Process for preparing ethylene-based polymers having low molecular weight
US5728783A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 30, 1996 |
| Grant date | Mar 17, 1998 |
| Priority date | — |
| Expiry date | Oct 30, 2016 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S526/905
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
Polymerization process to obtain elastomeric copolymers or terpolymers based on ethylene for cold flow improver (CFI) having a viscosimetric average molecular weight ranging between 600 and 16,000. a) The process includes polymerizing monomers in suspension in the presence of an alpha-olefin liquid under reaction conditions, in the presence of an amount of solvent from about 5 to 30% by volume of the reactor volume in the presence of a polymerization catalyst able to give the X.sub.2 and/or X.sub.4 parameters, lower less than or equal to 0.02, X.sub.2 and X.sub.4 representing the fraction of uninterrupted methylenic sequences of 2 and 4 methylenic groups between two successive methyl or methylene groups respectively in the polymeric chain, as compared with the uninterrupted total sequences of methylene groups determined by .sup.13 C-NMR; b) Conveying the reaction slurry into a flash pipe for the evaporation of the unreacted monomers and of minimum quantities of solvent; c) The polymeric part with the quantity of solvent of the same type or different as above, so as to obtain the desired polymer concentrations, and deactivation of the catalyst by bubbling of wet air stream.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.