Substrate Surface Treatment for Chlorinated Rubber Coatings

Natural or synthetic rubber is a highly unsaturated high molecular weight polymer with a high viscosity, sluggish film formation, and quick ageing that is unsuitable for coatings production. Made of natural rubber derivatives - chlorinated rubber or cyclized rubber - after the chlorination modification procedure to lower its molecular weight and modify the unsaturation of the molecular structure.

I. Properties of chlorinated rubber coating 

Chlorinated rubber is a non-toxic, odorless white powder or thin flaky solid that is non-irritating to human skin and dissolves to a slightly yellow solution. The resulting coated layer exhibits excellent adhesion, chemical resistance, rapid drying, water resistance, and flame retardant properties.

In the 1960s, chlorinated rubber coating technology gradually matured and soon became a major system in the coating industry. Architectural coatings, chemical anti-corrosion coatings, fireproof coatings, road marking coatings, automotive chassis coatings, ships and marine steel structure anti-corrosion coatings, and room temperature curing epoxy resin coatings are the two major anti-corrosion coating systems in use today.

II. The usage of chlorinated rubber coating in the substrates

Chlorinated rubber coating can be used as an anti-corrosion primer, intermediate paint, or topcoat. When matching the coating, it can be used alone or with other types of primers such as epoxy or acrylic primers as a primer, intermediate, or topcoat of the chlorinated rubber system.

In theory, chlorinated rubber coating should not react badly with other types of primers, such as alkyd, epoxy ester, and ammonia ester oil primers, but the phenomenon of biting the bottom may occur; it is not recommended to coat directly on zinc-rich primers (epoxy zinc-rich, inorganic zinc-rich, and water-based zinc-rich primers), to avoid the formation of zinc powder in the coating film of white powder - alkali.

When chlorinated rubber anti-corrosion paint is painted directly on steel structures, the substrate should be thoroughly cleared of rust, dust, oil, and other pollutants before painting, and the level of rust removal should reach Sa2.5 or St3; the surface roughness should be between 30 and 75 m, with the maximum roughness usually not exceeding 100 m; when painted directly on concrete structures, the concrete surface should be thoroughly cleaned of rust, dust, oil, and other pollutants before painting, and the level of rust removal should The surface of the concrete should be dry, clean, and free of dust.

Oil, water, moisture, dust, and salts should be removed from the primer or intermediate paint film's surface before applying the top coat; if the primer or intermediate paint exceeds the painting interval, or if the surface is too smooth or hard, the previous paint film's surface should be brushed before applying the chlorinated rubber top coat to ensure interlayer adhesion.