Appeal 2007-2916
Application 10/225,502
machine. As the composition is molded, the more
lubricious boron nitride tends to "wet-out" and
contacts the surface of the mold tooling. In
contrast, the more abrasive alumina tends to
remain in the center of the molding composition
and does not strike the surface of the molding tool.
Thus, the substantially non-abrasive compositions
of this invention can be molded into articles
without causing excessive wear and tear on the
mold tooling. [Specification.¶ 21.]
B. McCullough
[10] McCullough discloses moldable compositions having a thermal
conductivity above 22 W/mo K and comprising
30-60 % by volume of a polymer base matrix;
25-60% by volume of a relatively high (≥ 10:1) aspect ratio
filler; and,
10-25% by volume of a relatively low (≤ 5:1) aspect ratio filler
(McCullough, col. 2, ll. 21-30).
[11] The polymer base matrix material is preferably a liquid crystal
polymer (McCullough, col. 5, ll. 5-7).
[12] The high aspect ratio filler may be alumina (McCullough, col. 5, ll.
35-36).
[13] The low aspect ratio filler may be granular or spherical boron nitride
(McCullough, col. 3, ll. 51-53).
[14] McCullough does not disclose using a substantially hexagonal boron
nitride as the low aspect ratio filler.
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