Appeal No. 1999-1008
Application 08/713,905
specified in Example 1” was phosgenated in liquid phase in monochlorobenzene solvent by a
process that was not attributed to any prior art reference (cf. id., lines 27-29). The “reaction
mixture” was described thusly:
It was not possible to achieve a complete elucidation of the reaction mixture. After
blowing off of the excess phosgene with nitrogen, filtration and working up by
distillation, 19.5 g (19.6% of the theoretical yield) of a slightly colored liquid was
obtained, having a boiling range of 80 to 85°C/).07 mbar and an NCO content in
accordance with DIN 53 185 of 45.2%. [Id., lines 15-21.]
It is further disclosed that modifications in solvent and in starting material did not increase “the
yield of diisocyanate substantially” and that “[t]he residual chlorine content of the product was in
no case below 0.1%” (id., lines 22-26).
In comparison, in specification Example 1, the reaction mixture is subjected to a number
different processes in working up the product mixture to a purity of 99.7% and a content of
hydrolyzable chlorine of 43 ppm (page 7, line 25, to page 8, line 29, particularly page 8, lines 16-
24). We further note that appellants disclose in the specification that “[t]he process of the
present invention may be carried out using known techniques,” including several disclosed in the
patent literature (page 4, lines 23-25), and that recovered ether isocyanate product can “be
isolated in pure form by known processes such as distillation, crystallization, extraction or film
distillation, or recovered as raw product (solution)” (page 5, lines 16-21).
Based on our review, we find that the written description in the specification in its
entirety does not convey with reasonable clarity to one skilled in this art that appellants were in
possession of the claimed ether diisocyanate products “having a hydrolyzable chlorine content of
less than 0.1%” encompassed by appealed claim 3, when the application was filed. Indeed, while
appellants indicate that unspecified “[c]ertain ether isocyanates” produced by an unspecified
prior art base phosgenation process have “residual chlorine contents (0.1%),” that is, 1000 ppm,
which is “very high” and not useful as “raw materials for coating,” they have also described at
least one specific prior art process as producing ether (poly)isocyanates at a hydrolyzable
chlorine content as low as 400 ppm, which content is further described to be “far too high for
many applications, particularly . . . coating compositions.” Not only does the latter disclosure
beg the question of what is an acceptable chlorine content for an ether isocyanate in ppm for
coating compositions to one skilled in this art if 400 ppm is far too high for that purpose, but it
- 10 -
Page: Previous 1 2 3 4 5 6 7 8 9 10 11 12 13 Next
Last modified: November 3, 2007