Molecular weight modifier for use with lanthanide and actinide catalysts
US4663405A · kind A · utility
Assignees
Inventor
Key dates
| Filing date | Apr 16, 1986 |
| Grant date | May 5, 1987 |
| Priority date | — |
| Expiry date | Apr 16, 2006 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08F36/04
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
Lanthanide and actinide catalyst systems normally appear to be "pseudo-living" when they are used to polymerize conjugated diolefin monomers into polymers. Polymerizations which are catalyzed with such catalyst systems produce polymers which have increasingly high molecular weight as monomer conversions are increased. Consequently, any change in polymerization time or conversion may affect the polymer's ultimate molecular weight. This has made controlling the molecular weight of polymers which are made utilizing lanthanide and actinide catalysts difficult. It has been unexpectedly discovered that vinyl halides can be used as molecular weight regulators for polymerizations which are catalyzed with lanthanide and actinide catalyst systems. Accordingly, the present invention relates to a process which comprises polymerizing at least one conjugated diolefin monomer in the presence of (a) a catalyst system which is comprised of (1) an organoaluminum compound, (2) an organometallic compound which contains a metal from Group III-B of the Periodic System, and (3) at least one compound which contains at least one labile halide ion; and (b) a vinyl halide.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.