JPH01164479A - Production of inorganic decorative sheet - Google Patents

Abstract

PURPOSE:To prevent the cracking and peeling of an inorg. paint film by adjusting the surface of an epoxy resin layer formed on an inorg. base material to 7-11pH and by coating the adjusted surface with inorg. paint contg. a specified metal alkoxide as a binder to form the paint film. CONSTITUTION:An epoxy resin layer is formed on the surface of an inorg. bale material and the surface of the resin layer is adjusted to 7-11pH. The adjusted surface is coated with inorg. paint contg. a metal alkoxide represented by a formula N(OR)n (where M is Si, Ti, Al, Zr, Sr, Ba, Pb, Sn, La, Na or Fe, R is 1-10C alkyl and n is an integer of 1-4) as a binder and the paint is cured to form a paint film as a surface layer. Thus, an inorg. decorative sheet is produced.

Description

DETAILED DESCRIPTION OF THE INVENTION Industrial Application The present invention relates to a method for producing an inorganic decorative board that can effectively produce an inorganic decorative board having good coating performance.

Conventional technology and its problems Traditionally, as a manufacturing method for inorganic decorative laminates, for example, the method of applying an inorganic paint to the surface of an inorganic base material has been widely used. , has been studied from the viewpoint of durability and scratch resistance.

However, when the paint is applied to the surface of an inorganic base material, the polycondensation reaction does not proceed due to the strong alkalinity of the base material (approximately PII+4), resulting in poor curing.

As a result, when used in locations with severe usage conditions, such as experimental booths and exterior wall materials, there is a problem in that cracks or discoloration may occur in some areas of the coating.

4 Mori ΔMM In view of the above-mentioned problems, the present inventor conducted intensive research on a method for manufacturing an inorganic decorative board to achieve excellent coating film performance. and (B), a method for manufacturing an inorganic decorative board that has good coating performance and has a large degree of freedom in manufacturing conditions by finding the optimal conditions for the combination of the inorganic base material and the inorganic paint forming the surface coating J10. I was able to complete it.

That is, the gist of the present invention is that after adjusting the coated surface of the inorganic base material through an epoxy resin layer to a PII of 7 to 11 degrees, preferably a pH of 7 to 8, the general formula 2M(OR)n (in the formula , 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, and n is an integer of 1 to 4. A method for producing an inorganic decorative board, which comprises applying a metal alkoxide-based inorganic paint containing a metal alkoxide as a binder and curing it to form a surface coating film.

Examples of the inorganic base material include calcium silicate board 1 asbestos cement calcium silicate board 1 asbestos slate slag gypsum board, pulp cement board, ALC, and the like.

The epoxy resin layer is formed by applying an epoxy resin to the surface of the inorganic base material. Examples of epoxy resins include amine-cured, polyamide-modified, and ester-modified ones; It may be a mixture of resin, urea resin, melamine resin, alkyd resin, etc. as appropriate.

As the method for applying the epoxy resin, for example, a coloring method using a roll coater, reverse coater, spray, etc. can be selected, and the coating amount is such that the coating thickness of the cured epoxy resin layer is 5 μm to 200 μm, preferably 20 μm.
A good amount is 80 μm. If it is less than 5 μm, the inorganic base material will be exposed and the PLI of the coated surface will be 12 or more, and the condensation polymerization reaction will not proceed even if the metal alkoxide-based inorganic paint is hydrolyzed due to the influence of the alkali component of the base material. On the other hand, if the thickness is 200 μm or more, the expansion and contraction of the undercoat film itself will affect the warping of the base material.

The epoxy resin starts a ring-opening polymerization reaction using an inorganic base as a catalyst, but according to the present invention, since the alkali component eluted from the inorganic base material acts as a catalyst, the curing reaction of the epoxy resin is accelerated, and the curing reaction is accelerated at room temperature. A three-dimensional network structure is formed at a temperature of 150°C to 150°C.

Therefore, there is an advantage that a strong and highly adhesive undercoat film can be formed on the surface of the inorganic base material.

On the other hand, the metal alkoxide-based inorganic paint may be a transparent paint made by dissolving the metal alkoxide alone in an alcohol solvent, and if necessary, pigments such as titanium oxide, iron oxide, clay, red lead, and chromium oxide may be added as appropriate. It may also be a colored paint that has been mixed with it.

As for the method of applying the metal alkoxide-based inorganic paint, any method similar to the above-mentioned method of applying the epoxy resin can be adopted, but it is better to divide the application process into multiple times and dry it to improve the surface coating film. Preferable for preventing discoloration and efflorescence.

The metal alkoxide-based inorganic paint may be applied continuously to the surface of the epoxy resin layer after the curing reaction or after the curing reaction is completed, but the surface temperature of the epoxy resin layer must be kept at 70°C or lower, preferably at 40°C or lower. It is better to apply after cooling. This is because when the surface temperature is set to 10° C. or lower, the scattering of alcohol, which is a solvent for metal alkoxide-based inorganic paints, decreases, making it difficult for whitening to occur on the paint film surface.

When a catalyst such as ammonia is added to the metal alkoxide-based inorganic paint, the temperature ranges from room temperature to 180°C, preferably 70°C.
Hydrolysis occurs by heating to 150° C. to 150° C., and hardening occurs through the polycondensation reaction shown below.

M (On)n 10nH20→~f(Oll)n+n
R(Oll)M(OII)n'MOn/2+n/,
■-1,0 When this metal alkoxide-based inorganic paint is applied, the alcohol, which is the solvent, causes damage to occur between the active groups such as 011 groups in the epoxy resin layer and the metal alkoxide-based inorganic paint. However, a polycondensation reaction occurs, and the adhesion between the epoxy resin layer and the metal alkoxide coating film improves.

In addition, if the alkaline component of the inorganic base material leaches into the metal alkoxide-based inorganic coating film through the epoxy coating film,
Since H is 11 or less, preferably P 1-17 to 8, the weak alkali component acts as a catalyst to accelerate the polycondensation reaction of the metal alkoxide-based inorganic paint, thereby increasing the polycondensation reaction.

Therefore, the adhesion between the epoxy resin layer and the metal alkoxide-based inorganic paint increases, and the metal alkoxide-based inorganic paint film itself is formed firmly, making it difficult for cracks and peeling to occur.

Example 1 After applying an epoxy resin paint to an asbestos cement calcium silicate board with a specific gravity of 1.5, it was cured by heating at a temperature of 120°C for 6 minutes to form an epoxy resin layer with a thickness of about 20 μm. I got a painted surface.

Then, after leaving it for 10 minutes and cooling it at room temperature to bring the surface temperature of the epoxy resin layer to 40°C, a metal alkoxide-based inorganic paint containing a silicon alkoxide-based main liquid and an ammonia-based auxiliary liquid was applied. , 20 at a temperature of 150℃
A sample having a surface coating film with a thickness of about 20 μm was obtained by heating for a minute to avoid curing.

Example 2 After forming an epoxy resin layer in the same manner as in Example 1, it was left to stand at room temperature for one day, and the other operations were the same as in Example 1 to obtain a sample.

Comparative Example 1 An acrylic urethane resin paint was used instead of the epoxy resin paint used in Example 1, and the surface to be coated was
A sample was obtained by carrying out the same operation as in Example 1 except that II 6 was used.

Comparative Example 2 Evokin was attached to the surface of the inorganic base material in Example 1 with tn!
Noacryl phthalate (D
After pasting and integrating the AP) sheets to obtain the coated surface of I) H6, the surface was roughened with Zand paper (240#), and the rest was coated with Noricon alkoxide-based inorganic paint in the same manner as in Example I. A sample with a surface coating film was obtained.

Various experiments were conducted on the samples obtained as described above. The measurement results are shown in Table 1.

Table 1 * Adhesion is the result of base rotisting with width (am) t0 base test is *Water resistance (1) is the result of visually observing the coating film after immersing it in water for 10 hours. shows.

*Water resistance (2) shows the results of a substrate test with a width lIIm on the sample related to water resistance (1) above.

As is clear from Table 1, when the adhesion of Example 1.2 and Comparative Example 1.2 was compared, Example 1.2
It was found that the coating film had superior adhesion.

Furthermore, in terms of water resistance (1) and (2), no change was observed in Examples 1 and 2 even after the immersion treatment, whereas in Comparative Example 1.
In No. 2, significant deterioration of coating film performance was observed.

From this, it was found that Example 1.2 had better water resistance than Comparative Example 1.2.

Effects As is clear from the above explanation, according to the present invention, the inorganic base material promotes the mutual curing reaction of the epoxy resin and the metal alkoxide-based inorganic paint, so the adhesion of the above-mentioned king is improved and the coating film is Peeling and cracking are less likely to occur, and coating performance is improved.

In particular, if two coats of metal alkoxide-based inorganic paint are applied with the alkaline component of the inorganic base material exuded through the epoxy resin layer formed on the inorganic base material, or with the active groups of the epoxy resin remaining, each In the curing reaction, the alkali component or active group acts as a catalyst, and rather improves the adhesion and strength of the three components.

As a result, even if there are variations in manufacturing conditions, variations in coating film performance are less likely to occur, which has the effect of increasing the degree of freedom in manufacturing conditions.

Claims (1)

[Claims] (1) After forming an epoxy resin layer on the surface of the inorganic base material and adjusting the pH of the surface to be coated to 7 to 11, 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, and n is an integer of 1 to 4. ) A method for producing an inorganic decorative board, which comprises applying a metal alkoxide-based inorganic paint having a metal alkoxide as a binder and curing it to form a surface coating film.