简介 |
The invention concerns a catalytic system used for preparing polybutadienes by polymerization, a method for preparing said catalytic system and a method for preparing polybutadienes using said catalytic system. The inventive catalytic system is based on at least : a conjugated diene monomer, a salt of one or more rare earth metals of an organic phosphoric acid, said salt being suspended in at least a saturated inert hydrocarbon solvent of aliphatic or alicyclic type, an alkylating agent consisting of an alkylaluminium of formula AIR3 or HalR2, the mol ratio (alkylating agent/ rare earth salt) being greater than 5, and a halogen donor belonging to the family of alkylaluminium halides other than alkylaluminium sesquihalides, and in accordance with the invention, said catalytic system comprises said rare earth metal(s) in a concentration not less than 0.005 mole/l.
© KIPO & WIPO 2007 |