EP0704768A1 - Toner für Zweikomponentenentwickler - Google Patents

Toner für Zweikomponentenentwickler Download PDF

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Publication number
EP0704768A1
EP0704768A1 EP95305610A EP95305610A EP0704768A1 EP 0704768 A1 EP0704768 A1 EP 0704768A1 EP 95305610 A EP95305610 A EP 95305610A EP 95305610 A EP95305610 A EP 95305610A EP 0704768 A1 EP0704768 A1 EP 0704768A1
Authority
EP
European Patent Office
Prior art keywords
toner
monomer
alkyl group
particle
carbon atoms
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.)
Ceased
Application number
EP95305610A
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English (en)
French (fr)
Inventor
Masatomi c/o Mita Industrial Co Ltd. Funato
Seijiro c/o Mita Industrial Co Ltd. Ishimaru
Yoshitake c/o Mita Industrial Co Ltd. Shimizu
Norio c/o Mita Industrial Co Ltd. Kubo
Kazuya c/o Mita Industrial Co. Ltd. Nagao
Terumichi c/o Mita Industrial Co. Ltd. Asano
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.)
Kyocera Mita Industrial Co Ltd
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Mita Industrial Co Ltd
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Filing date
Publication date
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Publication of EP0704768A1 publication Critical patent/EP0704768A1/de
Ceased 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
    • G03G9/087—Binders for toner particles
    • G03G9/08784—Macromolecular material not specially provided for in a single one of groups G03G9/08702 - G03G9/08775
    • G03G9/08791—Macromolecular material not specially provided for in a single one of groups G03G9/08702 - G03G9/08775 characterised by the presence of specified groups or side chains
    • 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
    • G03G9/083—Magnetic 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
    • G03G9/087—Binders for toner particles
    • G03G9/08702—Binders for toner particles comprising macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
    • G03G9/08704—Polyalkenes
    • 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
    • G03G9/087—Binders for toner particles
    • G03G9/08702—Binders for toner particles comprising macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
    • G03G9/08706—Polymers of alkenyl-aromatic compounds
    • G03G9/08708—Copolymers of styrene
    • 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
    • G03G9/087—Binders for toner particles
    • G03G9/08702—Binders for toner particles comprising macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
    • G03G9/08722—Polyvinylalcohols; Polyallylalcohols; Polyvinylethers; Polyvinylaldehydes; Polyvinylketones; Polyvinylketals
    • 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
    • G03G9/087—Binders for toner particles
    • G03G9/08702—Binders for toner particles comprising macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
    • G03G9/08726—Polymers of unsaturated acids or derivatives thereof
    • G03G9/08728—Polymers of esters
    • 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
    • G03G9/087—Binders for toner particles
    • G03G9/08702—Binders for toner particles comprising macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
    • G03G9/08737—Polymers derived from conjugated dienes

Definitions

  • the present invention relates to toner for a two-component type developer used for electrophotography. More particularly, the present invention relates to toner, which does not include a charge control agent, suitably used in an electrophotographic image forming apparatus such as an electrostatic copying machine and a laser beam printer.
  • a two-component type developer is used as one of the developers used for developing an electrostatic latent image on a photosensitive body in an electrophotographic image forming apparatus.
  • the two-component type developer includes toner comprising a binder resin and a coloring agent such as carbon black, and magnetic carrier such as iron powder and ferrite particles.
  • An electrostatic latent image is developed by the following steps.
  • the developer forms a magnetic brush shape on a developing roller by a magnetic field thereof and is carried out to the photosensitive body.
  • the toner is charged by friction with the carrier so as to have a desired charge and polarity of charge.
  • the developer is contacted with the photosensitive body by the developing roller, resulting in attaching the toner onto the electrostatic latent image formed thereon.
  • the toner includes a charge control agent which controls and stabilizes the charge of the toner so as to attach a constant amount of the toner on the electrostatic latent image and provide a good developed image for a long period of time.
  • Negatively charged toner includes a negative charge control agent such as a dye of a metal complex including a metal ion such as chrome(III) (for example, an azo compound - chrome(III) complex), and an oxycarboxylic acid - metal complex (for example, a salicylic acid - metal complex) (Japanese Laid-Open Patent Publication No. 3-67268).
  • Positively charged toner includes a positive charge control agent such as an oil soluble dye including nigrosine and an amine type charge control agent (Japanese Laid-Open Patent Publication No. 56-106249).
  • metal complexes including a heavy metal ion such as a chrome ion
  • a heavy metal ion such as a chrome ion
  • the charge control agent is expensive as compared with the other materials for toner such as a binder resin and a coloring agent, for example, carbon black. Therefore, although the charge control agent has a content of merely several %, this results in increasing the price of the resultant toner. Accordingly, it is desired to develop toner having no charge control agent of a metal complex.
  • the toner components tend to attach on a surface of the carrier particle.
  • the attached components are called a spent.
  • the spent makes the carrier charge with the same polarity as the toner, resulting in the disadvantages that the toner can be scattered and transfer efficiency of toner image is decreased.
  • the toner for a two-component type developer of the present invention which overcomes the above-discussed and numerous other disadvantages and deficiencies of the prior art, comprises toner particles including a binder resin, magnetic powder dispersed in the binder resin and a releasing agent.
  • the binder resin is made of a composition including at least one of the following:
  • an extracted solution obtained by extracting the toner with methanol has substantially no absorption peak in the range between 280 and 350 nm, and has a substantially zero absorbance in the range between 400 and 700 nm.
  • the magnetic powder is contained in the range between 0.5 and 3 parts by weight per 100 parts by weight of the binder resin.
  • the toner particles have a volume-based average particle diameter of 5 through 15 ⁇ m, and spacer particles with a volume-based average particle diameter of 0.05 through 1.0 ⁇ m are attached onto surfaces of the toner particles.
  • the invention described herein makes possible the advantages of (1) providing toner with excellent chargeability including no charge control agent at all; (2) providing toner little scattered in development for realizing a copied image with a high quality; and (3) providing toner in which a spent is not caused even when used for a long period of time, and hence, by which an excellent image quality can be maintained and transfer efficiency can be stabilized.
  • Toner for a two-component type developer according to the present invention has no charge control agent, such as a dye of an azo compound - metal complex and an oxycarboxylic acid - metal complex, at all. Therefore, a spent caused by a charge control agent, which will be described in detail below, scarcely occurs in the present toner, resulting in realizing a high quality copied image for a long period of time. Since the toner of the present invention has no charge control agent, it is impossible to detect any charge control agent, i.e., a dye type compound, from the toner by any chemical or physical method. For example, such a compound cannot be detected in the present toner by any chemical reaction.
  • absorption peaks owing to such a compound cannot be detected in an organic solvent extracted solution of the present toner.
  • the present toner is extracted with an organic solvent such as methanol
  • the extracted solution has substantially no absorption peak in the range of 280 to 350 nm, and has substantially zero absorbance in the range of 400 to 700 nm.
  • “to have substantially no absorption peak” means, in an extracted solution obtained by extracting 0.1 g of the present toner with 50 ml of methanol, absorption peaks are not detected at all, or if detected, values of the absorbance peaks are 0.05 or less.
  • “to have substantially zero absorbance” means that values of the absorbance of the extracted solution obtained by extracting 0.1 g of the present toner with 50 ml of methanol are 0.05 or less.
  • a polymer having an anionic group is used as a binder resin of a toner particle; and secondly, magnetic powder is contained in the toner particle at a predetermined proportion.
  • a polymer obtained from a monomer having an alkyl group containing 12 or more carbon atoms as the side chain is used as the binder resin. Therefore, the wax, that is, a release agent is well dispersed and prevented from attaching onto the surfaces of the carrier particles to cause the spent, thereby elongating the life time of the carrier.
  • spacer particles having a desired particle diameter are attached on the surfaces of the toner particles, if necessary, thereby increasing transfer efficiency of the toner.
  • Figure 1 shows an UV-visible spectrum of a methanol extracted solution of the present toner in the range of 200 to 700 nm.
  • the extracted solution has no peak, which is otherwise formed because of a charge control agent.
  • the solution has substantially no absorption peak in the range of 280 to 350 nm, and the absorbance in the range of 400 to 700 nm is substantially zero.
  • absorption peaks are found in the range of 400 to 700 nm, in particular, 550 to 570 nm.
  • an absorption peak is found in the range of 280 to 350 nm.
  • the charge control agent is present on the surfaces of the toner particles at a rather high concentration that the methanol extracted solution of the toner having the charge control agent has absorption peaks due to the charge control agent.
  • a carrier included in a developer which has insufficient chargeability owing to occurrence of a spent is extracted with methanol, and then the UV-visible spectrum of the extracted solution is measured to find absorption peaks in the range of 400 to 700 nm derived from a charge control agent.
  • the developer comprising the toner having a dye of an azo compound - chrome complex, whose UV-visible spectrum is shown in Figure 2 was used for a long period of time to cause a spent therein.
  • UV-visible spectrum of a methanol extracted solution of the carrier in this developer was measured to give the spectrum shown in Figure 4 .
  • absorption peaks are found at the same position as the spectrum in Figure 2 .
  • toner comprising toner particles containing 1.5 wt% of the dye of the azo compound - chrome complex was mixed with a carrier to obtain a developer.
  • the toner and the carrier was shaken for a predetermined period of time.
  • Figure 5 shows a relationship between the shaking time and amount of an attachment on the surfaces of the carrier particles.
  • the amount of attachment is indicated as a spent ratio, that is, a percentage based on a total weight of the carrier particles bearing the attachment.
  • Figure 6 shows the relationship between the shaking time and the amount of charge of the toner. The same procedure was repeated with regard to a developer comprising toner having no charge control agent and carrier.
  • the present inventors measured the weight of the attachment on the surfaces of the carrier particles resulting from mixing the carrier with each of the toner components, that is, a charge control agent, a binder resin, carbon black as a coloring agent and wax, so as to find out the relationships between the respective toner components and the spent.
  • the results are shown in Figure 8 as a variation with time in the amount of the attachment (i.e., amount of the spent), wherein the results obtained from the mixture with the charge control agent is plotted with white circles, those from the carbon black with black circles, those from the binder resin with squares, and those from the wax with triangles. It is apparent from Figure 8 that the charge control agent causes the largest amount of attachment due to the spent.
  • the toner does not have a charge control agent not only because the agent can include a heavy metal but also because the agent is the main cause of the spent, scatter of the toner and of a decrease in the transfer efficiency of the toner. Accordingly, the present toner has no charge control agent at all.
  • the instability of charge of the toner due to the lack of the charge control agent, in particular, the insufficiency in charge amount of the toner is compensated by using a binder resin having an anionic group as mentioned above.
  • the insufficiency in charge amount of the toner particles can be supplemented because the binder resin has a negative charge in itself owing to the anionic group included therein. Since the anionic group is bonded to the main chain of the binder resin, it would never move onto the surface of the carrier particle as the charge control agent does, and hence it never causes the spent.
  • the present toner includes magnetic powder at a predetermined proportion, that is, 0.1 to 5 parts by weight on the basis of 100 parts by weight of the binder resin.
  • the insufficiency in the charge amount of the toner particles can be thus compensated for.
  • the magnetic powder contained in the toner particle causes magnetic attraction between the toner particle and the carrier particle. This magnetic attraction between the toner particle and the carrier particle together with electrostatic attraction prevents the toner from scattering.
  • the number of the toner particles to be attached onto an electrostatic latent image is increased as the charge amount of one toner particle is smaller, apparent development sensitivity is increased.
  • the content of the magnetic powder in the toner particles is in the range of 0.1 to 5 parts by weight per 100 parts by weight of the binder resin as described above.
  • the content is less than 0.1 parts by weight, the charge amount of the toner particle is insufficient, resulting in insufficient coupling with the carrier particle and causing toner scattering. In this case, a fog can be disadvantageously formed on a copied image.
  • the density of the copied image is low because of the insufficient charge amount.
  • the contents exceeds 5 parts by weight the magnetic attraction between the carrier particle and the toner particle becomes so strong that the toner is not sufficiently attached onto an electrostatic latent image, resulting in decreasing the density of the copied image.
  • Japanese Laid-Open Patent Publication No. 56-106249 discloses a toner particle including 10 wt% of ferrite
  • Japanese Laid-Open Patent Publication No. 59-162563 discloses a toner particle including 5 through 35 wt% of a magnetic fine particle. In either case, however, the content of the magnetic powder is excessive, and hence, the density of the copied image is low.
  • Japanese Laid-Open Patent Publication No. 3-67268 discloses toner to which 0.05 to 2 wt% of magnetic powder is externally added.
  • the magnetic powder since the magnetic powder is not included in the toner particle, the powder is likely to be ununiformly attached onto the surface of the toner particle, resulting in insufficient magnetic attraction between the toner particle and the carrier particle. Furthermore, in either of the above-mentioned toners, the spent can be disadvantageously caused because a charge control agent is contained therein.
  • the binder resin for the toner particles is made of a polymer obtained from a monomer having an alkyl group containing 12 or more carbon atoms at the side chain.
  • This polymer can be any of the aforementioned resins having an anionic group or another polymer.
  • the toner particles When transferred image is thermally fixed with heat rollers, the toner particles generally include a releasing agent for preventing the offset of the image onto the transfer paper.
  • a releasing agent for preventing the offset of the image onto the transfer paper.
  • wax and olefin resins can be used as the releasing agent. Such a releasing agent is heated and kneaded together with the binder resin and the magnetic powder in the production process of the toner.
  • a SP value of the releasing agent is different (a solubility parameter value) from that of the generally used binder resin, and hence, the compatibility between the releasing agent and the binder resin is poor. Therefore, the releasing agent cannot be sufficiently dispersed in the resin in the heating and kneading process. As a result, the releasing agent is ununiformly present on the resultant toner particles in the shape of a comparatively large particle, and the particle of the releasing agent is also present on the surface of the toner particle. Accordingly, when such toner particles are used with carrier, the releasing agent is attached onto the surfaces of carrier particles, thereby causing a spent.
  • the binder resin is made of the polymer obtained from a monomer having an alkyl group containing 12 or more carbon atoms at the side chain as described above, the compatibility between the releasing agent and the binder resin is improved. Thus, the problem of the spent can be overcome.
  • spacer particles having a particle diameter of 0.05 through 1.0 ⁇ m are attached preferably onto the surfaces of the toner particles in order to increase the transfer efficiency of the toner image.
  • the spacer particles can work to enhance fluidity of the toner, and in addition, form a gap between the photosensitive body and the toner particles when the toner is attached onto the electrostatic latent image formed on the photosensitive body. Therefore, the toner can be transferred from the photosensitive body onto the transfer paper with ease even when the toner attains a large quantity of charge through a long copying operation, resulting in a high transfer efficiency of the toner.
  • the spacer particle is similar to the particle of the magnetic powder included in the toner particle, the magnetic attraction between the toner particle and the carrier particle can be further enhanced, thereby further preventing toner scattering and a fog.
  • a fine particle having a particle diameter of approximately 0.015 ⁇ m is used to enhance fluidity of a conventional toner. Such a small particle cannot form a sufficient gap between the photosensitive body and the toner particles, and cannot work as the spacer particle for the aforementioned purposes.
  • a "lower alkyl group” indicates alkyl group having 1 to 5 carbon atoms.
  • the binder resin contained in the toner particles of the present invention is made of a composition including at least one of the following: (1) a copolymer obtained from a monomer having an anionic group and a monomer having an alkyl group containing 12 or more carbon atoms at the side chain, or a mixture thereof with other monomers; and (2) a mixture of a polymer obtained from a monomer having an anionic group or a mixture of the monomer having an anionic group with other monomers, and a polymer obtained from a monomer having an alkyl group containing 12 or more carbon atoms at the side chain or a mixture of the monomer having an alkyl group containing 12 or more carbon atom with other monomers.
  • the "side chain" of a monomer herein indicates a portion where a side chain of a (co)polymer obtained from the monomer can be formed.
  • the copolymer including an anionic group and an alkyl group containing 12 or more carbon atoms at the side chain can be obtained through copolymerization using a monomer having an anionic group and a monomer having an alkyl group containing 12 or more carbon atoms at the side chain.
  • the copolymer can be a copolymer obtained from a monomer having an anionic group and a monomer having an alkyl group containing 12 or more carbon atoms at the side chain, or can be a copolymer obtained from these monomers and other monomers. Alternatively, the copolymer can be a mixture of these copolymers.
  • the former polymer can be a homopolymer obtained from the monomer having an anionic group or a copolymer obtained from a monomer having an anionic group and other monomers, or a mixture of such polymers.
  • the latter polymer can be a polymer obtained from the monomer having an alkyl group containing 12 or more carbon atoms at the side chain or a mixture of the monomer having an alkyl group containing 12 or more carbon atom with other monomers or a copolymer obtained from a monomer having an alkyl group containing 12 or more carbon atoms and other monomers, or a mixture of such polymers.
  • Such copolymers can be a random copolymer, a block copolymer or a graft copolymer.
  • the binder resin used in the present toner preferably comprises the polymer of item (1), that is, a copolymer obtained from a monomer having an anionic group and a monomer having an alkyl group containing 12 or more carbon atoms at the side chain. More preferably, the binder resin used in the present toner comprises the copolymer prepared by polymerizing a monomer having an anionic group, a monomer having an alkyl group containing 12 or more carbon atoms at the side chain and other monomers.
  • Examples of the monomer having an anionic group include monomers having a carboxylic acid group, a sulfonic acid group or a phosphoric acid group, and a monomer having a carboxylic acid group is generally used.
  • Examples of the monomer having a carboxylic acid group include ethylenically unsaturated carboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, maleic acid and fumaric acid; monomers that can form a carboxylic acid group such as maleic anhydride; and lower alkyl halfester of dicarboxylic acid such as maleic acid and fumaric acid.
  • Examples of the monomer having a sulfonic acid group include styrene sulfonic acid and 2-acrylamido-2-methylpropane sulfonic acid.
  • Examples of the monomer having a phosphoric acid group include 2-phosphono(oxy)propylmethacrylate, 2-phosphono(oxy) ethylmethacrylate, 3-chloro-2-phosphono(oxy) propylmethacrylate.
  • Such a monomer having an anionic group can be a free acid, a salt of an alkaline metal such as sodium and potassium, a salt of an alkaline earth metal such as calcium and magnesium, and a salt such as zinc.
  • the alkyl group containing 12 or more carbon atoms herein includes an acyclic linear hydrocarbon group, an acyclic branched hydrocarbon group and a cyclic hydrocarbon group.
  • Examples of the monomer having an alkyl group containing 12 or more carbon atoms at the side chain include an ethylenically unsaturated carboxylic acid ester such as acrylic acid ester and methacrylic acid ester having an alkyl group containing 12 or more carbon atoms linked through an ester bond; a vinyl ester having an alkyl group containing 12 or more carbon atoms linked through an ester bond; a vinyl ether having an alkyl group containing 12 or more carbon atoms linked through an ether bond; a 1-alkene having 14 or more carbon atoms; a monovinyl arene having at least one substituent having an alkyl group containing 12 or more carbon atoms; and a 1,3-alkadiene having at least one alkyl group containing 12 or more carbon atoms.
  • One or a combination of two or more can be used.
  • the ethylenically unsaturated carboxylic acid ester having an alkyl group containing 12 or more carbon atoms at the side chain is represented by the following Formula (I): wherein R1 is a hydrogen atom or a lower alkyl group; and R is an alkyl group containing 12 or more carbon atoms.
  • Examples of such an ethylenically unsaturated carboxylic acid ester having an alkyl group containing 12 or more carbon atoms include lauryl acrylate, tridecyl acrylate, stearyl acrylate, docosyl acrylate, dicyclohexylmethyl acrylate, dicyclohexylpropyl acrylate, cyclododecyl acrylate, cycloundecanemethyl acrylate, lauryl methacrylate, tridecyl methacrylate, stearyl methacrylate, docosyl methacrylate, dicyclohexylmethyl methacrylate, dicyclohexylpropyl methacrylate, cyclododecyl methacrylate and cycloundecanemethyl methacrylate.
  • the vinyl ester having an alkyl group containing 12 or more carbon atoms at the side chain is represented by the following Formula (II): wherein R3 is an alkyl group containing 12 or more carbon atoms.
  • vinyl ester examples include vinyl laurate, vinyl tridecanoate, vinyl stearate, vinyl docosanoate, vinyl triacontanoate, vinyl pentylcyclohexanoate and vinyl dicyclohexylacetate.
  • vinyl ether examples include vinyl lauryl ether, vinyl stearyl ether, vinyl docosyl ether and vinyl cyclododecyl ether.
  • the 1-alkene having 14 or more carbon atoms is represented by the following Formula (IV): wherein R5 and R6 are independently a hydrogen atom or an alkyl group containing 12 or more carbon atoms.
  • Examples of such a 1-alkene include 1-tetradecene and 1-eicocene.
  • the monovinyl arene having at least one substituent having an alkyl group containing 12 or more carbon atoms is represented by the following Formula (V): wherein R7 is a hydrogen atom, a lower alkyl group, an alkyl group containing 12 or more carbon atoms or a halogen atom; R8 is an alkoxy group, an amino group, a nitro group or an alkyl group containing 12 or more carbon atoms; and ⁇ is a phenylene group.
  • the phenylene group can include another substituent such as a lower alkyl group, a halogen atom, an alkoxy group, an amino group, a nitro group and an alkyl group containing 12 or more carbon atoms.
  • the alkyl group containing 12 or more carbon atoms can be linked via an ester bond, a (thio)ether bond or an amido bond.
  • Examples of such a monovinyl arene include m-raulylstyrene, p-raulylstyrene, m-stearylstyrene, p-stearylstyrene, ⁇ -methyl-3-stearylstyrene, m-stearoxystyrene, p-stearoxystyrene, stearyl 4-vinylbenzoate and 4-stearoylaminostyrene.
  • the 1,3-alkadiene having an alkyl group containing 12 or more carbon atoms is represented by the following Formula (VI): wherein R9, R10 and R11 are independently a hydrogen atom, a lower alkyl group, an alkyl group containing 12 or more carbon atoms or a halogen atom.
  • Examples of such a 1,3-alkadiene include 1,3-hexadecadiene, 1,3-docosadiene and 2-methyl-1,3-docosadiene.
  • the other monomer that is polymerized with the monomer having an anionic group and/or the monomer having an alkyl group containing 12 or more carbon atoms at the side chain, if necessary, is selected so that the resultant polymer can attain a sufficient fixability and chargeability required of toner, and is prepared from one or a combination of two or more of monomers including an ethylenically unsaturated bond.
  • Examples of such a monomer include ethylenically unsaturated carboxylic acid esters, monovinyl arenes, vinyl esters, vinyl ethers, diolefins and monoolefins.
  • the ethylenically unsaturated carboxylic acid esters are represented by the following Formula (VII): wherein R1 is a hydrogen atom or a lower alkyl group; and R13 is a hydrocarbon group having 11 or less carbon atoms or a hydroxyalkyl group having 11 or less carbon atoms.
  • Examples of such ethylenically unsaturated carboxylic acid esters include methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate, phenyl acrylate, methyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, ⁇ -hydroxyethylacrylate, ⁇ -hydroxypropylacrylate, ⁇ -hydroxybutylacrylate and ⁇ -hydroxyethylmethacrylate.
  • the monovinyl arenes are represented by the following Formula (VIII): wherein R14 is a hydrogen atom, a lower alkyl group or a halogen atom; R15 is a hydrogen atom, a lower alkyl group, a halogen atom, an alkoxy group, an amino group or a nitro group; and ⁇ is a phenylene group.
  • Examples of such monovinyl arenes include styrene, ⁇ -methylstyrene, vinyltoluene, ⁇ -chlorostyrene, o-chlorostyrene, m-chlorostyrene, p-chlorostyrene and p-ethylstyrene.
  • the vinyl esters are represented by the following Formula (IX): wherein R16 is a hydrogen atom or a lower alkyl group.
  • vinyl esters examples include vinyl formate, vinyl acetate and vinyl propionate.
  • vinyl ethers examples include vinyl methyl ether, vinyl ethyl ether, vinyl n-butyl ether, vinyl phenyl ether and vinyl cyclohexyl ether.
  • the diolefins are represented by the following Formula (XI): wherein R18, R19 and R0 are independently a hydrogen atom, a lower alkyl group or a halogen atom.
  • diolefins examples include butadiene, isoprene and chloroprene.
  • the monoolefins are represented by the following Formula (XII): wherein R1 and R are independently a hydrogen atom or a lower alkyl group.
  • Examples of such monoolefins include ethylene, propylene, isobutylene, 1-butene, 1-pentene and 4-methyl-1-pentene.
  • Examples of the polymer obtained from a monomer having an anionic group and/or a monomer having an alkyl group containing 12 or more carbon atoms at the side chain or a mixture of the monomer having an alkyl group containing 12 or more carbon atom with other monomers include (meth)acrylic acid-stearyl (meth)acrylate copolymers, styrene-stearyl (meth)acrylate-(meth)acrylic acid copolymers, styrene-(meth)acrylate-stearyl (meth)acrylate-(meth)acrylic acid copolymers, styrene-stearyl (meth)acrylate-maleic acid copolymers, maleic acid-stearyl (meth)acrylate copolymers, styrene-tridecyl (meth)acrylate-(meth)acrylic acid copolymers, and styrene-lauryl (meth)acrylate-(meth)acrylic
  • a polyester resin having an anionic group can be also used. It is preferable that such a composition includes the anionic group preferably at a proportion for attaining an acid value of 2 through 30, preferably 5 through 15, when the anionic group is present as a free acid. When part or the entire anionic group is neutralized, the anionic group is contained preferably at such a proportion that the acid value would be within the aforementioned range in assuming that it is present as a free acid. When the acid value of the polymer, i.e., the concentration of the anionic group, is below the aforementioned range, the chargeability of the resultant toner is insufficient. When it exceeds the range, the resultant toner disadvantageously has a hygroscopic property.
  • the monomer having an alkyl group containing 12 or more carbon atoms at the side chain is contained in the range of 0.1 to 20 parts by weight, more preferably 0.5 to 10 parts by weight, and most preferably 1 to 5 parts by weight per 100 parts by weight of the entire monomers.
  • the content of the monomer having an alkyl group containing 12 or more carbon atoms is below the aforementioned range, the compatibility between the releasing agent and the binder resin is so poor that the spent is caused with ease.
  • it exceeds the range the Tg of the binder resin is too low to achieve sufficient storage stability.
  • a preferable binder resin is obtained from any of the aforementioned monomers having an anionic group and at least one of the ethylenically unsaturated carboxylic acid esters represented by Formula (I), and any of the monomers represented by Formulae (II) through (VI) can be optionally copolymerized, if necessary. Other monomers can be coplymerized, if necessary.
  • the resin is obtained from one or a combination of two or more of the aforementioned monomers.
  • the binder resin used in the present toner is made of a composition including one of the aforementioned copolymers or the mixture of the copolymers, and can further include a polymer having neither an anionic group nor an alkyl group containing 12 or more carbon atoms as well.
  • the contents of the anionic group and the alkyl group containing 12 or more carbon atoms are preferably within the aforementioned ranges, respectively.
  • the magnetic powder contained in (inclusively added to) the toner particles can be any magnetic powder used in a conventional one-component type developer.
  • the material for the magnetic powder include triiron tetroxide (Fe3O4), maghemite ( ⁇ -Fe2O3), zinc iron oxide (ZnFe2O4), yttrium iron oxide (Y3Fe5O12), cadmium iron oxide (CdFe2O4), gadolinium iron oxide (Gd3Fe5O12), copper iron oxide (CuFe2O4), lead iron oxide (PbFe12O19), nickel iron oxide (NiFe2O4), neodyum iron oxide (NdFeO3), barium iron oxide (BaFe12O19), magnesium iron oxide (MgFe2O4), manganese iron oxide (MnFe2O4), lanthanum iron oxide (LaFeO3), iron (Fe), cobalt (Co) and Nickel (Ni).
  • Particularly preferable magnetic powder is made from triiron tetroxide (magnetite) in the shape of fine particles.
  • the particle of preferable magnetite is in the shape of a regular octahedron with a particle diameter of 0.05 through 1.0 ⁇ m.
  • Such a magnetite particle can be subjected to a surface treatment with a silane coupling agent or a titanium coupling agent.
  • the particle diameter of the magnetic powder contained in the toner particle is generally 1.0 ⁇ m or smaller, and preferably 0.05 through 1.0 ⁇ m.
  • the content of the magnetic powder in the toner particle is in the range of 0.1 to 5 parts by weight, more preferably 0.5 to 4 parts by weight, and most preferably 0.5 to 3 parts by weight per 100 parts by weight of the binder resin.
  • the toner can be scattered during the development and the transfer efficiency of the toner can be decreased as described above.
  • a releasing agent is one of an additive included in toner particles.
  • various types of natural or synthetic wax and olefin resins having a molecular weight of 2,000 through 16,000, preferably 3,000 through 6,000 can be used as the releasing agent.
  • the olefin resin include polypropylene, polyethylene, and propylene-ethylene copolymers, and polypropylene is particularly preferred.
  • the content of the releasing agent is in the range of 0.01 to 6 parts by weight, more preferably 0.1 to 5 parts by weight on the basis of 100 parts by weight of the binder resin.
  • Such a releasing agent works to prevent the offset of an image in the thermal fixing process. When the content is smaller than 0.01 part by weight, the preventive effect on offset in the thermal fixing process can be insufficient, and when it exceeds 6 parts by weight, a spent is likely to be caused.
  • the toner particle contains, as described above, the binder resin and the magnetic powder as indispensable components, and can optionally include some inner additive generally used for a toner, if necessary.
  • additives examples include a coloring agent and a release agent.
  • the following pigments can be used:
  • Such a pigment is contained in the toner particle in the range of 2 to 20 percent by weight, and preferably 5 to 15 parts by weight per 100 parts by weight of the binder resin.
  • the toner particles in the present toner can be produced by any ordinary method for toner particles such as crushing and classification, fusing granulation, spray granulation and polymerization, and are generally produced by the crushing and classification method.
  • the components for the toner particles are previously mixed in a mixer such as a Henschel mixer, kneaded with a kneader such as a biaxial extruder, and then cooled. The resultant is crushed and classified to give toner particles.
  • the particle diameter of the toner particle is generally in the range of 5 to 15 ⁇ m and preferably 7 to 12 ⁇ m in the volume-based average particle diameter (a medium size measured with a Coulter counter).
  • a fluidity enhancer such as hydrophobic vapor depositioned silica particles onto the surfaces of the toner particles, if necessary.
  • the primary particle diameter of the fluidity enhancer such as the silica particles is generally approximately 0.015 ⁇ m, and such a fluidity enhancer is added to the toner in the range of 0.1 to 2.0 percent by weight on the basis of the weight of the entire toner, i.e., the total weight of the toner particles and the fluidity enhancer.
  • spacer particles having a larger particle diameter than that of the fluidity enhancer are preferably added in the present invention.
  • any of organic and inorganic inactive particles with a particle diameter of 0.05 through 1.0 ⁇ m, more preferably 0.07 through 0.5 ⁇ m can be used.
  • the material for such inactive particles include silica, alumina, titanium oxide, magnesium carbonate, an acrylic resin, a styrene resin and magnetic materials.
  • the spacer particle can not only work as a fluidity enhancer but also increase the transfer efficiency as described above.
  • the same type of magnetic powder as included in the toner particle in particular, triiron tetroxide (magnetite) in the shape of fine particle is preferably used.
  • the magnetic powder when used as the spacer particles, effectively suppresses the scattering of the toner as described above.
  • the content of the spacer particles is 10 percent by weight or less, more preferably in the range of 0.1 to 10 percent by weight, and most preferably 0.1 to 5 percent by weight on the basis of the total weight of the toner.
  • the spacer particles are excessively included in toner, the density of a copied image is insufficient.
  • the magnetic powder is used as the spacer particles, the total amount of the magnetic powder together with that contained in the toner particles is preferably 10 parts by weight or less per 100 parts by weight of the binder resin. When it is excessively included, the density of a copied image can be decreased.
  • the fluidity enhancer and the spacer particles are added to the toner particles
  • the following production method is preferred:
  • the fluidity enhancer and the spacer particles are first sufficiently mixed with each other, and then the obtained mixture is added to the toner particles, and then is sufficiently unbound.
  • the spacer particles can be attached onto the surfaces of the toner particles.
  • To "be attached” herein means both to be held in contact with the surface of the toner particle and to be partly embedded in the toner particle. In this manner, the toner of the present invention is produced.
  • generally used magnetite or ferrite can be used as a carrier for the two-component type developer.
  • the electrical resistance is little varied with time or by the change of the environment, and hence, it can provide the resultant developer with a stable chargeability.
  • such a compound is formed into a soft spicated shape in the developing apparatus when a magnetic field is applied. This prevents the turbulence of a toner image formed on the photosensitive body, thereby suppressing the formation of a white stripe in a copied image.
  • the carrier is charged preferably by allowing a resin having a cationic group to be contained in a coating layer of the carrier particle. Therefore, when this carrier is combined with toner including no charge control agent, the chargeability of the toner is remarkably improved, thereby stabilizing the chargeability of the toner. Furthermore, since the present toner does not include a charge control agent as the conventional developer does, the resultant developer can attain a longer life time by effectively preventing the spent from occurring on the carrier particles.
  • the carrier particle in the carrier used in the present invention is more preferably formed from a particle having a two-layered structure including a core particle and a coating layer over the core particle.
  • the core particle comprises a magnetic material represented by the following Formula (A): MOFe2O3 (A) wherein M is at least one metal selected from the group consisting of Cu, Zn, Fe, Ba, Ni, Mg, Mn, Al and Co.
  • the compound represented by Formula (A) is magnetite (wherein M is Fe) or ferrite (wherein M is one of the metals other than Fe), and ferrite, wherein M is Cu, Zn, Mn, Ni or Mg, is preferably used. Change of the electrical resistance of such magnetite and ferrite is little for a long time, and the magnetite and ferrite can be formed into a soft spicated shape in the developing apparatus when a magnetic field is applied.
  • the core particle comprising such a magnetic material has a particle diameter between 30 and 200 ⁇ m, and preferably between 50 and 150 ⁇ m.
  • the core particles are obtained by granulating the fine particles of the magnetic material by spray granulation and the like, and then heating the resultant particles.
  • the core particle has a volume specific resistivity between 105 and 109 ⁇ cm, and preferably between 106 and 108 ⁇ cm.
  • the saturation magnetization of the core particle is in the range of 30 to 70 emu/g, and preferably between 45 and 65 emu/g.
  • the resin having a cationic group included in the resin composition, which forms the coating layer of the carrier particle can be a thermoplastic resin and a thermosetting resin, and is preferably a thermosetting resin or a mixture of a thermosetting resin and a thermoplastic resin in terms of the heat resistance and the durability.
  • the cationic group include a basic nitrogen containing group such as primary, secondary and tertiary amino groups, a quaternary ammonium group, an amido group, an imino group, an imido group, a hydrazino group, a guanidino group and an amidino group, among which an amino group and a quaternary ammonium group are particularly preferred.
  • thermoplastic resin having a cationic group examples include thermoplastic acrylic resins, thermoplastic styrene-acrylic resins, polyester resins, polyamide resins and olefin copolymer, each of which includes a cationic group.
  • thermosetting resin examples include modified and unmodified silicone resins, thermosetting acrylic resins, thermosetting styrene-acrylic resins, phenol resins, urethane resins, thermosetting polyester resins, epoxy resins and amino resins, each of which includes a cationic group.
  • Such a resin including a cationic group is obtained by polymerizing a monomer having a cationic group or a mixture containing the monomer having a cationic group.
  • such a resin is obtained by linking a compound having a cationic group with a resin having no cationic group.
  • a monomer having a cationic group and/or other monomers are (co)polymerized by using a polymerization initiator having a cationic group, thereby introducing the cationic group into the resultant resin.
  • the resin having a cationic group When a resin prepared from alkoxysilane or alkoxytitanium is used, it is possible to produce the resin having a cationic group by allowing a silane coupling agent having a cationic group to react with the resin during or after the preparation of the resin.
  • the silane coupling agent include N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, ⁇ -aminopropyltriethoxysilane and N-phenyl -3-aminopropyltrimethoxysilane.
  • silane coupling agent can be linked onto the surface of the core particle via a hydroxyl group generally present on the surface of the core particle. Therefore, such a silane coupling agent can form the coating layer by itself.
  • the polymerization initiator having a cationic group include amidine type compound, e.g., azobis compounds.
  • the resin having a cationic group for forming the coating layer is used singly or together with any other of the aforementioned resins, or together with another resin having no cationic group.
  • the content of the cationic group in the resin having a cationic group is generally in the range of 0.1 to 2000 mmole, and preferably of 0.5 to 1,500 mmole per 100 g of the resin.
  • the cationic group is preferably contained in the entire resins forming the coating layer of the carrier particle at a proportion in the aforementioned range.
  • the resin composition forming the coating layer of the carrier particle includes at least one of the above-mentioned resins having a cationic group, together with another resin having no cationic group, if necessary.
  • a mixture of the resin having a cationic group and the resin having no cationic group include a mixture of an alkylated melamine resin and a styrene-acrylic copolymer, and a mixture of an alkylated melamine resin and an acryl-modified silicone resin.
  • the resin composition can further comprise an additive such as silica, alumina, carbon black, fatty acid metal salt, a silane coupling agent and silicone oil. These additives work for regulating physical properties of the coating layer.
  • the resin composition including a cationic group is applied to the surface of the core particle by a known method to form the coating layer.
  • the core particle is coated with a solution or a dispersion of the resin composition and dried, thereby forming the coating layer.
  • the core particle is coated with an uncured resin, or a solution or a dispersion of the oligomer, and then heated to cure the resin.
  • the coating layer can be formed by any of the generally used methods such as immersion, spray, a fluidized bed method, a moving bed method and a tumbling layer method.
  • a solvent used to dissolve or disperse the resin composition any of the ordinary organic solvents can be used.
  • the solvent examples include aromatic hydrocarbons such as toluene and xylene; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone; cyclic ethers such as tetrahydrofuran and dioxane; alcohols such as ethanol, propanol and butanol; cellosolves such as ethyl cellosolve and butyl cellosolve; esters such as ethyl acetate and butyl acetate; and amide type solvents such as dimethylformamide and dimethylacetoamide.
  • aromatic hydrocarbons such as toluene and xylene
  • ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone
  • cyclic ethers such as tetrahydrofuran and dioxane
  • alcohols such as ethanol, prop
  • the particle diameter of the thus obtained carrier particle is in the range of 30 to 200 ⁇ m, and preferably of 50 to 150 ⁇ m.
  • the weight ratio of the coating layer on the carrier particle is in the range of 0.001 to 2.5 parts by weight, and preferably of 0.005 to 2.0 parts by weight per 100 parts by weight of the core particle.
  • the obtained carrier particle has a volume specific resistivity in the range between 105 and 1013 ⁇ cm, and preferably between 107 and 101 ⁇ cm, and a saturation magnetization in the range between 30 and 70 emu/g, and preferably between 45 and 65 emu/g.
  • a two-component type developer is prepared by mixing the above-mentioned toner and carrier.
  • the mixing ratio of the carrier and the toner is generally 98:2 through 90:10, and preferably 97:3 through 94:6, by weight.
  • a copying operation is conducted using the present toner by a general electrophotographic method. Specifically, for example, a photoconductive layer on a photosensitive body is uniformly charged, and an image is exposed to form an electrostatic latent image thereon. Then, a magnetic brush made of the two-component magnetic developer is allowed to come in contact with the photosensitive body, thereby developing the electrostatic latent image with ease into a toner image. The thus obtained toner image is transferred onto transfer paper to form a transfer image, which is then applied with heat and pressure by a heat roller to fix the image thereon.
  • toner particles were added 0.3 part by weight of hydrophobic silica fine powder with an average particle diameter of 0.015 ⁇ m as a fluidity enhancer and 0.6 part by weight of hydrophobic alumina fine particles with an average particle diameter of 0.3 ⁇ m as spacer particles, on the basis of 100 parts by weight of the toner particles.
  • the resultant mixture was mixed with a Henschel mixer for 2 minutes to give toner.
  • the thus produced toner was homogeneously mixed with a ferrite carrier with an average particle diameter of 100 ⁇ m to give a two-component type developer with a toner concentration of 3.5 wt%.
  • Toner was prepared in the same manner as in Example 1 except that a styrene-acrylic copolymer including no alkyl group containing 12 or more carbon atoms at the side chain (wherein the weight ratio among styrene, acrylic acid and butyl methacrylate was 75:20:5) was used as a binder resin, and a developer was prepared by using the thus obtained toner.
  • Spherical ferrite particles with an average particle diameter of 100 ⁇ m were used as the magnetic core particles.
  • a coating agent with components as listed in Table 1 was added to 1000 parts by weight of the ferrite particles, and the resultant was mixed with a thermal stirrer. The solvent was removed from the resultant mixture, and the residue was subjected to a heat treatment at a temperature of 200°C for 1 hour to give carrier particles each having a coating layer.
  • the toner produced in Example 1 and the thus obtained carrier were homogeneously mixed to give a two-component type developer having a toner concentration of 3.5 wt%.
  • Example 2.1 The same procedure was repeated as in Example 2.1 except that a coating agent with components as listed in Table 1 was used, thereby preparing a developer.
  • Example 2.1 The same procedure was repeated as in Example 2.1 except that a coating agent with components as listed in Table 1 was used, thereby preparing a developer.
  • Example 1 Coating Agents of Examples 1-3 and Comparative Example 1.
  • component Example 1 Example 2
  • Comparative Example 1 Resin 1 Acryl-modified silicone Metylphenyl silicone Styrene-acrylic polymer none parts by weight 2.5 4.8 3.5
  • Resin 2 Metylated melamine ⁇ -aminopropyltriethoxysilane Methylated melamine none parts by weight 2.5 0.2 1.5
  • Example 1 containing the toner including the binder resin including an alkyl group containing 12 or more carbon atoms at the side chain had a smaller spent amount and was improved in the durability as compared with the developer of Comparative Example 1 containing the toner including the binder resin including no alkyl group containing 12 or more carbon atoms.
  • the developers produced in Examples 2.1 through 2.4 were excellently stable in resolution and charge amount. Furthermore, when these developers were used, no toner scattering was observed.
  • the developers of Examples 2.1 through 2.3 containing the carrier having a coating layer had a further lower fog density and a further smaller spent amount and were improved in durability as compared with the developer of Example 2.4 containing the carrier having no coating layer.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • Developing Agents For Electrophotography (AREA)
EP95305610A 1994-08-31 1995-08-11 Toner für Zweikomponentenentwickler Ceased EP0704768A1 (de)

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JP207442/94 1994-08-31
JP6207442A JPH0876417A (ja) 1994-08-31 1994-08-31 二成分系現像剤用トナー

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Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5480752A (en) * 1977-12-10 1979-06-27 Toshiba Corp Production of electrostatic latent image developing toners
JPS56106249A (en) 1980-01-28 1981-08-24 Fujitsu Ltd Developer
JPS59162563A (ja) 1983-03-07 1984-09-13 Minolta Camera Co Ltd 静電潜像現像用磁性現像剤
JPS6069659A (ja) * 1983-09-27 1985-04-20 Canon Inc マイクロカプセルトナー及びその製造方法
JPH025071A (ja) * 1988-06-24 1990-01-09 Fuji Xerox Co Ltd 熱定着乾式トナー
EP0357042A2 (de) * 1988-08-30 1990-03-07 TDK Corporation Zusammensetzung und Verfahren für die Entwicklung latenter elektrostatischer Bilder
EP0407604A1 (de) * 1988-12-28 1991-01-16 Mita Industrial Co., Ltd. Ladungssteuerungsharz, das harz enthaltender toner und verfahren zur herstellung dieses toners
JPH0367268A (ja) 1989-03-28 1991-03-22 Hitachi Chem Co Ltd 乾式トナー，乾式現像剤及び画像形成方法
JPH064950A (ja) * 1992-06-22 1994-01-14 Sharp Corp 音響機器におけるカセット収納機構
JPH06148936A (ja) * 1992-10-30 1994-05-27 Nippon Shokubai Co Ltd トナー組成物

Patent Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5480752A (en) * 1977-12-10 1979-06-27 Toshiba Corp Production of electrostatic latent image developing toners
JPS56106249A (en) 1980-01-28 1981-08-24 Fujitsu Ltd Developer
JPS59162563A (ja) 1983-03-07 1984-09-13 Minolta Camera Co Ltd 静電潜像現像用磁性現像剤
JPS6069659A (ja) * 1983-09-27 1985-04-20 Canon Inc マイクロカプセルトナー及びその製造方法
JPH025071A (ja) * 1988-06-24 1990-01-09 Fuji Xerox Co Ltd 熱定着乾式トナー
EP0357042A2 (de) * 1988-08-30 1990-03-07 TDK Corporation Zusammensetzung und Verfahren für die Entwicklung latenter elektrostatischer Bilder
EP0407604A1 (de) * 1988-12-28 1991-01-16 Mita Industrial Co., Ltd. Ladungssteuerungsharz, das harz enthaltender toner und verfahren zur herstellung dieses toners
JPH0367268A (ja) 1989-03-28 1991-03-22 Hitachi Chem Co Ltd 乾式トナー，乾式現像剤及び画像形成方法
JPH064950A (ja) * 1992-06-22 1994-01-14 Sharp Corp 音響機器におけるカセット収納機構
JPH06148936A (ja) * 1992-10-30 1994-05-27 Nippon Shokubai Co Ltd トナー組成物

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Title
DATABASE WPI Section Ch Week 7932, Derwent World Patents Index; Class G06, AN 79-58841b *
PATENT ABSTRACTS OF JAPAN vol. 14, no. 138 (P - 1022) 15 March 1990 (1990-03-15) *
PATENT ABSTRACTS OF JAPAN vol. 18, no. 457 (P - 1792) 25 August 1994 (1994-08-25) *
PATENT ABSTRACTS OF JAPAN vol. 9, no. 120 (P - 358)<1843> 24 May 1985 (1985-05-24) *
PATENT ABSTRACTS OF JAPAN vol. 9, no. 207 (P - 382) 24 August 1985 (1985-08-24) *

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JPH0876417A (ja) 1996-03-22
KR960008437A (ko) 1996-03-22

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