Hot melt pressure sensitive adhesive composition for attaching roofing membranes

The present invention relates to an adhesive composition that is useful to attach roofing membranes or underlayments to a roof area. Specifically, the present invention relates to an adhesive composition that is pressure sensitive and may be utilized to apply a roofing membrane in a peel and stick manner. Additionally, the present invention relates to a roofing membrane or underlayment having the adhesive composition of the present invention applied to at least one major face. An adhesive composition is provided for adhering together roofing materials such as EPDM rubber and thermoplastic polyolefin (TPO). The adhesive composition includes a rubbery polymer comprising a blend of a thermoplastic block copolymer selected from the group consisting of a styrene-butadiene-styrene block copolymer, a styrene-isoprene-styrene block copolymer, a styrene-ethylene/butylene-styrene block copolymer, a styrene-ethylene/propylene block copolymer and an ethylene-propylene block copolymer and combinations thereof and a polyisobutylene. Roofing articles incorporating the adhesive composition are also provided. The composition is a pressure sensitive adhesive that allows roofing articles to be applied in a peel and stick manner.