JPS6020354B2 - Decorative board manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the production of decorative laminates that can be used as roofing materials, interior and exterior materials for buildings, etc., and more specifically, a method for manufacturing decorative laminates with excellent weather resistance with high productivity. Regarding.

Asbestos-cement boards have traditionally been used as roofing materials, interior and exterior walls of buildings, etc.

Initially, asbestos cement boards were used without any coloring or other cosmetics, but synthetic resin paints and synthetic resin emulsion paints have come to be applied to them for aesthetic purposes and to protect the boards themselves. However, such painting must be carried out after the asbestos cement board has cured, paying close attention to the water content of the board, and even if painting is done with due care, efflorescence may be observed or discoloration may occur. Defects such as fading and, in some cases, blistering or peeling of the paint film may be observed.
Subsequently, in the manufacturing process of asbestos cement boards, a method of creating a colored layer on the surface layer of the raw board or a method of coloring the entire raw board was adopted, but only a dull surface could be obtained, and it was difficult to achieve any desired gloss. It has been recognized that a colored surface cannot be obtained, and that the colored layer weathers quickly and lacks weather resistance.

An improvement to this method is to pressure-form an asbestos-cement board with a colored layer on the surface, cure it thoroughly, and then paint it with organic solvent-based or emulsion-based synthetic resin paint, mainly transparent paint. reached.

Even with these methods, defects may be observed in the adhesion, weather resistance, and properties of the paint film, and in particular, transparent paint films made from synthetic resin emulsions tend to disappear. I have not reached the point where I am satisfied. Furthermore, when painting, the asbestos cement board must be sufficiently cured, and sufficient attention must be paid to the moisture contained in the board. As a result, the original plate for painting must be strictly controlled, resulting in a lack of productivity. At the same time, it is necessary to control the coating thickness in order to guarantee weather resistance, etc., and quality assurance becomes difficult in the sense of protecting the plate with the coating, especially when the plate has an uneven embossed pattern. The inventors of the present invention have completed the present invention as a result of intensive research in view of the above-mentioned actual situation. It is an object of the present invention to provide a method for manufacturing a decorative board having excellent physical properties as a material etc. with increased productivity and easy management.

That is, the gist of the present invention is to form an asbestos cement raw plate by forming a colored layer on the surface layer, and after molding, apply an ultraviolet curable transparent paint and irradiate it with ultraviolet rays to form a cured transparent coating,
This method consists in a method for manufacturing a decorative board, which is characterized by curing after a certain period of time.

In carrying out the present invention, conventionally known methods may be used up to the step of producing an asbestos cement raw plate. That is, the base layer may be made of cement, asbestos, water, a silicic acid admixture, an organic fiber material, etc. as required, and the colored layer forming the surface layer may be a mixture of the base layer raw materials and colored pigments. It goes without saying that white cement can be used as the raw material for the colored layer, but it is also recommended to add styrene-butadiene synthetic rubber latex in some cases. The raw materials are selected and treated as necessary, such as asbestos delineation, and raw materials are weighed and mixed to produce a green plate with the colored layer as the surface layer.

The method may be any method such as a hatchet method, a Loch method, or a dry method. The thickness of the colored layer is preferably 0.2 h/m or more, preferably 0.3 h/m or more. Then, pressure molding is performed using a hydraulic press, hydraulic press, roll press, etc.

At this time, necessary embossing and waterway formation are performed when used as roofing material. According to the conventionally known method, the material is then cut and the process proceeds to a curing process, but in the present invention, if necessary, a painting process is employed after cutting and before curing.

The paint used in the painting process of the present invention may be an ultraviolet curable transparent paint that has excellent physical properties of the paint film, and it may be a paint that can form a colorless transparent film or a paint that can form a colored transparent film. It's okay.

In the present invention, a coating material that contains a reactive copolymer, a photopolymerizable compound, and a photopolymerization initiator as essential components and is cured by irradiation with ultraviolet light is referred to as an ultraviolet curable coating material. If necessary, organic solvents, inorganic coloring pigments, organic coloring pigments, and the like may be added as long as the transparency of the coating film can be observed. The UV-curable paint that can be preferably used in the present invention is a photopolymerizable polymer obtained by reacting a photopolymerizable monomer that undergoes an addition reaction with the functional group of an acrylic copolymer, a photopolymerizable compound, and a photopolymerizable compound. This is a paint that contains a polymerization initiator as an essential component. In the present invention, by applying the ultraviolet curing paint to the asbestos cement board before curing,
To obtain an IQ-shaped board which is excellent in durability, aesthetic appearance, etc. and can be used as a bag material inside and outside buildings, a roof material, etc.

Applying UV-curable paint after curing not only complicates the production process, but also causes the paint to be absorbed due to the porosity of the substrate, penetrate into the board, and undergo a curing reaction when exposed to UV light. This cannot be avoided as there is a risk that some areas will not occur, resulting in peeling of the paint film or a paint film lacking in durability.

According to the present invention, the water contained in the raw plank before curing adequately prevents the penetration of the paint into the board, and the curing reaction progresses easily by irradiation with ultraviolet rays, resulting in a clear coating with excellent adhesion. It can form the waist.

After the coating film is formed, it can be cured by any method such as wet curing or autoclave curing to form a product.

Examples and comparative examples are given below for a more detailed understanding of the present invention.

It goes without saying that the present invention is not limited to the following examples. Example 1 Voltland cement and asbestos (station) by weight 6
White Bortland cement, asbestos (arc) and chromium oxide (green inorganic pigment) are used in a ratio of 5:35 as raw materials for the colored layer forming the surface layer.
A ratio of 5:35:5 was used.

The asbestos is mixed with a sekisen machine, the raw materials are mixed with a dry mixer, then 7 times the amount of water is added with a wet mixer, and the slurry is further mixed with a chest, and this slurry is sent to a round silk wet machine. Built.

These are rolled and cut with a making roll so that the colored layer forms the surface layer to make a flat raw original plate, and the weight is 100kg/
Embossed patterns were added to the shape of the roof material using the pressure of the swimming process. The thickness of the plate is 9h/m, and the depth of the embossing is 0.
．． It is 9h/m. Next, a photopolymerizable copolymer was obtained by reacting an ethyl acrylate-acrylic acid copolymer with glycidyl methacrylate, and trimethylolpropane triacrylate was used as a photopolymerizable compound and penzoin methyl ether was used as a photopolymerization initiator. An ultraviolet curable paint made by adding the above was applied by electrostatic spraying, and ultraviolet rays were irradiated onto the surface of the sand to form a transparent coating film approximately 10 mm thick. Next, the first curing was performed at 360 degrees (6 hours at 6100 degrees), and the second curing was left in a warehouse for one week to obtain a decorative board.

It was found that the physical properties of this Iq side plate were excellent as shown in Taiichi 1.

We found that there were no manufacturing processes that required special management, such as moisture management for painting the boards, and that we were pleased with the productivity.

Comparative Example 1 Same as Example 1, the thickness of the molding knife was 0/m, the depth of the emboss was 0. Shoes/m raw plank was first cured at 360 degrees (6
After leaving it in a warehouse for one week for secondary curing, the same ultraviolet curable paint used in Example 1 was electrostatically sprayed, and ultraviolet rays were irradiated for 1 hour to form a transparent coating. was formed.

The physical properties of this decorative board were as shown in Table 1, and it was judged that it could not be put to practical use. Table 1 *1 A 10 q reap peel test was performed on the squares using a knife cut with a spacing of 2 skins/skin, and the remaining squares/100 were measured.

*2 Water immersion for 2 hours *3 2 hours in a wet box with relative humidity pseudo% and temperature 5-0 *4
Sunshine Weatherometer: 240 hours *5 As of 3 months of outdoor exposure

Claims (1)

[Claims] 1. A colored layer is formed on the surface layer to produce an asbestos cement raw plate, and after molding, an ultraviolet curable transparent paint is applied and ultraviolet rays are irradiated to form a hardened transparent coating, followed by curing. A manufacturing method for decorative laminates.