Appeal No. 95-0192
Application No. 07/914,228
The addition of the fire retardant to
the polyol or the isocyanate prior to the
preparation of the polyurethane is most
convenient and assures essentially uniform
distribution of the fire retardant
throughout the polyurethane. In the
preparation of the polyurethane, the fire
retardants do not interfere with the
reaction and are ordinarily incorporated
physically rather than chemically into the
urethane because most of the additives have
no functionally reactive sites . . .
. . .
Although the compounds of the
invention are effective fire retardants in
polyurethanes when used alone, other known
additives may be incorporated into the
polyurethane in addition to or partial
substitution for these fire retardants.
Representative examples of other compatible
additives include metal ammonium
phosphates,
antimony oxide, a peroxide or another
brominated substrate.
Given these teachings, we agree with the examiner that it
would have been prima facie obvious to disperse either a solid
butene-based flame retardant or other useful conventional
solid flame retardants in the isocyanate solution containing
polyurea particles described by Hughes with a reasonable
expectation of successfully imparting improved physical
characteristics and flame retardant property to the resulting
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