Prosecution Insights
Last updated: April 19, 2026
Application No. 18/289,369

Glass Fiber Composition with Low Dielectric Loss

Non-Final OA §103
Filed
Nov 03, 2023
Examiner
PATEL, RONAK C
Art Unit
1788
Tech Center
1700 — Chemical & Materials Engineering
Assignee
China National Building Material Group Co. Ltd.
OA Round
1 (Non-Final)
50%
Grant Probability
Moderate
1-2
OA Rounds
3y 8m
To Grant
99%
With Interview

Examiner Intelligence

Grants 50% of resolved cases
50%
Career Allow Rate
326 granted / 645 resolved
-14.5% vs TC avg
Strong +57% interview lift
Without
With
+56.7%
Interview Lift
resolved cases with interview
Typical timeline
3y 8m
Avg Prosecution
56 currently pending
Career history
701
Total Applications
across all art units

Statute-Specific Performance

§101
0.2%
-39.8% vs TC avg
§103
70.1%
+30.1% vs TC avg
§102
6.9%
-33.1% vs TC avg
§112
18.0%
-22.0% vs TC avg
Black line = Tech Center average estimate • Based on career data from 645 resolved cases

Office Action

§103
CTNF 18/289,369 CTNF 86720 DETAILED ACTION Notice of Pre-AIA or AIA Status 07-03-aia AIA 15-10-aia The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA. Claim Rejections - 35 USC § 103 07-20-aia AIA 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. 07-21-aia AIA Claim (s) 1 and 3 are rejected under 35 U.S.C. 103 as being unpatentable over Li et al. (US 2018/0127305) in view of Inaka et al. (US 2020/0087196) . Regarding claims 1, 3 Li discloses glass composition as described herein can include 50 to 55 weight percent SiO.sub.2, 17 to 26 weight percent B.sub.2O.sub.3, 13 to 19 weight percent Al.sub.2O.sub.3 , 0-8.5 weight percent of MgO , 0 to 6 weight percent CaO , 0 to 1.5 weight percent Li.sub.2O, 0 to 1.5 weight percent F.sub.2, 0 to 1 weight percent Na.sub.2O , and 0 to 8 weight percent of other constituents. Also described herein are glass fibers formed from such compositions (abstract). However, Li fails to disclose that the glass fiber composition comprises SnO2 in an amount of 0.05-0.5% and the claimed mass percentage content of SnO2 and Li2O and mass percentage content of F2 and SnO2. Whereas, Inaka discloses glass composition of the present disclosure includes, in wt %, 50≤SiO.sub.2≤56, 20≤B.sub.2O.sub.3≤30, 10≤Al.sub.2O.sub.3≤20, 3.5≤MgO+CaO≤10, and 0≤R.sub.2O≤1.0 (abstract). The glass composition of the present disclosure may contain, as an additive, at least one selected from SnO.sub.2, provided that the content of each of these additives is 0% or more and 1% or less (para 0075). It would have been obvious to one of ordinary skill in the art at the time the application was filed to include SnO2 in an amount of 0-1 wt% as taught by Inaka in the glass fiber composition of Li motivated by the desire to have increase electrical performance and enhances thermal stability. Thus, based from the disclosure of Li and Inaka, if the amount of SnO2 and Li2O is 0.5-1 wt%, it would intrinsically satisfy the claimed range for SnO2/Li2O and if the amount of SnO2 and F2 is 0.5-1 wt%, it would intrinsically satisfy the claimed range of F2/SnO2. As Li in view of Inaka discloses glass fiber composition with contents as claimed, therefore the glass fiber composition would intrinsically have low dielectric loss . 07-21-aia AIA Claim (s) 2 and 4 are rejected under 35 U.S.C. 103 as being unpatentable over Li et al. (US 2018/0127305) in view of Inaka et al. (US 2020/0087196) as applied to claim 1, further in view of Hausrath et al. (US 2020/0216351) . Regarding claims 2, 4 Li in view of Inaka fails to disclose that the glass fiber composition further discloses P2O5 in an amount of 0.05-5 wt% and mass percentage content of P2O5, F2 and SnO2 in a range of 2-5. Whereas, Hausrath discloses glass compositions and glass fibers having low dielectric constants and low dissipation factors that may be suitable for use in electronic applications and articles are disclosed. The glass fibers and compositions of the present invention may include between 48.0 to 57.0 weight percent SiO.sub.2; between 15.0 and 26.0 weight percent B.sub.2O.sub.3; between 12.0 and 18.0 weight percent Al.sub.2O.sub.3; between greater than 3.0 and 8.0 weight percent P.sub.2O.sub.5; between greater than 0.25 and 7.00 weight percent CaO (abstract). The glass fiber of the present invention typically also includes a composition having between greater than 3 and 8 weight percent phosphorus oxide (P.sub.2O.sub.5, also referred to as phosphorous pentoxide). Alternatively, the phosphorous oxide content may be between greater than 3 and 7.5 weight percent. Further alternatively, the phosphorous oxide content may be between greater than 3 and 7 weight percent. The inventors surprisingly found that this range is optimal for balancing the Df behavior with the T.sub.liq and melt instability index. More specifically, P.sub.2O.sub.5 was found to synergistically associate with the Al.sub.2O.sub.3 content of the glass, thereby decreasing the melt stability (para 0062). It would have been obvious to one of ordinary skill in the art at the time the application was filed to include P2O5 in an amount 3-8 wt% as taught by Hausrath in the glass fiber composition of Li motivated by the desire for balancing the Df behavior and melt instability index. Thus, based from the disclosure of Li, Inaka and Hausrath if the amount of SnO2, F2 and P2O5 are in claimed range as disclosed above it would intrinsically satisfy the claimed mass percentage range. Thus, based from the disclosure of Li and Inaka, if the amount of SnO2 and Li2O is 0.5-1 wt%, it would intrinsically satisfy the claimed range for SnO2/Li2O and if the amount of SnO2 and F2 is 0.5-1 wt%, it would intrinsically satisfy the claimed range of F2/SnO2. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to RONAK C PATEL whose telephone number is (571)270-1142. The examiner can normally be reached M-F 8:30AM-6:30PM (FLEX). 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) at http://www.uspto.gov/interviewpractice. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, ALICIA CHEVALIER can be reached at 5712721490. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. /RONAK C PATEL/Primary Examiner, Art Unit 1788 Application/Control Number: 18/289,369 Page 2 Art Unit: 1788 Application/Control Number: 18/289,369 Page 3 Art Unit: 1788 Application/Control Number: 18/289,369 Page 4 Art Unit: 1788 Application/Control Number: 18/289,369 Page 5 Art Unit: 1788
Read full office action

Prosecution Timeline

Nov 03, 2023
Application Filed
Mar 04, 2026
Non-Final Rejection — §103 (current)

Precedent Cases

Applications granted by this same examiner with similar technology

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PELLETS OF A GLASS FIBER-REINFORCED THERMOPLASTIC POLYMER COMPOSITION, AND METHOD OF THEIR MANUFACTURE
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Patent 12573629
CATHODE MATERIAL FOR SULFIDE-BASED ALL-SOLID-STATE BATTERIES, MANUFACTURING METHOD THEREOF, AND ALL-SOLID-STATE BATTERY USING THE SAME
2y 5m to grant Granted Mar 10, 2026
Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

1-2
Expected OA Rounds
50%
Grant Probability
99%
With Interview (+56.7%)
3y 8m
Median Time to Grant
Low
PTA Risk
Based on 645 resolved cases by this examiner. Grant probability derived from career allow rate.

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