Electrostatographic apparatus having improved transport member
View Patent ↗The present invention is an electrostatographic reproduction apparatus which includes a primary imaging member for producing an electrostatic latent image, a development station for applying toner particles to said latent image which forms a developed toner image, and a transfer station for transferring said developed toner image from the primary imaging member to a receiver. A fuser assembly is included for fixing the developed toner image to the receiver, to form a fused toner image on the receiver. An endless transport member is provided for transporting the receiver to or from the fuser assembly, the transport member having a substrate bearing an oil-absorbing porous layer that would tribocharge positively upon contact with negatively charged toner particles, and a porous overcoat outermost layer that does not tribocharge positively upon contact with negatively charged toner particles.
1. An electrostatographic reproduction apparatus comprising:
a primary imaging member for producing an electrostatic latent image;
a development station for applying toner particles to said latent image, thereby forming a developed toner image;
a transfer station for transferring said developed toner image from the primary imaging member to a receiver;
a fuser assembly for fixing said developed toner image to said receiver, thereby forming a fused toner image on said receiver;
an endless transport member for transporting said receiver to or from said fuser assembly, said transport member comprising a substrate bearing an oil-absorbing porous layer that would tribocharge positively upon contact with negatively charged toner particles, and a porous overcoat outermost layer that does not tribocharge positively upon contact with negatively charged toner particles;
wherein the porous overcoat outermost layer comprises silica particles and a binder of polyvinyl alcohol or polyvinyl butyral in a weight ratio of from about 5:1 to about 20:1; and has a dried thickness of 0.25 to 10 micrometers that allows for silicone oil absorption with a value of 200 to 600 mg/m 2 /μm,
2. The electrostatographic reproduction apparatus of claim 1 , wherein the oil-absorbing porous layer comprises gamma-alumina particles having an average dispersed particle size of less than 0.5 microns dispersed in a polymeric binder.
3. The electrostatographic reproduction apparatus of claim 2 , wherein said gamma-alumina particles have an average dispersed particle size of less than 0.3 microns.
4. The electrostatographic reproduction apparatus of claim 1 , wherein the oil-absorbing porous layer is and porous overcoat outermost layer are transparent.
5. The electrostatographic reproduction apparatus of claim 1 , wherein the oil-absorbing porous layer comprises ceramic particles dispersed in a polymer binder.
6. The electrostatographic reproduction apparatus of claim 1 , wherein said oil-absorbing porous layer comprises gamma-alumina particles and poly(vinyl butyral) in a weight ratio of about 3:1 to about 20:1.
7. The electrostatographic reproduction apparatus of claim 1 , wherein said substrate bearing an oil-absorbing porous layer is selected from the group consisting of a continuous web loop, a drum, and a roller.
8. The electrostatographic reproduction apparatus of claim 1 , wherein the transport member has a resistivity equal to or greater than 5×10 12 ohm/sq at 70° F./60% RH.
9. The electrostatographic reproduction apparatus of claim 1 , wherein said development station comprises a plurality of separate developing devices to enable full color image reproduction.
10. The electrostatographic reproduction apparatus of claim 1 , wherein said reproduction apparatus is adapted for duplex printing.
11. The electrostatographic reproduction apparatus of claim 1 , wherein said transport member comprises a polyethylene terephthalate substrate.
12. The electrostatographic reproduction apparatus of claim 1 wherein the porous overcoat outermost layer further comprises polydimethylsiloxane.
13. The electrostatographic reproduction apparatus of claim 1 wherein the overcoat further comprises a fluorosurfactant.
14. The electrostatographic reproduction apparatus of claim 13 wherein the fluorosurfactant is ZONYL FSN.
15. The electrostatographic reproduction apparatus of claim 13 , wherein the transport member has a surface resistivity equal to or greater than 5×10 12 ohm/sq at 70° F./60% RH.
16. The electrostatographic reproduction apparatus of claim 1 , further comprising an intermediate image transfer member operationally associated with the primary image-forming member for transferring the developed toner image from the primary imaging member to the receiver.