JPS6412201B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a surface-decorated wood veneer that has excellent wear resistance, split resistance, and surface hardness, and has an appearance that does not impair the original texture of the wood board. The present invention relates to a method for producing surface-reinforced wood as a material. Conventionally, surface-reinforced wood that uses wood veneer as a surface decoration material has been used to protect and improve the appearance of the veneer after attaching the veneer to the base material such as plywood, fixtures, and structural materials with adhesive. For this purpose, it has been manufactured by applying coatings such as urethane resin and wax treatment to the surface of the veneer. However, the above treatment alone has the disadvantage that the surface hardness of the wood veneer is insufficient and the abrasion resistance and splitting resistance are poor. Various surface overlay treatments have been considered to eliminate these drawbacks, but in all of these treatments, the color tone characteristic of white wood fades due to heat pressing, resulting in a strong yellowish appearance. The problem was that the texture of the cloth was lost, and the product value was significantly reduced. In addition, even if a hardened film of impregnated paper cloth is created on the surface by overlay treatment, the wood veneer itself is soft, so
Another drawback was that the surface was easily scratched by impact. Moreover, cracks often occur in the wood veneer during such heat-pressing, which not only impairs the appearance of the resulting decorative surface but also causes delamination, which is difficult to achieve with conventional manufacturing methods. The high defect rate of the cosmetic base materials produced in this manner was also considered to be a major problem. The inventors of the present invention have conducted various studies in order to eliminate such drawbacks, and as a result, they have found that the purpose can be extremely well achieved by pre-treating the wood veneer with a specific resin composition, and have completed the present invention. I've reached it. That is, the present invention provides wood veneer with (A) a polyhydric alcohol component containing 50 mol% or more of at least one of propylene glycol, neopentylene glycol, and 1,3-butylene glycol, and isophthalic acid and terephthalic acid. at least 1
10-50 mol% of seeds and 90-90% of aliphatic polybasic acids
5 to 30 parts by weight of a saturated polyester resin obtained by reacting with an acid component containing 50 mol%; (B) a fat that may contain an aliphatic saturated polybasic acid or an aromatic polybasic acid or an anhydride thereof; Unsaturated polyester resins 95 to 40 obtained by reacting group unsaturated polybasic acids or their anhydride components with polyhydric alcohol components containing at least 50 mol% of side chain polyhydric alcohols and/or cyclic polyhydric alcohols. parts by weight, (C) 20 to 150 parts by weight of an unsaturated monomer copolymerizable with the unsaturated polyester resin, and (D) 0.3 to 10 parts by weight of a polymerization initiator (catalyst). The present invention provides a method for producing surface-reinforced wood, which comprises pre-treating the wood, overlaying a thermosetting resin-impregnated overlay paper cloth on the surface of the pre-treated veneer, and then hot-press molding the wood. The method of the present invention will be explained in detail below. In the polyester resin composition used in the present invention, succinic acid, glutaric acid, adipic acid, sebacic acid, azelaic acid, etc. are exemplified as aliphatic polybasic acids used in the synthesis of the saturated polyester resin as component (A). Ru. In the present invention, if the polyhydric alcohol component contains less than 50 mol% of at least one of propylene glycol, neopentylene glycol, and 1,3-butylene glycol, in the final prepared polyester resin composition,
At the same time as phase separation occurs, a sufficient shrinkage reduction effect cannot be obtained, and if at least one of isophthalic acid and terephthalic acid is used in the acid component in an amount exceeding 50 mol%, or if an aliphatic polybasic acid is used in an amount exceeding 50 mol%, If it is used in an amount less than mol%, the final polyester resin composition becomes insoluble and crystallized, making it difficult to put it into practical use.
At least one type of terephthalic acid is used in an amount less than 10 mol%, or an aliphatic polybasic acid is used in an amount of 90 mol%.
If the amount is exceeded, the strength of the final cured resin product will be significantly reduced, which is not preferable. In the synthesis of the unsaturated polyester resin which is component (B) in the present invention, as the aliphatic unsaturated polybasic acid or its anhydride, maleic anhydride, fumaric acid, citraconic acid, itaconic acid, etc. are used alone or as a mixture. It will be done. Polybasic acids or anhydrides thereof (hereinafter referred to as saturated polybasic acids) that can be used in combination with such unsaturated polybasic acids as necessary include, for example, phthalic acid, isophthalic acid,
Aromatic polybasic acids or their anhydrides such as terephthalic acid, phthalic anhydride, hexahydrophthalic anhydride, trimellitic acid, and pyromellitic acid, and aliphatic saturated polybasic acids such as succinic acid, glutaric acid, adipic acid, sebacic acid, and azelaic acid. Acid is given,
These can be used alone or in combination as a mixture of two or more. In this case, the strength of the molded product is improved compared to the case where a saturated polybasic acid is not used. Moreover, the amount of saturated polybasic acid is suitably 30 to 85 mol%. In addition, side chain polyhydric alcohols include polyhydric alcohols having alkyl groups in their side chains, such as α-propylene glycol, 1,3-butylene glycol, 1,2-butylene glycol, 2,3-butylene glycol, and neopentylene glycol. Cyclic polyhydric alcohol is bisphenol A.
Polyhydric alcohols having a cyclic structure such as propylene oxide adducts and hydrogenated bisphenol A, which can be used alone or as a mixture of two or more. In the present invention, if the side chain or/and cyclic polyhydric alcohol is less than 50 mol% in the polyhydric alcohol component for unsaturated polyester resin, the final polyester resin composition will undergo phase separation. The one-liquid nature, which is a feature of the present invention, is impaired. Here, ethylene glycol, diethylene glycol, etc. are suitable as polyhydric alcohols other than side chain polyhydric alcohols and cyclic polyhydric alcohols. Examples of monomers that can be copolymerized with the unsaturated polyester resin, which is component (C) in the present invention, include styrene, vinyltoluene, chlorostyrene,
Already known ones include divinylbenzene, diallyl phthalate, diallyl isophthalate, methyl methacrylate, ethyl acrylate, butyl acrylate, triallyl trimellitate, triallyl cyanurate, triallyl isocyanurate, etc., and these can be used alone. The copolymerizable monomer may also be a mixture, and this copolymerizable monomer acts as a crosslinking agent for the unsaturated polyester resin. The polymerization initiator (catalyst) which is component (D) used in the present invention includes benzoyl peroxide,
Examples of organic peroxides include methyl ethyl ketone peroxide and dicumyl peroxide. The resin composition used in the present invention may contain a colorant, an accelerator, an impregnating agent, and a saturated polyester resin and an unsaturated polyester resin other than components (A) and (B), if necessary. As the resin for overlay impregnation used in the present invention, known thermosetting resins such as melamine resin, diallyl phthalate resin, unsaturated polyester resin, and diallyl phthalate resin-unsaturated polyester resin mixture can be used. In view of performance, molding conditions, etc., unsaturated polyester resins and diallyl phthalate resins are preferred.
In addition, as the overlay paper cloth, α-cellulose paper, chemical fiber-based or glass fiber-based woven fabric, non-woven fabric, etc. that have high transparency after molding are used, but from the viewpoint of performance and moldability, chemical fiber-based non-woven fabrics are especially used. is preferred because it gives good results. The wood veneers of the present invention include cypress, Chinese cypress, rice cypress, spruce, Japanese pine, elm, and beech, which have a texture unique to white wood, and larch, cherry, and Japanese veneer, which have the effect of emphasizing wood grain. Wood species with a thickness of about 0.3 to 3 mm are used. When carrying out the present invention, first, a polymerization initiator (D) is added to a composition containing components (A), (B), and (C) of the resin composition of the present invention, and if necessary, a curing accelerator is added. ,
inhibitors or plasticizers, other polyester resins,
Polymerizable monomers or coloring agents such as pigments and dyes are added. Next, the thus prepared pretreatment resin liquid is uniformly applied to a wood veneer by a conventional method such as painting, dipping, or injection. When using the painting method, the wood veneer is attached to a base material such as plywood, fixture material, or structural material using an adhesive using a conventional method, and then the resin liquid is applied to the surface of the wood veneer using a roll coater or the like. It can be applied using a coating machine. In this case, the coating amount is preferably in the range of 60 to 120 g/ ^m2 ; if it is less than 60 g/ ^m2 , the intended purpose cannot be achieved, and if it exceeds 120 g/ ^m2 , it is uneconomical.
Thereafter, an overlay paper cloth is layered and subjected to hot pressure molding. On the other hand, when using the dipping method or the injection method, the wood veneer is immersed in the resin solution, and the resin-impregnated veneer is layered on a base material such as plywood, fixture material, or structural material, and then overlaid on top of it. Layer paper cloth and heat-press mold.
In this case, the amount of the resin attached to the wood veneer is
A range of 150 to 300 g/ ^m2 is preferred. In the case of the dipping method, the adhesion of the wood veneer to the base material and overlay processing can be performed at the same time during thermoforming, but if the amount of resin adhered to the veneer is less than 150g/ ^m2 , the veneer and the base Since the adhesive strength with the material is low, it is preferable to apply the resin liquid to the base material. Of course, an adhesive may be applied to the base material in advance, but an adhesive that inhibits the curing of the resin in the pretreated veneer should not be used. It is preferable to add an accelerator to the adhesive to accelerate the curing of the resin in the pretreated veneer. The thermoforming of the present invention is carried out at a temperature of 120 to 150°C and a pressure of 5 to 50°C.
It is carried out at 20 kg/cm ² for a time of 5 to 20 minutes, and can be appropriately selected depending on the resin liquid employed, the type of overlay resin, the thickness of the veneer, etc. The present invention will be explained below with reference to Examples. The numbers in the middle part of the examples indicate parts by weight, and the percentages in the middle part indicate weight percent. Reference example 1 Synthesis of saturated polyester resin 1.2 mol of isophthalic acid and 1.8 mol of adipic acid as polyhydric carboxylic acid components, propylene glycol
A saturated polyester resin with an acid value of 7 and a weight average molecular weight of 2.1×10 ⁴ was obtained by performing an esterification reaction with 0.375 mol and 2.7 mol of neopentylene glycol as a polyhydric alcohol component, and dissolving it with styrene monomer to form a solution with a resin content of 60%. (Sample A) was prepared. Reference Example 2 Synthesis of unsaturated polyester resin An unsaturated polyester resin with an acid value of 22 and a softening point of 57°C was obtained by performing an esterification reaction using 1.2 mol of phthalic anhydride, 1.8 mol of fumaric acid, and 3.6 mol of propylene glycol as reaction components. was dissolved with styrene monomer to prepare a solution (sample B) with a resin content of 60%. Example 1 20 parts of sample A, 70 parts of sample B obtained in Reference Examples 1 and 2,
A resin solution containing 3 parts of melamine resin (Sumimar M-55; product of Sumitomo Chemical Co., Ltd.), 10 parts of styrene monomer, and 2 parts of benzoyl peroxide was applied to the surface of the cypress veneer (0.6 mm thick cypress veneer with adhesive). (attached to plywood) at a rate of 90 g/m ² .
On top of this, 80 parts of diallyl phthalate prepolymer (Dapon 101; product of Sumitomo Chemical Co., Ltd.), 20 parts of iso-unsaturated polyester resin (Smearp P-1; product of Sumitomo Chemical Co., Ltd.), 4 parts of benzoyl peroxide, and 120 parts of acetone are added. A non-woven fabric made of acrylic fibers was immersed in a resin solution and dried at 80℃ for 10 minutes, and a resin-impregnated overlay fabric with a resin adhesion amount of 130g/m ² was layered at 130℃, a pressure of 10Kg/cm ² , and a pressing time of 10 minutes.
The natural wood decorative plywood was formed in minutes and thus fulfilled the intended purpose. (See Table 1) Example 2 The same operation as in Example 1 was performed on the surface of larch veneer (0.4 mm thick larch veneer adhered to plywood via adhesive), and the wood grain was clearly defined. Obtained natural decorative plywood. (See Table 1) Comparative Example 1 Ortho-unsaturated polyester resin (smear-up
MG-1, reaction product of phthalic anhydride, maleic anhydride, and propylene glycol; Sumitomo Chemical product) 70
Example 1 was carried out using a resin solution obtained by thoroughly mixing 20 parts of dibutyl phthalate, 3 parts of melamine resin (Sumimar M-55; product of Sumitomo Chemical Co., Ltd.), 10 parts of styrene monomer, and 2 parts of benzoyl peroxide. Natural wood decorative plywood was created in the same manner. The surface of the decorative plywood thus obtained was markedly yellowed, reducing its commercial value as a Japanese cypress wood. (Table 1
Reference) Comparative Example 2 A natural wood decorative plywood was prepared in the same manner as in Comparative Example 1 using larch veneer. The resulting decorative plywood had an appearance with a blurred grain characteristic of larch pine. (See Table 1) Comparative Example 3 In place of the ortho-unsaturated polyester resin of Comparative Example 1, an isophthalic acid-based unsaturated polyester resin (Smearup p-1, a reaction product of isophthalic acid, maleic anhydride, and propylene glycol; Sumitomo Chemical Co., Ltd. Similar operations were carried out using a commercially available product), but the surface of the resulting decorative plywood was significantly yellowed. (Table 1
Reference) Comparative Example 4 Instead of the ortho-unsaturated polyester resin of Comparative Example 1, a bisphenol-based unsaturated polyester resin (Smearp SX-6, maleic anhydride and 2,2-
Although a reaction product of di(4-hydroxypropoxyphenyl)propane and propylene glycol (product of Sumitomo Chemical Co., Ltd.) was used, the same results as in Comparative Examples 1 and 2 were obtained. (See Table 1) Comparative Example 5 Epoxy acrylic resin (Smearp EVR-
911, a reaction product of bis-based epoxy resin and methacrylic acid; 100 parts of Sumitomo Chemical Co., Ltd. product), and 2 parts of benzoyl peroxide were mixed well, and a resin solution obtained was prepared in the same manner as in Example 1 to prepare natural wood decorative plywood. did. The surface of the obtained decorative plywood was markedly yellowed, reducing its commercial value as a Japanese cypress wood.
(See Table 1) [Table]

Claims (1)

[Scope of Claims] 1 A wood veneer comprising: (A) a polyhydric alcohol component containing 50 mol% or more of at least one of propylene glycol, neopentylene glycol, and 1,3-butylene glycol; isophthalic acid; at least 1 of terephthalic acid
10-50 mol% of seeds and 90-90% of aliphatic polybasic acids
5 to 30 parts by weight of a saturated polyester resin obtained by reacting with an acid component containing 50 mol%; Unsaturated polyester resin 95-40% by weight made by reacting a saturated polybasic acid or anhydride component thereof with a polyhydric alcohol component containing at least 50 mol% of a side chain polyhydric alcohol or/and a cyclic polyhydric alcohol (C) 20 to 150 parts by weight of an unsaturated monomer copolymerizable with the unsaturated polyester resin, and (D) 0.3 to 10 parts by weight of a polymerization initiator. . A method for producing surface-decorated reinforced wood, which comprises superimposing a thermosetting resin-impregnated overlay paper cloth on the surface of the pretreated veneer and hot-pressing it. 2. The method for producing surface-decorated reinforced wood according to claim 1, wherein the polyester resin composition further contains a colorant.