| 摘要 |
<p>PROBLEM TO BE SOLVED: To achieve a recycle method for providing a polyester resin composition capable of manufacturing a bottle of an equal quality again from a used PET bottle (bottle to bottle). SOLUTION: A substantially completely cleaned waste PET bottle flake is mixed with a monomer PEN flake or a substantially completely cleaned waste PEN flake in a predetermined ratio. The mixed flake, which is dried to 50-80 ppm by a reduced-pressure vacuum drying, is kneaded in a twin kneading extruder heated to 250-280 deg.C filled with dried inert gas with addition of a condensation agent. Although hydrolysis occurs due to incomplete drying of both PET and PEN, two benzene nuclei possessed by a dicarboxylic acid of the PEN produced by the hydrolysis causes a strong induced linkage aiding an ester linkage by the action of the condensation catalyst to link between the PETs prior to melting, thereby preventing reduction of entire molecular weight and recovering an IV value.</p> |
