Appeal No. 2000-0019
Application 08/977,451
coated microspheres. In discussing the function of the chain scission agent, it is stated
that:
…the use of a small amount of peroxide [a chain scission agent] and maleic
anhydride [a functionalizing agent] causes substantial changes in the properties
of the composite material. Tensile strength is substantially enhanced whilst a
Melt Flow Index suitable for pipe extrusion is maintained. Adhesion between
microspheres and polymer is believed to be improved thereby increasing creep
resistance
(Page 8, lines 34-37).
We agree that it would have been obvious to one of ordinary skill in the art, at the
time the invention was made, to have utilized the uncoated microspheres of Coleman in
the polymer of Marzola.
The crux of the issue is whether the negative portions of the teachings found at
Coleman, page 2, lines 23 – 31 and page 5, lines 51- page 6, line 3 are sufficient to
overcome the remainder of the teachings in the references, such that the prima facie
case of obviousness cannot stand.
The Appellants state that “[o]ne of ordinary skill in the art would have no
motivation to ignore this teaching [the negative teachings of uncoated microspheres] by
adding untreated microspheres to a polyolefin regardless of whether it contains polar
groups. Instead, one of ordinary skill in the art would understand from Europe ‘215
[Coleman] that the chain scission agent permits accurate control of mechanical
properties such as yield strength, extensibility to break and creep resistance” (Reply
Brief, page 6, lines 2-8). The Appellants further state that one of ordinary skill in the art
would have no reasonable expectation of success in making the claimed composition,
relying on Coleman’s negative teachings.
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