Photoconductor having protective overcoat layer with a charge transport molecule with four radical polymerizable hydrophilic functional groups containing an oxygen atom and method of making the same
A method to make an improved organic photoconductor drum of an electrophotographic image forming device is provided. The improved organic photoconductor drum is prepared using a curable composition including a charge transport molecule containing four radical polymerizable functional groups containing an oxygen atom of the general structure shown below: wherein R 1 and R 2 contain a spacer group and a radical polymerizable hydrophilic functional group containing an oxygen atom, R 3 and R 4 are a non-radical polymerizable functional group, and R 5 and R 6 contain a spacer group and a radical polymerizable hydrophilic functional group containing an oxygen atom. The curable composition may also contain at least one optional curing agent.
1. A method of preparing a photoconductor comprising:
providing an electrically conductive substrate;
preparing a charge generation layer dispersion;
coating the charge generation layer dispersion onto the electrically conductive substrate to form a charge generation layer;
preparing a charge transport layer dispersion;
coating the charge transport layer dispersion over the charge generation layer to form a charge transport layer;
preparing an overcoat layer including:
an organic solvent;
about 20 to about 80 percent by weight of a charge transport molecule containing four radical polymerizable hydrophilic functional groups containing an oxygen atom as shown below:
wherein R 1 and R 2 contain a spacer group and a radical polymerizable hydrophilic functional group containing an oxygen atom, R 3 and R 4 are a non-radical polymerizable functional group, and R 5 and R 6 contain a spacer group and a radical polymerizable hydrophilic functional group containing an oxygen atom; and
about 20 to about 80 percent by weight of a curing agent having a urethane containing six radical polymerizable functional groups;
coating the overcoat layer formulation over the charge transport layer; and
curing the overcoat layer formulation to form a photoconductor having an overcoat layer over the charge transport layer and the charge generation layers, wherein the radical polymerizable hydrophilic functional group containing an oxygen atom of R 1 and R 2 is selected from the group consisting of acrylate group, methacrylate group, glycidyl ether group and epoxy group.
2. The method of claim 1 , wherein the spacer group of R 1 and R 2 is an unbranched alkyl group containing between 1 and about 6 carbon atoms.
3. The method of claim 2 , wherein the unbranched alkyl group containing between 1 and 6 carbon atoms is an ethyl group.
4. The method of claim 1 , wherein the radical polymerizable functional group containing an oxygen atom of R 1 and R 2 is an acrylate group.
5. The method of claim 1 , wherein R 3 and R 4 are hydrogen atoms.
6. The method of claim 1 , wherein the spacer group of R 5 and R 6 is an unbranched alkyl group containing between 1 and about 6 carbon atoms.
7. The method of claim 6 , wherein the unbranched alkyl group containing between 1 and 6 carbon atoms is an ethyl group.
8. The method of claim 1 , wherein the radical polymerizable functional group of the urethane containing six radical polymerizable functional groups is an acrylate group.
9. The method of claim 1 , wherein the overcoat layer is cured by an electron beam.
10. The method of claim 9 , wherein the cured overcoat layer has a thickness of about 0.1 μm to about 10 μm.
11. A method of preparing a photoconductor comprising:
providing an electrically conductive substrate;
preparing a charge generation layer dispersion:
coating the charge generation layer dispersion onto the electrically conductive substrate to form a charge generation layer;
preparing a charge transport layer dispersion:
coating the charge transport layer dispersion over the charge generation layer to form a charge transport layer;
preparing an overcoat layer including:
an organic solvent;
a curable composition including a charge transport molecule containing four radical polymerizable hydrophilic functional groups having an oxygen atom as shown below:
wherein R 1 and R 2 contain a spacer group and a radical polymerizable hydrophilic functional group having an oxygen atom, R 3 and R 4 are a non-radical polymerizable functional group, and R 5 and R 6 contain a spacer group and a radical polymerizable hydrophilic functional group having an oxygen atom wherein the spacer group of R 1 , R 2 , R 5 and R 6 is an ethyl group and the radical polymerizable hydrophilic functional group having an oxygen atom of R 1 , R 2 , R 5 and R 6 is an acrylate group;
coating the overcoat layer formulation over the charge transport layer; and
curing the overcoat layer formulation to form a photoconductor having an overcoat layer over the charge transport layer and the charge generation layers.
12. The method of claim 11 , wherein the overcoat layer is cured by electron beam.
13. The method of claim 11 , wherein the cured overcoat layer has a thickness of about 0.1 μm to about 10 μm.
14. A method of preparing a photoconductor comprising:
providing an electrically conductive substrate;
preparing a charge generation layer dispersion;
coating the charge generation layer dispersion onto the electrically conductive substrate to form a charge generation layer;
preparing a charge transport layer dispersion;
coating the charge transport layer dispersion over the charge generation layer to form a charge transport layer;
preparing an overcoat layer including:
an organic solvent;
about 20 to about 80 percent by weight of a charge transport molecule containing four radical polymerizable hydrophilic functional groups containing an oxygen atom as shown below:
wherein R 1 and R 2 contain a spacer group and a radical polymerizable hydrophilic functional group containing an oxygen atom, R 3 and R 4 are a non-radical polymerizable functional group, and R 5 and R 6 contain a spacer group and a radical polymerizable hydrophilic functional group containing an oxygen atom; and
about 20 to about 80 percent by weight of a curing agent having a urethane containing six radical polymerizable functional groups;
coating the overcoat layer formulation over the charge transport layer; and
curing the overcoat layer formulation to form a photoconductor having an overcoat layer over the charge transport layer and the charge generation layers, wherein the radical polymerizable functional group containing an oxygen atom of R 5 and R 6 is selected from the group consisting of acrylate group, methacrylate group, glycidyl ether group and epoxy group.
15. The method of claim 14 , wherein the radical polymerizable functional group containing an oxygen atom of R 5 and R 6 is an acrylate group.