Appeal No. 1998-3209
Application 08/338,284
reference provides that the polymerization is conducted in the presence of a highly active catalyst
system and a silane compound, wherein the catalyst system can be, inter alia, a titanium
containing component on a magnesium halide support, a co-catalyst that can be an aluminum-
alkyl compound, and can contain other ingredients and components; wherein the silane
compound can be an organo silane having, inter alia, a cycloalkyl substituent that is
“cyclopentyl” (e.g., col. 5, line 55, to col. 2, line 10, and col. 11, line 4, to col. 15, line 22).
Based on this evidence in Cohen, we agree with the examiner that, prima facie, one of
ordinary skill in this art routinely following the teachings of the reference with respect to the
preparation of crystalline homo- and copolymers of propylene by sequential polymerization in at
least two stages, would have routinely used a catalyst comprising a magnesium halide supported
solid catalyst, an aluminum-alkyl cocatalyst and a silane compound that is substituted with a
cyclopentyl group, in the reasonable expectation of successfully obtaining a homo- and
copolymer having a molecular weight distribution of between 6 and 50 and “a useful melt flow
rate” of between 0.1 and 200 grams per 10 minute as taught by the reference, and thus would
have reasonably arrived at homo- and copolymers of propylene falling within appealed claim 1.
See Merck & Co., Inc. v. Biocraft Labs., Inc., 874 F.2d 804, 807, 10 USPQ2d 1843, 1845-46
(Fed. Cir. 1989); In re Lemin, 332 F.2d 839, 841, 141 USPQ 814, 815-16 (CCPA 1964). Indeed,
the claimed molecular weight distribution of greater than 20 and the claimed melt index value of
greater than 2g/10 minutes for the claimed crystalline homo- and copolymers of propylene clearly
overlap with the ranges for these values taught by Cohen, thus shifting the burden to appellants to
establish the criticality of the claimed ranges. See generally, In re Geisler, 116 F.3d 1465, 1470,
43 USPQ2d 1362, 1365 (Fed. Cir. 1997); In re Boesch, 617 F.2d 272, 276, 205 USPQ 215, 219
(CCPA 1980); Lemin, supra.
Furthermore, as pointed out by the examiner, while the crystalline propylene
homopolymer of Cohen Example 14 differs from the claimed crystalline propylene homopolymer
in the melt index value, one of ordinary skill in the art routinely following the teachings of Cohen
would have adjusted the molecular weight distribution by using hydrogen in the reasonable
expectation of obtaining any desired melt index (answer, pages 5-6). Thus, prima facie, one of
ordinary skill in this art routinely following the teachings of Cohen would have arrived at a
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