Appeal No 2007-0310
Application No 10/260,498
BACKGROUND
The specification states that ethylene oxide-capped polyols are
typically produced by polymerizing propylene oxide “in the presence of a
basic catalyst (usually potassium hydroxide (‘KOH’)) to produce a polyol
containing mostly secondary hydroxyl groups,” followed by ethoxylation,
that is, adding ethylene oxide (“EO”) “to the catalyst containing mixture to
convert some or most of the secondary hydroxyl groups to primary hydroxyl
groups.” (Specification 1.) The specification states that, after ethoxylation,
the basic catalyst is “neutralized with an acid and the precipitated salt is
separated from the polyol by filtration or centrifugation, or the basic catalyst
is removed” by another technique. (Id.)
The specification also states that double-metal cyanide (“DMC”)
catalysts “can be used to produce polyether, polyester and polyetherester
polyols,” but that “DMC catalysts cannot be used to directly produce
EO-capped polyols” because “[w]hen EO is added to a polyoxypropylene
polyol produced by DMC catalysis, the resulting product is a heterogeneous
mixture of: (1) un-reacted polyoxypropylene polyol; and (2) highly
ethoxylated polyoxypropylene polyol and/or polyethylene oxide.” (Id. at 2.)
The specification describes two processes for preparing EO-capped
polyols. The first process involves combining a polyol produced in the
presence of a DMC catalyst is combined with a basic catalyst, then
ethoxylating the mixture to produce an EO-capped polyol, and adding acid
to the EO-capped polyol, “with the proviso that no precipitate is formed by
the reaction of the acid with the basic catalyst.” (Id. at 5.) The second
process is similar, but the polyol produced in the presence of a DMC catalyst
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Last modified: September 9, 2013