| 摘要 |
PURPOSE:To obtain a resin composition excellent in, e.g., TiO2 dispersion, by feeding a highly viscous polyester resin and a specified titanium oxide to a continuous kneading extruder, melt-kneading the both and feeding an additional amount of a polyester resin to the mixture. CONSTITUTION:A polyester resin of an intrinsic viscosity >=0.4 and titanium oxide surface-treated with an aluminum compound (e.g., alumina) and/or a silicon compound (e.g., silica) and having an average particle diameter of 0.1-0.5mum and a water content <=0.5% are fed to a continuous kneading extruder so that the concentration of titanium oxide may be 20-70wt.% and melt-kneaded. An additional amount of a polyester resin is added so that the desired concentration may be attained to obtain the purpose polyester resin composition. This composition has good whiteness and can be suitably used as a material for molding a white film useful as a reflective photographic support.
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