| abstract |
An intumescent coating composition having improved char yield, while maintaining its physical, mechanical, and esthetic properties comprises (a) particulate poly(phenylene ether), wherein the mean particle size of the poly(phenylene ether) is 1 to 100 micrometers; (b) a film-forming binder; (c) an acid source; (d) a blowing agent; and (e) optionally, a carbon source other than the particulate poly(phenylene ether); wherein polyolefins, homopolystyrenes, rubber-modified polystyrenes, styrene-containing copolymers, and hydrogenated and unhydrogenated block copolymers of an alkenyl aromatic compound and a conjugated diene are all absent from the composition. A method of forming the intumescent coating composition comprises: mixing the particulate poly(phenylene ether), the filmforming binder, the acid source, and the blowing agent, wherein the particulate poly(phenylene ether) has a glass transition temperature, and wherein the mixing is carried out at a temperature below the glass transition temperature of the particulate poly(phenylene ether). |