US3887491A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of preparing silver catalyst
Assignee: Dow Chemical Co
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Filing: 1973-11-05
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Granted: 1975-06-03
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Expires: 1993-11-05
Abstract
Abstract Silver catalysts of uniform fine particle size, having improved activity in the oxidation of ethylene to ethylene oxide, have been prepared by depositing silver or a silver compound on a carrier in the presence of dispersing agents selected from certain natural gums, e.g. karaya or gelatin.
Inventors
- 👤 Enrique Garcia Ramirez
- 👤 Lowell Curtis Thomas
- 👤 William Earl Fry
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 03:15
CPC Classifications
C; C07; C07D; C07D301/00; C07D301/02; C07D301/03; C07D301/04; C07D301/08; C07D301/10; B; B01; B01J; B01J23/00; B01J23/38; B01J23/48; B01J23/50; Y; Y02; Y02P; Y02P20/00; Y02P20/50; Y02P20/52
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
88 words
In a process for making a supported silver catalyst in which a soluble silver compound is impregnated onto a support from an aqueous solution thereof, subsequently dried and reduced to metallic sIlver, the improvement of adding to said aqueous solution a natural gum selected from the group consisting of karaya, ghatti, tragacanth, guar, saponin, locust bean, psyllium seed, quince seed, agar, algin, carrageenan, furcellaran, pectin, gelatin and casein in an amount of from about 0.5 to about 2.5 percent based on the total weight of said aqueous solution.
Claim 2
Dependent Claim
88 words
In a process for making a supported silver catalyst in which a soluble silver compound is impregnated onto a support from an aqueous solution thereof, subsequently dried and reduced to metallic sIlver, the improvement of adding to said aqueous solution a natural gum selected from the group consisting of karaya, ghatti, tragacanth, guar, saponin, locust bean, psyllium seed, quince seed, agar, algin, carrageenan, furcellaran, pectin, gelatin and casein in an amount of from about 0.5 to about 2.5 percent based on the total weight of said aqueous solution.
Claim 3
Dependent Claim
87 words
IN A PROCESS FOR MAKING A SUPPORTED SILVER CATALYST IN WHICH A SOLUBLE SILVER COMPOUND IS IMPREGNATED ONTO A SUPPORT FROM AN AQUEOUS SOLUTION THEREOF, SUBSEQUENTLY DRIED AND REDUCED TO METALLIC SILVER, THE IMPROVEMENT OF ADING TO SAID AQUEOUS SOLUTION A NATURAL GUM SELECTED FROM THEGROUP CONSISTING OF KARAYA, GHATTI, TRAGANTH, GUAR, SAPONIN, LOCUST BEAN, PSYLLIUM SEED, QUINCE SEED, AGAR, LAGIN,, CARRAGEENAN FURCELLARAN, PECTIN, GELATIN AN CASEIN IN AN AMOUNT OF FROM ABOUT 0.5 TO ABOUT 2.5 PERCENT BASED ON THE TOTAL WEIGHT OF SAID AQUEOUS SOLUTION.
Claim 4
Dependent Claim
87 words
IN A PROCESS FOR MAKING A SUPPORTED SILVER CATALYST IN WHICH A SOLUBLE SILVER COMPOUND IS IMPREGNATED ONTO A SUPPORT FROM AN AQUEOUS SOLUTION THEREOF, SUBSEQUENTLY DRIED AND REDUCED TO METALLIC SILVER, THE IMPROVEMENT OF ADING TO SAID AQUEOUS SOLUTION A NATURAL GUM SELECTED FROM THEGROUP CONSISTING OF KARAYA, GHATTI, TRAGANTH, GUAR, SAPONIN, LOCUST BEAN, PSYLLIUM SEED, QUINCE SEED, AGAR, LAGIN,, CARRAGEENAN FURCELLARAN, PECTIN, GELATIN AN CASEIN IN AN AMOUNT OF FROM ABOUT 0.5 TO ABOUT 2.5 PERCENT BASED ON THE TOTAL WEIGHT OF SAID AQUEOUS SOLUTION.
Claim 5
Dependent Claim
64 words
The method of claim 1 wherein a water soluble promoter compound of a metal selected from the group consisting of Na, Ca, Au, Sn and Ba, said compound being convertible to the oxide on heating in air, is added to the aqueous impregnating solution in an amount so as to provide from about 0.001 to about 1.0 percent based on the weight of silver.
Claim 6
Dependent Claim
78 words
In a process for making a supported silver catalyst wherein a soluble silver compound is impregnated onto a support from an aqueous solution thereof, subsequently dried and reduced to metallic silver the improvement of adding to said aqueous solution a mixture of gum arabic and gelatin in an amount of from about 0.5 to about 2.5 percent based on the total weight of said aqueous solution and wherein the proportion of gelatin to gum arabic is about 2:1.
Claim 7
Dependent Claim
78 words
In a process for making a supported silver catalyst wherein a soluble silver compound is impregnated onto a support from an aqueous solution thereof, subsequently dried and reduced to metallic silver the improvement of adding to said aqueous solution a mixture of gum arabic and gelatin in an amount of from about 0.5 to about 2.5 percent based on the total weight of said aqueous solution and wherein the proportion of gelatin to gum arabic is about 2:1.
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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) | 1978-06-02 | 1978-12-02 | 1979-06-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-06-02 | 1982-12-02 | 1983-06-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-06-02 | 1986-12-02 | 1987-06-03 | $7700.00 | Window Closed / Lapsed |