Ceramic-coated electrically-conductive wire and method of making same

Claim 1

INSULATED WIRE COMPRISING AN ELONGATED, OXIDATIONRESISSTANT ELECTRICAL CONDUCTOR, AND MULTIPLE SEPARATELY FIRED CERAMIC COATINGS ON THE CONDUCTOR EACH CONSISTING ESSENTIALLY OF SUBSTANTIAL PROPORTIONS OF BOTH GLASSY AND CRYSTALLINE PHASES WHICH ARE THE PRODUCT OF PARTIAL FUSION OF A MIXTURE OF (A) A FRIT OF A COMPOUND SELECTED FROM THE GROUP CONSISTING OF LEAD BORATE, LEAD SILICO-BORATE, LEAD SILICATE, BARIUM BORO-SILICATE, BARIUM-ALUMINO-SILICO-BORATE AND MIXTURES THEREOF AND (B) A REFRACTORY DIELECTRIC MATERIAL, SAID REFRACTORY MATERIAL BEING 5 TO 90 PARTS BY WEIGHT OF SAID MIXTURE OF (A) AND (B), SAID GLASSY PHASE BEING FORMED FROM THE MELTED FRIT, IN WHICH ONLY PART OF THE REFRACTORY MATERIAL IS DISSOLVED, SAID CRYSTALLINE PHASE BEING FORMED FROM THE REMAINING UNDISSOLVED REFRACTORY MATERIAL AND BEING DISPERSED THROUGH SAID GLASSY PHASE.