EPDM laminate
AssigneeGenCorp Inc.
InventorsFredric D. Metcalf, John G. Sommer
Life of this patent
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Abstract
Cured rubbery carbon black reinforced EPDM roofing membranes are joined at their primed seams by a seaming tape comprising a carbon black reinforced compounded lightly cured blend of a butyl rubber and a polyisobutylene. The tape can exhibit a peel strength of at least about 2.5 pli at about 158.degree. F.
Claims5
A laminate comprising two cured, carbon black reinforced rubbery EPDM membranes joined together at their primed seams by a seaming tape comprising a lightly cured to a low cross-link density, carbon black reinforced, compounded, tacky and rubbery composition comprising from about 40 to 60 parts by weight of polyisobutylene having an average viscosity molecular weight Mv.times.10.sup.-4 of from about 0.60 to 1.40 and from 60 to 40 parts by weight of at least one rubber selected from the group consisting of butyl rubber, chlorinated butyl rubber and brominated butyl rubber having a raw Mooney viscosity (ML 1+8 at 212.degree. F.) of from about 18 to 75 and an unsaturation of from about 0.6 to 2.5 mol %, said tape exhibiting a peel strength of at least about 2.5 pli at about 158.degree. F. against said membranes.
Dependencies are inferred from the claim text.