WO2013111674A1 - Photosensitive composition, pattern, and display device having pattern - Google Patents

Abstract

Provided are: a photosensitive composition for forming a pattern that is used in a display device and has a light scattering function; a pattern; and a display device which has a pattern. This photosensitive composition for forming a pattern that is used in a display device and has a light scattering function contains a TiO₂ filler, a photopolymerizable (meth)acrylic monomer, an alkali-soluble resin, a photopolymerization initiator and an organic solvent. The ratio of the TiO₂ filler in the total mass of the TiO₂ filler, the photopolymerizable (meth)acrylic monomer and the alkali-soluble resin is within the range of 10-35% by mass.

Description

Photosensitive composition, pattern and display device having pattern

The present invention relates to a photosensitive composition for forming a pattern having a light scattering function for use in a display device, a pattern and a display device having the pattern.

Conventionally, a full-color display device using a white light backlight instead of a self-luminous type is mainly composed of the backlight and an optical shutter. For example, a liquid crystal display device includes a light source such as an LED or a cold cathode tube, a light guide plate, and an optical sheet as a backlight, and a liquid crystal panel as an optical shutter. The liquid crystal panel includes two polarizing plates, a pair of substrates, and a liquid crystal layer sealed between the substrates. The pair of substrates has a TFT pattern and red, green, blue (R, G, B), respectively. ) Color filter (CF). However, the white light emitted from the light source is transmitted only about 1/3 because light other than the color is absorbed by the color filter. That is, in the above configuration, the utilization efficiency of white light is low.

Therefore, in order to improve the light utilization efficiency, a blue light backlight is used, a liquid crystal panel, a red phosphor that absorbs blue light and emits red light, and blue light that absorbs green light. A liquid crystal display device including a green phosphor that emits light has been proposed (Patent Documents 1 and 2). In the above configuration, the amount of light absorbed by the color filter is reduced, so that the light use efficiency is improved. In addition, by forming a reflective layer on the side surface of the phosphor, the light emitted in the lateral direction (direction parallel to the transparent substrate) is reflected and emitted from the transparent substrate, thereby improving the light utilization efficiency. An apparatus has also been proposed (Patent Document 5).

However, in each of the above configurations, the alignment characteristics of red light emitted from the red phosphor and green light emitted from the green phosphor exhibit Lambertian (light intensity distribution), whereas blue light is phosphor. Therefore, the blue light does not show Lambertian in the alignment characteristics. That is, the alignment characteristics of blue light are different from the alignment characteristics of red light and green light. Therefore, the display quality is deteriorated by increasing the chromaticity change in the oblique direction with respect to the front direction in the liquid crystal display device.

Therefore, a liquid crystal display device has been proposed in which blue light is transmitted through a scattering layer having a light scattering function, thereby reducing a change in chromaticity in an oblique direction with respect to the front direction in the liquid crystal display device, thereby improving display quality. (Patent Documents 3 and 4).

In recent years, various compositions for forming the scattering layer have been studied. For example, Patent Document 6 discloses a carboxylic acid compound, a copolymer of an epoxy group-containing unsaturated compound and an olefinic-containing unsaturated compound, A radiation-sensitive composition containing a light-scattering substance, a polyfunctional monomer, and a photopolymerization initiator has been proposed.

Japanese Patent Publication “JP 2000-131683 (May 12, 2000)” Japanese Patent Publication “JP 2003-5182 (published Jan. 8, 2003)” Japanese Published Patent Publication “JP 2009-115925 (May 28, 2009)” Japanese Patent Publication “JP 2009-244383 (released on Oct. 22, 2009)” Japanese Patent Publication “JP 2010-66437 (published on March 25, 2010)” Japanese Patent Publication “JP 2001-316408 (published Nov. 13, 2001)”

However, the radiation-sensitive composition described in Patent Document 6 is intended to efficiently scatter reflected light and realize surface illumination with high front luminance (described in paragraph [0006] and the like). No particular consideration is given to preventing chromaticity change (color shift) between the front direction and the oblique direction in the display device. That is, in the radiation-sensitive composition described in Patent Document 6, no special consideration is given to the light scattering function that scatters blue light emitted from a light source at a wide angle.

Also, a conventional light scattering film containing an acrylic filler or the like used for a display device has a narrow scattering angle width of about 10 to 30 degrees of light transmitted through the light scattering film. For this reason, the conventional light scattering film has a problem that blue light cannot be scattered at a wide angle.

In order to prevent chromaticity change (color shift) between the front direction (normal direction with respect to the light emitting surface) and the oblique direction in the display device, the alignment characteristics of blue light should also be Lambertian (light intensity distribution). Need to show. Moreover, in order to produce a pattern efficiently, the composition which forms a diffused layer needs to have a photolithography characteristic. That is, the pattern (scattering layer) formed using the photosensitive composition needs to have a light scattering function of scattering blue light emitted from the light source at a wide angle. Therefore, in order to improve display quality, a photosensitive composition having a photolithography characteristic suitable for use in a display device and having a light scattering characteristic for scattering blue light at a wide angle, that is, the above-mentioned There is a need for a photosensitive composition for forming a pattern having an excellent light scattering function.

The present invention has been made in view of the above problems, and a main object thereof is to provide a photosensitive composition for forming a pattern having a light scattering function used in a display device. Another object is to provide a pattern having a light scattering function formed by using the photosensitive composition, and a display device having the pattern.

The photosensitive composition according to the present invention is a photosensitive composition for forming a pattern having a light scattering function used in a display device in order to solve the above-described problem, and includes a TiO ₂ filler, a photopolymerizable ( meth) acrylic monomer, an alkali-soluble resin, a photopolymerization initiator, and comprises an organic solvent, the TiO ₂ filler, the proportion of the photopolymerizable (meth) TiO ₂ filler to the total weight of the acrylic monomer and the alkali-soluble resin, 10 It is characterized by being in the range of ~ 35% by mass.

According to the above configuration, since the TiO ₂ filler is dispersed in the photopolymerizable (meth) acrylic monomer and the alkali-soluble resin, that is, in the negative photosensitive resin, the photolithography characteristics and the light scattering characteristics are compatible. A photosensitive composition can be obtained. That is, it is possible to provide a photosensitive composition suitable for use in a display device, having a photolithography characteristic and having a light scattering characteristic that scatters blue light at a wider angle than an incident angle by a TiO ₂ filler. it can.

Further, the pattern according to the present invention is formed using the photosensitive composition in order to solve the above-described problems. Furthermore, the display device according to the present invention has the above pattern in order to solve the above-described problems.

According to the above configuration, since the alignment characteristic of blue light shows Lambertian (light intensity distribution), chromaticity change (color shift) does not occur between the front direction and the diagonal direction, and the display quality is improved. An apparatus can be provided.

According to the photosensitive composition of the present invention, it has a photolithography characteristic suitable for use in a display device, and has a light scattering characteristic that scatters blue light at a wider angle than an incident angle by a TiO ₂ filler. There exists an effect that the photosensitive composition which has can be provided. Further, according to the pattern according to the present invention and the display device according to the present invention, since the alignment characteristic of blue light indicates Lambertian (light intensity distribution), chromaticity change (color shift) between the front direction and the oblique direction. This produces an effect that a display device with improved display quality can be provided.

FIG. 1 is a block diagram illustrating a schematic configuration of an example of a display device according to the present invention. It is a block diagram which shows another example of the display apparatus which concerns on this invention, and shows a schematic structure. An example of the principal part of the said display apparatus is shown, and it is sectional drawing which shows a schematic structure. FIG. 2 is a cross-sectional view illustrating an example of a color conversion substrate included in the display device and illustrating a schematic configuration. It is sectional drawing which shows another example of the color conversion board | substrate with which the said display apparatus is provided, and shows a schematic structure. It is sectional drawing which shows another example of the color conversion board | substrate with which the said display apparatus is provided, and shows a schematic structure. It is the graph which showed the light intensity distribution which the pattern in Example 1 of this invention shows with the relative value when the light intensity of the front direction in a display apparatus is set to "1". It is the graph which showed the light intensity distribution which the pattern in the comparative example 1 shows by the relative value when the light intensity of the front direction in a display apparatus is set to "1". An example of the principal part of the said display apparatus is shown, (a) which shows schematic structure is sectional drawing, (b) is the top view seen from the visual recognition side. The other example of the principal part of the said display apparatus is shown, (a) which shows schematic structure is sectional drawing, (b) is the top view seen from the visual recognition side.

An embodiment of the present invention will be described in detail below in the order of a photosensitive composition, a pattern, and a display device.

[Photosensitive composition]
The photosensitive composition according to the present invention includes a TiO ₂ filler, a photopolymerizable (meth) acrylic monomer, an alkali-soluble resin, a photopolymerization initiator, and an organic solvent, and the TiO ₂ filler, the photopolymerizable (meth) acrylic. The proportion of the TiO ₂ filler in the total amount of monomer and alkali-soluble resin is in the range of 10 to 35% by mass. Each configuration will be described below.

<TiO ₂ filler>
The TiO ₂ filler may be any particle size or shape that can exhibit a light scattering function for scattering blue light. Therefore, the particle size or shape is not particularly limited, but specifically, the average particle size is 100 It is more preferably in the range of ˜1,000 nm, and further preferably in the range of 150 to 250 nm. If the average particle size is less than 100 nm, it may be difficult to exhibit the light scattering function. If the average particle diameter exceeds 1,000 nm, blue light may hardly pass through the pattern.

The proportion of the TiO ₂ filler in the total amount of the TiO ₂ filler, the photopolymerizable (meth) acrylic monomer and the alkali-soluble resin is preferably in the range of 10 to 35% by mass, and 20 to 30% by mass. More preferably within the range. When the proportion of the TiO ₂ filler is less than 10% by mass, it becomes difficult to exhibit the light scattering function. If the proportion of the TiO ₂ filler exceeds 35% by mass, it is difficult for blue light to pass through the pattern.

<Photopolymerizable (meth) acrylic monomer>
The photopolymerizable (meth) acrylic monomer has an acryloyl group (—CH═CH—CO—) or a methacryloyl group (—CH═C (CH ₃ ) —CO—), which is a functional group containing an ethylenically unsaturated group, as a molecule. Any (meth) acrylic monomer that can be photopolymerized can be used. A photopolymerizable (meth) acryl monomer constitutes a negative photosensitive resin together with an alkali-soluble resin.

Specifically, the photopolymerizable (meth) acrylic monomer may be at least one selected from monofunctional (meth) acrylic monomers and polyfunctional (meth) acrylic monomers. That is, the photopolymerizable (meth) acrylic monomer may be composed of a monofunctional (meth) acrylic monomer, may be composed of a polyfunctional (meth) acrylic monomer, or may be composed of a monofunctional (meth) acrylic monomer. It may consist of a mixture of monomers and polyfunctional (meth) acrylic monomers.

Specific examples of the monofunctional (meth) acrylic monomer include (meth) acrylamide, methylol (meth) acrylamide, methoxymethyl (meth) acrylamide, ethoxymethyl (meth) acrylamide, and propoxymethyl (meth) acrylamide. , Butoxymethoxymethyl (meth) acrylamide, N-methylol (meth) acrylamide, N-hydroxymethyl (meth) acrylamide, (meth) acrylic acid, fumaric acid, maleic acid, maleic anhydride, itaconic acid, itaconic anhydride, citracone Acid, citraconic anhydride, crotonic acid, 2-acrylamido-2-methylpropanesulfonic acid, t-butylacrylamidesulfonic acid, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate 2-ethylhexyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 2-phenoxy-2-hydroxypropyl (Meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, 2- (meth) acryloyloxy-2-hydroxypropyl phthalate, 2- (meth) acryloyloxyethyl-2-hydroxypropyl phthalate, glycerin mono ( (Meth) acrylate, tetrahydrofurfuryl (meth) acrylate, dimethylamino (meth) acrylate, glycidyl (meth) acrylate, 2,2,2-trifluoroethyl (meth) acrylate, , 2,3,3-tetrafluoro propyl (meth) acrylate, a half (meth) acrylate of phthalic acid derivatives. These monofunctional (meth) acrylic monomers may be used alone or in combination of two or more.

Specific examples of the polyfunctional (meth) acrylic monomer include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, and propylene glycol di (meth) acrylate. , Polypropylene glycol di (meth) acrylate, butylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, 1,6-hexane glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, glycerin di ( (Meth) acrylate, pentaerythritol di (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaeryth Tall penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 2,2-bis (4- (meth) acryloxydiethoxyphenyl) propane, 2,2-bis (4- (meth) acryloxy polyethoxy Phenyl) propane, 2-hydroxy-3- (meth) acryloyloxypropyl (meth) acrylate, ethylene glycol diglycidyl ether di (meth) acrylate, diethylene glycol diglycidyl ether di (meth) acrylate, diglycidyl phthalate di (meth) ) Acrylate, glycerin triacrylate, glycerin polyglycidyl ether poly (meth) acrylate, urethane (meth) acrylate (ie, tolylene diisocyanate), trimethylhexamethylene diisocyanate , Hexamethylene diisocyanate and 2-hydroxyethyl (meth) acrylate, methylenebis (meth) acrylamide, (meth) acrylamide methylene ether, condensate of polyhydric alcohol and N-methylol (meth) acrylamide, bisphenol A di Examples include (meth) acrylic acid adducts of glycidyl ether. Moreover, triacryl formal can also be used as a polyfunctional (meth) acryl monomer. These polyfunctional (meth) acrylic monomers may be used alone or in combination of two or more.

Among the photopolymerizable (meth) acrylic monomers exemplified above, 2- (meth) acryloyloxyethyl-2-hydroxypropyl phthalate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, and (meta) of bisphenol A diglycidyl ether ) Acrylic acid adduct is more preferable, and methacrylic acid adduct of 2-methacryloyloxyethyl-2-hydroxypropyl phthalate, 2-hydroxy-3-phenoxypropyl acrylate and bisphenol A diglycidyl ether is more preferable.

<Alkali-soluble resin>
The alkali-soluble resin may be any resin that is soluble in an alkaline aqueous solution, and therefore the structure is not particularly limited. Specifically, the acid value, which is an index of resin solubility, is in the range of 50 to 250 mgKOH / g. More preferably. If the acid value of the alkali-soluble resin is less than 50 mgKOH / g, it may be difficult to dissolve in the alkaline aqueous solution. If the acid value of the alkali-soluble resin exceeds 250 mgKOH / g, the alkali resistance may be lowered. The alkali-soluble resin may have an acryloyl group or a methacryloyl group in the molecule.

Examples of the monomer constituting the alkali-soluble resin include unsaturated carboxylic acids, acrylic esters, methacrylic esters, acrylamides, methacrylamides, allyl compounds, vinyl ethers, vinyl esters, styrenes, and the like. It is done. That is, the alkali-soluble resin is a polymer or copolymer obtained by polymerizing at least one of these monomers.

Specific examples of the unsaturated carboxylic acids include monocarboxylic acids such as acrylic acid, methacrylic acid, and crotonic acid; dicarboxylic acids such as maleic acid, fumaric acid, citraconic acid, mesaconic acid, and itaconic acid; and The anhydride of these dicarboxylic acids etc. are mentioned.

Specific examples of the acrylic esters include, for example, methyl acrylate, ethyl acrylate, propyl acrylate, isopropyl acrylate, butyl acrylate, amyl acrylate, ethyl hexyl acrylate, octyl acrylate, acrylic acid- linear or branched alkyl acrylates such as t-octyl; fats such as cyclohexyl acrylate, dicyclopentanyl acrylate, 2-methylcyclohexyl acrylate, dicyclopentanyl acrylate, dicyclopentaoxyethyl acrylate, isobornyl acrylate, etc. Cyclic alkyl acrylate; chloroethyl acrylate, 2,2-dimethylhydroxypropyl acrylate, 2-hydroxyethyl acrylate, 5-hydroxypentyl acrylate, trimethyl Lumpur propane monoacrylate, pentaerythritol monoacrylate, benzyl acrylate, methoxybenzyl acrylate, furfuryl acrylate, tetrahydrofurfuryl acrylate, and aryl acrylates (e.g., phenyl acrylate, and the like) and the like.

Specific examples of the methacrylic acid esters include methyl methacrylate, ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, sec-butyl methacrylate, t-butyl methacrylate, amyl methacrylate, and hexyl methacrylate. Linear or branched alkyl methacrylates such as octyl methacrylate; alicyclic alkyl methacrylates such as cyclohexyl methacrylate, dicyclopentanyl methacrylate, 2-methylcyclohexyl methacrylate, dicyclopentanyloxyethyl methacrylate, isobornyl methacrylate; glycidyl Epoxy group-containing methacrylates such as methacrylate; 2-hydroxyethyl methacrylate Cyclates, 4-hydroxybutyl methacrylate, 5-hydroxypentyl methacrylate, 2,2-dimethyl-3-hydroxypropyl methacrylate, trimethylolpropane monomethacrylate, pentaerythritol monomethacrylate; cyclic ether groups such as furfuryl methacrylate and tetrahydrofurfuryl methacrylate Included methacrylates; aryl methacrylates such as benzyl methacrylate, chlorobenzyl methacrylate, phenyl methacrylate, cresyl methacrylate, naphthyl methacrylate;

Specific examples of the acrylamides include, for example, acrylamide, N-alkylacrylamide (the alkyl group preferably has 1 to 10 carbon atoms, such as methyl group, ethyl group, propyl group, butyl group, t-butyl group). Group, heptyl group, octyl group, cyclohexyl group, hydroxyethyl group, benzyl group, etc.), N-arylacrylamide (examples of aryl group include phenyl group, tolyl group, nitrophenyl group, naphthyl group, hydroxyphenyl group) N, N-dialkylacrylamide (the alkyl group preferably has 1 to 10 carbon atoms), N, N-arylacrylamide (the aryl group includes, for example, a phenyl group), N -Methyl-N-phenylacrylamide, N-hydroxy ester Le -N- methylacrylamide, N-2-acetamidoethyl -N- acetyl acrylamide.

Specific examples of the methacrylamides include, for example, methacrylamide, N-alkylmethacrylamide (the alkyl group preferably has 1 to 10 carbon atoms, such as a methyl group, an ethyl group, a t-butyl group, an ethylhexyl group). Group, hydroxyethyl group, cyclohexyl group and the like), N-aryl methacrylamide (the aryl group includes, for example, phenyl group), N, N-dialkylmethacrylamide (the alkyl group includes, for example, ethyl group) , A propyl group, a butyl group, etc.), N, N-diarylmethacrylamide (an aryl group includes, for example, a phenyl group), N-hydroxyethyl-N-methylmethacrylamide, N-methyl-N -Phenylmethacrylamide, N-ethyl-N-phenylmeta Riruamido, and the like.

Specific examples of the allyl compound include allyl esters (for example, allyl acetate, allyl caproate, allyl caprylate, allyl laurate, allyl palmitate, allyl stearate, allyl benzoate, allyl acetoacetate, lactic acid). Allyl and the like), and allyloxyethanol and the like.

Specific examples of the vinyl ethers include alkyl vinyl ethers (for example, hexyl vinyl ether, octyl vinyl ether, decyl vinyl ether, ethylhexyl vinyl ether, methoxyethyl vinyl ether, ethoxyethyl vinyl ether, chloroethyl vinyl ether, 1-methyl-2,2-dimethyl). Propyl vinyl ether, 2-ethylbutyl vinyl ether, hydroxyethyl vinyl ether, diethylene glycol vinyl ether, dimethylaminoethyl vinyl ether, diethylaminoethyl vinyl ether, butylaminoethyl vinyl ether, benzyl vinyl ether, tetrahydrofurfuryl vinyl ether, etc.), vinyl aryl ether (for example, vinyl phenyl) Ether, vinyl Rirueteru, vinyl chlorophenyl ether, vinyl 2,4-dichlorophenyl ether, vinyl naphthyl ether and vinyl anthranyl ether and the like) and the like.

Specific examples of the vinyl esters include, for example, vinyl butyrate, vinyl isobutyrate, vinyl trimethyl acetate, vinyl diethyl acetate, vinyl Valate, vinyl caproate, vinyl chloroacetate, vinyl dichloroacetate, vinyl methoxy. Examples include acetate, vinyl butoxyacetate, vinylphenyl acetate, vinyl acetoacetate, vinyl lactate, vinyl-β-phenylbutyrate, vinyl benzoate, vinyl salicylate, vinyl chlorobenzoate, vinyl tetrachlorobenzoate, vinyl naphthoate and the like.

Specific examples of the styrenes include styrene and alkyl styrene (for example, methyl styrene, dimethyl styrene, trimethyl styrene, ethyl styrene, diethyl styrene, isopropyl styrene, butyl styrene, hexyl styrene, cyclohexyl styrene, decyl styrene, benzyl). Styrene, chloromethyl styrene, trifluoromethyl styrene, ethoxymethyl styrene, acetoxymethyl styrene, etc.), alkoxy styrene (for example, methoxy styrene, 4-methoxy-3-methyl styrene, dimethoxy styrene, etc.), halogen styrene (For example, chlorostyrene, dichlorostyrene, trichlorostyrene, tetrachlorostyrene, pentachlorostyrene, bromostyrene, dibromostyrene Iodostyrene, fluorostyrene, trifluorostyrene, 2-bromo-4-trifluoromethyl styrene, 4-fluoro-3-trifluoromethyl styrene, and the like) and the like.

These monomers constituting the alkali-soluble resin may be used alone or in combination of two or more.

Among the monomers exemplified above, methacrylic acid, methyl methacrylate, isobutyl methacrylate, glycidyl methacrylate, and benzyl methacrylate are more preferable, a combination of methacrylic acid, glycidyl methacrylate, and benzyl methacrylate, and a combination of methacrylic acid, methyl methacrylate, and isobutyl methacrylate. Is more preferable. That is, the alkali-soluble resin is more preferably a polymer or copolymer obtained by polymerizing these monomers.

If the acid value is in the range of 50 to 250 mgKOH / g, the alkali-soluble resin is a copolymer obtained by copolymerizing a monomer composition containing at least one of the above-exemplified monomers and another monomer. It may be a polymer.

The production method of the alkali-soluble resin, that is, the polymerization method of the monomer is not particularly limited, and a conventionally known polymerization method can be employed. The weight average molecular weight (Mw) of the alkali-soluble resin is not particularly limited, but is more preferably in the range of 5,000 to 80,000.

<Photopolymerization initiator>
If a photoinitiator is an initiator which can photopolymerize the said photopolymerizable (meth) acryl monomer and alkali-soluble resin (however, when it has an acryloyl group or a methacryloyl group in a molecule | numerator). Well known photopolymerization initiators can be used and are not particularly limited.

Specific examples of the photopolymerization initiator include 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, and 1- [4- (2-hydroxyethoxy). Phenyl] -2-hydroxy-2-methyl-1-propan-1-one, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, 1- (4-dodecylphenyl)- 2-hydroxy-2-methylpropan-1-one, 2,2-dimethoxy-1,2-diphenylethane-1-one, bis (4-dimethylaminophenyl) ketone, 2-methyl-1- [4- ( Methylthio) phenyl] -2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butane- -One, ethanone, 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl], 1- (o-acetyloxime), 2,4,6-trimethylbenzoyldiphenylphosphine oxide 4-benzoyl-4′-methyldimethylsulfide, 4-dimethylaminobenzoic acid, methyl 4-dimethylaminobenzoate, ethyl 4-dimethylaminobenzoate, butyl 4-dimethylaminobenzoate, 4-dimethylamino-2- Ethylhexylbenzoic acid, 4-dimethylamino-2-isoamylbenzoic acid, benzyl-β-methoxyethyl acetal, benzyldimethyl ketal, 1-phenyl-1,2-propanedione-2- (o-ethoxycarbonyl) oxime, o- Methyl benzoylbenzoate, 2,4-diethylthioxanthone, 2 -Chlorothioxanthone, 2,4-dimethylthioxanthone, 1-chloro-4-propoxythioxanthone, thioxanthene, 2-chlorothioxanthene, 2,4-diethylthioxanthene, 2-methylthioxanthene, 2-isopropylthioxanthene, 2- Ethyl anthraquinone, octamethylanthraquinone, 1,2-benzanthraquinone, 2,3-diphenylanthraquinone, azobisisobutyronitrile, benzoyl peroxide, cumene peroxide, 2-mercaptobenzoimidar, 2-mercaptobenzoxazole, 2 -Mercaptobenzothiazole, 2- (o-chlorophenyl) -4,5-diphenylimidazole dimer, 2- (o-chlorophenyl) -4,5-di (methoxyphenyl) imidazole dimer, 2- o-fluorophenyl) -4,5-diphenylimidazole dimer, 2- (o-methoxyphenyl) -4,5-diphenylimidazole dimer, 2- (p-methoxyphenyl) -4,5-diphenylimidazole Dimer, 2,4,5-triarylimidazole dimer, benzophenone, 2-chlorobenzophenone, 4,4′-bisdimethylaminobenzophenone (ie, Michler's ketone), 4,4′-bisdiethylaminobenzophenone (ie, Ethyl Michler's ketone), 4,4'-dichlorobenzophenone, 3,3-dimethyl-4-methoxybenzophenone, benzyl, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin-n-butyl ether, benzoin isobu Ether, benzoin-t-butyl ether, acetophenone, 2,2-diethoxyacetophenone, p-dimethylacetophenone, p-dimethylaminopropiophenone, dichloroacetophenone, trichloroacetophenone, pt-butylacetophenone, p-dimethylaminoacetophenone, pt-butyltrichloroacetophenone, pt-butyldichloroacetophenone, α, α-dichloro-4-phenoxyacetophenone, thioxanthone, 2-methylthioxanthone, 2-isopropylthioxanthone, dibenzosuberone, pentyl-4-dimethylaminobenzoate 9-phenylacridine, 1,7-bis- (9-acridinyl) heptane, 1,5-bis- (9-acridinyl) pentane, 1,3-bis- (9-a Lysinyl) propane, p-methoxytriazine, 2,4,6-tris (trichloromethyl) -s-triazine, 2-methyl-4,6-bis (trichloromethyl) -s-triazine, 2- [2- (5 -Methylfuran-2-yl) ethenyl] -4,6-bis (trichloromethyl) -s-triazine, 2- [2- (furan-2-yl) ethenyl] -4,6-bis (trichloromethyl)- s-triazine, 2- [2- (4-diethylamino-2-methylphenyl) ethenyl] -4,6-bis (trichloromethyl) -s-triazine, 2- [2- (3,4-dimethoxyphenyl) ethenyl ] -4,6-bis (trichloromethyl) -s-triazine, 2- (4-methoxyphenyl) -4,6-bis (trichloromethyl) -s-triazine, 2- (4-etho Xistyryl) -4,6-bis (trichloromethyl) -s-triazine, 2- (4-n-butoxyphenyl) -4,6-bis (trichloromethyl) -s-triazine, 2,4-bis-trichloromethyl -6- (3-bromo-4-methoxy) phenyl-s-triazine, 2,4-bis-trichloromethyl-6- (2-bromo-4-methoxy) phenyl-s-triazine, 2,4-bis- And trichloromethyl-6- (3-bromo-4-methoxy) styrylphenyl-s-triazine, 2,4-bis-trichloromethyl-6- (2-bromo-4-methoxy) styrylphenyl-s-triazine, etc. It is done. As the photopolymerization initiator, commercially available products “IRGACURE OXE02”, “IRGACURE OXE01”, “IRGACURE 369”, “IRGACURE 651”, “IRGACURE 907” (trade names: all manufactured by BASF), “NCI- 831 "(trade name: manufactured by ADEKA) or the like can also be used.

Among the photopolymerization initiators exemplified above, for example, the photopolymerizable (meth) acrylic monomer is 2- (meth) acryloyloxyethyl-2-hydroxypropyl phthalate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, bisphenol. In the case of a (meth) acrylic acid adduct of A diglycidyl ether, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one is more preferred.

The addition amount of the photopolymerization initiator can be set according to the type and ratio of the photopolymerizable (meth) acrylic monomer and the alkali-soluble resin (provided that the acryloyl group or methacryloyl group is contained in the molecule). Well, although not particularly limited, it is within the range of 0.5 to 10% by mass with respect to the total amount (100% by mass) of the TiO ₂ filler, the photopolymerizable (meth) acrylic monomer and the alkali-soluble resin. More preferred.

<Organic solvent>
The organic solvent only needs to be a solvent that can uniformly dissolve the photopolymerizable (meth) acrylic monomer and the alkali-soluble resin at a necessary concentration, and conventionally known organic solvents can be used and are particularly limited. It is not a thing.

Examples of the organic solvent include saturated aliphatic hydrocarbons, aromatic hydrocarbons, terpene solvents, lactones, ketones, polyhydric alcohols, cyclic ethers, esters, ethylene glycol monoacetate, diethylene glycol monoester. Compounds having an ester bond such as acetate, propylene glycol monoacetate, dipropylene glycol monoacetate; monohydric compounds such as monomethyl ether, monoethyl ether, monopropyl ether, monobutyl ether of the above polyhydric alcohols or compounds having an ester bond Derivatives of polyhydric alcohols such as compounds having an ether bond such as alkyl ether or monophenyl ether; Of the polyhydric alcohol derivatives, diethylene glycol monobutyl ether, propylene glycol monomethyl ether (PGME), propylene glycol monomethyl ether acetate (PGMEA), and propylene glycol monoethyl ether acetate are more preferable.

Examples of the saturated aliphatic hydrocarbon include linear, branched or cyclic hydrocarbons, and specifically, for example, hexane, heptane, octane, nonane, methyloctane, decane, undecane, dodecane, tridecane, etc. Linear hydrocarbons, branched hydrocarbons having 3 to 15 carbon atoms; cyclohexane, cycloheptane, cyclooctane, decahydronaphthalene, p-menthane, o-menthane, m-menthane, diphenylmenthane, α-terpinene , Β-terpinene, γ-terpinene, 1,4-terpine, 1,8-terpine, bornane, norbornane, pinane, α-pinene, β-pinene, tujang, α-tujon, β-tujon, caran, longifolene, etc. Cyclic hydrocarbons; and the like.

Specific examples of the aromatic hydrocarbon include anisole, ethyl benzyl ether, cresyl methyl ether, diphenyl ether, dibenzyl ether, phenetole, and butyl phenyl ether. Moreover, condensed polycyclic hydrocarbon can also be used as an aromatic hydrocarbon. A condensed polycyclic hydrocarbon is a condensed ring hydrocarbon formed by two or more monocycles supplying only one side of each ring to each other, and is a hydrocarbon obtained by condensing two monocycles. It is preferable to use it. Examples of such hydrocarbons include a combination of a 5-membered ring and a 6-membered ring, or a combination of two 6-membered rings. Examples of hydrocarbons combining 5-membered rings and 6-membered rings include indene, pentalene, indane, tetrahydroindene, etc. Examples of hydrocarbons combining two 6-membered rings include naphthalene, tetrahydronaphthalene. (Tetralin) and decahydronaphthalene (decalin).

The terpene solvent has an oxygen atom, a carbonyl group or an acetoxy group as a polar group. Specific examples of the terpene solvent include geraniol, nerol, linalool, citral, citronellol, menthol, isomenthol, neomenthol, α-terpineol, β-terpineol, γ-terpineol, terpinene-1-ol, terpinene. Examples include -4-ol, dihydroterpinyl acetate, 1,4-cineole, 1,8-cineole, borneol, carvone, yonon, tuyon, camphor and the like.

Specific examples of the lactones include γ-butyrolactone.

Specific examples of the ketones include acetone, methyl ethyl ketone, cyclohexanone, methyl-n-pentyl ketone, methyl isopentyl ketone, and 2-heptanone.

Specific examples of the polyhydric alcohols include ethylene glycol, diethylene glycol, propylene glycol, and dipropylene glycol.

Specific examples of the cyclic ethers include dioxane.

Specific examples of the esters include methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, and ethyl ethoxypropionate.

These organic solvents may be used alone or in combination of two or more as a mixed solvent.

Among the organic solvents exemplified above, for example, the photopolymerizable (meth) acrylic monomer is 2- (meth) acryloyloxyethyl-2-hydroxypropyl phthalate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, bisphenol A diester. In the case of a (meth) acrylic acid adduct of glycidyl ether, a derivative of a polyhydric alcohol is more preferable. Diethylene glycol monobutyl ether, propylene glycol monomethyl ether (PGME), propylene glycol monomethyl ether acetate (PGMEA), propylene glycol mono More preferred is ethyl ether acetate.

The amount of the organic solvent used may be set according to the type and ratio of the photopolymerizable (meth) acrylic monomer and the alkali-soluble resin, and is not particularly limited. However, the TiO ₂ filler, the photopolymerizable (meth) acrylic monomer and More preferably, it is in the range of 3 to 20% by mass with respect to the total amount (100% by mass) of the alkali-soluble resin.

<Method for producing photosensitive composition>
The TiO ₂ filler, photopolymerizable (meth) acrylic monomer, alkali-soluble resin, photopolymerization initiator, and organic solvent are mixed together, and the total of the TiO ₂ filler, photopolymerizable (meth) acrylic monomer, and alkali-soluble resin. The photosensitive composition according to the present invention can be obtained by adjusting the proportion of the TiO ₂ filler in the amount within the range of 10 to 35% by mass. Although the mixing order of the TiO ₂ filler, photopolymerizable (meth) acrylic monomer, alkali-soluble resin, photopolymerization initiator, and organic solvent is not particularly limited, the TiO ₂ filler, photopolymerizable to the organic solvent is easy to mix. More preferably, the (meth) acrylic monomer and the alkali-soluble resin are added and mixed. In addition, as a mixing method, for example, a TiO ₂ filler, a photopolymerizable (meth) acrylic monomer, an alkali-soluble resin, a photopolymerization initiator, and an organic solvent are put in a container and stirred, and then roughly mixed. A method of further mixing using a disperser such as a roll mill or a mixer can be mentioned, but there is no particular limitation as long as the method can uniformly mix and disperse the TiO ₂ filler uniformly.

Then, the pattern having the ratio and average particle diameter of the TiO ₂ filler, and by optimizing within the scope of the present invention the composition of the photopolymerizable (meth) acrylic monomer and an alkali-soluble resin, the light scattering properties of interest A photosensitive composition having photolithographic properties suitable for forming a film is obtained.

〔pattern〕
By polymerizing the photopolymerizable (meth) acrylic monomer and the alkali-soluble resin (provided that they have an acryloyl group or a methacryloyl group in the molecule) contained in the photosensitive composition, that is, photolithography characteristics For example, the above-mentioned photosensitive composition comprising the above is applied to a transparent substrate, dried, exposed and developed to form a film, whereby the pattern having the light scattering function according to the present invention can be efficiently formed.

The method for applying the photosensitive composition includes, for example, a method using an applicator, but may be any method that can be applied to a uniform thickness according to the viscosity of the photosensitive composition, and is not particularly limited. It is not something. Moreover, what is necessary is just to set suitably application | coating conditions, such as temperature at the time of application | coating, and humidity, according to the composition of the photosensitive composition, etc.

As a method for drying the applied photosensitive composition, for example, there is a method of heating (baking) using a heating device such as a hot plate, but the entire photosensitive composition is heated uniformly to remove the organic solvent. Any method can be used as long as it can be volatilized sufficiently, and it is not particularly limited. Moreover, what is necessary is just to set suitably drying conditions, such as heating temperature and a heating time, according to the kind of organic solvent, the film thickness of a photosensitive composition, etc.

Examples of the exposure method of the dried photosensitive composition include a method of irradiating light with a curing light source such as an ultrahigh pressure mercury lamp through a mask corresponding to a desired pattern, but the entire photosensitive composition The method is not particularly limited as long as it can be uniformly exposed. Moreover, what is necessary is just to set suitably exposure conditions, such as the kind of light, intensity | strength, and irradiation time, according to the kind of photoinitiator, the film thickness of a photosensitive composition, etc.

As a developing method of the photosensitive composition after exposure, for example, an alkaline aqueous solution such as an aqueous solution of sodium carbonate (Na ₂ CO ₃ ), an aqueous solution of tetramethylammonium hydroxide, an aqueous solution of potassium hydroxide, or an aqueous solution of sodium hydroxide is sprayed and developed. Although there is a method of (spray development), any method that can sufficiently dissolve the alkali-soluble resin in the uncured portion, that is, a method that can remove the photosensitive composition, may be used. Is not to be done. Moreover, what is necessary is just to set suitably development conditions, such as a kind and density | concentration of alkaline aqueous solution, and development time, according to the kind of alkali-soluble resin, the film thickness of a photosensitive composition, etc.

By developing the photosensitive composition after exposure, a film that is a cured product, that is, a desired pattern having a light scattering function according to the present invention can be efficiently obtained. The pattern which concerns on this invention can be used conveniently as a scattering layer of a display apparatus, for example. Since the pattern according to the present invention can be formed by photolithography, in the manufacturing method of the display device, alignment with other patterns (underground) formed before forming the scattering layer can be performed with high accuracy. Therefore, the pattern can be formed with high definition.

The film thickness of the film as the pattern formed by using the photosensitive composition according to the present invention is in the range of 5 to 20 μm suitable for use as the scattering layer of the display device according to the present invention. More preferably, it is more preferably in the range of 5 to 15 μm, and particularly preferably in the range of 7 to 12 μm. By making the film thickness within the above range, both the alignment characteristics of blue light and the photolithography characteristics can be achieved. Moreover, it is more preferable that the coating film as the pattern has the following physical properties suitable for use as the scattering layer of the display device according to the present invention. That is, the haze measured using a haze meter is more preferably 90% or more, and the total light transmittance and diffuse transmittance are more preferably 30% or more. In addition, the alignment characteristics of blue light measured using a spectroscopic colorimeter can be accepted as a product when viewed as the display quality of a display device, compared to the calculated Lambertian (light intensity distribution). It is more preferable that the deviation is within a range of ± 5%. Therefore, the viewing angle is more preferably ± 80 degrees. Note that Lambertian is a light intensity distribution (I (θ)) represented by the formula “I (θ) = I0 × COSθ”, where I0 is the light intensity in the normal direction (θ = 0) with respect to the light emitting surface. ).

The pattern according to the present invention is used by configuring a color conversion substrate together with a red phosphor and a green phosphor as a scattering layer of the display device according to the present invention, as will be described later. The red light emitted from the red phosphor and the green light emitted from the green phosphor have an alignment characteristic of Lambertian (light intensity distribution). Therefore, in order to prevent a color shift from occurring in the front direction and the oblique direction in the display device, the alignment characteristics of the blue light must also exhibit Lambertian. The scattering layer, which is a pattern according to the present invention, has a light scattering function, and the alignment characteristic exhibits Lambertian, so that the change in chromaticity in the oblique direction with respect to the front direction in the display device is reduced, thereby Display quality can be improved.

[Display device]
For example, as shown in FIG. 1, the display device according to the present invention includes a display device (display unit) including at least a backlight 1, an optical shutter 2, and a color conversion substrate 3. In addition, the manufacturing method of a display device (display part) and the manufacturing method of a display apparatus can employ | adopt a conventionally well-known manufacturing method, and are not specifically limited.

The backlight 1 is a so-called edge light type, and includes a light source 11 having a blue LED, a blue cold cathode tube, and the like, and a light guide plate 12. When the blue light emitted from the light source 11 is incident on the end surface of the light guide plate 12, the light guide plate 12 has a function of guiding the blue light and emitting it from the surface of the optical shutter 2. On the light shutter 2 side surface of the light guide plate 12, for example, an optical sheet (not shown) having a prism shape is provided. Thereby, the said light-guide plate 12 can radiate | emit parallel blue light with high directivity.

Further, the display device according to the present invention may have a so-called direct-type display device in which the backlight 1 is composed of a plurality of light sources 11 as shown in FIG. In this display device, the light sources 11 are arranged so as to face the optical shutter 2, and thus it is more preferable to have a blue LED with high directivity.

The optical shutter 2 is composed of, for example, a liquid crystal panel or a transmissive MEMS (Micro Electro Mechanical System). When blue light emitted from the backlight 1 is incident on the optical shutter 2, the transmittance is increased. It has a function of controlling and emitting light to the color conversion substrate 3 side, that is, the visual recognition side.

The case where the optical shutter 2 is a liquid crystal panel will be further described. As shown in FIG. 3 and FIG. 9A, the liquid crystal panel that is the optical shutter 2 includes, from the backlight 1 side, the light source side polarizing plate 21, the light source side substrate 22, the liquid crystal layer 23, the viewing side substrate 24, and the viewing side. The side polarizing plate 25 is configured by being laminated in this order. The liquid crystal panel arbitrarily controls the transmittance of the blue light incident on the liquid crystal panel by applying a voltage to the liquid crystal layer 23 sealed between the pair of substrates 22 and 24. Yes.

As shown in FIG. 3, the color conversion substrate 3 is incident through the transparent substrate 31, phosphors 32 and 33 that convert the wavelength of blue light incident through the optical shutter 2, and the optical shutter 2. And a scattering layer 34 that scatters blue light. That is, the display device according to the present invention uses the light source 11 that emits blue light, converts the blue light into red light and green light by the phosphors 32 and 33, and uses the blue light from the light source 11 as it is. It is designed to be used as blue light. A specific configuration of the color conversion substrate 3 will be further described with reference to FIGS. For convenience of explanation, the upper and lower sides of the color conversion board 3 shown in FIGS. 4 to 6 are opposite to the upper and lower sides of the color conversion board 3 shown in FIG.

As shown in FIG. 4, the color conversion substrate 3 includes a transparent substrate 31 made of a material such as glass that is substantially transparent in the visible light region, and converts the blue light incident through the optical shutter 2 into red light. A red phosphor 32 that is converted and emitted to the transparent substrate 31 side, a blue phosphor incident through the optical shutter 2 is converted into green light, and a green phosphor 33 that is emitted to the transparent substrate 31 side, and an optical shutter 2 is provided with a scattering layer 34 that scatters blue light incident through 2 and emits the blue light to the transparent substrate 31 side. The red phosphor 32, the green phosphor 33, and the scattering layer 34 are regularly arranged with respect to the transparent substrate 31 to form a pattern constituting pixels, and can be displayed as a display device. .

More specifically, as shown in FIG. 9B, which is a plan view seen from the viewing side, the red phosphor 32, the green phosphor 33, and the scattering layer 34 are latticed with respect to the transparent substrate 31. The pattern which comprises a pixel is formed by arranging in order. The size and shape of each red phosphor 32, green phosphor 33, and scattering layer 34 constituting one pixel is usually a rectangle of about 30 to 120 μm × 90 to 360 μm (in FIG. 9A, Although it is the size and shape seen from the visual recognition side shown by the arrow), it is not particularly limited.

The phosphor material constituting the red phosphor 32 and the green phosphor 33 is the thickness of the phosphors 32 and 33 among various phosphor materials such as an organic phosphor material, an inorganic phosphor material, and a nano phosphor material. The thickness (film thickness), the absorptivity of blue light that excites the phosphor material, and the transmittance of red light or green light emitted from the phosphors 32 and 33 may be selected as appropriate. The phosphor material is excited when it receives blue light, generates red light or green light as excitation light, and emits it toward the transparent substrate 31 side. Examples of the organic phosphor material include red fluorescent dyes such as rhodamine dyes such as rhodamine B, and green fluorescent dyes such as coumarin dyes such as coumarin 6. Examples of the inorganic phosphor material include CdSe and ZnS. As the nanophosphor material, for example, nanoparticles made of CdSe, ZnS, etc. are uniformly diffused into a binder made of a substantially transparent resin such as silicone resin, epoxy resin, (meth) acrylic resin, etc. The material which consists of.

The scattering layer 34 is a pattern according to the present invention, and is composed of a film-like cured product (film) formed by curing the photopolymerizable (meth) acrylic monomer or the like contained in the photosensitive composition according to the present invention. Has been. It is desirable that the scattering layer 34 has substantially the same orientation characteristics as the orientation characteristics of the red phosphor 32 and the green phosphor 33. In the present invention, “substantially the same orientation characteristic” refers to an orientation characteristic in which the display quality of the display device is acceptable as a product.

Further, a reflective layer 35 is formed on the side surfaces (surfaces not parallel to the transparent substrate 31) of the red phosphor 32, the green phosphor 33, and the scattering layer 34 as necessary. The reflective layer 35 has a function of reflecting light that is not emitted from the transparent substrate 31, for example, in a lateral direction (a direction parallel to the transparent substrate 31) or the like and that is emitted from the transparent substrate 31. Thereby, the utilization efficiency of light can be improved more.

Furthermore, a black matrix (not shown) may be formed between the red phosphor 32, the green phosphor 33, and the scattering layer 34 (a gap on the transparent substrate 31) as necessary. By filling the space between the red phosphor 32, the green phosphor 33, and the scattering layer 34 with a black matrix, crosstalk of emitted light can be prevented. Further, instead of forming a black matrix, as shown in FIG. 9A, the red phosphor 32, the green phosphor 33, and the reflective layer 35 formed on the scattering layer 34 are connected to each other to prevent crosstalk. May be.

The red phosphor 32, the green phosphor 33, and the scattering layer 34 are shaped so that when the reflecting layer 35 is formed on the side surface thereof, the cross section parallel to the incident blue light is on the transparent substrate 31 side. However, when the reflective layer 35 is not formed on the side surface portion, the cross section is not limited to the trapezoidal shape, for example, a rectangular shape. The shape which becomes may be sufficient.

The pattern according to the present invention formed by using the photosensitive composition according to the present invention, that is, the scattering layer 34 has a light scattering function. That is, the display device according to the present invention has the above pattern. The film thickness of the red phosphor 32, the green phosphor 33, and the scattering layer 34, that is, the film thickness of the pattern is not particularly limited, but is more preferably in the range of 3 to 20 μm. More preferably, it is in the range of 10 μm. When the film thickness is less than 3 μm, the scattering layer 34 may not have a sufficient light scattering function. When the film thickness exceeds 20 μm, the color conversion substrate 3 may be thick.

According to the above configuration, it is possible to provide a display device with improved display quality, in which chromaticity change (color shift) does not occur between the front direction and the oblique direction.

As shown in FIG. 5, the color conversion substrate 3 may further include a low refractive index layer 36 between the transparent substrate 31 and the red phosphor 32, the green phosphor 33, and the scattering layer 34. The low refractive index layer 36 is, for example, light (shallow angle) directed in the lateral direction (direction parallel to the transparent substrate 31) among the light emitted from the red phosphor 32, the green phosphor 33, and the scattering layer 34. The light is emitted from the transparent substrate 31 by being reflected back to the reflective layer 35 side and reflected again. Thereby, the utilization efficiency of light can be improved more.

As shown in FIG. 6, the color conversion substrate 3 may further include a color filter 37 between the transparent substrate 31 and the low refractive index layer 36. The color filter 37 includes a red filter 37a, a green filter 37b, a blue filter 37c, and a black matrix 37d. The red filter 37a, the green filter 37b, and the blue filter 37c are disposed at positions where light emitted from the red phosphor 32, the green phosphor 33, and the scattering layer 34 is incident, respectively. The color purity of the light is improved and emitted to the transparent substrate 31 side. The red filter 37a and the green filter 37b generate unnecessary excitation light in the red phosphor 32 and the green phosphor 33 by removing the blue light contained in the external light incident from the transparent substrate 31 side. It also has a function to suppress this. The blue filter 37c also has a function of suppressing scattering of the light in the scattering layer 34 by removing light other than blue light included in external light incident from the transparent substrate 31 side. The black matrix 37d is formed so as to fill the space between the red filter 37a, the green filter 37b, and the blue filter 37c, and the crosstalk of the light emitted from the red phosphor 32, the green phosphor 33, and the scattering layer 34 is reduced. It comes to prevent. Thereby, the display quality can be further improved.

Further, as shown in FIGS. 10A and 10B, the color conversion substrate 3 includes a black matrix 37d formed so as to fill the space between the red phosphor 32, the green phosphor 33, and the scattering layer 34. It may be a configuration. In this configuration, the reflecting layer 35 is not formed on the side surfaces of the red phosphor 32, the green phosphor 33, and the scattering layer 34, and the cross section parallel to the incident blue light is rectangular. The black matrix 37d prevents crosstalk of light emitted from the red phosphor 32, the green phosphor 33, and the scattering layer 34. Thereby, the display quality can be further improved.

Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to the configurations of the following examples.

[Example 1]
TiO ₂ filler (average particle size 200 nm), 2-hydroxy-3-phenoxypropyl acrylate as photopolymerizable (meth) acrylic monomer, benzyl methacrylate (BZMA) / methacrylic acid (MAA) / glycidyl as alkali-soluble resin Methacrylate (GMA) copolymer, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one as a photopolymerization initiator, and diethylene glycol monobutyl ether / propylene as an organic solvent Glycol monomethyl ether acetate mixed solvent was stirred in a container so that the weight ratio was 30: 40: 30: 3: 100 in this order and mixed roughly, and then further mixed using a three-roll mill. . As a result, a photosensitive composition in which the TiO ₂ filler was uniformly dispersed was produced.

The BZMA / MAA / GMA copolymer has a weight ratio of BZMA, MAA and GMA of 75: 16.8: 8.2 (since GMA is a glycidylated product of MAA, the weight ratio of BZMA and MAA is 75: The copolymer obtained by copolymerization in 25) was used. The weight average molecular weight (Mw) of the BZMA / MAA / GMA copolymer was 10,000, and the acid value was 131 mgKOH / g. The diethylene glycol monobutyl ether / propylene glycol monomethyl ether acetate mixed solvent was a mixed solvent obtained by mixing diethylene glycol monobutyl ether and propylene glycol monomethyl ether acetate at a weight ratio of 1: 1.

The obtained photosensitive composition was coated on a glass substrate made of soda glass using an applicator under coating conditions of a temperature of 23 ° C. and a humidity of 40%. And the said mixed solvent was volatilized by heating the apply | coated photosensitive composition on a hotplate at 110 degreeC for 3 minute (baking process). Thereby, a coating film having a film thickness of 8 μm was obtained.

Thereafter, the coating film was irradiated with light at 3,000 mJ / cm ² using a super high pressure mercury lamp (manufactured by Hakuto Co., Ltd .; MAT-2500) through a chromium mask formed with a space width of 30 μm. Exposure was performed. After the exposure, an uncured portion of the coating film was removed by spraying and developing (spray development) an aqueous solution of Na ₂ CO ₃ having a concentration of 0.5% at 30 ° C. for 30 seconds. As a result, a film as a cured product, that is, a pattern having a thickness of 8 μm having a light scattering function was obtained.

When the width (space width) of the obtained pattern was confirmed, it was 35.9 μm and the pattern reproducibility was good. Therefore, it was found that a pattern having a light scattering function can be formed by photolithography.

The physical properties of the pattern, that is, the evaluation results were as follows. That is, the haze measured using a haze meter (manufactured by Nippon Denshoku Industries Co., Ltd .; NDH2000) was 91.4%, the total light transmittance was 33.3%, and the diffuse transmittance was 30.4%. Met. Moreover, as shown in FIG. 7, the alignment characteristics of blue light measured using a spectral goniochromimeter (manufactured by Nippon Denshoku Industries Co., Ltd .; GC5000) are substantially the same as the calculated Lambertian (light intensity distribution). Agreed. The viewing angle was ± 80 degrees. In FIG. 7, the horizontal axis represents the light receiving angle (degrees), the vertical axis represents the light intensity (indicated as intensity (au)), and the light intensity distribution indicated by the pattern is the front direction (normal direction relative to the light emitting surface) of the display device. FIG. 6 is a graph showing relative values when the light intensity at the light receiving angle = 0 degree is “1”.

Therefore, the pattern formed using the photosensitive composition according to the present invention can reduce the change in chromaticity in the oblique direction with respect to the front direction in the display device, thereby improving the display quality of the display device. I understand.

The composition of the photosensitive composition and the evaluation results of the pattern are summarized in Table 1. In Table 1, “◯” indicates that the pattern reproducibility is good, and “x” indicates that the pattern is poor (or the coating film is not cured). Further, “◯” indicates that the alignment characteristic of the pattern substantially shows Lambertian, “X” indicates that the alignment characteristic is not indicated, and “−” indicates that the alignment characteristic cannot be confirmed.

[Example 2]
TiO ₂ filler, 2-hydroxy-3-phenoxypropyl acrylate, BZMA / MAA / GMA copolymer, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one, and By performing the same operation as in Example 1 except that the weight ratio of the diethylene glycol monobutyl ether / propylene glycol monomethyl ether acetate mixed solvent was changed to 10: 50: 40: 3: 100 in this order, Sex compositions and patterns were prepared. The composition and pattern evaluation results of the resulting photosensitive composition are summarized in Table 1.

Example 3
The same operation as in Example 1 is carried out except that a methacrylic acid adduct of bisphenol A diglycidyl ether is used in place of 2-hydroxy-3-phenoxypropyl acrylate as the photopolymerizable (meth) acrylic monomer. Thus, a photosensitive composition and a pattern were produced. The composition and pattern evaluation results of the resulting photosensitive composition are summarized in Table 1.

Example 4
The same operation as in Example 1 except that as the alkali-soluble resin, a methyl methacrylate (MMA) / isobutyl methacrylate (IBMA) / methacrylic acid (MAA) copolymer was used instead of the BZMA / MAA / GMA copolymer. By performing the operation, a photosensitive composition and a pattern were produced. As the MMA / IBMA / MAA copolymer, a copolymer obtained by copolymerizing MMA, IBMA and MAA at a weight ratio of 50:25:25 was used. The weight average molecular weight (Mw) of the MMA / IBMA / MAA copolymer was 14,900, and the acid value was 171 mgKOH / g. The composition and pattern evaluation results of the resulting photosensitive composition are summarized in Table 1.

Example 5
Example 1 except that 2-hydroxy-3-phenoxypropyl acrylate and methacrylic acid adduct of bisphenol A diglycidyl ether were mixed at a weight ratio of 1: 1 as the photopolymerizable (meth) acrylic monomer. By performing the same operation as the operation, a photosensitive composition and a pattern were produced. The composition and pattern evaluation results of the resulting photosensitive composition are summarized in Table 1.

Example 6
TiO ₂ filler, 2-hydroxy-3-phenoxypropyl acrylate, BZMA / MAA / GMA copolymer, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one, and By carrying out the same operation as that of Example 1 except that the weight ratio of the diethylene glycol monobutyl ether / propylene glycol monomethyl ether acetate mixed solvent was 35: 40: 25: 3: 100 in this order, the photosensitivity was obtained. Sex compositions and patterns were prepared. The composition and pattern evaluation results of the resulting photosensitive composition are summarized in Table 1.

[Comparative Example 1]
By performing the same operation as that of Example 1 except that an acrylic filler (manufactured by Sekisui Plastics Co., Ltd .; SSX-102, average particle size 2 μm) was used instead of the TiO ₂ filler, Photosensitive compositions and comparative patterns were produced. However, the film thickness of the coating film was 20 μm, and the light intensity during exposure was 6,000 mJ / cm ² . The film thickness of the comparative pattern was 20 μm.

When the width (space width) of the obtained pattern was confirmed, it was 40.9 μm and the pattern reproducibility was good. However, the blue light alignment characteristics measured in the same manner as in Example 1 did not coincide with the calculated Lambertian (light intensity distribution) as shown in FIG. The viewing angle was ± 30 degrees and was narrow. Table 1 summarizes the evaluation results of the obtained comparative photosensitive composition and comparative pattern.

Since the comparative pattern of Comparative Example 1 did not use the TiO ₂ filler, it could be formed by photolithography, but did not have a sufficient light scattering function. In other words, although the transmittance in the 0 degree direction was high, the ratio of the transmittance to the 0 degree direction in the −80 to −5 degrees and 5 to 80 degrees directions was low, and thus the light scattering function was not sufficient. .

[Comparative Example 2]
TiO ₂ filler, 2-hydroxy-3-phenoxypropyl acrylate, BZMA / MAA / GMA copolymer, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one, and By comparing the diethylene glycol monobutyl ether / propylene glycol monomethyl ether acetate mixed solvent in the same manner as in Example 1 except that the weight ratio was 40: 30: 30: 3: 100 in this order, a comparison was made. Photosensitive compositions and comparative patterns were prepared. Table 1 summarizes the evaluation results of the obtained comparative photosensitive composition and comparative pattern.

In the comparative pattern of Comparative Example 2, since the light at the time of exposure did not reach the inside of the coating film because the proportion of the TiO ₂ filler exceeded 35% by mass, the surface portion was cured, but the inside was cured. There wasn't. Therefore, the coating film at the pattern forming portion is removed during development, and the pattern cannot be formed.

Note that the present invention is not limited to the above-described embodiment, and various modifications are possible within the scope shown in the claims, and the embodiment is obtained by appropriately combining technical means disclosed in the embodiment. Is also included in the technical scope of the present invention.

The display device having a photosensitive composition, a pattern and a pattern according to the present invention can be suitably used for manufacturing various electrical appliances including the display device.

DESCRIPTION OF SYMBOLS 1 Backlight 2 Optical shutter 3 Color conversion board | substrate 11 Light source 12 Light guide plate 21 Light source side polarizing plate 22 Light source side board | substrate 23 Liquid crystal layer 24 Viewing side board | substrate 25 Viewing side polarizing plate 31 Transparent substrate 32 Red fluorescent substance 33 Green fluorescent substance 34 Scattering layer 35 Reflective layer 36 Low refractive index layer 37 Color filter

Claims (7)

1. A photosensitive composition for forming a pattern having a light scattering function used in a display device,
   Including TiO ₂ filler, photopolymerizable (meth) acrylic monomer, alkali-soluble resin, photopolymerization initiator, and organic solvent,
   A photosensitive composition, wherein a ratio of the TiO ₂ filler to a total amount of the TiO ₂ filler, the photopolymerizable (meth) acrylic monomer, and the alkali-soluble resin is in a range of 10 to 35% by mass.
2. The photosensitive composition according to claim 1, wherein the average particle diameter of the TiO ₂ filler is in the range of 100 to 1,000 nm.
3. The said photopolymerizable (meth) acryl monomer is at least 1 type (meth) acryl monomer chosen from a monofunctional (meth) acryl monomer and a polyfunctional (meth) acryl monomer, The Claim 1 or 2 Photosensitive composition.
4. The photosensitive composition according to any one of claims 1 to 3, wherein the acid value of the alkali-soluble resin is in the range of 50 to 250 mgKOH / g.
5. A pattern having a light scattering function, which is formed using the photosensitive composition according to any one of claims 1 to 4.
6. The pattern according to claim 5, wherein the film thickness is in the range of 3 to 20 μm.
7. A display device having the pattern according to claim 5 or 6.

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