JP6565356B2 - Acrylic / urethane composite resin for water-based ink and water-based ink composition. - Google Patents

Description

  The present invention relates to an acrylic / urethane composite resin for water-based ink and a water-based ink composition.

In recent years, from the viewpoints of energy saving, low cost, and reduction of environmental impact, water-based inks that can exhibit excellent adhesion and coating film resistance to nonpolar film substrates in various ink markets such as gravure, flexo, and inkjet have been developed. I'm in a hurry. In these water-based inks, an acrylic resin excellent in pigment dispersibility and abrasion resistance and a urethane resin excellent in substrate adhesion are used. In addition, in order to make use of the advantages of each resin, a blend system of acrylic resin and urethane resin and a composite resin have been actively studied. However, in general, the compatibility between acrylic resin and urethane resin is not good, so simple blending and compounding cannot improve the coating resistance, but rather it becomes a fragile coating, which greatly deteriorates the coating resistance. Tended to be.

Patent Document 1 discloses a core-shell composite resin for water-based ink in which the shell component is an aqueous urethane resin and the core component is an acrylic resin. By introducing a hydrazide group into a urethane resin and a keto group into an acrylic resin, and crosslinking at different temperatures between different resins, we are trying to improve coating film resistance. However, in this design, the compatibility between the urethane resin and the acrylic resin before cross-linking is poor, and even if the cross-linking is finally performed, the coating film resistance is not dramatically improved. Moreover, since it is an emulsion type, the pigment dispersibility is remarkably bad.

Patent Document 2 discloses an acrylic / urethane composite resin for water-based ink in which an acrylic moiety is grafted by introducing an ethylenically unsaturated group into a urethane skeleton and copolymerizing with an ethylenically unsaturated monomer. . However, in this method, the urethane resin portion has a three-dimensional high molecular weight. Therefore, the mobility of the molecular chain is reduced, and the compatibility between the urethane part and the acrylic part is also significantly reduced. Under low temperature drying conditions, sufficient fusion cannot be achieved between the resins, and excellent film resistance can be expressed. Can not. This type is also inferior in pigment dispersion.

Patent Document 3 discloses an acrylic / urethane composite resin for water-based ink in which a mercapto group is introduced at the end of a urethane resin and an acrylic portion is grafted by a chain transfer reaction. With this method, the three-dimensional increase in the molecular weight of the urethane portion can be avoided. However, this resin has problems such as good dispersion stability of the inorganic pigment, adhesion to an untreated film substrate, excellent water friction resistance, and poor water blocking resistance.

JP 1995-188353 Japanese Patent Laid-Open No. 1995-082456 JP 2000-345092 A

Excellent dispersion stability and storage stability of organic and inorganic pigments, low odor, and excellent substrate adhesion, water rub resistance, and scratch resistance against processed and untreated film substrates even under low temperature drying It is an object to provide an acrylic / urethane composite resin for water-based inks exhibiting water resistance and water blocking resistance, and a water-based ink composition using the same.

That is, in the present invention, an acid obtained by reacting the compound (D) represented by the general formula (1) with the urethane prepolymer (C-1) obtained by reacting the polyol (A) and the polyisocyanate (B). It is an acrylic / urethane composite resin for water-based inks obtained by polymerizing an ethylenically unsaturated monomer (E) using a urethane transfer resin (C-2) containing both end mercapto groups having a valence of less than 5 mgKOH / g as a chain transfer agent. And
Acrylic / urethane composite for water-based inks obtained by reacting ethylenically unsaturated monomer (E) in the range of 30 to 180 parts by weight per 100 parts by weight of both end mercapto group-containing urethane urea resin (C-2) It relates to resin.
General formula (1)

(In general formula (1), X represents hydrogen or an alkyl group.
R is at least one divalent group selected from the group consisting of an alkylene group, an arylene group, and an alkylene oxide group. )

Moreover, this invention reacts compound (D) represented by General formula (1) in the range of 0.60-0.90 mol with respect to 1 mol of isocyanate groups of a urethane prepolymer (C-1). The present invention relates to the acrylic / urethane composite resin for water-based ink.

In the present invention, the polyol (A) is a polyether polyol (a-1), a polyester polyol (a-2), a polycarbonate polyol (a-3), a polyolefin-based polyol (a-4), and a castor oil polyol. The present invention relates to the acrylic-urethane composite resin for water-based inks containing at least one selected from the group consisting of:

The present invention also provides the acrylic / urethane composite for water-based ink, in which the polyol (A) comprises a polyether polyol (a-1) and / or a polycarbonate polyol (a-3) and a polyester polyol (a-2). It relates to resin.

The present invention also relates to a water-based ink composition comprising the acrylic-urethane resin for water-based ink, a pigment, a hydrophilic solvent, and water.

Moreover, this invention makes the compound (D) represented by General formula (1) react with the urethane prepolymer (C-1) formed by making a polyol (A) and a polyisocyanate (B) react. A process for producing an acrylic / urethane composite resin for water-based inks by polymerizing an ethylenically unsaturated monomer (E) using a urethane transfer resin (C-2) containing both end mercapto groups having an acid value of less than 5 mgKOH / g as a chain transfer agent Because
An acrylic / urethane composite resin for water-based inks in which an ethylenically unsaturated monomer (E) is reacted in an amount of 30 to 180 parts by weight with respect to 100 parts by weight of a both-end mercapto group-containing urethane urea resin (C-2). It relates to a manufacturing method.

General formula (1)

(In general formula (1), X represents hydrogen or an alkyl group.
R is at least one divalent group selected from the group consisting of an alkylene group, an arylene group, and an alkylene oxide group. )

The urethane / acrylic composite resin for water-based inks of the present invention is excellent in dispersion stability of organic and inorganic pigments and excellent in storage stability of the ink composition. In addition, the ink coating film exhibits excellent substrate adhesion, water rub resistance, scratch resistance, water blocking resistance and low odor even with low-temperature drying even on a treated / untreated film substrate.

First, the acrylic / urethane composite resin for water-based ink of the present invention will be described. The acrylic / urethane composite resin for water-based ink of the present invention has a structure in which an acrylic resin is grafted from both ends of the urethane resin, and is composed of a hydrophobic urethane skeleton and a hydrophilic acrylic skeleton. Due to its hydrophobicity and hydrophilicity contrast, it is excellent in adsorption power and dispersion stability on the pigment surface. Moreover, it is excellent also in the adsorptive power to a nonpolar film base material. Furthermore, a tough coating film that satisfies both the hardness of the acrylic skeleton and the flexibility of the urethane skeleton can be formed. This resin can be obtained by synthesizing a urethane urea resin having a mercapto group terminal and radical polymerization of the ethylenically unsaturated monomer (E) using the resin as a chain transfer agent. The production method of the acrylic / urethane composite resin for water-based ink of the present invention will be specifically described.
First, the polyol (A) and the polyisocyanate (B) are charged into a reaction vessel, and a catalyst is added to react to synthesize a urethane prepolymer (C-1) having isocyanate groups at both ends. Next, when a compound (D) having one amino group and one mercapto group in one molecule is added and reacted, first, the amino group and the isocyanate group react preferentially to form a urea bond. However, when the isocyanate group is charged in excess with respect to the amino group, the remaining isocyanate group and mercapto group further react to extend the chain. Thereby, a urethane urea resin (C-1) having mercapto groups introduced at both ends can be synthesized. Furthermore, by adding ethylenically unsaturated monomer (E) and solvent, and adding radical initiator under nitrogen atmosphere, acrylic resin component from both ends of urethane urea resin (C-1) by chain transfer reaction Is grafted. Finally, ion-exchanged water and, if necessary, a neutralizing agent are added, and a solvent dispersion treatment is performed to obtain an aqueous dispersion of the target acrylic / urethane composite resin for water-based ink.

<Polyol (A)>
Typical examples of the polyol (A) used for the urethane prepolymer (C-1) include polyether polyol (a-1), polyester polyol (a-2), polycarbonate polyol (a-3), and polyolefin. Based polyol (a-4), castor oil polyol and the like. These polyols may use only 1 type and may use multiple types together.

Examples of the polyether polyol (a-1) include polymers or copolymers such as methylene oxide, ethylene oxide, propylene oxide, and tetrahydrofuran, specifically, polyethylene glycol, polypropylene glycol, poly (ethylene / propylene) glycol. And polytetramethylene glycol. Moreover, the polyether polyols by condensation of hexanediol, methylhexanediol, heptanediol, octanediol, or a mixture thereof can be used.

  Examples of the polyester polyol (a-2) include a polyester polyol obtained by condensation reaction of a polyol component and a dibasic acid component. Among the polyols, diols include ethylene glycol, propylene glycol, dipropylene glycol, diethylene glycol, triethylene glycol, butylene glycol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, and 3,3′-diene. Methylol heptane, polyoxyethylene glycol, polyoxypropylene glycol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, octanediol, butylethylpentanediol, 2-ethyl-1,3-hexanediol, Examples of the polyol having three or more hydroxyl groups include glycerin, trimethylolpropane, pentaerythritol, and the like as dibasic acid components. Terephthalic acid, adipic acid, azelaic acid, sebacic acid, dimer acid, hydrogenated dimer acid, phthalic acid anhydride, isophthalic acid, aliphatic or aromatic dibasic acids such as trimellitic acid, and anhydrides thereof. Moreover, the polyester polyol obtained by ring-opening polymerization of cyclic ester compounds, such as lactones, such as (epsilon) -caprolactone, poly ((beta) -methyl-gamma-valerolactone), and polyvalerolactone, is mentioned.

  Examples of the polycarbonate polyol (a-3) include those obtained by a reaction between a polyol and a carbonate compound such as dialkyl carbonate, alkylene carbonate, and diaryl carbonate. As a polyol which comprises a polycarbonate polyol, the polyol illustrated previously as a structural component of a polyester polyol can be used. Examples of the dialkyl carbonate include dimethyl carbonate and diethyl carbonate, examples of the alkylene carbonate include ethylene carbonate, and examples of the diaryl carbonate include diphenyl carbonate.

Examples of the polyolefin-based polyol (a-4) 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. .

Castor oil polyol is a biopolyol derived from plant-derived castor oil.

Among the polyols (A) described above, the polyol (A) contains the polyether polyol (a-1) and / or the polycarbonate polyol (a-3) and the polyester polyol (a-2). More preferred. The combination of the above polyols improves hydrolytic stability in water and improves the storage stability of the ink. The compatibility of the hydrophilic acrylic skeleton and the hydrophobic urethane skeleton is also particularly good in this polyol combination, so it is easy to form a tough coating, and the adhesion of the ink coating to the substrate and water resistance friction Improves.

<Polyisocyanate (B)>
Examples of the polyisocyanate (B) to be reacted with the polyol (A) include aromatic, aliphatic and alicyclic polyisocyanates. These may use only 1 type or may use multiple types together.

  Examples of the aromatic polyisocyanate include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate, 4,4′-diphenylmethane diisocyanate, xylylene diisocyanate, lysine diisocyanate, 3,3′-dimethyl-4,4′-biphenylene diisocyanate, 3,3′-dimethoxy-4,4′-biphenylene diisocyanate, 3,3′-dichloro-4,4′-biphenylene diisocyanate, 1,5-naphthalene Examples include diisocyanate and 1,5-tetrahydronaphthalene diisocyanate.

  Examples of the aliphatic polyisocyanate include tetramethylene diisocyanate, hexamethylene diisocyanate, and trimethylhexamethylene diisocyanate.

  Examples of the alicyclic polyisocyanate include isophorone diisocyanate, 1,4-cyclohexylene diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, and the like.

<Urethane prepolymer (C-1)>
A urethane prepolymer (C-1) can be obtained by reacting the polyol (A) with the polyisocyanate (B).
At that time, a low molecular diol can be used in combination with the polyol (A) for the purpose of adjusting the urethane bond concentration and introducing various functional groups. As the low molecular diol, a diol having a molecular weight of 500 or less is preferable.
Ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, pentanediol, hexanediol, octanediol, 2-butyl-2- Ethyl-1,3-propanediol, 1,4-butylenediol, dipropylene glycol, glycerin, trimethylolpropane, trimethylolethane, 1,2,6-butanetriol, pentaerythritol, sorbitol, N, N-bis ( 2-hydroxypropyl) aniline, dimethylolacetic acid, dimethylolpropionic acid, dimethylolbutanoic acid, 2,2-dimethylolbutyric acid, dimethylolalkanoic acid such as 2,2-dimethylolpentanoic acid, dihydroxysuccinic acid, dihydroxypropionic acid , Dihydroxy And benzoic acid.

Moreover, a catalyst can also be used in the reaction for obtaining the urethane prepolymer. As the catalyst that can be used, a known metal catalyst or amine catalyst can be used. Examples of metal catalysts include dibutyltin dilaurate, tin octoate, dibutyltin di (2-ethylhexoate), lead 2-ethylhexoate, 2-ethylhexyl titanate, titanium ethyl acetate, 2-ethylhexoate Examples thereof include iron, 2-ethylhexoate cobalt, zinc naphthenate, cobalt naphthenate, and tetra-n-butyltin. Examples of amine-based catalysts include tertiary amines such as tetramethylbutanediamine. These catalysts are used in the range of 0.001 to 1 mol% with respect to the polymer polyol.

The reaction for obtaining the urethane prepolymer is preferably carried out at 50 to 150 ° C. for 2 to 10 hours. The end point of the reaction is judged by measuring NCO% by titration.

As a solvent that can be used to obtain a urethane prepolymer, any solvent that does not react with an isocyanate group can be used, but in view of the subsequent solvent removal step, it is removed by azeotropy with water. It is preferable to use a solvent that can be easily treated. It is also possible to carry out the reaction without solvent and dilute the solvent later. Preferred solvents include ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone;
Ester solvents such as ethyl acetate, propyl acetate, butyl acetate;
And glycol ester solvents such as ethylene glycol monomethyl ether acetate and propylene glycol monomethyl ether acetate.

  Although the weight average molecular weight of a urethane prepolymer is not specifically limited, 5000-30000 are preferable and 8000-18000 are more preferable.

<Compound (D) Represented by General Formula (1)>
By reacting the urethane prepolymer (C-1) with the compound (D) represented by the general formula (1), a urethane urea resin (C-2) having mercapto groups at both ends can be obtained.

General formula (1)

(In general formula (1), X represents hydrogen or an alkyl group.
R is at least one divalent group selected from the group consisting of an alkylene group, an arylene group, and an alkylene oxide group. )

Examples of the alkyl group in X include alkyl groups having 1 to 12 carbon atoms such as a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, and a dodecyl group. A C1-C6 alkyl group is preferable.
Examples of the alkylene group in R include an alkylene group having 1 to 12 carbon atoms such as a methylene group, an ethylene group, a propylene group, a butylene group, a pentylene group, a hexylene group, a heptylene group, an octylene group, and a dodecylene group. The alkylene group of number 1-6 is preferable.
Examples of the arylene group include a phenylene group, and examples of the alkylene oxide group include ethylene oxide, propylene oxide, and butylene oxide. R is preferably an alkylene group or an arylene group.

As a suitable example of the compound (D) represented by the general formula (1),
Aminoalkanethiols such as 2-aminoethanethiol, 3-aminopropyl-1-thiol, 1-aminopropyl-2-thiol, 4-amino-1-butanethiol;
Aminobenzenethiols such as 2-aminothiophenol, 3-aminothiophenol, 4-aminothiophenol;
Is mentioned.

When a mercapto group is introduced at the end of the urethane prepolymer (C-1), it is preferable to use the compound (D) represented by the general formula (1). When a compound having a hydroxyl group is used instead of an amino group, the side reaction between the mercapto group and the isocyanate group proceeds at a high rate because the difference in reactivity between the hydroxyl group and the mercapto group is small. Therefore, it is difficult to introduce a mercapto group accurately at the resin terminal. In addition, when a compound having two mercapto groups is used, it is unsuitable for use in water-based ink applications due to significant coloring and odor.

When the compound (D) represented by the general formula (1) is used, an amino group preferentially reacts with an isocyanate group in the urethane prepolymer (C-1) to form a urea bond. Further, when the number of moles of the isocyanate group is excessive with respect to the number of moles of the compound (D) represented by the general formula (1), the remaining isocyanate group reacts with the mercapto group to form a chain. The urethane prepolymer (C-1) is increased in molecular weight. At this time, in addition to both ends of the urethane prepolymer (C-1), urea bonds are introduced inside the skeleton, so that the cohesive strength of the urethane resin is improved and the water friction resistance of the ink coating is dramatically improved. To improve. Moreover, since the unreacted compound (D) is also reduced, the odor of the printed matter is greatly improved.

For the above reasons, when producing the urethane urea resin (C-2) containing both terminal mercapto groups, the isocyanate group of the urethane prepolymer (C-1) is converted into the compound (D) represented by the general formula (1). On the other hand, it is preferable to prepare to be excessive. Further, the compound (D) represented by the general formula (1) is preferably reacted so as to be 0.60 to 0.90 mol with respect to 1 mol of the isocyanate group of the urethane prepolymer (C-1). . The charge amount of 0.6 mol or more is preferable because the acrylic skeleton is easily incorporated into the urethane skeleton, and the desired composite resin is easily obtained. The ink storage stability, water friction resistance, and substrate adhesion are excellent. On the other hand, when the amount is 0.90 mol or less, the amount of the unreacted compound (D) that is not incorporated into the resin is reduced, which is excellent in terms of water friction resistance and odor of the ink coating film.

<Both-end mercapto group-containing urethane urea resin (C-2)>
The acid value of the urethane urea resin (C-2) having a mercapto group at both ends is preferably less than 5 mgKOH / g, more preferably less than 4 mgKOH / g, and further it does not contain an anionic functional group. preferable. In the composite resin of the present invention, the urethane resin skeleton part has a role of adsorbing to a hydrophobic interface such as a pigment surface or a film substrate. Therefore, when the acid value exceeds 5 mgKOH / g, the pigment adsorbing ability of the urethane skeleton is remarkably lowered, so that the dispersion stability and storage stability of the ink are also deteriorated. At the same time, the hydrophobic interaction on the untreated film surface is also inhibited, so that the substrate adhesion is greatly reduced. Furthermore, since the drying property at the time of printing is also lowered, the water blocking resistance and odor of the ink coating film are also adversely affected. In this specification, an acid value is the number of mg of potassium hydroxide required to neutralize the acidic component contained in 1 g of resin, and can be determined by the method described in the examples.

The reaction for obtaining the both-end mercapto group-containing urethane urea resin (C-2) is preferably carried out at 50 to 100 ° C. for 30 minutes to 4 hours. The end point of the reaction can be confirmed by disappearance of the NCO peak by IR measurement.

As the solvent that can be used for obtaining the both-end mercapto group-containing urethane urea resin (C-2), any solvent that can dissolve the raw material and does not react with the isocyanate group can be used. It is preferable to use a solvent that is easy to remove by azeotropy with water. Preferred solvents include ketone solvents such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; ester solvents such as ethyl acetate, propyl acetate, and butyl acetate; glycol ester solvents such as ethylene glycol monomethyl ether acetate and propylene glycol monomethyl ether acetate; Etc., and ketone solvents are preferred.

  Although the weight average molecular weight of both end mercapto group containing urethane urea resin (C-2) is not specifically limited, 10,000-100000 are preferable and 15000-90000 are more preferable.

<Ethylenically unsaturated monomer (E)>
An acrylic / urethane composite resin can be obtained by radical polymerization of the ethylenically unsaturated monomer (E) in the presence of the both-end mercapto group-containing urethane urea resin (C-2). In the composite resin of the present invention, since the acrylic skeleton part functions as a hydrophilic group, the ethylenically unsaturated monomer (E) may contain a hydrophilic group-containing ethylenically unsaturated monomer (e-1). preferable. Depending on the functional group of the ethylenically unsaturated monomer to be used, an anionic, cationic or nonionic hydrophilic group can be appropriately introduced.

As the hydrophilic group-containing ethylenically unsaturated monomer (e-1), for example,
As having an anionic hydrophilic group,
Maleic acid, maleic anhydride, fumaric acid, itaconic acid, citraconic acid, or alkyl or alkenyl monoesters thereof, hexahydrophthalic acid β- (meth) acryloxyethyl monoester, succinic acid β- (meth) acryloxy Carboxyl group-containing ethylenically unsaturated monomers such as ethyl monoester, acrylic acid, methacrylic acid, crotonic acid, cinnamic acid; styrene sulfonic acid, sodium styrene sulfonate, ammonium styrene sulfonate, lithium styrene sulfonate, 2- Acrylamide 2-methylpropanesulfonic acid, sodium 2-acrylamido-2-methylpropanesulfonate, methallylsulfonic acid, sodium methallylsulfonate, allyl sulfonic acid, sodium allyl sulfonate, ammonium allyl sulfonate Sulfonic acid group-containing ethylenically unsaturated monomers such as vinyl sulfonic acid, allyloxybenzene sulfonic acid, sodium allyloxybenzene sulfonate, ammonium allyloxybenzene sulfonate;
Ethylene phosphate-containing ethylene such as 2-methacryloyloxyethyl acid phosphate, 2-acryloyloxyethyl acid phosphate, diphenyl-2-acryloyloxyethyl phosphate, diphenyl-2-methacryloyloxyethyl phosphate, dibutyl-2-acryloyloxyethyl phosphate Unsaturated monomers;
As having a cationic hydrophilic group,
Amino group-containing ethylenically unsaturated monomers such as dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, methylethylaminoethyl (meth) acrylate, dimethylaminostyrene, diethylaminostyrene;
As having a nonionic hydrophilic group,
Polyethylene glycol mono (meth) acrylate (Nippon Yushi Co., Ltd., Bremer PE-90, 200, 350, 350G, AE-90, 200, 400, etc.) Polyethylene glycol / polypropylene glycol mono (meth) acrylate (Nippon Yushi Co., Ltd., Blemmer 50PEP-300, 70PEP-350, etc.), polyethylene oxide group-containing ethylenically unsaturated monomers such as methoxypolyethylene glycol mono (meth) acrylate (manufactured by NOF Corporation, BLEMMER PME-400, 550, 1000, 4000, etc.);
(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 ethylenically unsaturated monomers such as acrylamide, N, N-diethylacrylamide, diacetone (meth) acrylamide;
Hydroxyl group-containing ethylenically unsaturated monomers such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, glycerol mono (meth) acrylate, allyl alcohol;
However, it is not particularly limited to these. These can be used alone or in combination of two or more.

Examples of other ethylenically unsaturated monomer (e-2) copolymerizable with the hydrophilic group-containing ethylenically unsaturated monomer (e-1) include:
Styrene, α-methyl styrene, o-methyl styrene, p-methyl styrene, m-methyl styrene, vinyl naphthalene, benzyl acrylate, benzyl methacrylate, phenoxyethyl acrylate, phenoxyethyl methacrylate, phenoxydiethylene glycol acrylate, phenoxydiethylene glycol methacrylate, phenoxytetraethylene Aromatic-containing ethylenically unsaturated monomers such as glycol acrylate, phenoxytetraethylene glycol methacrylate, phenoxyhexaethylene glycol acrylate, phenoxyhexaethylene glycol methacrylate, phenyl acrylate, and phenyl methacrylate;
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 ethylenically unsaturated monomers such as
Alicyclic alkyl group-containing ethylenically unsaturated monomers such as cyclohexyl (meth) acrylate and isobornyl (meth) acrylate;
Fluorinated alkyl group-containing ethylenically unsaturated monomers such as trifluoroethyl (meth) acrylate and heptadecafluorodecyl (meth) acrylate;
Keto group-containing ethylenically unsaturated monomers such as 2-acetoacetoxyethyl (meth) acrylate;
Allyl (meth) acrylate, vinyl (meth) acrylate, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, polyethylene glycol (meth) acrylate, 1,4-butanediol di (Meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, 1,10-decanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, Glycerin dimethacrylate, dimethylol tricyclodecane di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra ( Data) acrylate, divinylbenzene, divinyl adipate, diallyl isophthalate, diallyl phthalate, ethylenically unsaturated monomer having two or more ethylenically unsaturated groups such as diallyl maleate;
Epoxy group-containing ethylenically unsaturated monomers such as glycidyl (meth) acrylate and 3,4-epoxycyclohexyl (meth) acrylate;
γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltriethoxysilane, γ-methacryloxypropyltributoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ-acryloxy Propyltrimethoxysilane, γ-acryloxypropyltriethoxysilane, γ-acryloxypropylmethyldimethoxysilane, γ-methacryloxymethyltrimethoxysilane, γ-acryloxymethyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane , An alkoxysilyl group-containing ethylenically unsaturated monomer such as vinyltributoxysilane, vinylmethyldimethoxysilane, etc., but is not particularly limited thereto. These can be used alone or in combination of two or more.

Among the above-mentioned hydrophilic group-containing ethylenically unsaturated monomers (e-1), it is preferable to use a carboxyl group-containing ethylenically unsaturated monomer in consideration of the water resistance of the printed film after drying. Of these, methacrylic acid is more preferably used. The ink coating film using the carboxyl group-containing ethylenically unsaturated monomer is excellent in coating film resistance (water friction resistance and water blocking resistance) as compared with the case where other hydrophilic groups are introduced. In particular, when methacrylic acid is used, the coating film has excellent film-forming properties and exhibits good coating film resistance.

When the hydrophilic group is an anionic group, the acid value of the acrylic resin portion in the composite resin is preferably in the range of 30 to 300 mgKOH / g, and more preferably in the range of 40 to 200 mgKOH / g. When the acid value is 30 mgKOH / g or more, the dispersion stability of the composite resin is good and the ink physical properties are excellent. On the other hand, if it is 300 mgKOH / g or less, the drying property of the ink coating film is good, so that it is excellent in water friction resistance and water blocking resistance.

The above-mentioned ethylenically unsaturated monomer (E) is preferably composed of a monomer that does not contain an acryloyl group, and in view of copolymerizability and residual monomer, it may be composed only of a methacryloyl group-containing monomer. Is more preferable. When acryloyl group is contained, side reaction in which acryloyl group is added to mercapto group in urethane resin occurs in part, and grafting of acrylic part is inhibited, resulting in deterioration of water rub resistance and substrate adhesion of printed matter. There is a case. On the other hand, in the case where it is composed only of a methacryloyl group-containing monomer, since there is no concern as described above, more excellent ink physical properties and coating film physical properties are exhibited.

<Acrylic / urethane composite resin>
In the acrylic / urethane compounding step, the amount of the ethylenically unsaturated monomer (E) is 30 to 180 parts by weight with respect to 100 parts by weight of the both-end mercapto group-containing urethane urea resin (C-2). Is preferred. When the ethylenically unsaturated monomer (E) is less than 30 parts by weight, the strength of the coating film is insufficient, and the water friction resistance and scratch resistance of the ink coating film are remarkably deteriorated. On the other hand, when the amount exceeds 180 parts by weight, the pigment adsorbing ability is greatly lowered as the amount of the hydrophobic urethane skeleton decreases. Accordingly, the dispersion stability and storage stability of the ink are deteriorated. In addition, the hydrophobic interaction with the substrate is similarly reduced, and the adsorptive power to the untreated film substrate is also reduced, so that the substrate adhesion, water friction resistance, and scratch resistance of the ink coating film are significantly deteriorated. . More preferably, it is the range of 60-110 weight part, and is excellent by base-material adhesiveness and water-resistant friction property.

As the radical initiator used in the acrylic / urethane complexing reaction, a known oil-soluble polymerization initiator can be used. For example, benzoyl peroxide, tert-butyl peroxybenzoate, tert-butyl hydroperoxide, tert- Organic peroxides such as butyl peroxy (2-ethylhexanoate), tert-butylperoxy-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.

The radical initiator is preferably used in the range of 0.1 to 0.5 parts by weight with respect to 100% by weight of the ethylenically unsaturated monomer (E). If it is less than 0.1% by weight, the polymerization reaction does not proceed sufficiently, the raw material components remain, and the ink coating film properties such as odor may be deteriorated. On the other hand, if the amount exceeds 0.5 parts by weight, the acrylic resin component generated alone does not chain transfer to the mercapto group of the both-end mercapto group-containing urethane urea resin (c-2). The substrate adhesion may be deteriorated.

As the solvent used in the complexing reaction, any solvent can be used as long as it dissolves the raw materials and the composite resin. However, in consideration of the subsequent solvent removal step, the solvent is azeotroped with water. It is preferable to use a solvent that is easy to remove. Preferred solvents include ketone solvents such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; ester solvents such as ethyl acetate, propyl acetate, and butyl acetate; glycol ester solvents such as ethylene glycol monomethyl ether acetate and propylene glycol monomethyl ether acetate;
Alcohol solvents such as ethanol, isopropyl alcohol, n-butanol;
Etc., and ketone solvents are preferred.

  Although the weight average molecular weight of acrylic urethane composite resin is not specifically limited, 20000-200000 are preferable and 30000-120,000 are more preferable.

As a preferred method for making the composite resin of the present invention aqueous, first, ion-exchanged water and, if necessary, a basic compound are added to the composite resin that has been reacted and stirred. The basic compound is used as a neutralizing agent when the hydrophilic group of the composite resin is anionic and unneutralized. When the whole becomes uniform, the solvent removal treatment is started to remove the organic solvent. Solvent removal can be performed under reduced pressure using an aspirator or a vacuum pump as necessary.

As a basic compound used as a neutralizing agent, for example,

Ammonia, triethylamine, triisopropylamine, tributylamine, triethanolamine, N-methyldiethanolamine, N-phenyldiethanolamine, monoethanolamine, dimethylethanolamine, diethylethanolamine, morpholine, N-methylmorpholine, 2-amino-2- Examples include amines such as ethyl-1-propanol and pyridine, inorganic alkalis such as sodium hydroxide and potassium hydroxide, and ammonia and trialkylamine are preferable.

<Water-based ink composition>
The aqueous ink composition of the present invention is an ink composition comprising the acrylic / urethane composite resin, a pigment, a hydrophilic solvent, and water.

The acrylic / urethane composite resin is preferably used in an amount of 5 to 40% by weight, more preferably 10 to 30% by weight, in terms of solid content in 100% by weight of the water-based ink composition. If the addition amount of the composite resin is less than 5% by weight in terms of solid content, the dispersion stability of the ink, the storage stability, and the physical properties of the coating film (substrate adhesion, water friction resistance) may be deteriorated. On the other hand, when the composite resin exceeds 40% by weight in terms of solid content, the viscosity of the ink composition is remarkably increased, resulting in poor drying in the coating film, and physical properties of the coating film (substrate adhesion, water friction resistance, water blocking resistance). Property) may decrease.

  The acrylic / urethane composite resin can be used as a pigment dispersant for preparing a pigment dispersion. Moreover, it can also be used by further adding to a pigment dispersion as a binder component.

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.

  When organic pigments are exemplified by color index (CI) numbers, C.I. I. Pigment Yellow 12, 13, 14, 17, 20, 24, 74, 83, 8893, 109, 110, 117, 120, 125, 128, 129, 137, 138, 139, 147, 148, 150, 151, 153 154, 155, 166, 168, 180, 185, C.I. I. Pigment orange 16, 36, 43, 51, 55, 59, 61, C.I. I. Pigment Red 9, 48, 49, 52, 53, 57, 97, 122, 123, 149, 168, 177, 180, 192, 202, 206, 215, 216, 217, 220, 223, 224, 226, 227, 228, 238, 240, C.I. I. Pigment violet 19, 23, 29, 30, 37, 40, 50, C.I. I. Pigment blue 15, 15: 1, 15: 3, 15: 4, 15: 6, 22, 60, 64, C.I. I. Pigment green 7, 36, C.I. I. Pigment brown 23, 25, 26, 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 organic pigments such as yellow, magenta, cyan and black are preferably blended at a ratio of 5 to 30% by weight in 100% by weight of the water-based ink composition. Moreover, in the case of white titanium oxide, it is preferable to mix | blend normally in the ratio of 10 to 60 weight%.

Examples of the hydrophilic solvent include ethanol, 1-propanol (n-propanol), 2-propanol (isopropyl alcohol), 1-butanol, 2-methyl-1-propanol, 2-butanol, and 2-methyl-2-propanol. Monohydric alcohol solvents;
Ethylene glycol, 1,3-propanediol, propylene glycol, 1,2-butanediol, 1,4-butanediol, pentylene glycol, 1,2-hexanediol, 1,6-hexanediol, diethylene glycol, triethylene glycol Glycol solvents such as tetraethylene glycol;
Ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, triethylene glycol monoethyl ether, ethylene glycol monoethyl ether, diethylene glycol monoethyl ether, triethylene glycol monoethyl ether, ethylene glycol monoisopropyl ether, diethylene glycol monoisopropyl ether, triethylene glycol monoisopropyl Ether, ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, triethylene glycol monobutyl ether, ethylene glycol monoisobutyl ether, diethylene glycol monoisobutyl ether, triethylene glycol monoisobutyl ether, ethylene glycol monohexyl ether , Diethylene glycol monohexyl ether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, glycol ethers such as tripropylene glycol monomethyl ether solvent;
Lactam solvents such as N-methyl-2-pyrrolidone, N-hydroxyethyl-2-pyrrolidone, 2-pyrrolidone, and ε-caprolactam;
Examples include amide solvents such as formamide, N-methylformamide, N, N-dimethylformamide, Idemitsu Examide M-100, and Ecamide B-100, and monovalent alcohol solvents and glycol ether solvents are preferred.
These can be used alone or in combination of two or more.

In addition, the water-based ink composition of the present invention can be used in combination with a resin fine particle dispersion containing a carbodiimide group for the purpose of further improving water friction resistance and water blocking resistance. Since the composite resin of the present invention has a hydrophobic urethane skeleton, it has good compatibility with the carbodiimide group-containing resin fine particle dispersion during film formation, and an ink in which the carboxyl group and carbodiimide group of the composite resin have reacted. The coating film is further improved in water friction resistance.

As the carbodiimide group-containing resin fine particle dispersion, polycarbodiimide produced from dicyclohexylmethane-4,4′-diisocyanate or 1,3-bis (2-isocyanato-2-propyl) benzene is modified with water dispersion. Examples include the body. Examples of commercially available products include Nisshinbo Co., Ltd., Carbodilite E-02, E-03A, SV-02, V-02, V-02-L2, V-04, E-04, and the like.

The addition amount of the carbodiimide group-containing resin fine particle dispersion is preferably about 0.5 to 10% by weight in terms of solid content in 100% by weight of the water-based ink composition. When the addition amount is less than 0.5% by weight, the effect of improving the water friction resistance and water blocking resistance may not be confirmed because the addition amount is small. On the other hand, if it exceeds 10% by weight, the dispersion stability and storage stability of the ink may be deteriorated.

In the aqueous ink composition of the present invention, a commercially available wax fine particle dispersion can be used for the purpose of improving the friction resistance of the coating film. Examples of the wax resin fine particle dispersion include Chemipearl W100, W200, W300, W310, W306, W400, W401, W4005, W410, W500, WF640, W700, W800, W900, W950, WH201, and WP100 manufactured by Mitsui Chemicals, Inc. Is mentioned.

The amount of the wax fine particle dispersion added is about 1 to 5% by weight in terms of solid content in 100% by weight of the water-based ink composition in consideration of the balance between the improvement of the friction resistance in the physical properties of the coating film and the adverse effect on the hue. Is preferred.

The water-based ink composition of the present invention can use various surface conditioners for the purpose of adjusting the leveling property to the substrate. As the surface conditioner, for example, Surfinol 104E, 104H, 104A, 104PA, 104PG-50, 104S, 420, 440, 465, 485, SE, SE-F, PSA-336, 61, 2502, manufactured by Nissin Chemical Co., Ltd. , DYNOL 604, 607, BYK-381, 3441, 302, 307, 325, 331, 333, 342, 345, 346, 347, 348, 349, 378, 3455, etc., manufactured by BYK Chemie.

The addition amount of the surface modifier is preferably about 0 to 1.0% by weight in terms of solid content in 100% by weight of the water-based ink composition in consideration of the balance of adverse effects on the coating film properties.

  In addition, the water-based ink composition of the present invention can use a hydrazide-based additive for the purpose of improving adhesion to a base material, room temperature crosslinking of a resin (in the case of containing a keto group), and the like. Examples of the hydrazide additive include adipic acid hydrazide.

The water-based ink composition of the present invention is a non-polar film substrate such as a polyethylene terephthalate or a polyolefin such as polypropylene, even under low temperature drying conditions. And water blocking resistance. Therefore, it is very useful in the field of various inks such as flexo, gravure and ink jet, which have recently been strongly demanded to be water-based and extend the base material. Moreover, it can be used for the purpose of improving the physical properties of the coating film even on conventional substrates such as permeable substrates such as fine paper, art paper, and coated paper.

Although it is a drying process of a water-based ink composition, any temperature can be applied as long as it does not adversely affect the substrate. In flexographic printing, gravure printing, and inkjet printing, it is common to process at a low temperature of 40 to 100 ° C. for 1 to 200 seconds.

  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. Unless otherwise specified, “parts” in the examples represents “parts by weight” and “%” represents “% by weight”.

<Manufacture of both terminal mercapto group-containing urethane urea resins>
[Production Example 1]
In a reaction vessel equipped with a stirrer, a thermometer, and a refluxer, 51.5 parts of polytetramethylene glycol (PTG-2000 functional group number 2, OH number 57.0 mgKOH / g, manufactured by Hodogaya Chemical Co., Ltd.) as polyol (A) , 34.9 parts of polyester polyol (Kuraray P-2010 functional group number 2, OH value 56.0 mgKOH / g), 13.6 parts of isophorone diisocyanate as polyisocyanate (B), and stirred at 80 ° C. under a nitrogen atmosphere The temperature was raised to. Thereto, 0.02 part of titanium diisopropoxybiz (ethyl acetoacetate) was added, and the temperature was raised to 110 ° C. and reacted for 5 hours, and then the temperature was lowered to 80 ° C. At this time, the urethane prepolymer (C-1) produced had a weight average molecular weight of 12700 and a residual isocyanate content of 0.35 mmol / g. Subsequently, 40.0 parts of methyl isobutyl ketone and 2.3 parts of 2-aminoethanethiol as compound (D) were added and reacted at 75 ° C. for 2 hours. The end point of the reaction was confirmed by the disappearance of the peak derived from the isocyanate group (around 2270 cm ⁻¹ ) by FT-IR. Further, methyl isobutyl ketone was added to adjust the final solid content of the resin solution to 70.0%. The acid value of the obtained both-end mercapto group-containing urethane urea resin (C-2) was 0 mgKOH / g, and the weight average molecular weight was 19,600.

[Acid value]
Number of milligrams of potassium hydroxide required to neutralize acidic components contained in 1 g of resin. The dried resin was calculated by performing potentiometric titration with a potassium hydroxide / ethanol solution according to the method described in JIS K2501. For the titration, an automatic titrator COM-1600 manufactured by Hiranuma Sangyo Co., Ltd. was used.

[Weight average molecular weight]
The weight average molecular weight here is a value in terms of polystyrene by GPC (gel permeation chromatography) measurement. The dried resin was dissolved in tetrahydrofuran to prepare a 0.1% solution, and the weight average molecular weight was measured using the following apparatus and measurement conditions.
Apparatus: HLC-8320-GPC system (manufactured by Tosoh Corporation)
Column; TSKgel-SuperMultiporeHZ-M0021488
4.6 mm I.D. x 15 cm x 3 (molecular weight measurement range 2,000 to about 2 million)
Elution solvent; Tetrahydrofuran standard substance; Polystyrene (Tosoh Corporation)
Flow rate: 0.6 mL / min, sample solution usage: 10 μL, column temperature: 40 ° C.

[Quantification of isocyanate groups]
0.5 g of urethane prepolymer was sampled, 10 mL of a 0.2 mol / L (liter) dibutylamine-toluene solution and 25 mL of toluene were added, and the mixture was stirred for 10 minutes. Thereafter, 40 mL of isopropyl alcohol was added, and unconsumed dibutylamine was titrated with a 0.1 mol / L hydrochloric acid ethanol solution. For the titration, an automatic titrator COM-1600 manufactured by Hiranuma Sangyo Co., Ltd. was used. From the difference between the titration value and the blank experiment, the amount (mmol / g) of isocyanate groups remaining in the resin was calculated.

[Production Examples 2 to 23]
With the formulation shown in Table 1, a urethane prepolymer (C-1) was synthesized by the same method as in Production Example 1, and the weight average molecular weight and the residual isocyanate group amount were measured. Furthermore, it was made to react with the compound (D) represented by General formula (1), and the both-end mercapto group containing urethane urea resin (C-2) was obtained.
Instead of the compound (D) represented by the general formula (1), in Production Example 22, thioglycol was reacted, and in Production Example 23, 1,2-ethanedithiol was reacted. After the reaction, the same operation as in Production Example 1 was performed to adjust the final solid content of the resin solution to 70.0%. The acid value and the weight average molecular weight were also measured in the same manner for the obtained both-end mercapto group-containing urethane urea resin.

The abbreviations in Table 1 are shown below.
<Polyol>
-Uniol D-2000; Polypropylene glycol manufactured by NOF Corporation (functional group number 2, OH group value 56.0, molecular weight 2000)
・ PEG # 2000; NOF polyethylene glycol (functional group number 2, OH group value 56.0, molecular weight 2000)
PTG-2000SN; polytetramethylene glycol (functional group number 2, OH group value 57.0, molecular weight 2000) manufactured by Hodogaya Chemical Co., Ltd.
PTG-3000SN: Hodogaya Chemical Co., Ltd. polytetramethylene glycol (functional group number 2, OH group value 37.0, molecular weight 3000)
P-2010: Kuraray MPD / AA polyester polyol (functional number 2, OH value 56.0, molecular weight 2000)
P-2011: MPD / AA / TPA polyester polyol manufactured by Kuraray Co., Ltd. (number of functional groups 2, OH value 55.0, molecular weight 2000)
HS2P-203S; 1,3PD / SA polyester polyol manufactured by Toyokuni Oil Co., Ltd. (functional group number 2, OH number 54.6, molecular weight 2000)
HS2N-220S: Toyokuni Oil SA SA iND / SAA polyester polyol (functional group number 2, OH number 56.0, molecular weight 2000)
・ Priprast-3199; hydrogenated dimer acid polyester polyol manufactured by Croda (2 functional groups, OH value 50.0, molecular weight 2000)
-T5652: Asahi Kasei's polycarbonate polyol (functional group number 2, OH value 56.0, molecular weight 2000)
T6002: Polycarbonate polyol manufactured by Asahi Kasei Co., Ltd. (functional group number 2, OH value 56.0, molecular weight 2000)
GI-1000; Nippon Soda Co., Ltd. hydrogenated polybutadiene-based polyol (number of functional groups 2, OH value 64.0, molecule 1000)
・ Poly-bd R-45HT: Liquid polybutadiene polyol manufactured by Idemitsu Co., Ltd. (functional group number 2, OH number 46.6, molecular weight 2800)
HS 2G-160R: Castor oil polyol manufactured by Toyokuni Oil Co., Ltd. (number of functional groups 2, OH number 120, molecular weight 930)

<Manufacture of aqueous acrylic / urethane composite resin>
[Example 1]
In a reaction vessel equipped with a stirrer, a thermometer, a dropping funnel, and a refluxer, 142.9 parts of a urethane urea resin solution containing both terminal mercapto groups obtained in Production Example 1 (non-volatile component is 100.0 parts), methyl methacrylate 50.0 parts, 35.0 parts of n-butyl methacrylate, 15.0 parts of methacrylic acid and 37.0 parts of n-propanol were added, and the temperature was raised to 75 ° C. with stirring in a nitrogen atmosphere. In a dropping funnel, 20.0 parts of methyl isobutyl ketone and 0.35 part of 2,2′-azobis (2,4-dimethylvaleronitrile) as an initiator were charged and dropped into the reaction vessel over 5 hours. The reaction was performed at 75 ° C. for 8 hours to complete the graft reaction of the acrylic resin portion. After the reaction, 450.0 parts of ion-exchanged water and 7.9 parts of 25% ammonia water were added and neutralized, and then the solvent was removed at 90 ° C. for 4 hours to obtain an aqueous dispersion of an aqueous acrylic / urethane composite resin. It was. The final solid content of the composite resin water dispersion was adjusted to 25.0% with ion-exchanged water. The resulting aqueous acrylic / urethane composite resin had an acid value of 48.9 mgKOH / g and a molecular weight of 39800. The acid value and the weight average molecular weight were measured in the same manner as for the urethane urea resin containing both terminal mercapto groups. Further, the acid value of the acrylic part was calculated from the acid value of the urethane urea resin containing both terminal mercapto groups, the acid value of the composite resin, and the acrylic / urethane weight ratio. As a result, the acid value of the acrylic part was 97.7 mgKOH / g.

[Examples 2-32 and Comparative Examples 1-7]
An aqueous acrylic / urethane composite resin was synthesized in the same manner as in Example 1 with the blending composition shown in Tables 2-4. In Example 28, the initiator amount was changed to 0.60 parts, and in Example 29, 0.09 parts. After the reaction, in the same manner as in Example 1, water treatment and solvent removal treatment were carried out to obtain an aqueous dispersion of the desired aqueous acrylic / urethane resin. The final solid content of the obtained aqueous dispersion of composite resin was adjusted to 25.0%. For the obtained resin, the acid value and the weight average molecular weight were measured in the same manner as in Example 1, and the acid value of the acrylic moiety was also calculated.

Abbreviations in Table 2 are shown below.
PME-400: NOF's methoxypolyethylene glycol methacrylate (ethylene oxide addition mole number 9)

<Production of water-based ink composition>

<Manufacture of white ink composition>
[Example 33] Titanium oxide inorganic pigment [Taipeku CR80, manufactured by Ishihara Sangyo Co., Ltd.] 40.5 parts, 13.5 parts of an aqueous dispersion of urethane / acrylic resin of Example 1 (solid content 25%), ion-exchanged water 11 0.0 part, 0.2 parts of a surface conditioner [Surfinol 420 manufactured by Nissin Chemical Industry Co., Ltd.], 0.3 part of adipic acid hydrazide, and 2.0 parts of n-propanol were dispersed in a paint conditioner for 2 hours, and concentrated white. A pigment dispersion was obtained. In this concentrated white pigment dispersion, 29.0 parts of the aqueous dispersion of the aqueous acrylic / urethane composite resin obtained in Example 1, 3.0 parts of Chemipearl W500 (solid content 40.0%) manufactured by Mitsui Chemicals, diethylene glycol After adding 0.5 part of monoethyl ether, the mixture was kneaded to obtain the desired white aqueous ink composition.

[Examples 34 to 66 and Comparative Examples 8 to 14]
With the formulation shown in Tables 5-7, it was prepared in the same manner as in Example 33 to obtain a white aqueous ink composition.

<Manufacture of indigo ink composition>
[Example 67]
Phthalocyanine-based organic pigment [Lionol Blue FG7330, manufactured by Toyocolor Co., Ltd.] 17.2 parts, urethane / acrylic resin aqueous dispersion of Example 1 (solid content 25.0%) 11.6 parts, ion-exchanged water 18.7 parts The surface conditioner [Surfinol 420 manufactured by Nissin Chemical Industry Co., Ltd.] 0.2 parts, adipic acid hydrazide 0.2 parts, and n-propanol 2.7 parts were dispersed in a paint conditioner for 2 hours to obtain a concentrated indigo pigment dispersion. Obtained. Furthermore, 39.5 parts of the urethane / acrylic resin aqueous dispersion of Example 1, 4.5 parts of Chemipearl W500 (solid content 40.0%) manufactured by Mitsui Chemicals, 0.5 part of diethylene glycol monoethyl ether as a hydrophilic solvent, After adding 5.0 parts of ion-exchanged water, the mixture was kneaded to obtain an indigo water-based ink composition.

[Examples 68 to 100 and Comparative Examples 15 to 21]
The composition shown in Tables 8 to 10 was prepared in the same manner as in Example 67 to obtain an indigo water-based ink composition.

<Evaluation of water-based ink composition>
About the above-mentioned water-based ink composition, dispersion stability and storage stability were evaluated. Furthermore, the water-based ink composition was applied to PET and an OPP substrate (treated / untreated surface) using a flexoproof 100 (anilox roller 80 lines / cm). After coating, the substrate was heat-treated in an oven at 60 ° C. for 1 minute to obtain a printed film for evaluation. Using this, substrate adhesion, water friction resistance, scratch resistance, water blocking resistance, and odor test were carried out. The results are shown in Tables 5-10.

[Dispersion stability]
About the water-based ink composition, the particle size distribution was measured by Microtrack MT-3000 (laser diffraction type particle size distribution measuring device) manufactured by Nikkiso Co., Ltd. The sample solution was diluted by sample loading so that the DV value (concentration index using the total scattered light from the sample received by the detector) was within an appropriate range. The evaluation criteria are as follows. (The smaller the particle size distribution, the better and the practical level is better than ○)
[In case of white ink composition]
A: Median diameter d50 is less than 500 nm; Median diameter d50 is 500 nm or more and less than 1000 nm; Δ; Median diameter d50 is 1000 nm or more and less than 1500 nm; X; Median diameter d50 is 1500 nm or more in the case of]
A: Median diameter d50 is less than 300 nm.
◯: Median diameter d50 is 300 nm or more and less than 500 nm Δ: Median diameter d50 is 500 nm or more and less than 1000 nm ×: Median diameter d50 is 1000 nm or more

[Storage stability]
The aqueous ink composition was evaluated for changes in viscosity over time under conditions of 40 ° C. and 1 week. The viscosity was measured using a Zahn cup (No. 4).
The evaluation criteria are as follows. (The smaller the clay change, the better and the practical level is better than ○)
A: Change in the viscosity of the ink is less than ± 10% B: Change in the viscosity of the ink is ± 10% or more and less than ± 15% Δ: Change in the viscosity of the ink is ± 15% or more and less than ± 20% × ; The viscosity change of the ink is ± 20% or more.

[Base material adhesion]
Cellophane tape (18 mm width manufactured by Nichiban Co., Ltd.) was applied to the printed film, and a peel test was conducted in the vertical direction, and the substrate adhesion was evaluated from the ratio of the area where the ink was peeled off.
The evaluation criteria are as follows. (Practical level is more than ○)
◎: No ink peeling ○: Some ink peeling (less than 10%)
Δ: Ink peeling (10% or more, less than 50%)
×: Ink peeling is considerable (50% or more)

[Water friction resistance]
The printed film was immersed in water for 1 minute. After dipping, using Kanakin (JIS L 0803) as a friction element, the surface of the coated film with water was reciprocated 500 times with a load of 500 g using a Gakushin tester (manufactured by Tester Sangyo Co., Ltd.). The water friction resistance was evaluated from the ratio of the area where the ink was peeled off. The evaluation criteria are as follows. (Practical level is more than ○)
◎: No ink peeling ○: Ink peeling slightly (less than 5%)
Δ: Ink peeling (5% or more, less than 30%)
×: Ink peeling is considerable (30% or more)

[Scratch resistance]
About each printed matter coating film, it rubbed 10 times with the nail | claw and observed the ease of being damaged of the coating surface. The evaluation criteria are as follows. (Practical level is ○)
◯: All the printed film was not damaged. ×: Either of the printed films was damaged.

[Water blocking resistance]
For each printed film, one drop of water was dropped on the coated surface, the untreated surface of the same film base material was superposed, and a load of 1 kg / cm ² was applied, and left in a constant temperature and humidity chamber at 40 ° C. for 24 hours. Then, the coating film for evaluation was taken out and the presence or absence of show-through was confirmed. The water blocking resistance was evaluated from the ratio of the offset area.
The evaluation criteria are as follows. (Practical level is more than ○ △)
◎: No sound when peeling, no set-off ○: Sound when peeling, but no set-off Δ: Ink is slightly show-through on back side (less than 1%)
×: The ink is show-through on the back (1% or more)

[Odor test]
A printed film of 40 cm × 20 cm was put into a 500 ml bottle, and a sealed one was created by closing the lid. After heating at 80 ° C. for 2 hours, the lid was opened with 10 panelists to confirm the odor. The evaluation criteria are as follows. (The lower the odor, the better the practical level is 〇)
A: All 10 people felt no odor.
○: 1 or 2 out of 10 felt odor △; 3 or 4 out of 10 felt odor ×; 5 or more out of 10 felt odor

As shown in Tables 5, 6, 8, and 9, white aqueous ink compositions (Examples 33 to 66) and indigo water-based ink compositions (Examples) using the aqueous urethane / acrylic composite resins of Examples 1 to 32. 67 to 100) are excellent in pigment dispersibility and storage stability of ink, and with regard to printed coatings, adhesion to treated and untreated film substrates, water rub resistance, scratch resistance, water blocking resistance, low odor It was found to be excellent and practical. In particular, the excellent dispersion stability of inorganic pigments, adhesion to non-corona-treated nonpolar film substrates, water rub resistance, and low odor are expected in the future for water-based ink ink expansion and substrate expansion. It can be expected to be very useful.
On the other hand, the white aqueous ink compositions (Comparative Examples 8 to 14) and the indigo water-based ink compositions (Comparative Examples 15 to 21) using the aqueous ink resins of Comparative Examples 1 to 7 are shown in Tables 7 and 10. In addition, there are problems with ink pigment dispersibility, storage stability, film substrate adhesion of printed film, water rub resistance, scratch resistance, and odor of printed material, and does not meet the practical level. As a result.

Claims (6)

Acid value less than 5 mgKOH / g obtained by reacting the compound (D) represented by the general formula (1) with the urethane prepolymer (C-1) obtained by reacting the polyol (A) and the polyisocyanate (B). A polymerized ethylenically unsaturated monomer (E) containing a methacryloyl group-containing monomer , using the both-end mercapto group-containing urethane urea resin (C-2) as a chain transfer agent ,
The ethylenically unsaturated monomer (E) an acid value of the acrylic resin moiety obtained by polymerizing a is a 30 to 300 mg KOH / g Der Ru aqueous ink for acrylic urethane composite resin,
Acrylic / urethane composite for water-based inks obtained by reacting ethylenically unsaturated monomer (E) in the range of 30 to 180 parts by weight per 100 parts by weight of both end mercapto group-containing urethane urea resin (C-2) resin.
General formula (1)

(In general formula (1), X represents hydrogen or an alkyl group. R represents at least one divalent group selected from the group consisting of an alkylene group, an arylene group, and an alkylene oxide group.) The compound (D) represented by the general formula (1) is reacted in the range of 0.60 to 0.90 mol with respect to 1 mol of the isocyanate group of the urethane prepolymer (C-1). Acrylic / urethane composite resin for water-based ink as described. The polyol (A) is selected from the group consisting of polyether polyol (a-1), polyester polyol (a-2), polycarbonate polyol (a-3), polyolefin-based polyol (a-4), and castor oil polyol. The acrylic / urethane composite resin for water-based ink according to claim 1 or 2, comprising at least one kind. The acrylic (1) for water-based ink according to any one of claims 1 to 3, wherein the polyol (A) comprises a polyether polyol (a-1) and / or a polycarbonate polyol (a-3) and a polyester polyol (a-2). Urethane composite resin. A water-based ink composition comprising the acrylic urethane resin for water-based inks according to any one of claims 1 to 4 , a pigment, a hydrophilic solvent, and water. Acid value less than 5 mgKOH / g obtained by reacting the compound (D) represented by the general formula (1) with the urethane prepolymer (C-1) obtained by reacting the polyol (A) and the polyisocyanate (B). A polymerized ethylenically unsaturated monomer (E) containing a methacryloyl group-containing monomer , using the both-end mercapto group-containing urethane urea resin (C-2) as a chain transfer agent ,
The ethylenically unsaturated monomer (E) polymerizing the acid value of the acrylic resin moiety comprising a can, a process for the preparation of 30 to 300 mg KOH / g Der Ru aqueous ink for acrylic urethane composite resin,
An acrylic / urethane composite resin for water-based inks in which an ethylenically unsaturated monomer (E) is reacted in an amount of 30 to 180 parts by weight with respect to 100 parts by weight of a both-end mercapto group-containing urethane urea resin (C-2). Production method.
General formula (1)

(In general formula (1), X represents hydrogen or an alkyl group. R represents at least one divalent group selected from the group consisting of an alkylene group, an arylene group, and an alkylene oxide group.)