JP2008065040A - Photosensitive resin composition for color filter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photosensitive resin composition for a color filter having high sensitivity and excellent curability and storage stability. <P>SOLUTION: The photosensitive resin composition for a color filter comprises a binder resin, a compound having an ethylenically unsaturated double bond, a colorant, a photopolymerization initiator containing an imidazole dimer, and a sensitizer containing a polyfunctional secondary thiol compound. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a photosensitive resin composition for a color filter used, for example, for forming a black matrix or a colored layer in a color filter, and a color filter produced using the same.

  In recent years, with the development of personal computers, particularly portable personal computers, the demand for liquid crystal display devices, particularly color liquid crystal display devices, has been increasing. This color liquid crystal display device is usually provided with a color filter having a colored layer of three primary colors of red (R), green (G), and blue (B) and a black matrix (light-shielding portion) for partitioning the colored layers. When the electrodes corresponding to the R, G, and B pixels of this color filter are turned on and off, the liquid crystal operates as a shutter, and light passes through each of the R, G, and B pixels to produce color. Display is performed.

  Conventionally, a black matrix in such a color filter has been formed by patterning a deposited metal chromium film by a photolithography method, but in recent years, a black pigment or the like is dispersed as a light-shielding material due to environmental problems. It has replaced the method formed using the photosensitive resin composition. When such a method is used, it is necessary to increase the content of the light shielding material in order to develop a light shielding property equivalent to that of the metal chromium film. However, when the content of the light-shielding material is increased, there is a problem in that the light-shielding property is increased, so that the sensitivity at the time of exposure is lowered and the developability is poor.

  In order to increase the sensitivity of such a photosensitive resin composition, various photopolymerization initiator systems have been studied. For example, examples of using a combination of a photopolymerization initiator imidazole dimer and a polyfunctional thiol are known. (Patent Document 1). When such an imidazole dimer is used, a decrease in photocurability is compensated for by a thiol compound such as a polyfunctional thiol acting as a chain transfer agent.

JP 2005-331938 A

  However, although the primary thiol compound exemplified in Patent Document 1 is highly sensitive, it tends to cause a chemical reaction with other materials contained therein, the pot life (product life) is shortened, and the storage stability is inferior. It has the problem that. In particular, when it reacts with the resin, gelation occurs, the viscosity increases, and the coating suitability is impaired. Moreover, when the addition amount of the thiol compound as described above is reduced from the viewpoint of pot life, the pot life is extended, but the sensitivity is lowered and the curability is lowered.

  On the other hand, a method of forming a colored layer in the color filter by a photolithography method using a photosensitive resin composition is generally used. In the photosensitive resin composition used for forming such a colored layer, a highly sensitive one is required from the viewpoints of high definition and productivity improvement of the color filter. Even when a photopolymerization initiator system comprising a combination of a dimer and a thiol compound is used, problems such as storage stability and a decrease in sensitivity occur.

  Therefore, it is desired to provide a photosensitive resin composition for a color filter that does not decrease sensitivity and has excellent storage stability.

  As a result of researches, the inventors have found that the acid dissociation constant of the primary thiol compound is relatively large as one of the causes of poor storage stability, and as a result, it tends to cause chemical reaction with other materials. I found it.

  The present invention includes a binder resin, a compound having an ethylenically unsaturated double bond, a colorant, a photopolymerization initiator containing an imidazole dimer, and a sensitizer containing a polyfunctional secondary thiol compound. The photosensitive resin composition for color filters characterized by containing is provided.

  According to the present invention, since the polyfunctional secondary thiol compound has a relatively low acid dissociation constant, it does not adversely affect the photopolymerization initiator, so that the sensitivity does not decrease during storage. It can be set as the photosensitive resin composition for filters. In addition, according to the present invention, the polyfunctional secondary thiol compound has a low reactivity with a binder resin and the like, so that gelation or the like hardly occurs and the photosensitive resin composition for a color filter having excellent storage stability. It can be. Furthermore, according to the present invention, since the polyfunctional secondary thiol compound is a compound having a plurality of thiol groups, the crosslinkability can be improved.

  In the said invention, it is preferable that the said photoinitiator contains an oxime ester type compound further. When the oxime ester compound coexists with the polyfunctional primary thiol compound, the initiator function is impaired by the polyfunctional primary thiol compound, but when coexisted with the polyfunctional secondary thiol compound, Since it is not adversely affected, the initiator function can be exhibited. Therefore, when an oxime ester-based compound is used in the present invention, an oxime ester-based compound having a high initiator function works effectively, and thus the photosensitive resin composition for color filters having improved sensitivity, surface curability, and patterning property; It becomes possible to do.

  In the present invention, the colorant may be a black colorant. In this case, it can be set as the photosensitive resin composition for black matrices excellent in sclerosis | hardenability and storage stability with high sensitivity.

  Furthermore, in this invention, it is preferable that the said binder resin contains the epoxy acrylate resin which has a fluorene structure. This is because the epoxy acrylate resin having a fluorene structure is superior in heat resistance and chemical resistance as commonly used acrylic resins and urethane resins as the binder resin.

  Furthermore, in the present invention, the colorant may be a chromatic colorant. In this case, a photosensitive resin composition for a colored layer having high sensitivity and excellent curability and storage stability can be obtained.

  The present invention provides a color filter comprising a cured film obtained by curing the above-described photosensitive resin composition for a color filter. According to the present invention, it is possible to obtain a high-quality color filter having a high light-shielding property and having a high-definition black matrix and a high-definition colored layer.

  According to the present invention, it is possible to obtain a photosensitive resin composition for a color filter that is less susceptible to gelation and excellent in storage stability without reducing sensitivity.

  The present invention relates to a photosensitive resin composition for a color filter (hereinafter sometimes simply referred to as a photosensitive resin composition) and a color filter having a cured film formed using the same. Each will be described separately below.

A. Photosensitive resin composition for color filters First, the photosensitive resin composition for color filters of the present invention will be described. The photosensitive resin composition for a color filter of the present invention comprises a binder resin, a compound having an ethylenically unsaturated double bond, a colorant, a photopolymerization initiator containing an imidazole dimer, and a polyfunctional secondary. And a sensitizer containing a thiol compound.

  In general, when an imidazole dimer is used as a photopolymerization initiator used in the photosensitive resin composition, a polyfunctional thiol compound is often used as a sensitizer from the viewpoint of improving sensitivity and developability. However, when a polyfunctional primary thiol compound is used as a sensitizer, since the acid dissociation constant is relatively high, the photopolymerization initiator is adversely affected during storage, and the sensitivity decreases with time. There was a problem.

  On the other hand, since the polyfunctional secondary thiol compound used in the present invention has a low acid dissociation constant as compared with the polyfunctional primary thiol, the stability in the photosensitive resin composition is polyfunctional primary. Since it is superior to thiol compounds, it does not adversely affect the photopolymerization initiator. Therefore, the function of the photopolymerization initiator and the function of the sensitizer as a chain transfer agent are not impaired during storage, and the sensitivity to light can be maintained. Therefore, according to the present invention, it is possible to obtain a photosensitive resin composition for a color filter in which the sensitivity does not decrease during storage.

  In the present invention, since the polyfunctional secondary thiol compound has a lower acid dissociation constant than the polyfunctional secondary thiol compound as described above, the reactivity with the binder resin is low. It is possible to prevent gelation due to this reaction and to prevent an increase in viscosity. Therefore, it has the advantage that it can be set as the photosensitive resin composition for color filters excellent in the storage stability which does not react with other materials, such as binder resin.

Furthermore, according to the present invention, since the polyfunctional secondary thiol compound is a compound having a plurality of thiol groups that can serve as crosslinking points, it is possible to provide a highly crosslinkable photosensitive resin composition for color filters. It becomes. Therefore, it becomes possible to form a film having a high crosslinking density by using the photosensitive resin composition for a color filter of the present invention.
Hereinafter, each material contained in the photosensitive resin composition for a color filter of the present invention will be described in detail.

1. Sensitizer First, the sensitizer contained in the photosensitive resin composition for a color filter of the present invention will be described. The sensitizer used in the present invention contains a polyfunctional secondary thiol compound. In the present invention, the polyfunctional secondary thiol compound has a function as a chain transfer agent.

  The polyfunctional secondary thiol compound used in the present invention is not particularly limited as long as it is a secondary thiol compound having two or more thiol groups in one molecule. For example, two thiol groups are aliphatic. The compound can be directly bonded to the group. Specifically, compounds represented by the following structural formulas (1) to (4) can be given.

In the present invention, among the compounds represented by the structural formulas (1) to (4) described above, the compounds represented by the structural formulas (3) and (4) are preferable. Since the compounds represented by the structural formulas (3) and (4) have a high thiol value per mole, even if the addition amount is reduced, the same curability as the compounds represented by the structural formulas (1) and (2) is obtained. Because it can. Further, since structural formulas (3) and (4) are aliphatic compounds, their compatibility with solvents and binder resins is superior to aromatic compounds such as structural formulas (1) and (2). It is. The reason for this is presumed that the aromatic compound has a rigid molecular structure, so that the degree of conformational freedom is low and the affinity with a solvent or the like is lower than that of the aliphatic compound.
Note that since aliphatic compounds such as structural formulas (3) and (4) have a small atomic refractive index, the influence on contrast is increased even when the amount added is increased, as shown in structural formulas (1) and (2). Since it is estimated that it is small compared with a compound, when using the photosensitive resin composition of this invention for formation of a colored layer, it is especially preferable.

  The amount of the polyfunctional secondary thiol compound used is preferably in the range of 0.01% by mass to 5% by mass in the solid content component of the photosensitive resin composition, and more preferably 0.1% by mass to It is preferable to be in the range of 3.0% by mass, particularly in the range of 0.7% to 1.2% by mass. When the usage-amount of a polyfunctional secondary thiol compound exceeds the said range, a sensitivity will be too high, progress of hardening reaction cannot be controlled easily, and there exists a possibility that it may become difficult to form a fine pattern. Moreover, if the usage-amount of a polyfunctional secondary thiol compound is less than the said range, sufficient sensitivity and curability may not be obtained.

Moreover, the said sensitizer may contain another sensitizer other than a polyfunctional secondary thiol compound. As such other sensitizers, general sensitizers other than the polyfunctional secondary thiol compound can be used, and are appropriately selected depending on the member to be formed.
For example, when the photosensitive resin composition for color filters of the present invention is used for forming a black matrix, other sensitizers preferably used include compounds having a 3-amino-4-methoxy-benzenesulfonyl skeleton and aromatics. Mention may be made of amine compounds.
For example, when using the photosensitive resin composition for color filters of this invention for formation of a colored layer, as another sensitizer preferably used, an aromatic amine compound can be mentioned, for example.

  In addition, when the said sensitizer contains sensitizers other than a polyfunctional secondary thiol compound, as usage-amount of all sensitizers, in the solid content component of the photosensitive resin composition , Preferably in the range of 0.01% by mass to 5% by mass, more preferably in the range of 0.1% by mass to 3.0% by mass, especially in the range of 0.7% by mass to 1.2% by mass. It is preferable that

2. Photopolymerization initiator Next, the photopolymerization initiator contained in the photosensitive resin composition for a color filter of the present invention will be described. The photopolymerization initiator used in the present invention contains an imidazole dimer.

  Specific examples of the imidazole dimer include 2- (o-chlorophenyl) -4,5-phenylimidazole dimer, 2- (o-chlorophenyl) -4,5-di (m-methoxyphenyl) imidazole 2 2-mer, 2- (o-fluorophenyl) -4,5-diphenylimidazole dimer, 2- (o-methoxyphenyl) -4,5-diphenylimidazole dimer, 2,4,5-triarylimidazole Dimer, 2- (o-chlorophenyl) -4,5-di (m-methylphenyl) imidazole dimer, 2- (o-chlorophenyl-4,5-di (p-tolyl) imidazole dimer, etc. Can be mentioned.

  The amount of the imidazole dimer used is preferably in the range of 0.01% by mass to 50% by mass in the solid content component of the photosensitive resin composition, particularly 0.3% by mass to 30% by mass. It is preferable that it is in the range of 0.7 mass%-20 mass% especially. When the amount of the imidazole dimer used exceeds the above range, the sensitivity becomes too high, and the pattern tends to be difficult to thin. Moreover, when the usage-amount of an imidazole dimer is less than the said range, reactivity may fall.

  Moreover, the said photoinitiator may contain another photoinitiator other than an imidazole dimer. The other photopolymerization initiator may be a general photopolymerization initiator, but is preferably an oxime ester compound in the present invention. The reason why the oxime ester-based compound is preferable is as follows. In general, oxime ester compounds are often used as photopolymerization initiators because of improved sensitivity, high surface curability, ease of pattern line width adjustment, etc., especially by combining with imidazole dimers. Since these effects become more remarkable, the oxime ester compound is preferably used in combination with an imidazole dimer. However, when an oxime ester compound is used in combination with a sensitizer having a relatively strong acid such as a polyfunctional primary thiol compound, the oxime ester moiety is affected by the acid because it is relatively weak against acid. As a result, the initiator function of the oxime ester compound may be inhibited. On the other hand, when an oxime ester compound is used in combination with a polyfunctional secondary thiol compound that is a sensitizer used in the present invention, the oxime ester compound is adversely affected by the polyfunctional secondary thiol compound. There is no loss of function as an initiator. Therefore, by using the oxime ester compound in combination with the imidazole dimer in the present invention, it becomes possible to make use of the high initiator function of the oxime ester compound, and it is easy to adjust the line width of the pattern with higher sensitivity. It becomes possible to set it as the photosensitive resin composition which can provide alkali resistance from the high curability of the surface.

  Such an oxime ester compound is not particularly limited as long as it is generally used as a photopolymerization initiator. Specifically, a compound represented by the following structural formulas (5) and (6) is used. Can be mentioned.

  The amount of the oxime ester compound used is usually in the range of 0.01% by mass to 30% by mass in the solid content component of the photosensitive resin composition, and in particular, 0.05% by mass to 20% by mass. It is preferable to be within the range. By using the amount of the oxime ester compound in the above range, a photosensitive resin composition for a color filter capable of forming a precise pattern with higher sensitivity and higher surface curability can be obtained. It becomes possible.

In the present invention, as the other photopolymerization initiator, a general photopolymerization initiator can be used in addition to the oxime ester compound, and it is appropriately selected according to the member to be formed.
For example, when the photosensitive resin composition for a color filter of the present invention is used for forming a black matrix, the other photopolymerization initiator is preferably a triazine photopolymerization initiator, and more preferably a chlorine triazine photopolymerization initiator. In particular, a triazine photopolymerization initiator represented by the following general formula (7) is preferable.

（式（７）中、Ｒは−ＣＸ_３、アルキル基、アリール基、アルケニル基、複素環基、または縮合多環式炭化水素基を表し、Ｘはハロゲン原子を表す。）

(In formula (7), R represents —CX ₃ , an alkyl group, an aryl group, an alkenyl group, a heterocyclic group, or a condensed polycyclic hydrocarbon group, and X represents a halogen atom.)

  This is because, when the triazine photopolymerization initiator is used, the chloro radical generated in the reaction process has a long lifetime, and thus the reaction efficiency is superior to other radicals.

  In addition, when the said photoinitiator contains other sensitizers other than an imidazole dimer, as the usage-amount of all photoinitiators, in the solid content component of the photosensitive resin composition, It is preferably within a range of 0.01% by mass to 50% by mass, and more preferably within a range of 0.1% by mass to 30% by mass, and particularly preferably within a range of 0.5% by mass to 20% by mass. .

3. Colorant Next, the colorant contained in the photosensitive resin composition for a color filter of the present invention will be described. The colorant used in the present invention is not particularly limited and is appropriately selected depending on the use of the photosensitive resin composition.

  When using the photosensitive resin composition of this invention for formation of a black matrix, a black coloring agent is used as a coloring agent. As the black colorant, a black pigment is usually used. As the black pigment to be used, a black pigment obtained by mixing one or more of inorganic pigments and organic pigments is used.

  Known inorganic black pigments can be used, and specific examples include carbon black and titanium black.

  Moreover, as an organic pigment, a well-known thing can be used, Specifically, what mixed the chromatic organic pigment of three colors of red, green, and blue as shown in the following Table 1 and Table 2 etc. are mentioned. be able to.

  When using the photosensitive resin composition of this invention for formation of a colored layer, a chromatic colorant is used as a colorant. As the chromatic colorant, known pigments can be used, and organic pigments and inorganic pigments can be used. The organic pigments that can be used in the present invention are shown in Tables 1 and 2 below.

  In addition, examples of inorganic pigments that can be used for forming the colored layer include zinc white, lead sulfate, yellow lead, zinc yellow, bengara, cadmium red, ultramarine blue, bitumen, chromium oxide green, cobalt green, and amber. Can do.

  As the usage-amount of the said coloring agent, it adjusts suitably according to the use of the photosensitive resin composition, and can be used as a general usage-amount.

4). Next, the binder resin contained in the photosensitive resin composition for a color filter of the present invention will be described. Although it does not specifically limit as binder resin used for this invention, Since it is used for manufacture of a color filter, it is resin which has heat resistance and the tolerance to the organic solvent used in a manufacturing process. Is preferred. Specific examples include photosensitive or non-photosensitive resins such as epoxy resins, acrylic resins, urethane resins, polyester resins, polyimide resins, and polyolefin resins.

  When using the photosensitive resin composition of this invention for formation of a black matrix, as a binder resin especially preferable among the above-mentioned, it is an epoxy resin, and the epoxy acrylate resin which has a fluorene structure is especially preferable. This is because heat resistance and chemical resistance are improved by using an epoxy acrylate resin having a fluorene structure.

  Specific examples of the epoxy acrylate resin having a fluorene structure used in the present invention include compounds represented by the following general formula (8).

（式（８）中、Ｒ^１およびＲ^２は互いにそれぞれ独立して、アルキル基、アリール基または複素環基を表す。）

(In Formula (8), R ¹ and R ² each independently represent an alkyl group, an aryl group, or a heterocyclic group.)

  Moreover, when using the photosensitive resin composition of this invention for formation of a colored layer, acrylate resin, polyester resin, and urethane resin are generally used as binder resin among the above-mentioned.

  As the usage-amount of the said binder resin, it exists in the range of 1 mass%-50 mass% normally in the solid component of the photosensitive resin composition, Preferably it exists in the range of 2 mass%-30 mass%. This is because if the amount of the binder resin used is too small, sufficient photocurability may not be obtained. Further, when the amount of the binder resin used is too large, the ratio of the colorant becomes relatively low, and a sufficient color density cannot be obtained.

5. Next, the compound which has an ethylenically unsaturated double bond contained in the photosensitive resin composition for color filters of this invention is demonstrated. The compound having an ethylenically unsaturated double bond used in the present invention is not particularly limited as long as it can be polymerized with the binder resin, but in the present invention, it is preferably a polyfunctional monomer. Such a polyfunctional monomer has a plurality of polymerizable functional groups, and among them, an acryloyl group or a methacryloyl group, that is, a polyfunctional (meth) acrylate is preferable.

  Examples of polyfunctional (meth) acrylates include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, hexanediol (meth) acrylate, long chain aliphatic di (meth) acrylate, and neopentyl glycol di (meth) acrylate. , Hydroxypivalate neopentyl glycol di (meth) acrylate, stearic acid modified pentaerythritol di (meth) acrylate, propylene di (meth) acrylate, glycerol (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (Meth) acrylate, tetramethylene glycol di (meth) acrylate, butylene glycol di (meth) acrylate, dicyclopentanyl di (meth) acrylate, Reethylene glycol di (meth) acrylate, polypropylene di (meth) acrylate, triglycerol di (meth) acrylate, neopentyl glycol modified trimethylolpropane di (meth) acrylate, allylated cyclohexyl di (meth) acrylate, methoxylated cyclohexyl di ( (Meth) acrylate, acrylated isocyanurate, bis (acryloxyneopentyl glycol) adipate, bisphenol A di (meth) acrylate, tetrabromobisphenol A di (meth) acrylate, bisphenol S di (meth) acrylate, butanediol di (meth) ) Acrylate, phthalic acid di (meth) acrylate, phosphoric acid di (meth) acrylate, zinc di (meth) acrylate and other bifunctional (meth) acrylates It is.

  Examples of the polyfunctional (meth) acrylate include trimethylolpropane tri (meth) acrylate, trimethylolethane tri (meth) acrylate, glycerol tri (meth) acrylate, pentaerythritol di (meth) acrylate, pentaerythritol tri (meth) ) Acrylate, alkyl-modified dipentaerythritol tri (meth) acrylate, tri (meth) acrylate phosphate, tris (acryloxyethyl) isocyanurate, tris (methacryloxyethyl) isocyanurate, pentaerythritol tetra (meth) acrylate, dipenta Erythritol tetra (meth) acrylate, ditrimethylolpropane tetraacrylate, alkyl-modified dipentaerythritol tetra (meth) acrylate, dipen Erythritol monohydroxypenta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, alkyl-modified dipentaerythritol penta (meth) acrylate, urethane tri (meth) acrylate, ester tri (meth) acrylate, urethane hexa (meth) acrylate, Trifunctional or higher functional (meth) acrylates such as ester hexa (meth) acrylate are exemplified.

  These polyfunctional (meth) acrylates may be used alone or in combination of two or more.

  In particular, when excellent photocurability (high sensitivity) is required for the photosensitive resin composition of the present invention, the polyfunctional (meth) acrylate has two polymerizable double bonds in one molecule ( It is preferable to have at least two (trifunctional), and more preferably three (trifunctional).

  The content of the compound having an ethylenically unsaturated double bond is preferably 8% by mass or more, more preferably in the range of 9% by mass to 19% by mass with respect to the solid content in the photosensitive resin composition. Is within. If the content of the compound having an ethylenically unsaturated double bond is too small, the photocuring may not proceed sufficiently and the exposed part may be eluted. In addition, if the content of the compound having an ethylenically unsaturated double bond is too large, development may not be possible even in an unexposed part, and depending on the degree of polymerization of the photosensitive resin composition, there is a possibility that the non-adhesiveness of the film may be lost. is there.

6). Other materials The photosensitive resin composition for a color filter of the present invention includes the above sensitizer, photopolymerization initiator, colorant, binder resin, and compound having an ethylenically unsaturated double bond, if necessary, It may contain a solvent or an additive.

(solvent)
The solvent used in the present invention is not particularly limited as long as it is an organic solvent that does not react with each component in the photosensitive resin composition and can dissolve or disperse them. Specifically, alcohols such as methanol and ethanol; ethers such as tetrahydrofuran; glycol ethers such as ethylene glycol monomethyl ether, ethylene glycol dimethyl ether, ethylene glycol methyl ethyl ether, and ethylene glycol monoethyl ether; methyl cellosolve acetate, ethyl Ethylene glycol alkyl ether acetates such as cellosolve acetate; diethylene glycols such as diethylene glycol monomethyl ether, diethylene glycol diethyl ether, diethylene glycol dimethyl ether, diethylene glycol ethyl methyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether; propylene glycol methyl ether Propylene glycol alkyl ether acetates such as cetate and propylene glycol ethyl ether acetate; aromatic hydrocarbons such as toluene and xylene; ketones such as methyl ethyl ketone, methyl amyl ketone, cyclohexanone and 4-hydroxy-4-methyl-2-pentanone And ethyl 2-hydroxypropionate, methyl 2-hydroxy-2-methylpropionate, ethyl 2-hydroxy-2-methylpropionate, ethyl ethoxyacetate, ethyl hydroxyacetate, methyl 2-hydroxy-2-methylbutanoate, Estes such as methyl 3-methoxypropionate, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate, ethyl acetate, butyl acetate, methyl lactate, ethyl lactate Kind; and the like. These solvents may be used alone or in combination of two or more.

  Of these, glycol ethers, alkylene glycol alkyl ether acetates, diethylene glycol dialkyl ethers, and diethylene glycols are preferable as the solvent. Particularly preferred are ethyl 3-ethoxypropionate, ethyl lactate, propylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, methyl amyl ketone, and diethylene glycol ethyl methyl ether.

  In the photosensitive resin composition of this invention, it is preferable that the component except a solvent is 5 mass%-40 mass%, More preferably, a solvent is mix | blended so that it may exist in the range of 10 mass%-30 mass%. . Thereby, it can be set as the viscosity suitable for application | coating.

(Additive)
Examples of the additive used in the present invention include an antistatic agent, a storage stabilizer, an antifoaming agent, a polymerization inhibitor, a plasticizer, a leveling agent, and a dispersing agent.

  Among these, examples of the plasticizer that can be used include dibutyl phthalate, dioctyl phthalate, and tricresyl. Examples of the antifoaming agent and leveling agent include silicon-based, fluorine-based, and acrylic compounds.

B. Next, the color filter of the present invention will be described. The color filter of this invention has a cured film formed by hardening | curing the photosensitive resin composition for color filters as described above.

  FIG. 1 is a schematic sectional view showing an example of the color filter of the present invention. As illustrated in FIG. 1, the color filter 1 includes a substrate 2, a black matrix 3 formed in a pattern on the substrate 2, and a colored layer 4 formed on the substrate 2 and the black matrix 3. The black matrix 3 and / or the colored layer 4 is a cured film in the present invention.

  In the present invention, when a black matrix in a color filter is formed using a photosensitive resin composition for a color filter having high sensitivity and excellent curability, a black matrix having a high light shielding rate and a high definition can be obtained. This makes it possible to obtain a high-quality color filter.

  Further, in the present invention, when a colored layer in a color filter is formed using a photosensitive resin composition for a color filter having high sensitivity and excellent curability, a high-definition colored layer can be obtained. A high-quality color filter can be obtained.

  The color filter of the present invention usually has a substrate, a black matrix formed on the substrate, and a colored layer formed on the substrate and the black matrix. Hereinafter, each configuration of the color filter of the present invention will be described.

1. Black Matrix First, the black matrix used in the color filter of the present invention will be described. The black matrix in the present invention is formed by curing the above-described color filter photosensitive resin composition.

  In the present invention, the black matrix can be formed in a pattern by applying the photosensitive resin composition for a color filter onto a substrate described later, drying, exposing and developing.

The method for applying the photosensitive resin composition is not particularly limited, and examples thereof include a spray coating method, a dip coating method, a bar coating method, a roll coating method, and a spin coating method.
The thickness of the coating film is appropriately controlled by adjusting the coating method, the solid content concentration, the viscosity, and the like of the photosensitive resin composition.
After the photosensitive resin composition is applied, the coating film is dried to remove the solvent. For example, it can be dried by heating the coating film using a hot plate or oven.

Next, the coating film is exposed through a mask having a predetermined pattern, and a binder resin or a compound having an ethylenically unsaturated double bond is photopolymerized to form a cured film of the photosensitive resin composition.
Examples of radiation used for exposure include ultraviolet rays such as low-pressure mercury lamps, high-pressure mercury lamps, and metal halide lamps, and electron beams. The exposure amount is appropriately adjusted depending on the light source used, the thickness of the coating film, and the like.
Moreover, in order to promote a polymerization reaction after exposure, you may heat-process. The heating conditions are appropriately selected depending on the blending ratio of each component in the photosensitive resin composition, the thickness of the coating film, and the like.

After the exposure, development is performed using a developer, and a non-exposed portion is dissolved and removed to form a cured film with a desired pattern.
As the developer, a solution in which an alkali is dissolved in water or a water-soluble solvent is usually used. An appropriate amount of a surfactant or the like may be added to the alkaline solution.
Further, a general method can be adopted as the developing method. The development conditions may be general conditions.
After development, the developer is usually washed and the cured film of the photosensitive resin composition is dried.

  Moreover, you may heat-process in order to fully harden a cured film after image development. The heating conditions are not particularly limited and are appropriately selected according to the use of the cured film.

  In addition, the photosensitive resin composition for color filters used for formation of a black matrix uses a black colorant. Since the photosensitive resin composition for a color filter containing such a black colorant has been described in detail in the section “A. Photosensitive resin composition for a color filter”, description thereof is omitted here.

2. Colored layer The colored layer used in the present invention is usually composed of a red pattern, a green pattern, and a blue pattern, and each colored pattern is regularly arranged. The arrangement of each colored pattern is not particularly limited, and examples thereof include a stripe type, a mosaic type, a triangle type, and a four pixel arrangement type.

  The method for forming such a colored layer can be the same as the method described in the section of the black matrix, and will not be described here.

  In addition, the photosensitive resin composition for color filters used for formation of a colored layer shall use a chromatic colorant. Since the photosensitive resin composition for color filters containing such a chromatic colorant has been described in detail in the above section “A. Photosensitive resin composition for color filters”, description thereof is omitted here. .

3. Substrate The substrate used in the present invention can be the same as that generally used as a substrate for a color filter. For example, a glass substrate or a plastic substrate is used. Specifically, a glass substrate containing alkali-free glass, soda lime glass, or the like, or a transparent plastic substrate such as polyimide or methacrylic acid resin can be used.

4). Others The color filter of the present invention may be one in which, for example, an overcoat layer, a transparent electrode layer, an alignment film, a columnar spacer, or the like is formed in addition to the substrate, the black matrix, and the colored layer.

  The present invention is not limited to the above embodiment. The above-described embodiment is an exemplification, and the present invention has substantially the same configuration as the technical idea described in the claims of the present invention, and any device that exhibits the same function and effect is the present invention. It is included in the technical scope of the invention.

  The following examples illustrate the present invention more specifically.

[Example 1]
Each component of carbon black, a dispersant, a binder resin, a compound having an ethylenically unsaturated double bond, an initiator, a sensitizer, an additive, and a solvent are blended as shown in Table 3 below, and the photosensitive material for color filters A functional resin composition was prepared. Each component is as follows.
Carbon black: Printex 200 (manufactured by Tegusa Japan Co., Ltd.)
・ Dispersant: Ajisper PB82 (Ajinomoto Fine Techno Co., Ltd.)
Binder resin (epoxy acrylate resin having a fluorene structure): INR-19P (manufactured by Nagase ChemteX Corporation)
Compound having an ethylenically unsaturated double bond: a mixture of dipentaerythritol penta (meth) acrylate and dipentaerythritol hexa (meth) acrylate Photoinitiator A: 4,4′-bis (dimethylamino) benzophenone Structural formula (9)

・光重合開始剤Ｂ（イミダゾール２量体）：下記構造式（１０）

Photopolymerization initiator B (imidazole dimer): Structural formula (10) below

・光重合開始剤Ｃ（オキシムエステル系化合物）：下記構造式（５）

Photopolymerization initiator C (oxime ester compound): Structural formula (5) below

・増感剤Ａ（多官能第２級チオール化合物）：下記構造式（１）

Sensitizer A (polyfunctional secondary thiol compound): Structural formula (1) below

Additive A: Organosilane silane coupling agent Additive B: Fluorosurfactant Solvent A: Methoxypropyl acetate Solvent B: Diethylene glycol ethyl methyl ether

[Example 2]
A photosensitive resin composition for a color filter was obtained in the same manner as in Example 1 except that the sensitizer A was changed to the sensitizer B represented by the following structural formula (2).
Sensitizer B (polyfunctional secondary thiol compound): Structural formula (2) below

[Example 3]
A photosensitive resin composition for a color filter was obtained in the same manner as in Example 1 except that the sensitizer A was changed to the sensitizer C represented by the following structural formula (3).
Sensitizer C (polyfunctional secondary thiol compound): Structural formula (3) below

[Example 4]
A photosensitive resin composition for a color filter was obtained in the same manner as in Example 1 except that the sensitizer A was changed to the sensitizer D shown in the following structural formula (4).
Sensitizer D (polyfunctional secondary thiol compound): Structural formula (4) below

[Comparative Example 1]
A photosensitive resin composition for a color filter was obtained in the same manner as in Example 1 except that the sensitizer A was changed to the sensitizer E represented by the following structural formula (11).
Sensitizer E (polyfunctional primary thiol compound): Structural formula (11) below

[Evaluation]
About the photosensitive resin composition for color filters of Examples 1-4 and Comparative Example 1, storage stability was evaluated as shown below.
First, about the photosensitive resin composition for color filters of Examples 1 to 4 and Comparative Example 1, two types each prepared immediately after manufacture and one after storage for 20 hours at 40 ° C. were used. A black matrix was formed. A method for forming the black matrix is described below.
(Formation of black matrix)
The photosensitive resin composition for color filters was applied to a glass substrate with a spin coater, heated on a hot plate at 90 ° C. for 3 minutes, and dried. Next, the coated film was exposed with a high-pressure mercury lamp through a photomask. Thereafter, the film was developed with a developer having a temperature of 23 ° C. and a KOH concentration of 0.05%, and further post-baked by heating in an oven at 230 ° C. for 30 minutes.

(result)
The plate making performance of each black matrix was compared. The results are shown in Table 3. In addition, when the edge of the formed pattern is jagged due to chipping or distortion (hereinafter referred to as “billing”), or when there is a poor adhesion with the substrate, ×, the adhesion with the substrate or with the substrate. When almost no defect was found, it was indicated as “◯”. Moreover, the formed pattern was observed with the semiconductor inspection microscope MX50 made from OLIMPUS.

  From the results of Table 3, in Examples 1 to 4, plate making performance equivalent to that before storage was exhibited even after storage at 40 ° C. for 20 hours. Further, in Examples 3 and 4, no wobbling and poor adhesion to the substrate were observed, and plate making performance was more excellent than in Examples 1 and 2. On the other hand, about the comparative example 1, before preservation | save, the plate-making property substantially equivalent to Examples 1-4 was shown, but after 40 degreeC 20-hour preservation | save, the lack of the pattern by the wrinkle of a pattern or the adhesion defect is recognized. It was. That is, it was confirmed that Examples 1-4 were excellent in storage stability.

It is a schematic sectional drawing which shows an example of the color filter of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Color filter 2 ... Board | substrate 3 ... Black matrix 4 ... Colored layer

Claims (6)

  Containing a binder resin, a compound having an ethylenically unsaturated double bond, a colorant, a photopolymerization initiator containing an imidazole dimer, and a sensitizer containing a polyfunctional secondary thiol compound. A photosensitive resin composition for a color filter.   The photosensitive resin composition for a color filter according to claim 1, wherein the photopolymerization initiator further contains an oxime ester compound.   The photosensitive resin composition for a color filter according to claim 1, wherein the colorant is a black colorant.   The photosensitive resin composition for a color filter according to any one of claims 1 to 3, wherein the binder resin includes an epoxy acrylate resin having a fluorene structure.   The photosensitive resin composition for a color filter according to claim 1, wherein the colorant is a chromatic colorant.   A color filter comprising a cured film formed by curing the photosensitive resin composition for a color filter according to any one of claims 1 to 5.

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