Bonding thermosetting resins to polystyrene plastics

Claim 1

IN A METHOD OF MAKING COMPOSITE STRUCTURES HAVING A THERMOSET SOLID RESIN SELECTED FROM THE CLASS CONSISTING OF EPOXY RESINS AND PHENOLIC-ALDEHYDE RESINS SECURELY BONDED AT A SURFACE OF CONTACT WITH A SOLID POLYMER THAT COMPRISES A MAJOR PROPORTION BY WEIGHT OF AN ALKENYLAROMATIC COMPOUND AND A MINOR PROPORTION OF AT LEAST ONE POLYMERIZABLE MATERIAL SELECTED FROM THE GROUP CONSISTING OF COMJUGATED ALIPHATIC DIENES AND ETHYLENICALLY UNSATURATED POLYMERIZABLE NITRILES IN POLYMERIC COMBINATION, THE IMPROVEMENT THAT COMPRISES CONTACTING A SURFACE OF THE SOLID ALKENYLAROMATIC POLYMER WITH AN OXIDIZING FLAME WITHOUT VISIBLY MELTING THAT SURFACE, WHEREBY SUCH SURFACE IS MODIFIED AND RENDERED ADHERENT TO A THERMOSET SOLID RESIN, APPLYING TO THE RESULTING FLAME-TREATED SURFACE AN UNCURED LIQUIDE TO SOFT SOLID CURABLE THERMOSETTING RESIN-FORMING COMPOSITION SELECTED FROM THE CLASS CONSISTING OF UNCURED CURABLE EPOXY RESIN-FORMING COMPOSITION AND UNCURED CURABLE PHENOLIC-ALDEHYDE RESIN-FORMING COMPOSITIONS AND CURING SUCH RESIN-FORMING COMPOSITION WHILE IN CONTACT WITH THE FLAME-TREATED SURFACE TO OBTAIN A SOLID THERMOSET RESIN SECURELY BONDED AT THE SURFACE OF CONTACT WITH THE SOLID ALKENYLAROMATIC POLYMER.