JPH1044111A - Multilayered particle board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to suppress the releasing amount of formation generated to extremely small amount by a method wherein an isocyanate-based adhesive is employed in a core layer while a thermosetting synthetic resin adhesive in ordinary use is employed in a surface layer and, in addition, the whole surface is subjected to ammonium chloride treatment. SOLUTION: First of all, chips for surface layer are prepared by applying a thermosetting synthetic resin adhesive in ordinary use such as a phenol resin, melamine resin, urear resin or the like the fine wooden pieces while ships for surface layer are prepared by applying an isocyanate-based thermosetting adhesive, in and from which formation is neither employed for released, toe comparatively coarse grained wooden pieces. The ships for core layer manufactured by the above-mentioned process are placed on the chips for surface layer and further the chips of the surface layer are placed on the chips for core layer so as to form a predetermined formed mat. Next, to the formed may, thermocompression is carried out with a hot press. After that, by treating the whole surface of the hot-pressed board through the spraying of ammonium chloride solution, the formalin generating from the surface of the may is suppressed on order to complete a particle board.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multilayer particle board which has a small amount of formalin emission after production and has a smooth surface.

[0002]

2. Description of the Related Art Particle boards are made by applying a common thermosetting adhesive such as phenolic resin to a piece of wood obtained by subdividing wood into small pieces and hot-pressing it into a plate shape. Is widely used for furniture, fittings and building materials.

[0003]

However, the particle board according to the prior art is a thermosetting synthetic resin such as a phenol resin, a melamine resin, a urea resin, a urea melamine co-condensation resin, and a guanamine resin which are commonly used in the production thereof. Since the adhesive is synthesized using formalin, there is a problem that formalin is released from particle boards manufactured using the thermosetting synthetic resin adhesive or furniture and building materials manufactured from the particle boards. was there. In the case of a single-layer particle board, this can be suppressed to some extent by spraying an ammonium chloride solution on the surface, but in a multilayer particle board using a coarse wood chip for the core layer and a fine wood chip for the surface layer, However, there is a problem that the release of formalin cannot be prevented, but the release from the core layer cannot be prevented. Here, when an isocyanate-based adhesive is used as the adhesive, there is no formalin release, but there is a problem that the adhesive adheres to the hot platen during hot pressing and the molding mat is difficult to remove from the hot press. Further, even if the molding mat can be taken out from the hot press, there is a problem that the surface layer surface is formed with irregularities, resulting in a particle board having poor surface properties. The present invention has been made in view of such circumstances, and an object of the present invention is to provide a high-quality multilayer particle board having a smooth surface and a small amount of formalin emission.

[0004]

According to the present invention, there is provided a semiconductor device comprising:
In the multilayer particle board described above, an isocyanate-based adhesive is used for a core layer, a common adhesive such as a phenol resin, a melamine resin, or a urea resin is used for a surface layer, and the entire surface is treated with ammonium chloride.

The multilayer particle board according to the first aspect uses an isocyanate-based adhesive which does not release formalin in the synthesis process without using formalin as an adhesive for the core layer. No formalin is generated from the core layer. In addition, since a common adhesive such as a phenol resin, a melamine resin or a urea resin is used as the surface layer adhesive and the entire surface thereof is treated with ammonium chloride, the generation of formalin can be suppressed. And as the surface adhesive,
Since a common adhesive such as a phenol resin, a melamine resin or a urea resin is used, the adhesive does not adhere to the hot plate during the hot pressing process, and the surface is formed smoothly.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described to provide an understanding of the present invention. First, a conventional thermosetting adhesive is applied to a fine piece of wood (called a fine chip) to form a surface layer chip, and an isocyanate-based thermosetting adhesive is applied to a relatively open piece of wood (called a coarse chip). And a core layer chip.

Here, a common thermosetting adhesive is:
For example, phenol resin, melamine resin, urea resin, urea melamine co-condensation resin, refers to a conventionally used resin such as guanamine resin, and isocyanate-based thermosetting adhesive, for example, methylene cross-linked polyphenyl polyisocyanate A compound consisting of a compound having an isocyanate group such as a nate.

[0008] The addition rate of a conventional thermosetting adhesive is 10 to 15% by weight based on fine chips, and the addition rate of an isocyanate-based thermosetting resin is 5 to 10% by weight based on coarse chips.
And This is because a coarse chip has a smaller total surface area, so that only a small amount is required. When the addition rate of the usual thermosetting adhesive and the addition rate of the isocyanate-based thermosetting resin are smaller than the above-mentioned weight%, the strength of the product is insufficient, and when it is too large, the cost increases.

A core layer chip is mounted on the surface layer chip manufactured in the above process, and the surface layer chip is further mounted thereon to form a predetermined molding mat. Here, although it depends on the thickness of the particle board to be manufactured, the thickness of the core layer chip sandwiched between the upper and lower surface layer chips is about two to three times the thickness of the upper and lower surface layer chips. Next, the formed mat is hot-pressed by using a hot press, under the conditions that the hot-press time is 5 to 15 minutes, the hot-press temperature is 100 to 180 ° C, and the hot-press pressure is 20 to 30 kg. / Cm ² is optimal. After this,
The hot pressed board is sprayed with an ammonium chloride solution over the entire surface to suppress formalin generated from the surface, thereby completing a particle board.

In this embodiment, a single core layer has been described for simplicity of description, but the present invention is also applicable to a case where there are a plurality of core layers. In addition, in this embodiment, the thickness of the particle board was about 15 mm, but it may be changed to another thickness if necessary.
The present invention is applicable even when the type of the adhesive and the pressing conditions are changed. The present invention is applicable to an oriented board such as OSB.

[0011]

According to the first aspect of the present invention, in the multilayer particle board, an isocyanate-based adhesive which does not release formalin is used as an adhesive for the core layer without using formalin in the synthesis process. Since a common thermosetting synthetic resin adhesive is used as the adhesive and the entire surface thereof is treated with ammonium chloride, the amount of formalin generated can be suppressed to an extremely small amount. In addition, since a conventional thermosetting synthetic resin adhesive is used for the surface layer, the adhesive does not adhere to the hot press hot plate during hot pressing, and a high quality particle board with a smooth surface is used. Can be manufactured.

Claims (1)

[Claims] 1. A multi-layer structure comprising a core layer made of an isocyanate-based adhesive, a surface layer made of a conventional adhesive such as a phenol resin, a melamine resin or a urea resin, and furthermore, the entire surface is treated with ammonium chloride. Particle board.