Sponge rubber rug underlay having improved heat age resistance

摘要

A sponge rubber rug underlay compound which is capable of withstanding a temperature of about 275 DEG F. for at least about 24 hours without appreciable degradation, or loss of resiliency. The compound comprises about 100 parts of a rubber which may be subject to oxidative degradation, between about 200 and about 250 parts of calcium carbonate, from about 0.5 to about 3.0 parts of an antioxidant and from about 1.5 to about 3.0 parts of an alkali metal phosphate.