Pipe enamel

Claim 1

AN IMPROVED ASPHALTIC PROTECTIVE COATING COMPOSITION HAVING INCORPORATED THEREIN FROM 17% TO 25% BY WEIGHT OF AN INERT MINERAL FILLER OF A FINENESS PERMITTING 90% OF THE FILLER TO PASS THROUGH 325 MESH SCREEN CHARACTERIZED BY A MAXIMUM VISCOSITY OF 1,000 SECONDS (SAYBOLT FUROL) AT 375*F., A FLASH POINT OF AT LEAST 125* F. ABOVE THE TEMPERATURE AT WHICH THE COATING COMPOSITION HAS A VISCOSITY OF 1,000 SECONDS (SAYBOLT FUROL), A MAXIMUM PENETRATION AT 150*F. (50 G., 5 SECS.) OF 45, A MAXIMUM SETTLEMENT RATIO AT 450*F. OF 1.3, A WATER ABSORPTION OF LESS THAN 1.0% AFTER 35 WEEKS'' IMMERSIONS OF A 90-100 MIL FILM, A STAIN INDEX OF LESS THAN 15, A MAXIMUM SAG OF 1/16" AT 160*F. AFTER 24 HOURS, NO CRACKING AND DISBONDING AT -20*F., NO VISIBLE CRACKING UNDER BEND TEST AT 77*F., NO CRACKING UNDER IMPACT TEST AT 32*F., A MAXIMUM OF 9 MILS PENETRATION AT 85*F FOR 100 HOURS AS DETERMINED BY ROD DEFORMATION TEST, AN INITIAL ELECTRICAL RESISTIVITY OF AT LEAST 1X10**15 OHM-CM. AND AN ELECTRICAL RESISTIVITY GREATER THAN 1X10**12 OHMCM. AFTER 35 WEEKS'' IMMERSION ON A FILM OF SAID COMPOSITION IN WATER.