Application of Carleton

• Decision Date: 07 June 1979
• Docket Number: No. 78-634.,78-634.
• Citation: 599 F.2d 1021
• Parties: In the Matter of the Application of Peter S. CARLETON.
• Court: U.S. Court of Customs and Patent Appeals (CCPA)

599 F.2d 1021

In the Matter of the Application of Peter S. CARLETON.

No. 78-634.

United States Court of Customs and Patent Appeals.

June 7, 1979.

Roman Saliwanchik, Kalamazoo, Mich., attorney of record, for appellant; Denis A. Firth, North Haven, Conn., John Kekich, Kalamazoo, Mich., of counsel.

Joseph F. Nakamura, Washington, D.C., for the Commissioner of Patents; Fred W. Sherling, Washington, D.C., of counsel.

Before MARKEY, Chief Judge, RICH, BALDWIN, MILLER and KUNZIG,^* Judges.

MILLER, Judge.

This is an appeal from the decision of the Patent and Trademark Office ("PTO") Board of Appeals ("board") sustaining the rejection under 35 U.S.C. § 103 of claims 9-13 and 15-16. We reverse.

BACKGROUND

The Invention

Appellant's application¹ discloses a process for the substantially quantitative production of hydroquinone. Claims 9-10 and 15² are directed to the reaction of p-isopropenylphenol and hydrogen peroxide in an inert solvent such as glacial acetic acid and in the presence of a catalytic amount of a strong mineral acid to produce hydroquinone and acetone (see reaction step (3) below). Claims 11-13 and 16³ are directed to the semicontinuous production of hydroquinone through the production of p-isopropenylphenol from phenol and acetone, according to the following reaction sequence:

The Rejections and Appellant's Response

The examiner rejected claims 9-10 and 15 as unpatentable over a patent to Robert H. Saunders ("Saunders"),⁴ which discloses a process for the preparation of various phenols from , -unsaturated alkyl-substituted aryl⁵ compounds. Hydroquinone is a phenol.⁶ His reaction occurs in a liquid solvent, such as acetic acid, with a strong acid catalyst and, preferably, with "low cost" hydrogen peroxide as the oxidizing agent. In example 2, -methylstyrene, which the examiner said is the closest in structure to the starting material of appellant's claimed invention (p-isopropenylphenol), is reacted with t-butylhydroperoxide to produce phenol in about an 80% yield:

Although the production of hydroquinone as such is mentioned by Saunders, the only suggested process begins with , , ', '-tetramethyl-p-xylylene dialcohol as the starting material.⁷

The examiner's rejection of claims 11-13 and 16 was based on Saunders in view of a patent to John L. Jones ("Jones").⁸ Jones was cited for the disclosure of a method for the preparation of phenols having unsaturated substituents (such as p-isopropenylphenol — the starting material of claims 9-10 and 15) via a two-step reaction. In the first step, a phenol is condensed in the presence of an acid catalyst with a ketone to produce an intermediate "condensation product," which is then treated with a strong alkali metal base to neutralize the acidic catalyst. The mixture undergoes pyrolysis producing the desired phenolic compound (with an unsubstituted side chain), phenol, and a polymeric residue. On appeal, appellant has not argued that the first two steps of his reaction sequence, in which p-isopropenylphenol is produced, would not have been obvious in light of the PTO's citation to Jones.

In response to the rejections, appellant submitted several affidavits (including two by him) under 37 CFR 1.132. One by Sheng-Hong A. Dai described two tests. In the first test ("Dai I"), the procedure of example 2 of the Saunders patent was followed "exactly"⁹ (the starting material being -methylstyrene), except that hydrogen peroxide (instead of t-butylhydroperoxide) was used as the oxidizing agent. A yield of only 15.8% phenol was reported; the major product was believed to be dimers of the -methylstyrene.¹⁰ In the second test ("Dai II"), the "exact" reaction conditions of example 2 of Saunders were followed except that p-isopropenylphenol (the starting material of appellant's process) was used. A yield of only 47% hydroquinone was obtained.

Appellant also directed the examiner's attention to a published German application,¹¹ which discloses a process for the production of hydroquinone from 1,4-diisopropenylbenzene¹² in the presence of glacial acetic acid as the solvent, either mineral acids or Friedel-Crafts type compounds as the catalyst, and hydrogen peroxide as the oxidizing agent. The pertinent examples indicate yields of hydroquinone of about 10-35%.¹³

The Decision Below

The board found that the cited references "make out a strong case of prima facie obviousness" against appellant's claims, because (1) the starting material of the claimed process is encompassed in Saunders' generic starting materials; (2) the oxidizing agent in the claimed process (hydrogen peroxide) is stated by Saunders to be the preferred peroxide (due to its low cost); and (3) Saunders and Jones disclose all of the other reaction conditions. It further found that the disclosure of hydroquinone production by the Saunders process, "albeit from a different starting material than the one recited in appellant's claims, would lead one of ordinary skill to expect that the presence of the first formed hydroxyl group on the benzene ring would not interfere with the process of forming the second hydroxyl group." The board said the affidavit evidence was unpersuasive and concluded that the Carleton I and II affidavits failed to follow the prior art closely enough. It particularly criticized the concentration of the reactants and catalysts and the short reaction times.

On reconsideration, the board adhered to its original decision, saying that the affidavits merely indicate that it is possible to operate within the teachings of Saunders without obtaining a good yield. It also said that the Dai II result conflicts with the result in example 9 of appellant's specification, illustrating that there can be considerable variation in yield from "minor modification in reaction conditions."

OPINION

We do not agree with the board's characterization of the showing made by the examiner as a "strong" prima facie case. In a 35 U.S.C. § 103 case, the burden of proof is on the PTO to establish a prima facie case of obviousness, In re Warner, 379 F.2d 1011, 54 CCPA 1628, 154 USPQ 173 (1967), cert. denied, 389 U.S. 1057, 88 S.Ct. 1201, 20 L.Ed.2d 101 (1968), and, once this has been accomplished, the burden of going forward with evidence to rebut that prima facie case is shifted to the applicant. In re Murch, 464 F.2d 1051, 59 CCPA 1277, 175 USPQ 89 (1972); In re Hyson, 453 F.2d 764, 59 CCPA 782, 172 USPQ 399 (1972). Whether a prima facie case is "strong" or "weak" is not material. If the applicant presents rebuttal evidence, the decisionmaker must consider all of the evidence of record (both that supporting and that rebutting the prima facie case) in determining whether the subject matter as a whole would have been obvious.¹⁴In re Rinehart, 531 F.2d 1048, 189 USPQ 143 (Cust. & Pat.App.1976); In re Lewis, 443 F.2d 389, 58 CCPA 1270, 170 USPQ 84 (CCPA 1971). The correct procedure for considering rebuttal evidence was set forth by this court in In re Rinehart, supra, 189 USPQ at 147, 531 F.2d at 1052:

Though the burden of going forward to rebut the prima facie case remains with the applicant, the question of whether that burden has been successfully carried requires that the entire path to decision be retraced. An earlier decision should not, as it was here, be considered as set in concrete, and applicant's rebuttal evidence then be evaluated only on its knockdown ability. Analytical fixation on an earlier decision can tend to provide that decision with an undeservedly broadened umbrella effect. Prima facie obviousness is a legal conclusion, not a fact. Facts established by rebuttal evidence must be evaluated along with the facts on which the earlier conclusion was reached, not against the conclusion itself. Though the tribunal must begin anew, a final finding of obviousness may of course be reached, but such finding will rest upon evaluation of all facts in evidence, uninfluenced by any earlier conclusion reached by an earlier board upon a different record.

The similarities between the processes of Saunders and those of appellant are evident, the only significant differences alleged by appellant being: (1) the starting material (Saunders uses -methylstyrene, whereas appellant uses p-isopropenylphenol),¹⁵ and (2) the oxidizing agent (Saunders uses t-butylhydroperoxide, whereas appellant uses hydrogen peroxide).

Regarding (1), the board noted that the generic description of Saunders' starting materials (" , -unsaturated alkyl-substituted aryl compounds") encompasses appellant's starting material since the term "aryl" includes the phenyl radical. Assuming that a hydroxyl group on the benzene ring of Saunders' starting material (which is the only difference between the starting material used by appellant and that used by Saunders) would not interfere with the reaction process disclosed by Saunders, the board said that it would have been obvious to make hydroquinone (which differs from phenol only in the hydroxyl group at the para-position) from a starting material such as that used by Saunders, in which a hydroxyl group¹⁶ is attached at the para-position.

Regarding (2), the board noted that, although example 2 of Saunders uses t-butylhydroperoxide as the oxidizing agent, Saunders makes the general observation that hydrogen peroxide is the preferred oxidizing agent "due to its low cost." It concluded, therefore, that it would have been obvious to one skilled in the art to use hydrogen peroxide as the oxidizing agent in appellant's process. In view of the foregoing, we are persuaded that the board properly found that the prior art cited by the examiner established a prima facie case of obviousness.¹⁷ However, we are also persuaded that the board erred in failing to give proper weight to appellant's rebuttal affidavits, which directly attacked the premises on which the board based its determination of obviousness. Cf. In re Lewis, supra.

The only difference between Dai II and example 2 of Saunders is the...