US3622368A - Method for developing electrostatic latent images by utilizing coupling reaction - Google Patents

Method for developing electrostatic latent images by utilizing coupling reaction Download PDF

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Publication number
US3622368A
US3622368A US751758A US3622368DA US3622368A US 3622368 A US3622368 A US 3622368A US 751758 A US751758 A US 751758A US 3622368D A US3622368D A US 3622368DA US 3622368 A US3622368 A US 3622368A
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United States
Prior art keywords
electrostatic latent
compound
charge carrier
diazo compound
electrostatic
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Expired - Lifetime
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US751758A
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English (en)
Inventor
Zenjiro Okuno
Shuuiti Miyabe
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Ricoh Co Ltd
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Ricoh Co Ltd
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Classifications

    • 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
    • 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
    • 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
    • G03G9/09—Colouring agents for toner particles
    • G03G9/0928—Compounds capable to generate colouring agents by chemical reaction
    • 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
    • G03G9/13—Developers with toner particles in liquid developer mixtures characterised by polymer components
    • G03G9/131—Developers with toner particles in liquid developer mixtures characterised by polymer components obtained by reactions only involving carbon-to-carbon unsaturated bonds
    • 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

Definitions

  • a method for developing an electrostatic latent image into a visible image by utilizing a coupling reaction comprising immersing a recording or a copying material such as an electrostatic recording material or an electrophotographic copying material carrying an electrostatic latent image in a liquid developer comprising a carrier liquid consisting of a parafiinic hydrocarbon having a high-electric resistance of not lower than 10 0.
  • the present invention is concerned with a method for developing an electrostatic latent image into a visible image by utilizing the so-called coupling reaction, said method comprising immersing either an electrostatic recording material or an electrophotographic copying material after same has been processed to carry an electrostatic latent image (such a recording or copying material will hereinafter be referred to simply as an electrostatic charge carrier) in a liquid developer containing a diazo compound having a regulated polarity, and thereafter bringing the resulting electrostatic charge carrier into contact with a coupler to thereby form a copied image which bears a desired color.
  • the development of electrostatic latent images has been performed by relying on the following two types of developing methods, one of which is called the wet process development and the other the dry process development.
  • the former of these two types of conventional developing methods comprises immersing an electrophotographic copying material or an electrostatic recording material already carrying an electrostatic latent image thereon in a liquid developer prepared by dispersing a kneaded mixture of particles of a black pigment, such as carbon black, and additives, such as a polarity regulating agent and a dispersing agent, in a carrier liquid having a volume resistance of not lower than 0.. cm.
  • the basic procedure of forming a copied image invariably consisted of depositing, by electrophoresis, the particles of colored pigment onto the area of the electrostatic latent image formed on :1 copying material.
  • these particles of pigment were strictly required to possess the various conditions, i.e. the various physical as well as the chemical properties as well, as being the basic component material constituting the toner, the kinds of colors of the pigment particles were inevitably limited to a very narrow range. Accordingly, the colors of the copied image obtained were limited to only those monotonous tones.
  • the object of the present invention to provide a method for developing an electrostatic latent image to form a so-called colored copied image which may be either in a single color or superimposed synthetic colors or combinations thereof.
  • the present invention concerns a developing method utilizing the so-called coupling reaction between a diazo compound and a coupler. According to the present invention, it is possible to form copied images in a variety of different colors which can be selected from an extensive range of colors.
  • the electrostatic latent image which is developed according to the present invention may consist of any latent image so long as it is one that is formed by an electrostatic charge impressed on an electrostatic charge carrier.
  • the present invention can be applied to all of those electrostatic latent images which are formed by the so-called electrostatic charge impressed on electrostatic charge carriers such as those comprising a photoconductive layer which is provided on a support, or those carriers comprising an insulated layer which is provided on a support, or those carriers which consist of nothing else but insulating materials alone.
  • the present invention permits the use, as the basic material for constituting the toners of the developers, all of those diazo compounds which have been used conventionally as an important component of the lightsensitive layers of the diazo-type copying materials of the prior art.
  • the developer which is used in the present invention is not capable, by nature, of forming a visible image when it is used independently. But, according to the present invention, this developer points to such a solution that is prepared by dispersing-in a carrier liquid consisting of a hydrocarbon having a high electric resistance of not lower than 10 9. cm. and a dielectric constant of not greater than three-any one of the toners selected from the group of toners consisting of the kneaded mixtures of diazo compounds and polarity regulating resins, the kneaded mixtures of diazo compounds, polarity regulating resins and surface active agents and those toners which will be described later in this specification.
  • a diazo compound such as 2,5- dimethoxy-4(4-methylthiophenol) diazonium chloride, 2,5- diethoxy-4(4-methoxybenzoylamide) diazonium chloride and 4N,N-ethylhydroxyethyl diazonium chloride is kneaded with a synthetic resin, such as lauryl methacrylate-acrylamide copolymers, lauryl methacrylate-dimethylaminoethyl methacrylate copolymers and styrene-acrylicester copolymerswhich have been used as the agent for regulating the polarity of the toners of the conventional wet process developers, in the presence of an aromatic solvent or a solvent of petroleum origin such as naphtha.
  • a synthetic resin such as lauryl methacrylate-acrylamide copolymers, lauryl methacrylate-dimethylaminoethyl methacrylate copolymers and styrene-acrylicester
  • developers which are prepared by dispersing the aforesaid kneaded mixtures in carrier liquids consisting of paraffinic hydrocarbons having a volume resistance of not lower than I0 9. cm. and a dielectric constant of not greater than three.
  • those of the aforesaid paraffinic hydrocarbons having the foregoing properties such as ISOPAR H (the trade name of the product manufactured by Esso Standard Oil Company of U.S.A.), ISOPAR G, ISOPAR L (both are the products of the same company), Naphtha No. 6 (t rade name of the product manufactured by Esso Standard Oil Company), are suitable for use in the present invention.
  • halogen-bearing hydrocarbons such as Ereon of E. I. du Pont de Nemours & Co., Inc. of USA. can be used also in the present invention.
  • the developer of the type which is prepared by first mixing a diazo compound with a white fine powder such as silica powder by the use of an appropriate solvent such as water or an organic solvent such as alcohol, kneading the resulting particles-which are in the form that the diazo compound has adsorbed to the particles of the silica powdertogether with an aforesaid polarity regulating agent, and dispersing the kneaded mixture in a carrier liquid.
  • This type of developer is more desirable than the aforesaid developers because, when it is used in the developing process, the copying material on which a copied image is formed through contact with the coupler will have the advantage that the background of the developed copying material is prevented from being soiled.
  • the developer which is prepared by dispersing, in a carrier liquid, a compound formed by chemically introducing a diazonium salt in the phenyl nucleus of styrene contained in a styrene-bearing multiple copolymer and by causing said compound to be adsorbed onto a white fine powder.
  • the introduction of the diazonium compound in the phenyl radical of styrene can be carried out either by the nitration of the styrene polymer or by polymerizing a paraaminostyrene as a copolymeric monomer, and then diazonizing the resulting polymer.
  • the toner which is contained in the developer which can be applied to the present invention may consist of any one of the following group:
  • toners consisting of a mixture of a diazo compound and a polarity regulating agent which consists of a synthetic resin
  • toners prepared by first having a diazo compound adsorbed onto a white fine powder and then kneading the resulting substance together with a polarity regulating agent;
  • c. toners consisting of a compound prepared by chemically uniting a diazo compound to a polarity regulating agent such as a styrene-bearing copolymer;
  • toners consisting of a kneaded mixture of any one of the toners described in (a) through (d) and a surface active agent.
  • the mixing or uniting ratio between the diazo compound and the polarity regulating agent in the foregoing toners is desirably one to 50 parts by weight of the polarity regulating agent relative to one part by weight of the diazo compound.
  • the mixing ratio of the diazo compound to the white fine powder is desirably parts by weight of the white fine powder relative to one part by weight of the diazo compound.
  • those acrylates, other than the aforesaid acrylate copolymers such as the commercially available Plexrol 996 (the trade name of the product of Rhorn & Hass Co. of U.S.A., which is a nitrogen-bearing polymer), alkyd resins, polymers linseed oil and rosin are desirable also.
  • couplers which are adapted to form azo dyes by uniting to the aforesaid toners containing diazo compounds, there are those which produce blue dyes and which include 2,3- hydroxynaphthalene, 2-hydroxy-3,6-disulfonic acid and 2- amino-S-hydroxynaphthalene-7-sulfonic acid monourea, and there are those which form red dyes and which include 3- methylphrazolone, 3,5-diethoxyphenol, l,3,5resorcinic acid anilide, 5,5-dimethyl-l,3-cyclohexanediene and l-p-sulfophenyl-3-methyl-5-pyrazolone, and still there are those which form yellow dyes and which include acetoacetoanilde, 2,5-dimethyl-4-morpholinomethylphenol, l-methyl-3hydroxy-4-acetoamidebenzene and 2-hydroxy-4-methylphenyl.
  • couplers which form violet dyes include, other than the couplers employed in the examples which will be described later, 3-acetoacidphenol, 3-(aimnophenylsulfonylamino)- phenol, 2-(3-aminobenzeneamide)-7-naphthol and 7-hydroxynaphthalene-l-biguanidine-HCl.
  • couplers there are resorcin (which form a brown dye), lphenyl-3-methyldiazole (which forms an orange dye), phloroglucin (reddish violet dye), monohydroxethylether of catecol (yellowish brown dye), phloroglucide (violet black dye) and 2,3-dihydroxynaphthalene monoglycollic acid either (blue black dye).
  • an electrostatic charge carrier (a carrier of an electrostatic image)which consists of an electrophotographic copying material having been processed in such a way that, after is it impressed with the positive or the negative charge by a known method, it is exposed to light rays through a negative or a positive original or which consists of an electrostatic recording material having been impressed directly with an electrostatic latent image-is immersed in a developer as those described above, so that, as the result, the toner which comprises a diazo compound is deposited, by electrophoresis, onto the area of the electrostatic latent image formed on said an electrostatic charge carrier such as copying or recording material, and then the resulting electrostatic charge carrier is either immersed in an alkaline solution containing an appropriate coupler elected from the aforesaid group and being capable of forming a dye of a desired color through its reaction with the aforesaid diazo compound, or is brought into contact with the vapor of a sublimable coupler such as resorc
  • a dye according to the present invention is performed by relying on any one of the aforesaid roughly divided two types of color developing procedures. in case, however, the procedure of color developments relies on the use of said solution, it is desirable to perform this color development after coating the color-developing face of the copying or the recording material with a thin film ofa synthetic resin in order to avoid the dissolution of the diazo compound which has been electrically deposited on the area of the electrostatic latent image formed on the electrostatic charge carrier into the solution containing said coupler.
  • the employment of a solution of an organic solvent, such as toluene and acetone, which contains, in the form of being dissolved therein, any one of the following substances selected from the group consisting of acrylates such as methyl methacrylate, cellulose derivatives such as cellulose acetate, styrene and its copolymers is desirable.
  • the resulting carrier is again charged and exposed to light rays through the original and through a bluish green filter and thereafter it is brought into contact with the developer, followed by the formation of the region of the red copies image by the use of 3-methylpyrezolone
  • the carrier which has undergone the foregoing two steps of color development is subjected to a similar series of procedures, i.e. charging--exposure to light (using a blue filter)bringing into contact with the developer-formation of the region of the yellow copied image by the employment of acetoacetoanilide.
  • acetoacetoanilide As a result, a colored copied image is obtained.
  • the developing method of the present invention not only is there obtained a copied image bearing colors of a very wide range, but also is there provided an advantage that the copied image is of a satisfactory clarity.
  • the developing method of the present inven tion is indeed epoch-making.
  • Plexrol 996 the trade name of the product of Rhom and Hass Co., a nitrogen-bearing polymer
  • 2gr of the resulting mixture was dispersed in 300cc. of an isoparaffinic hydrocarbon (a product manufactured and sold under the trade name of lSOPHAR H by Esso Standard Oil Company), and thus a developer containing a toner comprising a diazo compound and having a polarity regulated to the negative charge was prepared.
  • the resulting copying material After having impressed a commercial electrophotographic copying material (whose photoconductive layer was comprised of zinc oxide and a synthetic resin) with a negative charge by known corona discharge, the resulting copying material was exposed to light rays coming from a tungsten lamp through a negative original to thereby form an electrostatic latent image thereon. Thereafter, the resulting copying material was immersed in the aforesaid developer for lseconds. As a result, the diazo compound was deposited electrically on the area of the electrostatic latent image, and thus a copying material on which a light yellow positive copied image was formed was obtained.
  • EXAMPLE 2 3.0 gr. of a diazo compound which consisted of 2,3 diethoxy- 4(4'-methoxybenzoyamide) diazonium chloride expressed by the general fonnula:
  • EXAMPLE 3 Onto the face of the copying material obtained in example 2 and carrying a light yellow positive copied image formed by the electric deposition of the diazo compound was lightly sprayed a 3percent methylmethacrylate/toluene solution by a spray gun to form a coat thereover. Thereafter, the resulting copying machine was brought into contact with phloroglucin vapor. Thus, a beautiful dark violet positive copied image which was free of soiled background was obtained.
  • EXAMPLE 4 1.2 gr. of a diazo compound which consisted of 2,3- dimethoxy-4(4'-methylthiophenol)- diazonium chloride, 1.2 gr. of fine silica powder and cc. of methanol were mixed together in a ball mill. Thereafter, the resulting mixture was subjected to suction filtering in darkness. The residue of the filtering was dried under a reduced pressure. Thus, a white powder of the type that the diazo compound was adsorbed onto the fine silica powder was prepared. 2.4 gr. of this powder, 1.2 gr. of a resin consisting of a lauryl methacrylatedimethylaminoethyl methacrylate (9: l), 2 cc.
  • EXAMPLE 5 ogr. of para-aminostyrene and 135 gr. of butyl methacrylate made into the form of suspended fine particles. While keeping this suspension at 0 C, a mixture of 0.05 mole of sodium nitrite and 0.05 mole of hydrochloric acid was introduced therein during 2 hours. By filtering out the resulting substance,
  • para-diazostyrene-para-aminostyrene-butylmethacrylate copolymer (a 23percent diazonified relative to the amino radical) was obtained. Under a reduced pressure, this copolymer was dried at normal temperature. and as a result, a yellowish brown powder was obtained.
  • a method for developing an electrostatic image comprising the steps of:
  • said azocoupling compound is selected from the group consisting of acetoaceto-anilide, l-phenyl- S-methyldiazole, resorcin and phloroglucin, and said azo-coupling compound is brought into contact with said electrostatic charge carrier in order to form said visible image.
  • said diazonium compound is selected from the group consisting of 2,5 dimethoxy-4-(4-methylthiophenol) -benzene diazonium chloride, 2,5-di-ethoxy-4-(4-methoxybenzoylamide) benzene diazonium chloride and 4-N,N-ethylhydroxyethyl benzene diazonium chloride.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Developing Agents For Electrophotography (AREA)
US751758A 1967-08-22 1968-08-12 Method for developing electrostatic latent images by utilizing coupling reaction Expired - Lifetime US3622368A (en)

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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3849132A (en) * 1973-01-04 1974-11-19 Xerox Corp Photoelectrophoretic imaging method employing a chromogenic reaction
US3870644A (en) * 1969-02-10 1975-03-11 Ricoh Kk Liquid developer for plural-color electrophotography
US3887373A (en) * 1973-04-11 1975-06-03 Motorola Inc Non-polluting photoresist developing process
US4193794A (en) * 1973-04-02 1980-03-18 The Commonwealth Of Australia Liquid developers for electrostatic images

Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2597306A (en) * 1949-10-05 1952-05-20 Little Inc A Printing process wherein an alkaline substance passing through stencil openings effects coupling of an azo dye in situ
US2877133A (en) * 1956-10-22 1959-03-10 Gen Dynamics Corp Electrostatic photography
US3083117A (en) * 1957-06-14 1963-03-26 Schmiedel Ulrich Process of developing electrostatic images
US3157546A (en) * 1960-04-19 1964-11-17 Xerox Corp Image transfer
US3253913A (en) * 1960-10-13 1966-05-31 Eastman Kodak Co Process for color electrophotography
US3259581A (en) * 1961-11-23 1966-07-05 Australia Res Lab Liquid developer for electrostatic images
US3272644A (en) * 1963-07-31 1966-09-13 Dennison Mfg Co Development of latent electrostatic images with crystalline toners
US3285741A (en) * 1961-04-19 1966-11-15 Agfa Gevaert Nv Process for developing electrostatic latent images
US3373109A (en) * 1963-10-29 1968-03-12 Mobil Oil Corp Crystalline aluminosilicate catalyst
US3376133A (en) * 1964-11-25 1968-04-02 Interchem Corp Multicolor electrostatic printing
US3417019A (en) * 1962-12-27 1968-12-17 Eastman Kodak Co Xerographic development

Patent Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2597306A (en) * 1949-10-05 1952-05-20 Little Inc A Printing process wherein an alkaline substance passing through stencil openings effects coupling of an azo dye in situ
US2877133A (en) * 1956-10-22 1959-03-10 Gen Dynamics Corp Electrostatic photography
US3083117A (en) * 1957-06-14 1963-03-26 Schmiedel Ulrich Process of developing electrostatic images
US3157546A (en) * 1960-04-19 1964-11-17 Xerox Corp Image transfer
US3253913A (en) * 1960-10-13 1966-05-31 Eastman Kodak Co Process for color electrophotography
US3285741A (en) * 1961-04-19 1966-11-15 Agfa Gevaert Nv Process for developing electrostatic latent images
US3259581A (en) * 1961-11-23 1966-07-05 Australia Res Lab Liquid developer for electrostatic images
US3417019A (en) * 1962-12-27 1968-12-17 Eastman Kodak Co Xerographic development
US3272644A (en) * 1963-07-31 1966-09-13 Dennison Mfg Co Development of latent electrostatic images with crystalline toners
US3373109A (en) * 1963-10-29 1968-03-12 Mobil Oil Corp Crystalline aluminosilicate catalyst
US3376133A (en) * 1964-11-25 1968-04-02 Interchem Corp Multicolor electrostatic printing

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
Dinaburg, M. S., Photosensitive Diazo Compounds and their Uses Focal Press translated from a 1964 Russian book, page 58. *

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3870644A (en) * 1969-02-10 1975-03-11 Ricoh Kk Liquid developer for plural-color electrophotography
US3849132A (en) * 1973-01-04 1974-11-19 Xerox Corp Photoelectrophoretic imaging method employing a chromogenic reaction
US4193794A (en) * 1973-04-02 1980-03-18 The Commonwealth Of Australia Liquid developers for electrostatic images
US3887373A (en) * 1973-04-11 1975-06-03 Motorola Inc Non-polluting photoresist developing process

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Publication number Publication date
DE1797150A1 (de) 1971-04-15
BE719798A (enExample) 1969-02-03
DE1797150B2 (de) 1978-01-26

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