| 摘要 |
PROBLEM TO BE SOLVED: To manufacture a polyester resin having an excellent moldability with an increased molecular weight and molecular weight distribution from a recovered polyester with a relatively low molecular weight as the raw material. SOLUTION: In the plasticization/melting process a homogeneously dispersed and mixed raw material mixture consisting of a low molecular weight straight chain saturated polyester resin material, a binder and a binding reaction catalyst is prepared and fed to a twin extruder in which the mixture is forcibly kneaded. In the deaeration process the mixture is heated to a temperature nearly above the melting point of the crystal of the polyester resin and a high vacuum of≤2,666 Pa is applied. In the thickening/reaction promotion process the thickening reaction is promoted. In the reaction stabilization process a homogeneous high viscosity state is achieved by completing the remaining thickening reaction. These processes are implemented stepwise. The supply of the raw material mixture containing the raw material resin, the binder and the binding reaction catalyst to the twin extruder in advance realizes a homogeneous dispersion and mixing, heightens the hermeticity of the resin, facilitates rapid deaeration of water and impurities and prevents hydrolysis reaction. COPYRIGHT: (C)2004,JPO
|
