Method of manufacturing a finely granular concentrate of fire-retarding foam-forming solid addition substances for plastics, varnishes, coating compositions, and similar substrates

摘要

A method is provided for producing a fine granular concentrate of fire-retarding, foam-forming solids for addition to host material including plastics, paints, coating compositions and the like by mixing particles of solid fire-retarding additives of particle size less than about 5 mu m with a polymeric material wherein the particles are surrounded and coated by said polymeric material, said polymeric material being compatible with or the same as the host material to which the coated particles are subsequently added to confer fire-retarding and foam-forming properties thereto. The steps include drying said polymeric-particle mixture, comminuting said polymeric-particle mixture to a granular product of less than about 50 mu m, and repeating the coating procedure at least one more time on said granular product by mixing said granular product with polymeric material, followed by drying and comminuting said granular-polymeric mixture to provide a granular concentrate having a size of less than about 50 mu m with an outer layer of said polymeric material, said polymeric material in at least the outer layer of granular concentrate being characterized by being capable of splitting off nitrogen and/or water under pyrolitic conditions.