JP7632794B2 - Gravure ink composition - Google Patents

Description

The present invention relates to a gravure ink composition.

As described in Patent Document 1, an ink composition is known that uses a polyurethane resin obtained by chain-extending a urethane prepolymer with an amine compound as a binder. However, the amine compound remains in the ink composition obtained in this manner, so that the ink composition has an amine odor even after printing, making it particularly unsuitable for use in packaging food.

Also, as described in Patent Document 2, it is known that a ketimine compound obtained from a diamine and a ketone is reacted with a special urethane prepolymer to extend the chain of the resulting polyurethane resin, which can be used as a binder for printing ink.
However, when the ink composition is used for reverse printing and extrusion lamination is performed, the extrusion lamination strength is poor. Furthermore, since the ketimine derived from the triamine is used, it cannot be used for chain extension reaction, and the ketimine is reacted after chain extension with another diamine and after terminal termination.

International Publication No. 2013/162003 JP 2012-153883 A

The problem that the present invention aims to solve is to obtain an ink composition that, in a printing ink containing a polyurethane resin, particularly a polyurethane polyurea resin, does not emit an amine odor caused by the amino compound used as a chain extender, etc., and does not impair laminate strength even when used for lamination.

The present inventors have found that the above problems can be solved by using a specific polyurethane polyurea resin as the resin component in the ink composition.
That is, the present invention provides
1. An ink composition containing a polyurethane polyurea resin obtained by reacting a diisocyanate compound with a polymeric diol compound,
the diisocyanate compound contains isophorone diisocyanate, and the polymer diol compound contains one or more selected from polyester polyol, polyalkylene glycol, and polyether diol;
Polyurethane polyurea resin is an ink composition having a ketiminated amino group.
2. The ink composition according to 1, wherein the ketiminated amino group is ketiminated with acetone and/or diethyl ketone.
3. The ink composition according to 1 or 2, wherein the polyurethane polyurea resin is a urethane prepolymer whose chains have been extended, and the portions originating from the chain extender in the molecule are ketiminated.

According to the present invention, the ink composition and printed matter produced using the ink composition do not have the odor characteristic of ketimine. Furthermore, when used as an ink composition for lamination, it has the effect of providing excellent lamination strength.

The ink composition of the present invention is based on the fact that the resin contained is a polyurethane polyurea resin, and the diisocyanate component and diol component constituting the polyurethane polyurea resin are each specific components.
Furthermore, the urethane prepolymer obtained from the diisocyanate component and the diol component is chain-extended and/or terminated with a ketimine compound to form a polyurethane polyurea resin.
Furthermore, a specific ketimine compound is used as a chain extender and/or reaction terminator, and the polyurethane polyurea resin obtained by reacting it with a urethane prepolymer in a specific solvent does not emit a ketimine odor, and furthermore has excellent stability over time when stored in a solution state such as an ink or paint.
The polyurethane polyurea resin-containing ink composition of the present invention will be described below.

(Polyurethane polyurea resin)
The polyurethane polyurea resin in the present invention has at least one type of amino group selected from a primary amino group and a secondary amino group at the molecular terminal, and the amino group is basically a ketimine group.
More preferred is a polyurethane polyurea resin having a hydroxyl group and at least one type selected from a primary amino group and a secondary amino group at the molecular terminal.
As these polyurethane polyurea resins, polyurethane resins obtained by synthesizing a urethane prepolymer by reacting a diisocyanate compound with a high molecular weight diol compound, which is a diol compound, and then reacting this with a chain extender and a reaction terminator described below can be suitably used.

<Synthesis of urethane prepolymer>
The urethane prepolymer is obtained by reacting the following diisocyanate compound with a polymeric diol compound.
(Diisocyanate Compound)
The diisocyanate compound must contain isophorone diisocyanate.
All of the diisocyanate compounds used may be isophorone diisocyanate, but other diisocyanate compounds can also be used in combination.
Other diisocyanate compounds include aromatic diisocyanate compounds such as 1,3- and/or 1,4-phenylene diisocyanate, 4,4-diisocyanatobiphenyl, 3,3-dimethyl-4,4-diisocyanatobiphenyl, and tolylene diisocyanate; alicyclic diisocyanates such as 1,4-cyclohexane diisocyanate, cyclohexylene diisocyanate, dicyclohexylmethane-4,4-diisocyanate (hydrogenated MDI), and methylcyclohexylene diisocyanate (hydrogenated TDI). Examples of the organic diisocyanate compounds include aliphatic diisocyanate compounds such as ethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, dodecamethylene diisocyanate, and 2,2,4-trimethylhexamethylene diisocyanate, and aromatic aliphatic diisocyanate compounds such as m- and/or p-xylylene diisocyanate (XDI) and α,α,α',α'-tetramethylxylylene diisocyanate. These organic diisocyanate compounds can be used alone or in combination of two or more. Among these, alicyclic diisocyanate compounds, aliphatic diisocyanate compounds, and aromatic aliphatic diisocyanate compounds are more preferred.
When other diisocyanate compounds are used in combination, the number of isocyanate groups of the other diisocyanate compounds can be 50% or less, more preferably 30% or less, and even more preferably 10% or less, of the total number of isocyanate groups of all diisocyanate compounds.
Alternatively, the amount of the other diisocyanate compounds is 50 parts by mass or less, more preferably 30 parts by mass or less, and further preferably 10 parts by mass or less, based on 100 parts by mass of the total diisocyanate compounds.

(Polymer diol compound)
As the polymeric diol compound, one or more selected from polyester polyols, polyalkylene glycols and polyether diols can be used.
The polyester polyol may be a condensation product of a diol component and a dicarboxylic acid component, or a condensation product of caprolactone.
As the condensate of a diol component and a dicarboxylic acid component, polyester diols obtained by a condensation reaction of one or more diol components such as ethylene glycol, diethylene glycol, 1,3-propanediol, propylene glycol, 1,4-butanediol, neopentyl glycol, 2-methyl-1,3-propanediol, 3-methyl-1,5-pentanediol, and one or more dibasic acids such as adipic acid, sebacic acid, phthalic anhydride, succinic acid, azelaic acid, and dimer acid, and polyester diol compounds such as polycaprolactone diols can be used.
As the polyalkylene glycol, polyethylene glycol, polypropylene glycol, etc. can be used, and as the polyether diol, an alkylene oxide adduct of bisphenol A, such as ethylene oxide, propylene oxide, etc. can be used.
Among them, those having a number average molecular weight of 1,000 to 8,000 are preferred, those having a number average molecular weight of 1,000 to 5,500 are more preferred, and those having a number average molecular weight of 1,000 to 4,000 are even more preferred.
Among these, 3-methyl-1,5-pentylene adipate diol having a number average molecular weight of 1,000 to 8,000 obtained by condensation reaction of adipic acid and 3-methyl-1,5-pentanediol,
a condensate having a number average molecular weight of 1,000 to 8,000 obtained by a condensation reaction of adipic acid with 1,4-butanediol/neopentyl glycol=20/80 to 80/20 (molar ratio);
a condensate having a number average molecular weight of 1,000 to 8,000 obtained by a condensation reaction of adipic acid with 1,4-butanediol/2-methyl-1,3-propanediol=20/80 to 80/20 (molar ratio);
a condensate having a number average molecular weight of 1,000 to 8,000 obtained by a condensation reaction of adipic acid with diethylene glycol/neopentyl glycol=20/80 to 80/20 (molar ratio);
a condensate having a number average molecular weight of 1,000 to 8,000 obtained by a condensation reaction of adipic acid with diethylene glycol/2-methyl-1,3-propanediol=20/80 to 80/20 (molar ratio);
a condensate having a number average molecular weight of 1,000 to 8,000 obtained by a condensation reaction of sebacic acid/succinic acid=20/80 to 80/20 (molar ratio) with 2-methyl-1,3-propanediol;
a condensate having a number average molecular weight of 1,000 to 8,000 obtained by a condensation reaction of sebacic acid/succinic acid=20/80 to 80/20 (molar ratio) with diethylene glycol;
a condensate having a number average molecular weight of 1,000 to 8,000 obtained by a condensation reaction of dimer acid/succinic acid=20/80 to 80/20 (molar ratio) with 1,3-propanediol;
a condensate having a number average molecular weight of 1,000 to 8,000 obtained by condensation reaction of dimer acid/succinic acid=20/80 to 80/20 (molar ratio) with diethylene glycol;
a condensate having a number average molecular weight of 1,000 to 8,000 obtained by condensation reaction of azelaic acid/succinic acid=20/80 to 80/20 (molar ratio) with 1,4-butanediol;
a condensate having a number average molecular weight of 1,000 to 8,000 obtained by condensation reaction of azelaic acid/succinic acid=20/80 to 80/20 (molar ratio) with 2,5-hexanediol;
is preferred, and 3-methyl-1,5-pentylene adipate diol having a number average molecular weight of 1,000 to 4,000 is more preferred.
When a polymer diol compound other than the above is used in combination, the number of hydroxyl groups of the other polymer diol compound relative to the total number of hydroxyl groups of all the polymer diol compounds can be 70% or less, more preferably 55% or less, and even more preferably 40% or less.
Alternatively, based on 100 parts by mass of the total polymer diol compounds, the amount of polymer diol compounds other than the above is 50 parts by mass or less, more preferably 35 parts by mass or less, and further preferably 20 parts by mass or less.

(Bio-polyester diol compound)
In consideration of the environment, a biopolyester diol compound obtained by synthesis from a material containing a plant-derived component may be used in combination with the polymer diol compound.
In addition, a polyurethane polyurea resin obtained by reacting a polyester diol compound including a bio polyester diol compound with the above-mentioned specific isocyanate compound can be mixed with the polyurethane polyurea resin of the present invention and used.
For this reason, as the other polymer diol compound, a biopolyester polyol (biomass polyester polyol) obtained by reacting a short-chain diol compound having 2 to 4 carbon atoms with a carboxylic acid component can be used. It is more preferable that at least one of the short-chain diol compound and the carboxylic acid component of the biopolyol component is derived from a plant, and it is even more preferable that both are derived from a plant.
There is no particular limitation on the plant-derived short-chain diol compound having 2 to 4 carbon atoms. As an example, the short-chain diol compound may be 1,3-propanediol, 1,4-butanediol, ethylene glycol, etc., which are obtained from plant raw materials by the following method. These may be used in combination.
1,3-propanediol can be produced from glycerol via 3-hydroxypropylaldehyde (HPA) by a fermentation method in which glucose is obtained by decomposing plant resources (such as corn, etc.). 1,3-propanediol compounds produced by biomethods such as the above-mentioned fermentation method can produce useful by-products such as lactic acid from a safety standpoint, and can also keep production costs low, compared to 1,3-propanediol compounds produced by the EO production method. 1,4-butanediol can be produced by producing glycol from plant resources, fermenting the resulting succinic acid, and hydrogenating the resulting succinic acid. Ethylene glycol can also be produced from bioethanol obtained by a conventional method via ethylene.

The plant-derived carboxylic acid component is not particularly limited. For example, the carboxylic acid component may be sebacic acid, succinic acid, lactic acid, glutaric acid, dimer acid, azelaic acid, or the like. These may be used in combination. Among these, it is preferable that the carboxylic acid component contains at least one selected from the group consisting of sebacic acid, succinic acid, and dimer acid. In addition, 0.05 to 0.5 parts by mass of malic acid may be contained per 100 parts by mass of sebacic acid.
The biopolyol component is produced as a 100% plant-derived biopolyester polyol by appropriately condensing a plant-derived short-chain diol compound and a plant-derived carboxylic acid. Specifically, polytrimethylene sebacate polyol is obtained by directly dehydrating and condensing plant-derived sebacic acid and plant-derived 1,3-propanediol. Also, polybutylene succinate polyol is obtained by directly dehydrating and condensing plant-derived succinic acid and plant-derived 1,4-butanediol.
One or more of these biopolyol components may be used.

The urethane prepolymers obtained from these plant-derived components may comprise 10% by mass or more, or 40% by mass or more, calculated as solid content, of the total urethane prepolymers.

(Other diol compounds)
In addition to 3-methyl-1,5-pentylene adipate diol, alkane diols such as 1,4-pentanediol, 2,5-hexanediol, and 3-methyl-1,5-pentanediol, and low molecular weight diol compounds such as ethylene glycol, propylene glycol, 1,4-butanediol, and 1,3-butanediol can be used alone or in combination of two or more kinds.

When reacting the diisocyanate compound and the polymer diol compound, the ratio of use of each is usually in the range of 1.2:1 to 3.0:1, more preferably 1.3:1 to 2.0:1, and even more preferably 1.3:1 to 1.7:1 in terms of the equivalent ratio of isocyanate groups to hydroxyl groups (isocyanate index). If the isocyanate index is less than 1.2, the polyurethane polyurea resin tends to be flexible, and there is a possibility that blocking resistance, etc., will be low when the ink composition of the present invention is printed. In this case, it may be necessary to use it in combination with another hard resin.

(Reaction of diisocyanate compound with polymeric diol compound)
A catalyst can be used during the reaction of the diisocyanate compound with the polymeric diol compound to obtain the polyurethane polyurea resin used in the present invention.
Among these, it is preferable to use an organometallic compound. Examples of such an organometallic compound include titanium compounds such as dibutyltitanium dichloride, tetrabutyltitanium, and butoxytitanium trichloride, dibutyltin sulfide, tributyltin sulfide, tributyltin oxide, dibutyltin dichloride, dibutyltin oxide, dibutyltin dibromide, dibutyltin dimaleate, dibutyltin dilaurate, dibutyltin diacetate, dioctyltin dilaurate, and tributyltin. Examples of suitable lead compounds include tin compounds such as lead acetate, tributyltin chloride, triethyltin ethoxide, tributyltin ethoxide, dioctyltin oxide, tributyltin trichloroacetate, and tin 2-ethylhexanoate, lead compounds such as lead oleate, lead 2-ethylhexanoate, lead benzoate, and lead naphthenate, and further compounds such as iron 2-ethylhexanoate, iron acetylacetonate, cobalt benzoate, cobalt 2-ethylhexanoate, zinc naphthenate, zinc 2-ethylhexanoate, and zirconium naphthenate. Among these, titanium compounds such as tetrabutyl titanate are preferred.
Also, tertiary amine compounds can be used, such as triethylamine, triethylenediamine, 1,4-diazabicyclo(2,2,2)octane, and 1,8-diazabicyclo(5,4,0)-undecene-7 (DBU).

(Chain extension and/or end treatment reaction)
The chain extender may be any known chain extender used in polyurethane polyurea resins as ink binders. Examples of the chain extender include, among polyamine compounds, aliphatic diamines such as ethylenediamine, propylenediamine, tetramethylenediamine, and hexamethylenediamine; alicyclic diamines such as isophoronediamine and 4,4'-dicyclohexylmethanediamine; aromatic diamines such as toluylenediamine; aromatic aliphatic diamines such as xylenediamine; diamines having a hydroxyl group such as N-(2-hydroxyethyl)ethylenediamine (aminoethylethanolamine), N-(2-hydroxyethyl)propylenediamine, and N,N'-di(2-hydroxyethyl)ethylenediamine; and diol compounds such as ethylene glycol, propylene glycol, 1,4-butanediol, neopentyl glycol, diethylene glycol, and triethylene glycol.
Furthermore, polyamine compounds such as diethylenetriamine and triethylenetetramine can be used in combination within the range in which the polyurethane polyurea resin does not gel.

Examples of reaction terminators that introduce primary and secondary amino groups to the ends of the polyurethane polyurea resin include polyamine compounds such as aliphatic diamines, such as ethylenediamine, propylenediamine, tetramethylenediamine, and hexamethylenediamine, alicyclic diamines, such as isophoronediamine and 4,4'-dicyclohexylmethanediamine, polyamines, such as diethylenetriamine and triethylenetetratriamine, aromatic diamines, such as toluylenediamine, aromatic aliphatic diamines, such as xylenediamine, and diamines having hydroxyl groups, such as N-(2-hydroxyethyl)ethylenediamine (aminoethylethanolamine) and N-(2-hydroxyethyl)propylenediamine. Among these, polyamines having primary amino groups, such as diethylenetriamine and triethylenetetratriamine, are preferred.
Examples of reaction terminators that introduce hydroxyl groups into the polyurethane polyurea resin include alkanolamines such as monoethanolamine and diethanolamine, and diamines having hydroxyl groups such as N-(2-hydroxyethyl)ethylenediamine and N-(2-hydroxyethyl)propylenediamine. Also, known reaction terminators such as monoamine compounds and monoalcohol compounds can be used, and specific examples thereof include monoalkylamines such as n-propylamine and n-butylamine, dialkylamines such as di-n-butylamine, and monoalcohols such as ethanol.

(Ketimination of chain extender and/or reaction terminator)
As a method for producing the polyurethane polyurea resin used in the present invention, among the above chain extenders and/or reaction terminators, a ketimine compound obtained by previously ketiminizing a polyamine compound with an excess amount of a ketone compound is used, and a method for producing a polyurethane polyurea resin using the chain extender and/or reaction terminator is adopted. In particular, among the above chain extenders and reaction terminators, it is preferable to use one or more selected from isophoronediamine, N-(2-hydroxyethyl)ethylenediamine, and ethylenediamine.
The polyamine compound ketiminated with a ketone compound has a structure in which the oxygen atom of the ketone compound is substituted with the nitrogen atom of the amino group of the polyamine compound.
The ketone compound to be used is preferably acetone, diethyl ketone, methyl ethyl ketone, diacetone alcohol, or methyl isobutyl ketone.
In this ketiminization reaction, it is preferable not to use any solvent other than the ketone compound.
However, as a solvent other than the ketone compound, an alcohol compound can be used, and among them, isopropyl alcohol can be used.
The absence of any solvent other than the ketone compound is defined as ketiminization under solvent-free conditions. However, a polar organic solvent may be added to the mixture, instead of under solvent-free conditions, as long as it does not impede the subsequent chain extension reaction or the fact that the polyurethane polyurea resin has no odor.
The present invention relates to an ink composition containing a polyurethane polyurea resin obtained by a process of chain extension or reaction termination using a ketiminated chain extender and/or a reaction terminator, and the ink composition and printed matter printed therewith do not emit a ketimine odor. In addition, the ink composition has an effect of increasing the peel strength when laminated to a printed surface by means of extrusion lamination or the like.
The ketiminated amines and the like may be used as a chain extender, a reaction terminator, or both a chain extender and a reaction terminator.

<Synthesis of polyurethane polyurea resin from urethane prepolymer>
The urethane prepolymer obtained by the above method is subjected to a chain extension and/or reaction termination reaction with a ketimine compound to obtain the polyurethane polyurea resin of the present invention.
That is, a solvent is added, if necessary, to the reaction product of the diisocyanate compound and the polymer diol compound, and further, the ketimine chain extender and/or reaction terminator are added to carry out the reaction.
When a solvent is used, an ester-based solvent and/or an alcohol-based solvent is preferred, a mixture of an ester-based solvent and an alcohol-based solvent is more preferred, propyl acetate and isopropyl alcohol are even more preferred, and a mass ratio of propyl acetate:isopropyl alcohol in the range of 1 to 5:1 is most preferred.

In addition, when the resulting polyurethane polyurea resin has an amino group, the amine value is preferably 1 to 10 mgKOH/g. If the amine value is less than 1 mgKOH/g, the adhesion to a printing substrate when the ink composition is printed may decrease, and also when the ink composition is used as a gravure ink composition for lamination, the adhesion to a film may decrease. Furthermore, the suitability for lamination may decrease. If the amine value exceeds 10 mgKOH/g, the blocking resistance may decrease.
This amino group may be ketiminated.
In the present invention, the amine value means the amine value per 1 g of solid content, and is measured by potentiometric titration (e.g., COMTITE (AUTO TITRA)) using a 0.1 N aqueous hydrochloric acid solution.
The potassium hydroxide content is measured using a measuring device (such as a TOR COM-900, BURET B-900, or TITSTATION K-900, manufactured by Hiranuma Sangyo Co., Ltd.) and then converted into an equivalent amount of potassium hydroxide.

(Ink composition containing polyurethane polyurea resin)
The polyurethane resin obtained by the above-mentioned manufacturing method is blended, as necessary, with a colorant such as a pigment or a dye, a solvent, a filler such as silica, a vinyl chloride/vinyl acetate copolymer, a vinyl chloride/acrylic copolymer, a pigment dispersant or dispersion aid, rosin and its derivatives, chlorinated polypropylene, dammar resin, polyethylene wax, fatty acid amide, etc. to prepare an ink composition.
A known method can be used to produce an ink composition, particularly a gravure ink composition for lamination, using the necessary constituent materials. Specifically, for example, a mixture of a pigment, a binder resin, an organic solvent, and optionally a pigment dispersant, etc., is milled using a high-speed mixer, a ball mill, a sand mill, an attritor, etc., and the remaining materials such as predetermined additives are further added and mixed to obtain the composition.
A coating material containing the polyurethane polyurea resin obtained by the present invention can also be obtained by a known method for preparing a coating material, and the components usable in the ink composition described below can also be used in the coating material.

(Organic Solvent)
The solvent that may be used in the ink composition of the present invention is not particularly limited, but from the viewpoint of environmental consideration, it is preferable that the ink composition does not contain an aromatic hydrocarbon-based organic solvent. Examples of such solvents include alcohol-based organic solvents such as methanol, ethanol, n-propanol, isopropyl alcohol, and butanol; ketone-based organic solvents such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; ester-based organic solvents such as methyl acetate, ethyl acetate, propyl acetate, and butyl acetate; aliphatic hydrocarbon-based organic solvents such as n-hexane, n-heptane, and n-octane; and alicyclic hydrocarbon-based organic solvents such as cyclohexane, methylcyclohexane, ethylcyclohexane, cycloheptane, and cyclooctane. At least one of the above solvents may be used, and two or more of them may be used in combination, taking into consideration the solubility and drying properties of the binder resin. However, from the viewpoint of environmental consideration, it is preferable to suppress the use of ketone-based organic solvents among the above solvents.
Furthermore, in order to improve wetting and spreading properties, the ink composition may contain 0.1 to 20% by weight of a glycol ether organic solvent relative to 100% by weight of the organic solvent. Specific examples of glycol ether organic solvents include ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, ethylene glycol mono n-propyl ether, ethylene glycol monoisopropyl ether, diethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, ethylene glycol monoisobutyl ether, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, propylene glycol mono n-propyl ether, diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol diethyl ether, and the like.
The ink composition of the present invention may contain water in order to reduce printing defects caused by static electricity, prevent plate fogging, and improve cell reproducibility. The amount of water used in the ink composition is preferably 10% by mass or less, and more preferably in the range of 0.1 to 5.0% by mass.

(silica)
Examples of silica that can be contained in the ink composition of the present invention include natural silica, synthetic silica, crystalline silica, non-crystalline silica, hydrophobic silica, and hydrophilic silica. The silica particles preferably have an average particle size in the range of 1 to 5 μm (the average particle size of the silica particles means the particle size at 50% cumulative value (D50) in the particle size distribution, and can be determined by the Coulter counter method). The silica particles may be hydrophilic silica having a hydrophilic functional group on the surface, or may be hydrophobic silica in which the hydrophilic functional group is modified with an alkylsilane or the like to be hydrophobic. However, hydrophilic silica is preferable, and the ink containing hydrophilic silica particles has the effect of promoting wetting and spreading of the ink during overprinting, and improving the overprinting effect (hereinafter sometimes referred to as "trapping property"). The amount of silica particles used in the ink composition is 3.0% by mass or less, preferably 0.1 to 3.0% by mass, and more preferably 0.2 to 1.5% by mass. If the content is more than 3.0% by mass, the gloss tends to decrease.

(Vinyl chloride/vinyl acetate copolymers that can be blended in the ink composition of the present invention)
The vinyl chloride/vinyl acetate copolymer may be one which contains, as essential components, vinyl chloride monomer and vinyl acetate monomer which have conventionally been used in gravure ink compositions, and which is produced by a conventional known method using, as necessary, a fatty acid vinyl monomer such as vinyl propionate, vinyl monochloroacetate, vinyl versatate, vinyl laurate, vinyl stearate, vinyl benzoate, or a monomer having a functional group such as a hydroxyl group.
Among these, in the case of an environmentally friendly organic solvent-based ink, the vinyl chloride/vinyl acetate copolymer is preferably a vinyl chloride/vinyl acetate copolymer having a hydroxyl group, more preferably a vinyl chloride/vinyl acetate copolymer having 50 to 200 hydroxyl groups. Such a vinyl chloride/vinyl acetate copolymer having a hydroxyl group can be obtained by partially saponifying the acetate moiety and introducing a (meth)acrylic monomer having a hydroxyl group.
In the case of a vinyl chloride/vinyl acetate copolymer having a hydroxyl group obtained by saponifying a portion of the acetate moiety, the film properties and dissolution behavior of the resin are determined by the ratio of the constituent units based on the reactive sites of vinyl chloride in the molecule (formula 1 below), the constituent units based on the reactive sites of vinyl acetate (formula 2 below), and the constituent units based on the saponification of the reactive sites of vinyl acetate (formula 3 below). That is, the constituent units based on the reactive sites of vinyl chloride impart toughness and hardness to the resin film, the constituent units based on the reactive sites of vinyl acetate impart adhesion and flexibility, and the constituent units based on the saponification of the reactive sites of vinyl acetate impart good solubility to environmentally friendly organic solvent systems of the ink.
Formula 1 -CH ₂ -CHCl-
Formula 2 -CH ₂ -CH(OCOCH ₃ )-
Formula 3 -CH ₂ -CH(OH)-
Such vinyl chloride/vinyl acetate copolymers may be commercially available, and examples thereof include Solvine A, AL, TA5R, TA2, TA3, TAO, TAOL, C, CH, CN, and CNL manufactured by Nissin Chemical Industry Co., Ltd.
The vinyl chloride/vinyl acetate copolymer used in the ink composition of the present invention preferably has various functional groups in the molecule from the standpoint of solubility in organic solvents and printability, which will be described later.
When an environmentally friendly solvent is used as the organic solvent, the vinyl chloride/vinyl acetate copolymer preferably has 50 to 200 hydroxyl groups. As commercially available products of such vinyl chloride/vinyl acetate copolymers, for example, Solvine A, AL, TA5R, TA2, TA3, TAO, TAOL, etc. are preferably used.

(Vinyl chloride/acrylic copolymer that can be blended in the ink composition of the present invention)
The vinyl chloride/acrylic copolymer is a copolymer of vinyl chloride and an acrylic monomer as the main component. The form of the copolymer is not particularly limited, and for example, the acrylic monomer may be incorporated in the main chain of polyvinyl chloride in a block or random manner, or may be graft-copolymerized in the side chain of polyvinyl chloride.
As the acrylic monomer, a (meth)acrylic acid ester, an acrylic monomer having a hydroxyl group, etc. can be used. Examples of the (meth)acrylic acid ester include an alkyl (meth)acrylate ester, and the alkyl group may be any of linear, branched, and cyclic, but is preferably a linear alkyl group. For example, methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, cyclohexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, decyl (meth)acrylate, dodecyl (meth)acrylate, tetradecyl (meth)acrylate, hexadecyl (meth)acrylate, and octadecyl (meth)acrylate can be mentioned.
Examples of acrylic monomers having a hydroxyl group include (meth)acrylic acid hydroxyalkyl esters such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, and 8-hydroxyoctyl (meth)acrylate; glycol mono(meth)acrylates such as polyethylene glycol mono(meth)acrylate, polypropylene glycol mono(meth)acrylate, and 1,4-cyclohexanedimethanol mono(meth)acrylate; caprolactone-modified (meth)acrylate; and hydroxyethylacrylamide.
The acrylic monomer may also have a functional group other than a hydroxyl group, such as a carboxyl group, an amide bond, an amino group, or an alkylene oxide group.
The vinyl chloride/acrylic copolymer resin preferably has a weight average molecular weight of 10,000 to 70,000.
From the standpoint of solubility in environmentally friendly organic solvents and adhesion to substrates, the vinyl chloride/acrylic copolymer preferably has 50 to 200 hydroxyl groups.

In this way, in the ink composition of the present invention, a vinyl chloride/vinyl acetate copolymer and/or a vinyl chloride/acrylic copolymer can be used in combination with the polyurethane polyurea resin in order to improve adhesion, depending on the pigment to be blended.
The polyurethane polyurea resin and (vinyl chloride/vinyl acetate copolymer and/or vinyl chloride/acrylic copolymer) can be contained in a mass ratio of polyurethane polyurea resin/(vinyl chloride/vinyl acetate copolymer and/or vinyl chloride/acrylic copolymer)=100/0 to 45/55. More preferably, this mass ratio may be 95/5 to 70/30. By containing the polyurethane polyurea resin and the vinyl chloride/vinyl acetate copolymer and/or vinyl chloride/acrylic copolymer in such a ratio, the ink composition of the present invention has excellent printability and adhesion to films. Furthermore, when lamination processing is performed, it has even better lamination suitability.
When the ratio of the polyurethane polyurea resin to the vinyl chloride/vinyl acetate copolymer and/or the vinyl chloride/acrylic copolymer is less than 45/55, the proportion of the vinyl chloride/vinyl acetate copolymer and/or the vinyl chloride/acrylic copolymer becomes high, and the printed matter formed using the ink composition of the present invention becomes hard, and the adhesion to the film may also become insufficient.

(Pigment dispersants that can be used in combination with the ink composition of the present invention)
The pigment dispersant that can be used in combination is a polyester-based pigment dispersant that can be generally used in gravure ink compositions containing an organic solvent, specifically, AJISPER PB821, PB822, PB824, PB881 (manufactured by Ajinomoto Fine-Techno Co., Ltd.), Solsperse 24000, 56000 (manufactured by Lubrizol Nippon), etc., among which, a basic group-containing polyester-based polymer dispersant can be preferably used.
The content of the pigment dispersant is usually preferably from 1 to 200 parts by mass, and more preferably from 1 to 60 parts by mass, based on 100 parts by mass of the total pigment.

(Other ingredients that can be used together)
The ink composition of the present invention preferably contains at least one selected from the group consisting of rosin and its derivatives, dammar resin, chlorinated polypropylene, silica, polyethylene wax, and fatty acid amides.
Rosin and its derivatives, chlorinated polypropylene, and dammar resin are used to improve adhesion to various films and lamination suitability, and it is preferable to contain one or more of these.
Silica, polyethylene wax, and fatty acid amide are used to improve trapping properties and blocking resistance, and it is preferred to contain one or more of these, and preferably two or more of them.

(Rosin and its derivatives)
Examples of rosin include gum rosin, tall oil rosin, wood rosin, etc. Generally, rosin is an amber-colored, amorphous resin obtained from pine trees, and since it is obtained naturally, it is a mixture, but it may be used after being isolated into its constituent components, namely abietic acid, neoabietic acid, palustric acid, pimaric acid, isopimaric acid, sandaracopimaric acid, and dehydroabietic acid, and these are also defined as rosin in the present invention.
The rosin derivatives are compounds obtained by modifying the above-mentioned rosins, and specific examples thereof are listed below.
(1) Hydrogenated rosin: A rosin whose weather resistance has been improved by adding hydrogen to the conjugated double bonds (hydrogenation).
(2) Disproportionated rosin: Disproportionation is a modification in which two molecules of rosin react with each other, and two molecules of abietic acid with conjugated double bonds become aromatic, while the other becomes a molecule with a single double bond. In general, it is less weather-resistant than hydrogenated rosin, but is better than untreated rosin.
(3) Rosin-modified phenolic resin: Rosin-modified phenolic resin is often used as the main binder in offset printing inks. Rosin-modified phenolic resin can be obtained by a known manufacturing method.
(4) Rosin ester: an ester resin derived from rosin, which has long been used as a tackifier for adhesives and pressure sensitive adhesives.
(5) Rosin-modified maleic acid resin: a resin obtained by addition reaction of rosin with maleic anhydride, and optionally including a resin obtained by grafting a hydroxyl-containing compound such as glycerin with the anhydride group through esterification.
(6) Polymerized rosin: A derivative containing dimerized resin acid derived from natural resin rosin.
In addition, known rosins and rosin derivatives can also be used, and these can be used alone or in combination.
Furthermore, the acid value of the rosin and rosin derivative is preferably 120 mgKOH/g or more. When the acid value is 120 mgKOH/g or more, the laminate strength is improved. The acid value is more preferably 160 mgKOH/g or more. The total amount of the rosin and rosin derivative used is 3.0 mass% or less, preferably 0.1 to 3.0 mass%, in terms of solid mass% of the ink composition of the present invention.

(Chlorinated polypropylene)
The chlorinated polypropylene may have a chlorination degree of 20 to 50. A chlorinated polypropylene having a chlorination degree of less than 20 tends to have a decreased compatibility with organic solvents. On the other hand, when the chlorination degree exceeds 50, the chlorinated polypropylene tends to have a decreased adhesiveness to films. The chlorination degree is defined as the mass % of chlorine atoms in the chlorinated polypropylene resin. The chlorinated polypropylene is preferably a modified or unmodified chlorinated polypropylene having a weight average molecular weight of 5,000 to 200,000. When the weight average molecular weight is less than 5,000, the chlorinated polypropylene tends to have a decreased adhesiveness. On the other hand, when the weight average molecular weight exceeds 200,000, the chlorinated polypropylene tends to have a decreased solubility in organic solvents. The amount of the chlorinated polypropylene used is 3.0 mass % or less, preferably 0.1 to 3.0 mass %, in terms of the solid mass % of the ink composition of the present invention.

(Dammar resin)
Dammar resin, also written as damar or dammar, is a type of natural resin derived from plants. More specifically, it is a type of natural resin obtained from Dipterocarpaceae or Burseraceae plants growing in Southeast Asia such as Malaysia and Indonesia. When used, it is dissolved in an appropriate organic solvent to form a varnish. Since dammar resin does not contain chlorine, it is possible to eliminate or reduce chlorine compared to the case where a chlorinated polyolefin resin is used in the ink composition. The amount of dammar resin used is 3.0 mass % or less, preferably 0.1 to 3.0 mass %, in terms of solid mass % of the ink composition of the present invention.

(Polyethylene wax)
The polyethylene wax used has an average particle size in the range of 1.0 to 3.0 μm (the average particle size means the particle size measured by #1 Microtrac UPA manufactured by Honeywell). If the particle size of the polyethylene wax is smaller than 1.0 μm, the slipping property and blocking property decrease, and if the particle size is larger than 3.0 μm, the trapping property decreases. The content of the polyethylene wax in the ink composition of the present invention is preferably 1.5% by mass or less, and preferably in the range of 0.1 to 1.5% by mass. If the content is more than 1.5% by mass, the gloss tends to decrease.

(Fatty acid amide)
The fatty acid amide is not particularly limited as long as it has a fatty acid residue and an amide group. Examples of the fatty acid amide include monoamide, substituted amide, bisamide, methylol amide, and ester amide, and at least one selected from the group consisting of monoamide, substituted amide, and bisamide is preferable because it improves blocking resistance. The amount of the fatty acid amide used in the ink composition of the present invention is 1% by mass or less, preferably in the range of 0.01 to 1% by mass.

Monoamide: Monoamide is represented by the following general formula (1):
General formula (1) R1-CONH ₂
(In the formula, R1 represents a residue obtained by removing COOH from a fatty acid.)
Specific examples of monoamides include lauric acid amide, palmitic acid amide, stearic acid amide, behenic acid amide, hydroxystearic acid amide, oleic acid amide, and erucic acid amide.
Substituted amide: The substituted amide is represented by the following general formula (2):
General formula (2) R2-CONH-R3
(In the formula, R2 and R3 represent a residue obtained by removing COOH from a fatty acid, and may be the same or different.)
Specific examples of the substituted amide include N-oleyl palmitic acid amide, N-stearyl stearic acid amide, N-stearyl oleic acid amide, N-oleyl stearic acid amide, and N-stearyl erucic acid amide.

Bisamide: Bisamide is represented by the following general formula (3) or general formula (4).
General formula (3) R4-CONH-R5-HNCO-R6
General formula (4) R7-NHCO-R8-CONH-R9
(In the formula, R4, R6, R7, and R9 represent a residue obtained by removing COOH from a fatty acid and may be the same or different, and R5 and R8 represent an alkylene group or an arylene group having 1 to 10 carbon atoms.)
Specific examples of bisamides include methylene bisstearic acid amide, ethylene biscapric acid amide, ethylene bislauric acid amide, ethylene bisstearic acid amide, ethylene bishydroxystearic acid amide, ethylene bisbehenic acid amide, hexamethylene bisstearic acid amide, hexamethylene bisbehenic acid amide, hexamethylene hydroxystearic acid amide, ethylene bisoleic acid amide, ethylene biserucic acid amide, hexamethylene bisoleic acid amide, N,N'-distearyl adipamide, N,N'-distearyl sebacic acid amide, N,N'-dioleyl adipamide, and N,N'-dioleyl sebacic acid amide.

Methylolamide: Methylolamide is represented by the following general formula (5).
General formula (5) R10-CONHCH ₂ OH
(In the formula, R10 represents a residue obtained by removing COOH from a fatty acid.)
Specific examples of methylol amides include methylol palmitic acid amide, methylol stearic acid amide, methylol behenic acid amide, methylol hydroxystearic acid amide, methylol oleic acid amide, and methylol erucic acid amide.

Ester amide: Ester amide is represented by the following general formula (6):
General formula (6) R11-CONH-R12-OCO-R13
(In the formula, R11 and R13 represent a residue obtained by removing COOH from a fatty acid and may be the same or different, and R12 represents an alkylene group or arylene group having 1 to 10 carbon atoms.)
Specific examples of ester amides include stearamide ethyl stearate, oleamide ethyl urearate, and the like.
The melting point of the fatty acid amide is preferably 50 to 150°C.
Moreover, the fatty acid constituting the fatty acid amide is preferably a saturated fatty acid having 12 to 22 carbon atoms and/or an unsaturated fatty acid having 16 to 25 carbon atoms, and more preferably a saturated fatty acid having 16 to 18 carbon atoms and/or an unsaturated fatty acid having 18 to 22 carbon atoms. Particularly preferred saturated fatty acids are lauric acid, palmitic acid, stearic acid, behenic acid, and hydroxystearic acid, and particularly preferred unsaturated fatty acids are oleic acid and erucic acid.
In addition, nitrocellulose, cellulose acetate propionate resin, and cellulose acetate butyrate resin may be contained in the ink composition for the purpose of improving blocking resistance.

(nitrocellulose)
As the soluble nitrocellulose, soluble nitrocellulose that has been used in gravure ink compositions can be used. The soluble nitrocellulose is obtained by reacting natural cellulose with nitric acid to replace three hydroxyl groups in a six-membered ring of an anhydrous glucopyranose group in the natural cellulose with nitric acid groups to form a nitric acid ester. As the soluble nitrocellulose used in the present invention, one having a nitrogen content of 10 to 13% and an average degree of polymerization of 35 to 90 is preferably used. Specific examples include SS1/2, SS1/4, SS1/8, TR1/16, NC RS-2, (KCNC, manufactured by KOREA CNC LTD), and the like. The amount of soluble nitrocellulose used in the ink composition of the present invention is preferably in the range of 2.0% by mass or less.

(Cellulose acetate propionate resin)
As the cellulose acetate propionate resin, a cellulose acetate propionate resin that has been conventionally used in gravure ink compositions can be used.
The cellulose acetate propionate resin is obtained by triesterifying cellulose with acetic acid and propionic acid, followed by hydrolysis. Generally, resins with acetyl groups of 0.6 to 2.5% by weight, propionate groups of 42 to 46% by weight, and hydroxyl groups of 1.8 to 5% by weight are commercially available. The amount of the cellulose acetate propionate resin used in the ink composition of the present invention is preferably in the range of 3.0% by weight or less.

(Cellulose acetate butyrate resin)
As the cellulose acetate butyrate resin, a cellulose acetate butyrate resin that has been conventionally used in gravure ink compositions can be used.
Cellulose acetate butyrate resin is obtained by triesterification with acetic acid and butyric acid, followed by hydrolysis. Generally, resins with 2 to 30% by weight of acetyl groups, 17 to 53% by weight of butyryl groups, and 1 to 5% by weight of hydroxyl groups are commercially available. The amount of cellulose acetate butyrate resin used in the ink composition of the present invention is preferably in the range of 0.1 to 3.0% by weight.

(Other materials)
The ink composition of the present invention may further contain various additives such as an antistatic agent and a plasticizer.

[Method for producing a laminate print using the ink composition of the present invention]
Next, a method for obtaining a laminate print using the ink composition of the present invention will be described. The polyurethane polyurea resin obtained by the present invention can be used for applications other than lamination and gravure printing.
The method for obtaining a laminate print includes at least the following printing method. For example, a gravure ink composition for lamination is printed at least once on a resin film that is a known substrate for lamination by gravure printing. Next, another ink composition for gravure lamination printing is printed by gravure printing at an arbitrary position on the surface side of the printing ink layer for gravure lamination formed by these printings (the lower layer side from the surface layer after final lamination), and then dried by a dryer.
A resin film or the like can be laminated by various methods on the layer of the ink composition for gravure laminate printing of the printed matter obtained by the above method to obtain a laminated printed matter for packaging bags, etc. Examples of the lamination method that can be used include an extrusion lamination method in which an anchor coating agent is applied to the surface of the printed matter and then a molten polymer is laminated thereon, and a dry lamination method in which an adhesive is applied to the surface of the printed matter and then a film-like polymer is laminated thereon.

The above-mentioned extrusion lamination method is a method in which an anchor coating agent such as a titanium-based, urethane-based, imine-based, polybutadiene-based agent is applied, as necessary, to the surface of a printed material containing a layer of an ink composition, and then a molten polymer is laminated using a known extrusion laminator. Furthermore, the molten resin can be laminated in a sandwich shape with other materials as an intermediate layer.
The molten polymer used in the extrusion lamination method may be a resin that has been conventionally used, such as low-density polyethylene, ethylene-vinyl acetate copolymer, polypropylene, etc. Among these, the effect of the present invention is enhanced when low-density polyethylene, which is easily oxidized during melting to generate carbonyl groups, is used.

The dry lamination method is a method in which a urethane-based, isocyanate-based or other adhesive is applied to the surface of the layer of the gravure laminate printing ink composition, and then a film-like polymer is laminated using a known dry lamination machine. Polyethylene, non-oriented polypropylene, etc. can be used as the resin for the film used in the dry lamination method. In particular, in order to obtain a packaging material for retort applications, aluminum foil can be sandwiched between the substrate and the resin film to be laminated and laminated. Such a laminated product can also be used for boiling and retort applications after being made into a bag and filled with the contents.
Examples of the resin film used in this case include oriented and unoriented polyolefins such as polyethylene and polypropylene, polyester, nylon, cellophane, vinylon, etc. Furthermore, with regard to these resin films, films obtained by processing in advance such as coating or kneading an anti-fogging agent, or surface coating or kneading a matting agent can also be used.

The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. Unless otherwise specified, "%" means "% by mass" and "parts" means "parts by mass." The figures for the amounts of each material in the tables are also "parts by mass." The unit of acid value is mgKOH/g.

<Method of producing ketimine solution 1>
51 parts of isophoronediamine, 31.2 parts of aminoethylethanolamine, and 174 parts of acetone were mixed and stirred at room temperature for 1 hour, to obtain Ketimine Solution 1.
<Method of producing ketimine solution 2>
51 parts of isophoronediamine, 31.2 parts of aminoethylethanolamine, and 258 parts of diethyl ketone were mixed and stirred at room temperature for 1 hour, to obtain a ketimine solution 2.
<Method of producing ketimine solution 3>
36 parts of ethylenediamine and 174 parts of acetone were mixed and stirred at room temperature for 1 hour to obtain Ketimine Solution 3.
<Method of producing ketimine solution 4>
51 parts of isophoronediamine, 31.2 parts of aminoethylethanolamine, and 300 parts of methyl isobutyl ketone were mixed and stirred at room temperature for 1 hour, to obtain Ketimine Solution 4.
<Method of producing ketimine solution 5>
51 parts of isophoronediamine, 31.2 parts of aminoethylethanolamine, and 177 parts of a mixed liquid of acetone/isopropyl alcohol = 3:7 (mass ratio) were mixed and stirred at room temperature for 1 hour, to obtain Ketimine Solution 5.

<Method of producing PU-1 (ketiminization with acetone)>
A four-neck flask equipped with a stirrer, a cooling tube, and a nitrogen gas inlet tube was charged with 400 parts of 3-methyl-1,5-pentylene adipate diol having an average molecular weight of 4000, 33.3 parts of isophorone diisocyanate, and 0.04 parts of tetrabutyl titanate, and reacted for 6 hours at 90 to 100° C. while introducing nitrogen gas. After adding 810 parts of propyl acetate and 202 parts of isopropyl alcohol, the mixture was cooled to near room temperature, and 25.6 parts of Ketimine Solution 1 was added and stirred for 30 minutes to obtain PU-1 (solid content 30% by mass).

<Method of producing PU-2 (ketiminization with acetone)>
A four-neck flask equipped with a stirrer, a cooling tube, and a nitrogen gas inlet tube was charged with 400 parts of 3-methyl-1,5-pentylene adipate diol having an average molecular weight of 4000, 100 parts of polypropylene glycol having an average molecular weight of 2000, 49.9 parts of isophorone diisocyanate, and 0.05 parts of tetrabutyl titanate, and reacted for 6 hours at 90 to 100 ° C. while introducing nitrogen gas. After adding 1029 parts of propyl acetate and 257 parts of isopropyl alcohol, the mixture was cooled to near room temperature, and 38.4 parts of ketimine solution 1 was added and stirred for 30 minutes to obtain PU-2 (solid content 30% by mass).

<Production method of PU-3 (ketiminization with diethyl ketone)>
A four-neck flask equipped with a stirrer, a cooling tube, and a nitrogen gas inlet tube was charged with 400 parts of 3-methyl-1,5-pentylene adipate diol having an average molecular weight of 4000, 33.3 parts of isophorone diisocyanate, and 0.04 parts of tetrabutyl titanate, and reacted for 6 hours at 90 to 100° C. while introducing nitrogen gas. After adding 803 parts of propyl acetate and 200 parts of isopropyl alcohol, the mixture was cooled to near room temperature, and 34 parts of ketimine solution 2 was added and stirred for 30 minutes to obtain PU-3 (solid content 30% by mass).

<Production method of PU-4 (ketiminization with acetone)>
A four-neck flask equipped with a stirrer, a cooling tube, and a nitrogen gas inlet tube was charged with 400 parts of 3-methyl-1,5-pentylene adipate diol having an average molecular weight of 4000, 40.0 parts of isophorone diisocyanate, and 0.04 parts of tetrabutyl titanate, and reacted for 6 hours at 90 to 100° C. while introducing nitrogen gas. After adding 823 parts of propyl acetate and 206 parts of isopropyl alcohol, the mixture was cooled to near room temperature, and 41 parts of Ketimine Solution 1 was added and stirred for 30 minutes to obtain PU-4 (solid content 30% by mass).

<Production method of PU-5 (ketiminization with acetone)>
A four-neck flask equipped with a stirrer, a cooling tube, and a nitrogen gas inlet tube was charged with 400 parts of 3-methyl-1,5-pentylene adipate diol having an average molecular weight of 4000, 33.3 parts of isophorone diisocyanate, and 0.04 parts of tetrabutyl titanate, and reacted for 6 hours at 90 to 100° C. while introducing nitrogen gas. After adding 810 parts of propyl acetate and 202 parts of isopropyl alcohol, the mixture was cooled to near room temperature, and 29.9 parts of Ketimine Solution 1 was added and stirred for 30 minutes to obtain PU-5 (solid content 30% by mass).

<Production method of PU-6 (ketiminization with acetone)>
A four-neck flask equipped with a stirrer, a cooling tube, and a nitrogen gas inlet tube was charged with 400 parts of polypropylene glycol having an average molecular weight of 4000, 33.3 parts of isophorone diisocyanate, and 0.04 parts of tetrabutyl titanate, and reacted for 6 hours at 90 to 100° C. while introducing nitrogen gas. After adding 810 parts of propyl acetate and 202 parts of isopropyl alcohol, the mixture was cooled to near room temperature, and 25.6 parts of ketimine solution 1 was added and stirred for 30 minutes to obtain PU-6 (solid content 30% by mass).

<Production method of PU-7 (ketiminization with acetone)>
A four-neck flask equipped with a stirrer, a cooling tube, and a nitrogen gas inlet tube was charged with 400 parts of 3-methyl-1,5-pentylene adipate diol having an average molecular weight of 4000, 36.6 parts of tetramethyl xylylene diisocyanate, and 0.09 parts of tetrabutyl titanate, and reacted for 6 hours at 100 to 110° C. while introducing nitrogen gas. After adding 816 parts of propyl acetate and 204 parts of isopropyl alcohol, the mixture was cooled to near room temperature, and 25.6 parts of ketimine solution 1 was added and stirred for 30 minutes to obtain PU-7 (solid content 30% by mass).

<Production method of PU-8 (ketiminization with acetone)>
A four-neck flask equipped with a stirrer, a cooling tube, and a nitrogen gas inlet tube was charged with 400 parts of 3-methyl-1,5-pentylene adipate diol having an average molecular weight of 4000, 31.5 parts of isophorone diisocyanate, and 0.04 parts of tetrabutyl titanate, and reacted for 6 hours at 90 to 100° C. while introducing nitrogen gas. After adding 802 parts of propyl acetate and 200 parts of isopropyl alcohol, the mixture was cooled to near room temperature, and 21 parts of Ketimine Solution 3 was added and stirred for 30 minutes to obtain PU-8 (solid content 30% by mass).

<PU-9 manufacturing method (chain extension with diamine)>
A four-neck flask equipped with a stirrer, a cooling tube, and a nitrogen gas inlet tube was charged with 400 parts of 3-methyl-1,5-pentylene adipate diol having an average molecular weight of 4000, 33.3 parts of isophorone diisocyanate, and 0.04 parts of tetrabutyl titanate, and reacted for 6 hours at 90 to 100° C. while introducing nitrogen gas. After adding 824 parts of propyl acetate and 206 parts of isopropyl alcohol, the mixture was cooled to near room temperature, and 5.1 parts of isophorone diamine and 3.1 parts of aminoethylethanolamine were added and stirred for 30 minutes to obtain PU-9 (solid content 30% by mass).

<Production method of PU-10 (ketiminization with methyl isobutyl ketone)>
A four-neck flask equipped with a stirrer, a cooling tube, and a nitrogen gas inlet tube was charged with 400 parts of 3-methyl-1,5-pentylene adipate diol having an average molecular weight of 4000, 33.3 parts of isophorone diisocyanate, and 0.04 parts of tetrabutyl titanate, and reacted for 6 hours at 90 to 100° C. while introducing nitrogen gas. After adding 800 parts of propyl acetate and 200 parts of isopropyl alcohol, the mixture was cooled to near room temperature, and 38.2 parts of Ketimine Solution 4 was added and stirred for 30 minutes to obtain PU-10 (solid content 30% by mass).

<Production method of PU-11 (dilution with another solvent during ketiminization)>
A four-neck flask equipped with a stirrer, a cooling tube, and a nitrogen gas inlet tube was charged with 400 parts of 3-methyl-1,5-pentylene adipate diol having an average molecular weight of 4000, 33.3 parts of isophorone diisocyanate, and 0.04 parts of tetrabutyl titanate, and reacted for 6 hours at 90 to 100° C. while introducing nitrogen gas. After adding 810 parts of propyl acetate and 203 parts of isopropyl alcohol, the mixture was cooled to near room temperature, and 17.7 parts of Ketimine Solution 5 was added and stirred for 30 minutes to obtain PU-11 (solid content 30% by mass).

<Production method of PU-12 (ketiminization with acetone)>
A four-neck flask equipped with a stirrer, a cooling tube, and a nitrogen gas inlet tube was charged with 400 parts of 3-methyl-1,5-pentylene adipate diol having an average molecular weight of 5000, 28.4 parts of isophorone diisocyanate, and 0.08 parts of tetrabutyl titanate, and reacted for 6 hours at 90 to 100° C. while introducing nitrogen gas. After adding 801 parts of propyl acetate and 200 parts of isopropyl alcohol, the mixture was cooled to near room temperature, and 24.6 parts of Ketimine Solution 1 was added and stirred for 30 minutes to obtain PU-12 (solid content 30% by mass).

<Method of producing PU-13>
PU-13 (solid content 30 mass %) was obtained by the same production method as PU-1, except that the condensate of 3-methyl-1,5-pentylene adipate diol having an average molecular weight of 4,000 was changed to a polyester polyol having an average molecular weight of 4,000 polymerized using 1,4-butanediol/neopentyl glycol = 50/50 (molar ratio) as the diol component and adipic acid as the dicarboxylic acid component.

<Method of producing PU-14>
PU-14 (solid content 30 mass%) was obtained by the same production method as PU-1, except that the condensate of 3-methyl-1,5-pentylene adipate diol having an average molecular weight of 4,000 was changed to a polyester polyol having an average molecular weight of 4,000 polymerized using 1,4-butanediol/2-methyl-1,3-propanediol = 50/50 (molar ratio) as the diol component and adipic acid as the dicarboxylic acid component.

<Method of producing PU-15>
PU-15 (solid content 30 mass %) was obtained by the same production method as PU-1, except that the condensate of 3-methyl-1,5-pentylene adipate diol having an average molecular weight of 4,000 was changed to a polyester polyol having an average molecular weight of 4,000 polymerized using diethylene glycol/neopentyl glycol = 50/50 (molar ratio) as the diol component and adipic acid as the dicarboxylic acid component.

<Method of producing PU-16>
PU-16 (solid content 30 mass %) was obtained by the same production method as PU-1, except that the condensate of 3-methyl-1,5-pentylene adipate diol having an average molecular weight of 4,000 was changed to a polyester polyol having an average molecular weight of 4,000 polymerized using diethylene glycol/2-methyl-1,3-propanediol = 40/60 (molar ratio) as the diol component and adipic acid as the dicarboxylic acid component.

<Method of producing PU-17>
PU-17 (solid content 30 mass %) was obtained by the same production method as PU-1, except that the condensate of 3-methyl-1,5-pentylene adipate diol having an average molecular weight of 4,000 was changed to a polyester polyol having an average molecular weight of 4,000 polymerized using 2-methyl-1,3-propanediol as the diol component and sebacic acid/succinic acid = 40/60 (molar ratio) as the dicarboxylic acid component.

<Method of producing PU-18>
PU-18 (solid content 30 mass %) was obtained by the same production method as PU-1, except that the condensate of 3-methyl-1,5-pentylene adipate diol having an average molecular weight of 4,000 was changed to a polyester polyol having an average molecular weight of 4,000 polymerized using diethylene glycol as the diol component and sebacic acid/succinic acid = 35/65 (molar ratio) as the dicarboxylic acid component.

<Method of producing PU-19>
PU-19 (solid content 30 mass %) was obtained by the same production method as in PU-1, except that the condensate of 3-methyl-1,5-pentylene adipate diol having an average molecular weight of 4,000 was changed to a polyester polyol having an average molecular weight of 4,000 polymerized using 1,3-propanediol as the diol component and dimer acid/succinic acid = 20/80 (molar ratio) as the dicarboxylic acid component.

<Method of producing PU-20>
PU-20 (solid content 30 mass %) was obtained by the same production method as PU-1, except that the condensate of 3-methyl-1,5-pentylene adipate diol having an average molecular weight of 4000 was changed to a polyester polyol having an average molecular weight of 4000 polymerized using diethylene glycol as the diol component and dimer acid/succinic acid = 20/80 (molar ratio) as the dicarboxylic acid component.

<Method of producing PU-21>
PU-21 (solid content 30 mass%) was obtained by the same production method as PU-1, except that the condensate of 3-methyl-1,5-pentylene adipate diol having an average molecular weight of 4,000 was changed to a polyester polyol having an average molecular weight of 4,000 polymerized using 1,4-butanediol as the diol component and azelaic acid/succinic acid = 50/50 (molar ratio) as the dicarboxylic acid component.

<Method of producing PU-22>
PU-22 (solid content 30 mass%) was obtained by the same production method as PU-1, except that the condensate of 3-methyl-1,5-pentylene adipate diol having an average molecular weight of 4,000 was changed to a polyester polyol having an average molecular weight of 4,000 polymerized using 2,5-hexanediol as the diol component and azelaic acid/succinic acid = 40/60 (molar ratio) as the dicarboxylic acid component.

(Pigment)
Titanium oxide (R-960, manufactured by DuPont)
Phthalocyanine Blue (Pigment Blue 15:4)
(Silica particles)
Silica particles with an average particle size of 4.5 μm

<Production Examples of Ink Compositions in Examples and Comparative Examples>
The pigment, polyurethane resin varnish (PU-1 to PU-22), silica and solvent were kneaded using a paint conditioner manufactured by Red Devil Co., Ltd., to obtain the ink compositions of the examples and comparative examples shown in Table 1.

<Printing>
100 parts by mass of each of the ink compositions of the Examples and Comparative Examples was diluted with a mixed solvent (ethyl acetate/propyl acetate/isopropyl alcohol = 50/25/25, mass ratio), and the viscosity was adjusted to 15 seconds using a Zahn Cup No. 3 manufactured by Rigo Co., Ltd. Using a gravure printing machine, each of the diluted ink compositions was printed on the treated surface of each film under the following conditions, followed by drying to obtain a printed matter. The obtained printed matter was also used to evaluate the amine odor. The specific evaluation method is shown below.
(Printing method/printing conditions)
Printing room environment: Temperature 25°C, humidity 50%
Coating machine: Gravure printing machine
Coating speed: 150 m/min
Printing plate: Direct 175 lines 28 μm Solid plate Drying temperature: 55° C.

(Various films)
OPP: Corona discharge treated biaxially oriented polypropylene film, Toyobo P-216
1. Thickness: 25 μm
PET (film): Polyethylene terephthalate film with corona discharge treatment on one side, manufactured by Toyobo Co., Ltd., E-5102, thickness 12 μm
NY: Nylon film, Toyobo Co., Ltd., N-1102, thickness 15 μm

(Amine odor on printed matter)
The odor of each of the printed materials was evaluated by a sensory test, in which the nose was placed against the printed surface of the printed material. The results are shown in Table 1.
A: No amine odor is observed.
Δ: A slight amine odor is observed.
×: Amine odor is observed.

(Extrusion Laminate Strength)
For each printed matter in the Examples and Comparative Examples, a polyethyleneimine-based anchor coating agent (Epomin P-1000, Nippon Shokubai Co., Ltd.) was used for the OPP system, and an isocyanate-based anchor coating agent (Takelac A-3210 and Takenate A-3070, Mitsui Chemicals, Inc.) was used for the PET and NY systems, and molten polyethylene was laminated using an extrusion laminator to obtain a laminated product. These laminated products were cut to a width of 15 mm after aging at 40°C for 1 day, and the T-peel strength was measured as the extrusion laminate strength using a peel tester (manufactured by Yasuda Seiki Seisakusho Co., Ltd.). The results are shown in Table 1.
<Evaluation criteria>
The actual measured values of extrusion laminate strength (g/15 mm) are shown. ">500" indicates that it exceeded 500 g/15 mm.

The ink compositions of Examples 1 to 20, which used ketiminated polyurethane polyurea resins, did not have an amine odor. In addition, the extrusion laminate films obtained by extrusion laminating the printed surfaces formed on various films had higher lamination strength.
However, Comparative Example 1, in which only polypropylene glycol was used as the diol compound, and Comparative Example 2, in which tetramethylxylylene diisocyanate was used as the isocyanate compound, only showed lower extrusion laminate strength compared to the results of the Examples in which the same printed film was used.
Furthermore, in Comparative Examples 3 and 4, in which a non-ketimine polyurethane polyurea resin was used, the printed matter had an amine odor.

Claims (3)

An organic solvent-based ink composition containing a polyurethane polyurea resin obtained by reacting a diisocyanate compound with a polymeric diol compound,
The diisocyanate compound contains isophorone diisocyanate, and the polymeric diol compound is at least one selected from the following a to l:
a. 3-methyl-1,5-pentylene adipate diol having a number average molecular weight of 1,000 to 8,000 obtained by a condensation reaction of adipic acid and 3-methyl-1,5-pentanediol;
b. A condensate having a number average molecular weight of 1,000 to 8,000 obtained by a condensation reaction of adipic acid with 1,4-butanediol/neopentyl glycol = 20/80 to 80/20 (molar ratio),
c. A condensate having a number average molecular weight of 1,000 to 8,000 obtained by a condensation reaction of adipic acid with 1,4-butanediol/2-methyl-1,3-propanediol (molar ratio: 20/80 to 80/20);
d. A condensate having a number average molecular weight of 1,000 to 8,000 obtained by a condensation reaction of adipic acid with diethylene glycol/neopentyl glycol = 20/80 to 80/20 (molar ratio),
e. A condensate having a number average molecular weight of 1,000 to 8,000 obtained by a condensation reaction of adipic acid with diethylene glycol/2-methyl-1,3-propanediol = 20/80 to 80/20 (molar ratio),
f. A condensate having a number average molecular weight of 1,000 to 8,000 obtained by condensation reaction of sebacic acid/succinic acid = 20/80 to 80/20 (molar ratio) with 2-methyl-1,3-propanediol,
g. A condensation product having a number average molecular weight of 1,000 to 8,000 obtained by condensation reaction of sebacic acid/succinic acid = 20/80 to 80/20 (molar ratio) with diethylene glycol,
h. A condensate having a number average molecular weight of 1,000 to 8,000 obtained by condensation reaction of dimer acid/succinic acid = 20/80 to 80/20 (molar ratio) with 1,3-propanediol,
i. A condensate having a number average molecular weight of 1,000 to 8,000 obtained by condensation reaction of dimer acid/succinic acid=20/80 to 80/20 (molar ratio) with diethylene glycol,
j. A condensate having a number average molecular weight of 1,000 to 8,000 obtained by condensation reaction of azelaic acid/succinic acid = 20/80 to 80/20 (molar ratio) with 1,4-butanediol,
k. A condensate having a number average molecular weight of 1,000 to 8,000 obtained by condensation reaction of azelaic acid/succinic acid = 20/80 to 80/20 (molar ratio) with 2,5-hexanediol,
l. 3-methyl-1,5-pentylene adipate diol having a number average molecular weight of 1,000 to 4,000,
Polyurethane polyurea resin is an ink composition having a ketiminated amino group.
(However, this does not include cases where the ink composition is an epoxy resin composition, and further, cases where it is a two-component curing type are excluded.) The ink composition according to claim 1, wherein the ketiminated amino group is ketiminated with acetone and/or diethyl ketone. The ink composition according to claim 1 or 2, in which the polyurethane polyurea resin is a urethane prepolymer whose chains have been extended, and the sites originating from the chain extender within the molecule have been ketiminated.