JPS5820435A - Production of fibrous plate with surface part reinforced - Google Patents

Abstract

PURPOSE:To enhance surface hardness, nail-holding force, bending strength, water resistance of surface and the like, by a method wherein a composition for forming a foamed body of a synthetic resin is coated on a surface part of a fibrous plate, and the composition is brought into reaction while pressing the surface part. CONSTITUTION:A foamable synthetic resin liquid composition containing a synthetic resin such as a styrene resin, an acrylic resin, a phenolic resin, etc. and a foaming agent which generates a decomposition gas under heating, is prepared. For example, a foamable synthetic resin liquid composition containing 100pts.wt. of a phenolic resin and 3-5pts.wt. of toluenesulfonyl hydrazide as the foaming agent, is prepared. After coating the resin liquid composition on the surface of a wood fibrous plate having an intermediate or low specific gravity such as a soft fibrous plate, the liquid composition is uniformly spread by pressing by a roller or the like as required to impregnate the resin liquid into the surface part of the fibrous plate. Then, the liquid composition is brought into reaction while pressing the fibrous plate by a pressing device such as a flat-plate press to foam the composition.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a surface layer im reinforced fiberboard whose surface layer portion is reinforced with a synthetic resin foam layer.

Traditionally, fiberboards such as wood fiberboards and mineral fiberboards have been widely used as base materials for buildings and substrates for decorative laminates as materials that are lightweight, have excellent heat insulation properties, and are easy to process such as cutting. ing.

However, the above-mentioned fiberboard has a rough, fluffy surface and has low surface hardness, so it is easily damaged, and even compared to plywood, it has poor nail retention strength, bending strength, etc. Since it has poor mechanical properties and performance such as water absorption and water resistance, it has the disadvantage that the method and range of use are limited.

For example, when used as a construction base material such as a cloth base material, a painted base material, or a mortar T base material, it is necessary to apply a smoothing treatment to suppress the fuzz on the surface, or apply a cloth paste. It is necessary to perform a surface treatment to improve water absorption to prevent water in the adhesive or coating material from penetrating into the fiberboard.

In particular, when used as a base material for interior and exterior walls, stronger nail holding power and other features can be used to increase the strength of the wall.
It is desired to provide fiberboard with superior properties and water resistance without sacrificing its advantages.

The present invention has been developed in view of the above, and includes applying a composition liquid for forming a synthetic resin foam to the surface layer of a fiberboard, and then reacting the composition liquid while pressing the surface layer. The composition liquid is permeated into the surface layer of the fiberboard by foaming pressure to form a dense fiber-resin foam composite layer, which improves surface hardness IW and nail holding power.

Not only the mechanical properties such as bending strength, but also the water resistance and water absorption of Table 1 Yn are improved, and a surface-reinforced fiberboard with a smooth surface can be obtained. Therefore, it can be used as a cloth base material, mortar base material, etc. It is an object of the present invention to provide a method for manufacturing a surface layer reinforced fiberboard that can be used not only as a base material for interior and exterior walls or as a substrate for decorative laminates, but also for a wide range of other uses.

Hereinafter, the present invention will be described in detail. The fiberboard used in the present invention includes wood fiberboard with medium to low specific gravity such as soft fiberboard,
There are mineral fiberboards made of rock wool, slack wool, etc.

In addition, the composition liquid for forming a synthetic resin foam used in the present invention is
A synthetic resin such as styrene resin, acrylic resin, phenolic resin, or urea resin mixed with a blowing agent that generates decomposed gas when heated, for example, 100 parts by weight of phenol resin and 3 to 5 parts of toluene/sulfonyl hydrazide as a blowing agent. There are foamable synthetic resin liquids containing parts by weight.

In addition, in the case of urethane resin or ebogishi resin foam, for example, urethane resin foam, 100 parts by weight of tolylene diyrananate and 105 parts by weight of polyol are used.
A foaming agent such as a catalyst and water is added to parts by weight.

Then, the composition liquid as described above is applied to the fiberboard surface.
Thereafter, if necessary, it is pressed down with a roller or the like to impregnate the surface layer of the fiberboard.

Next, the impregnated fiberboard is pressed with a pressing device such as a flat plate press to cause the composition liquid to react and foam. In particular, in the case of a composition that foams when heated, heating and pressing is performed at a temperature higher than the decomposition temperature of the foaming agent.

Here, since the surface layer of the fiberboard is pressed by a smooth plate of a flat press, the synthetic resin foam that is formed penetrates inward from the surface of the fiberboard due to the foaming pressure.
Since it is formed so as to substantially fill the inter-fiber voids in the surface layer of the fiberboard, a dense fiber-synthetic resin foam composite layer is formed in the surface layer of the fiberboard. In addition, when using a composition liquid for forming a synthetic resin such as urethane resin foam, it is easy to sink into the fiberboard and there is no need to press it under heating in the trench, so the fibers can be applied to the surface layer of the fiberboard. There is an advantage that a composite layer of synthetic resin foam can be formed easily and with high production efficiency.

The surface-reinforced fiberboard obtained in this manner has a fiber-synthetic resin foam composite layer formed on the fiber surface layer. In addition, the mechanical properties such as surface hardness, nail holding force, bending strength, etc., as well as the water resistance and water absorption of the surface have been significantly improved, and the surface is smooth, so conventional smoothing and surface treatment are not required. It can be used as a base material for interior and exterior walls such as cloth base material 5 mortar base material, a substrate for decorative laminates, and a wide range of other construction materials.

As described above, according to the present invention, the surface layer reinforcement is excellent in mechanical properties, water resistance, water absorption, etc. without requiring smoothing or surface treatment, and is particularly suitable for base materials for interior and exterior walls and substrates for decorative laminates. It is possible to provide fiberboard.

Claims (2)

[Claims] (1) After applying a composition liquid for forming a synthetic resin foam to the surface layer of the fiberboard, by reacting the composition liquid described in "2" while pressing the surface layer, the dense outer fibers are applied to the surface layer of the fiberboard.
A method for manufacturing a surface reinforced fiberboard, comprising: forming a composite layer of resin foam. (2) The method for manufacturing a surface layer reinforced fiberboard according to claim (1), wherein the surface layer portion is pressed in a heated state.