Oil-based ink compositions, laminates, and industrial tapes

Abstract

To provide an oil-based ink composition, a laminate using the same, and an industrial tape that can form a coating film with excellent curl resistance, which prevents curling of printed materials even when printed on plastic films less than 10 μm thick, and also has excellent solvent resistance, blocking resistance, and abrasion resistance. [Solution] An oil-based ink composition comprising a urethane-modified (meth)acrylic resin (A), a hydrocarbon wax (B), and an organic solvent (C), wherein (A) is a graft polymer having a (meth)acrylic portion as its main backbone and a urethane portion as its side chain, the mass ratio expressed as urethane portion / (meth)acrylic portion is 0.1 to 0.9, the glass transition temperature of the (meth)acrylic portion is 40 to 100°C, the content of (A) is 13.0 to 72.0% by mass, the penetration of (B) is 20 or less, and the content of (B) is 0.7 to 9.0% by mass.

Description

[Technical Field]

[0001] This invention relates to an oil-based ink composition, a laminate, and an industrial tape. [Background technology]

[0002] Industrial tapes used in electronic components such as smartphones and televisions are printed on plastic films using inks and varnishes, such as gravure printing, for purposes such as improving durability, adding functionality and design, and improving workability.

[0003] Industrial tapes used in electronic components and other applications require thinness from the perspectives of miniaturization, weight reduction, cost reduction, flexibility, and conformability. The plastic films used are considerably thinner than those used in general flexible packaging, often less than 10 μm thick. A problem that arises in this context is the curling of printed materials obtained by printing on plastic films. The thinner the plastic film used, the more likely the printed material is to curl, significantly reducing workability. Therefore, even when using thin plastic films, inks are required to have good curl resistance to prevent curling.

[0004] On the other hand, solvent resistance is another important physical property required for inks used in industrial tapes. Organic solvents are used when cleaning parts and products during the manufacturing process, as well as during maintenance. In such cases, the printed coating on the industrial tape must be resistant to dissolution and must have excellent solvent resistance, preventing deterioration, degradation of physical properties, and changes in appearance. Furthermore, the inks used in industrial tapes are also required to have excellent blocking resistance.

[0005] Patent Document 1 discloses a printing ink composition for shrink packaging containing an acrylic resin having an acid value, a cellulose-based resin esterified with a carboxylic acid, a polyurethane / acrylic copolymer resin, and a solvent. Patent Document 2 discloses an ink composition for transfer sheets containing isocyanate, a hydroxyl group-containing acrylic resin, and a urethane-modified acrylic resin. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2012-207129 [Patent Document 2] Japanese Patent Publication No. 2015-078332 [Overview of the project] [Problems that the invention aims to solve]

[0007] However, the ink compositions described in Patent Documents 1 and 2 are intended for use in shrink packaging and plastic labels, and the plastic films used are thicker than those used in industrial tapes, so curl resistance is not a problem in the first place. Furthermore, the curl resistance of the ink compositions is not considered sufficient. In addition, solvent resistance is not considered sufficient, and further improvements are needed in terms of blocking resistance and abrasion resistance. In other words, an ink composition that simultaneously satisfies all of the following conditions does not yet exist: curl resistance, solvent resistance, blocking resistance, and abrasion resistance.

[0008] The present invention aims to provide an oil-based ink composition, a laminate using the same, and an industrial tape that can form a coating film having excellent curl resistance, which prevents curling of printed materials even when printed on plastic films less than 10 μm thick, and also having excellent solvent resistance, blocking resistance, and abrasion resistance. [Means for solving the problem]

[0009] The present invention has the following aspects. [1] An oil-based ink composition containing a urethane-modified (meth)acrylic resin (A), a hydrocarbon wax (B), and an organic solvent (C), The urethane-modified (meth)acrylic resin (A) is a graft polymer having a (meth)acrylic portion as its main skeleton and urethane portions as its side chains. In the urethane-modified (meth)acrylic resin (A), the mass ratio represented by the urethane portion / (meth)acrylic portion is 0.1 to 0.9. The glass transition temperature of the (meth)acrylic portion constituting the urethane-modified (meth)acrylic resin (A) is 40 to 100°C. The content of the urethane-modified (meth)acrylic resin (A) on a solids basis is 13.0 to 72.0% by mass relative to the total solids of the oil-based ink composition. The penetration of the hydrocarbon wax (B) is 20 or less. An oil-based ink composition in which the content of the hydrocarbon wax (B) on a solid content basis is 0.7 to 9.0% by mass relative to the total solid content of the oil-based ink composition. [2] The oil-based ink composition according to [1], wherein the mass ratio of the urethane portion to the (meth)acrylic portion in the urethane-modified (meth)acrylic resin (A) is 0.1 to 0.5. [3] The oil-based ink composition according to [1] or [2], wherein the hydroxyl value of the urethane-modified (meth)acrylic resin (A) is 40 to 120 mgKOH / g or less. [4] The oil-based ink composition according to any one of [1] to [3], further containing pigment (D). [5] Further containing a hardening agent (E), The oil-based ink composition according to any one of [1] to [4] above, wherein the curing agent (E) comprises one or more selected from hexamethylene diisocyanate, isophorone diisocyanate, m-xylylene diisocyanate, and adducts thereof. [6] An oil-based ink composition according to any of [1] to [5] above, for use in gravure printing. [7] A laminate comprising a plastic film and an ink layer formed on one surface of the plastic film using the oil-based ink composition described in [6]. [8] The laminate according to [7], further comprising a pattern layer between the plastic film and the ink layer or on the other surface of the plastic film. [9] An industrial tape comprising the laminate according to [7] or [8]. [Advantages of the Invention]

[0010] According to the present invention, there is provided an oil-based ink composition that has excellent curl resistance such that curling of the printed matter is unlikely to occur even when printed on a plastic film less than 10 μm thick, and can form a coating film having excellent solvent resistance, blocking resistance, and abrasion resistance, a laminate using the same, and an industrial tape. [Brief Description of the Drawings]

[0011] [Figure 1] It is a cross-sectional view schematically showing an example of the laminate of the present invention. [Figure 2] It is a cross-sectional view schematically showing another example of the laminate of the present invention. [Figure 3] It is a cross-sectional view schematically showing another example of the laminate of the present invention. [Embodiments for Carrying Out the Invention]

[0012] Hereinafter, the present invention will be described in detail. The following embodiments are merely illustrative for explaining the present invention, and it is not intended to limit the present invention only to these embodiments. The present invention can be implemented in various modes without departing from its gist. In the present invention, "oil-based" in the oil-based ink composition means containing an organic solvent as a medium. The proportion of the organic solvent in the medium of the oil-based ink composition is preferably 50% by mass or more, more preferably 70% by mass or more, particularly preferably 90% by mass or more, and may be 10% by mass with respect to the total mass of the medium. A "coating film" refers to a coating film formed by an oil-based ink composition. In particular, the coating film before drying is also called the "coated film," and the coating film after drying is also called the "ink layer." The coated film is obtained by coating the oil-based ink composition of the present invention onto a surface to be coated (for example, a plastic film, etc.). The ink layer is obtained by drying the coated film and removing volatile components such as the medium in the coated film. If necessary, the ink layer obtained after drying the coated film may be aged. "Variable component" refers to volatile components such as water and organic solvents. Specifically, it refers to components other than the solid components listed below (volatile components). The "solid content" of an oil-based ink composition refers to the non-volatile components of the composition, excluding the medium, and is the component that ultimately forms the ink layer. Even if components other than the medium are liquid at room temperature, they are not included in the medium and are included in the solid content. The solid content is measured in accordance with JIS K 5601-1-2:2008. The "total solids" of an oil-based ink composition refers to the total mass (sum) of solids contained in the oil-based ink composition. The content of components other than the medium in the oil-based ink composition is all calculated on a solids basis. "(Meth)acrylic" is a general term for "acrylic" and "methacrylic". "(Meth)acrylate" is a general term for "acrylate" and "methacrylate". "(Meth)acrylonitrile" is a general term for "acrylonitrile" and "methacrylonitrile." The "~" symbol indicating a numerical range means that the numbers before and after it are included as the lower and upper limits, respectively. For example, A~B is equivalent to A or greater and B or less. The lower and upper limits of the numerical ranges disclosed herein can be combined in any way to create new numerical ranges.

[0013] [Oil-based ink composition] The oil-based ink composition of this embodiment contains a urethane-modified (meth)acrylic resin (A), a hydrocarbon wax (B), and an organic solvent (C). The oil-based ink composition may further contain pigment (D). The oil-based ink composition may further contain a curing agent (E). The oil-based ink composition may further contain other components (hereinafter also referred to as "other optional components") other than urethane-modified (meth)acrylic resin (A), hydrocarbon wax (B), organic solvent (C), pigment (D), and curing agent (E), as long as they do not impair the effects of the present invention.

[0014] <Urethane-modified (meth)acrylic resin (A)> Urethane-modified (meth)acrylic resin (A) is a binder resin. The urethane-modified (meth)acrylic resin (A) is a graft polymer having a (meth)acrylic portion as its main skeleton and urethane portions as its side chains. In other words, the main chain, which is the (meth)acrylic portion, and the side chains, which are the urethane portions, are connected by urethane bonds. The urethane-modified (meth)acrylic resin (A) imparts solvent resistance to the coating film by having a (meth)acrylic portion and curl resistance to the coating film by having a urethane portion. Therefore, by including the urethane-modified (meth)acrylic resin (A) in the oil-based ink composition, a coating film with excellent curl resistance and solvent resistance can be obtained.

[0015] Typical examples of the synthesis of urethane-modified (meth)acrylic resin (A) include a method in which a urethane prepolymer having isocyanate groups at its termini is reacted with a (meth)acrylate monomer having hydroxyl groups to synthesize a (meth)acrylate monomer having a urethane portion, and then (meth)acrylic polymerization is carried out using the (meth)acrylate monomer having a urethane portion; and a method in which a (meth)acrylic polymer having hydroxyl groups in its side chains is synthesized by (meth)acrylic polymerization using a (meth)acrylate monomer having hydroxyl groups, and then (meth)acrylic polymer having hydroxyl groups in its side chains is reacted with a urethane prepolymer having isocyanate groups at its termini. Alternatively, urea prepolymer may be used instead of urethane prepolymer.

[0016] Examples of (meth)acrylic monomers constituting the (meth)acrylic portion include (meth)acrylates having hydroxyl groups. Examples of (meth)acrylates having hydroxyl groups include hydroxymethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate. Other monomers having a hydroxyl group besides (meth)acrylate may be used as the (meth)acrylic monomer. Examples include methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, cyclohexyl (meth)acrylate, glycidyl (meth)acrylate, and (meth)acrylic acid. These (meth)acrylic monomers may be used individually or in combination of two or more types.

[0017] Furthermore, polymerizable monomers other than (meth)acrylic monomers (hereinafter also referred to as "other polymerizable monomers") may be used in combination as needed. Other polymerizable monomers are not particularly limited as long as they can copolymerize with (meth)acrylic monomers, but examples include styrene monomers such as styrene, α-methylstyrene, vinyltoluene, and their derivatives; unsaturated carboxylic acid monomers such as itaconic acid, maleic acid, fumaric acid, and crotonic acid; and (meth)acrylamide and (meth)acrylonitrile. Other polymerizable monomers may be used individually or in combination of two or more.

[0018] Methods for synthesizing the urethane prepolymer that constitutes the urethane portion include, for example, a method involving the reaction of a polyisocyanate compound with a polyol compound. Additionally, chain extenders may be used as needed. Urethane prepolymers are reaction products obtained by reacting polyol compounds with polyisocyanate compounds, and are compounds having isocyanate groups at the molecular ends.

[0019] Examples of polyisocyanate compounds include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, m-xylylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,2'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 4,4-diphenyl ether diisocyanate, 2-nitrodiphenyl-4,4-diisocyanate, 2,2-diphenylpropane-4,4-diisocyanate, 3,3-dimethyldiphenylmethane-4,4-diisocyanate, 4,4-diphenylpropane diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate, and naphth. Examples include aromatic diisocyanates such as ethylene-1,4-diisocyanate, naphthylene-1,5-diisocyanate, and 3,3-dimethoxydiphenyl-4,4-diisocyanate; aliphatic diisocyanates such as tetramethylene diisocyanate, hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, and lysine diisocyanate; and alicyclic diisocyanates such as isophorone diisocyanate, norbornane diisocyanate, hydrogenated tolylene diisocyanate, hydrogenated xylylene diisocyanate, and hydrogenated diphenylmethane diisocyanate. These polyisocyanate compounds may be used individually or in combination of two or more.

[0020] Examples of polyol compounds include polyester polyols, polycarbonate polyols, and polyether polyols. Polyol compounds may be used individually or in combination of two or more.

[0021] Examples of polyester polyols include polyester polyols or polyester amide polyols obtained by a dehydration polycondensation reaction between polycarboxylic acids and polyhydric alcohols or secondary to tertiary amines. Specific examples of polycarboxylic acids include succinic acid, adipic acid, sebacic acid, azelaic acid, terephthalic acid, isophthalic acid, orthophthalic acid, hexahydroterephthalic acid, hexahydroisophthalic acid, hexahydroorthophthalic acid, and polycarboxylic acids such as naphthalenedicarboxylic acid and trimellitic acid, as well as their acid esters and acid anhydrides, and one or more of these can be used. Specific examples of polyhydric alcohols include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, neopentyl glycol, 1,8-octanediol, 1,9-nonanediol, diethylene glycol, dipropylene glycol, 1,4-cyclohexanedimethanol, ethylene oxide or propylene oxide adducts of bisphenol A, trimethylolpropane, glycerin, and low molecular weight alcohol compounds such as pentaerythritol; and low molecular weight amino alcohol compounds such as monoethanolamine and diethanolamine. One or more of these can be used. Specific examples of secondary and tertiary amines include low-molecular-weight amine compounds such as hexamethylenediamine, xylylenediamine, and isophoronediamine, and one or more of these can be used.

[0022] Furthermore, examples of polyester polyols include lactone-based polyester polyols obtained by ring-opening polymerization of cyclic ester (lactone) monomers such as ε-caprolactone and γ-valerolactone using low molecular weight alcohol compounds and low molecular weight amino alcohol compounds as initiators.

[0023] Examples of polycarbonate polyols include those obtained by the dehydrochlorination reaction of a low molecular weight alcohol compound with phosgene, and those obtained by the transesterification reaction of a low molecular weight alcohol compound with a diester carbonate. Examples of low-molecular-weight alcohol compounds include those similar to those used in the synthesis of polyester polyols. Examples of diester carbonates include diethylene carbonate, dimethyl carbonate, diethyl carbonate, and diphenyl carbonate.

[0024] Examples of polyether polyols include those obtained by ring-opening polymerization of a cyclic ether using at least one initiator selected from the group consisting of low molecular weight alcohol compounds, low molecular weight amine compounds, low molecular weight amino alcohol compounds, and phenols. Specifically, examples include polyoxyethylene polyols, polyoxypropylene polyols, polytetramethylene ether polyols, and polyoxyethylene polyoxypropylene polyols. Furthermore, as polyether polyols, polyester ether polyols initiated from the aforementioned polyester polyols or polycarbonate polyols can also be mentioned. Examples of low-molecular-weight alcohol compounds, low-molecular-weight amine compounds, and low-molecular-weight amino alcohol compounds include those similar to those used in the synthesis of polyester polyols. Examples of cyclic ethers include alkylene oxides such as ethylene oxide, propylene oxide, butylene oxide, and tetrahydrofuran.

[0025] As a chain elongator, a compound having two or more functional groups (e.g., amino groups, hydroxyl groups, etc.) that can react with isocyanate groups within the molecule can be used. Examples of chain elongators include diamine compounds such as ethylenediamine, 1,3-propylenediamine, 1,4-butylenediamine, hexamethylenediamine, isophoronediamine, and 2-ethylaminoethylamine; polyamine compounds such as diethylenetriamine and triethylenetetramine; low molecular weight diol compounds such as ethylene glycol, propylene glycol, butylene glycol, diethylene glycol, and triethylene glycol; and aminoethylethanolamine and aminopropylethanolamine. These chain extenders may be used individually or in combination of two or more.

[0026] The glass transition temperature of the urethane-modified (meth)acrylic resin (A) is preferably 20 to 80°C, more preferably 30 to 70°C, and particularly preferably 40 to 65°C. If the glass transition temperature of the urethane-modified (meth)acrylic resin (A) is below the lower limit, the solvent resistance, blocking resistance, and heat resistance of the coating film will be slightly reduced. If the glass transition temperature of the urethane-modified (meth)acrylic resin (A) exceeds the upper limit, the curl resistance and adhesion to the substrate of the coating film will be slightly reduced.

[0027] The glass transition temperature of urethane-modified (meth)acrylic resin (A) is measured in accordance with JIS K 7121:2012 as follows: Using a differential scanning calorimeter, 10 mg of urethane-modified (meth)acrylic resin (A) is heated from -100°C to 160°C at a rate of 20°C / min. The glass transition temperature is determined from the intersection point of the baseline and the tangent to the endothermic curve in the resulting curve (DSC curve).

[0028] The glass transition temperature of the (meth)acrylic portion constituting the urethane-modified (meth)acrylic resin (A) is 40 to 100°C, preferably 50 to 90°C, and particularly preferably 65 to 85°C. If the glass transition temperature of the (meth)acrylic portion constituting the urethane-modified (meth)acrylic resin (A) is below the above lower limit, the solvent resistance, blocking resistance, and heat resistance of the coating film will decrease. If the glass transition temperature of the (meth)acrylic portion constituting the urethane-modified (meth)acrylic resin (A) exceeds the above upper limit, the curl resistance and adhesion to the substrate of the coating film will decrease.

[0029] The glass transition temperature of the (meth)acrylic portion constituting the urethane-modified (meth)acrylic resin (A) is determined by using the value disclosed by the manufacturer for commercially available products, and otherwise by measuring as follows: Specifically, the (meth)acrylic portion of the urethane-modified (meth)acrylic resin (A) that has not undergone urethane modification treatment is synthesized, and in accordance with JIS K 7121:2012, the glass transition temperature is determined from the intersection of the baseline and the tangent to the endothermic curve in the curve (DSC curve) obtained by heating 10 mg of the (meth)acrylic portion from -100°C to 160°C at a rate of 20°C / min using a differential scanning calorimeter.

[0030] The glass transition temperature of the urethane portion constituting the urethane-modified (meth)acrylic resin (A) is preferably -50 to 50°C, more preferably -40 to 30°C, and particularly preferably -35 to 15°C. If the glass transition temperature of the urethane portion constituting the urethane-modified (meth)acrylic resin (A) is below the above lower limit, the solvent resistance, blocking resistance, and heat resistance of the coating film will be slightly reduced. If the glass transition temperature of the urethane portion constituting the urethane-modified (meth)acrylic resin (A) exceeds the above upper limit, the curl resistance and adhesion to the substrate of the coating film will be slightly reduced.

[0031] The glass transition temperature of the urethane portion constituting the urethane-modified (meth)acrylic resin (A) is determined by using the value disclosed by the manufacturer for commercially available products, and otherwise by measuring as follows: Specifically, the urethane portion is synthesized by reacting a urethane prepolymer having isocyanate groups at the ends, used in the synthesis of urethane-modified (meth)acrylic resin (A), with methanol. In accordance with JIS K 7121:2012, the glass transition temperature is determined from the intersection of the baseline and the tangent to the endothermic curve in the curve (DSC curve) obtained by heating 10 mg of the urethane portion from -100°C to 160°C at a rate of 20°C / min using a differential scanning calorimeter.

[0032] In urethane-modified (meth)acrylic resin (A), the mass ratio expressed as urethane portion / (meth)acrylic portion (hereinafter also referred to as the "urethane / (meth)acrylic ratio") is 0.1 to 0.9, preferably 0.1 to 0.5, and more preferably 0.2 to 0.4. If the urethane / (meth)acrylic ratio in urethane-modified (meth)acrylic resin (A) is below the above lower limit, the curl resistance and adhesion to the substrate of the coating film will decrease. If the urethane / (meth)acrylic ratio in urethane-modified (meth)acrylic resin (A) exceeds the above upper limit, the solvent resistance, blocking resistance, and heat resistance of the coating film will decrease.

[0033] For urethane-modified (meth)acrylic resin (A), the urethane / (meth)acrylic ratio shall be the value disclosed by the manufacturer for commercially available products. Otherwise, the urethane / (meth)acrylic ratio shall be the mass ratio calculated from the mass of the (meth)acrylic monomer and the mass of the urethane prepolymer used in the synthesis of urethane-modified (meth)acrylic resin (A).

[0034] The hydroxyl value of the urethane-modified (meth)acrylic resin (A) is preferably 40 to 120 mg KOH / g, more preferably 60 to 115 mg KOH / g, and particularly preferably 80 to 110 mg KOH / g. If the hydroxyl value of the urethane-modified (meth)acrylic resin (A) is below the lower limit, the adhesion of the coating film to the substrate, heat resistance, and solvent resistance will be slightly reduced. If the hydroxyl value of the urethane-modified (meth)acrylic resin (A) exceeds the upper limit, the blocking resistance of the coating film and the viscosity stability when the curing agent (E) is added will be slightly reduced.

[0035] The hydroxyl value of urethane-modified (meth)acrylic resin (A) is expressed in milligrams as the amount of potassium hydroxide required to neutralize the acetic acid bonded to the hydroxyl group when 1 g of the non-volatile content of the sample is acetylated, and is measured in accordance with JIS K 0070:1992.

[0036] The acid value of the urethane-modified (meth)acrylic resin (A) is preferably 15 mg KOH / g or less, more preferably 10 mg KOH / g or less, and particularly preferably 7 mg KOH / g or less. It may also be 0 mg KOH / g or more, 0.5 mg KOH / g or more, or 1 mg KOH / g or more. The above upper and lower limits can be combined as appropriate. If the acid value of the urethane-modified (meth)acrylic resin (A) exceeds the above upper limit, the solvent resistance and blocking resistance of the coating film will decrease slightly.

[0037] The acid value of urethane-modified (meth)acrylic resin (A) is expressed in milligrams as the amount of potassium hydroxide required to neutralize acidic groups such as carboxyl groups per gram of non-volatile matter in the sample, and is measured in accordance with JIS K 5601-2-1:1999.

[0038] The weight-average molecular weight of the urethane-modified (meth)acrylic resin (A) is preferably 10,000 to 100,000, more preferably 20,000 to 80,000, and particularly preferably 30,000 to 50,000. If the weight-average molecular weight of the urethane-modified (meth)acrylic resin (A) is below the lower limit, the solvent resistance, blocking resistance, and heat resistance of the coating film will be slightly reduced. If the weight-average molecular weight of the urethane-modified (meth)acrylic resin (A) exceeds the upper limit, the curl resistance and adhesion to the substrate of the coating film will be slightly reduced.

[0039] The weight-average molecular weight of urethane-modified (meth)acrylic resin (A) is the weight-average molecular weight converted to the standard polystyrene molecular weight and is measured by gel permeation chromatography (GPC).

[0040] The solubility parameter of urethane-modified (meth)acrylic resin (A) is 10.0~12.5 (cal / cm³). 3 ) 1 / 2 Preferably, 10.5-12.0 (cal / cm³) 3 ) 1 / 2 More preferably, 11.0~11.8 (cal / cm 3 ) 1 / 2 This is particularly preferable. If the solubility parameter of the urethane-modified (meth)acrylic resin (A) is below the above lower limit, the solvent resistance of the coating film, especially its solvent resistance to ethyl acetate, will be slightly reduced. If the solubility parameter of the urethane-modified (meth)acrylic resin (A) exceeds the above upper limit, the storage stability of the oil-based ink composition will be slightly reduced.

[0041] The solubility parameter (SP value) of urethane-modified (meth)acrylic resin (A) is calculated using the Fedors method. The calculation of the SP value using the Fedors method is described in (Polymer Engineering and Science, February, 1974, Vol. 14, No. 2, pp. 147-154) as Δei (cal / mol) and Δvi (cm 3 The value (per mole) can be used to calculate the following formula. SP value = (ΣΔei / ΣΔvi) 1 / 2

[0042] The urethane-modified (meth)acrylic resin (A) may be one manufactured by a known manufacturing method or a commercially available product. The urethane-modified (meth)acrylic resin (A) may be used alone or in combination of two or more types.

[0043] <Hydrogen wax (B)> The inclusion of hydrocarbon wax (B) in the oil-based ink composition improves the abrasion resistance of the coating film. The hydrocarbon wax (B) may be any conventionally known wax, such as polyolefin wax, Fischer-Tropsch wax, paraffin wax, modified paraffin wax, or microcrystalline wax. Among these, polyolefin wax and Fischer-Tropsch wax are preferred, and polyolefin wax is more preferred. Hydrocarbon wax (B) may be used alone or in combination of two or more types.

[0044] Examples of polyolefin waxes include polyethylene wax and polypropylene wax. Among these, polyethylene wax is preferred. Examples of polyethylene waxes include high-density polymerized polyethylene, low-density polymerized polyethylene, oxidized polyethylene, acid-modified polyethylene, and special monomer-modified polyethylene. Fischer-Tropsch wax is a wax produced using carbon monoxide and hydrogen as raw materials by the Fischer-Tropsch process, and has a nearly saturated, unbranched, linear molecular structure.

[0045] The penetration (hardness) of hydrocarbon wax (B) is 20 or less, preferably 17 or less, more preferably 15 or less, and may also be 1 or more, 3 or more, or 5 or more. The above upper and lower limits can be combined as appropriate. If the penetration of hydrocarbon wax (B) exceeds the above upper limit, the solvent resistance and heat resistance of the coating film will decrease. If the penetration of hydrocarbon wax (B) is below the above lower limit, the curl resistance and abrasion resistance of the coating film will decrease slightly.

[0046] The penetration of hydrocarbon wax (B) is determined in accordance with JIS K 2235:2022. The measurement temperature is 25°C.

[0047] <Organic solvent (C)> Examples of organic solvents (C) include aromatic organic solvents such as toluene and xylene; ketone organic solvents such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; ester organic solvents such as ethyl acetate, n-propyl acetate, isopropyl acetate, and isobutyl acetate; and alcohol organic solvents such as methanol, ethanol, n-propanol, i-propanol, n-butanol, and i-butanol. Organic solvent (C) may be used alone or in combination of two or more types.

[0048] As the organic solvent (C), it is preferable to use a mixed solvent consisting of two or more organic solvents. An example of a preferred combination is a combination of a ketone-based organic solvent and an ester-based organic solvent. Among these, a combination of methyl ethyl ketone and n-propyl acetate is particularly preferred.

[0049] <Pigment (D)> The pigment (D) may be any pigment known as a coloring agent, such as organic pigments or inorganic pigments. Examples of organic pigments include azo pigments such as monoazo and condensed azo; surene pigments such as anthraquinone, perinone, perylene, and thioindigo; phthalocyanine pigments such as phthalocyanine blue and phthalocyanine green; quinacridone pigments; dioxazine pigments; isoindolinone pigments; pyrrolopyrrole pigments; aniline black; and organic fluorescent pigments. Examples of inorganic pigments include natural products such as clay, barite, mica, and talc; ferrocyanides such as Prussian blue and sulfides such as zinc sulfide; sulfates such as barium sulfate; oxides such as chromium oxide, zinc oxide, titanium dioxide, and iron oxide; hydroxides such as aluminum hydroxide; silicates such as calcium silicate and ultramarine; carbonates such as calcium carbonate and magnesium carbonate; carbon such as carbon black and graphite; metal powders such as aluminum powder, bronze powder, and zinc powder; and calcined pigments. Pigment (D) may be used alone or in combination of two or more types.

[0050] For example, when an oil-based ink composition is used to make a white ink, titanium dioxide is preferred as the pigment (D). Titanium dioxide is not particularly limited. For example, it can be produced using either the chlorine method or the sulfuric acid method, and it can have either the anatase or rutile crystal structure. From the viewpoint of printability, the sulfuric acid method is preferred, and from the viewpoint of weather resistance, the rutile crystal structure is preferred. Titanium oxide is preferably surface-treated. Various surface treatment agents can be selected according to the required physical properties. Alumina treatment is preferred from the viewpoint of improving dispersibility and gloss, and silica treatment is preferred from the viewpoint of improving heat resistance and opacity. Titanium oxide may also have metal oxides added to it to suit the required properties. Aluminum oxide and zinc oxide are preferred metal oxides. Titanium dioxide may be used alone or in combination of two or more types.

[0051] For example, when using an oil-based ink composition to make black ink, carbon black is preferred as the pigment (D). For example, when the oil-based ink composition is a blue ink, phthalocyanine blue is preferred as the pigment (D).

[0052] <Hardening agent (E)> Examples of curing agents (E) include isocyanate-based curing agents and blocked isocyanate-based curing agents. Among these, isocyanate-based curing agents are preferred from the viewpoint of mild aging conditions and crosslinking rate. The hardening agent (E) may be used alone or in combination of two or more types.

[0053] Isocyanate-based curing agents are compounds (polyisocyanates) that have two or more isocyanate groups in one molecule. Examples of isocyanate-based curing agents include aromatic diisocyanates such as 4,4'-diphenylmethane diisocyanate (MDI), 2,2'-MDI, 2,4'-MDI, 2,4-tolylene diisocyanate (TDI), 2,6-TDI, m-xylylene diisocyanate (XDI), and 1,4-phenylene diisocyanate; isophorone diisocyanate (IPDI), 1,3-bis(isocyanatomethyl)cyclohexane (hydrogenated XDI), and dicyclohexylmethane-4,4'-diisocyanate. Examples include alicyclic diisocyanates such as hydrogenated MDI and 1-methylcyclohexane-2,4-diisocyanate (hydrogenated TDI); aliphatic diisocyanates such as tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), and 2,4,4-trimethylhexamethylene diisocyanate; and isocyanate prepolymers such as adducts of various diisocyanates, isocyanurates of various diisocyanates, biuret compounds of HDI, and allophanates of HDI. Among these, HDI, IPDI, XDI, or their adducts, isocyanurates, biuretes, and allophanates are preferred from the viewpoint of further improving the curl resistance of the coating film; HDI, IPDI, XDI, or their adducts are more preferred; HDI adducts, IPDI adducts, and XDI adducts are even more preferred; and HDI adducts are particularly preferred. Isocyanate-based curing agents may be used individually or in combination of two or more types.

[0054] Adduct compounds are a general term for isocyanate compounds with two or more functions, obtained by reacting a polyisocyanate having two or more isocyanate groups in one molecule (e.g., diisocyanate) with a low molecular weight active hydrogen-containing compound with two or more functions (e.g., low molecular weight triols such as trimethylolpropane and glycerin). Examples of adduct compounds include reaction products of HDI and trimethylolpropane (TMP), reaction products of XDI and TMP, and reaction products of IPDI and TMP.

[0055] <Other optional components> Other optional components include known additives. Examples of additives include binder resins other than urethane-modified (meth)acrylic resin (A) (hereinafter also referred to as "other binder resins"), defoamers, surfactants, anti-settling agents, UV absorbers, antioxidants, leveling agents, surface tension modifiers, rheology modifiers, light stabilizers, lubricants, dispersants, stabilizers, pH adjusters, fillers, antifungal agents, antistatic agents, metal nanoparticles, magnetic powders, etc. Other optional components may be used individually or in combination of two or more.

[0056] Other binder resins are not particularly limited, but examples include (meth)acrylic resins such as acrylic polyol resins, polyurethane resins, polyolefin resins, and polyester resins. Other binder resins may be used individually or in combination of two or more types.

[0057] When the oil-based ink composition contains pigment (D), it is preferable that the oil-based ink composition further contains a dispersant in order to improve the dispersibility of pigment (D). Furthermore, it is preferable that the oil-based ink composition contains substantially no water. In this specification, "substantially absent" means intentionally omitted.

[0058] <Content of each ingredient> The solid content of urethane-modified (meth)acrylic resin (A) is preferably 9.5 to 31.0% by mass, more preferably 13.0 to 29.0% by mass, and particularly preferably 17.0 to 27.0% by mass, relative to the total mass of the oil-based ink composition. The solid content of urethane-modified (meth)acrylic resin (A) is 13.0 to 72.0% by mass, preferably 18.0 to 70.0% by mass, and more preferably 22.0 to 68.0% by mass, relative to the total solid content of the oil-based ink composition. If the content of urethane-modified (meth)acrylic resin (A) is below the lower limit, the curl resistance, solvent resistance, abrasion resistance, adhesion to the substrate, and printability of the oil-based ink composition of the coating film will decrease. If the content of urethane-modified (meth)acrylic resin (A) exceeds the upper limit, the blocking resistance of the coating film will decrease.

[0059] The solid content of urethane-modified (meth)acrylic resin (A) is preferably 60% by mass or more, more preferably 70% by mass or more, and particularly preferably 80% by mass or more, relative to the total solid content of the binder resin. It may also be 100% by mass or less, 95% by mass or less, or 90% by mass or less. If the content of urethane-modified (meth)acrylic resin (A) is below the above lower limit, the ability to achieve both curl resistance, solvent resistance, and blocking resistance of the coating film will be impaired.

[0060] The solid content of hydrocarbon wax (B) is preferably 0.1 to 5.0% by mass, more preferably 0.3 to 4.0% by mass, and particularly preferably 0.5 to 3.0% by mass, relative to the total mass of the oil-based ink composition. The content of hydrocarbon wax (B) on a solids basis is 0.7 to 9.0% by mass, preferably 0.8 to 6.5% by mass, and more preferably 1.0 to 4.0% by mass, relative to the total solids of the oil-based ink composition. If the hydrocarbon wax (B) content is below the lower limit, the abrasion resistance of the coating film will decrease. If the hydrocarbon wax (B) content exceeds the upper limit, the solvent resistance and blocking resistance of the coating film will decrease.

[0061] The total content of urethane-modified (meth)acrylic resin (A) and hydrocarbon wax (B) on a solid content basis (hereinafter also referred to as "A + B amount") is preferably 10 to 32% by mass, more preferably 14 to 30% by mass, and particularly preferably 18 to 28% by mass, based on the total mass of the oil-based ink composition. The amount of A+B is preferably 13.7 to 80.0% by mass, more preferably 17.5 to 75.0% by mass, and particularly preferably 25.0 to 70.0% by mass, relative to the total solid content of the oil-based ink composition. If the A+B ratio is below the lower limit, the abrasion resistance of the coating film, adhesion to the substrate, and storage stability of the oil-based ink composition will be slightly reduced. If the A+B ratio exceeds the upper limit, the fluidity and printability of the oil-based ink composition will be slightly reduced.

[0062] The content of organic solvent (C) is preferably 5 to 90% by mass, more preferably 8 to 80% by mass, and particularly preferably 10 to 70% by mass, based on the total mass of the oil-based ink composition. If the content of organic solvent (C) is below the lower limit, the fluidity and printability of the oil-based ink composition will be slightly reduced. If the content of organic solvent (C) exceeds the upper limit, the printability and storage stability of the oil-based ink composition will be slightly reduced.

[0063] The total amount of urethane-modified (meth)acrylic resin (A) and hydrocarbon wax (B) on a solid content basis, plus the amount of organic solvent (C) (hereinafter also referred to as "A+B+C amount"), is preferably 25 to 100% by mass, more preferably 25 to 98% by mass, even more preferably 30 to 95% by mass, and particularly preferably 35 to 92% by mass, based on the total mass of the oil-based ink composition. If the amount of A+B+C is below the lower limit, the adhesion of the coating film to the substrate and the storage stability of the oil-based ink composition will be slightly reduced. If the amount of A+B+C exceeds the upper limit, the solvent resistance of the coating film will be slightly reduced.

[0064] When the oil-based ink composition contains pigment (D), the content of pigment (D) on a solid content basis is preferably 10 to 60% by mass, more preferably 12 to 58% by mass, and particularly preferably 14 to 56% by mass, based on the total mass of the oil-based ink composition. When the oil-based ink composition contains pigment (D), the content of pigment (D) on a solids basis is preferably 25 to 70% by mass, more preferably 28 to 65% by mass, and particularly preferably 30 to 60% by mass, relative to the total solids of the oil-based ink composition. If the pigment (D) content is below the lower limit, the opacity, color development, and blocking resistance of the coating film will be slightly reduced. If the pigment (D) content exceeds the upper limit, the adhesion of the coating film to the substrate, the storage stability of the oil-based ink composition, and its fluidity will be slightly reduced.

[0065] When the oil-based ink composition contains a curing agent (E), the content of the curing agent (E) on a solid content basis is preferably 0.5 to 20.0% by mass, more preferably 3.0 to 18.0% by mass, and particularly preferably 6.0 to 16.0% by mass, relative to the total mass of the oil-based ink composition. When the oil-based ink composition contains a curing agent (E), the content of the curing agent (E) on a solids basis is preferably 5 to 45% by mass, more preferably 8 to 40% by mass, and particularly preferably 10 to 35% by mass, relative to the total solids of the oil-based ink composition. If the content of hardener (E) is below the lower limit, the solvent resistance and abrasion resistance of the coating film will be slightly reduced. If the content of hardener (E) exceeds the upper limit, the blocking resistance of the coating film will be slightly reduced.

[0066] The content of other optional components on a solid content basis is not particularly limited as long as it does not impair the effects of the present invention, but for example, 0 to 20% by mass is preferred, 0 to 15% by mass is more preferred, and 0 to 10% by mass is particularly preferred, based on the total mass of the oil-based ink composition. If the oil-based ink composition contains other optional components, the content of these other optional components on a solids basis is preferably 0.01% by mass or more, more preferably 0.10% by mass or more, and particularly preferably 0.50% by mass or more, relative to the total mass of the oil-based ink composition. If the content of other optional components exceeds the above upper limit, the effects of the present invention may not be fully obtained.

[0067] <Manufacturing method> The oil-based ink composition of this embodiment can be obtained, for example, by mixing a urethane-modified (meth)acrylic resin (A), a hydrocarbon wax (B), an organic solvent (C), a pigment (D) if necessary, a curing agent (E) if necessary, and other optional components if necessary. The method of mixing each component is not particularly limited, and the components can be mixed by various methods. For example, one method is to dissolve or disperse a urethane-modified (meth)acrylic resin (A), a hydrocarbon wax (B), a pigment (D) if necessary, a curing agent (E) if necessary, and other optional components in an organic solvent (C). In particular, it is preferable to add the curing agent (E) immediately before using the oil-based ink composition.

[0068] The method for dissolving or dispersing each component in the organic solvent (C) is not particularly limited and can be carried out using known dispersers. Examples of dispersers include paint shakers, dissolvers, ball mills, attritors, sand mills, bead mills, dyno mills, roll mills, ultrasonic mills, and high-pressure impact dispersers. In this case, the dispersion treatment may be performed once or multiple times using one type of disperser, or multiple dispersion treatments may be performed using two or more types of dispersers in combination.

[0069] <Effects and Effects> According to the oil-based ink composition of this embodiment described above, by containing the above-mentioned specific urethane-modified (meth)acrylic resin (A), specific hydrocarbon wax (B), and organic solvent (C), and having a solid content of 13.0 to 72.0% by mass of urethane-modified (meth)acrylic resin (A) and a hydrocarbon wax (B) content of 0.7 to 9.0% by mass, it is possible to form a coating film that has excellent curl resistance, which prevents curling of printed materials even when printed on plastic films less than 10 μm thick, and also has excellent solvent resistance, blocking resistance, and abrasion resistance.

[0070] <Application> The oil-based ink composition of this embodiment is suitable as an ink for printing on the surface of any substrate, such as a plastic film (or, if any layer, such as a pattern layer, is formed on the surface of the substrate, on the surface of this layer). In particular, it is suitable as an ink for printing on the surface of the substrate or the surface of the aforementioned layer by gravure printing. That is, the oil-based ink composition of this embodiment is especially suitable for gravure printing. The oil-based ink composition of this embodiment may be used as is as ink, or a diluted solution obtained by diluting it with a medium such as an organic solvent may be used as ink. The oil-based ink composition of this embodiment is printed on any substrate to form an ink layer. Hereinafter, the ink layer formed using the oil-based ink composition will also be referred to as the printed layer.

[0071] [Laminated structure] Figure 1 shows an example of a laminate according to one embodiment of the present invention. Note that the dimensional ratios in Figure 1 differ from those of the actual dimensions for the sake of explanation. The laminate 10 in Figure 1 is a printed material comprising a plastic film 11 which is a base material and an ink layer 12 printed on one surface of the plastic film 11.

[0072] <Plastic film> Examples of resins constituting the plastic film 11 include plastic films (base films) made of polyolefins (e.g., polyethylene (PE), milky polyethylene, polypropylene (PP), etc.), polyesters (e.g., polyethylene terephthalate (PET), etc.), polystyrene (PS), stretched polypropylene (OPP), polyamide (NY), etc.). These plastic films 11 may be used individually or two or more types may be laminated together.

[0073] The plastic film 11 may have a single-layer structure or a laminated structure. That is, the plastic film 11 may be a single-layer film or a laminated film. If the plastic film 11 is a laminated film, it may be a configuration in which two or more films of the same type are laminated together, or a configuration in which two or more films of different types are laminated together.

[0074] The plastic film 11 may or may not be subjected to corona treatment. The thickness of the plastic film 11 (or the thickness after lamination if two or more types are used together) is not particularly limited, but for example, when the laminate 10 is used as an industrial tape, it is preferably 25 μm or less, more preferably 15 μm or less, even more preferably 10 μm or less, and particularly preferably less than 10 μm. It may also be 1 μm or more, 3 μm or more, or 5 μm or more. The above upper and lower limits can be combined as appropriate. Furthermore, the thickness of the plastic film 11 may be 10 μm or more, for example, 10 to 50 μm.

[0075] <Ink layer> In the illustrated example laminate 10, the ink layer 12 is provided on one surface of the plastic film 11. The ink layer 12 is a layer formed using the oil-based ink composition of the present invention described above. The ink layer 12 may have a single-layer structure or a multi-layer structure. The ink layer 12 may be the pattern layer. The thickness of the ink layer 12 is not particularly limited and may be, for example, 0.1 to 1 μm. However, if the ink layer contains particles (for example, hydrocarbon wax (B) particles, pigment (D) particles, etc.) and some of the particles protrude above the surface of the ink layer, the thickness of the ink layer shall be the thickness of the portion where the particles do not protrude.

[0076] <Method for manufacturing laminates> The manufacturing method of the laminate 10 of this embodiment includes the step of forming an ink layer 12 on one surface of the plastic film 11 using the oil-based ink composition of the present invention. In the method for manufacturing the laminate 10 of the present invention, for example, the oil-based ink composition of the present invention is applied to one surface of a plastic film 11 to form a coating film which serves as a laminate precursor, and then the coating film is dried to form an ink layer 12. After drying the coating film to form the ink layer 12, the obtained ink layer 12 may be further aged. In particular, if the oil-based ink composition contains a curing agent (E), it is preferable to age the ink layer 12. Aging promotes the crosslinking reaction by the curing agent (E). The step of aging the ink layer 12 is also called the "aging step". Alternatively, the oil-based ink composition of the present invention may be applied to one surface of a plastic film 11, the resulting coating film may be dried to form an ink layer 12, and then the oil-based ink composition of the present invention may be applied again (overcoated), and the resulting coating film may be dried, repeating this process one or more times to form a laminated ink layer. When applying multiple coats of the oil-based ink composition of the present invention, the composition of each oil-based ink composition may be the same or different.

[0077] The method for forming the ink layer 12 may be a known printing method. For example, the oil-based ink composition of the present invention is applied to one surface of the plastic film 11, and the ink layer 12 is formed by drying the coating film. The coating method may be any known coating method, such as gravure printing, flexographic printing, brush coating, gravure coater, die coater, bar coater, spray coating, flow coating, dip coating, spin coating, and curtain coating. Among these, gravure printing is preferred due to its superior quality and productivity.

[0078] The drying method for the coating film is not particularly limited as long as it removes the organic solvent (C) contained in the oil-based ink composition coated on one surface of the plastic film 11, and known drying methods can be used. For example, it may be air-dried, or it may be a forced drying method such as vacuum drying, pressure drying, heat drying, or air drying. When drying by heating, the drying temperature is preferably 30 to 70°C. The conditions for the aging process are not particularly limited, but for example, the aging temperature is preferably 30 to 70°C and the aging time is preferably 24 to 72 hours.

[0079] <Effects and Effects> The laminate of this embodiment described above has an ink layer formed using the oil-based ink composition of the present invention described above on one surface of a plastic film, and exhibits excellent curl resistance, solvent resistance, blocking resistance, and abrasion resistance.

[0080] <Application> The laminate of this embodiment is suitable as an industrial tape. An example of an industrial tape is one that comprises the laminate of the present invention. Furthermore, the laminate of this embodiment can also be used as packaging material, such as a packaging label.

[0081] <Other Embodiments> The laminate is not limited to the embodiments described above. For example, as shown in Figure 2, the laminate 10 may further include a pattern layer 13 between the plastic film 11 and the ink layer 12. That is, the pattern layer 13 and the ink layer 12 may be formed in this order on one surface of the plastic film 11. Furthermore, as shown in Figure 3, for example, the laminate 10 may further include a pattern layer 13 on the other surface of the plastic film 11. That is, the pattern layer 13, the plastic film 11, and the ink layer 12 may be laminated in this order. If the ink layer 12 is the pattern layer, then the pattern layer 13 is a pattern layer other than the ink layer 12 (hereinafter also referred to as "other pattern layers").

[0082] The pattern layer 13 is a printing layer typically formed using ink. The ink may be a known ink. The ink typically contains pigments. The method for forming the pattern layer 13 may be a known printing method, similar to the method for forming the ink layer 12. Although the pattern layer 13 shown in FIG. 2 is provided over the entire one surface of the plastic film 11, the pattern layer 13 may be provided on a part of one surface of the plastic film 11. That is, a part of one surface of the plastic film 11 may be exposed from the pattern layer 13. Also, although the pattern layer 13 shown in FIG. 3 is provided over the entire other surface of the plastic film 11, the pattern layer 13 may be provided on a part of the other surface of the plastic film 11. That is, a part of the other surface of the plastic film 11 may be exposed from the pattern layer 13.

Example

[0083] Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to the following examples as long as the gist thereof is not exceeded.

[0084] [Raw materials used] <Urethane-modified (meth)acrylic resin (A)> As the urethane-modified (meth)acrylic resin (A) or its comparative product, the following compounds were used. · A-1: Urethane / (meth)acrylic ratio: 0.25, glass transition temperature of (meth)acrylic part: 75°C, glass transition temperature of urethane part: -20°C, overall glass transition temperature: 56°C, hydroxyl value: 103 mgKOH / g, acid value: 1 mgKOH / g, SP value: 11.40 (cal / cm 3 ) 1 / 2 , (meth)acrylic part: methyl methacrylate-based, non-volatile content: 30% by mass. A-2: Urethane / (meth)acrylic ratio: 0.43, Glass transition temperature of (meth)acrylic portion: 82°C, Glass transition temperature of urethane portion: 10°C, Overall glass transition temperature: 60°C, Hydroxyl value: 43 mg KOH / g, Acid value: 6.3 mg KOH / g, SP value: 10.96 (cal / cm²) 3 ) 1 / 2 (Meth)acrylic part: methyl methacrylate type, non-volatile content: 40% by mass. A-3: Urethane / (meth)acrylic ratio: 0.25, Glass transition temperature of (meth)acrylic portion: 75°C, Glass transition temperature of urethane portion: -30°C, Overall glass transition temperature: 54°C, Hydroxyl value: 103 mg KOH / g, Acid value: 0.77 mg KOH / g, SP value: 11.41 (cal / cm²) 3 ) 1 / 2 (Meth)acrylic part: methyl methacrylate type, non-volatile content: 29.5% by mass. · A-4: Urethane / (meth)acrylic ratio: 0.67, Glass transition temperature of (meth)acrylic portion: 60℃, Glass transition temperature of urethane portion: -10℃, Overall glass transition temperature: 32℃, Hydroxyl value: 35 mg KOH / g, Acid value: 6.9 mg KOH / g, SP value: 10.84 (cal / cm²) 3 ) 1 / 2 (Meth)acrylic part: methyl methacrylate type, non-volatile content: 30% by mass. · A-5: Urethane / (meth)acrylic ratio: 1.0, Glass transition temperature of (meth)acrylic part: 60°C, Glass transition temperature of urethane part: 40°C, Overall glass transition temperature: 50°C, Hydroxyl value: 0 mg KOH / g, Acid value: 7.5 mg KOH / g, (meth)acrylic part: Methyl methacrylate type, Non-volatile content: 41.5% by mass. A comparative product of urethane-modified (meth)acrylic resin (A). · A-6: Urethane / (meth)acrylic ratio: 0.43, Glass transition temperature of (meth)acrylic part: 30℃, Glass transition temperature of urethane part: -10℃, Overall glass transition temperature: 18℃, Hydroxyl value: 90 mg KOH / g, Acid value: 5.7 mg KOH / g, SP value: 11.26 (cal / cm²) 3 ) 1 / 2 (Meth)acrylic part: methyl methacrylate type, non-volatile content: 35.5% by mass. Comparative product of urethane-modified (meth)acrylic resin (A). A-7: Urethane / (meth)acrylic ratio: 0.82, (meth)acrylic part glass transition temperature: 105℃, hydroxyl value: 11mgKOH / g, acid value: 0.57mgKOH / g, (meth)acrylic part: methyl methacrylate type, non-volatile content: 35% by mass. A comparative product of urethane-modified (meth)acrylic resin (A).

[0085] <Other binder resins> The following compounds were used as other binder resins. • Acrylic polyol resin: Manufactured by Taisei Fine Chemical Co., Ltd., product name "Acrit 6AN-830D", hydroxyl value: 27.4 mg KOH / g, acid value: 1.0 mg KOH / g, glass transition temperature: 86.1℃, non-volatile content: 40% by mass. • Polyurethane resin: Manufactured by Sanyo Chemical Industries, Ltd., product name "Sunprene IB-1700D", hydroxyl value: 3.3 mg KOH / g, glass transition temperature: -45℃, non-volatile content: 30% by mass.

[0086] <Hydrogen wax (B)> The following compounds were used as hydrocarbon wax (B). B-1: Polyolefin wax (manufactured by Mitsui Chemicals, Inc., product name "High Wax 420P", penetration: 3, non-volatile content: 100% by mass). B-2: Polyolefin wax (manufactured by Mitsui Chemicals, Inc., product name "High Wax 320P", penetration: 7, non-volatile content: 100% by mass). B-3: Polyolefin wax (manufactured by Mitsui Chemicals, Inc., product name "High Wax 220P", penetration: 13, non-volatile content: 100% by mass). B-4: Polyolefin wax (manufactured by Mitsui Chemicals, Inc., product name "High Wax 110P", penetration: 25, non-volatile content: 100% by mass).

[0087] <Organic solvent (C)> The following compounds were used as the organic solvent (C). • C-1: A mixed solvent of methyl ethyl ketone and n-propyl acetate (methyl ethyl ketone: n-propyl acetate = 3:1 (mass ratio)).

[0088] <Pigment (D)> The following compounds were used as pigments (D). D-1: Carbon black (manufactured by Mitsubishi Chemical Corporation, product name "Mitsubishi Carbon Black MA100", non-volatile content: 100% by mass). D-2: Titanium dioxide (manufactured by Teika Co., Ltd., product name "Titanix JR-806", non-volatile content: 100% by mass). D-3: Phthalocyanine blue (manufactured by Dainichi Seika Kogyo Co., Ltd., product name "Cyanine Blue ZCA-350-EP", non-volatile content: 100% by mass).

[0089] <Hardening agent (E)> The following compound was used as the curing agent (E). • E-1: Isocyanate-based curing agent (manufactured by Mitsui Chemicals, Inc., product name "Takenate D-160N", non-volatile content: 75% by mass, TMP adduct of hexamethylene diisocyanate). • E-2: Isocyanate-based curing agent (manufactured by Mitsui Chemicals, Inc., product name "Takenate D-140N", non-volatile content: 75% by mass, TMP adduct of isophorone diisocyanate). • E-3: Isocyanate-based curing agent (manufactured by Mitsui Chemicals, Inc., product name "Takenate D-110N", non-volatile content: 75% by mass, TMP adduct of xylylene diisocyanate). • E-4: Isocyanate-based curing agent (manufactured by Mitsui Chemicals, Inc., product name "Takenate D-103", non-volatile content: 75% by mass, TMP adduct of tolylene diisocyanate).

[0090] <Other optional components> The following compounds were used as optional components other than the binder resin. • Dispersant: Manufactured by Lubrizol Japan Co., Ltd., product name "Solspers 20000", non-volatile content: 100% by mass.

[0091] [Evaluation Method] <Evaluation of curl resistance> The laminate (after aging) was cut into pieces measuring 2.5 cm in width and 15 cm in length to prepare test specimens. The obtained test specimens were left standing for 1 hour in an environment of 25°C and 60% relative humidity. Then, the test specimens were placed on a flat surface with the curled side facing upwards, and the distance from the surface to the end of the curled test specimen (curl height) was measured. Curl tests were performed on three test specimens, the curl height was measured, and the average value was taken as the curl height. The curl resistance of the ink layer was evaluated according to the evaluation criteria shown below. A score of 3 to 5 is considered acceptable. 5: The curl height is 0 mm. 4: Curl height is greater than 0mm but less than or equal to 1mm. 3: The curl height is greater than 1 mm and less than or equal to 3 mm. 2: The curl height is greater than 3mm but less than or equal to 5mm. 1: The curl height exceeds 5mm.

[0092] <Evaluation of solvent resistance (isopropanol)> The laminate (after aging) was left to stand for 1 hour in an environment of 25°C and 60% relative humidity. After standing, the surface of the ink layer of the laminate was subjected to a friction test using a JSPS-type friction fastness tester (manufactured by Tester Sangyo Co., Ltd., product name "AB-301"), with a black cloth (No. 3) soaked in isopropanol (IPA) applied under a load of 500 gf and rubbed back and forth 30 times. After that, the appearance of the ink layer was visually inspected, and the solvent resistance (isopropanol) of the ink layer was evaluated according to the evaluation criteria shown below. A score of 3 to 5 is considered acceptable. 5: The area of ​​the ink layer that has migrated to the black cloth (gold cloth No. 3) is 0% of the total area of ​​the ink layer. 4. The percentage of the ink layer area transferred to the black cloth (gold cloth No. 3) is greater than 0% and less than or equal to 5% of the total ink layer area. 3: The proportion of the ink layer area transferred to the black cloth (gold cloth No. 3) is more than 5% and 10% or less of the total ink layer area. 2: The proportion of the ink layer area transferred to the black cloth (gold cloth No. 3) is between 10% and 30% of the total ink layer area. 1: The area of ​​the ink layer that has been transferred to the black cloth (gold cloth No. 3) exceeds 30% of the total area of ​​the ink layer.

[0093] <Evaluation of solvent resistance (ethyl acetate)> The laminate (after aging) was left to stand for 1 hour in an environment of 25°C and 60% relative humidity. After standing, the surface of the ink layer of the laminate was subjected to a friction test using a JSPS-type friction fastness tester (manufactured by Tester Sangyo Co., Ltd., product name "AB-301"), by rubbing it back and forth 30 times with a black cloth (No. 3) soaked in ethyl acetate (EtAc) under a load of 500 gf. After that, the appearance of the ink layer was visually inspected, and the solvent resistance (ethyl acetate) of the ink layer was evaluated according to the evaluation criteria shown below. A score of 3 to 5 is considered acceptable. 5: The area of ​​the ink layer that has migrated to the black cloth (gold cloth No. 3) is 0% of the total area of ​​the ink layer. 4. The percentage of the ink layer area transferred to the black cloth (gold cloth No. 3) is greater than 0% and less than or equal to 5% of the total ink layer area. 3: The proportion of the ink layer area transferred to the black cloth (gold cloth No. 3) is more than 5% and 10% or less of the total ink layer area. 2: The proportion of the ink layer area transferred to the black cloth (gold cloth No. 3) is between 10% and 30% of the total ink layer area. 1: The area of ​​the ink layer that has been transferred to the black cloth (gold cloth No. 3) exceeds 30% of the total area of ​​the ink layer.

[0094] <Evaluation of blocking resistance> Two laminate precursors were prepared. Two laminate precursors are stacked so that the coated film side (printed side) of one laminate precursor is in contact with the plastic film (PET film) side (unprinted side) of the other laminate precursor, and the load is 2 kg / cm². 2 The samples were subjected to a load and stored in a 40°C constant temperature chamber for 24 hours. Afterward, the two laminate precursors were separated, and the blocking resistance of the coating films was evaluated according to the evaluation criteria shown below. A score of 3 to 5 is considered acceptable. Note that "ink removal" below refers to the situation where, during separation, the coating film of one laminate precursor remains attached to the opposing surface (in this evaluation, the non-printed surface of the other laminate precursor) while the coating film of the other laminate precursor peels off the plastic film. 5: No ink is absorbed onto the non-printed surface. 4. Ink removal to the non-printed surface is greater than 0% and less than or equal to 10% of the total surface area of ​​the coating film. 3. Ink removal to the non-printed surface is between 10% and 30% of the total surface area of ​​the coating film. 2: Ink removal to the non-printed surface is between 30% and 50% of the total surface area of ​​the coating film. 1: Ink removal to the non-printed surface exceeds 50% of the total surface area of ​​the coating film.

[0095] <Evaluation of printability> An oil-based ink composition was diluted with an organic solvent (C-1) to a viscosity of 17 seconds at 25°C, as measured using a Zahn cup #3, to prepare a printing ink. The resulting ink was supplied to the ink pan of a 5-color gravure printing press (manufactured by Fuji Machinery Industry Co., Ltd.) equipped with a commercially available steel doctor blade and a plate with only non-image areas, and the plate was run idle for 30 minutes at a rate of 150 m / min. Afterward, streaky stains (doctor blade streaks) that appeared on the plate surface were visually inspected, and the printability of the oil-based ink composition was evaluated according to the evaluation criteria shown below. A score of 3 to 5 was considered acceptable. 5: No or very faint doctor's muscle was observed, or 1-2 very faint doctor's muscles were found. 4: Three to five thin muscle fibers were identified. 3: Six or more thin doctor's muscles, or one or two thick doctor's muscles were identified. 2: Three to five thick muscle fibers were observed. 1: More than six thick, defined muscle fibers were observed.

[0096] <Evaluation of abrasion resistance> The laminate (after aging) was left to stand for 1 hour in an environment of 25°C and 60% relative humidity. After standing, the surface of the ink layer of the laminate was subjected to a friction test using a JSPS-type friction fastness tester (manufactured by Tester Sangyo Co., Ltd., product name "AB-301"), with a black cloth (metal cloth No. 3) applied under a load of 500 gf and rubbed back and forth 200 times. After that, the appearance of the ink layer was visually inspected, and the friction resistance of the ink layer was evaluated according to the evaluation criteria shown below. A score of 3 to 5 is considered acceptable. 5: The area of ​​the ink layer that has migrated to the black cloth (gold cloth No. 3) is 0% of the total area of ​​the ink layer. 4. The percentage of the ink layer area transferred to the black cloth (gold cloth No. 3) is greater than 0% and less than or equal to 5% of the total ink layer area. 3: The proportion of the ink layer area transferred to the black cloth (gold cloth No. 3) is more than 5% and 10% or less of the total ink layer area. 2: The proportion of the ink layer area transferred to the black cloth (gold cloth No. 3) is between 10% and 30% of the total ink layer area. 1: The area of ​​the ink layer that has been transferred to the black cloth (gold cloth No. 3) exceeds 30% of the total area of ​​the ink layer.

[0097] [Examples 1-17, Comparative Examples 1-11] <Preparation of oil-based ink composition> According to the compositions shown in Tables 1-5, a urethane-modified (meth)acrylic resin (A), another binder resin, a hydrocarbon wax (B), an organic solvent (C), a pigment (D), and other optional components were mixed to obtain a mixture. If the mixture contained pigment (D), the resulting mixture was kneaded in a paint shaker; if the mixture did not contain pigment (D), the resulting mixture was stirred in a dissolver, and then, if a curing agent (E) was to be added, the curing agent (E) was added and the mixture was further kneaded in a paint shaker to obtain an oil-based ink composition. The hardening agent (E) was added immediately before preparing the printing ink in the following step, <Laminate Preparation>.

[0098] <Fabrication of laminates> The prepared oil-based ink composition was diluted with an organic solvent (C-1) to a viscosity of 18 seconds at 25°C, as measured using a Zahn cup #3, to prepare a printing ink. Using a gravure printing press (manufactured by Matsuo Sangyo Co., Ltd., product name "K Printing Proofer") equipped with a 150-line / inch (40 μm) gravure engraving plate, the prepared printing ink was applied to one side of a PET film (manufactured by Toray Industries, Inc., product name "Lumirror #6C-F53", thickness: 6 μm) as the plastic film, and a laminate precursor with a coated film formed on the plastic film was obtained. Next, the laminate precursor was hot-air dried at 60°C for 1 minute, and then aged at 40°C for 48 hours to obtain a laminate (printed material) with a 3 μm thick ink layer formed on the plastic film. The printability was evaluated using an oil-based ink composition, the blocking resistance was evaluated using a laminate precursor, and the curl resistance, solvent resistance, and abrasion resistance were evaluated using the laminate (after aging). These results are shown in Tables 1 to 5.

[0099] [Table 1]

[0100] [Table 2]

[0101] [Table 3]

[0102] [Table 4]

[0103] [Table 5]

[0104] The amounts of each component other than organic solvent (C) in Tables 1-5 are calculated on a solids basis. A blank space in Tables 1-5 indicates that the ingredient is not included (0% by mass). In Tables 1-5, "residue" refers to the amount of organic solvent (C) added, adjusted so that the total amount (mass%) of all components in the oil-based ink composition equals 100% by mass. In Tables 1-5, "Content of (A)" refers to the content of urethane-modified (meth)acrylic resin (A) on a solids basis relative to the total solids of the oil-based ink composition, rounded to two decimal places. In Tables 1-5, "Content of (B)" refers to the content of hydrocarbon wax (B) on a solid basis relative to the total solid content of the oil-based ink composition, rounded to two decimal places.

[0105] As is clear from the results in Tables 1-3, the oil-based ink compositions obtained in each example exhibited excellent printability. Furthermore, the coatings formed from these oil-based ink compositions exhibited excellent curl resistance, solvent resistance, blocking resistance, and abrasion resistance.

[0106] On the other hand, as is clear from the results in Tables 4 and 5, the coating film formed from the oil-based ink composition obtained in Comparative Example 1, which used a urethane-modified (meth)acrylic resin with a urethane / (meth)acrylic ratio of 1.0, was inferior in solvent resistance and blocking resistance. In Comparative Example 2, which used a urethane-modified (meth)acrylic resin with a glass transition temperature of 30°C in the (meth)acrylic portion, the coating film formed from the oil-based ink composition exhibited poor solvent resistance and blocking resistance. The coating film formed from the oil-based ink composition obtained in Comparative Example 3, which used a urethane-modified (meth)acrylic resin with a glass transition temperature of 105°C in the (meth)acrylic portion, exhibited poor curl resistance. In Comparative Example 4, where an acrylic polyol resin was used instead of a urethane-modified (meth)acrylic resin (A), the coating film formed from the oil-based ink composition exhibited poor curl resistance. In Comparative Example 5, where a polyurethane resin was used instead of a urethane-modified (meth)acrylic resin (A), the coating film formed from the oil-based ink composition exhibited poor solvent resistance and blocking resistance. The coating film formed from the oil-based ink composition obtained in Comparative Example 6, which contained 12.5% ​​by mass of urethane-modified (meth)acrylic resin (A), exhibited poor curl resistance and solvent resistance. The coating film formed from the oil-based ink composition obtained in Comparative Example 7, which contained 72.7% by mass of urethane-modified (meth)acrylic resin (A), exhibited poor blocking resistance. The coating film formed from the oil-based ink composition obtained in Comparative Example 8, which contained 0.6% by mass of hydrocarbon wax (B), had poor abrasion resistance. The coating film formed from the oil-based ink composition obtained in Comparative Example 9, which contained 9.6% by mass of hydrocarbon wax (B), exhibited poor solvent resistance. The coating film formed from the oil-based ink composition obtained in Comparative Example 10, which used a hydrocarbon wax with a penetration degree of 25, exhibited poor solvent resistance. The coating film formed from the oil-based ink composition obtained in Comparative Example 11, which did not contain hydrocarbon wax (B), exhibited poor abrasion resistance. [Industrial applicability]

[0107] The oil-based ink composition of the present invention has excellent curl resistance, which prevents curling of printed materials even when printed on plastic films less than 10 μm thick, and can form a coating film with excellent solvent resistance, blocking resistance, and abrasion resistance, making it useful as an ink for industrial tapes. [Explanation of Symbols]

[0108] 10 Laminate 11 Plastic film 12 Ink Layers 13 Image Layers

Claims

1. An oil-based ink composition containing a urethane-modified (meth)acrylic resin (A), a hydrocarbon wax (B), and an organic solvent (C), The urethane-modified (meth)acrylic resin (A) is a graft polymer having a (meth)acrylic portion as its main skeleton and a urethane portion as its side chains. In the urethane-modified (meth)acrylic resin (A), the mass ratio represented by the urethane portion / (meth)acrylic portion is 0.1 to 0.

9. The glass transition temperature of the (meth)acrylic portion constituting the urethane-modified (meth)acrylic resin (A) is 40 to 100°C. The content of the urethane-modified (meth)acrylic resin (A) on a solids basis is 13.0 to 72.0% by mass relative to the total solids of the oil-based ink composition. The penetration degree of the hydrocarbon wax (B) is 20 or less. An oil-based ink composition in which the content of the hydrocarbon wax (B) on a solid content basis is 0.7 to 9.0% by mass relative to the total solid content of the oil-based ink composition.

2. The oil-based ink composition according to claim 1, wherein the mass ratio of the urethane portion to the (meth)acrylic portion in the urethane-modified (meth)acrylic resin (A) is 0.1 to 0.

5.

3. The oil-based ink composition according to claim 1, wherein the hydroxyl value of the urethane-modified (meth)acrylic resin (A) is 40 to 120 mgKOH / g or less.

4. The oil-based ink composition according to claim 1, further comprising pigment (D).

5. It further contains a hardening agent (E), The oil-based ink composition according to claim 1, wherein the curing agent (E) comprises one or more selected from hexamethylene diisocyanate, isophorone diisocyanate, m-xylylene diisocyanate, and adducts thereof.

6. An oil-based ink composition for gravure printing, according to any one of claims 1 to 5.

7. A laminate comprising a plastic film and an ink layer formed on one surface of the plastic film using the oil-based ink composition described in claim 6.

8. The laminate according to claim 7, further comprising a pattern layer between the plastic film and the ink layer, or on the other surface of the plastic film.

9. An industrial tape comprising the laminate described in claim 8.

Images