Radiation imagery chemistry: process – composition – or product th – Electric or magnetic imagery – e.g. – xerography,... – Radiation-sensitive composition or product
Reexamination Certificate
1999-11-15
2001-03-13
Goodrow, John (Department: 1753)
Radiation imagery chemistry: process, composition, or product th
Electric or magnetic imagery, e.g., xerography,...
Radiation-sensitive composition or product
C430S065000
Reexamination Certificate
active
06200716
ABSTRACT:
FIELD OF THE INVENTION
This invention is directed to a photoreceptor useful for an electrostatographic printing machine, and more particularly to a blocking layer of a photoreceptor.
BACKGROUND OF THE INVENTION
The demand for improved print quality in xerographic reproduction is increasing, especially with the advent of color. Some of the print quality issues such as the defect level of the charge deficient spots (“CDS”) and the print defects caused by bias charge roll (“BCR”) leakage, are strongly dependent on the quality of the charge blocking layer. Conventional materials used for the blocking layer have been problematic. In certain situations, a thicker blocking layer is desirable, but the thickness of the material used for the blocking layer is limited by the inefficient transport of the photoinjected electrons from the generator layer to the substrate. Another problem is posed by a blocking layer that is too thin: incomplete coverage of the substrate due to wetting problems on localized unclean substrate surface areas. These pin holes can then produce CDS and BCR leakage breakdown. A thicker blocking layer can be produced by dispersing titanium dioxide particles into a binder, which can allow the transport of photogenerated electrons and may eliminate any pin holes due to incomplete coverage. In certain situations, a high concentration of titanium dioxide in the blocking layer is desirable. However, the dispersion quality such as particle size distribution may be significantly worse at a high titanium dioxide concentration. Poor dispersions often cause coating defects such as streak and coating non-uniformity. The dispersion quality of titanium dioxide depends on the binder and solvent employed. Conventional binders and solvents may be unsuitable at a high concentration of the titanium dioxide. In addition, some conventional binders are soluble in the solutions coated onto the substrate after the blocking layer such as the solutions for the charge generating layer and the charge transport layer. Such a solubility allows intermixing of layers that results in electrical and print quality problems. Thus, there is a need, which the present invention addresses, for new binders for the blocking layer of a photoreceptor that minimize or eliminate the problems of conventional binders described herein.
The phrases “charge blocking layer” and “blocking layer” are generally used interchangeably with the phrase “undercoat layer.”
Conventional photoreceptors and their materials are dislosed in Katayama et al., U.S. Pat. No. 5,489,496; Yashiki, U.S. Pat. No. 4,579,801; Yashiki, U.S. Pat. No. 4,518,669; Seki et al., U.S. Pat. No. 4,775,605; Kawahara, U.S. Pat. No. 5,656,407; Markovics et al., U.S. Pat. No. 5,641,599; Monbaliu et al., U.S. Pat. No. 5,344,734; Terrell et al., U.S. Pat. No. 5,721,080; and Yoshihara, U.S. Pat. No. 5,017,449.
Conventional charge blocking layers are also disclosed in U.S. Pat. No. 4,464,450; U.S. Pat. No. 5,449,573; U.S. Pat. No. 5,385,796; and Obinata et al, U.S. Pat. No. 5,928,824.
Poly(vinylbenzyl alcohol) is described in Jones, U.S. Pat. No. 3,879,328.
Copending application, Ser. No. 09/320,869 now U.S. Pat. No. 6,132,912, is directed to a photoreceptor having an undercoat layer generated from a mixture of a polyhydroxyalkylacrylate and an aminoalkyltrialkoxysilane.
SUMMARY OF THE INVENTION
The present invention is accomplished in embodiments by providing a photoreceptor including:
(a) a substrate;
(b) a charge blocking layer comprising a polymer polymerized from at least one monomer including vinylbenzyl alcohol monomer; and
(c) at least one imaging layer.
REFERENCES:
patent: 3879328 (1975-04-01), Jones
patent: 4464450 (1984-08-01), Teuscher
patent: 4518669 (1985-05-01), Yashiki
patent: 4579801 (1986-04-01), Yashiki
patent: 4775605 (1988-10-01), Seki et al.
patent: 5017449 (1991-05-01), Yoshihara
patent: 5279934 (1994-01-01), Smith et al.
patent: 5344734 (1994-09-01), Monbaliu et al.
patent: 5385796 (1995-01-01), Spiewak et al.
patent: 5449573 (1995-08-01), Aoki et al.
patent: 5489496 (1996-02-01), Katayama et al.
patent: 5641599 (1997-06-01), Markovics et al.
patent: 5656407 (1997-08-01), Kawahara
patent: 5721080 (1998-02-01), Terrell et al.
patent: 5874193 (1999-02-01), Liu et al.
patent: 5928824 (1999-07-01), Obinata et al.
Chambers John S.
Cherniack Helen R.
Fuller Timothy J.
Hammond Harold F.
Pai Damodar M.
Goodrow John
Soong Zosan S.
Xerox Corporation
LandOfFree
Photoreceptor with poly (vinylbenzyl alcohol) does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Photoreceptor with poly (vinylbenzyl alcohol), we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Photoreceptor with poly (vinylbenzyl alcohol) will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2460254