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.
Claim 6 is 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.
Claim 6 specifies a glass transition temperature of an uncrystallized glass prior to crystallization, but claim 1 (from which claim 6 depends) is directed to a crystalized glass. Claim 6 thus appears to be directed to a precursor product to claim 1, rather than the product of 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 1-6 are rejected under 35 U.S.C. 103 as being unpatentable over Fan et al., US 2021/0230049 A1, in view of Murphy, US Pat. 3778338.
Regarding claims 1-5, Fan teaches a strengthened glass ceramic that may be cristobalite (Abstract, [0043]) comprising (by mass%) 40-85% SiO2, 0-15% Li2O, 0-40% Al2O3, 0-15% B2O3, and 0-15% P2O5 ([0044]), as well as numerous other exemplary compositions that overlap in scope with the claimed ranges ([0063]-[0073]). Note that when a claimed range overlaps with or lies inside a range disclosed by the prior art, a prima facie case of obviousness exits (MPEP 21440.5 I). Note also that although Fan does not explicitly state that the cristobalite is alpha phase, the cristobalite of Fan is expected to be alpha phase because alpha cristobalite predominates over other cristobalite phases at room temperature.
The teachings of Fan differ from the present invention in that although Fan teaches that the product may be chemically strengthened to introduce a compressive stress layer and a central tensile stress ([0090]-[0092]) and teaches that the compressive stress level should not be too high so as to avoid unwanted self-breakage ([0096]), Fan does not teach any specific ratio of compressive stress to central tensile stress (ie, does not teach a ratio of 1.64 – 2.5). Murphy, however, teaches that an appropriate ratio of compressive stress to central tension in a glass product is 2-4 (col 1 ln. 46-50). It would have been obvious to one of ordinary skill in the art to provide the glass ceramic of Fan with a compressive stress/central tension ratio of 2-4 because Murphy explicitly teaches such a ratio to be appropriate for a glass article.
Regarding claim 6, the claim is indefinite for the reasons discussed above. The claimed limitations related to the properties of an uncrystallized precursor glass cannot distinguish the claimed invention because claim 1 is directed to a crystalized cristobalite glass product. Nevertheless, Fan teaches a glass composition that overlaps in scope with that which Applicant’s specification teaches to produce a glass with the claimed glass transition temperature.
Conclusion
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IAN A. RUMMEL
Examiner
Art Unit 1785
/IAN A RUMMEL/Primary Examiner, Art Unit 1785
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