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US4148640A Expired / Lapsed US ⏱️ 0.0 years remaining

Developer compositions having electrically conducting filaments in carrier particle matrix

Assignee: Eastman Kodak Co
•
Filing: 1974-03-11
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Granted: 1979-04-10
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Expires: 1994-03-11
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Abstract

Abstract An electrographic developer contains a mixture of toner powder particles and carrier particles comprising tendrillar electrically conducting filaments substantially uniformly distributed in a matrix, said filaments, matrix and toner particles being triboelectrically balanced. Improved electrographic toner images are achieved by the use of the dry developers.

Inventors

  • 👤 William J. Dulmage
  • 👤 Alfred E. Fields

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-27 22:38
CPC Classifications
G; G03; G03G; G03G9/00; G03G9/08; G03G9/10; G03G9/103

Claims Analysis

Total Claims: 25
Claim 1
Independent Claim 76 words
A dry developer for developing electrostatic charge patterns comprising a mixture of toner powder particles and non-metallic carrier particles, each of said carrier particles comprising a matrix having substantially uniformly distributed therein tendrillar electrically conducting filaments extending at least through the surface of said particles, said matrix and filaments being triboelectrically different from said toner powder particles and said matrix and filaments having a triboelectric relationship of like polarity with respect to said toner powder particles.
Claim 2
Dependent Claim 76 words
A dry developer for developing electrostatic charge patterns comprising a mixture of toner powder particles and non-metallic carrier particles, each of said carrier particles comprising a matrix having substantially uniformly distributed therein tendrillar electrically conducting filaments extending at least through the surface of said particles, said matrix and filaments being triboelectrically different from said toner powder particles and said matrix and filaments having a triboelectric relationship of like polarity with respect to said toner powder particles.
Claim 3
Dependent Claim 18 words
The developer of claim 1 wherein the filaments have a volume resistivity less than about 10 10 ohm-cm.
Claim 4
Dependent Claim 31 words
The developer of claim 1 wherein the filaments are flexible materials having a diameter of from 4 to 24 microns and a length in the range of 250 to 3500 microns.
Claim 5
Dependent Claim 11 words
The developer of claim 1 wherein the filaments are stainless steel.
Claim 6
Dependent Claim 12 words
The developer of claim 1 wherein the matrix is a synthetic polymer.
Claim 7
Dependent Claim 11 words
The developer of claim 5 wherein the matrix is poly(vinylidene fluoride-co-tetrafluoroethylene).
Claim 8
Dependent Claim 17 words
The developer of claim 1 wherein the matrix particle size is from about 250 to 1000 microns.
Claim 9
Dependent Claim 23 words
The developer of claim 1 wherein the filaments comprise from 40 to 90% by weight of the total weight of matrix and filament.
Claim 10
Dependent Claim 10 words
The developer of claim 1 wherein the matrix is glass.
Claim 11
Dependent Claim 18 words
The developer of claim 1 wherein the matrix has a volume resistivity more than about 10 10 ohm-cm.
Claim 12
Dependent Claim 19 words
The developer of claim 1 wherein the filaments are non-conductive with a continuous outer coating of a conductive material.
Claim 13
Dependent Claim 140 words
A dry developer for developing electrostatic charge patterns comprising a mixture of toner powder particles and non-metallic carrier particles having a particle size of from 250 to 1000 microns and a volume resistivity more than about 10 10 ohm-cm, each of said particles containing a matrix having uniformly distributed therein tendrillar filaments having a volume resistivity less than about 10 10 ohm-cm, and a diameter of from 4 to 24 microns and a length in the range of 250 to 3500 microns, and wherein the filaments comprise from 40 to 90% by weight of the matrix and filament, said filaments extending at least to the surface of said particles, said matrix and filaments being triboelectrically different from said toner powder particles, and said matrix and filaments having a triboelectric relationship of like polarity with respect to said toner powder particles.
Claim 14
Dependent Claim 140 words
A dry developer for developing electrostatic charge patterns comprising a mixture of toner powder particles and non-metallic carrier particles having a particle size of from 250 to 1000 microns and a volume resistivity more than about 10 10 ohm-cm, each of said particles containing a matrix having uniformly distributed therein tendrillar filaments having a volume resistivity less than about 10 10 ohm-cm, and a diameter of from 4 to 24 microns and a length in the range of 250 to 3500 microns, and wherein the filaments comprise from 40 to 90% by weight of the matrix and filament, said filaments extending at least to the surface of said particles, said matrix and filaments being triboelectrically different from said toner powder particles, and said matrix and filaments having a triboelectric relationship of like polarity with respect to said toner powder particles.
Claim 15
Dependent Claim 154 words
A dry developer for developing electrostatic charge patterns comprising a mixture of toner powder particles in the size range of from about 0.5 to about 250 microns and polymeric carrier particles having a particle size of from 250 to 1000 microns and a volume resistivity more than about 10 10 ohm-cm, each of said particles containing a matrix having uniformly distributed therein tendrillar stainless steel filaments having a volume resistivity less than about 10 10 ohm-cm and a diameter of from 4 to 24 microns and a length in the range of 250 to 3500 microns and wherein the filaments comprise from 40 to 90% by weight of the matrix and filaments, said filaments extending at least to the surface of said particles, said matrix and filaments being triboelectrically different from said toner powder particles, and said matrix and filaments having a triboelectric relationship of like polarity with respect to said toner powder particles.
Claim 16
Dependent Claim 154 words
A dry developer for developing electrostatic charge patterns comprising a mixture of toner powder particles in the size range of from about 0.5 to about 250 microns and polymeric carrier particles having a particle size of from 250 to 1000 microns and a volume resistivity more than about 10 10 ohm-cm, each of said particles containing a matrix having uniformly distributed therein tendrillar stainless steel filaments having a volume resistivity less than about 10 10 ohm-cm and a diameter of from 4 to 24 microns and a length in the range of 250 to 3500 microns and wherein the filaments comprise from 40 to 90% by weight of the matrix and filaments, said filaments extending at least to the surface of said particles, said matrix and filaments being triboelectrically different from said toner powder particles, and said matrix and filaments having a triboelectric relationship of like polarity with respect to said toner powder particles.
Claim 17
Dependent Claim 87 words
An electrophotographic process which comprises forming an electrostatic image on a photoconductor and developing the image with a dry developer comprising a mixture of toner powder particles and non-metallic carrier particles, each of said carrier particles containing a matrix having uniformly distributed therein tendrillar electrically conductive filaments extending at least through the surface of said particles, said matrix and filaments being triboelectrically different from said toner powder particles, and said matrix and filaments having a triboelectric relationship of like polarity with respect to said toner powder particles.
Claim 18
Dependent Claim 87 words
An electrophotographic process which comprises forming an electrostatic image on a photoconductor and developing the image with a dry developer comprising a mixture of toner powder particles and non-metallic carrier particles, each of said carrier particles containing a matrix having uniformly distributed therein tendrillar electrically conductive filaments extending at least through the surface of said particles, said matrix and filaments being triboelectrically different from said toner powder particles, and said matrix and filaments having a triboelectric relationship of like polarity with respect to said toner powder particles.
Claim 19
Dependent Claim 19 words
The electophotographic process of claim 14 wherein the filaments have a volume resistivity less than about 10 10 ohm-cm.
Claim 20
Dependent Claim 34 words
The electrophotographic process of claim 14 wherein the filaments are a flexible material having a diameter of from 4 to 24 microns and a length in the range of from 250 to 3500 microns.
Claim 21
Dependent Claim 19 words
The electrophotographic process of claim 14 wherein the matrix particle size is from about 250 to about 1000 microns.
Claim 22
Dependent Claim 24 words
The electrophotographic process of claim 14 wherein the filaments comprise from 40 to 90% by weight of the total weight of matrix and filament.
Claim 23
Dependent Claim 19 words
The electrophotographic process of claim 14 wherein the matrix has a volume resistivity more than about 10 10 ohm-cm.
Claim 24
Dependent Claim 152 words
An electrophotographic process which comprises forming an electrostatic image on a photoconductor and developing the image with a dry developer comprising a mixture of toner powder particles and non-metallic carrier particles having a particle size of from 250 to 1000 microns and a volume resistivity more than about 10 10 ohm-cm, each of said particles containing a matrix having uniformly distributed therein tendrillar filaments having a volume resistivity less than about 10 10 ohm-cm and a diameter of from 4 to 24 microns and a length in the range of 250 to 3500 microns and wherein the filaments comprise from 40 to 90% by weight of the matrix and filament, said filaments extending at least to the surface of said particles, said matrix and filaments being triboelectrically different from said toner powder particles and said matrix and filaments having a triboelectric relationship of like polarity with respect to said toner powder particles.
Claim 25
Dependent Claim 152 words
An electrophotographic process which comprises forming an electrostatic image on a photoconductor and developing the image with a dry developer comprising a mixture of toner powder particles and non-metallic carrier particles having a particle size of from 250 to 1000 microns and a volume resistivity more than about 10 10 ohm-cm, each of said particles containing a matrix having uniformly distributed therein tendrillar filaments having a volume resistivity less than about 10 10 ohm-cm and a diameter of from 4 to 24 microns and a length in the range of 250 to 3500 microns and wherein the filaments comprise from 40 to 90% by weight of the matrix and filament, said filaments extending at least to the surface of said particles, said matrix and filaments being triboelectrically different from said toner powder particles and said matrix and filaments having a triboelectric relationship of like polarity with respect to said toner powder particles.

References Cited (Backward Citations)

US2965573A Cited
US3752666A Cited
US3639245A Cited
US3839029A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1982-04-09 1982-10-09 1983-04-10 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1986-04-09 1986-10-09 1987-04-10 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1990-04-09 1990-10-09 1991-04-10 $7700.00 Window Closed / Lapsed

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