公开(公告)号：DE4240983A1

公开(公告)日：1994-06-09

申请号：DE4240983

申请日：1992-12-05

Applicant: BASF AG

Inventor： BRANDSTETTER FRANZ DR ,  WITTMER PAUL PROF DR ,  THIELE REINER PROF DR

IPC: B01J19/24 ,  C08F2/00

Abstract: Process for the prepn. of copolymers of radical-polymerisable vinyl monomers having vastly different copolymerisation parameters, by polymerisation under conditions that avoid a change in concn. with increasing polymer mass fraction, and where one or more monomers are added during at least part of the reaction. The process is characterised by the use of a cycle reactor having an essentially remixing operating ratio as a polymerisation vessel, with the monomer(s) being added to the reactor at 3 or more different positions. The no. of feed positions, N, is given by equation N is at least Yp/(deltaYP,Z.Kr) (I) Yp = polymer mass fraction of the reacted mixt.; delta Yp,z = difference in polymer mass fraction between two consequent feed positions; and Kr = cycle ratio. USE/ADVANTAGE - Suitable for the polymerisation of the following monomer pairs: acrylonitrile-vinyl acetate, methylmethacrylate-maleinimide and styrene-ethyl acetate. The process avoids the need for high solvent and/or initiator concns. which reduce the rate of polymerisation, increases the area of cooling surface without creating dead zones, improves the homogeneity of the reaction mixt. and requires less powerful mixing performance.

公开(公告)号：DE4235786A1

公开(公告)日：1994-04-28

申请号：DE4235786

申请日：1992-10-23

Applicant: BASF AG

Inventor： BRANDSTETTER FRANZ DR ,  WITTMER PAUL PROF DR ,  GAUSEPOHL HERMANN DR ,  THIELE REINER PROF DR

IPC: B01J19/24 ,  C08F4/48 ,  C08F12/08 ,  C08F12/06 ,  C08L25/04

Abstract: A process for the prepn. of transparent polystyrene (I) by anionic polymerisation is claimed whereby the polymerisation is carried out in a continuously operating tubular reactor with intermediate feed points. the initiator and less than 50% of the monomer are fed to the reactor inlet and the balance of the monomer is added in at least one other point downstream of the entrance. USE/ADVANTAGE - The process is useful for the prodn. of (I) with high transparency and low residual monomer content. (I) have high transparency with a low residual monomer content and the process is economical and has a high space-time yield.