Polyisobutylene adhesive comprising polyolefin copolymer additive

An adhesive composition comprising:

• at least 50 wt. % of polyisobutylene polymer component, wherein the polyisobutylene polymer component comprises a first polyisobutylene polymer having a weight average molecular weight no greater than 150,000 g/mole and a second polyisobutylene polymer having a weight average molecular weight greater than to 300,000 g/mole;
• wherein the first polyisobutylene polymer is in an amount equal to or greater than the second polyisobutylene polymer;
• optionally at least one tackifier;
• optionally less than 10 wt. % of polymerized units at least one (meth)acryl monomer;
• and a component that improves adhesion to metal consisting of polyolefin copolymer comprising polymerized units of C2-C4 alkylenes and a carboxylic acid or an anhydride thereof, wherein the polyolefin copolymer has an acid number of less than 40 mgKOH/g and is present in an amount up to 20 wt. % of the adhesive composition;
• and
• wherein the adhesive composition is a pressure sensitive adhesive.