Olefin polymerization catalysts with specific silica supports
US5895770A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 21, 1997 |
| Grant date | Apr 20, 1999 |
| Priority date | — |
| Expiry date | Mar 21, 2017 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08F4/65925
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A transition metal containing catalyst having a silica-support is provided for the production of polyolefins from .alpha.-olefins that can be converted to polymer films, preferably thin films of polyolefin, which have lower defects resulting from a decreased presence of silica-containing residues from the catalyst. The catalyst has a porous silica support component and a catalytic component which may include, but is not limited to, such materials as chromium, magnesium-titanium (Ziegler-Natta type) or metallocene compounds (Metallocene catalyst type). The porous silica component of the catalyst has an average pore volume of from about 2.5 to about 3.5 ml/g and a surface area of 200 to 400 m.sup.2 /g and preferably 250 to 350 m.sup.2 /g. The average pore diameter ranges from about 285 to about 700 Angstroms and preferably 500-700 Angstroms for porous silica components having surface areas of 200 m.sup.2 /g and preferably 285-400 Angstroms for porous silica components having surface areas of 350 m.sup.2 /g. Preferably, the average particle size of the silica component may range from 44 to about 150 microns in diameter.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.