COPOLYESTERS, METHOD OF MANUFACTURING SAME, AND HOT MELT ADHESIVE COMPOSITIONS INCORPORATING SAME

摘要

A copolymer is formed of at least one symmetrical aromatic dicarboxylic acid member, at least one dimer acid, and at least one C2-C10 glycol, and at least one polyester polyol member. The polyester polyol member is either a polycaprolactone polyol having a molecular weight of 500-5,000, or a mixture of a polycaprolactone diol having a molecular weight of 300-5,000 and a nonpolymeric polyol. The resultant thermoplastic copolyester has a glass transition temperature of less than 25.degree.C and a polymer melting temperature greater than 70.degree.C, and is useful both as a hot melt adhesive by itself and as an ingredient of both pressure sensitive and non-pressure sensitive hot melt adhesive formulations. In producing the copolyester, an intermediate copolyester of the symmetrical aromatic dicarboxylic acid member, the dimer acid, and the glycol is chain extended by reaction at about 225-270.degree.C under a vacuum of about 1-30 mm. Hg. pressure.