US3811935A
Expired / Lapsed
US
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Electroconductive recording medium and process of making the same
Assignee: Bull HN Information Systems Italia SpA
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Filing: 1972-10-13
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Granted: 1974-05-21
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Expires: 1992-10-13
Abstract
Abstract A novel electroconductivity additive, potassium formate, is suspended in an aqueous solution and applied to paper during the papermaking process. The resulting impregnated paper is in one embodiment coated with a dielectric during the papermaking process thereby producing a low cost electrographic paper.
Inventors
- 👤 F Gould
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 05:43
CPC Classifications
G; G03; G03G; G03G5/00; G03G5/10; G03G5/101; G03G5/02; G03G5/0202; G03G5/0214; Y; Y10; Y10T; Y10T428/00; Y10T428/26; Y10T428/31504; Y10T428/31971; Y10T428/31993
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
68 words
An electrographic recording medium for receiving a latent charge image by application of a voltage thereacross comprising: a conductive substrate comprising a paper impregnated with a moisture absorbent, electrically conductive agent, said moisture absorbent, electrically conductive agent comprising potassium formate, said potassium formate attracting and holding water so as to thereby increase the electrical conductivity of the paper; and, a thin dielectric coating deposited on said conductive substrate.
Claim 2
Dependent Claim
24 words
The electrographic recording medium of claim 2 wherein the medium percentage by weight of potassium formate is 2 percent of the original paper weight.
Claim 3
Dependent Claim
85 words
An electrographic recording medium for receiving a latent charge image by application of a voltage thereacross comprising: a conductive substrate comprising a paper impregnated with a moisture absorbent, electrically conductive agent, said moisture absorbent, electrically conductive agent comprising potassium formate; and a thin dielectric coating deposited on said conductive substrate, said thin dielectric coating consisting essentially of a metallic salt of an organic fatty acid, wherein said salt has a metal ion selected from the group of metals consisting of zinc, nickel, copper, and cobalt.
Claim 4
Dependent Claim
24 words
The electrographic recording medium of claim 4 wherein the thickness of the dielectric coating is in the range of 90 to 150 micro inches.
Claim 5
Dependent Claim
24 words
The electrographic recording medium of claim 5 wherein the minimum percentage by weight of potassium formate is 2 percent of the original paper weight.
Claim 6
Dependent Claim
16 words
The electrographic recording medium of claim 4 wherein the dielectric coating consists essentially of zinc stearate.
Claim 7
Dependent Claim
23 words
The electrographic medium of claim 7 wherein the thickness of the dielectric coating is in the range of 90 to 150 micro inches.
Claim 8
Dependent Claim
24 words
The electrographic recording medium of claim 8 wherein the minimum percentage by weight of potassium formate is 2 percent of the original paper weight.
Claim 9
Independent Claim
24 words
A method of increasing the electrical conductivity of paper, measured in ohms per square, comprising the step of impregnating said paper with potassium formate.
Claim 10
Dependent Claim
152 words
A process of manufacturing an electrographic medium having a conductive paper substrate and a continuous dielectric surface layer, said process comprising the steps of: a. dissolving a first solute consisting essentially of a metallic salt of an organic fatty acid, in an ammonia and water solvent, so as to create a water-ammonia solution suspending the metallic salt, wherein said salt has a metal ion selected from the group of metals consisting of zinc, nickel, copper, and cobalt; b. dissolving a second solute consisting essentially of a saturated solution of potassium formate in the water-ammonia solution; c. spraying the resulting water-ammonia suspension of potassium formate and the selected metallic salt thereby impregnating the paper with the potassium formate and coating the paper with the metallic salt; and d. drying the resulting coated and impregnated paper so as to form a hardened electrographic medium that is usable over a broad range of relative humidities.
Claim 11
Dependent Claim
70 words
A process of manufacturing an electrically conductive recording medium having a paper substrate comprising the successive steps of: a. dissolving a solute, consisting essentially of potassium formate in water thereby forming an aqueous solution of potassium formate; b. impregnating the paper substrate with the aqueous solution of potassium formate, and c. drying the paper substrate so as to form a hardened paper that is electrically conductive at low relative humidities.
Claim 12
Dependent Claim
38 words
The process of claim 12 in which said paper is a wet, partially dried paper mat and wherein said step of impregnating the paper includes immersing the partially dried paper mat in the aqueous solution of potassium formate.
Claim 13
Dependent Claim
38 words
The process of claim 12 in which said paper is a wet, partially dried paper mat and wherein said step of impregnating the paper includes spraying the partially dried paper mat with the aqueous solution of potassium formate.
Claim 14
Dependent Claim
151 words
A process of manufacturing an electrographic medium having a conductive paper substrate and a continuous discrete dielectric surface layer, said process comprising the steps of: a. dissolving a first solute consisting essentially of a metallic salt of an organic fatty acid, in an ammonia and water solvent, so as to create a water-ammonia solution suspending the metallic salt, wherein said salt has a metal ion selected from the group of metals consisting of zinc, nickel, copper, and cobalt; b. dissolving a second solute consisting essentially of potassium formate in water to thereby create an aqueous solution of potassium formate; c. impregnating the paper substrate with the aqueous solution of potassium formate; d. coating the impregnated paper substrate with the ammonia-water solution of metallic salt; and e. drying the resulting cOated and impregnated paper so as to form a hardened electrographic medium that is usable over a broad range of relative humidities.
Claim 15
Dependent Claim
38 words
The process of claim 15 in which said paper is a wet, partially dried paper mat and wherein said step of impregnating the paper includes immersing the partially dried paper mat in the aqueous solution of potassium formate.
Claim 16
Dependent Claim
38 words
The process of claim 15 in which said paper is a wet, partially dried paper mat and wherein said step of impregnating the paper includes spraying the partially dried paper mat with the aqueous solution of potassium formate.
Claim 17
Dependent Claim
150 words
A process of manufacturing an electrographic medium having a paper substrate and a continuous discrete dielectric surface layer, said process comprising the steps of: a. dissolving a first solute consisting essentially of a metallic salt of an organic fatty acid, in an ammonia and water solvent, so as to create a water-ammonia solution suspending the metallic salt, wherein said salt has a metal ion selected from the group of metals consisting of zinc, nickel, copper, and cobalt; b. dissolving a second solute consisting essentially of potassium formate in water to thereby create an aqueous solution of potassium formate; c. coating the impregnated paper substrate with the ammonia-water solution of metallic salt; d. impregnating the paper substrate with the aqueous solution of potassium formate; and e. drying the resulting coated and impregnated paper so as to form a hardened electrographic medium that is usable over a broad range of relative humidities.
Claim 18
Dependent Claim
38 words
The process of claim 18 in which said paper is a wet, partially dried paper mat and wherein said step of impregnating the paper includes immersing the partially dried paper mat in the aqueous solution of potassium formate.
Claim 19
Dependent Claim
38 words
The process of claim 18 in which said paper is a wet, partially dried paper mat and wherein said step of impregnating the paper includes spraying the partially dried paper mat with the aqueous solution of potassium formate.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-05-20 | 1977-11-19 | 1978-05-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-05-20 | 1981-11-19 | 1982-05-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-05-20 | 1985-11-19 | 1986-05-21 | $7700.00 | Window Closed / Lapsed |