Process for producing polyester resin composition.

摘要

A process for producing a titanium dioxide containing polyester resin composition from which a white film useful as a reflective photographic support can be prepared is disclosed. Said process is performed by first supplying a polyester resin and titanium dioxide into a continuous kneading extruder, kneading them in molten state, and supplying an additional charge of the polyester resin to give a desired concentration of the titanium dioxide, wherein the first supplied polyester resin has an intrinsic viscosity of at least 0.40, said titanium dioxide having an average particle size of 0.1 - 0.5 mu m and a water content of no more than 0.5% and having been surface-treated with an aluminum compound and/or a silicon compound, and the concentration of titanium dioxide being in the range of 20 - 70 wt% when kneaded with the polyester resin in molten state.