Aqueous ink composition, aqueous ink, laminate, label, and packaging body

Abstract

To provide an aqueous ink composition capable of forming a coating film having excellent coating film properties such as substrate adhesion, abrasion resistance, wet abrasion resistance, heat resistance, and scratch resistance.SOLUTION: An aqueous ink composition comprises an acrylic emulsion resin (A) having an acid value of less than 40 mgKOH / g, an acrylic emulsion resin (B) having an acid value of 40 mgKOH / g or more and 250 mgKOH / g or less, and at least one of titanium oxide and precipitated barium sulfate.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an aqueous ink composition, an aqueous ink, a laminate, a label, and a packaging material. [Background technology]

[0002] Packaging materials such as plastic substrates used for packaging food, daily necessities, etc. are imparted with design and functionality by, for example, gravure printing or flexographic printing using an ink composition. The coating film, which is the printed layer, is required to have physical properties (coating film properties) such as substrate adhesion, abrasion resistance, heat resistance, and scratch resistance.

[0003] Resins contained in ink compositions have been investigated to improve coating film properties. Resins contained in ink compositions also affect the viscosity stability and pigment dispersibility of the ink composition. Titanium oxide and precipitated barium sulfate, which are used as white pigments, are particularly heavy and tend to sink, making them difficult to disperse in ink compositions. Water-soluble acrylic resins with high acid values ​​have been used to improve the dispersibility of titanium oxide and precipitated barium sulfate.

[0004]

[0003] As an aqueous acrylic resin other than the water-soluble acrylic resin, an acrylic emulsion resin is known. It is known that the acrylic emulsion resin can contribute to improving the above-mentioned coating film properties and the physical properties of the ink composition. Core-shell type acrylic emulsion resins having a core portion and a shell portion are well known as acrylic emulsion resins, and many acrylic emulsion resins composed of a core portion that is poorly soluble in water and a shell portion that has excellent compatibility with water are commercially available.

[0005] Patent Document 1 discloses an aqueous liquid ink that uses a specific mass ratio of an acrylic emulsion resin with an acid value of 42 mgKOH / g and a water-soluble acrylic resin with an acid value of 220 mgKOH / g in combination. Patent Document 2 discloses an aqueous ink composition for paper containers that is a mixture of an acrylic emulsion resin and an acrylic resin. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2019-094423 [Patent Document 2] Japanese Patent Application Laid-Open No. 2016-155965 Summary of the Invention [Problem to be solved by the invention]

[0007] When the inventors of the present application produced a coating film using the ink composition described in Patent Document 1, they found that the coating film's physical properties, such as abrasion resistance, heat resistance, and scratch resistance, were insufficient. Furthermore, the coating film's physical properties also require substrate adhesion and water abrasion resistance. An object of the present invention is to provide an aqueous ink composition that can produce a coating film that has excellent coating film physical properties such as substrate adhesion, abrasion resistance, water abrasion resistance, heat resistance, and scratch resistance. Another object of the present invention is to provide an aqueous ink composition that has excellent viscosity stability and excellent dispersibility of pigments such as titanium oxide and precipitated barium sulfate. Additionally, another object of the present invention is to provide an aqueous ink containing the aqueous ink composition, a laminate having a printed layer formed using the aqueous ink, and a label and packaging that include the laminate. [Means for solving the problem]

[0008] The present invention has the following aspects. [1] An aqueous ink composition comprising an acrylic emulsion resin (A), an acrylic emulsion resin (B), and either or both of titanium oxide and precipitated barium sulfate, wherein the acid value of the acrylic emulsion resin (A) is less than 40 mgKOH / g, the acid value of the acrylic emulsion resin (B) is 40 mgKOH / g or more and 250 mgKOH / g or less, the total content of the solid contents of the acrylic emulsion resin (A) and the acrylic emulsion resin (B) is 15 to 40 mass% relative to the total mass of the solid contents of the aqueous ink composition, and the mass ratio of the solid contents of the acrylic emulsion resin (A) to the solid contents of the acrylic emulsion resin (B) is acrylic emulsion resin (A):acrylic emulsion resin (B) = 1:1.0 to 1:40. [2] The water-based ink composition according to [1], wherein the glass transition temperature of the acrylic emulsion resin (A) is −20 to 60°C, and the glass transition temperature of the acrylic emulsion resin (B) is −20 to 60°C. [3] The aqueous ink composition according to [1] or [2], which is used together with a curing agent. [4] The water-based ink composition according to any one of [1] to [3], further comprising resin beads. [5] The water-based ink composition according to [4], wherein the resin beads have an average particle size of 0.5 to 8 μm. [6] The water-based ink composition according to any one of [1] to [5], further comprising a silicone-based resin. [7] The water-based ink composition according to [6], wherein the silicone-based resin is at least one selected from the group consisting of amine-modified silicone, silicone-modified acrylic, and polyether-modified silicone. [8] An aqueous ink comprising the aqueous ink composition according to any one of [1] to [7]. [9] The water-based ink according to [8], which is for use on plastic substrates or paper substrates.

[10] A laminate comprising a substrate and a printed layer formed on at least one surface of the substrate using the aqueous ink described in [8] or [9], wherein the substrate is for a plastic substrate or a paper substrate.

[11] A label comprising the laminate according to

[10] .

[12] A package comprising the laminate described in

[10] . [Effects of the Invention]

[0009] According to the present invention, there is provided an aqueous ink composition that can produce a coating film that has excellent coating film physical properties such as substrate adhesion, abrasion resistance, water abrasion resistance, heat resistance, and scratch resistance. The present invention also provides an aqueous ink composition that has excellent viscosity stability and excellent dispersibility of pigments such as titanium oxide and precipitated barium sulfate. Furthermore, there are also provided an aqueous ink containing the aqueous ink composition, a laminate having a printed layer formed using the aqueous ink, and a label and packaging that include the laminate. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a cross-sectional view schematically illustrating an example of a laminate of the present invention. [Figure 2] 1 is a cross-sectional view schematically illustrating an example of a laminate of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0011] The present invention will be described in detail below. The following embodiments are merely examples for explaining the present invention, and are not intended to limit the present invention to these embodiments. The present invention can be implemented in various forms without departing from the spirit of the present invention. In the present invention, the term "aqueous" in the aqueous ink composition (aqueous ink) means that the ink contains water as a medium. Acrylic emulsion resin is a type of water-dispersible acrylic resin. "Solid content" refers to the components contained in the aqueous ink composition (aqueous ink), excluding volatile media such as water and organic solvents, and is the component that will ultimately form the printed layer. Specifically, it is measured in accordance with JIS K 5601-1-2:2008. In this specification, "(meth)acrylate" is a general term for "acrylate" and "methacrylate." "(meth)acrylic acid" is a general term for "acrylic acid" and "methacrylic acid." "(meth)acryloyloxy group" is a general term for "acryloyloxy group" and "methacryloyloxy group." The weight average molecular weight of the acrylic emulsion resin is a weight average molecular weight converted into a standard polystyrene molecular weight and is measured by gel permeation chromatography (GPC). The glass transition temperature of an acrylic emulsion resin is measured in accordance with JIS K 7121:2012 as follows: Using a differential scanning calorimeter, 10 mg of acrylic emulsion resin is heated from -100°C to 160°C at a rate of 20°C / min to obtain a curve (DSC curve), and the glass transition temperature is determined from the intersection of the baseline and the tangent to the endothermic curve. The acid value of an acrylic emulsion resin is the amount of potassium hydroxide required to neutralize acid groups such as carboxyl groups per gram of sample solid content, expressed in milligrams, and is measured in accordance with JIS K 5601-2-1:1999.

[0012] <Water-based ink composition> An aqueous ink composition according to one embodiment of the present invention contains the following acrylic emulsion resin (A), acrylic emulsion resin (B), and either or both of titanium oxide and precipitated barium sulfate. The aqueous ink composition may further contain components (optional components) other than the acrylic emulsion resin (A), the acrylic emulsion resin (B), titanium oxide, and precipitated barium sulfate, as necessary, within a range that does not impair the effects of the present invention. For example, the aqueous ink composition typically further contains an aqueous medium.

[0013] <Acrylic emulsion resin> Acrylic emulsion resin is a type of water-dispersible acrylic resin, such as an emulsion resin with a core-shell structure. The core of the acrylic emulsion resin is made of a hydrophobic acrylic resin with a relatively high molecular weight, and the shell is made of a hydrophilic acrylic resin with a relatively low molecular weight. The core and shell may be bonded together by a crosslinking agent.

[0014] The acrylic emulsion resin is a resin containing (meth)acrylate units. Examples of acrylic emulsion resins include homopolymers of (meth)acrylate, copolymers of two or more kinds of (meth)acrylate, and copolymers of (meth)acrylate and a monomer other than (meth)acrylate. The proportion of (meth)acrylate units to the total mass of all monomer units constituting the acrylic emulsion resin is preferably 10 to 100 mass%, more preferably 20 to 100 mass%. When the acrylic emulsion resin has an acid value, the proportion of (meth)acrylate units to the total mass of all monomer units constituting the acrylic emulsion resin is less than 100 mass%.

[0015] Examples of (meth)acrylates include alkyl (meth)acrylates such as methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, isobutyl (meth)acrylate, n-hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and lauryl (meth)acrylate; cycloalkyl (meth)acrylates such as cyclohexyl (meth)acrylate; aryl (meth)acrylates such as phenyl (meth)acrylate; aralkyl (meth)acrylates such as benzyl (meth)acrylate; and hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate. These (meth)acrylates may be used alone or in combination of two or more.

[0016] Examples of monomers other than (meth)acrylates include conjugated diene compounds such as 1,3-butadiene, isoprene, and chloroprene; aromatic vinyl compounds such as styrene, α-methylstyrene, halogenated styrene, and divinylbenzene; vinyl cyanide compounds such as acrylonitrile and methacrylonitrile; acrylamides such as N,N-dimethyl(meth)acrylamide and N,N-diethyl(meth)acrylamide; unsaturated carboxylic acids such as (meth)acrylic acid, itaconic acid, maleic acid, and fumaric acid; and unsaturated carboxylic acid esters such as diethyl maleate, dibutyl maleate, dibutyl fumarate, diethyl itaconate, and dibutyl itaconate. These monomers may be used alone or in combination of two or more.

[0017] <Acrylic emulsion resin (A)> The acrylic emulsion resin (A) is an acrylic emulsion resin with a low acid value of less than 40 mgKOH / g. The acid value of the acrylic emulsion resin (A) is preferably 36 mgKOH / g or less, and more preferably 32 mgKOH / g or less from the viewpoints of heat resistance, abrasion resistance, and water abrasion resistance. In one embodiment, the acrylic emulsion resin (A) may have no acid value (the acid value may be 0 mgKOH / g). The acid value of the acrylic emulsion resin (A) is preferably 5 mgKOH / g or more, more preferably 10 mgKOH / g or more, and even more preferably 20 mgKOH / g or more from the viewpoints of compatibility with the acrylic emulsion resin (B), abrasion resistance, and water abrasion resistance. When the acid value is less than the upper limit, pigment dispersibility, substrate adhesion, water abrasion resistance, scratch resistance, and heat resistance tend to be improved. When the acid value is equal to or greater than the lower limit, compatibility with the acrylic emulsion resin (B) tends to be improved. When the acid value of the acrylic emulsion resin (A) is 40 mgKOH / g or more, scratch resistance, adhesion, and water abrasion resistance tend to be poor.

[0018] The glass transition temperature (hereinafter also referred to as "Tg") of the acrylic emulsion resin (A) is preferably from -20 to 60°C, more preferably from -10 to 50°C, and even more preferably from 10 to 45°C from the viewpoint of abrasion resistance and water abrasion resistance. When Tg is equal to or greater than the lower limit, the abrasion resistance and water abrasion resistance are likely to be improved.When Tg is equal to or less than the upper limit, the abrasion resistance and water abrasion resistance are likely to be improved.

[0019] The weight average molecular weight (hereinafter also referred to as "Mw") of the acrylic emulsion resin (A) is preferably 20,000 to 1,000,000, more preferably 50,000 to 1,000,000, and from the viewpoint of substrate adhesion, still more preferably 100,000 to 1,000,000. When Mw is equal to or greater than the lower limit, heat resistance is likely to be improved, and when Mw is equal to or less than the upper limit, pigment dispersibility is likely to be improved.

[0020] <Acrylic emulsion resin (B)> The acrylic emulsion resin (B) is an acrylic emulsion resin with a high acid value of 40 to 250 mgKOH / g. The acid value of the acrylic emulsion resin (B) is preferably 40 to 180 mgKOH / g, more preferably 45 to 150 mgKOH / g, and even more preferably 51 to 85 mgKOH / g from the viewpoint of improving abrasion resistance, water abrasion resistance, and heat resistance. When the acid value is equal to or greater than the lower limit, the abrasion resistance, water abrasion resistance, heat resistance, scratch resistance, and substrate adhesion are likely to be improved.When the acid value is equal to or less than the upper limit, the substrate adhesion and water abrasion resistance are likely to be improved. If the acid value of the acrylic emulsion resin (B) is less than 40 mgKOH / g, the adhesion to the substrate will be poor, and if it exceeds 250 mgKOH / g, the water abrasion resistance will be poor.

[0021] The Tg of the acrylic emulsion resin (B) is preferably from -20 to 60°C, and more preferably from -20 to 45°C from the viewpoint of adhesion to the substrate. When Tg is equal to or greater than the lower limit, scratch resistance is likely to be improved, and when Tg is equal to or less than the upper limit, adhesion to substrates is likely to be improved.

[0022] The Mw of the acrylic emulsion resin (B) is preferably from 50,000 to 300,000, more preferably from 50,000 to 500,000, and from the viewpoint of abrasion resistance, even more preferably from 50,000 to 800,000.

[0023] The acrylic emulsion resin is obtained by polymerizing a monomer component containing a (meth)acrylate and, if necessary, a monomer other than the (meth)acrylate. When producing an acrylic emulsion resin having an acid value, it is preferable to use an unsaturated carboxylic acid as the monomer other than the (meth)acrylate. The polymerization method is not particularly limited, and examples thereof include a method of polymerizing a monomer component by solution polymerization, bulk polymerization, emulsion polymerization, etc. in the presence of a known radical polymerization initiator. Among these, emulsion polymerization is preferred. Emulsion polymerization is a method of polymerizing a monomer component in an aqueous medium in the presence of an emulsifier. The acrylic emulsion resin may be produced by separately producing a core portion and a shell portion and then combining them. Alternatively, it may be produced by multi-stage emulsion polymerization. The acrylic emulsion resin may be a self-crosslinking type.

[0024] As the acrylic emulsion resin, a commercially available product may be used. Commercially available acrylic emulsion resins (A) include, for example, products named "Hiros-X-KE-1148" and "Hiros-XJ-140A" manufactured by Seiko PMC Corporation, and products named "Neocryl XK-110," "Neocryl A-662," and "Neocryl XK-12" manufactured by Covestro Coating Resins, Inc. These acrylic emulsion resins (A) may be used alone or in combination of two or more. Commercially available acrylic emulsion resins (B) include, for example, those manufactured by Seiko PMC under the product names "Hiros-X-ME-2039," "Hiros-X-PE-2109," and "Hiros-X-PE-1126," those manufactured by BASF Japan under the product names "Joncryl PDX-7734," "Joncryl PDX-7158," and "Joncryl PDX-7630A," and those manufactured by Covestro Coating Resins under the product names "Neocryl XK-110," "Neocryl A-662," and "Neocryl XK-12." These acrylic emulsion resins (B) may be used alone or in combination of two or more.

[0025] <Titanium oxide> Although the titanium oxide is not particularly limited, titanium oxide having a rutile crystal structure is preferred. The titanium oxide is preferably surface-treated with at least one of silica and alumina. That is, it is preferred that the surface has a treatment layer formed by surface treatment with at least one of silica and alumina. The presence of the treatment layer improves printability. Titanium oxide may be treated with other metals or oxides, such as elemental metals such as Si, Al, Zn, and Zr; and oxides of Al, Zn, and the like. The term "treated" titanium oxide refers to a state in which the surfaces of titanium oxide particles are coated.

[0026] The oil absorption of titanium oxide is preferably 10 to 40 mL / 100 g, and more preferably 15 to 30 mL / 100 g. The oil absorption of titanium oxide is determined in accordance with JIS K 5101-13-1:2004.

[0027] The average particle size of titanium oxide is preferably 0.15 to 0.35 μm, more preferably 0.20 to 0.30 μm. The average particle size of titanium oxide is determined by directly measuring the size of primary particles from images observed under a transmission electron microscope (TEM). Specifically, the particle size of 100 randomly selected primary particles is measured and then averaged to determine the average particle size of titanium oxide.

[0028] Commercially available titanium oxide products may be used, such as those manufactured by Ishihara Sangyo Kaisha under the trade names "CR-50", "CR-50-2", "CR-57", "CR-Super70", "CR-80", "CR-90", "CR-90-2", "CR-93", "CR-95", "CR-953", "CR-97", "UT771", "CR-60", "CR-60-2", "CR-63", "CR-67", "CR-58", "CR-58-2", "CR-85", "R-820", "R-830", "R-930", "R-980", "R-550", "R-630", "R-680", "R-780", "R-780-2", and "R-850". , "A-100", "A-220", and "W-10"; trade names manufactured by Teika Corporation: "JR-301", "JR-403", "JR-405", "JR-600A", "JR-605", "JR-600E", "JR-603", "JR-805", "JR-806", "JR-701", "JRNC", "JR-800", "JA-1", "JA-C", "JA-3", "JA-4", and "JA-5"; and trade names manufactured by Sakai Chemical Industry Co., Ltd.: "A-190", "R-25", "R-21", "R-32", "R-33", "R-7E", "R-62N", "R-78", "R-42", and "R-45M". These titanium oxides may be used alone or in combination of two or more.

[0029] <Precipitated barium sulfate> As the precipitated barium sulfate, any precipitated barium sulfate known in the art can be used. The average particle size of the precipitated barium sulfate is preferably 0.01 to 1 μm. The average particle size of the precipitated barium sulfate is the cumulative 50% particle size on a volume basis measured by a laser diffraction / light scattering method.

[0030] <Optional ingredients> Examples of optional components include an aqueous medium, resin beads, silicone resins, and additives.

[0031] (aqueous medium) Examples of aqueous media include water and mixed solvents of water and organic solvents. The organic solvent in the mixed solvent is not particularly limited as long as it is soluble in water, and examples thereof include alcohol-based solvents such as methanol, ethanol, n-propanol, isopropanol, n-butanol, and isobutanol; ketone-based solvents such as acetone; glycol ether-based solvents such as propylene glycol monomethyl ether; etc. These organic solvents may be used alone or in combination of two or more.

[0032] The content of water relative to the total mass of the aqueous medium is preferably from 60 to 100% by mass, more preferably from 70 to 100% by mass, and even more preferably from 80 to 100% by mass.

[0033] (resin beads) The resin beads are used to improve the abrasion resistance, water abrasion resistance, and scratch resistance of the resulting coating film. Examples of the resin type of the resin beads include acrylic resin, styrene resin, silicone resin, and urethane resin, with acrylic resin being preferred. The average particle size of the resin beads is preferably 0.5 to 8 μm, more preferably 0.5 to 5 μm, and even more preferably 0.5 to 2 μm from the viewpoint of scratch resistance. When the average particle size of the resin beads is within the above range, the plate tone transfer is improved and ink stability can be improved. The average particle size of the resin beads is the cumulative 50% particle size on a volume basis measured by laser diffraction / light scattering method.

[0034] (Silicone resin) The silicone resin is used to improve the water abrasion resistance and heat resistance of the resulting coating film. The silicone resin is a compound having a siloxane bond.

[0035] Examples of silicone resins include polyether-modified silicones, and other examples include polyorganosiloxanes such as polydimethylsiloxane. The polyorganosiloxane may be partially modified with an organic group or may not be modified. In addition, it is preferable because it improves solubility and dispersibility in an aqueous medium. The polyorganosiloxane may be reactive or non-reactive, but it is preferable that it is reactive when used in combination with a curing agent described later. In this specification, polyorganosiloxanes partially modified with organic groups are also referred to as "modified polyorganosiloxanes."

[0036] An example of the modified polyorganosiloxane is a polyorganosiloxane in which at least one methyl group in a polydimethylsiloxane is substituted with a monovalent group other than an alkyl group (hereinafter also referred to as an "organic group"). In this embodiment, at least one terminal methyl group and a side chain methyl group may be substituted with an organic group, at least one terminal methyl group may be substituted with an organic group and the side chain methyl group may not be substituted with an organic group, or at least one side chain methyl group may be substituted with an organic group and the terminal methyl group may not be substituted with an organic group. Among these, it is preferable that at least one side chain methyl group is substituted with an organic group and the terminal methyl group is not substituted with an organic group.

[0037] Examples of the organic group include an organic group having an ether group, an organic group having an amino group, an organic group having an epoxy group (including a cyclic epoxy group), an organic group having an ester group, an organic group having an aryl group such as a phenyl group, an organic group having a hydroxyl group, an organic group having a mercapto group, an organic group having a carboxy group, an organic group having a (meth)acryloyloxy group, an organic group having an alkoxy group, and an organic group having an amide group. The silicone resin may have one or more types of organic groups.

[0038] That is, examples of modified polyorganosiloxanes include polyether-modified polyorganosiloxanes, amino-modified polyorganosiloxanes (amine-modified silicones), epoxy-modified polyorganosiloxanes, polyester-modified polyorganosiloxanes, polyetherester-modified polyorganosiloxanes, aryl-modified polyorganosiloxanes, hydroxyl-modified polyorganosiloxanes, mercapto-modified polyorganosiloxanes, carboxy-modified polyorganosiloxanes, (meth)acryloyloxy-modified polyorganosiloxanes (silicone-modified acrylics), alkoxy-modified polyorganosiloxanes, amide-modified polyorganosiloxanes, etc. Among these, amino-modified polyorganosiloxanes, (meth)acryloyloxy-modified polyorganosiloxanes, and polyether-modified silicones are preferred. These silicone resins may be used alone or in combination of two or more.

[0039] As the silicone resin, commercially available products may be used, for example, those manufactured by BYK under the trade names "BYK302", "BYK-307", "BYK313", "BYK322", "BYK323", "BYK325N", "BYK326", "BYK327", "BYK330", "BYK331", "BYK-333", "BYK342", "BYK-345", "BYK-346", "BYK347", "BYK-348", "BYK349", "BYK-375", "BYK377", "BYK378", "BYK3450", "BYK3451", "BYK3455", "BYK3456", "BYK3760", "BYK3550", "BYK SILCLEAN 3700", "BYK SILCLEAN 3701", and "BYK SILCLEAN 3720"; trade names of Shin-Etsu Chemical Co., Ltd.: "KF-351A", "KF-352A", "KF-353", "KF-354L", "KF-355A", "KF-615A", "KF-945", "KF-640", "KF-642", "KF-643", "KF-6020", "X-22-4515", "KF-868", "KF-865", "KF-864", "KF-859", "KF-393", "KF-860", "KF-880", "KF-8004", "KF-8002", "KF-8005", "KF-867", "KF-869", "KF-861", "X-22-343", "KF-101", "KF-1001", "X-22-2000", and "X-22-3820" W”, “X-22-3939A”, “KP-124”, “KP-109”, “KP-110”, “KP-121”, “KP-118”, “KP-341”, “KP-11” 2'', ``KP-125'', ``KP-101'', ``KP-106'', ``KP-126'', ``KP-360A'''', ``KP-361'', ``KP-390'', ``KP-391'', "KP-392", "PAM-E", "KF-8010", "X-22-161A", "X-22-161B", "KF-8012", "KF-8008", "POLON" -MF-14'', ``POLON-MF-14E'', ``POLON-MF-51'', ``POLON-MF-14EC'', ``POLON-MF-63'', ``KM-9771'';Product names manufactured by Dow Toray: "DOWSIL 501W Additive", "DOWSIL FZ-2104 Fluid", "DOWSIL FZ-2110", "DOWSIL FZ-2123", "DOWSIL FZ-2164", "DOWSIL FZ-2191", "DOWSIL FZ-5609 Fluid", "DOWSIL "DOWSIL L-7001", "DOWSIL L-7002", "DOWSIL L-7604", "DOWSIL OFX-0309 Fluid", "DOWSIL OFX-5221 Fluid", "DOWSIL SF-8410 Fluid", "DOWSIL OFX-0193 Fluid", "DOWSIL SH-3746 Fluid", "DOWSIL SH-3771 "DOWSIL SH-8400 Fluid", "DOWSIL SH-8700 Fluid", "DOWSIL Y-7006", "DOWSIL FZ-2203", "DOWSIL FZ-2215, DOWSIL FZ-2222, DOWSIL BY16-205, DOWSIL BY16-213, DOWSIL BY16-849 Fluid, DOWSIL BY16-853U, DOWSIL BY16-871, DOWSIL BY16-872, DOWSIL BY16-879B, DOWSIL BY16-892, DOWSIL FZ-3705, DOWSIL FZ-3710 Fluid, DOWSIL FZ-3785, DOWSIL SF-8417 Fluid; and the trade name "Tegoglide 482" manufactured by EVONIK.

[0040] The silicone resin may be in the form of a solid, an oil, an emulsion, or a dispersion. The silicone resin may be copolymerized with an acrylic resin skeleton, which increases the compatibility with the acrylic emulsion resin (A) and the acrylic emulsion resin (B).

[0041] (additives) Examples of additives include waxes, thickeners, anti-settling agents, ultraviolet absorbers, antioxidants, leveling agents, viscoelasticity modifiers, antifoaming agents, lubricants, dispersants, stabilizers, pH adjusters, and surfactants. These additives may be used alone or in combination of two or more. It is preferable that the aqueous ink composition be substantially free of colorants such as pigments other than titanium oxide and precipitated barium sulfate. Here, "substantially free of colorants" means that colorants are not intentionally blended, except for those that are unintentionally contained.

[0042] Examples of waxes include polyolefin waxes (polyethylene wax, polypropylene wax, etc.), polytetrafluoroethylene wax, Fischer-Tropsch wax, amide wax, microcrystalline wax, montan wax, carnauba wax, paraffin wax, beeswax, etc. Among these, polyolefin waxes are preferred, and polyethylene wax is more preferred.

[0043] Commercially available polyethylene waxes include those manufactured by Mitsui Chemicals under the trade names "Chemipearl W100," "Chemipearl W200," "Chemipearl W300," "Chemipearl W308," "Chemipearl W400," "Chemipearl W401," "Chemipearl W500," "Chemipearl W640," "Chemipearl W700," and "Chemipearl W800"; those manufactured by BYK under the trade names "CERAFLOUR925," "CERAFLOUR925N," "CERAFLOUR927N," and "CERAFLOUR929"; Examples include "CERAFLOUR929N", "CERAFLOUR950", "CERAFLOUR960", "CERAFLOUR961", "CERAFLOUR988", "CERAFLOUR991", "CERAFLOUR1000", "AQUACER531", "AQUACER537", "AQUACER552", "AQUACER840", "AQUACER1547", and "AQUAMAT208"; and "JonCrylwax 4" (a product name manufactured by BASF Japan). These waxes may be used alone or in combination of two or more.

[0044] The thickener is used to adjust the viscosity of the aqueous ink composition. Examples of thickeners include urethane-based thickeners, polyacrylic-based thickeners, polyamide-based thickeners, cellulose-based thickeners, and clay minerals such as bentonite. Among these, urethane-based thickeners are more preferred. Urethane thickeners are so-called associative thickeners, and exhibit effective thickening properties in aqueous media by the association of urethane bonds. Examples of urethane thickeners (urethane associative thickeners) include compounds that have urethane bonds and polyether chains in their molecules and have hydrophobic groups at their ends. Commercially available urethane thickeners include those manufactured by San Nopco under the trade names "SN Thickener 612," "SN Thickener 621N," "SN Thickener 625N," "SN Thickener 627N," and "SN Thickener 660T." These thickeners may be used alone or in combination of two or more.

[0045] The defoaming agent is used to defoam the aqueous ink composition. The anti-foaming agent includes a mixture of silicone and hydrophobic particulates. Commercially available mixtures of silicone and hydrophobic microparticles include those manufactured by BYK under the trade names "BYK-011", "BYK-012", "BYK-014", "BYK-015", "BYK-017", "BYK-018", "BYK-019", "BYK-021", "BYK-022", "BYK-023", "BYK-024", "BYK-025", "BYK-028", "BYK-038", "BYK-039", "BYK-044", "BYK-093", and BYK-094", "BYK-1610", "BYK-1611", "BYK-1615", "BYK-1617", "BYK-1640", "BYK-1650", "BYK-1710", "BYK-1711", "BYK-1 719'', ``BYK-1723'', ``BYK-1724'', ``BYK-1730'', ``BYK-1740'', ``BYK-1770'', ``BYK-1780'', ``BYK-1781'', ``BYK-1785'', ``BYK-1786'' "BYK-1798": Trade names of San Nopco products: "SN Deformer 121N", "SN Deformer 1311", "SN Deformer 1312", "SN Deformer 1313", "SN Deformer 1314", "SN Deformer 1315", "SN Deformer 1316", "SN Deformer 154", "SN Deformer 154S", "SN Deformer 180", "SN Deformer 265", "SN Deformer 317", "SN Deformer Examples of SN Deformer products include "SN Deformer 380", "SN Deformer 381", "SN Deformer 391", "SN Deformer 393", "SN Deformer 395", "SN Deformer 399", "SN Deformer 5016", "SN Deformer 5016", "Nopco DF-122-NS", "Noptam 3590", "Noptam 6030PC", "Noptam 777-F", "Noptam 8000PC", "Noptam 8034-F", and "Noptam 8034-LF". These antifoaming agents may be used alone or in combination of two or more.

[0046] The dispersant is used to enhance the dispersibility of the titanium oxide and precipitated barium sulfate in the aqueous ink composition. Dispersants include copolymers that have an affinity for titanium oxide and precipitated barium sulfate. Commercially available dispersants include those manufactured by BYK under the trade names "ANTI-TERRA-250", "DISPERBYK-102", "DISPERBYK-180", "DISPERBYK-184", "DISPERBYK-185", "DISPERBYK-187", "DISPERBYK-190", "DISPERBYK-191", "DISPERBYK-192", "DISPERBYK-193", "DISPERBYK-194N", "DISPERBYK-199", "DISPERBYK-2010", "DISPERBYK-2012", "DISPERBYK-2013", "DISPERBYK-2015", "DISPERBYK-2019", "DISPERBYK-2055", "DISPERBYK-2060", and "DISPERBYK-2065". 061", "DISPERBYK-2081", "DISPERBYK-2096", "BYK-154"; and trade names manufactured by Lubrizol include "Solsperse 20000", "Solsperse 40000", "Solsperse 43000", "Solsperse 27000", "Solsperse 40000", "Solsperse 41000", "Solsperse 43000", "Solsperse 44000", "Solsperse 45000", "Solsperse 46000", "Solsperse 47000", "Solsperse 53095", "Solsperse 64000", "Solsperse 65000", "Solsperse 66000", "Solsperse W100", "Solsperse W200", "Solsperse W320", "Solsperse WV400", and "Solsperse J400". These dispersants may be used alone or in combination of two or more.

[0047] Examples of pH adjusters include aqueous ammonia, sodium hydroxide, potassium hydroxide, and various amines. These pH adjusters may be used alone or in combination of two or more.

[0048] <Content of each ingredient> The solid content of the acrylic emulsion resin (A) is preferably 0.36 to 20% by mass, and more preferably 1.5 to 12% by mass, based on the solid content of the aqueous ink composition, from the viewpoint of abrasion resistance and heat resistance. When the solid content of the acrylic emulsion resin (A) is within the above range, the abrasion resistance and heat resistance are likely to be improved.

[0049] The solid content of the acrylic emulsion resin (B) is preferably 7.5% by mass or more and 39% by mass or less, based on the solid content of the aqueous ink composition, and more preferably 15% by mass or more and 23% by mass or less, from the viewpoint of improving abrasion resistance and heat resistance. When the solid content of the acrylic emulsion resin (B) is within the above range, the abrasion resistance and heat resistance are likely to be improved.

[0050] The total content of the solids of the acrylic emulsion resin (A) and the acrylic emulsion resin (B) is from 15% by mass to 40% by mass, preferably from 20% by mass to 40% by mass, and more preferably from 20% by mass to 35% by mass, relative to the total mass of the solids of the aqueous ink composition, from the viewpoint of excellent abrasion resistance, heat resistance, water abrasion resistance, and scratch resistance. When the total content of the solids of the acrylic emulsion resin (A) and the acrylic emulsion resin (B) relative to the total mass of the solids of the aqueous ink composition is at least the lower limit, the abrasion resistance, water abrasion resistance, scratch resistance, and heat resistance of the resulting coating film are likely to be improved. When the total content of the solids of the acrylic emulsion resin (A) and the acrylic emulsion resin (B) is at most the upper limit, the abrasion resistance and heat resistance of the resulting coating film are likely to be improved. If the total content of the solids of the acrylic emulsion resin (A) and the acrylic emulsion resin (B) is less than 15% by mass relative to the total mass of the solids of the aqueous ink composition, the viscosity stability and scratch resistance will be poor, and if it exceeds 40% by mass, the heat resistance will be poor.

[0051] The mass ratio of the solid content of the acrylic emulsion resin (A) to the solid content of the acrylic emulsion resin (B), acrylic emulsion resin (A):acrylic emulsion resin (B), is 1:1.0 to 1:40, preferably 1:1.5 to 1:30, and more preferably 1:1.5 to 1:20 from the viewpoint of particularly excellent abrasion resistance and heat resistance. When the mass ratio is equal to or greater than the lower limit, the abrasion resistance is improved, whereas when the mass ratio is equal to or less than the upper limit, the pigment dispersibility, viscosity stability, substrate adhesion, abrasion resistance, water abrasion resistance, scratch resistance, and heat resistance are likely to be improved. If the ratio of acrylic emulsion resin (B) in the acrylic emulsion resin (A):acrylic emulsion resin (B) is less than 1.0, the abrasion resistance will be poor, and if it exceeds 40, the viscosity stability will be poor.

[0052] The total content of titanium oxide and precipitated barium sulfate is preferably 10 to 60 mass% relative to the total mass of the aqueous ink composition, more preferably 15 to 60 mass%, even more preferably 20 to 60 mass%, and particularly preferably 25 to 60 mass% from the viewpoint of the balance between color development and substrate adhesion. The total content of titanium oxide and precipitated barium sulfate is preferably 25 to 80 mass% relative to the total mass of the solids in the aqueous ink composition, more preferably 30 to 80 mass%, even more preferably 40 to 80 mass%, and particularly preferably 50 to 80 mass% from the viewpoint of the balance between color development and substrate adhesion. When the total content of titanium oxide and precipitated barium sulfate is equal to or greater than the lower limit, the coating film tends to have a high uniformity and excellent opacity. When the total content of titanium oxide and precipitated barium sulfate is equal to or less than the upper limit, the pigment dispersibility of the aqueous ink composition tends to be improved.

[0053] The content of the aqueous medium is preferably 20 to 60% by mass, more preferably 25 to 55% by mass, and even more preferably 30 to 50% by mass, based on the total mass of the aqueous ink composition. When the content of the aqueous medium is equal to or greater than the lower limit, the fluidity of the aqueous ink composition is improved, and when it is equal to or less than the upper limit, the drying properties of the coating film of the aqueous ink composition are improved. The content of the organic solvent is preferably 0 to 5% by mass, more preferably 0 to 4% by mass, and even more preferably 0 to 3% by mass, relative to the total mass of the aqueous ink composition. When the content of the organic solvent is equal to or less than the upper limit, for example, drying does not occur too quickly during flexographic printing, and printing defects such as plate entanglement are suppressed.

[0054] The content of optional components other than the aqueous medium is not particularly limited as long as it is within a range that does not impair the effects of the present invention, but for example, it is preferably 0 to 10 mass % and more preferably 0 to 5 mass % relative to the total mass of the aqueous ink composition. The content of optional components other than the aqueous medium is preferably 0 to 15% by mass, more preferably 0 to 10% by mass, based on the total mass of the solid content of the aqueous ink composition.

[0055] When the aqueous ink composition contains resin beads as an optional component, the solid content of the resin beads is preferably from 0.05 to 3% by mass, more preferably from 0.05 to 1% by mass, relative to the total mass of the aqueous ink composition, and even more preferably from 0.1 to 0.8% by mass, from the viewpoint of achieving a particularly excellent balance between substrate adhesion and scratch resistance. When the aqueous ink composition contains resin beads as an optional component, the solid content of the resin beads is preferably from 0.1 to 6% by mass, more preferably from 0.3 to 5% by mass, relative to the total mass of the solid contents of the aqueous ink composition, and even more preferably from 0.5 to 2% by mass, from the viewpoint of achieving a particularly excellent balance between substrate adhesion and scratch resistance. When the content of the resin beads is within the above range, the abrasion resistance, water abrasion resistance, and scratch resistance of the resulting coating film are likely to be improved.

[0056] When the aqueous ink composition contains a silicone-based resin as an optional component, the solid content of the silicone-based resin is preferably from 0.05 to 3 mass% relative to the total mass of the aqueous ink composition, more preferably from 0.05 to 1 mass%, and even more preferably from 0.1 to 0.8 mass% from the viewpoint of achieving a particularly excellent balance between water abrasion resistance and heat resistance. When the aqueous ink composition contains a silicone-based resin as an optional component, the solid content of the silicone-based resin is preferably from 0.1 to 6% by mass, more preferably from 0.3 to 5% by mass, and even more preferably from 0.5 to 2% by mass, relative to the total mass of the solid contents of the aqueous ink composition, from the viewpoint of achieving a particularly excellent balance between water abrasion resistance and heat resistance. When the content of the silicone resin is within the above range, the water abrasion resistance and heat resistance of the resulting coating film tend to be improved.

[0057] When the aqueous ink composition contains a wax as an optional component, the solid content of the wax is preferably 0.1 to 10 mass %, more preferably 0.2 to 5 mass %, and even more preferably 0.3 to 2 mass %, relative to the total mass of the aqueous ink composition. When the aqueous ink composition contains a wax as an optional component, the solid content of the wax is preferably 0.2 to 20 mass%, more preferably 0.5 to 15 mass%, and even more preferably 1 to 10 mass%, relative to the total mass of the solid contents of the aqueous ink composition.

[0058] When the aqueous ink composition contains a thickener as an optional component, the solid content of the thickener is preferably 0.01 to 4 mass%, more preferably 0.03 to 2 mass%, and even more preferably 0.08 to 1 mass%, relative to the total mass of the aqueous ink composition. When the aqueous ink composition contains a thickener as an optional component, the solid content of the thickener is preferably 0.02 to 7 mass%, more preferably 0.05 to 4 mass%, and even more preferably 0.1 to 2 mass%, relative to the total mass of the solid contents of the aqueous ink composition. When the solids content of the thickener is equal to or greater than the above lower limit, the effect of the thickener is fully exerted and the viscosity of the aqueous ink composition can be easily adjusted to a desired value, whereas when the solids content is equal to or less than the above upper limit, the physical properties of the aqueous ink composition can be maintained well.

[0059] When the aqueous ink composition contains an antifoaming agent as an optional component, the solid content of the antifoaming agent is preferably 0.005 to 2 mass%, more preferably 0.01 to 1 mass%, and even more preferably 0.05 to 0.8 mass%, relative to the total mass of the aqueous ink composition. When the aqueous ink composition contains an antifoaming agent as an optional component, the content of the antifoaming agent in solids is preferably 0.005 to 4 mass%, more preferably 0.01 to 2 mass%, and even more preferably 0.05 to 1 mass%, relative to the total mass of the solids of the aqueous ink composition.

[0060] <Method for producing water-based ink composition> The aqueous ink composition of this embodiment can be obtained, for example, by mixing an acrylic emulsion resin (A), an acrylic emulsion resin (B), one or both of titanium oxide and precipitated barium sulfate, and, if necessary, one or more optional components, so that the components are present in the desired amounts. The method for mixing the components is not particularly limited, and the components can be mixed by various methods. In one embodiment, it is preferable to prepare a mill-base composition in advance by mixing the acrylic emulsion resin (A), either or both of titanium oxide and precipitated barium sulfate, and an aqueous medium, and then add the acrylic emulsion resin (B) to produce the aqueous ink composition.

[0061] <Applications of water-based ink compositions> The aqueous ink composition of this embodiment is suitable as a white ink composition for printing by gravure printing or flexographic printing on the surface of a substrate such as a plastic substrate or a paper substrate, or on the surface of a color ink layer formed on the surface of a substrate. In particular, it is suitable as a white ink composition for printing by flexographic printing on the surface of a substrate, or on the surface of a color ink layer formed on the surface of a substrate. In other words, the aqueous ink composition of this embodiment is suitable for flexographic printing. The aqueous ink composition of this embodiment is preferably used together with a curing agent, which will be described later.

[0062] <Water-based ink> The aqueous ink composition comprises the aqueous ink composition of the present invention and may contain other optional components. The aqueous ink can be obtained by combining the composition with optional additives and toning the color.

[0063] <Mechanism of action> The aqueous ink composition of the present invention contains two acrylic emulsion resins with different acid values, each with an acid value of 40 mgKOH / g as the boundary. As shown in the examples below, an aqueous ink composition containing only one of the acrylic emulsion resins does not achieve the desired physical properties of the aqueous ink composition and the physical properties of the coating. In contrast, the aqueous ink composition of the present invention improves both the physical properties of the aqueous ink composition and the physical properties of the coating due to the synergistic effect of combining two acrylic emulsion resins with different acid values, each with an acid value of 40 mgKOH / g as the boundary. Furthermore, in the present invention, the improvement in the physical properties of the aqueous ink composition and the physical properties of the coating are further enhanced by adjusting the total content and mass ratio of the two acrylic emulsion resins with different acid values, each with an acid value of 40 mgKOH / g as the boundary. For example, using only one acrylic emulsion resin with an acid value of less than 40 mgKOH / g or only one acrylic emulsion resin with an acid value of 40 mgKOH / g or more is particularly poor in adhesion to the substrate, which is an undesirable embodiment.

[0064] <Curing agent> The aqueous ink composition of this embodiment may be used together with a curing agent. For example, the aqueous ink composition and the curing agent may be mixed to prepare a coating liquid, and the resulting coating liquid may be applied to a substrate. Use of a curing agent further improves the coating film properties such as water resistance and abrasion resistance of the coating layer, as well as adhesion to the substrate.

[0065] As the curing agent, those known in the art can be used, such as isocyanate-based curing agents, blocked isocyanate-based curing agents, carbodiimide-based curing agents, oxazoline-based curing agents, epoxy-based curing agents, aziridine-based curing agents, etc. Among these, isocyanate-based curing agents, epoxy-based curing agents, and aziridine-based curing agents are preferred from the viewpoint of further improving the abrasion resistance of the coating layer. These curing agents may be used alone or in combination of two or more.

[0066] Specific examples of the isocyanate curing agent include aliphatic, alicyclic, aromatic, etc. polyvalent isocyanate compounds. Specific examples of the polyvalent isocyanate compound include aliphatic diisocyanates such as trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, 1,2-propylene diisocyanate, 1,2-butylene diisocyanate, 2,3-butylene diisocyanate, 1,3-butylene diisocyanate, 2,4,4- or 2,2,4-trimethylhexamethylene diisocyanate, and 2,6-diisocyanate methyl caproate; hydrogenated diisocyanates; Diphenylmethane diisocyanate, isophorone diisocyanate, norbornene diisocyanate, 1,3-cyclopentane diisocyanate, 1,4-cyclohexane diisocyanate, 1,3-cyclohexane diisocyanate, 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate (isophorone diisocyanate), 4,4'-methylenebis(cyclohexyl isocyanate), methyl-2,4-cyclohexane diisocyanate, methyl-2,6-cyclohexyl Alicyclic diisocyanates such as hexane diisocyanate, 1,4-bis(isocyanatemethyl)cyclohexane, and 1,3-bis(isocyanatemethyl)cyclohexane; m-phenylene diisocyanate, p-phenylene diisocyanate, 4,4'-diphenyl diisocyanate, 1,5-naphthalene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4- or 2,6-tolylene diisocyanate, 4,4'-toluidine diisocyanate, and dianisidine diisocyanate; Examples of suitable isocyanates include aromatic diisocyanates such as 4,4'-diphenyl ether diisocyanate; polyisocyanate compounds obtained by polymerizing the above diisocyanates and having an allophanate structure, a nurate structure, a biuret structure, or the like; triisocyanates such as 1,3,5-triisocyanate benzene, 2,4,6-triisocyanate toluene, and 1,3,5-triisocyanate hexane; and polyisocyanates such as 4,4'-diphenyldimethylmethane-2,2'-5,5'-tetraisocyanate.

[0067] Commercially available isocyanate curing agents include those manufactured by Mitsui Chemicals under the product names "Takenate WD-720," "Takenate WD-725," "Takenate WD-726," "Takenate WD-730," "Takenate WD-220," "Takenate XWD-HS7," and "Takenate XWD-HS30"; those manufactured by Nippon Polyurethane Industries Co., Ltd. under the product names "Aquanate 100," "Aquanate 110," "Aquanate 200," and "Aquanate 210"; those manufactured by Asahi Kasei under the product names "Duranate WB40-100," "Duranate WB40-80D," "Duranate WT20-100," "Duranate WT30-100," "Duranate WL70-100," "Duranate WR80-70P," and "Duranate WE50-100"; and those manufactured by Bayer MaterialScience under the product name "Bayhydur 3100", "Bayhydur 302", "Bayhydur 304", "Bayhydur 305", "Bayhydur XP2451 / 1", "Bayhydur XP2487 / 1", "Bayhydur XP2547", "Bayhydur XP2655", "Bayhydur XP2700"; and BASF products under the names "Basonat HW100", "Basonat HA100", and "Basonat HW1180PC". The isocyanate curing agent may be used alone or in combination of two or more kinds.

[0068] Specific examples of blocked isocyanate curing agents include isocyanate curing agents blocked with a blocking agent (e.g., alcohol compounds, phenol compounds, oxime compounds, lactam compounds, pyrazole compounds, active methylene compounds, etc.). These blocked isocyanate curing agents may be used alone or in combination of two or more.

[0069] A carbodiimide curing agent is a compound containing two or more carbodiimide groups in one molecule. Specific examples of carbodiimide curing agents include poly(4,4'-diphenylmethanecarbodiimide), poly(dicyclohexylmethanecarbodiimide), and poly(diisopropylcarbodiimide). Commercially available carbodiimide curing agents include the "Carbodilite" series manufactured by Nisshinbo Chemical Inc. These carbodiimide curing agents may be used alone or in combination of two or more.

[0070] Oxazoline-based curing agents are compounds containing two or more oxazoline groups per molecule. Specific examples of oxazoline-based curing agents include polyhydric oxazolines such as 2,2'-bis-(2-oxazoline), 2,2'-methylene-bis-(2-oxazoline), and 2,2'-(1,4-phenylene)-bis(2-oxazoline), as well as polymers or copolymers containing oxazoline-group-containing monomer units such as 2-vinyl-2-oxazoline, 2-vinyl-5-methyl-2-oxazoline, and 2-isopropenyl-5-ethyl-2-oxazoline. Each oxazoline-group-containing monomer may be used alone, or two or more types may be used. Furthermore, copolymers of an oxazoline-group-containing monomer with another monomer copolymerizable with this monomer may also be used. Commercially available oxazoline-based curing agents include the "Epocross" series manufactured by Nippon Shokubai Co., Ltd. These oxazoline-based curing agents may be used alone or in combination of two or more.

[0071] Epoxy curing agents are compounds containing two or more epoxy groups per molecule. Specific examples of epoxy curing agents include bisphenol A epoxy compounds, bisphenol F epoxy compounds, triglycidyl aminophenol, biphenyl diglycidyl ether, triglycidyl isocyanurate, polyglycidyl (meth)acrylate, and copolymers of glycidyl (meth)acrylate with vinyl monomers copolymerizable therewith. Commercially available epoxy curing agents include the "jER" series manufactured by Mitsubishi Chemical Corporation and the "Denacol EX" series manufactured by Nagase ChemteX Corporation. These epoxy-based curing agents may be used alone or in combination of two or more.

[0072] Aziridine curing agents are compounds containing two or more aziridine groups per molecule. Specific examples of aziridine curing agents include 2,2-bishydroxymethylbutanol-tris[3-(1-aziridinyl)propionate] and 4,4'-bis(ethyleneiminocarbonylamino)diphenylmethane. Commercially available aziridine curing agents include the "ChemiTite" series manufactured by Nippon Shokubai Co., Ltd. These aziridine-based curing agents may be used alone or in combination of two or more.

[0073] When the aqueous ink composition and the curing agent are used in combination, they are preferably mixed so that the solid content of the curing agent is 0.1 to 10 parts by mass, more preferably 0.3 to 7 parts by mass, and even more preferably 0.5 to 5 parts by mass, per 100 parts by mass of the solid content of the aqueous ink composition. When the ratio of the curing agent is equal to or greater than the lower limit, the curing reaction proceeds sufficiently, and when it is equal to or less than the upper limit, the water resistance of the printed layer is further improved.

[0074] <Kit> A kit according to one embodiment of the present invention independently contains the above-described water-based ink composition of the present invention and the above-described curing agent. Here, "independently" means that the aqueous ink composition and the curing agent are present in a state where they are not in contact with each other; for example, the kit includes a first container containing the aqueous ink composition and a second container containing the curing agent.

[0075] The second container may contain ingredients other than the curing agent (other ingredients). The other components include, for example, solvents and stabilizers. Examples of the solvent include the aqueous media exemplified above in the description of the aqueous ink composition.

[0076] When using the kit, the aqueous ink composition and the curing agent are mixed together. The mixing ratio when mixing the aqueous ink composition and the curing agent is as described above.

[0077] <Laminate> An example of a laminate according to one embodiment of the present invention is shown in Figures 1 and 2. Note that the dimensional ratios in Figures 1 and 2 are different from the actual ones for the sake of convenience of explanation. The laminate 10 in FIG. 1 is a printed matter comprising a substrate 11 and a printed layer 12 provided on one surface of the substrate 11. The laminate 20 in Figure 2 is a printed matter comprising a substrate 21, a first printed layer 22 provided on one side of the substrate 21, and a second printed layer 23 provided on the side of the first printed layer opposite the substrate. When the laminate is attached to a packaging container as a label, it is preferable to attach the base materials 11 and 21 on the outside of the printed layer 12 and the second printed layer 23, i.e., so that the printed layer 12 and the second printed layer 23 are on the inside (the side that contacts the packaging container). Additionally, when the laminate is used as a packaging material for food or the like, it is preferable to package the base materials 11 and 21 on the inside of the printed layer 12 and the second printed layer 23, i.e., so that the printed layer 12 and the second printed layer 23 are on the outside (the side that does not contact the contents). Alternatively, another printed layer may be provided on the surface of the substrate 11 or 21 by printing a composition containing a matting agent, such as a varnish composition or an extender pigment. Here, the surface of the substrate 11 refers to the surface of the substrate 11 opposite to the surface on which the printed layer 12 is provided. The surface of the substrate 21 refers to the surface of the substrate 21 opposite to the surface on which the first printed layer 22 is provided. The surface of the substrate 11 on which the printed layer 12 is provided is referred to as the back surface of the substrate 11, and the surface of the substrate 21 on which the first printed layer 22 is provided is referred to as the back surface of the substrate 21. Alternatively, another printed layer may be provided on the surface of the printed layer 12 or the second printed layer 23 by printing a composition containing a matting agent, such as a varnish composition or an extender pigment. Here, the surface of the printed layer 12 refers to the surface of the printed layer 12 opposite to the surface on which the substrate 11 is provided. The surface of the second printed layer 23 refers to the surface of the second printed layer 23 opposite to the surface on which the printed layer 22 is provided.

[0078] <Base material> The type of substrates 11 and 21 can be appropriately selected depending on the type of laminates 10 and 20, etc., and is not particularly limited, but a plastic substrate or a paper substrate is preferred. For example, when the laminates 10 and 20 are used as paper labels, the substrates 11 and 12 are preferably paper substrates. For example, when the laminates 10 and 20 are used as heat-shrinkable labels (shrink labels), the substrates 11 and 21 are preferably heat-shrinkable films (shrink films). When the laminates 10 and 20 are used as roll labels, the substrates 11 and 21 are preferably polyethylene terephthalate (PET) films or biaxially oriented PP films (OPP films). When the laminates 10 and 20 are used as stretch labels, the substrates 11 and 21 are preferably stretch films. Among these, the substrates 11 and 21 are preferably heat-shrinkable films, polyethylene terephthalate (PET) films, or biaxially oriented PP films.

[0079] Examples of plastic substrates include polyester films such as polyethylene terephthalate (PET), amorphous polyethylene terephthalate (A-PET), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), and polylactic acid; polyolefin films such as low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), high-density polyethylene (HDPE), and polypropylene (PP); cellulose films such as cellophane; polystyrene (PS) film; ethylene-vinyl acetate copolymer resin film; ethylene-vinyl alcohol copolymer resin film; polyamide (Ny) film; polycarbonate film; polyimide film; and polyvinyl chloride film. These films can be appropriately selected depending on the application. For example, when the laminates 10 and 20 are used as heat-shrinkable labels (shrink labels), the substrates 11 and 21 are preferably uniaxially shrinkable polystyrene film, uniaxially shrinkable PET film, uniaxially shrinkable polyolefin film, or uniaxially shrinkable polyvinyl chloride film. For example, either stretched or unstretched plastic films such as biaxially stretched PP films and unstretched PP films can be used as the substrates 11 and 21. The surfaces of the substrates 11 and 21 may be subjected to surface treatment such as corona discharge treatment, plasma treatment, flame treatment, or solvent treatment.

[0080] The substrates 11 and 21 may have a single layer structure or a laminate structure. That is, the substrates 11 and 21 may be a single layer film or a laminate film. When the substrates 11 and 21 are laminate films, they may be configured by laminating two or more films of the same type, or by laminating two or more films of different types. Examples of preferred film combinations include a combination in which a polyester film is on the front side of the substrates 11 and 21 and a polystyrene film or a polyolefin film is on the back side of the substrates 11 and 21, and a combination in which a cyclic polyolefin film is on the front side of the substrates 11 and 21 and a polyethylene film or a polypropylene film is on the back side of the substrates 11 and 21.

[0081] The thickness of the substrates 11 and 21 is preferably 5 to 100 μm, more preferably 12 to 60 μm, and even more preferably 12 to 50 μm.

[0082] <Printed layer, second printed layer> In the laminate 10, the printed layer 12 is provided on one surface of the substrate 11. In the laminate 20, the second printed layer 23 is provided on the surface opposite to the substrate 21 of the first printed layer 22 provided on one surface of the substrate 21. The printed layer 12 and the second printed layer 23 are printed layers (W) formed using the water-based ink or kit of the present embodiment described above. In the present invention, the printed layer 12, which is a printed layer (W) formed using the water-based ink or kit, is also referred to as the "printed coating film (W)," and the second printed layer 23 is also referred to as the "second printed coating film (W)." The thickness of the printed layer 12 and the second printed layer 23 is preferably 0.2 to 3.0 μm, more preferably 0.3 to 2.0 μm, and even more preferably 0.3 to 1.5 μm.

[0083] <First printing layer> In the laminate 20, the first printed layer 22 is provided on one surface of the substrate 21. The first printed layer 22 is a printed layer (C) (hereinafter also referred to as "color printed layer (C)" or "printed coating film (C)") formed using an ink composition in order to impart design, functionality, etc. to the laminate 20. The first printed layer 22 may have a single layer structure or a laminated structure. The total thickness of the first printed layer 22 is preferably 0.2 to 15 μm, more preferably 0.3 to 10 μm, and even more preferably 0.3 to 8 μm.

[0084] The ink composition used to form the first print layer 22 contains a color pigment. The ink composition is preferably an aqueous ink composition. The aqueous ink composition is not particularly limited, and any known composition can be used, including, for example, a composition containing an aqueous binder resin, an aqueous medium, a color pigment, and, if necessary, other components. As the aqueous binder resin, any aqueous binder resin known in the art can be used. Examples of the aqueous medium include the aqueous media exemplified above in the description of the aqueous ink composition of the present invention. Examples of color pigments include organic pigments such as azo pigments (monoazo, condensed azo, etc.), threne pigments (anthraquinone, perinone, perylene, thioindigo, etc.), phthalocyanine pigments (phthalocyanine blue, phthalocyanine green, etc.), quinacridone pigments, dioxazine pigments, isoindolinone pigments, pyrrolopyrrole pigments, aniline black, and organic fluorescent pigments; and inorganic pigments such as natural products (clay, etc.), ferrocyanides (princess blue, etc.), sulfides (zinc sulfide, etc.), sulfates, oxides (chromium oxide, zinc oxide, iron oxide, etc.), hydroxides (aluminum hydroxide, etc.), silicates (ultramarine, etc.), carbonates, carbon (carbon black, graphite, etc.), metal powders (aluminum powder, bronze powder, zinc powder, etc.), and calcined pigments. Other examples of color pigments include the aforementioned titanium oxide and precipitated barium sulfate. Examples of other ingredients include waxes, dispersants, antifoaming agents, lubricants, pH adjusters, thickeners, and the like.

[0085] <Method of manufacturing laminate> The method for producing the laminate 10 of FIG. 1 includes a step of forming a printed layer 12 on one surface of a substrate 11 using the water-based ink or kit of this embodiment. The manufacturing method of the laminate 20 of Figure 2 includes a step (1) of forming a first printed layer 22 on one side of a substrate 21 using an ink composition, and a step (2) of forming a second printed layer 23 on the side of the first printed layer 22 opposite the substrate 21 using the water-based ink or kit of this embodiment.

[0086] In the method for producing the laminate 10 of FIG. 1, for example, the water-based ink of this embodiment is applied to one surface of the substrate 11 and dried to form the printed layer 12. When forming the printed layer 12 using the kit of this embodiment, the aqueous ink and the curing agent included in the kit are mixed to prepare a mixture (M), and the resulting mixture (M) is applied to one surface of the substrate 11 and dried to form the printed layer 12. The mixing ratio of the aqueous ink and the curing agent when mixing them is as described above. In addition, after the water-based ink or mixture (M) is applied to one surface of the substrate 11 and dried to form the printed layer 12, further water-based ink or mixture (M) may be applied (recoated).

[0087] The method for applying the aqueous ink or mixture is not particularly limited, and known application methods can be used, such as gravure printing, flexographic printing, brush coating, gravure coating, die coating, bar coating, spray coating, flow coating, dip coating, spin coating, curtain coating, etc. Among these, flexographic printing is preferred because of its high quality and productivity.

[0088] The drying method is not particularly limited as long as it can remove the aqueous medium contained in the aqueous ink or mixture coated on one side of the substrate 11, but examples include vacuum drying, pressure drying, heat drying, and air drying. The heating temperature is preferably 30 to 150°C, more preferably 40 to 120°C.

[0089] The method for producing the laminate 20 of FIG. 2 includes the above steps (1) and (2) in this order. In step (1), for example, an ink composition is applied to one surface of the substrate 21 and dried to form a first printed layer 22. In step (2), for example, the water-based ink of this embodiment is applied to the surface of the first printed layer 22 opposite the substrate 21 and dried to form a second printed layer 23. As in the method for producing the laminate 10, the kit of this embodiment may be used instead of the water-based ink. Step (1) may be performed once or twice or more times, that is, the ink composition may be applied in multiple coats. Step (2) may be carried out once or twice or more times, that is, the aqueous ink composition or mixture (M) may be applied multiple times. As the coating method and drying method in steps (1) and (2), the same methods as those used in the method for producing the laminate 10 can be applied.

[0090] <Application> The laminates 10 and 20 can be used as various labels such as plastic labels attached to packaging containers for beverages, foods such as prepared dishes and boxed lunches, daily necessities such as cosmetics, etc. Among these, they are particularly suitable as labels for food and beverages. In particular, when the substrates 11 and 21 constituting the laminates 10 and 20 are heat-shrinkable films, they are suitable as shrink labels.

[0091] <Other embodiments> The laminate is not limited to the above-described embodiment. For example, in the case of the laminate 10 shown in Fig. 1, the printed layer 12 is provided over the entire surface of one side of the substrate 11, but the printed layer 12 may also be provided over a portion of one side of the substrate 11. In this case, it is preferable that another printed layer is provided in the area of ​​one side of the substrate 11 where the printed layer 12 is not provided. Examples of the other printed layer include a layer formed from a varnish composition. 2, the second printed layer 23 is provided over the entire surface of one side of the first printed layer 22, but the second printed layer 23 may also be provided over a portion of one side of the first printed layer 22. In this case, it is preferable that another printed layer be provided in the area of ​​one side of the first printed layer 22 where the second printed layer 23 is not provided. Examples of the other printed layer include a layer formed from a varnish composition.

[0092] 1, another printed layer may be provided on the surface of the printed layer 12 opposite to the substrate 11. The other printed layer may be, for example, a layer formed from a varnish composition. Similarly, in the case of the laminate 20 shown in Fig. 2, another printed layer may be provided on the surface of the second printed layer 23 opposite to the first printed layer 22. The other printed layer may be, for example, a layer formed from a varnish composition.

[0093] <Labels, packaging> A label according to one embodiment of the present invention includes the laminate of the present embodiment described above. A label may be made of the laminate of the present embodiment described above. A package according to one embodiment of the present invention includes the laminate of the present embodiment described above. The package may be made of the laminate of the present embodiment described above. [Example]

[0094] The present invention will be explained in more detail below by way of examples, but the present invention is not limited to the following examples as long as it does not depart from the gist of the invention.

[0095] [Raw materials used] The following compound was used as the acrylic emulsion resin (A). A-1: Acrylic emulsion resin (Seiko PMC Corporation, product name "Hi-Loss-X-KE-1148", glass transition temperature 21°C, acid value 31 mg KOH / g, solid content 43% by mass). A-2: Styrene-acrylic copolymer emulsion resin (manufactured by Seiko PMC Corporation, product name "Hi-Loss-XJ-140A", glass transition temperature 6°C, acid value 33 mg KOH / g, solid content 41% by mass). A-3: Acrylic emulsion resin (manufactured by Covestro Coating Resins, product name "Neocryl XK-110", glass transition temperature 48°C, acid value 15 mg KOH / g, solid content 46% by mass). a-1: Styrene-acrylic copolymer emulsion resin (manufactured by BASF Japan Ltd., product name "Joncryl PDX-7158", glass transition temperature 55°C, acid value 54 mg KOH / g, solid content 41% by mass). a-2: Styrene-acrylic copolymer emulsion resin (manufactured by BASF Japan Ltd., product name "Joncryl PDX-7630A", glass transition temperature 53°C, acid value 200 mg KOH / g, solid content 32% by mass). In addition, a-1 and a-2 have an acid value of 40 mgKOH / g or more, and therefore correspond to the acrylic emulsion resin (B).

[0096] The following compound was used as the acrylic emulsion resin (B). b-1: Styrene-acrylic copolymer emulsion resin (manufactured by Covestro Coating Resins, product name "Neocryl A-662", glass transition temperature 95°C, acid value 24 mg KOH / g, solid content 40% by mass). b-2: Acrylic emulsion resin (manufactured by Covestro Coating Resins, product name "Neocryl XK-12", glass transition temperature 21°C, acid value 11 mg KOH / g, solid content 45% by mass). B-1: Acrylic emulsion resin (Seiko PMC Corporation, product name "Hi-Loss-X-ME-2039", glass transition temperature 8°C, acid value 42 mg KOH / g, solid content 48.5% by mass). B-2: Styrene-acrylic copolymer emulsion resin (Seiko PMC Corporation, product name "Hi-Loss-X-PE-2109", glass transition temperature -10°C, acid value 53 mg KOH / g, solid content 49.5% by mass). B-3: Acrylic emulsion resin (Seiko PMC Corporation, product name "Hi-Loss-X-PE-1126", glass transition temperature -12°C, acid value 50 mg KOH / g, solid content 41.5% by mass). B-4: Styrene-acrylic copolymer emulsion resin (manufactured by BASF Japan Ltd., product name "Joncryl PDX-7734", glass transition temperature 40°C, acid value 89 mg KOH / g, solid content 41.4% by mass). B-5: Styrene-acrylic copolymer emulsion resin (manufactured by BASF Japan Ltd., product name "Joncryl PDX-7630A", glass transition temperature 53°C, acid value 200 mg KOH / g, solid content 32% by mass). Since b-1 and b-2 have an acid value of less than 40 mgKOH / g, they fall under the acrylic emulsion resin (A). Also, a-2 and B-5 are the same resin.

[0097] As other resins, the compounds shown below were used. B'-1: Water-soluble acrylic resin (manufactured by BASF Japan Ltd., product name "Joncryl JDX-6180", weight average molecular weight 14,000, glass transition temperature 134°C, acid value 230 mgKOH / g, solid content 27% by mass).

[0098] The following compounds were used as titanium oxide and precipitated barium sulfate. Titanium oxide: Titanium oxide with a rutile crystal structure (manufactured by Ishihara Sangyo Kaisha, Ltd., product name "CR-90", oil absorption capacity 21 mL / 100 g, average particle size: 0.25 μm, solid content 100% by mass). Precipitated barium sulfate: precipitated barium sulfate particles (manufactured by Sakai Chemical Industry Co., Ltd., product name "Precipitated Barium Sulfate 200", average particle size: 0.8 μm, solid content 100% by mass).

[0099] Resin beads: Micropearl EX-002 (manufactured by Sekisui Chemical Co., Ltd., average particle size: 2 μm, solid content 100% by mass). Silicone resin: TEGO Glide 410 (manufactured by Evonik, solid content 100% by mass). Dispersant: SN Dispersant 2010 (manufactured by San Nopco, solid content 30% by mass). pH adjuster: Ammonia water. Antifoaming agent: BYK-1719 (BYK, solid content 100% by mass). · Thickener: SN Thickener 612 (manufactured by San Nopco, solid content 30% by mass). Surfactant: BYK-3480 (BYK, solid content 100% by mass). ·Aqueous medium: water. Aqueous medium: isopropanol.

[0100] [Evaluation method] (Evaluation of pigment dispersibility) The aqueous ink composition was stored at 40°C for 14 days, and then the increase in viscosity and the occurrence of aggregates were confirmed. In addition, an OPP film (trade name "FOR" manufactured by Futamura Chemical Co., Ltd., thickness 25 μm) was used as a substrate, and the aqueous ink composition was applied in a coating amount of 1.0 g / m after drying. 2 The substrate was coated by flexographic printing using a flexographic hand proofer as an applicator so that the pigment was in the range of 0.01 to 0.01. The coating was then dried with hot air from a dryer for 1 minute to form a printed layer (coating film). The condition of the coating film was visually confirmed. The pigment dispersibility was evaluated according to the following criteria. ◯ indicates practical use. ◯: The coating film has good hiding power and smoothness. The ink does not thicken over time and no agglomerates are formed. △: The hiding power or smoothness of the coating film is somewhat poor. The ink is confirmed to have increased in viscosity slightly over time, but no agglomerates are formed. ×: The coating film has very poor hiding power, smoothness, or both. The ink thickens over time and aggregates are formed.

[0101] (Evaluation of viscosity stability) The aqueous ink composition was confirmed to be in a uniform liquid state by visual inspection and by filtering through a 100-mesh wire screen. The viscosity was also measured using a Zahn Cup No. 5 manufactured by Rigo Co., Ltd. The fluidity was evaluated according to the following criteria. A rating of ○ indicates practical applicability. ◯: The aqueous ink composition was in a uniform liquid state, and no aggregates were formed even when filtered through a 100-mesh wire screen. The viscosity could be measured without any problems using a Zahn Cup No. 5 manufactured by Rigo Co., Ltd., and the measured viscosity value was 30 seconds or less. ×: The aqueous ink composition was gelled in whole or in part, or aggregates were observed when filtered through a 100-mesh wire screen, or even if it was in a homogeneous liquid state, it thickened and the viscosity measured using a Zahn Cup No. 5 manufactured by Rigo Co., Ltd. was more than 30 seconds, or the viscosity was impossible to measure.

[0102] (Evaluation of adhesion to substrate) As in the evaluation of pigment dispersibility, a printed layer (coating film) was formed on a substrate. After a certain period of time had passed, an 18 mm wide piece of cellophane tape (manufactured by Nichiban Co., Ltd.) was attached to the surface of the printed layer and pressed with a finger. The cellophane tape was then quickly peeled off, and the condition of the coating layer remaining on the substrate was visually inspected. The ratio of the area of ​​the peeled printed layer to the adhesive area of ​​the cellophane tape (peeling ratio) was calculated, and the adhesion of the coating layer was evaluated according to the following criteria: ◎, ○, and △: Practical. ⊚: The coating film did not peel off at all (peeling rate 0%). ○: Peeling rate is more than 0% and less than 20%. △: Peeling rate is 20% or more and less than 50%. ×: Peeling rate is 50% or more.

[0103] (Evaluation of abrasion resistance) As in the evaluation of pigment dispersibility, a printed layer (coating film) was formed on a substrate. The printed layer of the resulting laminate was rubbed with a rubbing cloth using a Gakushin-type rub fastness tester (manufactured by Tester Sangyo Co., Ltd., product name "AB-301"). The rubbing cloth used was a No. 3 gold cloth. The rub test conditions were a rub area of ​​24 cm 2 The load was 500 gf, and the number of reciprocating friction strokes was 100. After the friction stroke, the state of the fallen-off printed layer (wear state) was visually observed, and the ratio of the area of ​​the fallen-off printed layer to the friction area (fall-off rate) was calculated and evaluated according to the following criteria: ◎, ○, and △ indicate practical use. ⊚: The coating film did not come off at all (the rate of coming off was 0%). ◯: The rate of falling off is less than 20% and the substrate is not torn. △: The rate of falling off is 20% or more and less than 50%, and the substrate is not torn. ×: The rate of falling off is 50% or more, or the substrate is torn.

[0104] (Evaluation of water abrasion resistance) As in the evaluation of pigment dispersibility, a printed layer (coating film) was formed on a substrate. The printed layer of the resulting laminate was rubbed with a water-moistened rubbing cloth using a Gakushin-type rubbing fastness tester (manufactured by Tester Sangyo Co., Ltd., product name "AB-301"). The rubbing cloth used was a No. 3 gold cloth. The rubbing test conditions were a friction area of ​​24 cm 2 The load was 200 gf, and the number of reciprocating friction strokes was 100. After the friction stroke, the state of the fallen-off printed layer (wear state) was visually observed, and the ratio of the area of ​​the fallen-off printed layer to the friction area (fall-off rate) was calculated and evaluated according to the following criteria: ◎, ○, and △ indicate practical use. ⊚: The coating film did not come off at all (the rate of coming off was 0%). ◯: The rate of falling off is less than 20% and the substrate is not torn. △: The rate of falling off is 20% or more and less than 50%, and the substrate is not torn. ×: The rate of falling off is 50% or more, or the substrate is torn.

[0105] (Scratch resistance evaluation) As in the evaluation of pigment dispersibility, a printed layer (coating film) was formed on a substrate. The printed layer of the resulting laminate was rubbed back and forth with a fingernail about 20 times. After rubbing, the state of the removed printed layer was visually observed, and the ratio of the area of ​​the removed printed layer to the rubbed area (dropping rate) was calculated and evaluated according to the following criteria. ◎, ○, and △ indicate practical use. ⊚: The coating film did not come off at all (the rate of coming off was 0%). ◯: The rate of falling off is less than 20% and the substrate is not torn. △: The rate of falling off is 20% or more and less than 50%, and the substrate is not torn. ×: The rate of falling off is 50% or more, or the substrate is torn.

[0106] (Evaluation of heat resistance) As in the evaluation of pigment dispersibility, a printed layer (coating film) was formed on a substrate. Immediately after printing, the printed layer was dried with a dryer for 10 seconds, and then aluminum foil was placed on the surface of the printed layer (printed surface). A heat seal tester (manufactured by Tester Sangyo Co., Ltd., product name "TP-701-C Heat Seal Tester") was used to apply a pressure of 2 kg / cm. 2Heat sealing was performed for 1 second under a load of 0.015. The heat sealing temperature was in 20°C increments within the range of 80°C to 160°C. After that, the aluminum foil was peeled off, and the heat resistance of the printed layer was evaluated according to the following criteria. ◎, ○, and △ indicate practical use. ⊚: The printed layer was not transferred to the aluminum foil side at all. ◯: The area ratio of the printed layer transferred to the aluminum foil is 10% or more and less than 30%. △: The area ratio of the printed layer transferred to the aluminum foil is 30% or more and less than 50%. ×: The area ratio of the printed layer transferred to the aluminum foil is 50% or more.

[0107] [Examples 1 to 14, Comparative Examples 1 to 10] <Preparation of Water-Based Ink Composition> A mill-base composition was obtained by mixing acrylic emulsion resin (A), acrylic emulsion resin (B), or other resin with either or both of titanium oxide and precipitated barium sulfate, and optional ingredients according to the formulations shown in Tables 1 and 2. To the obtained mill-base composition, acrylic emulsion resin (A) or acrylic emulsion resin (B), and optional ingredients were added and mixed according to the formulations shown in Tables 1 and 2, to obtain an aqueous ink composition. The numerical values ​​relating to the blending amounts in Tables 1 and 2 refer to parts by mass. A blank space means that the component is not blended (amount blended: 0 parts by mass). The blending amounts include volatile components. "Aem" in Tables 1 and 2 refers to acrylic emulsion resin. The resulting aqueous ink compositions were evaluated for pigment dispersibility, viscosity stability, substrate adhesion, abrasion resistance, water abrasion resistance, scratch resistance, and heat resistance. The results are shown in Tables 1 and 2.

[0108] [Table 1]

[0109] [Table 2]

[0110] As shown in Table 1, the aqueous ink compositions obtained in each Example were excellent in pigment dispersibility and viscosity stability. Furthermore, the resulting printed layers were excellent in substrate adhesion, abrasion resistance, water abrasion resistance, scratch resistance, and heat resistance. Comparative Examples 1 to 5 and 8 are examples that did not contain either the acrylic emulsion resin (A) or the acrylic emulsion resin (B). The printed layer obtained from the aqueous ink composition of Comparative Example 1, which did not contain the acrylic emulsion resin (A), was poor in scratch resistance. The printed layers obtained from the aqueous ink compositions of Comparative Examples 2 and 3, which did not contain the acrylic emulsion resin (B), were poor in substrate adhesion. The printed layer obtained from the aqueous ink composition of Comparative Example 4, which did not contain the acrylic emulsion resin (A), was poor in scratch resistance. The printed layer obtained from the aqueous ink composition of Comparative Example 5, which did not contain the acrylic emulsion (A), was poor in substrate adhesion and water abrasion resistance. The aqueous ink composition of Comparative Example 6, in which the total content of acrylic emulsion resin (A) and acrylic emulsion resin (B) was less than 15% by mass, exhibited poor viscosity stability. The resulting printed layer also exhibited poor scratch resistance. The printed layer obtained from the aqueous ink composition of Comparative Example 7, in which the total content of acrylic emulsion resin (A) and acrylic emulsion resin (B) was more than 40% by mass, exhibited poor heat resistance. The aqueous ink composition of Comparative Example 8, which did not contain acrylic emulsion resin (A), exhibited poor viscosity stability. The resulting printed layer also exhibited poor scratch resistance. The printed layer obtained from the aqueous ink composition of Comparative Example 9, in which the mass ratio of acrylic emulsion resin (A):acrylic emulsion resin (B) was 1:0.80, exhibited poor abrasion resistance. The aqueous ink composition of Comparative Example 10, in which the mass ratio of acrylic emulsion resin (A):acrylic emulsion resin (B) was 1:50.65, exhibited poor viscosity stability.

[0111] (Application example) The laminate 20 described above also showed excellent evaluation results similar to those of Examples 1 to 14. [Explanation of symbols]

[0112] 10 Laminate 11 Base material 12 Printing layer (Printing layer (W)) 20 laminate 21 Base material 22 First printing layer (color printing layer (C)) 23 Second printing layer (printing layer (W))

Claims

1. An acrylic emulsion resin (A), an acrylic emulsion resin (B); An aqueous ink composition containing either or both of titanium oxide and precipitated barium sulfate, The acrylic emulsion resin (A) has an acid value of less than 40 mgKOH / g, the acid value of the acrylic emulsion resin (B) is 40 mgKOH / g or more and 250 mgKOH / g or less; the total content of the solid contents of the acrylic emulsion resin (A) and the acrylic emulsion resin (B) is 15 to 40 mass% relative to the total mass of the solid contents of the aqueous ink composition; a mass ratio of the solid content of the acrylic emulsion resin (A) to the solid content of the acrylic emulsion resin (B) (acrylic emulsion resin (A):acrylic emulsion resin (B)) is 1:1.0 to 1:

40.

2. 2. The water-based ink composition according to claim 1, wherein the acrylic emulsion resin (A) has a glass transition temperature of −20 to 60° C., and the acrylic emulsion resin (B) has a glass transition temperature of −20 to 60° C.

3. The aqueous ink composition according to claim 1, which is used together with a curing agent.

4. The water-based ink composition according to claim 1, further comprising resin beads.

5. 5. The water-based ink composition according to claim 4, wherein the resin beads have an average particle size of 0.5 to 8 μm.

6. The water-based ink composition according to claim 1, further comprising a silicone resin.

7. 7. The water-based ink composition according to claim 6, wherein the silicone-based resin is at least one selected from the group consisting of amine-modified silicone, silicone-modified acrylic, and polyether-modified silicone.

8. A water-based ink comprising the water-based ink composition according to any one of claims 1 to 7.

9. The water-based ink according to claim 8, which is for use on a plastic substrate or a paper substrate.

10. A laminate comprising a substrate and a printed layer formed on at least one surface of the substrate using the water-based ink according to claim 8, wherein the substrate is a plastic substrate or a paper substrate.

11. A label comprising the laminate of claim 10.

12. A package comprising the laminate of claim 10.

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