| abstract |
Thermoplastic segmented elastomeric copolyether-esters which substantially consist of a plurality of recurring short-chain and long-chain ester units linked to one another by ester bonds, the proportion of the short-chain ester units of the formula <IMAGE> I where R is the divalent radical remaining after removal of the carboxyl groups of aromatic dicarboxylic acids having a molecular weight of <350 and A is the divalent radical remaining after removal of the hydroxyl groups of a diol having a molecular weight of <250, being from 15 to 75% by weight, and the proportion of the long-chain ester units of the formula <IMAGE> II where R is defined as above and B is the divalent radical remaining after removal of the terminal hydroxyl groups from a long-chain glycol, being from 25 to 85% by weight of the copolyester, and which contain from 0.01 to 5 mole %, based on copolyester, of trifunctional or more highly functional compounds, serving as branching agents, chemically incorporated into the polymer molecule. The copolyesters are particularly suitable for use in pressure-sensitive adhesives. |