Decorative plate

Abstract

To provide a decorative plate which has high mechanical characteristics such as tensile strength and good durability such as boiling resistance even when using a plant-derived resin material, and suppresses a formaldehyde emission amount.SOLUTION: A decorative plate includes a core layer and a decorative layer. The core layer contains one or more prepregs, where the prepreg is formed by impregnating a fibrous base material with a resin liquid containing a furan resin and drying the fibrous base material, and preferably, the resin liquid further contains furfuryl alcohol.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a decorative laminate. [Background technology]

[0002] Thermosetting resin decorative panels are available in a wide range of colors and patterns, and have excellent physical and chemical properties such as impact resistance, bending strength, and stain resistance, as well as ease of maintenance, so they are used in a wide range of applications, from furniture and fixtures in public facilities such as stores and medical and welfare facilities to residential furniture.

[0003] Generally, thermosetting resin decorative boards can be manufactured by laminating a decorative layer, a core layer, etc., and then thermocompressing them. The decorative layer can be manufactured using resin-impregnated decorative paper, which is made by impregnating decorative paper for decorative boards with a resin liquid containing a thermosetting resin such as melamine resin and drying it, and the core layer can be manufactured using one or more prepregs, which are made by impregnating a fibrous base material with a resin liquid containing a binder resin (e.g., phenolic resin) and then drying it. In addition, a backing layer and a surface protective layer can be provided as necessary.

[0004] In recent years, biomass resources that are not dependent on petroleum resources have been attracting attention, and in various technical fields, petroleum-derived raw materials are being replaced with plant-derived raw materials.

[0005] The applicant previously invented a decorative board using a lignin-based phenolic resin containing lignin, a plant-derived raw material. Specifically, the applicant succeeded in manufacturing a decorative board using a prepreg as the core layer, which is made by impregnating a fibrous substrate with a resin liquid containing a lignin-based phenolic resin as a binder resin and then drying it (Patent Document 1). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2022-147272

[0007] However, decorative panels made with lignin-based phenolic resins, which contain lignin, a plant-derived raw material, have room for improvement due to their relatively low mechanical properties such as tensile strength and durability such as boiling resistance. Furthermore, there are concerns about the harmful effects of formaldehyde emissions on the human body and the environment, and further reductions are needed. Summary of the Invention [Problem to be solved by the invention]

[0008] The problem that the present invention aims to solve is to provide a decorative panel that uses plant-derived resin materials, yet has high mechanical properties such as tensile strength, good durability such as boiling resistance, and reduced formaldehyde emissions. [Means for solving the problem]

[0009] The present invention provides a decorative board comprising a core layer and a decorative layer, the core layer comprising one or more prepregs, the prepregs being formed by impregnating a fibrous base material with a resin liquid containing a furan resin and then drying the impregnated resin liquid. [Effects of the Invention]

[0010] The decorative board of the present invention has the advantages of having high mechanical properties such as tensile strength, good durability such as boiling resistance, and reduced formaldehyde emissions, even though it uses a plant-derived resin material. DETAILED DESCRIPTION OF THE INVENTION

[0011] <Decorative board> The decorative board according to the present invention includes a core layer and a decorative layer. For example, the decorative layer is laminated on the core layer as the bottom layer, and then the laminate is sandwiched between pressure plates for thermocompression molding, and thermocompression molding is performed under conditions of a temperature of 120 to 160°C, a pressure of 2 to 10 MPa, and a time of about 30 minutes to 3 hours.

[0012] (core layer) The decorative board according to the present invention includes a core layer, which is made of one or more prepregs made by impregnating a fibrous base material with a resin liquid containing a binder resin and the like and then drying the prepreg.

[0013] Examples of the fibrous substrate include an organic fibrous substrate and an inorganic fibrous substrate.

[0014] As the organic fiber substrate, wood pulp fibers are preferred because they improve the biomass content, and examples thereof include paper made from bleached or unbleached kraft pulp of softwood or hardwood, sulfite pulp, or other wood pulps, either alone or in combination. Other examples include fibers made from polyethylene, polypropylene, vinylon, polyvinyl chloride, polyvinylidene chloride, polyacrylonitrile, polyamide, polyester, polyurethane, and modified products thereof, as well as fibers made from various copolymers such as ethylene-vinyl acetate copolymer, and composite fibers made from mixtures of these.

[0015] Examples of inorganic fiber substrates include nonwoven fabrics and woven fabrics containing glass fiber, rock wool, carbon fiber, and the like.

[0016] The basis weight of the fibrous base material is 30 to 400 g / m, taking into consideration the strength and impregnation efficiency of the decorative board. 2 It is preferable that the density is 50 to 350 g / m 2 When the thickness is within this range, the impregnation property of the resin liquid tends to be improved.

[0017] The resin liquid contains furan resin, furfuryl alcohol, and additives and fillers.

[0018] Furan resins are often used in Japan for casting applications. Specific synthesis methods include the condensation reaction of furfural with phenols, furfuryl alcohol with aldehydes, and furfuryl alcohol itself, all under an acidic or basic catalyst. Additives can also be added to produce modified products.

[0019] Furfural can be synthesized from components extracted from corn cobs, and furfuryl alcohol can be synthesized by the reduction of furfural. In particular, corn cobs are not used for food, so furan resin has the advantage of not competing with the current food shortage. This has made furan resin a popular non-edible biomass plastic.

[0020] When a furan resin is obtained by a condensation reaction of furfural with a phenol, phenol, cresol, xylenol, octylphenol, phenylphenol, resorcinol, bisphenol A, bisphenol S, bisphenol F, etc. can be used as the phenol.

[0021] Furthermore, when a furan resin is obtained by a condensation reaction of furfuryl alcohol with an aldehyde, examples of the aldehyde include formaldehyde, paraformaldehyde, trioxane, acetaldehyde, paraldehyde, glyoxal, hexamethylenetetramine, phenylacetaldehyde, o-tolualdehyde, benzaldehyde, and furfural.

[0022] When synthesizing a furan resin, it can be modified by adding an amino compound, such as melamine, urea, ethylene urea, urea derivatives, benzoguanamine, or acetoguanamine.

[0023] The reaction temperature when synthesizing the furan resin is preferably about 60°C to 160°C, and particularly preferably about 70°C to 140°C. The reaction time is preferably about 45 minutes to 8 hours, and particularly preferably about 1 hour to 6 hours. By keeping the reaction time within this range, the furan resin can be synthesized efficiently, which tends to improve productivity.

[0024] Examples of acidic catalysts used in the synthesis of furan resin include arylsulfonic acid, paratoluenesulfonic acid, hydrochloric acid, sulfuric acid, nitric acid, adipic acid, succinic acid, phosphoric acid, boric acid, acetic acid, formic acid, and oxalic acid. Examples of basic catalysts include hydroxides of alkali metals and alkaline earth metals, amines such as triethylamine and triethanolamine, and ammonia.

[0025] In the present invention, the furan resin may further contain furfuryl alcohol. The inventors of the present invention have found that the inclusion of furfuryl alcohol can suppress thickening, thereby improving impregnation properties and tending to increase the elastic modulus of the produced decorative board.

[0026] The reason for this effect is presumably that furfuryl alcohol has a low molecular weight, which results in a diluting effect and an ability to inhibit thickening, and that it has a tendency to react violently and generate heat, which results in an ability to increase the reactivity of the furan resin.

[0027] Furfuryl alcohol is preferably contained in an amount of 1 to 300 parts by weight, more preferably 3 to 100 parts by weight, even more preferably 5 to 50 parts by weight, and particularly preferably 10 to 35 parts by weight, converted into solid content relative to 100 parts by weight of the furan resin.

[0028] Furthermore, the resin liquid may contain a filler, which is mainly an inorganic filler, such as an endothermic metal hydroxide or other fillers.

[0029] Examples of endothermic metal hydroxides include aluminum hydroxide, magnesium hydroxide, calcium hydroxide, etc., and aluminum hydroxide is particularly preferred. These contain water of crystallization and decompose at high temperatures to release water, resulting in an endothermic reaction. This has the effect of suppressing temperature rise during combustion, and makes it possible to improve the non-combustibility of the decorative board of the present invention.

[0030] The average particle size of the endothermic metal hydroxide can be, for example, 1 to 50 μm. Within this range, dispersibility in the resin liquid and impregnation into the fibrous substrate tend to be improved. Furthermore, the surface of the decorative board is finished smoothly, thereby suppressing appearance defects. The average particle size in the present invention is the arithmetic mean diameter calculated from the particle size distribution (volume distribution) detected by laser diffraction / scattering method (Microtrac method).

[0031] Other fillers include, for example, carbonates such as calcium carbonate, magnesium carbonate, and zinc carbonate, silica, talc, and fly ash, and calcium carbonate is particularly preferred. The use of calcium carbonate tends to further improve workability during the manufacturing process and machinability after manufacturing. Both heavy calcium carbonate and light calcium carbonate (precipitated calcium carbonate) can be used as calcium carbonate.

[0032] When other fillers are used, their average particle size can be, for example, 0.05 to 30 μm. By keeping the average particle size within this range, the dispersibility in the resin liquid and the impregnation into the fibrous substrate tend to be improved. Furthermore, the surface of the decorative board is finished smoothly, thereby suppressing poor appearance.

[0033] When an endothermic metal hydroxide is used in combination with another filler, the amount of the other filler is preferably 5 to 500 parts by weight, and particularly preferably 30 to 300 parts by weight, per 100 parts by weight of the endothermic metal hydroxide. Within this range, a decorative board with a smooth and good surface appearance can be obtained, the decorative board has good flame retardancy, and the endothermic metal hydroxide is less likely to settle, which tends to improve the impregnation of the resin liquid.

[0034] When impregnating a fibrous base material with resin liquid, the impregnation rate, as calculated by the formula 1, is preferably 5 to 200%, more preferably 10 to 150%, and particularly preferably 20 to 100%. Within these ranges, the smoothness of the core layer is improved, resulting in a good appearance of the decorative board, and the impregnation of the resin liquid tends to be improved. Furthermore, the adhesion between core layers and between the core layer and the decorative layer is improved, which tends to prevent delamination of the decorative board. In Formula 1, the weight before impregnation refers to the weight of the fibrous base material (or decorative paper or surface paper, described below), and the weight after impregnation refers to the weight after the material is impregnated with the resin liquid and dried. Impregnation rate (%) = (weight after impregnation - weight before impregnation) / weight before impregnation × 100 (1)

[0035] (decorative layer) The decorative board according to the present invention includes a decorative layer, which is resin-impregnated decorative paper obtained by impregnating decorative paper for decorative boards with a resin liquid containing a thermosetting resin such as melamine resin and then drying the same.

[0036] The basis weight of decorative paper is 30 to 400 g / m 2 It is preferable that the density is 50 to 250 g / m 2 It is particularly preferable that the thickness is within this range. By keeping the thickness within this range, the surface properties of the decorative sheet and the impregnation ability of the resin liquid tend to be improved. As the decorative paper, colored paper or paper with various patterns printed thereon can be appropriately used.

[0037] As the thermosetting resin, an amino-formaldehyde resin, a phenol-formaldehyde resin, a radical polymerization type thermosetting resin, etc. can be used.

[0038] Examples of amino-formaldehyde resins include condensates obtained by reacting an amino compound with an aldehyde compound, and modified products thereof.

[0039] Examples of amino compounds include melamine, urea, ethylene urea, urea derivatives, benzoguanamine, and acetoguanamine. Examples of aldehyde compounds include formaldehyde, paraformaldehyde, trioxane, acetaldehyde, paraldehyde, glyoxal, hexamethylenetetramine, phenylacetaldehyde, o-tolualdehyde, and benzaldehyde.

[0040] It can also be etherified with a lower alcohol such as methyl alcohol, ethyl alcohol, or butyl alcohol, or modified with a reactive modifier such as paratoluenesulfonamide that promotes plasticization.

[0041] Among these, melamine-formaldehyde resin is preferably used because of its excellent heat resistance and abrasion resistance.

[0042] Examples of phenol-formaldehyde resins include condensates obtained by reacting a phenolic compound with an aldehyde compound in the presence of an acidic or basic catalyst, and modified products thereof.

[0043] Examples of the phenolic compounds include phenol, cresol, xylenol, octylphenol, phenylphenol, bisphenol A, bisphenol S, and bisphenol F, and examples of the aldehyde compounds include the compounds mentioned above.

[0044] It can also be modified with a reactive modifier that promotes plasticization, such as urea, ethylene urea, urea derivatives, paratoluenesulfonamide, tung oil, phosphate esters, glycols, etc.

[0045] Examples of the radical polymerization type thermosetting resin include unsaturated polyester resin, vinyl ester resin, diallyl phthalate resin, and mixtures thereof.

[0046] The unsaturated polyester resin can be obtained by adding a polymerizable monomer to an unsaturated polyester obtained by reacting a dihydric alcohol with a dibasic acid through esterification.

[0047] Examples of dihydric alcohols include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1,3-butylene glycol, neopentyl glycol, etc. Examples of dibasic acids include maleic acid, maleic anhydride, fumaric acid, isophthalic acid, terephthalic acid, phthalic acid, phthalic anhydride, and adipic acid.

[0048] Examples of the polymerizable monomer include styrene, orthochlorostyrene, diallyl phthalate, methyl methacrylate, etc. When curing, an organic peroxide such as benzoyl peroxide, methyl ethyl ketone peroxide, cyclohexanone peroxide, acetylacetone peroxide, acetoacetic acid peroxide, etc., may be added as a curing agent, and if necessary, a curing accelerator such as a cobalt complex salt may be added.

[0049] The vinyl ester resin can be obtained by reacting an epoxy resin with an unsaturated monobasic acid in the presence of an esterification catalyst.

[0050] Examples of epoxy resins include bisphenol A epoxy resins, halogenated bisphenol A epoxy resins, diglycidyl ethers of adducts of bisphenol A with alkylene oxides such as ethylene oxide or propylene oxide, bisphenol F epoxy resins, novolac epoxy resins, and cresol novolac epoxy resins.

[0051] Examples of unsaturated monobasic acids include acrylic acid, methacrylic acid, crotonic acid, monomethyl maleate, monopropyl maleate, sorbic acid, and mono(2-ethylhexyl) maleate. Examples of polybasic acids used in combination with unsaturated monobasic acids 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 acids. Examples of dibasic acid anhydrides include maleic anhydride and phthalic anhydride. Modified products using trimellitic anhydride as a tribasic acid anhydride can also be used.

[0052] 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; imidazole compounds such as 2-ethyl-4-methylimidazole; phosphonium salts such as tetramethylphosphonium chloride, diethylphenylpropylphosphonium chloride, triethylphenylphosphonium chloride, benzyltriethylphenylphosphonium chloride, dibenzylethylmethylphosphonium chloride, benzylmethyldiphenylphosphonium chloride, and tetraphenylphosphonium bromide; secondary amines; tetrabutylurea; triphenylphosphine; tritolylphosphine; and triphenylstibine.

[0053] (Surface protective layer) The decorative board according to the present invention may have a surface protective layer laminated on the outermost surface thereof. The surface protective layer is a resin-impregnated surface paper obtained by impregnating a surface paper for decorative board with a resin liquid containing a thermosetting resin and drying it.

[0054] Examples of surface paper for decorative sheets include α-cellulose paper, cloth, nonwoven fabric, etc. It is particularly preferable to use α-cellulose paper, which becomes transparent or translucent after the thermosetting resin is cured.

[0055] Furthermore, abrasion-resistant surface paper containing abrasion-resistant powder can also be used, which tends to improve the abrasion resistance of the decorative laminate. Examples of abrasion-resistant powder include inorganic powders such as aluminum oxide, silicon carbide, and silicon oxide. Abrasion-resistant surface paper contains 1 to 40% by weight, more preferably 5 to 30% by weight, of abrasion-resistant powder mixed with α-cellulose paper, and has a basis weight of 5 to 80 g / m. 2 , more preferably 10 to 60 g / m 2 By keeping the content within this range, it is possible to prevent a decrease in the clarity of the printed pattern on the decorative paper.

[0056] The resin liquid contains a thermosetting resin. Examples of the thermosetting resin include the above-mentioned amino-formaldehyde resin, phenol-formaldehyde resin, and radical polymerization type thermosetting resin. Among these, in order to improve heat resistance and abrasion resistance, it is preferable to use an amino-formaldehyde resin, and it is particularly preferable to use a melamine-formaldehyde resin. Furthermore, the resin liquid may also contain the above-mentioned filler as appropriate.

[0057] The decorative board of the present invention can be obtained by laminating a core layer, a decorative layer, and optionally a surface protective layer, sandwiching them between hot-press molding plates, and hot-press molding them using a press such as a flat press or continuous press.

[0058] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to these descriptions. [Example]

[0059] Example 1 In the production of the core layer, a fibrous base material having a basis weight of 200 g / m 2 I prepared some craft paper. Also, a resin liquid containing 100 parts by weight of furan resin and 4 parts by weight of a curing catalyst (a mixture of arylsulfonic acid and sulfuric acid) was prepared. Water and methanol were then added to the resin liquid, and the resulting mixture was impregnated into craft paper so that the impregnation rate was 50% as calculated by Equation 1, followed by drying at 110°C for 2 minutes and 30 seconds to produce a prepreg. Four sheets of this prepreg were laminated to form a core layer, and then a resin-impregnated decorative paper was laminated to form the decorative layer. Using a hot-press molding backing plate, the laminate was subjected to hot-press molding under conditions of 135°C, 5.9 MPa, and 60 minutes to obtain the decorative board according to Example 1. The resin-impregnated decorative paper had a basis weight of 120 g / m. 2 The decorative paper for decorative panels was impregnated with a resin liquid containing 100 parts by weight of melamine-formaldehyde resin and 1 part by weight of a curing catalyst (product name: Catanite A), and then dried at 120°C for 2 minutes to produce the product.

[0060] <Other Examples> In Example 2, a decorative board was obtained in the same manner as in Example 1, except that a resin liquid consisting of 100 parts by weight of furan resin, 4 parts by weight of a curing catalyst (a mixture of arylsulfonic acid and sulfuric acid), and 20 parts by weight of furfuryl alcohol was used. In Comparative Example 1, a decorative board was obtained in the same manner as in Example 1, except that a lignin-based phenolic resin was used as the resin liquid. In particular, in Example 2, impregnation was good, and productivity was very high.

[0061] The decorative boards obtained in each example were evaluated for the following physical properties. The evaluation results are shown in Table 2. Appearance: The appearance of the decorative board after thermocompression molding was visually observed. Dimensional stability: The rate of change in the longitudinal and transverse directions was measured according to JIS K 6902. Tensile test: Measurements were carried out in the longitudinal and transverse directions based on JIS K 7162. Elastic modulus: Based on JIS K 7171, the decorative surface load and back surface load were measured in the vertical and horizontal directions. Boiling resistance: Based on JIS K 6902, the increase in weight and thickness was measured, and the appearance after boiling was visually observed. Formaldehyde emission rate: Based on JIS A 1460:2021 "Test method for formaldehyde emission rate of building boards - desiccator method," the test was measured over a 22-hour period.

[0062] [Table 1]

[0063] The decorative board of Example 1, even though it uses a plant-derived resin material, had the effects of high mechanical properties such as tensile strength, good durability such as boiling resistance, and reduced formaldehyde emission. Furthermore, the decorative board of Example 2 had the above effects, and in particular the effect of increasing the elastic modulus. On the other hand, the decorative board of Comparative Example 1 did not have the above effects.

Claims

1. a core layer and a decorative layer, The core layer includes one or more prepregs, The prepreg is formed by impregnating a fibrous base material with a resin liquid containing a furan resin and drying the impregnated resin liquid. The decorative layer is a decorative board obtained by impregnating decorative paper for decorative boards with a resin liquid containing a melamine-formaldehyde resin and drying the impregnated paper, A decorative board characterized in that, as measured by boiling resistance (JIS K 6902), the weight increase rate is 12.7% or less and the thickness increase rate is 14.2% or less.

2. 2. The decorative board according to claim 1, wherein the resin liquid further contains furfuryl alcohol.

3. 3. The decorative board according to claim 2, wherein the resin liquid contains 1 to 300 parts by weight of furfuryl alcohol per 100 parts by weight of the furan resin.