Processes for coating photoconductors
View Patent ↗A process including: providing a cylindrical substrate rotating about the long axis; applying at least one coating layer with a direct writing applicator on the outer surface of the rotating substrate; and curing the resulting coated layer or layers. The use of a direct writing applicator provides precision in the dispensing of organic photoconductor coating layers with respect to line width and line thickness.
1. A process for coating a photoconductor, said process comprising:
providing a cylindrical substrate rotating about the long axis;
applying at least one coating layer with a direct writing applicator on the outer surface of the rotating substrate;
curing the resulting coated layer or layers; and
applying a spreading and coalescing force on said coated layer or layers to provide a coating having a uniform thickness, the spreading and coalescing force consisting of a force selected from the group consisting of capillary action, surface centrifugation, vibration, ultrasonic excitation, and combinations thereof,
wherein said cylindrical substrate is rotated at a rotational rate and said coating is dispensed from said direct writing applicator at a coating dispense rate such that the rotational rate of the cylindrical substrate and the coating dispense rate provide a single coating coverage rate of from about 0.1 square inches per second to about 5 square inches per second.
2. A process in accordance with claim 1 , wherein the rotating is accomplished by mounting the cylindrical substrate on a rotating spindle.
3. A process in accordance with claim 1 , wherein the at least one coating is a photoconductive material.
4. A process in accordance with claim 1 , wherein the at least one coating is an electrically insulating material.
5. A process in accordance with claim 4 , further comprising applying at least one coating of a photoconductive material over the resulting electrically insulating material layer.
6. A process in accordance with claim 5 , wherein from about 2 to 10 coatings of a photoconductive material are applied over the resulting electrically insulating material layer.
7. A process in accordance with claim 5 , further comprising applying at least one coating of a hole transport material over the resulting photoconductive material layer or layers.
8. A process in accordance with claim 5 , further comprising applying at least one coating of a protective overcoating material over the resulting photoconductive material layer or layers.
9. A process in accordance with claim 7 , further comprising applying at least one coating of a protective overcoating material over the resulting hole transport material layer.
10. A process in accordance with claim 1 , wherein the at least one coating is applied to the substrate in a thickness of from about 0.0001 inches to about 0.01 inches.
11. A process in accordance with claim 1 , wherein the at least one coating is applied to the substrate in a lateral width of from about 0.002 inches to about 0.2 inches.
12. A process in accordance with claim 1 , wherein the coating dispense rate from the direct write applicator is continuous and provides a continuous coating layer of uniform layer thickness.
13. A process in accordance with claim 1 , wherein the coating dispense rate from the direct write applicator is discontinuous and provides a discontinuous coating of uniform layer thickness.
14. A process in accordance with claim 1 , wherein the at least one coating is a mixture of at least two co-reactive materials.