Ink resins, inks, ink sets, and printed materials

Abstract

The present invention aims to provide an ink resin that enables the production of water-based inks and ink sets that exhibit excellent redispersibility and storage stability, have few coarse particles, and exhibit excellent durability even when printed on non-absorbent substrates. [Solution] The ink resin of the present invention is an ink resin of a polymer represented by the following general formula (1), wherein block A contains acidic group-containing monomer units, and block B contains one or more selected from the group consisting of aromatic ring-containing monomer units, aliphatic ring-containing monomer units, (meth)acrylate alkyl ester units, and crosslinkable monomer units. General formula (1) [Formula 1] JPEG2026064330000023.jpg2354

Description

Technical Field

[0001] The present invention relates to a resin for ink used in aqueous ink and the like.

Background Art

[0002] Aqueous inkjet inks have been developed for printing on dedicated papers such as plain paper and photo gloss paper. In recent years, there has been an increasing need to directly print on coated papers such as coated paper and art paper, or plastic films such as polyvinyl chloride, PET, polypropylene (PP), and polyethylene (PE), rather than dedicated papers. However, such non-absorbent substrates or non-absorbent substrates have low friction resistance, water resistance, solvent resistance, etc. because the ink does not penetrate into the substrate and the printed layer is exposed on the surface, and the durability of printed matter has become an issue.

[0003] Therefore, developments have been made to improve the durability of printed matter. For example, Patent Document 1 discloses an inkjet aqueous ink containing water, a water-soluble organic solvent, vinyl polymer particles containing a pigment, and polycarbonate-based urethane resin particles, characterized in that the water-soluble organic solvent consists only of a water-soluble organic solvent having a boiling point of 250°C or lower. Patent Document 2 discloses an inkjet aqueous ink containing an ABC triblock polymer having specific structural units and a resin emulsion, respectively. Patent Document 3 discloses an inkjet ink containing a water-insoluble colorant, a dispersant, a fixing resin, and water, wherein the fixing resin contains, as constituent monomer units, a (meth)acrylic acid C1-C4 alkyl unit and a styrene sulfonic acid unit, and at least a butyl acrylate unit as the (meth)acrylic acid C1-C4 alkyl unit, and the content of the butyl acrylate unit in the fixing resin exceeds 31.5% by mass and is less than 46.5% by mass, and the content of the styrene sulfonic acid unit is 0.1% by mass or more and less than 3.0% by mass.

Prior Art Documents

Patent Documents

[0004] [Patent Document 1] Japanese Patent Publication No. 2015-14919 [Patent Document 2] Japanese Patent Publication No. 2012-72354 [Patent Document 3] International Publication No. 2024 / 034369 [Disclosure of the Invention] [Problems that the invention aims to solve]

[0005] Conventional inkjet inks improved the durability of printed materials using non-absorbent substrates by improving the resin. However, they had a problem in that they could not achieve both improved durability and good redispersibility, as the ink was difficult to redisperse after it had solidified and prone to ink ejection failure.

[0006] The present invention aims to provide an ink resin that can form water-based inkjet inks with excellent redispersibility and high durability for printed materials using non-absorbent substrates. [Means for solving the problem]

[0007] One embodiment of the present invention is that the ink resin is a polymer represented by the following general formula (1), The aforementioned Block A contains an acidic group-containing monomer unit, The aforementioned Block B is an ink resin containing one or more units selected from the group consisting of aromatic ring-containing monomer units, aliphatic ring-containing monomer units, (meth)acrylate alkyl ester units, and crosslinkable monomer units. General formula (1) [ka]

[0008] [In general formula (1), Polymer represents an AB block polymer, and a portion of the AB block polymer may be substituted with a functional group. Z represents an organic group selected from alkyl groups, aryl groups, arylalkyl groups, alkylthio groups, arylthio groups, and arylalkylthio groups, and a portion of the organic group may be substituted.]

[0009] Another embodiment of the present invention is a polymer represented by the following general formula (2): The aforementioned polymer is an AB block polymer, The aforementioned Block A contains an acidic group-containing monomer unit, The aforementioned B block is an ink resin comprising one or more units selected from the group consisting of aromatic ring-containing monomer units, aliphatic ring-containing monomer units, (meth)acrylate alkyl ester units, and crosslinkable monomer units. General formula (2) [ka] [In general formula (2), Polymer represents an AB block polymer, and a portion of the AB block polymer may be substituted with a functional group. Z represents an organic group selected from alkyl groups, aryl groups, arylalkyl groups, alkylthio groups, arylthio groups, and arylalkylthio groups, and a portion of the organic group may be substituted. R 1 [wherein -1 represents an organic group, the organic group having an acid group selected from -CO2H and -SO3H, which are neutralized by a basic compound.] [Effects of the Invention]

[0010] According to the present invention described above, it is possible to provide an ink resin that can form an aqueous inkjet ink with excellent redispersibility and high durability of printed materials using a non-absorbent substrate. Furthermore, the present invention can provide an ink, an ink set, and a printed material. [Modes for carrying out the invention]

[0011] First, we define the terms used in this specification. "C.I." means Color Index (C.I.). A monomer (hereinafter also referred to as a monomer) is an ethylenically unsaturated group-containing monomer and is a compound before polymerization. A monomer is a compound before polymerization, and a monomer unit is a partial structure in which a monomer polymerizes to form a polymer. A dispersion resin is a compound used for dispersing a colorant. The molecular weight dispersity is a value obtained by dividing the weight average molecular weight by the number average molecular weight. The weight average molecular weight (Mw) and the number average molecular weight (Mn) can be measured, for example, using a TSK-GEL SUPER HZM-N column (manufactured by Tosoh Corporation), at a column temperature of 40 °C, with a GPC equipped with a RI detector (manufactured by Tosoh Corporation, HLC-8320GPC), using tetrahydrofuran as the eluent solvent under the condition of a flow rate of 0.35 mL / min.

[0012] The resin for ink of the present invention is a polymer represented by the following general formula (1), The A block contains an acidic group-containing monomer unit, The B block contains one or more selected from the group consisting of an aromatic ring-containing monomer unit, an aliphatic ring-containing monomer unit, a (meth)acrylic acid alkyl ester unit, and a crosslinkable monomer unit, and is a resin for ink. General formula (1)

Chemical formula

[0013] In general formula (1), Polymer represents an A-B block polymer, and a part of the A-B block polymer may be substituted with a functional group. Z represents an organic group selected from an alkyl group, an aryl group, an arylalkyl group, an alkylthio group, an arylthio group, and an arylalkylthio group, and a part of the organic group may be substituted.

[0014] The free end of the polymer may have a substituent R. The substituent R represents an organic group derived from the RAFT agent rather than from the monomer. The organic group is not limited and includes, for example, an organic group in which a linear or branched monovalent alkyl group of C1 to C10 forms the basic skeleton, and one or more hydrogen atoms of the alkyl group are substituted with the acid group. One or more methylene groups constituting the alkyl group may be substituted with -O-, -C(=O)O-, -OC(=O)-, or -C(=O)NH- (except when oxygen atoms are bonded to each other). In addition, one or more hydrogen atoms of the alkyl group may be substituted with -CN.

[0015] The terminal portion containing the polymer may have, for example, the following structure.

[0016] [ka]

[0017] The resins for inks described herein can be used as dispersants for pigments (also called dispersing resins) and binder resins used in pigment dispersions. Examples of pigments include colorants such as pigments and dyes, near-infrared absorbing dyes, and infrared absorbing dyes. In this specification, inks can be used as materials for pigment-containing compositions such as paints, printing inks, inkjet inks, stationery inks, textile printing agents, photosensitive colored compositions for color filters, and compositions for forming optical filters. A pigment is a compound that absorbs a certain wavelength and exhibits some function, such as color.

[0018] Printing inks include flexographic inks and gravure inks. Applications of optical filter formation compositions include infrared cameras, solid-state image sensors, near-infrared absorption filters, near-infrared cut filters, and sensors such as LiDAR.

[0019] The ink resin is a polymer represented by the following general formula (1), where block A functions as a hydrophilic segment with charge repulsion and block B functions as a hydrophobic segment. When the ink resin of the present invention is used, for example, as a dispersant, the hydrophobic B block adsorbs to the colorant, while block A has high charge repulsion and acts as a steric repulsion site. This allows for fine dispersion of the colorant and suppresses entanglement between ink resins, thereby improving redispersibility. Furthermore, when forming a printed layer, the hydrophobic segment binds to a non-absorbent substrate, resulting in excellent durability. Note that the AB block polymer is a polymer having two polymer blocks with different functions, and includes block polymers synthesized in the order of AB and BA.

[0020] <Ink Resin> The resin for the ink is an AB block polymer having a portion at its end represented by the following general formula (1), wherein the A block contains an acidic group-containing monomer unit, and the B block contains one or more selected from the group consisting of an aromatic ring-containing monomer unit, an aliphatic ring-containing monomer unit, an alkyl (meth)acrylate unit, and a crosslinkable monomer unit.

[0021] <A-Bブロックポリマー> One embodiment of the ink resin described herein is a polymer represented by the following general formula (1). The AB block polymer used in the ink resin may be any block polymer having at least an A block and a B block, and it goes without saying that the structure is not limited to AB, BAB, ABA, ABC, etc., as long as the problem can be solved. The B block may contain acidic group-containing monomer units, but it is preferable that the content of acidic group-containing monomer units in the A block is greater than the content of acidic group-containing monomer units in the B block.

[0022] The monomer unit content of block A is preferably 5.0 to 40.0% by mass, more preferably 5.0 to 30.0% by mass, and even more preferably 5.0 to 20.0% by mass, of the total monomer units of the block AB polymer. By keeping the block ratio within the above range, durability can be improved while maintaining redispersibility.

[0023] The acid value of the ink resin is preferably 1 to 300 mg KOH / g, more preferably 1 to 20 mg KOH / g, and even more preferably 1 to 150 mg KOH / g. The acid value of block B of the dispersion resin is preferably 0 to 100 mg KOH / g, more preferably 0 to 50 mg KOH / g, and even more preferably 0 to 30 mg KOH / g. By keeping the acid value within the above range, durability can be improved while maintaining redispersibility.

[0024] <Units of acidic group-containing monomers> Examples of monomers containing acidic groups include carboxyl groups, sulfo groups, phosphate groups, and phosphonic acid groups.

[0025] Examples of carboxyl group-containing monomers include (meth)acrylic acid, 2-chloro(meth)acrylic acid, 3-chloro(meth)acrylic acid, 2-cyano(meth)acrylic acid, aconitic acid, mesaconic acid, maleic acid, maleic anhydride, itaconic acid, itaconic anhydride, fumaric acid, glutaconic acid, citraconic acid, utraconic acid, 1,4-di(meth)acryloyloxyethylpyromellitic acid, 6-(meth)acryloyloxynaphthalene-1,2,6-tricarboxylic acid, and 1-butyric acid. N-1,2,4-tricarboxylic acid, 3-butene-1,2,3-tricarboxylic acid, N-(meth)acryloyl-p-aminobenzoic acid, N-(meth)acryloyl-5-aminosalicylic acid, 4-(meth)acryloyloxyethyl trimellitic acid and its anhydride, 4-(meth)acryloyloxybutyl trimellitic acid and its anhydride, 2-(meth)acryloyloxybenzoic acid, β-(meth)acryloyloxyethyl hydrogen succinate, β-(meth)acrylo Iloxyethyl hydrogen maleate, 11-(meth)acryloyloxy-1,1-undecanedicarboxylic acid, p-vinylbenzoic acid, 4-(meth)acryloyloxyethoxycarbonylphthalic acid, 4-(meth)acryloyloxybutyloxycarbonylphthalic acid, 4-(meth)acryloyloxyhexyloxycarbonylphthalic acid, 4-(meth)acryloyloxyoctyloxycarbonylphthalic acid, 4-(meth)acryloyloxydecyloxy Examples include carbonylphthalic acid and its acid anhydrides, 5-(meth)acryloylaminopentylcarboxylic acid, 6-(meth)acryloyloxy-1,1-hexanedicarboxylic acid, 7-(meth)acryloyloxy-1,1-heptanedicarboxylic acid, 8-(meth)acryloyloxy-1,1-octanedicarboxylic acid, 10-(meth)acryloyloxy-1,1-decanedicarboxylic acid, 11-(meth)acryloyloxy-1,1-undecanedicarboxylic acid, and the like.

[0026] Examples of sulfo group-containing monomers include 2-(meth)acrylamido-2-methylpropanesulfonic acid, styrenesulfonic acid, 2-sulfoethyl (meth)acrylate, 4-(meth)acryloyloxybenzenesulfonic acid, 3-(meth)acryloyloxypropanesulfonic acid, and 2-(methacryloyloxy)ethanesulfonic acid.

[0027] The phosphate group-containing monomers are (meth)acryloyloxymethyl dihydrogen phosphate, 2-(meth)acryloyloxyethyl dihydrogen phosphate, 3-(meth)acryloyloxypropyl dihydrogen phosphate, 4-(meth)acryloyloxybutyl dihydrogen phosphate, 5-(meth)acryloyloxypentyl dihydrogen phosphate, and 6-(meth)acryloyloxyhexyl dihydrogen phosphate. phosphate, 7-(meth)acryloyloxyheptyl dihydrogen phosphate, 8-(meth)acryloyloxyoctyl dihydrogen phosphate, 9-(meth)acryloyloxynonyl dihydrogen phosphate, 10-(meth)acryloyloxydecyl dihydrogen phosphate, 11-(meth)acryloyloxyundecyl dihydrogen phosphate, 12-(meth)acryloyloxidedecyl dihydrogen phosphate Examples include 16-(meth)acryloyloxyhexadecyl dihydrogen phosphate, 20-(meth)acryloyloxyeicosyl dihydrogen phosphate, di(meth)acryloyloxyethyl hydrogen phosphate, di(meth)acryloyloxybutyl hydrogen phosphate, di(meth)acryloyloxyhexyl hydrogen phosphate, di(meth)acryloyloxyoctyl hydrogen phosphate, di(meth)acryloyloxynonyl hydrogen phosphate, di(meth)acryloyloxydecyl hydrogen phosphate, 1,3-di(meth)acryloyloxypropyl-2-dihydrogen phosphate, 2-(meth)acryloyloxyethylphenyl hydrogen phosphate, 2-(meth)acryloyloxyethyl 2'-bromoethyl hydrogen phosphate, and (meth)acryloyloxyethylphenyl phosphonate.

[0028] Examples of monomers containing phosphonic acid groups include 5-(meth)acryloyloxypentyl-3-phosphonopropionate, 6-(meth)acryloyloxyhexyl-3-phosphonopropionate, 10-(meth)acryloyloxydecyl-3-phosphonopropionate, 6-(meth)acryloyloxyhexyl-3-phosphonoacetate, and 10-(meth)acryloyloxydecyl-3-phosphonoacetate.

[0029] Among these, (meth)acrylic acid, 2-(methacryloyloxy)ethanesulfonic acid, and styrenesulfonic acid are preferred from the viewpoint of exhibiting polymerizability and good redispersibility.

[0030] Acidic group-containing monomer units can be used alone or in combination of two or more types.

[0031] The content of acidic group-containing monomer units is preferably 0.1 to 100.0% by mass, more preferably 0.1 to 80.0% by mass, and even more preferably 0.1 to 60.0% by mass, of the total monomer units in block A. By including an appropriate amount, both durability and redispersibility can be achieved.

[0032] Furthermore, the content of acidic group-containing monomer units is preferably 0.1 to 25% by mass of the total monomer units of the AB block polymer. By including an appropriate amount, both durability and redispersibility can be achieved.

[0033] <Other monomer units> Block A may contain hydrophobic monomer units and other monomer units in addition to acidic group-containing monomer units. Hydrophobic monomer units may include one or more monomer units selected from the group consisting of aromatic ring-containing monomer units, aliphatic ring-containing monomer units, and (meth)acrylate alkyl ester units. Other monomer units include, for example, (meth)acrylamide units, heterocyclic monomer units, hydroxyl group-containing monomer units, amino group-containing monomer units, cyano group-containing monomer units, epoxy group-containing monomer units, and other vinyl monomer units. Note that hydrophobic monomer units are monomer units that do not have hydrophilic groups such as hydroxyl groups and amino acid groups.

[0034] Examples of (meth)acrylamides include methyl(meth)acrylamide, ethyl(meth)acrylamide, propyl(meth)acrylamide, butyl(meth)acrylamide, t-butyl(meth)acrylamide, t-octyl(meth)acrylamide, cyclohexyl(meth)acrylamide, benzyl(meth)acrylamide, hydroxymethyl(meth)acrylamide, methoxymethyl(meth)acrylamide, butoxymethyl(meth)acrylamide, methoxyethyl(meth)acrylamide, phenyl(meth)acrylamide, dimethyl(meth)acrylamide, diethyl(meth)acrylamide, β-cyanoethyl(meth)acrylamide, N-(2-acetoacetoxyethyl)(meth)acrylamide, N,N'-methylenebis((meth)acrylamide), and diacetone(meth)acrylamide. Among these, methyl(meth)acrylamide, ethyl(meth)acrylamide, propyl(meth)acrylamide, butyl(meth)acrylamide, cyclohexyl(meth)acrylamide, benzyl(meth)acrylamide, and diacetone(meth)acrylamide are preferred.

[0035] Examples of heterocyclic monomers include N-vinyl-2-pyrrolidone, N-vinylcaprolactam, N-vinylpyrimidine, N-vinylpiperidone, N-vinylpyrrole, N-vinylimidazole, N-vinyloxazole, N-vinylpiperazine, and (meth)acryloylmorpholine.

[0036] Examples of hydroxyl group-containing monomers include hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 2 (or 3)-hydroxypropyl (meth)acrylate, 2 (or 3 or 4)-hydroxybutyl (meth)acrylate and cyclohexanedimethanol mono(meth)acrylate, and ethyl-α-hydroxymethyl acrylate.

[0037] Examples of amino group-containing monomers include dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, t-butylaminoethyl (meth)acrylate, methylethylaminoethyl (meth)acrylate, dimethylaminostyrene, diethylaminostyrene, pentamethylpiperidinyl (meth)acrylate, tetramethylpiperidinyl (meth)acrylate, and others.

[0038] Examples of cyano group-containing monomers include (meth)acrylonitrile, chloro(meth)acrylonitrile, and 2-cyanoethyl(meth)acrylic acid ester.

[0039] Examples of epoxy group-containing monomers include glycidyl (meth)acrylate and 3,4-epoxycyclohexyl (meth)acrylate.

[0040] Other vinyl monomer units include, for example, styrene macromers having a polymerizable functional group at one end, silicone macromers having a polymerizable functional group at one end, alkyl (meth)acrylate macromers having a polymerizable functional group at one end, and styrene-acrylonitrile macromers having a polymerizable functional group at one end. Among these, styrene macromers having a polymerizable functional group at one end are preferred.

[0041] Block B contains one or more units selected from the group consisting of aromatic ring-containing monomer units, aliphatic ring-containing monomer units, (meth)acrylate alkyl ester units, and crosslinkable monomer units. Of these units, one or more units selected from the group consisting of aromatic ring-containing monomer units, aliphatic ring-containing monomer units, and (meth)acrylate alkyl ester units are collectively referred to as hydrophobic monomer units.

[0042] <Hydrophobic monomer units> Aromatic ring-containing monomers include, for example, benzyl (meth)acrylate, phenyl (meth)acrylate, phenoxyethyl (meth)acrylate, phenoxyethylene glycol (meth)acrylate, phenoxydiethylene glycol (meth)acrylate, phenoxydiethylene glycol (meth)acrylate, 2-naphthyl (meth)acrylate, 9-anthracenyl (meth)acrylate, 1-pyrenylmethyl (meth)acrylate, styrene, and vinyl naphtha. Examples include benzene, α-methylstyrene, 4-tert-butylstyrene, p-methylstyrene, o-methoxystyrene, m-methoxystyrene, p-methoxystyrene, ot-butoxystyrene, mt-butoxystyrene, pt-butoxystyrene, o-chloromethylstyrene, m-chloromethylstyrene, p-chloromethylstyrene, vinyltoluene, ethyl vinylbenzene, 4-vinylbiphenyl, 1,1-diphenylethylene, vinylphenol, vinyl benzoate, vinylnaphthalene, benzyl vinyl ether, etc.

[0043] Among these, monomer structures having an unsubstituted phenyl group, such as benzyl (meth)acrylate, phenyl (meth)acrylate, phenoxyethyl (meth)acrylate, phenoxyethylene glycol (meth)acrylate, phenoxydiethylene glycol (meth)acrylate, phenoxydiethylene glycol (meth)acrylate, styrene, and α-methylstyrene, are preferred, with styrene and benzyl (meth)acrylate being more preferred.

[0044] Aliphatic ring-containing monomers include, for example, (meth)acrylate esters such as cyclopropyl (meth)acrylate, cyclobutyl (meth)acrylate, cyclopentyl (meth)acrylate, cyclohexyl (meth)acrylate, cycloheptyl (meth)acrylate, cyclooctyl (meth)acrylate, cyclononyl (meth)acrylate, cyclodecyl (meth)acrylate, isobornyl (meth)acrylate, norbornyl (meth)acrylate, adamantyl (meth)acrylate, etc.; and cyclic olefins such as cyclopentene, cycloheptene, cyclooctene, cyclododecene, 1,5-cyclooctadiene, cyclopentadiene, 1,5,9-cyclododecatriene, 1-chloro-1,5-cyclooctadiene, dicyclopentadiene, ethylidene norbornene, methyl 5-norbornene-2-carboxylate, and dimethyl 5-norbornene-2,3-dicarboxylate.

[0045] Among these, cyclohexyl (meth)acrylate and isobornyl (meth)acrylate are preferred.

[0046] Examples of alkyl (meth)acrylate esters include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, iso-propyl (meth)acrylate, butyl (meth)acrylate, i-butyl (meth)acrylate, tert-butyl (meth)acrylate, amyl (meth)acrylate, i-amyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, octyl (meth)acrylate, i-octyl (meth)acrylate, decyl (meth)acrylate, i-decyl (meth)acrylate, dodecyl (meth)acrylate, i-dodecyl (meth)acrylate, stearyl (meth)acrylate, i-stearyl (meth)acrylate, and behenyl (meth)acrylate (meth)acrylate esters.

[0047] Among these, methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, iso-propyl (meth)acrylate, butyl (meth)acrylate, i-butyl (meth)acrylate, and tert-butyl (meth)acrylate are preferred.

[0048] Hydrophobic monomer units can be used alone or in combination of two or more types.

[0049] The hydrophobic monomer units preferably include two or more selected from the group consisting of aromatic ring-containing monomer units, aliphatic ring-containing monomer units, and (meth)acrylate alkyl ester units.

[0050] The content of hydrophobic monomer units is preferably 80.0 to 100.0% by mass, more preferably 85.0 to 100.0% by mass, and even more preferably 90.0 to 100.0% by mass, of the total monomer units in block B. Including an appropriate amount dramatically improves durability.

[0051] <Cross-linkable monomer units> Crosslinkable monomers include monomers having two or more ethylenic double bonds in their molecule, and monomers containing alkoxysilyl groups. Monomers having two or more ethylenic double bonds in their molecule include, for example, allyl(meth)acrylates such as allyl(meth)acrylate; ethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate; 1,4-butanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 3-methyl-1,5-pentanediol di(meth)acrylate, 1,8-octanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 2,4-diethyl-1,5-pentanediol di(meth)acrylate, and butylethylpropanediol di(meth)acrylate. Alkanediolic di(meth)acrylates such as acrylate, 1,10-decanediol di(meth)acrylate, 3-methyl-1,7-octanediolic di(meth)acrylate, 2-methyl-1,8-octanediolic di(meth)acrylate, 1,12-dodecanediol di(meth)acrylate, and 1,3-butylenedi(meth)acrylate; di(meth)acrylate monomers such as polyalkylene glycol di(meth)acrylate (the number of repeating alkylene glycol units is, for example, 2 to 150), including polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, and polytetramethylene glycol di(meth)acrylate; Divinyl monomers such as N,N-divinylaniline, divinyl ether, divinyl sulfide, divinyl sulfonic acid, divinylbenzene, divinylnaphthalene, divinyltoluene, and 4,4'-divinylbiphenyl; diallyl phthalate, Compounds in which three or more (meth)acrylic acids are esterified, such as trimethylolpropane tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, and dipentaerythritol hexa(meth)acrylate; Examples of monomers containing alkoxysilyl groups include 3-(trimethoxysilyl)propyl (meth)acrylate and vinyltriethylsilane.

[0052] Among these, allyl (meth)acrylate, ethylene glycol di(meth)acrylate, diallyl phthalate, and -(trimethoxysilyl)propyl(meth)acrylate are preferred, with allyl (meth)acrylate being particularly preferred.

[0053] Crosslinkable monomer units can be used alone or in combination of two or more types.

[0054] The content of crosslinkable monomer units is preferably 0.1 to 25.0% by mass, more preferably 0.1 to 15.0% by mass, and even more preferably 0.1 to 5.0% by mass, of the total monomer units of block B. By including an appropriate amount, durability can be further improved while maintaining redispersibility.

[0055] <Other monomer units> Block B may contain acidic group-containing monomer units and other monomer units in addition to hydrophobic monomer units and crosslinkable monomer units. Examples of other monomer units include (meth)acrylamide units, heterocyclic monomer units, hydroxyl group-containing monomer units, amino group-containing monomer units, cyano group-containing monomer units, epoxy group-containing monomer units, and other vinyl monomer units.

[0056] <Synthesis method> The AB block polymer can be any AB block polymer having the moiety shown in general formula (1), and its synthesis method is not limited. In this specification, polymers synthesized by living radical polymerization are preferred. Living radical polymerization methods include those using sulfur-based reversible chain transfer (RAFT method), those using organotellurium compounds (TERP method), those using transition metal catalysts (ATRP method), and nitroxide-mediated radical polymerization (NMP method), depending on the method used to stabilize the polymerization growth ends. Among these, the RAFT method is preferred because it can control the polymerization of both conjugated and unconjugated monomers.

[0057] <Living polymerizing agent> A living polymerization agent is a compound used in living radical polymerization. Therefore, a living radical polymer has a living polymer residue. Examples of the living polymerization agent include a thiocarbonyl compound, an organic tellurium compound, an organic ditellurium compound, and the like.

[0058] <Reversible Addition-Fragmentation Chain Transfer Polymerization (RAFT method)> The RAFT method is a method in which a reversible exchange chain transfer reaction occurs more rapidly than the growth reaction, enabling all polymers to grow uniformly. A RAFT agent is an organic sulfur compound essential for synthesizing a living polymer by the RAFT method.

[0059] <RAFT agent> Examples of the RAFT agent include a dithiobenzoate type, a trithiocarbonate type, a dithiocarbamate type, and the like. Among these, the trithiocarbonate type is preferred for using monomers such as styrene and methacrylic acid esters.

[0060] Examples of the dithiobenzoate type include 2-cyanopropan-2-yl dithiobenzoate, 4-cyano-4-[(thiobenzoyl)sulfanyl]pentanoic acid, and the like.

[0061] Trithiocarbonate types include, for example, 4-cyano-4-[(dodecylsulfanylthiocarbonyl)sulfanyl]pentanoic acid, 2-cyano-2-[(dodecylsulfanylthiocarbonyl)sulfanyl]propane, S,S-dibenzyltrithiocarbonate, 4-cyano-4-[(dodecylsulfanylthiocarbonyl)sulfanyl]methyl pentanoate, trithiocarbonate=bis[4-(allyloxycarbonyl)benzyl], trithiocarbonate=bis{4-[ethyl-(2-acetyloxy Examples include bis(4-(2-hydroxyethyl)carbamoyl)benzyl trithiocarbonate, bis(4-(2-hydroxyethoxycarbonyl)benzyl) trithiocarbonate, 2-(dodecylthio)carbonothioyl)thiopropanoic acid, 3-(1-carboxyethyl)thio)carbonothioyl)thiopropanoic acid, 4-(2-carboxyethyl)thio)carbonothioyl)thio-4-cyanopentanoic acid, etc.

[0062] Examples of dithiocarbamate types include 4-chloro-3,5-dimethylpyrazole-1-carbodithiose 2'-cyanobutan-2'-yl, 3,5-dimethylpyrazole-1-carbodithiose 2'-cyanobutan-2'-yl, 3,5-dimethylpyrazole-1-carbodithiose cyanomethyl, and N-methyl-N-phenyldithiocarbamate cyanomethyl.

[0063] Among these, compounds having an acid group selected from the group consisting of dithiobenzoate type and trithiocarbonate type, represented by the general formula (3) below, and -CO2H and -SO3H are preferred, and compounds having -CO2H are more preferred. General formula (3) [ka]

[0064] [In general formula (3), Z represents an organic group selected from alkyl groups, aryl groups, arylalkyl groups, alkylthio groups, arylthio groups, and arylalkylthio groups, and some of the organic groups represented by Z may be substituted. * represents a bond.]

[0065] The following compounds are preferred examples of RAFT agents represented by general formula (3). [ka]

[0066] The amount of RAFT agent used is preferably 0.1 to 15.0 parts by mass, more preferably 0.1 to 10.0 parts by mass, and even more preferably 0.1 to 5.0 parts by mass, per 100 parts by mass of the total monomers used in the synthesis of the AB block polymer. If the amount of RAFT agent used is too high, durability will deteriorate, and if the amount of RAFT agent used is too low, the rate of precision polymerization will decrease significantly. By including an appropriate amount, precision polymerization will proceed smoothly, and an ink resin with excellent durability can be obtained.

[0067] Other embodiments of the resins for inks described herein are polymers represented by the following general formula (2): The aforementioned polymer is an AB block polymer, The aforementioned Block A contains an acidic group-containing monomer unit, The aforementioned Block B contains one or more units selected from the group consisting of aromatic ring-containing monomer units, aliphatic ring-containing monomer units, (meth)acrylate alkyl ester units, and crosslinkable monomer units.

[0068] General formula (2) [ka]

[0069] [In general formula (2), Polymer represents an AB block polymer, and a portion of the AB block polymer may be substituted with a functional group. Z represents an organic group selected from alkyl groups, aryl groups, arylalkyl groups, alkylthio groups, arylthio groups, and arylalkylthio groups, and a portion of the organic group may be substituted. R 1 [wherein -1 represents an organic group, the organic group having one or more acidic groups selected from -CO2H and -SO3H, which are neutralized by a basic compound.]

[0070] Another embodiment of the ink resin described herein involves R at one end of the AB block polymer. 1 Because of this property, for example, when used in inkjet ink applications, the ink can be redispersed after it has solidified, resulting in an ink that is less prone to nozzle ejection failure.

[0071] The polymer represented by general formula (2) is obtained by the synthesis of a polymer using a RAFT agent having an acid group selected from -CO2H and -SO3H.

[0072] The aforementioned R 1 The organic group represented by is not limited, and examples include an organic group in which a linear or branched monovalent alkyl group of C1 to C10 is used as the basic skeleton, and one or more hydrogen atoms of the alkyl group are substituted with the acid group. One or more methylene groups constituting the alkyl group may be substituted with -O-, -C(=O)O-, -OC(=O)-, or -C(=O)NH- (except when oxygen atoms are bonded to each other). In addition, one or more hydrogen atoms of the alkyl group may be substituted with -CN.

[0073] The aforementioned R 1 Examples include -CH2CO2H, -CH2CH2CO2H, -CH(CH3)CO2H, -CH(CO2H)CH2CO2H, -C(CH3)(CH3)CO2H, -C(CN)(CH3)CH2CH2CO2H, and -CH(CH3)CONRaRb. Ra and Rb are each independently selected from H, C1-C6 alkyl groups, C1-C6 alkoxy groups, C6-C12 aryl groups, C7-C18 alkylaryl groups, and C6-C12 heteroaryl groups. However, it is preferable that at least one of the hydrogen atoms in Ra and Rb is substituted by an acid group selected from -CO2H and -SO3H, and that the acid group forms a salt. Ra and Rb may be the same or different.

[0074] In this specification, the term "aryl group" refers to a group derived from an aromatic hydrocarbon, i.e., a functional group or substituent containing an aromatic ring. The term "heteroaryl group" refers to a group in which one or more carbon atoms of the aryl group are substituted with atoms other than carbon atoms (e.g., nitrogen, oxygen, or sulfur atoms). The ring constituting the aryl group may be monocyclic or polycyclic. Each ring is preferably a five-membered or six-membered ring. Examples of aryl groups include benzene, biphenyl, terphenyl, quaterphenyl, naphthalene, tetrahydronaphthalene, 1-benzylnaphthalene, anthracene, dihydroanthracene, benzoanthracene, dibenzoanthracene, phenanthrazene, perylene, pyridine, 4-phenylpyridine, 3-phenylpyridine, thiophene, benzothiophene, naphthothiophene, thianthrene, furan, benzofuran, pyrene, isobenzofuran, chromene, xanthene, phenoxatiin, pyrrole, imidazole, pyrazole, pyrazine, pyrimidine, pyridazine, indole, indidine, isoindole, purine, quinoline, isoquinoline, phthalazine, quinoxaline, quinazoline, pteridine, carbazole, carboline, phenanthidine, acridine, phenanthroline, phenazine, isothiazole, isoxazole, phenoxazine, and the like.

[0075] In this specification, the term "arylalkyl group" refers to an aromatic alkyl group, and includes groups in which the terminal hydrogen atoms of a linear alkyl group (e.g., C1-C6) are substituted with an aryl group. Examples of arylalkyl groups include benzyl, phenethyl, diphenylmethyl, triphenylmethyl, 1-naphthylmethyl, 2-naphthylmethyl, 2,2-diphenylethyl, 3-phenylpropyl, 4-phenylbutyl, and 5-phenylpentyl.

[0076] The organic group represented by Z is an organic group selected from alkyl groups, aryl groups, arylalkyl groups, alkylthio groups, arylthio groups, and arylalkylthio groups.

[0077] Examples of the alkyl groups include linear, branched, and cyclic alkyl groups of C1 to C20, as well as alkyl groups formed by any combination thereof. In general formulas (1) to (3), when Z is a cyclic alkyl group or a group having a cyclic alkyl group, one or more carbon atoms constituting the cyclic alkyl group may be substituted with nitrogen, oxygen, or sulfur atoms (except when oxygen atoms are bonded to each other). Among the carbon atoms of the cyclic alkyl group, the carbon atom bonded to the thioketone group (>C=S) of formulas (1) to (3) may be substituted with the above heteroatoms. In addition, one or more methylene groups (-CH2-) constituting the cyclic alkyl group may be substituted with a ketone group (>C=O). The above cyclic alkyl groups are preferably 5 to 8-membered rings, and more preferably 5 or 6-membered rings.

[0078] The alkylthio group is a group in which the alkyl group is bonded to a sulfide bond (-S-). The arylthio group is a group in which an aryl group is bonded to a sulfide group. The arylalkylthio group is a group in which an arylalkyl group is bonded to a sulfide group.

[0079] In general formulas (1) to (3), Z is preferably an alkylthio group from the viewpoint of durability of the ink resin.

[0080] A portion of the organic group represented by Z in general formula (1) can be substituted with any group. In this specification, "arbitrarily substituted" and "substituted with any group" mean that a portion of the organic group (e.g., a hydrogen atom, a methylene group, a methyl group, etc.) is alkyl, alkenyl, alkynyl, aryl, halo, haloalkyl, haloalkenyl, haloalkynyl, haloaryl, hydroxy, alkoxy, alkenyloxy, aryloxy, benzyloxy, haloalkoxy, haloalkenyloxy, acetyleno, carboxymidyl, haloaryloxy, isocyano, cyano, formyl, carboxyl, nitro, nitroalkyl, nitroalkenyl, nitroalkynyl, nitroaryl, alkylamino, dialkylamino, alkenylamino, alkynylamino, arylamino, diarylamino, benzylamino, imino, alkylimine, alkenylimine, alkynylimino, arylimino, benzylimino This means that the group is substituted with one or more groups selected from dibenzylamino, acyl, alkenylacyl, alkynylacyl, arylacyl, acylamino, diacylamino, acyloxy, alkylsulfonyloxy, arylsulfenyloxy, heterocyclyl, heterocyclooxy, heterocyclamino, haloheterocyclyl, alkylsulfonyl, arylsulfonyl, alkylsulfinyl, arylsulfinyl, carboalkoxy, alkylthio, benzylthio, acylthio, sulfonamide, sulfanyl, sulfo and phosphorus-containing groups, alkoxysilyl, silyl, alkylsilyl, alkylalkoxysilyl, phenoxysilyl, alkylphenoxysilyl, alkoxyphenoxysilyl, arylphenoxysilyl, allophanyl, guanidino, hydantoyl, ureido and ureylene.

[0081] In this specification, the terms "halogen" and "halo" refer to iodine, bromine, chlorine, and fluorine, unless otherwise specified.

[0082] In the above definition, the term "alkyl," used alone or in compound words such as "alkenyloxyalkyl," "alkylthio," "alkylamino," and "dialkylamino," refers to linear, branched, or cyclic alkyl groups, preferably C1-20 alkyl or cycloalkyl groups. Examples of linear and branched alkyl groups include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, amyl, isoamyl, sec-amyl, 1,2-dimethylpropyl, 1,1-dimethylpropyl, hexyl, 4-methylpentyl, 1-methylpentyl, 2-methylpentyl, 3-methylpentyl, 1,1-dimethylbutyl, 2,2-dimethylbutyl, 3,3-dimethylbutyl, 1,2-dimethylbutyl, and 1,3-dimethylbutyl. , 1,2,2-trimethylpropyl, 1,1,2-trimethylpropyl, heptyl, 5-methoxyhexyl, 1-methylhexyl, 2,2-dimethylpentyl, 3,3-dimethylpentyl, 4,4-dimethylpentyl, 1,2-dimethylpentyl, 1,3-dimethylpentyl, 1,4-dimethylpentyl, 1,2,3-trimethylbutyl, 1,1,2-trimethylbutyl, 1,1,3-trimethylbutyl, octyl, 6-methylheptyl, 1-methylheptyl, 1,1,3,3 -Tetramethylbutyl, nonyl, 1-,2-,3-,4-,5-,6- or 7-methyloctyl, 1-,2-,3-,4- or 5-ethylheptyl, 1-,2- or 3-propylhexyl, decyl, 1-,2-,3-,4-,5-,6-,7- and 8-methylnonyl, 1-,2-,3-,4-,5- or 6-ethyloctyl, 1-,2-,3- or 4-propylheptyl, undecyl, 1-,2-,3-,4-,5-,6-,7-,8- or 9-methyldecyl, 1-,2-,3 Examples include -, 4-, 5-, 6- or 7-ethyl nonyl, 1-, 2-, 3-, 4- or 5-propyl octyl, 1-, 2- or 3-butylheptyl, 1-pentylhexyl, dodecyl, 1-, 2-, 3-, 4-, 5-, 6-, 7-, 8-, 9- or 10-methyl undecyl, 1-, 2-, 3-, 4-, 5-, 6-, 7- or 8-ethyl decyl, 1-, 2-, 3-, 4-, 5- or 6-propyl nonyl, 1-, 2-, 3- or 4-butyl octyl, 1-2-pentylheptyl, etc.Examples of cyclic alkyl groups include monocyclic or polycyclic alkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, and cyclodecyl.

[0083] The term "alkoxy" refers to linear or branched alkoxys, preferably C1-C20 alkoxys. Examples of alkoxys include methoxy, ethoxy, n-propoxy, isopropoxy, and various butoxy isomers.

[0084] The term "alkenyl" refers to a group formed from a linear, branched, or cyclic alkene, preferably C2-20, including mono, di, or polyethylene unsaturated alkyl or cycloalkyl groups as previously defined. Examples of alkenyls include vinyl, allyl, 1-methylvinyl, butenyl, isobutenyl, 3-methyl-2-butenyl, 1-pentenyl, cyclopentenyl, 1-methyl-cyclopentenyl, 1-hexenyl, 3-hexenyl, cyclohexenyl, 1-heptenyl, 3-heptenyl, 1-octenyl, cyclooctenyl, 1-nonenyl, 2-nonenyl, 3-nonenyl, 1- Examples include decenyl, 3-decenyl, 1,3-butadienyl, 1,4-pentadienyl, 1,3-cyclopentadienyl, 1,3-hexadienyl, 1,4-hexadienyl, 1,3-cyclohexadienyl, 1,4-cyclohexadienyl, 1,3-cycloheptadienyl, 1,3,5-cycloheptatrielinyl, and 1,3,5,7-cyclooctatetraenyl.

[0085] The term "alkynyl" refers to groups formed from linear, branched, or cyclic alkynes, preferably C2-20, including those structurally similar to alkyl and cycloalkyl groups as defined above. Examples of alkynyls include ethynyl, 2-propynyl, and 2- or 3-butenyl.

[0086] The term "acyl," whether in compound words such as "acyloxy," "acylthio," "acylamino," or "diacylamino," or alone, refers to a carbamoyl group, an aliphatic acyl group, and an acyl group containing an aromatic ring (referred to as an aromatic acyl) or an acyl group containing a heterocyclic ring (referred to as a heterocyclic acyl), preferably a C1-20 acyl. Examples of acyls include carbamoyl; formyl, acetyl, propanoyl, butanoyl, 2-methylpropanoyl, pentanoyl, 2,2-dimethylpropanoyl, hexanoyl, heptanyl, octanoyl, nonanoyl, decanoyl, undecanoyl, dodecanoyl, tridecanoyl, tetradecanoyl, pentadecanoyl, hexadecanoyl, heptadecanoyl, octadecanoyl, nonadecanoyl, and eicosanoyl, which are linear or branched alkanoyls; Alkoxycarbonyls such as methoxycarbonyl, ethoxycarbonyl, t-butoxycarbonyl, t-pentyloxycarbonyl, and heptyloxycarbonyl; cycloalkylcarbonyls such as cyclopropylcarbonyl, cyclobutylcarbonyl, cyclopentylcarbonyl, and cyclohexylcarbonyl; alkylsulfonyls such as methylsulfonyl and ethylsulfonyl; alkoxysulfonyls such as methoxysulfonyl and ethoxysulfonyl; benzoyl Aroyls such as phenyl, phenylpropanoyl, and naphthoyl; aralkanoyls such as phenylalkanoyl (e.g., phenylacetyl, phenylpropanoyl, phenylbutanoyl, phenylisobutyryl, phenylpentanoyl, and phenylhexanoyl) and naphthylalkanoyl (e.g., naphthylacetyl, naphthylpropanoyl, and naphthylbutanoyl); aralkenoyls such as phenylalkenoyl (e.g., phenylpropenoyl, phenylbutenoyl, phenylmethacryloyl, phenylpentenoyl, and phenylhexenoyl) and naphthylalkenoyl (e.g., naphthylpropenoyl, naphthylbutenoyl, and naphthylpentenoyl); aralcoxycarbonyls such as phenylalkoxycarbonyl (e.g., benzyloxycarbonyl); aryloxycarbonyls such as phenoxycarbonyl and naphthyloxycarbonyl; aryloxyalkanoyls such as phenoxyacetyl and phenoxypropionyl;Examples include arylcarbamoyls such as phenylcarbamoyl; arylthiocarbamoyls such as phenylthiocarbamoyl; arylglyoxyloyls such as phenylglyoxyloyl and naphthylglyoxyloyl; arylsulfonyls such as phenylsulfonyl and naphthylsulfonyl; heterocyclic carbonyls; heterocyclic alkanoyls such as thienylacetyl, thienylpropanoyl, thienylbutanoyl, thienylpentanoyl, thienylhexanoyl, thiazolylacetyl, thiadiazolylacetyl, and tetrazolylacetyl; heterocyclic alkenoyls such as heterocyclic propenoyl, heterocyclic butenoyl, heterocyclic pentenoyl, and heterocyclic hexenoyl; and heterocyclic glyoxyloyls such as thiazolylglyoxyloyl and thienylglyoxyloyl.

[0087] The RAFT agent is, for example, the same as described in 3a to 3m above.

[0088] In this specification, when used alone or as part of terms such as “heterocyclic alkenoyl,” “heterocyclooxy” (“heterocycloxy”) or “haloheterocyclyl,” the terms “heterocyclic,” “heterocyclyl,” and “heterocyclyl” refer to aromatic, pseudo-aromatic, and non-aromatic rings or ring systems containing one or more heteroatoms selected from nitrogen, oxygen, and sulfur atoms, which may be optionally substituted. Preferably, the ring or ring system has 3 to 20 carbon atoms. The ring or ring system may be selected from those described above in relation to the definition of “heteroaryl.”

[0089] <Basic compounds> Basic compounds include, for example, inorganic amines such as ammonia; organic amines such as dimethylamine, dimethylaminoethanol, diethanolamine, and triethanolamine; and inorganic alkalis such as alkali metal hydroxides such as sodium hydroxide, lithium hydroxide, and potassium hydroxide.

[0090] Among these, inorganic amines, organic amines, and alkali metal hydroxides are preferred from the viewpoint of increasing the charge repulsion force that emerges after neutralization and exhibiting good redispersibility. Ammonia is preferred as an inorganic amine. Dimethylamine, dimethylaminoethanol, and triethanolamine are preferred as organic amines. Sodium hydroxide and potassium hydroxide are preferred as alkali metal hydroxides.

[0091] From the viewpoint of emulsification, the basic compound used to neutralize the RAFT agent is preferably used in an amount of 10 to 200 mol%, more preferably 4 to 160 mol%, and even more preferably 70 to 130 mol%, relative to 100 mol% of the carboxyl groups contained in the RAFT agent.

[0092] Basic compounds can be used alone or in combination of two or more types.

[0093] <Radical polymerization initiator> Radical polymerization initiators can be used in combination with RAFT agents for the synthesis of resins for inks. Examples of radical polymerization initiators include azo polymerization initiators, photopolymerization initiators, inorganic peroxides, organic peroxides, and redox initiators that combine organic peroxides, transition metals, and reducing agents. Among these, azo polymerization initiators, inorganic peroxides, organic peroxides, and redox initiators that can initiate polymerization by heating are preferred. These may be used individually or in combination of two or more. Water-soluble polymerization initiators are preferred.

[0094] Polymerization initiators can contain acidic groups. When a polymerization initiator has an acidic group, for example, it can be reacted with a basic compound to form a salt with the acidic group. Examples of the acidic group include one or more acidic groups selected from -CO2H and -SO3H. Among these, -CO2H is preferred from the viewpoint of easily adjusting the pH of the reaction solution by forming a salt. A water-soluble polymerization initiator is a polymerization initiator that dissolves at a concentration of 1 g or more in 100 g of water at 20°C.

[0095] Examples of radical polymerization initiators include dialkyl peroxides such as di-t-butyl peroxide, dicumyl peroxide, t-butylcumyl peroxide, α,α'-bis(t-butylperoxy-m-isopropyl)benzene, and 2,5-di(tert-butylperoxy)hexine-3; Peroxyesters such as t-butyl peroxybenzoate, t-butyl peroxyacetate, and 2,5-dimethyl-2,5-di(benzoylperoxy)hexane; Ketone peroxides such as cyclohexanone peroxide, 3,3,5-trimethylcyclohexanone peroxide, and methylcyclohexanone peroxide; Peroxyketals such as 2,2-bis(4,4-di-t-butylperoxycyclohexyl)propane, 1,1-bis(t-butylperoxy)3,3,5-trimethylcyclohexane, 1,1-bis(t-butylperoxy)cyclohexane, and n-butyl-4,4-bis(t-butylperoxy)barate; Hydroperoxides such as cumene hydroperoxide, diisopropylbenzene hydroperoxide, and 2,5-dimethylcyclohexane-2,5-dihydroperoxide; Diacyl peroxides such as benzoyl peroxide, decanoyl peroxide, lauroyl peroxide, and 2,4-dichlorobenzoyl peroxide; Organic peroxide initiators such as peroxydicarbonates including bis(t-butylcyclohexyl)peroxydicarbonate, Examples include azo initiators such as 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), 1,1'-azobis(cyclohexane1-carbonitride), 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(2,4-dimethyl-4-methoxyvaleronitrile), dimethyl2,2'-azobis(2-methylpropionate), 4,4'-azobis(4-cyanovaleric acid), 2,2'-azobis(2-hydroxymethylpropionitrile), and 2,2'-azobis[2-(2-imidazolin-2-yl)propane], or mixtures thereof.

[0096] Among these polymerization initiators, azo initiators are preferred from the viewpoint of reactivity in living polymerization, and water-soluble azo initiators are preferred from the viewpoint of emulsion polymerization. From the viewpoint of water solubility, compounds containing one or more acid groups selected from -CO2H and -SO3H are preferred, and among these, compounds containing -CO2H are more preferred.

[0097] <Synthesis of resins for inks> In this specification, the method for producing an ink resin involves synthesizing an AB block polymer comprising the following steps 1 and either step 2 or step 3. That is, a method of performing steps 1 and 2, or step 1 and step 3, is preferred.

[0098] <Process 1> Step 1 is a step of mixing a compound having the structure shown in the following general formula (3) and one or more acidic groups selected from the group consisting of -CO2H and -SO3H, a basic compound, and water to obtain a mixed solution.

[0099] Water, a basic compound, and a compound having one or more acidic groups selected from the group consisting of the structure shown in the general formula (3) below and -CO2H and -SO3H (RAFT agent) are added to a flask, and the mixture is heated and stirred at 40-90°C for 30 minutes to 3 hours to solubilize the RAFT agent. Solubilizing the RAFT agent allows the precise polymerization to proceed smoothly. The solubilization temperature is preferably 40-90°C, as this temperature facilitates solubilization while preventing the RAFT agent from decomposing easily.

[0100] Basic compounds include, for example, inorganic amines such as ammonia; organic amines such as dimethylamine, dimethylaminoethanol, diethanolamine, and triethanolamine; and inorganic alkalis such as alkali metal hydroxides such as sodium hydroxide, lithium hydroxide, and potassium hydroxide.

[0101] From the viewpoint of water solubility, the amount of basic compound used is preferably 10 to 200 mol%, more preferably 40 to 160 mol%, and even more preferably 70 to 130 mol%, relative to 100 mol% of the acid groups contained in the RAFT agent.

[0102] <Process 2> Step 2 involves reacting the mixture, an acidic group-containing monomer, and a polymerization initiator to synthesize block A and produce an aqueous polymer solution, and then reacting the aqueous polymer solution with a solution containing one or more monomers selected from the group consisting of aromatic ring-containing monomers, aliphatic ring-containing monomers, alkyl (meth)acrylates, and crosslinkable monomer units, and a polymerization initiator to synthesize block B and obtain an aqueous AB block polymer solution having a site at the end represented by the following general formula (3).

[0103] To the mixture obtained in step 1, an initiator solution prepared by mixing and dissolving monomers constituting block A, water, a basic compound, and a polymerization initiator is added dropwise, and a polymerization reaction is carried out at 50-90°C for 2-7 hours. Subsequently, an initiator solution prepared by mixing and dissolving monomers constituting block B, water, a basic compound, and a polymerization initiator is added dropwise, and a polymerization reaction is carried out at 50-90°C for 2-7 hours to obtain an aqueous solution of AB block polymer having a site shown in the following general formula (3) at its end. After that, a basic compound is added to neutralize the acid group-containing monomer units and obtain an ink resin.

[0104] The neutralization rate of acid group-containing monomer units can be adjusted as needed, and neutralization can be performed either after polymerization of block A or after polymerization of block B.

[0105] <Process 3> Step 3 is a step in which the mixture and a solution containing one or more monomers selected from the group consisting of aromatic ring-containing monomers, aliphatic ring-containing monomers, alkyl (meth)acrylate esters, and crosslinkable monomer units, as well as a polymerization initiator, are reacted to synthesize block A and produce an aqueous polymer solution, and the aqueous polymer solution, acid group-containing monomer, and polymerization initiator are reacted to synthesize block B to obtain an aqueous AB block polymer solution having a site at the end represented by the following general formula (3).

[0106] To the mixture obtained in step 1, an initiator solution prepared by mixing and dissolving monomers constituting block B, water, a basic compound, and a polymerization initiator is added dropwise, and a polymerization reaction is carried out at 50-90°C for 2-7 hours. Subsequently, an initiator solution prepared by mixing and dissolving monomers constituting block A, water, a basic compound, and a polymerization initiator is added dropwise, and a polymerization reaction is carried out at 50-90°C for 2-7 hours to obtain an aqueous solution of AB block polymer having a site shown in the following general formula (3) at its end. After that, a basic compound is added to neutralize the acid group-containing monomer units and obtain an ink resin.

[0107] The neutralization rate of acid group-containing monomer units can be adjusted as needed, and neutralization can be performed either after polymerization of block A or after polymerization of block B.

[0108] General formula (3) [ka]

[0109] [In general formula (3), Z represents an organic group selected from alkyl groups, aryl groups, arylalkyl groups, alkylthio groups, arylthio groups, and arylalkylthio groups, and some of the organic groups represented by Z may be substituted. * represents a bond.]

[0110] The RAFT agent having the part shown in general formula (3) is the same as 3a to 3m described above.

[0111] The method for producing the resin for ink described herein is preferably a method that involves steps 1 and 2.

[0112] <Water-based ink> The aqueous inks described herein may contain an ink resin, a colorant, and a water-soluble solvent. Applications of aqueous inks include inks for letterpress printing, flexographic printing, etc., inks for gravure printing, etc., inks for stencil printing, etc., and inkjet printing inks. Among these, inkjet inks are preferred.

[0113] <Coloring agent> Colorants can be selected and used as appropriate from organic pigments, inorganic pigments, and dyes.

[0114] Examples of organic pigments include azo pigments, diazo pigments, phthalocyanine pigments, quinacridone pigments, isoindolinone pigments, dioxazine pigments, perylene pigments, perinone pigments, thioindigo pigments, anthraquinone pigments, and quinophthalone pigments.

[0115] The pigments are exemplified below by their CI numbers. Red pigments include, for example, CIPigmentRed1, 2, 3, 4, 5, 6, 7, 9, 10, 14, 17, 22, 23, 31, 32, 38, 41, 48:1, 48:2, 48:3, 48:4, 49, 49:1, 49:2, 52:1, 52:2, 53:1, 57:1, 60:1, 63:1, 66, 67, 81:1, 81:2, 81:3, 83, 88, 90, 105, 112, 119, 122, 123, 14 Examples include 4, 146, 147, 148, 149, 150, 155, 166, 168, 169, 170, 171, 172, 175, 176, 177, 178, 179, 184, 185, 187, 188, 190, 200, 202, 206, 207, 208, 209, 210, 216, 220, 224, 226, 242, 246, 254, 255, 264, 266, 269, 270, 272, 279, etc.

[0116] Yellow pigments include, for example, CIPigmentYellow1, 2, 3, 4, 5, 6, 10, 11, 12, 13, 14, 15, 16, 17, 18, 20, 24, 31, 32, 34, 35, 35:1, 36, 36:1, 37, 37:1, 40, 42, 43, 53, 55, 60, 61, 62, 63, 65, 73, 74, 77, 81, 83, 86, 93, 94, 95, 97, 98, 100, 101, 104, 106, 108, 109, 110, 113, 114, 115, Examples include 116, 117, 118, 119, 120, 123, 125, 126, 127, 128, 129, 137, 138, 139, 147, 148, 150, 151, 152, 153, 154, 155, 156, 161, 162, 164, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175, 176, 177, 179, 180, 181, 182, 185, 187, 188, 193, 194, 199, 213, 214, etc.

[0117] Examples of blue pigments include CIPigmentBlue1, 2, 15, 15:1, 15:2, 15:3, 15:4, 15:6, 16, 22, 60, 64, 66, 79, 79, and 80.

[0118] Other pigments include, for example, CIPigmentOrange2, 5, 13, 16, 17:1, 31, 34, 36, 38, 43, 46, 48, 49, 51, 52, 55, 59, 60, 61, 62, 64, 71, 73; CIPigmentGreen7, 10, 36, 37, 58, 59, 62, 63; CIPigmentViolet1, 19, 23, 27, 32, 37, 42; CIPigmentBrown 25, 28; CIPigmentBlack1; Examples include CIPigmentWhite1, 2, 4, 5, 7, 11, 12, 18, 19, 21, 22, 23, 26, 27, and 28.

[0119] Among these, CIPigmentRed31, 48:1, 48:2, 48:3, 48:4, 57:1, 122, 146, 147, 148, 150, 170, 176, 177, 184, 185, 202, 242, 254, 255, 264, 266, 269; CIPigmentYellow12, 13, 14, 17, 74, 83, 108, 109, 120, 150, 151, 154, 155, 180, 185, 213; CIPigmentOrange34, 36, 38, 43, 64, 73; CIPigmentGreen7, 36, 37, 58, 62, 63; CIPigmentBlue15:1, 15:3, 15:6, 16, 22, 60, 66; CIPigmentViolet19, 23, 32; CIPigmentBrown25; CIPigmentBlack1 is preferred.

[0120] Other inorganic pigments include carbon black, carbon nanotubes, metal oxides, metal complexes, and other inorganic pigments. Examples of carbon black include furnace black, thermal lamp black, acetylene black, and channel black. Examples of metal oxides include titanium dioxide, iron oxide, iron hydroxide, zirconia, and alumina. Examples of other inorganic pigments include ultramarine, lead yellow, zinc sulfide, and cobalt blue.

[0121] Disperse dyes are preferred. Disperse dyes are dyes that sublimate upon heating. Disperse dyes include CI Disperse Yellow 3, 7, 8, 23, 39, 51, 54, 60, 71, 86; CI Disperse Orange 1, 1:1, 5, 20, 25, 25:1, 33, 56, 76; CI Disperse Brown 2; CI Disperse Red 11, 50, 53, 55, 55:1, 59, 60, 65, 70, 75, 93, 146, 158, 190, 190:1, 2 Examples include 07, 239, 240, 343; CI Bat Red 41; CI Disperse Violet 8, 17, 23, 27, 28, 29, 36, 57; CI Disperse Blue 19, 26, 26:1, 35, 55, 56, 58, 60, 64, 64:1, 72, 72:1, 81, 81:1, 91, 95, 108, 131, 141, 145, 165, 359, 360, etc.

[0122] Colorants can be used alone or in combination of two or more types.

[0123] The average primary particle size of the colorant is usually preferably 5 to 300 nm. The average primary particle size is the arithmetic mean of approximately 20 particles selected from magnified images taken using a transmission electron microscope at a range of 2,000 to 100,000x magnification. If the particles are elliptical, the length of the major axis is used.

[0124] The colorant content is preferably 1 to 30% by mass, and more preferably 1 to 15% by mass, relative to the non-volatile content of the water-based ink. By keeping the colorant content within the above range, storage stability is improved and vivid colors can be obtained.

[0125] The resin for the ink is prepared by adding a colorant to a mixture of a basic compound and water, and then mixing and stirring. Next, a dispersion treatment is performed to create a colorant dispersion. Then, a binder resin and other materials are added to the colorant dispersion and mixed by stirring to produce a water-based ink. It goes without saying that the timing of adding each material is arbitrary, and the dispersion treatment can be performed multiple times.

[0126] The aforementioned dispersion process can utilize the following dispersion devices: high-speed mixers, homogenizers, high-pressure homogenizers, Silverson mixers, planetary mixers, Trimix, kneaders, extruders, horizontal sand mills, vertical sand mills, ball mills, two-roll mills, three-roll mills, bead mills, nanomizers, dispersers equipped with ultrasonic oscillators, high-pressure dispersers, opposing impact dispersers, oblique impact dispersers, batch-type rotor stators, in-line rotor stators, etc. Among these, bead mills are preferred. Commercially available bead mills include, for example, Supermills, sand grinders, agitator mills, Glenmills, Dynomills, Pearlmills, and Cobolmills.

[0127] It is preferable to perform a micronization treatment on the colorant before the dispersion treatment. This makes the primary particle size of the colorant finer, resulting in a dispersion with a finer volume-average particle size D50 (median diameter) of colorant particles. The micronization treatment is preferably performed by coating the colorant with a dispersion resin using the salt milling method. The salt milling method is a process in which a water-soluble solvent, a water-soluble inorganic salt (e.g., sodium chloride), a colorant, and a dispersion resin are kneaded to coat the surface of the colorant with the dispersion resin, and then the water-soluble inorganic salt and water-soluble solvent are removed. Examples of kneading equipment used in the salt milling method include a kneader, a two-roll mill, a three-roll mill, a ball mill, an attritor, a horizontal sand mill, a vertical sand mill, and / or an annular bead mill. Among these, a kneader is preferred because it can efficiently coat the surface of the colorant. The kneading conditions can be adjusted as appropriate depending on the type of colorant, the degree of micronization, etc. Heating or cooling can also be performed as needed.

[0128] The D50 average particle diameter (median diameter) of the colorant dispersion is preferably 20 to 200 nm, more preferably 25 to 150 nm, even more preferably 30 to 130 nm, and particularly preferably 35 to 90 nm. The D50 average particle diameter is measured by dynamic light scattering (for example, Microtrac-Bell's "Nanotrac UPA-EX150") under conditions of 25°C. The above "particle diameter" refers to the volume-based median diameter measured by dynamic light scattering.

[0129] <Water-soluble solvent> Examples of water-soluble solvents include polyhydric alcohols, polyhydric alcohol alkyl ethers, polyhydric alcohol aryl ethers, nitrogen-containing heterocyclic compounds, amides, amines, sulfur-containing compounds, propylene carbonate, ethylene carbonate, and other water-soluble solvents.

[0130] Polyhydric alcohols include, for example, glycerin, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, 1,2-propanediol, 1,3-propanediol, dipropylene glycol, tripropylene glycol, polypropylene glycol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,2-pentanediol, 1,3-pentanediol, 1,4-pentanediol, 1,5-pentanediol, 1,2-hexanediol, 1,3-hexanediol, 1,4-hexanediol, 1,5-hexanediol, 1,6 Examples include -hexanediol, 3-methyl-1,3-butanediol, trimethylolethane, trimethylolpropane, 1,2,6-hexanetriol, 1,2,4-butanetriol, 1,2,3-butanetriol, petriol, 2-ethyl-2-methyl-1,3-propanediol, 3,3-dimethyl-1,2-butanediol, 2,2-diethyl-1,3-propanediol, 2-methyl-2-propyl-1,3-propanediol, 2,4-dimethyl-2,4-pentanediol, 2,5-dimethyl-2,5-hexanediol, 5-hexen-1,2-diol, and 2-ethyl-1,3-hexanediol. Among these, 2-ethyl-1,3-hexanediol, 2,2,4-trimethyl-1,3-pentanediol, 1,2-propanediol, 1,2-butanediol, 1,3-butanediol, 1,2-pentanediol, 1,5-pentanediol, 1,2-hexanediol, 1,6-hexanediol, and 1,2-heptanediol are preferred.

[0131] Examples of polyhydric alcohol alkyl ethers include ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, propylene glycol monoethyl ether, and propylene glycol monobutyl ether. Examples of polyhydric alcohol aryl ethers include ethylene glycol monophenyl ether, diethylene glycol monophenyl ether, tetraethylene glycol chlorophenyl ether, ethylene glycol monobenzyl ether, and ethylene glycol monoallyl ether.

[0132] Examples of nitrogen-containing heterocyclic compounds include 2-pyrrolidone, N-methyl-2-pyrrolidone, N-hydroxyethyl-2-pyrrolidone, 1,3-dimethylimidazolidinone, ε-caprolactam, and γ-butyrolactone. Examples of amides include formamide, N-methylformamide, and N,N-dimethylformamide. Examples of amines include monoethanolamine, diethanolamine, triethanolamine, monoethylamine, diethylamine, and triethylamine. Examples of sulfur-containing compounds include dimethyl sulfoxide, sulfolane, and thiodiethanol.

[0133] Water-soluble solvents can be used alone or in combination of two or more types.

[0134] The water-soluble solvent content is preferably 3 to 60% by mass, and more preferably 3 to 50% by mass, in the water-based ink. The water content is preferably 10 to 90% by mass, and more preferably 30 to 80% by mass, in the water-based ink.

[0135] <Binder resin> The binder resin can be the ink resin specified herein or the following binder resins.

[0136] Examples of binder resins include (meth)acrylic resin, styrene-(meth)acrylic resin, polyurethane resin, styrene-butadiene resin, vinyl chloride resin, polyolefin resin, polyester resin, polyurethane resin, alkyd resin, fluororesin, silicone-containing resin, and the like.

[0137] The binder resin content is preferably 1 to 30% by mass, and more preferably 3 to 20% by mass, relative to the non-volatile content of the water-based ink.

[0138] The water-based inks of this specification may further contain additives. Examples of additives include surfactants, defoamers, waxes, humectants, and preservatives. The total content of additives is preferably 0.05 to 20% by mass, and more preferably 0.2 to 10% by mass, in the water-based ink.

[0139] <Ink manufacturing method> The present invention describes a method for producing an aqueous ink. However, the production method is not limited to the following. Water-based inks are manufactured by stirring and mixing a colorant, a water-soluble solvent, and water, along with binder resins, surfactants, and other additives as needed. During manufacturing, stirring and mixing may be done while heating to a temperature of 40-100°C as needed.

[0140] (Removal of coarse particles) Coarse particles contained in the ink are preferably removed by means of filtration, centrifugation, or other methods. For filtration, it is preferable to use a membrane filter to suction filter the ink and separate the coarse particles. The filter pore size is not particularly limited as long as it can remove coarse particles and dust, but is preferably 0.3 to 5 μm, more preferably 0.5 to 3 μm.

[0141] <Inkjet Ink> The water-based inks described herein are preferably used for inkjet ink applications.

[0142] Preferred water-soluble solvents for use in inkjet inks include, for example, 2-ethyl-1,3-hexanediol, 2,2,4-trimethyl-1,3-pentanediol, 1,2-propanediol, 1,2-butanediol, 1,3-butanediol, 1,2-pentanediol, 1,5-pentanediol, 1,2-hexanediol, 1,6-hexanediol, and 1,2-heptanediol.

[0143] The content of the resin for the ink is preferably 1 to 30% by mass, and more preferably 2 to 20% by mass, of the non-volatile content of the inkjet ink.

[0144] Ink resins can be used alone or in combination of two or more types.

[0145] Inkjet inks may contain additives as needed. Examples of additives include surfactants, defoamers, waxes, humectants, and preservatives. The total content of additives in the inkjet ink is preferably 0.05 to 10% by mass, and more preferably 0.2 to 5% by mass.

[0146] Wax is a resin that is solid at room temperature (25°C) and melts at temperatures between 40 and 200°C (i.e., has a melting point). Generally, wax has low affinity for water and tends to be concentrated at the gas-liquid interface, so it remains present on the surface of printed materials even after printing. As a result, the blocking resistance of printed materials is significantly improved.

[0147] Examples of waxes include plant and animal-based waxes such as carnauba wax, candelilla wax, beeswax, rice wax, and lanolin; petroleum-based waxes such as paraffin wax, microcrystalline wax, polyethylene wax, oxidized polyethylene wax, and petrolatum; mineral-based waxes such as montane wax and ozokerite; synthetic waxes such as carbon wax, Hoechst wax, polyolefin wax, and stearic acid amide; and natural and synthetic wax emulsions such as α-olefin / maleic anhydride copolymers. Among these, polyolefin waxes (e.g., polyethylene wax, polypropylene wax) and paraffin wax are preferred from the viewpoint of durability. Waxes can be used individually or in mixtures of two or more types.

[0148] The melting point of the wax is preferably 80 to 180°C, and more preferably 100 to 160°C, from the standpoint of not adversely affecting the storage stability of the inkjet ink and having good redispersibility.

[0149] The wax exists in the inkjet ink either dissolved (water-soluble resin) or dispersed (resin microparticles). The latter is particularly preferred because it easily prevents blocking of printed materials, does not interact easily with the dispersed resin, thus not deteriorating the storage stability of the inkjet ink, and can fill voids on the paper surface, resulting in a particularly improved print density on uncoated paper. In this specification, "water-soluble resin" refers to a 1% by mass aqueous solution of the resin in question that is transparent to the naked eye at 25°C. "Resin microparticles" refers to a resin other than a water-soluble resin, whose D50 average particle size, measured using the same apparatus and method as for the colorants described above, is between 5 and 1,000 nm.

[0150] When resin fine particles are used as the wax, the average particle size of the D50 is preferably 10 to 200 nm, more preferably 20 to 150 nm, and even more preferably 30 to 100 nm, from the viewpoint of ensuring the storage stability of the inkjet ink, as well as improving the print density of the printed material and preventing blocking.

[0151] The aforementioned humectant is preferably a sugar. Examples of such sugars include monosaccharides, disaccharides, oligosaccharides (including trisaccharides and tetrasaccharides), and polysaccharides. Examples of monosaccharides include glucose, mannose, fructose, ribose, xylose, arabinose, and galactose. Examples of disaccharides include maltose, cellobiose, lactose, sucrose, and trehalose. Examples of oligosaccharides include maltotriose. Examples of polysaccharides include α-cyclodextrin and cellulose. Furthermore, derivatives of these sugars, such as reducing sugars of the aforementioned sugars (for example, sugar alcohols [general formula: HOCH2(CHOH)] n Examples include CH2OH (where n is an integer from 2 to 5), oxidized sugars (e.g., aldonic acid, uronic acid), amino acids, thioacids, etc. Among these, sugar alcohols are preferred, and maltitol and sorbitol are preferred.

[0152] Inkjet inks can be used in various inkjet printers. Examples of inkjet methods include continuous jet types such as charge-controlled and spray types, and on-demand types such as piezo, thermal, and electrostatic attraction types.

[0153] <Multi-color ink set> The multi-color ink set of the present invention is an ink set containing two or more inks of different colors. Of the two or more inks, at least one ink contains the ink resin specified herein. The colors included in the ink set are selected from two or more colors from cyan, magenta, yellow, black, and white. Alternatively, an ink set may be selected from two or more colors from red, green, blue, and orange. It goes without saying that the ink set can also use inks of colors other than cyan, magenta, yellow, black, white, red, green, blue, and orange. Examples of ink sets include inkjet ink sets and flexographic printing ink sets.

[0154] <Manufacturing methods for printed materials> The printed material of the present invention preferably comprises a substrate and a printed layer formed from the aqueous ink of the present invention. Examples of the aforementioned substrates include paper substrates and plastic substrates. Paper substrates are broadly classified into coated papers such as coated paper, art paper, cast paper, and lightly coated paper, as well as uncoated papers such as fine paper and foam paper. Coated paper has a coating agent applied to it, resulting in a smooth printing surface, while uncoated paper has no coating agent applied, resulting in a rough surface, and the ink absorption of the two differs significantly. Examples of plastic substrates include polyvinyl chloride sheets, polyester films, polypropylene films, and polyethylene films. The substrate may also be a laminate formed by layering multiple materials. Other examples include resin-coated photographic paper and synthetic paper (e.g., Yupo®, a registered trademark).

[0155] The thickness of the substrate is approximately 20 to 300 μm, and the basis weight of the substrate is 30 to 300 g / m². 2 It is to that extent. The thickness of the printed layer is preferably 0.01 to 5 μm, more preferably 0.1 to 4 μm, and even more preferably 0.5 to 3 μm. By setting the thickness of the printed layer within the above range, it is possible to obtain sufficient color development as a printed material while sufficiently evaporating the solvent during the drying process when the printed layer is made, thereby forming a strong film. The aforementioned printed layer can be formed using a printing press compatible with each ink, such as an inkjet printer, flexographic printer, gravure printer, or offset printer. After printing with ink, a drying process can be added as needed. Examples of dryers used in the drying process include hot air dryers and infrared heaters.

[0156] Printed materials have various uses, including flyers, books, magazines, cardboard boxes, paper packaging, food packaging, and labels. [Examples]

[0157] The present invention will be described in more detail below with reference to examples and comparative examples. However, the present invention is not limited to the examples. Hereinafter, unless otherwise specified, "parts" refers to "parts by mass" and "%" refers to "percentage by mass".

[0158] (Acid value) The number of moles of acid groups contained in 1 g of dispersed resin was calculated from the monomer composition. Assuming that this number of moles of acid groups is equal to the number of moles of potassium hydroxide (molecular weight 56.1) required for neutralization, the theoretical value of the acid value (mgKOH / g) was calculated.

[0159] Table 1 shows the living polymerization agents used in the synthesis of the resin for the ink.

[0160] [Table 1]

[0161] <Manufacturing of resins for inks> (Example 1 (Ink Resin 1)) In a reaction vessel equipped with a gas inlet tube, thermometer, condenser, and stirrer, 200 parts water, 0.7 parts (0.012 mol) of potassium hydroxide, and 1.5 parts (0.006 mol) of RAFT agent compound 1 were charged. After purging with nitrogen gas, the reaction vessel was heated and stirred at 80°C for 1 hour to neutralize and dissolve the RAFT agent. Then, while stirring, 0.5 parts (0.002 mol) of 4,4'-azibis(4-cyanopentanoic acid), 5.0 parts (0.058 mol) of methacrylic acid, 5.0 parts (0.048 mol) of styrene, and 5.0 parts (0.050 mol) of methyl methacrylate were added dropwise to the reaction vessel over 3 hours to carry out polymerization and synthesize block A. Subsequently, 0.5 parts (0.002 mol) of 4,4'-azobis(4-cyanopentanoic acid) and 85.0 parts (0.849 mol) of methyl methacrylate were added dropwise over 3 hours to carry out polymerization and synthesize block B. After confirming that the polymerization conversion rate reached 95-100%, the reaction temperature was lowered to 60°C. Next, potassium hydroxide was added so that the neutralization rate of the acid group-containing monomer units reached 100%, and deionized water was added so that the non-volatile content was 30%. The mixture was stirred at 50°C for 1 hour to obtain ink resin 1.

[0162] (Examples 2-33, 35-37 (Ink resins 2-33, 35-37)) The synthesis was carried out in the same manner as in Example 1, except that the raw materials and preparation amounts were changed as shown in Tables 2-1 to 2-8, to obtain the ink resins 2-33 and 35-37 of Examples 2-33 and 35-37, respectively.

[0163] (Example 34 (Ink Resin 34)) In a reaction vessel equipped with a gas inlet tube, thermometer, condenser, and stirrer, 100 parts water, 100 parts MEK, and 2.5 parts (0.006 mol) of RAFT compound 4 were charged. After purging with nitrogen gas, the reaction vessel was heated and stirred at 80°C for 1 hour. While stirring, 0.5 parts (0.002 mol) of 4,4'-azibis(4-cyanopentanoic acid), 5.0 parts (0.058 mol) of methacrylic acid, 5.0 parts (0.024 mol) of sodium p-styrenesulfonate, 7.5 parts (0.072 mol) of styrene, and 7.5 parts (0.075 mol) of methyl methacrylate were added dropwise over 3 hours to synthesize block A. After that, MEK was removed by distillation, and 100 parts of water were added. Subsequently, 0.5 parts (0.002 mol) of 4,4'-azobis(4-cyanopentanoic acid), 40.0 parts (0.384 mol) of styrene, 34.0 parts (0.340 mol) of methyl methacrylate, and 1.0 part (0.008 mol) of allyl methacrylate were added dropwise over 3 hours to synthesize block B. After confirming that the polymerization conversion rate reached 95-100%, the reaction temperature was lowered to 60°C. Next, potassium hydroxide was added so that the neutralization rate of the uninterrupted acid group-containing monomer units reached 100%, and deionized water was added so that the non-volatile content was 30%. The mixture was stirred at 50°C for 1 hour to obtain ink resin 34.

[0164] (Example 38 (Ink Resin 38)) In a reaction vessel equipped with a gas inlet tube, thermometer, condenser, and stirrer, 200 parts water, 1.3 parts (0.024 mol) of potassium hydroxide, and 3.0 parts (0.012 mol) of RAFT compound 1 were charged. After purging with nitrogen gas, the reaction vessel was heated and stirred at 80°C for 1 hour to neutralize and dissolve the RAFT agent. Then, while stirring, 0.5 parts (0.002 mol) of 4,4'-azibis(4-cyanopentanoic acid), 1.0 part (0.012 mol) of methacrylic acid, 1.0 part (0.005 mol) of sodium p-styrenesulfonate, 40.0 parts (0.384 mol) of styrene, 34.0 parts (0.340 mol) of methyl methacrylate, and 1.0 part (0.008 mol) of allyl methacrylate were added dropwise to the reaction vessel over 3 hours to carry out polymerization and synthesize block B. Subsequently, 0.5 parts (0.002 mol) of 4,4'-azobis(4-cyanopentanoic acid), 4.0 parts (0.046 mol) of methacrylic acid, 4.0 parts (0.019 mol) of sodium p-styrene sulfonate, 7.5 parts (0.072 mol) of styrene, and 7.5 parts (0.075 mol) of methyl methacrylate were added dropwise over 3 hours to carry out polymerization and synthesize block A. After confirming that the polymerization conversion rate reached 95-100%, the reaction temperature was lowered to 60°C. Next, potassium hydroxide was added so that the neutralization rate of the acid group-containing monomer units reached 100%, and deionized water was added so that the non-volatile content was 30%. The mixture was stirred at 50°C for 1 hour to obtain ink resin 38.

[0165] (Comparative Example 1 (Ink Resin 39)) In a reaction vessel equipped with a gas inlet tube, thermometer, condenser, and stirrer, 200 parts water, 0.7 parts (0.012 mol) of potassium hydroxide, and 1.5 parts (0.006 mol) of 2-({[(2-carboxyethyl)sulfanyl]carbonothioyl}sulfanyl)propanoic acid were charged. After purging with nitrogen gas, the reaction vessel was heated and stirred at 80°C for 1 hour to neutralize and dissolve the RAFT agent. Then, while stirring, 0.5 parts (0.002 mol) of 4,4'-azibis(4-cyanopentanoic acid), 7.5 parts (0.075 mol) of methyl methacrylate, 7.5 parts (0.072 mol) of styrene, and 10.0 parts (0.077 mol) of hydroxyethyl methacrylate were added dropwise over 3 hours to synthesize Block A. Subsequently, 0.5 parts (0.002 mol) of 4,4'-azibis(4-cyanopentanoic acid), 40.0 parts (0.384 mol) of styrene, 34.0 parts (0.340 mol) of methyl methacrylate, and 1.0 part (0.008 mol) of allyl methacrylate were added dropwise over 3 hours to synthesize block B. After confirming that the polymerization conversion rate reached 95-100%, the reaction temperature was lowered to 60°C. Then, deionized water was added to reduce the non-volatile content to 30%, and the mixture was stirred at 50°C for 1 hour to obtain ink resin 39.

[0166] (Comparative Example 2 (Ink Resin 40)) In a reaction vessel equipped with a gas inlet tube, thermometer, condenser, and stirrer, 200 parts of water and 2.5 parts of Aqualon KH-10 (ammonium polyoxyethylene-1-(allyloxymethyl)alkyl ether sulfate, 99% active ingredient, manufactured by Daiichi Kogyo Seiyaku) were charged. After purging with nitrogen gas, the reaction vessel was heated and stirred at 80°C for 1 hour. While stirring, 0.5 parts (0.002 mol) of 4,4'-azobis(4-cyanopentanoic acid), 5.0 parts (0.058 mol) of methacrylic acid, 5.0 parts (0.024 mol) of sodium p-styrene sulfonate, 7.5 parts (0.072 mol) of styrene, and 7.5 parts (0.075 mol) of methyl methacrylate were added dropwise over 3 hours to synthesize Block A. Subsequently, 0.5 parts (0.002 mol) of 4,4'-azibis(4-cyanopentanoic acid), 40.0 parts (0.384 mol) of styrene, 34.0 parts (0.340 mol) of methyl methacrylate, and 1.0 part (0.008 mol) of allyl methacrylate were added dropwise over 3 hours to synthesize block B. After confirming that the polymerization conversion rate reached 95-100%, the reaction temperature was lowered to 60°C. Then, deionized water was added to reduce the non-volatile content to 30%, and the mixture was stirred at 50°C for 1 hour to obtain ink resin 40.

[0167] [Table 2-1]

[0168] [Table 2-2]

[0169] [Table 2-3]

[0170] [Table 2-4]

[0171] [Table 2-5]

[0172] [Table 2-6]

[0173] [Table 2-7]

[0174] [Table 2-8]

[0175] The abbreviations for the monomers listed in Table 2 are as follows: • MAA: Methacrylic acid • NASS: Sodium p-styrene sulfonate HPM: 2-Methacloroxyethyl acid phosphate • ESM: Sodium 2-(methacryloyloxy)ethanesulfonate St: Styrene BzMA: Benzyl methacrylate CHMA: Cyclohexyl methacrylate IBXMA: Isobornyl methacrylate MMA: Methyl methacrylate BA: Butyl acrylate LMA: Lauryl methacrylate • AMA: Allyl methacrylate • DAP: Diallylphthalate • EDMA: Ethylene glycol dimethacrylate • TPM: 3-(trimethoxysilyl)propyl methacrylate • DAAM: Diacetone acrylamide • NBA: Nn-Butoxymethylacrylamide • HEMA: Hydroxyethyl methacrylate

[0176] In Table 2, "ND" indicates that measurement is not possible. Ink resins containing cross-linked monomers have high molecular weights or are gel-like in nature, exceeding the measurement limits of GPC, making molecular weight measurement by GPC impossible.

[0177] <Dispersion manufacturing> (Manufacturing of Dispersion Set 1) 20 parts of Printex85 (carbon black, Orion Engineered Carbons) as the colorant K, 20 parts of an aqueous solution of water-soluble styrene-acrylic resin (styrene:acrylic acid:behenyl methacrylate = 35:30:35 (mass ratio) random polymer, weight-average molecular weight: 16,000, acid value: 250 mgKOH / g) (non-volatile content 30%) as the pigment dispersion resin, 15 parts of methyl ethyl ketone, and 45 parts of water were mixed and premixed with a stirrer. The main dispersion was then carried out using a 0.6 L volume Dynomyl container filled with 1800 parts of 0.5 mm diameter zirconia beads. Subsequently, 100 parts of water were added, and 100 parts of the solution were removed by vacuum distillation using an evaporator to obtain a dispersion. Then, dispersion set 1 (K, C, M, Y) was obtained by using the same method except that the pigments were changed as described below. Colorant C is Cyan: Toyo Color Co., Ltd. LIONOGEN BLUE FG-7358G (CIPigment Blue 15:3) Colorant M: Magenta: TOSHIKI RED150TR (CI Pigment Red 150) manufactured by Tokyo Shikizai Co., Ltd. Colorant Y is yellow: LIONOL YELLOW TT1405G (CI Pigment Yellow 14) manufactured by Toyo Color Co., Ltd.

[0178] <Manufacturing of inkjet ink sets> (Inkjet ink set 1 manufacturing) From the obtained dispersion set 1, 25.0 parts of the black dispersion, 20.0 parts of propylene glycol, 5.0 parts of 1,2-hexanediol, 20.0 parts of ink resin 1, 25.95 parts of deionized water, 0.1 parts of Surfinol DF110D (manufactured by Air Products Japan) and 0.5 parts of BYK-348 (manufactured by BYK) as leveling agents, 0.5 parts of triethanolamine as a pH adjuster, 2.9 parts of AQUACER515 (manufactured by BYK) as a wax, and 0.05 parts of Proxel GXL(s) (manufactured by Arch Chemical) as a preservative were mixed to obtain a black inkjet ink. Inkjet ink set 1 (K, C, M, Y) was obtained by using the same method except that the color of the dispersion used in dispersion set 1 was changed. AQUACER515: BYK polyethylene wax (resin microparticles), melting point 135°C, non-volatile content 35%

[0179] <Manufacturing of inkjet ink sets 2-40> Inkjet ink sets 2 through 40 were obtained by performing the same procedure as for inkjet ink set 1, except that ink resin 1 in inkjet ink set 1 was changed to ink resins 2 through 40.

[0180] <Manufacturing of printed materials> (Manufacturing of printed material 1) The obtained inkjet ink set 1 was loaded into an inkjet printer (Seiko Epson, model number: EM-930C, piezo type), and full-surface solid printing (fine mode) was performed on a PET film (Tamura Chemical, FE2001, 12 μm thick) using black ink, cyan ink, magenta ink, and yellow ink. Immediately after printing, the printed material was placed in a 70°C air oven and dried for 5 minutes to obtain printed material 1.

[0181] <Manufacturing of printed materials 2-40> Printed materials 2-40 were obtained in the same manner as printed material 1, except that the inkjet inks used were changed to 2-40.

[0182] <Examples 1-114, Comparative Examples 1-6> The obtained inkjet inks and printed materials were evaluated using the following evaluations 1-4.

[0183] <Evaluation 1: Redistribution assessment> The redispersibility of the obtained inkjet inks, black (hereinafter also referred to as K), cyan (hereinafter also referred to as C), magenta (hereinafter also referred to as M), and yellow (hereinafter also referred to as Y), was evaluated as follows. 10 μL of inkjet ink was dropped onto an aluminum dish and left to stand in a 40°C incubator for 2 hours to evaporate and solidify the water-based ink. After the predetermined time had elapsed, 1 mL of redispersibility cleaner was dropped, and the solid was visually confirmed after 1 minute. Further evaluations were also performed using the same procedure, but with standing times of 4 hours, 8 hours, and 12 hours in the 40°C incubator. Ink that can be redispersed even after standing for a long time means that even if it dries and hardens on the inkjet head, it can be printed as usual by treating it with a cleaner. The evaluation criteria were as follows. A score of 2 or higher was considered to be in the usable range. 5: In each of the K, C, M, and Y colors, the solid matter remained uniformly redispersed even after standing for 12 hours. 4: In each of the K, C, M, and Y colors, the solid matter was uniformly redispersed after 8 hours of standing, but not after 12 hours of standing. 3: In each of the K, C, M, and Y colors, the solid matter was uniformly redispersed after 4 hours of standing, but not after 8 hours of standing. 2: In each of the K, C, M, and Y colors, the solid matter was uniformly redispersed after 2 hours of standing, but not after 4 hours of standing. 1: In each of the K, C, M, and Y colors, the solid content did not redisperse at any settling time.

[0184] <Evaluation 2: Coarse grain content evaluation> The amount of coarse particles in the obtained inkjet inks K, C, M, and Y was evaluated as follows. Specifically, it was evaluated by measuring the passage time of a fixed amount of inkjet ink through a 25mmφ glass fiber filter (manufactured by GF / BGE Healthcare Life Sciences). If there are many coarse particles, the filter will clog and a longer passage time will be observed. Furthermore, if there are even more coarse particles, the filter will become blocked and the entire amount of inkjet ink cannot be filtered. The evaluation conditions are as follows. A 25mm diameter filter holder (manufactured by ADVANTEC) with a funnel marked with a 15ml scale and a 25mmφ glass fiber filter (manufactured by GF / BGE Healthcare Life Sciences) is placed on a suction vessel equipped with a vacuum pump via a stopcock. The vacuum pump is operated using a stopcock to prevent the inside of the suction vessel from becoming depressurized. 15g of the colorant dispersion is weighed into the funnel. Starting with the opening of the pump and suction vessel, the time it takes for the entire amount of colorant dispersion to pass through the filter is measured. The pressure inside the suction vessel at this time is 0.05 MPa to 0.07 MPa. A score of 2 or higher was considered to be within the practical range. 5: Filtration can be completed in less than 20 seconds for each color: K, C, M, and Y. 4: Filtration can be performed in 20 seconds or more but less than 30 seconds for each of the K, C, M, and Y colors. 3: Filtration can be performed in 30 seconds or more but less than 45 seconds for each of the K, C, M, and Y colors. 2: Filtration can be performed in 45 seconds or more but less than 60 seconds for each of the K, C, M, and Y colors. 1: For each of the K, C, M, and Y colors, filtration is not possible in less than 60 seconds.

[0185] <Evaluation 3: Storage Stability Evaluation> The storage stability of the obtained inkjet inks K, C, M, and Y was evaluated as follows. The inkjet inks were stored in a constant temperature chamber at 70°C and accelerated over time, and the viscosity change of the inkjet inks before and after the time period was evaluated. Viscosity was measured using an E-type viscometer (TVE-20L, standard cone, manufactured by Toki Sangyo Co., Ltd.) at 25°C and a rotation speed of 50 rpm, and the value after 1 minute was taken as the viscosity value. The evaluation criteria were as follows. A score of 2 or higher was considered to be in the usable range. 5: For each color (K, C, M, Y), the viscosity change rate after four weeks of storage is less than ±10%. 4: For each color (K, C, M, Y), the viscosity change rate after two weeks of storage is less than ±10%. 3: For each color (K, C, M, Y), the viscosity change rate after one week of storage is less than ±10%. 2: For each of the K, C, M, and Y colors, the viscosity change rate after one week of storage should be between ±10% and 20%. 1: For each color (K, C, M, Y), the viscosity change rate after one week of storage exceeds ±20%.

[0186] <Rating 4: Durability Rating> Inkjet inks K, C, M, and Y obtained in the examples and comparative examples were loaded into an inkjet printer (Seiko Epson, model number: EM-930C, piezo type) and 100% solid images were printed onto PET film (Tamura Chemical Co., Ltd., FE2001, 12 μm thick). The resulting prints were evaluated using the Kanakin No. 3 (abrasion resistance) tester AB-301 (Tester Sangyo Co., Ltd.) under conditions of a load of 500 g and 30 friction cycles (back and forth). They were also evaluated using Kanakin No. 3 (water resistance) with water added under the same conditions. Furthermore, they were evaluated using Kanakin No. 3 (solubility resistance) with ethanol added under the same conditions. The surface condition of the images on the prints after testing was visually observed and evaluated according to the following criteria. A score of 2 or higher was considered to be in the usable range. 5: In each of the K, C, M, and Y colors, there is no scratching or peeling of the printed surface in terms of abrasion resistance, water resistance, and solvent resistance. 4: For each of the K, C, M, and Y colors, the scratch and ink peeling rate on the printed surface is less than 5% in terms of abrasion resistance, water resistance, and solvent resistance. 3: For each of the K, C, M, and Y colors, the scratching and ink peeling of the printed surface is between 5% and 15% in terms of abrasion resistance, water resistance, and solvent resistance. 2: For each of the K, C, M, and Y colors, the rate of scratching or ink peeling on the printed surface is 15% or more but less than 30% in terms of abrasion resistance, water resistance, and solvent resistance. 1: For each color (K, C, M, Y), the abrasion resistance, water resistance, and solvent resistance are such that the scratching and ink peeling of the printed surface is 30% or more.

[0187] The evaluation results for the examples and comparative examples are shown in Table 3 below.

[0188] [Table 3-1]

[0189] [Table 3-2]

[0190] The results in Tables 3-1 and 3-2 show that using the ink resin in the examples resulted in good storage stability and redispersibility, with fewer coarse particles. Furthermore, tests on printed materials confirmed that excellent durability was obtained when using non-absorbent substrates. On the other hand, using the ink resin of the comparative example does not solve the problem of the present invention.

Claims

1. An ink resin of the polymer shown in the following general formula (1), The aforementioned Block A contains an acidic group-containing monomer unit, The aforementioned B block is an ink resin comprising one or more units selected from the group consisting of aromatic ring-containing monomer units, aliphatic ring-containing monomer units, (meth)acrylate alkyl ester units, and crosslinkable monomer units. General formula (1) 【Chemistry 1】 [In general formula (1), Polymer represents an A-B block polymer, and a portion of the A-B block polymer may be substituted with a functional group. Z represents an organic group selected from alkyl groups, aryl groups, arylalkyl groups, alkylthio groups, arylthio groups, and arylalkylthio groups, and a portion of the organic group may be substituted.]

2. A polymer represented by the following general formula (2), The aforementioned polymer is an A-B block polymer, The aforementioned Block A contains an acidic group-containing monomer unit, The aforementioned B block is an ink resin comprising one or more units selected from the group consisting of aromatic ring-containing monomer units, aliphatic ring-containing monomer units, (meth)acrylate alkyl ester units, and crosslinkable monomer units. General formula (2) 【Chemistry 2】 [In general formula (2), Polymer represents an A-B block polymer, and a portion of the A-B block polymer may be substituted with a functional group. Z represents an organic group selected from alkyl groups, aryl groups, arylalkyl groups, alkylthio groups, arylthio groups, and arylalkylthio groups, and a portion of the organic group may be substituted. R １ represents an organic group, and the organic group is neutralized by a basic compound -CO ２ H and -SO ３ [Having an acid group selected from H]

3. The ink resin according to claim 1, wherein the monomer unit content of block A is 5.0 to 40.0% by mass of the total monomer units of the A-B block polymer.

4. The resin for ink according to claim 1, wherein the acidic group-containing monomer unit is one or more selected from the group consisting of (meth)acrylic acid units and sulfo group-containing monomer units.

5. The resin for ink according to claim 1, wherein the content of the acidic group-containing monomer units is 0.1 to 25% by mass of the total monomer units of the A-B block polymer.

6. A water-based ink comprising the ink resin, colorant, and water-soluble solvent described in any one of claims 1 to 5.

7. A multi-color ink set comprising the water-based ink described in claim 6.

8. A printed article comprising a substrate and a printed layer formed from the aqueous ink described in claim 6.

9. A method for producing an ink resin of A-B block polymer, comprising the following steps 1 and 2 or 3. The structure shown in the general formula (3) below, and -CO ２ H and -SO ３ Step 1: Mixing a compound having one or more acidic groups selected from the group consisting of H, a basic compound, and water to obtain a mixed solution. Step 2 involves reacting the aforementioned mixture with a solution containing an acidic group-containing monomer and a polymerization initiator to synthesize block A and prepare an aqueous polymer solution, and reacting the aqueous polymer solution with a solution containing one or more monomers selected from the group consisting of aromatic ring-containing monomers, aliphatic ring-containing monomers, alkyl (meth)acrylates and crosslinkable monomer units, and a polymerization initiator to synthesize block B and obtain an aqueous A-B block polymer solution having a site at the end represented by the following general formula (3). Step 3 involves reacting the aforementioned mixture with a solution containing one or more monomers selected from the group consisting of aromatic ring-containing monomers, aliphatic ring-containing monomers, alkyl (meth)acrylates, and crosslinkable monomer units, and a polymerization initiator to synthesize block A and prepare an aqueous polymer solution; reacting the aqueous polymer solution with a solution containing an acidic group-containing monomer and a polymerization initiator to synthesize block B and obtain an aqueous A-B block polymer solution having a site at the end represented by the following general formula (3). General formula (3) 【Transformation 3】 [In general formula (3), Z represents an organic group selected from alkyl groups, aryl groups, arylalkyl groups, alkylthio groups, arylthio groups, and arylalkylthio groups, and a portion of the organic group represented by Z may be substituted. * represents a bond.]

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