Alcohol-soluble hole transport materials for organic photoconductor coatings

Patent metadata

Field	Value
Publication number	US-9235147-B2
Application number	US-201114364994-A
Country	US
Kind code	B2
Filing date	Dec 20, 2011
Priority date	Dec 15, 2011
Publication date	Jan 12, 2016
Grant date	Jan 12, 2016

Abstract

An alcohol-soluble organic coating including a hole transport material formed on a surface of organic photoconductor is provided. The coating comprises a cationic alternate fluorene-based copolymer with phosphonium salt terminal groups embedded in an in-situ cross-linked polymer.

First claim

What is claimed is:

1. An organic coating formed on a surface of an organic photoconductor, the coating comprising an alcohol-soluble hole transport material embedded in an in-situ cross-linked polymer, wherein the hole transport material is a cationic alternate fluorene-based copolymer with phosphonium salt terminal groups.

2. The organic coating of claim 1 comprising a copolymer selected from the group consisting of fluorene copolymers with phosphonium salt terminal groups and dialkyl substituted fluorene derivatives; fluorene copolymers with phosphonium salt terminal groups and substituted carbazole derivatives; fluorene copolymers with phosphonium salt terminal groups and substituted benzothiadiazole derivatives; fluorene copolymers with phosphonium salt terminal groups and substituted phenothiazine derivatives; fluorene copolymers with phosphonium salt terminal groups and substituted 2,7-diaminocarbazole derivatives; fluorene copolymers with phosphonium salt terminal groups and substituted 1,4-diphenylaminobenzene derivatives; and fluorene copolymers with phosphonium salt terminal groups and substituted bisphenylbenzidine derivatives.

3. The coating of claim 1 wherein the organic photoconductor comprises a substrate, a charge generation layer on the substrate, a charge transport layer on the charge generation layer, and the organic coating on the charge transport layer.

4. A process for forming the organic coating on the surface of the organic photoconductor of claim 1 , the process including:
forming a solution including a cross-linkable monomer, oligomer, or polymer, a cross-linking agent, an initiator, a cationic alternate fluorene-based copolymer with phosphonium salt terminal groups, and an alcohol-based solvent;
applying the solution to the surface of the organic photoconductor; and
cross-linking the solution in-situ on the surface, to form the fluorene-based copolymer embedded in an in-situ cross-linked polymer.

5. The process of claim 4 wherein the cross-linkable monomer, oligomer, or polymer is selected from the group consisting of N-alkyl acrylamides, N-aryl acrylamides and N-alkoxyalkyl acrylamides, the corresponding methacrylamides, N-vinyl amides, N-vinyl cyclic amides, heterocyclic vinyl amines, polyethylene glycolated acrylates, polyethylene glycolated methacrylates, cationic monomers, and combinations thereof.

6. The process of claim 4 wherein the cross-linking agent is selected from the group consisting of 2-branch, 3-branch, and 4-branch cross-linkers that can be initiated with energy provided by UV or heat.

7. The process of claim 4 wherein the initiator is selected from the group consisting of photo-activated initiators and thermally-activated initiators.

8. The process of claim 4 wherein the fluorene-based copolymer is selected from the group consisting of fluorene copolymers with phosphonium salt terminal groups and dialkyl substituted fluorene derivatives; fluorene copolymers with phosphonium salt terminal groups and substituted carbazole derivatives; fluorene copolymers with phosphonium salt terminal groups and substituted benzothiadiazole derivatives; fluorene copolymers with phosphonium salt terminal groups and substituted phenothiazine derivatives; fluorene copolymers with phosphonium salt terminal groups and substituted 2,7-diaminocarbazole derivatives; fluorene copolymers with phosphonium salt terminal groups and substituted 1,4-diphenylaminobenzene derivatives; and fluorene copolymers with phosphonium salt terminal groups and substituted bisphenylbenzidine derivatives.

9. The process of claim 4 in which the alcohol-based solvent is selected from the group consisting of methanol, ethanol, propanol, iso-propanol, butanol, 2-butanol, tert-butanol, pentanol, hexanol, their perfluorinated analogs, and mixtures thereof.

10. The process of claim 4 wherein the solution includes:
0.1 to 40 wt % cross-linkable monomer, oligomer, or polymer;
0.1 to 50 wt % cross-linking agent;
0.1 to 20 wt % initiator;
0.05 to 40 wt % cationic alternate fluorene-based copolymer with phosphonium salt terminal groups; and
0.1 to 20 wt % alcohol-based solvent.

11. Alcohol-soluble cationic alternate fluorene-based copolymers with phosphonium salt terminal groups.

12. The fluorene-based copolymers of claim 11 having a structure selected from the group consisting of:
fluorene copolymers with phosphonium salt terminal groups and dialkyl substituted fluorene derivatives:

fluorene copolymers with phosphonium salt terminal groups and substituted carbazole derivatives:

fluorene copolymers with phosphonium salt terminal groups and substituted benzothiadiazole derivatives:

fluorene copolymers with phosphonium salt terminal groups and substituted phenothiazine derivatives:

fluorene copolymers with phosphonium salt terminal groups and substituted 2,7-diaminocarbazole derivatives:

fluorene copolymers with phosphonium salt terminal groups and substituted 1,4-diphenylaminobenzene derivatives:

and
fluorene copolymers with phosphonium salt terminal groups and substituted bisphenylbenzidine derivatives:

wherein:
R 1 , R 2 , R 3 , R 4 , and R 5 are each independently selected from the group consisting of C1-C30 alkyl, C1-C30 alkenyl, C1-C30 alkynyl, C1-C30 aryl, C1-C30 alkoxy, C1-C30 phenoxy, C1-C30 thioalkyl, C1-C30 thioaryl, C(O)OR 6 , N(R 7 )(R 8 ), C(O)N(R 9 )(R 10 ), F, Cl, Br, NO 2 , CN, acyl, carboxylate and hydroxy, wherein R 6 , R 7 , R 8 , R 9 and R 10 are each independently selected from the group consisting of hydrogen, C1-C30 alkyl and C1-C30 aryl, and so forth. R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 and R 9 may be the same or different;
n is an integer between 1 and 30;
m is an integer between 1 and 5,000; and
X represents an anion selected from the group consisting of Br − , Cl − , I − , tetrafluoroborate, and tetraphenyl borate.

13. The fluorene-based copolymers of claim 11 wherein the copolymers are soluble in an alcohol selected from the group consisting of methanol, ethanol, propanol, iso-propanol, butanol, 2-butanol, tert-butanol, pentanol, hexanol, their perfluorinated analogs, and mixtures thereof.

14. An organic photoconductor comprising a substrate, a charge generation layer formed on the substrate, a charge transport layer formed on the charge generation layer, and a protective coating on the charge transport layer, the protective coating comprising a cationic alternate fluorene-based copolymer with phosphonium salt terminal groups embedded in an in-situ cross-linked polymer.

15. The organic photoconductor of claim 14 wherein the fluorene-based copolymer is selected from the group consisting of fluorene copolymers with phosphonium salt terminal groups and dialkyl substituted fluorene derivatives; fluorene copolymers with phosphonium salt terminal groups and substituted carbazole derivatives; fluorene copo

Assignees

• Zhou Zhang-Lin
• Nauka Krzysztof
• Zhao Lihua
• Hewlett Packard Development Co

Inventors

• Zhou Zhang-Lin
• Nauka Krzysztof
• Zhao Lihua

Classifications

• G03G5/05

  Organic bonding materials; Methods for coating a substrate with a photoconductive layer; Inert supplements for use in photoconductive layers · CPC title

• G03G5/047

  characterised by the charge-generation layers or charge transport layers {(G03G5/0433 and G03G5/0436 take precedence)} · CPC title

• G03G5/0546

  Polymers comprising at least one carboxyl radical, e.g. polyacrylic acid, polycrotonic acid, polymaleic acid; Derivatives thereof, e.g. their esters, salts, anhydrides, nitriles, amides · CPC title

• G03G5/0575

  Other polycondensates comprising nitrogen atoms with or without oxygen atoms in the main chain · CPC title

• G03G5/0507

  Inorganic compounds · CPC title