Ink composition for wallpaper, laminate, and wallpaper

Abstract

To provide a wallpaper ink composition capable of forming a printed layer with excellent abrasion resistance, heat resistance, embossability, and leveling properties; a laminate comprising a printed layer formed using the wallpaper ink composition; and wallpaper comprising the laminate. [Solution] A wallpaper ink composition comprising an aqueous (meth)acrylic resin (A), an ethylene-vinyl acetate copolymer resin emulsion (B), a free neutralizing agent (C), an extender pigment (D), and an aqueous medium, wherein the aqueous (meth)acrylic resin (A) comprises either or both of a (meth)acrylic resin emulsion (A1) and a (meth)acrylic resin dispersion (A2) having a glass transition temperature of 60 to 100°C, and the elongation of the ethylene-vinyl acetate copolymer resin emulsion (B) is 600% or more.

Description

Technical Field

[0001] The present invention relates to an ink composition for wallpaper, a laminate, and wallpaper.

Background Art

[0002] Wallpaper used as an interior material for houses and the like is manufactured by laminating a plastic film such as a vinyl chloride resin on a base material such as paper or non-woven fabric and applying printing to impart designability to its surface. In recent years, the designs of wallpaper have diversified, and in order to express high-definition patterns and deep textures, the importance of ink compositions using gravure printing and the like has increased.

[0003] Conventionally, as an ink for wallpaper, a composition in which a synthetic resin is used as a binder and pigments and various additives are blended therein is known. In the manufacturing process of wallpaper, since heat foaming treatment and embossing (molding) are performed after printing, the ink composition is required to have various properties that can withstand these severe processing conditions.

[0004] In addition, the leveling property of the printing layer is also one of the properties required for wallpaper ink. By improving the leveling property, the gradation of the gradation becomes smoother, and it becomes easier to realize the reproducibility of the intended pattern and a uniform and beautiful smooth surface. Furthermore, the durability (abrasion resistance) against physical contact during construction and during residence is also an extremely important factor in maintaining the product quality.

[0005] Patent Document 1 discloses an aqueous printing ink composition for wallpaper (wallpaper ink) characterized by containing (A) an inorganic acid and / or an organic acid, (B) 7 to 50% by weight of a vinyl monomer having an amino group having a specific structure in the molecule, and 1 to 30% by weight of a vinyl monomer having an acetylacetoxy group in the molecule, and after copolymerizing a monomer mixture consisting of 20 to 92% of other copolymerizable vinyl monomers, (A) an acrylic resin showing water solubility in the presence of (A), (C) an acrylic resin emulsion, and (D) a crosslinking agent.

[0006] Patent Document 2 discloses an aqueous ink for wallpaper (wallpaper ink) containing a vinyl chloride resin emulsion of a polymer consisting of (A) a polycarbonate-based urethane oligomer having a number average molecular weight of 5,000 to 50,000 and (B) a monomer composition containing vinyl chloride monomers.

[0007] Patent Document 3 discloses an aqueous coating agent for wallpaper (wallpaper ink) characterized by comprising a water-soluble or water-dispersible polyurethane resin (A) having an anionic group or anion-forming group in the molecule, and having a solubility parameter (SP value) of 11 to 12 and a glass transition temperature of 40 to 150°C. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Japanese Patent Application Publication No. 08-218026 [Patent Document 2] International Publication No. 2020 / 166660 [Patent Document 3] Japanese Patent Publication No. 2000-198962 [Overview of the Initiative] [Problems that the invention aims to solve]

[0009] However, with the conventional wallpaper inks described in Patent Documents 1 to 3, it is difficult to obtain a printed layer that has a good balance of abrasion resistance, heat resistance, embossing properties, and leveling properties.

[0010] The present invention aims to provide a wallpaper ink composition capable of forming a printed layer with excellent abrasion resistance, heat resistance, embossability, and leveling properties, a laminate comprising a printed layer formed using the wallpaper ink composition, and wallpaper comprising the laminate. [Means for solving the problem]

[0011] The present invention has the following aspects. [1] A wallpaper ink composition comprising an aqueous (meth)acrylic resin (A), an ethylene-vinyl acetate copolymer resin emulsion (B), a free neutralizing agent (C), an extender pigment (D), and an aqueous medium, The aqueous (meth)acrylic resin (A) comprises either or both of a (meth)acrylic resin emulsion (A1) and a (meth)acrylic resin dispersion (A2) having a glass transition temperature of 60 to 100°C. The elongation of the ethylene-vinyl acetate copolymer resin emulsion (B) is 600% or more. The solid content of the aqueous (meth)acrylic resin (A) is 65.0 to 82.0% by mass relative to the total mass of solids in the wallpaper ink composition. A wallpaper ink composition wherein the solid content of the ethylene-vinyl acetate copolymer resin emulsion (B) is 0.5 to 10.0% by mass relative to the total mass of solids in the wallpaper ink composition. [2] The wallpaper ink composition according to [1], wherein the total solid content of the (meth)acrylic resin emulsion (A1) and the (meth)acrylic resin dispersion (A2) is 20 to 80% by mass with respect to the total mass of the solid content of the aqueous (meth)acrylic resin (A). [3] The wallpaper ink composition according to [1] or [2], wherein the aqueous (meth)acrylic resin (A) comprises a vinyl chloride-(meth)acrylic copolymer resin (A3), and the glass transition temperature of the vinyl chloride-(meth)acrylic copolymer resin (A3) is less than 60°C. [4] The wallpaper ink composition according to any one of [1] to [3], wherein the ethylene-vinyl acetate copolymer resin emulsion (B) comprises an ethylene-vinyl acetate-(meth)acrylic copolymer resin emulsion. [5] A wallpaper ink composition according to any one of [1] to [4], further comprising a thickening agent, wherein the thickening agent comprises a urethane association type thickening agent. [6] A wallpaper ink composition according to any one of [1] to [5], further comprising wax. [7] The wallpaper ink composition according to any one of [1] to [6], further comprising an acetylenediol-based leveling agent. [8] The wallpaper ink composition according to any one of [1] to [7], wherein the free neutralizing agent (C) contains ammonia or an amine-based neutralizing agent, and the content of the free ammonia and the amine-based neutralizing agent is 0.2 to 2.5% by mass with respect to the total mass of the wallpaper ink composition. [9] A wallpaper ink composition according to any of [1] to [8], for gravure printing.

[10] A laminate comprising a wallpaper substrate and a printed layer formed on one surface of the wallpaper substrate using any of the wallpaper ink compositions described in [1] to [8].

[11] A laminate comprising a wallpaper substrate and a printed layer formed on one surface of the wallpaper substrate using the wallpaper ink composition described in [9].

[12] Wallpaper comprising the laminate described in

[10] . Wallpaper comprising the laminate described in

[13]

[11] . [Effects of the Invention]

[0012] According to the present invention, it is possible to provide a wallpaper ink composition capable of forming a printed layer with excellent abrasion resistance, heat resistance, embossability, and leveling properties, a laminate comprising a printed layer formed using the wallpaper ink composition, and wallpaper comprising the laminate. [Modes for carrying out the invention]

[0013] The present invention will now be described in detail. The following embodiments are merely illustrative for illustrating 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 its spirit. The definitions used herein are as follows: "Aqueous medium" refers to a liquid medium that contains water. "Liquid medium" refers to volatile liquids such as water and organic solvents. The term "aqueous (meth)acrylic resin" is a general term for "water-soluble (meth)acrylic resin" and "water-dispersible (meth)acrylic resin ((meth)acrylic resin emulsion, (meth)acrylic resin dispersion)". The contents of the aqueous (meth)acrylic resin and the ethylene-vinyl acetate copolymer resin emulsion are all in terms of solid content. The "solid content" of the ink composition for wallpaper refers to the components in the ink composition for wallpaper excluding the liquid medium, which are the components that finally form the ink layer, and specifically can be measured in accordance with JIS K 5601-1-2:2008. The same applies to the solid content of the aqueous (meth)acrylic resin and the ethylene-vinyl acetate copolymer resin emulsion. The "coating film" refers to the coating film formed by the ink composition for wallpaper of the present invention. That is, in this specification, the "printing layer" and the "coating film" are synonymous. The term "(meth)acrylate" is a general term for "acrylate" and "methacrylate". The term "(meth)acrylic acid" is a general term for "acrylic acid" and "methacrylic acid".

[0014] The glass transition temperature of the aqueous (meth)acrylic resin and the ethylene-vinyl acetate copolymer resin emulsion can be measured as follows in accordance with JIS K 7121:2012. Using a differential scanning calorimeter, the glass transition temperature is determined from the intersection of the baseline and the tangent of the endothermic curve in the curve (DSC curve) obtained by heating 10 mg of the solid content of the aqueous (meth)acrylic resin or the ethylene-vinyl acetate copolymer resin emulsion from -100°C to 160°C at a rate of 20°C / min.

[0015] The acid value of the aqueous (meth)acrylic resin and the ethylene-vinyl acetate copolymer resin emulsion is expressed as the number of milligrams of potassium hydroxide required to neutralize acid groups such as carboxyl groups per 1 g of the sample solid content, and can be measured in accordance with JIS K 5601-2-1:1999.

[0016] ≪Ink Composition for Wallpaper≫ The wallpaper ink composition of this embodiment (hereinafter also simply referred to as "ink composition") comprises an aqueous (meth)acrylic resin (A), an ethylene-vinyl acetate copolymer resin emulsion (B), a free neutralizing agent (C), an extender pigment (D), and an aqueous medium. The aqueous (meth)acrylic resin (A) comprises either or both of (meth)acrylic resin emulsion (A1) and (meth)acrylic resin dispersion (A2). The ink composition may further contain a thickening agent. The ink composition may further contain wax. The ink composition may further contain a leveling agent. The ink composition may further contain other components besides the aqueous (meth)acrylic resin (A), ethylene-vinyl acetate copolymer resin emulsion (B), free neutralizing agent (C), extender pigment (D), aqueous medium, thickener, wax, and leveling agent.

[0017] <Water-based (meth)acrylic resin (A)> Aqueous (meth)acrylic resin (A) is a binder component. Aqueous (meth)acrylic resin (A) has units based on (meth)acrylate. However, aqueous (meth)acrylic resin (A) does not have units based on ethylene or vinyl acetate.

[0018] Examples of aqueous (meth)acrylic resins include homopolymers of (meth)acrylate, copolymers of two or more (meth)acrylates, and copolymers of (meth)acrylate and monomers other than (meth)acrylate. The ratio of (meth)acrylate units to the total mass of all monomer units constituting the aqueous (meth)acrylic resin is preferably 10 to 100% by mass, and more preferably 20 to 100% by mass.

[0019] 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. (Meth)acrylate may be used alone or in combination of two or more types.

[0020] When the aqueous (meth)acrylic resin (A) is a (meth)acrylic resin dispersion (A2) or a water-soluble (meth)acrylic resin, it is preferable that it has units based on a hydrophilic group-containing monomer. Examples of hydrophilic group-containing monomers include the above-mentioned hydroxyl-containing (meth)acrylate and units based on acidic group-containing monomers described later. When the aqueous (meth)acrylic resin (A) is a (meth)acrylic resin emulsion (A1), it is preferable that the (meth)acrylic resin emulsion (A1) has units based on an acidic group-containing monomer, and more preferably has units based on a carboxyl group-containing monomer. Examples of monomers containing a carboxyl group include (meth)acrylic acid, maleic acid (maleic anhydride), fumaric acid, and itaconic acid (itaconic anhydride). The carboxyl group-containing monomer may be used alone or in combination of two or more types.

[0021] Examples of monomers other than (meth)acrylates and carboxyl group-containing monomers 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; and unsaturated carboxylic acid esters such as diethyl maleate, dibutyl maleate, dibutyl fumarate, diethyl itaconate, and dibutyl itaconate. These monomers may be used individually or in combination of two or more.

[0022] The aqueous (meth)acrylic resin (A) preferably contains either or both of (meth)acrylic resin emulsion (A1) and (meth)acrylic resin dispersion (A2), and more preferably contains (meth)acrylic resin emulsion (A1), from the viewpoint of lightfastness and heat resistance to yellowing of the resulting printed layer. Note that the resin having units based on (meth)acrylate and units based on vinyl chloride is a vinyl chloride-(meth)acrylic copolymer resin (A3) rather than (meth)acrylic resin emulsion (A1) and (meth)acrylic resin dispersion (A2).

[0023] (Meth)acrylic resin emulsion (A1) is an emulsion-type (meth)acrylic resin. (Meth)acrylic resin emulsion (A1) typically has a core-shell structure. The core portion of the core-shell structure is preferably a hydrophobic (meth)acrylic resin. The shell portion of the core-shell structure is preferably a hydrophilic (meth)acrylic resin. The core portion and the shell portion may be bonded together by a crosslinking agent.

[0024] The hydrophobic (meth)acrylic resin of the core is typically a resin containing units based on (meth)acrylate. Examples of such resins include homopolymers of (meth)acrylate, copolymers of two or more (meth)acrylates, and copolymers of (meth)acrylate and monomers other than (meth)acrylate. The (meth)acrylate is preferably one that does not have a carboxyl group. The (meth)acrylate and monomers other than (meth)acrylate are as described above.

[0025] The hydrophilic (meth)acrylic resin of the shell is typically a resin containing units based on carboxyl group-containing monomers. Examples of such resins include homopolymers of carboxyl group-containing monomers, copolymers of two or more carboxyl group-containing monomers, and copolymers of a carboxyl group-containing monomer and a monomer other than a carboxyl group-containing monomer. The monomer other than the carboxyl group-containing monomer can be any monomer that does not have a carboxyl group, and may be (meth)acrylate or a monomer other than (meth)acrylate. The carboxyl group-containing monomers are as described above.

[0026] The (meth)acrylic resin emulsion (A1) may be self-crosslinking. If the (meth)acrylic resin emulsion (A1) is self-crosslinking, the (meth)acrylic resin emulsion (A1) typically contains constituent units based on reactive functional group-containing monomers. These constituent units may be contained in the core, the shell, or both. Examples of monomers containing reactive functional groups include monomers containing alkoxysilyl groups, monomers containing hydrazine groups, monomers containing epoxy groups, monomers containing methylol groups, monomers containing alkoxymethyl groups, dihydrazide adipate, diacetone acrylamide, vinyl acetoacetate, allyl acetoacetate, and acetoacetoxyalkyl (meth)acrylate. Examples of epoxy group-containing monomers include glycidyl (meth)acrylate, 2,3-epoxycyclohexyl (meth)acrylate, 3,4-epoxycyclohexyl (meth)acrylate, and allyl glycidyl ether. Examples of acetoacetoxyalkyl (meth)acrylates include acetoacetoxyethyl (meth)acrylate, acetoacetoxypropyl (meth)acrylate, acetoacetoxybutyl (meth)acrylate, and 2,3-di(acetoacetoxy)propyl (meth)acrylate. Reactive functional group-containing monomers may be used individually or in combination of two or more.

[0027] The total content of units based on (meth)acrylate and units based on carboxyl group-containing monomers relative to the total mass of all monomer units constituting the (meth)acrylic resin emulsion (A1) is preferably 20 to 100% by mass, more preferably 50 to 100% by mass, and even more preferably 80 to 100% by mass.

[0028] In the (meth)acrylic resin emulsion (A1), the mass ratio of the core portion to the shell portion (core portion:shell portion) is preferably 20:80 to 90:10, more preferably 25:75 to 85:15, and even more preferably 30:70 to 80:20. If the amount of core portion is greater than the above range and the amount of shell portion is less, the storage stability of the ink composition, the film-forming properties, and the adhesion of the resulting printed layer to the wallpaper substrate will be slightly reduced. If the amount of core portion is less than the above range and the amount of shell portion is greater, the blocking resistance, abrasion resistance, and water abrasion resistance of the resulting printed layer will be slightly reduced.

[0029] The acid value of the (meth)acrylic resin emulsion (A1) is preferably 60 mgKOH / g or less, more preferably 55 mgKOH / g or less, and even more preferably 50 mgKOH / g or less. Furthermore, the acid value of the (meth)acrylic resin emulsion (A1) may be 0 mgKOH / g or more, 1 mgKOH / g or more, 5 mgKOH / g or more, 10 mgKOH / g or more, or 20 mgKOH / g or more. The above upper and lower limits can be combined as appropriate. If the acid value exceeds the above upper limit, the adhesion, alkali resistance, and water friction resistance of the resulting printed layer to the wallpaper substrate will be slightly reduced. When the aqueous (meth)acrylic resin (A) is a (meth)acrylic resin dispersion (A2) or a water-soluble (meth)acrylic resin, it is preferable that these resins do not have an acid value.

[0030] The average particle size of the (meth)acrylic resin emulsion (A1) is preferably 38 to 600 nm, more preferably 39 to 400 nm, and even more preferably 40 to 350 nm. If the average particle size of the (meth)acrylic resin emulsion (A1) is below the lower limit, the adhesion, alkali resistance, and water friction resistance of the resulting printed layer to the wallpaper substrate will be slightly reduced. If the average particle size of the (meth)acrylic resin emulsion (A1) is above the upper limit, the storage stability of the ink composition will be slightly reduced. The average particle size of (meth)acrylic resin emulsion (A1) is the particle size at which the volume-based cumulative frequency reaches 50% (median diameter: D50) calculated from the volume-based particle size distribution obtained by dynamic light scattering.

[0031] The glass transition temperatures of the (meth)acrylic resin emulsion (A1) and (meth)acrylic resin dispersion (A2) are 60 to 100°C, preferably 62 to 90°C, and more preferably 65 to 85°C. If the glass transition temperatures of the (meth)acrylic resin emulsion (A1) and (meth)acrylic resin dispersion (A2) are below the lower limit, the heat resistance of the resulting printed layer will decrease. If the glass transition temperatures of the (meth)acrylic resin emulsion (A1) and (meth)acrylic resin dispersion (A2) exceed the upper limit, the abrasion resistance of the resulting printed layer will decrease. Adhesion to the wallpaper substrate will also decrease.

[0032] The weight-average molecular weight of the (meth)acrylic resin emulsion (A1) and (meth)acrylic resin dispersion (A2) is preferably 30,000 to 1,000,000, more preferably 50,000 to 900,000, and even more preferably 70,000 to 800,000. If the weight-average molecular weight of the (meth)acrylic resin emulsion (A1) and (meth)acrylic resin dispersion (A2) is below the lower limit, the abrasion resistance, water abrasion resistance, and blocking resistance of the resulting printed layer will be slightly reduced. If the weight-average molecular weight of the (meth)acrylic resin emulsion (A1) and (meth)acrylic resin dispersion (A2) is above the upper limit, the storage stability of the ink composition will be slightly reduced. The weight-average molecular weight of aqueous (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). The same applies to other resins.

[0033] The aqueous (meth)acrylic resin (A) may be one manufactured by a known manufacturing method or a commercially available product. In the production of aqueous (meth)acrylic resin (A), the polymerization method of the monomer is not particularly limited, but examples include radical polymerization, anionic polymerization, cationic polymerization, etc. In particular, radical polymerization includes bulk polymerization, solution polymerization, emulsion polymerization, suspension polymerization, etc. Among these, emulsion polymerization is preferred. Emulsion polymerization is a method of polymerization in which the monomers used for polymerization are polymerized in an aqueous medium in the presence of an emulsifier and a polymerization initiator. (Meth)acrylic resin emulsion (A1) may be produced by compounding the core and shell parts after producing them separately, or it may be produced by multi-step emulsion polymerization. The polymerization mode may be any of random copolymer, block copolymer, graft copolymer, etc.

[0034] Water-based (meth)acrylic resin (A) may be used alone or in combination of two or more types. When using (meth)acrylic resin emulsion (A1) as the water-based (meth)acrylic resin (A), (meth)acrylic resin emulsion (A1) may be used alone or in combination of two or more types. When using (meth)acrylic resin dispersion (A2) as the water-based (meth)acrylic resin (A), one type of (meth)acrylic resin dispersion (A2) may be used alone, or two or more types may be used in combination.

[0035] [Vinyl chloride-(meth)acrylic copolymer resin (A3)] The vinyl chloride-(meth)acrylic copolymer resin (A3) is a resin having units based on (meth)acrylate and units based on vinyl chloride. The vinyl chloride-(meth)acrylic copolymer resin (A3) may have units based on an acidic group-containing monomer and units based on monomers other than acidic group-containing monomers, but it is preferable that it has units based on an acidic group-containing monomer. As the acidic group-containing monomer, a carboxyl group-containing monomer is preferred. When the ink composition contains the vinyl chloride-(meth)acrylic copolymer resin (A3), the abrasion resistance, leveling properties, and adhesion to the wallpaper substrate of the resulting printed layer tend to improve.

[0036] Examples of (meth)acrylates include the (meth)acrylate described in the section on water-based (meth)acrylic resin (A). (Meth)acrylate may be used alone or in combination of two or more types.

[0037] Examples of carboxyl group-containing monomers include the carboxyl group-containing monomer described in the section on aqueous (meth)acrylic resin (A). The carboxyl group-containing monomer may be used alone or in combination of two or more types.

[0038] Monomers other than (meth)acrylate and carboxyl group-containing monomers include the monomers other than (meth)acrylate and carboxyl group-containing monomers described in aqueous (meth)acrylic resin (A). These monomers may be used individually or in combination of two or more.

[0039] The vinyl chloride-(meth)acrylic copolymer resin (A3) is preferably an emulsion-type vinyl chloride-(meth)acrylic copolymer resin. The vinyl chloride-(meth)acrylic copolymer resin (A3) typically has a core-shell structure. The core portion of the core-shell structure is preferably a hydrophobic (meth)acrylic resin. The shell portion of the core-shell structure is preferably a hydrophilic (meth)acrylic resin. The core portion and the shell portion may be bonded together by a crosslinking agent. For example, in the core portion or shell portion of the (meth)acrylic resin emulsion (A1) having the above-described core-shell structure, the vinyl chloride-(meth)acrylic copolymer resin (A3) is preferably a vinyl chloride-(meth)acrylic copolymer resin (A3) having units based on vinyl chloride.

[0040] The total content of units based on (meth)acrylate, units based on vinyl chloride, and units based on carboxyl group-containing monomers relative to the total mass of all monomer units constituting the vinyl chloride-(meth)acrylic copolymer resin (A3) is preferably 20 to 100% by mass, more preferably 50 to 100% by mass, and even more preferably 80 to 100% by mass.

[0041] The acid value of the vinyl chloride-(meth)acrylic copolymer resin (A3) is preferably 30 mg KOH / g or less, more preferably 20 mg KOH / g or less, and even more preferably 10 mg KOH / g or less. If the acid value exceeds the above upper limit, the alkali resistance and water friction resistance of the resulting printed layer to the wallpaper substrate will be slightly reduced.

[0042] The average particle size of the vinyl chloride-(meth)acrylic copolymer resin (A3) is preferably 50 to 600 nm, more preferably 100 to 400 nm, and even more preferably 100 to 350 nm. If the average particle size of the vinyl chloride-(meth)acrylic copolymer resin (A3) is below the lower limit, the dispersion stability of the ink composition is slightly reduced. If the average particle size of the vinyl chloride-(meth)acrylic copolymer resin (A3) is above the upper limit, the storage stability of the ink composition is slightly reduced. The average particle size of the vinyl chloride-(meth)acrylic copolymer resin (A3) can be measured in the same manner as the average particle size of the (meth)acrylic resin emulsion (A1) described above.

[0043] The glass transition temperature of the vinyl chloride-(meth)acrylic copolymer resin (A3) is preferably less than 60°C, more preferably 10 to 55°C, and even more preferably 20 to 50°C. If the glass transition temperature of the vinyl chloride-(meth)acrylic copolymer resin (A3) is below the lower limit, the heat resistance of the resulting printed layer will be slightly reduced. If the glass transition temperature of the vinyl chloride-(meth)acrylic copolymer resin (A3) is above the upper limit, the abrasion resistance of the resulting printed layer will be slightly reduced. In addition, the adhesion to the wallpaper substrate will also be slightly reduced.

[0044] The weight-average molecular weight of the vinyl chloride-(meth)acrylic copolymer resin (A3) is preferably 30,000 to 1,000,000, more preferably 50,000 to 900,000, even more preferably 70,000 to 800,000, and particularly preferably 100,000 to 800,000. If the weight-average molecular weight of the vinyl chloride-(meth)acrylic copolymer resin (A3) is below the lower limit, the abrasion resistance, water abrasion resistance, and blocking resistance of the resulting printed layer will be slightly reduced. If the weight-average molecular weight of the vinyl chloride-(meth)acrylic copolymer resin (A3) is above the upper limit, the storage stability of the ink composition will be slightly reduced.

[0045] As the vinyl chloride-(meth)acrylic copolymer resin (A3), you may use one produced by a known manufacturing method or a commercially available product. The vinyl chloride-(meth)acrylic copolymer resin (A2) may be used alone or in combination of two or more types.

[0046] <Ethylene-vinyl acetate copolymer resin emulsion (B)> Ethylene-vinyl acetate copolymer resin emulsion (B) is a copolymer reaction product of ethylene and vinyl acetate. Furthermore, ethylene-vinyl acetate copolymer resin emulsion (B) may optionally contain units based on monomers other than ethylene and vinyl acetate (other monomers), and is not particularly limited as long as it is copolymerizable with ethylene and vinyl acetate. Examples of other monomers include vinyl alcohol, vinyl chloride, vinylidene chloride, (meth)acrylate, and acidic group-containing monomers. Examples of acidic group-containing monomers include carboxyl group-containing monomers, such as the carboxyl group-containing monomer described in aqueous (meth)acrylic resin (A). Among these, ethylene-vinyl acetate-(meth)acrylic copolymer resin emulsion obtained by copolymerizing either (meth)acrylate or (meth)acrylic acid, or both, is preferred as the other monomer. When an ink composition contains ethylene-vinyl acetate-(meth)acrylic copolymer resin emulsion, the abrasion resistance and leveling properties of the resulting printed layer tend to improve.

[0047] The total content of ethylene-based units and vinyl acetate-based units relative to the total mass of all monomer units constituting the ethylene-vinyl acetate copolymer resin emulsion (B) is preferably 20 to 100% by mass, more preferably 50 to 100% by mass, and even more preferably 70 to 100% by mass.

[0048] The total content of ethylene-based units, vinyl acetate-based units, (meth)acrylate-based units, and (meth)acrylic acid-based units relative to the total mass of all monomer units constituting the ethylene-vinyl acetate-(meth)acrylic copolymer resin emulsion is preferably 20 to 100% by mass, more preferably 50 to 100% by mass, and even more preferably 70 to 100% by mass.

[0049] The elongation (breaking elongation) of the ethylene-vinyl acetate copolymer resin emulsion (B), as measured by the following measurement method, is 600% or more, preferably 700% or more, more preferably 900% or more, and even more preferably 1200% or more. The upper limit of the elongation is not particularly limited, but for example, it is 2500% or less. The breaking elongation of the ethylene-vinyl acetate copolymer resin emulsion (B) tends to improve when the vinyl acetate unit content is increased and / or the weight-average molecular weight is increased, and this can be adjusted by those skilled in the art. If the elongation at break is below the above lower limit, the abrasion resistance and leveling properties of the resulting printed layer will decrease. [Measurement method] An ethylene-vinyl acetate copolymer resin emulsion (B) was dried at 23°C and 65% RH humidity for 7 days to form a film, and a 15 mm thick film (in the shape of a dumbbell) was prepared. A tensile test was performed at a tensile strength of 500 mm / min at 25°C, and the elongation at break was calculated from the length of the film before the tensile test and the length of the film at break using formula 1 below. (La-Lb) / Lb × 100 Equation 1 In formula 1 above, Lb is the length of the film before the tensile test, and La is the length of the film at the time of breakage.

[0050] The glass transition temperature of the ethylene-vinyl acetate copolymer resin emulsion (B) is preferably -40 to 5°C, more preferably -38 to -10°C, and even more preferably -35 to -15°C. If the glass transition temperature of the ethylene-vinyl acetate copolymer emulsion (B) is below the lower limit, the blocking resistance, abrasion resistance, and heat resistance of the resulting printed layer will be slightly reduced. If the glass transition temperature of the ethylene-vinyl acetate copolymer emulsion (B) is above the upper limit, the adhesion of the resulting printed layer to the wallpaper substrate will be slightly reduced.

[0051] Examples of commercially available ethylene-vinyl acetate copolymer resin emulsions (B) include the product names "Sumikaflex 900HL," "Sumikaflex S-401HQ," and "Sumikaflex S-408HQE" manufactured by Sumitomo Chemical Co., Ltd. The ethylene-vinyl acetate copolymer resin emulsion (B) may be used alone or in combination of two or more types.

[0052] <Free neutralizing agent (C)> The neutralizing agent is used to neutralize acidic groups (e.g., sulfonic acid groups, carboxyl groups) in the aqueous (meth)acrylic resin (A) and ethylene-vinyl acetate copolymer resin emulsion (B) in order to make them aqueous. Any excess neutralizing agent is present in the ink composition as free neutralizing agent (C). Specifically, examples include ammonia; organic amines such as monoethylamine, diethylamine, trimethylamine, triethylamine, triisopropylamine, 2-amino-2-methyl-1-propanoltributylamine, triethanolamine, methyldiethanolamine, monoethanolamine, dimethylethanolamine, diethylethanolamine, morpholine, N-methylmorpholine, and 2-amino-2-ethyl-1-propanol (amine-based neutralizing agents); and inorganic alkalis such as sodium hydroxide and potassium hydroxide. In particular, from the viewpoint of drying properties, ammonia and amine-based neutralizing agents are preferred, with ammonia, trimethylamine, triethylamine, and 2-amino-2-methyl-1-propanol being preferred. The neutralizing agent may be used alone or in combination of two or more types.

[0053] <Extender pigment (D)> Extender pigments (D) are solid particles formed from inorganic materials. Examples of extender pigments (D) include barium sulfate, calcium sulfate, calcium carbonate, calcium silicate, magnesium silicate, silica, alumina, zirconia, tin oxide, clay, and kaolin. Among these, silica is preferred from the viewpoint of superior matte finish, design appeal, and cost-effectiveness. Extender pigments (D) may be used individually or in combination of two or more types.

[0054] The average particle size of the extender pigment (D) is preferably 12 μm or less, more preferably 11 μm or less, and even more preferably 10 μm or less. The lower limit of the average particle size is not particularly limited, but for example, it is 1 μm or more. If the average particle size of the extender pigment (D) is less than the above lower limit, the blocking resistance and matte properties of the resulting printed layer may be slightly reduced. If the average particle size of the extender pigment (D) exceeds the above upper limit, the storage stability of the ink composition may be slightly reduced. The average particle size of the extender pigment (D) is the particle size at 50% of the volume-based cumulative value (D50) in the particle size distribution measured by laser diffraction-scattering if the average particle size is 100 nm or more, and the particle size at 50% of the number-based cumulative value (D50) in the particle size distribution measured using a transmission electron microscope (TEM) if the average particle size is less than 100 nm. If the extender pigment (D) is a commercially available product, the above value can be used if the manufacturer discloses the D50 value measured by laser diffraction-scattering.

[0055] Commercial silica products may be used. Examples of commercially available products include the "SYLYSIA" series, "SYLOPHOBIC" series, and "SYLOSPHERE" series from Fuji Silysia Chemical Co., Ltd., and the "NipSeal SS" series, "NipSeal WE" series, "NipSeal E" series, "NipSeal K" series, and "NipSeal AZ" series from Tosoh Silica Co., Ltd.

[0056] <Aqueous medium> Examples of aqueous media include water; and mixed solvents of water and organic solvents. The organic solvent is not particularly limited as long as it is soluble in water, but examples include alcoholic solvents such as methanol, ethanol, n-propanol, i-propanol, n-butanol, and i-butanol; and ketoneic solvents such as acetone. However, even if glycols and glycol derivatives are liquid and soluble in water at 25°C, they are not included in aqueous media in this specification. Glycol derivatives mean glycol ethers and glycol esters. Glycols and glycol derivatives are other components described later in this specification. These organic solvents may be used individually or in combination of two or more.

[0057] <wax> To further improve the water resistance, abrasion resistance, and blocking resistance of the printed layer, the ink composition may contain additional wax. Examples of waxes include hydrocarbon waxes, fluorine-modified waxes, and silicone-modified waxes. Wax may be used individually or in combination of two or more types.

[0058] As for the hydrocarbon wax, a water-based wax is preferred. Aqueous wax is a wax that has been dispersed in water to form an emulsion or dispersion. The hydrocarbon wax dispersed in water 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.

[0059] 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. Hydrocarbon waxes may be used individually or in combination of two or more types.

[0060] Examples of silicone-modified waxes include polydimethylsiloxane, polyalkyl silicone, and urethane silicone copolymer. Silicone-modified waxes may be used individually or in combination of two or more types.

[0061] The average particle size of the wax is preferably 12 μm or less, more preferably 10 μm or less, and even more preferably 8 μm or less. The average particle size of the wax may also be 0.1 μm or more, 0.5 μm or more, 1 μm or more, or 1.5 μm or more. If the average particle size of the wax is below the lower limit, the adhesion, abrasion resistance, and water abrasion resistance of the resulting printed layer to the wallpaper substrate will be slightly reduced. If the average particle size of the wax exceeds the upper limit, the printability will be slightly reduced. If the wax is an aqueous wax, the average particle size of the dispersed particles in the aqueous wax can be considered as the average particle size of the wax in the ink composition. The average particle size of the wax is the particle size at which the cumulative frequency of particles reaches 50% (median diameter: D50) is calculated from the particle size distribution obtained by measuring the particle size distribution based on the number of particles using the Coulter counter method. The Coulter counter method is a method of electrically measuring the particle size and particle size distribution of particles by passing particles dispersed in a medium through pores and observing the change in electrical signals as the particles pass through.

[0062] <Thickening agent> A thickening agent may be further added to the ink composition for the purpose of increasing its viscosity and improving its stability. Examples of thickeners include polyurethane-based thickeners, acrylic-based thickeners, polyamide-based thickeners, cellulose-based thickeners, and clay minerals such as bentonite. Among these, polyurethane-based thickeners are preferred because they are excellent at improving the storage stability of the ink composition, and among these, associated polyurethane-based thickeners (hereinafter also referred to as "urethane associated thickeners") are particularly preferred.

[0063] Associative thickeners are polymers that have both hydrophobic and hydrophilic groups in their molecules. The hydrophobic groups of the thickener interact with each other or with hydrophobic substances such as resins through intermolecular interactions, forming a network structure and increasing the viscosity of the ink composition. Furthermore, the viscosity of the ink composition is also increased by the association of the hydrophilic groups of the thickener with the hydrophilic groups on the emulsion surface of aqueous (meth)acrylic resin (A) or ethylene-vinyl acetate copolymer resin emulsion (B). Examples of hydrophobic groups in association-type thickeners include alkyl groups and phenyl groups. Examples of hydrophilic groups in associated thickeners include hydroxyl groups, amide groups, and carboxyl groups.

[0064] Examples of urethane-associated thickeners include urethane-modified polyethers and polyether polyol-based urethane prepolymers.

[0065] Examples of commercially available urethane-associated thickeners include the "SN Thickener" series manufactured by Sunopco Corporation. The thickening agent may be used alone or in combination of two or more types.

[0066] <Leveling agent> To improve the leveling properties of the resulting printed layer, a leveling agent may be further included in the ink composition. Examples of leveling agents include acetylenediol-based leveling agents, silicone-based leveling agents such as polyether-modified polydimethylsiloxane and polyester-modified polydimethylsiloxane, and (meth)acrylic-based leveling agents such as polyacrylates, with acetylenediol-based leveling agents being preferred. An example of an acetylenediol-based leveling agent is "Acetylenel E13T" manufactured by Kawaken Fine Chemicals Co., Ltd. Leveling agents may be used individually or in combination of two or more types.

[0067] <Other ingredients> Other components include, for example, binder resins other than aqueous (meth)acrylic resin (A) and ethylene-vinyl acetate copolymer resin emulsion (B), pigments other than extender pigments (coloring pigments), anti-settlement agents, UV absorbers, antioxidants, dispersants, film-forming aids, defoaming agents, lubricants, stabilizers, surface modifiers, surfactants, silicone additives, foam inhibitors, corrosion inhibitors, film-forming aids, drying agents, release agents, and wetting agents. These other components may be used individually or in combination of two or more. Examples of film-forming aids include glycol derivatives that are liquid at 25°C as described above. Examples of drying agents include glycols that are liquid at 25°C as described above. Examples of release agents include glycols that are solid at 25°C. Examples of such glycols include polyethylene glycol (PEG) with a number average molecular weight of 1500 or more. The ink composition of this embodiment may contain both an extender pigment and a coloring pigment, or it may contain an extender pigment but not a coloring pigment. An ink composition containing an extender pigment but not a coloring pigment is known as an extender and is used to adjust the concentration of an ink (containing a coloring pigment).

[0068] Other binder resins include, for example, aqueous resins other than aqueous (meth)acrylic resin (A) and ethylene-vinyl acetate copolymer emulsion (B). Examples of such aqueous resins include aqueous urethane resin, aqueous polyolefin resin, and aqueous vinyl chloride-vinyl acetate copolymer resin.

[0069] <Composition of the ink composition> The total solid content of the aqueous (meth)acrylic resin (A) and the ethylene-vinyl acetate copolymer resin emulsion (B) is preferably 68 to 83% by mass, more preferably 70 to 80% by mass, and even more preferably 72 to 77% by mass, relative to the total mass of solids in the ink composition.

[0070] The total solid content of the aqueous (meth)acrylic resin (A) and the ethylene-vinyl acetate copolymer resin emulsion (B) is preferably 15 to 33% by mass, more preferably 16 to 28% by mass, and even more preferably 18 to 23% by mass, based on the total mass of the ink composition.

[0071] The solid content of the aqueous (meth)acrylic resin (A) is 65.0 to 82.0% by mass, preferably 68.0 to 80.0% by mass, more preferably 70.0 to 78.0% by mass, and even more preferably 71.0 to 75.0% by mass, relative to the total mass of solids in the ink composition. If the content of aqueous (meth)acrylic resin (A) is below the lower limit, the embossability and leveling properties of the resulting printed layer will decrease. If the content of aqueous (meth)acrylic resin (A) exceeds the upper limit, the abrasion resistance of the resulting printed layer will decrease. Adhesion to the wallpaper substrate will also decrease.

[0072] The solid content of the aqueous (meth)acrylic resin (A) is preferably 14 to 33% by mass, more preferably 16 to 28% by mass, and even more preferably 18 to 23% by mass, based on the total mass of the ink composition. If the content of aqueous (meth)acrylic resin (A) is below the lower limit, the embossability and leveling properties of the resulting printed layer will decrease. If the content of aqueous (meth)acrylic resin (A) exceeds the upper limit, the abrasion resistance of the resulting printed layer will decrease. Adhesion to the wallpaper substrate will also decrease.

[0073] The total solid content of the (meth)acrylic resin emulsion (A1) and (meth)acrylic resin dispersion (A2) is preferably 10 to 74% by mass, more preferably 20 to 55% by mass, and even more preferably 32 to 40% by mass, relative to the total mass of solid content of the ink composition.

[0074] The total solid content of the (meth)acrylic resin emulsion (A1) and (meth)acrylic resin dispersion (A2) is preferably 2 to 22% by mass, more preferably 5 to 15% by mass, and even more preferably 8 to 12% by mass, based on the total mass of the ink composition.

[0075] When the ink composition contains vinyl chloride-(meth)acrylic copolymer resin (A3), the solid content of vinyl chloride-(meth)acrylic copolymer resin (A3) is preferably 10 to 63% by mass, more preferably 25 to 50% by mass, and even more preferably 30 to 40% by mass, based on the total mass of solids in the ink composition.

[0076] When the ink composition contains vinyl chloride-(meth)acrylic copolymer resin (A3), the solid content of vinyl chloride-(meth)acrylic copolymer resin (A3) is preferably 2 to 18% by mass, more preferably 5 to 16% by mass, and even more preferably 8 to 14% by mass, based on the total mass of the ink composition.

[0077] The total solid content of the (meth)acrylic resin emulsion (A1) and (meth)acrylic resin dispersion (A2) is preferably 20 to 100% by mass, more preferably 20 to 80% by mass, even more preferably 30 to 80% by mass, and particularly preferably 40 to 60% by mass, relative to the total mass of solid content of the aqueous (meth)acrylic resin (A). If the solid content of the (meth)acrylic resin emulsion (A1) and (meth)acrylic resin dispersion (A2) is below the lower limit, the heat resistance of the resulting printed layer will be slightly reduced. If the solid content of the (meth)acrylic resin emulsion (A1) and (meth)acrylic resin dispersion (A2) exceeds the upper limit, the abrasion resistance of the resulting printed layer will be slightly reduced.

[0078] The total solid content of the (meth)acrylic resin emulsion (A1), (meth)acrylic resin dispersion (A2), and vinyl chloride-(meth)acrylic copolymer resin (A3) is preferably 50 to 100% by mass, more preferably 80 to 100% by mass, and even more preferably 90 to 100% by mass, relative to the total mass of solid content of the aqueous (meth)acrylic resin (A). It may also be 100% by mass.

[0079] The solid content of the ethylene-vinyl acetate copolymer resin emulsion (B) is 0.5 to 10.0% by mass, preferably 0.8 to 8.0% by mass, more preferably 1.2 to 5.0% by mass, and even more preferably 1.5 to 2.1% by mass, relative to the total mass of solids in the ink composition. If the content of the ethylene-vinyl acetate copolymer resin emulsion (B) is below the lower limit, the abrasion resistance of the resulting printed layer will decrease. If the content of the ethylene-vinyl acetate copolymer resin emulsion (B) exceeds the upper limit, the leveling properties of the resulting printed layer will decrease.

[0080] The solid content of the ethylene-vinyl acetate copolymer resin emulsion (B) is preferably 0.15 to 2.6% by mass, more preferably 0.25 to 1.5% by mass, and even more preferably 0.3 to 0.8% by mass, relative to the total mass of the ink composition. If the content of the ethylene-vinyl acetate copolymer resin emulsion (B) is below the lower limit, the abrasion resistance of the resulting printed layer will decrease. If the content of the ethylene-vinyl acetate copolymer resin emulsion (B) exceeds the upper limit, the leveling properties of the resulting printed layer will decrease.

[0081] The total solid content of the aqueous (meth)acrylic resin (A) and the ethylene-vinyl acetate copolymer resin emulsion (B) is preferably 70 to 100% by mass, more preferably 80 to 100% by mass, and even more preferably 90 to 100% by mass, relative to the total mass of solid content of the binder resin. It may also be 100% by mass.

[0082] The content of the free neutralizing agent (C) is preferably 0.05 to 3% by mass, more preferably 0.2 to 2.5% by mass, and even more preferably 0.4 to 2% by mass, relative to the total mass of the ink composition. Ammonia or an amine-based neutralizing agent is preferred. If the content of the free neutralizing agent (C) is below the lower limit, the resolubility of the ink composition will be slightly reduced. Low resolubility of the ink composition can cause transfer defects if the ink composition remaining in the cells of the gravure plate or on the flexographic plate dries. Resolubility refers to the ability to redissolve the ink composition in the aqueous medium before it dries and causes transfer defects. If the content of the free neutralizing agent (C) exceeds the upper limit, the abrasion resistance of the resulting printed layer will be slightly reduced.

[0083] The content of the extender pigment (D) is preferably 0.5 to 10% by mass, more preferably 1 to 8% by mass, and even more preferably 2 to 6% by mass, relative to the total mass of the ink composition. If the content of the extender pigment (D) is below the lower limit, the opacity and color development of the resulting printed layer tend to decrease. If the pigment content exceeds the upper limit, the adhesion of the resulting printed layer to the substrate tends to decrease. In addition, the ink fluidity of the ink composition may decrease.

[0084] The content of the aqueous medium is preferably 30 to 85% by mass, more preferably 40 to 82% by mass, and even more preferably 50 to 80% by mass, relative to the total mass of the ink composition. If the content of the aqueous medium is below the lower limit, the ink fluidity tends to decrease. If the content of the aqueous medium exceeds the upper limit, the drying properties tend to decrease.

[0085] When the ink composition contains a thickener, the solid content of the thickener is preferably 0.05 to 5% by mass, more preferably 0.1 to 3% by mass, and even more preferably 0.5 to 2% by mass, relative to the total mass of the ink composition. A urethane-associated thickener is preferred, and a neutonian-based urethane-associated thickener is more preferred.

[0086] When the ink composition contains wax, the amount of solid wax is preferably 0.5 to 5% by mass, more preferably 1 to 3% by mass, and even more preferably 1.5 to 2% by mass, relative to the total mass of solids in the ink composition. If the wax content is below the lower limit, the abrasion resistance of the resulting printed layer will be slightly reduced. If the wax content exceeds the upper limit, the color development of the resulting printed layer will be slightly reduced.

[0087] When the ink composition contains a leveling agent, the solid content of the leveling agent is preferably 1 to 8% by mass, more preferably 1.5 to 6% by mass, and even more preferably 2 to 5% by mass, relative to the total mass of solids in the ink composition. If the leveling agent content is below the lower limit, the leveling properties of the resulting printed layer will be slightly reduced. If the leveling agent content exceeds the upper limit, the water abrasion resistance of the resulting printed layer will be slightly reduced. The drying properties of the ink composition will also be slightly reduced. Acetylenediol-based leveling agents are preferred as the leveling agent.

[0088] The solid content is preferably 15 to 45% by mass, more preferably 20 to 40% by mass, and even more preferably 23 to 35% by mass, based on the total mass of the ink composition.

[0089] The content of other components is not particularly limited as long as it does not impair the effects of the present invention, but for example, it is preferably 0 to 20% by mass, more preferably 0 to 15% by mass, even more preferably 0 to 10% by mass, particularly preferably 0 to 5% by mass, and particularly preferably 0 to 1% by mass, based on the total mass of the ink composition. If the ink composition contains other components, the content of these other components is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and even more preferably 0.5% by mass or more, relative to the total mass of the ink composition. If the content of these other components is above the above lower limit, the effects of these other components will be fully realized.

[0090] <Method for manufacturing wallpaper ink composition> The ink composition of this embodiment can be obtained, for example, by dissolving or dispersing in an aqueous medium one or more of an aqueous (meth)acrylic resin (A), an ethylene-vinyl acetate copolymer resin emulsion (B), a neutralizing agent (free neutralizing agent (C)), an extender pigment (D), and optionally one or more of a thickener, wax, leveling agent, and other components. The method of mixing each component is not particularly limited, and the components can be mixed by various methods. The method for dissolving or dispersing each component in an aqueous medium is not particularly limited and can be carried out using known dispersers. Examples of dispersers include paint shakers, ball mills, attritors, sand mills, bead mills, dyno mills, roll mills, dissolvers, 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.

[0091] <Applications, laminates, wallpaper> The ink composition of this embodiment is typically printed on a wallpaper substrate to form an ink layer. Examples of substrates for wallpaper include those in which a plastic film mainly composed of synthetic resin such as polyvinyl chloride (PVC) resin is laminated on a support such as paper or nonwoven fabric.

[0092] Examples of resins that make up plastic films include olefin resins such as polyvinyl chloride, polyethylene, and polypropylene; polyester resins such as ethylene-vinyl alcohol copolymer and polyethylene terephthalate (PET); (meth)acrylic resins; urethane resins; and styrene resins. These plastic films may be used individually or in combination of two or more types.

[0093] In addition to the resin mentioned above, the plastic film may contain foaming agents, plasticizers, fillers, flame retardants, stabilizers, pigments, and other additives as appropriate.

[0094] Examples of foaming agents include thermally decomposed chemical foaming agents such as azodicarbonamide (ADCA) and azobisisobutyronitrile, and foaming aids such as zinc oxide may be used in combination as needed. These foaming agents decompose thermally in the heating process described later (for example, at 180°C to 230°C) to generate gas, which expands the plastic film and imparts rich cushioning and design properties to the wallpaper.

[0095] As plasticizers, phthalate ester plasticizers such as diisononyl phthalate (DINP) and dioctyl phthalate (DOP), as well as non-phthalate plasticizers, are used.

[0096] Any known printing method may be used. The ink composition of this embodiment is suitable for gravure printing or flexographic printing, and is more suitable for gravure printing.

[0097] A laminate can be obtained by printing on a plastic film substrate for wallpaper using the ink composition of this embodiment.

[0098] The printed layer formed using the ink composition of this embodiment has high processability in both mechanical and chemical embossing.

[0099] In mechanical embossing, a cooled embossing roll is pressed against a plastic film that has been softened by heating and foaming to perform physical embossing. The heating temperature is, for example, 130 to 180°C. At this time, the printed layer is subjected to rapid tensile stress, but in the printed layer formed using the ink composition of this embodiment, the occurrence of film breakage and cracks is suppressed even at the bottom and rising portions of deep embossed grooves.

[0100] In chemical embossing, the foam inhibitor blended into the ink composition migrates into the plastic film during the heating process, locally inhibiting the decomposition reaction of the foaming agent. In this method, a steep step is created at the boundary between the foamed and non-foamed areas. However, the printed layer obtained from the ink composition of this embodiment has excellent leveling properties, allowing the inhibitor to penetrate uniformly, thus enabling the formation of a sharp and precise textured design. Furthermore, even at the formed steep step, the printed layer follows the shape changes of the substrate and is firmly adhered without peeling or cracking.

[0101] The wallpaper of this embodiment comprises the laminate described above. The wallpaper may further have a coating layer on the surface of the printed layer of the laminate. Examples of the coating layer include a layer made of treatment agents such as an antifouling agent, a matting agent, and an antibacterial agent.

[0102] <Mechanism of Action> The wallpaper ink composition of the present invention comprises an aqueous (meth)acrylic resin (A), an ethylene-vinyl acetate copolymer resin emulsion (B), a free neutralizing agent (C), an extender pigment (D), and an aqueous medium. As shown in the examples described below, by including an (meth)acrylic resin emulsion (A1) with a glass transition temperature of 60 to 100°C as the aqueous (meth)acrylic resin (A), the abrasion resistance and heat resistance of the resulting printed layer are improved. Adhesion to the wallpaper substrate is also improved. Furthermore, by including an ethylene-vinyl acetate copolymer resin emulsion (B), the abrasion resistance of the resulting printed layer is further improved. In particular, by including an ethylene-vinyl acetate copolymer resin emulsion (B) with an elongation of 600% or more, the abrasion resistance of the resulting printed layer is further improved, as is the leveling properties. Furthermore, by keeping the content of the water-based (meth)acrylic resin (A) and the ethylene-vinyl acetate copolymer resin emulsion (B) within a specific range, the abrasion resistance, embossability, and leveling properties of the resulting printed layer are improved. In addition, adhesion to wallpaper substrates is also improved. [Examples]

[0103] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist of the invention. Unless otherwise specified, "%" means "mass%".

[0104] [Raw materials used] <(Meth)acrylic resin emulsion (A1)> A1-1: Solid content: 50%, Glass transition temperature: 70°C, Core:Shell (mass ratio) = 80:20, Acid value: 24 mg KOH / g, Weight-average molecular weight: 193,000, Average particle size: 163 nm. A1-2: Solid content: 45%, Glass transition temperature: 53°C, Core:Shell (mass ratio) = 80:20, Acid value: 12 mg KOH / g, Weight-average molecular weight: 145,000, Average particle size: 190 nm. A1-3: Solid content: 40%, Glass transition temperature: 105℃, Core:Shell ratio = 70:30, Acid value: 20mgKOH / g, Weight-average molecular weight: 210,000, Average particle size: 205nm.

[0105] <(Meth)acrylic resin dispersion (A2)> A2-1: Solid content: 45%, Glass transition temperature: 82°C, Acid value: 0 mg KOH / g, Weight-average molecular weight: 130,000, Average particle size: 220 nm.

[0106] <Vinyl chloride-(meth)acrylic copolymer resin (A3)> A3-1: Solid content: 54%, Glass transition temperature: 46°C, Minimum film formation temperature: 60°C, Acid value: 4 mg KOH / g, Weight-average molecular weight: 188,000, Average particle size: 200 nm. A3-2: Solid content: 40%, Glass transition temperature: 70°C, Minimum film formation temperature: >80°C, Acid value: 3 mg KOH / g, Weight-average molecular weight: 215,000, Average particle size: 330 nm.

[0107] <Ethylene-vinyl acetate copolymer resin emulsion (B)> · B-1: Ethylene-vinyl acetate-(meth)acrylic copolymer resin emulsion, manufactured by Sumitomo Chemical Co., Ltd., product name "Sumikaflex 900HL", solids content: 60%, elongation: >1500%, glass transition temperature: -20℃. B-2: Ethylene-vinyl acetate copolymer resin emulsion, manufactured by Sumitomo Chemical Co., Ltd., product name "Sumikaflex S-401HQ", solids content: 55%, elongation: 850%. B-3: Ethylene-vinyl acetate copolymer resin emulsion, manufactured by Sumitomo Chemical Co., Ltd., product name "Sumikaflex S-408HQE", solids content: 50%, elongation: 650%. B-4: Ethylene-vinyl acetate copolymer resin emulsion, manufactured by Sumitomo Chemical Co., Ltd., product name "Sumikaflex S-400HQ", solids content: 55%, elongation: 550%.

[0108] <(Free) Neutralizing agent (C)> C-1:2-amino-2-methyl-1-propanol, manufactured by ANGUS, product name "AMP-90", active ingredient: 90%.

[0109] <Extender pigment (D)> D-1: Silica, manufactured by Tosoh Silica Co., Ltd., product name "Nipsil E-1030", average particle size: 8.3 μm.

[0110] <Aqueous medium> Isopropanol. In Tables 1-3, it is abbreviated as "IPA". ·Purified water.

[0111] <Optional ingredients> Leveling agent, manufactured by Kawaken Fine Chemical Co., Ltd., product name "Acetylenel E13T", solid content: >98%. • Wax, manufactured by GSI Creos Corporation, product name "Siltech C-4445-65", solid content: 65%, average particle size: 6.3 μm. • Defoaming agent, manufactured by Sunopco Corporation, product name "SN Deformer 382", solid content: 50%. • Urethane-associated thickener, manufactured by Sunopco Co., Ltd., product name "SN Thickener 623N", solids content: 30%. In Tables 1-3, it is referred to as "urethane-associated thickener". • Acrylic thickener, manufactured by Sunopco Co., Ltd., product name "SN Thickener 636", solids content: 30%. In Tables 1-3, it is referred to as "acrylic thickener". • Release agent, PEG6000, solids content: 100%.

[0112] [Examples 1-20, Comparative Examples 1-8] <Preparation of wallpaper ink composition> According to the compositions shown in the table, (meth)acrylic binder resin (A), ethylene-vinyl acetate copolymer resin emulsion (B), (free) neutralizing agent (C), extender pigment (D), aqueous medium, and optional components were mixed, and the resulting mixture was kneaded in a paint shaker to obtain an ink composition. In Tables 1-3, the content of (meth)acrylic resin emulsion (A1), (meth)acrylic resin dispersion (A2), vinyl chloride-(meth)acrylic copolymer resin (A3), ethylene-vinyl acetate copolymer resin emulsion (B), and other components in the composition [mass %] column represents the ratio of solids (mass %) to the total mass of the ink composition (however, for components whose active ingredients are not solids, such as free neutralizing agents and aqueous mediums, it represents the content of the active ingredient). Also, the water "residue" in the aqueous medium is the amount that makes the total mass of the ink composition 100%. Also, a blank space means that the component was not included. The free neutralizing agent content refers to the amount of neutralizing agent that is not used to neutralize acidic groups such as carboxyl groups in the resin and remains free. This free neutralizing agent comes from neutralizing agents contained in (meth)acrylic resin emulsion (A1) and ethylene-vinyl acetate copolymer resin emulsion (B) other than the solid content, and from the additionally added neutralizing agent (C-1) mentioned above. In Tables 1 to 3, the "Solid Content Base" column refers to the content of solids such as aqueous (meth)acrylic resin (A) and ethylene-vinyl acetate copolymer resin emulsion (B) relative to the total mass of solids in the ink composition. For example, the content of (A) refers to the content of aqueous (meth)acrylic resin (A) relative to the total mass of solids in the ink composition. [(A1) + (A2)] / (A) is the ratio of (meth)acrylic resin emulsion (A1) and (meth)acrylic resin dispersion (A2) to the content of aqueous (meth)acrylic resin (A), expressed as a percentage.

[0113] <Creating printed materials> A mixture was prepared by mixing 95 parts by mass of the prepared ink composition with 5 parts by mass of a blue ink composition (manufactured by Dainichi Seika Kogyo Co., Ltd., product name "Hydric WP 63 Blue (D)") and diluting the mixture with water until the viscosity at 20°C, as measured using a Zahn cup #3, was 18 seconds, thereby preparing a printing ink. Using a gravure printing press equipped with a Helio 175 line / inch gravure engraving plate (manufactured by Matsuo Sangyo Co., Ltd., product name "K Printing Proofer"), the prepared printing ink was applied to the surface of the foaming agent-containing polyvinyl chloride resin layer of a wallpaper sheet (paper / foaming agent-containing polyvinyl chloride resin laminate, thickness: 0.25 mm). The sheet was then dried at 80°C for 30 seconds to produce a printed material.

[0114] <Evaluation of abrasion resistance> The resulting printed material was subjected to a foaming treatment with 220°C hot air for 40 seconds. Afterward, the printed surface was subjected to an abrasion resistance test using a JSPS-type friction fastness tester (manufactured by Tester Sangyo Co., Ltd., product name "AB-301"), where a white cloth (metal cloth No. 3) with a 200gf load was rubbed back and forth 100 times. The staining of the white cloth (metal cloth No. 3) was then evaluated for abrasion resistance according to the friction color fading criteria specified in JIS A6921:2014. A score of 3-5 indicates excellent abrasion resistance. 5: The contamination is equivalent to level 5 on the contamination grayscale. 4: The contamination is equivalent to level 4 on the contamination grayscale. 3: The contamination is equivalent to level 3 on the contamination grayscale. 2: The contamination is equivalent to level 2 on the contamination grayscale. 1: Contamination exceeding level 1 on the grayscale for contamination.

[0115] <Evaluation of embossability> The resulting printed material was subjected to a foaming treatment with 220°C hot air for 40 seconds. Subsequently, using a heating and cooling molding machine (manufactured by Kodaira Seisakusho Co., Ltd., product name "200KN Heating and Cooling Molding Machine") and a 15% deep embossed plate, the material was processed at 150°C and 6.8 kg / cm². 2After embossing the printed surface under the specified conditions, the printed surface was visually inspected, and its embossability was evaluated according to the evaluation criteria shown below. A score of 3 to 5 indicates excellent embossability. 5: No cracks were found. 4: Minor cracks are slightly visible. 3: Minor cracks are observed. 2: Moderate cracks are observed. 1: Severe cracks were observed.

[0116] <Heat resistance evaluation> The resulting printed material was subjected to a foaming treatment with 220°C hot air for 40 seconds. Subsequently, using a heating and cooling molding machine (manufactured by Kodaira Seisakusho Co., Ltd., product name "200KN Heating and Cooling Molding Machine") and a metal mirror plate, the material was processed at 150°C and 6.8 kg / cm². 2 After heat pressing the printed surface under the specified conditions, the printed surface was visually inspected, and its heat resistance was evaluated according to the evaluation criteria shown below. A score of 3 to 5 indicates excellent heat resistance. In cases 1 to 4 below, if two evaluation criteria apply regarding the area ratio and discoloration, the lower-numbered evaluation criterion is adopted. For example, if the area ratio of the printed layer transferred to the metal mirror plate is greater than 0% and 5% or less, and yellow discoloration is observed, it would fall under both 4 and 2, but in this case, 2 is selected. 5: The area of ​​the printed layer transferred to the metal mirror plate is 0%, and no discoloration is observed. 4: The percentage of the printed layer transferred to the metal mirror plate is greater than 0% and less than or equal to 5%, or a very slight yellow discoloration is observed. 3: The area of ​​the printed layer transferred to the metal mirror plate is greater than 5% and less than or equal to 10%, or a slight yellow discoloration is observed. 2: The area of ​​the printed layer transferred to the metal mirror plate is greater than 10% and less than or equal to 20%, or yellow discoloration is observed. 1: The area of ​​the printed layer that has transferred to the metal mirror plate exceeds 20%, or brown discoloration is observed.

[0117] <Evaluation of leveling ability> The printed surface of the obtained printed material was visually inspected, and the leveling properties were evaluated according to the evaluation criteria shown below. A score of 3 to 5 indicates excellent leveling performance. 5: The printed coating is uniform. 4: Very slight unevenness can be observed in the printed coating. 3: Slight unevenness can be observed in the printed coating. 2: Unevenness in the printed coating is observed. 1: Significant unevenness in the printed coating is observed.

[0118] <Evaluation of adhesion to the substrate> The resulting printed material was subjected to a foaming treatment with 220°C hot air for 40 seconds. After that, cellophane adhesive tape (manufactured by Nichiban Co., Ltd.) was applied to the printed surface of the printed material, and then the cellophane adhesive tape was promptly peeled off. The condition of the printed layer remaining on the substrate was visually inspected, and the adhesion of the printed layer to the substrate was evaluated according to the following evaluation criteria. 5: The printed layer has not peeled off at all. 4. The ratio of the area of ​​the peeled-off printed layer to the total area of ​​the printed layer is greater than 0% and 5% or less. 3. The ratio of the area of ​​the peeled-off printed layer to the total area of ​​the printed layer is greater than 5% and less than or equal to 20%. 2: The ratio of the area of ​​the peeled-off printed layer to the total area of ​​the printed layer is greater than 20% and less than or equal to 50%. 1: The area of ​​the peeled-off printed layer is more than 50% of the total area of ​​the printed layer.

[0119] <Evaluation of resolubility> A Helio 175 line / inch gravure engraving plate, still coated with printing ink immediately after printing, was dried at 80°C for 10 seconds. One drop of water was then added and allowed to stand for 10 seconds. Afterward, the water was wiped off, the condition of the plate at the drop site was checked, and the resolubility was evaluated according to the following evaluation criteria. 5. No ink remains on the printing plate. 4: A very small amount of ink remains on the printing plate. 3: A small amount of ink remains on the printing plate. 2: Ink remains on the printing plate. 1: The ink has hardened on the printing plate and cannot be wiped off.

[0120] [Table 1]

[0121] [Table 2]

[0122] [Table 3]

[0123] The printed layers obtained from the ink compositions of Examples 1 to 20 exhibited excellent abrasion resistance, embossability, heat resistance, and leveling properties. The printed layers obtained from the ink compositions of Comparative Examples 1 to 8 exhibited inferiority in at least one of the following properties: abrasion resistance, embossability, heat resistance, and leveling properties. [Industrial applicability]

[0124] The wallpaper ink composition of the present invention is useful because the resulting printed layer has excellent abrasion resistance, embossability, heat resistance, and leveling properties.

Claims

1. A wallpaper ink composition comprising an aqueous (meth)acrylic resin (A), an ethylene-vinyl acetate copolymer resin emulsion (B), a free neutralizing agent (C), an extender pigment (D), and an aqueous medium, The aqueous (meth)acrylic resin (A) comprises either or both of a (meth)acrylic resin emulsion (A1) and a (meth)acrylic resin dispersion (A2) having a glass transition temperature of 60 to 100°C. The elongation of the ethylene-vinyl acetate copolymer resin emulsion (B) is 600% or more. The solid content of the aqueous (meth)acrylic resin (A) is 65.0 to 82.0% by mass relative to the total mass of solids in the wallpaper ink composition. A wallpaper ink composition wherein the solid content of the ethylene-vinyl acetate copolymer resin emulsion (B) is 0.5 to 10.0% by mass relative to the total mass of the solid content of the wallpaper ink composition.

2. The wallpaper ink composition according to claim 1, wherein the total solid content of the (meth)acrylic resin emulsion (A1) and the (meth)acrylic resin dispersion (A2) is 20 to 80% by mass relative to the total mass of solid content of the aqueous (meth)acrylic resin (A).

3. The wallpaper ink composition according to claim 1, wherein the aqueous (meth)acrylic resin (A) comprises a vinyl chloride-(meth)acrylic copolymer resin (A3), and the glass transition temperature of the vinyl chloride-(meth)acrylic copolymer resin (A3) is less than 60°C.

4. The wallpaper ink composition according to claim 1, wherein the ethylene-vinyl acetate copolymer resin emulsion (B) comprises an ethylene-vinyl acetate-(meth)acrylic copolymer resin emulsion.

5. The wallpaper ink composition according to claim 1, further comprising a thickening agent, wherein the thickening agent comprises a urethane association type thickening agent.

6. The wallpaper ink composition according to claim 1, further comprising wax.

7. The wallpaper ink composition according to claim 1, further comprising an acetylenediol-based leveling agent.

8. The wallpaper ink composition according to claim 1, wherein the free neutralizing agent (C) comprises ammonia or an amine-based neutralizing agent, and the content of the free ammonia and the amine-based neutralizing agent is 0.2 to 2.5% by mass relative to the total mass of the wallpaper ink composition.

9. A wallpaper ink composition according to any one of claims 1 to 8, for use in gravure printing.

10. A laminate comprising a wallpaper substrate and a printed layer formed on one surface of the wallpaper substrate using the wallpaper ink composition described in any one of claims 1 to 8.

11. A laminate comprising a wallpaper substrate and a printed layer formed on one surface of the wallpaper substrate using the wallpaper ink composition described in claim 9.

12. Wallpaper comprising the laminate described in claim 10.

13. Wallpaper comprising the laminate described in claim 11.

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