What is intumescent fire retardant coating?

The intumescent fire retardant coating is composed of mountain flame retardant resin, flame retardant and carbon agent, dehydration to carbon catalyst and foaming agent. The coating will expand under the action of flame or high temperature, forming a foamed carbonaceous layer that is dozens of times thicker than the original coating, which can effectively block the effect of external heat sources on the substrate. So as to prevent the occurrence of combustion, the benefit of preventing combustion is greater than that of non-intumescent fireproof coatings.

a. Main film-forming substances
It is required that this kind of film-forming material not only has good normal temperature usability, but also can adapt to foaming at high temperature. Commonly used are: synthetic resin acrylic emulsion, polyvinyl acetate emulsion, epoxy resin, polyurethane, epoxy-polysulfide and so on. They are combined with organic flame retardants to make the coating have good flame retardancy.

b. Carbon forming agent
Under the action of high temperature and flame, the substance that can be carbonized quickly is called carburizing agent. They are the material basis for the formation of the carbonized foam layer, usually high-carbon polyhydroxy compounds, such as starch, pentaerythritol and hydroxyl-containing organic resins.

c. Dehydration to carbon catalyst
Its main function is to promote the dehydration and carbonization of hydroxyl-containing organic matter to form a non-combustible carbonaceous layer. Such substances mainly include ammonium polyphosphate, ammonium dihydrogen phosphate and organic phosphate.
Small foaming agent
The foaming agent can decompose a large amount of fire extinguishing gas when the coating is heated, and make the coating expand to form a sponge-like fine foam structure. Such substances include: ammonium phosphate, ammonium polyphosphate, urea, melamine, dicyandiammonium , Guanidine, chlorinated paraffin (70%), etc.

d. Filler, pigment
Generally, inorganic pigments and fillers have flame resistance, and they can increase the flame resistance of the coating. Commonly used are: mica powder, talcum powder, asbestos powder, kaolin, zinc oxide, titanium dioxide, calcium carbonate. Aluminum hydroxide, zinc borate, barium metaborate, antimony trioxide, etc.