JPH02215869A - Heat-resistant coating - Google Patents

Abstract

PURPOSE:To prepare a heat-resistant coating excellent in the durability and capable of preventing adhesion of spatter for a long period by compounding a spherical ceramics and a layered ceramics into a coating compsn. obtd. by adding a silicone resin binder to a ceramics which is inert to a fused metal. CONSTITUTION:A ceramics which is insert to wetting with a metal (such as an oxide ceramics, e.g. Al2O3, MgO, or SiO2; a nitride ceramics, e.g. Si3N4 or AlN; or a carbide ceramics, e.g. SiC) is compounded with 10-40wt.% spherical ceramics, 30-50wt.% layered ceramics (e.g. graphite, talc, or mica), and a silicone resin binder, thus producing a heat-resistant coating for preventing adhesion of spatter during welding or fusion cutting work.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention aims to protect equipment used in that environment and jigs used in parts processing from fine molten metal particles (referred to as spatter) found during welding and fusing operations for a long period of time. It is a heat-resistant paint that is resistant to heat, light, and impact, and is intended to protect people from crossing.

During welding and fusing operations, intense ultraviolet rays are emitted along with spatter, and equipment and jigs used in this environment are constantly exposed to spatter, thermal shock, and ultraviolet rays, resulting in various problems such as primary damage. arise.

If spatter adheres to equipment or jigs, it may damage the appearance.
This may cause trouble. In particular, spatter adhering to the jig has a serious effect on dimensional accuracy, leading to a decline in quality.

Various types of organic-based spatter adhesion prevention agents have been proposed in the past, but all of them are aimed at preventing the welding base metal, so they are sufficient if they can be used for a short time. It is not suitable for this purpose. However, spatter adhering to the jig requires physical removal using a knife or hammer, which can damage the jig and reduce production efficiency.

The heat-resistant paint of the present invention is a completely new heat-resistant paint for preventing spatter adhesion, which has excellent durability, shows little deterioration of the coating film under the above-mentioned harsh conditions, and exhibits a stable spatter adhesion prevention effect over a long period of time.

The present invention will be explained in more detail below.

Molten metal particles generated during welding and fusing operations are mainly composed of iron, so when turning them into paint, it is necessary to
The Q-ax must be sufficiently inert to molten iron. Furthermore, it is essential that the binder that binds the ceramics has sufficient resistance to continuously generated intense ultraviolet rays, heat resistance, and sputter impact.

In view of these circumstances, as a result of many experiments, the ceramics applicable to the present invention are Al, 03. ZrO,, Mg0,81
0x.

813N4. It has been found that Cr, C, SIC, AIN, etc. act effectively.

All of these ceramics have the characteristics of high melting point and high hardness, exhibit sufficient durability against the thermal shock and physical shock of sputtering, and are also highly effective in preventing wear of the coating film.

In addition, spherical ceramics and layered ceramics are
The reason why the mixing ratio is limited to 10 to 40 weight percent and 30 to 50 weight percent of the solid content of the ceramic is as follows. In other words, paints containing spherical ceramics can be highly filled without increasing the solvent dilution ratio compared to amorphous ceramics, and this makes the surface layer ceramic, which improves the characteristics of serapots. Useful for full functioning.

Mg0,810 as spherical ceramics. , *t2o
, +ZrO2, etc., and this performance can be fully expected no matter which spherical ceramic is used. The reason why the blending ratio was specifically limited was because even if more spherical ceramics were added, a dramatic improvement in performance could not be expected, and the balance between raw material cost and performance was considered.

In addition, the great characteristic of ceramics, which has a layered structure, is that it gives a smoothing effect to the paint film, making it less likely that dirt and ivy will stick to it, and preventing contamination of the paint film from welding heat, thereby maintaining its aesthetic appearance. Great effect. Ceramics with a layered structure include graphite, talc, mica, etc. Graphite can be used for coatings that do not require coloring, and high-density graphite with advanced crystallinity is particularly effective. do.

The reason for limiting the blending ratio of ceramics having a layered structure is that if the ratio is below the claimed range, the characteristics of the layered structure will not be fully manifested, and if it is above, the coating film will be brittle and the adhesive strength of any of the base materials will be insufficient. The silicone resin used as the binder for the above ceramics can be methyl and phenyl silicone, and both of these resins gradually change to siloxane, an inorganic substance, at a temperature of about 350°C, and can be filled. It is suitable for heat-resistant paints used at high temperatures because it firmly holds the fine ceramic powder of the agent and forms a durable coating.

The paint of the present invention is made by blending silicone resin with fine ceramic powder, dispersion and anti-settling agents, antifoaming agent, 9 coloring agents, etc. It can be used for brushing, spraying and dipping by diluting with an appropriate amount of solvent.

Since the jigs used during welding and fusing operations are used in environments such as high-temperature arcs and plasma flames, there is no need to pre-heat the coating film to make it into a polymer, making it easy to implement on-site. It is a heat-resistant paint with high quality and high JN value.

Example 9 will be described below.

Example 1 Alumina oxide of 5i or less, 25 weight of ceramics x 1 silica of 7 weight of 5 microns or less as spherical ceramics, 9 weight of high-density graphite as layered ceramics of 5 microns or less, and their binder. Phenyl silicone 50 weight x (5ON xylene-stripped product) and the remainder xylene were prepared by applying the composition to three rolls to make a paint, and applying this paint to a welding jig used for parts for construction machinery to make it durable. The sputtering performance and durability of the coating film were confirmed. Welding conditions were 35v.

3zo*, s minute welding, 0.5 minute pause - cycle 6
h r s/D *yf) is in operation.

After 4 weeks, the coating film showed no damage or deterioration due to SPAVTER® thermal shock or arcing, and the spatter resistance remained unchanged from the beginning, maintaining good rolling properties.

Example 2 Zirconia oxide ceramic 120 with a power of 10 or less
Weight and as spherical and layered ceramics less than 7 microns each weighs 8! Add Gnesia and 10 weight X of Merck, which will serve as a binder for the Cerasix fine powder.
A mixture of methyl silicone of 0 weight When the coating film performance was evaluated under the same welding conditions, there was no adhesion of spatter, and no damage or deterioration of the coating film was observed even after one month, and there was no contamination from the Wi contact arm.

Next, we will discuss the performance effects of paints that do not contain spherical ceramics and layered ceramics.

Example 3 Alkyl silicone and silica oxide ceramics of 5Z chlorine or less were mixed to 20% by weight and 25% by weight, respectively, and 50% by weight (xylene cut product by 50% by weight) of methyl silicone was used as the binder, and the remainder was A mixture prepared with xylene solvent was passed through three rolls to form a paint.

The coating was applied with a brush to the same object as in Example 1, and the coating film performance was evaluated under the same welding conditions. After about 3 weeks, the coating film was significantly contaminated by the welding beam and had a poor aesthetic appearance. Spatter easily adhered to the coated surface, and damage caused by spatter was large.

It has been found from the above examples that the coating composition described in the claims acts effectively as a sputter adhesion prevention coating used under severe conditions.

Claims (1)

[Claims] In a coating composition containing oxide, nitride, or carbide ceramics that are inert against metal wetting, and a silicone resin added to their binder, the amount is 10 to 40% by weight based on the solid content of the ceramics. % spherical ceramics and 30
A heat-resistant paint that has a layered structure of ~50% by weight and contains inert ceramics mixed with molten metal.