Windemuth describes a process for preparing allophanate polyisocyanates containing at least
one bound -NCO group. (Windemuth, col. 1, lines 15-19). The allophanate polyisocyanates of
Windemuth are free of secondary products having isocyanurate structures and are useful in the
production of polyurethane plastics. (Windemuth, col. 1, lines 19-23). The products obtained by
Windemuth’s process are said to be suitable for the production of impregnations or coatings on
substrates, protective paints or adhesives. (Windemuth, col. 8, lines 4-7).
The Hicks Reference
Hicks describes coating compositions that are said to have a long pot life and contain a
polyisocyanate component and an aldimine component. (Hicks, col. 2, lines 13-33). The
polyisocyanate component contains from 5 to 100% by weight of a monoallophanate. (Hicks, col. 2,
lines 17-20).
II. Opinion
The examiner has rejected claims 10-20 under 35 U.S.C. § 103 over Windemuth in view of
Hicks. Appellants’ dispute this rejection.
According to the examiner, Windemuth discloses the production of allophanate containing
polyisocyanates having aromatically bound isocyanate groups. The examiner notes that Windemuth
teaches the production of allophanate containing polyisocyanates having aromatically bound isocyanate
groups wherein a polyisocyanate, such as an aliphatic isocyanate, is reacted with a hydroxyl function
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Last modified: November 3, 2007