Appeal No. 2004-2208
Application No. 10/158,988
component composed essentially of diols is reacted with an
excess of diisocyanate to yield an isocyanate-terminated
prepolymer containing a relatively low isocyanate content
(preferably 2-4%) and then chain extended with a diamine.
(Column 6, lines 17-30.) According to Seneker, the polyol
component must comprise one or more high molecular weight,
ultra-low unsaturation polyoxypropylene polyols in admixture
with one or more polytetramethylene ether glycols (PTMEG).
(Column 7, lines 31-36.)
Seneker’s working examples describe the use of diols having
the here recited characteristics to form isocyanate prepolymers
having the here recited NCO contents. (Examples 1-4, Tables 1-
4.) No mention is made in Seneker’s examples regarding the use
of any catalysts to form the isocyanate prepolymer.3 (Column 11,
lines 24-58.) As pointed out by the examiner, Comparative
Example 5 of the present specification shows that a
polyurethane/urea made from an isocyanate prepolymer prepared
without any catalyst and a polyurethane urea made from an
3 In this regard, Seneker teaches: “The reaction of the
isocyanate with the polyol may be catalyzed with standard
catalysts such as dibutyltin dilaurate, but may take place
without catalysis.” (Emphasis added; col. 9, ll. 56-59.)
7
Page: Previous 1 2 3 4 5 6 7 8 9 10 11 12 Next
Last modified: November 3, 2007