| 摘要 |
PROBLEM TO BE SOLVED: To provide a preparation process of a branched thermoplastic polyester resin having a good extrusion property and a melt viscosity sufficiently high for extrusion foaming and extrusion blow molding, which preparation process generates only a small amount of by-product and leaves only a small amount of unreacted material. SOLUTION: A branched thermoplastic polyester resin is prepared by melting- mixing a thermoplastic polyester resin having a limiting viscosity of not less than 0.4 dl/g and a compound having at least 3 carboxyl groups in the molecule or its anhydride, cooling-solidifying the melt-mixture and then giving a heat- treatment. When the thermoplastic polyester resin has a hydroxide group equivalent of 100, the compound having at least 3 carboxyl groups in the molecule or its anhydride has a carboxyl group equivalent of 30-250.
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