Appeal No. 2006-2247
Reexamination Nos. 90/006,554 and 90/006,894
1 46. From 1987 to the present, Dr. Boeckh has been an employee of the
2 appellant patent owner (BASF). (Boeckh Declaration, ¶1.)
3 47. Dr. Boeckh acknowledges that “it was known in the chemical field to
4 oxidize PVP using glacial acetic acid as a solvent and an aqueous
5 solution of hydrogen peroxide as the oxidizing agent.” (Boeckh
6 Declaration, ¶5.)
7 48. Dr. Boeckh asserts:
8 The problem we faced and solved with our invention in
9 the ‘684 patent, therefore, was not increasing the degrees of
10 oxidation achievable for known processes for N-oxidizing PVP,
11 since such known processes already had achieved high degrees
12 of oxidation in excess of 90%. Rather, we recognized that it
13 was highly desirable to reduce the amount of acid in the
14 reaction vessel during PVP N-oxidation, by replacing acid with
15 water, to avoid the prior art problem of having large amounts of
16 acid left in both the reaction vessel (at the end of the reaction)
17 and in the final PVNO product, respectively. For safety
18 purposes in carrying out the reaction during the oxidation
19 reaction, we also recognized that it is highly desirable to
20 operate in a diluted state (by adding water) to reduce any
21 processing problems and hazardous conditions that might occur
22 if the reaction mixture is too viscous due to a high polymer
23 concentration. We further recognized that, even after dilution
24 with water in place of acid, the oxidation reaction needed to
25 proceed at desirable rates to be of any practical use, which is
26 why we chose the specific catalysts in our invention.
27 Therefore, our goal and the overall problem we solved with our
28 invention, was to address each of the foregoing individual
29 issues (reducing acid in the process by increasing water content
30 and adding a catalyst to achieve a desirable reaction rate), while
31 at the same time creating a process that was capable of
32 achieving high degrees of oxidation for the PVNO product.
14
Page: Previous 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 Next
Last modified: November 3, 2007