DETAILED ACTION
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.
Claims 6-7 and 9 are rejected under 35 U.S.C. 103 as being unpatentable over Beall et al. (2017/0144921) in view of Liang et al. (CN 110143759 machine translation provided), Yuan et al. (CN 110510879 machine translation provided) and Brodkin et al. (WO 00/34196). Beall teaches a method for preparing a crystalline glass material comprising forming a basic glass plate having a thickness in the range of 0.8 mm to 3 mm ([0179]), i.e. 1mm ([0167]), which falls within the claimed range of 0.2-2 mm and thermally treating the basic glass plate in order to conduct nucleation and crystal growth, thereby preparing the crystalline glass material ([0114], [0188]). Beall further teaches the glass has a composition with a broader range of 55-80 wt% SiO2, 2-20 wt% Al2O3, 5-20 wt% Li2O, 0-5 wt% Na2O, 0-4 wt% K2O, and 0.5-6 wt% P2O5, which overlaps with the claimed ranges of 68-74 wt% SiO2, 4-10 wt% Al2O3, 8-12 wt% Li2O, 0.1-3 wt% Na2O, and 0.1-1 wt% K2O ([0009]-[0038]). Beall teaches the glass plate can be made by known forming processes including rolling ([0176]), but doesn’t specify prerequisite steps for forming the melt or a casting step. Liang also teaches a similar method for forming a crystalline glass material comprising mixing glass raw materials including 65-70 wt% SiO2, 3-10 wt% Al2O3, 10-14 wt% Li2O, 1.5-4 wt% Na2O, 1-2 wt% K2O, and 1.5-4 wt% P2O5 (abstract, 3rd passage on page 4), which overlaps with the claimed ranges of 68-74 wt% SiO2, 4-10 wt% Al2O3, 8-12 wt% Li2O, 0.1-3 wt% Na2O, and 0.1-1 wt% K2O, to produce a glass mixture (abstract, 3rd passage on page 4), putting the mixture in a platinum crucible, heating the mixture in an electric furnace to uniformly melt the mixture, forming a basic glass with a cast ingot cutting method (paragraph bridging pages 5-6), and thermally treating the obtained basic glass in order to conduct nucleation and crystal growth, thereby preparing the crystalline glass material (2nd passage on page 6). Accordingly, it would have been obvious to one of ordinary skill in the art at the time of the invention to have employed the basic method steps comprising mixing, melting, casting, and cutting, as suggested by Liang, in order to provide for the basic glass for rolling into the glass plate of Beall, as such steps are well known methods steps for preparing a basic glass suitable for crystallization.
Liang teaches the melting step is combined with a homogenizing step, wherein the glass is gradually heated to a temperature of 1500-1560°C, but doesn’t specify a specify melting temperature. Yuan similarly teaches a method for preparing a crystalline glass material comprising mixing glass raw materials to produce a glass mixture, putting the mixture in a platinum crucible, heating the mixture in an electric furnace at a temperature in the range of 1250-1650°C, which overlaps with the claimed range of 1250°C to 1450°C, for 5-24 hours, which overlaps with the claimed range of 10-30 hours, to uniformly melt the mixture (“generating…” paragraph on page 14). Yuan further teaches forming a basic glass plate with an ingot casting method, and thermally treating the obtained basic glass in order to conduct nucleation and crystal growth, thereby preparing the crystalline glass material (bottom half of page 14). Yuan also teaches it would be obvious to use other well-known methods for forming the glass material (4th passage from bottom of page 14). Accordingly, it would have been obvious to one of ordinary skill in the art at the time of the invention to have tried a temperature in the range of 1250-1650°C for heating of the glass mixture, and for a period of time in the range of 5-24 hours, as Yuan teaches these ranges predictably provides for successful uniform melting of the glass mixture to be used for preparing crystalline glass material. Furthermore, as mentioned by Yuan, other well-known methods for forming the glass material can be utilized and suggests rolling (5th passage on page 14). Beall also suggests forming processes for producing the glass plate includes rolling.
While Beall and Liang further suggests a glass composition comprising 2-4 wt% ZrO2 ([0038]), or 1.5- 5 wt% ZrO2 (abstract), respectively, which falls within the claimed range of 1-6% ZrO2, both fail to suggest a P2O5 content of 9 wt% and a Eu2O3, content in the range of 0.2-2 wt %. Brodkin et al. teaches a crystallizable glass composition comprising 62-85 wt% SiO2, 5.1-10 wt% Al2O3, 8-19 wt% Li2O, 0-5 wt% Na2O, 0-7 wt% K2O, and 0.5-12 wt% P2O5, which overlaps with the claimed ranges of 68-74 wt% SiO2, 4-10 wt% Al2O3, 8-12 wt% Li2O, 0.1-3 wt% Na2O, 0.1-1 wt% K2O, and 9 wt% P2O5 (see range 3 in Table 1 on page 6). Brodkin also teaches the glass composition can further comprise of 0-3 wt% ZrO2 and 0-1 wt% Eu2O3, which overlaps with the claimed range of 1-6 wt% ZrO2 and 0.2-2 wt% Eu2O3. Brodkin teaches such compositions are melted at a temperature in the range of 1300°C-1400°C, which falls within the claimed ranged of 1250°C -1450°C, cast (page 3, lines 25-30), and heat treated to effect nucleation and crystal growth (top paragraph on page 4). Accordingly, it would have been obvious to one of ordinary skill in the art to have tried the composition of Brodkin in the method of Beall, Liang and Yuan, for producing a crystallized glass, a Brodkin teaches processing the glass in a similar method steps and predictable success in producing a crystallized glass.
Regarding claim 7, Beall further teaches conducting ion strengthening of the prepared glass material by soaking the glass material in molten salt baths. Beall teaches the ion exchange can be performed by employing various combinations of salt bath including multiple baths of different compositions ([0186]), and suggests soaking in a NaNO3 molten salt bath for 5-16 hours at a temperature of about 430°C ([0186], [0201], [0204]), which falls within the claimed range of 420-460°C, and soaking the glass material in a KNO3 molten salt bath for about 2-16 hours at a temperature of about 410°C ([0186], [0203]), which falls within the claimed range of 400-460°C. Yuan similarly teaches conducting ion exchange on the glass material by soaking the glass material in a NaNO3 molten salt bath for 8-13 hours, at a temperature of about 430°C, and soaking the glass material in a KNO3 molten salt bath for about 2-4 hours at a temperature of about 400-450°C (passage bridging pages 15-16). Although the specific combination of a first ion exchange step in a NaNO3 bath, followed by a second ion exchange in a KNO3 bath is not specified, it would have been obvious to one of ordinary skill in the art at the time of the invention to have tried the combination, as both Beall and Yuan teaches using multiple salt baths having different compositions.
Regarding claim 9, Beall teaches the thermal treatment comprises keeping the basic glass plate for 0.25-4 hours, which overlaps with the claimed range of 2-6 hours, at a temperature of 600°C, which falls within the claimed range of 600-650°C, and then for 0.25-4 hours, which overlaps with the claimed range of 2-10 hours, at a temperature of 630-730°C, which overlaps with the claimed range of 690-770°C ([0188]).
Response to Arguments
Applicant’s arguments, filed July 7, 2025, with respect to the rejection(s) of claim 1 under Beall, Liang, Yuan and Brodkin have been fully considered but they are not persuasive. Applicant argues Beall and Liang are different from the claimed invention in that the P2O5 content is not 9% and the crystal phases are different. Applicant also argues the P2O5 content of Brodkin is broad with no specific examples that approaches the 9% threshold, and like Beall and Liang, produces different crystal phases from that of the claimed invention. Specifically, applicant argues the main crystalline phase is a lithium salt crystalline phase, while the claimed invention produces not only a lithium salt crystal phase(s), but also an aluminum phosphate/metaphosphate crystalline phase. Furthermore, applicant argues modification with Bordkin would result in a product with a different optical performance. In response to applicant's argument that the references fail to show certain features of the invention, it is noted that the features upon which applicant relies (i.e., different crystalline phases and optical performance) are not recited in the rejected claims. Although the claims are interpreted in light of the specification, limitations from the specification are not read into the claims. See In re Van Geuns, 988 F.2d 1181, 26 USPQ2d 1057 (Fed. Cir. 1993).
Conclusion
THIS ACTION IS MADE FINAL. 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.
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/QUEENIE S DEHGHAN/Primary Examiner, Art Unit 1741