Patent US4425383A successfully refreshed from Google Patents.
US4425383A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for oxidation of carrier particles
Assignee: Xerox Corp
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Filing: 1982-07-06
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Granted: 1984-01-10
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Expires: 2002-07-06
Abstract
Abstract This invention is directed to an improved process for treating steel carrier core surfaces which comprises providing a steel carrier core composition, oxidizing in the air stream the surface of the carrier core at a temperature of from about 500 degrees Fahrenheit to about 1,000 degrees Fahrenheit, adding water to the air stream prior to accomplishing the oxidation reaction, at a partial pressure of water in excess of 20 millimeters of mercury, thereby resulting in carrier cores having a resistance of from about 10 5 ohm-cm to about 10 12 ohm-cm.
Inventors
- 👤 John A. Creatura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 11:17
CPC Classifications
C; C23; C23C; C23C8/00; C23C8/06; C23C8/08; C23C8/10; C23C8/16; C23C8/18; G; G03; G03G; G03G9/00; G03G9/08; G03G9/10; G03G9/107; G03G9/1075
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
88 words
An improved process for treating steel carrier core surfaces which consisting essentially of providing steel carrier core particles, oxidizing in an air stream the surface of the carrier core particles at a temperature of from about 500 degrees Fahrenheit to about 1,000 degrees Fahrenheit, adding water to the air stream prior to accomplishing the oxidation reaction, at a partial pressure of water in excess of 20 millimeters of mercury, thereby resulting in carrier cores having a resistance of from about 10 5 ohm-cm to about 10 12 ohm-cm.
Claim 2
Dependent Claim
88 words
An improved process for treating steel carrier core surfaces which consisting essentially of providing steel carrier core particles, oxidizing in an air stream the surface of the carrier core particles at a temperature of from about 500 degrees Fahrenheit to about 1,000 degrees Fahrenheit, adding water to the air stream prior to accomplishing the oxidation reaction, at a partial pressure of water in excess of 20 millimeters of mercury, thereby resulting in carrier cores having a resistance of from about 10 5 ohm-cm to about 10 12 ohm-cm.
Claim 3
Dependent Claim
27 words
An improved process in accordance with claim 1 wherein the partial pressure of water ranges from about 30 millimeters of mercury to about 300 millimeters of mercury.
Claim 4
Dependent Claim
30 words
A process in accordance with claim 1 wherein the oxidizing reaction is accomplished for a period of about 1 hour and the temperature of oxidation is about 650 degrees Fahrenheit.
Claim 5
Dependent Claim
27 words
The process in accordance with claim 1 wherein the resulting carrier core particles contain from about 0.1 weight percent to about 10 weight percent of iron oxides.
Claim 6
Dependent Claim
24 words
A process in accordance with claim 4 wherein the iron oxides are comprised of Fe 2 O 3 . Fe 3 O 4 .
Claim 7
Dependent Claim
17 words
A process in accordance with claim 1 wherein the resulting carrier core is coated with a fluoropolymer.
Claim 8
Dependent Claim
13 words
A process in accordance with claim 6 wherein the fluoropolymer is polyvinylidene fluoride.
Claim 9
Dependent Claim
32 words
A process in accordance with claim 1 wherein the resulting carrier particles are capable of triboelectrically charging to from about minus 5 microcoloumbs per gram to about minus 40 microcoloumbs per gram.
References Cited (Backward Citations)
US2728696A
Cited
US3377213A
Cited
US3617394A
Cited
US3906125A
Cited
US3767477A
Cited
US3923503A
Cited
US4035200A
Cited
US4223085A
Cited
US4294628A
Cited
US4158561A
Cited
US4297150A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-01-09 | 1987-07-11 | 1988-01-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-01-09 | 1991-07-11 | 1992-01-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-01-09 | 1995-07-11 | 1996-01-10 | $7700.00 | Window Closed / Lapsed |