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 .
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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 April 27, 2026 has been entered.
Information Disclosure Statements
The information disclosure statement (IDS) submitted on January 15, 2026 was filed after the mailing date of the Non-Final Office Action on June 30, 2025. The submission includes a timing statement and is in compliance with the provisions of 37 CFR 1.97. Accordingly, the information disclosure statement is being considered by the examiner.
The information disclosure statement (IDS) submitted on May 19, 2026 was filed after the submission of the request for continued examination on April 27, 2026 and prior to the mailing of any Office action on the merits following the submission of the request for continued examination. The submission is in compliance with the provisions of 37 CFR 1.97. Accordingly, the information disclosure statement is being considered by the examiner.
Response to Amendment
The reply filed on April 27, 2026 has been entered into the prosecution for the application. Currently, claims 1-19 and 21 are pending, with claims 14-19 having been withdrawn. Claim 20 has been cancelled. Claims 1, 14, and 18 have been amended.
All prior art grounds of rejection are withdrawn.
Applicant’s amendments necessitated the new grounds of rejection.
Claim Rejections - 35 USC § 103
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.
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.
Claim(s) 1-13 are rejected under 35 U.S.C. 103 as being unpatentable over U.S. Pat. Pub. 2019/0160201 to Deng et al. (hereinafter “Deng”).
Regarding claim 1, Deng teaches a glass-ceramic article (¶ 0020) comprising a crystalline phase (¶ 0022) and a residual glass phase (¶ 0041), the glass-ceramic article comprising a composition with the following components (p. 4, Table 1, Example 6):
Component
Claim 1 (mol%)
Deng, Ex. 6 (wt.%)
Deng, Ex. 6 (mol%)
SiO2
52 – 70
60
61.5
Li2O
14 – 35
12
24.7
CaO
5 – 15
6
6.6
ZrO2
greater than 2 to 10
4
2.0
P2O5
0.5 – 5
4
1.7
Al2O3
2.5
1.5
Na2O
2
2.0
As shown in the table above, Deng teaches a glass-ceramic article that has component proportions which, when expressed in mol%, fall within the claimed ranges, except for ZrO2, where Example 6 of Deng includes an amount that is just outside the claimed range. A prima facie case of obviousness exists where the claimed ranges or amounts do not overlap but are merely close (see MPEP 2144.05(I), second paragraph). Moreover, Deng teaches that the glass-ceramic article may comprise from 0.5 to 8 wt.% ZrO2 (see ¶ 0042; claim 1). One of ordinary skill in the art, selecting a content of ZrO2 from within the full range taught by Deng, would have found it obvious to select a slightly higher ZrO2 content than the 4 wt.% ZrO2 used in Example 6, thereby raising the molar percentage of ZrO2 and producing a glass-ceramic article reading on every limitation of claim 1 as amended.
Regarding claim 2, Deng teaches the glass-ceramic article wherein the crystalline phase comprises lithium disilicate, wherein lithium disilicate is present in a greater amount, based on a total weight of the crystalline phase, than any other crystalline phase (see ¶ 0022, teaching that lithium disilicate is the “primary major crystal phase”).
Regarding claim 3, Deng teaches the glass-ceramic article according to claim 1 and according to claim 2, as set forth above. Further, Deng teaches that the glass-ceramic article is prepared using a two-step heat treatment process that includes heating at a nucleation temperature of 700°C for 2 hours followed by heating at a crystallization temperature of 800°C for 4 hours (see ¶¶ 0111, 0122). This heat treatment process of preparing the glass-ceramic article is substantially identical to the heat treatment process set forth for the claimed invention (see Specification at ¶¶ 00175-00178). Given that the glass-ceramic article of Deng and the glass-ceramic article of the claimed invention have substantially identical compositions and are prepared by substantially identical processes, one of ordinary skill in the art would reasonably expect that the glass-ceramic article of Deng and the glass-ceramic article of the claimed invention would inherently possess substantially identical properties, including wherein grains of the lithium disilicate comprise a grain size greater than or equal to 10 nm and less than or equal to 200 nm. 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 obviousness has been established (see MPEP 2112.01(I), first paragraph).
Regarding claim 4, Deng teaches the glass-ceramic article wherein the glass-ceramic article comprises 24.7 mol% Li2O (Table 1, Example 6), within the recited range of claim 4.
Regarding claim 5, Deng teaches the glass-ceramic article wherein the glass-ceramic article comprises 2.0 mol% ZrO2 (Table 1, Example 6), very close to the recited range of claim 5. A prima facie case of obviousness exists where the claimed ranges or amounts do not overlap but are merely close (see MPEP 2144.05(I), second paragraph).
Regarding claim 6, Deng teaches the glass-ceramic article wherein the glass-ceramic article comprises 1.7 mol% P2O5 (Table 1, Example 6), within the recited range of claim 6.
Regarding claim 7, Deng teaches the glass-ceramic article wherein a molar ratio of Al2O3 to SiO2 is (1.5/61.5) = 0.024, which is within the recited range of claim 7 (Table 1, Example 6).
Regarding claim 8, Deng teaches the glass-ceramic article wherein a molar ratio of Li2O to SiO2 is (24.7/61.5) = 0.402, which is within the recited range of claim 8 (Table 1, Example 6).
Regarding claim 9, Deng teaches the glass-ceramic article wherein a molar ratio of RO to SiO2 is (6.6/61.5) = 0.107, CaO being the only RO in Example 6 of Deng (see Table 1).
Regarding claim 10, Deng teaches the glass-ceramic article wherein the crystalline phase of the glass-ceramic article comprises β-quartz (see Table 1, Example 6, row 10).
Regarding claims 11-13, Deng teaches the glass-ceramic article according to claim 1, as set forth above. Further, Deng teaches that the glass-ceramic article is prepared using a two-step heat treatment process substantially identical to the heat treatment process of the claimed invention, as set forth above with regard to claim 3 (see p. 5 above). Given that the glass-ceramic article of Deng and the glass-ceramic article of the claimed invention have substantially identical compositions and are prepared by substantially identical processes, one of ordinary skill in the art would reasonably expect that the glass-ceramic article of Deng and the glass-ceramic article of the claimed invention would inherently possess substantially identical properties—including an average transmittance of the glass-ceramic article being greater than or equal to 50% and less than or equal to 95% over the wavelength range of 400 nm to 800 nm as measured at an article thickness of 0.8 mm, a KIc fracture toughness of the glass-ceramic article as measured by a double torsion method that is greater than or equal to 1.0 MPa∙m1/2, and an elastic modulus of the glass-ceramic article being greater than or equal to 100 GPa—since products of identical composition are presumed not to have mutually exclusive properties. 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 obviousness has been established (see MPEP 2112.01(I), first paragraph).
Allowable Subject Matter
Claim 21 is objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
The following is a statement of reasons for the indication of allowable subject matter:
Regarding claim 21, the closest prior art references are Deng and U.S. Pat. Pub. 2023/0174413 to Yuan et al. (hereinafter “Yuan”).
Deng teaches the glass-ceramic article according to claim 1 and claim 2, as set forth above.
However, Deng does not teach wherein the crystalline phase further comprises petalite.
Yuan teaches glass-ceramics (i.e., microcrystalline glass) comprising, in weight percent, 65-80% SiO2, 10-25% Li2O, and 5-15% ZrO2 (Abstract). In particular, Yuan discloses Example 36#, which comprises the following components (data taken from p. 34, Table 12 of Yuan):
Component
Claim 1
(mol%)
Yuan
Example 36#
(wt%)
(mol%)
SiO2
52 – 70
62
60.2
Li2O
14 – 35
13.7
26.8
CaO
5 – 15
1
1
ZrO2
greater than 2 to 10
10
4.7
P2O5
0.5 – 5
2.5
1.0
Na2O
1
0.9
Al2O3
9.3
5.3
Claim 7: Ratio Al2O3/SiO2
0 – 0.2
0.09
Claim 8: Ratio Li2O/SiO2
0.2 – 0.7
0.444
Claim 9: Ratio RO/SiO2
0 – 0.3
0.02
Yuan teaches that the glass-ceramic comprises a crystalline phase and a residual glass phase (see ¶ 0243). Yuan teaches glass-ceramic articles (microcrystalline glass products) comprising the above-described glass-ceramic composition (see ¶ 0388). Yuan teaches the glass-ceramic article wherein the crystalline phase comprises lithium disilicate and wherein lithium disilicate is present in a greater amount, based on a total weight of the crystalline phase, than any other crystalline phase (see ¶ 0250). Yuan teaches wherein the crystalline phase further comprises petalite (see ¶ 0253; claim 96).
However, Yuan does not teach the glass-ceramic article having a content of CaO in the range of greater than 5 mol% to less than or equal to 15 mol%.
Thus, the specific combination of required components set forth in claim 1 is neither taught nor rendered obvious by the prior art of record.
Response to Arguments
Applicant’s arguments with respect to the pending claim(s) have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure:
U.S. Pat. Pub. 2020/0017398 to Click et al. (“Click”) teaches a glass ceramic article including a lithium disilicate crystalline phase, a petalite crystalline phase, and a residual glass phase (Abstract). Click teaches embodiments that include greater than 2 mol% ZrO2 (see, e.g., Compositions 2, 5, 11, and 12 in Table 3, p. 23).
U.S. Pat. Pub. 2009/0162608 to Yagi et al. (“Yagi”) teaches glass-ceramics comprising lithium disilicate as a crystal phase (Abstract). Yagi teaches embodiments in which the glass-ceramic comprises 60-78 wt.% SiO2, 5-12 wt.% Li2O, 4-10wt.% Al2O3, 1.5-3.0 wt.% P2O5, and 1-10 wt.% ZrO2 (¶ 0023; claim 6).
Any inquiry concerning this communication or earlier communications from the examiner should be directed to PAUL A. FORSYTH whose telephone number is (703) 756-5425. The examiner can normally be reached M - Th 8:00 - 5:30 EDT and F 8:00 - 12:00 EDT.
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/P.A.F./Examiner, Art Unit 1731
/AMBER R ORLANDO/Supervisory Patent Examiner, Art Unit 1731
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