Patent ID: 8877848
Filing Date: 2014-11-04
Classification: C08F,C08K,C08L,C09D,G10K

Abstract:
1. 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 comprising the following steps: (a) polymerization of a first monomer charge M1 to give a polymer phase P1 followed by (b) polymerization of a second monomer charge M2 in the presence of P1 to give a polymer phase P2, (c) polymerization of a third monomer charge M3 in the presence of P1 and P2 to give a polymer phase P3, wherein the difference in glass transition temperatures between P1 and P2 is at least 20° C.; the difference in glass transition temperatures between P2 and P3 is at least 5° C. and a chain transfer agent is used in the polymerization of the monomer charges M1, M2 and M3.