DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claims 1 - 20 are rejected under 35 U.S.C. 103 as being unpatentable over Sasaki et al (US PGP 2023/0107087) in view of Yamazaki (US PGP 2004/0126688), further in view of Okura et al (US PGP 2009/0317733).
Sasaki teaches an electrophotographic photoreceptor including a conductive substrate and a lamination-type photosensitive layer, which comprises a charge generation layer and a charge transport layer (Abstract). The charge transport layer contains a charge transport material and a polyester resin (1), wherein the polyester resin contains a dicarboxylic acid unit of a formula (A) and a diol unit of a formula (B) ([0032]). Sasaki gives as specific examples of dicarboxylate units which may be used structures (A-1) – (A-13) ([0093]), of which the structural unit of formula (A-12) is the same as instant unit (A2-3). Structures (B-1) – (B-38) are given as specific examples of diol units which may be used ([0123]), of which structural unit (B-24) is the same as instant unit (B1-4).
The polyester resin, which is the binder resin of the charge transport layer ([0268]), preferably has a weight-average molecular weight of 50,000 – 400,000 ([0032]), encompassing the range stated in Claim 1. Sasaki further teaches that the polydispersity of the polyester resin (1), which is expressed as a ratio of the weight-average molecular weight and the number-average molecular weight (Mw/Mn), is preferably in the range of 2.1 – 4.0 ([0049]). Where the ratio Mw/Mn is controlled above 2.1, the dispersion uniformity of the charge transport material is enhanced ([0054]). Where the ratio Mw/Mn is controlled below 4.0, the abrasion resistance of the charge transport layer is enhanced ([0055]).
Sasaki does not appear to teach a molecular weight distribution of the binder resin of the charge transport layer having two or more peaks.
Okura teaches a photosensitive member comprising a photosensitive layer (Abstract). The photosensitive layer is composed of a charge generating layer and a charge transport layer ([0043]). The charge transport layer comprises a charge transport material dispersed in a binder resin ([0051). Okura teaches that the binder resin of the charge transport layer may be a polyester resin, and that it is possible to mix two resins of the same type which have differing molecular weights ([0057]).
Yamazaki teaches an electrophotographic photoconductor comprising at least a conductive substrate, a charge generating layer, and a charge transport layer (Abstract). The charge generating layer is composed of at least a charge generating material and a binder resin, wherein the binder resin has a preferred ratio of the weight-average molecular weight and the number-average molecular weight (Mw/Mn) ([0017]). Yamazaki achieves the preferred polydispersity and weight-average molecular weight of the above-mentioned binder resin by mixing two or more resins of the same type having different molecular weights ([0020], [0023]). Yamazaki teaches that this method gives better control of the polydispersity of the binder resin, and allows stability in mass production ([0023]).
In preparing the photoreceptor of Sasaki, one of ordinary skill in the art would have been taught by Okura that the binder resin of a charge transport layer may be composed of two or more resins of the same type having different molecular weights. In addition, the skilled practitioner would have been taught by Yamazaki that mixing at least two resins of the same type but having different molecular weights is a preferable method of controlling the polydispersity of the binder resin in a layer of a photoreceptor. Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the instant application to prepare the electrophotographic photoreceptor of Sasaki, wherein the polydispersity and weight-average molecular weight of the polyester binder resin of the charge transport layer is controlled by mixing at least two resins of the same kind having different molecular weights as taught by Yamazaki. The resulting binder resin of the charge transport layer would thus possess at least two peaks in the molecular weight distribution curve. In the course of experimentation targeting dispersion uniformity of the charge transport material and abrasion resistance of the charge transport layer, the binder resin of the charge transport layer would also possess a value for the ratio (Mmax – Mmin) / Mw in the range stated in Claim 1 and Claim 2.
As discussed above, Sasaki teaches a preferred weight-average molecular weight of the binder resin of the charge transport layer of 50,000 – 400,000, encompassing the range stated in Claim 3.
As discussed above, Sasaki exemplifies a structural unit of formula (A-12), which is the same as instant unit (A2-3), reading on Claim 4 and Claim 5.
As discussed above, Sasaki exemplifies a structural unit of (B-24), which is the same as instant unit (B1-4), reading on Claim 6 and Claim 7.
Sasaki describes an embodiment of the photoreceptor described above, wherein the photosensitive layer is a single layer-type photosensitive layer disposed on the conductive substrate ([0029]). Sasaki gives the same preferences for the value of the ratio Mw/Mn ([0050]) and the weight-average molecular weight ([0033]) of the polyester binder resin of the single layer-type photosensitive layer as for the binder resin of the charge transport layer discussed above. Therefore, in the course of experimentation targeting dispersion uniformity of the charge transport material and abrasion resistance of the single layer-type photosensitive layer, the binder resin of the photosensitive layer would also possess a value for the ratio (Mmax – Mmin)/Mw in the range stated in Claim 8 and Claim 9.
As discussed above, Sasaki teaches a preferred weight-average molecular weight for the polyester resin of the single layer-type photosensitive of 50,000 – 400,000 ([0033]), encompassing the range stated in Claim 10.
As discussed above, Sasaki exemplifies a structural unit of formula (A-12), which is the same as instant unit (A2-3), reading on Claim 11 and Claim 12.
As discussed above, Sasaki exemplifies a structural unit of (B-24), which is the same as instant unit (B1-4), reading on Claim 13 and Claim 14.
Sasaki teaches a process cartridge including the photoreceptor described above, which is attachable to and detachable from an image forming apparatus ([0320]), satisfying Claim 15, Claim 16, Claim 17, Claim 18, and Claim 19.
Sasaki teaches an image forming apparatus including the photoreceptor described above; a charging unit; an image forming unit; a developing unit; and a transfer unit ([0316]), satisfying Claim 20.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Grant S Seiler whose telephone number is (571)272-3015. The examiner can normally be reached 9:30 - 5:30 Pacific.
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/GRANT STEVEN SEILER/ Examiner, Art Unit 1734
/JONATHAN JOHNSON/ Supervisory Patent Examiner, Art Unit 1734
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