Process for producing magnetic product

Claim 1

A PROCESS OF PRODUCING A MAGNETIC RECORDING STRIP, SAID PROCESS COMPRISING THE STEPS OF ADVANCING AN ELONGATED SUBSTRATE THROUGH A CURVED PATH DEFINED BY A CONVEX SURFACE AND A CONCAVE SURFACE, SAID CONVEX SURFACE AND SAID CONCAVE SURFACE BEING APPROXIMATELY EQUIDISENT FROM EACH OTHER THROUGHOUT SAID CURVED PATH, SAID SUBSTRATE BEING IN TAUT CONTACT WITH SAID CONVEX SURFACE, THE DISTANCE BETWEEN ADJACENT SURFACES OF SAID CONVEX SURFACE AND SAID CONCAVE SURFACE RANGING BETWEEN 1/32 AND 5/32 OF AN INCH, SAID PATH INCLUDING IN SEQUENCE A PREHEAT ZONE, A DECOMPOSITION ZONE AND A DWELL ZONE, PARTIALLY SEALING SAID PREHEAT ZONE AT ITS ENTRANCE, SAID DECOMPOSITION ZONE FROM SAID PREHEAT ZONE, AND SAID DWELL ZONE AT ITS EXIT BY GASKETS, HEATING SAID CONVEX SURFACE OF SAID PREHEAT ZONE TO A TEMPERATURE RANGING FROM 140 TO 180*C., HEATING SAID CONVEX SURFACE OF SAID DECOMPOSITION ZONE TO A TEMPERATURE RANGING FROM 180 TO 350*C., HEATING SAID CONVEX SURFACE OF SAID DWELL ZONE TO A TEMPERATURE RANGING FROM 160 TO 250*C., INTRODUCING A HEAT DECOMPOSABLE GAS TO SAID PATH APPROXIMATELY AT THE JUNCTION BETWEEN SAID DWELL ZONE AND SAID DECOMPOSITION ZONE, INTRODUCING AN INERT GAS TO SAID PATH APPROXIMATELY AT THE ENTRANCE TO SAID PREHEAT ZONE AND APPROXIMATELY AT THE EXIT FROM SAID DWELL ZONE, EXHAUSTING SAID PATH APPROXIMATELY AT THE JUNCTION BETWEEN SAID PREHEAT ZONE AND SAID DECOMPOSITION ZONE, THE PARTIAL PRESSURE OF SAID HEAT DECOMPOSABLE GAS RANGING FROM 75 TO 125 MM. HG, SAID AUXILIARY GAS FLOWING THROUGH SAID PATH AND BEING EXHAUSTED THEREFROM AT A FLOW RATE RANGING FROM 1 TO 10 CU. FU./HR., AND ADVANCING SAID SUBSTRATE AT A RATE OF 1 TO 80 FT.0MIN., SAID HEAT DECOMPOSABLE GAS INCLUDING AT LEAST IRON CARBONYL,THE AFOREMENTIONED STEPS BEING RELATED TO PRODUCE ON SAID SUBSTRATE A MAGNETIC STRATUM COMPRISING ESSENTIALLY A DISTRIBUTION OF MICROSCOPIC GRAINS SUBSTANTIALLY RANGING FROM 5,000 TO 20,000 A. IN EXTENT, SAID MAGNETIC STRATUM RANGING FROM 30 TO 100 MILLINTHS OF AN INCH THICK, SAID MAGNETIC STRATUM COMPRISING FROM 30 TO 70% IRON, FROM 30 TO 70% OF A METAL SELECTED FROM THE CLASS CONSISTING OF COBALT AND NICKEL, FROM 0 TO 40% OF AT LEAST ONE METAL SELECTED FROM THE CLASS CONSISTING OF CHROMIUM, MANGANESE, GADOLINIUM, VANADIUM, ALUMINUM, TITANIUM, COPPER AND NIOBIUM, AND FROMA TRACE TO 3% OF A NON-METAL SELECTED FROM THE CLASS CONSISTING OF OXYGEN AND CARBON OF WHICH AT LEAST BETWEEN A TRACE AND 1 AND 1/4% IS CARBON.