JP2000234007A - Pigment dispersing agent, pigment dispersion composition comprising same and colored photosensitive composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pigment dispersing agent which effectively prevents autohesion of a pigment and realizes good dispersion of the pigment. SOLUTION: This pigment dispersing agent comprises a graft copolymer having a nitrogen atom and an alcoholic hydroxyl group. The graft copolymer preferably contains, as the copolymer units, a polymerizable oligomer having ethylenically unsaturated double bond at the terminal, a nitrogen-containing monomer having a nitrogen atom and an ethylenically unsaturated double bond, and a polymerizable monomer having an alcoholic hydroxyl group. Alternatively the graft copolymer has preferably an alcoholic hydroxyl group and contains, as the copolymer units, a polymerizable oligomer having an ethylenically unsaturated double bond at the terminal and a nitrogen-containing monomer having a nitrogen atom and an ethylenically unsaturated double bond.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pigment dispersant, a pigment dispersion composition containing the same, and a colored photosensitive composition. A pigment containing the pigment dispersant, having excellent pigment dispersibility, fluidity, etc., excellent coloring power, and suitable for use in a wide range of paints, printing inks, color display plates, etc. A dispersion composition, and containing the pigment dispersion composition, forming a multicolor image on a substrate such as a color proof,
The present invention relates to a colored photosensitive composition that can be suitably used for producing a color filter used for a liquid crystal color display and the like.

[0002]

2. Description of the Related Art Conventionally, pigments exhibit a vivid color tone and high coloring power, and have been widely used in many fields.
Among these pigments, those which are practically important are generally fine particles, and a clear color tone and high coloring power can be obtained by preventing the pigments from agglomerating and miniaturizing them. However, as the pigment is further refined, the dispersion of the pigment often exhibits a higher viscosity. For this reason, when this pigment dispersion is prepared on an industrial scale, it becomes difficult to take out the pigment dispersion from the dispersing machine, or it becomes impossible to transport by a pipeline, and further, gelation occurs during storage. There is a problem that it cannot be used.

Incidentally, the colored photosensitive composition containing the pigment is useful as a material for a color filter used for a liquid crystal display or the like. When a color filter is produced using the colored photosensitive composition, the quality, A pigment dispersion method which is excellent in terms of production stability and the like is widely used. In the pigment dispersion method, a coating solution of the colored photosensitive composition is applied on a transparent substrate to provide a colored photosensitive layer, and after pattern exposure, development is performed to form a first color pixel pattern,
This is repeated a plurality of times to form pixel patterns of a plurality of colors on the transparent substrate.

However, since a pigment is used here as a coloring material, if the pigment is not finely divided, light is scattered and absorbed by the pigment, and the light transmittance is reduced. Furthermore, there is a problem that the polarization axis is rotated due to scattering of light, birefringence, etc. by the pigment, and the contrast of the liquid crystal display device is reduced (the 7th color optical conference in 1990, 512-color display 10. 4 "size TFT-LC
D color filter, Ueki, Koseki, Fukunaga, Yamanaka). For this reason, in the colored photosensitive composition, it is necessary to disperse the pigment in a highly fine state.

Therefore, it is conventionally known to use various dispersants in order to obtain a pigment dispersion or a colored photosensitive composition having excellent fluidity and dispersibility. The dispersants can be broadly classified into polymer dispersants and low molecular compound dispersants. Examples of the polymer dispersants include polyacrylates, sodium maleate olefin copolymers, and polyesters having a terminal carboxyl group (Japanese Patent Publication No. 54-34
009), a polyester having an acidic group and / or a basic group starting from tetrakis (2-hydroxyalkyl) ethylenediamine (JP-A-2-2452).
No. 31), a macromonomer (an oligomer having an ethylenically unsaturated group at a terminal), a monomer having a hydroxyl group,
Copolymers comprising four kinds of carboxy group-containing monomers and monomers other than these (JP-A-8-259876) are known, and the low-molecular compound dispersants include sorbitan fatty acid esters, Ethylene alkylamines, alkyldiamines, alkanolamine derivatives (US Pat. No. 3,536,510) are known.

Among these dispersants, JP-A-7-14
0654, JP-A-5-273411, JP-A-8-259
JP-A-876-876 discloses a copolymer containing a macromonomer (an oligomer having an ethylenically unsaturated group at a terminal) in a colored photosensitive composition as a material for a color filter, a color proof, or the like. It is disclosed that the use of a copolymer containing a macromonomer (oligomer having an ethylenically unsaturated group at the terminal) can provide a pigment dispersion having a small pigment particle size and excellent dispersion stability. However, since the macromonomer does not contain a nitrogen atom, there is a problem that even when used as a dispersant, the macromonomer does not function alone and must be used in combination with another dispersant. When the macromonomer is used as a dispersant, the thickening effect seen in the polymer dispersant is small and good, but there is a problem that the effect of atomizing the pigment is not sufficient and the dispersibility is not sufficient.

On the other hand, a colored photosensitive composition containing a pigment exhibiting a clear color tone and high coloring power is useful as an image forming material for producing, for example, a color proof or a color filter. When a colored image is formed using the colored photosensitive composition, generally, after applying a coating solution of the colored photosensitive composition on a substrate to form a layer of the colored photosensitive composition, exposure and development are performed. As the developing solution used in this development, an alkaline aqueous solution having little effect on the environment is often used, and the layer of the colored photosensitive composition, that is, the binder ( Binder) is required to be soluble in the alkaline aqueous solution. On the other hand, as a solvent (dispersion medium of the pigment) used in the coating solution of the colored photosensitive composition, an organic solvent is effective because of easy drying after coating. For this reason, the binder in the colored photosensitive composition must have an acidic group and have a property of being soluble in a suitable organic solvent, and in the colored photosensitive composition, the organic pigment is It has such properties and is dispersed in the binder having an acidic group.

The layer made of such a colored photosensitive composition is
In general, since it is required to be extremely thin and to exhibit a high color density with a small thickness, it is possible to disperse an organic pigment in a highly fine state in a binder having an acidic group soluble in an organic solvent. Required. However, at present, a pigment dispersion having excellent dispersibility and fluidity of the pigment, a pigment dispersion composition containing the pigment, and a colored photosensitive composition have not yet been provided.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned conventional problems and achieve the following objects. That is, an object of the present invention is to provide a pigment dispersant which realizes stable and good dispersibility and fluidity of the pigment without aggregating the pigment and also has excellent light transmittance. Further, the present invention contains the pigment dispersant, dispersibility of the pigment,
An object of the present invention is to provide a pigment dispersion composition which is excellent in fluidity and the like, has high coloring power, is excellent in alkali developability, and can be suitably used in a wide range of paints, printing inks, color display boards and the like. Further, the present invention provides a color filter containing the pigment dispersion composition, having high coloring power, excellent alkali developability, forming a multicolor image on a substrate such as a color proof, and a liquid crystal color display. An object of the present invention is to provide a colored photosensitive composition that can be suitably used for the production of, for example.

[0010]

Means for Solving the Problems As a result of intensive studies conducted by the present inventors to solve the above problems, the following findings were obtained. That is, when an organic pigment is dispersed in a binder having an acidic group soluble in an organic solvent, an intermolecular force acts between the acidic group and the organic pigment, which tends to increase the viscosity. Although the dispersion stability is improved by this thickening, the handleability, workability and the like are reduced, and the organic pigment tends to be hard to be fine. For this reason, a dispersant capable of accelerating dispersion without thickening is desired, and as such a dispersant, a low molecular compound dispersant, particularly an amine compound, etc., is known. However, in the case of the amine compound or the like, an acid group and a salt are formed, and the photosensitive resin layer is easily dissolved in a developing solution.
It can adversely affect later development. Alkaline dispersants and easily water-soluble dispersants have the same tendency as the above-mentioned amine compounds. On the other hand, in the case of the above-mentioned macromonomer, it is a finding that the problem of thickening can be suppressed to some extent due to the steric effect of the polymer chain, but the dispersibility of the pigment is not sufficient.

The present invention is based on the above findings by the present inventors, and the means for solving the above problems are as follows. That is, <1> a pigment dispersant comprising a graft copolymer having a nitrogen atom and an alcoholic hydroxyl group. <2> a graft copolymer, a polymerizable oligomer having an ethylenically unsaturated double bond at a terminal, a nitrogen-containing monomer having a nitrogen atom and an ethylenically unsaturated double bond,
The pigment dispersant according to <1>, further including a polymerizable monomer having an alcoholic hydroxyl group as a copolymer unit. <3> In the graft copolymer, as the copolymer unit, the polymerizable oligomer is 20 to 98% by weight, the nitrogen-containing monomer is 1 to 40% by weight, and the polymerizable monomer is 1 to
The pigment dispersant according to <2>, which contains 40% by weight. <4> The polymerizable oligomer is at least one oligomer selected from a polymer of an alkyl (meth) acrylate and a copolymer of an alkyl (meth) acrylate and polystyrene, and has a number average molecular weight of 1,000 to 1,000.
10,000, and the pigment dispersant according to the above <2> or <3>, having a (meth) acryloyl group at a terminal. <5> a graft copolymer having an alcoholic hydroxyl group, a polymerizable oligomer having an ethylenically unsaturated double bond at a terminal, and a nitrogen-containing monomer having a nitrogen atom and an ethylenically unsaturated double bond. The pigment dispersant according to <1>, which is contained as a copolymer unit. <6> The pigment dispersant according to <5>, wherein the graft copolymer includes, as a copolymer unit, 20 to 99% by weight of a polymerizable oligomer and 1 to 80% by weight of a nitrogen-containing monomer. is there. <7> The polymerizable oligomer is at least one alcoholic hydroxyl group-containing oligomer selected from a polymer of alkyl (meth) acrylate and a copolymer of alkyl (meth) acrylate and polystyrene, The pigment dispersant according to <5> or <6>, having a molecular weight of 1,000 to 10,000 and having a (meth) acryloyl group at a terminal. <8> The nitrogen-containing monomer is at least one selected from compounds represented by the following general formula (1).
The pigment dispersant according to any one of 2> to <7>. General formula (1)

[0012]

Embedded image

In the general formula (1), R¹¹Is hydrogen
Represents an atom or a methyl group. R¹²Is an alkyl having 1 to 8 carbon atoms
Represents a kylene group. X¹Is -N (R¹³) (R¹⁴), (R
¹³And R¹⁴Is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or
Represents a phenyl group), -R ¹⁵N (R¹⁶) (R¹⁷) (R
¹⁵Represents an alkylene group having 1 to 6 carbon atoms;¹⁶And R
¹⁷Is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or phenyl.
Represents a pyryl group), pyrrolidino group, pyrrolidyl group, pyridyl
Group, piperidino group or morpholino group. m and n
Represents 1 or 0. <9> Graft copolymer further copolymerizes acidic monomer
Any of <1> to <8> above as a unit
It is a pigment dispersant of the description. <10> The face according to any one of <1> to <9>.
Dispersant and pigment are dispersed in an organic solvent
Is a pigment dispersion composition characterized by the following. <11> The pigment dispersion composition according to <10>, and an acid
Binder polymer having a functional group and ethylenically unsaturated
Polyfunctional monomer having two or more double bonds and photopolymerization
A colored photosensitive composition characterized by containing an initiator and
is there.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION << Pigment Dispersant >> The pigment dispersant of the present invention contains a graft copolymer having a nitrogen atom and an alcoholic hydroxyl group, and contains other components appropriately selected as necessary.

(Graft Copolymer) The graft copolymer has at least a nitrogen atom and an alcoholic hydroxyl group, and may contain an acidic monomer, another monomer or the like as a copolymer unit. In the graft copolymer, the nitrogen atom may be present in the main chain or may be present in a side chain, and the alcoholic hydroxyl group may be present in the main chain or a side chain. May be present.

In the present invention, the first embodiment in which the nitrogen atom and the alcoholic hydroxyl group are present in the main chain as shown in FIG. 1, or the nitrogen atom in the main chain as shown in FIG. The second embodiment in which the alcoholic hydroxyl group is present in the side chain and the alcoholic hydroxyl group is present particularly preferably.

The weight average molecular weight (Mw) of the graft copolymer is preferably 3,000 to 100,000, more preferably 5,000 to 50,000. If the weight average molecular weight (Mw) is less than 3,000, aggregation of the pigment cannot be prevented and the viscosity may increase. If the weight average molecular weight (Mw) exceeds 100,000, the solubility in an organic solvent is insufficient, and the viscosity is low. May rise. The weight average molecular weight is a weight average molecular weight in terms of polystyrene measured by gel permeation chromatography (carrier: tetrahydrofuran).

First Embodiment The graft copolymer according to the first embodiment has a polymerizable oligomer having an ethylenically unsaturated double bond at a terminal and a nitrogen atom and an ethylenically unsaturated double bond. At least a nitrogen-containing monomer and a polymerizable monomer having an alcoholic hydroxyl group as a copolymer unit, and, if necessary,
The acidic monomer and other monomers are contained as copolymerized units.

In the graft copolymer of the first embodiment, as shown in FIG. 1, a side chain 2 of a polymerizable oligomer is bonded to a main chain having at least an alcoholic hydroxyl group 5 and a nitrogen atom 3 by graft copolymerization. The bonding portion 1 between the main chain and the side chain is formed as a result of a polymerization reaction by a terminal ethylenically unsaturated double bond in the polymerizable oligomer. The main chain and / or the side chain may contain the acidic monomer and other monomers as copolymerized units as necessary.

The graft copolymer according to the first aspect is characterized in that a terminal ethylenically unsaturated double bond in the polymerizable oligomer, an ethylenically unsaturated double bond in the nitrogen-containing monomer, and the polymerizable monomer It is formed by a polymerization reaction.

The content of these copolymer units in the graft copolymer of the first embodiment is 20 to 98% by weight, preferably 40 to 98% by weight of the polymerizable oligomer.
And the nitrogen-containing monomer is 1 to 40% by weight.
%, Preferably 5 to 30% by weight, and the polymerizable monomer was 1 to 40% by weight, preferably 5 to 30% by weight.
３０30% by weight.

When the content of the polymerizable oligomer is less than 20% by weight, a steric repulsion effect as a pigment dispersant cannot be obtained, and the aggregation of the pigment may not be prevented.
If the amount is more than 10% by weight, the proportion of the nitrogen-containing monomer is reduced, and the ability to adsorb the pigment is reduced, and the dispersibility may not be sufficient. When the content of the nitrogen-containing monomer is 1% by weight
If it is less than 40%, the adsorbing ability to the pigment may be reduced and the dispersibility may not be sufficient. In some cases, aggregation of the pigment cannot be sufficiently prevented. If the content of the polymerizable monomer is less than 1% by weight, the developability during the production of a color filter or the like may be insufficient, and if it exceeds 40% by weight, the ability as a pigment dispersant is reduced. Sometimes.

-Polymerizable oligomer- The polymerizable oligomer (hereinafter sometimes referred to as "macromonomer") is an oligomer having a group having an ethylenically unsaturated double bond at a terminal. In the present invention, among the polymerizable oligomers, it is preferable that only one of both ends of the oligomer has a group having the ethylenically unsaturated double bond.

The molecular weight of the polymerizable oligomer is as follows:
Polystyrene equivalent number average molecular weight (Mn) is 1000 to
It is preferably 10,000, and more preferably 2000 to 9000. The number average molecular weight is 1,000
If it is less than 3, the steric repulsion effect as a pigment dispersant may not be sufficient, and if it exceeds 10,000, it may take time to adsorb to the pigment due to the steric effect.

The oligomer is generally, for example, a homopolymer or a copolymer formed from at least one monomer selected from alkyl (meth) acrylate, styrene, acrylonitrile, vinyl acetate, and butadiene. And among these, homopolymers or copolymers of alkyl (meth) acrylates,
Polystyrene and the like are preferred. In the present invention, these oligomers may be substituted with a substituent, and the substituent is not particularly limited, and examples thereof include a halogen atom.

As the group having an ethylenically unsaturated double bond, for example, a (meth) acryloyl group, a vinyl group and the like are preferred, and among them, a (meth) acryloyl group is particularly preferred.

In the present invention, among the polymerizable oligomers, an oligomer represented by the following general formula (5) is preferable. General formula (5)

[0028]

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In the general formula (5), R ⁵¹ and R ⁵³
Represents a hydrogen atom or a methyl group. R ⁵² has 1 to 1 carbon atoms
Represents an alkylene group of 8, preferably an alkylene group having 2 to 4 carbon atoms, and particularly preferably an ethylene group. Y is a phenyl group, a phenyl group having an alkyl group having 1 to 4 carbon atoms,
Or —COOR ⁵⁴ (R ⁵⁴ represents an alcoholic hydroxyl group having 1 to 6 carbon atoms, an alkyl group optionally substituted by halogen, a phenyl group, or an arylalkyl group having 7 to 10 carbon atoms), and a phenyl group Or -COOR ⁵⁴ (R ⁵⁴ is
Represents an alkyl group which may be substituted by an alcoholic hydroxyl group having 1 to 4 carbon atoms). q represents 20 to 200.

Specific examples of the polymerizable oligomer include:
Poly-2hydroxyethyl (meth) acrylate, polystyrene polymer, polymethyl (meth) acrylate,
Preferable examples include poly-n-butyl (meth) acrylate, poly-i-butyl (meth) acrylate, and copolymers thereof, in which a (meth) acryloyl group is bonded to one molecular terminal.

The polymerizable oligomer may be a commercially available product or a product synthesized as appropriate. Examples of the commercially available product include a methacryloylated polystyrene oligomer having one end (Mn = 6000, trade name: AS-6, manufactured by Toagosei Chemical Industry Co., Ltd.), methacryloylated polymethyl methacrylate oligomer at one end (Mn = 6000,
Trade name: AA-6, manufactured by Toa Gosei Chemical Industry Co., Ltd.), methacryloylated poly-n-butyl acrylate oligomer at one end (Mn = 6000, trade name: AB-6, manufactured by Toa Gosei Chemical Industry Co., Ltd.), One-terminal methacryloylated polymethyl methacrylate / 2-hydroxyethyl methacrylate oligomer (Mn = 7000, trade name: AA-71)
4, Toa Gosei Chemical Industry Co., Ltd.), one-terminal methacryloylated polybutyl methacrylate / 2-hydroxyethyl methacrylate oligomer (Mn = 7000, trade name:
707S, manufactured by Toa Gosei Chemical Industry Co., Ltd.), methacryloylated poly-2-ethylhexyl methacrylate at one end / 2
-Hydroxyethyl methacrylate oligomer (Mn =
7000, Product name: AY-707S, AY-714S,
Toa Gosei Chemical Industry Co., Ltd.).

Preferred specific examples of the polymerizable oligomer in the present invention include at least one oligomer selected from a polymer of alkyl (meth) acrylate and a copolymer of alkyl (meth) acrylate and polystyrene. The number average molecular weight is 1000 to 100
00 and those having a (meth) acryloyl group at the terminal.

—Nitrogen-Containing Monomer— As the nitrogen-containing monomer, for example, at least one selected from compounds represented by the following general formula (1) is preferably exemplified. General formula (1)

[0034]

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In the general formula (1), R ¹¹ represents a hydrogen atom or a methyl group. R ¹² represents an alkylene group having 1 to 8 carbon atoms, and among them, an alkylene group having 1 to 6 carbon atoms is preferable, and an alkylene group having 2 to 3 carbon atoms is particularly preferable.

X ¹ is —N (R ¹³ ) (R ¹⁴ ), (R ¹³ and R ¹⁴ represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or a phenyl group), and —R ¹⁵ N (R ¹⁶⁾ (R ¹⁷⁾ (R
¹⁵ represents an alkylene group having 1 to 6 carbon atoms, R ¹⁶ and R
¹⁷ represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or a phenyl group), a pyrrolidino group, a pyrrolidyl group, a pyridyl group, a piperidino group or a morpholino group. Among ^{them, -N (R 13) (R} 14) or -R ¹⁵ -N (R ¹⁶⁾
(R ¹⁷ ) is preferable, and R ¹³ and R ¹⁴ of —N (R ¹³ ) (R ¹⁴ ) are preferably a hydrogen atom, an alkyl group having 1 to 4 carbon atoms or a phenyl group, and —R ¹⁵ —N (R ¹⁶ ) (R ¹⁷⁾
R ¹⁵ is preferably an alkylene group having 2 to 6 carbon atoms;
¹⁶ and R ¹⁷ are preferably an alkyl group having 1 to 4 carbon atoms.
Further, among the pyridyl groups, a 1-pyridyl group, a 2-pyridyl group,
Pyridyl group and the like are preferable, among the piperidino groups,
A 1-piperidino group and the like are preferable, among the pyrrolidyl groups, a 2-pyrrolidyl group and the like are preferable, and among the morpholino groups, a 4-morpholino group and the like are preferable. m and n
Represents 1 or 0, and m = 1 and n = 1, or m = 1
And n = 0 is preferable (that is, the following general formula (2):
(Corresponding to the compound represented by (3)).

In the present invention, among the compounds represented by the general formula (1), at least one selected from the compounds represented by any of the following general formulas (2) to (4) is preferable. General formula (2)

[0038]

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In the general formula (2), R ²¹ is R ¹¹
Is synonymous with R ²² has the same meaning as R ¹² . X ² is X ¹
Is synonymous with General formula (3)

[0040]

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In the general formula (3), R³¹Is R¹¹
Is synonymous with X^ThreeIs X¹Is synonymous with -N (R³³)
(R³⁴) (R³³And R³⁴Is R¹³And R¹⁴Synonymous with
Or -R³⁵−N (R³⁶) (R³⁷) (R³⁵, R³⁶
And R³⁷Is R¹⁵, R ¹⁶And R¹⁷Synonymous with
Is preferred. General formula (4)

[0042]

Embedded image

In the general formula (4), R ³¹ is R ¹¹
Is synonymous with X ⁴ is a pyrrolidino group, a pyrrolidyl group,
Represents a pyridyl group, a piperidino group or a morpholino group.

Specific examples of the compound represented by the general formula (1) include N, N-dimethylaminoethyl (meth) acrylate and N, N-dimethylaminopropyl (meth).
Acrylate, 1- (N, N-dimethylamino) -1,
1-dimethylmethyl (meth) acrylate, N, N-dimethylaminohexyl (meth) acrylate, N, N-
Diethylaminoethyl (meth) acrylate, N, N-
Diisopropylaminoethyl (meth) acrylate,
N, N-di-n-butylaminoethyl (meth) acrylate, N, N-di-i-butylaminoethyl (meth) acrylate, morpholinoethyl (meth) acrylate,
Piperidinoethyl (meth) acrylate, 1-pyrrolidinoethyl (meth) acrylate, N, N-methyl-2-
Pyrrolidylaminoethyl (meth) acrylate and N,
N-methylphenylaminoethyl (meth) acrylate (the above (meth) acrylates);

Dimethyl (meth) acrylamide, diethyl (meth) acrylamide, diisopropyl (meth) acrylamide, di-n-butyl (meth) acrylamide, di-i-butyl (meth) acrylamide, morpholino (meth) acrylamide, piperidino (meth) ) Acrylamide, N-methyl-2-pyrrolidyl (meth) acrylamide and N, N-methylphenyl (meth) acrylamide (above (meth) acrylamides);

2- (N, N-dimethylamino) ethyl (meth) acrylamide, 2- (N, N-diethylamino) ethyl (meth) acrylamide, 3- (N, N-diethylamino) propyl (meth) acrylamide, −
(N, N-dimethylamino) propyl (meth) acrylamide, 1- (N, N-dimethylamino) -1,1-dimethylmethyl (meth) acrylamide and 6- (N, N
-Diethylamino) hexyl (meth) acrylamide (above aminoalkyl (meth) acrylamides); and vinylpyridine.

—Polymerizable Monomer— The polymerizable monomer is not particularly limited as long as it has an alcoholic hydroxyl group and is polymerizable, and can be appropriately selected from known ones. Examples thereof include hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, polyethylene glycol mono (meth) acrylate, and polypropylene glycol mono (meth) acrylate.

The content of the alcoholic hydroxyl group in the polymerizable monomer is, for example, 1 to 30% by weight.
Is preferred. When the content is less than 1% by weight, sufficient developability may not be obtained in the production of a color filter or the like. When the content is more than 30% by weight, the proportion of other components decreases, and the pigment dispersant May not be enough.

Second Embodiment The graft copolymer according to the second embodiment has a polymerizable oligomer having an alcoholic hydroxyl group and having an ethylenically unsaturated double bond at a terminal, a nitrogen atom and an ethylenically unsaturated double bond. A nitrogen-containing monomer having a saturated double bond and at least a copolymer unit, if necessary, the acidic monomer,
Other monomers are included as copolymerized units.

As shown in FIG. 2, the graft copolymer of the second embodiment has a main chain having at least a nitrogen atom 3
A side chain 2 of a polymerizable oligomer having at least an alcoholic hydroxyl group 5 is bonded by graft copolymerization, and a bonding portion 1 between the main chain and the side chain is a terminal ethylenically unsaturated double bond in the polymerizable oligomer. Resulting from the polymerization reaction of The main chain and / or the side chain may contain the acidic monomer and other monomers as copolymerized units as necessary.

The graft copolymer according to the second embodiment is formed by a polymerization reaction between a terminal ethylenically unsaturated double bond in the polymerizable oligomer and an ethylenically unsaturated double bond in the nitrogen-containing monomer. .

The content of these copolymer units in the graft copolymer of the second embodiment is 20 to 99% by weight of the polymerizable oligomer, preferably 70 to 99% by weight.
And the nitrogen-containing monomer is 1 to 80% by weight.
%, Preferably 5 to 30% by weight. When the content of the polymerizable oligomer is less than 20% by weight, the proportion of the nitrogen-containing monomer is reduced, the adsorption ability to the pigment is reduced, and the dispersibility may be insufficient.
If it exceeds 9% by weight, the ability to adsorb the pigment decreases,
Dispersibility may not be enough. When the content of the nitrogen-containing monomer is less than 1% by weight, the ratio of the polymerizable oligomer is reduced, a steric repulsion effect as a dispersant is not obtained, and aggregation of the pigment may not be sufficiently prevented, 8
If the content exceeds 0% by weight, the ability to adsorb the pigment may be reduced, and the dispersibility may not be sufficient.

—Polymerizable Oligomer— As the polymerizable oligomer in the second embodiment, except that the polymerizable oligomer contains an alcoholic hydroxyl group (except that it is substituted with an alcoholic hydroxyl group), It is the same as the polymerizable oligomer in the embodiment.

The content of the alcoholic hydroxyl group in the polymerizable oligomer is preferably, for example, 5 to 99% by weight. When the content is less than 5% by weight,
In some cases, the suitability for development during the production of a color filter or the like may not be obtained. If the content exceeds 99% by weight, the solubility of the developer during the production of the color filter or the like may be improved, and control may be difficult. .

—Nitrogen-Containing Monomer— The nitrogen-containing monomer in the second embodiment is the same as the nitrogen-containing monomer in the first embodiment.

—Acid Monomer— The graft copolymer may further contain an acidic monomer as a copolymer unit. The acidic monomer can be appropriately selected according to the purpose. Acrylic acid, methacrylic acid, crotonic acid, itaconic acid, maleic acid, unsaturated carboxylic acids such as fumaric acid, and the like, among them, acrylic acid, methacrylic acid in that solubility, dispersibility and the like are improved. preferable.

The content of the acidic monomer in the graft copolymer is preferably from 1 to 30% by weight. If the content is less than 1% by weight, developability during production of a color filter or the like may not be obtained, and 30
If the amount is more than 10% by weight, it may act with the nitrogen-containing monomer to be copolymerized, and a pigment dispersant having excellent dispersibility may not be obtained.

-Other Monomer- The graft copolymer may further contain the other monomer as a copolymer unit, and the other monomer is not particularly limited and may be appropriately selected depending on the purpose. For example, aromatic vinyl compounds (eg, styrene, α-methylstyrene and vinyltoluene), alkyl (meth) acrylates (eg, methyl (meth) acrylate, ethyl (meth) acrylate, n -Butyl (meth) acrylate and i-butyl (meth) acrylate), alkylaryl (meth) acrylate (eg, benzyl (meth) acrylate), glycidyl (meth) acrylate, vinyl carboxylate (eg, vinyl acetate and Vinyl propionate), vinyl cyanide (eg, (meth) acryloni Lil and α- chloro acrylonitrile), and aliphatic conjugated dienes (e.g., 1,3-butadiene and isoprene), and the like. Among these, unsaturated carboxylic acids,
Alkyl (meth) acrylate, alkylaryl (meth) acrylate and vinyl carboxylate are preferred.

The content of the other monomer in the graft copolymer is preferably, for example, 5 to 70% by weight. If the content is less than 5% by weight, it may be impossible to control the physical properties of the coating film.
If it exceeds 30, the ability as a pigment dispersant may not be sufficiently exhibited.

Preferred specific examples of the graft copolymer include (1) dimethylaminoethyl (meth) acrylate / 2-hydroxyethyl (meth) acrylate /
(2) dimethylaminoethyl (meth) acrylate / 2-hydroxypropyl (meth) acrylate / methacryloly terminated polymethyl (meth) acrylate copolymer, (3) diethylaminoethyl ( (Meth) acrylate / 2-hydroxyethyl (meth) acrylate / terminal methacryloylated polymethyl (meth) acrylate copolymer, (4) di-n-butylaminoethyl (meth) acrylate / 2-hydroxyethyl (meth)
Acrylate / terminal methacryloylated polymethyl (meth) acrylate copolymer, (5) di-n-butylaminoethyl (meth) acrylate / 2-hydroxyethyl (meth) acrylate / terminal methacryloylated polystyrene copolymer, (6) dimethyl Aminoethyl (meth) acrylate / 2-hydroxyethyl (meth) acrylate / terminal methacryloylated polystyrene copolymer, (7) dimethylaminoethyl (meth) acrylate / 2-hydroxyethyl (meth) acrylate / methyl (meth) acrylate / Terminal methacryloylated polystyrene copolymer, (8) dimethylaminoethyl (meth) acrylate / 2-hydroxyethyl (meth) acrylate / benzyl (meth) acrylate / terminal methacryloylated polystyrene copolymer (9) dimethylaminoethyl (meth) acrylate / polypropylene glycol mono (meth) acrylate / terminally methacryloylated polymethyl (meth) acrylate copolymer,

(10) vinylpyridine / 2-hydroxyethyl (meth) acrylate / terminally methacryloylated polymethyl (meth) acrylate copolymer, (11) N,
N-dimethyl-2-piperidylethyl acrylate / 2
-Hydroxyethyl (meth) acrylate / terminally methacryloylated polymethyl (meth) acrylate copolymer,
(13) 4-morpholinoethyl acrylate / 2-hydroxyethyl (meth) acrylate / terminally methacryloylated polymethyl (meth) acrylate copolymer, (14)
3- (N, N-dimethylamino) propylacrylamide / 2-hydroxyethyl (meth) acrylate / terminal methacryloylated polymethyl (meth) acrylate copolymer, (15) 3- (N, N-dimethylamino) propylacrylamide / 2-hydroxyethyl (meth) acrylate / terminal methacryloylated polystyrene copolymer, (16) 3- (N, N-dimethylamino) propylacrylamide / 2-hydroxyethyl (meth) acrylate / methyl (meth) acrylate terminal methacryloylation Polystyrene copolymer, (17) copolymer of 3- (N, N-dimethylamino) propylacrylamide / 2-hydroxyethyl (meth) acrylate / terminally methacryloylated methyl (meth) acrylate and 2-hydroxyethyl methacrylate Copolymer, (18) 3-
(N, N-dimethylamino) propylacrylamide /
(19) 3- (N, N) copolymer of benzyl meth) acrylate / copolymer of terminal methacryloylated methyl methacrylate and 2-hydroxyethyl methacrylate
-Dimethylamino) propylacrylamide / copolymer of a copolymer of terminal methacryloylated methyl methacrylate and 2-hydroxyethyl methacrylate, and the like.

The above-mentioned graft copolymer can be obtained by, for example, radically polymerizing the components to become the above-mentioned respective copolymer units in a solvent. During the radical polymerization,
A radical polymerization initiator can be used, and further, a chain transfer agent (eg, 2-mercaptoethanol and dodecylmercaptan) can be used. Hereinafter, some examples of the synthesis of the graft copolymer will be described.

[Synthesis Example 1] 15 parts by weight of 1-methoxy-2-propyl acetate was introduced into a three-necked flask purged with nitrogen, stirred by a three-one motor, and heated while flowing nitrogen into the flask. The temperature was raised to ° C. The separately prepared monomer solution and initiator solution described below were simultaneously added dropwise over 2 hours and 15 minutes. (Monomer solution) Dimethylaminoethyl acrylate 4.5 parts by weight Having a methacryloyl group at one end 23.8 parts by weight Polymethyl methacrylate (number average molecular weight: 6000, macromonomer AA -6, manufactured by Toa Gosei Chemical Industry Co., Ltd.) 2-hydroxyethyl acrylate: 1.7 parts by weight 1-methoxy-2-propyl acetate: 45 parts by weight (initiator solution) 2,2-azobis (2,4-dimethylvaleronitrile) 0.04 parts by weight (trade name: V-65, manufactured by Wako Pure Chemical Industries, Ltd.) 1-methoxy-2- Propyl acetate 9.6 parts by weight

After the dropwise addition, 0.08 parts by weight of 2,2-azobis (2,4-dimethylvaleronitrile) (trade name: V-65) was added to the solution in the flask, and the temperature in the flask was reduced to 78 ° C. Hold for 3 hours, then heat to 90 ° C for 30
Hold for a minute. Next, the solution in the flask was cooled to room temperature to obtain a solution of the graft copolymer. The solution of the graft copolymer had a solid content of 30% by weight and a polymerization yield of 9%.
8%. The weight average molecular weight of the obtained graft copolymer was 20,000. The weight average molecular weight was measured by gel permeation chromatography (C-R4
A, manufactured by Shimadzu Corporation).

[Synthesis Example 2] In Synthesis Example 1, 2-
The procedure was the same as in Synthesis Example 1 except that hydroxyethyl acrylate was replaced with 2-hydroxyethyl methacrylate. The obtained graft copolymer solution has a solid content of 3
At 0% by weight, the polymerization yield was 98%. The weight average molecular weight of the obtained graft copolymer was 20,000.

Synthesis Example 3 In Synthesis Example 1, 4.5 parts by weight of dimethylaminoethyl acrylate, polymethyl methacrylate having a methacryloyl group at one end (number average molecular weight: 6000, macromonomer AA-
6, Toa Gosei Chemical Industry Co., Ltd.) and the same procedures as in Synthesis Example 1 except that 22.1 parts by weight of 2-hydroxyethyl acrylate and 3.4 parts by weight of 2-hydroxyethyl acrylate were used. The solution of the obtained graft copolymer had a solid content of 30% by weight and a polymerization yield of 98%. The weight average molecular weight of the obtained graft copolymer was 20,000.

[Synthesis Example 4] The procedure of Synthesis Example 1 was repeated except that dimethylaminoethyl acrylate was replaced with 3- (N, N-dimethylamino) propylacrylamide. The solution of the obtained graft copolymer had a solid content of 30% by weight and a polymerization yield of 98%. The weight average molecular weight of the obtained graft copolymer is 2
0000.

[Synthesis Example 5] In Synthesis Example 3, 2-
Hydroxyethyl acrylate and polymethyl methacrylate having a methacryloyl group at one end are combined with methyl methacrylate / 2-hydroxyethyl methacrylate having a methacryloyl group at one end (number average molecular weight: 7000, macromonomer AA-714, Toa Gosei) The same procedure as in Synthesis Example 3 was performed except that the amount was changed to 25.5 parts by weight (manufactured by Chemical Industry Co., Ltd.). The solution of the obtained graft copolymer had a solid content of 30% by weight and a polymerization yield of 98%. The weight average molecular weight of the obtained graft copolymer is
20,000.

The pigment dispersant of the present invention may contain only the above-mentioned graft copolymer, or may further contain other components appropriately selected as necessary. Examples of the other components include known dispersants, and specifically, nonanoamide, decanamide, dodecaneamide, N
-Dodecylhexadecaneamide, N-octadecylpropioamide, N, N-dimethyldodecaneamide and N,
Amide compounds such as N-dihexylacetamide, amine compounds such as diethylamine, diheptylamine, dibutylhexadecylamine, N, N, N ', N'-tetramethylmethanamine, triethylamine, tributylamine and trioctylamine, monoethanol Amine,
Diethanolamine, triethanolamine, N, N,
N ', N'-(tetrahydroxyethyl) -1,2-diaminoethane, N, N, N'-tri (hydroxyethyl) -1,2-diaminoethane, N, N, N ', N'-
Tetra (hydroxyethylpolyoxyethylene) -1,
Amines having a hydroxy group such as 2-diaminoethane, 1,4-bis (2-hydroxyethyl) piperazine and 1- (2-hydroxyethyl) piperazici, and other compounds such as pecotamide, isonipecotamide, and nicotinamide. No. These may be commercially available products or may be synthesized as appropriate. Examples of the commercially available products include Shigenox-105 (trade name, manufactured by Hakkor Chemical Co., Ltd.).

The content of the other components in the pigment dispersant is preferably from 1 to 90% by weight, and from 1 to 7% by weight.
0% by weight is more preferred. When the content is less than 1% by weight, the increase in viscosity of the pigment dispersion composition may not be suppressed, and when it exceeds 90% by weight, the performance as a pigment dispersant may not be sufficiently exhibited.

Further, the pigment dispersant of the present invention may further contain an amine compound represented by the following general formula (6) or (7). General formula (6)

[0072]

Embedded image

In the general formula (6), R ⁶¹ and R ⁶²
Represents a hydrogen atom, an alkyl group or an aralkyl group which may have a substituent, and these may be bonded to each other to form a 5- or 6-membered saturated ring containing a nitrogen atom. This saturated ring may further contain 1 to 3 atoms selected from an oxygen atom, a sulfur atom and a nitrogen atom. R
⁶³ represents an alkylene group or an alkylene group containing an ether bond. X ⁶ represents —CON (Y ⁶¹ ) (Y ⁶² ), —O
CON (Y ⁶¹ ) (Y ⁶² ), -N (Y ⁶³ ) CO (Y ⁶⁴ ),
Or, it represents -N (Y ⁶³ ) CON (Y ⁶¹ ) (Y ⁶² ). Y
⁶¹ , Y ⁶² , Y ⁶³ and Y ⁶⁴ represent a hydrogen atom or an alkyl group, an aralkyl group or an aryl group which may have a substituent. General formula (7)

[0074]

Embedded image

In the general formula (7), R ⁷¹ , R ⁷² ,
R ⁷⁶ and R ^{77 each} represent a hydrogen atom or an alkyl group or an aralkyl group which may have a substituent, and these are combined with each other to form a 5- or 6-membered saturated ring containing a nitrogen atom. You may. This saturated ring may further contain 1 to 3 atoms selected from an oxygen atom, a sulfur atom and a nitrogen atom. R ⁷⁴ and R ^{75 each} represent an alkylene group or an alkylene group having an ether bond. Z ⁷ is -CON
^{(Y 71) -, - OCON} (Y 71) - or -N (Y ^{7 2)} C
ON (Y ⁷³ )-. Y ⁷¹ , Y ⁷² and Y ⁷³ have the same meaning as Y ⁶¹ , Y ⁶² and Y ⁶³ in the general formula (6) in this order.

Specific examples of the amine compound represented by the general formula (6) or (7) include bis (2- (1-morpholino) ethyl) terephthalamide.

Further, the pigment dispersant of the present invention may contain various surfactants, and if the surfactant is contained, it is effective for improving the dispersion stability. Examples of the surfactant include an anionic surfactant represented by an alkylnaphthalene sulfonate and a phosphoric acid ester salt, a cationic surfactant represented by an amine salt, an aminocarboxylic acid, and a betaine type. And an amphoteric surfactant.

—Dispersion— Next, the dispersion of the pigment by the pigment dispersant of the present invention will be described with reference to the drawings. FIG. 3 is a schematic explanatory view showing a state where the pigment dispersant containing the graft copolymer of the first embodiment is adsorbed on the surface of the pigment particles. FIG. 4 is a schematic explanatory view showing a state where the pigment dispersant containing the graft copolymer of the second embodiment is adsorbed on the surface of the pigment particles.

As shown in FIGS. 3 and 4, when the pigment dispersant of the present invention is used, the pigment dispersant is adsorbed on the surface of the pigment particles 1. At this time, nitrogen atoms 3 existing in the main chain of the graft copolymer in the pigment dispersant are adsorbed on the surface of the pigment particles 1. The pigment particles 1 are covered with the main chain of the graft copolymer. A side chain 2 is branched from the main chain, and the side chain 2 extends outward from the surface of the pigment particle 1 and exists as if a cloud covers the periphery of the pigment particle 1. ing. Since the graft copolymer is adsorbed on the surfaces of the individual pigment particles 1, the pigment particles 1 do not adsorb to each other and agglomerate. It becomes dispersed and easily flowable.

When a general pigment dispersant is used in the colored photosensitive composition, the acidic group in the binder polymer having an acidic group contained in the colored photosensitive composition and the nitrogen atom in the pigment dispersant are used. Often form a salt or bond with a strong intermolecular force. In the case of the pigment dispersant of the present invention, the presence of the side chain 2 in the graft copolymer causes such a salt. While suppressing the behavior, the stability after dispersion can be improved, and the effect of improving dispersibility by nitrogen atoms can be enhanced. Further, according to the graft copolymer, when the organic pigment is dispersed, the organic pigment does not increase in viscosity and the dispersibility of the organic pigment is good, and particularly, the dispersibility of an acidic organic pigment is good.

Dispersion by the pigment dispersant of the present invention means that pigment particles generally present in the form of secondary particles are loosened to form primary particles, thereby preventing reaggregation. The pigment dispersant of the present invention is a graft-type dispersant having a site for adsorption to the pigment and a steric repulsion site for preventing re-aggregation after the pigment is dispersed in the form of primary particles. Even so, it exhibits a sufficiently excellent dispersing effect. The dispersion of the pigment by the pigment dispersant of the present invention can be effectively achieved by directly mixing the pigment dispersant with the pigment, and is preferably performed in a state in which particles that can be dispersed other than the pigment are present as little as possible. When the pigment is dispersed in such a state, the pigment dispersant of the present invention is instantly adsorbed around the pigment particles, and the pigment particles are well dispersed and flow well. Is effectively suppressed. On the other hand, when the pigment is dispersed in a state in which particles other than the pigment particles can be dispersed,
The pigment dispersant of the present invention is not adsorbed on the surface of the target pigment particles, but is adsorbed on other particle surfaces, and the pigment dispersing effect of the pigment dispersant may be impaired. Therefore, for example, in the case of producing a photosensitive material or the like, in order to allow the pigment to be contained in the photosensitive material or the like in a well dispersed state, the pigment and the pigment dispersant of the present invention are mixed at an early stage. It is preferable to add and mix the pigment dispersant of the present invention at a later time, such as when preparing a coating solution for a photosensitive layer.

The pigment dispersant of the present invention can be suitably used for dispersing known pigments, and can be particularly preferably used for the pigment dispersion composition and the colored photosensitive composition of the present invention described later.

<< Pigment Dispersion Composition >> The pigment dispersion of the present invention is obtained by dispersing the pigment dispersant of the present invention and a pigment in an organic solvent.

—Pigment— Examples of the pigment include organic pigments. Examples of the organic pigment include a yellow pigment, an orange pigment, a red pigment, a violet pigment, a blue pigment, a green pigment, a brown pigment, a black pigment, and the like.

Examples of the yellow pigment include C.I. I.
Pigment Yellow 20, C.I. I. Pigment Yellow 24, C.I. I. Pigment Yellow 12, C.I. Pigment Yellow 17, C.I. I. Pigment Yellow 83,
C. I. Pigment Yellow 86, C.I. I. Pigment Yellow 93, C.I. I. Pigment Yellow 109,
C. I. Pigment yellow 110, C.I. I. Pigment Yellow 117, C.I. I. Pigment Yellow 12
5, C.I. I. Pigment yellow 137, C.I. I. Pigment yellow 138, C.I. I. Pigment Yellow 1
39, C.I. I. Pigment Yellow 185, C.I. I. Pigment yellow 147, C.I. I. Pigment yellow 148, C.I. Pigment Yellow 153, C.I. I. Pigment yellow, C.I. I. Pigment Yellow 15
4, C.I. I. Pigment yellow 166, C.I. I. Pigment yellow 168, C.I. I. Pigment Yellow 1
85, and the like.

Examples of the orange pigment include C.I.
I. Pigment Orange 36, C.I. I. Pigment Orange 43, C.I. I. Pigment Orange 51, C.I. I.
Pigment Orange 55, C.I. I. Pigment Orange 59, C.I. I. Pigment Orange 61, C.I. I. Pigment Orange 71, and the like.

Examples of the red pigment include C.I. I.
Pigment Red 9, C.I. I. Pigment Red 97,
C. I. Pigment Red 122, C.I. I. Pigment Red 123, C.I. I. Pigment Red 149, C.I.
I. Pigment Red 168, C.I. I. Pigment Red 177, C.I. I. Pigment Red 180, C.I. I.
Pigment Red 192, C.I. I. Pigment Red 2
15, C.I. I. Pigment Red 216, C.I. I. Pigment Red 217, C.I. I. Pigment Red 22
0, C.I. I. Pigment Red 223, C.I. I. Pigment Red 224, C.I. I. Pigment Red 226,
C. I. Pigment Red 227, C.I. I. Pigment Red 228, C.I. I. Pigment Red 240, C.I.
I. Pigment Red 48: 1, C.I. I. Pigment Red 209, C.I. I. Pigment Red 146, C.I.
I. Pigment Red 11, C.I. I. Pigment Red 81, C.I. I. Pigment Red 123, C.I. I. Pigment Red 213, C.I. I. Pigment Red 27
2, C.I. I. Pigment Red 270, C.I. I. Pigment Red 255, C.I. I. Pigment Red 264,
C. I. Pigment Red 254, and the like.

Examples of the violet pigment include:
C. I. Pigment Violet 19, C.I. I. Pigment Violet 23, C.I. I. Pigment Violet 29, C.I. I. Pigment Violet 30, C.I.
I. Pigment Violet 37, C.I. I. Pigmented Violet 40, C.I. I. Pigment Violet 5
0, and the like.

Examples of the blue pigment include C.I. I.
Pigment Blue 15, C.I. I. Pigment Blue 1
5: 6, C.I. I. Pigment Blue 22, C, I.P. Pigment Blue 60, C.I. I. Pigment Blue 64, and the like.

Examples of the green pigment include C.I. I.
Pigment Green 7, C.I. I. Pigment Green 3
6, and the like. Examples of the brown pigment include C.I. I. Pigment Brown 23, C.I. I. Pigment Brown 25, C.I. I. Pigment Brown 2
6, and the like. Examples of the black pigment include C.I. I. Pigment Black 7, and the like.

These pigments may be used alone or in combination of two or more. In the present invention, among these, pigments having an acidic group such as Pigment Yellow 138, Pigment Yellow 139, Pigment Yellow 185, and Pigment Yellow 83 are preferable, and Pigment Yellow 138 and Pigment Yellow 1 are preferable.
39, Pigment Yellow 185, Pigment Red 2
54, Pigment Green 36, Pigment Blue 15
Etc. are particularly preferred.

—Organic Solvent— The organic solvent is not particularly limited and can be appropriately selected from known ones. For example, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol (Poly) alkylene glycol monoalkyl ethers such as monoethyl ether, diethylene glycol monomethyl ether, ethylene glycol monoethyl ether and the like and acetates thereof;
Acetates such as ethyl acetate, n-propyl acetate, i-propyl acetate, n-butyl acetate and i-butyl acetate; aromatic hydrocarbons such as benzene, toluene and xylene;
Ketones such as methyl ethyl ketone, acetone, methyl isobutyl ketone and cyclohexanone; ethanol, propanol, butanol, hexanol, cyclohexanol, ethylene glycol, diethylene glycol,
Alcohols such as glycerin and the like. These may be used alone or in combination of two or more. Among these, alkylene glycol monoalkyl ethers, and their acetates, acetates, and methyl ethyl ketone are preferred.

The content of the pigment in the pigment dispersion composition is usually 5 to 80% by weight, and 10 to 70% by weight.
% By weight is preferred. If the content is less than 5% by weight, the coloring power may not be sufficient, and if it exceeds 80% by weight, the viscosity of the pigment dispersion composition may increase.

The content of the pigment dispersant in the pigment dispersion composition is usually 0.1 to 200 parts by weight, preferably 1 to 50 parts by weight, per 100 parts by weight of the pigment. When the content is less than 0.1 part by weight, the viscosity of the pigment dispersion composition may increase.When the content is more than 200 parts by weight, at the time of producing a color filter or the like, to obtain chromaticity. It may be difficult to adjust the thickness of the coating film.

The content of the organic solvent in the pigment dispersion composition is usually 10 to 1000 parts by weight, preferably 20 to 500 parts by weight, based on 100 parts by weight of the pigment. When the content is less than 10 parts by weight,
The viscosity of the pigment dispersion composition may increase,
Exceeding the weight parts may make it difficult to secure a space for storage.

The pigment dispersion composition of the present invention can be prepared, for example, by the following method. 1) A method in which a composition obtained by previously mixing the pigment and the pigment dispersant is added to and dispersed in the organic solvent (or vehicle). 2) The pigment and the pigment are dispersed in the organic solvent (or vehicle). A method of separately adding and dispersing a pigment dispersant 3) a method of previously dispersing the pigment and the pigment dispersant separately in the organic solvent (or vehicle) and mixing the obtained dispersion (in this case, 4) A method of dispersing the pigment in the organic solvent (or vehicle) and then adding the pigment dispersant to the resulting dispersion.

The vehicle refers to a portion of a medium in which the pigment is dispersed when the paint is in a liquid state, and a component (binder) which is in a liquid state and binds to the pigment to solidify a coating film. And a component to be dissolved and diluted (the organic solvent).

The disperser used for dispersing the pigment is not particularly limited, and examples thereof include known dispersers such as a kneader, a roll mill, an attritor, a super mill, a dissolver, a homomixer, and a sand mill.

For forming a colored image using the pigment dispersion composition, for example, a coating solution containing the pigment dispersion composition is applied on a support and dried to form a layer of the pigment dispersion composition.
Alternatively, the layer of the pigment dispersion composition formed on the temporary support is transferred onto the support, and a layer of a known positive or negative photosensitive resin composition is formed thereon, and exposed and developed. Then, a method of removing the layer of the pigment dispersion composition in the same region together with the unexposed layer of the photosensitive resin composition can be used.

<< Colored Photosensitive Composition >> The colored photosensitive composition contains at least the pigment dispersion composition and the photosensitive composition.

—Photosensitive Composition— As the photosensitive composition, for example, JP-A-3-282
No. 404, specifically, a photosensitive composition comprising a negative-type diazo resin and a binder, a photopolymerizable composition, and a photosensitive composition comprising an azide compound and a binder. Composition, cinnamic acid type photosensitive composition,
And the like. As the photosensitive composition, those which can be developed with an aqueous alkali solution and those which can be developed with an organic solvent are known. Pollution prevention, those which can be developed with an alkaline aqueous solution in terms of labor safety and the like are known. preferable.

—Photopolymerizable Composition— In the present invention, a photopolymerizable composition is particularly preferable among the photosensitive compositions. The photopolymerizable composition contains at least a binder polymer having an acidic group, a polyfunctional monomer having two or more ethylenically unsaturated double bonds, and a photopolymerization initiator.

—Binder Polymer Having Acidic Group—
-The binder polymer having an acidic group can impart both the dispersion stability of the pigment and the alkali developability, and for example, a copolymer of (meth) acrylic acid and (meth) acrylate Polymers, styrene / maleic anhydride copolymers, and reaction products of styrene / maleic anhydride copolymers with alcohols, and the like. These may be used alone or in combination of two or more. Among them, those having excellent pigment dispersibility, excellent compatibility with polyfunctional monomers and photopolymerization initiators, and those having appropriate alkali developer solubility, organic solvent solubility, strength, softening temperature, etc. are preferable, and Specifically, a copolymer of (meth) acrylic acid and (meth) acrylate is preferred.

The weight average molecular weight of the binder polymer having an acidic group is preferably 5,000 to 200,000. When the weight average molecular weight is less than 5000, there may be a problem in forming a coating film,
If it exceeds 0, the viscosity of the colored photosensitive composition may increase.

The content of the acidic group-containing binder polymer in the colored photosensitive composition is about 20 to 80% by weight based on the total solid content. If the content is less than 20% by weight, there may be a problem in forming a coating film, and if the content is more than 80% by weight, the performance of other materials may be difficult to exert.

--Polyfunctional monomer having two or more ethylenically unsaturated double bonds-- Examples of the polyfunctional monomer having two or more ethylenically unsaturated double bonds include, for example, JP-A-60-258538.
(Meth) acrylate, urethane (meth) acrylate, (meth)
Acrylic amides, allyl compounds, vinyl esters and the like can be mentioned. These may be used alone or in combination of two or more. Among these, (meth) acrylates are preferred.

The content of the polyfunctional monomer having an ethylenically unsaturated double bond in the colored photosensitive composition is preferably from 10 to 60% by weight based on the total solid content. If the content is less than 10% by weight, the curing power at the time of exposure may be insufficient, and if it is more than 60% by weight, the performance of other materials may be difficult to exert.

—Photopolymerization Initiator— The photopolymerization initiator has a wavelength of about 300 to 500 n.
It is preferable to use at least one compound having a molecular extinction coefficient of at least about 50 in m. Examples of such a compound include JP-A-2-48664, JP-A-1-152449, and JP-A-1-152449. 2-1533
No. 53, aromatic ketones,
Lophine dimer, benzoin, benzoin ethers,
And polyhalogens. These may be used alone or in combination of two or more. Among them, a combination of 4,4′-bis (diethylamino) benzophenone and 2- (o-chlorophenyl) -4,5-diphenylimidazole dimer, and
[P-N, N-di (ethoxycarbonylmethyl) -2,
6-di (trichloromethyl) -s-triazine].

The content of the photopolymerization initiator in the colored photosensitive composition is preferably from 0.2 to 10% by weight based on the solid content of the colored photosensitive composition. The content is
If it is less than 0.2% by weight, the exposure sensitivity may be low, and if it exceeds 10% by weight, the exposure sensitivity may be too high (control may be difficult).

The colored photosensitive composition can be prepared, for example, by mixing the pigment dispersion composition and the photosensitive composition according to appropriately selected conditions and techniques.

The formation of a colored image using the colored photosensitive composition can be basically performed by the following steps (1) to (3). (1) After preparing the pigment dispersion composition, using the same to prepare the colored photosensitive composition (2) coating the obtained colored photosensitive composition on a substrate and drying, or Step of transferring a layer formed by coating and drying on another temporary support onto a substrate to form a layer of a colored photosensitive composition (3) Layer of a colored photosensitive composition formed on a substrate For exposing and developing a pattern to form a pattern

The production of a color filter used for a liquid crystal display or the like can be performed by repeating the above steps (2) and (3) and combining the patterns of the second and subsequent colors. A method for producing a color filter by a transfer method is described in, for example, JP-A-4-208940, JP-A-5-72724, JP-A-5-80503, and JP-A-5-173320.

As the substrate, a transparent material such as a glass plate or a transparent plastic plate is generally used. In order to improve the adhesion between the substrate and the colored photosensitive composition, various commercially available silane coupling agents or the like are added to the colored photosensitive composition, or the substrate is subjected to a coupling treatment in advance. May be.

The application of the coating solution of the colored photosensitive composition to the substrate can be performed by using a known coating means such as a spin coater, a roll coater, a bar coater, and a curtain coater.

As a method for transferring the layer of the colored photosensitive composition formed on the temporary support onto the substrate, a method using a heat roll laminator under normal pressure or reduced pressure is preferable.

Examples of the developing solution used in the development include hydroxides or carbonates of alkali metals or alkaline earth metals, hydrogen carbonates, asymonia water, and aqueous solutions of quaternary ammonium salts. Can be These may be used alone or in combination of two or more. Among these, an aqueous solution of sodium carbonate is particularly preferred.

[0117]

EXAMPLES Examples of the present invention will be described below.
The present invention is not limited by these examples.

Example 1 A red pigment dispersion composition having the following composition was prepared. C. I. Pigment Red 254 8.28 g Pigment dispersant of Synthesis Example 1 8.28 g 1-methoxy-2-propyl acetate・ ・ 63.44g

The red pigment composition having the above composition was dispersed in a motor mill M50 (manufactured by Eiger) using zirconia beads having a diameter of 0.65 mm at a peripheral speed of 9 m / s for 9 hours.
A red pigment dispersion composition was prepared.

The obtained pigment dispersion composition was evaluated as follows. (1) Viscosity measurement: For the obtained pigment dispersion composition,
The viscosity was measured using a type viscometer, and the degree of thickening was evaluated. The results are shown in Table 1.

(2) Contrast measurement: The obtained pigment dispersion composition was applied on a glass substrate so as to have a thickness of 6 μm to prepare a sample. This sample was placed between two polarizing plates, the amount of transmitted light when the polarization axis was parallel and when the polarization axis was perpendicular was measured, and the ratio was defined as the contrast (“19”).
1990 7th Color Optics Conference, 512 color display 1
0.4 "size color filter for TFT-LCD, Ueki, Koseki, Fukunaga, Yamanaka"). The results are shown in Table 1.

Example 2 A red pigment dispersion composition was prepared in the same manner as in Example 1 except that the pigment dispersant of Synthesis Example 1 was replaced with the pigment dispersant of Synthesis Example 2. It was prepared and evaluated in the same manner as in Example 1.

Example 3 A red pigment dispersion composition was prepared in the same manner as in Example 1 except that the pigment dispersant of Synthesis Example 1 was replaced with the pigment dispersant of Synthesis Example 3. It was prepared and evaluated in the same manner as in Example 1.

Example 4 A red pigment dispersion composition was prepared in the same manner as in Example 1 except that the pigment dispersant of Synthesis Example 1 was replaced with the pigment dispersant of Synthesis Example 4. It was prepared and evaluated in the same manner as in Example 1.

(Example 5) In Example 1, the pigment dispersant of Synthesis Example 1 was replaced with the pigment dispersant of Synthesis Example 5 except that
C. I. Pigment Red-254, C.I. I. Pigment Yellow 13 except that Pigment Yellow 13 was used, a yellow pigment dispersion composition was prepared in the same manner as in Example 1, and the same evaluation as in Example 1 was performed.

Example 6 A green pigment dispersion composition was prepared in the same manner as in Example 1 except that the red pigment dispersion composition was replaced with a green pigment dispersion composition having the following composition. Then, the same evaluation as in Example 1 was performed. C. I. Pigment Green 36 9.20 g C.I. I. Pigment Yellow 138 4.96 g Pigment dispersant of Synthesis Example 4 14.16 g 1-methoxy-2-propyl acetate ... 51.68g

Example 7 A blue pigment dispersion composition was prepared in the same manner as in Example 1 except that the red pigment dispersion composition was replaced with a blue pigment dispersion composition having the following composition. Then, the same evaluation as in Example 1 was performed. C. I. Pigment Blue 15; 6 14.20 parts by weight Pigment dispersant of Synthesis Example 4 14.20 parts by weight 1-methoxy-2- Propyl acetate: 51.70 parts by weight

Comparative Example 1 In Example 1, the pigment dispersant of Synthesis Example 1 was replaced with dimethylaminoethyl acrylate-methyl methacrylate and a 2-hydroxyethyl acrylate copolymer (weight ratio: 15/85, weight average). (Molecular weight: 20,000), except that a red pigment dispersion composition was prepared in the same manner as in Example 1 and evaluated in the same manner as in Example 1.

Comparative Example 2 A red pigment dispersion composition was prepared in the same manner as in Example 1 except that the pigment dispersant of Synthesis Example 1 was replaced with the following copolymer. The same evaluation as in Example 1 was performed. A copolymer (polymer solution) was obtained in the same manner as in Synthesis Example 2 except that the following monomer solution was used in Synthesis Example 2. (Monomer solution) 2-hydroxyethyl methacrylate 4.5 parts by weight Methacrylic acid 4.5 parts by weight Benzyl methacrylate 18.0 parts by weight A methacryloyl group at one end 3.0 parts by weight Polymethyl methacrylate (number average molecular weight: 6000, macromonomer AA-6, Toa Gosei Chemical Co., Ltd.) 1-Methoxy-2-propyl acetate ... 45 parts by weight

Example 8 The following components were mixed to prepare a colored photosensitive composition for producing a color filter. Red pigment dispersion composition of Example 1 32.4 parts by weight Methacrylic acid / benzyl methacrylate polymer 9.0 parts by weight (molar ratio: 28:72, weight average molecular weight; 30,000) , 30% -1-methoxy-2-propyl acetate solution) 4- [p-N, N'-di (ethoxy ... 0.2 parts by weight carbonylmethyl) -2,6-di (tri (Chloromethyl) -S-triazine hydroquinone monomethyl ether: 0.01 part by weight 1-methoxy-2-propyl acetate: 62.0 parts by weight

The mixing was carried out for 9 hours at a peripheral speed of 9 m / s using a zirconia bead having a diameter of 0.65 mm with a motor mill M50 (manufactured by Eiger).

The viscosity of the obtained colored photosensitive composition for producing a color filter was measured in the same manner as in Example 1, a color filter was produced as described below, and the contrast was increased in the same manner as in Example 1. It was measured. The results are shown in Table 1.

That is, the colored photosensitive composition for producing a color filter was applied on a glass substrate by using a spin coater, and dried at 100 ° C. for 2 minutes to form a film having a thickness of about 2 μm. Next, after exposure with an ultrahigh pressure mercury lamp under a nitrogen stream, development was performed with a 1% aqueous sodium carbonate solution. The contrast of the obtained color filter was measured in the same manner as in Example 1.

(Embodiment 9) In Embodiment 8, Embodiment 1
Except that the red pigment dispersion composition of Example 2 was replaced with the red pigment dispersion composition of Example 2, a colored photosensitive composition was prepared in the same manner as in Example 8, and evaluated in the same manner as in Example 8. .

Example 10 The procedure of Example 8 was repeated, except that the red pigment dispersion composition of Example 1 was replaced by the red pigment dispersion composition of Example 3. A hydrophilic composition was prepared and evaluated in the same manner as in Example 8.

Example 11 The procedure of Example 8 was repeated, except that the red pigment dispersion composition of Example 1 was replaced with the red pigment dispersion composition of Example 4. A hydrophilic composition was prepared and evaluated in the same manner as in Example 8.

Example 12 The procedure of Example 8 was repeated, except that the red pigment dispersion composition of Example 1 was replaced with the green pigment dispersion composition of Example 6, and the same procedure as in Example 8 was repeated. A hydrophilic composition was prepared and evaluated in the same manner as in Example 8.

Example 13 The procedure of Example 8 was repeated, except that the red pigment dispersion composition of Example 1 was replaced with the blue pigment dispersion composition of Example 7 to obtain a colored photosensitive composition. A hydrophilic composition was prepared and evaluated in the same manner as in Example 8.

(Comparative Example 3) In Example 8, Example 1
A colored photosensitive composition was prepared in the same manner as in Example 8, except that the red pigment dispersion composition of Comparative Example 1 was replaced with the red pigment dispersion composition of Comparative Example 1, and evaluated in the same manner as in Example 8. .

(Experiment) In preparing a photosensitive material using the pigment dispersant of Example 1, prior to dispersing and mixing the acidic binder and other components, only the pigment was dispersed using the pigment dispersant. After the dispersion, the acidic binder and other components are mixed and dispersed to prepare a light-sensitive material liquid (hereinafter, this case is referred to as “pre-addition”). Were simultaneously mixed and dispersed using the pigment dispersant to prepare a photosensitive material liquid (hereinafter, this case is referred to as "post-addition"). As a result, in the case of the pre-addition, since the nitrogen atoms in the graft copolymer are adsorbed on the surface of the pigment, even if the acidic binder or the like is added later, the thickening of the photosensitive material liquid does not occur. I was not able to admit. On the other hand, in the case of the post-addition, the nitrogen atom in the graft copolymer acts with the acidic binder and the like added at the same time as the pigment dispersant, and the dispersibility of the pigment is not sufficient. Thickening of the liquid was observed,
A photosensitive material could not be produced.

[0141]

[Table 1]

From the results shown in Table 1, it is clear that the pigment dispersion composition of the present invention containing the pigment dispersant of the present invention and the colored photosensitive composition using the same have low viscosity and high contrast. It is. It is presumed that high contrast is obtained because the pigment particles are dispersed in a finely divided state. On the other hand, in the case of the pigment dispersion composition of Comparative Example and the colored photosensitive composition using the same, it is clear that the viscosity is high and the contrast is low.

[0143]

According to the present invention, the above-mentioned conventional problems can be solved. Further, according to the present invention, it is possible to provide a pigment dispersant which realizes stable and good dispersibility and fluidity of the pigment without aggregating the pigment and also has excellent light transmittance. Further, according to the present invention, it contains the pigment dispersant, is excellent in pigment dispersibility, fluidity, and the like, and has high coloring power, is excellent in alkali developability, and is widely used in paints, printing inks, color display plates, and the like. It is possible to provide a pigment dispersion composition that can be suitably used in the range. Further, according to the present invention, a color containing the pigment dispersion composition, having a high tinting strength, excellent alkali developability, forming a multicolor image on a substrate such as a color proof, and a color used in a liquid crystal color display and the like. It is possible to provide a colored photosensitive composition that can be suitably used for production of a filter and the like.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view showing a first embodiment of the pigment dispersant of the present invention.

FIG. 2 is a schematic explanatory view showing a second embodiment of the pigment dispersant of the present invention.

FIG. 3 is a schematic explanatory view showing a state in which the pigment dispersant of the first embodiment is adsorbed on the surface of pigment particles.

FIG. 4 is a schematic explanatory view showing a state where the pigment dispersant of the second embodiment is adsorbed on the surface of pigment particles.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Bond part of main chain and side chain 2 Side chain 3 Nitrogen atom 4 Pigment particle 5 Alcoholic hydroxyl group

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) C09D 125/08 C09D 125/08 4J037 133/06 133/06 4J038 151/00 151/00 G02B 5/20 101 G02B 5 / 20 101 G03F 7/027 511 G03F 7/027 511 (72) Inventor Shinichiro Morimoto 200, Onakazato, Fujinomiya-shi, Shizuoka Fuji Photo F-Term (in reference) 2H025 AA00 AB09 AB13 AC01 AD01 BC42 CA01 CA14 CA28 CB42 CC20 FA03 FA17 2H048 BA45 BA47 BA48 4J002 BN111 BN121 FD096 GH01 HA06 4J011 QA03 QA04 QA06 QA08 QB01 SA21 SA31 SA74 SA78 UA01 UA06 WA01 WA02 4J027 AA02 AA07 AA08 AC03 AC04 AG01 AH03 BA08 BA08 BA08 BA05 BA08 4J037 AA30 CC13 CC16 CC18 CC29 DD04 DD19 DD23 DD24 EE12 EE28 EE43 FF02 FF09 FF15 FF23 4J038 CC021 CC022 CG031 CG032 CG081 CG082 CG141 CG142 CH031 CH032 CJ131 CJ132 FA091 FA092 FA111 FA112 FA1112 08 PB09

Claims (11)

[Claims] 1. A pigment dispersant comprising a graft copolymer having a nitrogen atom and an alcoholic hydroxyl group. 2. The graft copolymer has a polymerizable oligomer having an ethylenically unsaturated double bond at a terminal, a nitrogen-containing monomer having a nitrogen atom and an ethylenically unsaturated double bond, and an alcoholic hydroxyl group. The pigment dispersant according to claim 1, wherein the pigment dispersant contains a polymerizable monomer as a copolymer unit. 3. The graft copolymer contains, as copolymer units, 20 to 98% by weight of a polymerizable oligomer, 1 to 40% by weight of a nitrogen-containing monomer, and 1 to 40% by weight of a polymerizable monomer. The pigment dispersant according to claim 2. 4. The polymerizable oligomer is an alkyl (meth)
At least one oligomer selected from a polymer of acrylate and a copolymer of alkyl (meth) acrylate and polystyrene, having a number average molecular weight of 10
4. The pigment dispersant according to claim 2, wherein the pigment dispersant is from 00 to 10,000 and has a (meth) acryloyl group at a terminal. 5. A polymerizable oligomer having an alcoholic hydroxyl group and having an ethylenically unsaturated double bond at a terminal, and a nitrogen-containing monomer having a nitrogen atom and an ethylenically unsaturated double bond, wherein the graft copolymer has an alcoholic hydroxyl group. The pigment dispersant according to claim 1, wherein the pigment dispersant comprises: 6. The pigment dispersant according to claim 5, wherein the graft copolymer contains 20 to 99% by weight of a polymerizable oligomer and 1 to 80% by weight of a nitrogen-containing monomer as a copolymer unit. . 7. The polymerizable oligomer is an alkyl (meth)
At least one alcoholic hydroxyl group-containing oligomer selected from an acrylate polymer and a copolymer of an alkyl (meth) acrylate and polystyrene, having a number average molecular weight of 1,000 to 10,000, 7. The pigment dispersant according to claim 5, which has an acryloyl group. 8. The nitrogen-containing monomer represented by the following general formula (1)
Is at least one selected from compounds represented by
The pigment dispersant according to any one of claims 2 to 7. General formula (1)In the general formula (1), R¹¹Is a hydrogen atom or methyl
Represents a hydroxyl group. R¹²Represents an alkylene group having 1 to 8 carbon atoms.
You. X¹Is -N (R¹³) (R¹⁴), (R¹³And R
¹⁴Is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or phenyl.
Represents a group represented by ¹⁵N (R¹⁶) (R¹⁷) (R¹⁵Is charcoal
Represents an alkylene group having a prime number of 1 to 6,¹⁶And R¹⁷Is the water
Represents an atom, an alkyl group having 1 to 6 carbon atoms or a phenyl group.
), Pyrrolidino, pyrrolidyl, pyridyl, pipette
Represents a lysino group or a morpholino group. m and n are 1 or
Represents 0. 9. The pigment dispersant according to claim 1, wherein the graft copolymer further contains an acidic monomer as a copolymer unit. 10. A pigment dispersion composition comprising the pigment dispersant according to claim 1 and a pigment dispersed in an organic solvent. 11. The pigment dispersion composition according to claim 10, a binder polymer having an acidic group, a polyfunctional monomer having two or more ethylenically unsaturated double bonds, and a photopolymerization initiator. A colored photosensitive composition comprising: