JP2008044150A - Laminate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laminate in which a paint film is excellent in hardness, flaw resistance, and adhesion and which comprises the paint film having two layers different in gloss and is excellent in designability. <P>SOLUTION: By forming the following paint film comprising two layers of a layer (1) and (2), the laminate with the paint film having excellent hardness, scratch resistance and adherance is obtained. The layer (1) is coated with a coating solution comprising an active energy ray curable resin composition with a melting point before curing of 40°C or below, a thermoplastic organic compound with a glass transition temperature of 60-300°C, and an organic solvent which can dissolve a mixture of the resin composition and the organic compound into a transparent solution. The layer (2) is coated with an active energy ray curable composition having a gloss different from that of the paint film of layer (1) wholly or partially on the paint film of the layer (1) on a substrate. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a laminate in which a two-layer coating film having different glossiness is formed on a substrate surface, and the coating film has excellent hardness, scratch resistance and adhesion.

  The surface of a substrate such as paper, wood, plastic, or metal is coated to protect the surface by imparting various performances such as hardness, scratch resistance, friction resistance, and chemical resistance. .

  As the coating agent, an active energy ray-curable composition is mainly used. This is because the surface is more excellent in scratch resistance and friction resistance than when a thermoplastic resin or a thermosetting resin is used.

  When the active energy ray-curable composition is directly applied to various substrates or pattern layers formed on the substrate, the adhesion between the layers decreases due to volume shrinkage during curing of the active energy ray-curable composition, and adhesion Defects occur.

  In order to solve the problem of the adhesion failure, an intermediate layer called a primer may be provided to improve the adhesion between the layers. As these primers, a thermosetting resin, a thermoplastic resin, or the like is used. However, since these are inferior in physical properties such as hardness, scratch resistance, friction resistance, and chemical resistance, they cannot be used as the outermost layer.

As described in paragraph 10, the thermosetting or electron beam curable anchor agent described in Patent Document 1 is “tack-free by heat drying, completely cured by heat or electron beam”. is there. Since the anchor agent alone is not sufficient in hardness and scratch resistance, a layer (so-called top coat layer) made of an electron beam curable resin containing a matting agent is provided.
On the other hand, the active energy ray-curable composition of the present invention is different in that the active energy ray-curable composition is cured after the active energy ray irradiation but the thermoplastic organic compound is not cured. In the present invention, the thermoplastic organic compound may be cured with a crosslinking agent such as polyisocyanate, and in this case, the curing method is different because it is cured by both thermal and active energy ray curing methods.

Patent Document 2 discloses an active energy ray-curable aqueous resin composition mainly comprising an aqueous emulsion resin as a first protective layer, and an active energy ray-curable aqueous resin composition not containing an aqueous emulsion resin as a second protective layer. A surface-reinforced decorative paper consisting of
The first protective layer is an active energy curable composition, but when it is an aqueous emulsion system, it is considered that there is no hardness that can be used as the outermost layer. Therefore, it is considered that a second protective layer is provided to increase the surface hardness and durability.

As described in paragraph 9, the heat-drying ionizing radiation curable resin for intermediate layer described in Patent Document 3 is an aqueous emulsion having an ionizing radiation reactive double bond, or an electron radiation reactive double bond. A water-soluble or solvent-soluble resin having a Tg of 40 ° C. or higher, preferably 60 ° C. or higher.
Even if the intermediate layer is an active energy ray-curable composition, it is considered that there is no hardness that can be used as the outermost layer because it is an aqueous emulsion system. Therefore, it is considered that a top coat layer is provided to improve the surface hardness.

JP-A-8-281896 Japanese Patent Laid-Open No. 9-290487 JP-A-10-119226

  It is an object of the present invention to provide a laminate having excellent hardness, scratch resistance and adhesion, the laminate comprising two layers of coating films having different glossiness, and having excellent design properties. And It is another object of the present invention to provide a laminate that does not need to be composed of a so-called anchor layer or intermediate layer and a topcoat layer in order to obtain sufficient surface hardness and scratch resistance.

The inventors have provided a laminate comprising the following two layers (a) and (b) on the substrate, whereby the laminate having excellent hardness, scratch resistance and adhesion can be obtained. The present invention has been completed by finding that it can be obtained.
(A) Active energy ray-curable resin composition having a melting point of 40 ° C. or less before curing, a thermoplastic organic compound having a glass transition temperature (Tg) in the range of 60 to 300 ° C., and the active energy ray-curable resin composition The layer which applied the coating liquid which consists of an organic solvent which can melt | dissolve the mixture of a thing and a thermoplastic organic compound in a transparent state.
(B) A layer in which an active energy ray-curable composition having a gloss different from that of the coating film of (A) is applied on the whole or a part of the coating film of (A).

Since the laminate of the present invention has the above-described two-layer structure, it has excellent physical properties such as adhesion between the substrate and the coating film and the interlayer between the coating film, hardness, scratch resistance, friction resistance, and chemical resistance. ing. Moreover, a coating film with high designability can be obtained by utilizing the difference in gloss between the two layers.
Furthermore, it is not necessary to comprise an anchor layer or intermediate layer for improving the adhesion to the substrate and a topcoat layer for increasing the surface hardness. The laminate of the present invention has a sufficient surface hardness even when the substrate is coated only with the coating film (a).

  As an active energy ray-curable resin composition having a melting point of 40 ° C. or lower before curing, a general known method used for liquid inks and paints having fluidity at a temperature of the composition of 40 ° C. or lower. A compound having an ethylenically unsaturated double bond can be used. For example, monomers and oligomers having a (meth) acryloyl group can be mentioned.

  That is, as typical examples of monofunctional monomers, aliphatic monoacrylates such as 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate; cyclohexyl (meth) acrylate, dicyclopentanyl (meth) acrylate , Monoacrylate having an alicyclic structure such as isobornyl (meth) acrylate; benzyl (meth) acrylate, phenyl (meth) acrylate, phenoxyethyl (meth) acrylate, phenoxydiethylene glycol (meth) acrylate, phenoxytetraethylene glycol (meth) Aromatic monoacrylates such as acrylate, nonylphenoxyethyl (meth) acrylate, nonylphenoxytetraethylene glycol (meth) acrylate; Alkyl ether acrylates such as tylene glycol (meth) acrylate, ethoxydiethylene glycol (meth) acrylate, butoxyethyl (meth) acrylate, butoxytriethylene glycol (meth) acrylate, methoxydipropylene glycol (meth) acrylate; 2- (meth) acryloyl Dibasic acid mono (meth) acryloyl such as oxyethyl hydrogen succinate, 2- (meth) acryloyloxyethyl hydrogen hexahydrophthalate, 2- (meth) acryloyloxyethyl hydrogen phthalate, 2- (meth) acryloyloxypropyl hydrogen phthalate Oxyester; mono 2-ethylhexyl ether polyoxyethylene glycol (meth) acrylate, monononylphenyl ester Monoalkyl ether polyoxyalkylene glycol (meth) acrylates such as terpolyoxyethylene glycol (meth) acrylate, mono 2-ethylhexyl ether polyoxypropylene glycol (meth) acrylate, monononylphenyl ether polyoxypropylene glycol (meth) acrylate; Monoacrylates having polyoxyethylene ether bonds such as polyethylene glycol mono (meth) acrylate and polypropylene glycol mono (meth) acrylate; 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, glycerin mono (meth) Acrylate, 2hydroxy-3-butoxypropyl (meth) acrylate, 2hydroxy-3-phenoxypropyl (meth) Mono (meth) acrylates having hydroxyl groups such as acrylate and ε-caprolactone adducts of 2-hydroxyethyl (meth) acrylate; alicyclic ethers (meth) acrylates such as glycidyl (meth) acrylate and tetrahydrofurfuryl (meth) acrylate Nitrogen-containing N, N-dimethylaminoethyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, morpholino (meth) acrylate, N, N-dimethylacrylamide, dimethylaminopropyl acrylate, N-isopropylacrylamide, etc. Polyoxyalkylene phosphate mono (meth) acrylates such as monoacrylate, polyoxyethylene phosphate mono (meth) acrylate, polyoxypropylene phosphate mono (meth) acrylate, etc. It can be mentioned rate, and the like.

  Bifunctional monomers include ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, 1,3-butylene glycol di (meth) acrylate, and 1,4-butylene glycol di (meth) acrylate. , Neopentyl glycol di (meth) acrylate, 1,6-hexane glycol di (meth) acrylate, nonanediol di (meth) acrylate and other alkylene diol acrylates; diethylene glycol di (meth) acrylate, ditriethylene glycol di (meth) acrylate , Polyoxyethylene glycol di (meth) acrylate, didipropylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, polyoxypropylene glycol di (meth) a Relate, neopentyl glycol polyoxyethylene ether di (meth) acrylate, neopentyl glycol polyoxypropylene ether di (meth) acrylate and other glycols such as ethylene oxide (hereinafter EO), propylene oxide (hereinafter PO), tetrahydrofuran (hereinafter THF) Polyalkylene ether glycol di (meth) acrylates obtained by addition polymerization of cyclic ethers such as bisphenol A di (meth) acrylate, and polyalkylene ether glycols obtained by addition polymerization of bisphenol A and cyclic ethers such as EO, PO, and THF Poly (alkyl) obtained by addition polymerization of di (meth) acrylate, di (meth) acrylate of bisphenol A type epoxy compound, and bisphenol S with cyclic ethers such as EO, PO, and THF Ether glycol di (meth) acrylate, neopentyl glycol hydroxypivalate diol diacrylate, neopentyl glycol hydroxypivalate ε-caprolactone diol diacrylate, pentaerythritol distearate di (meth) acrylate, dicyclopentenyl Examples include diacrylate and di (meth) acryloyl isocyanurate.

  The trifunctional monomer includes polyalkylene ether trimethylolpropane tri (meth) acrylate obtained by addition polymerization of cyclic ethers such as trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, EO, PO, and THF. , Trimethylolpropane-2hydroxypropyl ether-tri (meth) acrylate, glycerin trimethylolpropane-2hydroxypropyl ether-tri (meth) acrylate, tris (acryloyloxyethyl) isocyanurate, and the like.

  Polyfunctional acrylates include polyol poly (meth) acrylates such as ditrimethylolpropane tetra (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol monohydroxypenta (meth) acrylate; ditrimethylolpropane, pentaerythritol, di Poly (meth) acrylates of polyalkylene ether polyols obtained by addition-polymerizing cyclic ethers such as EO, PO, and THF to polyols such as pentaerythritol; monoalkyl ether-dipentaerythritol pentaacrylate, dipentaerythritol hexa (meth) acrylate, Examples include caprolactone-modified dipentaerythritol hexa (meth) acrylate.

  Examples of oligomers include bisphenol A type, novolak type, polyhydric alcohol type, polybasic acid type, polybutadiene type epoxy (meth) acrylate, polyester type, polyether type urethane (meth) acrylate, or glycidyl (meth) acrylate. An acrylic resin (meth) acrylate obtained by reacting acrylic acid with a polymerized acrylic resin may be used.

  Examples of other compounds having an ethylenically unsaturated double bond include N-vinylpyrrolidone, N-vinylcarbazole, styrene, 4-methylstyrene, α-methylstyrene, 1,4-divinylbenzene, diallyl phthalate, Examples thereof include maleimide compounds described in JP-A-11-124403 and JP-A-11-124404.

  Examples of thermoplastic organic compounds having a glass transition temperature in the range of 60 to 300 ° C. include commonly known acrylic resins, acrylic alkyd resins, polyester resins, urethane resins and fibers used in inks and paints. One or more kinds selected from the group consisting of elemental resins are mixed.

  Examples of the organic solvent that can dissolve the mixture of the active energy ray-curable resin composition and the thermoplastic organic compound in a transparent state include alcohol solvents such as methanol, ethanol, isopropyl alcohol, and butanol, acetone, methyl ethyl ketone, Ketone solvents such as methyl isobutyl ketone, ester solvents such as ethyl acetate and butyl acetate, ether solvents such as methyl cellosolve and ethyl cellosolve, hydrocarbon solvents such as toluene, hexane and cyclohexane, and organic solvents such as tetrahydrofuran A solvent and a mixed solvent thereof can be used, but in consideration of dissolution of the thermoplastic organic compound, a ketone solvent or an ester solvent is preferable.

  The active energy ray-curable composition having a gloss different from that of the coating film of (A), which is applied to the whole or a part of the coating film of the layer (A), is the same as that of (A). Composition with adjusted gloss by adding inorganic fillers such as silica, alumina, aluminum hydroxide, glass beads, silicone beads, etc., organic fillers such as acrylic resin beads, urethane resin beads, etc. alone or in combination to the composition Or a composition obtained by singly or in combination with the active energy ray-curable composition, or a composition in which the above filler is added to adjust the gloss.

The mixing ratio of the active energy ray-curable resin composition having a melting point before curing of 40 ° C. or less and the thermoplastic organic compound having a glass transition temperature in the range of 60 to 300 ° C. is the active energy ray-curable composition / thermoplastic property. Organic compound = 5/95 to 70/30, preferably 20/80 to 50/50.
If the ratio of the active energy ray-curable composition is small, physical properties such as good scratch resistance cannot be obtained, and conversely, if the ratio of the active energy ray-curable composition is excessive, active energy ray irradiation is not performed. It becomes impossible to apply overcoat.

  When the composition of the layer (a) described in the means for solving the problem is applied to a substrate, the coating film of (a) is dried with heat, air, etc., and the solvent content is evaporated to form a tack-free coating film. . This makes it possible to apply the layer (b) on the layer (a) without having to cure the layer (b) with active energy rays. This is particularly advantageous in the case of coating by a gravure method because it can be applied repeatedly without installing an active energy ray irradiation device for each coating unit. Tack-free means that the surface of the coating film is dry to the extent that no stickiness is felt due to finger touch or the like.

  In order to impart various functions to the coating composition for a decorative sheet of the present invention thus obtained, as long as it does not depart from the object of the present invention, a coloring agent, extender pigment, silicone, Additives such as lubricants, plasticizers, antifoaming agents, antioxidants, UV absorbers, light stabilizers, coupling agents, surfactants, organic solvents and chelating agents, inorganic fillers and organic fillers can be added. .

  The laminate of the present invention is suitably used as a decorative sheet using paper, plastic, cloth, metal or the like as a base material. This decorative sheet is used for articles such as furniture and the surface of architectural interior materials.

  Examples of the method for applying the coating composition of the laminate of the present invention include offset printing, flexographic printing, roll coating, gravure coating, and bar coater.

The active energy ray-curable composition in the present invention is cured by irradiation with ionizing radiation such as an electron beam, ultraviolet rays, or γ rays.
In the case of curing with ultraviolet rays, a known ultraviolet irradiation device equipped with a high-pressure mercury lamp, excimer lamp, metal halide lamp, or the like can be used. The amount of ultraviolet irradiation during curing is preferably 30 to 1000 mJ / cm2. When the irradiation amount is less than 30 mJ / cm 2, curing is not sufficient, and when it exceeds 1000 mJ / cm 2, the coating film may be yellowed or the substrate may be damaged by heat.

  When hardening with an electron beam, a well-known electron beam irradiation apparatus can be used. The amount of electron beam irradiation during curing is preferably 10 to 100 kGy. If the irradiation dose is less than 10 kGy, curing is not sufficient, and if it exceeds 100 kGy, damage to the coating film and the substrate may occur.

  In the case of curing by irradiation with ultraviolet rays, a photo (polymerization) initiator that generates radicals and acids by irradiation with ultraviolet rays is added in an amount of 0.1 to 20 parts per 100 parts by mass of the active energy ray-curable compound. It is preferable to add about part by mass.

  Radical-generating photo (polymerization) initiators include hydrogen abstraction types such as benzyl, benzophenone, Michler's ketone, 2-chlorothioxanthone, 2,4-diethylthioxanthone, benzoin ethyl ether, diethoxyacetophenone, benzylmethyl ketal, hydroxy Examples include photocleavage types such as cyclohexyl phenyl ketone and 2-hydroxy-2-methylphenyl ketone. These can be used alone or in combination.

Next, the present invention will be described more specifically with reference to examples. In the present specification, unless otherwise specified, parts and% are based on mass.
Tables 1 and 2 show the coating composition and evaluation results of Examples and Comparative Examples.

<Description of raw materials in Table 1 and Table 2>
1) Unidic 17-806 ... A polyfunctional aliphatic urethane acrylate manufactured by Dainippon Ink and Chemicals, Inc. Liquid at 25 ° C.
2) Purple light UV1700B: 10-functional aliphatic urethane acrylate manufactured by Nippon Synthetic Chemical Industry Co., Ltd. Liquid at 25 ° C.
3) Aronix M-402: a hexafunctional monomer manufactured by Toa Gosei Co., Ltd. Liquid at 25 ° C.
The above 1) to 3) are active energy ray-curable resin compositions having a melting point of 40 ° C. or lower.
4) Irgacure 184: Photopolymerization initiator manufactured by Ciba Specialty Chemicals Co., Ltd.
5) Irgacure 819: Photopolymerization initiator manufactured by Ciba Specialty Chemicals Co., Ltd.
6) Dianal BR85: acrylic resin manufactured by Mitsubishi Rayon Co., Ltd. (Tg = 105 ° C.).
7) Acrydic A-814: Dainippon Ink & Chemicals, Inc. acrylic resin (Tg = about 90 ° C.).
The above 6) to 7) are thermoplastic organic compounds having a glass transition temperature in the range of 60 to 300 ° C.
8) Death module L-75: polyisocyanate manufactured by Sumitomo Bayer Urethane Co., Ltd.
9) Silicia 350: Silica manufactured by Fuji Silysia Chemical Ltd.

<Original fabric used>
Cardboard: A Rengo CRC.
Easy adhesion PET: A4300 manufactured by Toyobo Co., Ltd. (thickness: 100 μm).

<Sample preparation conditions>
Coating: Each paint was diluted with MEK / ethyl acetate = 50/50, and adjusted to 15 to 20 seconds with Zahn cup # 3.
The first layer was coated on the entire surface of the raw material with a bar coater # 6 and dried at 100 ° C. for about 30 seconds to volatilize the solvent.
The second layer was partially coated on the first layer with a bar coater # 6 and dried at 100 ° C. for about 30 seconds to volatilize the solvent. Thereafter, the entire coating film was cured under the curing conditions described in Tables 1 and 2.
Curing conditions: UV: High pressure mercury lamp 120 W / cm 1 lamp 10 m / min 1 pass irradiation.
When performing thermosetting, it was left to stand at 60 ° C. for 3 days.

<Evaluation method>
Paint appearance: Transparency is evaluated visually.
Gloss: Measured with a gloss meter at an incident angle and a reflection angle of 60 °.
Evaluation of first layer tack: After heat drying at 100 ° C. for about 30 seconds, tack is evaluated by finger touch.
Nail scratch: The surface of the coating is rubbed with a nail and the degree of scratching is evaluated. ○ indicates no scratches, and × indicates many scratches.
MEK rubbing: The surface of the coating film is rubbed with absorbent cotton containing methyl ethyl ketone (MEK), and the number of times until the coating film dissolves and peels is evaluated.

<Discussion>
In the preparation of the laminates of the examples, the first layer was applied and dried with hot air. However, the stickiness of the surface of the coating film disappeared (tack-free), and the second layer could be applied smoothly. .
In addition, although the second layer was dried by UV irradiation after application, the surface of the first layer alone and the portion where the second layer was laminated had excellent hardness in the nail scratch test and MEK rubbing test. And showed chemical resistance.

The laminate of the present invention is suitably used as a decorative sheet using paper, plastic, cloth, metal or the like as a base material. This decorative sheet is used for articles such as furniture and the surface of architectural interior materials.

Claims (2)

A laminate in which the following layers (a) and (b) are provided on a base sheet.
(A) A layer coated with a coating liquid comprising the following (a) to (c).
(A) An active energy ray-curable resin composition having a melting point of 40 ° C. or lower.
(B) A thermoplastic organic compound having a glass transition temperature in the range of 60 to 300 ° C.
(C) An organic solvent capable of dissolving the mixture of (a) and (b) in a transparent state.
(B) A layer on which the active energy ray-curable composition having a gloss different from that of the coating film of (A) is applied on the entire surface or a part of the coating film of the layer of (A). The laminate according to claim 1, wherein the thermoplastic organic compound (b) comprises at least one selected from the group consisting of an acrylic resin, an acrylic alkyd resin, a polyester resin, a urethane resin, and a fiber resin. body.