Process of producing high temperature resistant insulated wire, such wire and coils made therefrom

Claim 1

THE PROCESS OF PRODUCING A COIL OF INSULATED WIRE WHICH COMPRISES COATING THE WIRE IN UNWOUND FORM WITH A SLURRY CONSISTING ESSENTIALLY OF REFRACTORY MATERIAL IN A SILICONE BINDER FOR IMPARTING FLEXIBILITY TO THE COATING THUS APPLIED TO THE WIRE, HEATING THE COATED WIRE TO A TEMPERATURE WITHIN THE RANGE OF 300* TO 1000*F. TO PRODUCE A COATING ON SAID WIRE CONTAINING FROM 10% TO 50% OF THE SILICONE BINDER IN THE SAID SLURRY, THEREAFTER COATING THE THUS COATED WIRE WITH A SECOND SLURRY CONSISTING ESSENTIALLY OF GLASS FRIT AND A SILICONE BINDER, AND HEATING THE THUS COATED WIRE TO A TEMPERATURE WITHIN THE RANGE OF FROM 300* TO 1000*F. TO PRODUCE A GLASS FRIT COATING CONTAINING FROM 10% TO 50% OF THE BINDER IN SAID SECOND SLURRY AND TO BOND SAID FLASS FRIT COATING TO THE UNDERLYING COATING OF REFRACTORY MATERIAL, THEREBY PRODUCING FLEXIBLE INSULATED WIRE HAVING A LAYER OF REFRACTORY MATERIAL ON THE WIRE AND AN OVERLYING LAYER OF GLASS FRIT BONDED TO THE REFRACTORY LAYER, WHICH WIRE CAN BE WOUND AND UNWOUND WITHOUT CRACKING THE SAID INSULATION, WINDING THE THUS COATED WIRE ONTO A STORAGE SPOOL IN A PARTIALLY CURED CONDITION, THEREAFTER UNWINDING THE COATED COIL FROM THE SPOOL AND FORMING THE WIRE INTO A COIL, AND HEATING THE FORMED COIL TO A TEMPERATURE OF FROM 700* TO 2000*F. TO REMOVE SUBSTANTIALLY ALL OF THE CARBON CONTENT OF THE RESIDUAL ORGANIC BINDER AND FUSE THE REFRACTORY MATERIAL AND GLASS FRIT PRODUCE UPON COOLING AN INSULATED WOUND WIRE RESISTANT TO HIGH TEMPERATURE.