US4478812A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Preparation of materials
Assignee: United Kingdom Atomic Energy Authority
•
Filing: 1983-08-12
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Granted: 1984-10-23
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Expires: 2003-08-12
Abstract
Abstract The present invention relates to the preparation of materials and more particularly to the preparation of tin oxide materials. Thus, the present invention provides a process for the preparation of a tin oxide material by a gel precipitation process which includes contacting together a metal stannate, an organic gelling agent comprising a salt of a polycarboxylic acid and an acidic precipitating agent to form a gel precipitate. The gel precipitate may be treated further to provide the tin oxide material. The tin oxide material may be tin oxide as such, or a mixed oxide material containing tin oxide and an oxide of another element.
Inventors
- 👤 Edward S. Lane
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 04:00
CPC Classifications
C; C01; C01G; C01G19/00; C01G19/02; C01B; C01B13/00; C01B13/14; C01B13/36
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
52 words
A process for the preparation of a precursor for a tin oxide material by a gel precipitation process which includes contacting together a metal stannate, an organic gelling agent comprising a salt of a polycarboxylic acid and an acidic precipitating agent to form a gel precipitate precursor for a tin oxide material.
Claim 2
Dependent Claim
52 words
A process for the preparation of a precursor for a tin oxide material by a gel precipitation process which includes contacting together a metal stannate, an organic gelling agent comprising a salt of a polycarboxylic acid and an acidic precipitating agent to form a gel precipitate precursor for a tin oxide material.
Claim 3
Dependent Claim
16 words
A process as claimed in claim 1 wherein the metal stannate is an alkali metal stannate.
Claim 4
Dependent Claim
23 words
A process as claimed in claim 2 wherein the metal stannate is selected from the group consisting of sodium stannate and potassium stannate.
Claim 5
Dependent Claim
22 words
A process as claimed in claim 1 wherein the salt of a polycarboxylic acid is the salt of a polymeric carboxylic acid.
Claim 6
Dependent Claim
32 words
A process as claimed in claim 4 wherein the salt of the polymeric carboxylic acid is a salt of: polyacrylic acid, polymethacrylic acid or a co-polymer of vinyl compound containing carboxy groups.
Claim 7
Dependent Claim
23 words
A process as claimed in claim 1 wherein the salt of a polycarboxylic acid is a salt of a naturally occurring polycarboxylic acid.
Claim 8
Dependent Claim
22 words
A process as claimed in claim 6 wherein the salt of a naturally occurring polycarboxylic acid in a salt of alginic acid.
Claim 9
Dependent Claim
22 words
A process as claimed in claim 1 wherein the acidic precipitating agent is an aqueous mineral acid or an aqueous organic acid.
Claim 10
Dependent Claim
26 words
A process as claimed in claim 8 wherein the acidic precipitating agent is selected from the group consisting of aqueous nitric acid and aqueous acetic acid.
Claim 11
Dependent Claim
29 words
A process as claimed in claim 1 wherein a metal stannate and a salt of a polycarboxylic acid are mixed together and subsequently contacted with an acidic precipitating agent.
Claim 12
Dependent Claim
47 words
A process as claimed in claim 10 wherein spherical particles of gel precipitate precursor are formed by forming a mixture of metal stannate and organic gelling agent into droplets and contacting the droplets with acidic precipitating agent to gel the droplets to give particles of gel precipitate.
Claim 13
Dependent Claim
20 words
A process as claimed in claim 1 wherein the gel precipitate precursor is heated to give a tin oxide material.
Claim 14
Dependent Claim
42 words
A process as claimed in claim 12 wherein the composition of the gel precipitate precursor is such that after heating the tin oxide material comprises mixed oxides of tin and molybdenum oxide, or tin and tungsten oxides, or tin oxide and silica.
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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) | 1987-10-23 | 1988-04-23 | 1988-10-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-10-23 | 1992-04-23 | 1992-10-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-10-23 | 1996-04-23 | 1996-10-23 | $7700.00 | Window Closed / Lapsed |