Appeal No. 2005-1469 Page 4
Application No. 10/463,751
Fujii does not disclose that the silica or silane is treated with a hydrophobic agent. The
Examiner found that Cohen teaches the use of silane surface treated silica in rubber
compositions, and CABOT teaches the silane surface treated silica. (Answer, p. 5).
The Examiner concluded that since Fujii teaches employing silica and silane coupling
agents and since the use of silane surface treated silica in a hydrophobic polymeric
matrix improves bonding of said polymeric matrix and silica (filler) is a routine practice in
the art, it would have been obvious to one skilled in the art at the time of invention to
utilize the art well known and commercially available silane surface treated silica taught
by Cohen or CABOT in the composition of Fujii. (Answer, p. 5).
All of the appealed independent claims, i.e., 1 and 15, require the filler silica
particles and filler silicate particles to be treated with at least one hydrophobic surface
agent. Appellants disclose in the specification that the rocket motor composition
containing filler particles that have been treated with a suitable hydrophobization agent,
exhibits reduced sensitivity to process variables such as moisture contamination and
relative humidity. (Specification, paragraph 0015). The specification further states, “the
elastomeric rocket motor insulator also exhibits improved mechanical properties (e.g.,
elongation capability and tensile strength) over conventional peroxide-cured polymers
containing hydrophilic silica particles. This finding of improved mechanical properties
was surprising and unexpected because hydrophobic silica particles evaluated by the
inventors generally were believed to contribute less reinforcing characteristics to an
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