JPH0718212A - Water-based ink composition - Google Patents

Abstract

PURPOSE:To provide the composition excellent in hardenability and printability. CONSTITUTION:The composition contains a keto- or aldo-containing acrylic copolymer emulsion, a water-soluble resin obtained by neutralizing a keto- or aldo-containing resin having an acid value of 30 to 400, and a hydrazine derivative having at least two hydrazine residue in the molecule. The composition has good viscosity stability during storage and gives printed matter excellent in various physical properties (such as alcohol resistance, alkali resistance and water resistance).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention is used for printing on substrates such as plastic film, metal, paper and glass.
The present invention relates to a water-based ink composition having excellent storage stability and chemical resistance.

[0002]

2. Description of the Related Art In recent years, in the printing field, prevention of air pollution,
Due to improvement of working environment and awareness of disaster prevention, the shift from solvent-based printing ink to water-based printing ink has been promoted. Conventionally, water-based printing inks have various resin components such as shellac, rosin maleic acid-based water-soluble resin, acrylic resin, styrene-acrylic resin, and styrene-maleic acid resin alone or appropriately blended as the resin component. The composition is used.

However, these resins have a carboxyl group or an amino group in the resin skeleton in order to be dissolved or dispersed in water, and the printed matter obtained from the ink containing these resins is resistant to chemicals such as alkali and alcohol. The sex is extremely insufficient. Therefore, in the field where the printed matter requires chemical resistance, the printed matter is laminated with a plastic film to protect the surface of the printed matter or the solvent type ink is used when the printing ink is exposed on the surface. Is.

Further, in the case of imparting chemical resistance, a method of imparting resistance by incorporating an aziridine compound or a carbodiimide compound as a crosslinking agent into an aqueous printing ink has been proposed. (Refer to ICI's "CX-100" and "XL-29SE" catalogs.) However, if these aqueous printing inks are used, a printed matter having a certain degree of chemical resistance can be obtained, but a crosslinking agent is added immediately before printing. There was a problem in workability and economy such as being liquid type and the pot life being short due to hydrolysis of the cross-linking agent in a relatively short time.

Further, as a curable aqueous resin composition for coating, an aqueous dispersion containing a hydrazine derivative and a carbonyl group-containing copolymer such as an aldo group or a keto group is known. For example, Japanese Patent Application Laid-Open No. 54-110248 discloses an aqueous dispersion of a carbonyl group-containing copolymer containing a hydrazine derivative, and a composition using a carbonyl group-containing copolymer, an organic hydrazine derivative, and a heavy metal ion. Stated.

However, the aqueous dispersions of these resins are emulsions obtained in the presence of surfactants. Although such a type of aqueous dispersion is likely to form a film having good physical properties after film formation, it has a problem of poor stability, pigment dispersibility, and printability. In addition, when a general water-soluble resin such as styrene-maleic acid or styrene-acrylic acid is mixed with the above emulsion, printability can be improved, but compatibility with chemical resistance such as alkali resistance and alcohol resistance of printed matter can be achieved. Was difficult.

[0007]

DISCLOSURE OF THE INVENTION As a result of intensive studies to improve the above-mentioned various drawbacks, the present inventors have found that an acrylic copolymer emulsion having a keto group or an aldo group, a specific water-soluble resin and It was found that a water-based ink composition containing a hydrazine derivative having two or more hydrazine residues in the molecule is excellent in curability and printability, and can provide a printed matter excellent in alcohol resistance, alkali resistance and water resistance, The present invention has been completed.

[0008]

Means for Solving the Problems The present invention comprises neutralizing an acrylic copolymer emulsion (A) having a keto group or an aldo group and a resin having an acid value of 30 to 400 having a keto group or an aldo group. Provided is an aqueous ink composition containing a water-soluble resin (B) and a hydrazine derivative (C) having two or more hydrazine residues in the molecule.

Examples of the acrylic copolymer emulsion (A) having a keto group or an aldo group include Acronal YJ-2720D, Acronal YJ-2741D, Acronal YJ-2743D, Acronal YJ-2770D, Acronal YJ manufactured by Yuka Badishe. -2772D, Acronis YJ-2773D, etc.

The water-soluble resin (B) is obtained by neutralizing a resin having an acid value of 30 to 400 having a keto group or an aldo group. When the acid value of the resin having a keto group or an aldo group is less than 30, the resin obtained by the neutralization operation described below has poor water solubility,
When processed into printing ink, the fluidity of the ink is poor and the printability is insufficient. If the acid value exceeds 400,
A water-soluble resin obtained by neutralizing the resin lowers the water resistance of the obtained print and is not preferable.

The resin having a keto group or an aldo group includes a carboxyl group-containing ethylenically unsaturated monomer, a keto group or an aldo group-containing ethylenically unsaturated monomer, styrenes such as styrene and methylstyrene, and ( Methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, propyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, stearyl (meth) acrylate, methoxyethyl (meth) acrylate, Ethoxyethyl (meth) acrylate, propoxyethyl (meth) acrylate, methoxyethoxyethyl (meth) acrylate, ethoxyethoxyethyl (meth) acrylate, butoxyethoxyethyl (meth) acrylate, etc.
18 aliphatic monohydric alcohol, C3-C30 ethylene glycol monoalkyl ether or C3-C30 diethylene glycol monoalkyl ether and (meth)
It is obtained by copolymerizing one or more monomers such as an ester with acrylic acid, vinyl acetate, maleic acid ester and acrylonitrile.

Examples of the carboxyl group-containing ethylenically unsaturated monomer include polymerizable unsaturated carboxylic acids such as (meth) acrylic acid, itaconic acid, maleic acid, fumaric acid and crotonic acid, or anhydrides thereof. Examples of the ethylenically unsaturated monomer containing a keto group or an aldo group include acrolein, diacetone (meth) acrylamide, formyl styrene, vinyl methyl ketone, vinyl ethyl ketone, vinyl isobutyl ketone, (meth) acryloxymethyl propanal, diacetone ( Examples thereof include N-substituted (meth) acrylic monomers such as (meth) acrylate, acetonyl (meth) acrylate, N-methylol (meth) acrylamide, and N-butoxymethyl (meth) acrylamide.

The composition of the monomer is such that the keto group- or aldo group-containing ethylenically unsaturated monomer is 1 to 50% by weight, preferably 1 to 30% by weight, based on the total amount of the monomers. The acid value of is properly selected so as to fall within the range of 30 to 400. 1% by weight of ethylenically unsaturated monomer containing keto group or aldo group
If less than 50% by weight of the resulting coating aqueous resin composition cross-linking density tends to be poor solvent resistance and water resistance of the coating after drying, the coating aqueous resin composition obtained above 50% by weight Storage stability tends to be slightly lower. The molecular weight of the obtained resin is preferably 3000 to 60,000.

The resin having a carboxyl group and a keto group or an aldo group obtained as described above has ammonia or triethylamine in the reaction system after completion of the polymerization reaction.
Water-soluble resin (B) is obtained by adding and neutralizing organic amines such as trimethylamine, dimethylaminoethanol and monoethanolamine. The amount of ammonia added is approximately 70-120 for the neutralization ratio of the carboxyl groups in the resin.
The range of% is preferable. If the neutralization rate is too low, the fluidity of the resulting aqueous ink composition will be reduced, which is not preferable.

The ratio of the acrylic copolymer emulsion (A) having a keto group or an aldo group to the water-soluble resin (B) obtained by neutralizing a resin having an acid value of 30 to 400 having a keto group or an aldo group is fixed. Mold component weight ratio 10/90 to 99.9 / 0.1, preferably 30 /
70-80 / 20. If the content of the water-soluble resin (B) is low, the printability, especially the transferability from the plate to the substrate is poor, and if the content of the acrylic copolymer emulsion (A) is low, Poor chemical resistance.

Examples of the hydrazine derivative (C) having two or more hydrazine residues include fatty acid dihydrazide such as oxalic acid dihydrazide, malonic acid dihydrazide, succinic acid dihydrazide, glutaric acid dihydrazide, adipic acid dihydrazide, sebacic acid dihydrazide, and carbonic acid. Polyhydrazides, aliphatics, alicyclics, aromatic bissemicarbazides, aromatic dicarboxylic acid dihydrazides, polyacrylic acid polyhydrazides, trihydrazides, aromatic hydrocarbon dihydrazides, hydrazine-pyridine derivatives and maleic acid dihydrazides, fumaric acid dihydrazides And dihydrazides of unsaturated dicarboxylic acids.

The hydrazine derivative (C) having two or more hydrazine residues is used in a ratio of 0.1 to 5, preferably 0.2 to 3, hydrazine residues to one aldo group or keto group. When the number of hydrazine residues is less than 0.1, the crosslink density of the obtained aqueous ink composition becomes small, and the solvent resistance and water resistance of the printed matter after drying are slightly inferior, and when it exceeds 5, the storage stability of the obtained aqueous ink composition is high. Sex is slightly lower.

The aqueous ink composition of the present invention contains phthalocyanine pigments, soluble azo pigments, insoluble azo pigments, naphthol pigments, titanium oxide, carbon black, calcium carbonate, precipitated barium sulfate, clay and other organic, inorganic and physical substances. Pigments can be used as colorants.

Further, water or a water-soluble organic solvent can be used in the water-based ink composition of the present invention. Examples of the organic solvent include alcohols such as methyl alcohol, ethyl alcohol, isopropyl alcohol, and N-propyl alcohol, glycols such as ethylene glycol and propylene glycol, methyl cellosolve, ethyl cellosolve, butyl cellosolve, propylene glycol, propylene glycol monomethyl ether, Examples thereof include glycol ethers such as diethylene glycol monomethyl ether, diethylene glycol monoethyl ether and diethylene glycol monobutyl ether.
The weight ratio of water to organic solvent is preferably 100/0 to 40/60.

In the aqueous ink composition of the present invention, if necessary, bases such as ammonia, triethylamine, aminomethylpropanol, monoethanolamine, diethylaminoethanol, sodium hydroxide and potassium hydroxide, fine powder silica and the like can be used. Thixotropic agents, colloidal silica, sol such as alumina sol, polyvinylpyrrolidone, polyvinyl alcohol, shellac, water-soluble polyester resin, water-soluble or water-dispersible resin such as water-soluble or water-dispersible polyurethane resin or polyamide resin, polyethylene wax, Known dispersers and mixers containing pigment dispersants, defoamers, leveling agents, tackifying resins, preservatives, antifungal agents and the like. It is dispersed, mixed or kneaded by a kneader or the like.

The water-based ink composition of the present invention comprises an absorbent base material such as kraft paper, coated paper and corrugated board, aluminum foil, corona-treated polyethylene, corona-treated biaxially oriented polypropylene, corona-treated non-oriented polypropylene, corona-treated polyester, It is printed by a gravure printing machine, a flexo printing machine or the like on a printing material such as a corona-treated nylon or other film base material or a corona-treated extrusion laminated non-absorbent base material such as carton paper.

[0022]

EXAMPLES The present invention will now be described in more detail by way of examples. In the examples, "part" means "part by weight" and "%" means "% by weight". [Production Examples 1 to 4] 300 parts of ethyl alcohol was charged into a reaction vessel equipped with a stirrer, a thermometer, a dropping device, and a reflux condenser, and the temperature was raised to 78 ° C.
And 6 parts of azobisisobutyronitrile were added dropwise over 2 hours, and then reacted at 78 ° C. for 4 hours. Next, the ethyl alcohol was distilled off under reduced pressure, and 425 parts of a mixed solution of ammonia water containing a carboxyl group in the reaction product and an equivalent amount of ammonia and water / ethyl alcohol = 70/30 (weight ratio) was added. Group or aldo group containing resin aqueous solution (solid content 32%)
(a)-(d) were obtained. The acid values shown in Table 1 are those before neutralization of the aldo group- or keto group-containing resin.

[0023]

[Table 1]

[Example 1] LIONOL BLUE FG7330 ^{* 1} 10.0 parts Water-soluble resin (a) 30.0 parts Polyethylene wax 1.0 part Water 8.67 parts Isopropyl alcohol 5.0 parts Silicone antifoam 0 1 part Acronal YJ-2720D ^{* 2} 45.0 parts Adipic acid dihydrazide 0.23 parts ───────────── 100.0 parts * 1; Toyo Ink Mfg. Co., Ltd. indigo pigment * 2; Acrylic Copolymer Emulsion manufactured by Yuka Burdish Co., solid content 47% The above composition was mixed and dispersed in a sand mill to obtain a printing ink having a grind gauge of 30μ. This was diluted with a mixed solvent of water / isopropyl alcohol = 40/60, and the viscosity was adjusted to 25 seconds by Zahn Cup No. 3 manufactured by Ryukyu Co., Ltd. This ink was printed by flexographic printing on kraft paper laminated with corona-treated polyethylene.

[Example 2] REGAL 99 ^{* 1} 10.0 parts Water-soluble resin (b) 55.0 parts Polyethylene wax 1.0 part Water 12.74 parts Isopropyl alcohol 5.0 parts Mineral oil-based antifoaming agent 0 .5 parts Acronal YJ-2741D ^{* 3} 15.0 parts Succinic acid dihydrazide 0.76 parts ───────────── 100.0 parts * 1; CABOT ink pigment * 2; Oilification Acrylic Copolymer Emulsion manufactured by Badiche, solid content 55.5% Using the above composition, a printing ink was prepared in the same manner as in Example 1, and then printed on a corona-treated biaxially oriented polypropylene film by a flexographic printing method. .

Example 3 LIONOGEN VIOLET RL ^{* 1} 10.0 parts Water-soluble resin (c) 31.5 parts Polyethylene wax 1.0 parts Water 11.62 parts Isopropyl alcohol 5.0 parts Acetylene glycol antifoaming agent 0.5 parts Acronal YJ-2770D ^{* 2} 40.0 parts Adipic acid dihydrazide 0.38 parts ───────────── 100.0 parts * 1; Toyo Ink Mfg. Co., Ltd. * 2 Acrylic Copolymer Emulsion made by Yuka Birdish Co., solid content 47% Using the above composition, a printing ink was prepared in the same manner as in Example 1, and then a flexographic printing method was applied to a corona-treated biaxially stretched polyethylene film. Printed in.

Example 4 LIONOL BLUE FG7330 10.0 parts Water-soluble resin (b) 55.0 parts Polyethylene wax 1.0 part Water 12.3 parts Isopropyl alcohol 5.0 parts Silicone antifoam 0.1 Parts Acronal YJ-2720D 15.0 parts adipic dihydrazide 1.6 parts ───────────── 100.0 parts After mixing the above components, disperse with a sand mill and print with a grind gauge 30μ I got the ink. This was diluted with a mixed solvent of water / isopropyl alcohol = 40/60, and the viscosity was adjusted to 18 seconds with Zahn Cup No. 3 manufactured by Riaisha. This ink was printed by gravure printing on kraft paper laminated with corona-treated polyethylene.

Comparative Example 1 LIONOL BLUE FG7330 10.0 parts Acronal YJ-2770D 60.0 parts Polyethylene wax 1.0 parts Water 23.9 parts Isopropyl alcohol 5.0 parts Silicone antifoam 0.1 parts ─────────── 100.0 parts Using the above composition, after adjusting the printing ink in the same manner as in Example 4, printing was performed by gravure printing on kraft paper laminated with corona-treated polyethylene. did.

Comparative Example 2 LIONOL GREEN YS07 ^{* 1} 10.0 parts Acronal YJ-2741D 20.0 parts Water-soluble resin (d) 50.0 parts Polyethylene wax 1.0 parts Water 31.5 parts Isopropyl alcohol 5. 0 part Mineral oil type antifoaming agent 0.5 part Adipic acid dihydrazide 0.4 part ──────────── 100.0 parts * 1; Toyo Ink Mfg. Co., Ltd. grass pigment The above composition is used. After adjusting the printing ink in the same manner as in Example 4, a corona-treated polypropylene film was prepared.
It was printed by the gravure printing method.

Comparative Example 3 LIONOL BLUE FG7330 10.0 parts Jonkuryl 840 ^{* 1} 35.7 parts Water-soluble resin (d) 37.0 parts Polyethylene wax 1.0 parts Water 10.0 parts Isopropyl alcohol 5.0 Part Mineral oil type antifoaming agent 1.0 part Dihydrazide succinate 0.5 part ──────────── 100.0 parts * 1; Acrylic emulsion manufactured by Johnson Polymer Co., Ltd. After adjusting the printing ink in the same manner as in Example 1, printing was performed by flexographic printing on kraft paper laminated with corona-treated polyethylene.

The results of evaluating the appearance state, alcohol resistance, alkali resistance and water resistance of the prints obtained in Examples 1 to 4 and Comparative Examples 1 to 3 and the storage stability of the above water-based printing ink compositions were evaluated. The results are shown in Table 2. The evaluation method and evaluation criteria are as follows. Appearance of printed matter: The appearance of the printed matter was visually evaluated. Evaluation Criteria ○: There is density, and smoothness is good. Δ: The density and smoothness are slightly inferior. X: Concentration and smoothness are considerably poor.

Alcohol resistance: The coating film was rubbed with absorbent cotton containing 70% aqueous ethanol, and the degree of peeling of the printed matter was visually evaluated. Alkali resistance: A pH 11 sodium hydroxide aqueous solution was spotted on the printed matter, and after 10 minutes, wiped with absorbent cotton to observe changes in the printed matter. Water rub resistance: After immersing the printed matter in tap water at 20 ° C for 24 hours, rub it with a cotton cloth moistened with water under a load of 200 g 100 times using a Gakushin-type friction tester, and peel off the printed matter. Was visually evaluated.

Friction resistance: Using a Gakushin type friction tester, a printed matter was rubbed 500 times with a dry cotton cloth under a load of 500 g, and the degree of peeling of the printed matter was visually evaluated. Tape adhesiveness: Cellophane tape manufactured by Nichiban Co., Ltd. was adhered to the printed matter and then peeled off, and the degree of peeling of the printed matter was visually evaluated. Evaluation criteria for alcohol resistance to tape adhesion ◯: No change. Δ: There is some peeling on the printed matter. X: The printed matter is almost peeled off.

Storage stability: A change in viscosity when the aqueous printing ink composition was stored at 40 ° C. for 7 days was measured. Evaluation criteria ○: Viscosity increase is 1 to 1.5 times. B: Increase in viscosity is 1.5 to 2.5 times. X: Viscosity increase is 2.5 times or more.

[0035]

[Table 2]

[0036]

According to the present invention, a water-based ink composition having excellent physical properties (alcohol resistance, alkali resistance, water resistance, etc.) of printed matter and good storage viscosity stability can be obtained.

Claims (1)

[Claims] 1. Acrylic copolymer emulsion (A) having a keto group or an aldo group, a water-soluble resin (B) and a molecule obtained by neutralizing a resin having an acid value of 30 to 400 having a keto group or an aldo group. A water-based ink composition comprising a hydrazine derivative (C) having two or more hydrazine residues.