Intumescent mastic coating

Claim 1

AN INTUMESCENT FIRE RETARDANT MASTIC COATING COMPOSITION COMPRISING AN INTEMESCING AGENT, A VEHICLE AND A FILLER, SAID INTUMESCING AGENT COMPRISING ABOUT 20-65 PERCENT BY WEIGHT GRANULAR UNEXPANDED VERMICULITE HAVING A PARTICLE SIZE OF ABOUT 5-20 MESH, SAID FILLER BEING PRESENT IN ABOUT 10-50 PERCENT BY WEIGHT, SAID VEHICLE COMPRISING THE REMAINDER OF THE COMPOSITION AND INCLUDING 20-40 PERCENT BY WEIGHT OF A POLYMERIC MATERIAL, 2060 PERCENT BY WEIGHT OF A PLASTICIZER AND 10-35 PERCENT BY WEIGHT OF A CHLORINATED RESIN, SAID POLYMERIC MATERILA BEING SELECTED FROM THE GROUP CONSISTING OF LINEAR ISOBUTYLENE POLYMER, ISOBUTYLENE-STYRENE COPOLYMER AND ISOBUTYLENE-ISOPRENE COPOLYMER SAID PLASTICIZER BEING CONSTITUTED BY A PARAFFIN BASE PETROLEUM DISTILLATION RESIDUE CONDENSATION PRODUCT DERIVED FROM A NATURALLY CONTAINED HIGH MOLECULAR WEIGHT VISCOUS MATERIAL PERCIPITATED FROM A WARM PROPANE SOLUTION OF A RESIDUAL PARAFFIN BASE OIL FRACTION WHICH HAS UNDERGONE NO THERMAL DECOMPOSITION OR CHEMICAL CHANGE BEYOND THAT INDUCED BY ORDINARY FRACTIONAL DISTILLATION, SAID CONDENSATION PRODUCT BEING CHARACTERIZED BY AN IODINE NUMBER NOT SUBSTANTIALLY ABOVE 40, A SOFTENING POINT OF BETWEEN ABOUT 110* F.-200* F., AN AVERAGE MOLECULAR WEIGHT OF AT LAST ABOUT 1900 AND AT RESIN BEING SELECTED FROM THE GROUP CONSISTING OF CHLORINATED PARAFFIN, CHLORINATED BIPHENYL, CHLORINATED POLYPHENYL AND SELECTED MIXTURES THEREOF.