JP2023112803A - Aqueous dispersion and aqueous ink - Google Patents

Abstract

To provide a polymer-containing aqueous dispersion that has excellent adhesion to a substrate, particularly an olefinic substrate such as biaxially stretched polypropylene (OPP), without a primer or the like, and also has excellent scratch resistance and water resistance.SOLUTION: An aqueous dispersion comprises a polymer (A) comprising a structural unit derived from a hydroxy group-containing monomer and a crosslinker (B).SELECTED DRAWING: None

Description

The present invention relates to aqueous dispersions. and an aqueous ink containing the aqueous dispersion. The water-based ink of the present invention can be suitably used as, for example, water-based ink for inkjet, ink for flexographic printing, ink for offset printing, ink for lithographic printing, ink for gravure printing, ink for screen printing, and the like. The water-based ink of the present invention is particularly suitable for use as an inkjet water-based ink.

Inks are roughly classified into two types: organic solvent-based inks in which an organic solvent is used as the main component of the solvent, and water-based inks in which water is used as the main component of the solvent.
The organic solvent-based ink composition has good water resistance because the main component of the solvent is the organic solvent. However, the organic solvent-based ink composition is inferior in safety to the human body and generates an odor derived from the organic solvent. Therefore, in recent years, water-based inks have attracted attention.

For example, Patent Document 1 describes 40 to 90% by mass of styrene monomer, 9.6 to 50% by mass of (meth)acrylic acid alkyl ester monomer having an alkyl group having 4 to 12 carbon atoms, and 0.1 to 10% by mass of carboxyl group-containing monomer. %, 0.1 to 10% by mass of an alkoxysilyl group-containing monomer, and 0.1 to 10% by mass of a surfactant monomer. and an aqueous medium.

Patent No. 6115694

In recent years, inkjet recording methods have also been used for resin recording media such as PET (polyethylene terephthalate), PP (polypropylene), PVC (polyvinyl chloride), etc., which have conventionally been printed with solvent-based inks and UV curable inks. is required, and it has been found that the water-based ink described in Patent Document 1 lacks adhesion to a resin-made recording medium.

An object of the present invention is to provide an aqueous dispersion and an aqueous ink which are excellent in adhesion to substrates, especially to olefinic substrates such as biaxially oriented polypropylene (OPP), even without a primer or the like. .

The inventors conducted studies in view of the above problems, and found that an aqueous dispersion containing a polymer (A) having a structural unit derived from a hydroxyl group-containing monomer and a cross-linking agent (B) can be used as an aqueous ink. It has been found that the adhesiveness to substrates when used is excellent, especially to olefinic substrates such as biaxially oriented polypropylene (OPP), and that scratch resistance, water resistance, and image uniformity are also excellent. , completed the present invention.

According to the present invention, a polymer that has excellent adhesion to a substrate, particularly adhesion to an olefinic substrate such as biaxially oriented polypropylene (OPP) without a primer, etc., and also has good scratch resistance and water resistance. Containing aqueous dispersions as well as aqueous inks are provided.

The polymer-containing aqueous dispersion of the present invention is characterized by being an aqueous dispersion containing a polymer (A) having a structural unit derived from a hydroxyl group-containing monomer and a cross-linking agent (B).
Since the aqueous dispersion is used, the water-based ink of the present invention exhibits good adhesion to substrates, particularly adhesion to olefinic substrates such as biaxially oriented polypropylene (OPP) without a primer or the like. It is excellent in scratch resistance, water resistance and image uniformity.

<Polymer (A)>
The polymer (A) of the present disclosure is preferably a polymer having structural units derived from hydroxyl group-containing monomers. By having a structural unit derived from a hydroxyl group-containing monomer, it has excellent adhesion to substrates, especially to olefinic substrates such as biaxially oriented polypropylene (OPP). It can be expected that a good polymer will be obtained.

The structural unit derived from a hydroxyl group monomer of the present disclosure is not limited to a structural unit formed by polymerizing a hydroxyl group monomer, and may be, for example, a structural unit formed by a post-reaction after polymerization. .
As the hydroxyl group-containing monomer of the present disclosure, a monomer having a carbon-carbon double bond is preferable, and a monofunctional hydroxyl group-containing monomer having one carbon-carbon double bond may be used. A polyfunctional hydroxyl group-containing monomer having two or more double bonds may be used, but a monofunctional hydroxyl group-containing monomer is preferred.

Monofunctional hydroxyl group-containing monomers having one carbon-carbon double bond include, for example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 4- Monohydroxyalkyl (meth)acrylates such as hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 2-hydroxy-3-acryloyl-oxypropyl methacrylate; 2-hydroxy-3-phenoxypropyl (meth)acrylate, etc. aromatic ring-containing monohydroxy (meth) acrylate; hydroxy polyethylene oxide mono (meth) acrylate, hydroxy polypropylene oxide mono (meth) acrylate, hydroxy (polyethylene oxide-polypropylene oxide) mono (meth) acrylate, hydroxy (polyethylene oxide-propylene oxide ) mono (meth) acrylate, hydroxy (polyethylene oxide-polytetramethylene oxide) mono (meth) acrylate, hydroxy (polyethylene oxide-tetramethylene oxide) mono (meth) acrylate, hydroxy (polypropylene oxide-polytetramethylene oxide) mono ( meth)acrylates, monohydroxypolyalkylene oxide (meth)acrylates such as hydroxy(polypropylene oxide-polytetramethylene oxide) mono(meth)acrylate; 1,2-dihydroxyethyl (meth)acrylate, 1,2-dihydroxypropyl (meth)acrylate; ) acrylate, 1,2-dihydroxybutyl (meth)acrylate, 1,2-dihydroxy 5-ethylhexyl (meth)acrylate, 1,1-dihydroxyethyl (meth)acrylate, 1,1-dihydroxypropyl (meth)acrylate, 1 , dihydroxyalkyl (meth)acrylates such as 1-dihydroxybutyl (meth)acrylate; dihydroxypolyalkylene oxides such as 1,2-dihydroxypolyethyl oxide (meth)acrylate, 1,2-dihydroxypolypropylene oxide (meth)acrylate, etc. (Meth)acrylate; 1,2,3-trihydroxypropyl (meth)acrylate, 1,2,3-trihydroxybutyl (meth)acrylate, 1,1,2-trihydroxypropyl (meth)acrylate, 1,1 , 2-trihydroxybutyl (meth)acrylate, polyhydroxyalkyl (meth)acrylate having 3 or more hydroxyl groups in the monomer; 1,2,3-trihydroxypropylene glycol (meth) Polyhydroxypolyalkylene oxide (meth)acrylate having 3 or more hydroxyl groups contained in a monomer such as acrylate, 1,1,2-trihydroxypropylene glycol (meth)acrylate; 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate are preferred, 2-hydroxyethyl (meth)acrylate, 4 - hydroxybutyl (meth)acrylate is more preferred.

Examples of polyfunctional hydroxyl group-containing monomers having two or more carbon-carbon double bonds include glycerin di(meth)acrylate, pentaerythritol tri(meth)acrylate, and the like.

These hydroxyl group-containing (meth)acrylates may be used alone or in combination of two or more.

The hydroxyl-containing monomer of the present disclosure is preferably a hydroxyl-containing (meth)acrylate having 1 to 18 carbon atoms from the viewpoint of adhesion and scratch resistance, and a hydroxyl-containing (meth)acrylate having 1 to 14 carbon atoms. More preferred are hydroxyl group-containing (meth)acrylates having 1 to 10 carbon atoms.

The hydroxyl group-containing monomer of the present disclosure may have a structure represented by general formula 1 below.
Formula 1: CH2=CR1COOX
(In the formula, R1 is H or —CH3. X may be a hydroxyl-containing alkyl group having 2 to 6 carbon atoms, more preferably a hydroxyl-containing alkyl group having 2 to 4 carbon atoms.)
The content of the structural unit derived from the hydroxyl group-containing monomer in 100 parts by mass of the polymer (A) of the present disclosure may be 1 part by mass or more, preferably 3 parts by mass or more, from the viewpoint of adhesion and scratch resistance. , more preferably 5 parts by mass or more, more preferably 10 parts by mass or more, may be 40 parts by mass or less, preferably 35 parts by mass or less, and more preferably 30 parts by mass or less.

The polymer (A) of the present disclosure may have structural units derived from monomers other than the structural units derived from the hydroxyl group-containing monomer.

Structural units derived from other monomers are not limited to structural units formed by polymerizing other monomers described below, for example, structural units formed by post-reaction after polymerization. good.
Other monomers include monofunctional monomers and polyfunctional monomers. Monofunctional monomers and polyfunctional monomers may be used alone or in combination.

Monofunctional monomers include (meth)acrylic acid esters having a linear alkyl group, (meth)acrylic acid esters having a branched alkyl group, acid group-containing monomers, and cycloaliphatic group-containing (meth) Acrylates, oxo group-containing monomers, fluorine atom-containing monomers, nitrogen atom-containing monomers, epoxy group-containing monomers, alkoxyalkyl (meth)acrylates, silane group-containing monomers, carbonyl group-containing monomers , aziridinyl group-containing monomers, styrenic monomers, aralkyl (meth)acrylates, addition polymerizable oxazolines, etc., but are not limited to these examples.

Examples of (meth)acrylic acid esters having a linear alkyl group of the present disclosure include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, and (meth)acrylate. Pentyl acrylate, hexyl (meth)acrylate, octyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, lauryl (meth)acrylate, tridecyl (meth)acrylate, (meth)acrylic cetyl acid, stearyl (meth)acrylate, behenyl (meth)acrylate, methoxyethyl (meth)acrylate, ethyl carbitol (meth)acrylate, ethoxypolyethylene glycol (meth)acrylate, aminoethyl (meth)acrylate , chloroethyl (meth)acrylate, trifluoroethyl (meth)acrylate and heptadecafluorooctylethyl (meth)acrylate. ) ethyl acrylate, propyl (meth) acrylate, butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, octyl (meth) acrylate, nonyl (meth) acrylate, (meth) acrylate Decyl acrylate, lauryl (meth)acrylate, tridecyl (meth)acrylate, cetyl (meth)acrylate, stearyl (meth)acrylate, and behenyl (meth)acrylate are preferred, methyl (meth)acrylate, (meth)acrylate ) ethyl acrylate, butyl (meth)acrylate, octyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, and behenyl (meth)acrylate are more preferred.

The (meth)acrylic acid esters having a branched alkyl group of the present disclosure include isopropyl (meth)acrylate, isobutyl (meth)acrylate, s-butyl (meth)acrylate, t-butyl (meth)acrylate, Neopentyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isodecyl (meth)acrylate, isostearyl (meth)acrylate, 3-methoxybutyl (meth)acrylate, methoxytripropylene glycol (meth)acrylate and (meth) hexafluoropropyl acrylate, etc., and from the viewpoint of adhesion and scratch resistance, isobutyl (meth) acrylate, s-butyl (meth) acrylate, t-butyl (meth) acrylate, (meth) ) neopentyl acrylate, 2-ethylhexyl (meth) acrylate, isodecyl (meth) acrylate, isostearyl (meth) acrylate, preferably isobutyl (meth) acrylate, t-butyl (meth) acrylate, (meth) ) 2-ethylhexyl acrylate and isostearyl (meth)acrylate are more preferred.

Acid group-containing monomers of the present disclosure include, for example, (meth)acrylic acid, maleic acid, fumaric acid, crotonic acid, itaconic acid, citraconic acid, maleic anhydride, maleic acid monomethyl ester, maleic acid monobutyl ester, Examples include carboxyl group-containing aliphatic monomers such as monomethyl itaconate, monobutyl itaconate, and vinyl benzoic acid, but the present invention is not limited to these examples. Each of these acid group-containing monomers may be used alone, or two or more of them may be used in combination. Among these acid group-containing monomers, acrylic acid and methacrylic acid are preferred from the viewpoint of improving the dispersion stability, adhesion and scratch resistance of the aqueous dispersion when the polymer (A) is emulsion particles. and itaconic acid are preferred, acrylic acid and methacrylic acid are more preferred.

Monomers having a cycloaliphatic hydrocarbon group include cyclopentyl (meth)acrylate, cyclohexyl (meth)acrylate, t-butylcyclohexyl (meth)acrylate, benzyl (meth)acrylate, isobornyl (meth)acrylate, isobornyl (meth)acrylate, and isobornyl (meth)acrylate. ) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentenyl (meth) acrylate, cyclopentyl (meth) acrylate, cyclohexyl (meth) ) acrylate and isobornyl (meth)acrylate are preferred, and cyclohexyl (meth)acrylate and isobornyl (meth)acrylate are more preferred.
These cycloaliphatic group-containing monomers can be used alone or in combination.

Examples of oxo group-containing monomers of the present disclosure include (di)ethylene glycol (methoxy ) (meth)acrylate and the like, but are not limited to these examples. Each of these oxo group-containing monomers may be used alone, or two or more of them may be used in combination.

Examples of fluorine atom-containing monomers of the present disclosure include fluorine having an ester group having 2 to 6 carbon atoms, such as trifluoroethyl (meth)acrylate, tetrafluoropropyl (meth)acrylate, and octafluoropentyl (meth)acrylate. Atom-containing alkyl (meth)acrylates and the like are included, but are not limited to these examples. These fluorine atom-containing monomers may be used alone, respectively, or two or more of them may be used in combination.

Nitrogen-containing monomers of the present disclosure include, for example, (meth)acrylamide, N-monomethyl(meth)acrylamide, N-monoethyl(meth)acrylamide, N,N-dimethyl(meth)acrylamide, Nn-propyl (Meth)acrylamide, N-isopropyl(meth)acrylamide, methylenebis(meth)acrylamide, N-methylol(meth)acrylamide, N-butoxymethyl(meth)acrylamide, dimethylaminoethyl(meth)acrylamide, N,N-dimethylamino Acrylamide compounds such as propylacrylamide and diacetone acrylamide, nitrogen atom-containing (meth)acrylate compounds such as dimethylaminoethyl (meth)acrylate and diethylaminoethyl (meth)acrylate, N-vinylpyrrolidone, (meth)acrylonitrile, and the like. However, it is not limited only to such examples. Each of these nitrogen atom-containing monomers may be used alone, or two or more of them may be used in combination.

Examples of epoxy group-containing monomers of the present disclosure include epoxy group-containing (meth)acrylates such as glycidyl (meth)acrylate, α-methylglycidyl (meth)acrylate, and glycidyl allyl ether, but only such examples is not limited to These epoxy group-containing monomers may be used alone or in combination of two or more. Among these epoxy group-containing monomers, glycidyl (meth)acrylate is preferred from the viewpoint of improving adhesion and scratch resistance.
Alkoxyalkyl (meth)acrylates of the present disclosure include, for example, methoxyethyl (meth)acrylate, methoxybutyl (meth)acrylate, ethoxybutyl (meth)acrylate, trimethylolpropane tripropoxy (meth)acrylate, etc. It is not limited only to such examples. These alkoxyalkyl (meth)acrylates may be used alone or in combination of two or more.

Silane group-containing monomers of the present disclosure include, for example, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltri(methoxyethoxy)silane, γ-(meth)acryloyloxypropyltrimethoxysilane, 2-styrylethyltrimethoxysilane. , vinyltrichlorosilane, γ-(meth)acryloyloxypropylhydroxysilane, γ-(meth)acryloyloxypropylmethylhydroxysilane, etc., but are not limited to these examples. These silane group-containing monomers may be used alone or in combination of two or more.
Examples of the carbonyl group-containing monomers of the present disclosure include acrolein, borumylstyrene, vinyl ethyl ketone, (meth)acryloxyalkylpropenal, acetonyl (meth)acrylate, diacetone (meth)acrylate, 2-hydroxypropyl ( meth)acrylate acetylacetate, butanediol-1,4-acrylate acetylacetate, 2-(acetoacetoxy)ethyl (meth)acrylate and the like, but are not limited to these examples. These carbonyl group-containing monomers may be used alone or in combination of two or more.

The aziridinyl group-containing monomers of the present disclosure include, for example, (meth)acryloylaziridine, 2-aziridinylethyl (meth)acrylate, and the like, but are not limited to these examples. These aziridinyl group-containing monomers may be used alone or in combination of two or more.

Styrenic monomers of the present disclosure include, for example, styrene, α-methylstyrene, p-methylstyrene, tert-methylstyrene, chlorostyrene, vinyltoluene, etc., but are not limited to these examples. do not have. These styrenic monomers may be used alone or in combination of two or more. Styrenic monomers have functional groups such as alkyl groups such as methyl groups and tert-butyl groups, nitro groups, nitrile groups, alkoxyl groups, acyl groups, sulfone groups, hydroxyl groups and halogen atoms on the benzene ring. may Among the styrene-based monomers, styrene is preferred from the viewpoint of enhancing water resistance.

Aralkyl (meth)acrylates of the present disclosure include, for example, aralkyl groups having 7 to 18 carbon atoms, such as benzyl (meth)acrylate, phenylethyl (meth)acrylate, methylbenzyl (meth)acrylate, and naphthylmethyl (meth)acrylate. and aralkyl (meth)acrylates having, but are not limited to only these examples. These aralkyl (meth)acrylates may be used alone or in combination of two or more.

Examples of addition polymerizable oxazolines of the present disclosure include 2-vinyl-2-oxazoline, 2-vinyl-4-methyl-2-oxazoline, 2-vinyl-5-methyl-2-oxazoline, 2-isopropenyl-2 -oxazoline, 2-isopropenyl-4-methyl-2-oxazoline, 2-isopropenyl-5-methyl-2-oxazoline, 2-isopropenyl-5-ethyl-2-oxazoline, etc., but only such examples is not limited to Each of these addition-polymerizable oxazolines may be used alone, or two or more of them may be used in combination. Among these addition-polymerizable oxazolines, 2-isopropenyl-2-oxazoline is preferred because of its easy availability.

Examples of polyfunctional monomers include ethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, 1,3-butanediol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, ethylene oxide-modified 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, propylene oxide-modified neopentyl glycol di(meth)acrylate, Di(meth)acrylates of polyhydric alcohols having 1 to 10 carbon atoms, such as tripropylene glycol di(meth)acrylate; Alkyl di(meth)acrylates having 2 to 50 moles of alkylene oxide groups having 2 to 4 carbon atoms, such as polypropylene glycol di(meth)acrylate having 2 to 50 and tripropylene glycol di(meth)acrylate; ethoxylation Glycerin tri(meth)acrylate, propylene oxide-modified glycerol tri(meth)acrylate, ethylene oxide-modified trimethylolpropane tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol monohydroxy tri(meth)acrylate, trimethylolpropane Tri(meth)acrylates of polyhydric alcohols having 1 to 10 carbon atoms such as triethoxytri(meth)acrylate; pentaerythritol tetra(meth)acrylate, dipentaerythritol tetra(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate Tetra (meth) acrylate of polyhydric alcohol having 1 to 10 carbon atoms such as; Penta(meth)acrylate; hexa(meth)acrylate of polyhydric alcohol having 1 to 10 carbon atoms such as pentaerythritol hexa(meth)acrylate; bisphenol A di(meth)acrylate, 2-(2'-vinyloxyethoxyethyl) Epoxy group-containing (meth)acrylates such as (meth)acrylates and epoxy (meth)acrylates; polyfunctional (meth)acrylates such as urethane (meth)acrylates; but not limited to these examples. Each of these polyfunctional monomers may be used alone, or two or more of them may be used in combination.

From the viewpoint of imparting UV stability or UV absorbability, the polymer (A) of the present disclosure contains UV-stable monomers, UV-absorbing monomers, etc. in the monomer component within a range in which the object of the present invention is not hindered. is preferred.

UV-stable monomers of the present disclosure include, for example, 4-(meth)acryloyloxy-2,2,6,6-tetramethylpiperidine, 4-(meth)acryloylamino-2,2,6,6-tetramethyl Piperidine, 4-(meth)acryloyloxy-1,2,2,6,6-pentamethylpiperidine, 4-(meth)acryloyl-1-methoxy-2,2,6,6-tetramethylpiperidine, 4-cyano -4-(meth)acryloyloxy-2,2,6,6-tetramethylpiperidine, 1-(meth)acryloyl-4-(meth)acryloylamino-2,2,6,6-tetramethylpiperidine, 4- Crotonoylamino-2,2,6,6-tetramethylpiperidine, 4-(meth)acryloylamino-1,2,2,6,6-pentamethylpiperidine, 4-cyano-4-(meth)acryloylamino- 2,2,6,6-tetramethylpiperidine, 4-crotonoyloxy-2,2,6,6-tetramethylpiperidine, 1-(meth)acryloyl-4-cyano-4-(meth)acryloylamino-2 , 2,6,6-tetramethylpiperidine, 1-crotonoyl-4-crotonoyloxy-2,2,6,6-tetramethylpiperidine, and other piperidine group-containing monomers. It is not limited only to such examples. These monomers may be used alone, respectively, or two or more of them may be used in combination. Among these UV-stable monomers, 4-(meth)acryloyloxy-2,2,6,6-tetramethylpiperidine, 4-(meth)acryloyloxy-1, 4-(meth)acryloyloxy-1, Piperidyl group-containing (meth)acrylates such as 2,2,6,6-pentamethylpiperidine and 4-cyano-4-(meth)acryloyloxy-2,2,6,6-tetramethylpiperidine are preferred.

Examples of UV-absorbing monomers of the present disclosure include benzotriazole-based UV-absorbing monomers and benzophenone-based UV-absorbing monomers, but the present invention is not limited to these examples. These monomers may be used alone, respectively, or two or more of them may be used in combination.

Benzotriazole-based UV-absorbing monomers include, for example, 2-[2′-hydroxy-5′-(meth)acryloyloxymethylphenyl]-2H-benzotriazole, 2-[2′-hydroxy-5′-(meth) ) acryloyloxyethylphenyl]-2H-benzotriazole, 2-[2′-hydroxy-5′-(meth)acryloyloxymethylphenyl]-5-tert-butyl-2H-benzotriazole, 2-[2′-hydroxy -5′-(meth)acryloylaminomethyl-5′-tert-octylphenyl]-2H-benzotriazole, 2-[2′-hydroxy-5′-(meth)acryloyloxypropylphenyl]-2H-benzotriazole, 2-[2′-hydroxy-5′-(meth)acryloyloxyhexylphenyl]-2H-benzotriazole, 2-[2′-hydroxy-3′-tert-butyl-5′-(meth)acryloyloxyethylphenyl ]-2H-benzotriazole, 2-[2′-hydroxy-3′-tert-butyl-5′-(meth)acryloyloxyethylphenyl]-5-chloro-2H-benzotriazole, 2-[2′-hydroxy -5'-tert-butyl-3'-(meth)acryloyloxyethylphenyl]-2H-benzotriazole, 2-[2'-hydroxy-5'-(meth)acryloyloxyethylphenyl]-5-chloro-2H -benzotriazole, 2-[2'-hydroxy-5'-(meth)acryloyloxyethylphenyl]-5-cyano-2H-benzotriazole, 2-[2'-hydroxy-5'-(meth)acryloyloxyethyl Phenyl]-5-tert-butyl-2H-benzotriazole, 2-[2′-hydroxy-5′-(β-(meth)acryloyloxyethoxy)-3′-tert-butylphenyl]-4-tert-butyl -2H-benzotriazole and the like, but the present invention is not limited to such examples. These monomers may be used alone, respectively, or two or more of them may be used in combination.

Benzophenone-based UV-absorbing monomers include, for example, 2-hydroxy-4-(meth)acryloyloxybenzophenone, 2-hydroxy-4-[2-hydroxy-3-(meth)acryloyloxy]propoxybenzophenone, 2-hydroxy- 4-[2-(meth)acryloyloxy]ethoxybenzophenone, 2-hydroxy-4-[3-(meth)acryloyloxy-2-hydroxypropoxy]benzophenone, 2-hydroxy-3-tert-butyl-4-[2 -(Meth)acryloyloxy]butoxybenzophenone and the like, but the present invention is not limited only to such examples. These monomers may be used alone, respectively, or two or more of them may be used in combination.

Other monomers of the present disclosure include a monomer having a cycloaliphatic hydrocarbon group, a piperidine group-containing monomer, and a nitrogen atom-containing monomer from the viewpoint of further improving adhesion to corona-treated PET, OPP, etc. Monomers and addition-polymerizable oxazolines are preferred, and among them, monomers having a cycloaliphatic hydrocarbon group, piperidine group-containing monomers and addition-polymerizable oxazolines are more preferred, and cyclohexyl (meth)acrylate and isobornyl (meth) Acrylate, (meth)acrylic acid, 2-ethylhexyl (meth)acrylate, methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, lauryl (meth)acrylate, (meth)acrylic acid Stearyl, behenyl (meth)acrylate, (meth)acrylonitrile, glycidyl (meth)acrylate, styrene, 2-isopropenyl-2-oxazoline, 4-(meth)acryloyloxy-2,2,6,6-tetramethylpiperidine , 4-(meth)acryloyloxy-1,2,2,6,6-pentamethylpiperidine, are more preferred.

The content of structural units derived from other monomers in 100 parts by mass of the polymer (A) of the present disclosure may be 60 parts by mass or more from the viewpoint of improving adhesion and scratch resistance, and may be 65 parts by mass or more. , more preferably 75 parts by mass or more, may be 99 parts by mass or less, preferably 97 parts by mass or less, more preferably 95 parts by mass or less, and even more preferably 90 parts by mass or less.

The content of structural units derived from a monomer having a cycloaliphatic hydrocarbon group in 100 parts by mass of the polymer (A) of the present disclosure is 30 parts by mass or more from the viewpoint of improving adhesion and scratch resistance. preferably 40 parts by mass or more, more preferably 50 parts by mass or more, may be 99 parts by mass or less, preferably 95 parts by mass or less, more preferably 90 parts by mass or less, and even more preferably 85 parts by mass or less.

In 100 parts by mass of the polymer (A) of the present disclosure, the content ratio of structural units derived from (meth) acrylic acid ester having a branched alkyl group is 10 parts by mass or more from the viewpoint of improving adhesion and scratch resistance. , preferably 15 parts by mass or more, more preferably 20 parts by mass or more, and may be 60 parts by mass or less, preferably 55 parts by mass or less, and more preferably 50 parts by mass or less.

In 100 parts by mass of the polymer (A) of the present disclosure, the content ratio of the structural unit derived from the piperidine group-containing monomer may be 0.1 parts by mass or more from the viewpoint of improving adhesion and scratch resistance. , preferably 0.3 parts by mass or more, more preferably 0.5 parts by mass or more, may be 10 parts by mass or less, preferably 7 parts by mass or less, more preferably 5 parts by mass or less, and further 3 parts by mass or less preferable.

In 100 parts by mass of the polymer (A) of the present disclosure, the content ratio of structural units derived from styrene-based monomers may be 40 parts by mass or less from the viewpoint of film-forming properties and flexibility, and 30 parts by mass. The following is preferable, 25 parts by mass or less is more preferable, and 20 parts by mass or less is even more preferable.

The acid value of the polymer (A) of the present disclosure may not have an acid value, but may be 50 mgKOH/g or less, preferably 40 mgKOH/g or less, and 35 mgKOH/g or less. is more preferable, and 30 mgKOH/g or less is even more preferable. When the acid value of the polymer (A) is within the above range, it is possible to obtain a water-based ink having a preferable viscosity as an inkjet ink, and effects of improving adhesion and scratch resistance can be expected.

In addition, the acid value of the polymer (A) of the present disclosure may be 1 mgKOH/g or more from the viewpoint of suppressing aggregates and suppressing viscosity change when used as an ink.

The glass transition temperature of the polymer (A) of the present disclosure may be −10° C. or higher, preferably 0° C. or higher, more preferably 5° C. or higher, even more preferably 10° C. or higher, and may be 90° C. or lower. , preferably 80° C. or lower, more preferably 70° C. or lower, and even more preferably 60° C. or lower.

The glass transition temperature (Tg) of the polymer is expressed by the formula:
1/Tg=Σ(Wm/Tgm)/100
[In the formula, Wm is the content (% by mass) of the monomer m in the monomer component for the inner layer constituting the resin layer, and Tgm is the glass transition temperature (absolute temperature: K) of the homopolymer of the monomer m]. Means the temperature determined based on the Fox equation.
In the present specification, the glass transition temperature of a polymer means the glass transition temperature determined based on the Fox formula, unless otherwise specified.

The polymer (A) of the present disclosure may be emulsion particles. The emulsion particles of the present disclosure may have a single layer or may have a multilayer structure. When the emulsion particles of the present disclosure have a multilayer structure, it preferably has 2 to 4 layers, more preferably 2 or 3 layers. In emulsion particles having a multilayer resin layer, the inner layer means the innermost layer of the emulsion particle, the outer layer means the other layers excluding the innermost layer, and the outermost layer means the layer formed on the outermost side. .
When the polymer (A) of the present disclosure is an emulsion particle, the volume average particle diameter (nm) is determined from the viewpoint of blocking resistance, adhesion to a substrate and scratch resistance, ejection stability, and improvement of image uniformity. It is preferably 100 nm or more and 500 nm or less, more preferably 100 nm or more and 400 nm or less, and most preferably 150 nm or more and 300 nm or less. The volume average particle size of the polymer (A) is not particularly limited, but can be measured by a dynamic light scattering method, a laser diffraction/scattering method, a Coulter counter, a microscope method, or the like.
The average particle size of the present disclosure is determined by the photon correlation method using a multi-sample nanoparticle size measurement system [manufactured by Otsuka Electronics Co., Ltd., trade name: nanoSAQLA], which is a particle size measurement device based on the dynamic light scattering method. is the average particle diameter (hydrodynamic diameter) obtained by cumulant analysis.

When the polymer (A) of the present disclosure is an emulsion particle having a multilayer structure, the polymer forming the inner layer may have a structural unit derived from a hydroxyl group-containing monomer, or derived from other monomers. may have a structural unit of The hydroxyl group-containing monomer and other monomers are as described above.

When the polymer (A) of the present disclosure is an emulsion particle having a multilayer structure, the content of the structural unit derived from the hydroxyl group-containing monomer is 1 part by mass or more in 100 parts by mass of the monomer component forming the inner layer. It is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, and may be 70 parts by mass or less, preferably 65 parts by mass or less, and more preferably 60 parts by mass or less.

When the polymer (A) of the present disclosure is an emulsion particle having a multilayer structure, the content of structural units derived from other monomers in 100 parts by mass of the monomer component forming the inner layer is 30 parts by mass or more. preferably 35 parts by mass or more, more preferably 40 parts by mass or more, and may be 99 parts by mass or less, preferably 95 parts by mass or less, and more preferably 90 parts by mass or less.

When the polymer (A) of the present disclosure is an emulsion particle having a multi-layered structure, among 100 parts by mass of the monomer component forming the inner layer, structural units derived from other monomers include cyclohexyl (meth)acrylate, isobornyl (Meth) acrylate, (meth) acrylic acid, 2-ethylhexyl (meth) acrylate, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, lauryl (meth) acrylate, (meth) ) stearyl acrylate, behenyl (meth)acrylate, (meth)acrylonitrile, glycidyl (meth)acrylate, styrene, 2-isopropenyl-2-oxazoline, 4-(meth)acryloyloxy-2,2,6,6- More preferred are tetramethylpiperidine and 4-(meth)acryloyloxy-1,2,2,6,6-pentamethylpiperidine.

When the polymer (A) of the present disclosure is an emulsion particle having a multilayer structure, the polymer forming the outer layer may have a structural unit derived from a hydroxyl group-containing monomer, or derived from other monomers. may have a structural unit of The hydroxyl group-containing monomer and other monomers are as described above.

When the polymer (A) of the present disclosure is an emulsion particle having a multilayer structure, the content of the structural unit derived from the hydroxyl group-containing monomer in 100 parts by mass of the monomer component forming the outer layer is 40 parts by mass or less. 35 parts by mass or less is preferable, and 30 parts by mass or less is more preferable.

When the polymer (A) of the present disclosure is an emulsion particle having a multilayer structure, the content of structural units derived from other monomers in 100 parts by mass of the monomer component forming the outer layer is 60 parts by mass or more. 65 parts by mass or more is preferable, and 70 parts by mass or more is more preferable.

When the polymer (A) of the present disclosure is an emulsion particle having a multi-layered structure, among 100 parts by mass of the monomer component forming the outer layer, structural units derived from other monomers include cyclohexyl (meth)acrylate, isobornyl (Meth) acrylate, (meth) acrylic acid, 2-ethylhexyl (meth) acrylate, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, lauryl (meth) acrylate, (meth) ) stearyl acrylate, behenyl (meth)acrylate, (meth)acrylonitrile, glycidyl (meth)acrylate, styrene, 2-isopropenyl-2-oxazoline, 4-(meth)acryloyloxy-2,2,6,6- More preferred are tetramethylpiperidine and 4-(meth)acryloyloxy-1,2,2,6,6-pentamethylpiperidine.

When the polymer (A) of the present disclosure is an emulsion particle having a multilayer structure, the polymer forming the outermost layer may have a structural unit derived from a hydroxyl group-containing monomer, and other monomers. You may have a structural unit derived from. The hydroxyl group-containing monomer and other monomers are as described above.

When the polymer (A) of the present disclosure is an emulsion particle having a multilayer structure, the content of the structural unit derived from the hydroxyl group-containing monomer is 40 parts by mass or less in 100 parts by mass of the monomer component forming the outermost layer. 35 parts by mass or less is preferable, and 30 parts by mass or less is more preferable.

When the polymer (A) of the present disclosure is an emulsion particle having a multilayer structure, the content of structural units derived from other monomers in 100 parts by mass of the monomer component forming the outermost layer is 60 parts by mass or more. 65 parts by mass or more is preferable, and 70 parts by mass or more is more preferable.

When the polymer (A) of the present disclosure is an emulsion particle having a multilayer structure, among 100 parts by mass of the monomer component forming the outermost layer, structural units derived from other monomers include cyclohexyl (meth)acrylate, Isobornyl (meth)acrylate, (meth)acrylic acid, 2-ethylhexyl (meth)acrylate, methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, lauryl (meth)acrylate, ( meth)stearyl acrylate, behenyl (meth)acrylate, (meth)acrylonitrile, glycidyl (meth)acrylate, styrene, 2-isopropenyl-2-oxazoline, 4-(meth)acryloyloxy-2,2,6,6 -tetramethylpiperidine, 4-(meth)acryloyloxy-1,2,2,6,6-pentamethylpiperidine, are more preferred.

The mass ratio of the polymer layer composing the inner layer to the polymer layer composing the outer layer of the present disclosure (mass of the polymer composing the inner layer/mass of the polymer composing the outer layer) is , From the viewpoint of improving flexibility, blocking resistance, adhesion to substrates and scratch resistance, preferably 10/90 to 90/10, more preferably 20/80 to 80/20, still more preferably 30/ 70 to 70/30, even more preferably 40/60 to 60/40.

The mass ratio of the polymer layer forming the inner layer to the polymer layer forming the outermost layer of the present disclosure (polymer layer forming the inner layer/polymer layer forming the outermost layer) is , From the viewpoint of improving flexibility, blocking resistance, adhesion to substrates and scratch resistance, preferably 10/90 to 90/10, more preferably 20/80 to 80/20, still more preferably 30/ 70 to 70/30, even more preferably 40/60 to 60/40.

The acid value of the polymer constituting the inner layer of the present disclosure may not have an acid value, but may be 50 mgKOH/g or less, preferably 40 mgKOH/g or less, and 35 mgKOH/g or less. is more preferably 30 mgKOH/g or less. When the acid value of the inner layer of the polymer (A) is within the above range, it is possible to obtain an aqueous ink having a viscosity suitable for an inkjet ink, and effects of improving adhesion, scratch resistance, and ejection stability can be expected. In addition, the acid value of the polymer constituting the inner layer of the present disclosure may be 1 mgKOH/g or more from the viewpoint of suppressing aggregates and suppressing viscosity change when used as an ink.

The acid value of the polymer constituting the outer layer of the present disclosure may not have an acid value, but may be 50 mgKOH/g or less, preferably 40 mgKOH/g or less, and 35 mgKOH/g or less. is more preferably 30 mgKOH/g or less. By having the acid value of the outer layer of the polymer (A) within the above range, it is possible to obtain a water-based ink having a preferable viscosity as an inkjet ink, and effects of improving adhesion, scratch resistance, and ejection stability can be expected. In addition, the acid value of the polymer constituting the outer layer of the present disclosure may be 1 mgKOH/g or more from the viewpoint of suppressing aggregates and suppressing viscosity change when used as ink.

The acid value of the polymer constituting the outermost layer of the present disclosure may not have an acid value, but may be 50 mgKOH/g or less, preferably 40 mgKOH/g or less, and 35 mgKOH/g or less. more preferably 30 mgKOH/g or less. By having the acid value of the outermost layer of the polymer (A) within the above range, it is possible to obtain a water-based ink having a preferable viscosity as an inkjet ink, and effects of improving adhesion, scratch resistance, and ejection stability can be expected. . In addition, the acid value of the polymer constituting the outermost layer of the present disclosure may be 1 mgKOH/g or more from the viewpoint of suppressing aggregates and suppressing viscosity change when used as ink.

The glass transition temperature of the polymer constituting the inner layer of the present disclosure is −10° C. or higher, preferably 0° C. or higher, from the viewpoint of adhesion and scratch resistance. From the viewpoint of scratch resistance, the temperature is preferably 120° C. or lower, more preferably 100° C. or lower. The glass transition temperature of the polymer forming the inner layer can be adjusted by adjusting the type and amount of the monomer forming the inner layer.

The glass transition temperature of the polymer constituting the outer layer of the present disclosure is 0° C. or higher, preferably 10° C. or higher, from the viewpoint of adhesion, scratch resistance, and film-forming properties, and the upper limit of the glass transition temperature is From the viewpoint of adhesion and scratch resistance, the temperature is preferably 100° C. or lower, more preferably 90° C. or lower. The glass transition temperature of the polymer forming the outer layer can be adjusted by adjusting the type and amount of the monomer forming the outer layer.

The glass transition temperature of the polymer constituting the outermost layer of the present disclosure is 0° C. or higher, preferably 10° C. or higher, from the viewpoint of adhesion, scratch resistance, and film-forming properties, and the upper limit of the glass transition temperature is , from the viewpoint of adhesion and scratch resistance, the temperature is preferably 100° C. or less, more preferably 90° C. or less. The glass transition temperature of the polymer forming the outermost layer can be adjusted by adjusting the type and amount of the monomer forming the outermost layer.
Unless otherwise specified, the glass transition temperature of the polymer constituting each layer means the glass transition temperature obtained based on the Fox equation, similarly to the glass transition temperature of the polymer (A).

<Method for producing polymer (A)>
The method for producing the polymer (A) of the present disclosure can be obtained by polymerizing a monomer containing a hydroxyl group-containing monomer. Examples of polymerization methods include emulsion polymerization, bulk polymerization, solution polymerization, and suspension polymerization, but the present invention is not limited to these examples. Among the methods for polymerizing the monomer component, the emulsion polymerization method is preferable because an environmentally friendly aqueous dispersion can be directly obtained when the monomer component is polymerized by an emulsion polymerization method.

As a method for emulsion polymerization of the monomer component, for example, an aqueous medium containing a water-soluble organic solvent such as a lower alcohol such as methanol and water, or an emulsifier is dissolved in a medium such as water, and the monomer is stirred under stirring. A method of dropping a component and a polymerization initiator, and a method of dropping a monomer component previously emulsified using an emulsifier and water into water or an aqueous medium, etc., but are limited only to such methods. isn't it. In addition, the amount of the medium may be appropriately set in consideration of the amount of non-volatile matter contained in the obtained emulsion. The medium may be charged into the reaction vessel in advance, or may be used as a pre-emulsion. In addition, the medium may be used, if necessary, during emulsion polymerization of the monomer components to produce an emulsion.

When emulsion polymerization of the monomer component is carried out, the emulsion polymerization may be carried out after mixing the monomer component, the emulsifier and the medium. Alternatively, the emulsion polymerization may be carried out by mixing at least one of the monomer component, emulsifier and medium with the rest of the pre-emulsion. The monomer component, emulsifier and medium may be added all at once, added in portions, or added dropwise continuously.

The monomers and the composition of the monomers used in polymerizing the polymer (A) of the present disclosure are as described above. The monomers and the composition of the monomers used when the polymer (A) of the present disclosure is an emulsion particle having a multilayer structure are as described above.

When the polymer (A) of the present disclosure is an emulsion particle having a multilayer structure, when forming an outer layer composed of the outer layer polymer component on the emulsion particles contained in the emulsion obtained above, the above An outer layer can be formed on the emulsion particles by subjecting the monomer component to emulsion polymerization in the emulsion in the same manner as described above. Further, in the case of forming an outer layer on the emulsion particles on which the outer layer (intermediate layer) is formed, the monomer component is emulsion-polymerized in the emulsion in the same manner as described above to form an additional layer on the emulsion particles. An outer layer comprising other outer layer polymer components can be formed. Thus, emulsion particles having a multilayer structure (core-shell emulsion particles) can be prepared by the multistage emulsion polymerization method.

When preparing the core-shell emulsion particles, one-stage or multiple-stage emulsion polymerization may be performed prior to the emulsion polymerization for forming the inner layer composed of the polymer component for the inner layer. and the emulsion polymerization for forming the intermediate layer, one or more stages of emulsion polymerization may be carried out. Further, between the emulsion polymerization for forming the intermediate layer and the emulsion polymerization for forming the outer layer, one or more stages of emulsion polymerization may be performed. Further, one-stage or multiple-stage emulsion polymerization may be carried out after the emulsion polymerization for forming the outer layer.

Examples of emulsifiers used during polymerization of the polymer (A) of the present disclosure include anionic emulsifiers, nonionic emulsifiers, cationic emulsifiers, amphoteric emulsifiers, polymer emulsifiers, etc. These emulsifiers may be used alone. Well, you may use two or more types together.

Examples of anionic emulsifiers include alkylsulfate salts such as ammonium dodecylsulfate and sodium dodecylsulfate; alkylsulfonate salts such as ammonium dodecylsulfonate, sodium dodecylsulfonate and sodium alkyldiphenylether disulfonate; ammonium dodecylbenzenesulfonate, sodium dodecylnaphthalenesulfonate and the like. polyoxyethylene alkylsulfonate salts; polyoxyethylene alkylsulfate salts; polyoxyethylene alkylarylsulfate salts; dialkylsulfosuccinates; arylsulfonic acid-formalin condensates; Fatty acid salt; bis(polyoxyethylene polycyclic phenyl ether) methacrylate sulfonate salt, propenyl-alkyl sulfosuccinate ester salt, (meth)acrylic acid polyoxyethylene sulfonate salt, (meth)acrylic acid polyoxyethylene phosphonate salt, allyl allyl group-containing sulfate esters such as oxymethylalkyloxypolyoxyethylene sulfonate salts or salts thereof; allyloxymethylalkoxyethylpolyoxyethylene sulfate ester salts; is not limited to only

Examples of nonionic emulsifiers include polyoxyethylene alkyl ethers, polyoxyethylene alkyl aryl ethers, condensates of polyethylene glycol and polypropylene glycol, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, fatty acid monoglycerides, ethylene oxide and aliphatic Condensation products with amines, allyloxymethylalkoxyethylhydroxypolyoxyethylenes, polyoxyalkylene alkenyl ethers, etc., but not limited to these examples.

Cationic emulsifiers include, for example, alkylammonium salts such as dodecylammonium chloride, but are not limited to these examples.

Examples of amphoteric emulsifiers include betaine ester emulsifiers, but are not limited to these examples.

Examples of polymer emulsifiers include poly(meth)acrylates such as sodium polyacrylate and ammonium polyacrylate; polyvinyl alcohol; polyvinylpyrrolidone; polyhydroxyalkyl (meth)acrylates such as polyhydroxyethyl acrylate; Copolymers containing one or more of the monomers constituting the coalescence as a copolymerization component may be mentioned, but the invention is not limited to these examples.

As the emulsifier, an emulsifier having a polymerizable group, that is, a so-called reactive emulsifier is preferable from the viewpoint of further improving water resistance and image uniformity, and a non-nonylphenyl emulsifier is preferable from the viewpoint of environmental protection.

Examples of reactive emulsifiers include propenyl-alkylsulfosuccinate ester salts, (meth)acrylic acid polyoxyethylene sulfonate salts, (meth)acrylic acid polyoxyethylene phosphonate salts [for example, manufactured by Sanyo Chemical Industries, Ltd., Product name: Eleminol RS-30, etc.], polyoxyethylene alkylpropenyl phenyl ether sulfonate salt [for example, Daiichi Kogyo Seiyaku Co., Ltd., product name: Aqualon HS-10, etc.], allyloxymethylalkyloxypolyoxyethylene Sulfonate salts [for example, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., trade name: Aqualon KH-10, etc.], sulfonate salts of allyloxymethyl nonylphenoxyethyl hydroxypolyoxyethylene [for example, manufactured by ADEKA Co., Ltd., trade name: ADEKA rear soap SE-10, etc.], allyloxymethylalkoxyethyl hydroxypolyoxyethylene sulfate ester salt [for example, manufactured by ADEKA Corporation, trade names: Adeka rear soap SR-10, SR-20, SR-30, etc.], bis (Polyoxyethylene polycyclic phenyl ether) methacrylated sulfonate salt [for example, manufactured by Nippon Nyukazai Co., Ltd., trade name: Antox MS-60, etc.], allyloxymethylalkoxyethyl hydroxypolyoxyethylene [for example, ADEKA Corporation] manufactured by Daiichi Kogyo Seiyaku Co., Ltd., trade name: Adekari Soap ER-10, ER-20, etc.], polyoxyethylene alkylpropenyl phenyl ether [for example, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., trade name: Aqualon RN-20, etc.], allyloxymethyl Examples include nonylphenoxyethyl hydroxypolyoxyethylene [eg, manufactured by ADEKA Co., Ltd., trade name: Adekari Soap NE-10, etc.], but are not limited to these examples. Among the above emulsifiers, from the viewpoint of pigment dispersibility, adhesion and scratch resistance, allyloxymethylalkoxyethyl hydroxypolyoxyethylene sulfate [for example, manufactured by ADEKA Co., Ltd., trade name: Adekari Soap SR-10, SR] -20, SR-30, etc.] is more preferable.

The amount of the emulsifier per 100 parts by mass of the monomer component constituting the polymer (A) is preferably 0.5 parts by mass or more, more preferably 1 part by mass or more, and even more preferably, from the viewpoint of improving polymerization stability. is 2 parts by mass or more, particularly preferably 3 parts by mass or more, and from the viewpoint of improving water resistance, scratch resistance, and blocking resistance, it is preferably 10 parts by mass or less, more preferably 7 parts by mass or less.

When the polymer (A) of the present disclosure is an emulsion particle having a multilayer structure, the amount of the emulsifier per 100 parts by mass of the inner layer monomer component is preferably 0.01 mass from the viewpoint of improving the polymerization stability. parts or more, more preferably 0.5 parts by mass or more, still more preferably 1 part by mass or more, and from the viewpoint of improving flexibility, blocking resistance, adhesion to substrates and scratch resistance, preferably 20 parts by mass parts or less, more preferably 15 parts by mass or less, and even more preferably 14 parts by mass or less.

When the polymer (A) of the present disclosure is an emulsion particle having a multilayer structure, the amount of the emulsifier per 100 parts by mass of the outer layer monomer component is preferably 0.01 mass from the viewpoint of improving the polymerization stability. parts or more, more preferably 0.5 parts by mass or more, still more preferably 1 part by mass or more, and from the viewpoint of improving flexibility, blocking resistance, adhesion to substrates and scratch resistance, preferably 20 parts by mass parts or less, more preferably 15 parts by mass or less, and even more preferably 14 parts by mass or less.

Examples of polymerization initiators for polymerizing the polymer (A) of the present disclosure include azobisisobutyronitrile, 2,2-azobis(2-methylbutyronitrile), 2,2-azobis(2, 4-dimethylvaleronitrile), 2,2-azobis (2-diaminopropane) hydrochloride, 4,4-azobis (4-cyanovaleric acid), 2,2-azobis (2-methylpropionamidine) and other azo compounds ; persulfates such as ammonium persulfate and potassium persulfate; hydrogen peroxide, benzoyl peroxide, parachlorobenzoyl peroxide, lauroyl peroxide, and peroxides such as ammonium peroxide; not to be These polymerization initiators may be used alone or in combination of two or more.

The amount of the polymerization initiator per 100 parts by mass of the monomer components constituting the polymer (A) is preferably 0.05 from the viewpoint of increasing the polymerization rate and reducing the residual amount of unreacted monomer components. It is not less than 0.1 part by mass, more preferably not less than 0.1 part by mass, and preferably not more than 1 part by mass, more preferably not more than 0.5 part by mass, from the viewpoint of improving water resistance.

When the polymer (A) of the present disclosure is an emulsion particle having a multi-layered structure, the amount of the polymerization initiator per 100 parts by mass of the inner layer monomer component increases the polymerization rate, and the unreacted inner layer monomer component is From the viewpoint of reducing the residual amount, it is preferably 0.01 parts by mass or more, more preferably 0.05 parts by mass or more, and still more preferably 0.1 parts by mass or more. From the viewpoint of improving adhesion and scratch resistance, the amount is preferably 1 part by mass or less, more preferably 0.8 parts by mass or less, and even more preferably 0.5 parts by mass or less.

When the polymer (A) of the present disclosure is an emulsion particle having a multilayer structure, the amount of the polymerization initiator per 100 parts by mass of the outer layer monomer component increases the polymerization rate and increases the unreacted inner layer monomer. From the viewpoint of reducing the residual amount of the components, it is preferably 0.01 parts by mass or more, more preferably 0.05 parts by mass or more, and still more preferably 0.1 parts by mass or more. From the viewpoint of improving adhesion to the material and scratch resistance, the amount is preferably 1 part by mass or less, more preferably 0.8 parts by mass or less, and even more preferably 0.5 parts by mass or less.

The method of adding the polymerization initiator is not particularly limited. Examples of the method of addition include batch charging, divided charging, and continuous dropwise addition. Moreover, from the viewpoint of advancing the completion time of the polymerization reaction, part of the polymerization initiator may be added before or after the completion of adding the monomer components to the reaction system.

In order to accelerate the decomposition of the polymerization initiator, for example, a reducing agent such as sodium bisulfite and a decomposing agent for the polymerization initiator such as a transition metal salt such as ferrous sulfate are added to the reaction system in an appropriate amount. good too.

A chain transfer agent can also be used to adjust the weight average molecular weight of the emulsion particles. Examples of chain transfer agents include 2-ethylhexyl thioglycolate, tert-dodecylmercaptan, n-octylmercaptan, n-dodecylmercaptan, mercaptoacetic acid, mercaptopropionic acid, 2-mercaptoethanol, α-methylstyrene, α-methyl Examples include styrene dimer and the like, but are not limited to these examples. These chain transfer agents may be used alone or in combination of two or more. The amount of the chain transfer agent per 100 parts by weight of the monomer component is preferably 0.01 to 10 parts by weight from the viewpoint of appropriately adjusting the weight average molecular weight of the emulsion particles.

Additives such as a pH buffer, a chelating agent, and a film-forming aid may be added to the reaction system, if necessary. The amount of the additive varies depending on its type and cannot be determined unconditionally. Generally, the amount of the additive per 100 parts by weight of the monomer component is preferably about 0.01 to 5 parts by weight, more preferably about 0.1 to 3 parts by weight.

The atmosphere in which the monomer components are emulsion-polymerized is not particularly limited, but from the viewpoint of increasing the efficiency of the polymerization initiator, an inert gas such as nitrogen gas is preferable.

The polymerization temperature for emulsion polymerization of the monomer components is not particularly limited, but is generally preferably 50 to 100°C, more preferably 60 to 95°C. The polymerization temperature may be constant or may be changed during the polymerization reaction.

The polymerization time for emulsion polymerization of the monomer components is not particularly limited, and may be appropriately set according to the progress of the polymerization reaction, but is usually about 2 to 9 hours.

In addition, when the monomer component is emulsion-polymerized, part or all of the acidic groups possessed by the obtained polymer component may be neutralized with a neutralizing agent. The neutralizing agent may be used after adding the monomer components in the final stage, for example, may be used between the first-stage polymerization reaction and the second-stage polymerization reaction, and may be used during the initial emulsification. It may be used at the end of the polymerization reaction.

Neutralizing agents include, for example, hydroxides of alkali metals and alkaline earth metals such as sodium hydroxide; carbonates of alkali metals and alkaline earth metals such as sodium hydrogen carbonate and calcium carbonate; ammonia, monomethylamine, dimethyl Examples include, but are not limited to, alkaline substances such as organic amines such as aminoethanol. Among these neutralizing agents, a volatile alkaline substance such as ammonia is preferable from the viewpoint of improving water resistance, and sodium hydrogen carbonate is preferable from the viewpoint of improving the storage stability of emulsion particles. Neutralizing agents can be used, for example, as aqueous solutions.

When the outer layer is formed on the emulsion particles obtained above, the monomer component constituting the outer layer after the polymerization reaction rate in producing the emulsion particles reaches 90% or more, preferably 95% or more. is preferably emulsion-polymerized from the viewpoint of forming a layer-separated structure in the emulsion particles.

After forming the inner layer of the emulsion particles and before forming the outer layer, if necessary, a layer composed of other polymer components may be formed within a range in which the object of the present invention is not hindered. Therefore, when producing the emulsion particles contained in the emulsion for water-based ink of the present invention, after forming the inner layer of the emulsion particles and before forming the outer layer, the required may form a layer composed of other polymer components.

The monomer component used for forming the outer layer may be the same as the monomer component used as the starting material for the inner layer of the emulsion particles. The emulsion polymerization method and polymerization conditions for forming the outer layer can be the same as the method and polymerization conditions for producing the inner layer of the emulsion particles.

Emulsion particles having an inner layer and an outer layer can be obtained as described above. If necessary, a surface layer made of other polymer components may be further formed on the surface of the outer layer as long as the object of the present invention is not hindered.

Emulsion particles having an inner layer and an outer layer can be obtained as described above. If necessary, a surface layer made of other polymer components may be further formed on the surface of the outer layer as long as the object of the present invention is not hindered.

<Crosslinking agent (B)>
The aqueous dispersion of the present disclosure contains a crosslinker (B).
The cross-linking agent (B) of the present disclosure preferably has a functional group that reacts with an acid group (especially a carboxyl group). Examples of functional groups that react with acid groups (especially carboxyl groups) include oxazoline groups, epoxy groups, carbodiimide groups, isocyanate groups, and silane groups. A carbodiimide group is more preferred, and a carbodiimide group is even more preferred from the viewpoint of storage stability and coating film strength after low-temperature drying.

The low temperature used herein may be 120° C. or lower, 110° C. or lower, or 100° C. or lower.

Specific examples of the cross-linking agent (B) of the present disclosure include oxazoline group-containing compounds, epoxy group-containing compounds, carbodiimide group-containing compounds, isocyanate group-containing compounds, and silane group-containing compounds. These cross-linking agents may be used alone or in combination of two or more. Among these cross-linking agents, oxazoline group-containing compounds and epoxy group-containing compounds are preferred from the viewpoint of improving the water resistance and storage stability of the aqueous dispersion of the present invention and the image uniformity of aqueous inks using the aqueous dispersion. , carbodiimide group-containing compounds are preferable, oxazoline group-containing compounds and carbodiimide group-containing compounds are more preferable, and carbodiimide group-containing compounds are more preferable from the viewpoint of storage stability and crosslinkability at low temperatures. The cross-linking agent (B) of the present disclosure may be used alone or in combination of two or more.

Examples of oxazoline group-containing compounds of the present disclosure include 2,2′-bis(2-oxazoline), 2,2′-methylene-bis(2-oxazoline), 2,2′-ethylene-bis(2-oxazoline ), 2,2′-trimethylene-bis(2-oxazoline), 2,2′-tetramethylene-bis(2-oxazoline), 2,2′-hexamethylene-bis(2-oxazoline), 2,2′ -octamethylene-bis(2-oxazoline), 2,2'-ethylene-bis(4,4'-dimethyl-2-oxazoline), 2,2'-p-phenylene-bis(2-oxazoline), 2, 2′-m-phenylene-bis(2-oxazoline), 2,2′-m-phenylene-bis(4,4′-dimethyl-2-oxazoline), bis(2-oxazolinylcyclohexane) sulfide, bis( 2-oxazolinylnorbornane) sulfide, oxazoline ring-containing polymers, and the like. As the oxazoline group-containing compound, for example, manufactured by Nippon Shokubai Co., Ltd., trade names: Epocross WS-500, Epocross WS-700, Epocross WS-700, Epocross K-2010, Epocross K-2020, Epocross K-2030, etc. A commercial item is mentioned.

Examples of epoxy group-containing compounds of the present disclosure include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, glycerin triglycidyl ether, glycerol polyglycidyl ether, polyglycerol polyglycidyl ether, trimethylolpropane poly Examples include polyglycidyl ethers such as glycidyl ether, sorbitol polyglycidyl ether, pentaerythritol polyglycidyl ether, resorcinol diglycidyl ether, neopentyl glycol diglycidyl ether, and hydrogenated bisphenol A diglycidyl ether.

Examples of the carbodiimide group-containing compound of the present disclosure include aromatic carbodiimide compounds, aliphatic carbodiimide compounds, and the like. Carbodiimide group-containing compounds of the present disclosure include Carbodilite SV-02, Carbodilite V-02, Carbodilite V-02-L2, Carbodilite V-04, Carbodilite V-06, Carbodilite V-10, Carbodilite SW-12G, Carbodilite E- 02 and Carbodilite E-05 (both are trade names).

Examples of isocyanate group-containing compounds of the present disclosure include aromatic polyisocyanates such as xylene diisocyanate, diphenylmethane diisocyanate, triphenylmethane triisocyanate, tolylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, and hydrogenated products of the above aromatic polyisocyanates. , dimers or trimers of these polyisocyanates, and adducts of these polyisocyanates and polyols such as trimethylolpropane. These isocyanate group-containing compounds may be used alone or in combination of two or more. As the isocyanate group-containing compound, a blocked isocyanate compound in which the active isocyanate group in the polyisocyanate compound is previously reacted with a blocking agent such as phenol to be inactivated may be used. The use of a blocked isocyanate compound can improve the storage stability of the aqueous dispersion of the present invention and the ink using it.

Silane group-containing compounds of the present disclosure include, for example, alkoxysilane compounds such as bis-(3-triethoxysilylpropyl)-tetrasulfane, bis-(3-triethoxysilylpropyl)-disulfane, ethoxysiloxane oligomers, Hydrolysates of these alkoxysilane compounds and the like are included.

The isocyanate group-containing compounds of the present disclosure include, for example, "Coronate L", "Coronate HX", "Coronate HL", "Coronate HL-S", "Coronate 2234", "Aquanate 105", "Aquanate 130", "Aquanate 140", "Aquanate 200", "Aquanate 210" [manufactured by Tosoh Corporation, "Coronate" and "Aquanate" are registered trademarks], "Desmodur N3400" [Sumitomo Bayer Urethane Co., Ltd. ) (now Bayer AG), "Desmodur" is a registered trademark), "Duranate D-201", "Duranate TSE-100", "Duranate TSS-100", "Duranate 24A-100", " Duranate E-405-80T", "Duranate WB40-100", "Duranate WB40-80D", "Duranate WT20-100", "Duranate WT30-100", "Duranate WT31-100", "Duranate WL70-100", " Duranate WR80-70P", "Duranate WE50-100", "Duranate WM44-L70G" [manufactured by Asahi Kasei Chemicals Co., Ltd., "Duranate" is a registered trademark], "Takenate D-110N", "Takenate D-120N" , "Takenate M-631N", "MTERT-Olestar NP1200" (manufactured by Mitsui Chemicals Polyurethanes, Ltd., "Takenate" and "Olestar" are registered trademarks).

A plurality of functional groups may be included in the cross-linking agent of the present disclosure. The amount of functional groups contained in the cross-linking agent of the present disclosure is preferably 100 g/mol or more, more preferably 150 g/mol or more, still more preferably 200 g/mol or more, preferably 700 g/mol or less, and 650 g/mol or less. More preferably, it is 600 g/mol or less.

Functional groups included in the cross-linking agents of the present disclosure include oxazoline groups, epoxy groups, carbodiimide groups, isocyanate groups, silane groups, and the like.

The functional group included in the cross-linking agent of the present disclosure is included in the cross-linking agent possessed by the main agent (the polymer (A), or the polymer (A) and the wax component (C) when the wax component (C) is included). It can react with a reactive group that reacts with a functional group to form a crosslinked structure.

Reactive groups that react with the functional groups of the crosslinkers of the present disclosure include acid groups, hydroxyl groups, amino groups, and the like. The acid group includes a carboxyl group, a sulfonic acid group, a phosphoric acid group and the like, and a carboxyl group is more preferable.

The 1:1 equivalent number of the functional group of the cross-linking agent of the present disclosure and the main agent (polymer (A), or when including the wax component (C), the polymer (A) and the wax component (C)) is, for example, It is calculated from the following formula.

Amount of cross-linking agent = Reactive group of main agent/(56.1 x 1000) x Equivalent weight of cross-linking agent x Amount of main agent It is preferable from the viewpoint of improving adhesion, blocking resistance, and cellophane tape peeling resistance.
The amount of functional groups contained in the cross-linking agent can be measured by a known method according to the type of functional group, catalog values may be used as a reference, the polymer solution is lyophilized, and this is subjected to 1H-NMR. , and the amount of each functional group may be calculated from the absorption peak intensity derived from each functional group and the absorption peak intensity derived from other monomers.

<Wax component (C)>
The aqueous dispersion of the present disclosure can further improve scratch resistance, water resistance, and adhesion by containing a wax component (C).

Wax components of the present disclosure can include natural waxes and synthetic waxes.

Natural waxes include petroleum waxes, vegetable waxes, animal and plant waxes, and the like. Examples of petroleum wax include paraffin wax, microcrystalline wax, petrolatum, and the like. Plant-based waxes include carnauba wax, candelilla wax, rice wax, Japan wax, and the like. Examples of animal and plant waxes include lanolin and beeswax.

Synthetic waxes include synthetic hydrocarbon waxes and modified waxes. Synthetic hydrocarbon waxes include polyolefin waxes, (meth)acrylic waxes, Fischer-Tropsch waxes, and the like. Modified waxes include paraffin wax derivatives, montan wax derivatives, microcrystalline wax derivatives and the like. Polyolefin waxes and (meth)acrylic waxes are preferred from the viewpoint of improving adhesion and scratch resistance.

The (meth)acrylic wax is not particularly limited, and for example, it may be produced using a monomer having an alkyl group of 10 or more carbon atoms (meth) ) As acrylic monomers, polymers produced from lauryl (meth)acrylate, tridecyl (meth)acrylate, cetyl (meth)acrylate, stearyl (meth)acrylate, behenyl (meth)acrylate, or derivatives thereof, etc. mentioned.

A commercially available product can also be used as the (meth)acrylic wax. Preferred commercial products include ST100 and ST200 manufactured by Nippon Shokubai Co., Ltd.

The polyolefin wax is not particularly limited, and examples thereof include waxes produced from olefins such as ethylene, propylene and butylene or derivatives thereof, and copolymers thereof, specifically polyethylene waxes, polypropylene waxes and polybutylene. wax, a copolymer wax composed of ethylene and a monomer having a carboxylic acid group such as methacrylic acid or acrylic acid, and an oxidized polyethylene wax. Among these, polyethylene waxes, polypropylene waxes, copolymer waxes composed of ethylene and a monomer having a carboxylic acid group such as methacrylic acid or acrylic acid, and oxidized polyethylene waxes are preferred from the viewpoint of improving adhesion and scratch resistance. .

The oxidized polyethylene wax of the present disclosure is obtained by oxidizing polyethylene wax and has a skeleton derived from polyethylene (polyethylene skeleton). The polyethylene skeleton mainly has structural units derived from ethylene. The polyethylene skeleton may be a homopolyethylene (ethylene homopolymer) skeleton, a block polyethylene (a block copolymer of ethylene and another olefin) skeleton, or a random polyethylene (ethylene and another olefin random copolymer) skeleton. Other olefins include alkenes such as propylene, isobutylene, 1-butene, 1-pentene and 1-hexene. These components may be linear or branched. Other olefin components have, for example, 2 to 6 carbon atoms.

The content of the ethylene component in the polyethylene skeleton (content of structural units derived from ethylene) is, for example, 60 mol% or more, and may be 70 mol% or more. When the polyethylene skeleton is a block polyethylene skeleton or a random polyethylene skeleton, the content of the ethylene component in the polyethylene skeleton (the content of structural units derived from ethylene) is, for example, 95 mol% or less, and 90 mol% or less. good too.

The oxidized polyethylene wax preferably contains a high-density oxidized polyethylene wax from the viewpoint of obtaining better adhesion and scratch resistance.

A commercially available product can also be used as the oxidized polyethylene wax. Preferred commercially available products include BYK AQUACER497, AQUACER515, AQUACER531, AQUACER1547, and the like.

The wax component (C) can be used singly or in combination of two or more.

The wax component (C) of the present disclosure is preferably in the form of solid wax particles dissolved or dispersed in a solvent, more preferably in the form of an emulsion dispersed in the solvent. The solvent is preferably an aqueous medium, more preferably the same aqueous medium as the aqueous medium used for the solvent of the aqueous ink composition.

The volume average particle diameter (nm) of the wax particles of the present disclosure is preferably 25 nm or more and 500 nm or less, more preferably 30 nm or more and 400 nm or less. The volume average particle size of wax particles is
Although not particularly limited, it can be measured by a dynamic light scattering method, a laser diffraction/scattering method, a Coulter counter, a microscope method, or the like.

The average particle size described in this example was determined by the photon correlation method using a multi-sample nanoparticle size measurement system [manufactured by Otsuka Electronics Co., Ltd., trade name: nanoSAQLA], which is a particle size measurement device based on the dynamic light scattering method. This is the average particle diameter (hydrodynamic diameter) obtained by calculating the correlation function and performing cumulant analysis.

From the viewpoint of adhesion, the melting point of the wax component (C) of the present disclosure is preferably 20° C. or higher, more preferably 25° C. or higher, even more preferably 30° C. or higher, preferably 150° C. or lower, and more preferably 140° C. or lower. , 130° C. or less is more preferable. The melting point (Tm ₂ ) of the wax component (B) can be measured with a melting point measuring device conforming to JIS K 0064.

The acid value (mgKOH/g) of the wax component of the present disclosure may or may not match from the viewpoint of adhesion, preferably 0 mgKOH/g, preferably 100 mgKOH/g or less, more preferably 90 mgKOH/g or less, 80 mgKOH/g or less is more preferable.

<Aqueous dispersion>
The content of the polymer (A) in 100 parts by mass of the nonvolatile content of the aqueous dispersion of the present disclosure may be 60 parts by mass or more from the viewpoint of adhesion, scratch resistance, and blocking resistance. It is preferably 70 parts by mass or more, and may be 99 parts by mass or less, preferably 98 parts by mass or less, and more preferably 95 parts by mass or less.

The non-volatile content of the aqueous dispersion of the present disclosure may be calculated as a mass excluding the mass of volatile components contained in the resin and various additives from the total mass of the aqueous dispersion. Dry in a dryer at a temperature of 110 ° C. for 1 hour, and use the resulting residue as a non-volatile matter, formula:
[Non-volatile content (mass%) in aqueous resin dispersion]
= ([mass of residue] ÷ [water-based resin dispersion 1 g]) × 100
can be determined based on

The content of the crosslinking agent (B) in 100 parts by mass of the nonvolatile content of the aqueous dispersion of the present disclosure may be 1 part by mass or more from the viewpoint of adhesion, scratch resistance, and blocking resistance, and 2 parts by mass or more It is preferably 5 parts by mass or more, and may be 40 parts by mass or less, preferably 35 parts by mass or less, and more preferably 30 parts by mass or less.

The total content of the polymer (A) and the cross-linking agent (B) in 100 parts by mass of the nonvolatile content of the aqueous dispersion of the present disclosure is 70 parts by mass or more from the viewpoint of adhesion, scratch resistance, water resistance, and blocking resistance. preferably 75 parts by mass or more, more preferably 80 parts by mass or more, and may be 99 parts by mass or less, preferably 97 parts by mass or less, and more preferably 95 parts by mass or less.

The mass ratio of the polymer (A) and the cross-linking agent (B) of the present disclosure may be 99/1 to 60/40 from the viewpoint of adhesion, scratch resistance, water resistance, and blocking resistance, and 99/ 1 to 65/35 is preferred, and 95/5 to 70/30 is more preferred.

When the polymer (A) of the present disclosure has a structural unit derived from an acid group-containing monomer, the mass ratio of the structural unit derived from the acid group-containing monomer and the cross-linking agent (B) is From the viewpoint of scratch resistance, water resistance and blocking resistance, it may be 30/70 to 1/99, preferably 20/80 to 2/98.

The content of the polymer (A) in the total 100 parts by mass of the polymer (A) and the cross-linking agent (B) in the non-volatile content of the aqueous dispersion of the present disclosure is preferably 60 parts by mass or more, and more preferably 65 parts by mass or more. It is preferably 70 parts by mass or more, more preferably 99 parts by mass or less, more preferably 97 parts by mass or less, and even more preferably 95 parts by mass or less.

The content of the cross-linking agent (B) in the total 100 parts by mass of the polymer (A) and the cross-linking agent (B) in the non-volatile content of the aqueous dispersion of the present disclosure is preferably 1 part by mass or more, and more preferably 3 parts by mass or more. It is preferably 5 parts by mass or more, more preferably 40 parts by mass or less, more preferably 35 parts by mass or less, and even more preferably 30 parts by mass or less.

When the aqueous dispersion of the present disclosure contains a wax component, the total content of the polymer (A) and the wax component (C) in 100 parts by mass of the non-volatile matter of the aqueous dispersion is adhesion, scratch resistance, water resistance, From the viewpoint of blocking resistance, it may be 60 parts by mass or more, preferably 65 parts by mass or more, more preferably 70 parts by mass or more, and may be 99 parts by mass or less, preferably 97 parts by mass or less, and 95 parts by mass or less. is more preferred.

When the aqueous dispersion of the present disclosure contains a wax component, the content of the wax component (C) in 100 parts by mass of the nonvolatile matter of the aqueous dispersion is 1 from the viewpoint of adhesion, scratch resistance, water resistance, and blocking resistance. It may be at least 3 parts by mass, preferably at least 3 parts by mass, more preferably at least 5 parts by mass, and may be at most 30 parts by mass, preferably at most 25 parts by mass, and more preferably at most 20 parts by mass.

When the aqueous dispersion of the present disclosure contains a wax component, the mass ratio (A) + (B) / (C) of the sum of the polymer (A) and the cross-linking agent (B) to the wax component (C) is the adhesion , from the viewpoint of scratch resistance, water resistance and blocking resistance, it may be 99/1 to 70/20, preferably 99/1 to 75/25, more preferably 95/5 to 80/20.

The content of the polymer (A) in 100 parts by mass of the aqueous dispersion of the present disclosure may be 20 parts by mass or more from the viewpoint of adhesion, scratch resistance, water resistance, and blocking resistance. It is preferably 35 parts by mass or more, and may be 70 parts by mass or less, preferably 60 parts by mass or less, and more preferably 50 parts by mass or less.

When the aqueous dispersion of the present disclosure contains a wax component, the content of the wax component (C) in 100 parts by mass of the aqueous dispersion is 0.1 mass from the viewpoint of adhesion, scratch resistance, water resistance, and blocking resistance. It may be 0.5 parts by mass or more, preferably 1 part by mass or more, and may be 20 parts by mass or less, preferably 15 parts by mass or less, and more preferably 10 parts by mass or less.

When the aqueous dispersion of the present disclosure contains a wax component, a total of 100 parts by mass of the polymer (A), the cross-linking agent (B) and the wax component (C) in the nonvolatile matter of the aqueous dispersion, The content is preferably 70 parts by mass or more, more preferably 75 parts by mass or more, still more preferably 80 parts by mass or more, preferably 99 parts by mass or less, more preferably 97 parts by mass or less, and even more preferably 95 parts by mass or less.

When the aqueous dispersion of the present disclosure contains a wax component, the wax component (B) is The content is preferably 1 part by mass or more, more preferably 3 parts by mass or more, still more preferably 5 parts by mass or more, preferably 30 parts by mass or less, more preferably 25 parts by mass or less, and even more preferably 20 parts by mass or less.

The aqueous dispersion of the present disclosure includes a polymer (A) or a cross-linking agent (B), a resin emulsion other than the wax component (C), a water-soluble resin, a water-dispersible resin, etc., as long as the object of the present invention is not hindered. of resin may be contained.
In addition, the aqueous dispersion of the present disclosure contains, for example, surfactants, film-forming aids, UV absorbers, UV inhibitors, fillers, leveling agents, dispersants, Additives such as thickeners, wetting agents, plasticizers, stabilizers, antioxidants, preservatives and the like may be included in appropriate amounts.

The amount of coarse particles of 1 μm or more in the aqueous dispersion of the present disclosure is preferably less than 300× ¹⁰ μm ³ /ml from the viewpoint of film-forming properties and ejection stability of ink using the aqueous dispersion, and 100 More preferably, it is ×10 ⁶ μm ³ /ml.

<Aqueous ink>
The aqueous dispersion of the present disclosure can be suitably used for aqueous ink.

The content of the polymer (A) in 100 parts by mass of the water-based ink of the present disclosure may be 1 part by mass or more from the viewpoint of ejection stability, storage stability, and dispersion stability when used for white ink, and may be 3 parts by mass. It is preferably at least 5 parts by mass, more preferably at least 5 parts by mass, may be at most 50 parts by mass, preferably at most 40 parts by mass, more preferably at most 30 parts by mass, and even more preferably at most 20 parts by mass. On the other hand, when used for color inks other than white ink, from the viewpoint of ejection stability and storage stability, the amount may be 1 part by mass or more, preferably 3 parts by mass or more, more preferably 5 parts by mass or more, and 40 parts by mass. 30 parts by mass or less is preferable, 25 parts by mass or less is more preferable, and 20 parts by mass or less is even more preferable.

When the aqueous dispersion of the present disclosure contains a wax component, the content of the wax component (C) in 100 parts by mass of the aqueous ink using the aqueous dispersion is 0.01 mass from the viewpoint of ejection stability and storage stability. It may be 0.05 parts by mass or more, preferably 0.1 parts by mass or more, and may be 8 parts by mass or less, preferably 6 parts by mass or less, and more preferably 4 parts by mass or less.

In the water-based ink of the present disclosure, the mass ratio (A)+(B)/(C) of the sum of the polymer (A) and the cross-linking agent (B) to the wax component (C) is the adhesion, scratch resistance, and water resistance. From the viewpoint of properties and blocking resistance, it may be 99/1 to 70/20, preferably 99/1 to 75/25, more preferably 95/5 to 80/20.

The content of the cross-linking agent (B) in 100 parts by mass of the aqueous ink of the present disclosure is 0.01 part by mass or more from the viewpoint of ejection stability, storage stability, image uniformity, and prevention of sedimentation of the white pigment in the white ink. preferably 0.05 parts by mass or more, more preferably 0.1 parts by mass or more, and may be 10 parts by mass or less, preferably 8 parts by mass or less, and more preferably 6 parts by mass or less.

In the water-based ink of the present disclosure, the mass ratio of the polymer (A) and the cross-linking agent (B) is 99/1 to 60/40 from the viewpoint of adhesion, scratch resistance, blocking resistance, and image uniformity. preferably 99/1 to 65/35, more preferably 95/5 to 70/30.

Aqueous inks of the present disclosure contain a colorant. Colorant hues include, for example, achromatic colors such as white, black, and gray, and chromatic colors such as yellow, magenta, cyan, blue, red, orange, and green. is not limited to only

Colorants of the present disclosure include pigments and dyes. Among these, pigments are preferred because of their excellent weather resistance. When a pigment is used, the pigment may be used in the form of a pigment dispersion such as a paste. Examples of pigments include organic pigments and inorganic pigments, and these may be used alone or in combination.

Examples of dyes include C.I. I. solvent black, C.I. I. Solvent Red, C.I. I. Solvent Yellow, C.I. I. solvent blue, C.I. I. solvent green, C.I. I. solvent orange, C.I. I. Examples include solvent violet and the like, but the present invention is not limited only to such examples.

Examples of organic pigments include azo pigments such as benzidine and Hansa yellow; azomethine pigments; methine pigments; anthraquinone pigments; phthalocyanine pigments such as phthalocyanine blue; perinone pigments; pigments, iminoisoindolinone pigments, quinacridone pigments such as quinacridone red and quinacridone violet, flavanthrone pigments, indanthrone pigments, anthrapyrimidine pigments, carbazole pigments, monoarylide yellow, diarylide yellow, benzimidazolone yellow, tolyl orange , naphthol orange, and quinophthalone pigments, but the present invention is not limited to these examples. These organic pigments may be used alone or in combination of two or more. Preferred organic pigments include, for example, C.I. I. Pigment Yellow, C.I. I. Pigment Red, C.I. I. pigment orange, C.I. I. pigment violet, C.I. I. pigment blue, C.I. I. pigment green and the like.

Examples of inorganic pigments include titanium dioxide, antimony trioxide, zinc white, lithopone, lead white, red iron oxide, black iron oxide, iron oxide, chromium oxide green, carbon black, yellow lead, molybdenum red, ferrocyanide Ferrous (Prussian blue), ultramarine, lead chromate, etc., mica, clay, aluminum powder, talc, flat-shaped pigments such as aluminum silicate, calcium carbonate, magnesium hydroxide, aluminum hydroxide , barium sulfate, and magnesium carbonate, but the present invention is not limited to these examples. These inorganic pigments may be used alone or in combination of two or more.

The colorant used in the water-based ink of the present disclosure is preferably any one colorant selected from white pigments, yellow, magenta, cyan, black, red, blue and green.

A known inorganic white pigment can be used without any particular limitation as the white pigment. Examples include silicas such as alkaline earth metal sulfates, carbonates, finely divided silicic acid and synthetic silicates, calcium silicate, alumina, alumina hydrate, titanium oxide, zinc oxide, talc and clay. . Moreover, the inorganic white pigment may be surface-treated by various surface treatment methods. Among them, surface-treated titanium oxide is preferable because it exhibits relatively good dispersibility in an aqueous medium. For example, in order to avoid photocatalytic effects, titanium oxide surface-treated with an inorganic substance is preferred, and titanium oxide surface-treated with silica and alumina is preferred. Furthermore, it is also possible to use titanium oxide which has been surface-treated with the silica and alumina and then further surface-treated with a silane coupling agent. In titanium oxide surface-treated with silica and alumina, known rutile-type or anatase-type titanium dioxide can be used as titanium oxide, and rutile-type titanium dioxide is more preferable.
Rutile-type titanium dioxide includes, for example, Typaque R-820, Typaque R-830, Typaque R-930, Typaque R-550, Typaque R-630, Typaque R-680, Typaque R-670, Typaque R-680, Typaque R-670, Typaque R-780, Typaque R-850, Typaque CR-50, Typaque CR-57, Typaque CR-Super70, Typaque CR-80, Typaque CR-90, Typaque CR-93, Typaque CR-95, Typaque CR-97, Typaque CR-60, Typaque CR-63, Typaque CR-67, Typaque CR-58, Typaque CR-85, Typaque UT771 (manufactured by Ishihara Sangyo Co., Ltd.), Typaque R-100, Typaque R-101, Typaque R-102, Tai pure R-103, Tai pure R-104, Tai pure R-105, Tai pure R-108, Tai pure R-900, Tai pure R-902, Tai pure R-960, Tai pure R-706, Tai pure R-931 (DuPont Co., Ltd.), R-25, R-21, R-32, R-7E, R-5N, R-61N, R-62N, R-42, R-45M, R-44, R-49S, GTR -100, GTR-300, D-918, TCR-29, TCR-52, FTR-700 (manufactured by Sakai Chemical Industry Co., Ltd.), JR-403, JR-605, JR-806, JR-701, JR-805 , JR-701, JR-800, JR-405, MT600B, MT150W (manufactured by Tayca) and the like.

The average particle size of the titanium oxide is preferably 100-500 nm, more preferably 150-400 nm. When the average particle size is 100 nm or less, non-settling property and dispersion stability in an aqueous medium are more likely to be achieved, but the whiteness and opacity are inferior, and there is a possibility that the practicality as an original white ink is reduced. On the other hand, if the average particle diameter is 500 nm or more, there is no problem in terms of whiteness and hiding power, but ejection stability tends to be insufficient. Practically, the particle size is more preferably 200 to 300 nm. The average particle size of titanium oxide used as a raw material is obtained by measuring the particle size of 20 particles using an electron micrograph and taking the average.

In the present invention, the polymer (A), the cross-linking agent (B) and the wax component (C), the aqueous dispersion containing (A) and (B) and (C), (A) and (B) and ( The average particle size of the aqueous ink using the aqueous dispersion containing C) is not particularly limited, but can be measured by a dynamic light scattering method, a laser diffraction/scattering method, a Coulter counter, a microscope method, or the like.

The average particle size described in this example was determined by the photon correlation method using a multi-sample nanoparticle size measurement system [manufactured by Otsuka Electronics Co., Ltd., trade name: nanoSAQLA], which is a particle size measurement device based on the dynamic light scattering method. This is the average particle diameter (hydrodynamic diameter) obtained by calculating the correlation function and performing cumulant analysis.

Organic pigments for yellow include C.I. I. Pigment Yellow 1 (Hansa Yellow G), 2, 3 (Hansa Yellow 10G), 4, 5 (Hansa Yellow 5G), 6, 7, 10, 11, 12 (Disazo Yellow AAA), 13, 14, 16, 17, 24 (flavanthrone yellow), 55 (disazo yellow AAPT), 61, 61:1, 65, 73, 74 (fast yellow 5GX), 75, 81, 83 (disazo yellow HR), 93 (condensed azo yellow 3G), 94 (condensed azo yellow 6G), 95 (condensed azo yellow GR), 97 (fast yellow FGL), 98, 99 (anthraquinone), 100, 108 (anthrapyrimidine yellow), 109 (isoindolinone yellow 2GLT), 110 ( isoindolinone yellow 3RLT), 113, 117, 120 (benzimidazolone yellow H2G), 123 (anthraquinone yellow), 124, 128 (condensed azo yellow 8G), 129, 133, 138 (quinophthalone yellow), 139 (isoind Linon Yellow), 147, 151 (Benzimidazolone Yellow H4G), 153 (Nickel Nitroso Yellow), 154 (Benzimidazolone Yellow H3G), 155, 156 (Benzimidazolone Yellow HLR), 167, 168, 172, 173 ( isoindolinone yellow 6GL), 180 (benzimidazolone yellow), and the like.

Organic pigments for magenta water-based ink include C.I. I. Pigment Red 1 (Para Red), 2, 3 (Toluidine Red), 4, 5 (lTR Red), 6, 7, 8, 9, 10, 11, 12, 14, 15, 16, 17, 18, 19, 21 , 22, 23, 30, 31, 32, 37, 38 (pyrazolone red B), 40, 41, 42, 88 (thioindigo Bordeaux), 112 (naphthol red FGR), 114 (brilliant carmine BS), 122 (dimethyl quinacridone), 123 (perylene vermillion), 144, 146, 149 (perylene scarred), 150, 166, 168 (anthanthrone orange), 170 (naphthol red F3RK), 171 (benzimidazolone maroon HFM), 175 ( benzimidazolone red HFT), 176 (benzimidazolone carmine HF3C), 177, 178 (perylene red), 179 (perylene maroon), 185 (benzimidazolone carmine HF4C), 187, 188, 189 (perylene red), 190 (perylene red), 194 (perinone red), 202 (quinacridone magenta), 209 (dichloroquinacridone red), 214 (condensed azo red), 216, 219, 220 (condensed azo), 224 (perylene red), 242 (condensed azo scarlet) ), 245 (naphthol red), or C.I. I. Pigment Violet 19 (quinacridone), 23 (dioxazine violet), 31, 32, 33, 36, 38, 43, 50 and the like.

Organic pigments for cyan include C.I. I. Pigment Blue 15, 15:1, 15:2, 15:3, 15:4, 15:6 (all of these are phthalocyanine blue), 16 (metal-free phthalocyanine blue), 17:1, 18 (alkali blue toner), 19, 21, 22, 25, 56, 60 (thren blue), 64 (dichloroindanthrone blue), 65 (violanthrone), 66 (indigo) and the like.

As the organic pigment for black, a black organic pigment such as aniline black (C.I. Pigment Black 1) can be used.

Organic pigments used in color water-based inks other than white pigments, yellow, cyan, or magenta water-based inks include C.I. I. Pigment Orange 1, 2, 5, 7, 13, 14, 15, 16 (Vulcan Orange), 24, 31 (Condensed Azo Orange 4R), 34, 36 (Benzimidazolone Orange HL), 38, 40 (Pyrantrone Orange ), 42 (isoindolinone orange RLT), 43, 51, 60 (benzimidazolone-based insoluble monoazo pigment), 62 (benzimidazolone-based insoluble monoazo pigment), 63; I. Pigment Green 7 (phthalocyanine green), 10 (green gold), 36 (chlorobrominated phthalocyanine green), 37, 47 (violanthrone green); or C.I. I. Pigment Brown 1, 2, 3, 5, 23 (Condensed Azo Brown 5R), 25 (Benzimidazolone Brown HFR), 26 (Perylene Bordeaux), 32 (Benzimidazolone Brown HFL) and the like.

The amount of the colorant per 100 parts by mass of the non-volatile content of the resin emulsion for aqueous ink used in the aqueous ink of the present disclosure is preferably 30 parts by mass or more from the viewpoint of sufficiently coloring the print or image formed with the aqueous ink. , more preferably 50 parts by mass or more, and from the viewpoint of forming a uniform coating film, it is preferably 300 parts by mass or less, more preferably 200 parts by mass or less.

When a white pigment is used, the amount of the white pigment per 100 parts by mass of the non-volatile matter of the resin emulsion for water-based ink is preferably 50 mass from the viewpoint of sufficiently coloring the print or image formed with the water-based ink and improving the color development. parts or more, more preferably 60 parts by mass or more, and preferably 300 parts by mass or less, more preferably 200 parts by mass or less from the viewpoint of forming a uniform coating film and/or improving gloss.

The water-based ink of the present disclosure contains water and other water-soluble organic solvents from the viewpoints of the ink viscosity of the water-based ink, the control of the wetting and spreading on the recording medium to be printed, the improvement of the image quality, and the ejection stability. may be included. Examples of water-soluble organic solvents include glycols such as propylene glycol, 1,3-propanediol, glycerin, dipropylene glycol, tripropylene glycol, diethylene glycol, triethylene glycol, and tetraethylene glycol; monoethylene glycol monomethyl ether, monoethylene glycol; Ethers of monoethylene glycol such as monoethyl ether, monoethylene glycol monopropyl ether, monoethylene glycol monoisopropyl ether, monoethylene glycol monobutyl ether, monoethylene glycol monoisobutyl ether; monopropylene glycol monomethyl ether, monopropylene glycol monoethyl ether , Monopropylene Glycol Monopropyl Ether, Monopropylene Glycol Monoisopropyl Ether, Monopropylene Glycol Monobutyl Ether, Monopropylene Glycol Monoisobutyl Ether, etc.; to 4), monomethyl ether of polyethylene glycol (number of EO addition moles = 2 to 10, preferably 2 to 4), monoethyl ether of polyethylene glycol (number of EO addition moles = 2 to 10, preferably 2 to 4) Propyl ether, monoisopropyl ether of polyethylene glycol (number of EO addition moles = 2 to 10, preferably 2 to 4), monobutyl ether of polyethylene glycol (number of EO addition moles = 2 to 10, preferably 2 to 4), polyethylene glycol Ether of polyethylene glycol such as monoisobutyl ether (number of EO addition moles = 2 to 10, preferably 2 to 4); Monomethyl ether of polypropylene glycol (number of EO addition moles = 2 to 10, preferably 2 to 4), polypropylene Monoethyl ether of glycol (number of EO addition moles = 2 to 10, preferably 2 to 4), monopropyl ether of polypropylene glycol (number of EO addition moles = 2 to 10, preferably 2 to 4), polypropylene glycol (EO addition Monoisopropyl ether with mole number = 2 to 10, preferably 2 to 4), monobutyl ether of polypropylene glycol (EO addition mole number = 2 to 10, preferably 2 to 4), polypropylene glycol (EO addition mole number = 2 to 10, preferably ethers of polypropylene glycol such as monoisobutyl ethers of 2 to 4). Among these, propylene glycol, diethylene glycol, triethylene glycol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monoisopropyl ether, diethylene glycol monobutyl ether, diethylene glycol monoisobutyl ether, tripropylene glycol monomethyl ether, monoethylene glycol monoisopropyl ether, mono Propylene glycol monopropyl ether is preferred. These organic solvents may be used alone or in combination of two or more.

Since the amount of the water-soluble organic solvent varies depending on the type and amount of the colorant contained in the water-based ink, it cannot be determined unconditionally. It is preferable to determine it as appropriate.

For example, if the colorant contains a white pigment, the amount of the organic solvent in 100 mass of the water-based ink may be 5 parts by mass or more from the viewpoint of controlling the wetting and spreading on the recording medium to be printed and improving the image quality. , preferably 8 parts by mass or more, more preferably 10 parts by mass or more, may be 50 parts by mass or less, preferably 45 parts by mass or less, and more preferably 40 parts by mass or less.

The water-based ink of the present disclosure contains the resin emulsion for water-based ink and a colorant. A resin such as a water-dispersible resin may also be included. Further, the water-based ink of the present invention may contain, for example, surfactants, film-forming aids, UV absorbers, UV inhibitors, fillers, leveling agents, dispersants, and thickening agents, as long as the object of the present invention is not hindered. Additives such as thickeners, wetting agents, plasticizers, stabilizers and antioxidants may be included in appropriate amounts.

As the dispersant used in the water-based ink of the present disclosure, an ionic dispersant is preferred, and a polymer dispersant is preferred. The content of the dispersant is preferably 0.1% by mass or more and 2.0% by mass or less, preferably 0.2% by mass, based on 100 parts by mass of the inkjet ink of the present invention from the viewpoint of dispersion stability and blocking resistance. More preferably, it is 1.0% by mass or less.

The dispersant used in the water-based ink of the present disclosure may have an acid value, preferably 150 mgKOH/g or less, more preferably 100 mgKOH/g, from the viewpoint of lowering the viscosity of the water-based ink, stabilizing the dispersion, and suppressing an increase in electrical conductivity. The following is more preferable, and 50 mgKOH/g or less is more preferable. The lower limit is not particularly limited, but it may be 5 mgKOH/g or more, preferably 6 mgKOH/g or more, and further preferably 7 mgKOH/g or more.
For example, as the above distributed agent, for example, DISPERBYK -102, DISPERBYK -111, DISPERBYK -190, DISPERBYK -190, DISPERBYK -194N, DISPERBYK -2010, DISPERBYK -2010, DISPERBYK -2010 BYK -2012, DISPERBYK -2015, Ebonic Japan TEGO Dispers-715W, TEGO Dispers-750W, TEGO Dispers-755W, Efka6230 manufactured by BASF, etc., Disperbyk-190, Disperbyk-191, Disperbyk-194N, Disperbyk-2010, Disperb yk-2015, TEGO Dispers-750W is more preferred.

The water-based ink of the present disclosure obtained as described above has excellent adhesion, scratch resistance, and water resistance. It can be suitably used as inks such as printing inks, gravure printing inks, and screen printing inks, especially water-based inkjet inks.

The water-based ink of the present disclosure can form prints or images having a predetermined pattern by ejecting the water-based ink onto a recording medium in a predetermined pattern using an inkjet recording apparatus, for example.

Examples of recording media include paper, paper laminated with resin films such as polyethylene, polypropylene, and polystyrene (coated paper, etc.), metal plates such as aluminum, zinc, and copper, cellulose, polyethylene terephthalate, polystyrene, and olefin-based media. Examples include resin films such as resins, polycarbonate, polyvinyl acetal, polyvinyl chloride, polyamide, nylon, and acrylic resins, paper having a metal coating, and resin films having a metal coating. As a recording medium on which the water-based ink of the present disclosure is printed, resin films are preferable, and polyethylene terephthalate and olefin-based resins are particularly preferable.

Examples of olefinic resins include polyethylene and polypropylene, and application to polypropylene such as biaxially oriented polypropylene film (OPP) and non-oriented polypropylene film (CPP) is particularly preferred.

The water-based ink of the present disclosure is preferably formed on a resin film, and its embodiment is a laminate having a printed layer formed from the water-based ink on the resin film.

The laminate of the present disclosure may or may not have a primer layer between the resin film and the printed layer, but it is preferable not to have it from the viewpoint of productivity, and printing is performed directly on the resin film. Layer formation is preferred. The laminate of the present disclosure is laminated in the order of a resin film and a printed layer, and may or may not have a protective film (laminate layer) on the printed layer, but does not have it from the viewpoint of productivity. By using the water-based ink of the present disclosure, it is possible to obtain a laminate having excellent adhesion to a substrate and excellent scratch resistance even without a primer layer or a protective film (laminate layer). can be expected.

The laminate of the present disclosure can be suitably used for various printed matter.

EXAMPLES Next, the present invention will be described in more detail based on examples, but the present invention is not limited only to these examples. In the following examples, "parts" means "parts by mass" and "%" means "% by mass" unless otherwise specified.

<Glass transition temperature of polymer component>
The glass transition temperature (Tg) of the polymer component is expressed by the formula:
1/Tg=Σ(Wm/Tgm)/100
[Wherein, Wm is the content (% by mass) of the monomer m in the monomer component constituting the polymer component, and Tgm is the glass transition temperature (absolute temperature: K) of the homopolymer of the monomer m. ]
It was obtained by calculation based on the Fox equation represented by:
<Acid value derived from carboxyl group of resin emulsion particles>
The acid value derived from the carboxyl groups of the resin emulsion particles was obtained by approximating the number of mg of potassium hydroxide required to neutralize the carboxyl groups present in 1 g of the monomer component used as an acid value.
<Minimum film-forming temperature>
The minimum film-forming temperature is a value measured according to JISK6828-2:2003.

<Average particle size>
Measurement temperature 25 ± 0.5 ° C., using a multi-sample nanoparticle size measurement system [manufactured by Otsuka Electronics Co., Ltd., product name: nanoSAQLA], which is a particle size measurement device by the dynamic light scattering method, autocorrelation by the photon correlation method A function was determined, and an average particle diameter (hydrodynamic diameter) determined by cumulant analysis was determined.
<Non-volatile content (NV)>
The non-volatile content of the aqueous dispersion of the present disclosure was obtained by weighing 1 g of the aqueous dispersion from the total mass of the aqueous dispersion, drying it with a hot air dryer at a temperature of 110° C. for 1 hour, and using the resulting residue as the non-volatile content.
formula:
[Non-volatile content (mass%) in aqueous resin dispersion]
= ([mass of residue] ÷ [water-based resin dispersion 1 g]) × 100
<Evaluation of amount of coarse particles in aqueous dispersion>
The amount of coarse particles of 1 μm or more in the aqueous dispersion of the present disclosure was measured using Multisizer 4e manufactured by Beckman Coulter, Inc. and evaluated as follows.
A: Less than 100×10 ⁶ μm ³ /ml B: Less than 100×10 ⁶ μm ³ /ml to 300×10 ⁶ μm ³ /ml C: 300×10 ⁶ μm ³ /ml or more

The abbreviations used in the examples mean the following.
SR-10: manufactured by ADEKA, emulsifier IBOA: isobornyl acrylate CHMA: cyclohexyl methacrylate St: styrene 2EHA: 2-ethylhexyl acrylate AA: acrylic acid HEMA: hydroxyethyl methacrylate LA-87: 4-methacryloyloxy-2,2,6 ,6-tetramethylpiperidine LA-82: 4-methacryloyloxy-1,2,2,6,6-pentamethylpiperidine KBM-503: 3-methacryloxypropyltrimethoxysilane Disperbyk-190: manufactured by BYK Chemie Japan, Dispersant (acid value 10 mgKOH/g)
PG: Propylene glycol manufactured by ADEKA Corporation JR-403: Titanium oxide (rutile type) manufactured by Tayca Corporation
ST-200: Nippon Shokubai Co., Ltd., (meth)acrylic WAX emulsion Aquacer531: BYK Chemie Japan Co., Ltd., oxidized high-density polyethylene WAX emulsion Crosslinking agent a: Oxazoline group-containing polymer (oxazoline group equivalent 220 g / mol, weight average molecular weight 40,000, glass transition temperature 50°C)
Cross-linking agent b: polycarbodiimide resin (carbodiimide group equivalent 430 g/mol, viscosity 100 mPa s)
BDG: Nippon Emulsifier Co., Ltd., diethylene glycol monobutyl ether KF-6011: Shin-Etsu Chemical Co., Ltd., PEG-11 methyl ether dimethicone (polyether-modified silicone surfactant)
PET: manufactured by Futamura Chemical Co., Ltd., trade name: Taiko polyester film FE2001
OPP: manufactured by Futamura Chemical Co., Ltd., trade name: FOR-AQ

[Production Example 1] Core-Shell Emulsion A flask equipped with a dropping funnel, a stirrer, a nitrogen gas inlet tube, a thermometer and a reflux condenser was charged with 520 parts of deionized water. In a dropping funnel, 163 parts of deionized water, 80 parts of a 25% aqueous solution of emulsifier [manufactured by ADEKA Co., Ltd., trade name: Adekari Soap SR-10], 322 parts of cyclohexyl methacrylate, 103 parts of 2-ethylhexyl acrylate, 2-hydroxy A pre-emulsion for the first stage dropping was prepared from 75 parts of ethyl methacrylate, of which 44 parts corresponding to 3% of the total amount of all monomer components was added to the flask, and the temperature was raised to 70°C while gently blowing nitrogen gas. Then, 30 parts of a 5% aqueous ammonium persulfate solution was added to initiate polymerization. Thereafter, the remainder of the pre-emulsion for dropping was uniformly dropped into the flask over 120 minutes.

After completion of dropping, the contents of the flask were maintained at 70° C. for 60 minutes, followed by 163 parts of deionized water and 80 parts of a 25% aqueous solution of an emulsifier [manufactured by ADEKA Co., Ltd., trade name: Adekari Soap SR-10]. , 310 parts of cyclohexyl methacrylate, 105 parts of 2-ethylhexyl acrylate, 75 parts of 2-hydroxyethyl methacrylate and 4-(meth)acryloyloxy-1,2,2,6,6-pentamethylpiperidine [manufactured by ADEKA Corporation, commercial Name: Adekastab LA-82] 10 parts of pre-emulsion for second stage dropping and 30 parts of 5% ammonium persulfate aqueous solution were uniformly dropped into the flask over 120 minutes.

After the dropwise addition was completed, the contents of the flask were maintained at 70° C. for 60 minutes, and the pH was adjusted to 8 by adding 25% aqueous ammonia to complete the polymerization. After cooling the obtained reaction solution to room temperature, an aqueous dispersion was prepared by filtering through a 300-mesh wire mesh. The obtained aqueous dispersion contains a polymer, and the obtained polymer is a resin emulsion, which is a two-layered emulsion particle having an inner layer and an outer layer. The content of non-volatile matter in this aqueous dispersion was 50%, the acid value derived from the carboxyl groups of the polymer was 0 mgKOH/g, and the glass transition of the inner layer resin constituting the resin emulsion particles contained in the emulsion was The temperature was 32°C and the glass transition temperature of the outer layer resin was 32°C. The minimum film-forming temperature was 40° C. and the average particle size was 200 nm.

[Production Examples 2-7, 10-18, Comparative Production Example 1-3]
A polymer was prepared in the same manner as in Production Example 1, except that the monomer components shown in Tables 1 to 6 were polymerized. The results are shown in Tables 1-6.

[Production Example 8] Single Emulsion A flask equipped with a dropping funnel, a stirrer, a nitrogen gas inlet tube, a thermometer and a reflux condenser was charged with 536 parts of deionized water. In a dropping funnel, 326 parts of deionized water, 160 parts of a 25% aqueous solution of emulsifier [manufactured by ADEKA Co., Ltd., trade name: Adekari Soap SR-10], 632 parts of cyclohexyl methacrylate, 208 parts of 2-ethylhexyl acrylate, 2-hydroxy A pre-emulsion for first-stage dropping was prepared, comprising 150 parts of ethyl methacrylate and 10 parts of 4-methacryloyloxy-2,2,6,6-tetramethylpiperidine [manufactured by ADEKA Co., Ltd., trade name: ADEKA STAB LA-87]. 74 parts of 5% of the total amount of all monomer components was added to the flask, the temperature was raised to 70°C while slowly blowing nitrogen gas, and 30 parts of a 5% aqueous ammonium persulfate solution was added to initiate polymerization. did. Thereafter, the remainder of the pre-emulsion for dropping and 30 parts of a 5% aqueous ammonium persulfate solution were uniformly dropped into the flask over 180 minutes.

After the dropwise addition was completed, the contents of the flask were maintained at 70° C. for 60 minutes, and the pH was adjusted to 8 by adding 25% aqueous ammonia to complete the polymerization. After cooling the obtained reaction solution to room temperature, an emulsion was prepared by filtering through a 300-mesh wire mesh. The content of non-volatile matter in this emulsion was 50%, the acid value derived from the carboxyl groups of the resin emulsion particles was 0 mgKOH/g, and the resin constituting the resin emulsion particles contained in the emulsion had a glass transition temperature of 32. °C. The minimum film-forming temperature was 40° C. and the average particle size was 200 nm.
[Production Example 9, Comparative Production Example 4]
A polymer was prepared in the same manner as in Production Example 8, except that the monomer components shown in Table 3 were used for polymerization. Table 3 shows the results.

[Example 1]
To 81.8 parts of the resin emulsion obtained in Production Example 1 was added 18.2 parts of WS-700 (manufactured by Nippon Shokubai Co., Ltd.) as a cross-linking agent ^. An aqueous dispersion containing a polymer having a polymer-derived structural unit and a cross-linking agent was obtained. The amount of coarse particles of 1 μm or more in the resulting aqueous dispersion was less than 100×10 ⁶ μm ³ /ml.

[Example 2-18, Comparative Example 1-4]
Aqueous dispersions of Examples 2-18 and Comparative Examples 1-4 were obtained in the same manner as in Example 1, except that the cross-linking agents and wax components shown in Tables 7 to 9 were used.

[White paste]
420 parts of deionized water, 88 parts of a dispersing agent [Disperbyk-190 manufactured by BYK-Chemie Japan], 60 parts of propylene glycol, 1000 parts of titanium oxide [JR-403 manufactured by Tayca] and 200 parts of glass beads (diameter 1 mm) It was prepared by dispersing with a disper at a rotation speed of 3000 min ⁻¹ for 120 minutes and then filtering through a 300-mesh wire mesh.

[Experimental example 1]
To 38.0 parts of the emulsion obtained in Example 1, 18.6 parts of white paste, 20 parts of propylene glycol, diethylene glycol monobutyl ether ( ^BDG , SP value 9 .5) Add 10 parts, 0.4 parts of a surfactant [KF-6011, manufactured by Shin-Etsu Chemical Co., Ltd.], and deionized water so that the total becomes 100 parts, and stir for an additional 30 minutes. A water-based ink was prepared by filtering through a filter [MCP-3-C10S, manufactured by Advantech].

[Experimental Example 2-18, Comparative Experimental Example 1-4]
In Experimental Example 1, water-based inks were prepared with the compositions shown in Tables 11 to 16 to obtain water-based inks of Experimental Examples 2-18 and Comparative Experimental Examples 1-4.

<Production of inkjet printed matter>
Water-based ink is applied to a print evaluation device [manufactured by Genesis Co., Ltd.] equipped with an inkjet print head [manufactured by Kyocera Corporation, product number: KJ4B-YH06WST-STDV] in air at a temperature of 25 ± 1 ° C and a relative humidity of 30 ± 5%. was filled.
Next, in the print evaluation device, the head voltage was set to 26 V, the frequency to 4 kHz, the ejected droplet volume to 12 pL (picoliters), the head temperature to 32° C., the resolution to 600 dpi, and the negative pressure to −4.0 kPa. set to A corona-treated polyester film [manufactured by Futamura Chemical Co., Ltd., trade name: Taiko polyester film FE2001] and a corona-treated OPP film [manufactured by Futamura Chemical Co., Ltd., trade name: FOR-AQ] were used as recording media, and the longitudinal direction of the film was measured. and the conveying direction are the same. A print command is transferred to the print evaluation device, and a solid image is printed on the film by an inkjet recording method with a water-based ink in an amount of 100% (12 pL, 600 x 600 dpi). was dried for 10 seconds to obtain PET and OPP test sheets.

-Evaluation method-
<Scratch resistance>
The printed image on each test sheet was rubbed with a nylon nonwoven fabric, and scratch resistance was evaluated based on the following evaluation criteria. Tables 11 to 16 show the evaluation results of each experimental example and comparative experimental examples.
〔Evaluation criteria〕
5: Even if the printed image is rubbed, the image is not peeled off at all.
4: The image peels off only slightly when the printed image is rubbed.
3: The image is slightly peeled off when the printed image is rubbed.
2: When the printed image is rubbed, the image is slightly peeled off.
1: When the printed image is rubbed, the image is clearly peeled off.
0: The image is easily peeled off when the printed image is rubbed.
<Water resistance>
The printed image on each test sheet was rubbed with a wet nylon nonwoven fabric, and water resistance was evaluated based on the following evaluation criteria. Tables 11 to 16 show the evaluation results of each experimental example and comparative experimental examples.
〔Evaluation criteria〕
5: Even if the printed image is rubbed, the image is not peeled off at all.
4: The image peels off only slightly when the printed image is rubbed.
3: The image is slightly peeled off when the printed image is rubbed.
2: When the printed image is rubbed, the image is slightly peeled off.
1: When the printed image is rubbed, the image is clearly peeled off.
0: The image is easily peeled off when the printed image is rubbed.

<Adhesion>
Adhesive tape (Cellotape (registered trademark) No. 405, 24 mm width, manufactured by Nichiban Co., Ltd.) was attached to each test sheet in a room temperature environment, and left to stand for 1 minute. Thereafter, the adhesiveness was evaluated based on the evaluation criteria below by peeling off in the direction of 180°. Tables 11 to 16 show the evaluation results of each experimental example and comparative experimental examples.
〔Evaluation criteria〕
5: The printed image is not peeled off at all.
4: 1 to 20% of the printed image is peeled off.
3: 21 to 50% of the printed image is peeled off.
2: 51 to 75% of the printed image is peeled off.
1: 76 to 100% of the printed image is peeled off.
<Blocking resistance>
A polyester film not subjected to corona treatment was superimposed on the printed surface of each test sheet, and a load of 2 N/cm ² was applied to the polyester film in the air at 25 ° C. for 1 hour, and then the polyester film was removed. The film was peeled off quickly, and the feeling of resistance at that time was observed, and the blocking resistance was evaluated based on the following evaluation criteria. Tables 11 to 16 show the evaluation results of each experimental example and comparative experimental examples.
〔Evaluation criteria〕
5: No resistance is felt when the polyester film is peeled off.
4: Very little resistance is felt when the polyester film is peeled off.
3: Only a little resistance is felt when the polyester film is peeled off.
2: Resistance is clearly felt when the polyester film is peeled off.
1: Strong resistance is felt when the polyester film is peeled off.
0: Very strong resistance is felt when the polyester film is peeled off.

<Image uniformity>
The printed surface of each test sheet was visually observed, and image uniformity was evaluated based on the following evaluation criteria. Tables 11 to 16 show the evaluation results of each experimental example and comparative experimental examples.
〔Evaluation criteria〕
5: No white streaks and color unevenness are observed on the printed surface.
4: White streaks and color unevenness are observed on the printed surface at a rate of less than 5%.
3: White streaks and color unevenness are observed on the printed surface at a rate of 5% or more and less than 10%.
2: White streaks and color unevenness are observed on the printed surface at a rate of 10% or more and less than 15%.
1: White streaks and color unevenness are observed on the printed surface at a rate of 15% or more and less than 20%.
0: White streaks and color unevenness are observed on the printed surface at a rate of 20% or more.

Claims (8)

An aqueous dispersion containing a polymer (A) having a structural unit derived from a hydroxyl group-containing monomer and a cross-linking agent (B). 2. The aqueous dispersion according to claim 1, wherein the polymer (A) contains 5 parts by mass or more and 30 parts by mass or less of the structural unit derived from the hydroxyl group-containing monomer with respect to 100 parts by mass of the polymer (A). 3. The aqueous dispersion according to claim 1, wherein the polymer (A) has an average particle size of 150 to 300 nm. 4. The aqueous dispersion according to any one of claims 1 to 3, wherein the mass ratio of the polymer (A) and the cross-linking agent (B) is 99/1 to 70/30. The aqueous dispersion according to any one of claims 1 to 4, further comprising a wax component (C). An aqueous ink comprising the aqueous dispersion according to any one of claims 1 to 5, a colorant, and a dispersant. 7. The water-based ink according to claim 6, wherein the colorant is a white pigment. A printed matter comprising a printed layer formed from the water-based ink according to claim 6 or 7.