Patent ID: 6166152
Filing Date: 2000-12-26
Classification: C08F,Y10S

Abstract:
A method comprising polymerizing monomers to produce a linear, low density polymer of ethylene and 1-hexene having a density in the range of about 0.915 to about 0.930 grams/cc in a continuous loop reactor under slurry phase reactor conditions in the presence of a liquid diluent comprising (a) using a prepolymerized solid particulate metallocene catalyst system, (b) combining the catalyst system with a liquid diluent, and (c) agitating the mixture of (b) to form a liquid mixture containing catalyst system particles that are substantially uniform in size, (d) passing this liquid mixture into the loop reactor, (e) not adding any hydrogen, (f) employing the temperature in the range of about 170.degree. F. to about 180.degree. F., (g) employing ethylene in an amount equal to about 5 to about 6 weight % of the liquid diluent and the loop reactor, and (h) employing 1-hexene in an amount equal to about 1.5 to about 2.5 weight % of the liquid diluent in the loop reactor, further characterized by the fact that the prepolymerized solid particulate metallocene catalyst system is prepared by the process comprising (a) combining in a liquid an organoaluminoxane and at least one metallocene having at least one cyclopentadienyl, indenyl, tetrahydroindenyl, octahydroindenyl, or fluorenyl ligand having at least one olefinically unsaturated substitutent to form a liquid catalyst system, (b) conducting prepolymerization of at least one olefin in the presence of said catalyst system to produce a prepolymerized solid catalyst containing no more than about 95 weight percent prepolymer, and (c) separating the resulting solid from the liquid and components dissolved in said liquid.