CN103765249B - The manufacture method of antireflection film, antireflection film, polarization plates and image display device - Google Patents

Abstract

According to the present invention, there are provided a method for producing an antireflection film, an antireflection film, and an antireflection film capable of easily producing an antireflection film that has excellent antireflection properties, excellent scratch resistance, and antifouling properties, and suppresses the occurrence of slight whitening that has never been dealt with until now. film, and a polarizing plate and an image display device using the film. The present invention provides a method for producing an antireflection film, which sequentially includes the step (1) of applying a composition for forming a low-refractive index layer containing at least a fluorine-containing compound, fine particles, and a binder resin on a transparent substrate to form a coating film. process; process (2) the process of separating the coating film into a low refractive index phase and an antifouling phase; and process (3) heating the low refractive index phase and the antifouling phase, or the low refractive index phase and the antifouling phase The antifouling phase is irradiated with ionizing rays to form a low refractive index layer and an antifouling layer covering the entire surface of the low refractive index layer. The antireflection film has at least a transparent substrate, a low refractive index layer, and an antifouling layer in this order, The fluorine atom/carbon atom ratio measured by X-ray photoelectron spectroscopy (XPS) from the antifouling layer side is 0.6 to 1.0, and the silicon atom/carbon atom ratio is less than 0.25. The average surface roughness (Ra) of the antifouling layer is ') is 10nm or less.

Description

Method for producing antireflection film, antireflection film, polarizing plate, and image display device

technical field

The present invention relates to a method for producing an antireflection film, an antireflection film, a polarizing plate, and an image display device.

Background technique

Conventionally, on the surface of displays such as liquid crystal displays (LCDs), plasma display panels (PDPs), and cathode tube display devices (CRTs), in order to impart high surface hardness or to prevent reflections of light from external light sources such as incandescent lamps and fluorescent lamps, Anti-reflection film is provided for the anti-reflection characteristics. Generally, an antireflection film is a film having a structure in which a hard coat layer and a low-refractive index layer are laminated on a transparent substrate. The low-refractive index layer preferably has a lower refractive index in order to contribute to antireflection. In addition, as a method for realizing low reflectance, for example, it is known to laminate a layer having a higher refractive index such as a medium refractive index layer and a high refractive index layer as a thin film on the above-mentioned hard coat layer, and then form the above-mentioned low-refractive index layer. Methods. Also, for example, Patent Document 1 discloses an antireflection film containing specific fine particles in a refractive index suppressing layer.

On the other hand, as the performance required for the antireflection film, the scratch resistance of the above-mentioned display surface is mentioned, or it is not easy to be soiled by fingerprints, sebum, markers, etc., and it is easy to wipe even if these dirt are attached, that is, Antifouling. As a method of imparting antifouling properties to an antireflection film, there is a method of using an antifouling agent such as a fluorine-containing antifouling agent (for example, Patent Document 1). However, in Patent Document 1, in order to suppress performance degradation caused by cloudiness of the composition containing an antifouling agent, etc., and improve compatibility with each component in the composition, it is necessary to use a low molecular weight antifouling agent with a weight average molecular weight of less than about 5,000. Fluorine-containing antifouling agents cannot be said to have sufficient antifouling properties.

As a method of imparting antifouling properties, it has also been proposed to use a fluorine-containing compound having a perfluoroalkyl group in the antifouling layer provided on the surface, so that in the relationship with silicon, carbon, and fluorine, A method in which a specific amount of fluorine atoms is present (for example, Patent Document 2). It is known that the fluorine-containing compound having a perfluoroalkyl group used in Patent Document 2 is a material excellent in antifouling properties, but has poor compatibility with other materials forming the antifouling layer, such as binder resins, and therefore When a resin composition containing this fluorine-containing compound is applied to form an antifouling layer, it may be difficult to form a stable antifouling layer, or a problem of whitening may occur.

From this point of view, in Patent Document 2, since the miscibility with other components is significantly deteriorated, in order not to cause adverse effects such as dents, unevenness, and whitening on the coated surface, the relationship between the silicon element, the carbon element, and the fluorine element is determined. In , a specific amount of fluorine atoms is present to obtain a certain mutual solubility, thereby forming an antifouling layer, and it is desired to form a stable antifouling layer or suppress the occurrence of whitening (Patent Document 2, paragraph [0039]).

In recent years, along with the improvement in the performance of the above-mentioned displays, the performance of the antireflection film has also been increased, and the demand for whitening has increased in particular. Conventionally, whitening refers to whitening to such an extent that the transparency of the film is reduced that it can be recognized at a glance, and the reduction of such whitening has been pursued. However, in recent years, in addition to the conventional whitening, it is also required to suppress the slight whitening that has never been addressed so far. This slight whitening is to the extent that those skilled in the art can barely recognize it in a film that is considered to have high transparency at first glance. Whitening, according to Patent Document 2, may not fully cope with the coating film surface being not uniform but slightly deformed.

In addition, as a method of imparting antifouling properties to the film, a method of vapor-depositing a silane coupling agent containing a perfluoropolyether group to form an antifouling layer has been proposed on a transparent film substrate provided with an antireflection layer (for example, Patent Document 3 ). The method described in this patent document 3 is difficult to carry out as a resin composition containing a fluorine-containing compound because the above-mentioned fluorine-containing compound having a perfluoroalkyl group or the like has poor compatibility with other materials that usually form an antifouling layer. Coating is used to form an antifouling layer, so a so-called vapor deposition method in which a layer can be formed without using other materials has been attempted, and it is desired to form an antifouling layer containing this fluorine-containing compound into a film. However, since the layer is formed by vapor deposition, other materials such as adhesive resin cannot be used, and since the layer strength of the antifouling layer or the adhesion to the transparent film substrate deteriorates, several times of wiping will cause The antifouling layer is peeled off from the film and the antifouling performance is significantly reduced. Also, because the evaporation must be carried out at a high temperature of several hundred degrees, there is a transparent film substrate that shrinks due to heating, or accelerates the deterioration of the product before distribution. During the test, there were problems such as decomposition of the base material itself that was thermally damaged by high-temperature vapor deposition.

The anti-fouling layer is generally made to be very thin in the order of nm, so that in addition to excellent anti-fouling properties, it is also necessary to suppress the occurrence of slight whitening. In order to meet these conditions at the same time, it can be considered that in addition to using substances that are compatible with each other As a component that forms the anti-fouling layer, further research and development is required to realize it.

[Patent Document 1] Japanese Patent Laid-Open No. 2010-152311

[Patent Document 2] Publication of International Publication No. 2008/38714

[Patent Document 3] Japanese Patent Laid-Open No. 2001-188102

Description of drawings

FIG. 1 is a schematic diagram showing a cross section of an antireflection film of the present invention.

Fig. 2 is a schematic diagram showing a cross section of an antireflection film of the present invention.

Fig. 3 is a schematic diagram showing a cross section of the antireflection film of the present invention.

Fig. 4 is the topography image and phase image obtained by atomic force microscope on the surface of the anti-reflection film obtained in Example 1.

Fig. 5 is the topography image and phase image obtained by atomic force microscope on the surface of the anti-reflection film obtained in Example 2.

Fig. 6 is the topography image and phase image obtained by atomic force microscope on the surface of the anti-reflection film obtained in Example 3.

Fig. 7 is the topography image and phase image obtained by atomic force microscope on the surface of the anti-reflection film obtained in Example 4.

Fig. 8 is the topography image and phase image obtained by atomic force microscope on the surface of the anti-reflection film obtained in Example 5.

FIG. 9 is a topography image and a phase image of the surface of the antireflection film obtained in Comparative Example 1 obtained through an atomic force microscope.

FIG. 10 is a topography image and a phase image of the surface of the antireflection film obtained in Comparative Example 2 obtained through an atomic force microscope.

FIG. 11 is a topography image and a phase image of the surface of the antireflection film obtained in Comparative Example 3 obtained through an atomic force microscope.

Explanation of reference signs

1. Anti-reflection film

2. Transparent substrate

3. Low refractive index layer

4. Hard coating

5. Middle refractive index layer

6. High refractive index layer

7. Medium and high refractive index layer

8. Antifouling layer

Contents of the invention

The technical problem to be solved by the invention

The object of the present invention is to provide an anti-reflection film which has excellent anti-reflection properties, excellent scratch resistance and anti-fouling properties under such circumstances, and which suppresses the occurrence of slight whitening which has never been addressed so far. A method for producing a reflective film, an antireflective film, a polarizing plate and an image display device using the film.

technical means

The inventors of the present invention have repeatedly studied intensively to achieve the above object. As a result, they found that when the antifouling layer is formed according to the method of Patent Document 2, the cured product of the composition for forming the antifouling layer sometimes exists on the surface unevenly, or in a round shape. Or oval-shaped holes exist unevenly, so that the sea-island structure exposed under the base material and the like can be seen. The occurrence of this structure hinders the formation of a stable anti-fouling layer, which in turn leads to slight whitening that has never been investigated. That is, the method disclosed in Patent Document 2 obtains a certain compatibility by making a certain amount of fluorine atoms exist, thereby improving the easiness of forming an antifouling layer, but in the case of pursuing higher performance of the antireflection film Next, there is still room for further research on whether the antifouling layer is formed uniformly, whether a sea-island structure is formed, and whether slight bleaching occurs.

Therefore, the inventors of the present invention have found that instead of seeking to improve the compatibility as in the past, a low-refractive index layer-forming composition containing a specific fluorine-containing compound containing many fluorine atoms with poor compatibility is deliberately used, and a coating is used. By distributing the composition and then separating the phases, a layer is formed so that the entire surface of the film is covered with the composition, so that the formation of sea-island structures as described above is suppressed and the average surface roughness is small and uniform. The low-refractive index layer thus solves the above-mentioned problems.

In addition, although fluorine-containing compounds with a large fluorine atom content are excellent in antifouling properties, they have not been considered to be used in resin compositions due to poor compatibility. However, this fluorine-containing compound can be used in the present invention, and extremely Excellent stain resistance. The present invention has been accomplished based on this knowledge.

That is, the present invention provides:

[1] A method for producing an antireflection film, which sequentially includes the following steps (1) to (3), the antireflection film having at least a transparent base material, a low refractive index layer, and an antifouling layer in sequence, from the antireflection The fluorine atom/carbon atom ratio measured by X-ray photoelectron spectroscopy (XPS) on the contaminated layer side is 0.6 to 1.0, and the silicon atom/carbon atom ratio is less than 0.25. The average surface roughness (Ra') of the antifouling layer is Below 10nm,

Step (1) A step of coating a low-refractive index layer-forming composition containing at least a fluorine-containing compound, fine particles, and a binder resin on a transparent substrate to form a coating film,

Step (2) a step of phase-separating the coating film into a low refractive index phase and an antifouling phase,

Step (3) heating the low refractive index phase and the antifouling phase, or irradiating the low refractive index phase and the antifouling phase with ionizing rays to form a low refractive index layer and an antifouling layer covering the entire surface of the low refractive index layer. Layer process;

[2] An antireflection film produced by the method for producing an antireflection film described in [1] above;

[3] A polarizing plate having an antireflection film on at least one side of the polarizer film, the antireflection film being the antireflection film described in [2] above; and

[4] An image display device having an anti-reflection film or a polarizing plate on the outermost surface of the display, the polarizing plate is a polarizing plate having an anti-reflection film on at least one side of the polarizing film, and the anti-reflection film is The antireflection film described in the above [2].

Invention effect

According to the present invention, it is possible to easily obtain an antireflection film having excellent antireflection characteristics, excellent scratch resistance and antifouling property, and suppressing the occurrence of slight whitening which has never been dealt with until now, and it is possible to obtain an antireflection film using the antireflection film. A polarizing plate of a film, and an image display device.

Detailed ways

[Manufacturing method of anti-reflection film]

The method for producing an antireflection film according to the present invention is a method for producing an antireflection film, which sequentially includes the step (1) coating a low-refractive index layer-forming composition containing at least a fluorine-containing compound, fine particles, and a binder resin on a transparent substrate. material, thereby forming the process of the coating film, process (2) the process of separating the phase of the coating film into a low refractive index phase and an antifouling phase, and process (3) heating the low refractive index phase and the antifouling phase, or The low refractive index phase and the antifouling phase are irradiated with ionizing rays to form a low refractive index layer and an antifouling layer covering the entire surface of the low refractive index layer. The antifouling layer and the antifouling layer, the fluorine atom/carbon atom ratio measured by X-ray photoelectron spectroscopy (XPS) from the antifouling layer side is 0.6 to 1.0, and the silicon atom/carbon atom ratio is less than 0.25, the antifouling layer The average surface roughness (Ra') of the layer is 10 nm or less.

The low-refractive-index phase and the antifouling phase formed in step (2) are phases formed in the coating film formed by applying the composition for forming a low-refractive-index layer. The mixture resin is in an uncured state, and the solvent preferably contained in the composition is in an evaporated state to the extent that phase separation is completed. On the other hand, these phases form a low-refractive index layer and an antifouling layer in which the binder resin in the layer is in a cured state and the solvent evaporates and most of them do not exist through the step (3). Therefore, in the present invention, the state present in the coating film is referred to as a low-refractive index phase and an antifouling phase, and through the step (3), they are respectively referred to as a low-refractive index layer and an antifouling layer. In addition, in the present invention, the uncured state means the state in which the composition for forming a low refractive index layer has physical fluidity, that is, the state in which the viscosity can be measured, and the cured state means that the composition for forming a low refractive index layer does not have physical fluidity. The state of fluidity, that is, the state where the viscosity cannot be measured.

Each step will be described below.

(Process (1))

The step (1) is a coating film forming step of coating a low-refractive index layer-forming composition containing at least a fluorine-containing compound, fine particles, and a binder resin on a transparent substrate to form a coating film.

In the present invention, the coating film forming step is preferably performed by preparing a transparent substrate, separately preparing a composition for forming a low-refractive index layer, and coating the composition for forming a low-refractive index layer on the transparent substrate.

(Preparation of composition for forming low refractive index layer)

The composition for forming a low refractive index layer is obtained by homogeneously mixing the fluorine-containing compound, fine particles, binder resin, and preferably used fluorine-containing polymer or various additives described later, and dissolving it in a solvent if necessary. while preparing.

The composition for forming a low refractive index is preferably liquid dissolved in a solvent in consideration of productivity. The viscosity of the liquid low-refractive index layer-forming composition is not particularly limited as long as a coating film can be formed on the surface of the transparent substrate by the coating method described later.

(formation of coating film)

The coating film is formed on the surface of the transparent base material so that the thickness after curing becomes a predetermined thickness described below. The composition for forming a low refractive index layer prepared as described above is coated by gravure coating or bar coating. Known methods such as cloth, roll coating, reverse roll coating, comma coating, and die coating are preferably applied by gravure coating or die coating.

Hereinafter, each component which forms a transparent base material and the composition for forming a low-refractive-index layer is demonstrated.

(transparent substrate)

The transparent substrate used in the present invention is not particularly limited as long as it is a transparent substance generally used as a substrate of an antireflection film, but it is preferable to appropriately select a plastic film, a plastic sheet, or the like according to the application.

Examples of such a plastic film or plastic sheet include various materials containing synthetic resins. Examples of synthetic resins include polyethylene resins, ethylene alpha olefin copolymers, polypropylene resins, polymethylpentene resins, polybutene resins, ethylene-propylene copolymers, propylene-butene copolymers, olefin-based thermoplastic elastomers Linear or cyclic polyolefin resins such as body, or their mixture; polyethylene terephthalate resin (PET), polybutylene terephthalate resin, polyethylene naphthalate Alcohol ester-isophthalic acid copolymer resin, polyester resin such as polyester thermoplastic elastomer; polymethyl (meth)acrylate resin, polyethyl (meth)acrylate resin, polybutyl (meth)acrylate Acrylic resin such as resin; polyamide resin represented by nylon 6 or nylon 66; triacetyl cellulose resin (TAC), diacetyl cellulose, cellulose acetate butyrate, cellophane and other cellulose Cyclopolyolefin resins obtained from cycloolefins such as norbornene, dicyclopentadiene, and tetracyclododecene; polystyrene resins; polycarbonate resins; polyarylate resins; or polyimides resin etc.

As a transparent substrate, among the above-mentioned plastic film and plastic sheet, it can be used alone or as a mixture of two or more selected ones. From the viewpoint of mechanical strength, polyethylene terephthalate resin or The acrylic resin is preferably triacetylcellulose resin or cyclopolyolefin from the viewpoint of optical anisotropy.

The thickness of the transparent base material is not particularly limited, but is usually about 5 to 1000 μm, preferably 15 to 80 μm, and more preferably 20 to 60 μm in consideration of durability and handleability.

(Composition for forming a low refractive index layer)

The composition for forming a low refractive index layer used in the present invention is a resin composition containing a fluorine-containing compound, fine particles, and a binder resin. Each component will be described below.

(fluorinated compounds)

In order to form an antifouling layer on the antireflection film of the present invention, the composition for forming a low refractive index layer contains a fluorine-containing compound. As the fluorine-containing compound used in the present invention, it is preferably a compound having a reactive group and a perfluoropolyether group. Among them, silane units containing a reactive group and compounds having a perfluoropolyether group are preferably mentioned. Compounds with silane units. In the present invention, since the fluorine-containing compound has a reactive group, it can be easily combined with other components in the composition, thereby forming a stronger layer. As a result, a thinner layer with excellent scratch resistance can be obtained. layer. In addition, in the present invention, the antireflection film having excellent scratch resistance on the outermost surface also means excellent adhesion between the outermost layer and the lower layer. That is, the fluorine-containing compound in the composition for forming a low refractive index layer is present in a larger amount in the low refractive index phase and the antifouling phase, and is cured in the step (3) described later. , the reactive groups contained in the fluorine-containing compounds of the respective phases react with each other, whereby very excellent adhesion between the low refractive index layer and the antifouling layer can be obtained. Furthermore, through the reaction between the reactive group of the fluorine-containing compound and the reactive group of the binder resin, or the curing of the binder resin itself, the adhesion of the antifouling layer is further improved, and the hardness is improved, comprehensively Therefore, it becomes a layer very excellent in scratch resistance.

In addition, since the above-mentioned compound containing a silane unit has an affinity with the fine particles contained in the low refractive index phase, when an antifouling phase is formed on the surface of the low refractive index phase, it can impart wettability over the entire surface of the surface. , and because wettability can be maintained even in a state where the solvent is almost evaporated from the phase, it is important from the viewpoint of obtaining a uniform antifouling layer over the entire surface. Furthermore, since this compound is soft and improves sliding properties, a layer excellent in scratch resistance can be obtained. Furthermore, since wettability can be obtained continuously and stably due to the affinity, it is possible to suppress the occurrence of sinking or formation of sea-island structures when the solvent evaporates, and the occurrence of these slight whitening is also suppressed. Furthermore, by using a fluorine-containing compound having a silane unit and a perfluoroether group in the same molecule, phase separation between the silane unit and the perfluoropolyether can be suppressed, and a more uniform surface can be easily obtained. Here, the silane unit is a unit represented by the following general formula (1).

In formula (1), X represents a single bond or an oxygen atom, R ¹ and R ² represent a monovalent organic group, and at least one of R ¹ and R ² contains a reactive group or a perfluoropolyether group Monovalent organic group. The fluorine-containing compound used in the present invention can be, for example, a silane unit with R being ^a monovalent organic group containing a reactive group, and a silane unit with R being ^a monovalent organic group containing a perfluoropolyether group. The fluorine-containing compound may also be a fluorine-containing compound having a silane unit in which R ¹ is a monovalent organic group including a reactive group, and R ² is a monovalent organic group including a perfluoropolyether group. In addition, in multiple silane units, R ¹ , R ² and X are independent, that is, as long as the fluorine-containing compound of the present invention contains at least silane units with reactive groups and silane units with perfluoropolyether groups, Compounds having a plurality of silane units are then also possible.

In the present invention, these silane units are preferably units having a siloxane skeleton. That is, it is preferable that X in the above formula (1) is an oxygen atom. Since the fluorine-containing compound has a siloxane skeleton, its affinity with the fine particles contained in the above-mentioned low-refractive index layer becomes good, so that a uniform antifouling layer with excellent antifouling properties and less likely to be slightly whitened can be obtained.

The weight average molecular weight of the fluorine-containing compound (the weight average molecular weight of polyethylene as measured by GPC method) is preferably 5,000 or more, more preferably 5,000 to 100,000, and still more preferably 5,000 to 50,000. As long as the weight-average molecular weight of the fluorine-containing compound is above 5,000, excellent antifouling properties can be obtained, and as long as it is below 100,000, good solubility in organic solvents can be obtained, so that it is easy to obtain a uniform surface.

As the reactive group, preferably, a reactive group having an ethylenically unsaturated double bond group such as a (meth)acryloyl group or a vinyl group, or an epoxy group, a carboxyl group, an amino group, a hydroxyl group, etc., among these, A reactive group having an ethylenically unsaturated double bond group such as a (meth)acryloyl group or a vinyl group is preferable. If the reactive group is the above-mentioned group, it can be more easily combined with other components in the composition for forming a low refractive index layer, so that the adhesion between the low refractive index layer and the antifouling layer can be formed as described above. A thin layer with excellent scratch resistance can be obtained, so it is preferable.

As a perfluoropolyether group, the group represented by following general formula (2) is mentioned preferably, for example.

In formula (2), a-e are integers of 0-50, and may be the same or different. It is preferable that ad is an integer which makes the weight average molecular weight of the perfluoropolyether group represented by formula (2) into the range of 200-6000, and e is preferable that it is 0-2. In addition, xa, xb, xc, and xd are integers of 1 to 4, and may be the same or different. When xa, xb, xc and xd are 3 and 4, -C _xa F _2xa , -C _xb F _2xb , -C _xc F _2xc , and -C _xd F _2xd may be linear or branched.

The content of the fluorine atoms in the fluorine-containing compound is preferably 5 to 80 parts by mass, more preferably 10 to 70 parts by mass, and even more preferably 20 to 60 parts by mass. If the content of fluorine atoms in the fluorine-containing compound is 5 parts by mass or more, excellent antifouling properties can be obtained, and if it is 80 parts by mass or less, good solubility in solvents can be obtained, so it is easy to obtain a uniform surface .

Fluorine-containing The solid content of the compound is preferably 5 to 30 parts by mass. In addition, although the fluorine-containing compound, microparticles|fine-particles, and binder resin are commercially available, they are usually sold in the form contained in a solvent. At this time, the amount of these solid components is the amount obtained by subtracting the solvent from the total amount of a commercial product. In addition, for example, although a photopolymerization initiator is one of the arbitrary solid components contained in a composition, it is not included when calculating the content of a fluorine-containing compound.

If the content of the fluorine-containing compound is more than 5 parts by mass, the entire surface can be covered with a uniform antifouling layer with the fluorine-containing compound, so there will be no sea-island structure and slight whitening. In addition, if it is 30 parts by mass or less, the roughness of the coating film surface such as unevenness and unevenness of the coating film surface will not occur, and a uniform antifouling layer can be obtained, and slight whitening will not occur, and excellent abrasion resistance can be obtained. hurtful. That is, by setting the content of the fluorine-containing compound within the above range, a uniform and smooth antifouling layer having an average surface roughness (Ra') of 10 nm or less can be obtained.

From the same reasons as above, the content of the fluorine-containing compound is more preferably 5 to 20 parts by mass, more preferably 5 to 15 parts by mass, and still more preferably 10 parts by mass as the maximum content. By setting the maximum content to 10 parts by mass, the average surface roughness (Ra') described later can be further reduced to 5 nm or less, resulting in a smoother surface and good scratch resistance.

(particle)

The composition for forming a low refractive index layer contains fine particles. Fine particles are used to lower the refractive index of the layer, that is, to improve antireflection characteristics.

Any of inorganic and organic particles can be used without limitation. From the viewpoint of further improving the anti-reflection characteristics and ensuring good surface hardness, from the viewpoint of material, preferably carbon dioxide Silicon microparticles, magnesium fluoride microparticles, and the like are preferably spherical and have voids in themselves from the viewpoint of shape. In addition, when there are voids, generally, alumina fine particles having a higher refractive index than the cured film of the binder resin can be used.

Among these, from the viewpoint of material, silica fine particles are preferable in consideration of durability against wet heat and the like. In the present invention, in order to form the antifouling layer covering the entire surface of the low refractive index layer, the combination of materials forming these layers is one of the important conditions. Since the fine particles are present in a state of being densely packed substantially throughout the entire surface of the low refractive index layer, the properties of the surface of the low refractive index layer tend to be affected by the fine particles. The higher the affinity between the fine particles contained in the low refractive index layer and the material forming the antifouling layer, the easier it is to form the antifouling layer so as to cover the entire surface of the low refractive index layer. This is because, when the antifouling phase is phase-separated from the low refractive index phase, the antifouling phase becomes wettable over the entire surface of the low refractive index phase and remains wettable until step (3) is completed. From this point of view, it is particularly preferable that the microparticles are silica microparticles made of silica as a material, and the fluorine-containing compound is a combination of a silane unit, and further a fluorine-containing compound containing a silicon atom having a siloxane unit.

Microparticles that have voids themselves have microscopic voids on the outside or inside, and are filled with gas such as air having a refractive index of 1.0, and thus have a characteristic of low refractive index. Such microparticles having voids include inorganic or organic porous microparticles, hollow microparticles, and the like, for example, preferably porous silica, hollow silica microparticles, or porous microparticles using acrylic resin or the like. polymer particles or hollow polymer particles. As inorganic microparticles, silicon dioxide microparticles having voids prepared by the technique disclosed in JP-A-2001-233611 can be cited as a preferred example; - Hollow polymer particles prepared by the technique disclosed in Publication No. 80503 are preferred examples.

The above-mentioned silica with voids or porous silica has a refractive index of about 1.20 to 1.44. Since the refractive index is lower than that of ordinary silica particles with a refractive index of about 1.45, the low refractive index layer It is preferable from the viewpoint of lowering the refractive index.

In addition, fine particles that can form a nanoporous structure inside and/or at least a part of the surface based on their morphology, structure, aggregation state, and dispersion state inside the membrane are also preferable.

Examples of such fine particles include the above-mentioned silica fine particles, or slow-release materials manufactured for the purpose of increasing the specific surface area and absorbing various chemical substances in the porous part of the filling column and the surface, used for Porous fine particles for immobilizing catalysts, or dispersions or aggregates of hollow fine particles for the purpose of heat insulating materials or low dielectric materials, etc. Specific examples include "NIPSIL (trade name)" and "NIPGEL (trade name)": manufactured by Nippon Silica Industry Co., Ltd.; or "COLLOID SILICAUP series (trade name)": Nissan Chemical Industries, Ltd., etc. .

The average particle diameter of the primary particles of the microparticles is preferably 5 to 200 nm, more preferably 5 to 100 nm, and even more preferably 10 to 80 nm. When the average particle size of the fine particles is 5 nm or more, an excellent refractive index lowering effect can be obtained, and if it is 200 nm or less, a good dispersion state of the fine particles can be obtained without impairing the transparency of the low refractive index layer 3 . In addition, in the present invention, as long as the average particle diameter is within the above-mentioned range, fine particles may be connected to form a chain. Here, the average particle diameter of the primary particles of the microparticles is to use a transmission electron microscope (TEM) to observe the section of the anti-reflection film in any three fields of view, and to actually measure any 20 particles present in the section on the photograph ( The diameter of the total of 60 particles in the three visual fields) is taken as the average particle diameter.

In addition, the fine particles used in the present invention are preferably surface-treated fine particles. As surface treatment, surface treatment using a silane coupling agent is preferably mentioned, and among them, surface treatment using a silane coupling agent which has a (meth)acryloyl group is preferable. By surface-treating the particles, the affinity with the binder resin described later is increased, the dispersion of the particles becomes uniform, and the aggregation of the particles is less likely to occur, so it is possible to suppress the transparency of the low-refractive index layer due to large particles. decrease in coating performance of the composition for forming a low-refractive index layer, or decrease in coating film strength of the composition. In addition, when the silane coupling agent has a (meth)acryloyl group, since the silane coupling agent has ionizing radiation curability, it is easy to react with the binder resin described later. In the coating film of the object, the fine particles are fixed by the binder resin. That is, the fine particles function as a crosslinking agent in the binder resin. Thereby, the tension effect of the entire coating film can be obtained, and the binder resin can directly impart excellent surface hardness to the low-refractive index layer while retaining its original flexibility. Therefore, the low-refractive index layer deforms by exerting its own flexibility, thereby having absorbing force or restoring force against external impacts, and thus suppresses the occurrence of scratches, and becomes a layer having a high surface hardness with excellent scratch resistance.

As the silane coupling agent preferably used in the present invention, 3-(meth)acryloxypropyltrimethoxysilane, 3-(meth)acryloxypropyltriethoxysilane, 3 -(meth)acryloxypropylmethyldimethoxysilane, 3-(meth)acryloxypropylmethyldiethoxysilane, 2-(meth)acryloxypropyl Trimethoxysilane, 2-(meth)acryloyloxypropyltriethoxysilane, etc.

The content of fine particles in the low refractive index layer is preferably 10 to 95% by mass, more preferably 20 to 90% by mass, and still more preferably 30 to 90% by mass. Here, the content of fine particles in the low refractive index layer is the total solid content of the composition for the low refractive index layer, that is, on top of the fluorine-containing compound, fine particles, and binder resin, plus any optional fluorine-containing The content of fine particles in the total amount of additives such as polymers, fluorine-containing monomers, and polymerization initiators (the total amount of all compounds contained in the composition except the solvent) has the same meaning. If the content of the fine particles is 10% by mass or more, the effect of using the above-mentioned fine particles can be sufficiently obtained, and if it is 95% or less, the average surface roughness (Ra') of the antifouling layer can be reduced, and the gap between the fine particles can be closed by the resin. The space is well filled and leveled, resulting in excellent surface hardness.

In addition, in the present invention, for the purpose of improving scratch resistance, solid fine particles having no voids may be used together. The average particle diameter of the primary particles of the solid fine particles is preferably 1 to 200 nm, more preferably 1 to 100 nm, and even more preferably 5 to 20 nm. If it is 1 nm or less, the contribution to improvement of the surface hardness is small, and if it is 200 nm or more, the transparency of the low-refractive index layer will be impaired, making it difficult to obtain a good particle dispersion state.

The content of the solid particles may be appropriately adjusted in accordance with the scratch resistance, refractive index, and the like required for the low-refractive index layer. For example, it is preferably 1 to 30% by mass, more preferably 5 to 20% by mass based on the total mass of the total solid content of the composition for a low refractive index layer.

From the viewpoint of scratch resistance and transparency, it is desirable to perform surface treatment similarly to the fine particles having voids described above.

As the solid particles, conventionally known solid particles used in antireflection films, hard coats, and the like can be used. As commercially available products, for example, Nissan Chemical Industry Co., Ltd. product names MIBK-ST (average primary particle size: 12nm) and MIBK-ST-ZL (average primary particle size: 88nm), or Nissan Chemical Co., Ltd. Kasei Kogyo Co., Ltd. product name OSCAL series (average primary particle diameter: 7 to 100 nm) and the like.

(Binder resin)

The composition for forming a low-refractive index layer contains a binder resin from the viewpoints of film-forming property and film strength. As the binder resin, it is preferable to use heating or irradiation of ultraviolet rays, ionizing rays such as electron beams, etc. to cure, so that the above-mentioned fluorine-containing compounds, fine particles, other components added as needed, etc. Immobilized resin in layer by layer. In addition, in the present invention, a resin having low compatibility with the fluorine-containing compound is preferable so that the above-mentioned fluorine-containing compound can be phase-separated efficiently to obtain an antifouling layer completely covering the low-refractive index layer.

More specifically, as the binder resin, for example, thermosetting resins such as melamine-based, urea-based, epoxy-based, ketone-based, diallyl phthalate-based, unsaturated polyester-based, and phenol-based are preferably used. , or ionizing radiation curable resin. Among them, ionizing radiation curable resins are preferable.

The so-called ionizing radiation curable resin is a resin that has energy quanta that can polymerize molecules in electromagnetic waves or charged particle beams, that is, a resin that is cured by irradiation with ultraviolet rays or electron beams. Specifically, it can be appropriately selected from polymerizable monomers and polymerizable oligomers (or prepolymers) conventionally used as ionizing radiation curable resins.

As the polymerizable monomer, a (meth)acrylate monomer having a radically polymerizable unsaturated group in the molecule is suitable, and among them, a polyfunctional (meth)acrylate monomer is preferable.

The polyfunctional (meth)acrylate monomer is not particularly limited as long as it is a (meth)acrylate monomer having two or more ethylenically unsaturated bonds in the molecule. Specifically, preferably, ethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, pentaerythritol di(meth)acrylate monostearate, dicyclopentene di(meth)acrylate Bifunctional (meth)acrylates such as esters and isocyanurate di(meth)acrylates; trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, tri(propylene Trifunctional (meth)acrylates such as acyloxyethyl)isocyanurate; pentaerythritol tetra(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate , dipentaerythritol hexa(meth)acrylate and other tetrafunctional (meth)acrylates; ethylene oxide modified products and caprolactone modified products of the above-mentioned polyfunctional (meth)acrylate monomers, Propionic acid modified products, etc.

Among these, trifunctional or more functional (meth)acrylates are preferable from the viewpoint that excellent scratch resistance can be obtained. These polyfunctional (meth)acrylate monomers may be used alone or in combination of two or more. More specifically, in the present invention, it is possible to suitably obtain effect substances such as antifouling property, scratch resistance (adhesion), light whitening resistance, etc., and trimethylolpropane tri(meth)acrylate is preferable , pentaerythritol tri(meth)acrylate, tri(acryloyloxyethyl)isocyanurate and other trifunctional (meth)acrylates; pentaerythritol tetra(meth)acrylate, dipentaerythritol tetra(meth)acrylate ) acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate and other tetrafunctional (meth)acrylates, particularly preferably pentaerythritol tri(meth)acrylate.

In the present invention, in addition to using the above polyfunctional (meth)acrylate monomer, in order to reduce its viscosity, etc., a monofunctional (meth)acrylate monomer may be used in combination as appropriate within the range that does not impair the object of the present invention. monomer. In addition, in order to properly adjust coating by increasing viscosity and prevent warpage due to cure shrinkage, the following polymerizable oligomers or polymers may be used.

Hereinafter, examples of polymerizable oligomers include oligomers having radically polymerizable unsaturated groups in the molecule, such as epoxy (meth)acrylate-based, urethane (meth)acrylate-based, Polyester (meth)acrylate-based, polyether (meth)acrylate-based oligomers, etc.

In addition, in the present invention, for example, a reactive resin obtained by prepolymerizing methyl methacrylate and glycidyl methacrylate to obtain a copolymer, and then condensing the glycidyl group of the copolymer with the carboxyl group of methacrylic acid or acrylic acid can also be used. polymer. Such a reactive polymer can be obtained as a commercial item, and examples of the commercial item include "MACROMONOMER (trade name)": manufactured by Toagosei Co., Ltd., and the like.

In the present invention, an ultraviolet curable resin or an electron beam curable resin can be preferably used as the ionizing radiation curable resin.

When using an ultraviolet curable resin as an ionizing radiation curable resin, it is preferable to add about 0.5-10 mass parts of photoinitiators with respect to 100 mass parts of this ultraviolet curable resin, and it is more preferable to add 1-5 mass parts. As the photopolymerization initiator, it can be appropriately selected from conventional ones without particular limitation. For example, for polymerizable monomers or polymerizable oligomers having a radically polymerizable unsaturated group in the molecule, benzene Ethanone-based, benzophenone-based, benzoin-based, ketal-based, anthraquinone-based, disulfide-based, thioxanthone-based, thiram-based, fluoroamine-based, and other photopolymerization initiators. These may be used alone or in combination of two. These photopolymerization initiators are commercially available, and examples thereof include "IRGACURE 184 (trade name)", "IRGACURE 907 (trade name)" and "IRGACURE 127 (trade name)" (both manufactured by Ciba Specialty Chemicals Co., Ltd.) wait.

The content of the binder resin is preferably 0.5 to 20 parts by mass, more preferably 1 to 15 parts by mass, based on 100 parts by mass of the total solids in the composition for forming a low refractive index layer. When the content of the binder resin is within the above range, excellent scratch resistance can be obtained, and the fluorine-containing compound can be phase-separated efficiently.

(fluoropolymer)

From the viewpoint of lowering the refractive index, the composition for forming a low-refractive index layer used in the present invention preferably contains a fluoropolymer. As fluoropolymers, for example, partially and fully fluorinated alkyl, alkenyl, and aryl esters of (meth)acrylic acid, fully or partially fluorinated vinyl ethers, fully or partially fluorinated vinyl Esters, fully or partially fluorinated vinyl ketones, etc.

Moreover, as a fluorine-containing polymer, what contains silicon other than fluorine is preferable, For example, the silicone containing vinylidene fluoride copolymer which contains a silicone component in a copolymer is mentioned preferably. Examples of silicone components in this case include (poly)dimethylsiloxane, (poly)diethylsiloxane, (poly)diphenylsiloxane, (poly)methylphenylsiloxane Oxane, alkyl modified (poly) dimethyl siloxane, azo-containing (poly) dimethyl siloxane, or dimethyl silicone, phenyl methyl silicone, alkyl aromatic Alkyl-modified silicone, fluorosilicone, polyether-modified silicone, fatty acid ester-modified silicone, methylhydrogenated silicone, silanol-containing silicone, alkoxy-containing silicone, phenol-containing Based silicone, methacryl-modified silicone, acryl-modified silicone, amino-modified silicone, carboxylic acid-modified silicone, methanol-modified silicone, epoxy-modified silicone, mercapto-modified Silicone, fluorine-modified silicone, polyether-modified silicone, etc. Among them, those having a dimethylsiloxane structure are preferable.

In addition, in addition to the above, a compound having at least one isocyanate group and fluorine in the molecule can also be used. Compounds obtained by reacting with compounds having at least one functional group that reacts with isocyanate groups such as amino, hydroxyl, and carboxyl groups in the molecule; fluorine-containing Fluorine-containing polyols such as polyether polyols, fluorine-containing alkyl polyols, fluorine-containing polyester polyols, fluorine-containing ε-caprolactone-modified polyols, and compounds obtained by reacting compounds with isocyanate groups are used as fluorine-containing polyols. polymer.

The refractive index of the fluoropolymer is preferably 1.37 to 1.45. When the refractive index is 1.37 or more, since good solubility in a solvent is obtained, handling is easy. Moreover, if it is 1.45 or less, the refractive index of the formed low-refractive-index layer can be reduced to a desired range.

Such fluorine-containing polymers can be obtained as commercial products, and examples thereof preferably include OPSTARTU2181-6, OPSTARTU2181-7, OPSTARTU2202, OPSTARJN35, OPSTARTU2224 manufactured by JSR Corporation, OPTOOLAR110 and OPTOOLAR100 manufactured by DAIKIN INDUSTRIAL CO., LTD.

The content of the fluoropolymer is preferably 1 to 30 parts by mass, more preferably 5 to 25 parts by mass, based on 100 parts by mass of the total solids in the composition for forming a low refractive index layer. When the content of the fluorine-containing polymer is within the above range, the refractive index can be efficiently lowered.

(fluorinated monomer)

From the viewpoint of lowering the refractive index, the composition for forming a low-refractive index layer used in the present invention preferably contains a fluorine-containing monomer. The fluorine-containing monomer preferably has two or more reactive functional groups in one molecule from the viewpoint of efficiently curing to form a low-refractive index layer and obtaining excellent hardness. Examples of such fluorine-containing monomers include preferably fluorine-containing monomers having a pentaerythritol skeleton, fluorine-containing monomers having a dipentaerythritol skeleton, fluorine-containing monomers having a trimethylolpropane skeleton, and fluorine-containing monomers having a cyclohexyl skeleton. Fluorine monomers, fluorine-containing monomers having a linear skeleton, and the like. Among these, compounds having a pentaerythritol skeleton are preferable.

The refractive index of the fluorine-containing monomer is preferably 1.35 to 1.48, more preferably 1.37 to 1.45. When the refractive index of the fluorine-containing monomer is 1.35 or more, good solubility in solvents can be obtained, so handling is easy. Moreover, if it is 1.48 or less, the refractive index of the formed low-refractive-index layer can be reduced to a desired range.

Such a fluorine-containing monomer can be obtained as a commercial product, for example, LINC series such as LINC3A having a pentaerythritol skeleton and LINC102A having a cyclohexyl skeleton manufactured by Kyoeisha Chemical Co., Ltd. are preferable.

The content of the fluorine-containing monomer is preferably 1 to 30 parts by mass, more preferably 3 to 20 parts by mass, based on 100 parts by mass of the total solids in the composition for forming a low refractive index layer. When the content of the fluorine-containing monomer is within the above range, the refractive index can be effectively lowered.

(various additives)

In the composition for forming a low-refractive index layer used in the present invention, various additives can be blended according to desired physical properties. As additives, for example, preferably, weather resistance improving agents, abrasion resistance improving agents, polymerization inhibitors, crosslinking agents, infrared absorbers, adhesion improving agents, antioxidants, leveling agents, thixotropy imparting agents, Coupling agent, plasticizer, defoamer, filler, solvent, etc.

(solvent)

In addition, the solvent preferably used in the composition for forming a low refractive index layer is not particularly limited, but for example, preferably alcohols such as methanol, ethanol, and isopropanol (IPA); methyl ethyl ketone, methyl alcohol, etc.; ketones such as isobutyl ketone and cyclohexanone; esters such as ethyl acetate and butyl acetate; halogenated hydrocarbons; aromatic hydrocarbons such as toluene and xylene; propylene glycol monomethyl ether, propylene glycol monoethyl ether, Glycol ethers such as propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, dipropylene glycol monoethyl ether, or mixtures thereof. Among these, ketones and glycol ethers with high affinity to fluorine-containing compounds are preferred, and particularly preferred solvents are methyl ethyl ketone, methyl isobutyl ketone, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol Monomethyl ether acetate, Propylene glycol monoethyl ether acetate. By using these alone or in combination, the dispersibility of each compound in the composition can be maintained, and phase separation of the low refractive index phase and the antifouling phase can be completed suitably in the phase separation step (2).

Furthermore, when solvents other than ketones or glycol ethers are used, it is preferable to contain ketones or glycol ethers at least 50% or more, preferably 70% or more, of the total solvent amount. Especially in the case of using ketones, since the applicability of the composition for forming a low-refractive index layer is improved, and the evaporation rate of the solvent after coating of the composition is moderate, uneven drying is less likely to occur. In addition, it may be accompanied by Evaporation of the solvent effectively separates the phases of the fluorine-containing compounds, so a uniform and large-area coating film (anti-fouling layer) can be easily obtained.

The amount of the solvent is appropriately adjusted so that each component can be uniformly dissolved and dispersed, and the composition does not aggregate during storage after preparation and does not become too thin when applied. The content of the solvent in the composition for forming a low-refractive index layer is preferably 50 to 99.5% by mass, preferably 70 to 98% by mass. By setting it as such content, the composition which is excellent especially in dispersion stability and is suitable for long-term storage can be obtained. In addition, the solvent used in the composition for forming a low-refractive index layer hardly exists in the low-refractive index layer because it evaporates by drying or curing performed after coating the composition.

(Process (2))

Step (2) is a step of phase-separating the coating film formed in the above step (1) into a low refractive index phase and an antifouling phase. As a method for promoting phase separation, heating methods such as a method of heating the coating film in air, a method of holding it in steam or in an autoclave, etc. are preferable, for example. In addition, heating etc. may not be performed, and you may simply leave until phase separation.

In the present invention, after applying the composition for forming a low-refractive index layer and before curing the binder resin in the composition, in this step, by heating as described above or simply leaving it alone, the The fluorine-containing compound tends to float on the outermost side of the coating film (the side opposite to the transparent substrate). As a result, in the coating film of the composition for forming a low refractive index layer, the phase separates into an antifouling phase that exhibits antifouling properties due to a relatively large content of the fluorine-containing compound, and exhibits a low refractive index due to a relatively small content of the fluorine-containing compound. The antifouling layer is formed by heating the antifouling phase formed on the outermost surface side or irradiating ionizing rays to form an antifouling layer covering the entire surface of the low refractive index layer, thereby obtaining excellent antifouling properties. Pollution. That is, in the present invention, when the composition for forming a low refractive index layer is applied to form a coating film, two phases are separated in the coating film, and the coating film has a low refractive index phase and an antifouling phase. Step (3), the two phases respectively form a low refractive index layer and an antifouling layer, and in other words, it can also be said that a low refractive index layer with an antifouling layer is formed.

The time for the above-mentioned heating or simply leaving is only required as long as the fluorine-containing compound floats to the outermost surface side of the coating film, and is usually about 1 to 30 seconds.

In addition, the solvent preferably contained in the composition for forming a low-refractive index layer may be evaporated by heating as described above or simply left alone, and the solvent may be actively dried for the purpose of evaporating the solvent. The drying temperature conditions in this case are preferably in the range of 20 to 120°C, more preferably 40 to 100°C, and the drying time is preferably 10 to 180 seconds, more preferably 15 to 90 seconds. The upper limit temperature of drying temperature can be selected suitably according to the material of the transparent base material used. On the other hand, from the viewpoint of quickly and surely phase-separating the fluorine-containing compound on the outermost surface to form an antifouling layer, the lower limit temperature is suitably selected to be 20°C. In addition, from the viewpoint of separating the antifouling phase after stabilization to form an antifouling layer, it is more preferably set at 40° C. or higher.

(Process (3))

Step (3) is a step of heating the phase-separated coating film or irradiating the coating film with ionizing rays to make the low refractive index phase and the antifouling phase in the coating film a low refractive index layer and an antifouling layer, respectively. Here, the low refractive index layer is a layer having antireflection properties due to the presence of fine particles in the layer, and the antifouling layer is a layer having antifouling properties due to the presence of a fluorine-containing compound in the layer. In this specification, for the sake of convenience, a layer containing less fluorine-containing compounds is called a low-refractive-index layer (a low-refractive-index phase before heating or irradiating ionizing rays) because it is relatively superior in antireflection properties. The layer containing more fluorine-containing compounds has better antifouling properties, so it is called antifouling layer (it is antifouling phase before heating or irradiating ionizing rays).

Whether to heat or irradiate the coating film with ionizing rays is selected depending on the binder resin contained in the composition for forming a low refractive index layer. When a thermosetting resin is used as the binder resin, a heating step is selected. As a heating condition, it can suitably set according to the hardening temperature of the thermosetting resin used, for example, it can set it as 60-100 degreeC.

In addition, when an ionizing radiation-curable resin is used as the binder resin, the coating film may be irradiated with ionizing radiation. When curing the above-mentioned coating film, when electron beams are used as ionizing rays, the accelerating voltage can be appropriately selected according to the resin used or the thickness of the layer. Usually, it is preferable to cure the coating film at an accelerating voltage of about 70 to 300 kV.

In addition, in the irradiation of electron beams, since the higher the acceleration voltage, the higher the penetration ability is, the greater the penetration ability is. In the case of using a substrate that is degraded by the electron beams as the substrate, by setting the penetration depth of the electron beams and the thickness of the coating film to be Selecting the acceleration voltage in a substantially equal manner can suppress excess irradiation of the electron beam on the substrate, and can control the deterioration of the substrate caused by excessive electron beams to a minimum.

The irradiation dose is preferably an amount to saturate the crosslinking density of the curable resin in the low refractive index layer, usually 5 to 300 kGy (0.5 to 30 Mrad), more preferably selected in the range of 10 to 50 kGy (1 to 5 Mrad). .

In addition, the electron beam source is not particularly limited, and for example, Kerklauf-Walton type, Van de Graaff type, resonant transformer type, insulating core transformer type, or linear type, Dynamitron type, and high frequency type can be used. and other electron beam accelerators.

When ultraviolet rays are used as ionizing rays, for example, ultraviolet rays emitted from ultrahigh pressure mercury lamps, high pressure mercury lamps, low pressure mercury lamps, carbon arc lamps, xenon arc lamps, metal halide lamps and the like are used. The irradiation dose of the energy ray source is preferably about 50 to 500 mJ/cm ² in terms of cumulative exposure dose at an ultraviolet wavelength of 365 nm.

From the viewpoint of preventing oxygen barrier on the surface of the resin composition for a low-refractive index layer, irradiation of ultraviolet rays is preferably performed under a nitrogen atmosphere, for example, an atmosphere having an oxygen concentration of 1000 ppm or less. In the present invention, after phase separation, ultraviolet irradiation is most preferable from the viewpoint of stably and rapidly curing the low-refractive-index phase and the antifouling phase.

In addition, by curing in the step (3), the solvent is almost completely evaporated and dried, and hardly exists in the layer. The solvent has been substantially evaporated in the step (2), and the solvent remaining in the layer when the step (2) is completed is considered to be almost completely evaporated in the step (3).

[Anti-reflection film]

The antireflection film of the present invention is obtained according to the above-mentioned production method of the present invention, and more specifically, it is characterized in that it has at least a transparent base material, a low refractive index layer, and an antifouling layer covering the entire surface of the low refractive index layer in this order. , the low refractive index layer and the antifouling layer are formed using a composition for forming a low refractive index layer containing a fluorine-containing compound, microparticles and a binder resin, and the X-ray photoelectron spectroscopy (XPS ) measured fluorine atom/carbon atom ratio is 0.6-1.0, and silicon atom/carbon atom ratio is less than 0.25, and the average surface roughness (Ra') of the antifouling layer is 10nm or less.

The antireflection film of the present invention will be described using FIGS. 1 to 3 . 1 is a schematic view showing a cross section of the antireflection film of the present invention, and FIGS. 2 and 3 are schematic views showing the cross section of a preferred layer configuration of the antireflection film of the present invention as an example. The antireflection film 1 shown in FIG. 1 has a low refractive index layer 3 and an antifouling layer 8 on a transparent substrate 2 . The anti-reflection film 1 shown in Fig. 2 has hard coat layer 4, middle and high refractive index layer 7, and low refractive index layer 3 successively on transparent base material 2, and the anti-reflection film 1 shown in Fig. 3 is on transparent base material The material 2 has a hard coat layer 4, a medium refractive index layer 5, a high refractive index layer 6, a low refractive index layer 3, and an antifouling layer 8 in sequence. The layer constitution of the antireflection film 1 of the present invention is not particularly limited as long as it has the low-refractive-index layer 3 and the anti-fouling layer 8 on the transparent substrate 2 in this order. For example, a transparent substrate/low-refractive-index layer is preferable. / Antifouling layer, transparent base material / hard coat layer / low refractive index layer / antifouling layer, transparent base material / hard coat layer / medium refractive index layer / high refractive index layer / low refractive index layer / antifouling layer, transparent Substrate/hard coat layer/high refractive index layer/medium refractive index layer/low refractive index layer/antifouling layer, transparent substrate/medium and high refractive index layer/low refractive index layer/antifouling layer and other layers. In addition, although not shown in the figure, it may further have functional layers such as an antistatic layer described later on the side closer to the transparent substrate than the low-refractive index layer.

(low refractive index layer 3 and antifouling layer 8)

The low-refractive-index layer 3 and the antifouling layer 8 are layers formed using a low-refractive-index layer-forming composition containing a fluorine-containing compound, fine particles, and a binder resin. These layers are layers formed according to the above-mentioned method for producing an antireflection film of the present invention, that is, a coating film is formed by coating the composition for forming a low refractive index layer on a transparent substrate, and the coating film is phase-separated, as Two phases in the coating film form a low refractive index phase and an antifouling phase, and these coating films are heated or irradiated with ionizing rays to form layers serving as the low refractive index layer 3 and the antifouling layer 8 , respectively. Moreover, the content of the fluorine-containing compound contained in the low refractive index layer 3 is relatively smaller than the content of the fluorine-containing compound contained in the antifouling layer 8, and conversely, the content of the fluorine-containing compound is relatively large. The antifouling layer 8 having many is a layer which expresses strong antifouling property.

(low refractive index layer 3)

As for the low refractive index layer 3, when the refractive index of the layer provided directly below is N and the refractive index of air is 1, it is most preferable that the refractive index is N ^1/2 , for example, When the layer directly below the low refractive index layer 3 is a hard coat layer formed using a widely used polyfunctional (meth)acrylic ionizing radiation curable resin, it is considered that the N of the hard coat layer is 1.49 to 1.53 , it is preferably a layer having a refractive index lower than N by 0.01 from 1.48 to 1.52. In addition, the lower the refractive index is, the more desirable it is, but in consideration of the balance between antireflection characteristics and surface hardness, it is more preferably 1.25 to 1.45, and even more preferably 1.25 to 1.35. The refractive index can be easily controlled by the type and content of the fine particles, or the amount of the fluorine-containing compound used.

In addition, in order to obtain the best antireflection effect, it is preferable that the film thickness and the refractive index of the low refractive index layer 3 satisfy the relationship calculated from the following formula (I).

d _A =mλ/(4n _A )(I)

In formula (I), n _A represents the refractive index of the low refractive index layer, m represents a positive odd number, preferably 1 (air), and λ represents a wavelength, preferably a value in the range of 480 to 580 nm. Therefore, in the present invention, from the viewpoint of lowering the refractive index, when m=1 in the above formula (I) and λ is 480 to 580 nm, which is the most dazzling wavelength felt by humans, it is preferable to use the following formula (II) ) calculated refractive index and film thickness.

120<n _A d _A <145(II)

When the refractive index is within the preferred range of 1.25 to 1.45 as described above, the film thickness is preferably about 80 nm to 120 nm. However, in order to obtain an anti-reflection effect by making the refractive index lower than that of the lower layer, the film thickness may be about 120 nm to 1 μm, which exceeds this range. In the present invention, it is preferable that the total thickness of the low-refractive index layer and the antifouling layer is within the above range.

(anti-fouling layer 8)

The antifouling layer 8 is a layer having an average surface roughness (Ra') of 10 nm or less, uniformly covering the entire surface of the low refractive index layer 3, and imparting antifouling properties to the antireflection film of the present invention.

The antifouling layer 8 is a layer having an average surface roughness (Ra') of 10 nm or less, and is a uniform layer. In addition, the average surface roughness (Ra') of the antifouling layer 8 is preferably 0.1 to 10 nm, more preferably 0.1 to 7 nm, and still more preferably 0.1 to 5 nm where scratch resistance is maximized. Here, the average surface roughness (Ra') is a value obtained by applying the centerline average roughness (Ra) defined in JISB0601 to the measurement surface and performing a three-dimensional expansion, expressed as "the average surface roughness (Ra) from the reference surface to the specified surface. The absolute value of the deviation takes the average value", which is the value improved by the following formula. For example, the average surface roughness (Ra') may be obtained as long as the surface shape can be observed with an atomic force microscope (AFM), and the resulting image can be analyzed using accompanying analysis software (such as SPIwin, etc.).

$\mathrm{<span\; class="notranslate">\; R</span>}{\mathrm{<span\; class="notranslate">\; a</span>}}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{{\mathrm{<span\; class="notranslate">\; S</span>}}_{\mathrm{<span\; class="notranslate">\; o</span>}}}{<span\; class="notranslate">\; \&Integral;</span>}_{{\mathrm{<span\; class="notranslate">\; Y</span>}}_{\mathrm{<span\; class="notranslate">\; B</span>}}}^{{\mathrm{<span\; class="notranslate">\; Y</span>}}_{\mathrm{<span\; class="notranslate">\; T</span>}}}{<span\; class="notranslate">\; \&Integral;</span>}_{{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; L</span>}}}^{{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; R</span>}}}<span\; class="notranslate">\; |</span>\mathrm{<span\; class="notranslate">\; f</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; x</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; Y</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; Z</span>}}_{\mathrm{<span\; class="notranslate">\; o</span>}}<span\; class="notranslate">\; |</span>\mathrm{<span\; class="notranslate">\; wxya</span>}$

Ra': average surface roughness (nm)

S _o : Assuming that the measuring surface is ideally flat (|X _R -X _L |×|Y _T -T _B |)

F(X,Y): the height at the measuring point (X,Y)

X: X coordinate

Y: Y coordinate

X _L ,～X _R : The range of the X coordinate of the measurement surface

Y _B ～Y _T : Range of Y coordinates of the measurement surface

Z _o : Average height within the measurement plane

Since the average surface roughness of the anti-fouling layer 8 is very small and uniform as described above, it has excellent scratch resistance and anti-fouling properties, and also has excellent anti-reflection properties, so it is preferably arranged on the anti-reflection layer of the present invention. the outermost surface of the membrane.

The uniform state of the antifouling layer 8 can be specifically confirmed not only by the average surface roughness (Ra'), but also by atomic force microscope (AFM) observation. That is, when the antifouling layer 8 is observed with an atomic force microscope (AFM), in its topography and phase images, the cured product of the composition for forming a low-refractive index layer does not exist unevenly, or the cured product formed by the cured product does not exist. There are circular or elliptical holes unevenly in the anti-fouling layer, and the lower layer such as the low-refractive index layer or the transparent substrate is exposed, that is, the sea-island structure does not occur, and the entire surface of the anti-reflection film 1 is reached. state of formation.

The fluorine atom/carbon atom ratio measured by X-ray photoelectron spectroscopy (XPS) from the antifouling layer side is 0.6 to 1.0, and the silicon atom/carbon atom ratio is required to be less than 0.25. Here, the fluorine atom/carbon atom ratio and the silicon atom/carbon atom ratio are based on the composition of fluorine atoms, carbon atoms, and silicon atoms measured by X-ray photoelectron spectroscopy (XPS) from the antifouling layer side of the antireflection film than the calculated value.

In the present invention, the fluorine atoms in the antifouling layer 8 exist in a certain amount or more, and the silicon atoms exist in a certain amount or less, that is, by using a predetermined fluorine-containing compound in a fixed amount, excellent antifouling properties can be obtained without slight Blanched anti-reflective film. In addition, since the antifouling layer is uniformly formed over the entire surface, by having the above-mentioned atomic ratio over the entire surface, more excellent antifouling properties can be obtained and the occurrence of slight whitening can be reduced.

From this point of view, the fluorine atom/carbon atom ratio is more preferably 0.7 to 1.0, and the silicon atom/carbon atom ratio is more preferably 0.01 to 0.2. If the fluorine atom/carbon atom ratio is less than 0.6, the antifouling property will be insufficient. On the other hand, if it exceeds 1.0, the treatment of the reagent used to realize this value, that is, the treatment of the fluorine-containing compound becomes very difficult. In addition, if the silicon atom/carbon atom ratio is 0.25 or more, the antifouling property will be insufficient. Therefore, in the present invention, the ratio is set to be less than 0.25. However, by being in such a range, excellent sliding properties can be expected. Scuff resistance.

When a sea-island structure is confirmed by an atomic force microscope (AFM), or a convex portion is observed in a part thereof, and the average surface roughness is outside the range specified in the present invention, the X-ray photoelectron is passed from the antifouling layer side. The atomic ratio measured by energy spectrometry (XPS) is not within the range of the above atomic ratio. That is, in the coating film obtained by applying the composition for forming a low refractive index layer, the phase is separated into a low refractive index phase and an antifouling phase, and the antifouling layer is formed as a uniform layer on the low refractive index layer The case can be confirmed by measuring the above-mentioned atomic ratio specified in the present invention; the case that the antifouling layer is a uniform layer can also be confirmed by the measurement by atomic force microscope (AFM). Therefore, when the antifouling layer has the average surface roughness and atomic ratio specified in the present invention, it can be said that in addition to obtaining excellent antifouling properties, scratch resistance can be obtained and an antifouling layer that does not appear even slight whitening can be obtained. Reflective film. In the present invention, according to the average surface roughness (Ra') measurement by the above-mentioned atomic force microscope (AFM) or the observation of the topography image and the phase image, and the atomic ratio measured by X-ray photoelectron spectroscopy (XPS), it can be used as a judgment Whether it is an antireflection film manufactured by the production method of the present invention or an evaluation method of the antireflection film of the present invention is used. The presence of the antifouling layer on the low-refractive index layer can sometimes be observed by TEM cross-sectional observation, but if an extremely thin layer is considered, the evaluation method described above is effective. In addition, when the antifouling layer is formed by vapor deposition methods such as chemical vapor deposition (CVD) and physical vapor deposition (PVD), unlike the production method of the present invention, since the antifouling layer and the low refractive index layer are not in accordance with the respective layers, The reactive group of the material reacts, so the adhesion is weak, so the scratch resistance is weakened. That is, the difference in the production method can be confirmed by the scratch resistance evaluation. Here, the scratch resistance evaluation is as follows: by applying a load of 300 g/cm ² or more to steel wool (BONSTAR #0000 manufactured by Japan Steel Wool Co., Ltd.) and rubbing it back and forth 10 times on the surface of the antireflection film, the scratch resistance is evaluated visually. The number of scars caused by the surface.

The silicon atoms in the low-refractive index layer and the antifouling layer exist in the form of SiO ₂ or C-Si-O. In the present invention, the silicon atoms from SiO ₂ are called inorganic silicon atoms, and the silicon atoms from C-Si-O Silicon atoms are called organosilicon atoms. That is, in the present invention, the silicon atoms in the low refractive index layer and the antifouling layer include organic silicon atoms and inorganic silicon atoms.

Inorganic silicon atoms and organic silicon atoms are considered to appear separately in the Si2p spectrum due to their different bond energies. According to the peak separation analysis, the peak near 103-104 eV on the high bond energy side was identified as an inorganic silicon atom, and the peak near 101-102 eV on the low bond energy side was identified as an organosilicon atom. The silicon atom in the said silicon atom/carbon atom ratio is set as the numerical value of the total amount of an inorganic silicon atom and an organic silicon atom.

In the present invention, the organosilicon atom/carbon atom ratio measured by X-ray photoelectron spectroscopy (XPS) from the antifouling layer side is preferably 0.07 or less, more preferably 0.01 to 0.07, and even more preferably 0.02 to 0.06. In addition, the inorganic silicon atom/carbon atom ratio is preferably 0.2 or less, more preferably 0.05 to 0.2, and even more preferably 0.08 to 0.18. When the organosilicon atom/carbon atom ratio and the inorganic silicon atom/carbon atom ratio are within the above-mentioned ranges, an antireflection film exhibiting excellent scratch resistance and antifouling property without slight whitening can be obtained.

In the present invention, by satisfying the above-mentioned atomic ratio, it is not necessary to improve the compatibility of fluorine-containing compounds as in the past, and the method of phase-separating the entire surface of the low refractive index layer by using the composition for forming the low refractive index layer can be coated. An antifouling layer is formed which suppresses the occurrence of the above-mentioned sea-island structure and becomes a uniform layer with a small average surface roughness.

In addition, by using a composition for forming a low-refractive index layer that combines a fluorine-containing compound, fine particles, and a binder resin, not only can a uniform antifouling layer 8 be obtained, but as a result, an excellent antireflective property can be obtained. Anti-reflection film with anti-scratch and anti-fouling properties, and suppresses slight whitening.

As long as it is a smooth surface, the contact angle of hexadecane will not exceed 90° theoretically due to the formation of organic compounds such as antifouling layers. Therefore, the contact angle and the sliding angle can be measured with various commercially available contact angle goniometers and sliding goniometers using hexadecane as a measurement liquid.

In the antireflection film 1 of the present invention, when the outermost surface thereof is used as the antifouling layer 8, the contact angle of hexadecane with respect to the surface is preferably 55 to 90°, more preferably 60 to 90°, and the hexadecane The sliding angle of alkane relative to the surface is preferably 1-25°, more preferably 1-20°, and the outermost surface is uniform, that is, the antifouling layer 8 has a smooth structure. When the fluorine-containing compound contained in the antifouling layer 8 is coated on the surface, the contact angle and the sliding angle are within the above-mentioned ranges. outside the above range.

The total thickness of the low refractive index layer 3 and the antifouling layer 8 varies depending on the required refractive index, but is preferably about 80 to 120 nm as described above from the viewpoint of reducing the reflectance in the visible light region. In addition, it is more preferably 100 to 120 nm.

The thickness of the antifouling layer 8 alone is estimated to be in the range of 1 to 3 nm. The atoms contained in the particles in the low refractive index layer can also be detected when analyzed by the above-mentioned X-ray photoelectron spectroscopy (XPS). 3nm, it is estimated that it is more appropriate in the range of 1 to 3nm.

(hard coat 4)

The antireflection film 1 of the present invention may have a hard coat layer 4 in order to improve surface hardness performance such as scratch resistance of the antireflection film 1 . Here, a hard coat means the performance which shows the hardness of "H" or more in the pencil hardness test prescribed|regulated by JIS5600-5-4:1999.

The hard coat layer is preferably a layer obtained by crosslinking and curing an ionizing radiation curable resin. The ionizing radiation-curable resin forming the hard coat layer 4 can be appropriately selected from the ionizing radiation-curable resins used for the binder resin in the composition for forming a low-refractive index layer described above. When the ionizing radiation curable resin is an ultraviolet curable resin, the photopolymerization initiator to be used can also be appropriately selected from those exemplified above and used. In addition, various additives used in the above-mentioned composition for forming a low-refractive index layer can also be used in the same manner.

The cured film thickness of the hard coat layer 4 is preferably in the range of 0.1-100 μm, more preferably in the range of 0.8-20 μm, still more preferably in the range of 1-8 μm, particularly preferably in the range of 1.5-4 μm. As long as the film thickness is within the above range, sufficient hard coating performance can be obtained, and it is difficult to crack against external impact. In addition, in the present invention, the hard coat layer 4 may be a layer having the function of the middle refractive index layer 5 or the high refractive index layer 6 as described below, or a layer having the function of the antistatic layer.

(middle refractive index layer 5 and high refractive index layer 6)

In order to improve the antireflection performance, the antireflection film 1 of the present invention may preferably have the middle refractive index layer 5 and the high refractive index layer 6 . Here, the middle refractive index layer 5 and the high refractive index layer 6 are in the form of the anti-reflection film 1, and it is not necessary to set the middle refractive index layer 5 and the high refractive index layer 6 at the same time as described above, and it may be, for example, as shown in FIG. One layer is provided in the form of a medium-high refractive index layer 7 .

The refractive index of the middle refractive index layer 5 , the high refractive index layer 6 , or the middle and high refractive index layer 7 (hereinafter also referred to as these refractive index layers) can preferably be set arbitrarily within the range of 1.5 to 2.00. That is, the medium refractive index layer 5 is a layer having at least a higher refractive index than the low refractive index layer 3 and a lower refractive index than the high refractive index layer 6 , and the high and low refractive indices are relative values. The refractive indices of the middle refractive index layer 5 and the high refractive index layer 6 are relative values as described above, but generally, it is preferable that the refractive index of the middle refractive index layer 5 is in the range of 1.5 to 1.8, and the refractive index of the high refractive index layer 6 is in the range of 1.6. ~2.0 range.

These refractive index layers can be formed of, for example, a binder resin and fine particles having a particle diameter of 100 nm or less and a predetermined refractive index. Specific examples of particles with such a specified refractive index (refractive index shown in parentheses) include ZnO (1.90), TiO ₂ (2.3-2.7), CeO ₂ (1.95), indium tin oxide (abbreviated as ITO; 1.95), antimony-doped tin oxide (abbreviated as ATO; 1.80), Y ₂ O ₃ (1.87), ZrO ₂ (2.0). Moreover, as a binder resin, it can select suitably from the said binder resin, and can use it.

The fine particles preferably have a higher refractive index than a cured film of the binder resin alone. Since the refractive index of these refractive index layers is generally determined by the content of fine particles, the larger the amount of fine particles added, the higher the refractive index of the refractive index layer. Therefore, a refractive index layer having a predetermined refractive index can be formed by adjusting the addition ratio of the binder resin and the fine particles. As long as the fine particles are conductive fine particles, the refractive index layer formed using such fine particles has antistatic properties. These refractive index layers can be vapor-deposited films of inorganic oxides with a high refractive index of titanium dioxide or zirconia formed by chemical vapor deposition (CVD), physical vapor deposition (PVD) and other vapor deposition methods, or using titanium dioxide A cured film of a resin composition in which inorganic oxide fine particles having a high refractive index are dispersed in a suitable binder resin.

The film thickness of these refractive index layers is preferably in the range of 10 to 300 nm, more preferably in the range of 30 to 200 nm. The above-mentioned refractive index layer (middle refractive index layer, high refractive index layer) can be directly arranged on the transparent substrate 2, but preferably a hard coat layer 4 is arranged on the transparent substrate 2, between the hard coat layer 4 and the low refractive index layer 3 between settings.

(antistatic layer)

The antireflection film 1 of the present invention may preferably have an antistatic layer from the viewpoint of obtaining anti-dust adhesion by utilizing the antistatic effect, or conductivity and electromagnetic wave shielding effect when the antireflection film of the present invention is used in an image display device. The antistatic layer is preferably arranged between the transparent base material 2 and the low-refractive index layer 3. When the above-mentioned hard coat layer 4, medium-refractive-index layer 5, or high-refractive-index layer 6 are provided, it is preferred that the low-refractive-index layer 3 It is provided on the outermost surface and provided so as to be adjacent to the low refractive index layer 3 .

It does not specifically limit as an antistatic layer, For example, the layer formed with the composition for antistatic layers containing resin and an antistatic agent is mentioned preferably.

The antistatic agent is not particularly limited, and examples include cationic compounds such as quaternary ammonium salts, pyridinium salts, and primary to tertiary amino groups; and anionic compounds such as sulfonates, sulfate ester salts, phosphate ester salts, and phosphonate salts. Compounds; amphoteric compounds such as amino acid series and aminosulfate series; nonionic compounds such as amino alcohol series, glycerin series, and polyethylene glycol series; organometallic compounds such as tin and titanium alkoxides; the organometallic Metal chelate compounds such as acetylacetonate salts of compounds, etc. Compounds obtained by increasing the molecular weight of the compounds listed above can also be used.

As an antistatic agent, organometallic compounds such as monomers or oligomers or coupling agents with functional groups that have tertiary amino groups, quaternary ammonium groups, or metal chelating moieties that can be polymerized by ionizing rays can also be preferably cited. and other polymeric compounds. These antistatic agents should just be ionic liquids.

As an antistatic agent, a conductive polymer is also mentioned preferably. The conductive polymer is not particularly limited, and examples thereof include aromatic conjugated poly(p-phenylene), heterocyclic conjugated polypyrrole, polythiophene, aliphatic conjugated polyacetylene, Polyaniline of heteroatom conjugated system, polyparaphenylene vinylene of mixed conjugated system, multi-chain conjugated system of conjugated system with multiple conjugated chains in the molecule, making the aforementioned conjugated polymer chains and saturated Conductive composites of polymer grafted or block copolymerized polymers, etc.

Preferable examples of the antistatic agent include conductive metal oxide fine particles. The conductive metal oxide fine particles are not particularly limited, and examples include ZnO (refractive index 1.90, values in parentheses below represent refractive indices), Sb ₂ O ₂ (1.71), SnO ₂ (1.997), CeO ₂ ( 1.95), indium tin oxide (referred to as ITO; 1.95), In ₂ O ₃ (2.00), Al ₂ O ₃ (1.63), antimony-doped tin oxide (referred to as ATO; 2.0), aluminum-doped zinc oxide (referred to as AZO; 2.0) etc.

The content of the antistatic agent in the composition for an antistatic layer is preferably blended appropriately within a range that can fully enjoy the effect of containing the antistatic agent without hindering the above-mentioned effect obtained by the optical laminate produced by the present invention.

The resin in the antistatic layer, that is, the resin used in the composition for the antistatic layer is not particularly limited, and examples thereof include resins cured by ultraviolet rays or electron beams that are the same as those described in the above-mentioned hard coat layer. Ionizing radiation-curable resin, a mixture of ionizing radiation-curable resin and solvent-drying resin, or thermosetting resin.

The antistatic layer can be formed as follows: On the above-mentioned light-transmitting substrate, etc., a coating film formed by applying the above-mentioned composition for an antistatic layer prepared using each material, drying the coating film as necessary, Formed by curing such as radiation or heating.

[Polarizing plate]

The polarizing plate of the present invention has an antireflection film on at least one side of the polarizing film. index layer, and an antifouling layer covering the entire surface of the low-refractive-index layer, the low-refractive-index layer and the antifouling layer are formed using a composition for forming a low-refractive index layer containing a fluorine-containing compound, microparticles, and a binder resin. As a result, the fluorine atom/carbon atom ratio measured by X-ray photoelectron spectroscopy (XPS) from the antifouling layer side is 0.6 to 1.0, and the silicon atom/carbon atom ratio is less than 0.25, and the average surface roughness of the antifouling layer is (Ra') is 10 nm or less. With such a configuration, the polarizing plate of the present invention becomes an element having an anti-reflection function excellent in physical strength and light resistance, and it is also possible to significantly reduce the cost and reduce the weight of the display device.

Generally, a polarizing plate is provided with a protective film on both surfaces of a polarizing film, but the polarizing plate of the present invention is a polarizing plate in which the antireflection film of the present invention is provided on at least one surface thereof. In the present invention, the antireflection film of the present invention may be provided on one or both surfaces of a polarizing film. When provided on one side, it is preferable that the other side is an optical compensation film (retardation film) having an optical compensation layer including an optically anisotropic layer from the viewpoint of improving viewing angle characteristics of a liquid crystal display screen.

When using the antireflection film of the present invention as a protective film, it is particularly preferable to use a triacetyl cellulose film as a transparent support. At this time, the transparent support using the protective film of the antireflection film is preferably bonded to the polarizing film via an adhesive layer containing polyvinyl alcohol or the like as necessary. In addition, as described above, it is preferable that the other side of the polarizing film also has a protective film, preferably the above-mentioned optical compensation film (retardation film). The surface on the opposite side to the polarizing film of another protective film may have an adhesive layer. By setting it as such a structure, the polarizing plate of this invention can improve the contrast in a bright room of a liquid crystal display device, and the viewing angle of up, down, left, and right.

[Image display device]

The image display device of the present invention has an anti-reflection film or a polarizing plate on the outermost surface of the display, and the polarizing plate is a polarizing plate having an anti-reflection film on at least one side of the polarizing film. The film obtained by the production method is characterized by at least sequentially having a transparent substrate, a low refractive index layer, and an antifouling layer covering the entire surface of the low refractive index layer, and the low refractive index layer and the antifouling layer are used containing A composition for forming a low-refractive index layer of fluorine compound, microparticles, and binder resin, wherein the fluorine atom/carbon atom ratio measured from the antifouling layer side by X-ray photoelectron spectroscopy (XPS) is 0.6 to 1.0, And the silicon atom/carbon atom ratio is less than 0.25, and the average surface roughness (Ra') of the antifouling layer is less than 10nm.

As the display, for example, liquid crystal display (LCD), plasma display panel (PDP), cathode tube display device (CRT), inorganic and organic electroluminescence display, rear projection display, fluorescent display tube (VFD), touch Displays such as control panels, mobile computers, and electronic paper. Moreover, as an image display device, devices equipped with these displays, such as a personal computer, a mobile information terminal, a game machine, a digital camera, a digital video camera, etc. are mentioned preferably.

Example

Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to these Examples.

(Evaluation method)

1. Minimum reflectance (evaluation of anti-reflection characteristics)

For the anti-reflection film obtained in each embodiment and comparative example, a black adhesive tape for preventing the back reflection of the film is pasted on the side of the transparent substrate where the low-refractive index layer is not provided, and from the surface of the low-refractive index layer, use The reflectance was measured with a spectrometer ("UV-2550 (model)": manufactured by Shimadzu Corporation) equipped with a regular reflection measuring device at 5 degrees, and the minimum value in the wavelength region of 380 to 780 nm was taken as the minimum reflectance. The smaller the minimum reflectance, the better the antireflection property of the antireflection film.

2. Evaluation of coated surface

A black tape was affixed to the film surface on the side where the low-refractive index layer was not formed, and visually observed with a three-wavelength lamp from the surface where the low-refractive index layer was formed, and the results were evaluated based on the following criteria.

◯: The surface of the low-refractive index layer is uniform.

Δ: The surface of the low-refractive index layer was slightly deformed compared with the evaluation of ○ above.

×: The surface of the low-refractive index layer appears slightly white.

3. Evaluation of surface scratch resistance and adhesion

The antireflection film obtained in each of the examples and comparative examples was reciprocated and rubbed 10 times with steel wool (BONSTAR #0000 manufactured by Nippon Steel Wool Co., Ltd.) under a load of 300 g/cm ² , and evaluated visually according to the following criteria. result. The smaller the number of scratches, the better the scratch resistance and the adhesion between the low-refractive index layer and the antifouling layer.

◯: No scars were formed at all.

Δ: The number of scratches is 1 to 5.

×: The number of scars is 6 or more.

4. Evaluation of antifouling properties

After attaching fingerprints to the surface of the antireflection film obtained in each Example and Comparative Example, it was wiped with BEMCOTM-3 (manufactured by Asahi Kasei Corporation), and the ease of wiping was visually confirmed and evaluated according to the following criteria.

○: Fingerprints can be easily wiped off.

Δ: Fingerprints can be wiped off.

x: Fingerprints cannot be wiped off.

(2) The state when the surface of the antireflection film obtained in each Example and Comparative Example was drawn with an oil-based marker and the state after wiping with a cloth were visually confirmed, and evaluated according to the following criteria.

◎: The ink gathers into balls and is easy to wipe off.

○: The ink does not stick to the surface, the line becomes thinner, and it is easy to wipe off.

X: Traces of ink remain after wiping.

5. Determination of the atomic ratio of the low refractive index layer based on X-ray photoelectron spectroscopy

By X-ray photoelectron spectroscopy (XPS), the surface (anti-fouling layer) of the anti-reflection film obtained in each embodiment and comparative example was analyzed, and the atomic ratio was obtained according to the following method. An indicator of the formation of an antifouling layer.

The device used is XPS device (“ESCALAB220i-XL (model)”, manufactured by THERMOFISHERSCIENTIFIC Co., Ltd.), X-ray output power used: 10kV·16mA (160W), lens: LargeAreaXL (magnetic field lens), aperture opening: FOV=open, AA =open, measurement area: , Photoelectron acceptance angle: 90 degrees (input lens is configured online in the sample method), neutralization charge: electron neutralization gun +4 (V)·0.08 (mA), analysis is performed under the use of a metal mask for neutralization assistance. Using the atomic composition of carbon atoms, nitrogen atoms, oxygen atoms, fluorine atoms, and silicon atoms on the surface of the antireflection film obtained by the measurement, the fluorine atom/carbon atom ratio and the silicon atom/carbon atom ratio were calculated. In addition, silicon atoms are classified into inorganic silicon components (SiO ₂ ) with peaks detected around 103 to 104 eV and organic silicon components (C-Si -O), measure the atomic composition, and calculate the ratio of inorganic silicon atoms/carbon atoms and organic silicon atoms/carbon atoms.

6. Evaluation of surface state (measurement of contact angle and slip angle)

For the antireflection films obtained in Examples and Comparative Examples, using hexadecane as a measurement liquid, the contact angle and slip angle were measured with a measuring device (“DM-500 (model)”, manufactured by Kyowa Interface Science Co., Ltd.). The droplet volume was set at 2 μl.

7. Evaluation of surface state (evaluation based on surface observation by atomic force microscope)

Using an atomic force microscope (AFM) ("L-trace (model)", manufactured by SIINANOTECHNOLOGY Co., Ltd.), the dynamic force mode (DynamicForceMode) scanning frequency: 0.4 ~ 1.0Hz, scanning range: 3μm, observed the results of each example and comparative example The topographic image and phase image of the surface of the anti-reflection film. As the cantilever, "OMCL-AC160TS-C2 (model)" (manufactured by KSOLYMPUS Co., Ltd., elastic constant: 42 N/m) was used. Here, a new cantilever was always used so that the resolution of the cantilever used for observation would not be reduced due to probe contamination. In addition, in order to prevent wear and tear during observation, the load on the probe was reduced as much as possible without sacrificing resolution, and observation was performed at a resolution of 512 pixels×256 pixels. After observation, the inclination of the data is corrected using the attached software.

From this surface observation, when the entire surface of the low-refractive index layer is phase-separated to form an antifouling layer, a uniform state can be confirmed. The inhomogeneous pattern of separated and unseparated parts presents a sea-island pattern. Here, as long as it is in a uniform state, it can be said that there is no slight whitening and no roughness of the coated surface even when viewed visually, and the low refractive index layer and the antifouling layer are formed satisfactorily.

○: The antifouling layer is uniform.

Δ: Although there is no sea-island structure in the antifouling layer, slight deformation is observed compared with the evaluation of ○ above.

×: The antifouling layer exhibited a sea-island structure, and slight whitening or roughness of the coated surface was visually observed.

8. Determination of average surface roughness (Ra')

The surface shape was observed with the above-mentioned atomic force microscope (AFM), and the image analysis was performed with analysis software (SPIwin) to obtain the average surface roughness (Ra').

Preparation Example 1: Preparation of Low Refractive Index Layer Forming Composition 1

The components of the following composition were mixed in the following mass ratio, and the composition 1 for low-refractive-index layer formation was prepared.

Composition 1 for forming a low refractive index layer

Pentaerythritol triacrylate (PETA): 0.10 parts by mass

Fluorine-containing compound ^*1 : 1.23 parts by mass

Hollow silica particle dispersion ^*2 : 6.69 parts by mass

Solid silica particle dispersion ^*3 : 0.74 parts by mass

Fluoropolymer ^*4 : 2.79 parts by mass

Fluorinated monomer ^*5 : 2.23 parts by mass

Photopolymerization initiator ^*6 : 0.08 parts by mass

Methyl isobutyl ketone: 57.03 parts by mass

Propylene glycol monomethyl ether acetate: 29.1 parts by mass

*1, "X-71-1203M (trade name)": Shin-Etsu Chemical Co., Ltd., 20% by mass solution (solvent: methyl isobutyl ketone, photocurable reactive group: (meth)acryloyl group, containing A fluorine-containing compound having a reactive silane unit, and a silane unit having a perfluoropolyether group).

*2, the hollow silica particle content in the dispersion liquid is 20% by mass, and the solvent (methyl isobutyl ketone) content is 80% by mass. In addition, the hollow silica particles have an average particle diameter of 60 nm and have photocurable reactive groups by surface treatment.

*3, "MIBK-SD (trade name)", average primary particle size: 12nm, solid content: 30% by mass, solvent: methyl isobutyl ketone, solid silica particles have a photocurable reaction by surface treatment group of methacryloyl.

*4, "OPSTAR JN35 (trade name)", manufactured by JSR Corporation, 20% by mass solution (solvent: methyl isobutyl ketone).

*5, "LINC3A (trade name)": manufactured by Kyoeisha Chemical Co., Ltd., fluorine-containing monomer having a pentaerythritol skeleton, 20% by mass solution (solvent: methyl isobutyl ketone).

*6, "IRGACURE127 (trade name)": manufactured by Ciba Chemical Co., Ltd.

Preparation Example 2: Preparation of Hard Coat Forming Composition 1

The components of the following composition were mixed in the following mass ratio, and the composition 1 for hard-coat layer formation was prepared.

Composition 1 for forming a hard coat layer

Urethane acrylate ^*7 : 15 parts by mass

Isocyanuric acid EO modified triacrylate ^*8 : 15 parts by mass

Polymerization initiator ^*9 : 2 parts by mass

Methyl ethyl ketone: 70 parts by mass

*7, "UV1700B (trade name)", manufactured by Nippon Synthetic Chemicals Co., Ltd.

*8, "M315 (trade name)", manufactured by Toagosei Co., Ltd.

*9, "IRGACURE184 (trade name)": manufactured by Ciba Specialty Chemicals Co., Ltd.

Example 1

On a triacetyl cellulose (TAC) resin film with a thickness of 80 μm, the composition 1 for forming a hard coat layer was bar-coated, dried at 50° C. for 1 minute, and the solvent was removed, and then the composition 1 was applied by an ultraviolet irradiation device (a light source manufactured by FUSIONUV SYSTEMS JAPAN Co., Ltd.). H-BULB) was cured by ultraviolet irradiation at a dose of 30 mJ/cm ² to obtain a hard coating with a thickness of about 10 μm.

Next, on the obtained hard coat layer, the composition 1 for forming a low-refractive index layer prepared in Preparation Example 1 was bar-coated to form a coating film (step (1)); heat treatment was performed at 50° C. for 1 minute, The coating film is phase-separated into a low refractive index phase and an antifouling phase, and the solvent is removed (step (2)); UV radiation is irradiated with an irradiation dose of 200mJ/ ^cm2 to cure it, forming a low refractive index layer and an antifouling layer ( Step (3)) to obtain an antireflection film having a transparent substrate, a hard coat layer, a low refractive index layer, and an antifouling layer. The solvent evaporated almost completely during curing, and the total thickness of the low-refractive index layer and the antifouling layer was about 100 nm. In addition, when the atomic ratio is measured by X-ray photoelectron spectroscopy (XPS), atoms contained in fine particles in the low refractive index layer are also detected. Considering that the thickness of the anti-fouling layer by X-ray photoelectron spectroscopy (XPS) is 1-3 nm, it is estimated that the thickness of the obtained anti-fouling layer is in the range of 1-3 nm.

Table 1 shows the results of evaluating the obtained antireflection film according to the evaluation method described above. In addition, an atomic force microscope (topography image and phase image) is shown in FIG. 4 .

Example 2

An antireflection film was obtained in the same manner as in Example 1 except that the composition 1 for forming a low-refractive index layer in Example 1 was replaced with the composition 2 for forming a low-refractive index layer described below. Table 1 shows the results of evaluating the obtained antireflection film according to the evaluation method described above. In addition, an atomic force microscope image (topography image and phase image) is shown in FIG. 5 .

Composition 2 for forming a low refractive index layer

Pentaerythritol triacrylate (PETA): 1.32 parts by mass

Fluorine-containing compound ^*1 : 1.32 parts by mass

Hollow silica particle dispersion ^*2 : 6.61 parts by mass

Photopolymerization initiator ^*6 : 0.07 parts by mass

Methyl isobutyl ketone: 61.03 parts by mass

Propylene glycol monomethyl ether acetate: 29.1 parts by mass

Example 3

An antireflection film was obtained in the same manner as in Example 1 except that the composition 1 for forming a low-refractive index layer in Example 1 was replaced with the composition 3 for forming a low-refractive index layer described below. Table 1 shows the results of evaluating the obtained antireflection film according to the evaluation method described above. In addition, an atomic force microscope image (topography image and phase image) is shown in FIG. 6 .

Composition 3 for forming a low refractive index layer

Pentaerythritol triacrylate (PETA): 0.12 parts by mass

Fluorine-containing compound ^*1 : 2.07 parts by mass

Hollow silica particle dispersion ^*2 : 6.28 parts by mass

Solid silica particle dispersion ^*3 : 0.7 parts by mass

Fluoropolymer ^*4 : 2.62 parts by mass

Fluorinated monomer ^*5 : 2.09 parts by mass

Photopolymerization initiator ^*6 : 0.07 parts by mass

Methyl isobutyl ketone: 56.96 parts by mass

Propylene glycol monomethyl ether acetate: 29.1 parts by mass

Preparation Example 3: Preparation Example of High Refractive Index Layer Forming Composition

Put and mix rutile-type titanium oxide (“TTO51(C) (trade name)”, manufactured by Ishihara Sangyo Co., Ltd., primary particle size: 0.01 to 0.03 μm) in a mayonnaise bottle: 10 parts by mass, dispersion containing anionic groups Agent ("DISPERBYK-163 (trade name)", BYKCHEMIE JAPAN company make): 2 mass parts, and methyl isobutyl ketone: 48 mass parts, and the mixture was produced. The resulting mixture was stirred for 10 hours with a paint shaker using about four times the amount of zirconia beads (φ0.3 mm) to prepare a composition for forming a high refractive index layer.

Preparation Example 4: Preparation Example of a Composition for Forming a Middle Refractive Index Layer

In addition to the preparation example of the above-mentioned composition for forming a high refractive index layer, the rutile-type titanium oxide was replaced with antimony-doped tin oxide ("SN-100P (trade name)", manufactured by Ishihara Sangyo Co., Ltd.), anion-containing Except that the base-based dispersant was replaced with "DISPERBYK-111 (trade name)" (manufactured by BYK CHEMIE JAPAN), a composition for forming a middle refractive index layer was prepared in the same manner as in the preparation example of the composition for forming a high refractive index layer.

Example 4

On a triacetyl cellulose (TAC) resin film with a thickness of 80 μm, the above-mentioned composition 1 for forming a hard coat layer was bar-coated, dried at 50° C. for 1 minute, and after removing the solvent, it was irradiated with an ultraviolet ray irradiation device (manufactured by FUSIONUV SYSTEMS JAPAN Co., Ltd.). The light source H-BULB) was irradiated with ultraviolet light at a dose of 30 mJ/cm ² to cure it, and a hard coating with a thickness of about 10 μm was obtained.

On the obtained hard coat layer, the composition for forming a medium refractive index layer obtained in Preparation Example 4 was bar-coated, and cured by ultraviolet irradiation at a dose of 200 mJ/cm ² to form a high refractive index layer with a thickness of about 120 nm. The composition for forming a high-refractive index layer obtained in Preparation Example 3 was bar-coated, and cured by ultraviolet irradiation at a dose of 200 mJ/cm ² to form a high-refractive index layer with a thickness of about 60 nm. Next, the following composition 4 for forming a low-refractive index layer was bar-coated to form a coating film (step (1)); heat treatment was performed at 50° C. for 1 minute to phase-separate the coating film into a low-refractive-index phase and an antifouling phase. phase, and remove the solvent (step (2)); irradiate with ultraviolet light at a dose of 200mJ/ ^cm2 to cure it, form a low refractive index layer and an antifouling layer (step (3)), and obtain a transparent substrate, hard Anti-reflection film for coating layer, medium refractive index layer, high refractive index layer, low refractive index layer, and antifouling layer. The solvent evaporates almost completely during curing, and the total thickness of the low-refractive index layer and the antifouling layer is about 100 nm. In addition, when the atomic ratio is measured by X-ray photoelectron spectroscopy (XPS), atoms of fine particles contained in the low refractive index layer are also detected. Considering that the thickness of the anti-fouling layer according to X-ray photoelectron spectroscopy (XPS) is 1-3 nm, it is estimated that the thickness of the obtained anti-fouling layer is in the range of 1-3 nm.

Table 1 shows the results of evaluating the obtained antireflection film according to the evaluation method described above. In addition, an atomic force microscope image (topography image and phase image) is shown in FIG. 7 .

Composition 4 for forming a low refractive index layer

Pentaerythritol triacrylate (PETA): 0.32 parts by mass

Fluorine-containing compound ^*1 : 0.71 parts by mass

Hollow silica particle dispersion ^*2 : 6.42 parts by mass

Solid silica particle dispersion ^*3 : 1.43 parts by mass

Fluoropolymer ^*4 : 3.21 parts by mass

Fluorinated monomer ^*5 : 0.54 parts by mass

Photopolymerization initiator ^*6 : 0.07 parts by mass

Methyl isobutyl ketone: 58.2 parts by mass

Propylene glycol monomethyl ether acetate: 29.1 parts by mass

Example 5

An antireflection film was obtained in the same manner as in Example 1 except that the composition 1 for forming a low-refractive index layer in Example 1 was replaced with the composition 5 for forming a low-refractive index layer described below. Table 1 shows the results of evaluating the obtained antireflection film according to the evaluation method described above. In addition, an atomic force microscope image (topography image and phase image) is shown in FIG. 8 .

Composition 5 for forming a low refractive index layer

Pentaerythritol triacrylate (PETA): 0.10 parts by mass

Fluorine-containing compound ^*10 : 1.23 parts by mass

Hollow silica particle dispersion ^*2 : 6.69 parts by mass

Solid silica particle dispersion ^*3 : 0.74 parts by mass

Fluoropolymer ^*4 : 2.79 parts by mass

Fluorinated monomer ^*5 : 2.23 parts by mass

Photopolymerization initiator ^*6 : 0.08 parts by mass

Methyl isobutyl ketone: 57.04 parts by mass

Propylene glycol monomethyl ether acetate: 29.1 parts by mass

*10, "X-71-1205 (trade name)": Shin-Etsu Chemical Co., Ltd., 20% by mass solution (solvent: a mixture of methyl isobutyl ketone and methyl ethyl ketone, photocurable reactive group: (meth)acryloyl, a fluorine-containing compound containing a reactive silane unit and a silane unit having a perfluoropolyether group).

Example 6

An antireflection film was obtained in the same manner as in Example 1 except that the composition 1 for forming a low-refractive index layer in Example 1 was replaced with the composition 6 for forming a low-refractive index layer described below. Table 1 shows the results of evaluating the obtained antireflection film according to the evaluation method described above.

Composition 6 for forming a low refractive index layer

Dipentaerythritol hexaacrylate (DPHA): 1.32 parts by mass

Fluorine-containing compound ^*1 : 1.32 parts by mass

Hollow silica particle dispersion ^*2 : 6.61 parts by mass

Photopolymerization initiator ^*6 : 0.07 parts by mass

Methyl isobutyl ketone: 61.03 parts by mass

Propylene glycol monomethyl ether acetate: 29.1 parts by mass

Example 7

An antireflection film was obtained in the same manner as in Example 1 except that the composition 1 for forming a low-refractive index layer in Example 1 was replaced with the composition 7 for forming a low-refractive index layer described below. Table 1 shows the results of evaluating the obtained antireflection film according to the evaluation method described above.

Composition 7 for forming a low refractive index layer

Pentaerythritol triacrylate (PETA): 0.10 parts by mass

Fluorine-containing compound ^*1 : 2.93 parts by mass

Hollow silica particle dispersion ^*2 : 5.86 parts by mass

Solid silica particle dispersion ^*3 : 0.65 parts by mass

Fluoropolymer ^*4 : 2.44 parts by mass

Fluorinated monomer ^*5 : 1.95 parts by mass

Photopolymerization initiator ^*6 : 0.07 parts by mass

Methyl isobutyl ketone: 56.89 parts by mass

Propylene glycol monomethyl ether acetate: 29.1 parts by mass

Example 8

An antireflection film was obtained in the same manner as in Example 1, except that the composition 1 for forming a low-refractive index layer in Example 1 was replaced with the composition 8 for forming a low-refractive index layer described below. Table 1 shows the results of evaluating the obtained antireflection film according to the evaluation method described above.

Composition 8 for forming a low refractive index layer

Pentaerythritol triacrylate (PETA): 1.32 parts by mass

Fluorine-containing compound ^*1 : 1.32 parts by mass

Hollow silica particle dispersion ^*2 : 6.61 parts by mass

Photopolymerization initiator ^*6 : 0.07 parts by mass

Methyl isobutyl ketone: 61.03 parts by mass

Toluene: 29.1 parts by mass

Example 9

An antireflection film was obtained in the same manner as in Example 1 except that the composition 1 for forming a low-refractive index layer in Example 1 was replaced with the composition 9 for forming a low-refractive index layer described below. Table 1 shows the results of evaluating the obtained antireflection film according to the evaluation method described above.

Composition 9 for forming a low refractive index layer

Pentaerythritol triacrylate (PETA): 0.11 parts by mass

Fluorine-containing compound ^*11 : 0.25 parts by mass

Hollow silica particle dispersion ^*2 : 6.69 parts by mass

Solid silica particle dispersion ^*3 : 0.74 parts by mass

Fluoropolymer ^*12 : 2.79 parts by mass

Fluorinated monomer ^*5 : 2.23 parts by mass

Photopolymerization initiator ^*6 : 0.08 parts by mass

Methyl isobutyl ketone: 58.01 parts by mass

Propylene glycol monomethyl ether acetate: 29.1 parts by mass

*11, "5101X (trade name)": manufactured by SOLVAY SPECIALTY POLYMERS JAPAN CO., LTD., a tetrafunctional methacrylate-modified perfluoropolyether compound at both ends, a fluorine-containing compound not having a silane unit).

*12, "OPSTARTU2224 (trade name)", manufactured by JSR Corporation, 20% by mass solution (solvent: methyl isobutyl ketone).

Comparative example 1

An antireflection film was obtained in the same manner as in Example 1 except that the composition 1 for forming a low-refractive index layer in Example 1 was replaced with the composition 10 for forming a low-refractive index layer described below. Table 2 shows the results of evaluating the obtained antireflection film according to the evaluation method described above. In addition, an atomic force microscope image (topography image and phase image) is shown in FIG. 9 .

Composition 10 for forming a low refractive index layer

Pentaerythritol triacrylate (PETA): 0.12 parts by mass

Fluorine-containing compound ^*1 : 0.52 parts by mass

Hollow silica particle dispersion ^*2 : 7.04 parts by mass

Solid silica particle dispersion ^*3 : 0.78 parts by mass

Fluoropolymer ^*4 : 2.93 parts by mass

Fluorinated monomer ^*5 : 2.35 parts by mass

Photopolymerization initiator ^*6 : 0.08 parts by mass

Methyl isobutyl ketone: 57.09 parts by mass

Propylene glycol monomethyl ether acetate: 29.1 parts by mass

Comparative example 2

An antireflection film was obtained in the same manner as in Example 1, except that the composition 1 for forming a low-refractive index layer in Example 1 was replaced with the composition 11 for forming a low-refractive index layer described below. Table 2 shows the results of evaluating the obtained antireflection film according to the evaluation method described above. In addition, an atomic force microscope image (topography image and phase image) is shown in FIG. 10 .

Composition 11 for forming a low refractive index layer

Pentaerythritol triacrylate (PETA): 0.09 parts by mass

Fluorine-containing compound ^*1 : 3.79 parts by mass

Hollow silica particle dispersion ^*2 : 5.44 parts by mass

Solid silica particle dispersion ^*3 : 0.6 parts by mass

Fluoropolymer ^*4 : 2.27 parts by mass

Fluorinated monomer ^*5 : 1.81 parts by mass

Photopolymerization initiator ^*6 : 0.06 parts by mass

Methyl isobutyl ketone: 56.82 parts by mass

Propylene glycol monomethyl ether acetate: 29.1 parts by mass

Comparative example 3

An antireflection film was obtained in the same manner as in Example 1 except that the composition 1 for forming a low-refractive index layer in Example 1 was replaced with the composition 12 for forming a low-refractive index layer described below. Table 2 shows the results of evaluating the obtained antireflection film according to the evaluation method described above. In addition, an atomic force microscope image (topography image and phase image) is shown in FIG. 11 .

Composition 12 for forming a low refractive index layer

Pentaerythritol triacrylate (PETA): 0.32 parts by mass

Hollow silica particle dispersion ^*2 : 6.42 parts by mass

Solid silica particle dispersion ^*3 : 1.43 parts by mass

Fluoropolymer ^*4 : 3.21 parts by mass

Fluorinated monomer ^*5 : 0.54 parts by mass

Photopolymerization initiator ^*6 : 0.07 parts by mass

Methyl isobutyl ketone: 58.2 parts by mass

Propylene glycol monomethyl ether acetate: 29.1 parts by mass

Comparative example 4

An antireflection film was obtained in the same manner as in Example 1 except that the composition 1 for forming a low-refractive index layer in Example 1 was replaced with the composition 13 for forming a low-refractive index layer described below. Table 2 shows the results of evaluating the obtained antireflection film according to the evaluation method described above.

Composition 13 for forming a low refractive index layer

Pentaerythritol triacrylate (PETA): 2.64 parts by mass

Fluorine-containing compound ^*1 : 1.32 parts by mass

Photopolymerization initiator ^*6 : 0.07 parts by mass

Methyl isobutyl ketone: 95.42 parts by mass

Comparative Example 5

The fluorine-containing compound used in Example 1 was diluted with m-trifluorotoluene to a solution having a solid content concentration of 3% by mass, and prepared as an antifouling film deposition source.

On a triacetylcellulose (TAC) resin film having a width of 500 mm, a thickness of 80 μm, and a length of 500 m, the composition 1 for forming a hard coat layer was gravure-coated, and the following composition for forming a low-refractive index layer was gravure-coated 13. Dry at 70°C for 1 minute to remove the solvent, and then irradiate with ultraviolet light at a dose of 200mJ/ ^cm2 to cure it, forming a hard coat layer with a thickness of about 10μm and a low refractive index layer with a thickness of about 100nm, and obtain a transparent Laminate of base material/hard coat layer/low refractive index layer.

Next, set the above-mentioned antifouling film evaporation source and the laminated body in a coiling-type evaporation device, and after the vacuum is exhausted to below 1e ^-4 Torr, the laminated body is started to be wound up at a running speed of 5 m/min. The antifouling film deposition source was evaporated by a heating type heating lamp to obtain an antireflection film in which an antifouling film was formed on the low refractive index layer side of the laminate. Table 2 shows the results of evaluating the obtained antireflection film according to the evaluation method described above.

Table 1

*1 is the amount (parts by mass) of the fluorine-containing compound relative to 100 parts by mass (solid content) of the total amount of binder resin (including fluorine-containing monomer and fluorine-containing polymer) and fine particles. Here, the solid content does not contain a polymerization initiator.

Table 2

*1, the amount of fluorine-containing compound relative to the total amount of 100 parts by mass (solid content) of binder resin (including fluorine-containing monomers and fluorine-containing polymers when using fluorine-containing polymers) and fine particles (mass parts ). Here, the solid content does not contain a polymerization initiator.

The antireflection films obtained in Examples 1 to 5 are excellent in all evaluations, have excellent antireflection characteristics, have excellent scratch resistance and antifouling properties, and have no whitening. The results from the contact angle and slip angle It can be seen as a film with a uniform surface. In addition, for Examples 1 to 5, according to the average surface roughness or the observation results of the atomic force microscope, it is also a film with a uniform surface, and it can be confirmed that the antifouling layer is an integral surface covering the low refractive index layer. The way the surface is formed, it is evenly and consistently formed.

In Example 6, in which the binder resin was replaced from PETA to DPHA, almost good physical properties were obtained, but although the coated surface was substantially uniform, it was slightly rough, and the scratch resistance was slightly lowered. In addition, when an antireflection film was produced by substituting DPHA for trimethylolpropane triacrylate (TMPTA) and pentaerythritol tetraacrylate (PETTA), it was confirmed that almost the same results as in Example 6 were obtained. In Example 7 in which the content of the fluorine-containing compound was large, almost good physical properties were obtained, but although the surface state was substantially uniform, it was somewhat rough, and the scratch resistance was slightly lowered. In Example 8, in which toluene was used instead of glycol ethers as a solvent, it is estimated that the dispersibility of fine particles was slightly affected, and although the scratch resistance was slightly lowered, generally good results were obtained. From the results, it was confirmed that the use of ketones and glycol ethers as solvents is effective. In addition, in Example 9 in which the material used in Patent Document 2 was used as a fluorine-containing compound, although a good sample with no sea-island structure and no slight whitening was obtained in the antifouling layer, the smoothness of the coated film surface was poor and it was confirmed that to slight deformation. From this, it was confirmed that the fluorine-containing compound preferably has a silane unit.

In addition, in the antireflection film obtained in the examples, the total thickness of the low refractive index layer and the antifouling layer is estimated to be about 100 nm, and the thickness of the antifouling layer is in the range of 1 to 3 nm.

On the other hand, in Comparative Example 1 in which the content of the fluorine-containing compound was small, the antireflection characteristics were equivalent to those of the examples, but the antifouling properties were not sufficient due to the large silicon content, and whitening was also observed. In addition, the slip angle of 33° cannot be said to have a uniform surface, and the sea-island structure was confirmed from the observation results of the atomic force microscope. This sea-island structure is considered to be caused by the fact that the outermost surface of the low-refractive index layer cannot be completely covered by the lack of fluorine-containing silane compound, and a uniform antifouling layer cannot be formed. This is considered to be the main cause of slight whitening. In Comparative Example 2 in which the fluorine-containing compound was excessively contained, excessive phase separation occurred in the entire low-refractive index layer, the entire surface of the low-refractive index layer was significantly rough, and a uniform antifouling layer was not formed. This roughness is considered to be roughness that occurs on the entire surface of the layer as a result of the excessive fluorine-containing compound causing unevenness due to the protruding parts of the fine particles in the low refractive index layer. Furthermore, since the average surface roughness is large and the amount of fluorine-containing compounds contained in the antifouling layer is large, the antifouling layer becomes soft, and scratches are caused when rubbing when evaluating antifouling properties. In addition, in Comparative Example 3, which did not contain a fluorine-containing compound and had a fluorine atom/carbon atom ratio of less than 0.6, although a uniform surface was obtained, the antifouling property was not sufficient due to the small amount of fluorine. Comparative Example 4 is an example in which fine particles are not used, and since the compatibility between the binder resin and the fluorine-containing compound is poor, the entire coating film becomes white when the coating film dries, and cannot be evaluated. From these results, it can be seen that the function of the fine particles is indispensable in order to maintain the balance between the binder resin and the fluorine-containing compound having poor compatibility and to achieve the final structure. In addition, in Comparative Example 5 in which the antifouling layer was formed by vapor deposition, the antifouling properties and surface state were generally good, but since some reaction between the reactive functional groups in the antifouling phase of the present invention and the low refractive index phase did not occur The cured anti-fouling layer and the low-refractive index layer will have weak adhesion, and the scratch resistance will deteriorate.

Industrial Utilization Possibility

According to the present invention, it is possible to easily manufacture an antireflection film having excellent antireflection properties, excellent scratch resistance and antifouling properties, and suppressing the occurrence of slight whitening which has never been addressed so far. The obtained antireflection film is suitable for installation in polarizing plates and image display devices.

Claims (13)

1. the manufacture method of an antireflection film, it comprises following operation (1) ~ (3) successively, and this antireflection film has transparent base, low-index layer and stain-proofing layer at least successively, from fluorine/carbon that this stain-proofing layer side is measured by X-ray photoelectron spectroscopy XPS, in atom number ratio, be 0.6 ~ 1.0, and silicon/carbon, in atom number ratio, be less than 0.25, the average surface roughness Ra ' of this stain-proofing layer is below 10nm, wherein

Operation (1) is the operation being coated with low-index layer formation composition over the transparent substrate thus forming film, and described low-index layer formation composition is at least containing fluorochemicals, particulate and adhesive resin;

Operation (2) is the operation making this film be separated into low-refraction phase and antifouling phase;

Operation (3) is this low-refraction phase of heating and this antifouling phase, or irradiates ionizing ray mutually to this low-refraction phase and this are antifouling, thus forms the operation of the stain-proofing layer of whole of low-index layer and this low-index layer coating.

2. the manufacture method of antireflection film as claimed in claim 1, wherein, fluorochemicals is containing having the silane unit of reactive group and having the material of silane unit of holo-fluorine polyester.

3. the manufacture method of antireflection film as claimed in claim 2, wherein, has the silane unit of reactive group and has the silane unit of holo-fluorine polyester, having siloxane backbone respectively.

4. the manufacture method of antireflection film as claimed in claim 2 or claim 3, wherein, reactive group is selected from least one in (methyl) acryloyl group and vinyl.

5. the manufacture method of the antireflection film according to any one of claims 1 to 3, wherein, the weight-average molecular weight of fluorochemicals is more than 5000.

6. the manufacture method of the antireflection film according to any one of claims 1 to 3, wherein, particulate is silicon dioxide microparticle.

7. the manufacture method of the antireflection film according to any one of claims 1 to 3, wherein, particulate comprises the particulate with space.

8. the manufacture method of the antireflection film according to any one of claims 1 to 3, wherein, particulate is surface treated particulate.

9. the manufacture method of the antireflection film according to any one of claims 1 to 3, wherein, adhesive resin is ionizing ray curable resin.

10. the manufacture method of antireflection film as claimed in claim 9, wherein, ionizing ray curable resin comprises 3 officials can above (methyl) acrylate.

11. 1 kinds of antireflection films, it is manufactured by the manufacture method of the antireflection film according to any one of claims 1 to 3.

12. 1 kinds of polarization plates, it at least one side of polarizing coating, has antireflection film and this antireflection film is the polarization plates of antireflection film according to claim 11.

13. 1 kinds of image display devices, it has antireflection film or polarization plates in the outmost surface of display, and described polarization plates is the polarization plates at least one side of polarizing coating with antireflection film, and described antireflection film is antireflection film according to claim 11.