JPH0418540B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a wood-cement decorative material whose surface is formed into a dense decorative layer, which is used for finishing the exterior walls of houses.

(Prior art and its problems) Wood cement boards are formed using relatively rough pieces of wood, so when the wood cement board is molded, it is compressed by a mold material, and even after it hardens, there are voids on the surface due to the overlapping pieces of wood. A large number of blemishes occur, making it impossible to obtain a detailed cosmetic surface.

For this reason, when manufacturing wood cement boards,
Alternatively, a method has been proposed in which after forming a wood cement board, a decorative layer is applied by changing the composition of the base material of the wood cement board and the surface layer layered on the surface of the base material. Addition of cement mixed with fibrous substances and fibrous materials as a surface layer is practiced.

However, according to this method, the adhesion between the base material and the decorative layer is poor due to the weak adhesive strength between the cement and the wood chips. External forces caused peeling and cracking of the decorative layer, and the peeling easily occurred after about 100 cycles using a weather meter, resulting in poor durability.

In order to improve these drawbacks, methods for increasing adhesion to the base material include, for example, mixing cationic emulsion resins such as acrylic esters and vinyl acetate polymers into aggregates such as pearlite, or adding cationic emulsion resins to the above resins. There is a method of forming a decorative layer by applying a resin-containing mortar composition emulsified with a surfactant such as benzenesulfonic acid to a base material, but when the above emulsion is mixed, when the decorative layer dries, the particles of the emulsion are fused together to form a continuous film, so if it is applied to the surface of an uncured base material and simultaneously molded, the film prevents the evaporation of the water contained in the base material, causing the cement components in the base material to evaporate. However, it has the disadvantage that it causes poor curing and cannot be molded simultaneously with the base material.

In addition, such film-forming emulsions tend to warp due to shrinkage force acting on the film formation, and especially when applied along the surface of a base material with a three-dimensional uneven decorative surface, the surface area is large. As a result, warping due to shrinkage was significant and dimensional stability was poor.

(Object of the Invention) The present invention was made in view of the above-mentioned drawbacks and problems, and is a hydraulic inorganic material containing an ethylene vinyl acetate emulsion emulsified with polyvinyl alcohol as a protective colloid layer on the surface of a wood cement board. By integrally providing a decorative layer made of a hardened material, it has a dense decorative layer that has strong adhesion to the base material, the wood cement board, and does not crack due to peeling or impact, and is resistant to warping or twisting. To provide a wood-cement-based decorative material that does not occur and can be manufactured efficiently.

(Structure of the Invention) In order to achieve the above object, the present invention provides a cosmetic comprising a hardened body of a hydraulic inorganic material containing an ethylene vinyl acetate emulsion emulsified with polyvinyl alcohol as a protective colloid layer on the surface of a wood cement board. It is characterized by having an integral layer, and is made of polyvinyl alcohol (hereinafter referred to as PVA).
Adhesive properties of ethylene vinyl acetate (hereinafter referred to as EVA) obtained by emulsifying EVA as a protective colloid layer.
Provides a wood cement-based decorative material that has a dense surface decorative layer with excellent cosmetic properties, impact resistance, dimensional stability, and productivity due to its fluidity, flexibility, and non-film-forming properties when drying. It is.

To explain the present invention in more detail according to an example of its manufacturing procedure, first, 100 parts by weight of small wood chips, 200 to 300 parts by weight of Portland cement, and 100 to 200 parts by weight of water are uniformly kneaded and dropped onto a patch plate. This forms a pine of approximately equal thickness.

Note that it is desirable to pre-press this mat in order to make it easier to handle.

Next, a paste-like coating material having the following composition is uniformly poured onto a suitable mold material.

Cement, gypsum, etc.; 100 parts by weight Perlite, charcoal, silica sand, asbestos, synthetic fiber, wood flour; 10 to 70 parts by weight EVA emulsified with PVA; 5 to 50 parts by weight Emulsion (solid content) Water; 30 to 70 parts by weight Part by Weight The thickness of this coating material can be adjusted by adjusting the amount of aggregate such as pearlite or charcoal mixed in, and is preferably several mm thick.

In addition, the PVA emulsified in the above coating material
The proportion of EVA emulsion used is preferably 5 parts by weight or more per 100 parts by weight of cement in order to improve the fluidity of hydraulic inorganic materials such as cement and the adhesion to the wood cement mat, which is the base material. From the viewpoint of surface hardness and fire resistance, it is desirable that the amount is 50 parts by weight or less.

Next, the mat is placed on the coating material that has been poured onto the mold material, and is pressed using a suitable pressing device. This compaction is to bring the coating material into close contact with the surface layer of the mat, and it is desirable to perform the compaction to such an extent that the cement in the mat hardens and no spring back occurs.

This compaction time is about 24 hours when Portland cement is used as the pine composition.

In this way, when applying the coating material to the pine surface, the EVA emulsion emulsified with PVA has excellent alkali resistance and adhesive properties, and also contains no components that inhibit the hardening of hydraulic binders such as cement. Since the cement on the surface of the pine does not harden properly, the adhesion and bonding between the cement component of the pine and the wood chips becomes strong, forming a decorative surface layer that does not peel off. Since the emulsion has excellent flexibility, cracks in the surface decorative layer due to external forces such as impacts are prevented, and a wood-cement decorative material with excellent durability can be obtained.

Furthermore, since EVA emulsion has a relatively large particle size and PVA is interposed between the EVA particles, the particles do not completely fuse with each other and the interface between the particles remains, allowing water and steam to escape. In order to prevent the evaporation of excess water from the pine during curing even after the surface layer hardens, the cement in the base material hardens quickly, and due to the presence of PVA, the EVA Since no film is formed, there is no shrinkage of the decorative layer during or after drying, and the occurrence of warping or twisting is prevented.

After the compaction process, the pressure is released and the wood cement board is removed from the form and left to cure indoors to evaporate excess moisture.

In the above process, the mat was formed in advance by preliminary pressing, but this mat-forming step was omitted and a mixture of small wood pieces, cement, and water was mixed to an appropriate thickness on the coating material poured onto the mold material. Furthermore, if the coating material, matte, and coating material are sequentially laminated between the upper and lower mold materials, and then the mold materials are compressed and hardened, a wood-cement-based decorative material with a decorative layer on the front and back surfaces can be created. wood is obtained.

Alternatively, an embossed pattern may be simultaneously formed on the pine surface layer and the coating material layer by using a mold material with an uneven pattern such as a stone grain or wood grain line pattern engraved on the mold surface.
In this case, the coating material layer mixed with PVA emulsion EVA has good fluidity and can faithfully reproduce the pattern of the mold material, so even fine uneven patterns can be easily imprinted and a fine and beautiful decorative layer can be applied. be able to.

Furthermore, if the cement component in the pine is pressed and molded with a mold material before it is completely hardened, the surface layer of the pine can be molded at the same time and a deep uneven pattern can be formed.
It is possible to form a decorative surface with a three-dimensional effect.

The wood cement-based decorative material obtained in this way is made of PVA, which is highly hydrophilic between the emulsion particles in the decorative layer.
Because EVA does not form a film, there is almost no shrinkage stress, there is no warpage, and it has excellent dimensional stability. The hydrophilicity of the PVA causes a so-called wetting phenomenon, resulting in good adhesion with other paints.

Next, specific examples of the present invention will be shown.

(Example) A coating material having the following composition was applied at 850 g/m ² with a mortar gun onto an FRP template having a woodgrain-shaped uneven pattern engraved on the mold surface.

Portland cement 100 parts by weight Perlite 10 〃 Ethylene vinyl acetate emulsion emulsified with polyvinyl alcohol 10 〃 (Solid content) Water 50 〃 Next Wood chips (flake form) 100 parts by weight Portland cement 220 parts by weight Water 160 parts by weight. A kneaded material consisting of the following was deposited to an appropriate thickness on the coating material layer, and then pressed for 24 hours to harden.

The thus obtained wood-cement-based decorative composite has a decorative layer made of the hardened coating material integrated onto the surface of the wood-cement board base material, resulting in a dense surface and problems such as poor hardening and warping of the cement in the base material. There was no occurrence of any scratches, and the surface was beautiful, with the unevenness of the wood grain pattern of the molded material faithfully reproduced.

Next, we applied a solvent-based white paint containing a mixture of acrylic resin and titanium oxide to the decorative surface of this wood-based cement-based decorative material by spray to create an exterior material. Even in the meter test, no peeling of the surface layer occurred and the material had excellent weather resistance.

(Effects of the Invention) As described above, according to the wood cement-based decorative material of the present invention, a coating material is formed by blending an EVA emulsion emulsified with PVA as a protective colloid layer, a hydraulic inorganic substance, and water on the surface of wood cement. Since the decorative layer made of hardened material is integrally provided,
EVA emulsion emulsified with PVA exhibits good adhesion performance to both cement and wood chips, making it possible to obtain a wood-cement decorative material that firmly adheres the decorative layer and does not cause peeling.

Furthermore, the surface layer mixed with the above EVA emulsion has excellent flexibility, which prevents cracks from occurring due to impacts on the surface decorative layer.Furthermore, since it has a relatively large particle size, it can be applied thickly to the surface of the base material. Even if a three-dimensional makeup layer is formed, the particles within the makeup layer do not completely fuse with each other and the interface between the particles remains, which forms a passage for water and steam to pass through and prevents curing. The cement hardens quickly without interfering with the evaporation of excess water from the pine during drying, allowing for efficient production, and since no film is formed, there is no shrinkage during or after drying, and dimensional stability with no warping or twisting. It is possible to obtain a wood cement-based decorative material with excellent properties.

In addition, the decorative layer is dense and can be easily imprinted even with a fine uneven pattern, making it possible to apply a fine and beautiful decorative layer, and since PVA, which is highly hydrophilic, is interposed between the EVA emulsion particles, the decorative layer is When the surface is further finished by painting, etc., a so-called wetting phenomenon occurs, and adhesion with other paints is good, and there is no uneven coloring caused by painting.

Claims (1)

[Scope of Claims] 1. A decorative layer made of a cured product of a coating material made by blending an ethylene vinyl acetate emulsion emulsified with polyvinyl alcohol as a protective colloid layer, a hydraulic inorganic substance, and water on the surface of a wood cement board. A wood-based cement-based decorative material. 2. The wood cement-based decorative material according to claim 1, wherein the surface layer of the wood cement board is formed into an uneven surface, and a decorative layer is integrally provided along the uneven surface.