US2993787A - Electrostatic printing - Google Patents

Electrostatic printing Download PDF

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Publication number
US2993787A
US2993787A US604046A US60404656A US2993787A US 2993787 A US2993787 A US 2993787A US 604046 A US604046 A US 604046A US 60404656 A US60404656 A US 60404656A US 2993787 A US2993787 A US 2993787A
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United States
Prior art keywords
coating
image
electrostatic
powder
photoconducting
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
US604046A
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English (en)
Inventor
Jr Meyer L Sugarman
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.)
RCA Corp
Original Assignee
RCA 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
Priority to BE541668D priority Critical patent/BE541668A/xx
Priority to GB24904/55A priority patent/GB837545A/en
Priority to DER17345A priority patent/DE974162C/de
Priority to FR1176922D priority patent/FR1176922A/fr
Application filed by RCA Corp filed Critical RCA Corp
Priority to US604046A priority patent/US2993787A/en
Priority to CH478761A priority patent/CH374796A/fr
Application granted granted Critical
Publication of US2993787A publication Critical patent/US2993787A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G5/00—Recording members for original recording by exposure, e.g. to light, to heat, to electrons; Manufacture thereof; Selection of materials therefor
    • G03G5/02—Charge-receiving layers
    • G03G5/04—Photoconductive layers; Charge-generation layers or charge-transporting layers; Additives therefor; Binders therefor
    • G03G5/05—Organic bonding materials; Methods for coating a substrate with a photoconductive layer; Inert supplements for use in photoconductive layers
    • G03G5/0528—Macromolecular bonding materials
    • G03G5/0557—Macromolecular bonding materials obtained otherwise than by reactions only involving carbon-to-carbon unsatured bonds
    • G03G5/0585—Cellulose and derivatives
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G5/00—Recording members for original recording by exposure, e.g. to light, to heat, to electrons; Manufacture thereof; Selection of materials therefor
    • G03G5/02—Charge-receiving layers
    • G03G5/04—Photoconductive layers; Charge-generation layers or charge-transporting layers; Additives therefor; Binders therefor
    • G03G5/05—Organic bonding materials; Methods for coating a substrate with a photoconductive layer; Inert supplements for use in photoconductive layers
    • G03G5/0528—Macromolecular bonding materials
    • G03G5/0532—Macromolecular bonding materials obtained by reactions only involving carbon-to-carbon unsatured bonds
    • G03G5/0542—Polyvinylalcohol, polyallylalcohol; Derivatives thereof, e.g. polyvinylesters, polyvinylethers, polyvinylamines
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G5/00—Recording members for original recording by exposure, e.g. to light, to heat, to electrons; Manufacture thereof; Selection of materials therefor
    • G03G5/02—Charge-receiving layers
    • G03G5/04—Photoconductive layers; Charge-generation layers or charge-transporting layers; Additives therefor; Binders therefor
    • G03G5/05—Organic bonding materials; Methods for coating a substrate with a photoconductive layer; Inert supplements for use in photoconductive layers
    • G03G5/0528—Macromolecular bonding materials
    • G03G5/0592—Macromolecular compounds characterised by their structure or by their chemical properties, e.g. block polymers, reticulated polymers, molecular weight, acidity
    • 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
    • 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 and particularly, but not necessarily exclusively, to improved compositions and improved methods for producing recording elements especially adapted for use in electrostatic printing processes.
  • An electrostatic printing process is that type of process for producing a visible record, reproduction or copy which includes an an intermediate step, converting a light image or electrical signal into an electrostatic charge pattern on an electrically-insulating layer.
  • the process may also include the conversion of the charge pattern into a visible image which may be a substantially faithful reproduction of an original except that it may be a different size, color or contrast range.
  • a typical electrostatic printing process may include preparing an electrophotographic recording element, for example, by coating a surface of a backing with a photoconducting insulating material such as selenium, anthracene, or zinc oxide dispersed in an electrically-insulating, film-forming, water insoluble vehicle such as a silicone resin.
  • An over-all'electrostatic charge is produced on the surface of the photoconducting material and a light image is focused on the charged surface, discharging the portions irradiated by the light rays, while leaving the remainder of the surface in a charged condition thereby forming an electrostatic image.
  • the electrostatic image is rendered visible by applying a developer powder which is held electrostatically to the charged areas of the sheet.
  • the powder image thus formed may be fixed directly to the photoconductive coating or it may be transferred to another surface upon which the reproduced image may be desired and then fixed thereon.
  • the recording element for electrostatic printing is prepared by first mixing the finely-divided photoconductor and the electricallyinsulating, film-forming, water-insoluble vehicle with a volatile organic solvent for the vehicle, for example, by mixing zinc oxide and a silicone resin with toluene. This mixture is coated on the backing member by any standard coating procedure, dried and then cut or punched to a desired size.
  • a recording element for electrostatic printing is prepared by mixing a finely-divided photoconductor with an aqueous dispersion of an electrically-insulating, film-forming, water insoluble vehicle, for example, by mixing zinc oxide with polyvinyl acetate resin dispersed in water.
  • This mixture is coated on a backing member by any standard coating procedure, dried and then cut or punched to a desired size. During the drying step, the solute is removed and the dispersed particles coalesce to produce a continuous phase for suspending the photoconductor particles.
  • This second prior art process depends on maintaining a suitable dispersion of normally incompatible substances. This is difficult, particularly in the presence of high pigment concentrations such as used in the usual coatings for electrostatic printing.
  • An object of this invention is to provide improved electrostatic printing processes and improved recording elements therefor.
  • a further object is to provide improved compositions for producing recording elements for electrostatic printmg.
  • Another object is to provide recording elements for electrostatic printing having a hydrophilic surface which is particularly adaptable for producing lithographic printing masters by an electrostatic printing process without further chemical processing.
  • the recording elements of the invention comprise a photoconducting layer including a major proportion of a finely-divided photoconductor, such as a photoconductive zinc oxide, dispersed in a minor proportion of a water-soluble, electrically-insulating, film-forming vehicle such as polyvinyl alcohol.
  • the photoconducting layer may be self-supporting but is preferably supported on a backing such as paper.
  • the photoconducting layer may include also a bivalent or multivalent salt to make the layer particularly useful in preparing lithographic printing plates without further chemical processing.
  • Vehicle of the recording element is preferably insolubilized, as by polymerization, prior to use in electrostatic printing.
  • the invention further includes electrostatic printing processes comprising the steps of producing an electrostatic charge image corresponding to an applied light image, developing said electrostatic image with a finelydivided developer substance and then fixing said developed image substantially in situ.
  • the photoconducting coating may be dried inunediately before the step of charging.
  • FIGURE 1 is a partially-schematic, sectional view of an apparatus for producing a blanket electrostatic charge upon a recording element produced by the method of the invention.
  • FIGURE 2 is a partially-sectional, elevational view of an apparatus for projecting a light image upon the charged recording element of FIGURE 1, and
  • FIGURE 3 is a sectional view of an apparatus for developing an electrostatic image upon the recording element of FIGURE 2.
  • Example 1 Prepare a mixture of the following composition:
  • the polyvinyl alcohol is dissolved in the water-methanol mixture, and the zinc oxide dispersed therein as by blending in for 5 minutes in a high speed blendor.
  • the blended mixture is coated on a paper backing to a thickness to provide a final dry coating of about 0.0005 inch.
  • the coating is thoroughly dried and then cut or punched to the desired shape and size.
  • the product is an electrophotographic recording element comprising a paper backing having a white, matte, photoconducting coating thereon, which element is especially adapted for use in electro static printing.
  • the backing of the example is paper, any substrate may be used.
  • cellulosic material such as cellophane or cellulose acetate, a metallic material such as copper, aluminum or brass, or a mineral material such as glass or mica.
  • the substrate or backing may be in any desired shape or configuration. It is preferred, although not necessary, that the substrate have a higher electrical conductivity than the final photoconducting coating.
  • the coating applied to the backing will determine the spectral response, the speed of response and the contrast characteristic of the printing base.
  • almost any spectral response, speed of response or contrast characteristic may be obtained within wide ranges.
  • Almost any powdered pho-tocondnctor having sufliciently high value of surface photoconductivity may be used in the coating, for example, the photoconductive oxides, sulphides, selenides, tellurides, and iodides of cadmium, mercury, antimony, bismuth, thallium, molybdenum, aluminum, lead or zinc.
  • arsenic trisulphide, cadmium arsenide, lead chromate or selenium may be used.
  • It is preferable for the photoconductor to have a high electrical resistivity in the darkness. Mixtures of one or more photoconductors may be used.
  • the particular photoconductor utilized determines the spectral response of the recording element.
  • the color of the photoconductor indicates approximately the location or" the absorption edge of the photoconductor and of the recording element. Most photoconductors absorb light in the shorter wavelengths. When longer wavelengths are used, a value is reached where the absorption drops off sharply and the photoconductor ceases to absorb radiation. This value is called the absorption edge of the material. It is of particular advantage that by making a proper selection of the photoconductor that one may obtain a printing base with any desired light absorption characteristic and thereby desired spectral sensitivity. For example, thallium iodide has a peak response around 4130 A. Silver sulphide has a peak response around 13500 A., while other photoconductors may have their peak responses at other wavelengths in the electromagnetic spectrum and over a narrow or wide band of frequencies.
  • the electrically-insulating, film-forming vehicle is an essential part of the composition and may be any one of a number of substances which form dispersions in aqueous media. Most desirable is a vehicle having a high dielectric constant and high dielectric strength. These materials may be any water soluble natural or synthetic resin or gum, for example polyvinyl alcohol, hydroxyethyl cellulose and carboxymethyl cellulose, gum arabic or guar gum.
  • plasticizer may be used in conjunction with the vehicle to impart flexibility and pliability to the final coating.
  • the choice of the plasticizer is determined by the vehicle used.
  • the quantity of plasticizer used is determined by the degree of flexibility required in the coating and by the particular polymer used as the vehicle. This quantity may be present in an amount between zero and eighty percent by weight of the vehicle.
  • the proportion of powdered photoconductor to vehicle in the final coating may vary over a very wide range although the photoconductor should comprise a major proportion of the composition.
  • the preferred ranges are 100 to 900 parts by weight of photoconductor to 100 parts by weight of vehicle. The optimum proportion will depend upon the nature of the photoconductor, the nature of the vehicle and the results desired.
  • the speed of response of the printing base particularly depends upon the nature of the photocondnctive material, the nature of the vehicle and the ratio by weight of photoconductor to. vehicle. Since the speed of response depends upon a number of characteristics, almost any de- 4 sired response may be obtained by the proper selection of materials and composition.
  • a proper selection of materials and compositions will also determine how long an electrostatic image may be stored on the surface of the photoconductive coating since storage of the electrostatic image depends upon the electrical resistivity of the material. Generally, the higher the resistivity of the coating the longer the storage time for the material.
  • the mixtures of the invention may be coated on the backing by any convenient method.
  • the coating may be sprayed on or flowed on or the backing may be dipped into the mixtures.
  • the coating is dried.
  • the drying temperature is not critical. 'It should be sufiiciently high to evaporate the water but not so high as to burn or char the backing or constituents in the coating.
  • the coating of the final product may be any thickness. However, it is preferred that the coating thickness be about 0.0003 to about 0.002 inch. For the coating of the example, a coating 0.0005 inch thick is preferred.
  • a dye for sensitizing the photoconductive coating may be incorporated into the coating when the dispersions are prepared or after the coatings have dried.
  • the recording element of Example 1 which comprises a backing 21 having a. photoconducting coating 23, may be utilized in an electrostatic printing process according to the following steps. If the recording element is stored at low humidity it may be used directly. Otherwise, it may be desirable to dry the photoconducting coating as by heating or dessicating for a short time.
  • the recording element is placed with the backing 21 upon a grounded metal plate 25 and an electrostatic charging device 61 passed in darkness over the photoconducting coating 23 to provide an electrostatic charge thereon.
  • the charging device 61 may comprise an array of fine wires 53 mounted near the grounded metal plate 25. A source of DC. high voltage is connected between the wires 53 and the grounded plate 25 to provide a negative charge on the wires with respect to the grounded plate 25.
  • the voltage should be sufficiently high to cause a corona discharge adjacent the wires.
  • the recording element passing under the charging device 61 becomes charged negatively.
  • the apparatus and process may produce a blanket positive charge if the polarity of the wires 53 is positive with respect to the grounded plate 25.
  • the next step in the processing is to discharge selected parts of the charged surface of the printing base in order to produce an electrostatic image thereon.
  • this may be accomplished by exposing the printing base to an optical image derived, for example, from a projector 59 containing a photographic transparency of the subject matter to be printed.
  • the optical image is focused on the charged surface of the photoconductive coating 23.
  • the subject matter to be printed may, however, be any subject used in ordinary photographic processes. Any type of electromagnetic radiation may be used depending on the spectral sensitivity of the photoconductive coating 23. For example, visible light, infra red, ultra violet, and X-rays may be used.
  • the electrostatic image may be stored for a time if desired. Ordinarily the next step is to develop the electrostatic image with a finely-divided developer substance such as a finely-divided powder or an ink mist.
  • development of the electrostatic image is preferably accomplished by maintaining the recording element in darkness and passing a developer brush 55 containing a developer powder across the surface of photoconductive coating 23 bearing the electrostatic image. Areas of developer powder 27 are deposited on those areas of the surface retaining an electrostatic charge.
  • the developer brush comprises a mixture of magnetic carrier particles, for example, powdered iron and the developer powder. The mixture is secured in a magnetic field by a magnet 57 to form a developer brush.
  • a preferred carrier material for the developer mix consists of alcoholized iron, that is, iron patricles free from grease and other impurities soluble in alcohol. These iron particles are preferably relatively small in size, being in their largest dimension about .002 to .008". Satisfactory results are also obtained using a carrier consisting of iron particles of a somewhat wider range of sizes up to about .001 to .020".
  • a preferred developer powder may be prepared as follows.
  • a mixture comprising 200 grams of 200 mesh Piccolastic resin 4358 (an elastic thermoplastic resin composed of polymers of styrene, substituted styrene and its homologs) marketed by the Pennsylvania Industrial Company, Clairton, Pa., 12 grams of Carbon Black G, marketed by the Eimer and Amend Co., New York, N.Y., 12 grams of spirit Nigrosine S.S.B., marketed by the Allied Chemical and Dye Co., New York, N.Y., and 8 grams of Iosol Black, marketed by the Allied Chemical and Dye Co., New York, N.Y., are thoroughly mixed in a stainless steel beaker at about 200 C.
  • the mixing and heating should be done in as short a time as possible.
  • the melt is poured onto a brass tray and allowed to cool and harden.
  • the hardened mix is then broken up and ball-milled for about 20 hours.
  • the powder is screened through a 200 mesh screen and is then ready for use as a developer powder. This powder takes on a positive electrostatic charge when mixed with glass beads or iron powder. It therefore develops an electrostatic image composed of negative charges.
  • Two to four grams of the developer powder and 100 grams of the magnetic carrier material are blended together giving the completed developer mix. Other ratios may be used.
  • the developer powder may be chosen from a large class of materials.
  • the developer powder is preferably electrically charged to aid in the development of the electrostatic latent image.
  • the powder may be electrically charged because the powder (1) is electroscopic, or (2) has interacted with other particles with which it is triboelectrically active or (3) has been charged from an electric source such as a corona discharge.
  • suitable developer powders are powdered zinc, powdered copper, carbon, sulphur, natural and synthetic resins or mixtures thereof.
  • the developer powder may be applied to the image in other ways, for example, it may be dusted on to the image, or it may be mixed with glass beads or other suitable carrier particles and then bringing the mixture into contact with the surface of the printing base.
  • the beads serve merely as a temporary carrier, releasing the powder particles upon contact with the charged surface.
  • the type of powder described is a positively-charged powder and will adhere readily to negatively charged areas of the electrostatic image.
  • the developed image described the developed areas of the image correspond to the non-illuminated portions of the optical image. If the printing base is charged positively, and the same steps are carried through as above described, a reverse image is obtained. If a negatively charged powder is used in place of the positively charged powder, then a reverse image is obtained in the alternative case.
  • the developed image 27 is now fixed to the photoconducting coating 23. If the developer powder or vehicle in the photoconducing coating 23 has a relatively low melting point, the image may be fixed by heating, for example, with an infra red lamp to fuse the powder to the surface. The powder image is preferably fused through the photoconductive coating 23. Sulphur or synthetic resin powders may be fixed in this way. Alternatively, the powder image 27 may be pressed into the coating 23. Another method of fixing the powder image 27 is to apply a thin coating of a solvent for the material of the powder image 27. The solvent may soften the developer powder particles and cause them to adhere to one another and to the coating 23. Alternatively, a solvent may be used to soften the photoconducting coating 23 and cause the developer powder particles to adhere thereto. Upon standing and preferably with the application of a slight amount of heat the solvent is evaporated from the printing base.
  • Example 2 is as follows:
  • the dimethylolurea acts as a polymerizing agent for the polyvinyl alcohol, rendering the dried coating water insoluble upon aging.
  • the ammonium nitrate acts as a polymerization catalyst.
  • Example 2 The mixture of Example 2 is coated on a backing and dried as described for the coating of Example 1. It may then be used in electrophotography as described in the foregoing description.
  • Example 3 Another formulation according to the invention which is particularly useful in producing lithographic printing masters is as follows:
  • the zinc acetate functions to render the photoconducting coating receptive to water after the image is fixed to the coating.
  • other water soluble bivalent metal salts may be used, for example, the water soluble acetates, nitrates, chlorides and formates of barium, cadmium, calcium, cobalt, copper, iron, lead, magnesium, nickel, strontium and zinc may be used.
  • Ordinarily salts are used in concentrations between 5 and 15% by weight, however, in some cases they may be used in concentrations as high as 25% by weight.
  • All the water soluble salts of bivalent metals selected from groups 1, 2, 4, 7 and 8 from the periodic table which are sufficiently stable in water solution may be used.
  • water soluble multivalent metal formate or acetate when used in conjunction with a water soluble alkaline metal or ammonium formate or acetate may be used.
  • the developer powder used to prepare lithographic printing plates is a hydrophobic material such as the preferred developer powder described above.
  • the recording element may be used for lithographic printing without further treatment.
  • the recording element is swabbed with a wetting solution such as Platex and then printing in conjunction with a fountain solution such as Repelex in normal dilution. Platex and Repelex (trademarks), are marketed by the Addressograph-Multigraph Corporation, Cleveland, Ohio.
  • Example 4.-Another formulation according to the invention is as follows:
  • compositions and methods for using these compositions to produce electrophotographic recording elements for electrostatic printing are simple and economical to prepare and use, do not present a fire or a health hazard of organic or highly volatile solvent coatings and may be used in continuous web coating equipment designed for silver halide emulsions.
  • improved electrostatic printing processes including the electrophotographic recording elements of the invention.
  • An article of manufacture adapted for use in elec- 8 trostatic printing comprising a backing sheet coated with a photoconducting composition including about 100 to 900 parts by weight of photoconducting zinc oxide and about 100 parts by weight of a vehicle consisting essentially of about 5% to 25% by weight of zinc acetate and about 95% to about by weight of resinous polyvinyl alcohol.
  • a photoconducting composition for use in electrostatic printing comprising about 100 to 900 parts by weight of photoconducting zinc oxide and about 100 parts by weight of a vehicle consisting essentially of about 5% to 25 by weight of Zinc acetate and about to 75 by weight of resinous polyvinyl alcohol.

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  • Physics & Mathematics (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • General Physics & Mathematics (AREA)
  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Photoreceptors In Electrophotography (AREA)
  • Printing Plates And Materials Therefor (AREA)
US604046A 1955-08-30 1956-08-14 Electrostatic printing Expired - Lifetime US2993787A (en)

Priority Applications (6)

Application Number Priority Date Filing Date Title
BE541668D BE541668A (fr) 1955-08-30
GB24904/55A GB837545A (en) 1955-08-30 1955-08-30 Improvements in the preparation of planographic plates
DER17345A DE974162C (de) 1955-08-30 1955-08-31 Verfahren zur Herstellung von lithographischen Druckplatten nach dem elektrostatischen Verfahren
FR1176922D FR1176922A (fr) 1955-08-30 1955-09-09 Impression électrostatique
US604046A US2993787A (en) 1955-08-30 1956-08-14 Electrostatic printing
CH478761A CH374796A (fr) 1955-08-30 1961-04-24 Procédé de fabrication d'une pièce de tricot, dispositif pour la mise en oeuvre de ce procédé et pièce de tricot obtenue au moyen de ce procédé

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB24904/55A GB837545A (en) 1955-08-30 1955-08-30 Improvements in the preparation of planographic plates
US604046A US2993787A (en) 1955-08-30 1956-08-14 Electrostatic printing

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Publication Number Publication Date
US2993787A true US2993787A (en) 1961-07-25

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US604046A Expired - Lifetime US2993787A (en) 1955-08-30 1956-08-14 Electrostatic printing

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US (1) US2993787A (fr)
BE (1) BE541668A (fr)
FR (1) FR1176922A (fr)
GB (1) GB837545A (fr)

Cited By (30)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3106158A (en) * 1962-01-22 1963-10-08 Rca Corp Method of preparing lithographic printing plates
US3107169A (en) * 1958-12-18 1963-10-15 Bruning Charles Co Inc Processes of producing lithographic electrostatic printing plates
US3128204A (en) * 1956-11-14 1964-04-07 Agfa Ag Process of preparing photoconductive layers for electrophotography
US3152969A (en) * 1960-07-28 1964-10-13 Eastman Kodak Co Photoconductolithography employing hydrophobic images
US3160503A (en) * 1959-06-22 1964-12-08 Warren S D Co Electrophotographic recording paper and method of making
US3192043A (en) * 1960-10-07 1965-06-29 Commw Of Australia Method for developing and fixing electrostatic images in initially partially cured base elements
US3198110A (en) * 1959-06-15 1965-08-03 Minnesota Mining & Mfg Lithographic printing plate with polymer coated metal image
US3212887A (en) * 1961-04-07 1965-10-19 Minnesota Mining & Mfg Laterally disposed coterminously adjacent multicolor area containing graphic reproduction receptor and electrophotographic process of using same
US3214272A (en) * 1960-05-10 1965-10-26 Method of recording still optical images by means of a photocondugtive layer using thermoplastic imagewise deformation of the image layer
US3251687A (en) * 1961-07-10 1966-05-17 Itek Corp Electrostatic printing process
US3256811A (en) * 1964-09-09 1966-06-21 Dick Co Ab Method for the preparation of thermographic offset masters
US3257304A (en) * 1961-11-27 1966-06-21 Minnesota Mining & Mfg Process of electrodepositing insulative material on photoconductive copysheet
US3272121A (en) * 1963-02-14 1966-09-13 Plastic Coating Corp Lithographic printing plate prepared by photoelectrostatic reproduction, a method for its production and a method for lithographic printing
US3280741A (en) * 1958-12-31 1966-10-25 Burroughs Corp Electrostatic recording
US3323451A (en) * 1965-02-24 1967-06-06 Addressograph Multigraph Process and composition for producing planographic photoelectrostatic printing plates
US3364857A (en) * 1966-02-02 1968-01-23 Addressograph Multigraph Duplicating
US3390634A (en) * 1966-06-08 1968-07-02 Addressograph Multigraph Direct lithography master making
US3451336A (en) * 1966-01-13 1969-06-24 Addressograph Multigraph Master making and duplicating machine
US3460476A (en) * 1965-12-27 1969-08-12 Xerox Corp Imaging process
US3460963A (en) * 1964-05-25 1969-08-12 Lumiere Soc Process for the manufacture of an electrophotographic material
US3471625A (en) * 1957-02-15 1969-10-07 Harris Intertype Corp Electrophotographic coating containing finely divided photoconductor in a synthetic polymer having ionizable functional groups
US3489559A (en) * 1965-05-28 1970-01-13 Mead Corp Components for electrophotographic compositions and processes
US3501295A (en) * 1966-06-17 1970-03-17 Riegel Paper Corp Electrophotographic reproduction system utilizing lightweight copy papers
US3507693A (en) * 1967-11-13 1970-04-21 Yasuo Ueda Method of producing an electrophotographic plate
US3510299A (en) * 1967-06-26 1970-05-05 Clifford E Herrick Jr Method and material for the production of continuous - tone electrophotographic images
US3521560A (en) * 1966-10-20 1970-07-21 Addressograph Multigraph Lithographic printing
US3880514A (en) * 1973-09-14 1975-04-29 Coulter Information Systems Ion producing source for electrostatic recording apparatus
US3971870A (en) * 1971-07-27 1976-07-27 Semi-Elements, Inc. Semiconductor device material
US4123271A (en) * 1974-01-22 1978-10-31 Mita Industrial Company, Limited Alkali metal dichromate as memory resistance improver for zinc oxide photoconductors in electrostatic photography
US4434218A (en) 1979-01-24 1984-02-28 Konishiroku Photo Industry Co., Ltd. Photosensitive composition for electrophotography

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SE430546B (sv) * 1975-11-17 1983-11-21 Coulter Systems Corp Sett for framstellning av en direkt bildalstrande bojlig tryckplat att anvendas vid offset- eller liknande litografisk tryckning

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US1635110A (en) * 1926-02-08 1927-07-05 John W Beach Paint
US1700404A (en) * 1926-03-11 1929-01-29 Alfred P Goodell Water paint
US2236061A (en) * 1937-05-27 1941-03-25 Du Pont Method of making films, threads, and the like
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US3471625A (en) * 1957-02-15 1969-10-07 Harris Intertype Corp Electrophotographic coating containing finely divided photoconductor in a synthetic polymer having ionizable functional groups
US3107169A (en) * 1958-12-18 1963-10-15 Bruning Charles Co Inc Processes of producing lithographic electrostatic printing plates
US3280741A (en) * 1958-12-31 1966-10-25 Burroughs Corp Electrostatic recording
US3198110A (en) * 1959-06-15 1965-08-03 Minnesota Mining & Mfg Lithographic printing plate with polymer coated metal image
US3160503A (en) * 1959-06-22 1964-12-08 Warren S D Co Electrophotographic recording paper and method of making
US3214272A (en) * 1960-05-10 1965-10-26 Method of recording still optical images by means of a photocondugtive layer using thermoplastic imagewise deformation of the image layer
US3152969A (en) * 1960-07-28 1964-10-13 Eastman Kodak Co Photoconductolithography employing hydrophobic images
US3192043A (en) * 1960-10-07 1965-06-29 Commw Of Australia Method for developing and fixing electrostatic images in initially partially cured base elements
US3212887A (en) * 1961-04-07 1965-10-19 Minnesota Mining & Mfg Laterally disposed coterminously adjacent multicolor area containing graphic reproduction receptor and electrophotographic process of using same
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US3257304A (en) * 1961-11-27 1966-06-21 Minnesota Mining & Mfg Process of electrodepositing insulative material on photoconductive copysheet
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US3256811A (en) * 1964-09-09 1966-06-21 Dick Co Ab Method for the preparation of thermographic offset masters
US3323451A (en) * 1965-02-24 1967-06-06 Addressograph Multigraph Process and composition for producing planographic photoelectrostatic printing plates
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US3364857A (en) * 1966-02-02 1968-01-23 Addressograph Multigraph Duplicating
US3390634A (en) * 1966-06-08 1968-07-02 Addressograph Multigraph Direct lithography master making
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US3521560A (en) * 1966-10-20 1970-07-21 Addressograph Multigraph Lithographic printing
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US3880514A (en) * 1973-09-14 1975-04-29 Coulter Information Systems Ion producing source for electrostatic recording apparatus
US4123271A (en) * 1974-01-22 1978-10-31 Mita Industrial Company, Limited Alkali metal dichromate as memory resistance improver for zinc oxide photoconductors in electrostatic photography
US4434218A (en) 1979-01-24 1984-02-28 Konishiroku Photo Industry Co., Ltd. Photosensitive composition for electrophotography

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FR1176922A (fr) 1959-04-17
BE541668A (fr)
GB837545A (en) 1960-06-15

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