MANUFACTURE OF THERMOPLASTIC RESIN COMPOSITION FOR PHOTOGRAPHIC SHEET

摘要

PROBLEM TO BE SOLVED: To improve a productivity with high melt kneading effect and small re-aggregation or decomposition of a dispersant according to a heat of a titanium oxide pigment by using a rotor type biaxially continuous kneader. SOLUTION: A rotor type biaxially continuous kneader has a throttling mechanism for adjusting a fully filling degree of a material to control heating according to a friction at the time of kneading. Since the material is melt kneaded according to a frictional heat of the material in a kneading unit without particularly heating, kneading at a low temperature, or kneading near a melting point or softening point of a thermoplastic resin to be used can be performed. Kneading blades of a rotor 11 includes propulsion blades and return blades. A rotor section of the kneading blade is formed in a triangular start shape having three tips at substantially 120 degrees interval. The two rotors are engaged with one another in a screw portion to rotate in different directions to strongly knead and to suppress heating. This kneader is used to continuously and efficiently produce a composition having an excellent high temperature processability with little film defect even if a titanium oxide concentration is high.