JPH08120205A - Water-base printing ink composition for laminate and laminating method using same - Google Patents

Abstract

PURPOSE: To provide a water-base printing ink which shows excellent bonding properties and laminate strength to a large variety of plastic films and is highly suitable for direct laminating. CONSTITUTION: A water-base printing ink composition for laminate composed primarily of a pigment and a water-base binder resin varnish, wherein the said water-base binder resin varnish comprises a water-base binder resin varnish (a) formed by dissolving or dispersing a polyurethane resin of a number average molecular weight of 5,000-200,000 in water in the presence of a basic compound and/or an emulsifying agent and a water-base binder resin varnish (b) formed by dispersing a maleic-(anhydride)-modified polypropylene of an acid value of 15-100, obtained by modifying a polypropylene of a number average molecular weight of 2,000-200,000 with maleic acid (anhydride), in water in the presence of a basic compound and an emulsifying agent, the solid contents of components (a) and (b) accounting for 95-50wt.% and 5-50wt.% of the total solid content of the said water-base binder resin varnish, respectively.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-based printing ink composition for laminating and a laminating method using the same, more specifically, it can be applied to various plastic films, and particularly has adhesiveness to a polyolefin film,
The present invention relates to a water-based printing ink composition for lamination, which has excellent suitability for direct lamination of molten polypropylene, and a lamination method using the same.

[0002]

2. Description of the Related Art In recent years, in order to cope with diversification and beauty of packaging containers, plastic films have been printed with printing ink and then laminated packaging bags have been manufactured.

Here, laminating is a method in which ink is printed on various films and then molten plastic is laminated on the printed surface via an anchor coating agent (normal extrusion laminating method), or a plastic film is formed via an adhesive. Either by laminating (dry laminating method) or by printing ink on a film such as polypropylene film and then directly laminating molten resin such as molten polypropylene on the printed surface (direct laminating method). Therefore, the obtained laminated product is used in the field of food packaging containers and the like because the ink does not come into contact with the contents and is excellent in hygiene and gives a printed product a high-grade feeling.

The printing ink used to obtain these laminated products has heretofore been one in which a polyurethane resin having good adhesion to a plastic film having a polar group is used as a binder. In the usual extrusion laminating and direct laminating methods of melting and laminating the resin, the adhesiveness (lamination strength) between the printed surface and the laminating material is low, and this tendency is particularly remarkable in the case of a direct laminated product.

Therefore, as an ink binder, a polyurethane resin having adhesiveness with a wide range of plastic films and a chlorinated polypropylene having particularly good adhesiveness with respect to a polyolefin film are used in combination at a specific composition ratio. An organic solvent-based ink (for example, Japanese Patent Laid-Open No. 4-4148) that can be printed on various plastic films and is suitable for direct lamination is used.

However, from the viewpoints of environmental problems, resource saving, labor safety, fire, etc., in recent years, there has been a strong demand for water-based printing inks in which the use of organic solvents is suppressed to the utmost. Especially for laminated packaging bags, the ink film is embedded between the film to be printed and the laminated film, and harmful organic solvents tend to remain, which adversely affects the contents. Demand for water-based inks is increasing.

In order to meet this demand, the binder resin has been made water-based, but a printing ink using an ordinary water-based polyurethane resin as a binder has poor adhesiveness to the surface of the plastic film and has a sufficient laminating suitability. There was a problem that I could not get it.

Therefore, the applicant of the present invention has proposed a printing ink having a hydrazine residue in the molecule of an aqueous polyurethane resin binder, which has good adhesion to various plastic films, particularly polyolefin films, and extrusion laminating suitability. No. 206972.

However, it has been difficult to obtain a printing ink having a good suitability for direct lamination even if only the above binder resin is used.

On the other hand, the use of chlorinated polypropylene in an aqueous system causes the following problems.

Since chlorinated polypropylene is particularly soluble in an aromatic organic solvent or the like, it can be used relatively easily as a binder resin for a solvent-based coating composition, its adhesiveness to the polypropylene film surface, and its direct laminating suitability. Can be improved. However, chlorinated polypropylene does not dissolve in water at all, and its dispersibility in water is low even if an emulsifier or the like is used, and therefore it is difficult to use it as a binder resin for an aqueous coating composition.

Particularly in a printing ink composition, when a binder resin having a low dispersibility is used, the printability and the viscosity stability over time are markedly reduced. It becomes more difficult to use low chlorinated polypropylene.

Therefore, an aqueous printing ink for laminating in which polypropylene oxide is used instead of chlorinated polypropylene is proposed in JP-A-4-366180. However, since polypropylene oxide having good dispersion stability in water has a low molecular weight, the cohesive force of the resin itself is weakened, and good adhesiveness cannot be obtained.

For this reason, it is aqueous and
At present, a printing ink composition having good adhesiveness to a wide variety of plastic films and good suitability for direct lamination has not yet been obtained.

[0015]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to solve the above-mentioned problems, and it shows good adhesiveness and laminating strength to a wide variety of plastic films even though it is a water-based printing ink, and further direct lamination. An object of the present invention is to provide a water-based printing ink having excellent processability and a laminating method using the same.

[0016]

Means for Solving the Problems That is, the present invention provides a water-based printing ink composition for laminating comprising a pigment and an aqueous binder resin varnish as a main component, wherein the aqueous binder resin varnish comprises: a) an organic diisocyanate compound and a polymeric diol. A polyurethane resin having a number average molecular weight of 5,000 to 200,000 obtained by reacting a compound, a chain extender, and a reaction terminator is dissolved or dispersed in water in the presence of a basic compound and / or an emulsifier. An aqueous binder resin varnish present, b) a (anhydrous) maleic acid-modified polypropylene having an acid value of 15 to 100, which is obtained by modifying polypropylene having a number average molecular weight of 2,000 to 200,000 with (anhydrous) maleic acid, Aqueous binder resin obtained by dispersing in water in the presence of a basic compound and an emulsifier Varnish, and c) an aqueous binder resin varnish obtained by dissolving or dispersing other aqueous resin in water in the presence of a basic compound and / or an emulsifier, and based on the total solid content of the aqueous binder resin varnish. And a solid content of component a is 95 to 50% by weight, a solid content of component b is 5 to 50% by weight, and a solid content of component c is 0 to 10% by weight. The present invention relates to an aqueous printing ink composition.

In the above, (anhydrous) maleic acid means maleic acid and / or maleic anhydride.

As a preferred embodiment thereof, as the component a, an aqueous binder resin in which a polyurethane resin having a carboxyl group in the molecule and having an acid value of 5 to 100 is dissolved or dispersed in water in the presence of a basic compound. The above-mentioned aqueous printing ink composition for laminating using a varnish, wherein a polyurethane resin having at least one hydrazine residue in the molecule as a component is dissolved or dispersed in water in the presence of a basic compound and / or an emulsifier. The aqueous printing ink composition for laminating using the aqueous binder resin varnish, the aqueous printing ink composition for laminating, wherein the polymer diol compound is polyester diol and / or polycarbonate diol, and an acid value of 20 to 20 as component b. 60 (maleic anhydride) modified poly The present invention relates to the above aqueous printing ink composition for lamination, which uses an aqueous binder resin varnish obtained by dispersing propylene in water in the presence of a basic compound and an emulsifier.

Further, the present invention comprises the steps of printing the above-mentioned aqueous printing ink composition for laminating on a plastic film,
The present invention relates to a method for laminating printed matter, which comprises laminating plastic films.

Further, as a preferred embodiment thereof, the present invention relates to a method for laminating a printed matter, which comprises printing the aqueous printing ink composition for laminating on a polypropylene film and laminating a molten polypropylene resin thereon.

[0021]

The present invention relates to an aqueous printing ink composition for plastic films, which comprises an aqueous polyurethane resin as a main binder and a (anhydrous) maleic acid-modified polypropylene having a defined acid value and molecular weight. .

Conventionally, an aqueous chlorinated polypropylene dispersion obtained by dispersing chlorinated polypropylene in water in the presence of an emulsifier has been used as a binder for an aqueous coating composition. To obtain stable dispersibility, it must be a highly chlorinated polypropylene. However, polypropylene having a high degree of chlorination cannot maintain a highly crystalline molecular structure, and sufficient adhesiveness to the polypropylene film surface cannot be obtained.

Thus, in the case of chlorinated polypropylene, the dispersion stability in water and the adhesiveness to the polypropylene film surface are contradictory performances.

However, in the field of the binder resin used in the aqueous printing ink for laminating of the present invention, both better dispersion stability so as not to reduce printability and higher adhesiveness for direct laminating suitability are obtained. It is required.

Therefore, the present inventors have focused on (anhydrous) maleic acid modified polypropylene having a lower modification degree and better dispersion stability than chlorinated polypropylene, and further, the lower the molecular weight of this modified polypropylene, the more stable the dispersion stability is. Of the dispersion stability in water by focusing on the fact that both the degree of modification and the molecular weight are regulated, focusing on the fact that when the molecular weight is high, the intermolecular cohesive force increases and the adhesiveness to the film becomes good. A water-based binder resin having excellent properties and adhesiveness to the surface of a polypropylene film is obtained.

The present invention will be described in more detail below.

First, as the pigment used in the present invention, an inorganic or organic coloring pigment or an extender pigment which can be generally used in aqueous ink can be used. The usual amount of these pigments used is 1 to 50% by weight in the aqueous ink composition.

Next, as the aqueous binder resin varnish of the printing ink of the present invention, a) a polyurethane-based aqueous binder resin varnish in which a polyurethane resin exists in a state of being dissolved or dispersed in water in the presence of a basic compound and / or an emulsifier. , B) (anhydrous) maleic acid-modified polypropylene-based aqueous binder resin varnish obtained by dispersing (anhydrous) maleic acid-modified polypropylene in water in the presence of a basic compound and an emulsifier, and c) other A water-based binder resin varnish obtained by dissolving or dispersing the water-based resin in water in the presence of a basic compound and / or an emulsifier can be used.

A) Polyurethane Aqueous Binder Resin Varnish The polyurethane resin of the present invention is prepared by reacting an organic diisocyanate compound and a high molecular weight diol compound to synthesize a urethane prepolymer, and then reacting with a chain extender and a reaction terminator. The resulting product is aqueous by a method of dispersing in water in the presence of an emulsifier, or by introducing a free carboxyl group into the molecule and dissolving or dispersing in water in the presence of a basic compound and, if necessary, an emulsifier. It can be used as a varnish. The hydration may be performed at the urethane prepolymer stage.

First, as usable organic diisocyanate compounds, hexamethylene diisocyanate, 2,
Aliphatic diisocyanate compounds such as 2,4-trimethylhexamethylene diisocyanate, isophorone diisocyanate, hydrogenated xylylene diisocyanate, 4,4-
Examples thereof include alicyclic diisocyanate compounds such as cyclohexylmethane diisocyanate, araliphatic diisocyanate compounds such as xylylene diisocyanate and tetramethylxylylene diisocyanate, and aromatic diisocyanate compounds such as toluylene diisocyanate and diphenylmethane diisocyanate. Among them,
The alicyclic or araliphatic diisocyanate compound is preferable from the viewpoint of improving the adhesiveness to various films and the re-solubility of the aqueous printing ink.

As usable polymeric diol compounds, linear glycols such as 1,3-propanediol, 1,4-butanediol and 1,6-hexanediol, 1,2-propanediol and neopentyl are used. Branched glycols such as glycol, 3-methyl-1,5-pentanediol and 2-ethyl-2-butyl-1,3-propanediol, low molecular weight diol components such as ether diols such as diethylene glycol and triethylene glycol And a polyester diol obtained by polycondensation with a dibasic acid component such as adipic acid or phthalic acid, or a ring-opening reaction of a cyclic ester compound such as a lactone, or ethylene oxide, propylene oxide, tetrahydrofuran, etc. Polyether diols obtained by polymerization or copolymerization, Are alkylene carbonates, diallyl carbonate, and carbonate component or phosgene such as dialkyl carbonate, the low molecular weight diol component and polycarbonate diols obtained by reacting a, and polybutadiene glycols and the like.

Further, as the polymer diol compound having a free carboxyl group for making the polyurethane resin aqueous in the presence of a basic compound, the polymer diol component and a tetrabasic acid anhydride such as pyromellitic dianhydride are used. Alternatively, a polymer diol compound obtained by subjecting lactones to ring-opening polymerization using dimethylolpropionic acid or the like as an initiator can be used.

The number average molecular weight of these high molecular weight diol compounds is preferably 500 to 4,000.

From the standpoints of adhesion to plastic films and suitability for laminating, polyester diols and polycarbonate diols can be preferably used as the polymer diol compound, and from the viewpoint of suitability for boiling and retorting, polyesters can be used. Diols can be preferably used.

Next, the chain extender used for chain extension of the urethane prepolymer will be described.

First, as a chain extender usually used,
Glycols such as ethylene glycol and propylene glycol, aliphatic and alicyclic diamines such as hydrazine, ethylenediamine, 1,4-butanediamine, aminoethylethanolamine and isophoronediamine, N-methyldiaminoethylamine, N-ethyldiaminoethylamine Examples of the chain extender that can be used in combination with N-alkyldiaminoalkylamine compounds such as singly or in mixture are glycerin, 1, 2,
Aliphatic polyols such as 3-trimethylolpropane and pentaerythritol, alicyclic polyols such as 1,3,5-cyclohexanetriol, and aliphatic polyamines such as diethylenetriamine, triethylenetetramine and tetraethylenepentamine. You can also

Further, as a chain extender having a free carboxyl group for making a polyurethane resin aqueous in the presence of a basic compound, the following general formula (1):

[0038]

Embedded image

(In the formula, R ¹ is a hydrogen atom, or 1 to
Represents a straight-chain or side-chain alkyl group having 8 carbon atoms), or succinic acid,
Aliphatic carboxylic acid-containing polyols obtained by reacting adipic acid and a lower polyol, phthalic acid, trimellitic acid, pyromellitic acid or an aromatic carboxylic acid-containing product obtained by reacting an anhydride thereof with a lower polyol Mention may be made of polyols.

Further, a chain extender having a hydrazine residue in the molecule can be used for the purpose of imparting higher adhesiveness to a plastic film and excellent laminating strength to a printing ink. General formula (2):

[0041]

Embedded image

(In the formula, R ² represents an alkylene group having 2 to 15 carbon atoms, a divalent alicyclic or aromatic group having 6 to 15 carbon atoms, and 3 to 5 nitrogen atoms. Polyaminohydraside represented by a residue of polyethylene polyamine excluding a primary amino group, R ³ represents a hydrogen atom or a methyl group).

The chain extender of the general formula (2) is prepared by first obtaining a Michael addition compound of a polyamine and a (meth) acrylic acid derivative according to a conventionally known method (Japanese Patent Publication No. 3-8649), and then adding a hydrazine to the compound. It can be obtained by transesterification of the (meth) acrylic acid ester portion.

Here, as the polyamine which can be used for the synthesis of polyaminohydrazide, ethylenediamine, butylenediamine, trimethylhexamethylenediamine, etc.
Aliphatic diamines having 2 to 15 carbon atoms, diaminobenzene, 4,4'-diaminobicyclomethane, 1,
4-diaminocyclohexane, 1,4-bis (aminomethyl) cyclohexane, isophoronediamine, etc., 6-1
Examples thereof include alicyclic or aromatic diamines having 5 carbon atoms, and polyethylene polyamines having 3 to 5 nitrogen atoms such as diethylenetriamine and triethylenetetramine.

On the other hand, examples of the (meth) acrylic acid derivative include alkyl esters, hydroxyalkyl esters, aminoalkyl esters of acrylic acid or methacrylic acid, and among them, acrylic acid derivatives are preferable from the viewpoint of reactivity.

In the chain extender having the molecular structure represented by the general formula (2), the hydrazine residue remains in the polyurethane resin even after the chain extension, and good adhesiveness can be obtained by crosslinking with the film surface. It is possible.

Next, the reaction terminator will be described.

The reaction terminator is used for eliminating the reactivity by chain-extending the urethane prepolymer with a chain extender and then reacting it with an unreacted isocyanate group.

First, as a reaction terminator usually used, N, N such as n-propylamine and n-butylamine is used.
Examples thereof include alkylamines such as di-n-butylamine, alkanolamines such as monoethanolamine and diethanolamine, and monoalcohols such as methanol and ethanol.

Further, as the reaction terminator used for introducing a hydrazine residue into the polyurethane molecule,
A compound having a functional group with hydrazine residues to react with the isocyanate groups, the addition of polyamino hydrazide can be preferably used, hydrazine, the following general formula _{(3): H 2 N-} NH-X-NH-NH ₂ (3), wherein X represents an alkylene group having 1 to 8 carbon atoms, or a residue of a saturated or unsaturated dibasic acid having 1 to 10 carbon atoms, Dihydrazide or a dihydrazide compound of a saturated aliphatic dibasic acid or an unsaturated dibasic acid can also be used.

Specific examples of the alkylenedihydrazine include methylenedihydrazine, ethylenedihydrazine and butylenedihydrazine. Further, as a dihydrazide compound of saturated aliphatic dibasic acid,
Specific examples thereof include oxalic acid dihydrazide, malonic acid dihydrazide, glutaric acid dihydrazide, adipic acid dihydrazide, sebacic acid dihydrazide, and the like, and further dihydrazide compounds of unsaturated dibasic acids, specifically phthalic acid dihydrazide and fumaric acid. Examples thereof include acid dihydrazide and itaconic acid dihydrazide.

A method for producing a polyurethane resin using the above organic diisocyanate compound, polymer diol compound, chain extender and reaction terminator will be described.

First, the organic diisocyanate compound and the high molecular weight diol compound are preferably (1.3 to 3.0):
1, more preferably, after mixing at a molar ratio of (1.5 to 2.0): 1, the necessity or type of use of a solvent or a catalyst, the reaction temperature, etc. are determined according to the reactivity of both. The urethane prepolymer is synthesized by reacting by a known method. Then, the chain extender and the reaction terminator are sequentially reacted to complete the production.

The same compound may be used as the chain extender and the reaction terminator, or a method of simultaneously adding the chain extender and the reaction terminator may be used.

The method for producing a polyurethane resin from these urethane prepolymers is suitable in that each molecule of the polyurethane resin has a substantially uniform structure and the variation in molecular weight is small.

Among the polyurethane resins obtained by the above materials and production method, the polyurethane resin specified in the present invention has a number average molecular weight of 5,000 to 200,000, preferably 10,000 to 100,000. It is a thing.
When the number average molecular weight is less than the above range, the resin film has poor elasticity and becomes fragile, while when the number average molecular weight exceeds the above range, the viscosity of the aqueous polyurethane resin dissolved in water in the presence of the basic compound has a viscosity. In addition, the dispersibility decreases with an aqueous polyurethane resin dispersed in water in the presence of an emulsifier and / or a basic compound.

Next, a method of forming the polyurethane resin of the present invention into an aqueous varnish will be described. First, as a method for forming an aqueous varnish of a polyurethane resin having no free carboxyl group in the molecule, a method of dispersing the polyurethane resin in water in the presence of an emulsifier is mainly used.

As this method, the following two methods can be used.

A. A method in which a urethane prepolymer obtained by reacting an organic diisocyanate compound and a polymer diol compound is dispersed in water in the presence of an emulsifier, and then chain-extended by a chain extender and stopped by a reaction terminator b. A method in which the urethane prepolymer is dissolved in a water-miscible solvent such as methyl acetate, the chain is extended by a chain extender, the reaction is stopped by a reaction terminator, the reaction is stopped by mixing with water containing an emulsifier, and the solvent is distilled off. Examples of the emulsifiers used here include anionic surfactants such as higher alcohol sulfate ester salts, alkylbenzene sulfonates, polyoxyethylene alkyl sulfate ester salts, polyoxyethylene alkyl ethers, polyoxyethylene alkylphenyl ethers. , Sorbitan derivatives, and other nonionic surfactants, which may be used alone or in combination.

On the other hand, as a method of introducing a free carboxyl group into the polyurethane molecule and dissolving or dispersing it in water in the presence of a basic compound and, if necessary, an emulsifier, a high molecular weight diol having the above free carboxyl group is used. A method in which a compound and / or a chain extender is used to dissolve or disperse in water at the chain extension stage and then the reaction is stopped is available. Here, the total amount of the high molecular weight diol compound having a free carboxyl group and the chain extender used is in the range of 5 to 100, more preferably 10 to 60, as the acid value of the polyurethane resin.

When the acid value is lower than the above range, it becomes difficult for the resulting polyurethane resin to maintain a stable self-emulsifying state in an aqueous system, while when the acid value exceeds the above range,
The resulting resin film becomes too hard and a printing ink having good film properties cannot be obtained.

Further usable basic compounds are:
Ammonia, organic amines, alkali metal hydroxides and the like can be mentioned. Specific examples of the organic amines include alkylamines such as diethylamine, triethylamine and ethylenediamine, alkanolamines such as monoethanolamine, ethylethanolamine and diethylethanolamine. Examples of the alkali metal hydroxide include sodium hydroxide and potassium hydroxide. Among them, those which easily volatilize at room temperature or with slight heating are desirable in order to improve the drying property.

Among the aqueous binder resin varnishes of polyurethane resin obtained by the above method, in the field of printing ink, which generally requires high pigment dispersibility and printing reproducibility, it was dissolved in water in the presence of a basic compound. The use of polyurethane resin systems is advantageous. On the other hand, in the field of printing inks that require dryness and water resistance, it is advantageous to use a polyurethane resin system dispersed in water in the presence of an emulsifier. The combined use of agents is more desirable.

The ratio of the polyurethane-based aqueous binder resin varnish used to the total aqueous binder resin varnish of the present invention is as follows:
The amount is such that the solid content of the polyurethane resin is 50 to 95% by weight. When the solid content of the polyurethane resin is less than the above range, the adhesiveness to the polyester or nylon film and the laminating strength are deteriorated. On the other hand, when the solid content is more than the above range, the adhesiveness to the polyolefin film and the direct laminating suitability are deteriorated.

B) (Anhydrous) Maleic Acid-Modified Polypropylene-Based Aqueous Binder Resin Varnish The (anhydrous) maleic acid-modified polypropylene of the present invention is a known method of adding (anhydrous) maleic acid to polypropylene having an isotactic crystal structure, For example, it is obtained by a method of graft polymerization in the presence of a radical polymerization initiator, and is used by dispersing it in water in the presence of an emulsifier and a basic compound.

Radical polymerization initiators that can be used in the graft polymerization include di-tert-butyl peroxide, tert-butyl hydroperoxide, dicumyl peroxide, benzoyl peroxide and ter.
t-butyl peroxide benzoate, di-tert
Examples include peroxides such as -butyl perphthalate and azobis compounds such as azobisbutyronitrile and azobisisopropionitrile.

Here, the grafting ratio of (anhydrous) maleic acid is such that the acid value of the modified polypropylene is 15 to 100,
The amount is generally 20 to 60. When the acid value is smaller than the above range, the dispersion stability in water is lowered, and when the acid value is larger, the adhesiveness to the polypropylene film, the direct laminating suitability and the like are lowered, which is not preferable.

The number average molecular weight of the polypropylene modified with (anhydrous) maleic acid of the present invention is 2,0.
Those of 00 to 200,000 can be used. When the number average molecular weight of the polypropylene is less than 2,000, the adhesion of the water-based ink to the polypropylene film and the suitability for direct laminating decrease, while when the number average molecular weight exceeds 200,000, the dispersion stability in water becomes poor. It is not preferable because it decreases.

As a method for forming an aqueous varnish of the (anhydrous) maleic acid-modified polypropylene obtained by the above materials and manufacturing method, a method of dispersing it in water in the presence of an emulsifier and a basic compound can be used.

Here, usable emulsifiers include nonionic surfactants such as polyoxyethylene alkyl ethers, polyoxyethylene alkylphenol ethers, polyoxyethylene fatty acid esters, and anions such as alkyl sulfate ester salts and alkylphenol sulfonates. Examples of the surfactant include amphoteric surfactants such as alkyl betaine and alkyl imidazoline, and examples of the basic compound include those used for aqueousizing the polyurethane resin.

From the viewpoint of increasing the dispersion stability of the (anhydrous) maleic acid-modified polypropylene in water, the basic compound is preferably used in an amount equal to or more than the equivalent of the (anhydrous) maleic acid-modified polypropylene resin.

The use ratio of the (anhydrous) maleic acid-modified polypropylene-based aqueous binder resin varnish to the total aqueous binder resin varnish of the present invention is (anhydrous) maleic acid-modified polypropylene solid content based on the total solid content of the aqueous binder resin varnish. Is 5 to 50% by weight.
If the solid content of (anhydrous) maleic acid-modified polypropylene is less than the above range, the adhesiveness to a polyolefin film and the suitability for direct laminating are reduced, while if it is increased, the adhesiveness to a polyester or nylon film and the laminating strength are reduced, which is not preferable. .

C) Other Aqueous Binder Resin Varnish In addition to the above essential binder resins, according to the present invention, an aqueous acrylic resin, a cellulose resin, an aqueous polyester resin, an aqueous ethylene-acrylic resin, a petroleum resin, copal, etc. may be used. An aqueous binder resin varnish obtained by dissolving or dispersing various other aqueous resins such as hard resins in water in the presence of a basic compound and / or an emulsifier is used as a resin solid content, and the solid content of all binder resins is 10% by weight. % Can be added.

In the aqueous printing ink composition of the present invention,
The amount of the total aqueous binder resin varnish is 3 to 70 in terms of solid content.
A weight% range is preferred.

It is also possible to add various additives such as water-miscible solvents such as methanol, ethanol, isopropanol, methoxypropanol and N-methylpyrrolidone, pigment dispersants, antiblocking agents, defoaming agents and crosslinking agents. Is.

As a method for producing a water-based printing ink composition for laminating using these various materials, the polyurethane resin, the pigment, and if necessary, the pigment dispersing resin or the pigment dispersing agent are mixed and kneaded, Further, a method of adding and mixing the rest of predetermined materials is general.

The printing ink composition obtained by the above method can be printed on a plastic film by a flexographic or gravure printing method.

Examples of the plastic film on which the printing ink composition for water-based laminate of the present invention is printed include various plastic films such as polyolefin, polyester and nylon, and those subjected to surface treatment such as corona discharge treatment are more preferable. Is.

Further, as a method for laminating a printed matter of the printing ink composition for water-based lamination of the present invention,
After printing the water-based printing ink composition of the present invention on the above various films, the printed surface is coated with various anchor coating agents such as imine-based, isocyanate-based, polybutadiene-based, and titanate-based, and a molten polyethylene resin is usually laminated. Extrusion lamination method, dry lamination method in which an adhesive such as urethane is applied to the printed surface and a plastic film is laminated, and after printing the water-based printing ink composition of the present invention on a polypropylene film, it is directly melted on the printed surface. Any of the direct laminating methods of laminating polypropylene resin can be used.

The printing ink composition of the present invention is water-based and has good laminating suitability by any laminating method, and particularly good direct laminating suitability as compared with conventional printing inks.

When laminating is carried out by the usual extrusion laminating and dry laminating methods, a completely aqueous laminating product can be obtained by using an aqueous anchoring agent or adhesive. It is more advantageous in food hygiene.

Hereinafter, the present invention will be described more specifically with reference to Examples, but the present invention is not limited thereto. Unless stated otherwise, "part" and "%"
Represents "parts by weight" and "% by weight".

<Production of Polyurethane Aqueous Binder Resin Varnish> Production Example 1 Polyneopentyl glycol adipate having a number average molecular weight of 1,000 was placed in a four-necked flask equipped with a thermometer, a stirrer, a cooling tube, and a nitrogen introducing tube. 300 parts of diol and 133.2 parts of isophorone diisocyanate were charged and reacted for 4 hours at 100 to 105 ° C. under stirring while introducing nitrogen gas. Then, 24.1 parts of dimethylolpropionic acid were charged and at 100 to 110 ° C. The reaction was carried out for 2 hours. After confirming that dimethylolpropionic acid has completely reacted, 70 ℃
Cooled to 1076 parts water and triethylamine 2
0.2 part of the aqueous polyurethane resin solution No. No. 2 having a solid content of 30% and a resin acid value of 24 was prepared by adding 0.2 part of the mixture to make it aqueous and then stopping the reaction with 12.1 parts of monoethanolamine. Got 1.

Production Example 2 Using the same apparatus as in Production Example 1, the number average molecular weight was 100
0 polybutylene glycol-adipate diol 300
Parts and 133.4 parts of isophorone diisocyanate were charged, and while introducing nitrogen gas, 100 to 10 with stirring.
The reaction was carried out at 5 ° C for 4 hours, then 24.1 parts of dimethylolpropionic acid was charged, and the reaction was carried out at 100 to 110 ° C for 2 hours. After confirming that dimethylolpropionic acid had completely reacted, the mixture was cooled to 70 ° C., water was added by adding 1059 parts of water and 20.2 parts of triethylamine, and the reaction was stopped with 10 parts of hydrated hydrazine to give a solid content of 30%.
%, Resin acid value 24, aqueous polyurethane resin solution No. Two
I got

Production Example 3 300 parts of polyneopentyl adipatediol having a number average molecular weight of 1,000 and 133.2 parts of isophorone diisocyanate were charged in the same apparatus as in Production Example 1 and stirred while introducing nitrogen gas. The reaction was carried out at 100 to 105 ° C. for 4 hours, and then dimethylolpropionic acid 24.
One part was charged and reacted at 100 to 110 ° C. for 2 hours.
After confirming that dimethylolpropionic acid was completely reacted, the mixture was cooled to 100 ° C., 1128 parts of water and 20.2 parts of triethylamine were charged to make it aqueous, and further the reaction was stopped with 34.8 parts of dihydrazine adipate, Solid content 3
Aqueous polyurethane resin solution No. 0 having a resin acid value of 0% and 24.
3 was obtained.

<Production of Maleic Anhydride-Modified Polypropylene-Based Aqueous Binder Resin Varnish> The number average molecular weight shown in Table 1 obtained by thermally decomposing high molecular weight polypropylene in a container equipped with a reflux tube, a thermometer, and a stirrer. Of polypropylene and maleic anhydride in xylene were charged, the temperature was raised to 140 ° C. under nitrogen substitution, dicumyl peroxide was added, and the mixture was reacted for 4 hours. Xylene and unreacted maleic anhydride were distilled off under reduced pressure to obtain solid maleic anhydride-modified polypropylene.

In an autoclave equipped with an emulsifier, the maleic anhydride-modified polypropylene 200 obtained by the above-mentioned method was added.
Parts, 280 parts of ammonia water containing maleic anhydride-modified polypropylene and an equivalent amount of ammonia, and 20 parts of polyoxyethylene nonylphenyl ether were charged, and the contents were uniformly emulsified at a temperature equal to or higher than the softening point of the maleic anhydride-modified polypropylene. Maleic anhydride-modified polypropylene aqueous dispersion No. 1 shown in FIG. 1-10 were obtained.

<Evaluation of Dispersion Stability of Maleic Anhydride Modified Polypropylene Aqueous Dispersion> Test Method Using a B-type viscometer, a viscosity increase ratio (viscosity after storage at 40 ° C. for 7 days / initial viscosity, , The viscosity value measured at a rotation speed of 60 rpm was used), and the dispersion stability of the maleic anhydride-modified polypropylene aqueous dispersion was evaluated from the size. The results are shown in Table 1.

Evaluation Criteria A: Thickening factor of 1.5 or less B: Thickening factor of more than 1.5 and 4.0 or less C: Thickening factor of more than 4.0 No ． 8 and No. In No. 10, since separation and sedimentation were observed, the dispersion stability was judged to be poor, and no aqueous printing ink composition was produced.

[0090]

[Table 1]

<Production of Examples 1 to 11 and Comparative Examples 1 to 3> According to the formulation shown in Table 2, first, the pigment and the water-soluble resin varnish mixture for dispersing the pigment were kneaded for 30 minutes with a red devil type paint conditioner, and then a predetermined material was added. Were mixed and stirred to obtain water-based printing ink compositions of Examples 1 to 11 and Comparative Examples 1 to 3.

As a pigment, lionol blue FG-
7330 (manufactured by Toyo Ink Mfg. Co., Ltd.), as an aqueous resin varnish for dispersing pigments, John Cryl J-61 (styrene-
Acrylic resin, solid content 30%, manufactured by Johnson Polymer Co., Ltd.) was used.

<Evaluation of Examples 1 to 11 and Comparative Examples 1 to 3> With respect to the water-based printing ink compositions obtained in Examples 1 to 11 and Comparative Examples 1 to 3, adhesiveness, extrusion laminating strength, direct laminating strength. , And resolubility and swimming as printability were evaluated, and the results are shown in Table 2.

Adhesion test method Each test ink was tested with a gravure proofing machine using OPP, P
Printing was performed on ET and Ny films, cellophane tape (TF-12 manufactured by Nichiban Co., Ltd.) was attached to the printing surface, and when the film was rapidly peeled off, the adhesiveness was evaluated from the degree of peeling of the printed film from the film. .

Evaluation Criteria A: The printed film does not peel from the film at all. B: Less than 20% of the area ratio of the printed film peels from the film. C: 20% or more and less than 50% of the area ratio of the printed film peels from the film. D: 50% or more of the area ratio of the printed film is peeled from the film.

Extrusion laminate strength test method OPP of each test ink by gravure proofing machine
The imine-based anchor coating agent (EL-420 manufactured by Toyo Morton Co., Ltd.) was applied to the film printed matter, and 30 μm of polyethylene was melted at 345 ° C. by an extrusion laminating machine.
A laminated product was obtained by laminating the films with a thickness of m.

This laminate was left at 40 ° C. for 3 days, then cut into a width of 15 mm, and the T-type peel strength was measured using a peel tester manufactured by Yasuda Seiki Co., Ltd.

Evaluation Criteria The measured values of the peel strength (g / 15 mm) are shown.

Direct Lamination Test Test Method OPP of each test ink by gravure proofing machine
The film printed matter was laminated with a polypropylene resin melted at 305 ° C. by an extrusion laminating machine at a film thickness of 30 μm to obtain a laminated product. These laminates were cut into a width of 15 mm, and T-type peel strength was measured using a peel tester manufactured by Yasuda Seiki Co., Ltd.

Evaluation Criteria The measured values of peel strength (g / 15 mm) are shown.

Re-dissolution test method Each test ink was kept in the gravure proofing machine for a while O
After printing on the PP film, the operation was stopped and the state was left as it was for 60 seconds. After that, printing was restarted, and re-dissolvability was evaluated from the number of pitches until a normal printed matter was obtained.

Evaluation Criteria A: Return to normal within 5 pitches. B: Return to normal at 6 to 20 pitches. C: Return to normal at 21 to 50 pitches. D: It does not return to normal even if it exceeds 50 pitches.

-Swimming (printing unevenness) test method OPP of each test ink by a gravure proofing machine
The printing unevenness of the printed film was visually evaluated.

Evaluation Criteria A: No printing unevenness is observed B: Slight printing unevenness is observed C: Printing unevenness is severe In the above, the OPP film is a stretched polypropylene film (manufactured by Toyobo Co., Ltd.). P-2161, 30μ
m) and PET film are polyethylene terephthalate film (Toyobo Co., Ltd. E-5102, 12μ
m) and Ny film represent a nylon film (Emblem manufactured by Unitika Ltd., 15 μm).

[0105]

[Table 2]

[0106]

EFFECTS OF THE INVENTION As shown concretely by the above examples, the water-based printing ink composition of the present invention exhibits good adhesiveness to various plastic films, extrusion laminating strength, and excellent printability. Furthermore, it is an aqueous printing ink composition having excellent suitability for direct lamination.

Claims (7)

[Claims] 1. A water-based printing ink composition for laminating comprising a pigment and a water-based binder resin varnish as main components, wherein the water-based binder resin varnish comprises: a) an organic diisocyanate compound, a polymer diol compound, a chain extender, and a reaction stopper. An aqueous binder resin varnish in which a polyurethane resin having a number average molecular weight of 5,000 to 200,000 obtained by reacting an agent is present in a dissolved or dispersed state in water in the presence of a basic compound and / or an emulsifier, b). A (anhydrous) maleic acid-modified polypropylene having an acid value of 15 to 100, which is obtained by modifying polypropylene having a number average molecular weight of 2,000 to 200,000 with (anhydrous) maleic acid, is prepared in the presence of a basic compound and an emulsifier. Aqueous binder resin varnish obtained by dispersing in water, and c) other aqueous resin Consisting of an aqueous binder resin varnish obtained by dissolving or dispersing in water in the presence of a basic compound and / or an emulsifier, and the solid content of the component a is 50 relative to the total solid content of the aqueous binder resin varnish. The water-based printing ink composition for lamination is characterized in that the solid content of the component b is 5 to 50% by weight, and the solid content of the component c is 0 to 10% by weight. 2. An aqueous binder resin varnish in which a polyurethane resin having a carboxyl group in the molecule and having an acid value of 5 to 100 is dissolved or dispersed in water in the presence of a basic compound is used as the component a. Item 2. A water-based printing ink composition for laminating according to Item 1. 3. As the component a, an aqueous binder resin varnish in which a polyurethane resin having at least one hydrazine residue in the molecule is present in a dissolved or dispersed state in water in the presence of a basic compound and / or an emulsifier is used. The aqueous printing ink composition for laminating according to claim 1. 4. The aqueous printing ink composition for laminating according to claim 1, wherein the polymer diol compound is a polyester diol and / or a polycarbonate diol. 5. An aqueous binder resin varnish obtained by dispersing (anhydrous) maleic acid modified polypropylene having an acid value of 20 to 60 in water in the presence of a basic compound and an emulsifier, as the component b. The aqueous printing ink composition for laminating according to any one of 1 to 4. 6. The plastic film according to any one of claims 1 to 5.
A method for laminating a printed matter, comprising: printing the aqueous printing ink composition for laminating according to any one of items 1 to 3 and then laminating a plastic film. 7. A polypropylene film comprising:
6. A method for laminating a printed matter, comprising printing the aqueous printing ink composition for laminating according to any one of 5 and laminating a molten polypropylene resin.