JP2002179951A - Inorganic coating material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inorganic coating material capable of forming a coating film which has high hydrophilicity and from which oily or fatty contaminants can be readily washed away. SOLUTION: The inorganic coating material is obtained by adding a metallic aluminum powder to an inorganic coating material containing an alkali metal silicate. The metallic aluminum powder is added preferably in an amount of 0.2-35 wt.% based on the solids of the alkali metal silicate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inorganic paint such as a water glass-based paint, and more particularly to an inorganic paint for forming a coating film to which stains, especially oil-based stains, are difficult to adhere.

[0002]

It is well known that when water glass is applied to a substrate and baked, a beautiful glassy coating film is formed on the surface of the substrate.

[0003] It is known to add a metal phosphate, zinc oxide, zirconium oxide, or the like to a water glass-based paint in order to increase the water resistance of a coating film formed by the water glass or to prevent the occurrence of white spots. It is.

[0004]

The conventional water glass coating film has a problem that it is difficult to remove even if it is washed with water when oil-based dirt adheres.

[0005] An object of the present invention is to provide an inorganic paint for forming a coating film having high hydrophilicity and capable of easily removing oil-based stains with water.

[0006]

The inorganic coating material of the present invention comprises:
An inorganic paint containing an alkali metal silicate, wherein a metal aluminum powder is added.

[0007] As a result of a test, it was confirmed that the coating film formed by such an inorganic coating material had remarkably high hydrophilicity. Even if the coating film with high hydrophilicity adheres oil-based dirt,
This dirt is easily washed off by the water. Therefore, when this coating film is formed on an exterior material, when the exterior material is hit with rain, dirt flows down, and the exterior material is kept clean for a long time. Further, when this coating film is formed on an exterior material or an interior material, even if dirt is attached, it can be easily removed by washing or wiping with water.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The alkali metal silicate constituting the inorganic paint of the present invention may be any of sodium-based, potassium-based, lithium-based and the like. Is preferred, and it is most preferable to use a commercially available water glass.

The metal aluminum powder to be added to the alkali metal silicate has a particle size of 500 μm or less, especially 100 μm.
m or less are preferred. It is preferable to sufficiently stir the inorganic coating so that at least a part of the added metal aluminum powder is dissolved, and it is particularly preferable to stir while heating to about 60 to 80 ° C.

The addition amount of the metal aluminum powder is preferably 0.2 to 35% by weight, more preferably 0.5 to 35% by weight, based on the solid content of the alkali metal silicate. By adding 0.2% by weight or more, especially 0.5% by weight or more of metal aluminum powder, the hydrophilicity of the coating film is significantly increased. If the amount of the metal aluminum powder exceeds 35% by weight, the coating film becomes coarse. The effect of improving the hydrophilicity becomes sufficiently high when about 0.5% by weight of metallic aluminum powder is added.
Since the hydrophilicity is not further improved even if the addition amount exceeds the weight%, the addition amount of the metal aluminum powder is preferably 5% by weight or less, especially 1% by weight or less.

A part of the added metal aluminum powder, probably about 30% by weight of the alkali metal silicate solids, is dissolved in the inorganic paint. It is presumed that the dissolved and ionized aluminum is taken into the alkali metal silicate to form the skeleton structure of the aluminosilicate.

A surfactant may be added in order to disperse the metal aluminum powder that has not been completely dissolved in the inorganic coating material. Further, an antifoaming agent may be added to eliminate foaming caused by the addition of a surfactant. The addition amount of the surfactant is preferably 100% by weight or less, particularly preferably 0.1 to 50% by weight of the metal aluminum powder. The amount of the defoamer added is 100% by weight or less of the surfactant, particularly 50 to 100% by weight.
Is preferred.

The inorganic coating material of the present invention may contain a metal phosphate or a curing agent such as zinc oxide, magnesium oxide or zirconium oxide, if necessary.

Further, it may contain a filler such as silica stone, and may contain various pigments.

The inorganic coating material of the present invention is added with water as required, and has a viscosity that facilitates application. The amount of water to be added may be determined by appropriate experimentation so as to have an appropriate viscosity.

This inorganic paint is sprayed, brushed,
Rolled, applied to the surface of the substrate by various methods such as dipping, and then baked at about 180 to 280 ° C,
Form a coating.

Although the thickness of the coating film is optional, it is preferably about 0.02 to 3 mm when used as a building material.

The inorganic coating material of the present invention can be applied to various types of base materials such as metal panels, resin panels, and ceramic tiles, in addition to cement bases, calcium silicate bases, and the like.

When the inorganic coating material is applied to the base material, a means such as applying a primer treatment to the base material surface or forming a base layer for improving the compatibility between the coating film and the base material is adopted. You may.

[0020]

EXPERIMENTAL EXAMPLE 1 (Examples 1 to 9, Comparative Examples 1 and 2) 100 parts by weight of water were added to 100 parts by weight of commercially available soda water glass (concentration: 40% by weight), and the ratio shown in Table 1 (water glass) (Weight% based on the solid content) and a metal aluminum powder having an average particle size of 50 µm were added, and the mixture was stirred at 80 ° C for 24 hours. Thereafter, a surfactant (Chukyo Yushi D-305 (5% solution))
And defoamer (San Nopco Nopco 8034 (5%
1) was added by 1 part by weight, and the mixture was stirred for 15 minutes.

The thus prepared inorganic paint is used for 80
Commercially available window glass plate (26 × 76 × 1.5 m
m) was air-sprayed and dried to form a coating film. This coating film was heated in a 220 ° C. air bath for 1 hour to cure the coating film. The thickness of this coating was about 50 μm.

[Evaluation of Hydrophilicity 1] The water contact angle on the surface of the glass plate was measured to evaluate the hydrophilicity. The results are shown in Table 1 as Evaluation 1. [Hydrophilicity evaluation 2] The glass plate was stood upright at an inclination angle of 60 ° in a vertical position, and 0.5 cc of commercially available salad oil was dropped and attached to a position 25 mm from the upper end. Next, 500 cc of room temperature distilled water was poured at a flow rate of 10 cc / sec to the dropping portion of the salad oil.

Thereafter, the water contact angle near the center of the glass plate was measured to evaluate the hydrophilicity. Evaluation of the results in Table 1 2
As shown.

For comparison, as Comparative Example 1, the same evaluations 1 and 2 were carried out for an inorganic paint to which no metallic aluminum powder was added, and the results are shown in Table 1.

[0025]

[Table 1]

As shown in Evaluation 1 in Table 1, the addition of metallic aluminum powder reduces the water contact angle and increases the hydrophilicity. In addition, it is clear from Evaluation 2 that the salad oil easily flows off by washing with water due to its high hydrophilicity. In particular, it is clear from Table 1 that the addition amount of the metal aluminum powder of 0.2 to 35% by weight is suitable.

Experimental Example 2 (Examples 9 to 18, Comparative Example 3,
4) An inorganic paint was prepared in exactly the same manner as in Experimental Example 1 except that commercially available potassium water glass (concentration was the same as in Experimental Example 1; 40% by weight) was used instead of soda water glass, and a coating film was formed. Then, the same evaluations 1 and 2 were performed. Table 2 shows the results.

[0028]

[Table 2]

As shown in Table 2, even when potash water glass is used, the addition of metallic aluminum powder improves the hydrophilicity of the coating film, and it is particularly preferable to add 0.2 to 35% by weight of metallic aluminum powder. Is recognized.

[0030]

As described above, according to the inorganic coating material of the present invention, a coating film having a high hydrophilicity and capable of easily running off stains, particularly oil-based stains, can be formed.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Yukari Ichikawa 5-1-1 Koiehonmachi, Tokoname-shi, Aichi F-term in Inax Corporation (reference) 4J038 AA011 HA066 HA451 KA20 NA05 NA06

Claims (2)

[Claims] 1. An inorganic paint containing an alkali metal silicate, wherein a metal aluminum powder is added to the inorganic paint. 2. The method according to claim 1, wherein the addition amount of the metal aluminum powder is 0.2% of the solid content of the alkali metal silicate.
An inorganic paint characterized by being in an amount of about 35% by weight.