Patent ID: 9611639
Date: 2017-04-04
CPC Classifications: B32B,C08K,E04B,E04D

Claim:
1. A rooting membrane comprising: i. a first layer including a cured network of ethylene-propylene-diene rubber, where the cured ethylene-propylene-diene rubber is in the form of a crosslinked network, where said first layer includes from about 20 to about 50% by weight cured ethylene-propylene-diene rubber, from about 70 to about 100 parts by weight carbon black, from about 78 to about 103 parts by weight clay, from about 55 to about 95 parts by weight extender, and from about 1 to about 50 parts by weight expandable graphite, where the parts by weight are based upon 100 parts by weight of the cured ethylene-propylene-diene rubber, where the carbon black, clay, extender, and expandable graphite are dispersed throughout the crosslinked network, and where the expandable graphite has an onset temperature of at least 160° C.; and ii. a second layer including a cured network of ethylene-propylene-diene rubber, where said second layer is substantially devoid of expandable graphite.