US4880720A
Expired / Lapsed
US
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Liquid developer compositions
Assignee: Xerox Corp
•
Filing: 1988-05-23
•
Granted: 1989-11-14
•
Expires: 2008-05-23
Abstract
Abstract Disclosed is an electrophotographic liquid developer composition comprising a liquid medium, first toner particles charged to one polarity and comprising a resin and a first pigment, second toner particles charged to a polarity opposite to that of the first toner particles and comprising a resin and a second pigment of a color different from that of the first pigment, and a charge director. The disclosed developer is suitable for developing electrostatic latent images in two different colors in a single development step. The latent image comprises three areas of charge; toner particles of one color are selectively attracted to one area, toner particles of the other color are selectively attracted to the second area, and the third area remains undeveloped as a background area.
Inventors
- 👤 Stephan Drappel
- 👤 Raymond W. Wong
- 👤 Melvin D. Croucher
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 11:55
CPC Classifications
G; G03; G03G; G03G9/00; G03G9/08; G03G9/12; G03G9/122
Claims Analysis
Total Claims: 40
Claim 1
Independent Claim
74 words
An electrophotographic liquid developer composition comprising a liquid medium, first toner particles charged to one polarity and comprising a resin and a first pigment, second toner particles charged to a polarity opposite to that of the first toner particles and comprising a resin and a second pigment different in color from the first pigment, and a charge director, wherein the first toner particles and the second toner particles are contained within the liquid medium.
Claim 2
Dependent Claim
74 words
An electrophotographic liquid developer composition comprising a liquid medium, first toner particles charged to one polarity and comprising a resin and a first pigment, second toner particles charged to a polarity opposite to that of the first toner particles and comprising a resin and a second pigment different in color from the first pigment, and a charge director, wherein the first toner particles and the second toner particles are contained within the liquid medium.
Claim 3
Dependent Claim
31 words
An electrophotographic liquid developer composition according to claim 1 wherein said first toner particles and said second toner particles are from about 0.1 to about 8 microns in average volume diameter.
Claim 4
Dependent Claim
26 words
An electrophotographic developer composition according to claim 1 wherein said liquid medium is a high purity aliphatic hydrocarbon comprising from 1 to about 25 carbon atoms.
Claim 5
Dependent Claim
20 words
An electrophotographic developer composition according to claim 1 wherein said liquid medium has a viscosity of less than 2 centipoise.
Claim 6
Dependent Claim
30 words
An electrophotographic developer composition according to claim 1 wherein said liquid medium is selected from the group consisting of Isopar® G, Isopar® H, Isopar® K, Isopar® L, and Isopar® M.
Claim 7
Dependent Claim
47 words
An electrophotographic developer composition according to claim 1 wherein said first toner particles comprise a resin selected from the group consisting of copolymers of polyethylene, copolymers of polypropylene, ethylene-vinyl acetate copolymers, copolymers of ethylene and acrylic acid, copolymers of ethylene and methacrylic acid, chlorinated polyolefins, and poly-α-olefins.
Claim 8
Dependent Claim
27 words
An electrophotographic developer composition according to claim 1 wherein said first toner particles comprise a resin selected from the group consisting of poly(ethylene-co-methacrylic) acid and chlorinated polypropylenes.
Claim 9
Dependent Claim
49 words
An electrophotographic developer composition according to claim 1 wherein said second toner particles comprise a resin selected from the group consisting of polyethylene, polypropylene, copolymers of polyethylene, copolymers of polypropylene, ethylene-vinyl acetate copolymer, copolymers of ethylene and acrylic acid, copolymers of ethylene and methacrylic acid, chlorinated polyolefins, and poly-α-olefins.
Claim 10
Dependent Claim
27 words
An electrophotographic developer composition according to claim 1 wherein said second toner particles comprise a resin selected from the group consisting of poly(ethylene-co-methacrylic acid and chlorinated polypropylenes.
Claim 11
Dependent Claim
54 words
An electrophotographic developer composition according to claim 1 wherein said first toner particles and said second toner particles comprise a resin selected from the group consisting of polyethylene, polypropylene, copolymers of polyethylene, copolymers of polypropylene, ethylene-vinyl acetate copolymer, copolymers of ethylene and acrylic acid, copolymers of ethylene and methacrylic acid, chlorinated polyolefins, and poly-a-olefins.
Claim 12
Dependent Claim
32 words
An electrophotographic developer composition according to claim 1 wherein said first toner particles and said second toner particles comprise a resin selected from the group consisting of poly(ethylene-co-methacrylic) acid and chlorinated polypropylenes.
Claim 13
Dependent Claim
31 words
An electrophotographic developer composition according to claim 1 wherein said first toner particles comprise a pigment selected from the group consisting of Toner 8200, Hostaperm Pink E, and Lithol Rubine DCC-2734.
Claim 14
Dependent Claim
28 words
An electrophotographic developer composition according to claim 1 wherein said second toner particles comprise a pigment selected from the group consisting of Mogul L and Sudan Blue OS.
Claim 15
Dependent Claim
51 words
An electrophotographic developer composition according to claim 1 wherein said first toner particles comprise a pigment selected from the group consisting of Toner 8200, Hostaperm Pink E, and Lithol Rubine DCC-2734, and said second toner particles comprise a pigment selected from the group consisting of Mogul L and Sudan Blue OS.
Claim 16
Dependent Claim
60 words
An electrophotographic developer composition according to claim 1 wherein said first toner particles and said second toner particles comprise a resin present in an amount of from about 60 to about 95 percent by weight of the toner particles, and a pigment present in an amount of from about 5 to about 40 percent by weight of the toner particles.
Claim 17
Dependent Claim
38 words
An electrophotographic developer composition according to claim 1 wherein said first toner particles and said second toner particles are present in a total amount of from about 0.5 to about 8 percent by weight of the developer composition.
Claim 18
Dependent Claim
28 words
An electrophotographic developer composition according to claim 1 wherein said charge director is selected from the group consisting of iron naphthenate, lecithin, basic barium petronate, and zirconium octoate.
Claim 19
Dependent Claim
35 words
An electrophotographic developer composition according to claim 1 wherein said charge director is present in an amount of from about 0.5 to about 10 percent by weight of the solids content of the developer composition.
Claim 20
Dependent Claim
24 words
An electrophotographic developer composition according to claim 1 wherein said first toner particles are positively charged and said second toner particles are negatively charged.
Claim 21
Dependent Claim
42 words
An electrophotographic developer composition according to claim 19 wherein said first toner particles are charged to from about +80 to about +120 microcoulombs per gram, and said second toner particles are charged to from about -80 to about -120 microcoulombs per gram.
Claim 22
Dependent Claim
24 words
An electrophotographic developer composition according to claim 1 wherein said first toner particles are negatively charged and said second toner particles are positively charged.
Claim 23
Dependent Claim
42 words
An electrophotographic developer composition according to claim 21 wherein said first toner particles are charged to from about -80 to about -120 microcoulombs per gram, and said second toner particles are charged to from about +80 to about +120 microcoulombs per gram.
Claim 24
Dependent Claim
60 words
An electrophotographic liquid developer composition consisting essentially of a liquid medium, first toner particles charged to one polarity and comprising a resin and a first pigment, second toner particles charged to a polarity opposite to that of the first toner particles and comprising a resin and a second pigment different in color from the first pigment, and a charge director.
Claim 25
Dependent Claim
60 words
An electrophotographic liquid developer composition consisting essentially of a liquid medium, first toner particles charged to one polarity and comprising a resin and a first pigment, second toner particles charged to a polarity opposite to that of the first toner particles and comprising a resin and a second pigment different in color from the first pigment, and a charge director.
Claim 26
Dependent Claim
54 words
An electrophotographic developer composition according to claim 23 wherein said first toner particles and said second toner particles comprise a resin selected from the group consisting of polyethylene, polypropylene, copolymers of polyethylene, copolymers of polypropylene, ethylene-vinyl acetate copolymer, copolymers of ethylene and acrylic acid, copolymers of ethylene and methacrylic acid, chlorinated polyolefins, and poly-α-olefins.
Claim 27
Dependent Claim
32 words
An electrophotographic developer composition according to claim 23 wherein said first toner particles and said second toner particles comprise a resin selected from the group consisting of poly(ethylene-co-methacrylic) acid and chlorinated polypropylenes.
Claim 28
Dependent Claim
28 words
An electrophotographic developer composition according to claim 23 wherein said charge director is selected from the group consisting of iron naphthenate, lecithin, basic barium petronate, and zirconium octoate.
Claim 29
Dependent Claim
35 words
An electrophotographic developer composition according to claim 23 wherein said charge director is present in an amount of from about 0.5 to about 10 percent by weight of the solids content of the developer composition.
Claim 30
Dependent Claim
60 words
An electrophotographic developer composition according to claim 23 wherein said first toner particles and said second toner particles comprise a resin present in an amount of from about 60 to about 95 percent by weight of the toner particles and a pigment present in an amount of from about 5 to about 40 percent by weight of the toner particles.
Claim 31
Dependent Claim
38 words
An electrophotographic developer composition according to claim 23 wherein said first toner particles and said second toner particles are present in a total amount of from about 0.5 to about 8 percent by weight of the developer composition.
Claim 32
Dependent Claim
30 words
An electrophotographic developer composition according to claim 23 wherein said first toner particles and said second toner particles are from about 0.1 to about 8 microns in average volume diameter.
Claim 33
Dependent Claim
63 words
An electrophotographic liquid developer composition consisting essentially of a liquid medium, first toner particles charged to one polarity and comprising a resin and a first pigment, second toner particles charged to a polarity opposite to that of the first toner particles and comprising a resin and a second pigment different in color from the first pigment, a charge director, and a charge adjuvant.
Claim 34
Dependent Claim
63 words
An electrophotographic liquid developer composition consisting essentially of a liquid medium, first toner particles charged to one polarity and comprising a resin and a first pigment, second toner particles charged to a polarity opposite to that of the first toner particles and comprising a resin and a second pigment different in color from the first pigment, a charge director, and a charge adjuvant.
Claim 35
Dependent Claim
16 words
An electrophotographic developer composition according to claim 1 wherein the developer also contains a charge adjuvant.
Claim 36
Dependent Claim
92 words
An electrophotographic liquid developer composition according to claim 1 wherein the first toner particles and the second toner particles contain a resin selected from the group consisting of a poly(ethylene-co-methacrylic acid) copolymer and a chlorinated polypropylene, the charge director is selected from the group consisting of lecithin and iron naphthenate, the first toner particles contain a pigment selected from the group consisting of carbon black and Sudan Blue OS, and the second toner particles contain a pigment selected from the group consisting of Lithol Rubine DCC-2734, Toner 8200, and Hostaperm Pink E.
Claim 37
Dependent Claim
48 words
An electrophotographic liquid developer composition according to claim 1 wherein the first and second toner particles contain a poly(ethylene-co-methacrylic acid) copolymer resin, the first toner particles contain a carbon black pigment, the second toner particles contain a Lithol Rubine DCC-2734 pigment, and the charge director is iron naphthenate.
Claim 38
Dependent Claim
47 words
An electrophotographic liquid developer composition according to claim 1 wherein the first and second toner particles contain a poly(ethylene-co-methacrylic acid) copolymer resin, the first toner particles contain a Toner 8200 pigment, the second toner particles contain a Sudan Blue OS pigment, and the charge director is lecithin.
Claim 39
Dependent Claim
49 words
An electrophotographic liquid developer composition according to claim 1 wherein the first and second toner particles contain a poly(ethylene-co-methacrylic acid) copolymer resin, the first toner particles contain a Hostaperm Pink E pigment, the second toner particles contain a Sudan Blue OS pigment, and the charge director is iron naphthenate.
Claim 40
Dependent Claim
47 words
An electrophotographic liquid developer composition according to claim 1 wherein the first and second toner particles contain a chlorinated polypropylene resin, the first toner particles contain a carbon black pigment, the second toner particles contain a Hostaperm Pink E pigment, and the charge director is iron naphthenate.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-11-13 | 1993-05-15 | 1993-11-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-11-13 | 1997-05-15 | 1997-11-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-11-13 | 2001-05-15 | 2001-11-14 | $7700.00 | Window Closed / Lapsed |