US3607363A - Process for producing photoconductive material - Google Patents

Process for producing photoconductive material Download PDF

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Publication number
US3607363A
US3607363A US675800A US3607363DA US3607363A US 3607363 A US3607363 A US 3607363A US 675800 A US675800 A US 675800A US 3607363D A US3607363D A US 3607363DA US 3607363 A US3607363 A US 3607363A
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US
United States
Prior art keywords
photoconductive
powder
particles
core material
parts
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
US675800A
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English (en)
Inventor
Shigeru Sadamatsu
Hiroyuki Kaneko
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.)
Fujifilm Holdings Corp
Original Assignee
Fuji Photo Film Co Ltd
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
Application filed by Fuji Photo Film Co Ltd filed Critical Fuji Photo Film Co Ltd
Application granted granted Critical
Publication of US3607363A publication Critical patent/US3607363A/en
Anticipated expiration legal-status Critical
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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

Definitions

  • a process for the production of a photoconductive powder which comprises coating particles ofa photoconductive material onto the surface of particles ofa core materiall having an absorption ratio of less than 80 percent, at a thickness of 5 microns, to a light in the main region of the intrinsic sensitivity wave length region in which said photoconduetive material exhibits a photoconductive property.
  • PROCESS FOR PRODUCING PHOTOCONDUCTIVE MATERIAL BACKGROUND OF THE INVENTION 1.
  • This invention relates to a process for producing a photoconductive material, and in particular, a photoconductive powder to by used for electrophotographic print marking processes.
  • the residual potential of the powder layer is high and the electrostatic force between the support and the particles is relatively strong, whereas, on a sufficiently exposed area, the residual potential is low, resulting in a relatively weak electrostatic force between the support and the particles.
  • an external physi cal force e.g., an air stream, electromagnetic force, or vibration of the layer, the powder particles with weakened electrostatic bonds are removed to form an image of powder particles in the areas with strong electrostatic bond.
  • a number of characteristics are required for a photoconductive powder to be used in the above-mentioned electric photographic print marking process. These are as follows: (1) high charging capacity, (2) low attenuation of the electrostatic potential of the charged particles in a dark place, (3) high sensitivity to light, (4) very low residual potential after exposure, (5) good powderspreading and powder-removing properties, (6) free adhesive of bonding properties between the particles, and (7) spherical powder form.
  • the grain size is to be within a suitable range, since, although an image having a higher degree of resolution is obtained as the grain size gets smaller, a very small grain size impairs the powder-spreading and -removing property, that is, the fiow property is lowered and adhesive properties appear.
  • the powder be scarcely affected by external conditions, such as, temperature and humidity, and the mechanical strength, in particular, friction resistance of the powder must be large.
  • Other requirements are good fixing properties and suitable specific gravity, but after all, the most important factor is that the sensitivity to light be high, and the residual potential after exposure be low.
  • a process for the production of a photoconductive powder which is characterized by mixing a composition comprising photoconductive material and others, at least one of the components being in a vapor, solution or melt state, with such a powder that the absorption ratio is less than 80 percent at a thickness of 5 microns, to light in the main region of the intrin' sic sensitivity wave length region wherein said photoconductive material has a photoconductive property, thereby adhering said composition to the surface of said powder.
  • the photoconductive powder obtained by the invention differs completely from those commonly used in the prior art, particularly, in the fact that the photoconductive material is coated onto the surface ofa powder of various organic and inorganic materials.
  • a material to be coated preferably has a lower absorption to a light of the intrinsic sensitivity wave length region wherein a photoconductive material for coating has a photoconductive property.
  • the photoconductive powder having such structure has such a low residual p0tential, after exposure, and such a high image contrast of latent image, in spite ofits very sensitivity, small attenuation of electric potential in a dark place and high charging capacity, that a fog-free, sharp image can be obtained with a small exposure quantity.
  • the other characteristics can all be satisfied, because a material having suitable shape, grain size and fixing property is used by selecting the material to be adhered.
  • a powder to be adhered whose absorption ratio is less than percent, at a thickness of about 5 microns, to a light in the main region of the intrinsic sensitivity wave length region wherein a photoconductive material has a photoconductive property, is kept in a stationary bed or fluidized bed using a suitable gas or liquid as a medium, or in a floated or suspended state, mixed with photocon ductive material containing as at least one component a photoconductive material at least one component of which is in a vapor, solution or melt state, or in a. dispersed state using a suitable gas or liquid as a medium by pouring, spraying, spreading, adding or the like, thereby to form a mixed system.
  • the resulting mixture is fluidized, refluxed, stirred or kneaded adequately by an electromagnetic, thermal or mechanical external force to form a continuous film or fine spots of the covering material containing the photoconductive material around one or more powder particles.
  • the photoconductive powder prepared by this method has very excellent characteristics.
  • the powder used as the material to be adhered is not markedly dissolved in, melted or etched by the adhering material, when the powder is stirred, mixed or kneaded therewith as a mixed system. Where there occurs a marked change, good characteristics cannot be obtained. However, if the powder is suitably swelled, surfacedissolved or surfaceetched with at least one of the components of the mixed system, or mixed therewith, while being kept at a temperature sufficient to cause a suitable surface melting, or these take place simultaneously, the coating material is tenaciously bonded to the powder, resulting in a marked rise in mechani* cal strength, in particular, wear resistance, as well as in other characters.
  • Photoconductive insulating compounds investigated are, for example, selenium, cadmium sulfide, zinc oxide, or anthracene, while a nonphotoconductive powder to be bonded includes small beads of thermoplastic or thermosetting resins, glasses, inorganic salts, metal oxides, or other finely divided particles. They may be dyed or colored by suitable coloring matter, if desired.
  • These materials for nonconductive powder should be optically quite transparent to light in the spectrum region at which the photoconductive layer bonded thereon is sensitive.
  • the transparency of the materials must be sufficiently high so that the less than 80 percent of the incident. light is absorbed by the material when it is formed into a layer of 5 microns in thickness in the spectral region in which the photoconductive material is substantially sensitive.
  • photoconductive powder having very excellent electrophotographic characteristics, flowing properties, fixing properties, and mechanical strength can be produced in a very simple and economical manner by selecting and combining suitably a photoconductive material as a composing component, binding agent, solvent, medium material and powder material.
  • EXAMPLE 1 Photoconductive Zinc Oxide 150 parts (by weight) Silicone Varnish (FSR-l07: Trade Mark, manufactured by Fuji Polymer Industry Co., Ltd.) 60 parts Cyclohexane 80 parts Toluene parts Copper Stearate 0.2 part
  • EXAMPLE 2 Photoconductive Cadmium Yellow Orange 150 parts by weight Silicone Varnish (KR-2l l Trade Mark, Manufactured by Shinetsu Chemical Industry Co, Ltd.) 40 parts Toluene 120 parts These compounds were mixed or kneaded for 16 hours by the use of a ball mill of porcelain.
  • the surface of the polyethyl methacrylate powder was suitably swelled or surface-dissolved with the toluene in the dispersion, so a powder having a very excellent wear resisting property was obtained in spite of a small amount of the binding agent used.
  • EXAMPLE 4 Photoconductive Zinc Oxide 150 parts by weight Silicone Varnish (ES-l00l Trade Mark, Manufactured By Shinetsu Chemical Industry Co. Ltd.) 40 parts Diacetone Alcohol l50 parts Amorphous Silica (AerosikTrade Mark, Manufactured By Degussa Co. Ltd.) 15 parts The foregoing dispersion was sprayed against a polymethyl methacrylate powder to be cascade-spread in a proportion of parts of parts, continuously stirred with the feeding of warm air thereto, and the dried powder was taken out of the system.
  • EXAMPLE 6 ln a cylindrical vacuum deposit apparatus, selenium vapor, heated to about 250 C., was ejected from a coaxial source towards the center of the cylinder. From the top end of the apparatus, the sufficiently cleaned transparent polymethylmethacrylate resin powder with an average grain diameter of 80 microns, which was heated to 60 C., was constantly flowed down along the axis of the cylinder. The powder particles were vacuum coated with selenium to give a high sensitive photoconductive powder.
  • Light and photoconductive property used herein mean light" in a broad sense, such as containing infrared ray, visible rays, ul traviolet rays, radiation and corpuscular ray, and photocon ductive phenomenon in which the electric resistance is reduced by radiation thereof.
  • a process for producing a photoconductive powder having high sensitivity and low residual potential and capable of providing clear electrophotographic images comprising the steps of forming a suspension of particles of a core material in a fluid media, said core material having an absorption ratio of less than 80 percent, at a thickness of 5 microns, to a light in the main region of the intrinsic sensitivity wavelength region in which the photoconductive material exhibits a photoconductive property; contacting said particles of said core material while in suspension with a mixture of a photoconductive powder and solvent; maintaining said core material, photoconductive powder, and said solvent in suspension to effect intimate mixing thereof, continuing said mixing for a period of time sufficient for said solvent to dissolve the surface of said core material and until a continuous film of said photoconductive material is deposited onto the surface of the core material; effecting removal of said solvent from said fluid suspension to dry said coated core material, and recovering the resulting finely particulate product.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Photoreceptors In Electrophotography (AREA)
  • Developing Agents For Electrophotography (AREA)
US675800A 1966-10-18 1967-10-17 Process for producing photoconductive material Expired - Lifetime US3607363A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP6852766A JPS5431369B1 (en)) 1966-10-18 1966-10-18

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US3607363A true US3607363A (en) 1971-09-21

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JP (1) JPS5431369B1 (en))
GB (1) GB1210071A (en))

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3775103A (en) * 1967-02-13 1973-11-27 Fuji Photo Film Co Ltd Electrophotographic material and process for producing same
US3998634A (en) * 1973-04-24 1976-12-21 Fuji Photo Film Co., Ltd. Powder electrophotographic method
US4639402A (en) * 1985-08-02 1987-01-27 Xerox Corporation Photoreceptor containing selenium particles coated with a reaction product of a hydrolyzed silane
US4780386A (en) * 1986-11-28 1988-10-25 Xerox Corporation Selenium alloy treatment

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4314013A (en) * 1979-04-04 1982-02-02 Xerox Corporation Particle formation by double encapsulation

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2924519A (en) * 1957-12-27 1960-02-09 Ibm Machine and method for reproducing images with photoconductive ink
US3080318A (en) * 1958-03-13 1963-03-05 Xerox Corp Three-component xerographic toner
US3143508A (en) * 1957-07-03 1964-08-04 Edward K Kaprelian Developer for electrophotography
US3317315A (en) * 1962-04-30 1967-05-02 Rca Corp Electrostatic printing method and element
US3318697A (en) * 1964-04-28 1967-05-09 Minnesota Mining & Mfg Copy sheet having a layer of thermally rupturable hollow microcapsules on a conductive backing and the method of use
US3338991A (en) * 1964-07-02 1967-08-29 Xerox Corp Method of forming electrostatographic toner particles
US3362846A (en) * 1964-04-06 1968-01-09 Dow Chemical Co Method of coating particulate material with metal carbonates
US3400011A (en) * 1964-09-30 1968-09-03 Chevron Res Method of coating water-soluble particles
US3415548A (en) * 1965-09-16 1968-12-10 Ultrasonics Ltd Transducer mounting

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3143508A (en) * 1957-07-03 1964-08-04 Edward K Kaprelian Developer for electrophotography
US2924519A (en) * 1957-12-27 1960-02-09 Ibm Machine and method for reproducing images with photoconductive ink
US3080318A (en) * 1958-03-13 1963-03-05 Xerox Corp Three-component xerographic toner
US3317315A (en) * 1962-04-30 1967-05-02 Rca Corp Electrostatic printing method and element
US3362846A (en) * 1964-04-06 1968-01-09 Dow Chemical Co Method of coating particulate material with metal carbonates
US3318697A (en) * 1964-04-28 1967-05-09 Minnesota Mining & Mfg Copy sheet having a layer of thermally rupturable hollow microcapsules on a conductive backing and the method of use
US3338991A (en) * 1964-07-02 1967-08-29 Xerox Corp Method of forming electrostatographic toner particles
US3400011A (en) * 1964-09-30 1968-09-03 Chevron Res Method of coating water-soluble particles
US3415548A (en) * 1965-09-16 1968-12-10 Ultrasonics Ltd Transducer mounting

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3775103A (en) * 1967-02-13 1973-11-27 Fuji Photo Film Co Ltd Electrophotographic material and process for producing same
US3998634A (en) * 1973-04-24 1976-12-21 Fuji Photo Film Co., Ltd. Powder electrophotographic method
US4639402A (en) * 1985-08-02 1987-01-27 Xerox Corporation Photoreceptor containing selenium particles coated with a reaction product of a hydrolyzed silane
US4780386A (en) * 1986-11-28 1988-10-25 Xerox Corporation Selenium alloy treatment

Also Published As

Publication number Publication date
DE1597843A1 (de) 1970-09-17
DE1597843B2 (en)) 1975-09-11
JPS5431369B1 (en)) 1979-10-06
GB1210071A (en) 1970-10-28

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