Catalyst dispersion having improved stability against phase separation
US4461846A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 28, 1983 |
| Grant date | Jul 24, 1984 |
| Priority date | — |
| Expiry date | Mar 28, 2003 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S526/904
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
Catalysts for the polymerization of ethylene or its copolymerization with C.sub.3 -C.sub.2 alpha-monoolefins are often pre-activated by polymerizing a small amount of C.sub.4 -C.sub.12 alpha-monoolefin onto the catalyst in the presence of an alkyl aluminum compound. The resultant pre-activated catalyst component is used in the form of a dispersion in an inert solvent. The dispersions have a tendency to separate into two phases rapidly and are thus difficult to add uniformly to a polymerization reaction. When the alkyl aluminum compound is replaced by a synergistic mixture of an alkyl aluminum choride and an oxygen-containing aluminum compound having oxygen attached to at least one aluminum valence, a stable dispersion is formed which will not separate into two phases for long periods of time.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.