JPH07290674A - Matte decorative sheet with scuff resistance - Google Patents

Abstract

PURPOSE:To provide a transparent or translucent matte decorative sheet having high scuff resistance. CONSTITUTION:A transparent or translucent matte decorative sheet having scuff resistance is obtained by coating a base material for a decorative sheet with ionizing radiation curable resin composition containing impact resistant fine particles each having a particle size of 0.1-50mum and critical surface tension of 25dyn/cm or more and emitting ionizing radioactive ray to cure it.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a decorative sheet for building materials, which is provided for the purpose of imparting a design and protecting the surface of furniture, wall surfaces, floor surfaces and the like, and a method for producing the same. More specifically, the present invention relates to a scratch-resistant matte decorative sheet which can be sufficiently used as a horizontal surface decorative material such as a table, a shelf, a frame, and a floor.

[0002]

2. Description of the Related Art As a conventional technique of the present invention, a surface of a decorative sheet having a pattern printed on the surface of a plastic film or the like is coated with an ionizing radiation curable resin composition and irradiated with ionizing radiation such as ultraviolet rays or electron beams. A method of forming a surface protective layer is known. Further, Japanese Examined Patent Publication No. 62-21815 discloses a photocurable composition in which a support is coated with a wear-resistant transparent or translucent film made of a photopolymerizable composition containing an inorganic charge material.

[0003]

As a problem to be solved by the present invention, in the case of a cured coating film containing only the ionizing radiation curable resin composition described in the prior art of the present invention, the hardness of the cured coating film is increased. Although it is possible to increase the cross-linking density, the impact resistance becomes poor, and as a post-process, it can be used for lapping, vacuum lamination, V-cut processing, etc. on decorative base materials for furniture, walls, shelves, floors, etc. There is a defect that cracks or cracks are easily generated on the surface due to bending or the like.

Further, JP-B-62-21815 has abrasion resistance of the coating film surface by incorporating silica or alumina as an inorganic loading material in the photopolymerizable composition in order to improve the coating film hardness. It made it possible. However, in order to obtain the transparency of the coating film,
It is necessary that the size of the particles is 0.001 μm to 0.1 μm, and that the surface of the particles of the inorganic charge material is chemically and organically modified by a graft method.

On the other hand, it is an object of the present invention to provide a decorative sheet which has sufficient scratch resistance and matte design effect, and has sufficient bending workability and flexibility.

The present invention also contains fine particles having a particle diameter of not more than the film thickness and fine particles having a particle diameter of not less than the film thickness to obtain a matting effect due to the unevenness of the coating film surface, while maintaining the transparency of the coating film itself. The present invention provides a decorative sheet that does not impair the above properties, and that the surface of the fine particles is organophilic even if chemical treatment is not performed in a complicated process, and thus enables strong adhesion to the ionizing radiation curable resin.

[0007]

The present invention provides a decorative sheet having a protective layer of an ionizing radiation-curable resin which contains resin particles on a decorative sheet substrate and is cured by irradiation with ionizing radiation. Has a particle size of 0.1 to 50 μm,
It is characterized by having a critical surface tension of 25 dyn / cm or more, projecting on the surface of the protective layer to form fine irregularities, and being covered with the ionizing radiation curable resin so as not to impair the irregularities. A matte decorative sheet having scratch resistance.

The resin fine particles of the present invention having the above structure have a particle size of 0.1 to 50 μm and a critical surface tension of 25 dyn /
Any resin of cm or more may be used. For example, acrylic resin represented by polymethylmethacrylate, polyethylmethacrylate, polyacrylonitrile, polymethacrylonitrile, etc., polycarbonate, polystyrene, polyvinyl chloride, etc. can be used.

The ionizing radiation curable resin of the present invention includes:
A polymer, a prepolymer, or a monomer that causes a cross-linking polymerization reaction by ionizing radiation to be solidified is used. Specifically, a radical polymerization system composed of a compound having a (meth) acryloyl group such as (meth) acrylamide, (meth) acrylonitrile, (meth) acrylic acid, (meth) acrylic acid ester (here, (meth)) Acryloyl means acryloyl or methacryloyl. The same shall apply hereinafter), epoxy, cyclic ether, cyclic acetal, lactone, vinyl monomer, cationic polymerization system comprising a combination of cyclic siloxane and aryldiazonium salt, diaryliodonium salt, thiol group. A compound having a compound such as trimethylolpropane trithioglycolate, trimethylolpropane trithiopropylate, pentaerythritol tetrathioglycol and a polyene / thiol system composed of a polyene compound can be used.
The thickness of the ionizing radiation-curable resin is about 1 to 50 μm, but it is particularly preferably 10 in consideration of scratch resistance and molding processability.
-30 μm is preferable.

Examples of the monofunctional monomer of the radical polymerization type (meth) acrylate compound include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, methoxyethyl (meth) acrylate and methoxybutyl (meth). ) Acrylate, butoxyethyl (meth) acrylate, 2 ethylhexyl (meth) acrylate, N, N-dimethylaminomethyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylate, N, N-diethylaminoethyl (meth) Acrylate, N, N-diethylaminopropyl (meth) acrylate, N, N-dibenzylaminoethyl (meth) acrylate, lauryl (meth) acrylate, isobornyl (meth) acrylate, ethylcarbitol (meth) acr Rate, phenoxyethyl (meth) acrylate, phenoxypolyethylene glycol (meth) acrylate, tetrahydroxyfurfuryl (meth) acrylate, methoxytripropylene glycol (meth) acrylate, 2- (meth) acryloyloxyethyl-2-hydroxypropyl phthalate , 2-
(Meth) acryloyloxypropyl hydrogen phthalate,

As the polyfunctional monomer of radical polymerization system, ethylene glycol di (meth) acrylate,
Diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, 1,6-hexyldiol di ( (Meth) acrylate, 1,9-nonanediol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, triprolylene glycol di (meth) acrylate, bisphenol A-di (meth) acrylate
Acrylate, trimethylolpropane tri (meth) acrylate, trimethylolpropane ethylene oxide tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol Hexa (meth) acrylate, glycerin polyethylene oxide tri (meth) acrylate, tris (meth) acryloyloxyethyl phosphate, etc.

Alkyd (meta) as a prepolymer
There are (meth) acrylates such as acrylates, urethane (meth) acrylates, epoxy (meth) acrylates, polyester (meth) acrylates, polybutadiene (meth) acrylates, and unsaturated polyesters.

Among these compounds containing a (meth) acryloyl group, a compound containing an acryloyl group, that is, an acrylate, has a higher polymerization reaction rate. Therefore, when importance is attached to the production rate of coating and forming the ionizing radiation-curable resin layer, acrylate is more preferable than methacrylate.

The above compounds may be used alone or in admixture of two or more. Further, the total sum of (meth) acryloyl groups in the mixed composition is 0.2 to 12 mmol /
g, preferably 2 to 10 mmol / g.

Here, as a photopolymerization initiator in the case of curing by irradiation with ultraviolet rays, benzoin, benzoin methyl ether, acetophenone, benzophenone, Michler's ketone, diphenyl sulfide, dibenzyl disulfide, diethyl oxite, triphenyl biimidazole, isopropyl One or two or more kinds of —N, N-dimethylaminobenzoate and the like can be used by mixing 0.1 to 10 parts by weight with respect to 100 parts by weight of the ionizing radiation curable resin.

Here, ethyl acetate, butyl acetate, as a solvent for dissolving the ionizing radiation-curable resin in the composition containing the ionizing radiation-curable resin to adjust the viscosity and the like to impart coating suitability, One or two or more of esters such as cellosolve acetate, ketones such as acetone, methyl ethyl ketone, ethyl isobutyl ketone, alcohols such as methyl alcohol, ethyl alcohol, isopropyl alcohol, etc. can be used in an arbitrary mixture. .

In the composition containing the ionizing radiation-curable resin, if necessary, other than the above as long as it does not impair the scratch resistance, moldability, matteness and curability of the coating film. You may add the additive of. For example, in order to improve the dispersibility of the impact-resistant resin fine particles, silica, talc, calcium carbonate having a particle size of 1/3 or less of the impact-resistant resin fine particles,
Examples thereof include fine particle dispersion improvers such as barium sulfate and organic bentonite, surfactants for improving the dispersibility of impact-resistant resin fine particles or antistatic coating films, and colorants such as dyes and pigments.

As the base material for the decorative sheet of the present invention, a synthetic resin sheet is most preferable in terms of moldability and coating suitability. For example, polyolefin such as polyethylene and polypropylene, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, ethylene vinyl acetate copolymer, vinyl resin such as ethylene vinyl alcohol copolymer, polyester such as polyethylene terephthalate and polybutylene terephthalate, polystyrene , Acrylic styrene copolymer, A
Styrene resin such as BS resin, polycarbonate, nylon, ionomer resin and the like can be used. Among these, particularly, the thickness is 50 to 300 μm and the number of plasticizer parts is 8 to 30.
Part by weight of semi-rigid polyvinyl chloride or a resin sheet having flexibility and elastic properties equivalent to this is excellent in terms of moldability, impact resistance, and scratch resistance of the entire decorative sheet.

Other substrates include paper such as thin paper and fine paper, and cloth such as woven fabric and non-woven fabric.

On the surface of the base material, for example, wood grain, stone grain,
Prints that express the surface pattern, texture, abstract pattern, etc. of natural leather may be added, and in addition to the recesses that imitate the conduit part of wood grain, recesses that have shapes similar to stones, leather squeezing, textures, etc. May be formed by combining the above-mentioned printed patterns.

As the decorative sheet base material having the concave portion, even if the concave portion is directly formed on the above-mentioned printed surface, or on the printed surface of the thermoplastic synthetic resin sheet on which printing is applied, On the other hand, a laminated sheet obtained by so-called doubling embossing, which is obtained by laminating a separately manufactured thermoplastic synthetic resin sheet by heat bonding and shaping the laminated sheet surface by embossing, is a base material for a decorative sheet. Can be used as

In particular, when the printed pattern layer is provided, abrasion resistance is required, but in order to impart abrasion resistance in addition to scratch resistance, the printed pattern layer is provided between two base material sheets. Sandwich, "Backside sheet base material / Printed pattern layer / Transparent topsheet base material /
It is advisable to use a transparent protective layer ”.

The reason is that abrasion resistance, that is, resistance to scratches, is obtained only by withstanding momentary and localized concentration of stress on the surface, whereas abrasion resistance, that is, long resistance. This is because the resistance to the abrasion of the surface layer due to repeated friction for a period is effectively obtained by the physical thickness of the protective layer. However, if the ionizing radiation-curable resin layer is made too thick (particularly 50 μm or more), the warpage of the decorative sheet due to curing shrinkage and the adverse effects such as deterioration of coating film adhesion due to concentration of shrinkage stress at the coating film / substrate interface will occur. . Therefore, it is optimal to limit the protective layer to a maximum thickness of 50 μm sufficient to provide scratch resistance, and to impart insufficient abrasion resistance with the thickness of the transparent surface sheet substrate.

The wiping treatment for filling the colored coating material into the concave portion on the surface of the base material for the decorative sheet uses, for example, a coating material using a thermoplastic resin, a thermosetting resin, or an ionizing radiation curing type resin as a vehicle. can do. FIG. 1 shows a cross-sectional view of a decorative sheet of the present invention in which a printed pattern and concave portions are formed on the surface of a decorative sheet base material, and then a protective layer is formed on the surface.

The decorative sheet of the present invention is used by being stuck to various materials. For example, non-woven fabric, cloth such as woven fabric, veneer, particle board, wood base material such as wood plywood,
It is applied to ABS plates, plastic plates such as acrylic plates, metal foils such as aluminum foil, metal plates such as aluminum plates and steel plates, ceramic plates such as calcium silicate plates, gypsum plates, and cement plates.

Next, as a method for producing the fine particles of the present invention, a method such as a pulverizing method, a polymerization method, or a solubility difference method is used.

The fine particles are dispersed in the ionizing radiation-curable resin by a dry method such as a jet crusher, a roll mill, or the like.
A wet method such as a ball mill or a sand mill is used.

The ionizing radiation-curable resin composition may be formed on the surface of the decorative sheet by coating, for example. Coating methods include gravure coat, gravure reverse coat, gravure offset coat, roll coat, reverse roll coat, knife coat, wire bar coat, flow coat, comma coat, dip coat, wheeler coat, spinner coat, spray coat, silk screen. , Spray coating, brush coating, etc. are applied.

Printing methods on the decorative sheet substrate include intaglio printing such as gravure and gravure offset, letterpress printing such as letterpress and flexo, lithographic printing such as lithographic offset and dilitho, silk screen printing, electrostatic printing and ink jet printing. Etc. plateless printing is applied.

As the ionizing radiation, visible light, ultraviolet rays,
Electromagnetic waves such as X-rays and electron beams or particle beams are used. Ultraviolet rays or electron beams are mainly used in practice. As the ultraviolet ray source, a light source such as a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a low pressure mercury lamp, a carbon arc, a black light, and a metal halide lamp can be used.

As the electron beam source, various electron beam accelerators such as Cockloft-Walton type, Van de Graft, resonance transformer type, insulating core transformer type, linear type, dynamitron type, high frequency type, etc. are used. 100-1000 Ke
Those which irradiate with electrons having an energy of V, preferably 100 to 30 KeV can be used. Usually, the irradiation dose is about 0.5 to 30 Mrad.

As a method of irradiating ionizing radiation, first, ultraviolet rays are irradiated to cure the ionizing radiation-curable resin layer at least to the extent that the surface is dry to the touch, and after that, it is completely cured by an electron beam. May be. Since the surface curability is poor only by ultraviolet irradiation, the surface curability is improved by irradiation with an electron beam after ultraviolet irradiation.

[0033]

In the decorative sheet of the present invention, the resin fine particles have a particle size of 0.1 to 50 μm and a surface critical surface tension of 25 d.
Since it is yn / cm or more (higher than the surface tension of the ionizing radiation curable resin), it is possible to form fine unevenness on the surface of the protective layer so that the ionizing radiation curable resin does not impair the unevenness. To be covered. Therefore,
Since it is configured as described above, the abrasion resistance due to the impact resistance of the dispersed resin fine particles in the ionizing radiation resin as the protective layer is stronger than the protective layer consisting only of the ionizing radiation curable resin,
Moreover, the formability such as bending is also good. In addition, since the fine particles are resin, there is no need for an organophilic treatment as in the case of the inorganic filler, and the adhesiveness with the ionizing radiation curable resin is strong. Further, the layer in which the resin fine particles are dispersed has a smaller difference in refractive index from the ionizing radiation resin than the inorganic filler and is transparent in itself, so that the protective layer is transparent or semitransparent. Therefore, when the colorant is not added to the protective layer, the printed layer and the color tone on the cosmetic sheet substrate can be clearly seen, and when the colorant is added to the protective layer, the color tone of the added colorant becomes more effective. Can be withdrawn.

[0034]

EXAMPLES Next, examples of the decorative sheet of the present invention will be specifically described.

(Example 1) The surface of a polyvinyl chloride sheet (plasticizer 23 phr, thickness 200 μm) was gravure-printed with three-color ink using a vinyl chloride-vinyl acetate copolymer resin as a vehicle to obtain oak wood grain. A printed layer similar to the pattern was provided to obtain a base material for a decorative sheet. Next, the following ionizing radiation curable resin composition (A) is applied to the surface of the base material for a decorative sheet by a roll coater method, and the solvent is dried to form a coating film having a thickness of 25 μm. By irradiation of ultraviolet rays from two high pressure mercury lamps of 160 W / cm at a line speed of 20 m / min,
A decorative sheet having a transparent ionizing radiation curable resin layer was obtained.

Ionizing radiation curable resin composition (A) Ionizing radiation curable resin Urethane acrylate prepolymer 29 parts by weight Polyethylene glycol diacrylate 6 parts by weight Ethylcarbitol acrylate 8 parts by weight 2-Ethylhexyl acrylate 7 parts by weight Photopolymerization initiator (Methylbenzoyl formate) 2 parts by weight Solvent (isopropyl alcohol, etc.) 44 parts by weight Slip agent Silicon acrylate 0.5 parts by weight Fine particles (particle size distribution 0.1-50 μm, critical surface tension 28.5 dyn / cm polycarbonate resin Fine particles) 4 parts by weight

(Example 2) Instead of the ionizing radiation-curable resin composition (A) of Example 1, the following ionizing radiation-curable resin composition (B) was used. A decorative sheet having the same structure as the corresponding structure was obtained.

Ionizing radiation curable resin composition (B) Ionizing radiation curable resin Urethane acrylate prepolymer 29 parts by weight Polyethylene glycol diacrylate 6 parts by weight Ethylcarbitol acrylate 8 parts by weight 2-Ethylhexyl acrylate 7 parts by weight Photopolymerization initiator (Methyl benzoyl formate) 2 parts by weight Solvent (isopropyl alcohol etc.) 44 parts by weight Slip agent Silicon acrylate 0.5 parts by weight Fine particles (particle size distribution 0.1-50 μm, critical surface tension 39 dyn / cm polymethylmethacrylate resin) Fine particles) 4 parts by weight

(Example 3) Ionizing radiation curable resin compositions (C) obtained by removing the photopolymerization initiator in the ionizing radiation curable resin compositions (A) and (B) of Examples 1 and 2. And (D) are used, respectively, and instead of the irradiation of the ultraviolet rays of Example 1 and Example 2, the irradiation of the electron beam is 175 KeV, 3 Mrad, and the line speed is 30 m / min.
A decorative sheet having the same structure as the corresponding structure of Example 1 in other respects was obtained.

(Comparative Example) Instead of the ionizing radiation-curable resin composition (A) of Example 1, the following ionizing radiation-curable resin composition (X) was used, and other configurations were the same as those of Example 1. A decorative sheet having the same structure as the corresponding one was obtained.

Ionizing radiation curable resin composition (X) Ionizing radiation curable resin Urethane acrylate prepolymer 29 parts by weight Polyethylene glycol diacrylate 6 parts by weight Ethylcarbitol acrylate 8 parts by weight 2-Ethylhexyl acrylate 7 parts by weight Photopolymerization initiator (Methylbenzoyl formate) 2 parts by weight Solvent (isopropyl alcohol, etc.) 44 parts by weight Fine particles (fine particles of Teflon resin having a particle size distribution of 0.1 to 50 μm and a critical surface tension of 18.5 dyn / cm) 4 parts by weight

(Measurement / Evaluation Method) The measurement / evaluation method will be described below.

(1) Scratch test The measurement was carried out according to JIS K6902.

(2) Abrasion resistance The measurement was performed according to JIS K6902. Total load 1
060g

(3) Measurement of Pencil Hardness Measurement was carried out in accordance with JIS K5400, and H or more was evaluated as ◯ and F or less was evaluated as x.

(4) Claw scratch The claw is erected perpendicularly to the sample surface and rubbed ten times strongly.

[0047]

[Table 1]

[0048]

Since the decorative sheet of the present invention is constituted as described above, the protective layer whose scratch resistance is only the ionizing radiation curable resin due to the impact resistance of the dispersed fine particles in the ionizing radiation resin which is the protective layer. It is stronger than the above and has good formability such as bending. In addition, since the fine particles are resin, there is no need for an organophilic treatment as in the case of the inorganic filler, and the adhesiveness with the ionizing radiation curable resin is strong. Further, the layer in which the resin fine particles are dispersed has a smaller difference in refractive index from the ionizing radiation resin than the inorganic filler and is transparent in itself, so that the protective layer is transparent or semitransparent. Therefore, when the colorant is not added to the protective layer, the printed layer and the color tone on the cosmetic sheet substrate can be clearly seen, and when the colorant is added to the protective layer, the color tone of the added colorant becomes more effective. Can be withdrawn.

Claims (1)

[Claims] 1. A decorative sheet having a protective layer of ionizing radiation-curable resin, which contains resin particles on a decorative sheet substrate and is cured by irradiation with ionizing radiation, wherein the particles have a particle size of 0.1 to 0.1. 50 μm, critical surface tension 25 dyn /
cm or more, and has a scratch resistance characterized by being formed on the surface of the protective layer so as to form a fine uneven shape and covered with the ionizing radiation curable resin so as not to impair the uneven shape. Matte decorative sheet.