JP3052740B2 - Surface printing water-based printing ink composition for packaging and packaging material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface printing aqueous printing ink composition for packaging. More specifically, the present invention relates to a water-based printing ink composition which is gravure and flexographically printed on a surface-treated plastic film, particularly drawn polypropylene, undrawn polypropylene, polyethylene and aluminum, and has excellent adhesiveness, heat resistance and water resistance.

[0002]

2. Description of the Related Art In recent years, conversion to aqueous printing ink has been proposed as one means for solving problems such as pollution caused by solvent-type printing ink such as air pollution, occupational safety and health such as organic solvent poisoning, and danger of flammable explosion. Have been. In fact, water-based printing inks have been widely used for printing on general packaging paper, paper containers such as cardboard, and the like. However, in the field of printing on non-permeable plastic film base materials mainly for packaging materials, aqueous printing inks have hardly been put to practical use except for some uses. This is because in such a field, the quality of the aqueous printing ink is hardly sufficient compared to the solvent-based printing ink.

In other words, when a non-permeable plastic film is used as a printing medium, various problems such as uniform wettability to a substrate and applicability to adhesion have not been solved in addition to drying properties. It was extremely difficult. On the other hand, in the industry of printing on plastic films, in recent years, small lots and varieties of varieties have been advanced, and in order to respond to this, using so-called general-purpose ink that can be adhered to various plastic films and adapted to various uses, Work efficiency and economy are improved.

[0004] As a binder for a solvent-type general-purpose ink,
Polyurethane resins tend to be mainly used, and polyurethane resins are considered to be suitable for aqueous printing inks for general use. However, the conventional water-based polyurethane resin has a drawback that, although it can provide adhesion to a polyester film, it has poor adhesion to a treated polyolefin film, which is in great demand as a packaging plastic film.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a water-based surface printing ink composition for packaging which has good heat resistance and adheres to any of corona-discharge treated polypropylene film, corona-discharge treated polyethylene film and aluminum. Is to provide.

[0006]

SUMMARY OF THE INVENTION The present invention provides at least one
(A) having at least two ionic functional groups and at least two isocyanate groups, a compound (B) having a polyoxyethylene unit, and an organic polyisocyanate (C). The obtained isocyanate group-containing polymer is reacted with a polyhydrazide compound (D) and a polyamine compound (E) other than the polyhydrazide compound. Further, 5-180 milliequivalent ionic functional groups per 100 g of the resin and 20% by weight or less A surface printing aqueous printing ink composition for packaging, characterized by using an aqueous polyurethane resin containing polyethylene units as a binder.

The content of the ionic functional group in the aqueous polyurethane resin is in the range of 5 to 180 milliequivalents per 100 g of the resin, and the content of the polyoxyethylene unit is in the range of 20% by weight or less. Milliequivalent,
The latter is more preferable in the range of 10% by weight or less because the balance between water dispersibility and storage stability and water resistance becomes good. Hereinafter, the configuration of the present invention will be described in detail.

As the compound (A) having at least one ionic functional group and at least two isocyanate group-reactive groups, the compounds disclosed in JP-B-43-9076 can be used. it can. Examples of the ionic functional group include a quaternary ammonium group, a tertiary amino group, a carboxylate group, a carboxyl group, a sulfonate group, a sulfonic acid group, a phosphonium group, a phosphinic acid group, and a sulfate group. Of these, functional groups such as a carboxyl group and a tertiary amino group, which are ion precursor groups, can be easily converted to ionic groups by neutralization or quaternization reaction with ammonia, a tertiary amine, acetic acid, hydrochloric acid, or the like. .

Specific examples of the compound having at least one ionic functional group and at least two isocyanate groups and a reactive group include 2,2-dimethylolpropionic acid, 2,2-dimethylolbutyric acid, and 2,2-dimethylolbutyric acid. Dimethylolalkanoic acids such as 2,2-dimethylolvaleric acid, glutamine, asparagine, lysine, diaminopropionic acid, ornithine, diaminobenzoic acid, diamine-type amino acids such as diaminobenzenesulfonic acid, glycine, alanine, glutamic acid, taurine, aspartic acid, Monoamine type amino acids such as aminobutyric acid, valine, aminocaproic acid, aminobenzoic acid, aminoisophthalic acid, sulfamic acid, aminosulfonic acids and their oxyalkylated and polyesterified products, diaminocarboxylic acid, sodium diaminobenzenesulfonate Glycerin monophosphate disodium salt, sodium hydroxyethylphosphonate, sodium dimethylolphosphinate, N-methylethanolamine, polyester polyol having sodium 5-sulfoisophthalate unit, low molecular weight glycol and aliphatic or aromatic polybasic Addition with acid anhydride
Examples thereof include a carboxyl group-containing polyester polyol obtained by a condensation reaction, and a carboxyl group-containing polymer polyol obtained by subjecting a lactone to ring-opening polymerization with 2,2-dimethylolalkanoic acid as an initiator.

Compound having a polyoxyethylene unit
(B) is an active hydrogen capable of reacting with an isocyanate group,
Compounds having two or more oxyethylene units (—OCH ₂ —CH ₂ —), for example, glycols having the following structural formula: H (—OCH ₂ —CH ₂ —) _n OH (where n is 2 or more) Integer.) Polyethylene glycol having a molecular weight of 400 or more, polyethylene glycol having one end methylated, polyethylene-propylene (block or random copolymerized) glycol, oxyethylene diaminopropyl ether, and the like are included.

As the organic polyisocyanate (C), aromatic, aliphatic and alicyclic known organic polyisocyanates can be used. For example, tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 1,3-phenylene diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, 1,5-
Diisocyanates such as naphthylene diisocyanate, isophorone diisocyanate, dimeryl diisocyanate, lysine diisocyanate, hydrogenated 4,4'-diphenylmethane diisocyanate, hydrogenated tolylene diisocyanate, dimer diisocyanate in which the carboxyl group of dimer acid is converted to an isocyanate group, or these There are isocyanate adducts at both ends of glycerols or diamines, or mixtures thereof. If necessary, tri- or higher-functional polyisocyanates such as triphenylmethane triisocyanate and polymethylene polyphenyl isocyanate are also used as diisocyanates. Can be used as a mixture. Further, if necessary, monoisocyanates may be used as a molecular weight modifier. In addition, commercially available polyisocyanate adducts such as Desmodur series (trade name, manufactured by Bayer AG, Germany) can also be used.

The polyhydrazide compound (D) is a compound having two or more hydrazide groups in a molecule.

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Saturated aliphatic carboxylic acids having 2 to 18 carbon atoms such as oxalic acid dihydrazide, malonic acid dihydrazide, succinic acid dihydrazide, glutaric acid dihydrazide, adipic acid dihydrazide, sebacic acid dihydrazide, etc. Monohydric unsaturated dicarboxylic acid dihydrazide such as dihydrazide, maleic acid dihydrazide, fumaric acid dihydrazide, itaconic acid dihydrazide, phthalic acid dihydrazide, carbonate polyhydrazide such as carbonic acid dihydrazide, carbodihydrazide, thiocarbodihydrazide, 4,4′-oxybis Benzenesulfonyl hydrazide, polyacrylic acid hydrazide and the like can be mentioned. Of these, particularly preferred are
Dihydrazides.

Examples of the polyamine compound (E) other than the polyhydrazide compound include ethylenediamine, trimethylenediamine, tetramethylenediamine, pentamethylenediamine, 1,7-diaminoheptane, 1,8-diaminooctane,
Diamines such as xylylenediamine, 1,4-diaminocyclohexane, isophoronediamine, and phenylenediamine; triamines such as triaminopropane; terminal amino groups or hydroxyl groups obtained by reacting these with organic polyisocyanate compounds or polyepoxy compounds Can be used.

To produce an aqueous polyurethane resin used as a binder in the aqueous printing ink composition of the present invention, a compound having at least one ionic functional group and at least two isocyanate groups and a reactive group is used. (A)
The compound (B) having a polyoxyethylene unit, a polyhydroxy compound if necessary, and an excess amount of an organic polyisocyanate (C) are reacted at room temperature to 140 ° C, preferably 40 to 100 ° C, according to a conventionally known method. This produces an isocyanate group-containing polymer, and then the polyhydrazide compound (D) is reacted with a polyamine compound (E) other than the polyhydrazide compound. When producing the isocyanate group-containing polymer, it is appropriate to carry out the reaction in an equivalent ratio of the isocyanate group to the active hydrogen in the range of about 1.02 to 3: 1, preferably 1.05 to 2.2: 1. Furthermore, after producing an isocyanate group-containing polymer, a polyhydrazide compound
(D) and polyamine compounds other than polyhydrazide compounds
(E) is reacted.

The polyhydroxy compounds include water, ethylene glycol, diethylene glycol, triethylene glycol, butanediol, propanediol, 1,6-
Low molecular weight glycols such as hexanediol, neopentyl glycol, cyclohexanedimethanol, triols such as trimethylolpropane and glycerin, low molecular weight polyols such as tetraols such as pentaerythritol, polyether diols, polyester diols and the like In addition to bisphenols such as bisphenol A and bisphenol F, and glycols obtained by adding an alkylene oxide such as ethylene oxide and propylene oxide to bisphenol A and bisphenol F.

The polyether diols include, for example, tetrahydrofuran or polymers, copolymers or graft copolymers of alkylene oxides such as ethylene oxide, propylene oxide and butylene oxide, or hexanediol, methylhexanediol and heptanediol. , Octanediol or polyether glycols obtained by condensation of these mixtures, and propoxylated or ethoxylated polyether glycols.

The polyester diols include ethylene glycol, propylene glycol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol,
Hexanediol, methyl-1,5-pentanediol, octanediol, cyclohexanediol, 2-ethyl-
Condensation reaction from a saturated or unsaturated low molecular weight glycol such as 1,3-hexanediol, bisphenol A, diethylene glycol, triethylene glycol, dipropylene glycol and an aliphatic or aromatic dibasic acid or an aromatic dibasic ester Polyester polyols obtained by ring-opening polymerization of cyclic ester compounds such as ε-polycaprolactone and polyester polyols, polycarbonate polyols, silicon polyols and the like, and also the reaction products of terminal hydroxyl groups obtained by reacting these with diisocyanate. Can be used.

In the above reaction, if necessary, a conventionally known urethanizing catalyst, for example, dibutyltin dilaurate,
Tin octylate, triethylamine, N, N-dimethylbenzylamine, sodium hydroxide, diethylzinc tetra (n-
Butoxy) titanium and the like can be used. further,
Although the preparation of the isocyanate group-containing polymer can be carried out without a solvent, an organic solvent which is inert to the isocyanate group can be used in order to homogenize the reaction and adjust the viscosity. Specific examples of such organic solvents include acetone,
Examples thereof include methyl ethyl ketone, ethyl acetate, dioxane, acetonitrile, tetrahydrofuran, diglyme, dimethyl sulfoxide, and N-methylpyrrolidone. These solvents may be used alone or as a mixture.

On the other hand, with respect to the dispersion or dissolution of the aqueous polyurethane resin in water, the aqueous polyurethane resin can be dispersed or dissolved in water by a conventionally known method after the production. The polyisocyanate group-containing polymer may be dispersed in water or after the dispersion, and then the polyhydrazide compound (D) and a polyamine compound (E) other than the polyhydrazide compound may be used to increase the molecular weight. These reaction methods can be selected according to the purpose. The conversion of the ionic functional group, for example, a carboxyl group into an ionic (salt) group in the isocyanate group-containing polymer may be performed before, simultaneously with, or after the addition of the isocyanate group-containing polymer to water. .

Examples of the basic compound for neutralizing a carboxyl group include ammonia, monoethylamine, diethylamine, trimethylamine, triethylamine, triisopropylamine, tributylamine, triethanolamine, methyldiethanolamine, monoethanolamine, dimethylethanolamine, and diethylethanol. Amine, morpholine, N-methylmorpholine, 2-amino-2-
Organic amines such as ethyl-1-propanol and inorganic alkalis such as sodium hydroxide and potassium hydroxide, and the like, and used alone or in combination of two or more,
In order to improve the water resistance of the film after drying, those which are water-soluble and have high volatility which are easily dissociated by heat are preferable, and ammonia, trimethylamine and triethylamine are particularly preferable.

The amounts of the polyhydrazide compound (D) and the polyamine compound (E) other than the polyhydrazide compound used are as follows:
It is preferable that the amount of active hydrogen be 1.01 to 2.00 with respect to 1 equivalent of free isocyanate groups in the isocyanate group-containing polymer. Outside this range, adverse effects such as a decrease in the storage stability and film strength of the aqueous dispersion and discoloration are observed. However, when the chain extender is water, it is not applicable because it is in a large excess with respect to the isocyanate group. Further, the reaction temperature can be in the range of room temperature to 95 ° C. depending on the reactivity between active hydrogen and the isocyanate group, but is preferably in the range of room temperature to 50 ° C.

The aqueous polyurethane resin thus obtained can be used as it is after dispersing in water. However, usually, a heating operation is carried out for the purpose of removing various organic solvents used in combination.
In general, a step of azeotropic removal together with water by a pressure reducing operation is employed. The molecular weight of the aqueous polyurethane resin is preferably in the range of 5000 to 200,000. If the molecular weight of the aqueous polyurethane resin is less than 5000, the water resistance of the formed ink film tends to be inferior,
When it exceeds, the resulting aqueous printing ink tends to have a high viscosity and a low resolubility.

Further, the acid value of the obtained aqueous polyurethane resin is preferably in the range of 5 (mg KOH / g of resin solids) to 100 (mg KOH / g of resin solids). When the acid value is less than 5, the dispersion and solubility of the polyurethane resin in water are poor, so that there is a problem in stability such as separation of the resin and occurrence of precipitation. Poor printability such as plate fogging and plate clogging. On the other hand, when the acid value exceeds 100, the dispersion and solubility of the polyurethane resin in water are improved and the stability is improved, but when used as a binder for an aqueous printing ink, the water resistance after forming an ink film is poor. .

The aqueous printing ink composition of the present invention contains an aqueous resin such as shellac, rosin-modified maleic acid resin, aqueous acrylic resin, aqueous polyester resin, or an existing aqueous polyurethane resin as long as the object of the present invention is not hindered. Can be blended. Further, in order to impart necessary properties as an aqueous printing ink, a coloring agent such as a pigment, an extender pigment, a wax, an antifoaming agent, a thickener, a curing agent, water and a water-miscible organic solvent are appropriately added. A water-based printing ink is manufactured by performing dispersion using a meat mill such as an attritor or a sand mill, and adjusting the viscosity to a predetermined value. The aqueous printing ink thus obtained is diluted with a solvent mixed with water or a water-miscible organic solvent such as ethyl alcohol, isopropyl alcohol, and normal propyl alcohol until the proper viscosity is obtained during printing, Printing on a plastic film or aluminum by gravure printing or flexographic printing can obtain a packaging material having excellent heat resistance.

[0026]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples, but the present invention is not limited thereto. In the examples, "parts" means "parts by weight",
"%" Represents "% by weight", respectively. (Synthesis Example 1) While introducing nitrogen gas into a reactor equipped with a thermometer, a stirrer, a reflux condenser, and a nitrogen gas inlet tube,
Poly (3-methyl-) having an average molecular weight (hereinafter referred to as Mw) of 2000
1,5-pentane adipate) diol 107.2 parts, Mw = 2000
Of polyethylene glycol 14.9 parts, 2,2-dimethylolpropionic acid 28.7 parts, isophorone diisocyanate 110.0
Part was subjected to a boiling point reaction in 200 parts of methyl ethyl ketone for 6 hours to obtain a terminal isocyanate prepolymer.
After cooling to ℃, 100 parts of acetone was added to obtain an organic solvent solution of a terminal isocyanate prepolymer. next,
13.3 parts of adipic dihydrazide and isophorone diamine 2
To a mixture of 5.9 parts and 400 parts of acetone, an organic solvent solution of the obtained terminal isocyanate prepolymer 600
The mixture was gradually added at room temperature and reacted at 50 ° C. for 3 hours to obtain a solution of a polyurethane resin in an organic solvent. Next, 700 parts of deionized water containing 13.0 parts of 28% ammonia water is gradually added to the organic solvent solution of the above polyurethane resin to neutralize and solubilize the water. After removal, water was added to adjust the viscosity to obtain a polyurethane resin aqueous solution a. The molecular weight was measured by gel filtration chromatography using a refractive index detector in terms of polystyrene.

(Synthesis Example 2) A polyurethane resin aqueous solution b was obtained from the following raw materials in the same manner as in Synthesis Example 1. Polycarbonate diol (Mw = 2000) 131.0 parts Polyethylene glycol (Mw = 2000) 30.1 parts 2,2-Dimethylolpropionic acid 25.2 parts Isophorone diisocyanate 89.5 parts Methyl ethyl ketone 200 parts Acetone 100 parts Adipic dihydrazide 14.7 parts Isophorone diamine 9.6 parts Acetone 400 parts 11.4 parts of 28% ammonia water 700 parts of deionized water

(Synthesis Example 3) A polyurethane resin aqueous solution c was obtained from the following raw materials in the same manner as in Synthesis Example 1. Polypropylene glycol ether (Mw = 2000) 117.7 parts Polyethylene glycol (Mw = 2000) 29.9 parts 2,2-Dimethylolpropionic acid 28.6 parts Isophorone diisocyanate 95.7 parts Methyl ethyl ketone 200 parts Acetone 100 parts Carbodihydrazide 6.9 parts Spirodiamine 21.2 parts Acetone 400 parts 13.0 parts of 28% ammonia water 700 parts of deionized water

(Synthesis Example 4) A polyurethane resin aqueous solution d was obtained from the following raw materials in the same manner as in Synthesis Example 1. Polycaprolactone diol (Mw = 2000) 118.6 parts Polyethylene glycol (Mw = 2000) 30.1 parts 2,2-Dimethylolpropionic acid 28.8 parts Isophorone diisocyanate 96.4 parts Methyl ethyl ketone 200 parts Acetone 100 parts Adipic dihydrazide 8.8 parts Isophorone diamine 17.2 parts Acetone 400 Parts 28% ammonia water 13.1 parts deionized water 700 parts

(Synthesis Example 5) A polyurethane resin aqueous solution e was obtained from the following raw materials in the same manner as in Synthesis Example 1. Butanediol adipate (Mw = 2000) 74.9 parts Polyethylene glycol (Mw = 2000) 22.8 parts 2,2-Dimethylolpropionic acid 43.7 parts Isophorone diisocyanate 12.5 parts Methyl ethyl ketone 200 parts Acetone 100 parts Adipic dihydrazide 11.4 parts Isophorone diamine 22.3 parts Acetone 400 Part 28% ammonia water 22.0 parts deionized water 700 parts

(Synthesis Example 6) A polyurethane resin aqueous solution f was obtained from the following raw materials in the same manner as in Synthesis Example 1. Poly (3-methyl-1,5-pentane adipate) diol (Mw = 2000) 59.7 parts Polyethylene glycol (Mw = 2000) 15.2 parts 2,2-Dimethylolpropionic acid 35.9 parts Isophorone diisocyanate 135.7 parts Methyl ethyl ketone 200 parts Acetone 100 parts Isophorone diamine 53.5 parts Acetone 400 parts 28% ammonia water 16.3 parts Deionized water 700 parts

(Synthesis Example 7) A polyurethane resin aqueous solution g was obtained from the following raw materials in the same manner as in Synthesis Example 1. Poly (3-methyl-1,5-pentane adipate) diol (Mw = 2000) 115.2 parts Polyethylene glycol (Mw = 2000) 45.6 parts 2,2-Dimethylolpropionic acid 25.2 parts Isophorone diisocyanate 89.3 parts Methyl ethyl ketone 200 parts Acetone 100 parts Adipic dihydrazide 24.7 parts Acetone 400 parts 28% ammonia water 11.4 parts Deionized water 700 parts

(Synthesis Example 8) A polyurethane resin aqueous solution h was obtained from the following raw materials in the same manner as in Synthesis Example 1. Butanediol adipate (Mw = 2000) 209.0 parts Polyethylene glycol (Mw = 2000) 37.3 parts Isophorone diisocyanate 41.0 parts Methyl ethyl ketone 200 parts Acetone 100 parts Carbodihydrazide 3.1 parts Spirodiamine 9.6 parts Acetone 400 parts Deionized water 700 parts

(Synthesis Example 9) 2,2-Dimethylolpropionic acid 75.3 parts Isophorone diisocyanate 174.8 parts Methyl ethyl ketone 200 parts Acetone 100 parts Adipic dihydrazide 25.2 parts Isophorone diamine 24.7 parts Acetone 400 parts 28% ammonia water 37.9 parts Deionized water 700 Table 1 shows the characteristic values of the aqueous polyurethane resin solutions obtained in Synthesis Examples 1 to 9.

[0035]

[Table 1] * 1 (milli-equivalent / 100 g of resin)

Example 1 An aqueous printing ink was prepared by diluting an aqueous solution of a polyurethane resin a with water into a solid content of 25% by a conventional method with the following composition, and Zahn Cup # 3 (manufactured by Rigosha).
And diluted with a mixed solvent of water / isopropyl alcohol = 1/1 so that the temperature becomes 18 seconds (25 ° C.), and corona-treated polypropylene film (Pyrene P2161, manufactured by Toyobo Co., Ltd., thickness
20 μm), corona-treated unstretched polypropylene film (Tocello CP SC, manufactured by Tocelo Co., Ltd., thickness 25 μm)
m), gravure printing at a drying temperature of 60 ° C and a printing speed of 80m / min using a gravure plate with a plate depth of 25µm on the corona-treated surface of a corona-treated polyethylene film (Tocello TUX TC, Tokyo Cellophane Paper, thickness 40µm). Then, the coloring property, adhesiveness, heat resistance and water resistance indicating the quality of pigment dispersibility were evaluated. Similarly, using a gravure plate with a plate depth of 25 μm on untreated soft aluminum (made of Sumigumi aluminum foil, thickness 25 μm),
Printing was performed under the same printing conditions to evaluate the color development, adhesion, heat resistance and water resistance. Polyurethane resin aqueous solution a 70 parts Phthalocyanine blue pigment 18 parts (Toyo Ink Mfg. Co., Ltd., Lionol Blue KLH) Water 6.9 parts Isopropyl alcohol 5 parts Silicone defoamer 0.1 part (Toray Silicone Co., Ltd. Toray Silicone SC5540) The evaluation was based on the following method.

(1) Colorability The appearance of the printed matter was visually judged comprehensively in terms of density, gloss and transparency. The judgment values of the evaluation result are as follows. 5: Very good. 4: Excellent. 3: Normal. 2: Inferior. 1: Very poor.

(2) Adhesion After the printed matter was allowed to stand for one day, a cellophane tape was stuck on the printed surface, and the appearance of the printed film when the cellophane tape was rapidly peeled was visually judged. The judgment values of the evaluation result are as follows. 5: The printed film was not peeled at all. 4: 80% or more of the printed film remained on the film. 3: 50-80% of the printed film remained on the film. 2: 30-50% of the print film remained on the film. 1: Less than 30% of the print film remained on the film.

(3) Heat resistance After the printed matter is left for one day, an aluminum foil is overlaid on the printed surface, and a heat seal tester (manufactured by Tester Sangyo Co., Ltd.)
After the thermocompression bonding was performed at a temperature of 1 kg / cm ² for 1 second while changing the temperature, the appearance of the printed film when this was rapidly peeled was visually observed. At this time, the heat resistance was evaluated at the limit temperature at which the ink did not migrate to the aluminum foil surface.

(4) Blocking resistance After the printed matter is left for one day, a load of 0.5 kg / cm ² is applied to a printed surface and a printed surface and a printed surface and a non-printed surface. At 40 ° C. for 20 hours. Thereafter, the appearance of the printed film when it was peeled off was visually determined. The judgment values of the evaluation result are as follows. 5: The printed film was not peeled at all. 4: 80% or more of the printed film remained on the film. 3: 50-80% of the printed film remained on the film. 2: 30-50% of the print film remained on the film. 1: Less than 30% of the print film remained on the film.

(5) Water resistance After the printed matter was allowed to stand for one day, the printed surface was rubbed with water-absorbent absorbent cotton, the appearance of the printed film was visually determined, and the number of times the printed surface was rubbed off was evaluated.

Examples 2 to 5 and Comparative Examples 1 to 4 Instead of the aqueous polyurethane resin solution a, an aqueous polyurethane resin solution b (Example 2) and an aqueous polyurethane resin solution c were used, respectively.
(Example 3), polyurethane resin aqueous solution d (Example 4), polyurethane resin aqueous solution e (Example 5), polyurethane resin aqueous solution f (Comparative Example 1), polyurethane resin aqueous solution g (Comparative Example 2), polyurethane resin aqueous solution h (Comparative Example 3) A water-based printing ink was prepared and evaluated in the same manner as in Example 1 except that an aqueous polyurethane resin solution i (Comparative Example 4) was used. Table 2 shows the results.

[0043]

[Table 2]

[0044]

According to the present invention, there is provided an aqueous printing ink having excellent adhesion and heat resistance to any of corona-discharged polypropylene film, polyethylene film and aluminum used as a plastic film for packaging. can do.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-7-102204 (JP, A) JP-A-7-292307 (JP, A) JP-A-6-206972 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) C09D 11/00-11/20

Claims (3)

(57) [Claims] 1. A compound (A) having at least one ionic functional group and at least two isocyanate group-reactive groups, and a compound having a polyoxyethylene unit
An isocyanate group-containing polymer obtained by reacting (B) with an organic polyisocyanate (C) is reacted with a polyhydrazide compound (D) and a polyamine compound (E) other than the polyhydrazide compound.
An aqueous printing ink composition for packaging printing, characterized in that an aqueous polyurethane resin containing 5-180 milliequivalents of ionic functional groups and 20% by weight or less of polyethylene units is used as a binder. 2. The polyhydrazide compound (D) and the polyamine compound (E) other than the polyhydrazide compound have a molar ratio of:
2. The aqueous printing ink composition for surface printing for packaging according to claim 1, wherein (D) / (E) = 95/5 to 5/95. 3. A packaging material obtained by printing the aqueous printing ink composition for packaging printing according to claim 1 on a plastic film or aluminum.