JP2779885B2 - Manufacturing method of composite board - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a composite board which can be used as a board for building and a board for furniture.

[0002]

2. Description of the Related Art In recent years, there has been a demand for architectural or furniture materials in place of Rawan timber to protect tropical rainforests. For this reason, it is conceivable to use coniferous forest as a renewable timber resource.However, softwood lumber has a softer and rougher surface than southern lumber represented by lauan timber. It had to be used as a composite board in combination with.

A composite board is formed by bonding softwood and other base materials, for example, a hardwood board, an inorganic board such as a wood fiber board such as MDF, a calcium carbonate board, a calcium silicate board, or a metal board via an adhesive. In the case of manufacturing, when heat and pressure are applied, the composite board warps due to a change in water content. In order to eliminate this warpage, it is conceivable to produce a composite board by cold-pressing using an adhesive such as aqueous vinyl urethane or urea resin, but in this case, a long cold-pressing time is required, which is a major problem in productivity. was there.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and to manufacture a composite board without warping without reducing productivity.

[0005]

According to the present invention, a self-emulsifying isocyanate compound is applied to one surface of one of the two boards, at least one of which is a softwood, when the two boards are joined via an adhesive. After applying a compound capable of reacting with the self-emulsifying isocyanate compound to one surface of the other plate, the surface coated with the self-emulsifying isocyanate compound and the surface coated with the compound capable of reacting with the self-emulsifying isocyanate compound are overlapped. And compressing the composite plate.

In the present invention, the other plate material to be bonded to the softwood material may be any board material such as a hard board, an MDF, a calcium carbonate plate, a calcium silicate plate, and a metal plate.

In the present invention, the compound capable of reacting with the self-emulsifying isocyanate compound includes a modified vinyl acetate resin,
There are aqueous adhesives such as polyvinyl alcohol. It is also possible to add a curing catalyst (curing accelerator) such as an amine or an organometallic compound to the aqueous adhesive.
Amines include triethylamine, tetramethylguanidine, triethylenediamine, dimethylaminoethanol, and the like, and organometallic compounds include dibutyltin dilaurate, stannas octoace, dibutyltin carboxylate, and lead octenoate. The use of the water-based adhesive eliminates the need to use an organic solvent, which helps to improve the working environment. Which of the two plate materials is to be coated with the self-emulsifying isocyanate compound or a compound capable of reacting with the self-emulsifying isocyanate compound depends on the water absorption of the plate material and the self-emulsifying isocyanate compound, which reacts with the self-emulsifying isocyanate compound. It can be determined in consideration of the viscosity of the resulting compound, but in most cases either may be used.

[0008]

Since the present invention is constructed as described above, the warpage of the composite plate is extremely reduced and the pressing time can be greatly reduced in the production of the composite plate. Therefore, if necessary, continuous pressing can be performed, and energy consumption can be saved because hot pressing by high temperature is not required. In addition, the self-emulsifying isocyanate compound can be adjusted in viscosity by water, so that it does not require an organic solvent, which helps to improve the working environment, and is harder to penetrate into the base material than ordinary solvent-diluted isocyanate compounds. Can be firmly bonded.

[0009]

Example 1 1 part by weight of a self-emulsifying isocyanate compound was stirred and dispersed in 1 part by weight of water.
Apply 150 g / m ² to the surface of a mm softwood plywood. On the other hand, an aqueous emulsion having a functional group
100 g / m ² applied to the back of DF, 5 kgf / cm ²
And then cured for one day to obtain the desired composite board. The normal adhesive strength of this composite board is 31.2 kgf
/ Cm ² (100% wood breakage), and the boiling adhesive strength was 28.1 kgf / cm ² (100% wood breakage).
In addition, 100% of a wood fracture shows that it was not broken at the adhesive interface.

[0010]

COMPARATIVE EXAMPLE 1 A composite board was obtained in the same manner as in Practical Example 1 using aqueous vinyl urethane as an adhesive, but could not be bonded.

[0011]

Example 2 A desired composite plate was obtained by using a calcium silicate plate having a thickness of 6 mm instead of the MDF of Example 1.

[0012]

[Embodiment 3] Instead of the MDF of the embodiment 1, the thickness is 0.5 m.
The desired composite plate was obtained using an iron plate of m.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) B32B 1/00-35/00 B27D 1/00-5/00

Claims (1)

(57) [Claims] When joining two boards, at least one of which is softwood, via an adhesive, a self-emulsifying isocyanate compound is applied to one surface of one of the boards.
On one side of the other plate is a self-emulsifying isocyanate compound
After applying a compound that can react with the product,
Surface coated with socyanate compound and self-emulsifying isocyanate
A method for producing a composite board, comprising superimposing and pressing a surface coated with a compound capable of reacting with a nate compound .