Appeal No. 95-3827
Application No. 08/031,793
isocyanates. Claim 1 is illustrative of the subject matter on
appeal and reads as follows:
1. A process for the production of an isocyanate or a
mixture of isocyanates which is substantially free of color
imparting material comprising treating a phosgenation product
of an amine with hydrogen at a pressure of from about 3 to
about 150 bar at a temperature of from about 100 to about
180°C for from about 15 minutes to about 4 hours in the
presence of a catalyst.
The sole reference relied upon by the examiner is:
Bruchmann 2,038,126 Sep. 15, 1991
(Canada)
The sole issue in this appeal is whether claims 1-16 were
properly rejected under 35 U.S.C. § 103 as unpatentable over
Bruchmann.
Discussion
The claimed invention is directed to a process for the
production of an isocyanate or a mixture of isocyanates which
is substantially free of color imparting material comprising
treating a phosgenation product of an amine with hydrogen at a
specific temperature and pressure for a period of time in the
presence of a catalyst.
Bruchmann discloses a method of improving the quality of
crude diaminodiphenylmethanes comprising the treatment thereof
2
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