Ink composition for wallpaper, laminate, and wallpaper

Abstract

To provide a wallpaper ink composition that exhibits excellent leveling properties, setting properties, stability, adhesion of the resulting printed layer to the wallpaper substrate, and heat resistance. [Solution] A wallpaper ink composition comprising a binder resin (A), an acetylenediol-based leveling agent (B), a glycol-based solvent (C), a free neutralizing agent (D), and an aqueous medium, wherein (A) comprises a (meth)acrylic resin emulsion (A1), the mass ratio of the core portion to the shell portion of (A1) is 90 / 10 to 50 / 5, and the Tg is 60 to 100°C, and (C) comprises at least one selected from butyl cellosolve, etc., the solid content of (A) is 45 to 80% by mass of the total mass of the solid content of the composition, the solid content of (A1) is 45% by mass or more of the total mass of the solid content of (A), the solid content of (B) is 0.2 to 6.0% by mass of the total mass of the composition, and the content of (C) is 0.3 to 7.5% by mass of the total mass of the composition.

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 residences and the like is produced by laminating a plastic film such as a vinyl chloride resin on a base material such as paper or nonwoven fabric, and performing printing on the surface thereof to impart design properties. In recent years, designs of wallpaper have been diversified, and the importance of ink compositions using gravure printing or the like has been increasing in order to express high-definition patterns and deep textures.

[0003] Conventionally, as inks for wallpaper, those in which a synthetic resin is used as a binder and a pigment and various additives are blended therewith are known. In the wallpaper manufacturing process, heat foaming treatment and embossing (embossing by a mold) are performed after printing, so the ink composition is required to have various properties capable of withstanding these severe processing conditions. For example, properties such as remaining adhered to the wallpaper base material even after the heat foaming treatment (adhesion to the wallpaper base material), no migration of the ink layer to the mold during heat molding, and no discoloration of the ink layer (hereinafter also referred to as "heat resistance") are required.

[0004] In addition, leveling property is also one of the properties required for wallpaper inks. With improved leveling property, the gradation of gradients becomes smoother, and it becomes easier to achieve intended pattern reproducibility and a uniform, beautiful smooth surface. Furthermore, setting property and stability are also required.

[0005] Patent Document 1 discloses an aqueous printing ink composition for wallpaper (wallpaper ink) characterized by containing an inorganic acid and / or organic acid, (B) 7 to 50% by weight of a vinyl monomer having an amino group having a specific structure in its molecule, 1 to 30% by weight of a vinyl monomer having an acetylacetoxy group in its molecule, and the remainder being 20 to 92% of other copolymerizable vinyl monomers, after copolymerization of the monomer mixture, an acrylic resin that is water-soluble 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 project] [Problems that the invention aims to solve]

[0009] However, conventional wallpaper inks described in Patent Documents 1 to 3 do not satisfy all of the following requirements at a high level: leveling, setting ability, stability, adhesion of the resulting printed layer to the substrate, and heat resistance. In particular, it is difficult to achieve both setting ability and stability.

[0010] The present invention aims to provide a wallpaper ink composition that is excellent in leveling properties, setting properties, stability, adhesion of the resulting printed layer to a wallpaper substrate, and heat resistance; a laminate comprising a printed layer formed using the above wallpaper ink composition; and wallpaper comprising the above laminate. [Means for solving the problem]

[0011] The present invention has the following aspects. [1] A wallpaper ink composition comprising a binder resin (A), an acetylenediol-based leveling agent (B), a film-forming aid (C), a free neutralizing agent (D), and an aqueous medium, The binder resin (A) comprises (meth)acrylic resin emulsion (A1), The (meth)acrylic resin emulsion (A1) has a core-shell structure, a mass ratio of core portion / shell portion of 90 / 10 to 50 / 50, and a glass transition temperature of 60 to 100°C. The film-forming aid (C) comprises at least one selected from the group consisting of butyl cellosolve, diethylene glycol butyl ether, polypropylene glycol methyl ether, propylene glycol methyl ether, propylene glycol-n-propyl ether, dipropylene glycol-n-butyl ether, dipropylene glycol methyl ether, tripropylene glycol methyl ether, dipropylene glycol dimethyl ether, tripropylene glycol-n-butyl ether, and texanol. The solid content of the binder resin (A) is 45 to 80% by mass relative to the total mass of solids in the wallpaper ink composition. The solid content of the (meth)acrylic resin emulsion (A1) is 45% by mass or more relative to the total mass of the solid content of the binder resin (A). The solid content of the acetylenediol-based leveling agent (B) is 0.2 to 6.0% by mass relative to the total mass of the wallpaper ink composition. A wallpaper ink composition wherein the content of the film-forming aid (C) is 0.3 to 7.5% by mass relative to the total mass of the wallpaper ink composition. [2] The wallpaper ink composition according to [1], further comprising a thickening agent, wherein the thickening agent comprises a urethane association type thickening agent. [3] The wallpaper ink composition according to [1] or [2], wherein the free neutralizing agent (D) comprises at least one selected from the group consisting of ammonia and amine-based neutralizing agents, and the content of the free ammonia and amine-based neutralizing agent is 0.2 to 2.5% by mass with respect to the total mass of the wallpaper ink composition. [4] A wallpaper ink composition according to any of [1] to [3], for gravure printing. [5] 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 of [1] to [3]. [6] 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 [4]. Wallpaper comprising the laminate described in [7] [5]. Wallpaper comprising the laminate described in [8] [6]. [Effects of the Invention]

[0012] According to the present invention, it is possible to provide a wallpaper ink composition that is excellent in leveling properties, setting properties, stability, adhesion of the resulting printed layer to a wallpaper substrate, and heat resistance; a laminate comprising a printed layer formed using the above wallpaper ink composition; and wallpaper comprising the above laminate. [Modes for carrying out the invention]

[0013] Hereinafter, the present invention will be described in detail. The following embodiments are merely illustrative for explaining the present invention, and are not intended to limit the present invention only to these embodiments. The present invention can be implemented in various aspects without departing from the gist thereof. The definitions in the present specification are as follows. "Aqueous medium" means a liquid medium containing water. "Liquid medium" means a volatile liquid such as water and an organic solvent. The content of binder resin such as (meth)acrylic resin emulsion is all calculated on a solid content basis. The "solid content" of the ink composition for wallpaper refers to components excluding the liquid medium among the components contained in the ink composition for wallpaper, which are components that finally form an 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 binder resin. "Coating film" refers to a coating film formed by the ink composition for wallpaper of the present invention. That is, in the present specification, "printed layer" and "coating film" have the same meaning. "(Meth)acrylate" is a general term for "acrylate" and "methacrylate". "(Meth)acrylic acid" is a general term for "acrylic acid" and "methacrylic acid".

[0014] The glass transition temperature of the binder resin 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 line of the endothermic curve in the curve (DSC curve) obtained by heating 10 mg of the solid content of the binder resin from -100°C to 160°C at a rate of 20°C / min.

[0015] The acid value of the binder resin is the amount of potassium hydroxide required to neutralize acid groups such as carboxyl groups per 1 g of the solid content of the sample, expressed in milligrams, and can be measured in accordance with JIS K 5601-2-1:1999.

[0016] <<Ink Composition for Wallpaper>> The ink composition for wallpaper of the present embodiment (hereinafter also simply referred to as "ink composition") contains a binder resin (A), an acetylenediol-based leveling agent (B), a film-forming auxiliary (C), a free neutralizing agent (D), and an aqueous medium. The ink composition may further contain a thickener. The ink composition may further contain a color pigment. The ink composition may further contain an extender pigment. The ink composition may further contain other components besides the binder resin (A), the acetylenediol-based leveling agent (B), the film-forming auxiliary (C), the aqueous medium, the thickener, the color pigment, and the extender pigment.

[0017] <Binder Resin (A)> The binder resin (A) contains a (meth)acrylic resin emulsion (A1). The binder resin (A) may further contain other binder resins besides the (meth)acrylic resin emulsion (A1).

[0018] ((Meth)acrylic Resin Emulsion (A1)) The (meth)acrylic resin emulsion (A1) is an emulsion-type (meth)acrylic resin. The (meth)acrylic resin emulsion (A1) has units based on (meth)acrylate. Note that a resin having units based on (meth)acrylate and units based on vinyl chloride is defined as a vinyl chloride resin emulsion (A2) described later. The (meth)acrylic resin emulsion (A1) has a core-shell structure. The core part of the core-shell structure is preferably a hydrophobic (meth)acrylic resin. The shell part of the core-shell structure is preferably a hydrophilic (meth)acrylic resin. The core part and the shell part may be bonded via a crosslinking agent.

[0019] 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.

[0020] 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 carboxyl group-containing monomers and monomers other than carboxyl group-containing monomers. The monomers other than carboxyl group-containing monomers can be any monomer that does not have a carboxyl group, and may be (meth)acrylates or monomers other than (meth)acrylates.

[0021] 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.

[0022] 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.

[0023] 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.

[0024] 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.

[0025] 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.

[0026] In the (meth)acrylic resin emulsion (A1), the mass ratio expressed as core portion / shell portion is 90 / 10 to 50 / 50, preferably 90 / 10 to 60 / 40, and more preferably 90 / 10 to 70 / 30. If the core portion is greater and the shell portion is less than the above range, the stability and resolubility of the ink composition will decrease. If the core portion is less and the shell portion is greater than the above range, the heat resistance and adhesion to the substrate of the resulting printed layer will decrease.

[0027] The glass transition temperature of the (meth)acrylic resin emulsion (A1) is 60 to 100°C, preferably 62 to 90°C, and more preferably 65 to 85°C. If the glass transition temperature of the (meth)acrylic resin emulsion (A1) is below the above lower limit, the heat resistance and adhesion to the substrate of the resulting printed layer will decrease. The resolubility of the ink composition will also decrease slightly. If the resolubility of the ink composition is low, when the aqueous ink remaining in the cells of the gravure plate or on the flexographic plate dries, it can cause transfer defects. Resolubility refers to the ability to redissolve the ink composition in the aqueous medium that constitutes the ink composition before it dries and causes transfer defects. If the glass transition temperature of the (meth)acrylic resin emulsion (A1) is above the above upper limit, the adhesion to the substrate of the resulting printed layer will decrease. The setting ability of the ink composition will also decrease slightly.

[0028] The acid value of the (meth)acrylic resin emulsion (A1) is preferably 60 mgKOH / g or less, more preferably 55 mgKOH / g or less, even more preferably 50 mgKOH / g or less, and may also 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 alkali resistance and water friction resistance of the resulting printed layer will be slightly reduced.

[0029] The weight-average molecular weight of the (meth)acrylic resin emulsion (A1) 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) 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) is above the upper limit, the stability of the ink composition will be slightly reduced. The weight-average molecular weight of (meth)acrylic resin emulsion (A1) 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.

[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 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 (meth)acrylic resin emulsion (A1) may be one produced by a known manufacturing method or a commercially available product. In the production of (meth)acrylic resin emulsion (A1), the polymerization method of the monomers 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. (Meth)acrylic resin emulsion (A1) may be used alone or in combination of two or more types.

[0032] (Other binder resins) Other binder resins include, for example, water-based resins other than (meth)acrylic resin emulsion (A1). "Water-based resins" is a general term encompassing both "water-soluble resins" and "water-dispersible resins (resin emulsions, resin dispersions)." Examples of aqueous resins include aqueous vinyl chloride resins, aqueous urethane resins, and aqueous polyolefin resins. Among these, aqueous vinyl chloride resins are preferred. When an ink composition contains an aqueous vinyl chloride resin, the leveling properties and adhesion of the printed layer to the substrate tend to improve.

[0033] As the aqueous vinyl chloride resin, vinyl chloride resin emulsion (A2) is preferred. The vinyl chloride resin may be a homopolymer of vinyl chloride, or a copolymer of vinyl chloride and another monomer other than vinyl chloride (vinyl chloride copolymer resin). The vinyl chloride resin emulsion (A2) may be a vinyl chloride copolymer resin emulsion having a core-shell structure, or a vinyl chloride resin emulsion in an emulsified state containing an emulsifier. In a vinyl chloride copolymer resin emulsion having a core-shell structure, the core and shell parts may be bonded together by a crosslinking agent.

[0034] As for other monomers, at least one selected from the group consisting of (meth)acrylate, (meth)acrylic acid, and vinylidene chloride is preferred. Examples of (meth)acrylates include the (meth)acrylate described in (meth)acrylic resin emulsion (A1). One type of (meth)acrylate may be used alone, or two or more types may be used in combination.

[0035] In addition to (meth)acrylate, (meth)acrylic acid, or vinylidene chloride, other monomers that may be used include carboxyl group-containing monomers other than (meth)acrylic acid, ethylene, vinyl acetate, vinyl alcohol, and monomers other than (meth)acrylate and carboxyl group-containing monomers as described in (meth)acrylic resin emulsion (A1). The vinyl chloride copolymer resin emulsion (A2) preferably has units based on (meth)acrylic acid or a carboxyl group-containing monomer other than (meth)acrylic acid.

[0036] Examples of carboxyl group-containing monomers other than (meth)acrylic acid include the carboxyl group-containing monomers described in (meth)acrylic resin emulsion (A1). The carboxyl group-containing monomer may be used alone or in combination of two or more types.

[0037] The content of units based on vinyl chloride relative to the total mass of solids in the vinyl chloride resin emulsion (A2) may be, for example, 20-100% by mass, 50-100% by mass, or 80-100% by mass.

[0038] The weight-average molecular weight of the vinyl chloride resin emulsion (A2) is preferably 30,000 to 1,000,000, more preferably 50,000 to 800,000, preferably 70,000 to 700,000, and even more preferably 90,000 to 600,000. If the weight-average molecular weight of the vinyl chloride resin emulsion (A2) is below the lower limit, the heat resistance will be slightly reduced. If the weight-average molecular weight of the vinyl chloride resin emulsion (A2) is above the upper limit, the stability will be slightly reduced.

[0039] The glass transition temperature of the vinyl chloride resin emulsion (A2) is preferably 40 to 80°C, more preferably 45 to 75°C, even more preferably 50 to 70°C, and particularly preferably 60 to 68°C. If the glass transition temperature of the vinyl chloride resin emulsion (A2) 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 resin emulsion (A2) is above the upper limit, the adhesion of the resulting printed layer to the substrate will be slightly reduced.

[0040] The chlorine content of the vinyl chloride resin emulsion (A2) is preferably 30 to 70% by mass, more preferably 35 to 65% by mass, and even more preferably 40 to 60% by mass. If the chlorine content of the vinyl chloride resin emulsion (A2) is below the lower limit, the leveling properties will be slightly reduced. If the chlorine content of the vinyl chloride resin emulsion (A2) is above the upper limit, the dry friction resistance will be slightly reduced. The chlorine content is calculated as the ratio of the atomic weight of chlorine to the total molecular weight of the resin.

[0041] The vinyl chloride resin emulsion (A2) may be one produced by a known manufacturing method or a commercially available product. The vinyl chloride resin emulsion (A2) may be used alone or in combination of two or more types.

[0042] <Acetylenediol-based leveling agent (B)> By including an acetylenediol-based leveling agent (B) in the ink composition, the leveling properties of the resulting printed layer can be improved. Acetylenediol-based leveling agents (B) may be used individually or in combination of two or more types.

[0043] Furthermore, acetylenediol-based leveling agent (B) may be used in combination with other leveling agents. Examples of other leveling agents include silicone-based leveling agents such as polyether-modified polydimethylsiloxane and polyester-modified polydimethylsiloxane, and (meth)acrylic-based leveling agents such as polyacrylate. The other leveling agents may be used individually or in combination of two or more.

[0044] <Film-forming aid (C)> Film-forming aid (C) is used to lower the minimum film-forming temperature of the ink composition, thereby forming a uniform and strong printed layer even at low temperatures. The film-forming aid (C) includes at least one selected from the group consisting of butyl cellosolve, diethylene glycol butyl ether, polypropylene glycol methyl ether, propylene glycol methyl ether, propylene glycol-n-propyl ether, dipropylene glycol-n-butyl ether, dipropylene glycol methyl ether, tripropylene glycol methyl ether, dipropylene glycol dimethyl ether, tripropylene glycol-n-butyl ether, and texanol (hereinafter, these are collectively referred to as film-forming aid (C1)). The inclusion of film-forming aid (C1) in the ink composition can improve its setting properties. It is believed that the inclusion of film-forming aid (C1) accelerates the drying of the ink composition immediately after printing, thereby improving its film-forming properties.

[0045] As film-forming aids (C1), butyl cellosolve, diethylene glycol butyl ether, polypropylene glycol methyl ether, propylene glycol-n-propyl ether, dipropylene glycol methyl ether, tripropylene glycol methyl ether, dipropylene glycol dimethyl ether, tripropylene glycol-n-butyl ether, and texanol are preferred due to their excellent film-forming properties. Among these, polypropylene glycol methyl ether, propylene glycol-n-propyl ether, dipropylene glycol-n-butyl ether, and texanol are particularly preferred due to their excellent balance of film-forming properties and plate-clogging properties. The film-forming aid (C1) may be used alone or in combination of two or more types.

[0046] Film-forming aid (C1) may be used in combination with other film-forming aids. Examples of other film-forming aids include glycol derivatives that are liquid at 25°C (excluding film-forming aid (C1)). Examples of glycol derivatives include glycol ethers and glycol esters.

[0047] <Free neutralizing agent (D)> The neutralizing agent is used to neutralize acidic groups (e.g., sulfonic acid groups, carboxyl groups) in the binder resin (A), such as (meth)acrylic resin emulsion (A1), in order to make the resin aqueous. Any excess neutralizing agent is present in the ink composition as free neutralizing agent (D). Examples of neutralizing agents include ammonia; organic amines such as monoethylamine, diethylamine, trimethylamine, triethylamine, triisopropylamine, tributylamine, triethanolamine, methyldiethanolamine, monoethanolamine, dimethylethanolamine, diethylethanolamine, morpholine, N-methylmorpholine, 2-amino-2-methyl-1-propanol, 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, at least one selected from the group consisting of ammonia and amine-based neutralizing agents is preferred, and at least one selected from the group consisting of ammonia, trimethylamine, triethylamine, triethanolamine, and 2-amino-2-methyl-1-propanol is more preferred. The neutralizing agent may be used alone or in combination of two or more types.

[0048] <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 it is a liquid and soluble in water at 25°C, glycols and glycol derivatives are not included in aqueous media in this specification. Glycol derivatives mean glycol ethers and glycol esters. The above glycol derivatives are referred to as film-forming aids (C) in this specification. The above glycol is referred to as one of the other components described later in this specification. Organic solvents may be used individually or in combination of two or more types.

[0049] <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.

[0050] 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 further increasing the viscosity of the ink composition. In addition, the viscosity of the ink composition is further increased by the association of the hydrophilic groups of the thickener with the hydrophilic groups of the emulsion surface of the (meth)acrylic resin emulsion (A1). Examples of hydrophobic groups in association-type thickeners include alkyl groups and phenyl groups. Examples of hydrophilic groups in association-type thickeners include hydroxyl groups, amide groups, and carboxyl groups.

[0051] Examples of urethane-associated thickeners include urethane-modified polyethers and polyether polyol-based urethane prepolymers.

[0052] 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.

[0053] <Coloring pigments> The coloring pigment may be any pigment known as a coloring agent, such as organic pigments or inorganic pigments. Examples of organic pigments include azo pigments such as monoazo and condensed azo; surene pigments such as anthraquinone, perinone, perylene, and thioindigo; phthalocyanine pigments such as phthalocyanine blue and phthalocyanine green; quinacridone pigments; dioxazine pigments; isoindolinone pigments; pyrrolopyrrole pigments; aniline black; and organic fluorescent pigments. Examples of inorganic pigments include ferrocyanides such as Prussian blue, sulfides such as zinc sulfide; oxides such as chromium oxide, zinc oxide, titanium oxide, and iron oxide; hydroxides such as aluminum hydroxide; silicates such as ultramarine; carbon such as carbon black and graphite; metal powders such as aluminum powder, bronze powder, and zinc powder; and calcined pigments. Coloring pigments may be used individually or in combination of two or more types.

[0054] <Body pigments> Extender pigments are solid particles formed from inorganic materials. Examples of extender pigments include barium sulfate, calcium sulfate, calcium carbonate, magnesium carbonate, calcium silicate, magnesium silicate, silica, alumina, zirconia, tin oxide, clay, barite, mica, talc, and kaolin. Among these, silica is preferred from the viewpoint of superior matte finish, design appeal, and cost-effectiveness. Extender pigments may be used individually or in combination of two or more types.

[0055] The average particle size of the extender pigment 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 of the extender pigment is not particularly limited, but for example, it is 1.0 μm or more. If the average particle size of the extender pigment exceeds the above upper limit, the storage stability of the ink composition will be slightly reduced. The average particle size of the extender pigment is, if the average particle size is 100 nm or more, the particle size at 50% of the volume-based cumulative value (D50) in the particle size distribution measured by laser diffraction-scattering, and if the average particle size is less than 100 nm, 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 extender pigment (D) is a commercially available product, and the manufacturer discloses the D50 value measured by laser diffraction-scattering, the above value can be used.

[0056] Commercially available silica can also be used. Examples of commercially available silica 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.

[0057] 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).

[0058] <Other ingredients> Other components include, for example, anti-settling agents, UV absorbers, antioxidants, dispersants, waxes, corrosion inhibitors, defoamers, lubricants, stabilizers, surface modifiers, surfactants, silicone additives, foam inhibitors, corrosion inhibitors, drying agents, release agents, and wetting agents. Examples of drying agents include glycols, which are liquid at 25°C. 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. These other ingredients may be used individually or in combination of two or more.

[0059] <Composition of the ink composition> The solid content of the binder resin (A) is 45 to 80% by mass, preferably 48.5 to 78.0% by mass, more preferably 49.0 to 70.0% by mass, and even more preferably 50.0 to 60.0% by mass, based on the total mass of solids in the ink composition. If the content of binder resin (A) is below the lower limit, the leveling properties will decrease. If the content of binder resin (A) exceeds the upper limit, the leveling properties will decrease.

[0060] The solid content of the binder resin (A) is preferably 20 to 50% by mass, more preferably 22 to 40% by mass, and even more preferably 25 to 35% by mass, relative to the total mass of the ink composition. If the content of binder resin (A) is below the lower limit, the leveling properties will be slightly reduced. If the content of binder resin (A) is above the upper limit, the leveling properties will be slightly reduced.

[0061] The solid content of the (meth)acrylic resin emulsion (A1) is 45% by mass or more, preferably 50% by mass or more, more preferably 65% ​​by mass or more, even more preferably 80% by mass or more, and may be 100% by mass, based on the total mass of solid content of the binder resin (A). If the content of (meth)acrylic resin emulsion (A1) is below the above lower limit, the heat resistance of the resulting printed layer will decrease.

[0062] When the binder resin (A) contains a vinyl chloride resin emulsion (A2), the solid content of the vinyl chloride resin emulsion (A2) is preferably 0.5 to 55% by mass, more preferably 1.0 to 30% by mass, and even more preferably 2.0 to 10% by mass, relative to the total mass of the solid content of the binder resin (A). If the content of the vinyl chloride resin emulsion (A2) is below the lower limit, the leveling properties and the adhesion of the printed layer to the wallpaper substrate will be slightly reduced. If the content of the vinyl chloride resin emulsion (A2) exceeds the upper limit, the heat resistance of the printed layer will be slightly reduced.

[0063] The solid content of the acetylenediol-based leveling agent (B) is 0.2 to 6.0% by mass relative to the total mass of the ink composition, preferably 0.3 to 4.0% by mass, more preferably 0.4 to 3.0% by mass, and even more preferably 0.5 to 2.0% by mass. If the content of the acetylenediol-based leveling agent (B) is below the lower limit, the leveling performance will decrease. If the content of the leveling agent exceeds the upper limit, the setting performance will decrease.

[0064] The content of film-forming aid (C) is 0.3 to 7.5% by mass relative to the total mass of the ink composition, preferably 1.0 to 7.0% by mass, more preferably 2.0 to 6.5% by mass, and even more preferably 4.0 to 6.0% by mass. If the content of film-forming aid (C) is below the lower limit, the setting properties will decrease. If the content of film-forming aid (C) exceeds the upper limit, the stability and resolubility will decrease. The content of film-forming aid (C1) is preferably 60% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, and may be 100% by mass, based on the total mass of film-forming aid (C).

[0065] The content of the free neutralizing agent (D) is preferably 0.05 to 3.0% by mass, more preferably 0.2 to 2.5% by mass, and even more preferably 1.0 to 2.0% by mass, based on the total mass of the ink composition. The neutralizing agent is preferably at least one selected from the group consisting of ammonia and amine-based neutralizing agents. If the content of the free neutralizing agent (D) is below the lower limit, the resolubility will be slightly reduced. If the content of the free neutralizing agent (D) is above the upper limit, the drying properties will be slightly reduced.

[0066] 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.

[0067] When the ink composition contains a thickening agent, the solid content of the thickening agent is preferably 0.01 to 5% by mass, more preferably 0.03 to 3% by mass, and even more preferably 0.05 to 2% by mass, relative to the total mass of the ink composition. A urethane-associated thickening agent is preferred as the thickening agent.

[0068] When the ink composition contains a coloring pigment, the content of the coloring pigment is preferably 1 to 40% by mass, more preferably 3 to 30% by mass, and even more preferably 5 to 20% by mass, relative to the total mass of the ink composition. If the content of the coloring pigment is below the lower limit, the opacity and color development of the resulting printed layer will be slightly reduced. If the content of the coloring pigment exceeds the upper limit, the adhesion of the resulting printed layer to the substrate will be slightly reduced. In addition, the ink fluidity of the ink composition may decrease.

[0069] When the ink composition contains an extender pigment, the extender pigment content is preferably 0.01 to 10% by mass, more preferably 0.05 to 8% by mass, and even more preferably 0.1 to 5% by mass, relative to the total mass of the ink composition. If the extender pigment content is below the lower limit, the ink's transferability, particularly its gradation and leveling properties, will be slightly reduced. If the extender pigment content exceeds the upper limit, the adhesion of the resulting printed layer to the substrate will be slightly reduced. In addition, the ink fluidity of the ink composition may decrease.

[0070] 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.

[0071] <Method for manufacturing wallpaper ink composition> The ink composition of this embodiment can be obtained, for example, by mixing a binder resin (A), an acetylenediol-based leveling agent (B), a glycol-based solvent (C), a neutralizing agent (a free neutralizing agent (D)), an aqueous medium, and optionally one or more of a thickener and other components. The method of mixing each component is not particularly limited, and the components can be mixed by various methods. For example, one method is to dissolve or disperse each component other than the aqueous medium in the aqueous medium. 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.

[0072] <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.

[0073] 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.

[0074] 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.

[0075] 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.

[0076] As plasticizers, phthalate ester plasticizers such as diisononyl phthalate (DINP) and dioctyl phthalate (DOP), as well as non-phthalate plasticizers, are used.

[0077] 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.

[0078] A laminate can be obtained by printing on a plastic film substrate for wallpaper using the ink composition of this embodiment.

[0079] The printed layer formed using the ink composition of this embodiment has high processability in both mechanical and chemical embossing.

[0080] 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.

[0081] 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.

[0082] 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.

[0083] <Mechanism of Action> The wallpaper ink composition of the present invention comprises a binder resin (A), an acetylenediol-based leveling agent (B), a film-forming aid (C), a free neutralizing agent (D), and an aqueous medium. As shown in the examples described below, by including a binder resin (A) containing a (meth)acrylic resin emulsion (A1) in a specific amount, the leveling properties, the heat resistance of the resulting printed layer, and the adhesion to the substrate are improved. Furthermore, by including an acetylenediol-based leveling agent (B) in a specific amount, leveling properties can be improved while ensuring settability. Furthermore, by including a film-forming aid (C) in a specific amount, settability can be improved while ensuring stability. [Examples]

[0084] 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. Examples 23 and 24 are for reference only. Unless otherwise specified, "%" means "mass%".

[0085] [Raw materials used] <(Meth)acrylic resin emulsion (A1)> A1-1: Solids content: 50%, weight-average molecular weight: 193,000, glass transition temperature: 70°C, core / shell ratio: 80 / 20, acid value: 24 mg KOH / g, average particle size: 163 nm. A1-2: Solids content: 50%, weight-average molecular weight: 178,000, glass transition temperature: 70°C, core / shell ratio: 80 / 20, acid value: 24 mg KOH / g, average particle size: 217 nm. A1-3: Solids content: 43%, weight-average molecular weight: 220,000, glass transition temperature: 82°C, core / shell ratio: 90 / 10, acid value: 25 mg KOH / g, average particle size: 236 nm. A1-4: Solids content: 33%, weight-average molecular weight: 169,000, glass transition temperature: 79°C, core / shell ratio: 60 / 40, acid value: 40 mg KOH / g, average particle size: 154 nm. A1-5: Solid content: 32%, weight-average molecular weight: 156,000, glass transition temperature: 74℃, core / shell ratio: 50 / 50, acid value: 39 mg KOH / g, average particle size: 173 nm. A1-6: Solid content: 32%, weight-average molecular weight: 145,000, glass transition temperature: 74°C, core / shell ratio: 40 / 60, acid value: 39 mg KOH / g, average particle size: 155 nm. A1-7: Solids content: 45%, weight-average molecular weight: 171,000, glass transition temperature: 63°C, core / shell ratio: 80 / 20, acid value: 12 mg KOH / g, average particle size: 203 nm. A1-8: Solid content: 40%, weight-average molecular weight: 196,000, glass transition temperature: 99°C, core / shell ratio: 80 / 20, acid value: 25 mg KOH / g, average particle size: 199 nm. A1-9: Solid content: 45%, weight-average molecular weight: 145,000, glass transition temperature: 53°C, core / shell ratio: 80 / 20, acid value: 12 mg KOH / g, average particle size: 190 nm. A1-10: Solids content: 40%, weight-average molecular weight: 210,000, glass transition temperature: 105℃, core / shell ratio: 80 / 20, acid value: 20 mg KOH / g, average particle size: 205 nm.

[0086] <Vinyl chloride resin emulsion (A2)> A2-1: Vinyl chloride-vinylidene chloride copolymer resin emulsion, solids content: 57%, glass transition temperature: 62°C, chlorine content: 45%.

[0087] <Leveling agent (B)> B-1: Acetylenediol-based leveling agent, manufactured by Kawaken Fine Chemical Co., Ltd., product name "Acetylenel E13T", solid content: >98%. B-2: Polyether-modified polysiloxane copolymer, manufactured by EVONIK, trade name "TEGO Glide 410", solids content: 100%.

[0088] <Glycol-based solvent (C)> C-1: Polypropylene glycol methyl ether, no boiling point. C-2: Propylene glycol-n-propyl ether, boiling point: 150°C. C-3: Butyl cellosolve, boiling point: 171°C. C-4: Diethylene glycol butyl ether, boiling point: 231°C. C-5: Dipropylene glycol methyl ether, boiling point: 190°C. C-6: Tripropylene glycol methyl ether, boiling point: 242°C. C-7: Dipropylene glycol dimethyl ether, boiling point: 175°C. C-8: Tripropylene glycol-n-butyl ether, boiling point: 274°C.

[0089] <Neutralizing agent> D-1: 2-amino-2-methyl-1-propanol, manufactured by ANGUS, product name "AMP-90", active ingredient: 90%. D-2: Ammonia water, active ingredient: 28%.

[0090] <Aqueous medium> NPA: n-propanol. ·Water: Purified water.

[0091] <Thickening agent> • UR: Urethane association type thickener, manufactured by Sunopco Corporation, product name "SN Thickener 623N", solids content: 30%. • AC: Acrylic thickener, manufactured by Sunopco Corporation, product name "SN Thickener 636", solids content: 30%.

[0092] <Other optional components> Pigment: Pigment Blue 15:3, manufactured by Dainichi Seika Kogyo Co., Ltd., product name "Cyanine Blue ZCA-350-EP". • Silica: Manufactured by Tosoh Silica Co., Ltd., product name "Nipsil E-1030", average particle size: 8.3 μm. • Pigment dispersant: BYK Corporation, product name "DISPERBYK-190", solids content: 40%. • Antifoaming agent: Manufactured by ADEKA Corporation, product name "ADEKAnate B1016", solids content: 100%.

[0093] [Examples 1-24, Comparative Examples 1-13] <Preparation of Ink Composition> According to the compositions shown in Tables 1-4, a binder resin (A), a leveling agent (B), a film-forming aid (C), a neutralizing agent (free neutralizing agent (D)), an aqueous medium, and any optional components were mixed, and the resulting mixture was kneaded in a paint shaker to obtain an ink composition.

[0094] In Tables 1-4, "NV" indicates solid content (however, for active ingredients that are not solids, such as film-forming aids (C) and free neutralizing agents (D), it refers to the active ingredient). The amount of each component is the solid content (mass%) relative to the total mass of the ink composition (however, for active ingredients that are not solids, it refers to the active ingredient content). The content of free neutralizing agent (D) is the amount of neutralizing agent that is not used to neutralize acidic groups such as carboxyl groups in the resin and is free. This free neutralizing agent comes from neutralizing agents included as non-solid components in the binder resin (A) and neutralizing agents added during the preparation of the ink composition. The "residue" of water is the amount that makes the sum of all components (total amount of ink composition) 100%. A blank space means that the component was not included. The NV base content in the table (content of (A) in NV, content of (B) in NV) refers to the solid content (mass%) of the component relative to the total mass of solids in the ink composition. For example, the content of (A) in NV refers to the content of the binder resin (A) relative to the total mass of solids in the ink composition. The ratio of (A1) in (A) refers to the ratio (mass%) of the solids of (meth)acrylic resin emulsion (A1) relative to the solids of binder resin (A).

[0095] <Creating printed materials> For Example 15 and Comparative Example 5, which do not contain coloring pigments, 95 parts by mass of the ink composition prepared in each example and 5 parts by mass of a blue ink composition (manufactured by Dainichi Seika Kogyo Co., Ltd., product name "Hydric WP 63 Blue (D)") were mixed to obtain a mixture which was then diluted with water to obtain a viscosity of 18 seconds at 20°C as measured using a Zahn cup #3, thereby preparing a printing ink. For the other examples and comparative examples, the ink composition prepared in each example was diluted with water to obtain a viscosity of 18 seconds at 20°C as measured using a Zahn cup #3, thereby preparing a printing ink. Using a gravure printing press (manufactured by Matsuo Sangyo Co., Ltd., product name "K Printing Proofer") equipped with a Helio 175 lines / inch gravure engraving plate, the prepared printing ink was applied to the surface of the foaming agent-containing polyvinyl chloride resin layer of a wallpaper sheet (laminated material of paper / foaming agent-containing polyvinyl chloride resin, thickness: 0.25 mm). The sheet was then dried at 80°C for 30 seconds to produce the printed material.

[0096] <Evaluation of set properties> The printed materials were dried at 80°C for a specified time (5 seconds, 10 seconds, 15 seconds, or 20 seconds) immediately after printing. Afterward, the printed coating was rubbed with a finger to check its condition, and the set was evaluated according to the evaluation criteria shown below. A score of 3 to 5 was considered acceptable. After 5.5 seconds of drying, no peeling of the printed coating by touch was observed. After drying for 4 minutes and 10 seconds, no peeling of the printed coating by touch was observed. After drying for 3 minutes and 15 seconds, no peeling of the printed coating by touch was observed. After drying for 2 minutes and 20 seconds, no peeling of the printed coating by touch was observed. After drying for 1 minute and 20 seconds, the printed coating could be removed by touch.

[0097] <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 its resolubility was evaluated according to the following criteria. A score of 5-3 was considered acceptable. 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.

[0098] <Stability Evaluation> 200g of the ink composition prepared in each example was placed in a poly bottle and left to stand at 40°C for one week. After that, it was filtered using a 100-mesh wire mesh, and the residue remaining on the wire mesh was visually inspected. The stability was then evaluated according to the evaluation criteria shown below. A score of 5 to 3 is considered acceptable. 5: No residue. 4: A very small amount of residue is observed. 3: A small amount of residue is observed. 2: Residue is observed. 1: A large amount of residue was observed.

[0099] <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, it was subjected to a process 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 5 to 3 is considered acceptable. 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.

[0100] <Evaluation of adhesion to the substrate> The resulting printed material was subjected to a foaming treatment with 220°C hot air for 40 seconds. Afterward, cellophane adhesive tape (manufactured by Nichiban Co., Ltd.) was applied to the printed surface of the material. The tape was then quickly removed, and the condition of the remaining printed layer on the substrate was visually inspected. The adhesion of the printed layer to the substrate was evaluated according to the following criteria. A score of 5 to 3 was considered acceptable. 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.

[0101] <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 5 to 3 is considered acceptable. 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.

[0102] The evaluation results are shown in Tables 1-4.

[0103] [Table 1]

[0104] [Table 2]

[0105] [Table 3]

[0106] [Table 4]

[0107] The ink compositions of Examples 1 to 24 exhibited excellent leveling properties, setting properties, stability, adhesion to the substrate of the resulting printed layer, and heat resistance. They also had good resolubility. On the other hand, the ink compositions of Comparative Examples 1 to 13 were inferior in one or more of the following: leveling properties, setting properties, stability, adhesion of the resulting printed layer to the substrate, and heat resistance. Some of the ink compositions were also inferior in terms of resolubility. [Industrial applicability]

[0108] The wallpaper ink composition of the present invention is useful because it has excellent leveling properties, setting properties, stability, adhesion of the resulting printed layer to the wallpaper substrate, and heat resistance.

Claims

1. A wallpaper ink composition comprising a binder resin (A), an acetylenediol-based leveling agent (B), a film-forming aid (C), a free neutralizing agent (D), and an aqueous medium, The binder resin (A) comprises a (meth)acrylic resin emulsion (A1), The (meth)acrylic resin emulsion (A1) has a core-shell structure, a mass ratio of core portion / shell portion of 90 / 10 to 50 / 50, and a glass transition temperature of 60 to 100°C. The film-forming aid (C) comprises at least one selected from the group consisting of butyl cellosolve, diethylene glycol butyl ether, polypropylene glycol methyl ether, propylene glycol methyl ether, propylene glycol-n-propyl ether, dipropylene glycol-n-butyl ether, dipropylene glycol methyl ether, tripropylene glycol methyl ether, dipropylene glycol dimethyl ether, tripropylene glycol-n-butyl ether, and texanol. The solid content of the binder resin (A) is 45 to 80% by mass relative to the total mass of solid content of the wallpaper ink composition. The solid content of the (meth)acrylic resin emulsion (A1) is 45% by mass or more relative to the total mass of the solid content of the binder resin (A). The solid content of the acetylenediol-based leveling agent (B) is 0.2 to 6.0% by mass relative to the total mass of the wallpaper ink composition. The content of the film-forming aid (C) is 0.3 to 7.5% by mass relative to the total mass of the wallpaper ink composition. A wallpaper ink composition wherein the free neutralizing agent (D) comprises at least one selected from the group consisting of ammonia and amine-based neutralizing agents, and the content of the free ammonia and amine-based neutralizing agent is 0.2 to 2.5% by mass relative to the total mass of the wallpaper ink composition.

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

3. A wallpaper ink composition according to claim 1 or 2, for use in gravure printing.

4. 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 1 or 2.

5. 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 3.

6. Wallpaper comprising the laminate described in claim 4.

7. Wallpaper comprising the laminate described in claim 5.

Images