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US4009327A
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Polymerization of olefins
Assignee: Phillips Petroleum Co
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Filing: 1974-12-10
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Granted: 1977-02-22
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Expires: 1994-12-10
Abstract
Abstract Olefin polymerization process employing a catalyst formed of a silica produced using lithium silicate. Ethylene polymers of higher melt index are produced than when sodium silicate is employed.
Inventors
- 👤 Donald R. Witt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 18:22
CPC Classifications
B; B01; B01J; B01J23/00; B01J23/02; B01J23/04; C; C08; C08F; C08F10/00
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
92 words
A method for polymerizing olefins which comprises contacting an olefin-containing stream with a chromium oxide catalyst active for olefin polymerization and comprising a silica-containing composition prepared by: a. introducing an aqueous lithium silicate solution into an aqueous acid solution to form a hydrogel; b. aging the hydrogel; c. washing the hydrogel to reduce the alkali metal content of the hydrogel; d. contacting the hydrogel with a normally liquid, oxygen-containing, water-soluble organic compound to separate water from said hydrogel and to form a xerogel; and e. recovering the xerogel as the silica-containing composition.
Claim 2
Independent Claim
92 words
A method for polymerizing olefins which comprises contacting an olefin-containing stream with a chromium oxide catalyst active for olefin polymerization and comprising a silica-containing composition prepared by: a. introducing an aqueous lithium silicate solution into an aqueous acid solution to form a hydrogel; b. aging the hydrogel; c. washing the hydrogel to reduce the alkali metal content of the hydrogel; d. contacting the hydrogel with a normally liquid, oxygen-containing, water-soluble organic compound to separate water from said hydrogel and to form a xerogel; and e. recovering the xerogel as the silica-containing composition.
Claim 3
Dependent Claim
149 words
A method for polymerizing olefins which comprises contacting an olefin-containing stream with a chromium-containing catalyst active for olefin polymerization and comprising a silica-containing composition prepared by the method of claim 1 wherein a. said aqueous lithium silicate is introduced into said acid solution at a rate of addition of from about 0.1 to about 15 weight percent of the total quantity of the lithium silicate added per minute; b. said hydrogel is aged at a temperature within the range of from about 70° to 90° C for a period greater than one hour; c. the aged hydrogel is contacted with ethyl acetate to form a mixture and said mixture is azeotropically distilled to form said xerogel; d. said xerogel is impregnated with t-butyl chromate to produce a silica containing about 1 weight percent chromium; and e. the chromium-containing silica is activated to produce a catalyst active in ethylene polymerization.
Claim 4
Dependent Claim
20 words
The method of claim 1 in which said aqueous lithium silicate solution comprises at least 0.5 weight percent lithium monoxide.
Claim 5
Dependent Claim
15 words
The method of claim 1 in which said aqueous silicate solution contains a titanium-containing compound.
Claim 6
Dependent Claim
17 words
The method of claim 1 in which a titanium-containing compound is contained in said aqueous acid solution.
Claim 7
Dependent Claim
11 words
A method according to claim 1 wherein the olefin is ethylene.
Claim 8
Dependent Claim
11 words
A method according to claim 1 wherein the olefin is propylene.
Claim 9
Dependent Claim
11 words
A method according to claim 2 wherein the olefin is ethylene.
Claim 10
Dependent Claim
11 words
A method according to claim 2 wherein the olefin is propylene.
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) | 1980-02-22 | 1980-08-23 | 1981-02-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-02-22 | 1984-08-23 | 1985-02-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-02-22 | 1988-08-23 | 1989-02-22 | $7700.00 | Window Closed / Lapsed |