JP2006247982A - Flexible decorative sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a flexible decorative sheet excellent in cracking resistance and strength, having flexibility and capable of being subjected to curving processing at the normal temperature without receiving special treatment such as watering or heat processing. <P>SOLUTION: Resin impregnated core paper, which is obtained by impregnating a core base material with a resin solution based on an unsaturated polyester resin, is held between resin impregnated decorative paper and a back sheet impregnated with a slurry, which is prepared by adding a thermoplastic resin and an inorganic filler to a fiber base material, to be laminated to the resin impregnated decorative paper and the back sheet and the obtained laminate is subjected to hot press molding. The compounding ratio of the thermoplastic resin and the inorganic filler is set to 1:3-1:10 as a solid ratio. The impregnation ratio of the slurry is set to 700-2,000% by a calculation method shown by formula: impregnation ratio (%)=ä(weight after impregnation - weight of fiber base material)/weight of fiber base material}×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 as a resin for impregnating 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 due to the phenol resin of the core layer, and crack resistance is inferior.

  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, and the decorative layer is made of resin-impregnated decorative paper, and the core layer is not formed. A decorative board comprising a resin-impregnated core paper impregnated with a saturated polyester resin, and a back surface comprising a back sheet in which a fiber substrate is impregnated with a slurry comprising a thermoplastic resin and a filler.

  The present invention is excellent in crack resistance and strength, has flexibility, and can be used for curved surfaces at room temperature without special treatment such as water hammering or heat processing.

  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 impregnated decorative paper, or diallyl phthalate resin-unsaturated polyester resin mixed resin impregnated decorative paper, etc. A material that is rich in properties 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 kraft paper for a decorative board with a resin solution containing an unsaturated polyester resin as a main component. This is to prevent cracking of the paper layer. The number of the resin-impregnated core paper used is appropriately adjusted according to the desired thickness.

  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 polymerization initiators, 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.

  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 base. 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.

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

Example 1 (when using unsaturated polyester resin impregnated core paper)
Manufacture of decorative layer A plain pattern decorative paper with a basis weight of 100 g / m ² is impregnated with a resin solution containing melamine-formaldehyde resin as a main component so that the impregnation ratio shown in Equation 1 is 100%, dried and then melamine A resin-impregnated decorative paper was obtained.

Production of core layer A kraft paper having a basis weight of 250 g / m ² was impregnated with a resin liquid having the following composition so that the impregnation ratio represented by Equation 1 was 100% and dried to obtain an unsaturated porester resin-impregnated core paper. .

Blending of resin liquid 65 parts by weight of unsaturated polyester resin (phthalic anhydride, isophthalic acid / ethylene glycol, propylene glycol)
Styrene monomer 30 parts by weight Polymerization initiator (benzoyl peroxide) 5 parts by weight Release agent 1 part by weight Organic solvent Appropriate amount Production of back sheet 50 g / m ² of polyester fiber nonwoven fabric and 2-HEA (2-ethylhexyl acrylate) 50 g A slurry in which 90 parts of aluminum hydroxide is blended with 10 parts of acrylic resin having a Tg of −50 ° C. obtained by copolymerizing 10 g of MMA (methyl methacrylate) so that the slurry impregnation ratio shown in Equation 1 is 1600%. A back sheet was obtained by impregnation.

Manufacture of a flexible decorative board In order from the bottom, 1 sheet of back sheet, 2 sheets of unsaturated porester resin impregnated core paper and 1 sheet of melamine resin impregnated decorative paper are laminated, and 130 ° C, 100 kg using a flat plate. The flexible decorative board of Example 1 having a thickness of 1.2 mm was obtained by hot pressing under the conditions of 90 cm / cm ² .

Example 2
In Example 1, it implemented similarly except having used the glass fiber nonwoven fabric instead of the polyester fiber nonwoven fabric, and obtained the flexible decorative board of Example 2 of thickness 1.2mm.

Example 3
The same procedure as in Example 1 was performed except that SBR latex (7901 manufactured by Asahi Kasei Co., Ltd.) having a Tg of −20 ° C. was used instead of the acrylic resin. Got.

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 carried out except that the slurry solid content impregnation rate was 500%, but the adhesion was slightly inferior, and the resulting 1.2 mm thick 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. And the decorative sheet of Comparative Example 5 having a thickness of 1.2 mm was obtained, but the bendability was poor.

  The evaluation results are shown in Table 1.

(Test method)
The test method was as follows.
Bendability: A level at which the surface does not break when it is manually bonded to a semi-circular bent plywood along the prescribed R at room temperature.
Elastic modulus: According to the elastic modulus test method of JIS K 6902 “Thermosetting resin decorative board”.
Formability: A case where no delamination was observed was evaluated as ◯, and a case where delamination was performed with a cutter knife was evaluated as Δ.
Crack resistance: A commercially available chloroprene solvent type adhesive (Aika Ivon RC-ET) was applied to both sides of a 18 mm × 300 × 300 square plywood so that the coating amount was 100 g / m ^2. The flexible decorative board and the decorative sheet of the comparative example were bonded together by a roll press so as to be parallel to the fiber direction of the face single plate. Next, a test piece having a depth of 40 mm at both ends parallel to the fiber direction is used as a test piece, which is left in a thermostatic bath at 80 ° C. for 2 hours, and further left in a thermostatic bath at −20 ° C. for 2 hours. One cycle was repeated 5 times, and the crack length was measured. The result was an average of 8 locations.

FIG. 3 is a structural cross-sectional view of a flexible decorative board of Example 1. The front view which shows a crack resistance test.

Explanation of symbols

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

Claims (4)

A resin-impregnated core paper in which a core base material is impregnated with a resin liquid mainly composed of an unsaturated polyester 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, which is laminated and integrated with each other. The decorative board according to claim 1, wherein a blending ratio of the thermoplastic resin and the inorganic filler is 1: 3 to 1:10 in terms of solid content. The decorative board according to claim 1 or 2, wherein the impregnation ratio of the slurry is 700 to 2000% by a calculation method represented by Formula 1.
4. The decorative board according to claim 1, wherein the thermoplastic resin has a glass transition temperature (Tg) of 0 ° C. or lower.