US3632484A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrolytic facsimile-recording process
Assignee: Individual
•
Filing: 1970-01-27
•
Granted: 1972-01-04
•
Expires: 1990-01-27
Abstract
Abstract Process of electrolytic facsimile-recording employing a silver or silver-alloy anode and a recording medium comprising paper impregnated with an aqueous solution of a formaldehyde reducing agent, wherein the impregnant includes a substance which will render soluble silver salts normally present during electrolytic facsimile recording in an insoluble form. The solubilizing substance may be an alkali metal salt of thiosulfate, thiocyanate or cyanide or an excess quantity of sodium formaldehyde sulfoxylate.
Inventors
- 👤 Robert Doughty Richards
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 18:19
CPC Classifications
B; B41; B41M; B41M5/00; B41M5/20; B41M5/205
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
25 words
The improvement of claim 1 wherein said substance is selected from the group consisting of alkali metal thiosulfates, thiocyanates and cyanides and mixtures of same.
Claim 2
Dependent Claim
20 words
The improvement of claim 2 wherein said substance is present in from about 2-10 percent by weight of the impregnant.
Claim 3
Dependent Claim
19 words
The improvement of claim 2 wherein said substance is selected from the group consisting of sodium and potassium thiosulfates.
Claim 4
Dependent Claim
19 words
The improvement of claim 2 wherein said substance is selected from the group consisting of sodium and potassium thiocyanates.
Claim 5
Dependent Claim
23 words
The improvement of claim 1 wherein said substance comprises sodium formaldehyde sulfoxylate in concentrations from about 13-25 percent by weight of the impregnant.
Claim 6
Dependent Claim
34 words
The improvement of claim 6 wherein said sodium formaldehyde sulfoxylate has been purified by recrystallization from an aqueous solution of an alkaline buffer to at least substantially eliminate sulfite, sulfate and sulfide salts therefrom.
Claim 7
Dependent Claim
68 words
A composition for an electrolytic recording medium for use in a recording process in which silver is electrolytically oxidized and subsequently deposited as a black or dark-colored precipitate, which comprises an absorbent paper impregnated with an aqueous solution of a substance which will render soluble silver salts normally present during electrolytic recording in an insoluble form, said substance being incorporated in sufficient quantity to solubilize said silver salts.
Claim 8
Dependent Claim
26 words
The composition of claim 8 wherein said substance is selected from the group consisting of alkali metal thiosulfates, thiocyanates and cyanides, and mixtures of the same.
Claim 9
Dependent Claim
20 words
The composition of claim 9 wherein said substance is present in from aboUt 2-10 percent by weight of the impregnant.
Claim 10
Dependent Claim
19 words
The composition of claim 8 wherein said substance is selected from the group consisting of sodium and potassium thiosulfates.
Claim 11
Dependent Claim
19 words
The composition of claim 8 wherein said substance is selected from the group consisting of sodium and potassium thiocyanates.
Claim 12
Dependent Claim
23 words
The composition of claim 8 wherein said substance is sodium formaldehyde sulfoxylate in concentrations between about 13-25 percent by weight of the impregnant.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-01-03 | 1975-07-05 | 1976-01-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-03 | 1979-07-05 | 1980-01-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-03 | 1983-07-05 | 1984-01-04 | $7700.00 | Window Closed / Lapsed |