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 Amendment
Claims 1 and 3 – 5 have been amended to rearrange previously recited limitations, and to add several limitations. Claim 2 is canceled. New Claims 10 – 16 have been added. No new subject matter has been added.
Response to Arguments
Applicant’s arguments, see Remarks, filed 2026-06-22, with respect to the rejections of claims 1 and 2 - 9 under 35 U.S.C. §103 have been fully considered and are persuasive. Therefore, the rejection has been withdrawn. However, upon further consideration, a new ground of rejection is made in view of Yamashita et al, Tsurumi et al, Chiba et al, and Nishikawa et al (detailed below).
Regarding amended Claim 4, Applicant asserts in the remarks that the diameter of the second silica particles is now constrained to a range of 32 – 70 nm. However, the most recent listing of claims reflects the original range of 32 – 145 nm for the second silica particles in Claim 4. For the purpose of compact prosecution, the references cited in the updated rejection below cover both of the ranges just mentioned.
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 – 16 are rejected under 35 U.S.C. 103 as being unpatentable over Yamashita et al (JP 2003-280284; machine translation of which is referred to) in view of Tsurumi et al (US PGP 2019/0286000), further in view of Chiba et al (US PGP 2019/0212667), further in view of Nishikawa et al (US PGP 2016/0041483).
Yamashita teaches a carrier for a developer having a coating layer formed on the surface of a carrier core particle, wherein the coating layer comprises at least a resin and particles ([0015]). The resin of the coating layer may be silicone ([0021]). Yamashita teaches that the particles in the coating layer may be barium titanate, and teaches that the particles preferably have a number-average diameter of 10 – 1,000 nm ([0024]). Yamashita discloses two different preparative examples having barium titanate particles included in the coating layer of the carrier particles, and in both cases the number-average diameter of the barium titanate particles is 300 nm ([0055], [0056]). Yamashita teaches a two-component developer comprising a toner and the carrier previously described ([0125] – [0127]), but does not provide further details regarding the toner. Yamashita does not appear to teach strontium titanate particles attached to the surfaces of the carrier particles.
Tsurumi teaches a carrier for an electrostatic image developer which includes carrier core particles having a resin coating layer, and strontium titanate particles (Abstract). The coating layer may include a silicone resin ([0050]). The strontium titanate particles comprised in the carrier help to prevent fogging even after repeated formation of high-density images ([0028], [0031]). Tsurumi teaches a preferred average particle diameter of the strontium titanate particles of 10 – 100 nm ([0064]).
Chiba teaches a toner comprising an external additive A, which is silica particles, and an external additive B, which is silicone resin particles (Abstract). The silica particles preferably have a number-average particle diameter of 5 – 30 nm, and the silicone resin particles preferably have a number-average particle diameter of 50 – 1,000 nm ([0012]). Chiba teaches that the silicone resin particles may be surface-treated with a hydrophobizing agent, which may be selected from those used to treat the silica particles ([0044]). Among those hydrophobizing agents listed is a silicone oil ([0024]), which may be dimethyl polysiloxane (dimethyl silicone oil) or methyl hydrogen polysiloxane (methyl hydrogen silicone oil) ([0029]). In addition to the external additives mentioned, Chiba teaches that an external additive C may be used, which is silica particles having a number-average particle diameter of 31 – 200 nm ([0013]). Chiba does not appear to teach composite particles as an external additive.
Nishikawa teaches a toner having an organic-inorganic composite fine particle (Abstract). The organic-inorganic composite fine particle is externally added to the toner particle ([0024]), and since an inorganic fine particle is embedded in the surface of the resin particle, the composite particle does not readily roll, and stays uniformly dispersed ([0025]). Nishikawa teaches that this also allows other external additives to retain uniform dispersity ([0026]). The inorganic fine particle which is comprised in the composite particle may preferably be silica particles ([0041]). The diameter of these silica particles is preferably 10 – 70 nm ([0042]).
In preparing the carrier of Yamashita, one of ordinary skill in the art would have been motivated to suppress a fogging effect by incorporating the strontium titanate particles as taught by Tsurumi. In addition, where Yamashita does not detail the toner to be used alongside the carrier in a two-component developer, one of ordinary skill in the art would have been motivated to use the toner taught by Chiba. In preparing the toner of Chiba, one of ordinary skill in the art would have been motivated to suppress rolling of the externally added resin particles by embedding silica particles into the surfaces of the resin particles as taught by Nishikawa. 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 carrier of Yamashita, modified with the strontium titanate particles of Tsurumi; and the toner of Chiba, wherein the resin particles have embedded silica particles as taught by Nishikawa. Chiba’s external additive A (silica particles) read on the instant first silica particles, and Chiba’s external additive B (silicone resin particles) read on the instant resin particles included in the instant spacer particles, satisfying Claim 1.
The ranges mentioned above read on those for instant first silica particles; instant resin particles included in the instant spacer particles; instant strontium titanate particles; and instant barium titanate particles recited in Claim 3. In addition, these ranges allow the diameter of the spacer particles to be greater than that of the strontium titanate particles. Chiba teaches that the externally added silicone resin particles are preferably added in an amount of 0.1 – 1.0 parts by mass relative to 100 parts of toner particles ([0012]). Example toner particles disclosed in the instant application which have addition amounts of resin particles as the spacer particles lying in this range also possess values for the coverage ratio lying in the range stated in Claim 1 (Specification, Table 10). Therefore, the toner of Chiba would necessarily possess a value for the coverage ratio of the silicone resin particles (modified with the embedded silica particles of Nishikawa) lying in a range overlapping that stated in Claim 3.
Chiba’s external additive C, which is silica particles having a number-average diameter of 31 – 200 nm, reads on instant second silica particles included in the spacer particles, satisfying Claim 4.
The silicone oil surface treatment on the surface of Chiba’s silicone resin particles is analogous to the adhesive component of the instant composite particles. In addition, the silica particles embedded in the resin particles taught by Nishikawa are analogous to the instant third silica particles. Therefore, the external additive taught by Chiba and modified by Nishikawa is analogous to the instant composite particles included in the spacer particles, satisfying Claim 5.
Where the silica particles embedded in the resin particles taught by Nishikawa (analogous to instant third silica particles) may have a number-average diameter in a range overlapping that for the silica particles taught by Chiba (analogous to instant first silica particles), the two may have the same diameter. Further, it would have been obvious to a practitioner of ordinary skill in the art to use the same silica particles (including surface treatment) for both purposes, satisfying Claim 6.
The mentioned above for the diameters of the resin particles, strontium titanate particles, and silica particles allow a value of L to lie in a range reading on that stated in Claim 7, Claim 10, and Claim 11.
Yamashita teaches an image forming apparatus ([0035]), which comprises a developing device ([0040]). The developing device includes a developer accommodating member ([0040]), analogous to the accommodation section of Claim 8, Claim 12, and Claim 13; and a replenishing mechanism ([0040]), analogous to the replenishment section of Claim 9, Claim 14, and Claim 15.
The ranges mentioned above read on those for instant resin particles and instant third silica particles recited in Claim 16.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). 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.
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/GRANT STEVEN SEILER/Examiner, Art Unit 1734
/PETER L VAJDA/Primary Examiner, Art Unit 1737 07/13/2026
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