US3679586A - Liquid electrophotographic developers containing a dye modified polypeptide - Google Patents

Liquid electrophotographic developers containing a dye modified polypeptide Download PDF

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Publication number
US3679586A
US3679586A US64826A US3679586DA US3679586A US 3679586 A US3679586 A US 3679586A US 64826 A US64826 A US 64826A US 3679586D A US3679586D A US 3679586DA US 3679586 A US3679586 A US 3679586A
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United States
Prior art keywords
polypeptide
toner
liquid
dye
developer
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Expired - Lifetime
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US64826A
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English (en)
Inventor
Satoru Honio
Yasuo Tamai
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Fujifilm Holdings Corp
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Fuji Photo Film Co Ltd
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2/00—Processes or devices for granulating materials, e.g. fertilisers in general; Rendering particulate materials free flowing in general, e.g. making them hydrophobic
    • B01J2/02—Processes or devices for granulating materials, e.g. fertilisers in general; Rendering particulate materials free flowing in general, e.g. making them hydrophobic by dividing the liquid material into drops, e.g. by spraying, and solidifying the drops
    • B01J2/06—Processes or devices for granulating materials, e.g. fertilisers in general; Rendering particulate materials free flowing in general, e.g. making them hydrophobic by dividing the liquid material into drops, e.g. by spraying, and solidifying the drops in a liquid medium
    • B01J2/08—Gelation of a colloidal solution
    • 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

Definitions

  • This invention relates to a new electrophotographic liquid developer which is especially suited for reproduction of multicolored imagesJFurthel', it relates to a developer which exhibits complete color mixing when used in over-print multicolor development and which has improved spectral absorption characteristics.
  • Electrophotographic process is widely used to produce visible image informations, referred to as electrophotography or xerography, in which the most prevailing system in photocopy use comprises the following operations.
  • a photoconductive layer coated on a more or less electrically conductive support is imparted a uniform surface charge in subdued light, and then subjected to image exposure by means of suitable radiation energy source modulated irnagewisely, whereby the surface charge is Y discharged in proportion to radiation intensity.
  • suitable radiation energy source modulated irnagewisely whereby the surface charge is Y discharged in proportion to radiation intensity.
  • an electrostatic surface pattern results on the photoconductive layer having a charge density distribution inversely proportional to the amount of exposure. That is, the strongly irradiated area of the photoconductive layer holds a low residual charge density, while we'akly irradiated area retains a relatively high charge density.
  • electrostatic latent image is converted visible by developing technique well known in the field of xerography.
  • a most common operation of development comprises applying a finely-divided developing powder or toner onto the exposed layer.
  • the toner deposits in accordance with the charge density distribution on the latent image thus forming a visible image.
  • a variety of development techniques are carried out according to requirement to final images.
  • a toner which is made to assume a charge of an opposite polarity to the latent image to be developed accomplishes positive to positive reproduction'by virtue of coulomb attraction.
  • a toner having the same polarity of charge may be employed whereby the toner deposits on discharged area in the latent image thus realizing negative to positive reproduction.
  • the latter process is sometimes referred to as repulsion or reversal development and forms a visible image optically inverted to the one obtained by attraction development.
  • the inventors have developed a new type of developer overcoming the above mentioned deficiencies as a result of investigation on the possibility of producing developers with materials quite different from those of conventional developers.
  • the object of the present invention is to provide a new type of liquid developer having new composition and improved properties.
  • Another object is to provide liquid developers capable of accurate reproduction of color. in over-printing electrophotographic process.
  • Still another object is to disclose a new method of preparing a new type of liquid developer.
  • I Liquid developers of the present invention are characterized by that they comprise a highly electrically insulating carrier liquid and finely-divided toner dispersed therein comprising originally water soluble polypeptide, the hydroxyl and/ or amino radicals of which are reacted with reactive dyestufis.
  • the present invention is based on the development of new technique which has made it possible to disperse with high stability polypeptide particles such as gelatin, glue, casein, albumine, etc. in nonpolar insulating liquids.
  • This invention has its primary importance in utilization of reactive dyes in conjunction with this new technique.
  • the toner in the developer prepared in accordance with the present invention is dye-connected polypeptide, and the dye molecules are dispersed in the polymer in molecular order thus providing the toner with perfect clarity far better than that of pigment based toners.
  • Any types of polypeptide may be used for the present purpose provided that they contain hydroxyl and/or amino radicals which can enter into chemical reaction with reactive dyes and that they are soluble in water or strongly hydrophilic.
  • Typical examples include gelatin, glue, casein, albumen, etc. and their derivatives such as phthalated gelatin.
  • a black or grey toner can be prepared by utilizing two or more differently colored dyes, or by mixing two or more kinds oftoner each of which includes a dilferently colored .dye.-
  • the solvent system for reaction may comprise solely of water or contain water-miscible organic solvents such as alcohols, ketones, Cellosolves, etc., among which acetone is preferred as regards the feasibility of liquid developer preparation.
  • the content of organic solvents ordinarily falls in the range from 10 to 20%.
  • a gell or sol of a polypeptide united with a reactive dye, which will be referred to as dyed polypeptide for simplicity, is adequately diluted with water or a mixture of water and an organic solvent.
  • the amount of the organic solvent is limited so as not to cause the precipitation of the dyes polypeptide.
  • the diluted sol is thrown into an excessive amount of water-miscible organic solvent under vigorous stirring forexample by means of polypeptide.
  • This mixture forms a clear solution when heated at 25 C.
  • -It is possible to obtain a fine powder of a dyed polypeptide by adding directly an aqueous solution of, the polypeptide into an organic solvent which is a nonsolvent for said polypeptide, but such a process is prone to bring about coagulation of the polypeptide. Coagulation can be prevented by simultaneously adding a nonpolar organic solvent solution of a resinous material which also becomes insoluble in the resulting mixture.
  • the nonpolar solvent to be used must be compatible with the polar solvent employed to insolubilize the polypeptide.
  • nonpolar solvents include cyclohexane, Decalin,
  • dissolved one or more of the following resins which are insoluble in polar solvents such as acetone or methanol; polyisobutylene, polybutene, polystyrene, styrenebutadiene copolymer, rosin modified phenol-formaldehyde resin, etc.
  • a prominent feature of this coprecipitation method lies in that it enables formation of an extremely fine toner as well as perfect removal of residual water content in the polypeptide.
  • the supernatant liquid may be removed by either decantation or centrifugal separation.
  • the precipitate usually includes a polypeptide powder of less than 1 micron, and the size of the powder does not tend to grow during a prolonged storage.
  • PREPARATION F A LIQUID DEVELOPER
  • the precipitate including a finely divided dyed polypeptide is repeatedly purified by washing to remove inorganic ingredients and residual water. Then it is added to a nonpolar organic solvent which plays a roll of carrier liquid for the liquid developer whereby the resin in the precipitate dissolves in the solvent, releasing the dyed polypeptide in the solvent in the form of fine particles.
  • part of the resin seems to be adsorbed on the surface of the polypeptide particles to stabilize colloidal dispersion. Therefore no intense stirring operation is necessary at this process.
  • Cyclohexane, Tetralin, Decalin, and kerosene are among suitable carrier liquid; isoparaflinic and fluorinated hydrocarbons which have a far weak solving power are less suited since they cannot dissolve many of abovementioned resins.
  • Organic liquids which have solubility parameters greater than 7.0 and about 8.8 at room temperature or Kauribitanol values of from 26 to 85 are suited for carrier liquid.
  • a minor amount of more powerful solvents such as aromatic hydrocarbons or ketones may be added to those solvents, the upper limit of addition being about 5 parts in 100 parts of the total carrier liquid.
  • Mixed solvent systems may also be used provided that the solubility parameters for the systems fall in the above mentioned range.
  • the carrier liquid phase of a developer prepared in the described manner therefore comprises a non-polar organic liquid and a resinous component dissolved in said liquid, and the liquid phase should desirably have an electrical resistance not lower than ohms-cm. not to cause destruction of an electrostatic latent image.
  • developers of the present invention may resort to a technique in which particles having a strong tendency of acquiring a charge of desired polarity are added to the developer.
  • developers of either polarity, positive or negative are possible depending on the amount and the nature of the particles to be added.
  • Materials used to prepare positively charged particles include ethyl cellulose, hydroxyethyl cellulose, polymethacrylates, etc., while resinous materials which acquire negative charges in insulating liquids are copolymers containing vinyl chloride, nitrocellulose, polyvinylidene fluoride, etc.
  • Liquid developers of the present invention offers another advantage that the resulting toner images would not accept a high electrical potential because of the extremely hydrophilic nature of the principal ingredients. This means that in the over-printing electrophotographic process, whereby charging of the developed image at the subsequent charging is not desirable, the present developers are especially suited, not permitting undesirable deposition of toner on the already developed area.
  • EXAMPLE I 5 g. of gelatin was dissolved in 20 ml. of Water by heating after being allowed to swell. A reactive dye solution was prepared by dissolving 200 mg. of Remazol Brilliant Violet (Hoechst) in 2 ml. of water.
  • Hoechst Remazol Brilliant Violet
  • a solution was prepared comprising g. of toluol, 10 g. of linseed oil, and 15 g. of resin modified phenolformaldehyde resin, which is soluble in toluol or cyclohexane and not in acetone.
  • This solution and the gelatin solution prepared above were simultaneously added into 320 g. of acetone whereby a precipitate resulted.
  • the precipitate was separated by means of centrifuge and further washed with acetone.
  • the obtained pasty precipitate was dispersed in 400 ml. of cyclohexane.
  • the dyed gelatin particles in the dispersion proved to be positively charged and thus to undergo an attractive deposition on an electrostatic latent image of negative polarity.
  • the appearance of a developed image was deep magenta.
  • EXAMPLE II A dyed gelatin gel was prepared in the same procedure as was described in the foregoing example except that Remazol Brilliant Violet purchased from ICI was replaced to Procion Brilliant Red H-3BS.
  • EXAMPLE IV 1 g. of soya bean casein was dissolved in 5 g. of water together with a slight amount of sodium carbonate then 20 mg. of Reactone Navy Blue GRL was dissolved. This mixture was heated at C. for 15 minutes. After cooling, 5 ml. of methanol was added.
  • a second solution was prepared by dissolving 10 g. of linseed oil and 15 g. of rosin modified phenol-formaldehyde resin in 80 g. of toluol. To 300 g. of acetone were added dropwise these two solutions to obtain a colored precipitate. The precipitate was taken -7 out by a centrifuge, and the supernatant liquid was re placed by acetone. After washing, the paste was dispersed in 400 ml. of cyclohexane. A satisfactory liquid developer for electrophotography resulted.
  • a liquid developer containing a toner of negative polarity was prepared by adding to 40 parts of the developer prepared in Example II 60 parts of a dispersion comprising a finely-divided (particle size 0.3 micron) vinyl chloride/vinyl acetate copolymer dispersed in cyclohexane.
  • EXAMPLE VI A black toner containing developer was obtained by following the procedure of Example I with the use of Cibacron Black RP of Ciba Ltd. in place of Remazol.
  • An electrophotographic liquid developer comprising a highly insulating non-polar carrier liquidand a toner dispersed therein, said toner comprising finely divided particles of the reaction product of about 100 parts by weight of a hydrophilic polypeptide and about 0.1 to 20 parts by weight of a reactive dye containing both an electron aflinitive functional group capable of reacting with the NH, or OH groups of said polypeptide and a chromogenic group exhibiting an optical absorption in the visible region of the spectrum.
  • Method of forming a liquid developer comprising a highly insulating, non-polar carrier liquid and a toner dispersed therein, said toner comprising a reactive dyemodified polypeptide compound group consisting of gelatin, casein, albumen and glue, said polypeptide being chemically united with a reactive dye containing both an electron afiinitive functional group capable of reacting with NH, or OH .group in a hydrophilic polypeptide compound and a chromogenic group exhibiting an optical absorption in the visible region of the spectrum, which comprises the steps of p (1) dispersing in an organic solvent which is-miscible with water but is a non-solvent for the reactive dye modified polypeptide, an aqueous solution of said modified polypeptide or a solution of said polypeptide in a mixed solvent of water and an-alcohol prepared by incorporating in the aqueous solution of said polypeptide an alcohol in an amount which causes no precipitation of said polypeptide to provide a dispersion of said polypeptide
  • step (2) peptide a solution of a resin which is insoluble in the 5 i J. P. BRAMMER, Assistant Examiner organic solvent for said polypeptide dispersion but soluble in a carrier liquid havingan electric resisttance of higher than 10 ohm-cm. to coprecipitate the said polypeptide grains and the resin; and (3) adding the precipitates of said polypeptide grains and the resin to the carrier liquid mentioned above.
  • said resin used in step (2) is polyisobutylene resin, polybutene resin, styrene resin, styrene-butadiene copolymer 0 resin-modified phenol-formaldehyde resin.
  • polypeptide compounds is selected from the group consisting of gelatin, casein, albumen, and glue.
  • polypeptide compound is gelatin and where 0.1 to 20 parts by weight of said reactive dye are chemically united with parts by weight of said gelatin.

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  • Chemical & Material Sciences (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Dispersion Chemistry (AREA)
  • Organic Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Liquid Developers In Electrophotography (AREA)
  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
  • Developing Agents For Electrophotography (AREA)
US64826A 1969-08-18 1970-08-18 Liquid electrophotographic developers containing a dye modified polypeptide Expired - Lifetime US3679586A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP44064732A JPS4825940B1 (fr) 1969-08-18 1969-08-18

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US3679586A true US3679586A (en) 1972-07-25

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US (1) US3679586A (fr)
JP (1) JPS4825940B1 (fr)
BE (1) BE754862A (fr)
CA (1) CA926681A (fr)
DE (1) DE2040572C3 (fr)
FR (1) FR2057950A5 (fr)
GB (1) GB1318434A (fr)
NL (1) NL7012168A (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3793048A (en) * 1968-04-18 1974-02-19 S Nagashima Developing process using toners at a reactor product between a dye having an amino group and organic halide
FR2832816A1 (fr) * 2001-11-26 2003-05-30 Australia Res Lab Revelateurs liquides pour electrostatographie

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CA1096222A (fr) * 1976-06-01 1981-02-24 Domenic Santilli Revelateurs electrophotographiques liquides contenant des particules marquantes a base de colorant azoique, derivees de 2,3 naphtalenediol ou de ses derives

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3793048A (en) * 1968-04-18 1974-02-19 S Nagashima Developing process using toners at a reactor product between a dye having an amino group and organic halide
FR2832816A1 (fr) * 2001-11-26 2003-05-30 Australia Res Lab Revelateurs liquides pour electrostatographie

Also Published As

Publication number Publication date
BE754862A (fr) 1971-01-18
FR2057950A5 (fr) 1971-05-21
DE2040572C3 (de) 1975-07-24
JPS4825940B1 (fr) 1973-08-02
NL7012168A (fr) 1971-02-22
DE2040572B2 (de) 1974-11-28
DE2040572A1 (de) 1971-03-11
CA926681A (en) 1973-05-22
GB1318434A (en) 1973-05-31

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