Patent Application
20070292793
An imaging member was prepared by providing a 0.02 micrometer thick titanium layer coated (the coater device) on a biaxially oriented polyethylene naphthalate substrate (KALEDEX™ 2000) having a thickness of 3.5 mils, and applying thereon, with a gravure applicator, a solution containing 50 grams of 3-amino-propyltriethoxysilane, 41.2 grams of water, 15 grams of acetic acid, 684.8 grams of denatured alcohol, and 200 grams of heptane. This layer was then dried for about 5 minutes at 135° C. in the forced air dryer of the coater. The resulting blocking layer had a dry thickness of 500 Angstroms. An adhesive layer was then prepared by applying a wet coating over the blocking layer, using a gravure applicator, and which adhesive contains 0.2 percent by weight based on the total weight of the solution of copolyester adhesive (ARDEL D100™ available from Toyota Hsutsu Inc.) in a 60:30:10 volume ratio mixture of tetrahydrofuran/monochlorobenzene/methylene chloride. The adhesive layer was then dried for about 5 minutes at 135° C. in the forced air dryer of the coater. The resulting adhesive layer had a dry thickness of 200 Angstroms.
A photogenerating layer dispersion was prepared by introducing 0.45 grams of the known polycarbonate LUPILON 200™ (PCZ-200) or POLYCARBONATE Z™, weight average molecular weight of 20,000, available from Mitsubishi Gas Chemical Corporation, and 50 milliliters of tetrahydrofuran into a 4 ounce glass bottle. To this solution were added 2.4 grams of hydroxygallium phthalocyanine (Type V) and 300 grams of ⅛-inch (3.2 millimeters) diameter stainless steel shot. This mixture was then placed on a ball mill for 8 hours. Subsequently, 2.25 grams of PCZ-200 were dissolved in 46.1 grams of tetrahydrofuran, and added to the hydroxygallium phthalocyanine dispersion. This slurry was then placed on a shaker for 10 minutes. The resulting dispersion was, thereafter, applied to the above adhesive interface with a Bird applicator to form a photogenerating layer having a wet thickness of 0.25 mil. A strip about 10 millimeters wide along one edge of the substrate web bearing the blocking layer and the adhesive layer was deliberately left uncoated by any of the photogenerating layer material to facilitate adequate electrical contact by the ground strip layer that was applied later. The charge generation layer was dried at 135° C. for 5 minutes in a forced air oven to form a dry photogenerating layer having a thickness of 0.4 micrometer.
The resulting imaging member web was then overcoated with a two-layer charge transport layer. Specifically, the photogenerating layer was overcoated with a charge transport layer (the bottom layer) in contact with the photogenerating layer. The bottom layer of the charge transport layer was prepared by introducing into an amber glass bottle in a weight ratio of 1:1 N,N′-diphenyl-N,N′-bis(3-methylphenyl)-1,1′-biphenyl-4,4′-diamine, and MAKROLON 5705®, a known polycarbonate resin having a molecular weight average of from about 50,000 to 100,000, commercially available from Farbenfabriken Bayer A.G. The resulting mixture was then dissolved in methylene chloride to form a solution containing 15 percent by weight solids. This solution was applied on the photogenerating layer to form the bottom layer coating that upon drying (120° C. for 1 minute) had a thickness of 14.5 microns. During this coating process, the humidity was equal to or less than 15 percent.
The bottom layer of the charge transport layer was then overcoated with a top layer. The charge transport layer solution of the top layer was prepared as described above for the bottom layer. This solution was applied on the bottom layer of the charge transport layer to form a coating that upon drying (120° C. for 1 minute) had a thickness of 14.5 microns. During this coating process the humidity was equal to or less than 15 percent.
An imaging member was prepared by repeating the process of Comparative Example 1 except that to the photogenerating layer dispersion of Comparative Example 1 were added 0.24 grams of zinc dialkyldithiophosphate (ZDDP ELCO-103™, wherein alkyl is a mixture of primary and secondary propyl, butyl and pentyl), commercially available from Elco Corporation.
An imaging member was prepared by repeating the process of Comparative Example 1 except that to the photogenerating layer dispersion of Comparative Example 1 were added 0.24 grams of zinc dialkyldithiophosphate (ZDDP ELCO-102™, wherein alkyl is a mixture of primary butyl and octyl), commercially available from Elco Corporation.
An imaging member was prepared by repeating the process of Comparative Example 1 except that to the photogenerating layer dispersion of Comparative Example 1 were added 0.72 grams of the above zinc dialkyldithiophosphate (ZDDP ELCO-103™), commercially available from Elco Corporation.
An imaging member was prepared by repeating the process of Comparative Example 1 except that (1) the top layer of the charge transport layer was prepared by introducing into an amber glass bottle in a weight ratio of 1:1:0.1 N,N′-diphenyl-N,N′-bis(3-methylphenyl)-1,1′-biphenyl-4,4′-diamine, MAKROLON 5705®, a polycarbonate resin having a molecular weight (weight average molecular weight) of from about 50,000 to about 100,000, commercially available from Farbenfabriken Bayer A.G, and IRGANOX 1010™, tetrakis methylene(3,5-di-tert-butyl-4-hydroxy hydrocinnamate), commercially available from Ciba Specialty Chemical. The resulting mixture was dissolved in methylene chloride to form a solution containing 15 percent by weight solids. (2) Further, to the photogenerating layer dispersion of Comparative Example 1 are added 0.24 grams of zinc dialkyldithiophosphate (ZDDP ELCO-103™), commercially available from Elco Corporation.
An imaging member was prepared by repeating the process of Comparative Example 1 except that (1) the top layer of the charge transport layer was prepared by introducing into an amber glass bottle in a weight ratio of 1:1:0.1 N,N′-diphenyl-N,N′-bis(3-methylphenyl)-1,1′-biphenyl-4,4′-diamine, MAKROLON 5705®, a polycarbonate resin having a molecular weight of from about 50,000 to about 100,000, commercially available from Farbenfabriken Bayer A.G, and IRGANOX 1010™ commercially available from Ciba Specialty Chemical. The resulting mixture was dissolved in methylene chloride to form a solution containing 15 percent by weight solids. (2) Further, to the photogenerating layer dispersion of Comparative Example 1 was added 0.72 grams of zinc dialkyldithiophosphate (ZDDP ELCO-103™), commercially available from Elco Corporation.
The above prepared six photoreceptor devices were tested in a scanner set to obtain photoinduced discharge cycles, sequenced at one charge-erase cycle followed by one charge-expose-erase cycle, wherein the light intensity was incrementally increased with cycling to produce a series of photoinduced discharge characteristic (PIDC) curves from which the photosensitivity and surface potentials at various exposure intensities were measured. Additional electrical characteristics were obtained by a series of charge-erase cycles with incrementing surface potential to generate several voltage versus charge density curves. The scanner is equipped with a scorotron set to a constant voltage charging at various surface potentials. The devices were tested at surface potentials of 500 with the exposure light intensity incrementally increased by means of regulating a series of neutral density filters; the exposure light source is a 780 nanometer light emitting diode. A xerographic simulation was completed in an environmentally controlled light tight chamber at ambient conditions (40 percent relative humidity and 22° C.). The devices were also cycled for 10,000 cycles electrically with charge-discharge-erase. Twelve photoinduced discharge characteristic (PIDC) curves were generated, one for each of the above prepared photoconductors at both cycle=0 and cycle=10,000. The results are summarized in the table that follows.
In embodiments there is disclosed a number of improved characteristics for the photoconductive members as determined by the generation of known PIDC curves, such as minimization or prevention of Vr cycle up by the physical doping of the thiophosphate like the above dialkyldithiophosphate in the photogenerating layer. More specifically, in the above Table, V (3.5 ergs/cm2) represents surface potential of the device when exposure is 3.5 ergs/cm2, and is used to characterize the PIDC. Incorporation of the thiophosphate into the photogenerating layer reduces V (3.5 ergs/cm2), and prevents cycle up with extended cycling.
Also, in embodiments, incorporation of the thiophosphate into the photogenerating layer can result in a photoconductor with improved, that is reduced, ghosting as compared to the comparative Example 1 member.
The claims, as originally presented and as they may be amended, encompass variations, alternatives, modifications, improvements, equivalents, and substantial equivalents of the embodiments and teachings disclosed herein, including those that are presently unforeseen or unappreciated, and that, for example, may arise from applicants/patentees and others. Unless specifically recited in a claim, steps or components of claims should not be implied or imported from the specification or any other claims as to any particular order, number, position, size, shape, angle, color, or material.
U.S. application Ser. No. (not yet assigned) (Attorney Docket No. 20060179-US-NP), filed concurrently herewith, on Ether Containing Photoconductors, by Jin Wu et al. U.S. application Ser. No. (not yet assigned) (Attorney Docket No. 20060491-US-NP), filed concurrently herewith, on Ether Phosphate Containing Photoconductors, by Jin Wu et al. U.S. application Ser. No. (not yet assigned) (Attorney Docket No. 20060490-US-NP), filed concurrently herewith, on Ether Phosphate Containing Photoconductors, by Jin Wu et al. U.S. application Ser. No. (not yet assigned) (Attorney Docket No. 20060180-US-NP), filed concurrently herewith, on Polyphenyl Ether Containing Photoconductors, by Jin Wu et al. U.S. application Ser. No. (not yet assigned) (Attorney Docket No. 20060489-US-NP), filed concurrently herewith, on Polyphenyl Ether Phosphate Containing Photoconductors, by Jin Wu et al. U.S. application Ser. No. (not yet assigned) (Attorney Docket No. 20060488-US-NP), filed concurrently herewith, on Polyphenyl Ether Phosphate Containing Photoconductors, by Jin Wu et al. U.S. application Ser. No. (not yet assigned) (Attorney Docket No. 20060181-US-NP), filed concurrently herewith, on Polyphenyl Thioether Containing Photoconductors, by Jin Wu et al. U.S. application Ser. No. (not yet assigned) (Attorney Docket No. 20060487-US-NP), filed concurrently herewith, on Polyphenyl Thioether Phosphate Containing Photoconductors, by Jin Wu et al. U.S. application Ser. No. (not yet assigned) (Attorney Docket No. 20060486-US-NP), filed concurrently herewith, on Polyphenyl Thioether Phosphate Containing Photoconductors, by Jin Wu et al. U.S. application Ser. No. (not yet assigned) (Attorney Docket No. 20060137-US-NP), filed concurrently herewith, on Thiophosphate Containing Photoconductors, by Jin Wu et al. U.S. application Ser. No. (not yet assigned) (Attorney Docket No. 20060146-US-NP), filed concurrently herewith, on Thiophosphate Containing Photoconductors, by Jin Wu et al. The following patents and copending commonly assigned patent applications are recited: U.S. patent application Ser. No. 11/126,664, filed May 11, 2005, (Attorney Docket 20050144-US-NP) entitled Photoconductive Members; U.S. patent application Ser. No. 11/193,242, filed Jul. 28, 2005, (Attorney Docket 20050226-US-NP) entitled Polytetrafluoroethylene-doped Photoreceptor Layer Having Polyol Ester Lubricants; U.S. patent application Ser. No. 11/193,541, filed Jul. 28, 2005, (Attorney Docket 20050226Q-US-NP) entitled Photoreceptor Layer Having Solid and Liquid Lubricants; U.S. patent application Ser. No. 11/193,672, filed Jul. 28, 2005, (Attorney Docket 20050226Q1-US-NP) entitled Photoreceptor Layer having Polyphenyl Ether Lubricant; U.S. patent application Ser. No. 11/193,241, filed Jul. 28, 2005, (Attorney Docket 20050226Q2-US-NP) entitled Photoreceptor Layer Having Dialkyldithiophosphate Lubricant; U.S. patent application Ser. No. 11/193,129, filed Jul. 28, 2005, (Attomey Docket 20050626-US-NP) entitled Photoreceptor Layer having Phosphate-based Lubricant; and U.S. patent application Ser. No. 11/193,754, filed Jul. 28, 2005, (Attorney Docket 20050626Q-US-NP) entitled “Photoreceptor Layer having Antioxidant Lubricant Additives.” The disclosures of each of these applications are totally incorporated herein by reference in their entireties. There is illustrated in U.S. Pat. No. 7,037,631, the disclosure of which is totally incorporated herein by reference, a photoconductive imaging member comprised of a supporting substrate, a hole blocking layer thereover, a crosslinked photogenerating layer and a charge transport layer, and wherein the photogenerating layer is comprised of a photogenerating component and a vinyl chloride, allyl glycidyl ether, hydroxy containing polymer. There is illustrated in U.S. Pat. No. 6,913,863, the disclosure of which is totally incorporated herein by reference, a photoconductive imaging member comprised of a hole blocking layer, a photogenerating layer, and a charge transport layer, and wherein the hole blocking layer is comprised of a metal oxide; and a mixture of a phenolic compound and a phenolic resin wherein the phenolic compound contains at least two phenolic groups. A number of the components and amounts thereof of the above copending applications and patents, such as the supporting substrates, resin binders, photogenerating layer components, antioxidants, charge transport components, ethers, thiophosphates, hole blocking layer components, adhesive layers, and the like may be selected for the members of the present disclosure in embodiments thereof.
