US4786476A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Gas sensor element using porously fired mass of titania
Assignee: Nissan Motor Co Ltd
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Filing: 1986-07-16
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Granted: 1988-11-22
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Expires: 2006-07-16
Abstract
Abstract The invention relates to a gas sensor element which utilizes a change in the electric resistance of a porously fired TiO 2 layer. To improve the speed of response of the gas sensor element, and also to strengthen the adhesion of the fired TiO 2 layer to a ceramic substrate, at least one kind of metal oxide which hardly undergoes solid phase reaction with TiO 2 and serves as a sintering suppressing agent, such as Er 2 O 3 , Sm 2 O 3 and/or In 2 O 3 , is added to TiO 2 in advance of firing. The speed of response is further enhanced by the addition of at least one kind of noble metal such as Pt and/or Rh to TiO 2 together with the sintering suppressing oxide(s).
Inventors
- 👤 Fumio Munakata
- 👤 Masayuki Touda
- 👤 Masaaki Uchida
- 👤 Fumio Yukawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 19:40
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/02; G01N27/04; G01N27/12
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
49 words
A gas sensor element comprising: a ceramic substrate; and a mixture of titanium dioxide and a sintering suppressing agent laminated on said ceramic substrate, said agent comprising at least one additional metal oxide selected from the group consisting of Er 2 O 3 and Sm 2 O 3 .
Claim 2
Dependent Claim
49 words
A gas sensor element comprising: a ceramic substrate; and a mixture of titanium dioxide and a sintering suppressing agent laminated on said ceramic substrate, said agent comprising at least one additional metal oxide selected from the group consisting of Er 2 O 3 and Sm 2 O 3 .
Claim 3
Dependent Claim
34 words
A gas sensor element according to claim 1, wherein the total amount of said at least one additional metal oxide is in the range from 0.01 to 10 mol % of said titanium dioxide.
Claim 4
Dependent Claim
22 words
A gas sensor element according to claim 1, wherein said mixture further comprises at least one noble metal of the platinum group.
Claim 5
Dependent Claim
33 words
A gas sensor element according to claim 3, wherein the total amount of said at least one noble metal is in the range from 0.01 to 10 mol % of said titanium dioxide.
Claim 6
Dependent Claim
18 words
A gas sensor element according to claim 4, wherein said at least one noble metal consists of Pt.
Claim 7
Dependent Claim
39 words
A gas sensor element according to claim 4, wherein said at least one noble metal is a combination of Pt and Rh, the molar ratio of said Pt to said Rh being in the range from 1:0.01 to 1:0.8.
Claim 8
Dependent Claim
14 words
A gas sensor element according to claim 1 wherein said ceramic substrate is alumina.
Claim 9
Dependent Claim
20 words
A gas sensor element according to claim 1, wherein said mixture consists essentially of titanium dioxide and said sintering agent.
Claim 10
Dependent Claim
22 words
A gas sensor element according to claim 1, wherein said ceramic substrate has a sintering temperature of about 1300° to 1400° C.
Claim 11
Dependent Claim
43 words
A gas sensor element according to claim 1, wherein said at least one additional metal oxide is present in an amount sufficient to suppress sintering at temperatures above about 1200° C. to an extent sufficient to improve gas permeability of sintered titanium dioxide.
Claim 12
Dependent Claim
55 words
A sintered exhaust sensor for monitoring the air-fuel ratio of an internal combustion engine comprising: a ceramic substrate; and a mixture of titanium dioxide and a sintering suppressing agent laminated on said substrate, wherein said sintering suppressing agent is selected from the group consisting of Er 2 O 3 and Sm 2 O 3 .
Claim 13
Dependent Claim
55 words
A sintered exhaust sensor for monitoring the air-fuel ratio of an internal combustion engine comprising: a ceramic substrate; and a mixture of titanium dioxide and a sintering suppressing agent laminated on said substrate, wherein said sintering suppressing agent is selected from the group consisting of Er 2 O 3 and Sm 2 O 3 .
Claim 14
Dependent Claim
28 words
An exhaust sensor according to claim 11, wherein the total amount of said agent is in the range from 0.01 to 10 mol % of said titanium dioxide.
Claim 15
Dependent Claim
21 words
An exhaust sensor according to claim 11, wherein said mixture further comprises at least one noble metal of the platinum group.
Claim 16
Dependent Claim
14 words
An exhaust sensor element according to claim 11, wherein said ceramic substrate is alumina.
Claim 17
Dependent Claim
19 words
An exhaust sensor according to claim 11, wherein said mixture consists essentially of titanium dioxide and said sintering agent.
Claim 18
Dependent Claim
21 words
An exhaust sensor according to claim 11, wherein said ceramic substrate has a sintering temperature of about 1300° to 1400° C.
Claim 19
Dependent Claim
28 words
A gas sensor element comprising titanium dioxide and a sintering suppression agent selected from the group consisting of Er 2 O 3 and Sm 2 O 3 .
Claim 20
Dependent Claim
28 words
A gas sensor element comprising titanium dioxide and a sintering suppression agent selected from the group consisting of Er 2 O 3 and Sm 2 O 3 .
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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) | 1991-11-22 | 1992-05-23 | 1992-11-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-11-22 | 1996-05-23 | 1996-11-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-11-22 | 2000-05-23 | 2000-11-22 | $7700.00 | Window Closed / Lapsed |