公开(公告)号：WO1996025442A1

公开(公告)日：1996-08-22

申请号：PCT/US1996001852

申请日：1996-02-12

Applicant: THE DOW CHEMICAL COMPANY

Inventor： THE DOW CHEMICAL COMPANY ,  WOODSON, Gary, E. ,  ESNEAULT, Calvin, P. ,  MYERS, Michael, O. ,  MARCHAND, Gary, R.

IPC: C08F297/04

CPC classification number: C08F297/04

Abstract: The invention is a process for the preparation of tapered block copolymers according to one of the formulae: B-t-A or A-B-t-A, wherein A comprises a polymer block derived from one or more monovinylidene aromatic monomers, B comprises a polymer block derived from one or more conjugated dienes, and t is a tapered polymer block derived from one or more monovinylidene aromatic monomers and one or more conjugated dienes wherein the portion of the block closest to block A is rich in monovinylidene aromatic monomer units, the portion of the block closest to block B is rich in conjugated diene units and the relative amount of conjugates diene and monovinylidene aromatic monomer units gradually changes along the backbone of the tapered block, comprising: a) contacting one or more conjugated dienes with a monofunctional lithium alkyl initiator or a polymer block derived from monovinylidene aromatic monomers with a terminal living lithium anion capable of initiating anionic polymerization and a hydrocarbon solvent, in a closed reactor equipped with a reflux condenser under conditions of reflux; b) partially polymerizing the one or more conjugated dienes; and c) after step b), contacting with the reaction mixture one or more monovinylidene aromatic monomers under conditions such that the unreacted conjugated diene and monovinylidene monomers polymerize; wherein the materials condensed during the process are recycled to the reactor.

Abstract translation: 本发明是一种制备根据下式之一的锥形嵌段共聚物的方法：BtA或ABtA，其中A包含衍生自一种或多种单亚乙烯基芳族单体的聚合物嵌段，B包含衍生自一种或多种共轭二烯 ，t是衍生自一种或多种单亚乙烯基芳族单体和一种或多种共轭二烯的渐缩聚合物嵌段，其中最接近嵌段A的嵌段的部分富含单亚乙烯基芳族单体单元，最接近嵌段B的嵌段的部分为 富含共轭二烯单元和共轭二烯和单亚乙烯基芳族单体单元的相对量沿着锥形嵌段的主链逐渐变化，包括：a）使一种或多种共轭二烯与单官能的烷基锂引发剂或衍生自单亚乙烯基的聚合物嵌段 具有末端活性的锂离子能引发阴离子聚合的芳族单体和 在回流条件下装备有回流冷凝器的封闭反应器中; b）部分聚合所述一种或多种共轭二烯; 和c）在步骤b）之后，使反应混合物与一种或多种单亚乙烯基芳族单体在未反应的共轭二烯和单亚乙烯基单体聚合的条件下接触; 其中在该过程中冷凝的材料被再循环到反应器中。