JP4964862B2 - Photosensitive resin composition and color filter using the photosensitive resin composition - Google Patents

Description

The present invention relates to a photosensitive resin composition and a color filter using the photosensitive resin composition, in particular, excellent in development speed and photosensitivity, and a cured coating film has heat resistance and adhesion to a substrate. The present invention relates to a photosensitive resin composition having excellent properties, hardness, solvent resistance, and alkali resistance, and a color filter using the photosensitive resin composition.

  In recent years, a high level of display quality has been demanded particularly for viewing angle characteristics. As a result of optical design of the entire liquid crystal display device, the colored layer of the color filter, the counter substrate support layer, and the cell gap control raising In some cases, the thickness direction retardation value of at least one of the layers and the retardation layer is 3 to -30 nm, that is, the birefringence requires a negative value from about 0.

  On the other hand, the colored layer contains a polymer having a planar structure group in the side chain, or the colored layer contains birefringence-reducing particles having birefringence opposite to that of the polymer. Attempts have been made to reduce the amount of retardation that the filter has (see, for example, Patent Documents 1 and 2).

  In addition, by adding a retardation adjusting agent to the colored layer and having a different retardation for each subpixel, without providing a polymerization type liquid crystal layer separately from the color filter layer, without changing the thickness for each subpixel, Attempts have been made to make the viewing angle compensation of the black state of the liquid crystal display device possible in almost all visible light wavelengths (see, for example, Patent Documents 3, 4, and 5).

  Further, the thickness direction retardation values (respectively Rth (R), Rth (G), and Rth (B)) of the red, green, and blue colored pixels of the color filter are used for the wavelength dispersion of the liquid crystal material and the retardation film. In addition, a method of improving oblique visibility by setting Rth (R)> Rth (G)> Rth (B) or Rth (R) <Rth (G) <Rth (B) has been proposed (for example, And Patent Document 6).

  However, the thickness direction retardation value of the color filter varies greatly depending on the type of pigment used, and the thickness direction retardation value depends on the fineness and dispersion of the pigment or the matrix resin (for example, acrylic resin or cardo resin). The present inventors have found that the thickness direction retardation value can be increased in the positive direction, but shifting from zero to the negative direction is based on the planar structure based on these side chains. In the method of containing the polymer having bismuth and the birefringence reducing particles, a sufficient effect cannot be obtained, and the above-described problem cannot be solved.

  On the other hand, the above-described styrene-containing polymer composition is known to have negative birefringence (see, for example, Non-Patent Document 1), and is suitably used as a negative birefringent retardation film material. Yes. Accordingly, a styrene-containing polymer composition as a birefringence adjusting agent is used as a material for forming at least one of the coloring layer of the color filter for liquid crystal display, the counter substrate supporting layer, the cell gap control raising layer and the retardation layer. If used, it is expected that the above problems can be solved. However, since the retardation of the color filter is relatively small compared to other members used in the liquid crystal display device, such an attempt has not been made so far. That is, for example, a method for reducing the thickness direction retardation value by adding a styrene-containing polymerization composition to an alkali-developable photosensitive resin composition has been hardly studied.

  Since the styrene-containing polymer composition is excellent in transparency and heat resistance, for example, a colored layer of a color filter used in a liquid crystal display, an electronic paper display, and an electroluminescence panel, or a forming material such as a counter substrate carrying layer Can be used. In addition, it is possible to impart developability and photocurability by copolymerizing with alkali-soluble monomers such as aromatic / non-aromatic polycarboxylic acid-containing monomers and polymerizable bond-containing monomers. It has an excellent function as a polymerizable composition.

  In recent years, there has been a demand for higher image quality, lower power consumption, and lower prices for thin display devices such as liquid crystal displays. Color filters are compatible with various liquid crystal display modes with sufficient color purity, brightness, and contrast. Photosensitive resin composition capable of patterning a colored layer having a fine pattern, a counter substrate carrying layer, a cell gap control raising layer, and a retardation layer with high accuracy and low cost while exhibiting a high birefringence Is desired.

In addition, when a large amount of the conventional styrene-containing polymerization composition is blended, there is a problem that the storage stability of the photosensitive resin composition is deteriorated. Furthermore, the alkali developability of the photosensitive resin composition deteriorates, the development speed cannot be adjusted appropriately, the development time becomes longer, and conversely, the development speed is too high and the coating film is easily peeled off from the substrate. Therefore, there is a limit to the amount of the styrene-containing polymer composition added, and the effect as a birefringence modifier could not be fully exhibited.
JP 2000-136253 A JP 2000-187114 A JP 2008-20905 A JP 2008-40486 A JP 2008-145868 A JP 2007-212603 A "Tosoh Research and Technical Report Vol. 48 (2004)"

The present invention has been made in view of the above circumstances, and is excellent in long-term storage stability, development speed and photosensitivity, and further, the coating film after curing by light irradiation and / or baking has a thickness direction retardation value of 2 to -12 nm. Rth, heat developability, adhesion to substrate, hardness, solvent resistance, alkali resistance, alkali development type photosensitive colored layer , counter substrate carrying layer, cell gap control raised layer, and position It aims at providing the photosensitive resin composition for forming a phase difference layer , and the color filter using this photosensitive resin composition .

In order to solve the above problems, a first aspect of the present invention is obtained by copolymerizing styrene and an unsaturated carboxylic acid-containing monomer, has a weight average molecular weight of 30000 or less, and a solid content acid value of 10 to 10. 150 mgKOH / g and a styrene content of 75 mol% or more, a photopolymerizable monomer, a photopolymerization initiator, a solid content acid value of 20 to 180 mgKOH / g, and a double bond A photosensitive resin composition comprising an acrylic resin having an equivalent weight of 100 or more, and an organic pigment further dispersed in the photosensitive resin composition having a solid content of 3 to 60% by mass in the solid content. And the thickness direction phase difference after hardening the coating film of this photosensitive resin composition is 2-12 nm, The photosensitive resin composition for color filters characterized by the above-mentioned is provided.

A second aspect of the present invention is a color filter comprising a substrate and a colored layer formed on the substrate, wherein the colored layer is coated with a photosensitive resin composition in which the organic pigment is dispersed , Provided is a color filter, which is a cured film obtained by development , wherein the retardation value Rth in the thickness direction of the colored layer represented by the following formula is 2 to -12 nm.

Rth = {(Nx + Ny) / 2−Nz} × d
(In the formula, Nx represents the refractive index in the x direction in the plane of the colored pixel layer, Ny represents the refractive index in the y direction in the plane of the colored pixel layer, and Nz represents the refractive index in the thickness direction of the colored pixel layer. .)
According to a third aspect of the present invention, there is provided a substrate, a colored layer formed on the substrate, a counter substrate carrying layer formed on the substrate on which the colored layer is formed, a cell gap control raising layer, And a color filter comprising at least one selected from the group consisting of retardation layers, at least one selected from the group consisting of the counter substrate carrying layer, the cell gap control raising layer, and the retardation layer The present invention provides a color filter characterized by being a cured film obtained by applying and developing the photosensitive resin composition described above.

In such a color filter, the colored layer can be used in the color filter according to the second aspect.

  According to the present invention, there are provided a photosensitive composition having long-term storage stability, high development speed, and excellent photosensitivity, and a color filter polymerization composition contained therein. In addition, in the photosensitive composition, the coating film after being cured by light irradiation and / or baking has a thickness direction retardation value Rth of 2 to -12 nm, heat resistance, adhesion to the substrate, hardness, Excellent solvent resistance and alkali resistance. Therefore, this photosensitive composition is suitable for forming an alkali development type photosensitive color filter, a counter substrate carrying layer, a cell gap control raising layer, and a retardation layer.

  Hereinafter, embodiments of the present invention will be described.

  The present inventors have intensively studied a photosensitive composition used for forming color filter components such as a color filter coloring layer, a counter substrate carrying layer, a cell gap control raising layer, and a retardation layer. As a result, it has been found that a photosensitive composition containing a polymerization composition obtained by copolymerizing styrene and an unsaturated carboxylic acid-containing monomer exhibits excellent performance in forming the color filter component. . That is, such a photosensitive composition has excellent developability, long-term storage stability, and development speed, and the coating film after being cured by light irradiation and / or baking has a thickness of 2 to -12 nm. It has a directional retardation value Rth and is excellent in heat resistance, adhesion to a substrate, hardness, solvent resistance, and alkali resistance, and can solve all the problems of the conventional techniques described above.

  The polymerization composition according to the first embodiment of the present invention is obtained by reacting styrene with an unsaturated carboxylic acid-containing monomer, and has a weight average molecular weight of 30000 or less, and a solid content acid value of 10 to 150 mgKOH / g. And a styrene content of 75 mol% or more. Such a polymerization composition is prepared by a method well known to those skilled in the art, such as radical polymerization of an ethylenically unsaturated group of styrene and an ethylenically unsaturated group of an unsaturated carboxylic acid-containing monomer in an organic solvent. It can be obtained by reacting.

  Thus, the photosensitive resin composition prepared by blending the polymerization composition in which the weight average molecular weight is 30000 or less and the solid content acid value is controlled to 10 to 150 mgKOH / g is a conventional photosensitive resin composition. It is possible to solve the problems and have the effect of the styrene-containing polymerization composition sufficiently exhibited. That is, the alkali developability of the photosensitive resin composition, which is a problem of the photosensitive resin composition including a styrene-containing polymerization composition having a weight average molecular weight exceeding 30000 and a solid content acid value of 10 to 150 mgKOH / g. It does not worsen, the development speed cannot be adjusted properly, the development time is prolonged, and conversely, the development speed is too high and the coating film is easily peeled off from the substrate.

  In addition, the polymerization composition according to the first embodiment of the present invention has a styrene content of 75 mol% or more, thereby making it possible to develop the negative birefringence of a conventional styrene resin, and alkali development. 3 to +30 nm caused by the influence of pigments, dispersants, and other binder resins, which occurred in the type photosensitive color filter, the counter substrate carrying layer, the cell gap control raised layer, and the retardation layer It is possible to cancel the unnecessary positive thickness direction retardation value Rth to a certain extent and further reduce it to a negative value. Accordingly, it is possible to provide a liquid crystal display device having a thickness direction retardation value of 2 to -12 nm which is originally desired and having excellent display characteristics even when viewed obliquely.

  When the styrene content is less than 75 mol%, the positive thickness direction retardation value Rth of 3 to +30 nm cannot be sufficiently canceled, and it becomes difficult to exhibit the function as a birefringence adjusting agent.

  Examples of the unsaturated carboxylic acid-containing monomer used for producing the polymerization composition according to the first embodiment of the present invention described above include acrylic acid, methacrylic acid, maleic acid, monoalkylmaleic acid, fumaric acid, and monoalkyl. Examples include fumaric acid, itaconic acid, monoalkyl itaconic acid, crotonic acid and the like. Among them, mention may be made of acrylic acid and methacrylic acid.

  A photosensitive resin composition according to the second embodiment of the present invention contains the above-described polymerization composition, a photopolymerizable monomer, a photopolymerization initiator, and an acrylic resin, and the polymerization composition is photosensitive. Having a content of 3 to 60% in the solid content of the conductive resin composition. Further, as other components, a photosensitizer, a non-photosensitive resin and / or a photosensitive resin, a pigment, a dispersant, a surfactant, a polyfunctional thiol, a storage stabilizer, an adhesion improver, and a solvent may be included. I can do it.

  According to such a photosensitive resin composition, since it contains 3 to 60% by mass of the above-described polymerization composition in the solid content of the photosensitive resin composition, the polymerization composition has heat resistance and adhesion to the substrate. Properties having excellent properties, hardness, solvent resistance, alkali resistance, and birefringence can be sufficiently exhibited. That is, since these photosensitive resin compositions have been imparted with properties such as the above-described long-term storage stability and development speed of the polymerization composition, an alkali development type photosensitive color filter coloring layer, counter substrate It can be suitably used for forming a support layer, a cell gap control raising layer, and a retardation layer.

  In the photosensitive resin composition according to the second aspect of the present invention, by setting the acid value of the acrylic resin to 20 to 180 mgKOH / g, the development speed cannot be adjusted appropriately, and the development time becomes longer. It is possible to adjust the alkali developability of the photosensitive resin composition to an optimum state without causing a problem that the developing speed is too high and the coating film is easily peeled off from the substrate.

  In addition, by setting the double bond equivalent of the acrylic resin to preferably 100 or more, more preferably 100 to 2000, the sensitivity of the photosensitive resin composition is insufficient, and the exposure time necessary for sufficient curing is increased. The exposure sensitivity of the photosensitive resin composition can be sufficiently maintained without causing a problem that the productivity deteriorates. Moreover, the photosensitive resin composition can contain a pigment and a dispersing agent further.

  The photosensitive resin composition according to the second embodiment of the present invention is used to form at least one of a color filter coloring layer, a counter substrate support layer, and a retardation layer. For curing the photosensitive resin composition, any of curing methods such as UV exposure and deep UV exposure may be used.

  The styrene containing polymerization composition used for the photosensitive resin composition may be used individually by 1 type, and can also be used in combination of 2 or more type.

  Other components of the photosensitive resin composition according to the second embodiment of the present invention excluding the polymerization composition will be described below.

(Acrylic resin)
Examples of the acrylic resin include the following.

  Acrylic resin is, for example, (meth) acrylic acid; methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, t-butyl (meth) acrylate pencil Alkyl (meth) acrylates such as (meth) acrylate and lauryl (meth) acrylate; hydroxyl-containing (meth) acrylates such as hydroxyethyl (meth) acrylate and hydroxypropyl (meth) acrylate; ethoxyethyl (meth) acrylate and glycidyl (meta ) Ether group-containing (meth) acrylates such as acrylates; and alicyclic (meth) acrylates such as cyclohexyl (meth) acrylates, isobornyl (meth) acrylates, dicyclopentenyl (meth) acrylates, etc. Coalescence, and the like.

In addition, the monomer mentioned above can be used individually or in combination of 2 or more types. Further, it may be a copolymer of a compound such as styrene, cyclohexylmaleimide, and phenylmaleimide copolymerizable with these monomers.
Further, for example, a copolymer obtained by copolymerizing a carboxylic acid having an ethylenically unsaturated group such as (meth) acrylic acid, and a compound containing an epoxy group and an unsaturated double bond such as glycidyl methacrylate are obtained. Reacting or adding a carboxylic acid-containing compound such as (meth) acrylic acid to a polymer of an epoxy group-containing (meth) acrylate such as glycidyl methacrylate or a copolymer thereof with other (meth) acrylate Thus, a resin having photosensitivity can be obtained.

  Furthermore, a resin having photosensitivity can also be obtained by reacting a polymer having a hydroxyl group of a monomer such as hydroxyethyl methacrylate with a compound having an isocyanate group such as methacryloyloxyethyl isocyanate and an ethylenically unsaturated group. Can be obtained.

  In addition, as described above, a copolymer such as hydroxyethyl methacrylate having a plurality of hydroxyl groups and a polybasic acid anhydride are reacted to introduce a carboxyl group into the copolymer to obtain a resin having a carboxyl group. I can do it. The manufacturing method is not limited to the method described above.

Examples of acid anhydrides used in the above reaction include, for example, malonic acid anhydride, succinic acid anhydride, maleic acid anhydride, itaconic acid anhydride, phthalic acid anhydride, tetrahydrophthalic acid anhydride, hexahydrophthalic acid anhydride , Methyltetrahydrophthalic anhydride, trimellitic anhydride and the like.
It is preferable that the solid content acid value of the acrylic resin described above is 20 to 180 mgKOH / g. When the acid value is less than 20 mgKOH / g, the development speed of the photosensitive resin composition is too slow, and the time required for development increases, and the productivity tends to be inferior. On the other hand, when the solid content acid value is larger than 180 mgKOH / g, on the contrary, the development speed is too high, and there is a tendency that pattern peeling or pattern chipping after development occurs.

  Furthermore, when the said acrylic resin has photosensitivity, it is preferable that the double bond equivalent of this acrylic resin is 100 or more, More preferably, it is 100-2000, Most preferably, it is 100-1000. When the double bond equivalent exceeds 2000, it may be difficult to obtain sufficient photocurability.

(Photopolymerizable monomer)
Examples of photopolymerizable monomers include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, cyclohexyl (meth) acrylate, polyethylene glycol di (meth) acrylate, pentaerythritol tri (meth) acrylate, trimethylol Various acrylic and methacrylic acid esters such as propane tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, tricyclodecanyl (meth) acrylate, melamine (meth) acrylate, epoxy (meth) acrylate, (meth) Examples include acrylic acid, styrene, vinyl acetate, (meth) acrylamide, N-hydroxymethyl (meth) acrylamide, and acrylonitrile.

  Moreover, it is preferable to use the polyfunctional urethane acrylate which has the (meth) acryloyl group obtained by making polyfunctional isocyanate react with the (meth) acrylate which has a hydroxyl group. The combination of the (meth) acrylate having a hydroxyl group and the polyfunctional isocyanate is arbitrary and is not particularly limited. Moreover, one type of polyfunctional urethane acrylate may be used alone, or two or more types may be used in combination.

(Photopolymerization initiator)
Examples of the photopolymerization initiator include 4-phenoxydichloroacetophenone, 4-t-butyl-dichloroacetophenone, diethoxyacetophenone, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, 1- Acetophenone compounds such as hydroxycyclohexyl phenyl ketone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzyl Benzoin compounds such as dimethyl ketal, benzophenone, benzoylbenzoic acid, methyl benzoylbenzoate, 4-phenylbenzophenone, hydroxybenzophenone, acrylated benzophenone, 4-benzoyl-4 ' Benzophenone compounds such as methyldiphenyl sulfide, thioxanthone compounds such as thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, isopropylthioxanthone, 2,4-diisopropylthioxanthone, 2,4,6- Trichloro-s-triazine, 2-phenyl-4,6-bis (trichloromethyl) -s-triazine, 2- (p-methoxyphenyl) -4,6-bis (trichloromethyl) -s-triazine, 2- ( p-tolyl) -4,6-bis (trichloromethyl) -s-triazine, 2-pienyl-4,6-bis (trichloromethyl) -s-triazine, 2,4-bis (trichloromethyl) -6-styryl s-triazine, 2- (naphth-1-yl) -4,6-bis (trichloromethyl) -s-tri Gin, 2- (4-methoxy-naphth-1-yl) -4,6-bis (trichloromethyl) -s-triazine, 2,4-trichloromethyl- (piperonyl) -6-triazine, 2,4-trichloro Triazine compounds such as methyl (4′-methoxystyryl) -6-triazine, 1,2-octanedione, 1- [4- (phenylthio)-, 2- (O-benzoyloxime)], O- (acetyl) Oxime ester compounds such as -N- (1-phenyl-2-oxo-2- (4'-methoxy-naphthyl) ethylidene) hydroxylamine, bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide, 2, Phosphine compounds such as 4,6-trimethylbenzoyldiphenylphosphine oxide, 9,10-phenanthrenequinone, camphor Quinones, quinone-based compounds such as ethyl anthraquinone, borate compounds, carbazole compounds, imidazole compounds, titanocene compounds, and the like.

  These can be used singly or in combination of two or more.

(Photosensitizer)
It is preferable to use a polymerization initiator and a photosensitizer in combination. As photosensitizer, α-acyloxy ester, acylphosphine oxide, methylphenylglyoxylate, benzyl, 9,10-phenanthrenequinone, camphorquinone, ethylanthraquinone, 4,4′-diethylisophthalophenone 3,3 ′, 4,4′-tetra (t-butylperoxycarbonyl) benzophenone, 4,4′-diethylaminobenzophenone, and the like can also be used in combination.

  The sensitizer can contain 0.1 to 60 parts by mass with respect to 100 parts by mass of the photopolymerization initiator.

(Non-photosensitive resin and / or photosensitive resin)
The photosensitive resin composition according to the second embodiment of the present invention preferably has a transmittance of 80% or more, more preferably 95% or more in the entire wavelength region of 400 to 700 nm in the visible light region. A transparent resin and / or a photosensitive transparent resin can be used in combination.

Transparent resins include thermoplastic resins, thermosetting resins, and photosensitive resins. Examples of thermoplastic resins include butyral resin, styrene-maleic acid copolymer, chlorinated polyethylene, chlorinated polypropylene, and poly Vinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyurethane resin, polyester resin, acrylic resin, alkyd resin, polystyrene resin, polyamide resin, rubber resin, cyclized rubber resin, celluloses, polybutadiene , Polyethylene, polypropylene, polyimide resin and the like. Examples of the thermosetting resin include epoxy resins, benzoguanamine resins, rosin-modified maleic acid resins, rosin-modified fumaric acid resins, melamine resins, urea resins, and phenol resins. As the thermosetting resin, a resin obtained by reacting the following melamine resin with an isocyanate group-containing compound may be used. Examples of the melamine resin include compounds having the structural formula (I) shown below and multimers thereof.

(Wherein R ^{1 to} R ⁶ each represent a hydrogen atom or CH ₂ OR (R represents a hydrogen atom or an alkyl group, and R ^{1 to} R ⁶ may be the same or different). , R ^{1 to} R ⁶ may be the same or different.
Two or more homopolymers or copolymers may be used in combination. In addition to the above, compounds having a 1,3,5-triazine ring, for example, those described in JP-A No. 2001-166144 can be used. In addition, compounds represented by the structural formula (II) shown below are also preferably used.

(R ⁷ to R ¹⁴ are each independently a hydrogen atom, an alkyl group, an alkenyl group, an aryl group or a heterocyclic group, and particularly preferably a hydrogen atom.)
As an example of the compound containing an isocyanate group used for the above reaction, various known aromatic, aliphatic or alicyclic isocyanates can be used.

  For example, 1,5-naphthylene diisocyanate, 4,4′-diphenylmethane diisocyanate, 4,4′-diphenyldimethylmethane diisocyanate, 4,4′-dibenzyl isocyanate, dialkyldiphenylmethane diisocyanate, tetraalkyldiphenylmethane diisocyanate, 1,3- Aromatic polyisocyanates such as phenylene diisocyanate, 1,4-phenylene diisocyanate, tolylene diisocyanate, xylylene diisocyanate, m-tetramethylxylylene diisocyanate, butane-1,4-diisocyanate, hexamethylene diisocyanate, isopropylene diisocyanate, methylene diisocyanate 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethyl Aliphatic polyisocyanates such as hexamethylene diisocyanate, cyclohexane-1,4-diisocyanate, isophorone diisocyanate, lysine diisocyanate, dicyclohexylmethane-4,4′-diisocyanate, 1,3-bis (isocyanatemethyl) cyclohexane, methylcyclohexane diisocyanate, etc. Examples thereof include alicyclic polyisocyanate and dimer isocyanate obtained by converting a carboxyl group of dimer acid into an isocyanate group.

  Moreover, when giving photosensitivity to this thermosetting resin, the compound containing an isocyanate group and a double bond group can be used suitably, 2-Athacryloyloxyethyl isocyanate, 2-methacryloyl Examples thereof include oxyethyl isocyanate, 1,1- (bisacryloyloxymethyl) ethyl isocyanate, and the like.

  Examples of acid anhydrides used in the above reaction include malonic acid anhydride, succinic acid anhydride, maleic acid anhydride, itaconic acid anhydride, phthalic acid anhydride, hexahydrophthalic acid anhydride, tetrahydrophthalic acid anhydride And methyltetrahydrophthalic anhydride.

  In the thermosetting resin, the acid value is required to be 3 to 60 mgKOH / g in terms of solid content, and more preferably 20 to 50 mgKOH / g. Therefore, the addition reaction of the acid anhydride is quantitatively reacted so that the acid value falls within this range.

  If the acid value of the thermosetting resin is less than 3 mgKOH / g, there is a risk of developing failure in alkali development. If the acid value is greater than 60 mgKOH / g, the surface of the exposed part is eroded by the developer in alkali development. In addition, problems such as deterioration of long-term storage stability of the photosensitive resin composition are likely to occur. The thermosetting resin described above can be prepared by any of the following methods.

(1) A method in which a compound containing a melamine resin and an isocyanate group is mixed and reacted under heating,
(2) A method in which a compound containing a melamine resin and an isocyanate group is mixed and reacted under heating, and further an acid anhydride is mixed and reacted under heating.

  (3) A method in which a melamine resin and an acid anhydride are mixed and reacted under heating.

  Moreover, you may include the process of distilling off a low boiling alcohol compound using an evaporator etc. as a pretreatment, and the process of carrying out solvent substitution with the solvent suitable for the photosensitive resin composition.

  In general, thermosetting resins such as melamine resins have high heat reactivity and generally poor long-term storage stability, and thus it has been difficult to use them in a large amount in a photosensitive resin composition. However, in the above-mentioned thermosetting resin, some of the thermoreactive groups present in the melamine resin skeleton are used for the reaction with an isocyanate group-containing compound or acid anhydride. The properties are moderately lowered, and the effect of improving the long-term storage stability of the photosensitive resin composition can be obtained. Further, as a result of the reaction with the isocyanate group-containing compound or acid anhydride, the polymer chain of the melamine resin becomes longer and the free movement of the melamine resin skeleton is constrained, so that the storage stability is improved. is there.

  Melamine resin can be used as a retardation adjusting agent because it tends to increase retardation as a color filter coloring composition.

  The reaction with the isocyanate group-containing compound or acid anhydride makes it possible to impart alkali developability and / or photosensitivity necessary for the alkali development type photosensitive resin composition to the melamine resin. By providing alkali developability and / or photosensitivity in this way, adhesion with the substrate is improved, and a photosensitive resin composition having a good process margin that does not cause problems during the development process is realized. Can do.

  Furthermore, by including the thermosetting resin in the photosensitive resin composition, not only can the cured coating film be provided with sufficient heat resistance and hardness, but also solvent resistance and alkali resistance functions. can do.

  In addition, by containing an appropriate amount of the thermosetting resin, elution of ionic impurities contained in pigments and other fine particles and / or contained in the manufacturing process can be reduced, and electrical characteristics can be improved. It becomes possible to do. That is, the thermosetting resin is contained in the photosensitive resin composition when it is baked and cured to form a color filter coloring layer, a counter substrate carrying layer, a cell gap control raising layer, and a retardation layer. It reacts and confines pigments and other fine particles in the polymer network, so that elution of ionic impurities can be suppressed.

  Moreover, by adding an appropriate amount of a thermosetting resin, the aromatic ring of the thermosetting resin functions electronically, and the electrical characteristics of the cured film can be adjusted. As a result, it is possible to provide a liquid crystal display device having excellent electrical characteristics that is free from burn-in and color shift even when displayed for a long time.

(Pigment)
When the photosensitive resin composition layer is a colored layer of a color filter, it is necessary to further contain a pigment.

  Further, even in the case of a counter substrate carrying layer that is not a colored layer, a cell gap control raising layer, and a retardation layer, a pigment can be contained in order to impart light shielding properties. Known pigments can be used for the photosensitive resin composition for forming the colored layer and for imparting light shielding properties. The blending amount of the pigment is not particularly limited, but is preferably about 5 to 70% by mass, more preferably about 5 to 50% by mass with respect to 100% by mass of the total amount of the composition, More preferably, the content is about 20 to 50% by mass, and the remainder substantially consists of a resinous binder provided by the pigment carrier.

  Also, a plurality of pigments can be used in combination for spectral adjustment of the color filter. The pigment is preferably contained in a proportion of 5 to 70% by mass based on the total solid content of the colored composition (100% by mass).

  In combination with the organic pigment, an inorganic pigment may be used in combination in order to ensure good coatability, sensitivity, developability and the like while balancing saturation and lightness. Inorganic pigments include yellow lead, zinc yellow, red pepper (red iron oxide (III)), cadmium red, ultramarine, bitumen, chromium oxide green, cobalt green, and other metal oxide powders, metal sulfide powders, metal powders, etc. Can be mentioned. Furthermore, for color matching, a dye can be contained within a range that does not lower the heat resistance.

(Dispersant)
When the pigment is dispersed in the pigment carrier and the organic solvent, it is necessary to contain a dispersant and a surfactant for dispersing the pigment. Surfactants, pigment intermediates, dye intermediates, Solsperse, and the like are used as the dispersant, and have a pigment affinity part having a property of adsorbing to the pigment and a part compatible with the pigment carrier. It functions to adsorb to the pigment and stabilize the dispersion of the pigment on the pigment carrier.

  Specifically, polycarboxylic acid esters such as polyurethane and polyacrylate, unsaturated polyamide, polycarboxylic acid, polycarboxylic acid (partial) amine salt, polycarboxylic acid ammonium salt, polycarboxylic acid alkylamine salt, polysiloxane, long Oil-based dispersants such as chain polyaminoamide phosphates, hydroxyl group-containing polycarboxylic acid esters, their modified products, amides formed by the reaction of poly (lower alkyleneimines) and polyesters having free carboxyl groups, and salts thereof , (Meth) acrylic acid-styrene copolymer, (meth) acrylic acid- (meth) acrylic acid ester copolymer, styrene-maleic acid copolymer, polyvinyl alcohol, polyvinylpyrrolidone, and other water-soluble resins Molecular compound, polyester, modified polyacrylate , Ethylene oxide / propylene oxide addition compound, phosphate ester-based and the like are used, they can be used alone or in admixture of two or more.

  Although the addition amount of a dispersing agent is not specifically limited, It is preferable to set it as 1-10 mass% with respect to 100 mass% of compounding quantities of a pigment. Further, the coloring composition may be obtained by means of centrifugal separation, a sintered filter, a membrane filter, or the like, with coarse particles of 5 μm or more, preferably coarse particles of 1 μm or more, more preferably coarse particles of 0.5 μm or more and mixed dust. Is preferably removed.

(Surfactant)
Surfactants include polyoxyethylene alkyl ether sulfate, sodium dodecylbenzenesulfonate, alkali salt of styrene-acrylic acid copolymer, sodium alkylnaphthalenesulfonate, sodium alkyldiphenyletherdisulfonate, lauryl sulfate monoethanolamine, lauryl Anionic surfactants such as triethanolamine sulfate, ammonium lauryl sulfate, monoethanolamine stearate, sodium stearate, sodium lauryl sulfate, monoethanolamine of styrene-acrylic acid copolymer, polyoxyethylene alkyl ether phosphate; Polyoxyethylene oleyl ether, polyoxyethylene lauryl ether, polyoxyethylene nonylphenyl ether, polyoxyethylene Nonionic surfactants such as alkyl ether phosphates, polyoxyethylene sorbitan monostearate, and polyethylene glycol monolaurate; chaotic surfactants such as alkyl quaternary ammonium salts and their ethylene oxide adducts; alkyldimethylamino Examples include amphoteric surfactants such as alkylbetaines such as betaine acetate and alkylimidazolines, and these can be used alone or in admixture of two or more.

(Multifunctional thiol)
The photosensitive resin composition can contain a polyfunctional thiol that functions as a chain transfer agent. The polyfunctional thiol may be a compound having two or more thiol groups. For example, hexanedithiol, decanedithiol, 1,4-butanediol bisthiopropionate, 1,4-butanediol bisthioglycolate, ethylene Glycol bisthioglycolate, ethylene glycol bisthiopropionate, trimethylolpropane tristhioglycolate, trimethylolpropane tristhiopropionate, trimethylolpropane tris (3-mercaptobutyrate), pentaerythritol tetrakisthioglycolate, Pentaerythritol tetrakisthiopropionate, trimercaptopropionic acid tris (2-hydroxyethyl) isocyanurate, 1,4-dimethylmercaptobenzene, 2,4,6-trimercap -s- triazine, 2- (N, N- dibutylamino) -4,6-dimercapto -s- triazine.

  These polyfunctional thiols can be used alone or in combination. The polyfunctional thiol can be used in an amount of 0.2 to 150 parts by mass, preferably 0.2 to 100 parts by mass with respect to 100 parts by mass of the pigment in the coloring composition.

(Storage stabilizer)
The photosensitive resin composition can contain a storage stabilizer in order to stabilize the viscosity with time of the composition. Examples of the storage stabilizer include quaternary ammonium chlorides such as benzyltrimethyl chloride and diethylhydroxyamine, organic acids such as lactic acid and oxalic acid, and organic acids such as methyl ether, t-butylpyrocatechol, triethylphosphine, and triphenylphosphine. Examples thereof include phosphine and phosphite. The storage stabilizer can be contained in an amount of 0.1 to 10 parts by mass with respect to 100 parts by mass of the pigment in the colored composition.

(Adhesion improver)
In addition, the photosensitive resin composition may contain an adhesion improver such as a silane coupling agent in order to enhance the adhesion to the substrate. Examples of the silane coupling agent include vinyl silanes such as vinyltris (β-methoxyethoxy) silane, vinylethoxysilane, and vinyltrimethoxysilane, (meth) acrylsilanes such as γ-methacryloxypropyltrimethoxysilane, β- (3 , 4-epoxycyclohexyl) ethyltrimethoxysilane, β- (3,4-epoxycyclohexyl) methyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltriethoxysilane, β- (3,4-epoxycyclohexyl) ) Epoxysilanes such as methyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, N-β ( Aminoethyl) γ-aminopro Lutriethoxysilane, N-β (aminoethyl) γ-aminopropylmethyldiethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, N Examples include aminosilanes such as -phenyl-γ-aminopropyltriethoxysilane, thiosilanes such as γ-mercaptopropyltrimethoxysilane, and γ-mercaptopropyltriethoxysilane. The silane coupling agent can be contained in an amount of 0.01 to 100 parts by mass with respect to 100 parts by mass of the pigment in the coloring composition.

(solvent)
The photosensitive resin composition is mixed with a solvent such as water or an organic solvent in order to enable uniform coating on the substrate. When the composition of the present invention is a colored layer of a color filter, the solvent also has a function of uniformly dispersing the pigment. Examples of the solvent include cyclohexanone, ethyl cellosolve acetate, butyl cellosolve acetate, 1-methoxy-2-propyl acetate, diethylene glycol dimethyl ether, ethylbenzene, ethylene glycol diethyl ether, xylene, ethyl cellosolve, methyl-n amyl ketone, propylene glycol monomethyl ether, toluene, Examples include methyl ethyl ketone, ethyl acetate, methanol, ethanol, isopropyl alcohol, butanol, isobutyl ketone, petroleum solvent, and the like. These may be used alone or in combination. The solvent can be used in an amount of 800 to 4000 parts by mass, preferably 1000 to 2500 parts by mass with respect to 100 parts by mass of the pigment in the coloring composition.

[Method for Preparing Photosensitive Resin Composition]
The photosensitive resin composition can be prepared by a known method. For example, a photosensitive coloring composition containing a photopolymerizable monomer, a thermosetting resin, a pigment, a dispersant, and a solvent can be prepared by the following method.

  (1) A pigment composition prepared by mixing a pigment and a dispersant in advance in a photopolymerizable monomer and the thermosetting resin of the present invention, or a solution obtained by dissolving these in a solvent, is added and dispersed, and the remaining components Add.

  (2) A pigment and a dispersant are separately added and dispersed in a photopolymerizable monomer and the thermosetting resin of the present invention, or a solution in which these are dissolved in a solvent, and then the remaining components are added.

  (3) After the pigment is dispersed in the photopolymerizable monomer and the thermosetting resin of the present invention or a solution obtained by dissolving these in a solvent, a pigment dispersant is added, and the remaining components are added.

  (4) Prepare two types of photopolymerizable monomer and the thermosetting resin of the present invention, or a solution in which these are dissolved in a solvent, disperse the pigment and the dispersant separately in advance, and then mix these, Add ingredients. One of the pigment and the dispersant may be dispersed only in the solvent.

  Here, the dispersion of the pigment and the dispersant in the photopolymerizable monomer and the thermosetting resin of the present invention, or a solution in which these are dissolved in a solvent, is a three roll mill, a two roll mill, a sand mill, a kneader, a dissolver, a high speed. It can be performed using various dispersing devices such as a mixer, a homomixer, and an attritor. Moreover, in order to perform dispersion | distribution favorably, you may add and disperse | distribute various surfactants.

  In addition, when preparing a pigment composition by previously mixing a pigment and a dispersant, the powder pigment and the powder dispersant may be simply mixed, but (a) a kneader, a roll, an attritor, a super mill, etc. Mix mechanically with various pulverizers, (b) Disperse the pigment in the solvent, add a solution containing the dispersant, and adsorb the dispersant on the pigment surface. (C) Strong dissolving power such as sulfuric acid It is preferable to employ a mixing method in which the pigment and the dispersant are co-dissolved in the solvent that is held and then co-precipitated using a poor solvent such as water.

[Color filter]
Hereinafter, a method for forming a colored layer for a color filter will be described. A counter substrate carrying layer for uniformizing a cell gap of a liquid crystal display device formed on a substrate surface provided with the colored layer, for controlling a cell gap A similar forming method can be applied to the raised layer and the retardation layer.

  FIG. 1 is a schematic cross-sectional view of a color filter according to a third embodiment of the present invention.

  On a substrate 1 shown in FIG. 1, a black matrix 2 formed by patterning a metal such as chromium or a photosensitive black resin composition is formed by a known method. As the substrate 1 to be used, a transparent substrate is preferable, and specifically, a resin substrate such as a glass plate, polycarbonate, polymethyl methacrylate, polyethylene phthalate is preferably used. In addition, a transparent electrode made of a combination of metal oxides such as indium oxide, tin oxide, zinc oxide and antimony oxide is formed on the surface of the glass plate or resin plate for driving the liquid crystal after the liquid crystal panel is formed. Also good.

  First, the photosensitive resin composition according to the second embodiment of the present invention described above is uniformly applied on the substrate 1 by a spray coating method, a spin coating method, a roll coating or the like, and dried. Next, the obtained photosensitive resin composition layer is patterned by photolithography. That is, after exposure by irradiating active energy rays such as ultraviolet rays and electron beams through a photomask having a desired light-shielding pattern, development is performed using a developer such as an organic solvent or an alkaline aqueous solution. Here, in the exposure process, the photopolymerizable monomer contained in the photosensitive resin composition layer in the portion irradiated with the active energy ray is polymerized and cured. Moreover, when it contains photosensitive resin, this photosensitive resin is also bridge | crosslinked and hardened | cured.

  In order to improve exposure sensitivity, after forming a photosensitive resin composition layer, a solution of a water-soluble or alkaline water-soluble resin (for example, polyvinyl alcohol or water-soluble acrylic resin) is applied to the surface and dried. The film may be exposed after forming a film that suppresses the inhibition of polymerization by oxygen.

  Next, in the development step, a desired pattern is formed by washing away the portion that has not been irradiated with the active energy ray with a developer. As a development processing method, a shower development method, a spray development method, a dip (immersion) development method, a paddle (liquid accumulation) development method, or the like can be applied. As the developer, an alkaline developer such as an aqueous solution such as sodium carbonate or caustic soda, or an organic alkali solution such as dimethylbenzylamine or triethanolamine is mainly used. Moreover, as a developing solution, what added the antifoamer and surfactant was used as needed.

  Finally, it is baked and the same operation is repeated for other colors to produce a color filter. That is, the red pixel 3R, the green pixel 3G, and the blue pixel 3B are formed on the substrate 1 on which the black matrix 2 is formed. The red pixel 3R, the green pixel 3G, the blue pixel 3B, and the black matrix 2 constitute a colored layer.

  Furthermore, the counter substrate carrying layer 4 for making the cell gap of the liquid crystal display device uniform can be formed on these colored pixels. As shown in FIG. 1, the counter substrate support layer 4 is preferably formed at a position corresponding to the black matrix 2.

  In the color filter shown in FIG. 2, a retardation layer 6, a cell gap control raising layer 5, and a counter substrate carrying layer 4 are formed on a substrate 1 on which a colored layer is provided. At least one of the retardation layer 6, the cell gap control raising layer 5, and the counter substrate supporting layer 4 can be formed in the same manner as the colored layer described above.

  Next, a liquid crystal display device including the color filter described above will be described.

  FIG. 3 is a schematic cross-sectional view of a liquid crystal display device including a color filter according to the third embodiment of the present invention.

  A liquid crystal display device 7 shown in FIG. 3 is a typical example of a TFT drive type liquid crystal display device for a notebook personal computer, and includes a pair of transparent substrates 8 and 9 disposed so as to be opposed to each other. Liquid crystal (LC) is enclosed.

  The liquid crystal (LC) is TN (Twisted Nematic), STN (Super Twisted Nematic), IPS (In-Plane Switching), VA (Vertical Alignment), OCB (Optically Compensated Bc). .

  A TFT (thin film transistor) array 10 is formed on the inner surface of the first transparent substrate 8, and a transparent electrode layer 11 made of, for example, ITO is formed thereon. An alignment layer 12 is provided on the transparent electrode layer 11. A polarizing plate 13 including a retardation film is formed on the outer surface of the transparent substrate 8.

  On the other hand, a color filter 14 as shown in FIG. 1 or 2 is formed on the inner surface of the second transparent substrate 9. The red, green and blue filter segments constituting the color filter 14 are separated by a black matrix (not shown). A transparent protective film (not shown) is formed so as to cover the color filter 14 and further, a transparent electrode layer 15 made of, for example, ITO is formed thereon, and the alignment layer 16 is covered so as to cover the transparent electrode layer 15. Is provided. A polarizing plate 17 is formed on the outer surface of the transparent substrate 9. A backlight unit 19 having a three-wavelength lamp 18 is provided below the polarizing plate 13.

  Next, although the Example and comparative example of this invention are shown and this invention is demonstrated concretely, this invention is not limited to these. Further, since the material used in the present invention is extremely sensitive to light, it is necessary to prevent exposure to unnecessary light such as natural light, and all operations are performed under a yellow or red light. In Examples and Comparative Examples, “part” means “part by mass”. The symbol of the pigment indicates a color index number. For example, “PG36” represents “CI Pigment Green 36” and “PY150” represents “CI Pigment Yellow 150”.

[Synthesis of polymerization composition]
A polymerization composition composed of styrene and an unsaturated carboxylic acid-containing monomer used in Examples and Comparative Examples is synthesized as follows. The molecular weight of the resin is a polystyrene-reduced weight average molecular weight measured by GPC (gel permeation chromatography).

<Synthesis Example 1: Polymerization composition 1>
160 g of styrene, 20 g of maleic anhydride, 420 g of cyclohexanone and 2 g of azobisisobutyronitrile are added to a 5-neck reaction vessel having an internal volume of 2 liters, and heated at 80 ° C. for 6 hours while blowing nitrogen gas. -A maleic anhydride copolymer was obtained. The resulting styrene-maleic anhydride copolymer 1 had a weight average molecular weight of 11,000.

To the obtained styrene-maleic anhydride copolymer 1, 75 g of a 20% aqueous sodium hydroxide solution was added and heated at 75 ° C. for 1 hour. After cooling to 30 ° C., 170 g of 10% hydrochloric acid was added and stirred for 1 hour. Subsequently, 180 g of cyclohexanone and 180 g of water were added and stirred for 30 minutes, and then the aqueous layer was separated to obtain a styrene-maleic acid copolymer. The weight average molecular weight of the obtained styrene-maleic acid copolymer was 11,000.

<Synthesis Example 2: Polymerization composition 2>
160 g of styrene, 20 g of maleic anhydride, 420 g of cyclohexanone and 2 g of azobisisobutyronitrile are added to a 5-neck reaction vessel having an internal volume of 2 liters, and heated at 80 ° C. for 6 hours while blowing nitrogen gas. -A maleic anhydride copolymer was obtained. The resulting styrene-maleic anhydride copolymer 1 had a weight average molecular weight of 11,000.

To the resulting styrene-maleic anhydride copolymer 1, 36 g of 1-dodecanol and 0.5 g of triphenylphosphine were added and heated at 145 ° C. for 20 hours.

  Then, 39 g of 20% aqueous sodium hydroxide solution was added and heated at 30 ° C. for 1 hour. After cooling to 30 ° C., 71 g of 10% hydrochloric acid was added and stirred for 1 hour. Subsequently, 180 g of cyclohexanone and 180 g of water were added and stirred for 30 minutes, and then the aqueous layer was separated to obtain a styrene-maleic acid copolymer. The weight average molecular weight of the obtained styrene-maleic acid dodecyl ester copolymer was 12,000.

<Synthesis Example 3: Polymerization composition 3>
24 g of styrene-acrylic resin emulsion (AP1761, manufactured by Showa Polymer Co., Ltd., resin solid content 50%) and 96 g of propylene glycol monomethyl ether acetate were added and heated at 30 ° C. for 1 hour. The resulting styrene-maleic anhydride copolymer 1 had a weight average molecular weight of 4400.

<Synthesis Example 4: Polymerization Composition 4>
Add 432 g of cyclohexanone and 3 g of azobisisobutyronitrile in a 5-neck reaction vessel with an internal volume of 1 liter, and heat to 80 ° C. while blowing nitrogen gas, from 98.9 g of styrene and 9.1 g of acrylic acid. The resulting mixture was added dropwise over 2 hours. 30 minutes after the completion of dropping, 3 g of azoisobutyronitrile was added, and the mixture was further heated for 5 hours to obtain a styrene-acrylic acid copolymer. The weight average molecular weight of the obtained styrene-acrylic acid copolymer was 6900.

<Synthesis Example 5: Polymerization composition 5>
Into a five-neck reaction vessel with an internal volume of 1 liter, 432 g of propylene glycol monomethyl ether acetate and 13 g of azobisisobutyronitrile are added and heated to 80 ° C. while blowing nitrogen gas, and 98.9 g of styrene and acrylic acid are added. A mixture consisting of 9.1 g was added dropwise over 2 hours. Thirty minutes after the completion of dropping, 6.5 g of azoisobutyronitrile was added, and the mixture was further heated for 5 hours to obtain a styrene-acrylic acid copolymer. The weight average molecular weight of the obtained styrene-acrylic acid copolymer was 3100.

<Synthesis Example 6: Polymerization composition 6>
Add 432 g of propylene glycol monomethyl ether acetate and 13 g of azobisisobutyronitrile in a 5-neck reaction vessel with an internal volume of 1 liter, and heat to 80 ° C. while blowing nitrogen gas, and 96.3 g of styrene and acrylic acid A mixture consisting of 11.8 g was added dropwise over 2 hours. Thirty minutes after the completion of dropping, 6.5 g of azoisobutyronitrile was added, and the mixture was further heated for 5 hours to obtain a styrene-acrylic acid copolymer. The weight average molecular weight of the obtained styrene-acrylic acid copolymer was 3000.

<Synthesis Example 7: Polymerization composition 7>
24 g of styrene-acrylic resin emulsion (AP3770 manufactured by Showa Polymer Co., Ltd., resin solid content 50%) and 96 g of propylene glycol monomethyl ether acetate were added and heated at 30 ° C. for 1 hour. The resulting styrene-acrylic acid copolymer 1 had a weight average molecular weight of 8,600.

<Synthesis Example 8: Polymerization composition 8>
120 g of styrene, 20 g of maleic anhydride, 420 g of cyclohexanone and 2 g of azobisisobutyronitrile are added into a 5-neck reaction vessel having an internal volume of 2 liters, and heated at 80 ° C. for 15 hours while blowing nitrogen gas. -A maleic anhydride copolymer was obtained. The resulting styrene-maleic anhydride copolymer 1 had a weight average molecular weight of 37,000.

To the obtained styrene-maleic anhydride copolymer 1, 75 g of a 20% aqueous sodium hydroxide solution was added and heated at 75 ° C. for 1 hour. After cooling to 30 ° C., 170 g of 10% hydrochloric acid was added and stirred for 1 hour. Subsequently, 180 g of cyclohexanone and 180 g of water were added and stirred for 30 minutes, and then the aqueous layer was separated to obtain a styrene-maleic acid copolymer. The weight average molecular weight of the obtained styrene-maleic acid copolymer was 35500.

<Synthesis Example 9: Polymerization composition 9>
120 g of styrene, 30 g of maleic anhydride, 420 g of cyclohexanone and 2 g of azobisisobutyronitrile are added to a 5-neck reaction vessel having an internal volume of 2 liters, and heated at 80 ° C. for 6 hours while blowing nitrogen gas. -A maleic anhydride copolymer was obtained. The resulting styrene-maleic anhydride copolymer 1 had a weight average molecular weight of 13,000.

To the obtained styrene-maleic anhydride copolymer 1, 75 g of a 20% aqueous sodium hydroxide solution was added and heated at 75 ° C. for 1 hour. After cooling to 30 ° C., 170 g of 10% hydrochloric acid was added and stirred for 1 hour. Subsequently, 180 g of cyclohexanone and 180 g of water were added and stirred for 30 minutes, and then the aqueous layer was separated to obtain a styrene-maleic acid copolymer. The weight average molecular weight of the obtained styrene-maleic acid copolymer was 12000.

<Synthesis Example 10: Polymerization composition 10>
In a five-necked reaction vessel with an internal volume of 2 liters, 142.5 g of styrene, 7.5 g of maleic anhydride, 420 g of cyclohexanone and 2 g of azobisisobutyronitrile were added, and nitrogen gas was blown for 6 hours at 80 ° C. By heating, a styrene-maleic anhydride copolymer 4 was obtained. The resulting styrene-maleic anhydride copolymer 4 had a weight average molecular weight of 13,000.

To the obtained styrene-maleic anhydride copolymer 1, 75 g of a 20% aqueous sodium hydroxide solution was added and heated at 75 ° C. for 1 hour. After cooling to 30 ° C., 170 g of 10% hydrochloric acid was added and stirred for 1 hour. Subsequently, 180 g of cyclohexanone and 180 g of water were added and stirred for 30 minutes, and then the aqueous layer was separated to obtain a polymer composition 10 of a styrene-maleic acid copolymer. The resulting styrene-maleic acid copolymer composition 10 had a weight average molecular weight of 12,000. The results are shown in Table 1 below.

[Synthesis of acrylic resin]
The acrylic resin used in Examples and Comparative Examples is synthesized as follows. The molecular weight of the acrylic resin is a polystyrene-equivalent weight average molecular weight measured by GPC (gel permeation chromatography).

<Synthesis example 1> Acrylic resin 1
In a 5-neck reaction vessel with an internal volume of 2 liters, add 800 g of propylene glycol monomethyl ether acetate, 10 g of methacrylic acid, 40 g of methyl methacrylate, 80 g of butyl methacrylate, 40 g of hydroxyethyl methacrylate and 2 g of azobisisobutyronitrile, and add nitrogen gas. Was heated at 80 ° C. for 6 hours to obtain acrylic resin 1. The obtained acrylic resin 1 had a weight average molecular weight of 40,000.

<Synthesis example 2> Acrylic resin 2
An acrylic resin 2 was obtained in the same manner as in Synthesis Example 8 except that 40 g of methacrylic acid was used. The resulting acrylic resin 2 had a weight average molecular weight of 40,000.

<Synthesis example 3> Acrylic resin 3
In a five-necked reaction vessel with an internal volume of 2 liters, propylene glycol monomethyl ether acetate 800 g, methacrylic acid 30 g, butyl methacrylate 70 g, hydroxyethyl methacrylate 40 g, p-cumylphenoxyethyl methacrylate 60 g and azobisisobutyronitrile 2 g In addition, while blowing nitrogen gas, it was heated at 80 ° C. for 6 hours to obtain an acrylic resin 3. The weight average molecular weight of the obtained acrylic resin 3 was 30000.

<Synthesis example 4> Acrylic resin 4
An acrylic resin 4 was obtained in the same manner as in Synthesis Example 10 except that 33 g of methacrylic acid was used. The weight average molecular weight of the obtained acrylic resin 4 was 30000.

<Synthesis Example 5> Acrylic resin 5
In a five-necked reaction vessel with an internal volume of 2 liters, propylene glycol monomethyl ether acetate 800 g, methacrylic acid 40 g, butyl methacrylate 40 g, hydroxyethyl methacrylate 60 g, p-cumylphenoxyethyl methacrylate 60 g and azobisisobutyronitrile 4 g In addition, while blowing nitrogen gas, it was heated at 80 ° C. for 6 hours to obtain an acrylic resin. The acrylic resin was further reacted with 45 g of methacryloyloxyethyl isocyanate at 60 ° C. for 8 hours to obtain an acrylic resin 5. The acrylic resin 5 had a weight average molecular weight of 25,000.

<Synthesis Example 6> Acrylic resin 6
An acrylic resin 5 was obtained in the same manner as in Synthesis Example 10 except that 15 g of methacryloyloxyethyl isocyanate was used. The acrylic resin 5 had a weight average molecular weight of 25,000. The results are shown in Table 2 below.

[Synthesis of pigments]
The pigments used in the examples and comparative examples are synthesized as follows.

(Blue pigment)
Blue Pigment 1 (CI Pigment Blue 15: 6, “LIONOL BLUE ES” manufactured by Toyo Ink Co., Ltd .; B-1) 200 parts, sodium chloride 1600 parts and diethylene glycol (manufactured by Tokyo Chemical Industry Co., Ltd.) 100 parts stainless steel 1 gallon kneader (Made by Inoue Seisakusho) and kneaded at 70 ° C. for 12 hours. Next, this mixture is poured into about 5 liters of warm water, heated to about 70 ° C. and stirred with a high speed mixer for about 1 hour to form a slurry, then filtered and washed to remove sodium chloride and diethylene glycol, It was dried at 80 ° C. for 24 hours to obtain 198 parts of a salt milled pigment (blue pigment 2).
Further, 160 parts of blue pigment 2, 1600 parts of sodium chloride, and 100 parts of diethylene glycol (manufactured by Tokyo Chemical Industry Co., Ltd.) were charged into a stainless 1 gallon kneader (manufactured by Inoue Seisakusho) and kneaded at 70 ° C. for 15 hours. Next, this mixture is poured into about 5 liters of warm water, heated to about 70 ° C. and stirred with a high speed mixer for about 1 hour to form a slurry, then filtered and washed to remove sodium chloride and diethylene glycol, It was dried at 80 ° C. for 24 hours to obtain 158 parts of a salt milled pigment (blue pigment 3).

(Purple pigment)
300 parts of purple pigment 1 was added to 3000 parts of 96% sulfuric acid, stirred for 1 hour, and poured into water at 5 ° C. After stirring for 1 hour, it was filtered, washed with warm water until the washing solution became neutral, and dried at 70 ° C. 120 parts of the obtained acid pasting pigment, 1600 parts of sodium chloride, and 100 parts of diethylene glycol (manufactured by Tokyo Chemical Industry Co., Ltd.) were charged into a stainless gallon kneader (manufactured by Inoue Seisakusho) and kneaded at 90 ° C. for 18 hours. Next, this mixture is poured into about 5 liters of warm water, heated to about 70 ° C. and stirred with a high speed mixer for about 1 hour to form a slurry, then filtered and washed to remove sodium chloride and diethylene glycol, It was dried at 80 ° C. for 24 hours to obtain 118 parts of a salt milled pigment (purple pigment 2).

(Red pigment)
136 parts of red pigment 1 (CI Pigment Red 254, “IRGAPHOR RED B-CF” manufactured by Ciba Specialty Chemicals), 24 parts of dispersant A-1 shown in Table 2, 1600 parts of sodium chloride, and diethylene glycol (Tokyo Kasei Co., Ltd.) 190 parts) was charged in a stainless steel 1 gallon kneader (manufactured by Inoue Seisakusho) and kneaded at 60 ° C. for 8 hours. Next, this mixture is poured into about 5 liters of warm water, heated to about 70 ° C. and stirred with a high speed mixer for about 1 hour to form a slurry, then filtered and washed to remove sodium chloride and diethylene glycol, It was dried at 80 ° C. for 24 hours to obtain 156 parts of a salt milled pigment (red pigment 2).

  160 parts of red pigment 3 (CI Pigment Red 177, “CROMOPHTAL RED A2B”; R-3) manufactured by Ciba Specialty Chemicals, 1600 parts of sodium chloride, and 190 parts of diethylene glycol (manufactured by Tokyo Chemical Industry Co., Ltd.) are made of 1 gallon kneader made of stainless steel. (Made by Inoue Seisakusho) and kneaded at 60 ° C. for 12 hours. Next, this mixture is poured into about 5 liters of warm water, heated to about 70 ° C. and stirred with a high speed mixer for about 1 hour to form a slurry, then filtered and washed to remove sodium chloride and diethylene glycol, It was dried at 80 ° C. for 24 hours to obtain 156 parts of a salt milled pigment (red pigment 4).

(Green pigment)
In a molten salt of 200 ° C. of 356 parts of aluminum chloride and 6 parts of sodium chloride, 46 parts of zinc phthalocyanine was dissolved, cooled to 130 ° C., and stirred for 1 hour. The reaction temperature was raised to 180 ° C., and bromine was added dropwise at 10 parts per hour for 10 hours. Thereafter, chlorine was introduced at 0.8 parts per hour for 5 hours. The reaction solution was gradually poured into 3200 parts of water, then filtered and washed with water to obtain 107.8 parts of a crude zinc halide phthalocyanine pigment. The average number of bromine contained in one molecule of the crude zinc halide phthalocyanine pigment was 14.1 and the average number of chlorine was 1.9. 120 parts of the obtained crude zinc halide phthalocyanine pigment, 1600 parts of crushed salt and 270 parts of diethylene glycol were charged into a stainless steel 1 gallon kneader (manufactured by Inoue Seisakusho) and kneaded at 70 ° C. for 12 hours. The mixture was poured into 5000 parts of warm water, stirred at a high speed mixer for about 1 hour while being heated to about 70 ° C. to form a slurry, filtered and washed repeatedly to remove salt and solvent, and then at 80 ° C. for 24 hours. Drying gave 117 parts of salt milled pigment (green pigment 1).

(Yellow pigment)
100 parts of quinophthalone-based yellow pigment PY138 (“Pariotol Yellow K0961HD” manufactured by BASF), 5 parts of a dye derivative (D-3), 750 parts of crushed salt, and 180 parts of diethylene glycol are made of 1 gallon kneader made of stainless steel (manufactured by Inoue Seisakusho). And kneaded at 60 ° C. for 6 hours. The mixture was added to 3000 parts of warm water, stirred at a high speed mixer for about 1 hour while being heated to about 80 ° C. to form a slurry, filtered and washed repeatedly to remove salt and solvent, and then at 80 ° C. for 24 hours. Dried to obtain 100 parts of a salt milled pigment (yellow pigment 1).

Example 1
The blue coloring composition 1 used for color filter preparation was prepared as follows.

<Blue coloring composition 1>
A mixture having the following composition was uniformly stirred and mixed, then dispersed in a sand mill for 5 hours using glass beads having a diameter of 1 mm, and then filtered through a 5 μm filter to prepare a blue pigment dispersion.

Blue pigment 3 7.9 parts Purple pigment 2 5.8 parts Dispersant ("Ajisper PB821" manufactured by Ajinomoto Fine Techno Co., Ltd.) 1.8 parts Acrylic resin 2 (solid content 20%) 36.5 parts Cyclohexanone 48 parts The composition mixture was stirred and mixed to be uniform, and then filtered through a 5 μm filter to obtain a blue colored composition 1.

42 parts of the above dispersion composition 10 parts of trimethylolpropane triacrylate (Biscoat # 295 manufactured by Osaka Organic Chemical Industry Co., Ltd.) 4.8 parts Photopolymerization initiator (“Irgacure-369” manufactured by Ciba Geigy) 2.8 parts Photosensitizer ("EAB-F" manufactured by Hodogaya Chemical Co., Ltd.) 0.2 parts Cyclohexanone 40.2 parts (Examples 2 to 11, Comparative Examples 1 to 9)
Colored compositions 2 to 20 were obtained in the same manner as in Example 1 except that the resins described in Table 3 below were used as the pigment in the dispersion, the resin used in the dispersion, and the colored composition.

  About the photosensitive resin composition which concerns on the said Example and comparative example, the following characteristics were measured and evaluated.

1. Long-term storage stability evaluation E type viscometer ("ELD type viscometer" manufactured by Toki Sangyo Co., Ltd.) It was measured under the condition of a rotation speed of 20 rpm at 25 ° C. From the values of the initial viscosity and the viscosity with time, the rate of change with time in viscosity was calculated by the following formula.

[Change in viscosity with time] = | ([initial viscosity] − [viscosity with time]) / [initial viscosity] | × 100
Long-term storage stability was evaluated according to the following criteria.

○: Viscosity change rate with time is 10% or less Δ: Viscosity change rate with time is 10% to 20%
X: Viscosity change rate with time exceeds 20%.

2. Thickness direction retardation value Rth
Each color coating film was prepared by the following procedure, and the thickness direction retardation value was measured.

  Each color coloring composition shown in Table 3 was applied to a glass substrate by spin coating, and then pre-baked at 70 ° C. for 20 minutes in a clean oven. Next, the substrate was cooled to room temperature, and then exposed to ultraviolet rays using an ultrahigh pressure mercury lamp. Thereafter, the substrate was spray-developed using a sodium carbonate aqueous solution at 23 ° C., washed with ion-exchanged water, and air-dried. Then, post-baking was performed at 230 ° C. for 30 minutes in a clean oven to obtain a coating film for each color pixel. The film thickness of the dried coating film was 1.8 μm in all cases. In addition, a coating film is formed in the same manner to form a counter substrate supporting layer for uniformizing the cell gap of a liquid crystal display device, a cell gap control raising layer, and a photosensitive resin composition for a retardation layer. did.

  Thickness direction retardation value is measured by using retardation measurement device ("RETS-100" manufactured by Otsuka Electronics Co., Ltd.) to measure retardation [Delta] ([lambda]) from the direction inclined 45 [deg.] From the normal direction of the substrate on which the coating film is formed. Then, the thickness direction retardation value (Rth) was calculated from the three-dimensional refractive index obtained by using this value, from Equation 1. However, measurement was performed at a wavelength of 610 nm for a red colored pixel, 550 nm for a green colored pixel, and 450 nm for a blue colored pixel.

Rth = {(Nx + Ny) / 2−Nz} × d
(Where Nx is the refractive index in the x direction in the plane of the colored pixel layer, Ny is the refractive index in the y direction in the plane of the colored pixel layer, and Nz is the refractive index in the thickness direction of the colored pixel layer. There is a slow axis where Nx is Nx ≧ Ny, and d is the thickness (nm) of the colored pixel layer.
Table 4 below shows the thickness direction retardation value Rth of each color coating film prepared from each color coloring composition shown in Table 3 above. In addition, the retardation plate used in the liquid crystal display device, a combination of the thickness direction retardation value Rth of the liquid crystal material and the thickness direction retardation value Rth of the colored pixel layer, when viewed from an oblique direction during black display When the coloration of the liquid crystal display device is minimized, the thickness direction retardation value Rth of the colored pixel layer is −12 to 2 nm for the red pixel, −12 to 2 nm for the green pixel, and −12 to 2 nm for the blue pixel, respectively. Met.

  The thickness direction retardation value was evaluated according to the following criteria.

    ○: It is included in a range of −12 to 2 nm for a red pixel, −12 to 2 nm for a green pixel, and −12 to 2 nm for a blue pixel.

    X: Not included in the above range.

  The evaluation results are shown in Table 4 below.

  Regarding the cell gap control raising layer and the retardation resin composition, the obtained Rth values are shown in Table 4 below.

3. Sensitivity evaluation The sensitivity of each photosensitive coloring composition, the cell gap control raised layer and the retardation resin composition shown in Table 3 was evaluated as follows.

That is, first, the obtained photosensitive composition was applied onto a glass substrate by spin coating, and then pre-baked at 70 ° C. for 15 minutes to form a coating film having a thickness of 2.3 μm. Next, UV exposure was performed through a photomask having a 50 μm fine line pattern by a proximity exposure method using UV as an exposure light source. The exposure amount was set to 8 levels of 30, 40, 50, 60, 70, 80, 90, and 100 mJ / cm ² .

  Next, shower development was performed using a 1.25% by mass sodium carbonate solution, followed by washing with water and a heat treatment at 230 ° C. for 20 minutes to complete the patterning.

  The film thickness of the obtained filter segment was divided by the film thickness (2.3 μm) of the unexposed / undeveloped portion to calculate the remaining film ratio. An exposure sensitivity curve was plotted with the horizontal axis representing the exposure amount and the vertical axis representing the remaining film ratio after development. From the obtained exposure sensitivity curve, the minimum exposure amount at which the residual film ratio reached 80% or more was defined as the saturation exposure amount, and the sensitivity was evaluated according to the following criteria.

○: Saturation exposure is 50 mJ / cm ² or less Δ: Saturation exposure exceeds 50 and 100 mJ / cm ² or less X: Saturation exposure exceeds 100 mJ / cm ²

4). Patterning property evaluation About each photosensitive coloring composition prepared in each Example and comparative example, the cell gap control raising layer, and the photosensitive resin composition for retardation layer, the patterning performance was evaluated as follows. Went.

  That is, first, the obtained black photosensitive composition was applied onto a glass substrate by spin coating, and prebaked at 70 ° C. for 15 minutes to form a coating film having a thickness of 2.3 μm. Next, ultraviolet exposure was performed through a photomask provided with a stripe pattern having a line width of 6 to 20 μm by a proximity exposure method using ultraviolet light as an exposure light source. The exposure amount was the saturation exposure amount described above.

  Next, it was washed with water after shower development using a 1.25% by mass sodium carbonate solution. The development time was set to an appropriate time for washing away the unexposed coating film. Next, heat treatment was performed at 230 ° C. for 20 minutes to produce a test substrate.

5. Resistance Evaluation In the same manner as the patterning evaluation, the glass substrate on which the stripe pattern was formed was exposed to the following conditions, and the appearance change of the pattern before and after that was observed with an optical microscope.

N-methyl-2-pyrrolidone solvent immersion 30 minutes (temperature 24 ° C)
Isopropyl alcohol solvent immersion 30 minutes (same as above)
γ-butyrolactone solvent immersion 30 minutes (same as above)
Resistance evaluation was performed according to the following criteria.

○: No change in appearance under all conditions ×: Problems such as pattern peeling, chipping, and cracks are observed.

The above results are shown in Table 4 below.

  From Table 4 above, the resin compositions according to Examples 1 to 14 using the polymerization composition within the scope of the present invention are the long-term storage stability, sensitivity, patternability, and further photosensitivity of the photosensitive resin composition. It can be seen that both the thickness direction retardation value and the resistance of the colored layer obtained by curing the resin composition are good.

  On the other hand, it turns out that the resin composition which concerns on Comparative Examples 1-9 using the polymerization composition outside the range of this invention is inferior in at least any of the said characteristics.

(Example 12)
1. Production of Color Filter A color filter was produced by combining the photosensitive coloring compositions shown in Table 4 with the method described below.

  First, the photosensitive red composition (coloring composition 11) was applied by spin coating to a glass substrate on which a black matrix had been formed in advance, and then prebaked at 70 ° C. for 20 minutes in a clean oven. Next, after cooling the substrate to room temperature, ultraviolet rays were exposed through a photomask using an ultrahigh pressure mercury lamp.

  Thereafter, the substrate was spray-developed using a sodium carbonate aqueous solution at 23 ° C., washed with ion-exchanged water, and air-dried. Further, post-baking was performed at 230 ° C. for 30 minutes in a clean oven to form striped red pixels on the substrate.

  Next, the photosensitive green composition (coloring composition 10) is used to form a green pixel in the same manner, and further, the photosensitive blue composition (coloring composition 1) is used to form a blue pixel, and color Filter 1 was obtained. The formed film thickness of each color pixel was 2.0 μm.

2. Production of Liquid Crystal Display Device An overcoat layer was formed on the obtained color filter, and a polyimide alignment layer was formed thereon. A polarizing plate was formed on the other surface of this glass substrate. On the other hand, a TFT array and a pixel electrode were formed on one surface of another (second) glass substrate, and a polarizing plate was formed on the other surface.

  The two glass substrates thus prepared face each other so that the electrode layers face each other, and are aligned using spacer beads while keeping the distance between both substrates constant, and the periphery is left so as to leave an opening for injecting the liquid crystal composition. Sealed with a sealant. A liquid crystal composition for VA was injected from the opening to seal the opening.

  The polarizing plate was provided with an optical compensation layer optimized to display a wide viewing angle.

The liquid crystal display device thus fabricated was combined with a backlight unit to obtain a VA display mode liquid crystal panel.

(Example 13, Comparative Examples 10-11)
Color filters 2 to 4 were obtained in the same manner as in Example 12 except that the photosensitive coloring composition described in Table 5 below was used as the photosensitive coloring composition. A liquid crystal display device was manufactured using this color filter.

  In addition, the composition of the coloring composition 21 used in Comparative Example 11 is as follows.

Pigment: Blue pigment 1, purple pigment 2
Resin in dispersion: acrylic resin 2 ... 36.5 parts Resin in colored composition: polymerization composition 4 ... 4 parts
: Acrylic resin 6 ... 12 parts <Visibility evaluation during black display of liquid crystal display device>
The produced liquid crystal display device displays black, and the amount of light (orthogonal transmitted light; leaked light) leaking from the normal direction (substantially vertical direction) of the liquid crystal panel and the azimuth (oblique) inclined 45 ° from the normal direction. Visual observation was performed. Also, the chromaticity (u (、), v (⊥)) when viewed from a substantially vertical direction when displaying black and the chromaticity when viewed from an orientation inclined up to 60 ° from the normal direction of the display surface ( u (45), v (45)) were measured with Topcon BM-5A, the color difference Δu′v ′ was calculated, and the maximum value of Δu′v ′ at 0 ≦ θ ≦ 60 ° was determined.

  The evaluation rank is as follows, and the results are shown in Table 5 below.

○: Diagonal colored Δu′v ′ for visibility evaluation is 0.02 or less ×: Diagonal colored Δu′v ′ for visibility evaluation is larger than 0.02

  From Table 5 above, Example 12 in which the color filter formed so that the thickness direction retardation value of the red color pixel, the green color pixel, and the blue color pixel layer satisfies 2 to −12 nm was used for the liquid crystal display device and 13 shows that the visibility in the oblique direction is good.

  In contrast, in Comparative Examples 10 and 11, the red color pixel, the green color pixel, and the blue color pixel layer are not formed so that the thickness direction retardation value thereof satisfies 2 to −12 nm. It turns out that is bad.

It is a schematic sectional drawing which shows the color filter which concerns on one Embodiment of this invention. It is a schematic sectional drawing which shows the other example of the color filter which concerns on one Embodiment of this invention. It is a schematic sectional drawing which shows an example of the liquid crystal display device provided with the color filter of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Glass substrate, 2 ... Black matrix, 3R, 3G, 3B ... Colored pixel, 4 ... Opposite substrate support layer, 5 ... Cell gap control raising layer, 6 ... Phase difference layer, 7 ... Liquid crystal display device, 8, DESCRIPTION OF SYMBOLS 9 ... Transparent substrate, 10 ... TFT array, 11, 15 ... Transparent electrode, 12, 16 ... Orientation layer, 13, 17 ... Polarizing plate, 14 ... Color filter, 18 ... Three wavelength lamp, 19 ... Backlight unit.

Claims (4)

It is obtained by copolymerizing styrene and an unsaturated carboxylic acid-containing monomer, has a weight average molecular weight of 30000 or less, a solid content acid value of 10 to 150 mgKOH / g, and a styrene content of 75 mol% or more. A polymerization composition;
A photopolymerizable monomer;
A photopolymerization initiator;
An acrylic resin having a solid content acid value of 20 to 180 mgKOH / g and a double bond equivalent of 100 or more;
Containing
A photosensitive resin composition in which an organic pigment is further dispersed in a photosensitive resin composition having a solid content of 3 to 60% by mass in solid content, wherein the coating film of the photosensitive resin composition is coated with the photosensitive resin composition. A photosensitive resin composition for a color filter, having a thickness direction retardation after curing of 2 to -12 nm . A color filter comprising a substrate and a colored layer formed on the substrate, wherein the colored layer is a cured film obtained by applying and developing the photosensitive resin composition according to claim 1 , and A color filter, wherein a retardation value Rth in the thickness direction of the colored layer represented by the formula is 2 to -12 nm.
Rth = {(Nx + Ny) / 2−Nz} × d
(In the formula, Nx represents the refractive index in the x direction in the plane of the colored pixel layer, Ny represents the refractive index in the y direction in the plane of the colored pixel layer, and Nz represents the refractive index in the thickness direction of the colored pixel layer. .) Selected from the group consisting of a substrate, a colored layer formed on the substrate, and a counter substrate carrying layer, a cell gap control raised layer, and a retardation layer formed on the substrate on which the colored layer is formed a color filter comprising at least one which, the counter substrate bearing layer, the cell gap control raising layer, and at least one member selected from the group consisting of retardation layer according to claim 1 A color filter, which is a cured film obtained by applying and developing a photosensitive resin composition. The color filter according to claim 3 , wherein the colored layer is the colored layer according to claim 2 .

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