Printing ink composition for flexible packaging, printing method, printed material, and laminate.

Abstract

To provide a printing ink composition for soft packaging which can contribute to global warming prevention and environmental load reduction, and exhibits various physical properties such as excellent gradation reproducibility and printability even if it is used in soft packaging.SOLUTION: A printing ink composition for soft packaging contains A to C of (A) a pigment, (B) a polyurethane resin having a primary amino group and / or a secondary amino group at its terminal and a hydroxyl group at its terminal, (C) an organic solvent and water, wherein (B) the polyurethane resin contains a specific polymerization component, 10-100 mass% of the polyurethane resin is a biomass polyurethane resin, the biomass polyurethane resin contains a biomass polyurethane resin obtained by reaction of a bio-polyester polyol component with an isocyanate component, and the bio-polyester polyol component contains bio-polyester polyol obtained by reaction of a short-chain diol component which contains plant-derived diethylene glycol and has 2 to 10 carbon atoms with a carboxylic acid component.SELECTED DRAWING: None

Description

[Technical Field]

[0001] This invention relates to a printing ink composition for flexible packaging. More specifically, this invention relates to a printing ink composition for flexible packaging that has excellent physical properties such as gradation reproduction, blocking resistance, and lamination suitability. [Background technology]

[0002] In recent years, "biomass" has attracted attention as an industrial resource that is not a depletable resource. "Biomass" is defined as "renewable, organic resources of biological origin, excluding fossil resources." Furthermore, with the aim of environmental conservation, biomass polymers, which use biomass as a raw material, have been developed since the 1980s. Biomass polymers are considered useful as a measure to prevent global warming and are expected to be used as materials for a wide variety of products, including molded products, fibers, nonwoven fabrics, packaging, toners, inks, paints, films / sheets, foams, coatings, and adhesives. Patent document 1 discloses a bio-polyurethane resin with a high utilization rate of plant-derived raw materials. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2014-37552 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] When the bio-polyurethane resin described in Patent Document 1 is used as an ink composition, the gradation reproduction and printability are insufficient when used in flexible packaging. This invention has been made in view of the above-mentioned conventional problems, and aims to provide a printing ink composition for flexible packaging that can contribute to preventing global warming and reducing environmental impact, and that exhibits excellent gradation reproduction, printability, and other physical properties even when used in flexible packaging. [Means for solving the problem]

[0005] The present inventors, after diligent research to solve the above problems, have found that the present invention contains A to C: A. a pigment, B. a polyurethane resin having a primary amino group and / or a secondary amino group at the terminal and a hydroxyl group at the terminal, C. an organic solvent and water. The polyurethane resin of B contains a polyol component, an isocyanate component, a monoamino alcohol component, and a polyamine component containing a diamine component and a polyalkylene polyamine as polymerization components, and furthermore, 10 to 100% by mass of the polyurethane resin is biomass polyurethane resin. The biomass polyurethane resin includes a biomass polyurethane resin obtained by reacting a biopolyester polyol component with an isocyanate component. The biopolyester polyol component includes a biopolyester polyol obtained by reacting a plant-derived diethylene glycol-containing short-chain diol component having 2 to 10 carbon atoms with a carboxylic acid component. Printing ink composition for flexible packaging, By using this material, we discovered that it can contribute to preventing global warming and reducing environmental impact, and that it also exhibits excellent physical properties such as tonal reproduction and printability, thus completing the present invention. In other words, the present invention is as follows: 1.A. Pigments B. A polyurethane resin having a primary amino group and / or a secondary amino group at its terminus, and a hydroxyl group at its terminus. C. Organic solvents and water It contains A to C, The polyurethane resin of B contains a polyol component, an isocyanate component, a monoamino alcohol component, and a polyamine component containing a diamine component and a polyalkylene polyamine as polymerization components, and furthermore, 10 to 100% by mass of the polyurethane resin is biomass polyurethane resin. The biomass polyurethane resin includes a biomass polyurethane resin obtained by reacting a biopolyester polyol component with an isocyanate component. The biopolyester polyol component includes a biopolyester polyol obtained by reacting a plant-derived diethylene glycol-containing short-chain diol component having 2 to 10 carbon atoms with a carboxylic acid component. Printing ink composition for flexible packaging. 2. The printing ink composition for flexible packaging according to claim 1, wherein the biomass polyurethane resin has an amine value of 1.00 to 13.00 mgKOH / g and a hydroxyl value of 0.50 to 13.00 mgKOH / g. 3. The printing ink composition for flexible packaging according to claim 1 or 2, wherein the biopolyester polyol component comprises a biopolyester polyol obtained by reacting a plant-derived short-chain diol component having 2 to 4 carbon atoms, which includes plant-derived diethylene glycol, with a plant-derived carboxylic acid component. 4. The plant-derived short-chain diol component having 2 to 4 carbon atoms includes diethylene glycol and 1,3-propanediol. A printing ink composition for flexible packaging according to any one of claims 1 to 3, wherein the mass ratio of diethylene glycol to short-chain diols other than diethylene glycol is diethylene glycol / short-chain diols other than diethylene glycol = 10.0 / 90.0 to 90.0 / 10.0. 5. The printing ink composition for flexible packaging according to claim 3 or 4, wherein the plant-derived carboxylic acid component comprises one or more selected from the group consisting of sebacic acid, succinic acid, and dimer acid. 6. The plant-derived carboxylic acid components include sebacic acid and succinic acid. A printing ink composition for flexible packaging according to any one of 3 to 5, wherein the mass ratio of sebacic acid to succinic acid is sebacic acid / succinic acid = 10.0 / 90.0 to 90.0 / 10.0. 7. A printing ink composition for flexible packaging according to any one of 1 to 6, further comprising one or more compounds selected from the group consisting of vinyl chloride / vinyl acetate copolymers having hydroxyl groups, vinyl chloride / acrylic copolymers, and cellulose acetate propionate resins. 8. A printing method comprising printing on a resin film using a gravure printing machine with a flexible packaging printing ink composition described in any of 1 to 7. Printed material obtained using the printing method described in 9.8. A laminate obtained by laminating the printed material described in 10.9 with a substrate via a laminating adhesive. [Effects of the Invention]

[0006] The printing ink composition for flexible packaging of the present invention can contribute to preventing global warming and reducing environmental impact, and even when used in flexible packaging, it can provide excellent gradation reproduction, printability, and other good physical properties. [Modes for carrying out the invention]

[0007] <Printing ink composition for flexible packaging> The printing ink composition for flexible packaging of the present invention (hereinafter also referred to as "ink composition" in some cases) A. Pigments B. A polyurethane resin having a primary amino group and / or a secondary amino group at its terminus, and a hydroxyl group at its terminus. C. Organic solvents and water It contains A to C, B. The polyurethane resin contains a polyol component, an isocyanate component, a monoamino alcohol component, and a polyamine component containing a diamine component and a polyalkylene polyamine as polymerization components, and furthermore, 10 to 100% by mass of the polyurethane resin is biomass polyurethane resin. The biomass polyurethane resin includes a biomass polyurethane resin obtained by reacting a biopolyester polyol component with an isocyanate component. The biopolyester polyol component includes a biopolyester polyol obtained by reacting a plant-derived diethylene glycol-containing short-chain diol component having 2 to 10 carbon atoms with a carboxylic acid component. This is a printing ink composition for flexible packaging. The following explains each of these points.

[0008] <Pigments> Examples of pigments include inorganic, organic, and extender pigments that can generally be used in ink compositions containing organic solvents. Examples of inorganic pigments include titanium oxide, red iron oxide, antimony red, cadmium red, cadmium yellow, cobalt blue, ultramarine blue, phthalocyanine blue, carbon black, graphite, etc. Examples of organic pigments include soluble azo pigments, insoluble azo pigments, azo lake pigments, condensed azo pigments, copper phthalocyanine pigments, condensed polycyclic pigments, etc. Examples of extender pigments include calcium carbonate, kaolin clay, barium sulfate, aluminum hydroxide, talc, etc. The content of the pigment is not particularly limited as long as it is a content that enables printing colored with the ink composition. The pigment can be contained in the ink composition at 0.5 to 50.0% by mass. When the content of the pigment is less than 0.5% by mass, the coloring of the printed portion tends to be insufficient. On the other hand, when the content of the pigment exceeds 50.0% by mass, the printability tends to be insufficient.

[0009] <A polyurethane resin having a primary amino group and / or a secondary amino group at the terminal and a hydroxyl group at the terminal> The polyurethane resin in the present invention contains, as polymerization components, a polyol component, an isocyanate component, a monoamino alcohol component, and a polyamine component containing a diamine component and a polyalkylene polyamine. That is, this polyurethane resin has a primary amino group and / or a secondary amino group and a hydroxyl group at the terminal of the molecule. In other words, this polyurethane resin is formed by reacting components containing a polyol component, an isocyanate component, a monoamino alcohol component, and a polyamine component containing a diamine component and a polyalkylene polyamine. Furthermore, preferably, as the polymerization components, it contains a polyol component, a polyisocyanate component, a monoamino alcohol component, and a polyamine component containing a diamine component having no hydroxyl group and a diamine component having a hydroxyl group and a polyalkylene polyamine. That is, this polyurethane resin has a primary amino group and / or a secondary amino group at the molecular end, and has hydroxyl groups in the molecule and at the molecular end. In other words, this polyurethane resin is formed by reacting components including a polyol component, a polyisocyanate component, a monoamino alcohol component, and a polyamine component containing a diamine component having no hydroxyl group and a diamine component having a hydroxyl group and a polyalkylene polyamine component. And the polyurethane resin contains 10.0 to 100% by mass of a biomass polyurethane resin. The biomass polyurethane resin includes a biomass polyurethane resin obtained by reacting a biopolyester polyol component and an isocyanate component. The biopolyester polyol component may be a biopolyester polyol obtained by reacting a short-chain diol component having 2 to 10 carbon atoms including plant-derived diethylene glycol and a carboxylic acid component. This biomass polyurethane resin includes a resin having a structure obtained by reacting a biopolyester polyol component and a polyisocyanate component.

[0010] ((Among the polyurethane resins having a primary amino group and / or a secondary amino group at the end and having a hydroxyl group at the end, the biomass polyurethane resin)) 10.0 to 100% by mass of the above polyurethane resin in the present invention is a biomass polyurethane resin. And the remaining 0 to 90.0% by mass is a petroleum-derived polyurethane resin. Incidentally, it is preferable that the biomass polyurethane resin is contained in the binder resin in terms of solid content conversion at 10.0% by mass or more, more preferably 40.0% by mass or more, and even more preferably 100% by mass. The biomass polyurethane resin in the present invention will be described below. The biomass polyurethane resin in this invention is a resin obtained by reacting a biopolyester polyol component, an isocyanate component, the polyamine component and monoamino alcohol component described below, as polymerization components.

[0011] In the present invention, the biomass polyurethane resin is obtained by reacting the above components, and from the viewpoint of storage stability (pigment dispersibility) and printability, it is preferable that it contains at least one of a primary amino group or a secondary amino group at the terminal and also contains a hydroxyl group at the terminal. To exhibit even better adhesion, the amine value is preferably 1.00 mg KOH / g or more, more preferably 1.50 mg KOH / g or more, even more preferably 3.00 mg KOH / g or more, and preferably 13.00 mg KOH / g or less, and even more preferably 10.00 mg KOH / g or less. In addition, to exhibit even better adhesion, the hydroxyl value is preferably 0.50 mg KOH / g or more, more preferably 3.00 mg KOH / g or more, and also preferably 13.00 mg KOH / g or less, and even more preferably 10.00 mg KOH / g or less.

[0012] (Biopolyester polyol component) The biopolyester polyol component is preferably a biopolyester polyol obtained by reacting a short-chain diol component having 2 to 10 carbon atoms, which contains plant-derived diethylene glycol, with a carboxylic acid component derived from plants or petroleum. The plant-derived short-chain diol primarily has 2 to 4 carbon atoms. It is preferable to include 10.0% by mass or more of plant-derived diethylene glycol in a short-chain diol component having 2 to 4 carbon atoms, which contains plant-derived diethylene glycol, as this makes it easier to obtain excellent tonal gradation reproduction. Examples of short-chain diols with 2 to 10 carbon atoms other than plant-derived diethylene glycol include 1,3-propanediol, 1,4-butanediol, ethylene glycol, 1,2-propanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, and 2,4-diethyl-1,5-pentanediol pentyl glycol. Preferably, the plant-derived short-chain diol with 2 to 4 carbon atoms other than diethylene glycol is one or more plant-derived short-chain diols with 2 to 4 carbon atoms, such as 1,3-propanediol, 1,4-butanediol, and ethylene glycol, from an environmental perspective. In particular, it is even more preferable to use a plant-derived short-chain diol having 2 to 4 carbon atoms, which contains plant-derived diethylene glycol and plant-derived 1,3-propanediol.

[0013] When using plant-derived diethylene glycol and plant-derived 1,3-propanediol, the amount of plant-derived diethylene glycol is preferably 5.0% by mass or more, more preferably 20.0% by mass or more, and even more preferably 35.0% by mass or more, relative to the total mass of plant-derived diethylene glycol and plant-derived 1,3-propanediol. Furthermore, it is preferably 90.0% by mass or less, more preferably 70.0% by mass or less, even more preferably 60.0% by mass or less, and most preferably 55.0% by mass or less. These content ratios are the same when using two or more plant-derived diethylene glycols and plant-derived short-chain diols with 2 to 4 carbon atoms.

[0014] The 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, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, 1,9-nonanedicarboxylic acid, 1,10-decanedicarboxylic acid, thapsic acid, 1,12-dodecanedicarboxylic acid, 1,3-adamantanedicarboxylic acid, hexadecafluorosebacic acid, etc., and these may be used in combination. Preferably, from an environmental standpoint, it is preferable to include one or more selected from plant-derived sebacic acid, succinic acid, lactic acid, glutaric acid, dimer acid, azelaic acid, etc., and more preferably, one or more selected from plant-derived sebacic acid, succinic acid, and dimer acid. More preferably, the material comprises plant-derived sebacic acid and other plant-derived carboxylic acids. Furthermore, to achieve even better adhesion, it is preferable to use plant-derived sebacic acid and plant-derived succinic acid in combination. In that case, the amount of sebacic acid is preferably 10.0% by mass or more, more preferably 35.0% by mass or more, relative to the total mass of sebacic acid and succinic acid. Furthermore, it is preferably 90.0% by mass or less, and more preferably 65.0% by mass or less.

[0015] • Polyisocyanate components The polyisocyanate component is not particularly limited. For example, the polyisocyanate component may be obtained by mixing aromatic diisocyanate compounds such as tolylene diisocyanate, alicyclic diisocyanate compounds such as 1,4-cyclohexane diisocyanate and isophorone diisocyanate, aliphatic diisocyanate compounds such as hexamethylene diisocyanate, and aromatic aliphatic diisocyanate compounds such as α,α,α',α'-tetramethylxylylene diisocyanate. Biomass-derived polyisocyanate components can also be used. Furthermore, the ratio of the polyisocyanate component to the polyol component is preferably such that the equivalent ratio of isocyanate group to hydroxyl group (isocyanate index (II)) is 1.2 or higher. A ratio of 2.20 or lower is also preferable.

[0016] • Monoamino alcohol components The monoamino alcohol component functions as a reaction stopper, and examples include monoethanolamine, diethanolamine, monopropanolamine, monoisopropanolamine, diisopropanolamine, and 1-amino-2,3-propanediol. This results in the biomass polyurethane resin having hydroxyl groups at its molecular ends.

[0017] • Polyamine components The polyamine component functions as a chain extender and reaction inhibitor, and contains both a diamine component and a polyalkylene polyamine component. More preferably, the product contains a diamine component containing a diamine component without hydroxyl groups and a diamine component containing hydroxyl groups, and a polyamine component containing a polyalkylene polyamine component. Examples of diamine components include aliphatic diamines such as ethylenediamine, propylenediamine, tetramethylenediamine, and hexamethylenediamine; alicyclic diamines such as isophoronediamine and 4,4'-dicyclohexylmethanediamine, which do not have hydroxyl groups; and diamines with hydroxyl groups such as N-(2-hydroxyethyl)ethylenediamine, N-(2-hydroxyethyl)ethylenediamine, N-(2-hydroxyethyl)propylenediamine, and N,N'-di(2-hydroxyethyl)ethylenediamine. By introducing hydroxyl groups into the molecule of the biomass polyurethane resin using diamines with hydroxyl groups, the resolubility is improved. Among the diamines without hydroxyl groups, alicyclic diamines without hydroxyl groups are preferred. In this invention, polyalkylene polyamine components are used in combination to improve the cohesive strength and storage stability (pigment dispersibility) of the biomass polyurethane resin. Examples of polyalkylene polyamine components include diethylenetriamine and triethylenetetramine. In the present invention, it is more preferable to use polyalkylene polyamines, hydroxyl group-containing diamines, and hydroxyl group-free alicyclic diamines in combination with the above monoethanolamine.

[0018] (Components that can be added as needed during the synthesis of biomass polyurethane resin) During the synthesis of the biomass polyurethane resin in the present invention, diol compounds such as ethylene glycol, propylene glycol, 1,4-butanediol, neopentyl glycol, diethylene glycol, and triethylene glycol, and triol compounds such as glycerin may be used as chain extenders as needed. Monoalcohols such as methanol and ethanol, and alkylamines such as n-propylamine, n-butylamine, and di-n-butylamine may be used as reaction stoppers. By using triol compounds such as glycerin, a biomass polyurethane resin having hydroxyl groups in the side chain can also be obtained.

[0019] As a method for producing biomass polyurethane resin, for example, any of the following (1) to (5) can be used. (1) A method for obtaining a biomass polyurethane resin containing at least one of a primary amino group or a secondary amino group and a hydroxyl group at the end, by reacting a biopolyester polyol component and a polyisocyanate component to obtain a urethane prepolymer having isocyanate groups at the ends, adding a polyamine component as a chain extender to extend the chain, and then reacting a monoamino alcohol component as a reaction stopper, and then reacting a polyamine component as a reaction stopper. (2) A method for obtaining a biomass polyurethane resin containing at least one of a primary amino group or a secondary amino group and a hydroxyl group at the end, by reacting a biopolyester polyol component and a polyisocyanate component to obtain a urethane prepolymer having isocyanate groups at the ends, adding a polyamine component as a chain extender to extend the chain, and then simultaneously adding a monoamino alcohol component and a polyamine component as reaction stoppers to cause a reaction, thereby obtaining a biomass polyurethane resin containing at least one of a primary amino group or a secondary amino group and a hydroxyl group at the end. (3) A method for obtaining a biomass polyurethane resin containing at least one of a primary amino group or a secondary amino group and a hydroxyl group at the end, by reacting a urethane prepolymer having isocyanate groups at the ends, obtained by reacting a polyamine compound acting as a chain extender and reaction stopper, and a monoamino alcohol component acting as a reaction stopper, thereby simultaneously extending the chain and stopping the reaction. (4) A method for obtaining a biomass polyurethane resin containing at least one of a primary amino group or a secondary amino group and a hydroxyl group at the end, by reacting a urethane prepolymer having isocyanate groups at the ends, obtained by reacting a biopolyester polyol component and a polyisocyanate component, adding a monoamino alcohol component as a reaction stopper, and then adding a polyamine compound to simultaneously perform chain elongation and reaction stoppage. (5) A method for obtaining a biomass polyurethane resin containing at least one of a primary amino group or a secondary amino group and a hydroxyl group at the end, by reacting a biopolyester polyol component and a polyisocyanate component to obtain a urethane prepolymer having isocyanate groups at the ends, adding a portion of a polyamine compound to extend the chain, then adding a monoamino alcohol component which is a reaction stopper and allowing the reaction to proceed, and then adding the remaining polyamine compound to simultaneously extend the chain and stop the reaction. In the above methods (1) to (5) for obtaining biomass polyurethane resin, by using diamines having hydroxyl groups as the polyamine component, a polyurethane resin containing hydroxyl groups in its molecule can be obtained.

[0020] This section describes petroleum-derived polyurethane resins that can be used in combination with biomass polyurethane resins. As a petroleum-derived polyurethane resin, it contains a polyol component, a polyisocyanate component, a polyamine component containing a diamine component and a polyalkylene polyamine, and a monoamino alcohol component as polymerization components. In other words, it is formed by reacting a polyol component, a polyisocyanate component, a polyamine component meeting the following conditions, and a component containing a monoamino alcohol component. Examples of such petroleum-derived polyurethane resins include those that satisfy the following conditions (1) and (2), and optionally satisfy the following condition (3). (1) It contains at least one of a primary amino group or a secondary amino group at one end, and also contains a hydroxyl group at the other end. (2) The amine value is 1.00 to 13.00 mgKOH / g, and the hydroxyl value is 0.50 to 13.00 mgKOH / g. (3) The petroleum-derived polyurethane resin preferably contains a polyisocyanate component containing dicyclohexylmethane 4,4'-diisocyanate and isophorone diisocyanate, a polyol component, a polyamine component, and a monoamino alcohol component as polymerization components, and the polyol component more preferably contains a polyether polyol component and a polyester polyol component.

[0021] • Polyol components Examples of polyol compound components include polyester diol compounds such as polyether diol compounds obtained by condensing one or more dibasic acids such as polyethylene glycol and polypropylene glycol, and one or more glycols such as ethylene oxide and propylene oxide of bisphenol A, as well as polyester diol compounds such as polycaprolactone diols. Furthermore, in addition to the above-mentioned high-molecular-weight diol compound components, alkanediols such as 1,4-pentanediol, 2,5-hexanediol, and 3-methyl-1,5-pentanediol, or low-molecular-weight diol compound components such as ethylene glycol, propylene glycol, 1,4-butanediol, and 1,3-butanediol can be used individually or in combination of two or more, as long as the performance does not deteriorate.

[0022] • Polyisocyanate components Polyisocyanate compounds can be used as a mixture of one or more aromatic diisocyanate compounds such as tolylene diisocyanate, alicyclic diisocyanate compounds such as dicyclohexylmethane 4,4'-diisocyanate, 1,4-cyclohexane diisocyanate, and isophorone diisocyanate, aliphatic diisocyanate compounds such as hexamethylene diisocyanate, and aromatic aliphatic diisocyanate compounds such as α,α,α′,α′-tetramethylxylylene diisocyanate. As the polyisocyanate component, dicyclohexylmethane 4,4'-diisocyanate and isophorone diisocyanate are used in combination, considering resistance to roll contamination, impression cylinder staining, and ink leaching during overprinting in high temperature and humidity conditions. The mass ratio of dicyclohexylmethane 4,4'-diisocyanate to isophorone diisocyanate is preferably in the range of dicyclohexylmethane 4,4'-diisocyanate / isophorone diisocyanate = 95 / 5 to 10 / 90. Furthermore, the ratio of the polyisocyanate component to the polyol component used is such that the equivalent ratio of isocyanate groups to hydroxyl groups (isocyanate index (II)) is in the range of 1.2 to 2.3.

[0023] • Polyamine components The polyamine component contains both a diamine component and a polyalkylene polyamine component, and functions as a chain extender and reaction inhibitor. Examples of diamine components include aliphatic diamines such as ethylenediamine, propylenediamine, tetramethylenediamine, and hexamethylenediamine; alicyclic diamines such as isophoronediamine and 4,4'-dicyclohexylmethanediamine, which do not have hydroxyl groups; diamines with hydroxyl groups such as N-(2-hydroxyethyl)ethylenediamine, N-(2-hydroxyethyl)propylenediamine, and N,N'-di(2-hydroxyethyl)ethylenediamine; and diamine components such as aminoethylethanolamine. By introducing hydroxyl groups into the molecules of petroleum-derived polyurethane resins using diamines containing hydroxyl groups, the resolubility is improved. As for diamines that do not contain hydroxyl groups, those that do not contain hydroxyl groups and have an alicyclic structure are preferred. In this invention, polyalkylene polyamine components are used in combination to improve the cohesive strength and storage stability (pigment dispersibility) of petroleum-derived polyurethane resin. Examples of polyalkylene polyamine components include diethylenetriamine and triethylenetriamine.

[0024] • Monoamino alcohol components Examples of monoamino alcohol components include monoethanolamine, diethanolamine, monopropanolamine, monoisopropanolamine, diisopropanolamine, and 1-amino-2,3-propanediol, which are used as reaction inhibitors. This results in petroleum-derived polyurethane resin having hydroxyl groups at the molecular ends.

[0025] <Ingredients that can be added as needed> If necessary, diol compounds such as ethylene glycol, propylene glycol, 1,4-butanediol, neopentyl glycol, diethylene glycol, and triethylene glycol, and triol compounds such as glycerin can be used as chain extenders. Monoalcohols such as methanol and ethanol, and alkylamines such as n-propylamine, n-butylamine, and di-n-butylamine can be used as reaction stoppers. By using triol compounds such as glycerin, it is also possible to obtain petroleum-derived polyurethane resins having hydroxyl groups in the side chains.

[0026] As a method for producing petroleum-derived polyurethane resin, for example, any of the following (1) to (5) can be used. (1) A method for obtaining a polyurethane resin containing a urethane prepolymer having isocyanate groups at the terminals, obtained by reacting a polyol component and a polyisocyanate component, to which a polyamine component is added as a chain extender to extend the chain and obtain a urethane prepolymer having isocyanate groups at the terminals, then reacting with a monoamino alcohol component as a reaction stopper, and then reacting with a polyamine component to obtain a polyurethane resin containing at least one of a primary amino group or a secondary amino group at the terminals and containing a hydroxyl group at the terminals. (2) A method for obtaining a polyurethane resin containing a urethane prepolymer having isocyanate groups at the ends, obtained by reacting a polyol component and a polyisocyanate component, to which a polyamine component is added as a chain extender to extend the chain and obtain a urethane prepolymer having isocyanate groups at the ends, and then a monoamino alcohol component as a reaction stopper and a polyamine component are simultaneously added and reacted to obtain a polyurethane resin containing at least one of a primary amino group or a secondary amino group and a hydroxyl group at the ends. (3) A method for obtaining a polyurethane resin containing at least one of a primary amino group or a secondary amino group at each end, and containing a hydroxyl group at each end, by reacting a urethane prepolymer having isocyanate groups at the ends, obtained by reacting a polyamine compound acting as a chain extender and reaction stopper with a monoamino alcohol component acting as a reaction stopper, thereby simultaneously extending the chain and stopping the reaction, and simultaneously adding a reaction stopper which is a polyamine component having primary or secondary amino groups at both ends, and allowing the reaction to proceed. (4) A method for obtaining a polyurethane resin containing at least one of a primary amino group or a secondary amino group at each end, and containing a hydroxyl group at each end, by reacting a urethane prepolymer having isocyanate groups at the ends, which is obtained by reacting a polyol component and a polyisocyanate component, reacting a monoamino alcohol component which is a reaction stopper, then adding a polyamine compound to simultaneously extend the chain and stop the reaction, and simultaneously adding a reaction stopper which is a polyamine component which has primary or secondary amino groups at both ends, and reacting the two together. (5) A method for obtaining a polyurethane resin containing at least one of a primary amino group or a secondary amino group and a hydroxyl group at the end, by reacting a polyol component and a polyisocyanate component to obtain a urethane prepolymer having isocyanate groups at the ends, adding a portion of a polyamine compound to extend the chain, then adding a monoamino alcohol component which is a reaction stopper and allowing the reaction to proceed, and then adding the remaining polyamine compound to simultaneously extend the chain and stop the reaction. (1) to (5) In the method for obtaining polyurethane resin, by using diamines having hydroxyl groups as the polyamine component, a polyurethane resin containing hydroxyl groups in the molecule can be obtained.

[0027] The printing ink composition for flexible packaging of the present invention can be used as a printing ink composition for surface printing, a printing ink composition for lamination, a printing ink composition for shrink wrapping, etc. Depending on the application, the molecular weight, chemical structure, and equivalent ratio of each component may be appropriately adjusted based on the desired hardness of the biomass polyurethane resin, etc.

[0028] Examples of binder resins that can be used in combination with polyurethane resins include vinyl chloride / vinyl acetate copolymers, cellulose derivatives, polyamide resins, acrylic resins, dimer acid resins, maleic acid resins, petroleum resins, terpene resins, ketone resins, copal resins, and polypropylene oxide, which can be appropriately selected depending on the application of the ink composition.

[0029] • Organic solvents Organic solvents that can be used in ink compositions include toluene, ketone-based organic solvents (e.g., acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.), ester-based organic solvents (e.g., methyl acetate, ethyl acetate, n-propyl acetate, n-butyl acetate, isobutyl acetate, etc.), alcohol-based organic solvents (methanol, ethanol, n-propanol, isopropanol, butanol, etc.), and hydrocarbon-based solvents (toluene, methylcyclohexane, etc.). Furthermore, in consideration of environmental issues and the printability and drying properties of the ink, it is preferable to use a mixed solvent of an ester-based organic solvent and an alcohol-based organic solvent as the organic solvent in the ink composition during printing, such that the ratio of ester-based organic solvent to alcohol-based organic solvent is in the range of 50 / 50 to 95 / 5, preferably in the range of 60 / 40 to 85 / 15. Furthermore, from the viewpoint of the ink's printability, it is preferable to include 5% by mass or more, preferably 15% by mass or more, of propyl acetate in the ink composition during printing.

[0030] ·water Water is added to the ink composition in an amount of 0.1 to 10.0% by mass to impart fluidity to the ink composition of the present invention. The water content in the ink composition should be 0.1% by mass or more, and preferably 1.0% by mass or more. Furthermore, the water content should preferably be 9.0% by mass or less. If the water content is less than 0.1% by mass, the ink composition tends to have high viscosity. On the other hand, if the water content exceeds 10.0% by mass, the ink composition tends to lose its balance.

[0031] Additives that may be added as needed include adhesion enhancers such as rosin and its derivatives, chlorinated polypropylene, and dammar resin; anti-blocking agents such as silica particles, polyethylene wax, fatty acid amides, cellulose acetate butyrate resin, and cellulose acetate propionate resin; pigment dispersants, crosslinking agents, lubricants, leveling agents, surfactants, adhesion enhancers such as chlorinated polypropylene and dammar resin; anti-blocking agents such as silica particles, polyethylene wax, fatty acid amides, and polyamide resins; antistatic agents, antifungal agents, rust inhibitors, thickeners, antioxidants, UV absorbers, shelf-life enhancers, defoamers, chelating crosslinking agents, pH adjusters, surface modifiers, anti-aging agents, plasticizers, and humidifiers, which can be appropriately selected depending on the intended use of the ink composition.

[0032] <When the printing ink composition for flexible packaging of the present invention is used as a printing ink composition for flexible packaging lamination> When the printing ink composition for flexible packaging of the present invention is used as a printing ink composition for flexible packaging lamination, it may contain the following: vinyl chloride / vinyl acetate copolymer, vinyl chloride / acrylic copolymer, nitrated cotton, cellulose acetate propionate resin, other binder resins, etc. Furthermore, it may contain adhesion improvers such as the above-mentioned chlorinated polypropylene and dammar resin, antiblocking agents such as silica particles, polyethylene wax, fatty acid amide, cellulose acetate butyrate resin, and cellulose acetate propionate resin, as well as antistatic agents, defoaming agents, etc.

[0033] (Vinyl chloride / vinyl acetate copolymer) When the pigment is not sufficiently dispersed by polyurethane resin alone, or when it is necessary to improve the adhesion and lamination suitability of metal vapor-deposited films, etc., it is preferable that a vinyl chloride / vinyl acetate copolymer is used in combination with the printing ink composition for flexible packaging lamination. The vinyl chloride / vinyl acetate copolymer may be a copolymer of vinyl chloride monomer and vinyl acetate monomer, which has been conventionally used in gravure printing ink compositions. In particular, for organic solvent systems of inks that are environmentally friendly, a vinyl chloride / vinyl acetate copolymer having hydroxyl groups, preferably 50 to 200 hydroxyl groups, is preferred. Such a vinyl chloride / vinyl acetate copolymer having hydroxyl groups can be obtained by saponifying a portion of the acetate ester portion. In the case of a vinyl chloride / vinyl acetate copolymer 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 ink in an environmentally friendly organic solvent system. Formula 1 -CH2-CHCl- Formula 2 -CH2-CH(OCOCH3)- Formula 3 -CH2-CH(OH)- Specific examples of vinyl chloride / vinyl acetate copolymers having such hydroxyl groups include Solvine A, AL, TA5R, TA2, TA3, TAO, TAOL, C, CH, CN, and CNL, all manufactured by Nisshin Chemical Industry Co., Ltd. The total content of the polyurethane resin having a primary amino group and / or a secondary amino group at its terminus, and a hydroxyl group at its terminus, and the vinyl chloride / vinyl acetate copolymer is preferably 5 to 20% by mass in the printing ink composition for flexible packaging lamination.

[0034] (Vinyl chloride / acrylic copolymer) The main component is 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 blocks or randomly, 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, glycerin (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 described above preferably has a mass-average molecular weight of 10,000 to 70,000. Furthermore, from the standpoint of solubility in environmentally friendly organic solvents and adhesion to substrates, the vinyl chloride / acrylic copolymer preferably has a hydroxyl value of 50 to 200.

[0035] (Nitrocellulose, cellulose acetate propionate resin) The printing ink composition for flexible packaging lamination of the present invention may also contain nitrated cotton and cellulose acetate propionate resin in combination to improve blocking resistance. Nitrocellulose is preferably contained in the printing ink composition for flexible packaging laminates at a concentration of 0.1 to 2.0% by mass. Cellulose acetate propionate resin is preferably contained in the printing ink composition for flexible packaging laminates at a concentration of 0.1 to 3.0% by mass.

[0036] (Nitrosodium cellulose) Nitrate cotton can be the same type of nitrate cotton that has been conventionally used in gravure printing ink compositions. Nitrate cotton is obtained by reacting natural cellulose with nitric acid to replace three hydroxyl groups in the six-membered ring of the anhydrous glucopyranose group in the natural cellulose with nitrate groups, resulting in a nitrate ester. The nitrate cotton that can be used in the present invention preferably has a nitrogen content of 10-13% and an average degree of polymerization of 35-90. Specific examples of nitrate cotton include SS1 / 2, SS1 / 4, SS1 / 8, TR1 / 16, NC RS-2, (KCNC, KOREA CNC LTD), etc.

[0037] (Cellulose acetate propionate resin) The cellulose acetate propionate resin used may be the same cellulose acetate propionate resin that has been conventionally used in gravure printing ink compositions. Cellulose acetate propionate resin is obtained by triesterinating cellulose with acetic acid and propionic acid, followed by hydrolysis. Generally, commercially available resins contain 0.6-2.5% by weight of acetylation, 42.0-46.0% by weight of propionation, and 1.8-5.0% of hydroxyl groups. A specific example of cellulose acetate propionate resin is cellulose acetate propionate manufactured by Kanto Chemical Co., Ltd.

[0038] (Other binder resins) Furthermore, the ink composition of the present invention may also contain, as an auxiliary binder resin, cellulose acetate butyrate resin, acrylic resin, polyamide resin, rosin, rosin derivatives, or adhesive resins, provided that such additions do not degrade performance and cost considerations are taken into account.

[0039] (Adhesion enhancer) (Chlorinated polypropylene) As chlorinated polypropylene, those with a degree of chlorination of 20 to 50% are preferably used. Having a degree of chlorination within this range allows the chlorinated polypropylene to exhibit excellent compatibility with organic solvents and superior adhesion to films. In this invention, 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 be modified or unmodified chlorinated polypropylene with a mass-average molecular weight of 5,000 to 200,000. Having a mass-average molecular weight within this range allows the chlorinated polypropylene to exhibit excellent adhesion and superior solubility in organic solvents. When using chlorinated polypropylene, it is preferable to use it at a solid content mass percentage of 3.0% or less in the ink composition.

[0040] (Dammar resin) 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 using dammar resin, 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 printing ink compositions. Furthermore, when using dammar resin, it is preferable to use it at a solid content mass of 3.0% or less in the ink composition.

[0041] (Blocking prevention agent) (Silica particles) Silica particles can be naturally occurring, synthetic, crystalline, amorphous, hydrophobic, or hydrophilic. Preferably, the silica particles have an average particle diameter of 1.0 to 5.0 μm (the average particle diameter 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. Among these, hydrophilic silica particles are preferred. Ink compositions containing hydrophilic silica particles also promote ink wetting and spreading during overprinting, improving the overprinting effect (hereinafter sometimes referred to as "trapping properties"). When using silica particles, they should be used in an amount of 3.0% by mass or less, preferably 1.0% by mass or less, in the ink composition.

[0042] (Polyethylene wax) For the polyethylene wax used, an average particle size in the range of 1.0 to 3.0 μm is used (note that the average particle size refers to the particle size measured with #1: Honeywell Microtrac UPA). Because the polyethylene wax particle size is within the above range, the ink composition exhibits excellent slipperiness, blocking properties, and trapping properties. Furthermore, when using polyethylene wax, its content in the ink composition is preferably 1.5% by mass or less.

[0043] (Fatty acid amide) The fatty acid amide is not particularly limited as long as it has a residue obtained by removing the acid group from a fatty acid and an amide group. Examples of fatty acid amides include monoamides, substituted amides, bisamides, methylolamides, and esteramides, and it is preferable that at least one selected from the group consisting of monoamides, substituted amides, and bisamides is used in order to improve blocking resistance. The amount of fatty acid amide used in the ink composition is preferably in the range of 1.0% by mass or less.

[0044] 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 a fatty acid, and may be the same or different.)

[0045] 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.

[0046] • 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.

[0047] Methylolamide: Methylolamide is represented by the following general formula (5). General formula (5) R 10 -CONHCH2OH (In the formula, R 10 (This 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.

[0048] • Esteramides: Esteramides are represented by the following general formula (6). General formula (6) R 11 -CONH-R 12 -OCO-R 13 (In the formula, R 11 and R 13 R represents the residue obtained by removing the COOH group from a fatty acid, and it may be the same or different. 12 (This represents an alkylene or arylene group with 1 to 10 carbon atoms.) Specific examples of esteramides include stearylamide ethyl stearate and oleylamide ethyl stearate.

[0049] 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. More preferably saturated fatty acids are lauric acid, palmitic acid, stearic acid, behenic acid, and hydroxystearic acid, and more preferably unsaturated fatty acids are oleic acid and erucic acid.

[0050] (Antistatic agent) As antistatic agents, known agents that can be used in gravure printing inks can be used. Specific examples include coconut alkylbis(hydroxyethyl)methyl nitrate and coconut alkylbis(hydroxyethyl)methyl chloride, quaternary ammonium salt compounds (sulfates), quaternary ammonium salts (hydrochlorides) such as monoalkyltrimethylammonium chloride, monoalkylbenzyldimethylammonium chloride, and dialkyldimethylammonium chloride, thiocyanates, alkylimidazolines, and alkylimidazolium. When using an antistatic agent, it is preferable that the antistatic agent content in the ink composition be 3.0% by mass or less.

[0051] <Method for producing the ink composition of the present invention> The ink composition of the present invention can be produced by dispersing and kneading components such as A. pigment, B. polyurethane resin having a primary amino group and / or a secondary amino group at the terminal and a hydroxyl group at the terminal, preferably a polyurethane resin having a primary amino group and / or a secondary amino group at the terminal and a hydroxyl group both intramolecularly and at the terminal, C. organic solvent and water, and optionally other binder resins, using various known dispersion and kneading devices such as bead mills, ball mills, sand mills, attritors, roll mills, and pearl mills, then adding water and various optional components and stirring and mixing. The viscosity is then adjusted to 10 to 1000 mPa·s by adjusting the content of each component and the combination of binder resin and organic solvent. When used in gravure printing, it is preferable to dilute with an organic solvent such as an ester solvent or alcohol solvent until the viscosity is appropriate according to the printing conditions at the ambient temperature during printing, specifically until the flow time of Zahn Cup No. 3 is approximately 12 to 23 seconds / 25°C, or 14 to 16 seconds / 25°C for high-speed printing. In this case, the content of the polyurethane resin in the present invention is not particularly limited. For example, the content of the polyurethane resin in the printing ink composition for flexible packaging lamination is preferably 1.5% by mass or more, more preferably 6.0% by mass or more. It is also preferably 17.0% by mass or less, and more preferably 15.0% by mass or less. If the content of the polyurethane resin is less than 1.5% by mass, the storage stability tends to decrease. On the other hand, if the content of the polyurethane resin exceeds 17.0% by mass, the viscosity of the ink composition tends to increase.

[0052] <Printing method and printed material using the ink composition of the present invention> Next, a printing method using the ink composition of the present invention will be described. The printing method includes at least the following: For example, an ink composition is printed at least once on a resin film, which is a known substrate, using a gravure printing method. Then, another ink composition is printed on any location on the surface side of the printed ink layer formed by these printings using a gravure printing method, and the printed material is dried with a dryer. A printed material obtained by this method is also included in the present invention. Examples of resin films used as the base material in this case include stretched and unstretched polyolefins such as polyethylene and polypropylene, polyester, nylon, cellophane, vinylon, and styrene. Furthermore, films obtained by pre-processing these resin films, such as coating or kneading with an anti-fogging agent, or surface coating or kneading with a matting agent, can also be used. Furthermore, as these resin films, films can be used that have a barrier layer laminated onto various printing plastic films, such as films coated with metal vapor deposition or barrier resin.

[0053] <Laminate> A laminate for packaging bags and the like can be obtained by laminating a resin film or the like onto the ink composition layer of the printed material obtained by the above method using various methods. For this lamination, an extrusion lamination method can be used, in which a molten polymer is laminated after applying an anchor coating agent to the surface of the printed material, or without applying an anchor coating agent, and a dry lamination method can be used, in which a film-like polymer is bonded after applying a laminating adhesive to the surface of the printed material.

[0054] (Method for obtaining laminated products using a printing ink composition for flexible packaging lamination) Next, a method for obtaining a laminated product using the ink composition of the present invention will be described. In the present invention, the laminated product is, for example, made by first printing a non-white flexible packaging lamination ink composition onto a resin film once or more times using a gravure printing method. Then, optionally, a white flexible packaging lamination ink composition is printed onto the surface side of the colored ink layer for flexible packaging formed by these printings (the lower layer when viewed from the surface after final lamination) using a gravure printing method, and then dried with a dryer.

[0055] By laminating the obtained printed material with a layer of white ink composition for flexible packaging lamination using various lamination methods, a laminated product for packaging bags and the like can be obtained. Methods for obtaining this laminated product include an extrusion lamination method in which an anchor coating agent such as titanium-based, urethane-based, imine-based, or polybutadiene-based is applied to the surface of the printed material as needed, followed by lamination of a molten polymer; a dry lamination method in which an adhesive diluted to an appropriate viscosity with an organic solvent is applied to the surface of the printed material, followed by lamination of a film-like polymer; and a solvent-free lamination method in which a solvent-free adhesive is applied to the surface of the printed material, followed by lamination of a film-like polymer. The extrusion lamination method described above involves applying an anchor coating agent such as titanium-based, urethane-based, imine-based, or polybutadiene-based as needed to the surface of the printed material, followed by lamination of a molten polymer using a known extrusion laminating machine. Furthermore, the molten resin can be used as an intermediate layer to create a sandwich-like lamination with other materials.

[0056] 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 effects of the present invention are enhanced when used with low-density polyethylene, which is prone to oxidation during melting and the generation of carbonyl groups. Furthermore, the dry lamination method described above involves applying an adhesive such as a urethane-based or isocyanate-based adhesive, diluted to an appropriate viscosity with an organic solvent, to the surface of the printed material, drying, and then laminating a film-like polymer using a known dry laminating machine. The non-solvent lamination method described above involves applying an adhesive such as a urethane-based or isocyanate-based adhesive to the surface of the printed material, and then laminating a film-like polymer using a known dry laminating machine. Polyethylene, unoriented polypropylene, and the like can be used as resins for the films used in the dry lamination and non-solvent lamination methods. In particular, for packaging materials used in retort applications, aluminum foil can be sandwiched between the base material and the resin film to be laminated. Such laminated products can also be used for boiling and retort applications after being made into bags and filled with contents. The resin film used in this case is not particularly limited. Examples of resin films that can be used include polyester films such as polyethylene terephthalate (PET), polylactic acid, and polycaprolactone, various printing plastic films such as nylon and vinylon, and films in which a barrier layer is laminated onto these various printing plastic films by metal deposition or coating with a barrier resin. [Examples]

[0057] The present invention will be described more specifically below with reference to examples. The present invention is not limited in any way to these examples. Unless otherwise specified, "%" means "mass%" and "parts" means "parts by mass".

[0058] <Biomass polyurethane resin varnish> (Biomass polyurethane resin varnish 1) In a four-necked flask equipped with a stirrer, thermometer, and nitrogen gas inlet tube, 200.00 parts by mass of a biomass polyester polyol with a number average molecular weight of 2000, in which the weight ratio of diethylene glycol (plant-derived):1,3-propanediol (plant-derived) as the diol component is 50:50 and the weight ratio of sebacic acid (castor oil-derived):succinic acid (plant-derived) as the acid component is 40:60, and 33.30 parts by mass of isophorone diisocyanate were charged, and the mixture was reacted at 105°C for 6 hours under a nitrogen stream. The mixture was allowed to cool to near room temperature, and 393.50 parts by mass of ethyl acetate and 168.60 parts by mass of isopropyl alcohol were added. Then, 0.31 parts by mass of monoethanolamine was added and the mixture was reacted. Subsequently, 4.85 parts by mass of isophorone diamine, 1.98 parts by mass of N-(2-hydroxyethyl)propylenediamine, and 0.49 parts by mass of diethylenetriamine were added and the mixture was reacted to obtain biomass polyurethane resin varnish 1 (solid content 30% by mass, amine value 3.32 mg KOH / g, hydroxyl value 5.59 mg KOH / g).

[0059] (Biomass polyurethane resin varnish 2-16) In the production of the above-mentioned biomass polyurethane resin varnish 1, biomass polyurethane resin varnishes 2 to 16 were obtained by the same method as biomass polyurethane resin varnish 1, except that each component was changed to that of biomass polyurethane resin varnishes 2 to 16 in the table below.

[0060] [Table 1] JPEG0007833349000002.jpg95170

[0061] <Example of manufacturing a non-biomass polyurethane resin varnish (non-biomass polyurethane, amine value 4.51 mg KOH / g, hydroxyl value 5.24 mg KOH / g)> In a four-necked flask equipped with a stirrer, condenser, and nitrogen gas inlet, 100.00 parts by mass of 3-methyl-1,5-pentylene adipate diol with an average molecular weight of 2000, 100.00 parts by mass of polypropylene glycol with an average molecular weight of 2000, 16.67 parts by mass of isophorone diisocyanate, and 19.67 parts by mass of dicyclohexylmethane 4,4'-diisocyanate were charged, and the mixture was reacted at 100-105°C for 6 hours while introducing nitrogen gas. After cooling to near room temperature, 404.80 parts by mass of ethyl acetate and 173.49 parts by mass of isopropyl alcohol were added, followed by the addition of 6.45 parts by mass of isophorone diamine, 0.61 parts by mass of monoethanolamine, 1.31 parts by mass of N-(2-hydroxyethyl)ethylenediamine, and 0.29 parts by mass of diethylenetriamine, and the mixture was reacted to obtain a polyurethane resin varnish (solid content 30% by mass).

[0062] <Example of polyurethane manufacturing for comparative examples> Comparative Example 1 (Comparative biomass polyurethane resin varnish, amine value 4.40 mg KOH / g, OH value 6.10 mg KOH / g, synthesis without polyalkylene polyamine) In a four-necked flask equipped with a stirrer, condenser, and nitrogen gas inlet, 200.00 parts by mass of a polyester diol with an average molecular weight of 2000 obtained from sebaic acid (derived from castor oil) / succinic acid (derived from plants) = 40 / 60 (mass ratio) and diethylene glycol (derived from plants) / 1,3-propanediol (derived from plants) = 50 / 50 (mass ratio) and 33.30 parts by mass of isophorone diisocyanate were charged, and the mixture was reacted at 100-105°C for 6 hours while introducing nitrogen gas. After cooling to near room temperature, 394.10 parts by mass of ethyl acetate and 168.90 parts by mass of isopropyl alcohol were added, followed by the addition of 5.81 parts by mass of isophorone diamine, 0.92 parts by mass of monoethanolamine, and 1.18 parts by mass of N-(2-hydroxyethyl)ethylenediamine, and the mixture was reacted to obtain Biomass Polyurethane Resin Varnish 1 (Solid Content 30% by mass) of Comparative Example 1.

[0063] Comparative Example 2 (Synthesis of petroleum-derived polyurethane resin varnish with an amine value of 0.9 mg KOH / g) In a four-necked flask equipped with a stirrer, condenser, and nitrogen gas inlet, 400.00 parts of a polyester polyol with a number-average molecular weight of 4000, which is an adipate of petroleum-derived diethylene glycol / petroleum-derived neopentyl glycol = 50 / 50 (weight ratio), and 44.4 parts of isophorone diisocyanate were charged, and the mixture was reacted at 100-105°C for 6 hours while introducing nitrogen gas. After cooling to near room temperature, 760 parts of ethyl acetate were added, followed by 19.2 parts of isophorone diamine and 325 parts of isopropyl alcohol as a chain elongation inhibitor, and the mixture was reacted at 60°C for 3 hours to obtain Comparative Example 2, a petroleum-derived urethane resin varnish 2 (solid content 30% by mass).

[0064] <Example of manufacturing method for ink composition for flexible packaging lamination> The pigment (phthalocyanine blue CIPigment Blue 15:4), the above biomass polyurethane resin varnishes 1 to 19, the varnishes of Comparative Examples 1 and 2, and a vinyl chloride-vinyl acetate resin (Solvine TA-3, manufactured by Nisshin Chemical Industry Co., Ltd.) were kneaded using Red Devil's paint conditioner, and then a solvent (a mixture of the paint conditioner and the solvent) was added to obtain the flexible packaging laminating ink compositions shown in Table 1.

[0065] (Vinyl chloride / vinyl acetate copolymer) Solvine TA-3, Nisshin Chemical Industry Co., Ltd. (Polymerized rosin) Polymerized rosin: Acid value 160 mg KOH / g (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 a chlorinated polypropylene varnish with a solids content of 20%. (Silica particles) Average particle size: 4.5μm (Polyethylene wax) Average particle size: 2.11μm (Mixed solvent) Ethyl acetate / propyl acetate / isopropyl alcohol = 50 / 30 / 20

[0066] (evaluation) The performance of the flexible packaging laminating ink compositions obtained from Examples 1 to 19 and Comparative Examples 1 to 2 was evaluated using the following method, and the evaluation results are shown in Table 2. <Performance evaluation of ink compositions> (Storage stability) Each of the flexible packaging laminating ink compositions obtained from Examples 1-19 and Comparative Examples 1-2 was collected in a glass bottle and stored at an ambient temperature of 60°C for 14 days. The storage stability of the ink was evaluated based on whether or not pigment sedimentation occurred. A: No sedimentation was observed, indicating good storage stability of the ink. C: Sedimentation is observed, indicating poor storage stability of the ink.

[0067] (Print evaluation) Each of the flexible packaging laminating ink compositions of Examples 1-19 and Comparative Examples 1-2 was diluted with 50 parts by mass of the mixed solution according to the formulations in Table 2, and the viscosity was adjusted to 15 seconds using a Zaan Cup No. 3 from Rigosha Co., Ltd. Then, printing was performed on the OPP, PET, and NY surfaces at a printing speed of 60 m / min using a gravure printing press equipped with an engraving plate (printing plate, Helio 175 lines / inch).

[0068] (About the film) PET: Polyethylene terephthalate film with corona discharge treatment on one side, manufactured by Toyobo Co., Ltd., E-5102, 12 μm thick. OPP: Biaxially oriented polypropylene film, manufactured by Toyobo Co., Ltd., P-2161, 30 μm thickness NY: Nylon film, manufactured by Toyobo Co., Ltd., N-1102, thickness 15μm

[0069] (Adhesiveness) The adhesion of each printed material was evaluated by applying cellophane tape to the printed surface and then removing the tape, based on 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.

[0070] (Printability (streaking)) Printability was evaluated based on the percentage of streaky areas in the printed portion at the end of printing, which were caused by ink clogging in the printing plate. A: No smudging whatsoever. B: Some fading is visible. C: Many streaks are visible.

[0071] (Blocking resistance) The printing surfaces of each printed matter were overlapped with the corona discharge treatment surfaces of each film, a load of 3 kg / cm2 was applied, and they were left at a temperature of 45 °C for 1 day. Thereafter, the ink surface and the film surface were peeled off, and the transfer of the ink film to the film surface was evaluated. A: Those that peeled off without resistance and had no transfer of the ink film at all B: Those that had resistance but no transfer of the ink film at all C: Those in which less than 50% transfer of the ink film was observed D: Those in which 50 - 100% transfer of the ink film was observed

[0072] (Retort resistance) One day after printing on polyethylene terephthalate (PET) and nylon (NY), each printed matter was coated with a urethane-based adhesive (Takelac A - 616 / Takenate A - 65, Mitsui Chemicals SKC Polyurethane Co., Ltd.) in an amount of 2.0 g / m in terms of solid content. 2 After that, an unstretched polypropylene film (RXC - 22, thickness 60 μm, Mitsui Chemicals Toagosei Co., Ltd.) was laminated using a dry laminator and 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 wt% water and 10 wt% salad oil, sealed, and for the one printed on PET, the retort suitability was evaluated from the presence or absence of laminate lifting when immersed in pressurized hot water at 135 °C for 60 minutes. For the one printed on NY, the same test evaluation was carried out at 120 °C. By this evaluation, the laminate suitability can be confirmed. A: Those with no laminate lifting at all B: Those with pinhole - like or partially thin and short laminate lifting C: Those with long streak - like laminate lifting on the entire surface

[0073]

Table 2

[0074] According to the ink composition using the biomass polyurethane resin varnish of the examples along the present invention, all the results of storage stability, adhesiveness, printing suitability, blocking resistance, and retort resistance were good. In contrast, Comparative Example 1, which used a biomass polyurethane resin varnish that did not use polyalkylene polyamine components during synthesis, showed insufficient storage stability and could not perform printing to a degree sufficient for other evaluations. Furthermore, in Comparative Example 2, which used a varnish that did not utilize monoamino alcohol components or polyalkylene polyamine components during synthesis, and was not a biomass polyurethane resin, the storage stability was insufficient, and it was not possible to perform printing to a degree that would allow for other evaluations.

Claims

1. A. Pigments B. A polyurethane resin having a primary amino group and / or a secondary amino group at its terminal end, and a hydroxyl group at its terminal end. C. Organic solvents and water It contains A to C, The polyurethane resin in B contains a polyol component, an isocyanate component, a monoamino alcohol component, and a polyamine component containing a diamine component and a polyalkylene polyamine as polymerization components, and furthermore, 10 to 100% by mass of the polyurethane resin is biomass polyurethane resin. The biomass polyurethane resin includes a biomass polyurethane resin obtained by reacting a biopolyester polyol component with an isocyanate component. The biopolyester polyol component includes a biopolyester polyol obtained by reacting a plant-derived diethylene glycol-containing short-chain diol component having 2 to 10 carbon atoms with a carboxylic acid component. The biomass polyurethane resin has an amine value of 1.50 to 13.00 mg KOH / g and a hydroxyl value of 0.50 to 10.00 mg KOH / g, The carboxylic acid component includes sebacic acid and succinic acid. Printing ink composition for flexible packaging.

2. The printing ink composition for flexible packaging according to claim 1, wherein the biopolyester polyol component comprises a biopolyester polyol obtained by reacting a plant-derived short-chain diol component having 2 to 4 carbon atoms, which includes plant-derived diethylene glycol, with a carboxylic acid component containing sebacic acid and succinic acid.

3. The aforementioned plant-derived short-chain diol component having 2 to 4 carbon atoms includes diethylene glycol and 1,3-propanediol. The printing ink composition for flexible packaging according to claim 2, wherein the mass ratio of diethylene glycol to short-chain diols other than diethylene glycol is diethylene glycol / short-chain diols other than diethylene glycol = 10.0 / 90.0 to 90.0 / 10.

0.

4. The printing ink composition for flexible packaging according to claim 1, wherein the mass ratio of sebacic acid to succinic acid is sebacic acid / succinic acid = 10.0 / 90.0 to 90.0 / 10.

0.

5. The printing ink composition for flexible packaging according to claim 1, comprising one or more compounds selected from the group consisting of vinyl chloride / vinyl acetate copolymers having hydroxyl groups, vinyl chloride / acrylic copolymers, and cellulose acetate propionate resins.

6. A printing method comprising printing on a resin film using the flexible packaging printing ink composition described in claim 1 with a gravure printing press.

7. A printed material obtained by the printing method described in claim 6.

8. A laminate obtained by laminating the printed material described in claim 7 and a substrate via a laminating adhesive.

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