JPH0260743A - Method for manufacturing aggregate blocks and method for manufacturing parquet pattern decorative board - Google Patents

Abstract

PURPOSE:To enhance bonding strength by a method wherein a plurality of woods not dried forcibly are gathered through a moisture curable polyurethane type binder, to which a powder of a highly water-absorbable high-molecular compound swollen by the absorption of water is added, and pressed. CONSTITUTION:A plurality of wet plate materials irregular in water content within a range of 20-60% are gathered through an adhesive applied therebetween in an amount of 80g/m<2> and pressed under pressure of 4kg/cm<2> for 2hr to form a gathered block. The adhesive is prepared by adding 2 pts.wt. of a particulate material (a mean particle size before the absorption of water: 100 mesh pass) of a highly water-absorbable high-molecular compound allowed to absorb 50 times by wt. of water to 100 pts.wt. of a moisture curable polyurethane type resin under stirring. The addition amount of the particulate material of the highly water-absorbable high-molecular compound is 0.2-15 pts.wt. per 100 pts.wt. of the adhesive and the particle size of the particulate material before swelling by the absorption of water is set to a size passing through a 50-mesh screen but not through a 300-mesh screen.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application 1] The present invention relates to a method for manufacturing a parquet pattern decorative board using an aggregate block and an intermediate plate obtained by cutting the aggregate block into thin pieces.

[Prior Art] Conventionally, as disclosed in Japanese Patent Publication No. 52-6329, a plurality of wet plate materials having a water content higher than the fiber saturation point are cured in water or high humidity between them. A laminated block is formed by laminating them together using an adhesive and cold-pressing them together. Next, this laminated block is cut thinly in the direction in which the laminated cross section of each plate material is obtained to obtain a decorative veneer with a marquetry pattern. A method of manufacturing a parquet-patterned building material characterized by pasting a board onto a substrate has been known.

[Problems to be Solved by the Invention] Moisture-curable polyurethane resin adhesives that are currently in general use have the disadvantage that if the moisture content of the board material is too low, the adhesive cannot be firmly bonded. In particular, when the temperature is high like in summer, the surface moisture content of wood is often less than 30%, and sometimes 2.
In some cases, it dropped to below 0%. Even in this case, the internal moisture content of the wood is higher than the surface, but moisture-curing polyurethane resin adhesives react with moisture on the very surface of the wood, so even if there is sufficient moisture inside the wood, moisture-curing polyurethane adhesives There was insufficient water to react with the resin adhesive, causing poor adhesion. Therefore, when the surface moisture content of wood was low, water was sprayed on the surface of the wood, but if too much water was sprayed, the moisture content on the surface became too high. When applying mold polyurethane resin adhesive, the adhesive may be diluted or foam excessively, resulting in a decrease in the adhesive strength of the board material. The problem was that it often peeled off from the adhesive.

[Means for Solving the Problems] This invention solves the above-mentioned drawbacks, and even if some of the wood used has a low surface moisture content, or if some of the wood has a low moisture content. The purpose of the present invention is to provide a method for manufacturing a set blow-drying board and a parquet-patterned decorative board that can be firmly bonded even when the wood is not force-dried. A method for producing an aggregate block, which involves forming an aggregate block by bringing together and pressurizing it via a moisture-curing polyurethane adhesive containing powder of a highly water-absorbing polymer compound, and forced drying. The first step is to form a collective block by bringing together and pressurizing a plurality of pieces of wood that have not been swollen by moisture using a moisture-curing polyurethane adhesive containing powder of a highly water-absorbing polymer compound that has been swollen by water absorption. The second step is to thinly cut this assembled block in the direction of obtaining a cross-section of the lumber to obtain a decorative veneer with a parquet pattern, and to paste this decorative veneer with a parquet pattern onto the board using an adhesive. The present invention relates to a method for manufacturing a parquet-patterned decorative board, characterized by comprising a third step of cladding.

Adding powder and granules of a highly water-absorbing polymer compound that has been swollen by water absorption into a moisture-curing polyurethane resin adhesive will help to reduce the amount of moisture that can be added to a moisture-curable polyurethane resin adhesive. When pressurized, moisture oozes out from the granular material of the superabsorbent polymer compound, making it possible to easily supply the moisture necessary for curing the moisture-curing polyurethane resin adhesive.

In this invention, the amount of the superabsorbent polymer compound powder added is preferably 0.2 to 15% by weight based on 100 parts by weight of the adhesive. This is because if it is less than 0.2% by weight, the desired effect cannot be expected, and if it is more than 15% by weight, the adhesive strength of wood tends to decrease and it is also economically disadvantageous.

In addition, the particle size of the powder of the super absorbent polymer compound is the water absorption W
The size is preferably such that it passes through a 50 mesh sieve before being moistened, but does not pass through a 300 mesh sieve. If the particle size of the superabsorbent polymer compound powder is too fine, the pot life will be shortened, and if it is too coarse, the distribution density of the powder in the moisture-curing polyurethane adhesive will become coarse, resulting in uniform adhesion. It's because you can't get power.

[Effects of the Invention] With the above-described configuration, the present invention can obtain aggregate blocks with high adhesive strength without any problems even if some of the wood used has a low surface moisture content, and can be used to This has the effect that even if the wood is cut thinly in the direction to obtain a joined cross section, the thin veneer will not easily peel off from the bonded portion.

It should be noted that there is an advantage in that an appropriate amount of moisture can be freely supplemented by adjusting the amount of superabsorbent polymer compound powder or granules added, rather than simply spraying water on the surface of the wood.

[Example 1] After smoothing the surface of a plurality of wet boards whose moisture content varies in the range of 20 to 60% using a planer, saw, etc., if necessary, they are bonded together as follows. The agent was applied at 80 g/m 2 , and the blocks were pressed together at 4 kg/cm 2 for 2 hours to form a collective block.

Adhesive Moisture-curable polyurethane resin 1 resin Adhesive A powder or granule of a highly water-absorbing polymer compound that has absorbed 50 times its weight of water (trade name "Aqualic") from Nippon Shokubai Chemical Co., Ltd. ) with an average particle size of 100 mesh pass before water absorption)
2 parts by weight (in a water-absorbed state) were added and stirred.

[Example 2] A collective block was formed in the same manner as in Example 1 except that the following adhesive was used.

Adhesive Moisture-curing polyurethane resin adhesive lOO on the overlapping part,
3 parts by weight of a powder of a highly water-absorbing polymer compound that has absorbed 100 times its weight of water (trade name: "Sunwet" manufactured by Sanyo Chemical Industries, Ltd., with an average particle size of 80 mesh) added and stirred (in a state of

[Comparative Example 1] The same procedure as in Example 1 was carried out except that a moisture-curable liquid polyurethane resin adhesive to which no powder or granular material of a superabsorbent polymer compound was added was used. to form a collective block.

[Comparative Example 2] In Example 1, a moisture-curable liquid polyurethane resin adhesive without the addition of superabsorbent polymer compound powder was used to increase the moisture content of the wood surface. An aggregate block was formed in the same manner as in Example 1, except that water was sprinkled for the purpose.

Example 1. The block shear force and wood breakage rate of the aggregate blocks of Example 2, Comparative Example 1, and Comparative Example 2 were measured, and the following results were obtained.

Block shearing force Wood breakage rate (Kg/cm2) (%) Example 1 98.3 30 Example 2 91.6 40 Comparative example 1 54.5 0 Comparative example 2 62.0 5 [Example 3] Example 1 Using a slicer, cut the assembled blocks obtained in 1.
．． A 3 mm parquet pattern decorative veneer was obtained, and this was adhered to a substrate via an adhesive to obtain a desired parquet pattern decorative veneer.

[Example 4] The aggregate block obtained in Example 2 was sliced thinly with a slicer in the direction that a cross section of the wood was assembled to obtain a thickness of 0.
．． A 3 mm parquet pattern decorative veneer was obtained, and this was adhered to a substrate via an adhesive to obtain a desired parquet pattern decorative veneer.

The parquet-patterned decorative veneers obtained in the middle of Examples 3 and 4 had a high adhesive strength at the mating surfaces, so they did not peel off from that part at all during normal handling of the veneers.

Claims (2)

[Claims] (1) Multiple pieces of wood that have not been force-dried are brought together and pressed together using a moisture-curing polyurethane adhesive containing powder of a highly water-absorbing polymer compound that has been swollen by water absorption to form an assembled block. A method for manufacturing an aggregate block, characterized by forming. (2) Multiple pieces of wood that have not been force-dried are brought together using a moisture-curing polyurethane adhesive containing powder of a highly water-absorbing polymer compound that has been swollen by water absorption, and then pressurized to form an assembled block. The first step is to form a decorative veneer with a parquet pattern, and the second step is to thinly cut this assembled block in the direction of obtaining a cross-section of wood pieces to obtain a decorative veneer with a parquet pattern.The decorative veneer with a parquet pattern is attached to a substrate via adhesive. A method for manufacturing a parquet pattern decorative board, comprising a third step of pasting the board.