hered to on reconsideration, affirming the examiner’s rejection of the sole claim in appellants’ application, serial No. 536,-618, filed March 23, 1966, for obviousness under 35 U.S.C. § 103. We affirm.
The Subject Matter Claimed
The claim on appeal is for the compound “Di-secondary-butylperoxydicar-bonate,” which we shall refer to as SBP. The application teaches that this ester is useful as an initiator of polymerization reactions of olefinically unsaturated monomers such as styrene, vinyl chloride, and ethylene. It further teaches that SBP is allegedly less susceptible to spontaneous decomposition and is less shock sensitive than prior art lower alkyl per-oxydicarbonate esters useful for the same purpose.
The References
The references are:
Strain 2,370,588 Feb. 27, 1945
Friedlander 2,728,756 Dec. 27, 1955
Strain et al.. Journal American Chemical Society, Vol. 72 (1950), pages 1254-1263
There is essentially no dispute about the teachings of the references. Appellants succinctly sum up the prior art as follows:
The cited references disclose three isomers and an adjacent homologue of the claimed compound, and disclose that these compounds have utility as polymerization initiators. The particular isomers disclosed are N-butyl peroxydicarbonate, isobutylperoxydi-carbonate, and tertiary butylperoxydi-carbonate, referred to as NBP, IBP and TBP respectively. The adjacent homologue disclosed is isopropyl per-oxydicarbonate (IPP).
The Strain reference discusses methods of producing peroxydicar-bonates, and discloses methyl ethyl carbinol * as a possible starting material. This compound, if reacted in the manner disclosed in the Strain reference, would result in the instantly claimed compound.
The Rejection
The examiner held and the board agreed that the claimed compound, SBP, would have been obvious to one of ordinary skill in the art in view of the close structural similarity of SBP to several prior art compounds, also known to be polymerization initiators, the board specifically referring to the teaching of Strain “indicating how the claimed compound may be made, and the disclosure of closely related specific isomeric compounds
Appellants filed two successive affidavits in an attempt to show unexpected superiority of SBP over the prior art isomers and homologue (NBP, IBP, TBP, and IPP) as polymerization initiators, with greater solubility in hydrocarbon solvents, greater safety in handling due to greater stability at room temperature, and less shock sensitivity. The second affidavit also included evidence of alleged commercial success of appellants’ compound under the trade name “Lupersol.”
The examiner was not impressed with appellants’ evidence because, as he said,
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it is noted that the instant compound is superior to some of its isomers in some respects, and inferior to some of its isomers in other respects. Further, data on only a few of a large number of possible tests are presented, e. g. the efficiency of the various peroxides with respect to dozens of other polymerizations could be determined. Moreover, variations in the characteristics of the isomers are reasonably to be expected in view of the teachings of Strain et al that differences in stability are dependent upon choice of alkyl groups *. Thus one skilled in the art would expect variations in properties among the various butyl isomers because of their structural differences.
The board adopted the above examiner’s reasons and, in addition, stated, with