Organic photoconductors having protective coatings with nanoparticles

Patent metadata

Field	Value
Publication number	US-9482970-B2
Application number	US-201214373581-A
Country	US
Kind code	B2
Filing date	Mar 30, 2012
Priority date	Mar 30, 2012
Publication date	Nov 1, 2016
Grant date	Nov 1, 2016

Abstract

An organic photoconductor includes: a conductive substrate; a charge generation layer formed on the conductive substrate; a charge transport layer formed on the charge generation layer; and a protective coating formed on the charge transport layer. The protective coating comprises nanoparticles incorporated in an in-situ cross-linked polymer matrix. A process for increasing mechanical strength in an organic photoconductor is also provided.

First claim

What is claimed is:

1. An organic photoconductor including:
a conductive substrate;
a charge generation layer formed on the conductive substrate;
a charge transport layer formed on the charge generation layer; and
a protective coating formed on the charge transport layer, the protective coating comprising inorganic nanoparticles incorporated in an in-situ cross-linked polymer matrix together with an alcohol-soluble hole transport material embedded in the in-situ cross-linked polymer, wherein the hole transport material comprises a cationic alternating fluorene-based copolymer with phosphonium salt functionalized side chains.

2. The organic photoconductor of claim 1 wherein the alcohol soluble hole transport material embedded in the in-situ cross-linked polymer comprises a copolymer selected from the group consisting of fluorene copolymers with phosphonium salt functionalized side chains and dialkyl substituted fluorene derivatives; fluorene copolymers with phosphonium salt functionalized side chains and substituted carbazole derivatives; fluorene copolymers with phosphonium salt functionalized side chains and substituted benzothiadiazole derivatives; fluorene copolymers with phosphonium salt functionalized side chains and substituted phenothiazine derivatives; fluorene copolymers with phosphonium salt functionalized side chains and substituted 2,7-diaminocarbazole derivatives; fluorene copolymers with phosphonium salt functionalized side chains and substituted 1,4-diphenylaminobenzene derivatives; and fluorene copolymers with phosphonium salt functionalized side chains and substituted bisphenylbenzidine derivatives.

3. The organic photoconductor of claim 1 wherein the, inorganic nanoparticles have a concentration in the protective coating within a range of about 1 to 50 wt %.

4. The organic photoconductor of claim 1 wherein the, inorganic nanoparticles have a particle size of less than about 100 nm.

5. The organic photoconductor of claim 1 , wherein the protective coating is formed from a solution including:
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 alternating fluorene-based copolymer with phosphonium salt functionalized side chains;
1 to 50 wt % of the inorganic nanoparticles; and
0.1 to 20 wt % alcohol-based solvent.

6. The organic photoconductor of claim 5 wherein the cross-linkable monomer is selected from the group consisting of N-alkyl acrylamides, N-aryl acrylamides, N-alkoxyalkyl acrylamides, N-alkyl methacrylamides, N-aryl methacrylamides, N-alkoxyalkyl acrylamides, N-vinyl amides, N-vinyl cyclic amides, heterocyclic vinyl amines, polyethylene glycolated acrylates, polyethylene glycolated methacrylates, and cationic monomers.

7. The organic photoconductor of claim 5 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 heat or UV.

8. The organic photoconductor of claim 5 wherein the initiator is selected from the group consisting of thermally-activated initiators and photo-activated initiators.

9. The organic photoconductor of claim 5 wherein the fluorene-based copolymer is selected from the group consisting of fluorene copolymers with phosphonium salt functionalized side chains and dialkyl substituted fluorene derivatives; fluorene copolymers with phosphonium salt functionalized side chains and substituted carbazole derivatives; fluorene copolymers with phosphonium salt functionalized side chains and substituted benzothiadiazole derivatives; fluorene copolymers with phosphonium salt functionalized side chains and substituted phenothiazine derivatives; fluorene copolymers with phosphonium salt functionalized side chains and substituted 2,7-diaminocarbazole derivatives; fluorene copolymers with phosphonium salt functionalized side chains and substituted 1,4-diphenylaminobenzene derivatives; and fluorene copolymers with phosphonium salt functionalized side chains and substituted bisphenylbenzidine derivatives.

10. The organic photoconductor of claim 5 wherein the solvent is selected from the group consisting of methanol, ethanol, isopropanol, propanol, butanol, 2-butanol, tert-butanol, pentanol, hexanol, perfluoro alcohols, and a mixture of an alcohol and a perfluoro alcohol.

11. A printer including an organic photoconductor drum, the organic photoconductor including:
a conductive substrate;
a charge generation layer formed on the conductive substrate;
a charge transport layer formed on the charge generation layer; and
a protective coating formed on the charge transport layer, the protective coating comprising inorganic nanoparticles incorporated in an in-situ cross-linked polymer matrix,
wherein the protective coating comprises the inorganic nanoparticles incorporated in the in-situ cross-linked polymer matrix together with an alcohol-soluble hole transport material embedded in the in-situ cross-linked polymer, wherein the hole transport material is a cationic alternating fluorene-based copolymer with phosphonium salt functionalized side chains.

12. The printer of claim 11 , wherein the
in-situ cross-linked polymer matrix, which also incorporates alcohol soluble cross-linkers and photo initiators.

Assignees

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

Inventors

• Nauka Krzysztof
• Zhou Zhang-Lin
• Zhao Lihua

Classifications

• G03G5/14726 Primary

  Halogenated polymers · CPC title

• G03G2215/00957

  Compositions · CPC title

• G03G5/14704

  comprising inorganic material · CPC title

• G03G5/147

  Cover layers · CPC title

• G03G5/14791

  Macromolecular compounds characterised by their structure, e.g. block polymers, reticulated polymers, or by their chemical properties, e.g. by molecular weight or acidity · CPC title