US4369295A
Expired / Lapsed
US
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Impregnated second valence chromium compound in supported catalyst
Assignee: Phillips Petroleum Co
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Filing: 1981-11-03
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Granted: 1983-01-18
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Expires: 2001-11-03
Abstract
Abstract A chromium catalyst supported on a silica-containing base is prepared having chromium present in both the hexavalent state and a lower valent state by anhydrously impregnating a second chromium compound onto the base which already has a chromium compound having a different chromium valence than said second chromium compound. For instance, a silica titanium cogel containing a chromium compound calcined to give hexavalent chromium can be anhydrously impregnated with a pi -bonded organochromium compound such as dibenzene chromium or dicumene chromium. Resulting polymers have broad molecular weight distribution and can be made in slurry systems at a sufficiently high melt flow to be useful in applications such as blow molding of bottles and other hollow articles.
Inventors
- 👤 Max P. McDaniel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 09:54
CPC Classifications
C; C08; C08F; C08F10/00
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
133 words
A polymerization process comprising contacting at least one mono-1-olefin having 2 to 8 carbon atoms per molecule with a catalyst having chromium present in both the hexavalent state and a lower valence state, said catalyst being produced by a process comprising forming a silica-containing support containing hexavalent chromium, thereafter as a separate step anhydrously impregnating said support with a chromium component in an anhydrous solvent wherein the chromium has a valence of less than 6 , and thereafter removing said solvent by gentle heating at a temperature of no more than about 100° C. and recovering said catalyst as the finished product of the process and wherein a weight ratio of said hexavalent chromium to said chromium having a valence of less than 6 is within the range of about 0.1:1 to 10:1.
Claim 2
Dependent Claim
133 words
A polymerization process comprising contacting at least one mono-1-olefin having 2 to 8 carbon atoms per molecule with a catalyst having chromium present in both the hexavalent state and a lower valence state, said catalyst being produced by a process comprising forming a silica-containing support containing hexavalent chromium, thereafter as a separate step anhydrously impregnating said support with a chromium component in an anhydrous solvent wherein the chromium has a valence of less than 6 , and thereafter removing said solvent by gentle heating at a temperature of no more than about 100° C. and recovering said catalyst as the finished product of the process and wherein a weight ratio of said hexavalent chromium to said chromium having a valence of less than 6 is within the range of about 0.1:1 to 10:1.
Claim 3
Dependent Claim
17 words
A method according to claim 1 wherein said mono-1-olefin is selected from ethylene, propylene, 1-butene, and 1-hexene.
Claim 4
Dependent Claim
27 words
A method according to claim 2 comprising in addition recovering a polymer from said polymerization process, wherein said polymer has a melt index of at least 0.1.
Claim 5
Dependent Claim
11 words
A method according to claim 1 wherein said mono-1-olefin comprises ethylene.
Claim 6
Dependent Claim
75 words
A method according to claim 1 wherein said chromium component having a valence of less than 6 is a zerovalent chromium compound, wherein a weight ratio of said hexavalent chromium to said chromium having a valence of less than 6 is within the range of about 0.5:1 to about 3:1 and wherein a total amount of chromium present is within the range of 0.01 to 10 weight percent based on the weight of said support.
Claim 7
Dependent Claim
14 words
A method according to claim 1 wherein said silica-containing support is a silica-titania cogel.
Claim 8
Dependent Claim
25 words
A method according to claim 1 wherein said chromium component having a valence of less than 6 is selected from dibenzene chromium and dicumene chromium.
Claim 9
Dependent Claim
44 words
A method according to claim 1 wherein said anhydrous impregnation is carried out using n-hexane as a solvent and wherein said solvent is removed by heating at said temperature of no more than about 100° C. under a vacuum or in an inert atmosphere.
Claim 10
Dependent Claim
41 words
A method according to claim 1 wherein said silica-containing support containing a hexavalent chromium compound is formed by incorporating a chromium compound having a valence of lower than 6 with said silica-containing support and thereafter calcining in the presence of oxygen.
Claim 11
Dependent Claim
19 words
A method according to claim 1 wherein said anhydrous impregnation is carried out in the substantial absence of oxygen.
Claim 12
Dependent Claim
130 words
A polymerization process comprising contacting at least one mono-1-olefin having 2 to 8 carbon atoms per molecule with a catalyst having chromium present in both the hexavalent state and a lower valence state, said catalyst being produced by a process consisting essentially of forming a dried silica-containing support containing a chromium compound wherein the chromium has a valence of less than 6, thereafter as a separate step anhydrously impregnating said support with a hexavalent chromium compound as a solution in an anhydrous solvent and thereafter removing said solvent by gentle heating at a temperature of not more than about 100° C. and wherein a weight ratio of said hexavalent chromium to said chromium having a valence of less than 6 is within the range of from about 0.1:1 to 10:1.
Claim 13
Dependent Claim
130 words
A polymerization process comprising contacting at least one mono-1-olefin having 2 to 8 carbon atoms per molecule with a catalyst having chromium present in both the hexavalent state and a lower valence state, said catalyst being produced by a process consisting essentially of forming a dried silica-containing support containing a chromium compound wherein the chromium has a valence of less than 6, thereafter as a separate step anhydrously impregnating said support with a hexavalent chromium compound as a solution in an anhydrous solvent and thereafter removing said solvent by gentle heating at a temperature of not more than about 100° C. and wherein a weight ratio of said hexavalent chromium to said chromium having a valence of less than 6 is within the range of from about 0.1:1 to 10:1.
Claim 14
Dependent Claim
17 words
A method according to claim 11 wherein said mono-1-olefin is selected from ethylene, propylene, 1-butene, and 1-hexene.
Claim 15
Dependent Claim
26 words
A method according to claim 12 comprising in addition recovering polymer from said polymerization process, wherein said polymer has a melt index of at least 0.1.
Claim 16
Dependent Claim
11 words
A method according to claim 11 wherein said mono-1-olefin comprises ethylene.
Claim 17
Dependent Claim
75 words
A method according to claim 11 wherein said chromium compound having a valence of less than 6 is a zerovalent chromium compound, wherein a weight ratio of said hexavalent chromium to said chromium having a valence of less than 6 is within the range of about 0.5:1 to about 3:1 and wherein a total amount of chromium present is within the range of 0.01 to 10 weight percent based on the weight of said support.
Claim 18
Dependent Claim
25 words
A method according to claim 11 wherein said chromium compound having a valence of less than 6 is selected from dicumene chromium and dibenzene chromium.
Claim 19
Dependent Claim
15 words
A method according to claim 1 wherein said hexavalent chromium compound is tertiary butyl chromate.
Claim 20
Dependent Claim
14 words
A method according to claim 11 wherein said hexavalent chromium compound is chromium trioxide.
Claim 21
Dependent Claim
38 words
A method according to claim 1 wherein said chromium compound having a valence of less than 6 is combined with said support by anhydrous impregnation and wherein said anhydrous impregnations are carried out utilizing n-hexane as a solvent.
Claim 22
Dependent Claim
18 words
A method according to claim 11 wherein said impregnation is carried out in the substantial absence of oxygen.
Claim 23
Dependent Claim
41 words
A method according to claim 1 wherein said hexavalent chromium compound is tertiary butyl chromate, said chromium compound having a valence of less than 6 is selected from dibenzene chromium and dicumene chromium and wherein said support is a silica-titania cogel.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-01-17 | 1986-07-19 | 1987-01-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-01-17 | 1990-07-19 | 1991-01-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-01-17 | 1994-07-19 | 1995-01-18 | $7700.00 | Window Closed / Lapsed |