Block copolymer, dispersant, and colored composition

Abstract

[Problem] To provide a block copolymer which can be used as a dispersing agent for an aqueous composition and which exhibits high coloring agent dispersion performance. [Solution] This block copolymer is characterized by having a block A containing a structural unit represented by formula (1) and a block B containing a structural unit represented by formula (3). In formula (1), n1 denotes an integer between 2 and 30. R11 denotes a hydrogen atom or an alkyl group having 1-3 carbon atoms. R12 denotes an alkylene group having 1-3 carbon atoms. R13 denotes a hydrogen atom or a methyl group. Moreover, multiple R12 moieties may be the same as, or different from, each other.　In formula (3), R31, R32, R33 and R34 may be the same as, or different from, each other, and each denote a hydrogen atom or an optionally substituted alkyl group having 1-10 carbon atoms. m3 denotes an integer between 0 and 4. n3 denotes an integer between 1 and 3.

Description

[Technical Field]

[0001] The present invention relates to block copolymers, and more particularly to block copolymers that can be used as dispersants for colorants in colored compositions. [Background technology]

[0002] In recent years, from the perspective of preventing air pollution, there has been a demand to reduce emissions of volatile organic compounds (VOCs) from factories and businesses. Therefore, the switching to water-based paint compositions is being considered for paint compositions used to coat metal plates that make up the bodies of automobiles and other vehicles. Furthermore, automotive paint compositions require not only high levels of durability, acid resistance, car wash scratch resistance, and chipping resistance, but also improved transparency and color development in the finished appearance of the paint film.

[0003] The colorants used in paint compositions generally have hydrophobic surfaces. Furthermore, dispersants used in solvent-based paint compositions have low solubility in water and poor dispersion stability in aqueous dispersion media. In particular, carbon particles, such as carbon black used as a black colorant, have a small primary particle size and an extremely large specific surface area, resulting in very strong cohesive force. Therefore, carbon particles are difficult to disperse uniformly in aqueous dispersion media, and even when dispersed, they tend to aggregate. Additionally, conductive carbon particles are used as conductive additives in aqueous electrode-forming compositions, but they also suffer from dispersibility problems similar to those in paint compositions.

[0004] Therefore, techniques have been proposed to improve the dispersibility of carbon black in paint compositions using carbon black as a black coloring agent. For example, Patent Document 1 describes a method for improving the dispersibility of carbon black in paint compositions with a DBP oil supply rate of 150 ml / 100 g or less, an average primary particle diameter of 15 nm or less, and a specific surface area of ​​500 m². 2This document describes a highly jet-black carbon black dispersion (often referred to as jet black when the coloring agent is a black coloring agent) obtained by finely dispersing carbon black, which is contained in an acidic or neutral pH range, in an aqueous medium using a dispersant. 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)).

[0005] Furthermore, Patent Document 2 describes an aqueous coating composition containing (A) (a) a polymerizable unsaturated monomer having a specific cationic functional group, (b) a polymerizable unsaturated monomer having a polyoxyalkylene chain, and (c) a copolymer of other polymerizable unsaturated monomers, (B) a pigment, and (C) an acrylic resin containing acid groups and hydroxyl groups (see Patent Document 1 (Claim 1, paragraph 0014)).

[0006] On the other hand, regarding jet blackness, since carbon black is a reddish-black color, a method of enhancing its jet blackness by adding blue colorants (bluing agents) such as phthalocyanine pigments is known. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2008-285632 [Patent Document 2] Japanese Patent Publication No. 2014-5399 [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] While paint compositions using carbon particles as a black coloring agent have been proposed with improved dispersibility of the carbon particles, there is still room for improvement in preventing carbon particle aggregation. Furthermore, there is a need to improve the dispersibility of blue coloring agents (especially phthalocyanine pigments) using the same dispersant.

[0009] The present invention has been made in view of the above circumstances, and is a block copolymer that can be used as a dispersant for aqueous compositions such as aqueous paint compositions and aqueous compositions for forming electrodes, and has a high dispersibility of coloring materials (particularly carbon particles and blue coloring materials). It is an object to provide a block copolymer. Further, as a further problem, when used as a dispersant for a coloring composition containing carbon particles, it is possible to improve the jet blackness of the coating film, and when used as a dispersant for a coloring composition containing a blue coloring material, it is possible to improve the transparency and chroma of the coating film. It is an object to provide a block copolymer.

Means for Solving the Problems

[0010] The block copolymer of the present invention that has solved the above problems is characterized by having an A block containing a structural unit represented by the formula (1) and a B block containing a structural unit represented by the formula (3).

[0011]

Chemical formula

[0012]

Chemical formula

[0013] In the block copolymer of the present invention, the structural unit represented by formula (1) contained in block A has high affinity for aqueous dispersion media, and the structural unit represented by formula (3) contained in block B is adsorbed onto the coloring agent. Therefore, the block copolymer can be used as a dispersant for the coloring agent in an aqueous coloring composition containing an aqueous dispersion media and a coloring agent to improve the dispersibility of the coloring agent. [Effects of the Invention]

[0014] The block copolymer of the present invention can be used as a dispersant in aqueous compositions such as aqueous paint compositions and aqueous electrode-forming compositions, and exhibits particularly excellent dispersion performance for carbon particles and blue colorants. By using the block copolymer of the present invention as a dispersant in a coloring composition containing carbon particles (black colorant), the jet blackness of the coating film can be improved. Furthermore, by using the block copolymer of the present invention as a dispersant in a coloring composition containing a blue colorant, the transparency and saturation of the coating film can be improved.

[0015] Furthermore, since the block copolymer of the present invention exhibits excellent dispersibility of both carbon particles and blue colorants, it can be suitably used in aqueous coloring compositions containing carbon particles (black colorant) and blue colorants (blueing agent), and it is possible to obtain aqueous coloring compositions with excellent jet black properties. [Modes for carrying out the invention]

[0016] <Block copolymer> The block copolymer of the present invention is characterized by having a block A containing a structural unit represented by formula (1) and a block B containing a structural unit represented by formula (3).

[0017] The block copolymer contains a structural unit represented by formula (1) in block A, which has high affinity for aqueous dispersion media, and a structural unit represented by formula (3) in block B, which has a portion that adsorbs to the coloring agent. By using the block copolymer as a dispersant in an aqueous coloring composition containing a coloring agent, the dispersibility of the coloring agent can be improved.

[0018] The following describes an example of a preferred embodiment of the present invention. However, the following embodiments are merely illustrative. The present invention is not limited in any way to the following embodiments.

[0019] In this invention, "A block" can be replaced with "A segment," and "B block" can be replaced with "B segment." In this invention, "vinyl monomer" refers to a monomer having a radically polymerizable carbon-carbon double bond in its 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."

[0020] (Block A) Block A is a block containing a structural unit represented by formula (1). The structural unit represented by formula (1) in Block A may be of only one type, or it may contain two or more types.

[0021] [ka] [In equation (1), n1 represents an integer between 2 and 30. R 11 R represents a hydrogen atom or an alkyl group with 1 to 3 carbon atoms. 12 R represents an alkylene group with 1 to 3 carbon atoms. 13 R represents a hydrogen atom or a methyl group. Note that there are multiple R's.12 These may be the same or different.

[0022] In formula (1), n1 is 2 or greater, preferably 5 or greater, and 30 or less, preferably 20 or less, and more preferably 15 or less.

[0023] R 11 The alkyl group having 1 to 3 carbon atoms, as shown, may be linear or branched, but linear is preferred. 11 Specific examples of alkyl groups with 1 to 3 carbon atoms, as shown by the formula, include the methyl group, ethyl group, n-propyl group, and isopropyl group.

[0024] R 12 The alkylene group having 1 to 3 carbon atoms, as indicated by R, may be linear or branched, but linear is preferred. 12 Specific examples of alkylene groups with 1 to 3 carbon atoms, as shown by R, include the methylene group, ethylene group, trimethylene group, and propane-1,2-diyl group. 12 The group is preferably an ethylene group or a trimethylene group.

[0025] Examples of monomers constituting the structural unit represented by formula (1) include (meth)acrylates having a polyalkylene glycol structure. The polyalkylene glycol portion may be, for example, a mixture of ethylene oxide and propylene oxide. Examples of (meth)acrylates having a polyalkylene glycol structure include polyethylene glycol (degree of polymerization = 2-30) methyl ether (meth)acrylate, polyethylene glycol (degree of polymerization = 2-30) ethyl ether (meth)acrylate, polyethylene glycol (degree of polymerization = 2-30) propyl ether (meth)acrylate, and other polyethylene glycol (degree of polymerization = 2-30) propyl ether (meth)acrylate; and polypropylene glycol (degree of polymerization = 2-30) methyl ether (meth)acrylate, polypropylene glycol (degree of polymerization = 2-30) ethyl ether (meth)acrylate, polypropylene glycol (degree of polymerization = 2-30) propyl ether (meth)acrylate, and other polypropylene glycol structural units.

[0026] The content of the structural unit represented by formula (1) is preferably 20% by mass or more, more preferably 35% by mass or more, even more preferably 50% by mass or more, preferably 95% by mass or less, more preferably 90% by mass or less, and even more preferably 80% by mass or less, in 100% by mass of block A. If the content is 20% by mass or more, the affinity with aqueous dispersion media is further improved, and if it is 95% by mass or less, the affinity with coating film forming resin and electrode forming resin is further improved.

[0027] Block A preferably further contains structural units represented by formula (2). The structural units represented by formula (2) in Block A may be one type or two or more types. The presence of structural units represented by formula (2) in Block A further improves its affinity with the coating resin and the electrode forming resin.

[0028] [ka] [In equation (2), R21 R represents a chain or cyclic hydrocarbon group which may have substituents. 22 [This represents a hydrogen atom or a methyl group.]

[0029] R 21 Examples of chain-like hydrocarbon groups represented by include linear alkyl groups and branched alkyl groups. For linear alkyl groups, the number of carbon atoms is preferably 1 to 20, more preferably 1 to 10, and even more preferably 1 to 5. Examples of linear alkyl groups include methyl, ethyl, n-propyl, n-butyl, n-hexyl, n-octyl, n-nonyl, n-decyl, and n-lauryl groups. For branched alkyl groups, the number of carbon atoms is preferably 3 to 20, more preferably 3 to 10, and even more preferably 3 to 5. Examples of branched alkyl groups include isopropyl, isobutyl, sec-butyl, tert-butyl, 2-ethylhexyl, neopentyl, and isooctyl groups.

[0030] R 21 Examples of substituents on the chain-like hydrocarbon group represented by include halogen groups, alkoxy groups, benzoyl groups (-COC6H5), and hydroxyl groups.

[0031] R 21Examples of cyclic hydrocarbon groups represented by include cyclic alkyl groups and aromatic groups, and these cyclic alkyl groups and aromatic groups may have a chain portion. The number of carbon atoms in a cyclic alkyl group is preferably 4 to 18, more preferably 6 to 12, and even more preferably 6 to 10. Examples of cyclic alkyl groups include cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl groups. The number of carbon atoms in an aromatic group is preferably 6 to 18, more preferably 6 to 12, and even more preferably 6 to 8. Examples of aromatic groups include phenyl, tolyl, xylyl, and mesityl groups. Examples of the chain portion of cyclic alkyl groups and aromatic groups having a chain portion include alkylene groups with 1 to 12 carbon atoms, preferably alkylene groups with 1 to 6 carbon atoms, and more preferably alkylene groups with 1 to 3 carbon atoms.

[0032] R 21 Substituents that can be present in the cyclic hydrocarbon group represented by include halogen groups, alkoxy groups, linear alkyl groups, and hydroxyl groups.

[0033] Examples of vinyl monomers that form the structural unit represented by formula (2) include (meth)acrylates having a linear alkyl group (linear or branched alkyl group), (meth)acrylates having a cyclic alkyl group, (meth)acrylates having a polycyclic structure, and (meth)acrylates having an aromatic group. Among these, (meth)acrylates having a linear alkyl group (linear or branched alkyl group) and (meth)acrylates having a cyclic alkyl group are preferred.

[0034] Examples of (meth)acrylates having a linear alkyl group include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, n-butyl (meth)acrylate, n-pentyl (meth)acrylate, n-hexyl (meth)acrylate, n-octyl (meth)acrylate, n-nonyl (meth)acrylate, n-decyl (meth)acrylate, n-lauryl (meth)acrylate, and n-stearyl (meth)acrylate.

[0035] Examples of (meth)acrylates having the branched alkyl group include isopropyl (meth)acrylate, isobutyl (meth)acrylate, sec-butyl (meth)acrylate, tert-butyl (meth)acrylate, isooctyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isononyl (meth)acrylate, and isodecyl (meth)acrylate.

[0036] Examples of the cyclic alkyl group include cyclic alkyl groups having a monocyclic structure (for example, cycloalkyl groups). Specific examples of (meth)acrylates having a monocyclic cyclic alkyl group include cyclohexyl (meth)acrylate, methylcyclohexyl (meth)acrylate, and cyclododecyl (meth)acrylate.

[0037] Examples of polycyclic structures include cyclic alkyl groups having a bridged ring structure (e.g., 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, 2-methyl-2-adamantyl (meth)acrylate, and 2-ethyl-2-adamantyl (meth)acrylate.

[0038] Examples of aromatic groups include aryl groups, and may also have a chain portion, such as alkylaryl groups, aralkyl groups, and aryloxyalkyl groups. Specific examples of (meth)acrylates having aromatic groups include benzyl (meth)acrylate, phenyl (meth)acrylate, and phenoxyethyl (meth)acrylate.

[0039] When the structural unit represented by formula (2) is included, its content is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 20% by mass or more, preferably 80% by mass or less, more preferably 65% ​​by mass or less, and even more preferably 50% by mass or less, in 100% by mass of block A. If the content is 5% by mass or more, the affinity with the coating film-forming resin and the electrode-forming resin is further improved, and if it is 80% by mass or less, the affinity with the aqueous dispersion medium is further improved.

[0040] Block A may consist only of structural units represented by formula (1), or only of structural units represented by formula (1) and structural units represented by formula (2), or it may contain other structural units. The total content of structural units represented by formula (1) and structural units represented by formula (2) in Block A is preferably 70% by mass or more, more preferably 80% by mass or more, even more preferably 90% by mass or more, and particularly preferably 97% by mass or more.

[0041] Specific examples of vinyl monomers that can form other structural units of block A include (meth)acrylates having hydroxyl groups, (meth)acrylates having lactone-modified hydroxyl groups, (meth)acrylates having alkoxy groups, (meth)acrylates having acidic groups, (meth)acrylic acid, and (meth)acrylates having cyclic ether groups.

[0042] Examples of (meth)acrylates having a hydroxyl group include 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, and 12-hydroxylauryl (meth)acrylate. Among these, (meth)acrylates having a hydroxyalkyl group with 1 to 5 carbon atoms are more preferred.

[0043] Examples of lactone-modified (meth)acrylates having a hydroxyl group include those obtained by adding a lactone to the hydroxyl group-having (meth)acrylate, with caprolactone being preferred. The amount of caprolactone added is preferably 1 mol to 20 mol, and more preferably 1 mol to 10 mol. Examples of lactone-modified (meth)acrylates having a hydroxyl group include a 1 mol adduct of 2-hydroxyethyl (meth)acrylate to caprolactone, a 2 mol adduct of 2-hydroxyethyl (meth)acrylate to caprolactone, a 3 mol adduct of 2-hydroxyethyl (meth)acrylate to caprolactone, a 4 mol adduct of 2-hydroxyethyl (meth)acrylate to caprolactone, a 5 mol adduct of 2-hydroxyethyl (meth)acrylate to caprolactone, and a 10 mol adduct of 2-hydroxyethyl (meth)acrylate to caprolactone.

[0044] Examples of (meth)acrylates having an alkoxy group include methoxyethyl (meth)acrylate and ethoxyethyl (meth)acrylate.

[0045] Examples of acidic groups include carboxyl groups (-COOH), sulfonic acid groups (-SO3H), phosphate groups (-OPO3H2), phosphonic acid groups (-PO3H2), and phosphinic acid groups (-PO2H2). Examples of (meth)acrylates having the aforementioned acidic groups include (meth)acrylates having carboxyl groups, (meth)acrylates having phosphate groups, and (meth)acrylates having sulfonic acid groups.

[0046] Examples of (meth)acrylates having a carboxyl group include monomers obtained by reacting (meth)acrylates having a hydroxyl group, such as carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, 2-(meth)acryloyloxyethyl succinate, 2-(meth)acryloyloxyethyl maleate, and 2-(meth)acryloyloxyethyl phthalate, with acid anhydrides such as maleic anhydride, succinic anhydride, and phthalic anhydride. Examples of (meth)acrylates having a phosphate group include 2-(phosphonooxy)ethyl (meth)acrylate. Examples of (meth)acrylates having a sulfonic acid group include ethyl (meth)acrylate sulfonate.

[0047] Examples of (meth)acrylates having a cyclic ether group include glycidyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, (meth)acryloylmorpholine, 2-(4-morpholinyl)ethyl (meth)acrylate, (3-ethyloxetan-3-yl)methyl (meth)acrylate, (2-methyl-2-ethyl-1,3-dioxolan-4-yl)methyl (meth)acrylate, cyclic trimethylolpropaneformal (meth)acrylate, 2-[(2-tetrahydropyranyl)oxy]ethyl (meth)acrylate, and 1,3-dioxane-(meth)acrylate.

[0048] Block A preferably contains 3% by mass or less, more preferably 1% by mass or less, and even more preferably 0.1% by mass or less of the structural unit represented by formula (3), and it is particularly preferable that it does not contain the structural unit represented by formula (3).

[0049] If block A contains two or more structural units, the various structural units contained in block A may be contained in block A in any manner, such as random copolymerization or block copolymerization, and from the viewpoint of uniformity, it is preferable that they be contained in a manner of random copolymerization. For example, block A may be formed by a copolymer of structural units consisting of block a1 and structural units consisting of block a2.

[0050] (Block B) Block B is a block containing a structural unit represented by formula (3). The structural unit represented by formula (3) in Block B may be of only one type, or it may contain two or more types.

[0051] [ka] [In equation (3), R 31 , R 32 , R 33 and R 34 [The characters represent an alkyl group having 1 to 10 carbon atoms, which may have a hydrogen atom or substituents, and are identical or different. m3 represents an integer from 0 to 4. n3 represents an integer from 1 to 3.]

[0052] R 31 ~R 34 The number of carbon atoms in the alkyl group is preferably 1 to 6, more preferably 1 to 4. The alkyl group is even more preferably a methyl group or an ethyl group, and particularly preferably a methyl group. 31 ~R 34 The substituents in the compound are not particularly limited, but include carboxyl groups, sulfonic acid groups and their esters or salts; amino groups; hydroxyl groups, etc.

[0053] R 31 Preferably, the component is a hydrogen atom or a methyl group, and more preferably a hydrogen atom. R 32 ~R 34 A hydrogen atom is preferred as the atom.

[0054] m3 is preferably an integer between 0 and 2, more preferably an integer between 0 and 1, and even more preferably 0. n3 is preferably 1 or 2, and more preferably 1.

[0055] The structural unit represented by formula (3) is preferably the structural unit represented by formula (31).

[0056] [ka] [In equation (31), R 31 [where 'm' 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.]

[0057] Examples of vinyl monomers that form the structural unit represented by formula (3) include vinyl monomers having a 5-membered ring lactam structure such as N-vinylpyrrolidone, N-vinyl-5-methylpyrrolidone, N-vinyl-5-ethylpyrrolidone, N-vinyl-5-propylpyrrolidone, N-vinyl-5-butylpyrrolidone, and 1-(2-propenyl)-2-pyrrolidone; vinyl monomers having a 6-membered ring lactam structure such as N-vinylpiperidone; and vinyl monomers having a 7-membered ring lactam structure such as N-vinylcaprolactam. One or more vinyl monomers that form the structural unit represented by formula (3) can be used. Among these, vinyl monomers having a 5-membered ring lactam structure are preferred, and N-vinylpyrrolidone is more preferred.

[0058] The content of the structural unit represented by formula (3) is preferably 50% by mass or more, more preferably 55% by mass or more, even more preferably 60% by mass or more, particularly preferably 70% by mass or more, preferably 100% by mass or less, more preferably 95% by mass or less, and even more preferably 90% by mass or less, in 100% by mass or less. If the content is 50% by mass or more, aggregation of the coloring agent is suppressed, dispersibility is improved, and a coating film with excellent transparency, saturation, or jet blackness can be formed.

[0059] Block B may consist only of structural units represented by formula (3), or it may include other structural units.

[0060] Specific examples of vinyl monomers that can form other structural units in Block B include those identical to those exemplified as specific examples of monomers that can form other structural units in Block A, as well as vinyl monomers having a basic group.

[0061] The basic group is preferably an amino group due to the ease of obtaining raw materials and synthesizing them. In this specification, an amino group refers to a general amino group structure (-NH2), as well as a -NHR group in which H is substituted with a hydrocarbon group. 41 , -NR 41 R 42 (R 41 , R 42 Each of these independently represents a chain-like or cyclic hydrocarbon group. Also, R 41 and R 42 These may be bonded to each other to form a cyclic structure. This includes substituted amino groups represented by ) and nitrogen-containing heterocyclic groups (such as pyridyl groups and imidazole groups).

[0062] Specific examples of vinyl monomers having a basic group include dimethylaminoethyl (meth)acrylate, dimethylaminopropyl (meth)acrylate, dimethylaminobutyl (meth)acrylate, diethylaminoethyl (meth)acrylate, diethylaminopropyl (meth)acrylate, diethylaminobutyl (meth)acrylate, ethylaminoethyl (meth)acrylate, ethylaminopropyl (meth)acrylate, ethylaminobutyl (meth)acrylate, propylaminoethyl (meth)acrylate, propylaminopropyl (meth)acrylate, propylaminobutyl (meth)acrylate, dimethylaminopropyl (meth)acrylamide, and 4-vinylpyridine.

[0063] If block B contains other structural units, it is preferable that the other structural units be at least one selected from the group consisting of structural units derived from (meth)acrylate having a cyclic ether group, structural units derived from (meth)acrylate having an aromatic group, and structural units derived from (meth)acrylate having a monocyclic cyclic alkyl group.

[0064] A structural unit derived from a (meth)acrylate having a cyclic ether group contained in block B is the structural unit represented by formula (41).

[0065] [ka] [In equation (41), A 1 R represents a cyclic ether group which may have substituents. 41 R represents a divalent hydrocarbon group. 42 [This represents a hydrogen atom or a methyl group.]

[0066] A 1 Examples of cyclic ether groups represented by include oxetyl group, dioxetyl group, tetrahydrofurfuryl group, oxazolidinyl group, tetrahydropyranyl group, and morpholinyl group. 1 Substituents that can be present in the cyclic ether group represented by include halogen groups and alkyl groups having 1 to 3 carbon atoms. The cyclic ether group may have multiple substituents, in which case the multiple substituents may be the same or different. R 41 Examples of divalent hydrocarbon groups represented by include alkylene groups having 1 to 5 carbon atoms, with methylene groups, ethylene groups, trimethylene groups, and propane-1,2-diyl groups being preferred.

[0067] The structural units derived from the (meth)acrylate having a cyclic ether group contained in the aforementioned Block B are preferably structural units derived from (meth)acryloylmorpholine, structural units derived from tetrahydrofurfuryl (meth)acrylate, and structural units derived from 2-(4-morpholinyl)ethyl (meth)acrylate.

[0068] If block B contains structural units derived from (meth)acrylate having a cyclic ether group, the content of such units is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 15% by mass or more, preferably 50% by mass or less, more preferably 45% by mass or less, and even more preferably 40% by mass or less, based on 100% by mass of block B.

[0069] A structural unit derived from the aromatic group-containing (meth)acrylate contained in block B is the structural unit represented by formula (42).

[0070] [ka] [In equation (42), A 2 R represents an aromatic group which may have substituents. 43 R represents a divalent hydrocarbon group. 44 [This represents a hydrogen atom or a methyl group.]

[0071] A 2 Examples of aromatic groups represented by include phenyl groups and naphthyl groups. 2 Examples of substituents on the aromatic group represented by include halogen groups and alkyl groups having 1 to 3 carbon atoms. The aromatic group may have multiple substituents, in which case the multiple substituents may be the same or different. R 43 Examples of divalent hydrocarbon groups represented by include alkylene groups having 1 to 5 carbon atoms, with methylene groups, ethylene groups, trimethylene groups, and propane-1,2-diyl groups being preferred.

[0072] The structural units derived from (meth)acrylates having aromatic groups contained in Block B are preferably structural units derived from benzyl (meth)acrylate and structural units derived from phenyl (meth)acrylate.

[0073] If block B contains structural units derived from (meth)acrylate having aromatic groups, the content is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 15% by mass or more, preferably 50% by mass or less, more preferably 45% by mass or less, and even more preferably 40% by mass or less, based on 100% by mass of block B.

[0074] Structural units derived from (meth)acrylates having a monocyclic cyclic alkyl group contained in block B include the structural unit represented by formula (43).

[0075] [ka] [In equation (43), A 3 R represents a cyclic alkyl group with a monocyclic structure, which may have substituents. 45 R represents a divalent hydrocarbon group. 46 [This represents a hydrogen atom or a methyl group.]

[0076] A 3 Examples of cyclic alkyl groups representing a monocyclic structure include cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, and cyclooctyl group. 3 Substituents that can be present in a cyclic alkyl group represented by include halogen groups and alkyl groups having 1 to 3 carbon atoms. A cyclic alkyl group may have multiple substituents, in which case the multiple substituents may be the same or different. R 45 Examples of divalent hydrocarbon groups represented by include alkylene groups having 1 to 5 carbon atoms, with methylene groups, ethylene groups, trimethylene groups, and propane-1,2-diyl groups being preferred.

[0077] The structural units derived from (meth)acrylates having a monocyclic alkyl group contained in Block B are preferably structural units derived from cyclohexyl (meth)acrylate and structural units derived from methylcyclohexyl (meth)acrylate.

[0078] If block B contains structural units derived from (meth)acrylate having a monocyclic cyclic alkyl group, the content of such units is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 15% by mass or more, preferably 50% by mass or less, more preferably 45% by mass or less, and even more preferably 40% by mass or less, based on 100% by mass of block B.

[0079] Block B preferably contains 10% by mass or less, more preferably 8% by mass or less, even more preferably 7% by mass or less, and most preferably 5% by mass or less of the structural unit represented by formula (1), and it is particularly preferable that it does not contain the structural unit represented by formula (1).

[0080] If block B contains two or more structural units, the various structural units contained in block B may be contained in block B in any manner, such as random copolymerization or block copolymerization, and from the viewpoint of uniformity, it is preferable that they are contained in a manner of random copolymerization. For example, block B may be formed by a copolymer of structural units consisting of block b1 and structural units consisting of block b2.

[0081] (Block copolymer) The structure of the block copolymer is preferably a linear block copolymer. Furthermore, the linear block copolymer may have any structure (arrangement), but from the viewpoint of the physical properties of the linear block copolymer or the composition, when block A is denoted as A and block B as B, (AB) m Type, (AB) m -Type A and (BA) m- Preferably, the copolymer has at least one structure selected from the group consisting of type B (where m is an integer of 1 or more, for example, an integer from 1 to 3). Among these, type AB diblock copolymer is preferred from the viewpoint of handling ease during processing and physical properties of the composition. It is believed that by forming a type AB diblock copolymer, the structural unit represented by formula (1) is localized in block A and the structural unit represented by formula (3) is localized in block B, allowing for efficient and favorable interaction with the colorant and the dispersion medium (solvent). The block copolymer may have other blocks besides block A and block B.

[0082] The content of Block A is preferably 50% by mass or more, more preferably 55% by mass or more, even more preferably 60% by mass or more, preferably 95% by mass or less, more preferably 90% by mass or less, and even more preferably 80% by mass or less, based on 100% by mass of the entire block copolymer. The content of Block B is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 15% by mass or more, preferably 50% by mass or less, more preferably 45% by mass or less, and even more preferably 40% by mass or less, based on 100% by mass of the entire block copolymer. By adjusting the content of Block A and Block B within the above ranges, the dispersion performance when used as a dispersant is further improved.

[0083] The mass ratio of block A to block B in the block copolymer (block A / block B) is preferably 50 / 50 or higher, more preferably 55 / 45 or higher, even more preferably 60 / 40 or higher, preferably 95 / 5 or lower, more preferably 90 / 10 or lower, and even more preferably 80 / 20 or lower. If the mass ratio of block A to block B is within the above range, the dispersion performance when used as a dispersant will be further improved.

[0084] The content of the structural unit represented by formula (1) is preferably 10% by mass or more, more preferably 15% by mass or more, even more preferably 20% by mass or more, particularly preferably 40% by mass or more, preferably 90% by mass or less, more preferably 85% by mass or less, and even more preferably 80% by mass or less, based on 100% by mass of the entire block copolymer.

[0085] The content of the structural unit represented by formula (3) is preferably 3% by mass or more, more preferably 5% by mass or more, even more preferably 10% by mass or more, preferably 50% by mass or less, more preferably 45% by mass or less, even more preferably 40% by mass or less, and particularly preferably 30% by mass or less, based on 100% by mass of the entire block copolymer.

[0086] 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, even more preferably 7,000 or more, particularly preferably 10,000 or more, preferably 40,000 or less, more preferably 35,000 or less, and even more preferably 30,000 or less. If the weight-average molecular weight is within the above range, the dispersion performance when used as a dispersant will be better.

[0087] The molecular weight distribution (Mw / Mn) of the block copolymer is preferably 2.5 or less, more preferably 2.0 or less, and even more preferably 1.6 or less. In this invention, the molecular weight distribution (Mw / Mn) is determined by (weight-average molecular weight of the block copolymer (Mw)) / (number-average molecular weight of the block copolymer (Mn)). The smaller the Mw / Mn, the narrower the molecular weight distribution, resulting in a copolymer with uniform molecular weights, and the narrowest molecular weight distribution is achieved when the value is 1.0. That is, the lower limit of Mw / Mn is 1.0. If the molecular weight distribution (Mw / Mn) of the block copolymer exceeds 2.5, it will contain molecules with both small and large molecular weights.

[0088] The amine value of the block copolymer is preferably 10 mg KOH / g or less, more preferably 1 mg KOH / g or less, and even more preferably 0.1 mg KOH / g or less. Preferably, the block copolymer has substantially no amine value (amine value is 0 mg KOH / g).

[0089] The acid value of the block copolymer is preferably 20 mg KOH / g or less, more preferably 10 mg KOH / g or less, and even more preferably 5 mg KOH / g or less. It is preferable that the block copolymer has substantially no acid value (an acid value of 0 mg KOH / g).

[0090] (Method of manufacturing block copolymers) Methods for producing block copolymers include: first producing block A by polymerization of vinyl monomers and then polymerizing the monomer of block B onto block A; first producing block B and then polymerizing the monomer of block A onto block B; and secondly producing block A and block B separately and then coupling block A and block B.

[0091] The polymerization method is not particularly limited, but living radical polymerization is preferred. That is, block copolymers polymerized by living radical polymerization are preferred. Living radical polymerization is preferred because it maintains the simplicity and versatility of conventional radical polymerization methods, while being less prone to termination reactions and chain transfer, and growing without being hindered by side reactions that deactivate the growth ends, thus facilitating precise control of molecular weight distribution and the production of polymers with a uniform composition.

[0092] Living radical polymerization methods include those using compounds capable of generating nitroxide radicals (nitroxide method; NMP method), which differ in the method of stabilizing the polymerization growth ends; those using metal complexes such as copper or ruthenium, with halogenated compounds as polymerization initiators and polymerization carried out in a living manner from those initiators (ATRP method); those using dithiocarboxylic acid esters or xantate compounds (RAFT method); those using organotellurium compounds (TERP method); those using organioidone compounds (ITP method); and those using iodine compounds as polymerization initiators and organic compounds such as phosphorus compounds, nitrogen compounds, oxygen compounds, or hydrocarbons as catalysts (reversible transfer catalytic polymerization; RTCP method, reversible catalyst-mediated polymerization; RCMP method). Among these methods, the TERP method is preferred from the viewpoint of the diversity of monomers that can be used, molecular weight control in the polymer range, uniform composition, and coloration.

[0093] The TERP method is a method for polymerizing radical polymerizable compounds (vinyl monomers) using an organotellurium compound as a chain transfer agent, and is described, for example, in International Publication Nos. 2004 / 14848, 2004 / 14962, 2004 / 072126, and 2004 / 096870.

[0094] Specific polymerization methods for the TERP method include the following (a) to (d). (a) A method for polymerizing vinyl monomers using an organotellurium compound represented by formula (6). (b) A method for polymerizing vinyl monomers using a mixture of an organic tellurium compound represented by formula (6) and an azo polymerization initiator. (c) A method of polymerizing vinyl monomer using a mixture of an organic tellurium compound represented by formula (6) and an organic diterlide compound represented by formula (7). (d) A method of polymerizing vinyl monomer using a mixture of an organic tellurium compound represented by formula (6), an azo polymerization initiator, and an organic diterlide compound represented by formula (7).

[0095] [ka] [In general formula (6), R 61 This represents an alkyl group, aryl group, or aromatic heterocyclic group having 1 to 8 carbon atoms. 62 and R 63 Each of these independently represents either a hydrogen atom or an alkyl group having 1 to 8 carbon atoms. 64 This 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 This represents an alkyl group, aryl group, or aromatic heterocyclic group having 1 to 8 carbon atoms.

[0096] Specific examples of organic tellurium compounds represented by general formula (6) include ethyl=2-methyl-2-n-butylteranyl-propionate, ethyl=2-n-butylteranyl-propionate, (2-hydroxyethyl)=2-methyl-methylteranyl-propionate, and other organic tellurium compounds described in International Publication Nos. 2004 / 14848, 2004 / 14962, 2004 / 072126, and 2004 / 096870. Specific examples of organic diterlide compounds represented by general formula (7) include dimethyl diterlide and dibutyl diterlide. Any azo polymerization initiator used in normal radical polymerization can be used without particular restrictions, such as 2,2'-azobis(isobutyronitrile) (AIBN), 2,2'-azobis(2,4-dimethylvaleronitrile) (ADVN), 1,1'-azobis(1-cyclohexanecarbonitride) (ACHN), and 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile) (V-70).

[0097] The polymerization step involves mixing a vinyl monomer, an organic tellurium compound of general formula (6), and, depending on the type of vinyl monomer, an azo polymerization initiator and / or an organic diterlide compound of general formula (7) in a container purged with an inert gas. Examples of inert gases used include nitrogen, argon, and helium. Argon and nitrogen are preferred. The amount of vinyl monomer used in (a), (b), (c), and (d) above may be adjusted as appropriate depending on the desired properties of the copolymer.

[0098] The polymerization reaction can be carried out without a solvent, but it may also be carried out using an aprotic or protic solvent commonly used in radical polymerization, while stirring the mixture. Examples of usable aprotic solvents include acetonitrile, methyl ethyl ketone, anisole, benzene, toluene, propylene glycol monomethyl ether acetate, ethyl acetate, tetrahydrofuran (THF), N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), N-methyl-2-pyrrolidone (NMP), acetone, dioxane, chloroform, carbon tetrachloride, and trifluoromethylbenzene. Examples of protic solvents include water, methanol, ethanol, isopropanol, n-butanol, ethyl cellosolve, butyl cellosolve, 1-methoxy-2-propanol, hexafluoroisopropanol, and diacetone alcohol. Solvents may be used individually or in combination of two or more. The amount of solvent used can be adjusted as appropriate; for example, 0.01 ml to 50 ml per 1 g of vinyl monomer is preferred. The reaction temperature and reaction time can be adjusted as appropriate depending on the molecular weight or molecular weight distribution of the resulting copolymer, but typically, stirring is performed at 0°C to 150°C for 1 minute to 100 hours. After the polymerization reaction is complete, the target copolymer can be separated from the reaction mixture by removing the solvent used, residual vinyl monomer, etc., using conventional separation and purification methods.

[0099] The growth ends of the copolymer obtained by the polymerization reaction are derived from the tellurium compound -TeR 61 (In the formula, R61 The form is the same as described above, and although it is deactivated by handling in air after the polymerization reaction is complete, tellurium atoms may remain. Copolymers with tellurium atoms remaining at the ends may be discolored or have poor thermal stability, so it is preferable to remove the tellurium atoms. Methods for removing tellurium atoms include radical reduction methods; adsorption methods using activated carbon, etc.; and adsorption methods using ion exchange resins, etc. These methods can also be used in combination. The other end of the copolymer obtained by the polymerization reaction (the end opposite to the growth end) is -CR derived from the tellurium compound. 62 R 63 R 64 (In the formula, R 62 , R 63 and R 64 R in equation (6) 62 , R 63 and R 64 It is the same as (the same as).

[0100] <Dispersant> The dispersant of the present invention contains the 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 solely of the block copolymer.

[0101] Furthermore, the dispersant exhibits particularly high dispersion performance with respect to carbon black, a black coloring agent, and can suppress aggregation. In addition, the dispersant also exhibits excellent dispersion performance with respect to carbon particles such as carbon nanotubes and graphene, similar to carbon black. Therefore, the dispersant of the present invention can be suitably used as a dispersant for carbon particles and can also be used in conductive compositions.

[0102] The dispersant is prepared as a dispersant solution before the preparation of the colored composition, which facilitates the dispersion of the coloring agent. The solvent used in the dispersant solution is preferably one that can dissolve the dispersant, does not react with these components, and is moderately volatile. Examples of solvents include the dispersion media used in the colored composition described later. The solvent content in the dispersant solution is not particularly limited and can be adjusted as appropriate. The upper limit of the solvent content in the dispersant solution is usually 99% by mass. The lower limit of the dispersion media content in the dispersant solution is usually 10% by mass, and preferably 30% by mass, considering the viscosity suitable for the production of the colored composition described later.

[0103] <Coloring composition> The colored composition of the present invention contains a dispersant (block copolymer), a coloring agent, and an aqueous dispersion medium.

[0104] (Coloring material) The coloring agent is not particularly limited, and pigments and dyes conventionally used as coloring agents for paints can be used, but pigments are preferred from the viewpoint of lightfastness and heat resistance. Examples of pigments include red pigments, yellow pigments, orange pigments, blue pigments, green pigments, purple pigments, black pigments, and other pigments of various colors. Examples of pigment structures include organic pigments such as azo pigments such as monoazo pigments, diazo pigments, and condensed diazo pigments; diketopyrrolopyrrole pigments, phthalocyanine pigments, isoindolinone pigments, isoindoline pigments, quinacridone pigments, indigo pigments, thioindigo pigments, quinophthalone pigments, dioxazine pigments, anthraquinone pigments, perylene pigments, and perinone pigments; and inorganic pigments such as carbon black, graphene, carbon nanotubes, graphite, titanium black, and metal oxides, composite oxides, metal sulfides, metal sulfates, and metal carbonates of copper, iron, manganese, cobalt, chromium, nickel, zinc, calcium, silver, etc. The coloring composition may contain only one type of pigment or multiple types of pigments.

[0105] Since the block copolymer exhibits particularly excellent dispersion performance for black pigments and blue pigments, it is preferable that the coloring agent be at least one selected from the group consisting of black pigments and blue pigments.

[0106] Examples of black pigments include carbon black such as furnace black, channel black, acetylene black, thermal black, lamp black, and bone black; graphene; carbon nanotubes such as single-walled carbon nanotubes and multi-walled carbon nanotubes; carbon nanofibers such as vapor-grown carbon nanofibers; 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; composite oxides; metal sulfides; metal sulfates; and metal carbonates. Among these, at least one type of carbon particle selected from the group consisting of carbon black, graphene, carbon nanotubes, and carbon nanofibers is preferred, and more preferably at least one type of carbon particle selected from the group consisting of carbon black and carbon nanotubes.

[0107] The primary particle size of the carbon particles is not particularly limited, but 5 nm to 100 nm is preferred. The specific surface area of ​​carbon particles is 300 m². 2 / g~1300m 2 / g is preferred, and more preferably 400m 2 / g~800m 2 The value is / g. The specific surface area is measured according to JIS K 6217-3(2001).

[0108] The amount of DBP (dibutyl phthalate) absorbed by carbon particles is preferably 50 ml / 100g to 150 ml / 100g, and more preferably 80 ml / 100g to 120 ml / 100g. The amount of DBP absorbed is measured according to JIS K 6217-4 (2017).

[0109] Carbon particles may have their surface oxidized. Oxidation can impart carboxyl groups or phenolic hydroxyl groups to the surface of the carbon particles. Oxidation can be performed by treating the surface of the carbon particles with ozone, nitric acid, etc. Carbon particles with carboxyl groups or phenolic hydroxyl groups on their surface will have an acidic pH.

[0110] The carbon particles are preferably dispersed in 100 ml of water (25°C) and the pH of the dispersion is 3 to 9, more preferably 5 to 9.

[0111] Examples of blue pigments include organic pigments mainly composed of organic compounds such as phthalocyanine pigments, anthraquinone pigments, and dioxazine pigments, and these can be used individually or in mixtures of two or more. Among these, phthalocyanine pigments are preferred, and metal phthalocyanine pigments and monohalide metal phthalocyanine pigments (halide metal phthalocyanine pigments having one halogen atom in the molecule) are more preferred. Note that polyhalide metal phthalocyanine pigments (halide metal phthalocyanine pigments having two or more halogen atoms in the molecule) are green pigments, and therefore polyhalide metal phthalocyanine pigments are not included in the phthalocyanine pigments used as blue pigments.

[0112] As phthalocyanine pigments, compounds represented by general formula (8) are particularly preferred. Copper phthalocyanine pigments and monohalogenated copper phthalocyanine pigments have a transmittance region in the short wavelength range, and therefore can form a colored layer with higher brightness.

[0113] [ka] [In equation (8), R 8 Each of these independently represents a hydrogen atom or a halogen atom. However, R 8 The number of halogen atoms inside is either 0 or 1.

[0114] R8 It is preferable that all of the atoms are hydrogen atoms, as they transmit light in the short wavelength region well and make it easier to obtain the effects of the present invention.

[0115] Specifically, compounds classified as pigments in the Color Index (CI) as blue pigments include CIPigment 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, 78, 79, 80, etc. Preferred phthalocyanine pigments are CIPigment Blue 15, 15:1, 15:2, 15:3, 15:4, 15:6, 16, 17, 17:1, and 75. Preferred copper phthalocyanine pigments and monohalogenated copper phthalocyanine pigments are CIPigment Blue 15, 15:1, 15:2, 15:3, 15:4, 15:6, 16, 17, and 17:1. Preferred anthraquinone pigment is CIPigment Blue 60. Preferred dioxazine pigment is CIPigment Blue 80.

[0116] The number-average particle size of the pigment can be appropriately selected according to its application and is not particularly limited. From the viewpoint of high brightness, the coloring composition preferably contains pigments with a number-average particle size of 10 nm to 150 nm.

[0117] The pigment may contain a pigment derivative as a dispersion aid. This pigment derivative has a functional group introduced into its pigment skeleton. The pigment skeleton is preferably the same as or similar to the pigment constituting the coloring composition, or the same as or similar to the compound that is the raw material for the pigment. Specific examples of pigment skeletons include azo pigment skeletons, phthalocyanine pigment skeletons, anthraquinone pigment skeletons, triazine pigment skeletons, acridine pigment skeletons, perylene pigment skeletons, and the like.

[0118] There are no particular limitations on the amount of dye derivative used, but it is preferably 4 to 17 parts by mass per 100 parts by mass of pigment.

[0119] From the viewpoint of brightness, the upper limit of the coloring agent content in the colored composition is usually 80% by mass, preferably 70% by mass, and more preferably 60% by mass, relative to the total solid content of the colored composition. The lower limit of the coloring agent content in the colored composition is usually 3% by mass, preferably 20% by mass, and more preferably 30% by mass, relative to the total solid content of the colored composition. Here, solid content refers to components other than the dispersion medium described later.

[0120] The amount of dispersant in the coloring composition relative to the coloring agent is preferably 5 to 200 parts by mass, preferably 10 to 100 parts by mass, and more preferably 10 to 80 parts by mass, per 100 parts by mass of the coloring agent.

[0121] (aqueous dispersion medium) Examples of aqueous dispersion media include water or aqueous solvents (solvents miscible with water). Specifically, examples include alcohols such as methanol, ethanol, propanol, isopropyl alcohol, butanol, 1-methoxy-2-propanol, 1-butoxy-2-propanol, and propylene glycol-n-butyl ether; polyhydric alcohols such as ethylene glycol, propylene glycol, butylene glycol, triethylene glycol, diethylene glycol, polyethylene glycol, polypropylene glycol, and glycerin; ethers such as tetrahydrofuran, dioxane, ethylene glycol methyl ether, ethylene glycol ethyl ether, diethylene glycol methyl ether, diethylene glycol ethyl ether, triethylene glycol, monomethyl ether, and monoethyl ether; ketones such as acetone, methyl ethyl ketone, and isobutyl ketone; and amides such as dimethylformaldehyde and dimethylacetamide. Among these, alcohols and glycols are preferred. Aqueous solvents may be used alone or in combination of two or more.

[0122] The content of aqueous dispersion medium in the coloring composition is not particularly limited and can be adjusted as appropriate. The upper limit of the content of aqueous dispersion medium in the coloring composition is usually 99% by mass. The lower limit of the content of aqueous dispersion medium in the coloring composition is usually 60% by mass, and preferably 80% by mass, taking into consideration the viscosity suitable for application of the coloring composition.

[0123] Depending on the application, the colored composition may further contain additives such as film-forming resins, surfactants, leveling agents, fillers, UV absorbers, antioxidants, preservatives, fungicides, viscosity modifiers, pH adjusters, defoamers, and crosslinking agents. Furthermore, if conductive carbon particles (carbon black, carbon nanotubes, graphene, carbon nanofibers, etc.) are used in the colored composition, it can be used as an electrode. In this case, the colored composition may also contain additives such as electrode-forming resins, electrode active materials, surfactants, film-forming aids, leveling agents, preservatives, fungicides, viscosity modifiers, pH adjusters, defoamers, and crosslinking agents.

[0124] (Resin for coating film formation) The film-forming resin is the main component of the film formed when a coating is created using a colored composition. The film-forming resin is not particularly limited, and any resin conventionally used in paints can be used. Examples of film-forming resins include thermosetting resins, thermoplastic resins, polymerizable compounds (polymerizable resins, monomers having one polymerizable unsaturated bond in the molecule, monomers having two or more polymerizable unsaturated bonds in the molecule, oligomers, etc.). The film-forming resin can be used alone or in a mixture of two or more types. When the film-forming resin is incorporated into the colored composition, the content of the film-forming resin is preferably 60% to 95% by mass of the total solid content of the colored composition.

[0125] (thermosetting resin, thermoplastic resin) Examples of thermosetting resins and thermoplastic resins include 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, cycloplastic rubber, epoxy resin, cellulose, polybutadiene, polyimide resin, benzoguanamine resin, melamine resin, urea resin, silicone resin, and fluororesin.

[0126] (polymerizable compound) Polymerizable resins used as polymerizable compounds include linear polymers having reactive substituents such as hydroxyl groups, carboxyl groups, and amino groups, to which crosslinkable groups such as (meth)acrylic compounds and cinnamic acid are introduced via isocyanate groups, aldehyde groups, epoxy groups, etc. Polymers are also used in which linear polymers containing acid anhydrides such as styrene-maleic anhydride copolymers and α-olefin-maleic anhydride copolymers are half-esterified with (meth)acrylic compounds having hydroxyl groups such as hydroxyalkyl (meth)acrylates.

[0127] (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. Examples of anionic surfactants include alkyl sulfonates, alkylbenzene sulfonates, alkylnaphthalene sulfonates, polyoxyethylene alkyl ether sulfonates, alkyl sulfates, alkyl sulfate esters, higher alcohol sulfate esters, aliphatic alcohol sulfate esters, polyoxyethylene alkyl ether sulfates, polyoxyethylene alkylphenyl ether sulfates, alkyl phosphate esters, polyoxyethylene alkyl ether phosphates, polyoxyethylene alkylphenyl ether phosphates, and special polymer surfactants. 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.

[0128] (Leveling agent) Examples of leveling agents include silicone-based and fluorine-based agents. Silicone-based agents 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. Fluorine-based agents include fluorocarbon compounds and fluorosilicone. These can be used individually or in combination of two or more.

[0129] (filling material) Examples of fillers include silicon dioxide, alumina, zinc oxide, potassium titanate fibers, aluminum flakes, stainless steel powder, tin powder, gold powder, metal-plated glass powder, titanium mica, calcium carbonate, barium sulfate, barium carbonate, kaolin, barita, clay, and other metal oxides and composite metal oxides. These can be used individually or in mixtures of two or more to prevent viscosity reduction and poor gloss.

[0130] (Electrode-forming resin) Electrode-forming resins are used to bond particles of active materials or conductive carbon materials to each other, or to bond conductive carbon particles to a current collector. Examples of electrode-forming resins include acrylic resins, polyurethane resins, polyester resins, phenolic resins, epoxy resins, phenoxy resins, urea resins, melamine resins, alkyd resins, formaldehyde resins, silicone resins, fluororesins, cellulose resins such as carboxymethylcellulose, synthetic rubbers such as styrene-butadiene rubber and fluororubber, conductive resins such as polyaniline and polyacetylene, and polymer compounds containing fluorine atoms such as polyvinylidene fluoride, polyvinyl fluoride, and tetrafluoroethylene. Modified products, mixtures, or copolymers of these resins can also be used. These resins can be used individually or in combination.

[0131] <Method for producing colored composition> The colored composition can be prepared by mixing a colorant, a dispersant (block copolymer), an aqueous dispersion medium, and, if necessary, a coating resin, an electrode-forming resin, and other compounding agents. Mixing can be performed using a mixing and dispersing machine such as a paint shaker, bead mill, ball mill, dissolver, or kneader. It is preferable to filter the colored composition after mixing. Examples of colored compositions include automotive paint compositions and electrode-forming compositions. The electrode-forming composition contains conductive carbon particles as a colorant.

[0132] The colored composition can be applied (painted) to a workpiece such as a stainless steel plate or an aluminum plate by methods such as roll coating, spin coating, flow coating, slot die coating, spray coating, dipping, electrodeposition coating, electrostatic coating, brush coating, or powder coating. Afterwards, the solvent is evaporated by heating as necessary, and the coating film is dried and cured. Heating or irradiation with ultraviolet light may be used at this time. The coating film obtained by applying the colored composition may be further coated with one or more layers of top clear paint to form a top clear coating film. The top clear paint is a liquid paint that forms a colorless or colored transparent coating film, mainly composed of resin components and solvents, and further blended with other paint additives as necessary. [Examples]

[0133] The present invention will be described in more detail below based on specific examples. The present invention is not limited in any way to the following examples, and can be implemented with appropriate modifications without changing its essence. The polymerization rate, weight-average molecular weight (Mw), molecular weight distribution (Mw / Mn), amine value, and coating film properties of the block copolymer were evaluated according to the method described below.

[0134] The meanings of the abbreviations are as follows: BTEE: Ethyl 2-methyl-2-n-butylteranyl 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

[0135] (Polymerization rate) Using a nuclear magnetic resonance (NMR) spectroscopy system (Bruker BioSpin, model: AVANCE500 (frequency 500MHz)), 1 ¹H-NMR was measured (solvent: CDCl3, internal standard: TMS). The integral ratio of the monomer-derived peaks and polymer-derived peaks in the obtained NMR spectrum was determined to calculate the polymerization rate of the monomer.

[0136] (Weight-average molecular weight (Mw) and molecular weight distribution (Mw / Mn)) The molecular weight was determined by gel permeation chromatography (GPC) using a high-performance liquid chromatograph (Tosoh, model HLC-8320). One SHODEX KF-603 column (φ6mm × 150mm) (SHODEX) was used, with a lithium bromide (10 mmol / L)-acetic acid (10 mmol / L)-methylpyrrolidone solution as the mobile phase and a differential refractometer as the detector. The measurement conditions were a column temperature of 40°C, a sample concentration of 20 mg / mL, a sample injection volume of 10 μm, and a flow rate of 0.2 mL / min. Calibration curves were created using polystyrene (molecular weights 70,500, 37,900, 19,920, 10,200, 4,290, 2,630, 1,150) as standard substances, and the weight-average molecular weight (Mw) and number-average molecular weight (Mn) were measured. The molecular weight distribution (Mw / Mn) was calculated from these measurements.

[0137] (Amine value) The amine value represents the mass of potassium hydroxide (KOH) equivalent to the basic component per gram of solid content. The sample was dissolved in tetrahydrofuran, and the resulting solution was titrated with hydrochloric acid (0.1 mol / L)-propanol solution using a potentiometric titrator (product name: GT-06, manufactured by Mitsubishi Chemical). The amine value (B) was calculated using the following formula, with the inflection point of the titration pH curve as the titration endpoint. B = 56.11 × Vs × 0.1 × f / w B: Amine value (mgKOH / g) Vs: Volume (mL) of hydrochloric acid (0.1 mol / L)-propanol solution required for titration f: Titer of hydrochloric acid (0.1 mol / L)-propanol solution w: Mass (g) of the measurement sample (in terms of solid content)

[0138] (Black evaluation) The black paint was applied to a stainless steel plate using a bar coater (#20) and dried at 60°C for 10 minutes to form a coating film, and test pieces were prepared. For the coating film forming surface of the obtained test pieces, the L value was measured using an L value measuring instrument (manufactured by Konica Minolta Japan, model CM-2600d) with removal of specular reflection light. The evaluation was performed on the black paint immediately after preparation and the black paint after standing at 35°C for 3 weeks after adjustment.

[0139] (Blue evaluation) The blue paint (primary color) was applied to a 100 μm transparent film using a 52 μm bar, pre-dried at 60°C, and dried at 140°C for 10 minutes to form a coating film, and test pieces were prepared. For the coating film forming surface of the obtained test pieces, the haze was measured using a haze meter (manufactured by Nippon Denshoku, model NDH-5000). The evaluation was performed on the blue paint (primary color) immediately after preparation and the blue paint (primary color) after storing at 35°C for 3 weeks after preparation. Also, the blue paint (aluminum split paint) was applied to a 100 μm transparent film using a 52 μm bar, pre-dried at 60°C, and dried at 140°C for 10 minutes to form a coating film, and test pieces were prepared. For the coating film forming surface of the obtained test pieces, measurement was performed using a spectrophotometer (manufactured by Konica Minolta Japan, model CM-2600d), and the chroma was calculated as C = (a 2 + b 2 ) 1 / 2 More calculated.

[0140] (Microscopic observation) The black paint was applied to a stainless steel plate using a bar coater (#20) and dried at 60°C for 10 minutes to form a coating film, and test pieces were prepared. The coating surface of the obtained test specimens was observed using a microscope, and those that did not show aggregation were evaluated as "○" and those that did show aggregation were evaluated as "×".

[0141] <Synthesis of block copolymers> (Block copolymer No. 1) In a flask equipped with an argon gas inlet tube and a stirrer, 9.0g of BA, 18.0g of M11EGA, 0.05g of AIBN, and 6.7g of PMA were charged. After purging with nitrogen, 0.45g of BTEE was added, and the mixture was reacted at 60°C for 13 hours to polymerize block A. The polymerization rate was 99%.

[0142] A mixed solution of 8.0 g of VP, 0.05 g of AIBN, and 8.3 g of PMA, pre-purged with argon, was added to the reaction solution, and the reaction was carried out at 60°C for 35 hours to polymerize block B. The polymerization rate was 100%.

[0143] After the reaction was complete, the reaction solution was poured into a stirred n-heptane solution. The precipitated polymer was filtered by suction and dried to obtain block copolymer No. 1. The obtained block copolymer No. 1 had an Mw of 22,571 and an Mw / Mn ratio of 1.22.

[0144] (Block copolymer No. 2-9) Block copolymers No. 2 to 9 were prepared in the same manner as block copolymer No. 1. Table 1 shows the monomers, organotellurium compounds, azo polymerization initiators, solvents, reaction conditions, and polymerization rates used. Table 2 shows the composition, Mw, Mw / Mn, and amine value of each block copolymer. The content of each structural unit in the copolymer was calculated from the charge ratio and polymerization rate of the monomers used in the polymerization reaction.

[0145] [Table 1]

[0146] [Table 2]

[0147] (Black paint No. 1-9) Black paints were prepared using block copolymers No. 1-9 obtained above as dispersants. Specifically, each component was added to a 50 mL mayonnaise bottle according to the formulation shown in Table 3, and then 66 g of zirconia beads (φ0.3 mm) were added. The mixture was then stirred for 5 hours using a disperser (Owell, SKANDEX DISPERSER BA-S20). After stirring, the beads were filtered off to obtain a pigment dispersion. Black paints No. 1-9 were prepared by mixing the obtained pigment dispersion with clear paint. The dispersibility of carbon black in the obtained black paints No. 1-9 was visually confirmed.

[0148] [Table 3] Black pigment 1: Product name "EMPEROR(registered trademark) 2000", manufactured by Cabot Corporation, carbon black, pH 6-9 Antifoaming agent: Product name "BYK-024", manufactured by Big Chemie, silicone-based surfactant. Acrylic resin: Product name "Watersol (registered trademark) ACD-2001", manufactured by DIC, non-volatile content: 40% by mass, solvent: water, propylene glycol-n-butyl ether Melamine resin: Product name "Cymel (registered trademark) 303LF", manufactured by allnex, methylated melamine resin, non-volatile content; 100% by mass

[0149] (Blue paint No.1~9) Blue paints (primary colors, aluminum-based paints) were prepared using block copolymers No. 1-9 obtained above as dispersants. Specifically, each component was added to a 50 mL mayonnaise bottle according to the formulation shown in Table 4, and 66 g of zirconia beads (φ0.3 mm) were added. The mixture was then stirred for 5 hours using a disperser (Owell, SKANDEX DISPERSER BA-S20). After stirring, the beads were filtered off to obtain a pigment dispersion. Blue paints No. 1-9 (primary colors, aluminum-based paints) were prepared by mixing the obtained pigment dispersion with clear paint, or with the primary aluminum color. The dispersibility of the blue pigment in the obtained blue paints No. 1-9 (primary colors, aluminum-based paints) was visually confirmed to be good.

[0150] [Table 4] Blue pigment: Product name "CYANINE Blue G-314R", manufactured by Sanyo Shikkei, chlorinated copper phthalocyanine pigment (CIPigment Blue 15:1) Antifoaming agent: Product name "BYK-024", manufactured by Big Chemie, silicone-based surfactant. Acrylic resin: Product name "Watersol (registered trademark) ACD-2001", manufactured by DIC, non-volatile content: 40% by mass, solvent: water, propylene glycol-n-butyl ether Melamine resin: Product name "Cymel (registered trademark) 303LF", manufactured by allnex, methylated melamine resin, non-volatile content; 100% by mass Water-based aluminum: Product name "STAPA IL HYDROLAN S 412", manufactured by ECKART, aluminum paste.

[0151] (Black paint No. 10) A black paint was prepared using block copolymer No. 1 obtained above as a dispersant. Specifically, each component was added to a 50 mL mayonnaise bottle according to the formulation shown in Table 5, and then 66 g of zirconia beads (φ0.3 mm) were added. The mixture was then stirred for 5 hours using a disperser (Owell, SKANDEX DISPERSER BA-S20). After stirring, the beads were filtered off to prepare black paint No. 10. The dispersibility of carbon nanotubes in the obtained black paint No. 10 was visually confirmed to be good.

[0152] [Table 5] Black pigment 2: Product name "Nanocyl7000", manufactured by NANOCOYL, multi-walled carbon nanotube Antifoaming agent: Product name "BYK-024", manufactured by Big Chemie, silicone-based surfactant.

[0153] Block copolymers 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). Black paints using these block copolymers No. 1 to 8 had low L values ​​in the coating film prepared immediately after preparation. Similarly, coating films formed from blue paints (primary colors) using these block copolymers No. 1 to 8 had low haze values ​​in the coating film prepared immediately after preparation. Therefore, these block copolymers No. 1 to 8 have high dispersion performance for both black and blue colorants.

[0154] Furthermore, the black paints using block copolymers No. 1-5 also showed low L values ​​in the paint films prepared after 3 weeks of storage from preparation. The blue paints (primary colors) using block copolymers No. 1-5 also showed low haze values ​​and high saturation in the paint films formed after 3 weeks of storage from preparation.

[0155] Furthermore, black paint No. 10, prepared using block copolymer No. 1, also exhibited excellent carbon nanotube (carbon particle) dispersion performance. Since block copolymers No. 2-8 have a similar structure to block copolymer No. 1, it is expected that these block copolymers No. 2-8 also possess high carbon nanotube (carbon particle) dispersion performance.

[0156] Block copolymer No. 9 is the case where there is no B block containing the structural unit represented by formula (3). The black paint using this block copolymer No. 9 had a high L value in the prepared coating film, both immediately after preparation and after 3 weeks of storage. Furthermore, the blue paint (primary color) using this block copolymer No. 9 had a relatively low haze value in the coating film prepared immediately after preparation, but a high haze value in the coating film prepared after 3 weeks of storage. In addition, the saturation of the coating film formed from the blue paint (aluminum-split paint) using block copolymer No. 9 was low.

[0157] The present invention includes the following embodiments.

[0158] (Aspect 1) A block copolymer characterized by having block A containing a structural unit represented by formula (1) and block B containing a structural unit represented by formula (3).

[0159] [ka] [In equation (1), n1 represents an integer between 2 and 30. R 11 R represents a hydrogen atom or an alkyl group with 1 to 3 carbon atoms. 12 R represents an alkylene group with 1 to 3 carbon atoms. 13 R represents a hydrogen atom or a methyl group. Note that there are multiple R's. 12 These may be the same or different.

[0160] [ka] [In equation (3), R 31, R 32 , R 33 and R 34 are the same or different and each represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms which may have a substituent. m3 represents an integer of 0 to 4. n3 represents an integer of 1 to 3.]

[0161] (Aspect 2) The block copolymer according to Aspect 1, 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.

[0162] (Aspect 3) The block copolymer according to Aspect 1 or 2, 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.

[0163] (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 the B block in the block copolymer is 50 / 50 to 95 / 5.

[0164] (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 the formula (2).

[0165] [Chemical formula] [In the formula (2), R 21 represents a linear or cyclic hydrocarbon group which may have a substituent. R 22 represents a hydrogen atom or a methyl group.]<0​​​​The block copolymer according to any one of embodiments 1 to 5, wherein the B block further comprises at least one structural unit selected from the group consisting of structural units derived from (meth)acrylate having a cyclic ether group, structural units derived from (meth)acrylate having an aromatic group, and structural units derived from (meth)acrylate having a monocyclic cyclic alkyl group.

[0167] (Aspect 7) The block copolymer according to any one of embodiments 1 to 6, wherein the molecular weight distribution (Mw / Mn) of the block copolymer is 2.5 or less.

[0168] (Pattern 8) The block copolymer according to any one of embodiments 1 to 7, wherein the weight-average molecular weight (Mw) of the block copolymer is 3,000 to 40,000.

[0169] (Aspect 9) The block copolymer according to any one of embodiments 1 to 8, wherein the block copolymer is polymerized by living radical polymerization.

[0170] (Aspect 10) A dispersant characterized by containing a block copolymer as described in any one of embodiments 1 to 9.

[0171] (Aspect 11) A colored composition characterized by containing the dispersant, colorant, and aqueous dispersion medium described in Embodiment 10.

[0172] (Aspect 12) The coloring composition according to embodiment 11, wherein the coloring agent is at least one selected from the group consisting of carbon particles and phthalocyanine-based pigments.

[0173] (Aspect 13) The coloring composition according to embodiment 12 further contains at least one selected from the group consisting of a coating film-forming resin and an electrode-forming resin.

[0174] (Aspect 14) The coloring composition according to embodiment 12 or 13, which is an automotive paint composition or an electrode forming composition.

[0175] (Aspect 15) A coating film characterized by being formed from a colored composition described in any one of embodiments 11 to 14. [Industrial applicability]

[0176] The block copolymer of the present invention can be used as a dispersant in a colored composition containing a coloring agent and an aqueous dispersion medium, and is particularly useful as a dispersant for carbon particles. The colored composition of the present invention is useful for automotive paints and the like because the resulting coating film is jet black.

Claims

1. It comprises Block A containing a structural unit represented by formula (1) and Block B containing a structural unit represented by formula (3), In 100% by mass of block A, the content of structural units represented by formula (1) is 20% by mass to 95% by mass, and the content of structural units represented by formula (3) is 3% by mass or less. A block copolymer characterized in that, in 100% by mass of block B, the content of structural units represented by formula (3) is 50% to 100% by mass, and the content of structural units represented by formula (1) is 10% by mass or less. 【Chemistry 1】 [In equation (1), n1 represents an integer between 2 and 30. R 11 R represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. 12 R represents an alkylene group with 1 to 3 carbon atoms. 13 R represents a hydrogen atom or a methyl group. Note that there are multiple R's. 12 These may be the same or different. 【Chemistry 2】 [In equation (3), R 31 , R 32 , R 33 and R 34 [ represents an alkyl group having 1 to 10 carbon atoms, which may have a hydrogen atom or substituents, and may be identical or different. m3 represents an integer from 0 to 4. n3 represents an integer from 1 to 3.]

2. The block copolymer according to claim 1, wherein the mass ratio of block A to block B (block A / block B) in the block copolymer is 50 / 50 to 95 / 5.

3. The block copolymer according to claim 1 or 2, wherein the block A further contains a structural unit represented by formula (2). 【Transformation 3】 [In formula (2), R 21 represents a linear or cyclic hydrocarbon group which may have a substituent. R 22 represents a hydrogen atom or a methyl group. ]

4. The block copolymer according to claim 3, wherein the content of the structural unit represented by formula (2) is 5% by mass to 80% by mass in 100% by mass of the A block.

5. The block copolymer according to any one of claims 1 to 4, wherein the B block further comprises at least one structural unit selected from the group consisting of structural units derived from (meth)acrylate having a cyclic ether group, structural units derived from (meth)acrylate having an aromatic group, and structural units derived from (meth)acrylate having a monocyclic cyclic alkyl group.

6. In 100% by mass of the entire block copolymer, The content of block A is 50% by mass to 95% by mass, The block copolymer according to any one of claims 1 to 5, wherein the content of the B block is 5% by mass to 50% by mass.

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

8. The block copolymer according to any one of claims 1 to 7, wherein the weight-average molecular weight (Mw) of the block copolymer is 3,000 to 40,000.

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

10. A dispersant characterized by containing a block copolymer according to any one of claims 1 to 9.

11. A colored composition characterized by containing the dispersant, colorant, and aqueous dispersion medium described in claim 10.

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

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

14. The coloring composition according to claim 12 or 13, which is an automotive paint composition or an electrode forming composition.

15. A coating film characterized by being formed from a colored composition according to any one of claims 11 to 14.

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