DETAILED ACTION
Response to Arguments
Applicant’s arguments, see the Response, filed 12/18/2025, with respect to the rejection of claims 1-3, 6-10 and 12-13 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 Therefore, the rejection has been withdrawn.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 below.
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.
Claims 1-3, 6-10 and 12-14 are rejected under 35 U.S.C. 103 as being unpatentable over Kojima (US PGP 2013-0244156) in view of Daichi (Japanese Patent Application Publication No. 2021-039284) and further in view of Floess (US PGP 2007-0264502).
Kojima teaches a toner, including base particles and an external additive (Abstract). Kojima does not teach the specific formula of Bt – 0.025 x Ct, wherein Bt is a BET specific surface area of the toner particles, including the irregularities of both the surface of the base particles and the surface of the external additive (Applicant Specification [0139]), and Ct is a percent coverage by the external additive. Applicant’s specification teaches that this formula represents the BET specific surface area of the toner base particles ([0191] line 1-3), and is used as an indicator of surface smoothness of the base particles ([0140]). Kojima directly teaches a BET specific surface area of the toner base particles of 2.5 to 5.0 m2/g ([0048]) rather than the value being represented by a formula. Exemplary toners 7-12, 24-29 and 41-46 possess BET specific surface areas of 2.5 m2/g (Table 2). Controlling this value is important for ensuring the desired coverage of the external additives and how well they stay affixed to the toner particles (Kojima [0048], Applicant [0138]). Based on the base particles having similar smoothness and amounts of external additives added (Kojima, 4.6 parts additives to 100 parts toner base particles [0273]; Applicant, 4.5 parts additives to 100 parts toner base particles [0327]), the coverage percentage of the external additives would also be similar. Kojima teaches that the toner average circularity is 0.97-1.0 ([0173]). The external additive may be silica that is surface treated to increase hydrophobicity ([0121]).
The toner may be used as a two-component developer ([0002]) and the toner is contained in the developing device ([0225]). Kojima teaches an image forming apparatus comprising a photoreceptor (image bearing member), a charger, an exposure device, a developing device, a transferring unit, and a fixing unit ([0217]).
Kojima is silent regarding a THF insoluble component having a glass transition temperature obtained from a differential scanning calorimetry curve at a second warming. However, Daichi teaches a toner having a THF insoluble component having a glass transition temperature, Tg2nd, of -45°C to 5°C (Abstract). A Tg2nd of lower than -45°C lowers the storage stability of the toner, and a Tg2nd of higher than 5°C reduces the low-temperature fixability, and does not suppress peeling of the image ([0016]). Daichi also teaches that the toner circularity should be 0.985 or less in order to improve the cleaning property of the toner and suppress image peeling ([0157] line 6-9). Daichi teaches an external additive that may be silica ([0140]) that is hydrophobized with a silane coupling agent such as methyltrimethoxysilane and methyltriethoxysilane ([0143]), with have an alkyl group with less than 4 carbon atoms. Although Kojima and Daichi employ different methods of solving the problem of low-temperature fixability, a capsule structured toner for Kojima ([0010-11]), and a polyester containing a THF-insoluble component for Daichi ([0008],[0012]), neither teach away from the other methods of addressing the problem. A person of ordinary skill in the art may choose to combine solutions to the same problem to try and produce a toner with improved results. Therefore, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to have modified the toner of Kojima to have included a THF-insoluble component having a Tg2nd of -45°C to 5°C and a circularity of not more that 0.985 in order to have produced a toner with good storage stability, low temperature fixability, good cleaning properties, and that does not peel.
Kojima and Daichi teach an external additive of silica with a hydrophobic surface treatment (Kojima [0121], Daichi [0140], [0143]), but both Kojima and Daichi are silent regarding also coating the silica with a metal oxide or hydroxide. Floess teaches a composite metal oxide particle for use with toner that comprises a first metal oxide and a coating consisting of a second metal oxide (Abstract). The first and second metal oxides are selected from the group consisting of silica, alumina, titania, tin oxide, zinc oxide, and cerium oxide ([0017] line 5-7). From this short list of oxides, a particle comprising a core of silica with a coating of zinc oxide would be easily achieved. When the coating consists of a second metal oxide different from the first metal oxide, the composite metal oxide particles advantageously combines the properties of the individual metal oxides ([0019]). The primary particle diameter of the core of the external additive is 5 to 400 nm ([0021]), and the average particle diameter of the composite particle is substantially similar to the diameter of the core ([0028]). The particles may be surface treated with a hydrophobic treating agent such as a silane treating agent ([0031]). The silane treating agent is represented by the general formula (R5)nSiX4-n, wherein R5 may be an alkyl group having 1 to 4 carbon atoms ([0034]). Therefore, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to have modified the external additive to be a composite metal oxide in order to produce a particle having the benefits of both oxides.
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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/J.K./Examiner, Art Unit 1734
/PETER L VAJDA/Primary Examiner, Art Unit 1737 01/12/2026