| 摘要 |
A PROCESS FOR PRODUCING A STABILIZED OXYMETHYLENE COPOLYMER, WHICH COMPRISES SUBJECTING A CRUDE OXYMETHYLENE COPOLYMER TO TERMINAL STABILIZATION IN AN EXTRUDER (A) HAVING A TERMINAL-STABILIZING ZONE AND A VACUUM ZONE FOR VOLATILE COMPONENT REMOVAL TO OBTAIN A TERMINAL-STABILIZED OXYMETHYLENE COPOLYMER, SEPARATELY MELT-KNEADING A POLYOXYMETHYLENE AND A STABILIZER AND/OR ADDITIVE IN OTHER EXTRUDER (B), FEEDING THE RESULTING MELT-KNEADING MIXTURE IN A MOLTEN STATE INTO A SECTION OF THE EXTRUDER (A) FOLLOWING THE VACUUM ZONE FOR VOLATILE COMPONENTS REMOVAL SO THAT THE PROPORTIONS OF THE POLYOXYMETHYLENE TO BE FED FROM THE EXTRUDER (B) AND THE CRUDE OXYMETHYLENE COPOLYMER TO BE SUBJECTED TO TERMINAL STABILIZATION IN THE EXTRUDER (A) BECOME 1:3 TO 1:45 BY WEIGHT RATIO, AND KNEADING THE POLYOXYMETHYLENE, THE STABILIZER AND/OR THE ADDITIVE AND THE TERMINAL-STABILIZED OXYMETHYLENE COPOLYMER.
|
