Appeal No. 94-3973
Application 08/029,754
the resulting solution of sulfonated or neutralized sulfonated polymer in a volatile hydrocarbon liquid is
the same as or similar to the solution of sulfonated polymer or neutralized sulfonated polymer in
hydrocarbon oil obtained by the process in appealed claim 8. Uniroyal, Inc. v. Rudkin-Wiley Corp.,
837 F.2d 1044, 1050-54, 5 USPQ2d 1434, 1438-41 (Fed. Cir.), cert. denied, 488 U.S. 825 (1988);
In re Dow Chemical Co., 837 F.2d 469, 473, 5 USPQ2d 1529, 1531-32 (Fed. Cir. 1988);
compare In re Spada, 911 F.2d 705, 708-09, 15 USPQ2d 1655, 1657-58 (Fed. Cir. 1990); In re
Best, 562 F.2d 1252, 1255-56, 195 USPQ 430, 433-34 (CCPA 1977).
We do not reach the same conclusion with respect to the drilling mud additive concentrate
compositions of appealed claims 1 through 4. All that claim 1 requires is the combination of a
hydrocarbon oil used in oil-based drilling muds and a sulfonated or neutralized sulfonated polymer as a
viscosification agent. Indeed, we find no limitation in claim 1 which requires that the sulfonated or
neutralized sulfonated polymer must be dissolved in the hydrocarbon oil even to some extent.. We are
of the opinion that such a mixture would have been reasonably suggested to one of ordinary skill in this
art by the teachings of Lundberg and Thaler, which person would have been further motivated to use a
low toxicity hydrocarbon oil in such a composition by Duke and Jachnik. Indeed, Lundberg discloses
that A[i]t has been observed that sulfonated polymers formed by sulfonation often do not readily
dissolve in hydrocarbons such as diesel oil or solvent 100 neutral and similar hydrocarbon solvents@
(col. 6, lines 8-11; emphasis ours). Thus, Lundberg teaches that as little as 1 part by weight of a polar
solvent, which is soluble or miscible with the oil-based drilling fluids, per 100 parts by weight of oil in the
drilling fluid can be used to more rapidly and completely dissolve sulfonated polymers, which are
normally insoluble in the oil, in the oil-based drilling muds (col. 6, lines 16-30 and 38-62). Lundberg
further teaches that the addition of the polar solvent is optional and that Aat lower sulfonate levels, . . .
these polymers can be dissolved in the absence of such cosolvents@ (col. 2, lines 31-37, and col. 6, lines
30-33). Thaler provides similar teachings with respect to other sulfonated and neutralized sulfonated
polymers (col. 2, lines 36-43; and col. 4, line 62, to col. 5, line 43).
We are of the opinion that one of ordinary skill in this art armed with the knowledge in the art
that sulfonated polymers had been observed to dissolve at least to some extent in hydrocarbons per se,
such as diesel fuel, that are used as hydrocarbon oils in oil-based drilling muds, as acknowledged by
Lundberg and Thaler, would have been motivated to combine a lower level sulfonated polymer with
such a hydrocarbon oil without the aid of a polar cosolvent as well as to combine a higher level
sulfonated polymer with such a hydrocarbon oil with the aid of a polar cosolvent in the amount in
- 4 -
Page: Previous 1 2 3 4 5 6 7 Next
Last modified: November 3, 2007