US4101445A
Expired / Lapsed
US
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Preparation of modified and activated chromocene catalysts for ethylene polymerization
Assignee: Union Carbide Corp
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Filing: 1976-09-22
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Granted: 1978-07-18
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Expires: 1996-09-22
Abstract
Abstract Ethylene polymerization catalysts are prepared by depositing a chromocene compound on a support with a titanium compound and activating the final blend at 300° C. to about 1000° C. A fluoriding agent can be optionally added where a narrower molecular weight distribution of the polyethylene to be obtained is desired. Catalysts with good reproducibility, when prepared by this method, show particular utility in production of polyethylene by a fluid bed process.
Inventors
- 👤 Isaac Jacob Levine
- 👤 Frederick John Karol
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 02:19
CPC Classifications
C; C08; C08F; C08F10/00; C08F10/02
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
231 words
A method for preparing a catalyst for the consistent polymerization of ethylene which comprises the steps of: (1) drying an inorganic oxide catalyst support, having a high surface area, selected from the group consisting of a alumina, thoria, silica, zirconia, and mixtures thereof at a temperature of about 100° C. to about 800° C.; (2) slurrying the dried support obtained in step (1) with a substantially anhydrous normally liquid hydrocarbon; (3) blending the slurry obtained in step (2) with a solution of a chromocene compound having the formula: ##STR2## wherein each of Y and Y' is a hydrocarbon radical having 1 to about 20 carbon atoms and each n and n' has a value of 0 to 5, in a normally liquid hydrocarbon and a titanium compound which is soluble in said hydrocarbon and is calcinable to TiO 2 whereby the resultant blend, exclusive of hydrocarbon, contains about 0.02 to about 3.0 weight % of elemental chromium and about 1.0 to about 10 weight % of elemental titanium; (4) removing the hydrocarbon leaving a solid residue; (5) adding to the residue from step (4) from 0 to about 2.5 weight % of a fluoridation agent calculated as F; and (6) heating the product from step (5) in a substantially anhydrous oxygen-containing atmosphere at a temperature of about 300° C. to about 1000° C. until an active ethylene polymerization catalyst is obtained.
Claim 2
Independent Claim
231 words
A method for preparing a catalyst for the consistent polymerization of ethylene which comprises the steps of: (1) drying an inorganic oxide catalyst support, having a high surface area, selected from the group consisting of a alumina, thoria, silica, zirconia, and mixtures thereof at a temperature of about 100° C. to about 800° C.; (2) slurrying the dried support obtained in step (1) with a substantially anhydrous normally liquid hydrocarbon; (3) blending the slurry obtained in step (2) with a solution of a chromocene compound having the formula: ##STR2## wherein each of Y and Y' is a hydrocarbon radical having 1 to about 20 carbon atoms and each n and n' has a value of 0 to 5, in a normally liquid hydrocarbon and a titanium compound which is soluble in said hydrocarbon and is calcinable to TiO 2 whereby the resultant blend, exclusive of hydrocarbon, contains about 0.02 to about 3.0 weight % of elemental chromium and about 1.0 to about 10 weight % of elemental titanium; (4) removing the hydrocarbon leaving a solid residue; (5) adding to the residue from step (4) from 0 to about 2.5 weight % of a fluoridation agent calculated as F; and (6) heating the product from step (5) in a substantially anhydrous oxygen-containing atmosphere at a temperature of about 300° C. to about 1000° C. until an active ethylene polymerization catalyst is obtained.
Claim 3
Dependent Claim
13 words
Method claimed in claim 1 wherein the inorganic oxide catalyst support is silica.
Claim 4
Dependent Claim
12 words
Method claimed in claim 1 wherein the chromocene compound is bis(cyclopentadienyl)chromium II.
Claim 5
Dependent Claim
65 words
Method claimed in claim 1 wherein the titanium compound has the formula (R').sub.n" Ti(OR').sub.m or (RO).sub.m Ti(OR').sub.n" wherein m has values of 1 to 4 inclusive, n" has values of 0 to 3 inclusive, m + n" = 4, R is a C 1 to C 12 alkyl, aryl or cycloalkyl group, and R' is R, cyclopentadienyl or C 2 to C 12 alkenyl groups.
Claim 6
Dependent Claim
19 words
Method claimed in claim 1 wherein the titanium compound has the formula TiX.sub.4 wherein X is a halogen atom.
Claim 7
Dependent Claim
18 words
Method claimed in claim 1 wherein about 0.05 to 1.0% by weight of a fluoridation agent is used.
Claim 8
Dependent Claim
17 words
Method claimed in claim 6 wherein the fluoridation agent is (NH 4 ) 2 SiF 6 .
Claim 9
Dependent Claim
27 words
Method claimed in claim 1 wherein the blend from step 5 is heated in step 6 at a temperature of about 300° C. to about 800° C.
Claim 10
Dependent Claim
10 words
Method claimed in claim 1 wherein the hydrocarbon is isopentane.
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) | 1981-07-17 | 1982-01-16 | 1982-07-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-07-17 | 1986-01-16 | 1986-07-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-07-17 | 1990-01-16 | 1990-07-18 | $7700.00 | Window Closed / Lapsed |