JP2007233329A - Coating material for light diffusion sheet, and the light diffusion sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coating material for light diffusion sheets which will not form hard cakes, excels in storage stability, ensures high light diffusion properties, even when the amount of light diffusing agent is small, and gives a light diffusion sheet which is free of the occurrence of aggregates and partially uneven diffusion in a light diffusion layer and ensures high abrasion resistance of the light diffusion layer, and a light diffusion sheet, having a light diffusion layer composed of a coating film of such a coating material. <P>SOLUTION: The coating material for light diffusion sheets contains a binder resin (A) and polycarbonate resin particles (B) that has an inditerminate form. The light diffusion sheet has a light diffusion layer, having coating film of such a coating material for the light diffusion sheets. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a light diffusion sheet coating material and a light diffusion sheet having a light diffusion layer comprising a coating film of the coating material.

  Conventionally, the light diffusion sheet is used as a material that diffuses the backlight light of the liquid crystal display and uniformly illuminates the entire surface of the liquid crystal display. In recent years, with the widespread use of liquid crystal display televisions, high-quality liquid crystal displays have been required, and high light diffusibility (high haze value) has also been required for this light diffusion sheet.

  As the light diffusing sheet, the surface of the transparent resin sheet is embossed to form irregularities and imparted with light diffusibility, but in order to obtain higher light diffusibility, acrylic resin in the binder resin A light diffusion sheet having a light diffusion layer made of a coating film in which particles are dispersed as a light diffusion agent has been proposed (see, for example, Patent Documents 1 and 2). Since these acrylic resin particles have a relatively high light diffusibility, they are widely used as a light diffusing agent. However, in order to obtain higher light diffusibility, it is necessary to increase the blending amount of the acrylic resin particles. However, when the amount of the acrylic resin particles is increased, aggregates of the light diffusing agent (hereinafter referred to as “buzz”) are formed on the surface of the light diffusing layer, or the light diffusibility of the light diffusing layer is partially non-uniform. Or the like (hereinafter referred to as “unevenness”). Furthermore, when the acrylic resin particles are dispersed in a binder resin and stored in a state diluted with a solvent, the acrylic resin particles settle over time to form a hard cake, which makes it difficult to redisperse and cannot be used. there were.

Further, a light diffusion sheet having a light diffusion layer in which acrylic resin particles and a wax such as polyethylene wax are used in combination as a light diffusion agent has been proposed (for example, see Patent Document 3). In this light diffusion sheet, the occurrence of the above-mentioned irregularities and unevenness is suppressed, but there is a problem that the scratch resistance is not sufficient because a part of the light diffusion layer is peeled off by rubbing the light diffusion layer.
JP 7-218705 A JP-A-9-265004 JP 2001-201614 A

  The problems to be solved by the present invention are excellent in storage stability without producing a hard cake, high light diffusibility can be obtained even with a small amount of light diffusing agent, and no light spots or unevenness occurs in the light diffusing layer. And providing a light diffusing sheet coating material from which a light diffusing sheet having high scratch resistance of the light diffusing layer is obtained, and a light diffusing sheet comprising a light diffusing layer comprising a coating film of the coating material.

  As a result of intensive studies to solve the above problems, the present inventor has produced a hard cake, which is a coating material for a light diffusing sheet in which polycarbonate resin particles having an irregular shape are blended as a light diffusing agent in a binder resin. When the coating material is used, high light diffusibility can be obtained even if the amount of the light diffusing agent is small, and the light diffusing layer is free from unevenness and unevenness. It has been found that a light diffusing sheet having high scratch resistance can be obtained.

  In addition, as a light diffusing agent, in addition to amorphous polycarbonate resin particles, coating materials for light diffusing sheets that also use acrylic resin particles such as acrylic resin particles and acrylic urethane resin particles can be stored stably without producing hard cake. When the coating material is used, high light diffusibility can be obtained even with a small amount of light diffusing agent, no light or unevenness occurs in the light diffusing layer, and the light diffusing layer has high scratch resistance. It has been found that a diffusion sheet can be obtained.

  That is, the 1st aspect of this invention is the coating material for light-diffusion sheets containing binder resin (A) and an amorphous polycarbonate resin particle (B). Moreover, the 2nd aspect of this invention is the coating material for light-diffusion sheets containing binder resin (A), an amorphous polycarbonate resin particle (B), and an acrylic resin particle (C). Furthermore, the present invention provides a light diffusion sheet having a light diffusion layer composed of a coating film of these coating materials.

  The coating material for a light diffusion sheet of the present invention is excellent in storage stability without producing a hard cake, and can be used even after long-term storage. The light diffusing sheet using the coating material provides high light diffusibility even with a small amount of the light diffusing agent, and the light diffusing layer is free from unevenness and unevenness, and the light diffusing layer has scratch resistance. Since it is high, the light diffusion sheet can be produced with a high yield. Furthermore, since the light diffusion sheet of the present invention has high light diffusibility, a liquid crystal display with higher image quality can be realized by using the light diffusion sheet for a backlight for a liquid crystal display.

  The binder resin (A) used in the present invention may be any resin that can form a coating film. From the difference in coating film formation method, solvent evaporation drying resin, thermosetting resin, active energy ray curable resin, etc. Is mentioned. These binder resins can be formed into a coating film by evaporating and drying a solvent, curing by heating, or curing by irradiation with active energy rays such as ultraviolet rays. A resin having high transparency when it becomes a coating film is preferred. Among these resins, the active energy ray-curable resin is preferable because the light diffusing sheet can be obtained with high productivity because of rapid curing.

  The solvent evaporation drying resin is not particularly limited as long as it is a resin soluble in a solvent. For example, urethane resin, cellulose resin, acrylic resin, epoxy resin, polyester resin, and the like can be given. These solvent evaporative drying resins may be used alone or in combination of two or more.

  The thermosetting resin is not particularly limited as long as it is a resin that can be cured by heating. For example, urethane resin, epoxy resin, phenol resin, alkyd resin, unsaturated polyester resin, styrene-maleic acid resin, acrylic resin, melamine resin, urea resin, amino resin, fluorine resin, silicone resin, etc. Can be mentioned. These thermosetting resins may be used alone or in combination of two or more.

  The active energy ray-curable resin is not particularly limited as long as it is a compound that can be cured by irradiation with active energy rays such as ultraviolet rays and electron beams. For example, urethane (meth) acrylate (A1), radical polymerizable monomer, epoxy (meth) acrylate and the like can be mentioned. These active energy ray-curable resins may be used alone or in combination of two or more. In the present invention, “(meth) acrylate” refers to one or both of methacrylate and acrylate.

  The urethane (meth) acrylate (A1) is prepared by, for example, reacting a polyol (a1) with a polyisocyanate (a2) and a compound (a3) having a polymerizable unsaturated group and a hydroxyl group at the terminal, or a polyisocyanate (a2). ) And a compound having a polymerizable unsaturated group and a hydroxyl group at the terminal (a3).

  Examples of the polyol (a1) include polyester polyols obtained by polycondensation of polybasic acids and polyhydric alcohols; polyester polyols obtained by ring-opening polymerization of lactones such as ε-caprolactone and γ-valerolactone; Polyether polyols which are polymers of cyclic ethers such as alkylene oxides such as ethylene oxide, propylene oxide and butylene oxide, tetrahydrofuran and alkyl-substituted tetrahydrofuran, or copolymers of two or more of these; Bisphenol A and alkylene oxide adducts of bisphenol A Etc. Furthermore, the isocyanurate type | system | group polyol which added lactone and alkylene oxide to the triisocyanate which is the trimer of the following diisocyanate is also mentioned.

  Examples of the polyisocyanate compound (a2) include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4′-diphenylmethane diisocyanate, hydrogenated 4,4′-diphenylmethane diisocyanate, xylylene diisocyanate, Hydrogenated xylylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, 1,5-naphthalene diisocyanate, tolidine diisocyanate, phenylene diisocyanate, transcyclohexane-1,4-diisocyanate, lysine diisocyanate, tetramethylxylene diisocyanate, lysine ester triisocyanate, 1, 6,11-undecane triisocyanate, 1,8-diisocyanate-4-isocyanatomethyl ester Tan, 1,3,6-hexamethylene triisocyanate, bicycloheptane triisocyanate, trimethylhexamethylene diisocyanate, dicyclopentadiene diisocyanate, norbornene diisocyanate, triisocyanate and the like is trimer of hexamethylene diisocyanate.

  Examples of the compound (a3) having a polymerizable unsaturated group and a hydroxyl group at the terminal include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meta). ) Acrylate, 2- (meth) acryloyloxyethyl-2-hydroxyethylphthalic acid, pentaerythritol tri (meth) acrylate, 3-acryloyloxyglycerin mono (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 2-hydroxy -1- (meth) acryloxy-3- (meth) acryloxypropane, glycerin di (meth) acrylate, polypropylene glycol mono (meth) acrylate, polyethylene glycol mono (meth) acrylate, poly ε-caprolactone (Meth) acrylate, 4-hydroxybutyl (meth) acrylate, tri-hydroxyethyl isocyanurate di (meth) acrylate, .epsilon.-caprolactone mono (meth) acrylate, various types of epoxy (meth) acrylate.

  Among the urethane (meth) acrylate (A1), urethane (meth) acrylate having an isocyanurate ring is particularly preferable because it improves the scratch resistance of the light diffusion sheet. Examples of the urethane (meth) acrylate having an isocyanurate ring include urethane acrylate obtained by reacting triisocyanate, which is a trimer of hexamethylene diisocyanate, with 2-hydroxyethyl acrylate.

  As the radical polymerizable monomer, any of a monofunctional polymerizable monomer, a bifunctional polymerizable monomer, and a polyfunctional polymerizable monomer can be used. These radically polymerizable monomers may be used alone or in combination of two or more.

  Examples of the monofunctional polymerizable monomer include methoxyethylene glycol (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, β- (meth) acryloyloxyethyl hydrogen phthalate, β- (meth) acryloyloxyethyl hydrogen succinate, Nonylphenoxyethyl (meth) acrylate, nonylphenoxypolyoxyethylene (meth) acrylate, nonylphenoxypolyoxypropylene (meth) acrylate, 3-chloro-2-hydroxypropyl (meth) acrylate, phenoxyethyl (meth) acrylate, phenoxypolyethylene Glycol (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, β- (meth) acryloyloxypropyl hydro N-phthalate, β- (meth) acryloyloxypropyl hydrogen succinate, butoxypolyethylene glycol (meth) acrylate, alkyl (meth) acrylate, cyclohexyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, isobornyl (meth) acrylate, benzyl (Meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, 2- (meth) acryloyloxyethyl-2-hydroxyethylphthal Acid, 3-acryloyloxyglycerin mono (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 2-hydroxy-1- (meth) acryloxy-3- ( (Meth) acryloxypropane, polypropylene glycol mono (meth) acrylate, polyethylene glycol mono (meth) acrylate, polyε-caprolactone mono (meth) acrylate, dialkylaminoethyl (meth) acrylate, glycidyl (meth) acrylate, mono [2- (Meth) acryloyloxyethyl] acid phosphate, trifluoroethyl (meth) acrylate, 2,2,3,3-tetrafluoropropyl (meth) acrylate, 2,2,3,4,4,4-hexafluorobutyl (Meth) acrylate, perfluorooctylethyl (meth) acrylate, dicyclopentenyloxyalkyl (meth) acrylate, dicyclopentenyl (meth) acrylate, tricyclodecanyl (meth) acrylate, tricyclo Crab oxyethyl (meth) acrylate, isobornyl oxyethyl (meth) acrylate, N- vinylpyrrolidone, 2-vinylpyridine, morpholine (meth) acrylate, N- vinyl caprolactam. These monofunctional polymerizable monomers may be used alone or in combination of two or more.

  Examples of the bifunctional polymerizable monomer include 2,2-dimethyl-3-hydroxypropyl-2,2-dimethyl-3-hydroxypropionate di (meth) acrylate, ethylene glycol di (meth) acrylate, and polyethylene. Glycol di (meth) acrylate, propylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, glycerin di ( Meth) acrylate, neopentyl glycol di (meth) acrylate, di (meth) acrylate of neopentyl glycol hydroxypivalate, di (meth) acrylate of bisphenol A ethylene oxide adduct, bisphenol A pro Di (meth) acrylate of lenoxide adduct, di (meth) acrylate of 2,2′-di (hydroxypropoxyphenyl) propane, di (meth) acrylate of 2,2′-di (hydroxyethoxyphenyl) propane, bisphenol F Di (meth) acrylate of ethylene oxide adduct, di (meth) acrylate of propylene oxide adduct of bisphenol F, 3,9-bis (1,1-dimethyl-2-hydroxyethyl) -2,4,8,10 -Di (meth) acrylate of tetraoxaspiro [5.5] undecane, di (5-ethyl-2- (2-hydroxy-1,1-dimethylethyl) -5- (hydroxymethyl) -1,3 dioxane ( And (meth) acrylate.

  Examples of the polyfunctional polymerizable monomer include trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, tetramethylolmethanetri ( (Meth) acrylate, tetramethylolmethane tetra (meth) acrylate, tris (2-hydroxyethyl) isocyanurate tri (meth) acrylate, tris (hydroxypropyl) isocyanurate tri (meth) acrylate, trimellitic acid tri (meta) ) Acrylate, triallyl trimellitic acid, triallyl isocyanurate and the like. These polyfunctional polymerizable monomers may be used alone or in combination of two or more.

  Said polyfunctional polymerizable monomer may be used independently or may use 2 or more types together. In addition, it is preferable to use a polyfunctional polymerizable monomer because the coating film can be hardened as compared with a monofunctional polymerizable monomer or a bifunctional polymerizable monomer, and the scratch resistance can be improved.

  As said epoxy (meth) acrylate, what added (meth) acrylic acid to the polyglycidyl ether obtained by making the said polyol (a1) and epichlorohydrin react by dehydrochlorination reaction is mentioned, for example.

  In the present invention, when an active energy ray-curable resin is used as the binder resin (A) and curing is performed by ultraviolet irradiation, a photopolymerization initiator is blended in a coating material for a light diffusion sheet.

  The photopolymerization initiator can be roughly classified into an intramolecular cleavage type photopolymerization initiator and a hydrogen abstraction type photopolymerization initiator. Examples of the intramolecular cleavage type photopolymerization initiator include diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzyldimethyl ketal, 1- (4-isopropylphenyl) -2-hydroxy. 2-methylpropan-1-one, 4- (2-hydroxyethoxy) phenyl- (2-hydroxy-2-propyl) ketone, 1-hydroxycyclohexylphenylketone, 2-methyl-2-morpholino- (4-thio Acetophenone compounds such as methylphenyl) propan-1-one and 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) butanone; benzoin compounds such as benzoin, benzoin methyl ether and benzoin isopropyl ether; 4,6-trimethylbenzoyldiphenyl Scan fins oxide, bis (2,4,6-trimethylbenzoyl) - acyl phosphine oxide-based compounds such as triphenylphosphine oxide; benzyl, compounds such as methyl phenylglyoxylate ester.

  On the other hand, examples of the hydrogen abstraction type photopolymerization initiator include benzophenone, methyl 4-phenylbenzophenone, o-benzoylbenzoate, 4,4′-dichlorobenzophenone, hydroxybenzophenone, 4-benzoyl-4′-methyl-diphenyl sulfide. Benzophenone compounds such as acrylated benzophenone, 3,3 ′, 4,4′-tetra (t-butylperoxycarbonyl) benzophenone, 3,3′-dimethyl-4-methoxybenzophenone; 2-isopropylthioxanthone, 2,4 A thioxanthone compound such as dimethylthioxanthone, 2,4-diethylthioxanthone, and 2,4-dichlorothioxanthone; an aminobenzophenone compound such as Michler's ketone and 4,4′-diethylaminobenzophenone; 2-chloro acridone, 2-ethyl anthraquinone, 9,10-phenanthrenequinone, include compounds such as camphor quinone.

  0.1-20 mass parts is preferable with respect to 100 mass parts of active energy ray-curable resins, and, as for the usage-amount of these photoinitiators, 0.5-10 mass parts is more preferable.

  The polycarbonate resin constituting the amorphous polycarbonate resin particles (B) used in the present invention is a polycarbonate resin or carbonate prepolymer obtained by reacting a dihydric phenol and a carbonate precursor by an interfacial polycondensation method or a melt transesterification method. A polycarbonate resin obtained by polymerizing the compound by a solid phase transesterification method, a polycarbonate resin obtained by polymerizing the cyclic carbonate compound by a ring-opening polymerization method, and the like. As such a polycarbonate resin, for example, a polycarbonate resin produced by an interfacial polycondensation method using 2,2-bis (4-hydroxyphenyl) propane (bisphenol A) as a dihydric phenol and phosgene as a carbonate precursor is used. Can be mentioned.

  The amorphous polycarbonate resin particles (B) preferably have a number average molecular weight of 5,000 to 100,000, more preferably 7,500 to 75,000, and 10,000 to 50,000. Further preferred. When the number average molecular weight is within this range, the solvent resistance increases. In addition, polycarbonate resin particles having an aromatic ring are particularly preferable because they have high light diffusibility and excellent scratch resistance.

The shape of the polycarbonate resin particles (B) is indefinite. In the present invention, the indeterminate shape means that the surface of the resin particle has unevenness, that is, the particle projection image has unevenness. The particle projection image is an image obtained by viewing particles from one direction. Among the irregular shapes, those having a sphericity defined by the following formula in the range of 0.50 to 0.94 are preferable.
Circularity of particle projection image = (circumference of a circle having the same area as the particle projection area) / (perimeter of particle projection image)
Average value of circularity of particle projection image = sphericity of spherical particles

  Furthermore, the sphericity of the amorphous polycarbonate resin particles (B) is more preferably in the range of 0.70 to 0.92, and more preferably in the range of 0.75 to 0.90. The sphericity can be measured using, for example, a flow type particle image analyzer “FPIA-3000S” manufactured by Sysmex Corporation. Moreover, since the polycarbonate resin particle (B) has such an irregular shape, it is considered that the light diffusibility is enhanced.

  Further, the method of making the polycarbonate resin into amorphous particles is not particularly limited as long as it is a method capable of forming particles with an irregular shape. For example, a mechanical grinding method or a chemical grinding method is mentioned. As a mechanical pulverization method, a method of mechanically pulverizing at normal temperature is common, but a freeze pulverization method in which a polycarbonate resin is instantaneously frozen and embrittled with a refrigerant such as liquid nitrogen may be used. it can.

  On the other hand, in the chemical pulverization method, the polycarbonate resin is heated and dissolved in a good solvent, and then cooled with stirring, or the poor solvent is added to the resin solution while stirring, or the resin solution is dropped while stirring in the poor solvent. In this method, the solubility of the polycarbonate resin in the good solvent is lowered and precipitated as particles. Examples of the good solvent used in the chemical pulverization method include ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; halogenated hydrocarbons such as dichloromethane, chloroform, and tetrachloromethane. Examples of the poor solvent include aromatic hydrocarbons such as benzene, toluene, xylene, and tetralin; aliphatic hydrocarbons such as hexane and cyclohexane; alcohols such as methanol, ethanol, isopropanol, and n-butanol; acetic acid Examples include esters such as ethyl and butyl acetate.

  Among the above pulverization methods, if the chemical pulverization method is used in which the polycarbonate resin is dissolved in a good solvent by heating and then dropped into a poor solvent with stirring, the particles are precipitated as particles. This is preferable because it can be shaped into particles and has high light diffusibility.

  The amorphous polycarbonate resin particles (B) preferably have an average particle size of 0.1 to 20 μm, more preferably 0.1 to 10 μm, and particularly preferably 1 to 8 μm. When the average particle size is within this range, the haze is high and the light diffusibility is improved.

  In the present invention, the average particle diameter means a median diameter (d50) obtained by measuring the particle size distribution by a laser diffraction / scattering method. Moreover, as a device for measuring the particle size distribution by the laser diffraction / scattering method, “Microtrack” series manufactured by Nikkiso Co., Ltd. can be mentioned.

  The acrylic resin particles (C) used in the present invention are used as a light diffusing agent in the same manner as the amorphous polycarbonate resin particles (B). Examples of the acrylic resin particles (C) include acrylic resin particles (C1) and acrylic urethane resin particles (C2). Examples of the acrylic resin particles (C1) include (meth) acrylate polymers. The (meth) acrylate polymer is a polymer obtained by polymerizing (meth) acrylate. Examples of the (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, and propyl (meth) acrylate. ) Acrylate, butyl (meth) acrylate and the like. These (meth) acrylates may be used alone or in combination of two or more. In addition to these (meth) acrylates, an aromatic vinyl monomer such as styrene, vinyltoluene, α-methylstyrene, or halogenated styrene may be used in combination for polymerization. Furthermore, polymerization may be performed using a crosslinkable monomer such as allyl methacrylate or triallyl cyanurate in combination.

  The acrylic urethane resin particles (C2) were obtained by polymerizing an acrylic resin particle having a hydroxyl group treated with an isocyanate or a compound having a hydroxyl group and an isocyanate-treated acrylic resin particle having a hydroxyl group and a polyurethane resin particle. Examples include urethane resin particles coated with acrylic resin.

  The acrylic resin particles (C) preferably have an average particle size of 1 to 30 μm, more preferably 5 to 20 μm. When the average particle size is within this range, the haze is high and the light diffusibility is improved.

  In addition, it is preferable that the acrylic resin particles (C) have a spherical shape because high light diffusibility and high light transmittance can be obtained by using together with the amorphous polycarbonate resin particles. In the present invention, the spherical shape means that the sphericity is 0.95 or more.

  As for the compounding quantity of the amorphous polycarbonate resin particle (B) with respect to 100 mass parts of binder resin (A), 1-100 mass parts is preferable. Moreover, in order to make high light diffusibility and high light transmittance compatible, the compounding quantity of the amorphous polycarbonate resin particle (B) with respect to 100 parts by mass of the binder resin (A) is preferably 5 to 50 parts by mass, 35 mass parts is more preferable, and 10-14 mass parts is further more preferable.

  When the amorphous polycarbonate resin particles (B) and the acrylic resin particles (C) are used in combination, the amorphous polycarbonate resin particles (B) and the acrylic resin particles (C) with respect to 100 parts by mass of the binder resin (A). 5-80 mass parts is preferable, as for a total compounding quantity, 10-60 mass parts is more preferable, and 15-60 mass parts is further more preferable. When the blending amount of the amorphous polycarbonate resin particles (B) and the acrylic resin particles (C) is within this range, high light diffusibility and high light transmittance can be obtained.

  Furthermore, the blending ratio of the amorphous polycarbonate resin particles (B) and the acrylic resin particles (C) is (B) :( C) on a mass basis so as to obtain the desired light diffusibility (haze value). = 5: 95 to 95: 5. When higher light diffusibility is required, the range of (B) :( C) = 55: 45 to 90:10 is preferable on a mass basis.

  You may mix | blend organic resin particles other than the said amorphous polycarbonate resin particle (B) and acrylic resin particle (C) with the coating agent for light-diffusion sheets of this invention. Examples of such organic resin particles include polyurethane resin particles, polyvinyl chloride resin particles, polystyrene resin particles, polyacrylonitrile resin particles, polyamide resin particles, silicone resin particles, polytetrafluoroethylene resin particles, and the like.

  In addition to the binder resin (A), the amorphous polycarbonate resin particles (B), and the acrylic resin particles (C), the coating material for the light diffusion sheet of the present invention includes a silicone leveling agent and a reactive silicone as necessary. Additives such as system leveling agents, fluorine leveling agents, reactive fluorine leveling agents, and antistatic agents may be added.

  When a silicone leveling agent, a reactive silicone leveling agent, a fluorine leveling agent or a reactive fluorine leveling agent is blended in the coating material for a light diffusing sheet of the present invention, each blending amount is the binder resin (A). 0.1-5 mass parts is preferable with respect to 100 mass parts. If it is this range, a uniform coating film without a coating-film defect can be formed.

  Examples of the antistatic agent include surfactants, lithium salts, inorganic oxide sols, inorganic conductive fine particles, and organic conductive polymer fine particles. Among them, lithium salts, inorganic conductive fine particles, organic Since the conductive polymer fine particles are not easily affected by the humidity in the air, they are preferable because they can impart a stable antistatic property to the coating film. Moreover, when mix | blending these antistatic agents with the coating material for light diffusion sheets of this invention, the compounding quantity has preferable 1-50 mass parts with respect to 100 mass parts of said binder resins (A).

  The manufacturing method of the light-diffusion sheet using the coating material for light-diffusion sheets of this invention can be selected suitably. For example, after applying the coating material to a substrate using a bar coater, die coater, gravure coater, etc., after removing the solvent in the coating material in a heating furnace at 40 to 60 ° C. or on a hot plate or hot roller And a method of forming a light-diffusing layer comprising a coating film of the coating material on a substrate by forming a coating film under the condition that the binder resin (A) forms a coating film.

  Examples of the material of the base material used in the light diffusion sheet of the present invention include polyester resins such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate; polyolefin resins such as polypropylene, polyethylene, and polymethylpentene-1; Cellulose resin: polystyrene resin, polyamide resin, polycarbonate resin, norbornene resin (for example, “ZEONOR” manufactured by ZEON CORPORATION), modified norbornene resin (for example, “ARTON” manufactured by JSR Corporation), cyclic olefin Examples thereof include polymers (for example, “Appel” manufactured by Mitsui Chemicals, Inc.) Two or more kinds of base materials of these materials may be bonded together, and these base materials are in the form of a film or a sheet. The thickness is 20-500 m is preferable.

  Moreover, when applying the coating material for light diffusing sheets of the present invention to a substrate, the coating material may be diluted with a solvent in order to obtain a viscosity suitable for application. Examples of the solvent used for dilution include aromatic hydrocarbons such as toluene and xylene; alcohols such as methanol, ethanol and isopropyl alcohol; esters such as ethyl acetate and ethyl sorbacetate; methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone. Examples include ketones. These solvents may be used alone or in combination of two or more.

  The film thickness of the light diffusion layer comprising the coating film of the coating material for light diffusion sheet of the present invention is preferably 1 to 40 μm, more preferably 1 to 30 μm, and particularly preferably 3 to 20 μm. If the film thickness of the light diffusion layer is within this range, it is preferable because high light diffusibility and light transmittance can be obtained.

  The present invention will be specifically described below with reference to examples and comparative examples.

(Synthesis Example 1)
A flask equipped with a stirrer, a thermometer, and a reflux condenser was charged with 504 parts by mass of triisocyanate, which is a trimer of hexamethylene diisocyanate, heated to 70 ° C. while stirring, and 348 parts by mass of 2-hydroxyethyl acrylate was added. It was made to react dropwise over 1 hour, and it reacted until residual NCO% became 0.1% or less, and the trifunctional urethane acrylate which has the isocyanuric acid frame | skeleton which is a viscous pale yellow liquid liquid was obtained.

Example 1
100 parts by mass of the trifunctional urethane acrylate obtained in Synthesis Example 1, a solvent dispersion of polycarbonate resin particles (“Hi-flat ZE-31” manufactured by Gifu Serac Manufacturing Co., Ltd., methyl ethyl ketone / cyclohexanone / n-butyl acetate = 58/25 / 10 dispersion of amorphous polycarbonate resin particles (hereinafter referred to as “PC resin particles (1)”) having an average particle size of 5.1 μm and a sphericity of 0.79 in a mixed solvent of / 10. 115 After mixing and stirring 5 parts by mass (8 parts by mass as PC resin particles (1)) and 5 parts by mass of a photopolymerization initiator (1-hydroxycyclohexyl phenyl ketone), the coating material is diluted with ethyl acetate and has a nonvolatile content of 30% by mass. (1) was obtained. The PC resin particles (1) are prepared by a chemical pulverization method in which a resin solution in which a polycarbonate resin is dissolved in cyclohexanone is heated and dropped into a mixed solvent of methyl ethyl ketone and n-butyl acetate with stirring, and precipitated as particles. It is manufactured.

(Examples 2 to 5)
In the same manner as in Example 1 except that the blending number of the PC resin particles (1) used in Example 1 was changed to 10 parts by mass, 12 parts by mass, 14 parts by mass, or 20 parts by mass. ) To (5) were obtained.

(Examples 6 to 7)
Similar to Example 1, except that the blending number of PC resin particles (1) used in Example 1 was changed to 30 parts by mass or 35 parts by mass and diluted with ethyl acetate so that the nonvolatile content was 20% by mass. Thus, coating materials (6) to (7) were obtained.

(Example 8)
Mixing of 100 parts by mass of the trifunctional urethane acrylate obtained in Synthesis Example 1 and a solvent dispersion of polycarbonate resin particles (“Hi-flat ZF-80” manufactured by Gifu Seratech Manufacturing Co., Ltd., cyclohexanone / n-butyl acetate = 30/63) 171.4 parts by mass of 7% by mass of amorphous polycarbonate resin particles having an average particle size of 5.3 μm and a sphericity of 0.90 (hereinafter referred to as “PC resin particles (2)”) dispersed in a solvent. (12 parts by mass as PC resin particles (2)) and 5 parts by mass of a photopolymerization initiator (1-hydroxycyclohexyl phenyl ketone) were mixed and stirred, and then diluted with ethyl acetate to obtain a coating material (8 ) The PC resin particles (2) were produced by a chemical pulverization method in which a resin solution obtained by heating and dissolving a polycarbonate resin in cyclohexanone was dropped into a mixed solvent with n-butyl acetate while stirring, and precipitated as particles. Is.

Example 9
171.4 parts by mass of the solvent dispersion of the PC resin particles (2) used in Example 8 was added to the solvent dispersion of polycarbonate resin particles (“High Flat ZG-05”, cyclohexanone / acetate n, manufactured by Gifu Seratech Manufacturing Co., Ltd.). -Amorphous polycarbonate resin particles (hereinafter referred to as “PC resin particles (3)”) having an average particle diameter of 7.9 μm and a sphericity of 0.86 in a mixed solvent of butyl / isobutyl acetate = 30/13/50. 5 wt% dispersed.) A coating material (9) was obtained in the same manner as in Example 8, except that the amount was changed to 240 parts by mass (12 parts by mass as PC resin particles (3)). The PC resin particles (3) are produced by a chemical pulverization method in which a resin solution in which a polycarbonate resin is dissolved in cyclohexanone is heated and dropped into a mixed solvent of n-butyl acetate / isobutyl acetate and precipitated as particles. It is a thing.

(Example 10)
100 parts by mass of the trifunctional urethane acrylate used in Example 3 and 70 parts by mass of the trifunctional urethane acrylate and 30 parts by mass of dipentaerythritol hexaacrylate (“Kayarad DPHA” manufactured by Nippon Kayaku Co., Ltd .; hereinafter referred to as “DPHA”). A coating material (10) was obtained in the same manner as in Example 3 except that the combination with the part was used.

(Example 11)
Acrylic polyol ("Placcel DC2209" manufactured by Daicel Chemical Industries, Ltd., lactone-modified acrylic polyol, nonvolatile content 50% by weight) 180 parts by weight (90 parts by weight as nonvolatile content) and dibutyltin dilaurate ("Neostan U-" manufactured by Nitto Kasei Co., Ltd.) 100 ", non-volatile content 0.38% by mass) 4 parts by mass, and 171.4 parts by mass of the same PC resin particle (1) solvent dispersion as used in Example 1 (12 masses as PC resin particles (1)) Part) was mixed and stirred, and then diluted with ethyl acetate to obtain a coating material (11) having a nonvolatile content of 35% by mass. The coating material (11) was used by adding a polyisocyanate described later before being applied to the substrate.

(Example 12)
100 parts by mass of trifunctional urethane acrylate obtained in Synthesis Example 1, acrylic resin particles (“MB30X-8” manufactured by Sekisui Plastics Co., Ltd., highly crosslinked polymethyl methacrylate resin particles, average particle size: 8 μm, shape: spherical, Sphericality: 0.97) 25 parts by mass, 115 parts by mass of the same PC resin particle (1) solvent dispersion as used in Example 1 (8 parts by mass as PC resin particles (1)), and photopolymerization 5 parts by mass of an initiator (1-hydroxycyclohexyl phenyl ketone) was mixed and stirred, and then diluted with ethyl acetate to obtain a coating material (12) having a nonvolatile content of 40% by mass.

(Example 13)
100 parts by mass of a thermoplastic acrylic polymer (“Pararoid B48N” manufactured by Rohm and Haas) was dissolved in 150 parts by mass of methyl ethyl ketone to obtain 250 parts by mass of a resin solution. Next, 250 parts by mass of the resin solution, 25 parts by mass of the same acrylic resin particles as used in Example 12, and 115 parts by mass of a solvent dispersion of the same PC resin particles (1) as used in Example 1 (PC 8 parts by mass as resin particles (1) were mixed and stirred, and then diluted with ethyl acetate to obtain a coating material (13) having a nonvolatile content of 30%.

(Example 14)
Acrylic polyol ("Placcel DC2209" manufactured by Daicel Chemical Industries, Ltd., lactone-modified acrylic polyol, non-volatile content 50% by mass) 180 parts by mass (90 parts by mass as non-volatile content), dibutyltin dilaurate ("Neostan U-" manufactured by Nitto Kasei Corporation) 100 ”, non-volatile content 0.38% by mass) 4 parts by mass, 25 parts by mass of the same acrylic resin particles as used in Example 12, and solvent dispersion of the same PC resin particles (1) as used in Example 1 After 115 parts by mass of the liquid (8 parts by mass as PC resin particles (1)) was mixed and stirred, it was diluted with ethyl acetate to obtain a coating material (14) having a nonvolatile content of 35% by mass. The coating material (14) was used by adding a polyisocyanate described later before being applied to the substrate.

(Example 15)
Instead of the acrylic resin particles used in Example 12, acrylic urethane resin particles (“BC79” manufactured by Gifu Seratech Manufacturing Co., Ltd., average particle size: 8 μm, shape: spherical, sphericity: 0.97) were used. A coating material (15) having a nonvolatile content of 40% by mass was obtained in the same manner as Example 12 except for the above.

(Examples 16 to 19)
Coating with a nonvolatile content of 40% by mass in the same manner as in Example 12 except that the blending number of the acrylic resin particles used in Example 12 was changed to 10 parts by mass, 20 parts by mass, 30 parts by mass, or 50 parts by mass. Materials (16) to (19) were obtained.

(Examples 20 and 21)
The coating material (20) having a non-volatile content of 40% by mass and the same as in Example 18 except that the blending number of the PC resin particles (1) used in Example 18 was changed to 2 parts by mass or 6 parts by mass. 21) was obtained.

(Comparative Example 1)
100 parts by mass of the trifunctional urethane acrylate obtained in Synthesis Example 1, 12 parts by mass of the same acrylic resin particles as used in Example 12, and 5 parts by mass of a photopolymerization initiator (1-hydroxycyclohexyl phenyl ketone) are mixed and stirred. Then, it diluted with ethyl acetate and obtained the coating material (C1) of 45 mass% of non volatile matters.

(Comparative Example 2)
Instead of the acrylic resin particles used in Comparative Example 1, styrene resin particles (“SBX-12” manufactured by Sekisui Plastics Co., Ltd., crosslinked polystyrene resin particles, average particle size: 12 μm, shape: spherical, sphericity: 0 .97) was used in the same manner as in Comparative Example 1 to obtain a coating material (C2) having a nonvolatile content of 45% by mass.

(Comparative Example 3)
Instead of the acrylic resin particles used in Comparative Example 1, a solvent dispersion of microcrystalline wax (hereinafter referred to as “wax”) (“XD-448” manufactured by Gifu Seratsuk Co., Ltd.), solid paraffin in n-butyl acetate In the same manner as in Comparative Example 1 except that 120 parts by mass (12 parts by mass as wax) was used, a coating material (C3) having a nonvolatile content of 45% by mass was obtained.

(Comparative Example 4)
In place of the acrylic resin particles used in Comparative Example 1, silica beads (“KE-P10” manufactured by Nippon Shokubai Co., Ltd.) were used in the same manner as in Comparative Example 1, except that the coating material (C4 )

(Comparative Example 5)
Coating was performed in the same manner as in Comparative Example 1 except that the blending amount of the acrylic resin particles used in Comparative Example 1 was changed from 12 parts by mass to 33 parts by mass and diluted with ethyl acetate so that the nonvolatile content was 40% by mass. A material (C5) was obtained.

(Comparative Example 6)
The acrylic resin particles used in Comparative Example 1 were replaced with the same acrylic urethane resin particles as used in Example 15, and the same procedure as in Comparative Example 1 was conducted except that the non-volatile content was diluted with ethyl acetate so as to be 40% by mass. Thus, a coating material (C6) was obtained.

(Comparative Example 7)
Coating was performed in the same manner as in Comparative Example 1 except that the blending amount of the acrylic resin particles used in Comparative Example 1 was changed from 12 parts by mass to 100 parts by mass and diluted with ethyl acetate so that the nonvolatile content was 40% by mass. A material (C7) was obtained.

(Comparative Example 8)
Instead of the PC resin particles (1) used in Example 12, the same styrene resin particles as those used in Comparative Example 2 were used in the same manner as in Example 12 except that the coating material (non-volatile content 40 mass%) C8) was obtained.

(Comparative Example 9)
In place of the PC resin particles (1) used in Example 12, 80 parts by mass of the same solvent dispersion of wax (8 parts by mass as wax) as used in Comparative Example 3 was used. Thus, a coating material (C9) having a nonvolatile content of 40% by mass was obtained.

(Comparative Example 10)
Instead of the PC resin particles (1) used in Example 12, the same silica beads as those used in Comparative Example 4 were used, and the coating material (C10 )

  In addition, the coating materials (1) to (10), (12), (15) to (21) and (C1) to (C10) prepared above are ultraviolet curable coating materials, and the coating materials (11) and (11) (14) is a thermosetting coating material, and the coating material (13) is a solvent evaporation drying type coating material.

(Measurement of average particle diameter of resin particles)
The average particle diameter of the resin particles (PC resin particles (1) to (3), acrylic resin particles, acrylic urethane resin particles, and styrene resin particles) used in Examples and Comparative Examples is determined by measuring the particle size distribution of each resin particle. (Nikkiso Co., Ltd. “Microtrac FRA”) was used to measure the particle size distribution, and the median diameter (d50) of the obtained particle size distribution was defined as the average particle size.

(Measurement of sphericity of resin particles)
The sphericity of the resin particles (PC resin particles (1) to (3), acrylic resin particles, acrylic urethane resin particles, and styrene resin particles) used in Examples and Comparative Examples was measured by the following method. First, as a sample for measuring sphericity, a solvent dispersion of PC resin particles (1) to (3), acrylic resin particles, acrylic urethane resin particles, or styrene resin particles are diluted with ethyl acetate, and then ultrasonic vibration is performed. Dispersion was carried out using a vessel to prepare a dispersion of resin particles of 0.014% by mass of resin particles. Next, the circularity of the prepared dispersion of resin particles was measured using a flow type particle image analyzer (“FPIA-3000S” manufactured by Sysmex Corporation), and the sphericity of each resin particle was determined from the average of the circularity. Asked.

(Optical microscope observation of resin particles)
The amorphous polycarbonate particles (PC resin particles (1)) used in the examples were observed using an optical microscope ("Digital Microscope VHX-200" manufactured by Keyence Corporation, magnification: 3000 times). A photomicrograph of the amorphous polycarbonate particles is shown in FIG. Moreover, it observed similarly about the acrylic resin particle used by the Example and the comparative example. A photomicrograph of the acrylic resin particles is shown in FIG.

(Evaluation of coating material storage stability of coating materials)
The coating materials obtained in Examples 1 to 21 and Comparative Examples 1 to 10 were put in a glass bottle and left at room temperature for 1 week. The state of the coating material after standing for 1 week was confirmed, and the coating material storage stability was evaluated according to the following criteria. In addition, about the coating material (11) obtained in Example 11, and the coating material (14) obtained in Example 14, the coating material before adding polyisocyanate was evaluated.
○: Hard cake does not occur.
Δ: Some hard cake is formed.
X: A hard cake is formed.

(Production of light diffusion sheet for evaluation: Examples 1 to 10, 12, 15 to 21 and Comparative Examples 1 to 10)
Using the coating material obtained in the above Examples 1 to 10, 12, 15 to 21 and Comparative Examples 1 to 10 on a polyethylene terephthalate sheet (“Cosmo Shine” manufactured by Toyobo Co., Ltd., thickness 188 μm) using a bar coater It was applied and dried on a hot plate at 60 ° C. Next, using an ultraviolet irradiation device (a lamp manufactured by Eye Graphics Co., Ltd., lamp: metal halide lamp), ultraviolet rays were irradiated at an irradiation amount of 0.5 J / cm ² to cure the coating film of the applied coating material. The light-diffusion sheet which has a light-diffusion layer which consists of a cured coating film of the coating material obtained by 10, 12, 15-21 and Comparative Examples 1-10 was obtained.

(Production of light diffusing sheet for evaluation: Examples 11 and 14)
The polyisocyanate (Dainippon Ink & Chemicals, Inc.) was added to 292.5 parts by mass of the coating material (11) obtained in Example 11 or 351.5 parts by mass of the coating material (14) obtained in Example 14. (Burnock DN-950, non-volatile content: 75% by mass) 13.3 parts by mass were added, mixed and stirred, and diluted with ethyl acetate to obtain a thermosetting coating material having a non-volatile content of 30% by mass. Next, this coating material was applied to a polyethylene terephthalate sheet (“Cosmo Shine” manufactured by Toyobo Co., Ltd., thickness 188 μm) using a bar coater, and the solvent was removed and the resin was thermally cured on a hot plate at 100 ° C. Then, a light diffusion sheet having a light diffusion layer composed of a cured coating film of the coating material obtained in Example 11 or 14 was obtained. When the coating material (11) obtained in Example 11 and the coating material (14) obtained in Example 14 were used, the acrylic polyol and polyisocyanate were thermally cured to obtain an acrylic urethane resin. It becomes.

(Production of light diffusion sheet for evaluation: Example 13)
The coating material (13) obtained in Example 13 was applied to a polyethylene terephthalate sheet (“Cosmo Shine” manufactured by Toyobo Co., Ltd., thickness 188 μm) using a bar coater and dried on a hot plate at 60 ° C. And the light-diffusion sheet which has a light-diffusion layer which consists of a coating film of the coating material obtained in Example 13 was obtained.

(Confirmation of unevenness and unevenness of light diffusion sheet)
For the light diffusing sheet obtained above, the presence or absence of aggregates (spots) on the surface of the light diffusing layer and the presence or absence of a phenomenon (unevenness) in which the light diffusibility becomes partially non-uniform are confirmed visually. It was evaluated according to the criteria.
◯: There is no unevenness or unevenness.
Δ: Slightly uneven or uneven.
X: There are bumps or unevenness.

(Evaluation of scratch resistance of light diffusion sheet)
The surface of the light diffusing sheet obtained above was rubbed by hand with a paper wiper ("Kimwipe S-200" manufactured by Crecia Co., Ltd.), and then the surface of the light diffusing sheet was visually confirmed, and the following criteria were used. Was used to evaluate the scratch resistance.
○: The light diffusion layer does not peel off.
X: The light diffusion layer is peeled off.

(Measurement of haze value of light diffusion sheet)
About the light-diffusion sheet obtained above, using a haze meter (“NDH-2000” manufactured by Nippon Denshoku Industries Co., Ltd.), light is incident from the opposite surface of the light-diffusion layer of the light-diffusion sheet and the haze value is measured. did. Note that the higher the haze value, the higher the light diffusivity.

(Measurement of light transmittance of light diffusion sheet)
About the light-diffusion sheet obtained above, using a haze meter ("NDH-2000" manufactured by Nippon Denshoku Industries Co., Ltd.), light is incident from the opposite surface of the light-diffusion layer of the light-diffusion sheet, and the total light transmittance is obtained. Was measured.

  The above evaluation results are shown in Tables 1-6.

  The coating material for light diffusion sheet of the present invention of Examples 1 to 21 is excellent in coating material storage stability without producing a hard cake over time, and the light diffusion sheet using the coating material for light diffusion sheet of the present invention is It was found that even a small amount of the light diffusing agent has high light diffusibility, no unevenness and unevenness, and good scratch resistance.

  On the other hand, in the comparative example, as the light diffusing agent, acrylic resin particles, acrylic urethane resin particles, styrene resin particles, wax, and silica beads were used alone (Comparative Examples 1 to 4 and 6), only the acrylic resin particles. And the examples in which the blending amount was increased (Comparative Examples 5 and 7), and the examples (Comparative Examples 8 to 10) in which acrylic resin particles were used as the main component and were used in combination with styrene resin particles, wax or silica beads. Went. The evaluation results of each comparative example were as follows.

  Comparative Example 1 is an example of a coating material using only acrylic resin particles as a light diffusing agent. This coating material produced a hard cake over time and had a problem in coating material storage stability. Also, compared with Examples 3, 8, and 9 containing the same amount of light diffusing agent, the haze value is significantly low and the light diffusibility is insufficient, and slight unevenness and unevenness occur in the light diffusing layer. I found out that

  Comparative Example 2 is an example of a coating material using only styrene resin particles as a light diffusing agent. This coating material produced a little hard cake over time, and had a slight problem in coating material storage stability. Moreover, compared with Example 3, 8, and 9 which mix | blended the same amount of light-diffusion agents, a haze value is low and light-diffusion property is inadequate, and a slight lump and nonuniformity generate | occur | produce in a light-diffusion layer. I understood.

  Comparative Example 3 is an example of a coating material using only a wax as the light diffusing agent. This coating material had good coating material storage stability, but had a low haze value and insufficient light diffusibility compared to Examples 3, 8 and 9 containing the same amount of light diffusing agent. It was. In addition, it was found that the light diffusion layer was uneven and uneven, and the light diffusion layer had insufficient scratch resistance.

  Comparative Example 4 is an example of a coating material using only silica beads as a light diffusing agent. This coating material produced some hard cake over time, and had a problem in coating material storage stability. Moreover, it turned out that a haze value is low compared with Example 3, 8 and 9 which mix | blended the same quantity of light-diffusion agents, and a lump and a nonuniformity generate | occur | produce in a light-diffusion layer.

  Comparative Examples 5 and 7 are examples in which the blending amount of the acrylic resin particles of the light diffusing agent was increased as compared with Comparative Example 1. These coating materials produced a hard cake over time and had a problem in coating material storage stability. Further, it was found that the haze value was not improved despite the increase in the blending amount of the acrylic resin particles, and irregularities or irregularities were generated in the light diffusion layer.

  Comparative Example 6 is an example of a coating material using only acrylic urethane resin particles as a light diffusing agent. With this coating material, a hard cake was formed over time, and there was a problem in coating material storage stability. It was also found that unevenness occurred in the light diffusion layer.

  Comparative Example 8 is an example of a coating material in which acrylic resin particles and styrene resin particles are used in combination with a light diffusing agent. This coating material produced a hard cake over time and had a problem in coating material storage stability. Moreover, it turned out that a haze value is low compared with Example 10 which mix | blended the same amount of light-diffusion agents as a total.

  Comparative Example 9 is an example of a coating material in which acrylic resin particles and wax are used in combination with a light diffusing agent. This coating material had good coating material storage stability, but the haze value was low compared to Example 10 in which the same amount of light diffusing agent was blended, and the scratch resistance was insufficient. I understood.

  Comparative Example 10 is an example of a coating material in which acrylic resin particles and silica beads are used in combination with a light diffusing agent. This coating material produced a hard cake over time and had a problem in coating material storage stability. Moreover, it turned out that a haze value is low compared with Example 10 which mix | blended the same amount of light-diffusion agents as a total, and a light diffusive layer produces bumps.

It is a microscope picture of the amorphous polycarbonate resin particle used in the Example. It is a microscope picture of the acrylic resin particle used by the Example and the comparative example.

Claims (9)

A coating material for a light diffusion sheet, comprising a binder resin (A) and an amorphous polycarbonate resin particle (B). The coating material for a light diffusing sheet according to claim 1, wherein the sphericity of the amorphous polycarbonate resin particles (B) is 0.50 to 0.94. The coating material for a light diffusion sheet according to claim 1 or 2, wherein the irregular polycarbonate resin particles (B) have an average particle size of 0.1 to 20 µm. The coating material for a light diffusing sheet according to any one of claims 1 to 3, wherein the amount of the amorphous polycarbonate resin particle (B) is 1 to 100 parts by mass with respect to 100 parts by mass of the binder resin (A). A coating material for a light diffusion sheet, comprising a binder resin (A), an amorphous polycarbonate resin particle (B), and an acrylic resin particle (C). The light according to claim 5, wherein the sphericity of the amorphous polycarbonate resin particles (B) is 0.50 to 0.94, and the sphericity of the acrylic resin particles (C) is 0.95 or more. Coating material for diffusion sheet. The light diffusion according to claim 5 or 6, wherein the irregular polycarbonate resin particles (B) have an average particle size of 0.1 to 20 µm, and the acrylic resin particles (C) have an average particle size of 1 to 30 µm. Sheet coating material. The total blending amount of the amorphous polycarbonate resin particles (B) and the acrylic resin particles (C) with respect to 100 parts by mass of the binder resin (A) is 5 to 80 parts by mass. The coating material for a light diffusion sheet according to Item. A light diffusion sheet comprising a light diffusion layer comprising a coating film of the coating material for a light diffusion sheet according to claim 1.