US4434220A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrophotographic toner and carrier
Assignee: IBM Information Products Corp
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Filing: 1982-07-15
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Granted: 1984-02-28
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Expires: 2002-07-15
Abstract
Abstract A developer material comprising toner particles and coated carrier beads for use in developing images in an electrostatographic device is disclosed. The toner particles are initially classified according to a size distribution wherein less than 15% by weight are greater than 16 microns, between 7 and 15% by weight are less than 5 microns, the remainder being from 5 to 16 microns; and wherein the median particle size by weight is from 8 to 12 microns. The carrier beads have a core with a coating thereon. The coating is a mixed resin system comprising 5 to 55% by weight polytetrafluoroethylene, 5 to 55% by weight fluorinated polyethylene-propylene, and 40% to 80% by weight of a poly(amide-imide) resin which is stable up to at least 600 DEG F., triboelectrically negative (with respect to the herein described toner), nonspalling, essentially nonfriable and dispersible with the other resin components. Also, preferably the coating includes a pigment, such as TiO2, dispersed in the resin system. More specific ranges of size classification of the toner particles and preferred ranges of resin components are also disclosed.
Inventors
- 👤 Jerry J. Abbott
- 👤 Stephen C. Crossan
- 👤 Sterritt R. Fuller, Jr.
- 👤 Paul D. Jachimiak
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 23:18
CPC Classifications
G; G03; G03G; G03G9/00; G03G9/08; G03G9/10; G03G9/113; G03G9/1132; G03G9/1135; G03G9/1139
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
150 words
A developer mix of toner particles and carrier beads for use in electrostatic copying having magnetic brush development, comprising; toner particles having a size distribution wherein less than 15% by weight are greater than 16 microns in size, from 7% to 15% by weight are less than 5 microns in size, the remainder being from 5 to 16 microns in size, the particles median size by weight being 8 to 12 microns in size; and carrier beads having a magnetic core and a coating on said core, said coating having a resin system comprised of about 16% to about 20% by weight of polytetrafluoroethylene, about 9% to about 20% by weight fluorinated polyethylene-propylene, and about 59% to about 62% by weight of a poly (amide-imide) which is stable up to at least 600° F., triboelectrically negative, nonspalling, essentially nonwearing, dispersible with respect to the other resin components, and essentially nonfriable.
Claim 2
Dependent Claim
150 words
A developer mix of toner particles and carrier beads for use in electrostatic copying having magnetic brush development, comprising; toner particles having a size distribution wherein less than 15% by weight are greater than 16 microns in size, from 7% to 15% by weight are less than 5 microns in size, the remainder being from 5 to 16 microns in size, the particles median size by weight being 8 to 12 microns in size; and carrier beads having a magnetic core and a coating on said core, said coating having a resin system comprised of about 16% to about 20% by weight of polytetrafluoroethylene, about 9% to about 20% by weight fluorinated polyethylene-propylene, and about 59% to about 62% by weight of a poly (amide-imide) which is stable up to at least 600° F., triboelectrically negative, nonspalling, essentially nonwearing, dispersible with respect to the other resin components, and essentially nonfriable.
Claim 3
Dependent Claim
21 words
The invention as defined in claim 1 wherein there is about 20% polytetrafluoroethylene, about 20% fluorinated polyethylene-propylene, and about 60% poly(amide-imide).
Claim 4
Dependent Claim
25 words
The invention as defined in claim 1 wherein there is incorporated in the resin system a pigment to modify the triboelectric properties of the resin.
Claim 5
Dependent Claim
14 words
The invention as defined in claim 3 wherein the pigment is TiO 2 .
Claim 6
Dependent Claim
16 words
The invention as defined in claim 4 wherein there is about 9% TiO 2 by weight.
Claim 7
Dependent Claim
23 words
The invention as defined in claim 1 wherein said poly(amide-imide) resin is a copolymer of at least one anhydride and an organic bis-amine.
Claim 8
Dependent Claim
22 words
The invention as defined in claim 6 wherein the anhydride includes at least one from the group trimellitic anhydride and pyromellitic anhydride.
Claim 9
Dependent Claim
12 words
The invention as defined in claim 7 wherein the bis-amine is 4,4'-bis-amino-diphenylmethane.
Claim 10
Dependent Claim
156 words
An equilibrated developer mix of toner particles and carrier beads for use in electrostatic copying having magnetic brush development, comprising; toner particles having a size distribution wherein less than 12% by weight are greater than 16 microns in size, from 15% to 30% by weight are less than 5 microns in size, the remainder being from 5 to 16 microns in size, the particles median size by weight being 6.5 to 9.5 microns in size; carrier beads having a magnetic core and a coating on said core, said coating having a resin system comprised of about 16% to about 20% by weight of polytetrafluoroethylene, about 9% to about 20% by weight fluorinated polyethylene-propylene, and about 59% to about 62% by weight of a poly(amide-imide) which is stable up to at least 600° F., triboelectrically negative (with respect to the herein described toner), nonspalling, essentially nonwearing, dispersible with respect to the other resin components, and essentially nonfriable.
Claim 11
Dependent Claim
156 words
An equilibrated developer mix of toner particles and carrier beads for use in electrostatic copying having magnetic brush development, comprising; toner particles having a size distribution wherein less than 12% by weight are greater than 16 microns in size, from 15% to 30% by weight are less than 5 microns in size, the remainder being from 5 to 16 microns in size, the particles median size by weight being 6.5 to 9.5 microns in size; carrier beads having a magnetic core and a coating on said core, said coating having a resin system comprised of about 16% to about 20% by weight of polytetrafluoroethylene, about 9% to about 20% by weight fluorinated polyethylene-propylene, and about 59% to about 62% by weight of a poly(amide-imide) which is stable up to at least 600° F., triboelectrically negative (with respect to the herein described toner), nonspalling, essentially nonwearing, dispersible with respect to the other resin components, and essentially nonfriable.
Claim 12
Dependent Claim
21 words
The invention as defined in claim 9 wherein there is about 20% polytetrafluoroethylene, about 20% fluorinated polyethylene-propylene, and about 60% poly(amide-imide).
Claim 13
Dependent Claim
25 words
The invention as defined in claim 9 wherein there is incorporated in the resin system a pigment to modify the triboelectric properties of the resin.
Claim 14
Dependent Claim
14 words
The invention as defined in claim 11 wherein the pigment is TiO 2 .
Claim 15
Dependent Claim
16 words
The invention as defined in claim 12 wherein there is about 9% TiO 2 by weight.
Claim 16
Dependent Claim
21 words
The invention as defined in claim 10 wherein there is about 9% TiO 2 by weight incorporated in the resin system.
Claim 17
Dependent Claim
23 words
The invention as defined in claim 9 wherein said poly(amide-imide) resin is a copolymer of at least one anhydride and an organic bis-amine.
Claim 18
Dependent Claim
22 words
The invention as defined in claim 9 wherein the anhydride includes at least one from the group trimellitic anhydride and pyromellitic anhydride.
Claim 19
Dependent Claim
12 words
The invention as defined in claim 16 wherein the bis-amine is 4,4'-bis-amino-diphenylmethane.
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) | 1987-02-27 | 1987-08-29 | 1988-02-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-02-27 | 1991-08-29 | 1992-02-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-02-27 | 1995-08-29 | 1996-02-28 | $7700.00 | Window Closed / Lapsed |