Process for producing sheets of reinforced polyester resin

Claim 1

PROCESS FOR THE MANUFACTURE OF REINFORCED POLYESTER RESIN SHEETS CAPABLE OF BEING SHAPED MECHANICALLY, WHICH COMPRISES THE STEPS OF FIRST IMPREGNATING A SUPPORTING LAYER OF A PERMEABLE REINFORCING MATERIAL WITH A SOLUTION IN A DILUENT CONSISTING OF A POLYHYDRIC ALCOHOL, A FROM THE GROUP CONSISTING OF A POLYHYDRIC ALCOHOL, A LOWER ALIPHATIC ALCOHOL, AND A VINYL MONOMER, OF A POLYVALENT METAL SALT SOLUBLE IN SAID DILUENT, SAID POLYVALENT METAL BEING SELECTED FROM THE GROUP CONSISTING OF TIN, IRON, ZINC, BORON, COBALT AND MANGANESE, SAID SALT BEING CAPABLE OF INITIATING AND THEN CONTROLLING THE POLYMERIZATION OF SAID POLYESTER RESIN UPON HEATING BELOW A PREDETERMINED TEMPERATURE, THEN IMPREGNATING SAID IMPREGNATED REINFORCING MATERIAL AT LEAST PARTIALLY STATE THERMOSETTING POLYESTER RESIN WHICH IS IN A PREGELLED STATE IN WHICH IT IS STABLE AT AMBIENT TEMPERATURE, SAID RESIN HAVING BEEN PREVIOUSLY BROUGHT TO SAID PREGELLED STATE BY ADMIXING WITH A CATALYST ADAPTED TO PERMIT INITIATING OF POLYMERIZATION, WITH SAID POLYVALENT METAL SALT SOLUTION, AND WITH A SUFFICIENT AMOUNT OF AN ALKYLATED PHENOL TO INHIBIT FURTHER POLYMERIZATION AND TO MAINTAIN THE RESIN IN SAID PREGELLED STATE.