US4097620A
Expired / Lapsed
US
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Magnetic toner particle coating process
Assignee: Xerox Corp
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Filing: 1977-05-02
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Granted: 1978-06-27
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Expires: 1997-05-02
Abstract
Abstract A method of coating magnetic toner particles such as magnetite with a fatty acid or a derivative of a fatty acid is disclosed. The magnetite particles coated by this process are found to be particularly suitable for use in formation of field dependent toners that are not humidity sensitive.
Inventors
- 👤 Chin H. Lu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 16:47
CPC Classifications
G; G03; G03G; G03G9/00; G03G9/08; G03G9/083; G03G9/0839; G03G9/0825; G03G9/097; G03G9/09733
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
83 words
A process of coating magnetic toner particles comprising neutralizing a fatty acid material selected from the group comprising fatty acids, fatty acid derivatives and mixtures thereof with ammonium hydroxide to form a water soluble ammonium compound in aqueous solution, adding particles to the solution, heating the solution at below the boiling pont, filtering the solution, washing and drying to recover the coated particles wherein said fatty acid material is present in an amount between about 0.1 and 10 weight percent of the particle.
Claim 2
Dependent Claim
83 words
A process of coating magnetic toner particles comprising neutralizing a fatty acid material selected from the group comprising fatty acids, fatty acid derivatives and mixtures thereof with ammonium hydroxide to form a water soluble ammonium compound in aqueous solution, adding particles to the solution, heating the solution at below the boiling pont, filtering the solution, washing and drying to recover the coated particles wherein said fatty acid material is present in an amount between about 0.1 and 10 weight percent of the particle.
Claim 3
Dependent Claim
14 words
The process of claim 1 wherein said particles comprise sub micron magnetic toner particles.
Claim 4
Dependent Claim
10 words
The process of claim 2 wherein said particles comprise magnetite.
Claim 5
Dependent Claim
37 words
The process of claim 1 wherein said fatty acid is selected from the group consisting of stearic acid, palmitic acid, myristic acid, lauric acid, pentadecanic acid, margaric acid, oleic acid, linoleic acid and mixtures and derivatives thereof.
Claim 6
Dependent Claim
17 words
The method of claim 1 wherein said fatty acid material comprises between 6 and 22 carbon atoms.
Claim 7
Dependent Claim
26 words
The method of claim 1 wherein said fatty acid material is present in an amount between about 2 and about 3 weight percent of the particle.
Claim 8
Independent Claim
106 words
A method of toner formation comprising neutralizing a fatty acid material selected from the group comprising fatty acids, fatty acid derivatives and mixtures thereof with ammonium hydroxide to form a water soluble ammonium compound in aqueous solution, adding magnetic toner particles to the solution, heating the solution at below the boiling point, filtering the solution, washing, drying to recover the coated particles, mixing said coated particles into a solution of solvent and resin to form a slurry and spray drying said slurry to form a toner wherein said fatty acid material is present in an amount between about 0.1 and 10 weight percent of the particle.
Claim 9
Independent Claim
106 words
A method of toner formation comprising neutralizing a fatty acid material selected from the group comprising fatty acids, fatty acid derivatives and mixtures thereof with ammonium hydroxide to form a water soluble ammonium compound in aqueous solution, adding magnetic toner particles to the solution, heating the solution at below the boiling point, filtering the solution, washing, drying to recover the coated particles, mixing said coated particles into a solution of solvent and resin to form a slurry and spray drying said slurry to form a toner wherein said fatty acid material is present in an amount between about 0.1 and 10 weight percent of the particle.
Claim 10
Dependent Claim
14 words
The process of claim 7 wherein said particles comprise sub micron magnetic toner particles.
Claim 11
Dependent Claim
10 words
The process of claim 8 wherein said particles comprise magnetite.
Claim 12
Dependent Claim
37 words
The process of claim 7 wherein said fatty acid is selected from the group consisting of stearic acid, palmitic acid, myristic acid, lauric acid, pentadecanic acid, margaric acid, oleic acid, linoleic acid, and mixtures and derivatives thereof.
Claim 13
Dependent Claim
17 words
The method of claim 7 wherein said fatty acid material comprises between 6 and 22 carbon atoms.
Claim 14
Dependent Claim
26 words
The method of claim 7 wherein said fatty acid material is present in an amount between about 2 and about 3 weight percent of the particle.
Claim 15
Independent Claim
174 words
A method of toner formation comprising neutalizing a fatty acid material selected from the group comprising fatty acids, fatty acid derivatives and mixtures thereof with ammonium hydroxide to form a water soluble ammonium compound in aqueous solution, adding magnetic particles to the solution, heating the solution at below the boiling point, filtering the solution, drying to recover the coated particles, mixing said coated magnetic particles into a solution of solvent and resin and a solvent to form a slurry and spray drying said slurry to form a toner comprising resin and coated magnetite wherein the coating comprises a fatty acid or fatty acid derivative and the toner is characterized by a field dependence such that at low fields of less than 10 volt/cm the resistivity is greater than 10 12 ohm-cm and at some higher field they exhibit a sharp drop to a resistivity of less than 10 8 ohm-cm along a line of a slope greater than 5 when log of powder resistivity is plotted versus the log of the field in volt/cm.
Claim 16
Independent Claim
174 words
A method of toner formation comprising neutalizing a fatty acid material selected from the group comprising fatty acids, fatty acid derivatives and mixtures thereof with ammonium hydroxide to form a water soluble ammonium compound in aqueous solution, adding magnetic particles to the solution, heating the solution at below the boiling point, filtering the solution, drying to recover the coated particles, mixing said coated magnetic particles into a solution of solvent and resin and a solvent to form a slurry and spray drying said slurry to form a toner comprising resin and coated magnetite wherein the coating comprises a fatty acid or fatty acid derivative and the toner is characterized by a field dependence such that at low fields of less than 10 volt/cm the resistivity is greater than 10 12 ohm-cm and at some higher field they exhibit a sharp drop to a resistivity of less than 10 8 ohm-cm along a line of a slope greater than 5 when log of powder resistivity is plotted versus the log of the field in volt/cm.
Claim 17
Dependent Claim
21 words
The method of claim 13 wherein the resistivity is greater than 10 12 ohm-cm at fields of greater than 100 volt/cm.
Claim 18
Dependent Claim
12 words
The method of claim 13 wherein said slope is greater than 10.
Claim 19
Dependent Claim
15 words
The method of claim 13 wherein said slope is between about 10 and about 20.
Claim 20
Dependent Claim
17 words
The method of claim 13 wherein the resistivity at low field is greater than 10 14 ohm-cm.
Claim 21
Dependent Claim
37 words
The method of claim 13 wherein said fatty acid is selected from the group consisting of stearic acid, palmitic acid, lauric acid, myristic acid, pentadecanic acid, margaric acid, oleic acid, linoleic acid, and mixtures and derivatives thereof.
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) | 1981-06-26 | 1981-12-26 | 1982-06-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-06-26 | 1985-12-26 | 1986-06-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-06-26 | 1989-12-26 | 1990-06-27 | $7700.00 | Window Closed / Lapsed |