JP6738447B2 - Decorative boards and floor materials - Google Patents

Description

The present invention relates to a decorative board and floor material.

Since before, melamine decorative boards composed of a decorative layer, a core layer, and optionally a front layer and a back layer have abundant color patterns and excellent characteristics such as surface strength and maintainability. It is used for a wide range of purposes from furniture and fixtures in public facilities such as welfare facilities to home furniture.
In recent years, the number of surface layers, decorative layers, and core layers is reduced, and a vinyl chloride resin sheet (PVC) is laminated as a base material, and as shown in Patent Literature 2 (Patent Document 2). There is also demand for flooring applications.
Noboru 2510557 publication JP-A-9-300533 JP, 2013-99939, A

However, a conventional melamine decorative board having a reduced number of surface layers, decorative layers, and core layers has a drawback that warpage is likely to occur and the dimensional stability is poor. Further, the laminated flooring material integrated with PVC as a base material has a problem that the dimensional accuracy is not so good due to the shrinkage of the melamine resin in the surface layer and the decorative layer, and the warpage is large and it is difficult to apply.

The present invention has been conceived in order to solve the drawbacks of the conventional melamine decorative board, and is a decorative board including a core layer, a decorative layer, and a surface layer, wherein the surface layer is a condensation paper with a surface paper. A decorative board comprising a thermosetting resin, the decorative layer containing decorative paper and a radical-polymerizable resin, and the core layer containing a fibrous base material, an inorganic filler, and a binder resin.

According to the present invention, by applying a radical polymerization type thermosetting resin to decorative paper, flexibility can be imparted, warpage and dimensional change can be suppressed, and a fibrous base material can be used as the base material of the core layer. A decorative board having excellent dimensional stability can be obtained and can be used as a surface material for a floor material.

1 is a configuration cross-sectional view of a decorative plate of Example 1. FIG. 16 is a sectional view showing the configuration of a decorative board of Example 15. FIG. The structural cross section of the flooring material of Example 23.

Hereinafter, the present invention will be described in detail.
The surface layer relating to the present invention may be a surface paper for decorative boards (also referred to as overlay paper) as long as it is used for decorative boards, and examples thereof include α-cellulose paper, cloth and non-woven fabric. More preferably, it is preferable to use α-cellulose paper which becomes transparent or translucent after the condensation type thermosetting resin is cured. In addition, the wear resistance of the decorative sheet is improved by using the wear resistant surface paper in which the wear resistant powder is mixed. Examples of the wear resistant powder include inorganic powders such as aluminum oxide, silicon carbide and silicon oxide. These abrasion resistant materials are mixed in an amount of 1 to 40% by weight, more preferably 5 to 30% by weight with respect to α-cellulose paper. The basis weight may be 10 to 60 g/m ² .
Within this range, cutting is not performed during impregnation, and the sharpness of the decorative layer described below does not deteriorate.

The surface paper or the abrasion-resistant surface paper is impregnated with a resin liquid containing a condensation type thermosetting resin as a main component and dried. Examples of condensation-type thermosetting resins include initial condensation products obtained by reacting formaldehyde with amino compounds such as melamine, urea, benzoguanamine, and acetoguanamine, etherification with lower alcohols such as methyl alcohol and ethyl alcohol, and paratoluene sulfone. Those modified with a reactive modifier that promotes plasticization such as amide can be applied. In particular, the melamine-formaldehyde resin is excellent in heat resistance and abrasion resistance, and thus can be preferably used. Further, the above abrasion resistant material may be mixed with a resin liquid containing a condensation type thermosetting resin as a main component. The impregnation rate may be 150 to 350% according to the calculation method shown in Formula 1. Within this range, stickiness of the resin-impregnated surface paper is suppressed, and exudation during thermocompression molding is suppressed.

The resin-impregnated decorative paper is a decorative paper for decorative boards having a basis weight of 60 to 200 g/m ² and having various patterns by coloring or printing, and a resin liquid containing a radical polymerization type thermosetting resin as a main component. The radical-polymerizable thermosetting resin may be an unsaturated polyester resin, a vinyl ester resin, a diallyl phthalate resin or a mixture thereof. Particularly, the unsaturated polyester resin and the vinyl ester resin are decorative boards. When it is impregnated so that the curing shrinkage due to a different environment is suppressed and the impregnation rate shown in Formula 1 is 10 to 150%, warpage and dimensional change can be suppressed.

Regarding the unsaturated polyester resin, one or more dihydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1,3-butylene glycol and neopentyl glycol, maleic acid, maleic anhydride, fumaric acid, One or more dibasic acids such as isophthalic acid, terephthalic acid, phthalic acid, phthalic anhydride, and adipic acid are appropriately selected and unsaturated polyester reacted by esterification is reacted with styrene, orthochlorostyrene, diallylphthalate, and methyl. Those to which a polymerizable monomer such as methacrylate is added can be applied. When curing, an organic peroxide such as benzoyl peroxide, methyl ethyl ketone peroxide, cyclohexanone peroxide, acetylacetone peroxide, and acetoacetic acid peroxide, and a curing accelerator such as cobalt complex salt are added as a curing agent.

The vinyl ester resin is obtained by reacting an epoxy resin with an unsaturated monobasic acid using an esterification catalyst. Examples of the epoxy resin include bisphenol A-based epoxy resin, halogenated bisphenol A-based epoxy resin, diglycidyl ether of an adduct of bisphenol A and alkylene oxide such as ethylene oxide or propylene oxide, bisphenol F-based epoxy resin, novolac-based epoxy resin. , And cresol novolac epoxy resin and the like.

Further, examples of the unsaturated monobasic acid include acrylic acid, methacrylic acid, crotonic acid, monomethylmalate, monopropylmalate, sorbic acid or mono(2-ethylhexyl)malate, which is used in combination with the unsaturated monobasic acid. Examples of the polybasic acid to be used include succinic acid, maleic acid, fumaric acid, itaconic acid, phthalic acid, isophthalic acid, terephthalic acid, adipic acid, azelaic acid, 1,12-dodecanedioic acid and dimer acid. .. Examples of the dibasic acid anhydride include maleic anhydride and phthalic anhydride. A modified product using trimellitic anhydride as the tribasic acid anhydride can also be used.

Examples of the esterification catalyst include tertiary amines such as dimethylbenzylamine and tributylamine; quaternary ammonium salts such as trimethylbenzylammonium chloride; inorganic salts such as lithium chloride and chromium chloride; 2-ethyl-4- Imidazole compounds such as methylimidazole; tetramethylphosphonium chloride, diethylphenylpropylphosphonium chloride, triethylphenylphosphonium chloride, benzyltriethylphenylphosphonium chloride, dibenzylethylmethylphosphonium chloride, benzylmethyldiphenylphosphine Examples include phosphonium salts such as phonium chloride and tetraphenylphosphonium bromide; secondary amines; tetrabutylurea; triphenylphosphine; tritolylphosphine; triphenylstibine and the like.

Other methacrylic resins can also be used, and a prepolymer of methyl methacrylate or a solution of polymethyl methacrylate dissolved in a monomer of methyl methacrylate can be applied. The impregnation rate may be 10 to 150% according to the calculation method shown in Formula 1. Within this range, stickiness of the resin-impregnated decorative paper is suppressed, and exudation during thermocompression molding is suppressed.

For the core layer, one or more prepregs obtained by impregnating a fibrous base material with a binder resin and a slurry containing an inorganic filler as essential components and drying the prepreg are used.

Examples of the fibrous base material include organic fiber base materials and inorganic fiber base materials, and examples of the organic fiber base materials include polyethylene, polypropylene, vinylon, polyvinyl chloride, polyvinylidene chloride, polyacrylonitrile, polyamide, and polyester. , Polyurethanes and the like, modified products thereof, fibers made of various copolymers typified by ethylene-vinyl acetate copolymers, mixtures thereof, and composite fibers made of these polymers.

Examples of the inorganic fiber substrate include non-woven fabrics and woven fabrics made of inorganic fibers such as glass fiber, rock wool and carbon fiber, and the basis weight of the inorganic fiber substrate is in the range of 10 to ²⁰⁰ g/m ² . preferable. When the inorganic fiber base material is used, the nonflammability of the decorative board is further improved as compared with the case where the organic fiber base material is used. Among the inorganic fiber substrates, particularly when a glass fiber nonwoven fabric and/or a glass fiber woven fabric is used, heat resistance, flame resistance, and slurry impregnation property are further improved.

As the binder resin, acrylic resin emulsion, amino-formaldehyde resin, and phenol-formaldehyde resin are preferably used. As the acrylic resin emulsion, it is particularly preferable to use an acrylic resin emulsion having a glass transition temperature (Tg) of higher than −20° C. because the adhesiveness and moldability are improved. Among them, it is more preferable to use an acrylic resin emulsion having an average particle diameter of 150 to 300 nm because the binding strength of the core layer and the bending workability and smoothness of the decorative sheet can be further improved. It is speculated that the reason why the smoothness is improved is that the acrylic resin emulsion is fine particles. The average particle diameter is a value calculated using a laser light diffraction/scattering particle diameter measuring device (ELS-8000 manufactured by Otsuka Electronics Co., Ltd.) based on scattered light detected at the time of laser irradiation. If the average particle size is less than the lower limit, gelation tends to occur and smoothness is poor, and if it exceeds the upper limit, the average particle size is too large and smoothness is poor.

The acrylic resin emulsion is obtained by emulsion polymerization or suspension polymerization of (meth)acrylic acid ester as a main monomer in water, and examples of the monomer to be used include (meth)acrylic acid methyl and ethyl, Esters such as propyl, butyl, hydroxyethyl and the like can be mentioned. In addition to these monomers, other copolymerizable monomers or polyfunctional monomers may be copolymerized.

As the amino-formaldehyde resin, in addition to an initial condensate obtained by reacting formaldehyde with an amino compound such as melamine, urea, benzoguanamine, and acetoguanamine, etherification by lower alcohol such as methyl alcohol and ethyl alcohol, para-formation, Those modified with a reactive modifier that promotes plasticization such as toluene sulfonamide can be applied. In particular, melamine-formaldehyde resin can be preferably used because it has excellent heat resistance and abrasion resistance.

The phenol-formaldehyde resin is obtained, for example, by reacting phenols and formaldehyde at a ratio of 1 to 3 mol of aldehydes to 1 mol of phenolic hydroxyl groups under a basic catalyst or an acidic catalyst. It is a thing. Phenols include, for example, phenol, cresol, xylenol, octylphenol, phenylphenol, bisphenol A, bisphenol S, bisphenol F, and the like, and aldehydes include formaldehyde, paraformaldehyde, glyoxal, and the like.

Further, if necessary, a phenol-formaldehyde resin modified with a modifier for promoting plasticization such as urea, urea derivative, paratoluenesulfonamide, tung oil, phosphoric acid esters, glycols can be applied.

Examples of the basic catalyst used for synthesizing the phenol-formaldehyde resin include oxides and hydroxides of alkali metals (such as sodium and potassium) and alkaline earth metals (such as magnesium and calcium), triethylamine and triethanolamine. Examples of the amines, ammonia, etc., and examples of the acidic catalyst include paratoluenesulfonic acid, hydrochloric acid and the like.

The compounding ratio of the binder resin is preferably 3 to 25% by weight based on the total solid content. When the content is 25% by weight or less, the incombustibility is further improved, and the synthetic resin is less likely to exude during the hot press molding. Further, when the content is 3% by weight or more, the adhesion between the resin-impregnated decorative paper and the prepreg and the adhesion between the prepregs are further improved, and the amount of the slurry impregnated into the fibrous base material is more easily controlled.

The amount of the binder resin contained in the core layer (the weight of the binder resin contained in the core layer of a unit area) is 15 to 220 g/m ² . When it is 220 g/m ² or less, the nonflammability of the decorative plate is further improved. Further, when it is 220 g/m ² or less, the binder resin is less likely to exude when the decorative board is manufactured by thermocompression molding. Further, when the amount of the binder resin contained in the core layer is 15 g/m ² or more, when the core layer is manufactured from prepreg, the adhesion between the resin-impregnated decorative paper and the prepreg and the adhesion between the prepregs are further improved. Further, when it is 15 g/m ² or more, when the fibrous base material is impregnated with the slurry to produce the core layer, the impregnated amount of the slurry can be more easily controlled.

Examples of the inorganic filler include endothermic metal hydroxides such as aluminum hydroxide, magnesium hydroxide and calcium hydroxide. In particular, the endothermic metal hydroxide contains water of crystallization, decomposes at high temperature, and releases water. Since the reaction is an endothermic reaction, it has the effect of suppressing the temperature rise during combustion, and improves the nonflammability of the decorative board of the present invention. Among them, aluminum hydroxide is particularly preferably used.

The average particle diameter of the endothermic metal hydroxide can be, for example, in the range of 1 to 50 μm. This average particle diameter is an arithmetic average diameter calculated from the particle size distribution (volume distribution) detected by the laser diffraction/scattering method (microtrack method). When the average particle diameter of the endothermic metal hydroxide is within the above range, the dispersibility of the endothermic metal hydroxide in the slurry is improved, and the impregnability of the slurry into the fibrous base material is improved. .. In addition, the surface of the decorative plate has a smooth finish.

The slurry may further contain an inorganic filler other than the endothermic metal hydroxide. Examples of the inorganic filler other than the endothermic metal hydroxide include carbonates such as calcium carbonate, magnesium carbonate and zinc carbonate, silica, talc and fly ash. The average particle size of the inorganic filler can be, for example, in the range of 0.05 to 20 μm. When the average particle diameter is within this range, the suitability for impregnating the fibrous base material with the slurry is further improved. The average particle diameter of the inorganic filler is an arithmetic average diameter calculated from the particle size distribution (volume distribution) detected by the laser diffraction/scattering method (microtrack method).

Among the inorganic fillers other than the endothermic metal hydroxide, carbonate (for example, calcium carbonate) is particularly preferable. When calcium carbonate is used, workability and machinability in the manufacturing process of the decorative sheet are further improved. As the calcium carbonate, for example, heavy calcium carbonate, light calcium carbonate (precipitable calcium carbonate) or the like can be used. The average particle size of calcium carbonate can be, for example, 0.05 to 10 μm, and more preferably 0.1 to 5 μm. By setting the average particle diameter of calcium carbonate to 0.05 μm or more, aggregation of calcium carbonate in the slurry is less likely to occur, and the suitability for impregnation of the fibrous base material with the slurry is improved. Further, by setting the average particle diameter of calcium carbonate to be 10 μm or less, the surface of the decorative plate becomes smoother and the appearance of the decorative plate is improved.

The light calcium carbonate means calcium carbonate chemically produced by firing limestone, and the heavy calcium carbonate means finely powdered calcium carbonate produced by dry or wet pulverizing white crystalline limestone. ..

The blending ratio of the inorganic filler in the slurry is preferably 20 to 95% by weight. Within this range, the adhesion between the prepregs is good, and when a heat absorbing metal hydroxide is used, the nonflammability of the decorative board can be improved.

The amount of the inorganic filler contained in the core layer (the weight of the inorganic filler contained in the core layer of a unit area) is preferably in the range of 180 to 2000 g/m ² . When it is 180 g/m ² or more and 2000 g/m ² or less, when the core layer is manufactured from prepreg, the adhesion between the prepregs is increased, and when a heat absorbing metal hydroxide is used, the non-combustible performance of the decorative board Can be improved.

When impregnating the fibrous base material with the slurry, the fibrous base material is impregnated to a range of 500 to 1200% and dried by the calculation method shown in Formula 1. When the content is 1200% or less, the slurry solid content is prevented from falling off from the prepreg and the prepreg is easily handled. When it is 500% or more, delamination of the prepreg is less likely to occur.

The decorative board of the present invention is obtained by laminating a core layer, a decorative layer, and a surface layer in order from the bottom, and thermoforming under a condition of a temperature of 125 to 160° C. and a pressure of 20 to 100 kgf/cm ² by a press machine.

Since the decorative board thus obtained has a small dimensional change rate and a small warp, the surface of the floor material based on the thermoplastic resin sheet such as polyolefin resin, polyvinyl chloride resin, urethane resin and various elastomers is used. It can be used as a material. The decorative board and the thermoplastic resin sheet are bonded together using an adhesive. The thermoplastic resin sheet may be non-foamed or foamed, and the expansion ratio is preferably 1.5 to 40 times, and may be either an open-cell foam or a closed-cell foam. If the expansion ratio exceeds the upper limit, the strength of the floor material tends to be poor.

Among the thermoplastic resin sheets, the polyvinyl chloride resin sheet and the foamed polyethylene have cushioning properties, easily absorb the unevenness and irregularities of the base, and are inexpensive and can be suitably used. It is more effective if the thickness is in the range of 1.5 to 5.0 mm . Hereinafter, examples and comparative examples will be described in detail, but the invention is not particularly limited thereto.

(1) An α-cellulosic paper having a production basis weight of the surface layer of 23 g/m ² was impregnated with a resin liquid containing a melamine-formaldehyde resin as a main component so as to be 300% by a calculation method shown in Formula 1. Then, the resin-impregnated surface paper (A) was manufactured by drying.
(2) Manufacturing of decorative layer With a basis weight of 80 g/m ² , a printing liquid in which a wood grain pattern is printed on a decorative paper for a thermosetting resin decorative board is coated with a resin liquid containing a vinyl ester resin as a main component in a number of 1 The resin-impregnated decorative paper (A) was manufactured by impregnating the impregnation rate to 40% by the calculation method defined by the above and drying. The composition of the resin liquid containing a vinyl ester resin as a main component was bisphenol vinyl ester 61-65%, methacrylic monomer 13-17%, propylene glycol monomethyl ether acetate 20% (diluent), and acrylic acid 2%.
(3) Production of slurry (A) (parts by weight are solid content equivalent values)
As the binder, 32 parts by weight of an acrylic resin emulsion having a glass transition temperature (Tg) of 60° C. and an average particle diameter of 200 nm containing 2-ethylhexyl acrylate and methyl methacrylate as main monomers,
As the endothermic metal hydroxide, 300 parts by weight of aluminum hydroxide having an average particle diameter of 8 μm was mixed. Water was added to this mixture to obtain a slurry (A).
(4) Manufacture of prepreg Using the glass fiber nonwoven fabric of 40 g/m ² as the fibrous base material, the slurry (A) manufactured in the above (3) has an impregnation rate of 750 according to the calculation method defined by Formula 1. It was impregnated so that the prepreg became 10%, and dried to produce a prepreg.
(5) Manufacture of decorative board In order from the bottom, four prepregs as a core layer, one resin-impregnated decorative paper (A) as a decorative layer, and one resin-impregnated surface paper (A) as a surface layer are laminated. Then, using a flat-finished plate, thermocompression molding was performed under the conditions of 132° C., 70 kgf/cm ² , and 64 minutes to be integrated to obtain a decorative plate.

A decorative board was obtained in the same manner as in Example 1, except that the number of prepregs was changed from 4 to 1.

A decorative board was obtained in the same manner as in Example 1, except that the number of prepregs was changed from 4 to 7.

(2) Manufacturing of decorative layer With a basis weight of 80 g/m ² , a printing liquid having a wood grain pattern printed on a decorative paper for a thermosetting resin decorative board is coated with a resin liquid containing an unsaturated polyester resin as a main component. A resin impregnated decorative paper (B) was manufactured by impregnation according to the calculation method defined in 1 so that the impregnation rate was 40% and drying. The unsaturated polyester resin used was one in which diallyl phthalate monomer was added after an esterification reaction using ethylene glycol, propylene glycol-fumaric acid, and isophthalic acid as raw materials, and baizeoyl peroxide was added as a curing agent.
A decorative board was obtained in the same manner as in Example 1 except that the resin-impregnated decorative paper (B) was used instead of the resin-impregnated decorative paper (A).

(1) The surface layer has a production basis weight of 28 g/m ² and an alumina mixed paper ratio of 5% on α-cellulose paper, and a resin solution containing a melamine-formaldehyde resin as a main component is used to calculate 300% by a calculation method shown in Formula 1. To obtain a resin-impregnated surface paper (B).
A decorative board was obtained in the same manner as in Example 1, except that the resin-impregnated surface paper (A) was used in place of the resin-impregnated surface paper (A).

In Example 5, the basis weight was 35 g/m ² and the mixing ratio of alumina was 25%, and the resin liquid containing melamine-formaldehyde resin as the main component was added to α-cellulose paper to obtain 150% by the calculation method shown in Formula 1. A decorative board was obtained in the same manner except that the decorative board was impregnated.

In Example 5, the basis weight was 40 g/m ² , and the mixing ratio of alumina was 25%. In α-cellulose paper, the resin liquid containing melamine-formaldehyde resin as the main component was calculated to be 150% by the calculation method shown in Formula 1. A decorative board was obtained in the same manner except that the decorative board was impregnated.

A decorative board was obtained in the same manner as in Example 1, except that the resin liquid containing a vinyl ester resin as the main component was impregnated by the calculation method defined by the equation 1 so that the impregnation rate was 17%.

A decorative board was obtained in the same manner as in Example 1 except that the resin liquid containing a vinyl ester resin as a main component was impregnated by the calculation method defined by the equation 1 so that the impregnation rate was 122%.

A decorative board was obtained in the same manner as in Example 1, except that the acrylic resin emulsion was impregnated in an amount of 16 parts by weight.

A decorative board was obtained in the same manner as in Example 1, except that the acrylic resin emulsion was impregnated to 55 parts by weight.

Example 1 was repeated in the same manner as in Example 1 except that the glass transition temperature (Tg) was 88° C. and the acrylic resin emulsion containing ethyl acrylate and methyl methacrylate as a main monomer and having an average particle size of 180 nm was used for impregnation. Obtained.

The same procedure as in Example 1 was performed except that the glass transition temperature (Tg) was −20° C. and the acrylic resin emulsion having butyl acrylate and methyl methacrylate as a main monomer and an average particle size of 230 nm was used for impregnation. Got

A decorative board was obtained in the same manner as in Example 1 except that calcium carbonate having an average particle size of 5 μm was used for impregnation instead of aluminum hydroxide having an average particle size of 8 μm.

A decorative board was obtained in the same manner as in Example 14 except that a 76 g/m ² glass fiber non-woven fabric was used to produce a prepreg and one prepreg was used as the core layer.

A decorative board was obtained in the same manner as in Example 14, except that a 96 g/m ² glass fiber non-woven fabric was used to produce a prepreg and one prepreg was used as the core layer.

A decorative plate was obtained in the same manner as in Example 14, except that a prepreg was manufactured using a 30 g/m ² glass fiber woven fabric and one prepreg was used as the core layer.

A decorative board was obtained in the same manner as in Example 14, except that a prepreg was produced using a glass fiber woven fabric of 60 g/m ² and one prepreg was used as a core layer.

In Example 14, a 76 g/m ² glass fiber nonwoven fabric and a 60 g/m ² glass fiber woven fabric were used to produce a prepreg, and a 76 g/m ² glass fiber nonwoven fabric as a core layer was used in order from the bottom. One prepreg, one prepreg using 60 g/m ² of glass fiber woven cloth, one resin-impregnated decorative paper (A) as a decorative layer, and one resin-impregnated surface paper (A) as a surface layer A decorative board was obtained in the same manner except that the laminated sheets were laminated.

A decorative board was obtained in the same manner as in Example 17, except that 30 g/m ² of polyester fiber woven fabric was used instead of 30 g/m ² of glass fiber woven fabric.

A decorative board was obtained in the same manner as in Example 19, except that 30 g/m ² of polyester fiber woven fabric was used instead of 60 g/m ² of glass fiber woven fabric.

In Example 15, as a binder, instead of an acrylic resin emulsion, 16 parts by weight of melamine-formaldehyde resin, 16 parts by weight of phenol-formaldehyde resin, and 240 parts by weight of aluminum hydroxide having an average particle diameter of 8 μm as an endothermic metal hydroxide. Parts, calcium carbonate having an average particle diameter of 5 μm was used as an inorganic filler, a prepreg was produced, and the same procedure was performed except that three prepregs were used as the core layer to obtain a decorative board.

Manufacture of Flooring A decorative board of Example 15 was laminated with a 2.5 mm polyvinyl chloride resin sheet using a urethane-based two-component reactive adhesive to obtain a flooring.

Manufacture of flooring A 2 mm foamed polyethylene resin sheet (foaming ratio: 5 times) was bonded to the decorative board of Example 15 using a urethane two-component reactive adhesive to obtain a flooring.

Comparative Example 1
(2) Manufacturing of decorative layer A resin liquid containing melamine-formaldehyde resin as a main component is defined by a mathematical expression 1 on a decorative paper for a thermosetting resin decorative board on which a wood grain pattern having a basis weight of 80 g/m ² is printed. The resin was impregnated into the resin so that the impregnation rate was 40% by the calculation method described above, and the resin impregnated decorative paper (C) was manufactured.
A decorative board was obtained in the same manner as in Example 1 except that the resin-impregnated decorative paper (C) was used in place of the resin-impregnated decorative paper (A), but a warp was large.

Comparative example 2
In Comparative Example 1, the decorative layer was impregnated so that the impregnation rate was 100%, and the impregnation rate was 50% by the calculation method defined by the mathematical formula 1 of the phenol-formaldehyde resin in the kraft paper of 200 g/m ^2. A decorative board was obtained in the same manner except that the prepreg was impregnated as described above, but the dimensional change rate was inferior.

Comparative Example 3
A decorative board was obtained in the same manner as in Comparative Example 1 except that α-cellulose paper having a basis weight of the surface layer of 28 g/m ² and a mixed paper ratio of alumina of 5% was used. It was inferior.

Comparative Example 4
In Comparative Example 3, a decorative board was obtained in the same manner except that an unsaturated polyester resin and a melamine-formaldehyde resin were used in place of the phenol-formaldehyde resin of the prepreg, but a decorative layer was adhered to the core layer. It was inferior. Also, the warp was great.

The evaluation results as a decorative board are shown in Tables 1 to 5. The parts by weight in the table are solid content values.

Table 6 shows an example of use as a floor material.

Evaluation of decorative board The test method was as follows.
(1) Thickness: Measured with a micrometer.
(2) Abrasion resistance (abrasion value): Measured based on JIS K 6902:2007 "Test method for thermosetting resin high-pressure decorative board".
(3) Dimensional change rate: Measured based on JIS K 6902:2007 "Test method for thermosetting resin high-pressure decorative board". Unmeasurable means that the warp was severe and the measurement could not be performed.
(4) Warpage:
4-1. A 50 mm x 280 mm test piece was cut out from the initial decorative board and measured. The fiber direction of the decorative board is parallel to the lateral direction of the test piece.
4-2.40° C.-24 hours The test piece was aged in an environment of 40° C. and a humidity of 30% for 24 hours. Then, the test piece was placed on a horizontal surface and the warpage was measured.
The warpage was measured with the surface layer facing upward.
When it is 100 mm or more, it means that the warp is too great to measure.

1a Surface layer 2a Decorative layer 3a Prepreg 3b Prepreg 4a Core layer 7a Decorative plate 7b Decorative plate 11a Thermoplastic resin sheet 21 Floor material

Claims (16)

A decorative board including a core layer, a decorative layer, and a surface layer in order from the bottom , wherein the surface layer contains a surface paper and a condensation type thermosetting resin, and the decorative layer is a resin containing only a decorative paper and a radical polymerization type resin. And the core layer includes a fibrous base material, an inorganic filler, and a binder resin. The decorative board according to claim 1, wherein the condensation-type thermosetting resin is a melamine -formaldehyde resin. The decorative board according to claim 1, wherein the radical-polymerizable thermosetting resin is a vinyl ester resin or an unsaturated polyester resin. The decorative board according to claim 1, wherein the fibrous base material is an inorganic fiber base material and/or an organic fiber base material. The decorative board according to claim 4, wherein the inorganic fiber base material is a glass fiber nonwoven fabric and/or a glass fiber woven fabric. The decorative board according to claim 1, wherein the inorganic filler is at least one selected from the group consisting of aluminum hydroxide, magnesium hydroxide, and calcium carbonate. The amount of the binder resin included in the core layer is 15 to 220 g/m. ^Two The decorative board according to claim 1, which is The decorative board according to claim 1, wherein the binder resin is at least one selected from the group consisting of acrylic resin emulsion, amino-formaldehyde resin, and phenol-formaldehyde resin. The decorative board according to claim 1, wherein the binder resin is an acrylic resin emulsion. The decorative board according to claim 8 or 9, wherein the acrylic resin emulsion has a glass transition temperature of -20 to 88°C. The decorative board according to claim 8, 9 or 10, wherein the acrylic resin emulsion has an average particle size of 150 to 300 nm. The decorative board according to claim 1, wherein the surface paper is a mixed paper surface paper containing an abrasion resistant material. The decorative plate according to claim 12, wherein the wear resistant material is alumina. The decorative sheet according to claim 12, wherein the mixed paper surface ratio of the mixed paper is 1 to 40%. A flooring material in which the decorative board according to any one of claims 1 to 14 and a thermoplastic resin sheet are laminated and integrated via an adhesive . The flooring material according to claim 15, wherein the thermoplastic resin sheet is a polyvinyl chloride resin sheet or a foamed polyethylene resin sheet.

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