US4000089A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Element for detecting carbon monoxide
Assignee: Nohmi Bosai Ltd
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Filing: 1974-05-23
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Granted: 1976-12-28
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Expires: 1994-05-23
Abstract
Abstract This invention relates to an element which can detect selectively carbon monoxide from other reducing gases contained in air. The element has a sensitive response to carbon monoxide at a comparatively low temperature and not to other reducing gases. The element has a composition comprising stannic oxide as a base material, platinum black as a catalyst and, if necessary, clay, ferric oxide or glassy substances as a sintering agent. A starting substance for stannic oxide may be stannic oxide itself or any stannic salt which is changed into stannic oxide by baking. A starting substance for platinum black may be platinum black itself or any platinum salt which is changed into platinum black by baking. The above starting substances are thoroughly mixed and baked to form a detecting element. The element may be used as a lump by itself, but it is convenient that it is used as a film of the element baked on a heat-resisting insulating material such as an alumina ceramics, quartz glass or boracic silica glass.
Inventors
- 👤 Tamotsu Senda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 10:29
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/02; G01N27/04; G01N27/12; Y; Y10; Y10T; Y10T436/00; Y10T436/20; Y10T436/204998; Y10T436/205831
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
52 words
A composition for the detection of carbon monoxide comprising stannic oxide as a base metal and platinum comprising platinum black as an agent for imparting to said composition the ability to selectively detect the presence of carbon monoxide, said platinum constituting a minimum of about 0.5 percent by weight of said composition.
Claim 2
Dependent Claim
52 words
A composition for the detection of carbon monoxide comprising stannic oxide as a base metal and platinum comprising platinum black as an agent for imparting to said composition the ability to selectively detect the presence of carbon monoxide, said platinum constituting a minimum of about 0.5 percent by weight of said composition.
Claim 3
Dependent Claim
83 words
A composition for the detection of carbon monoxide comprising stannic oxide or stannic salts capable of changing to stannic oxide upon baking, as a base material; and platinum black or platinum salts that change to platinum black upon baking as an agent for imparting to said composition the ability to selectively detect the presence of carbon monoxide, said platinum black or said platinum salts constituting a minimum of about 0.5 percent by weight of said composition as calculated in terms of metallic platinum.
Claim 4
Dependent Claim
83 words
A composition for the detection of carbon monoxide comprising stannic oxide or stannic salts capable of changing to stannic oxide upon baking, as a base material; and platinum black or platinum salts that change to platinum black upon baking as an agent for imparting to said composition the ability to selectively detect the presence of carbon monoxide, said platinum black or said platinum salts constituting a minimum of about 0.5 percent by weight of said composition as calculated in terms of metallic platinum.
Claim 5
Dependent Claim
17 words
The composition of claim 2, comprising a maximum of about 10 percent by weight of said platinum.
Claim 6
Dependent Claim
24 words
The composition of claim 2, comprising at least one member of the group of sintering agents consisting of clay, ferric oxide and glassy substances.
Claim 7
Dependent Claim
51 words
A composition for the detection of carbon monoxide, comprising stannic oxide as a base material; and platinum black as an agent for imparting to said compostion the ability to selectively detect the presence of carbon monoxide, said platinum black constituting between about 0.5 and 10 percent by weight of said composition.
Claim 8
Dependent Claim
51 words
A composition for the detection of carbon monoxide, comprising stannic oxide as a base material; and platinum black as an agent for imparting to said compostion the ability to selectively detect the presence of carbon monoxide, said platinum black constituting between about 0.5 and 10 percent by weight of said composition.
Claim 9
Independent Claim
125 words
A method of making compositions for the detection of carbon monoxide, comprising forming a mixture which includes a first substance selected from the group consisting of stannic oxide and stannic salts capable of changing to stannic oxide upon baking, and a second substance selected from the group consisting of platinum black and platinum salts that change to platinum black upon baking, said second substance constituting a minimum of about 0.5 percent by weight of said mixture as calculated in terms of metallic platinum; and heating said mixture so as to obtain a composition which includes stannic oxide as a base material and platinum black or platinum salts as an agent for imparting to said composition the ability to selectively detect the presence of carbon monoxide.
Claim 10
Independent Claim
125 words
A method of making compositions for the detection of carbon monoxide, comprising forming a mixture which includes a first substance selected from the group consisting of stannic oxide and stannic salts capable of changing to stannic oxide upon baking, and a second substance selected from the group consisting of platinum black and platinum salts that change to platinum black upon baking, said second substance constituting a minimum of about 0.5 percent by weight of said mixture as calculated in terms of metallic platinum; and heating said mixture so as to obtain a composition which includes stannic oxide as a base material and platinum black or platinum salts as an agent for imparting to said composition the ability to selectively detect the presence of carbon monoxide.
Claim 11
Dependent Claim
24 words
The method of claim 6 wherein said heating is carried out in an oxidizing atmosphere when baking the composition to form a detector element.
Claim 12
Dependent Claim
26 words
The method of claim 6, wherein said mixture is heated to temperatures between 400° and 900° C, when baking the composition to form a detector element.
Claim 13
Dependent Claim
27 words
The method of claim 6, wherein said mixture is heated for a period between 15 and 60 minutes, when baking the composition to form a detector element.
Claim 14
Dependent Claim
39 words
The method of claim 6, wherein said mixture is heated to temperatures between 400° and 900° C for a period of about 15 to 60 minutes in an oxidizing atmosphere, when baking the composition to form a detector element.
Claim 15
Dependent Claim
12 words
The method of claim 6, wherein said heating comprises sintering said mixture.
Claim 16
Dependent Claim
28 words
The method of claim 6, wherein said second substance constitutes a maximum of about 10 percent by weight of said mixture as calculated in terms of metallic platinum.
Claim 17
Dependent Claim
14 words
The method of claim 6, wherein the platinum in said composition comprises platinum black.
Claim 18
Dependent Claim
12 words
The method of claim 6, wherein said forming comprises kneading said mixture.
Claim 19
Dependent Claim
16 words
The method of claim 6, wherein said forming comprises incorporating a sintering agent in said mixture.
Claim 20
Dependent Claim
23 words
The method of claim 15, wherein said sintering agent comprises a substance from the group consisting of clay, ferric oxide and glassy substances.
Claim 21
Independent Claim
153 words
A method of making compositions for the detection of carbon monoxide, comprising forming a mixture which includes a first substance selected from the group consisting of stannic oxide and stannic salts capable of changing to stannic oxide upon baking, and a second substance selected from the group consisting of platinum black and platinum salts that change to platinum black upon baking, said second substance constituting between about 0.5 and about 10 percent by weight of said mixture as calculated in terms of metallic platinum; and heating said mixture to temperature between about 400° and 900° C for a period of about 15 to 60 minutes in an oxidizing atmosphere, when baking the composition to form a detector element, so as to obtain a composition which includes stannic oxide as a base material and platinum black as an agent for imparting to said composition the ability to selectively detect the pressence of carbon monoxide.
Claim 22
Independent Claim
153 words
A method of making compositions for the detection of carbon monoxide, comprising forming a mixture which includes a first substance selected from the group consisting of stannic oxide and stannic salts capable of changing to stannic oxide upon baking, and a second substance selected from the group consisting of platinum black and platinum salts that change to platinum black upon baking, said second substance constituting between about 0.5 and about 10 percent by weight of said mixture as calculated in terms of metallic platinum; and heating said mixture to temperature between about 400° and 900° C for a period of about 15 to 60 minutes in an oxidizing atmosphere, when baking the composition to form a detector element, so as to obtain a composition which includes stannic oxide as a base material and platinum black as an agent for imparting to said composition the ability to selectively detect the pressence of carbon monoxide.
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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) | 1979-12-28 | 1980-06-28 | 1980-12-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-12-28 | 1984-06-28 | 1984-12-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-12-28 | 1988-06-28 | 1988-12-28 | $7700.00 | Window Closed / Lapsed |