Pressure-sensitive adhesive compositions having high shear and low peel resistance

Claim 1

A pressure-sensitive adhesive composition comprising (1) from about 25% to about 42% by weight of the total composition of an elastomeric blend consisting of a rubber and an olefin terpolymer of ethylene, propylene and 1,4-hexadiene, wherein the weight ratio of ethylene monomer to propylene monomer is approximately 3:1 and said hexadiene is present in an amount of from about 1% to about 8% by weight, having a modulus, M 60 , at 60% elongation of from about 1 to about 1.5 megapascals and a polydisparity of up to about 10, the weight ratio of said natural rubber to said terpolymer in said blend being from about 7.5:1 to about 2:1; (2) from about 5% to about 15% by weight of the total composition of a liquid plasticizer component selected from the group consisting of isomeric liquid polybutenes, mineral oils, low molecular weight polyterpenes, low viscosity rosins and mixtures thereof, with the proviso that when mineral oil is utilized, it comprises no more than 50% of the liquid plasticizer component; (3) from about 12% to about 20% by weight of the total composition of a reinforcing filler; and (4) from about 30% to 50% by weight of the total composition of a solid tackifier component, selected from the group consisting of normally solid polyterpenes, solid rosins and mixtures thereof, said pressure-sensitive adhesive composition having a Williams plasticity of from about 2 mm to about 3 mm.