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 .
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 3 December 2025 has been entered.
Amendments
Applicant’s amendment to claim 1 and the cancellation of claim 2 are acknowledged and the amended claims have considered for this action.
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.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
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 3-4 are rejected under 35 U.S.C. 103 as being unpatentable over Nakanaga et al. (Japanese Patent Application Publication JP2003165718A, hereinafter “Nakanaga”) in view of Mihashi et al. (JP 2005022915 A). The previously provided English machine translations for Nakanaga (JP2003165718) and Mihashi (JP2005022915) are referenced below.
Regarding claim 1, Nakanaga teaches the preparation of non-porous spherical silica with a specific surface area of ~10 m2/g (paragraphs 20 and 28 and Table 1), which falls just outside the claimed ranges of 1 to 6.2 m2/g or 11.4 to 30 m2/g. However, Nakanaga also teaches that particles with lower, or even somewhat higher surfaces areas would also be acceptable variants, as long as they satisfy the condition S x d<5 ([0029]), which would be true of Nakanaga’s 0.3 μm particles with surface areas as high as 16 m2/g. It is also noted that Mihashi teaches that silica particles with surface areas up to 30 m2/g maintain high flowability ([Overview]).
Nakanaga also teaches the drying of these particles at temperatures of 650 °C to 1100 °C for 2 hours (paragraph 21) and that samples so prepared have the FT IR spectrum provided as Fig. 8 (paragraph 29 and Figure 8; annotated version of Fig. 8 is included below). Close examination of the IR spectrum in Fig. 8 reveals that the ratio of the (baseline corrected) intensity in the region from 3660 cm-1 to 3680 cm-1 (B) to the intensity in the region of from 3735 cm-1 to 3755 cm-1 (A), calculated as the area under the curve (integrated intensity) in each region as described in the instant specification [0060], is approximately 0.96, which meets the instant limitation where the value of B/A is in the range of 0.2 to 3.0.
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Annotated version of Figure 8 from Nakanaga: a baseline has been approximated and vertical lines are indicated every 20 cm-1 in the region of 3600 cm-1 to 3800 cm-1. The area of the red boxes, labeled A and B in the inset, were calculated using Adobe Acrobat as 0.75 and 0.72, respectively, for an intensity ratio of 0.96.
Nakanaga does not explicitly teach the powder, when heated from 25°C up to 1000°C at a rate of 30°C/min, desorbing water molecules in amount of 0.01 mmol/g or less at 500°C to 1000°C, as required by the limitations of the instant claim.
However, the amount of water remaining on the particles, and therefore able to be desorbed using the recited heating profile, will be a function of the surface properties and the heating time and temperature. Because Nakanaga teaches that the particles are dehydrated by the calcination procedure employed in their method (paragraphs 2, 18 and 29), and because this procedure is substantially identical to that described in the instant specification (instant specification paragraph 19 and Table 2; Example 1 [900 °C and 2 h, surface area of 2.3 m2/g] and Example 11 [1000°C and 4 h, surface area of 11.4 m2/g], in particular), one of ordinary skill in the art would expect the products to have the same properties. Furthermore, because Nakanaga dehydrates their particles at 1100 °C for two hours to remove water, one would expect little water to be left for desorption in a subsequent heating cycle of only 16 min at lower temperatures (500 °C to 1000 °C at 30 °C/min).
It is acknowledged that the furnace used in Nakanaga is different from the furnace used in the method of the instant invention. However, in the absence of showings of criticality, so long as the silica particles are heated to at least 900 °C, as taught by Nakanaga, the apparatus in which they are heated would not be expected to impact the temperature achieved by the particles, and therefore the amount of water present in the spherical silica following heating.
It is noted that where the claimed and prior art products are identical or substantially identical in structure or composition, or are produced by identical or substantially identical processes, a prima facie case of either anticipation or obviousness has been established. In re Best, 562 F.2d 1252, 1255, 195 USPQ 430, 433 (CCPA 1977). MPEP 2112 .01(I). Furthermore, once a reference teaching a product appearing to be substantially identical is made the basis of a rejection, and the examiner presents evidence or reasoning tending to show inherency, the burden shifts to the applicant to show an unobvious difference. "[T]he PTO can require an applicant to prove that the prior art products do not necessarily or inherently possess the characteristics of [their] claimed product. Whether the rejection is based on inherency’ under 35 U.S.C. 102, on prima facie obviousness’ under 35 U.S.C. 103, jointly or alternatively, the burden of proof is the same, and its fairness is evidenced by the PTO’s inability to manufacture products or to obtain and compare prior art products." In re Best, 562 F.2d 1252, 1255, 195 USPQ 4380, 483-34 (CCPA 1977)), see MPEP 2112. Applicant has not clearly shown an unobvious difference between the instant invention and the prior art’s product.
It is also noted that the courts have stated where the claimed ranges, such as those regarding surface area, “overlap or lie inside the ranges disclosed by the prior art” and even when the claimed ranges and prior art ranges do not overlap but are close enough that one skilled in the art would have expected them to have similar properties, a prima facie case of obviousness exists (see In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990); Titanium Metals Corp. of America v. Banner, 778 F2d 775. 227 USPQ 773 (Fed. Cir. 1985) (see MPEP 2144.05.01).
The courts have also found that “where the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation.” In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955). See MPEP 2144.05 II.
Therefore, the claimed ranges merely represent an obvious variant and/or routine optimization of the values of the cited prior art.
Accordingly, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention to use the method of Nakanaga to arrive at a composition with surface areas up 16 m2/g because Nakanaga teaches that silica particles with these surface areas are effective at reducing aggregation (Nakanaga, [0006] and [00029]) and which would possess the remaining properties described by the limitations of claim 1 as an inherent property.
Alternatively, one of ordinary skill in the art would have been motivated to use particles with surface areas of less than 30 m2/g because Mihashi teaches that particles with these surface areas will have high flowability (Mihashi, [Overview]). One of ordinary skill in the art would have also been motivated to optimize the heating profile by routine optimization to arrive at a composition with the instantly claimed properties because it is known in the art that heating to remove bound water and surface silanol increases fluidity of non-porous spherical silica products (Mihashi, paragraph 46).
Regarding claim 3, Nakanaga teaches the spherical silica powder of claim 1, and further teaches that the particles generated have a high degree of circularity, which appears to overlap with and exceed 0.85, as evidenced by the highly circular particles depicted in Fig. 6.
Regarding claim 4, Nakanaga teaches the spherical silica powder of claim 1, and further teaches that the powder has been surface-treated with a surface treating agent (surface-modified with a surface modifier, paragraph 13).
Claims 5-8 are rejected under 35 U.S.C. 103 as being unpatentable over Nakanaga in view of Mihashi et al. (JP 2005022915 A), as applied to claim 1 above, and further in view of Matsukubo (WIPO Pat. Pub. 2011/093142 A1). The previously provided English machine translations for Nakanaga (JP200316571), Mihashi (JP2005022915), and Matsukubo (WO2011093142) are referenced below.
Regarding claims 5-8, Nakanaga teaches a product that would have the properties required by claim 1, as analyzed above, and also teaches that their product is monodisperse (paragraph 1). Nakanaga does not teach incorporation of this product into a resin, as required by claims 5-8.
However, Matsukubo teaches a monodisperse spherical silica blended into a resin and used (abstract and page 4, paragraphs 3-7), as required by claim 5, and the resin composition containing said silica (abstract), as required by claim 6. Matsukubo also teaches the resin composition wherein the resin is a polyphenylene ether (page 4, paragraph 3), meeting the limitations of claim 7, and wherein the resin can be cured to obtain a cured product (photocurable resins, page 4, paragraph 4), meeting the limitations of claim 8.
Therefore, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to apply the spherical silica powder of Nakanaga to make the resins taught by Matsukubo. One of ordinary skill in the art would have been motivated to do so because Matsukubo teaches that monodisperse, surface-treated, spherical silica compositions that have been heat-treated (page 3, paragraph 7), and are therefore closely analogous to those described by Nakanaga, make suitable resin additives (abstract).
Response to Arguments
Applicant's arguments filed 3 December 2025 have been fully considered but they are not persuasive.
Applicant argues on page 4 that Nakanaga fails to disclose the claimed feature “wherein the spherical silica powder satisfies B/A of 0.2 or more and 3.0 or less.” However, evaluation of the FT IR spectrum provided by Nakanaga shows that their composition satisfies this limitation, as analyzed above.
Furthermore, Applicant’s arguments that one of ordinary skill in the art would not have expected this combination of features to have a beneficial effect on lowering the dielectric loss tangent of a resin composition are not persuasive.
At the time of filing it was known in the art the IR features found near 3680 cm--1 are caused by internal silanol OH groups (JP H02289416 A, Table 2, translated below), and that such silanol groups are removed as water upon heating to 600-1000 °C (JP H02289416 A, Overview: Constitution). It was further known that lower amounts of water that can be removed from a silica particle correspond to lower dielectric loss tangents (US 2020/0190332 A1, [0091]). Therefore one of ordinary skill in the art would have expected that low values of B/A correspond to low dielectric loss tangents of materials including these particles. Applicant has shown nothing critical about the claimed range of 0.2 or more to 3.0 or less relative to what would be expected by simple minimization of the quantity corresponding to minimizing the IR signature of silanols that can be removed as water.
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English machine translation of Table 2 from JP H02289416 A.
It is further noted that arguments presented by the applicant cannot take the place of evidence in the record. In re Schulze, 346 F.2d 600, 602, 145 USPQ 716, 718 (CCPA 1965) and In re De Blauwe, 736 F.2d 699, 705, 222 USPQ 191, 196 (Fed. Cir. 1984). Examples of statements which are not evidence and which must be supported by an appropriate affidavit or declaration include statements regarding unexpected results.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Nicholas A Piro whose telephone number is (571)272-6344. The examiner can normally be reached Mon-Fri, 8:00 am-5:00 pm.
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/NICHOLAS A. PIRO/Assistant Examiner, Art Unit 1738
/PAUL A WARTALOWICZ/Primary Examiner, Art Unit 1735