Appeal No. 2006-2694
Application No. 09/910,968
nitroxyl-containing inhibitor in the prior art process to be recycled into the
distillation means, and also requires the temperature of the distillation means
to be no higher than 110°C, and the pressure to be less than 760 mm Hg.
Claim 2 requires the nitroxyl inhibitor of claim 1 to have a specific
structural formula.
Claim 9 requires the distillation of claim 1 to be a continuous
operation.
Claim 18 recites the process of claim 2, with the additional
requirement that the inhibitor must be a blend of two nitroxyls.
2. OBVIOUSNESS
Claims 1, 2, 9, and 17-26 stand rejected under 35 U.S.C. § 103 as
obvious in view of Arhancet1 and Higgins.2
The Examiner cites Arhancet as describing “a method for inhibiting
premature polymerization of vinyl aromatic monomers,” using nitroxyl
inhibitors having the claimed formula, “at a temperature of 110°C and under
reduced vacuum.” (Answer 3 (citing Arhancet at col. 1, ll. 16-17; col. 2,
line 10, through col. 3, line 7; claims 6 and 8).) The Examiner
acknowledges that Arhancet differs from claim 1 in that “Arhancet does not
disclose a step of recycling the inhibitor to the distillation column.”
(Answer 3.)
To meet this limitation, the Examiner cites Higgins as “disclos[ing] a
process for production/purification of an unsaturated monomer wherein the
inhibitor is recycled back to the distillation column (see the Figure).”
1 Arhancet, U.S. Patent 5,907,071, issued May 25, 1999.
2 Higgins, Jr. et al., U.S. Patent 4,033,829, issued July 5, 1977.
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