JP2013216809A - Fine resin particle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fine aqueous resin particle dispersion capable of being used for aqueous ink compositions which express water resistance and adhesiveness to an olefin copolymer substrate even when a coating film is formed at low temperature, and has redissolvability where an ink coating film dried on a plate can again be dissolved with an aqueous ink composition; and to provide an aqueous ink composition using the fine aqueous resin particle dispersion.SOLUTION: A fine aqueous resin particle dispersion is obtained by emulsion-polymerizing an ethylenically unsaturated monomer (C) in the presence of an olefin copolymer (excluding acrylic copolymers) (A) and an acrylic copolymer (B) in an aqueous solvent. An aqueous ink composition contains the fine aqueous resin particle dispersion.

Description

  The present invention expresses adhesion to an olefin copolymer substrate and water resistance even when it is formed at a low temperature, and has re-solubility that allows an ink film dried on a plate to be dissolved again by an aqueous ink composition. The present invention relates to an aqueous resin fine particle dispersion that can be used in an aqueous ink composition, and an aqueous ink composition using the aqueous resin fine particle dispersion.

  Today, plastic films such as polyethylene, polypropylene, polyester, and nylon are widely used as various packaging materials, and printing on these plastic films is performed by flexographic or gravure printing. Conventionally, solvent inks using organic solvents such as toluene, ethyl acetate, isopropyl alcohol, etc., have been used exclusively for such applications, but in recent years, consideration has been given to air pollution, fire hazard, occupational hygiene, etc. Accordingly, there is an increasing interest in water-based inks that do not use organic solvents.

  However, in the field of printing on a non-permeable plastic film substrate mainly for soft packaging materials, water-based ink compositions are hardly put into practical use except for some applications. This is because it is difficult to say that the quality of the water-based ink composition is sufficient in this field as compared with the solvent-type printing ink. In other words, the basic properties of the aqueous ink composition are adhesion to the olefin copolymer substrate, water resistance, and re-solubility that allows the ink film dried on the plate to be dissolved again by the aqueous ink composition in a well-balanced manner. However, such an aqueous ink composition has not been put into practical use yet.

  As an attempt to improve the adhesion to a plastic film, Patent Document 1 discloses that an alkaline solution of a styrene acrylic copolymer and an acrylic emulsion in a specific glass transition temperature range are mixed, and a rosin ester is used as a tackifier. An aqueous ink composition is disclosed which, when added in the form of an aqueous dispersion, imparts adhesion to various plastic substrates and suitability for lamination. Patent Document 2 discloses a composition used for water-based ink or the like, comprising a water dispersion containing a rosin component in a polymer made of an aqueous acrylic copolymer or polyurethane. However, with the addition of aqueous dispersions such as rosin, even when the adhesive strength to various film substrates is improved, the wetting of olefin copolymer films subjected to general-purpose corona discharge treatment is completely improved. In addition, there was a drawback that a smooth printed surface could not be obtained.

  In Patent Document 3 and Patent Document 4, a water-soluble resin is used as a main binder for imparting re-solubility, and keto / water is imparted to provide adhesion to a plastic film having an aldo group on the surface and water resistance. A hydrazide bridge is used. However, when a binder resin consisting of a carbonyl group-containing water-soluble acrylic copolymer and a hydrazine derivative is used, the crosslinking reaction proceeds by evaporation of water on the plate where the coating film becomes very thin, and the fluidity and re-solubility. There is a problem that decreases.

  Patent Documents 5 and 6 disclose aqueous resin dispersions obtained by polymerizing a monomer having an α, β-unsaturated double bond using a chlorinated olefin copolymer as an emulsifier. Thus, excellent adhesion to the olefin copolymer substrate has been confirmed. However, since the chlorinated olefin copolymer releases a chlorine compound at the time of combustion, it is not preferable from the viewpoint of environmental protection.

Japanese Patent Laid-Open No. 61-19676 JP-A-3-7783 JP-A-63-101435 JP-A-6-143786 Japanese Patent Application Laid-Open No. 7-118312 JP-A-8-3207

  The present invention provides an aqueous solution having re-solubility that can exhibit adhesion and water resistance to an olefin copolymer substrate even when formed into a film at a low temperature, and that an ink film dried on a plate can be dissolved by an aqueous ink composition. It is an object of the present invention to provide an aqueous resin fine particle dispersion that can be used in an ink composition and an aqueous ink composition using the aqueous resin fine particle dispersion.

  In the first invention, an ethylenically unsaturated monomer (C) is aqueous in the presence of an olefin copolymer (excluding an acrylic copolymer) (A) and an acrylic copolymer (B). The present invention relates to a resin fine particle dispersion obtained by emulsion polymerization in a medium.

  In the second invention, the olefin copolymer (A) has an acid value of 50 to 300 mgKOH / g, the acrylic copolymer (B) has an acid value of 50 to 300 mgKOH / g and a weight average molecular weight of 500 to 30000. The present invention relates to a resin fine particle dispersion of the invention of 1.

  In the third invention, the olefin copolymer (A) comprises a terminal acid-modified olefin copolymer (a1), an acid graft-modified olefin copolymer (a2), and an α-olefin maleic anhydride copolymer ( The resin fine particle dispersion of the first or second invention, which is at least one resin selected from a3).

  The fourth invention is an ethylenically unsaturated monomer (A) in the presence of 1 to 40 parts by weight of the olefin copolymer (A) and 20 to 40 parts by weight of the acrylic copolymer (B). The resin fine particle dispersion according to any one of the first to third inventions, wherein 40 to 70 parts by weight of C) is emulsion-polymerized in an aqueous medium.

  The fifth invention relates to the resin fine particle dispersion according to any one of the first to fourth inventions, wherein the minimum film-forming temperature (MFT) is -40 to 20 ° C.

  The sixth invention relates to an aqueous ink composition comprising a pigment and the resin fine particle dispersion according to any one of the first to fifth inventions.

  The seventh invention relates to the aqueous ink composition of the sixth invention used for flexographic or gravure printing.

  The eighth invention also relates to the water-based ink composition of the seventh invention used for an olefin copolymer substrate.

  By using the resin fine particles of the present invention for flexographic or gravure printing, adhesion to an olefin copolymer substrate and water resistance, resolubility that allows the ink film dried on the plate to be dissolved again by the aqueous ink composition is good. Certain aqueous ink compositions can be provided.

  The present invention relates to an ethylenically unsaturated monomer (C) in an aqueous medium in the presence of an olefin copolymer (excluding an acrylic copolymer) (A) and an acrylic copolymer (B). It is characterized by being formed by emulsion polymerization.

  First, the olefin copolymer (A) will be described.

  The olefin copolymer (A) used in the present invention is selected from a terminal acid-modified olefin copolymer (a1), an acid graft-modified olefin copolymer (a2), and an α-olefin maleic anhydride copolymer (a3). At least one resin is preferred. By using an olefin copolymer containing an acid, the affinity of the highly hydrophobic olefin copolymer for an aqueous medium can be increased. Especially, since the polar group like an acid is not included in the olefin skeleton, the terminal acid-modified olefin copolymer (a1) having a large effect of introducing the olefin skeleton is preferable.

  The terminal acid-modified olefin copolymer (a1) can be obtained by modifying the terminal of the olefin copolymer with an acid. The olefin copolymer can be produced according to a conventional method using, for example, a vanadium catalyst, a magnesium catalyst, a titanium catalyst containing titanium, halogen, or the like as a component. Examples of the olefin copolymer include homopolymers and copolymers of ethylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 3-methyl-1-pentene, 1-hexene and 40-α-olefin. A polymer is mentioned.

A commercial item can also be used for the terminal acid-modified olefin copolymer (a1). Examples of commercially available products include Baker Hughes X-10065, X-10087, X-10044, Baker Petrolite Unicide ^TM 350, and the like.

  The acid graft-modified polyolefin (a2) can be produced, for example, by reacting the olefin copolymer as described above with a graft component in the presence of a peroxide as a radical generator, such as ditertiary butyl peroxide. it can. Unsaturated carboxylic acids and their anhydrides can be used as the graft component, for example, acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, bicyclo [2,1,1] pept-2-ene Unsaturated carboxylic acids such as -5,6-dicarboxylic acid, maleic anhydride, itaconic anhydride, citraconic anhydride, bicyclo [2,1,1] pept-2-ene-5,6-dicarboxylic anhydride and the like Anhydrides are mentioned. These can be used alone or in combination of two or more.

  A commercially available product can also be used as the acid graft-modified polyolefin (a2). Examples of commercially available products include Ceramer 1608 manufactured by Baker Petrolite.

  The α-olefin maleic anhydride copolymer (a3) can be obtained by radical copolymerization of maleic anhydride or maleate with an α-olefin.

  The copolymerization method of the α-olefin and maleic anhydride may be performed without a solvent, or may be performed in combination with a solvent. Maleic anhydride may be charged at a time together with the α-olefin, or may be gradually added to the polymerization system. These polymerization methods are not particularly limited. As the polymerization initiator used in this case, azobis compounds such as azobisisobutyronitrile, azobis 2,4-dimethylvaleronitrile, cumene hydroperoxide, t-butyl hydroperoxide, benzoyl peroxide, diisopropyl peroxycarbonate, Examples thereof include peroxides such as di-t-butyl peroxide, lauroyl peroxide, and t-butyl peroxybenzoate.

  In the α-olefin maleic anhydride copolymer (a3), the α-olefin copolymerized with maleic anhydride is not particularly limited. For example, ethylene, propylene, butylene, isobutylene, pentene, 1-hexene, 1-heptene. 1-octene, 1-nonene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene, 1-docosene, 1-tetraeicocene, 1-hexaicosene, 1 -Octaicosene, 1-triacontene, 1-dotriacontene, 1-tetratriacontene, 1-hexatriatainene, 1-octatriatenene, 1-tetracontane, etc., and mixtures thereof.

  A commercial item can also be used for the α-olefin maleic anhydride copolymer (a3). Commercially available products include, for example, Yoshicol series from Gifu Serax, Diacarna 30 from Mitsubishi Chemical Corporation, and the like.

  By introducing the olefin copolymer skeleton, the hydrophobicity is increased, and the effect of improving adhesion and water resistance to the olefin copolymer substrate is obtained.

  The olefin copolymer (A) preferably has an acid value of 50 to 300 mgKOH / g. More preferably, it is 100-250 mgKOH / g. When the acid value is less than 50 mgKOH / g, it becomes difficult to make the olefin copolymer (A) aqueous, and the polymerization stability of the resin fine particle dispersion also decreases. When the acid value exceeds 300 mgKOH / g, the water resistance of the printed matter is deteriorated and the adhesion of the ink composition to the low polarity substrate is deteriorated. The acid value mentioned here means the number of mg of potassium hydroxide required to neutralize the acidic component contained in 1 g of resin.

  Next, the acrylic copolymer (B) will be described. The acrylic copolymer (B) is a copolymer of a carboxyl group-containing acrylic monomer (b1), another acrylic monomer (b2), and a monomer (b3) copolymerizable with the acrylic monomer. It is.

  Examples of the carboxyl group-containing acrylic monomer (b1) include phthalic acid β- (meth) acryloxyethyl monoester, isophthalic acid β- (meth) acryloxyethyl monoester, terephthalic acid β- (meth) acryloxy. Examples thereof include, but are not limited to, ethyl monoester, succinic acid β- (meth) acryloxyethyl monoester, acrylic acid, methacrylic acid, crotonic acid, and cinnamic acid. These can be used alone or in combination of two or more.

As other acrylic monomer (b2), for example,
Methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, heptyl (meth) acrylate, hexyl (meth) acrylate , 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, undecyl (meth) acrylate, dodecyl (meth) acrylate, tridecyl (meth) acrylate, tetradecyl (meth) acrylate Linear or branched alkyl group-containing acrylic monomers such as
Alicyclic alkyl group-containing ethylenically unsaturated monomers such as cyclohexyl (meth) acrylate and isobornyl (meth) acrylate;
Fluorinated alkyl group-containing acrylic monomers such as trifluoroethyl (meth) acrylate and heptadecafluorodecyl (meth) acrylate;
Aromatic acrylic monomers such as benzyl (meth) acrylate, phenoxyethyl (meth) acrylate, and phenyl (meth) acrylate;
(Meth) acrylamide, N-methoxymethyl- (meth) acrylamide, N-ethoxymethyl- (meth) acrylamide, N-propoxymethyl- (meth) acrylamide, N-butoxymethyl- (meth) acrylamide, N-pentoxymethyl -(Meth) acrylamide, N, N-di (methoxymethyl) acrylamide, N-ethoxymethyl-N-methoxymethylmethacrylamide, N, N-di (ethoxymethyl) acrylamide, N-ethoxymethyl-N-propoxymethylmeta Acrylamide, N, N-di (propoxymethyl) acrylamide, N-butoxymethyl-N- (propoxymethyl) methacrylamide, N, N-di (butoxymethyl) acrylamide, N-butoxymethyl-N- (methoxymethyl) meta Acrylic net N, N-di (pentoxymethyl) acrylamide, N-methoxymethyl-N- (pentoxymethyl) methacrylamide, N, N-dimethylaminopropylacrylamide, N, N-diethylaminopropylacrylamide, N, N-dimethyl Amide group-containing acrylic monomers such as acrylamide, N, N-diethylacrylamide, diacetone (meth) acrylamide;
Hydroxyl group-containing acrylic monomers such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, glycerol mono (meth) acrylate;
Sulfonic acid group-containing acrylic monomers such as 2-acrylamido 2-methylpropanesulfonic acid and sodium 2-acrylamido-2-methylpropanesulfonate;
Allyl (meth) acrylate, 1-methylallyl (meth) acrylate, 2-methylallyl (meth) acrylate, 1-butenyl (meth) acrylate, 2-butenyl (meth) acrylate, 3-butenyl (meth) acrylate, 1,3- Methyl-3-butenyl (meth) acrylate, 2-chloroallyl (meth) acrylate, 3-chloroallyl (meth) acrylate, o-allylphenyl (meth) acrylate, 2- (allyloxy) ethyl (meth) acrylate, allyl lactyl (meth) Acrylate, citronellyl (meth) acrylate, geranyl (meth) acrylate, rosinyl (meth) acrylate, cinnamyl (meth) acrylate, 2- (2′-vinyloxyethoxy) ethyl (meth) acrylate, ethylene glycol di (meth) ) Acrylate, 1,9-nonanediol di (meth) acrylate, triethylene glycol (meth) acrylate, tetraethylene glycol (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, 1, Acrylic having two or more ethylenically unsaturated groups such as 1,1-trishydroxymethylethane diacrylate, 1,1,1-trishydroxymethylethane triacrylate, 1,1,1-trishydroxymethylpropane triacrylate Monomer;
Epoxy group-containing acrylic monomers such as glycidyl (meth) acrylate and 3,4-epoxycyclohexyl (meth) acrylate;
γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltriethoxysilane, γ-methacryloxypropyltributoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ-acryloxy Alkoxysilyl group-containing acrylic monomers such as propyltrimethoxysilane, γ-acryloxypropyltriethoxysilane, γ-acryloxypropylmethyldimethoxysilane, γ-methacryloxymethyltrimethoxysilane, and γ-acryloxymethyltrimethoxysilane ;
Examples include, but are not limited to, methylol group-containing acrylic monomers such as N-methylol (meth) acrylamide, N, N-dimethylol (meth) acrylamide, and alkyletherified N-methylol (meth) acrylamide. Absent. These can be used alone or in combination of two or more.

As the monomer (b3) copolymerizable with the acrylic monomer, for example,
Carboxyl group-containing vinyl monomers such as maleic acid, fumaric acid, itaconic acid, citraconic acid, or alkyl or alkenyl monoesters thereof;
Aromatic vinyl monomers such as styrene, α-methylstyrene, o-methylstyrene, p-methylstyrene, m-methylstyrene, vinylnaphthalene;
Hydroxyl group-containing ethylenically unsaturated monomers such as 4-hydroxyvinylbenzene, 1-ethynyl-1-cyclohexanol, allyl alcohol;
Styrene sulfonic acid, sodium styrene sulfonate, ammonium styrene sulfonate, methallyl sulfonic acid, sodium methallyl sulfonate, allyl sulfonic acid, sodium allyl sulfonate, ammonium allyl sulfonate, vinyl sulfonic acid, allyloxybenzene sulfonic acid, allyl Sulfonic acid group-containing vinyl monomers such as sodium oxybenzene sulfonate and ammonium allyloxybenzene sulfonate;
Divinyl monomers such as diallyl maleate, diallyl itaconic acid, vinyl (meth) acrylate, vinyl crotonic acid, vinyl oleate, vinyl linolenate, divinylbenzene, divinyl adipate, diallyl isophthalate, diallyl phthalate, diallyl maleate ;
Examples thereof include, but are not limited to, alkoxysilyl group-containing vinyl monomers such as vinyltrimethoxysilane, vinyltriethoxysilane, vinyltributoxysilane, and vinylmethyldimethoxysilane. These can be used alone or in combination of two or more.

As a manufacturing method of an acrylic copolymer (B), it mentions about a styrene- (meth) acrylic acid- (meth) acrylic-acid alkylester copolymer, for example. An organic solvent is charged into the reaction vessel and the temperature is raised. Any organic solvent can be used as long as it does not adversely affect the reaction and subsequent treatment and can dissolve the obtained resin. After raising the temperature, radical polymerization is carried out by adding a radical initiator while dropping styrene, (meth) acrylic acid, and alkyl (meth) acrylate in a nitrogen atmosphere. The radical polymerization can be performed by a known polymerization method, and is particularly preferably performed by solution polymerization. The obtained resin solution may be diluted with ion-exchanged water as it is, or the organic solvent may be replaced with ion-exchanged water. When the resin is difficult to dissolve in an aqueous medium such as ion exchange water, the carboxyl group in the resin is neutralized with a basic substance.

  The acrylic copolymer (B) preferably has an acid value of 50 to 300 mgKOH / g. More preferably, it is 100-250 mgKOH / g. When the acid value is less than 50 mgKOH / g, it becomes difficult to make the acrylic copolymer (B) aqueous, and the polymerization stability of the resin fine particle dispersion also decreases. When the acid value exceeds 300 mgKOH / g, the water resistance of the printed matter, the adhesion to a low-polarity substrate, and the temporal stability of the ink composition are deteriorated.

  Moreover, it is preferable that the weight average molecular weights of an acrylic copolymer (B) are 500-30000. When the weight average molecular weight is less than 500, the blocking resistance and water resistance of the printed matter due to the low molecular weight component and the polymerization stability of the resin fine particle dispersion are deteriorated. When the weight average molecular weight exceeds 30000, the stability of the ink composition with time deteriorates, and the adhesion of the printed matter due to the increase in the high molecular weight component also decreases. The weight average molecular weight here refers to a value in terms of polystyrene by GPC (gel permeation chromatography) measurement.

  A commercial item can also be used for an acrylic copolymer (B). As commercially available products, for example, BASF Corp. JONCRYL67, JONCRYL678, JONCRYL586, JONCRYL611, JONCRYL683, JONCRYL690, JONCRYL57J, JONCRYL60J, JONCRYL61J, JONCRYL62J, JONCRYL63J, JONCRYLHPD-96J, JONCRYL501J, JONCRYLPDX-6102B, manufactured by BYK Chemie DISPERBYK, DISPERBYK180, DISPERBYK187 , DISPERBYK190, DISPERBYK191, DISPERBYK194, DISPERBYK2010, DISPERBYK2015, DISPERBYK2090, DISPERBYK2091, DISPERBYK2095 , DISPERBYK2155, SOLSPERS41000 manufactured by Zeneca, SMA1000H, SMA1440H, SMA2000H, SMA3000H, SMA17352H, manufactured by Sartomer. These can be used alone or in combination of two or more.

  Although only the olefin copolymer (A) has insufficient solubility in water and the polymerization becomes unstable, it is possible to ensure excellent polymerization stability by including the acrylic copolymer (B). Become. Furthermore, emulsion polymerization of the ethylenically unsaturated monomer (C) in the presence of the olefin copolymer (A) and the acrylic copolymer (B) having a high affinity for an aqueous medium and good resolubility As a result, a resin fine particle dispersion having a high molecular weight hydrophobic core is formed, and an ink composition having both excellent re-solubility and coating film resistance can be obtained.

  The ethylenically unsaturated monomer (C) used in the present invention is copolymerizable with the carboxyl group-containing acrylic monomer (b1), other acrylic monomers (b2), and acrylic monomers. Although a monomer (b3) etc. are mentioned, it is not necessarily limited to these. These can be used alone or in combination of two or more.

The polymerization initiator used for emulsion polymerization of the ethylenically unsaturated monomer (C) used in the present invention is not particularly limited as long as it has the ability to initiate radical polymerization, and is known oil-soluble. A polymerization initiator and a water-soluble polymerization initiator can be used. The oil-soluble polymerization initiator is not particularly limited, and examples thereof include benzoyl peroxide, tert-butyl peroxybenzoate, tert-butyl hydroperoxide, tert-butyl peroxy (2-ethylhexanoate), and tert-butyl peroxide. Organic peroxides such as oxy-3,5,5-trimethylhexanoate, di-tert-butyl peroxide;
2,2′-azobisisobutyronitrile, 2,2′-azobis-2,4-dimethylvaleronitrile, 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile), 1,1 Mention may be made of azobis compounds such as' -azobis-cyclohexane-1-carbonitrile. These may be used alone or in combination of two or more. These polymerization initiators are preferably used in an amount of 0.1 to 10.0 parts by weight with respect to 100 parts by weight of the ethylenically unsaturated monomer.

  In the present invention, it is preferable to use a water-soluble polymerization initiator. Examples of the water-soluble polymerization initiator include ammonium persulfate, potassium persulfate, hydrogen peroxide, and 2,2′-azobis (2-methylpropionamidine). Conventionally known ones such as dihydrochloride can be preferably used. Moreover, when performing emulsion polymerization, a reducing agent can be used together with a polymerization initiator if desired. Thereby, it becomes easy to accelerate the emulsion polymerization rate or to perform the emulsion polymerization at a low temperature. Examples of such a reducing agent include reducing organic compounds such as metal salts such as ascorbic acid, ersorbic acid, tartaric acid, citric acid, glucose, formaldehyde sulfoxylate, sodium thiosulfate, sodium sulfite, sodium bisulfite, Examples include reducing inorganic compounds such as sodium bisulfite, ferrous chloride, Rongalite, thiourea dioxide, and the like. These reducing agents are preferably used in an amount of 0.05 to 5.0 parts by weight with respect to 100 parts by weight of the total ethylenically unsaturated monomer. In addition, it can superpose | polymerize also by a photochemical reaction, radiation irradiation, etc. irrespective of an above described polymerization initiator. The polymerization temperature is not less than the polymerization start temperature of each polymerization initiator. For example, in the case of a peroxide-based polymerization initiator, it may be usually about 70 ° C. The polymerization time is not particularly limited, but is usually 2 to 24 hours.

  Further, if necessary, sodium acetate, sodium citrate, sodium bicarbonate, etc. as a buffering agent, and octyl mercaptan, 2-ethylhexyl thioglycolate, octyl thioglycolate, stearyl mercaptan, lauryl mercaptan as a chain transfer agent A suitable amount of mercaptans such as t-dodecyl mercaptan can be used.

  In the aqueous resin dispersion of the present invention, other resin components, antioxidants, ultraviolet absorbers, hydrochloric acid absorbents, dehydrochlorination inhibitors, pigments, dyes, if necessary, as long as the effects of the present invention are not impaired. Fillers, blocking agents, antistatic agents, anti-slip agents, tackifier resins, thickeners, antifoaming agents, leveling agents and the like can be used in combination.

  A surfactant may be used in combination for the purpose of improving the stability of the aqueous dispersion or the mechanical stability of the composite dispersion obtained by polymerizing the dispersion.

  In the present invention, as the surfactant used as necessary during the emulsion polymerization, a reactive surfactant having an ethylenically unsaturated group, a non-reactive surfactant having no ethylenically unsaturated group, and the like are conventionally used. A well-known thing can be used arbitrarily.

  Reactive surfactants having an ethylenically unsaturated group can be further broadly classified into anionic and nonionic nonionic ones. In particular, when an anionic reactive surfactant or a nonionic reactive surfactant having an ethylenically unsaturated group is used, the dispersion particle size of the copolymer becomes fine and the particle size distribution becomes narrow. When used as a binder for battery electrodes, it is possible to improve the resistance to electrolytic solution, which is preferable. This anionic reactive surfactant or nonionic reactive surfactant having an ethylenically unsaturated group may be used singly or in combination.

Specific examples of the anionic reactive surfactant having an ethylenically unsaturated group are shown below, but the surfactants that can be used in the present invention are limited to those described below. is not. Examples of the surfactant include alkyl ethers (commercially available products include, for example, Aqualon KH-05, KH-10, KH-20, manufactured by Daiichi Kogyo Seiyaku Co., Ltd., ADEKA rear soap SR-10N, SR manufactured by ADEKA Corporation. -20N, LATEMUL PD-104 manufactured by Kao Corporation), etc .;
Sulfosuccinic acid ester-based (for example, LATEMUL S-120, S-120A, S-180P, S-180A, Sanyo Chemical Co., Ltd., Elemiol JS-2, etc., manufactured by Kao Corporation);
Alkyl phenyl ether type or alkyl phenyl ester type (commercially available products include, for example, Aqualon H-2855A, H-3855B, H-3855C, H-3856, HS-05, HS-10, HS, manufactured by Daiichi Kogyo Seiyaku Co., Ltd. -20, HS-30, Adeka Soap SDX-222, SDX-223, SDX-232, SDX-233, SDX-259, SE-10N, SE-20N, etc. manufactured by ADEKA Corporation);
(Meth) acrylate sulfate-based (commercially available products include, for example, Antox MS-60, MS-2N, Sanyo Chemical Industries Co., Ltd., Elemiol RS-30, manufactured by Nippon Emulsifier Co., Ltd.);
Examples of the phosphoric acid ester (commercially available products include H-3330PL manufactured by Daiichi Kogyo Seiyaku Co., Ltd., Adeka Soap PP-70 manufactured by ADEKA Co., Ltd., etc.)

Nonionic reactive surfactants that can be used in the present invention include, for example, alkyl ethers (commercially available products such as Adeka Soap ER-10, ER-20, ER-30, and ER- manufactured by ADEKA Corporation). 40, Latemu PD-420, PD-430, PD-450, etc. manufactured by Kao Corporation);
Alkyl phenyl ether type or alkyl phenyl ester type (commercially available products include, for example, Aqualon RN-10, RN-20, RN-30, RN-50, manufactured by Daiichi Kogyo Seiyaku Co., Ltd., ADEKA rear soap NE- manufactured by ADEKA Co., Ltd. 10, NE-20, NE-30, NE-40, etc.);
(Meth) acrylate sulfate esters (commercially available products include, for example, RMA-564, RMA-568, and RMA-1114 manufactured by Nippon Emulsifier Co., Ltd.).

  When the resin fine particles of the present invention are obtained by emulsion polymerization, a non-reactive surfactant having no ethylenically unsaturated group may be used in combination with the reactive surfactant having an ethylenically unsaturated group as described above. Can do. Non-reactive surfactants can be broadly classified into non-reactive anionic surfactants, non-reactive cationic surfactants, and non-reactive nonionic surfactants.

Examples of non-reactive nonionic emulsifier surfactants include polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether and polyoxyethylene stearyl ether;
Polyoxyethylene alkylphenyl ethers such as polyoxyethylene octylphenyl ether and polyoxyethylene nonylphenyl ether;
Sorbitan higher fatty acid esters such as sorbitan monolaurate, sorbitan monostearate, sorbitan trioleate;
Polyoxyethylene sorbitan higher fatty acid esters such as polyoxyethylene sorbitan monolaurate;
Polyoxyethylene higher fatty acid esters such as polyoxyethylene monolaurate and polyoxyethylene monostearate;
Glycerin higher fatty acid esters such as oleic acid monoglyceride and stearic acid monoglyceride;
Examples include polyoxyethylene / polyoxypropylene / block copolymer, polyoxyethylene distyrenated phenyl ether, and the like.

Examples of non-reactive anionic emulsifiers include higher fatty acid salts such as sodium oleate;
Alkylaryl sulfonates such as sodium dodecylbenzenesulfonate;
Alkyl sulfate salts such as sodium lauryl sulfate;
Polyoxyethylene alkyl ether sulfate esters such as sodium polyoxyethylene lauryl ether sulfate;
Polyoxyethylene alkylaryl ether sulfate salts such as sodium polyoxyethylene nonylphenyl ether sulfate;
Alkyl sulfosuccinic acid ester salts such as sodium monooctyl sulfosuccinate, sodium dioctyl sulfosuccinate, sodium polyoxyethylene lauryl sulfosuccinate and derivatives thereof;
Examples thereof include polyoxyethylene distyrenated phenyl ether sulfate salts.
Examples of non-reactive cationic surfactants include
For example, alkyltrimethylamine-based quaternary ammonium salts represented by RN (CH ₃ ) ₃ X [R = stearyl, cetyl, lauryl, oleyl, dodecyl, palm, soybean, beef tallow etc./X=halogen, amine, etc.];
Quaternary ammonium salts such as tetramethylamine salts and tetrabutylamine salts;
Acetates represented by (RNH ₃ ) (CH ₃ COO) [R = stearyl, cetyl, lauryl, oleyl, dodecyl, palm, soybean, beef tallow, etc.];
Benzylamine quaternary ammonium salts such as lauryldimethylbenzylammonium salt (halogen / amine salt, etc.), stearyldimethylbenzylammonium salt (halogen / amine salt, etc.), dodecyldimethylbenzylammonium salt (halogen / amine salt, etc.);
_{R (CH 3) N (C} 2 H 4 O) mH (C 2 H 4 O) n · X [R = stearyl cetyl lauryl oleyl dodecyl coconut, soybean beef tallow / X = halogen amine , M, and n are integers of 0 or more], and polyoxyalkylene-based quaternary ammonium salts can be used.

  Then, the manufacturing method of the resin fine particle dispersion of this invention is demonstrated. First, an aqueous medium, an olefin copolymer (A) having an acid value of 50 to 300 mgKOH / g, and an acrylic copolymer (B) having an acid value of 50 to 300 mgKOH / g and a weight average molecular weight of 500 to 30,000 are charged in a reaction vessel. The temperature is raised and neutralized with a basic substance to dissolve. Thereafter, a radical polymerization initiator is added while dropping the ethylenically unsaturated monomer (C) under a nitrogen atmosphere. Since the color of the solution in the reaction vessel turns pale after the reaction starts, the formation of particle nuclei can be confirmed. After completion of the dropwise addition of the ethylenically unsaturated monomer (C), the desired resin fine particle dispersion can be obtained by further reacting for several hours. The olefin copolymer (A) and the acrylic copolymer (B) act as a protective colloid in the aqueous medium and greatly stabilize the particle nuclei to be generated. The resin fine particle dispersion obtained by this method is extremely superior in dispersion stability and difficult to ensure stability compared to a resin fine particle dispersion obtained by general emulsion polymerization using a surfactant. A resin fine particle dispersion having a small average particle diameter can also be easily obtained. By using this resin fine particle dispersion in an aqueous ink composition, the stability over time of the ink is improved. In addition, it is easy to obtain a resin fine particle dispersion having a small average particle diameter, and the film formability is good, so that the gloss and brightness of the printed matter are also excellent.

As the basic substance, an inorganic basic substance and an organic basic substance can be used. Examples of the inorganic basic substance include inorganic basic substances such as sodium hydroxide and potassium hydroxide, but are not necessarily limited thereto.
Examples of organic basic substances include:
Monoamines such as ammonia, triethylamine, trimethylamine, butylamine, dibutylamine;
Polyamines such as ethylenediamine, hexamethylenediamine, piperazine, isophoronediamine, triethylenediamine, diethylenetriamine;
Alkanolamines such as monoethanolamine, diethanolamine, triethanolamine, N-methyldiethanolamine and the like can be mentioned, but the invention is not necessarily limited thereto.

  The resin fine particle dispersion of the present invention comprises an olefin copolymer (A) 1 to 40% by weight, an acrylic copolymer (B) 20 to 40% by weight, and an ethylenically unsaturated monomer (C) 40 to 70%. It preferably consists of% by weight.

  When the olefin copolymer (A) is less than 1% by weight, the effect of the olefin skeleton is not sufficiently exhibited, and the adhesiveness and water resistance of the printed matter may be lowered. On the other hand, if it exceeds 40% by weight, the polymerization stability of the resin fine particle dispersion may be deteriorated, and the blocking resistance may be lowered due to an increase in a relatively low molecular weight component.

  When the acrylic copolymer (B) is less than 20% by weight, the polymerization stability of the resin fine particle dispersion may be lowered and the redissolvability of the ink composition may be deteriorated. On the other hand, if it exceeds 40% by weight, the water resistance of the printed matter may be lowered due to an increase in affinity for an aqueous medium, and the blocking property may be lowered due to an increase in a relatively low molecular weight component.

  When the ethylenically unsaturated monomer (C) is less than 40% by weight, the affinity of the resin fine particle dispersion for the aqueous medium increases, resulting in a decrease in water resistance of the printed matter, and an increase in relatively low molecular components. There is a risk of deterioration of blocking properties. On the other hand, if it exceeds 70% by weight, the polymerization stability of the resin fine particle dispersion may be deteriorated and the resolubility may be lowered due to an increase in the hydrophobic core portion.

  The resin fine particle dispersion of the present invention preferably has a minimum film-forming temperature (MFT) of −40 to 20 ° C. More preferably, it is -20-15 degreeC. If the MFT is less than −40 ° C., there is a possibility that the blocking resistance of the printed matter is deteriorated or the water friction resistance is deteriorated due to a decrease in coating film hardness. If the MFT exceeds 20 ° C., the resin fine particles are not formed into a film when used in the ink composition, and there is a possibility that the physical properties of the printed matter such as adhesion and water resistance of the printed matter are deteriorated. The minimum film-forming temperature can be controlled by the monomer composition and particle size. The minimum film forming temperature means the minimum temperature required for film formation by fusing polymer particles.

  Furthermore, the resin fine particle dispersion of the present invention preferably has an average particle size of 30 to 200 nm. More preferably, it is 40-100 nm. If the average particle size is smaller than 30 nm, the storage stability of the resin fine particle dispersion may be deteriorated. On the other hand, if the average particle size is larger than 200 nm, the film formation of the resin fine particle dispersion may occur, and the gloss, brightness, and water resistance of the printed matter may be reduced.

  The average particle diameter can be measured by the dynamic light scattering method as follows. The resin fine particle dispersion is diluted with water 500 times according to the solid content. About 5 ml of the diluted solution is injected into a cell of a measuring apparatus [Microtrack manufactured by Nikkiso Co., Ltd.], and the measurement is performed after inputting the solvent (water in the present invention) and the refractive index condition of the resin according to the sample. The peak of the volume particle size distribution data (histogram) obtained at this time is defined as the average particle size of the present invention.

  The aqueous ink composition of the present invention comprises a pigment, a pigment dispersion resin, a resin fine particle dispersion, and water.

As the pigment, pigments such as known organic pigments, inorganic pigments and extender pigments which are usually used in the technical field of printing inks or paints can be used.
As the pigment, for example, an achromatic pigment such as carbon black, titanium oxide, calcium carbonate, or a chromatic organic pigment can be used. Examples of organic pigments include insoluble azo pigments such as toluidine red, toluidine maroon, Hansa Yellow, Benzidine Yellow, and pyrazolone red, soluble azo pigments such as Ritol Red, Helio Bordeaux, Pigment Scarlet, and Permanent Red 2B, alizarin, indanthrone, and thioindigo. Derivatives from vat dyes such as maroon, phthalocyanine organic pigments such as phthalocyanine blue and phthalocyanine green, quinacridone organic pigments such as quinacridone red and quinacridone magenta, perylene organic pigments such as perylene red and perylene scarlet, isoindolinone yellow , Isoindolinone organic pigments such as isoindolinone orange, pyranthrone organic pigments such as pyranthrone red and pyranthrone orange, thioy Digo-based organic pigments, condensed azo-based organic pigments, benzimidazolone-based organic pigments, quinophthalone-based organic pigments such as quinophthalone yellow, isoindoline-based organic pigments such as isoindoline yellow, and other pigments such as flavanthrone yellow and acylamide yellow Nickel azo yellow, copper azomethine yellow, perinone orange, anthrone orange, dianthraquinonyl red, dioxazine violet and the like.

  Specific examples of carbon black include “Special Black 350, 250, 100, 550, 5, 4, 4A, 6” “Printex U, V, 140 U, 140 V, 95, 90, 85, 80, 75, 55, manufactured by Degussa. 45, 40, P, 60, L6, L, 300, 30, 3, 35, 25, A, G ", Cabot's" REGAL 400R, 660R, 330R, 250R "," MOGUL E, L ", Mitsubishi Chemical “MA7, 8, 11, 77, 100, 100R, 100S, 220, 230” “# 2700, # 2650, # 2600, # 200, # 2350, # 2300, # 2200, # 1000, # 990, # 980, # 970, # 960, # 950, # 900, # 850, # 750, # 650, # 52, # 50, # 47, # 45, # 4 5L, # 44, # 40, # 33, # 332, # 30, # 25, # 20, # 10, # 5, CF9, # 95, # 260 ”and the like.

  Specific examples of titanium oxide include “Taipeku CR-50, 50-2, 57, 80, 90, 93, 95, 953, 97, 60, 60-2, 63, 67, 58, 58- manufactured by Ishihara Sangyo Co., Ltd. 2, 85 "" Tipekes R-820, 830, 930, 550, 630, 680, 670, 580, 780, 780-2, 850, 855 "," Tipekes A-100, 220 "," Tipekes W-10 "," Tipekes " PF-740, 744 "" TTO-55 (A), 55 (B), 55 (C), 55 (D), 55 (S), 55 (N), 51 (A), 51 (C) " "TTO-S-1, 2", "TTO-M-1, 2", "Titanics JR-301, 403, 405, 600A, 605, 600E, 603, 805, 806, 701, 800, 808" manufactured by Teika "Titanic EN-1, C, 3, 4, 5 ", and the like manufactured by Du Pont" Taipyua R-900,902,960,706,931 ". The pigment is used in the range of 5 to 50% by weight, more preferably 8 to 45% by weight, based on the total weight of the solid components in the aqueous ink composition.

  Examples of extender pigments include carbonates such as calcium carbonate and magnesium carbonate, sulfates such as precipitated barium sulfate, and silicates such as silica, talc and mica, which are used alone or in combination of two or more. can do. In order to improve the blocking resistance and laminate strength of the ink composition, fillers known in the art can be added, and the above-mentioned extender pigments may be used for such purpose.

  The pigment dispersion resin used at the time of pigment dispersion is preferably a water-soluble resin having a carboxyl group from the viewpoint of dispersion stability in an aqueous system. For example, the acrylic copolymer (B), polyester system, polyamide system, and polyurethane system described above are used. These resins are mentioned. Commercially available products may be used for these resins.

  The pigment dispersion resin is preferably used in the range of 5 to 60% by weight based on the pigment. When the pigment dispersion resin is less than 5% by weight based on the pigment, the pigment dispersion stability is lowered, and there is a possibility that a problem may occur in the posting stability of the ink composition. On the other hand, if the pigment-dispersed resin exceeds 60% by weight with respect to the pigment, the water resistance of the printed matter may be lowered.

  The resin fine particle dispersion is preferably used in an amount of 10 to 60% by weight, more preferably 20 to 50% by weight, based on the total weight of the solid components in the aqueous ink composition. When the resin fine particle dispersion is less than 10% by weight, the binding between the printed material and the pigment particles or the pigment particles becomes insufficient, and the printed material may have reduced friction resistance and water resistance. On the other hand, when the resin fine particle dispersion exceeds 60% by weight, a sufficient pigment concentration may not be obtained.

An organic solvent can be used in combination with the aqueous ink composition of the present invention. The organic solvent used in the present invention is a known organic solvent that is usually used in the art, for example, alcohols such as methanol, ethanol, isopropanol, normal propanol, isobutanol, and normal butanol;
Esters such as methyl acetate, ethyl acetate, isopropyl acetate, normal propyl acetate, normal butyl acetate, and isobutyl acetate. Hydrocarbons such as toluene, xylene, cyclohexane, normal hexane, cyclohexane;
Examples include, but are not limited to, glycol esters such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, diethylene glycol monomethyl ether, and diethylene glycol monobutyl ether. It is not something. These can be used alone or in combination of two or more.

  The organic solvent is preferably used in an amount of 0.5 to 10% by weight based on 100% by weight in the aqueous ink composition. If the organic solvent is less than 0.5% by weight, the wettability of the ink composition to the film substrate may not be ensured. If it exceeds 10% by weight, air pollution and fire hazard that are characteristic of the aqueous ink composition may occur. There is a risk that safety such as safety and occupational hygiene may not be ensured.

  In gravure printing, a metal intaglio is used. Gravure printing is known as a printing method suitable for printing a large amount at a high speed. On the other hand, in flexographic printing, generally a resin relief plate is often used. Therefore, it is preferable to select a solvent having a quicker drying property for gravure printing even if the substrates to which printing is applied are the same. On the other hand, for flexographic printing, it is preferable to select a solvent that does not swell with respect to the resin plate. That is, in flexographic printing ink, it is preferable to use mainly an alcohol solvent, not an aromatic solvent or a ketone solvent. In flexographic printing inks, alcohol-based solvents can be used as a main component, and various solvents can be used in combination as long as the durability of the resin plate and the printing speed are not affected. As the flexographic ink, an ink having a high pigment concentration is generally used.

  The viscosity of the aqueous ink composition of the present invention is preferably in the range of 10 mPa · s to 1000 mPa · s. If the viscosity is less than 10 mPa · s, the pigment may precipitate. On the other hand, if the viscosity is higher than 1000 mPa · s, the working efficiency at the time of adjusting the ink composition may be deteriorated. The viscosity is a value obtained by measuring at 25 ° C. with a B-type viscometer manufactured by Tokimec. The viscosity of the ink can be adjusted by appropriately selecting the type of each component used as a raw material, for example, a polyurethane resin, a colorant, an organic solvent, and the like, and adjusting the blending amount appropriately. The viscosity of the ink can also be adjusted by adjusting the particle size and particle size distribution of the pigment in the ink.

EXAMPLES The present invention will be described more specifically with reference to the following examples. However, the following examples do not limit the scope of rights of the present invention. In the examples, “part” represents “part by weight” and “%” represents “% by weight”.
<Synthesis of resin fine particle dispersion>
[Example 1]
In a reaction vessel equipped with a stirrer, a thermometer, a dropping funnel and a reflux condenser, 120 parts of ion-exchanged water, 10 parts of X-10087 (Baker Hughes), 30 parts of JONCRYL67 (BASF) and 9.3% 25% ammonia The temperature in the reaction system was raised to 70 ° C. to obtain a translucent water-soluble resin dispersion. After adding 11 parts of a 5% aqueous solution of potassium persulfate, 22.5 parts of methyl methacrylate, 25.5 parts of 2-ethylhexyl acrylate, and 12.0 parts of ethyl acrylate were added over 3 hours while maintaining the reaction system at 70 ° C. The polymerization was conducted dropwise, and stirring was continued for another 2 hours. Then, it cooled and solid content was adjusted to 40% with ion-exchange water, and the milky white resin fine particle dispersion of MFT-8 degreeC and acid value 77mgKOH / g was obtained.
[Examples 2 to 16]
The composition shown in Table 1 was synthesized in the same manner as in Production Example 1 to obtain a milky white resin fine particle dispersion.
[Comparative Examples 1 and 2]
The composition shown in Table 1 was synthesized in the same manner as in Example 1 to obtain a milky white resin fine particle dispersion.
[Comparative Example 3]
A reaction vessel was charged with 55 parts of ion-exchanged water, 10 parts of X-10087 (Baker Hughes), 30 parts of JONCRYL 67 (BASF) and 9.3 parts of 25% ammonia, and the reaction system was heated to 70 ° C. After dissolution, the mixture was cooled and the solid content was adjusted to 40% with ion exchange water to obtain a translucent water-soluble resin dispersion having an acid value of 190 mgKOH / g.
(Polymerization stability)
The resin fine particle dispersions obtained in Examples 1 to 16 and Comparative Examples 1 to 9 were filtered through a 100 mesh filter cloth, and the dry weight of the residue remaining on the filter cloth was measured and evaluated according to the following criteria.
A: Less than 0.1 g per 1 kg of resin fine particle dispersion O: 0.1 g or more to less than 0.5 g per 1 kg of resin fine particle dispersion Δ: 0.5 g or more to less than 1.0 g per 1 kg of resin fine particle dispersion x: Resin fine particles 1.0 g or more per 1 kg of dispersion is in the range where there is no practical problem.
[Example 17]
A water-based ink composition of the present invention was produced by dispersing a mixture having the following composition with a sand mill.
Pigment (titanium oxide) 32.4 parts Pigment dispersion resin (JONCRYL67) 3 parts Additive 0.7 parts Polyethylene wax 5 parts Resin fine particle dispersion (Production Example 1) 41 parts Isopropyl alcohol 2.5 parts Water 15.4 parts
Total 100 parts [Examples 18 to 36, Comparative Examples 4 to 6]
Ink compositions were prepared in the same manner as in Example 17 with the composition shown in Table 2.

  Next, a single-sided corona-treated OPP film “Pyrene P2161” manufactured by Toyobo Co., Ltd. was used with each of the obtained ink compositions using a “SOLOFLEX” central impression (CI) 6-color flexographic printing machine manufactured by Windmiller & Helscher. A printed layer was formed on the corona-treated surface of to obtain a printed matter.

As described above, the ink viscosity of each of the aqueous ink compositions of Examples 17 to 36 and Comparative Examples 4 to 6 is No. with water and pigment dispersion resin. Adjust to 10-15 seconds with 4 Zaan cups. About each adjusted ink composition, (1) storage stability (2) re-dissolvability, and for each printed matter (3) adhesion, (4) water rub resistance, (5) anti-blocking properties, etc. Evaluated. The results are shown in Table 3.
(1) Storage stability The prepared ink composition stored for 2 weeks in a heat-retaining container at 40 ° C. is cooled to 25 ° C. The viscosity was measured with a 4 Zaan cup and evaluated according to the following criteria.
◎: Increase in viscosity is less than 3 seconds of finished viscosity ○: Increase in viscosity is from 3 seconds to less than 5 seconds when finished viscosity Δ: Increase in viscosity is from 5 seconds to less than 10 seconds when finished viscosity X: Increase in viscosity is finished When the viscosity is 10 seconds or more, ◎ and ○ are ranges where there is no practical problem.
(2) Each adjusted ink composition is dropped on a printed matter left for 24 hours after re-dissolvable printing, and the ink is quickly wiped with absorbent cotton. The time from dripping to wiping was gradually increased, and the time until the ink was completely dissolved was measured and evaluated according to the following criteria.
A: The coating film is completely dissolved within 1 second after dropping. O: The coating film is completely dissolved within 3 seconds from dropping. A: The coating film is completely dissolved within 5 seconds after dropping. It takes 5 seconds or more from dropping until complete dissolution.
(3) Adhesion Nichiban cellophane tape (10 mm width) is applied to the printed surface, then the cellophane tape is slowly peeled off the printed surface, and the peeled state of the ink coating on the cellophane tape is measured. It was evaluated with.
A: Ink film peeling is less than 10% B: Ink coating film peeling is 10% or more and less than 25% Δ: Ink coating film peeling is 25% or more and less than 50% X: Ink coating film peeling is 50% or more A and O are ranges where there is no practical problem.
(4) After immersing the water rub-resistant printed material in tap water for 3 hours, use a new type fastness friction tester and rub it with cotton cloth (Kanakin No. 3) containing tap water under a load of 200 g and 50 round trips. The state of ink dissolution was measured and evaluated according to the following criteria.
A: No color on the cotton cloth ○: The color on the cotton cloth is visible but the film is not visible Δ: The color is on the cotton cloth and less than 50% of the film is visible ×: The color is on the cotton cloth and 50% of the film is on % Or more where% or more is visible is a range where there is no practical problem.

(5) Anti-blocking property The film is overlapped so that the printed surface and the non-printed surface of the printed matter are in contact with each other, applied with a load of 10 kgf / cm ² , and allowed to stand in an environment of 40 ° C. and 80% RH for 24 hours. The state of ink transfer to the non-printing surface was measured and evaluated according to the following criteria.
◎ ・ ・ ・ 0% transfer of ink to non-printing surface
○: Transfer amount less than 10% Δ: Transfer amount of 10% or more and less than 30% x… Transition amount of 30% or more A and ○ are ranges where there is no practical problem.

  As shown in Table 2, the aqueous ink compositions of Examples 17 to 36 are all in ink suitability (storage stability, re-dissolvability) and coating film resistance (adhesion, water rub resistance, blocking resistance) of the printed matter. I found it excellent. On the other hand, the aqueous ink compositions of Comparative Examples 4 to 6 had poor ink suitability and coating film resistance.

Claims (8)

  An ethylenically unsaturated monomer (C) is emulsion-polymerized in an aqueous medium in the presence of an olefin copolymer (excluding an acrylic copolymer) (A) and an acrylic copolymer (B). A resin fine particle dispersion characterized by the above.   The olefin copolymer (A) has an acid value of 50 to 300 mgKOH / g, the acrylic copolymer (B) has an acid value of 50 to 300 mgKOH / g and a weight average molecular weight of 500 to 30000. Resin fine particle dispersion.   The olefin copolymer (A) is at least one selected from a terminal acid-modified olefin copolymer (a1), an acid graft-modified olefin copolymer (a2), and an α-olefin maleic anhydride copolymer (a3). The resin fine particle dispersion according to claim 1, wherein the resin fine particle dispersion is a copolymer.  In the presence of 1 to 40 parts by weight of the olefin copolymer (A) and 20 to 40 parts by weight of the acrylic copolymer (B), 40 to 70 parts by weight of the ethylenically unsaturated monomer (C) is added to the aqueous medium. The resin fine particle dispersion according to any one of claims 1 to 3, wherein the resin fine particle dispersion is obtained by emulsion polymerization.  The resin fine particle dispersion according to any one of claims 1 to 4, wherein the minimum film-forming temperature (MFT) is -40 to 20 ° C.  A water-based ink composition comprising a pigment and the resin fine particle dispersion according to claim 1.  The water-based ink composition according to claim 6, which is used for flexographic or gravure printing.   The water-based ink composition according to claim 7, which is used for an olefin copolymer substrate.