JPH11138734A - Decorative sheet with recoating properties - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a decorative sheet with recoating properties which has a highly wear-resistant surface resin layer and shows superb adhesive properties with an ultraviolet-curable resin layer to be coated after the resin layer is formed. SOLUTION: The decorative sheet 1 has a decorative paper base sheet 2, a patterned layer 3 and an ionizing radiation-curable resin layer 4 laminated sequentially and is used for use applications in which an ultraviolet-curable coating is applied later. In this decorative sheet 1, the ionizing radiation-curable resin layer 4 contains a spherical particle and at the same time, the average interbridge molecular weight of the resin contained in the resin layer 4 is 200-1000 as the structural features of the decorative sheet 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a decorative sheet having recoating properties which can be used for interior decoration of buildings, surface decoration of fittings, surface decoration of vehicle interiors, etc., and which can be applied to the surface when used. .

[0002]

2. Description of the Related Art A flooring is known in which a flooring is constructed by stacking a veneer having a thickness of about 0.3 mm on a plywood or the like and further coating an ultraviolet-curable resin paint (UV paint) on the surface. is there. However, when natural wood or the like is used as the veneer as the veneer, it takes a lot of time to manufacture and the woodgrain pattern or the like often does not look so beautiful, so the woodgrain pattern is simply provided on the plywood without using the veneer. In recent years, flooring materials on which a decorative sheet is simply pasted have been used.

For example, as the decorative sheet, an abrasion-resistant resin layer formed from a coating composition containing a binder made of a crosslinkable resin and spherical particles having a higher hardness than the crosslinkable resin is formed on the surface of the substrate. What is provided is known (Japanese Unexamined Patent Publication No.
183147). The decorative sheet has excellent abrasion resistance on the surface and is most suitable for applications such as flooring. When forming a flooring material using a decorative sheet, a groove extending from the surface of the decorative sheet to the surface of the floor substrate is provided so as to resemble a state in which the decorative sheet is attached to the floor substrate and then a veneer is attached.

[0004]

The floor material provided with the groove by attaching the decorative sheet to the above-mentioned floor material is formed because water permeates the floor material from the groove when water is applied to the surface. After doing
An ultraviolet-curable paint (UV paint) is applied to the surface of the decorative sheet to form a resin layer for use.

However, the abrasion-resistant resin layer made of the above-mentioned ionizing radiation-curable resin has poor adhesion to the UV paint, and may cause peeling of the UV paint film after curing. It was found that the adhesion (recoating property) in the case was insufficient.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned drawbacks of the prior art, and has a surface resin layer having excellent abrasion resistance, and the resin layer has good adhesion to a UV paint to be applied later. An object of the present invention is to provide a decorative sheet that is favorable and has stable recoating properties.

[0007]

The present invention relates to a base paper for decorative paper,
Pattern layer, ionizing radiation-curable resin layer is sequentially laminated, in a decorative sheet used for the purpose of coating the UV-curable resin paint on the surface later, the ionizing radiation-curable resin layer is a spherical alumina The present invention is intended to provide a recoatable decorative sheet containing the resin and having an average crosslinked molecular weight of 200 to 1,000.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the drawings. As shown in FIG. 1, the decorative sheet 1 of the present invention
Decorative paper base paper 2, a pattern layer 3 provided on the surface of the decorative paper base paper 2, and an ionizing radiation-curable resin layer 4 on the surface side of the pattern layer 3
Are laminated, and the resin of the ionizing radiation-curable resin layer 4 has an average crosslinking molecular weight of 200 to 1,000. The ionizing radiation-curable resin layer 4 is a surface resin layer containing spherical alumina and having excellent wear resistance. The thickness of the ionizing radiation-curable resin layer 4 is not particularly limited, but is preferably 5 to 500 μm, and particularly preferably 10 to 100 μm.

The decorative paper base paper 2 has a basis weight of 50 to 150 g / m.
Examples include fibrous sheets made of about ^two pieces of paper, woven fabric, or nonwoven fabric. Its thickness can be selected from the range of about 50 to 300 μm. Examples of the fibrous material forming the fibrous sheet include organic synthetic or artificial fibers such as cellulose pulp, hemp, cotton, and nylon, and inorganic fibers such as asbestos, glass, quartz, carbon, and potassium titanate. . The fibrous sheet using the cellulose pulp fiber is so-called "paper", and specific examples include high quality paper, kraft paper, and Japanese paper. Further, the base paper for decorative paper is obtained by impregnating the above fibrous sheet etc. with a curable resin,
So-called impregnated paper can also be used.

The picture layer 3 is formed by picture printing, coloring printing, or the like. The pattern layer 3 is specifically a colored (transparent or opaque) pattern or solid printing by adding a pigment, and uses a known printing method such as gravure printing, offset printing, silk screen printing, or transfer printing from a transfer sheet. And ink (or paint). Examples of the pattern of the picture layer 3 include a wood grain pattern, a stone grain pattern, a cloth grain pattern, a leather pattern, a geometric figure, a character, a symbol, and the like. The ink used for the picture layer 3 uses, as a binder, chlorinated polyethylene, chlorinated polyolefin such as chlorinated polypropylene, polyester, polyurethane, acrylic, vinyl acetate, vinyl chloride / vinyl acetate copolymer, cellulose resin, etc.
One type or a mixture of two or more types is used. Further, a pigment or the like may be added thereto. The pattern layer 3 may be provided on the entire surface of the decorative paper base paper 2 or may be provided partially. As shown in FIG. 1, the picture layer 3 may be composed of a solid printing layer 31 provided on the entire surface of the decorative paper base paper 2 and a pattern printing layer 32 provided partially on the surface of the printing layer. Good.

The average cross-linking molecular weight of the resin of the ionizing radiation-curable resin layer 4 can be obtained from the following equation. However, [Equation 1]
In the formula, the total molecular weight is expressed by Σ (the number of moles of each component ×
Molecular weight of each component), and the number of crosslinking points is {[{(the number of functional groups of each component -1) × 2} × the number of moles of each component].

## EQU1 ## Average crosslinking molecular weight = total molecular weight / number of crosslinking points

By setting the average cross-linking molecular weight of the resin of the ionizing radiation-curable resin layer 4 to 200 or more and 1000 or less, it is excellent in abrasion resistance and UV coated later.
The adhesion to the curable resin coating was sufficient, and a surface resin layer having stable recoating properties was obtained. If the average crosslinked molecular weight is out of the above range, sufficient recoatability cannot be obtained.

The ionizing radiation-curable resin of the ionizing radiation-curable resin layer 4 is cured by ionizing radiation by appropriately mixing a prepolymer, oligomer, and / or monomer having a polymerizable unsaturated bond or an epoxy group in a molecule. Possible compositions are used. Here, the ionizing radiation means an electromagnetic wave or a charged particle beam having an energy quantum that can polymerize or crosslink a molecule, and usually means an ultraviolet ray or an electron beam.

The above prepolymers and oligomers include unsaturated polyesters such as condensates of unsaturated dicarboxylic acids and polyhydric alcohols, methacrylates such as polyester methacrylate, polyether methacrylate, polyol methacrylate and melamine methacrylate, polyester acrylates and epoxy acrylates. And acrylates such as urethane acrylate, polyether acrylate, polyol acrylate and melamine acrylate, and cationic polymerization type epoxy compounds.

The urethane acrylate includes, for example, polyether urethane (meth) acrylates obtained by reacting polyether diol and diisocyanate and represented by the following general formula (1).

## STR1 ## ^{_{CH 2 = C (R 1)}} -COOCH 2 CH 2 -O
CONH-X-NHCOO - ^{[- CH (R 2) - (} CH
_{2) n} -O-] _{m -CONH-X-NHCOO-CH} 2
CH ₂ OCOC (R ¹ ) = CH ₂ (wherein R ¹ and R ² are each hydrogen or a methyl group, X is a diisocyanate residue, n is an integer of 1 to 3, m
Is an integer of 6 to 60. )

Examples of the diisocyanate used in the above polyether-based urethane (meth) acrylate include isophorone diisocyanate, dicyclohexylmethane diisocyanate, hexamethylene diisocyanate, diphenylmethane diisocyanate, and tolylene diisocyanate. Examples of the polyether diol include polyoxypropylene glycol, polyoxyethylene glycol, and polyoxytetramethylene glycol having a molecular weight of 500 to 3,000.

Hereinafter, a production example of urethane acrylate will be described. In a glass reaction vessel equipped with a dropping funnel, a thermometer, a reflux condenser, and a stirring rod, 1,000 parts of polytetrameralene glycol having a molecular weight of 1,000 and 444 parts of isophorone diisocyanate were charged and reacted at 120 ° C. for 3 hours. Thereafter, the mixture was cooled to 80 ° C. or lower, 232 parts by weight of 2-hydroxyethyl acrylate was added, and the reaction was carried out at 80 ° C. until the isocyanate group disappeared to obtain a urethane acrylate.

Examples of monomers used for the ionizing radiation-curable resin include styrene monomers such as styrene and α-methylstyrene, methyl acrylate, 2-ethylhexyl acrylate, methoxyethyl acrylate, butoxyethyl acrylate, and acrylic acid. Acrylates such as butyl, methoxybutyl acrylate and phenyl acrylate, methacrylic acid such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, methoxyethyl methacrylate, ethoxymethyl methacrylate, phenyl methacrylate and lauryl methacrylate Esters, 2- (N, N-diethylamino) ethyl acrylate, 2- (N, N-dimethylamino) ethyl memethacrylate, 2- (N, N-dibenzylamino) methyl acrylate, acrylic Acid-2- (N Substituted amino alcohol esters of unsaturated acids such as N-diethylamino) propyl, unsaturated carboxylic acid amides such as acrylamide and methacrylamide, ethylene glycol diacrylate, propylene glycol diacrylate, propylene glycol diacrylate, neopentyl glycol diacrylate ,
Compounds such as 1,6 hexanediol diacrylate and triethylene glycol diacrylate; polyfunctional compounds such as dipropylene glycol diacrylate, ethylene glycol diacrylate, propylene glycol dimethacrylate, and diethylene glycol dimethacrylate; and / or Polythiol compounds having two or more thiol groups, such as trimethylolpropane trithioglycolate, trimethylolpropane trithiopropylate, and pentaerythritol tetrathioglycol.

Usually, one or more of the above compounds are used, if necessary, in a mixture. In order to impart ordinary coating suitability to the ionizing radiation-curable resin, the above-mentioned prepolymer or polythiol is used in combination. It is preferable that the content of the monomer and / or polythiol be not more than 95% by weight.

If the ionizing radiation-curable resin layer is required to have flexibility, the average cross-linking molecular weight is in the range of 200 to 1,000, and the amount of the monomer may be reduced as long as the coating suitability is not impaired. Alternatively, a structure having a relatively low crosslink density is used by using a bifunctional acrylate monomer. Also, when abrasion resistance, heat resistance, solvent resistance, etc. of the cured product are required,
A structure having a high crosslink density can be obtained by increasing the amount of the monomer within a range that does not impair coating aptitude or by using an acrylate monomer having three or more functional groups. In addition, a monofunctional monomer and a trifunctional or higher functional monomer may be mixed to adjust coating aptitude and physical properties of a cured product.

The above-mentioned monofunctional acrylate monomer includes 2-hydroxyacrylate, 2-hexyl acrylate, phenoxyethyl acrylate and the like. Examples of the bifunctional acrylate include ethylene glycol diacrylate and 1,6-hexanediol diacrylate, and examples of the trifunctional or higher acrylate include trimethylolpropane triacrylate, pentaerythritol tri (tetra) acrylate, and dipentaerythritol hexaacrylate. Acrylate and the like.

Further, a non-ionizing radiation curable resin for adjusting physical properties such as flexibility and surface hardness of the cured product can be added to the ionizing radiation curable resin. As the ionizing radiation non-curable resin, thermoplastic resins such as urethane-based, cellulose-based, polyester-based, acrylic-based, butyral-based, polyvinyl chloride, and polyvinyl acetate are used. Particularly, cellulose-based and urethane-based resins are used. Butyral is preferred from the viewpoint of flexibility.

When irradiating ultraviolet rays to cure the ionizing radiation-curable resin having the above composition, acetophenones, benzophenones, Michler benzoyl benzoate, α-aminoxime ester may be used as a photopolymerization initiator. , Tetramethylthiuram monosulfide,
Thioxanthones, aromatic diazonium salts, aromatic sulfonium salts, metallocenes, and photopolymerization accelerators (sensitizers)
N-butylamine, triethylamine, tri-n
-Butylphosphine and the like can be further mixed and used.

The ionizing radiation-curable resin layer 4 is formed by applying a coating composition containing the above-described ionizing radiation-curable resin and spherical alumina or the like to a decorative paper base paper provided with a picture layer and curing the applied composition. In addition to the above components, the coating composition for the ionizing radiation-curable resin layer 4 may include a coloring agent such as a dye or a pigment, and other CaCO 2 as long as the transparency and abrasion resistance of the surface resin layer are not impaired. ₃ , known additives such as fillers such as BaSO ₄ , nylon resin beads and the like, matting agents and extenders, defoaming agents, leveling agents, thixotropy-imparting agents and the like which are usually added to paints and inks. it can.

The coating composition for the ionizing radiation-curable resin layer may contain a solvent having a boiling point of 70 ° C. to 150 ° C. at normal pressure in which a resin component can be dissolved in order to adjust the viscosity.
It can be used in the composition in a range of 30% by weight or less. When the amount of the solvent added is in the range of 30% by weight or less, drying is smooth, and there is no significant decrease in production speed.

As the above-mentioned solvent, those which are usually used for paints, inks and the like can be used. Specific examples thereof include aromatic hydrocarbons such as toluene and xylene, ketones such as acetone, methyl ethyl ketone methyl isobutyl ketone and cyclohexanone. Acetic acid esters such as ethyl acetate, isopropyl acetate and amyl acetate; alcohols such as methyl alcohol, ethyl alcohol and isopropyl alcohol; ethers such as dioxane, tetrahydrofuran and diisopropyl ether; and mixtures of two or more of these.

The following method can be used to form an ionizing radiation-curable resin layer on the surface of decorative paper base paper using the above coating composition. The direct coating method of directly applying the coating composition on the surface of the decorative paper base paper, or after previously forming an ionizing radiation-curable resin layer on the surface of a peelable substrate, transferring the layer to the surface of the decorative paper base paper A transfer coating method is used. If the material of the decorative paper base paper does not penetrate the coating composition, any of the above and any of the above may be used.However, if the material penetrates the coating composition, The above-mentioned transfer coating method is preferably used in order to obtain a uniform substrate and a uniform thickness of the coating film and to form a uniform abrasion resistance by making the intensity of ionizing radiation uniform.

The above direct coating methods include gravure coat, gravure reverse coat, gravure offset coat, spinner coat, roll coat, reverse roll coat, kiss coat, wheeler coat, dip coat, solid coat by silk screen, wire bar coat, flow coat , A comma coat, a pouring coat, a brush coat, a spray coat and the like can be used, and a gravure coat is preferable.

The transfer coating method includes the following (a) to
(D) is a method of forming a coating film on a thin sheet (film) substrate once, crosslinking and curing the coating film, and then coating the coating on the surface of the substrate. A lamination method (a, b) for adhering to a product, a transfer sheet formed by forming a coating film and, if necessary, an adhesive layer on a release support sheet, and crosslinking and curing the coating film, Can be used, such as a transfer method (c) in which only the support sheet is peeled off after bonding to the three-dimensional object. In addition, on a thin sheet substrate,
As a method for forming the resin layer, the same various coating means as in the above direct coating method can be used. (A) JP-B-2-42080, JP-B-4-199
No. 24, etc., simultaneous injection molding transfer method.
Alternatively, an injection molding simultaneous lamination method as disclosed in Japanese Patent Publication No. 50-19132. (B) JP-A-4-288214, JP-A-5-57
No. 786, a vacuum forming simultaneous transfer method.
Alternatively, a vacuum forming simultaneous lamination method as disclosed in JP-B-56-45768. (C) JP-B-59-51900, JP-B-61-5
No. 895, Japanese Patent Publication No. 3-2666, etc., a lapping simultaneous transfer method or a lapping simultaneous lamination method. (D) V-cut simultaneous lamination method disclosed in Japanese Utility Model Publication No. 15-31122 or Japanese Patent Publication No. 56-31122.
V-cut simultaneous transfer method disclosed in JP 7866 and the like.

Further, a method of sequentially performing the following steps (A) to (D) can also be used (described in JP-A-2-26673). (A) A step of applying an uncured liquid ionizing radiation-curable resin composition to a non-absorbable and releasable synthetic resin sheet. (B) a step of laminating so that the application surface of the ionizing radiation-curable resin composition is in contact with a substrate. (C) a step of irradiating the coating film of the ionizing radiation-curable resin composition with ionizing radiation to crosslink and cure. (D) a step of peeling and removing the synthetic resin sheet. In the above step, when a resin diluted with a solvent is used as the ionizing radiation-curable resin, a step of drying the solvent is performed between steps (A) and (B). According to the above method, even when the base material is a highly permeable material such as paper, the resin is reliably prevented from leaking to the back side of the base material, so-called "uneven", and the surface of the base material is reliably prevented. It is possible to easily form an ionizing radiation curable resin layer having good wear resistance.

The spherical alumina added to the ionizing radiation-curable resin layer may be a true sphere or an elliptical sphere obtained by flattening a sphere.
Further, spherical α-alumina having no cutting edge and having a surface surrounded by a smooth spherical surface such as a shape close to a true sphere or an elliptical sphere resin is used. Specifically, "Spherical Alu" under the trade name of Showa Denko KK
mina AS-10, AS-20, AS-30, AS
-40, AS-50 "and the like. These spherical aluminas are prepared by adding a small amount of a mineralizer or a crystallizing agent such as alumina hydrate, halide or boron compound to a pulverized product such as fused alumina or sintered nalumina and heat-treating at a temperature of 1400 ° C. or more. It can be obtained by:

The average particle diameter of the spherical alumina is 5 to 1
00 μm is preferred. If the average particle size is less than 5 μm, the coating may become opaque and the effect of abrasion resistance may not be sufficiently exhibited. If the average particle size exceeds 100 μm, application of the ionizing radiation-curable resin layer may become difficult, and further formation may occur. The resulting resin layer has reduced surface smoothness. More preferably, the average particle size of the spherical alumina is 10 to 50 μm. The content of the spherical alumina in the ionizing radiation-curable resin layer is preferably 5 to 20 parts by weight based on 100 parts by weight of the cured ionizing radiation-curable resin.

When the decorative sheet of the present invention is used, for example, as a flooring floor material, as shown in FIG.
Is applied to the surface of a floor substrate such as plywood 6 and the like, and a UV top coat 7 is applied to the surface to obtain a flooring floor material 5.

The flooring 5 is provided with grooves at predetermined intervals to make it look like a veneer in order to resemble a flooring using veneers. As shown in FIG. 3 (a), after the decorative sheet 1 is first adhered to the surface of the plywood 6, as shown in FIG. 3 (b), grooves 8 are provided at predetermined intervals to reach the plywood. As shown in (c), a UV paint is applied from the surface of the decorative sheet 1 and cured. At this time, the UV paint enters the groove and further covers the entire surface to form the UV top coat 7. The UV top coat 7 protects the surfaces of the decorative paper base paper and the plywood in the portion of the groove 6 where there is no ionizing radiation-curable resin layer, prevents water from entering the inside, and improves water resistance and the like.

[0035]

Example 1 Impregnated paper GF601 manufactured by Kojin Co., Ltd. was used as decorative paper base paper, and a picture ink [HAT ink manufactured by The Inktech Co., Ltd.] was used on one side of the base paper by a gravure printing method. To give a decorative sheet by applying an ionizing radiation-curable resin paint (cross-linked average molecular weight: 800) having the following composition. Paste the obtained decorative sheet on the surface of plywood,
After the grooves were provided, a UV paint having the following composition was applied to the surface and cured, and a UV top coat was provided to obtain a flooring floor material.

[Ionizing radiation curable resin coating composition] ・ 30 parts by weight of urethane acrylate ・ 20 parts by weight of bifunctional acrylate monomer ・ 10 parts by weight of trifunctional acrylate monomer ・ 3 parts by weight of silicone acrylate ・ Spherical alumina (average particle size: 25 μm) 20 parts by weight

[UV coating composition]-29 parts by weight of urethane acrylate prepolymer-6 parts by weight of polyethylene glycol diacrylate-8 parts by weight of ethyl carbitol acrylate-7 parts by weight of 2-ethylhexyl acrylate-Impact resistant resin fine particles (Izod impact value)・ Spherical particles of 70 kgcm / cm) ・ 4 parts by weight of silicone acrylate ・ 2 parts by weight of photopolymerization initiator (methylbenzoinformate) ・ Solvent (isopropyl alcohol)

Comparative Example 1 The cross-linking average molecular weight of the resin in the ionizing radiation-curable resin layer was 18
Except that it was 0, a decorative sheet was obtained in the same manner as in Example 1,
Flooring flooring was obtained from the decorative sheet.

Comparative Example 2 The crosslinked average molecular weight of the resin of the ionizing radiation-curable resin layer was 12
A decorative sheet was obtained in the same manner as in Example 1 except that the value was set to 00, and a flooring floor material was obtained from the decorative sheet.

The results obtained by measuring the recoatability of the flooring materials of Example 1 and Comparative Examples 1 and 2 are shown in Table 1.
In addition, the recoating property was determined by applying a UV-curable urethane paint to the top coat, UV-curing, and performing a cellophage tape adhesion test.

[0041]

[Table 1] * 1 Peeled state between the decorative sheet and the UV top coat

[0042]

As described above, the decorative sheet according to the present invention is characterized in that the ionizing radiation-curable resin layer contains spherical alumina and the average cross-linking molecular weight of the resin is 200 to 1000, so that the surface of the decorative sheet is When coated with UV paint or the like, the adhesiveness to the UV coating film is always good, and it has a reliable recoating property and excellent wear resistance.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing one example of the decorative sheet of the present invention.

FIG. 2 is a longitudinal sectional view showing one example of a flooring flooring using the decorative sheet of the present invention.

FIG. 3 is a process chart for explaining a method of manufacturing the flooring floor material shown in FIG. 2;

[Explanation of symbols]

 Reference Signs List 1 decorative sheet 2 decorative paper base paper 3 picture layer 4 ionizing radiation curable resin layer 5 flooring flooring 6 plywood 7 UV top coat

Claims (1)

[Claims] 1. A decorative sheet used for an application in which a base paper for decorative paper, a pattern layer, and an ionizing radiation-curable resin layer are sequentially laminated, and a surface thereof is coated with an ultraviolet-curable resin paint later. The radiation curable resin layer contains spherical alumina, and the resin has an average crosslinked molecular weight of 200 to 10
A decorative sheet having a recoating property of 00.