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
  • G03G5/04—Photoconductive layers; Charge-generation layers or charge-transporting layers; Additives therefor; Binders therefor
  • G03G5/06—Photoconductive layers; Charge-generation layers or charge-transporting layers; Additives therefor; Binders therefor characterised by the photoconductive material being organic
  • G03G5/0622—Heterocyclic compounds
  • G03G5/0644—Heterocyclic compounds containing two or more hetero rings
  • G03G5/0646—Heterocyclic compounds containing two or more hetero rings in the same ring system
  • G03G5/0653—Heterocyclic compounds containing two or more hetero rings in the same ring system containing five relevant rings

Definitions

• inorganic pigment-binder type plates are that latent electrostatic image may be formed on the plate by they can be charged only by negative and not by positive charging said plate in image configuration.
• This image is corona discharge. This property makes them commercially rendered visible by depositing onthe imaged layer a finely undesirable since negative corona discharge generates divided developing material comprising a colorant called much moreozone than positive corona discharge and is a toner and a toner carrier.
• the powdered developing magenerally more difficult to control.
• photoconductive insulating ing materials such as anthracene, sulfur, selenium or mixlayers have thermal distortion properties which make them vtures thereof havebeen disclosed by Carlson in US. Pat. undesirable in an automatic electrophotographic appara- 2,297,691.
• These materials generally have sensitivity in tus which often includes powerful lamps and thermal fusthe blue or near ultraviolet, range, and all but selenium ing devices which tend to heat the electrophotographic have a further limitation of being only slightly light-sensiplate.
• photoconductive layers are superior to many heretofore SUMMARY OF THE INVENTION known binder suspensions of inorganic pigments which require a relatively high percentage of inorganic pigment It is, therefore, an ob ect of this invention to provide such that the inorganic pigment used i ll cqntmls an electfophotogfaphlc Plate devold of the above'noted the physical properties of the final photoconductive layer.
• the photoconductive plate may have a Photographic Plates having Sensitivties which extend over very hard, very smooth surface. This eliminates many of Substantial Portions of the Visible P the disadvantages of the prior pigment-binder plates which, Still another object Of this invention is 1:0 provide a 1' 6- because f the proportions of igment had a very usable electrophotographic plate having a high overall rough d abrasive f Sensitivity and high thermal Stability When compared to While any of the novel class of quinacridones having Present commercially available reusable p the above-described general formula may be used to pre- Yet aflflthaf Object of this invention is to Provide pare the photo-conductive layer of the present invention, photoconductive insulating material suitable for use in ⁇ Us preffirred to employ those i id h i R electrophotographic plates in both single use and reusable
• Yet another further object of this invention is to provide since these materials are highly photosensitive and proan electrophotographic plate having a wide range of useful prise the most desirable images. physical properties.
• Various of the above-described novel quinacridones are accomplish d in may be utilized alone or in combination with other comaccordance with this invention, generally speaking, by positions in any suitable mixture, dimer, trimer, oligomer, providing an electrophotographic plate having a novel polymer, copolymer or mixtures thereof.
• the novel class of quinacridones of the persent invenin a resin binder, said quinacridone pigment having the foltion are prepared by a method which comprises mixing a lowing general formula: compound having the .general formula:
• the resin used in the present invention should be tive layer may be deposited on any suitable supporting submore resistive than about 10 and preferably more than strate, or may be cast as a self-supporting film.
• the plate 10 ohms per centimeter under the conditions of electro may be overcoated with any suitable materials, if desired. photographic use.
• Typical resins include: thermoplastics
• the quinacridone-resin photoconductive layer may be including olefin polymers such as polyethylene and polyused in the formation of multi-layer sandwich configurapropylene; polymers derived from dienes such as polytions adjacent a dielectric layer, similar to that shown butyldiene, polyisobutylene, and polychloroprene; vinyl by Golovin et al., in the publication entitled A New and vinylidene polymers such as polystyrene, styrene- Electrophotographic Process, Elfected by Means of Comacrylonitrile copolyrners, acryloru'trile butadiene-styrene bined Electric Layers Doklady. Akad.
• thermosetting resins including phenolic resins;
• cal properties of the final photoconductive layer may be amino resins such as urea-formaldehyde resins and melamineformaldehyde resins; unsaturated polyester resins; epoxy resins, silicone polymers; alkyd resins and furan resins.
• amino resins such as urea-formaldehyde resins and melamineformaldehyde resins
• unsaturated polyester resins such as epoxy resins, silicone polymers; alkyd resins and furan resins.
• epoxy resins, silicone polymers such as epoxy resins, silicone polymers
• alkyd resins and furan resins such as urea-formaldehyde resins and melamineformaldehyde resins
• unsaturated polyester resins such as epoxy resins, silicone polymers; alkyd resins and furan resins.
• epoxy resins such as epoxy resins, silicone polymers
• alkyd resins and furan resins such as urea-formaldehyde resins and
• the quinacridone compositions of the present invention may be incorporated into the dissolved or melted binderresin by any suitable means such as strong shear agitation, preferably with simultaneous grinding. Typical methods include ball milling, roller milling, sand milling, ultrasonic agitation, high speed blending and any combination of these methods. Any suitable ratio of pigment to resin may be used. On a quinacridone-dry resin weight basis, the useful range extends from about 1:1 to about 1:40. ⁇ Best results are obtained at, and therefore the preferred range is, from about 1:4 to about 1:10. Optimum results are obtained when the ratio is about 1:4. While highest photosensitivity is obtained at pigment-resin ratios of 1:1 to 1:4, at the high concentration of pigment dark conductivity increases.
• Suitable materials'for this purpose include aluminum, steel, brass, metallized or tin oxide coated glass, semiconductive plastics and resins, paper and any other convenient material of bulk resistivity at the time of use v ohms-cm., or surface resistivity -10 ohms/square.
• the pigment-resin-solvent slurry (or the pigment-resin-melt) may be applied to conductive substrates by any of the wellknown painting or coating methods, including spraying, flow-coating, knife coating, electro-coating, Mayer bar drawdown, dip coating, reverse roll coating, etc.
• Spraying in an electric field may be preferred for smoothest finish and dip coating may be preferred for convenience in the laboratory.
• the setting, drying, and/ or curing steps for these plates are generally similar to those recommended for films of the particular binders'as usedfor other'painting applications.
• quinacridoneepoxy plates may be cured by adding a cross-linking and stoving according to approximately about the same schedule as other baking enamels made with the. same resins photoconductive coating and preferably should beno more than 4/; the thickness of said coating.
• Any suitable overcoating, as for example, nitrocellulose lacquer, may be employed.
• EXAMPLE 1 An electrophotographic plate is prepared by initially mixing about 6 parts Pliolite 85B, a styrene-butadiene copolymer resin available from Goodyear Tire and Rubber Company, about 43 parts xylene and about 1 part of a quinacridone pigmenthaving the formula:
• quinacridone compositions are stable against chemical decomposition at the temperature normally used for a wide variety of bake-on enamels, and therefore, may be incorporated in very hard glossy photoconductive coatings, having surfaces similar to automotive or kitchen appliance resin enamels.
• the thickness of the quinacridone-binder films may be varied from about 1 to about 100 microns, depending upon the required characteristics.
• Self-supporting films for example, cannot be conveniently manufactured in thickdispersion is applied to a sheet of 5 mil aluminum foil using a No. 36 wire draw-down rod. The coating is then forced air dried at about C. for about two hours.
• the charged plate is then contact exposed for 15 seconds to a film positive by means of a tungsten lamp-having a 3400 K. color temperature.
• the illumination level at the exposure plane is about 57 foot candles.
• the latent electrostatic image formed on the plate is then developed by cascading pigmentedelectroscopic marking particles over the plate, by the process described, for example, in US. Patent 2,618,- 551.
• the powder image developed on the plate is electrostatically transferred to a receiving sheet and heat fused thereon.
• the image on the receiving sheet is of good quality and corresponds to the contact exposed original.
• This plate is positively charged to an initial potential of about 290 volts.
• the image resulting is of satisfactory quality. 7
• EXAMPLES III-1V Two electrophotographic plates are prepared by mixing about 1 part Vinylite VYNS, a copolymer of vinyl chloride and vinyl acetate available from Union Carbide Corporation, about 10 parts diethyl ketone and about 1 part of a quinacridone pigment having the formula:
• the plate is coated, cured, charged, exposed and developed as in Example I above, however, in Example III, the plate is positively charged to a potential of 480 volts and, in Example IV, the plate is charged to a negative potential of 835 volts.
• the resulting image is of excellent quality.
• An electrophotographic plate is prepared by initially mixing about 1 part Vinylite VYNS, about 10 parts diethyl ketone, and about 1 part of a quinacridone pigment having the formula:
• the plate is coated, cured, charged and developed as in Example 1 above. However, here the plate of Example VII is charged to a positive potential of 410 volts and the plate of Example VIII is chraged to a negative potential of 605 volts. Excellent images are produced by these plates.
• EXAMPLES IX-X Two electrophotographic plates are prepared by initially mixing about parts of a 10 percent solution of polyvinyl carbazole in benzene, about 5 parts cyclohexanone, and about 1 part of the quinacridone pigment of Example I. These plates are coated, cured, charged, exposed and developed as in Example -1 above. However, here the plate of Example ]X is charged to a positive potential of about 180 volts and the plate of Example X is charged to a negative potential of about 215 volts. Images of good quality are produced.
• Electrophotogranhic plates are prepared by initially mixing about 100 parts of a 10 peroentpolyviuyl carbazole solution in benzene, about 5 parts cyclohexanone and about 1 part of the quinacridone pigment of Example II. The plates are coated, cured, charged, exposed and developed as in Example I above. However, here the plate of Example XI is charged to a positive potential of about volts and the plate of Example XII is charged to a negative potential of about volts. Images of good quality result. 7 I
• the pigment compositions and/or the pigment-resin compositions of this invention may be dyesensitized, if desired, or may be mixed or otherwise combined with other photoconductors, both organic and inorganic.
• An electrophotographic imaging process which comprises uniformly charging the surface of an electrophotographic plate comprising a self-supporting layer of an electrophotographic composition comprising a photoconductive quinacridone pigment in a binder material, said quinacridone pigment having the formula:
• R is selected from at least one member of the group consisting of CH C H OCH OC H and a halogen and wherein R is selected from at least one member of the group consisting of an aromatic group, a heterocyclic group, an alicyclic group and an aliphatic group, said layer having a thickness greater than about microns, and exposing said charged plate to a pattern of activating electromagnetic radiation to produce an electrostatic latent image.
• An electrophotographic imaging process which comprises uniformly charging the surface of an electrophotographic plate comprising a support substrate having a bulk resistivity greater than about 10+ ohms-centimeter having superimposed thereon a photoconductive layer 0 ll H E wherein R is selected from at least one member of the group consisting of CH, C H OCH, OC H and a halogen and wherein R is selected from one member of the group consisting of an aromatic group, a heterocyclic group, an alicyclic group and an aliphatic group, and selectively exposing said charged plate to activating electromagnetic radiation to produce an electrostatic latent image.

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• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Photoreceptors In Electrophotography (AREA)

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Cited By (4)

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• 1968
  • 1968-08-22 US US754726A patent/US3667943A/en not_active Expired - Lifetime
• 1969
  • 1969-06-20 BR BR209996/69A patent/BR6909996D0/pt unknown
  • 1969-08-20 GB GB41586/69A patent/GB1278702A/en not_active Expired
  • 1969-08-21 FR FR6928700A patent/FR2016183A1/fr not_active Withdrawn
  • 1969-08-21 BE BE737810D patent/BE737810A/xx unknown
  • 1969-08-21 PL PL1969135479A patent/PL80390B1/pl unknown
  • 1969-08-21 NL NL6912733A patent/NL6912733A/xx unknown
  • 1969-08-21 CH CH1269269A patent/CH519183A/de not_active IP Right Cessation
  • 1969-08-21 DE DE19691942700 patent/DE1942700A1/de active Pending
  • 1969-08-21 ES ES370720A patent/ES370720A1/es not_active Expired

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