Appeal No. 96-2335
Application 08/213,375
The examiner alleges that Baron teaches a method of purification of N-
acetyl-p-aminophenol “whereby they use salts of oxygen acids of sulfur to prewash the
adsorbent carbon, similar to those described in the recited claims” (citing Baron, column 2,
lines 15-25, column 3, lines 50-65 and column 4, lines 60-70). The examiner also alleges
that the only difference between the Baron process and the claimed process is that
Baron’s process “does not mention the contact time between charcoal and the sulfite as
against prewash of carbon with sulfite for ½ hour to 1 hour in the claimed process” (pages
2 and 3 of the Answer). To overcome this alleged deficiency the examiner relies upon
Kosak stating that the time of contact between the hot phenol and ferric chloride and
activated carbon in Kosak is between 15 minutes to 2 hours. The examiner concludes that
one of ordinary skill in this art would have modified Baron to have a contact time between
phenol and pretreated activated charcoal because Kosak suggests a similar contact time.
We disagree with the examiner’s position. The Patent and Trademark
Office (PTO ) has the burden under 35 U.S.C. § 103 to establish a prima facie case of
obviousness. In re Piasecki, 745 F.2d 1468, 1471-1472, 223 USPQ 785, 787-788 (Fed.
Cir. 1984). This burden can be satisfied when the PTO presents evidence, by means of
some teaching, suggestion, or inference either in the applied prior art or our generally
available knowledge, that would appear to have suggested the claimed subject matter to a
3
Page: Previous 1 2 3 4 5 6 7 Next
Last modified: November 3, 2007