Classifications

• • 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
  • G03G13/013—Electrographic processes using a charge pattern for multicoloured copies characterised by the developing step, e.g. the properties of the colour developers
  • G03G13/0131—Electrographic processes using a charge pattern for multicoloured copies characterised by the developing step, e.g. the properties of the colour developers developing using a step for liquid development, e.g. plural liquid color developers
• • 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
  • G03G5/09—Sensitisors or activators, e.g. dyestuffs
• • 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
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
  • G03G9/00—Developers
• • 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
• • 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
  • G03G9/09—Colouring agents for toner particles
• • 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
  • G03G9/09—Colouring agents for toner particles
  • G03G9/0906—Organic dyes
  • G03G9/0912—Indigoid; Diaryl and Triaryl methane; Oxyketone dyes
• • 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
  • G03G9/09—Colouring agents for toner particles
  • G03G9/0906—Organic dyes
  • G03G9/0914—Acridine; Azine; Oxazine; Thiazine-;(Xanthene-) dyes
• • 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
  • G03G9/09—Colouring agents for toner particles
  • G03G9/0906—Organic dyes
  • G03G9/0918—Phthalocyanine dyes
• • 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
  • G03G9/09—Colouring agents for toner particles
  • G03G9/0906—Organic dyes
  • G03G9/092—Quinacridones
• • 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

Definitions

• SENSITIZED DEVELOPERS FOR ELECTROPHOTOGRAPHY AND ELECTRORADIOGRAPHY This invention relates to sensitized developers for photoconductive surfaces for use in electrophotography and electroradiography.
• Dye-sensitization has the effect of causing better absorption of the light rays and activation of the photoconductor when exposed to an image.
• this dye sensitization is relatively effective except that the dye-sensitized paper has a colored appearance due to the greater sensitivity of the eye to certain colors, and therefore most dye-sensitized paper have a pinkish tinge to the human eye, a factor which for images where a white background is required is not desirable.
• the dye-sensitized papers are also subject to the disadvantage that when multicolor development is to be effected, the first color down will desensitize the photoconductor base due to the overlaying image deposit acting as a mask to prevent the photoconductor beneath from being correctly activated by light of the required color.
• the sensitizing dye may be first dissolved in a polar liquid and then incorporated with a resinous toner in a developer concentrate.
• the concentrate is then dispersed by grinding into the carrier liquid.
• An electrostatic image developed with such a dyed resinous toner dispersion if found to have a higher sensitivity to subsequent exposures to light than the nonimage areas.
• the successive developer deposits be not impaired by the underlying deposits, particularly as regards nonimage absorption of light.
• one colored developer can act as an unwanted filter for a second exposure involving a second colored developer.
• extra sensitization of the underlying photoconductor is achieved by incorporating the dye in the developer and hence in the area which is developed in the first step, after the first exposure. This means that the extra sensitization imparted by the developer causes the photoconductive sheet on second exposure to exhibit the same response to a given quantity of light irrespective of the density of the previous developed image.
• the characteristics of the cyan deposit are such that 60 percent of the blue light may be reflected from the sheet; thus for the subsequent exposure through a blue filter (required to print the yellow developer) 40 percent of the blue light is absorbed by the cyan developer deposit, thus areas of the sheet which have no developer will receive 40 percent more light than the areas which have cyan developer for equal intensity of light impinging on them. If the sensitivity to blue light of the sheet beneath the cyan developer deposit can be increased, this factor can be overcome, that is, both the developed and the undeveloped areas discharge on exposure to the same level, and uniform second development results.
• the sensitization of the photoconductive sheet to a given portion of the spectrum can also be arranged so that sensitization takes place in both the developed area and the undeveloped area. This is useful for the exposure and development of a continuous tone electrophotographic color pring from a color transparency using three color filters.
• Green filter for example Kodak Wratten No. 6
• Sensitization of the first kind that is localized imagewise sensitization, is achieved by confining the dye within the developer particles.
• Sensitization of the second kind is achieved by increasing the solubility of the dye in the carrier liquid, e.g. by adding solvents to the carrier liquid.
• One advantage of this technique is that color latitude of an electrophotgraphic sheet can be extended, enabling colored images to be reproduced correctly at both the lowand the highdensity ends of the scale, that is with very high densities unwanted filtration by the developer deposit obviously is disproportionate relative to the low densities.
• Another advantage is that white (unsensitized) photoconductive layers can be used for color printing if required.
• white dyes are added to enhance the apparent brightness of the developed images.
• the first developer contains a blue dye, sensitization for an image exposure through a red filter will result, and the next developer should then contain a red-sensitizing dye which sensitizes to green for the next exposure with a green filter and subsequent magenta developer.
• sensitizing dyes in each previous developer are not covered by the preceding development which would take place if the three colored dyes were included in the original surface, but deposition of the sensitizing dye is at a stage where it will remain effective over the required area.
• Dye sensitizing materials for zinc oxide are known, but the application by deposition with an image is the novel feature of this invention.
• a further advantage which results from the deposition of dye-sensitizing material just prior to exposure of the photoconductive medium is that as most of the materials have a certain acid value, deterioration of the dye-sensitizing agent is not effected as is the case where the paper is prepared long before it is actually used.
• EXAMPLE I An electrophotographic paper, film or plate is prepared by coating it with a layer of electrophotographic material of the following composition:
• the finish coating has a light buff color'and has a response giving approximately equal sensitivity for red, green and yellow light. 1.20
• a dye solution is made of the selected dye in methyl alcohol by weighing 1.0 gram of the dye and dissolving it in 100 milliliters of methyl alcohol. Typical dyes are listed in the following table:
• the dyes listed in the following table are typical of those used to sensitize photoconductive white zinc oxide binder coatings.
• a developer concentrate is prepared from the following materials:
• This concentrate is prepared by mixing the copolymercoated pigment with 100 grams of mineral turpentine and then adding the Solprene X40 copolymer and finally the remaining 400 grams of mineral turpentine.
• the dye solution of the above section 1.20 is then added to the developer concentrate in the proportions of 0.1 milliliter of dye solution to 100 grams of concentrate, the dye in this case being for example Rhodamine G. (Cl 45160 1.22
• the developer containing the dye is then dispersed in an iso-paraffinic carrier liquid such as the lsopar solvents of the Esso Company or Shellsol T of Shell Chemicals (Australia) Ltd., in the proportions of 1 gram of concentrate in 100 grams of carrier liquid to form a liquid developer.
• the electrophotographic sheet of section 1.1 of this example is then charged electrostatically by means of the corona discharge from points or wires held at a high potential in relation to the sheet, for example to give a field of 5 kv. per inch.
• the sheet is then exposed to a colored image through a selected filter for example orange filter (Kodak Wratten No. 29 and then developed with the above blue developer which contains in addition the red dye.
• the electrophotographic sheet of section 1.23 is then recharged electrostatically and reexposed to the colored image through a second filter for example green filter, (Kodak Wratten No. 61 and the sheet is then developed in a magenta developer.
• a second filter for example green filter, (Kodak Wratten No. 61 and the sheet is then developed in a magenta developer.
• magenta developer is prepared as in section 1.21 by substituting a magenta pigment is place of the lrgafin 81 blue, for example, Brillfast Geranium 3543 supplied by Smith Reichold Ltd.
• the response of the electrophotographic sheet under the blue-developed areas of section 1.23 is corrected by the presence of the red dye which sensitizes the photoconductor to green light to a degree depending on the density of the bluedeveloped image.
• the electrophotographic sheet of section 1.24 is then recharged electrostatically and reexposed to the colored image through a third filter for example a purple filter, Kodak Wratten 47B, and developed in yellow pigment.
• a third filter for example a purple filter, Kodak Wratten 47B, and developed in yellow pigment.
• the final result is an overprinted full-color representation.
• An electrophotographic paper, film or plate is prepared by coating it with a layer of electrophotographic material of the following composition:
• a dye-sensitized liquid developer is prepared for this example by dissolving the selected dye in alcohol and adding it to the developer material which follows in Section 2.21.
• the dye solution is made up in the proportions of 1.0 gram of the dye for example, Malachite green in 100 milliliters of methyl alcohol.
• a developer concentrate is prepared from the following materials:
• the developer concentrate containing the dye is then dispersed in a cyclo-paraffinic carrier liquid such as cyclohexane in the proportions of 1 gram of concentrate in 100 grams of carrier liquid developer.
• a cyclo-paraffinic carrier liquid such as cyclohexane
• the electrophotographic sheet of section 2.1 of this example is then charged electrostatically by means of the corona discharge from points or wires, for example in a field of kv. per inch.
• the sheet is then exposed to a colored image through a selected filter for example an orange filter, Kodak Wratten No. 29 and then developed with the developer of section 2.22 which contains in addition the green dye which sensitizes the sheet underlying the image to red light.
• the electrophotographic sheet of section 2.23 is then recharged electrostatically and then exposed to a colored image through a selected orange (red) filter for example Kodak Wratten N0. 29.
• the resultant electrostatic image is then developed in a cyan developer of the type described in section 2.21 in which a phthalocyanine blue pigment such as lrgafin S1 is substituted for the magenta pigment and which in addition a yellow dye which sensitizes to purple light, for example Fluorescein, CI No. CI 45350.
• the electrophotographic sheet of section 2.24 is then recharged electrostatically and then exposed to the colored image through a selected purple filter for example Kodak Wratten No. 47B.
• the resultant electrostatic image is then developed with a yellow developer, made by substituting a yellow pigment in the formulation of section 2.21, for example Microlith Yellow 26, a diazo pigment supplied by C.I.B.A., Switzerland.
• An electrophotographic paper, film or plate is prepared by coating the paper or the like with a layer of electrophotographic material of the following composition:
• a dye-sensitizing solution is made up as in section 1.20.
• a developer concentrate is prepared from the following materials:
• the developer containing the dye is then dispersed in an isoparaffinic carrier liquid such as the lsopar Solvent G of the Esso Company or Shellsol T of the Shell Chemicals (Australia) Co., in the proportions of 1 gram of concentrate in 100 grams of carrier liquid to form a developer.
• an isoparaffinic carrier liquid such as the lsopar Solvent G of the Esso Company or Shellsol T of the Shell Chemicals (Australia) Co.
• the electrophotographic sheet of section 3.1 of this example is then charged electrostatically and exposed to a colored image projected through a selected filter for example an orange (red) filter, for example Kodak Wratten No. 29.
• a selected filter for example an orange (red) filter, for example Kodak Wratten No. 29.
• the resultant electrostatic image is then developed in a cyan developer of the type described in section 3.21, containing the Eosin Cl No. 45380.
• the electrophotographic sheet of section 3.23 of this example is the recharged electrostatically and exposed to the colored image projected through a second filter for example a green filter such as Kodak Wratten No. 61.
• the resultant electrostatic image is then developed in a magenta developer of the type described in Section 3.21 in which Magenta pigments Isol Ruby Fast Red (60 percent) (Robert Bryce Pty. Ltd.), and Brillfast Fast Red (40 percent) (Reichold Chemical Corp. are substituted for the lrgafin S1, and which in addition contains a yellow dye to sensitize to purple light for example Fluorescein C1No.45350.
• the electrophotographic sheet of section 3.24 is then recharged electrostatically and then exposed to the colored image through a selected purple filter for example Kodak Wratten No. 47B.
• the resultant electrostatic image is then developed with a yellow developer, made by substituting a yellow pigment in the formulation of section 3.21 for example Fastona Yellow 30 3965 of Smith Reichold Ltd., an anilineanilide yellow pigment.
• the final result is an over-printed full-color representation.
• An electrophotographic paper, plate or film is prepared by coating its surface with a layer of material of similar composition to that of example 1, section 1.1, from which the dyes however are omitted.
• the resultant coating is white in apthe dyes are omitted.
• the developers of this example are the developers of section 2.2] for example to which are added dyes in alcohol and alkyd resin solution as described in Section 4.20.
• Example 4 is characterized by higher intrinsic sensitivity to EXAMPLE 6. blue light than red or green.
• the materials of Example 4 are modified by substituting for 4.20
• adye the alkyd resin 470 one or more of the following resins to solution is made of the selected dye in this case Erioglaucine disperse the dye:
• Oil length, Acid Trade name and type Oil typc percent value Diluonl. Supplivr Rhodene L42/70 Penta ostcrilied. SflfikflVtY. 64 6-10 Whito. spirit. Polymer (ol'imrution (Aust.).
• Example 4 is modified by substituting for dye dye solution is then dissolved in along oil alkyd resin, such the alkyd resin 470P one or more of the following vegetable as P470, a soya modified penta alkyd resin of 65 oil length, oils to dissolve and disperse the dye: product of Polymer Corporation (Australia) Ltd., in the proportions 1 part by volume of alcohol dye solution to 10 parts f resin.
• Oil Acid No. the alkyd resin 470P one or more of the following vegetable as P470, a soya modified penta alkyd resin of 65 oil length, oils to dissolve and disperse the dye: product of Polymer Corporation (Australia) Ltd.
• a developer concentrate is prepared from similar materi- Z222 ,11 3] gfzs ffg ff 81336 :33: als to those of example 1, section 1.21, modified m that a yelochydiaied astor on max. 5.0 Meggitt's Ltd.
• Aim low pigment such as Microlith Yellow 2GT, of C.l.B.A., is sub- Oiticiva "Wick U4 stituted for the lrgafin Sl blue, and to this developer conceni? Cotton seed oil Meggitt 5 Ltd. Ausl.
• the electrophotographic sheet of section 4.1 of this eximages which comprises dye-sensitizing during each sequenample is charged electrostatically and then exposed to a tial step to correct the image surface at each stage for the next colored im g through a bl fil for x mp Kodak W color exposure which requires correction, said dye-sensitizaten N0. 478, and then developed t the ab yellow 40 tion being effected byadding to or applying together with a developer which in addition contains blue dye.
• the blue dye li uid d elo er in an imagewise manner, a nonphotoconducsensitizes the imaged areas and also t e no image areas o red tive dye-sensitizing medium for the color of the next exposure light, for example the blue dye Erioglaucine blue, dispersed in to compensate for the pressure of the deposited developer the fesmshielding ofthe photoconductive surface, whereby at least one
• the electrophotographic Sheet 0f Section is of the developers, other than that last applied, is arranged to recharged electrostatically and reexposed to the colored apply a sitizing dye imagewise to th ar where cor.
• the electrophotographic sheet of section 4.24 is then i the following steps; effecting a first exposure through a recharged electrostatically and reexposed 0 the Colore filter to expose one of said colors, developing the thus formed image through a third filter.
• a third filter for example gre n filt r K dak latent electrostatic image by means of liquid developer of Wratten NO.
• the latent electrostatic image 50 produced is complementary color containing a correcting dye for the developed with a magenta developer prepared as in section Second exposure, ff i h id second image exposure 1,21 by substituting a magenta pigment such as Brillfast" through a filter of the required color, developing same with a Geranium 3543 red for the lrgafin Sl blue.
• the final result is complementary liquid developer containing a correcting dye an overprinted full-color continuous tone representation. for the next exposure, effecting a further exposure for the EXAMPLE 5. remaining color, and developing same with a liquid developer in this example the electrophotographic sheet is coated with f m lementa l r, the photoconductive material of section 2.1 differing in that

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• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Color Electrophotography (AREA)
• Photoreceptors In Electrophotography (AREA)
• Liquid Developers In Electrophotography (AREA)

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• 1967
  • 1967-09-18 AU AU27289/67A patent/AU420588B2/en not_active Expired
• 1968
  • 1968-09-17 GB GB1238054D patent/GB1238054A/en not_active Expired
  • 1968-09-18 FR FR1586227D patent/FR1586227A/fr not_active Expired
  • 1968-09-18 NL NL6813362A patent/NL6813362A/xx not_active Application Discontinuation
  • 1968-09-18 US US760733A patent/US3620722A/en not_active Expired - Lifetime
  • 1968-09-18 DE DE1797353A patent/DE1797353C2/de not_active Expired
  • 1968-09-18 BE BE721049D patent/BE721049A/xx unknown

Patent Citations (2)

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