Appeal No. 1997-2330 Page 8
Application No. 08/398,315
The formation of the Example 5 emulsion begins with the production of a intermediate
polyurethane resin dissolved in a hydrocarbon solvent. Example 1 discloses xylol as an ingredient.
Claims 9 and 10 of Eckhoff indicate that the polyurethane is dissolved in a hydrocarbon solvent
consisting of xylene and mineral spirits. Xylol is a mixture of xylenes. Eckhoff discloses using xylol in
Example 1 to “reduce the non-volatile content [of the polyurethane intermediate] to 84%.” It is being
used as a solvent. The polyurethane intermediate dissolved in solvent made by the process of Example
1 is converted into an alkyd-modified polyurethane as illustrated in Example 3. Further xylol solvent is
added according to the Example 3. As the xylol is being used as a solvent and not as a reactant, we
cannot conclude that it is converted during processing. The formulation of Example 5 contains xylol
and Appellants indicate that xylol is an excluded water-insoluble coalescent.
Example 7 is the only other example directed to a composition containing polyurethane
dispersion and latex. As pointed out by Appellants at page 17 of the Brief, Eckhoff’s Example 7
composition contains 2,2,4-trimethylpentane-1,3-diol monoisobutyrate, a water-insoluble coalescent . 2
There is no suggestion in either Eckhoff or Adamson for excluding the water-insoluble coalescent.
Therefore, we cannot conclude that the exclusion of water-insoluble coalescent would have been
obvious to one of ordinary skill in the art at the time of invention.
2Note that Appellants specifically state in the Specification at page 6 that water-insoluble
coalescents include, for example, 2,2,4-trimethylpentane-1,3-diol monoisobutyrate.
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