Method for preparing a supported metallocene-alumoxane catalyst for gas phase polymerization

Claim 2

A process for preparing a supported metallocene alumoxane catalyst for gas phase polymerization of olefins, comprising the steps of: (a) adding undehydrated silica gel to a stirred solution of an aluminum trialkyl in an amount sufficient to provide a mole ratio of aluminum trialkyl to water of from 3:1 to 1:2 and allowing the mixture to react: (b) adding a metallocene to the reacted mixture; (c) removing the solvent; (d) drying the solids to a free flowing powder.

Claim 3

Process according to claim 1, wherein said undehydrated silica gel has a water content of from 6 to 10 weight percent.

Claim 4

Process according to claim 1 or claim 2, wherein the mole ratio of aluminum to transition metal in said metallocene is from 1000:1 to 1:1, preferably from 300:1 to 10:1.

Claim 5

Process according to any of the preceding claims, wherein said undehydrated silica gel has a water content of from 7 to 9 weight percent preferably from 7.5 to 8.5 weight percent and the mole ratio of aluminum trialkyl of water is from about 1.2:1 to about 0.9:1, the aluminum trialkyl being preferably trimethyl aluminum or triethyl aluminum.

Claim 6

Process according to any of the preceding claims, wherein said undehydrated silica gel has a surface area of from 200 to 400 m²/g, a pore volume of from 1 to 2 cc/g and a particle size of from 30µ to 60µ, and/or the mole ratio of aluminum to transition metal in said metallocene being preferably from 150:1 to 30:1 and/or said solids being dried preferably at a temperature of from 75°C to 85°C.

Claim 7

Process according to any of the preceding claims wherein the metallocene is of the formula: (Cp) m MR n X q wherein Cp is a cyclopentadienyl ring, M is a Group 4b or 5b transition metal, R is a hydrocarbyl group or hydrocarboxy group having from 1 to 20 carbon atoms, X is a halogen, and m is a whole number from 1 to 3, n is a whole number from 0 to 3, and q is a whole number from 0 to 3; (C₅R′ k ) g R˝ s (C₅R′ k )MQ 3-g ′ or R˝ s (C₅R′ k )₂MQ′ wherein (C₅R′ k ) is a cyclopentadienyl or substituted cyclopentadienyl, each R′ is the same or different and is hydrogen or a hydrocarbyl radical containing from 1 to 20 carbon atoms, a silicon-containing hydrocarbyl radical, or a hydrocarbyl radical wherein two carbon atoms are joined together to form a C₄-C₆ rings, R˝ is C₁-C₄ alkyene radical, a dialkyl germanium or silicone, or an alkyl phosphine or amine radical bridging two (C₅R′ k ) rings, Q is a hydrocarbyl radical having 1-20 carbon atoms, hydrocarboxy radical having 1-20 carbon atoms or halogen and can be the same or different, Q′ is an alkylidene radical having from 1 to about 20 carbon atoms, s is 0 to 1, g is 0, 1 or 2; when g is 0, s is 0; k is 4 when s is 1 and k is 5 when s is 0 and M is as defined above.

Claim 8

Process according to any of the preceding claims wherein said metallocene is zirconocene or titanocene.

Claim 9

Process according to claim 7, wherein said zirconocene is selected from the group consisting of cyclopentadienyl zirconium trichloride; pentamethylcyclopentadienyl zirconium trichloride; bis(cyclopentadienyl)zirconium diphenyl; bis(cyclopentadienyl)zirconium dichloride; alkyl substituted cyclopentadienes, and their dihalide complexes; dialkyl, trialkyl tetra-alkyl, and penta-alkyl cyclopentadienes, and their dihalide complexes; and silicone, phosphorus, and carbon bridged cyclopentadiene complexes.

Claim 10

Process according to claim 7, wherein said titanocene is selected from the group consisting of monocyclopentadienyl titanocenes; bis(cyclopentadienyl) titanium diphenyl; carbenes represented by the formula Cp₂Ti=CH₂ · Al(CH₃)₂Cl and their derivatives, wherein Cp is a cyclopentadienyl or substituted cyclopentadienyl radical; substituted bis(Cp)Ti(IV) compounds and their dihalide complexes; dialkyl, trialkyl, tetra-alkyl and penta-alkyl cyclopentadienyl titanium compounds and their dihalide complexes; and silicone, phosphine, amine or carbon bridged cyclopentadiene complexes, and their dihalide complexes.

Claim 11

Process for polymerizing olefins e.g., ethylene and other α-olefins using a supported metallocene alumoxane catalyst according to any of the preceding claims.

Claim 12

Process for preparing a supported metallocene alumoxane catalyst by combining aluminum trialkyl and an inorganic filler material containing water and then adding a metallocene characterized in that the filler material in the form of silica gel containing absorbed or adsorbed water is added to a stirred solution of the aluminum trialkyl.

Claim 13

Process for preparing a supported metallocene alumoxane catalyst by combining aluminum trialkyl and an inorganic filler material containing water and then adding a metallocene characterized in that the filler material in the form of silica gel containing absorbed or adsorbed water is added to a stirred solution of the aluminum trialkyl.