US5236737A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electroconductive composition and process of preparation
Assignee: Milliken and Co
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Filing: 1991-06-06
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Granted: 1993-08-17
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Expires: 2011-06-06
Abstract
Abstract An electroconductive composition comprising a two-dimensional network of antimony-containing tin oxide crystallites in association with amorphous silica, the composition according to one aspect of the invention comprising a powder of submicron to tens of micron size particles capable of forming a conductive network within a carrier matrix, such as a thin film matrix, and a process for preparing the composition.
Inventors
- 👤 Howard R. Linton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 13:06
CPC Classifications
H; H01; H01B; H01B1/00; H01B1/06; H01B1/08
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
92 words
A process for preparing an electroconductive composition comprising amorphous silica or an amorphous silica-containing material in association with a two-dimensional conducting network of antimony-containing tin oxide crystallites which comprises the steps of: (a) providing a substrate of amorphous hydroxylated silica or of a material which contains amorphous hydroxylated silica; (b) applying a coating consisting essentially of hydrous oxides of antimony and tin to the substrate surface; and (c) calcining the coated substrate at a temperature in the range of from at least 600° C. up to 900°C. whereby the crystallites are formed.
Claim 2
Dependent Claim
92 words
A process for preparing an electroconductive composition comprising amorphous silica or an amorphous silica-containing material in association with a two-dimensional conducting network of antimony-containing tin oxide crystallites which comprises the steps of: (a) providing a substrate of amorphous hydroxylated silica or of a material which contains amorphous hydroxylated silica; (b) applying a coating consisting essentially of hydrous oxides of antimony and tin to the substrate surface; and (c) calcining the coated substrate at a temperature in the range of from at least 600° C. up to 900°C. whereby the crystallites are formed.
Claim 3
Dependent Claim
21 words
The process of claim 1 in which the substrate of amorphous hydroxylated silica is provided by precipitating the silica from solution.
Claim 4
Dependent Claim
32 words
The process of claim 1 in which the coated substrate is calcined at a temperature in the range of from at least 600° C. up to 900° C. in an oxygen-containing atmosphere.
Claim 5
Dependent Claim
35 words
The process of claim 1 in which the amorphous hydroxylated silica or amorphous silica-containing substrate is provided by coating a finely divided inert core material with active silica or a material which contains active silica.
Claim 6
Dependent Claim
21 words
The process of claim 4 in which the core material is a carbonate selected from BaCO 3 and CaCO 3 .
Claim 7
Dependent Claim
22 words
The process of claim 4 in which the core material is selected from BaSO 4 , CaSO 4 and TiO 2 .
Claim 8
Dependent Claim
20 words
The process as in any one of claims for 6 which includes the additional step of removing the core material.
Claim 9
Dependent Claim
86 words
A process as in any one of claims 4-7 in which the core material is coated with active silica by: (a) suspending the core material in water and adding a source of active silica while maintaining the pH of the suspension at a value in the range of 8 to 11; and (b) neutralizing alkali contained in the source of silica by adding a dilute mineral acid to the suspension over a predetermined period of time based on the amount of silica present in the suspension.
Claim 10
Dependent Claim
23 words
The process of claim 8 in which the mineral acid is selected from H 2 SO 4 , HCl, and HNO 3 .
Claim 11
Dependent Claim
34 words
The process of claim 8, in which the core material is removed by suspending the silica coated particles in water and adding a solvent in which the core material is soluble to the suspension.
Claim 12
Dependent Claim
100 words
A process as in any one of claims 1-7 in which the coating layer of hydrous oxides of antimony and tin is applied to the silica substrate by: (a) preparing separate aqueous solutions of hydrolyzable tetravalent Sn and trivalent Sb salts; (b) combining the Sn and Sb salt solutions; and (c) adding the combined solution to a slurry of the silica substrate over a predetermined period of time while maintaining the pH of the slurry in the range of 1.5 to 3.5 and the temperature of the slurry in the range of from 25° to 100° C. under continuous agitation.
Claim 13
Dependent Claim
46 words
The process of claim 11 in which the slat solutions are added to a slurry which contains a concentration of up to 3 molar of a grain refiner or mixture of grain refiners selected from alkali metals, alkaline earth metals, transition metals, and rare earth elements.
Claim 14
Dependent Claim
19 words
The process of claim 12 in which the grain refiner is selected from Ca, Ba, Sr, Zn, and Mg.
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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) | 1996-08-16 | 1997-02-15 | 1997-08-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-08-16 | 2001-02-15 | 2001-08-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-08-16 | 2005-02-15 | 2005-08-17 | $7700.00 | Window Closed / Lapsed |