公开(公告)号：US3634381A

公开(公告)日：1972-01-11

申请号：US3634381D

申请日：1969-04-23

Applicant: BASF AG

Inventor： LEHNERER WOLFGANG ,  GUETERBOCK HERMANN ,  KINKEL KLAUS

IPC: B29C47/38 ,  B29C47/64 ,  B29C47/76 ,  B29C47/80 ,  C08F3/14

CPC classification number: B29C47/38 ,  B29C47/0009 ,  B29C47/6093 ,  B29C47/76 ,  B29C47/827

Abstract: A PROCESS AND APPARATUS FOR THE DEGRADATION OF HIGH MOLECULAR WE MOLECULAR WEIGHT POLYISOBUTYLENE IN A SCREW EXTRUDER PROVIDED WITH A SCREW SPINDLE BY THE ACTION OF SHEARING FORCES IN THREE DEGRADATION ZONES CONNECTED BY CONVEYING ZONES, THE POLYISOBUTYLENE BEING EXPOSED, AS IT IS CONVEYED FROM DEGRADATION ZONE TO DEGRADATION ZONE, TO TEMPERATURES ALTERNATING BETWEEN 150* AND 350*C. AND TO ALTERNATING SHEARING FORCES WHICH RESULT FROM VELOCITY GRADIENTS OF FROM ABOUT 100 TO ABOUT 700 SEC-1 MAINTAINED BETWEEN THE SHEARING SURFACES OF THE WALL OF THE BARREL AND THE SCREW WHICH ARE MOVING IN RELATION TO ONE ANOTHER.