US2891911A - Developer for electrostatic printing - Google Patents

Developer for electrostatic printing Download PDF

Info

Publication number
US2891911A
US2891911A US513566A US51356655A US2891911A US 2891911 A US2891911 A US 2891911A US 513566 A US513566 A US 513566A US 51356655 A US51356655 A US 51356655A US 2891911 A US2891911 A US 2891911A
Authority
US
United States
Prior art keywords
image
liquid
opaque
composition
polyethylene
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
Application number
US513566A
Inventor
Edward F Mayer
Virgil E Straughan
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
General Dynamics Corp
Original Assignee
General Dynamics Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by General Dynamics Corp filed Critical General Dynamics Corp
Priority to US513566A priority Critical patent/US2891911A/en
Application granted granted Critical
Publication of US2891911A publication Critical patent/US2891911A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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
    • G03G9/135—Developers with toner particles in liquid developer mixtures characterised by stabiliser or charge-controlling agents
    • 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
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S101/00—Printing
    • Y10S101/37—Printing employing electrostatic force

Definitions

  • This invention relates to electrostatic printing. More particularly it relates to an improved liquid developer composition for converting a latent electrostatic image into a visible image and to an improved process for converting the visual image into a permanent visual record.
  • the present invention constitutes an improvement over prior art liquid developers previously described. Instead of requiring the use of specially prepared adhesive containing strips or of relying on the absorbency of the transfer media, coupled with a separate aftertreatment to fix the image, we have now found that a suitable temporary visual image of the latent electrostatic image may be produced and then transferred to and fixed on a permanent record medium in a simple and direct manner.
  • liquid developer composition to be used in the development of a visual image from a latent electrostatic image comprised essentially of the following ingredients:
  • any opaque powdered solid material may be employed in our developer composition. It is merely required that the powder remain insoluble in the liquid components and that it be chemically inert with respect to them. Suitable powders are known in the art and we have found that carbon particles with a size between about .01 micron and 50 microns to be suitable. The particle size selected for any specific application is necessarily related to the sharpness of definition desired in the ultimate visual image. In one specific application we have found an average particle size of 12 microns satisfactory from the standpoint of definition of the image produced, while in others, carbon black of about 0.1 micron particle size have produced the desired result.
  • the high resistance liquid component of our composition is generally a hydrocarbon or substituted hydrocarbon such as carbon tetrachloride, kerosene, benzene, or toluene or indeed any other high resistance liquid hydrocarbon having a boiling point between about 70 C. and 200 C.
  • the third essential ingredient in our developer composition performs a variety of functions. It serves to disperse the finely divided opaque powder and also acts to fix the opaque powder particles onto the permanent record medium when the transfer to such medium is effected in the manner to be described. Accordingly, the third essential ingredient is chosen from materials which are non-adhesive, non-thermosetting and which soften without depolymerization on heating. Furthermore, it must be a material which maintains its filmforming properties on cooling and must be one which melts at a reasonable temperature, that is, one which melts below the charring point of the permanent transfer medium. It is further required that the third constituent be chosen from materials which do not react to any substantial extent with either the finely divided opaque powder or the high resistance liquid.
  • one class of materials possessing the desired combination of properties are those straight chain hydrocarbon polymers or chlorinated straight chain hydrocarbon polymers which are generally designated as polyethylenes and more particularly those polyethylenes having an average molecular weight in the range of 1500-5000, or chlorinated polyethylenes of the same molecular weight range.
  • the several ingredients may be combined in various proportions and we have found that amounts of opaque powder, e.g., charcoal or carbon black, up to 25% by weight; and amounts of polyethylene up to 20% by weight of the composition have produced entirely satisfactory images. Obviously, the proportions may be varied to suit any specific application and actually, we have obtained satisfactory images with as little as by Weight of the finely divided opaque powder.
  • opaque powder e.g., charcoal or carbon black
  • polyethylene up to 20% by weight of the composition
  • the several components of our liquid developer composition may be brought together in various ways.
  • One relatively simple method of forming the desired composition is to heat the three ingredients to the melting point of the polyethylene and then allow the composition to cool to room temperature.
  • amounts up to 100% of the high resistance liquid may be added to the opaque solid material and the opaque solid material may then be ball milled to the desired degree of fineness.
  • Any further addition of the high resistance liquid is then made and the resulting dispersion is then combined with the third essential ingredient of our composition, the thermoplastic material, for example a polyethylene having an average molecular weight in the range of 1500 to 5000.
  • the thermoplastic material for example a polyethylene having an average molecular weight in the range of 1500 to 5000.
  • the polyethylene Since the polyethylene is only slightly soluble in many of the liquid hydrocarbons possessing the required high resistance, it may be melted and poured into the mixture of opaque finely divided solid and high resistance liquid with vigorous agitation whereby a dispersion containing up to by weight of polyethylene may he obtained.
  • another method of preparing the composition is to melt the polyethylene in the high resistance hydrocarbon containing the finely divided opaque solid material. Whichever method is chosen for adding heated polyethylene to the remaining components, it has been observed that the polyethylene does not separate from the hydrocarbon constituent upon cooling. At high concentrations of polyethylene a thixotropic mixture is formed, that is, one which is gel-like until it is shaken, at which point it becomes more liquid.
  • the thermoplastic material may be melted and to the melt the finely divided opaque solid may be added with stirring to uniformly disperse the solid throughout the thermoplastic constituent.
  • This dispersion is added to the high resistance organic liquid, preferably in heated condition, to form a dispersion of the thermoplastic material and opaque finely divided solid in the high resistance liquid.
  • the specific ingredients employed are polyethylene, carbon particles and a hydrocarbon
  • the polyethylene appears to form a coating around the carbon particles and it is the coated particles which are dispersed in the hydrocarbon.
  • Still another method of preparation may be employed. In this method the solid opaque particles are added to the melted thermoplastic material and to improve the coat ing of the particles, we add a straight chain hydrocarbon wax such as a petroleum wax to the constituent.
  • the desired final composition is then formed by adding the high resistance organic liquid to the prepared mixture.
  • Example A developer was prepared by heating together 100 cc. of kerosene and 20 cc. of a composition formed by suspending one part by weight of carbon black in three parts by weight of kerosene. The ingredients were heated together to a temperature of about 110 C. In a separate vessel, 10 grams of a low molecular weight polyethylene (AC Grade No. 6, average molecular weight of 2000) were heated to melting, about 110 C., and quickly poured into the first mixture with constant stirring. The resultant composition was allowed to cool to room temperature and was thereafter employed in the electrostatic process described in the above identified copending patent applications of one of the present applicants. The development of a visual image from the latent electrostatic image was found to be entirely satisfactory.
  • a process for developing a visible image from a latent electrostatic image comprising: bringing a surface bearing the latent electrostatic image into contact with a body of a liquid developer composition consisting essentially of between about 5% and 25% by weight of an opaque solid electrostatically attractable particulate material, up to about 20% by weight of a solid polyethylene having a molecular weight between about 1500 and 5000 and a liquid hydrocarbon vehicle having a high electrical resistance, said particulate material having a particle size finer than about 50 microns and being present as solids in said composition.
  • the opaque solid is a carbonaceous solid material from the group con sisting of charcoal, carbon black and lampblack.
  • hydrocarbon is selected from the group consisting of kerosene, benzene, toluene and carbon tetrachloride.
  • the method of preparing a developer composition for electrostatic printing which comprises: forming a heated mixture consisting essentially of between about 5% and 25% by weight of an opaque solid particulate material, having a particle size finer than 50 microns and insoluble in the remainder of the composition; a polyethylene having a molecular weight between 1500 and 5000 and a liquid hydrocarbon vehicle, and permitting the heated mixture to cool.
  • the process for developing a visible image from an electrostatic charge image which comprises: applying a liquid developer composition to a surface bearing an electrostatic charge image, said liquid composition consisting essentially of between about 5% and 25% by weight of finely divided opaque powder particles finer than about 50 microns insoluble in and suspended in a liquid having a high electrical resistance and containing up to about 20% by weight of a polyethylene having a molecular weight of between 1500 and 5000.
  • a method of producing a developer composition for electrostatic printing which comprises: melting a low molecular weight polyethylene in a high resistance organic liquid, and adding thereto a finely divided opaque solid powder insoluble therein and having a particle size of less than 50 microns.
  • a method producing a developer composition for electrostatic printing which comprises: heating a suspension of a finely divided solid opaque powder having a particle size of less than 50 microns in a liquid having a high electrical resistance and in which the solid powder particles are insoluble and adding thereto a molten low molecular weight polyethylene with stirring to produce a uniform composition and permitting the product to cool.
  • a method of producing a developer composition for electrostatic printing comprising mixing finely divided opaque solid powder particles finer than 50 microns with a heated. thermoplastic material whereby the finely divided opaque solid powder particles become coated with the 2,89 1,91 1 5 thermoplastic material and dispersing the coated particles 2,618,574 in liquid hydrocarbon having a high electrical resistance.

Description

United States Patent DEVELOPER FOR ELECTROSTATIC PRINTING Edward F. Mayer, Cleveland, and Virgil E. Straughan,
Euclid, Ohio, assignors, by mesne assignments, to General Dynamics Corporation, San Diego, Calif., a corporation of Delaware No Drawing. Application June 6, 1955 Serial No. 513,566
9 Claims. (Cl. 252-621) This invention relates to electrostatic printing. More particularly it relates to an improved liquid developer composition for converting a latent electrostatic image into a visible image and to an improved process for converting the visual image into a permanent visual record.
Processes for forming a latent electrostatic image existing as an electrostatic charge pattern in a layer of material having a high resistance and for subsequently converting the latent electrostatic image into a visual image are known. One such process involves the use of a finely divided opaque solid in the form of a suspension in air as described in United States Patent 2,221,776. Another type of process in which a finely divided opaque solid is employed in the form of a dispersion in a high resistance liquid is disclosed in copending applications Serial No. 380,285, filed September 16, 1953, Serial No. 484,215, filed January 26, 1955, and Serial No. 486,995, filed February 8, 1955, by one of the present applicants. More recently, a similar liquid developer has been described by Metcalfe in the Journal of Scientific Instruments published by the Institute of Physics (London), volume 32, Number 2, February 1955, on pages 74 and 75.
Prior art dry powder methods require complicated equipment for suspending the powder and are considerably slower than the more recent wet methods. Although the wet developers constitute an improvement over earlier dry developers for the conversion of a latent electrostatic image to a visual image, none of the prior art developers is entirely satisfactory from the standpoint of producing a permanent visual record which does not smear or blur when rubbed. One attempted solution involves the use of adhesive coated or impregnated transfer media for transferring the pattern of the solid opaque particles constituting the visual image developed from the latent electrostatic image to a permanent recording means. The use of such transfer media constitutes a severe economic disadvantage in the prior art processes.
To overcome this, other prior art efforts have been directed to the transfer of the powder image onto an inexpensive absorbent transfer medium. The ultimate image so obtained was generally satisfactory for interpretation at the time of transfer but was found to blur and smear when rubbed. It was therefore found necessary to fix such images in an additional operation and one common technique was to spray an adhesive lacquer on the permanent record medium.
The present invention constitutes an improvement over prior art liquid developers previously described. Instead of requiring the use of specially prepared adhesive containing strips or of relying on the absorbency of the transfer media, coupled with a separate aftertreatment to fix the image, we have now found that a suitable temporary visual image of the latent electrostatic image may be produced and then transferred to and fixed on a permanent record medium in a simple and direct manner.
In accordance with our invention, we provide a liquid developer composition to be used in the development of a visual image from a latent electrostatic image comprised essentially of the following ingredients:
(1) A finely divided opaque powder,
(2) A high resistance liquid, and
(3) An ingredient which fixes the finely divided opaque powder image onto a permanent record medium when the particles constituting the temporary image are brought into contact with a permanent record medium under suitable conditions.
Virtually any opaque powdered solid material may be employed in our developer composition. It is merely required that the powder remain insoluble in the liquid components and that it be chemically inert with respect to them. Suitable powders are known in the art and we have found that carbon particles with a size between about .01 micron and 50 microns to be suitable. The particle size selected for any specific application is necessarily related to the sharpness of definition desired in the ultimate visual image. In one specific application we have found an average particle size of 12 microns satisfactory from the standpoint of definition of the image produced, while in others, carbon black of about 0.1 micron particle size have produced the desired result.
The high resistance liquid component of our composition is generally a hydrocarbon or substituted hydrocarbon such as carbon tetrachloride, kerosene, benzene, or toluene or indeed any other high resistance liquid hydrocarbon having a boiling point between about 70 C. and 200 C.
The third essential ingredient in our developer composition performs a variety of functions. It serves to disperse the finely divided opaque powder and also acts to fix the opaque powder particles onto the permanent record medium when the transfer to such medium is effected in the manner to be described. Accordingly, the third essential ingredient is chosen from materials which are non-adhesive, non-thermosetting and which soften without depolymerization on heating. Furthermore, it must be a material which maintains its filmforming properties on cooling and must be one which melts at a reasonable temperature, that is, one which melts below the charring point of the permanent transfer medium. It is further required that the third constituent be chosen from materials which do not react to any substantial extent with either the finely divided opaque powder or the high resistance liquid. We have found that one class of materials possessing the desired combination of properties are those straight chain hydrocarbon polymers or chlorinated straight chain hydrocarbon polymers which are generally designated as polyethylenes and more particularly those polyethylenes having an average molecular weight in the range of 1500-5000, or chlorinated polyethylenes of the same molecular weight range.
Other ingredients may be incorporated into our developer liquid in order to achieve additional advantages. Thus, we have found, that small amounts of the various waxes which form compatible mixtures with polyethylenes may be employed to assist in wetting the opaque finely divided solid material by the polyethylene. Typical compatible waxes have been found to include paraflin wax, beeswax, carnauba wax, and microcrystalline wax. Numerous other compatible waxes may be employed. We have also found that silica aerogel may be added to the composition to improve the viscosity of the liquid.
The several ingredients may be combined in various proportions and we have found that amounts of opaque powder, e.g., charcoal or carbon black, up to 25% by weight; and amounts of polyethylene up to 20% by weight of the composition have produced entirely satisfactory images. Obviously, the proportions may be varied to suit any specific application and actually, we have obtained satisfactory images with as little as by Weight of the finely divided opaque powder.
The several components of our liquid developer composition may be brought together in various ways. One relatively simple method of forming the desired composition is to heat the three ingredients to the melting point of the polyethylene and then allow the composition to cool to room temperature. In another method of preparation, amounts up to 100% of the high resistance liquid may be added to the opaque solid material and the opaque solid material may then be ball milled to the desired degree of fineness. Any further addition of the high resistance liquid is then made and the resulting dispersion is then combined with the third essential ingredient of our composition, the thermoplastic material, for example a polyethylene having an average molecular weight in the range of 1500 to 5000. When such a material constitutes the third ingredient, it may be combined with the dispersion by heating and melting it and pouring it into the dispersion. Since the polyethylene is only slightly soluble in many of the liquid hydrocarbons possessing the required high resistance, it may be melted and poured into the mixture of opaque finely divided solid and high resistance liquid with vigorous agitation whereby a dispersion containing up to by weight of polyethylene may he obtained.
Alternatively, another method of preparing the composition is to melt the polyethylene in the high resistance hydrocarbon containing the finely divided opaque solid material. Whichever method is chosen for adding heated polyethylene to the remaining components, it has been observed that the polyethylene does not separate from the hydrocarbon constituent upon cooling. At high concentrations of polyethylene a thixotropic mixture is formed, that is, one which is gel-like until it is shaken, at which point it becomes more liquid. In still another method of preparation, the thermoplastic material may be melted and to the melt the finely divided opaque solid may be added with stirring to uniformly disperse the solid throughout the thermoplastic constituent. This dispersion is added to the high resistance organic liquid, preferably in heated condition, to form a dispersion of the thermoplastic material and opaque finely divided solid in the high resistance liquid. When the specific ingredients employed are polyethylene, carbon particles and a hydrocarbon, the polyethylene appears to form a coating around the carbon particles and it is the coated particles which are dispersed in the hydrocarbon. Still another method of preparation may be employed. In this method the solid opaque particles are added to the melted thermoplastic material and to improve the coat ing of the particles, we add a straight chain hydrocarbon wax such as a petroleum wax to the constituent. The desired final composition is then formed by adding the high resistance organic liquid to the prepared mixture.
The following example will illustrate the preparation of one specific developed composition.
Example A developer was prepared by heating together 100 cc. of kerosene and 20 cc. of a composition formed by suspending one part by weight of carbon black in three parts by weight of kerosene. The ingredients were heated together to a temperature of about 110 C. In a separate vessel, 10 grams of a low molecular weight polyethylene (AC Grade No. 6, average molecular weight of 2000) were heated to melting, about 110 C., and quickly poured into the first mixture with constant stirring. The resultant composition was allowed to cool to room temperature and was thereafter employed in the electrostatic process described in the above identified copending patent applications of one of the present applicants. The development of a visual image from the latent electrostatic image was found to be entirely satisfactory.
The light and shadow pattern, developed from the latent electrostatic image when transferred to a permanent record medium, was converted to a permanent image which did not blur or smear after considerable rubbing, by heating the permanent record medium to a temperature slightly above the melting point of the polyethylene, that is to a temperature below about C. While we do not wish to be bound by any particular theory, it would appear that the developer composition is absorbed into the transfer medium and then fixed by the heat and that possibly the individual opaque particles are coated with a thin film of the polyethylene and bonded to the transfer medium by means of the film.
We claim:
1. In a process for developing a visible image from a latent electrostatic image the improvement which comprises: bringing a surface bearing the latent electrostatic image into contact with a body of a liquid developer composition consisting essentially of between about 5% and 25% by weight of an opaque solid electrostatically attractable particulate material, up to about 20% by weight of a solid polyethylene having a molecular weight between about 1500 and 5000 and a liquid hydrocarbon vehicle having a high electrical resistance, said particulate material having a particle size finer than about 50 microns and being present as solids in said composition.
2. The process of claim 1 in which the opaque solid is a carbonaceous solid material from the group con sisting of charcoal, carbon black and lampblack.
3. The process of claim 1 in which the opaque solid has a particle size of between about .01 and 50 microns.
4. The process of claim 1 in which the hydrocarbon is selected from the group consisting of kerosene, benzene, toluene and carbon tetrachloride.
5. The method of preparing a developer composition for electrostatic printing which comprises: forming a heated mixture consisting essentially of between about 5% and 25% by weight of an opaque solid particulate material, having a particle size finer than 50 microns and insoluble in the remainder of the composition; a polyethylene having a molecular weight between 1500 and 5000 and a liquid hydrocarbon vehicle, and permitting the heated mixture to cool.
6. The process for developing a visible image from an electrostatic charge image which comprises: applying a liquid developer composition to a surface bearing an electrostatic charge image, said liquid composition consisting essentially of between about 5% and 25% by weight of finely divided opaque powder particles finer than about 50 microns insoluble in and suspended in a liquid having a high electrical resistance and containing up to about 20% by weight of a polyethylene having a molecular weight of between 1500 and 5000.
7. A method of producing a developer composition for electrostatic printing which comprises: melting a low molecular weight polyethylene in a high resistance organic liquid, and adding thereto a finely divided opaque solid powder insoluble therein and having a particle size of less than 50 microns.
8. A method producing a developer composition for electrostatic printing which comprises: heating a suspension of a finely divided solid opaque powder having a particle size of less than 50 microns in a liquid having a high electrical resistance and in which the solid powder particles are insoluble and adding thereto a molten low molecular weight polyethylene with stirring to produce a uniform composition and permitting the product to cool.
9. A method of producing a developer composition for electrostatic printing comprising mixing finely divided opaque solid powder particles finer than 50 microns with a heated. thermoplastic material whereby the finely divided opaque solid powder particles become coated with the 2,89 1,91 1 5 thermoplastic material and dispersing the coated particles 2,618,574 in liquid hydrocarbon having a high electrical resistance.
References Cited in the file of this patent UNITED STATES PATENTS 5 Voet Nov. 9, 1948 Newman Aug. 15, 1950 Walton May 27, 1952 May Sept. 30, 1952 6 Pavlic Nov. 18, 1952 Walkup Mar. 5, 1957 FOREIGN PATENTS Great Britain Oct. 28, 1953 OTHER REFERENCES Metcalfe: Liquid Developers for Xerography, J. of Scientific Instruments, v01. 32, 1955, p. 74.

Claims (1)

1. IN A PROCESS FOR DEVELOPING A VISIBLE IMAGE FROM A LATENT ELECTROSTATIC IMAGE THE IMPROVEMENT WHICH COMPRISES: BRINGING A SURFACE BEARING THE LATENT ELECTROSTIC IMAGE INTO CONTACT WITH A BODY OF A LIQUID DEVELOPER COMPOSITION CONSISTING ESSENTIALLY OF BETWEEN ABOUT 5% AND 25% BY WEIGHT OF AN OPAQUE SOLID ELECTROSTATICALLY ATTRACTABLE PARTICULATE MATERTIAL, UP TO ABOUT 20% BY WEIGHT OF A SOLID POLYETHYLENE HAVING A MOLECULAR WEIGHT BETWEEN ABOUT 1500 AND 5000 AND A LIQUID HYDROCARBON VEHICLE HAVING A HIGH ELECTRICAL RESISTANCE, SAID PARTICULATE MATERIAL HAVING A PARTICLE SIZE FINER THAN ABOUT 50 MICRONS AND BEING PRESENT AS SOLIDS IN SAID COMPOSITION.
US513566A 1955-06-06 1955-06-06 Developer for electrostatic printing Expired - Lifetime US2891911A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US513566A US2891911A (en) 1955-06-06 1955-06-06 Developer for electrostatic printing

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US513566A US2891911A (en) 1955-06-06 1955-06-06 Developer for electrostatic printing

Publications (1)

Publication Number Publication Date
US2891911A true US2891911A (en) 1959-06-23

Family

ID=24043810

Family Applications (1)

Application Number Title Priority Date Filing Date
US513566A Expired - Lifetime US2891911A (en) 1955-06-06 1955-06-06 Developer for electrostatic printing

Country Status (1)

Country Link
US (1) US2891911A (en)

Cited By (41)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3032432A (en) * 1957-08-05 1962-05-01 Commw Of Australia Controlled tone development for electrophotography
US3041168A (en) * 1959-09-18 1962-06-26 Rca Corp Electrostatic printing
US3078231A (en) * 1959-05-13 1963-02-19 Commw Of Australia Controlled developer for use in electro-photography and electro-radiography
US3079272A (en) * 1959-04-24 1963-02-26 Rca Corp Method of developing an electrostatic image
US3080250A (en) * 1958-03-13 1963-03-05 Xerox Corp Self-tackifying xerographic toner
US3104169A (en) * 1956-06-27 1963-09-17 Commw Of Australia Production of printing blocks, resists, transparencies, prints and the like by electro-deposition
US3105821A (en) * 1960-02-04 1963-10-01 Rca Corp Electrostatic printing
US3135695A (en) * 1961-02-20 1964-06-02 Eastman Kodak Co Liquid developers for electrostatic photography
US3155531A (en) * 1958-09-23 1964-11-03 Harris Intertype Corp Meagnetic liquid developer and method for electrostatic images
US3198649A (en) * 1959-05-13 1965-08-03 Commw Of Australia Controlled and fixing liquid developer for electro-photography and electroradiography
US3218263A (en) * 1961-07-19 1965-11-16 Union Carbide Corp Gelled propellent for aerosol dispensers
US3241998A (en) * 1960-07-12 1966-03-22 Australia Res Lab Method of fixing xerographic images
US3241957A (en) * 1961-06-08 1966-03-22 Harris Intertype Corp Method of developing electrostatic images and liquid developer
US3251687A (en) * 1961-07-10 1966-05-17 Itek Corp Electrostatic printing process
US3256197A (en) * 1958-09-23 1966-06-14 Harris Intertype Corp Liquid developer for electrostatic charge images
US3278323A (en) * 1963-12-26 1966-10-11 Dick Co Ab Method of producing imaged spirit master directly from original
US3280741A (en) * 1958-12-31 1966-10-25 Burroughs Corp Electrostatic recording
US3334047A (en) * 1962-05-16 1967-08-01 Australia Res Lab Liquid dispersible toner for electrophotography
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
US3486922A (en) * 1967-05-29 1969-12-30 Agfa Gevaert Nv Development of electrostatic patterns with aqueous conductive developing liquid
US3512882A (en) * 1965-12-17 1970-05-19 Slaughter Byers Icenhour & Jac Electro photography system
US3516934A (en) * 1962-07-12 1970-06-23 Commw Of Australia Liquid developer for electrostatic images
US3669886A (en) * 1968-09-11 1972-06-13 Hunt Chem Corp Philip A Liquid developer for electrostatography
JPS4849445A (en) * 1971-10-22 1973-07-12
DE2352604A1 (en) * 1972-10-21 1974-05-02 Konishiroku Photo Ind TONER FOR THE DEVELOPMENT OF ELECTROSTATIC IMAGES
US3890240A (en) * 1966-11-28 1975-06-17 Pitney Bowes Inc Toner compositions and methods for their preparation
JPS5099331A (en) * 1973-12-28 1975-08-07
US3939087A (en) * 1973-11-19 1976-02-17 Pitney-Bowes, Inc. Toner compositions containing silane treated fumed silica
US4033890A (en) * 1975-02-26 1977-07-05 Fuji Photo Film Co., Ltd. Liquid developer for electrophotography
US4060493A (en) * 1975-07-10 1977-11-29 Ricoh Co., Ltd. Liquid electrostatic developer
US4081391A (en) * 1974-09-03 1978-03-28 Ricoh Co., Ltd. Liquid developer for use in electrophotography
US4157974A (en) * 1973-06-29 1979-06-12 Hoechst Aktiengesellschaft Electrophotographic liquid developer and process for the manufacture thereof
EP0013090A1 (en) * 1978-12-11 1980-07-09 DeSOTO, INC. Liquid developers for electrostatic images and method of producing them
US4275136A (en) * 1979-04-27 1981-06-23 Ishihara Sangyo Kaisha, Ltd. Liquid developer for color electrophotography
US4306009A (en) * 1979-12-13 1981-12-15 Nashua Corporation Liquid developer compositions with a vinyl polymeric gel
US4363863A (en) * 1979-12-13 1982-12-14 Nashua Corporation Liquid negative developer compositions for electrostatic copying containing polymeric charge control agent
US4374918A (en) * 1981-09-16 1983-02-22 Nashua Corporation Thermally stable liquid negative developer
US4659640A (en) * 1982-06-21 1987-04-21 Eastman Kodak Company Self-fixing liquid electrographic developers containing polyester toners and dispersed wax and processes for using the same
US4859559A (en) * 1987-03-18 1989-08-22 E. I. Du Pont De Nemours And Company Hydroxycarboxylic acids as adjuvants for negative liquid electrostatic developers
US5407771A (en) * 1984-12-10 1995-04-18 Indigo N.V. Toner and liquid composition using same

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2453558A (en) * 1945-11-28 1948-11-09 J M Huber Inc Printing ink
US2519321A (en) * 1946-03-18 1950-08-15 Columbias Ribbon And Carbon Mf Transfer ink
US2598332A (en) * 1952-05-27 Cold process transfer coating
US2612480A (en) * 1950-09-06 1952-09-30 Sun Chemical Corp Printing ink
US2618574A (en) * 1949-07-15 1952-11-18 Du Pont Surfaces of plastics coated with ink containing a chlorinated or chlorosulfonated polymer of ethylene
GB698994A (en) * 1951-12-14 1953-10-28 Battelle Development Corp Method and apparatus for developing electrostatic images
US2784109A (en) * 1950-09-18 1957-03-05 Haloid Co Method for developing electrostatic images

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2598332A (en) * 1952-05-27 Cold process transfer coating
US2453558A (en) * 1945-11-28 1948-11-09 J M Huber Inc Printing ink
US2519321A (en) * 1946-03-18 1950-08-15 Columbias Ribbon And Carbon Mf Transfer ink
US2618574A (en) * 1949-07-15 1952-11-18 Du Pont Surfaces of plastics coated with ink containing a chlorinated or chlorosulfonated polymer of ethylene
US2612480A (en) * 1950-09-06 1952-09-30 Sun Chemical Corp Printing ink
US2784109A (en) * 1950-09-18 1957-03-05 Haloid Co Method for developing electrostatic images
GB698994A (en) * 1951-12-14 1953-10-28 Battelle Development Corp Method and apparatus for developing electrostatic images

Cited By (44)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3104169A (en) * 1956-06-27 1963-09-17 Commw Of Australia Production of printing blocks, resists, transparencies, prints and the like by electro-deposition
US3032432A (en) * 1957-08-05 1962-05-01 Commw Of Australia Controlled tone development for electrophotography
US3080250A (en) * 1958-03-13 1963-03-05 Xerox Corp Self-tackifying xerographic toner
US3155531A (en) * 1958-09-23 1964-11-03 Harris Intertype Corp Meagnetic liquid developer and method for electrostatic images
US3311490A (en) * 1958-09-23 1967-03-28 Harris Intertype Corp Developing electrostatic charge image with a liquid developer of two immiscible phases
US3256197A (en) * 1958-09-23 1966-06-14 Harris Intertype Corp Liquid developer for electrostatic charge images
US3280741A (en) * 1958-12-31 1966-10-25 Burroughs Corp Electrostatic recording
US3079272A (en) * 1959-04-24 1963-02-26 Rca Corp Method of developing an electrostatic image
US3198649A (en) * 1959-05-13 1965-08-03 Commw Of Australia Controlled and fixing liquid developer for electro-photography and electroradiography
US3078231A (en) * 1959-05-13 1963-02-19 Commw Of Australia Controlled developer for use in electro-photography and electro-radiography
US3041168A (en) * 1959-09-18 1962-06-26 Rca Corp Electrostatic printing
US3105821A (en) * 1960-02-04 1963-10-01 Rca Corp Electrostatic printing
US3241998A (en) * 1960-07-12 1966-03-22 Australia Res Lab Method of fixing xerographic images
US3135695A (en) * 1961-02-20 1964-06-02 Eastman Kodak Co Liquid developers for electrostatic photography
US3241957A (en) * 1961-06-08 1966-03-22 Harris Intertype Corp Method of developing electrostatic images and liquid developer
US3251687A (en) * 1961-07-10 1966-05-17 Itek Corp Electrostatic printing process
US3218263A (en) * 1961-07-19 1965-11-16 Union Carbide Corp Gelled propellent for aerosol dispensers
US3334047A (en) * 1962-05-16 1967-08-01 Australia Res Lab Liquid dispersible toner for electrophotography
US3516934A (en) * 1962-07-12 1970-06-23 Commw Of Australia Liquid developer for electrostatic images
US3278323A (en) * 1963-12-26 1966-10-11 Dick Co Ab Method of producing imaged spirit master directly from original
US3391014A (en) * 1964-04-27 1968-07-02 Harris Intertype Corp Liquid development of electrostatic images
US3391015A (en) * 1964-04-27 1968-07-02 Harris Intertype Corp Liquid development of electrostatic images with carbon black and a solid organic pigment
US3472676A (en) * 1965-11-18 1969-10-14 Gevaert Photo Prod Nv Process for developing electrostatic charge patterns
US3512882A (en) * 1965-12-17 1970-05-19 Slaughter Byers Icenhour & Jac Electro photography system
US3890240A (en) * 1966-11-28 1975-06-17 Pitney Bowes Inc Toner compositions and methods for their preparation
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
JPS4849445A (en) * 1971-10-22 1973-07-12
DE2352604A1 (en) * 1972-10-21 1974-05-02 Konishiroku Photo Ind TONER FOR THE DEVELOPMENT OF ELECTROSTATIC IMAGES
US4157974A (en) * 1973-06-29 1979-06-12 Hoechst Aktiengesellschaft Electrophotographic liquid developer and process for the manufacture thereof
US3939087A (en) * 1973-11-19 1976-02-17 Pitney-Bowes, Inc. Toner compositions containing silane treated fumed silica
JPS5099331A (en) * 1973-12-28 1975-08-07
JPS553696B2 (en) * 1973-12-28 1980-01-26
US4081391A (en) * 1974-09-03 1978-03-28 Ricoh Co., Ltd. Liquid developer for use in electrophotography
US4033890A (en) * 1975-02-26 1977-07-05 Fuji Photo Film Co., Ltd. Liquid developer for electrophotography
US4060493A (en) * 1975-07-10 1977-11-29 Ricoh Co., Ltd. Liquid electrostatic developer
EP0013090A1 (en) * 1978-12-11 1980-07-09 DeSOTO, INC. Liquid developers for electrostatic images and method of producing them
US4275136A (en) * 1979-04-27 1981-06-23 Ishihara Sangyo Kaisha, Ltd. Liquid developer for color electrophotography
US4306009A (en) * 1979-12-13 1981-12-15 Nashua Corporation Liquid developer compositions with a vinyl polymeric gel
US4363863A (en) * 1979-12-13 1982-12-14 Nashua Corporation Liquid negative developer compositions for electrostatic copying containing polymeric charge control agent
US4374918A (en) * 1981-09-16 1983-02-22 Nashua Corporation Thermally stable liquid negative developer
US4659640A (en) * 1982-06-21 1987-04-21 Eastman Kodak Company Self-fixing liquid electrographic developers containing polyester toners and dispersed wax and processes for using the same
US5407771A (en) * 1984-12-10 1995-04-18 Indigo N.V. Toner and liquid composition using same
US4859559A (en) * 1987-03-18 1989-08-22 E. I. Du Pont De Nemours And Company Hydroxycarboxylic acids as adjuvants for negative liquid electrostatic developers

Similar Documents

Publication Publication Date Title
US2891911A (en) Developer for electrostatic printing
US2899335A (en) Process for developing electrostatic
US2877133A (en) Electrostatic photography
US2663636A (en) Electrophotographic plate and method of producing same
US2659670A (en) Method of developing electrostatic images
US3010842A (en) Development of electrostatic images
US2890174A (en) Xerographic developer composition
US3053688A (en) Electrostatic printing
GB2176904A (en) Preparing toner particles for liquid developer compositions
GB1586735A (en) Toner for developing electrostatic images
US3607261A (en) Inorganic crystalline binders for electrophotographic plates
US3080250A (en) Self-tackifying xerographic toner
US3377286A (en) Developer powder containing black magnetic iron oxide
US3150976A (en) Electrostatic printing
US3247007A (en) Method of developing latent electro- static images ushng solid developer body and related solvent
US3054692A (en) Novel hectograph methods
US3076722A (en) Electrostatic printing
EP0070841B1 (en) Dry toner and method of making same
US3198649A (en) Controlled and fixing liquid developer for electro-photography and electroradiography
US3166510A (en) Electrographic printing ink, process for the manufacture thereof, and method of electrostatic printing therewith
US3105821A (en) Electrostatic printing
GB2053501A (en) Dry magnetic pressure-fixable developing powder for electrostatic images
US3415186A (en) Duplicating system
US3251688A (en) Liquid transfer development
EP0066955B1 (en) Dielectric record material