Patent ID: 7388058

Claim:
A polyester blend composition comprising at least one branched biodegradable copolymer and at least one linear biodegradable copolymer wherein at least one of the linear biodegradable copolymers is selected from the group consisting of: an aromatic polyester copolymer (a) having repeating units comprising an acid component and a glycol component; wherein the acid component comprises about 50 to 90 mol % of copolymerized terephthalic acid, about 0.2 to 6 mol % of copolymerized sulfonic acid metal salt, and about 9.8 to 49.8 mol % of copolymerized aliphatic dicarboxylic acid or a copolymerized ester-forming derivative of the aliphatic dicarboxylic acid; and wherein the glycol component comprises about 50 to 99.9 mol % of copolymerized ethylene glycol and about 0.1 to 50 mol % of copolymerized diethylene glycol; and a polyester copolymer (b) prepared by copolymerization of said copolymer (a) with a poly(alkylene ether) glycol; and wherein at least one of the branched biodegradable copolymers is a branched polyester copolymer (c), and wherein said branched polyester copolymer (c) is prepared by polycondensation of said copolymer (a) with a poly(alkylene ether) glycol.