WO2014155787A1

WO2014155787A1 - Optical film

Info

Publication number: WO2014155787A1
Application number: PCT/JP2013/076382
Authority: WO
Inventors: 真章中村
Original assignee: 積水化成品工業株式会社
Priority date: 2013-03-29
Filing date: 2013-09-27
Publication date: 2014-10-02
Also published as: JPWO2014155787A1; TW201437670A; JP6069490B2

Abstract

Provided is an optical film which is capable of sufficiently reducing blue light, while maintaining good transmitted image brightness when arranged on the display screen of a display. This optical film is provided with a light-transmitting base film and an anti-glare layer which is formed on at least one surface of the base film and contains resin particles. This optical film contains a dye, and has an average optical absorptance of 5% or more for the wavelength range of 380-500 nm. The total light transmittance of the optical film is higher than the average light transmittance of the optical film for the wavelength range of 380-500 nm. This optical film preferably comprises a light-transmitting base film (1), an anti-glare layer (2) which is formed on one surface of the base film (1) and contains resin particles, and a dye-containing layer (3) which is formed on the other surface of the base film (1) and contains a dye.

Description

Optical film

The present invention relates to an optical film that can be used as an antiglare film, a protective film or the like disposed on a display screen of a display.

Recently, liquid crystal displays (particularly liquid crystal displays using LEDs (light emitting diodes) as light sources) and LED lighting, which are the mainstream of displays, are light in the blue region (380 to 500 nm) of visible light ("blue light"). In particular, it produces a lot of blue light around 450 nm. This blue light is said to have an adverse effect on the human eye. Therefore, a technique for reducing this blue light has attracted attention. As an optical component for cutting blue light, an optical component including a dielectric multilayer film formed by vapor deposition is known.

For example, paragraph [0006] of Patent Document 1 describes an optical component in which a multilayer film having an average reflectance of 2 to 10% in a wavelength range of 400 to 500 nm is disposed on at least one surface of a plastic substrate. Has been.

JP 2012-93689 A

However, since the optical component of Patent Document 1 uses a dielectric multilayer film, basically, all light in the wavelength range of 400 to 500 nm cut by the optical component becomes reflected light. Therefore, in a situation where the reflected light of the optical component is incident on the eye, there is a concern that the light in the wavelength range of 400 to 500 nm cut by the optical component may enter the eye and adversely affect the eye. The situation where the reflected light of the optical component is incident on the eye is, for example, that the light from the display is incident on the back surface of the surface facing the eye of the optical component and at the same time the surface of the optical component facing the eye. A situation in which light (for example, light from LED illumination) enters, is reflected by an optical component, and enters the eye is conceivable.

The present invention has been made in view of the above problems, and an object of the present invention is to provide an optical that can sufficiently reduce blue light while maintaining good transmitted image luminance when placed on a display screen of a display. To provide a film.

In order to solve the above-described problems, the optical film of the present invention includes a light-transmitting base film and a protective film including at least one of resin particles and silica particles formed on at least one surface of the base film. An optical film comprising a glare layer, comprising a pigment, wherein the optical film has an average light absorption of 5% or more at a wavelength of 380 nm to 500 nm, and the total light transmittance of the optical film is equal to the wavelength of the optical film It is characterized by being higher than the average light transmittance of 380 nm to 500 nm.

According to the above configuration, since the average optical absorptance of the optical film at a wavelength of 380 nm to 500 nm is 5% or more, blue light can be sufficiently reduced. Furthermore, according to the said structure, since it contains the pigment | dye, the blue light cut with this optical film is absorbed by the pigment | dye and reduced. Therefore, in a situation where the reflected light of the optical film is incident on the eye, for example, in a situation where the optical film is disposed on the display screen of the display and external light (for example, light from LED illumination) is incident on the front surface of the optical film. Even if it exists, it can fully suppress that blue light injects into eyes. By sufficiently reducing blue light in this way, it is possible to relieve the burden on the eyes due to blue light that is highly irritating to the eyes, and to prevent eye fatigue and eye diseases.

Further, according to the above configuration, since the total light transmittance of the optical film is higher than the average light transmittance of the optical film at a wavelength of 380 nm to 500 nm, it is favorable when disposed on the display screen of the display. The transmission image brightness can be maintained.

Moreover, according to the said structure, since the glare-proof layer containing at least one of a resin particle and a silica particle is formed on the at least one surface of the said base film, sufficient anti-glare performance can be obtained. .

Further, the optical film can be used as a protective film that is disposed on the display screen of the display and protects the display screen.

According to the present invention, it is possible to provide an optical film capable of sufficiently reducing blue light while maintaining good transmitted image brightness when disposed on a display screen of a display.

It is sectional drawing which shows the structure of the optical film which concerns on one Embodiment of this invention. 2 is a graph showing the spectral transmittance of the optical film obtained in Example 1. FIG. 6 is a graph showing the spectral transmittance of the optical film obtained in Example 4. 10 is a graph showing the spectral transmittance of the optical film obtained in Example 5. 7 is a graph showing the spectral transmittance of the optical film obtained in Example 6. 10 is a graph showing the spectral transmittance of the optical film obtained in Example 7. 10 is a graph showing the spectral transmittance of the optical film obtained in Example 8. 6 is a graph showing the spectral transmittance of the optical film obtained in Comparative Example 1. It is a top view which shows the structure of the optical film which concerns on one Embodiment of this invention. It is a top view which shows the structure of the optical film which concerns on other embodiment of this invention. FIG. 11 is a cross-sectional view taken along line A-A ′ of the optical film shown in FIG. 10. 10 is a graph showing the spectral transmittance of the optical film obtained in Example 9. 10 is a graph showing the spectral transmittance of the optical film obtained in Example 10. 10 is a graph showing the spectral transmittance of the optical film obtained in Example 11.

An optical film of the present invention is an optical film comprising a light-transmitting base film and an antiglare layer formed on at least one surface of the base film and including at least one of resin particles and silica particles. The optical film has an average light absorptivity of 5% or more at a wavelength of 380 nm to 500 nm, and the total light transmittance of the optical film is an average light transmittance of the optical film at a wavelength of 380 nm to 500 nm. Higher than.

The average optical absorptance of the optical film at a wavelength of 380 nm to 500 nm is 5% or more. When the average optical absorptance of the optical film at a wavelength of 380 nm to 500 nm is less than 5%, the effect of reducing blue light by the optical film becomes insufficient. The average optical absorptance of the optical film at a wavelength of 380 nm to 500 nm is preferably in the range of 5 to 45%, more preferably in the range of 5 to 40%, and in the range of 10 to 30%. More preferably it is. By setting the average optical absorptance of the optical film at a wavelength of 380 nm to 500 nm below the upper limit of the above range, the total light transmittance of the optical film can be improved, and when the optical film is disposed on the display screen of the display The color reproducibility of the display screen can be improved. By making the average optical absorptance of the optical film at a wavelength of 380 nm to 500 nm 10% or more, the blue light reduction effect by the optical film can be further enhanced.

The b ^* value of the optical film is preferably within a range of 5 to 35, more preferably within a range of 5 to 30, and further preferably within a range of 5 to 20. It is most preferable to be within the range. When the b ^* value of the optical film is less than 5, there is a possibility that the blue light reduction effect by the optical film is insufficient. If the b ^* value of the optical film exceeds 30, the yellow color of the optical film becomes too strong and the appearance deteriorates, or the color reproduction of the display screen when the optical film is disposed on the display screen of the display May be worse.

The total light transmittance of the optical film is higher than the average light transmittance at a wavelength of 380 nm to 500 nm. If the total light transmittance of the optical film is equal to or less than the average light transmittance at a wavelength of 380 nm to 500 nm, the transmitted image brightness is deteriorated when the optical film is disposed on the display screen of the display. The difference between the total light transmittance of the optical film and the average light transmittance at a wavelength of 380 nm to 500 nm ((total light transmittance) − (average light transmittance at a wavelength of 380 nm to 500 nm)) is 2% or more. Preferably, it is 4% or more. Thereby, the transmission image brightness | luminance when the said optical film is arrange | positioned on the display screen of a display can further be improved. The difference between the total light transmittance of the optical film and the average light transmittance at a wavelength of 380 nm to 500 nm ((total light transmittance) − (average light transmittance at a wavelength of 380 nm to 500 nm)) is 25% or less. Preferably, it is 15% or less. Thereby, the color reproducibility of the display screen when the optical film is disposed on the display screen of the display can be improved.

The total light transmittance of the optical film is preferably 80% or more, more preferably 85% or more, and further preferably 88% or more. If the total light transmittance of the optical film is less than 80%, the transmitted image luminance may be deteriorated when the optical film is disposed on the display screen of the display.

The haze of the optical film is preferably in the range of 1.5 to 40%, more preferably in the range of 2 to 30%. When the haze of the optical film is less than 1.5%, the antiglare performance of the optical film may be deteriorated. If the haze of the optical film exceeds 40%, the transmitted image clarity of the optical film may be deteriorated. For example, the visibility of the display screen when the optical film is disposed on the display screen of the display is poor. There is a risk.

[Base film]
Although it does not specifically limit as a material which comprises the said base film, A general material can be used, For example, a cellulose acylate, the said acrylic resin ((meth) acrylate type polymer), polyester, polycarbonate, polyamide etc. Examples thereof include materials mainly composed of the above resins and inorganic materials such as glass. In the present specification, “(meth) acrylate” means acrylate and / or methacrylate.

Examples of the cellulose acylate include cellulose triacetate, cellulose diacetate, and cellulose acetate butyrate. Examples of the acrylic resin include methyl poly (meth) acrylate, poly (meth) ethyl acrylate, methyl (meth) acrylate-butyl (meth) acrylate, and the like. In this specification, “(meth) acryl” means acryl and / or methacryl. Examples of the polyester include polyethylene terephthalate (hereinafter abbreviated as “PET”), polyethylene naphthalate, and the like.

The thickness of the base film is preferably in the range of 20 to 300 μm, and more preferably in the range of 20 to 200 μm.

[Anti-glare layer]
The thickness of the antiglare layer is preferably 3 to 100 μm, more preferably 5 to 50 μm, and even more preferably 5 to 20 μm. If the thickness of the antiglare layer is less than 3 μm, the surface hardness of the optical film may be insufficient. If the thickness of the antiglare layer exceeds 100 μm, the amount of raw material required to form the antiglare layer increases, which is uneconomical.

The antiglare layer is formed to constitute the surface of the optical film. The antiglare layer may contain at least one of resin particles and silica particles, but preferably contains at least one of resin particles and silica particles and a binder resin. Thereby, the light transmittance of the said glare-proof layer can be made high, and the optical film which has sufficient light transmittance is realizable.

[Resin particles]
Examples of the resin particles include resin particles made of at least one of a (meth) acrylic monomer and a styrene monomer, silicone resin particles, polycarbonate particles, polyethylene particles, polyvinyl chloride particles, and melamine resins. Particles and the like. The resin particles are preferably resin particles made of at least one of a (meth) acrylic monomer and a styrene monomer. In this case, since the light transmittance of the resin particles itself is improved, an optical film having a good total light transmittance can be realized. When the resin particles are made of at least one of a (meth) acrylic monomer and a styrene monomer, the refractive index of the resin particles is generally in the range of 1.41 to 1.60. Specifically, for example, the refractive index of a polymer obtained by polymerizing a (meth) acrylic monomer having a fluorine group-containing alkyl (meth) acrylate as a main component is about 1.41, and (meth) The refractive index of a homopolymer of a (meth) acrylic monomer having an alkyl acrylate as a main component is about 1.495, and a homopolymer of a styrene monomer having a main component of styrene (polystyrene). The refractive index is about 1.595, and the refractive index of a copolymer of a (meth) acrylic monomer mainly composed of alkyl (meth) acrylate and a styrene monomer mainly composed of styrene is It is about 1.495 to 1.595. As a result, the difference in refractive index between the resin particles and the components other than the resin particles (particularly the binder resin) in the antiglare layer tends to be an appropriate difference, and thus the light scattering inside the antiglare layer tends to be an appropriate level. As a result, an optical film having good both haze and total light transmittance is easily realized.

The polymer of at least one of the (meth) acrylic monomer and the styrene monomer contains a structural unit derived from at least one of the (meth) acrylic monomer and the styrene monomer.

The (meth) acrylic monomer is not particularly limited as long as it is a compound having at least one acryloyloxy group or methacryloyloxy group, and is monofunctional (meth) having one ethylenically unsaturated group. It may be an acrylic monomer or a polyfunctional (meth) acrylic monomer having two or more ethylenically unsaturated groups.

The monofunctional (meth) acrylic monomer is not particularly limited, and examples thereof include (meth) acrylic acid, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl methacrylate, (Meth) acrylic such as n-butyl (meth) acrylate, isobutyl (meth) acrylate, n-octyl methacrylate, 2-ethylhexyl (meth) acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate Acid alkyl; fluorine-containing (meth) acrylic acid ester such as 2,2,2-trifluoroethyl methacrylate, 2,2,3,3-tetrafluoropropyl methacrylate, perfluorooctylethyl acrylate; tetrahydrofurfuryl acrylate, etc. Heterocyclic group-containing (meth) acrylic acid ester; (meth) acrylic acid Glycidyl group-containing (meth) acrylic acid esters such as ricidyl; (meth) acrylic acid hydroxyalkyl such as 2-hydroxyethyl acrylate and 2-hydroxypropyl acrylate; amino such as dimethylaminoethyl methacrylate and diethylaminoethyl methacrylate Examples thereof include group-containing (meth) acrylic acid esters. These monofunctional (meth) acrylic monomers may be used alone or in a combination of two or more.

The polyfunctional (meth) acrylic monomer is not particularly limited as long as it is a compound having two or more acryloyloxy groups or methacryloyloxy groups. For example, trimethylolpropane triacrylate, dimethacrylate Acid ethylene glycol, dimethacrylic acid diethylene glycol, dimethacrylic acid triethylene glycol, dimethacrylic acid decaethylene glycol, dimethacrylic acid pentadecaethylene glycol, dimethacrylic acid pentacontactor ethylene glycol, dimethacrylic acid 1,3-butylene, methacrylic acid Examples include allyl acid, trimethylolpropane trimethacrylate, pentaerythritol tetramethacrylate, and diethylene glycol dimethacrylate. These polyfunctional (meth) acrylic monomers may be used alone or in a combination of two or more.

The styrene monomer is not particularly limited as long as it is a styrene (styrene or styrene derivative), and may be a monofunctional styrene monomer having one ethylenically unsaturated group, It may be a polyfunctional styrenic monomer having two or more ethylenically unsaturated groups.

The monofunctional styrene monomer is not particularly limited, and examples thereof include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, and the like. These monofunctional styrenic monomers may be used alone or in combination of two or more.

The polyfunctional styrene-based monomer is not particularly limited, and examples thereof include aromatic divinyl compounds such as divinylbenzene, divinylnaphthalene, and derivatives thereof. These polyfunctional styrene monomers may be used alone or in a combination of two or more.

The structural unit derived from the monofunctional (meth) acrylic monomer and / or the monofunctional styrene monomer is preferably in the range of 50 to 95% by weight with respect to 100% by weight of the polymer. . If the amount of the structural unit derived from the monofunctional (meth) acrylic monomer and / or monofunctional styrene monomer is less than 50% by weight, further improvement in solvent resistance cannot be expected, Cost will increase. When the amount of the structural unit derived from the monofunctional (meth) acrylic monomer and / or the monofunctional styrene monomer is more than the above range, the degree of cross-linking of the polymer is low, and thus resin particles are included. When applying a paint, the resin particles may swell and the viscosity of the paint may increase, and the workability of the application may be reduced. The amount of the structural unit derived from the monomer with respect to 100% by weight of the polymer corresponds to the amount of the monomer with respect to 100% by weight of the total amount of all monomers.

The polymer may be a homopolymer of a (meth) acrylic monomer or a homopolymer of a styrene monomer, and a (meth) acrylic monomer and styrene. It may be a copolymer with a monomer based on at least one of a (meth) acrylic monomer and a styrene monomer and another vinyl monomer (at least one ethylenically unsaturated group). And a copolymer thereof.

Examples of the other vinyl monomers include saturated fatty acid vinyl such as vinyl acetate, vinyl propionate and vinyl versatate; α, β-unsaturated nitrile such as acrylonitrile and methacrylonitrile; (meth) acrylic acid, Α, β-unsaturated carboxylic acids such as crotonic acid, citraconic acid, itaconic acid, maleic acid, fumaric acid, monoalkyl esters of α, β-unsaturated dicarboxylic acids (eg monobutyl maleate); Α, β-unsaturated carboxylates such as ammonium salts or alkali metal salts of saturated carboxylic acids; α, β-unsaturated carboxylic anhydrides such as maleic anhydride; (meth) acrylamide, diacetone acrylamide, N-methylol (Meth) acrylamide, N-methylol methacrylamide, methylolated diacetone acrylamide, Α, β-unsaturated amides such as N-alkoxymethyl acrylamide (eg, N-isobutoxymethyl acrylamide) having 1 to 8 carbon atoms in the alkoxy group; polyfunctional (such as diallyl phthalate and triallyl cyanurate) Examples thereof include polyfunctional vinyl monomers other than (meth) acrylic monomers and polyfunctional styrene monomers.

The amount of the structural unit derived from the polyfunctional vinyl monomer is 5 with respect to 100 parts by weight of the structural unit derived from the monofunctional (meth) acrylic monomer and / or the monofunctional styrene monomer. It is preferably in the range of ˜100 parts by weight, and preferably in the range of 5˜50% by weight with respect to 100% by weight of the polymer. When the amount of the structural unit derived from the polyfunctional vinyl monomer is less than the above range, the degree of crosslinking of the polymer is low. As a result, when a paint containing resin particles is applied, the resin particles may swell and increase the viscosity of the paint, which may reduce the workability of the coating.

The volume average particle diameter of the resin particles is preferably in the range of 0.3 to 10 μm, and more preferably in the range of 0.5 to 5 μm. When the volume average particle diameter of the resin particles is less than 0.3 μm, the light transmittance of the antiglare layer increases and the antiglare performance of the optical film decreases. When the volume average particle diameter of the resin particles exceeds 10 μm, the haze of the optical film is increased, which may cause glare when the optical film is disposed on a light output surface such as a display screen of a display. .

The coefficient of variation of the particle diameter of the resin particles (hereinafter, the coefficient of variation of the particle diameter is referred to as “CV value”) is preferably 30% or less, more preferably 20% or less, and 15% or less. More preferably it is. When the CV value of the resin particles exceeds 20%, particularly more than 30%, the unevenness of the surface of the antiglare layer becomes large, and bright spots appear when an optical film is disposed on the light output surface such as a display screen of a display. Many are likely to occur. Furthermore, if the CV value of the resin particles exceeds 20%, particularly more than 30%, the particle size distribution of the resin particles becomes wide. Therefore, when the antiglare layer is formed, Defects are likely to occur.

The content of the resin particles in the antiglare layer is preferably 1 to 10 parts by weight and more preferably 3 to 8 parts by weight with respect to 100 parts by weight of the binder resin. There exists a possibility that sufficient anti-glare property cannot be provided to an anti-glare layer as the content rate of the resin particle in the said anti-glare layer is less than 3 weight part. When the content of the resin particles in the antiglare layer exceeds 8 parts by weight, the haze of the optical film is increased, and glare occurs when the optical film is disposed on the light output surface such as a display screen of a display. There is a risk of becoming.

[Silica particles]
The volume average particle diameter of the silica particles is preferably in the range of 0.3 to 10 μm, and more preferably in the range of 0.5 to 5 μm. When the volume average particle diameter of the silica particles is less than 0.3 μm, the light transmittance of the antiglare layer increases and the antiglare performance of the optical film decreases. When the volume average particle diameter of the silica particles exceeds 10 μm, the haze of the optical film increases, which may cause glare when the optical film is disposed on a light exit surface such as a display screen of a display. is there.

The CV value of the silica particles (when the silica particles are a mixture of a plurality of types of silica particles having different volume average particle sizes, the CV value of the mixture) is preferably 30% or less, and 20% or less. It is more preferable that it is 15% or less. When the CV value of the silica particles exceeds 30%, unevenness on the surface of the antiglare layer becomes large, and many bright spots are likely to occur when an optical film is disposed on a light exit surface such as a display screen of a display. . Further, when the CV value of the silica particles exceeds 30%, the particle size distribution of the resin particles becomes wide, so that when the antiglare layer is formed, defects in the antiglare layer are likely to occur due to the coarse particles. .

The silica particles are a mixture of a plurality of types of silica particles having different volume average particle diameters, and each CV value of the plurality of types of silica particles is preferably 20% or less, and the silica particles have a volume average A mixture comprising first silica particles having a particle diameter of 5 to 10 μm and second silica particles having a volume average particle diameter of 1 to 3 μm, wherein the first silica particles and the second silica particles It is more preferable that the coefficient of variation of the particle diameter of each is 20% or less. When the CV value of the silica particles exceeds 20%, unevenness on the surface of the antiglare layer increases, and many bright spots are likely to occur when an optical film is disposed on a light exit surface such as a display screen of a display. . Further, when the CV value of the silica particles exceeds 20%, the particle size distribution of the resin particles becomes wide, so that when the antiglare layer is formed, defects in the antiglare layer are likely to occur due to the coarse particles. . Further, by using a combination of a plurality of types of silica particles, in particular, a combination of a first silica particle having a volume average particle diameter of 5 to 10 μm and a second silica particle having a volume average particle diameter of 1 to 3 μm, an optical film The anti-glare property and the total light transmittance can be balanced. When the volume average particle diameter of the silica particles is increased, the haze is increased and the antiglare property is improved, while the total light transmittance is decreased. When the volume average particle diameter of the silica particles is reduced, the total light transmittance is increased while the haze is decreased. Therefore, silica particles having a larger volume average particle diameter, particularly silica particles having a smaller volume average particle diameter, particularly 1 to 3 volume average particle diameter than the first silica particles having a volume average particle diameter of 5 to 10 μm. By mixing the second silica particles of 3 μm, it is possible to balance the antiglare property and the total light transmittance of the optical film, and to provide an optical film with good antiglare property and total light transmittance. realizable.

The content of the resin particles and / or silica particles in the antiglare layer is preferably 1 to 12 parts by weight, more preferably 1 to 10 parts by weight with respect to 100 parts by weight of the binder resin. More preferably, it is ˜8 parts by weight. If the content of the resin particles and / or silica particles in the antiglare layer is less than 1 part by weight, sufficient antiglare properties may not be imparted to the antiglare layer. When the content of the resin particles and / or silica particles in the antiglare layer exceeds 12 parts by weight, the haze of the optical film increases, and when the optical film is disposed on the light output surface such as the display screen of the display May cause glare.

[Characteristics of antiglare layer]
The antiglare layer is a layer (so-called hard coat layer) having a pencil hardness of 2H or more as measured by a pencil hardness test specified in JIS K 5600-5-4: 1999 (load applied to the pencil is 4.9 N). ) Is preferable. Thereby, an optical film excellent in scratch resistance can be realized. Therefore, when the optical film is disposed on the surface of the display screen or the like of the display so that the surface on which the antiglare layer is formed faces the outside (the side opposite to the surface), The optical film functions as a protective film that can sufficiently protect the surface of the display screen and the like from scratches.

[Binder resin]
Examples of the binder resin include a thermoplastic resin, a thermosetting resin, a mixture of an ionizing radiation curable resin and an ionizing radiation polymerization initiator.

Examples of the thermoplastic resin include cellulose derivatives such as acetylcellulose, nitrocellulose, acetylbutylcellulose, ethylcellulose, and methylcellulose; vinyl acetate homopolymers or copolymers, vinyl chloride homopolymers or copolymers, and chlorides. Vinylidene homopolymers or copolymers; acetal resins such as polyvinyl formal and polyvinyl butyral; acrylic resins (polyacrylate esters) and their copolymer resins, methacrylic resins (polymethacrylate esters) and their copolymer resins, etc. (Meth) acrylic resin; polystyrene resin; polyamide resin; linear polyester resin; polycarbonate resin.

Examples of the thermosetting resin include a thermosetting acrylic resin, a thermosetting urethane resin composed of an acrylic polyol and an isocyanate prepolymer, a phenol resin, a urea melamine resin, an epoxy resin, an unsaturated polyester resin, and a silicone resin. Etc.

The ionizing radiation curable resin may be any resin that can be cured by irradiating with ionizing radiation (ultraviolet rays, electron beams, etc.), such as an ionizing radiation polymerizable monomer or an ionizing radiation polymerizable prepolymer (ionizing radiation). What mixed 1 type (s) or 2 types or more, such as a polymerizable oligomer), can be used. As the ionizing radiation polymerizable monomer or ionizing radiation polymerizable prepolymer, an ionizing radiation polymerizable polyfunctional monomer having two or more ionizing radiation polymerizable functional groups in one molecule, or in one molecule An ionizing radiation polymerizable polyfunctional prepolymer having two or more ionizing radiation polymerizable functional groups is preferred.

The ionizing radiation polymerizable functional group possessed by the ionizing radiation polymerizable polyfunctional prepolymer or the polyfunctional monomer is a photopolymerizable functional group, an electron beam polymerizable functional group, or a radiation polymerizable functional group. Are preferred, and photopolymerizable functional groups are particularly preferred. Specific examples of the photopolymerizable functional group include unsaturated polymerizable functional groups such as a (meth) acryloyl group, a vinyl group, a styryl group, and an allyl group. ) An acryloyl group is preferred. In the present specification, “(meth) acryloyl” represents acryloyl or methacryloyl.

The ionizing radiation polymerizable polyfunctional prepolymer is preferably a polyfunctional prepolymer having two or more photopolymerizable functional groups (hereinafter referred to as “photopolymerizable polyfunctional prepolymer”). As the photopolymerizable polyfunctional prepolymer, a (meth) acrylic prepolymer having two or more (meth) acryloyl groups in one molecule is particularly preferably used. Such a (meth) acrylic prepolymer becomes a three-dimensional network structure by crosslinking and curing. Examples of the (meth) acrylic prepolymer include urethane (meth) acrylate, polyester (meth) acrylate, epoxy (meth) acrylate, and melamine (meth) acrylate.

As the ionizing radiation polymerizable monomer, the above-mentioned polyfunctional vinyl monomers can be used, but a polyfunctional monomer having two or more photopolymerizable functional groups (hereinafter referred to as “photopolymerizable polyfunctional”). (Referred to as "monomer"). Specific examples of the photopolymerizable polyfunctional monomer include alkylene glycol di (meth) acrylates such as neopentyl glycol acrylate, 1,6-hexanediol (meth) acrylate, and propylene glycol di (meth) acrylate; Polyoxyalkylene glycol di (meth) acrylates such as ethylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate; pentaerythritol di (meta) ) Di (meth) acrylates of trihydric or higher polyhydric alcohols such as acrylates; 2,2-bis [4- (acryloxy-diethoxy) phenyl] propane, 2,2-bis [4- (acryloxy-polypropylene) Di (meth) acrylates of polyhydric alcohol ethylene oxide adducts or polyhydric alcohol propylene oxide adducts such as xyl) phenyl] propane; polyfunctional monomers having 3 or more (meth) acryloyl groups in one molecule be able to.

The photopolymerizable polyfunctional monomer is preferably an ester of a polyhydric alcohol and (meth) acrylic acid as in these specific examples, and has 3 or more (meth) acryloyl groups in one molecule. The polyfunctional monomer having is more preferable. Specific examples of the polyfunctional monomer having three or more (meth) acryloyl groups in one molecule include trimethylolpropane tri (meth) acrylate, trimethylolethane tri (meth) acrylate, 1,2,4- Cyclohexanetetra (meth) acrylate, pentaglycerol triacrylate, pentaerythritol tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol triacrylate, dipentaerythritol pentaacrylate, dipentaerythritol tetra (meth) acrylate, di Examples include pentaerythritol hexa (meth) acrylate, tripentaerythritol triacrylate, and tripentaerythritol hexaacrylate. Two or more kinds of the photopolymerizable polyfunctional monomers may be used in combination.

When the photopolymerizable polyfunctional monomer or photopolymerizable polyfunctional prepolymer is used as the ionizing radiation polymerizable monomer or ionizing radiation polymerizable prepolymer, a photopolymerization initiator is used as the ionizing radiation polymerization initiator. It is preferable to use as. As the photopolymerization initiator, a photoradical polymerization initiator or a photocationic polymerization initiator is preferable, and a photoradical polymerization initiator is particularly preferable.

Polymerization of the photopolymerizable polyfunctional monomer or photopolymerizable polyfunctional prepolymer can be performed by irradiation with ionizing radiation in the presence of a photo radical initiator. Accordingly, a paint containing the photopolymerizable polyfunctional monomer or photopolymerizable polyfunctional prepolymer, a photo radical initiator, and at least one of resin particles and silica particles is prepared, and the paint is applied to the base film. After the coating, the antiglare layer can be formed on at least one surface of the substrate film by curing the paint by a polymerization reaction by ionizing radiation.

Examples of the photo radical polymerization initiator include acetophenones, benzoins, benzophenones, phosphine oxides, ketals, α-hydroxyalkylphenones, α-aminoalkylphenones, anthraquinones, thioxanthones, azo compounds, peroxides (Described in JP 2001-139663 A), 2,3-dialkyldione compounds, disulfide compounds, fluoroamine compounds, aromatic sulfoniums, onium salts, borate salts, active halogen compounds, α-acyloxy Muester and the like.

Examples of the acetophenones include acetophenone, 2,2-diethoxyacetophenone, p-dimethylacetophenone, 1-hydroxydimethylphenyl ketone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-4-methylthio-2-morpholinopropio. Examples include phenone and 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone. Examples of the benzoins include benzoin, benzoin benzoate, benzoin benzene sulfonate, benzoin toluene sulfonate, benzoin methyl ether, benzoin ethyl ether, and benzoin isopropyl ether. Examples of the benzophenones include benzophenone, 2,4-dichlorobenzophenone, 4,4-dichlorobenzophenone, p-chlorobenzophenone, and the like. Examples of the phosphine oxides include 2,4,6-trimethylbenzoyldiphenylphosphine oxide. Examples of the ketals include benzylmethyl ketals such as 2,2-dimethoxy-1,2-diphenylethane-1-one. Examples of the α-hydroxyalkylphenones include 1-hydroxycyclohexyl phenyl ketone. Examples of the α-aminoalkylphenones include 2-methyl-1- [4- (methylthio) phenyl] -2- (4-morpholinyl) -1-propanone.

Commercially available photocleavable photoradical polymerization initiators include trade names “Irgacure (registered trademark) 651” (2,2-dimethoxy-1,2-diphenylethane-1-one) manufactured by BASF Japan Ltd., BASF Trade name “Irgacure (registered trademark) 184” (1-hydroxycyclohexyl phenyl ketone) manufactured by Japan Co., Ltd., trade name “Irgacure (registered trademark) 907” (2-methyl-1- [4- (Methylthio) phenyl] -2- (4-morpholinyl) -1-propanone), trade name “Irgacure (registered trademark) 2959” (1- {4- (2-hydroxyethoxy) -phenyl}) manufactured by BASF Japan Ltd. -Hydroxy-2-methyl-1-propan-1-one) and the like are preferable examples.

The photopolymerization initiator is preferably used within a range of 0.1 to 15 parts by weight with respect to 100 parts by weight of the photopolymerizable polyfunctional monomer or photopolymerizable polyfunctional prepolymer. More preferably, it is used within the range of 10 parts by weight.

In the polymerization of the photopolymerizable polyfunctional monomer or photopolymerizable polyfunctional prepolymer, a photosensitizer may be used in addition to the photopolymerization initiator. Specific examples of the photosensitizer include n-butylamine, triethylamine, tri-n-butylphosphine, Michler's ketone, thioxanthones and the like.

In the paint, a solvent (diluent) for diluting the binder resin may be used as necessary. Examples of the solvent include aromatic hydrocarbon solvents such as toluene and xylene; ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone; ester solvents such as ethyl acetate and butyl acetate; ether solvents such as dioxane and ethylene glycol diethyl ether Water, alcohol solvents and the like. These solvents may be used alone or in combination of two or more.

When the antiglare layer is formed using a paint containing an ionizing radiation curable resin, by applying the paint and then irradiating the paint with ionizing radiation (ultraviolet rays, electron beams, etc.) to cure the paint The antiglare layer can be formed. As a method of irradiating with ionizing radiation, a method of irradiating ultraviolet rays in a wavelength region of 100 to 400 nm, preferably 200 to 400 nm, emitted from an ultrahigh pressure mercury lamp, a high pressure mercury lamp, a low pressure mercury lamp, a carbon arc, a metal halide lamp or the like; For example, a method of irradiating an electron beam having a wavelength region of less than 100 nm emitted from a mold or curtain type electron beam accelerator can be used.

As a method for applying the paint on the base film, a reverse roll coating method, a gravure coating method, a die coating method, a comma coating method, a spray coating method, or the like can be used.

[Dye]
The dye preferably contains a first dye having a maximum absorption wavelength in an ultraviolet-visible absorption spectrum (ultraviolet-visible absorption spectrum having a wavelength of 300 to 800 nm) in the range of 380 to 500 nm. Thereby, blue light can be reduced more effectively.

The ultraviolet-visible absorption spectrum of the dye can be measured using the following measurement method. 0.001 part by weight of the dye is added to 100 parts by weight of the solvent in which the dye is soluble, and the dye is dissolved in the solvent to obtain a dye solution. The obtained dye solution is measured for an ultraviolet-visible absorption spectrum having a wavelength of 300 to 800 nm using a spectrophotometer (trade name “Hitachi spectrophotometer U-3900”, Hitachi High-Technologies Corporation). Before measuring the dye solution, a baseline is established by measuring an ultraviolet-visible absorption spectrum having a wavelength of 300 to 800 nm with the spectrophotometer for the solvent used for dissolving the dye.

The first dye is not particularly limited as long as it is a dye having a maximum absorption wavelength in the ultraviolet-visible absorption spectrum in the range of 380 to 500 nm, and is a dye that can be dissolved in an organic solvent (oil-soluble dye) or pigment. , Dyes and the like can be used. Among these, a dye that can be dissolved in an organic solvent is preferable as the first dye. Preferred organic solvents include aromatic hydrocarbon solvents such as toluene and xylene; ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone; ester solvents such as ethyl acetate and butyl acetate; ether solvents such as dioxane and ethylene glycol diethyl ether A solvent etc. are mentioned. More preferable organic solvents include aromatic hydrocarbon solvents such as toluene, methyl isobutyl ketone, and methyl ethyl ketone. Examples of the dye that can be dissolved in an organic solvent include “YELLOW 93” (CI Solvent Yellow 93), “OIL YELLOW 186”, C.I. I. Solvent Yellow 16, C.I. I. Solvent Yellow 33, C.I. I. Solvent Yellow 79, C.I. I. Solvent Yellow 82 (for example, “VALIFAST (registered trademark) YELLOW 4120” manufactured by Orient Chemical Co., Ltd.), C.I. I. Solvent Orange 80, C.I. I. Solvent Orange 45 (for example, “VALIFAST (registered trademark) YELLOW 3108” manufactured by Orient Chemical Co., Ltd.), C.I. I. Solvent Orange 62, C.I. I. Solvent Orange 54 (for example, “VALIFAST (registered trademark) ORANGE 3210” manufactured by Orient Chemical Co., Ltd.), C.I. I. Solvent Yellow 151 (for example, “VALIFAST (registered trademark) YELLOW 3170” manufactured by Orient Chemical Co., Ltd.), C.I. I. Acid Yellow 42 (for example, “VALIFAST (registered trademark) YELLOW 1101” manufactured by Orient Chemical Co., Ltd.), “DAA51” (trade name) (manufactured by Yamada Chemical Co., Ltd.), C.I. I. Pigment yellow 74 (for example, “Fast Yellow 7416” manufactured by Sanyo Dyeing Co., Ltd.), “NAZ24” (trade name) (manufactured by Yamada Chemical Co., Ltd.), and the like. Examples of the pigment include azo pigments such as benzidine yellow 14 and polycyclic pigments as organic pigments. These dyes may be used alone or in combination of two or more.

The dye preferably contains a blue second dye in addition to the first dye. That is, it is preferable to use a mixture of the first dye and the blue second dye as the dye. When the first pigment is used alone as the pigment, the optical film is colored yellow or a color close to it (for example, orange), and the optical film has a yellowish appearance. On the other hand, when a blue 2nd pigment | dye is mixed with a said 1st pigment | dye, the yellowishness of the said optical film can be suppressed and the color tone of the said optical film can be made into a color kind to eyes. Here, the blue dye means a dye having an absorption maximum peak (maximum absorption wavelength) in the range of 570 to 620 nm.

Examples of the blue second dye include “NEO SUPER BLUE C-558” manufactured by Chuo Synthetic Chemical Co., Ltd., and tetraazaporphyrin-based compounds (for example, “TAP-2” “TAP” manufactured by Yamada Chemical Co., Ltd.). -18 "" TAP-45 "), C.I. I. Pigment blue 15: 3, C.I. I. Pigment Blue 15, Bituminous Blue, Cobalt Blue, Alkaline Blue Lake, Victoria Blue Lake, Phthalocyanine Blue, Metal-free Phthalocyanine Blue, Partially Chlorinated Phthalocyanine Blue, Fast Sky Blue, Indanthrene Blue BC, C.I. I. Solvent Blue 35, C.I. I. Solvent Blue 70 etc. are mentioned. These dyes may be used alone or in combination of two or more.

Further, in order to adjust the color of the optical film, other pigments other than the first pigment and the second pigment can be added to the antiglare layer. Examples of the other dye include C.I. I. Solvent Red 132, C.I. I. Solvent Black 27, “OIL GREEN 502” (manufactured by Orient Chemical Industry Co., Ltd.), “OIL GREEN BG” (manufactured by Orient Chemical Industry Co., Ltd.), “VALIFAST (registered trademark) RED 3306” (manufactured by Orient Chemical Industry Co., Ltd.), etc. Is mentioned. These other pigments may be used alone or in combination of two or more.

The dye may be contained in a dye-containing layer formed on at least one surface of the base film, or may be contained in the base film. The dye-containing layer may be formed as a layer different from the antiglare layer, or may be formed as the antiglare layer. That is, the pigment may be contained in a pigment-containing layer formed as a layer separate from the antiglare layer, or may be contained in the antiglare layer. However, if pigments are contained in the antiglare layer that is exposed at the time of use, the scratch resistance of the optical film at the time of use may be reduced. It is preferred that the antiglare layer at the position to be a surface does not contain a pigment. Moreover, since the anti-glare property of an optical film may fall when the pigment | dye is contained in the glare-proof layer, it is preferable that a pigment | dye is not contained in the glare-proof layer.

(UV-visible light absorber)
The optical film has an ultraviolet-visible absorption spectrum (ultraviolet-visible absorption spectrum having a wavelength of 300 to 800 nm) having a maximum absorption wavelength in the range of 320 nm or more and less than 380 nm, and also has an absorption in the visible region of a wavelength of 380 nm or more. It may further contain a light absorber. Thereby, blue light can be further reduced while maintaining the total light transmittance of the optical film at a good level.

[Correction 09.04.2014 based on Rule 91]
Examples of the UV-visible light absorber include 2,4,6-tris (2-hydroxy-4-hexyloxy-3-methylphenyl) -1,3,5-triazine, hydroxyphenylbenzotriazole, 2-hydroxy- Examples include 4-methoxybenzophenone, 2,4-benzoylresorcin, 2,2-dihydroxy-4-methoxybenzophenone, and the like. These ultraviolet and visible light absorbers may be used alone or in combination of two or more.

The ultraviolet-visible light absorber may be contained in a dye-containing layer formed on at least one surface of the base film, or may be contained in the base film. That is, the ultraviolet-visible light absorber may be contained in a dye-containing layer formed as a layer separate from the antiglare layer, or may be contained in the antiglare layer.

[Structure of optical film]
As shown in FIG. 1, the optical film of the present invention preferably has a light-transmitting base film 1 and at least one of resin particles and silica particles formed on one surface of the base film 1. The anti-glare layer 2 containing a pigment | dye and the pigment | dye containing layer 3 containing the pigment | dye formed on the other surface of the said base film 1 are included.

In the optical film having the configuration shown in FIG. 1, the dye is included in the dye-containing layer 3 formed on one surface of the base film 1. The dye-containing layer 3 is formed as a layer different from the antiglare layer 2. That is, the pigment is contained in the pigment-containing layer 3 formed as a layer separate from the antiglare layer 2.

In the optical film having the configuration shown in FIG. 1, the yellowish color is basically colored by the pigment, but according to the above configuration, the yellowness is slightly suppressed when the optical film is viewed from the antiglare layer 2 side. That is, the light from the pigment is basically yellowish light, but the color of the light is diffused when passing through the anti-glare layer 2 so that the saturation is lowered (becomes white). To reach. Therefore, the apparent yellowness of the optical film is suppressed.

When the optical film of the present invention is affixed to a display having a display screen and a frame surrounding the display screen, generally, the external shape thereof is substantially the same as the external shape of the entire display. To be shaped. At this time, if the optical film has the configuration shown in FIG. 1, the dye-containing layer 3 is formed on the entire surface of the optical film by printing or the like as shown in the plan view of FIG. In other words, the color of the display frame is affected by the coloring of the dye-containing layer 3 because the dye-containing layer 3 is disposed not only at the position overlapping the display screen of the display but also at the position overlapping the display frame. Here, when the display is a display having a dark frame such as black, coloring of the display frame does not become obvious, but the display has a light color frame such as white ( For example, in the case of an Apple tablet personal computer “iPad (registered trademark)” or an Apple smartphone “iPhone (registered trademark)”, the frame of the display is colored yellowish May appear and the display may not look good.

Therefore, when the optical film of the present invention is affixed to a display having a display screen and a frame surrounding the display screen, the optical film of the present invention is at least one of the base film. A dye-containing layer containing the dye and a binder resin is formed on the surface, and the dye-containing layer is formed only on a portion corresponding to the display screen of the display on at least one surface of the base film. May be. Thus, by disposing a dye-containing layer that cuts blue light only on a portion corresponding to a display screen emitting blue light on at least one surface of the base film, a frame of a display using an optical film is provided. Can be prevented and the appearance of the display can be improved.

One embodiment of the optical film having such a configuration is shown in FIGS. FIG. 10 is a plan view showing the optical film of this embodiment, and FIG. 11 is a cross-sectional view of the optical film shown in FIG. 10 taken along the line A-A ′. As shown in FIG. 11, the optical film of this embodiment includes a light-transmissive base film 1 and at least one of resin particles and silica particles formed on one surface of the base film 1. The anti-glare layer 2, the dye-containing layer 3 containing the dye formed on the other surface of the base film 1, and the adhesive formed on the back surface of the base film 1 side of the dye-containing layer 3 And an agent layer 4. When the optical film of this embodiment is attached to a display, the surface on the antiglare layer 2 side becomes the front surface (exposed surface), and the surface on the adhesive layer 4 side becomes the back surface (surface in contact with the display).

And as shown in FIG. 10, the said pigment | dye containing layer 3 is one side of the said base film 1 among the whole area | regions on the one side of the said base film 1 (it respond | corresponds to the whole surface of a display). It is formed only on the portion corresponding to the display screen of the display on the surface, and is not formed on the portion corresponding to the frame of the display on one surface of the base film 1.

In the optical film of this embodiment, the pigment is contained in the pigment-containing layer 3 formed on one surface of the base film 1. The dye-containing layer 3 is formed as a layer different from the antiglare layer 2. That is, the pigment is contained in the pigment-containing layer 3 formed as a layer separate from the antiglare layer 2. The pressure-sensitive adhesive layer will be described later.

In addition, as a method of forming the dye-containing layer only on a portion corresponding to the display screen of the display on at least one surface of the base film, a method of forming the dye-containing layer by printing such as an inkjet method or gravure printing Is mentioned.

(Dye-containing layer)
The dye-containing layer formed as a layer different from the antiglare layer or as the antiglare layer will be described below.

The dye-containing layer may contain a dye, but preferably contains a dye and a binder resin. Thereby, the light transmittance of the said pigment | dye containing layer can be made high, and the optical film which has sufficient light transmittance is realizable.

The amount of the first dye added to the dye-containing layer is preferably in the range of 0.01 to 2 parts by weight, and in the range of 0.05 to 1 part by weight with respect to 100 parts by weight of the binder resin. More preferably. There exists a possibility that the reduction effect of the blue light by the said optical film may become inadequate that the addition amount of a said 1st pigment | dye is less than 0.01 weight part. When the added amount of the first dye exceeds 2 parts by weight, the yellow concentration of the dye-containing layer is too high, and the light transmittance of the optical film may not be maintained at a sufficient level.

When the blue second dye is added to the dye-containing layer, the amount of the blue second dye added to the dye-containing layer is 0.005 to 2 with respect to 100 parts by weight of the binder resin. It is preferably in the range of parts by weight, and more preferably in the range of 0.01 to 1 part by weight. The amount of the blue second dye added to the dye-containing layer is preferably less than 100 parts by weight and more preferably less than 80 parts by weight with respect to 100 parts by weight of the first dye. If the amount of the blue second dye added is larger than the above range, the blue density of the dye-containing layer may be too high, and the optical transparency of the optical film may not be maintained at a sufficient level.

When the UV-visible light absorber is added to the dye-containing layer, the amount of the UV-visible light absorber added to the dye-containing layer is 0.01 to 5 parts by weight with respect to 100 parts by weight of the binder resin. It is preferably within the range, and more preferably within the range of 0.2 to 2 parts by weight. There exists a possibility that the reduction effect of the blue light by the said ultraviolet visible light absorber may become inadequate that the addition amount of the said ultraviolet visible light absorber is less than 0.01 weight part. When the addition amount of the UV-visible light absorber exceeds 5 parts by weight, the yellow density of the dye-containing layer becomes too high due to absorption of light (visible light) of 380 nm or more by the UV-visible light absorber, and the optical film There is a possibility that the light transmittance of the glass cannot be maintained at a sufficient level.

The thickness of the dye-containing layer is preferably 3 to 100 μm, more preferably 5 to 50 μm, and even more preferably 5 to 20 μm. If the thickness of the dye-containing layer is less than 3 μm, the surface hardness of the optical film may be insufficient. If the thickness of the dye-containing layer exceeds 100 μm, the amount of raw material necessary to constitute the dye-containing layer increases, which is uneconomical.

The dye-containing layer may be a layer having a pencil hardness of 2H or higher (so-called hard coat layer).

The binder resin contained in the dye-containing layer, the solvent that can be used in the paint used to form the dye-containing layer, the coating method of the paint, the curing method of the paint, and the like can be the same as those of the antiglare layer. In addition, when the optical film of the present invention is arranged in a form in which the dye-containing layer is not exposed, for example, when the dye-containing layer is arranged so as to be in contact with the display screen of the display, it is included in the dye-containing layer. The binder resin to be used may be a thermosetting resin.

[Adhesive layer and release film]
In the optical film of this invention, you may form the adhesive layer for making it adhere on surfaces, such as a display screen of a display, in the surface on the opposite side to the surface where the glare-proof layer is formed. The pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer is preferably a pressure-sensitive adhesive suitable for optical applications, such as an acrylic pressure-sensitive adhesive, a urethane-based pressure-sensitive adhesive, and a silicone-based pressure-sensitive adhesive. The pressure-sensitive adhesive layer may be a self-adsorbing silicone layer. The thickness of the pressure-sensitive adhesive layer is usually in the range of 5 to 100 μm, preferably in the range of 10 to 60 μm.

Furthermore, a release film may be provided on the pressure-sensitive adhesive layer as necessary. Examples of the release film include those obtained by applying a release agent made of silicone resin or the like to various plastic films made of polyethylene terephthalate, polypropylene, or the like. The thickness of the release film is not particularly limited, but is usually in the range of 20 to 150 μm.

Hereinafter, although an example and a comparative example explain the present invention, the present invention is not limited to this.

First, the volume average particle diameter, the CV value, and the refractive index measurement method of the resin particles used in the following examples and comparative examples, and the haze and totality of the optical films obtained in the following examples and comparative examples. A method for measuring light transmittance, pencil hardness, spectral transmittance, average light absorption at a wavelength of 380 nm to 500 nm, and b ^* value, and a method for evaluating glare, antiglare performance, and color reproducibility will be described.

[Measurement method of volume average particle diameter of resin particles and silica particles]
The volume average particle size of the resin particles and silica particles was measured using a laser diffraction / scattering type particle size distribution analyzer (“LS 13 320” manufactured by Beckman Coulter, Inc.) and a universal liquid sample module.

For measurement, 0.1 g of resin particles or silica particles to be measured (hereinafter referred to as “measuring particles”) in 10 ml of a 0.1 wt% nonionic surfactant aqueous solution (manufactured by Yamato Scientific Co., Ltd., Disperse using a “TOUCMIXER MT-31”) and an ultrasonic cleaner (“ULTRASONIC CLEANER VS-150” manufactured by Velvo Crea Co., Ltd.) to obtain a dispersion.

Also, the following optical parameters required for evaluation based on the Mie theory are set in the software of the laser diffraction / scattering type particle size distribution measuring apparatus.

<Parameter>
Refractive index of liquid (nonionic surfactant aqueous solution) I. Real part = 1.333 (refractive index of water)
Real part of refractive index of solid (particle to be measured) = refractive index of particle to be measured Imaginary part of refractive index of solid = 0
Solid form factor = 1
Measurement conditions and measurement procedures are as follows.

<Measurement conditions>
Measurement time: 60 seconds Number of measurements: 1
Pump speed: 50-60%
PIDS relative concentration: about 40-55% Ultrasonic output: 8
<Measurement procedure>
After performing offset measurement, optical axis adjustment, and background measurement, the above-described dispersion liquid is injected into the universal liquid sample module of the laser diffraction / scattering particle size distribution measuring apparatus using a dropper. When the concentration in the universal liquid sample module reaches the PIDS relative concentration and the software of the laser diffraction / scattering particle size distribution measuring apparatus displays “OK”, the measurement is started. The measurement is performed in a state where the particles to be measured are dispersed by performing pump circulation in the universal liquid sample module and an ultrasonic unit (ULM ULTRASONIC MODULE) is activated.

In addition, the measurement is performed at room temperature, and from the obtained data, the software of the laser diffraction / scattering type particle size distribution measuring apparatus is used to set the volume average particle size of the measurement target particle using the preset optical parameters. The diameter (arithmetic mean diameter in the volume-based particle size distribution) is calculated.

When the measurement target particle is a resin particle, the measurement was performed by inputting the refractive index of the polymer constituting the resin particle as the refractive index of the measurement target particle. For example, when the polymer constituting the resin particles is polymethyl methacrylate or polyethyl methacrylate, the known refractive index 1.495 of polymethyl methacrylate and polyethyl methacrylate is input, and the resin particles are In the case where the constituting polymer is polystyrene, a known polystyrene refractive index of 1.595 was input. When the particles to be measured are silica particles, measurement was performed by inputting a known refractive index of 1.45 of the silica particles as the refractive index of the particles to be measured.

[Measurement method of CV value of resin particles and silica particles]
The CV value of the resin particles and silica particles is obtained from the standard deviation (σ) and the volume average particle size (D) of the volume-based particle size distribution measured by the volume average particle size measurement method of the resin particles and silica particles. The following formula CV value (%) = (σ / D) × 100
Calculated by

[Measurement method of refractive index of resin particles]
The refractive index of the resin particles was measured by the Becke method. In this refractive index measurement by the Becke method, resin particles are placed on a slide glass, and a refractive liquid (CARGILLE standard: Cargill standard refractive liquid, a refractive liquid having a refractive index of 1.41 to 1.60 is mixed with a refractive index difference. A plurality of preparations are added dropwise in increments of 0.002. Then, after thoroughly mixing the resin particles and the refractive liquid, from the bottom, while irradiating light from a high-pressure sodium lamp (model number “NX35”, center wavelength 589 nm) manufactured by Iwasaki Electric Co., Ltd. The contour was observed. And when the outline was not visible, it was judged that the refractive index of a refractive liquid and a resin particle is equal.

The observation with an optical microscope is not particularly problematic as long as it is an observation at a magnification at which the outline of the resin particles can be confirmed, but if the resin particles have a particle diameter of 5 μm, it is appropriate to observe at a magnification of about 500 times. . By the above operation, the closer the refractive index of the resin particle and the refractive liquid is, the more difficult it is to see the outline of the resin particle. Therefore, the refractive index of the refractive liquid in which the outline of the resin particle is most difficult to understand is determined to be equal to the refractive index of the resin particle did.

In addition, when there is no difference in the appearance of the resin particles between the two types of refractive liquid having a refractive index difference of 0.002, the intermediate value of the refractive indexes of the two types of refractive liquid is set as the refractive index of the resin particles. Judged. For example, when the test is performed with each of the refractive liquids having the refractive indexes of 1.554 and 1.556, if there is no difference in the appearance of the resin particles between the two refractive liquids, an intermediate value of the refractive index of these refractive liquids is 1.555. Was determined as the refractive index of the resin particles.

[Measurement method of haze and total light transmittance of optical film]
The haze and total light transmittance of the optical film were measured using a haze meter “NDH 4000” manufactured by Nippon Denshoku Industries Co., Ltd. The total light transmittance was measured according to JIS K 7361-1, and the haze was measured according to JIS K 7136. In addition, the haze and total light transmittance which are shown in Table 1 are the average values of the measured value of two measurement samples (measurement sample number n = 2). The haze value increases as the diffusibility of light (transmitted light) transmitted through the optical film increases.

[Method for measuring pencil hardness of optical film]
The pencil hardness test specified in JIS K 5600-5-4: 1999 is applied to the surface of the antiglare layer in the optical film (however, the load applied to the surface against the pencil is JIS K 5600-5-4: 1999). The load of 4.9 N instead of 750 g) was measured, and the hardness of the hardest pencil that did not cause scars was measured, and the measured hardness was taken as the pencil hardness.

[Evaluation method of glare of optical film]
An optical film is placed on the display screen of a tablet computer (trade name “iPad (registered trademark) 2”, manufactured by Apple Inc.) with green displayed on the entire display screen, and the surface of the antiglare layer is on the display screen side. Put the optical film on the opposite side (air side) and lightly press the edge of the optical film with your finger to prevent the optical film from floating, and visually observe the display screen with the optical film on the screen in a dark room. The glare was evaluated according to the following criteria.

(Evaluation criteria for glare)
Glare is not visible: ◎ (very good)
Slight glare: ○ (Good)
A lot of glare can be seen: x (defect)
[Evaluation method of anti-glare performance of optical film]
A bare straight tube fluorescent lamp (8000 cd / m ² ) was placed so that the light was projected onto the optical film at an incident angle of 45 °, and the reflection of the fluorescent lamp when visually observed from the -45 ° direction. The degree was evaluated according to the following criteria, and this evaluation was regarded as the evaluation of antiglare performance.

(Evaluation criteria for reflection of fluorescent light)
Not reflected so much that the outline of the fluorescent lamp is not understood: ◎ (very good)
The outline of the fluorescent lamp can be seen slightly, but it is hardly reflected: ○ (Good)
Fluorescent light is blurred but slightly reflected: △ (somewhat bad)
Fluorescent light is reflected completely: × (defect)
[Evaluation method of color reproducibility of optical film]
An optical film is placed on the display screen of a tablet computer (trade name “iPad (registered trademark) 2”, manufactured by Apple Inc.) with green displayed on the entire display screen, and the surface of the antiglare layer is on the display screen side. Was placed facing the opposite side (air side). The color reproducibility of the image displayed by the tablet computer is visually observed in a dark room while lightly pressing the edge of the optical film with a finger so that the optical film does not float. Sex was evaluated.

(Evaluation criteria for video color reproducibility)
Good color reproducibility: ◎
Slight change in color reproducibility compared with good color reproducibility: ○
Poor color reproducibility: ×
[Measurement Method of Spectral Transmittance of Optical Film, and Average Light Transmittance and Average Light Absorbance of Wavelengths of 380 to 500 nm]
An optical film cut to a plane size of 4 cm × 4 cm was sandwiched between cells, and spectral transmittance at a wavelength of 300 to 800 nm was measured using an ultraviolet-visible spectrophotometer (manufactured by Shimadzu Corporation, trade name “UV-2450”). .

In the spectral transmittance curve obtained by the measurement, the area of the entire wavelength region of 380 nm to 500 nm (the portion sandwiched between the 100% transmittance line and the horizontal axis in the wavelength region of 380 nm to 500 nm) is A, and 380 nm Let B be the area of the transmittance of the optical film in the wavelength region of ˜500 nm (the area of the portion sandwiched between the spectral transmittance curve of the optical film and the horizontal axis in the wavelength region of 380 nm to 500 nm). From these A and B, the following formula: Average light transmittance (%) = (B / A) × 100
Average light absorption rate (%) = {(AB) / A)} × 100
Was used to calculate the average light transmittance and the average light absorption at a wavelength of 380 nm to 500 nm.

[Measurement method of b ^* value of optical film]
The b ^* value of the optical film was measured using a color difference meter “CR-400” (manufactured by Konica Minolta Optics) and a data processor “DP-400” (manufactured by Konica Minolta Optics). Specifically, first, a color difference meter “CR-400” and a data processor “DP-400” were connected. Next, after turning on the color difference meter “CR-400” and data processor “DP-400”, press the “color system” button on the data processor “DP-400” to set the display screen of the Yxy color system. did. Next, the measurement site of the color difference meter “CR-400” is applied to the white calibration plate (X = 84.5, x = 0.3159, y = 0.3227) attached to the color difference meter “CR-400”. The calibration was performed by pressing the “calibration” button of the data processor “DP-400”. After calibration, place an optical film on the white calibration plate, apply the measurement part of the color difference meter “CR-400” to the optical film, perform measurement, and click the “color system” button on the data processor “DP-400”. switch to the L ^* a ^* b ^* display screen of the color system press, read the b ^* value of the L ^* a ^* b ^* color system.

[Example 1]
(Manufacture of antiglare layer-forming coatings)
Crosslinked polymethyl methacrylate particles having a volume average particle diameter of 0.5 μm as resin particles and a CV value of 12% (polymer of monomer mixture comprising 80% by weight of methyl methacrylate and 20% by weight of allyl methacrylate, refraction 1.495) 5 parts by weight (6 parts by weight with respect to 100 parts by weight of the binder resin), 85 parts by weight of pentaerythritol triacrylate (PETA) as the binder resin, and 1-hydroxycyclohexylphenyl as the photopolymerization initiator Mixing 0.5 parts by weight of a ketone (trade name “Irgacure (registered trademark) 184”, manufactured by BASF Japan Ltd.) and 68 parts by weight of toluene as a solvent, Obtained.

(Manufacture of pigment-containing layer-forming paints)
85 parts by weight of pentaerythritol triacrylate (PETA) as a binder resin and 0.17 parts by weight of an oil-soluble dye “DAA51” (manufactured by Yamada Chemical Co., Ltd.) as a first dye (based on 100 parts by weight of the binder resin) 0.2 part by weight), 0.5 part by weight of 1-hydroxy-cyclohexyl phenyl ketone (trade name “Irgacure (registered trademark) 184” manufactured by BASF Japan Ltd.) as a photopolymerization initiator, and toluene as a solvent 68 parts by weight of the mixture was mixed to obtain a pigment-containing layer-forming coating material that was a hard coat coating material.

(Manufacture of optical films)
On one side of a 125 μm thick PET film as a light-transmitting base film, the antiglare layer-forming paint was applied to a bar coater No. The antiglare layer-forming coating material was dried by coating with 07 (manufactured by Daiichi Rika Co., Ltd.) and evaporating the solvent (toluene). Thereafter, the dried coating material for forming an anti-glare layer was cured by irradiating the dried coating material for forming an anti-glare layer with ultraviolet rays for 5 minutes using an ultraviolet irradiation device having an ultraviolet illuminance of 3 W / cm ² . Thereby, the anti-glare layer which has the unevenness | corrugation resulting from a resin particle on the surface on one surface of PET film was formed as a hard-coat layer. The antiglare layer has a thickness of about 10 μm.

Thereafter, a pigment-containing layer-forming coating was applied to the other surface of the PET film with a bar coater No. The pigment-containing layer-forming coating material was dried by coating with 07 (manufactured by Daiichi Rika Co., Ltd.) and evaporating the solvent (toluene). Thereafter, the dried pigment-containing layer-forming coating material was cured by irradiating the dried pigment-containing layer-forming coating material with ultraviolet rays for 5 minutes using an ultraviolet irradiation device having an ultraviolet illuminance of 3 W / cm ² . Thereby, the pigment | dye containing layer was formed as a hard-coat layer on the other surface of PET film, and the optical film of the 3 layer structure which consists of a glare-proof layer, a base film, and a pigment | dye containing layer was obtained. The thickness of the dye-containing layer is about 10 μm. The spectral transmittance of the obtained optical film is shown in FIG.

[Example 2]
As resin particles used in the antiglare layer-forming coating material, instead of the crosslinked polymethyl methacrylate particles having a volume average particle diameter of 0.5 μm and a CV value of 12%, the volume average particle diameter is 5 μm and the CV value is 10%. In the same manner as in Example 1 except that cross-linked polymethyl methacrylate particles (polymer of a monomer mixture consisting of 70% by weight of methyl methacrylate and 30% by weight of ethylene glycol methacrylate, refractive index 1.495) were used. A film was obtained. The spectral transmittance of the obtained optical film was almost the same as the spectral transmittance (FIG. 2) of the optical film obtained in Example 1.

Example 3
As resin particles used for the paint for forming the antiglare layer, instead of the crosslinked polymethyl methacrylate particles having a volume average particle diameter of 0.5 μm and a CV value of 12%, the volume average particle diameter is 1.0 μm and the CV value is 11 % Crosslinked polystyrene particles (monomer mixture polymer consisting of 95% by weight of styrene and 5% by weight of divinylbenzene, refractive index 1.595) were used in the same manner as in Example 1 to obtain an optical film. . The spectral transmittance of the obtained optical film was almost the same as the spectral transmittance (FIG. 2) of the optical film obtained in Example 1.

Example 4
As the first dye used in the paint for forming the dye-containing layer, instead of 0.17 part by weight of “DAA51”, 0.85 part by weight of oil-soluble dye “OIL YELLOW 186” (Chuo Synthetic Chemical Co., Ltd.) (binder resin 100) An optical film was obtained in the same manner as in Example 2 except that 1.0 part by weight) was used. The spectral transmittance of the obtained optical film is shown in FIG.

Example 5
In the same manner as in Example 4, except that the amount of “OIL YELLOW 186” used as the first dye was changed to 0.425 parts by weight (0.5 parts by weight with respect to 100 parts by weight of the binder resin), A film was obtained. The spectral transmittance of the obtained optical film is shown in FIG.

Example 6
Oil-soluble dye "TAP-18" as a blue second dye for the pigment-containing layer forming coating (tetraazaporphyrin compound having a maximum absorption wavelength at a wavelength of 593 nm, manufactured by Yamada Chemical Co., Ltd.) 0.17 weight An optical film was obtained in the same manner as in Example 4, except that 0.2 part by weight (100 parts by weight of the binder resin and 20 parts by weight with respect to 100 parts by weight of the first dye) was added. The spectral transmittance of the obtained optical film is shown in FIG.

Example 7
Instead of 0.17 parts by weight of “DAA51” as the first dye, 0.85 parts by weight of “DAA51” as the first dye (1.0 part by weight with respect to 100 parts by weight of the binder resin) and the first As in Example 1, except that 0.43 parts by weight of “NAZ24” (manufactured by Yamada Chemical Co., Ltd., yellow dye) (0.5 parts by weight with respect to 100 parts by weight of the binder resin) is used. Thus, an optical film was obtained. The spectral transmittance of the obtained optical film is shown in FIG.

Example 8
Instead of 0.17 parts by weight of “DAA51” as the first dye, 1.7 parts by weight of “DAA51” as the first dye (2.0 parts by weight with respect to 100 parts by weight of the binder resin) and the first Optical film in the same manner as in Example 1 except that 0.85 parts by weight (1.0 part by weight with respect to 100 parts by weight of the binder resin) is used as the pigment of “NAZ24” (manufactured by Yamada Chemical Co., Ltd.). Got. The spectral transmittance of the obtained optical film is shown in FIG.

[Comparative Example 1]
An optical film was obtained in the same manner as in Example 1 except that “DAA51” as the first dye was not used. The spectral transmittance of the obtained optical film is shown in FIG.

[Comparative Example 2]
An optical film was obtained in the same manner as in Example 5 except that the crosslinked polymethyl methacrylate particles having a volume average particle diameter of 5 μm and a CV value of 10% as resin particles were not used. The spectral transmittance of the obtained optical film was almost the same as the spectral transmittance (FIG. 4) of the optical film obtained in Example 5.

About the optical films obtained in the above Examples and Comparative Examples, haze, total light transmittance, pencil hardness, average light transmittance at wavelengths of 380 nm to 500 nm, average light absorption at wavelengths of 380 nm to 500 nm, total light transmittance And the difference between the average light transmittance at a wavelength of 380 nm to 500 nm ((total light transmittance) − (average light transmittance at a wavelength of 380 nm to 500 nm)) and b ^* value, as well as glare and antiglare performance, The evaluation results of color reproducibility are shown in Table 1 together with the volume average particle diameter, CV value, refractive index, and addition amount of the resin particles in the above Examples and Comparative Examples, and the type and addition amount of the dye.

As can be seen from the comparison between Example 1 and Comparative Example 1, the optical film of Example 1 maintains a good total light transmittance close to the total light transmittance of the optical film of Comparative Example 1 containing no pigment, In addition, while maintaining good color reproducibility equivalent to that of the optical film of Comparative Example 1 containing no pigment, the average light absorptance at a wavelength of 380 nm to 500 nm can be remarkably improved, and an excellent blue light reduction effect can be obtained. Was.

Further, as can be seen from the comparison between Example 5 and Comparative Example 2, the optical film of Example 5 has a good total light beam that is close to the total light transmittance of the optical film of Comparative Example 2 that does not contain resin particles or silica particles. While maintaining the transmittance and maintaining good color reproducibility equivalent to that of the optical film of Comparative Example 2 containing neither resin particles nor silica particles, the antiglare performance could be remarkably improved.

Further, as can be seen from the comparison between Example 4 and Example 6, the optical film of Example 6 containing the blue second dye is the same as the optical film of Example 4 containing no blue second dye. The b ^* value is reduced while maintaining good total light transmittance close to the light transmittance and maintaining good color reproducibility equivalent to that of the optical film of Example 4 containing no blue second dye. And thus the yellowness could be suppressed.

Further, as can be seen from the comparison between Example 7 and Example 8, the optical film of Example 7 having an average light absorption rate of 40% or less at a wavelength of 380 nm to 500 nm has an average light absorption rate of a wavelength of 380 nm to 500 nm. Compared with the optical film of Example 8 exceeding 40%, the color reproducibility could be improved.

Further, the optical films of Examples 1 to 8 had good haze and pencil hardness, and could prevent the occurrence of glare.

Example 9
Instead of 5 parts by weight of crosslinked polymethyl methacrylate particles as resin particles, 1.6 parts by weight of silica particles having a volume average particle diameter of 8 μm and a CV value of 18% (1.9 parts by weight with respect to 100 parts by weight of binder resin) Part) and 7.0 parts by weight of silica particles having a volume average particle diameter of 2 μm and a CV value of 10% (8.2 parts by weight with respect to 100 parts by weight of the binder resin) (the CV value of the mixture is 30%) ), And instead of 0.85 parts by weight of “DAA51” and 0.43 parts by weight of “NAZ24”, 1.2 parts by weight of “YELLOW 93” (CI Solvent Yellow 93) (binder resin) 1.2 parts by weight) (1.5 parts by weight with respect to 100 parts by weight), 0.9 parts by weight of “NEO SUPER BLUE C-558” (manufactured by Chuo Synthetic Chemical Co., Ltd.) as the second blue dye (by 1.1 parts by weight to Zehnder resin 100 parts by weight, except for adding 73 parts by weight) relative to the first dye 100 parts by weight, in the same manner as in Example 7, to obtain an optical film. The spectral transmittance of the obtained optical film is shown in FIG.

Example 10
In addition to the first dye and the second dye, “ADEKA STAB (registered trademark) LA-F70” as an ultraviolet-visible light absorber (manufactured by ADEKA Corporation, 2,4,6-tris (2-hydroxy-4- An optical film was obtained in the same manner as in Example 9 except that 1 part by weight of hexyloxy-3-methylphenyl) -1,3,5-triazine) was used. The spectral transmittance of the obtained optical film is shown in FIG.

About the optical films obtained in these examples, haze, total light transmittance, pencil hardness, average light transmittance at a wavelength of 380 nm to 500 nm, average light absorption at a wavelength of 380 nm to 500 nm, total light transmittance and a wavelength of 380 nm Difference from the average light transmittance of 500 nm ((total light transmittance) − (average light transmittance at a wavelength of 380 nm to 500 nm)) and b ^* value, as well as glare, anti-glare performance, and color reproducibility The evaluation results are shown in Table 2.

As can be seen from the comparison between Examples 9 and 10 and Comparative Example 1, the optical films of Examples 9 and 10 maintain good color reproducibility equivalent to the optical film of Comparative Example 1 containing no pigment, and While ensuring a higher total light transmittance than the optical film of Comparative Example 1 that does not contain a dye, the average light absorptance at wavelengths of 380 nm to 500 nm can be remarkably improved and has an excellent blue light reduction effect. It was.

Further, as can be seen from the comparison between Examples 9 and 10 and Comparative Example 2, the optical films of Examples 9 and 10 are close to the total light transmittance of the optical film of Comparative Example 2 that does not contain resin particles or silica particles. While maintaining good total light transmittance and maintaining good color reproducibility equivalent to the optical film of Comparative Example 2 containing neither resin particles nor silica particles, the anti-glare performance could be remarkably improved. .

Further, as can be seen from the comparison between Example 2 and Examples 9 and 10, the optical films of Examples 9 and 10 containing silica particles have a wavelength as high as 380 nm, which is equivalent to the optical film of Example 2 containing resin particles. While maintaining an average light absorption rate of 500 nm, the b ^* value could be reduced and the yellowness of the optical film could be suppressed.

[Correction 09.04.2014 based on Rule 91]
Moreover, as can be seen from the comparison between Example 9 and Example 10, the optical film of Example 10 containing the ultraviolet-visible light absorber is compared with the optical film of Example 9 containing no ultraviolet-visible light absorber. The average light absorptance at a wavelength of 380 nm to 500 nm could be further improved, and the blue light reducing effect was further excellent.

Example 11
In this example, the optical film of the embodiment shown in FIG. 10 and FIG. 11 attached to a display having a display screen and a frame surrounding the display screen was produced.

First, a PET film with a thickness of 100 μm was used instead of a PET film with a thickness of 125 μm as a light-transmitting base film, and the antiglare layer described in Example 1 was obtained so that the resulting antiglare layer had a thickness of about 8 μm. An antiglare layer was formed in the same manner as in Example 1 except that the coating for forming the glare layer was applied.

Next, 20 parts by weight of a reactive oligomer (trade name “CN985B88”, aliphatic urethane acrylate, bifunctional, manufactured by Sartomer, USA) as a binder resin and a reactive monomer (trade name “SR238F”, 1,6-hexane) 69 parts by weight of diol diacrylate, bifunctional, manufactured by Sartomer, USA) and 0.85 parts by weight of oil-soluble dye “OIL YELLOW 186” (manufactured by Chuo Synthetic Chemical Co., Ltd.) as the first dye (100 parts by weight of binder resin) 1.0 part by weight with respect to 100 parts by weight of oil-soluble dye “TAP-18” (manufactured by Yamada Chemical Co., Ltd.) as the second blue dye. 2 parts by weight, 20 parts by weight with respect to 100 parts by weight of the first dye) and 1- {4- (2-hydroxyethoxy) as a photopolymerization initiator Phenyl} -2-hydroxy-2-methyl-1-propan-1-one (hydroxy ketones, manufactured by BASF Japan Ltd., trade name “Irgacure (registered trademark) 2959”) and toluene 68 as a solvent By mixing with parts by weight, a paint for forming a dye-containing layer was obtained.

The obtained pigment-containing layer-forming coating material was printed (coated) with an ink jet only on the portion corresponding to the display screen of the display on the other surface (back surface) of the PET film, and the ultraviolet illuminance was 3 W / cm. ^The dried antiglare layer-forming coating material was cured by irradiating ultraviolet rays for 5 minutes with the ultraviolet irradiation device ² . As a result, a pigment-containing layer having a thickness of about 10 μm was formed on the other surface of the PET film.

Then, a pressure-sensitive adhesive layer is formed by coating the other surface (back surface) of the pigment-containing layer and the portion of the PET film where the pigment-containing layer is not formed with a silicone pressure-sensitive adhesive to a thickness of 50 μm. did. Thereby, the target optical film provided with the 4 layer structure shown in FIG. 11 was obtained. The spectral transmittance of the obtained optical film is shown in FIG.

The optical film of the present invention is disposed on a display screen of a display used as a display unit of a tablet personal computer, a display unit of a mobile phone (for example, a smart phone), a display unit of a notebook personal computer, a monitor for a personal computer, or the like. It is useful as an anti-glare film or a protective film that is disposed on a display screen of a display such as a liquid crystal display equipped with an LED as a light source. The optical film of the present invention is also useful as an antiglare film or a protective film disposed on a lens of eyeglasses.

DESCRIPTION OF SYMBOLS 1 Light-transmitting base film 2 Anti-glare layer 3 Dye containing layer 4 Adhesive layer

Claims

A light transmissive substrate film;
An optical film comprising an antiglare layer formed on at least one surface of the base film and including at least one of resin particles and silica particles,
Contains pigments,
The optical film has an average light absorptance of 5% or more at a wavelength of 380 nm to 500 nm,
An optical film, wherein the optical film has a total light transmittance higher than an average light transmittance at a wavelength of 380 nm to 500 nm of the optical film.
2. The optical film according to claim 1, wherein the optical film has an average light absorptance of 45% or less at a wavelength of 380 nm to 500 nm.
3. The optical film according to claim 1, wherein the resin particles are resin particles made of at least one of a (meth) acrylic monomer and a styrene monomer.
The volume average particle diameter of the resin particles is 0.3 to 10 μm,
The optical film according to any one of claims 1 to 3, wherein a coefficient of variation in particle diameter of the resin particles is 20% or less.
The silica particles are a mixture containing first silica particles having a volume average particle diameter of 5 to 10 μm and second silica particles having a volume average particle diameter of 1 to 3 μm.
3. The optical film according to claim 1, wherein a coefficient of variation of the particle diameter of each of the first silica particles and the second silica particles is 20% or less.
The antiglare layer is formed on one surface of the base film,
6. The optical film according to claim 1, wherein a dye-containing layer containing the dye is formed on the other surface of the base film.
The optical film is attached to a display having a display screen and a frame surrounding the display screen,
A dye-containing layer containing the dye and a binder resin is formed on at least one surface of the base film,
The dye-containing layer is formed only on a portion corresponding to a display screen of the display on at least one surface of the base film. Optical film.
The optical film according to any one of claims 1 to 7, wherein the b * value of the optical film is in the range of 5 to 35.
A dye-containing layer containing the dye and a binder resin is formed on at least one surface of the base film,
The dye includes a first dye having a maximum absorption wavelength in the ultraviolet-visible absorption spectrum in the range of 380 to 500 nm, and a blue second dye,
The optical film according to any one of claims 1 to 8, wherein the amount of the blue second dye is less than 100 parts by weight with respect to 100 parts by weight of the first dye.
An ultraviolet-visible light absorber having a maximum absorption wavelength of an ultraviolet-visible absorption spectrum in a range of 320 nm or more and less than 380 nm and having absorption also in a visible region having a wavelength of 380 nm or more is further included. The optical film according to any one of the above.
The antiglare layer further includes a binder resin,
11. The optical system according to claim 1, wherein the amount of the resin particles and / or silica particles is in the range of 1 to 12 parts by weight with respect to 100 parts by weight of the binder resin. the film.