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 filed 2025-12-24 have been fully considered but they are not persuasive.
In regard to the rejection under 35 U.S.C. §102(a) in the prior office action (non-final rejection dated 2025-10-08), Applicant asserts that Watanabe does not disclose the nitrogen-containing silica particles recited in Claim 1, and does not teach the technical effects of the claimed invention.
First, where a technical effect of the invention (namely, charge retention performance) is not recited in Claim 1, such an effect has no bearing on whether a prior art reference discloses or teaches the claimed chemical or structural features of an invention. Second, while Watanabe does not appear to name “nitrogen-containing silica particles” by the identical terminology of Claim 1, Watanabe does disclose structural features which amount to the same thing. In particular, as discussed in the prior office action and in the rejections below, Watanabe teaches the treatment of silica particles with hexamethyldisilazane (HMDS), a nitrogenous compound. The silica particles would thus contain nitrogen, and would plainly constitute the “nitrogen-containing silica particles” of Claim 1.
In regard to the rejection under 35 U.S.C. §103 in the prior office action, Applicant asserts that it would not be obvious to combine the teachings of Anno with those of Watanabe, if the result would diminish the performance of the carrier or Watanabe. A hypothetical example wherein a resin coating thickness of the carrier is set to the lower limit taught by Anno (0.1 µm), which would result in a ratio D/T above the claimed range. Applicant then explains that such an embodiment would result in diminution of the performance of the carrier of Watanabe. Therefore, it appears that, by Applicant’s own argument, a practitioner of ordinary skill in the art would not be motivated to select combinations of values in the ranges taught by Anno and Watanabe which result in values of D/T outside the claimed range, but would instead have good reason to select values in those ranges which result in values of D/T inside the range recited in Claim 5.
Finally, Applicant argues that the claimed range for the size of the resin fine particles of 100 – 250 nm recited in Claim 1 is critical to the charge retention performance of the carrier, and represents an unexpected result. However, only a single comparative example is cited as evidence of such criticality.
From MPEP 716.02(d):
II. DEMONSTRATING CRITICALITY OF A CLAIMED RANGE
To establish unexpected results over a claimed range, applicants should compare a sufficient number of tests both inside and outside the claimed range to show the criticality of the claimed range. In re Hill, 284 F.2d 955, 128 USPQ 197 (CCPA 1960).
Where only a single example possessing a particle size of the resin fine particles outside the claimed range is presented, and other variables are not probed alongside such a particle size, the criticality of that variable to the carrier performance is not reliably established. In addition, that comparative example is also the only example to possess a value of D/T outside the claimed range. Therefore, it is not clear whether the charge retention property of the carrier is dependent solely on the size of the resin particles contained in the coating layer, solely on the ratio D/T, or a combination of the two.
Further, as mentioned in the rejections below citing Shibuya et al, Shibuya teaches a requirement for stability of charging properties, even in the face of variable temperature or humidity, impacts, or abrasions over time. This requirement is essentially the same as the “charge retention ability” of the instant application, making such a result not unexpected in view of Shibuya.
For these reasons, the rejections below are not withdrawn.
Claim Rejections - 35 USC § 102
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claims 1, 2, and 8 - 14 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Watanabe et al (JP 2021-051216) (machine translation referred to henceforth).
Watanabe discloses an image developing carrier, a developer, a process cartridge, and an image forming apparatus ([0001]). The carrier comprises a core material and a coating layer covering the core material, which includes at least nitrogen-containing resin particles and inorganic oxide particles ([0021]).
The inorganic oxide particles are preferably silica particles ([0046]), which have preferably been hydrophobized by a hydrophobizing agent ([0047]). The hydrophobizing agent may be a silane coupling agent, and Watanabe gives hexamethyldisilazane (HMDS) as one example ([0048]). Treatment of silica particles with HMDS would render them nitrogen-containing silica particles. Watanabe teaches that the content of the hydrophobized silica particles is preferably 15 – 50% by mass with respect to the whole coating layer ([0049]), lying inside the range stated in Claim 1.
Watanabe that the nitrogen-containing resin fine particles preferably contain melamine resin particles ([0052]), and that the volume-average particle diameter of the nitrogen-containing resin particles is preferably 100 – 800 nm ([0055]), encompassing the range stated in Claim 1. Watanabe teaches that the content of nitrogen-containing resin particles in the resin coating layer is preferably 15 – 55% by mass relative to the content of the inorganic oxide (nitrogen-containing silica) particles ([0054]), which represents a ratio P/S in the same range as described in Claim 1.
As mentioned above, the inorganic particles of Watanabe, which are preferably silica, may be hydrophobized with HMDS, a nitrogen-containing silane coupling agent, reading on Claim 2.
Watanabe teaches that the resin coating layer of the carrier comprises a binder resin ([0040]), which preferably contains an alicyclic (meth)acrylic resin ([0041]), reading on Claim 8. Cyclohexyl (meth)acrylate is given as an example monomer which may be a polymerization component of the binder resin ([0042]), reading on Claim 9.
As discussed above, Watanabe teaches a preferred content for the hydrophobized silica particles of 15 – 50% by mass with respect to the whole coating layer, lying inside the range stated in Claim 10.
As discussed above, Watanabe teaches a preferred content for the nitrogen-containing resin particles of 15 – 55% by mass relative to the content of hydrophobized silica particles in the coating layer, representing a value of P/S of 0.15 – 0.55, encompassing the range stated in Claim 11.
Watanabe discloses a developer which contains a toner and the carrier as described above ([0079] – [0080]), reading on Claim 12.
Watanabe discloses a process cartridge which is detachably attached to an image forming apparatus, which accommodates the developer as described above and develops an electrostatic image on the surface of an image carrier ([0119]), reading on Claim 13.
Watanabe discloses an image forming apparatus comprising: an image carrier (the same as an image holding member); a charging means; an electrostatic image forming means; a developing means (the same as a developing device) which contains the developer as described above; a transfer means; and a fixing means ([0101]), reading on Claim 14.
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, 3, and 4 are rejected under 35 U.S.C. 103 as being unpatentable over Watanabe et al (JP 2021-051216) in view of Shibuya et al (JP 2001-051454) (machine translation referred to henceforth).
The above discussion of Watanabe is incorporated herein.
Shibuya teaches a carrier for an electrophotographic developer ([0001]). Shibuya teaches the importance of the carrier retaining its charging properties over time, even under varied temperature and humidity, mechanical impact, or abrasion ([0003]), which is addressed by Shibuya’s disclosure ([0016], [0017]). The carrier comprises core particles and a resin coating layer, which further comprises at least two types of nitrogen-containing particles ([0018]). Shibuya teaches that having nitrogen-containing particles dispersed in the coating layer on the core material of the carrier allows control over the charging of toner particles and long-term stability of charging activity ([0017]).
One of the nitrogen-containing particles described by Shibuya is a fine particle that has been surface-treated with a nitrogen-containing substance ([0029]). Shibuya teaches that these are preferable because the amount of nitrogen presented on the surface of the treated particles can be well controlled ([0029]). Shibuya gives silica particles as an example of the fine particles ([0030]). Shibuya teaches that silane coupling agents having a nitrogen-containing functional group are a suitable class of surface treatment agents for use with inorganic oxide particles (such as silica), since inorganic oxide particles have active hydroxyl groups on their surfaces which can react with hydrolysable silanol groups, keeping the treatment agent from coming off the surface of the particles ([0032]). Shibuya lists amines, amides, imines, and imides as examples of nitrogen-containing functional groups, and lists dialkoxy and trialkoxysilyl groups as examples of hydrolysable silanol groups ([0033]). Several examples of such bifunctional compounds are given, including 3-aminopropy(triethoxy)silane ([0034]), the same silane coupling agent used in the instant application.
In preparing the carrier of Watanabe, one of ordinary skill in the art would have been motivated to improve the control over and the longevity of the charging characteristics of the carrier by surface-treating the silica particles of the resin coating layer with a coupling agent of the aminoalkyl(alkoxy)silane class as taught by Shibuya. 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 carrier of Watanabe having silica particles treated with a silane coupling agent having both an amino group and a hydrolysable alkoxysilanol group, resulting in a carrier described by Claim 1 and by Claim 3.
Watanabe teaches that the silica particles preferably have a volume-average particle diameter of 5 – 50 nm ([0050]), encompassing the range stated in Claim 4.
Claims 5 – 7 are rejected under 35 U.S.C. 103 as being unpatentable over Watanabe et al (JP 2021-051216) in view of Anno et al (US PGP 2021/0088924).
The above discussion of Watanabe is incorporated herein.
Watanabe teaches that the volume-average particle diameter of the nitrogen-containing resin particles is preferably 100 – 800 nm ([0055]). Watanabe does not appear to teach a preferred thickness of the resin coating layer of the carrier.
Anno teaches a carrier for an electrophotographic developer, which includes at least a core material and a resin coating layer (Abstract). The resin coating layer is a resin layer covering the core, which also comprises inorganic particles ([0062] – [0063]). The resin of the resin coating layer may contain an alicyclic (meth)acrylic resin ([0068]), which preferably contains at least methyl (meth)acrylate and cyclohexyl (meth)acrylate ([0070]). The inorganic particles are preferably silica ([0074]), and Anno teaches that the silica particles are preferably hydrophobized by treatment with a silane coupling agent, which is preferably HMDS ([0075] – [0079]).
Anno teaches that the thickness of the resin coating layer is preferably 0.1 – 10 µm ([0088]). In preparing the carrier of Watanabe, but not being taught a preferred thickness of the resin coating layer, a practitioner of ordinary skill in the art would have looked to the prior art for guidance as to a workable thickness for the resin coating layer of a carrier which comprises hydrophobized silica particles. In adopting the range of thickness for the resin coating layer taught by Anno, the ratio D/T (where D is the volume-average diameter of the nitrogen-containing resin particles, and T is the thickness of the resin coating layer of the carrier) of the resulting carrier would thus lie in the range 0.01 – 8.
0.1
µ
m
(
D
)
10
µ
m
(
T
)
=
0.01
0.8
µ
m
(
D
)
0.1
µ
m
(
T
)
=
8.0
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 carrier of Watanabe having the resin coating layer thickness taught by Anno, which has a ratio D/T overlapping the range stated in Claim 5.
Watanabe teaches that the content of the nitrogen-containing resin particles is preferably 5 – 20% by mass with respect to the whole coating layer ([0053]), overlapping the range stated in Claim 6.
As mentioned above, Watanabe teaches that the volume-average particle diameter of the nitrogen-containing resin particles is preferably 100 – 800 nm ([0055]), encompassing the range stated in Claim 7.
Conclusion
THIS ACTION IS MADE FINAL. Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
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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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Jonathan Johnson can be reached at 571-272-1177. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/GRANT STEVEN SEILER/Examiner, Art Unit 1734
/PETER L VAJDA/Primary Examiner, Art Unit 1737
02/24/2026