Liquid ink composition, printed matter, laminate, and package

Abstract

The present disclosure provides a liquid ink composition that reduces environmental load, has an excellent balance of blocking resistance, adhesion, and laminate strength, and suppresses detachment of an ink layer after boiling or retort treatment.SOLUTION: The present disclosure is a liquid ink composition containing a urethane resin component and an organic solvent, wherein the urethane resin component contains a urethane resin (I) obtained from a reaction raw material (I) containing a first polyol component containing a polydiene polyol and / or a hydrogenated polydiene polyol, a second polyol component containing a polyester polyol (I), and a polyisocyanate-based compound (I).SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present disclosure relates to a liquid ink composition, a printed matter, a laminate or a package. [Background technology]

[0002] Gravure inks and flexographic inks are widely used to impart aesthetic and functional properties to printed substrates. When the printed substrate is used as a packaging material, particularly food packaging, it is common for it to be laminated. Depending on the type of contents or intended use, various printing methods and lamination processes are used, such as front printing, which prints on the front side of a material such as a plastic film, or reverse printing, which reverses the orientation or color printing order of the printed image. Conventionally, inks used in this type of lamination process have widely used a combination of polyurethane resin and vinyl chloride-vinyl acetate copolymer resin as a binder resin that can achieve both excellent dispersibility and high film properties. This combination of polyurethane resin and vinyl chloride-vinyl acetate copolymer resin is an essential ink ingredient for achieving good printability and the various properties required for lamination inks (adhesion to substrates, lamination strength, boiling retort suitability).

[0003] However, in response to the trend toward building a recycling-oriented society that reduces substances that may have a negative impact on humans or the environment, as exemplified by the Sustainable Development Goals, legal regulations surrounding food packaging are becoming stricter worldwide. In particular, in recent years, there has been a demand for stricter regulations on the ingredients used in packaging and their migration into food. Furthermore, the movement toward eliminating plastic is accelerating, increasing demand for recyclable packaging. Therefore, in the development of gravure ink products, it has become necessary to design ink and packaging components using materials that are guaranteed to be safe for humans and the environment. In particular, vinyl chloride-vinyl acetate copolymer is of concern as a substance that hinders packaging recycling for the following reasons (a) and (b). (a) Chlorine-based resins such as vinyl chloride can cause corrosion of equipment or piping by releasing hydrogen chloride and generating hydrochloric acid during the thermal decomposition process of recycling. (b) In thermal recycling, which reuses the energy generated when waste is incinerated, the incineration of chlorine-based resins can result in the release of environmental hormones such as dioxins. Therefore, there will be a need to develop environmentally friendly inks, such as inks that are free of chlorine-based resins. For example, Patent Document 1 discloses a technology for an organic solvent-based gravure ink containing a pigment, an organic solvent, and a binder resin having a chlorine content of 5% by mass or less and containing a urethane resin (A) and a resin (B). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2022-139294 Summary of the Invention [Problem to be solved by the invention]

[0005] The above-mentioned Patent Document 1 examines blocking resistance, film adhesion, and lamination properties. However, it does not mention the problem that when gravure printing or flexographic printing is performed on a raw sheet of functional film, which exists in a wide variety depending on the purpose or application and has oxygen or water vapor barrier properties, adhesion between the raw sheet of film and the ink layer displaying information about the contents or a pattern evoking aesthetic appeal decreases, resulting in the loss of the information. In particular, with the increase in the amount and applications of functional films in recent years, noticeable detachment of the ink layer after boiling or retort processing, for example, has become a problem. Therefore, an object of the present disclosure is to provide a liquid ink composition that reduces the environmental load, has an excellent balance of blocking resistance, adhesion, and laminate strength, and suppresses the ink layer from falling off after boiling or retort treatment. [Means for solving the problem]

[0006] Therefore, the present inventors have conducted extensive research to solve the above problems, and have found that the above problems can be solved by using a specific urethane resin (I) having structural units derived from polydiene polyol and / or hydrogenated polydiene polyol, and have completed the present invention described in any of the following items (1) to (13).

[0007] [1] A liquid ink composition comprising a urethane resin component and an organic solvent, wherein the urethane resin component comprises a urethane resin (I) produced from reaction raw materials (I) including a polyol component containing a polydiene polyol and / or a hydrogenated polydiene polyol, a polyol component containing a polyester polyol, and a polyisocyanate compound (I).

[0008] [2] The liquid ink composition according to [1], wherein the urethane bond concentration of the entire urethane resin components is 0.85 mmol / g or more, and the proportion of the urethane resin (I) is the highest among the resin components contained in the liquid ink composition.

[0009] [3] The liquid ink composition according to [1] or [2], characterized in that it contains 1 to 20 mass% of structural units derived from the polydiene polyol and / or structural units derived from the hydrogenated polydiene polyol relative to 100 mass% of the urethane resin (I).

[0010] [4] The liquid ink composition according to any one of the above [1] to [3], characterized in that the mass ratio of the polydiene polyol and / or hydrogenated polydiene polyol to the polyester polyol in the polyol component is 5:95 to 90:10.

[0011] [5] The liquid ink composition according to any one of the above [1] to [4], wherein the polyol component further contains a polyether polyol.

[0012] [6] The liquid ink composition according to any one of the above [1] to [5], further comprising at least one resin selected from the group consisting of a urethane resin (II) other than the urethane resin (I), a polyvinyl butyral resin, a maleic acid resin, a cellulose resin, a polyester resin, an acrylic resin, and a polyamide resin.

[0013] [7] The liquid ink composition according to any one of the above [1] to [6], wherein the urethane resin (I) has an amine value of 0 to 10.0 mgKOH / g.

[0014] [8] The liquid ink composition according to [7] above, wherein the urethane bond concentration of the urethane resin (I) is 0.86 mmol / g or more.

[0015] [9] The liquid ink composition according to [7] or [8] above, characterized in that the chlorine content in the resin component contained in the liquid ink composition is 5 mass % or less.

[0016]

[10] A printed matter obtained by printing the liquid ink composition according to any one of [1] to [9] above onto a substrate.

[0017]

[11] A laminate or package comprising the printed matter described in

[10] above. [Effects of the Invention]

[0018] According to the present disclosure, it is possible to provide a liquid ink composition that reduces the environmental load, has an excellent balance of blocking resistance, adhesion, and laminate strength, and suppresses the detachment of the ink layer after boiling or retort treatment. DETAILED DESCRIPTION OF THE INVENTION

[0019] Hereinafter, an embodiment of the present invention (hereinafter referred to as "the present embodiment") will be described in detail, but the present invention is not limited to the following description and can be practiced with various modifications within the scope of the gist. Furthermore, in the present embodiment, A (numerical value) to B (numerical value) means A or more and B or less.

[0020] [Definition] In this specification, the term "liquid ink composition" refers to a liquid printing ink, such as gravure ink or flexographic ink, that is applied to a printing method using a printing plate, and is preferably gravure ink or flexographic ink. In addition, all "ink" used in the following description refers to "printing ink." In this specification, all "parts" refer to "parts by mass," "total amount of ink" refers to the total amount of ink including all volatile components such as solvents, and "(ink or resin) solids (total amount)" refers to the total amount of only non-volatile components, excluding volatile components. In this specification, the term "reactive raw materials" refers to compounds used to obtain a target compound through a chemical reaction such as synthesis or decomposition, and which partially constitute the chemical structure of the target compound. Catalysts and solvents are excluded. In particular, the term "reactive raw materials" refers to precursors for obtaining the target urethane resin (I) or urethane resin (II) through a chemical reaction, including various polyisocyanate compounds (I), various polyols, and amine compounds added as needed (e.g., amine compounds such as chain extenders, described below). For example, the term "content of polyisocyanate compounds (I) relative to 100% by mass of reactive raw materials (I)" refers to the ratio of the polyisocyanate compounds (I) and all polyol components (the total amount of the first polyol component and the second polyol component) to 100% by mass. As used herein, the term "structural unit" refers to a (repeating) unit of a chemical structure formed during a reaction or polymerization; in other words, it refers to a partial structure, other than the structure of the chemical bonds involved in the reaction or polymerization, in a product compound formed through a reaction or polymerization, and is a so-called residue. In this specification, the term "urethane resin component" is a general term for resins having a urethane bond, and unless otherwise specified, refers to a urethane resin that forms a coating film among the non-volatile components in a liquid ink composition. The "urethane resin component" contains at least a urethane resin (I) and may further contain a urethane resin (II) other than the urethane resin (I), as necessary. The urethane resin (II) other than the urethane resin (I) has a chemical structure different from that of the urethane resin (I). In this specification, the term "binder resin" refers to a binder resin contained in an ink or ink composition. The binder resin may be dissolved in a solvent or may be in an emulsion state. Therefore, the binder resin must contain a urethane resin component, and may contain binder resins other than the urethane resin component (hereinafter referred to as "other resins") as necessary.

[0021] The "aromatic group" in this specification may be substituted or unsubstituted. The "aromatic group" preferably has an aromatic ring having 3 to 30 carbon atoms, not including the carbon atoms of the substituent, and more preferably has an aromatic ring having 4 to 26 carbon atoms. The "aromatic group" in this specification may have a hydrogen atom of the aromatic ring substituted with a substituent, for example, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or a halogen atom. The "aromatic group" also includes heteroaromatic groups, and may be substituted with -O-, -S-, or -N= so that -CH2- or -CH= in the "aromatic group" are not adjacent to each other. Examples of the aromatic ring include a monocyclic aromatic ring, a condensed aromatic ring, and an agglomerated aromatic ring. Examples of the monocyclic aromatic ring include benzene, furan, pyrrole, thiophene, imidazole, pyrazole, oxazole, isoxazole, thiazole, isothiazole, pyridine, pyrimidine, pyridazine, pyrazine, and triazine. Examples of the fused aromatic ring include naphthalene, anthracene, phenalene, phenanthrene, quinoline, isoquinoline, quinazoline, phthalazine, pteridine, coumarin, indole, benzimidazole, benzofuran, and acridine. Examples of the ring-assembly aromatic ring include biphenyl, binaphthalene, bipyridine, bithiophene, phenylpyridine, phenylthiophene, terphenyl, diphenylthiophene, and quaterphenyl. In addition, a hydrogen atom of the aromatic ring in the aromatic group may be substituted with, for example, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or a halogen atom. Note that a divalent aromatic group refers to a group obtained by removing two hydrogen atoms from an "aromatic group." As used herein, examples of the "aryl group" include a phenyl group, a naphthyl group, a phenalenyl group, a phenanthrenyl group, an anthryl group, an azulenyl group, an indenyl group, an indanyl group, and a tetralinyl group. Furthermore, the "aryl group" may have a hydrogen atom in the aromatic ring substituted with, for example, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, or a halogen atom. Examples of the "arylene group" include a divalent group obtained by removing any one hydrogen atom from the aforementioned "aryl group." As used herein, examples of the "aralkyl group" include a benzyl group, a diphenylmethyl group, a biphenyl group, and a naphthylmethyl group. A hydrogen atom on the aromatic ring in the aralkyl group may be substituted with, for example, an alkyl group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, or a halogen atom. Examples of the "aralkylene group" include a divalent group obtained by removing any one hydrogen atom from the aforementioned "aralkyl group." Examples of the "aryloxy group" in this specification include a phenoxy group, a naphthyloxy group, an anthryloxy group, a phenanthryloxy group, a pyrenyloxy group, etc. A hydrogen atom on the aromatic ring in the aryloxy group may be substituted with, for example, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, or a halogen atom. As used herein, the term "arylthio group" includes arylthio groups such as a phenylthio group, a naphthylthio group, an anthrylthio group, a phenanthrylthio group, and a pyrenylthio group. A hydrogen atom on the aromatic ring in the arylthio group may be substituted with, for example, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, or a halogen atom. The "alkyl group" in this specification may be linear, branched, or cyclic, and examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, a tert-pentyl group, a neopentyl group, a 1,2-dimethylpropyl group, an n-hexyl group, an isohexyl group, a (n-)heptyl group, a (n-)octyl group, a (n-)nonyl group, a (n-)decyl group, a (n-)undecyl group, a (n-)dodecyl group, or a cycloalkyl group described below. The "alkylene group" refers to a group in which one hydrogen atom has been removed from any position of the above-mentioned alkyl group, and examples thereof include a methylene group, an ethylene group, a propylene group, an isopropylene group, an n-butylene group, an isobutylene group, a sec-butylene group, a tert-butylene group, an n-pentylene group, an isopentylene group, a tert-pentylene group, a neopentylene group, a 1,2-dimethylpropylene group, an n-hexylene group, an isohexylene group, a (n-)heptylene group, a (n-)octylene group, a (n-)nonylene group, a (n-)decylene group, a (n-)undecylene group, a (n-)dodecylene group, and a cycloalkylene group described below. As used herein, "cycloalkyl groups" include cyclopropyl groups, cyclobutyl groups, cyclopentyl groups, cyclohexyl groups, cycloheptyl groups, cyclooctyl groups, cyclononyl groups, cyclodecyl groups, norbornyl groups, and adamantyl groups. "Cycloalkylene groups" include groups in which one hydrogen atom has been removed from any position of the above-mentioned cycloalkyl groups, such as cyclopropylene groups, cyclobutylene groups, cyclopentylene groups, cyclohexylene groups, cycloheptylene groups, cyclooctylene groups, cyclononylene groups, cyclodecylene groups, norbornyl groups, and adamantyl groups. The hydrogen atom of the cycloalkyl group or the cyclic group in the cycloalkylene group may be substituted with, for example, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, or a halogen atom. As used herein, the term "alkylthio group" includes a methylthio group, an ethylthio group, a propylthio group, a butylthio group, an octylthio group, and a 2-ethylhexylthio group. As used herein, the term "alkenyl group" includes an ethynyl group, a 1-propynyl group, a 2-propynyl group, a 2-butynyl group, a pentynyl group, a hexynyl group, a vinyl group, an allyl group, an isopropenyl group, etc. An "alkenylene group" is a group obtained by removing one hydrogen atom from the above-mentioned alkenyl group. As used herein, the term "alkoxy group" includes, for example, a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, a 2-ethylhexyloxy group, an octyloxy group, a nonyloxy group, etc. The term "alkylene oxide group" includes, for example, a divalent group such as an ethylene oxide group, a propylene oxide group, a butylene oxide group, a pentylene oxide group, etc. As used herein, the term "halogen atom" includes, for example, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, and the like. An "organic group" is a group having 1 to 20 carbon atoms. Therefore, the above-mentioned "aromatic group," "aryl group," "arylene group," "aralkyl group," "aralkylene group," "aryloxy group," "arylthio group," "alkyl group," "cycloalkyl group," "alkylthio group," "alkenyl group," "alkenylene group," "alkoxy group," and "alkylene oxide group" are included in the "organic group." In addition, any hydrogen atom can be removed depending on the valence. For example, a trivalent alkyl group is a group obtained by removing two arbitrary hydrogen atoms from an alkyl group.

[0022] [Liquid ink composition (hereinafter also simply referred to as ink composition)] The liquid ink composition of the present disclosure contains a urethane resin component and an organic solvent. The urethane resin component contains a urethane resin (I) produced from reaction raw materials (I) including a first polyol component containing a polydiene polyol and / or a hydrogenated polydiene polyol, a second polyol component containing a polyester polyol, and a polyisocyanate compound (I). This makes it possible to provide a liquid ink composition that reduces the environmental load, has an excellent balance of blocking resistance, adhesion and laminate strength, and inhibits the ink layer from falling off after boiling or retort treatment. The liquid ink composition of this embodiment, morphologically classified, contains a urethane resin component, an organic solvent, and, optionally, one or more components selected from the group consisting of pigments and additives. The urethane resin component functions as a binder resin. The urethane resin component contains a urethane resin (I) as an essential component. The urethane resin (I) is a resin whose reactive raw materials (I) are a first polyol component containing a polydiene polyol and / or a hydrogenated polydiene polyol, a second polyol component containing a polyester polyol, and a polyisocyanate compound (I). For ease of explanation, "polyester polyol," "polyether polyol," and "polyisocyanate compound (I)," which may be included as components of the reaction raw material (I) of the essential urethane resin (I), are referred to as "polyester polyol (I)," "polyether polyol (I)," and "polyisocyanate compound (I)." Similarly, "polyester polyol," "polyether polyol," and "polyisocyanate compound (I)," which may be included as components of the reaction raw material (II) of the optional urethane resin (II), are referred to as "polyester polyol (II)," "polyether polyol (II)," and "polyisocyanate compound (I)(II)." Furthermore, the "first polyol component containing a polydiene polyol and / or a hydrogenated polydiene polyol" may be a first polyol component containing one or more selected from the group consisting of polydiene polyols and hydrogenated polydiene polyols.

[0023] In the liquid ink composition of this embodiment, the content of the urethane resin component (solid content) is preferably 5 to 95 mass % of the total solid content of the liquid ink composition, more preferably 15 to 80 mass %, even more preferably 20 to 60 mass %, and even more preferably 30 to 57 mass %. By making the content of the urethane resin component (solid content) 30 mass % or more, better extrusion lamination strength is achieved when printed on OPP film.

[0024] In the liquid ink composition of this embodiment, the total binder resin (solid content) content is preferably 5 to 95% by mass, more preferably 15 to 80% by mass, and even more preferably 20 to 65% by mass, based on the total solid content of the liquid ink composition. By setting the binder resin (solid content) content to 20% by mass or more, good pigment dispersion stability and coating film properties are exhibited. On the other hand, by setting the binder resin (solid content) content to less than 20% by mass, good print color density is exhibited. The binder resin is a general term for not only the urethane resin component but also the binding resin contained in the ink or ink composition.

[0025] In the liquid ink composition of this embodiment, the proportion of the urethane resin component (solid content) relative to the total solid content of the binder resin (solid content) is preferably 30 to 100 mass %, more preferably 40 to 90 mass %, and even more preferably 50 to 80 mass %. By making the proportion of the urethane resin component (solid content) 50 mass % or more, better extrusion lamination strength is achieved when printed on OPP film.

[0026] The liquid ink composition of this embodiment may further contain a urethane resin (II) other than the urethane resin (I), if necessary, which allows the formation of an ink layer with an excellent balance of blocking resistance, adhesion, and laminate strength, and further suppresses the ink layer from falling off after boiling or retort treatment.

[0027] The liquid ink composition of this embodiment may further contain, as necessary, a binder resin (other resin) other than the urethane resin component. More specifically, the liquid ink composition may further contain, as a binder resin, at least one resin selected from the group consisting of a urethane resin (II) other than the urethane resin (I), a polyvinyl butyral resin, a maleic acid resin, a cellulose resin, a polyester resin, an acrylic resin, and a polyamide resin. This makes it possible to provide excellent blocking resistance, adhesion, and laminate strength, and to further suppress the ink layer from falling off after boiling or retort treatment. The liquid ink composition of this embodiment may further contain, as necessary, one or more types selected from the group consisting of pigments and additives.

[0028] The essential components of the liquid ink composition of the present disclosure, namely, the urethane resin component, the urethane resin (I), and the organic solvent, as well as the optional components, namely, the urethane resin (II), the binder resin other than the urethane resin component, the pigment, and the additives, will be described in detail below.

[0029] (urethane resin component) The liquid ink composition of the present disclosure contains a urethane resin component, which is a resin having a urethane bond and a number average molecular weight of 1,000 or more, and the urethane resin component essentially contains urethane resin (I). The urethane resin component functions as a binder resin to improve the adhesion of the ink, and can also function as a pigment dispersing resin. The number average molecular weight of the entire urethane resin component of this embodiment is preferably in the range of 7,000 to 100,000. The urethane resin component may contain a urethane resin (II) other than the urethane resin (I). By using a predetermined urethane resin (I) in combination with a urethane resin (II) other than the urethane resin (I), an ink layer having an excellent balance of blocking resistance, adhesion, and laminate strength can be formed, and peeling of the ink layer after boiling or retort treatment can be further suppressed.

[0030] <Urethane bond concentration> In this embodiment, the lower limit of the urethane bond concentration of the entire urethane resin component is preferably 0.85 mmol / g or more. When the lower limit of the urethane bond concentration is 0.85 mmol / g or more, the extrusion laminate strength tends to be further improved. The lower limit of the urethane bond concentration is preferably 0.89 mmol / g or more, 0.94 mmol / g or more, 0.97 mmol / g or more, 1.05 mmol / g or more, 1.10 mmol / g or more, 1.15 mmol / g or more, or 1.20 mmol / g or more. Meanwhile, the upper limit of the urethane bond concentration of the entire urethane resin component is preferably 5.0 mmol / g or less, more preferably 4.0 mmol / g or less, even more preferably 3.0 mmol / g or less, still more preferably 2.0 mmol / g or less, even more preferably 1.7 mmol / g or less, and particularly preferably 1.6 mmol / g or less. The upper and lower limits can be combined in any manner. A urethane bond concentration of 0.85 mmol / g or more is preferable from the viewpoint of extrusion lamination strength when printed on an OPP film, while a urethane bond concentration of 2.0 mmol / g or less is preferable from the viewpoints of urethane resin raw material cost, ink viscosity, and flexibility of the ink coating on the film (adaptability to film deformation).

[0031] The urethane bond concentration in this specification is calculated by the following formula (a): More specifically, the calculation method for the urethane bond concentration will be explained below using as an example a case where the urethane resin component of this embodiment includes urethane resin (I), urethane resin (II), urethane resin (k) (k is a natural number), that is, a case where the urethane resin component is composed of k types of urethane resins. In this case, the total number of polyols constituting all polyol components (the sum of the first polyol component and the second polyol component) contained in the reactive raw material (I) of the urethane resin (I) is v (v is a natural number), the total number of polyols constituting all polyol components contained in the reactive raw material (II) of the urethane resin (II) is w (w is a natural number), and... the total number of polyols constituting all polyol components contained in the reactive raw material (k) of the urethane resin (k) is x (x is a natural number). [Number 1] Formula (a): Urethane bond concentration = [{(W i1 ×OH i1 +W i2 ×OH i2 +···W iv ×OH iv )+(W ii1 ×OH ii1 +W ii2 ×OH ii2 +···W iiw ×OH iiw )+···+(W k1 ×OH k1 +W k2 ×OH k2 +···W kx ×OH kx )}×1000] / (56100×S) "In the above formula (a); W i1 : Mass of the first polyol component contained in the reaction raw material (I) of the urethane resin (I) OH i1 : hydroxyl value of the first polyol component contained in the reaction raw material (I) of the urethane resin (I) W i2 : the mass of the second polyol component contained in the reaction raw material (I) OH i2 : The hydroxyl value of the second polyol component contained in the reaction raw material (I) W iv : the mass of the vth polyol component contained in the reaction raw material (I) OH iv : the hydroxyl value of the vth polyol component contained in the reaction raw material (I) W ii1: Mass of the first polyol component contained in the reaction raw material (II) of the urethane resin (II) OH ii1 : hydroxyl value of the first polyol component contained in the reaction raw material (II) of the urethane resin (II) W ii2 : the mass of the second polyol component contained in the reaction raw material (II) OH ii2 : The hydroxyl value of the second polyol component contained in the reaction raw material (II) W iiw : the mass of the wth polyol component contained in the reaction raw material (II) OH iiw : the hydroxyl value of the wth polyol component contained in the reaction raw material (II) W k1 : Mass of the first polyol component contained in the reaction raw material (k) of the urethane resin (k) OH k1 : hydroxyl value of the first polyol component contained in the reaction raw material (k) of the urethane resin (k) W k2 : the mass of the second polyol component contained in the reaction raw material (k) OH k2 : The hydroxyl value of the second polyol component contained in the reaction raw material (k) W kx : mass of the xth polyol component contained in the reaction raw material (k) OH kx : the hydroxyl value of the xth polyol component contained in the reaction raw material (k) S: Mass of all solids in the urethane resin component In the above formula (a), when the urethane resin component is composed of one or more urethane resins and one or more polyol components are used as the respective reaction raw materials for the one or more urethane resins, the calculation is performed using polyol component (i1) to polyol component (iv), respectively polyol component (ii1) to polyol component (iiw), ... polyol component (k1) to polyol component (kx). That is, in the above formula (a), the urethane bond concentration is calculated by multiplying the sum of the products of the masses of each polyol component in all the polyol components that make up the urethane resin component by the hydroxyl value of that polyol component by 1,000, as the numerator, and by multiplying 56,100 by the mass of the total solids of the urethane resin component as the denominator. The urethane bond concentration in this specification can be measured as follows. A urethane resin (component) is obtained by solvent extraction from the liquid ink composition of this embodiment. The urethane bond concentration can then be calculated by subjecting a sample of the solvent-extracted urethane resin to the following two analytical methods. Analysis method 1: NMR analysis is performed, and the urethane bond concentration is calculated from the integral value of the peak derived from the urethane bond. Analysis method 2: By performing NMR, GPC, and mass spectrometry, information on the molecular weight, chemical structure, and content ratio of the polyisocyanate compound (I), polyol component, amine compound, etc. that make up the urethane resin is obtained. The urethane bond concentration is calculated from this composition information. The urethane resin component of this embodiment as a whole preferably contains a polyether polyol as a reaction raw material. Specifically, either the urethane resin (I) or the urethane resin (II) may contain a polyether polyol as a reaction raw material, or both the urethane resin (I) and the urethane resin (II) may contain a polyether polyol as a reaction raw material.

[0032] (Urethane resin (I)) The liquid ink composition of this embodiment contains, as essential components, a first polyol component containing a polydiene polyol and / or a hydrogenated polydiene polyol, a second polyol component containing a polyester polyol (I), and a urethane resin (I) having a polyisocyanate compound (I) as reaction raw materials (1). In other words, the urethane resin (I) in this embodiment has a structure in which a structural unit derived from a polydiene polyol and / or a hydrogenated polydiene polyol (= a polydiene polyol and / or a hydrogenated polydiene polyol residue), a structural unit derived from a polyester polyol (I) (= a polyester polyol (I) residue), and a structural unit derived from a polyisocyanate compound (I) (= a polyisocyanate compound (I) residue) are chemically bonded directly or indirectly. The reactive raw material (I) may further contain a polyether polyol (I) and / or an aromatic polyol described below. That is, the liquid ink composition of this embodiment may contain a polydiene polyol and / or a hydrogenated polydiene polyol, a polyester polyol, a polyether polyol (I) and / or an aromatic polyol described below, and a polyisocyanate compound (I). In other words, one preferred urethane resin (I) of this embodiment has a structure in which structural units derived from a polydiene polyol and / or a hydrogenated polydiene polyol, structural units derived from a polyester polyol (I), structural units derived from a polyether polyol (I), structural units derived from an aromatic polyol described below, and structural units derived from a polyisocyanate compound (I) are chemically bonded directly or indirectly. The urethane resin (I) is not particularly limited as long as it is a resin having a urethane bond obtained by reacting a polyol with an isocyanate. The urethane resin (I) not only functions as a binder resin to improve ink adhesion, but also as a pigment dispersing resin. Furthermore, the urethane resin (I) is preferably a urethane-urea resin (i.e., preferably has a urethane bond and a urea bond).

[0033] In the liquid ink composition of this embodiment, the content of urethane resin (I) is preferably 30 to 100% by mass, more preferably 40 to 91% by mass, and even more preferably 50 to 81% by mass, based on the total resin solids content of the liquid ink composition. By setting the content of urethane resin (I) to 30% by mass or more, it is possible to freely adjust the amount of urethane resin (II), which is an optional component, to achieve the desired effect while maintaining pigment dispersibility. On the other hand, by setting the content of urethane resin (I) to 100% by mass or less, it is easier to reflect the properties of urethane resin (I) throughout the entire liquid ink composition. In the liquid ink composition of this embodiment, the content of the urethane resin (I) is preferably 20 to 100% by mass, more preferably 35 to 96% by mass, and even more preferably 45 to 91% by mass, based on the total resin solids content of the urethane resin component. By setting the content of the urethane resin (I) to 20% by mass or more, better extrusion lamination strength is achieved when printed on OPP film. On the other hand, by setting the content of the urethane resin (I) to 100% by mass or less, the properties of the urethane resin (I) can be more easily reflected in the entire liquid ink composition. In the liquid ink composition of this embodiment, it is preferred that the urethane resin (I) accounts for the largest proportion of the resin components contained in the liquid ink composition. The resin component contained in the liquid ink composition refers to a resin that forms a coating film, and may be a so-called binder resin. If the urethane resin (I) accounts for the highest proportion of the resins that form the coating film, the properties of the urethane resin (I) can be more easily reflected in the entire liquid ink composition.

[0034] The amine value of the urethane resin (I) used in the liquid ink composition of this embodiment is preferably 10.0 mgKOH / g or less. When the amine value is 10.0 mgKOH / g or less, blocking resistance tends to be better. From the viewpoint of maintaining blocking resistance, adhesiveness, and laminate strength, the amine value is more preferably in the range of 0 to 10.0 mgKOH / g, and even more preferably in the range of 0.1 to 2.0 mgKOH / g. The amine value is calculated by the method shown in the Examples section below. The lower limit of the urethane bond concentration of the urethane resin (I) of this embodiment is preferably 0.86 mmol / g or more. When the lower limit of the urethane bond concentration is 0.86 mmol / g or more, extrusion laminate strength tends to be further improved. The lower limit of the urethane bond concentration is preferably 0.89 mmol / g or more, 0.94 mmol / g or more, 0.97 mmol / g or more, 1.05 mmol / g or more, 1.10 mmol / g or more, 1.15 mmol / g or more, or 1.20 mmol / g or more. Meanwhile, the upper limit of the urethane bond concentration of the urethane resin (I) is preferably 5.0 mmol / g or less, more preferably 4.0 mmol / g or less, even more preferably 3.0 mmol / g or less, still more preferably 2.0 mmol / g or less, even more preferably 1.7 mmol / g or less, and particularly preferably 1.6 mmol / g or less. The upper and lower limits can be combined in any manner. The urethane bond concentration of the urethane resin (I) can be calculated by the above formula (1).

[0035] Below, we will explain the constituent components of the reaction raw materials (I) of the urethane resin (I) (polydiene polyol and / or hydrogenated polydiene polyol, polyester polyol (I), polyisocyanate compound (I), and optionally blended polyether polyol (I) and aromatic polyol), and then we will explain preferred embodiments of the urethane resin (I).

[0036] <First polyol component> The reaction raw material (I) for the urethane resin (I) of this embodiment contains a polydiene polyol and / or a hydrogenated polydiene polyol as a first polyol component. The first polyol component is substantially composed of a polydiene polyol and a hydrogenated polydiene polyol. In this specification, "component A is substantially composed of B" means that the content of B relative to the entire component A (100% by mass) is 97% by mass or more, preferably 98.6% by mass or more. In the reaction raw material (I) of this embodiment, the content of the first polyol component relative to the entire reaction raw material (I) (100% by mass) is preferably 1% by mass or more and 30% by mass or less, more preferably 2.5% by mass or more and 20% by mass or less, and even more preferably 4% by mass or more and 10% by mass or less. In the reaction raw material (I) of the present embodiment, the mixing ratio (by mass) of the first polyol component to the second polyol component (first polyol component / second polyol component) is preferably in the range of 1 / 99 to 40 / 60, more preferably in the range of 3 / 97 to 25 / 75, and even more preferably in the range of 5 / 95 to 15 / 85. The above-mentioned range of mixing ratio is preferable from the viewpoint of the balance between laminate strength and blocking resistance.

[0037] <Polydiene polyol and / or hydrogenated polydiene polyol> The polydiene polyol of this embodiment refers to a compound having one or more diene structures and hydroxyl groups and a number average molecular weight of 200 to 100,000. The diene structure may be a conjugated diene or a non-conjugated diene, and examples thereof include alkadienes having 4 to 10 carbon atoms (conjugated dienes (butadiene, isoprene, butadiene-isoprene, etc.), non-conjugated dienes (pentadiene, hexadiene, octadiene, etc.)), and cyclic dienes having 5 to 10 carbon atoms (cyclopentadiene, dicyclopentadiene, ethylidene norbornene). Among these, the polydiene polyol of the present embodiment preferably has a conjugated diene structure or a non-conjugated diene structure, more preferably has a polybutadiene structural unit, a polyisoprene structural unit, or a poly(butadiene-isoprene) structural unit, and further preferably is a polybutadiene polyol or a polyisoprene polyol. The hydrogenated polydiene polyol of this embodiment refers to a compound obtained by hydrogenating the unsaturated double bonds in the polydiene polyol (hereinafter also simply referred to as hydrogenation). Therefore, the hydrogenated polydiene polyol is obtained by a hydrogenation reaction in which the polydiene polyol is hydrogenated in the presence of a hydrogenation catalyst. Preferred hydrogenated polydiene polyols for this embodiment include hydrogenated polybutadiene polyols and hydrogenated polyisoprene polyols. The hydrogenation catalyst is not particularly limited, and examples thereof include known supported heterogeneous hydrogenation catalysts (catalysts in which a metal such as Ni, Pt, Pd, or Ru is supported on carbon, silica, alumina, diatomaceous earth, or the like), Ziegler-type hydrogenation catalysts (catalysts using a transition metal salt such as an organic acid salt of Ni, Co, Fe, Cr, or the like or an acetylacetone salt, and a reducing agent such as organoaluminum), and organometallic complexes (organometallic compounds containing a metal such as Ti, Ru, Rh, or Zr).Specific hydrogenation catalysts that can be used include the hydrogenation catalysts described in JP-B Nos. 42-8704, 43-6636, 63-4841, 1-37970, 1-53851, and 2-9041. The hydrogenation reaction is preferably carried out at a temperature ranging from 0 to 200°C, more preferably from 30 to 150°C. The hydrogen pressure applied in the hydrogenation reaction is preferably from 0.1 to 15 MPa, more preferably from 0.2 to 10 MPa, and even more preferably from 0.3 to 5 MPa. The reaction time for the hydrogenation reaction is, for example, preferably from 3 minutes to 10 hours, more preferably from 10 minutes to 5 hours. The hydrogenation reaction can be carried out as a batch process, a continuous process, or a combination thereof.

[0038] In the hydrogenated polydiene polyol of this embodiment, the hydrogenation rate of the unsaturated double bonds based on the diene structure can be selected arbitrarily depending on the purpose. For example, the hydrogenation rate of the unsaturated double bonds based on the diene structure in the hydrogenated polydiene polyol is preferably 10 mol% or more, more preferably 50 mol% or more, and even more preferably 75 mol% or more. Furthermore, for example, the hydrogenated polydiene polyol may be only partially hydrogenated. The hydrogenation rate of the hydrogenated polydiene polyol may be 10 mol% or more but less than 100 mol%, 50 mol% or more but less than 90 mol%, or 50 mol% or more but less than 80 mol%. The above-mentioned "hydrogenation rate" refers to the proportion of hydrogenated vinyl bonds among vinyl bonds in non-conjugated dienes or conjugated dienes incorporated in a diene form (for example, a polydiene polyol) before hydrogenation.

[0039] The hydrogenation rate of the hydrogenated polydiene polyol can be adjusted by changing the amount of hydrogen added to the polydiene polyol and the hydrogenation catalyst used. 1 H-NMR and 13 It can be calculated using a nuclear magnetic resonance (NMR) spectrometer such as C-NMR.

[0040] <<Properties of Polydiene Polyol and / or Hydrogenated Polydiene Polyol>> In the present embodiment, the content of 1,2-vinyl moieties in the polydiene polyol is, for example, 10 to 100% by mass, and preferably 20 to 90% by mass, from the viewpoint of crosslinking reactivity. The unsaturated double bond content (%) is calculated by nuclear magnetic resonance spectroscopy (NMR) in the same manner as the hydrogenation rate of the hydrogenated polydiene polyol.

[0041] The number average molecular weight of the polydiene polyol and / or hydrogenated polydiene polyol of this embodiment is not particularly limited, but is, for example, 300 to 10,000, preferably 600 to 5,000, and more preferably 700 to 5,000. The number average molecular weight of the polybutadiene polyol or hydrogenated polybutadiene polyol of this embodiment is preferably 500 to 10,000, and more preferably 800 to 4,000. When the number average molecular weight is within the above range, the polybutadiene polyol and / or hydrogenated polybutadiene polyol becomes liquid and is easy to handle. The number average molecular weight of the polyisoprene polyol or hydrogenated polyisoprene polyol of the present embodiment is not particularly limited, but is preferably 500 to 5000. When the number average molecular weight is within the above range, the polyisoprene polyol or hydrogenated polyisoprene polyol becomes liquid and is easy to handle. The number average molecular weight can be evaluated as a polystyrene-equivalent molecular weight using gel permeation chromatography (GPC). In this specification, the number average and weight average molecular weights are values ​​measured by gel permeation chromatography (GPC) under the following conditions. Measurement equipment: High-speed GPC equipment (Tosoh Corporation "HLC-8220GPC") Column: The following columns manufactured by Tosoh Corporation were connected in series and used. "TSKgel G5000" (7.8mm I.D. x 30cm) x 1 "TSKgel G4000" (7.8mm I.D. x 30cm) x 1 "TSKgel G3000" (7.8mm I.D. x 30cm) x 1 "TSKgel G2000" (7.8mmI.D. x 30cm) x 1 Detector: RI (differential refractometer) Column temperature: 40℃ Eluent: tetrahydrofuran (THF) Flow rate: 1.0mL / min Injection volume: 100 μL (sample concentration 0.4% by mass in tetrahydrofuran solution) Standard sample: A calibration curve was prepared using the following standard polystyrene. [Standard polystyrene] Tosoh Corporation's "TSKgel Standard Polystyrene A-500" Tosoh Corporation's "TSKgel Standard Polystyrene A-1000" Tosoh Corporation's "TSKgel Standard Polystyrene A-2500" Tosoh Corporation's "TSKgel Standard Polystyrene A-5000" "TSKgel Standard Polystyrene F-1" manufactured by Tosoh Corporation Tosoh Corporation's "TSKgel Standard Polystyrene F-2" Tosoh Corporation's "TSKgel Standard Polystyrene F-4" Tosoh Corporation's "TSKgel Standard Polystyrene F-10" Tosoh Corporation's "TSKgel Standard Polystyrene F-20" Tosoh Corporation's "TSKgel Standard Polystyrene F-40" Tosoh Corporation's "TSKgel Standard Polystyrene F-80" Tosoh Corporation's "TSKgel Standard Polystyrene F-128" Tosoh Corporation's "TSKgel Standard Polystyrene F-288" Tosoh Corporation's "TSKgel Standard Polystyrene F-550"

[0042] The hydroxyl value of the polybutadiene polyol and / or hydrogenated polybutadiene polyol of this embodiment may be preferably 10 to 500 mgKOH / g, more preferably 25 to 250 mgKOH / g, and even more preferably 50 to 150 mgKOH / g. When the hydroxyl value of the polybutadiene polyol and / or hydrogenated polybutadiene polyol is within the above range, the urethane bond concentration can be easily controlled to a predetermined value or higher, and therefore the laminate strength can be further improved.

[0043] In the urethane resin (I) (resin solid content) of the present embodiment, the content of the polybutadiene polyol-derived structural units and / or hydrogenated polybutadiene polyol-derived structural units (= so-called polybutadiene polyol residues and / or hydrogenated polybutadiene polyol residues) in the urethane resin (I) is preferably in the range of 1 to 20 mass %, more preferably 2 to 15 mass %, and even more preferably 4 to 10 mass %, based on the entire urethane resin (I) (resin solid content). It is preferable from the viewpoint of the balance between laminate strength and blocking resistance that the polybutadiene polyol and / or hydrogenated polybutadiene polyol-derived structural units contained in the urethane resin (I) (resin solid content) are in the above range.

[0044] The polydiene polyol and / or hydrogenated polydiene polyol of the present embodiment may be a commercially available product, or may be synthesized by a known method. Examples of the commercially available polydiene polyols and / or hydrogenated polydiene polyols include Poly bd R-15HT (number average molecular weight 1200), R-45HT (number average molecular weight 2800), Poly ip (number average molecular weight 2500) (all manufactured by Idemitsu Kosan Co., Ltd.), NISSO-PB G-1000 (number average molecular weight 1400), G-2000 (number average molecular weight 1900), G-3000 (number average molecular weight 3000) (all manufactured by Nippon Soda Co., Ltd.), Krasol LBH2000 (number average molecular weight 2000), LBH3000 (number average molecular weight 3000), LBH2040 (number average molecular weight 2249), LBH5000 (number average molecular weight 5000), LBH10000 (number average molecular weight 10000), Krasol Available polymers include LBH-P2000 (number average molecular weight 2000), LBH-P3000 (number average molecular weight 3000), LBH-P5000 (number average molecular weight 5000), LBH-P10000 (number average molecular weight 10000), Poly bd R45HTLO (number average molecular weight 2800), R45M (number average molecular weight 2800), and R20LM (number average molecular weight 1200) (all manufactured by Cray Valley), Polyvest HT (number average molecular weight 2900) (manufactured by Evonik), and Hydroxyl-Terminated-Polymer-Butadiene (manufactured by Zibo). The polydiene polyols and / or hydrogenated polydiene polyols may be used alone or in combination of two or more.

[0045] In the reaction raw material (I) of the present embodiment, the mass ratio of the polydiene polyol and / or hydrogenated polydiene polyol in the first polyol component to the polyester polyol (I) in the second polyol component is preferably 5:95 to 90:10. When the mixing ratio of the polydiene polyol and / or hydrogenated polydiene polyol to the polyester polyol (I) in the reaction raw material (I) is within the above range, the balance of blocking resistance, adhesion, and laminate strength is excellent, and the effect of further suppressing the detachment of the ink layer after boiling or retort treatment is achieved.

[0046] <Polyisocyanate Compounds (I)> The polyisocyanate compound (I) used in the urethane resin (I) of this embodiment can be any of various known polyisocyanate compounds (I) commonly used in the production of general polyurethane resins, and among these, a polyisocyanate compound (I) having two or more isocyanate groups is preferred, and a polyisocyanate compound (I) is more preferred. Preferred polyisocyanate compounds (I) of this embodiment include aromatic diisocyanates, aliphatic diisocyanates, and alicyclic diisocyanates. The polyisocyanate compound (I) is a compound represented by the following general formula (1): [ka] (In the above general formula (1), L 5 and L 6 each independently represents a single bond or an alkylene group having 1 to 5 carbon atoms; M 2 represents a divalent organic group. It is preferable that the formula be represented by the following formula: In the above general formula (1), L 5 is preferably a single bond or an alkylene group having 1 to 3 carbon atoms. In the above general formula (1), L 6 is preferably a single bond or an alkylene group having 1 to 3 carbon atoms. In the general formula (1), the divalent organic group preferably has 1 to 20 carbon atoms, more preferably 2 to 18 carbon atoms, and even more preferably 3 to 17 carbon atoms. The term "organic group" refers to a group having 1 or more carbon atoms, and is preferably a hydrocarbon group having 1 to 20 carbon atoms. The divalent organic group is preferably an alkylene group having 1 to 20 carbon atoms, an alkenylene group having 1 to 20 carbon atoms, an alkyleneoxy group having 1 to 20 carbon atoms, or an arylene group having 6 to 18 carbon atoms. In addition, one or two or more non-adjacent -CH2- groups in the alkylene group, alkenylene group, alkyleneoxy group, or arylene group may be substituted with -O-, -COO-, or -OCO-. In the above general formula (1), M 2 is preferably an alkylene group having 3 to 12 carbon atoms, a linear, branched or cyclic alkylene group having 3 to 12 carbon atoms, or an arylene group having 6 to 18 carbon atoms, not including the number of carbon atoms of the substituent. 2 The substituent of is preferably an alkyl group or an alkoxy group.

[0047] Specific examples of the polyisocyanate compound (I) of this embodiment include 1,5-naphthylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 4,4'-diphenyldimethylmethane diisocyanate, 4,4'-dibenzyl isocyanate, dialkyldiphenylmethane diisocyanate, tetraalkyldiphenylmethane diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, tolylene diisocyanate, butane-1,4-diisocyanate, hexamethylene diisocyanate, isopropylene diisocyanate, methylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, lysine diisocyanate, methyl ... Preferred examples of the polyisocyanate compounds (I) include cyclohexane-1,4-diisocyanate, xylylene diisocyanate, isophorone diisocyanate, dimeryl diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, 1,3-bis(isocyanatomethyl)cyclohexane, methylcyclohexane diisocyanate, norbornane diisocyanate, m-tetramethylxylylene diisocyanate, 4,4-diphenylmethane diisocyanate, tolylene diisocyanate, bis-chloromethyl-diphenylmethane-diisocyanate, 2,6-diisocyanato-benzyl chloride, and dimer diisocyanates in which the carboxyl groups of dimer acids are converted to isocyanate groups. These polyisocyanate compounds (I) can be used alone or in combination of two or more. Among these, 4,4'-diphenylmethane diisocyanate, 4,4'-dibenzyl isocyanate, tolylene diisocyanate, hexamethylene diisocyanate, isopropylene diisocyanate, methylene diisocyanate, cyclohexane-1,4-diisocyanate, xylylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, 1,3-bis(isocyanatomethyl)cyclohexane, methylcyclohexane diisocyanate, 4,4-diphenylmethane diisocyanate, and tolylene diisocyanate are more preferred, and tolylene diisocyanate or isophorone diisocyanate is even more preferred.

[0048] In the reaction raw material (I) of the urethane resin (I) of this embodiment, the proportion of the polyisocyanate compound (I) relative to the total amount (100% by mass) of the reaction raw material (I) is preferably 5 to 60% by mass, more preferably 10 to 50% by mass, and even more preferably 15 to 40% by mass. In the urethane resin (I) (resin solids) of this embodiment, the content of the polyisocyanate compound (I)-derived structural unit (so-called polyisocyanate compound (I) residue) in the urethane resin (I) is preferably in the range of 5 to 60 mass% relative to the total urethane resin (I) (resin solids), more preferably 10 to 50 mass%, and even more preferably 15 to 40 mass%. When the content of the polyisocyanate compound (I)-derived structural unit is 15 parts by mass or more per 100 parts by mass of the urethane resin (I), the extrusion laminate strength is further improved. When the content is 40 parts by mass or less, the flexibility of the ink coating (good conformity to the substrate) is improved.

[0049] <Second Polyol Component> The reactive raw material (I) of the urethane resin (I) of this embodiment essentially contains a polyester polyol (I) as a second polyol component, which provides the effects of improving boiling and retort resistance and substrate adhesion. In the reaction raw material (I) of this embodiment, the content of the second polyol component relative to the entire reaction raw material (I) (100% by mass) is preferably 30% by mass or more and 95% by mass or less, more preferably 40% by mass or more and 85% by mass or less, and even more preferably 50% by mass or more and 80% by mass or less. In the second polyol component of this embodiment, the content of the polyester polyol (I) relative to the entire second polyol component (100% by mass) is preferably 50% by mass or more and 100% by mass or less, more preferably 60% by mass or more and 95% by mass or less, and even more preferably 70% by mass or more and 90% by mass or less. The second polyol component of the present embodiment may contain a polyether polyol (I) as needed. The second polyol component containing the polyester polyol (I) and the polyether polyol (I) has the effect of improving the heat resistance and the solubility in a solvent. When the second polyol component of this embodiment contains the polyether polyol (I), The content of the polyether polyol (I) relative to the entire second polyol component (100% by mass) is preferably 1% by mass or more and 90% by mass or less, more preferably 3% by mass or more and 50% by mass or less, and even more preferably 5% by mass or more and 20% by mass or less.

[0050] The second polyol component of the present embodiment may contain, in addition to the polyester polyol (I) and the polyether polyol (I) blended as needed, other polyols described below. In this case, examples of the other polyols include aromatic polyols. In the second polyol component of this embodiment, the total content of the polyester polyol (I), the polyether polyol (I), and the aromatic polyol is preferably 95% by mass or more and 100% by mass or less, more preferably 97% by mass or more and 99% by mass or less, and even more preferably 98% by mass or more and 98.5% by mass or less, based on the entire second polyol component (100% by mass).

[0051] <Polyester polyol (I)> The reaction raw material (I) for the urethane resin (I) of this embodiment may contain a polyester polyol (I). In the reactive raw material (I) of the urethane resin (I) of this embodiment, the proportion of the polyester polyol (I) is preferably 10 to 90 mass % relative to the total amount (100 mass %) of the reactive raw material (I), and more preferably 35 to 75 mass %. In the urethane resin (I) of this embodiment, the content of the structural unit derived from the polyester polyol (I) (so-called polyester polyol (I) residue) in the urethane resin (I) is preferably in the range of 10 to 90% by mass, more preferably 35 to 75% by mass, based on the total urethane resin (I) (resin solid content). When the content of the polyester polyol structural unit is 30 parts by mass or more per 100 parts by mass of the urethane resin (I), the effect of improving heat resistance is achieved.

[0052] The polyester polyol (I) of this embodiment can be, for example, one obtained by a known esterification reaction between a compound having two or more hydroxyl groups and a polybasic acid. More specifically, it is preferably a compound obtained by dehydration condensation or polymerization of a low-molecular-weight polyol and a polycarboxylic acid or an anhydride thereof. The polyester polyol can further improve laminate strength by introducing ester groups to increase cohesive energy.

[0053] As the low molecular weight polyol, various known compounds having two or more hydroxyl groups that are generally used in the production of known polyester polyols can be used. For example, one or more compounds may be used in combination as the polyester polyol (I). Specific examples of the low molecular weight polyol include glycols such as ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, 1,4-cyclohexanediol, and 1,4-cyclohexanedimethanol; 2-methyl-1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,2-butanediol, 1,3-butanediol, and 2-butyl-2- Glycols having a branched structure such as ethyl-1,3-propanediol, 1,2-propanediol, 2-methyl-1,3-propanediol, neopentyl glycol, 2-isopropyl-1,4-butanediol, 2,4-dimethyl-1,5-pentanediol, 2,4-diethyl-1,5-pentanediol, 2-ethyl-1,3-hexanediol, 2-ethyl-1,6-hexanediol, 3,5-heptanediol, and 2-methyl-1,8-octanediol; glycerin, trimethylolpropane, trimethylolethane, pentaerythritol, and sorbitol can be used.

[0054] The polycarboxylic acid or anhydride thereof may be any of various known polycarboxylic acids commonly used in the production of known polyester polyols. One or more of the polycarboxylic acids or anhydrides thereof may be used in combination. Specific examples include polycarboxylic acids having 6 or less carbon atoms and two or more carboxyl groups, such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, fumaric acid, maleic acid, and anhydrides thereof; aromatic dicarboxylic acids, such as phthalic acid, isophthalic acid, terephthalic acid, and anhydrides thereof; aliphatic dicarboxylic acids, such as pimelic acid, suberic acid, azelaic acid, sebacic acid, and dimer acid; tricarboxylic acids, such as trimellitic acid and anhydrides thereof; benzenetetracarboxylic acid, benzenepentacarboxylic acid, benzenehexacarboxylic acid, and anhydrides thereof.

[0055] The polyester polyol (I) may be any of various known polyester polyols commonly used in the production of known polyurethane resins, such as polyester polyols obtained by ring-opening polymerization of cyclic ester compounds, for example, lactones such as polycaprolactone, polyvalerolactone, and poly(β-methyl-γ-valerolactone), or one or more of these compounds may be used in combination.

[0056] The number average molecular weight of the polyester polyol (I) is preferably in the range of 500 to 8,000, more preferably in the range of 800 to 7,000, and even more preferably in the range of 900 to 6,000.

[0057] The hydroxyl value of the polyester polyol (I) of the present embodiment may be preferably 14.025 to 224.4 mgKOH / g, more preferably 16.02 to 140.25 mgKOH / g, and even more preferably 18.7 to 124.6 mgKOH / g. When the hydroxyl value of the polyester polyol (I) is within the above range, the urethane bond concentration can be easily controlled to a predetermined value or higher, and therefore the laminate strength can be further improved.

[0058] <Polyether polyol (I)> The reaction raw material (I) for the urethane resin (I) of this embodiment may contain a polyether polyol (I) as needed. In the reaction raw material (I) of the urethane resin (I) of this embodiment, the proportion of the polyether polyol (I) relative to the total amount (100% by mass) of the reaction raw material (I) is preferably 0 to 50% by mass, more preferably 1 to 50% by mass, and even more preferably 5 to 25% by mass. The polyether polyol (I) of this embodiment can be any of various known polyether polyols commonly used in the production of polyurethane resins, and one or more of these may be used in combination. Examples include polyether polyols of polymers or copolymers of methylene oxide, ethylene oxide, propylene oxide, tetrahydrofuran, and the like. Specifically, known, general-purpose polyether polyols such as polyethylene glycol, polypropylene glycol, and polytetramethylene glycol may be used. By including the polyether polyol (I) in the reaction raw material (I), adhesion, particularly to high-performance barrier films, is significantly improved, resulting in excellent blocking resistance and laminate strength. The number average molecular weight of the polyether polyol (I) is preferably 100 to 3500, more preferably 150 to 2000, and even more preferably 200 to 1000. If the number average molecular weight of the polyether polyol (I) is less than 100, the polyurethane resin (A) film tends to be hard, resulting in reduced adhesion to polyester films. If the number average molecular weight is more than 3500, the polyurethane resin film tends to be brittle, resulting in reduced blocking resistance of the ink film. When the urethane resin (I) (resin solids) of this embodiment contains structural units of polyether polyol (I), the structural units of the polyether polyol (I) contained in the urethane resin (I) (resin solids) are preferably contained in a range of 1 to 40% by mass, more preferably 2 to 30% by mass, and even more preferably 3 to 20% by mass, based on the total mass of the urethane resin (I). If the amount of polyether polyol (I) is less than 1 part by mass per 100 parts by mass of the urethane resin (I), the solubility of the urethane resin (I) in ketone, ester, and alcohol-based solvents tends to decrease, resulting in poor adhesion to high-performance barrier films. Furthermore, the resolubility of the ink film in these solvents tends to decrease, resulting in poor tone reproducibility of printed matter. Furthermore, if the amount exceeds 40 parts by mass, the ink film tends to become excessively soft, resulting in poor blocking resistance. The hydroxyl value of the polyether polyol (I) of the present embodiment may be preferably 22.44 to 561 mgKOH / g, more preferably 56.1 to 448.8 mgKOH / g, and even more preferably 112.2 to 374 mgKOH / g. When the hydroxyl value of the polyether polyol (I) is within the above range, the urethane bond concentration can be easily controlled to a predetermined value or higher, and therefore, the laminate strength can be further improved.

[0059] If necessary, the reaction raw material (I) may further contain a polyether polyol (I) and / or other polyols described below. In the reactive raw material (I) of the urethane resin (I) of this embodiment, the proportion of the total of the polyester polyol (I) and the polyether polyol (I) relative to the total amount (100% by mass) of the reactive raw material (I) is preferably 40 to 90% by mass, and more preferably 50 to 85% by mass. That is, the polyol structure of the urethane resin (I) preferably contains a structural unit derived from the polyester polyol (I) to improve the laminate strength, and further preferably contains a structural unit derived from the polyether polyol (I) to improve the dispersibility and fluidity of the ink and also improve the adhesion. In the reactive raw material (I) of the urethane resin (I) of this embodiment, the proportion of all polyol components (the sum of the first polyol component and the second polyol component) relative to the total amount (100% by mass) of the reactive raw material (I) is preferably 40 to 95% by mass, and more preferably 60 to 85% by mass.

[0060] <Aromatic polyol> The reaction raw material (I) of the urethane resin (I) of this embodiment may contain an aromatic polyol as a second polyol component, if necessary. That is, a suitable example of the urethane resin (I) of this embodiment may be a resin in which the reaction raw materials (I) are a polydiene polyol and / or a hydrogenated polydiene polyol, a polyester polyol, a polyisocyanate compound (I), and an aromatic polyol. The aromatic polyol preferably has a partial structure represented by the following general formula (2): When the urethane resin (I) has an aromatic ring, it is more likely to exhibit the effects of improving blocking properties, improving the gloss of the ink coating film, and improving pigment dispersibility. That is, the aromatic polyol of the present embodiment preferably has a partial structure represented by the following general formula (2). [ka] (In the above general formula (2), D 1 represents a hydrogen atom, a hydroxyl group, or an alkyl group having 1 to 15 carbon atoms, provided that one or more -CH2- groups in the alkyl group may be substituted with -O-, -COO-, or -OCO-; L 1 and L 2 each independently represents a single bond or an alkylene group having 1 to 5 carbon atoms, L 4 each independently represents a mezine group (-CH=), a trivalent alicyclic group having 3 to 15 carbon atoms, or a trivalent aromatic group; R 1 each independently represents a monovalent aromatic group; M 1each independently represents a mezine group (-CH=), a trivalent alicyclic group having 3 to 15 carbon atoms, or a trivalent aromatic group; ni is the number of repeating units and represents an integer of 2 or more. In this embodiment, in the general formula (2), D 1 is preferably a hydrogen atom, a hydroxyl group, or an alkyl group having 1 to 3 carbon atoms. In the above general formula (2), L 1 is preferably an alkylene group having 1 to 3 carbon atoms, and particularly preferably a methylene group. In the above general formula (2), L 2 is preferably a single bond or an alkylene group having 1 to 3 carbon atoms, more preferably a single bond. L 4 is preferably a medin group. 1 is preferably a monovalent aromatic group that is unsubstituted or has 1 to 4 hydrogen atoms substituted with a substituent, and is more preferably a phenyl group, naphthyl group, phenalenyl group, phenanthrenyl group, anthryl group, azulenyl group, indenyl group, indanyl group, or tetralinyl group that is unsubstituted or has 1 to 3 hydrogen atoms substituted with a substituent. The substituent is preferably an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, or a halogen atom. In the above general formula (2), M 1 is preferably a mezine group or a trivalent alicyclic group having 4 to 8 carbon atoms (for example, cyclohexane-triyl which may be substituted with an alkyl group having 1 to 3 carbon atoms), and is particularly preferably a mezine group. In the above general formula (2), ni is preferably an integer of 2 or more and 50 or less, and more preferably 2 or more and 10 or less.

[0061] The aromatic polyol of the present embodiment more preferably has a structure represented by the following general formula (2-1). [ka] (In the above general formula (2-1), D 1represents a hydrogen atom, a hydroxyl group, or an alkyl group having 1 to 15 carbon atoms, provided that one or more -CH2- groups in the alkyl group may be substituted with -O-, -COO-, or -OCO-; L 1 and L 2 each independently represents a single bond or an alkylene group having 1 to 5 carbon atoms, M 1 each independently represents a mezine group (-CH=), a trivalent alicyclic group having 3 to 15 carbon atoms, or a trivalent aromatic group; R 31 each independently represents a halogen atom, an amino group, a cyano group, a hydroxyl group, an alkyl group having 1 to 5 carbon atoms, or an alkoxy group having 1 to 5 carbon atoms; n31 represents an integer of 0 to 4, ni is the number of repeating units and represents an integer of 2 or more.

[0062] The aromatic polyol of this embodiment has a number average molecular weight (Mn) of 100-4,000, preferably 300-2,000, and more preferably 700-900. A number-average molecular weight (Mn) of 700 to 900 of the aromatic polyol is preferable from the viewpoint of the balance between viscosity and hardness. If the number-average molecular weight of the aromatic polyol is too small, the cured urethane resin film tends to be hard, resulting in reduced adhesion to the film. On the other hand, if the number-average molecular weight is too large, the cured urethane resin film tends to be brittle, resulting in reduced blocking resistance of the ink film.

[0063] The hydroxyl value of the aromatic polyol of the present embodiment may be preferably 28.05 to 1122 mgKOH / g, more preferably 56.1 to 374 mgKOH / g, and even more preferably 124.66 to 160.28 mgKOH / g. When the hydroxyl value of the aromatic polyol is within the above range, the urethane bond concentration can be easily controlled to a predetermined value or more, and therefore the laminate strength can be further improved.

[0064] When the reaction raw material (I) of the urethane resin (I) of this embodiment contains an aromatic polyol, the proportion of the aromatic polyol relative to the total amount (100% by mass) of the reaction raw material (I) is preferably from more than 0 to 90% by mass, more preferably from more than 0 to 40% by mass, and even more preferably from more than 0 to 20% by mass. That is, when the urethane resin (I) further contains structural units derived from an aromatic polyol, an ink layer having a better balance of blocking resistance, adhesion, and laminate strength can be formed. This is particularly preferable because it can improve laminate strength. Furthermore, if necessary, it is preferable to further contain structural units derived from other polyols, because this can improve the dispersibility and fluidity of the ink and also improve adhesion. In this embodiment, the content of aromatic polyol-derived structural units (so-called aromatic polyol residues) is preferably in the range of 0 to 90% by mass, more preferably 0 to 40% by mass, and even more preferably 0 to 20% by mass, based on the total urethane resin (I) (resin solids). When the content of aromatic polyol-derived structural units is 3 parts by mass or more per 100 parts by mass of urethane resin (I), the urethane resin (I) is ensured to have good solubility in ketone, ester, and alcohol-based solvents, resulting in good adhesion to high-performance barrier films. Furthermore, the ink film is easily resolubilized in the solvent, improving tone reproducibility of printed matter. Furthermore, when the content is 20 parts by mass or less, the ink film has adequate flexibility, which tends to improve blocking resistance.

[0065] (Properties of urethane resin (I)) The urethane resin (I) of this embodiment has a weight average molecular weight (Mw) of 5,000 to 300,000, preferably 10,000 to 200,000, and more preferably 20,000 to 100,000. A number average molecular weight (Mn) of 10,000 to 50,000 of the urethane resin (I) is preferred from the viewpoints of the viscosity of the ink composition, blocking resistance, strength and oil resistance of the printed film, and gloss of the printed film.

[0066] (Preferred embodiment of urethane resin (I)) The urethane resin (I) of the present embodiment preferably has a urethane bond concentration of 0.86 mmol / g or more and 2.5 mmol / g or less, has urethane bonds and urea bonds, and is a resin produced from polydiene polyol and / or hydrogenated polydiene polyol, polyester polyol (I), and polyisocyanate compound (I) as reaction raw materials (I). It is believed that a liquid ink composition containing urethane resin (I) can form an excellent ink layer by reducing the environmental load, exhibiting an excellent balance of blocking resistance, adhesion, and laminate strength, and suppressing ink layer peeling after boiling or retort treatment. Furthermore, it has been confirmed that by combining it with urethane resin (II) or a binder resin described below, it is possible to form an ink layer that exhibits excellent extrusion laminate strength and suppresses ink layer peeling after boiling or retort treatment.

[0067] (organic solvent) The organic solvent used in the liquid ink composition of this embodiment may be any of a variety of organic solvents, and is preferably one or more selected from the group consisting of aromatic organic solvents, ketone-based organic solvents, ester-based organic solvents, alcohol-based organic solvents, and glycol ether-based organic solvents. Examples of the aromatic organic solvent include toluene and xylene. Examples of the ketone organic solvent include acetone, methyl ethyl ketone, and methyl isobutyl ketone. Examples of the ester organic solvent include ethyl acetate, n-propyl acetate, butyl acetate, and propylene glycol monomethyl ether acetate. The alcohol-based organic solvent is preferably an aliphatic alcohol having a boiling point of less than 160°C, for example, an alcohol having 1 to 15 carbon atoms, and specific examples thereof include n-propanol, isopropanol, n-butanol, propylene glycol monomethyl ether, 3-methyl-1-butanol, 2-methyl-1-butanol, 2,2-dimethyl-1-propanol, 3-methyl-2-butanol, 2-methyl-2-butanol, isobutanol, and 2-pentanol. The glycol ether organic solvent is preferably a glycol ether solvent having a boiling point of 160° C. or less, and examples thereof include at least one selected from the group consisting of ethylene glycol ethers and propylene glycol ethers. The ethylene glycol ethers are preferably ethylene glycol monoalkyl ethers, and the propylene glycol ethers are preferably propylene glycol monoalkyl ethers. The alkyl ether group in the ethylene glycol monoalkyl ether and propylene glycol monoalkyl ether preferably has 1 to 4 carbon atoms. Preferred ethylene glycol monoalkyl ethers are ethylene glycol monopropyl ether and ethylene glycol mono(iso)propyl ether, and preferred propylene glycol monoalkyl ether is propylene glycol monomethyl ether. The glycol ether organic solvent may be esterified, and examples thereof include ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether acetate, and propylene glycol monoethyl ether acetate. These glycol ether organic solvents may be used alone or in combination of two or more. It is more preferable to use ethylene glycol monoalkyl ether and propylene glycol monoalkyl ether in combination. Specific examples of the glycol ether organic solvent include ethylene glycol monomethyl ether, ethylene glycol mono-n-propyl ether, ethylene glycol monoisopropyl ether, propylene glycol monomethyl ether, and propylene glycol mono-n-propyl ether. The organic solvents exemplified above can be used alone or in a mixture of two or more. In recent years, from the viewpoint of the working environment, it is preferable not to use aromatic organic solvents such as toluene and xylene or ketone organic solvents.

[0068] The organic solvent preferably contains the ester-based organic solvent and the alcohol-based organic solvent, and the mass ratio thereof is preferably set to ester-based organic solvent:alcohol-based organic solvent = 30:70 to 95:5. When the mass ratio in the organic solvent is within this range, the ink can have excellent printability and blocking resistance. The mass ratio is more preferably 40:60 to 90:10, and even more preferably 60:40 to 85:15.

[0069] The liquid ink composition of this embodiment may contain water as a volatile component in addition to the organic solvent. The water content is preferably less than 10% by mass of the total ink composition. The addition of water can control the drying speed of the ink, and in particular, in gravure printing, it is possible to beautifully reproduce the gradation areas characterized by low ink transfer. Furthermore, it is particularly preferable that the water content be in the range of 0.5 to 5% by mass of the total liquid ink composition, as this improves printability. Furthermore, by adding water in this manner, it is possible to reduce the amount of organic solvent used. Water may be added to the organic solvent in advance to form a water-containing mixed solvent, or a specific amount of water may be added separately. The liquid ink composition of this embodiment can be a one-component type that does not use a curing agent such as an isocyanate curing agent, or a two-component type that does use a curing agent, and can provide a liquid ink composition with excellent ink dispersibility and flowability.

[0070] <Water> The liquid ink composition of this embodiment may contain water as needed. When the liquid ink composition contains water, the water content is preferably 0.1 to 10 mass% based on the total mass of the liquid ink composition. By including a predetermined amount of water in the liquid ink composition, the pigment dispersibility of the urethane resin (I) and, if necessary, the urethane resin (II) or binder resin is improved, and printability such as highlight transfer, plate fogging, and trapping properties is improved. When the liquid ink composition of this embodiment contains water, the water content is preferably 0.2 to 7 mass%, more preferably 0.3 to 5 mass%, and even more preferably 0.5 to 4 mass%, based on the total mass of the liquid ink composition. Furthermore, as described above, printability is further improved by using the liquid ink composition in combination with an alcohol-based organic solvent or a glycol ether-based organic solvent having a boiling point of 100 to 160°C.

[0071] When the liquid ink composition of this embodiment contains water, the blending ratio of water to the alcohol-based organic solvent and / or glycol ether-based organic solvent (mass of water:mass of alcohol-based organic solvent and / or glycol ether-based organic solvent) is preferably 95:5 to 5:95, more preferably 90:10 to 10:90, and even more preferably 80:20 to 20:80. When the liquid ink composition of this embodiment contains water, the total content of water, the alcohol-based organic solvent, and the glycol ether-based organic solvent is preferably 1 to 20 mass %, more preferably 2 to 15 mass %, even more preferably 3 to 10 mass %, and particularly preferably 3 to 8 mass %, based on the total amount of the liquid ink composition.

[0072] (Urethane resin (II)) The liquid ink composition of this embodiment may contain a urethane resin (II) other than the urethane resin (I) described above. The liquid ink composition of this embodiment contains both the urethane resin (I) and the urethane resin (II) having a chemical structure different from that of the urethane resin (I), and therefore has the function of further improving the adhesion of the ink as a binder resin, and can also function better as a pigment dispersing resin. The urethane resin (II) of this embodiment is not particularly limited as long as it is a urethane resin other than the urethane resin (I) described above, has a urethane bond, and is obtained by reacting a polyol compound with a polyisocyanate-based compound (II). The polyol compound is preferably one or more selected from the group consisting of polyester polyol (II), polyether polyol (II), and the aromatic polyol. Therefore, the urethane resin (II) preferably uses a polyisocyanate-based compound (II) and a polyol compound as reaction raw materials (II). In other words, the urethane resin (II) in this embodiment has a structure in which a structural unit derived from the polyisocyanate compound (II) and a structural unit derived from the polyol compound are chemically bonded directly or indirectly. For convenience, in this specification, the reaction raw material for the urethane resin (II) is referred to as the reaction raw material (II), and is distinguished from the reaction raw material (I) for the urethane resin (I).

[0073] When the liquid ink composition of this embodiment contains urethane resin (II), the content of urethane resin (II) is preferably 1 to 90 mass%, more preferably 10 to 80 mass%, even more preferably 25 to 65 mass%, even more preferably 30 to 55 mass%, and particularly preferably 40 to 55 mass%, based on the total resin solids content (100 mass%) of the liquid ink composition. By making the content of urethane resin (II) 40 mass% or more, the performance of urethane resin (II) is exhibited. On the other hand, by making the content of urethane resin (II) 10 mass% or less, the performance of urethane resin (I) is exhibited. When the liquid ink composition of this embodiment contains urethane resin (II), the content of urethane resin (II) is preferably 1 to 90 mass%, more preferably 10 to 80 mass%, even more preferably 30 to 70 mass%, and even more preferably 40 to 60 mass%, relative to the total resin solid content (100 mass%) of the urethane resin component. When the liquid ink composition of this embodiment contains a urethane resin (II), the amine value of the urethane resin (II) is preferably 10 mgKOH / g or less, more preferably 0.1 to 3.0 mgKOH / g, and even more preferably 0.2 to 2.0 mgKOH / g, from the viewpoint of substrate adhesion.

[0074] <Polyisocyanate compounds (II)> The reaction raw material (II) for the urethane resin (II) of this embodiment contains a polyisocyanate compound (II). The polyisocyanate compound (II) used for the urethane resin (II) in the ink composition of this embodiment is preferably a compound having two or more isocyanate groups, and more preferably a dipolyisocyanate compound. As the polyisocyanate compound (II), the same compounds as the polyisocyanate compound (I) can be used, and examples thereof include various known aromatic diisocyanates, aliphatic diisocyanates, and alicyclic diisocyanates that are commonly used in the production of known polyurethane resins. As the polyisocyanate compound (II), the same compounds as those used as the polyisocyanate compound (I) can be used, for example, 1,5-naphthylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 4,4'-diphenyldimethylmethane diisocyanate, 4,4'-dibenzyl isocyanate, dialkyldiphenylmethane diisocyanate, tetraalkyldiphenylmethane diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, tolylene diisocyanate, butane-1,4-diisocyanate, hexamethylene diisocyanate, isopropylene diisocyanate, methylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, Examples of suitable polyisocyanate compounds include isocyanate, lysine diisocyanate, cyclohexane-1,4-diisocyanate, xylylene diisocyanate, isophorone diisocyanate, dimeryl diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, 1,3-bis(isocyanatomethyl)cyclohexane, methylcyclohexane diisocyanate, norbornane diisocyanate, m-tetramethylxylylene diisocyanate, 4,4-diphenylmethane diisocyanate, tolylene diisocyanate, bis-chloromethyl-diphenylmethane-diisocyanate, 2,6-diisocyanato-benzyl chloride, and dimer diisocyanate in which the carboxyl groups of dimer acid are converted to isocyanate groups. These polyisocyanate compounds (II) can be used alone or in combination of two or more.

[0075] In the reaction raw material (II) of the urethane resin (II) of this embodiment, the proportion of the polyisocyanate compound (II) is preferably 5 to 50 mass % and more preferably 15 to 40 mass % relative to the total amount (100 mass %) of the reaction raw material (II). The content of the structural unit derived from the polyisocyanate compound (II) in the urethane resin (II) (so-called polyisocyanate compound (II) residue) is preferably in the range of 5 to 50 mass %, more preferably 10 to 40 mass %, relative to the urethane resin (II).

[0076] <Polyol compounds> The reaction raw material (II) for the urethane resin (II) of this embodiment contains at least a polyol compound, which may be one or more selected from the group consisting of polyester polyol (II), polyether polyol (II), the aromatic polyols described above, and other polyols. <<Polyester polyol (II)>> The reaction raw material (II) for the urethane resin (II) of this embodiment preferably contains at least a polyester polyol (II). In one aspect of the urethane resin (II) of the present embodiment, when the polyester polyol (II) and the polyether polyol (II) are used as part of the reaction raw materials (II), it is preferable that the mass proportion of the polyester polyol (II) is higher in the total mass of the polyester polyol (II) and the polyether polyol. In the reaction raw material (II) of the urethane resin (II) of this embodiment, the proportion of the total of the polyester polyol (II) and the polyether polyol (II) relative to the total amount (100% by mass) of the reaction raw material (II) is preferably 20 to 95% by mass, more preferably 50 to 90% by mass. In the reaction raw material (II) of the urethane resin (II) of this embodiment, the proportion of the polyester polyol (II) is preferably 0 to 95 mass % relative to the total amount (100 mass %) of the reaction raw material (II), and more preferably 30 to 90 mass %. That is, the polyol structure of the urethane resin (II) preferably contains a structural unit derived from the polyester polyol (II) to improve laminate strength and heat resistance, and further contains a structural unit derived from the polyether polyol (II) and / or an aromatic polyol to improve the dispersibility and fluidity of the ink and also improve adhesion.

[0077] In the present embodiment, the mass ratio of the polyester polyol (II) to the polyether polyol (II) in the polyol structure (structure having two or more hydroxyl groups) (polyester polyol (II):polyether polyol) is preferably in the range of 45:55 to 100:0, more preferably in the range of 50:50 to 100:0, and even more preferably in the range of 55:45 to 99:1. A mass ratio of the polyester polyol (II) to the polyether polyol (II) within the range of 45:55 to 100:0 is preferable because it allows for the production of printed matter that is less prone to blocking, and a mass ratio within the range of 55:45 to 99:1 is preferable because it allows for the production of ink that is particularly excellent in lamination strength, adhesion, and ink dispersibility. Furthermore, in the liquid ink composition of this embodiment, when a polyvinyl butyral resin is used in combination as a binder resin, compatibility is good so long as the mass ratio of the polyester polyol (II) to the polyether polyol (II) is within the range of 55:45 to 98:2, and therefore suitable storage stability and fluidity can be obtained.

[0078] The polyester polyol (II) of this embodiment is preferably a compound obtained by dehydration condensation or polymerization of a low-molecular-weight polyol and a polycarboxylic acid or an anhydride thereof. The polyester polyol (II) can further improve laminate strength by introducing an ester group to increase cohesive energy.

[0079] As the low molecular weight polyol, various known compounds having two or more hydroxyl groups that are generally used in the production of known polyester polyols can be used. For example, one or more compounds may be used in combination as the polyester polyol (II). Specific examples of the low molecular weight polyol include glycols such as ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, 1,4-cyclohexanediol, and 1,4-cyclohexanedimethanol; 2-methyl-1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,2-butanediol, 1,3-butanediol, and 2-butyl-2- Glycols having a branched structure such as ethyl-1,3-propanediol, 1,2-propanediol, 2-methyl-1,3-propanediol, neopentyl glycol, 2-isopropyl-1,4-butanediol, 2,4-dimethyl-1,5-pentanediol, 2,4-diethyl-1,5-pentanediol, 2-ethyl-1,3-hexanediol, 2-ethyl-1,6-hexanediol, 3,5-heptanediol, and 2-methyl-1,8-octanediol; glycerin, trimethylolpropane, trimethylolethane, pentaerythritol, and sorbitol can be used.

[0080] The polycarboxylic acid or anhydride thereof may be any of various known polycarboxylic acids commonly used in the production of known polyester polyols. One or more of the polycarboxylic acids or anhydrides thereof may be used in combination. Specific examples include polycarboxylic acids having 6 or less carbon atoms and two or more carboxyl groups, such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, fumaric acid, maleic acid, and anhydrides thereof; aromatic dicarboxylic acids, such as phthalic acid, isophthalic acid, terephthalic acid, and anhydrides thereof; aliphatic dicarboxylic acids, such as pimelic acid, suberic acid, azelaic acid, sebacic acid, and dimer acid; tricarboxylic acids, such as trimellitic acid and anhydrides thereof; benzenetetracarboxylic acid, benzenepentacarboxylic acid, benzenehexacarboxylic acid, and anhydrides thereof.

[0081] The polyester polyol (II) may be any of various known polyester polyols generally used in the production of known polyurethane resins, such as polyester polyols obtained by ring-opening polymerization of cyclic ester compounds, for example, lactones such as polycaprolactone, polyvalerolactone, and poly(β-methyl-γ-valerolactone), or one or more of these compounds may be used in combination.

[0082] The number average molecular weight of the polyester polyol (II) is preferably in the range of 500 to 8,000, more preferably in the range of 800 to 7,000, and even more preferably in the range of 900 to 6,000. The hydroxyl value of the polyester polyol (II) of the present embodiment may be preferably 14.025 to 224.4 mgKOH / g, more preferably 16.028 to 140.25 mgKOH / g, and even more preferably 18.7 to 124.66 mgKOH / g. When the hydroxyl value of the polyester polyol (II) is within the above range, the urethane bond concentration can be easily controlled to a predetermined value or higher, and therefore, the laminate strength can be further improved.

[0083] The content of the polyester polyol (II) structural unit is preferably in the range of 0 to 90% by mass, more preferably 40 to 80% by mass, relative to the urethane resin (II). When the polyester polyol (II) is 50 parts by mass or more per 100 parts by mass of the urethane resin (II), the urethane resin (II) is guaranteed to have good solubility in ketone, ester, and alcohol-based solvents, resulting in good adhesion to high-performance barrier films. Furthermore, the ink film is easily resolubilized in the solvent, improving tone reproducibility of printed matter. When the content is 40 parts by mass or less, the ink film has adequate flexibility, which tends to result in good blocking resistance.

[0084] <<Polyether polyol (II)>> The reaction raw material (II) of the urethane resin (II) of this embodiment may contain a polyether polyol (II). The polyether polyol (II) is the same as the polyether polyol (I) that is an optional component of the reaction raw material (I). Among these, polyethylene glycol, polypropylene glycol, or polytetramethylene glycol is preferred as the polyether polyol (II). By including the polyether polyol (II), adhesion, particularly to a high-performance barrier film, is significantly improved, resulting in excellent blocking resistance and laminate strength.

[0085] The number-average molecular weight of the polyether polyol (II) is preferably 100 to 3500. If the number-average molecular weight of the polyether polyol (II) is less than 100, the polyurethane resin film tends to be hard, resulting in reduced adhesion to polyester films. If the number-average molecular weight is more than 3500, the resulting resin film tends to be brittle, resulting in reduced blocking resistance of the ink film. The hydroxyl value of the polyether polyol (II) of the present embodiment may be preferably 22.44 to 600 mgKOH / g, more preferably 56.1 to 448.8 mgKOH / g, and even more preferably 112.2 to 374 mgKOH / g. When the hydroxyl value of the polyether polyol (II) is within the above range, the urethane bond concentration can be easily controlled to a predetermined value or higher, and therefore the laminate strength can be further improved.

[0086] In the reaction raw material (II) of the urethane resin (II) of this embodiment, the proportion of the polyether polyol (II) is preferably 0 to 60 mass % and more preferably 5 to 50 mass % relative to the total amount (100 mass %) of the reaction raw material (II). The polyether polyol (II) structural unit is preferably contained in the range of 0 to 50% by mass relative to the urethane resin (II). When the polyether polyol is 5 parts by mass or more per 100 parts by mass of the urethane resin (II), the urethane resin (II) is guaranteed to have good solubility in ketone, ester, and alcohol-based solvents, resulting in good adhesion to high-performance barrier films. Furthermore, the ink film is easily resolubilized in the solvent, improving tone reproducibility of printed matter. When the polyether polyol is 30 parts by mass or less, the ink film has adequate flexibility, which tends to result in good blocking resistance.

[0087] <Aromatic polyol> The reaction raw material (II) of the urethane resin (II) of this embodiment may contain an aromatic polyol. The reaction raw material (II) may contain an aromatic polyol as the polyol compound. The aromatic polyol preferably has a partial structure represented by the general formula (2) above. The urethane resin (II) having an aromatic ring is more likely to exhibit the effects of improving blocking properties, improving the gloss of the ink coating, and enhancing pigment dispersibility. The aromatic polyol to be blended in the reaction raw material (II) is the same as that described above in the <Aromatic Polyol>.

[0088] In the reaction raw material (II) of the urethane resin (II) of this embodiment, the proportion of the aromatic polyol relative to the total amount (100% by mass) of the reaction raw material (II) is preferably 0 to 95% by mass, more preferably 0 to 90% by mass, and even more preferably 0 to 87% by mass. That is, the polyol structure of the urethane resin (II) preferably contains structural units derived from an aromatic polyol, which can improve laminate strength, and further preferably contains structural units derived from a co-used polyol, which can improve the dispersibility and fluidity of the ink and also improve adhesion. In this embodiment, the content of aromatic polyol-derived structural units (so-called aromatic polyol residues) is preferably in the range of 30 to 95% by mass, more preferably 50 to 90% by mass, based on the total urethane resin (II) (resin solids content) (100% by mass). When the content of aromatic polyol-derived structural units is 50% by mass or more based on 100% by mass of the urethane resin (II), the urethane resin (II) is ensured to have good solubility in ketone, ester, and alcohol-based solvents, resulting in good adhesion to high-performance barrier films. Furthermore, the ink film is easily resolubilized in the solvent, improving tone reproducibility of printed matter. Furthermore, when the content is 90% by mass or less, the ink film has adequate flexibility, which tends to improve blocking resistance.

[0089] (Properties of urethane resin (II)) The urethane bond concentration of the urethane resin (II) of this embodiment is preferably 0.98 mmol / g or more, more preferably 1.1 mmol / g or more and 5.0 mmol / g or less, and even more preferably 1.2 mmol / g or more and 3.0 mmol / g or less. The urethane bond concentration of the urethane resin (II) can be calculated by the above formula (a). The urethane resin (II) of the present embodiment has a weight average molecular weight (Mw) of 1,000 to 300,000, preferably 2,000 to 200,000, and more preferably 5,000 to 100,000. When the weight average molecular weight (Mw) of the urethane resin (II) is 5,000 to 150,000, this is preferred from the viewpoints of the blocking resistance of the ink composition, the strength and oil resistance of the printed film, and the gloss of the printed film.

[0090] (Preferred embodiments of urethane resins (I) and (II)) Of the resin components contained in the liquid ink composition of this embodiment, the total amount of urethane resin (I) and urethane resin (II) is preferably 30 to 100 mass %, more preferably 40 to 80 mass %, and even more preferably 45 to 70 mass %, based on the total resin solid content of the liquid ink composition. When the contents of the urethane resins (I) and (II) contained in the liquid ink composition are within the above ranges, it is possible to form an ink layer that reduces the environmental impact, has an excellent balance of blocking resistance, adhesion, and laminate strength, and is inhibited from peeling off after boiling or retort treatment. In the liquid ink composition of this embodiment, the total amount of the urethane resin (I), the urethane resin (II), and the organic solvent is preferably 20 to 99 mass%, more preferably 30 to 95 mass%, and even more preferably 40 to 90 mass%, based on the total amount of the liquid ink composition. In the liquid ink composition of this embodiment, the total amount of the urethane resin (I), the urethane resin (II), the organic solvent, and the pigment is preferably 30 to 99 mass%, more preferably 40 to 98 mass%, and even more preferably 50 to 97 mass%, based on the total amount of the liquid ink composition. In the liquid ink composition of this embodiment, the total amount of the urethane resin (I), the urethane resin (II), the organic solvent, the pigment, and the polyvinyl butyral resin is preferably 31 to 100 mass %, more preferably 41 to 99 mass %, and even more preferably 51 to 98 mass %, based on the total amount of the liquid ink composition. In the liquid ink composition of this embodiment, the total amount of urethane resin (I), urethane resin (II), organic solvent, pigment, and other resins is preferably 40 to 100 mass %, more preferably 60 to 99 mass %, and even more preferably 80 to 98 mass %, based on the total amount of the liquid ink composition. In the liquid ink composition of this embodiment, the solid content of the entire urethane resin component relative to the total solid content of the binder resin is preferably 50% by mass or more, 57% by mass or more, 61% by mass or more, or 67% by mass or more. The upper limit of the solid content of the entire urethane resin component relative to the total solid content of the binder resin is preferably 100% by mass or less, 95% by mass or less, or 90% by mass or less. The upper and lower limits can be combined in any manner.

[0091] <Other polyols> The reaction raw material (I) for the urethane resin (I) and / or the reaction raw material (II) for the urethane resin (II) of the present embodiment may further contain other polyols as necessary. Other polyols that may be used as needed in the urethane resin (I) and / or (II) used in the liquid ink composition of this embodiment include various known polyols that are generally used in the production of the above-mentioned aromatic polyols and polyurethane resins, and may be used alone or in combination of two or more thereof. Examples of such polyols include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 2-methyl-1,3-propanediol, 2-ethyl-2-butyl-1,3-propanediol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, pentanediol, 3-methyl-1,5-pentanediol, hexanediol, octanediol, 1,4-butynediol, 1,4-butylenediol, diethylene glycol, triethylene glycol, dipropylene glycol, glycerin, trimethylolpropane, trimethylolethane, 1,2,6-hexanetriol, 1,2,4-butanetriol, sorbitol, and pentaerythritol. Examples of suitable polyols include saturated or unsaturated low-molecular-weight polyols (1); polycarbonate polyols (2) obtained by reacting the above-mentioned low-molecular-weight polyols with, for example, dimethyl carbonate, diphenyl carbonate, ethylene carbonate, phosgene, etc.; polybutadiene glycols (3); glycols (4) obtained by adding ethylene oxide or propylene oxide to bisphenol A; and acrylic polyols (4) obtained by copolymerizing, in one molecule, one or more hydroxyethyl groups, hydroxypropyl acrylate, hydroxybutyl acrylate, etc., or their corresponding methacrylic acid derivatives, with, for example, acrylic acid, methacrylic acid, or an ester thereof.

[0092] In addition, when polyester polyols (I), (II) and / or polyether polyols (I), (II) are contained as the other polyols, the content of the polyester polyols (I), (II) and / or polyether polyols (I), (II) contained in the other polyols is also included in the mass of the polyester polyols (I), (II) and / or polyether polyols (I), (II) in the polyol structure of the urethane resin (I) and / or urethane resin (II), respectively.

[0093] In the liquid ink composition of this embodiment, the urethane bond concentration of at least one of the urethane resin (I) and the urethane bond concentration of the urethane resin (II) is preferably 0.86 mmol / g or more, more preferably 0.91 mmol / g or more and 4.0 mmol / g or less, and even more preferably 1.05 mmol / g or more and 2.0 mmol / g or less. When at least one of the urethane bond concentrations of urethane resin (I) and urethane resin (II) is 0.86 mmol / g or more, it becomes easier to control the urethane bond concentration of the entire urethane resin component to 0.86 mmol / g or more. Since a high urethane bond concentration tends to harden the coating film, an ink composition with particularly excellent scratch resistance can be provided.

[0094] (Method for producing urethane resins (I) and (II)) The polyurethane resins (I) and (II) in the liquid ink composition of this embodiment can be produced, for example, by a two-stage method in which polyols having two or more hydroxyl groups are reacted with isocyanates in a ratio such that the isocyanate groups are in excess to obtain a prepolymer having terminal isocyanate groups, and the obtained prepolymer is reacted with a chain extender and / or a terminal blocking agent in a suitable solvent, or by a one-stage method in which polyols having two or more hydroxyl groups, isocyanates, a chain extender and / or a terminal blocking agent are reacted all at once in a suitable solvent selected from the above. When producing the polyurethane resin (I), examples of the polyols having two or more hydroxyl groups include polydiene polyols and / or hydrogenated polydiene polyols, polyester polyol (I), and optionally one or more selected from the group consisting of polyether polyols (II) and aromatic polyols, and optionally other polyols. On the other hand, when producing polyurethane resin (II), the polyols having two or more hydroxyl groups include one or more selected from the group consisting of polyester polyol (II), polyether polyol (II) and aromatic polyol, and other polyols added as needed. The isocyanates include one or more compounds selected from the group consisting of polyisocyanate compounds (I) and polyisocyanate compounds (II). Examples of the solvent include ester-based solvents such as ethyl acetate, propyl acetate, and butyl acetate, which are commonly used as solvents for non-toluene gravure inks; ketone-based solvents such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; alcohol-based solvents such as methanol, ethanol, isopropyl alcohol, and n-butanol; hydrocarbon-based solvents such as methylcyclohexane and ethylcyclohexane; and mixed solvents thereof. Among the above methods, the two-stage method is preferred to obtain a uniform urethane resin (I) or (II). When producing the urethane resin (I) or (II) by the two-stage method, the chain extender and / or the terminal blocking agent are preferably reacted so that the total equivalent ratio of the amino groups in the chain extender and / or the terminal blocking agent is 1 / 0.9 to 1.3. If the equivalent ratio of the isocyanate group to the amino group is less than 1 / 1.3, the chain extender and / or the terminal blocking agent may remain unreacted, causing the urethane resin to yellow or emitting an odor after printing. Furthermore, in recent years, from the viewpoint of the working environment, it is more preferable not to use aromatic solvents such as toluene and xylene, or ketone solvents. Chain extenders used in the polyurethane resin in the liquid ink composition of this embodiment include ethylenediamine, propylenediamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine, isophoronediamine, dicyclohexylmethane-4,4'-diamine, etc., as well as amines having a hydroxyl group in the molecule, such as 2-hydroxyethylethylenediamine, 2-hydroxyethylpropyldiamine, 2-hydroxyethylpropylenediamine, di-2-hydroxyethylethylenediamine, di-2-hydroxyethylenediamine, di-2-hydroxyethylpropylenediamine, 2-hydroxypropylethylenediamine, di-2-hydroxypropylethylenediamine, and di-2-hydroxypropylethylenediamine. These chain extenders can be used alone or in combination of two or more. Monovalent active hydrogen compounds can also be used as end-capping agents for the purpose of terminating the reaction. Examples of such compounds include monoamines such as diethanolamine, monoethanolamine, aminomethylpropanol, cyclohexylamine, and dibutylamine, and alcohols such as ethanol and isopropyl alcohol. Furthermore, when it is particularly desired to introduce carboxyl groups into the polyurethane resin, amino acids such as glycine and L-alanine can be used as reaction terminators. These end-capping agents can be used alone or in combination.

[0095] (pigment) The pigment used in the liquid ink composition of this embodiment may be either a colored pigment or a white pigment. The pigment is not particularly limited, and examples thereof include organic pigments and inorganic pigments used in general inks, paints, recording agents, etc. In order to particularly exert the excellent effect of the present disclosure of improving storage stability, the pigment is preferably an organic pigment. Examples of organic pigments include condensed polycyclic organic pigments having a cyclic structure containing a benzene ring or a heterocyclic ring, azo pigments, etc. Specific examples of preferred organic pigments are listed below.

[0096] The azo pigment may be any organic pigment having an azo group (-N=N-) in the molecule, and may be any of a soluble azo lake pigment, an insoluble azo pigment, and a condensed azo pigment. Examples of azo pigments include CI Pigment Red 10, CI Pigment Red 11, CI Pigment Red 112, CI Pigment Red 114, CI Pigment Red 119, CI Pigment Red 12, CI Pigment Red 136, CI Pigment Red 14, CI Pigment Red 144, CI Pigment Red 146, CI Pigment Red 147, CI Pigment Red 15, CI Pigment Red 150, and CI Pigment Red 160. 6, CI Pigment Red 164, CI Pigment Red 166, CI Pigment Red 17, CI Pigment Red 170, CI Pigment Red 171, CI Pigment Red 175, CI Pigment Red 176, CI Pigment Red 18, CI Pigment Red 183, CI Pigment Red 184, CI Pigment Red 185, CI Pigment Red 187, CI Pigment Red 188, CI Pigment Red 193, CI Pigment Tread 2, CI Pigment Red 200, CI Pigment Red 208, CI Pigment Red 21, CI Pigment Red 210, CI Pigment Red 211, CI Pigment Red 213, CI Pigment Red 214, CI Pigment Red 22, CI Pigment Red 220, CI Pigment Red 221, CI Pigment Red 23, CI Pigment Red 237, CI Pigment Red 238, CI Pigment Red 239, CI Pigment Red Pigment Red 242, CI Pigment Red 243, CI Pigment Red 245, CI Pigment Red 247, CI Pigment Red 253, CI Pigment Red 256, CI Pigment Red 258, CI Pigment Red 266, CI Pigment Red 268, CI Pigment Red 269, CI Pigment Red 3, CI Pigment Red 31, CI Pigment Red 32, CI Pigment Red 38, CI Pigment Red 4, CIPigment Red 41, CI Pigment Red 48, CI Pigment Red 48:1, CI Pigment Red 48:2, CI Pigment Red 48:3, CI Pigment Red 48:4, CI Pigment Red 49, CI Pigment Red 49:1, CI Pigment Red 49:2, CI Pigment Red 5, CI Pigment Red 50:1, CI Pigment Red 52:1, CI Pigment Red 52:2, CI Pigment Red 53:1, CI Pigment Red 54, CI Pigment Red 55:1, CI Pigment Red 56:1, CI Pigment Red 57:2, CI Pigment Red 58:1, CI Pigment Red 59:2, CI Pigment Red 60:1, CI Pigment Red 61:1, CI Pigment Red 62:1, CI Pigment Red 63:1, CI Pigment Red 64:1, CI Pigment Red 65:1, CI Pigment Red 66:1, CI Pigment Red 67:1, CI Pigment Red 68:1, CI Pigment Red 69:1, CI Pigment Red 70:1, CI Pigment Red 71:1, CI Pigment Red 72:1, CI Pigment Red 73:1, CI Pigment Red 74:1, CI Pigment Red 75:1, CI Pigment Red 76:1, CI Pigment Red 77:1, CI Pigment Red 78:1, CI Pigment Red 79:1, CI Pigment Red 80:1, CI Pigment Red 81:1, CI Pigment Red 82:1, CI Pigment Red 8 Tread 57:1, CI Pigment Red 58, CI Pigment Red 58:4, CI Pigment Red 6, CI Pigment Red 60, CI Pigment Red 60:1, CI Pigment Red 63, CI Pigment Red 63:1, CI Pigment Red 63:2, CI Pigment Red 64:1, CI Pigment Red 68, CI Pigment Red 7, CI Pigment Red 8, CI Pigment Red 9, CI Pigment Red 95, CI Pigment Yellow 1, CI Pigment Yellow Rho 10, CI Pigment Yellow 100, CI Pigment Yellow 104, CI Pigment Yellow 105, CI Pigment Yellow 106, CI Pigment Yellow 111, CI Pigment Yellow 113, CI Pigment Yellow 114, CI Pigment Yellow 116, CI Pigment Yellow 12, CI Pigment Yellow 120, CI Pigment Yellow 124, CI Pigment Yellow 126, CI Pigment Yellow 127, CI Pigment Yellow 128, CI Pigment Pigment Yellow 13, CI Pigment Yellow 130, CI Pigment Yellow 133, CI Pigment Yellow 14, CI Pigment Yellow 15, CI Pigment Yellow 151, CI Pigment Yellow 152, CI Pigment Yellow 154, CI Pigment Yellow 155, CI Pigment Yellow 16, CI Pigment Yellow 165, CI Pigment Yellow 166, CI Pigment Yellow 167, CI Pigment Yellow 168, CI Pigment Yellow 169, CIPigment Yellow 17, CI Pigment Yellow 170, CI Pigment Yellow 172, CI Pigment Yellow 174, CI Pigment Yellow 175, CI Pigment Yellow 176, CI Pigment Yellow 180, CI Pigment Yellow 181, CI Pigment Yellow 183, CI Pigment Yellow 191, CI Pigment Yellow 191:1, CI Pigment Yellow 194, CI Pigment Yellow 2, CI Pigment Yellow 205, CI Pigment Yellow 2 06, CI Pigment Yellow 209, CI Pigment Yellow 212, CI Pigment Yellow 214, CI Pigment Yellow 219, CI Pigment Yellow 3, CI Pigment Yellow 4, CI Pigment Yellow 49, CI Pigment Yellow 5, CI Pigment Yellow 55, CI Pigment Yellow 6, CI Pigment Yellow 60, CI Pigment Yellow 61, CI Pigment Yellow 62, CI Pigment Yellow 63, CI Pigment Yellow 65, CI Pigment Yellow 7, CI Pigment Yellow 73, CI Pigment Yellow 74, CI Pigment Yellow 75, CI Pigment Yellow 77, CI Pigment Yellow 81, CI Pigment Yellow 83, CI Pigment Yellow 87, CI Pigment Yellow 9, CI Pigment Yellow 93, CI Pigment Yellow 94, CI Pigment Yellow 95, CI Pigment Yellow 97, CI Pigment Yellow 98, CI Pigment Orange 1, CI Pigment Orange 13, CI Pigment Pigment Orange 15, CI Pigment Orange 16, CI Pigment Orange 17, CI Pigment Orange 17:1, CI Pigment Orange 19, CI Pigment Orange 2, CI Pigment Orange 22, CI Pigment Orange 24, CI Pigment Orange 3, CI Pigment Orange 34, CI Pigment Orange 36, CI Pigment Orange 38, CI Pigment Orange 4, CI Pigment Orange 46, CI Pigment Orange 5, CI Pigment Orange 60, CIExamples of pigments include CI Pigment Orange 62, CI Pigment Orange 64, CI Pigment Orange 72, CI Pigment Orange 74, CI Pigment Brown 25, CI Pigment Brown 32, CI Pigment Brown 5, CI Pigment Blue 25, CI Pigment Blue 26, CI Pigment Violet 13, CI Pigment Violet 17, CI Pigment Violet 32, and CI Pigment Violet 50. These pigments may be used alone or in combination.

[0097] Of the azo pigments, CI Pigment Red 57:1 (PR57:1), CI Pigment Red 146 (PR146), CI Pigment Yellow 13 (PY13), CI Pigment Yellow 55 (PY55), CI Pigment Yellow 83 (PY83), CI Pigment Yellow 180 (PY180), and CI Pigment Range 13 (PO13) are particularly preferred.

[0098] The primary particle diameter of the azo pigment is, for example, 0.01 to 1.0 μm, preferably 0.1 to 0.6 μm. The specific surface area of ​​the azo pigment is, for example, 10 to 150 m 2 / g, preferably 20 to 100m 2 When the primary particle size and specific surface area are within the above ranges, the pigment can have excellent coloring power and dispersibility.

[0099] Further, the color pigment may also be a fused polycyclic organic pigment. The fused polycyclic organic pigment refers to an organic pigment having a cyclic structure containing a benzene ring or a heterocycle, among other organic pigments. Examples of the fused polycyclic organic pigment used in the present invention include CI Pigment Blue 15, CI Pigment Blue 15:1, CI Pigment Blue 15:2, CI Pigment Blue 15:3, CI Pigment Blue 15:4, CI Pigment Blue 15:5, CI Pigment Blue 15:6, CI Pigment Blue 16, CI Pigment Blue 17, CI Pigment Blue 75, CI Pigment Blue 79, CI Pigment Green 7, and CI Pigment Green 36. Phthalocyanine pigments such as CI Pigment Green 58, CI Pigment Green 59, CI Pigment Green 62, CI Pigment Green 63, CI Pigment Violet 19, CI Pigment Violet 42, CI Pigment Violet 55, CI Pigment Red 122, CI Pigment Red 202, CI Pigment Red 206, CI Pigment Red 207, CI Pigment Red 209, CI Pigment Orange 48, CI Quinacridone pigments such as CI Pigment Orange 49; dioxazine pigments such as CI Pigment Violet 23, CI Pigment Violet 34, CI Pigment Violet 35, CI Pigment Violet 37, and CI Pigment Blue 80; perylene pigments such as CI Pigment Red 123, CI Pigment Red 149, CI Pigment Red 178, CI Pigment Red 179, CI Pigment Red 190, CI Pigment Red 224, CI Pigment Violet 29, CI Pigment Black 31, and CI Pigment Black 32; perinone pigments such as CI Pigment Orange 43 and CI Pigment Red 194; isoindolinone pigments such as CI Pigment Yellow 109, CI Pigment Yellow 110, CI Pigment Yellow 173, CI Pigment Yellow 179, CI Pigment Orange 61, and CI Pigment Brown 38; and CI Pigment Yellow 139.Isoindoline pigments such as CI Pigment Yellow 185, CI Pigment Orange 66, CI Pigment Orange 69, and CI Pigment Red 260; thioindigo pigments such as CI Pigment Red 88, CI Pigment Red 181, CI Pigment Red 279, CI Pigment Violet 36, and CI Pigment Violet 38; CI Pigment Red 83, CI Pigment Red 89, CI Pigment Red 168, CI Pigment Red 177, CI Pigment Red 182, CI Pigment Red 216, CI Pigment Red 226, CI Pigment Red 251, CI Pigment Red 263, CI Pigment Blue 60, CI Pigment Yellow 24, CI Pigment Yellow 99, CI Pigment Yellow 108, CI Pigment Yellow 123, CI Pigment Yellow 199, CI Pigment Violet 31, and CI Pigment Orange 4. Examples of pigments include anthraquinone pigments such as CI Pigment Orange 51, CI Pigment Violet 5:1, and CI Pigment Black 20; quinophthalone pigments such as CI Pigment Yellow 138 and CI Pigment Yellow 231; diketopyrrolopyrrole pigments such as CI Pigment Orange 71, CI Pigment Orange 73, CI Pigment Orange 81, CI Pigment Red 254, CI Pigment Red 255, CI Pigment Red 264, CI Pigment Red 270, and CI Pigment Red 272; and metal complex pigments such as CI Pigment Yellow 117, CI Pigment Yellow 129, CI Pigment Yellow 150, CI Pigment Yellow 153, CI Pigment Orange 65, CI Pigment Orange 68, CI Pigment Red 257, CI Pigment Red 271, CI Pigment Green 8, and CI Pigment Green 10.

[0100] The fused polycyclic organic pigment used in this embodiment may be a commercially available product, or may be manufactured by a known, commonly used method. Of course, after manufacturing, it may be subjected to appropriate known treatments, such as pigment derivative treatment, surfactant treatment, rosin treatment, or resin treatment. Furthermore, the pigment particle size, particle shape, and particle surface charge may be adjusted and controlled for printing inks, paints, colored molded products, stationery, textile printing, toner, color filters, inkjet inks, and cosmetics. When a fused polycyclic organic pigment with a high specific surface area by the BET method is used in an ink, the viscosity of the ink increases, and when the specific surface area is low, the coloring power of the ink decreases. Therefore, the specific surface area of ​​the fused polycyclic organic pigment by the BET method is 20 to 130 m. 2 / g, and 50 to 100m 2 / g range is more preferable.

[0101] Examples of inorganic pigments include white inorganic pigments such as titanium oxide, zinc oxide, zinc sulfide, barium sulfate, calcium carbonate, chromium oxide, silica, lithopone, antimony white, and gypsum. Among inorganic pigments, titanium oxide is particularly preferred. Titanium oxide exhibits a white color and is preferred in terms of coloring power, hiding power, chemical resistance, and weather resistance. From the viewpoint of printing performance, titanium oxide that has been treated with silica and / or alumina is preferred.

[0102] Examples of inorganic pigments other than white include carbon black, aluminum particles, mica, bronze powder, chrome vermilion, yellow lead, cadmium yellow, cadmium red, ultramarine, Prussian blue, red iron oxide, yellow iron oxide, iron black, and zircon. Aluminum is in powder or paste form, but it is preferably used in paste form from the standpoints of handleability and safety, and whether leafing or non-leafing aluminum is used is selected appropriately from the standpoints of brightness and concentration.

[0103] The carbon black may be commercially available, and there are no particular limitations on the carbon black that can be used. Commercially available carbon blacks may be used, including oil furnace black, gas furnace black, channel black, and acetylene black, all of which are manufactured by the contact method, furnace method, thermal method, etc. The particle size of the carbon black is, for example, 5 to 200 nm, preferably 20 to 50 nm. The nitrogen adsorption specific surface area of ​​the carbon black is, for example, 20 to 500 m. 2 / g, preferably 30 to 150m 2 / g. The DBP oil absorption of carbon black is, for example, 20 to 150 cm 3 / 100g, preferably 30-120cm 3 The carbon black has a volatile content of, for example, 0.1 to 10.0%. The carbon black has a pH value of, for example, 1 to 10, preferably 2 to 9.

[0104] Examples of commercially available carbon black include MA7, 8, 11, 77, 100, 100R, 100S, 220, 230, 600, #650, #750, #40, #44B, #44, #45B, #47, #45, #33, #45L, #47, #50, #52, #2700, #2650, #2600, #200, #2350, #2300, #2200, #1000, #990, #980, #970, #960, #950, #900, #850, #32, #30, #25, #20, #10, #5, CF9, #95, and #260 (all manufactured by Mitsubishi Chemical Corporation), and Special Black6, 5, 4A, 4, 101, 550, 350, 250, 100", Printex U, 150T, V, 140V, 140U", PrinteX P, L6, L, G, ES23, ES22, A, 95, 90, 85, 80, 75, 60, 55, 45, 40, 35, 300, 30, 3, 25, 200", Color Black S170, S160, FW2V, FW200, FW2, FW18, FW1 (all manufactured by Orion Engineered Carbons), Black Pearls 1000M, 800, 880, 4630, Monarch 1300, 700, 880, 4630, Regal 330R, 660R, 660, 400R, 415R, 415, MOGUL E, L" (all manufactured by Cabot Corporation), "Raven 7000, 3500, 5250, 5750, 5000ULTRA II, 1255, 1250, 1190, 1000, 1020, 1035, 1100ULTRA, 1170, 1200" (all manufactured by Columbian Chemicals), "SUNBLACK SB200, 210, 220, 230, 240, 250, 260, 270, 280, 300, 305, 320, 400, 410, 600, 700, 705, 710, 715, 720, 725, 805, 900, 910, 935, 960" (all manufactured by Asahi Carbon Co., Ltd.), and Toka Black #8500, #8500F, #7550SB, #7550F" (all manufactured by Tokai Carbon Co., Ltd.).

[0105] <Pigment properties> The pigment used in the liquid ink composition of this embodiment is an organic pigment or inorganic pigment used in the above-mentioned general inks, paints, and recording materials, and has a base adsorption amount per surface area of ​​the pigment of 0.30 μmol / m 2 It is preferable to use the above pigments. The amount of base adsorbed per surface area of ​​the pigment is 0.30 μmol / m 2 The use of the above pigments can improve the dispersion stability of inks using these pigments. Therefore, the problem of reduced pigment dispersibility that occurs in ink systems that do not contain vinyl chloride vinyl acetate copolymer can be alleviated, and therefore it is preferable to use these pigments in combination with ink systems that do not contain vinyl chloride vinyl acetate copolymer. While the reason for this is unclear, one possible reason is that when the base adsorption amount per surface area of ​​the colorant is large, the basic substance in the liquid ink composition or the polar moiety of the binder resin is adsorbed to the pigment surface, resulting in excellent dispersibility of the pigment itself. For example, when polyvinyl butyral is not used in the liquid ink composition of this embodiment, the base adsorption amount per surface area of ​​the pigment is 0.30 μmol / m 2 It is more preferable to use the above pigments. To achieve the above-mentioned effect, the base adsorption amount per surface area of ​​the pigment is 0.30 μmol / m 2 or more, 0.35 μm / m 2 It is preferable that the thickness is 0.40 μm / m or more. 2 More preferably, it is 0.50 μm / m or more. 2 On the other hand, there is no particular upper limit to the amount of base adsorption, but it is preferably 2.00 μmol / m 2 It is preferable that:

[0106] In this embodiment, the base adsorption amount contained in the pigment can be measured, for example, by adding the pigment to a certain amount of a basic solution, allowing the pigment to adsorb the base, then centrifuging the pigment to settle and collecting the supernatant solution, and subtracting the amount of base in the supernatant solution as the amount of unadsorbed base from the amount of base originally added to calculate the base adsorption amount per weight of the pigment. The base adsorption amount per surface area can be calculated by dividing the base adsorption amount per weight by the nitrogen adsorption specific surface area.

[0107] <Preferred embodiment of pigment> The pigment used in the liquid ink composition of this embodiment has a base adsorption amount per surface area of ​​the pigment of 0.3 μmol / m2 as measured by the above-mentioned method. 2 In these cases, commercially available products or those obtained by conventional manufacturing methods can be used as they are. In addition, the base adsorption amount per surface area of ​​the pigment is 0.3 μmol / m 2 A treatment to achieve the above (hereinafter referred to as "base adsorption treatment") may be carried out. An example of the base adsorption treatment is a method of treating the surface of the pigment with an iron salt, etc. The method of treating with an iron salt preferably includes a pigment slurry production step of adding a pigment to a solvent and stirring to obtain a pigment slurry, a pigment surface treatment step of adding an iron compound and an oxidizing agent to the pigment slurry and stirring to treat the surface of the pigment, and a step of filtering the reaction solution, drying the residue, and pulverizing the residue. The solvent used in the base adsorption treatment can be water and / or an organic solvent, and examples of the organic solvent include methanol, ethanol, n-propanol, and i-propanol. Water is particularly preferred from an economical standpoint. The water may be pure water or industrial water, and buffer solutions such as acetate buffer, phosphate buffer, citrate buffer, citrate-phosphate buffer, borate buffer, and tartrate buffer may also be used.

[0108] The amount of the pigment used as the raw material is preferably 1 to 30 parts by mass relative to 100 parts by mass of the solvent used in the base adsorption treatment. If the amount is too small, productivity will be low, while if the amount is too large, the pigment slurry will become highly viscous and excessive energy will be required for stirring. Therefore, the amount is more preferably 2 to 20 parts by mass, and particularly preferably 3 to 12 parts by mass.

[0109] Examples of iron compounds that can be used include iron sulfate, iron chloride, iron fluoride, iron bromide, iron iodide, iron nitrate, iron phosphate, iron borate, iron carbonate, and iron acetate. From the viewpoint of economy, iron sulfate, iron chloride, and iron nitrate are preferred. Divalent or trivalent iron can be used as the iron. The iron compound may be anhydrous or hydrated.

[0110] The temperature in the pigment slurry production step is preferably 0°C to 100°C. The temperature in the pigment surface treatment step is preferably 0°C to 100°C, and is more preferably 10°C to 90°C, and particularly preferably 20°C to 80°C, because the reaction rate of the pigment surface treatment reaction is slow at low temperatures and the decomposition of hydrogen peroxide is accelerated at high temperatures. The reaction time for the pigment surface treatment step is preferably 10 minutes to 2 hours. The pH of the treatment liquid in the pigment surface treatment step is preferably 1 to 7, since iron ions precipitate when the treatment liquid is alkaline.

[0111] Examples of the oxidizing agent that can be used include hydrogen peroxide, permanganate, hypochlorous acid, chlorous acid, chloric acid, perchloric acid, peroxodisulfate, chromic acid, dichromate, and ozone. Among these, hydrogen peroxide diluted with water to a concentration of 20 to 50% by mass is preferred. The amount of oxidizing agent used may vary depending on the concentration, provided it is an amount suitable for the oxidation reaction, but is typically 10 to 100 parts by mass, and preferably 20 to 80 parts by mass, per 100 parts by mass of the pigment. The iron compound is preferably added in an amount of 1 to 30% by mass, more preferably 2 to 15% by mass, based on the raw material pigment.

[0112] The iron compound and the oxidizing agent may be added to the pigment slurry simultaneously or separately. When added simultaneously, the iron compound and the oxidizing agent may be mixed together before addition. When added separately, the iron compound may be added first, or the oxidizing agent may be added first. Furthermore, the oxidizing agent may be added dropwise or all at once.

[0113] The pigment obtained by the above treatment has polar groups formed on the surface of the pigment, and the amount of base adsorption per surface area of ​​the pigment is 0.3 μmol / m 2 It is presumed that the treated pigment particle surfaces have increased hydrophilicity compared to untreated pigments, which increases wettability with solvents, resulting in faster wetting and superior dispersibility.

[0114] The surface-treated pigment preferably contains 200 ppm or more of iron element per 100 parts by mass of pigment, preferably 230 ppm or more, more preferably 500 ppm or more, and even more preferably 1000 ppm or more. There is no particular upper limit to the amount of iron element contained in the pigment, but it preferably contains 20,000 ppm or less of iron element per 100 parts by mass, more preferably 18,000 ppm or less, and even more preferably 15,000 ppm or less. More specifically, when an azo pigment is used, it preferably contains 200 ppm or more of iron element per 100 parts by mass of azo pigment, preferably 500 ppm or more, more preferably 1000 ppm or more, and even more preferably 3,000 ppm or more. On the other hand, it preferably contains 20,000 ppm or less of iron element per 100 parts by mass of azo pigment, more preferably 18,000 ppm or less, and even more preferably 15,000 ppm or less. When carbon black is used, the iron content is preferably 200 ppm or more, more preferably 500 ppm or more, more preferably 1000 ppm or more, and even more preferably 3000 ppm or more per 100 parts by mass of carbon black, while the iron content is preferably 20000 ppm or less, more preferably 18000 ppm or less, and even more preferably 15000 ppm or less per 100 parts by mass of carbon black.

[0115] The iron element is not limited to simple iron (Fe) but may be in the form of an iron compound such as iron oxide (FeO, Fe2O3, etc.) or iron hydroxide (Fe(OH)2, Fe(OH)3, etc.). The content of the iron element described above can be measured as the amount of iron element even in the case of such iron compounds. The amount of iron element contained in the pigment can be measured using an energy dispersive X-ray fluorescence analyzer PANalytical Epsilon5 (manufactured by Spectris Inc.).

[0116] In the liquid ink composition of this embodiment, the content of the pigment is preferably an amount sufficient to ensure the concentration and coloring power of the liquid ink composition, i.e., the content of the pigment is preferably 1 to 70 mass % and more preferably 5 to 60 mass % relative to the total amount of the liquid ink composition (100 mass %). The mass ratio of the solid content in the liquid ink composition is preferably 10 to 80 mass % relative to the total amount of all solids in the ink composition. The pigments can be used alone or in combination of two or more types. When two or more types are used in combination, the base adsorption amount per surface area of ​​at least one pigment is 0.30 μmol / m 2 Anything above that is fine. Furthermore, when the liquid ink composition of this embodiment contains polyvinyl butyral, from the viewpoint of the dispersibility of the polyvinyl butyral and the combination with the urethane resin component of this embodiment, the amount of base adsorption per surface area is set to 0.30 μmol / m 2 Less than 1000 ppm of pigment can be used.

[0117] (other resins) In addition to the urethane resin (I) and, optionally, the urethane resin component or urethane resin (II), the liquid ink composition of this embodiment may contain other resins that are compatible with ink technology. The other resins may be binder resins or dispersing resins, but are preferably added as binder resins. Examples of other resins that can be used in combination include ethylene-vinyl acetate copolymer resins, vinyl acetate resins, polyamide resins, acrylic resins, polyester resins, alkyd resins, rosin-based resins, rosin-modified maleic acid resins, polyvinyl butyral-based resins, cellulose-based resins, ketone resins, cyclized rubbers, petroleum resins, and polyurethane resins other than the urethane resins (I) and (II). Among these, it is preferable to include at least one resin selected from polyester resins, acrylic resins, polyamide resins, and rosin-modified maleic acid resins, as this can improve blocking resistance and resolubility. In another aspect, the liquid ink composition of the present embodiment preferably further contains at least one resin selected from the group consisting of the urethane resin (II), polyvinyl butyral resin, maleic acid resin, cellulose resin, polyester resin, acrylic resin, and polyamide resin. Furthermore, from the viewpoint of reducing the environmental impact, it is preferable that the ink composition of the present disclosure does not contain a chlorine-based resin. These resins can be used alone or in combination of two or more. The content of the co-used resin is preferably 0.1 to 25% by mass, more preferably 2 to 15% by mass, based on the total mass of the ink. The polyester resin, the acrylic resin, and the polyamide resin are not particularly limited, and known resins can be used.

[0118] <Polyvinyl butyral resin> The liquid ink composition of this embodiment preferably further contains a polyvinyl butyral resin as a binder resin. This polyvinyl butyral resin has the binding and dispersing properties of a binder resin, and because its constituent elements are only carbon, hydrogen, and oxygen atoms, it is more environmentally friendly than vinyl chloride-vinyl acetate copolymer resins. Furthermore, when the liquid ink composition contains a pigment, dispersing the pigment by grinding with a polyvinyl butyral resin results in the adsorption of a suitable group (butyral group, polyvinyl alcohol residue, or vinyl acetate residue) onto the pigment, and the bulky butyral group creates steric hindrance. Therefore, using a combination of urethane resin (I) and a polyvinyl butyral resin provides better dispersion stability than dispersing the pigment with urethane resin (I) alone. The polyvinyl butyral resin of this embodiment is not particularly limited and may be a known resin. Generally, the polyvinyl butyral resin may be a reaction product obtained by acetalizing polyvinyl alcohol with an aldehyde compound such as butyraldehyde by a known reaction. The polyvinyl butyral resin of this embodiment is represented by the following general formula (3): [ka] (In the above general formula (3), n4 and n5 each independently represent an integer of 1 or more, and R 6 represents a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms. In the above general formula (3), R 6 preferably represents a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms, more preferably a hydrogen atom or a hydrocarbon group having 1 to 7 carbon atoms, and even more preferably a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms. The hydrocarbon group may be an alkyl group, an alkenyl group, an aryl group, or an aralkyl group, and may be linear, branched, or cyclic. Among these, an alkyl group is preferred. 6 is more preferably a propyl group or an isopropyl group. As described above, the polyvinyl butyral resin of the present embodiment is a resin made by reacting polyvinyl alcohol and an aldehyde compound as raw materials. 6 When represented as -C(=O)H, R in the general formula (4) 6 is a hydrocarbon group derived from an aldehyde compound used in synthesizing polyvinyl butyral resins.

[0119] A suitable polyvinyl butyral-based resin in this embodiment is preferably a resin having a partial structure represented by the above general formula (3), a partial structure represented by the following general formula (4), and a partial structure represented by the following general formula (5). [ka] (In the above general formula (4), n6 is independently an integer of 1 or more, and R 7 represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms. [ka] (In the above general formula (5), each n7 is independently an integer of 1 or more.)

[0120] In the above general formula (4), R 7 preferably represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, more preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. In addition, the above R 7 is, for example, more preferably a hydrogen atom, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group or a tert-butyl group. Furthermore, when the polyvinyl butyral-based resin of this embodiment is represented by a resin having a partial structure represented by the above general formula (3), a partial structure represented by the following general formula (4), and a partial structure represented by the above general formula (5), the content of the partial structure represented by the above general formula (4) relative to the total amount of the polyvinyl butyral-based resin is preferably 12 mass% or less, more preferably 8 mass% or less, and even more preferably 5 mass% or less. Thus, by setting the content of the partial structure represented by the above general formula (4) in the polyvinyl butyral-based resin within the above range, an ink layer with an excellent balance between fluidity and dispersibility can be obtained.

[0121] The weight-average molecular weight of the polyvinyl butyral-based resin of this embodiment is preferably 5,000 to 150,000, more preferably 6,000 to 100,000, and even more preferably 7,000 to 50,000. By setting the weight-average molecular weight of the polyvinyl butyral-based resin within the above range, excellent curing properties can be achieved, and the coating film can have both strength and appropriate flexibility. Furthermore, polyvinyl butyral-based resins with a weight-average molecular weight of 5,000 to 150,000 are easily available, and the use of such polyvinyl butyral-based resins makes it possible to obtain an ink layer with an excellent balance of fluidity and dispersibility.

[0122] The glass transition temperature (hereinafter, sometimes referred to as Tg) of the polyvinyl butyral resin of this embodiment is preferably in the range of 50° C. to 120° C., more preferably in the range of 55° C. to 115° C., and more preferably in the range of 60 to 110° C. In the present invention, the glass transition temperature is obtained by measurement using a differential scanning calorimeter.

[0123] The hydroxyl value of the polyvinyl butyral resin in this embodiment is preferably in the range of 10 to 40% by mass, and more preferably 15 to 30% by mass. By setting the hydroxyl value of the polyvinyl butyral resin in this range, an ink layer with an excellent balance between fluidity and dispersibility can be obtained. The amount of hydroxyl groups refers to the amount of the partial structure represented by the general formula (5) relative to the total amount of the polyvinyl butyral resin.

[0124] The amount of acetyl groups in the polyvinyl butyral resin is preferably 8% by mass or less, and more preferably 5% by mass or less. By adjusting the amount of acetyl groups in the polyvinyl butyral resin to fall within this range, an ink layer with an excellent balance between fluidity and dispersibility can be obtained. The amount of acetyl groups is determined by the ratio of R 7 is a methyl group, the partial structure is called an acetyl group, and the amount of the acetyl group is the content relative to the total amount of the polyvinyl butyral resin.

[0125] The content (solids) of polyvinyl butyral resins is preferably 0.1 to 5% by mass, more preferably 0.1 to 4.0% by mass, and most preferably 0.2 to 3.0% by mass, based on the total resin solids (100% by mass) of the ink composition. Adding a total of 0.1% by mass or more of polyvinyl butyral resins tends to maintain the adhesion and transferability of the ink film, while keeping the total content 5% by mass or less can maintain the lamination strength of the ink. The lower limit of the solids mass ratio in the ink composition is preferably 0.1% by mass or more, more preferably 0.2% by mass or more, and most preferably 0.3% by mass. The upper limit of the solids mass ratio in the ink is preferably 45% by mass or less, more preferably 40% by mass, even more preferably 30% by mass, even more preferably 20% by mass, even more preferably 15% by mass, and particularly preferably 10% by mass.

[0126] <Maleic acid resin> The maleic acid resin of this embodiment is preferably a rosin-modified maleic acid resin. The rosin-modified maleic acid resin is an alkyd resin obtained by reacting a polyhydric alcohol such as glycerin, pentaerythritol, or ethylene glycol with an adduct of rosin and maleic acid obtained by Diels-Alder reaction. The acid value is determined by the blending ratio of the polyhydric alcohol reacted with the adduct of rosin and maleic acid and the degree of esterification. Furthermore, a polybasic acid may also be used in combination with the polyhydric alcohol to form a structure in which a long-chain alkyd resin is bonded to the rosin skeleton.

[0127] Examples of polyhydric alcohols to be reacted with the adduct of rosin and maleic acid include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, trimethylolpropane, glycerin, pentaerythritol, sorbitol, etc. Examples of polybasic acids to be used together with these polyhydric alcohols as raw materials for alkyd resins include phthalic anhydride, terephthalic acid, isophthalic acid, adipic acid, maleic acid, itaconic acid, succinic acid, sebacic acid, etc.

[0128] Furthermore, for example, a compound having a carbon-carbon unsaturated double bond, such as maleic acid, may be used as a raw material for the alkyd resin, and a styrene-based monomer may be reacted with this to produce a rosin-modified styrene-maleic acid resin, which is also included in the rosin-modified maleic acid resin.

[0129] <Cellulose-based resin> Examples of the cellulose-based resin include cellulose ester resins such as cellulose acetate propionate, cellulose acetate butyrate, and other cellulose ester resins; nitrocellulose (also called soluble cellulose); hydroxyalkyl cellulose; and carboxyalkyl cellulose. The cellulose ester resin preferably has an alkyl group, and examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a pentyl group, and a hexyl group, and the alkyl group may further have a substituent. Of the above, the cellulose-based resins are preferably cellulose acetate propionate, cellulose acetate butyrate, and nitrocellulose, with cellulose acetate propionate and cellulose acetate butyrate being particularly preferred. The weight-average molecular weight is preferably 5,000 to 200,000, more preferably 10,000 to 50,000. Furthermore, the glass transition temperature is more preferably 120°C to 180°C. When used in combination with the polyurethane resin of the present invention, improvements in blocking resistance, scratch resistance, and other physical properties of the ink film can be expected. Nitrocellulose (nitrocellulose) is preferably obtained as a nitric acid ester by reacting natural cellulose with nitric acid to replace three hydroxyl groups in the six-membered ring of the anhydroglucopyranose group in the natural cellulose with nitric acid groups.

[0130] The content (solid content) of the cellulose-based resin is preferably 0.1 to 5 mass% relative to the total resin solid content (100 mass%) of the ink composition, more preferably 0.1 to 4.0 mass%, and most preferably 0.2 to 3.0 mass%. By setting the content of the cellulose-based resin in the range of 0.3 to 3.0 mass%, blocking resistance can be achieved.

[0131] <Chlorine-based resin> In the liquid ink composition of this embodiment, the content of chlorine-based resin (or chlorine-containing resin), for example, vinyl chloride-vinyl acetate copolymer resin (solid content) is preferably less than 4.5 mass % of the total liquid ink composition (solid content), more preferably less than 2.5 mass %, even more preferably less than 1.2 mass %, and even more preferably less than 0.5 mass %. Similarly, the content of the hydroxyl group-containing vinyl chloride / vinyl acetate copolymer resin (solid content) of the entire liquid ink composition (solid content) is preferably less than 4.5 mass%, more preferably less than 2.5 mass%, even more preferably less than 1.2 mass%, and even more preferably less than 0.5 mass%. This makes it possible to provide an environmentally friendly ink that is free of chlorine-based resins, thereby reducing the environmental impact. In inks currently used in lamination, a combination of polyurethane resin and chlorine-based resin such as vinyl chloride-vinyl acetate copolymer resin is widely used as a binder resin combination that can achieve both excellent dispersibility and high film properties. The combination of chlorine-based resin and polyurethane resin is particularly effective for achieving good printability and the various properties required of lamination inks (adhesion to substrates, lamination strength, and boiling retort suitability). However, when emphasizing the provision of environmentally friendly inks, it becomes necessary to eliminate chlorine-based resins such as vinyl chloride-vinyl acetate copolymer resin. However, when chlorine-based resins such as vinyl chloride-vinyl acetate copolymer resin are used in amounts less than the required amount or are not used at all, a decrease in extrusion lamination strength becomes an issue. However, in the present disclosure, it has been confirmed that by combining a specific urethane resin (I) with a urethane bond concentration of a urethane resin component containing the urethane resin (I), or with other binder resins, it is possible to impart sufficient extrusion lamination strength to an ink even with a chlorine-based resin-free binder resin composition such as vinyl chloride-vinyl acetate copolymer. In this embodiment, the liquid ink composition contains at least a binder resin containing a urethane resin component and an organic solvent, and the chlorine content of the binder resin is preferably 5% by mass or less, more preferably 1% by mass or less, and even more preferably 0% by mass. This makes it possible to provide environmentally friendly inks that are free of chlorine-based resins. The vinyl chloride-vinyl acetate copolymer resin is a copolymer of vinyl chloride monomer and vinyl acetate monomer. Therefore, the vinyl chloride-vinyl acetate copolymer resin contains vinyl chloride monomer units and vinyl acetate monomer units. Furthermore, the vinyl chloride-vinyl acetate copolymer resin may contain units of a monomer (another monomer) other than the vinyl chloride monomer units and the vinyl acetate monomer units, as needed. The other monomer is not particularly limited as long as it is copolymerizable with vinyl chloride and vinyl acetate.

[0132] (additives) The liquid ink composition of the present embodiment preferably further contains, as necessary, one or more selected from the group consisting of silica, amide wax, dispersants, antifoaming agents, extender pigments, pigment dispersants, leveling agents, antifoaming agents, waxes, dispersants, plasticizers, infrared absorbers, ultraviolet absorbers, fragrances, and flame retardants. In the liquid ink composition of this embodiment, the content of the additives (solid content) relative to the total amount of the ink composition is preferably 0.1 to 20.0 mass %.

[0133] The liquid ink composition of this embodiment may further contain a dispersant, if necessary. To stably disperse the pigment in an organic solvent, a resin alone can be used, but a dispersant can also be used to further stabilize the pigment. Examples of dispersants include anionic, nonionic, cationic, and amphoteric surfactants. Examples include comb-structured polymers in which polyethyleneimine is polyester-added, or alkylamine derivatives of α-olefin maleic acid polymers. Specific examples include the Solsperse series (ZENECA), the Ajisper series (Ajinomoto), and the Homogenol series (Kao). The BYK series (BYK-Chemie) and the EFKA series (EFKA) can also be used. From the perspective of ink storage stability, the dispersant content in the ink is preferably 0.05% by mass or more of the total ink composition, and from the perspective of lamination suitability, it is preferably 5% by mass or less, more preferably 0.1 to 2% by mass.

[0134] (Method for producing liquid ink composition) The liquid ink composition of this embodiment can be produced by dissolving and / or dispersing a resin, a pigment, etc. in an organic solvent. Specifically, a pigment dispersion is produced by dispersing a pigment in an organic solvent using a polyvinyl butyral resin, and the ink can be produced by blending the resulting pigment dispersion with other compounds, resins, etc. The pigment may be dispersed using a urethane resin component, other resins, or a dispersant, but it is preferable to disperse the pigment using a polyvinyl butyral resin, etc.

[0135] The particle size distribution of the pigment in the pigment dispersion can be adjusted by appropriately adjusting the size of the grinding media of the disperser, the packing ratio of the grinding media, the dispersion treatment time, the discharge speed of the pigment dispersion, the viscosity of the pigment dispersion, etc. As the disperser, commonly used ones such as a roller mill, a ball mill, a pebble mill, an attritor, a sand mill, etc. can be used. If the ink contains air bubbles or unexpectedly large particles, these will degrade the quality of the printed matter, so it is preferable to remove them by filtration, etc. Any conventional filter can be used.

[0136] The viscosity of the ink composition produced by the above method is preferably in the range of 10 mPa·s or more from the viewpoint of preventing sedimentation of the pigment and adequately dispersing it, and 1000 mPa·s or less from the viewpoint of workability during ink production and printing. The above viscosity is measured at 25°C using a Tokimec B-type viscometer. The viscosity of the ink composition can be adjusted by appropriately selecting the types and amounts of raw materials used, such as urethane resin (I), urethane resin (II), binder resins other than urethane resins (I) and (II) (e.g., polyvinyl butyral resins), pigments, organic solvents, etc. The viscosity of the ink can also be adjusted by adjusting the particle size and particle size distribution of the pigment in the ink.

[0137] The hues of the liquid ink composition of this embodiment are determined depending on the type of pigment used. Five process basic colors are available: yellow, crimson, indigo, black, and white. Three process gamut colors are available: red (orange), grass green, and purple. Other base colors available include transparent yellow, peony, vermilion, brown, gold, silver, pearl, and a nearly transparent medium (containing an extender pigment, if necessary) for adjusting color density. For boiling retort inks, the pigments are appropriately selected taking into consideration their migration properties and heat resistance.

[0138] (Printed material) The liquid ink composition of this embodiment can be printed to form a printed matter. The printing method can be a printing method using a known printing plate such as gravure printing or flexographic printing, but gravure printing is particularly preferred. The cylinder used for gravure printing is a known type such as an engraved type or an etched type. The layer on which the desired pattern is formed using the liquid ink composition of this embodiment is referred to as the "printed layer." The printed layer may be a single layer, or there may be multiple printed layers. When there are multiple printed layers, the ink composition used for each printed layer may be the same, may be the same composition but with different pigments, or may be different compositions. When there are multiple printed layers, for example, the printed matter can have a first printed layer formed from a colored ink composition, a second white printed layer formed from a white ink, and a third white printed layer in this order. The first printed layer can form a pattern using a pigment, and the second white printed layer and the third printed layer formed from a white liquid ink can be used as a background for the pattern. When the second or third printed layer is an overprint varnish, it does not need to contain a colorant such as a pigment.

[0139] The base ink is diluted with a diluting solvent to a viscosity and concentration suitable for gravure printing or flexographic printing, and is supplied to each printing unit either alone or in a mixture for printing.

[0140] (Laminated body) The present disclosure may be a laminate having a substrate and a printed layer formed by printing a liquid ink composition on at least a portion of the substrate surface, as long as the printed layer is in direct or indirect contact with the surface of the substrate. Preferable configurations of the laminate of this embodiment include, for example, the following (1) to (4). (1) Base material / adhesive layer / printing layer / base material (2) Base material / adhesive layer / base material / printing layer / adhesive layer / base material (3) Base material / adhesive layer / first printed layer / second printed layer / base material (4) Substrate / adhesive layer / barrier layer / printing layer / adhesive layer / substrate (5) Base material / print layer / adhesive layer / base material However, the laminate of this embodiment is not limited to the above (1) to (4) and may further include an additional substrate. When multiple substrates are included, the substrates may be the same or different. Furthermore, the substrate may be a substrate such as a sealable sealant film or a multilayer film including a sealant layer formed of a heat-sealing agent, and the sealable layer is referred to as a sealant layer. The adhesive layers may have the same composition or different compositions. Furthermore, an anchor coat layer may be sandwiched between the adhesive layers to improve the adhesive strength of the adhesive layers.

[0141] The liquid ink composition of this embodiment is useful for printing on a wide variety of substrates, from general-purpose films to various high-performance films. Usable plastic films are not particularly limited, and examples include films made of polyamide resins such as Ny6, nylon 66, and nylon 46; polyester resins such as polyethylene phthalate (PET), polyethylene naphthalate, polytrimethylene terephthalate, polytrimethylene naphthalate, polybutylene terephthalate, and polybutylene naphthalate; biodegradable resins such as polyhydroxycarboxylic acids such as polylactic acid, and aliphatic polyester resins such as poly(ethylene succinate) and poly(butylene succinate); thermoplastic resins such as polyolefin resins such as polypropylene (PP) and polyethylene, polyimide resins, polyarylate resins, and mixtures thereof; various high-performance films coated with an inorganic or organic barrier coating material on their surfaces; and laminates thereof. Among these, films made of polyester, polyamide, polyethylene, and polypropylene are particularly preferred. These films may be unstretched or stretched films, and the manufacturing method is not limited. They may be multilayer films produced by co-extrusion of resins of each layer, or multilayer sealant films having a sealant layer as the outermost layer of the multilayer film. The thickness of the base film is also not particularly limited, but is usually in the range of 1 to 500 μm.

[0142] The substrate may be formed from a biomass polyolefin. The biomass polyolefin refers to a polyolefin resin using a plant-derived olefin as a raw material monomer. The raw material monomer may contain a petroleum-derived monomer, and may not contain 100% plant-derived monomers. Commercially available biomass polyolefins may also be used. Examples of commercially available products include SGM9450F, SLL118, SLL118 / 21, SLL218, SLL318, SLH118, SLH218, and SLH0820 manufactured by Braskem.

[0143] The substrate used in the laminate of this embodiment may be a substrate in which a vapor-deposited layer made of an inorganic substance and / or an inorganic oxide is provided on the above-mentioned resin film. By using a substrate with such a vapor-deposited layer, it is possible to impart barrier properties to the laminate of this embodiment. The vapor-deposited layer can be formed by a known method using a known inorganic substance or inorganic oxide, and the composition and method of formation are not particularly limited. Furthermore, the laminate may have two or more vapor-deposited films, and these may have the same composition or different compositions.

[0144] The vapor-deposited layer may be, for example, a vapor-deposited film of an inorganic substance or inorganic oxide such as silicon (Si), aluminum (Al), magnesium (Mg), calcium (Ca), potassium (K), tin (Sn), sodium (Na), boron (B), titanium (Ti), lead (Pb), zirconium (Zr), or yttrium (Y). Vapor-deposited films of inorganic oxides such as silicon oxide and aluminum oxide are transparent.

[0145] The inorganic oxides are expressed as MOx (wherein M represents an inorganic element), such as SiOx, AlOx, etc. The value of x can range from 0 to 2 for silicon (Si), 0 to 1.5 for aluminum (Al), 0 to 1 for magnesium (Mg), 0 to 1 for calcium (Ca), 0 to 0.5 for potassium (K), 0 to 2 for tin (Sn), 0 to 0.5 for sodium (Na), 0 to 1.5 for boron (B), 0 to 2 for titanium (Ti), 0 to 1 for lead (Pb), 0 to 2 for zirconium (Zr), and 0 to 1.5 for yttrium (Y). In the above, when x=0, it is a completely inorganic element (pure substance) and is not transparent, and when the value of x is at the upper limit of the range, it indicates that it is completely oxidized. Silicon (Si) or aluminum (Al) is preferably used for the vapor deposition layer, and silicon (Si) with an x ​​value in the range of 1.0 to 2.0 and aluminum (Al) with an x ​​value in the range of 0.5 to 1.5 can be used.

[0146] The vapor deposition layer can be formed on the surface of the substrate or the like by a physical vapor deposition method (PVD method) such as vacuum deposition, sputtering, or ion plating, or a chemical vapor deposition method (CVD method) such as plasma chemical vapor deposition, thermal chemical vapor deposition, or photochemical vapor deposition.

[0147] The thickness of the vapor-deposited layer is not particularly limited as long as the vapor-deposited layer alone can exhibit a certain level of gas barrier function. The preferred thickness range varies depending on the type of metal or metal oxide to be vapor-deposited, but is preferably 0.05 to 70 nm, more preferably 0.1 to 70 nm, more preferably 3 to 70 nm, and even more preferably 5 to 60 nm.

[0148] Examples of the metal-deposited film include VM-CPP film, which is a CPP film that has been vapor-deposited with a metal such as aluminum, and VM-OPP film, which is an OPP film that has been vapor-deposited with a metal such as aluminum. Examples of the transparent vapor-deposited film include films in which silica or alumina has been vapor-deposited on OPP film, PET film, nylon film, etc. Films in which a coating has been applied to the vapor-deposited layer may also be used for the purpose of protecting the inorganic vapor-deposited layer of silica or alumina.

[0149] Paper can also be used as the substrate. For example, high-quality paper used for printing on packaging materials and packages for cosmetics, beverages, pharmaceuticals, toys, equipment, etc., kraft paper, pure white roll paper, glassine paper, parchment paper, Manila cardboard, white cardboard, coated paper, art paper, imitation paper, thin paper, cardboard, polyethylene-coated paper, various synthetic papers, acid-resistant paper, etc. can be used. In addition, if the printing surface of the substrate is subjected to corona discharge treatment, it is preferable because the adhesion to the substrate can be further improved.

[0150] <Lamination method> The lamination method for producing the laminate of this embodiment is not particularly limited, and examples thereof include dry lamination, wet lamination, non-solvent lamination, extrusion lamination, etc. In this case, the layer located between the substrates is called an adhesive layer.

[0151] Examples of adhesives used in the dry lamination include solvent-based two-component curing adhesives, etc. A "solvent-based" adhesive refers to a form used in a so-called dry lamination method, in which the adhesive is applied to a substrate, heated in an oven or the like to volatilize the organic solvent in the coating, and then bonded to another substrate, and includes a polyisocyanate composition, a polyol composition, and an organic solvent capable of dissolving (diluting) them.

[0152] In the two-component curing adhesive, in consideration of the establishment of a recycling-oriented society that should develop sustainably (sustainability), it is preferable to use plant-derived raw materials (biomass raw materials) as raw materials for the polyisocyanate composition or polyol composition. The environmental load can be reduced by appropriately using biomass raw materials. Examples of biomass raw materials include castor oil-based polyols such as castor oil, dehydrated castor oil, hydrogenated castor oil (a hydrogenated castor oil), and 5-50 mol alkylene oxide adducts of castor oil; aliphatic polybasic acids such as succinic acid, succinic anhydride, glutaric acid, adipic acid, azelaic acid, sebacic acid, and itaconic acid; alkyl esters of these acids; and dimer acids.

[0153] The adhesive using biomass raw materials may be commercially available, such as adhesives listed by the Japan Organics Recycling Association, including, for example, DIC Dry BM (manufactured by DIC Corporation) and Takenate BM (manufactured by Mitsui Chemicals, Inc.).

[0154] The weight of the adhesive layer after drying is 0.1 to 10 g / m 2 It is preferable that the amount is 1 to 6 g / m 2 More preferably, it is 2 to 5 g / m2 The thickness of the adhesive layer is preferably 0.1 to 10 μm, more preferably 1 to 7 μm, and even more preferably 2 to 5 μm.

[0155] Although various adhesives can be used for the adhesive layer, it is preferable to use a pressure-sensitive adhesive. Examples of such pressure-sensitive adhesives include rubber-based adhesives obtained by dissolving polyisobutylene rubber, butyl rubber, or mixtures thereof in organic solvents such as benzene, toluene, xylene, or hexane; or these rubber-based adhesives blended with tackifiers such as abiethylene acid rosin ester, terpene-phenol copolymer, or terpene-indene copolymer; and acrylic-based adhesives obtained by dissolving acrylic copolymers with a glass transition point of 20°C or less, such as 2-ethylhexyl acrylate-n-butyl acrylate copolymer or 2-ethylhexyl acrylate-ethyl acrylate-methyl methacrylate copolymer, in an organic solvent.

[0156] When a material having gas barrier properties is used as the adhesive or the anchor coating agent described below, a laminate film with particularly excellent barrier properties can be obtained. As an adhesive with excellent gas barrier properties, 3 g / m 2 The oxygen barrier property of the cured coating film of the adhesive applied at (solid content) is 300cc / m 2 / day / atm or less, or water vapor barrier property of 120g / m 2 / day. Commercially available products include the "PASLIM" series, such as PASLIM VM001 and PASLIM J350X, manufactured by DIC Corporation, and "Maxieve" manufactured by Mitsubishi Gas Chemical Company, Inc.

[0157] The adhesive layer can also be formed from a thermoplastic resin by a conventionally known method, such as melt extrusion lamination or sand lamination. The liquid ink composition of the present invention is preferably laminated by extrusion lamination or sand lamination, in order to improve the interlayer adhesion strength of the extrusion laminate. Examples of the thermoplastic resin that can be used for the adhesive layer include polyethylene resins such as low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), medium-density polyethylene (MDPE), and high-density polyethylene (HDPE); polypropylene resins such as propylene homopolymers, propylene-α-olefin random copolymers, and propylene-α-olefin block copolymers; norbornene polymers and hydrogenated products thereof, such as norbornene copolymers (COC) obtained by copolymerizing norbornene monomers with olefins such as ethylene; vinyl alicyclic hydrocarbon polymers; and cyclic polyolefin resins such as cyclic conjugated diene polymers. Examples of suitable elastomers include polyethylene-based elastomers such as ethylene-vinyl acetate copolymer (EVA) and ethylene-α-olefin copolymers, polypropylene-based elastomers, and butene-based elastomers; ethylene-based copolymers such as ethylene-methyl methacrylate copolymer (EMMA), ethylene-ethyl acrylate copolymer (EEA), ethylene-methyl acrylate (EMA) copolymer, ethylene-ethyl acrylate-maleic anhydride copolymer (E-EA-MAH), ethylene-acrylic acid copolymer (EAA), and ethylene-methacrylic acid copolymer (EMAA); and ionomers of ethylene-acrylic acid copolymers and ionomers of ethylene-methacrylic acid copolymers. Furthermore, to improve interlayer adhesion, acid-modified polyolefin resins obtained by modifying the above-mentioned polyolefin resins with unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, maleic anhydride, fumaric acid, and itaconic acid can also be used. Furthermore, resins obtained by graft polymerizing or copolymerizing a polyolefin resin with an unsaturated carboxylic acid, an unsaturated carboxylic anhydride, or an ester monomer can also be used. These resins may be used alone or in combination of two or more. It is also preferable to use the polyethylene resin using the above-mentioned biomass-derived ethylene as a monomer unit.

[0158] When the adhesive layer is laminated by extrusion lamination, an anchor coating layer may be provided on the surface of the layer to be laminated by applying an anchor coating agent and drying it. Examples of anchor coating agents include anchor coating agents made from any resin with a heat resistance temperature of 135°C or higher, such as polybutadiene-based resins, urethane resins, polyisocyanate-polyether polyols, polyethyleneimine, vinyl-modified resins, epoxy resins, polyester resins, and alkyl titanates, as well as anchor coating agents obtained by diluting the above adhesives with organic solvents. Among these, polyethyleneimine-based anchor coating agents and anchor coating agents obtained by diluting the above adhesives with organic solvents are preferred. A silane coupling agent may also be used as an additive, and soluble nitrocellulose may also be used to enhance heat resistance.

[0159] (packaging material) The packaging material of this embodiment preferably comprises a laminated laminate containing a printed layer formed from the liquid ink composition, and more preferably comprises a laminated laminate containing the ink composition. For example, the packaging material may be formed by arranging two laminated sheets so that their sealant layers are in contact with each other and sealing them, or by folding a continuous (single) laminated sheet so that its sealant layers are in contact with each other and sealing it, or by arranging the laminated sheet and a thermoplastic resin film so that the sealant layer of the laminated sheet is in contact with the thermoplastic resin film and sealing it. The sealing method is not particularly limited, and may be heat sealing or ultrasonic sealing, or any known method can be used. The packaging material can be suitably used as a packaging body, such as packaging for food products such as Western confectionery, snacks, bread, Japanese confectionery, and seasonings, packaging for medical products such as medicines, bandages, and syringes, and packaging for hygiene products such as dustcloths, masks, and brushes. The printed matter, laminate and packaging materials using these of the present invention are recyclable, and the recycled plastics can be used as recycled plastics. [Example]

[0160] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples. Hereinafter, "parts" and "%" are all based on mass unless otherwise specified. In the present invention, the weight average molecular weight (in terms of polystyrene) was measured by GPC (gel permeation chromatography) using an HLC8220 system manufactured by Tosoh Corporation under the following conditions. Separation columns: four TSKgel GMHHR-N columns manufactured by Tosoh Corporation. Column temperature: 40°C. Mobile phase: tetrahydrofuran manufactured by Wako Pure Chemical Industries, Ltd. Flow rate: 1.0 ml / min. Sample concentration: 1.0 wt %. Sample injection volume: 100 microliters. Detector: differential refractometer. The viscosity was measured at 25°C using a Tokimec B-type viscometer.

[0161] 1. Measurement and evaluation methods used in the examples and comparative examples The ink compositions obtained in the examples and comparative examples described below were evaluated by the following test methods.

[0162] (Hydroxyl value) The hydroxyl value is the number of milligrams of potassium hydroxide required to neutralize acetic acid bonded to hydroxyl groups when 1 g of a sample is acetylated, and was measured in accordance with JIS K 0070.

[0163] (acid number) The acid value is the number of milligrams of potassium hydroxide required to neutralize the free fatty acids, resin acids, etc. contained in 1 g of sample, and was measured in accordance with JIS K 0070.

[0164] (amine value) The amine value is the number of milligrams of potassium hydroxide equivalent to the amount of hydrochloric acid required to neutralize the amino groups contained in 1 g of sample, and was measured in accordance with JIS K 0070. Specifically, 0.5 to 2 g of sample was precisely weighed (sample solid content: Sg). 50 mL of a 60 / 40 (mass ratio) mixed solution of methanol and methyl ethyl ketone was added to dissolve the precisely weighed sample. Bromophenol blue was added to the resulting solution as an indicator, and the resulting solution was titrated with 0.2 mol / L ethanolic hydrochloric acid solution (titer: f). The point at which the color of the solution changed from green to yellow was set as the endpoint, and the titer (A mL) at this point was used to calculate the amine value according to the following formula. (Formula) Amine value = (A × f × 0.2 × 56.108) / S [mgKOH / g]

[0165] ((Cellophane tape) Adhesion) The viscosity of the ink compositions described in the Examples and Comparative Examples was adjusted with ethyl acetate to 16 seconds (25°C) using a Zahn cup #3 (manufactured by Rigo Co., Ltd.), and prints were made using OPP film P2161 (20 μm) manufactured by Toyobo Co., Ltd., using a gravure proofing machine equipped with a gravure plate with a plate depth of 35 μm. After leaving the prints for one day, cellophane tape (manufactured by Nichiban Co., Ltd., 12 mm wide) was applied to the printed surface, and the tape was quickly peeled off, and the appearance of the printed film was visually evaluated on the following three-point scale. ◯: The printed film did not peel off at all. △: 50 to 80% of the printed film remained on the film. ×: 50% or less of the printed film remained on the film.

[0166] (blocking resistance) The viscosity of the ink compositions described in the Examples and Comparative Examples was adjusted with ethyl acetate to 16 seconds (25°C) using a Zahn cup #3 (manufactured by Rigo Co., Ltd.), and the films were superimposed on a printed matter prepared using OPP film P2161 (20 μm) manufactured by Toyobo Co., Ltd., with the printed surface and non-printed surface in contact using a gravure proofing machine equipped with a gravure plate with a plate depth of 35 μm, and the films were then applied under a pressure of 10 kgf / cm 2 After removal, the state of ink transfer to the non-printed surface was visually evaluated on a three-point scale. Good: The amount of ink transferred to the non-printed surface is 0 to 20%, which is good. △: Less than 50% metastasis observed. ×: Less than 80% metastasis observed.

[0167] (Extrusion laminate (PEEL) strength) The viscosity of the ink compositions described in the Examples and Comparative Examples was adjusted with ethyl acetate to 16 seconds (25°C) using a Zahn Cup #3 (manufactured by Rigo Co., Ltd.), and a print was produced using OPP film P2161 (20 μm) manufactured by Toyobo Co., Ltd., using a gravure proofing machine equipped with a gravure plate with a plate depth of 35 μm. A polyethyleneimine-based anchor coating agent was applied to this print at a concentration of 0.1 g / m. 2 After coating, molten polyethylene was laminated to a thickness of 40 μm using an extrusion laminator. After obtaining a laminated product, the laminated film was cut into 15 mm widths and subjected to a 90-degree peel test (measurement of PEEL strength) at a pulling speed of 50 mm / min. ◯: Peel strength is 1.5 to 2.0 N / 15 mm. ◯~△: PEEL strength is 1.0~1.5N / 15mm. △: Peel strength is 0.5 to 1.0 N / 15 mm. ×: Peel strength is less than 0.5 / 15 mm.

[0168] (Appearance evaluation after retort processing) The viscosity of the ink composition described in each Example and Comparative Example was adjusted to 16 seconds (25°C) using a Zahn Cup #3 (manufactured by Rigo Co., Ltd.) with an ethyl acetate / IPA mixed solvent, and a print was produced using a gravure proofing machine equipped with a gravure plate with a plate depth of 35 μm, using PET film E5100 (12 μm) manufactured by Toyobo Co., Ltd. A polyester adhesive was applied to this print at a rate of 3.0 g / m. 2 After coating, a laminated product was obtained using a CPP film (Toray Industries, Toray Industries, Inc., Torayfan ZK93KM, 70 μm thick). The laminated product was then stored in a 40°C thermostatic chamber for three days to obtain a laminate for retort resistance testing. The resulting laminate for retort resistance testing was then molded into a pouch measuring 120 mm x 120 mm, and filled with 70 g of a simulated food product containing vinegar, salad oil, and meat sauce in a weight ratio of 1:1:1. The resulting simulated food-filled pouch was then subjected to steam retort sterilization at 135°C for 30 minutes, after which the degree of peeling of the printed material was evaluated using the following three-point scale. ◯: No peeling. △: Small blister-like peeling is observed. ×: Peeling occurs over the entire surface regardless of size.

[0169] 2. Preparation of Liquid Ink Compositions of Examples and Comparative Examples (2-1) Synthesis of urethane resin (I) (2-1.1) Synthesis of Urethane Resin (I-1) (Synthesis Example 1) A four-neck flask equipped with a stirrer, a thermometer, a reflux condenser, and a nitrogen gas inlet tube was charged with 57.838 parts of neopentyl glycol adipate diol (hydroxyl value: 56.0 mg KOH / g), 8.02 parts of polypropylene glycol (1) (hydroxyl value: 445.0 mg KOH / g), 6.438 parts of hydroxyl-terminated polybutadiene (1) (hydroxyl value: 76.0 mg KOH / g), and 21.653 parts of isophorone diisocyanate, and the mixture was reacted at 90°C for 15 hours under a nitrogen stream to produce a urethane prepolymer having isocyanate groups. 50.1 parts of ethyl acetate was then added to the mixture to form a homogeneous solution of the urethane prepolymer. Next, the urethane prepolymer solution was added to a mixture of 0.101 parts of di-n-butylamine, 5.948 parts of isophoronediamine, 101.35 parts of ethyl acetate, and 81.55 parts of isopropyl alcohol, and the mixture was stirred at 45°C for 5 hours to produce a urethane resin solution (I-1). The resulting urethane resin solution (I-1) had a resin solids concentration of 30% by weight and a urethane bond concentration of 1.301 mmol / g, as calculated by the method described above.

[0170] (2-1.2) Synthesis of Urethane Resin (I-2) (Synthesis Example 2) A four-neck flask equipped with a stirrer, a thermometer, a reflux condenser, and a nitrogen gas inlet tube was charged with 57.848 parts of neopentyl glycol adipate diol (hydroxyl value: 56.0 mg KOH / g), 6.126 parts of polyethylene glycol (1) (hydroxyl value: 558.0 mg KOH / g), 8.335 parts of hydroxyl-terminated polybutadiene (1) (hydroxyl value: 76.0 mg KOH / g), and 21.641 parts of isophorone diisocyanate, and the mixture was reacted at 90°C for 15 hours under a nitrogen stream to produce a urethane prepolymer having isocyanate groups. 50.1 parts of ethyl acetate was then added to the mixture to form a homogeneous solution of the urethane prepolymer. Next, the urethane prepolymer solution was added to a mixture of 0.101 parts of di-n-butylamine, 5.948 parts of isophoronediamine, 101.35 parts of ethyl acetate, and 81.55 parts of isopropyl alcohol, and the mixture was stirred at 45°C for 5 hours to produce a urethane resin solution (I-2). The resulting urethane resin solution (I-2) had a resin solids concentration of 30% by weight and a urethane bond concentration of 1.30 mmol / g, as calculated by the method described above.

[0171] (2-1.3) Synthesis of Urethane Resin (I-3) (Synthesis Example 3) A four-neck flask equipped with a stirrer, a thermometer, a reflux condenser, and a nitrogen gas inlet tube was charged with 57.875 parts of neopentyl glycol adipate diol (hydroxyl value: 56.0 mg KOH / g), 6.194 parts of polyethylene glycol (1) (hydroxyl value: 558.0 mg KOH / g), 8.274 parts of hydroxyl-terminated hydrogenated polybutadiene (2) (hydroxyl value: 69.7 mg KOH / g), and 21.607 parts of isophorone diisocyanate, and the mixture was reacted at 90°C for 15 hours under a nitrogen stream to produce a urethane prepolymer having isocyanate groups. 50.1 parts of ethyl acetate was then added to the mixture to form a homogeneous solution of the urethane prepolymer. Next, the urethane prepolymer solution was added to a mixture of 0.101 parts of di-n-butylamine, 5.948 parts of isophoronediamine, 101.35 parts of ethyl acetate, and 81.55 parts of isopropyl alcohol, and the mixture was stirred at 45°C for 5 hours to produce a urethane resin solution (I-3). The resulting urethane resin solution (I-3) had a resin solids concentration of 30% by weight and a urethane bond concentration of 1.297 mmol / g, as calculated by the method described above.

[0172] (2-1.4) Synthesis of Urethane Resin (I-4) (Synthesis Example 4) A four-neck flask equipped with a stirrer, a thermometer, a reflux condenser, and a nitrogen gas inlet tube was charged with 61.467 parts of neopentyl glycol adipate diol (hydroxyl value: 56.0 mg KOH / g), 6.304 parts of polyethylene glycol (1) (hydroxyl value: 558.0 mg KOH / g), 4.515 parts of hydroxyl-terminated polybutadiene (1) (hydroxyl value: 76.0 mg KOH / g), and 21.664 parts of isophorone diisocyanate, and the mixture was reacted at 90°C for 15 hours under a nitrogen stream to produce a urethane prepolymer having isocyanate groups. 50.1 parts of ethyl acetate was then added to the mixture to form a homogeneous solution of the urethane prepolymer. Next, the urethane prepolymer solution was added to a mixture of 0.101 parts of di-n-butylamine, 5.948 parts of isophoronediamine, 101.35 parts of ethyl acetate, and 81.55 parts of isopropyl alcohol, and the mixture was stirred at 45°C for 5 hours to produce a urethane resin solution (I-4). The resulting urethane resin solution (I-4) had a resin solids concentration of 30% by weight and a urethane bond concentration of 1.302 mmol / g, as calculated by the above method.

[0173] (2-1.5) Synthesis of Urethane Resin (I-5) (Synthesis Example 5) A four-neck flask equipped with a stirrer, a thermometer, a reflux condenser, and a nitrogen gas inlet tube was charged with 60.221 parts of neopentyl glycol adipate diol (hydroxyl value: 56.0 mg KOH / g), 6.377 parts of polyethylene glycol (2) (hydroxyl value: 276.0 mg KOH / g), 8.677 parts of hydroxyl-terminated polybutadiene (1) (hydroxyl value: 76.0 mg KOH / g), and 18.675 parts of isophorone diisocyanate, and the mixture was reacted at 90°C for 15 hours under a nitrogen stream to produce a urethane prepolymer having isocyanate groups. 50.1 parts of ethyl acetate was then added to the mixture to form a homogeneous solution of the urethane prepolymer. Next, the urethane prepolymer solution was added to a mixture of 0.101 parts of di-n-butylamine, 5.948 parts of isophoronediamine, 101.35 parts of ethyl acetate, and 81.55 parts of isopropyl alcohol, and the mixture was stirred at 45°C for 5 hours to produce a urethane resin solution (I-5). The resulting urethane resin solution (I-5) had a resin solids concentration of 30% by weight and a urethane bond concentration of 1.032 mmol / g, as calculated by the method described above.

[0174] (2-1.6) Synthesis of Urethane Resin (I-6) (Synthesis Example 6) A four-neck flask equipped with a stirrer, a thermometer, a reflux condenser, and a nitrogen gas inlet tube was charged with 55.361 parts of neopentyl glycol adipate diol (hydroxyl value: 56.0 mg KOH / g), 9.773 parts of polyethylene glycol (1) (hydroxyl value: 558.0 mg KOH / g), 4.067 parts of hydroxyl-terminated polybutadiene (1) (hydroxyl value: 76.0 mg KOH / g), and 24.750 parts of isophorone diisocyanate, and the mixture was reacted at 90°C for 15 hours under a nitrogen stream to produce a urethane prepolymer having isocyanate groups. 50.1 parts of ethyl acetate was then added to the mixture to form a homogeneous solution of the urethane prepolymer. Next, the urethane prepolymer solution was added to a mixture of 0.101 parts of di-n-butylamine, 5.948 parts of isophoronediamine, 101.35 parts of ethyl acetate, and 81.55 parts of isopropyl alcohol, and the mixture was stirred at 45°C for 5 hours to produce a urethane resin solution (I-6). The resulting urethane resin solution (I-6) had a resin solids concentration of 30% by weight and a urethane bond concentration of 1.580 mmol / g calculated by the above-mentioned method.

[0175] (2-1.7) Synthesis of Urethane Resin (I-7) (Synthesis Example 7) A four-neck flask equipped with a stirrer, a thermometer, a reflux condenser, and a nitrogen gas inlet tube was charged with 49.650 parts of neopentyl glycol adipate diol (hydroxyl value: 56.0 mg KOH / g), 5.808 parts of polyethylene glycol (1) (hydroxyl value: 558.0 mg KOH / g), 16.833 parts of hydroxyl-terminated polybutadiene (1) (hydroxyl value: 76.0 mg KOH / g), and 21.660 parts of isophorone diisocyanate, and the mixture was reacted at 90°C for 15 hours under a nitrogen stream to produce a urethane prepolymer having isocyanate groups. 50.1 parts of ethyl acetate was then added to the mixture to form a homogeneous solution of the urethane prepolymer. Next, the urethane prepolymer solution was added to a mixture of 0.101 parts of di-n-butylamine, 5.948 parts of isophoronediamine, 101.35 parts of ethyl acetate, and 81.55 parts of isopropyl alcohol, and the mixture was stirred at 45°C for 5 hours to produce a urethane resin solution (I-7). The resulting urethane resin solution (I-7) had a resin solids concentration of 30% by weight and a urethane bond concentration of 1.301 mmol / g, as calculated by the above method.

[0176] (2-1.8) Synthesis of Urethane Resin (I-8) (Synthesis Example 8) A four-neck flask equipped with a stirrer, a thermometer, a reflux condenser, and a nitrogen gas inlet tube was charged with 62.053 parts of neopentyl glycol adipate diol (hydroxyl value: 56.0 mg KOH / g), 6.571 parts of polyethylene glycol (1) (hydroxyl value: 73.1 mg KOH / g), 8.941 parts of hydroxyl-terminated polybutadiene (1) (hydroxyl value: 76.0 mg KOH / g), and 16.385 parts of isophorone diisocyanate, and the mixture was reacted at 90°C for 15 hours under a nitrogen stream to produce a urethane prepolymer having isocyanate groups. 50.1 parts of ethyl acetate was then added to the mixture to form a homogeneous solution of the urethane prepolymer. Next, the urethane prepolymer solution was added to a mixture of 0.101 parts of di-n-butylamine, 5.948 parts of isophoronediamine, 101.35 parts of ethyl acetate, and 81.55 parts of isopropyl alcohol, and the mixture was stirred at 45°C for 5 hours to produce a urethane resin solution (I-8). The resulting urethane resin solution (I-8) had a resin solids concentration of 30% by weight and a urethane bond concentration of 0.826 mmol / g, as calculated by the above method.

[0177] (2-1.9) Synthesis of urethane resin (C1) (Comparative Synthesis Example 1) A four-necked flask equipped with a stirrer, thermometer, reflux condenser, and nitrogen gas inlet tube was charged with 57.973 parts of neopentyl glycol adipate diol (hydroxyl value: 56.0 mg KOH / g), 14.492 parts of polyethylene glycol (2) (hydroxyl value: 276.0 mg KOH / g), and 21.490 parts of isophorone diisocyanate. The mixture was reacted for 15 hours at 90 ° C under a nitrogen stream to produce a urethane prepolymer having isocyanate groups. 50.1 parts of ethyl acetate was then added to the mixture to form a homogeneous solution of the urethane prepolymer. The urethane prepolymer solution was then added to a mixture of 0.101 parts of di-n-butylamine, 5.943 parts of isophorone diamine, 101.35 parts of ethyl acetate, and 81.55 parts of isopropyl alcohol. The mixture was stirred and reacted at 45 ° C for 5 hours to obtain a urethane resin solution (C1). The resulting urethane resin solution (C1) had a resin solid concentration of 30% by weight, and a urethane bond concentration of 1.292 mmol / g calculated by the above-mentioned method.

[0178] (2-1.10) Synthesis of urethane resin (C2) (Comparative Synthesis Example 2) A four-neck flask equipped with a stirrer, a thermometer, a reflux condenser, and a nitrogen gas inlet tube was charged with 57.833 parts of polypropylene glycol (2) (hydroxyl value: 56.2 mg KOH / g), 6.124 parts of polyethylene glycol (1) (hydroxyl value: 558.0 mg KOH / g), 8.333 parts of hydroxyl-terminated polybutadiene (1) (hydroxyl value: 76.0 mg KOH / g), and 21.660 parts of isophorone diisocyanate, and the mixture was reacted at 90°C for 15 hours under a nitrogen stream to produce a urethane prepolymer having an isocyanate group. 50.1 parts of ethyl acetate was then added to the mixture to form a homogeneous solution of the urethane prepolymer. Next, the urethane prepolymer solution was added to a mixture of 0.101 parts of di-n-butylamine, 5.948 parts of isophoronediamine, 101.35 parts of ethyl acetate, and 81.55 parts of isopropyl alcohol, and the mixture was stirred and reacted at 45°C for 5 hours to obtain urethane resin solution (C2). The obtained urethane resin solution (C2) had a resin solids concentration of 30% by weight and a urethane bond concentration of 1.301 mmol / g calculated by the above-mentioned method.

[0179] (2-2) Synthesis of urethane resin (II) (2-2.1) Synthesis of Urethane Resin (II-1) (Synthesis Example 9) A four-neck flask equipped with a stirrer, thermometer, reflux condenser, and nitrogen gas inlet tube was charged with 351.5 parts of hydrogenated ketone-aldehyde resin (TEGO® Varipuls SK, number average molecular weight 800, hydroxyl value 325 mg KOH / g, manufactured by EVONIK), 48.5 parts of isophorone diisocyanate, and 400 parts of ethyl acetate, and the mixture was reacted at 90°C for 6 hours under a nitrogen stream to obtain a urethane resin (II-1) with a solids content of 50% and a number average molecular weight of 1700. The urethane bond concentration of the urethane resin (II-1) was 1.26 mmol / g, calculated using the method described above.

[0180] [Table 1]

[0181] Urethane resins (I-1) to (I-8), urethane resins (C1) to (C2), and urethane resin (II-1) were synthesized according to the composition ratios in Table 1 above or in the synthesis examples above. The urethane bond concentrations were then measured by the method described above.

[0182] In addition, the raw materials used in the examples and comparative examples in Tables 1-1 and 1-2 above are shown below. [Polypropylene glycol] Polypropylene glycol (1): NOF Corporation "Uniol D-250" (number average molecular weight 250) Polypropylene glycol (2): NOF Corporation "Uniol D-2000" (number average molecular weight 2000) [Polydiene polyol and / or hydrogenated polydiene polyol] Hydroxyl-terminated polybutadiene (1): NISSO PB G-1000 (number average molecular weight 1400), manufactured by Nippon Soda Co., Ltd. Hydroxyl-terminated hydrogenated polybutadiene (2): NISSO PB GI-1000 (number average molecular weight 1500), manufactured by Nippon Soda Co., Ltd. [Polyethylene glycol] Polyethylene glycol (1): NOF Corporation "PEG#200" (number average molecular weight 200) Polyethylene glycol (2): NOF Corporation "PEG #400" (number average molecular weight 400)

[0183] (2-2) Preparation of liquid ink composition Example 1 A mixture of 15 parts by mass of a polyvinyl butyral resin-containing solution (polyvinyl butyral resin 10% by mass solids content), 10 parts by mass of a phthalocyanine blue pigment (FASTGEN Blue LA5380 manufactured by DIC Corporation), and 35 parts by mass of ethyl acetate was kneaded, and 30.0 parts by mass (30% by mass solids content) of the urethane resin (I-1) obtained above and 10 parts by mass of propyl acetate were added to prepare a blue printing ink composition (1) (hereinafter also referred to as composition (1)) as a liquid ink composition.

[0184] <Examples 2 to 11> Blue printing ink compositions (2) to (11) (hereinafter also referred to as compositions (2) to (11)) were prepared as liquid ink compositions in the same manner as in Example 1 using the compositions and composition ratios shown in Table 2 below. The various evaluations described above were carried out for the compositions (1) to (11) obtained in Examples 1 to 11. Table 2 shows the compositions of the liquid ink compositions and the evaluation results.

[0185] <Comparative Examples 1 and 2> Comparative blue printing ink compositions (1) to (2) (hereinafter also referred to as comparative compositions (1) to (2)) were prepared as liquid ink compositions in the same manner as in Example 1 using the compositions and composition ratios shown in Table 2 below. The various evaluations described above were carried out on the comparative compositions (1) and (2) obtained in the above Comparative Examples 1 and 2. Table 2 shows the compositions of the comparative compositions and the evaluation results.

[0186] Example 12 A mixture of 10 parts by mass of a blue pigment (easily dispersible pigment CI Pigment Blue 15:3 (PB15:3)) and 35 parts by mass of ethyl acetate was kneaded, and 30.0 parts by mass (30% by mass solids content) of the urethane resin (I-1) obtained above and 25 parts by mass of propyl acetate were added to prepare a blue printing ink composition (12) (hereinafter also referred to as composition (12)) as a liquid ink composition. The following pigment was used as the blue pigment (easily dispersible pigment CI Pigment Blue 15:3 (PB15:3)). 373.1 parts of CI Pigment Blue 15:3 (DIC Corporation) wet cake (150 parts pigment) and 500 parts ion-exchanged water were placed in a 2L stainless steel cup and stirred for 15 minutes using a Homodisper 2.5 (Primix Corporation) at 500 rpm. The CI Pigment Blue 15:3 slurry was then transferred to a 5L stainless steel cup, and 2127 parts of ion-exchanged water was added to the slurry. While stirring with a stainless steel anchor blade at 150 rpm, 3.8 parts of iron (II) sulfate heptahydrate (Fujifilm Wako Pure Chemical Industries, Ltd.) were added and dissolved, and the temperature was raised to 60°C. Subsequently, 54 parts of 35% hydrogen peroxide solution (Fujifilm Wako Pure Chemical Industries, Ltd.) was further added, and the mixture was stirred for 2 hours to prepare a mixed slurry. Next, the mixed slurry was filtered through a Nutsche filter, washed with 12 L of warm water at 70°C, and the filtered residue was then air-dried (98°C, 18 hours) using a constant temperature air-blowing dryer WFO-500 (manufactured by Tokyo Rikakikai Co., Ltd.). The resulting pigment mass was pulverized to obtain 150 parts of copper phthalocyanine pigment (PB15:3). The iron content of the pigment was 3530 ppm. The base adsorption amount per surface area of ​​the pigment was 0.57 μmol / m 2 It was. In this example, the amount of iron element contained in the pigment was measured using an energy dispersive X-ray fluorescence analyzer PANalytical Epsilon5 (manufactured by Spectris Inc.). In this example, the amount of base adsorption per surface area of ​​the pigment was measured using the following method. Approximately 100 mg of the pigment was weighed into a 50 mL polyethylene wide-mouth bottle together with 15 mL of the adsorption base solution, and the mixture was mixed and stirred (750 cpm, 15 minutes) using a paint shaker (manufactured by Toyo Seiki Seisakusho Co., Ltd.). The pigment was then centrifuged (3500 g, 20 minutes) using a refrigerated high-speed centrifuge H-2000B (manufactured by Kokusan Co., Ltd.) to settle the pigment, and 10 mL of the supernatant was then collected. This was diluted with 15 mL of n-propyl acetate (manufactured by Kanto Chemical Co., Inc.) and subjected to potentiometric titration with the titration acid solution using an automatic titrator COM-A19 (manufactured by Hiranuma Co., Ltd.) to measure the amount of unadsorbed base present in the supernatant. The amount of unadsorbed base was calculated by subtracting the amount of base added from the amount of unadsorbed base to calculate the amount of base adsorption per weight of the pigment. The amount of base adsorption per surface area of ​​the pigment was calculated by dividing the amount of base adsorption per weight by the nitrogen adsorption specific surface area. The base solution for adsorption was prepared by diluting a 0.1 mol / L tetra-n-butylammonium hydroxide solution (N / 10) (benzene / methanol solution) (manufactured by Kanto Chemical Co., Ltd.) with a known factor value, exactly 1 / 100, with n-propyl acetate (manufactured by Kanto Chemical Co., Ltd.). The acid solution for titration was prepared by dissolving approximately 95 mg of p-toluenesulfonic acid monohydrate (Kanto Chemical Co., Ltd.) in 500 mL of n-propyl acetate (Kanto Chemical Co., Ltd.), and the concentration was titrated with the above-mentioned base solution for adsorption before use.

[0187] <Examples 13 to 22> Blue printing ink compositions (13) to (22) (hereinafter also referred to as compositions (13) to (22)) were prepared as liquid ink compositions in the same manner as in Example 12 using the compositions and composition ratios shown in Table 3 below. The various evaluations described above were carried out for the compositions (13) to (22) obtained in Examples 12 to 22. Table 3 shows the compositions of the liquid ink compositions and the evaluation results.

[0188] <Comparative Examples 3 and 4> Comparative blue printing ink compositions (3) to (4) (hereinafter also referred to as comparative compositions (3) to (4)) were prepared as liquid ink compositions in the same manner as in Example 12 using the compositions and composition ratios shown in Tables 3-1 and 3-2 below. The various evaluations described above were carried out on the comparative compositions (3) and (4) obtained in the above Comparative Examples 3 and 4. Table 3 shows the compositions of the comparative compositions and the evaluation results. The evaluation results in Tables 2 and 3 below confirm that the liquid ink compositions of this example have a better balance of blocking resistance, adhesion, and laminate strength than the comparative compositions, and also suppress the detachment of the ink layer after boiling or retort treatment.

[0189] [Table 2]

[0190] [Table 3]

Claims

1. Contains a urethane resin component and an organic solvent, The urethane resin component comprises a urethane resin (I) produced from reaction raw materials (I) including a first polyol component containing a polydiene polyol and / or a hydrogenated polydiene polyol, a second polyol component containing a polyester polyol (I), and a polyisocyanate compound (I).

2. 2. The liquid ink composition according to claim 1, wherein the urethane bond concentration of the entire urethane resin components is 0.85 mmol / g or more, and the proportion of the urethane resin (I) is the highest among the resin components contained in the liquid ink composition.

3. 3. The liquid ink composition according to claim 1, wherein the urethane resin (I) contains 1 to 20% by mass of structural units derived from the polydiene polyol and / or structural units derived from the hydrogenated polydiene polyol, relative to 100% by mass of the urethane resin (I).

4. 3. The liquid ink composition according to claim 1, wherein a mass ratio of the polydiene polyol and / or hydrogenated polydiene polyol in the first polyol component to the polyester polyol (I) in the second polyol component is 5:95 to 90:

10.

5. The liquid ink composition according to claim 1 or 2, wherein the second polyol component further contains a polyether polyol (I).

6. 3. The liquid ink composition according to claim 1, further comprising at least one resin selected from the group consisting of a urethane resin (II) other than the urethane resin (I), a polyvinyl butyral resin, a maleic acid resin, a cellulose resin, a polyester resin, an acrylic resin, and a polyamide resin.

7. 3. The liquid ink composition according to claim 1, wherein the urethane resin (I) has an amine value of 0 to 10.0 mgKOH / g.

8. 3. The liquid ink composition according to claim 1, wherein the urethane bond concentration of the urethane resin (I) is 0.86 mmol / g or more.

9. 3. The liquid ink composition according to claim 1, wherein the resin component contained in the liquid ink composition has a chlorine content of 5% by mass or less.

10. A printed matter obtained by printing the ink composition according to claim 1 or 2 onto a substrate.

11. A laminate or package comprising the printed matter according to claim 10.

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