GB1390871A - Electrographic developers - Google Patents
Electrographic developersInfo
- Publication number
- GB1390871A GB1390871A GB1255173A GB1255173A GB1390871A GB 1390871 A GB1390871 A GB 1390871A GB 1255173 A GB1255173 A GB 1255173A GB 1255173 A GB1255173 A GB 1255173A GB 1390871 A GB1390871 A GB 1390871A
- Authority
- GB
- United Kingdom
- Prior art keywords
- particles
- acid
- carboxylic acid
- copolymer
- carrier
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
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
- G03G9/1132—Macromolecular components of coatings
- G03G9/1133—Macromolecular components of coatings obtained by reactions only involving carbon-to-carbon unsaturated bonds
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
- H01F1/01—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
- H01F1/03—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity
- H01F1/12—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials
- H01F1/14—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials metals or alloys
- H01F1/20—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials metals or alloys in the form of particles, e.g. powder
- H01F1/22—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials metals or alloys in the form of particles, e.g. powder pressed, sintered, or bound together
- H01F1/24—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials metals or alloys in the form of particles, e.g. powder pressed, sintered, or bound together the particles being insulated
- H01F1/26—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials metals or alloys in the form of particles, e.g. powder pressed, sintered, or bound together the particles being insulated by macromolecular organic substances
Landscapes
- Physics & Mathematics (AREA)
- Chemical & Material Sciences (AREA)
- Spectroscopy & Molecular Physics (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Physics & Mathematics (AREA)
- Dispersion Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Developing Agents For Electrophotography (AREA)
Abstract
1390871 Coated particles EASTMAN KODAK CO 15 March 1973 [21 March 1972 (3)] 12551/73 Heading B2E [Also in Division G2] A magnetically attractable particulate carrier vehicle for electrographic developer compositions comprises either (A) carrier particles having cores of magnetically attractable material coated with a composition comprising a metal ion-containing alpha-olefine-carboxylic acid copolymer in which the alphaolefine is of formula RCH-CH in which R is hydrogen or alkyl and the carboxylic acid is alpha, beta-ethylenically unsaturated carboxylic acid and in which 10-90% of the carboxylic groups are in metal ion-salt form; or (B) carrier particles having cores of magnetically attractable material coated with a composition comprising a terpolymer formed from (1) vinylidene chloride, (2) acrylonitrile, methacrylonitrile or an alkyl ester of acrylic or methacrylic acid having 1-18 carbon atoms in the alkyl group, and (3) an organic compound containing a vinyl group and a carboxylic acid or sulphonic acid group; or (C) a mixture of carrier particles of types A and B. An electrographic developer composition comprises a mixture of 1-10 weight percent of electroscopic toner particles and 90-99 weight percent of carrier particles, the carrier vehicle being either (A) or (B) or (C). The composition is especially suitable for magnetic-brush development and enables the production of acceptable solid area images within a wide range of exposure attitude. The coatings may also contain finely-divided electronically - conductive particles such as carbon black. The alpha-olefine in A preferably contains an alkyl group having 1-8 carbon atoms, e.g. ethylene, propylene, butene-1, pentene-1, hexene-1, heptene-1, 3-methylbutene-1 and 4-methylpentene-1 and is preferably present in the copolymer in amount at least 50 mole percent. Preferably the carboxylic acid in A has 3-8 carbon atoms, e.g. acrylic, methacrylic, ethacrylic, itaconic, maleic, fumaric acid and esters and anhydrides thereof. The preferred metal ions are alkali metal ions. Preferred copolymers in (A) have a free acid content of less than 2 milliequivalents of 1 normal sodium hydroxide per gram of the copolymer. The preferred copolymer of (B) is a vinylidene chloride-acrylonitrileacrylic acid terpolymer containing 5-30% acrylonitrile, 2-25% by weight of acrylic acid and 55-93% vinylidene chloride. Preferably the carrier vehicle comprises 20-95% by weight of core particles (A) and from 80- 5% by weight of core particles (B). The coatings may be applied by fluidised bed, dipping, spraying, brushing. The core materials may be iron, nickel, cobalt or an alloy or mixture thereof. The core may consist of solid particles of magnetic material or may be non- magnetic particles overcoated with ferromagnetic materials, rough-surfaced or smooth-surfaced magnetically responsive particles. The toner material comprises a resin binder and a colourant. The resin may be a natural resin, e.g. balsam, calophony, shellac, colophonymodified phenol resins, synthetic resins, e.g. polycarbonates, polyvinyl chloride, poylvinylidene chloride, polyvinyl acetate, polyvinyl acetals, polyvinyl ether, polyacrylic and polymethacrylic esters, polystyrene, polyesters of phenol-formaldehyde resins, ketone resins, polyamides, polyurethanes, chlorinated rubber, polyolefines. Examples of colourants are given.
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US23676572A | 1972-03-21 | 1972-03-21 | |
US23658472A | 1972-03-21 | 1972-03-21 | |
US23661472A | 1972-03-21 | 1972-03-21 |
Publications (1)
Publication Number | Publication Date |
---|---|
GB1390871A true GB1390871A (en) | 1975-04-16 |
Family
ID=27398879
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB1255173A Expired GB1390871A (en) | 1972-03-21 | 1973-03-15 | Electrographic developers |
Country Status (2)
Country | Link |
---|---|
FR (1) | FR2176899B1 (en) |
GB (1) | GB1390871A (en) |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0512537B1 (en) * | 1991-05-08 | 1997-01-02 | Mitsubishi Chemical Corporation | Developer for developing an electrostatic latent image and electrophotographic developing process |
JPH09185185A (en) * | 1995-12-29 | 1997-07-15 | Hoechst Ind Kk | Electrostatic charge image developing coated carrier |
-
1973
- 1973-03-15 GB GB1255173A patent/GB1390871A/en not_active Expired
- 1973-03-20 FR FR7309823A patent/FR2176899B1/fr not_active Expired
Also Published As
Publication number | Publication date |
---|---|
FR2176899B1 (en) | 1978-04-28 |
FR2176899A1 (en) | 1973-11-02 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
PS | Patent sealed | ||
PCNP | Patent ceased through non-payment of renewal fee |