| 摘要 |
A copolyester is formed of at least one aromatic dicarboxylic acid member, at least one aliphatic dicarboxylic acid member (an alkyl- or alkenyl-substituted succinic acid or anhydride thereof), at least one C2-C10 glycol, at least one polymeric polyol member, and an optional polymeric polycarboxylic acid member. The polymeric polyol member is either a polymeric polyol having a molecular weight of 300-3,000, or a mixture of polymeric diol having a molecular weight of 300-3,000 and a non-polymeric polyol. The polymeric polyol may be a polyester such as polycaprolactone or a polyether such as a trimethylolpropane/propylene oxide adduct. The preferred resultant thermoplastic copolyester has a glass transition temperature of less than 0 DEG C. and a high polymer melting temperature. It is useful as an adhesive both by itself and as an ingredient of hot melt or solution adhesive formulations. In producing the copolyester, an intermediate copolyester of the aromatic dicarboxylic acid member, the alkphatic dicarboxylic acid member, and the glycol is chain extended by reaction with the polymeric polyol member and optional polymeric polycarboxylic acid member in a 2-7 hour reaction at about 225 DEG -265 DEG under about 1-30 mm. Hg. pressure absolute.
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