Fina Research, S.a.

Labofina, S.a.

Michel Daumerie

Emmanuel Lanza

Jean Naveau

Jean M Naveau

Coupling of block base copolymers terminated by a lithium atom of the typical formula S-B-Li, in which S is a monovinylaromatic hydrocarbon block and B is a conjugated diene block, by the use of at least one difunctional deactivating coupling agent and at least one polyfunctional deactivating coupling agent in a molar ratio such that the linear polymer obtained by coupling represents 65 to 95% by weight of the total polymer material obtained by coupling.

Process for the preparation of block copolymers

Transparent linear resinous conjugated diene/monovinyl-substituted aromatic block copolymers of improved properties are prepared by forming a monovinyl-substituted aromatic homopolymer block referred to as S.sub.1, followed by forming a conjugated diene homopolymer block, referred to as B.sub.1 and linked to segments S.sub.1, followed by the formation of a conjugated diene/monovinyl-substituted aromatic random copolymer block, referred to as B/S and linked to segment B.sub.1, followed by the formation of a monovinyl-substituted aromatic homopolymer block, referred to as S.sub.2 and linked to segment B/S thereby forming the block copolymer S.sub.1 -B.sub.1 -B/S-S.sub.2 wherein the molecular weight of the S.sub.2 block is significantly greater than the molecular weight of the S.sub.1 block.

Growing community of inventors

Ghlin, Belgium

Michel Daumerie