Production of multimodal polyethylene
US6218472A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 24, 1999 |
| Grant date | Apr 17, 2001 |
| Priority date | — |
| Expiry date | Sep 24, 2019 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08L2314/06
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A process for the preparation of polyethylene resins having a multimodal molecular weight distribution which comprises: PA1 (i) contacting ethylene monomer and a comonomer comprising an alpha-olefin having from 3 to 10 carbon atoms with a first catalyst system in a first reactor under first polymerization conditions in a slurry process to produce a first polyethylene having a first molecular weight an HLMI of not more than 0.5 g/10 min and a first density of not more than 0.925 g/ml and the first catalyst system comprising (a) a first metallocene catalyst of general formula R"(CpR.sub.m)(Cp'R'.sub.n)MQ.sub.2, wherein Cp is a cyclopentadienyl moiety, Cp' is a substituted or unsubstituted fluorenyl ring; each R is independently hydrogen or hydrocarbyl having 1 to 20 carbon atoms in which 0.ltoreq.m.ltoreq.4; each R' is independently hydrocarbyl having 1 to 20 carbon atoms in which 0.ltoreq.n.ltoreq.8, R" is a bridge which comprises a C.sub.1 -C.sub.20 alkylene radical, a dialkyl germanium or silicon or siloxane, or an alkyl phosphine or amine radical, which bridge is substituted or unsubstituted, M is a Group IVB transition metal or vanadium and each Q is hydrocarbyl having 1 to 20 c…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.