JPS59221361A - Heat-resistant corrosion-proofing paint - Google Patents

Abstract

PURPOSE:To provide a heat-resistant corrosion-proofing paint for the coating of ships and marine constructions, having excellent resistance to white rust and heat, having a specific pigment concentration by volume, and containing specific amounts of ethyl silicate as a vehicle, zinc dust and fine aluminum flakes. CONSTITUTION:The objective paint can be prepared by compounding (A) ethyl silicate as a vehicle, (B) 65-85wt% (based on the solid content of the paint) of zinc dust, and (C) 3-15wt% of fine aluminum flakes having a diameter of <=50mu. The volume concentration of the pigment is selected to be 60-75wt%. EFFECT:Excellent corrosion proofness after the use in a high temperature environment. USE:Coating of the plants, etc. on land.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an inorganic metal paint, and more particularly to an inorganic metal paint that significantly improves white rust resistance and heat resistance.

Conventionally, inorganic zinc paints have been widely known as inorganic metal paints, and because they have superior corrosion resistance and heat resistance compared to ordinary organic heat-resistant and anti-corrosion paints, they are used for ships, offshore structures, land-based plants, etc. Used a lot. However, if the inorganic zinc coating is left untreated, white rust will occur due to the oxidation of the zinc, which will deteriorate the aesthetic appearance and inhibit the adhesion of the topcoat when it is applied. Also, since the melting point of zinc is 419℃, the inorganic zinc coating film has a melting point of 400℃.
It has poor heat resistance above 400°C, and the coating may peel off at temperatures above 400°C.
It had the disadvantage of causing defects such as discoloration.

Therefore, the inventors of the present invention have conducted extensive research into developing an inorganic metal paint that is less likely to generate white rust and reduce heat resistance as described above, and has found that it uses ethyl silicate as a color vehicle and a combination of zinc powder and aluminum powder. It was discovered that this method suppresses the occurrence of white rust and improves heat resistance.

The present invention was made based on such knowledge,
The gist of this is that the pigment volume concentration is in the range of 60% to 75%, ethyl silicate is used as a color vehicle, zinc powder is 65 to 85% by weight in the paint solids, and aluminum powder is 3 to 1% by weight.
The heat-resistant and anti-corrosion paint is formulated so as to contain 5% by weight of each aluminum powder, and the aluminum powder is a fine scale-like powder with a size of 50 μm or less.

The present invention will be explained in detail below.

In the paint of the present invention, the pigment volume concentration refers to the volume of the pigment in the paint expressed as a 100% ratio, and the bulking value of the paint component (bulking value = solid weight ÷ specific gravity (cc )), but this concentration was regulated at 60% to 75% because if it is less than 60%, the formed coating film is likely to crack and it is difficult to apply a thick film, and if it exceeds 75%, the formed coating film will be affected by the impact. This is because the physical properties of the coating film, such as hardness and adhesion, are significantly reduced.

Next, ethyl silicate is used as a color vehicle because it is self-curing, has high heat resistance, and can ensure adhesion even to comparative dazzling substrates. Next, add 65% lead powder to the paint solids.
The content is regulated to 85% by weight; if it is less than 65% by weight, the corrosion resistance will be poor, and if it exceeds 85% by weight, white rust will occur frequently. In addition, if the aluminum powder is less than 3% by weight, the occurrence of white rust cannot be suppressed and the heat resistance of the coating film will also decrease, and if it exceeds 15% by weight, it will not harden.
The physical properties of the coating film, such as adhesion and weather resistance, become poor. Also, aluminum powder in the form of scales is effective in preventing white rust and improving heat resistance, while spherical aluminum powder is less effective. Furthermore, if the size of the aluminum powder exceeds 50 μm, the physical properties of the coating film will decrease.

The solvent used in the paint of the present invention may be selected from general solvents such as toluene, xylene, methyl alcohol, and mineral spirit.
One or more types can be used, especially ethyl alcohol and normal butanol.

Alcohol solvents such as isobutanol are preferable.

Also, as a matter of course, Sin is used as an anti-sagging agent.

A small amount of fine powder, asbestos, etc. may be added, and a small amount of an organic resin such as polyvinyl butyral or silicone varnish may be added to improve painting workability and leveling of the coating film.

When the paint of the present invention is applied to the surface to be coated, scaly aluminum powder is arranged in a layer on the surface of spherical zinc powder in the paint layer, which suppresses the oxidation of zinc, resulting in white rust. This improves heat resistance and corrosion resistance after service in high-temperature environments. Therefore, when applying the paint of the present invention as an undercoat and then applying a top coat on top of that paint film,
It is possible to greatly reduce the number of steps required for surface treatment to remove white rust, and also to extend the service life of high-heat areas.

EXAMPLES The effects of the present invention will be explained in more detail with reference to Examples below.

EXAMPLE Using the paint components shown in Table 1, inorganic metal paints of each formulation example were prepared by high-speed stirring (disper dispersion).

A steel plate (70x
After drying at room temperature for 7 days, the following tests were conducted.

(1) Salt spray test: Exposure to 5% salt water spray at 35°C for 3,000 hours.

(2) Salt water immersion test @: Soaked in 3% salt water at room temperature for 1 year.

(3) Outdoor exposure test: Exposure for 2 years on an outdoor exposure stand (45° south facing).

(4) Heat resistance test: Maintained in a constant temperature oven at 550℃ for 300 hours.

(5) Salt water spray test after heat resistance test: After the test in (4) above, the salt water spray test in (1) was carried out as an example. The results of the above test are shown in Table 2. As is clear from the results in the same table, the paint of the present invention is more effective than conventional inorganic zinc paints.
Corrosion resistance is excellent, but white rust does not occur much. Also, regarding heat resistance, the heat resistance temperature increases and the corrosion resistance after the heat resistance test is also good.

Claims (1)

[Claims] Pigment volume acidity is in the range of 60% to 75%, ethyl silicate is used as a color vehicle, and paint solid content lead powder is in the range of 65 to 85%.
1. A heat-resistant and anti-corrosion paint which is formulated to contain 3 to 15% by weight of aluminum powder, and wherein the aluminum powder is a fine scale-like powder with a size of 50 μm or less.