Patent US4419394A successfully refreshed from Google Patents.
US4419394A
Expired / Lapsed
US
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Catalyst and method of making the same
Assignee: Texaco Inc
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Filing: 1981-11-16
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Granted: 1983-12-06
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Expires: 2001-11-16
Abstract
Abstract A coating solution, useful in the process of coating a substrate with an alumina film, can be formed by adding to an alkali aluminate solution a sufficient quantity of an alumina gel which is a precipitate formed by the reaction of aluminum sulfate with aqueous ammonium hydroxide at a pH of between about 6 and 8. The added alumina gel effects a coating of an adherent alumina trihydrate film on a substrate upon the contacting of the substrate with the coating solution.
Inventors
- 👤 John M. Crone, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 17:45
CPC Classifications
C; C01; C01F; C01F7/00; C01F7/02; C01F7/34; B; B01; B01D; B01D53/00; B01D53/34; B01D53/74; B01D53/86; B01J; B01J37/00; B01J37/02; B01J37/0215; B01J37/024; C03; C03C; C03C17/00; C03C17/22; C03C17/23; C03C17/25; C04; C04B; C04B41/00; C04B41/45; C04B41/50; C04B41/5025; C04B41/5031; C04B41/80; C04B41/81; C04B41/85; C04B41/87; C03C2217/00; C03C2217/20; C03C2217/21; C03C2217/214; C03C2218/00; C03C2218/10; C03C2218/11; C03C2218/113
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
126 words
A method of coating an article comprising the steps of forming a coating solution by adding a sufficient quantity of an alumina gel to an alkali aluminate solution to effect a coating of an adherent alumina trihydrate film on a substrate upon the contacting of the substrate with said coating solution, said alumina gel comprising an amorphous precipitate formed by the reaction of aluminum sulfate and aqueous ammonium hydroxide at a pH of between about 6 and 8, said alumina gel not completely dissolving into said solution and not crystallizing out of said solution prior to forming said adherent alumina trihydrate film; and contacting a substrate with said coating solution for a period of time sufficient to form an adherent alumina trihydrate film on said substrate.
Claim 2
Independent Claim
126 words
A method of coating an article comprising the steps of forming a coating solution by adding a sufficient quantity of an alumina gel to an alkali aluminate solution to effect a coating of an adherent alumina trihydrate film on a substrate upon the contacting of the substrate with said coating solution, said alumina gel comprising an amorphous precipitate formed by the reaction of aluminum sulfate and aqueous ammonium hydroxide at a pH of between about 6 and 8, said alumina gel not completely dissolving into said solution and not crystallizing out of said solution prior to forming said adherent alumina trihydrate film; and contacting a substrate with said coating solution for a period of time sufficient to form an adherent alumina trihydrate film on said substrate.
Claim 3
Independent Claim
108 words
A method of coating an article comprising the steps of contacting a substrate with an alkali aluminate solution which does not substantially cost said substrate with an alumina trihydrate film; and adding a sufficient quantity of an alumina gel to the alkali aluminate solution to cause an adherent alumina trihydrate film to form on said substrate, said alumina gel comprising an amorphous precipitate formed by the reaction of aluminum sulfate and aqueous ammonium hydroxide at a pH of between about 6 and 8, and said alumina gel not completely dissolving into said solution and not crystallizing out of said solution prior to forming said adherent alumina trihydrate film.
Claim 4
Independent Claim
108 words
A method of coating an article comprising the steps of contacting a substrate with an alkali aluminate solution which does not substantially cost said substrate with an alumina trihydrate film; and adding a sufficient quantity of an alumina gel to the alkali aluminate solution to cause an adherent alumina trihydrate film to form on said substrate, said alumina gel comprising an amorphous precipitate formed by the reaction of aluminum sulfate and aqueous ammonium hydroxide at a pH of between about 6 and 8, and said alumina gel not completely dissolving into said solution and not crystallizing out of said solution prior to forming said adherent alumina trihydrate film.
Claim 5
Dependent Claim
24 words
The method of claim 2 wherein the step of adding the alumina gel comprises dispersing the alumina gel throughout the coating solution by agitation.
Claim 6
Dependent Claim
35 words
The method of claim 2 wherein the addition of the alumina gel to the alkali aluminate solution increases the aluminum to sodium mole ratio of the alkali aluminate solution to between about 0.65 and 0.9.
Claim 7
Dependent Claim
33 words
The method of claim 4 wherein the addition of the alumina gel to the alkali aluminate solution increases the aluminum to sodium mole ratio of the solution to between about 0.7 and 0.8.
Claim 8
Dependent Claim
31 words
The method of claim 2 wherein the aluminum to sodium mole ratio in the alkali aluminate solution prior to the addition of the alumina gel is not more than about 0.6.
References Cited (Backward Citations)
US3227659A
Cited
US3231520A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-12-05 | 1987-06-06 | 1987-12-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-12-05 | 1991-06-06 | 1991-12-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-12-05 | 1995-06-06 | 1995-12-06 | $7700.00 | Window Closed / Lapsed |