JPH0362477B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD The present invention relates to an inorganic decorative board, and particularly to a method for manufacturing an inorganic decorative board that is used for exteriors and has excellent durability and cosmetic properties. Conventional technology and its problems Conventionally, inorganic decorative boards with patterns used for exteriors, etc. are those in which a pattern is applied by printing a coloring agent on the surface of an inorganic base material, and a synthetic resin clear coat layer is formed. However, when used for a long period of time, the colored layer and clear coat layer deteriorated due to ultraviolet rays, etc., resulting in a marked deterioration in appearance and poor durability. For this reason, as a clear coat layer with excellent durability, for example, a clear coat layer made of an inorganic composition mainly containing a water-soluble alkali metal silicate described in JP-A-50-54620 can be used as a clear coat layer for printing. It has been proposed to cover the printed pattern to improve durability, but the adhesion with the undercoat film and colored layer is poor, causing cracks in the printed pattern, and the clear coat located on the printed pattern There was a problem that lifting occurred in the layers and the cosmetic properties were poor. On the other hand, in recent years, inorganic paints that use metal alkoxide as a binder have been developed. There was a problem that poor adhesion of the coating layer was likely to occur. Composition of the Invention In view of the above-mentioned problems, the present inventor conducted extensive research into improving the durability and cosmetic properties of inorganic decorative boards, and as a result, discovered that a clear coat layer and a coloring agent are interrelated with each other. We found the optimal conditions for the combination of the following and completed an inorganic decorative board with excellent durability and cosmetic properties. That is, the gist of the present invention is to provide an inorganic base material, an undercoat film formed on the surface thereof, a colored layer partially laminated on the surface of the undercoat film, and a clear coat covering at least the colored layer. In an inorganic decorative board consisting of a layer, an undercoat film is formed of a synthetic resin, and the colored layer has a solubility parameter of 12.
An inorganic decorative board formed of a non-aqueous coloring agent using the following solvent, and characterized in that the clear coat layer is made of an inorganic paint containing a metal alkoxide represented by the general formula M(OR)n as a binder. It is in the manufacturing method. Examples of inorganic base materials include asbestos slate boards, asbestos calcium silicate boards, and gypsum slag boards.There are no particular restrictions on their specific gravity, but inorganic base materials with a specific gravity of 1.3 or less are recommended to prevent uneven suction of the undercoat paint. However, in order to reinforce the surface, it is preferable to apply a sealer treatment in advance. Examples of the sealer include urethane, epoxy, and acrylic resin. The undercoat film hides the pores of the porous inorganic base material, prevents uneven suction of the non-aqueous colorant described below and uneven coloring, and coats the inorganic base material to cover the metal used in the clear coat layer described below. This prevents curing inhibition of inorganic paints that use alkoxide as a binder. Examples of the binder for the undercoat paint that forms the undercoat film include unsaturated polyester, polyester acrylate, epoxy acrylate, and urethane acrylate. As a method for applying the undercoat paint, known methods such as spraying, application using a roll coater, or dipping can be employed. A non-aqueous colorant using a solvent with a solubility parameter of 12 or less that forms a colored layer has excellent adhesion to the undercoat film, and uses a resin or a metal alkoxide described below as a binder for the colorant, and inorganic pigment or There is one in which organic pigments are mixed and stirred, and then a solvent, a co-solvent, and a diluent are appropriately added and dispersed. The solubility parameter is a measure of the dissolving power used to estimate the solubility of a solvent in a resin, and thermodynamically corresponds to the square root of molecular cohesive energy. The solubility parameter can be determined by various methods, but for example, when it is determined from the latent heat of vaporization, it can be determined from the following formula. Formula: δ ² = d/M (ΔHv-R・T) where δ is the solubility parameter, d is the density (g/ml), M is the molecular weight (g/mol), T is the absolute temperature (K), ΔHv is the latent heat of vaporization (cal/
mol), R is the gas molecule constant (1.986 cal/mol). Further, the solubility parameter can be approximately determined by determining whether a substance with a known solubility parameter δ ₁ can dissolve a substance with an unknown solubility parameter δ ₂ or not. Examples of resins used in the binder for colorants include cellulose, vinyl chloride, phenol, urethane, epoxy, alkyd, rubber, etc. that are compatible with solvents having a solubility parameter of 12 or less. Examples of inorganic pigments include titanium white,
Examples include carbon black, chromium-based pigments, and iron oxide-based pigments. Examples of organic pigments include azo compound-based and phthalocyaniline-based pigments. Solvents, co-solvents, and diluents include alcohols, ethers, ketones, and solubility parameters of 12 or less.
Aldehydes, such as butanol, xylene, methyl cellosolve, diethyl ether,
Examples include benzene and methyl ethyl ketone. In addition, the solubility parameter was set to 12 or less because
Experiments have shown that if the solubility parameter exceeds 12, the compatibility with the undercoat and clear coat decreases, and the adhesion is insufficient, resulting in swelling or peeling with water, etc., and lack of durability. This is because it was done. Furthermore, if necessary, a plasticizer and a surfactant may be mixed with the non-aqueous colorant. Examples of methods for coloring with the non-aqueous colorant include screen printing, flexible printing, offset printing, gravure printing, letterpress printing, intaglio printing, sputtering, and the like. An inorganic paint using a metal alkoxide represented by the formula M(OR)n as a binder for a clear coat layer (hereinafter referred to as "metal alkoxide-based inorganic paint")
Specifically, M is silicon, titanium, aluminum, strontium, barium, lead, tin, lanthanum, zirconium, or iron, R is an alkyl group such as methyl, ethyl, propyl, butyl, pentyl, etc., and n is 1 to It is expressed as an integer of 4. In addition, the metal alkoxide-based inorganic paint may contain a metal oxide or a sulfide added thereto as a filler, if necessary. When a catalyst such as ammonia is added to the metal alkoxide-based inorganic paint, it undergoes hydrolysis at a heating temperature of room temperature to 180°C, preferably 70°C to 150°C, and is cured by a polycondensation reaction. Example 1 A white epoxy resin was applied to an inorganic base material consisting of an asbestos cement calcium silicate plate with a specific gravity of 1.6 and cured to obtain an undercoat film with a thickness of approximately 20 μm. A blue ethyl cellulose printing ink containing butanol as the main solvent was patterned by screen printing. After the pattern has dried, a metal alkoxide-based clear paint, which is a mixture of a silicon alkoxide-based main liquid and an ammonia-based auxiliary liquid, is applied to the inorganic base material, and this is held in a furnace at a temperature of 120°C for 10 minutes. Then heat and harden to a thickness of 5 to 20 μm.
A sample was obtained having a clear coat layer of . Example 2 Same as Example 1 except that instead of using the blue ethyl cellulose printing ink in Example 1, a red alkyd resin printing ink with a solubility parameter of 9.0 and xylene as the main solvent was used. A sample was obtained by performing the operation. Comparative Example 1 Instead of applying the silicon alkoxide-based clear paint in Example 1, a water-soluble alkali metal silicate-based clear paint (Sumitomo Chemical Co., Ltd.: Sumiceram PU5017) was applied in the same manner as in Example 1. death,
Heat this by holding it in a furnace at a temperature of 270℃ for 15 minutes.
A sample was obtained in the same manner as in Example 1, except that it was cured to obtain a clear coat layer with a thickness of 10 to 20 μm. Comparative Example 2 Instead of using the blue ethyl cellulose ink in Example 1, the solubility parameter
Except for the use of an acetyl-butylcellulose-based red paint based on ethanol with a solubility parameter of 12.7 and ethylene glycol with a solubility parameter of 14.2.
The same operation as in Example 1 was performed. Table 1 shows the results of experiments and observations for each sample obtained as described above.

[Table] From the above results, the clear coat layers of Examples 1 and 2 had better transparency and adhesion than the comparative example because no minute cracks or lifting occurred in the clear coat layers of Examples 1 and 2. Excellent in nature. In addition, since the colored patterns of Examples 1 and 2 did not exhibit any cracking or fading,
It was found that the sample had better durability and cosmetic properties than the comparative example. This is because most of the solvent in metal alkoxide paints is alcohol, and the rest is a small amount of water produced during the curing reaction, so if the colorant is water-based,
Not only is it easily attacked by solvents such as alcohol, but a portion of the colored part swells and dissolves due to the water generated during the curing reaction. This is thought to be because the surface layer of the colored layer is hard to be attacked, and even if the surface layer of the colored layer is attacked, it is only slight, and conversely, the adhesion is increased by the unevenness caused by the above-mentioned erosion. Effects of the Invention As is clear from the above explanation, the area appropriately colored with a non-aqueous colorant is covered with a clear coat layer that has good adhesion to the undercoat paint, so it is protected from rainwater, sunlight, etc. . Therefore, the colored portion is less likely to deteriorate over time, such as cracking or fading, and its durability is improved. In particular, since the colorant is a non-emission type, even if the metal alkoxide paint that forms the clear coat layer is applied to areas colored with a non-aqueous colorant, the colored area may swell due to the solvent of the metal alkoxide paint. , no blurring, and the non-aqueous colorant provides good adhesion to the clear coat layer.
Prevents lifting of the clear coat layer. As a result, in addition to the above-mentioned effects, it is possible to obtain an inorganic decorative board that maintains a beautiful and delicate pattern for a long period of time.

Claims (1)

[Claims] 1. An undercoat film made of synthetic resin is formed on the surface of an inorganic base material, and a colored layer is partially applied to the surface of this undercoat film with a non-aqueous colorant using a solvent with a solubility parameter of 12 or less. and form the undercoat film and the colored layer with the general formula: M(OR)n [wherein M is silicon, titanium, aluminum,
Zirconium, strontium, barium, lead,
tin, lanthanum, sodium or iron; R is an alkyl group having 1 to 10 carbon atoms; n is an integer of 1 to 4; ] A method for producing an inorganic decorative board, characterized in that it is coated with a clear coat layer made of an inorganic paint containing a metal alkoxide represented by the following as a binder.