JP2006247845A - Flexible decorative sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a flexible decorative sheet suppressed in the occurrence of an offensive smell, excellent in cracking resistance and strength, having flexibility and capable of being subjected to bending processing at the normal temperature without requiring special treatment such as watering or heat processing. <P>SOLUTION: Resin impregnated core paper, which is obtained by impregnating a core base material for the decorative sheet with a resin liquid based on a thermosetting resin, is held between resin impregnated decorative paper and a back sheet, which is obtained by impregnating a fiber base material with a slurry composed of a thermoplastic resin and an inorganic filler and drying the impregnated fiber base material before treating the same with a peroxide, to be laminated to both of them and the whole is molded under heating and pressure. Alternatively, the peroxide is added to the slurry. The compounding ratio of the thermoplastic resin and the inorganic filler is 1:3-1:10 as a solid ratio and the impregnation ratio of the slurry is 700-2,000% by a calculation method shown by formula: impregnation ratio (%)=ä(weight after impregnation - weight before impregnation)/weight before impregnation}×100. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a flexible decorative board.

Thermosetting resin decorative boards have been known for a long time and are widely used in housing equipment and interior materials. When curved surfaces such as top boards and counters are required, they are more flexible than ordinary melamine resin decorative boards. Rich decorative panels, so-called post-form decorative panels, are used. This decorative board uses a modified melamine resin imparted with plasticity for impregnation of decorative paper, and the core layer uses resin-impregnated paper obtained by impregnating a kraft paper with a phenol resin.
JP-A-9-123366 JP-A-3-253342

  However, although it is excellent in impact resistance and strength, there is a drawback that flexibility is still insufficient due to the hardness resulting from the phenol resin of the core layer. As a means for solving this drawback, there is a method of softening the core using a thermoplastic resin emulsion, but there is a problem of odor due to residual monomers and odorous substances in the emulsion, which is not preferable in the environment.

  The present invention has been studied in view of such a situation, and is a decorative board composed of a decorative layer, a core layer, and a back layer, wherein the decorative layer is made of resin-impregnated decorative paper, and the core layer is resin-impregnated. It is made of core paper, and the back layer is a flexible decorative board made of a back sheet that is treated with peroxide after the fiber base material is impregnated with a slurry made of a thermoplastic resin and a filler.

  The flexible decorative board of the present invention has excellent strength and flexibility, can be used for curved surfaces at room temperature without special treatment such as water hammering and heat processing, and has no odor.

  Hereinafter, the present invention will be described in detail.

  The decorative layer is coated paper, veneer, amino-formaldehyde resin impregnated decorative paper, diallyl phthalate resin impregnated decorative paper, unsaturated polyester resin resin impregnated decorative paper, or diallyl phthalate resin-unsaturated polyester resin mixed resin impregnated decorative paper, etc. Examples include those that are rich in design and can absorb stress during bending. In particular, an amino-formaldehyde resin-impregnated decorative paper excellent in various physical properties such as stain resistance, water resistance, heat resistance, and abrasion resistance is preferred.

  Amino-formaldehyde resin impregnated decorative paper is obtained by impregnating decorative paper for decorative board with amino-formaldehyde resin. Amino-formaldehyde resins include initial condensates obtained by reacting amino compounds such as melamine, urea, benzoguanamine, and acetoguanamine with formaldehyde, etherification with lower alcohols such as methyl alcohol and butyl alcohol, and paratoluene. Those modified with a reactive modifier that promotes plasticization such as sulfonamide can be applied, and a melamine-formaldehyde resin excellent in light resistance is particularly preferable.

  The resin-impregnated core paper used in the present invention is obtained by impregnating a core base material for a decorative board with a resin liquid containing a thermosetting resin as a main component and drying it. This is to prevent stress from concentrating on the decorative layer and causing cracks to easily break. The number of the resin-impregnated core paper used is appropriately adjusted according to the desired thickness.

  As the thermosetting resin, amino-formaldehyde resin, diallyl phthalate resin, unsaturated polyester resin, phenol resin, or a mixture thereof can be applied. Phenol resins are obtained by reacting phenols and aldehydes at a ratio of 1 to 3 moles of aldehydes with 1 mole of phenolic hydroxyl group under a basic catalyst or an acidic catalyst. Phenol, cresol, xylenol, octylphenol, phenylphenol, bisphenol A, bisphenol S, bisphenol F and the like, and aldehydes include formaldehyde, paraformaldehyde, glyoxal and the like. In addition, those modified with a modifying agent that promotes plasticization such as paratoluene sulfonamide, tung oil, phosphoric esters, glycols, etc. can be applied as necessary, and basic catalysts include alkali metals such as sodium and potassium, And oxides and hydroxides of alkaline earth metals such as magnesium and calcium, amines such as triethylamine and triethanolamine, and ammonia. Examples of acidic catalysts include paratoluenesulfonic acid and hydrochloric acid.

  The unsaturated polyester resin comprises an unsaturated polyester and a polymerizable monomer, and includes an unsaturated dibasic acid and / or an acid anhydride thereof and an acid containing other saturated acid and / or an acid anhydride used as necessary. The component and the polyhydric alcohol may be subjected to a dehydration condensation reaction according to a conventional method at about 160 to 230 ° C., preferably 210 to 230 ° C. in an inert gas atmosphere such as nitrogen or argon. In the resin liquid used for impregnation, generally known curing agents, polymerization inhibitors, fillers, mold release agents, and various stabilizers are blended.

  Examples of unsaturated dibasic acids and acid anhydrides used as raw materials for the synthesis of unsaturated polyesters include maleic acid, fumaric acid, itaconic acid, maleic anhydride, and the like. You may use together. The unsaturated dibasic acid and its acid anhydride are preferably used in an acid component of 50 to 100 mol%, particularly preferably 60 to 100 mol%. Other saturated acids and / or acid anhydrides used as necessary include phthalic anhydride, phthalic acid, isophthalic acid, terephthalic acid, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, hexahydrophthalic acid, tetrahydroanhydride Examples thereof include saturated dibasic acids such as phthalic acid, tetrahydrophthalic acid, adipic acid, and sebacic acid. These may be used alone or in combination of two or more. The blending amount of the saturated acid is 0 to 50 mol%, preferably 0 to 40 mol% in the acid component.

  Polyhydric alcohols include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 1,5-pentadiol, 1, Examples thereof include dihydric alcohols such as 6-hexanediol, triethylene glycol and neopentyl glycol, trihydric alcohols such as glycerin and trimethylolpropane, and tetrahydric alcohols such as pentaerythritol. These may be used alone or in combination of two or more. The blending amount is preferably in the range of 100 to 110 mol with respect to the total acid component 100.

  Examples of the polymerizable monomer used as the crosslinking agent include aromatic polymerizable monomers such as styrene, α-methylstyrene, vinyltoluene, and paramethylstyrene, (meth) acrylic monomers such as methyl (meth) acrylate [ (Meth) acrylate refers to methacrylate and acrylate. same as below. ], Ethyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, tertiary butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, stearyl ( (Meth) acrylates, (meth) acrylic acid alkyl esters such as cyclohexyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, caprolactone-modified hydroxy Examples include hydroxyl group-containing polymerizable monomers such as (meth) acrylate.

  Other dialkyl esters of unsaturated dibasic salts such as dimethyl maleate, dimethyl fumarate, dibutyl maleate, dibutyl fumarate, dimethyl itaconate, dibutyl itaconate, (meth) acrylamide, N-methylol (meth) acrylamide N-butoxymethylacrylamide, 2- (2′-hydroxy-5′-methacryloxyethylphenyl) -2H-benzotriazole, 2,2,6,6-tetramethylpiperidinyl methacrylate, N-methyl- Examples also include nitrogen-containing polymerizable monomers such as 2,2,6,6-tetramethylpiperidinyl methacrylate, acetate esters such as vinyl acetate, and polymerizable cyano compounds such as (meth) acrylonitrile.

Examples of the core substrate for the decorative board include kraft paper, non-woven fabrics and woven fabrics made of inorganic fibers and organic fibers such as glass fibers, rock wool, and carbon fibers. It may be in the range of ˜200 g / m ² . For example, in the case of kraft paper corresponding to a bulk specific gravity of 0.6, one having a weight of 100 g / m ² is preferable.

  The back sheet is obtained by impregnating a fiber base material with a slurry made of a thermoplastic resin such as vinyl acetate resin, SBR, acrylic resin, styrene acrylic resin, an inorganic filler, and the like, and drying it. Among the thermoplastic resins, an acrylic resin or SBR latex having a glass transition temperature of 0 ° C. or less that is excellent in bendability, adhesion, and moldability is preferable. This back sheet is softer than the resin-impregnated core paper, contributes to improvement in bendability, and the bendability tends to be inferior if the order of the resin-impregnated core paper and the back sheet is changed.

Examples of the fiber substrate include nonwoven fabrics and woven fabrics made of inorganic fibers and organic fibers such as glass fibers, rock wool, and carbon fibers, and the basis weight of the fiber substrate is in the range of 50 to 200 g / m ^2. Good. Examples of the organic fiber include fibers made of polyethylene, polypropylene, vinylon, polyvinyl chloride, polyvinylidene chloride, polyacrylonitrile, polyamide, polyester, polyurethane, and the like. Among organic fibers, polyester having excellent tensile strength is preferable.

  The inorganic filler contained in the slurry is for the purpose of stabilizing moldability, improving strength, and flame retardancy, and specifically includes aluminum hydroxide, magnesium hydroxide, calcium carbonate, silica, and the like. A fiber substrate having an average particle size in the range of 0.5 to 200 μm can be impregnated into the fiber substrate, and among them, aluminum hydroxide and magnesium hydroxide are excellent in water resistance and heat resistance.

  The blending ratio of the thermoplastic resin and the inorganic filler in the slurry is preferably in the range of 1: 3 to 1:10 in terms of solid content. If the inorganic filler is reduced, the resin may ooze out during hot pressing.

  The slurry solid content (%) in the fiber substrate is a calculation method represented by Equation 1, and is preferably in the range of 700 to 2000%. If the upper limit is exceeded, the solid content will drop off, making it difficult to handle, and if the lower limit is not reached, delamination will easily occur.

In the present invention, the fiber substrate is impregnated with the slurry and dried, and then the peroxide is impregnated or applied. Examples of the peroxide aqueous solution as the polymerization catalyst include water-soluble peroxides such as hydrogen peroxide, potassium persulfate, and ammonium persulfate, alkyl peroxides such as butyl peroxide, and alkyls such as t-butyl hydroperoxide. A hydroperoxide etc. are mentioned. These peroxides are considered to react with residual monomers and odorous substances contained in the back sheet to reduce odor. These peroxides may be used alone or in combination of two or more. The amount of impregnation or coating amount of the peroxide is 0.5 to 5.0 g / m ² in terms of solid content. If it is less than 0.5 g / m ² , it is not very effective in reducing odor. On the other hand, when added in a large amount, the odor of peroxide is dissipated. Further, the peroxide may be blended in the slurry, and the blending ratio is preferably 0.1 to 2 parts by weight with respect to 100 parts by weight of the slurry. Not very effective. On the other hand, when added in a large amount, the odor of peroxide is released.

  EXAMPLES Hereinafter, although an Example is given and demonstrated in detail, this invention is shown more concretely and is not specifically limited.

Example 1 (impregnated with peroxide)
Manufacture of decorative layer To plain paper decorative paper with a basis weight of 100 g / m ² , melamine initial condensate with a molar ratio of formaldehyde to melamine of 1.5, paratoluenesulfonamide 6 parts, curing agent (Catanit A Nitto Riken Kogyo Co., Ltd.) Impregnated so that the impregnation ratio shown in Equation 1 is 100% and dried by adding 3 parts (made by Co., Ltd.) and 1 part release agent (Separ 328 made by Chukyo Yushi Co., Ltd.) A melamine resin impregnated decorative paper was obtained.

Manufacture of core layer A kraft paper of 185 g / m ² is reacted under sodium hydroxide with a molar ratio of phenol to formaldehyde of 1: 1.15, and the impregnation ratio represented by the number 1 of the resol type phenol resin is 100%. Thus, a phenol resin-impregnated paper was obtained.

Production of Back Sheet 50 g / m ² of polyester fiber nonwoven fabric, 10 g of acrylic resin having a Tg of −50 ° C., copolymerized with 50 g of 2-HEA (2-ethylhexyl acrylate) and 10 g of MMA (methyl methacrylate), The slurry containing 90 parts of aluminum hydroxide was impregnated so that the slurry impregnation ratio shown in Formula 1 was 1600% and dried. Subsequently, 1% ammonium persulfate aqueous solution was used to impregnate the ammonium persulfate coating amount to 2.0 g / m ² and dried to obtain a back sheet.

Production of flexible decorative board In order from the bottom, 1 sheet of back sheet, 2 sheets of phenol resin-impregnated paper, 1 sheet of melamine resin-impregnated decorative paper are laminated, and 130 ° C., 100 kg / cm ² using a flat finish plate. The film was hot-pressed for 90 minutes to obtain a flexible decorative board of Example 1 having a thickness of 1.2 mm.

Example 2 (Peroxide blended in slurry)
Manufacture of a decorative layer A plain paper decorative paper having a basis weight of 100 g / m ² is impregnated with the same resin solution as in Example 1 so that the impregnation ratio shown in Equation 1 is 100%, and dried to be impregnated with melamine resin. I got paper.

Production of Core Layer A 185 g / m ² kraft paper was impregnated with the same phenol resin as in Example 1 so that the impregnation ratio represented by Formula 1 was 100% to obtain a phenol resin-impregnated paper.

Production of Back Sheet 50 g / m ² of polyester fiber nonwoven fabric, 10 g of acrylic resin having a Tg of −50 ° C., copolymerized with 50 g of 2-HEA (2-ethylhexyl acrylate) and 10 g of MMA (methyl methacrylate), A slurry containing 90 parts of aluminum hydroxide and 0.5 part of ammonium persulfate was impregnated so that the slurry impregnation ratio shown in Formula 1 was 1600% and dried to obtain a back sheet. Thereafter, the flexible decorative board of Example 2 was obtained by molding in the same manner as in Example 1.

Comparative example 1 (when there are few inorganic fillers with respect to a resin component)
In Example 1, it carried out similarly except having used the slurry which mix | blended 20 parts of aluminum hydroxide with respect to 10 parts of acrylic resins, However, Acrylic resin flowed out at the time of hot press molding, and the decorative sheet was not obtained.

Comparative example 2 (when there are many inorganic fillers with respect to the resin component)
In Example 1, it carried out similarly except having used the slurry which mix | blended 150 parts of aluminum hydroxide with respect to 10 parts of acrylic resins, but adhesiveness was bad and the decorative sheet was not obtained.

Comparative example 3 (when the impregnation rate of the slurry is less than the lower limit)
In Example 1, the same procedure was performed except that the slurry solid content impregnation rate was 500%, but the adhesion was slightly inferior, and the resulting decorative sheet was delaminated with a cutter knife.

Comparative Example 4 (when the impregnation rate of the slurry exceeds the upper limit)
In Example 1, the same procedure was performed except that the slurry solid content impregnation rate was 2200%. However, the acrylic resin flowed out during hot press molding, and a decorative sheet was not obtained.

Comparative Example 5 (when the Tg of the thermoplastic resin exceeds 0 ° C.)
In Example 1, the same operation was carried out except that an acrylic resin having a Tg of 20 ° C. obtained by copolymerizing 35 g of BA (butyl acrylate), 5 g of 2-HEMA (2-hydroxyethyl methacrylate) and 50 g of MMA (methyl methacrylate) was used. Thus, a decorative sheet of Comparative Example 6 was obtained, but the bendability was poor.

Comparative Example 6 (when the amount of ammonium persulfate applied is less than the lower limit)
In Example 1, it implemented similarly except having applied the application quantity of ammonium persulfate to 0.1 g / m < ² >.

Comparative Example 7 (when the application amount of ammonium persulfate exceeds the upper limit)
In Example 1, it implemented similarly except having applied the application quantity of ammonium persulfate to 8 g / m < ² >.

The evaluation results are shown in Table 1.

(Test method)
The test method was as follows.
Bendability: level elastic modulus that does not cause breakage when manually bonded to a semi-circular bent plywood along the prescribed R at room temperature; according to the elastic modulus test method of JIS K 6902 “Thermosetting resin decorative board” .
Formability: O which does not delaminate, and x which delaminates with a cutter knife.
Odor: The presence or absence of an odor emitted from the back surface after molding of the decorative board was confirmed. (Perception test)

FIG. 3 is a structural cross-sectional view of a flexible decorative board of Example 1.

Explanation of symbols

1 resin-impregnated decorative paper 3 resin-impregnated core paper 5 back sheet 6 flexible decorative board

Claims (6)

A resin-impregnated core paper in which a core base material for a decorative board is impregnated with a resin liquid mainly composed of a thermosetting resin is impregnated with a resin-impregnated decorative paper, and a fiber base material is impregnated with a slurry made of a thermoplastic resin and a filler. A flexible decorative board, characterized in that the back sheet is laminated and integrated with the back sheet, and the back sheet is treated with peroxide after impregnating the slurry. A resin-impregnated core paper in which a core base material is impregnated with a resin liquid mainly composed of a thermosetting resin is impregnated with resin-impregnated decorative paper, and a fiber base material is impregnated with a slurry made of a thermoplastic resin and a filler. A flexible decorative board characterized in that the slurry is laminated and integrated, and a peroxide is contained in the slurry. The flexible decorative board according to claim 1 or 2, wherein a blending ratio of the thermoplastic resin and the inorganic filler is 1: 3 to 1:10 in terms of solid content. 4. The flexible decorative board according to claim 1, 2 or 3, wherein the impregnation ratio of the slurry is 700 to 2000% by a calculation method represented by Formula 1.
The flexible decorative board according to claim 1, 2, 3, or 4, wherein the thermoplastic resin has a glass transition temperature (Tg) of 0 ° C or lower. The flexible decorative board according to claim 1, 2, 3, 4, or 5, wherein the thermoplastic resin is an acrylic resin.