PRODUCTION OF MASTER BATCH FOR PACKING MATERIAL FOR PHOTOGRAPHIC SENSITIZED MATERIAL AND PRODUCTION OF MOLDING RESIN USING THE SAME MASTER BATCH

摘要

PURPOSE:To obtain a master batch for a packing material for packaging a photographic sensitized material having improved light screening properties by blending a polystyrene resin with carbon black, a specific dispersant and a lubricant, melting and kneading. CONSTITUTION:(A) A polystyrene resin for common use and an impact-resistant polystyrene resin are mixed with (B) carbon black, (C) 10-45wt.% based on the component B of a glycerol fatty acid ester as a dispersant and (D) 10-45wt.% based on the component B of a bis-fatty acid amide or stearic acid as a lubricant by a twin-cylinder mixer 6 at the same time to give a carbon black- containing polystyrene resin. Then the carbon black-containing polystyrene resin is fed to a kneading extruder 7, melted and kneaded to give a master batch for a packing material for photographic sensitized material having more improved dispersibility of carbon black.