Classifications

• • 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
  • G03G5/0202—Dielectric layers for electrography
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
  • G03G13/00—Electrographic processes using a charge pattern
  • G03G13/01—Electrographic processes using a charge pattern for multicoloured copies
• • 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
  • G03G5/10—Bases for charge-receiving or other layers
• • 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
  • G03G5/12—Recording members for multicolour processes

Definitions

• the present invention relates to improved methods for forming a colored copied image through the process of transferring an electrostatic latent image.
• an electrostatic transferring method for forming a colored copied image on a transfer sheet consisting of a support and a dielectric layer of insulating resin by repeating a cycle consisting of forming an electrostatic latent image on a copying material through electrification of said copying material and exposure of a colored original image upon color separation thereof into three primary colors, transferring the thus formed electrostatic latent image onto a transfer sheet having a dielectric layer of insulating resin and developing the transferred latent image.
• the former method is defective in that, in that it is necessary to form a temporary toner image on an electrophotographic copying paper and then transfer the image onto a transfer sheet, the electrophotographic copying material may be damaged.
• the latter method has the merit that, since an electrostatic latent image formed on an electrophotographic copying material is transferred onto a transfer sheet electrically without developing the latent image, the copying material is less likely to become damaged.
• some of the electric charge from the electrostatic latent image transferred onto the transfer sheet remains even after development, This causes the developer to attach to the part having the residual electric charge during the second cycle and the following cycles, giving rise to the phenomenon called fog which makes the reproduction of faithful colored images difficult.
• the present invention provides methods of producing colored copied images through the electrostatic latent image transferring process, in which there is rapid extinction of the residual electric charge and the production of colored images free of fog.
• the present invention provides methods of forming colored copied images characterized in that, the transfer sheet contains a photoconductive substance in the dielectric layer thereof and that there is an additional process step of applying active radiant rays to the whole surface of said dielectric layer which is interposed between the cycles.
• the transfer sheet for use in the present invention is composed by providing a dielectric layer containing an inorganic or organic photoconductive substance on a used.
• a dielectric layer containing an inorganic or organic photoconductive substance include, for example, acrylic resins, vinyl chloride vinyl acetate copolymers, butadiene styrene copolymers, alkyl-(metha)acrylate styrene copolymers, alkyl(metha)acrylate butadiene copolymers, silicone resins, alkyd resins and the like.
• Suitable inorganic photoconductive pigments for use in this invention include white-colored or light-colored zinc oxide, titanium oxide, etc.
• Suitable organic photoconductive pigments for use in this invention include colorless or light-colored pigments such as anthracene, oxadiazole, thiadiazole, aminothiazole, triazole, oxazole, thiazole, quinazoline, acridine and the like.
• Sensitizers which may be employed include, any of the sensitizers conventionally employed in the field, but it is essential that these sensitizers possess spectrosensitivity in each sphere of blue, green and red, that is 400-500 um, 500-600 mp. and 600-700 ma.
• sensitizers there are Crystal Violet, Malachite Green, Methyl Violet, Acridine Yellow, Bromophenol Blue, Erythrosine, Rose Bengale, Thymol Blue and 2,4,7-trinitrofluorenone. These sensitizers are utilized in amounts of 5X10 mole to 5X10 mole for each g of photoconductive substance employed.
• the transfer sheet for use in electrostatic transferring of the present invention in the case of employing an inorganic or organic photoconductive pigment for the dielectric layer thereof, it is essential to select an appropriate mixing ratio of the insulating resin and the photoconductive pigment, and it is appropriate to mix the photoconductive pigment at a rate of0.35 parts by weight and preferably 0.5 2.5 parts by weight for each part by weight of the insulating resin.
• the amount of the photoconductive pigment is less than 0.3 part by weight, there is not a sufficient extinction of the residual electric charge even when the whole surface of the dielectric layer is exposed to light, while in the case where said amount is in excess of 5 parts by weight, the surface texture of the dielectric layer becomes coarse, causing not only the lowering of the transfer efficiency of electrostatic charge [l-(surface potential on copying material after transferring)/(surface potential on copying material before transferring)] but also the loss of the paperlike feeling when the support is paper, so that both cases are undesirable.
• modifying agents as starch, silica, polyethylene particles and the like may be added.
• an organic photoconductive resin which is concurrently an insulating resin
• an inorganic white pigment such as silica, zinc oxide, titanium oxide, etc.
• addition of a sensitizer is preferable.
• organic photoconductive resins have insulating properties, it is not necessary to employ additional insulating resins with them.
• useful organic photoconductive resins include for instance, poly-N-vinylcarbazole or its halogenated derivatives, polyvinylanthracene or its derivatives and the like.
• the appropriate weight ratio of the inorganic white pigment to the organic photoconductive resin is in the range of 0. l5 and preferably 0.3-3. In the case where this weight ratio is less than 0.1, the paperlike feeling is lost, while if it is in excess of 5, the transfer efficiency is lowered. Both cases are undesirable.
• the thickness of the dielectric layer in the present invention can be varied within the range of l30 ,u, and a satisfactory thicknessis in therange of 5-15 t.
• An electrophotographic copying material prepared by providing a photoconductive layer on a support is charged with electricity by corona discharge, and then an electrostatic latent image is formed on said copying material by applying white light from tungsten lamp reflected from or passed through a colored original image through a red filter (color separation of the colored original image is effected through this process).
• the electrostatic latent image is transferred onto the dielectric layer of the transfer sheet, and then the electrostatic latent image thus transferred onto the dielectric layer is developed with a developer containing cyan-color toner particles and fixed.
• resulting dispersion was coated on a paper support treated for imparting conductivity by the use of a wire bar to the extent of about 10 p. in dry thickness, and dried thereafter, whereby a transfer sheet was prepared.
• the electrostatic latent image transferred onto the transfer sheet was subjected to cascadesystem development by the use of an electrophotographic dry developer consisting of a mixture of cyancolor toner particles and glass particles having a mean particle diameter of 10 t, followed by thermal fixing. Thereafter, by exposing the whole surface of the transfer sheet to white light of a tungsten lamp having a luminous intensity of 5,000 luxes/sec., the residual electric charge was extinguished.
• an electrostatic latent image formed by impressing electricity on the foregoing electrophotographic copying material and exposing it to rays reflected from the colored original image through a blue filter was transferred onto the dielectric layer of the foregoing transfer sheet to see that the positions of images agree with each other, developed with a developer consisting of yellow-color toner particles and glass particles and subjected to thermal fixing. Thereafter, by exposing the whole surface of the transfer sheet to white light of a tungsten lamp having a luminous intensity of 5,000 luxes/sec, the residual electric charge was extinguished.
• chlorobcnzcnc solution of polyvinyl carbazolc llllt. oxide chlorobenzcne 500 parts by weight 10 parts by weight 300 parts by weight
• a mixture having the above composition was dispersed for 20 minutes by means of a homomixer.
• the resulting dispersion was coated on a paper treated for imparting conductivity to the extent of about 8 p. in dry thickness, whereby a transfer sheet was prepared.
• the developers employed in the present example were prepared through the following procedures:
• composition of cyan-color liquid developer
• a method of forming a colored copied image on a transfer sheet by repeating a cycle comprising (1) forming an electrostatic latent image on an electrophotographic copying material having a photoconductive layer, (2) transferring said electrostatic latent image onto a transfer sheet having a dielectric layer which is an insulating resin and (3) developing the thus transferred electrostatic latent image for each primary color constituting the colored original image; the improvement comprising employing a transfer sheet having a photoconductive dielectric layer upon which the image is developed and applying active radiant rays to the whole surface of said dielectric layer between successive cycles to dissipate residual charge from a previous cycle.
• said dielectric layer comprises an inorganic photoconductive pigment in an insulating resin.
• a method according to claim 2, wherein the amount of said inorganic photoconductive pigment is in the range of 0.3-5 parts by weight relative to 1 part by weight of said insulating resin.
• said dielectric layer comprises an organic photoconductive pigment in an insulating resin.

Landscapes

• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Photoreceptors In Electrophotography (AREA)
• Color Electrophotography (AREA)
• Developing Agents For Electrophotography (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=11678141

Family Applications (1)

Country Status (3)

Cited By (6)

Citations (1)

• 1973
  • 1973-01-19 JP JP788973A patent/JPS549891B2/ja not_active Expired
  • 1973-12-28 US US429146A patent/US3871879A/en not_active Expired - Lifetime
• 1974
  • 1974-01-08 GB GB76474A patent/GB1455312A/en not_active Expired

Patent Citations (1)

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