The present invention provides a method for producing flame-retardant polycarbonate resin composition pellets using a twin-screw extruder.
The flame-retardant polycarbonate resin composition pellets comprise:
30-85% by weight of resin pellets (A), wherein polycarbonate resin with a Mw/Mn ratio of 2.7–3.4 is included in granules (A) at a content exceeding 40 wt%; 5 wt% or more but less than 25 wt% of phosphorus-based flame retardant (B); 0.1–1.0 wt% of polytetrafluoroethylene (C); 0–50 wt% polycarbonate resin flakes (D); 0–30 wt% styrene-based copolymer resin (E); and 0–15 wt% other additives (F) besides components (B) and (C). In this production method, components (A) to (F) are kneaded using a twin-screw extruder.
This twin-screw extruder has a screw configuration for the kneading section obtained by combining two or more of the following:
R kneading discs, N kneading discs, L kneading discs, L screws, sealing rings, mixing screws, and rotor screws.
These components are extruded as a wire from the extruder at a screw rotation speed of 370–830 rpm and a torque density applied to the screw shaft of 6.0–16.0 Nm/cm³ (6.0–16.0 N·m/cm³), then cut.
Country Code: JP
Application Number: CN202280076245.5
