AQUEOUS VIBRATION DAMPING COMPOSITIONS

摘要

The present invention provides an aqueous polymer dispersion for vibration damping comprising a film-forming polymer in the form of dispersed particles comprising a polymer phase P1 and different polymer phases P2 and P3; the polymer dispersion obtained by free radical emulsion polymerization. Controlling the difference in glass transition temperatures of the polymers in the various polymer phases results in effective sound damping as determined by a Damping Loss Factor of at least 0.1 over a temperature range of at least 40°C. determined at a frequency of 200 Hz over a temperature range of 10 to 65°C. Use of a chain transfer agent in the polymerization of the various monomer charges results in good appearance in the resultant vibration damping coating.