¶156 CCPA
¶2Donald R. Johnson, Philadelphia, Pa., for appellants.
¶3Joseph Schimmel, Washington, D. C. (Jack E. Armore, Washington, D. C., of counsel), for the Commissioner of Patents.
¶4Before WORLEY, Chief Judge, and RICH, ALMOND and BALDWIN, Judges.
¶6The issue here is whether the Board of Appeals committed reversible error in sustaining the examiner’s rejection of claims 2-4, 6-10, 12-16, 18, 20 and 22-26 1 as unpatentable in view of certain prior art under 35 U.S.C. § 103.
¶7It appears from the record that it was known to prepare aromatic carboxylic acids from alkyl-substituted aromatic compounds in a liquid phase oxidation process employing nitrogen dioxide (N02) as the oxidizing agent to convert the alkyl group to a carboxylic acid group. In that prior art process, N02 is itself converted or reduced to nitric oxide (NO), and the latter gas, after leaving the reaction vessel and removal of water vapor therefrom, is reacted with oxygen in a separate regenerating chamber to again form N02 which is then recycled to the alkyl aromatic oxidation process.
¶8Rather than synthesizing or regenerating the N02 oxidizing gas ex situ — outside the alkyl aromatic oxidation zone— as in the prior art, appellants feed a mixture of NO and oxygen directly into the alkyl aromatic oxidation zone, forming the desired N02 in situ, as reflected in claim 22:
22. In a process wherein alkyl substituted aromatic compounds are oxidized with nitrogen dioxide in the presence of an inert organic solvent to form the oxidation products thereof, the improvement which comprises generating said nitrogen dioxide in situ by charging nitric oxide and oxygen to the reaction zone.
¶9The NO effluent gas may be recovered and, after mixing with oxygen, is recycled directly to the alkyl aromatic oxidation zone. According to the specification, “it is necessary that small increments of NO or N02 be continuously introduced into the closed system” to the extent any NO gas is lost in such a continuous recycling system.
¶10*1080The board agreed with the examiner’s application of the Fetterly,2 O’Neill 3 and Gilman4 *references to the claimed subject matter. After pointing out (1) the various reactions expressly employed by Fetterly and O’Neill to generate N02 both in situ and ex situ in their oxidation processes, as heretofore noted, and (2) the knowledge in the art that NO and oxygen react to produce N02,5 the board considered it “clearly obvious to the chemist to employ … [the latter] reaction for the liberation of nitrogen dioxide in situ” during the oxidation of the alkyl aromatic compound.
¶11We think the Patent Office has established a prima facie case of obviousness which appellants’ arguments, unsupported by evidence in the record as they are,6 are insufficient to rebut. It seems to us that the prior art of record, rather than leading away from the claimed subject matter as appellants contends, would suggest the process here claimed to one of ordinary skill. Certainly, no reference of record deprecates the use of NO and oxygen mixtures as a feedstock to form N02 under the reaction conditions present in the alkyl aromatic oxidation zone. Nor is there any evidence of record which would give those in the art cause to believe that, as appellants urge, the reaction between NO and oxygen would not take place at sufficient rate and in sufficient amount to form the requisite quantity of N02 needed to effect oxidation under the reaction conditions present in the alkyl aromatic oxidation zone. While we appreciate appellants’ arguments, we are not convinced the subject matter as a whole is unobvious.
¶12The decision is affirmed.
¶13Affirmed.