US3785983A - Method of producing a liquid developer for use in the electronic photography - Google Patents

Method of producing a liquid developer for use in the electronic photography Download PDF

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Publication number
US3785983A
US3785983A US00203543A US20354371A US3785983A US 3785983 A US3785983 A US 3785983A US 00203543 A US00203543 A US 00203543A US 20354371 A US20354371 A US 20354371A US 3785983 A US3785983 A US 3785983A
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United States
Prior art keywords
developer
liquid
soap
developer liquid
carbon black
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
US00203543A
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English (en)
Inventor
M Inoue
K Nagai
S Kitaguchi
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Minolta Co Ltd
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Minolta Co Ltd
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Publication date
Priority claimed from JP45105938A external-priority patent/JPS4946950B1/ja
Priority claimed from JP46072532A external-priority patent/JPS4839036A/ja
Application filed by Minolta Co Ltd filed Critical Minolta Co Ltd
Application granted granted Critical
Publication of US3785983A publication Critical patent/US3785983A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G9/00—Developers
    • G03G9/08—Developers with toner particles
    • G03G9/12—Developers with toner particles in liquid developer mixtures
    • G03G9/122—Developers with toner particles in liquid developer mixtures characterised by the colouring agents
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G9/00—Developers
    • G03G9/08—Developers with toner particles
    • G03G9/12—Developers with toner particles in liquid developer mixtures
    • G03G9/135—Developers with toner particles in liquid developer mixtures characterised by stabiliser or charge-controlling agents
    • G03G9/1355—Ionic, organic compounds

Definitions

  • the potential of the transferred electrostatic image is desg g fi ai gfi gg g Mmolta Camera Kabushlkl creased to the level of one-tenth thereof, that is, usually Filed a 5 Sen No. 203,543 it is lowered to the low potential of the order from 60 Claims priority, application Japan, Dec. 2, 1970, volts to 150 45/105,938 I Consequently, If a liquid developer for use In the de- Im, C G03 9/04 10 velopment of an electrostatic image having a high poten- US. Cl. 252-621 7 Claims tial of the degree from 250 volts to 400 volts formed on a photosensitive sheet is put to use against an electrostatic having such a low potential.
  • Such a carbon fi image transfer type has been a liquid developer which is the llke an aqueouS Solutlon 0f Sald 1 substltutlng appropriate for developing electrostatic charges of a low alkalflne g 5 saidhsoap 0n lp g P potential and endowed with an excellent electric charge 1c e sur ace wit meta 1c lOl'lS aving a va ance o 2 or responsivity more them Precipitated, treating this precipitate While, in order to obtain a stable developer liquid by y Washlng and drying it after l g it Out therefronrso making use of this carbon black, a dispersing agent and a Rrodllce
  • the toner particle thereof is comprised of a Property either lmeadable wlth the.dlspersmg medlum.or' core of the coloring fine grain and an extremely thin adpufiafle therewlth W as capable of bgmg.
  • the dlsparsmg l F adsorption of additives such as a resin and the like to be carbon g i fi by s ashdescnbgd functional as a charging control agent, a dispersing agent a mg a e amoln ⁇ e ec me w j n and a fixing agent for the purpose of providing the OF the carbon black can be stabillilzed as well as addrtilve ganic liquid with the chargeability, the dispersivity and S fg q g :fi g R i the fixability.
  • a chars charged polarity of the particles is uniform and that the mg coplrol agent a dlspersmg agent and a fixing-agent amount of the electric charge there to is capable of being as addltlves are allowedto 2 anyway adsorbed'umform' magnified in the case of the Carlson type and of being ly on the carbon black particles, and that the amount of lessened in the case of the electrostatic latent image trans- Qharges 18 W adlusted I fer type as well as capable of being kept Stable at all It is in general difiicult to quantitat vely treat the times amount of electric charges of toner particles, however, In case Where a carbon black is put to use as the if it is considered on the basis of the analysis whichjis coloring fine grains, it has ben remarkably diflicult that a heretofore cameid It can be assllmed l the-Tide?
  • latent Image graphy is produced by dispersing the carbon black with vlrtue 9 hquld deyeloper 1S substzfmtlally Va prose-S519" fine grains in a dielectric liquid, because that the oil abneutral? the .elecmc charge formmg the electrostatlc sorptive property of the carbon black is remarkable on W Image Wlth the.ele.cmc charges of the toner account of its porosity, and that the chemical property @168 111 the loper liquid.
  • I v I of fine grains of the carbon black is varied depending on Based the conslderatlon i b q P the production method thereof and according to the quist and hls company have studied the variation affected ameter of each grain. to the property of a toner by the: relation between the 7 amount of electric charges of an electrostatic latent image; I;
  • n Number of electric charges per one toner.
  • FIG. 1 is a graphic diagram showing the development characteristics of the relationship between the surface potential of an electrostatic latent image and the development density at which said electrostatic latent imageis developed by virtue of a developer liquid.
  • the present invention is disclosed on the basis of the viewpoint as described hereinabove. More specifically, the disclosure utilizes the fact that a carbon black is of the pH value of less than 8 in its aqueous solutions almost all of which are acidic, and that it is remarkably dispersible in an aqueous solution of an alkaline soap, and the carbon black is accordingly treated with a metallic salt the carbon particles are substituted by 2 kinds of metallic ions having a valence of 2 or more so as to produce the so called metallic soap. Since the carbon particles treated as described above are precipitated in the solution, the precipitated particles are taken out therefrom, washed with clean water and then dried out.
  • the carbon black treated as above is further mixed with a dielectric macromolecular material added thereto, said material being of a property kneadable and puifable with the dispersing liquid, or else the surface thereof is coated with said mixture, and thereafter it is dispersed in the dielectric, aliphatic petroleum hydrocarbon.
  • the dispersion thereof can be easily carried out and remarkably stabilized so that its polarity of electric charges is uniform and stable, accordingly obtained is a colloidal developer for use in the electronic photography, said developer being of the positive polarity and having an excellent electric charge responsivity.
  • the quantity of the unsaturated fatty acid to be added with respect to the carbon black is not necessarily the more the better, and its appropriate amount is less than 20% of the oil absorptive quantity of the carbon black.
  • the unsaturated fatty acids appropriate to put to use therefore are oleic acid, linolic acid, linolenic acid and the like.
  • said unsaturated fatty acid may be incorporated with an oil carrier material to present an oil composition wherein the total amount of the fatty acid included is more than 50% of the composition.
  • Suitable oils include vegetable oils such as linseed oil, tung oil, perilla oil, sesame oil, soybean oil, etc., or animal oils such as lard, or the like.
  • the materials having a valent state of 2 or more for producing metallic salts with the unsaturated fatty acids as shown above are appropriately selected frlpm among Ba, Ca, Mg, Al, Pb, Zn, Ni, Co, and the li e.
  • the diagram shown in FIG. 1 is the measured result of the values of dD/dq for the developer liquid obtained by the producing method in accordance with the present invention as described hereinabove, and the values are compared therein with those measured for some prior developer liquid being sold in the market.
  • FIG. 1 illustrates the development density characteristics showing the relationship between the surface potential of an electrostatic transfer sheet charged by means of a corona discharge unit and the development density on said transfer sheet after the sheet has been developed by various developer liquid for a period of one minute.
  • the curve A is the development density shown by a developer liquid which is perhaps sold in any market and is represented by the general use developer of the Mitsubishi Seishi Co., Ltd. If a transfer sheet of which the charged surface potential is around volts is developed by said developer liquid, the development density obtained thereby is, as seen in FIG. 1, very weak and its value is less than 1.0, resulting that it can not be put to use in a practical development of a transfer sheet having a low surface potential.
  • the curve B shows the development density characteristics of a developer liquid which is rarely sold in the market and represented by the linework use developer liquid of the Mitsubishi Seishi Co., Ltd.
  • This developer liquid shows the best electric charge responsivity among those of every developer liquids presently sold in the market, and therefore it may be possibly put to use for the low potential too.
  • any developer liquid is generally capable of maintaining its continuous developing operation under the intermittent supply of a condensed toner, and if the developer liquid is continuously kept in its developing operation like this, its development density is gradually degraded down to the degree of about one-half as much as the initial density thereof at the time when nearly 700 sheets have been developed, therefore,
  • the curve C shows the development density characteristics of the developer liquid in accordance with the present invention, and the electric charge responsivity thereof is remarkably improved in comparison with those described above, therefore, this developer liquid is endowed with various advantageous properties which will be described hereinafter as the embodiments thereof shown in the Examples No. 11 through No. 15.
  • An oleic acid of 20 g. is saponified with a caustic soda (NaOI-I) of 8 g. so as to completely produce a soap, thereafter said soap is taken out therefrom and added with clean water up to its volume of 500 cc., then it is heated to be fully dissolved until it is made upinto an aqueous soap.
  • the 0.5 g. part of the powder thus obtained is thereafter dispersed by the supersonic process in the Isopar G (trade name by the Esso Standard Petroleum Co.) with its volume of 500 cc., a novel developer liquid being thus obtained.
  • a 10 g. weight of the powder obtained in the Example No. 1 and 10 g. weight of an ethyl cellulose are together dissolved in a xylene of 50 cc. and mixed completely by means of a high speed mixer.
  • a solid type paraffin of 10 g. weight is heated and dissolved in the Isopar G of 100 cc., and this solution is added little by little into the previously produced mixture, while the mixture is agitated, and it is fully mixed therewith.
  • the Isopar G is then added into this mixed solution so as to make up a condensed developer liquid until its total volume is brought up to 500 cc.
  • a novel developer liquid is produced by diluting this condensed developer liquid of 10 cc.
  • a 10 g. weight of the powder obtained in the Example No. 1 and a g. weight of an alkyd resin are together dissolved in a xylene of 50 cc. and mixed completely by means of a high speed mixer, and thereafter the mixture is treated in the same way as done in the Example No. 9. 7
  • Example No. 11 through No. 15 are each an embodiment of the developed liquid in accordance with the present invention for use in the development of a latent image transfer sheet, said developer liquid being endowed with the excellent electric charge responsitivity.
  • An oleic acid of 25 cc. is saponified with a caustic potash (KOH) until they make up a soap completely, thereafter, the soap is taken out therefrom and added with clean water until its volume is brought up to 1000 cc., then the mixture is heated to permit the soap to be completely dissolved therein, an aqueous soap solution being thus obtained.
  • the carbon black dispersed liquid is put in a homomixer, and while it is being agitated therein by a high revolution thereof, a mixed solution of a barium acetate of 9.2 g. weight and a calcium acetate of 12.8 g. weight is added thereinto so as to produce a precipitate therein.
  • the precipitate is taken out therefrom by filtering off, and fully washed out with clean water, thereafter it is vacuum dried at the temperature of about C. so as to completely remove moisture therefrom.
  • a 30 g. weight of the treated carbon powder obtained by the process aforementioned is mixed with a 12 g. weight of an alkyd resin (can be procured under the trade name Aroplaz No. 6008 by its manufacturer of the Nisshoke Aro Chemical Co., Ltd), a 20 g. weight of a toluene and a 40 g. weight of Isopar H (trade name by its manufacturer of the Esso Standard Petroleum Co.), and this mixture is perfectly dispersed by the ball mill means for a period of about 24 hours.
  • an alkyd resin can be procured under the trade name Aroplaz No. 6008 by its manufacturer of the Nisshoke Aro Chemical Co., Ltd
  • a 20 g. weight of a toluene and a 40 g. weight of Isopar H (trade name by its manufacturer of the Esso Standard Petroleum Co.)
  • this mixture is perfectly dispersed by the ball mill means for a period of about 24 hours.
  • the mixture thus obtained is again dispersed in Isopar L (trade name by its manufacturer of the Esso Standard PetroleumCo.) of 400 cc. by means of a homomixer so as to make up a condensed toner liquid.
  • Isopar L trade name by its manufacturer of the Esso Standard PetroleumCo.
  • Isopar G trade name by its manufacturer the Esso Standard Petroleum Co.
  • a novel developer liquid obtained by treating the thus produced powder in the same way as described in the Example No. 11 is endowed with the stable electric charge polarity identical with the developer liquid shown in the Example No. 11, and the development characteristic thereof is also approximately identical with that of the Example No. 11.
  • any developer liquid produced in accordance with the present invention for use in the development of electronic photographs is endowed with an excellent dispersivity and stability, as well as the electric charge characteristics thereof is remarkably stable and the electric charge responsitivity in the development characteristics thereof is also good, consequently, it is functionally effective in that it is capable of developing an electrostatic image speedily, so as to obtain a picture image of which the contrast is good and half tones are reproduced with fidelity, even though the surface potential of said image is comparatively low as that of an electrostatic image transferred electrostatically onto not only a transfer sheet but also a photosensitive sheet of the Carlson type.
  • a method for producing a developer useful for de veloping latent electrostatic images said method com prising:
  • a saponifiable fatty acid material including at least about 50%, based on the total quantity of said material, of a saponifiable, unsaturated fatty acid
  • a method a set forth in claim 1 wherein said pigment material comprises carbon black.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Liquid Developers In Electrophotography (AREA)
US00203543A 1970-12-02 1971-12-01 Method of producing a liquid developer for use in the electronic photography Expired - Lifetime US3785983A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP45105938A JPS4946950B1 (de) 1970-12-02 1970-12-02
JP46072532A JPS4839036A (de) 1971-09-20 1971-09-20

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US3785983A true US3785983A (en) 1974-01-15

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1980002222A1 (en) * 1979-04-11 1980-10-16 Neselco As A method for drysensitization of an insulating surface and a powder for use with the method
WO2013178268A1 (en) * 2012-05-31 2013-12-05 Hewlett-Packard Indigo B.V Electrostatic inks and method for their production

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1980002222A1 (en) * 1979-04-11 1980-10-16 Neselco As A method for drysensitization of an insulating surface and a powder for use with the method
WO2013178268A1 (en) * 2012-05-31 2013-12-05 Hewlett-Packard Indigo B.V Electrostatic inks and method for their production
US9745488B2 (en) 2012-05-31 2017-08-29 Hewlett-Packard Indigo B.V. Electrostatic inks and method for their production

Also Published As

Publication number Publication date
DE2159467A1 (de) 1972-07-13

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