KR102246690B1 - Photocurable resin composition, cured coating film formed from the composition, anti-glare film formed from the composition, method of producing cured coating film, and method of producing anti-glare film - Google Patents

Abstract

A photocurable resin composition capable of forming a cured film having excellent anti-glare properties and less luminance unevenness is provided. A photocurable resin composition containing a photopolymerizable component (A), fine particles (B) and a photopolymerization initiator (C), wherein the photopolymerizable component (A) is a photopolymerizable (meth)acrylic resin (a1) having a weight average molecular weight of 10,000 or more. A sight characterized in that the fine particles (B) contain organic fine particles and/or inorganic fine particles having an average particle diameter of 1.0 μm or more and 2.8 μm or less, and the viscosity at 23° C. is 1 mPa·s or more and 1000 mPa·s or less. It is a chemical conversion resin composition.

Description

Photocurable resin composition, cured film and anti-glare film formed from this composition, and method of manufacturing cured film and anti-glare film {PHOTOCURABLE RESIN COMPOSITION, CURED COATING FILM FORMED FROM THE COMPOSITION, ANTI-GLARE FILM FORMED FROM THE COMPOSITION, METHOD OF PRODUCING CURED COATING FILM, AND METHOD OF PRODUCING ANTI-GLARE FILM}

The present invention relates to a photocurable resin composition, a cured film and an anti-glare film formed from the composition, and a method for producing a cured film and an anti-glare film.

In image display devices such as tablet terminals and televisions (hereinafter, also simply referred to as displays), the visibility of the screen is lowered by the light of sunlight or fluorescent lamps being reflected on the screen. Therefore, in order to suppress see-through, an anti-glare film is provided on the surface of the display.

In general, an anti-glare film is constituted by laminating a transparent base material and a cured film having anti-glare properties (hereinafter, also simply referred to as an anti-glare layer). The anti-glare layer is formed, for example, by coating and curing a photocurable resin composition containing fine particles on a transparent substrate, and has minute irregularities due to fine particles on the surface. According to the anti-glare film, since the anti-glare layer exhibits anti-glare properties by scattering or diffusing light due to irregularities, reflection can be suppressed.

By the way, in recent years, in a display, the resolution is improved, and the displayed image becomes higher definition. With the improvement of this resolution, in the case of the anti-glare film, when affixed to a high-resolution display, a problem arises in that luminance unevenness occurs on the surface of the anti-glare layer and the visibility of the screen decreases. The luminance unevenness is when the display is turned on, when the transmitted light from the rear reaches the screen, a minute luminance (brightness) unevenness appears on the screen surface, and when the viewer changes the viewing angle, the location of the luminance unevenness changes. This is a phenomenon that looks like this, and is particularly remarkable when the entire surface is white or the entire surface is green. This luminance unevenness is considered to be caused by the transmitted light interfering with the unevenness of the antiglare layer. In this way, in the anti-glare film, the anti-glare property is obtained due to the unevenness of the anti-glare layer, but since the unevenness of luminance occurs due to the unevenness, it is difficult to achieve both excellent anti-glare property and suppression of luminance unevenness.

As a method of solving this problem, a method of adjusting the difference between the refractive index of the resin constituting the anti-glare layer of the anti-glare layer and the refractive index of the fine particles contained in the anti-glare layer within a predetermined range is disclosed (for example, Patent Document See 1-3).

Japanese Unexamined Patent Publication No. 11-326608 Japanese Unexamined Patent Publication No. 2008-262190 Japanese Unexamined Patent Publication No. 2009-175375

However, in the methods of Patent Documents 1 to 3, there is a limit to suppressing luminance unevenness while maintaining excellent anti-glare properties, and there is room for improvement.

The present invention has been made in view of the above problems, and a photocurable resin composition capable of forming a cured film having excellent anti-glare properties and less luminance unevenness, a cured film and an anti-glare film, and a method for producing a cured film and an anti-glare film It aims to provide.

According to an aspect of the present invention,

As a photocurable resin composition containing a photopolymerizable component (A), fine particles (B) and a photopolymerization initiator (C),

The photopolymerizable component (A) contains a photopolymerizable (meth)acrylic resin (a1) having a weight average molecular weight of 10,000 or more,

The fine particles (B) contain polyorgano silsesquioxane fine particles containing aluminum oxide fine particles having an average particle diameter of 1.0 μm or more and 2.8 μm or less,

A photocurable resin composition having a viscosity at 23°C of 1 mPa·s or more and 1000 mPa·s or less is provided.

According to another aspect of the present invention,

A cured film formed of the photocurable resin composition of the above-described aspect and having irregularities due to the fine particles (B) on its surface is provided.

According to another aspect of the present invention,

An anti-glare film provided with a transparent base material and the cured film of the above-described aspect is provided.

According to another aspect of the present invention,

An image display device provided with the anti-glare film of the above aspect is provided.

According to another aspect of the present invention,

There is provided a method for producing a cured film having a curing step of curing the photocurable resin composition of the above aspect by irradiation with light.

According to another aspect of the present invention,

A coating step of applying the photocurable resin composition of any one of the first to fourth aspects to at least one main surface of the transparent substrate, and

After the coating step, there is provided a method for producing an anti-glare film having a curing step of curing the photocurable resin composition by light irradiation to form a cured film.

According to the present invention, a photocurable resin composition, a cured film and a film capable of forming an anti-glare film having excellent anti-glare properties and less luminance unevenness are obtained.

1 is a schematic diagram showing a part of a cross section of an anti-glare film according to an embodiment of the present invention.
2 is a schematic diagram showing a part of a cross section of a conventional anti-glare film.

In order to solve the above-described problems, the inventors studied, and it was found that the causes of luminance unevenness in a conventional anti-glare film are mainly the following two points.

One is that the unevenness of the anti-glare layer is not densely formed inside the surface. As shown in Fig. 2, in the antiglare layer 110, the convex portion 111 is formed on the surface by the presence of the fine particles (B) at a predetermined position in the thickness direction, but conventionally, the fine particles (B) are used as the antiglare layer. (110) There may be a case where the portion 112 is settled inside and the convex portion is not partially formed. Therefore, the convex portions 111 are sparsely distributed inside the surface of the anti-glare layer 110, and the average interval Sm of the irregularities in the anti-glare layer 110 is large.

Another thing is that the surface roughness due to irregularities is large. As shown in Fig. 2, in the anti-glare layer 110, the surface roughness Ra is determined by the height of the convex portion 111 on the surface. As a result, there may be a case where the height of the convex portion is excessively large (113). Accordingly, the surface roughness Ra of the anti-glare layer 110 is large.

As described above, when the average interval Sm of the irregularities in the antiglare layer 110 and the surface roughness Ra increase, the transmitted light from the display is likely to interfere with the irregularities, or luminance unevenness tends to occur. From this, in order to reduce the luminance unevenness while maintaining excellent anti-glare properties in the anti-glare layer 110, it is understood that the average spacing Sm of the unevenness and the surface roughness Ra due to the unevenness may be made small.

Therefore, the present inventors studied a method of suppressing sedimentation and aggregation of fine particles in the photocurable resin composition for forming the antiglare layer in order to reduce the average spacing Sm of the irregularities and the surface roughness Ra due to the irregularities. . Specifically, a method of suppressing the sedimentation and aggregation of fine particles having an average particle diameter of 1.0 to 2.8 µm was examined so that desired unevenness can be formed and a predetermined anti-glare property can be obtained.

First of all, the present inventors examined by setting the viscosity of a photocurable resin composition high. This is because, in general, when the viscosity is high, sedimentation or aggregation of fine particles dispersed in the photocurable resin composition becomes difficult to occur. As a result of the examination, when the viscosity at 23°C is in the range of 1 mPa·s or more and 1000 mPa·s or less, sedimentation and aggregation of fine particles can be suppressed, but the photopolymerizable (meth)acrylic resin contained in the photocurable resin composition It was found that when the molecular weight of was low, sedimentation and aggregation could not be sufficiently suppressed. That is, in order to suppress sedimentation and aggregation of fine particles, it was found that only adjusting the viscosity was insufficient, and it was necessary to increase the molecular weight of the photopolymerizable (meth)acrylic resin.

The molecular weight of the photopolymerizable (meth)acrylic resin was further investigated. When the weight average molecular weight is less than 10,000, sedimentation and aggregation of the fine particles cannot be sufficiently suppressed even if the viscosity is within the above range, but the weight average molecular weight is When it was 10,000 or more, it turned out that it can suppress satisfactorily.

As a factor of this, the present inventor estimates as follows. In general, it is known that the lower the molecular weight, the shorter the molecular chain of the resin component, and the higher the molecular weight, the longer the molecular chain. According to the resin component having a high molecular weight and a long molecular chain, the size is larger than that of a resin component having a low molecular weight and a short molecular chain, so that it is easy to capture fine particles having a predetermined average particle diameter. Therefore, in a photocurable resin composition containing a high molecular weight resin component, fine particles are trapped and sedimentation is suppressed, so that they are easy to float. Moreover, since the fine particles are trapped and agglomeration of fine particles is suppressed, they can be finely dispersed. Therefore, in the anti-glare layer formed therefrom, sedimentation and aggregation of fine particles are suppressed, and the average spacing Sm of the irregularities and the surface roughness Ra due to the irregularities are made small. That is, according to the above configuration, it is possible to form a cured film having excellent anti-glare properties and less luminance unevenness.

The present invention has been achieved based on the above findings.

Hereinafter, an embodiment of the present invention will be described in the following order.

1. Photocurable resin composition

1-1. Photopolymerizable component (A)

1-2. Particulate (B)

1-3. Photopolymerization initiator (C)

1-4. Viscosity

1-5. Other additives

1-6. Preparation method

2. Anti-glare film

3. Manufacturing method of anti-glare film

4. Effects of this embodiment

<1. Photocurable resin composition>

The photocurable resin composition according to the present embodiment is obtained by mixing a photopolymerizable component (A), fine particles (B), and a photopolymerization initiator (C), and has a viscosity at 23°C of 1 mPa·s or more and 1000 mPa·s or less. .

<1-1. Photopolymerizable component (A)>

The photopolymerizable component (A) contains a photopolymerizable (meth)acrylic resin (a1) having a weight average molecular weight of 10,000 or more (hereinafter, simply referred to as "(meth)acrylic resin (a1)"). At this time, in this specification, (meth)acryl represents at least any one of acrylic and methacryl corresponding to it.

The (meth)acrylic resin (a1) is a resin component having a polymer of a (meth)acrylic monomer as a main skeleton and a photopolymerizable functional group in the side chain. As a photopolymerizable functional group, a (meth)acryloyl group, a vinyl group, an allyl group, etc. are mentioned, for example. Among them, since the reactivity is high and the curing rate by light irradiation is fast, a (meth)acryloyl group is preferable.

The weight average molecular weight of the (meth)acrylic resin (a1) is 10,000 or more, preferably 15,000 or more. As described above, when the weight average molecular weight is less than 10,000, the sedimentation and aggregation of the fine particles (B) in the photocurable resin composition cannot be sufficiently suppressed. The resulting surface roughness Ra increases, and luminance unevenness tends to occur. In the cured film, from the viewpoint of improving the appearance by preventing the occurrence of defects such as aggregates and dents while reducing the average spacing Sm of the irregularities and the surface roughness Ra due to the irregularities, it is preferable that the weight average molecular weight is large, It should be 15,000 or more. At this time, the upper limit of the weight average molecular weight is not particularly limited, but is preferably 200,000 or less, more preferably 100,000 or less, and still more preferably 60,000 or less. By setting it as such a weight average molecular weight, in a cured film, flexibility, flexibility, etc. are not impaired, and desired high hardness can be obtained. At this time, in this embodiment, the weight average molecular weight is calculated from the measurement result of gel permeation chromatography (GPC) using polystyrene as a standard.

It is preferable that the photopolymerizable component (A) contains a (meth)acrylate-based monomer and/or a (meth)acrylate-based resin (a2) as components other than the (meth)acrylic resin (a1). By containing such a (meth)acrylate-based monomer and/or a (meth)acrylate-based resin (a2), the hardness and scratch resistance of the cured film can be improved.

As the (meth)acrylate-based monomer, for example, one having two or more polymerizable functional groups in the monomer can be used. Specifically, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, tri Bifunctional monomers such as ethylene glycol di (meth) acrylate and tetraethylene glycol di (meth) acrylate: trimethylolpropane tri (meth) acrylate, tris (2- (meth) acryloyloxyethyl isocyanurate , Tris(2-(meth)acryloyloxypropyl)isocyanurate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol Polyfunctional monomers such as penta(meth)acrylate and dipentaerythritol hexa(meth)acrylate, etc. Among these, from the viewpoint of improving the hardness of the cured film, the monomer has 4 or more polymerizable functional groups. Functional monomers are particularly preferred These (meth)acrylate-based monomers can be used alone or in combination of two or more.

In addition, as a (meth)acrylate-based resin, for example, photocurable (meth)acrylate, polyester (meth)acrylate, polyether (meth)acrylate, epoxy (meth)acrylate, etc. ) A resin obtained by polymerizing an acrylate-based monomer is mentioned. These (meth)acrylate-based resins can be used alone or in combination of two or more.

The blending amount of the (meth)acrylate-based monomer and/or (meth)acrylate-based resin (a2) is 0 mass per 100 parts by mass of the solid content of the photocurable resin composition from the viewpoint of not excessively improving the hardness of the cured film. Parts by mass or more and 40 parts by mass or less are preferable, and 0 parts by mass or more and 20 parts by mass or less are more preferable. At this time, in the present embodiment, the solid content refers to a component which excludes volatile components such as organic solvents from the photocurable resin composition, and remains as a cured film when cured.

<1-2. Particles (B)>

When the photocurable resin composition is cured, the fine particles (B) form irregularities on the surface of the cured film (glare layer). As the fine particles (B), those having an average particle diameter of 1.0 µm or more and 2.8 µm or less can be used. When the average particle diameter of the fine particles (B) is less than 1.0 µm, when the photocurable resin composition is cured, the height of the convex portion in the antiglare layer is small, and the surface roughness Ra thereof becomes excessively small. Therefore, reflection cannot be sufficiently suppressed due to irregularities, and high anti-glare properties cannot be obtained. On the other hand, when the average particle diameter exceeds 2.8 µm, the height of the convex portion of the anti-glare layer increases, and the surface roughness Ra becomes excessively large. Therefore, non-uniformity in luminance occurs in the anti-glare layer, resulting in a decrease in visibility. At this time, in this embodiment, the average particle diameter represents a median diameter (D50).

As the fine particles (B), conventionally known fine particles can be used. For example, acrylic fine particles, polystyrene fine particles, polyethylene wax fine particles, polypropylene wax fine particles, PTFE fine particles, urethane fine particles, silicone fine particles, etc. can be used as the organic fine particles. Further, for example, as the inorganic fine particles, metal oxide fine particles such as silicon dioxide fine particles, aluminum oxide fine particles, zirconium oxide fine particles, zinc oxide fine particles, and titanium oxide fine particles can be used. These may be used individually by 1 type, and may use 2 or more types together. As the fine particles (B), it is preferable to use silicon fine particles which are organic fine particles from the viewpoint of more suppressing the luminance unevenness. Silicon fine particles containing alumina fine particles are more preferable from the viewpoint of suppressing non-uniformity in luminance and improving anti-glare properties by suppressing reflection. Silicon fine particles containing alumina fine particles have superior light diffusivity compared to silicon fine particles, and can further improve anti-glare properties.

The blending amount of the fine particles (B) can be appropriately changed according to various properties such as anti-glare property, scratch resistance, and transparency (turbidity) required for the cured film. When the photocurable resin composition is applied to an antiglare film attached to a screen of an image display device, since it is necessary to have a good balance of various properties, the blending amount of the fine particles (B) is 100 parts by mass of the solid content of the photocurable resin composition. With respect to, 0.1 parts by mass or more and 20 parts by mass or less are preferable, and 4 parts by mass or more and 10 parts by mass or less are more preferable. If the blending amount of the fine particles (B) is less than the above range, there is a fear that various properties cannot be obtained in a good balance, and if it is greater than the above range, the turbidity of the cured film is increased and transparency may be impaired.

<1-3. Photoinitiator (C)>

The photopolymerization initiator (C) generates a radical or a cation by light irradiation to cure the photopolymerizable component (A). As a photoinitiator (C), what is necessary is just to be able to harden the photopolymerizable component (A). For example, a benzoin photoinitiator, an acetophenone photoinitiator, a benzophenone photoinitiator, a thioxanthone photoinitiator, and the like can be used.

As a benzoin type photoinitiator, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, etc. are mentioned.

As an acetophenone-based photoinitiator, benzyl dimethyl ketal (another name, 2,2-dimethoxy-2-phenylacetophenone), diethoxyacetophenone, 4-phenoxydichloroacetophenone, 4-t-butyl-dichloro acetophenone, 4-t-Butyl-trichloroacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropane-1 -One, 1-(4-dodecylphenyl)-2-hydroxy-2-methylpropan-1-one, 4-(2-hydroxyethoxy)-phenyl(2-hydroxy-2-propyl)ketone , 1-hydroxycyclohexylphenyl ketone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, and the like.

As a benzophenone-based photoinitiator, benzophenone, benzoylbenzoic acid, methyl benzoylbenzoate, 4-phenylbenzophenone, hydroxybenzophenone, acrylated benzophenone, 4-benzoyl-4'-methyl diphenyl sulfide, 3,3'-dimethyl And -4-methoxybenzophenone.

As a thioxanthone photoinitiator, thioxanthone, 2-chloro thioxanthone, 2-methyl thioxanthone, 2,4-dimethyl thioxanthone, isopropyl thioxanthone, 2,4-dichloro thioxanthone, 2,4-diethyl thioxanthone, 2,4-diisopropyl thioxanthone, and the like.

These photoinitiators may be used individually by 1 type, and may use 2 or more types together.

The blending amount of the photopolymerization initiator (C) is preferably 0.1 parts by mass or more and 10 parts by mass or less, and more preferably 3 parts by mass or more and 6 parts by mass or less, based on 100 parts by mass of the solid content of the photocurable resin composition. If the blending amount is less than the above range, there is a concern that the rate (curing rate) at the time of curing the photocurable resin composition may be slowed, and if it is more than the above range, the curing rate may be excessively accelerated.

<1-4. Viscosity>

The viscosity of the photocurable resin composition according to the present embodiment is 1 mPa·s or more and 1000 mPa·s or less at 23°C. It is preferably 1 to 500 mPa·s, more preferably 3 to 60 mPa·s, and still more preferably 3 to 40 mPa·s. When the viscosity is less than 1 mPa·s, the viscosity becomes excessively low, so that the fine particles (B) settle or aggregate in the photocurable resin composition. On the other hand, when the viscosity exceeds 1000 mPa·s, since the leveling property of the photocurable resin composition is low, it becomes difficult to apply, and a cured film having a uniform film thickness cannot be formed.

<1-5. Other additives>

In the photocurable resin composition according to the present embodiment, if necessary, other additives other than the above-described components may be contained. As other additives, from the viewpoint of adjusting the viscosity to a predetermined range, an organic solvent may be contained. As the organic solvent, a conventionally known one can be used. For example, aromatic hydrocarbons (e.g. xylene, toluene, etc.), ketones (e.g. methyl isobutyl ketone, methyl ethyl ketone, cyclohexanone, etc.), esters (e.g. ethyl acetate, butyl acetate, isobutyl acetate, etc.) ), alcohols (eg, isopropyl alcohol, butanol, etc.), glycol ethers (eg, propylene glycol monomethyl ether, etc.), and various organic solvents. These organic solvents can be used alone or in combination of two or more.

Moreover, you may contain a leveling agent as another additive. According to the leveling agent, it is possible to improve the dents of the photocurable resin composition, improve wettability to the surface to be coated, and form a cured film having a uniform film thickness. Examples of the leveling agent include various leveling agents such as fluorine-based, acrylic-based, and silicone-based. Among these, a fluorine-based leveling agent is more preferable because it not only improves the leveling property, but also can impart a contamination prevention function such as water and oil repellency. The blending amount of these leveling agents is preferably 0.1 parts by mass or more and 1.5 parts by mass or less, and more preferably 0.5 parts by mass or more and 1.0 parts by mass or less, based on 100 parts by mass of the solid content of the photocurable composition.

Further, as another additive, a defoaming agent may be contained. According to the antifoaming agent, generation of air bubbles in the photocurable resin composition can be suppressed, and the appearance of the cured film can be improved. Examples of the antifoaming agent include various antifoaming agents such as acrylic and silicone. The blending amount of these antifoaming agents is preferably 0.0001 parts by mass or more and 1.0 parts by mass or less with respect to 100 parts by mass of the solid content of the photocurable composition.

Further, as other additives, a polymerization inhibitor, a non-reactive diluent, a matting agent, an anti-settling agent, a dispersant, a heat stabilizer, an ultraviolet absorber, and the like may be contained. These blending amounts can be appropriately changed within a range that does not impair the effects of the present embodiment.

<1-6. Preparation method>

The photocurable resin composition according to the present embodiment is prepared, for example, as follows.

First, a photopolymerizable component (A), a photopolymerization initiator (C), and other additives as necessary are dissolved in an organic solvent. Next, the photocurable resin composition of the present embodiment is obtained by adding and stirring the fine particles (B) to the obtained solution. At this time, at the time of preparation, the amount of the photopolymerizable component (A), fine particles (B), organic solvent, and the like may be appropriately changed so that the viscosity of the photocurable resin composition is within a predetermined range.

<2. Anti-glare film>

Next, the anti-glare film 1 formed using the photocurable resin composition described above will be described using FIG. 1. 1 is a schematic diagram showing a cross section of an anti-glare film 1 according to an embodiment of the present invention.

As shown in FIG. 1, the anti-glare film 1 according to the present embodiment is configured with a transparent substrate 20 and a cured film (anti-glare layer) 10.

As the transparent substrate 20, a transparent plastic film made of a transparent material can be used. As a transparent plastic film, for example, a triacetyl cellulose film, a polyethylene terephthalate (PET) film, a diacetyl cellulose film, an acetate butyrate cellulose film, a polyethersulfone film, a polyacrylic resin film, a polyurethane resin film, polyester A film, a polycarbonate film, a polysulfone film, a polyether film, a polymethylpentene film, a polyether ketone film, a (meth)acrylonitrile film, etc. are mentioned. Among these, a polyethylene terephthalate film is preferable from the viewpoint of the balance of strength and optical properties.

The cured film (antiglare layer) 10 is provided on one main surface of the transparent substrate 20. The cured film 10 is formed of a photocurable resin composition, and has irregularities due to fine particles (B) on its surface. As described above, in the photocurable resin composition, sedimentation and aggregation of the fine particles (B) are suppressed. Therefore, when the photocurable resin composition is applied, in the coating film, the fine particles (B) do not settle and float in the thickness direction, and are finely dispersed without aggregation. In the cured film 10 obtained by curing this coating film, sedimentation of the fine particles (B) is suppressed, and the convex portions 11 by the fine particles (B) are uniformly formed inside the surface, so that the distribution of irregularities is dense. It is supposed to be done. In addition, since the convex portion 11 is formed so that the aggregation of the fine particles B is suppressed and the height of the convex portion 11 is not excessively large, the surface roughness due to irregularities in the cured film 10 is reduced. have.

Specifically, in the cured film 10, the irregularities are densely formed, and the average interval Sm of the irregularities is preferably 30 µm or more and 300 µm or less, and more preferably 40 µm or more and 200 µm or less. The average spacing Sm represents the average of the distances between the convex portions 11, and as the average spacing Sm increases, the density of the convex portions 11 decreases. When the average interval Sm exceeds 300 µm, irregularities in luminance are suppressed because irregularities become sparse, but it becomes difficult to obtain excellent anti-glare properties.

In addition, in the cured film 10, the surface roughness Ra due to irregularities is preferably 0.01 µm or more and 0.17 µm or less, and more preferably 0.05 µm or more and 0.15 µm or less. When the surface roughness Ra is less than 0.01 µm, excellent anti-glare properties cannot be obtained, and when it exceeds 0.17 µm, there is a fear that luminance unevenness cannot be sufficiently suppressed.

The anti-glare film 1 according to the present embodiment can be particularly preferably used on the most surface of a tablet terminal, but can also be applied to displays such as televisions other than that.

At this time, the cured film 10 may be formed not only on one side of the transparent substrate 20 but also on both sides. Further, another layer (not shown) may be formed between the transparent substrate 20 and the cured film 10. As another layer, a polarizing layer, a light diffusion layer, a low reflection layer, a contamination prevention layer, an antistatic layer, an ultraviolet/near infrared (NIE) absorption layer, a neon cut layer, an electromagnetic wave shield layer, etc. are mentioned, for example. Further, a coating layer (not shown) such as a contamination prevention layer may be formed on the surface of the cured film 10.

<3. Manufacturing method of anti-glare film>

Next, the manufacturing method of the anti-glare film 1 mentioned above is demonstrated. The anti-glare film 1 is manufactured by the following process, for example.

(Preparation process)

First, as the transparent substrate 20, a PET film having a thickness of, for example, 100 μm is prepared.

(Application process)

Next, a photocurable resin composition is applied on one main surface of the transparent substrate 20 to form a coating film. The thickness of the coating film (applied thickness of the photocurable resin composition) at this time varies depending on the properties required for the cured film (glare layer) 10, but, for example, the thickness of the cured film 10 is at least 1 μm, preferably. Adjust it so that it is 2㎛ or more. On the other hand, the upper limit of the thickness of the cured film is not particularly limited, but from the viewpoint of the handleability of the anti-glare film 1, for example, the thickness of the coating film may be adjusted to be 4 µm or less, preferably 3 µm or less. .

The application method can be appropriately changed according to the type or composition of the photocurable resin composition, the type of the transparent substrate 20 to be applied, and the like. For example, a spray coating method, a dip coating method, an air knife coating method, a curtain coating method, a roller coating method, a wire barcode method, a gravure coating method, an extrusion coating method, and the like can be mentioned. Among these, the spray coating method is preferable from the viewpoint of workability and productivity.

(Light irradiation process)

Subsequently, the coating film is irradiated with light with an active energy ray. As the active energy rays, in addition to rays such as far ultraviolet rays, ultraviolet rays, near ultraviolet rays, and infrared rays, electromagnetic waves such as X-rays and γ rays, electron rays, proton rays, neutron rays, and the like can be exemplified. From the viewpoint of ease, price, etc., ultraviolet rays are preferred. As a method of curing with ultraviolet rays, a method of irradiating about 100 to 3000 mJ/cm 2 using a high-pressure mercury lamp, metal halide lamp, xenon lamp, chemical lamp, etc. that generate light in a wavelength range of 200 to 500 nm, etc. .

The photocurable resin composition is cured by light irradiation for a predetermined period of time to form a cured film 10. Thereby, the anti-glare film 1 according to the present embodiment is obtained.

At this time, in this embodiment, a drying step for drying the photocurable resin composition may be provided between the coating step and the light irradiation step. Examples of the drying method include vacuum drying or heat drying, and further, a method of combining these dryings.

<4. Effects related to the embodiment of the present invention>

According to this embodiment, one or more effects shown below are exhibited.

According to the photocurable resin composition of the present embodiment, using a (meth)acrylic resin (a1) having a weight average molecular weight of 10,000 or more and fine particles (B) having an average particle diameter of 1.0 µm or more and 2.8 µm or less, at 23°C. The viscosity is configured to be 1 mPa·s or more and 1000 mPa·s or less. Thereby, since sedimentation of the fine particles (B) in the photocurable resin composition can be suppressed, in the cured film 10 formed therefrom, the convex portions 11 by the fine particles (B) are formed densely. , The average spacing Sm of irregularities can be made small, for example, in the range of 30 to 300 µm. At the same time as +, since the aggregation of the fine particles (B) can be suppressed, the convex portions 11 due to the fine particles (B) can be formed so as not to be excessively large, so that the surface roughness Ra of the cured film 10 is reduced, For example, it can be configured in the range of 0.01 to 0.17 µm. Therefore, according to the present embodiment, it is possible to form a cured film 10 having excellent anti-glare properties and less luminance unevenness, and an anti-glare film 1 provided with the same.

In addition, in this embodiment, as the fine particles (B), silicon fine particles containing alumina fine particles may be used. Since silicon fine particles containing alumina fine particles have superior light diffusivity compared to silicon fine particles or the like, the anti-glare property of the cured film 10 can be further improved.

In addition, in the present embodiment, the fine particles (B) may be contained within a range of 0.1 to 20 parts by mass per 100 parts by mass of the solid content. Thereby, while the scratch resistance of the cured film 10 is obtained, an increase in turbidity due to the fine particles (B) can be suppressed to ensure transparency.

In addition, in this embodiment, as the photopolymerizable component (A), in addition to the (meth)acrylic resin (a1), it is sufficient to contain a (meth)acrylate-based monomer and/or a (meth)acrylate-based resin (a2). . Accordingly, the hardness of the cured film 10 can be improved, and scratch resistance can be further improved.

In addition, in this embodiment, the cured film 10 has excellent anti-glare properties, and preferably, a 60° mirror glossiness measured in accordance with JIS K5600-4-7, which is an index of anti-glare properties, is 120% or less. Becomes.

In addition, in this embodiment, the anti-glare film 1 provided with the cured film 10 is excellent in transparency, and the turbidity measured in conformity with JIS K7136 which is an index of transparency is 40% or less.

In addition, in the present embodiment, since the anti-glare film 1 is provided with a cured film 10 having excellent anti-glare properties and less luminance unevenness, it is possible to suppress the reflection of light on the screen and the glare of the screen. have. That is, the anti-glare film 1 is excellent in visibility. Specifically, in accordance with JIS K7374, the sum of the image sharpness measured using an optical comb having a slit width of 0.125 mm, 0.25 mm, 0.5 mm, 1.0 mm and 2.0 mm is 350% or more. , Excellent visibility.

[Example]

Next, the present invention will be described in more detail based on Examples, but the present invention is not limited to these Examples.

<Example 1>

[Raw material]

The raw materials used are as follows.

As a photopolymerizable component (A),

A photopolymerizable (meth)acrylic resin (a1) whose main skeleton is acrylic and has a (meth)acryloyl group as a photopolymerizable functional group in the side chain and has a weight average molecular weight (Mw) of 40,000 (manufactured by Taisei Fine Chemical Co., Ltd. -078", solid content 40%) was used.

As fine particles (B),

Alumina fine particles encapsulated silicon fine particles (alumina fine particles enclosed polyorgano silsesquioxane fine particles: solid content 100%) having an average particle diameter of 1.9 µm were used. At this time, the average particle diameter was measured under the following conditions using a laser diffraction type particle diameter distribution measuring device ("SALD-2200" manufactured by Shimadzu Corporation).

Dispersion medium: water

Dispersant: Sodium hexamethaphosphate

Spin speed: 7

Ultrasonic dispersing time: 10 minutes

As a photoinitiator (C),

1-hydroxycyclohexyl phenyl ketone (BASF Corporation ``Ilgacure 184D'', solid content 100%) and 2,4,6-trimethylbenzoyl diphenyl phosphine oxide (BASF Co., Ltd. ``Ilgacure TPO'', solid content 100%) ) Was used.

As other additives,

Hydroquinone (manufactured by Mitsui Chemical Co., Ltd., 100% solid content), which is a polymerization inhibitor,

Silicone antifoaming agent (BYK Co., Ltd. ``BYK-066N'', solid content 1%),

Fluorine-based leveling agent (DIC Co., Ltd. ``Megapak ES-75'', solid content 40%),

Methyl ethyl ketone, an organic solvent, was used.

[Preparation of photocurable resin composition]

As shown in Table 1 below, by blending the above raw materials, a photocurable resin composition of Example 1 was prepared.

Specifically, as a photopolymerizable component (A), 67.0 parts by mass of a photopolymerizable acrylic resin (a1) having a weight average molecular weight (Mw) of 40,000 was added to 29.3 parts by mass of methyl ethyl ketone, and (C) as a photopolymerization initiator, monovalent 0.6 parts by mass of Cure 184D, 0.6 parts by mass of Ilga Cure TPO, and 0.02 parts by mass of hydroquinone, 0.02 parts by mass of a silicone antifoaming agent, and 0.7 parts by mass of a fluorine-based leveling agent were added and dissolved as other additives. Then, 1.8 parts by mass of encapsulated silicon fine particles of alumina fine particles having an average particle diameter of 1.9 µm were added to the solution and stirred. Thereby, a photocurable resin composition in which fine particles (B) were dispersed was obtained.

About the prepared photocurable resin composition, when the viscosity at 23 degreeC was measured using a viscometer ("HAAKE Viscotester 6 plus" manufactured by ThermoFisher Scientific Co., Ltd.), it was confirmed that it was 16 mPa·s.

[Production of anti-glare film]

Next, an anti-glare film was produced using the photocurable resin composition obtained above.

First, as a transparent substrate, a PET film ("Cosmo Shine A4300" manufactured by Toyobo Co., Ltd., 200 mm long x 150 mm wide x 100 µm thick) was prepared. Next, the photocurable resin composition prepared above was applied to one main surface of the PET film to form a coating film. At this time, it applied by adjusting the thickness of a coating film so that the film thickness (dry film thickness) of the obtained cured film might become 2-3 micrometers. Next, using a high-pressure mercury lamp, ultraviolet rays were irradiated to the coating film (irradiation amount: 300 to 400 mJ/cm 2 ). The coating film was cured by irradiation, a cured film having a thickness of 2.0 µm was formed, and an anti-glare film of this example was produced.

About the obtained anti-glare film, when the average interval Sm of the irregularities in the cured film and the surface roughness Ra due to the irregularities were measured, it was confirmed that the average interval Sm was 49.6 µm and the surface roughness Ra was 0.11 µm. At this time, the average spacing Sm and the surface roughness Ra were measured using an ultra-small surface roughness measuring instrument E-35B manufactured by Tokyo Precision Co., Ltd.).

[Assessment Methods]

Next, the following evaluation was performed about the obtained anti-glare film.

(Anti-glare)

According to JIS K5600-4-7, the glossiness of a 60 degree mirror surface was measured, and the anti-glare property of an anti-glare film was evaluated. In this example, when the glossiness on a 60° mirror surface was 120% or less, it was evaluated as having excellent anti-glare properties.

(Uneven luminance)

The degree of luminance unevenness was evaluated by visually judging the glare of the image projected on the anti-glare film. Specifically, using "iPad (registered trademark)" as an image display device, setting the display display to green in the application software "Free Light", and placing an anti-glare film on the display so that the cured film surface is on the surface side. When pressed, the glare of the image was judged with the naked eye. In this example, the degree of glare was classified into the following levels, and when the level was 3 or more, it was evaluated that there was little luminance unevenness.

5: no glare

4: almost no glare

3: There is some flashing, but it is an acceptable range

2: There is a lot of flash

1: There is a lot of glare

(Turbidity)

According to JIS K7136, the turbidity (haze: HZ) of the anti-glare film was measured and evaluated. In this example, when the turbidity was 40% or less, the image visibility was excellent, and when it was 20% or less, it was evaluated as being particularly excellent. At this time, the turbidity was measured using a haze meter NDH 2000 (manufactured by Nippon Denshoku Industries, Ltd.).

(Total light transmittance)

According to JIS K7361, the total light transmittance (TT) of the anti-glare film was measured and evaluated. In this example, if the total light transmittance was 85% or more, it was evaluated that the transmittance was high. At this time, the total light transmittance was measured using a haze meter NDH2000 (manufactured by Nippon Tenshoku Industries, Ltd.).

(Image clarity)

The image sharpness is a numerical evaluation of how clearly the image that can be observed through the anti-glare film is seen, and is measured in accordance with JIS K7374. In this example, in accordance with JIS K7374, evaluation by the total value of the image sharpness measured using five types of optical combs (slit widths: 0.125 mm, 0.25 mm, 0.5 mm, 1 mm and 2 mm) with different slit widths And, if the total value was 350% or more, it was evaluated that the image was clearly visible. At this time, the image sharpness was measured using the fidelity measuring instrument ICM-1T (manufactured by Suga Test Instruments Co., Ltd.).

(Hardness)

In accordance with JIS K5600, a pencil hardness test was performed under a load of 750 g, and the pencil hardness of the anti-glare film was measured and evaluated. In this example, if the pencil hardness was H or more, it was evaluated as having sufficient hardness and excellent scratch resistance.

(Exterior)

The anti-glare film is tilted 45° with the cured film facing upward, and the cured film is visually observed over the transparent substrate, and the presence or absence of aggregates of fine particles on the surface of the cured film, the presence or absence of dents, and the uniformity of the surface. Evaluated. In this example, the appearance was evaluated as having a good appearance without agglomerates and dents, and having a uniform surface.

<Example 2>

In Example 2, as the photopolymerizable (meth)acrylic resin (a1), a photocurable resin composition was prepared in the same manner as in Example 1, except that the one having a weight average molecular weight of 10,000 was used to prepare an anti-glare film.

<Example 3>

In Example 3, as the photopolymerizable (meth)acrylic resin (a1), a photocurable resin composition was prepared in the same manner as in Example 1, except that one having a weight average molecular weight of 20,000 was used to prepare an anti-glare film.

<Example 4>

In Example 4, as the photopolymerizable (meth)acrylic resin (a1), a photocurable resin composition was prepared in the same manner as in Example 1, except that one having a weight average molecular weight of 80,000 was used to prepare an antiglare film.

<Example 5>

In Example 5, as the fine particles (B), a photocurable resin composition was prepared in the same manner as in Example 1, except that silicon fine particles having an average particle diameter of 2.0 µm were used to prepare an anti-glare film.

<Example 6>

In Example 6, as the photopolymerizable component (A), except for using a (meth)acrylate-based monomer (a2) together with a photopolymerizable (meth)acrylic resin (a1), and appropriately changing the blending amount, Examples In the same manner as in 1, a photocurable resin composition was prepared. In this example, a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (100% solid content) was used as the (meth)acrylate-based monomer (a2).

<Example 7>

In Example 7, as the fine particles (B), a photocurable resin composition was prepared in the same manner as in Example 6, except that acrylic fine particles having an average particle diameter of 1.2 µm were used to prepare an anti-glare film.

<Example 8>

In Example 8, as the fine particles (B), a photocurable resin composition was prepared in the same manner as in Example 6, except that acrylic fine particles having an average particle diameter of 2.3 µm were used to prepare an anti-glare film.

<Example 9>

In Example 9, as the fine particles (B), a photocurable resin composition was prepared in the same manner as in Example 6, except that hydrophobic silica fine particles having an average particle diameter of 2.1 µm were used to prepare an anti-glare film.

<Comparative Example 1>

In Comparative Example 1, as shown in Table 2 below, as the photopolymerizable component (A), a photopolymerizable (meth)acrylic resin (a1) was not used, and a urethane acrylate resin having a weight average molecular weight of 900 (solid content 40% ) Was used, and a photocurable resin composition was prepared in the same manner as in Example 1, except that the blending amount was appropriately changed, and an anti-glare film was produced.

<Comparative Example 2>

In Comparative Example 2, as the fine particles (B), a photocurable resin composition was prepared in the same manner as in Example 6, except that the alumina fine particles encapsulated silicone fine particles having an average particle diameter of 3.0 µm were used to prepare an anti-glare film.

<Comparative Example 3>

In Comparative Example 3, as the fine particles (B), a photocurable resin composition was prepared in the same manner as in Example 6, except that acrylic fine particles having an average particle diameter of 3.0 µm were used to prepare an anti-glare film.

<Comparative Example 4>

In Comparative Example 4, as the fine particles (B), a photocurable resin composition was prepared in the same manner as in Example 6, except that acrylic fine particles having an average particle diameter of 0.7 µm were used to prepare an anti-glare film.

<Comparative Example 5>

In Comparative Example 5, as the fine particles (B), a photocurable resin composition was prepared in the same manner as in Example 6, except that acrylic fine particles having an average particle diameter of 0.8 μm were used to prepare an anti-glare film.

As shown in Table 1, in the anti-glare films of Examples 1 to 9, it was confirmed that the average spacing Sm of the irregularities was 30 to 300 µm, and the surface average roughness Ra was 0.01 to 0.17 µm. In Examples 1 to 9, it was confirmed that the glossiness was 120% or less on a 60° mirror surface, and was excellent in anti-glare properties. Moreover, the level of the degree of glare was 3 or more, and there were few luminance unevenness. Further, it was confirmed that it was excellent also in turbidity, total light transmittance, image clarity, and hardness.

When comparing Examples 1, 3 to 9 and Example 2, in Examples 1 and 3 to 9, since a photopolymerizable acrylic resin (a1) having a weight average molecular weight of 15,000 or more was used, light weight having a weight average molecular weight of 10,000 It was confirmed that the appearance of the cured film could be improved more than in Example 2 in which the synthetic acrylic resin (a1) was used.

When comparing Example 1 and Example 5, in Example 1 using silicon fine particles containing alumina fine particles as the fine particles (B), the glossiness can be reduced if it is 60° mirrored than Example 5 using silicon fine particles. , It was confirmed that the anti-glare property is more excellent. This is presumed to be because the alumina microparticle-encapsulated silicon microparticles are superior to the silicon microparticles in light diffusivity.

When comparing Examples 1 to 5 and Examples 6 to 9, in Examples 6 to 9, since the acrylate monomer (a2) was used, the hardness of the cured film can be made higher than that of Examples 1 to 5. Was confirmed.

As shown in Table 2, in Comparative Example 1, the average spacing Sm of the irregularities was large at 354.3 µm, and it was confirmed that the convex portions due to the fine particles (B) were not formed densely. As a result, it was confirmed that the glossiness was as high as 141% when the mirror was 60°, and the anti-glare property was inferior. This is presumed to be due to the precipitation of the fine particles (B) in the anti-glare layer because a urethane acrylate resin having a low weight average molecular weight was used.

In Comparative Examples 2 and 3, since the fine particles (B) having an average particle diameter larger than 2.8 µm were used, it was confirmed that the surface roughness Ra was larger than 0.17 µm. As a result, it was confirmed that the luminance unevenness increased and the image sharpness decreased.

In Comparative Examples 4 and 5, as the fine particles (B), those having an average particle diameter smaller than 1.0 µm were used, and it was confirmed that the average spacing Sm was larger than 300 µm. As a result, although the luminance unevenness was small, it was confirmed that it was because the unevenness was not formed densely, or that the glossiness was higher than 120% when the mirror was 60°, and sufficient anti-glare properties could not be obtained.

<Preferred aspect of the present invention>

In the following, a preferred aspect of the present invention is added.

[Annex 1]

According to an aspect of the present invention,

As a photocurable resin composition containing a photopolymerizable component (A), fine particles (B) and a photopolymerization initiator (C),

The photopolymerizable component (A) contains a photopolymerizable (meth)acrylic resin (a1) having a weight average molecular weight of 10,000 or more,

The fine particles (B) contain organic fine particles and/or inorganic fine particles having an average particle diameter of 1.0 μm or more and 2.8 μm or less,

A photocurable resin composition having a viscosity at 23°C of 1 mPa·s or more and 1000 mPa·s or less is provided.

[Annex 2]

In the photocurable resin composition of Appendix 1, preferably,

As the fine particles (B), silicon fine particles containing alumina fine particles are included.

[Annex 3]

In the photocurable resin composition of Appendix 1 or 2, Preferably,

The fine particles (B) are contained within a range of 0.1 parts by mass or more and 20 parts by mass or less based on 100 parts by mass of solid content.

[Annex 4]

In the photocurable resin composition in any one of appendices 1 to 3, preferably,

The photopolymerizable component (A) contains a (meth)acrylate-based monomer and/or a (meth)acrylate-based resin (a2) other than the photopolymerizable (meth)acrylic resin (a1).

[Annex 5]

According to another aspect of the present invention,

A cured film formed of any one of the photocurable resin compositions described in Appendix 1 to 4 and having irregularities due to the fine particles (B) on its surface is provided.

[Annex 6]

In the cured film of Appendix 5, preferably,

The surface roughness Ra is 0.01 µm or more and 0.17 µm or less.

[Annex 7]

In the cured film of Appendix 5 or 6, preferably,

The average spacing Sm of the irregularities is 30 µm or more and 300 µm or less.

[Annex 8]

In any one of the cured coatings in Appendix 5 to 7, Preferably,

The glossiness of a 60° mirror measured in accordance with JIS K5600-4-7 is 120% or less.

[Annex 9]

According to another aspect of the present invention,

An anti-glare film provided with a transparent substrate and a cured coating of any one of notes 5 to 8 provided on the transparent substrate is provided.

[Annex 10]

In the anti-glare film of Appendix 9, preferably,

The turbidity measured according to JIS K7136 is 40% or less.

[Annex 11]

In the anti-glare film of Appendix 9 or 10, preferably,

In accordance with JIS K7374, the total value of image sharpness measured using optical combs having a slit width of 0.125 mm, 0.25 mm, 0.5 mm, 1.0 mm and 2.0 mm is 350% or more.

[Annex 12]

According to another aspect of the present invention,

An image display device provided with any one of the anti-glare films of Appendix 9 to 11 is provided.

[Annex 13]

According to another aspect of the present invention,

A method for producing a cured film having a curing step of curing the photocurable resin composition of Appendix 1 to 4 by light irradiation is provided.

[Annex 14]

According to another aspect of the present invention,

A coating step of applying any one of the photocurable resin compositions of Appendix 1 to 4 to at least one main surface of the transparent substrate, and

After the coating step, there is provided a method for producing an anti-glare film having a curing step of curing the photocurable resin composition by light irradiation to form a cured film.

1 anti-glare film
10 Cured film (glare layer)
11 convex
20 Transparency substrate

Claims (15)

As a photocurable resin composition containing a photopolymerizable component (A), fine particles (B) and a photopolymerization initiator (C),
The photopolymerizable component (A) contains a photopolymerizable (meth)acrylic resin (a1) having a weight average molecular weight of 10,000 or more,
The fine particles (B) contain polyorgano silsesquioxane fine particles containing aluminum oxide fine particles having an average particle diameter of 1.0 μm or more and 2.8 μm or less,
A photocurable resin composition having a viscosity of 1 mPa·s or more and 1000 mPa·s or less at 23°C.
The method of claim 1,
A photocurable resin composition comprising the fine particles (B) in a range of 0.1 parts by mass or more and 20 parts by mass or less based on 100 parts by mass of solid content.
The method of claim 1,
A sight characterized in that the photopolymerizable component (A) contains a (meth)acrylate-based monomer and/or a (meth)acrylate-based resin (a2) other than the photopolymerizable (meth)acrylic resin (a1) Chemical conversion resin composition.
A cured film formed of the photocurable resin composition according to claim 1, and having irregularities due to the fine particles (B) on its surface.
The method of claim 4,
A cured coating having a surface roughness Ra of 0.01 µm or more and 0.17 µm or less.
The method of claim 4,
The cured film, characterized in that the average spacing Sm of the irregularities is 30 µm or more and 300 µm or less.
The method of claim 5,
The cured film, characterized in that the average spacing Sm of the irregularities is 30 µm or more and 300 µm or less.
The method of claim 4,
A cured coating having a glossiness of 120% or less on a 60° mirror surface measured in accordance with JIS K5600-4-7.
An anti-glare film comprising a transparent substrate and the cured film according to claim 4 provided on the transparent substrate.
The method of claim 9,
An anti-glare film characterized in that the turbidity measured in accordance with JIS K7136 is 40% or less.
The method of claim 9,
An anti-glare film according to JIS K7374, wherein the total value of the image sharpness measured using an optical comb having a slit width of 0.125 mm, 0.25 mm, 0.5 mm, 1.0 mm and 2.0 mm is 350% or more. An image display device comprising the anti-glare film according to claim 9.
A method for producing a cured film, comprising a curing step of curing the photocurable resin composition according to claim 1 by light irradiation.
A coating step of applying the photocurable resin composition according to claim 1 to at least one main surface of a transparent substrate, and
After the coating step, a method for producing an anti-glare film, comprising a curing step of curing the photocurable resin composition by light irradiation to form a cured film. delete

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