Prosecution Insights
Last updated: April 19, 2026
Application No. 18/286,298

ION-EXCHANGE METHODS AND ION-EXCHANGED GLASS ARTICLES MADE USING THE SAME

Non-Final OA §103
Filed
Oct 10, 2023
Examiner
SNELTING, ERIN LYNN
Art Unit
1741
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Corning Incorporated
OA Round
1 (Non-Final)
70%
Grant Probability
Favorable
1-2
OA Rounds
3y 3m
To Grant
99%
With Interview

Examiner Intelligence

Grants 70% — above average
70%
Career Allow Rate
563 granted / 808 resolved
+4.7% vs TC avg
Strong +34% interview lift
Without
With
+33.7%
Interview Lift
resolved cases with interview
Typical timeline
3y 3m
Avg Prosecution
35 currently pending
Career history
843
Total Applications
across all art units

Statute-Specific Performance

§101
0.5%
-39.5% vs TC avg
§103
47.4%
+7.4% vs TC avg
§102
14.8%
-25.2% vs TC avg
§112
32.6%
-7.4% vs TC avg
Black line = Tech Center average estimate • Based on career data from 808 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 . Election/Restrictions Applicant’s election without traverse of Group I, claims 1-18, in the reply filed on 12-29-2025 is acknowledged. Claims 19-20 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected invention, there being no allowable generic or linking claim. Election was made without traverse in the reply filed on 12-29-2025. 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) 1-3, 6-15, and 18 is/are rejected under 35 U.S.C. 103 as being unpatentable over Li ‘243 (US 2020/0102243 A1). Regarding claims 1 and 3, Li ‘243 teaches: exposing a glass article comprising a thickness ranging from 20 microns to 200 microns to a molten salt (¶ [0114], [0135], [0181]), the molten salt comprising: 2 wt% to 10 wt% of an inorganic non-hydroxide salt that is selected from the group consisting of potassium carbonate (K2CO3) or potassium phosphate (K3PO4) (¶ [0186]-[0187], [0190]) 85 wt% to 98 wt% potassium nitrate (KNO3) (¶ [0186]-[0188]) less than 1 wt% sodium nitrate (NaNO3) (¶ [0186]-[0187], [0189]) inducing a compressive stress region extending from a surface of the glass article to a depth of compression and comprising a compressive stress of 700 MPa or more by ion-exchanging between the glass article and the molten salt (¶ [0114], [0129], [0181]). Regarding the ranges of the glass article thickness and the percentages of the molten salt constituents, the claimed ranges overlap the ranges disclosed by Li ‘243. It has been held that in the case where the claimed ranges overlap or lie inside ranges disclosed by the prior art, a prima facie case of obviousness exists. See MPEP 2144.05. Regarding the inorganic non-hydroxide salt, Li ‘243 does not explicitly teach that the percentage is sufficient to provide a pH from 9 to 12 when 5 grams of the inorganic non-hydroxide salt is dissolved in 100 grams of distilled water. However, Li ‘243 teaches the same species of inorganic non-hydroxide salt as disclosed by Applicant’s specification as having such a property (potassium carbonate (K2CO3) or potassium phosphate (K3PO4). It has been held that where the claimed and prior art products are identical or substantially identical in structure or composition, a prima facie case of either anticipation or obviousness has been established. See MPEP 2112.01. Since the inorganic non-hydroxide salts disclosed by Li ‘243 are identical to those disclosed and claimed by the Applicant, Li ‘243 anticipates and/or renders obvious the property of the inorganic non-hydroxide salt being sufficient to provide a pH from 9 to 12 when 5 grams of the inorganic non-hydroxide salt is dissolved in 100 grams of distilled water as claimed. Regarding claim 2, Li ‘243 further teaches the molten salt comprises 5 wt% to 10 wt% of the inorganic non-hydroxide salt (¶ [0186]-[0187], [0190]). Regarding claim 6, Li ‘243 teaches the molten salt contains sodium from NaNO3, and wherein such content includes the range of 0 to less than 1 wt%, as recited in claim 1 (¶ [0187], [0189]). Such a range would also include a sodium concentration ranging from 900 ppm to 4000 ppm in embodiments in which NaNO3 is the only sodium-containing constituent of the molten salt. Regarding claims 7-8, Li ‘243 teaches subjecting the glass article comprising the surface compressive stress of 700 MPa or more to a pen drop test to measure impact resistance defined by the capability of the surface of the glass article to avoid failure at a pen drop height measured in cm (¶ [0205]-[0206]), and shows that glass articles comprising the surface compressive stress of 700 MPa are capable of avoiding failure at height in the range of 15 cm to 25 cm (Table 9). The glass articles of Li ‘243 are not described as being subjected to any etching processes configured to etch a layer from the surface of the glass article. Li ‘243 is silent regarding comparing a pen drop height of the glass article comprising the surface compressive stress of 700 MPa to a pen drop height of the glass article before exposure to the molten salt. However, Li ‘243 expresses a desire to maximize drop performance and damage resistance of the ion-exchanged glass articles (Abstract; ¶ [0113], [0129]), and thus it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the method of Li ‘243 by maximizing a value of Y relative to a value of X as claimed. Regarding claim 9, the method disclosed by Li ‘243 is devoid of an etching process configured to etch a layer from the surface of the glass article comprising the compressive stress of 700 MPa or more. Regarding claims 10-11, Li ‘243 further teaches the compressive stress is 800 MPa or more, and the compressive stress ranges from 800 MPa to 1100 MPa (¶ [0129]). Regarding claim 12, Li ‘243 further teaches the depth of compression is greater than 10% of the thickness of the glass article (¶ [0008], [0133], [0149]). Regarding claim 13, Li ‘243 further teaches the molten salt comprises a temperature ranging from 350°C to 500°C, and wherein the glass article is exposed to the molten salt for a time period ranging from 5 minutes to 120 minutes (¶ [0192]). Regarding claim 14, Li ‘243 further teaches the glass article comprises an alkali aluminosilicate glass (¶ [0165]). Regarding claim 15, Li ‘243 further teaches the glass article comprises an alkali borosilicate glass (¶ [0165]). Regarding claim 18, Li ‘243 further teaches the glass article comprises less than 0.1 mol% Li2O (¶ [0173]), wherein the claimed range overlaps the range disclosed by Li ‘243. See MPEP 2144.05. Claim(s) 4-5 is/are rejected under 35 U.S.C. 103 as being unpatentable over Li ‘243 (US 2020/0102243 A1) in view of Fujiwara ‘773 (US 2020/0055773 A1). Regarding claims 4-5, Li ‘243 is silent regarding a pH of the molten salt. In analogous art of ion exchanging of glass articles, Fujiwara ‘773 suggests making a pH of molten salt for ion exchange in a range of 7.5-10.5, which falls in the claimed ranges, for the benefit of enabling cutting of Si-O-Si bonds so that the compressive stress layer can be modified to thereby form a low-density layer in the glass surface (¶ [0125]-[0129], [0148]). It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the method of Li ‘243 by making the pH of the molten salt comprise a pH ranging from 7.5-10.5 for the benefit of enabling cutting of Si-O-Si bonds so that the compressive stress layer can be modified to thereby form a low-density layer in the glass surface, as suggested by Fujiwara ‘773. Claim(s) 16-17 is/are rejected under 35 U.S.C. 103 as being unpatentable over Li ‘243 (US 2020/0102243 A1) in view of Gross ‘412 (US 2019/0256412 A1). Regarding claim 16, Li ‘243 further teaches the glass article comprises and alkali aluminosilicate composition (¶ [0165]), but is silent regarding the particular composition claimed. In analogous art of ion exchanging of glass articles, Gross ‘412 suggests an alkali aluminosilicate glass composition for ion exchanging comprising: 60-70 mol% SiO2 (¶ [0034]) 7.5-20 mol% Al2O3 (¶ [0034]) 0.1-7.5 mol% MgO (¶ [0034]) 12.5-19 mol% Na2O (¶ [0034]) at least one of 0.5-4 mol% K20, 0.1-5 mol% CaO, or 0.1-5 mol% B2O3 (¶ [0034]) wherein the claimed ranges overlap the ranges disclosed by Li ‘243. See MPEP 2144.05. It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the method of Li ‘243 by using a composition of the glass article as suggested by Gross ‘412 as a substitution of alkali aluminosilicate glass compositions for ion exchange. Regarding claim 17, Li ‘243 further teaches the glass article comprises and alkali aluminosilicate composition (¶ [0165]), but is silent regarding the particular composition claimed. In analogous art of ion exchanging of glass articles, Gross ‘412 suggests an alkali aluminosilicate glass composition for ion exchanging comprising: 65-70 mol% SiO2 (¶ [0034]) 7.5-12.5 mol% Al2O3 (¶ [0034]) 2.5-7.5 mol% MgO (¶ [0034]) 12.5-17.5 mol% Na2O (¶ [0034]) wherein the claimed ranges overlap the ranges disclosed by Li ‘243. See MPEP 2144.05. It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the method of Li ‘243 by using a composition of the glass article as suggested by Gross ‘412 as a substitution of alkali aluminosilicate glass compositions for ion exchange. Conclusion The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. US 2020/0095162 A1 suggests that pH of a molten salt for ion exchange can affect the formation of haze on the glass substrate being treated (¶ [0043]). Any inquiry concerning this communication or earlier communications from the examiner should be directed to Erin Snelting whose telephone number is (571)272-7169. The examiner can normally be reached Monday to Friday, 8:00 to 5:00. 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, Alison Hindenlang can be reached at (571) 270-7001. 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. /ERIN SNELTING/Primary Examiner, Art Unit 1741
Read full office action

Prosecution Timeline

Oct 10, 2023
Application Filed
Feb 05, 2026
Non-Final Rejection — §103
Apr 09, 2026
Applicant Interview (Telephonic)
Apr 09, 2026
Examiner Interview Summary

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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
70%
Grant Probability
99%
With Interview (+33.7%)
3y 3m
Median Time to Grant
Low
PTA Risk
Based on 808 resolved cases by this examiner. Grant probability derived from career allow rate.

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