JP3329771B2 - Water-based printing ink - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aqueous printing ink having excellent pigment dispersibility, adhesion and re-dissolving property.

[0002]

2. Description of the Related Art Heretofore, organic inks have often been used as printing inks. However, in recent years, water-based printing inks have been developed due to safety and health problems such as explosion fires and pollution problems such as water pollution and air pollution. Conventional aqueous printing inks are polyethylene terephthalate (PE)
Nothing adhered to both polar substrates such as T) and nylon (NY) and non-polar substrates such as polyolefin such as polyethylene (PE) and polypropylene (PP). In order to improve this point, blending and copolymerization of acrylic and urethane have been studied as disclosed in JP-A-6-80930 and JP-A-10-139839.

[0003]

However, in the method described in JP-A-6-80930, since the acrylic resin is produced in the polyurethane emulsion, the polyurethane resin and the acrylic resin are basically mixed. It is. Originally, the acrylic resin and the urethane resin have poor compatibility, and thus the adhesion of the printed film after water is scattered tends to be poor. Further, the method described in JP-A-10-139839 does not use a chain transfer agent during resin production, and a polyurethane-based resin having two or more ethylenically unsaturated double bonds in one molecule is produced. When copolymerized with a vinyl monomer, gelation tends to occur.

An object of the present invention is to provide an aqueous printing ink which is excellent in adhesion to any substrate including a polyolefin-based substrate, pigment dispersibility, and re-dissolving property.

[0005]

That is, the present invention provides the following (1) to (8). (1) An aqueous emulsion comprising, as a resin component, a self-emulsifiable copolymer in which a hydrophilic polar group-containing ethylenically unsaturated monomer and a mercapto group-containing urethane prepolymer are bonded by radical polymerization. Printing ink.

(2) An aqueous emulsion containing, as a resin component, a self-emulsifiable copolymer in which an ethylenically unsaturated monomer and a urethane prepolymer containing a mercapto group and a hydrophilic polar group are bonded by radical polymerization;
Water-based printing ink characterized by the following.

(3) An ethylenically unsaturated monomer, an organic polyisocyanate, a compound containing a mercapto group and an active hydrogen group, and a compound containing a hydrophilic polar group and an active hydrogen group are combined by urethanation reaction and radical polymerization. An aqueous printing ink comprising an aqueous emulsion containing a self-emulsifiable copolymer as a resin component.

(4) The aqueous printing ink of (2) or (3), wherein the ethylenically unsaturated monomer is an ethylenically unsaturated monomer containing at least a hydrophilic polar group-containing ethylenically unsaturated monomer.

(5) The aqueous printing ink of (2) or (3), wherein the ethylenically unsaturated monomer is an ethylenically unsaturated monomer containing at least a keto group or aldehyde group-containing ethylenically unsaturated monomer.

(6) The urethane prepolymer containing a mercapto group and a hydrophilic polar group is a urethane prepolymer further containing an ethylenically unsaturated double bond in addition to the mercapto group and the hydrophilic polar group. , (4) or (5).

(7) The urethane prepolymer containing a mercapto group and a hydrophilic polar group is a urethane prepolymer further containing a keto group or an aldehyde group in addition to the mercapto group and the hydrophilic polar group, or a mercapto group and a hydrophilic polar group. And the aqueous printing ink of (2), (4) or (5), which is a urethane prepolymer further containing a keto group or an aldehyde group in addition to the ethylenically unsaturated double bond.

(8) An aqueous printing ink comprising the aqueous printing ink according to (5), (6) or (7) and a polyfunctional hydrazide compound.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
The self-emulsifiable copolymer in the present invention has a hydrophilic polar group introduced into one or both of the acrylic segment and the urethane segment. This self-emulsifiable copolymer was obtained by radical polymerization of an ethylenically unsaturated double bond of an ethylenically unsaturated monomer or simultaneously with a urethanization reaction using a mercapto group of a urethane prepolymer or a component thereof as a chain transfer agent. Of structure.

The constituent components of the self-emulsifying copolymer in the present invention will be described. In forming the acrylic segment in the self-emulsifying copolymer of the present invention, a hydrophilic polar group-containing ethylenically unsaturated monomer, a keto group or an aldehyde group-containing ethylenically unsaturated monomer, and other ethylenically unsaturated monomers are used. Can be These can be used alone or as a mixture of any combination, but an ethylenically unsaturated monomer (mixture) containing at least a hydrophilic polar group-containing ethylenically unsaturated monomer,
Alternatively, an ethylenically unsaturated monomer (mixture) containing at least an ethylenically unsaturated monomer containing a keto group or an aldehyde group is preferable, and in this case, an ethylenically unsaturated monomer containing 50 to 95 mol% of other ethylenically unsaturated monomers Monomers (mixtures) are preferred. More specifically, these ethylenically unsaturated monomers are more preferably acrylic monomers in view of compatibility with water and urethane resin. In the present invention, in order to impart self-emulsifiability to the obtained copolymer, it is better to introduce a hydrophilic polar group into both the acrylic segment and the urethane segment, thereby imparting self-emulsifiability to the copolymer with a small amount of introduction. However, when a hydrophilic polar group is introduced into only one of them, introduction into a urethane segment is advantageous in producing a self-emulsifying copolymer.

The hydrophilic polar group-containing ethylenically unsaturated monomers include poly (oxyalkylene) ether glycol monoacrylate and poly (oxyalkylene)
For compounds having an ethylenically unsaturated double bond and an epoxy group, such as ether glycol monomethacrylate, poly (oxyalkylene) ether glycol monoalkyl ether acrylate, poly (oxyalkylene) ether glycol monoalkyl ether methacrylate, glycidyl acrylate and glycidyl methacrylate. Oxyethylene group-containing ethylenically unsaturated monomers such as poly (oxyethylene) chain-containing ethylenically unsaturated monomers such as compounds to which alkylene oxides are added, compounds represented by Formula 1, etc., and acrylic acid, methacrylic acid, and maleic acid. Acids, maleic anhydride, maleic acid monoesters,
Carboxylic acid-containing ethylenically unsaturated monomers such as fumaric acid, fumaric acid monoesters, itaconic acid, itaconic acid monoesters, sulfonated styrene, sulfonated α-
Methylstyrene, acid-containing ethylenically unsaturated monomers such as sulfonic acid-containing ethylenically unsaturated monomers such as compounds represented by the following formulas 2 or 3, allylamine, N, N
-Dimethylaminoethyl acrylate, N, N-dimethylaminoethyl methacrylate, N, N-diethylaminoethyl acrylate, N, N-diethylaminoethyl methacrylate, those obtained by adding an alkylene oxide thereto, primary compounds such as the compound represented by the formula 4 And base-containing ethylenically unsaturated monomers such as secondary and tertiary amino group-containing ethylenically unsaturated monomers.

[0016]

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[0017]

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[0018]

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[0019]

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Examples of the ethylenically unsaturated monomer containing a keto group or an aldehyde group include acrolein, diacetone acrylamide, diacetone methacrylamide, formylstyrene, vinyl methyl ketone, vinyl ethyl ketone, vinyl butyl ketone, vinyl acetophenone, vinyl benzophenone, acrylic Oxypropenal, diacetone acrylate, acetonitrile acrylate,
2-hydroxypropyl acrylate acetyl acetate, butanediol-1,4-acrylate acetyl acetate, methacryloxypropenal, diacetone methacrylate, acetonitrile methacrylate,
-Hydroxypropyl methacrylate acetyl acetate, butanediol-1,4-methacrylate acetyl acetate, and the like.

Other ethylenically unsaturated monomers include alkyl acrylate, cycloalkyl acrylate,
Acrylic esters such as phenyl acrylate, benzyl acrylate, and glycidyl acrylate; alkyl methacrylates, cycloalkyl methacrylates; methacrylates such as phenyl methacrylate, benzyl methacrylate, and glycidyl methacrylate; vinyl acetate; propionic acid Vinyl ester compounds such as vinyl; vinyl alkyl ethers such as vinyl methyl ether; vinyl ether compounds such as vinyl cyclohexyl ether, vinyl phenyl ether, vinyl benzyl ether and vinyl glycidyl ether; vinyl cyanide compounds such as acrylonitrile and methacrylonitrile , Aromatic compounds containing ethylenically unsaturated double bonds such as styrene, vinyltoluene and α-methylstyrene, and halogenated vinyls such as vinyl chloride and vinyl bromide. , Vinylidene halides such as vinylidene chloride, vinylidene bromide, etc .; maleic acid diesters such as dialkyl maleate; fumaric acid diesters such as dialkyl fumarate; itaconic acid diesters such as dimethyl itaconate; Dialkylacrylamides such as dimethylacrylamide, N-vinylpyrrolidone, heterocyclic vinyl compounds such as 2-vinylpyridine, etc.
2-hydroxyethyl acrylate, hydroxypropyl acrylate, polyethylene glycol monoacrylate, polypropylene glycol monoacrylate, 2
-Hydroxyethyl acrylate ε-caprolactone adduct, 2-hydroxyethyl acrylate β-methyl-γ-valerolactone adduct, glycerol monoacrylate, hydroxyl group-containing acrylates such as glycerol diacrylate, 2-hydroxyethyl methacrylate, hydroxy Propyl methacrylate, polyethylene glycol monomethacrylate, polypropylene glycol monomethacrylate, ε-caprolactone adduct of 2-hydroxyethyl methacrylate, β-methyl-γ-valerolactone adduct of 2-hydroxyethyl methacrylate, glycerol monomethacrylate, glycerol dimethacrylate, etc. Hydroxyl-containing methacrylates, allyl alcohol, glycerol monoallyl ether, Allyl compounds such as roll diallyl ether. Of these, preferred are 2-hydroxyethyl acrylate,
Active hydrogen group-containing ethylenically unsaturated monomers such as ε-caprolactone adduct of hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, and ε-caprolactone adduct of 2-hydroxyethyl methacrylate.

Examples of the radical polymerization initiator used for radical polymerization of the ethylenically unsaturated monomer include, for example,
2,2'-azobisisobutyronitrile, 2,2'-azobis-2-methylbutyronitrile, dimethyl 2,2'-azobisisobutyrate, azobiscyanovaleric acid, 1,1 '
-Azobis- (cyclohexane-1-carbonitrile), 2,2'-azobis- (2,4-dimethylvaleronitrile), 2,2'-azobis- (4-methoxy-
Azo compounds such as 2,4-dimethylvaleronitrile),
1,1-bis (t-butylperoxy) -3,3,5-
Trimethylcyclohexane, 1,1-bis (t-hexylperoxy) cyclohexane, 1,1-bis (t-hexylperoxy) -3,3,5-trimethylcyclohexane, 1,1-bis (t-butylperoxy) ) Cyclohexane, 1,1-bis (t-butylperoxy) cyclododecane, n-butyl-4,4-bis (t-butylperoxy) valerate, 2,2-bis (t-butylperoxy) butane, t-butyl hydroperoxide,
Diisopropylbenzene hydroperoxide, p-
Menthol hydroperoxide, t-hexyl peroxide, 1,1,3,3-tetramethylbutyl peroxide, t-butylcumyl peroxide, dicumyl peroxide, di-t-butyl peroxide, isobutyryl peroxide, 3,5,5-trimethylhexanoyl peroxide, octanoyl peroxide, lauroyl peroxide, stearoyl peroxide, succinic peroxide, benzoyl peroxide, toluylbenzoyl peroxide, diisopropylperoxydicarbonate, di-n-propyl Peroxydicarbonate, bis (4-t-butylcyclohexyl) peroxydicarbonate, di-2-ethoxyethylperoxydicarbonate, di-2-methoxybutylperoxydi Boneto, di-2-ethylhexyl peroxydicarbonate, di (3-methyl-3-
Methoxybutyl) peroxydicarbonate, α, α '
Bis (neodecanoylperoxy) diisopropylbenzene, cumylperoxyneodecanoate, 1,1,
3,3-tetramethylbutyl peroxy neodecanoate, 1-cyclohexyl-1-methylethyl peroxy neodecanoate, t-hexyl peroxy neodecanoate, t-butyl peroxy neodecanoate, t −
Hexyl peroxypivalate, t-butyl peroxypivalate, 2,5-dimethyl-2,5-bis (2-ethylhexylperoxy) hexane, 1,1,3,3-
Tetramethylbutylperoxy-2-ethylhexanoate, 1-cyclohexyl-1-methylethylperoxy-2-ethylhexanoate, t-hexylperoxy-2-ethylhexanoate, t-butylperoxy- 2-ethylhexanoate, t-butylperoxyisobutyrate, t-butylperoxylaurate, t-
Butylperoxy-3,5,5-trimethylhexanate, t-hexylperoxyisopropyl monocarbonate, t-butylperoxyisopropyl monocarbonate, t-butylperoxy-2-ethylhexyl monocarbonate, 2,5-dimethyl- 2,5-bis (benzoylperoxy) hexane, 2,5-dimethyl-2,
5-bis (m-toluoylperoxy) hexane, t-
Organic peroxides such as butylperoxyacetate, t-hexylperoxybenzoate, t-butylperoxy-m-toluoylbenzoate, t-butylperoxybenzoate, bis (t-butylperoxy) isophthalate, and the like. .

The mercapto group-containing urethane prepolymer used in the present invention includes, for example, an organic polyisocyanate, a compound containing a mercapto group and an active hydrogen group,
It is a reaction product with a compound containing an active hydrogen group if desired. The urethane prepolymer containing a mercapto group and a hydrophilic polar group can be obtained by reacting a compound containing a hydrophilic polar group and an active hydrogen group with each of the above raw materials. The active hydrogen group is a group having a reactivity with an isocyanate group or higher than a mercapto group, that is, a hydroxyl group, an amino group, an imino group, a mercapto group, or the like.

The organic polyisocyanate includes
4,4'-diphenylmethane diisocyanate, 2,
4'-diphenylmethane diisocyanate, 2,2'-
Diphenylmethane diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 4,4'-diphenyl ether diisocyanate,
2-nitrodiphenyl-4,4'-diisocyanate,
2,2'-diphenylpropane-4,4'-diisocyanate, 3,3'-dimethyldiphenylmethane-4,
4'-diisocyanate, 4,4'-diphenylpropane diisocyanate, 1,2-phenylene diisocyanate, 1,3-phenylene diisocyanate, 1,4-
Phenylene diisocyanate, 1,4-naphthalene diisocyanate, 1,5-naphthalene diisocyanate,
Aromatic diisocyanate such as 3,3'-dimethoxydiphenyl-4,4'-diisocyanate, aliphatic diisocyanate such as 1,6-hexamethylene diisocyanate, 1,4-tetramethylene diisocyanate, lysine diisocyanate, o-xylene diisocyanate, m −
Aromatic diisocyanates such as xylene diisocyanate, p-xylene diisocyanate, tetramethyl xylene diisocyanate, etc., isophorone diisocyanate, hydrogenated toluene diisocyanate, hydrogenated xylene diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated tetramethyl xylene diisocyanate, etc. Is mentioned.
Further, modified adducts of these organic diisocyanates,
So-called modified polyisocyanates such as a buret modified product, an isocyanurate modified product, a uretonimine modified product, a uretdione modified product, and a carbodiimide modified product can also be used. Further, such as polyphenylene polymethylene polyisocyanate, crude toluene diisocyanate, etc.
A polyisocyanate which is a so-called polymeric body can also be used. These organic polyisocyanates can be used alone or in combination of two or more. Among these organic polyisocyanates, aliphatic and alicyclic polyisocyanates are preferable when considering weather resistance and the like, and in particular, hexamethylene diisocyanate, isophorone diisocyanate, hydrogenated xylylene diisocyanate, and hydrogenated diphenylmethane diisocyanate are most preferred. preferable.

As the compound containing a mercapto group and an active hydrogen group to be reacted with the organic polyisocyanate, hydroxythiol and aminothiol are preferred.

Examples of the hydroxythiol include 2-mercapto-1-hydroxyethane, 2-mercapto-1-hydroxypropane, 1-mercapto-2-hydroxypropane, 3-mercapto-1-hydroxypropane,
Monomercaptomonool compounds such as mercapto-1-hydroxybutane, 3-mercapto-1-hydroxybutane, 4-mercapto-1-hydroxybutane, thioglycerol, 2,3-dihydroxy-1-mercaptobutane, 2,3 -Dihydroxy-1-mercaptopentane, 3,4-dihydroxy-1-mercaptobutane,
3,4-dihydroxy-1-mercaptopentane, 3,
Monomercaptodiol compounds such as 4-dihydroxy-1-mercaptohexane, 2-hydroxy-1,3-dimercaptopropane, 1-hydroxy-2,3-dimercaptopropane, 2-hydroxy-1,3-dimercaptobutane , 1-hydroxy-2,3-dimercaptobutane, 2-hydroxy-1,3-dimercaptopentane,
2-hydroxy-1,3-dimercaptohexane, 3-
And dimercaptomonool compounds such as hydroxy-1,4-dimercaptobutane, 3-hydroxy-1,4-dimercaptopentane, and 3-hydroxy-1,4-dimercaptohexane.

Examples of the aminothiol include β-mercaptoethylamine, β-mercaptopropylamine, γ-mercaptopropylamine, 2-aminothiophenol,
3-aminothiophenol, 4-aminothiophenol and the like can be mentioned.

These compounds containing a mercapto group and an active hydrogen group may be used alone or in combination of two or more. Preferred compounds containing a mercapto group and an active hydrogen group used in the present invention are 2-mercapto-1-hydroxyethane, thioglycerol, β-
Mercaptoethylamine.

Examples of the compound containing an active hydrogen group (other than a mercapto group) to be reacted with an organic polyisocyanate include those which are called long-chain polyols in the polyurethane industry and those which are called chain extenders. In the present invention, the urethane prepolymer containing a mercapto group and a hydrophilic polar group preferably contains 50 to 90% by weight of a long-chain polyol.

Examples of the long-chain polyol include polyester polyols, polycarbonate polyols, polyether polyols, polyolefin polyols, animal and plant polyols, and copolyols thereof.
These long-chain polyols may be used alone or in combination of two or more.

Examples of the polyester polyol include known succinic acid, adipic acid, sebacic acid, azelaic acid, terephthalic acid, isophthalic acid, orthophthalic acid, hexahydroterephthalic acid, hexahydroisophthalic acid, hexahydroorthophthalic acid, and naphthalenedicarboxylic acid. , One or more polycarboxylic acids such as trimellitic acid, acid esters, or acid anhydrides, and ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-
Butanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, neopentyl glycol, 1,8- Octanediol, 1,9-nonanediol, diethylene glycol,
Dipropylene glycol, 1,4-cyclohexane dimethanol, or ethylene oxide or propylene oxide adduct of bisphenol A, low molecular weight polyols such as trimethylolpropane, glycerin, pentaerythritol, hexamethylenediamine, xylylenediamine, isophoronediamine, etc. And a polyester polyol or polyester amide polyol obtained by a dehydration condensation reaction with at least one of low molecular weight polyamines, low molecular weight amino alcohols such as monoethanolamine and diethanolamine.

Lactone-based polyester polyols obtained by ring-opening polymerization of cyclic ester (lactone) monomers such as ε-caprolactone and γ-valerolactone using low molecular polyols, low molecular polyamines and low molecular amino alcohols as initiators. No.

Examples of the polycarbonate polyol include those obtained by a dealcoholation reaction, a dephenolization reaction, or the like of the low-molecular-weight polyol used in the synthesis of the above-mentioned polyester polyol and diethylene carbonate, dimethyl carbonate, diethyl carbonate, diphenyl carbonate, or the like. Can be

Examples of the polyether polyol include polyethylene glycol obtained by ring-opening polymerization of ethylene oxide, propylene oxide, tetrahydrofuran, or the like using the low-molecular polyol, low-molecular polyamine, or low-molecular amino alcohol used in the polyester polyol described above as an initiator. Examples thereof include polypropylene glycol, polytetramethylene ether glycol, and the like, and polyether polyols obtained by copolymerizing them, and polyester ether polyols using the above-described polyester polyols and polycarbonate polyols as initiators.

Examples of the polyolefin polyol include hydroxyl group-containing polybutadiene, hydrogenated hydroxyl group-containing polybutadiene, hydroxyl group-containing polyisoprene, hydrogenated hydroxyl group-containing polyisoprene, hydroxyl group-containing chlorinated polypropylene, and hydroxyl group-containing chlorinated polyethylene.

The animal and plant polyols include castor oil polyols and silk fibroin.

If the compound has two or more active hydrogen groups, in addition to the dimer acid polyol and the hydrogenated dimer acid polyol, an epoxy resin, a polyamide resin,
Resins such as polyester resin, acrylic resin, rosin resin, urea resin, melamine resin, phenol resin, coumarone resin, and polyvinyl alcohol can also be suitably used as the long-chain polyol.

The number average molecular weight of these long-chain polyols is preferably from 500 to 10,000, particularly preferably from 1,000 to 5,000. In the present invention, considering the adhesion as an aqueous ink, durability and the like, polyester polyol,
More preferably, the long-chain polyol contains 50 to 100% by weight of either a polycarbonate polyol or a dimer acid-based polyol.

The chain extender is a compound containing two or more active hydrogen groups in a molecule having a number average molecular weight of less than 500,
Specifically, the above-mentioned low molecular polyol, low molecular polyamine, low molecular amino alcohol and the like can be mentioned.

In the aqueous printing ink of the present invention, when a compound containing an active hydrogen group which reacts with an organic polyisocyanate and an ethylenically unsaturated double bond is used in the production of a self-emulsifying copolymer, the molecular weight can be reduced. It is preferable because control becomes easy. In this case, the acrylic oligomer and urethane have a grafted structure, and the acrylic segment and the urethane segment form a self-emulsifiable copolymer linked by a group generated by radical polymerization of an ethylenically unsaturated double bond. Will be included. Examples of the compound containing an active hydrogen group and an ethylenically unsaturated double bond include ethylenically unsaturated monomers containing an active hydrogen group among the other ethylenically unsaturated monomers described above. Of these, preferred are 2-hydroxyethyl acrylate, ε-caprolactone adduct of 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, and ε-caprolactone adduct of 2-hydroxyethyl methacrylate.

The hydrophilic polar group of the compound containing a hydrophilic polar group and an active hydrogen group to be reacted with an organic polyisocyanate may be a hydrophilic nonionic group, a hydrophilic anionic group, a hydrophilic cationic group, or a hydrophilic amphoteric group. Group. The hydrophilic nonionic group is a portion of a repeating unit of an oxyethylene group introduced into the main chain or side chain of the resin. Hydrophilic anionic group, carboxylic acid, sulfonic acid, phosphoric acid, phosphonic acid,
It comprises an acid such as phosphinic acid, thiosulfonic acid and the like, and a basic neutralizing agent described later. The acid component is directly linked to the self-emulsifying copolymer, but the neutralizing agent is not directly linked to the copolymer. The hydrophilic cationic group comprises a base such as a tertiary amino group and an acidic neutralizing agent described later. The base component is directly linked to the self-emulsifying copolymer, but the neutralizing agent is not directly linked to the copolymer.

Specifically, compounds containing a hydrophilic nonionic group and an active hydrogen group include poly (oxyalkylene) ether polyols having at least one active hydrogen group,
Poly (oxyalkylene) having at least one active hydrogen group
Fatty acid ester polyols and the like. The poly (oxyalkylene) ether polyol having one or more active hydrogen groups can be obtained by addition-polymerizing an alkylene oxide using a compound having one or more active hydrogen groups as an initiator. The initiator includes methanol, ethanol,
Propanol, n-butanol, cyclohexanol,
Phenol, ethylene glycol, propylene glycol, aniline, trimethylolpropane, glycerin,
Pentaerythritol and the like. Of these, the molecular weight is smaller, such as ethylene glycol,
Bifunctional ones are preferred. Examples of the alkylene oxide include ethylene oxide and propylene oxide. Note that a compound having an epoxy group such as styrene oxide, epichlorohydrin, or butyl glycidyl ether may be used as a part of the alkylene oxide. In addition, examples of the fatty acid used for producing the poly (oxyalkylene) fatty acid ester polyol having one or more active hydrogen groups include acetic acid, propionic acid, and butyric acid. The polyether chains present in the above-mentioned raw materials are preferably those having 3 to 300, especially 5 to 200, and having 50 mol% or more, particularly 60 mol% or more of oxyethylene groups.

Compounds containing a hydrophilic anionic group-forming group and an active hydrogen group include α-hydroxypropionic acid, hydroxysuccinic acid, dihydroxysuccinic acid, ε
-Hydroxypropane-1,2,3-tricarboxylic acid,
Hydroxyacetic acid, α-hydroxybutyric acid, hydroxystearic acid, ricinoleic acid, ricinoleic acid, ricinostearol acid, salicylic acid, mandelic acid, etc., oleic acid, ricinoleic acid, hydroxy hydroxylated unsaturated fatty acids such as linoleic acid Fatty acids, glutamine, asparagine, lysine, diaminopropionic acid, ornithine,
Diamine-type amino acids such as diaminobenzoic acid and diaminobenzenesulfonic acid; monoamine-type amino acids such as glycine, alanine, glutamic acid, taurine, aminocaproic acid, aminobenzoic acid, aminoisophthalic acid, and sulfamic acid; or 2,2-dimethylolpropion acid,
A carboxylic acid-containing polyol such as 2,2-dimethylolbutyric acid or 2,2-dimethylolvaleric acid, a chelate type such as a 1: 1 (molar ratio) adduct of iminodiacetic acid and glycidol, and 5-sulfoisophthalic acid skeleton were introduced. Polyester polyol, polycaprolactone using water or a carboxyl group-containing alcohol as an initiator, an ester exchange product between an active hydrogen group-containing polyester and a carboxyl group-containing alcohol, an ester exchange product between an active hydrogen group-containing polycarbonate and a carboxyl group-containing alcohol, and the like. No. Further, the above-mentioned long-chain polyols and low-molecular-weight glycols, trimethylolpropane, low-molecular-weight polyols and polyamines such as glycerin, and a half-ester mixture containing a carboxyl group obtained by reacting with a polycarboxylic acid anhydride, Half amide mixtures can also be used. In particular, when a polyol is added to a dianhydride such as pyromellitic anhydride, two carboxylic acids are generated, so that a hydrophilic anionic group can be introduced into the molecular chain of the polyester polyol. As a basic neutralizing agent for forming a hydrophilic anionic group, ethylamine,
Trimethylamine, triethylamine, triisopropylamine, tributylamine, triethanolamine,
N-methyldiethanolamine, N-phenyldiethanolamine, monoethanolamine, dimethylethanolamine, diethylethanolamine, morpholine, N
Organic amines such as -methylmorpholine, 2-amino-2-ethyl-1-propanol and pyridine; alkali metals such as lithium, potassium and sodium; inorganic alkalis such as sodium hydroxide and potassium hydroxide; and ammonia. Can be Preferred among these are organic amines and ammonia, and particularly preferred are ethylamine, trimethylamine, triethylamine and ammonia. The compound containing a hydrophilic anionic group-forming group and an active hydrogen group and the basic neutralizer may be used alone or in combination of two or more.

Examples of the compound containing a hydrophilic cationic group-forming group and an active hydrogen group include N, N-dimethylethanolamine, N, N-diethylethanolamine,
N-dipropylethanolamine, N, N-diphenylethanolamine, N-methyl-N-ethylethanolamine, N-methyl-N-phenylethanolamine,
N, N-dimethylpropanolamine, N-methyl-N
-Ethylpropanolamine, N-methyldiethanolamine, N-ethyldiethanolamine, N-methyldipropanolamine, N-phenyldiethanolamine, N-phenyldipropanolamine, N-hydroxyethyl-N-hydroxypropyl-methylamine,
N, N'-dihydroxyethylpiperazine, triethanolamine, trisisopropanolamine, N-methyl-bis (3-aminopropyl) amine, N-methyl-
Bis (2-aminopropyl) amine and the like can be mentioned. Further, ammonia and primary amines such as methylamine and secondary amines such as dimethylamine with alkylene oxide added thereto can also be used. Examples of the acidic neutralizing agent for forming a hydrophilic cationic group include, for example, hydrochloric acid,
Inorganic and organic acids such as acetic acid, propionic acid, lactic acid, cyanoacetic acid, phosphoric acid and sulfuric acid. Examples of the quaternizing agent include dimethyl sulfate, benzyl chloride, bromoacetamide, chloroacetamide, and alkyl halides such as ethyl bromide, propyl bromide, and butyl bromide. Examples of other compounds containing a hydrophilic cationic group and an active hydrogen group include cationic compounds such as primary amine salts, secondary amine salts, tertiary amine salts, and pyridinium salts. In addition, these compounds containing a hydrophilic cationic group-forming group and an active hydrogen group and an acidic neutralizing agent may be used alone or in combination of two or more.

Examples of the compound containing a hydrophilic amphoteric group and an active hydrogen group include a compound containing an amphoteric group such as a sulfobetaine group formed by a reaction between a tertiary amino group-containing polyol and sultone. .

The amount of the hydrophilic polar group introduced into the self-emulsifying copolymer of the present invention is as follows. In the case where a hydrophilic nonionic group is introduced, the content of the hydrophilic nonionic group (preferably, ethylene oxide unit) is 0.1 to 40% by weight, particularly 0.1% by weight, based on the entire self-emulsifiable copolymer. 5-30 wt% is preferable. When the content of the nonionic hydrophilic polar group is out of this range, the heat resistance and water resistance of the printed film are likely to deteriorate. In the case of introducing a hydrophilic anionic group, a hydrophilic cationic group or a hydrophilic amphoteric group,
0.1 to 1.2 mmol based on the entire self-emulsifying copolymer
1 / g, particularly preferably 0.3 to 1.0 mmol / g.
If the ionic hydrophilic polar group content is outside this range,
The adhesion to the substrate and the stability of the aqueous printing ink are likely to deteriorate.

The hydrophilic polar group preferred in the present invention is a hydrophilic anionic group in consideration of the water resistance of the print film, and more preferably a weak acid having 3 ≦ pKa <7 and a weak acid having 7 <pKa.
A hydrophilic anionic group composed of a weak base having Ka ≦ 12 (provided that pKa = −log ₁₀ Ka and Ka is 25 ° C.)
Is the acidity constant in a dilute aqueous solution of ), Particularly preferably a hydrophilic anionic group which is carboxylic acid-ammonia or carboxylic acid-organic tertiary amine. The reason is as follows. That is, the hydrophilic anionic group is composed of an acid directly bonded to the resin and a free (free) base neutralizer. In the weak anionic group of the weak acid and the weak base, the affinity between the acid and the base is weak and the molecular weight of the neutralizing agent is small, so that the neutralizing agent is easily scattered at the time of forming a print film. As a result, the hydrophilicity of the resin in which the neutralizing agent has scattered is lower than before the scattering. As a result, it is considered that the water resistance of the print film is improved. From the above, in the present invention, it is preferable to use a carboxylic acid group-containing polyol, and more specifically, it is preferable to use dimethylolpropionic acid and / or dimethylolbutanoic acid.

The number average molecular weight of the self-emulsifying copolymer in the present invention is preferably from 5,000 to 100,000,
10,000 to 80,000 is more preferred. When the number average molecular weight is less than 5,000, the film strength becomes insufficient. If it exceeds 100,000, the workability in the production of an aqueous emulsion becomes poor. The number average molecular weight in the present invention is a value measured by gel permeation chromatography using a refractive index detector in terms of polystyrene. The average particle size of the copolymer in the present invention is preferably from 1 to 1,000 nm, particularly preferably from 3 to 900 nm. In the present invention, the average particle size is a value obtained by analyzing a value measured by a dynamic light scattering method by a cumulant method.

The self-emulsifying copolymer in the present invention includes:
Preferably, a keto or aldehyde group is present. This is because the addition of a polyfunctional hydrazide compound to a water-based emulsion of a self-emulsifiable copolymer makes it possible to impart one-part room-temperature curability.

Examples of the one used for introducing a keto group into the acrylic segment include the aforementioned ethylenically unsaturated monomers containing a keto group. Examples of those used to introduce a keto group into the urethane segment include hydroxymethyl ethyl ketone, hydroxyethyl methyl ketone, bis (hydroxymethyl) ketone, hydroxymethyl-2-hydroxyethyl ketone, bis (2
-Hydroxyethyl) ketone, aminomethylethylketone, bis (aminomethyl) ketone, aminomethyl-2-
Aminoethylketone, bis (2-aminoethyl) ketone and the like can be mentioned.

In the present invention, it is preferable to introduce a keto group or an aldehyde group into at least the acrylic segment.
Considering the availability of raw materials, it is more preferable to introduce a keto group or an aldehyde group only in the acrylic segment. Further, in consideration of the toxicity of the raw material of the obtained resin, a compound into which a keto group is introduced is preferable.

Further, the aqueous printing ink of the present invention uses an aqueous emulsion comprising a self-emulsifying copolymer having a keto group or an aldehyde group and a polyfunctional hydrazide compound. As described above, this water-based emulsion has one-part curability at room temperature as described above. Therefore, when applied to a water-based printing ink, there is no factor that causes a measurement error of the base agent-curing agent as in the two-part type, and also, when printing, Since heat energy is not required except for scattering water, productivity is excellent.

The polyfunctional hydrazide compound in the present invention is a compound having two or more hydrazide groups in one molecule, and specifically, 4,4'-bisbenzenedihydrazide, 2,6-pyridinedihydrazide , 1,4-cyclohexanedihydrazide, dihydrazide compounds such as N, N'-hexamethylenebissemicarbazide, oxalic acid dihydrazide, malonic acid dihydrazide, succinic acid dihydrazide, glutaric acid dihydrazide, adipic acid dihydrazide, pimelic acid dihydrazide, suberic acid dihydrazide, Azelaic dihydrazide, sebacic dihydrazide, dodecane dicarboxylic dihydrazide, hexadecane dicarboxylic dihydrazide, maleic dihydrazide,
Dihydrazide such as fumaric acid dihydrazide, itaconic acid dihydrazide, terephthalic acid dihydrazide, isophthalic acid dihydrazide, phthalic acid dihydrazide, 2,6-naphthoic acid dihydrazide, 1,4-naphthoic acid dihydrazide, tartaric acid dihydrazide, malic acid dihydrazide, iminodiacetic acid, etc. Trihydrazides such as dihydrazides, citric acid trihydrazide, 1,2,4-benzenetricarboxylic acid trihydrazide, nitrilotriacetic acid trihydrazide, cyclohexanetricarboxylic acid trihydrazide and trimellitic acid trihydrazide; ethylenediaminetetraacetic acid tetrahydrazide; 1,4,5
Tetracarboxylic acid tetrahydrazides such as 8-naphthoic acid tetrahydrazide and pyromellitic acid tetrahydrazide; carbonic dihydrazides represented by the formula 5; carbohydrazide; thiocarbodihydrazide; bissemicarbazides represented by the formula 6; Acid hydrazide-based polymers having a group represented by the formula:

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[0055]

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[0056]

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Preferred among these polyfunctional hydrazide compounds are those having a solubility in water at 25 ° C. of 3% or more, and particularly preferred are carbohydrazide, malonic dihydrazide, succinic dihydrazide, glutaric dihydrazide, Adipic acid dihydrazide, tartaric acid dihydrazide, malic acid dihydrazide, and citric acid trihydrazide.

The amount of the polyfunctional hydrazide compound to be added is 0.1 to the keto group or aldehyde group of the self-emulsifying copolymer.
1-2 equivalents, especially 0.3-1.5 equivalents, are preferred. When the addition amount of the polyfunctional hydrazide compound is less than 0.1 equivalent, the crosslink density is too low, and the printed film strength becomes insufficient. On the other hand, when the amount exceeds 2 equivalents, the amount of the free hydrazide compound becomes large, so that the appearance of the printed film tends to be adversely affected.

Next, a method for producing the water-based emulsion of the self-emulsifying copolymer used in the present invention will be described. The method for producing an aqueous emulsion of a self-emulsifying copolymer of the present invention comprises a combination of the following three steps. First step (urethane-forming step): a step of reacting an isocyanate group with an active hydrogen group. Second step (radical copolymerization step): a step of radically polymerizing an ethylenically unsaturated double bond using a mercapto group as a chain transfer agent. Third step (emulsification step): a step of emulsifying the obtained copolymer in water.

The first step is a step for obtaining a urethane prepolymer containing a mercapto group. In the first step, for example, the above-mentioned organic polyisocyanate, a compound containing a mercapto group and an active hydrogen group and / or a compound containing a hydrophilic polar group and an active hydrogen group (including a mercapto group) are optionally activated. This is a step of sequentially (a) or simultaneously (b) reacting a compound containing a hydrogen group.
At this time, the final equivalent ratio of all isocyanate groups to all active hydrogen groups is determined by the factors such as the target number average molecular weight, the average number of functional groups of the organic polyisocyanate and the average number of functional groups of the active hydrogen group-containing compound. A condition is calculated that does not satisfy the condition. The compounding ratio is described in J. P. According to the gelation theory theoretically calculated by Flory, Khun et al., In practice, the reaction is carried out at a compounding ratio taking into account the reactivity ratio of the reactive groups contained in the above components, thereby producing without gelation. it can.

(A) When reacting sequentially, for example,
An organic polyisocyanate, a compound containing a mercapto group and an active hydrogen group and / or a compound containing a hydrophilic polar group and an active hydrogen group (including a mercapto group) and, if desired, a compound containing an active hydrogen group in an isocyanate group excess Then, a compound containing a mercapto group and an active hydrogen group is reacted under an excess of active hydrogen groups including a mercapto group, for example, by a method of reacting a mercapto group-containing urethane prepolymer or a mercapto group and a hydrophilic compound. A urethane prepolymer containing a polar group is obtained. (B) When reacting simultaneously, for example, an organic polyisocyanate, a compound containing a mercapto group and an active hydrogen group and / or a compound containing a hydrophilic polar group and an active hydrogen group (including a mercapto group), and if desired, By a method such as reacting a compound containing an active hydrogen group with an excess of active hydrogen groups including a mercapto group, a urethane prepolymer containing a mercapto group or a urethane prepolymer containing a mercapto group and a hydrophilic polar group can be obtained. In each case, the isocyanate group reacts preferentially with a hydroxyl group, an amino group, an imino group, etc., which are more reactive than the mercapto group, and finally, a mercapto group-containing urethane prepolymer or a mercapto group having no isocyanate group. And a hydrophilic polar group-containing urethane prepolymer. The method of (b) simultaneously reacting is preferable because the number of manufacturing steps is reduced.

The urethanization reaction may be carried out in a molten state, a bulk state, or, if necessary, a solvent commonly used in the polyurethane industry, for example, an aromatic hydrocarbon solvent such as toluene, xylene or ethylbenzene, or an ester such as methyl acetate or ethyl acetate. Solvents, ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; glycol ether ester solvents such as ethylene glycol monomethyl ether acetate and propylene glycol monoethyl ether acetate; ether solvents such as tetrahydrofuran and dioxane; methanol and ethanol , Alcoholic solvents such as isopropanol, dimethylformamide, dimethylacetamide, N
One or more polar solvents such as -methylpyrrolidone can be used in combination. Further, at the time of the urethanization reaction, a urethanization catalyst can be used if necessary. Specific examples include organic metal compounds such as dibutyltin dilaurate and dioctyltin dilaurate; organic amines such as triethylenediamine and triethylamine; and salts thereof. The reaction temperature at this time is 30 to
120 ° C, more preferably 50 to 100 ° C. The reaction apparatus is not particularly limited as long as the reaction can be performed uniformly, and for example, a reaction vessel equipped with a stirrer, a kneader,
A mixing and kneading apparatus such as a single-screw or multi-screw extrusion reactor can be used. Considering the second step and the third step, the reaction apparatus is preferably a reaction vessel equipped with a stirrer.

The raw material in the second step is, for example, (1)
A mercapto group-containing urethane prepolymer or a mercapto group and a hydrophilic polar group-containing urethane prepolymer obtained in the first step, an ethylenically unsaturated monomer, a radical polymerization initiator, or (2) an organic polyisocyanate, a mercapto group and active hydrogen A group-containing compound and / or a compound having a hydrophilic polar group and an active hydrogen group (including a mercapto group), and optionally (other) compounds having an active hydrogen group, an ethylenically unsaturated monomer, and a radical polymerization initiator. That is, the method (1) is a method in which the second step proceeds after the first step, and the method (2) is a method in which the first step and the second step are simultaneously performed. In the second step,
It is preferable to use the above-mentioned organic solvent because of easy removal of reaction heat and easy stirring. In the present invention, the method (1) is preferred.

The method of charging each raw material in the second step is not particularly limited, and all raw materials may be charged at once or may be divided and charged. Further, they may be charged in batches or may be charged continuously. A preferred charging method is a method in which the reaction system is charged later by at least dropping a radical polymerization initiator.

In the method (1), a urethane prepolymer containing a mercapto group or a urethane prepolymer containing a mercapto group and a hydrophilic polar group is first obtained. The number average molecular weight of this urethane prepolymer is 1,000 to
Preferably it is 50,000, especially 3,000 to 40,000. When the number average molecular weight is too small, the urethanization reaction is insufficient, so that the resin tends to lack flexibility. When the number average molecular weight exceeds 50,000, the viscosity is too high, so that the second and third steps are likely to be difficult.

The content of the mercapto group before the radical copolymerization is 0.01 to 1.0 mmol in terms of solid content.
/ G, particularly preferably 0.03 to 0.5 mmol / g. Mercapto group content is 0.01 mmol / g
If it is less than 30, the desired self-emulsifying copolymer is difficult to obtain. The mercapto group content is 1.0 mmol / g
If it exceeds, chain transfer occurs more than necessary, and the molecular weight of the copolymer becomes difficult to elongate. The use of a compound containing an active hydrogen group and an ethylenically unsaturated double bond in the reaction system is preferable because the molecular weight of the obtained self-emulsifiable copolymer can be easily controlled. The amount of the compound introduced is preferably 80 mol% or less, more preferably 5 to 75 mol%, and more preferably 10 to 70 mol%, based on the mercapto group.
Is most preferred.

The amount of the polymerization initiator to be charged in the radical copolymerization is from 0.1 to 0.1 mol of the total number of double bonds existing before the reaction.
10 mol%, especially 0.5 to 8 mol% is preferred. When the charged amount of the radical polymerization initiator is too small, the copolymerization hardly proceeds, and the desired copolymer is hardly obtained. If the amount of the radical polymerization initiator charged is too large, the molecular weight of the obtained copolymer is too small, and the strength and durability tend to be insufficient.

The reaction temperature during the radical copolymerization is from 30 to 1
20 ° C, especially 50-100 ° C, is preferred.

The total weight of the ethylenically unsaturated monomers,
The ratio of the urethane raw material to the charged weight is 5/95 to 95.
/ 5, particularly preferably 10/90 to 90/10. When the amount of the ethylenically unsaturated monomer is larger than this ratio, the adhesion of the water-based ink to the polar substrate tends to decrease.
If the amount is small, the re-solubility of the water-based ink tends to deteriorate.

When the first step and the second step are completed, the third step
Proceed to process. The emulsification method is not particularly limited, and is performed by a conventionally known method. When an acid or a tertiary amine is present in the system, it is preferable that the above-described neutralizing agent or quaternizing agent is charged before or simultaneously with water. After the emulsification with water, if an organic solvent is present in the system, it is preferable to remove the solvent. The content of the residual solvent in the aqueous emulsion of the present invention is preferably less than 5%. The removed organic solvent can be recovered and used in the second step.

The water-based printing ink of the present invention may contain, if necessary, other resin-based materials such as pigments, dyes, polyurethanes, acrylic resins, polyesters, polyolefins, polyamides and rubbers in the above-mentioned water-based emulsion of the self-emulsifying copolymer. Emulsions, suspensions, dispersions, aqueous solutions, water for solids and viscosity control, organic solvents such as isopropanol and N-methylpyrrolidone for surface tension control, preservatives, fungicides, antibacterials, anti-blocking Agents, dispersion stabilizers, thixotropic agents, antioxidants, ultraviolet absorbers, defoamers, thickeners, film-forming aids, surfactants, catalysts, lubricants, antistatic agents, plasticizers, leveling agents, gels It is obtained by blending an antioxidant, a light stabilizer and the like and using a ball mill, a sand grind mill and the like.

In an aqueous printing ink in which a keto group or an aldehyde group is present in the self-emulsifying type copolymer and a polyfunctional hydrazide compound is blended in the aqueous emulsion, water is scattered after printing, so that the ink is cured at room temperature. Form a print film that can withstand practical use. In other cases, an aqueous (block) polyisocyanate-based curing agent is added just before printing,
By giving the printed film a crosslinked structure, a film that can withstand practical use is formed. In this case, heating may be performed to promote the reaction between the (generated) isocyanate group and the active hydrogen group. Specific examples of the curing agent include Aquanate 100 and 200 manufactured by Nippon Polyurethane Industry. When using an aqueous (block) polyisocyanate-based curing agent, the blending amount of the aqueous (block) polyisocyanate is as follows:
(Generated) isocyanate group / active hydrogen group = 10/1
量 1/10 (molar ratio).

[0073]

Since the aqueous printing ink of the present invention uses an aqueous emulsion of a self-emulsifying copolymer, it does not cause phase separation and has good long-term stability over time. In addition, it can be printed on any substrate, and has good adhesion, pigment dispersibility, re-dissolvability and the like.

[0074]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the invention is limited thereto. Unless otherwise specified, “parts” and “%” in Examples and Comparative Examples mean “parts by weight” and “% by weight”, respectively.

[Synthesis of Water-Based Emulsion of Self-Emulsifying Copolymer] Example 1 400 parts of polyol A, 14.9 parts of DMBA were placed in a reactor equipped with a stirrer, a thermometer, a nitrogen sealed tube, and a cooler.
9.1 parts of HEMA, 10.1 parts of MHE, 5 parts of MEK
Six parts were charged and dissolved at 50 ° C. Then, after charging 67.3 parts of HDI and 0.05 parts of DBTDL, 75 parts were added.
The reaction was carried out at 0 ° C until the peak of the isocyanate group disappeared by infrared absorption analysis. After that, 195 copies of MEK, I
251 parts of PA were charged, and a urethane prepolymer solution containing a mercapto group and a hydrophilic polar group having a solid content of 50.0% PA
-1 was obtained. The number average molecular weight of this PA-1 was 5,000
0, no keto group was contained, the mercapto group content was 0.26 mmol / g and the carboxylic acid content was 0.20 mmol / g in terms of solid content. In a dropping tank of a reactor (tank) equipped with a stirrer, a thermometer, a nitrogen seal tube, a cooler, and a dropping tank, 30.0 parts of PA-1 and 15.0 parts of MMA.
Parts, BA 11.6 parts, St 3.8 parts, AA 2.2
Parts, DAAA 2.5 parts, AIBN 1.0 parts, MEK
And 25 parts of IPA were charged and uniformly mixed. On the other hand, 30.0 parts of PA-1 and 1 part of MMA were added to the reactor.
5.0 parts, BA 11.5 parts, St 3.7 parts, AA 2.2 parts, DAAA 2.5 parts, MEK 10 parts, IP
A was charged in 10 parts and mixed uniformly. Next, the reaction tank was heated to 75 ° C., and the mixture in the dropping tank was dropped over 5 hours. Thereafter, the reaction was further performed at the same temperature for 4 hours. Thereafter, 6.8 parts of TEA was charged and neutralized sufficiently, and then hydrazide water consisting of 228 parts of distilled water and 2.6 parts of ADH was charged and emulsified. Then, 60 ° C x 13.3 kP
In a, MEK and IPA present in the system were removed to obtain a self-emulsifiable acryl-urethane copolymer aqueous emulsion EA-1 having a solid content of 30.1%. EA-1
Has a viscosity of 300 mPa · s (25 ° C.), a number average molecular weight of the acrylic-urethane copolymer is 25,000, an average particle size is 75 nm, and a keto group content is 0.29 mm in terms of solid content.
ol / g, carboxylate content is 0.67 mmol / g
Met.

Examples 2 to 5, 8 and Comparative Examples 1 to 5 The self-emulsifying acrylic-urethane copolymer was prepared in the same manner as in Example 1 except that the raw materials and the charging ratios shown in Tables 1 and 2 were used, and the reaction temperature and the like were the same as in Example 1. The water-based emulsions EA-2 to EA-5 and EA-8 were prepared in the same manner as in Example 1 at the starting materials and charging ratios shown in Tables 3 and 4, and the reaction temperature and the like were the same as in Example 1. And water-based emulsions EB-2 to EB-5 of a self-emulsifiable urethane resin. In addition, EB-1 was not obtained by gelling at the time of radical polymerization. Example 2
5, 8 and the raw materials charged in the dropping tank and the reaction tank during charging in Comparative Examples 1 to 5 are shown below. Example 2, Comparative Example 1: Dropping tank → Urethane prepolymer, ethylenically unsaturated monomer, radical polymerization initiator, solvent Reaction tank → Urethane prepolymer, ethylenically unsaturated monomer, solvent Examples 3, 4: Dropping tank → Ethylenically unsaturated monomer, radical polymerization initiator, solvent reaction tank → urethane prepolymer Examples 5, 8: dripping tank → radical polymerization initiator, solvent reaction tank → urethane prepolymer, ethylenically unsaturated monomer Comparative Example 2: dropping Tank → ethylenically unsaturated monomer, radical polymerization initiator, solvent Reaction tank → urethane prepolymer, ethylenically unsaturated monomer, solvent Comparative Example 3 Dropping tank → radical polymerization initiator, solvent Reaction tank → ethylenically unsaturated monomer, solvent Comparative Examples 4 and 5 Dropping tank → None Reaction tank → Urethane prepolymer

Example 6 In a reactor equipped with a stirrer, a thermometer, a nitrogen seal tube, and a condenser, 400 parts of polyol E, 13.4 parts of DMPA,
MEK (212 parts) was charged and dissolved at 50 ° C. Next, 88.9 parts of IPDI and 0.15 part of DBTDL were charged and reacted at 75 ° C. for 4 hours. Then ME
15.4 parts of A, 42 parts of MEK, and 254 parts of IPA were charged. Thereafter, 10.1 parts of TEA was charged, and the solid content was 4%.
A 9.8% urethane prepolymer solution PA-5 containing a mercapto group and a hydrophilic polar group was obtained. PA-5 had a number average molecular weight of 5,000, no keto group, a mercapto group content of 0.39 mmol / g and a carboxylate content of 0.19 mmol / g in terms of solids. 6.5 parts of MMA, 15.0 parts of BA, 2.5 parts of AA, and 2.5 parts of EHA were placed in a dropping tank of a reactor (tank) equipped with a stirrer, a thermometer, a nitrogen seal tube, a cooler, and a dropping tank. 1.0 parts, AN
10.0 parts, HEMA 5.0 parts, DAAA 5.0
Parts, AIBN 1.0 parts, MEK 25 parts, IPA 2
Five parts were charged and mixed uniformly. On the other hand, PA
−5 20.0 parts, MMA 6.5 parts, BA 15.0
Parts, 2.5 parts of AA, 1.0 part of EHA, and 10 parts of AN.
0 parts, HEMA 5.0 parts, DAAA 5.0 parts, ME
20 parts of K and 20 parts of IPA were charged and uniformly mixed.
Next, the reaction tank was heated to 75 ° C., and the mixture in the dropping tank was dropped over 5 hours. Thereafter, the reaction was further performed at the same temperature for 4 hours. Thereafter, 6.4 parts of DMEA was charged and neutralized sufficiently, and then hydrazide water consisting of 235 parts of distilled water and 4.7 parts of GDH was charged and emulsified. Then 6
MEK existing in the system at 0 ° C x 13.3 kPa
And a water-based emulsion EA- of a self-emulsifiable acryl-urethane copolymer having a solid content of 29.9% by removing IPA and IPA.
6 was obtained. The viscosity of EA-6 is 100 mPa · s (25
C), the number average molecular weight of the acrylic-urethane copolymer is 3
000, the average particle diameter was 110 nm, and the keto group content was 0.59 mmol / g and the carboxylate content was 0.71 mmol / g in terms of solid content.

Example 7 13.0 parts of MMA was added to a dropping tank of a reactor (tank) equipped with a stirrer, a thermometer, a nitrogen seal tube, a cooler, and a dropping tank.
7.0 parts BA, 2.5 parts AA, 2.5 parts DAAA
Parts, AIBN 1.0 parts, MEK 25 parts, IPA 2
Five parts were charged and mixed uniformly. On the other hand, in the reaction tank, 37.3 parts of polyol F, 1.4 parts of DMBA, 1.0 part of MHE, 1.7 parts of HMK, 0.8 parts of HEMA,
13.0 parts of MA, 7.0 parts of BA, 2.5 parts of AA,
2.5 parts of DAAA, 25 parts of MEK and 25 parts of IPA were charged and dissolved at 50 ° C. Then, HDI was added to 7.
After charging 8 parts, the mixture was heated to 75 ° C., the mixed solution in the dropping tank was dropped over 5 hours, and the urethanization reaction and the radical copolymerization reaction were simultaneously performed at the same temperature over 3 hours. After confirming the absence of isocyanate groups by infrared absorption analysis, 6.6 parts of DMEA was charged. After sufficient neutralization, hydrazide water consisting of 235 parts of distilled water and 3.0 parts of ADH was charged and emulsified. Thereafter, 60 ° C. × 13.
At 3 kPa, MEK and IPA present in the system were removed to obtain a self-emulsifiable acryl-urethane copolymer aqueous emulsion EA-7 having a solid content of 30.2%. E
The viscosity of A-7 is 700 mPa · s (25 ° C.), the number average molecular weight of the acryl-urethane copolymer is 27,000, the average particle size is 40 nm, and the keto group content is 0.1 in terms of solid content.
34 mmol / g, carboxylate content 0.74 mm
ol / g.

Tables 1 to 4 show the synthesis results of Examples 1 to 8 and Comparative Examples 1 to 5. In Example 7 of Tables 1 and 2, a urethane prepolymer was not produced, but the amount of the urethane component charged and the like are shown in parentheses for convenience. Comparative Example 1
The compound was gelled by radical copolymerization of a urethane prepolymer and an ethylenically unsaturated monomer, and the subsequent steps were omitted. When the number average molecular weight of EB-2 of Comparative Example 2 was measured, two molecular weight distributions were measured.
The number average molecular weight of each distribution is described. This is presumably because the urethane prepolymer hardly undergoes chain transfer because there is no mercapto group in the reaction system, and therefore, it is close to a so-called blend state of an acrylic resin and a polyurethane resin. Comparative Example 3 produced a self-emulsifying acrylic emulsion. Comparative Examples 4 and 5 produced self-emulsifying urethane emulsions. In Table 3, for convenience, it is described as a urethane prepolymer solution.

[0080]

[Table 1]

[0081]

[Table 2]

[0082]

[Table 3]

[0083]

[Table 4]

In Tables 1 to 4, polyol A: polycaprolactone diol using ethylene glycol as an initiator (number average molecular weight: 2,000) Polyol B: mixed glycol of ethylene glycol / neopentyl glycol = 8/2 (molar ratio) And adipic acid / isophthalic acid = 5/5 (molar ratio) Polyester diol obtained from mixed dicarboxylic acid (number average molecular weight 2,000) Polyol C: Dimer acid diol obtained from dimer acid and 1,6-hexanediol (Number average molecular weight 2,
000) Polyol D: Polyester diol obtained from 3-methyl-1,5-pentanediol and adipic acid (number average molecular weight: 2,000) Polyol E: 1,6-hexanediol / neopentyl glycol = 8/2 (mol) Polyester diol (number-average molecular weight: 2,000) obtained from mixed glycol and adipic acid (ratio) Polyol F: polycarbonate diol (number-average molecular weight: 2,000) obtained from 1,6-hexanediol and diethyl carbonate / ethylene glycol Polycaprolactone diol (number average molecular weight 2,
000) = 8/2 (weight ratio) transesterified product (number average molecular weight 2,000) DMBA: dimethylolbutanoic acid DMPA: dimethylolpropionic acid MHE: 2-mercapto-1-hydroxyethane TGL: thioglycerol MEA: β-mercaptoethylamine HMK: bis (hydroxymethyl) ketone HEMA: 2-hydroxyethyl methacrylate EtOH: ethanol HDI: hexamethylene diisocyanate H ₆ -XDI: hydrogenated xylylene diisocyanate H ₁₂ -MDI: hydrogenated diphenylmethane diisocyanate IPDI: isophorone diisocyanate DBTDL: dibutyltin dilaurate TEA: triethylamine DMEA: N, N-dimethylethylamine MEK: methyl ethyl ketone IPA: Sopropanol MMA: methyl methacrylate BA: n-butyl acrylate AA: acrylate EHA: 2-ethylhexyl acrylate AN: acrylonitrile St: styrene CHMA: cyclohexyl methacrylate DAAA: diacetone acrylamide AIBN: 2,2'-azobisisobuty Ronitrile BPO: benzoyl peroxide ADH: adipic dihydrazide GDH: glutaric dihydrazide

[Evaluation of Printing Ink] Example 9 EA-1, a pigment, and a solvent were mixed in a sturdy container at the following ratio, and the same amount of glass beads (diameter 1 to 1)
1.5 mm) and dispersed in a paint shaker for 3 hours to form an ink to obtain an aqueous ink. The pigment dispersibility, resolubility, adhesion, and alcohol resistance of this aqueous ink were evaluated. Table 5 shows the results. Ink formulation EA-1 (solid content conversion) 18.0 parts Phthalocyanine blue 12.0 parts Water 65.0 parts IPA 5.0 parts

(1) Pigment dispersibility Using a crush gauge (25 μm), pour the prepared water-based ink into the groove of the crush gauge, and take about 1 second with a scraper to make the crushed and dense portions start to appear. Was read to evaluate the pigment dispersibility. In addition, the judgment of “the place where the dense crush began to appear” is based on JIS K-5400.
(1990). (2) Resolubility Water-based ink was applied to a tin plate with a bar coater No. 4, and after 1, 2, 3, and 5 minutes from the application, a cleaning liquid was applied to the ink-coated surface, and the re-solubility of the water-based ink was evaluated. Evaluation A: The ink dissolves even after 5 minutes from application. (Runs down) ○: The ink does not dissolve 5 minutes after application, but dissolves after 3 minutes. Δ: The ink does not dissolve 3 minutes after application, but dissolves after 2 minutes. ×: The ink does not dissolve 1 minute after the application. (3) Adhesion A water-based ink was applied to a tin plate with a bar coater No. 4 is applied to the discharge-treated surface of a 15 μm-thick corona discharge-treated stretched polypropylene film, 15 μm-thick corona discharge-treated polyethylene terephthalate film, and 15 μm-thick corona discharge-treated nylon film Then, after being left for one day, a cellophane tape was stuck on the printing surface, and this was rapidly peeled off. Evaluation A: 90% or more of the printed film remained. Good: 70% or more and less than 90% of the printed film remained. Fair: 50% or more and less than 70% of the printed film remained. D: Less than 50% of the printed film remained. (4) Alcohol Resistance A 15-μm-thick corona discharge-treated polyethylene terephthalate film was coated with a water-based ink on the discharge-treated surface with a bar coater No. 4 and left for 1 day, rubbed with absorbent cotton impregnated with ethanol, and evaluated by the number of strokes until the base film was exposed.

Examples 10 to 16 and Comparative Examples 6 to 9 EA-1 in Example 9 was replaced with EA-2 to 8 and EB-2 to EA-2.
A water-based ink was prepared in the same manner as in Example 9 except that the ink was replaced with 5, and evaluated similarly. Table 5 shows the results.

[0088]

[Table 5]

In Table 5, OPP: Corona discharge treated stretched polypropylene film PET: Corona discharge treated polyethylene terephthalate film NY: Corona discharge treated nylon film

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Kazuya Sugimoto 4-1-10-506 Sakurada, Washinomiya-cho, Kita-Katsushika-gun, Saitama Prefecture Examiner Chiyako Inoue (56) References JP-A-9-25324 (JP, A) JP-A-11-269247 (JP, A) JP-A-9-111172 (JP, A) JP-A-7-188353 (JP, A) JP-A-7-179801 (JP, A) JP-A-4-270719 ( JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C09D 11/00-13/00 C08L 75/00-75/16 C08F 283/00-283/14 C08G 18/00-18 / 87

Claims (8)

(57) [Claims] 1. A water-based emulsion containing, as a resin component, a self-emulsifiable copolymer in which a hydrophilic polar group-containing ethylenically unsaturated monomer and a mercapto group-containing urethane prepolymer are bonded by radical polymerization. Water-based printing ink. 2. A water-based emulsion containing, as a resin component, a self-emulsifiable copolymer in which an ethylenically unsaturated monomer and a urethane prepolymer containing a mercapto group and a hydrophilic polar group are bonded by radical polymerization. Water-based printing ink. 3. A self-bonded ethylenically unsaturated monomer, an organic polyisocyanate, a compound containing a mercapto group and an active hydrogen group, and a compound containing a hydrophilic polar group and an active hydrogen group by a urethanation reaction and radical polymerization. An aqueous printing ink comprising an aqueous emulsion containing an emulsifying copolymer as a resin component. 4. The aqueous printing ink according to claim 2, wherein the ethylenically unsaturated monomer is an ethylenically unsaturated monomer containing at least a hydrophilic polar group-containing ethylenically unsaturated monomer. 5. The aqueous printing ink according to claim 2, wherein the ethylenically unsaturated monomer is an ethylenically unsaturated monomer containing at least a keto group or aldehyde group-containing ethylenically unsaturated monomer. 6. The urethane prepolymer containing a mercapto group and a hydrophilic polar group, wherein the urethane prepolymer further contains an ethylenically unsaturated double bond in addition to the mercapto group and the hydrophilic polar group. Or the aqueous printing ink according to 5. 7. The urethane prepolymer containing a mercapto group and a hydrophilic polar group, the urethane prepolymer further containing a keto group or an aldehyde group in addition to the mercapto group and the hydrophilic polar group, or a mercapto group and a hydrophilic polar group 6. The aqueous printing ink according to claim 2, which is a urethane prepolymer further containing a keto group or an aldehyde group in addition to the ethylenically unsaturated double bond. 8. An aqueous printing ink comprising the aqueous printing ink according to claim 5, and a polyfunctional hydrazide compound.