in the width direction: 800 mm), a confocal laser microscope (manufactured by KEYENCE, VK-X100) was used, and the cross section of the film was observed at 2000 times magnification, and the thickness of the film (in the case of a laminated film, each thickness of the surface layer and the back layer) was measured based on the distance between 2 points. The measurement at 17 was performed at 50mm intervals in the film width direction (TD) at any 1 in the running direction (MD), and the average value was taken as the measurement value. The results are shown in tables 1 and 2.

(3-2. Full light transmittance)

For each film produced under the above conditions, a haze meter NDH7000 (manufactured by Nippon Denshoku Co., ltd.) was used to determine the basis of JIS K7361-1 at 25 ℃. 1997. The results are shown in tables 1 and 2.

(3-3. Haze)

For each film produced under the above conditions, a haze meter NDH7000 (manufactured by japan electric color industry co., ltd.) was used, and the film was measured at 25 ℃ based on JIS K7136: haze value of 2000. The results are shown in tables 1 and 2.

(3-4. Definition)

The Clarity (CLR) of each film produced under the above conditions was measured by the above measurement method using a Haze-gardi meter (BYK Additives & Instruments company, "Haze-gardi"). The light source used was CIE-D65 light source. The results are shown in tables 1 and 2.

(3-5.60 degree specular gloss)

For each film produced under the above conditions, the film was produced based on JIS Z8741:1997, the 60 DEG specular gloss on the outer surface side of a film containing a vinylidene fluoride resin was measured. The results are shown in tables 1 and 2.

(3-6. Blocking resistance)

For each film produced under the above conditions, 10 A4-version-sized sample films were cut. The cut sample films were overlapped by 10 sheets in the same face-up manner, and a stainless steel plate was placed thereon, and further a weight of 1kg was placed thereon. In this state, the mixture was left at a temperature of 50℃for 24 hours. Then, the weight was removed, and the edge of the uppermost sample film was held by one hand and peeled off in the direction of 90 °. The blocking resistance was evaluated according to the following criteria. The results are shown in tables 1 and 2.

The film was peeled off smoothly with one hand without bringing the film 2 nd and later from above.

The film from the top to the 2 nd can be peeled off without bringing the film up, but the peeling sound is generated.

And (2) taking the film from the top.

(3-7. Chemical resistance)

Each film produced under the above conditions was cut out at a square of 10cm, 5g of a chemical (sun block, trade name: neutrogena Ultra Sheer SPF 45) was applied to one surface of the film (the surface on the film side containing vinylidene fluoride resin in the case of laminating a film containing vinylidene fluoride resin), and after standing at 55 ℃ for 4 hours, the chemical was wiped off to confirm the appearance. Evaluation was performed according to the following criteria. The results are shown in tables 1 and 2.

And (3) the following materials: no change in appearance.

O: a wrinkle is slightly generated.

X: the film is clouded or largely deformed.

< discussion >

(1) Single layer film

In the films of examples 1-1 to 1-4, the composition of the resin constituting the film and the size of the crosslinked (meth) acrylic acid ester-based resin particles were both appropriate, and therefore high transparency (low haze, high clarity) and excellent blocking resistance were obtained.

The film of comparative example 1-1 does not contain crosslinked (meth) acrylate resin particles, and thus has poor blocking resistance.

The films of comparative examples 1-2 to 1-4 contained crosslinked (meth) acrylate resin particles, but were inadequate in size and therefore insufficient in transparency.

(2) Laminated film

In the films of examples 2-1 to 2-13, the composition of the resin constituting the film and the size of the crosslinked (meth) acrylate resin particles were both appropriate, and therefore high transparency and excellent blocking resistance were obtained. Further, by laminating a film containing a vinylidene fluoride resin, chemical resistance is improved as compared with a single-layer film.

The films of comparative examples 2-1 to 2-2 do not contain crosslinked (meth) acrylate resin particles, and therefore have poor blocking resistance.

The films of comparative examples 2-3 to 2-4 contained crosslinked (meth) acrylate resin particles, but the content was inadequate, and therefore the transparency was inadequate.

In the films of comparative examples 2 to 5, the back layer (film containing a methacrylate resin as a main component) contains a vinylidene fluoride resin having a refractive index significantly different from that of the crosslinked (meth) acrylate resin particles, and thus the transparency is insufficient.

The films of comparative examples 2-6 to 2-9 contained crosslinked (meth) acrylate resin particles, but were inadequate in size and therefore insufficient in transparency.

[ Table 1-1]

[ tables 1-2] (Table 1)

[ Table 2-1]

[ Table 2-2] (Table 2)

[ tables 2-3] (Table 2)

[ tables 2-4] (Table 2)

[ tables 2-5] (Table 2)

[ tables 2 to 6]

(subsequent Table 2)

Description of the reference numerals

1. Film and method for producing the same

10. Surface layer

20. Back surface layer

Claims

1. A film containing crosslinked (meth) acrylate resin particles and containing a methacrylate resin as a main component,

the film does not contain vinylidene fluoride resin,

the film is based on JIS K7136: haze measured at 2000 is 5% or less,

the film has a Clarity (CLR) of 97% or more as calculated by the following formula,

CLR＝100×(Ic-Ir)/(Ic+Ir)

2. The film according to claim 1, wherein the amount of the crosslinked (meth) acrylate resin particles is 0.1 parts by mass or more and 2 parts by mass or less based on 100 parts by mass of the methacrylate resin.

3. A laminated film is provided with:

the film of claim 1 or 2, and

4. The laminated film according to claim 3, wherein the film containing a vinylidene fluoride resin contains (a) in a total of 50 to 80 parts by mass and (B) in a total of 20 to 50 parts by mass based on 100 parts by mass of 1 or 2 kinds (a) selected from the group consisting of a copolymer of vinylidene fluoride and hexafluoropropylene and polyvinylidene fluoride, and a methacrylate resin (B).

5. A metal-like decorative film obtained by laminating the film according to claim 1 or 2 as an outermost layer, or a metal-like decorative film obtained by laminating the laminated film according to claim 3 or 4 so that the film containing vinylidene fluoride resin is an outer layer.