Patent GB-927872-A (GB)
Title: Flame-retardant cellular polymers of vinyl-aromatic compounds
Inventor: POGANY GEORGE ALEXANDER
IPC: C08J9/224
Filed: 1960-05-17
Abstract: A polymer of a vinyl-aromatic compound in particulate form made expandable by internally incorporating a volatile expanding agent is rendered flame-retardant by internally incorporating 0,5-3% by weight of an organic phosphate and externally treating and coating, e.g. by simple mixing, with 5-20% by weight of a highly chlorinated non-volatile hydrocarbon, the total quantities of flame-retardant additives being not less than 8% by weight, the percentages being based on the weight of the polymer.  In addition the polymer particles may be treated and coated with up to 10% of antimony oxide applied in admixture with the chlorinated hydrocarbon.  The polymer particles may be pre-expanded.  An adhesive, e.g. low molecular-weight styrene polymer or water soluble or water-expandable adhesives as described in Specification 874,144 or finely divided silica gel or talc, may be included in the mixture to ensure that the particles become coated with the chlorinated hydrocarbons.ALSO:A polymer of vinyl-aromatic compound in particulate form made expandable by internally incorporating a volatile expanding agent is rendered flame-retardant by internally incorporating 0,5-3% by weight of an organic phosphate and externally treating with 5-20% by weight of a highly-chlorinated non-volatile hydrocarbon, the total quantities of flame-retardant additives being not less than 8% by weight, the percentages being based on the weight of the polymer.  In addition the polymer particles may be treated with up to 10% of antimony oxide.  The polymer particles may be pre-expanded. Specified are polymers of styrene, a -methyl styrene, vinyl toluene and p-chlorostyrene, copolymers of t these monomers, and copolymers of these monomers with other ethylenically unsaturated monomers, e.g. acrylonitrile, methyl methacrylate, vinyl acetate, butadiene and isoprene organic phosphates triphenyl, tritolyl or trixenyl orthophosphate and tris-(2,3-dibromophenyl) orthophosphate and chlorinated hydrocarbons chlorinated paraffin waxes and chlorinated naphthalenes.  Specification 874,144 is referred to.ALSO:A polymer of a vinyl-aromatic compound in particulate form made expandable by internally incorporating a volatile expanding agent is rendered flame-retardant by internally incorporating 0,5-3% by weight of an organic phosphate and externary treating with 5-20% by weight of a highly-chlorinated non-volatile hydrocarbon, the total quantities of flame-retardant additives being not less than 8% by weight, the percentages being based on the weight of the polymer.  In addition the polymer particles may be treated with up to 10% of antimony oxide.  The polymer particles may be pre-expanded.  Specified are polymers of styrene,  -methyl styrene, vinyl toluene and p-chlorostyrene, copolymers of these monomers, and copolymers of these monomers with other ethylerically unsaturated monomers, e.g. acrylonitrile, methyl methacrylate, vinyl acetate, butadiene and isoprene organic phosphates triphenyl, tritolyl or trixenyl orthophosphate and tris-(2, 3-dibromopropyl) orthophosphate expanding agents butanes, pentanes, dichlorodifluoromethane and carbon dioxide and chlorinated hydrocarbons chlorinated paraffin waxes and chlorinated naphthalenes.  An adhesive, e.g. low molecular-weight styrene polymer or water soluble or water expandable adhesives as described in Specification 874,144 or finely divided silica gel or talc, may be used to ensure that the particles become coated with the chlorinated hydrocarbons.