JP2017019937A - Block copolymer, dispersant and pigment dispersion composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a block copolymer capable of adding excellent dispersion property, storage stability of a dispersant, alkali developability and dry remelting property when used as the dispersant for example.SOLUTION: A block copolymer comprises a block A containing a structural unit represented by the following general formula (1) and a block B containing a structural unit derived from a vinyl monomer having a tertiary amino group and a structural unit derived from a vinyl monomer having a quaternary ammonium salt group, and has amine value of 20 to 150 mgKOH/g. In the formula (1), n is an integer of 1 to 10, Ris a hydrogen atom or a methyl group, Ris an alkylene group having 1 to 10 carbon atoms and Ris an alkylene group having 1 to 10 carbon atoms.SELECTED DRAWING: None

Description

  The present invention relates to a block copolymer, a dispersant, and a pigment dispersion composition.

  Conventionally, a pigment dispersion method, a dyeing method, an electrodeposition method, a printing method, and the like are known as methods for producing a color filter used for a liquid crystal display or the like. Among these, the pigment dispersion method is widely used from the viewpoints of spectral characteristics, durability, pattern shape, and accuracy. In the pigment dispersion method, for example, a coating film made of a pigment dispersion composition in which a pigment, a dispersant, and a solvent are mixed is formed on a substrate, exposed through a photomask having a desired pattern shape, and alkali developed (for example, (See Patent Document 1).

  When the alkali developability of the coating film formed from the pigment dispersion composition is poor, a development residue may occur, and the chromaticity, contrast, dimensional accuracy, etc. of the color filter may decrease.

  In addition, in the step of applying the pigment dispersion composition, the pigment dispersion composition may adhere to a coating apparatus or the like, and may be dried to form a precipitate. If the solubility of the precipitate in the solvent is low, the precipitate may be mixed into the coating film, which may hinder image formation.

  Therefore, in Patent Document 2, when used as a dispersant, excellent dispersibility, solubility of a coating film formed from the dispersion composition in an alkaline aqueous solution (hereinafter referred to as “alkali developability”), and from the dispersion composition Contains a block containing a lactone-modified (meth) acrylate and an amino group-containing (meth) acrylate that can provide solubility of the dried precipitate formed in the solvent (hereinafter referred to as “dry re-dissolvability”). Block copolymers having blocks have been proposed.

JP 2009-52010 A JP 2013-119568 A

  In recent years, pigment particles have been made finer due to the increasing contrast of color filters. Therefore, the copolymer of Patent Document 2 sometimes has insufficient storage stability of the pigment dispersion.

  The present invention mainly provides a block copolymer that can give excellent dispersibility, storage stability of the dispersion, alkali developability and dry redissolvability when used as a dispersant, for example. Objective.

  As a result of intensive studies to solve the above problems, the present inventors have completed the present invention. That is, the gist of the present invention is as follows.

  Item 1 A block containing a structural unit represented by the following general formula (1), a structural unit derived from a vinyl monomer having a tertiary amino group, and a structural unit derived from a vinyl monomer having a quaternary ammonium base A block copolymer having an amine value of 20 to 150 mgKOH / g.

[In General formula (1), n is an integer of 1-10. R ¹ is a hydrogen atom or a methyl group. R ² is an alkylene group having 1 to 10 carbon atoms. R ³ is an alkylene group having 1 to 10 carbon atoms. ]

  Item 2. The block copolymer according to Item 1, wherein the structural unit derived from the vinyl monomer having a tertiary amino group is represented by the following general formula (2).

[In General Formula (2), R ⁴ represents a hydrogen atom or a methyl group. R ⁵ is an alkylene group having 1 to 10 carbon atoms. R ⁶ and R ⁷ are each independently an alkyl group having 1 to 10 carbon atoms which may have a substituent. ]

  Item 3. The block copolymer according to Item 1 or 2, wherein the structural unit derived from the vinyl monomer having a quaternary ammonium base is represented by the following general formula (3).

[In General Formula (3), R ⁸ represents a hydrogen atom or a methyl group. R ⁹ is an alkylene group having 1 to 10 carbon atoms. R ¹⁰ , R ¹¹ and R ¹² are each independently an alkyl group having 1 to 10 carbon atoms which may have a substituent. Z ⁻ represents a counter ion. ]

  Item 4: The ratio of the molar equivalent number of the quaternary ammonium base to the total molar equivalent number of the tertiary amino group and the quaternary ammonium base is 5 to 85 mol%, The block copolymer as described.

  Item 5 The block copolymer according to any one of Items 1 to 4, wherein the content of the A block is 50 to 95% by mass in 100% by mass of the entire block copolymer.

  Item 6. The block copolymer according to any one of Items 1 to 5, which is a diblock copolymer comprising the A block and the B block.

  Item 7. The block copolymer according to any one of Items 1 to 6, wherein the block copolymer is polymerized by a living radical polymerization method.

  Item 8. A dispersant containing the block copolymer according to any one of Items 1 to 7.

  Item 9 A pigment dispersion composition comprising the dispersant according to item 8, a pigment and a dispersion medium.

  Item 10. The pigment dispersion composition according to Item 9, which is for a color filter.

  According to the present invention, for example, when used as a dispersant, a block copolymer having excellent dispersibility, storage stability of the dispersion, alkali developability and dry redissolvability can be provided.

  Hereinafter, an example of the preferable form which implemented this invention is demonstrated. However, the following embodiment is merely an example. The present invention is not limited to the following embodiments.

<Block copolymer>
The block copolymer of the present invention is a copolymer polymerized using two or more kinds of vinyl monomers. Specifically, an A block containing a structural unit represented by the general formula (1) described later, a structural unit derived from a vinyl monomer having a tertiary amino group, and a structural unit derived from a vinyl monomer having a quaternary ammonium base. And an amine value of 20 to 150 mgKOH / g. The A block can also be referred to as “A segment”, and the B block as “B segment”.

  In the present invention, “vinyl monomer” means a monomer having a carbon-carbon double bond capable of radical polymerization in the molecule, and “structural unit derived from vinyl monomer” means carbon capable of radical polymerization of vinyl monomer. -A structural unit in which a carbon double bond is a carbon-carbon single bond. “(Meth) acryl” means “at least one of acrylic and methacrylic”, “(meth) acrylic acid” means “at least one of acrylic acid and methacrylic acid”, and “(meth) acryloyl” means “acryloyl”. And at least one of methacryloyl ".

  Various components of the block copolymer of the present invention will be described below.

(Block A)
The A block is a polymer block including a structural unit represented by the following general formula (1).

[In General formula (1), n is an integer of 1-10. R ¹ is a hydrogen atom or a methyl group. R ² is an alkylene group having 1 to 10 carbon atoms. R ³ is an alkylene group having 1 to 10 carbon atoms. ]

  N in the general formula (1) is preferably an integer of 1 to 7, and more preferably an integer of 1 to 5.

Specific examples of the alkylene group having 1 to 10 carbon atoms represented by R ² include a methylene group, an ethylene group, a trimethylene group, a tetramethylene group, a pentamethylene group, a hexamethylene group, and a heptamethylene group. R ² is preferably an alkylene group having 1 to 5 carbon atoms.

Specific examples of the alkylene group having 1 to 10 carbon atoms represented by R ³ include a methylene group, an ethylene group, a trimethylene group, a tetramethylene group, a pentamethylene group, a hexamethylene group, and a heptamethylene group. R ³ is preferably an alkylene group having 1 to 8 carbon atoms, and more preferably an alkylene group having 3 to 8 carbon atoms.

  Specific examples of the vinyl monomer forming the structural unit represented by the general formula (1) include 1 mol of caprolactone of 2-hydroxyethyl (meth) acrylate and 2 mol of caprolactone of 2-hydroxyethyl (meth) acrylate. , Caprolactone 3 mol adduct of 2-hydroxyethyl (meth) acrylate, caprolactone 4 mol adduct of 2-hydroxyethyl (meth) acrylate, caprolactone 5 mol adduct of 2-hydroxyethyl (meth) acrylate, and the like.

  The A block may be only the structural unit represented by the above general formula (1), or may contain other structural units. The content of the structural unit represented by the general formula (1) is preferably 10 to 100% by mass, more preferably 20 to 80% by mass in 100% by mass of the entire A block, and 40 to 60% by mass. % Is more preferable.

  Other structural units that can be included in the A block are formed by vinyl monomers that can be copolymerized with both the vinyl monomer that forms the structural unit represented by the general formula (1) and the vinyl monomer that forms the B block described below. There is no particular limitation as long as it is. Specific examples of vinyl monomers that can form other structural units of the A block include aromatic unsaturated monomers (styrene monomers), (meth) acrylic acid esters, and the like. Examples of the aromatic unsaturated monomer include styrene and α-methylstyrene. As (meth) acrylic acid ester, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, octyl (meth) acrylate , 2-ethylhexyl (meth) acrylate, glycidyl (meth) acrylate, benzyl (meth) acrylate, hydroxyethyl (meth) acrylate, polyethylene glycol (meth) acrylate, polypropylene glycol (meth) acrylate and the like.

  The other structural unit that can be contained in the A block is preferably a structural unit represented by the following general formula (4).

[Wherein, R ¹³ represents a hydrogen atom or a methyl group. R ¹⁴ is an alkyl group having 1 to 10 carbon atoms that may have a substituent. ]

Specific examples of the alkyl group having 1 to 10 carbon atoms represented by R ¹⁴ include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, and tert-butyl group. , A linear or branched alkyl group such as a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group and a decyl group. R ¹⁴ is preferably an alkyl group having 1 to 5 carbon atoms which may have a substituent. When the alkyl group having 1 to 10 carbon atoms represented by R ¹⁴ has a substituent, examples of the substituent include an aryl group. Carbon number of an aryl group is 6-12 normally, and it is preferable that it is 6-9. Specific examples of the aryl group include phenyl group, tolyl group, xylyl group, mesityl group, naphthyl group and the like. The position of the substituent is not particularly limited. The number of substituents is usually 1 to 3, and is preferably 1.

  In addition, the A block may have a structural unit having an acidic group, but when the ratio increases, the affinity with the solvent and the alkali-soluble resin may be reduced. Therefore, the ratio of the structural unit having an acidic group is preferably set so that the total acid value of the block copolymer is lower than the amine value, and the total acid value of the block copolymer is less than 25 mgKOH / g. The ratio is more preferable. Specific examples of the monomer that can form a structural unit having an acidic group include (meth) acrylic acid.

  The A block preferably does not contain a structural unit derived from a vinyl monomer having an amino group and a structural unit derived from a vinyl monomer having a quaternary ammonium base. When the A block includes a structural unit derived from a vinyl monomer having an amino group and a structural unit derived from a vinyl monomer having a quaternary ammonium base, the structural unit derived from a vinyl monomer having an amino group in the A block and a quaternary The content of the vinyl monomer having an ammonium base is preferably 1% by mass or less in 100% by mass of the entire A block.

  1 type (s) or 2 or more types can be used for the vinyl monomer used by A block. The structural unit of the A block may be contained in any form such as random copolymer or block copolymer. For example, the A block may be formed of a copolymer of a structural unit composed of an A ′ block and a structural unit composed of an A ″ block.

(B block)
The B block is a polymer block including a structural unit derived from a vinyl monomer having a tertiary amino group and a structural unit derived from a vinyl monomer having a quaternary ammonium base.

  Although there is no restriction | limiting in particular as a structural unit derived from the vinyl monomer which has a tertiary amino group, For example, the structural unit represented by following General formula (2) is mentioned.

[In General Formula (2), R ⁴ represents a hydrogen atom or a methyl group. R ⁵ is an alkylene group having 1 to 10 carbon atoms. R ⁶ and R ⁷ are each independently an alkyl group having 1 to 10 carbon atoms which may have a substituent. ]

Specific examples of the alkylene group having 1 to 10 carbon atoms represented by R ⁵ include alkylene groups such as a methylene group, an ethylene group, a trimethylene group, a tetramethylene group, a pentamethylene group, a hexamethylene group, and a heptamethylene group. Can be mentioned. R ⁵ is preferably an alkylene group having 1 to 5 carbon atoms.

Specific examples of the alkyl group having 1 to 10 carbon atoms represented by R ⁶ and R ⁷ include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, Examples thereof include linear or branched alkyl groups such as a tert-butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, and a decyl group. R ⁶ and R ⁷ are preferably each independently an alkyl group having 1 to 5 carbon atoms. When the alkyl group having 1 to 10 carbon atoms represented by R ⁶ and R ⁷ has a substituent, examples of the substituent include an aryl group. The aryl group usually has 6 to 12 carbon atoms, and preferably includes a phenyl group, a tolyl group, a xylyl group, a mesityl group, a naphthyl group, and the like. The position of the substituent is not particularly limited. The number of substituents is usually 1 to 3, and is preferably 1.

  Specific examples of the vinyl monomer forming the structural unit represented by the general formula (2) include dimethylaminoethyl (meth) acrylate, dimethylaminopropyl (meth) acrylate, dimethylaminobutyl (meth) acrylate, diethylaminoethyl (meth) ) Acrylate, diethylaminopropyl (meth) acrylate, diethylaminobutyl (meth) acrylate and the like.

  Although there is no restriction | limiting in particular as a structural unit derived from the vinyl monomer which has a quaternary ammonium base, For example, the structural unit represented by following General formula (3) is mentioned.

[In General Formula (3), R ⁸ represents a hydrogen atom or a methyl group. R ⁹ is an alkylene group having 1 to 10 carbon atoms. R ¹⁰ , R ¹¹ and R ¹² are each independently an alkyl group having 1 to 10 carbon atoms which may have a substituent. Z ⁻ represents a counter ion. ]

Specific examples of the alkylene group having 1 to 10 carbon atoms represented by R ⁹ include alkylene groups such as a methylene group, an ethylene group, a trimethylene group, a tetramethylene group, a pentamethylene group, a hexamethylene group, and a heptamethylene group. Can be mentioned. R ⁹ is preferably an alkylene group having 1 to 5 carbon atoms.

Specific examples of the alkyl group having 1 to 10 carbon atoms represented by R ¹⁰ , R ¹¹ and R ¹² include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec- Examples thereof include linear or branched alkyl groups such as butyl group, tert-butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group and decyl group. R ¹⁰ , R ¹¹ and R ¹² are preferably each independently an alkyl group having 1 to 5 carbon atoms. When the alkyl group having 1 to 10 carbon atoms represented by R ¹⁰ , R ¹¹ and R ¹² has a substituent, examples of the substituent include an aryl group. Carbon number of an aryl group is 6-12 normally, and it is preferable that it is 6-9. Specific examples of the aryl group include phenyl group, tolyl group, xylyl group, mesityl group, naphthyl group and the like. The position of the substituent is not particularly limited. The number of substituents is usually 1 to 3, and is preferably 1.

Examples of Z ⁻ include halide ions, alkyl carboxylate ions, nitroxide ions, alkyl sulfate ions, sulfonate ions, phosphate ions, and alkyl phosphate ions.

  Specific examples of the monomer that can form the structural unit represented by the general formula (3) include (meth) acryloyloxyethyltrimethylammonium chloride, (meth) acryloyloxypropyltrimethylammonium chloride, and (meth) acryloyloxybutyltrimethylammonium. Chloride, (meth) acryloyloxyethylbenzyldimethylammonium chloride, (meth) acryloyloxypropylbenzyldimethylammonium chloride, (meth) acryloyloxybutylbenzyldimethylammonium chloride, (meth) acryloyloxyethylbenzyldiethylammonium chloride, (meth) acryloyl Oxypropylbenzyldiethylammonium chloride, (meth) acryloyloxybutylbenzyldiethyla Monium chloride, (meth) acryloyloxyethyltrimethylammonium bromide, (meth) acryloyloxypropyltrimethylammonium bromide, (meth) acryloyloxybutyltrimethylammonium bromide, (meth) acryloyloxyethylbenzyldimethylammonium bromide, (meth) acryloyloxypropyl Benzyldimethylammonium bromide, (meth) acryloyloxybutylbenzyldimethylammonium bromide, (meth) acryloyloxyethylbenzyldiethylammonium bromide, (meth) acryloyloxypropylbenzyldiethylammonium bromide, (meth) acryloyloxybutylbenzyldiethylammonium bromide, ( (Meta) acryloyloxye Trimethylammonium iodide, (meth) acryloyloxypropyltrimethylammonium iodide, (meth) acryloyloxybutyltrimethylammonium iodide, (meth) acryloyloxyethylbenzyldimethylammonium iodide, (meth) acryloyloxypropylbenzyldimethylammonium iodide (Meth) acryloyloxybutylbenzyldimethylammonium iodide, (meth) acryloyloxyethylbenzyldiethylammonium iodide, (meth) acryloyloxypropylbenzyldiethylammonium iodide, (meth) acryloyloxybutylbenzyldiethylammonium iodide, (Meth) acryloyloxyethyltrimethylammonium fluoride, (meth) acrylic Royloxypropyltrimethylammonium fluoride, (meth) acryloyloxybutyltrimethylammonium fluoride, (meth) acryloyloxyethylbenzyldimethylammonium fluoride, (meth) acryloyloxypropylbenzyldimethylammonium fluoride, (meth) acryloyloxybutylbenzyl Examples thereof include dimethylammonium fluoride, (meth) acryloyloxyethylbenzyldiethylammonium fluoride, (meth) acryloyloxypropylbenzyldiethylammonium fluoride, and (meth) acryloyloxybutylbenzyldiethylammonium fluoride.

  The B block may be only the structural units represented by the general formula (2) and the general formula (3) described above, or may include other structural units. The content of the structural unit represented by the general formula (2) and the general formula (3) is preferably 80 to 100% by mass and more preferably 90 to 100% by mass in 100% by mass of the entire B block. preferable.

  A structural unit derived from a vinyl monomer having a quaternary ammonium base is obtained by polymerizing a vinyl monomer having a quaternary ammonium base or polymerizing a vinyl monomer having a tertiary amino group, and then a part of the tertiary amino group. Can be obtained by quaternizing.

  The ratio (mol%) of the number of molar equivalents of the quaternary ammonium base to the total number of molar equivalents of the tertiary amino group and quaternary ammonium base contained in the copolymer varies depending on the type of pigment to be dispersed. It is preferably 85 mol%, more preferably 5 to 60 mol%, still more preferably 5 to 15 mol%. When the ratio (mol%) is low, the adsorptivity to the pigment surface may not be sufficient, and when the ratio (mol%) is high, the dry re-dissolvability and alkali developability may be reduced. In addition, when obtaining the structural unit derived from the vinyl monomer which has a quaternary ammonium base by quaternizing a part of tertiary amino group, the said ratio (mol%) is what is called "quaternization rate." To do.

  Other structural units that can be included in the B block are copolymerized with both the vinyl monomer that forms the structural unit represented by the general formula (2) and the general formula (3), and the vinyl monomer that forms the A block. There is no particular limitation as long as it is formed of a vinyl monomer that can be used. Specific examples of vinyl monomers that can form other structural units of the B block include aromatic unsaturated monomers (styrene monomers), (meth) acrylic acid esters, and the like. Examples of the aromatic unsaturated monomer include styrene and α-methylstyrene. As (meth) acrylic acid ester, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, octyl (meth) acrylate , 2-ethylhexyl (meth) acrylate, glycidyl (meth) acrylate, benzyl (meth) acrylate, hydroxyethyl (meth) acrylate, polyethylene glycol (meth) acrylate, polypropylene glycol (meth) acrylate and the like.

  1 type (s) or 2 or more types can be used for the vinyl monomer used by B block. The structural unit of the B block may be contained in any form such as random copolymer or block copolymer. For example, the B block may be formed of a copolymer of a structural unit composed of a B ′ block and a structural unit composed of a B ″ block.

(Block copolymer)
The amine value of the block copolymer is 20 to 150 mgKOH / g. It is preferable that the B block contains a structural unit derived from a vinyl monomer having a tertiary amino group so that the amine value of the block copolymer falls within this range. The lower limit of the amine value of the block copolymer is preferably 30 mgKOH / g, and more preferably 40 mgKOH / g. The upper limit of the amine value of the block copolymer is preferably 120 mgKOH / g, and more preferably 100 mgKOH / g.

  The content of the A block is preferably 50 to 95% by mass, more preferably 55 to 80% by mass, and further preferably 60 to 70% by mass in 100% by mass of the entire block copolymer. preferable.

  The content of the B block is preferably 5 to 50% by mass, more preferably 20 to 45% by mass, and further 30 to 40% by mass in 100% by mass of the entire block copolymer. preferable.

  The lower limit of the weight average molecular weight (Mw) of the block copolymer is preferably 3,000, more preferably 5,000. The upper limit of the weight average molecular weight (Mw) of the block copolymer is preferably 40,000, and more preferably 30,000.

  The block copolymer preferably has a molecular weight distribution (PDI) of 1.05 to 2.20, more preferably 1.05 to 2.00. In the present invention, the molecular weight distribution (PDI) is determined by (weight average molecular weight (Mw) of block copolymer) / (number average molecular weight (Mn) of block copolymer).

  In the present invention, when obtaining a structural unit derived from a vinyl monomer having a quaternary ammonium base by quaternizing a part of a tertiary amino group, Mw, Mn and PDI are quaternary unless otherwise specified. Mw, Mn and PDI before conversion are considered.

  Since the A block of the block copolymer has an ester bond moiety and a terminal hydroxyl group in the side chain of the structural unit represented by the general formula (1), it is considered to have high affinity with the solvent and the binder resin. On the other hand, since the B block has a quaternary ammonium base in addition to a tertiary amino group in the side chain, it is considered to have a high affinity for the pigment. The block copolymer has a partial structure represented by the general formula (1) contained in the A block, a structural unit derived from a vinyl monomer having a tertiary amino group contained in the B block, and a quaternary ammonium base. Structural units derived from vinyl monomers are localized. Therefore, in the solvent, the side chain of the partial structure represented by the general formula (1) constituting the A block preferably interacts with the solvent and the binder resin, and independently, the tertiary amino constituting the B block. Since the group and the quaternary ammonium base can preferably interact with the pigment, the block copolymer is excellent in all of the dispersibility of the pigment, the storage stability of the dispersion, the dry redissolvability and the alkali developability. . Therefore, the block copolymer can be suitably used as a dispersant such as a pigment.

(Method for producing block copolymer)
The method for producing the block copolymer of the present invention is not particularly limited, and examples thereof include a block polymerization method such as a living radical polymerization method. The block copolymer of the present invention can be obtained by sequentially polymerizing monomers constituting the block by the block polymerization method.

  According to the method for producing a block copolymer of the present invention, the A block may be produced first by a polymerization reaction of vinyl monomers, and the vinyl monomer of the B block may be polymerized into the A block; The B block may be polymerized with the monomer of the A block; alternatively, the A block and the B block may be coupled after the A block and the B block are separately produced by the polymerization reaction of the vinyl monomer. For example, as a method for producing the block copolymer of the present invention, a step of polymerizing a monomer constituting one block of the A block and the B block by a living radical polymerization method, and polymerizing one block; After polymerizing one block, the manufacturing method provided with the process of superposing | polymerizing the vinyl monomer which comprises the other block of A block and B block, and superposing | polymerizing the other block is mentioned.

  Also, by polymerizing A block and B block vinyl monomers other than the vinyl monomer having a quaternary ammonium base by the above-described production method, and then quaternizing a part of the tertiary amino group by a known method. The block copolymer of the present invention can also be produced. It is also possible to produce the block copolymer of the present invention by polymerizing the vinyl monomers of the A block and the B block after first quaternizing a part of the vinyl monomer having a tertiary ammonium base. As quaternizing agents, alkyl halides such as methyl chloride, ethyl chloride, methyl bromide, methyl iodide, benzyl chloride, benzyl bromide, benzyl iodide, dimethyl sulfate, diethyl sulfate, di-n-propyl sulfate, etc. The alkylating agent can be mentioned. As for the alkyl group derived from the quaternizing agent, the alkyl group introduced by the quaternization can be estimated from the reaction amount of the quaternizing agent used for the quaternization.

  The living radical polymerization method is a polymerization method that enables precise control of the molecular structure while maintaining the simplicity and versatility of radical polymerization. The living radical polymerization method includes a method using a transition metal catalyst (ATRP method), a method using a sulfur-based reversible chain transfer agent (RAFT method), and an organic tellurium compound depending on the method for stabilizing the polymerization growth terminal. There are methods such as a method to be used (TERP method). Since the ATRP method uses an amine-based complex, it may not be used without protecting the acidic group of the vinyl monomer having an acidic group. In the RAFT method, when various monomers are used, it is difficult to obtain a low molecular weight distribution, and there may be a problem such as sulfur odor or coloring. Among these methods, the TERP method is preferably used from the viewpoints of diversity of usable monomers, molecular weight control in the polymer region, and coloring.

  The TERP method is a method of polymerizing a radical polymerizable compound using an organic tellurium compound as a polymerization initiator, and is a method described in, for example, International Publication Nos. 2004/14848 and 2004/14962.

  Specifically, a polymerization method using the following (a) to (d) is exemplified.

(A) an organic tellurium compound represented by the general formula (5),
(B) a mixture of an organic tellurium compound represented by the general formula (5) and an azo polymerization initiator,
(C) a mixture of an organic tellurium compound represented by the general formula (5) and an organic ditellurium compound represented by the general formula (6), or (d) an organic tellurium compound represented by the general formula (5), an azo type A mixture of a polymerization initiator and an organic ditellurium compound represented by the general formula (6);
Polymerization is carried out using any of the above.

[In Formula (5), R < ¹³ > shows a C1-C8 alkyl group, an aryl group, or an aromatic heterocyclic group. R ¹⁴ and R ¹⁵ each represent a hydrogen atom or an alkyl group having 1 to 8 carbon atoms. R ¹⁶ represents an alkyl group having 1 to 8 carbon atoms, an aryl group, an aromatic heterocyclic group, an acyl group, an amide group, an oxycarbonyl group, or a cyano group. ]

(R ¹³ Te) ₂ (6)

[In Formula (6), R < ¹³ > shows a C1-C8 alkyl group, an aryl group, or an aromatic heterocyclic group. ]

  Specific examples of the organic tellurium compound represented by the general formula (5) include (methylterranylmethyl) benzene, (methylterranylmethyl) naphthalene, ethyl-2-methyl-2-methylterranyl-propionate, and ethyl-2-methyl. 2-n-butyl terranyl-propionate, (2-trimethylsiloxyethyl) -2-methyl-2-methyl terranyl-propionate, (2-hydroxyethyl) -2-methyl-2-methyl terranyl-propionate, (3-trimethylsilylpropargyl) Examples include 2-methyl-2-methylterranyl-propinate.

  Specific examples of the compound represented by the general formula (6) include dimethyl ditelluride, diethyl ditelluride, di-n-propyl ditelluride, diisopropyl ditelluride, dicyclopropyl ditelluride, di-n. -Butyl ditelluride, di-s-butyl ditelluride, di-t-butyl ditelluride, dicyclobutyl ditelluride, diphenyl ditelluride, bis- (p-methoxyphenyl) ditelluride, bis- (p-aminophenyl) ditelluride, bis- ( Examples thereof include p-nitrophenyl) ditelluride, bis- (p-cyanophenyl) ditelluride, bis- (p-sulfonylphenyl) ditelluride, dinaphthylditelluride, dipyridylditelluride and the like.

  The azo polymerization initiator can be used without particular limitation as long as it is an azo polymerization initiator used in normal radical polymerization. For example, 2,2′-azobis (isobutyronitrile) (AIBN), 2,2′-azobis (2-methylbutyronitrile) (AMBN), 2,2′-azobis (2,4-dimethylvaleronitrile) (ADVN), 1,1′-azobis (1-cyclohexanecarbonitrile) (ACHN), dimethyl-2,2′-azobisisobutyrate (MAIB), 4,4′-azobis (4-cyanovaleric acid) (ACVA), 1,1′-azobis (1-acetoxy-1-phenylethane), 2,2′-azobis (2-methylbutyramide), 2,2′-azobis (4-methoxy-2,4- Dimethylvaleronitrile) (V-70), 2,2′-azobis (2-methylamidinopropane) dihydrochloride, 2,2′-azobis [2- (2-imidazolin-2-yl) propyl Pan], 2,2′-azobis [2-methyl-N- (2-hydroxyethyl) propionamide], 2,2′-azobis (2,4,4-trimethylpentane), 2-cyano-2-propyl Examples include azoformamide, 2,2′-azobis (N-butyl-2-methylpropionamide), 2,2′-azobis (N-cyclohexyl-2-methylpropionamide), and the like.

  The amount of the compound of the general formula (5) may be appropriately adjusted depending on the physical properties of the target polymer, but the compound of the general formula (5) is usually 0.05 to 50 mmol per 1 mol of the monomer. .

  When the compound of the general formula (5) and the azo polymerization initiator are used in combination, it is usually preferable to use 0.01 to 10 mol of the azo polymerization initiator with respect to 1 mol of the compound of the general formula (5).

  When the compound of the general formula (5) and the compound of the general formula (6) are used in combination, the compound of the general formula (6) is usually used in an amount of 0.01 to 100 mol with respect to 1 mol of the compound of the general formula (5). .

  When the compound of the general formula (5), the compound of the general formula (6) and the azo polymerization initiator are used in combination, the azo compound is usually added to 1 mol in total of the compound of the general formula (5) and the compound of the general formula (6). The polymerization initiator is preferably 0.01 to 100 mol.

  The polymerization reaction can be carried out without a solvent, but may be carried out by stirring the above mixture using an organic solvent or an aqueous solvent generally used in radical polymerization. Usable organic solvents are, for example, benzene, toluene, N, N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), acetone, 2-butanone (methyl ethyl ketone), dioxane, hexafluoroisopropaol, propylene glycol monomethyl ether acetate. , Chloroform, carbon tetrachloride, tetrahydrofuran (THF), ethyl acetate, trifluoromethylbenzene and the like. Examples of the aqueous solvent include water, methanol, ethanol, isopropanol, n-butanol, ethyl cellosolve, butyl cellosolve, 1-methoxy-2-propanol, diacetone alcohol and the like.

  The reaction temperature and reaction time may be appropriately adjusted depending on the molecular weight or molecular weight distribution of the polymer to be obtained, but are usually stirred at 0 to 150 ° C. for 1 minute to 100 hours. The TERP method can obtain a high yield and a precise molecular weight distribution even at a low polymerization temperature and a short polymerization time.

  After completion of the polymerization reaction, the target polymer can be separated from the obtained reaction mixture by a usual separation and purification means.

<Pigment dispersion composition>
The pigment dispersion composition according to the present embodiment includes a dispersant containing the block copolymer, a pigment, and a dispersion medium. The pigment dispersion composition may contain a binder resin or the like.

  In the pigment dispersion composition, the content of the dispersant is preferably 5 parts by mass to 200 parts by mass, more preferably 10 parts by mass to 100 parts by mass with respect to 100 parts by mass of the pigment, and 10 parts by mass. More preferably, it is -50 mass parts.

  The pigment may be either an organic pigment or an inorganic pigment, but an organic pigment containing an organic compound as a main component is particularly preferable. Examples of the pigment include pigments of various colors such as a red pigment, a yellow pigment, an orange pigment, a blue pigment, a green pigment, and a purple pigment. The structure of the pigment is azo pigments such as monoazo pigments, diazo pigments, condensed diazo pigments, diketopyrrolopyrrole pigments, phthalocyanine pigments, isoindolinone pigments, isoindoline pigments, quinacridone pigments, indigo Examples thereof include polycyclic pigments such as pigments, thioindigo pigments, quinophthalone pigments, dioxazine pigments, anthraquinone pigments, perylene pigments, and perinone pigments. Only one type of pigment may be contained in the pigment dispersion composition, or a plurality of types may be used. Specific examples of the pigment include C.I. I. Pigment Red 7, 9, 14, 41, 48: 1, 48: 2, 48: 3, 48: 4, 81: 1, 81: 2, 81: 3, 122, 123, 146, 149, 168, 177, Red pigments such as 178, 179, 187, 200, 202, 208, 210, 215, 224, 254, 255, 264; I. Pigment Yellow 1, 3, 5, 6, 14, 55, 60, 61, 62, 63, 65, 73, 74, 77, 81, 93, 97, 98, 104, 108, 110, 138, 139, 147, Yellow pigments such as 150, 151, 154, 155, 166, 167, 168, 170, 180, 188, 193, 194, 213; I. Orange pigments such as CI Pigment Orange 36, 38, 43; I. Pigment Blue 15, 15: 2, 15: 3, 15: 4, 15: 6, 16, 22, 60 and the like; C.I. I. Green pigments such as Pigment Green 7, 36, 58; I. And violet pigments such as Pigment Violet 23, 32, and 50. Among these pigments, C.I. I. Pigment Red 254, C.I. I. Pigment Red 255, C.I. I. Pigment Red 264, C.I. I. Pigment Blue 15, C.I. I. Pigment Blue 15: 2, C.I. I. Pigment Blue 15: 3, C.I. I. Pigment Blue 15: 4, C.I. I. Pigment Blue 15: 6, C.I. I. Pigment Blue 16, C.I. I. Pigment Green 7, C.I. I. Pigment Green 36, C.I. I. Pigment Green 58 and the like are preferable.

  The upper limit of the pigment content in the pigment dispersion composition is usually 80% by mass, preferably 70% by mass, and more preferably 60% by mass in the total solid content of the pigment dispersion composition. . Further, the lower limit of the pigment content in the pigment dispersion composition is usually 10% by mass, preferably 20% by mass, and preferably 30% by mass in the total solid content of the pigment dispersion composition. More preferred.

  The binder resin may be a polymer, for example. When the binder resin is a polymer, specific examples of monomers constituting the polymer include, for example, carboxyl groups such as (meth) acrylic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, crotonic acid, and maleic anhydride Containing unsaturated monomer: methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, octyl (meth) acrylate, lauryl (meth) acrylate, (meth) (Meth) acrylic such as 2-hydroxyethyl acrylate, benzyl (meth) acrylate, cyclohexyl (meth) acrylate, methyl cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, cyclododecyl (meth) acrylate Acid ester; styrene, α-methylstyrene, 4-methylstyrene ( -Methylstyrene), 2-methylstyrene (o-methylstyrene), 3-methylstyrene (m-methylstyrene), 4-methoxystyrene (p-methoxystyrene), p-tert-butylstyrene, pn-butyl Examples thereof include aromatic unsaturated monomers (styrene monomers) such as styrene and p-tert-butoxystyrene. The binder resin is preferably a copolymer of a carboxyl group-containing unsaturated monomer and a (meth) acrylic acid ester. Specific examples of such a copolymer include a copolymer of (meth) acrylic acid and butyl (meth) acrylate, a copolymer of (meth) acrylic acid and benzyl (meth) acrylate, And a copolymer of acrylic acid, butyl (meth) acrylate, and benzyl (meth) acrylate. From the viewpoint of the affinity between the binder resin and the pigment, the binder resin is particularly preferably a copolymer of (meth) acrylic acid and benzyl (meth) acrylate. In the copolymer of a carboxyl group-containing unsaturated monomer and a (meth) acrylic acid ester, the content of (meth) acrylic acid is usually 5% by mass to 90% by mass, and 10% by mass to all monomer components. It is preferable that it is 70 mass%, and it is more preferable that it is 20 mass%-70 mass%.

  The Mw of the binder resin is preferably 3,000 to 100,000, more preferably 5,000 to 50,000, and still more preferably 5,000 to 20,000. When the Mw of the binder resin is 3,000 or more, the heat resistance, film strength, etc. of the coating film formed from the pigment dispersion composition are good, and when the Mw is 100,000 or less, the aqueous alkaline solution of this coating film Developability due to is further improved.

  The acid value of the binder resin is preferably 20 mgKOH / g to 170 mgKOH / g, more preferably 50 mgKOH / g to 150 mgKOH / g, and still more preferably 90 mgKOH / g to 150 mgKOH / g. When the acid value of the binder resin is 20 mgKOH or more / g, the alkali developability when the pigment dispersion composition is used as a coating film is further improved, and when it is 170 mgKOH / g or less, the heat resistance is improved.

  The binder resin contained in the pigment dispersion composition may be only one type or a plurality of types.

  In the pigment dispersion composition, the content of the binder resin is preferably 5 parts by mass to 200 parts by mass, more preferably 10 parts by mass to 100 parts by mass with respect to 100 parts by mass of the pigment. More preferably, it is 50 parts by mass.

  As the dispersion medium, for example, a conventionally known organic solvent can be used. For example, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol mono Ethyl ether, propylene glycol mono-n-butyl ether, propylene glycol t-butyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol mono-n-butyl ether, methoxymethylpentanol, propylene glycol monoethyl ether, dipropylene glycol monoethyl Ether, dipropylene glycol monomethyl ether Glycol, 3-methyl-3-methoxybutanol, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, tripropylene glycol methyl ether and other glycol monoalkyl ethers; ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, diethylene glycol Glycol dialkyl ethers such as diethyl ether, diethylene glycol dipropyl ether, diethylene glycol dibutyl ether, dipropylene glycol dimethyl ether; ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol mono-n-butyl ether acetate, propylene glycol Monoethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, propylene glycol monobutyl ether acetate, methoxybutyl acetate, 3-methoxybutyl acetate, methoxypentyl acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate Glycol alkyl ether acetates such as diethylene glycol mono-n-butyl ether acetate, dipropylene glycol monomethyl ether acetate, triethylene glycol monomethyl ether acetate, triethylene glycol monoethyl ether acetate, 3-methyl-3-methoxybutyl acetate; Glycol diacetates such as ethylene glycol diacetate, 1,3-butylene glycol diacetate, 1,6-hexanol diacetate; alkyl acetates such as cyclohexanol acetate; amyl ether, propyl ether, diethyl ether, dipropyl ether, Ethers such as diisopropyl ether, butyl ether, diamyl ether, ethyl isobutyl ether, dihexyl ether; acetone, methyl ethyl ketone, methyl amyl ketone, methyl isopropyl ketone, methyl isoamyl ketone, diisopropyl ketone, diisobutyl ketone, methyl isobutyl ketone, cyclohexanone, ethyl amyl Ketone, methyl butyl ketone, methyl hexyl ketone, methyl nonyl ketone, methoxymethyl pentano Ketones such as: ethanol, propanol, butanol, hexanol, cyclohexanol, ethylene glycol, propylene glycol, butanediol, diethylene glycol, dipropylene glycol, triethylene glycol, methoxypropanol, methoxymethylpentanol, glycerin, benzyl alcohol, etc. Monohydric or polyhydric alcohols; aliphatic hydrocarbons such as n-pentane, n-octane, diisobutylene, n-hexane, hexene, isoprene, dipentene, dodecane; fats such as cyclohexane, methylcyclohexane, methylcyclohexene, and bicyclohexyl Cyclic hydrocarbons; aromatic hydrocarbons such as benzene, toluene, xylene, cumene; amyl formate, ethyl formate, ethyl acetate, butyl acetate, Propyl acid, amyl acetate, methyl isobutyrate, ethylene glycol acetate, ethyl propionate, propyl propionate, butyl butyrate, isobutyl butyrate, methyl isobutyrate, ethyl caprylate, butyl stearate, ethyl benzoate, 3-ethoxypropion Linear or cyclic esters such as methyl acid, ethyl 3-ethoxypropionate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, propyl 3-methoxypropionate, butyl 3-methoxypropionate, and γ-butyrolactone; Alkoxy carboxylic acids such as 3-methoxypropionic acid and 3-ethoxypropionic acid; halogenated hydrocarbons such as butyl chloride and amyl chloride; ether ketones such as methoxymethylpentanone; acetonitrile, Nitriles such as Nzonitoriru, and the like. The organic solvent is preferably glycol alkyl ether acetates, monovalent or polyhydric alcohols from the viewpoint of dispersibility of pigments, solubility of dispersants, applicability of pigment dispersion compositions, and the like. The solvent contained in the pigment dispersion composition may be only one type or a plurality of types.

  The content of the dispersion medium in the pigment dispersion composition is not particularly limited and can be appropriately adjusted. The upper limit of the content of the dispersion medium in the pigment dispersion composition is usually 99% by mass. The lower limit of the content of the dispersion medium in the pigment dispersion composition is usually 70% by mass and preferably 80% by mass in consideration of the viscosity suitable for application of the pigment dispersion composition.

  The dispersion medium can be used as a solvent for dissolving and removing precipitates formed from the pigment dispersion composition.

  The pigment dispersion composition is obtained by mixing a pigment, a dispersant, a binder resin, a dispersion medium and the like using a mixing and dispersing machine such as a paint shaker, a bead mill, a ball mill, a dissolver, or a kneader. The pigment dispersion composition is preferably filtered after mixing.

  The pigment dispersion composition may contain other additives as required. Examples of other additives include a photopolymerizable monomer, a photopolymerization initiator, a pigment derivative, a pH adjuster, an antioxidant, an ultraviolet absorber, a light stabilizer, a preservative, and an antifungal agent. The photopolymerizable monomer is preferably a compound having at least two ethylenically unsaturated double bonds that are compatible with the binder resin. Such a compound is preferably a compound having alkali solubility and having one or more acidic groups and two or more ethylenically unsaturated bonds in one molecule, and one or more acidic groups in one molecule. More preferred are compounds having three or more ethylenically unsaturated bonds. Examples of the compound having at least two ethylenically unsaturated double bonds include polyfunctional (meth) acrylates such as bifunctional (meth) acrylate and trifunctional or higher functional (meth) acrylate. Among these, trifunctional or higher functional (meth) acrylates are preferable. As a compound having one or more acidic groups and two or more ethylenically unsaturated bonds in one molecule, an acidic group-containing polyfunctional (meth) acrylate is more preferable, and a trifunctional or higher functional acid group-containing polyfunctionality. (Meth) acrylate is particularly preferred. The acidic group is not particularly limited as long as it can be alkali-developed, and examples thereof include a carboxy group, a sulfonic acid group, and a phosphoric acid group. The acidic group is preferably a carboxy group from the viewpoint of further improving the alkali developability and the handleability of the resin composition.

  Examples of the pigment derivative include a sulfonic acid group, a phthalimidomethyl group, a dialkylaminoalkyl group, a hydroxyl group, and a carboxyl group directly or via an alkyl group, an aryl group, a heterocyclic group, or the like in the skeleton structure of the pigment. Substituted ones are mentioned. By using the pigment and the pigment derivative in combination, the dispersibility and dispersion stability of the pigment can be further improved.

  A coating film of the pigment dispersion composition can be formed on the substrate by applying the pigment dispersion composition onto the substrate by a method such as spin coating, roll coating, or slit coating. After applying the pigment dispersion composition on the substrate, drying (desolvation treatment) or the like may be performed as necessary.

  As described above, the block copolymer has an A block and a B block, and the amine value of the block copolymer is 20 mgKOH / g to 150 mgKOH / g. The pigment dispersion composition containing such a block copolymer is excellent in alkali developability and dry redissolvability.

  When the pigment dispersion composition is used as, for example, a patterning material for a color filter, the pigment dispersion composition is excellent in alkali developability, resulting in a residual development, resulting in a decrease in chromaticity, contrast, and dimensional accuracy of the color filter. Can be suppressed.

  In addition, since the pigment dispersion composition is excellent in dry re-dissolvability, when the pigment dispersion composition adheres to a coating apparatus or the like and is dried to generate a precipitate, the precipitate is quickly dissolved in the solvent. In addition, the precipitate can be easily washed using a solvent or the like. Moreover, even if this precipitate is mixed into the pigment dispersion composition, the precipitate is dissolved in the pigment dispersion composition. Therefore, it can suppress that a deposit interferes with image formation.

  Although the details of the reason why the pigment dispersion composition according to this embodiment is excellent in alkali developability and dry redissolvability are not clear, for example, it can be considered as follows. The pigment dispersion composition according to the present embodiment includes a dispersant containing the block copolymer. In the block copolymer, localized tertiary amino groups and quaternary ammonium bases are strongly adsorbed on the surface of the pigment, so that the agglomeration of the pigment even after the pigment dispersion composition according to this embodiment is dried. It has weak force, has an ester bond part and a terminal hydroxyl group in the side chain of the localized partial structure represented by the general formula (1), interacts with the solvent and binder resin, and is localized Since the glass transition temperature of the A block is relatively low by having an ester bond portion and a terminal hydroxyl group in the side chain of the partial structure represented by the general formula (1), the pigment dispersion composition according to this embodiment Is considered to dissolve quickly in a solvent or aqueous alkali solution even after drying. For the above reasons, it is considered that the pigment dispersion composition is excellent in alkali developability and dry redissolvability.

  The pigment dispersion composition can be suitably used for a color filter.

  Hereinafter, the present invention will be described in more detail based on specific examples. The present invention is not limited to the following examples, and can be implemented with appropriate modifications without departing from the scope of the invention. In addition, the various physical-property measurement in an Example and a comparative example was performed in accordance with the following method.

(Polymerization rate)
¹ H-NMR was measured using NMR (trade name: AVANCE500, manufactured by Bruker BioSpin Corporation), and the polymerization rate was calculated from the peak area ratio of the vinyl group of the monomer and the ester side chain of the polymer.

(Weight average molecular weight (Mw) and molecular weight distribution (PDI))
GPC (trade name: HLC-8320GPC, manufactured by Tosoh Corporation, column: TSKgel α-3000, mobile phase: 10 mM lithium bromide / dimethylformamide solution) and polystyrene (molecular weight 427,000, 190,000, 96, 96) as standard substances were used. 400, 37, 400, 10, 200, 2,630, 440, 92) were used to prepare a calibration curve, and the weight average molecular weight (Mw) and the number average molecular weight (Mn) were measured. From this measured value, molecular weight distribution (PDI = Mw / Mn) was calculated.

(Amine number)
The amine value is expressed by the mass of potassium hydroxide equivalent to the basic component per 1 g of the solid content. The measurement sample was dissolved in tetrahydrofuran, and the obtained solution was neutralized and titrated with a 0.1 M hydrochloric acid / 2-propanol solution using a potentiometric titrator (trade name: GT-06, manufactured by Mitsubishi Chemical Corporation). The amine value (B) was calculated by the following formula using the inflection point of the titration pH curve as the titration end point.

B = 56.11 × Vs × 0.1 × f / w
B: Amine value (mgKOH / g)
Vs: Amount of 0.1 M hydrochloric acid / 2-propanol solution used for titration (mL)
f: titer of 0.1M hydrochloric acid (2-propanol) w: mass (g) of measurement sample (solid content conversion)

(Acid value)
The acid value represents the weight of potassium hydroxide required to neutralize acidic components per gram of solid content. The measurement sample was dissolved in tetrahydrofuran, and the obtained solution was neutralized and titrated with a 0.1 M potassium hydroxide / 2-propanol solution using a potentiometric titrator (trade name: GT-06, manufactured by Mitsubishi Chemical Corporation). Using the inflection point of the titration pH curve as the titration end point, the acid value (A) was calculated by the following formula.

A = 56.11 × Vs × 0.5 × f / w
A: Acid value (mgKOH / g)
Vs: Amount of 0.1 M potassium hydroxide / 2-propanol solution required for titration (mL)
f: 0.1M potassium hydroxide (2-propanol) titer w: measurement sample mass (g) (solid content conversion)

(Dispersion stability)
1 ° 34 ′ × R24 cone immediately after production of the pigment dispersion composition and after standing for 7 days at 40 ° C. using an E-type viscometer (trade name: TVE-22L, manufactured by Toki Sangyo Co., Ltd.) Using a rotor, the viscosity was measured at 25 ° C. and a rotor rotation speed of 60 rpm. The viscosity change was evaluated according to the following criteria.

A: Viscosity change is less than + 20% B: Viscosity change is less than + 200% C: Viscosity change is + 200% or more

(Dry re-dissolvability)
The pigment dispersion composition was applied at a thickness of 2 μm on a 50 mm × 30 mm glass plate whose surface had been cleaned, and dried at 90 ° C. for 10 minutes to form a coating film. Next, the glass plate was immersed in a solvent (propylene glycol monomethyl ether acetate), and the solubility of the coating film in the solvent was observed. The solubility was evaluated according to the following criteria.

A: The coating film is eluted from the glass plate within 5 minutes of immersion.
B: The coating film is eluted from the glass plate within 10 minutes of immersion.
C: The coating film remains on the glass plate after 10 minutes of immersion.

(Alkali developability)
A coating film of the pigment dispersion composition was formed to a thickness of 2 μm on a 50 mm × 30 mm glass plate whose surface had been cleaned, and dried at 90 ° C. for 10 minutes. Next, the glass plate on which the coating film was formed was immersed in a 1% potassium hydroxide aqueous solution, and the solubility of the coating film in a 1% potassium hydroxide aqueous solution (alkali aqueous solution) was observed. The solubility was evaluated according to the following criteria.

A: The coating film is eluted from the glass plate in less than 1 minute of immersion.
B: The coating film is eluted from the glass plate within 3 minutes of immersion.
C: The coating film remains on the glass plate after 3 minutes of immersion.

<Manufacture of copolymer>
(Example 1) Production of copolymer A A 5-mol caprolactone adduct of 2-hydroxyethyl methacrylate (trade name: Plaxel FM5, manufactured by Daicel Chemical Industries, hereinafter "PCL5") was added to a flask equipped with an argon gas introduction tube and a stirrer. 3.18 g, n-butyl methacrylate (trade name: Acryester B, manufactured by Mitsubishi Rayon Co., Ltd., hereinafter referred to as “BMA”), methacrylic acid (trade name: MAA methacrylate, manufactured by Mitsubishi Rayon Co., Ltd.) 0.23 g of “MAA”, 0.0328 g of azobisisobutyronitrile (trade name: AIBN, manufactured by Otsuka Chemical Co., Ltd., hereinafter referred to as “AIBN”), 3.81 g of propylene glycol monomethyl ether acetate (hereinafter referred to as “PMA”) After substituting with argon, ethyl-2-methyl-2-n-butylteranyl-pro 0.30 g of pionate (hereinafter referred to as “BTEE”) and 0.18 g of dibutyl ditelluride (hereinafter referred to as “DBDT”) were added and reacted at 60 ° C. for 12 hours. The polymerization rate was 98%.

  To the obtained solution, 2.28 g of dimethylaminoethyl methacrylate (trade name: GE720 (DAM), manufactured by Mitsubishi Gas Chemical Co., Ltd., hereinafter referred to as “DMAEMA”), AIBN 0.0164 g, and PMA 1.52 g previously substituted with argon were added. The mixed solution was added and reacted at 60 ° C. for 10 hours. The polymerization rate was 95%.

  A mixed solution of 0.37 g of benzyl chloride (hereinafter referred to as “BzCl”) and 1.48 g of PMA previously substituted with argon was added to the obtained solution, and the mixture was reacted at 60 ° C. for 20 hours. NMR confirmed the disappearance of the peak of BzCl.

  After completion of the reaction, 20.0 g of PMA was added to the reaction solution and poured into 384 mL of stirred n-heptane. The precipitated polymer was suction filtered and dried to obtain a copolymer A. The Mw before the introduction of the quaternary ammonium base was 10,300, and the PDI was 1.92. Copolymer A had an amine value of 73 mgKOH / g and an acid value of 21 mgKOH / g. Details of the copolymer A are shown in Table 1.

(Example 2) Production of copolymer B A flask equipped with an argon gas inlet tube and a stirrer was charged with 3.18 g of PCL, 2.31 g of BMA, 0.23 g of MAA, 0.0328 g of AIBN, and 3.81 g of PMA. After argon substitution, BTEE 0.30 g and DBDT 0.18 g were added and reacted at 60 ° C. for 16 hours. The polymerization rate was 99%.

  To the resulting solution, a mixed solution of 2.28 g of DMAEMA, 0.0164 g of AIBN, and 1.52 g of PMA which had been substituted with argon in advance was added and reacted at 60 ° C. for 10 hours. The polymerization rate was 99%.

  To the obtained solution, a mixed solution of 0.18 g of BzCl and 0.72 g of PMA previously substituted with argon was added and reacted at 60 ° C. for 20 hours. NMR confirmed the disappearance of the peak of BzCl.

  After completion of the reaction, 20.0 g of PMA was added to the reaction solution and poured into 384 mL of stirred n-heptane. The precipitated polymer was suction filtered and dried to obtain a copolymer B. The Mw before the introduction of the quaternary ammonium base was 10,300, and the PDI was 1.92. Copolymer B had an amine value of 87 mgKOH / g and an acid value of 21 mgKOH / g. Details of the copolymer B are shown in Table 1.

Example 3 Production of Copolymer C A flask equipped with an argon gas inlet tube and a stirrer was charged with 4.10 g of PCL5, 3.00 g of BMA, 0.30 g of MAA, 0.0328 g of AIBN, and 4.93 g of PMA, After argon substitution, BTEE 0.30 g and DBDT 0.18 g were added and reacted at 60 ° C. for 25 hours. The polymerization rate was 100%.

  To the obtained solution, a mixed solution of 2.90 g of DMAEMA, 0.0164 g of AIBN and 1.93 g of PMA previously substituted with argon was added and reacted at 60 ° C. for 23 hours. The polymerization rate was 97%.

  A mixed solution of 1.87 g of BzCl and 7.48 g of PMA previously substituted with argon was added to the obtained solution, and the mixture was reacted at 60 ° C. for 14 hours. NMR confirmed the disappearance of the peak of BzCl.

  After completion of the reaction, 20.0 g of PMA was added to the reaction solution and poured into 384 mL of stirred n-heptane. The precipitated polymer was suction filtered and dried to obtain a copolymer C. The Mw before the introduction of the quaternary ammonium base was 10,900, and the PDI was 1.93. Copolymer C had an amine value of 22 mgKOH / g and an acid value of 20 mgKOH / g. Details of the copolymer C are shown in Table 2.

(Example 4) Production of copolymer D A flask equipped with an argon gas inlet tube and a stirrer was charged with 4.10 g of PCL5, 3.00 g of BMA, 0.30 g of MAA, 0.0328 g of AIBN, and 4.93 g of PMA, After argon substitution, BTEE 0.30 g and DBDT 0.18 g were added and reacted at 60 ° C. for 19 hours. The polymerization rate was 100%.

  To the obtained solution, a mixed solution of 2.90 g of DMAEMA, 0.0164 g of AIBN and 1.93 g of PMA previously substituted with argon was added and reacted at 60 ° C. for 23 hours. The polymerization rate was 99%.

  A mixed solution of 0.93 g of BzCl and 3.72 g of PMA previously substituted with argon was added to the obtained solution, and the mixture was reacted at 60 ° C. for 10 hours. NMR confirmed the disappearance of the peak of BzCl.

  After completion of the reaction, 20.0 g of PMA was added to the reaction solution and poured into 384 mL of stirred n-heptane. The precipitated polymer was suction filtered and dried to obtain a copolymer D. Before the introduction of the quaternary ammonium base, the Mw was 10,900, the PDI was 1.93, the amine value of the copolymer D was 53 mgKOH / g, and the acid value was 20 mgKOH / g. Details of the copolymer D are shown in Table 2.

(Example 5) Production of copolymer E A flask equipped with an argon gas inlet tube and a stirrer was charged with 4.10 g of PCL5, 3.00 g of BMA, 0.30 g of MAA, 0.0328 g of AIBN, and 4.93 g of PMA, After argon substitution, BTEE 0.30 g and DBDT 0.18 g were added and reacted at 60 ° C. for 12 hours. The polymerization rate was 97%.

  A mixed solution of 2.90 g of DMAEMA, 0.0164 g of AIBN and 1.93 g of PMA, which had been substituted with argon in advance, was added to the resulting solution, and the mixture was reacted at 60 ° C. for 10 hours. The polymerization rate was 96%.

  To the obtained solution, a mixed solution of 0.47 g of BzCl previously substituted with argon and 1.88 g of PMA was added and reacted at 60 ° C. for 10 hours. NMR confirmed the disappearance of the peak of BzCl.

  After completion of the reaction, 20.0 g of PMA was added to the reaction solution and poured into 384 mL of stirred n-heptane. The precipitated polymer was suction filtered and dried to obtain a copolymer E. The Mw before the introduction of the quaternary ammonium base was 10,900, and the PDI was 1.93. Copolymer E had an amine value of 76 mgKOH / g and an acid value of 20 mgKOH / g. Details of the copolymer E are shown in Table 2.

Comparative Example 1 Production of Copolymer F A flask equipped with an argon gas inlet tube and a stirrer was charged with 3.18 g of PCL, 2.31 g of BMA, 0.23 g of MAA, 0.0328 g of AIBN, and 3.81 g of PMA. After argon substitution, BTEE 0.30 g and DBDT 0.18 g were added and reacted at 60 ° C. for 20 hours. The polymerization rate was 99%.

  To the resulting solution, a mixed solution of 2.28 g of DMAEMA, 0.0164 g of AIBN, and 1.52 g of PMA which had been substituted with argon in advance was added and reacted at 60 ° C. for 10 hours. The polymerization rate was 97%.

  After completion of the reaction, 20.0 g of PMA was added to the reaction solution and poured into 384 mL of stirred n-heptane. The precipitated polymer was suction filtered and dried to obtain a copolymer F. The copolymer F had an Mw of 10,300, a PDI of 1.92, an amine value of 97 mgKOH / g, and an acid value of 21 mgKOH / g. Details of the copolymer F are shown in Table 1.

Comparative Example 2 Production of Copolymer G In a flask equipped with an argon gas introduction tube and a stirrer, 0.80 g of triethylene glycol monoethyl ether monomethacrylate (manufactured by POLYSCIENCES), 3.70 g of BMA, methyl methacrylate (Mitsubishi) 2.40 g (manufactured by Rayon Co., Ltd.), 2.20 g of 2-ethylhexyl methacrylate (manufactured by Mitsubishi Rayon Co., Ltd.), 0.0328 g of AIBN, 6.07 g of PMA, and after substitution with argon, 0.30 g of BTEE and 0.18 g of DBDT were added. , Reacted at 60 ° C. for 16 hours. The polymerization rate was 99%.

  A mixed solution of DMAEMA 3.90 g, AIBN 0.0164 g, and PMA 2.60 g previously substituted with argon was added to the obtained solution, and the mixture was reacted at 60 ° C. for 10 hours. The polymerization rate was 97%.

  After completion of the reaction, 30.0 g of PMA was added to the reaction solution and poured into 576 mL of stirred n-heptane. The precipitated polymer was suction filtered and dried to obtain a copolymer G. The copolymer G had a Mw of 14,900, a PDI of 1.46, and an amine value of 110 mgKOH / g. Details of the copolymer G are shown in Table 1.

<Production of pigment dispersion composition>
10 parts by mass of pigment, 3 parts by mass of dispersant, binder resin {polymerized with a mass ratio of benzyl methacrylate / methacrylic acid = 80/20, Mw = 9800, PDI = 1.93, acid value of 127 mgKOH / g, solid The composition was adjusted to 3 parts by weight, 40 parts by weight of PMA solution, 10 parts by weight of methoxypropanol, and 74 parts by weight of PMA and stirred with a planetary ball mill (0.3 mm zirconia beads, 2 hours). The pigment dispersion compositions of Examples 6 to 10 and Comparative Examples 3 to 4 shown in 1-2 were obtained. As the dispersant, the copolymers A to G obtained in Examples 1 to 5 and Comparative Examples 1 and 2 were used. I. Pigment Red 177 (trade name: FASTGEN SuperRed ATY, manufactured by DIC) or C.I. I. Pigment Green 58 (trade name: FASTOGEN Green A110, manufactured by DIC Corporation) was used.

  The resulting pigment dispersion composition was evaluated for dispersion stability, dry redissolvability and alkali developability. The results are shown in Tables 1 and 2.

Claims (10)

A block containing a structural unit represented by the following general formula (1), a structural unit derived from a vinyl monomer having a tertiary amino group and a B block containing a structural unit derived from a vinyl monomer having a quaternary ammonium base A block copolymer having an amine value of 20 to 150 mgKOH / g.

[In General formula (1), n is an integer of 1-10. R ¹ is a hydrogen atom or a methyl group. R ² is an alkylene group having 1 to 10 carbon atoms. R ³ is an alkylene group having 1 to 10 carbon atoms. ] The block copolymer according to claim 1, wherein the structural unit derived from the vinyl monomer having a tertiary amino group is represented by the following general formula (2).

[In General Formula (2), R ⁴ represents a hydrogen atom or a methyl group. R ⁵ is an alkylene group having 1 to 10 carbon atoms. R ⁶ and R ⁷ are each independently an alkyl group having 1 to 10 carbon atoms which may have a substituent. ] The block copolymer according to claim 1 or 2, wherein the structural unit derived from the vinyl monomer having a quaternary ammonium base is represented by the following general formula (3).

[In General Formula (3), R ⁸ represents a hydrogen atom or a methyl group. R ⁹ is an alkylene group having 1 to 10 carbon atoms. R ¹⁰ , R ¹¹ and R ¹² are each independently an alkyl group having 1 to 10 carbon atoms which may have a substituent. Z ⁻ represents a counter ion. ]   The ratio of the molar equivalent number of the quaternary ammonium base to the total molar equivalent number of the tertiary amino group and the quaternary ammonium base is 5 to 85 mol%, according to any one of claims 1 to 3. Block copolymer.   The block copolymer as described in any one of Claims 1-4 whose content of the said A block is 50-95 mass% in 100 mass% of the whole block copolymer.   The block copolymer as described in any one of Claims 1-5 which is a diblock copolymer which consists of the said A block and the said B block.   The block copolymer according to any one of claims 1 to 6, wherein the block copolymer is polymerized by a living radical polymerization method.   The dispersing agent containing the block copolymer as described in any one of Claims 1-7.   A pigment dispersion composition comprising the dispersant according to claim 8, a pigment and a dispersion medium.   The pigment dispersion composition according to claim 9, which is used for a color filter.