JP7068818B2 - Paints for ink receiving layers, coating films, laminates, active energy ray-curable inks, and paints / ink sets - Google Patents

Description

The present invention is used with an ink receiving layer paint for active energy ray-curable ink, a coating film using the coating material, a laminate having an ink receiving layer composed of the coating film, with the coating material or with the coating material. The present invention relates to an active energy ray-curable ink, and a paint / ink set containing the paint and the active energy ray-curable ink.

Conventionally, a printing method using an inkjet printer has been used to decorate a base material such as plastic or a building board. In the decoration by an inkjet printer, it is general that an ink receiving layer is provided on the base material and printing is performed on the ink receiving layer, instead of printing the ink directly on the base material. In recent years, attention has been paid to ultraviolet curable inks having a short curing time and excellent productivity, and printing systems using ultraviolet curable inks have been developed.

The ink receiving layer to which the ultraviolet curable ink is applied is disclosed in, for example, Patent Documents 1 and 2. More specifically, Patent Document 1 discloses a paint for a receiving layer, which is an acrylic resin emulsion having a calculated glass transition point Tg of 35 to 90 ° C. Further, Patent Document 2 discloses an emulsion paint of a thermoplastic resin containing a cross-linking agent as a paint for a receiving layer.

Japanese Unexamined Patent Publication No. 2010-112073 Japanese Unexamined Patent Publication No. 2013-63570

When printing with UV curable ink is performed on the receiving layer obtained from the conventional paint for receiving layer, the monomer in the UV curable ink remains in the receiving layer in an uncured state, and the receiving layer is concerned. The odor may be generated from the decorated product. Further, when printing is performed using the ultraviolet curable ink, the dots are difficult to spread on the conventional receiving layer, and the color development of the image is difficult to be good.

The present invention has been made in view of the above problems, and is a receiving layer used for printing using an active energy ray-curable ink such as an ultraviolet curable ink, and a monomer remains after the printing. A paint for an ink receiving layer that provides an ink receiving layer that is difficult to handle and has excellent color development properties, a coating film using the coating material, a laminate having an ink receiving layer composed of the coating film, and an activity used with the coating material or with the coating film. It is an object of the present invention to provide a paint / ink set containing an energy ray curable ink, the paint and an active energy ray curable ink.

As a result of diligent studies to achieve the above object, the present inventors have applied a paint using a resin in which the ratio of structural units derived from a monomer having a cyclic structure is 0 to 28% by mass, or the ink absorption rate is high. We have found that the above problems can be solved by a paint that gives a coating film of 100% or less, and have completed the present invention.

That is, the paint for an ink receiving layer according to the first embodiment of the present invention is a paint for an active energy ray-curable ink, which contains an aqueous dispersion of resin particles containing a resin, and is cyclic in the resin. The ratio of structural units derived from structural monomers is 0 to 28% by mass.

In a preferred example of the paint for an ink receiving layer according to the first embodiment of the present invention, the resin contains at least one structural unit derived from an ethylenically unsaturated monomer having a solubility parameter of 9.50 to 13.0. It is a polymer containing 25 to 85% by mass.

The paint for an ink receiving layer according to a second embodiment of the present invention is a paint for an active energy ray-curable ink, and the paint contains an aqueous dispersion of resin particles containing a resin, and is the same as the paint. The ink absorption rate of the coating film made of a dried product is 100% or less.

In a preferred example of the ink receiving layer paint according to the second embodiment of the present invention, the ink absorption rate of the coating film made of a dried product of the paint is 100% or less.

In a preferred example of the paint for an ink receiving layer according to the present invention, crosslinks are present between the molecules of the resin in the resin particles.

In a preferred example of the paint for an ink receiving layer according to the present invention, there is a crosslink between the particles.

The coating film according to the present invention comprises a dried product of the paint according to the present invention.

In a preferred example of the coating film according to the present invention, the elongation rate of the coating film is 10 to 30%.

The laminate according to the present invention includes an ink receiving layer made of a coating film according to the present invention and an ink layer made of a cured product of an active energy ray-curable ink, and the ink layer is placed on the ink receiving layer. It is formed.

The active energy ray-curable ink according to the present invention is used together with the paint according to the present invention or with the coating film according to the present invention.

The paint / ink set according to the present invention includes the paint according to the present invention and the active energy ray-curable ink.

According to the present invention, it is a receiving layer used for printing using an active energy ray-curable ink such as an ultraviolet curable ink, and the monomer does not easily remain after the printing and the ink receiving layer is excellent in color development. A paint for an ink receiving layer, a coating film using the coating film, a laminate having an ink receiving layer composed of the coating film, an active energy ray-curable ink used with the coating material or with the coating film, the coating material and activity. It is possible to provide a paint / ink set containing an energy ray curable ink.

≪Paint for ink receiving layer≫
The paint for an ink receiving layer according to the first embodiment of the present invention is a paint for an active energy ray-curable ink, which contains an aqueous dispersion of resin particles containing a resin, and has a cyclic structure in the resin. The ratio of the structural unit derived from the monomer to have is 0 to 28% by mass. The paint for an ink receiving layer according to a second embodiment of the present invention is a paint for an active energy ray-curable ink, and the paint contains an aqueous dispersion of resin particles containing a resin, and is the same as the paint. The ink absorption rate of the coating film made of a dried product is 100% or less. Each of the paints for an ink receiving layer is a receiving layer used for printing using an active energy ray-curable ink, and provides an ink receiving layer having excellent color development property with less monomer remaining after the printing. Can be done.

The resin is not particularly limited, and is, for example, a polymer containing a structural unit derived from a monomer having no cyclic structure, a polymer containing a structural unit derived from a monomer having no cyclic structure, and a structural unit derived from a monomer having a cyclic structure. Can be mentioned. Each of the structural unit derived from the monomer having no cyclic structure and the structural unit derived from the monomer having a cyclic structure may be used alone or in combination of two or more.

The monomer having no cyclic structure is not particularly limited, and is, for example, a linear or branched unsaturated hydrocarbon, a linear or branched unsaturated carboxylic acid, or a linear or branched unsaturated carboxylic acid. Examples thereof include acid esters, linear or branched unsaturated carboxylic acid amides, and the like. Specific examples of linear or branched unsaturated hydrocarbons include ethylene and propylene. Specific examples of the linear or branched unsaturated carboxylic acid include (meth) acrylic acid.

Specific examples of the linear or branched unsaturated carboxylic acid ester include alkyl (meth) acrylates such as methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate. Alkenyl (meth) acrylates such as allyl (meth) acrylates; 3- (meth) acryloyloxypropyltrialkoxysilanes such as 3- (meth) acryloyloxypropyltrimethoxysilane and 3- (meth) acryloyloxypropyltriethoxysilane. And so on. Specific examples of the linear or branched unsaturated carboxylic acid amide include diacetone (meth) acrylamide and the like.

From the viewpoint of color development of the ink receiving layer, examples of the monomer having no cyclic structure include methyl methacrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, butyl methacrylate, methacrylic acid, diacetone acrylamide, and 3-methacryloyloxypropyltri. Preference is given to methoxysilane and allyl methacrylate.

In the present specification, (meth) acrylic acid means acrylic acid or methacrylic acid, (meth) acrylate means acrylate or methacrylate, and (meth) acrylamide means acrylamide or methacrylamide. means.

The monomer having a cyclic structure is not particularly limited, and is, for example, an alicyclic group-containing unsaturated hydrocarbon, an aromatic ring-containing unsaturated hydrocarbon, an alicyclic group-containing unsaturated carboxylic acid, and an alicyclic group-containing unsaturated. Carboxylic acid ester, alicyclic group-containing unsaturated carboxylic acid amide, aromatic ring-containing unsaturated carboxylic acid, aromatic ring-containing unsaturated carboxylic acid ester, aromatic ring-containing unsaturated carboxylic acid amide, alicyclic group-containing alkoxysilane, fragrance Examples thereof include ring-containing alkoxysilanes. The alicyclic group and the aromatic ring may have a hetero atom such as a nitrogen atom or an oxygen atom in the ring, or may have a substituent.

The alicyclic group is not particularly limited, and is, for example, an alicyclic hydrocarbon group such as a cycloalkyl group (for example, a cyclohexyl group) or a cycloalkenyl group (for example, a cyclohexenyl group); an alicyclic group such as a piperidyl group. The formula heterocyclic group can be mentioned. The aromatic ring is not particularly limited, and examples thereof include aromatic carbon rings such as benzene ring, naphthalene ring, and anthracene ring; and aromatic heterocycles such as pyridine ring.

Specific examples of the alicyclic group-containing unsaturated hydrocarbon include vinylcyclohexane and the like. Specific examples of the aromatic ring-containing unsaturated hydrocarbon include styrene and the like. Specific examples of the alicyclic group-containing unsaturated carboxylic acid include 3-cyclohexylacrylic acid. Specific examples of the alicyclic group-containing unsaturated carboxylic acid ester include cyclohexyl (meth) acrylate, glycidyl methacrylate, 1,2,2,6,6-pentamethyl-4-piperidyl methacrylate and the like.

Specific examples of the alicyclic group-containing unsaturated carboxylic acid amide include N-cyclohexyl (meth) acrylamide and the like. Specific examples of the aromatic ring-containing unsaturated carboxylic acid include 3-phenyl (meth) acrylic acid. Specific examples of the aromatic ring-containing unsaturated carboxylic acid ester include phenyl (meth) acrylate and the like. Specific examples of the aromatic ring-containing unsaturated carboxylic acid amide include N-phenyl (meth) acrylamide and the like. Specific examples of the alicyclic group-containing alkoxysilane include 3-glycidoxypropyltrimethoxysilane and 3-glycidoxypropyltriethoxysilane.

Specific examples of the aromatic ring-containing alkoxysilane include 3-phenoxypropyltrimethoxysilane and 3-phenoxypropyltriethoxysilane. From the viewpoint of color development of the ink receiving layer, cyclohexylmethacrylate, styrene, glycidylmethacrylate, 3-glycidoxypropyltriethoxysilane, 1,2,2,6,6-pentamethyl-4-piperidylmethacrylate and the like are preferable.

Since an ink receiving layer having excellent color development property can be obtained, the ratio of the structural unit derived from the monomer having a cyclic structure in the above resin is 0 to 28% by mass, preferably 0 to 26% by mass, and more preferably 0 to 25. It is mass%. Further, since the presence of a small amount of the monomer having a cyclic structure can be expected to be effective in adjusting the dot diameter, it is preferably more than 0 and 25% by mass or less.

From the viewpoint of color development of the ink receiving layer, the resin preferably contains at least one structural unit derived from an ethylenically unsaturated monomer having a solubility parameter of 9.50 to 13.0 in an amount of 25 to 85% by mass. It is a polymer. In the present specification, the ethylenically unsaturated monomer means a monomer having a double bond in the molecule and causing a polymerization reaction through addition to the double bond. The ethylenically unsaturated monomer is not particularly limited, and examples thereof include those having a double bond among those exemplified above as a monomer having no cyclic structure and a monomer having a cyclic structure.

The calculated glass transition temperature of the resin is not particularly limited, and is preferably −15 to 85 ° C., more preferably −10 to 50 ° C., and even more preferably −5 to −5 to It is 40 ° C. When the calculated glass transition temperature is −15 ° C. or higher, the sticky feeling is unlikely to remain after drying. When the calculated glass transition temperature is 85 ° C. or lower, drying is unlikely to be delayed. In the present specification, the calculated glass transition temperature means the glass transition temperature calculated by the Fox formula.

The method for producing an aqueous dispersion of resin particles containing the resin has, for example, according to a conventional method, a monomer having no cyclic structure, a monomer having no cyclic structure, and a cyclic structure in an aqueous medium containing water as a main component. It can be produced by subjecting it to a combination with a monomer or the like for emulsion polymerization.

The content of the resin is preferably 10 to 60% by mass, more preferably 20 to 45% by mass, based on the components forming the ink receiving layer. When the content is 10 to 60% by mass, the ink receiving layer and the ink layer or the ink receiving layer and the clear layer are maintained while maintaining the performance that "the monomer does not easily remain after the printing and the color development is excellent". Adhesion with and can be enhanced.

The paint for an ink receiving layer according to the present invention may contain a pigment in addition to the above-mentioned aqueous dispersion. The pigment is not particularly limited, and examples thereof include a coloring pigment (for example, a white pigment), a rust preventive pigment, and an extender pigment generally used in the coating industry.

Specific examples of coloring pigments, rust preventive pigments, and extender pigments include titanium oxide, red iron oxide, yellow iron oxide, carbon black, aluminum tripolyphosphate, zinc phosphate, condensed aluminum phosphate, barium metaborate, calcium carbonate, and sulfuric acid. Inorganic pigments such as barium, kaolin, talc, clay, mica, alumina, myoban, white clay, magnesium hydroxide, and magnesium oxide, phthalocyanine blue, phthalocyanine green, naphthol red, quinacridon red, benzimidazolone yellow, Hansa yellow, benz Examples thereof include organic pigments such as imidazolone orange and dioxazine violet. The pigment may be used alone or in combination of two or more.

The content of the pigment is preferably 35 to 85% by mass, more preferably 40 to 75% by mass, based on the components forming the ink receiving layer. When the content is 35 to 85% by mass, the ink receiving layer and the ink layer or the ink receiving layer and the clear layer are maintained while maintaining the performance that "the monomer does not easily remain after the printing and the color development is excellent". Adhesion with and can be enhanced.

The paint for an ink receiving layer according to the present invention may further contain a film forming aid. From the viewpoint of film forming property, the content of the film forming aid is preferably 0 to 10% by mass with respect to the paint.

In addition to the above-mentioned components, the paint for an ink receiving layer according to the present invention includes additives commonly used in the paint industry, such as photopolymerization initiators, light stabilizers, polymerization inhibitors, organic solvents, and antioxidants. , Silane coupling agent, plasticizer, defoaming agent, surface conditioner, wet dispersant, rhology control agent, ultraviolet absorber, viscosity adjuster, preservative, light stabilizer, etc. within the range that does not impair the object of the present invention. It may be appropriately selected and blended in.

The ink absorption rate of the coating film made of the dried product of the paint for the ink receiving layer according to the present invention is 100% or less, preferably 90% or less, and more preferably 85% or less. When the ink absorption rate is 100% or less, it is easy to reduce the amount of the monomer in the active energy ray-curable ink remaining in the receiving layer in an uncured state, and from the decorated product provided with the receiving layer. It is possible to effectively suppress the generation of odor. In the present specification, the ink absorption rate means an amount measured by the method described in the examples.

Further, the toughness of the coating film tends to be obtained by adjusting the elongation rate of the coating film made of the dried product of the ink receiving layer coating material according to the present invention to 10% or more. On the other hand, when the elongation rate of the coating film is 30% or less, the ink tends to be difficult to penetrate. The elongation rate of the coating film can be adjusted by adjusting the intermolecular crosslink density of the resin described later and the content of the pigment.

In the resin particles in the paint for an ink receiving layer according to the present invention, it is preferable that crosslinks are present between the molecules of the resin. When crosslinks are present between the molecules of the resin, (1) the higher the crosslink density, the more the permeation of the active energy ray-curable ink into the ink receiving layer is suppressed, so that the monomers in the ink are accepted in an uncured state. It is easy to reduce the amount remaining in the layer, it is possible to effectively suppress the generation of odor from the decorated product provided with the receiving layer, and (2) the ink receiving layer for the above-mentioned monomers and solvents can be effectively suppressed. Dissolution resistance is likely to improve.

Cross-linking between molecules of the resin can be performed by using a cross-linking monomer as a raw material monomer for producing the resin, for example, 3-methacryloyloxypropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, glycidylmethacrylate, allyl. It can be introduced by using methacrylate or the like in combination. For example, epoxy groups react with carboxyl groups such as acrylic acid and methacrylic acid. The crosslinkable monomer used for introducing the crosslink between the molecules of the resin may be used alone or in combination of two or more.

In the paint for an ink receiving layer according to the present invention, it is preferable that crosslinks are present between the particles. When crosslinks are present between the particles, the higher the crosslink density, the more the permeation of the active energy ray-curable ink into the ink receiving layer is suppressed, so that the monomers in the ink remain in the receiving layer in an uncured state. It is easy to reduce the amount, and it is possible to effectively suppress the generation of odor from the decorated product provided with the receiving layer. Crosslinking between the particles can be introduced by using a crosslinkable monomer such as diacetoneacrylamide or N- (butoxymethyl) acrylamide in combination as a raw material monomer for producing the resin.

Examples of the cross-linking between particles include those introduced via a cross-linking agent such as a compound having an oxazoline group and adipic acid dihydrazide, and those introduced by self-cross-linking between resins. When a compound having an oxazoline group is used, the carboxyl group in the resin participates in the cross-linking reaction. When adipic acid dihydrazide is used, the carbonyl group in the resin participates in the cross-linking reaction. When N- (butoxymethyl) acrylamide is contained in the raw material monomer, the butoxy group is eliminated by heating to generate a methylol group, and then the resins existing on different particles are self-crosslinked. Each of the cross-linking monomer and the cross-linking agent used for introducing the cross-linking between the particles may be used alone or in combination of two or more.

The active energy ray-curable ink targeted for the ink receiving layer formed from the ink receiving layer paint according to the present invention will be described. The ink contains a coloring pigment. Known materials can be used as the coloring pigment, for example, carbon black, yellow iron oxide, petals, composite oxides (nickel-titanium-based, chromium-titanium-based, bismuth-vanadium-based, cobalt-aluminum-based, cobalt-based. Inorganic pigments such as aluminum / chromium-based, ultramarine blue), titanium oxide, quinacridone-based, diketoprolopeel-based, benzimidazolone-based, isoindolinone-based, anthrapyrimidine-based, phthalocyanine-based, slene-based, dioxazine-based, Examples thereof include organic pigments such as azo. From the viewpoint of weather resistance, it is preferable to use an inorganic pigment.

The content of the coloring pigment in the ink is not particularly limited. The content is preferably 2 to 20% by mass from the viewpoint of color development of the ink.

The ink preferably contains a dispersant. As the dispersant, an anionic dispersant, a cationic dispersant and a nonionic dispersant are preferable. As the dispersant, a commercially available product can be preferably used.

The ink contains an active energy ray-polymerizable monomer. The active energy ray polymerizable monomer is a monomer that undergoes a polymerization reaction by irradiation with an active energy ray such as ultraviolet rays, and has, for example, an acryloyloxy group or a methacryloyloxy group as a functional group exhibiting reactivity when irradiated with an active energy ray. Those are suitable. The polymer obtained after the polymerization of the active energy ray-polymerizable monomer functions as a binder. The active energy ray-polymerizable monomer can be classified into a monofunctional monomer having 1 functional group, a bifunctional monomer having 2 functional groups, and a polyfunctional monomer having 3 or more functional groups according to the number of functional groups. ..

Among the above active energy ray-polymerizable monomers, the monofunctional monomer preferably has a molecular weight of 1000 or less, and specific examples thereof include stearyl acrylate, acryloyl morpholine, tridecyl acrylate, lauryl acrylate, N, N-dimethylacrylamide. , Decyl acrylate, 2-phenoxyethyl acrylate, isodecyl acrylate, isobornyl acrylate, dicyclopentanyl acrylate, dicyclopentenyl acrylate, isooctyl acrylate, octyl acrylate, dicyclopentenyloxyethyl acrylate, cyclohexyl acrylate, N-vinyl Caprolactam, isoamyl acrylate, 2-ethylhexyl-diglycol acrylate, EO (ethylene oxide) modified 2-ethylhexyl acrylate, neopentyl glycol acrylic acid benzoic acid ester, N-vinyl-2-pyrrolidone, N-vinylimidazole, tetrahydrofurfuryl acrylate, Examples thereof include methoxydipropylene glycol acrylate, (2-methyl-2-ethyl-1,3-dioxolan-4-yl) methyl acrylate, cyclic trimethylolpropaneformal acrylate, ethoxy-diethylene glycol acrylate, 4-hydroxybutyl acrylate and the like. .. These monofunctional monomers may be used alone or in combination of two or more.

Among the above-mentioned active energy ray-polymerizable monomers, the bifunctional monomer preferably has a molecular weight of 1000 or less, and specific examples thereof include 1,10-decanediol diacrylate and 2-methyl-1,8-octanediol. Diacrylate, 2-butyl-2-ethyl-1,3-propanediol diacrylate, 1,9-nonanediol diacrylate, 1,8-octanediol diacrylate, 1,7-heptanediol diacrylate, polytetramethylene Glycol diacrylate, 3-methyl-1,5-pentanediol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, neopentyl glycol diacrylate hydroxypivalate, tripropylene glycol diacrylate, 1,4 -Butanediol diacrylate, dipropylene glycol diacrylate and the like can be mentioned. These bifunctional monomers may be used alone or in combination of two or more.

Among the above active energy ray-polymerizable monomers, the trifunctional or higher functional polyfunctional monomer preferably has a molecular weight of 2000 or less, and specific examples thereof include trimethylolpropane triacrylate, ethoxylated trimethylolpropane triacrylate, and propoxy. Trimethylolpropane triacrylate, pentaerythritol triacrylate, ethoxylated glycerin triacrylate, tetramethylolmethane triacrylate, pentaerythritol tetraacrylate, ethoxylated pentaerythritol tetraacrylate, EO-modified diglycerin tetraacrylate, ditrimethylolpropane tetraacrylate, di Examples thereof include pentaerythritol pentaacrylate and dipentaerythritol hexaacrylate. These polyfunctional monomers may be used alone or in combination of two or more.

In the above ink, the content of the active energy ray-polymerizable monomer is preferably 1 to 95% by mass, more preferably 70 to 95% by mass, from the viewpoint of reactivity. Further, from the viewpoint of improving the substrate followability and crack resistance of the ink layer, it is preferable to add a large amount of the monofunctional monomer, and the content of the monofunctional monomer in the ink is 20 to 85% by mass. Is preferable.

Among the active energy ray-polymerizable monomers, acryloylmorpholine, 4-hydroxybutyl acrylate, 2-phenoxyethyl acrylate, isobornyl acrylate, and dicyclopentanyl acrylate, from the viewpoint of improving the scratch resistance of the ink layer. Dicyclopentenyl acrylate, tetrahydrofurfuryl acrylate, methoxydipropylene glycol acrylate, ethoxy-diethylene glycol acrylate, 2-butyl-2-ethyl-1,3-propanediol diacrylate, 1,9-nonanediol diacrylate, 3-methyl -1,5-pentanediol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, tripropylene glycol diacrylate, dipropylene glycol diacrylate, trimethylol propanetriacrylate, ethoxylated trimethylol propanetriacrylate , Propoxylated trimethylol propanetriacrylate, pentaerythritol triacrylate and the like are preferred. From the same viewpoint, the content of the active energy ray-polymerizable monomer having excellent scratch resistance is preferably 0.5 to 60.0% by mass, preferably 5.0 to 60% by mass, based on the total mass of the ink. It is more preferably 0% by mass.

Further, the ink may use an acrylate oligomer. The acrylate oligomer is an oligomer having one or more acryloyloxy groups (CH ₂ = CHCOO−), and the number of functional groups is preferably 2 to 6. The acrylate oligomer preferably has a molecular weight of 2000 to 20000.

The molecular weight is a polystyrene-equivalent weight average molecular weight. Specific examples of the acrylate oligomer include an amino acrylate oligomer [an acrylate oligomer having a plurality of amino groups (-NH ₂ )], a urethane acrylate oligomer [an acrylate oligomer having a plurality of urethane bonds (-NHCOO-)], and an epoxy acrylate oligomer [. An oligomer having a plurality of epoxy acrylates obtained by reacting an epoxy compound with an acrylic acid], a silicone acrylate oligomer [an acrylate oligomer having a plurality of siloxane bonds (-SiO-)], and an ester acrylate oligomer [a plurality of ester bonds (-COO-)]. Acrylate oligomer having] and butadiene acrylate oligomer [acrylate oligomer having a plurality of butadiene units] and the like. The content of the acrylate oligomer in the ink is, for example, 0.4 to 20.0% by mass.

It is preferable to add a photopolymerization initiator, a light stabilizer, a polymerization inhibitor and the like to the ink, and further, in addition to the above-mentioned components, additives commonly used in the ink industry such as water and organic materials. Solvents, antioxidants, silane coupling agents, plasticizers, rust preventives, pH adjusters, defoaming agents, charge control agents, stress relievers, penetrants, surface conditioners, etc. are within the range that does not impair the object of the present invention. It may be appropriately selected and blended within.

In the above ink, the surface tension at the printing temperature is preferably 20 to 35 mN / m, and the viscosity at the printing temperature is preferably 5 to 15 mPa · s. The temperature of the ink at the time of printing is preferably 35 to 50 ° C.

The ink can be prepared by mixing the coloring pigment, the active energy ray-polymerizable monomer, and various components appropriately selected as necessary.

It is preferable to cure the ink layer formed after printing by irradiating it with active energy rays such as ultraviolet light using a metal halide lamp, a high-pressure mercury lamp, an ultraviolet LED, or the like. The wavelength of the active energy ray irradiated to cure the ink layer preferably overlaps with the absorption wavelength of the photopolymerization initiator, and the main wavelength of the active energy ray is preferably 360 to 425 nm.

≪Coating film≫
The coating film according to the present invention comprises a dried product of the paint according to the present invention. The coating material can be dried, for example, by heating at 80 to 120 ° C. for about 1 to 60 minutes. When the paint is dried, not only volatile components such as water evaporate, but also crosslinks may be formed between the particles. Even when crosslinks are formed between the particles, it is simply a dried product of the paint.

≪Laminated body≫
The laminate according to the present invention includes an ink receiving layer made of a coating film according to the present invention and an ink layer made of a cured product of an active energy ray-curable ink, and the ink layer is placed on the ink receiving layer. It is formed. The laminated body may further include a base material, a clear layer, and the like, and more specifically, for example, the base material, the ink receiving layer, the ink layer, and the clear layer are laminated in this order. A laminated body can be mentioned.

The base material is not particularly limited, and is, for example, a wood building material board made of wood such as a single board, a plywood, a particle board, and a medium density fiber board (MDF); a ceramic siding board, a flexible board, and a calcium silicate board. , Gypsum slag bar light board, wood piece cement board, asbestos cement board, pulp cement board, precast concrete board, lightweight bubble concrete (ALC) board, ceramic building material board such as gypsum board; and metal building material board such as aluminum, iron, stainless steel And so on. The surface texture of the base material is not particularly limited, and may have a smooth surface or an uneven shape. Further, the base material may be subjected to a base treatment with a sealer, a primer or the like. The thickness of the base material is not particularly limited, and is, for example, 3 to 30 mm.

The ink receiving layer can be formed, for example, by applying the ink receiving layer coating material according to the present invention onto the substrate and drying it as described above. The coating method is not particularly limited, and examples thereof include air spray coating, airless spray coating, electrostatic coating, roll coater coating, and flow coater coating. The thickness of the ink receiving layer is not particularly limited, and is, for example, 10 to 50 μm.

The ink layer is formed by printing an active energy ray-curable ink on the ink receiving layer by a printing means such as printing with an inkjet printer (that is, an inkjet method) and then curing the ink as described above. be able to. The thickness of the ink layer is not particularly limited, and is, for example, 10 to 50 μm.

The clear layer is arranged so as to cover at least the ink layer, mainly for the purpose of protecting the surface of the ink layer. The clear layer can be formed, for example, by applying a coating composition for a clear layer to the surface of an ink layer and, in some cases, an exposed ink receiving layer, and then forming a film by drying or the like. As a coating method for the clear layer coating composition, a conventionally known coating method can be used without particular limitation. Specifically, air spray coating, airless spray coating, electrostatic coating, roll coater coating, and flow coater can be used. Painting and the like can be mentioned.

≪Active energy ray curable ink and paint / ink set≫
The active energy ray-curable ink according to the present invention is used together with the paint according to the present invention or with the coating film according to the present invention. Further, the paint / ink set according to the present invention includes the paint according to the present invention and the active energy ray-curable ink. The active energy ray-curable ink is not particularly limited, and examples thereof include the active energy ray-curable ink exemplified when the paint for the ink receiving layer according to the present invention is described above.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples. In the examples, "parts" and "%" mean parts by mass and% by mass, respectively, unless otherwise specified.

(Synthesis Example 1)
386 parts of ion-exchanged water and polyoxyethylene-1- (allyloxymethyl) alkyl ether sulfate ammonium salt (first) in a five-necked flask equipped with a stirrer, a reflux cooling tube, a thermometer, a dropping device, and a nitrogen introduction tube. 10 parts of Aqualon KH10) manufactured by Kogyo Seiyaku Co., Ltd. was charged, and the temperature was raised to 80 ° C. while replacing the inside of the reactor with nitrogen. After that, 4 parts of ammonium persulfate was added to the reactor, and then 3 parts of methyl methacrylate, 348 parts of 2-ethylhexyl acrylate, 39 parts of methacrylic acid, and 579 parts of ion-exchanged water, which had been stirred and mixed in a separate container in advance, were added. .Continuous dropping over 5 hours. Then, it was aged at 80 ° C. for 5 hours while continuing stirring, and then cooled to room temperature. Then, it was neutralized to pH 9 with a 28 mass% aqueous ammonia solution to obtain a resin particle aqueous dispersion 1.

(Synthesis Examples 2 to 16)
Similar to Synthesis Example 1, synthesis was carried out with the monomer compositions shown in Tables 1 and 2 to obtain aqueous resin particle dispersions 2 to 16. In the present invention, the calculated Tg is a theoretically calculated value obtained by the following FOX formula.
1 / Tg = W1 / Tg1 + W2 / Tg2 + ... + Wn / Tgn
In the formula, Tg is the calculated Tg (° K), W1, W2, ..., Wn is the mass fraction of each monomer, and Tg1, Tg2, ..., Tgn are homopolymers of each monomer. The glass transition temperature (° K) of the polymer.

* For the silane coupling agent, only the SP value of the organic group is shown.
CHMA; cyclohexylmethacrylate / ST; styrene / GMA; glycidylmethacrylate / KBM403; 3-glycidoxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd.)
LA82; 1,2,2,6,6-pentamethyl-4-piperidyl methacrylate (manufactured by ADEKA)
MMA; Methyl Methacrylate, EA; Ethyl Acrylate, BA; Butyl Acrylate, EHA; 2-Ethylhexyl Acrylate, BMA; Butyl Methacrylate, MAA; Methacrylic Acid, DAAM; Diacetone Acrylamide, KBM503; 3-Methoxyloyloxypropyltrimethoxysilane ( Shinetsu Chemical Co., Ltd.)
・ AMA; Allyl methacrylate

(Example of preparation of paint for ink receiving layer)
(Examples 1 to 36, Comparative Examples 1 to 12)
According to the formulations shown in Tables 3 to 8, the raw materials and titania beads were mixed and then dispersed by a bead mill. After the dispersion, the titania beads were removed to prepare a paint for an ink receiving layer.

1) Titanium oxide, density 3.8 g / cm ³ , (TITONE R-62N, manufactured by Sakai Chemical Industry Co., Ltd.)
2) Heavy calcium carbonate, density 2.7 g / cm ³ , average particle diameter 2 μm (made by Maruo Calcium)
3) SN Deformer 1316 (manufactured by San Nopco Ltd.)
4) ASE-60 (manufactured by Rohm and Hearth)
5) Proxel AM (manufactured by Arch Chemicals)
6) TINUVIN 1130 (manufactured by BASF)
7) Sanol LS-292 (manufactured by Sankyo Kasei Co., Ltd.)

<Preparation example of active energy ray-curable ink>
According to the formulation shown in Table 9, the raw material and zirconia beads (φ0.5 mm) were mixed and then dispersed by a bead mill. After the dispersion, the zirconia beads were removed to prepare a black UV ink (hereinafter, also referred to as UV ink).

8) MA100 (carbon black pigment, product name manufactured by Mitsubishi Chemical Corporation)
9) DISPERBYK-2155 (manufactured by BYK)
10) BYK-UV3500 (manufactured by BYK)

The surface tension of the active energy ray-curable ink was measured at a temperature of 45 ° C. using a surface tension meter (CBVP-Z manufactured by Kyowa Surface Chemistry). The viscosity of the active energy ray-curable ink was measured at a temperature of 45 ° C. and a shear rate of 10 s ^-1 using a leometer (MCR301 manufactured by AntonioPysica).

<Preparation example of paint composition for clear layer (hereinafter referred to as "clear paint")>
The raw materials were mixed according to the formulation shown in Table 10 to prepare a clear paint.

11) Acrylic silicone resin emulsion; Polydulex G613, manufactured by Asahi Kasei Corporation

<Manufacturing example of building board (decorative test board)>
1. 1. A water-based sealer (manufactured by Dai Nippon Toryo Co., Ltd., product name: water-based mighty sealer multi) is applied to the surface of the base material slate plate (150 mm x 70 mm x 5 mm, manufactured by TP Giken Co., Ltd.) with an air spray so that the coating amount is 100 g / m ² . Then, the substrate was prepared by drying at room temperature for 2 hours.
2. 2. Ink receiving layer With the coated base material heated to 60 ° C, the above-mentioned ink receiving layer paint is applied to the coated surface of the base material with a coating amount of 120 g / m ² (equivalent to a dry film thickness of 30 μm). I painted it with an airless spray. Then, it was dried at 100 degreeC for 3 minutes to form an ink receiving layer. The substrate temperature was measured using an infrared radiation type non-contact thermometer (ISK-8700II, manufactured by AS ONE Corporation).
3. 3. Ink layer After the ink receiving layer is prepared, the gradation pattern (recording density is from 10%) of the UV ink (black) prepared above using an inkjet printer with the substrate temperature adjusted to 50 to 60 ° C. A solid image) recorded stepwise up to 100% in 20% increments) was formed. At this time, the temperature of the ink at the time of ejecting the ink was 45 ° C. After the pattern was formed, the ink was cured by irradiating with an ultraviolet ray having a peak illuminance of 800 mW / cm ² and an integrated light amount of 300 mJ / cm ² by a metal halide lamp. The substrate temperature was measured using an infrared radiation type non-contact thermometer (ISK-8700II, manufactured by AS ONE Corporation).
4. Clear layer After the ink was cured, the above-mentioned clear paint was applied so that the coating amount was 80 g / m ² (equivalent to a dry film thickness of 25 μm) in a state where the surface temperature of the cured coating film was adjusted to 50 ° C. .. After painting, it was dried at 80 ° C. for 20 minutes to form a clear layer. The surface temperature was measured using an infrared radiation type non-contact thermometer (ISK-8700II, manufactured by AS ONE Corporation).

[Evaluation methods]
The ink absorption rate, print evaluation (color development, dot diameter), adhesiveness, water resistance, and weather resistance of the ink receiving layer were evaluated by the following methods. The measurement results are shown in Tables 11 to 13. Unless otherwise specified, the evaluation was performed in an atmosphere of 23 ° C. and 50% RH.
(1) Color development The color development was evaluated by observing the gradation pattern one day after the preparation of the decorative test plate with the naked eye and a microscope. The evaluation criteria are as follows.
〇: The original color of the ink is printed evenly and evenly, and there is no bleeding.
X: The gradation pattern has unevenness, rubbing, and / or bleeding.

(2) Dot diameter With respect to the gradation pattern one day after the decorative test plate was manufactured, the diameters of dots at arbitrary five points were measured with a microscope, and the average value was obtained.

(3) Adhesiveness (based on JIS K5600-5-6: 1999)
A cutter knife was used to make cuts in the prepared building board at intervals of 2 mm in length and width, 100 squares were prepared, and a cellophane tape (registered trademark) peeling test was performed. The evaluation criteria are as follows.
◯: Classification 0 to 1
Δ: Classification 2
×: Classification 3 to 5
The categories 0 to 5 described in 8.3 of JIS K 5600-5-6: 1999 are as follows.
-Category 0: The edges of the cut are completely smooth and there is no peeling in the eyes of any grid.
-Category 1: The residual ratio of the laminated coating film is 95 to 99%.
-Category 2: The residual rate of the laminated coating film is 85% or more and less than 95%.
-Category 3: The residual rate of the laminated coating film is 65% or more and less than 85%.
-Category 4: Residual rate of laminated coating film is 0%% or more and less than 65%.
-Category 5: Any degree of peeling that cannot be classified even in Category 4.

(4) Water resistance (based on JIS K 5600-6-2: 1999)
The prepared building board was immersed in a constant temperature water tank kept at 40 ° C., and after 240 hours, it was taken out and dried. After that, the appearance such as swelling and whitening that occurred was observed, and the adhesiveness was evaluated by the same method as the method (2) above. The evaluation criteria are as follows.
⊚: There is no appearance abnormality such as swelling and whitening, and the adhesiveness is classified as 0.
◯: There is no appearance abnormality such as swelling and whitening, and the adhesiveness is classification 1. Δ: There is no appearance abnormality such as swelling and whitening, and the adhesiveness is classification 2 to 3.
X: Appearance abnormalities such as swelling and whitening are observed. Adhesion is classified into 4 to 5.

(5) Accelerated weather resistance (based on JIS K 5600-7-7: 2008)
The produced building board was subjected to an accelerated weather resistance test by a weatherometer Ci4000 (manufactured by Atlas) according to the xenon lamp method described in JIS K 5600-7-7. The test time was up to 1000 hours, the appearance of the coating film was visually evaluated, and the adhesiveness was evaluated by the same method as the method (2) above. The evaluation criteria are as follows.
〇: There is no appearance abnormality such as swelling, chalking, and cracks, and the adhesiveness is classified as 0 to 1.
Δ: There is no appearance abnormality such as swelling, chalking, and cracks, and the adhesiveness is classified into 2 to 3.
X: Appearance abnormalities such as swelling, chalking, and cracks are observed. Adhesion is classified into 4 to 5.

(6) Ink Absorption Rate Measurement Method The ink receiving layer paint was applied to a hard vinyl chloride plate preheated to 60 ° C. using a 20 mil applicator and dried at 100 ° C. for 3 minutes (leeward). The dry film was peeled off, cut into a length of 50 mm and a width of 50 mm, and the mass was measured. In a 200 ml glass container, 100 g of UV ink (black) was put, and further, the cut dry film was put. After soaking at 50 ° C for 24 hours, the membrane is taken out, placed on a Kim towel (Crecia Co., Ltd.), and further, a Kim towel is placed on the above membrane placed on the Kim towel to sandwich the membrane, and a weight of 500 g is applied to the surface of the membrane. The UV ink was removed and the mass of the dry film was measured. The ink absorption rate was calculated by the following formula from the mass change before and after immersion of the dry film.
Calculation formula
{(Mass after immersion-Mass before immersion) / Mass before immersion} x 100 = Ink absorption rate (%)

(7) Elongation rate of coating film The paint for the ink receiving layer was applied to a polypropylene plate using a 20 mil applicator and dried at 23 ° C. for 24 hours. Then, it was dried at 80 ° C. for 3 hours and then dried at 120 ° C. for 30 minutes. Then, the obtained dry film was peeled off and cut into a length of 70 mm and a width of 5 mm to obtain a test piece.
The test piece was subjected to a tensile test at a speed of 5 mm / min using an Autograph AG-100KN I type manufactured by Shimadzu Corporation at 23 ° C. and 50% RH, and the elongation rate of the coating film was calculated by the following formula. .. Here, the length of the test piece in the tensile test was set to 50 mm.
{(Test piece length at break in tensile test-Test piece length before test) / (Test piece length before test)} × 100 = Elongation rate of coating film (%)

<Evaluation result>

*: Indicates that the dry film obtained from the paint for the ink receiving layer is completely dissolved in the UV ink (black).

As described above, the present invention is excellent in ink absorption rate, print evaluation (color development property, dot diameter), adhesiveness, water resistance, and weather resistance of the ink receiving layer.

Claims (10)

A paint for an ink receiving layer for an active energy ray-curable ink, wherein the paint contains an aqueous dispersion of resin particles containing a resin, and the ratio of structural units derived from a monomer having a cyclic structure in the resin is A paint that is 0 to 28% by mass and does not contain colloidal silica . The coating material according to claim 1, wherein the resin is a polymer containing 25 to 85% by mass of at least one structural unit derived from an ethylenically unsaturated monomer having a solubility parameter of 9.50 to 13.0. A paint for an ink receiving layer for an active energy ray-curable ink, the paint contains an aqueous dispersion of resin particles containing a resin, and the ink absorption rate of a coating film made of a dried product of the paint is 100%. The paint that is below.
However, the ink for which the ink absorption rate is measured has the following composition.
-Black pigment; 4.0 parts by mass of carbon black-Polymer compound: 40.0 parts by mass of 2-phenoxyethyl acrylate, 40.0 parts by mass of isobornyl acrylate, 10.0 parts by mass of pentaerythritol triacrylate-Polymerization initiator : 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide 5.0 parts by mass ・ Dispersant: 0.5 parts by mass ・ Surface conditioner: 0.5 parts by mass The paint according to claim 1 or 2, wherein the ink absorption rate of the coating film made of a dried product of the paint is 100% or less.
However, the ink for which the ink absorption rate is measured has the following composition.
-Black pigment; 4.0 parts by mass of carbon black-Polymer compound: 40.0 parts by mass of 2-phenoxyethyl acrylate, 40.0 parts by mass of isobornyl acrylate, 10.0 parts by mass of pentaerythritol triacrylate-Polymerization initiator : 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide 5.0 parts by mass ・ Dispersant: 0.5 parts by mass ・ Surface conditioner: 0.5 parts by mass The coating material according to any one of claims 1 to 4, wherein crosslinks are present between the molecules of the resin in the resin particles. The coating material according to any one of claims 1 to 5, wherein crosslinks are present between the particles. A coating film made of a dried product of the paint according to any one of claims 1 to 6. The coating film according to claim 7, wherein the elongation rate of the coating film is 10 to 30%. A paint for an ink receiving layer for an active energy ray-curable ink, wherein the paint contains an aqueous dispersion of resin particles containing a resin, and the ratio of structural units derived from a monomer having a cyclic structure in the resin is The ink layer comprises an ink receiving layer made of a coating film which is a paint having a content of 0 to 28% by mass and is a dried product of the paint, and an ink layer made of a cured product of an active energy ray-curable ink. A laminate formed on the ink receiving layer. A paint for an ink receiving layer for an active energy ray-curable ink, wherein the paint contains an aqueous dispersion of resin particles containing a resin, and the ratio of structural units derived from a monomer having a cyclic structure in the resin is A paint / ink set containing 0 to 28% by mass of a paint and an active energy ray-curable ink.