Waterproof self supporting sheet of plasticised polyvinyl butyral - with coal tar pitch or aromatic asphalt extract

摘要

Waterproofing self supporting sheet material of thickness 20-90 mils comprises 20-80 wt.% plasticised polyvinyl butyral resin (I) and 20-80 wt.% coal tar pitch or 20-85 wt.% (I) and 15-80 wt.% of a highly aromatic extract of asphalt. The pitch has a softening point (ASTM D-36) of 100-200 degrees F. As a waterproof membrane (flashing) in roofing, a pond lined or a gasket material having good U.V. resistance, cohesion, elongation, tensile strength and flexibility and low water absorption.