Hydrophobically Modified Polyacrylic Acids for WB Tackifying Resin Dispersions

摘要

Tackifier resins (TRs) are of considerable significance in numerous adhesive applications, where they are com-pounded with elastomers as part of the adhesive formulation. TRs serve as a solid solvent for the elastomers. The low molecular weight fractions of the elastomer are dissolved by the tackifier, while the high molecular weight fractions exist as partially solvated aggregates. This system behaves as reinforcing agent embedded in a tacky semi-solid matrix and has a lower modulus and higher glass transition temperature than the unmodified elastomer. The lower modulus promotes bond formation and, coupled with the higher T_g, allows the system to resist bond rupture. Polymers typically tackified include ethy-lene vinyl acetate, styrene-butadiene rubber, natural rubber, polyisobutylene, styrene block copolymers and acrylics.