US3681067A - Cds-chalcogen ternary compound mixture as photoconductive material in an electrophotographic member - Google Patents

Cds-chalcogen ternary compound mixture as photoconductive material in an electrophotographic member Download PDF

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Publication number
US3681067A
US3681067A US61548A US3681067DA US3681067A US 3681067 A US3681067 A US 3681067A US 61548 A US61548 A US 61548A US 3681067D A US3681067D A US 3681067DA US 3681067 A US3681067 A US 3681067A
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Prior art keywords
chalcogen
layer
photosensitive
cds
photosensitive member
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US61548A
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Hiroshi Hanada
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Canon Inc
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Canon Inc
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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
    • G03G5/08—Photoconductive layers; Charge-generation layers or charge-transporting layers; Additives therefor; Binders therefor characterised by the photoconductive material being inorganic
    • G03G5/082—Photoconductive layers; Charge-generation layers or charge-transporting layers; Additives therefor; Binders therefor characterised by the photoconductive material being inorganic and not being incorporated in a bonding material, e.g. vacuum deposited
    • 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
    • G03G5/043—Photoconductive layers characterised by having two or more layers or characterised by their composite structure
    • G03G5/0433—Photoconductive layers characterised by having two or more layers or characterised by their composite structure all layers being inorganic
    • 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
    • G03G5/08—Photoconductive layers; Charge-generation layers or charge-transporting layers; Additives therefor; Binders therefor characterised by the photoconductive material being inorganic
    • G03G5/087—Photoconductive layers; Charge-generation layers or charge-transporting layers; Additives therefor; Binders therefor characterised by the photoconductive material being inorganic and being incorporated in an organic bonding material

Definitions

  • An electrophotographic photosensitive member which comprises a photoconductive layer comprising CdS and a chalcogen ternary compound of the formula X,YZ
  • X is Zn or Cd
  • Y is Si or Ge and Z is S, Se or Te.
  • This invention relates to an electrophotographic photosensitive member having a suflicient sensitivity over the entire visible light region and more particularly to an electrophotographic photosensitive member useful for duplicating colored originals.
  • zinc chalcogen binary compounds and zinc oxide have been investigated which have sensitivity to a short Wavelength region.
  • the zinc chalcogen binary compounds have a very low sensitivity and zinc oxide is accompanied by fatigue effect, neither of them is suitable for sensitivity compensa tion of cadmium chalcogen binary compounds.
  • This compound has inherently such wide sensitivity region without incorporating any activating agent thereto.
  • Representative ternary compounds having the above formula are Cd SiS Cd SiSe Cd SiTe Cd GeS Cd GeSe Cd GeTe ZH4SIS5, Zn SiSe Zn SiTe Zn GeS Zn GeSe and Zn, GeTe
  • these compounds have hitherto been used 3,681,067 Patented Aug. 1, 1972 only in a single crystal form or in a sintered form for producing photocells, and no attempt has been made to use them as materials for electrophotography in a vapor deposited film form or powder form.
  • the photosensitive layer contains a photosensitive chalcogen ternary compound composed of cadmium or zinc, silicon or germanium, and chalcogen element, solid solution thereof, a cadmium chalcogen binary compound, or solid solution thereof which has been given a sufiicient resistance by the above-mention treatments.
  • a further feature of this invention resides in that the photosensitive member is obtained by laminating a layer containing a chalcogen ternary compound composed of cadmium or zinc, silicon or germanium, and chalcogen element or solid solution thereof with a layer containing a cadmium chalcogen compound or solid solution thereof, and these ternary and binary compounds having been given a sufiicient resistance by the above-mentioned treatments.
  • this invention relates to an electrophotographic photosensitive member characterized by having a photosensitive layer containing substances (I) and (II) as mentioned below, or laminating on a base two photosensitive layers each of which contains at least one of the substances (1) and (II) as mentioned below.
  • At least one kind of photosensitive chalogen ternary compounds of the formula X YZ where X denotes a member selected from the group consisting of Zn and Cd, Y a member selected from the group consisting of Si and Ge, and Z a member selected from the group consisting of S, Se and Te, or their solid solutions.
  • An object of this invention is to provide an electrophotographic photosensitive member having a sufliciently high sensitivity over the entire visible ray region.
  • Another object of this invention is to provide an electrophotographic photosensitive member which is particularly useful for color duplication.
  • a further object of this invention is to provide a method for imparting to conventional chalcogen ternary compounds a resistance suflicient to enable them to be used as materials for electrophotography by applying appropriate heat treatmente or chemical treatment to them.
  • FIG. 1 is an enlarged cross sectional view of a photo sensitive member embodying this invention
  • FIG. 2 is a graph showing a relation between wavelength and relative photoconductivity of a photosensitive member embodying this invention.
  • FIG. 3 is a graph showing a relation between wavelength and relative photoconductivity of a photosensitive member containing cadmium sulfide.
  • a photosensitive member having preferable characteristics can be obtained in a case where two photosensitive layers containing the above-mentioned substances (I) and (II), respectively, are laminated on a base by laying, as a lower layer, a layer sensitive to long wavelength side, that is, layer 2 (in FIG. 1) containing cadmium chalcogen binary compounds, in close contact with the base plate 1 (in FIG. 1), and laying as the upper layer a layer sensitive to short wavelength side, that is, layer 3 (in FIG. 1) containing chalcogen ternary compounds.
  • the thickness of each layer is not limited, it is preferable to select the thickness of the lower layer, which is made to make a close contact with the base, however 1 and 15011., preferably between 30 and 70 and that of the upper layer laid on the surface of the lower layer between 1 and 50 preferably between 1 and 1014.
  • a layer having a thickness of less than 1,11. is hard to manufacture and, when the thickness of the upper layer exceeds 50a, the rays are scattered before reaching the lower layer, and, as a result, unfavorable effect is caused. Moreover, since the sensitivity of photosensitive layer is reduced when it is too thick, the thickness of both upper and lower layer is limited of its own accord.
  • the method for heat treatment or chemical treatment of chalcogen ternary compounds of this invention is as follows.
  • the powder, 5 microns or more in grain diameter, of photoconductive chalcogen ternary compounds, obtained by mixing and fusing chalcogen ternary compounds, impurity, and flux is ground to fine powders, annealed at temperatures equal to the above-mentioned mix ing and fusing temperature or less for a long period of time to restore the photoconductivity and to obtain a sufficient resistance to be used as material for electrophotography.
  • the chalcogen ternary compounds suitable for use in this invention may be synthesized directly by using the undermentionedsynthetic method.
  • a mixture containing one or more of Cd or Zn chalcogenides and one or more simple substance of Ge or Si, or Ge or Si chalcogenide is combined in a ratio necessary to form chalcogen temary compounds such as Cd SiS Zn GeS etc. and the mixture is subjected to hydrothermal synthesis under a high vapor pressure.
  • the temperature ranges from 280 to 400 (3., the pressure ranges from to 200 kg./cm. and the processing time ranges from 5 to 30 hours.
  • the preferable conditions are temperatures lying within the range of 310 to 360 C., pressures within the range of to kg./cm. and processing time of 10 to 20 hours.
  • synthesis yield is increased when an adequate amount of chalcogen element is combined as a supplement material.
  • Addition of activators such as Cu salts, Ag salts, and halogens can extend the sensitive wavelength region or increase its sensitivity.
  • halide such as cadmium chloride and the like
  • the above-mentioned photoconductive ternary compound is heat-synthesized in the form of a disintegrable block body.
  • the calcination is desired to be performed in a stream of inert gas such as nitrogen gas, if possible.
  • this block body can be ground into photoconductive powder without any further treatment, if the block body is thrown into a deionized water, it crushes itself to be photoconductive powder having a grain diameter or approximately 10; and, at the same time, it is possible to remove the water soluble substances contained in the powder.
  • PREPARATION EXAMPLE 1 5776 parts of CdS powder, 281 parts of Si powder, and 640 parts of S and 50000 parts of distilled water were mlxed and introduced into a high-purity aluminum Tammann tube, and then the tube was placed in a stainless steel autoclave.
  • the autoclave was heated to a temperature of about 350 C., maintained at the temperature for about 15 hours, and then cooled. After cooled, the content of the Tammann tube was taken out, decanted, washed several times with pure water and dried to produce fine powders of a photoconductive ternary compound, Cd SiS having an averaged particle size of about 0.5,u.
  • PREPARATION EXAMPLE 2 Hydrogen sulfide gas was introduced into an aqueous strong hydrochloric acid solution obtained by dissolving GeO powder with HCl powder to precipitate white GeS The resulting precipitate was sufiiciently washed by decantation, filtered and dried.
  • the GeS thus obtained (1366 parts) and 'CdS powder (5776 parts) were mixed with a flux, that is, 714 parts of CdCl and 71 parts of NH4C1, and further 2 parts of CuCl was added thereto as an activator.
  • the mixture thus obtained was furthetr mixed with 2500 parts deionized water followedby-sufiicient kneading and drying.
  • the resulting dried blocks were ground to a desired particle size, placed in a quartz tube, and calcinated in a nitrogen gas stream at about 600 C. for 30 minutes.
  • the product thus calcinated was put in a deionized water and spontaneously crushed to fine powders of about lO in size.
  • the fine powders were repeatedly subjected to decantation and washing and then washed followed by drying.
  • the resulting dry powders were placed in a quartz tube together with sulfur powder and calcinated in a nitrogen gas stream at about 500 C. for 15 minutes, and then excessive sulfur .vapor was evacuated by a rotary pump and the .content was cooled to give photoconductive powders suitable for electrophotographic materials.
  • the chalcogen ternary compounds are bound with a resin to form a layer.
  • the chalcogen binary compounds are also bound with a resin to form a layer.
  • a photosensitive member comprising a photosensitive layer according to this invention and an insulating layer provided on the surface of the photosensitive layer can give visible images of high contrast particularly by an electrophotographic method comprising applying a primary electric charge to the insulating layer on the photosensitive layer by corona discharging or electrode charging, applying a secondary electric charge having a polarity opposite to that of the primary charge or AC discharging, contemporaneously imagewise exposing to a radiant energy, if desired, applying a whole surface irradiation to form electrostatic latent images on the' insulating layer surface and developing by a Wet or dry developing method.
  • binding resins used in this invention there may be used those generally known as binding resins for electrophotography, for example, thermosetting resins such as epoxy resins, phenol resins, and unsaturated polyester resins, and thermoplastic resins such as polyvinyl chloride, polyvinylacetate, cellulose acetate, nitrocellulose, methacrylic resins, polyvinyl alcohol, polyvinyl butyral, and copolymer of vinyl chloride and vinyl acetate.
  • thermosetting resins such as epoxy resins, phenol resins, and unsaturated polyester resins
  • thermoplastic resins such as polyvinyl chloride, polyvinylacetate, cellulose acetate, nitrocellulose, methacrylic resins, polyvinyl alcohol, polyvinyl butyral, and copolymer of vinyl chloride and vinyl acetate.
  • such substances as polyester, polycarbonate, polyacetate, polystyrene, polyfiuoroethylene, polyethylene, polypropylene, polyvinyl chloride, polyvinylidene chloride, polyurethane, epoxy resin, and melamine resin may be coated on the photosensitive layer or pasted in a film form to the photosensitive layer to form an insulating layer.
  • the insulating layer so'made must possess insulating property, mechanical strength, elasticity, and transparency sufficient to meet the requirements. What is particularly important is that the insulating layer must be excellent in electrostatic charge holding property.
  • the photosensitive member of this invention is not limited to have a photosensitive layer comprising two layers, that is, the upper layer and lower layer, but may have multilayer more than two layers by laying several additional layers. It is also possible to laminate, besides those mentioned above, other semiconductor layer, fluorescent layer, and the like.
  • the support of the photosensitive member used in this invention there may be used metal plates such as aluminum, copper, and zinc sheets, paper specially treated to prevent the solvent from permeating to the inside, plastic subjected to a conductive treatment, which are generally known as the support of photosensitive member for electrophotography.
  • the pasty mixture containing the photosensitive substance of (1) above was spread uniformly over an aluminum foil using an appropriate spacer and an appropriate blade in such a way that the thickness of the coat Was about 40 after dry.
  • the aluminum foil was left to stand for several hours to dry and then was heated to dry for 2 hours at 60 C.
  • a coat of pasty mixture containing the photosensitive substance of (2) as mentioned above was applied to the dried surface.
  • the spectral characteristics of photoconductivity were measured by vapor-depositing aluminum electrodes, 5 mm. in Width and 0.5 mm. in spacing, on the surface of photosensitive layer of the photosensitive member. The result shows sufficient sensitivity over the entire region of visible light as shown in 'FIG. 2.
  • a photosensitive layer is formed between metal electrodes of 5 mm. in width and 0.5 mm. in spacing and a voltage of about v. is applied thereto and then a monochrornic light having a known intensity obtained through a spectrograph is projected to the photosensitive layer.
  • Various monochromic light are successively projected thereto.
  • the resulting photo-current between the electrodes is determined by an ampere meter.
  • the photo-current value is adjusted depending on spectral intensity distribution of the projected light and further normalized by assuming the peak value as 1. This is relative photoconductivity on the ordinate, and, the ordinate corresponds to wavelength of the projected light.
  • color developers can be obtained easily by only replacing, in the ordinary black toner colored by carbon black, the coloring agent, i.e. carbon black, by cyan, magenta, and yellow coloring matters, for example, Methylene Blue, Fuchsine, and Oramin.
  • the coloring agent i.e. carbon black
  • cyan, magenta, and yellow coloring matters for example, Methylene Blue, Fuchsine, and Oramin.
  • the surface of the above-mentioned photosensitive member was subjected to uniform negative charging in a dark place. Then light irradiation from an original image which is illuminated by white light source is applied to the surface through Wratten filter N0. 25.
  • the electrostatic image obtained by eliminating the surface charge selectively was developed by a cyan color positive toner.
  • the toner image was bias transferred onto a white copying paper. The image was fixed and the surface of the photosensitive member was cleaned.
  • the exposure time was about A second for each time and the intensity of illumination of total illuminated rays of light on the photosensitive member was about 178 lux. Thus an excellent colored image was reproduced.
  • the spectral characteristic of photoconductivity was measured by vapor-depositing two aluminum electrodes, 5 mm. in width and spaced by 0.5 mm.
  • the photosensitive layer had a sufiicient sensitivity to the entire visible light region.
  • the photosensitive member had a spectacular color reproduction in tri-color duplication using three filters as in Example 1.
  • EXAMPLE 3 Two pasty mixtures were prepared by adding to each of the photosensitive substances (1) and (2) used in Example 1 parts of a vinyl chloride-vinyl acetate copolymer resin and an adequate amount of thinner as solvent, throughly mixing them, and grinding the mixtures in a roll mill to improve dispersion.
  • the pasty mixture containing the photosensitive substance of (1) above was spread smoothly on an aluminum foil by using an appropriate spacer and a blade in such a way that the thickness of the layer was about 40 after drying. The foil was then left to stand for several hours to dry itself, then heated and dried for two hours at 60 C.
  • Example 2 On the surface of the photosensitive layer of the photosensitive member was vapor-deposited aluminum electrodes in a manner similar to Example 1 and the spectral characteristics were measured. Spectral sensitivity to entire visible ray region as shown in FIG. 2 was shown similar to the photosensitive member of Example 1.
  • the photosensitive layer is not limited to comprise two layers, an upper layer and a lower layer, but may comprise multiple layers laminated more than two layers.
  • EXAMPLE 4 On a smooth surface of an aluminum sheet, a photoconductive CdS powder layer bound with a resin of about 50,11. in thickness was formed and fixed by using about by weight of epoxy resin as a binder. Further thereon, a layer of about 5 in thickness and bound by an epoxy resin was formed and fixed as before.
  • This layer contained a mixture of Cd GeS and Zn GeSe obtained by heat synthesis in a weight ratio of 5:1.
  • These photoconductive powders were prepared by grinding blocks of Cd GeS and Zn GeSe agitating vigorously in a large amount of water While adding a small amount of hydrochloric acid dropwise to smoothen the surface of the ground particles, repeating decantation and washing, simultaneously classifying, drying and annealing at 600 C. for 5 hours.
  • the resulting photosensitive plate was also panchromatic and of high sensitivity in a Way similar to Example 1.
  • the resulting photosensitive plate gave excellent reproduction of color in a tri-color duplication using filters.
  • EXAMPLE 5 A chargeable member was obtained by laminating a transparent fluorine containing resin film or polyester film of about 15,11. in thickness to a photosensitive member obtained in similar manner to Example 1 by using an epoxy resin binder. Next, to the surface of the fluorine containing resin film of the above-mentioned chargeable member was applied +6 kv. corona discharge to have the surface charged uniformly with positive charge. Then, an original image was projected to the above-mentioned surface by a tungsten lamp of about 10 lux and simultaneously AC corona discharge of 6 kv. was applied to the same surface. Further, the entire area of previously mentioned surface was subjected to a uniform exposure for 12 seconds from a 10 w.
  • An electrophotographic photosensitive member which comprises a photoconductive layer composed of a photoconductive CdS and finely divided particles of a member selected from the group consisting of Cd SiS Cd SiSe C(14SlTe Cd GQSG, C(1 GeSe Cd4GeTe Zn 'SiS ZII Sl'SE Zn SiTe ZH GfiS ZH4GS6 and Zn GeTe said finely divided member having been annealed at a temperature of about 500-700 C. to recover the photoconductivity, wherein the CdS and said member are dispersed in a binder resin at about equivalent ratio.
  • An electrophotographic photosensitive member according to claim 1 in which an insulating layer is provided on the photosensitive layer.
  • An electrophotographic photosensitive member in which a material of the insulating layer is a member selected from the group consisting of polyester, polycarbonate, polyacetate, polystyrene, polyfiuoroethylene, polyethylene, polypropylene, polyvinyl chloride, polyvinylidene chloride, polyurethane, epoxy resin and melamine resin.

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  • Chemical & Material Sciences (AREA)
  • Inorganic Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Photoreceptors In Electrophotography (AREA)
  • Light Receiving Elements (AREA)
US61548A 1969-08-13 1970-08-06 Cds-chalcogen ternary compound mixture as photoconductive material in an electrophotographic member Expired - Lifetime US3681067A (en)

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JP44064363A JPS493845B1 (de) 1969-08-13 1969-08-13

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JP (1) JPS493845B1 (de)
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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3867139A (en) * 1971-04-20 1975-02-18 Fuji Photo Film Co Ltd Process of making a photoconductive material of cadmium sulfide and cadmium carbonate
US3873473A (en) * 1972-05-15 1975-03-25 Hitachi Ltd Sulphide solid solution having rock-salt structure and method of producing the same
US4481270A (en) * 1983-04-28 1984-11-06 Ricoh Systems, Inc. Photoreceptor containing squaric acid methine dyes
US8470287B2 (en) 2009-11-25 2013-06-25 E I Du Pont De Nemours And Company Preparation of copper zinc tin sulfide

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3867139A (en) * 1971-04-20 1975-02-18 Fuji Photo Film Co Ltd Process of making a photoconductive material of cadmium sulfide and cadmium carbonate
US3873473A (en) * 1972-05-15 1975-03-25 Hitachi Ltd Sulphide solid solution having rock-salt structure and method of producing the same
US4481270A (en) * 1983-04-28 1984-11-06 Ricoh Systems, Inc. Photoreceptor containing squaric acid methine dyes
US8470287B2 (en) 2009-11-25 2013-06-25 E I Du Pont De Nemours And Company Preparation of copper zinc tin sulfide

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Publication number Publication date
DE2040163C3 (de) 1974-09-26
JPS493845B1 (de) 1974-01-29
GB1304863A (de) 1973-01-31
DE2040163A1 (de) 1971-03-18
DE2040163B2 (de) 1974-03-07

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