Process of forming shaped articles of porous styrene polymers having impact-resistant surfaces

Claim 1

A METHOD OF MANUFACTURING A SHAPED MOLDED ARTICLE OF A POROUS CELLULAR STYRENE POLYMER WHICH COMPRISES: PARTIALLY COVERING THE INNER SURFACE OF A GAS-PERMEABLE MOLD ENCLOSING A VOLUME OF THE DESIRED SHAPE WITH A LAYER (A) OF A MIXTURE OF AN UNSATURATED POLYESTER RESIN AND A VINYL COMPOUND LIQUID AT ROOM TEMPERATURE; THEN COVERING SAID LAYER (A) WITH A SECOND LAYER (B) OF COMPACT EXPANDABLE PARTICLES OF A STYRENE POLYMER CONTAINING A RADIALY VOLATILE NON-SOLVENT ORGANIC LIQUID AS A RAISING AGENT, AND INTIALLY PARTLY POLYMERIZING SAID UNSATURATED POLYESTER RESIN AND SAID VINYL COMPOUND IN SAID LAYER (A), AND IN ANY ORDER; SUBSEQUENTLY FILLING THE REMAINING VOLUME OF THE MOLD WITH (C) PRE-EXPANDED POROUS CELLULAR PARTICLES OF A STYRENE POLYMER CAPABLE OF ADDITIONAL EXPANSION; AND HEATING THE CONTENTS OF THE MOLD AT A TEMPERATURE ABOVE THE SOFTENING RANGE OF BOTH THE EXPANDABLE COMPACT AND PRE-EXPANDED PARTICLES OF STYRENE POLYMERS WHEREBY SAID STYRENE POLYMERS ARE EXPANDED TO EXERT INTERACTING PRESSURE WITHIN SAID MOLD AND ARE FIRMLY UNITED WITH EACH OTHER AND SAID LAYER (B) IS FIRMLY UNITED WITH SAID LAYER (A) IN WHICH THE MIXTURE OF UNSATURATED POLYESTER RESIN AND VINYL COMPOUND IS SIMULTANEOUSLY POLYMERIZED AND HARDENED TO FORM AN IMPACT-RESISTANT SURFACE UPON THE MOLDED ARTICLE.

Claim 2

A METHOD OF MANUFACTURING A SHAPED MOLDED ARTICLE OF A POROUS CELLULAR STYRENE POLYMER WHICH COMPRISES: PARTIALLY COVERING THE INNER SURFACE OF A GAS-PERMEABLE MOLD ENCLOSING A VOLUME OF THE DESIRED SHAPE WITH A LAYER (A) OF A MIXTURE OF AN UNSATURATED POLYESTER RESIN AND A VINYL COMPOUND LIQUID AT ROOM TEMPERATURE; THEN COVERING SAID LAYER (A) WITH A SECOND LAYER (B) OF COMPACT EXPANDABLE PARTICLES OF A STYRENE POLYMER CONTAINING A RADIALY VOLATILE NON-SOLVENT ORGANIC LIQUID AS A RAISING AGENT, AND INTIALLY PARTLY POLYMERIZING SAID UNSATURATED POLYESTER RESIN AND SAID VINYL COMPOUND IN SAID LAYER (A), AND IN ANY ORDER; SUBSEQUENTLY FILLING THE REMAINING VOLUME OF THE MOLD WITH (C) PRE-EXPANDED POROUS CELLULAR PARTICLES OF A STYRENE POLYMER CAPABLE OF ADDITIONAL EXPANSION; AND HEATING THE CONTENTS OF THE MOLD AT A TEMPERATURE ABOVE THE SOFTENING RANGE OF BOTH THE EXPANDABLE COMPACT AND PRE-EXPANDED PARTICLES OF STYRENE POLYMERS WHEREBY SAID STYRENE POLYMERS ARE EXPANDED TO EXERT INTERACTING PRESSURE WITHIN SAID MOLD AND ARE FIRMLY UNITED WITH EACH OTHER AND SAID LAYER (B) IS FIRMLY UNITED WITH SAID LAYER (A) IN WHICH THE MIXTURE OF UNSATURATED POLYESTER RESIN AND VINYL COMPOUND IS SIMULTANEOUSLY POLYMERIZED AND HARDENED TO FORM AN IMPACT-RESISTANT SURFACE UPON THE MOLDED ARTICLE.