US3628981A - Liquid toner development - Google Patents

Liquid toner development Download PDF

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Publication number
US3628981A
US3628981A US43466A US3628981DA US3628981A US 3628981 A US3628981 A US 3628981A US 43466 A US43466 A US 43466A US 3628981D A US3628981D A US 3628981DA US 3628981 A US3628981 A US 3628981A
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US
United States
Prior art keywords
liquid
developer
highly volatile
image
process according
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
US43466A
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English (en)
Inventor
Seiji Matsumoto
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
Priority claimed from JP4526969A external-priority patent/JPS4818859B1/ja
Application filed by Fuji Photo Film Co Ltd filed Critical Fuji Photo Film Co Ltd
Application granted granted Critical
Publication of US3628981A publication Critical patent/US3628981A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G15/00—Apparatus for electrographic processes using a charge pattern
    • G03G15/06—Apparatus for electrographic processes using a charge pattern for developing
    • G03G15/10—Apparatus for electrographic processes using a charge pattern for developing using a liquid developer
    • G03G15/11—Removing excess liquid developer, e.g. by heat
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G15/00—Apparatus for electrographic processes using a charge pattern
    • G03G15/06—Apparatus for electrographic processes using a charge pattern for developing
    • G03G15/10—Apparatus for electrographic processes using a charge pattern for developing using a liquid developer

Definitions

  • Mahassel and Peter H. Kondo ABSTRACT In developing an electrostatic latent-imagebearing surface with a liquid developer containing a highly volatile liquid component, a thin layer of residual liquid developer is formed on the surface. This thin residual developer layer is substantially removed by subjecting the layer to a stream of gas containing a relatively large quantity of the vapor of the highly volatile liquid component. Toner background deposit and image quality is improved with this technique.
  • the formation and development of images on a surface of photoconductive materials by electrostatic means is well known.
  • One conventional process involves placing a uniform electrostatic charge on a photoconductive insulating layer comprising zinc oxide powder and a resinous binder carrier on a conductive paper substrate, exposing the layer to a lightand-shadow image to dissipate the charge on the areas of the layer exposed to the light and developing the resulting electrostatic latent image by depositing on the image a charged toner which is dispersed in an insulating carrier liquid.
  • the charged toner may be suitably colored and may have a polarity of charge identical or opposite to that of the latent image to be developed. If the polarity of the charge of the toner is identical to that of the latent image, reversal development will occur whereas a toner having a charge opposite of that of the latent image will be attracted to the latent image.
  • an imaging member having a recording surface bearing an electrostatic latent image
  • developing the latent image with a liquid developer containing a highly volatile liquid component to form an imaged recording surface having a thin layer of developer liquid thereon
  • directing a stream of gas containing a relatively large quantity of the vapor of the volatile liquid component against the imaged recording surface thereby removing the thin layer of developer liquid by a squeezing action.
  • the vapor pressure of the vapor in the gas should be substantially equal to the saturated vapor pressure of the volatile liquid at the temperature at which the gas is employed.
  • the high concentration of vapor in the gas stream permits removal of the thin layer of developer liquid on the imaged surface and return of this removed liquid developer to the developer bath without undue loss of the volatile liquid component of the liquid developer.
  • the high vapor content of the stream of gas prevents fluctuations in the image density to occur on the imaged surface during the squeezing operation.
  • the carrier liquids employed in the liquid developers of this invention comprise liquid components having low volatility mixed in suitable ratios with liquid components having high volatility to pennit normal handling in conventional liquid development electrostatographic machines.
  • Any suitable highly volatile liquid may be employed as the highly volatile liquid component in the carrier liquid of this invention.
  • Typical highly volatile liquids include cyclohexane, carbon tetrachloride, n-hexane, fluorinated hydrocarbons such as 1,1,2-trichloro-l,2,2trifluoroethylene, and the like.
  • the expression "highly volatile is intended to include liquids having a boiling point between about and about 200 F.
  • the liquid developer component having a high degree of volatility is used in the developer to dissolve the conventional resinous component of the liquid developer and to promote rapid drying of the imaged recording member.
  • Any suitable low volatility liquid may be employed in the liquid developers of this invention.
  • Typical low volatility liquids include high boiling point petroleum fractions such as kerosene, isoparaffins and the like.
  • the expression low volatility is intended to include liquids having a boiling point greater than about 250 F.
  • the high boiling point liquid is employed in liquid developers to facilitate handling and to insure stability for long periods of time.
  • Liquid developers containing one or more of the above described components are well known in the prior art. Generally, for practical drying speeds, at least about 5 percent highly volatile liquid based on the total weight of carrier liquid is preferred.
  • the vapor pressure of the highly volatile liquid component of the carrier liquid should be close to its saturated vapor pressure at the average operating temperature of the gas stream. Satisfactory results are achieved with gas-stream temperatures below about the boiling point of said highly volatile carrier liquid component.
  • the high concentration of vapor in the one or more streams of gas employed in this invention prevents abrupt evaporation of the highly volatile component of the liquid developer thereby preventing degradation of image quality.
  • the high concentration of vapor in the gas stream also permits recovery and reuse of the liquid developer removed from the imaged surface without significant changes in the relative concentration of the highly volatile liquid in the recovered liquid developer.
  • the concentration of the vapors should exceed the upper explosion limit. More preferably, the flammable vapor may be admixed with inert gases such as nitrogen, carbon dioxide or vapors of nonflammable solvents containing a halogen. Obviously, in continuous processes where air from the ambient atmosphere becomes admixed with the gas stream, continuous introduction of a predetermined amount of inert gases or vapors will reduce the danger of explosions.
  • the apparatus employed to carry out the process of this invention may be airtight and the internal pressure may be maintained slightly higher than the external pressure. The velocity of the gas stream should be sufi'lcient to cause the: developer liquid in the thin residual layer to visibly flow away from the point of impact of the gas stream on the imaged recording surface.
  • a recording element I carrying an electrostatic latent image on the upper surface is conveyed in the direction indicated by the arrow.
  • a container 2 of developer liquid 3 is positioned below the path of travel of recording element l.
  • the developer liquid 3 is fed by pump 4 into developing head 5.
  • the developing liquid supplied by developing head .5 contacts and develops the electrostatic latent image carried on the upper surface of recording element 1 supported by an electrically grounded conductive support member 14. Although some of the excess developer liquid 3 flows over the edges of recording element 1 into container 2, some of the developer liquid remains deposited as a thin layer on the upper surface of recording element 1. This thin layer of developer liquid is subjected to at least one gas stream supplied by nozzle 6.
  • the gas for the gas stream supplied by nozzle 6 is drawn into the ducts 7 and 7' from the area immediately adjacent to the exit opening of nozzle 6 and is delivered to 1101.118 6 by means of fan 8.
  • Recording element 1 is supported by roller 9 positioned immediately below the exit opening of nozzle 6.
  • the strong stream of gas emitted from nozzle 6 presses recording element 1 against roller 9 and removes the thin layer of liquid developer on the upper surface of recording element 1 by a squeezing action thereby causing the developer liquid to flow over both edges of recording element 1 back. into container 2.
  • a portion of the highly volatile component of the carrier liquid is vaporized.
  • recording element 1 is transported over a container 10 of cleaning liquid ll.
  • Cleaning liquid 11 is pumped by means of pump 13 to cleaning head 12 located over the upper surface of recording element 1. The cleaning liquids supplied to the upper surface of the recording element l by cleaning head 12 reduces background toner deposits and decreases the tendency of the images to smear.
  • the subsequent treatment of recording element 1 with cleaning liquid 11 is optional.
  • the cleaning operation is employed where images or extremely high quality are required. It is apparent that the removal of the thin layer of liquid developer after development from the upper surface of the recording element 1 by the air squeezing treatment greatly reduces the rate of contamination of cleaning liquid 11 with liquid developer materials carried over on the surface of recording element 1 from the development operation. Thus, in automatic machines in which the cleaning liquid is recycled, the useful life of the cleaning liquid is lengthened considerably.
  • An imaging process comprising providing an electrostatic latent-image-bearing surface, contacting said electrostatic latent-image-bearing surface with a liquid developer comprising toner particles and carrier liquid, said carrier liquid comprising at least one highly volatile liquid whereby a thin layer of residual liquid developer adheres to said electrostatic latent-image-bearing surface and at least a portion of said toner particles deposits on said electrostatic latent-imagebearing surface in image configuration, and directing a stream of gas against said thin layer to remove said residual liquid developer from said electrostatic latent-image-bearing surface, said gas comprising a vapor of said highly volatile liquid at a vapor pressure substantially equal to the saturated vapor pressure of said vapor at the average temperature of said gas stream.
  • said carrier liquid comprises at least one highly volatile liquid and at least one liquid having low volatility.
  • An imaging process including recycling said gas containing said vapor of said highly volatile liquid and removing residual liquid developer from additional image bearing surfaces.
  • An imaging process including collecting said residual liquid developer removed by said gas stream and reusing said residual liquid developer to develop additional electrostatic latent-image-bearing surfaces.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Cleaning In Electrography (AREA)
  • Wet Developing In Electrophotography (AREA)
US43466A 1969-06-09 1970-06-04 Liquid toner development Expired - Lifetime US3628981A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP4526969A JPS4818859B1 (enrdf_load_stackoverflow) 1969-06-09 1969-06-09
GB4526969 1969-06-09

Publications (1)

Publication Number Publication Date
US3628981A true US3628981A (en) 1971-12-21

Family

ID=26265549

Family Applications (1)

Application Number Title Priority Date Filing Date
US43466A Expired - Lifetime US3628981A (en) 1969-06-09 1970-06-04 Liquid toner development

Country Status (4)

Country Link
US (1) US3628981A (enrdf_load_stackoverflow)
DE (1) DE2028388A1 (enrdf_load_stackoverflow)
FR (1) FR2050118A5 (enrdf_load_stackoverflow)
NL (1) NL7008259A (enrdf_load_stackoverflow)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3802388A (en) * 1973-01-05 1974-04-09 Poma V Photocopy liquid developing apparatus
US5643707A (en) * 1995-07-31 1997-07-01 Xerox Corporation Liquid developer compositions

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3811765A (en) * 1972-01-21 1974-05-21 Electroprint Inc Contact-transfer electrostatic printing system
JPS5393842A (en) * 1977-01-28 1978-08-17 Canon Inc Method and apparatus for developing electrostatic latent image

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3356498A (en) * 1964-11-09 1967-12-05 Dow Chemical Co Electrophotographic method comprising rinsing the imaged plate
US3382763A (en) * 1965-05-21 1968-05-14 Addressograph Multigraph Photoelectrostatic copying machine
US3498917A (en) * 1965-10-23 1970-03-03 Philips Corp Liquid developer for electrostatic images

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3356498A (en) * 1964-11-09 1967-12-05 Dow Chemical Co Electrophotographic method comprising rinsing the imaged plate
US3382763A (en) * 1965-05-21 1968-05-14 Addressograph Multigraph Photoelectrostatic copying machine
US3498917A (en) * 1965-10-23 1970-03-03 Philips Corp Liquid developer for electrostatic images

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3802388A (en) * 1973-01-05 1974-04-09 Poma V Photocopy liquid developing apparatus
US5643707A (en) * 1995-07-31 1997-07-01 Xerox Corporation Liquid developer compositions

Also Published As

Publication number Publication date
DE2028388A1 (de) 1970-12-17
NL7008259A (enrdf_load_stackoverflow) 1970-12-11
FR2050118A5 (enrdf_load_stackoverflow) 1971-03-26

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