Radiation imagery chemistry: process – composition – or product th – Electric or magnetic imagery – e.g. – xerography,... – Radiation-sensitive composition or product
Reexamination Certificate
2002-05-17
2004-03-30
Chapman, Mark A. (Department: 1756)
Radiation imagery chemistry: process, composition, or product th
Electric or magnetic imagery, e.g., xerography,...
Radiation-sensitive composition or product
Reexamination Certificate
active
06713220
ABSTRACT:
RELATED PATENTS
Illustrated in U.S. Pat. No. 5,756,245, the disclosure of which is totally incorporated herein by reference, is a photoconductive imaging member comprised of a hydroxygallium phthalocyanine photogenerator layer, a charge transport layer, a barrier layer, a photogenerator layer comprised of a mixture of bisbenzimidazo(2,1-a-1′,2′-b)anthra(2,1,9-def:6,5, 10-d′e′f′)diisoquinoline-6, 11-dione and bisbenzimidazo(2,1-a:2′,1′-a)anthra(2,1,9-def:6,5,10-d′e′f′)diisoquinoline-10,21-dione, and thereover a charge transport layer.
Illustrated in U.S. Pat. No. 5,521,306, the disclosure of which is totally incorporated herein by reference, is a process for preparation of Type V hydroxygallium phthalocyanine comprising the in situ formation of an alkoxy-bridged gallium phthalocyanine dimmer, hydrolyzing the dimmer to hydroxygallium phthalocyanine and subsequently converting the hydroxygallium phthalocyanine product to Type V hydroxygallium phthalocyanine.
Illustrated in U.S. Pat. No. 5,482,811, the disclosure of which is totally incorporated herein by reference, is a process for the preparation of hydroxygallium phthalocyanine which comprises hydrolyzing a gallium phthalocyanine precursor pigment by dissolving said hydroxygallium phthalocyanine in a strong acid and then reprecipitating the resulting dissolved pigment in basic aqueous media; removing any ionic species formed by washing with water, concentrating the resulting aqueous slurry comprised of water and hydroxygallium phthalocyanine to a wet cake; removing water from said slurry by azeotropic distillation with an organic solvent, and subjecting said resulting pigment slurry to mixing with the addition of a second solvent to cause the formation of said hydroxygallium phthalocyanine polymorphs.
Also, in U.S. Pat. No. 5,473,064, the disclosure of which is totally incorporated herein by reference, there is illustrated a process for the preparation of hydroxygallium phthalocyanine Type V, essentially free of chlorine, whereby a pigment precursor Type I chlorogallium phthalocyanine is prepared by reaction of gallium chloride in a solvent, such as N-methylpyrrolidone, present in an amount of from about 10 parts to about 100 parts, and preferably about 19 parts with 1,3-diiminoisoindolene (DI
3
) in an amount of from about 1 part to about 10 parts, and preferably about 4 parts of DI
3
, for each part of gallium chloride that is reacted; hydrolyzing said pigment precursor chlorogallium phthalocyanine Type I by standard methods, for example acid pasting, whereby the pigment precursor is dissolved in concentrated sulfuric acid and then reprecipitated in a solvent, such as water, or a dilute ammonia solution, for example from about 10 to about 15 percent; and subsequently treating the resulting hydrolyzed pigment hydroxygallium phthalocyanine Type I with a solvent, such as N,N-dimethylformamide, present in an amount of from about 1 volume part to about 50 volume parts and preferably about 15 volume parts for each weight part of pigment hydroxygallium phthalocyanine that is used by, for example, ball milling the Type I hydroxygallium phthalocyanine pigment in the presence of spherical glass beads, approximately 1 millimeter to 5 millimeters in diameter, at room temperature, about 25° C., for a period of from about 12 hours to about 1 week, and preferably about 24 hours.
The appropriate components, and processes of the above recited patents may be selected for the present invention in embodiments thereof.
BACKGROUND OF THE INVENTION
This invention is generally directed to imaging members, and more specifically, the present invention is directed to photoconductive imaging members with, for example, improved resistance to light shock and a method of using the imaging member. Light shock refers, for example, to a phenomena in which a photoresponsive imaging member when exposed to room light exhibits an increase in dark decay, depletion, increased sensitivity, collapse of the photoinduced discharge curve (PIDC) tail, and reduced residual potential V
residual
. The exposure to room light, may occur, for example, during installation of the photoreceptor or during servicing of a machine, such as a xerographic machine. Thus, for example, during belt replacement or machine maintenance, nonuniform exposure of the photoreceptor to room light can result in nonuniformity in the electrical properties of the imaging member. A difference in electrical properties between exposed areas of an imaging member is undesirable because it can cause nonuniform image potentials which in turn leads to the formation of nonuniform toner images when the light shocked imaging member is subsequently utilized for electrophotographic imaging. More specifically, the present invention relates to imaging members containing a dopant in the charge transport layer, and wherein the charge generation layer is resistant to or there is an avoidance of light shock, especially at from about 400 to 500 nanometers of light, and which light can adversely affect the photogenerating pigments present in the charge generating layer. In embodiments, the dopant or additive component added or contained in the transport layer absorbs light of wavelength less than about 700 nanometers. In embodiments the dopant or additive component added or contained in the transport layer absorbs light with a wavelength shorter than about 460 nanometers; and also wherein the dopant or additive component present in the charge transport layer is a diphenoquinone, which for example will prevent or minimize any light with a wavelength between about 400 nanometers to about 460 nanometers from interacting with the photogenerating layer. Examples of photogenerating pigments include hydroxygallium phthalocyanines, such as Type V hydroxygallium phthalocyanine. Processes of imaging, especially xerographic imaging, and printing, including digital, are also encompassed by the present invention.
Also, more specifically, the layered photoconductive imaging members of the present invention can be selected for a number of different known imaging and printing processes including, for example, multicopy/fax devices, electrophotographic imaging processes, especially xerographic imaging and printing processes wherein negatively charged or positively charged images are rendered visible with toner compositions of an appropriate charge polarity. The imaging members are in embodiments sensitive in the wavelength region of, for example, from about 400 to about 900 nanometers, and in particular, from about 550 to about 830 nanometers, thus IR diode lasers can be selected as the light source. Moreover, the imaging members of the present invention in embodiments can be selected for color xerographic imaging applications where several color printings can be achieved in a single pass.
REFERENCES
Layered photoresponsive imaging members have been described in a number of U.S. patents, such as U.S. Pat. No. 4,265,990, the disclosure of which is totally incorporated herein by reference, wherein there is illustrated an imaging member comprised of a photogenerating layer, and an aryl amine hole transport layer. Examples of photogenerating layer components include trigonal selenium, metal phthalocyanines, vanadyl phthalocyanines, and metal free phthalocyanines. Additionally, there is described in U.S. Pat. No. 3,121,006 a composite xerographic photoconductive member comprised of finely divided particles of a photoconductive inorganic compound dispersed in an electrically insulating organic resin binder. The binder materials disclosed in the '006 patent comprise a material which is incapable of transporting for any significant distance injected charge carriers generated by the photoconductive particles.
Further, in U.S. Pat. No. 4,555,463, the disclosure of which is totally incorporated herein by reference, there is illustrated a layered imaging member with a chloroindium phthalocyanine photogenerating layer. In U.S. Pat. No. 4,587,189, the disclosure of which is totally incorp
Duff James M.
Graham John F.
Hor Ah-Mee
Mishra Satchidanand
Popovic Zoran D.
Chapman Mark A.
Palazzo E. O.
Xerox Corporation
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