In re Tashiro

LANE, Judge. This appeal is from the decision of the Board of Appeals affirming the rejection of claims 1, 2, 5, 6, and 9-17, all of the claims remaining in appellants’ application,1 as unpatentable under 35 U.S. C. § 103. The board also sustained the examiner’s rejection of claims 16 and 17 under 35 U.S.C. § 112. Although appellants assigned error in the board's af-firmance of the latter rejection, they do not press the issue before the court. In any event, we agree with the board’s conclusions on the § 1Q3 issue and affirm on that basis thereby rendering consideration of the § 112 issue unnecessary. The claims are directed to a thermally crystallizable glass composition, the [654] method of thermally converting the composition to a crystalline ceramic article, and the shaped article so produced. The composition may be described as an Na2 0 (sodium monoxide)-Al2 O3 (alumina)-Si02 (silica)-BaO (baria) system (sodium glass system) which includes Ti02 (titania) and Zr02 (zirconia) as nucleating agents, i. e., crystallization-promoting materials. The proportions of each constituent are set forth in the claims. The controversy centers principally about the obviousness of utilizing a mixture of titania and zirconia in the defined proportions as nucleating agents in the claimed sodium glass system. Claim 1 is illustrative of the composition claims on appeal and reads as follows: 1. A thermally crystallizable glass having a composition consisting essentially of a) a base glass formulation of which more than 95 percent by weight consists of the following components present in the following weight percentages: Si02 45-57 Al2 Os 29-38 Na2 O 13-22 and b) the following components present in the following weight percentages, based on said Si02 + Al2 ■+ Na2 0 as being 100% by weight: BaO 2-14 Ti02 1- 3 Zr02 1-4 It is to be noted that appellants calculate the baria, titania and zirconia proportions on the basis of 100% Si02 -|- Al2 03 + Na2 O. Since in the prior art discussed below computation of component proportions assumes that 100%-equals the sum of the contributions of all components, adjustments must be made to place the disclosures on a comparative ground. Claim 2 depends from claim 1 and indicates the presence of at least one other oxide in the base glass formulation recited in the first claim. Claim 16 defines narrower ranges for the constituents of the overall composition and includes optional oxides. Claims 10 through 15 set forth, with varying specificity, the method of crystallizing and shaping the glass composition defined in claim 1. Claims 5, 6 and 17 are drawn to shaped crystalline articles formed from the compositions of claims 1, 2 and 16 respectively, and claim 9 specifies the bending strength of the article of claim 17. The rejection was based upon MaeDow-ell2 in view of Tashiro et al. (Tashiro) 3 and Meyer.4 References of record upon which appellants rely in asserting nonob-viousness are Kivlighn,5 Stookey,6 and Megles.7 MacDowell discloses a thermally crys-tallizable glass composition comprising 10-20% Na2 O, 28-38% Al2 03, 30-55% Si02, and 1-20% BaO, and in which 5-12% Ti02 is used as nucleating agent. The board found that the composition used in MacDowell’s Run No. 1, Table I, contained about 16.6% Na2 O, 33.6% Al2 03, 49.7% Si02, and 4.1% BaO when the proportions are adjusted to appellants’ basis of calculation. The Na2 O, Al2 03, Si02 and BaO proportions fall within the 'ranges claimed by appellants, and Mae-Dowell therefore discloses appellants’ basic sodium monoxide-alumina-silica-baria system. [655] The claimed subject matter differs from MacDowell in that the Ti02 and Zr02 are used as nucleating agents rather than Ti02 alone. The board agreed with the examiner, however, that the substitution of the combination of nucleating agents in the claimed proportions for Ti02 alone would have been obvious from Tashiro and Meyer. Tashiro discloses a crystallizable lithium glass system based on Si02, Al2 O3 and Li2 0 (lithium monoxide). Whereas Ti02 in a 3-7% range was previously believed necessary for nueleation, Tashi-ro found that 1-3% Ti02 is suitable when used in conjunction with 1-4% Zr02. It is apparent that the end-points of the ranges would be slightly higher if computed on appellants’ basis, but the overlap would be substantial. There is no argument that the proportions of Ti02 and Zr02 disclosed in Tashiro are materially different from those claimed by appellants. Meyer discloses that contrary to prior belief, Zr02 is a better nucleating agent for crystallizable glasses than Ti02. The suggested proportion of Zr02 is 1-7%. Meyer teaches that up to 2% Ti02 can be used with the zirconia. The only specific glass systems disclosed in Meyer are lithium glasses. The board reasoned that both Tashiro and Meyer provide the suggestion for the substitution of a combination of zirconia and titania for titania in MacDowell. Appellants disagree noting especially that both Meyer and Tashiro are directed to nucleating agents for lithium glasses rather than the sodium glasses of Mac-Dowell and the present invention. Appellants also contend that other prior art of record tends to teach away from the proposed substitution and that the claimed proportions of zirconia and titania are not suggested by the references. OPINION We think the substitution of zirconia and titania for titania in MacDowell would have been prima facie obvious from Meyer and Tashiro. While as a general proposition secondary glass constituents may not always be expected to behave comparably in sodium and lithium glass systems, cf. In re Mochel, 470 F.2d 638, Patent Appeal No. 8768, decided December 29, 1972, in the present case, both Tashiro and Meyer teach the use of a combination of Zr02 and Ti02 as nucleating agents for the crystallization of thermally crystallizable glass systems. That is the same use of Ti02 as that disclosed in MacDowell. Tashiro especially suggests a prima facie equivalence of lithium and sodium glasses with respect to nueleation in disclosing that previously Ti02 was employed as the sole nucleating agent for lithium glasses. That disclosure comports with the MacDowell teaching of titania as the sole nucleating agent for sodium glasses. The improvement taught by Tashiro to flow from the addition of zirconia and accompanying reduction in the proportion of titania would be expected to follow as well with sodium glasses. Meyer reinforces this expectation. Although the examples in Meyer are limited to lithium glasses, the disclosure is broadly drawn to crystal-lizable glasses in general. We fail to see how the disclosures of the Kivlighn, Megles, and Stookey patents disturb the assumption upon which the prima facie case of obviousness is founded. Appellants contend that Kiv-lighn teaches away from the use of Ti02 as the sole nucleant for sodium glasses and that Stookey is to the same effect in teaching against the incorporation of large amounts of Na2 O when using Ti02 as the nucleating agent. Megles, on the other hand, does use titania to nucleate sodium glasses, but appellants characterize Megles as an exception to the general rule established by Kivlighn and Stookey and point to Megles’ critically narrow range of base glass system constituents.8 MacDowell, presumably, is another exception. [656] To the extent that Kivlighn and Stoo-key define a general proposition in the art to the effect that Ti02 is undesirable as a sole nucleating agent for sodium glasses, those two references would seem to support the obviousness of utilizing titania in conjunction with zirconia in lieu of titania alone. In view of the Megles and MacDowell teachings, however, a general rule is suspect. Apparently some workers in the art were convinced of the suitability of Ti02 alone. Appellants argue that both MacDowell and Megles find such suitability only because of the narrow and critical range of glass system components. If appellants are correct in their assessment of the Megles and MacDowell disclosures, then obviousness is strengthened rather than weakened since Tashiro and Meyer teach that the disadvantages attendant the use of titania alone can be overcome by the addition of zirconia. We conclude that whether the art recognized that titania could be used by itself in some cases or should not be used alone, Tashiro and Meyer suggest, in either case, the use of the combination of zirconia and titania in lieu of titania. Appellants finally argue that the claimed proportions of Ti02 and Zr02 would not have been obvious from the references relied upon. Appellants point out that the MacDowell proportion of titania is much higher than that presently claimed. However, we agree with the solicitor that the tenor of Tashiro and Meyer is that when utilizing the combination of zirconia and titania, the proportion of titania is reduced. A fairer comparison would be between (1) the total quantity of titania and zirconia components disclosed in Tashiro and Meyer and (2) the quantity of titania used by MacDowell. Tashiro discloses 1-3% Ti02 with 1-4% Zr02, or 2-7% total nucleant, and Meyer discloses 1-7% Zr02 with up to 2% Ti02, or 1-9% total nucleant. These figures do compare with the 5-12% range for Ti02 disclosed by MacDowell. Thus, the use of the Tashiro and Meyer ranges in the MacDowell composition would be obvious, and since the claimed composition includes substantially the same proportions of Ti02 and Zr02 as Tashiro, we,agree that the proportions are not a basis for patentable distinction of the claimed subject matter. Although appellants treat the method claims separately from.the composition and article claims, their arguments are directed to the particulars of the composition rather than of the method. The same contentions are presented as were rejected above. Accordingly, we agree with the board’s decision on the method claims as well. The decision of the board is affirmed. Affirmed. Footnotes [1] Serial No. 416,892 fi ed December 8, 1964. [2] U.S. Patent No. 3,201,266 issued August 17, 1965, on an application filed July 23, 1962. [3] U.S. Patent No. 3,282,712 issued November 1, 1966, on an application filed October 3, 1962. [4] German Patent No. 1,099,135 published February 9, 1961, an English translation of -which is of record. [5] U.S. Patent No. 3,146,114 issued August 25, 1964. [6] U.S. Patent No. 2,920,971 issued January 12, 1960. [7] U.S. Patent No. 3,313,609 issued April 11, 1967, on an application filed June 18, 1963. [8] Tlie solicitor contends that Megles cannot be relied upon to show nonobviousness since issued subsequent to appellants’ filing date, but could be relied upon to show [656] obviousness based on the Megles filing date by virtue of 35 U.S.C. § 102(e). Since we do not find that Megles tends to prove nonobviousness, we need not resolve this issue.