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
Claim 1 is amended for formatting. Claim 11 is amended to specify the limitation of a geometric standard deviation by volume of a diameter of the carrier particles, thereby overcoming the rejection under 35 U.S.C. §112(b) in the prior office action. No new subject matter has been added.
Response to Arguments
Applicant's arguments filed 2025-11-24 have been fully considered but they are not persuasive.
Applicant argues, in essence, that because the references cited in the rejection of Claim 1 under 35 U.S.C. §103 do not teach the concentration of inorganic particles specifically in a region of 300 nm from either surface of a resin coating layer, that they fail to render the claim obvious. However, as stated in the prior office action, that rejection relies on an argument of inherency, and not on an explicit teaching of a concentration or ratio of concentrations of inorganic particles within a specified region of the coating layer.
Applicant further argues that the carrier of Sasaki having a resin coating layer prepared by the method taught by Takabayashi would not necessarily possess a value of M1/M2 in the range stated in Claim 1, and only may possess such a value. However, as stated in the instant application (Specification, pages 11 and 28), spray drying is a mode of forming the resin coating layer which allows the concentration of inorganic particles to be even throughout the coating layer, leading the value of the ratio M1/M2 to be near 1.0. Therefore, the carrier of Sasaki having a resin coating layer applied by the method taught by Takabayashi, that method being spray drying, would necessarily possess a value of the ratio M1/M2 near 1.0, as stated in the rejection in the prior office action.
Applicant also argues that there would not have been motivation for one of ordinary skill in the art to combine the teachings of Takabayashi with those of Sasaki, since there does not appear to be reason to believe that Sasaki’s method of forming the resin coating layer leads to non-uniformity of the coating resin. If it is assumed, arguendo, that the coating resin of Sasaki has a high degree of uniformity, and is formed by a spray drying method, then the carrier of Sasaki would necessarily possess a value of the ratio M1/M2 near 1.0 and satisfying Claim 1, even in the absence of Takabayashi’s teachings.
In addition, the motivation to combine references does not need to rely on the statement of a problem by the primary reference, and the teaching of a solution to that problem by a secondary reference. A practitioner of ordinary skill, being aware of Takabayashi’s teachings, would have understood the problems posed by non-uniformity of the resin coating layer on the carrier particles, and also that uniformity of the resin coating layer could be achieved by using the spray drying method (see updated rejection below, and Takabayashi [0028] – [0030], [0035] – [0037]). This represents sufficient motivation to apply the teachings of Takabayashi to the preparation of the carrier particles of Sasaki. This rationale also overcomes Applicant’s argument that there would be no motivation to combine the teachings of Takabayashi with those of Sasaki given the discussion of shear force. Finally, Applicant’s argument regarding a discussion by Takabayashi of non-uniform dispersion of carbon black in the coating layer does not overcome the necessary inherency of evenly concentrated inorganic fine particles throughout the resin coating layer of the carrier particles of Sasaki having the coating layer applied by the method taught by Takabayashi.
For these reasons, the rejections of Claims 1, 2, 4 – 11, 13, 14, and 16 under 35 U.S.C. §103, and of Claim 3 under 35 U.S.C. §103, are not withdrawn.
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, 2, 4 – 11, 13, 14, and 16 are rejected under 35 U.S.C. 103 as being unpatentable over Sasaki et al (US PGP 2021/0271180) in view of Takabayashi et al (US PGP 2020/0103778).
Sasaki teaches an electrostatic image developing carrier which includes magnetic particles and a resin layer coating the magnetic particles (Abstract). The magnetic particles are preferably ferrite particles ([0084]), and preferably have a volume-average particle diameter of 30 – 60 µm ([0085]). Sasaki gives a preferred thickness of the resin coating layer of 0.6 – 1.4 µm ([0074]), and teaches that the average thickness of the coating layer may be controlled by adjusting the amount of resin used ([0076]). Sasaki teaches that the exposed area of the magnetic particle cores is 0.1 – 4% of the surface area of the carrier particles ([0054]). The resin layer covering the magnetic particles also contains inorganic particles ([0053]). Sasaki teaches that the resin layer coating the magnetic particles may be formed by a wet method or a dry method ([0101]), and gives as an example of a wet method a fluidized bed method of spraying a resin layer-forming resin liquid onto the surface of magnetic particles fluidized in a fluidized bed ([0102]). Sasaki describes the resin layer forming liquid as being prepared by dissolving or dispersing the resin layer components in a solvent, such as toluene ([0103]). Sasaki does not appear to disclose a preparative example in which the carrier bearing a resin coating is prepared by spraying a resin layer-forming liquid onto magnetic particles in a fluidized bed.
Takabayashi teaches and electrophotographic carrier comprising core particles having a coating layer (Abstract). The carrier particles of Takabayashi preferably have a volume-average particle diameter of 25 - 38 µm ([0054]), and the thickness of the coating layer is preferably 0.5 µm or more ([0065]). The coating layer also contains inorganic particles ([0008]). Takabayashi gives a discussion of the disadvantages arising from non-uniformity of the coating layer disposed on the surface of the magnetic particles ([0035] – [0036]), and states a preference that the constituent element variation should lie within ±5%, corresponding to a highly uniform film ([0037]). Takabayashi describes a method of spray coating the magnetic particles with a resin liquid in a fluidized bed, and elaborates on how this process can be carried out so as to achieve a uniform coating layer ([0028] – [0030]). In preparative examples, Takabayashi describes a process of spraying a resin liquid onto magnetic particles having a volume-average particle diameter of 35 µm using a SPIRA COTA fluidized bed apparatus ([0099]). The addition rate of coating resin was 30 g/min, and the atmosphere inside the apparatus was 60°C ([0099]). The process described by Takabayashi is substantially identical to that described in the instant application for Example 1 (Specification, pages 53 – 54). That is, a coating liquid is sprayed onto ferrite particles of the same volume-average diameter (35 µm), at the same rate (30 g/min), in the same apparatus (SPIRA COTA fluidized bed coater), at a similar temperature (70°C versus 60°C).
In preparing the carrier taught by Sasaki, where a method of spray coating the magnetic particles in a fluidized bed is mentioned but not detailed, one of ordinary skill in the art would have been motivated to adopt the method taught by Takabayashi so as to ensure uniform coating of the magnetic particles. As described in the instant application, the spray drying method of forming the coating layer results in a cavity between the core magnetic particle and the coating layer having a width of 50 nm or more ([0013]). In addition, all preparative examples disclosed in the instant application that were prepared by such a method possess a value for the ratio M1/M2 in the range of 0.8 – 1.2 (Specification, page 62, Table 1). Thus, the carrier particles of Sasaki prepared by the method taught by Takabayashi would inherently also possess a value for M1/M2 in that range. 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 particles of Sasaki using the method taught by Takabayashi, resulting in a carrier described by Claim 1.
Sasaki teaches that the resin coating layer may contain conductive particles, such as carbon black ([0100]), satisfying Claim 2.
Sasaki teaches that the content of the inorganic particles in the resin coating layer is preferably 10 – 60% by mass, encompassing the ranges stated in Claim 4 and Claim 5.
As discussed above, Sasaki teaches a preferred thickness of the resin coating layer of 0.6 – 1.4 µm ([0074]), which encompasses the reported values for the average thickness of the coating layer of preparative examples 1 – 6 of the instant application (Specification, page 62, Table 1). All of those examples also have values for the ratio of the width of the cavity to the average thickness of the coating layer lying in the range of 0.09 – 0.5. The carrier particles of Sasaki produced by the method taught by Takabayashi, which is substantially identical to the method of producing the instant preparative examples just mentioned, would inherently have cavities of similar width to those preparative examples. Where the average thickness of the resin coating layer of such carrier particles is also substantially the same as in those examples, the carrier particles of Sasaki produced by the method taught by Takabayashi would inherently possess a value for the ratio of the width of the cavity to the thickness of the resin coating layer lying in the ranges stated in Claim 6 and Claim 7.
Preparative examples 1 – 5 of the instant application all possess a value for the average width of the cavity lying in the range of 120 – 230 nm (Specification, page 62, Table 1). The carrier particles of Sasaki produced by the method of Takabayashi, being produced by a substantially identical method, would inherently possess a value for the average width of the cavity lying in the range stated in Claim 8.
Preparative examples 1 – 7 of the instant application all possess a value for the percentage area of the cavity versus the whole carrier particle lying in the range of 0.9 – 3.8% (Specification, page 62, Table 1). The carrier particles of Sasaki produced by the method of Takabayashi, being produced by a substantially identical method, would inherently possess a value for the percentage area of the cavity versus the whole carrier particle lying in the range stated in Claim 9.
Preparative examples 1 – 7 of the instant application all possess a value for SF1 of the carrier particle in the range of 115 - 130 (Specification, page 62, Table 1). The carrier particles of Sasaki produced by the method of Takabayashi, being produced by a substantially identical method, would inherently possess a value for SF1 of the carrier particle lying in the range stated in Claim 10.
Preparative examples 1 – 7 of the instant application all possess a value for the geometric standard deviation by volume lying in the range of 1.18 – 1.28 (Specification, page 62, Table 1). The carrier particles of Sasaki produced by the method of Takabayashi, being produced by a substantially identical method, would inherently possess a value for the geometric standard deviation by volume lying in the range stated in Claim 11.
Sasaki teaches a two-component developer comprising the carrier and a toner ([0115]), satisfying Claim 13.
Sasaki discloses a process cartridge which can be attached to and detached from an image forming apparatus ([0238]). The process cartridge includes a developing unit which stores the developer which comprises the carrier, and which develops an electrostatic charge image formed on the surface of an image carrier, satisfying Claim 14.
Sasaki discloses an image forming apparatus which includes: an image carrier; a charging unit; an electrostatic charge image forming unit (analogous to an exposure component); a developing unit which uses the developer which comprises the carrier; a transfer unit; and a fixing unit, satisfying Claim 16.
Claim 3 is rejected under 35 U.S.C. 103 as being unpatentable over Sasaki et al (US PGP 2021/0271180) in view of Takabayashi et al (US PGP 2020/0103778), further in view of Onozaki et al (US PGP 2020/0166862).
The above discussion of Sasaki et al and Takabayashi et al is incorporated herein.
Onozaki teaches an electrophotographic carrier comprising a magnetic core particle and a resin coating layer formed on the surface of the core (Abstract). Onozaki teaches that a particle or material having charge control properties may be included in the resin coating layer ([0192]), which serves the purpose of adjusting the triboelectric charge quantity of the carrier ([0196]). Particles of various resins, including polymethyl methacrylate resin particles and melamine resin particles, are given as examples ([0195]).
In preparing the carrier of Sasaki by the method taught by Takabayashi, one of ordinary skill in the art would have been motivated to modulate the triboelectric charge amount of the carrier particles by incorporating the resin particles into the coating layer as taught by Onozaki. 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 Sasaki by the method taught by Takabayashi, and incorporating the resin particles of Onozaki, resulting in an electrophotographic carrier described by Claim 3.
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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/GRANT STEVEN SEILER/ Examiner, Art Unit 1734
/PETER L VAJDA/ Primary Examiner, Art Unit 1737 01/15/2026