Method to make a photoconductor having an overcoat with tetrafunctional radical polymerizable charge transport molecule
View Patent ↗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 of the general structure exemplified below: where R 1 and R 2 contain a spacer group and a radical polymerizable functional group, R 3 and R 4 are selected from the group consisting of a radical polymerizable functional group, a non-radical polymerizable functional group, and one each of a radical polymerizable functional group and a non-radial polymerizable functional group, and R 5 and R 6 contain a spacer group and a radical polymerizable functional group.
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 functional groups as shown below:
where R 1 and R 2 contain a spacer group and a radical polymerizable functional group, 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 functional group, wherein the spacer group of R 1 , R 2 , R 5 and R 6 is an ethyl group and the radical polymerizable functional group of R 1 , R 2 , R 5 and R 6 is an acrylate group; 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.
2. The method of claim 1 wherein the urethane having six radical polymerizable functional groups is a hexa-functional aliphatic urethane acrylate having the following structure:
3. The method of claim 1 wherein the overcoat layer is cured by an electron beam.
4. The method of claim 3 wherein the cured overcoat layer has a thickness of about 0.1 μm to about 10 μm.
5. 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 functional groups as shown below:
where R 1 and R 2 contain a spacer group and a radical polymerizable functional group, 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 functional group wherein the spacer group of R 1 , R 2 , R 5 and R 6 is an ethyl group and the radical polymerizable functional group 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.
6. The method of claim 5 wherein the overcoat layer is cured by electron beam.
7. The method of claim 6 wherein the cured overcoat layer has a thickness of about 0.1 μm to about 10 μm.