JPH0781096B2 - Method for imparting weather resistance to metallic materials - Google Patents

Description

The present invention relates to a method for imparting weather resistance to a metal material.

(Prior Art) In general, inorganic paints use water as a dispersion medium, so the stock solution itself is non-flammable. Water is easier to obtain than other solvents, it is hygienic to the human body, and environmental pollution such as air pollution. Furthermore, the cured coating has various advantages such as heat resistance, fire resistance, smokelessness, no generation of toxic gas during combustion, high hardness, and good wear resistance.

However, most of them have extremely poor moisture resistance, water resistance, and weather resistance, and therefore have the above-mentioned various features, but are actually very limited in terms of application. Especially in a high-humidity country such as Japan, even when the place of use is inside a building, its use is further restricted due to moisture during the rainy season, steam during rice cooking, and dew condensation due to heating. The current situation. Therefore, many reforming experiments have been attempted in order to improve the moisture resistance, water resistance and weather resistance of the film, but in reality, for coating using an alkali silicate as a binder, the moisture resistance and water resistance film due to carbonation of alkali are used. There is a drawback in that the pot life is restricted because it is a so-called separate type in which post-treatment is performed with phosphoric acid, ammonium phosphate, etc. in order to accelerate the conversion, or a curing agent such as an acid phosphate is added at the time of use.
In addition, in order to improve the performance of the coating, it is necessary to perform heating curing at about 200 ° C, but the fact is that it cannot be applied at all to coatings for buildings and large structures that cannot be heated curing.

On the other hand, in the case of using colloidal silica or alumina sol as a binder, they are used together with a high ratio of water-based binder due to poor film-forming property, and accordingly, although it is an inorganic coating agent, heat resistance, fire resistance, fire resistance, The feature of low smoke is inevitably reduced.

(Problems to be Solved by the Invention) An object of the present invention is to use an inorganic coating agent capable of giving a coating having high heat resistance, fire resistance, weather resistance, smokelessness, high hardness, and excellent water resistance, moisture resistance, and abrasion resistance. Another object of the present invention is to provide a method for imparting weather resistance to a metal material.

Another object of the present invention is to provide a method for imparting weather resistance to a metal material, which does not require post-treatment and uses an inorganic coating agent having a long pot life.

(Means for Solving the Problems) The present invention relates to a method for imparting weather resistance to a metal material, which is characterized in that a coating material A and a coating material B described below are laminated and coated on the metal material in this order.

Coating material A: (a) at least one selected from the group consisting of alkali silicates and colloidal silica, (b) titanium represented by the general formula M ₂ O.nTiO ₂ (M is an alkali metal, and n is 6 or 8). An inorganic coating material comprising at least one kind of acid-alkali and (c) zinc dust.

Coating material B: (a) at least one selected from the group consisting of alkali silicates and colloidal silica, and (b) represented by the general formula M ₂ O.nTiO ₂ (M is an alkali metal, n is 6 or 8) An inorganic coating material containing at least one alkali titanate.

In the present invention, at least one selected from the group of alkali silicates and colloidal silica is used as the component (a). Examples of the alkali silicate include sodium silicate, potassium silicate, lithium silicate, ammonium silicate, amine silicate and the like.

In the present invention, as the film forming auxiliary agent, the general formula M ₂ O · n of the component (b) is used.
At least one kind of alkali titanate represented by TiO ₂ (M is an alkali metal and n is 6 or 8) is used. In the formula, M represents an alkali metal such as Li, Na and K. The alkali titanate is preferably fibrous.

In the present invention, it is preferable to use about 1.4 to 70 parts by weight of the component (b) based on 100 parts by weight of the component (a).

In the present invention, as described above, the coating material A and the coating material B are laminated and coated on the metal material in this order, whereby water resistance further superior to that of each of the coating material A and the coating material B can be obtained. .

As described above, the inorganic coating agent of the present invention is heat resistant, fire resistant, weather resistant, smokeless, has a large hardness, and is capable of providing a coating excellent in water resistance, moisture resistance, and abrasion resistance, but such an effect is obtained. It is unique to the specific alkali titanate used in the present invention, and as will be apparent from the comparative example described below, titania fiber (Otsuka Chemical, trade name: Neutral Tesmo), fibrous 4
When potassium titanate and water-dispersed titanium oxide (Teikoku Kako, trade name JA-1, anatase type) were tested under the same composition and under the same conditions, the effect was remarkably inferior.

In the present invention, a small amount of a water-soluble or water-dispersible polymer, that is, polyvinyl alcohol, methyl cellulose, carboxymethyl cellulose soda, acrylic acid soda, acrylic acid ester emulsion, vinyl acetate emulsion, as well as a general coating agent, if necessary. It is possible to use ethylene-vinyl acetate emulsion and the like in combination, but it is desirable that the maximum amount is 10% by weight or less in terms of solid content, to the extent that the characteristics of the inorganic coating agent are not impaired. Since the coloring pigment is an inorganic coating agent, it is desirable to use a mineral pigment such as titanium oxide, zinc white, titanium yellow, red iron oxide, chromium oxide green, ultramarine, cadmium red, iron black, and the like. Which one is available.

As extender pigments, talc, mica, clay, silica, lime carbonate and the like can be used depending on the purpose.
Furthermore, when manufacturing a primer to be applied to iron products,
It is also possible to mix metallic zinc powder, mycasia iron oxide powder, water-dispersible aluminum foil powder and the like.
Further, special fillers such as glass microballoons and shirasu balloons, low melting point glazes (frit), etc. may be blended.

The alkali titanate used in the present invention has good water dispersibility in view of its chemical composition, but if necessary, a small amount of a wetting agent generally used for water-based paints (water-soluble and water-dispersible paints) may be added. It is possible, and if necessary, a small amount of a non-silicone type defoaming agent may be blended to defoam the undiluted solution as well as to eliminate the bubbles generated at the time of application.

If necessary, an antifreezing agent, a water repellent, a fungicide and the like may be appropriately added to improve the stability of the undiluted solution at low temperatures and the water repellency and antifungal property of the coating.

The production of the inorganic coating agent of the present invention may be carried out by an ordinary production method of water-based paint, and no special equipment is required. However, the container to be stored must be resistant to acid and corrosion such as stainless steel or FRP. It should be noted that the alkali titanate which is a film-forming auxiliary is preferably added before adding other pigments or extender pigments and once sufficiently dispersed using a high-speed stirrer such as a disper.

The inorganic coating agent of the present invention is preferably applied as an undiluted solution or, if necessary, diluted with about 5 to 15% by weight of water and diluted with an aqueous brush, roll brush, air spray, airless spray or the like. Also, dip coating is possible depending on the material to be coated.

The inorganic coating agent of the present invention is air-dried after application, but may be forcibly dried using hot air or the like if necessary.

Applications of the inorganic coating agent of the present invention include, for example, plasterboard, particle board, wood wool board, flexible board, asbestos slate, rock wool sound absorbing board, etc. non-combustible ceiling material water resistance, dewproofing, mildewproofing, smokeless coating, light weight bubbles Concrete, concrete, mortar,
Non-combustible wall material for bricks, etc. Water resistant, dewproof, mildewproof, smokeless, fireproof coating, fireproof for sielter, smokeless, nontoxic coating, boiler, chimney, heating device, heat exchanger, etc. Seawater resistant, acid resistant, corrosion resistant coating, concrete floor dustproof, solvent resistant, abrasion resistant, fire resistant coating, long-term decorative coating on apartment housing balconies such as mansion, high temperature anti-oxidation coating on carbon fiber products, backside when baking enamel ironware Examples include antioxidant coating and hard coating.

(Example) Below, a reference example, an example, and a comparative example are given and demonstrated.
The term "parts" means "parts by weight".

Reference Examples 1 to 10 Inorganic coating agents were prepared by mixing the components in the proportions (parts) shown in Table 1.

In Reference Examples 1-2 and 5-10, lithium silicate 45
(Nissan Kagaku) or Snowtex S (colloidal silica, Nissan Kagaku) and fibrous potassium 6-titanate or fibrous potassium 8-titanate were weighed in a polybeaker and dispersed with a small disper for about 30 minutes. In Reference Examples 3 to 4, other pigments and extender pigments were further added, and the mixture was kneaded for one day in a porcelain pot mill having a capacity of 1 to prepare. In Reference Examples 9 to 10, zinc dust was mixed at the time of use. KM of Reference Example 9
200L-1 was added during dispersion of the dispersion.

Titania fiber is Otsuka Chemical's neutral Tesmo, titanium white JA
-1 is talc LM, anatase type titanium oxide manufactured by Teikoku Kako
P is made by Tsuchiya Kaolin, Mica C1000 is made by Shiraishi Industry, Zinc dust is made by Hakusui Chemical, KM200L-1 is made by Shin-Etsu Chemical, Silicone emulsion, BYK-W is a defoaming agent by West Germany, BYK Marine Clot.

Comparative Examples 1 to 8 Inorganic coating agents were prepared in the same manner as in Reference Example except that the components shown in Table 2 were used.

Test Example 1 Each coating agent obtained in Reference Example and Comparative Example was applied with a brush to a 1 × 70 × 150 mm steel plate (JIS G3141SPCC-D), which was polished with sandpaper (# 180) and washed with trichlene, and was used indoors. After curing for 3 days, its properties were measured.
The results are shown in Tables 3-4.

In the table, the dryness is JIS K 5400, 5.8, the state of the dry film is the naked eye, the film thickness is the elcometer, the hardness is JIS K5400, 6.14, the adhesiveness is 1 mm × 100 scoring, cellophane tape peeling, the water resistance is 20 ° C. It was immersed in fresh water for 7 days, and the heat resistance was measured by heating at 400 ° C for 120 hours.

Example 1 Since the coating films of Reference Examples 1 to 4 showed rusting in the water resistance test, the above-mentioned steel sheet was coated with the primer of Reference Example 9 twice, and the topcoat of Reference Example 4 was coated twice. Was applied, and the composition was cured at room temperature for 3 days, and then its characteristics were measured. The results are shown in Table 5.

From Table 5, it can be seen that, in the case of Example, in combination with the primer, no rusting was observed even when applied to iron products, and it was a coating agent that was sufficiently practical.

Example 2 The same steel sheet as in Example 1 was coated with the primer of Reference Example 10 twice and the top coat of Reference Example 5 twice with a brush, and after curing at room temperature for 3 days, its characteristics were measured. The results are shown in Table 6.

Comparative Example 9 A coating film was obtained in the same manner as in Example 1 except that a comparative primer having a composition obtained by removing potassium hexatitanate from the formulation of the primer of Reference Example 9 in Table 1 was used.
The results are shown in Table 6.

Comparative Example 10 A coating film was obtained in the same manner as in Example 2 except that a comparative primer having a composition obtained by removing potassium hexatitanate from the composition of the primer of Reference Example 9 in Table 1 was used.
The results are shown in Table 6.

Comparative Example 11 Lithium silicate 45 (150 parts) and zinc dust (850
Example 1 except that a comparative primer consisting of
A coating film was obtained in the same manner as in. The result is No. 6
Shown in the table.

Comparative Example 12 Lithium silicate 45 (150 parts) and zinc dust (850
Example 2 except that a comparative primer consisting of
A coating film was obtained in the same manner as in. The result is No. 6
Shown in the table.

From Table 6, it can be seen that in Examples 1 and 2 of the present invention, no rusting was observed and the coating agents were sufficiently practical. However, the topcoat paint contains alkali titanate, but the primer paint contains alkali silicate or colloidal silica and zinc dust, but does not contain alkali titanate. JP-A-52-144035 and JP-A-56-149465 Rusting was recognized in all of the coating films of Comparative Examples 9 to 12 based on the coating method combining the above.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Kazuto Uemura Inventor, 463 Kagasuno, Kawauchi Town, Tokushima City, Tokushima Prefecture In the Tokushima Plant of Otsuka Chemical Co., Ltd. (72) Misao Izumi, 10-5 Kawagishi Town, Suita City, Osaka Prefecture Cerastar Paint Co., Ltd. (56) References JP-A-56-149465 (JP, A) JP-A-52-144035 (JP, A)

Claims (2)

[Claims] 1. A method for imparting weather resistance to a metal material, which comprises laminating and coating the following coating material A and coating material B on a metal material in this order: coating material A: (a) from a group of alkali silicate and colloidal silica At least one selected, (b) at least one alkali titanate represented by the general formula M ₂ O · nTiO ₂ (M is an alkali metal, n is 6 or 8), and (c) zinc dust is mixed. Inorganic coating material B comprising: (a) at least one selected from the group of alkali silicates and colloidal silica, and (b) the general formula M ₂ O.nTiO ₂ (M is an alkali metal, n is 6 or 8). An inorganic coating material containing at least one alkali titanate represented by the formula (1). 2. The method for imparting weather resistance to a metal material according to claim 1, wherein the component (b) is blended in an amount of about 1.4 to 70 parts by weight per 100 parts by weight of the component (a).