Appeal No. 95-3233
Application No. 08/094,477
10. A process for the production of polypropylene
comprising continuously contacting liquid propylene or a
mixture comprising liquid propylene and one or more other
alpha-olefins in one or more reaction zones, under gas phase
polymerization conditions, with a catalyst system comprising
(i) a solid particulate catalyst precursor, which includes
magnesium; titanium; a halogen which is chlorine, bromine, or
iodine, or mixtures thereof; and, as an inside electron donor,
a carboxylic acid ester; (ii) a hydrocarbylaluminum
cocatalyst; and (iii) as an outside electron donor a silicon
compound containing at least one silicon-oxygen-carbon
linkage,
with the proviso that the precursor alone is carried into
the reaction zone(s) via a portion of the liquid propylene,
the amount of said portion being about 0.1 to about 11 percent
by weight based on the weight of the total liquid propylene
and the flow rate of said portion being at least 110 pounds
per hour and having a Reynolds number greater than about
20,000.
The examiner relies upon the following references as
evidence of obviousness:
Brady, III et al. (Brady) 5,093,415 Mar. 3, 1992
(filed May 19, 1987)
Kondo et al. (Kondo) 3-73,564 Nov. 22, 1991
(Japanese patent application)
Appellants' claimed invention is directed to a process
for producing polypropylene that is characterized by
appellants as an improvement over the process described in
Brady, U.S. Patent No. 5,093,415. The purported improvement
over Brady entails feeding the catalyst precursor, alone, into
the reaction zone along with a portion of the liquid propylene
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