Patent ID: 6515059
Filing Date: 2003-02-04
Classification: C08J,C08L,Y02W

Abstract:
A method of recycling EPDM rubber comprising the steps of:devulcanizing previously cured EPDM rubber using mechanical treatment in the absence of chemical additives; and adding the devulcanized EPDM rubber to a composition for forming an elastomeric EPDM-based membrane for roofing such that said resultant membrane composition comprises: an EPDM rubber mixture including from about 50 to about 95 parts by weight virgin EPDM rubber, and from about 5 to about 50 parts by weight of the devulcanized EPDM rubber, to total one hundred parts by weight rubber, as the total polymeric component of the composition, from about 75 to about 300 parts by weight phr of a filler, and from about 35 to about 135 parts by weight phr of a processing oil, and a cure package, wherein the EPDM-based membrane has an unaged tensile at break of between 680 and 1585 p.s.i. and, demonstrates at least about 90 percent retention in tensile strength after about twenty eight days of heat aging at about 116 degrees Celsius.