Patent ID: 7138480

Claim:
A highly branched copolyester consisting essentially of at least two repeat units derived from at least one linear 3-hydroxycarboxylic acid or its ester of the structure R 2 O—CR 4 R 5 CR 6 R 7 C(O)OR 1 and at least one hyperbranching hydroxycarboxylic acid or its ester of the structure (R 2 O)n—R—[C(O)OR 1 ] m , wherein R is C 1-12 hydrocarbyl radical with n+m free valencies, R 1 is H, C 1-12 or hydroxyl substituted C 1-12 hydrocarbyl radical, R 2 is H or (O)C R 3 , R 3 , R 4 , R 5 , R 6 , R 7 is H or C 1-12 hydrocarbyl radical, n+m is 3 or more, and provided that one of n and m is 1.