Appeal No. 1997-2437
Application No. 08/230,378
1. A dispersant comprising a polystyrenesulfonic acid having
a weight-average molecular weight in the range of 2,000 to
100,000 or a salt thereof, wherein at least 70 % of the
terminals of the polymer chains have an indane ring of the
formula (I):
wherein X represents a cation selected from the group
consisting of a hydrogen, alkali metals, alkaline earth
metals, ammonium and organic amines, and n and m each
represent 0 or an integer of at least 1.
In addition to the admitted prior art found in
appellants' specification, the examiner relies upon the
following references as evidence of obviousness:
Young et al. (Young) 2,446,897 Aug. 10, 1948
Yax et al. (Yax) 4,100,336 Jul. 11, 1978
Appellants' claimed invention is directed to a dispersant
comprising a polystyrenesulfonic acid having at least 70% of
the terminals of the polymer chains having an indane ring of
the recited formula. According to appellants, since
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