Appeal No. 1999-1415
Application 08/784,875
process for preparing polyisocyanates disclosed by Tate, the primary reference in the ground of
rejection, vis-à-vis the claimed process for preparing polyisocyanates encompassed by
representative appealed claim 1. In comparing Comparative Example 5 with appealed claim 1
and Tate, the benzyl substituted ammonium hydroxide catalyst used in the comparative example
falls within the catalysts specified in claim 1 and is disclosed by Tate (page 3, lines 10-11), while
the hexamethylene diisocyanate (HDI) used in the comparative example contains 38 ppm by
weight of carbon dioxide which is outside of the claimed range of less than 10 ppm by weight. In
this latter respect, Tate discloses the use of HDI per se (page 3, line 22), which we determine
would have led one of ordinary skill in this art to use known commercial or technical grade HDI
that, on this record, contain more than 20 or more ppm by weight of carbon dioxide (see
specification, pages 4-5; first reply brief, page 2), and encompasses the carbon dioxide content of
the HDI in the comparative example. Appellants further submit that the examples reported in the
Pedain declaration are similar to Comparative Example 5 (brief, page 4). We find that the first
three declaration examples use the same benzyl substituted catalyst as in Comparative Example
5, but the ppm by weight of carbon dioxide of the HDI used in the declaration examples is not
reported.
Comparative Examples 8, 9 and 10, the only other comparative examples in the
specification, use the hydroxypropyl substituted ammonium hydroxide catalyst disclosed by Bock
(e.g., col. 4, line 10; see also col. 3, lines 25-62), and HDI which contain 4, 6 and 2 ppm by
weight of carbon dioxide, respectively. In this respect, appellants admit that HDI used in these
comparative examples were known (see brief, page 3; see also prior decision, pages 7-8 (see
above note 4; Paper No. 15)), and Bock teaches that the HDI used with the hydroxyalkyl
substituted catalysts should be “as pure as possible and which is preferably distilled and
colorless” (col. 6, lines 10-12). Thus, we find that these comparative examples reasonably
represent the teachings of Bock to use highly purified HDI with the hydroxyalkyl substituted
catalyst combined with the admitted knowledge that HDI containing such low ppm of carbon
dioxide were known. In comparison with the claimed process encompassed by appealed claim 1,
these comparative examples differ in the hydroxypropyl substituted catalyst which is not a
claimed catalyst.
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