Organic solvent-based high-solids ink composition for gravure printing and gravure printing method

Abstract

To provide a high solid ink composition for organic solvent-based gravure printing which is reduced in odor, has good temporal stability, and has good printing density, printability and laminate suitability even when used for gravure printing using a shallowed printing plate, and a gravure printing method using the ink composition.SOLUTION: A high solid ink composition for organic solvent-based gravure printing contains a pigment, a binder resin and an organic solvent, where the pigment is an organic pigment and / or an inorganic pigment, the binder resin contains a specific polyurethane polyurea resin, and the pigment in the high solid ink composition for organic solvent-based gravure printing has a specific ratio.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a high-solid ink composition for solvent-based gravure printing and a gravure printing method.

Background Art

[0002] Recently, addressing environmental issues has become a business theme that all industries and all business types should tackle as a social responsibility. Of course, the field of plastic film printing is no exception. However, for printing on plastic films, inks containing a large amount of organic solvents are generally used due to printing suitability constraints, which impose a significant burden on the environment. Therefore, manufacturers of inks and printed products are working on solving environmental problems by reducing the discharge amount of organic solvents and developing simple treatment methods.

[0003] One such effort is that ink manufacturers are attempting to reduce the more environmentally burdensome organic solvents contained in inks. For example, conventionally, the content of highly environmentally burdensome organic solvents such as aromatic and ketone solvents contained in inks has been reduced. Furthermore, in recent years, not only the types and composition ratios of the organic solvents to be replaced, but also the entire materials used in inks, such as binder resins and additives, have been reviewed. As a result, ester-alcohol-based inks that contain little or no aromatic or ketone solvents have been put into practical use.

[0004] On the other hand, printing companies are attempting to minimize the discharge of organic solvents in inks into the atmosphere during printing as a solution to the above environmental problems. As an example, by reducing the depth of the gravure printing plate (cell depth) (shallow plate) and printing, an attempt is made to reduce the amount of ink used during printing and the volatilization amount of organic solvents into the atmosphere (see, for example, Patent Document 1). However, as gravure printing plates become shallower, the cell volume decreases, and the amount of ink composition transferred during printing decreases. Consequently, although the amount of organic solvent in the ink composition can be reduced, the amount of colorant in the ink film also decreases due to the reduced ink transfer, which leads to the problem of not being able to obtain sufficient print (color) density. Therefore, in order to form a thin film and a high-pigment concentration film during printing, printing was usually performed using an ink composition with a high pigment concentration.

[0005] However, increasing the pigment concentration in the ink composition increases ink viscosity, which relatively tends to lead to a decrease in plate coverage and doctor blade breakage. To prevent such ink compositions from becoming highly viscous, methods are known to reduce the amount of other solid components. However, such methods lead to a reduction in the amount of binder resin in the ink composition. This, in turn, lowers the ratio of binder resin to pigment, and consequently reduces the cohesive force of the ink film. To address this, the applicant has proposed a high-solid ink composition for organic solvent-based gravure printing using a low-viscosity polyurethane polyurea resin having primary and / or secondary amino groups at its terminals as a binder resin (see, for example, Patent Document 3). However, when using a low-viscosity polyurethane polyurea resin, it is necessary to lower the molecular weight of the polyurethane polyurea resin. When polyurethane polyurea resin is prepared by conventional methods, a large amount of free amines are generated, and high-solid ink compositions for organic solvent-based gravure printing using this resin have the problem of generating odor. Furthermore, high-solid ink compositions for organic solvent-based gravure printing tend to have reduced stability over time. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] International Publication No. 2007 / 088733 [Patent Document 2] Japanese Patent Publication No. 2013-231122 [Patent Document 3] International Publication No. 2017 / 098660 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] In gravure printing methods that create shallower plates, it is necessary to increase the pigment concentration in the ink composition. However, if an amount of binder resin is added to match this without reducing the film-coating strength of the ink composition, the ink viscosity increases, leading to the problem of printed materials being prone to smudging. On the other hand, reducing the amount of binder resin to lower viscosity led to problems such as decreased cohesiveness of the ink film, resulting in reduced abrasion resistance and poor lamination suitability when laminating. Therefore, low molecular weight polyurethane polyurea resin is used as the binder resin. However, this low molecular weight polyurethane polyurea resin generates a large amount of free amines, and high-solid ink compositions for organic solvent-based gravure printing using it had problems such as odor generation and reduced stability over time. Therefore, the problem that the present invention aims to solve is to provide an organic solvent-based high-solid ink composition for gravure printing that has low odor, good stability over time, and good print density, printability, and lamination suitability even when gravure printing is performed using a shallow printing plate, and a gravure printing method using the organic solvent-based high-solid ink composition for gravure printing. [Means for solving the problem]

[0008] The inventors have found that the above problems can be solved by employing an organic solvent-based high-solid ink composition for gravure printing containing a specific polyurethane polyurea resin. In other words, the present invention is as follows: 1. A high-solids ink composition for gravure printing containing a pigment, a binder resin, and an organic solvent, The aforementioned pigment is an organic pigment and / or an inorganic pigment. The binder resin contains the following polyurethane polyurea resins (A) and / or (B): The pigment and the binder resin are characterized in that they satisfy the following conditions 1 to 3, making this an organic solvent-based high-solid ink composition for gravure printing. (A) One or more polyurethane polyurea resins with a weight-average molecular weight of 20,000 to 50,000, selected from (A-1) and (A-2) below. (A-1) A polyurethane polyurea resin obtained by reacting a urethane prepolymer obtained by reacting a diol compound with a diisocyanate compound and a compound in which the amino group of a polyamine compound has been ketiminated by a ketone compound, and then performing chain elongation and reaction termination in an organic solvent. (A-2) A polyurethane polyurea resin is obtained by reacting a urethane prepolymer, which is obtained by reacting a diol compound and a diisocyanate compound, with a reaction termination agent in an organic solvent, and then chain elongation and reaction termination with a compound in which the amino group of a polyamine compound has been ketiminated by a ketone compound. (B) One or more polyurethane polyurea resins with a weight-average molecular weight of 20,000 to 50,000, selected from (B-1) and (B-2) below. (B-1) A polyurethane polyurea resin is obtained by reacting a diol compound with a diisocyanate compound to obtain a urethane prepolymer, and then adding a compound in which the amino group of a polyamine compound has been ketiminated by a ketone compound to a urethane prepolymer solution with an organic solvent, stirring and mixing, and then adding water, followed by chain elongation and reaction termination. (B-2) A polyurethane polyurea resin is obtained by reacting a diol compound with a diisocyanate compound to obtain a urethane prepolymer, then adding a reaction stopper to a urethane prepolymer solution with an organic solvent and allowing the reaction to proceed. Next, a compound in which the amino group of a polyamine compound has been ketiminated by a ketone compound is added and stirred and mixed. After adding water, chain elongation and reaction cessation are performed to obtain the polyurethane polyurea resin. (Condition 1) When the pigment is an organic pigment, the content of the organic pigment in the organic solvent-based gravure printing high-solid ink composition is 5 to 20% by mass. (Condition 2) When the pigment is an inorganic pigment, the content of the inorganic pigment in the organic solvent-based gravure printing high-solid ink composition is 30 to 70% by mass. (Condition 3) When the pigment includes both organic and inorganic pigments, the content of the organic pigment in the organic solvent-based gravure printing high-solid ink composition is 5 to 20% by mass, and the mass ratio of the inorganic pigment to the organic pigment {inorganic pigment (mass) / organic pigment (mass)} is 0 < inorganic pigment (mass) / organic pigment (mass) < 7.0. 2. The organic solvent-based high-solid ink composition for gravure printing according to claim 1, wherein the polyurethane polyurea resin is one or more selected from polyurethane polyurea resins having a primary amino group at the terminal, polyurethane polyurea resins having a primary amino group and a secondary amino group at the terminal, and polyurethane polyurea resins having a group in which the primary amino group is ketiminated at the terminal. 3. An organic solvent-based high-solid ink composition for gravure printing according to claim 1 or 2, comprising a vinyl chloride / vinyl acetate copolymer and / or a vinyl chloride / acrylic copolymer as a binder resin. 4. An organic solvent-based high-solid ink composition for gravure printing according to any one of 1 to 3, comprising at least one selected from rosin and its derivatives, chlorinated polypropylene, dammar resin as an adhesion improver, and silica particles, polyethylene wax, fatty acid amide, cellulose acetate propionate resin, cellulose acetate butyrate resin, and nitrated cotton as an antiblocking agent. 5. The organic solvent is a mixed solvent of an ester-based organic solvent and an alcohol-based organic solvent, which is the organic solvent-based high-solid ink composition for gravure printing according to any one of 1 to 4. 6. The high-solids ink composition for gravure printing is obtained by further diluting it with an organic solvent during gravure printing, and the organic solvent is a mixed solvent of an ester-based organic solvent and an alcohol-based organic solvent. The organic solvent-based high-solid ink composition for gravure printing, wherein the usage ratio of the ester-based solvent and the alcohol-based organic solvent in the composition is ester-based organic solvent / alcohol-based organic solvent = 50 / 50 to 95 / 5, as described in 5. 7. The organic solvent-based high-solid ink composition for gravure printing according to 5 or 6, which contains 5% by mass or more of propyl acetate as an ester-based solvent in the organic solvent-based high-solid ink composition for gravure printing. 8. A gravure printing method using the organic solvent-based high-solid ink composition according to any one of 1 to 7, wherein an organic solvent-based high-solid ink composition for gravure printing is prepared by adding and diluting an organic solvent to the organic solvent-based high-solid ink composition for gravure printing, and printing is performed by a gravure printing method using an etched gravure plate with the organic solvent-based high-solid ink composition for gravure printing.

Advantages of the Invention

[0009] According to the present invention, the organic solvent-based high-solid ink composition for gravure printing has good stability over time, and even when gravure printing is performed using an etched printing plate, the printed matter has little odor and exhibits good printing density, printing suitability, and laminating suitability.

Embodiments for Carrying Out the Invention

[0010] Hereinafter, the organic solvent-based high-solid ink composition for gravure printing of the present invention will be described.

[0011] <Pigment> As the above pigment, various inorganic pigments, organic pigments, etc. generally used in printing inks can be used. Examples of the inorganic pigment include colored pigments such as titanium oxide, red iron oxide, antimony red, cadmium yellow, cobalt blue, ultramarine blue, ultramarine, carbon black, and graphite; extender pigments such as silica, calcium carbonate, kaolin, clay, barium sulfate, aluminum hydroxide, and talc; aluminum paste containing aluminum particles surface-treated with an acrylic resin; and pearl pigments such as mica coated with titanium oxide, tin oxide, and zirconium oxide on the surface. Examples of the organic pigment include soluble azo pigments, insoluble azo pigments, azo lake pigments, condensed azo pigments, copper phthalocyanine pigments, and condensed polycyclic pigments.

[0012] In the high-solid ink composition for solvent-based gravure printing of the present invention, when the pigment is an organic pigment, the content thereof is 5 to 20% by mass, preferably 6 to 15% by mass; when the pigment is an inorganic pigment, the content thereof is 30 to 70% by mass, preferably 35 to 60% by mass. When both an organic pigment and an inorganic pigment are used in combination, the content of the organic pigment in the high-solid ink composition for solvent-based gravure printing is 5 to 20% by mass, and the mass ratio of the inorganic pigment to the organic pigment {inorganic pigment (mass) / organic pigment (mass)} is preferably such that 0 < inorganic pigment (mass) / organic pigment (mass) < 7.0. And an organic pigment and an inorganic pigment can also be used in combination. When the content of each of the organic pigment and the inorganic pigment in the high-solid ink composition for solvent-based gravure printing of the present invention is less than the above range, the coloring power when the ink composition is formed decreases, and it tends to be difficult to cope with the shallowing of the gravure printing plate. On the other hand, when it exceeds the above range, there is a problem that the viscosity becomes high and the printed matter is likely to be soiled during solvent-based gravure printing.

[0013] <Binder resin> The binder resin in the present invention contains the polyurethane polyurea resin of the following (A) and / or (B). (A) One or more polyurethane polyurea resins with a weight-average molecular weight of 20,000 to 50,000, selected from (A-1) and (A-2) below. (A-1) A polyurethane polyurea resin obtained by reacting a urethane prepolymer obtained by reacting a diol compound with a diisocyanate compound and a compound in which the amino group of a polyamine compound has been ketiminated by a ketone compound, and then performing chain elongation and reaction termination in an organic solvent. (A-2) A polyurethane polyurea resin is obtained by reacting a urethane prepolymer, which is obtained by reacting a diol compound and a diisocyanate compound, with a reaction termination agent in an organic solvent, and then chain elongation and reaction termination with a compound in which the amino group of a polyamine compound has been ketiminated by a ketone compound. (B) One or more polyurethane polyurea resins with a weight-average molecular weight of 20,000 to 50,000, selected from (B-1) and (B-2) below. (B-1) A polyurethane polyurea resin is obtained by reacting a diol compound with a diisocyanate compound to obtain a urethane prepolymer, and then adding a compound in which the amino group of a polyamine compound has been ketiminated by a ketone compound to a urethane prepolymer solution with an organic solvent, stirring and mixing, and then adding water, followed by chain elongation and reaction termination. (B-2) A polyurethane polyurea resin is obtained by reacting a diol compound with a diisocyanate compound to obtain a urethane prepolymer, then adding a reaction stopper to a urethane prepolymer solution with an organic solvent and allowing the reaction to proceed. Next, a compound in which the amino group of a polyamine compound has been ketiminated by a ketone compound is added and stirred and mixed. After adding water, chain elongation and reaction cessation are performed to obtain the polyurethane polyurea resin. Furthermore, it is preferable that the polyurethane polyurea resin is one or more selected from polyurethane polyurea resins having a primary amino group at the terminal, polyurethane polyurea resins having a primary amino group and a secondary amino group at the terminal, and polyurethane polyurea resins having a group at the terminal in which the primary amino group is ketiminated.

[0014] ((A) Polyurethane polyurea resin) The polyurethane polyurea resin in (A) is one or more polyurethane polyurea resins selected from (A-1) and (A-2), which are described below. (A-1) is a polyurethane polyurea resin obtained by reacting a diol compound with a diisocyanate compound to form a urethane prepolymer, in which the amino group of a polyamine compound is ketiminated with a ketone compound, and then performing chain extension and reaction termination in an organic solvent. (A-2) is a polyurethane polyurea resin obtained by reacting a urethane prepolymer, which is obtained by reacting a diol compound and a diisocyanate compound, with a reaction termination agent in an organic solvent, and then extending the chain and terminating the reaction with a compound in which the amino group of the polyamine compound has been ketiminated by a ketone compound. One or more polyurethane polyurea resins selected from (A-1) and (A-2) all have a weight-average molecular weight of 20,000 to 50,000. Preferably, all have a molecular weight of 25,000 or more, and preferably 45,000 or less. If the weight-average molecular weight is less than 20,000, storage stability tends to decrease. Furthermore, the weight-average molecular weight of the present invention can be measured by gel permeation chromatography (GPC). For example, using a Water2690 GPC instrument (Waters Corporation) and a PLgel, 5μ, MIXED-D column (Polymer Laboratories), chromatography can be performed under the following conditions: tetrahydrofuran as the developing solvent, column temperature 25°C, flow rate 1 ml / min, RI detector, sample injection concentration 10 mg / ml, and injection volume 100 microliters. The weight-average molecular weight can then be determined as polystyrene equivalent. Furthermore, both (A-1) and (A-2) are preferably polyurethane polyurea resins having a group with a primary amino group ketiminated at its terminus. Compared to binder resins used in general ink compositions, polyurethane resins having a primary amino group ketiminated at its terminus have a very high pigment dispersion effect and do not reduce the film cohesiveness of the ink composition even when the pigment concentration in the ink composition is high. Therefore, an organic solvent-based high-solid ink composition for gravure printing containing a polyurethane resin having a primary amino group ketiminated at its terminus exhibits good print density, printability, and lamination suitability even when gravure printing is performed using a shallow printing plate.

[0015] • Diol compounds The diol compounds used in (A-1) and (A-2) above can be high-molecular-weight diol compounds or biopolyester diol compounds. Examples of polymeric diol compounds include polyester diols and polycaprolactone diols obtained by condensing one or more dibasic acids such as adipic acid, sebacic acid, and phthalic anhydride with one or more glycols such as ethylene glycol, propylene glycol, 1,4-butanediol, neopentyl glycol, and 3-methyl-1,5-pentanediol; polyether diol compounds such as polyalkylene glycols such as polyethylene glycol and polypropylene glycol; and alkylene oxide adducts such as ethylene oxide and propylene oxide of bisphenol A. These polymeric diol compounds can be used individually or in combination of two or more. Among these, 3-methyl-1,5-pentylene adipate diol with a number average molecular weight of 1,000 to 8,000 obtained by the condensation reaction of adipic acid and 3-methyl-1,5-pentanediol is preferred, and 3-methyl-1,5-pentylene adipate diol with a number average molecular weight of 1,000 to 4,000 is even more preferred.

[0016] • Biopolyester diol compounds When considering environmental factors, biopolyester polyols should be used as the polyester polyol compound. The biopolyester diol compound is preferably a biopolyester polyol compound obtained by reacting a short-chain diol component having 2 to 4 carbon atoms with a carboxylic acid component. At least one of the short-chain diol component and the carboxylic acid component is plant-derived. It is even more preferable that both are plant-derived.

[0017] The plant-derived short-chain diol components with 2 to 4 carbon atoms are not particularly limited. For example, the short-chain diol components may be 1,3-propanediol, 1,4-butanediol, ethylene glycol, etc., obtained from plant raw materials by the following method. These may be used in combination.

[0018] 1,3-Propanediol can be produced from glycerol via 3-hydroxypropyl aldehyde (HPA) by fermentation, which involves decomposing plant resources (such as corn) to obtain glucose. Compared to 1,3-propanediol compounds produced by bio-methods such as the above fermentation method, 1,3-propanediol compounds produced by EO-based methods offer advantages in terms of safety, yield useful by-products such as lactic acid, and can also be manufactured at lower costs. 1,4-Butanediol can be produced by obtaining succinic acid through fermentation of glycol produced from plant resources, and then hydrogenating it. Ethylene glycol can also be produced from bioethanol obtained by conventional methods via ethylene.

[0019] The plant-derived carboxylic acid components are not particularly limited. Examples include sebacic acid, succinic acid, lactic acid, glutaric acid, and dimer acid. These may be used in combination. Among these, the carboxylic acid component preferably contains at least one selected from the group consisting of sebacic acid, succinic acid, and dimer acid. Furthermore, it may contain 0.05 to 0.5 parts by mass of malic acid per 100 parts by mass of sebacic acid.

[0020] From an environmental perspective, biomass urethane prepolymers obtained from these plant-derived components are preferably present in the total urethane prepolymer at a concentration of 10% by mass or more, and more preferably at a concentration of 40% by mass or more, in terms of solid content.

[0021] Furthermore, in addition to the above polymer diol compounds, alkanediols such as 1,4-pentanediol, 2,5-hexanediol, and 3-methyl-1,5-pentanediol, as well as low molecular weight diol compounds such as ethylene glycol, propylene glycol, 1,4-butanediol, and 1,3-butanediol, can be used individually or in combination of two or more.

[0022] • Diisocyanate compounds Organic diisocyanates can be used as the diisocyanate compounds in (A-1) and (A-2) above. Examples of organic diisocyanate compounds include aromatic diisocyanate compounds such as 1,3- and / or 1,4-phenylenediisocyanate, 4,4-diisocyanatobiphenyl, 3,3-dimethyl-4,4-diisocyanatobiphenyl, and tolylene diisocyanate, as well as dicyclohexylmethane 4,4'-diisocyanate, 1,4-cyclohexane diisocyanate, cyclohexylene diisocyanate, dicyclohexylmethane-4,4-diisocyanate (hydrogenated MDI), methylcyclohexylene diisocyanate (hydrogenated TDI), and isophorone diisocyanate. Examples include alicyclic diisocyanate compounds such as nate, aliphatic diisocyanate compounds such as hexamethylene diisocyanate (HDI), ethylene diisocyanate, tetramethylene 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 individually or in combination of two or more. Among these, alicyclic diisocyanates, aliphatic diisocyanates, and aromatic aliphatic diisocyanates are more preferred.

[0023] <Organic solvents> There are no particular restrictions on the organic solvent used to obtain the polyurethane polyurea resins (A-1) and (A-2) in the present invention, but from an environmental standpoint, it is preferable that the solvent does not contain aromatic hydrocarbon organic solvents. Examples of such solvents include alcohol-based organic solvents such as methanol, ethanol, n-propanol, isopropanol, 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 organic solvents such as n-hexane, n-heptane, and n-octane; and alicyclic hydrocarbon organic solvents such as cyclohexane, methylcyclohexane, ethylcyclohexane, cycloheptane, and cyclooctane. At least one of the solvents may be used, and two or more may be used in combination, taking into consideration the solubility and drying properties of the binder resin. However, from the viewpoint of greater consideration for the environment, it is preferable to suppress the use of ketone-based organic solvents among the aforementioned solvents. A more preferable solvent is a mixed solvent of an ester-based solvent and an alcohol-based solvent, and a solvent obtained by mixing ethyl acetate and propyl acetate in a mass-based ratio of ethyl acetate:propyl acetate = 1 to 4:1, and then further mixing isopropyl alcohol with the mixed ester-based solvent. Among these, a solvent obtained by mixing the mixed ester-based solvent and isopropyl alcohol in a ratio of 1 to 5:1 is even more preferable.

[0024] • Compounds in which the amino group of a polyamine compound has been ketiminated by a ketone compound. (Polyamine compounds) When obtaining the polyurethane polyurea resins (A-1) and (A-2) in the present invention, known polyamine compounds used in polyurethane polyurea resins as binders for ink compositions can be used as polyamine compounds. For example, 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; hydroxyl-containing diamines 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 can be used. Furthermore, polyamine compounds such as diethylenetriamine and triethylenetetramine can be used in combination, provided that the polyurethane polyurea resin does not gel.

[0025] (A compound in which the amino group of a polyamine compound has been ketiminated by a ketone compound.) Polyamine compounds that have been pre-ketiminated with an excess amount of ketone compound can be used. In particular, isophorone diamine and / or N-(2-hydroxyethyl)ethylenediamine are preferred as the polyamine compound. Polyamine compounds ketiminated with ketone compounds have a structure in which the oxygen atom of the ketone compound is replaced by the nitrogen atom of the amino group of the polyamine compound. Preferred ketone compounds include acetone, diethyl ketone, methyl ethyl ketone, and diacetone alcohol. Compounds in which the amino group of a polyamine compound is ketiminated by a ketone compound act as chain elongation and reaction termination agents. In this ketimination reaction, it is preferable not to use solvents other than ketone compounds. However, other organic solvents may be added, as long as they do not interfere with the subsequent chain elongation reaction or the effect of the polyurethane polyurea resin being odorless.

[0026] • Reaction inhibitor In obtaining the polyurethane polyurea resin of (A-2) in the present invention, known reaction stoppers such as alkanolamines such as monoethanolamine and diethanolamine, monoamine compounds such as n-propylamine and n-butylamine, dialkylamines such as di-n-butylamine, and monoalcohol compounds such as ethanol can be used. Furthermore, in (A-1), the above reaction stoppers that can be used in (A-2) can also be used as described below.

[0027] (Methods for producing polyurethane polyurea resin of (A-1) and polyurethane polyurea resin of (A-2)) The polyurethane polyurea resin of (A-1) can be obtained by first dissolving a urethane prepolymer, obtained by reacting a diol compound and a diisocyanate compound, in an organic solvent to form a urethane prepolymer solution, and then adding a compound in which the amino group of a polyamine compound has been ketiminated by a ketone compound, followed by chain elongation and reaction termination to obtain the polyurethane polyurea resin. Alternatively, after forming the urethane prepolymer solution, a compound in which the amino group of a polyamine compound has been ketiminated by a ketone compound and a reaction termination agent can be added, followed by chain elongation and reaction termination to obtain the polyurethane polyurea resin. The polyurethane polyurea resin of (A-2) can be obtained by first dissolving a urethane prepolymer obtained by reacting a diol compound and a diisocyanate compound in an organic solvent to make a urethane prepolymer solution, then adding a reaction stopper and reacting it with the urethane polymer, and then adding a compound in which the amino group of the polyamine compound has been ketiminated by a ketone compound to extend the chain and stop the reaction.

[0028] When reacting the diisocyanate compound and the diol compound, the respective usage ratio is such that the equivalent ratio of isocyanate group to hydroxyl group (isocyanate index) is typically in the range of 1.2 to 3.0, more preferably 1.3:1 to 2.0. If the above isocyanate index is less than 1.2, the resulting material tends to be a flexible polyurethane polyurea resin, which may have low blocking resistance when printing ink compositions. In this case, it may be necessary to use it in combination with other rigid resins.

[0029] A catalyst can be used during the reaction between the diisocyanate compound and the diol compound. Among these, organometallic compounds are preferred, and such organometallic compounds include titanium compounds such as dibutyltitanium dichloride, tetrabutyltitanate, and butoxytitanium trichloride, as well as dibutyltin sulfide, tributyltin sulfide, tributyltin oxide, dibutyltin dichloride, dibutyltin oxide, dibutyltin dibromide, dibutyltin dimaleate, dibutyltin dilaurate, dibutyltin diacetate, dioctyltin dilaurate, and tributyltin dilaurate. Examples of tin compounds include 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 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. Tertiary amine compounds can also be used, for example, triethylamine, triethylenediamine, 1,4-diazabicyclo(2,2,2)octane, and 1,8-diazabicyclo(5,4,0)-undecene-7 (DBU).

[0030] ((B) Polyurethane polyurea resin) The polyurethane polyurea resin in (B) is one or more polyurethane polyurea resins selected from (B-1) and (B-2), which are described below. (B-1) is a polyurethane polyurea resin obtained by reacting a diol compound with a diisocyanate compound to obtain a urethane prepolymer solution with an organic solvent, adding a compound in which the amino group of a polyamine compound has been ketiminated by a ketone compound, stirring and mixing, then adding water, and finally performing chain extension and reaction termination. (B-2) is a polyurethane polyurea resin obtained by reacting a diol compound with a diisocyanate compound to form a urethane prepolymer solution with an organic solvent, adding a reaction stopper, then adding a compound in which the amino group of a polyamine compound has been ketiminated by a ketone compound, stirring and mixing, and finally adding water, followed by chain elongation and reaction cessation. One or more polyurethane polyurea resins selected from (B-1) and (B-2) all have a weight-average molecular weight of 20,000 to 50,000. Preferably, all have a molecular weight of 25,000 or more, and preferably 45,000 or less. Furthermore, both (B-1) and (B-2) are preferably polyurethane polyurea resins having a group with a primary amino group ketiminated at its terminus. Compared to binder resins used in general ink compositions, polyurethane resins having a primary amino group ketiminated at its terminus have a very high pigment dispersion effect and do not reduce the film cohesiveness of the ink composition even when the pigment concentration in the ink composition is high. Therefore, an organic solvent-based high-solid ink composition for gravure printing containing the polyurethane polyurea resin having a primary amino group ketiminated at its terminus will have good print density, printability, and lamination suitability even when gravure printing is performed using a shallow printing plate. The amine value of the polyurethane polyurea resin is preferably 1 to 10 mg KOH / g. If the above amine value is less than 1 mg KOH / g, for example, the adhesion to the film when laminated may decrease, and furthermore, the lamination suitability may decrease. If the above amine value exceeds 10 mg KOH / g, the blocking resistance may decrease. In this invention, the above amine value refers to the amine value per gram of solid content, and is the value obtained by measuring it using a 0.1N aqueous hydrochloric acid solution by potentiometric titration (for example, COMTITE (AUTO TITRATOR COM-900, BURET B-900, TITSTATION K-900), manufactured by Hiranuma Sangyo Co., Ltd.) and then converting it to the equivalent amount of potassium hydroxide.

[0031] The diol compound, diisocyanate compound, organic solvent, reaction stopper, compound in which the amino group of a polyamine compound has been ketiminated by a ketone compound, and catalyst used in the reaction between the diisocyanate compound and the diol compound can be the same as those described for the polyurethane polyurea resin in (A).

[0032] (water) The amount of water used should preferably be within a range that does not cause precipitation of the polyurethane polyurea resin obtained by the method for producing the polyurethane polyurea resin solution. Specifically, the amount of water used should preferably be 0.2 to 5.0% by mass, and more preferably 0.4 to 1.5% by mass, relative to the solid content of the polyurethane polyurea resin solution.

[0033] (Methods for producing polyurethane polyurea resin of (B-1) and polyurethane polyurea resin of (B-2)) The polyurethane polyurea resin of (B-1) can be obtained by first dissolving a urethane prepolymer obtained by reacting a diol compound and a diisocyanate compound in an organic solvent to make a urethane prepolymer solution, then adding a compound in which the amino group of a polyamine compound has been ketiminated by a ketone compound to the urethane prepolymer solution and stirring and mixing, then adding water, and finally performing chain extension and reaction termination to obtain the polyurethane polyurea resin. Alternatively, after making a urethane prepolymer solution, a compound in which the amino group of a polyamine compound has been ketiminated by a ketone compound and a reaction termination agent can be added and stirred and mixed, and then chain extension and / or reaction termination can be performed to obtain the polyurethane polyurea resin. The polyurethane polyurea resin of (B-2) is obtained by first dissolving a urethane prepolymer obtained by reacting a diol compound and a diisocyanate compound in an organic solvent to make a urethane prepolymer solution, then adding a reaction stopper to the urethane prepolymer solution and reacting it with the urethane polymer, then adding a compound in which the amino group of the polyamine compound has been ketiminated by a ketone compound and stirring and mixing, and finally adding water, followed by chain elongation and reaction cessation to obtain the polyurethane polyurea resin.

[0034] When reacting the diisocyanate compound and the diol compound, the respective usage ratio is such that the equivalent ratio of isocyanate group to hydroxyl group (isocyanate index) is typically in the range of 1.2:1 to 3.0:1, more preferably 1.3:1 to 2.0:1. If the above isocyanate index is less than 1.2, the resulting material tends to be a flexible polyurethane polyurea resin, which may have low blocking resistance when printing the ink composition. In this case, it may be necessary to use it in combination with other rigid resins.

[0035] <Organic solvents> The organic solvent described above for the binder resin can be used in the organic solvent-based high-solid ink composition for gravure printing of the present invention. Furthermore, to improve wetting properties, the organic solvent can be enriched by including 0.1 to 20% by mass of glycol ether-based organic solvent in 100% by mass of the organic solvent. Specific examples of glycol ether-based 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 mono-n-propyl ether, diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, and diethylene glycol diethyl ether.

[0036] <Other Compounds> The organic solvent-based high-solid ink composition for gravure printing of the present invention may contain, as a binder resin, vinyl chloride / vinyl acetate copolymer, vinyl chloride / acrylic copolymer, etc.; as an adhesion improver, rosin and its derivatives, chlorinated polypropylene, dammar resin, etc.; as an antiblocking agent, silica particles, polyethylene wax, fatty acid amide, cellulose acetate propionate resin, cellulose acetate butyrate resin, nitrated cotton, etc.; pigment dispersants and dispersing aids, organic solvents, water, antistatic agents, and silane coupling agents.

[0037] (Vinyl chloride / vinyl acetate copolymer as a binder resin) As a binder resin, in addition to polyurethane polyurea resin, a vinyl chloride / vinyl acetate copolymer can be used in combination depending on the pigment being blended to improve adhesion. As a vinyl chloride / vinyl acetate copolymer, vinyl chloride monomer and vinyl acetate monomer, which have been conventionally used in gravure ink compositions, are essential components, and if necessary, fatty acid vinyl monomers such as vinyl propionate, vinyl monochloroacetate, vinyl versatate, vinyl lauryl acid, vinyl stearate, vinyl benzoate, and monomers having functional groups such as hydroxyl groups, can be used, produced by conventionally known methods. In particular, vinyl chloride / vinyl acetate copolymers are preferred for use in organic solvent systems of environmentally friendly ink compositions, especially those having hydroxyl groups, preferably with a hydroxyl value of 50 to 200 mg KOH / g. Such vinyl chloride / vinyl acetate copolymers having hydroxyl groups can be obtained by saponifying a portion of the acetate ester portion or by introducing a (meth)acrylic monomer having hydroxyl groups. In the case of vinyl chloride / vinyl acetate copolymers having hydroxyl groups obtained by saponifying a portion of the acetate ester portion, the film properties and dissolution behavior of the resin are determined by the ratio of constituent units based on the reaction sites of vinyl chloride in the molecule (Formula 1 below), constituent units based on the reaction sites of vinyl acetate (Formula 2 below), and constituent units based on the saponification of the reaction sites of vinyl acetate (Formula 3 below). Specifically, constituent units based on the reaction sites of vinyl chloride impart toughness and hardness to the resin film, constituent units based on the reaction sites of vinyl acetate impart adhesion and flexibility, and constituent units based on the saponification of the reaction sites of vinyl acetate impart good solubility of the environmentally friendly ink composition in organic solvent systems. Formula 1 -CH2-CHCl- Formula 2 -CH2-CH(OCOCH3)- Formula 3 -CH2-CH(OH)- Such vinyl chloride / vinyl acetate copolymers may be commercially available, for example, Solvine A, AL, TA5R, TA2, TA3, TAO, TAOL, C, CH, CN, CNL, etc., manufactured by Nisshin Chemical Industry Co., Ltd. Furthermore, the vinyl chloride / vinyl acetate copolymer used in the ink composition containing the polyurethane polyurea resin obtained by the present invention preferably has various functional groups in its molecule, from the viewpoint of solubility in the organic solvents described below and printability. Furthermore, 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 vinyl chloride / vinyl acetate copolymers, it is preferable to use, for example, Solvine A, AL, TA5R, TA2, TA3, TAO, TAOL, etc., manufactured by Nisshin Chemical Industry Co., Ltd.

[0038] (Vinyl chloride / acrylic copolymer as a binder resin) As a binder resin, in addition to polyurethane polyurea resin, a vinyl chloride / acrylic copolymer can be used in combination depending on the pigment being blended to improve adhesion. Vinyl chloride / vinyl acetate copolymers primarily consist of a copolymer of vinyl chloride and acrylic monomer. The form of the copolymer is not particularly limited; for example, the acrylic monomer may be incorporated into the main chain of polyvinyl chloride in a block or random manner, or it may be graft copolymerized into the side chains of polyvinyl chloride. As the acrylic monomer, (meth)acrylic acid esters, acrylic monomers having a hydroxyl group, etc., can be used. Examples of (meth)acrylic acid esters include alkyl (meth)acrylic acid esters, where the alkyl group may be linear, branched, or cyclic, but a linear alkyl group is preferred. Examples include 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. Examples of acrylic monomers having a hydroxyl group include hydroxyalkyl esters of (meth)acrylates 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, as well as 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. Furthermore, acrylic monomers having functional groups other than hydroxyl groups can also be used as acrylic monomers. Examples of functional groups other than hydroxyl groups include carboxyl groups, amide groups, amino groups, alkylene oxide groups, and the like. The vinyl chloride / acrylic copolymer resin described above preferably has a weight-average molecular weight of 10,000 to 70,000. Furthermore, in terms of solubility in environmentally friendly solvents and adhesion to the substrate, the vinyl chloride / acrylic copolymer preferably has 50 to 200 hydroxyl groups.

[0039] When a vinyl chloride / vinyl acetate copolymer or vinyl chloride / acrylic copolymer is included as a binder resin, the polyurethane polyurea resin and (vinyl chloride / vinyl acetate copolymer and / or vinyl chloride / acrylic copolymer) can be included 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 including the polyurethane polyurea resin and the vinyl chloride / vinyl acetate copolymer and / or vinyl chloride / acrylic copolymer in such proportions, the organic solvent-based gravure printing high-solid ink composition obtained by the present invention will have even better printability and adhesion to film. Furthermore, when lamination is performed, it will have even better lamination suitability. If the ratio of the polyurethane polyurea resin / (vinyl chloride / vinyl acetate copolymer and / or vinyl chloride / acrylic copolymer) is less than 45 / 55, the proportion of (vinyl chloride / vinyl acetate copolymer and / or vinyl chloride / acrylic copolymer) increases, which may result in a hardened printed material formed using the organic solvent-based gravure printing high-solid ink composition obtained according to the present invention, and thus insufficient adhesion to the film.

[0040] (Rosin and its derivatives as adhesion enhancers) Examples of rosin include gum rosin, tall oil rosin, and wood rosin. Generally, rosin is an amber-colored, amorphous resin obtained from pine trees. Although it is a mixture because it is obtained from natural sources, it may also be used by isolating each of its constituent components, such as abietic acid, neoabietic acid, palastic acid, pimaric acid, isopimaric acid, sandaracopimaric acid, and dehydroabietic acid. In this invention, these are also defined as rosin. Rosin derivatives are compounds obtained by modifying the above-mentioned rosin, and are specifically listed below. (1) Hydrogenated rosin: This is a type of rosin in which hydrogen is added to the conjugated double bond (hydrogenation) to improve weather resistance. (2) Disproportionated rosin: Disproportionation is the reaction of two molecules of rosin to form a conjugated double bond. This modification involves altering the abietic acid molecule, with one molecule forming an aromatic compound and the other a molecule with a single double bond. Generally, it has inferior weather resistance compared to hydrogenated rosin, but it is improved compared to untreated material. (3) Rosin-modified phenolic resin: Rosin-modified phenolic resin is often used as the main binder in offset printing ink compositions. Rosin-modified phenolic resin can be obtained by known manufacturing methods. (4) Rosin esters: These are ester resins derived from rosin and have long been used as tackifiers for adhesives and glues. (5) Rosin-modified maleic acid resin: This is produced by adding maleic anhydride to rosin, and may also include resins in which a hydroxyl group-containing compound such as glycerin is esterified with the anhydride group and grafted onto it, if necessary. (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 rosin and rosin derivatives is preferably 120 mgKOH / g or higher. An acid value of 120 mgKOH / g or higher improves the laminate strength. More preferably, the acid value is 160 mgKOH / g or higher. In addition, the total amount of rosin and rosin derivatives used is 3.0% by mass or less, preferably 0.1% to 3.0% by mass, in terms of the solid content mass% of the organic solvent-based gravure printing high-solid ink composition of the present invention.

[0041] (Chlorinated polypropylene as an adhesion enhancer) As chlorinated polypropylene, those with a degree of chlorination of 20 to 50 can be used. Chlorinated polypropylene with a degree of chlorination of less than 20 tends to have reduced compatibility with organic solvents. On the other hand, when the degree of chlorination exceeds 50, chlorinated polypropylene tends to have reduced adhesion to films. The degree of chlorination is defined as the mass percentage of chlorine atoms in the chlorinated polypropylene resin. Furthermore, it is preferable that the chlorinated polypropylene is modified or unmodified chlorinated polypropylene with a weight-average molecular weight of 5,000 to 200,000. When the weight-average molecular weight is less than 5,000, chlorinated polypropylene tends to have reduced adhesion. On the other hand, when the weight-average molecular weight exceeds 200,000, chlorinated polypropylene tends to have reduced solubility in organic solvents. Furthermore, the amount of chlorinated polypropylene used is 3.0% by mass or less, preferably 0.1% to 3.0% by mass, in terms of the solid content mass% of the organic solvent-based gravure printing high-solid ink composition of the present invention.

[0042] (Dammar resin as an adhesion improver) Dammar resin, also spelled Damar or Dammar, is a type of natural resin derived from plants. Specifically, it is a type of natural resin obtained from Dipterocarpaceae or Burseraceae plants that grow in Southeast Asia, such as Malaysia and Indonesia. When used, it is dissolved in a suitable organic solvent to form a varnish. Since dammar resin does not contain chlorine, it is possible to eliminate or reduce chlorine compared to using chlorinated polyolefin resin in the ink composition. Furthermore, the amount of dammar resin used is 3.0% by mass or less, preferably 0.1% to 3.0% by mass, in terms of the solid content mass% of the organic solvent-based gravure printing high-solids ink composition of the present invention.

[0043] (Silica particles as an anti-blocking agent) Examples of silica include naturally occurring silica, synthetic silica, crystalline silica, crystalline silica, and silica, as well as silica, silica, and silica. The silica particles are preferably in the range of an average particle diameter of 1 to 5 μm (the average particle diameter of silica particles refers to the particle size at 50% of the cumulative particle size distribution (D50), which can be determined by the Coulter counter method). The silica particles may be hydrophilic silica having hydrophilic functional groups on their surface, or hydrophobic silica whose hydrophilic functional groups have been modified with alkylsilane or the like to make them hydrophobic, but hydrophilic silica is preferred. An ink composition containing hydrophilic silica particles promotes wetting and spreading of the ink composition during overprinting, and also has the effect of improving the overprinting effect (hereinafter sometimes referred to as "trapping properties"). The amount of silica particles used 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, in the organic solvent-based gravure printing high-solid ink composition of the present invention. If the content is higher than 3.0% by mass, gloss tends to decrease.

[0044] (Polyethylene wax as an anti-blocking agent) The polyethylene wax used has an average particle size in the range of 1.0 to 20 μm (Note: The average particle size refers to the particle size measured with #1: Honeywell Microtrac UPA). If the polyethylene wax particle size is smaller than 1.0 μm, the slipperiness and blocking properties during lamination will decrease, and if the particle size is larger than 20 μm, the trapping properties will decrease. Furthermore, the polyethylene wax content in the organic solvent-based gravure printing high-solid ink composition of the present invention is preferably in the range of 0.1 to 1.5% by mass. If the content is less than 0.1% by mass, the desired effect will not be obtained, and if the content is more than 1.5% by mass, gloss tends to decrease.

[0045] (Fatty acid amides as blocking inhibitors) The fatty acid amide is not particularly limited as long as it has a fatty acid residue and an amide group. Examples of fatty acid amides include monoamides, substituted amides, bisamides, methylolamides, and esteramides. It is preferable that at least one selected from the group consisting of monoamides, substituted amides, and bisamides is used to improve blocking resistance. The amount of fatty acid amide used in the organic solvent-based gravure printing high-solid ink composition of the present invention is 1% by mass or less, preferably in the range of 0.01 to 1% by mass. Monoamides: Monoamides are represented by the following general formula (1). General formula (1) R1-CONH2 (In the formula, R1 represents the residue obtained by removing the COOH group 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. Substitutive amides: Substitutive amides are represented by the following general formula (2). General formula (2) R2-CONH-R3 (In the formula, R2 and R3 represent the residues obtained by removing the COOH group from the fatty acid, and may be the same or different.) Specific examples of substituted amides include N-oleyl palmitate amide, N-stearyl stearate amide, N-stearyl oleate amide, N-oleyl stearate amide, and N-stearyl erucate 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 residues obtained by removing the COOH group from a fatty acid, and may be the same or different. R5 and R8 represent alkylene or arylene groups having 1 to 10 carbon atoms.) Specific examples of bisamides include methylenebisstearate, ethylenebiscaprate, ethylenebislaurate, ethylenebisstearate, ethylenebishydroxystearate, ethylenebisbehenamide, hexamethylenebisstearate, hexamethylenebisbehenamide, hexamethylenehydroxystearate, ethylenebisoleamide, ethylenebiserucamide, hexamethylenebisoleamide, N,N'-distearyladipamide, N,N'-distearylsebacinamide, N,N'-dioleyladipamide, and N,N'-dioleylsebacinamide. Methylolamide: Methylolamide is represented by the following general formula (5). General formula (5) R10-CONHCH2OH (In the formula, R10 represents the residue obtained by removing the COOH group from a fatty acid.) Specific examples of methylolamides include methylol palmitate, methylol stearate, methylol behenate, methylol hydroxystearate, methylol oleate, and methylol erucate. • Esteramides: Esteramides are represented by the following general formula (6). General formula (6) R11-CONH-R12-OCO-R13 (In the formula, R11 and R13 represent residues obtained by removing the COOH group from a fatty acid, and may be the same or different, while R12 represents an alkylene group or arylene group having 1 to 10 carbon atoms.) Specific examples of esteramides include stearamidoethyl stearate and oleylamidoethyl urearate. The melting point of the fatty acid amide is preferably between 50°C and 150°C. Furthermore, the fatty acids constituting the fatty acid amide are preferably saturated fatty acids having 12 to 22 carbon atoms and / or unsaturated fatty acids having 16 to 25 carbon atoms, and more preferably saturated fatty acids having 16 to 18 carbon atoms and / or unsaturated fatty acids 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.

[0046] (Cellulose acetate propionate resin as an anti-blocking agent) As the cellulose acetate propionate resin, cellulose acetate propionate resins that have been conventionally used in gravure ink compositions and the like can be used. Cellulose acetate propionate resin is obtained by triesterinating cellulose with acetic acid and propionic acid, followed by hydrolysis. Generally, commercially available resins contain 0.6 to 2.5% by mass of acetyl groups, 42 to 46% by mass of propionate groups, and 1.8 to 5% by mass of hydroxyl groups. The amount of cellulose acetate propionate resin used in the organic solvent-based gravure printing high-solid ink composition of the present invention is preferably in the range of 3.0% by mass or less.

[0047] (Cellulose acetate butyrate resin as an anti-blocking agent) As the cellulose acetate butyrate resin, a cellulose acetate butyrate resin that has been conventionally used in gravure ink compositions and the like can be used. Cellulose acetate butyrate resin is obtained by triesterination with acetic acid and butyric acid, followed by hydrolysis. Generally, commercially available resins contain 2-30% by mass of acetylation, 17-53% by mass of butyrylation, and 1-5% of hydroxyl groups. The amount of cellulose acetate butyrate resin used in the organic solvent-based gravure printing high-solid ink composition of the present invention is preferably in the range of 0.1-3.0% by mass.

[0048] (Nitrogen cotton as an anti-blocking agent) As the nitrated cotton, nitrated cotton that has been conventionally used in gravure ink compositions and the like can be used. Nitrated cotton is obtained as a nitrate ester by reacting natural cellulose with nitric acid, thereby substituting three hydroxyl groups in the six-membered ring of the anhydrous glucopyranose group in the natural cellulose with nitrate groups. The nitrated cotton used in the present invention preferably has a nitrogen content of 10-13% and an average degree of polymerization of 35-90. Specific examples include SS1 / 2, SS1 / 4, SS1 / 8, TR1 / 16, NC RS-2 (manufactured by KCNC, KOREA CNC LTD), etc. The amount of nitrated cotton used is preferably in the range of 2.0% by mass or less in the organic solvent-based gravure printing high-solid ink composition obtained by the manufacturing method of the present invention.

[0049] (Pigment dispersant) As pigment dispersants, polyester-based pigment dispersants that can be used in ink compositions such as gravure ink compositions containing organic solvents can be used. Specifically, examples include Azisper PB821, PB822, PB824, PB881 (manufactured by Ajinomoto Fine Techno Co., Ltd.), Solspers 24000, 56000 (manufactured by Nippon Lubrizol Co., Ltd.), and among these, basic group-containing polyester-based polymer dispersants can be preferably used. The pigment dispersant content is preferably 1 to 200 parts by mass, and more preferably 1 to 60 parts by mass, per 100 parts by mass of the total pigment.

[0050] (water) Although the polyurethane polyurea resin solution contains water, the water content in the organic solvent-based gravure printing high-solid ink composition is preferably 10% by mass or less, and more preferably in the range of 0.1 to 5.0% by mass, in order to mitigate printing defects caused by static electricity, prevent plate fogging, and improve cell reproducibility.

[0051] <Method for producing organic solvent-based high-solid ink compositions for gravure printing> Known methods can be used to produce the organic solvent-based high-solid ink composition for gravure printing of the present invention using each of the constituent materials. Specifically, for example, a mixture of polyurethane polyurea resin solution, pigment, optionally binder resin, organic solvent, and pigment dispersant can be kneaded using a high-speed mixer, ball mill, sand mill, attritor, etc., and then the remaining materials such as adhesion improver, anti-blocking agent, organic solvent, antistatic agent, and water can be added and mixed to obtain the composition.

[0052] <Method for producing laminated printed materials using an organic solvent-based high-solid ink composition for gravure printing obtained by the manufacturing method of the present invention> A method for obtaining laminated printed materials using an organic solvent-based high-solid ink composition for gravure printing obtained by the manufacturing method of the present invention will be described. A method for obtaining a laminated printed material includes at least the following printing method: For example, a known resin film used as a substrate for lamination is printed at least once with a gravure printing ink composition using a gravure printing method. Then, another gravure printing ink composition is printed using a gravure printing method on any location on the surface side (the lower layer side when viewed from the surface layer after final lamination) of the gravure printing ink composition formed by these printings, and dried with a dryer. Laminated printed materials for packaging bags and the like can be obtained by laminating a resin film or the like onto the layer of organic solvent-based gravure printing high-solid ink composition obtained by the above method. Lamination methods include extrusion lamination, in which an anchor coating agent is applied to the surface of the printed material and then a molten polymer is laminated; and dry lamination, in which an adhesive is applied to the surface of the printed material and then a film-like polymer is bonded to it.

[0053] The above extrusion lamination method involves applying an anchor coating agent such as titanium-based, urethane-based, imine-based, or polybutadiene-based, as needed, to the surface of a printed material containing a layer of organic solvent-based high-solid ink composition for gravure printing, and then laminating molten polymer using a known extrusion laminating machine. Furthermore, the molten resin can be used as an intermediate layer to laminate in a sandwich-like manner with other materials. The molten polymer used in the extrusion lamination method described above can be conventionally used resins such as low-density polyethylene, ethylene-vinyl acetate copolymer, and polypropylene. Among these, the effectiveness of the present invention is enhanced when low-density polyethylene, which is easily oxidized during melting to generate carbonyl groups, is used.

[0054] Furthermore, the above-described dry lamination method involves applying an adhesive such as a urethane-based or isocyanate-based adhesive to the surface of a layer made of an organic solvent-based high-solid ink composition for gravure printing, and then laminating a film-like polymer using a known dry laminating machine. Polyethylene, unoriented polypropylene, and the like can be used as the resin for the film used in the dry lamination method. In particular, to obtain packaging materials for retort applications, aluminum foil can be laminated between the base material and the resin film to which it is bonded. Such laminated products can then be used for boiling and retort applications after being made into bags and filled with contents. Examples of the resin film used at this time include stretched and non-stretched polyolefins such as polyethylene and polypropylene, polyester, nylon, cellophane, vinylon, etc. Furthermore, for these resin films, films obtained by processing the resin film in advance, such as coating, kneading, surface coating, and kneading of an anti-fogging agent, can also be used.

Examples

[0055] Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to only these examples. Unless otherwise specified, “%” means “mass %” and “parts” means “parts by mass”. Also, the numbers of the amounts of each material in the table are also “parts by mass”. The unit of acid value is mgKOH / g.

[0056] <Method for producing ketimine solution 1> 51 parts of isophoronediamine, 31.2 parts of N-(2-hydroxyethyl)ethylenediamine, and 174 parts of acetone were mixed and stirred at room temperature for 1 hour to obtain ketimine solution 1.

[0057] <Method for producing ketimine solution 2> 51 parts of isophoronediamine, 31.2 parts of N-(2-hydroxyethyl)ethylenediamine, and 258 parts of diethyl ketone were mixed and stirred at room temperature for 1 hour to obtain ketimine solution 3.

[0058] The polyurethane resin varnish is described as PU. <Method for producing PU-1 (ketiminization with acetone)> Into a four-necked flask equipped with a stirrer, a cooling tube, and a nitrogen gas introduction tube, 400 parts of 3-methyl-1,5-pentylene adipate diol having a number average molecular weight of 4000, 33.3 parts of isophorone diisocyanate, and 0.04 part of tetrabutyl titanate were charged, and reacted at 90 to 100 ° C for 6 hours while introducing nitrogen gas. Next, 812 parts of propyl acetate and 203 parts of isopropyl alcohol were added, and then it was cooled to near room temperature. 32.29 parts of ketimine solution 1 was added and stirred for 50 minutes to obtain PU-1 with a weight average molecular weight of 35,000 (solid content 30%).

[0059] <Method for producing PU-2 (ketimine formation with diethyl ketone)> Into a four-necked flask equipped with a stirrer, a cooling tube, and a nitrogen gas inlet tube, 400 parts of 3-methyl-1,5-pentylene adipate diol with a number average molecular weight of 4000, 33.3 parts of isophorone diisocyanate, and 0.04 part of tetrabutyl titanate were charged, and reacted at 90 - 100 °C for 6 hours while introducing nitrogen gas. Next, 803 parts of propyl acetate and 201 parts of isopropyl alcohol were added, and then it was cooled to near room temperature. 42.88 parts of ketimine solution 2 was added and stirred for 50 minutes to obtain PU-2 with a weight average molecular weight of 35,000 (solid content 30%).

[0060] <Method for producing PU-3 (ketimine formation with acetone)> Into a four-necked flask equipped with a stirrer, a cooling tube, and a nitrogen gas inlet tube, 400 parts of 3-methyl-1,5-pentylene adipate diol with a number average molecular weight of 4000, 33.3 parts of isophorone diisocyanate, and 0.04 part of tetrabutyl titanate were charged, and reacted at 90 - 100 °C for 6 hours while introducing nitrogen gas. Next, 810 parts of propyl acetate and 202 parts of isopropyl alcohol were added, and then it was cooled to near room temperature. 30.78 parts of ketimine solution 1 was added and stirred for 50 minutes to obtain PU-3 with a weight average molecular weight of 40,000 (solid content 30%).

[0061] <Method for producing PU-4 (ketimine formation with acetone)> Into a four-necked flask equipped with a stirrer, a cooling tube, and a nitrogen gas inlet tube, 400 parts of 3-methyl-1,5-pentylene adipate diol with a number average molecular weight of 4000, 33.3 parts of isophorone diisocyanate, and 0.04 part of tetrabutyl titanate were charged, and reacted at 90 - 100 °C for 6 hours while introducing nitrogen gas. After adding 810 parts of propyl acetate and 202 parts of isopropyl alcohol, it was cooled to near room temperature, 36.56 parts of ketimine solution 1 was added, and it was stirred for 50 minutes to obtain a PU-4 with a weight average molecular weight of 25,000 (solid content 30%).

[0062] <Production method of PU-5 (ketimine formation with monoethanolamine and acetone)> Into a four-necked flask equipped with a stirrer, a cooling pipe, and a nitrogen gas introduction pipe, 400 parts of 3-methyl-1,5-pentylene adipate diol with a number average molecular weight of 4000, 33.3 parts of isophorone diisocyanate, and 0.04 part of tetrabutyl titanate were charged, and it was reacted at 90 - 100 °C for 6 hours while introducing nitrogen gas. After adding 810 parts of propyl acetate and 202 parts of isopropyl alcohol, it was cooled to near room temperature, 0.6 part of monoethanolamine was added and stirred for 15 minutes, then 32.39 parts of ketimine solution 1 was further added and stirred for 50 minutes to obtain a PU-5 with a weight average molecular weight of 25,000 (solid content 30%).

[0063] <Production method of PU-6 (ketimine formation with biomass, monoethanolamine and acetone)> Into a four-necked flask equipped with a stirrer, a cooling pipe, and a nitrogen gas introduction pipe, 400 parts of a polyester diol with an average molecular weight of 4000 obtained from sebacic acid (derived from castor oil) / succinic acid (derived from plants) = 70 / 30 (mass ratio) and 1,3-propanediol (derived from plants), 33.3 parts of isophorone diisocyanate, and 0.04 part of tetrabutyl titanate were charged, and it was reacted at 90 - 100 °C for 6 hours while introducing nitrogen gas. After adding 810 parts of propyl acetate and 202 parts of isopropyl alcohol, it was cooled to near room temperature, 0.6 part of monoethanolamine was added and stirred for 15 minutes, then 32.39 parts of ketimine solution 1 was further added and stirred for 50 minutes to obtain a PU-6 with a weight average molecular weight of 25,000 (solid content 30%).

[0064] <Production method of PU-7 (ketimine formation with water and acetone)> Into a four-necked flask equipped with a stirrer, a cooling tube, and a nitrogen gas introduction tube, 400 parts of 3-methyl-1,5-pentylene adipate diol with a number average molecular weight of 4000, 33.3 parts of isophorone diisocyanate, and 0.04 part of tetrabutyl titanate were charged, and the reaction was carried out at 90 to 100 °C for 6 hours while introducing nitrogen gas. Subsequently, 812 parts of propyl acetate and 203 parts of isopropyl alcohol were added, and after cooling to near room temperature, 32.29 parts of ketimine solution 1 was added and stirred for 20 minutes. Then, 3 parts of water was added and stirred for 15 minutes to obtain PU-7 (solid content 30%) with a weight average molecular weight of 35,000 and an amine value of 6.5.

[0065] <Production method of PU-8 (ketimine formation with water and diethyl ketone)> Into a four-necked flask equipped with a stirrer, a cooling tube, and a nitrogen gas introduction tube, 400 parts of 3-methyl-1,5-pentylene adipate diol with a number average molecular weight of 4000, 33.3 parts of isophorone diisocyanate, and 0.04 part of tetrabutyl titanate were charged, and the reaction was carried out at 90 to 100 °C for 6 hours while introducing nitrogen gas. Subsequently, 803 parts of propyl acetate and 201 parts of isopropyl alcohol were added, and after cooling to near room temperature, 42.88 parts of ketimine solution 2 was added and stirred for 20 minutes. Then, 3 parts of water was added and stirred for 15 minutes to obtain PU-8 (solid content 30%) with a weight average molecular weight of 35,000 and an amine value of 6.5.

[0066] <Production method of PU-⑨ (ketimine formation with water and acetone)> Into a four-necked flask equipped with a stirrer, a cooling tube, and a nitrogen gas introduction tube, 400 parts of 3-methyl-1,5-pentylene adipate diol with a number average molecular weight of 4000, 33.3 parts of isophorone diisocyanate, and 0.04 part of tetrabutyl titanate were charged, and the reaction was carried out at 90 to 100 °C for 6 hours while introducing nitrogen gas. Subsequently, 810 parts of propyl acetate and 202 parts of isopropyl alcohol were added, and after cooling to near room temperature, 30.78 parts of ketimine solution 1 was added and stirred for 20 minutes. Then, 3 parts of water was added and stirred for 15 minutes to obtain PU-9 (solid content 30%) with a weight average molecular weight of 40,000 and an amine value of 5.57.

[0067] <Production method of PU-10 (ketimine formation with water and acetone)> Into a four-necked flask equipped with a stirrer, a cooling pipe, and a nitrogen gas inlet pipe, 400 parts of 3-methyl-1,5-pentylene adipate diol with a number average molecular weight of 4000, 33.3 parts of isophorone diisocyanate, and 0.04 part of tetrabutyl titanate were charged, and the reaction was carried out at 90-100 °C for 6 hours while introducing nitrogen gas. After adding 810 parts of propyl acetate and 202 parts of isopropyl alcohol, it was cooled to near room temperature, 36.56 parts of ketimine solution 1 was added and stirred for 20 minutes, then 3 parts of water was further added and stirred for 15 minutes, and stirred for 50 minutes to obtain PU-10 (solid content 30%) with a weight average molecular weight of 25,000 and an amine value of 8.95.

[0068] <Production method of PU-11 (ketimine formation with water, monoethanolamine, and acetone)> Into a four-necked flask equipped with a stirrer, a cooling pipe, and a nitrogen gas inlet pipe, 400 parts of 3-methyl-1,5-pentylene adipate diol with a number average molecular weight of 4000, 33.3 parts of isophorone diisocyanate, and 0.04 part of tetrabutyl titanate were charged, and the reaction was carried out at 90-100 °C for 6 hours while introducing nitrogen gas. After adding 810 parts of propyl acetate and 201 parts of isopropyl alcohol, it was cooled to near room temperature, 0.6 part of monoethanolamine was added and stirred for 15 minutes, then 32.3 parts of ketimine solution 1 was further added and stirred for 20 minutes, then 3 parts of water was added and stirred for 15 minutes to obtain PU-11 (solid content 30%) with a weight average molecular weight of 25,000 and an amine value of 7.74.

[0069] <Production method of PU-12 (ketimine formation with water, biomass, monoethanolamine, and acetone)> Into a four-necked flask equipped with a stirrer, a cooling tube, and a nitrogen gas inlet tube, 400 parts of a polyester diol with an average molecular weight of 4,000 obtained from sebacic acid (derived from castor oil) / succinic acid (derived from plants) = 70 / 30 (mass ratio) and 1,3-propanediol (derived from plants), 33.3 parts of isophorone diisocyanate, and 0.04 part of tetrabutyl titanate were charged, and the reaction was carried out at 90 to 100 °C for 6 hours while introducing nitrogen gas. After adding 810 parts of propyl acetate and 201 parts of isopropyl alcohol, it was cooled to near room temperature, 0.6 part of monoethanolamine was added and stirred for 15 minutes, then 32.35 parts of ketimine solution 1 was added and stirred for 20 minutes, and further 3 parts of water was added and stirred for 15 minutes to obtain PU-12 (solid content 30%) with a weight average molecular weight of 45,000 and an amine value of 7.74.

[0070] <Manufacturing method of PU-13 (without ketimine formation)> Into a four-necked flask equipped with a stirrer, a cooling tube, and a nitrogen gas inlet tube, 400 parts of 3-methyl-1,5-pentylene adipate diol with an average molecular weight of 4,000, 33.3 parts of isophorone diisocyanate, and 0.04 part of tetrabutyl titanate were charged, and the reaction was carried out at 90 to 100 °C for 6 hours while introducing nitrogen gas. Next, after adding 813.5 parts of propyl acetate and 202.8 parts of isopropyl alcohol, it was cooled to near room temperature, 4.3 parts by mass of monoethanolamine was added and stirred for 20 minutes, then 1.26 parts of isophorone diamine and 0.77 part of N-(2-hydroxyethyl)ethylenediamine were added and stirred for 20 minutes to obtain PU-13 (solid content 30%) with a weight average molecular weight of 25,000 and an amine value of 0.

[0071] <Manufacturing method of PU-14 (ketimine formation with acetone after chain extension)> Into a four-necked flask equipped with a stirrer, a cooling tube, and a nitrogen gas inlet tube, 400 parts of 3-methyl-1,5-pentylene adipate diol with an average molecular weight of 4,000, 33.3 parts of isophorone diisocyanate, and 0.04 part of tetrabutyl titanate were charged, and the reaction was carried out at 90 to 100 °C for 6 hours while introducing nitrogen gas. Next, 803 parts of propyl acetate and 201 parts of isopropyl alcohol were added, and the mixture was cooled to near room temperature. Then, 6.43 parts of isophorone diamine and 3.93 parts of N-(2-hydroxyethyl)ethylenediamine were added, and the mixture was stirred for 20 minutes to allow chain extension and halt the reaction. After that, 21.93 parts of acetone were added and the mixture was stirred for 60 minutes to obtain PU-14 (30% solids) with a weight-average molecular weight of 35,000.

[0072] (Vinyl chloride-vinyl acetate resin) Solvine TA-3, manufactured by Nisshin Chemical Industry Co., Ltd.

[0073] (Pigment) Titanium dioxide: R-960, manufactured by DuPont. Phthalocyanine blue: CIPB15:4

[0074] (Adhesion enhancer) <Rosin and its derivatives> Polymerized rosin (acid value 160 mg KOH / g)

[0075] <Chlorinated polypropylene> 40 parts by mass of chlorinated polypropylene (50% solids content) with a degree of chlorination of 40% and a number average molecular weight of 100,000 was mixed and stirred with 60 parts by mass of methylcyclohexane to obtain chlorinated polypropylene varnish 1 with a solids content of 20%.

[0076] <Dammar resin> A dammar resin solution with a solid content of 50% was obtained by dissolving 50 parts of commercially available natural dammar resin (solid) in 50 parts of methylcyclohexane.

[0077] <Silica particles> Average particle size: 4.5μm

[0078] <Polyethylene wax> Average particle size: 2.11μm

[0079] <Fatty acid amide> Ethylenebis-stearamide

[0080] <Examples of manufacturing each ink composition in the examples and comparative examples> Pigments, polyurethane polyurea resin varnishes (PU-1 to PU-14), silica, and solvents were kneaded using paint conditioner manufactured by Red Devil to obtain the ink compositions of the examples and comparative examples shown in Table 1.

[0081] <Stability of ink composition over time> The ink compositions of the examples and comparative examples obtained above were collected in glass bottles, and the change in viscosity value before and after 14 days at 40°C was evaluated. The viscosity stability over time was evaluated from the ink viscosity measurement data at 30 rpm using a Type B viscometer (Tokyo Keiki Co., Ltd.) with rotor No. 2, where the viscosity was measured at a liquid temperature of 25°C, and evaluated according to the following evaluation criteria. The results are shown in Table 1. ○: The viscosity ratio before / after time was less than 1.5. ×: The viscosity ratio before / after time was 1.5 or higher.

[0082] <Print> 100 parts by mass of each ink composition from the examples and comparative examples were diluted with a mixed solvent (ethyl acetate / propyl acetate / isopropyl alcohol = 50 / 25 / 25, by mass ratio), and the viscosity was adjusted to 15 seconds using a Zaan Cup No. 3 manufactured by Rigosha. Each diluted ink composition was printed onto the surface of various films using a gravure printing machine under the following conditions, and dried to obtain printed materials. The amine odor was also evaluated using the obtained printed materials. The specific evaluation method is shown below. (Printing method / printing conditions) Room conditions during printing: Temperature 25°C, Humidity 50% Coating machine: Gravure printing machine Coating speed: 150 m / min Printing plate: Direct 175 lines, 28 μm solid color Drying temperature: 55℃

[0083] (Various types of film) OPP: Corona discharge treated biaxially oriented polypropylene film, Toyobo Co., Ltd. P-2161, 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, manufactured by Toyobo Co., Ltd., N-1102, thickness 15μm

[0084] (Printed material has a ketimin / amine odor) The odor of each printed material was evaluated by placing the nose against the printed surface. The results are shown in Table 1. A: No ketimine or amine odor is detected. B: A slight odor of ketimin and amines is noticeable. C: Ketimine and amine odors are present.

[0085] (Blocking resistance) The combined weight of the printed surface and the untreated surface of each film printout, one day after printing with each test ink, was 400 g / cm². 2 After applying a load and leaving the film at 40°C for 12 hours, the blocking resistance was evaluated based on the condition of each film after it was peeled off. A: The film should peel off with no resistance whatsoever, and the ink should not peel off the printed surface. B: There is some resistance when peeling off the film, but the ink does not peel off the printed surface. C: When peeling off the film, there is resistance, and the ink peels off from the printed surface.

[0086] (Guide role taken) Slipperiness was evaluated by the guide roll's position. The following method was used to test whether ink adhered to the guide roll after printing (guide roll removal) and to evaluate the printability. Note that if "guide roll removal" occurs, it negatively impacts the quality of the printed material, as ink that has adhered to the guide roll can transfer back to the printed surface, causing staining. The presence or absence of ink detachment from printed materials due to the guide rolls of a gravure printing press was visually evaluated. A: Something that doesn't exist B: Some C: Something that exists

[0087] (Adhesiveness) The adhesive properties of each printed material were evaluated by rubbing the printed surface twice with the pad of the thumb immediately after printing, then applying cellophane tape, and removing the tape, and measuring the ratio of the area where the ink film peeled off from the substrate. A: It doesn't peel off at all. B: The area that peels off is less than 20%. C: The area that peels off is 20% or more.

[0088] (Retort resistance) Each printed material, printed on NY and PET, one day after printing, contained 2.0 g / m² of solids. 2 After applying a certain amount of urethane-based adhesive (Takelac A-616 / Takenate A-65, manufactured by Mitsui Chemicals Polyurethane Co., Ltd.), an unoriented polypropylene film (RXC-3, 60 μm thick, manufactured by Tosello Co., Ltd.) was laminated using a dry laminating machine, and the laminated material was left at 40°C for 3 days to obtain a dry laminate. This dry laminate was made into a bag, filled with a mixture of 90% water and 10% salad oil by mass, and sealed. The retort resistance was evaluated by whether or not the laminated film floated when immersed in pressurized hot water at 135°C for 30 minutes. The evaluation criteria were the same as those for boiling suitability. A: No lamination lifting is visible at all. B: Pinhole-like or partially thin, short lamination lifts are visible. C: Long, streaky lamination is visible across the entire surface. -: The film used for printing itself is not suitable for retort processing, therefore no retort processing tests were conducted.

[0089] [Table 1] JPEG0007837676000002.jpg145170

[0090] According to the results of each embodiment, which is an example in accordance with the present invention, the printed material had no amine or ketimine odor, the ink composition exhibited excellent stability over time, and there was no contamination of the guide rolls. Furthermore, it exhibited excellent blocking resistance, adhesion, and retort resistance to various films. In contrast, Comparative Examples 1 and 3, which used polyurethane polyurea resin that had not undergone ketimine treatment, showed that the printed materials had an amine odor and a ketimine odor, and the ink composition exhibited poor stability over time. Furthermore, the adhesion to various films and retort resistance were not particularly good. Furthermore, in Comparative Examples 2 and 4, which used polyurethane polyurea resin ketiminated with acetone after chain elongation, the printed materials had an amine odor and a ketimine odor, and the ink composition had poor stability over time.

Claims

1. A high-solids ink composition for gravure printing containing a pigment, a binder resin, and an organic solvent, The aforementioned pigment is an organic pigment and / or an inorganic pigment. The binder resin contains the following polyurethane polyurea resins (A) and / or (B): The pigment and the binder resin satisfy the following conditions 1 to 3. A high-solids ink composition for gravure printing using an organic solvent, characterized by the following features. (A) One or more polyurethane polyurea resins selected from (A-2) below, with a weight-average molecular weight of 20,000 to 50,000. (A-2) A polyurethane polyurea resin obtained by reacting a urethane prepolymer, which is obtained by reacting a diol compound and a diisocyanate compound, with a reaction stopper in an organic solvent, and then extending the chain and stopping the reaction with a compound in which the amino group of a polyamine compound has been ketiminated by a ketone compound. (B) One or more polyurethane polyurea resins selected from (B-1) and (B-2) below, with a weight-average molecular weight of 20,000 to 50,000. (B-1) A polyurethane polyurea resin is obtained by adding a compound in which the amino group of a polyamine compound has been ketiminated by a ketone compound to a urethane prepolymer solution obtained by reacting a diol compound and a diisocyanate compound with an organic solvent, stirring and mixing, then adding water, and finally performing chain extension and reaction termination. (B-2) A polyurethane polyurea resin is obtained by reacting a diol compound with a diisocyanate compound to obtain a urethane prepolymer, then adding a reaction stopper to a urethane prepolymer solution of the urethane prepolymer and an organic solvent, and then adding a compound in which the amino group of the polyamine compound has been ketiminated by a ketone compound, and stirring and mixing the mixture, followed by adding water, and then performing chain extension and reaction cessation. (Condition 1) When the pigment is an organic pigment, the content of the organic pigment in the organic solvent-based gravure printing high-solid ink composition is 5 to 20% by mass. (Condition 2) When the pigment is an inorganic pigment, the content of the inorganic pigment in the organic solvent-based gravure printing high-solid ink composition is 30 to 70% by mass. (Condition 3) When the pigment includes both organic and inorganic pigments, the content of the organic pigment in the organic solvent-based gravure printing high-solid ink composition is 5 to 20% by mass, and the mass ratio of the inorganic pigment to the organic pigment {inorganic pigment (mass) / organic pigment (mass)} is 0 < inorganic pigment (mass) / organic pigment (mass) < 7.

0.

2. The organic solvent-based high-solid ink composition for gravure printing according to claim 1, wherein the polyurethane polyurea resin is one or more selected from polyurethane polyurea resins having a primary amino group at the terminal, polyurethane polyurea resins having a primary amino group and a secondary amino group at the terminal, and polyurethane polyurea resins having a group in which the primary amino group is ketiminated at the terminal.

3. The organic solvent-based high-solid ink composition for gravure printing according to claim 1 or 2, comprising a vinyl chloride / vinyl acetate copolymer and / or a vinyl chloride / acrylic copolymer as a binder resin.

4. A high-solids organic solvent-based ink composition for gravure printing according to any one of claims 1 to 3, comprising rosin and its derivatives, chlorinated polypropylene, dammar resin as an adhesion improver, and silica particles, polyethylene wax, fatty acid amide, cellulose acetate propionate resin, cellulose acetate butyrate resin, and nitrated cotton as an antiblocking agent.

5. The organic solvent is a mixed solvent of an ester-based organic solvent and an alcohol-based organic solvent, according to any one of claims 1 to 4.

6. The organic solvent-based high-solid ink composition for gravure printing according to claim 5, wherein the ratio of the ester-based organic solvent to the alcohol-based organic solvent used in the organic solvent-based high-solid ink composition is ester-based organic solvent / alcohol-based organic solvent = 50 / 50 to 95 / 5.

7. The organic solvent-based high-solid ink composition for gravure printing according to claim 5 or 6, wherein the organic solvent-based high-solid ink composition for gravure printing contains 5% by mass or more of propyl acetate as an ester-based organic solvent.

8. A gravure printing method using an organic solvent-based high-solid ink composition for gravure printing according to any one of claims 1 to 7, An organic solvent-based high-solid ink composition for gravure printing is prepared by adding an organic solvent to the aforementioned organic solvent-based high-solid ink composition for gravure printing and diluting it. A gravure printing method characterized by printing using the aforementioned organic solvent-based high-solids ink composition for gravure printing, and using a gravure printing method with a shallow gravure plate.

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