Heat formable laminated sheet material

Claim 1

A RIGID, HEAT-FORMABLE LAMINATED STRUCTURAL MATERIAL COMPRISING A CORE LAYER (A-1) CONTAINING A BLOWING AGENT, SOLID SUB-STRATE LAYERS (A-2) AND (A-3) ON EACH FACE OF SAID CORE LAYER, SAID CORE AND SUB-STRATE LAYERS COMPRISING A GUM PLASTIC COMPOSITION SELECTED FROM THE GROUP CONSISTING OF (A) PHYSICAL MIXTURES OF BUTADIENE-ACRYLONITRILE RUBBER AND A RESIN SELECTED FROM THE GROUP CONSISTING OF STYRENE-ACRYLONITRILE RESIN AND MIXTURES OF STYRENEACRYLONITRILE RESIN WITH POLYVINYL CHLORIDE RESIN, (B) GRAFT COPOLYMERS OF STYRENE AND ACRYLONITRILE ON POLYBUTADIENE, AND (C) MIXTURES OF (B) WITH RESIN SELECTED FROM THE GROUP CONSISTING OF STYRENE-ACRYLONITRILE RESIN AND MIXTURES OF STYRENE-ACRYLONITRILE RESIN WITH POLYVINNYL CHLORIDE RESIN, A PROTECTIVE SKIN LAYER (B) ON THE OUTER SURFACE OF ONE OF SAID SUB-STRATE LAYERS, THE SAID SKIN LAYER (B) COMPRISING A MIXTURE OF 60 TO 85% OF POLYVINYL CHLORIDE RESIN AND CORRESPONDINGLY 40 TO 15% OF BUTADIENE-ACRYLONITRILE RUBBER, THE SAID BUTADIENE-ACRYLONITRILE RUBBER IS THE SAID SKIN BEING CURED, AND A GLOSSY SKIN LAYER (C) ON THE OUTER SURFACE OF THE OTHER SAID SUB-STRATE LAYER, THE SAID GLOSSY LAYER (C) COMPRISING A HOMOGENEOUS MIXTURE OF 51% TO 98% OF (C-A) A RESINOUS VINYL CHLORIDE POLYMER AND CORRESPONDINGLY 49% TO 2% OF (C-B) A GRAFT COPOLYMER OF FROM 10 TO 200 PARTS OF A MIXTURE OF STYRENE AND METHYL METHACRYLATE IN RATIO OF FROM 25:75 TO 40:60 GRAFT COPOLYMERIZED UPON 100 PARTS OF A RUBBER COPOLYMER, IN AQUEOUS EMULSION FORM, OF BUTADIENE AND STYRENE IN RATIO OF FROM 70:30 TO 85:15 AND (C-C) A RESINOUS COPOLYMER OF STYRENE AND METHYL METHACRYLATE IN RATIO OF FROM 25:75 TO 40:60, THE AMOUNTS OF (C-B) AND (C-C) RANGING FROM 75 TO 25 PARTS OF (C-B) AND CORRESPONDINGLY FROM 25 TO 75 PARTS OF (C-C) PER 100 PARTS OF (C-B) PLUS (C-C), THE SAID PERCENTAGES, RATIOS AND PARTS BEING BY WEIGHT.