Process for producing propylene copolymers with low VOC content
US11421055B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 10, 2018 |
| Grant date | Aug 23, 2022 |
| Priority date | — |
| Expiry date | Aug 16, 2038 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08F4/6494
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A process comprising polymerizing propylene and an olefin comonomer selected from C2 or C4-C8 with a Ziegler Natta catalyst system and hydrogen in a single gas-phase reactor, to form a propylene polymer, at a temperature range of from 78 to 92° C. with a H2/C3 molar ratio of 0.005 to 0.25, the catalyst system comprising: a solid catalyst component comprising a transition metal compound, a Group 2 metal compound, an internal electron donor comprising a substituted phenylene aromatic di ester; an activity limiting agent; an organo-aluminum compound; and an external electron donor composition comprising at least one silane, wherein if the olefin comonomer is ethylene it is present in the propylene polymer in an amount from 1.0-7.0 wt % based on the total weight of the propylene polymer, and if the olefin comonomer is C4-C8, it is present in an amount from 1.0-15.0 mol % based on the total amount of the propylene polymer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.