elastic polymer blends and materials semicrystalline propylene with high glass transition temperature.

摘要

A composition elastic mixture comprising: (a) from 70% to 95% by weight, based on the total weight of the composition, of a polymer selected from the group consisting of a homopolypropylene and a random copolymer of propylene and at least a comonomer selected from ethylene, alpha-olefin C 4-C 12 and combinations thereof, the polymer having a heat of fusion, determined by DSC, less than 50 J / g as determined by ASTM E-794-95, and a melt index (MI) of less than 7 dg / min as determined by ASTM D1238 (190C, 2.16kg), and containing stereoregular propylene crystallinity, wherein the polymer and other components such as process oil show a single glass transition temperature (Tg1) as measured by DSC between 20 ° C and -50 °; and (b) from 5% to 30% by weight, based on the total weight of the composition, of a hydrocarbon resin having a glass transition temperature measured by increased DSC 20, wherein the hydrocarbon resin has a softening point of between 80 and 180, determined by ASTM E-28 (Revision 1996); (C) wherein (b) it is miscible with (a) and the blend composition shows a single glass transition temperature (Tg2) measured by DSC; with Tg2 higher than Tg1 by at least 1 ° C, and wherein the blend composition has a tension set of less than 20%, determined by ASTM D790.