DETAILED ACTION
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
Claims 1-26 are rejected under 35 U.S.C. 112(b) as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor, regards as the invention. Claims 1 and 26 state that the wt% of Al2O3 may be 2-10% and that the wt% of Li2O may be 8-15%, but also state that the ratio of Li2O to Al2O3 is 2-4. These ranges are contradictory, as it would be impossible for the amount of Al2O3 to be as high as 10% while maintaining the claimed ratio of 2-4 if the Li2O is limited to as high as 15%. Claims 1 and 26 likewise state that the wt% of ZrO2 may be 5-15% but also state that the ratio of Li2O to ZrO2 is 1.2-1.7, but it would be impossible to meet the ratio limitation if the content of ZrO2 was as high as 15%. Claims 2-25 are rejected due to their dependency from claim 1.
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 1-16, 21-22, and 24-26 are rejected under 35 U.S.C. 103 as being unpatentable over Christensen et al., US 2021/0024406 A1, in view of Nakamura et al., US 2022/0371945 A1.
Regarding claims 1, 9-12, and 26, Christensen teaches a glass-ceramic comprising, by weight, 55-80% SiO2 ([0167]), 2-20% Al2O3 ([0169]), 7-15% Li2O ([0170]), 2-4% P2O5, and 0.2-15% ZrO2. Christensen teaches that the glass ceramic may have a phase assemblage comprising a crystalline phase and a residual amorphous phase ([0015]-[0016]). Although Christensen does not teach a specific ratio of Li2O to Al2O3 or Li2O to ZrO2, the claimed ratios overlap in scope with the expected ratios if one were to follow the teachings of Christensen regarding the content of Li2O, Al2O3, and ZrO2. Note that when a claimed range overlaps with or lies inside a range disclosed by the prior art, a prima face case of obviousness exists (MPEP 2144.05 I).
The teachings of Christensen differ from the present invention in that Christensen is silent as to the amount of CaO in the glass ceramic. Nakamura, however, teaches that such glass compositions may comprise CaO in an amount of 0.1-10 wt% in order to improve the meltability and reduce viscosity of the glass upon melting ([0098]). It would have been obvious to one of ordinary skill in the art to include CaO in an amount of 0.1-10 wt% in the composition of Christensen because doing so would improve the meltability and viscosity of the glass.
Regarding claims 2-5, although Christensen does not teach a specific ratio of Li2O to Al2O3, Li2O to ZrO2, or Al2O3 to ZrO2, the claimed ratios overlap in scope with the expected ratios if one were to follow the teachings of Christensen regarding the content of Li2O, Al2O3, and ZrO2. Note that when a claimed range overlaps with or lies inside a range disclosed by the prior art, a prima face case of obviousness exists (MPEP 2144.05 I).
Regarding claims 6 and 7, Christensen teaches a Na2O and K2O content of 0-2 wt% ([0171]).
Regarding claim 8, Christensen teaches a HfO2 content of 0-3 wt% ([0188]).
Regarding claims 13 and 25, Christensen teaches that the glass may comprise a lithium disilicate crystalline phase, a petalite crystalline phase, and a residual amorphous phase ([0008], [0016]).
Regarding claim 14, Christensen teaches that the residual amorphous phase may constitute 25 wt% of less ([0016]).
Regarding claims 15 and 16, Christensen teaches that the petalite phase may constitute 20-45 wt% ([0163]) and the lithium disilicate may constitute 35-50 wt% ([0164]).
Regarding claim 21, Christensen teaches a transmittance of greater than 90% for a thickness of 1 mm ([0066]), which would necessarily result in a transmittance of greater than 90% for a thickness of 0.5 mm.
Regarding claim 22, Christensen teaches a fracture toughness of 0.5-1.5 MPa m1/2 for the primary glass phase and 1.5 to 2.5 MPa m1/2 for the secondary phase, ([0072]-[0073]), both of which overlap with the claimed range.
Regarding claim 24, Christensen teaches an electronic device comprising a cover substrate made from the glass composition ([0017]).
Claims 17-20 and 23 are rejected under 35 U.S.C. 103 as being unpatentable over Christensen et al., US 2021/0024406 A1, in view of Nakamura et al., US 2022/0371945 A1 as applied above, and further in view of Guo, US 2021/0403368.
Regarding claim 17, Christensen teaches a compressive stress layer extending from the surface to a depth of compression ([0191]). The teachings of Christen differ from the present invention in that Christen does not teach any specific value for the central tension (ie, does not teach 170 MPa or more). Nakamura, however, teaches a similar glass ceramic product, and teaches a central tension of 170 MPa or more in order to provide improved fracture resistance ([0018], [0091]). It would have been obvious to one of ordinary skill in the art to provide the glass of Christensen with a central tension of 170 MPa or higher, because doing so would provide the product with improved fracture resistance.
Regarding claim 18, Nakamura teaches a compressive stress of 500 MPa or more ([0024], Claim 6).
Regarding claim 19, Christensen teaches that the glass may be strengthened via ion exchange ([0056]).
Regarding claim 20, Nakamura teaches a depth of compression of 0.15t to 0.25t ([0093]).
Regarding claim 23, Nakamura teaches an elastic modulus of 80-100 GPa ([0045], [0080]).
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Ian A Rummel whose telephone number is (571)270-5692. The examiner can normally be reached Monday - Thursday and alternating Fridays, 8:30-5:00.
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/IAN A RUMMEL/ Primary Examiner, Art Unit 1785
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