US3933489A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrostatic reproduction process employing novel transfer paper
Assignee: Preco Corp
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Filing: 1974-02-21
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Granted: 1976-01-20
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Expires: 1994-02-21
Abstract
Abstract Electrostatic reproduction processes utilizing papers which have a surface resistivity of not more than 0.9-3 × 10 11 IPC ohmn/square at a relative humidity of 25 percent and a surface resistivity of not more than 25-60 × 10 11 IPC ohms/square at a relative humidity of 10 percent.
Inventors
- 👤 Wally Z. Walters
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 16:29
CPC Classifications
G; G03; G03G; G03G7/00; G03G7/006; G03G7/0066
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
300 words
In the method of producing a visual image on a copy member comprising the steps of forming a latent electrostatic image on an electrostatically chargeable, photoconductive member by producing a patterned distribution of electrical charges thereon; applying to said photoconductive member a finely divided, pigmented toner which will adhere to those areas of the member where a charge is present; transferring said toner from said photoconductive member to an image receiving surface of an uncharged copy member made of paper; and heating the copy member to fuse the toner thereto in a high temperature environment in which the relative humidity ranges down to 10 percent or lower, the improvement wherein the toner is transferred to a copy member which is resistant to the build-up of static charges on its image receiving surface in the low humidity, high temperature environment in which the copy member is located while the toner is fused thereto and which comprises means for making said image receiving surface counteractive to the retention of static charges which are transferred with said toner particles to said image receiving surface and a web of cellulosic material, said means being an electrical conductivity imparting additive distributed on or in the web in an amount sufficient to reduce the surface resistivity of the image receiving surface to from not more than 3 × 10 11 ohms/square at a relative humidity of 25 percent up to not more than 60 × 10 11 ohms/square at a relative humidity of 10 percent to thereby facilitate the dissipation of static charges therefrom in said low humidity, high temperature environment and thereby keep said charges from remaining on said image receiving surface and creating a tendency for the copy member to stick to another charged copy member or to parts of the copy making apparatus.
Claim 2
Dependent Claim
300 words
In the method of producing a visual image on a copy member comprising the steps of forming a latent electrostatic image on an electrostatically chargeable, photoconductive member by producing a patterned distribution of electrical charges thereon; applying to said photoconductive member a finely divided, pigmented toner which will adhere to those areas of the member where a charge is present; transferring said toner from said photoconductive member to an image receiving surface of an uncharged copy member made of paper; and heating the copy member to fuse the toner thereto in a high temperature environment in which the relative humidity ranges down to 10 percent or lower, the improvement wherein the toner is transferred to a copy member which is resistant to the build-up of static charges on its image receiving surface in the low humidity, high temperature environment in which the copy member is located while the toner is fused thereto and which comprises means for making said image receiving surface counteractive to the retention of static charges which are transferred with said toner particles to said image receiving surface and a web of cellulosic material, said means being an electrical conductivity imparting additive distributed on or in the web in an amount sufficient to reduce the surface resistivity of the image receiving surface to from not more than 3 × 10 11 ohms/square at a relative humidity of 25 percent up to not more than 60 × 10 11 ohms/square at a relative humidity of 10 percent to thereby facilitate the dissipation of static charges therefrom in said low humidity, high temperature environment and thereby keep said charges from remaining on said image receiving surface and creating a tendency for the copy member to stick to another charged copy member or to parts of the copy making apparatus.
Claim 3
Dependent Claim
91 words
The method of claim 1, wherein the conductivity imparting additive distributed in the paper on which the visual image is formed is an ionizable salt and wherein said cellulosic web has distributed in the surface portions thereof an amount of said ionizable salt which is sufficient to produce a surface resistivity of not more than about 0.9 × 10 11 IPC ohms/square at a relative humidity of 25 percent and a surface resistivity of not more than about 25 × 10 11 IPC ohms/square at a relative humidity of 10 percent.
Claim 4
Dependent Claim
38 words
The method of claim 1, wherein said conductivity imparting additive comprises at least about 0.012 grams per standard sheet of a readily ionizable salt dispersed in the copy member and extending into the image receiving surface portions thereof.
Claim 5
Dependent Claim
45 words
The method of claim 3, wherein the ionizable salt dispersed in the paper on which the visual image is formed is free of coloring effect on the cellulosic web, soluble in water, an electrolyte, non-volatile, and discoloration resistant at temperatures of up to about 250°C.
Claim 6
Dependent Claim
12 words
The method of claim 4, wherein the ionizable salt is sodium chloride.
Claim 7
Dependent Claim
90 words
The method of claim 3, wherein the paper on which the visual image is formed also includes a humectant dispersed in the image receiving surface portions of the cellulosic web constituting said paper to increase the effectiveness of the ionizable salt in dissipating static charges at low relative humidities, said humectant being soluble or miscible in water and being free of coloring effect on said cellulosic web, and said humectant having a sufficiently high boiling point to withstand temperatures of up to about 250°C. without significant evaporation from the web.
Claim 8
Dependent Claim
29 words
The method of claim 6, wherein the humectant is glycerin and is present in a ratio of at least about 11/2 pounds of glycerin per ton of cellulosic web.
Claim 9
Dependent Claim
31 words
The method of claim 3, wherein the paper on which the visual image is formed also includes a binder dispersed in the surface portions of the cellulosic web constituting said paper.
Claim 10
Dependent Claim
14 words
The method of claim 8, wherein the binder is an enzyme converted potato starch.
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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) | 1979-01-19 | 1979-07-21 | 1980-01-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-01-19 | 1983-07-21 | 1984-01-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-01-19 | 1987-07-21 | 1988-01-20 | $7700.00 | Window Closed / Lapsed |