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 have been amended to more clearly define the chemical and structural features of the invention. Claims 2, 4 – 6 and 8 – 11 have been amended for clarity and formatting. New Claim 12 has been added. The Specification has been amended for clarity and formatting. No new subject matter has been added.
In light of the present amendments to Claims 1, 3, and 4, the rejection under 35 U.S.C. §112(b) made in the prior office action is withdrawn.
Response to Arguments
Before addressing Applicant’s arguments regarding the rejections laid out in the prior office action, the examiner appreciates Applicant’s help in pointing out the IDS document (one of two filed 2023-08-11) which was inadvertently overlooked and not considered in the non-final rejection.
Applicant's arguments, filed 2026-02-24, regarding the rejection under 35 U.S.C. §103 in the prior office action have been fully considered but they are not persuasive.
First, Applicant argues that the cited references do not teach a procedure of the first surface treatment of the externally added silica particles which would result in a value for Sn (a measure of the number of unmodified Si-OH groups at the silica particle surface) lying in the claimed range. This is because Hayashi allegedly does not teach a sufficiently high temperature and pressure in the first surface treatment, and Applicant provides a separate but similar preparative example, along with a reported value for Sn.
However, as also noted in the updated rejection below, Hayashi does teach a temperature during the first surface treatment (“coating treatment”, in Hayashi’s terminology) as high as 400°C ([0049] of machine translation), reaching above the required threshold of 300°C stated in Applicant’s remarks. Hayashi even discusses the same chemical modification of the surface of the silica particles by the first treatment agent, such that the coating layer would not be released when extracted with chloroform (as recited in instant Claim 1) due to “chemical adhesion” ([0049]). Hayashi further teaches that, in the first surface treatment, the whole amount of treatment agent added should become chemically attached to the surface of the silica particles, with none left unreacted as “free silicone oil” ([0054]). The amount of treatment agent used should be equal to or less than the maximum amount which could become chemically bonded to the surface of the silica particles ([0054]), implying a theoretical lower limit to the value of Sn achieved by Hayashi of 0.
While Hayashi does not appear to teach a preferred pressure inside the reaction vessel (“gauge pressure” as recited in the instant application) during the first surface treatment of the silica particles, Hayashi is still aimed at complete consumption of the first treatment agent, so the combination of reaction temperature, time, and pressure would be adjusted to achieve that outcome.
Applicant also argues that the claimed range of Sn is result-effective for the charging quantity and dripping evaluations, and therefore non-obvious over the prior art. However, instant silica fine particles 19 and 20, which each possess values for Sn outside the claimed range, also possess values for the ratio D1/D2 outside the range stated in Claim 3 (Specification, Table 1-2). Notably, these are the only two preparative examples disclosed in the instant application which possess values for Sn outside the claimed range; there is no disclosed example having a value for Sn outside the claimed range, but having a value for the ratio D1/D2 inside the preferred range. Therefore, the criticality of the value of Sn cannot be disentangled from the influence of the ratio D1/D2, and a reliable relationship cannot be drawn between the value of Sn and performance in the charge stability and dripping evaluations.
Further, Hayashi’s disclosure is directed to surface-coated silica possessing stable charging under high-temperature and high-humidity environments ([0001]), which imparts these properties to the toner to which the treated silica is externally added ([0002], [0016], [0073]). Matsui’s disclosure is also aimed at a toner having stable charging properties and storage stability ([0050], [0114]), even under high-temperature and high-humidity environments ([0115]). Where the defect of “dripping” is attributable to loss of charge due to moisture absorption by the toner, as taught by the instant Specification ([0005]), the desirable property of suppression of dripping would be expected to flow from the charge stabilizing aims taught by Matsui and Hayashi.
For these reasons, the updated rejections below 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 – 11 are rejected under 35 U.S.C. 103 as being unpatentable over Matsui et al (US PGP 2011/0311910) in view of Hayashi et al (JP 2007-176747) (machine translation of which is referred to henceforth).
Matsui teaches a toner comprising toner particles, which in turn comprise a binder resin, a release agent, and an inorganic fine powder (Abstract). The binder resin may preferably be a styrene copolymer, such as a styrene-acrylate copolymer ([0085]). Matsui teaches that the toner particles may have a core-shell structure ([0114]), and that the shell is preferably amorphous ([0115]) polyester resin ([0118]). The shelling resin preferably has an acid value of 1 – 20 mg KOH/g ([0115]), so that when the toner is produced by suspension polymerization of the core resin in the presence of the shelling resin, the shelling resin is localized to the surfaces of the resultant toner particles ([0116]).
Matsui describes the production of toners by suspension polymerization of a styrene-acrylate resin in the presence of a polyester resin ([0281]), which is substantially the same method as that disclosed in the instant application. The polyester resin incorporated as the shelling resin is a copolymer of terephthalic acid and alkylene oxide adducts of BPA, having an acid value of 6 or 7 mg KOH/g ([0268], [0271]), substantially similar to the amorphous polyester resin disclosed in the instant application. Many of the example toners disclosed by Matsui in Table 5 (pages 22 – 23) incorporate release agent P2, which is HNP-51 (Table 2, page 19), the same as that used in the instant application. Thus, the base toner particles of Matsui, having substantially the same components and being produced in the same way, are essentially the same as those disclosed in the instant application.
Matsui teaches that the inorganic fine powder may be used as an external additive ([0184]). The inorganic fine powder preferably has a number-average particle diameter of 4 – 80 nm, and may be subjected to hydrophobic treatment. The externally added inorganic fine powder is preferably silica ([0186]). Matsui teaches that silicone oils and other hydrophobizing agents may be used, and that they may be used in combination of two or more different agents ([0188]). Matsui states a preference for silicone oils as at least one of the hydrophobizing agents to be used, and describes a two-stage method for treating the silica particles with two different hydrophobizing agents ([0189]). Among the silicone oils, dimethylsilicone oil is preferred ([0191]), and a spraying method of treatment is disclosed ([0192]). Matsui does not appear to teach treatment of silica particles with a cyclic siloxane compound.
Hayashi teaches silica treated with two or more types of silicone oil ([0001]). The treated silica is useful as an external additive for electrophotographic toners, and exhibits excellent environmental stability, good control of the charge level, and reduced agglomeration of the particles. Hayashi describes a method of producing treated silica by coating the base particle with a plurality of different agents in sequence ([0019]). The combination of octamethylcyclotetrasiloxane and dimethylsilicone oil is pointed out as advantageous ([0021]). In describing the silica base particles used, Hayashi teaches a preferable specific surface area of 10 – 400 m2/g and a preferred primary particle diameter of 5 – 1,000 nm ([0027]). In addition, multiple types of silica particles may be mixed and used together as the base material for hydrophobic treatment.
Hayashi teaches that octamethylcyclotetrasiloxane is a preferred silicone oil that is not included in the “free” silicone oil ([0042]). This means that octamethylcyclotetrasiloxane is preferably the first agent used to treat the silica base particles. Dimethylsilicone oil is preferably included in the “free” silicone oil, which is to say that it is the second agent used in the treatment. The combination of octamethylcyclotetrasiloxane as not included in the “free” silicone oil, and dimethylsilicone oil as being included in the “free” silicone oil is pointed out as a preferred embodiment.
Hayashi describes the method of surface treatment, including mixing the first silicone oil with the silica base material and heating the mixture, thus chemically bonding the first treatment agent to the surface of the silica particles, immobilizing the layer ([0047]). The temperature at which the coating treatments is carried out is preferably 180 - 400°C ([0049]). The entire amount of first treatment agent used should become bonded to the surface of the silica particles, such that none is left as “free silicone oil” ([0054]). The amount of treatment agent used should thus be equal to or less than the maximum amount which could become bonded to the surface of the silica particles ([0054]). Where the maximum amount of first silicone oil treatment agent is used, substantially all of the hydroxyl groups at the surface of the silica particle would be modified, corresponding to a value for Sn approaching 0.
Hayashi teaches that a preferable method of mixing a low-boiling point silicone oil treatment agent, like octamethylcyclotetrasiloxane, with the silica base particles is to heat the treatment agent and spray a vapor from a nozzle onto the silica ([0051]). The time of heating required for surface treatment may be from 30 minutes to 2 hours ([0052]).
A second treatment is then carried out with the second, different silicone oil treatment agent. In one preparative example, the dimethylsilicone oil is KF-96-50CS ([0097]), the same as that disclosed for several examples in the instant application.
Hayashi teaches that the addition amount of the treated silica as an external additive to toner particles is usually 0.05 – 5% by mass relative to the toner particles ([0062]). The silica particles may be used alongside other external additives, including titania particles ([0063]).
In preparing the toner of Matsui, one of ordinary skill in the art would have been motivated to incorporate the hydrophobized silica particles having excellent environmental stability, charge control, and agglomeration resistance, taught by Hayashi. Where the toner particles of Matsui are essentially the same as those disclosed in the instant application, polyester resin would necessarily be present on the surface of the toner particle. Further, the silica particles of Hayashi, being treated by a substantially identical method with the same silicone oil treatment agents as Silica fine particle No. 1 disclosed in the instant application (Specification, [0112], Table 1-1), would necessarily possess similar physical properties to the instant particles. That is, the silica particles of Hayashi would exhibit fragment ions corresponding to formula (1) in TOF-MS; possess a value for Sn of roughly 0.15; possess a value for (D/S)/B before washing of roughly 1.5 x 10-3; possess a value for (D/S)/B after washing of roughly 9.7 x 10-4; and possess a value of (D1/D) of roughly 0.20. 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 toner of Matsui incorporating the hydrophobized silica particles of Hayashi as an external additive, resulting in a toner described by Claim 1.
Where the toner particles of Matsui are essentially the same as those disclosed in the instant application, the toner described above would inherently possess a value for Sp of roughly 90%, satisfying the inequality stated in Claim 2.
The silica particles of Hayashi, being treated by a substantially identical method with the same silicone oil treatment agents as Silica fine particle No. 1 disclosed in the instant application, would exhibit similar physical properties to the instant particles. That is, the silica particles of Hayashi would inherently possess a value for (D1/D2) of roughly 0.38, lying in the range stated in Claim 3.
Similarly, the silica particles of Hayashi would inherently possess a value of (D2/D) of roughly 0.53, satisfying the range stated in Claim 4.
The toner of Matsui incorporating the hydrophobized silica particles of Hayashi, being substantially similar to example Toner No. 1 of the instant application, would inherently possess a value for Ssi of roughly 63%, satisfying the inequality stated in Claim 5.
Similarly, the toner of Matsui incorporating the hydrophobized silica particles of Hayashi would inherently possess a value for (Sp/Ssi) of roughly 1.43, lying in the range stated in Claim 6.
As mentioned above, Hayashi teaches that the addition amount of the treated silica as an external additive to toner particles is usually 0.05 – 5% by mass relative to the toner particles ([0062]), encompassing the range stated in Claim 7.
As mentioned above, Matsui teaches a preferred particle diameter of the external additive of 4 – 80 nm ([0184]). As also mentioned above, Hayashi teaches a preferred primary particle diameter of the silica particles of 5 – 1,000 nm ([0027]). Both of these encompass the range stated in Claim 8.
As mentioned above, Hayashi exemplifies the use of dimethylsilicone oil KF-96-50CS, reading on formula (3) of Claim 9.
As mentioned above, Matsui teaches a preferred acid value for the shelling resin (amorphous polyester) of 1 – 20 mg KOH/g ([0115]), overlapping the range for Av stated in Claim 10. Where the toner of Matsui incorporating the hydrophobized silica particles of Hayashi would inherently possess similar values for Sp and Sn (discussed above) to those reported for instant example Toner No. 1, such a toner would also inherently possess a value for (Av/Sp)/Sn of roughly 0.74, lying in the range stated in Claim 10.
As mentioned above, Hayashi points out a preferred embodiment in which the silica particles are first treated with octamethylcyclotetrasiloxane (a cyclic siloxane), and subsequently treated with dimethylsilicone oil ([0042]), satisfying Claim 11.
Claim 12 is rejected under 35 U.S.C. 103 as being unpatentable over Matsui et al (US PGP 2011/0311910) in view of Hayashi et al (JP 2007-176747), further in view of Kawakami et al (US Patent 6,287,739).
The above discussions of Matsui and Hayashi are incorporated herein. Neither Matsui nor Hayashi appears to teach small- and large-diameter silica particles blended in a mass ratio of 5:1 to 20:1.
Kawakami teaches a toner comprising toner particles and an external additive. The external additive comprises small-diameter silica particles (A) and large-diameter silica particles (B) (Abstract). The small-diameter silica particles preferably have a particle diameter of 5 – 20 nm, lying inside the range stated for silica fine particle A in Claim 12, and are preferably surface-treated with a silane (col. 5, lines 22 – 24). These particles impart charging performance and fluidity to the toner (col. 5, lines 24 – 26). The large-diameter silica particles preferably have a particle diameter of 30 – 150 nm, overlapping the range stated for silica fine particle B in Claim 12, and are preferably surface-treated with a silicone oil (col. 5, lines 62 – 64). The particles impart the spacer effect to the toner (col. 5, line 65 – col. 6, line 3; col. 1, lines 41 - 65). The small- and large-diameter silica particles are preferably added to the toner particles in a mass ratio in the range of 1:0.1 – 1:0.65 (col. 8, lines 9 – 16), preserving both the spacer effect and fluidity (col. 8, lines 19 – 24). These ratios convert to a range of 1.54:1 – 10:1, reading on the mass-based content ratio stated in Claim 12.
In preparing the toner of Matsui having the surface treated silica particles of Hayashi, one of ordinary skill in the art would have been motivated to improve the fluidity of the toner and impart a spacer effect by pairing small-diameter silica particles with large-diameter silica particles as the base particles of the external additive as taught by Kawakami. 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 toner of Matsui externally added with the silica particles of Hayashi, wherein the particle diameters and content ratios of the externally added silica particles are controlled as taught by Kawakami, resulting in a toner satisfying Claim 12.
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 05/12/2026
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