US5077168A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Toner for electrophotography and process for preparation thereof
Assignee: Kyocera Mita Industrial Co Ltd
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Filing: 1989-12-28
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Granted: 1991-12-31
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Expires: 2009-12-28
Abstract
Abstract Disclosed is a toner for the electrophotography, which comprises as a main component a styrene/acrylic copolymer having at least two molecular weight distribution peaks, the molecular weight (Mw) of the peak on the lowest molecular weight side being lower than 13000, wherein the toner contains a charge controlling agent dispersed therein at a concentration of at least 0.3% by weight and the charge controlling agent has such a particle size distribution that the area ratio of particles having a particle size larger than 2.5 μm is at least 80% based on the section of the toner. If this toner is used, the fixing-possible temperature can be broadened while increasing the fixing ratio without reduction of the performances of the toner.
Inventors
- 👤 Shunsuke Ogami
- 👤 Atsushi Yamaguchi
- 👤 Hidenori Asada
- 👤 Masanori Fujii
- 👤 Hiroshi Komata
- 👤 Kiminori Umeda
- 👤 Takahiko Kimura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 12:23
CPC Classifications
G; G03; G03G; G03G9/00; G03G9/08; G03G9/097; G03G9/087; G03G9/08702; G03G9/08726; G03G9/08728; G03G9/09; G03G9/0906; G03G9/091; G03G9/09783
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
101 words
A toner for the electrophotography, which comprises as a main component a styrene/acrylic copolymer having at least two molecular weight distribution peaks, the molecular weight (Mw) of the peak on the lowest molecular weight side being lower than 13000, wherein the toner contains a charge controlling agent which is a metal-containing complex salt dye dispersed therein at a concentration of at least 0.3% by weight and the charge controlling agent has such a particle size distribution that the area ratio of particles having a particle size larger than 2.5 μm is at least 80% based on the section of the toner.
Claim 2
Dependent Claim
101 words
A toner for the electrophotography, which comprises as a main component a styrene/acrylic copolymer having at least two molecular weight distribution peaks, the molecular weight (Mw) of the peak on the lowest molecular weight side being lower than 13000, wherein the toner contains a charge controlling agent which is a metal-containing complex salt dye dispersed therein at a concentration of at least 0.3% by weight and the charge controlling agent has such a particle size distribution that the area ratio of particles having a particle size larger than 2.5 μm is at least 80% based on the section of the toner.
Claim 3
Dependent Claim
22 words
A toner as set forth in claim 1, wherein the metal-containing complex salt dye is a 1:2 type chromium complex salt dye.
Claim 4
Dependent Claim
24 words
A toner as set forth in claim 1, wherein the charge controlling agent is contained in an amount of 0.5 to 5% by weight.
Claim 5
Dependent Claim
35 words
A toner as set forth in claim 1, wherein the styrene/acrylic copolymer has a molecular weight (Mw) of 300000 to 700000 at the peak on the high molecular weight side of the molecular weight distribution.
Claim 6
Dependent Claim
20 words
A toner as set forth in claim 1, wherein the styrene/acrylic copolymer has a dispersion (Mw/Mn) of 16 to 17.
Claim 7
Dependent Claim
27 words
A toner as set forth in claim 1, wherein the styrene/acrylic copolymer comprises styrene and an acrylic monomer at a molar ratio of from 60/40 to 98/2.
Claim 8
Dependent Claim
18 words
A toner as set forth in claim 1, which has a particle size of 5 to 35 microns.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-12-30 | 1995-07-01 | 1995-12-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-12-30 | 1999-07-01 | 1999-12-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-12-30 | 2003-07-01 | 2003-12-31 | $7700.00 | Window Closed / Lapsed |