Patent US4286040A successfully refreshed from Google Patents.
US4286040A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for preparing an electrophotographic element
Assignee: Canon Production Printing Netherlands BV
•
Filing: 1979-08-09
•
Granted: 1981-08-25
•
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 07:57
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.
References Cited (Backward Citations)
US2002174A
Cited
GB1145374A
Cited
GB1146142A
Cited
GB1172355A
Cited
GB1296390A
Cited
US3676210A
Cited
US3898084A
Cited
US3929488A
Cited
US4065254A
Cited
US3977870A
Cited
FR2210693A1
Cited
US4018602A
Cited
NL7507972A
Cited
US4052210A
Cited
US4123270A
Cited
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 |