CORNING INCORPORATEDDownload PDFPatent Trials and Appeals BoardJan 26, 20212020000493 (P.T.A.B. Jan. 26, 2021) Copy Citation UNITED STATES PATENT AND TRADEMARK OFFICE UNITED STATES DEPARTMENT OF COMMERCE United States Patent and Trademark Office Address: COMMISSIONER FOR PATENTS P.O. Box 1450 Alexandria, Virginia 22313-1450 www.uspto.gov APPLICATION NO. FILING DATE FIRST NAMED INVENTOR ATTORNEY DOCKET NO. CONFIRMATION NO. 16/043,442 07/24/2018 Jaymin Amin SP15-384TA 3819 22928 7590 01/26/2021 CORNING INCORPORATED SP-TI-3-1 CORNING, NY 14831 EXAMINER KEYWORTH, PETER ART UNIT PAPER NUMBER 1777 NOTIFICATION DATE DELIVERY MODE 01/26/2021 ELECTRONIC Please find below and/or attached an Office communication concerning this application or proceeding. The time period for reply, if any, is set in the attached communication. Notice of the Office communication was sent electronically on above-indicated "Notification Date" to the following e-mail address(es): usdocket@corning.com PTOL-90A (Rev. 04/07) UNITED STATES PATENT AND TRADEMARK OFFICE BEFORE THE PATENT TRIAL AND APPEAL BOARD Ex parte JAYMIN AMIN, XIAOJU GUO, TODD LEROY HECK, HONGMEI HU, YUHUI JIN, PASCALE ORAM, and LJERKA UKRAINCZYK Appeal 2020-000493 Application 16/043,442 Technology Center 1700 Before BEVERLY A. FRANKLIN, JEFFREY B. ROBERTSON, and SHELDON M. MCGEE, Administrative Patent Judges. MCGEE, Administrative Patent Judge. DECISION ON APPEAL Pursuant to 35 U.S.C. § 134(a), Appellant1 appeals from the Examiner’s decision to reject claims 1–5, 7, 9–15, and 17–31. We have jurisdiction. 35 U.S.C. § 6(b). We affirm-in-part. 1 We use the word Appellant to refer to “applicant” as defined in 37 C.F.R. § 1.42. Appellant identifies the real party in interest as Corning Incorporated. Appeal Br. 2. Appeal 2020-000493 Application 16/043,442 2 CLAIMED SUBJECT MATTER The claims are directed to methods of regenerating a salt bath containing lithium (Li) ions. Claim 1, reproduced below, is illustrative of the claimed subject matter, with a key limitation italicized for emphasis: 1. A method for regenerating a salt bath comprising: heating a salt bath comprising a phosphate salt and at least one of KNO3 and NaNO3 to a temperature of greater than or equal to 380°C; contacting at least a portion of an ion-exchangeable substrate comprising lithium cations with the salt bath, whereby lithium cations diffuse from the ion-exchangeable substrate and are dissolved in the salt bath; and selectively precipitating, before or between ion-exchange cycles, dissolved lithium cations from the salt bath, wherein the concentration of dissolved lithium in the salt bath is greater than or equal to 0 wt% lithium and less than or equal to 2.0 wt% lithium, and wherein the concentration of lithium cations in the salt bath is greater than or equal to the concentration of phosphate salt in the bath. Figures 1A, 1B, 2A, and 2B are illustrative of the claimed method. Appeal 2020-000493 Application 16/043,442 3 Figure 1A depicts a salt bath 100 containing fresh molten salt 101, ion- exchangeable substrate 105 containing Li ions 130, and alkali metal ions 120. Spec. ¶ 53. Figure 1B depicts a “poisoned” salt bath 100 after an ion- exchange reaction where some of the Li ions 130 in substrate 105 and diffuse and are replaced with “larger alkali metal cations.” Id. ¶¶ 55–56. Figure 2A depicts poisoned salt bath 200 with the ion-exchangeable substrate removed, where poisoned molten salt 202 contains more than 2 % by weight of Li ions, and where “phosphate salt 240 may be added before or after the ion-exchangeable substrate 205 is contacted with the salt bath” to precipitate out the Li ions, thus “regenerat[ing] the poisoned molten salt.” Id. ¶ 57. Figure 2B illustrates regenerated salt bath 200 where the phosphate salt precipitates Li ions out of the salt bath thereby creating insoluble lithium phosphate 250. Id. ¶ 60. Appeal 2020-000493 Application 16/043,442 4 REJECTIONS The Examiner rejects the following claims under 35 U.S.C. § 103: I. Claims 1–5, 7, 9–15, and 17–20 as unpatentable over Imai;2 II. Claims 21–31 as unpatentable over Imai in view of Gomez.3 Final Act. 2–8. OPINION Rejection I We address the claims separately to the extent so argued by Appellant. 37 C.F.R. § 41.37(c)(1)(iv)(2019). Claim 1 The Examiner’s findings regarding Imai and conclusions regarding the obviousness of claim 1 are set forth at pages 2–4 of the Final Office Action. Appellant first argues the prior art Imai reference teaches that its precipitation reaction is carried out “during” the ion exchange reaction and, thus, does not “selectively precipitat[e] before or between ion-exchange cycles” as required by claim 1. Appeal Br. 10–13; Reply Br. 4–5. We are not persuaded by this argument for several reasons. First, the method of claim 1 does not require the selective precipitation of dissolved lithium cations to occur solely before or between ion-exchange cycles. Indeed, claim 1 is open-ended and, as such, may include non-recited steps such as simultaneous precipitation and ion- exchange reactions. Thus, the Examiner’s reliance on a reference that may 2 US 8,919,150 B2, issued December 30, 2014. 3 US 2012/0052271 A1, published March 1, 2012. Appeal 2020-000493 Application 16/043,442 5 also disclose a precipitation reaction occurring during ion exchange does not, by itself, constitute reversible error. Further, Appellant’s focus on Imai’s simultaneous precipitation and ion exchange reactions does not address whether Imai also teaches or suggests selective precipitation of lithium ions “before or between ion exchange cycles.” In this regard, Appellant does not squarely address the totality of the Examiner’s findings that this limitation is met by Imai’s process. Specifically, the Examiner finds that Imai discloses regeneration and reuse of the molten salt bath by adding an additive to precipitate ions, thus “such precipitation reaction would occur before or between ion exchange cycles.” Final Act. 2–3; see also Ans. 3–4 (finding that Imai teaches alternating ion-exchange and precipitation cycles, where an ion- exchange reaction occurs, followed by a precipitation cycle, which then repeats). Because Imai’s precipitation cycle occurs after one ion exchange cycle and before another, the Examiner finds that “the precipitation occurs between the ion exchange cycles” as recited in claim 1. Ans. 3–4. Moreover, the Examiner finds that “Imai teaches that the additive may be added per batch or per several batches while producing a plurality of ion exchanged glass articles.” Ans. 4 (citing Imai 7:51–63). Thus, according to the Examiner, the disputed limitation is met because “the precipitation reaction is an inherent effect of Li ions being in the presence of and reacting with a phosphate salt.” Id. In other words, the Examiner finds that selective precipitation of lithium ions occurs “between ion exchange cycles” in Imai because the ion exchange reaction occurs when the substrate is present within the salt bath; once the substrate is removed, ion exchange ceases, but precipitation continues based on the amount of phosphate present in the salt Appeal 2020-000493 Application 16/043,442 6 bath. See Ans. 4 (finding “as long as the phosphate salt and Li ions are present, the selective precipitating would occur and would overlap the timeframe between batches, even if not explicitly stated.”). Here, we acknowledge Appellant’s argument that, in the claimed method, precipitation would not continue after removing the substrate because the claimed amount of phosphate does not exceed the concentration of lithium ions in solution. See Reply Br. 5 (arguing that in the claimed method, “because the amount of lithium cations is greater than[4] the amount of phosphate salt, all the phosphate salt will be precipitated before or between ion-exchange cycles; there will be no phosphate salt after the precipitating”); see also id. (arguing that, in Imai, “because there is so much phosphate salt, there will not be any unprecipitated lithium cations when the ion exchange cycle is done” thus, “between the end of the first ion exchange cycle and the start of the second ion exchange cycle . . . there will be no precipitation”). This line of argument is unpersuasive, however, because it is an assertion unsupported by evidence. See In re Pearson, 494 F.2d 1399, 1405 (CCPA 1974) (“Attorney’s argument in a brief cannot take the place of evidence.”). In particular, Appellant has not shown that there are no unprecipitated lithium cations present in Imai’s salt bath between ion exchange cycles. Appellant also argues that it would not have been obvious to change Imai’s method step sequence to arrive at the claim limitation requiring the precipitation to occur “before or between ion exchange cycles” as claimed. Appeal Br. 13–14. We need not address this argument, however, because it 4 This argument misstates the claim, which allows the concentration of lithium to equal that of the phosphate salt in the bath. Appeal 2020-000493 Application 16/043,442 7 addresses an alternative rationale relied on by the Examiner regarding this limitation. See Final Act. 3. As discussed supra, we find no error in the Examiner’s finding that Imai teaches selective precipitation occurring “between ion exchange cycles.” Final Act. 2–3; Ans. 3–4. Appellant contends further that the Examiner’s optimization rationale to arrive at the claimed percentages of lithium and phosphate is not supported because the prior art does not recognize the concentration of lithium ions and phosphate salt to be result effective variables. Appeal Br. 14–16. This argument is not persuasive of reversible error because the Examiner finds, and Appellant does not dispute, that the skilled artisan “would immediately recognize that in the case of chemical reactions, the concentration of reactants play a critical role in controlling/optimizing the chemical reaction.” Ans. 5; see Reply Br., generally. Moreover, Imai evinces the result effective nature of lithium ions. Imai 4:56–62 (discussing how the concentration of lithium ions impacts the degree to which sodium and potassium ions can enter the glass substrate upon equilibrium); see also id. at 5:3–5 (“the glass strengthening degree changes along with the change in concentration of Li ions in the molten salt dissolved solution”). Finally, Appellant argues that the Examiner’s reliance on certain percentages previously claimed in now canceled claim 8 is in error. This argument is not persuasive because such reliance on claim 8 was an alternative to the process optimization line of reasoning supporting the rejection (Final Act. 4) for which Appellant has identified no error. In sum, Appellant’s arguments regarding claim 1 fail to identify reversible error in the rejection of this claim. We, therefore, sustain it, along with dependent claims 2–5, 7, 9, 10, and 17 not argued separately. Appeal 2020-000493 Application 16/043,442 8 Claim 11 Claim 11 requires additional steps not recited in claim 1, namely a measuring of the compressive stress of a first substrate after contact with the salt bath, additional measuring of the compressive stresses of subsequent substrates after contact with the salt bath, and adding phosphate salt to the salt bath “when a compressive stress of a subsequent ion-exchangeable substrate is from 10 MPa to 70 MPa less than the compressive stress of the first ion-exchangeable substrate.” The Examiner finds that Imai fails to teach these additional steps, but determines these steps would have been obvious in view of Imai’s teaching that “the process of chemical strengthening allows for the glass substrate to increase its compressive stress,” and because “modifying the order of the process would have been an obvious matter of changing the sequence in the method.” Final Act. 5. Appellant argues that even if the substrates’ compressive stresses were measured to see if it was a desired amount, “there is no cogent line of reasoning as to why that would be used as a factor in determining when to add phosphate salt to the ion-exchange bath to remove lithium ions therefrom.” Appeal Br. 17–18. Rather, according to Appellant, Imai teaches maintaining enough phosphate in the bath so that lithium ions may be discharged during ion exchange “so that the salt bath does not need to be replaced.” Id. at 18. We reverse the rejection of claim 11. The Examiner fails to explain sufficiently why the skilled artisan would have been motivated to modify Imai’s process by adding phosphate to the bath once a difference between compressive stress measurements of between 10 and 70 MPa in the substrate Appeal 2020-000493 Application 16/043,442 9 is observed. Specifically, the rejection appears to conflate the desire to removal of lithium ions from a substrate (e.g., to obtain a given compressive stress (Imai 4:39–46)) with removal of lithium ions from the salt bath by adding phosphate. Furthermore, the Examiner fails to explain how the proffered “order of steps” rationale applies to the facts here. Because the rejection of claim 11 is deficient, we reverse it, along with the rejection of dependent claims 12–15 and 18–20. Rejection II Because we have reversed the rejection of independent claim 11 supra, the rejection of claims 21–25 depending therefrom also will be reversed. Thus, we need only address claims 26–31 because these claims depend from claim 1. Appellant argues this rejection as a group, except for claim 30 which is argued separately. Appeal Br. 18–19. We, therefore, select claims 26 and 30 and decide the appeal of this rejection based on these claims. 37 C.F.R. § 41.37(c)(1)(iv)(2019). Claim 26 For claim 26, Appellant relies on the same arguments presented for claim 1, discussed supra. Because we found those arguments unpersuasive for claim 1, we do so here, and sustain the rejection of claim 26 and claims 27–29 for the same reasons. Claim 30 Claim 30 requires “cooling the ion-exchangeable substrate to a temperature of less than or equal to 100°C in less than or equal to 3 minutes” after it is removed from the salt bath. Appeal 2020-000493 Application 16/043,442 10 The Examiner finds that Imai teaches the substrate is rapidly cooled after being removed from the salt bath and that the skilled artisan would have expected the recited temperature to be achieved in less than or equal to 3 minutes. The Examiner alternatively determines that the claimed cooling rate would have been an obvious matter of routine optimization. Final Act. 7; see also Ans. 6 (“The end temperature of the substrate and the time taken to cool to said temperature are the effects of the method step of the substrate being immersed in a water bath. Relevant factors that would affect the degree and rate of the cooling process would be the temperature of the water bath.”). Appellant argues that the Examiner’s optimization rationale is misplaced because the prior art does not recognize the cooling rate as a result effective variable, “let alone as result-effective of controlling formation of phosphate crystals as Appellant has.” Appeal Br. 18–19. We are unpersuaded by this argument. First, we note that Appellant only presents arguments regarding the Examiner’s optimization rationale, and does not address the Examiner’s finding that the skilled artisan would have expected Imai’s cooling process to achieve the claimed cooling rate. Final Act. 7. Further, Appellant’s arguments do not address the Examiner’s finding that the temperature of the water bath is a result effective variable that would affect the substrate’s cooling rate, and is, therefore, optimizable. Ans. 6; Reply Br., generally. Rather, Appellant appears to argue that a given parameter must be known to be result-effective for the feature with which Appellant is concerned. Appeal Br. 18. This is not the law. In re Applied Materials, Inc., 692 F.3d 1289, 1297 (Fed. Cir. 2012) (“the prior art need not Appeal 2020-000493 Application 16/043,442 11 provide the exact method of optimization for the variable to be result- effective. A recognition in the prior art that a property is affected by the variable is sufficient to find the variable result-effective.”). Because we are unpersuaded of reversible error in the rejection of claim 30, we sustain it, along with the rejection of claim 31 depending therefrom. CONCLUSION The Examiner’s rejection of claims 1–5, 7, 9, 10, 17, and 26–31 is affirmed. The Examiner’s rejection of claims 11–15 and 18–25 is reversed. DECISION SUMMARY Claims Rejected 35 U.S.C. § Basis Affirmed Reversed 1–5, 7, 9–15, 17–20 103 Imai 1–5, 7, 9, 10, 17 11–15, 18– 20 21–31 103 Imai, Gomez 26–31 21–25 Overall outcome 1–5, 7, 9, 10, 17, 26– 31 11–15, 18– 25 TIME PERIOD FOR RESPONSE No time period for taking any subsequent action in connection with this appeal may be extended under 37 C.F.R. § 1.136(a). See 37 C.F.R. § 1.136(a)(1)(iv). AFFIRMED-IN-PART Copy with citationCopy as parenthetical citation