Application of Wesley L. Archer

374 F.2d 1014, 54 C.C.P.A. 1242

• Court: Court of Customs and Patent Appeals
• Decided: April 6, 1967
• Docket: Patent Appeal 7777
• Status: Published

Opinion

ALMOND, Judge.

This is an appeal from the decision of the Board of Appeals affirming the prior art rejection of claims 1 to 4 of appellant’s application serial No. 135,720, filed September 5,1961, for “Polyphenyl Ether Stabilizer.” No claims have been allowed.

The invention relates to a high-pressure, high-temperature synthetic lubricant composition comprising a polyphenyl ether as the major lubricant and, as the essential antioxidant and viscosity improver, a compound selected from the group consisting of the cobalt salts of naphthenic, benzoic, and alkylbenzoic acids.

Claim 1 is illustrative and reads as follows:

1. A high-pressure, high-temperature lubricant composition comprising a polyphenyl ether as the major lubricant, said ether having the following generic formula: wherein n represents an integer from 2 to about 6, and, as the essential antioxidant and viscosity improver, from about 0.005 to about 0.5% by weight, based on the total composition, of a compound selected from the group consisting of the cobalt salts of naphthenic, benzoic and alkylbenzoic acids said alkyl radical having from 1 to 18 carbon atoms, inclusive.

The references relied on are:

Parker May 14, 1935 2,001,108

Prutton November 26, 1940 2,223,129

Diamond June 14, 1960 2,940,929

Bataafsche October 19, 1960 851,651

(British)

The earlier references, Parker and Prutton, primarily relate to the stabilization of hydrocarbon or petroleum lubricants. The later references, Diamond and Bataafsche, relate to stabilization of polyphenyl ether, a type of synthetic lubricant.

Parker states that his invention provides “a petroleum oil containing a metal-lie salt of a naturally occurring acid in quantity sufficient to stabilize the oil against deterioration caused by exposure of the oil to light and/or air without materially affecting the viscosity of the oil.” Parker’s specifically mentioned stabilizers are the naphthenic acid salts of eight metals, namely calcium, manga nese, lead, zinc, copper, cobalt, sodium, and potassium.

Prutton discloses lubricating compositions to which are added stabilizers “particularly effective in rendering the lubricants suitable for use under conditions of extreme stress as imposed by high temperatures, high loads, etc.” Prutton states that the base of his lubricating compositions “may consist either entirely or in part of synthetic oils * * The stabilizing additives of this reference are salts of aromatic acids. Among the many addition agents disclosed in the patent are the cobalt salts of benzoic acid and alkylated benzoic acids. As does Parker, Prutton discloses that the acid salts of several other metals, for example calcium and zinc, are also useful stabilizers of lubricating compositions.

Diamond discloses lubricating compositions useful “at elevated temperatures and under oxidizing conditions” comprising “a major proportion of polyphenyl ethers” and minor amounts of additives “sufficient to stabilize said ethers against oxidation at temperatures in excess of about 450° F., said additive material being basic and neutral indium salts of fatty acids, thiafatty acids, and of alkylated benzoic acids * *

Bataafsehe teaches the addition, “to polyphenyl ether compositions useful as synthetic lubricants,” of salts of aromatic carboxylic acids such as benzoic acid with metals from Group II of the Periodic Table, especially zinc and calcium, in order to “increase the oxidation and thermal stability of the compositions under high temperature conditions * *

The examiner rejected claims 1 to 4 as unpatentable over Diamond and Bataafsche in view of Prutton or Parker under 35 U.S.C. § 103. His position is stated to be that:

* * * it would involve no more than routine experimentation within the art to determine the applicability of cobalt salts of the instant acids for polyphenyl ether stabilization in view of the secondary references which disclose such salts as useful for the same purpose [stabilization] in other lubricating media. The substitution of the cobalt salts of Parker or Prutton for the various salts of the same acids disclosed by the primary references is thus deemed obvious and unpatentable.

In affirming the examiner’s decision, the board stated that “in spite of some distinctions between the two types of lubricants [hydrocarbon oils and polyphenyl ethers], the art nevertheless provides the suggestion for interchanging cobalt for calcium or zinc in these salts.”

Appellant’s argument here is principally based on two propositions, (1) that selection of the cobalt salts from the numerous additives disclosed in the secondary references to be effective stabilizers for petroleum lubricants is unobvious, and (2) that the primary references teach away from the use of petroleum lubricant additives as stabilizers for polyphenyl ether lubricants.

With regard to the first proposition, we note that Parker specifically lists only eight lubricant additives, including cobalt naphthenate. Also, appellant has neither alleged, nor offered any evidence to prove, that any or all of the other seven metal naphthenates of Parker, or for that matter any of the Prutton additives, is either inoperable as a stabilizer of polyphenyl ether lubricants, or even substantially less effective than cobalt naphthenate for that purpose. The conclusion which we think properly should be drawn from the references before us is that cobalt salts, disclosed to be useful stabilizers for petroleum lubricants, should reasonably be expected to be useful stabilizers for other types of lubricants, including polyphenyl ethers, in the absence of substantial evidence to the contrary.

While it may be true that effective stabilizers for petroleum or hydrocarbon lubricants are not necessarily effective stabilizers for synthetic lubricants such as polyphenyl ethers, we do not construe the general teachings to that effect of Diamond and Bataafsche to lead one away from the use of the cobalt salts of Parker and Prutton as stabilizing additives for polyphenyl ether lubricants. We think it would be obvious to substitute the cobalt salts of the secondary references for the stabilizing additives of the primary references. As the examiner pointed out in his answer before the board:

* * * an antioxidant in a lubricating system is preferentially oxidized so as to allow the base oil to remain free from the deleterious effects of oxidation and, thus, the medium [lubricant] in which such an inhibitor functions should not vary the effectiveness of the additive.

For the reasons stated above, the decision of the board is affirmed.

Affirmed.