US4286040A
Expired / Lapsed
US
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Process for preparing an electrophotographic element
Assignee: Canon Production Printing Netherlands BV
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Filing: 1979-08-09
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Granted: 1981-08-25
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Expires: 1999-08-09
Abstract
Abstract An electrophotographic element that comprises an electrically conductive support and a photoconductive layer containing a photosensitive azo-compound dispersed in a film-forming polymeric binder is prepared by synthesizing the photosensitive azo-compound in situ, by reaction between a diazonium compound and an azo-coupling component, in the film-forming polymeric layer on the support. The azo-compounds thus synthetized are distributed in the binder layer in an almost perfectly homogeneous form. Under an electron microscope screen scan they are not distinguishable as separate particles, even at a ten thousand fold magnification. By forming a very thin photoconductive layer in this way and coating it with a charge transporting top layer, especially useful electrophotographic elements are obtained. The invention relates also to electrophotographic elements prepared according to the process.
Inventors
- 👤 Gerard J. E. H. van Lomm
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 00:07
CPC Classifications
G; G03; G03G; G03G5/00; G03G5/02; G03G5/04; G03G5/06; G03G5/0664; G03G5/0675
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
56 words
A process for preparing an electrophotographic element that comprises an electrically conductive support and a photoconductive layer containing a photosensitive azo-compound dispersed in a film-forming polymeric binder, which comprises synthesizing the photosensitive azo-compound in situ by reaction between a diazonium compound and an azo-coupling component in a layer of the film-forming polymeric binder on the support.
Claim 2
Dependent Claim
56 words
A process for preparing an electrophotographic element that comprises an electrically conductive support and a photoconductive layer containing a photosensitive azo-compound dispersed in a film-forming polymeric binder, which comprises synthesizing the photosensitive azo-compound in situ by reaction between a diazonium compound and an azo-coupling component in a layer of the film-forming polymeric binder on the support.
Claim 3
Dependent Claim
54 words
Process according to claim 1, said synthesizing being effected by forming into a layer on a substrate for the photoconductive layer a solution containing the binder, the diazonium compound and the azo-coupling component at a pH that inhibits said reaction and thereafter treating the formed layer with an alkaline substance that induces said reaction.
Claim 4
Dependent Claim
55 words
Process according to claim 1, said synthesizing being effected by coating onto a surface of said support a solution containing the binder and one of either the diazonium compound reactant or the azo-coupling reactant and after at least partially drying the resultant binder layer coating onto it a solution of the other of said reactants.
Claim 5
Dependent Claim
10 words
Process according to claim 2, said alkaline substance being ammonia.
Claim 6
Dependent Claim
11 words
Process according to claim 2, said alkaline substance being 2,6-dimethyl morpholine.
Claim 7
Dependent Claim
41 words
Process according to claim 2, 4 or 5, said solution comprising as the solvent for the binder, the diazonium compound and the azo-coupling component a mixture of a relatively volatile solvent and a substantially smaller amount of a less volatile solvent.
Claim 8
Dependent Claim
30 words
Process according to claim 2, 4 or 5, said solution comprising as the solvent for the binder, the diazonium compound and the azo-coupling component a mixture of acetone and dimethylformamide.
Claim 9
Dependent Claim
20 words
Process according to claim 1, 2 or 3, said diazonium compound being a diazonium compound derived from an organic acid.
Claim 10
Dependent Claim
24 words
Process according to claim 1, 2 or 3, said diazonium compound being a diazonium compound of 4-methylbenzene-sulphonic acid, 2-naphthalene-sulphonic acid or 2-benzoyl-4-hydroxy-6 methoxy-benzenesulphonic acid.
Claim 11
Dependent Claim
36 words
Process according to claim 1, 2 or 3, said synthesizing comprising coupling a diazonium compound having formula 1 of the Formula Table with an azo-coupling component having formula 3 or formula 4 of the Formula Table.
Claim 12
Dependent Claim
23 words
Process according to claim 10, the azo-compound synthesized in situ comprising a compound having formula 7 or formula 14 of the Formula Table.
Claim 13
Dependent Claim
36 words
Process according to claim 1, 2, or 3, said synthesizing comprising coupling a diazonium compound having formula 2 of the Formula Table with an azo-coupling component having formula 3 or formula 4 of the Formula Table.
Claim 14
Dependent Claim
20 words
Process according to claim 12, the azo-compound synthesized in situ comprising a compound having formula 10 of the Formula Table.
Claim 15
Dependent Claim
16 words
Process according to claim 1, 2 or 3, said binder being a cellulose acetate butyrate polymer.
Claim 16
Dependent Claim
41 words
Process according to claim 1, 2 or 3, said synthesizing comprising coupling in said binder layer a single diazonium compound with a plurality of different color-determining azo-coupling components, or a single azo-coupling component with a plurality of different color-determining diazonium compounds.
Claim 17
Dependent Claim
28 words
Process according to claim 1, 2 or 3, and after synthesizing the azo-compound in the binder layer forming on the resultant photoconductive layer a charge transporting top layer.
Claim 18
Dependent Claim
18 words
Process according to claim 16, said top layer being a layer of a substituted or non-substituted polyvinyl carbazole.
Claim 19
Dependent Claim
18 words
Process according to claim 16, said top layer being a layer of a substituted or non-substituted polyvinyl pyrene.
Claim 20
Dependent Claim
12 words
Process according to claim 3, each said coating being effected by dip-coating.
Claim 21
Dependent Claim
40 words
Process according to claim 1, 2, or 3, and by said synthesizing in situ forming said azo-compound so homogeneously distributed in said binder that separate particles of the azo-compound are not distinguishable under an electron microscope scan at 10,000-fold magnification.
Claim 22
Dependent Claim
18 words
Process according to claim 2, said layer being formed by dip-coating or rod-coating said solution onto said substrate.
Claim 23
Dependent Claim
22 words
Process according to claim 1, 2, or 3, said layer being formed to a thickness of about 1 to about 4 microns.
Claim 24
Dependent Claim
40 words
Process according to claim 16, said photoconductive layer being formed to a thickness of about 1 to about 4 microns and said charge transporting layer giving the combined photoconductive and top layers a thickness of at least about 4 microns.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-08-24 | 1985-02-23 | 1985-08-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-08-24 | 1989-02-23 | 1989-08-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-08-24 | 1993-02-23 | 1993-08-25 | $7700.00 | Window Closed / Lapsed |