Impregnation of absorbent material

Claim 1

IN THE MANUFACTURE OF ASPHALT ROOFING, THE METHOD WHICH COMPRISES CONTINUOUSLY PASSING A SHEET OF FELT THROUGH A SATURATING BATH OF MOLTEN NORMALLY SOLID ASPHALT HAVING AN ASTM PENETRATION AT 77* F. OF ABOUT 20-15 MAINTAINED AT A TEMPERATURE OF 250-450* F. AND CONTAINING ABOUT 0.1-10 PARTS PER MILLION BY VOLUME OF A LIQUID DIHYDROCARBON SILICONE POLYMER HAVING ANTI-FOAM PROPERTIES IN ORGANIC LIQUIDS AND WHICH IS EFFECTIVE TO SUBSTANTIALLY INHIBIT FOAMING OF SAID MOLTEN ASPHALT BATH, SAID BATH BEING MAINTAINED OF SUFFICIENT DEPTH AND ELEVATED TEMPERATURE TO EFFECTIVELY ELIMINATE MOISTURE FROM THE FELT SHEET AND THOROUGHLY IMPREGNATE THE SAME WITH ASPHALT, WITHDRAWING THE TRAVELING FELT SHEET FROM THE BATH WHILE RETAINING A SUBSTANTIAL SURFACE FILM OF MOLTEN ASPHALT ON BOTH SIDES THEREOF PROVIDING A GLOSSY WET SHEET WHICH IS THEN COOLED TO PERMIT THE SURFACE FILM TO RAPIDLY DRY IN TO PROVIDE A SATURATED FELT SHEET WITH A MINIMUM OF 85% VOIDS FILLED WITH ASPHALT, AND THEN APPLYING A SURFACE COATING TO THE SHEET OF A MIX PREPARED BY ADDING FINELY DIVIDED SOLID INORGANIC FILLER TO PREVIOUSLY MIXED MOLTEN NORMALLY SOLID ASPHALT AND ABOUT 0.1-10 PARTS PER MILLION BY VOLUME BASED ON THE ASPHALT OF A LIQUID DIHYDROCARBON SILICONE POLYMER HAVING ANTI-FOAM PROPERTIES IN ORGANIC LIQUIDS AND WHICH IS SUFFICIENT TO INHIBIT ENTRAINMENT OF VAPOR BUBBLES IN THE COATING.