EP0052789A2 - Procédé de transfert d'un dessin de pigment - Google Patents

Procédé de transfert d'un dessin de pigment Download PDF

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Publication number
EP0052789A2
EP0052789A2 EP81109009A EP81109009A EP0052789A2 EP 0052789 A2 EP0052789 A2 EP 0052789A2 EP 81109009 A EP81109009 A EP 81109009A EP 81109009 A EP81109009 A EP 81109009A EP 0052789 A2 EP0052789 A2 EP 0052789A2
Authority
EP
European Patent Office
Prior art keywords
carrier
liquid
spacers
charge image
copy
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.)
Granted
Application number
EP81109009A
Other languages
German (de)
English (en)
Other versions
EP0052789B1 (fr
EP0052789A3 (en
Inventor
Roland Dr. Moraw
Renate Schädlich
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.)
Hoechst AG
Original Assignee
Hoechst AG
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 Hoechst AG filed Critical Hoechst AG
Priority to AT81109009T priority Critical patent/ATE12432T1/de
Publication of EP0052789A2 publication Critical patent/EP0052789A2/fr
Publication of EP0052789A3 publication Critical patent/EP0052789A3/de
Application granted granted Critical
Publication of EP0052789B1 publication Critical patent/EP0052789B1/fr
Expired 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
    • G03G15/14—Apparatus for electrographic processes using a charge pattern for transferring a pattern to a second base
    • G03G15/16—Apparatus for electrographic processes using a charge pattern for transferring a pattern to a second base of a toner pattern, e.g. a powder pattern, e.g. magnetic transfer
    • G03G15/163—Apparatus for electrographic processes using a charge pattern for transferring a pattern to a second base of a toner pattern, e.g. a powder pattern, e.g. magnetic transfer using the force produced by an electrostatic transfer field formed between the second base and the electrographic recording member, e.g. transfer through an air gap
    • G03G15/1635—Apparatus for electrographic processes using a charge pattern for transferring a pattern to a second base of a toner pattern, e.g. a powder pattern, e.g. magnetic transfer using the force produced by an electrostatic transfer field formed between the second base and the electrographic recording member, e.g. transfer through an air gap the field being produced by laying down an electrostatic charge behind the base or the recording member, e.g. by a corona device

Definitions

  • the invention relates to a method for transferring a pigment image produced by treatment with a liquid developer from an electrostatic charge image from a charge image carrier to a copy carrier with the aid of an electrical field.
  • the solution to this problem is based on the method described at the outset for transferring an electrostatic charge image made visible with liquid developer, and is characterized in that the liquid developer layer with imagewise arranged pigment distribution is transferred over an air gap which forms a small distance.
  • an air gap is set which is spaced from 5 to 50 ⁇ m. This can be achieved in a simple manner by using spacers.
  • the amount of liquid developer used for development on the charge image carrier is expediently reduced before the transfer.
  • All previously known materials can serve as charge carriers, such as those with insulating surfaces, for example dielectric papers, foils or drums with an insulating cover layer, on which charge images are generated electrographically or electrophotographically.
  • Suitable materials are preferably used for the photoconductor. Any photoconductor materials are suitable for this, for example also ribbon-shaped photoconductors made of an aluminum-vapor-coated polyester carrier film which has a photoconductive layer made of, for example, poly-N-vinylcarbazole and trinitrofluorenone.
  • Inorganic photoconductor materials for example based on selenium or zinc oxide, can also be used.
  • the liquid developers which can be used are preferably pigment dispersions which are customary for making charge images visible, and which generally consist of a liquid hydrocarbon as the dispersing liquid and pigments dispersed therein, mostly with ionic charge, with, if appropriate, further additives.
  • Paper sheets such as are usually used in electrostatic copying machines, can be used as the copy carrier.
  • Foils are preferably used, but also adapted paper sheets or foils with surface structures that allow the formation of a sufficient air gap between the charge image carrier and the copy carrier.
  • the latent electrostatic charge images are developed in a conventional manner by electrophoretic deposition of the charged pigments with full coverage of the charge image carrier with developer liquid.
  • the amount of pigment deposited is largely proportional to the charge density.
  • the transfer according to the invention is achieved using commercially available liquid developers for charge images, the charge images being able to be generated using various techniques, for example electrostatically using write electrodes or by means of photoconductivity.
  • the transfer is also successful with liquid developers in which electrically neutral pigments are dispersed or dyes are dissolved in an organic or aqueous liquid.
  • the preceding development process is of no importance for the transmission according to the invention, for example, any other known technique can also be used.
  • the preferred embodiment of the invention is the transfer of the developer liquid layer after previous electrophoretic development.
  • the pigment image made visible with developer liquid is transferred from the charge image carrier without contact via an air gap to the copy carrier with the aid of an electric field.
  • the usual transmission has been by contact transmission, in which the copy carrier has a full surface benet was applied or pressed onto the charge image carrier provided with developer liquid with simultaneous action of a homogeneous electric field.
  • the air gap is set by spacers, which make up up to 10 percent, preferably 2 percent or less, of the copy carrier surface and can move with the charge image and the copy carrier or can also be arranged in a fixed manner. Spacers which are connected to the surface of the copy carrier are very particularly suitable.
  • FIGS. 1 to 3 show schematically the development of a latent electrostatic image and the transfer according to the invention
  • Figure 2 shows a cross section through the layers with surface structure in the transfer process
  • Figure 3 schematically shows the accumulation of color particles in the liquid layer adjacent to the charge carrier.
  • the thickness of the liquid film remaining on the photoconductor drum 1 is determined by the stripping roller 4 reduced.
  • the copying material 5 is guided at a distance D2 above the layer of developer liquid of thickness D1.
  • Spacers 6 are thin monofilaments with a diameter of 40 ⁇ m at a mutual distance of 3-5 mm (as can be seen from the cross-sectional illustration in FIG. 1 a for section A - B in FIG. 1) between guide plates 7 a / b and around the deflection roller 8 stretched around.
  • the transmission corona operated at approx. + 6 kV is designated by 9.
  • the transferred pigment image is composed of points of 50 - 100 ⁇ m diameter with different blackening in a statistical distribution. By weighing out a larger number of copies which are made when the thermal fixation is switched off, it is determined that the discharge of dispersing liquid is reduced by 30% to 50% in the gap transfer compared to conventional contact transfer on the same copier.
  • Various aliphatic hydrocarbons with boiling ranges between approximately 150 and 230 ° C are used as the dispersing liquid.
  • the gap D2 is set by threads oriented in the running direction as spacers installed on the device side between the charge carrier layer provided with developer liquid and the copy carrier surface.
  • the favorable gap area for D2 becomes 50 ⁇ m and represents depending on the strength of the applied electrical transmission field determined under.
  • the transmission corona 9 which is located approximately 1 cm from the photoconductor drum 1, is supplied with + 6.1 kV. Even at + 5.4 kV corona voltage, the efficiency of the transmission is noticeably worse.
  • the transmission field is of the order of 10 kV / cm.
  • Another technique for adjusting the air gap according to the invention with the aid of spacers between the surface of the charge carrier and the copy carrier is to allow fine nets, such as those used for screen printing, or perforated foils with a large proportion of perforated area to run between them.
  • the copies are somewhat disturbed by the threads or by the webs between the holes.
  • the optimal distance range can be determined more precisely. It has been shown that copies made with an air gap distance of 28 ⁇ m, achieved by means of appropriate perforated foils, provide dense or black image areas in good quality, the halftone reproduction being good due to statistically distributed points.
  • the technology of the moving spacer used in a preferred embodiment can be designed very practically by integrating the spacer into the copy carrier surface.
  • the copy carrier for example a commercially available copy paper for electrophotographic copiers, or else a film, is provided with a colorless or white pigment or polymer dispersion of a predetermined particle size.
  • a copy carrier in the surface of which a specific structure is embossed, as can be seen in the cross section from FIG. 2 for a thermoplastic film made of, for example, polyvinyl chloride with a statistically roughened surface.
  • a thermoplastic film made of, for example, polyvinyl chloride with a statistically roughened surface.
  • embossing rollers The smallest, determined width for the gap D2 according to the invention is around 5 ⁇ m. Good and reproducible copies are obtained in particular with gap widths between 8 .mu.m and 25 .mu.m, which is why this area proves to be particularly favorable.
  • the contact surface of the spacers contacting the charge carrier layer is also decisive in comparison to the total surface of the copy carrier.
  • the relative contact area it was determined, should be less than 10% of the total area, but is preferably less than or equal to approximately 2% of the total area. It was further determined that the area effectively occupied by a single spacer, which is visible by imprint on the copy surface, should be less than about 0.04 mm 2 , preferably less than 0.01 mm 2 .
  • the average distance between adjacent spacers can be less than about 3 mm, preferably less than 1 mm.
  • the area stretched between the spacers can be smooth or finely structured.
  • the stripping roller 4 limits the liquid layer to 12-14 pm in thickness, good copies are obtained with spacers of approximately 25 to 30 pm. It can be concluded from this that the air gap and the thickness of the liquid layer to be transferred should preferably be of similar size.
  • a large evaporation is undesirable in this case because of the increasing viscosity of the liquid developer. It can be suppressed more and more effectively by correspondingly less volatile dispersants, for example towards higher evaporation numbers.
  • the distance between the stripper roller 4 and the surface of the charge carrier 1 is reduced by shrinking films on the stripper roller, for example according to German patent application P 30 21 050.5, so that the layer thicknesses of the liquid developer with a dispersant with a high evaporation number are only about 8 ⁇ m or is about 3 ⁇ m, the copy quality changes with respect to the maximum density and the halftone reproduction of the dot formally composed pictures not noticeable.
  • the discharge of dispersing liquid decreases sharply, surprisingly more at the toner-free areas than at the concreted areas, to only about 9% of the initial value when transferring contact from a completely white template and to only about 14% of a template with 10% coverage.
  • liquid developer layers D1 of not more than 8 ⁇ m
  • the liquid layer very likely consists, as shown in FIG. 3, predominantly of areas of high pigment concentration 11 and of areas of low pigment concentration 12.
  • the outer partial layer 10 depleted in dispersed pigment is probably used removed with the help of the stripper roller 4.
  • the thickness of this residual liquid layer is less than 8 microns and can be about 3 microns or less.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Wet Developing In Electrophotography (AREA)
  • Liquid Developers In Electrophotography (AREA)
  • Pigments, Carbon Blacks, Or Wood Stains (AREA)
  • Electrostatic Charge, Transfer And Separation In Electrography (AREA)
EP81109009A 1980-11-20 1981-10-27 Procédé de transfert d'un dessin de pigment Expired EP0052789B1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT81109009T ATE12432T1 (de) 1980-11-20 1981-10-27 Verfahren zum uebertragen eines pigmentbildes.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3043736 1980-11-20
DE3043736A DE3043736C2 (de) 1980-11-20 1980-11-20 Verfahren zum Übertragen eines Tonerbildes

Publications (3)

Publication Number Publication Date
EP0052789A2 true EP0052789A2 (fr) 1982-06-02
EP0052789A3 EP0052789A3 (en) 1983-02-09
EP0052789B1 EP0052789B1 (fr) 1985-03-27

Family

ID=6117182

Family Applications (1)

Application Number Title Priority Date Filing Date
EP81109009A Expired EP0052789B1 (fr) 1980-11-20 1981-10-27 Procédé de transfert d'un dessin de pigment

Country Status (5)

Country Link
US (1) US4478924A (fr)
EP (1) EP0052789B1 (fr)
JP (1) JPS57114167A (fr)
AT (1) ATE12432T1 (fr)
DE (2) DE3043736C2 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0435517A2 (fr) * 1989-12-28 1991-07-03 Am International Incorporated Dispositif et méthode de transfert sur une bande porteuse pour une presse à imprimer électrophotographique

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
IT1155011B (it) * 1982-01-11 1987-01-21 Savin Corp Metodo per aumentare la densita' di immagini elettrofotografiche sviluppate mediante sviluppatore liquido con trasferimento dell'immagine attraverso uno spazio d'aria e composizione di sviluppo da usarsi in tale metodo
US4841334A (en) * 1987-07-28 1989-06-20 Kentek Information Systems, Inc. Electrographic printer with small diameter drum and charged transfer belt
US4894686A (en) * 1987-08-31 1990-01-16 Olin Hunt Specialty Prod Transfer roller
US4763157A (en) * 1987-08-31 1988-08-09 Olin Hunt Specialty Products Inc. Transfer roller
US4855784A (en) * 1987-12-21 1989-08-08 Olin Hunt Specialty Products Inc. Web backing plate
JP2752886B2 (ja) * 1993-06-30 1998-05-18 東北リコー株式会社 トナー画像転写装置

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2892708A (en) * 1955-01-03 1959-06-30 Haloid Xerox Inc Xerographic transfer process
CH442992A (de) * 1966-08-19 1967-08-31 Electrostatic Printing Corp Vorrichtung zum elektrostatischen Übertragen eines Pulverbildes
FR2002025A1 (fr) * 1968-02-16 1969-10-03 Eastman Kodak Co
DE1597855A1 (de) * 1966-11-07 1970-08-20 Ibm Elektrostatische Druckvorrichtung
DE2821964B2 (de) * 1977-05-20 1980-04-24 Ricoh Co., Ltd., Tokio Verfahren zur Kontaktierung eines Bildempfangsmaterials mit einem Bildträger sowie Übertragungs-Koronavorrichtung zur Durchführung eines solchen Verfahrens
DE3119027A1 (de) * 1980-05-13 1982-03-25 Savin Corp., 10595 Valhalla, N.Y. Elektrofotographisches verfahren und einrichtungen zur durchfuehrung des verfahrens

Family Cites Families (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US869004A (en) * 1907-04-17 1907-10-22 Freeman T Martin Hemp-brake.
US2839400A (en) * 1953-10-30 1958-06-17 Rca Corp Electrostatic printing
US3071645A (en) * 1959-09-09 1963-01-01 Gen Dynamics Corp Recorder utilizing electrostatic charges
US3203394A (en) * 1962-10-01 1965-08-31 Xerox Corp Xerographic development apparatus
US3355288A (en) * 1963-11-19 1967-11-28 Australia Res Lab Electrostatic printing method and apparatus
US3806354A (en) * 1969-07-01 1974-04-23 Xerox Corp Method of cyclically developing electrostatic latent images
JPS5010649B1 (fr) * 1970-03-05 1975-04-23
US3933490A (en) * 1971-11-04 1976-01-20 Canon Kabushiki Kaisha Improvements in transfer electrophotography
US3891434A (en) * 1972-12-08 1975-06-24 Herbert Taege Porous material in a liquid development method
US3972718A (en) * 1975-05-19 1976-08-03 Xerox Corporation Electrostatographic gravure member
DE2651427A1 (de) * 1976-11-11 1978-05-18 Agfa Gevaert Ag Elektrofotografisches abbildungsverfahren und aufzeichnungstraeger zur durchfuehrung des verfahrens

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2892708A (en) * 1955-01-03 1959-06-30 Haloid Xerox Inc Xerographic transfer process
CH442992A (de) * 1966-08-19 1967-08-31 Electrostatic Printing Corp Vorrichtung zum elektrostatischen Übertragen eines Pulverbildes
DE1597855A1 (de) * 1966-11-07 1970-08-20 Ibm Elektrostatische Druckvorrichtung
FR2002025A1 (fr) * 1968-02-16 1969-10-03 Eastman Kodak Co
UST869004I4 (en) * 1968-02-16 1969-12-16 For issue date has been scanned, but with missing
DE2821964B2 (de) * 1977-05-20 1980-04-24 Ricoh Co., Ltd., Tokio Verfahren zur Kontaktierung eines Bildempfangsmaterials mit einem Bildträger sowie Übertragungs-Koronavorrichtung zur Durchführung eines solchen Verfahrens
DE3119027A1 (de) * 1980-05-13 1982-03-25 Savin Corp., 10595 Valhalla, N.Y. Elektrofotographisches verfahren und einrichtungen zur durchfuehrung des verfahrens

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0435517A2 (fr) * 1989-12-28 1991-07-03 Am International Incorporated Dispositif et méthode de transfert sur une bande porteuse pour une presse à imprimer électrophotographique
EP0435517A3 (en) * 1989-12-28 1992-04-15 Am International, Inc Carrier web transfer device and method for electrophotographic printing press

Also Published As

Publication number Publication date
EP0052789B1 (fr) 1985-03-27
ATE12432T1 (de) 1985-04-15
DE3043736C2 (de) 1983-11-10
DE3169586D1 (en) 1985-05-02
JPS57114167A (en) 1982-07-15
DE3043736A1 (de) 1982-06-24
US4478924A (en) 1984-10-23
EP0052789A3 (en) 1983-02-09

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