JP2013103993A - Phosphate group-containing block copolymer, pigment dispersant, and pigment colorant composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new phosphate group-containing block copolymer that can subject a microparticulated pigment to microdispersion at high level and can prepare a pigment colorant composition excellent in coating properties and long-term storage stability.SOLUTION: A phosphate group-containing block copolymer is an A-B block copolymer that contains 90 mass% of a structural unit derived from a methacrylate-based monomer and that consists of an A-polymer block and a B-polymer block. In the phosphate group-containing block copolymer, only the B-polymer block, out of the A-polymer block and the B-polymer block, contains a structural unit derived from a phosphate group-containing methacrylic acid-based monomer having a phosphate group.

Description

  The present invention relates to a novel phosphate group-containing block copolymer that is useful as a pigment dispersant, a method for producing the same, and a pigment dispersant and a pigment colorant composition using the phosphate group-containing block copolymer.

  With the recent rapid development of information devices, liquid crystal color displays are widely used as information display members for information devices. Applications of liquid crystal color displays include, for example, display screens for televisions, projectors, personal computers, mobile information devices, monitors, car navigation systems, mobile phones, electronic calculators, electronic dictionaries, etc .; information bulletin boards, information bulletin boards, function displays Display of plates, sign boards, etc .; shooting screens of digital cameras, video cameras, etc. A color filter is usually mounted on a liquid crystal color display. This color filter is required to have excellent color characteristics of image performance such as fineness, color density, light transmittance, and contrast, and optical characteristics.

  A color stabilizer for a color filter (hereinafter, also referred to as “color for color filter”) used for the three primary color pixels of a conventional color filter uses a dispersion stabilizer together with a pigment. Examples of the dispersion stabilizer include (a) a dye derivative generally referred to as “synergist” and having a skeleton similar to a pigment and having an acid group such as a sulfonic acid group introduced into the skeleton (hereinafter referred to as “dye derivative”). Are simply referred to as “synergists”), and (b) a combination of a basic polymer type pigment dispersant having an amino group paired with the acidic group of this synergist is often used (for example, patent documents) 1). By using such a combination of (a) a synergist and (b) a basic polymer type pigment dispersant, the dispersion stability of the pigment in an organic solvent can be improved. Furthermore, the viscosity of the pigment ink obtained can be lowered and the long-term storage stability of the ink can be improved.

  However, color filters for liquid crystal color televisions are required to further improve color display performance (pixel performance) such as color density, light transmission, and contrast ratio, and the prior art is sufficient. It is not compatible with. In response to such a demand, there is a tendency to improve the performance of the pixel by reducing the particle diameter of the pigment to be used to make ultrafine particles. However, since the number of particles of the ultrafine pigment is increased even if the mass is the same as that of the non-ultrafine pigment, the surface area is also increased. For this reason, it is difficult for the conventional technology to sufficiently maintain the dispersion stability of the ultrafine pigment.

  As a method for improving the dispersion stability of the ultrafine pigment, there is a method of increasing the use amount of a synergist having an acidic group and a pigment dispersant (for example, see Patent Document 2). However, when the usage amount of the synergist and the pigment dispersant is increased, the pigment density is relatively lowered, so that the color density (high color density of the pixel) is lowered. That is, it is very difficult to provide an ink that satisfies both the requirement of increasing the pigment content in order to increase the color density of the pixel to obtain an appropriate pixel coating composition and the dispersion stability of the pigment.

  Moreover, as a method for suppressing the relative decrease in the pigment concentration, there is a method of introducing an acidic group into the molecular structure of the pigment dispersant (see, for example, Patent Document 3). However, this method is difficult to apply to a basic pigment dispersant having an amino group. This is because if an acidic group is introduced into the molecular structure of a basic polymer type pigment dispersant used with a synergist having an acidic group, the acidic group and the amino group may be ionically bonded. When the acidic group and the amino group are ionically bonded, the pigment dispersant gels within the molecule or between the molecules in the organic solvent. Even if the pigment dispersant does not gel, there is an ionic bond within or between the pigment dispersant molecules, and the pigment dispersant and the synergist are less likely to ion bond. For this reason, the pigment dispersant having an ionic bond may not function sufficiently as a pigment dispersant.

  By the way, color filters are usually coated with color filter color on glass, then exposed to only necessary parts using a photomask or the like to insolubilize them, and then unexposed parts (unnecessary parts) are removed with an alkaline developer. Manufactured by the method of Note that a developing polymer having an acidic group such as a carboxyl group is generally added to the color for a color filter. The alkaline developer neutralizes the acidic group of the developing polymer, solubilizes the developing polymer in water and removes it. However, a basic pigment dispersant having an amino group does not dissolve in an alkali developer because an acidic group cannot be introduced into its molecular structure. For this reason, the basic pigment dispersant has caused the developability to deteriorate, for example, the development time is long or the pixel edge is not sharp.

Under such circumstances, in recent years, a method for producing a block copolymer by living radical polymerization has been developed. Various polymerization methods that can easily control the structure and molecular weight using such a production method have been developed. Specifically, the methods listed below have been extensively researched and developed.
・ Nitroxide mediated polymerization (NMP method) using dissociation and bonding of amine oxide radical (see Non-Patent Document 1)
・ Atom transfer radical polymerization (ATRP method) that uses heavy metals such as copper, ruthenium, nickel, and iron and ligands that form complexes with these heavy metals and uses halogen compounds as starting compounds. (See Patent Documents 4 and 5, Non-Patent Document 2)
・ Reversible addition-fragmentation chain transfer (RAFT method) in which dithiocarboxylic acid ester or xanthate compound is used as the starting compound and polymerization is carried out using an addition polymerizable monomer and a radical initiator ) (See Patent Document 6), and Macromolecular Design via Interchange of Xanthate (MADIX method) (see Patent Document 7)
A method using heavy metals such as organic tellurium, organic bismuth, organic antimony, antimony halide, organic germanium, and germanium halide (Degenerative transfer: DT method) (see Patent Document 8 and Non-Patent Document 3).

JP-A-9-176511 JP 2001-240780 A JP 2008-298967 A Special Table 2000-500516 JP 2000-514479 A Special Table 2000-515181 International Publication No. 1999-05099 JP 2007-277533 A

Chemical Review (2001) 101, p3661 Chemical Review (2001) 101, p3689 Journal of American Chemical Society (2002) 124, p2874, (2002) 124, p13666, (2003) 125, p8720

  According to the methods described in Patent Documents 5 to 8 and Non-Patent Documents 2 and 3, the structure and molecular weight of the resin can be easily controlled. However, living radical polymerization has practical problems as described below. For example, in the NMP method, tetramethylpiperidine oxide radical is used, but it is necessary to polymerize under a high temperature condition of 100 ° C. or higher. Moreover, in order to raise a polymerization rate, it is necessary to superpose | polymerize with a monomer alone, without using a solvent. For this reason, the polymerization conditions become more severe. Further, when a methacrylate monomer is used, there is a problem that polymerization does not proceed. Although it is possible to lower the polymerization temperature or polymerize a methacrylate monomer, it is necessary to use a special nitroxide compound.

  Further, in the ATRP method, it is necessary to use heavy metal. For this reason, it is necessary to remove heavy metals from the polymer after the polymerization, and to purify the polymer, even in trace amounts. Moreover, since waste water and waste solvent generated by refining the polymer contain heavy metals that have a high environmental load, it is necessary to remove and purify the heavy metals. In the ATRP method using copper as a catalyst, it is necessary to polymerize under an inert gas in order to prevent the catalyst from being deactivated by oxygen. There is also a method for preventing deactivation of the catalyst by adding a reducing agent such as a stannic compound or ascorbic acid. However, it is essential to sufficiently remove oxygen from the polymerization atmosphere because the polymerization may be stopped in the middle only by adding the reducing agent. Furthermore, in the method of polymerizing by forming a complex using an amine compound as a ligand, the formation of the complex is inhibited if an acidic substance is present in the polymerization system, so that it is difficult to polymerize an addition polymerizable monomer having an acid group. is there. In order to introduce an acid group into a polymer by the ATRAP method, it is necessary to polymerize a monomer in which the acid group is protected with a protecting group, and to remove the protecting group after polymerization. For this reason, it is not easy to introduce an acid group into the polymer block. As described above, since heavy metals such as copper are used in the ATRP method, it is necessary to remove these heavy metals and purify the polymer after polymerization. In addition, when an acid that inhibits complex formation between a heavy metal and a ligand is present, the polymerization does not proceed. Therefore, the ATRP method has a problem that a monomer having an acid group cannot be directly polymerized.

  In the RAFT method and the MADIX method, it is necessary to first synthesize special compounds such as dithiocarboxylic acid esters and xanthate compounds, and use these synthesized compounds. In addition, since these special compounds are sulfur-based compounds, the resulting polymer tends to have an unpleasant sulfur-based odor and may be colored. For this reason, it is necessary to remove an odor and coloring from the obtained polymer.

  Further, in the DT method, it is necessary to use heavy metals as in the ATRP method. For this reason, there is a problem that it is necessary to remove heavy metals from the obtained polymer and to purify waste water containing the generated heavy metals.

  The present invention has been made in view of such problems of the prior art, and the problem is that the finely divided pigment can be highly finely dispersed, as well as coating characteristics and long-term storage. An object of the present invention is to provide a novel phosphate group-containing block copolymer capable of preparing a pigment colorant composition having excellent stability. Furthermore, the subject of the present invention is a phosphoric acid group-containing block copolymer that has no odor or color in the obtained polymer, does not require the use of heavy metals, has a narrow molecular weight distribution (PDI), is easy and is advantageous in terms of cost. It is in providing the manufacturing method of. Another object of the present invention is to provide a pigment dispersant capable of preparing a pigment colorant composition having excellent coating properties and long-term storage stability.

  Furthermore, the subject of the present invention is excellent in coating characteristics and long-term storage stability, as well as color density, fineness, contrast and transparency of pixels equipped in information display equipment such as liquid crystal color televisions. Another object of the present invention is to provide a pigment colorant composition suitable for producing a color filter having excellent optical characteristics.

  As a result of intensive studies, the inventors have made the polymer structure an AB block type composed of an A polymer block and a B polymer block, and an AB block type composed of a solvent-soluble chain and an adsorbing chain. In addition, by including a structural unit derived from a phosphate group-containing methacrylic acid monomer having a phosphate group only in the B polymer block, the A polymer block functions as a solvent-soluble chain, and the B polymer block is an adsorptive chain. As a result, the present invention has been completed.

That is, according to the present invention, the following phosphate group-containing block copolymer is provided.
[1] It is an AB block type copolymer composed of an A polymer block and a B polymer block containing 90% by mass or more of a structural unit derived from a methacrylic acid monomer, and among the A polymer block and the B polymer block, Only the B polymer block contains a structural unit derived from a phosphoric acid group-containing methacrylic acid monomer having a phosphoric acid group.
[2] The A polymer block according to [1], wherein the A polymer block includes a structural unit derived from a carboxyl group-containing methacrylic acid monomer having a carboxyl group, and the acid value of the A polymer block is 10 to 200 mgKOH / g. Phosphate group-containing block copolymer.
[3] The phosphate group-containing block copolymer according to [2], wherein the carboxyl group-containing methacrylic acid monomer is methacrylic acid.
[4] The number average molecular weight of the A polymer block is 3,000 to 20,000, the molecular weight distribution (weight average molecular weight / number average molecular weight) is 1.6 or less, and the number average molecular weight of the B polymer block Are 200 to 3,000, the number average molecular weight is 4,000 to 23,000, and the molecular weight distribution (weight average molecular weight / number average molecular weight) is 1.6 or less. 3] The phosphate group-containing block copolymer according to any one of [3].
[5] The phosphoric acid according to any one of [1] to [4], wherein the acid value of the B polymer block is 50 to 500 mgKOH / g, and the content of the B polymer block is 5 to 40% by mass. Group-containing block copolymer.

Moreover, according to this invention, the manufacturing method of the phosphate group containing copolymer shown below is provided. [6] By the manufacturing method of the phosphate group containing block copolymer in any one of said [1]-[5]. A living radical polymerization of a monomer component containing the methacrylic acid monomer in the presence of a polymerization initiating compound and a catalyst, wherein the polymerization initiating compound is at least one of iodine and an iodine compound A method for producing a phosphate group-containing block copolymer.
[7] The catalyst is at least one compound selected from the group consisting of phosphorus halides, phosphite compounds, phosphinate compounds, imide compounds, phenol compounds, diphenylmethane compounds, and cyclopentadiene compounds. The method for producing a phosphate group-containing block copolymer according to [6].
[8] The method for producing a phosphate group-containing block copolymer according to [6] or [7], wherein a polymerization temperature at the time of the living radical polymerization is 30 to 50 ° C.

Furthermore, according to the present invention, the following pigment dispersant is provided.
[9] A pigment dispersant containing the phosphate group-containing block copolymer according to any one of [1] to [5] as a main component.

Moreover, according to this invention, the pigment colorant composition shown below is provided.
[10] A pigment colorant composition comprising the pigment dispersant according to [9] above and a pigment having a number average particle diameter of 10 to 150 nm.
[11] The pigment colorant composition according to [10], further including a pigment derivative having a basic functional group.
[12] The content of the phosphate group-containing block copolymer with respect to 100 parts of the pigment is 10 to 100 parts, and the content of the dye derivative with respect to 100 parts of the pigment is 5 to 100 parts. The pigment colorant composition described in 1.
[13] The pigment colorant composition according to any one of [10] to [12], which is used as a colorant for a color filter.

  In the phosphate group-containing block copolymer of the present invention, the A polymer block is a polymer block having compatibility with the dispersion medium, and the B polymer block is a polymer block having a strongly acidic phosphate group. That is, since the phosphoric acid group of the B polymer block is strongly ionically bonded to the basic group in the active hydrogen group (hydroxyl group, amide group, carboxyl group, thiol group, urethane group, etc.) in the structure of the pigment, The acid group-containing block copolymer adsorbs steadily to the pigment. Moreover, if the phosphate group-containing block copolymer of the present invention is used, a resin-treated pigment in which the pigment is treated with a resin can be easily obtained. That is, according to the phosphoric acid group-containing block copolymer of the present invention, it is possible to highly finely disperse a finely divided pigment and to prepare a pigment colorant composition excellent in coating characteristics and long-term storage stability. Can do. In addition, various things, such as an ion exchange resin, can be considered as a use of the phosphate group containing block copolymer of this invention. Among these, a pigment dispersant is particularly preferable. That is, since the pigment dispersant of the present invention contains the above-described phosphoric acid group-containing block copolymer as a main component, a pigment colorant composition having excellent coating properties and long-term storage stability can be prepared.

  The pigment colorant composition of the present invention can maintain a low viscosity stably for a long period of time, and is excellent in coating properties and long-term storage stability. The pigment colorant composition of the present invention can be used for paints, inks, coating agents, stationery, toners, plastics and the like. Among these, it is particularly suitable as a colorant for a color filter. That is, when the pigment colorant composition of the present invention is used as a colorant for a color filter, a liquid crystal color television having excellent optical characteristics such as pixel color density, fineness, contrast, and transparency. The color filter equipped in the information display device can be manufactured. And if the pigment colorant composition of this invention is used, the resist for color filters excellent in the developability in the case of alkali image development can be obtained.

  In the method for producing a phosphate group-containing block copolymer of the present invention, the use of a heavy metal compound is not essential, the purification of the polymer is not essential, and no special compound needs to be synthesized. Therefore, according to the method for producing a phosphoric acid group-containing block copolymer of the present invention, the target phosphoric acid group-containing block copolymer can be easily produced simply by using a relatively inexpensive material on the market. . Furthermore, the method for producing a phosphate group-containing block copolymer of the present invention has the following advantages. Polymerization conditions are mild, and polymerization can be performed under the same conditions as in conventional radical polymerization methods. That is, since conventional radical polymerization equipment can be used, no special equipment is required. Moreover, it is less susceptible to oxygen, water and light during the polymerization. Moreover, it is not necessary to purify the monomer and solvent to be used, and monomers having various functional groups can be used. For this reason, various desired functional groups can be introduced into the polymer. Furthermore, since the polymerization rate is very high, a phosphate group-containing block copolymer can be easily produced in large quantities.

1. Phosphate group-containing block copolymer (phosphate group-containing block copolymer)
Hereinafter, the details of the present invention will be described with reference to an embodiment for carrying out the present invention. The phosphoric acid group-containing block copolymer of the present invention is an AB block type copolymer comprising an A polymer block and a B polymer block containing 90% by mass or more of a structural unit derived from a methacrylic acid monomer. And among A polymer block and B polymer block, only B polymer block contains the structural unit derived from the methacrylic acid type monomer (phosphoric acid group containing methacrylic acid type monomer) which has a phosphoric acid group. Hereinafter, the phosphoric acid group-containing block copolymer is also referred to as “AB block copolymer”.

  The phosphate group-containing block copolymer of the present invention is an AB block type copolymer. The A polymer block is considered to be a block having a function of dissolving or compatible with the medium to be dispersed. On the other hand, since the B polymer block has a phosphate group in its structure, it is considered that this phosphate group has a function of binding and adsorbing to a pigment or a pigment treated with a basic group-containing dye derivative. . The adsorption of the pigment and the B polymer block is, for example, a hydrogen bond between an active hydrogen group (hydroxyl group, amide group, carboxyl group, thiol group, urethane group, etc.) in the structure of the pigment and a phosphate group, or a basic pigment or This is presumably due to an ionic bond between the basic group of the pigment treated with the basic group-containing dye derivative and the phosphate group. Due to the structure and action peculiar to such an AB block type copolymer, the B polymer block is adsorbed on the surface of the finely divided pigment by ion bonding or the like, and the A polymer block is dissolved or compatible in the dispersion medium. In addition, the steric repulsion or electrical repulsion of the A polymer block prevents pigment aggregation. Therefore, the phosphoric acid group-containing block copolymer of the present invention can prepare a pigment colorant composition excellent in coating characteristics and long-term storage stability while being able to highly finely disperse the finely divided pigment. It is considered possible. Hereinafter, the term “pigment” simply refers to (i) the pigment itself and (ii) a pigment surface-treated with a basic group-containing dye derivative.

  When the phosphoric acid group-containing block copolymer is composed of an A polymer block having a carboxyl group and a B polymer block having a phosphoric acid group, any acid group may be ion-bonded and adsorbed on the pigment. There is a possibility that the assumption of However, the phosphoric acid group is a group that exhibits stronger acidity than the carboxyl group. That is, since the pKa value of the phosphate group is lower than the pKa of the carboxyl group, it is considered that the B polymer block having a phosphate group is selectively adsorbed on the pigment.

  The phosphoric acid group-containing block copolymer contains 90% by mass or more, preferably 95% by mass or more of a structural unit derived from a methacrylic acid monomer, and more preferably 100% of a structural unit derived from a methacrylic acid monomer. Is. In the production method (polymerization method) of the phosphoric acid group-containing block copolymer of the present invention described later, a methacrylic acid monomer is particularly preferably applied as the monomer. Vinyl-based monomers such as styrene, acrylate-based monomers, and vinyl ether-based monomers cause problems such as the iodine bound to the polymerization terminal being too stabilized and need to be heated to dissociate or not dissociate. there is a possibility. For this reason, when a monomer other than the methacrylic acid monomer is used in a large amount, there is a possibility that a target specific structure is not obtained or a molecular weight distribution is widened. However, even if it is monomers other than a methacrylic acid-type monomer, you may use it in the range which does not impair the objective of this invention as needed.

(A polymer block)
Examples of the methacrylic acid monomer used for constituting the A polymer block include conventionally known monomers and are not particularly limited. Specific examples include methyl methacrylate, ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, butyl methacrylate, 2-methylpropane methacrylate, t-butyl methacrylate, pentyl methacrylate, hexyl methacrylate, octyl methacrylate, 2-ethylhexyl methacrylate, nonyl methacrylate, decyl methacrylate. , Isodecyl methacrylate, lauryl methacrylate, tetradecyl methacrylate, octadecyl methacrylate, behenyl methacrylate, isostearyl methacrylate, cyclohexyl methacrylate, t-butylcyclohexyl methacrylate, isobornyl methacrylate, trimethylcyclohexyl methacrylate, cyclodecyl methacrylate (Cyclo) alkyl methacrylates such as cyclodecylmethyl methacrylate, tricyclodecyl methacrylate and benzyl methacrylate; aryl methacrylates such as phenyl methacrylate and naphthyl methacrylate; alkenyl methacrylates such as allyl methacrylate; (poly) ethylene glycol monomethyl ether methacrylate; (poly) Glycol monoalkyl ether methacrylates such as ethylene glycol monolauryl ether methacrylate and (poly) propylene glycol monomethyl ether methacrylate;

  Glycidyl group-containing methacrylates such as glycidyl methacrylate, 3,4-epoxycyclohexyl methacrylate, methacryloyloxyethyl glycidyl ether, methacryloyloxyethoxyethyl glycidyl ether; (meth) acryloyloxyethyl isocyanate, 2- (2-isocyanatoethoxy) Ethyl methacrylate and isocyanate group-containing methacrylates in which the isocyanate groups of these compounds are blocked with ε-caprolactone, MEK oxime, pyrazole and the like; cyclic methacrylates such as tetrahydrofurfuryl methacrylate and oxetanyl methyl methacrylate; octafluorooctyl methacrylate, tetrafluoroethyl Halogen-containing methacrylates such as methacrylate; 2- (4-ben Methacrylates that absorb ultraviolet rays such as xyl-3-hydroxyphenoxy) ethyl methacrylate and 2- (2′-hydroxy-5-methacryloyloxyethylphenyl) -2H-benzotriazole; have trimethoxysilyl groups and dimethylsilicone chains A silicon atom containing methacrylate etc. can be mentioned. Moreover, the macromonomer etc. which are obtained by introduce | transducing a (meth) acryl group into the one terminal of the oligomer obtained by superposing | polymerizing these monomers can be used.

  However, a methacrylate having an amino group such as dimethylaminoethyl methacrylate is easily ionically bonded to a carboxyl group or a phosphate group. For this reason, gelation or the like occurs, or the adsorptivity with the basic group of the pigment or the like is inhibited, so it should not be used.

The A polymer block preferably includes a structural unit derived from a methacrylic acid monomer having a carboxyl group (carboxyl group-containing methacrylic acid monomer).
The A polymer block into which the carboxyl group is introduced is ionized by being neutralized with an alkali and dissolved in water. Therefore, it can be suitably used in alkali development in the color filter manufacturing process. Specific examples of carboxyl group-containing methacrylic monomers include: methacrylic acid; methacrylate obtained by reacting 2-hydroxyethyl methacrylate with dibasic acid such as phthalic acid; hydroxyl group and carboxyl obtained by reacting glycidyl methacrylate with phthalic acid Examples thereof include methacrylate having a group. Of these, methacrylic acid having a small molecular weight and high polymerizability is preferable. When methacrylic acid is used as the carboxyl group-containing methacrylic monomer, problems such as remaining without polymerization are unlikely to occur.

  When the A polymer block of the phosphate group-containing block copolymer has a carboxyl group, the acid value of the A polymer block is preferably 10 to 200 mgKOH / g, and more preferably 20 to 150 mgKOH / g. When the acid value of the A polymer block is within the above numerical range, it can be used, for example, as a component suitable for alkali development in the production process of a color filter. When the acid value of the A polymer block is less than 10 mgKOH / g, even if it is neutralized with an alkali, it does not dissolve or the dissolution rate tends to be slow. On the other hand, when the acid value of the A polymer block is more than 200 mgKOH / g, the hydrophilicity of the exposed and hardened portion is improved, the water resistance is lowered, and the formed pixel becomes messy. There is.

  The number average molecular weight of the A polymer block is preferably 3,000 to 20,000, and more preferably 4,000 to 10,000. If the number average molecular weight of the A polymer block is less than 3,000, among the phosphate group-containing block copolymers adsorbed on the pigment, the steric repulsion of the A polymer block does not act and the stability may be lacking. On the other hand, if the number average molecular weight of the A polymer block is more than 20,000, the portion that dissolves or is compatible with the dispersion medium increases, so that the viscosity may increase excessively or the developability may decrease. .

  The molecular weight distribution (PDI = weight average molecular weight / number average molecular weight) of the A polymer block is preferably 1.6 or less, and more preferably 1.5 or less. According to the method for producing a phosphate group-containing block copolymer of the present invention described later, such a phosphate group-containing block copolymer having a narrow molecular weight distribution can be produced. When the molecular weight distribution (PDI) of the A polymer block is more than 1.6, the number average molecular weight is less than 3,000 or more than 20,000. It may decrease or the viscosity may increase excessively.

(B polymer block)
As the methacrylic acid monomer having a phosphoric acid group (phosphoric acid group-containing methacrylic acid monomer) used for constituting the B polymer block, conventionally known ones can be exemplified, and there is no particular limitation. Specific examples include 2- (methacryloyloxy) ethyl phosphate, 3-chloro-2- (phosphonooxy) propyl methacrylate, 2- (methacryloyloxy) propyl phosphate, 2- (phenoxyphosphonyloxy) ethyl methacrylate, Examples include acid phosphooxypolyoxyethylene glycol monomethacrylate, acid phosphooxypolyoxypropylene glycol monomethacrylate, and the like. In addition, a phosphate group-containing block copolymer from which bifunctional methacrylates such as bis (2-methacryloyloxyethyl phosphate) can be obtained can be used as long as it does not gel. Furthermore, you may copolymerize the 1 or more types of monomer (other monomer) used in order to comprise the above-mentioned A polymer block, and a phosphoric acid group containing methacrylic acid type monomer. Since the phosphoric acid group-containing methacrylic acid monomer has a lower polymerization property than other monomers, it is more preferable to copolymerize with other monomers.

  In addition, after preparing a polymer block having a hydroxyl group using a methacrylic acid monomer having a hydroxyl group, a phosphorylating reagent is introduced by reacting the hydroxyl group with this hydroxyl group to produce a B polymer block having a phosphate group. May be. Furthermore, a B polymer block may be produced by polymerizing a methacrylic acid monomer containing a phosphoric acid group obtained by reacting a methacrylic acid monomer having a hydroxyl group with a phosphorylating reagent. Specific examples of the methacrylic acid monomer having a hydroxyl group include 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, and polyethylene glycol monomethacrylate. Specific examples of the phosphorylating reagent include phosphorus pentoxide, phosphorus oxychloride, polyphosphoric acid, phosphoric acid and the like.

  The number average molecular weight of the B polymer block is preferably 200 to 3,000, and more preferably 500 to 2,000. The number average molecular weight of the B polymer block is represented by a value obtained by subtracting the number average molecular weight of the A polymer block from the number average molecular weight of the phosphate group-containing block copolymer (AB block copolymer). When the number average molecular weight of the B polymer block is less than 200, the adsorptive power to the pigment is weak and the stability may be lacking. On the other hand, if the number average molecular weight of the B polymer block is more than 3,000, it is too large and adsorbs between pigment particles, which may result in lack of stability.

  The acid value of the B polymer block is preferably 50 to 500 mgKOH / g, and more preferably 100 to 350 mgKOH / g. If the acid value of the B polymer block is less than 50 mgKOH / g, the adsorptivity to the pigment may be insufficient. On the other hand, if the acid value of the B polymer block is more than 500 mgKOH / g, the portion adsorbed on the pigment becomes excessive, and the pigment may rather aggregate.

  The content of the B polymer block in the phosphate group-containing block copolymer is preferably 5 to 40% by mass, and more preferably 10 to 30% by mass. When the content of the B polymer block is less than 5% by mass, the portion adsorbed to the pigment is too small, so that it tends to be detached and the dispersibility of the pigment tends to decrease. On the other hand, when the content of the B polymer block is more than 40% by mass, the content of the A polymer block, which is a part that is dissolved or compatible with the dispersion medium, is relatively small, and thus the dispersion stability tends to decrease. .

  From the above, the number average molecular weight of the phosphoric acid group-containing block copolymer is preferably 4,000 to 23,000, and more preferably 5,000 to 14,000. The molecular weight distribution (PDI) of the phosphate group-containing block copolymer is preferably 1.6 or less, and more preferably 1.5 or less.

  Since the phosphate group-containing block copolymer of the present invention has a phosphate group, it is expected to be applied to various applications. Specifically, it can be suitably used as a pigment dispersant and a resin component for a resin-treated pigment.

2. Method for Producing Phosphate Group-Containing Block Copolymer The method for producing a phosphate group-containing block copolymer of the present invention is a method for producing the above-mentioned phosphate group-containing block copolymer. In the presence of a polymerization initiating compound and a catalyst, a methacrylic acid type It includes a step (polymerization step) of subjecting the monomer component containing the monomer to living radical polymerization. The polymerization initiating compound is at least one of iodine and an iodine compound. The phosphate group-containing block copolymer of the present invention can be synthesized (manufactured) by a conventional living radical polymerization method. However, it is preferably produced by the method for producing a phosphate group-containing block copolymer of the present invention.

(Polymerization process)
In the polymerization step, at least one of iodine and an iodine compound is used as a polymerization initiating compound, and a monomer component containing a methacrylic acid monomer is polymerized by living radical polymerization. When heat or light is applied to iodine or iodine compound used as a polymerization initiating compound, iodine radicals are dissociated. Then, after the monomer is inserted in a state in which the iodine radical is dissociated, the iodine radical is immediately bonded again to the polymer terminal radical and stabilized, and the polymerization reaction proceeds while preventing the termination reaction.

  Specific examples of the iodine compound include alkyl iodides such as 2-iodo-1-phenylethane and 1-iodo-1-phenylethane; 2-cyano-2-iodopropane, 2-cyano-2-iodobutane, 1 -Cyano-1-containing iodide such as cyano-1-iodocyclohexane, 2-cyano-2-iodo-2,4-dimethylpentane, 2-cyano-2-iodo-4-methoxy-2,4-dimethylpentane, etc. Can be mentioned.

  As these iodine compounds, commercially available products may be used as they are, but those prepared by a conventionally known method can also be used. For example, an iodine compound can be obtained by reacting an azo compound such as azobisisobutyronitrile with iodine. Further, the iodine compound can be obtained by reacting an organic halide obtained by substituting iodine of the iodine compound with a halogen atom such as bromine or chlorine with an iodide salt such as quaternary ammonium iodide or sodium iodide, and performing halogen exchange. Can be obtained.

  In the polymerization step, a catalyst capable of extracting iodine of the polymerization initiating compound is used together with the polymerization initiating compound. Examples of catalysts include phosphorus compounds such as phosphorus halides, phosphite compounds, and phosphinate compounds; nitrogen compounds such as imide compounds; oxygen compounds such as phenol compounds; diphenylmethane compounds and cyclopentadiene compounds. It is preferable to use the following hydrocarbon compound. In addition, these catalysts can be used individually by 1 type or in combination of 2 or more types.

  Specific examples of the phosphorus compound include phosphorus triiodide, diethyl phosphite, dibutyl phosphite, ethoxyphenyl phosphinate, and phenylphenoxy phosphinate. Specific examples of the nitrogen compound include succinimide, 2,2-dimethylsuccinimide, maleimide, phthalimide, N-iodosuccinimide, and hydantoin. Specific examples of the oxygen-based compound include phenol, hydroquinone, methoxyhydroquinone, t-butylphenol, catechol, and di-t-butylhydroxytoluene. Specific examples of the hydrocarbon compound include cyclohexadiene and diphenylmethane.

  The amount of the catalyst used (number of moles) is preferably less than the amount of use of the polymerization initiating compound (number of moles). When the amount of the catalyst used (number of moles) is too large, the polymerization is controlled too much and the polymerization may not proceed easily. Moreover, it is preferable that the temperature (polymerization temperature) in the case of living radical polymerization shall be 30-50 degreeC. If the polymerization temperature is too high, iodine at the polymerization terminal may be decomposed by methacrylic acid, and the terminal may not be stable and living polymerization may not occur.

  In the polymerization step, a polymerization initiator that can generate radicals is usually added. As the polymerization initiator, conventionally known azo initiators and peroxide initiators are used. It is preferable to use a polymerization initiator that generates radicals sufficiently within the above polymerization temperature range. Specifically, it is preferable to use an azo initiator such as 2,2'-azobis (4-methoxy-2,4-dimethylvaleronitrile). The amount of the polymerization initiator used is preferably 0.001 to 0.1 mol times, more preferably 0.002 to 0.05 mol times with respect to the monomer. If the amount of the polymerization initiator used is too small, the polymerization reaction may not proceed sufficiently. On the other hand, if the amount of the polymerization initiator used is too large, a normal radical polymerization reaction that is not a living radical polymerization reaction may proceed as a side reaction.

  Living radical polymerization may be bulk polymerization that does not use an organic solvent, but is preferably solution polymerization that uses an organic solvent. The organic solvent is preferably one that can dissolve components such as a polymerization initiator compound, a catalyst, a monomer component, and a polymerization initiator. Specific examples of organic solvents include hexane, octane, decane, isodecane, cyclohexane, methylcyclohexane, toluene, xylene, ethylbenzene and other hydrocarbon solvents; methanol, ethanol, propanol, isopropanol, butanol, isobutanol, hexanol, benzyl alcohol , Alcohol solvents such as cyclohexanol; ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, methyl cellosolve, ethyl cellosolve, butyl cellosolve, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol propyl ether, diglyme, triglyme, diplopro Pilin glycol dimethyl ether, butyl carbitol, Tilt triethylene glycol, methyl dipropylene glycol, methyl cellosolve acetate, propylene glycol monomethyl ether acetate, dipropylene glycol butyl ether acetate, glycol solvents such as diethylene glycol monobutyl ether acetate;

  Ether solvents such as diethyl ether, dipropyl ether, methylcyclopropyl ether, tetrahydrofuran, dioxane, anisole; ketone solvents such as methyl ethyl ketone, diethyl ketone, methyl isobutyl ketone, cyclohexanone, isophorone, acetophenone; methyl acetate, ethyl acetate, acetic acid Ester solvents such as butyl, propyl acetate, methyl butyrate, ethyl butyrate, caprolactone, methyl lactate and ethyl lactate; halogenated solvents such as chloroform and dichloroethane; amides such as dimethylformamide, dimethylacetamide, pyrrolidone, N-methylpyrrolidone and caprolactam Other solvents, dimethyl sulfoxide, sulfolane, tetramethyl urea, ethylene carbonate, propylene carbonate, dimethyl carbonate Etc. can be mentioned. In addition, these organic solvents can be used individually by 1 type or in combination of 2 or more types.

  In the case of solution polymerization, the solid content concentration (monomer concentration) of the polymerization solution is preferably 5 to 80% by mass, and more preferably 20 to 60% by mass. When the solid content concentration of the polymerization solution is less than 5% by mass, the monomer concentration may be too low to complete the polymerization. On the other hand, when the solid content concentration of the polymerization liquid is more than 80% by mass or bulk polymerization, the viscosity of the polymerization liquid is too high, and stirring tends to be difficult and the polymerization yield tends to decrease. Living radical polymerization is preferably carried out until the monomer runs out. Specifically, the polymerization time is preferably 0.5 to 48 hours, and more preferably 1 to 24 hours. The polymerization atmosphere is not particularly limited, and may be an atmosphere in which oxygen exists within a normal range or a nitrogen stream atmosphere. Moreover, the material (monomer etc.) used for superposition | polymerization may use what removed the impurity by distillation, activated carbon treatment, an alumina treatment, etc., and may use a commercial item as it is. Furthermore, polymerization may be performed under light shielding, or polymerization may be performed in a transparent container such as glass.

  The polymerization order of the AB block copolymer is as follows: (i) the monomer constituting the A polymer block is polymerized to form the A polymer block, and then (ii) the monomer constituting the B polymer block is added for further polymerization. It is preferable. When the monomer constituting the B polymer block is polymerized first, the polymerization may not be completed and the monomer having a phosphate group may remain in the reaction system. In such a case, a monomer having a phosphate group may be easily introduced into the A polymer block. On the other hand, if the monomer constituting the A polymer block is polymerized first, even if the polymerization is not completed and the monomer remains in the reaction system, If the B polymer block is introduced so that 90% by mass or more is a (meth) acrylate monomer, an AB block copolymer can be easily obtained. Preferably, the polymerization rate is 50% or more, more preferably the polymerization rate is 80% or more, and the A polymer block is formed by polymerizing the monomers constituting the A polymer block until the polymerization rate becomes 100%. What is necessary is just to add the monomer which comprises a block and to form B polymer block.

The molecular weight of the resulting AB block copolymer can be controlled by adjusting the amount of the polymerization initiating compound used. Specifically, an AB block copolymer having an arbitrary molecular weight can be obtained by appropriately setting the number of moles of the monomer with respect to the number of moles of the polymerization initiating compound. For example, when 1 mol of a polymerization initiating compound is used and 500 mol of a monomer having a molecular weight of 100 is used for polymerization, an AB block copolymer having a theoretical molecular weight of “1 × 100 × 500 = 50,000” can be obtained. it can. That is, the theoretical molecular weight of the AB block copolymer can be calculated by the following formula (1). The above “molecular weight” is a concept including both the number average molecular weight (Mn) and the weight average molecular weight (Mw).
“Theoretical molecular weight of AB block copolymer” = “1 mol of polymerization initiating compound” × “monomer molecular weight” × “number of moles of monomer / number of moles of polymerization initiating compound” (1)

  In addition, since a polymerization process may involve a bimolecular termination or a disproportionation side reaction, an AB block copolymer having the above theoretical molecular weight may not be obtained. The AB block copolymer is preferably obtained without causing these side reactions. However, even if the molecular weight of the AB block copolymer obtained by coupling is somewhat increased, the molecular weight of the AB block copolymer obtained by stopping the polymerization reaction in the middle may be slightly decreased. The polymerization rate may not be 100%. Furthermore, once the polymerization is completed, the polymerization may be completed by adding a polymerization initiating compound or a catalyst and consuming the remaining monomer. That is, the AB block copolymer should just be produced | generated.

  The obtained AB block copolymer may remain in a state in which iodine atoms derived from the polymerization initiating compound are bonded, but it is preferable to desorb iodine atoms. The method for desorbing iodine atoms from the AB block copolymer is not particularly limited as long as it is a conventionally known method. Specifically, the AB block copolymer may be heated or treated with an acid or alkali. Further, the AB block copolymer may be treated with sodium thiosulfate or the like. The detached iodine is preferably removed by treatment with an iodine adsorbent such as activated carbon or alumina.

3. Pigment Dispersant and Pigment Colorant Composition The pigment dispersant of the present invention contains the above-described phosphate group-containing block copolymer as a main component. The pigment dispersant is preferably substantially composed of a phosphate group-containing block copolymer. The pigment colorant composition of the present invention contains this pigment dispersant and a pigment having a number average particle size of 10 to 150 nm. The phosphoric acid group in the structure of the phosphoric acid group-containing block copolymer (in the B polymer block) is strongly bonded to the basic group of the pigment treated with the basic pigment or the basic group-containing dye derivative, and the B polymer block is By adsorbing to the pigment, the effect of enhancing the dispersibility of the pigment is exhibited. That is, since the pigment dispersant of the present invention is a component that disperses the pigment by this action, the type of the pigment to be dispersed is not particularly limited.

(Pigment)
As the pigment, an organic pigment, an inorganic pigment, a metal pigment such as a metal powder or fine particles, an inorganic filler, and the like can be used. Specific examples of organic pigments and inorganic pigments include quinacridone pigments, anthraquinone pigments, diketopyrrolopyrrole pigments, perylene pigments, phthalocyanine blue pigments, phthalocyanine green pigments, isoindolinone pigments, indigo thioindigo pigments. , Dioxazine pigment, quinophthalone pigment, nickel azo pigment, insoluble azo pigment, soluble azo pigment, high molecular weight azo pigment, carbon black pigment, composite oxide black pigment, iron oxide black pigment, titanium oxide black pigment, azomethine azo And red, green, blue, yellow, orange, purple, black and white pigments selected from the group consisting of black pigments and titanium oxide pigments. Specific examples of metal pigments include copper powder and aluminum flakes. Specific examples of the inorganic filler include mica pigments, natural minerals and silica.

  In addition, it is preferable to use an organic pigment or a black matrix inorganic pigment as a pigment for a color filter. Examples of the red pigment include color index (hereinafter, CI) pigment red (PR) 56, 58, 122, 166, 168, 176, 177, 178, 224, 242, 254, and 255. Examples of green pigments include C.I. I. Pigment Green (PG) 7, 36, 58, poly (14-16) bromo copper phthalocyanine, poly (12-15) brominated-poly (4-1) chlorinated copper phthalocyanine. Examples of blue pigments include C.I. I. Pigment blue (PB) 15: 1, 15: 3, 15: 6, 60, 80, and the like.

  Examples of complementary color pigments or multicolor pixel pigments for the color filter pigment include the following. Examples of yellow pigments include C.I. I. Pigment Yellow (PY) 12, 13, 14, 17, 24, 55, 60, 74, 83, 90, 93, 126, 128, 138, 139, 150, 154, 155, 180, 185, 216, 219, C . I. CI pigment violet (PV) 19, 23. Examples of black pigments for black matrix include C.I. I. CI pigment black (PBK) 6, 7, 11, 26, and a copper-manganese-iron-based composite oxide.

  The number average particle diameter of the pigment is 10 to 150 nm, preferably 20 to 80 nm. The pigment colorant composition obtained by dispersing the finely divided pigment as described above is particularly suitable as a colorant capable of producing a color filter having high transparency and high contrast. The pigment colorant composition of the present invention contains a pigment dispersant (phosphate group-containing block copolymer) that can stably finely disperse the finely divided pigment. For this reason, the pigment colorant composition of the present invention has the above-mentioned very fine pigment dispersed in a good state, and is excellent in long-term storage stability. In addition, it is preferable that the ratio of the pigment contained in a pigment colorant composition is 5-40 mass% when the whole pigment colorant composition is 100 mass%, and is 10-30 mass%. Is more preferable.

(Dye derivative)
The pigment colorant composition contains a basic dye derivative having a basic functional group so as to be ion-bonded and adsorbed with the phosphate group in the phosphate group-containing block copolymer used for the pigment dispersant. Is preferred. This dye derivative has a basic functional group introduced into the dye skeleton. As the dye skeleton, the same or similar skeleton as the pigment and the same or similar skeleton as the compound used as the pigment raw material are preferable. Specific examples of the dye skeleton include azo dye skeleton, phthalocyanine dye skeleton, anthraquinone dye skeleton, triazine dye skeleton, acridine dye skeleton, and perylene dye skeleton.

  The basic functional group introduced into the dye skeleton is preferably an amino group. The amino group to be introduced may be any of primary, secondary, and tertiary amino groups, and may be a quaternary ammonium salt. A basic functional group such as an amino group may be directly bonded to the dye skeleton, but may be bonded to the dye skeleton via a hydrocarbon group such as an alkyl group or an aryl group; an ester, ether, sulfonamide, or urethane bond. It may be bonded. For the convenience of synthesis and the strength of the bond, the basic functional group is preferably bonded to the dye skeleton via a sulfonamide.

  The content of the phosphate group-containing block copolymer in the pigment colorant composition is preferably 10 to 100 parts by mass and more preferably 10 to 50 parts by mass with respect to 100 parts by mass of the pigment. When the content of the phosphate group-containing block copolymer is less than 10 parts by mass, the dispersibility of the pigment may be insufficient. On the other hand, if the content of the phosphate group-containing block copolymer is more than 100 parts by mass, a resin that does not contribute to dispersion may be generated. Moreover, it is preferable that it is 5-100 mass parts with respect to 100 mass parts of pigments, and, as for content of the pigment derivative in a pigment colorant composition, it is more preferable that it is 10-30 mass parts. When the content of the pigment derivative is less than 5 parts by mass, the basic group that covers the surface of the pigment is reduced, so that the pigment dispersant may not be sufficiently adsorbed. On the other hand, when the content of the pigment derivative is more than 100 parts by mass, the color of the pigment derivative is likely to be obtained, and the target hue may not be achieved.

(Alkali developable polymer)
The pigment colorant composition of the present invention is obtained by using the above-described phosphoric acid group-containing block copolymer as a pigment dispersant and dispersing a pigment and, if necessary, a dye derivative in a liquid medium. In addition, when using a pigment colorant composition as a colorant for color filters, it is preferable to add an alkali developable polymer. One of the characteristics of the phosphate group-containing block copolymer used as a pigment dispersant is that it can be alkali-developed because it has a carboxyl group in its structure and is neutralized and ionized to become soluble in water. .

  The alkali-developable polymer has an acid group such as a carboxyl group in its structure, and the acid group is neutralized with an aqueous alkali solution so that it is soluble in water and can be developed. For this reason, it is considered that some alkali-developable polymers adsorb by ionic bonding with the surface of the pigment, similarly to the phosphate group-containing block copolymer. However, the phosphoric acid group in the phosphoric acid group-containing block copolymer is a group exhibiting strong acidity as compared with the carboxyl group. For this reason, even if the phosphate group-containing block copolymer and the alkali-developable polymer having a carboxyl group coexist, it is considered that the phosphate group is selectively ionically bonded to the surface of the pigment. Therefore, even when there is an alkali-developable polymer having an acid group other than a phosphate group in its structure, the phosphate group-containing block copolymer can highly finely disperse the finely divided pigment. .

  As the alkali-developable polymer, a photosensitive resin having a photosensitive group such as an unsaturated bond group or a non-photosensitive resin can be used. Specific examples of the photosensitive resin include a photosensitive cyclized rubber resin, a photosensitive phenol resin, a photosensitive polyacrylate resin, a photosensitive polyamide resin, a photosensitive polyimide resin, an unsaturated polyester resin, and a polyester. Examples thereof include acrylate resins, polyepoxy acrylate resins, polyurethane acrylate resins, polyether acrylate resins, and polyol acrylate resins. Specific examples of the non-photosensitive resin include cellulose acetate resin, nitrocellulose resin, styrene (co) polymer, polyvinyl butyral resin, aminoalkyd resin, polyester resin, amino resin-modified polyester resin, polyurethane Resin, acrylic polyol urethane resin, soluble polyamide resin, soluble polyimide resin, soluble polyamideimide resin, soluble polyesterimide resin, hydroxyethyl cellulose, styrene-maleic acid ester copolymer, (meth) acrylic acid ester Examples thereof include system (co) polymers. These alkali-developable polymers can be used singly or in combination of two or more. In addition, it is preferable that content of the alkali developable binder in a pigment colorant composition is 5-300 mass parts with respect to 100 mass parts of pigments, and it is more preferable that it is 10-100 mass parts.

  Moreover, it is preferable to make the pigment colorant composition contain an unsaturated bond group-containing block copolymer obtained by reacting a (meth) acrylate having a glycidyl group or an isocyanate group. This unsaturated bond group-containing block copolymer is a component that can be photocured to form a film. For this reason, the intensity | strength (resistance) of the pixel of a color filter can be improved. Further, the edge of the pixel can be formed sharply, and the solvent resistance of the formed pixel can be improved. The unsaturated bond group in the unsaturated bond group-containing block copolymer is preferably an acryl group or a methacryl group. These unsaturated bond groups are introduced into the unsaturated bond group-containing block copolymer by a conventionally known method.

  As the liquid medium used in the pigment colorant composition, an organic solvent is preferable. Specific examples of the organic solvent include hydrocarbon solvents such as hexane and toluene; alcohol solvents such as butanol; ester solvents such as propyl acetate and butyl acetate; ketone solvents such as cyclohexanone and methyl isobutyl ketone; diethylene glycol monobutyl ether Glycol solvents such as propylene glycol monomethyl ether; glycol ester or ether solvents such as propylene glycol monomethyl ether acetate and dipropylene glycol dibutyl ether; amide solvents such as N-methylpyrrolidone and dimethylacetamide; ethylene carbonate, propion carbonate, etc. And carbonate-based solvents. These organic solvents can be used individually by 1 type or in combination of 2 or more types.

  A conventionally known additive may be further added to the pigment colorant composition. Specific examples of the additive include an ultraviolet absorber, a leveling agent, an antifoaming agent, and a photopolymerization initiator. Moreover, you may add the monomer which has unsaturated bonds, such as a methacrylate and an acrylate, as a reactive diluent.

(Method for producing pigment colorant composition)
In producing the pigment colorant composition, the respective components may be blended at once or individually. In addition, it is preferable to add a pigment derivative when making a pigment raw material compound into a pigment or when refining the pigment. Thereby, a pigment whose surface is made basic by the action of the dye derivative (surface-treated pigment) can be obtained. Furthermore, when using the resin-treated pigment described later, components such as a liquid medium and an alkali-developable polymer are added and dispersed in the resin-treated pigment. In addition, you may add another pigment dispersant as needed.

  The method for dispersing the pigment may be any conventionally known method, and is not particularly limited. Specific examples of the apparatus used for dispersing the pigment include vertical and horizontal media mills, sand mills, attritors, microfluidizers, ultrasonic dispersers, and three rolls. It is preferable to use these devices to disperse the pigment until a predetermined number average particle diameter is obtained.

  A pigment dispersant (phosphate group-containing block copolymer) can also be used when the pigment is refined. Specifically, the phosphoric acid group-containing block copolymer is added during the kneading of the pigment, the phosphoric acid group of the phosphoric acid group-containing block copolymer is ionically bonded to the pigment by kneading, and the pigment dispersant is adsorbed to the pigment. The method for kneading the pigment is not particularly limited. Specifically, a conventionally known kneader such as a kneader, an extruder, a ball mill, a two-roll, a three-roll, or a flasher is used, and it is usually 0.5 to 60 hours at room temperature or under heating conditions, preferably 1 to Knead for 12 hours. If necessary, it is preferable to use a salt such as a carbonate or a chloride salt in combination as a medium for refining the pigment. The amount of salt used is preferably 1 to 30 times by mass, more preferably 2 to 20 times by mass with respect to the pigment.

  Further, it is preferable to use a viscous organic solvent such as glycerin, ethylene glycol, diethylene glycol or the like to impart lubricity. Since the phosphoric acid group-containing block copolymer is dissolved in an organic solvent having these viscosities, the pigment can be made fine without precipitation of the phosphoric acid group-containing block copolymer. What is necessary is just to adjust the usage-amount of the organic solvent which has viscosity according to the viscosity of a kneaded material. The resin-treated pigment thus obtained may be used as a water paste after desalting, or may be pulverized into a powder. The obtained resin-treated pigment can be dispersed in a liquid medium to form a pigment dispersion.

  The pigment colorant composition of the present invention can be used as a colorant for various articles. For example, the pigment colorant composition of the present invention can be used as gravure ink, offset ink, UV inkjet ink, and the like. In particular, it is suitable as a colorant for a color filter (a pigment colorant composition for a color filter) because it can reduce viscosity and increase the fineness of the pigment and has good long-term storage stability.

  Next, the present invention will be described in more detail with reference to examples. Hereinafter, “part” and “%” in the text are based on mass unless otherwise specified.

(Synthesis Example 1: PP-1)
In a 1 L separable flask equipped with a reflux tube, a gas introduction device, a thermometer, and a stirring device, 230 parts of propylene glycol monomethyl ether acetate (hereinafter referred to as “PGMAc”), 4.1 parts of iodine, 2,2′− 19.7 parts of azobis (4-methoxy-2,4-dimethylvaleronitrile) (hereinafter referred to as “V-70”), 57.6 parts of methyl methacrylate (hereinafter referred to as “MMA”), butyl methacrylate (Hereinafter referred to as “BMA”) 57.6 parts, 2-ethylhexyl methacrylate (hereinafter referred to as “EHMA”) 28.8 parts, methoxypolyethylene glycol methacrylate (n = 3 to 5) (hereinafter referred to as “PME200”) 28.8 parts, benzyl methacrylate (hereinafter referred to as “BzMA”) 14.4 parts, methacrylic acid (hereinafter referred to as “MAA”) ) 20 parts and 0.9 parts of 3,5-di-t-butyl-4-hydroxytoluene (hereinafter referred to as “BHT”). Polymerization was carried out at 40 ° C. for 7 hours while flowing nitrogen to obtain a solution of A polymer block. The polymerization rate of the A polymer block calculated from the solid content was 87.2%. Moreover, Mn measured by GPC was 4,800, PDI was 1.25, and the molecular weight of the peak top was 6,000. Furthermore, the acid value was 61.7 mgKOH / g.

  12. MMA 26.0 parts, 2- (methacryloyloxy) ethyl phosphate (trade name “Light Ester P-1M”, manufactured by Kyoeisha Chemical Co., Ltd., hereinafter referred to as “P1M”) A mixed solution of 4 parts, 0.9 part of V-70, and 39 parts of PGMAc was added. Polymerization was conducted for 4 hours to form a B polymer block. After stopping the flow of nitrogen, the mixture was heated to 80 ° C. to release iodine bonded to the end of the polymer chain to obtain a polymer solution containing an AB block copolymer. It was confirmed that iodine was liberated when the polymer solution became a brown transparent liquid.

  The obtained polymer solution had a solid content of 48.3%. Further, the polymerization rate of the B polymer block calculated from the solid content was almost 100%. The AB block copolymer had an Mn of 5,500, a PDI of 1.35, a peak top molecular weight of 7,400, and an acid value of 80.5 mgKOH / g. Further, Mn of B polymer block (“Mn of AB block copolymer” − “Mn of A polymer block”) was 700. The resulting AB block copolymer is referred to as “PP-1.”

(Synthesis Example 2: PP-2)
280 parts PGMac, 3.6 parts iodine, 17.7 parts V-70, 77.7 parts MMA, 77.7 parts BMA, 38.8 parts EHMA, 38.8 parts PME200, 19.4 parts BzMA, 27.0 parts MAA, A polymer block solution was obtained in the same manner as in Synthesis Example 1 except that 0.9 part of BHT and 0.9 part of BHT were used. The polymerization rate of the A polymer block calculated from the solid content was 90.1%. The A polymer block had Mn of 7,000, PDI of 1.36, a peak top molecular weight of 9,500, and an acid value of 62.2 mgKOH / g.

  Next, a B polymer block was formed in the same manner as in Synthesis Example 1 except that a mixed solution of 23.1 parts of MMA, 12.0 parts of P1M, 0.8 part of V-70, and 35 parts of PGMAc was used. As a result, a polymer solution containing the AB block copolymer was obtained. The solid content of the obtained polymer solution was 48.5%, and the polymerization rate of the B polymer block calculated from the solid content was almost 100%. The AB block copolymer had an Mn of 7,500, a PDI of 1.40, a peak top molecular weight of 10,500, and an acid value of 76.3 mgKOH / g. The Mn of the B polymer block was 500. The resulting AB block copolymer is referred to as “PP-2”.

(Synthesis Example 3: PP-3)
280 parts PGMac, 3.6 parts iodine, 17.7 parts V-70, 77.7 parts MMA, 77.7 parts BMA, 38.8 parts EHMA, 38.8 parts PME200, 19.4 parts BzMA, 27.0 parts MAA, A polymer block solution was obtained in the same manner as in Synthesis Example 1 except that 0.9 part of BHT and 0.9 part of BHT were used. The polymerization rate of the A polymer block calculated from the solid content was 90.4%. The A polymer block had a Mn of 7,000, a PDI of 1.36, a peak top molecular weight of 9,500, and an acid value of 62.0 mgKOH / g.

  Next, a B polymer block was prepared in the same manner as in Synthesis Example 1 except that a mixed solution of 28.9 parts of MMA, 18.0 parts of P1M, 0.9 part of V-70, and 46.9 parts of PGMAc was used. And a polymer solution containing an AB block copolymer was obtained. The solid content of the obtained polymer solution was 48.8%, and the polymerization rate of the B polymer block calculated from the solid content was almost 100%. The AB block copolymer had an Mn of 8,500, a PDI of 1.44, a peak top molecular weight of 11,200, and an acid value of 82.9 mgKOH / g. The Mn of the B polymer block was 1,500. The resulting AB block copolymer is referred to as “PP-3”.

(Synthesis Example 4: PP-4)
280 parts PGMac, 3.6 parts iodine, 17.7 parts V-70, 77.7 parts MMA, 77.7 parts BMA, 38.8 parts EHMA, 38.8 parts PME200, 19.4 parts BzMA, 27.0 parts MAA, A polymer block solution was obtained in the same manner as in Synthesis Example 1 except that 0.9 part of BHT and 0.9 part of BHT were used. The polymerization rate of the A polymer block calculated from the solid content was 90.9%. The A polymer block had Mn of 6,900, PDI of 1.34, a peak top molecular weight of 9,500, and an acid value of 61.9 mgKOH / g.

  Next, a B polymer block was prepared in the same manner as in Synthesis Example 1 except that a mixed solution of MMA 34.7 parts, P1M 24.0 parts, V-70 1.2 parts, and PGMAc 58.7 parts was used. And a polymer solution containing an AB block copolymer was obtained. The solid content of the obtained polymer solution was 48.6%, and the polymerization rate of the B polymer block calculated from the solid content was almost 100%. The AB block copolymer had an Mn of 9,600, a PDI of 1.45, a peak top molecular weight of 14,000, and an acid value of 89.9 mgKOH / g. The Mn of the B polymer block was 2,700. The resulting AB block copolymer is referred to as “PP-4”.

(Synthesis Example 5: PP-5)
280 parts PGMac, 3.6 parts iodine, 17.7 parts V-70, 77.7 parts MMA, 77.7 parts BMA, 38.8 parts EHMA, 38.8 parts PME200, 19.4 parts BzMA, and 0.9 parts BHT A polymer block solution was obtained in the same manner as in Synthesis Example 1 except that was used. The polymerization rate of the A polymer block calculated from the solid content was 88.5%. The A polymer block had Mn of 6,500, PDI of 1.33, and a peak top molecular weight of 8,600.

  Next, a B polymer block was formed in the same manner as in Synthesis Example 1 except that a mixed solution of 23.1 parts of MMA, 12.0 parts of P1M, 0.8 part of V-70, and 35 parts of PGMAc was used. As a result, a polymer solution containing the AB block copolymer was obtained. The solid content of the obtained polymer solution was 48.4%, and the polymerization rate of the B polymer block calculated from the solid content was almost 100%. The AB block copolymer had an Mn of 7,000, a PDI of 1.40, a peak top molecular weight of 9,800, and an acid value of 22.1 mgKOH / g. The Mn of the B polymer block was 500. The resulting AB block copolymer is referred to as “PP-5”.

(Comparative Synthesis Example 1: HG-1)
300 parts of PGMAc was put into a 1 L separable flask equipped with a reflux tube, a thermometer, and a stirrer, and heated to 80 ° C. MMA 95 parts, BMA 74 parts, EHMA 37 parts, PME 200 in which 7.5 parts of 2,2′-azobisisobutyronitrile and 6 parts of lauryl mercaptan as a chain transfer agent were dissolved in a separate container in advance. A monomer solution containing 37 parts, 18 parts of BzMA, 27 parts of MAA, and 12 parts of P1M was dropped into the 1 L separable flask over 1.5 hours. After completion of the dropwise addition, polymerization was further performed at the same temperature for 5 hours to obtain a polymer solution containing a polymer. The resulting polymer solution had a solid content of 50.3%. The polymer had a Mn of 6,300, a PDI of 1.92, and an acid value of 79.5 mgKOH / g. The resulting polymer is referred to as “HG-1”.

(Comparative Synthesis Example 2: HG-2)
154 parts PGMac, 3.6 parts iodine, 17.7 parts V-70, 42.3 parts MMA, 42.3 parts BMA, 21.3 parts EHMA, 21.3 parts PME200, 12 parts BzMA, 15 parts MAA, and BHT 0.9 A polymer block solution was obtained in the same manner as in Synthesis Example 1 except that the part was used. The polymerization rate of the A polymer block calculated from the solid content was 93.2%. In addition, Mn of the A polymer block was 4,500, PDI was 1.26, peak top molecular weight was 5,700, and acid value was 59.2 mgKOH / g.

  Next, a mixed solution of 67.5 parts of MMA, 11.9 parts of 2-methacryloyloxyethylphthalic acid (hereinafter referred to as “MEPA”), 1.6 parts of V-70, and 79.4 parts of PGMAc was used. Except for the above, a B polymer block was formed in the same manner as in Synthesis Example 1 to obtain a polymer solution containing an AB block copolymer. The solid content of the obtained polymer solution was 48.3%, and the polymerization rate of the B polymer block calculated from the solid content was almost 100%. The AB block copolymer had an Mn of 7,300, a PDI of 1.45, a peak top molecular weight of 12,000, and an acid value of 52.1 mgKOH / g. Further, Mn of B polymer block was 2,800. The resulting AB block copolymer is referred to as “HG-2”.

  The compositions and physical properties of the polymers obtained in the above synthesis examples are shown in Tables 1 to 3.

(Examples 1-6, Comparative Examples 1 and 2: Pigment Colorant Composition)
(A) Pigment Refinement Treatment PR254, PG58, PY138, PY150, PB15-6, and PV23 were prepared as pigments for color filters, and the refinement treatment was performed by the following method. 100 parts of pigment, 400 parts of sodium chloride, and 130 parts of diethylene glycol were charged into a kneader equipped with a pressure lid. Premixed until a uniformly wet mass was formed in the kneader. The pressure lid was closed and kneaded and ground for 7 hours while pressing the contents at a pressure of 6 kg / cm ² to obtain a ground product. The obtained ground product was added to 3,000 parts of 2% sulfuric acid and stirred for 1 hour. After removing sodium chloride and diethylene glycol by filtration, the product was sufficiently washed with water, and then dried and ground to obtain a pigment powder. The number average particle size of the obtained pigment powder was about 30 nm.

(B) Preparation of pigment colorant composition Each component shown in Table 4 was blended in the amount (parts) shown in Table 4 and stirred with a dissolver for 2 hours. After confirming that the lump of the pigment had disappeared, the pigment colorant composition (pigment dispersion) was prepared by performing dispersion treatment using a horizontal media disperser. In Table 4, “Synergist 1” is the following structural formula (1) (n = 1 to 2 (substantially 1.5)), “Synergist 2” is the following structural formula (2), and “Synergist 3”. Are pigment derivatives each having an amino group, each represented by the following structural formula (3) (n = 1 to 2 (substantially 1.5)). In addition, “acrylic resin” in Table 4 has a monomer composition of BzMA / MAA = 80/20 (mass ratio), Mn by GPC measurement of 5,500, and PDI of 2.02 (PGMAc solution ( Solid content concentration: 30%)) was used.

(Evaluation of pigment colorant composition (1))
Measurement results of the number average particle diameter of the pigment contained in the obtained pigment colorant composition (pigment dispersion), initial viscosity of the pigment dispersion, and viscosity after standing at 45 ° C. for 3 days (viscosity after storage) Table 5 shows the measurement results.

  As shown in Table 5, the number average particle diameters of the pigments contained in the pigment colorant compositions (pigment dispersions) of Examples 1 to 6 are all 50 nm or less, and the refined pigment is sufficiently fine. Turned out to be distributed. In addition, all of the pigment dispersions of Examples 1 to 6 had an initial viscosity of 10 mPa · s or less. Moreover, when the initial viscosity and the viscosity after storage are compared, it can be seen that the change in viscosity is extremely small. From the above, it is clear that the pigment dispersions of Examples 1 to 6 have sufficient dispersion stability.

  On the other hand, when compared with the pigment dispersion liquid of Example 1, the pigment dispersion liquid of Comparative Example 1 has a large number average particle diameter of the pigment and is not sufficiently finely dispersed. Furthermore, since the viscosity after storage is greatly increased, it can be seen that the dispersion stability is also insufficient. Further, since the pigment dispersion of Comparative Example 2 does not contain phosphate group-containing methacrylate as a constituent of the polymer block of B, the adsorptive power to the pigment is weak and the viscosity at the initial stage of dispersion is good. It was found that pigment aggregation occurred and the dispersion stability was insufficient.

(Examples 7 to 9: Pigment colorant composition for color filter)
The components shown in Table 6 were blended in the amounts (parts) shown in Table 6 and sufficiently mixed with a mixer to obtain a color filter pigment colorant composition (pigment ink) for each color as a color resist. The “photosensitive acrylic resin varnish” in Table 6 is a varnish containing an acrylic resin obtained by reacting glycidyl methacrylate with a BzMA / MAA copolymer. This acrylic resin had Mn of 6,000, PDI of 2.38, and an acid value of 110 mgKOH / g. “TMPTA” represents trimethylolpropane triacrylate, “HEMPA” represents 2-hydroxyethyl-2-methylpropionic acid, and “DEAP” represents 2,2-diethoxyacetophenone.

A glass substrate treated with a silane coupling agent was set on a spin coater. The red pigment ink-1 of Example 7 was spin-coated on a glass substrate at 300 rpm for 5 seconds. After pre-baking at 80 ° C. for 10 minutes, exposure was performed using an ultrahigh pressure mercury lamp at a light amount of 100 mJ / cm ² to produce a red glass substrate. Further, a green glass substrate and a blue glass were produced in the same manner as in the case of producing the red glass substrate except that the green pigment ink-1 of Example 8 and the blue pigment ink-1 of Example 9 were used. A substrate was manufactured.

  Each of the obtained glass substrates (color glass substrates) of each color had excellent spectral curve characteristics and excellent fastness such as light resistance and heat resistance. In addition, all the color glass substrates were excellent in optical properties such as light transmittance and contrast ratio.

(Comparative Examples 3 and 4: Pigment colorant composition for color filter)
(I) Instead of “PP-2”, a polyester-based dispersant having no phosphoric acid group (condensate of polyε-caprolactone and polyethyleneimine, starting with 12-hydroxystearic acid, Mn: 12, 000, amine value: 12 mg KOH / g), and (ii) in the same manner as in Example 1 except that monosulfonated diketopyrrolopyrrole was used instead of “synergist 1”. A red pigment dispersion was prepared. In addition, (i) the above-described polyester-based dispersant was used instead of “PP-4”, and (ii) monosulfonated copper phthalocyanine was used instead of “synergist 3”. A comparative blue pigment dispersion was prepared in the same manner as in Example 5.

  A red pigment ink (Comparative Example 3) and a blue pigment ink (Comparative Example 4) are prepared in the same manner as in Example 7 except that these prepared comparative pigment dispersions are used. At the same time, a red glass substrate and a blue glass substrate for comparison were manufactured.

(Alkali developability test)
A 0.1N tetramethylammonium hydroxide aqueous solution was spotted on each of the color glass substrates produced using the pigment inks of Examples 7 to 9 and Comparative Examples 3 and 4 every 5 seconds. Then, “after how many seconds the exposed part of the coating film dissolves” was confirmed by visual observation. The results are shown in Table 7.

  As shown in Table 7, all of the glass substrates manufactured using the red pigment ink-1 of Example 7, the green pigment ink-1 of Example 8, and the blue pigment ink-1 of Example 9 are all short-time. As a result, the exposed portion of the coating film was dissolved and no dissolution residue (film-like residue) was produced, and good developability was exhibited. In addition, when the edge part (edge) of the coating film which remained without melt | dissolving was observed with the microscope, it has confirmed that all were sharp. That is, if the pigment colorant compositions (pigment inks) of Examples 7 to 9 are used, the development time can be shortened, and thus an improvement in productivity is expected.

  On the other hand, in the glass substrate manufactured using the manufactured red pigment ink of Comparative Example 3 and the blue pigment ink of Comparative Example 4, it took 60 seconds or more to completely eliminate the exposed portion of the coating film. . The long development time is considered to be due to the use of a pigment dispersant that is not suitable for alkaline development. Moreover, about any glass substrate, the exposed part of the coating film was detached in the form of a film, and a residue was generated. This is presumably because the pigment dispersant is not alkali-soluble. From the above, it was found that the coating films formed using the pigment inks of Examples 7 to 9 using the pigment dispersants of Examples 1, 2, and 5 were excellent in alkali developability.

(Reference Examples 1-3: Preparation of resin-treated pigment powder)
100 parts of PR254 (pigment), 400 parts of sodium chloride, and 130 parts of diethylene glycol were charged into a kneader equipped with a pressure lid. Premixed until a uniformly wet mass was formed in the kneader. Next, 61.5 parts of “PP-2” was added, the pressure lid was closed, and the mixture was kneaded and ground for 7 hours while pressing the contents at a pressure of 6 kg / cm ² to obtain a ground product. The obtained ground product was added to 3,000 parts of 2% sulfuric acid and stirred for 1 hour. After removing sodium chloride and diethylene glycol by filtration, the product was sufficiently washed with water, then dried and pulverized to obtain a red pigment powder (Reference Example 1). The number average particle diameter of the obtained pigment powder was 30 nm.

  A green pigment powder (Reference Example 2) was obtained in the same manner as in Reference Example 1 except that PR254 was replaced with PG58, and “PP-2” was replaced with “PP-1”. The number average particle diameter of the obtained pigment powder was 35 nm. A blue pigment powder (Reference Example 3) was prepared in the same manner as in Reference Example 1 except that PR254 was replaced with PB15: 6 and “PP-2” was replaced with “PP-4”. Obtained. The number average particle diameter of the obtained pigment powder was 30 nm.

(Examples 10 to 12: pigment colorant composition)
Each component shown in Table 8 was blended in the amount (parts) shown in Table 8 and stirred with a dissolver for 2 hours. After confirming that the lump of the pigment had disappeared, the pigment colorant composition (pigment dispersion) was prepared by performing dispersion treatment using a horizontal media disperser.

(Evaluation of pigment colorant composition (2))
Measurement results of the number average particle diameter of the pigment contained in the obtained pigment colorant composition (pigment dispersion), initial viscosity of the pigment dispersion, and viscosity after standing at 45 ° C. for 3 days (viscosity after storage) Table 9 shows the measurement results.

  As shown in Table 9, the pigment colorant compositions (pigment dispersions) of Examples 10 to 12 had good initial and post-storage viscosities. From the above, it was confirmed that the pigment dispersant of the present invention can exhibit sufficient pigment dispersibility even when added and used when the pigment is refined.

(Examples 13 to 15: Pigment colorant composition for color filter)
The components shown in Table 10 were blended in the amounts (parts) shown in Table 10 and sufficiently mixed with a mixer to obtain a color filter pigment colorant composition (pigment ink) for each color as a color resist.

A glass substrate treated with a silane coupling agent was set on a spin coater. The red pigment ink-2 of Example 13 was spin-coated on a glass substrate at 300 rpm for 5 seconds. After pre-baking at 80 ° C. for 10 minutes, exposure was performed using an ultrahigh pressure mercury lamp at a light amount of 100 mJ / cm ² to produce a red glass substrate. Further, a green glass substrate and a blue glass were produced in the same manner as in the case of producing the red glass substrate except that the green pigment ink-2 of Example 14 and the blue pigment ink-2 of Example 15 were used. A substrate was manufactured.

  Since the obtained glass substrates (color glass substrates) for each color are not subjected to hue adjustment, they cannot be said to be reliable filter hues. However, all of the color glass substrates have excellent spectral curve characteristics and excellent fastness such as light resistance and heat resistance. In addition, all the color glass substrates were excellent in optical properties such as light transmittance and contrast ratio.

  The phosphate group-containing block copolymer of the present invention has particularly excellent properties as a pigment dispersant. For this reason, if the phosphate group-containing block copolymer of the present invention is used, a pigment colorant composition having a low viscosity and excellent long-term storage stability can be prepared. And since this pigment colorant composition (pigment ink) is excellent in coating properties and developability, a color filter excellent in optical properties such as fineness, color density, light transmission, and contrast is manufactured. It is useful as a material for In addition, the pixel display device including the color filter manufactured in this way is excellent in image performance such as definition, color density, light transmission, and contrast.

Claims (13)

It is an AB block type copolymer comprising an A polymer block and a B polymer block, containing 90% by mass or more of a structural unit derived from a methacrylic acid monomer,
Of the A polymer block and the B polymer block, only the B polymer block contains a structural unit derived from a phosphoric acid group-containing methacrylic acid monomer having a phosphoric acid group. . The A polymer block includes a structural unit derived from a carboxyl group-containing methacrylic acid monomer having a carboxyl group,
The phosphate group-containing block copolymer according to claim 1, wherein the acid value of the A polymer block is 10 to 200 mgKOH / g.   The phosphate group-containing block copolymer according to claim 2, wherein the carboxyl group-containing methacrylic monomer is methacrylic acid. The number average molecular weight of the A polymer block is 3,000 to 20,000, and the molecular weight distribution (weight average molecular weight / number average molecular weight) is 1.6 or less,
The number average molecular weight of the B polymer block is 200 to 3,000,
The number average molecular weight is 4,000 to 23,000, and the molecular weight distribution (weight average molecular weight / number average molecular weight) is 1.6 or less. The phosphoric acid according to any one of claims 1 to 3. Group-containing block copolymer. The acid value of the B polymer block is 50 to 500 mgKOH / g,
The phosphate group-containing block copolymer according to any one of claims 1 to 4, wherein the content of the B polymer block is 5 to 40% by mass. A method for producing a phosphate group-containing block copolymer according to any one of claims 1 to 5,
Including the step of living radical polymerization of the monomer component containing the methacrylic acid monomer in the presence of a polymerization initiating compound and a catalyst,
The method for producing a phosphate group-containing block copolymer, wherein the polymerization initiating compound is at least one of iodine and an iodine compound.   The catalyst is at least one compound selected from the group consisting of phosphorus halides, phosphite compounds, phosphinate compounds, imide compounds, phenol compounds, diphenylmethane compounds, and cyclopentadiene compounds. 6. A process for producing a phosphate group-containing block copolymer according to 6.   The method for producing a phosphate group-containing block copolymer according to claim 6 or 7, wherein the living radical polymerization is carried out at a polymerization temperature of 30 to 50 ° C.   A pigment dispersant comprising the phosphate group-containing block copolymer according to any one of claims 1 to 5 as a main component.   A pigment colorant composition comprising the pigment dispersant according to claim 9 and a pigment having a number average particle diameter of 10 to 150 nm.   The pigment colorant composition according to claim 10, further comprising a pigment derivative having a basic functional group. The content of the phosphate group-containing block copolymer with respect to 100 parts by mass of the pigment is 10 to 100 parts by mass,
The pigment colorant composition according to claim 11, wherein the content of the dye derivative is 5 to 100 parts by mass with respect to 100 parts by mass of the pigment.   The pigment colorant composition according to any one of claims 10 to 12, which is used as a colorant for a color filter.