Appeal No. 2006-1273
Application No. 10/420,400
that the catalyst can be added as a liquid. See König et al.’s “Application examples” in
which a 3% solution of tetraphosphonium phenolate is used to make polycarbonates (col.
5, lines 32-34). See also König et al.’s Example 2 wherein a liquid product is obtained
by using a 10:1 molar ratio and a 100% yield is obtained. (Col. 5, lines 5-22.) Clearly, in
order to avoid the additional steps of crystallizing the product and then resolubilizing it in
phenol, with a possible loss in yield, it would have been desirable to make the product in
the liquid form—a form already expressly taught and used by the prior art.
Turning to the addition of the slightly soluble alcohol and considering the claimed
invention as a whole, we first note that the slightly soluble alcohols used by Appellants
and disclosed in König et al. are substantially the same (compare König et al., col. 1,
lines 53-64, with the ‘400 Application, page 7, line 22- page 8, line 5). Likewise, the
range ratios of alcohol to aqueous reaction mixture are substantially the same (compare
claim 2 of König et al. with claim 1 of the ‘400 Application). (See also the Examiner’s
Answer, pages 4-5.) Further, one of ordinary skill in this art would have recognized the
alcohol addition could be made at any time prior to working up the reaction mixture.
(See id.) Such a modification to the process expressly taught by König et al. would have
been expected to yield at least a comparable product.
First, König et al. explain that the function of the alcohol is to facilitate working
up the reaction mixture and therefore not to participate in the reaction (see col. 1, lines
65-66; see also Examiner’s Ans., page 6). Second, it is clear the alcohol is not necessary
for the synthesis, in that the synthesis is also conducted by König et al. without the
alcohol present (see, e.g., Example 2, col. 5, lines 5-22; see also Examiner’s Answer,
page 4). Finally, König et al. teach that adding the alcohol is preferred (col 2. lines 7-13).
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