US3076722A - Electrostatic printing - Google Patents
Electrostatic printing Download PDFInfo
- Publication number
- US3076722A US3076722A US809612A US80961259A US3076722A US 3076722 A US3076722 A US 3076722A US 809612 A US809612 A US 809612A US 80961259 A US80961259 A US 80961259A US 3076722 A US3076722 A US 3076722A
- Authority
- US
- United States
- Prior art keywords
- developer
- liquid
- image
- composition
- binder material
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Classifications
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
- G03G9/00—Developers
- G03G9/08—Developers with toner particles
- G03G9/12—Developers with toner particles in liquid developer mixtures
- G03G9/125—Developers with toner particles in liquid developer mixtures characterised by the liquid
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
- G03G9/00—Developers
- G03G9/08—Developers with toner particles
- G03G9/12—Developers with toner particles in liquid developer mixtures
- G03G9/13—Developers with toner particles in liquid developer mixtures characterised by polymer components
- G03G9/131—Developers with toner particles in liquid developer mixtures characterised by polymer components obtained by reactions only involving carbon-to-carbon unsaturated bonds
Definitions
- electrostatic images are produced on the surface of an insulating material. Such images comprise a pattern of electrostatic charges on the surface. Visible images are commonly produced therefrom by cascading across the surface a dry mixture of finely-divided developer particles and substantially larger carrier particles. When the developer particles are triboelectrically charged in the opposite polarity to the electrostatic charges, they deposit in charged areas to produce a visible image in substantial configuration with the pattern of charges. When the developer particles have the same polarity as the electrostatic charges, a visible image is produced in reverse configuration with respect to the pattern of charges.
- the recording element may comprise almost any insulating surface but, preferably, the recording surface is also photoconductive to enable the recording of light images.
- Recording elements comprising photoconductive selenium coated plates are described in US. Patent 2,297,691, issued October 6, 1942, to C. F. Carlson. Recording elements comprising photoconductive coatings on paper are described in the Young and Greig publication,
- liquid developer previously described consists of finely-divided developer particles dispersed in a hydrocarbon liquid. This developer can be flowed over a surface bearing an electrostatic image or the surface can be immersed in a tray of liquid developer. It can also be sprayed or rolled on to the surface.
- appropriate developer particles When appropriate developer particles are dispersed in a properly selected liquid, they acquire an electrophoretic or triboelectric charge enabling them to be attracted to an electrostatic charge pattern of appropriate polarity.
- Deposition of the developer particles on the charge image is an example of the phenomenon known as electrophoresis or cataphoresis.
- a liquid developer process for charge images is described in greater detail by K. A. Metcalf and R. J. Wright in a paper entitled Xerography, published in the Journal of the Oil and Colour Chemists Association, November 1956, volume thereof are generally toxic.
- hydrocarbon liquids are solvents for developer powders which include resins, Waxes, or organic pigments.
- resinous particles When resinous particles are dispersed in a hydrocarbon liquid, they dissolve to some extent so that they become tacky and tend to agglomerate.
- compositions for developing electrostatic images.
- the compositions comprise finely-divided electroscopic developer particles dispersed as a phase in a liquid carrier which also has dissolved therein a binder material for the developer particles.
- the liquid carrier comprises an electrically-insulating liquid which has a viscosity of about 0.4 to 1 centipoise at ordinary room temperatures, which has an evaporation rate substantially greater than that of toluene, and which has a flash point in excess of 200 C.
- an important feature of this invention is the provision of an evaporable carrier liquid which is relatively nontoxic, non-inflammable and has a low viscosity.
- a liquid makes feasible the use of a liquid developer composition in applications such as, for example, office copiers without any need for exhaust equipment to remove noxious vapors. In any such application, however, a well ventilated work area should be provided when development equipment is to be used continuously for extended periods of time.
- a liquid preferably comprises a fluori'nated, chlorinated hydrocarbon which has about equal numbers of fluorine and chlorine atoms.
- a specific example of such a liquid is trichlorotrifluoroethane.
- This liquid is a very selective sol.- vent which will not dissolve most resins and waxes. It has a viscosity of about 0.69 centipoise at room temperature and has an evaporation rate substantially in excess of that of toluene. It is far less toxic than materials such as gasoline or carbon tetrachloride or for that matter almost any organic solvent. It has a flash point in excess of 650 C. Because of its low toxicity and high flash point, it can be employed in ordinary room atmosphere with practically no danger to health and without fire hazard.
- a suitable developer composition finely divided particles of electroscopic developer material, insoluble in the liquid carrier, are dispersed therein in proportions such that up to about 3% by weight of the composition consists of developer particles. Also included in the composition is a binder material for the developer particles, this binder material being dissolved in the liquid 7 carrier in a concentration such that up to about 5% by weight of the composition consists of binder material.
- a specific example of a suitable developer composition is as follows:
- Example I A black pigment is prepared by making two solutions; solution one comprises:
- the composition comprises about 2 /2 by weightv of binder material.
- binder materials may be employed, it only being necessary that the binder material selected be soluble in the selected carrier. liquid.
- binder materials which may be dissolved in trichlorotrifluoroethane include the following:
- pigments which are suitable for use in trichlorotrifluoroethane are the following:
- Pigments may be dispersed in the dimethyl polysiloxane as was the filter cake material exemplified in Example I. When so dispersed, the pigment dispersion is mixed into the carrier liquid in proportions the same as those described for the filter cake dispersion. Alternatively, pigments which are sufficiently finely-divided may be mixed into the carrier liquid directly by any standard means, no ball milling being required.
- the pigment materials are not sufiiciently finely-divided, they may be dispersed in the carrier liquid and ball milled therein to reduce the particle size, provided that ball milling is carried out in a closed system to prevent evaporation of the carrier liquid.
- Another alternative comprises melting the binder material, dispersing the pigment therein, and reducing the hardened melt to a powder of desired particle size. Mixing the powder in the liquid carrier will cause the binder material to dissolve whilev the pigment particles become dispersed therein.
- any of the foregoing developer compositions may be applied to an electrostatic image consisting of a pattern of negative electrostatic charges. Particles suspended in the carrier liquid are attracted by the negative charges and deposited on the pattern of such charges. In such a process, these compositions therefore constitute direct developer compositions.
- compositions When the compositions are employed to develop electrostatic images consisting of patterns of positive electrostatic charges they will be repelled by the charges and will deposit in non-charged areas of the electrostatic image to produce a reverse visible image and hence can be called reverse developer compositions in such processes.
- the carrier liquid in the compositions of the present invention will rapidly evaporate, usually in a few seconds, and will leave hehind on the electrostatic image developer particles which are fixed in place by the binder material.
- developer compositions which, when applied to a pattern of negative elect'rostatic charges, produce a reverse visble image are also provided.
- a developer composition may be prepared by dispersing a pigment in a binder material which has a triboelectrically negative character with respect to the carrier fluid and the negative charges of the electrostatic image.
- a binder material is one which is predominantly comprised of polyvinyl chloride. Preparation of such a composition may be carried out as follows:
- Example II 1 gram of carbon black grams Vinylite VYNV (a copolymer of about 96% vinyl chloride, 4% vinyl acetate) grams of dimethyl polysiloxane (viscosity about 2 centistokes) This mixture is ball milled for about 16 to hours. A solution of binder material in carrier liquid is then prepared in proportions of:
- the resin will comprise at least 90% by weight vinyl chloride.
- the resin comprises 96% by weight vinyl chloride and 4% vinyl acetate, excellent reversal development is achieved.
- Color dispersions may be prepared in a like manner employing most of the pigments discussed heretofore.
- those which are soluble in the carrier liquid may also be employed when they are first dispersed in a polyvinyl chloride resin which is insoluble in the carrier liquid.
- These pigments need not necessarily be ball milled in dimethyl polysiloxane but may be, instead, dispersed in a hot melt of the polyvinyl chloride resin and then reduced to powder form of the desired fineness to produce insoluble developer particles.
- Example II The developer compositions of Example II have been described as being reversal type compositions for the development of negative patterns of electrostatic charges. They may also be employed to develop patterns of positive electrostatic charges in which case they deposit on charged areas to produce a direct visible image.
- the methods call for applying a developer composition to an electrostatic image by such means as, for example, flowing across the image, spraying, application with a roller, or by immersing the image in a tray containing the liquid composition.
- a developer composition to an electrostatic image by such means as, for example, flowing across the image, spraying, application with a roller, or by immersing the image in a tray containing the liquid composition.
- a color image may be overprinted with a second color image and again overprinted with a third (or more) to provide a composite image in as many colors as desired and, at the same time, to provide for color mixing.
- saturated solutions of binder material are employed as suggested herein, a visible image is produced and the image surface will have a high gloss.
- the images produced by the methods of this invention are durable and can withstand repeated handlings without smearing. When produced on a flexible surface the visible image will flex with that surface rather than peel or chip therefrom.
- a composition of matter consisting essentially of a carrier liquid consisting essentially of trichlorotrifluoroethane, electroscopic organic pigment particles dispersed as a phase in said liquid, and a separate binder material for said pigment consisting essentially of a polyisobutylmethacrylate dissolved in said liquid, said binder material comprising about 0.1 to 5.0% by weight of said composition.
- composition of claim 1 wherein the concentration of said pigment particles in said composition is not in excess of about 3 by weight.
- composition of claim 3 wherein the concentration of said pigment particles in said composition is about 0.25% by weight and the concentration of said binder material in said composition is about 0.70% by weight.
- a composition of matter consisting essentially of a carrier liquid consisting essentially of trichlorotrifluoroethane, finely-divided electroscopic developer particles dispersed as a phase in said liquid, said developer particles consisting essentially of about 5 to 10 parts by weight of resin and about one part by weight of color pigment, said resin consisting essentially of a copolymer of about 96% by weight of vinyl chloride and 4% by weight of vinyl acetate and a separate binder material for said developer particles dissolved in said liquid, said binder material, comprising about 0.1 to 5.0% by weight of said composition, and consisting essentially of a polyisobutylmethacrylate.
- composition of claim 4 wherein the concentration of said developer particles in said composition is not in excess of about 3% by weight.
- a method of developing an electrostatic image on an insulating surface said image comprising a pattern of negative electrostatic charges
- the improvement comprising applying to said surface a developer composition consisting essentially of pigment electroscopic developer particles dispersed as a phase in trichlorotrifluoroethane and a polyisobutylmethacrylate binder material dissolved in said trichlorotrifluoroethane, said binder material comprising about -0.1 to 5.0% by weight of said composition, depositing said developer particles on said pattern of negative electrostatic charges, and binding said developer particles to said surface with said polyisobutylmethacrylate by evaporating said trichlorotrifluoroethane from said surface.
- a developer composition consisting essentially of pigmented electroscopic developer particles the major proportion of which is vinyl chloride dispersed as a phase in trichlorotrifluoroethane and a polyisobutylmethacrylate binder material dissolved in said trichlorotrifluoroethane, said binder material comprising about 0.1 to 5.0% by weight of said composition, de 2,735,784 .G-reig et al. Feb. 21, 1956 positing said. developer particles in areas other than said 2,773,855 Hochberg et a1 Dec.
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- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Developing Agents For Electrophotography (AREA)
- Liquid Developers In Electrophotography (AREA)
Priority Applications (5)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
NL251005D NL251005A (hu) | 1959-04-29 | ||
US809612A US3076722A (en) | 1959-04-29 | 1959-04-29 | Electrostatic printing |
GB13277/60A GB949176A (en) | 1959-04-29 | 1960-04-13 | An electrostatic image developing material |
FR825577A FR1255270A (fr) | 1959-04-29 | 1960-04-28 | Impression électrostatique |
CH491160A CH399174A (de) | 1959-04-29 | 1960-04-29 | Entwickler für elektrostatische Druckverfahren und Verwendung desselben |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US809612A US3076722A (en) | 1959-04-29 | 1959-04-29 | Electrostatic printing |
Publications (1)
Publication Number | Publication Date |
---|---|
US3076722A true US3076722A (en) | 1963-02-05 |
Family
ID=25201782
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US809612A Expired - Lifetime US3076722A (en) | 1959-04-29 | 1959-04-29 | Electrostatic printing |
Country Status (4)
Country | Link |
---|---|
US (1) | US3076722A (hu) |
CH (1) | CH399174A (hu) |
GB (1) | GB949176A (hu) |
NL (1) | NL251005A (hu) |
Cited By (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3220830A (en) * | 1961-10-02 | 1965-11-30 | Kenffel & Esser Company | Method of developing a negative electrostatic latent image |
US3334047A (en) * | 1962-05-16 | 1967-08-01 | Australia Res Lab | Liquid dispersible toner for electrophotography |
US3337340A (en) * | 1961-12-28 | 1967-08-22 | Australia Res Lab | Method for the reproduction of color |
US3365324A (en) * | 1963-03-18 | 1968-01-23 | Bernice B Blake | Solution development of xerographic latent images |
US3391014A (en) * | 1964-04-27 | 1968-07-02 | Harris Intertype Corp | Liquid development of electrostatic images |
US3419411A (en) * | 1963-09-06 | 1968-12-31 | Australia Res Lab | Method for the transfer of developed electrostatic images using a lattice forming substance |
US3444083A (en) * | 1966-09-19 | 1969-05-13 | Australia Res Lab | Electrophotographic toners |
US3472676A (en) * | 1965-11-18 | 1969-10-14 | Gevaert Photo Prod Nv | Process for developing electrostatic charge patterns |
US3486922A (en) * | 1967-05-29 | 1969-12-30 | Agfa Gevaert Nv | Development of electrostatic patterns with aqueous conductive developing liquid |
US3669886A (en) * | 1968-09-11 | 1972-06-13 | Hunt Chem Corp Philip A | Liquid developer for electrostatography |
US3971659A (en) * | 1968-12-28 | 1976-07-27 | Xerox Corporation | Color electrophotographic process using photoconductive particles in liquid developer |
Citations (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2297691A (en) * | 1939-04-04 | 1942-10-06 | Chester F Carlson | Electrophotography |
US2381753A (en) * | 1941-01-03 | 1945-08-07 | Gen Printing Ink Corp | Printing ink |
US2731436A (en) * | 1950-02-25 | 1956-01-17 | Engine Parts Mfg Company | Metallic paint |
US2735784A (en) * | 1953-07-30 | 1956-02-21 | Process of electrostatic printing | |
US2773855A (en) * | 1952-10-07 | 1956-12-11 | Allied Chem & Dye Corp | Compositions for decorative purposes |
US2892794A (en) * | 1955-01-03 | 1959-06-30 | Haloid Xerox Inc | Electrostatic developer and toner |
US2898279A (en) * | 1956-06-14 | 1959-08-04 | Commw Of Australia | Coating surfaces by employing an electrostatic field |
US2899335A (en) * | 1956-10-31 | 1959-08-11 | Process for developing electrostatic | |
US2907674A (en) * | 1955-12-29 | 1959-10-06 | Commw Of Australia | Process for developing electrostatic image with liquid developer |
US2940934A (en) * | 1953-06-22 | 1960-06-14 | Haloid Xerox Inc | Electrostatic developer composition and method therefor |
US3010842A (en) * | 1955-08-29 | 1961-11-28 | Xerox Corp | Development of electrostatic images |
US3038799A (en) * | 1958-01-13 | 1962-06-12 | Commw Of Australia | Method of reversing the image in xerography |
-
0
- NL NL251005D patent/NL251005A/xx unknown
-
1959
- 1959-04-29 US US809612A patent/US3076722A/en not_active Expired - Lifetime
-
1960
- 1960-04-13 GB GB13277/60A patent/GB949176A/en not_active Expired
- 1960-04-29 CH CH491160A patent/CH399174A/de unknown
Patent Citations (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2297691A (en) * | 1939-04-04 | 1942-10-06 | Chester F Carlson | Electrophotography |
US2381753A (en) * | 1941-01-03 | 1945-08-07 | Gen Printing Ink Corp | Printing ink |
US2731436A (en) * | 1950-02-25 | 1956-01-17 | Engine Parts Mfg Company | Metallic paint |
US2773855A (en) * | 1952-10-07 | 1956-12-11 | Allied Chem & Dye Corp | Compositions for decorative purposes |
US2940934A (en) * | 1953-06-22 | 1960-06-14 | Haloid Xerox Inc | Electrostatic developer composition and method therefor |
US2735784A (en) * | 1953-07-30 | 1956-02-21 | Process of electrostatic printing | |
US2892794A (en) * | 1955-01-03 | 1959-06-30 | Haloid Xerox Inc | Electrostatic developer and toner |
US3010842A (en) * | 1955-08-29 | 1961-11-28 | Xerox Corp | Development of electrostatic images |
US2907674A (en) * | 1955-12-29 | 1959-10-06 | Commw Of Australia | Process for developing electrostatic image with liquid developer |
US2898279A (en) * | 1956-06-14 | 1959-08-04 | Commw Of Australia | Coating surfaces by employing an electrostatic field |
US2899335A (en) * | 1956-10-31 | 1959-08-11 | Process for developing electrostatic | |
US3038799A (en) * | 1958-01-13 | 1962-06-12 | Commw Of Australia | Method of reversing the image in xerography |
Cited By (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3220830A (en) * | 1961-10-02 | 1965-11-30 | Kenffel & Esser Company | Method of developing a negative electrostatic latent image |
US3337340A (en) * | 1961-12-28 | 1967-08-22 | Australia Res Lab | Method for the reproduction of color |
US3334047A (en) * | 1962-05-16 | 1967-08-01 | Australia Res Lab | Liquid dispersible toner for electrophotography |
US3365324A (en) * | 1963-03-18 | 1968-01-23 | Bernice B Blake | Solution development of xerographic latent images |
US3419411A (en) * | 1963-09-06 | 1968-12-31 | Australia Res Lab | Method for the transfer of developed electrostatic images using a lattice forming substance |
US3391014A (en) * | 1964-04-27 | 1968-07-02 | Harris Intertype Corp | Liquid development of electrostatic images |
US3472676A (en) * | 1965-11-18 | 1969-10-14 | Gevaert Photo Prod Nv | Process for developing electrostatic charge patterns |
US3444083A (en) * | 1966-09-19 | 1969-05-13 | Australia Res Lab | Electrophotographic toners |
US3486922A (en) * | 1967-05-29 | 1969-12-30 | Agfa Gevaert Nv | Development of electrostatic patterns with aqueous conductive developing liquid |
US3669886A (en) * | 1968-09-11 | 1972-06-13 | Hunt Chem Corp Philip A | Liquid developer for electrostatography |
US3971659A (en) * | 1968-12-28 | 1976-07-27 | Xerox Corporation | Color electrophotographic process using photoconductive particles in liquid developer |
Also Published As
Publication number | Publication date |
---|---|
GB949176A (en) | 1964-02-12 |
CH399174A (de) | 1966-03-31 |
NL251005A (hu) |
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