US4384086A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Large pore volume olefin polymerization catalysts
Assignee: Phillips Petroleum Co
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Filing: 1981-07-21
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Granted: 1983-05-17
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Expires: 2001-07-21
Abstract
Abstract Large pore volume (≧1.4 cc/g) silica is obtained by slowly drying an acidic (pH ≦3.5) silica hydrogel. The gel is useful in connection with chromium as an ethylene polymerization catalyst.
Inventors
- 👤 Max P. McDaniel
- 👤 John J. Meister
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 05:40
CPC Classifications
C; C08; C08F; C08F10/00; C08F10/02
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
137 words
A polymerization process comprising contacting ethylene or ethylene together with one of more 1-olefins under polymerization conditions with a catalyst obtained by a process comprising: (a) contacting an aqueous alkali metal silicate comprising solution with an acid to produce an alkali-containing hydrogel, (b) removing alkali from said alkali-containing hydrogel by washing with water to obtain a purified silica-containing hydrogel, (c) admixing the so obtained purified silica-containing hydrogel with acid to obtain an acidified silica-containing hydrogel having a pH of 3.5 or less, (d) drying said acidified silica-containing hydrogel until essentially all water is evaporated, to obtain a xerogel having a higher pore volume than a xerogel obtained by drying the not acidified hydrogel (e) prior to, during or after said drying utilizing a chromium source to obtain a chromium-containing gel, and (f) calcining said chromium containing gel.
Claim 2
Dependent Claim
137 words
A polymerization process comprising contacting ethylene or ethylene together with one of more 1-olefins under polymerization conditions with a catalyst obtained by a process comprising: (a) contacting an aqueous alkali metal silicate comprising solution with an acid to produce an alkali-containing hydrogel, (b) removing alkali from said alkali-containing hydrogel by washing with water to obtain a purified silica-containing hydrogel, (c) admixing the so obtained purified silica-containing hydrogel with acid to obtain an acidified silica-containing hydrogel having a pH of 3.5 or less, (d) drying said acidified silica-containing hydrogel until essentially all water is evaporated, to obtain a xerogel having a higher pore volume than a xerogel obtained by drying the not acidified hydrogel (e) prior to, during or after said drying utilizing a chromium source to obtain a chromium-containing gel, and (f) calcining said chromium containing gel.
Claim 3
Dependent Claim
23 words
A process in accordance with claim 1 comprising aging said purified hydrogel prior to the mixing of said purified hydrogel with said acid.
Claim 4
Dependent Claim
25 words
A process in accordance with claim 1 comprising dissolving said chromium source in said acid and mixing the solution so obtained and said purified hydrogel.
Claim 5
Dependent Claim
37 words
A process in accordance with claim 1 comprising mixing the dried gel obtained in step (d) and a solution of a chromium compound in an inert organic solvent and removing said solvent to obtain said chromium-containing gel.
Claim 6
Dependent Claim
19 words
A process in accordance with claim 1 wherein said silica-containing hydrogel is essentially alkali-free and consists essentially of silica.
Claim 7
Dependent Claim
36 words
A process in accordance with claim 1 wherein said polymerization is carried out in the presence of an inert hydrocarbon fluid and under temperature and pressure conditions to keep the olefins essentially in the liquid state.
Claim 8
Dependent Claim
24 words
A process in accordance with claim 1 wherein said step (d) is carried out under a radiant heat source or in a drying oven.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-05-16 | 1986-11-15 | 1987-05-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-05-16 | 1990-11-15 | 1991-05-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-05-16 | 1994-11-15 | 1995-05-17 | $7700.00 | Window Closed / Lapsed |