EP0034423A1 - Procédé de fabrication de particules véhiculatrices revêtues pour des mélanges de développement électrostatographique - Google Patents
Procédé de fabrication de particules véhiculatrices revêtues pour des mélanges de développement électrostatographique Download PDFInfo
- Publication number
- EP0034423A1 EP0034423A1 EP19810300373 EP81300373A EP0034423A1 EP 0034423 A1 EP0034423 A1 EP 0034423A1 EP 19810300373 EP19810300373 EP 19810300373 EP 81300373 A EP81300373 A EP 81300373A EP 0034423 A1 EP0034423 A1 EP 0034423A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- carrier
- coating
- particles
- carrier particles
- core
- 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
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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
- G03G9/10—Developers with toner particles characterised by carrier particles
- G03G9/113—Developers with toner particles characterised by carrier particles having coatings applied thereto
- G03G9/1131—Coating methods; Structure of coatings
-
- 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
- G03G9/10—Developers with toner particles characterised by carrier particles
- G03G9/113—Developers with toner particles characterised by carrier particles having coatings applied thereto
- G03G9/1132—Macromolecular components of coatings
- G03G9/1133—Macromolecular components of coatings obtained by reactions only involving carbon-to-carbon unsaturated bonds
- G03G9/1134—Macromolecular components of coatings obtained by reactions only involving carbon-to-carbon unsaturated bonds containing fluorine atoms
Definitions
- This invention is concerned with carrier particles for electrostatographic toner.
- the resulting electrostatic latent image is developed by depositing thereon a finely-divided electroscopic material referred to in the art as toner, the toner being generally attracted to the areas of the layer which retain a charge, thus forming a toner image corresponding to the electrostatic latent image.
- the toner image can be transferred to a support surface such as paper and this transferred image can be permanently affixed to the support surface using a variety of techniques including pressure fixing, heat fixing, solvent fixing, and the like.
- Carrier materials used in the development of electrostatic latent images are described in many patents including, for example, U.S. Patent 3,590,000.
- the type of carrier material to be used depends on-many factors such as the type of development used, the quality of the development desired, the type of photoconductive material employed and the like.
- the materials used as carrier surfaces or carrier particles or the coating thereon should have a triboelectric value commensurate with the triboelectric value of the toner in order to generate electrostatic adhesion of the toner to the carrier.
- Carriers should be selected that are not brittle so as to cause flaking of the surface or particle break-up under the forces exerted on the carrier during recycleas such causes undesirable effects and could, for example, be transferred to the copy surface thereby reducing the quality of the final image.
- an electrostatic carrier and toner powder combination in order to develop a latent image comprised of negative electrostatic charges, an electrostatic carrier and toner powder combination must be selected in which the toner is triboelectrically charged positively relative to the granular carrier.
- an electroscopic toner powder and carrier mixture in order to develop a latent image comprised of positive electrostatic charges such as where a selenium photoreceptor is employed, an electroscopic toner powder and carrier mixture must be selected in which the toner is triboelectrically charged negatively relative to the carrier.
- the latent image is formed of negative electrostatic charges such as when employing an organic electrophotosensitive material as the photoreceptor, it is highly desirable to develop the latent image with a positively-charged electroscopic powder and a negatively-charged carrier material.
- the magnitude of the triboelectric charge is important in that, if the charge is too low, the developed copy will be characterized by high print density but resolution will be poor and background areas will be overdeveloped. By the same token, if the triboelectric charge is too high, background areas will not contain unwanted deposits and resolution will be good, but the developed image print density will be too low.
- the carrier material must be one wherein its coating has a high resistance to abrasion and good adhesion properties, it must be capable of triboelectrically charging the toner to the desired polarity, and charge the toner to a level within a range of triboelectric values whereby developed copies of high quality are obtained.
- electrostatographic coated carrier materials has been to a main extent on a trial and error basis. Since certain desirable functional characteristics of carrier materials having coatings are known, it has been somewhat possible to select coating materials for the purpose of determining their potential usefulness as carrier coatings. However, it has not been possible to reliably predict whether any particular coating material is viable or possesses any advantage over another coating material for use as an electrostatographic carrier coating. The only effective means of determining whether any coating material will satisfy the functional characteristics of a carrier material is to actually prepare carrier particles with the coating material and evaluate the product. Thus, even if a coating material is a member of a broad class of generally desirable materials, it may be that the particular coating material is difficult or impossible to coat by normal means or requires a complicated or expensive preparation process.
- carrier coating materials is the class of fluoropolymers as disclosed in U S Patent No 3 7 98 167 .
- carrier particle cores are coated with a substantially-insoluble fluoropolymer or a mixture of a fluoropolymer and a modifying resin in which the fluoropolymer is essentially insoluble.
- the fluoropolymer therein that is, polytetrafluoroethylene or a copolymer thereof, is substantially insoluble, it is applied to the carrier cores by first preparing a suspension or dispersion of the coating material.
- the coating material After coating the carrier cores, the coating material is heated to a temperature sufficiently high, that is, about 400° C., so that the coating will be cured and fused as to adhere to the cores.
- a temperature sufficiently high that is, about 400° C.
- such a coating procedure is multi-step, time-consuming and more expensive than standard coating processes such as dipping or spray-drying a coating solution.
- the carrier particles possess stronger and more negative triboelectric charging characteristics than the untreated coated particles.
- it would be desirable to provide a carrier particle coated with a fluoropolymer but simultaneously provide such a coated carrier particle by a single-step coating operation, such a need exists.
- the present invention is intended to provide a coated carrier material manufacturing technique and product by a single-step coating operation.
- the present invention provides coated carrier core particles as claimed in the appended claims.
- the solution of polyvinylidene fluoride may comprise ec)polymers of polyvinylidene fluoride, or polyblends of polyvinylidene fluoride and another coating material.
- the other coating material is preferably one which possesses strong adhesive properties with respect to metallic carrier core particles and is selected from soluble acrylics such as styrene and alkyl acrylates and methacrylates, for example, copolymers of styrene and methyl methacrylate, terpolymers of styrene, methyl methacrylate and an organosilane; methyl methacrylate and methacrylic acid copolymers, styrene and methacrylic acid copolymers; polymethacrylonitrile and copolymers thereof; acrylonitrile copolymers such as those containing vinylidene chloride; polyvinyl chloride-maleate copolymers; copolymers containing methacrylic acid and salts thereof; polys
- any suitable ratio of polyvinylidene fluoride may be employed with respect to the ratio of the second polymer in the polyblends for the electrostatographic carrier coatings of this invention.
- Typical ratios of the polyvinylidene fluoride to the second polymer include from 5 parts to 95 parts by weight of the polyvinylidene fluoride to from 95 to 5 parts by weight of the second polymer.
- the coating solution is applied to the-carrier core particles to provide them with a thin, substantially continuous coating of polyvinylidene fluoride.
- the coating material comprise a copolymer or polyblend of polyvinylidene fluoride.
- multi-layer coatings may be employed such as coating a primer material on the carrier core particles and then applying the polyvinylidene fluoride coating.
- the polyvinylidene fluoride coating is applied to the carrier core particles by dissolving the coating material in a suitable solvent such as methyl ethyl ketone and dipping, tumbling or spraying the core particles with the coating solution.
- a fluidized bed coating process is employed as typically a more uniform coating is provided to the carrier core particles.
- the core particles are suspended and circulated in an upwardly flowing stream of heated air so that the particles are sprayed by the coating material in a first zone. Then, in a second zone, fhe particles settle through an air stream of lower air velocity where the solvent evaporates to form a thin solid coating on the particles. Successive layers of coating on the particles are obtained by recirculating them through the first and second zones of the fluid bed coating apparatus.
- any suitable coating weight or thickness of polyvinylidene fluoride, copolymer or polyblend thereof, may be employed to coat the carrier core particles.
- a coating having a thickness at least sufficient to form a substantially continuous film on the core particles is preferred because the carrier coating will then possess sufficient thickness to resist abrasion and minimize pinholes which may adversely affect the triboelectric properties of the coated carrier particles, and also in order that the desired triboelectric effect to the carrier is obtained and to maintain a sufficient negative charge on the carrier, the toner being charged positively in such an embodiment so as to allow development of negatively-charged images to occur.
- the carrier coating may comprise from 0.05 microns to 3.0 microns in thickness on the carrier particle.
- the coating should comprise from 0.2 microns to 0.7 microns in thickness on the carrier particle because maximum coating durability, toner impaction resistance, and copy quality are achieved.
- other additives such as plasticizers, reactive or non-reactive resins, dyes, pigments, conductive fillers such as carbon black, wetting agents and mixtures thereof may be mixed with the coating material.
- the carrier core is a magnetizable material, it is possible to provide carrier particles having magnetic properties.
- the triboelectric charge generated on the carrier particles is in the range of between -35 to -60 microcoulombs per gram of toner particles. Since such a triboelectric charge is too high to provide satisfactory developed image print density with conventional toner materials, it has been found that thermal treatment of the coated carrier particles at a temperature of up to about 200 0 C provides coated carrier particles which generate much lower negative triboelectric charging values.
- the thermal treated coated carrier particles of this invention unexpectedly obtain triboelectric charging values in the range of between -11 to -24 microcoulombs per gram of toner material after having been treated at the aforementioned temperature range for between 30 minutes and up to 60 minutes. It was found that the triboelectric charging values of the thus heat-treated coated carrier particles are excellent to provide developed copies having high image print density, high resolution and low background. In addition, the triboelectric charging values of the carrier particles remain stable over extended periods of milling. Further, the magnitude of the change in the triboelectric charging values of the thus-treated coated carrier particles of this invention being on the order of 40 to 70% is unexpected in view of the prior art.
- the thermal treatment conditions employed in modifying the triboelectric charging values of solution coated polyvinylidene fluoride carrier particles are much less stringent.
- the effect on the triboelectric charging values of the coated carrier particles of this invention appears to be independent of the second polymer material or primer used either as a multi-layer or polyblend since they have markedly different triboelectric charging properties.
- any suitable well-known coated or uncoated carrier material may be employed as the core or substrate for the carrier particles of this invention.
- Typical carrier core materials are methyl methacrylate, glass, silicon dioxide, flintshot, ferromagnetic materials such as iron, steel, ferrite, nickel, and mixtures thereof.
- An ultimate coated carrier particle having an average diameter in the range substantially 30 microns to substantially 1,000 microns is preferred because the carrier particle then possesses sufficient density and inertia to avoid adherence to the electrostatic images during the development process.
- Adherence of carrier particles to an electrostatographic drum is undesirable because of the formation of deep scratches on the drum surface during the image transfer and drum cleaning steps, particularly where cleaning is accomplished by a web cleaner such as the web disclosed in U 5 Patent No. 3 186 838.
- any suitable pigmented or dyed toner material may be employed with the carrier particles of this invention.
- Typical toner materials are gum copal, gum sandarac, resin, cumarone-indene resin, asphaltum, gilsonite, phenolformaldehyde resins, resin -modified phenolformaldehyde resins, methacrylic resins, polystyrene resins, epoxy resins, polyester resins, polyethylene resins, vinyl chloride resins, and copolymers or mixtures thereof.
- the particular toner material to be employed depends upon the separation of the toner particles from the carrier particles in the triboelectric series.
- U.S. Patents Nos. 2 659 670, 2 753 308, 2 788 288 and 3 070 342 and U.S. Reissue 25 136 are examples of toner compositions.
- any suitable pigment or dye may be employed as the colorant for the toner particles.
- Colorants for toners are well known and are, for example, carbon black, nigrosine dye, aniline blue, Caleo Oil Blue, chrome yellow, ultramarine blue, Quinoline Yellow, methylene blue chloride, Monastral Blue, Malachite Green Oxalate, lampblack, Rose Bengal, Monastral Red, Sudan Black BN, and mixtures thereof.
- the pigment or dye should be present in the toner in a sufficient quantity to render it highly colored so that it will form a clearly visible image on a recording member.
- Any suitable conventional toner concentration may be employed with the carrier particles of this invention.
- Typical toner concentrations are 1 part toner with 10 to 200 parts by weight of carrier.
- any suitable well-known electrophotosensitive material may be employed as the photoreceptor with the carrier particles of this invention.
- Well-known photoconductive materials are vitreous selenium, organic or inorganic photoconductors embedded in a non-photoconductive matrix, organic or inorganic photoconductors embedded in a photoconductive matrix, or the like.
- Representative patents in which photoconductive materials are disclosed include U.S. Paten.ts2 803 542, 2 970 906, 3 121 006, 3 121 007 and 3 151 982.
- the relative triboelectric values generated by contact of carrier particles with toner particles are measured by means of a Faraday cage.
- This device comprises a stainless steel cylinder having a diameter of about 1 inch and a length of about 1 inch.
- a screen is positioned at each end of the cylinder; the screen openings are of such a size as to permit the toner particles to pass through the openings but prevent the carrier particles from making such passage.
- the Faraday cage is weighed, charged with about 0.5 gram of the carrier particles and toner particles, reweighed, and connected to the input of a coulomb meter. Dry compressed air is then blown through the cylinder to drive all the toner particles from the carrier particles.
- the oppositely-charged carrier particles cause an equal amount of electronic charge to flow from the cage, through the coulomb meter, to ground.
- the coulomb meter measures this charge which is then taken to be the charge on the toner which was removed.
- the cylinder is reweighed to determine the weight of the toner removed.
- the resulting data are used to calculate the toner concentration and the average charge-to-mass ratio of the toner. Since the triboelectric measurements are relative, the measurements should for comparative purposes be conducted under substantially-identical conditions.
- Other suitable toners may be substituted for the toner composition used in the examples.
- a developer mixture was prepared by applying to steel carrier particles having an average diameter of 100 microns a primer material comprising a polyvinyl chloride-maleate copolymer commercially available as Exon 470 from Firestone Plastics Company, Pottstown, Pa.
- the primer material was dissolved to about 5.0% solids by weight in methyl ethyl ketone and applied to the carrier cores in a fluidized bed coating apparatus wherein the bed temperature was limited to between about 40° C and 50° C.
- the primer solution is applied to provide a net coating'weight, by weight of solids, of about 0.3% to the carrier cores.
- the primed carrier particles were then overcoated with a coating solution comprising polyvinylidene fluoride, commercially available as Kynar 201 from Pennwalt Corp., Philadelphia, Pa.
- the coating solution was prepared with methyl ethyl ketone and applied to the carrier particles in the aforementioned coating apparatus maintained at a temperature of between about 40° C and 50° C to provide a net coating weight, by weight of solids, of about 0.3% polyvinylidene fluoride to the primed carrier particles.
- the coated carrier particles are cooled to room temperature and screened to remove agglomerated particles. About 100 parts of the screened carrier particles are mixed with about 1 part of finely-divided toner particles to form a developer mixture.
- the composition of the toner particles comprises a styrene-n-butyl methacrylate copolymer and carbon black.
- the resultant developer mixture was roll-mill mixed for various times and samples taken therefrom after 0.5 and 2.0 hours for measurement of the triboelectric charge generated on the carrier particles as previously indicated. The triboelectric values were found to be about -37 and -60 microcoulombs per gram of toner particles, respectively.
- a fresh sample of the coated carrier particles was then placed in an air circulating oven at about 200° C for about 1 hour. Due to the heat-up time for the glass trays and the carrier particles, the actual treatment time is about 45 minutes. After cooling in air and screening for aggl o mer ates, 100 parts of the treated carrier particles were mixed with 1 part of the toner particles as above. The resultant developer mixture was roll-mill mixed and samples taken therefrom after 0.5 and 2.0 hours for measurement of the triboelectric charge generated on the carrier particles as previously indicated. The triboelectric values were found to be -12 and -12 microcoulombs per gram of toner particles, respectively.
- a developer mixture was prepared by applying to steel carrier particles as in Example I a primer material comprising an acrylic primer, commercially available as BFG 1104 from B. F. Goodrich Company, Akron, Ohio.
- the primer material was diluted with methyl ethyl ketone to about 26.0% solids by weight and applied to the carrier cores in a fluidized bed coating apparatus wherein the bed temperature was limited to between about 40° C and 50° C.
- the primer solution was applied to provide a net coating weight, by weight of solids, of about 0.3% to the carrier cores.
- the primed carrier particles were then overcoated with a coating solution comprising polyvinylidene fluoride-
- the coating solution was prepared with methyl ethyl ketone and applied to the carrier particles in the aforementioned coating apparatus maintained at a temperature of between about 40° C and 50° C to provide a net coating weight, by weight of solids, of about 0.6% polyvinylidene fluoride to the primed carrier particles.
- Example II After screening to remove any agglomerates, about 100 parts of the coated carrier particles were mixed with about 1 part of the toner particles of Example I. The resultant developer mixture was roll-mill mixed for various times and samples taken therefrom after 0.5 and 2.0 hours for measurement of the triboelectric charge generated on the carrier particles as previously indicated. The triboelectric values were found to be -29 and -36 microcoulombs per gram of toner particles, respectively.
- a fresh sample of the coated carrier particles was then placed in an air circulating oven at about 200° C for about 1 hour. Due to the heat-up time for the glass trays and the carrier particles, the actual treatment time is about 45 minutes. After cooling in air and screening for agglomerates, about 100 parts of the treated carrier particles were mixed with about 1 part of the toner particles of Example I. The resultant developer mixture was roll-mill mixed and samples taken therefrom after 0.5 and 2.0 hours for measurement of the triboelectric charge generated on the carrier particles as previously indicated. The triboelectric values were found to be -16 and -20 microcoulombs per gram of toner particles, respectively.
- a developer mixture was prepared by applying to steel carrier particles as in Example I a coating composition comprising a blend of a polyvinyl chloride-maleate copolymer mixed with polyvinylidene fluoride.
- the coating composition was dissolved in methyl ethyl ketone and blended as to provide a net coating weight, by weight of solids, of the polyvinyl chloride-maleate copolymer and of the polyvinylidene fluoride, of 0.5% and 0.3%, respectively.
- a fresh sample of the coated carrier particles was then placed in an air circulating oven at about 200° C for about I hour. Due to the heatup time for the glass trays and the carrier particles, the actual treatment time is about 45 minutes. After cooling in air and screening for agglomerates, about 100 parts of the treated carrier particles were mixed with about 1 part of the toner particles of Example L The resultant developer mixture was roll-mill mixed and samples taken therefrom after about 0.5 and 2.0 hours for measurement of the triboelectric charge generated on the carrier particles as previously indicated. The triboelectric values were found to be -10 and -9 microcoulombs per gram of toner particles, respectively.
- a developer mixture was prepared by applying to steel carrier particles as in Example I a coating composition comprising a blend of a polyvinyl chloride-maleate copolymer mixed with polyvinylidene fluoride.
- the coating composition was dissolved in methyl ethyl ketone and blended as to provide a net coating weight, by weight of solids, of the polyvinyl chloride-maleate copolymer and of the polyvinylidene fluoride, of 0.4% and 0.4%, respectively.
- a fresh sample of the coated carrier particles was then placed in an air circulating oven at about 200° C for about I hour. Due to the heat-up time for the glass trays and the carrier particles, the actual treatment time is about 45 minutes. After cooling in air and screening for agglomerates, about 100 parts of the treated carrier particles were mixed with about 1 part of the toner particles of Example I. The resultant developer mixture was roll-mill mixed and samples taken therefrom after about 0.5 and 2.0 hours for measurement of the triboelectric charge generated on the carrier particles as previously indicated. The triboelectric values were found to be -16 and -19 microcoulombs per gram of toner particles, respectively.
- a ⁇ developer mixture was prepared by applying to steel carrier particles as in Example I a coating composition comprising a blend of a polyvinyl chloride-maleate copolymer mixed with polyvinylidene fluoride.
- the coating composition was dissolved in methyl ethyl ketone and blended as to provide a net coating weight, by weight of solids, of the polyvinyl chloride-maleate copolymer and of the polyvinylidene fluoride, of 0.2% and 0.6%, respectively.
- a fresh sample of the coated carrier particles was then placed in an air circulating oven at about 200° C for about I hour. Due to the heat-up time for the glass trays and the carrier particles, the actual treatment time is about 45 minutes. After cooling in air and screening for agglomerates, about 100 parts of the treated carrier particles were mixed with about I part of the toner particles of Example I. The resultant developer mixture was roll-mill mixed and samples taken therefrom after about 0.5 and 2.0 hours for measurement of the triboelectric charge generated on the carrier particles as previously indicated. The triboelectric values were found to be about -21 and -23 microcoulombs per gram of toner particles, respectively.
- the adhesion properties of electrostatographic carrier particles coated with polyvinylidene fluoride may be substantially improved by employing a priming material in multi-layer or polyblend fashion.
- the triboelectric properties of polyvinylidene fluoride coated carrier particles may be modified by a modest post-treatment step as to lower the unacceptably high range of triboelectric values obtained therewith of from between -35 to -60 microcoulombs per gram of toner material to a lower and satisfactory range of between -11 and -24 microcoulombs per gram of toner material as to provide maximum copy quality.
- the polyvinylidene fluoride coatings may be applied as a solution compared to a solid particle fusion procedure for other fluoropolymers such as polytetrafluoroethylene and copolymers thereof.
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- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Spectroscopy & Molecular Physics (AREA)
- Developing Agents For Electrophotography (AREA)
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US11606780A | 1980-01-28 | 1980-01-28 | |
US116067 | 1980-01-28 |
Publications (1)
Publication Number | Publication Date |
---|---|
EP0034423A1 true EP0034423A1 (fr) | 1981-08-26 |
Family
ID=22365031
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP19810300373 Ceased EP0034423A1 (fr) | 1980-01-28 | 1981-01-28 | Procédé de fabrication de particules véhiculatrices revêtues pour des mélanges de développement électrostatographique |
Country Status (3)
Country | Link |
---|---|
EP (1) | EP0034423A1 (fr) |
JP (1) | JPS56113146A (fr) |
CA (1) | CA1148785A (fr) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0532320A1 (fr) * | 1991-09-10 | 1993-03-17 | Xerox Corporation | Compositions de développateur |
EP0645681A1 (fr) * | 1993-09-24 | 1995-03-29 | Eastman Kodak Company | Méthode pour modifier la propension de charge de particules porteuses pour un révélateur électrostatographic, et particules porteuses modifiés |
EP0767412A1 (fr) * | 1995-10-05 | 1997-04-09 | Nashua Corporation | Particules d'agent de véhiculation revêtues, contenant un agent de contrÔle de charge |
Families Citing this family (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH0719080B2 (ja) * | 1985-10-30 | 1995-03-06 | ゼロックス コ−ポレ−ション | キャリヤー粒子の製造方法 |
JP2759464B2 (ja) * | 1988-11-16 | 1998-05-28 | キヤノン株式会社 | 二成分系現像剤および該現像剤を用いた現像方法 |
EP0704472B1 (fr) * | 1991-02-20 | 2000-08-16 | Fuji Xerox Co., Ltd. | Véhiculeur pour le développement d'images latentes électrostatiques, et procédé pour sa préparation |
US5275902A (en) * | 1991-02-20 | 1994-01-04 | Fuji Xerox Co., Ltd. | Developer composition for electrophotography |
US5223369A (en) * | 1992-03-16 | 1993-06-29 | Xerox Corporation | Process for coating carrier particles |
JP3397483B2 (ja) * | 1993-12-29 | 2003-04-14 | キヤノン株式会社 | 電子写真用キャリア,その製造方法,二成分系現像剤及び画像形成方法 |
US5516615A (en) * | 1995-01-31 | 1996-05-14 | Eastman Kodak Company | Stabilized carriers with β phase poly(vinylidenefluoride) |
Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2014876A (en) * | 1978-01-26 | 1979-09-05 | Xerox Corp | Coated carrier particles |
-
1980
- 1980-11-19 CA CA000365022A patent/CA1148785A/fr not_active Expired
-
1981
- 1981-01-21 JP JP779281A patent/JPS56113146A/ja active Pending
- 1981-01-28 EP EP19810300373 patent/EP0034423A1/fr not_active Ceased
Patent Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2014876A (en) * | 1978-01-26 | 1979-09-05 | Xerox Corp | Coated carrier particles |
Non-Patent Citations (3)
Title |
---|
PRODUCT LICENSING INDEX, August 1972, No. 100, art. No. 10029 HAMPSHIRE (GB) "Method of and apparatus for fluidized bed coating of electrophotographic toner carrier particles" pages 69-71 * page 69, column 2, paragraphs 2-4; page 71, the examples * * |
RESEARCH DISCLOSURE, April 1974, No. 120, art. No. 12050 HAMPSHIRE (GB) G. NEUNER: "Treating iron carrier particles for electrography" page 28 * Entire article * * |
RESEARCH DISCLOSURE, June 1974, No. 122, art. No. 12243 HAMPSHIRE (GB) A.E. FIELDS: "Carrier particles for use in electrographic developer composition" pages 35-36 * The whole article * * |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0532320A1 (fr) * | 1991-09-10 | 1993-03-17 | Xerox Corporation | Compositions de développateur |
EP0645681A1 (fr) * | 1993-09-24 | 1995-03-29 | Eastman Kodak Company | Méthode pour modifier la propension de charge de particules porteuses pour un révélateur électrostatographic, et particules porteuses modifiés |
EP0767412A1 (fr) * | 1995-10-05 | 1997-04-09 | Nashua Corporation | Particules d'agent de véhiculation revêtues, contenant un agent de contrÔle de charge |
US5627001A (en) * | 1995-10-05 | 1997-05-06 | Nashua Corporation | Coated carrier particle containing a charge control agent |
Also Published As
Publication number | Publication date |
---|---|
CA1148785A (fr) | 1983-06-28 |
JPS56113146A (en) | 1981-09-05 |
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Legal Events
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PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
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Effective date: 19811008 |
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Inventor name: WLOCHOWSKI, JAN MARIA Inventor name: HORTON, PHILIP G. |