Appeal No. 2006-1631
Application No. 10/317,759
of which rely on the U.S. Patent No. 6,558,814 to Spitsberg et
al. (Spitsberg) as a primary reference (Answer, pages 3 and 4).
A pivotal issue on this appeal relates to the rejection of
claim 35 under 35 U.S.C. § 103(a) over Spitsberg alone. Claim
35 specifically recites that the outer layer of a thermal
barrier coating comprises “from about 40 to about 60% of a
CMAS-reactive material to protect the thermal barrier coating at
least partially against CMAS that becomes deposited on the
exposed surface” (Claim 35). CMAS stands for calcium-magnesium-
aluminum-silicon oxide system (Specification, page 3).
According to the specification, “[a]ll amounts, parts, ratios
and percentages used herein are by weight unless otherwise
specified” (Specification, page 8). Thus, we interpret the
percentages in claim 35 as weight percentages.
One of appellants’ preferred CMAS-reactive materials is
barium strontium aluminosilicate (BSAS) (Brief, page 6).
Spitsberg discloses the use of BSAS particles 26 as a component
of an outer layer 22 of a thermal barrier coating 18 (col. 5,
lines 41-51). Spitsberg also teaches that the particles 26
“preferably constitute at least 5 volume percent of...layer
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