Process for the synthesis of crystallizable 3,4-polyisoprene and isoprene-butadiene copolymers having high vinyl contents
US5239023A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 17, 1992 |
| Grant date | Aug 24, 1993 |
| Priority date | — |
| Expiry date | Aug 17, 2012 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08F2410/01
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
Crystallizable 3,4-polyisoprene and isoprene-butadiene copolymers having high vinyl contents can be synthesized in organic solvents to quantitative yields after short polymerization times by utilizing the catalyst systems of this invention. The 3,4-polyisoprene made utilizing this catalyst system is strain crystallizable and can be employed in tire treads which provide improved traction and improved cut growth resistance. This invention specifically discloses a process for the synthesis of 3,4-polyisoprene which comprises polymerizing isoprene monomer in an organic solvent at a temperature which is within the range of about -10.degree. C. to about 100.degree. C. in the presence of a catalyst system which is comprised of (a) an organoiron compound which is soluble in the organic solvent, wherein the iron in the organoiron compound is in the +3 oxidation state, (b) a partially hydrolyzed organoaluminum compound which was prepared by adding a protonic compound selected from the group consisting of water, alcohols and carboxylic acids to the organoaluminum compound, and (c) a chelating aromatic amine; wherein the molar ratio of the chelating amine to the organoiron compound is within t…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.