Process for preparing moldable polyamide polyester compositions

Claim 1

A process for the production of a moldable thermoplastic composition from a polyamide which contains free amine groups and is of softening point in the range 210° to 270° C. and of number average molecular weight in the range 10,000 to 30,000, comprising heating a mixture comprising from 50 to 99% by weight of said polyamide and from 50 to 1% by weight of a polyester which is of number average molecular weight less than 10,000 and of acid value in the range 30 to 90, said polyester being one produced by (a) condensing an aromatic or aliphatic dibasic acid or anhydride with a carboxylic aliphatic di- or poly-hydroxy compound, to produce a hydroxy-terminated polyester intermediate, and (b) reacting said hydroxy-terminated polyester intermediate with an acid which contains at least 3 carboxylic acid groups, or with an anhydride thereof, which is employed in a quantity such as to provide the polyester with an acid value in the range 30 to 90 and with a softening point of at least 100° C., heating of said mixture comprising polyamide and polyester being carried out at a temperature of at least 170° C. whereby water is produced by reaction between the polyamide and polyester and is allowed to escape from said mixture.