As a functional architectural coating, fire-resistant coatings are also composed of base materials, pigments, fillers and additives. The fire retardant additives and fire prevention mechanisms of non-intumescent fire retardant coatings (also known as ordinary fire retardant coatings) and intumescent (also called foaming) fire retardant coatings are different.
In the composition of non-intumescent fire retardant coatings, it is necessary to contain flame retardant (fire retardant) agents. Phosphorous and halogen-containing organic compounds (such as decabromodiphenyl ether), sodium borate, antimony trioxide, etc. can be used for this purpose. Sodium borate is especially suitable as a flame retardant for vinyl acetate emulsions. Its addition amount is based on a 10% solution, preferably accounting for 40% to 60% of the polymer. The flame retardant ability of antimony trioxide itself is not high, but when it can generate antimony trichloride in the early stage of combustion, for example, when it is used together with chlorinated paraffin, it will exert superior flame retardant ability.
In order to obtain excellent fire performance, in addition to adding flame retardants, the choice of base material is also very important. Since elements such as halogens (usually chlorine and bromine) and phosphorus are very effective in improving fire resistance, it is better to choose a base material containing these elements. For example, as a base material, vinyl chloride or vinylidene chloride copolymer emulsion or chlorinated rubber emulsion is most advantageous. In addition, as the flame-retardant plasticizer, tricresyl phosphate and β-trichloroethylene phosphate can be used.
The fireproof mechanism of the intumescent fireproofing material is that when the decorative layer of the fireproof coating is exposed to the flame, the foaming components in the coating film are decomposed by heat to form a heat-insulating spongy foaming layer, thereby preventing the spread of the flame . The fire retardant additives in coatings are mainly foaming components, including carbon sources, foaming agents and organic nitrogen compounds, etc., and they can be used in conjunction. Various foaming ingredients are exemplified below.
① Carbon source, such as starch, pentaerythritol, etc.;
②Foaming agent, such as ammonium phosphate, ammonium dihydrogen phosphate, ammonium polyphosphate, sodium borate, etc.;
③Organic nitrogen compounds, such as glycine, guanidine, dicyandiamide, urea, melamine, etc.
