US3870693A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Homopolymerization or copolymerization of ethylene
Assignee: Individual
•
Filing: 1972-01-26
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Granted: 1975-03-11
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Expires: 1992-01-26
Abstract
Abstract A process for the polymerization of ethylene or mixtures of ethylene and propene and/or butene-1 by means of a low-pressure catalyst which has been prepared by heating a carrier material in an oxygen-containing stream of gas to high temperatures, which carrier material contains silica and alumina and is impregnated with a chromium compound. The catalyst has been exhaustively extracted with water after its manufacture and then dried and reheated to high temperatures in an oxygen-containing stream of gas. High yields of polymer showing a particularly low content of chromium are obtained.
Inventors
- 👤 Karl Wisseroth
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 09:14
CPC Classifications
C; C08; C08F; C08F10/00
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
108 words
IN A PROCESS FOR THE POLYMERIZATION OF ETHYLENE AND MIXTURES OF ETHYLENE AND UP TO 50 PERCENT BY WEIGHT OF PROPENE AND/OR BUTENE-1 WITH THE AID OF A LOW-PRESSURE CATALYST AND WHEREIN SAID CATALYST IS FORMED BY HEATING A CARRIER MATERIAL CONTAINING SILICA AND/OR ALUMINA AND IMPREGNATED WITH A CHROMIUM COMPOUND TO TEMPERATURES ABOVE 300*C IN AN OXYGENCONTAINING STREAM OF GAS TO ACTIVATE SAID CATALYST, THE IMPROVEMENT WHICH CONSISTS ESSENTIALLY OF EXHAUSTIVELY EXTRACTING SAID ACTIVATED CATALYST WITH WATER TO REMOVE WATER SOLUBLE CHROMIUM THEREFROM, DRYING SAID CATALYST, AND THEREAFTER REACTIVATING SAID CATALYST BY REHEATING SAID CATALYST IN AN OXYGENCONTAINING STREAM OF GAS TO TEMPERATURES BETWEEN 250* AND 400*C.
Claim 2
Dependent Claim
108 words
IN A PROCESS FOR THE POLYMERIZATION OF ETHYLENE AND MIXTURES OF ETHYLENE AND UP TO 50 PERCENT BY WEIGHT OF PROPENE AND/OR BUTENE-1 WITH THE AID OF A LOW-PRESSURE CATALYST AND WHEREIN SAID CATALYST IS FORMED BY HEATING A CARRIER MATERIAL CONTAINING SILICA AND/OR ALUMINA AND IMPREGNATED WITH A CHROMIUM COMPOUND TO TEMPERATURES ABOVE 300*C IN AN OXYGENCONTAINING STREAM OF GAS TO ACTIVATE SAID CATALYST, THE IMPROVEMENT WHICH CONSISTS ESSENTIALLY OF EXHAUSTIVELY EXTRACTING SAID ACTIVATED CATALYST WITH WATER TO REMOVE WATER SOLUBLE CHROMIUM THEREFROM, DRYING SAID CATALYST, AND THEREAFTER REACTIVATING SAID CATALYST BY REHEATING SAID CATALYST IN AN OXYGENCONTAINING STREAM OF GAS TO TEMPERATURES BETWEEN 250* AND 400*C.
Claim 3
Dependent Claim
108 words
In a process for the polymerization of ethylene and mixtures of ethylene and up to 50 percent by weight of propene and/or butene-1 with the aid of a low-pressure catalyst and wherein said catalyst is formed by heating a carrier material containing silica and/or alumina and impregnated with a chromium compound to temperatures above 300*C in an oxygen-containing stream of gas to activate said catalyst, the improvement which consists essentially of exhaustively extracting said activated catalyst with water to remove water soluble chromium therefrom, drying said catalyst, and thereafter reactivating said catalyst by reheating said catalyst in an oxygen-containing stream of gas to temperatures between 250* and 400*C.
Claim 4
Dependent Claim
108 words
In a process for the polymerization of ethylene and mixtures of ethylene and up to 50 percent by weight of propene and/or butene-1 with the aid of a low-pressure catalyst and wherein said catalyst is formed by heating a carrier material containing silica and/or alumina and impregnated with a chromium compound to temperatures above 300*C in an oxygen-containing stream of gas to activate said catalyst, the improvement which consists essentially of exhaustively extracting said activated catalyst with water to remove water soluble chromium therefrom, drying said catalyst, and thereafter reactivating said catalyst by reheating said catalyst in an oxygen-containing stream of gas to temperatures between 250* and 400*C.
Claim 5
Dependent Claim
30 words
A process as set forth in claim 1 wherein the carrier material is impregnated with a chromium compound in an amount of about from 2 to 3 percent by weight.
Claim 6
Dependent Claim
31 words
A process as set forth in claim 2 wherein from about 90 to 95 percent by weight of the chromium initially contained in the catalyst is removed by extraction with water.
Claim 7
Dependent Claim
24 words
A process as set forth in claim 3 wherein the carrier material is impregnated with about 2.5 percent by weight of a chromium compound.
Claim 8
Dependent Claim
16 words
A process as set forth in claim 1 wherein a homopolymer of ethylene is produced. 1.
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) | 1978-03-10 | 1978-09-09 | 1979-03-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-10 | 1982-09-09 | 1983-03-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-10 | 1986-09-09 | 1987-03-11 | $7700.00 | Window Closed / Lapsed |