KR20230164016A - Block copolymers, dispersants, and coloring compositions - Google Patents

Abstract

[Problem] To provide a block copolymer that can be used as a dispersant for an aqueous composition and has high dispersion performance for colorants.
[Solution] The block copolymer is characterized by having an A block containing a structural unit represented by formula (1) and a B block containing a structural unit represented by formula (3).

[In Formula (1), n1 represents an integer of 2 to 30. R ¹¹ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. R ¹² represents an alkylene group having 1 to 3 carbon atoms. R ¹³ represents a hydrogen atom or a methyl group. In addition, plural R ¹² may be the same or different. In formula (3), R ³¹ , R ³² , R ³³ and R ³⁴ are the same or different and represent a hydrogen atom or an alkyl group of 1 to 10 carbon atoms which may have a substituent. m3 represents an integer from 0 to 4. n3 represents an integer from 1 to 3.]

Description

Block copolymers, dispersants, and coloring compositions

The present invention relates to block copolymers, and particularly to block copolymers that can be used as a dispersant for colorants in coloring compositions.

Recently, from the viewpoint of preventing air pollution, there has been a demand for reducing emissions of volatile organic compounds (VOCs) from factories and businesses. For this reason, conversion to a water-based paint composition is being considered for paint compositions used for painting metal plates constituting car bodies such as automobiles. In addition, coating compositions for automobiles are required not only to have coating film performance such as high durability, acid resistance, car wash resistance, scratch resistance, and chipping resistance, but also to have a finished appearance of the coating film, such as transparency and color development, that is higher than before.

Colorants used in coating compositions generally have hydrophobic surfaces. Additionally, dispersants used in solvent-type coating compositions have low solubility in water and are poor in dispersion stability in an aqueous dispersion medium. In particular, carbon particles such as carbon black used as a black colorant have a small primary particle size and a very large specific surface area, so their cohesive force is very strong. Therefore, there is a problem in that it is difficult to uniformly disperse the carbon particles in an aqueous dispersion medium, and even if they are dispersed, they tend to aggregate. Additionally, carbon particles having conductivity are also used as a conductive additive in compositions for forming aqueous electrodes, but, like coating compositions, they have problems with dispersibility.

Therefore, in coating compositions using carbon black as a black colorant, a technique for improving the dispersibility of carbon black has been proposed. For example, in Patent Document 1, carbon black with a DBP oil supply amount of 150 ml/100 g or less, an average primary particle diameter of 15 nm or less, a specific surface area of 500 m ² /g or less, and a pH in the acidic to neutral range is dissolved in water using a dispersant. A highly black carbon black dispersion in which fine particles are dispersed in a medium (sometimes referred to as jet black among color development properties, especially when the colorant is a black colorant) is described. In this Patent Document 1, the dispersibility of carbon black is improved by controlling the physical properties of carbon black (see Patent Document 1 (Claim 1, paragraphs 0019, 0021, 0024)).

Additionally, Patent Document 2 discloses (A) (a) a polymerizable unsaturated monomer having a specific cationic functional group, (b) a polymerizable unsaturated monomer having a polyoxyalkylene chain, and (c) other polymerizable unsaturated monomers. An aqueous coating composition containing a copolymer, (B) a pigment, and (C) an acrylic resin containing an acid group and a hydroxyl group is described (see Patent Document 1 (Claim 1, Paragraph 0014)).

On the other hand, regarding jet blackness, since carbon black is black with a reddish tint, a method of increasing jet blackness by adding a blue colorant (blueing agent) such as a phthalocyanine pigment is known.

Japanese Patent Publication No. 2008-285632 Japanese Patent Publication No. 2014-5399

In water-based paint compositions using carbon particles as black colorants, paint compositions with improved dispersibility of carbon particles have been proposed, but there is room for improvement in preventing agglomeration of carbon particles. In addition, there is also a demand for improvement in the dispersibility of blue colorants (particularly phthalocyanine pigments) using the same dispersant.

The present invention has been made in consideration of the above circumstances, and is a block copolymer that can be used as a dispersant for water-based compositions such as water-based paint compositions and compositions for forming water-based electrodes, and has a dispersion performance of colorants (especially carbon particles and blue colorants). The aim is to provide a high block copolymer. In addition, as a further problem, when used as a dispersant for a coloring composition containing carbon particles, the jet blackness of the coating film can be improved, and when used as a dispersing agent for a coloring composition containing a blue colorant, the transparency and saturation of the coating film can be improved. The purpose is to provide a block copolymer that can be improved.

The block copolymer of the present invention, which was able to solve the above problems, is characterized by having an A block containing a structural unit represented by formula (1) and a B block containing a structural unit represented by formula (3). .

[In Formula (1), n1 represents an integer of 2 to 30. R ¹¹ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. R ¹² represents an alkylene group having 1 to 3 carbon atoms. R ¹³ represents a hydrogen atom or a methyl group. In addition, plural R ¹² may be the same or different.]

[In formula (3), R ³¹ , R ³² , R ³³ and R ³⁴ are the same or different and represent a hydrogen atom or an alkyl group of 1 to 10 carbon atoms which may have a substituent. m3 represents an integer from 0 to 4. n3 represents an integer from 1 to 3.]

In the block copolymer of the present invention, the structural unit represented by formula (1) contained in the A block has high affinity with an aqueous dispersion medium, and the structural unit represented by formula (3) contained in the B block is a colorant. adsorbed to Therefore, the block copolymer can improve the dispersibility of the colorant by using it as a dispersant for the colorant in an aqueous coloring composition containing an aqueous dispersion medium and a colorant.

The block copolymer of the present invention can be used as a dispersant for aqueous compositions such as aqueous coating compositions and compositions for forming aqueous electrodes, and is particularly excellent in dispersing performance of carbon particles and blue colorants. By using the block copolymer of the present invention as a dispersant for a coloring composition containing carbon particles (black colorant), the jet blackness of the coating film can be improved. Moreover, transparency and saturation of the coating film can be improved by using the block copolymer of the present invention as a dispersant for a coloring composition containing a blue colorant.

In addition, since the block copolymer of the present invention is excellent in dispersibility of both carbon particles and blue colorant, it can be appropriately used in an aqueous coloring composition containing carbon particles (black colorant) and blue colorant (bluing agent). Also, a water-based coloring composition with excellent jet blackness can be obtained.

＜Block copolymer＞

The block copolymer of the present invention is characterized by having an A block containing a structural unit represented by formula (1) and a B block containing a structural unit represented by formula (3).

The block copolymer contains a structural unit in which the A block is represented by formula (1) with high affinity for an aqueous dispersion medium. Additionally, the B block contains a structural unit represented by formula (3), which has a portion that adsorbs to a colorant. By using the block copolymer as a dispersing agent in an aqueous coloring composition containing a coloring material, the dispersibility of the coloring material can be improved.

Hereinafter, an example of a preferred form of carrying out the present invention will be described. However, the following embodiments are mere examples. The present invention is in no way limited to the following embodiments.

In the present invention, “A block” can be replaced with “A segment”, and “B block” can be replaced with “B segment”. In the present invention, “vinyl monomer” refers to a monomer having a carbon-carbon double bond capable of radical polymerization in the molecule. “Structural unit derived from vinyl monomer” refers to a structural unit in which the radically polymerizable carbon-carbon double bond of a vinyl monomer polymerizes to become a carbon-carbon single bond. “(Meth)acrylic” refers to “at least one of acrylic and methacrylic.” “(Meth)acrylate” refers to “at least one of acrylate and methacrylate.” “(meth)acryloyl” refers to “at least one of acryloyl and methacryloyl.”

(A block)

A block is a block containing the structural unit represented by formula (1). The structural unit represented by formula (1) in the A block may be one type or may have two or more types.

[In Formula (1), n1 represents an integer of 2 to 30. R ¹¹ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. R ¹² represents an alkylene group having 1 to 3 carbon atoms. R ¹³ represents a hydrogen atom or a methyl group. In addition, plural R ¹² may be the same or different.]

n1 in formula (1) is 2 or more, preferably 5 or more, and 30 or less, preferably 20 or less, more preferably 15 or less.

The alkyl group having 1 to 3 carbon atoms represented by R ¹¹ may be either linear or branched, but is preferably linear. Specific examples of the alkyl group having 1 to 3 carbon atoms represented by R ¹¹ include methyl group, ethyl group, n-propyl group, and isopropyl group.

The alkylene group having 1 to 3 carbon atoms represented by R ¹² may be either linear or branched, but is preferably linear. Specific examples of the alkylene group having 1 to 3 carbon atoms represented by R ¹² include methylene group, ethylene group, trimethylene group, and propane-1,2-diyl group. R ¹² is preferably an ethylene group or a trimethylene group.

Examples of the monomer constituting the structural unit represented by formula (1) include (meth)acrylate having a polyalkylene glycol structure. Additionally, the polyalkylene glycol portion may be, for example, a mixture of ethylene oxide and propylene oxide. Examples of (meth)acrylates having the polyalkylene glycol structure include polyethylene glycol (degree of polymerization = 2 to 30) methyl ether (meth)acrylate, polyethylene glycol (degree of polymerization = 2 to 30) ethyl ether (meth)acrylate, and polyethylene. (meth)acrylates having a polyethylene glycol structure such as glycol (degree of polymerization = 2 to 30) propyl ether (meth)acrylate; Polypropylene glycol (degree of polymerization = 2 to 30) methyl ether (meth)acrylate, polypropylene glycol (degree of polymerization = 2 to 30) ethyl ether (meth) acrylate, polypropylene glycol (degree of polymerization = 2 to 30) propyl ether (meth) ) (meth)acrylate having a polypropylene glycol structural unit such as acrylate, etc.

The content of the structural unit represented by formula (1) is preferably 20% by mass or more, more preferably 35% by mass or more, further preferably 50% by mass or more, based on 100% by mass of the A block. % or less is preferable, more preferably 90 mass% or less, and even more preferably 80 mass% or less. When the content is 20% by mass or more, the affinity with the aqueous dispersion medium improves, and when it is 95% by mass or less, the affinity with the resin for forming a coating film and the resin for forming an electrode becomes better.

It is preferable that the A block further contains a structural unit represented by formula (2). The structural unit represented by formula (2) in the A block may be one type or may have two or more types. When the A block has a structural unit represented by formula (2), affinity with the resin for forming a coating film and the resin for forming an electrode is further improved.

[In formula (2), R ²¹ represents a chain-shaped or cyclic hydrocarbon group that may have a substituent. R ²² represents a hydrogen atom or a methyl group.]

Examples of the chain-shaped hydrocarbon group represented by R ²¹ include a straight-chain alkyl group and a branched-chain alkyl group. The linear alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 10 carbon atoms, and still more preferably 1 to 5 carbon atoms. Examples of the linear alkyl group include methyl group, ethyl group, n-propyl group, n-butyl group, n-hexyl group, n-octyl group, n-nonyl group, n-decyl group, and n-lauryl group. . The number of carbon atoms of the branched alkyl group is preferably 3 to 20 carbon atoms, more preferably 3 to 10 carbon atoms, and still more preferably 3 to 5 carbon atoms. Examples of the branched alkyl group include isopropyl group, isobutyl group, sec-butyl group, tert-butyl group, 2-ethylhexyl group, neopentyl group, and isooctyl group.

Substituents of the chain hydrocarbon group represented by R ²¹ include a halogen group, an alkoxy group, a benzoyl group (-COC ₆ H ₅ ), and a hydroxy group.

Examples of the cyclic hydrocarbon group represented by R ²¹ include a cyclic alkyl group and an aromatic group, and the cyclic alkyl group and the aromatic group may have a chain portion. The number of carbon atoms in the cyclic alkyl group is preferably 4 to 18 carbon atoms, more preferably 6 to 12 carbon atoms, and even more preferably 6 to 10 carbon atoms. Examples of the cyclic alkyl group include cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, and cyclooctyl group. As for the carbon number of an aromatic group, 6-18 carbon atoms are preferable, 6-12 carbon atoms are more preferable, and 6-8 carbon atoms are still more preferable. Examples of the aromatic group include phenyl group, tolyl group, xylyl group, and mesityl group. Examples of the cyclic alkyl group having a chain moiety and the chain moiety of the aromatic group having a chain moiety include an alkylene group having 1 to 12 carbon atoms, preferably an alkylene group having 1 to 6 carbon atoms, and more preferably an alkylene group having 1 to 3 carbon atoms. I can hear it.

Substituents of the cyclic hydrocarbon group represented by R ²¹ include a halogen group, an alkoxy group, an alkyl chain, and a hydroxy group.

Examples of the vinyl monomer forming the structural unit represented by formula (2) include (meth)acrylate having a chain alkyl group (straight-chain alkyl group or branched-chain alkyl group), (meth)acrylate having a cyclic alkyl group, and (meth)acrylate having a polycyclic structure. Meta)acrylate, (meth)acrylate having an aromatic group, etc. are mentioned. Among these, (meth)acrylates having a chain alkyl group (straight-chain alkyl group or branched-chain alkyl group) and (meth)acrylates having a cyclic alkyl group are preferable.

Examples of (meth)acrylates having the above-mentioned straight-chain alkyl group include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, n-butyl (meth)acrylate, and n-pentyl (meth)acrylate. Acrylate, n-hexyl (meth)acrylate, n-octyl (meth)acrylate, n-nonyl (meth)acrylate, n-decyl (meth)acrylate, n-lauryl (meth)acrylate, n -steallyl (meth)acrylate, etc. can be mentioned.

Examples of the (meth)acrylate having the branched chain alkyl group include isopropyl (meth)acrylate, isobutyl (meth)acrylate, sec-butyl (meth)acrylate, tert-butyl (meth)acrylate, isooctyl ( Meta)acrylate, 2-ethylhexyl (meth)acrylate, isononyl (meth)acrylate, isodecyl (meth)acrylate, etc. are mentioned.

Examples of the cyclic alkyl group include a cyclic alkyl group (for example, a cycloalkyl group) having a monocyclic structure. Specific examples of (meth)acrylate having a cyclic alkyl group in a monocyclic structure include cyclohexyl (meth)acrylate, methylcyclohexyl (meth)acrylate, and cyclododecyl (meth)acrylate.

Examples of the polycyclic structure include cyclic alkyl groups having a bridged ring structure (for example, adamantyl group, norbornyl group, isobornyl group). Specific examples of (meth)acrylates having a polycyclic structure include isobornyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, dicyclopentanyloxyethyl (meth)acrylate, and 2-methyl-2. -Adamantyl (meth)acrylate, 2-ethyl-2-adamantyl (meth)acrylate, etc. are mentioned.

Examples of the aromatic group include an aryl group, and may also have a chain moiety such as an alkylaryl group, aralkyl group, or aryloxyalkyl group. Specific examples of (meth)acrylate having an aromatic group include benzyl (meth)acrylate, phenyl (meth)acrylate, and phenoxyethyl (meth)acrylate.

When containing the structural unit represented by formula (2), its content is preferably 5% by mass or more, more preferably 10% by mass or more, and still more preferably 20% by mass, based on 100% by mass of the A block. or more, preferably 80 mass% or less, more preferably 65 mass% or less, and still more preferably 50 mass% or less. If the content is 5% by mass or more, the affinity with the resin for forming a coating film and the resin for forming an electrode is further improved, and if the content is 80% by mass or less, the affinity with the aqueous dispersion medium becomes better.

The A block may be only the structural unit represented by formula (1), or only the structural unit represented by formula (1) and the structural unit represented by formula (2), or may contain other structural units. The total content of the structural unit represented by formula (1) and the structural unit represented by formula (2) in the A block is preferably 70 mass% or more, more preferably 80 mass% or more, and still more preferably 90 mass%. % or more, particularly preferably 97 mass% or more.

Specific examples of vinyl monomers that can form other structural units of the A block include (meth)acrylate having a hydroxy group, (meth)acrylate having a lactone-modified hydroxy group, (meth)acrylate having an alkoxy group, and (meth)acrylate having an acidic group. Meth)acrylate, (meth)acrylic acid, (meth)acrylate having a cyclic ether group, etc. are mentioned.

Examples of (meth)acrylates having a hydroxy group include 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate. ) Acrylate, 6-hydroxyhexyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, 12-hydroxylauryl (meth)acrylate, etc. I can hear it. Among these, (meth)acrylates having a hydroxyalkyl group having 1 to 5 carbon atoms are more preferable.

Examples of the (meth)acrylate having a lactone-modified hydroxy group include those obtained by adding lactone to the (meth)acrylate having the above-mentioned hydroxy group, and those obtained by adding caprolactone are preferable. The amount of caprolactone added is preferably 1 mol to 20 mol, and more preferably 1 mol to 10 mol. Examples of the (meth)acrylate having the lactone-modified hydroxy group include 1 mol of caprolactone adduct of 2-hydroxyethyl (meth)acrylate, 2 mol of caprolactone adduct of 2-hydroxyethyl (meth)acrylate, and 2-hydroxyethyl (meth)acrylate. Caprolactone 3 mol adduct of oxyethyl (meth)acrylate, caprolactone 4 mol adduct of 2-hydroxyethyl (meth)acrylate, caprolactone 5 mol adduct of 2-hydroxyethyl (meth)acrylate, 2- A 10 mol caprolactone adduct of hydroxyethyl (meth)acrylate, etc. is preferred.

Examples of (meth)acrylates having an alkoxy group include methoxyethyl (meth)acrylate, ethoxyethyl (meth)acrylate, and the like.

As an acidic group, a carboxylic acid group (-COOH), a sulfonic acid group (-SO ₃ H), a phosphoric acid group (-OPO ₃ H ₂ ), a phosphonic acid group (-PO ₃ H ₂ ), and a phosphinic acid group (-PO ₂ H ₂ ). I can hear it. Examples of the (meth)acrylate having the acidic group include (meth)acrylate having a carboxyl group, (meth)acrylate having a phosphoric acid group, and (meth)acrylate having a sulfonic acid group.

Examples of (meth)acrylates having a carboxy group include carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, 2-(meth)acryloyloxyethylsuccinic acid, and 2-(meth)acryloyloxyethylmale. Monomers obtained by reacting acid anhydrides such as maleic anhydride, succinic anhydride, and phthalic anhydride with (meth)acrylates having a hydroxyl group such as acid and 2-(meth)acryloyloxyethylphthalic acid can be mentioned. Examples of (meth)acrylates having a phosphoric acid group include 2-(phosphonooxy)ethyl (meth)acrylate. Examples of (meth)acrylate having a sulfonic acid group include ethyl sulfonic acid (meth)acrylate.

Examples of (meth)acrylates having a cyclic ether group include glycidyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, (meth)acryloylmorpholine, and 2-(4-morpholinyl (meth)acrylate). )ethyl, (3-ethyloxetan-3-yl)methyl(meth)acrylate, (2-methyl-2-ethyl-1,3-dioxolan-4-yl)methyl(meth)acrylate, cyclic trimethyl All-propane formal (meth)acrylate, 2-[(2-tetrahydropyranyl)oxy]ethyl (meth)acrylate, 1,3-dioxane-(meth)acrylate, etc. are mentioned.

The A block has a content of the structural unit represented by (3) above, preferably 3% by mass or less, more preferably 1% by mass or less, and still more preferably 0.1% by mass or less, expressed by formula (3) It is particularly preferred that it does not contain any structural units.

When two or more types of structural units are contained in the A block, the various structural units contained in the A block may be contained in the A block in any form such as random copolymerization or block copolymerization, and from the viewpoint of uniformity, random copolymerization It is preferable that it is contained in the form of. For example, the A block may be formed by a copolymer of a structural unit made of an a1 block and a structural unit made of an a2 block.

(B block)

The B block is a block containing the structural unit represented by formula (3). The structural unit represented by formula (3) in the B block may be one type or may have two or more types.

[In formula (3), R ³¹ , R ³² , R ³³ and R ³⁴ are the same or different and represent a hydrogen atom or an alkyl group of 1 to 10 carbon atoms which may have a substituent. m3 represents an integer from 0 to 4. n3 represents an integer from 1 to 3.]

The number of carbon atoms of the alkyl group in R ³¹ to R ³⁴ is preferably 1 to 6, more preferably 1 to 4. As an alkyl group, methyl group and ethyl group are more preferable, and methyl group is particularly preferable. The substituents for R ³¹ to R ³⁴ are not particularly limited, and include carboxy groups, sulfonic acid groups, esters and salts thereof, amino groups, hydroxy groups, etc.

R ³¹ is preferably a hydrogen atom or a methyl group, and more preferably a hydrogen atom.

R ³² to R ³⁴ are preferably hydrogen atoms.

As m3, it is preferable that it is an integer of 0 to 2, more preferably, it is an integer of 0 to 1, and even more preferably, it is 0.

n3 is preferably 1 or 2, and more preferably 1.

As the structural unit represented by the formula (3), the structural unit represented by the formula (31) is preferable.

[In formula (31), R ³¹ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. m3 represents an integer from 0 to 4. n3 represents an integer from 1 to 3.]

Examples of the vinyl monomer forming the structural unit represented by formula (3) include N-vinylpyrrolidone, N-vinyl-5-methylpyrrolidone, N-vinyl-5-ethylpyrrolidone, and N- Vinyl monomers having a 5-membered ring lactam structure such as vinyl-5-propylpyrrolidone, N-vinyl-5-butylpyrrolidone, and 1-(2-propenyl)-2-pyrrolidone; N-vinylpiperidone Vinyl monomers having a 6-membered ring lactam structure such as; Vinyl monomers having a 7-membered ring lactam structure such as N-vinylcaprolactam, etc. are mentioned. The vinyl monomer forming the structural unit represented by formula (3) can be used singly or in combination of two or more. Among these, vinyl monomers having a 5-membered ring lactam structure are preferable, and N-vinylpyrrolidone is more preferable.

The content of the structural unit represented by formula (3) is preferably 50% by mass or more in 100% by mass of the B block, more preferably 55% by mass or more, further preferably 60% by mass or more, especially preferably is 70 mass% or more, preferably 100 mass% or less, more preferably 95 mass% or less, further preferably 90 mass% or less. If the content is 50% by mass or more, aggregation of the colorant is suppressed, dispersibility is improved, and a coating film excellent in transparency, saturation, or jet blackness can be formed.

The B block may be only the structural unit represented by formula (3), or may contain other structural units.

Specific examples of vinyl monomers capable of forming other structural units of the B block include the same as those exemplified as specific examples of monomers capable of forming other structural units of the A block, as well as vinyl monomers having a basic group. .

The basic group is preferably an amino group because of ease of obtaining raw materials and synthesis. In this specification, the amino group is -NHR ⁴¹ , -NR ⁴¹ R ⁴² (R ⁴¹ and R ⁴² are each independently chain-shaped or cyclic) in which H is substituted with a hydrocarbon group in addition to the structure of a general amino group (-NH ₂ ). It represents a hydrocarbon group. Additionally, R ⁴¹ and R ⁴² may be bonded to each other to form a cyclic structure.) and a nitrogen-containing heterocyclic group (pyridyl group, imidazole group, etc.).

Specific examples of vinyl monomers having a basic group include dimethylaminoethyl (meth)acrylate, dimethylaminopropyl (meth)acrylate, dimethylaminobutyl (meth)acrylate, diethylaminoethyl (meth)acrylate, and diethylaminopropyl. (meth)acrylate, diethylaminobutyl (meth)acrylate, ethylaminoethyl (meth)acrylate, ethylaminopropyl (meth)acrylate, ethylaminobutyl (meth)acrylate, propylaminoethyl (meth)acrylate salt, propylaminopropyl (meth)acrylate, propylaminobutyl (meth)acrylate, dimethylaminopropyl (meth)acrylamide, 4-vinylpyridine, etc.

When the B block contains other structural units, the other structural units include a structural unit derived from (meth)acrylate having a cyclic ether group, a structural unit derived from (meth)acrylate having an aromatic group, and a monocyclic structure. At least one type selected from the group consisting of structural units derived from (meth)acrylates having a cyclic alkyl group is preferable.

Examples of the structural unit derived from (meth)acrylate having a cyclic ether group contained in the B block include the structural unit represented by formula (41).

[In formula (41), A ¹ represents a cyclic ether group that may have a substituent. R ⁴¹ represents a divalent hydrocarbon group. R ⁴² represents a hydrogen atom or a methyl group.]

Examples of the cyclic ether group represented by A ¹ include oxetyl group, dioxetyl group, tetrahydrofurfuryl group, oxazolidinyl group, tetrahydropyranyl group, and morpholinyl group. Substituents of the cyclic ether group represented by A ¹ include a halogen group and an alkyl group having 1 to 3 carbon atoms. The cyclic ether group may have multiple substituents, and in this case, the multiple substituents may be the same or different.

Examples of the divalent hydrocarbon group represented by R ⁴¹ include an alkylene group having 1 to 5 carbon atoms, and methylene group, ethylene group, trimethylene group, and propane-1,2-diyl group are preferable.

Structural units derived from (meth)acrylates having a cyclic ether group contained in the B block include structural units derived from (meth)acryloylmorpholine, structural units derived from tetrahydrofurfuryl (meth)acrylate, Structural units derived from 2-(4-morpholinyl)ethyl (meth)acrylic acid are preferred.

When the B block contains a structural unit derived from (meth)acrylate having a cyclic ether group, its content is preferably 5% by mass or more, more preferably 10% by mass or more, based on 100% by mass of the B block. , more preferably 15 mass% or more, preferably 50 mass% or less, more preferably 45 mass% or less, further preferably 40 mass% or less.

Examples of the structural unit derived from (meth)acrylate having an aromatic group contained in the B block include the structural unit represented by formula (42).

[In formula (42), A ² represents an aromatic group that may have a substituent. R ⁴³ represents a divalent hydrocarbon group. R ⁴⁴ represents a hydrogen atom or a methyl group.]

Examples of the aromatic group represented by A ² include a phenyl group and a naphthyl group. Examples of the substituent of the aromatic group represented by A ² include a halogen group and an alkyl group having 1 to 3 carbon atoms. The aromatic group may have multiple substituents, and in this case, the multiple substituents may be the same or different.

Examples of the divalent hydrocarbon group represented by R ⁴³ include an alkylene group having 1 to 5 carbon atoms, and methylene group, ethylene group, trimethylene group, and propane-1,2-diyl group are preferable.

As the structural unit derived from (meth)acrylate having an aromatic group contained in the B block, a structural unit derived from benzyl (meth)acrylate and a structural unit derived from phenyl (meth)acrylate are preferable.

When the B block contains a structural unit derived from (meth)acrylate having an aromatic group, its content is preferably 5% by mass or more, more preferably 10% by mass or more, based on 100% by mass of the B block. More preferably, it is 15 mass% or more, preferably 50 mass% or less, more preferably 45 mass% or less, and even more preferably 40 mass% or less.

Examples of the structural unit derived from (meth)acrylate having a monocyclic cyclic alkyl group contained in the B block include the structural unit represented by formula (43).

[In formula (43), A ³ represents a cyclic alkyl group with a monocyclic structure that may have a substituent. R ⁴⁵ represents a divalent hydrocarbon group. R ⁴⁶ represents a hydrogen atom or a methyl group.]

Examples of the cyclic alkyl group with a monocyclic structure represented by A ³ include cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, and cyclooctyl group. Substituents of the cyclic alkyl group represented by A ³ include a halogen group and an alkyl group having 1 to 3 carbon atoms. The cyclic alkyl group may have multiple substituents, and in this case, the multiple substituents may be the same or different.

Examples of the divalent hydrocarbon group represented by R ⁴⁵ include an alkylene group having 1 to 5 carbon atoms, and methylene group, ethylene group, trimethylene group, and propane-1,2-diyl group are preferable.

Structural units derived from (meth)acrylates having a monocyclic cyclic alkyl group contained in the B block include structural units derived from cyclohexyl (meth)acrylate and structural units derived from methylcyclohexyl (meth)acrylate. is desirable.

When the B block contains a structural unit derived from (meth)acrylate having a cyclic alkyl group of a monocyclic structure, its content is preferably 5% by mass or more, more preferably 10% by mass, based on 100% by mass of the B block. It is % by mass or more, more preferably 15 mass % or more, preferably 50 mass % or less, more preferably 45 mass % or less, and even more preferably 40 mass % or less.

The B block has a content of the structural unit represented by (1) above, preferably 10 mass% or less, more preferably 8 mass% or less, further preferably 7 mass% or less, especially preferably 5 mass%. As follows, it is particularly preferable that it does not contain the structural unit represented by formula (1).

When two or more types of structural units are contained in the B block, the various structural units contained in the B block may be contained in any one of random copolymerization and block copolymerization in the B block, and may be random from the viewpoint of uniformity. It is preferable that it is contained in the form of copolymerization. For example, the B block may be formed by a copolymer of a structural unit made of a b1 block and a structural unit made of a b2 block.

(block copolymer)

The structure of the block copolymer is preferably a linear block copolymer. In addition, the linear block copolymer may have any structure (arrangement), but from the viewpoint of the physical properties of the linear block copolymer or the physical properties of the composition, when the A block is expressed as A and the B block is expressed as B, (AB) _m type , (AB) _m -A type and (BA) _m -B type (m is an integer of 1 or more, for example, an integer of 1 to 3). It is preferable that it is a copolymer having at least one type of structure selected from the group consisting of . Among these, AB type diblock copolymer is preferable from the viewpoint of handleability during processing and the physical properties of the composition. By constructing an AB-type diblock copolymer, the structural unit represented by formula (1) in the A block and the structural unit represented by formula (3) in the B block are localized, effectively forming a colorant and a dispersion medium ( It is thought that it can work well with solvents. The block copolymer may have blocks other than A blocks and B blocks.

The content of the A block is preferably 50% by mass or more, more preferably 55% by mass or more, further preferably 60% by mass or more, and preferably 95% by mass or less, based on the total 100% by mass of the block copolymer. , more preferably 90 mass% or less, further preferably 80 mass% or less. The content of the B block is preferably 5% by mass or more, more preferably 10% by mass or more, further preferably 15% by mass or more, and preferably 50% by mass or less, based on the total 100% by mass of the block copolymer. , more preferably 45 mass% or less, further preferably 40 mass% or less. By adjusting the content of A block and B block within the above range, the dispersion performance when used as a dispersant is further improved.

The mass ratio (A block/B block) of the A block and B block in the block copolymer is preferably 50/50 or more, more preferably 55/45 or more, further preferably 60/40 or more, and 95/5. The ratio is preferably below, more preferably below 90/10, and still more preferably below 80/20. If the mass ratio of the A block and the B block is within the above range, the dispersion performance when used as a dispersant is further improved.

The content of the structural unit represented by formula (1) is preferably 10% by mass or more, more preferably 15% by mass or more, further preferably 20% by mass or more, based on the total 100% by mass of the block copolymer. Preferably it is 40 mass% or more, preferably 90 mass% or less, more preferably 85 mass% or less, and still more preferably 80 mass% or less.

The content of the structural unit represented by formula (3) is preferably 3% by mass or more, more preferably 5% by mass or more, and still more preferably 10% by mass or more, based on 100% by mass of the total block copolymer. 50 mass% or less is preferable, more preferably 45 mass% or less, further preferably 40 mass% or less, particularly preferably 30 mass% or less.

The molecular weight of the block copolymer is measured by gel permeation chromatography (hereinafter referred to as “GPC”). The weight average molecular weight (Mw) of the block copolymer is preferably 3,000 or more, more preferably 5,000 or more, further preferably 7,000 or more, particularly preferably 10,000 or more, and preferably 40,000 or less. It is 35,000 or less, more preferably 30,000 or less. If the weight average molecular weight is within the above range, the dispersion performance becomes better when used as a dispersant.

The molecular weight distribution (Mw/Mn) of the block copolymer is preferably 2.5 or less, more preferably 2.0 or less, and still more preferably 1.6 or less. In addition, in the present invention, molecular weight distribution (Mw/Mn) is obtained by (weight average molecular weight of block copolymer (Mw))/(number average molecular weight of block copolymer (Mn)). The smaller Mw/Mn, the narrower the molecular weight distribution, resulting in a copolymer with a uniform molecular weight. When the value is 1.0, the molecular weight distribution is narrowest. That is, the lower limit of Mw/Mn is 1.0. When the molecular weight distribution (Mw/Mn) of the block copolymer exceeds 2.5, those with low molecular weight and those with high molecular weight are included.

The amine titer of the block copolymer is preferably 10 mgKOH/g or less, more preferably 1 mgKOH/g or less, and still more preferably 0.1 mgKOH/g or less. It is preferable that the block copolymer has substantially no amine titer (amine titer is 0 mgKOH/g).

The acid value of the block copolymer is preferably 20 mgKOH/g or less, more preferably 10 mgKOH/g or less, and still more preferably 5 mgKOH/g or less. It is preferable that the block copolymer has substantially no acid value (an acid value of 0 mgKOH/g).

(Method for producing block copolymer)

As a method for producing a block copolymer, an A block is first produced through a polymerization reaction of a vinyl monomer, and then the B block monomer is polymerized into the A block; the B block is first produced and the A block monomer is added to the B block. Method of polymerization; Examples include manufacturing A blocks and B blocks separately and then coupling the A blocks and B blocks.

The polymerization method is not particularly limited, but living radical polymerization is preferred. That is, as a block copolymer, one polymerized by living radical polymerization is preferable. The living radical polymerization method maintains the simplicity and versatility of the conventional radical polymerization method, but is unlikely to cause arrest reactions or chain transfers, and grows without being hindered by side reactions that deactivate growth terminals. Therefore, precise control of molecular weight distribution, This is desirable because it is easy to manufacture a polymer with a uniform composition.

The living radical polymerization method uses a compound that can generate nitroxide radicals due to differences in the method of stabilizing the polymer growth terminal (nitroxide method; NMP method); using a metal complex such as copper or ruthenium; , a method of using a halogenated compound as a polymerization initiating compound and polymerizing living from the polymerization initiating compound (ATRP method); a method using a dithiocarboxylic acid ester or xanthate compound (RAFT method); using an organic tellurium compound Method (TERP method); Method using an organic iodine compound (ITP method); Method using an iodine compound as a polymerization initiator compound and an organic compound such as a phosphorus compound, nitrogen compound, oxygen compound, or hydrocarbon as a catalyst (reversible transfer catalyst) There are methods such as polymerization (RTCP method) and reversible catalyst-mediated polymerization (RCMP method). Among these methods, it is preferable to use the TERP method from the viewpoints of diversity of monomers that can be used, molecular weight control in the polymer region, uniform composition, or coloring.

The TERP method is a method of polymerizing a radically polymerizable compound (vinyl monomer) using an organic tellurium compound as a chain transfer agent, for example, International Publication No. 2004/14848, International Publication No. 2004/14962, International Publication No. This is a method described in Publication No. 2004/072126, and International Publication No. 2004/096870.

Specific polymerization methods of the TERP method include (a) to (d) below.

(a) A method of polymerizing a vinyl monomer using an organic tellurium compound represented by formula (6).

(b) A method of polymerizing a vinyl monomer using a mixture of an organic tellurium compound represented by formula (6) and an azo-based polymerization initiator.

(c) A method of polymerizing a vinyl monomer using a mixture of an organic tellurium compound represented by formula (6) and an organic ditelluride compound represented by formula (7).

(d) A method of polymerizing a vinyl monomer using a mixture of an organic tellurium compound represented by formula (6), an azo-based polymerization initiator, and an organic ditelluride compound represented by formula (7).

[In General Formula (6), R ⁶¹ represents an alkyl group, an aryl group, or an aromatic heterocyclic group having 1 to 8 carbon atoms. R ⁶² and R ⁶³ each independently represent a hydrogen atom or an alkyl group having 1 to 8 carbon atoms. R ⁶⁴ represents an alkyl group having 1 to 8 carbon atoms, an aryl group, a substituted aryl group, an aromatic heterocyclic group, an alkoxy group, an acyl group, an amide group, an oxycarbonyl group, a cyano group, an allyl group, or a propargyl group.

In general formula (7), R ⁶¹ represents an alkyl group, an aryl group, or an aromatic heterocyclic group having 1 to 8 carbon atoms.]

The organic tellurium compound represented by the general formula (6) is specifically ethyl=2-methyl-2-n-butyltellanyl-propionate, ethyl=2-n-butyltellanyl-propionate, ( 2-hydroxyethyl)=2-methyl-methyltellanyl-propionate, etc., International Publication No. 2004/14848, International Publication No. 2004/14962, International Publication No. 2004/072126, and International Publication No. 2004/ Examples include the organic tellurium compound described in No. 096870. Specific examples of the organic ditelluride compound represented by general formula (7) include dimethylditelluride, dibutylditelluride, 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(2,4-dimethylvaleronitrile) (ADVN), 1,1'-azobis(1-cyclohexanecarbonitrile) (ACHN), 2,2'-azobis(4-methoxy-2) , 4-dimethylvaleronitrile) (V-70), etc.

In the polymerization process, in a vessel replaced with an inert gas, a vinyl monomer and an organic tellurium compound of general formula (6) are added for the purpose of promoting the reaction and controlling the molecular weight and molecular weight distribution depending on the type of vinyl monomer. A crude polymerization initiator and/or an organic ditelluride compound of general formula (7) are mixed. At this time, examples of the inert gas include nitrogen, argon, and helium. Preferably, argon or nitrogen are good. The amount of vinyl monomer used in (a), (b), (c), and (d) may be appropriately adjusted depending on the physical properties of the target copolymer.

The polymerization reaction can be carried out without a solvent, but may be carried out by stirring the mixture using an aprotic solvent or a protic solvent generally used in radical polymerization. Aprotic solvents that can be used include, for example, acetonitrile, methyl ethyl ketone, anisole, benzene, toluene, propylene glycol monomethyl ether acetate, ethyl acetate, tetrahydrofuran (THF), and N,N-dimethylform. Amide (DMF), dimethyl sulfoxide (DMSO), N-methyl-2-pyrrolidone (NMP), acetone, dioxane, chloroform, carbon tetrachloride, trifluoromethylbenzene, etc. Moreover, examples of protonic solvents include water, methanol, ethanol, isopropanol, n-butanol, ethyl cellosolve, butyl cellosolve, 1-methoxy-2-propanol, hexafluoroisopropanol, and diacetone alcohol. etc. can be mentioned. The solvent may be used individually, or two or more types may be used together. The amount of solvent used may be adjusted appropriately, and for example, 0.01 ml to 50 ml is preferable per 1 g of vinyl monomer. The reaction temperature and reaction time may be appropriately adjusted depending on the molecular weight or molecular weight distribution of the resulting copolymer, but usually the mixture is stirred at 0°C to 150°C for 1 minute to 100 hours. After completion of the polymerization reaction, the target copolymer can be separated from the resulting reaction mixture by removing the used solvent and remaining vinyl monomer using normal separation and purification means.

The growth end of the copolymer obtained by the polymerization reaction is in the form of -TeR ⁶¹ (wherein R ⁶¹ is the same as above) derived from a tellurium compound, and is deactivated by operation in the air after completion of the polymerization reaction. There are cases where rurium atoms remain. Since the copolymer with tellurium atoms remaining at the ends may be colored or have poor thermal stability, it is preferable to remove the tellurium atoms. Methods for removing tellurium atoms include a radical reduction method, a method of adsorption with activated carbon, etc., a method of adsorbing metal with an ion exchange resin, etc., and these methods can also be used in combination. In addition, the other end of the copolymer obtained by the polymerization reaction (the end opposite to the growth end) is -CR ⁶² R ⁶³ R ⁶⁴ derived from a tellurium compound (wherein R ⁶² , R ⁶³ and R ⁶⁴ are represented by the formula (Same as R ⁶² , R ⁶³ and R ⁶⁴ in (6)).

＜Dispersant＞

The dispersant of the present invention contains the above block copolymer. The dispersant contains the block copolymer as a main component (50% by mass or more), preferably contains 75% by mass or more of the block copolymer, and more preferably consists only of the block copolymer.

In addition, the dispersant has particularly high dispersing performance for carbon black, which is a black colorant, and can suppress aggregation. Additionally, like carbon black, the dispersant exhibits excellent dispersing performance for carbon particles such as carbon nanotubes and graphene. Therefore, the dispersant of the present invention can be suitably used as a dispersant for carbon particles and can also be used in a conductive composition.

Dispersion of the coloring material becomes easy by using the dispersant as a dispersant solution before preparing the coloring composition. The solvent used in the dispersant solution is preferably a solvent that can dissolve the dispersant, does not react with these components, and is moderately volatile. Examples of the solvent include a dispersion medium used in the coloring composition described later. The content rate of the solvent in the dispersant solution is not particularly limited and can be adjusted appropriately. The upper limit of the solvent content in the dispersant solution is usually 99% by mass. In addition, the lower limit of the content of the dispersion medium in the dispersant solution is usually 10% by mass, and is preferably 30% by mass, taking into account the viscosity appropriate for the production of the coloring composition described later.

<Coloring composition>

The coloring composition of the present invention contains a dispersant (block copolymer), a colorant, and an aqueous dispersion medium.

(colorant)

The colorant is not particularly limited, and pigments and dyes that are conventionally used as colorants in paints can be used, but pigments are preferable from the viewpoint of light resistance and heat resistance. Examples of the pigment include pigments of various colors such as red pigment, yellow pigment, orange pigment, blue pigment, green pigment, purple pigment, and black pigment. The structure of the pigment includes azo pigments such as monoazo pigments, diazo pigments, and condensed diazo pigments, diketopyrrolopyrrole pigments, phthalocyanine pigments, isoindolinone pigments, isoindoline pigments, and quinacridone pigments. Organic pigments such as polycyclic pigments such as pigments, indigo-based pigments, thioindigo-based pigments, quinophthalone-based pigments, dioxazine-based pigments, anthraquinone-based pigments, perylene-based pigments, and perinone-based pigments; carbon black, graphene, carbon Inorganic pigments such as nanotubes, graphite, titanium black, and metal oxides such as copper, iron, manganese, cobalt, chromium, nickel, zinc, calcium, and silver, complex oxides, metal sulfides, metal sulfates, and metal carbonates. there is. The pigment contained in the coloring composition may be of only one type, or may be of multiple types.

Since the block copolymer exhibits excellent dispersion performance, especially for black pigments and blue pigments, the coloring material is preferably at least one selected from the group consisting of black pigments and blue pigments.

As black pigments, carbon black such as panel black, channel black, acetylene black, thermal black, lamp black, and bone black; graphene; carbon nanotubes such as single-layer carbon nanotube and multi-layer carbon nanotube; vapor-grown carbon nanofiber. Carbon nanofibers such as fullerene, natural graphite, graphite, perylene-based pigments, lactam-based pigments, titanium black, metal oxides such as copper, iron, manganese, cobalt, chromium, nickel, zinc, calcium, and silver; complex oxides; metals Sulfide; metal sulfate; metal carbonate, etc. are mentioned. Among these, at least one type of carbon particle selected from the group consisting of carbon black, graphene, carbon nanotubes and carbon nanofibers is preferable, and more preferably at least one type of carbon particle selected from the group consisting of carbon black and carbon nanotubes. It is a type of carbon particle.

The primary particle diameter of the carbon particles is not particularly limited, but is preferably 5 nm to 100 nm.

The specific surface area of the carbon particles is preferably 300 m ² /g to 1300 m ² /g, more preferably 400 m ² /g to 800 m ² /g. The specific surface area is measured according to JIS K 6217-3 (2001).

The DBP (dibutyl phthalate) oil absorption of the carbon particles is preferably 50 ml/100 g to 150 ml/100 g, and more preferably 80 ml/100 g to 120 ml/100 g. DBP oil absorption amount is measured according to JIS K 6217-4 (2017).

The surface of the carbon particles may be oxidized. By performing oxidation treatment, a carboxyl group or a phenolic hydroxy group can be added to the surface of the carbon particles. Oxidation treatment can be performed by treating the surface of the carbon particles with ozone, nitric acid, or the like. Carbon particles with carboxyl groups or phenolic hydroxy groups added to the surface have an acidic pH.

When 1 g of carbon particles is dispersed in 100 ml of water (25°C), the pH of the dispersion liquid is preferably 3 to 9, more preferably 5 to 9.

Examples of the blue pigment include organic pigments containing organic compounds as main components, such as phthalocyanine-based pigments, anthraquinone-based pigments, and dioxazine-based pigments, and these can be used one type or in a mixture of two or more types. Among these, phthalocyanine pigments are preferable, and metal phthalocyanine pigments and monohalogenated metal phthalocyanine pigments (halogenated metal phthalocyanine pigments having one halogen atom in the molecule) are more preferable. In addition, since polyhalogenated metal phthalocyanine pigments (halogenated metal phthalocyanine pigments having two or more halogen atoms in the molecule) are green pigments, polyhalogenated metal phthalocyanine pigments are not included in the phthalocyanine-based pigments used as blue pigments.

As a phthalocyanine pigment, a compound represented by general formula (8) is particularly preferable. Since copper phthalocyanine pigments and monohalogenated copper phthalocyanine pigments have a transmission region in a short wavelength region, they can form a colored layer with higher brightness.

[In Formula (8), R ⁸ each independently represents a hydrogen atom or a halogen atom. However, the number of halogen atoms in R ⁸ is 0 or 1.]

R ⁸ is preferably a hydrogen atom because light in a short wavelength range can be transmitted satisfactorily and the effect of the present invention can be easily achieved.

According to the compound classified as a peakment in the color index (C.I.) as a blue pigment, specifically, C.I. Pigment Blue 1, 1:2, 9, 14, 15, 15:1, 15:2, 15:3, 15:4, 15:5, 15:6, 16, 17, 17:1, 19, 22, 25, 27, 28, 29, 33, 35, 36, 56, 56:1, 60, 61, 61:1, 62, 63, 66, 67, 68, 71, 72, 73, 74, 75, 76, Examples include 78, 79, and 80. As a phthalocyanine pigment, C.I. Pigment Blue 15, 15:1, 15:2, 15:3, 15:4, 15:6, 16, 17, 17:1, and 75 are preferable, and examples of copper phthalocyanine pigments and monohalogenated copper phthalocyanine pigments include C.I. Pigment Blue 15, 15:1, 15:2, 15:3, 15:4, 15:6, 16, 17, 17:1 are preferred. As an anthraquinone pigment, C.I. Pigment Blue 60 is preferred. As a dioxazine pigment, C.I. Pigment Blue 80 is preferred.

The number average particle diameter of the pigment may be appropriately selected depending on its use and is not particularly limited. From the viewpoint of high brightness, the coloring composition preferably contains a pigment having a number average particle diameter of 10 nm to 150 nm.

The pigment may contain a dye derivative as a dispersion aid. This dye derivative has a functional group introduced into the dye skeleton. As the pigment skeleton, a skeleton identical or similar to the pigment constituting the coloring composition and a skeleton identical or similar to the compound serving as a raw material for the pigment are preferred. Specific examples of the dye skeleton include azo-based dye skeleton, phthalocyanine-based dye skeleton, anthraquinone-based dye skeleton, triazine-based dye skeleton, acridine-based dye skeleton, and perylene-based dye skeleton.

The amount of the pigment derivative used is not particularly limited, but for example, it is preferably 4 parts by mass to 17 parts by mass with respect to 100 parts by mass of the pigment.

The upper limit of the content of the colorant in the coloring composition is usually 80% by mass, preferably 70% by mass, and more preferably 60% by mass, based on the total solid content of the coloring composition from the viewpoint of brightness. Moreover, the lower limit of the content of the colorant in the coloring composition is usually 3% by mass, preferably 20% by mass, and more preferably 30% by mass, based on the total solid content of the coloring composition. Here, solid content refers to components other than the dispersion medium described later.

The content of the dispersant relative to the coloring material in the coloring composition is preferably 5 parts by mass to 200 parts by mass, preferably 10 parts by mass to 100 parts by mass, and 10 parts by mass to 80 parts by mass with respect to 100 parts by mass of the coloring material. It is more desirable.

(Aqueous dispersion medium)

Examples of the aqueous dispersion medium include water or an aqueous solvent (solvent miscible with water). Specifically, alcohols such as methanol, ethanol, propanol, isopropyl alcohol, butanol, 1-methoxy-2-propanol, 1-butoxy-2-propanol, propylene glycol-n-butyl ether; ethylene glycol, propylene Polyhydric alcohols such as glycol, butylene glycol, triethylene glycol, diethylene glycol, polyethylene glycol, polypropylene glycol, and glycerin; tetrahydrofuran, dioxane, ethylene glycol methyl ether, ethylene glycol ethyl ether, diethylene glycol methyl ether , ethers such as diethylene glycol ethyl ether, triethylene glycol, monomethyl ether, and monoethyl ether; ketones such as acetone, methyl ethyl ketone, and isobutyl ketone; amides such as dimethyl formaldehyde and dimethyl acetamide, etc. You can. Among these, alcohols and glycols are preferable. The aqueous solvent may be used individually, or two or more types may be used together.

The content of the aqueous dispersion medium in the coloring composition is not particularly limited and can be adjusted appropriately. The upper limit of the content of the aqueous dispersion medium in the coloring composition is usually 99% by mass. Moreover, the lower limit of the content of the aqueous dispersion medium in the coloring composition is usually 60% by mass, and is preferably 80% by mass, considering the viscosity appropriate for application of the coloring composition.

Depending on the intended use, the coloring composition further contains additives such as film-forming resin, surfactant, leveling agent, filler, ultraviolet absorber, antioxidant, preservative, anti-fungal agent, viscosity modifier, pH adjuster, anti-foaming agent, and cross-linking agent. You can do it. Additionally, when conductive carbon particles (carbon black, carbon nanotubes, graphene, carbon nanofibers, etc.) are used in the coloring composition, they can be used for electrodes. In this case, additives such as electrode forming resin, electrode active material, surfactant, film forming aid, leveling agent, preservative, anti-fungal agent, viscosity modifier, pH adjuster, anti-foaming agent, and cross-linking agent may be added to the coloring composition.

(Resin for film formation)

The resin for forming a coating film is a component that becomes the main body of the film when a coating film is formed using a coloring composition. The resin for forming a coating film is not particularly limited, and those used in conventional coating materials can be used. Examples of coating film-forming resins include thermosetting resins, thermoplastic resins, and polymerizable compounds (polymerizable resins, monomers with one polymerizable unsaturated bond in the molecule, monomers with two or more polymerizable unsaturated bonds in the molecule, oligomers, etc.). You can. Resin for coating film formation can be used individually or in mixture of two or more types. When blending the above resin for forming a coating film into a coloring composition, the content of the resin for forming a coating film is preferably 60% by mass to 95% by mass based on the total solid content of the coloring composition.

(thermosetting resin, thermoplastic resin)

Thermosetting resins and thermoplastic resins include, for example, butyral resin, styrene-maleic acid copolymer, chlorinated polyethylene resin, chlorinated polypropylene resin, vinyl chloride resin, vinyl chloride-vinyl acetate copolymer, vinyl acetate resin, urethane resin, Phenolic resin, polyester resin, acrylic resin, alkyd resin, styrene resin, styrene-acrylic resin, polyamide resin, rubber-based resin, cyclized rubber, epoxy resin, cellulose, polybutadiene, polyimide resin, benzoguanamine resin, melamine Resins, urea resins, silicone resins, fluororesins, etc. can be mentioned.

(polymerizable compound)

As a polymerizable resin as a polymerizable compound, a linear polymer having a reactive substituent such as a hydroxy group, carboxyl group, amino group, etc. is introduced through an isocyanate group, an aldehyde group, an epoxy group, etc., and a crosslinkable group such as a (meth)acrylic compound or cinnamic acid. Resin is used. Half-esterification of a linear polymer containing an acid anhydride such as styrene-maleic anhydride copolymer or α-olefin-maleic anhydride copolymer with a (meth)acrylic compound having a hydroxyl group such as hydroxyalkyl (meth)acrylate. Polymers are also used.

(Surfactants)

Examples of surfactants include nonionic surfactants, anionic surfactants, cationic surfactants, and amphoteric surfactants.

Examples of nonionic surfactants include fluorine-based surfactants, silicone-based surfactants, and polyoxyethylene-based surfactants.

As anionic surfactants, alkyl sulfonates, alkylbenzene sulfonates, alkylnaphthalene sulfonates, polyoxyethylene alkyl ether sulfonates, alkyl sulfates, alkyl sulfate ester salts, higher alcohol sulfuric acid ester salts, and aliphatic alcohol sulfuric acid. Ester salts, polyoxyethylene alkyl ether sulfates, polyoxyethylene alkyl phenyl ether sulfates, alkyl phosphoric acid ester salts, polyoxyethylene alkyl ether phosphates, polyoxyethylene alkyl phenyl ether phosphates, special polymer surfactants, etc. You can.

Examples of cationic surfactants include quaternary ammonium salts, imidazoline derivatives, and alkylamine salts.

Examples of amphoteric surfactants include betaine-type compounds, imidazolium salts, imidazolines, and amino acids.

(Leveling system)

Examples of the leveling agent include silicone-based, fluorine-based, etc. Silicone-based examples include dimethyl silicone oil, methylphenyl silicone oil, alkyl-modified silicone, alkoxy-modified silicone, oxyalkyl-modified silicone, glycol-modified silicone, polyether-modified silicone, polyether-modified silicone, and fatty acid ester-modified silicone. Examples of fluorine-based compounds include fluorocarbon-based compounds and fluorinated silicon. These can be used individually or in mixture of two or more types.

(filling)

As fillers, for example, silicon dioxide, alumina, zinc oxide, potassium titanate fiber, aluminum flake, stainless steel powder, tin powder, gold powder, metal-plated glass powder, titanium mica, calcium carbonate, barium sulfate, barium carbonate, kaolin, barium oxide. , clay, other metal oxides, composite metal oxides, etc., and can be used individually or in a mixture of two or more types to prevent a decrease in viscosity or poor gloss.

(Resin for electrode formation)

Resin for forming electrodes is used to bind particles such as active materials and conductive carbon materials, or conductive carbon particles, and a current collector. The resin for forming the electrode includes, for example, acrylic resin, polyurethane resin, polyester resin, phenol resin, epoxy resin, phenoxy resin, urea resin, melamine resin, alkyd resin, formaldehyde resin, silicone resin, and fluorine resin. , cellulose resins such as carboxymethylcellulose, synthetic rubbers such as styrenebutadiene rubber and fluororubber, conductive resins such as polyaniline and polyacetylene, and those containing fluorine atoms such as polyvinylidene fluoride, polyvinyl fluoride, and tetrafluoroethylene. and high molecular compounds. Additionally, modified products, mixtures, or copolymers of these resins can also be used. These resins can also be used 1 type or in combination of multiple types.

<Method for producing coloring composition>

The coloring composition can be prepared by mixing a colorant, a dispersant (block copolymer), an aqueous dispersion medium, and, if necessary, a resin for forming a coating film, a resin for forming an electrode, and other compounding agents. For mixing, for example, a mixing and dispersing machine such as a paint shaker, bead mill, ball mill, dissolver, or kneader can be used. The coloring composition is preferably filtered after mixing. Examples of the coloring composition include coating compositions for automobiles or compositions for forming electrodes. The composition for forming an electrode contains conductive carbon particles as a coloring material.

Application (coating) of the coloring composition to a processing object such as a stainless steel sheet or aluminum sheet includes, for example, roll coat, spin coat, flow coat, slot die coat, spray coat, dip coat, electrodeposition coat, electrostatic coat, or brush. This can be done using techniques such as painting or powder coating. Afterwards, if necessary, the solvent is evaporated by heating, and the coating film is dried and cured. At this time, heating or ultraviolet rays may be irradiated. The coating film obtained by applying the coloring composition may be formed by further applying one or two or more layers of top clear paint on the coating film. Top clear paint is a liquid paint that forms a colorless or colored transparent coating film composed of a resin component and a solvent as main components and additionally mixed with other paint additives as needed.

Example

Hereinafter, the present invention will be described in more detail based on specific examples. The present invention is not limited to the following examples at all, and can be implemented with appropriate modifications without changing the gist of the invention. In addition, the polymerization rate, weight average molecular weight (Mw), molecular weight distribution (Mw/Mn), amine value, and coating film physical properties of the block copolymer were evaluated according to the following methods.

Additionally, the meanings of the abbreviations are as follows.

BTEE: Ethyl=2-methyl-2-n-butyltellanyl-propionate

AIBN: 2,2'-azobis (isobutyronitrile)

BA: Butyl acrylate

M11EGA: Polyethylene glycol (degree of polymerization = 11) methyl ether acrylate (manufactured by Green, KOMERATE-A040TT)

BzA: Benzyl acrylate

CHA: Cyclohexyl acrylate

ACMO: 4-acryloylmorpholine

VP: N-vinyl-2-pyrrolidone

DMAEMA: Dimethylaminoethyl methacrylate

PMA: Propylene glycol monomethyl ether acetate

(polymerization rate)

¹ H-NMR was measured (solvent: CDCl ₃ , internal standard: TMS) using a nuclear magnetic resonance (NMR) measuring device (manufactured by BRUKER BIOSPIN GMBH, model: AVANCE500 (frequency 500 MHz)). For the obtained NMR spectrum, the integration ratio of the peak derived from the monomer and the peak derived from the polymer was determined, and the polymerization rate of the monomer was calculated.

(Weight average molecular weight (Mw) and molecular weight distribution (Mw/Mn))

It was determined by gel permeation chromatography (GPC) using a high-performance liquid chromatograph (manufactured by TOSOH CORPORATION, model HLC-8320). One column was SHODEX KF-603 (ϕ6mm×150mm) (manufactured by SHODEX), lithium bromide (10mmol/L)-acetic acid (10mmol/L)-methylpyrrolidone solution was used as a mobile phase, and a differential refractometer was used as a detector. The measurement conditions were the column temperature of 40°C, sample concentration of 20 mg/mL, sample injection amount of 10 μm, and flow rate of 0.2 mL/min. A calibration curve was created using polystyrene (molecular weight 70,500, 37,900, 19,920, 10,200, 4,290, 2,630, 1,150) as a standard material, and the weight average molecular weight (Mw) and number average molecular weight (Mn) were measured. The molecular weight distribution (Mw/Mn) was calculated from this measurement.

(amine)

The amine value represents the mass of the basic component and the equivalent weight of potassium hydroxide (KOH) per 1 g of solid content. The measurement sample was dissolved in tetrahydrofuran, and the obtained solution was neutralized and titrated with a hydrochloric acid (0.1 mol/L)-propanol solution using a potentiometric titrator (brand name: GT-06, manufactured by MITSUBISHI CHEMICAL CORPORATION). Using the inflection point of the titration pH curve as the titration end point, the amine titer (B) was calculated using the following equation.

B=56.11×Vs×0.1×f/w

B: Amine value (mgKOH/g)

Vs: Amount of hydrochloric acid (0.1 mol/L)-propanol solution required for titration (mL)

f: Titer of hydrochloric acid (0.1 mol/L)-propanol solution

w: Mass of the measured sample (g) (converted to solid content)

(black evaluation)

The black paint was applied to a stainless steel plate using a bar coater (#20), dried at 60°C for 10 minutes to form a coating film, and a test piece was produced.

The L value was measured on the film-forming surface of the obtained test piece using an L value measuring device (manufactured by KONICA MINOLTA JAPAN, INC., model CM-2600d) by removal of regular reflected light. Evaluation was performed on the black paint immediately after preparation and the black paint after adjustment and left at 35°C for 3 weeks.

(blue evaluation)

Blue paint (primary color) was applied to a 100 μm transparent film using a 52 μm bar, pre-dried at 60°C, dried at 140°C for 10 minutes to form a coating film, and a test piece was produced. Haze was measured on the film-forming surface of the obtained test piece using a Haze meter (manufactured by NIPPON DENSHOKU INDUSTRIES CO., LTD., model NDH-5000). Evaluation was performed on the blue paint (primary color) immediately after preparation and the blue paint (primary color) after preparation and stored at 35°C for 3 weeks.

In addition, blue paint (paint containing aluminum) was applied to a 100 μm transparent film using a 52 μm bar, pre-dried at 60°C, dried at 140°C for 10 minutes to form a coating film, and a test piece was produced. The film-forming surface of the obtained test piece was measured using a spectroscopic colorimeter (manufactured by KONICA MINOLTA JAPAN, Inc., model CM-2600d), and the saturation was calculated from C=(a ² +b ² ) ^1/2 .

(Microscopic observation)

The black paint was applied to a stainless steel plate using a bar coater (#20), dried at 60°C for 10 minutes to form a coating film, and a test piece was produced.

The coating film formation surface of the obtained test piece was observed using a microscope, and those where aggregation was not observed were evaluated as “○”, and those where aggregation was observed were evaluated as “×”.

＜Synthesis of block copolymer＞

(Block copolymer No. 1)

9.0 g of BA, 18.0 g of M11EGA, 0.05 g of AIBN, and 6.7 g of PMA were injected into a flask equipped with an argon gas introduction tube and a stirrer, and after nitrogen substitution, 0.45 g of BTEE was added and reacted at 60°C for 13 hours to form A block. was polymerized. The polymerization rate was 99%.

To the reaction solution, a mixed solution of 8.0 g of VP, 0.05 g of AIBN, and 8.3 g of PMA, which had previously been substituted with argon, was added and reacted at 60°C for 35 hours to polymerize the B block. The polymerization rate was 100%.

After completion of the reaction, the reaction solution was poured into stirred n-heptane. The precipitated polymer was suction filtered and dried to produce block copolymer No. got 1 Obtained block copolymer No. 1, Mw was 22,571 and Mw/Mn was 1.22.

(Block copolymer No. 2-9)

Block copolymer No. 1 was prepared in the same manner as the production method of block copolymer No. 1. 2 to 9 were produced. Table 1 lists the monomers used, organic tellurium compound, azo polymerization initiator, solvent, reaction conditions, and polymerization rate. Additionally, Table 2 lists the composition, Mw, Mw/Mn, and amine titer of each block copolymer. Additionally, the content of each structural unit in the copolymer was calculated from the injection ratio and polymerization rate of the monomer used in the polymerization reaction.

[Table 1]

[Table 2]

(Black paint No. 1 to 9)

As a dispersant, block copolymer No. obtained above was used. Black paint was prepared using Nos. 1 to 9. Specifically, each ingredient was added to a 50 mL mayonnaise bottle to achieve the formulation shown in Table 3, 66 g of zirconia beads (ϕ0.3 mm) were added, and a disperser (SKANDEX DISPERSER BA-S20, manufactured by O-WELL CORPORATION) was used. and stirred for 5 hours. After the stirring was completed, the beads were separated to obtain a pigment dispersion. By mixing the obtained pigment dispersion and clear paint, black paint No. 1 to 9 were prepared. Additionally, the obtained black paint No. For items 1 to 9, it was visually confirmed that the dispersibility of the carbon black was good.

[Table 3]

Black pigment 1: Product name “EMPEROR (registered trademark) 2000”, manufactured by CABOT CORPORATION, carbon black, pH 6 to 9

Antifoaming agent: Product name “BYK-024”, manufactured by BYK COPORATION, silicone-based surfactant

Acrylic resin: Brand name "WATERSOL (registered trademark) ACD-2001", manufactured by DIC CORPORATION, non-volatile matter: 40% by mass, solvent: water, propylene glycol-n-butyl ether

Melamine resin: Brand name “CYMEL (registered trademark) 303LF”, manufactured by Allnex, methylated melamine resin, non-volatile content: 100% by mass

(Blue paint No. 1 to 9)

As a dispersant, block copolymer No. obtained above was used. Blue paint (primary color, paint containing aluminum) was prepared using numbers 1 to 9. Specifically, each ingredient was added to a 50 mL mayonnaise bottle to achieve the formulation shown in Table 4, 66 g of zirconia beads (ϕ0.3 mm) were added, and a disperser (SKANDEX DISPERSER BA-S20, manufactured by O-WELL CORPORATION) was used. and stirred for 5 hours. After stirring was completed, the beads were filtered to obtain a pigment dispersion. By mixing the obtained pigment dispersion and clear paint, or the pigment dispersion and aluminum primary color, blue paint No. 1 to 9 (primary color, paint containing aluminum) were prepared. Additionally, the obtained blue paint No. For Nos. 1 to 9 (primary color, paint containing aluminum), it was visually confirmed that the dispersibility of the blue pigment was good.

[Table 4]

Blue pigment: Product name “CYANINE Blue G-314R”, SANYO COLOR WORKS, LTD. Manufacture, chlorinated copper phthalocyanine pigment (C.I. Pigment Blue 15:1)

Antifoaming agent: Product name “BYK-024”, manufactured by BYK COPORATION, silicone-based surfactant

Acrylic resin: Brand name "WATERSOL (registered trademark) ACD-2001", manufactured by DIC CORPORATION, non-volatile matter: 40% by mass, solvent: water, propylene glycol-n-butyl ether

Melamine resin: Brand name “CYMEL (registered trademark) 303LF”, manufactured by Allnex, methylated melamine resin, non-volatile content: 100% by mass

Aluminum for water-based use: Product name “STAPA IL HYDROLAN S 412”, manufactured by ECKART, aluminum paste

(Black paint No. 10)

As a dispersant, a black paint was prepared using block copolymer No. 1 obtained above. Specifically, each ingredient was added to a 50 mL mayonnaise bottle to achieve the formulation shown in Table 5, 66 g of zirconia beads (ϕ0.3 mm) were added, and a disperser (SKANDEX DISPERSER BA-S20, manufactured by O-WELL CORPORATION) was used. and stirred for 5 hours. After completion of stirring, the beads were filtered and black paint No. Prepared 10. Additionally, the obtained black paint No. About 10, it was visually confirmed that the dispersibility of the carbon nanotubes was good.

[Table 5]

Black pigment 2: Product name “Nanocyl7000”, manufactured by NANOCOYL, multilayer carbon nanotubes

Antifoaming agent: Product name “BYK-024”, manufactured by BYK COPORATION, silicone-based surfactant

Block copolymer No. 1 to 8 have an A block containing a structural unit represented by formula (1) and a B block containing a structural unit represented by formula (3). These block copolymers no. The black paints using Nos. 1 to 8 had a low L value of the film produced immediately after preparation. Additionally, these block copolymers No. The coating film formed from the blue paint (primary color) using Nos. 1 to 8 had a low haze value after preparation. Therefore, these block copolymers no. 1 to 8 have high dispersion performance for either the black colorant or the blue colorant.

In addition, block copolymer No. For the black paints using Nos. 1 to 5, the L value of the film produced after preparation and storage for 3 weeks was also low. Block copolymer No. The blue paint (primary color) using Nos. 1 to 5 had a low haze value and high saturation of the film formed after preparation and storage for 3 weeks.

In addition, block copolymer No. Black paint No. 1 prepared using 1. 10, the dispersion performance of carbon nanotubes (carbon particles) was also excellent. In addition, block copolymer No. 2 to 8 are block copolymer No. Since it has the same structure as 1, these block copolymers No. It is thought that the dispersion performance of 2 to 8 degree carbon nanotubes (carbon particles) is high.

Block copolymer No. 9 is a case where it does not have a B block containing the structural unit represented by formula (3). This block copolymer no. The black paint using No. 9 had a high L value of the film produced both immediately after preparation and after storage for 3 weeks. Additionally, this block copolymer No. As for the blue paint (primary color) using 9, the haze value of the film produced immediately after preparation was relatively low, but the haze value of the film produced after storage for 3 weeks was high. In addition, block copolymer No. The saturation of the paint film formed from the blue paint (paint containing aluminum) using 9 was low.

The present invention includes the following aspects.

(Aspect 1)

A block copolymer characterized by having an A block containing a structural unit represented by formula (1) and a B block containing a structural unit represented by formula (3).

[In Formula (1), n1 represents an integer of 2 to 30. R ¹¹ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. R ¹² represents an alkylene group having 1 to 3 carbon atoms. R ¹³ represents a hydrogen atom or a methyl group. In addition, plural R ¹² may be the same or different.]

[In formula (3), R ³¹ , R ³² , R ³³ and R ³⁴ are the same or different and represent a hydrogen atom or an alkyl group of 1 to 10 carbon atoms which may have a substituent. m3 represents an integer from 0 to 4. n3 represents an integer from 1 to 3.]

(Aspect 2)

The block copolymer according to Embodiment 1, wherein the content of the structural unit represented by the formula (1) is 20% by mass to 95% by mass based on 100% by mass of the A block.

(Aspect 3)

The block copolymer according to Embodiment 1 or 2, wherein the content of the structural unit represented by the formula (3) is 50% by mass to 100% by mass based on 100% by mass of the B block.

(Aspect 4)

The block copolymer according to any one of aspects 1 to 3, wherein the mass ratio (A block/B block) of the A block and B block in the block copolymer is 50/50 to 95/5.

(Aspect 5)

The block copolymer according to any one of aspects 1 to 4, wherein the A block further contains a structural unit represented by formula (2).

[In formula (2), R ²¹ represents a chain-shaped or cyclic hydrocarbon group that may have a substituent. R ²² represents a hydrogen atom or a methyl group.]

(Aspect 6)

The B block further includes a structural unit derived from a (meth)acrylate having a cyclic ether group, a structural unit derived from a (meth)acrylate having an aromatic group, and a (meth)acrylate having a cyclic alkyl group of a monocyclic structure. The block copolymer according to any one of aspects 1 to 5, which has at least one structural unit selected from the group consisting of structural units derived from.

(Aspect 7)

The block copolymer according to any one of aspects 1 to 6, wherein the block copolymer has a molecular weight distribution (Mw/Mn) of 2.5 or less.

(Aspect 8)

The block copolymer according to any one of aspects 1 to 7, wherein the block copolymer has a weight average molecular weight (Mw) of 3,000 to 40,000.

(Aspect 9)

The block copolymer according to any one of aspects 1 to 8, wherein the block copolymer is polymerized by living radical polymerization.

(Aspect 10)

A dispersant comprising the block copolymer according to any one of aspects 1 to 9.

(Aspect 11)

A coloring composition comprising the dispersant, colorant, and aqueous dispersion medium according to Embodiment 10.

(Aspect 12)

The coloring composition according to mode 11, wherein the coloring material is at least one selected from the group consisting of carbon particles and phthalocyanine-based pigments.

(Aspect 13)

The coloring composition according to mode 12, further comprising at least one member selected from the group consisting of a resin for forming a coating film and a resin for forming an electrode.

(Aspect 14)

The coloring composition according to Embodiment 12 or 13, which is a coating composition for automobiles or a composition for forming electrodes.

(Aspect 15)

A coating film formed from the coloring composition according to any one of aspects 11 to 14.

The block copolymer of the present invention can be used as a dispersant for a coloring composition containing a colorant and an aqueous dispersion medium, and is particularly useful as a dispersant for carbon particles. The coloring composition of the present invention is useful for automobile paints and the like because the formed coating film has high jet blackness.

Claims (15)

A block copolymer characterized by having an A block containing a structural unit represented by formula (1) and a B block containing a structural unit represented by formula (3).

[In Formula (1), n1 represents an integer of 2 to 30. R ¹¹ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. R ¹² represents an alkylene group having 1 to 3 carbon atoms. R ¹³ represents a hydrogen atom or a methyl group. In addition, plural R ¹² may be the same or different.]

[In formula (3), R ³¹ , R ³² , R ³³ and R ³⁴ are the same or different and represent a hydrogen atom or an alkyl group of 1 to 10 carbon atoms which may have a substituent. m3 represents an integer from 0 to 4. n3 represents an integer from 1 to 3.] In claim 1,
A block copolymer wherein the content of the structural unit represented by the formula (1) is 20% by mass to 95% by mass in 100% by mass of the A block. In claim 1 or claim 2,
A block copolymer wherein the content of the structural unit represented by the formula (3) is 50% by mass to 100% by mass in 100% by mass of the B block. The method according to any one of claims 1 to 3,
A block copolymer wherein the mass ratio (A block/B block) of the A block and B block in the block copolymer is 50/50 to 95/5. The method according to any one of claims 1 to 4,
A block copolymer in which the A block further contains a structural unit represented by formula (2).

[In formula (2), R ²¹ represents a chain-shaped or cyclic hydrocarbon group that may have a substituent. R ²² represents a hydrogen atom or a methyl group.] The method according to any one of claims 1 to 5,
The B block further includes a structural unit derived from a (meth)acrylate having a cyclic ether group, a structural unit derived from a (meth)acrylate having an aromatic group, and a (meth)acrylate having a cyclic alkyl group of a monocyclic structure. A block copolymer having at least one type of structural unit selected from the group consisting of structural units derived from. The method according to any one of claims 1 to 6,
A block copolymer wherein the molecular weight distribution (Mw/Mn) of the block copolymer is 2.5 or less. The method according to any one of claims 1 to 7,
A block copolymer having a weight average molecular weight (Mw) of 3,000 to 40,000. The method according to any one of claims 1 to 8,
A block copolymer in which the block copolymer is polymerized by living radical polymerization. A dispersant comprising the block copolymer according to any one of claims 1 to 9. A coloring composition comprising the dispersant, colorant, and aqueous dispersion medium according to claim 10. In claim 11,
A coloring composition wherein the coloring material is at least one type selected from the group consisting of carbon particles and phthalocyanine-based pigments. In claim 12,
A coloring composition further containing at least one member selected from the group consisting of a resin for forming a coating film and a resin for forming an electrode. In claim 12 or claim 13,
A coloring composition, which is a coating composition for automobiles or a composition for forming electrodes. A coating film formed from the coloring composition according to any one of claims 11 to 14.