Appeal No. 95-2233
Application 07/978,014
in view of its February 28, 1992, filing date. Narayanan
discloses a copolymer of vinylpyrrolidone and vinyl acetate and a
polyvinylpyrrolidone grafted with butene for use in agricultural
formulations. See column 6, lines 10 through 22. Narayanan
further discloses that the polymers of his invention, including
the polymers described in column 6, are useful for controlling
agrichemical leaching. According to Narayanan,
The inhibiting effect of the present
polymers is achieved by their complexing,
encapsulation, or blending with the
agrichemical and applying to a plant site. In
the leach inhibiting copolymers of the
present invention, the lactam ring provides
the hydrophilic moiety and the alkyl chain of
the copolymer provides the hydrophobic
portion. Correct balance between the
hydrophilic and hydrophobic portions enable
bonding of the agrichemical to the polymer
and also cause a portion of the polymer to
bind to the soil surface by either
hydrophobic or hydrophilic interaction with
organic matter in the soil. Thus, the
polymer, together with the agrichemical, is
more securely bound to the soil site where it
is applied and leaching by rain water or
irrigation is significantly reduced. In all
instances, using the above active chemicals,
a marked reduction, and in some cases, almost
complete elimination of downward trans-
migration of the agrichemical from the
immediate application area through the soil
stratum is achieved. [emphasis added]
See Narayanan, column 4, line 59 through column 5, line 9. The
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