JP2009265515A - Colored photosensitive composition for color filter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a colored photosensitive composition for color filter, which has excellent sensitivity and developability and further provides excellent color reproducibility after curing even at a high pigment concentration. <P>SOLUTION: The colored photosensitive composition for color filter includes at least a binder resin, a multifunctional monomer, a photopolymerization initiator, a pigment, a pigment dispersant, and a solvent. The photopolymerization initiator includes a biimidazole compound having a specific substituent and a mercapto compound, the total amount of the biimidazole compound and the mercapto compound is within the range of 3-40 pts.wt. based on 100 pts.wt. of a solid component of the colored photosensitive composition, and the content of the biimidazole compound is within the range of 60-99 pts.wt. based on 100 pts.wt. in total of the biimidazole compound and the mercapto compound. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a colored photosensitive composition for a color filter which is excellent in sensitivity and developability and excellent in color reproducibility after curing even at a high pigment concentration.

  In recent years, color liquid crystal display devices are rapidly spreading as flat displays for personal computers and the like. Generally, as shown in FIG. 1, the color liquid crystal display device (101) has a color filter 1 and an electrode substrate 2 such as a TFT substrate facing each other to provide a gap portion 3 of about 1 to 10 μm. The liquid crystal compound L is filled and the periphery thereof is sealed with a sealing material 4. The color filter 1 includes a black matrix layer 6 formed in a predetermined pattern on the transparent substrate 5 to shield the boundary between pixels, and a plurality of colors (usually red (R (R)) to form each pixel. ), Green (G), blue (B) three primary colors) arranged in a predetermined order, a protective film 8 and a transparent electrode film 9 are laminated in this order from the side close to the transparent substrate. Have taken. An alignment film 10 is provided on the inner surface side of the color filter 1 and the electrode substrate 2 facing the color filter 1. Furthermore, a spacer is provided in the gap portion 3 in order to maintain a constant and uniform cell gap between the color filter 1 and the electrode substrate 2. As the spacer, pearls 11 having a constant particle diameter are dispersed, or columnar spacers 12 having a height corresponding to the cell gap as shown in FIG. It is formed in a region overlapping with the formed position. A color image is obtained by controlling the light transmittance of each of the pixels colored in each color or the liquid crystal layer behind the color filter.

  The pixel portion 7 and the black matrix layer 6 are colored layers having a predetermined pattern, and can be formed by a so-called pigment dispersion method (hereinafter referred to as a pigment dispersion method) by photolithography. According to the pigment dispersion method, a coating liquid of a colored photosensitive composition containing a pigment as a colorant and an alkali-soluble photocurable resin is applied on a transparent substrate, and the resulting coating film is applied in a predetermined pattern. It is possible to form a colored layer having a fine pattern by exposing to light and curing, and developing with alkali.

  In order to improve the color reproducibility of a color filter in recent years, the colored photosensitive composition for a color filter is required to have a high concentration of pigment contained in the colored photosensitive composition. Therefore, it is necessary to increase the amount of the non-curing component such as the pigment dispersant and the non-developing component together with the amount of the pigment contained in the colored photosensitive composition, and the content of the photosensitive component and the developing component is relatively large. Less. Therefore, the sensitivity, developability, etc. of the colored photosensitive composition are lowered, making it difficult to obtain a good quality color filter.

Patent Document 1 discloses a photosensitive composition containing a photopolymerization initiator composed of a p-dialkylaminostyrene derivative, an imidazole compound, and an aromatic mercapto compound for the purpose of improving the sensitivity of the photosensitive composition. .
Patent Document 2 describes that a photopolymerization initiator containing an aliphatic polyfunctional thiol and a biimidazole compound is used to improve sensitivity even when the pigment concentration in the photosensitive composition is high. ing.
However, biimidazoles generally used as photopolymerization initiators have poor solubility in acetates and alcohols frequently used in colored photosensitive compositions for color filters, and the sensitivity cannot be sufficiently increased. Moreover, it has also contributed to a decrease in developability.

JP 59-56403 A Japanese Patent Laid-Open No. 10-253815

  In view of the above circumstances, an object of the present invention is to provide a colored photosensitive composition for a color filter which is excellent in sensitivity and developability and excellent in color reproducibility after curing even at a high pigment concentration.

As a result of intensive studies, the present inventors have included a high concentration of a biimidazole compound having a specific substituent as a photopolymerization initiator in the colored photosensitive composition, and a combination of a mercapto compound and the above. The inventors have found that the problem can be solved and have completed the present invention.
That is, the colored photosensitive composition for a color filter according to the present invention is a colored photosensitive composition for a color filter containing at least a binder resin, a polyfunctional monomer, a photopolymerization initiator, a pigment, a pigment dispersant, and a solvent. There,
The photopolymerization initiator includes at least a biimidazole compound and a mercapto compound represented by the following chemical formula (1), and the total amount of the biimidazole compound and the mercapto compound is 100% by weight of the solid content of the colored photosensitive composition. The content of the biimidazole compound is 60 to 99 parts by weight with respect to 100 parts by weight in total of the biimidazole compound and the mercapto compound. It is a range.

(In the chemical formula (1), X is a chlorine atom, a hydrogen atom, or a vinyl group, and the number of bonds of the chlorine atom, the hydrogen atom, and the vinyl group is 4-6 for the chlorine atom and 22-22 for the hydrogen atom. 25, the vinyl group is 1-2.)

  According to the present invention, by using the biimidazole compound represented by the above chemical formula (1) as a photopolymerization initiator, the solubility in a solvent is improved. Therefore, in the colored photosensitive composition for a color filter, The biimidazole compound can be contained at a high concentration. Furthermore, by using a mercapto compound in combination, sensitivity and developability can be improved even at a high pigment concentration, and color reproducibility after curing can also be improved.

  In the colored photosensitive composition for a color filter according to the present invention, the mercapto compound is preferably mercaptobenzothiazole from the viewpoints of sensitivity and viscosity stability.

  In the colored photosensitive composition for a color filter according to the present invention, the double bond equivalent of the binder resin represented by the weight average molecular weight per double bond in the binder resin is in the range of 300 to 3000. Is preferable from the viewpoint of improving sensitivity and developability.

  In the colored photosensitive composition for a color filter according to the present invention, the solvent is propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, 3-methoxy-3-methyl-1-butyl acetate, 3-methoxybutyl acetate. 1 or more selected from the group consisting of ethyl ethoxypropionate improves the solubility of the biimidazole compound represented by the above chemical formula (1), other initiators, binder resins, and polyfunctional monomers. It is preferable from the point to make.

According to the colored photosensitive composition for a color filter according to the present invention, the use of a biimidazole compound having a specific substituent as a photopolymerization initiator improves the solubility in a solvent. The biimidazole compound can be contained at a high concentration in the composition. Furthermore, by using a mercapto compound in combination, sensitivity and developability can be improved even at a high pigment concentration, and color reproducibility after curing can also be improved.
Therefore, according to the present invention, a pattern having a good shape can be formed.

  The colored photosensitive composition for a color filter according to the present invention is a colored photosensitive composition for a color filter containing at least a binder resin, a polyfunctional monomer, a photopolymerization initiator, a pigment, a pigment dispersant, and a solvent. The photopolymerization initiator includes at least a biimidazole compound and a mercapto compound represented by the following chemical formula (1), and the total amount of the biimidazole compound and the mercapto compound is a solid content of the colored photosensitive composition 100. The range of 3 to 40 parts by weight with respect to parts by weight, and the content of the biimidazole compound is 60 to 99 parts by weight with respect to a total of 100 parts by weight of the biimidazole compound and the mercapto compound. It is the range of these.

(In the chemical formula (1), X is a chlorine atom, a hydrogen atom, or a vinyl group, and the number of bonds of the chlorine atom, the hydrogen atom, and the vinyl group is 4-6 for the chlorine atom and 22-22 for the hydrogen atom. 25, the vinyl group is 1-2.)

It is known that sensitivity and developability are improved by using a biimidazole compound and a mercapto compound in combination as a photopolymerization initiator. However, the biimidazole compound that has been conventionally used as a photopolymerization initiator has a low solubility in a solvent, so that a sufficient amount cannot be added, causing a decrease in sensitivity and developability. The effect was not acquired.
On the other hand, since the biimidazole compound represented by the chemical formula (1) has a vinyl group as a substituent, it has high solubility in a solvent and can be contained in a colored photosensitive composition at a high concentration. The sensitivity and developability can be improved.
Therefore, according to the present invention, by using the biimidazole compound represented by the chemical formula (1) and the mercapto compound in combination, the sensitivity and developability can be improved even at a high pigment concentration. Due to the density, the color density increases, and the color reproducibility after curing can also be improved.

Hereinafter, the component used for the coloring photosensitive composition for color filters which concerns on this invention is demonstrated.
In the present specification, (meth) acrylate represents acrylate and methacrylate, and (meth) acryl represents acryl and methacryl.
<Photopolymerization initiator>
The photopolymerization initiator in the colored photosensitive composition for a color filter used in the present invention contains at least a biimidazole compound and a mercapto compound represented by the following chemical formula (1).

(In the chemical formula (1), X is a chlorine atom, a hydrogen atom, or a vinyl group, and the number of bonds of the chlorine atom, the hydrogen atom, and the vinyl group is 4-6 for the chlorine atom and 22-22 for the hydrogen atom. 25, the vinyl group is 1-2.)

  In the present invention, the bonding position of the chlorine atom, hydrogen atom, and vinyl group in the chemical formula (1) may be any position that allows the chlorine atom, hydrogen atom, and vinyl group to bond with the number of bonds described above. .

Examples of the mercapto compound used in the present invention include 2-mercaptobenzothiazole, 2-mercaptobenzimidazole, 2-mercaptobenzoxazole, 5-chloro-2--2-mercaptobenzothiazole, 2-mercapto-5-methoxybenzo. Thiazole, 5-methyl-1,3,4-thiadiazole-2-thiol, 5-mercapto-1-methyltetrazole, 3-mercapto-4-methyl-4H-1,2,4-triazole, 2-mercapto-1- Examples include methylimidazole, 2-mercaptothiazoline, 1,4-dimethylmercaptobenzene, and the like. In particular, 2-mercaptobenzothiazole is preferable from the viewpoint of polymerization initiation ability. These mercapto compounds can be used alone or in combination of two or more.
The colored photosensitive composition of the present invention may contain another photopolymerization initiator as long as the effects of the present invention are not impaired.

The total amount of the biimidazole compound and the mercapto compound is preferably in the range of 3 to 40 parts by weight, particularly in the range of 5 to 35 parts by weight, based on 100 parts by weight of the solid content of the colored photosensitive composition. It is preferable that If the amount is less than 3 parts by weight, the sensitivity may decrease, and if it exceeds 40 parts by weight, the developability may decrease.
Here, the “solid content” indicates components other than the solvent in the composition.

  The content of the biimidazole compound is preferably in the range of 60 to 99 parts by weight, particularly in the range of 70 to 99 parts by weight, with respect to 100 parts by weight in total of the biimidazole compound and the mercapto compound. It is preferable that If the amount is less than 60 parts by weight, the sensitivity may decrease, and if it exceeds 99 parts by weight, the sensitivity may decrease.

<Binder resin>
The binder resin in the colored photosensitive composition for a color filter used in the present invention is not particularly limited, but since it is used for the production of a color filter, the heat resistance and the solvent used in the production process. A resin having resistance is preferable. Specific examples include photosensitive or non-photosensitive resins such as epoxy resins, acrylic resins, urethane resins, polyester resins, polyimide resins, polyolefin resins, and gelatin.

  Among the above-described binder resins, particularly preferable binder resins include alkali-soluble resins having an acidic functional group such as a carboxyl group, such as alkali-soluble acrylic resins. As the alkali-soluble resin having a carboxyl group, a copolymer of a carboxyl group-containing unsaturated monomer and another copolymerizable ethylenically unsaturated monomer is preferable, and an epoxy group and an ethylenically unsaturated group are further included in the molecule. It is preferable to add a compound having a group, such as glycidyl (meth) acrylate, and introduce an ethylenically unsaturated group in the side chain.

  Examples of the carboxyl group-containing unsaturated monomer include (meth) acrylic acid, crotonic acid, maleic acid, maleic anhydride, succinic acid mono [2- (meth) acryloyloxyethyl], and phthalic acid mono [2- (Meth) acryloyloxyethyl], ω-carboxypolycaprolactone mono (meth) acrylate and the like are preferable, and (meth) acrylic acid is particularly preferable. In addition, the carboxyl group-containing unsaturated monomer can be used alone or in combination of several kinds.

  Examples of ethylenically unsaturated monomers include methyl (meth) acrylate, n-butyl (meth) acrylate, cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, dicyclopentanyl (meth) acrylate, and allyl (meth) acrylate. , Styrene, α-methylstyrene, benzyl (meth) acrylate, hydroxyethyl (meth) acrylate, 2-dimethylaminoethyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, 2-hydroxyl (meth) ethyl acrylate, dicyclo Pentenyl (meth) acrylate and the like and macromonomers thereof; N-methylmaleimide, N-cyclohexylmaleimide, N-benzylmaleimide, N-phenylmaleimide, N-methylphenylmaleimide and the like Substituted maleimide, and the like can be mentioned. In addition, an ethylenically unsaturated monomer can be individual or can combine several types.

The double bond equivalent of the binder resin is preferably in the range of 300 to 3000, and particularly preferably in the range of 400 to 2000. If the double bond equivalent is less than 300, image sticking may occur, resulting in insufficient development. If it exceeds 3000, sensitivity may be lowered.
Here, the double bond equivalent is the weight average molecular weight per double bond in the binder resin. Moreover, the double bond equivalent of the said binder resin can be calculated | required with the following formula.

  The content of the binder resin is preferably in the range of 5 to 60% by weight, particularly in the range of 10 to 40% by weight, based on the total solid content of the colored photosensitive composition. Is preferred. This is because if the amount is less than the above range, sufficient photocurability may not be obtained. Moreover, it is because a development defect and a curing defect will arise when it exceeds the said range.

<Multifunctional monomer>
The polyfunctional monomer in the colored photosensitive composition for color filters used in the present invention is a compound having at least one ethylenically unsaturated group compatible with the binder resin, preferably at least 2 ethylenically unsaturated groups. One compound. Examples of the compound having an ethylenically unsaturated group include bifunctional (meth) acrylates and trifunctional or higher functional (meth) acrylates, preferably trifunctional or higher functional (meth) acrylates.

  Examples of the bifunctional (meth) acrylate include 1,3-butanediol (meth) acrylate, 1,4-butanediol (meth) acrylate, neopentyl glycol di (meth) acrylate, and 1,6-hexane. Diol di (meth) acrylate, polypropylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, bisphenol A di (meth) acrylate, 3 -Methylpentanediol (meth) acrylate, phthalic acid di (meth) acrylate, cyclohexylene glycol di (meth) acrylate, methoxylated cyclohexyl di (meth) acrylate and the like.

  Examples of the trifunctional or higher functional (meth) acrylate include trimethylolpropane tri (meth) acrylate, trimethylolethane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, and pentaerythritol tetra (meth) acrylate. , Dipentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, (DPHA), dipentaerythritol penta (meth) acrylate, carboxylic acid-modified dipentaerythritol pentaacrylate, and the like.

Said polyfunctional monomer can be used individually or in mixture of 2 or more types.
In addition, it is preferable that content of the polyfunctional monomer used for this invention is the range of 3 to 50 weight% with respect to the solid content whole quantity of the said colored photosensitive composition. If it is less than 3% by weight, photocuring does not proceed sufficiently, and the exposed part may be eluted during alkali development. If it exceeds 50% by weight, the alkali developability deteriorates, so there is a possibility that development cannot be performed even in an unexposed portion.

In the present invention, a monofunctional (meth) acrylate may be used in combination with the polyfunctional monomer.
Examples of the monofunctional (meth) acrylate include hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, and butane. Diol mono (meth) acrylate, allyl (meth) acrylate, butoxyethyl (meth) acrylate, t-butylaminoethyl (meth) acrylate, butyl (meth) acrylate, hexyl (meth) acrylate, ethylhexyl (meth) acrylate, lauryl ( Examples include meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl carbitol (meth) acrylate, and glycidyl (meth) acrylate.

<Pigment>
As a colorant in the colored photosensitive composition for a color filter used in the present invention, any one of known organic colorants and inorganic colorants can be selected and used. As the organic colorant, for example, dyes, organic pigments, natural pigments, and the like can be used. Moreover, as an inorganic coloring agent, an inorganic pigment, an extender pigment, etc. can be used, for example. Among these, organic pigments are preferably used because they have high color developability and high heat resistance. Examples of the organic pigment include compounds classified as pigments in the color index (C.I .; issued by The Society of Dyers and Colorists), specifically, the color index (C.I. ) Can be listed.

  CI Pigment Yellow 1, CI Pigment Yellow 3, CI Pigment Yellow 12, CI Pigment Yellow 13, CI Pigment Yellow 14, CI Pigment Yellow 15, CI Pigment Yellow 16, CI Pigment Yellow 17, CI Pigment Yellow 20, CI Pigment Yellow 24, CI Pigment Yellow 31, CI Pigment Yellow 55, CI Pigment Yellow 60, CI Pigment Yellow 61, CI Pigment Yellow 65, CI Pigment Yellow 71, CI Pigment Yellow 73, CI Pigment Yellow 74, CI Pigment Yellow 81, CI Pigment Yellow 83, CI Pigment Yellow 93, CI Pigment Yellow 95, CI Pigment Yellow 97, CI Pigment Yellow 98, CI Pigment Yellow 100, CI CI Pigment Yellow 101, CI Pigment Yellow 104, CI Pigment Yellow 106, CI Pigment Yellow 108, CI Pigment Yellow 109, CI Pigment Yellow 110, CI Pigment Yellow 113, CI Pigment Yellow 114, CI Pigment Yellow 116, CI Pigment Yellow 117, CI Pigment Yellow 119, CI Pigment Yellow 120, CI Pigment Yellow 126, CI Pigment Yellow 127, CI Pigment Yellow 128, CI Pigment Yellow 129, CI Pigment Yellow 138, CI Pigment Yellow 139, CI Pigment Yellow 150, CI Pigment Yellow 151, CI Pigment Yellow 152, CI Pigment Yellow 153, CI Pigment Yellow 154, CI Pigment .... DOO Yellow 155, C.I Pigment Yellow 156, C.I Pigment Yellow 166, C.I Pigment Yellow 168, C.I Pigment Yellow 175;

  CI Pigment Orange 1, CI Pigment Orange 5, CI Pigment Orange 13, CI Pigment Orange 14, CI Pigment Orange 16, CI Pigment Orange 17, CI Pigment Orange 24, CI Pigment Orange 34, CI Pigment Orange 36, CI Pigment Orange 38, CI Pigment Orange 40, CI Pigment Orange 43, CI Pigment Orange 46, CI Pigment Orange 49, CI Pigment Orange 51, CI Pigment Orange 61, CI Pigment Orange 63, CI Pigment Orange 64, CI Pigment Orange 71, CI Pigment Orange 73; CI Pigment Violet 1, CI Pigment Violet 19, CI Pigment Violet 23, CI Pigment Violet 29, CI Pigment Buy Olet 32, C.I. pigment violet 36, C.I. pigment violet 38;

  CI Pigment Red 1, CI Pigment Red 2, CI Pigment Red 3, CI Pigment Red 4, CI Pigment Red 5, CI Pigment Red 6, CI Pigment Red 7, CI Pigment Red 8, CI Pigment Red 9, CI Pigment Red 10, CI Pigment Red 11, CI Pigment Red 12, CI Pigment Red 14, CI Pigment Red 15, CI Pigment Red 16, CI Pigment Red 17, CI Pigment Red 18, CI Pigment Red 19, CI Pigment Red 21, CI Pigment Red 22, CI Pigment Red 23, CI Pigment Red 30, CI Pigment Red 31, CI Pigment Red 32, CI Pigment Red 37, CI Pigment Red 38, CI Pigment Red 40, CI Pigment Red 41, CI Pigment Red 42, CI Pigment Red 48: 1, CI Pigment Red 48: 2, CI Pigment Red 48: 3, CI Pigment Red 48: 4, CI Pigment Red 49: 1, CI Pigment Red 49: 2, CI CI Pigment Red 50: 1, CI Pigment Red 52: 1, CI Pigment Red 53: 1, CI Pigment Red 57, CI Pigment Red 57: 1, CI Pigment Red 57: 2, CI Pigment Red 58: 2, CI Pigment Red 58 : 4, CI Pigment Red 60: 1, CI Pigment Red 63: 1, CI Pigment Red 63: 2, CI Pigment Red 64: 1, CI Pigment Red 81: 1, CI Pigment Red 83, CI Pigment Red 88, CI Pigment Red 90: 1, CI pigmentless 97, CI Pigment Red 101, CI Pigment Red 102, CI Pigment Red 104, CI Pigment Red 105, CI Pigment Red 106, CI Pigment Red 108, CI Pigment Red 112, CI Pigment Red 113, CI Pigment Red 114, CI Pigment Red 122, CI Pigment Red 123, CI Pigment Red 144, CI Pigment Red 146, CI Pigment Red 149, CI Pigment Red 150, CI Pigment Red 151, CI Pigment Red 166, CI Pigment Red 168, CI Pigment Red 170, CI Pigment Red 171, CI Pigment Red 172, CI Pigment Red 174, CI Pigment Red 175, CI Pigment Red 176, CI Pigment Red 77, CI Pigment Red 178, CI Pigment Red 179, CI Pigment Red 180, CI Pigment Red 185, CI Pigment Red 187, CI Pigment Red 188, CI Pigment Red 190, CI Pigment Red 193, CI Pigment Red 194, CI Pigment Red 202, CI Pigment Red 206, CI Pigment Red 207, CI Pigment Red 208, CI Pigment Red 209, CI Pigment Red 215, CI Pigment Red 216, CI Pigment Red 220, CI Pigment Red 224, CI Pigment Red 226, CI Pigment Red 242, CI Pigment Red 243, CI Pigment Red 245, CI Pigment Red 254, CI Pigment Red 255, CI Pigment Red . 64, C.I Pigment Red 265;

  CI Pigment Blue 15, CI Pigment Blue 15: 3, CI Pigment Blue 15: 4, CI Pigment Blue 15: 6, CI Pigment Blue 60; CI Pigment Green 7, CI Pigment Green 36, CI Pigment Green 58; CI Pigment Brown 23 CI Pigment Brown 25; CI Pigment Black 1, Pigment Black 7.

  Specific examples of the inorganic pigment or extender pigment include titanium oxide, barium sulfate, calcium carbonate, zinc white, lead sulfate, yellow lead, zinc yellow, red rose (red iron (III) oxide), cadmium red, amber, etc. Can be mentioned. In the present invention, other pigments can be used alone or in admixture of two or more.

  In the colored photosensitive composition used for this invention, a pigment is mix | blended normally in the ratio of 5 to 60 weight% with respect to the solid content whole quantity of a colored photosensitive composition, Preferably it is 5 to 50 weight%. In addition, it is preferable from the point of color reproducibility, sclerosis | hardenability, and developability to prepare this pigment within the said range with respect to the solid content whole quantity of this coloring photosensitive composition.

<Pigment dispersant>
Any pigment dispersant may be used in the present invention as long as it can uniformly disperse the pigment, and a known pigment dispersant can be used. Specific examples include polymer dispersants such as modified polyurethane, modified polyacrylate, modified polyester, and modified polyamide, and surfactants and pigment derivatives such as phosphate esters, alkylamines, and polyoxyethylene alkylphenyl ethers. . Among these, a polymer dispersant is preferable in the present invention, and specific product names include EFKA-4046, EFKA-4047, EFKA polymer 10, EFKA polymer 400, EFKA polymer 401, EFKA polymer 4300, and EFKA polymer. 4330 (above, manufactured by Ciba Specialty Chemicals Co., Ltd.), Disperbyk111, Disperbyk161, Disperbyk165, Disperbyk167, Disperbyk182, Disperbyk2000, Disperbyk2001 (above, SE 000, ER) Manufactured by Co., Ltd.), Ajisper PB821, PB8 2 (manufactured by Ajinomoto Fine-Techno Co., Ltd.), and the like.

  The content of the pigment dispersant used in the present invention is not particularly limited as long as the above-described pigment can be uniformly dispersed, but the total solid content of the colored photosensitive composition of the present invention is not limited. Is preferably in the range of 0.5 to 30% by weight, more preferably in the range of 1 to 20% by weight. If it is smaller than the above range, it will be difficult to uniformly disperse the pigment, and if it is larger than the above range, the developability of the colored photosensitive composition may be lowered or the development residue at unexposed locations may be increased. There is sex.

<Solvent>
The colored photosensitive composition for a color filter according to the present invention contains a solvent for dispersing the pigment.
Examples of the solvent used in the colored photosensitive composition of the present invention include alcohol solvents such as methyl alcohol, ethyl alcohol, N-propyl alcohol and i-propyl alcohol; cellosolv solvents such as methoxy alcohol and ethoxy alcohol; Carbitol solvents such as ethanol and ethoxyethoxyethanol; ester solvents such as ethyl acetate, butyl acetate, methyl methoxypropionate, ethyl ethoxypropionate and ethyl lactate; ketone solvents such as acetone, methyl isobutyl ketone and cyclohexanone; propylene Propylene glycol acetate solvents such as glycol monomethyl ether acetate (PGMEA) and propylene glycol monoethyl ether acetate; methoxyethyl acetate, Alkoxyalkyl acetate solvents such as toxipropyl acetate, 3-methoxy-3-methyl-1-butyl acetate, methoxybutyl acetate, 3-methoxybutyl acetate, ethoxyethyl acetate, ethyl cellosolve acetate; methoxyethoxyethyl acetate, ethoxyethoxyethyl Carbitol acetate solvents such as acetate; ether solvents such as diethyl ether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether and tetrahydrofuran; aprotic amides such as N, N-dimethylformamide, N, N-dimethylacetamide and N-methylpyrrolidone Solvent; Lactone solvent such as γ-butyrolactone; Unsaturated hydrocarbon such as benzene, toluene, xylene, naphthalene Organic solvents; organic solvents such as saturated hydrocarbon solvents such as N-heptane, N-hexane, and N-octane.
Among these solvents, propylene glycol acetate solvents such as propylene glycol monomethyl ether acetate (PGMEA) and propylene glycol monoethyl ether acetate; methoxyethyl acetate, 3-methoxy-3-methyl-1-butyl acetate, 3-methoxy Alkoxyalkyl acetate solvents such as butyl acetate, ethoxyethyl acetate, and ethyl cellosolve acetate; carbitol acetate solvents such as methoxyethoxyethyl acetate, ethoxyethoxyethyl acetate, and butyl carbitol acetate (BCA); ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, Ether solvents such as propylene glycol diethyl ether; methoxypropio Methyl acid, ethyl ethoxypropionate, ester solvents such as ethyl lactate is preferably used. Among them, the solvent used in the present invention includes propylene glycol monomethyl ether acetate (PGMEA) propylene glycol monoethyl ether acetate, 3-methoxy-3-methyl-1-butyl acetate, 3-methoxybutyl acetate, and ethyl ethoxypropionate. It is preferable that at least one selected from the group is included from the viewpoints of solubility of other components and applicability.

These solvents may be used alone or in combination of two or more.
The colored photosensitive composition for a color filter according to the present invention is prepared by using the solvent as described above usually in a proportion of 60 to 90% by weight with respect to the total amount of the colored photosensitive composition containing the solvent. To do. When the amount of the solvent is too small, the viscosity increases and the pigment dispersibility tends to decrease. Moreover, when there are too many solvents, a pigment density | concentration will fall and it may be difficult to achieve to a target chromaticity coordinate after preparing this coloring photosensitive composition.

<Other ingredients>
Furthermore, the coloring photosensitive composition for color filters of this invention can mix | blend 1 type (s) or 2 or more types of other additives as needed. The following can be illustrated as such an additive.
a) Filler: For example, glass, alumina and the like.
b) Adhesion promoter: for example, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (2-methoxyethoxy) silane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane.
c) Leveling agents: For example, vinyl polymers such as polyoxyalkylene surfactants, fatty acid ester surfactants, special acrylic polymers, vinyl ether polymers, and the like.
d) Anti-aggregation agent: for example, sodium polyacrylate.

<Method for producing colored photosensitive composition>
The colored photosensitive composition for a color filter of the present invention is a single solvent or a mixed solvent together with other compounding components, if necessary, a binder resin, a polyfunctional monomer, a photopolymerization initiator, a pigment, and a pigment dispersant. It can be produced by mixing in a solvent and dissolving or dispersing the solid component by a known dispersion method.
However, in the above method, a large amount of pigment may not be sufficiently dispersed in the solvent. Therefore, it is preferable to prepare a pigment dispersion in which a pigment and a pigment dispersant are mixed and dispersed in a solvent in advance, and prepare a binder liquid in which other components such as a binder resin are mixed or dissolved in a solvent. Then, by mixing the obtained pigment dispersion and binder liquid and performing a dispersion treatment as necessary, a colored photosensitive composition for a color filter having excellent pigment dispersibility and stability over time of pigment dispersion can be easily obtained. can get.

  When the pigment dispersion is not prepared in advance, first the pigment, the pigment dispersant, and if necessary, a part of the binder resin are added to the solvent and mixed and stirred to disperse the pigment. By adding and mixing the remaining components including the resin, not only the dispersibility is not hindered by the other compounding components in the pigment dispersion step, but also the stability is excellent.

  Hereinafter, the present invention will be described more specifically with reference to examples. These descriptions do not limit the present invention.

(1) Preparation of pigment dispersion A pigment, a pigment dispersant, and a solvent are mixed in the following ratio, and are dispersed for 3 hours using a paint shaker (manufactured by Asada Tekko Co., Ltd.) using zirconia beads having a diameter of 0.3 mm. A red pigment dispersion, a green pigment dispersion, and a blue pigment dispersion were prepared.
[Composition of red pigment dispersion]
Irgahor Red BT-CF (Ciba Specialty Chemicals Co., Ltd.): 12 parts by weight Irgahor Yellow 2R-CF (Ciba Specialty Chemicals Co., Ltd.): 3 parts by weight Pigment dispersant (Disperbyk161: Product) Name, manufactured by Big Chemie Japan Co., Ltd., solid content in solvent: 30% by weight): 20 parts by weight Propylene glycol monomethyl ether acetate: 65 parts by weight [Composition of green pigment dispersion]
・ Lionol Green 2YS (manufactured by Toyo Ink Manufacturing Co., Ltd.): 9 parts by weight ・ Yellow Pigment E4GN (manufactured by LANXESS Corporation): 6 parts by weight Product: 6 parts by weight Propylene glycol monomethyl ether acetate: 79 parts by weight [Composition of blue pigment dispersion]
-Lionol Blue ES (Toyo Ink Manufacturing Co., Ltd.): 13 parts by weight-Rionogen Violet RL (Toyo Ink Manufacturing Co., Ltd.): 2 parts by weight-Pigment dispersant (Disperbyk 2001: trade name, Big Chemie Japan) Manufactured by Co., Ltd., solid content in solvent: 46% by weight): 13 parts by weight, propylene glycol monomethyl ether acetate: 72 parts by weight

(2) Preparation of binder resin (binder resin 1)
A mixed solution of 30 parts by weight of benzyl methacrylate, 38 parts by weight of styrene, 18 parts by weight of methacrylic acid, and t-butylperoxy-2-ethylhexanoate (perbutyl O: trade name, manufactured by NOF Corporation) In a polymerization tank containing 150 parts by weight of glycol monomethyl ether acetate, it was added dropwise at 100 ° C. over 3 hours under a nitrogen stream. After completion of dropping, the mixture was further heated at 100 ° C. for 3 hours to obtain a polymer solution. The polymer solution had a weight average molecular weight of 8,000.
The weight average molecular weight is a value in terms of polystyrene measured by gel permeation chromatography (GPC).
Next, 14 parts by weight of glycidyl methacrylate, 0.2 parts by weight of triethylamine, and 0.05 parts by weight of p-methoxyphenol are added to the obtained polymer solution, and the main chain is heated at 110 ° C. for 10 hours. Reaction of the carboxylic acid group of methacrylic acid and the epoxy group of glycidyl methacrylate was performed. During the reaction, air was bubbled through the reaction solution in order to prevent polymerization of glycidyl methacrylate. The reaction was followed by measuring the acid value of the solution. The obtained binder resin had a solid content of 38% by weight, an acid value of 75 mgKOH / g, and a weight average molecular weight of 10,000. The double bond equivalent of the binder resin was 1014.

(Binder resin 2)
A polymer solution was obtained in the same manner as in the binder resin 1 except that 18.8 parts by weight of benzyl methacrylate, 23.5 parts by weight of styrene, and 27.7 parts by weight of methacrylic acid were used instead of propylene glycol monomethyl ether acetate. . The weight average molecular weight of this polymer solution was 7500.
Next, 30 parts by weight of glycidyl methacrylate, 0.2 parts by weight of triethylamine, and 0.05 parts by weight of p-methoxyphenol were added to the obtained polymer solution, and the reaction was performed by heating at 110 ° C. for 10 hours. The obtained binder resin had a solid content of 38% by weight, an acid value of 75 mgKOH / g, and a weight average molecular weight of 10,000. The double bond equivalent of the binder resin was 473.

(3) Preparation of colored photosensitive composition The pigment dispersion prepared in (1) and other components are sufficiently mixed in the following proportions, stirred with a dissolver for 1 hour, and mixed uniformly to obtain each colored photosensitive composition. A sex composition was prepared.

Example 1
[composition]
-Red pigment dispersion of (1) above: 35.2 parts by weight-Binder resin 1: 7.2 parts by weight-Aronix TO-1382 (manufactured by Toagosei Co., Ltd.): 6.8 parts by weight-Biimidazole compound ( Speed Cure 1311A: trade name, manufactured by Nippon Shibel Hegner Co., Ltd.): 1 part by weight, 2-mercaptobenzothiazole: 0.2 part by weight, Irgacure 907 (manufactured by Ciba Specialty Chemicals Co., Ltd.): 0.5 Parts by weight · KBE-503 (manufactured by Shin-Etsu Chemical Co., Ltd.): 0.3 parts by weight · propylene glycol monomethyl ether acetate: 48.8 parts by weight

(Example 2)
[composition]
-Green pigment dispersion of (1) above: 41.6 parts by weight-Binder resin 1: 6.2 parts by weight-Aronix TO-1382 (manufactured by Toagosei Co., Ltd.): 5.9 parts by weight-Biimidazole compound ( Speed Cure 1311A: trade name, manufactured by Nippon Shibel Hegner Co., Ltd.): 1 part by weight, 2-mercaptobenzothiazole: 0.2 part by weight, Irgacure 907 (manufactured by Ciba Specialty Chemicals Co., Ltd.): 0.5 Parts by weight · KBE-503 (manufactured by Shin-Etsu Chemical Co., Ltd.): 0.3 parts by weight · propylene glycol monomethyl ether acetate: 44.3 parts by weight

(Example 3)
[composition]
-Blue pigment dispersion of (1) above: 24.1 parts by weight-Binder resin 1: 9.5 parts by weight-Aronix TO-1382 (manufactured by Toagosei Co., Ltd.): 9.0 parts by weight-Biimidazole compound ( Speed Cure 1311A: trade name, manufactured by Nippon Shibel Hegner Co., Ltd.): 1 part by weight, 2-mercaptobenzothiazole: 0.2 part by weight, Irgacure 907 (manufactured by Ciba Specialty Chemicals Co., Ltd.): 0.5 Part by weight · KBE-503 (Shin-Etsu Chemical Co., Ltd.): 0.3 part by weight · Propylene glycol monomethyl ether acetate: 55.4 parts by weight

Example 4
[composition]
-Green pigment dispersion of (1) above: 41.6 parts by weight-Binder resin 2: 6.2 parts by weight-Aronix TO-1382 (manufactured by Toagosei Co., Ltd.): 5.9 parts by weight-Biimidazole compound ( Speed Cure 1311A: trade name, manufactured by Nippon Shibel Hegner Co., Ltd.): 1 part by weight, 2-mercaptobenzothiazole: 0.2 part by weight, Irgacure 907 (manufactured by Ciba Specialty Chemicals Co., Ltd.): 0.5 Parts by weight · KBE-503 (manufactured by Shin-Etsu Chemical Co., Ltd.): 0.3 parts by weight · propylene glycol monomethyl ether acetate: 44.3 parts by weight

(Comparative Example 1)
[composition]
-Green pigment dispersion of (1) above: 41.6 parts by weight-Binder resin 1: 6.2 parts by weight-Aronix TO-1382 (manufactured by Toagosei Co., Ltd.): 5.9 parts by weight-Biimidazole compound ( 2-2′-bis (2-chlorophenyl) -4,5,4 ′, 5′-tetraphenyl-1,2′-biimidazole: chemical name, biimidazole: trade name, manufactured by Kurokin Kasei Co., Ltd.) : 1 part by weight-2-mercaptobenzothiazole: 0.2 part by weight-Irgacure 907 (manufactured by Ciba Specialty Chemicals): 0.5 part by weight-KBE-503 (manufactured by Shin-Etsu Chemical): 0.3 Parts by weight, propylene glycol monomethyl ether acetate: 44.3 parts by weight

(Comparative Example 2)
[composition]
-Green pigment dispersion of (1) above: 41.6 parts by weight-Binder resin 1: 6.2 parts by weight-Aronix TO-1382 (manufactured by Toagosei Co., Ltd.): 5.9 parts by weight-Biimidazole compound ( 2-2′-bis (2-chlorophenyl) -4,5,4 ′, 5′-tetraphenyl-1,2′-biimidazole: chemical name, biimidazole: trade name, manufactured by Kurokin Kasei Co., Ltd.) : 0.5 part by weight · 2-mercaptobenzothiazole: 0.2 part by weight · Irgacure 907 (manufactured by Ciba Specialty Chemicals): 0.5 part by weight · KBE-503 (manufactured by Shin-Etsu Chemical Co., Ltd.): 0 .3 parts by weight / propylene glycol monomethyl ether acetate: 44.8 parts by weight

(4) Formation of coating film Each colored photosensitive composition was applied onto a color filter glass substrate by spin coating.
Thereafter, prebaking was performed on a hot plate at 70 ° C. for 3 minutes. Next, the applied coating film was exposed through a photomask so that the integrated exposure amount was 60 mJ / cm ² . Thereafter, development was performed with an aqueous potassium hydroxide solution at a temperature of 25 ° C. and 0.05%, followed by heating in an oven at 230 ° C. for 20 minutes and post-baking to form a pixel pattern on the substrate.

(Evaluation results)
The following evaluation was performed on each of the above examples and comparative examples. The results are listed in Table 1.
(1) Solubility of photopolymerization initiator Each colored photosensitive composition is put in a beaker and stirred for 1 hour, and then visually observed whether the photopolymerization initiator (biimidazole compound and mercapto compound) remains undissolved. did.
In Comparative Example 1, because the biimidazole compound remained undissolved, the developability and sensitivity could not be evaluated.
<Judgment>
-There is no undissolved residue: ○
・ There is unmelted residue: ×
(2) Developability In the development process at the time of forming the coating film, the time until the unexposed area was developed and the pattern was formed was measured.
<Judgment>
-The unexposed area was developed and a pattern was formed within 60 seconds:
-Unexposed areas were not developed within 60 seconds, and no pattern was formed: x
(3) Sensitivity In the obtained pixel pattern, the presence or absence of a pattern defect was observed with an optical microscope.
<Judgment>
・ No missing pattern: ○
-There is a missing pattern: ×

(Summary of results)
From Table 1 above, in Examples 1 to 4 in which a biimidazole compound having a specific substituent and a mercapto compound are used in combination, the biimidazole compound is dissolved in a solvent at a high concentration to improve developability and sensitivity. did it. On the other hand, in Comparative Example 1, since the biimidazole compound remained undissolved in the solvent, the developability and sensitivity could not be evaluated. In Comparative Example 2, the amount of the biimidazole compound used in Comparative Example 1 was halved, so that there was no undissolved residue in the solvent and pattern formation was possible. However, the sensitivity was poor and the pattern lacked. It was.

It is typical sectional drawing about an example of a liquid crystal panel. It is typical sectional drawing about another example of a liquid crystal panel.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Color filter 2 Electrode substrate 3 Gap part 4 Sealing material 5 Transparent substrate 6 Black matrix layer 7 (7R, 7G, 7B) Pixel 8 Protective film 9 Transparent electrode film 10 Orientation film 11 Pearl 12 Columnar spacer

Claims (4)

A colored photosensitive composition for a color filter containing at least a binder resin, a polyfunctional monomer, a photopolymerization initiator, a pigment, a pigment dispersant, and a solvent,
The photopolymerization initiator includes at least a biimidazole compound and a mercapto compound represented by the following chemical formula (1), and the total amount of the biimidazole compound and the mercapto compound is 100% by weight of the solid content of the colored photosensitive composition. The content of the biimidazole compound is 60 to 99 parts by weight with respect to 100 parts by weight in total of the biimidazole compound and the mercapto compound. A colored photosensitive composition for a color filter, characterized by being in a range.

(In the chemical formula (1), X is a chlorine atom, a hydrogen atom, or a vinyl group, and the number of bonds of the chlorine atom, the hydrogen atom, and the vinyl group is 4-6 for the chlorine atom and 22-22 for the hydrogen atom. 25, the vinyl group is 1-2.)   The colored photosensitive composition for a color filter according to claim 1, wherein the mercapto compound is mercaptobenzothiazole.   The color filter according to claim 1 or 2, wherein a double bond equivalent of the binder resin represented by a weight average molecular weight per double bond in the binder resin is in a range of 300 to 3000. Colored photosensitive composition for use.   The solvent is one or more selected from the group consisting of propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, 3-methoxy-3-methyl-1-butyl acetate, 3-methoxybutyl acetate, and ethyl ethoxypropionate. The coloring photosensitive composition for color filters as described in any one of Claims 1 thru | or 3 characterized by the above-mentioned.

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