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 .
Response to Arguments
Applicant’s arguments regarding the construction of the obviousness rejection in the prior office action (non-final rejection, dated 2025-10-27), see Remarks filed 2026-01-15, with respect to the rejections of claims 1, 3 - 5, and 7 under 35 U.S.C. §103 have been fully considered and are persuasive. Therefore, the rejection has been withdrawn. In particular, Applicant is correct in asserting that it would not have been obvious for one of ordinary skill in the art to omit the alumina particles of Obara as an external additive, and therefore any two-component developer prepared following the teachings of Obara as a primary reference would not possess the limitation of the external additive consisting of silica and/or titania particles, as recited in Claim 1. However, upon further consideration, a new ground of rejection is made in view of Yamada et al, in view of Kaneeda et al, further in view of Obara et al.
As to Applicant’s assertion of unexpected results arising from the claimed surface-modification of the externally added inorganic particles, that argument is not convincing in view of the teachings of at least Kaneeda et al as detailed in the rejection below. The evaluations disclosed in the Specification of the instant application are evaluation of fog and image density variation (Specification, Table 7 and Table 8). Generation of fog results from a drop in the toner charge amount under high-humidity conditions, and a decrease in image density results from overcharge of the toner under low-humidity conditions. The very aim of Kaneeda’s invention is to prepare hydrophobic silica powder which is insensitive to environmental humidity, and can thus impart stable charging properties to a toner, enhancing the stability and quality of printed images (Abstract). Kaneeda describes the importance of charge stability of toner under both low-humidity and high-humidity environments, which is controlled in large part by external additives ([0004]). In addition, Kaneeda evaluates preparative examples for the stability of their charge under both low-humidity and high-humidity conditions ([0046]). Where a practitioner of ordinary skill in the art would have been taught by Kaneeda to optimize for charge stability of the toner under wide-ranging humidity conditions, suppression of fogging and improvement of image density stability would have necessarily flowed from such optimization. Therefore, the evaluations disclosed for Applicant’s preparative examples do not constitute unexpected results.
Claim Rejections - 35 USC § 103
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
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 and 3 – 5 are rejected under 35 U.S.C. 103 as being unpatentable over Yamada et al (US PGP 2020/0081362) in view of Kaneeda et al (US PGP 2017/0168409), further in view of Obara et al (US PGP 2019/0354032).
Yamada teaches a toner including at least a binder resin and a colorant (Abstract). The base particles of the toner have an external additive ([0194]), which may be silica or titania particles, and which may be used alone or in combination ([0195]). The externally added particles are preferably hydrophobized by a surface treatment agent ([0199]). Yamada teaches that the toner may be mixed with a carrier and used as a two-component developer ([0267]). Yamada does not appear to teach silane coupling agents having linear alkyl groups of 2 – 4 carbons as hydrophobizing agents for the externally added metal oxide particles.
Kaneeda teaches a hydrophobic silica powder for use as an external additive with toner particles (Abstract, [0007]). The hydrophobic silica of Kaneeda imparts upon the toner to which it is externally added stable charging property leading to stable quality of printed images ([0015]). Kaneeda teaches hydrophobically surface-treating the silica with silane coupling agents ([0024]). Among the examples of silane coupling agents given by Kaneeda are: ethyl(triethoxy)silane, ethyl(trichloro)silane, ethyl(trimethoxy)silane, butyl(triethoxy)silane, butyl(trimethoxy)silane, propyl(triethoxy)silane, propyl(trimethoxy)silane, diethyl(diethoxy)silane, diethyl(dimethoxy)silane, triethyl(ethoxy)silane, triethyl(chloro)silane, triethyl(methoxy)silane, tripropyl(ethoxy)silane, tripropyl(chloro)silane, and tripropyl(methoxy)silane ([0028]), all of which read on Formula (1) of Claim 1. Neither of Yamada or Kaneeda appears to teach the iron element content on the surface of a carrier particle.
Obara teaches a two-component developer, including a toner base particle bearing an external additive, and a carrier particle, which includes a core material and a covering section, analogous to a shell portion ([Abstract]). Obara teaches that the exposed area of the core material particle of the carrier, analogous to the iron element content measured by XPS in the instant application, is preferably 4 – 15% ([0023]), the same as the range given by Expression (1) in Claim 1. Obara teaches that having the exposed area greater than 4% prevents too high of adhesion between the toner particle and the carrier particle, which would deteriorate the turnover of toner particles and lead to fogging and poor image quality. Further, having the exposed area less than 15% prevents a reduction in the amount of charge of the toner particle, which would lead to deteriorated image quality ([0023]). Obara measures the exposed area of the core material particle by a substantially identical method to that used in the present application to measure the iron element content in the instant application. That is, Obara compares the amount of iron measured by XPS to the amount of carbon measured by XPS on the surface of the carrier particle ([0024]). In addition, Obara exemplifies the production of a Carrier Particle 1 ([0188] – [0189]) by a method substantially identical to that for the production of Carrier Particles 3 of the instant application (Specification, [0285]). Obara reports an exposed area for the resultant carrier particle of 8.2% ([0189]), the same value as that reported for the iron element content Carrier Particles 3 of the instant application (Specification, page 47, Table 3), supporting the interpretation that these differently named parameters are in fact the same measurement.
In preparing the toner of Yamada, one of ordinary skill in the art would have been motivated to enhance the charging properties of the toner particles by treating the externally added metal oxide particles (which may be silica and/or titania) as taught by Kaneeda. One of ordinary skill in the art would have been motivated to also suppress image fogging and enhance image quality by using such a toner as part of a two-component developer alongside the carrier taught by Obara. 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 a two-component developer comprising the toner of Yamada, wherein the externally added silica and/or titania particles are surface-treated as taught by Kaneeda, and the carrier of Obara, resulting in a two-component developer satisfying Claim 1.
Obara teaches that the preferable shape factor, SF-1, of the core material particles of the carrier is 115 – 150, the same as the range of Claim 3.
Obara points out the option of preparing a core-shell structured toner particle ([0116]), and then details the steps of such a procedure ([0117] – [0124]). In addition, an exemplified toner base particle of Obara has a core-shell structure ([0156]), satisfying Claim 4.
Obara teaches that the binder resin of the toner base particle preferably contains 50 – 80% by mass of amorphous resin ([0073]), and that the content of vinyl resin in the amorphous resin is preferably more than 50% by mass ([0072]). Obara forms the exemplified core-shell structured toner particle from a core containing 87% by mass of “resin fine particle SPI” ([0156]), which is an amorphous vinyl resin ([138] – [147]), and a shell composed entirely of “resin fine particle D1”, which is an amorphous polyester resin ([0150] – [0154]). Therefore, the core-shell toner particle of Obara has a core with an amorphous vinyl resin as a main component, and a shell with an amorphous polyester resin as a main component, satisfying Claim 5.
Claim 7 is rejected under 35 U.S.C. 103 as being unpatentable over Yamada et al (US PGP 2020/0081362) in view of Kaneeda et al (US PGP 2017/0168409), further in view of Obara et al (US PGP 2019/0354032), further in view of Horiuchi et al (US PGP 2011/0287353).
The above discussions of Yamada, Obara, and Kaneeda are incorporated herein.
Neither Obara nor Kaneeda appears to teach an image forming apparatus. Yamada discloses an image forming apparatus, but does not teach a cleaning unit.
Horiuchi teaches an image forming apparatus ([0307]) which contains at least: a charging unit that charges an electrostatic image bearing member ([0313]); a latent electrostatic image bearing member and a latent electrostatic image forming means ([0311] – [0312]); a developing unit ([0325]); a transferring unit ([0332]); a fixing apparatus ([0335]); and a cleaning means ([0342]). Horiuchi teaches that the apparatus may be used with a one-component or two-component developer ([0328]).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the instant application to use the two-component developer comprising the toner of Yamada, wherein the externally added silica and/or titania particles are surface-treated as taught by Kaneeda, and the carrier of Obara, with the image forming apparatus of Horiuchi, satisfying Claim 7.
Conclusion
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/GRANT STEVEN SEILER/Examiner, Art Unit 1734
/PETER L VAJDA/Primary Examiner, Art Unit 1737 02/20/2026