Appeal No. 2006-1792
Application 10/329,665
create an ablative material for use in rocket motors” which is not the problem addressed by any
of Lyday, Brownell, Duryea, Nanaumi and Yasuma which would not have disclosed ablative
compositions (id., pages 12-13). With respect to claim 15, Appellants submit that the amount of
boric acid used in the admitted prior art composition would not have suggested the amount of
zinc borate to be used in such composition because of the difference in molecular weight of the
compounds (id., pages 14-15).
Appellants further submit that the claimed composition is disclosed in the written
description in the specification to provide “surprising results” with respect to slowing the
material aging rate and producing less water during the curing process which results in fewer
failures in material and may reduce unwanted voids in the material, respectively, and alleges that
these results are “unexpected” (reply brief, pages 8-9; see specification, [0072]-[0073]).
The Examiner maintains that one of ordinary skill in this art following the combined
teachings of Lyday, Brownell, Duryea, Nanaumi and Yasuma would have used zinc borate as a
flame retardant in plastic compositions (answer, page 8). The examiner finds that “in the art of
flame retardants, it was known that boric acid was a common flame retardant material associated
with cellulose products while zinc borate was a common flame retardant material associated with
plastics as evidenced by Lyday,” and Brownell, Duryea, Nanaumi and Yasuma would have
“suggested that zinc borate would have been added as a flame retardant’ to phenolic based
compositions (id., pages 8-9). On this basis, the examiner determines that one of ordinary skill
in the art would have used zinc borate in place of boric acid in the admitted prior art composition
because “zinc borates were commonly employed with phenolic resins (the main thermosetting
component of the mixture used for insulation) in the process of lining a rocket motor nozzle”
disclosed by Whelan and Russell (id., page 9). With respect to claim 15, the examiner
determines that the “specific amounts of [zinc borate] would have been determined by routine
experimentation (id., page 10). With respect to appellants’ arguments, the examiner contends
that one of ordinary skill in the art would have been motivated to substitute zinc borate for boric
acid because zinc borate was successfully used as a flame retardant in phenolic resin
compositions by Brownell, Duryea, Nanaumi and Yasuma, and thus would have reasonably
expected that the substitution of zinc borate for boric acid in the admitted prior art composition
would have been recognized as the interchange of two materials which are known to be
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