Patent US4081576A successfully refreshed from Google Patents.
US4081576A
Expired / Lapsed
US
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Process for producing an adherent metal oxide coating on a solid body
Assignee: Evonik Operations GmbH
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Filing: 1976-07-07
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Granted: 1978-03-28
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Expires: 1996-07-07
Abstract
Abstract An improvement in producing an adherent metal oxide coating on a solid body comprises incorporating a nitrogen-containing polymer in a dispersion of the metal oxide into which the body is dipped. The pH of the dispersion is controlled in order to stabilize the dispersion. The body can then be dried. The invention is especially useful for applying a metal oxide coating to a ceramic material employed as a catalyst carrier for automotive exhaust gas purification.
Inventors
- 👤 Jorg Hensel
- 👤 Edgar Koberstein
- 👤 Eduard Lakatos
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 11:38
CPC Classifications
C; C04; C04B; C04B41/00; C04B41/009; B; B01; B01J; B01J37/00; B01J37/02; B01J37/03; B01J37/031; C04B41/45; C04B41/50; C04B41/5025; C04B41/80; C04B41/81; C04B41/85; C04B41/87
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
121 words
In an improved process for producing an adherent coating of a metal oxide selected from the group consisting of Al 2 O 3 or TiO 2 on a solid, chemically inert, porous, ceramic carrier for a catalyst by dispersing in water said metal oxide in pulverized form, dipping said carrier into the resulting dispersion, and drying said carrier, wherein the improvement comprises incorporating in said dispersion about 0.001 to about 5% by weight of a nitrogen-containing polymer selected from the group consisting of a polyethylene imine or an ammonium salt of a carboxylic acid polymer, and maintaining a pH of about 7 in said dispersion, wherein said metal oxide is comprised of particles having a grain diameter greater than 1 μm.
Claim 2
Dependent Claim
121 words
In an improved process for producing an adherent coating of a metal oxide selected from the group consisting of Al 2 O 3 or TiO 2 on a solid, chemically inert, porous, ceramic carrier for a catalyst by dispersing in water said metal oxide in pulverized form, dipping said carrier into the resulting dispersion, and drying said carrier, wherein the improvement comprises incorporating in said dispersion about 0.001 to about 5% by weight of a nitrogen-containing polymer selected from the group consisting of a polyethylene imine or an ammonium salt of a carboxylic acid polymer, and maintaining a pH of about 7 in said dispersion, wherein said metal oxide is comprised of particles having a grain diameter greater than 1 μm.
Claim 3
Dependent Claim
27 words
Process according to claim 1, wherein said metal oxide is γ-alumina in an amount up to about 50 weight percent, related to the weight of said dispersion.
Claim 4
Dependent Claim
19 words
Process according to claim 2 wherein said carrier is comprised of cordierite, mullite or γ--Al 2 O 3 .
Claim 5
Dependent Claim
14 words
Process according to claim 1, wherein said dispersion contains methanol, ethanol, or mixtures thereof.
Claim 6
Dependent Claim
22 words
Process according to claim 3 wherein said pH is maintained by additions of ammonia or a C 1 -C 3 carboxylic acid.
Claim 7
Dependent Claim
16 words
Process according to claim 5, wherein excess dispersion on said carrier is removed prior to drying.
Claim 8
Dependent Claim
29 words
Process according to claim 1 wherein said nitrogen containing polymer is in an amount of about 0.01 to about 2% by weight, related to the weight of said dispersion.
Claim 9
Dependent Claim
29 words
Process according to claim 1 wherein said nitrogen containing polymer is in an amount of about 0.1 to about 1% by weight, related to the weight of said dispersion.
References Cited (Backward Citations)
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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) | 1981-03-27 | 1981-09-26 | 1982-03-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-03-27 | 1985-09-26 | 1986-03-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-03-27 | 1989-09-26 | 1990-03-28 | $7700.00 | Window Closed / Lapsed |