INTUMESCENT FIRE-RETARDANT GRANULES AND THEIR USE IN A SHEET MATERIAL

摘要

Fire-retardant granules comprise (1) core particles of hydrated soluble silicate glass that intumesces in the presence of heat, and (2) a solid coating around the core particles that comprises a mixture of (a) halogenated organic compound that releases halogen when heated to a temperature less than about 250 DEG C.; and (b) an iron-containing compound adapted to react with said released halogen to form iron halide. The combined intumescence of the core particle and the catalytic effect of the coating on the particle achieves a unique fire-retarding action, especially in asphalt products such as asphalt shingles, but also in a range of other products.