Electrophotographic organophotoreceptors with novel charge transport compounds
View Patent ↗Charge transport compounds are described that have a multiple number of hydrazone-bridged (N,N-disubstituted)arylamine groups connected by a central bridging group. Examples of charge transport compounds of this invention are those having the following generic formula: (R-Q)n-Y where R is an (N,N-disubstituted)arylamine group; Q comprises an aromatic hydrazone linking group; Y comprises a bridging group between R-Q- groups; and n is an integer between 2 and 6. An organic photoreceptor includes (a) that compound and (b) a charge generating compound; and (c) an electrically conductive substrate.
1. A charge transport compound having the following formula:
(R-Q) n -Y
where R is an (N,N-disubstituted)arylamine group;
Q comprises an aromatic hydrazone linking group;
Y comprises a bridging group between R-Q- groups where Y comprises a bond, nitrogen atom, oxygen atom, sulfur atom, a branched or linear —(CH) p — around where p is an inteaer between 1 and 10, a cycloalkyl group, or a cyclosiloxyl group; and
n is an integer between 2 and 6.
2. The charge transport compound of claim 1 wherein Y is a methylene group, a bond, S, or O and n is 2.
3. The charge transport compound of claim 1 wherein Q has the formula:
where Z is an aryl group; and X is a linking group comprising —(CH 2 ) m —, where m is an integer between 1 and 20, inclusive, and one or more of the methylene groups is optionally replaced by an oxygen atom, a carbonyl group, a —NR 6 group, a CHR 7 group, or a CR 8 R 9 group where R 6 , R 7 , R 8 , and R 9 are, independently, H, an alkyl group, or aryl group.
4. The charge transport compound of claim 3 wherein Z comprises a phenyl group.
5. The charge transport compound of claim 3 wherein X is —(CH 2 ) m — where m is an integer between 1 and 20.
6. The charge transport compound of claim 1 wherein the (N,N-disubstituted)arylamine group comprises a triarylamine group.
7. The compound of claim 6 wherein the triarylamine group has the formula:
where R 10 , R 11 , and R 12 are, independently, H, an alkyl group, or aryl group.
8. An organic photoreceptor comprising:
(a) a charge transport compound having the formula
(R-Q) n -Y
where R is an (N,N-disubstituted)arylamine group;
Q comprises an aromatic hydrazone linking group;
Y comprises a bridging group between R-Q- groups where Y comprises a bond, nitrogen atom, oxygen atom, sulfur atom, a branched or linear —(CH 2 ) p — group where p is an integer between 1 and 10, a cycloalkyl group, or a cyclosiloxyl group; and n is an integer between 2 and 6;
(b) a charge generating compound; and
(c) an electrically conductive substrate on which the charge transport compound and the charge generating compound are located.
9. The organic photoreceptor of claim 8 wherein Y is a methylene group, a bond, O, or S and n is 2.
10. The organic photoreceptor of claim 8 wherein Q is represented by the formula:
where Z is an aryl group; and X is a linking group comprising —(CH 2 ) m —, where m is an integer between 1 and 20, inclusive, and one or more of the methylene groups is optionally replaced by an oxygen atom, a carbonyl group, a —NR 6 group, a CHR 7 group, or a CR 8 R 9 group where R 6 , R 7 , R 8 , and R 9 are, independently, H, an alkyl group, or aryl group.
11. The organic photoreceptor of claim 8 wherein Z comprises a phenyl group.
12. The organic photoreceptor of claim 8 wherein said organic photoreceptor is in the form of a flexible belt or a rigid drum.
13. The organic photoreceptor of claim 8 comprising:
(a) a charge transport layer comprising said charge transport compound and a polymeric binder; and
(b) a charge generating layer comprising said charge generating compound and a polymeric binder.
14. The organic photoreceptor of claim 8 wherein the (N,N-disubstituted)arylamine group comprises a triarylamine group.
15. The organic photoreceptor of claim 14 wherein the triarylamine group has the formula:
where R 10 , R 11 , and R 12 are, independently, H, an alkyl group, or aryl group.
16. An electrophotographic imaging apparatus comprising:
(a) a plurality of support rollers; and
(b) an organic photoreceptor in the form of a flexible belt threaded around said support rollers, said organic photoreceptor comprising:
(i) a charge transport compound having the formula
(R-Q) n -Y
where R is an (N,N-disubstituted)arylamine group;
Q comprises an aromatic hydrazone linking group;
Y comprises a bridging group between R-Q- groups where Y comprises a bond, nitrogen atom, oxygen atom, sulfur atom, a branched or linear —(CH 2 ) p — group where p is an inteaer between 1 and 10, a cycloalkyl group, or a cyclosiloxyl group; and n is an integer between 2 and 6;
(ii) a charge generating compound; and
(iii) an electrically conductive substrate.
17. The electrophotographic imaging apparatus of claim 16 wherein Y is a methylene group, a bond, O, or S and n is 2.
18. The electrophotographic imaging apparatus of claim 16 wherein Z comprises a phenyl group.
19. The electrophotographic imaging apparatus of claim 16 wherein Q is represented by the formula:
where Z is an aryl group; and X is a linking group comprising —(CH 2 ) m —, where m is an integer between 1 and 20, inclusive, and one or more of the methylene groups is optionally replaced by an oxygen atom, a carbonyl group, a —NR 6 group, a CHR 7 group, or a CR 8 R 9 group where R 6 , R 7 , R 8 , and R 9 are, independently, H, an alkyl group, or aryl group.
20. The electrophotographic imaging apparatus of claim 18 wherein the (N,N-disubstituted)arylamine group comprises a triarylamine group.
21. An electrophotographic imaging process comprising:
(a) applying an electrical charge to a surface of an organic photoreceptor comprising:
(i) a charge transport compound having the formula
(R-Q) n -Y
where R is an (N,N-disubstituted)arylamine group;
Q comprises an aromatic hydrazone linking group;
Y comprises a bridging group between R-Q- groups where Y comprises a bond, nitrogen atom, oxygen atom, sulfur atom, a branched or linear —(CH 2 ) p — group where p is an integer between 0 and 10, a cycloalkyl group, or a cyclosiloxyl group; and
n is an integer between 2 and 6;
(ii) a charge generating compound; and
(iii) an electrically conductive substrate;
(b) imagewise exposing said surface of said organic photoreceptor to radiation to dissipate charge in selected areas and thereby form a pattern of charged and uncharged areas on said surface;
(c) contacting said surface with a toner comprising colorant particles; and
(d) transferring said toned image to a substrate.
22. The electrophotographic imaging process of claim 21 wherein Y is a methylene group, a bond, O, or S and n is 2.
23. The electrophotographic imaging process of claim 21 wherein Z comprises a phenyl group.
24. The electrophotographic imaging process of claim 21 wherein Q is represented by the formula of the formula:
where Z is an aryl group; and X is a linking group comprising —(CH 2 ) m —, where m is an integer between 0 and 20, inclusive, and one or more of the methylene groups is optionally replaced by an oxygen atom, a carbonyl group, a —NR 6 group, a CHR 7 group, or a CR 8 R 9 group where R 6 , R 7 , R 8 , and R 9 are, independently, H, an alkyl group, or aryl group.
25. The electrophotographic imaging process of claim 20 wherein the (N,N-disubstituted)arylamine group is a triarylamine group.