Prosecution Insights
Last updated: April 18, 2026
Application No. 18/723,051

Precipitated Silica and Process for Its Manufacture

Final Rejection §103
Filed
Jun 21, 2024
Examiner
PATEL, SMITA S
Art Unit
1732
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Rhodia Operations
OA Round
2 (Final)
70%
Grant Probability
Favorable
3-4
OA Rounds
3y 10m
To Grant
99%
With Interview

Examiner Intelligence

Grants 70% — above average
70%
Career Allow Rate
289 granted / 412 resolved
+5.1% vs TC avg
Strong +57% interview lift
Without
With
+56.8%
Interview Lift
resolved cases with interview
Typical timeline
3y 10m
Avg Prosecution
20 currently pending
Career history
432
Total Applications
across all art units

Statute-Specific Performance

§101
0.1%
-39.9% vs TC avg
§103
49.7%
+9.7% vs TC avg
§102
12.7%
-27.3% vs TC avg
§112
22.9%
-17.1% vs TC avg
Black line = Tech Center average estimate • Based on career data from 412 resolved cases

Office Action

§103
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 . This application is in response to an amendment filed on 03/16/2016. Claims 1-7,9-10,13-17,21-22,26-27 and 35 are presently pending in this application. Applicant has cancelled claims 8, 11-12, 18-20, 23-25, 28-34, and applicant has amended claims 1 and 14. Claims 14-17,21-22,26-27 and 35 have been withdrawn as non-elected groups II-V. Claims 1-7, 9-10, 13 are under examination. 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. Claim(s) 1-4 and 13 are rejected under 35 U.S.C. 103 as obvious over Allain (US PGPUB No.: 20110178227 A1). Regarding claims 1-4, Allain discloses precipitated silica having a primary particles having an average size measured by SAXS of 2-10 nm and further discloses that small primary particles are aggregated or not aggregated together, that is to say not connected to aggregate of large primary particles (meets claimed limitation of below 11 nm, see paragraphs 0328-0330, 0220-0227, reads on small primary particles are considered to be one and only one population as it is not connected to large primary particle), CTAB range from 60-400 m2/g (overlaps the claimed range of 40-300 m2/g, of claim 1, overlaps claimed range of 50-300 m2/g of claim 2, meets the limitation of 150-210 m2/g of claim 3, see paragraph 0335). Further, Allain discloses a median particle size d50 measured by centrifugal sedimentation (paragraph 0154) such that: |d50|<-0.782x|CTAB| +255 (I) (see paragraphs 0434, 0436- example 3- where CTAB is 183m2/g and when plug 183 into the equation <-0.782 x |183| +255 would result to 112 (right side of equation I). Allain further discloses d50 is 83nm (left side of equation, see example 3- paragraph 0436) so therefore d50 which is 83 nm is less than 112 and would meet the equation limitation of claim 1 and would also encompass claimed limitation between 50-200 nm of claim 4). Although there is no disclosure that the test method is conformity with “measured by SAXS” and “measured by centrifugal sedimentation”, given that the Allain discloses primary particles measured by SAXS and median particle size d50 measured by centrifugal sedimentation as the presently claimed and absent evidence criticality how the primary particles measured by SAXS and median particle size d50 measured by centrifugal sedimentation is measured, it is an examiner's position that hardness disclosed by Allain to meet the claim limitation. Given that Allain discloses CTAB range from 60-400 m32/g which overlaps the claimed range of 40-300 m2/g of claim 1 and 50-300 m2/g of claim 2, a prima facie case of obviousness exists. As set forth in MPEP 2144.05, in the case where the claimed range “overlap or lie inside ranges disclosed by the prior art”, a prima facie case of obviousness exists, 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). Regarding Claim 13, Allain 1discloses precipitated silica which is either in the form of powder or in the form of granules (see paragraphs 0001, 0077, 0078, 0345-0346). Claim(s) 5-6, 8-9 and 13 are rejected under 35 U.S.C. 103 over Allain (US PGPUB No.: 20110178227 A1 - refer to as Allain 1) in view of Allain et al (WO2018202752 A1- refer to as Allain 2, IDS cited reference by applicant). Regarding claim 5, Allain 1 discloses precipitated silica having primary particles having an average size measured by SAXS of 2-8 nm (meets claimed limitation of below 11 nm, see paragraphs 0328-0330, 0227), CTAB range from 60-400 m2/g (overlaps the claimed range of 40-300 m2/g, of claim 1, paragraph 0335). As set forth in MPEP 2144.05, in the case where the claimed range “overlap or lie inside ranges disclosed by the prior art”, a prima facie case of obviousness exists, 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). Further, Allain 1 discloses a median particle size d50 measured by centrifugal sedimentation (paragraph 0154) such that: |d50|<-0.782x|CTAB| +255 (I) (see paragraphs 0434, 0436- example 3- where CTAB is 183m2/g and when plug 183 into the equation <-0.782 x |183| +255 would result to 112 (right side of equation I). Allain 1 further discloses d50 is 83nm (left side of equation, see example 3- paragraph 0436) so therefore d50 which is 83 nm is less than 112 and would meet the equation limitation of claim 1. Allain 1 does not explicitly disclose or suggest d50 from 85 to 130 nm of claim 5. However, Allain 2 discloses precipitated silica having CTAB surface area of 40-300 m2/g (paragraph 0013, see table 1), disclosed d50 greater than 65 nm, greater than 70 nm even, equal to or greater than 80 nm and does not exceed 300nm (see paragraphs 0042-0043 and table 1), reads on claims 4-5), d84 ranges from 248-439 (see table s1-s10). As set forth in MPEP 2144.05, in the case where the claimed range “overlap or lie inside ranges disclosed by the prior art”, a prima facie case of obviousness exists, 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). Therefore given both Allain 1 and Allain 2 discloses precipitated silica and directed to elastomer, therefore it would have been obvious to one of the ordinary skill in the art at before the effective filing date of applicant invention to modify the invention of Allain 1 to include d50 in a range of 85-130 nm of Allain 2 which would provide good mechanical properties and/or reduced energy dissipation in elastomeric composition as taught by Allain 2 (see paragraph 0008). Regarding Claim 6, Since Allain 1 discloses precipitated silica having CTAB value from 60-400 m2/g (paragraph 0335) and Allain 2 discloses CTAB value from 40-300 m2/g, (paragraph 0013), therefore when plug value of CTAB, for example 60 m2/g, into the equation as shown below, d84 would be expected to be less than right side of the equation as claimed unless unexpected results are shown: d84<-2.08x|CTAB|+659 d84<-2.08x|60|+659 d84<534 Regarding claim 7, Allain 2 discloses d84 in range from 248-439 overlaps claimed range of 130-430nm (see table s1-s10 of Allain 2). As set forth in MPEP 2144.05, in the case where the claimed range “overlap or lie inside ranges disclosed by the prior art”, a prima facie case of obviousness exists, 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). Regarding claim 9, Since Allain 1 discloses precipitated silica having CTAB value from 60-400 (paragraph 0335) and Allain 2 discloses CTAB value from 40-300 m2/g, (paragraph 0013), therefore when plug value of CTAB, for example 60 m2/g, into the claimed equation as shown below, FWHM would be expected to be less than the right side of the equation unless otherwise unexpected results are shown by the applicant: |FWHM|<250-0.815xCTAB |FWHM|<250-0.815x60 |FWHM|<201 Regarding Claim 10, Since Allain 1 discloses precipitated silica having CTAB value from 60-400 (paragraph 0335) and Allain 2 discloses CTAB value from 40-300 m2/g, (paragraph 0013), therefore when plug value of CTAB, for example 60 m2/g, into the equation as shown below, rate of fines (rf) would be expected to be greater than equal to right side of the equation as claimed unless unexpected results are shown: |rf|≥-0.045x|CTAB| + 84 |rf|≥81 Regarding claim 13, Allain 2 discloses precipitated silica which is in form of powder (paragraph 0097) or in granules form (paragraph 0099). Allain 1discloses precipitated silica which is either in the form of powder or in the form of granules (see paragraphs 0001, 0077, 0078, 0345-0346). Response to Arguments Applicant’s arguments, see applicant remarks on pages 7-10, filed on 03/16/2026 with respect to the rejections of Claims 1-4, 13 under 35 U.S.C. § 102(a)(1) over Allain (US PGPUB No.: 20110178227 A1) has been withdrawn and rejections of Claims 1-4, 13 under 35 U.S.C. § 103 over Allain (US PGPUB No.: 20110178227 A1) and Claims 5-6, 8-9 and 13 are rejected under 35 U.S.C. § 103 over Allain (US PGPUB No.: 20110178227 A1 - refer to as Allain 1) in view of Allain et al (WO2018202752 A1- refer to as Allain 2, IDS cited reference by applicant) are not persuasive and therefore the rejections have been maintained. Applicant mainly argues that Allain ‘227 does not disclose precipitated silica having one and only one population of primary particles based on SAXS measured profile based on the amended claim 1 limitation. However, though Allain ‘227 does discloses that applicant’s argument is not persuasive as Allain ‘227 discloses firstly that determination of the particle size distribution of the small primary particle (<10 nm) and determination of the particle size distribution of large primary particles (>10 nm) are carried out separately (See paragraphs 0222-0223) and further discloses that preferably, in the precipitated silica, there are very few, indeed even no, isolated small primary particles aggregated or not aggregated together, that is to say not connected to aggregates of large primary particles so therefore small primary particles does not contain large primary particles which means that primary particles (i.e., small primary particles) measured by SAXS below 11nm are one and only one population of primary particles measured. Further, presently claim discloses “having” which does not exclude other primary particles present. Therefore the rejections are maintained as set forth below. Further, amendment to abstract overcomes the specification objection of record. 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. Any inquiry concerning this communication or earlier communications from the examiner should be directed to SMITA S PATEL whose telephone number is (571)270-5837. The examiner can normally be reached on 9AM-5PM EST M-W. Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR). If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Ching-Yiu Fung can be reached on 5712705713. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of an application may be obtained from the Patent Application Information Retrieval (PAIR) system. Status information for published applications may be obtained from either Private PAIR or Public PAIR. Status information for unpublished applications is available through Private PAIR only. For more information about the PAIR system. Should you have questions on access to the Private PAIR system, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative or access to the automated information system, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. /SMITA S PATEL/Primary Examiner, Art Unit 1732 04/02/2026
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Prosecution Timeline

Jun 21, 2024
Application Filed
Dec 08, 2025
Non-Final Rejection — §103
Mar 16, 2026
Response Filed
Apr 02, 2026
Final Rejection — §103 (current)

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Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

3-4
Expected OA Rounds
70%
Grant Probability
99%
With Interview (+56.8%)
3y 10m
Median Time to Grant
Moderate
PTA Risk
Based on 412 resolved cases by this examiner. Grant probability derived from career allow rate.

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