JP5408476B2 - Pigment dispersant and pigment dispersion - Google Patents

Description

  The present invention relates to a pigment dispersant and a pigment dispersion particularly suitable for a color filter.

  Conventionally, color filters (hereinafter referred to as “CF”) used for manufacturing liquid crystal color displays and imaging devices are mainly manufactured by a method called a pigment dispersion method using a pigment having excellent light resistance and heat resistance as a colorant. It has become. However, in general, a color filter in which a pigment is dispersed has a problem that the degree of polarization controlled by the liquid crystal is disturbed due to light scattering by the pigment. That is, since light leaks when light must be blocked (OFF state) or transmitted light attenuates when light must be transmitted (ON state), display devices in the ON state and the OFF state There is a problem that the upper luminance ratio (contrast ratio) is low.

  For this reason, it has become necessary to improve the transparency of the colored pixels, increase the contrast of the transmitted light of the colored pixels, and increase the pigment concentration of the colored pixels. However, the CF coating solution obtained by dispersing ordinary pigments improves the transparency of colored pixels by improving the dispersibility of pigments, and prevents the increase in viscosity and decrease in storage stability due to an increase in pigment concentration. It is difficult to do so, and these improvements are desired.

In order to achieve high brightness and high contrast of the color filter, it has been studied to refine the pigment contained in the colored layer and to optimize the pigment and the pigment dispersant. For example, in a pigment composed of an aggregate of primary particles, the number ratio of primary particles having a particle size of 0.1 μm or less is 95% or more of all particles, and the number ratio of primary particles having a particle size of more than 0.1 μm is 5% of the total number of particles. A micronized pigment characterized in that it is less than% is disclosed. (For example, see Patent Document 1)
However, the pigment particle size disclosed herein is the particle size of the produced pigment itself. Pigments whose primary particles have been made finer generally tend to aggregate, and even if finer pigments are used, the pigment particles actually dispersed in the resin composition may exist as coarse particles or fine particles. In general, it is difficult to obtain a stable coloring composition, for example, when the conversion to too much proceeds, a huge lump of pigment solid is formed. As a result, the viscosity of the vehicle in which the pigment is dispersed may be increased, or the coloring power of the ink or paint using the vehicle in which the pigment is dispersed may be decreased, or the gloss of the coating film may be decreased.

On the other hand, as an example of optimizing the pigment dispersant, it is produced by an addition reaction between a polymer having a repeating unit having a primary or secondary amino group and a polymer having an ethylenically unsaturated double bond at one end. An example is known in which a pigment dispersion composition in which a graft polymer and an organic pigment are dispersed in an organic solvent is used as a colored photosensitive composition for a color filter (see, for example, Patent Document 1).
However, the design of the graft side chain and amino group is important to control the dispersion stability for the dispersion medium that controls the performance as a pigment dispersant and the adsorption to the pigment, but the graft side chain using a macromonomer alone is a base. It is difficult to balance the properties, and depending on the pigment type, the dispersibility may be inferior because the affinity for the pigment is too strong.

  On the other hand, as a main pigment used in the production of CF, a green pigment is phthalocyanine green, for example, C.I. I. Pigment Green (hereinafter referred to as PG) 36, PG7, etc .; the red pigment is a diketopyrrolopyrrole (hereinafter referred to as DPP) red, such as C.I. I. Pigment Red (hereinafter referred to as PR) 254, anthraquinone red, such as PR177, azo red, such as PR242; blue pigment is phthalocyanine blue, such as C.I. I. Pigment Blue (hereinafter referred to as PB) 15: 6 is generally used. There is a difference between the hue of these pigments and the color characteristics required for the liquid crystal display, and yellow pigments such as C.I. I. Pigment Yellow (hereinafter referred to as PY) 138, PY139, PY150 and the like are used in small amounts as complementary colors, and blue pigments include purple pigments such as C.I. I. A small amount of pigment violet (hereinafter referred to as PV) 23 is used as a complementary color.

In the case of a pigment dispersant for a complementary color pigment, it is necessary not to affect the dispersibility of the main pigment. In particular, the ability to disperse both the main pigment and the complementary color pigment with one dispersant reduces the performance when adjusting chromaticity. This is also advantageous in that it can be prevented.

JP 2003-89756 A Japanese Patent Laid-Open No. 2002-226487

  The object of the present invention is to realize stable and good dispersibility and storage stability of the pigment without agglomerating the pigment, high coloring power, paint, printing ink, color display board, color proof, etc. It is an object of the present invention to provide a pigment dispersant that can be suitably used for the formation of multicolor images, the production of color filters used in liquid crystal color displays and the like.

  The present inventors have found that the performance of the pigment dispersant requires an anchor site that adsorbs to the pigment, a site that is compatible with the solvent, and a structure for preventing aggregation. And, as a site having an affinity for the solvent, a polymer having a low molecular weight component or a solvent affinity component introduced therein and a polymer having a high molecular weight component introduced as a structure for preventing aggregation is found to solve the above problems. Solved.

That is, the present invention is selected from the group consisting of the vinyl copolymer (A) having a functional group that reacts with an amino group at one end of the amino group of polyallylamine and the following (B) to (E). Provided is a pigment dispersant mainly composed of a modified polyallylamine obtained by reacting with one or more compounds.
(1) A vinyl copolymer having a functional group that reacts with an amino group at one end, wherein the amount of the functional group that reacts with an amino group, the copolymer composition or the copolymer composition ratio is the vinyl copolymer (A Vinyl copolymer (B) different from
(2) (Meth) acrylate (C) having a polyalkylene glycol chain.
(3) A polyester having a functional group that reacts with an amino group at one end, a polyamide that has a functional group that reacts with an amino group at one end, or a polyester amide (D) that has a functional group that reacts with an amino group at one end.
(4) Monocarboxylic acid or (meth) acrylate (E).

  The present invention also provides a pigment dispersion using the pigment dispersant.

  According to the present invention, stable and good dispersibility and storage stability of the pigment can be realized without agglomerating the pigment, the coloring power is high, and there are many colors on the substrate such as paint, printing ink, color display board, color proof, etc. It is possible to provide a pigment dispersant that can be suitably used for image formation, production of color filters used for liquid crystal color displays, and the like.

  The pigment dispersant of the present invention contains a modified polyallylamine as a main component. Specifically, a vinyl copolymer (A) having a functional group that reacts with an amino group at one end on the amino group of polyallylamine (hereinafter referred to as a vinyl copolymer having a functional group that reacts with an amino group at one end) (A) is referred to as “vinyl copolymer (A)”) and a modified polyallylamine obtained by reacting one or more compounds selected from the group consisting of (B) to (E) below: Is the main component.

  (1) A vinyl copolymer having a functional group that reacts with an amino group at one end, wherein the amount of the functional group that reacts with an amino group, the copolymer composition or the copolymer composition ratio is the vinyl copolymer (A Vinyl copolymer (B) different from

  As the vinyl copolymer (B), a vinyl copolymer (B1) is preferable. The vinyl copolymer (B1) comprises a weight% of a functional group that reacts with an amino group at one end of the vinyl copolymer (A), and an amino group at one end of the vinyl copolymer (B1). The ratio by weight% of the functional group to be reacted is in the range of 0.4 to 0.8, and the molar ratio (A) / (B1) with the vinyl copolymer (A) is (A) / ( It is preferable to react with the modified polyallylamine so that B1) = 0.25 to 4.0. (Hereinafter referred to as vinyl copolymer (B1))

  Moreover, as said vinyl copolymer (B), a vinyl copolymer (B2) is preferable. The vinyl copolymer (B2) is a vinyl copolymer obtained by polymerizing a plurality of vinyl monomers, and the difference between the Tg of the vinyl copolymer (A) and the Tg of the vinyl copolymer (B2) is 20 ° C. The molar ratio (A) / (B2) between the vinyl copolymer (A) and the vinyl copolymer (B2) is (A) / (B2) = 0.25 to 4.0. It is preferable to react with the modified polyallylamine. (Hereinafter referred to as vinyl copolymer (B2))

  (2) (Meth) acrylate (C) having a polyalkylene glycol chain. (Hereinafter referred to as (meth) acrylate (C)). In particular, the polyalkylene glycol chain is preferably reacted with the modified polyallylamine so as to have a ratio of 1 to 30% by weight with respect to the whole molecule.

  (3) Polyester having a functional group that reacts with an amino group at one end, Polyamide having a functional group that reacts with an amino group at one end, or Polyesteramide having a functional group that reacts with an amino group at one end (D) (Referred to as polymer (D)). Among them, it is preferable that the modified polyallylamine is reacted with the modified polyallylamine so that these residues have a ratio of 1 to 50% by weight with respect to the whole molecule.

  (4) Monocarboxylic acid or (meth) acrylate (E). Among these, it is preferable to react with the modified polyallylamine so that these residues have a ratio of 1 to 30% by weight with respect to the whole molecule.

That is, a vinyl copolymer (A) having a functional group that reacts with an amino group at one end on the amino group of polyallylamine, and a functional group that reacts with an amino group at one end, and the vinyl copolymer A pigment dispersant mainly comprising a modified polyallylamine obtained by reacting a vinyl copolymer (B1) different from (A),
The ratio of the weight% of the functional group that reacts with the amino group at one end of the vinyl copolymer (A) and the weight% of the functional group that reacts with the amino group at one end of the vinyl copolymer (B1). Is in the range of 0.4 to 0.8, and the molar ratio (A) / (B1) between the vinyl copolymer (A) and the vinyl copolymer (B1) is (A) / ( A pigment dispersant where B1) = 0.25 to 4.0 is preferred.

Further, a vinyl copolymer (A) having a functional group that reacts with an amino group at one end in an amino group of polyallylamine, and a functional group that reacts with an amino group at one end, and the vinyl copolymer A pigment dispersant mainly comprising a modified polyallylamine obtained by reacting a vinyl copolymer (B2) different from (A),
The vinyl copolymer (B2) is a vinyl copolymer obtained by polymerizing a plurality of vinyl monomers, and the difference between the Tg of the vinyl copolymer (A) and the Tg of the vinyl copolymer (B2) is The molar ratio (A) / (B2) between the vinyl copolymer (A) and the vinyl copolymer (B2) is (A) / (B2) = 0.25-4. A pigment dispersant of 0.0 is preferred.

In addition, a modified polyallylamine obtained by reacting the amino group of polyallylamine with a vinyl copolymer (A) having a functional group that reacts with an amino group at one end and a compound having a functional group that reacts with an amino group A pigment dispersant having a main component,
A pigment dispersant in which the compound is a (meth) acrylate (C) having a polyalkylene glycol chain, and the modified polyallylamine has the polyalkylene glycol chain in a proportion of 1 to 30% by weight with respect to the whole molecule. .

In addition, a modified polyallylamine obtained by reacting the amino group of polyallylamine with a vinyl copolymer (A) having a functional group that reacts with an amino group at one end and a compound having a functional group that reacts with an amino group A pigment dispersant having a main component,
Polyester having a functional group that reacts with an amino group at one end, a polyamide that has a functional group that reacts with an amino group at one end, or a polyesteramide (D) that has a functional group that reacts with an amino group at one end Yes,
The modified polyallylamine is preferably a pigment dispersant having these residues in a proportion of 1 to 50% by weight based on the whole molecule.

In addition, a modified polyallylamine obtained by reacting the amino group of polyallylamine with a vinyl copolymer (A) having a functional group that reacts with an amino group at one end and a compound having a functional group that reacts with an amino group A pigment dispersant having a main component,
The compound is a monocarboxylic acid or (meth) acrylate (E),
The modified polyallylamine is preferably a pigment dispersant having these residues in a proportion of 1 to 30% by weight based on the whole molecule.

(Polyallylamine)
The polyallylamine used in the present invention may be obtained by polymerizing allylamine in the presence of a polymerization initiator, optionally in the presence of a chain transfer catalyst, by a known method, or a commercially available product may be used. As a commercial item, it sells as polyallylamine series, such as PAA-01, PAA-03, PAA-05, PAA-15, PAA-10C, from Nitto Boseki Co., Ltd., for example.

  The number average molecular weight of the polyallylamine is preferably 150 to 100,000, more preferably 600 to 20,000. If the number average molecular weight of the polyallylamine used in the present invention is less than 150, there is a risk that the pigment will be difficult to disperse due to insufficient adsorptive power to the pigment. In addition to the increase in viscosity and gelation, the molecular weight of the entire pigment dispersant becomes too large, and the dispersibility may be lowered due to aggregation of pigments.

(Pigment dispersant vinyl polymer (A))
In the vinyl polymer (A) used in the present invention, examples of the functional group that reacts with an amino group to form an amide bond include a haloformyl group such as a carboxyl group and a chloroformyl group, and an oxycarbonyl group such as a methoxycarbonyl group. . Among these, a carboxyl group is preferable because it can be easily introduced into a vinyl copolymer.
In order to obtain a vinyl copolymer having a carboxyl group at one end, for example, a method of coexisting with a chain transfer agent having a carboxyl group at the time of polymerization can be mentioned. Examples of the chain transfer agent having a carboxyl group include thiocarboxylic acids such as mercaptoacetic acid, 2-mercaptopropionic acid, and 3-mercaptopropionic acid. It can also be obtained by a method of synthesizing a polymerizable monomer by a living radical polymerization method using a polymerization initiator having a carboxyl group such as 4,4′-azobis-4-cyanopentanoic acid.

Examples of the polymerizable monomer that is a raw material for the vinyl polymer (A) include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate. Homopolymer of (meth) acrylic acid alkyl ester, or these esters or these esters, and alkenylbenzene such as styrene, α-methylstyrene, vinyltoluene, vinyl acetate, vinylpyridine, acrylamide, methacrylamide, Examples thereof include copolymers with dimethylaminoethyl methacrylate, N-methylolacrylamide, N-butoxymethylacrylamide, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, and the like. Among these, one kind or two or more kinds can be used.
However, it is preferable not to use a polymerizable monomer that has a functional group that reacts with an amino group to form an amide bond, for example, a functional group that is equivalent to or more highly reactive with an amino group than a carboxyl group. The vinyl polymer containing the polymerizable monomer as a raw material is not only the terminal of the vinyl copolymer but also the functional group is randomly grafted to the main chain of the copolymer, so that it reacts with polyallylamine. There is a possibility of gelling inside, and the performance of the resulting pigment dispersant may be deteriorated. Specifically, since a polymerizable monomer such as butadiene, isoprene, chloroprene, (meth) acrylic acid, itaconic acid, maleic anhydride has a group highly reactive with an amino group, a vinyl polymer is used. It is preferable not to use it as a raw material for (A).

  The vinyl polymer (A) can be obtained by heating the above various polymerizable monomers in a reaction vessel in the presence of a polymerization initiator and aging as necessary. The reaction conditions vary depending on, for example, the polymerization initiator and the solvent, but the reaction temperature is 30 to 150 ° C, preferably 60 to 120 ° C. The polymerization can be carried out in the presence of a non-reactive solvent.

  Examples of the polymerization initiator include peroxides such as t-butyl peroxybenzoate, di-t-butyl peroxide, cumene perhydroxide, acetyl peroxide, benzoyl peroxide, lauroyl peroxide; azobisisobutylnitrile, Examples thereof include azo compounds such as azobis-2,4-dimethylvaleronitrile and azobiscyclohexanecarbonitrile.

  Non-reactive solvents include, for example, aliphatic hydrocarbon solvents such as hexane and mineral spirits; aromatic hydrocarbon solvents such as benzene, toluene and xylene; ester solvents such as butyl acetate; methanol and butanol And alcohol solvents such as: aprotic polar solvents such as dimethylformamide, dimethyl sulfoxide, N-methylpyrrolidone, and pyridine. These solvents may be used in combination. As these solvents, those capable of dissolving the resulting vinyl polymer (A) can be appropriately selected and used.

  The molecular weight of the vinyl polymer (A) used in the present invention is preferably in the range of number average molecular weight of 500 to 100,000, and more preferably in the range of 1,000 to 20,000. If the number average molecular weight is less than 500, sufficient steric repulsion effect as a pigment dispersant may not be maintained, and if it exceeds 100,000, the viscosity of the vinyl polymer is increased and the solvent solubility is decreased. Dispersant performance may be reduced.

(Reaction between polyallylamine and vinyl polymer (A))
The reaction between the polyallylamine and the vinyl polymer (A)) can be performed, for example, at 200 ° C. or lower under a nitrogen gas stream. For the reaction, a known polymerization catalyst such as tin-based or titanium-based may be used. If necessary, a non-reactive solvent such as toluene, xylene, or solvesso that does not participate in the reaction can be used. The solvent used is not necessarily removed and can be used as it is as one component of the pigment dispersant.

  The graft ratio of the vinyl polymer (A) to the polyallylamine is preferably in the range of about 20 to 80%, and in the range of 30 to 70%, from the group consisting of the above (B) to (E). It is particularly preferable because it is excellent in the balance between the affinity for the one or more selected compounds and polyallylamine, the affinity for the diluent solvent or the film-forming resin, and the pigment. Here, the graft ratio represents the reaction amount of the carboxyl group of the vinyl polymer (A) with respect to the total amount of amino groups of the polyallylamine, and the vinyl having an amide bond, which the modified polyallylamine of the present invention has. The polymer (A) residual chain (here, the vinyl polymer (A) residual chain means the remaining part of the reaction of the carboxyl group). Specifically, the value is calculated from Equation (1), and can be obtained by setting AM1 and AM2 so that the AM value is 0.2 to 0.80.

In the formula, AM1 represents an amine value (KOHmg / g) relative to the total weight of the vinyl copolymer having a functional group that reacts with polyallylamine and an amino group to form an amide bond at one end, and AM2 represents a modified polyallylamine. Represents the amine value.
The amine value AM1 can be calculated by dividing the amine value of polyallylamine used as a raw material by the total weight of the vinyl polymer (A) and polyallylamine used in the reaction. The amine value AM2 can be obtained by actually measuring the amine value after the reaction.

  When the residual chain of the vinyl polymer (A) contained in the modified polyallylamine is less than 20%, the pigments tend to aggregate with each other, and the insufficient viscosity reduction effect and the ink film may be affected. Further, when the residual chain of the vinyl polymer (A) of the modified polyallylamine exceeds 80%, one or more compounds selected from the group consisting of (B) to (E) and polyallylamine, Insufficient reactive sites and amino groups, which are functional groups that adsorb to pigments, tend to lower the dispersion stability of some pigments, resulting in insufficient viscosity reduction effects and problems with ink films. There is.

(1) Vinyl copolymer (B))
The vinyl copolymer (B) used in the present invention is a copolymer having a functional group that reacts with an amino group at one end and different from the vinyl copolymer (A). Specifically, “different from the vinyl copolymer (A)” means that the composition of the polymerizable monomer used as a raw material is different, or the content of the functional group that reacts with an amino group to form an amide bond. The thing which is different or the content of the chain transfer agent to be used is different.

In the vinyl copolymer (B), examples of the functional group that reacts with an amino group to form an amide bond include a haloformyl group such as a carboxyl group and a chloroformyl group, and an oxycarbonyl group such as a methoxycarbonyl group. Among these, a carboxyl group is preferable because it can be easily introduced into a vinyl copolymer.
In order to obtain a vinyl copolymer having a carboxyl group at one end, for example, a method of coexisting a chain transfer agent having a carboxyl group at the time of polymerization can be mentioned. Examples of the chain transfer agent having a carboxyl group include thiocarboxylic acids such as mercaptoacetic acid, 2-mercaptopropionic acid, and 3-mercaptopropionic acid. It can also be obtained by a method of synthesizing a polymerizable monomer by a living radical polymerization method using a polymerization initiator having a carboxyl group such as 4,4′-azobis-4-cyanopentanoic acid.

For the polymerizable monomer that is a raw material of the vinyl copolymer (B) and the method for producing the vinyl copolymer (B), refer to the raw material and the production method described in the above-mentioned vinyl copolymer (A). be able to. Each selection is preferably made so as to satisfy (B1) or (B2) given as an example of the preferred vinyl copolymer (B) described above.
The vinyl copolymer (B) to be introduced may be single or plural, but the vinyl polymer (B) residual chain (the vinyl polymer (B) residual chain here is a carboxyl group having When the combined value of the remaining chain of the vinyl polymer (A) exceeds 95%, the amino group, which is a functional group that adsorbs to the pigment, is insufficient, and depending on the pigment, the dispersion stability decreases. Therefore, it is not preferable.

(Vinyl copolymer (B1))
The vinyl copolymer (B1) has a functional group that reacts with an amino group at one end and is a copolymer different from the vinyl copolymer (A), and the vinyl copolymer (A) The ratio of the weight percent of the functional group that reacts with the amino group at one end to the weight percent of the functional group that reacts with the amino group at one end of the vinyl copolymer (B1) is 0.4 to 0.8. And the modified polyallylamine so that the molar ratio (A) / (B1) to the vinyl copolymer (A) is (A) / (B1) = 0.25 to 4.0 It is preferable to have reacted with.
Specifically, the vinyl copolymer (B1) is a vinyl copolymer having a carboxyl group, and a copolymer having a molecular weight different from that of the vinyl copolymer (A). The molecular weight is adjusted by the content of the carboxyl group at one end of the vinyl copolymer. The weight percentage of the carboxyl group in the vinyl copolymer is preferably in the range of 1 to 10, and the vinyl copolymer ( The ratio of the weight percent of the carboxyl group at one end of A) to the weight percent of the carboxyl group at one end of the vinyl copolymer (B1) is preferably in the range of 0.4 to 0.8. . (However, the vinyl copolymer (B1) at this time is assumed to have a higher molecular weight than the vinyl copolymer (A).)
Further, the ratio of the vinyl polymer (B1) residual chain (here, the vinyl polymer (B1) residual chain means the remaining part of the reaction of the carboxyl group) and the vinyl polymer (A) residual chain is the ratio of the vinyl copolymer. It is preferable that molar ratio (A) / (B1) with a polymer (A) is (A) / (B1) = 0.25-4.0.

(Vinyl copolymer (B2))
The vinyl copolymer (B2) is obtained by polymerizing a plurality of vinyl monomers, and the vinyl copolymer (A) has a difference in Tg between the vinyl copolymer (A) and the vinyl copolymer (B2) of 20 ° C. or more. It is a polymer. Here, Tg is defined as a value measured by DSC (differential scanning calorimetry) or tan δ peak of dynamic viscoelasticity.
As described above, the molar ratio (A) / (B2) between the vinyl copolymer (A) and the vinyl copolymer (B2) is (A) / (B2) = 0.25 to 4.0. As it is, it is preferable to react with the modified polyallylamine.
Specifically, the Tg of the vinyl copolymer (B2) is preferably 100 ° C. to −50 ° C., and the Tg is 60 ° C. to −50 ° C., although it varies depending on the Tg of the vinyl copolymer (A). It is particularly preferred.

((2) (Meth) acrylate (C))
In the (meth) acrylate (C) used in the present invention, having a polyalkylene glycol chain means a state of polyalkylene glycol (meth) acrylate. Specific examples of the polyalkylene glycol include polyethylene glycol, polypropylene glycol, polybutylene glycol, and mixtures thereof. Among them, polyethylene glycol and polypropylene glycol are preferable.
The (meth) acrylate (C) is preferably reacted with the modified polyallylamine so as to have the polyalkylene glycol chain in a proportion of 1 to 30% by weight based on the whole molecule.

((3) Polymer (D))
Specifically, the polymer (D) used in the present invention is any one of the following (3-1) to (3-3).
(3-1) Polyester having a functional group that reacts with an amino group at one end;
(3-2) Polyamide having a functional group that reacts with an amino group at one end (3-3) Polyester amide that has a functional group that reacts with an amino group at one end

(3-1) The polyester having a functional group that reacts with an amino group at one end is specifically a polyester having a carboxyl group at the end. This can be synthesized by various methods as follows.
(A) Addition reaction for adding a lactone compound to a monocarboxylic acid compound, (b) Addition reaction for adding a lactone compound to a hydroxycarboxylic acid compound, (c) Three components: a monocarboxylic acid compound, a hydroxycarboxylic acid compound, and a lactone compound And the like.

  (3-2) The polyamide having a functional group that reacts with an amino group at one end is specifically a polyamide having a carboxyl group at the end. This is prepared from lactams such as ε-caprolactam and ω-laurolactam, and aminocarboxylic acids such as aminocaproic acid and 11-aminoundecanoic acid.

  (3-3) The polyesteramide having a functional group that reacts with an amino group at one end is specifically a co-condensate of an ester and an amide having a carboxyl group at the end. This can be prepared by co-condensing hydroxycarboxylic acid, lactone and the like used in the production of the polyester and polyamide with aminocarboxylic acid and lactam.

  The polymer (D) is preferably reacted with the modified polyallylamine so that these residues have a ratio of 1 to 50% by weight with respect to the whole molecule. Here, the residue represents the remaining polymer portion reacted with the carboxyl group.

((4) Monocarboxylic acid or (meth) acrylate (E))
The monocarboxylic acid used in the present invention is not particularly limited as long as it is a compound having one carboxylic acid group in one molecule, and specifically, acetic acid, propionic acid, caprylic acid, nonanoic acid, capric acid, octylic acid. And aliphatic monocarboxylic acids such as lauric acid, myristic acid, palmitic acid, stearic acid, isononanoic acid, and arachidic acid, and aromatic monocarboxylic acids such as benzoic acid and p-butylbenzoic acid.

The (meth) acrylate used in the present invention is, for example, (meth) acrylic such as methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, etc. Homopolymers of acid alkyl esters, or between these esters or these esters with alkenylbenzene such as styrene, α-methylstyrene, vinyltoluene, and vinyl acetate, vinylpyridine, acrylamide, methacrylamide, dimethylamino methacrylate Examples thereof include copolymers with ethyl, N-methylolacrylamide, N-butoxymethylacrylamide, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, and the like.
The monocarboxylic acid and the (meth) acrylate are preferably reacted with the modified polyallylamine so as to have these residues in a proportion of 1 to 30% by weight based on the whole molecule. Here, the residue represents the remaining monocarboxylic acid or (meth) acrylate reacted with the carboxyl group.

(Reaction of polyallylamine with one or more compounds selected from the group consisting of (B) to (E))
The reaction between polyallylamine and one or more compounds selected from the group consisting of (B) to (E) can be carried out, for example, at 200 ° C. or lower under a nitrogen gas stream. For the reaction, a known polymerization catalyst such as tin-based or titanium-based may be used. If necessary, a non-reactive solvent such as toluene, xylene, or solvesso that does not participate in the reaction can be used. The solvent used is not necessarily removed and can be used as it is as one component of the pigment dispersant.
The reaction of polyallylamine and one or more compounds selected from the group consisting of (B) to (E) may be performed simultaneously with the vinyl copolymer (A) or sequentially.

  In the pigment dispersant of the present application, the vinyl copolymer (A) assumes a high molecular weight component or a solvent affinity component, and the vinyl copolymer (B1) assumes a low molecular weight component or a solvent affinity component, The vinyl copolymer (B2) assumes a low molecular weight component, the (meth) acrylate (C) assumes a low molecular weight component or a solvent affinity component, and the polymer (D) has a low molecular weight component or a solvent affinity component. Assuming that the monocarboxylic acid or (meth) acrylate (E) is a low molecular weight component. By combining these, it is possible to obtain a pigment dispersant in which a low molecular weight component or a solvent affinity component is introduced as a site having affinity for the solvent, and a high molecular weight component is introduced as a structure for preventing aggregation. .

(Pigment dispersant and other ingredients)
The pigment dispersant of the present invention may contain a non-reactive solvent used in the production of the modified polyallylamine, and after the non-reactive solvent used in the production is distilled off, another solvent is newly added. It doesn't matter.
The pigment dispersant of the present invention may contain some components other than the modified polyallylamine as long as the effects of the present invention are not impaired. In the present invention, the “main component” indicates that the modified polyallylamine used in the present invention may be contained within a range in which the effects of the present invention can be obtained. Specifically, if the content of the modified polyallylamine as a solid component is 90% or more, the affinity between the modified polyallylamine, the pigment and the solvent is strong. The effects of the invention can be fully exerted. Examples of other components include by-products generated during the production of the modified polyallylamine, or non-reactive thermoplastic resins.

(Pigment composition)
The pigment composition of the present invention contains the pigment dispersant and a pigment. The pigment dispersant of the present invention is usually used in an amount of 1 to 200% by weight in terms of pigment dispersant (modified polyallylamine) based on the pigment.
As the pigment contained in the pigment composition, all organic pigments, inorganic pigments and carbon black which can be generally used for ink or paint can be used. The organic pigment is not particularly limited. Examples include perylene pigments, diketopyrrolopyrrole pigments, perinone pigments, quinophthalone pigments, anthraquinone pigments, thioindigo pigments, benzimidazolone pigments, and azo pigments. Examples of inorganic pigments include titanium dioxide, iron oxide, cadmium sulfide, calcium carbonate, barium carbonate, barium sulfate, clay, talc, and chrome lead. Examples of carbon black include acetylene black, channel black, and furnace black.

The pigment dispersant of the present invention is particularly suitable as a pigment dispersant for a pigment dispersion composition for a color filter.
Specifically, the pigment dispersion composition for a color filter is obtained by dispersing a pigment dispersant and a pigment in an organic solvent.

(Pigment dispersant)
The pigment dispersant of the present invention may contain only the modified polyallylamine, or may further contain other components appropriately selected as necessary. Examples of the other components include known dispersants. Specifically, nonanoamide, decanamide, dodecanamide, N-dodecylhexadecanamide, N-octadecylpropioamide, N, N-dimethyldodecanamide 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 (hydroxyethyl) Amines having a hydroxy group, such as rupolyoxyethylene) -1,2-diaminoethane, 1,4-bis (2-hydroxyethyl) piperazine and 1- (2-hydroxyethyl) piperazishi, other pecotamide, isonipecotamide, nicotine And compounds such as acid amides. These may be commercially available products or may be appropriately synthesized. Examples of the commercially available products include Shigenox-105 (trade name, manufactured by Hackol Chemical Co., Ltd.).

  The content of the other components in the pigment dispersant is preferably 1% by weight to 90% by weight, and more preferably 1% by weight to 70% by weight. When the content is from 1% by weight to 90% by weight, the performance as a pigment dispersant is sufficiently exhibited, and an increase in the viscosity of the pigment dispersion composition can be suppressed.

  Further, the pigment dispersant of the present invention may contain various surfactants, and the inclusion of the surfactant is effective for improving the dispersion stability. Examples of the surfactant include anionic surfactants typified by alkyl naphthalene sulfonates and phosphate ester salts, cationic surfactants typified by amine salts, aminocarboxylic acids, and betaine types. And amphoteric surfactants.

  Dispersion by the pigment dispersant of the present invention means that the pigment particles that are generally present in the state of secondary particles are loosened into primary particles to prevent reaggregation. The pigment dispersant of the present invention is a graft type dispersant having an adsorption site to the pigment and a steric repulsion site that prevents reaggregation after the pigment is dispersed in the form of primary particles. However, it exhibits a sufficiently good dispersion effect. Further, the dispersion of the pigment by the pigment dispersant of the present invention is effectively achieved by direct mixing of the pigment dispersant and the pigment, and is preferably performed in a state where particles that can be dispersed other than the pigment are present as much 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 fluidized. Is effectively suppressed. On the other hand, when the pigment is dispersed in the presence of particles that can be dispersed in addition to the pigment particles, the pigment dispersant of the present invention is not adsorbed on the surface of the target pigment particles, but is adsorbed on the surface of other particles, The pigment dispersion effect of the pigment dispersant may be impaired. Therefore, for example, when producing a photosensitive material or the like, the pigment and the pigment dispersant of the present invention are mixed at an early stage to contain the pigment in the photosensitive material or the like in a well dispersed state. It is preferable that the pigment dispersant of the present invention be added and mixed at a later time such as when the photosensitive layer coating solution is prepared.

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

(Organic 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, and a black pigment.

  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. I. Pigment yellow 86, C.I. I. Pigment yellow 93, C.I. I. Pigment yellow 109, C.I. I. Pigment yellow 110, C.I. I. Pigment yellow 117, C.I. I. Pigment yellow 125, C.I. I. Pigment yellow 137, C.I. I. Pigment yellow 138, C.I. I. Pigment yellow 139, 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 154, C.I. I. Pigment yellow 166, C.I. I. Pigment yellow 168, C.I. I. Pigment yellow 185, and the like.

  Examples of orange pigments 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. 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 215, C.I. I. Pigment red 216, C.I. I. Pigment red 217, C.I. I. Pigment red 220, C.I. I. Pigment Red 223, C.I. I. Pigment red 224, C.I. I. Pigment red 226, C.I. 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 272, C.I. I. Pigment red 270, C.I. I. Pigment red 255, C.I. I. Pigment red 264, C.I. I. Pigment red 254, and the like.

  Examples of the violet pigment include C.I. 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. Pigment Violet 40, C.I. I. Pigment violet 50, and the like.

  Examples of the blue pigment include C.I. I. Pigment blue 15, C.I. I. Pigment blue 15: 6, C.I. I. Pigment blue 22, C, I.I. 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 36, 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 26, 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. Pigment Yellow 138, Pigment Yellow 139, Pigment Yellow 185, Pigment Red 254 Pigment Green 36, Pigment Blue 15 and the like are particularly preferable.

(Organic solvent)
The organic solvent used for dispersion 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 mono (Poly) alkylene glycol monoalkyl ethers such as ethyl ether, diethylene glycol monomethyl ether, ethylene glycol monoethyl ether and their acetates, for example, 1-methoxy-2-propyl acetate, 1-ethoxy-2-propyl acetate and the like; Acetic acid esters 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; methyl ethyl Tons, 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 individually by 1 type and may use 2 or more types together. Among these, alkylene glycol monoalkyl ethers and their acetates, acetates, methyl ethyl ketone, and the like are preferable.

  The content of the pigment in the pigment dispersion is usually 5% to 80% by weight, and preferably 10% to 70% by weight. When the content is 5% by weight to 80% by weight, sufficient coloring power can be obtained without increasing the viscosity of the pigment dispersion.

  The content of the pigment dispersant in the pigment dispersion is usually 0.1 parts by weight to 200 parts by weight and preferably 1 part by weight to 50 parts by weight with respect to 100 parts by weight of the pigment. When the content is from 0.1 part by weight to 200, the viscosity of the pigment dispersion does not increase, and the thickness of the coating film for obtaining chromaticity in the production of a color filter or the like. Can be adjusted easily.

  The content of the organic solvent in the pigment dispersion is usually 10 parts by weight to 2000 parts by weight and preferably 20 parts by weight to 1000 parts by weight with respect to 100 parts by weight of the pigment. When the content is from 10 parts by weight to 2000 parts by weight, the viscosity of the pigment dispersion does not increase, and the space during storage can be reduced.

The pigment dispersion 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 of the present invention is added to the organic solvent (or vehicle) and dispersed.
2) A method in which the pigment and the pigment dispersant are separately added and dispersed in the organic solvent (or vehicle).
3) A method in which the pigment and the pigment dispersant of the present invention are separately dispersed in advance in the organic solvent (or vehicle), and the resulting dispersion is mixed (in this case, the pigment dispersant is added only with the organic solvent). May be dispersed).
4) A method of adding the pigment dispersant of the present invention to the obtained dispersion after dispersing the pigment in the organic solvent (or vehicle).

  The vehicle refers to a portion of the medium in which the pigment is dispersed when the paint is in a liquid state, and is a liquid component that binds to the pigment and hardens the coating film (binder), and dissolves and dilutes it. And a component (the organic solvent).

  The disperser used when 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.

  Formation of a colored image using the pigment dispersion of the present invention is performed, for example, by applying a coating liquid containing the pigment dispersion on a support and drying to form a layer of the pigment dispersion, or a temporary support. The pigment dispersion layer formed above is transferred onto a support, on which a known positive or negative photosensitive resin composition layer is formed, exposed, developed, and then unexposed. It can be carried out by a method of removing the layer of the pigment dispersion in the same region together with the layer of the photosensitive resin composition.

  The pigment dispersion of the present invention can be used for forming a color filter pixel portion by a conventionally known method. In producing a color filter pixel portion using this pigment dispersion, a pigment dispersion method is suitable.

  A typical method in this method is a photolithography method, which includes the pigment dispersion of the present invention and a photocurable compound as essential components, and an organic solvent and a thermoplastic resin in combination as necessary. Then, the photocurable composition prepared by mixing them is applied to the surface of the color filter transparent substrate on which the black matrix is provided, dried by heating (prebaked), and then irradiated with ultraviolet rays through a photomask. After pattern exposure is performed by irradiating and curing the photocurable compound at the location corresponding to the pixel portion, the unexposed portion is developed with a developer, the non-pixel portion is removed, and the pixel portion is formed on the transparent substrate. It is a method of fixing. In this method, a pixel portion made of a cured colored film of a photocurable composition is formed on a transparent substrate. By repeating this operation for each of red, green, and blue colors, a color filter having red, green, and blue colored pixel portions at predetermined positions can be manufactured.

  As another method, there is a method of forming a pixel portion by spraying ink on the surface of the substrate by an ink jet method. This is an ink-jet ink for color filters prepared by using the pigment dispersion of the present invention and a thermosetting compound as essential components, using an organic solvent and a photocurable resin in combination, if necessary, and mixing them. The composition is selectively attached to a predetermined region on the surface of the color filter on the transparent substrate provided with the black matrix by an ink jet method to form an ink layer having a predetermined pattern, and then the ink layer is heated to be cured. This is a method for fixing the pixel portion to the transparent substrate. In this method, a pixel portion made of a cured colored film of a thermosetting composition is formed on a transparent substrate.

  Among the pigment dispersion methods, the photolithography method, the manufacturing method of the color filter pixel portion by the ink jet method has been described in detail, the color filter pixel portion prepared using the pigment dispersion, other electrodeposition methods, A color filter may be manufactured by forming each color pixel portion by a transfer method, a micelle electrolysis method, a PVED (Photovoltaic Electrodeposition) method, a reverse printing method, a thermosetting method, or the like.

  The color filter uses a curable composition of each color obtained by using the pigment dispersion, encloses a liquid crystal material between a pair of parallel transparent electrodes, and divides the transparent electrode into discontinuous fine sections. A color filter coloring pixel portion selected from any one of red (R), green (G), and blue (B) is provided in each of the fine sections divided in a lattice pattern by the black matrix on the transparent electrode. It can be obtained by alternately providing a pattern, or by forming a color filter colored pixel portion on a substrate and then providing a transparent electrode.

EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, these Examples demonstrate this invention concretely and an aspect is not limited by this.
In the synthesis examples, examples and comparative examples, “parts” and “%” are all in terms of weight.

[Synthesis Example 1] Synthesis Example of Vinyl Polymer A (X1)
While maintaining 100 parts of xylene at 80 ° C. in a nitrogen stream, 68 parts of ethyl methacrylate, 29 parts of 2-ethylhexyl methacrylate, 3 parts of thioglycolic acid, and a polymerization initiator (“Perbutyl (registered trademark) O” [ The active ingredient peroxy 2-ethylhexanoate t-butyl, manufactured by Nippon Oil & Fats Co., Ltd.]) was added dropwise over 4 hours. After completion of the dropwise addition, 0.5 part of “Perbutyl (registered trademark) O” was added every 4 hours and stirred at 80 ° C. for 12 hours. After completion of the reaction, xylene was added to adjust the non-volatile content to obtain a xylene solution of a vinyl copolymer (X1) having a non-volatile content of 50% and having a carboxyl group at one end. The weight average molecular weight of the resin was 7000, the acid value was 18.0 mgKOH / g, and the glass transition temperature Tg was 38 ° C.

[Synthesis Example 2] Synthesis Example of Vinyl Copolymer (X2)
While maintaining 100 parts of xylene at 80 ° C. in a nitrogen stream, stirring, 66 parts of ethyl methacrylate, 28 parts of 2-ethylhexyl methacrylate, 6 parts of thioglycolic acid, and a polymerization initiator (“Perbutyl (registered trademark) O” [ The active ingredient peroxy 2-ethylhexanoate t-butyl, manufactured by NOF Corporation] was added dropwise over 4 hours. After completion of the dropwise addition, 0.5 part of “Perbutyl (registered trademark) O” was added every 4 hours and stirred at 80 ° C. for 12 hours. After completion of the reaction, an appropriate amount of xylene was added to adjust the non-volatile content to obtain a xylene solution of a vinyl copolymer (X2) having a non-volatile content of 50% and having a carboxyl group at one end. The weight average molecular weight of the resin was 4000, the acid value was 36.0 mgKOH / g, and the glass transition temperature Tg was 38 ° C.

[Synthesis Example 3] Synthesis example of vinyl copolymer (X3)
While maintaining 150 parts of xylene at 80 ° C. in a nitrogen stream, 64 parts of ethyl methacrylate, 27 parts of 2-ethylhexyl methacrylate, 8 parts of thioglycolic acid, and a polymerization initiator (“Perbutyl (registered trademark) O” [ The active ingredient peroxy 2-ethylhexanoate t-butyl, manufactured by NOF Corporation] was added dropwise over 4 hours. After completion of the dropwise addition, 0.5 part of “Perbutyl (registered trademark) O” was added every 4 hours and stirred at 80 ° C. for 12 hours. After completion of the reaction, an appropriate amount of xylene was added to adjust the nonvolatile content to obtain a xylene solution of a vinyl copolymer (X3) having a nonvolatile content of 40% and having a carboxyl group at one end. The weight average molecular weight of the resin was 3000, the acid value was 48.0 mgKOH / g, and the glass transition temperature Tg was 38 ° C.

[Synthesis Example 4] Synthesis example of vinyl copolymer (X4)
While maintaining 100 parts of xylene at 80 ° C. in a nitrogen stream, 28 parts of ethyl methacrylate, 66 parts of 2-ethylhexyl methacrylate, 6 parts of thioglycolic acid, and a polymerization initiator (“Perbutyl (registered trademark) O” [ The active ingredient peroxy 2-ethylhexanoate t-butyl, manufactured by NOF Corporation] was added dropwise over 4 hours. After completion of the dropwise addition, 0.5 part of “Perbutyl (registered trademark) O” was added every 4 hours and stirred at 80 ° C. for 12 hours. After completion of the reaction, an appropriate amount of xylene was added to adjust the nonvolatile content to obtain a xylene solution of a vinyl copolymer (X4) having a nonvolatile content of 50% and having a carboxyl group at one end. The weight average molecular weight of the resin was 4000, the acid value was 36.0 mgKOH / g, and the glass transition temperature Tg was 8 ° C.

[Synthesis Example 5] Synthesis Example of Vinyl Polymer A (X5)
While maintaining 100 parts of xylene at 80 ° C. in a nitrogen stream and stirring, 68 parts of 2-ethylhexyl methacrylate, 29 parts of 2-hydroxyethyl methacrylate, 3 parts of thioglycolic acid, and a polymerization initiator (“Perbutyl (registered trademark)”) O ”[active ingredient peroxy 2-ethylhexanoate t-butyl, manufactured by NOF Corporation] was added dropwise over 4 hours. After completion of the dropwise addition, 0.5 part of “Perbutyl (registered trademark) O” was added every 4 hours and stirred at 80 ° C. for 12 hours. After completion of the reaction, xylene was added to adjust the nonvolatile content to obtain a xylene solution of a vinyl copolymer (X5) having a nonvolatile content of 50% and having a carboxyl group at one end. The weight average molecular weight of the resin was 7000, the acid value was 18.0 mgKOH / g, and the glass transition temperature Tg was 10 ° C.

[Synthesis Example 6] Synthesis example of vinyl copolymer (X6)
While maintaining 100 parts of xylene at 80 ° C. in a nitrogen stream, stirring, 66 parts of ethyl methacrylate, 28 parts of dicyclopentanyl methacrylate, 6 parts of thioglycolic acid, and a polymerization initiator (“Perbutyl (registered trademark) O”) [Active ingredient t-butyl 2-ethylhexanoate, manufactured by NOF Corporation] was added dropwise over 4 hours. After completion of the dropwise addition, 0.5 part of “Perbutyl (registered trademark) O” was added every 4 hours and stirred at 80 ° C. for 12 hours. After completion of the reaction, an appropriate amount of xylene was added to adjust the non-volatile content to obtain a xylene solution of a vinyl copolymer (X6) having a non-volatile content of 50% and having a carboxyl group at one end. The weight average molecular weight of the resin was 4000, the acid value was 36.0 mgKOH / g, and the glass transition temperature Tg was 60 ° C.

[Synthesis Example 7] Synthesis example of vinyl copolymer (X7)
While maintaining 100 parts of xylene at 80 ° C. in a nitrogen stream, stirring, 66 parts of ethyl acrylate, 28 parts of 2-ethylhexyl acrylate, 6 parts of thioglycolic acid, and a polymerization initiator (“Perbutyl (registered trademark) O” [ The active ingredient peroxy 2-ethylhexanoate t-butyl, manufactured by NOF Corporation] was added dropwise over 4 hours. After completion of the dropwise addition, 0.5 part of “Perbutyl (registered trademark) O” was added every 4 hours and stirred at 80 ° C. for 12 hours. After completion of the reaction, an appropriate amount of xylene was added to adjust the non-volatile content to obtain a xylene solution of a vinyl copolymer (X7) having a non-volatile content of 50% and having a carboxyl group at one end. The weight average molecular weight of the resin was 4500, the acid value was 36.0 mgKOH / g, and the glass transition temperature Tg was -38 ° C.

<Example 1>
In a flask equipped with a stirrer, reflux condenser, nitrogen blowing tube and thermometer, 54.5 parts of xylene, vinyl copolymer (X1) obtained in Synthesis Example 1 (as vinyl copolymer (A) in the present application) Use) 19.0 parts, vinyl copolymer (X2) obtained in Synthesis Example 2 (used as vinyl copolymer (B1) in the present application) 38.0 parts, and polyallylamine 20% aqueous solution (Nittobo Co., Ltd.) "PAA-05", number average molecular weight of about 5,000) 7.5 parts is charged, stirred at 140 ° C while stirring under a nitrogen stream, and water is distilled off using a separator. The reaction was carried out at 140 ° C. for 8 hours while returning xylene to the reaction solution.
After completion of the reaction, an appropriate amount of xylene was added to adjust the nonvolatile content to obtain a pigment dispersant (1) having a nonvolatile content of 40%. The resin had a weight average molecular weight of 10,000 and an amine value of 22.0 mg KOH / g.
Next, 18.7 parts of the pigment dispersant (1), 15 parts of FASTOGEN GREEN A110 (trade name: manufactured by DIC Corporation, CI Pigment Green 58, chlorinated brominated zinc phthalocyanine pigment, pigment particle size 40 nm), 66.3 parts of propylene glycol monomethyl ether acetate (PGMAc) was dispersed with a paint conditioner for 4 hours together with 200 parts of 0.5 mmφ zircon beads to obtain a pigment dispersion liquid (1-1).
In addition, C.I. I. Instead of Pigment Green 58, C.I. I. A pigment dispersion (1-2) was obtained in the same manner as the pigment dispersion (1-1) except that 15 parts of Pigment Yellow 150 (pigment particle size 50 nm) was added.

<Example 2>
In a flask equipped with a stirrer, reflux condenser, nitrogen blowing tube and thermometer, 26.5 parts of xylene, the vinyl copolymer (X2) obtained in Synthesis Example 2 (as the vinyl copolymer (A) in the present application) Use) 24.0 parts, 40.5 parts of vinyl copolymer (X3) obtained in Synthesis Example 3 (used as vinyl copolymer (B1) in the present application), and 20% polyallylamine aqueous solution (Nittobo Industries, Ltd.) A mixture consisting of 9.0 parts of “PAA-03” manufactured by PAA-03, number average molecular weight of about 3,000) was stirred at 140 ° C. while stirring under a nitrogen stream, and water was distilled off using a separator. The reaction was carried out at 140 ° C. for 8 hours while returning xylene to the reaction solution. After completion of the reaction, an appropriate amount of xylene was added to adjust the nonvolatile content to obtain a pigment dispersant (2) having a nonvolatile content of 40%. The weight average molecular weight of the resin was 8,000, and the amine value was 16.0 mg KOH / g.
Next, in Example 1, except that the polymer of the pigment dispersant (1) was replaced with the pigment dispersant (2), the pigment dispersion liquid (2-1) and the pigment dispersion liquid ( 2-2) was obtained.

<Example 3>
In a flask equipped with a stirrer, reflux condenser, nitrogen blowing tube and thermometer, 5.4 parts of a 20% aqueous solution of polyallylamine “PAA-03” and polyethylene glycol monomethacrylate (“Blemmer PE350” manufactured by NOF Corporation) , 0.7 parts of average ethylene glycol chain (used as (meth) acrylate (C) in the present application) was charged, stirred at 50 ° C. with stirring under a nitrogen stream, and reacted for 3 hours. Next, 37.5 parts of xylene and 56.4 parts of the vinyl copolymer (X1) obtained in Synthesis Example 1 (used as the vinyl copolymer (A) in the present application) were charged and stirred at 140 ° C. while stirring under a nitrogen stream. Then, water was distilled off using a separator, and the reaction was performed at 140 ° C. for 8 hours while returning xylene to the reaction solution. After completion of the reaction, an appropriate amount of xylene was added to adjust the nonvolatile content to obtain a pigment dispersant (3) having a nonvolatile content of 40%. The weight average molecular weight of the resin was 13,000, and the amine value was 16.0 mg KOH / g.
Subsequently, in Example 1, except that the polymer of the pigment dispersant (1) was replaced with the pigment dispersant (3), the pigment dispersion (3-1) and the pigment dispersion ( 3-2) was obtained.

<Example 4>
In a flask equipped with a stirrer, reflux condenser, nitrogen blowing tube, and thermometer, 10.5 parts of 20% aqueous solution of polyallylamine “PAA-03” and polyethylene glycol-polypropylene glycol monomethacrylate (manufactured by NOF Corporation) "Blemmer 70PEP-350B", average ethylene glycol chain number 5, average propylene glycol chain number 2) (used as (meth) acrylate (C) in the present application) 1.5 parts were charged and stirred at 50 ° C while stirring under a nitrogen stream And allowed to react for 3 hours. Next, 35.2 parts of xylene and 52.8 parts of the vinyl copolymer (X2) obtained in Synthesis Example 2 (used as the vinyl copolymer (A) in the present application) were charged and stirred at 140 ° C. while stirring under a nitrogen stream. Then, water was distilled off using a separator, and the reaction was performed at 140 ° C. for 8 hours while returning xylene to the reaction solution. After completion of the reaction, an appropriate amount of xylene was added to adjust the nonvolatile content to obtain a pigment dispersant (4) having a nonvolatile content of 40%. The weight average molecular weight of the resin was 8,000, and the amine value was 31.0 mg KOH / g.
Next, in Example 1, except that the polymer of the pigment dispersant (1) was replaced with the pigment dispersant (4), the same procedures as in Example 1 were performed for the pigment dispersion (4-1) and the pigment dispersion ( 4-2) was obtained.

<Example 5>
In Example 1, the vinyl copolymer (X2) was replaced with the vinyl copolymer (X4) obtained in Synthesis Example 4 (used as the vinyl copolymer (B1) or vinyl copolymer (B2) in the present application). Except for the above, a pigment dispersant (5) having a nonvolatile content of 40% was obtained in the same manner as in Example 1. The resin had a weight average molecular weight of 11,000 and an amine value of 23.0 mg KOH / g.
Subsequently, in Example 1, except that the polymer of the pigment dispersant (1) was replaced with the pigment dispersant (5), the pigment dispersion (5-1) and the pigment dispersion ( 5-2) was obtained.

<Example 6>
In Example 2, the vinyl copolymer (X3) was replaced with the vinyl copolymer (X5) obtained in Synthesis Example 5 (used as the vinyl copolymer (B1) or vinyl copolymer (B2) in the present application). Except for the above, a pigment dispersant (6) having a nonvolatile content of 40% was obtained in the same manner as in Example 2. The resin had a weight average molecular weight of 10,000 and an amine value of 21.0 mg KOH / g.
Subsequently, in Example 1, except that the polymer of the pigment dispersant (1) was replaced with the pigment dispersant (6), the pigment dispersion (6-1) and the pigment dispersion ( 6-2) was obtained.

<Example 7>
In a flask equipped with a stirrer, a reflux condenser, a nitrogen blowing tube, and a thermometer, 34.6 parts of xylene, the vinyl copolymer (X6) obtained in Synthesis Example 6 (as the vinyl copolymer (A) in the present application) Use) 33.6 parts, vinyl copolymer (X7) obtained in Synthesis Example 7 (used as vinyl copolymer (B2) in the present application) 22.8 parts, and polyallylamine 20% aqueous solution (Nittobo Co., Ltd.) A mixture consisting of 9.0 parts of “PAA-03” manufactured by PAA-03, number average molecular weight of about 3,000) was stirred at 140 ° C. while stirring under a nitrogen stream, and water was distilled off using a separator. The reaction was carried out at 140 ° C. for 8 hours while returning xylene to the reaction solution. After completion of the reaction, an appropriate amount of xylene was added to adjust the nonvolatile content to obtain a pigment dispersant (7) having a nonvolatile content of 40%. The weight average molecular weight of the resin was 8,000, and the amine value was 27.0 mg KOH / g.
Subsequently, in Example 1, except that the polymer of the pigment dispersant (1) was replaced with the pigment dispersant (7), the pigment dispersion (7-1) and the pigment dispersion ( 7-2) was obtained.

<Example 8>
In a flask equipped with a stirrer, reflux condenser, nitrogen blowing tube and thermometer, 46.7 parts of xylene, the vinyl copolymer (X1) obtained in Synthesis Example 1 (as the vinyl copolymer (A) in the present application) Use) 40.5 parts, a polyester having a carboxyl group at the terminal obtained by polymerizing 12-hydroxystearic acid and ε-caprolactone by a conventional method (used as polymer (D) in the present application) (number average molecular weight 3000, acid value) 18.5) A mixture consisting of 9.0 parts and 3.8 parts of a 20% aqueous solution of polyallylamine “PAA-03” was charged and stirred at 140 ° C. with stirring under a nitrogen stream, and water was removed using a separator. The reaction was conducted at 140 ° C. for 8 hours while distilling off and returning xylene to the reaction solution. After completion of the reaction, an appropriate amount of xylene was added to adjust the nonvolatile content to obtain a pigment dispersant (8) having a nonvolatile content of 40%. The weight average molecular weight of the resin was 12,000, and the amine value was 4.0 mg KOH / g.
Next, in Example 1, except that the polymer of the pigment dispersant (1) was replaced with the pigment dispersant (8), the pigment dispersion (8-1) and the pigment dispersion ( 8-2) was obtained.

<Example 9>
In a flask equipped with a stirrer, a reflux condenser, a nitrogen blowing tube, and a thermometer, 46.7 parts of xylene, the vinyl copolymer (X1) obtained in Synthesis Example 1) (the vinyl copolymer (A) in the present application) 55.7 parts, 1.1 parts of stearic acid (used as monocarboxylic acid or (meth) acrylate (E) in the present application), and 5.1 parts of a polyallylamine 20% aqueous solution “PAA-03” Was stirred at 140 ° C. while stirring under a nitrogen stream, and water was distilled off using a separator, and the reaction was performed at 140 ° C. for 8 hours while returning xylene to the reaction solution. After completion of the reaction, an appropriate amount of xylene was added to adjust the nonvolatile content to obtain a pigment dispersant (9) having a nonvolatile content of 40%. The resin had a weight average molecular weight of 11,000 and an amine value of 4.5 mg KOH / g.
Next, in Example 1, except that the polymer of the pigment dispersant (1) was replaced with the pigment dispersant (9), the pigment dispersion (9-1) and the pigment dispersion ( 9-2) was obtained.

<Comparative Example 1>
In a flask equipped with a stirrer, reflux condenser, nitrogen blowing tube, and thermometer, 36.8 parts of xylene, 57.9 parts of the vinyl copolymer (X1) obtained in Synthesis Example 1, and 20% aqueous solution of polyallylamine “ A mixture consisting of 5.3 parts of PAA-03 "was charged and stirred at 140 ° C while stirring under a nitrogen stream, and water was distilled off using a separator, and xylene was returned to the reaction solution for 8 hours. The reaction was performed at 140 ° C. After completion of the reaction, an appropriate amount of xylene was added to adjust the nonvolatile content, and a pigment dispersant (ratio-1) having a nonvolatile content of 40% was obtained. The weight average molecular weight of the resin was 8,000, and the amine value was 16.0 mg KOH / g.
Next, in Example 1, except that the polymer of the pigment dispersant (1) was replaced with the pigment dispersant (ratio-1), the pigment dispersion (ratio-1-1) and A pigment dispersion (ratio-1-2) was obtained.

<Comparative example 2>
In a flask equipped with a stirrer, reflux condenser, nitrogen blowing tube, and thermometer, 36.8 parts of xylene, 57.9 parts of the vinyl copolymer (X2) obtained in Synthesis Example 1, and 20% aqueous solution of polyallylamine “ A mixture consisting of 5.3 parts of PAA-03 "was charged and stirred at 140 ° C while stirring under a nitrogen stream, and water was distilled off using a separator, and xylene was returned to the reaction solution for 8 hours. The reaction was performed at 140 ° C. After completion of the reaction, an appropriate amount of xylene was added to adjust the nonvolatile content to obtain a pigment dispersant (ratio-2) having a nonvolatile content of 40%. The resin had a weight average molecular weight of 8,000 and an amine value of 20.0 mg KOH / g.
Next, in Example 1, except that the polymer of the pigment dispersant (1) was replaced with the pigment dispersant (ratio-2), the pigment dispersion (ratio 2-1) and A pigment dispersion (ratio 2-2) was obtained.

<Performance tests and evaluation criteria>
(Pigment particle size determination)
After adding PGMAc to the pigment dispersion and diluting it 1000 times, the particle size of the dispersed pigment is measured using a particle size analyzer (“FPAR-1000” manufactured by Otsuka Electronics Co., Ltd.) to obtain the initial particle size. Judgment was made based on the following three criteria.
○ Particle size less than 100 nm.
Δ: Particle size of 100 nm to less than 130 nm.
X Particle size of 130 nm or more.

(Storage stability of pigment dispersion)
After allowing the pigment dispersion to stand at 40 ° C. for 7 days, the particle size of the pigment dispersed in the sample was measured using the particle size analyzer.
When the rate of change of the measured value relative to the initial particle diameter was 10% or less, “○” was evaluated, and when the rate of change was more than 10%, “X” was evaluated

(Coating film creation)
75.00 parts of pigment dispersion, 8.50 parts of polyester acrylate resin (Aronix M7100, manufactured by Toa Gosei Kagaku Kogyo Co., Ltd.) and 16.5 parts of PGMAc are mixed, filtered through a filter with a pore size of 1.0 μm, and ink for color filters Got. The color filter ink was applied to 1 mm thick glass using a spin coater so as to have a dry film thickness of 1 μm, and then preliminarily dried at 90 ° C. for 5 minutes to form a coating film. Next, the obtained coating film was heat-treated at 230 ° C. for 15 minutes to obtain a color filter pixel portion.

(Luminance)
Luminance (Y value) is calculated using a spectrophotometer MCPD-3000 manufactured by Otsuka Electronics Co., Ltd., and the chromaticity coordinate x value and y value are calculated by F10 light source colorimetry. In addition, the Y value in CIE color development system chromaticity was measured. Here, it was evaluated that the visual brightness was higher as the luminance (Y value) was higher.

(contrast)
The color filter blue pixel portion was installed between two polarizing plates, a light source was installed on one side, and a CCD camera was installed on the opposite side to measure the luminance. It was calculated from the ratio of luminance (transmitted light intensity) between when the polarization axis was parallel and when it was vertical.

  The performance test results of the pigment dispersion of the present invention are summarized in Tables 1 and 2.

Table 1 is a pigment dispersion of FASTOGEN GREEN A110. All the pigment dispersions of the examples had a contrast of more than 7000.
Comparative Examples 1-1-1 and 1-1-2 were inferior in dispersion stability and the contrast was also lowered.

  Table 2 shows C.I. I. Pigment Yellow 150 pigment dispersion. The pigment dispersions of the examples all had a luminance exceeding 86.5 and a contrast exceeding 5000. On the other hand, Comparative Examples 1-2-1 and 1-2-2 had large particle diameters and decreased contrast. 1-2-2 was also inferior in stability.

Claims (7)

From the vinyl copolymer (A) having at least one of a carboxyl group, a haloformyl group, and an oxycarbonyl group as a functional group that reacts with the amino group on the amino group of polyallylamine, and the following (B) to (E) A pigment dispersant comprising, as a main component, a modified polyallylamine obtained by reacting with one or more compounds selected from the group consisting of:
(1) A vinyl copolymer having a carboxyl group, a haloformyl group, or an oxycarbonyl group at one end as a functional group that reacts with an amino group, the amount of the functional group that reacts with an amino group, the copolymer composition or A vinyl copolymer (B) having a copolymer composition ratio different from that of the vinyl copolymer (A).
(2) (Meth) acrylate (C) having a polyalkylene glycol chain.
(3) A polyester having a functional group that reacts with an amino group at one end, a polyamide that has a functional group that reacts with an amino group at one end, or a polyester amide (D) that has a functional group that reacts with an amino group at one end.
(4) Monocarboxylic acid or (meth) acrylate (E). The vinyl copolymer (B) is a vinyl copolymer (B1) obtained by polymerizing a plurality of vinyl monomers ,
Molar ratio of the vinyl copolymer (A) and the vinyl copolymer (B1) (A) / ( B1) is, according to claim 1 which is (A) / (B1) = 0.25~4.0 The pigment dispersant described in 1. The modified polyallylamine is reacted with the (meth) acrylate (C) having the polyalkylene glycol chain, and the polyalkylene glycol chain has a ratio of 1 to 30% by weight based on the whole molecule. The pigment dispersant as described. The vinyl copolymer (B) is a vinyl copolymer (B2) obtained by polymerizing a plurality of vinyl monomers, the Tg of the vinyl copolymer (A) and the vinyl copolymer (B2) The difference in Tg is 20 ° C. or more, and the molar ratio (A) / (B2) between the vinyl copolymer (A) and the vinyl copolymer (B2) is (A) / (B2) = 0. The pigment dispersant according to claim 1, which is 25 to 4.0. The modified polyallylamine is a polyester having a functional group that reacts with the amino group at one end, a polyamide that has a functional group that reacts with an amino group at one end, or a polyester amide that has a functional group that reacts with an amino group at one end ( The pigment dispersant according to claim 1, having a residue of D) in a proportion of 1 to 50% by weight based on the whole molecule. The pigment dispersant according to claim 1, wherein the modified polyallylamine has a residue of the monocarboxylic acid or (meth) acrylate (E) in a proportion of 1 to 30% by weight based on the whole molecule. A pigment dispersion using the pigment dispersant according to any one of claims 1 to 6.