US4640879A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Copying process and electrophotographic element utilizing a photoconductive pigment dispersed in an improved polymeric binder
Assignee: Canon Production Printing Netherlands BV
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Filing: 1985-08-06
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Granted: 1987-02-03
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Expires: 2005-08-06
Abstract
Abstract An electrophotographic element and an indirect electrophotographic process for producing copies are described wherein the electrophotographic element contains a photoconductive pigment dispersed in a binder, the binder being a copolymer of an acrylic or methacrylic acid ester monomer, a vinyl aryl monomer, and 1% to 3% by weight unsaturated acid, such that 2.5 to 6.0 parts by weight of copolymerized vinyl aryl monomer are present per part by weight of copolymerized acrylic or methacrylic acid ester monomer. After repeated use of this electrophotographic element, the contours of smaller sized images do not become visible on larger sized images produced after the smaller images.
Inventors
- 👤 Petrus A. M. R. Simons
- 👤 Wilhelmus J. Bouts
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 10:04
CPC Classifications
G; G03; G03G; G03G9/00; G03G9/08; G03G9/087; G03G9/08702; G03G9/08726; G03G9/08728
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
106 words
A copying process in which a transferable image is formed by charging, exposing image-wise, developing with a developing powder and then transferred onto a copying material whereupon it is fixed, wherein the transferable image is formed on an electrophotographic element comprising a support and a photoconductive layer comprising a photoconductive pigment dispersed in a binder consisting substantially of a copolymer of an acrylic or methacrylic acid ester monomer, a vinyl aryl monomer, and 1% to 3% by weight unsaturated acid wherein 2.5 to 6.0 parts by weight of copolymerized vinyl aryl monomer are present per part by weight of copolymerized acrylic or methacrylic acid ester monomer.
Claim 2
Dependent Claim
106 words
A copying process in which a transferable image is formed by charging, exposing image-wise, developing with a developing powder and then transferred onto a copying material whereupon it is fixed, wherein the transferable image is formed on an electrophotographic element comprising a support and a photoconductive layer comprising a photoconductive pigment dispersed in a binder consisting substantially of a copolymer of an acrylic or methacrylic acid ester monomer, a vinyl aryl monomer, and 1% to 3% by weight unsaturated acid wherein 2.5 to 6.0 parts by weight of copolymerized vinyl aryl monomer are present per part by weight of copolymerized acrylic or methacrylic acid ester monomer.
Claim 3
Dependent Claim
38 words
A process according to claim 1, wherein the copolymer binder in the photoconductive layer comprises 2.5 to 4.0 parts by weight of copolymerized vinyl aryl monomer per part by weight of copolymerized acrylic or methacrylic acid ester monomer.
Claim 4
Dependent Claim
24 words
A process according to claim 1, wherein the vinyl aryl monomer is styrene and the acrylic or methacrylic acid ester monomer is ethyl acrylate.
Claim 5
Dependent Claim
24 words
A process according to claim 2, wherein the vinyl aryl monomer is styrene and the acrylic or methacrylic acid ester monomer is ethyl acrylate.
Claim 6
Dependent Claim
70 words
An electrophotographic element comprising a support and a photoconductive layer comprising a photoconductive pigment dispersed in a binder consisting substantially of a copolymer of an acrylic or methacrylic acid ester monomer, a vinyl aryl monomer, and 1% to 3% by weight of unsaturated acid, wherein 2.5 to 6.0 parts by weight of copolymerized vinyl aryl monomer are present per part by weight of copolymerized acrylic or methacrylic acid ester monomer.
Claim 7
Dependent Claim
70 words
An electrophotographic element comprising a support and a photoconductive layer comprising a photoconductive pigment dispersed in a binder consisting substantially of a copolymer of an acrylic or methacrylic acid ester monomer, a vinyl aryl monomer, and 1% to 3% by weight of unsaturated acid, wherein 2.5 to 6.0 parts by weight of copolymerized vinyl aryl monomer are present per part by weight of copolymerized acrylic or methacrylic acid ester monomer.
Claim 8
Dependent Claim
35 words
An electrophotographic element according to claim 5, wherein the copolymer comprises 2.5 to b 4.0 parts by weight of copolymerized vinyl aryl monomer per part by weight of copolymerized acrylic or methacrylic acid ester monomer.
Claim 9
Dependent Claim
25 words
An electrophotographic element according to claim 5, wherein the vinyl aryl monomer is styrene and the acrylic or methacrylic acid ester monomer is ethyl acrylate.
Claim 10
Dependent Claim
25 words
An electrophotographic element according to claim 6, wherein the vinyl aryl monomer is styrene and the acrylic or methacrylic acid ester monomer is ethyl acrylate.
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) | 1990-02-02 | 1990-08-04 | 1991-02-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-02-02 | 1994-08-04 | 1995-02-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-02-02 | 1998-08-04 | 1999-02-03 | $7700.00 | Window Closed / Lapsed |