Patent ID: 10081212

Abstract:
A non-pressure sensitive hot melt adhesive for use in mailer applications uses a styrenic block copolymer (SBC) with a hydrogenated mid-block as the primary polymer in the composition. The adhesive contains about 10% to about 50% by weight of the SBC, about 2% to about 30% by weight of a polyolefin polymer as a secondary polymer in the composition, about 10% to about 70% by weight of a suitable plasticizer, about 0% to about 30% by weight of a wax, about 0% to about 50% by weight of one or more tackifying resins, about 0.1% to about 4% by weight of a stabilizer, and about 0% to about 3% by weight of auxiliary additives, so that the viscosity of the composition is equal to or less than about 10,000 cP at 163° C. The formulation balances the cohesive and adhesive strength required to insure the adhesive fails cohesively to prevent paper tear. In addition, the presence of the secondary polymer allows additional oil absorption into the polymer, thus preventing oil from staining the substrates or surfaces without significantly increasing the viscosity.