PROCESS FOR THE POLYMERIZATION OF ALPHA OLEFINS AND NON-CONJUGATED DIENES USING A TOLUENE FREE HOMOGENOUS CO-CATALYST SYSTEM WITH METALLOCENE PRO-CATALYSTS
A homogenous toluene free catalyst system for producing a polyolefin elastomer possessing a unique combination of properties employing a particular type of a metallocene catalyst. Also disclosed is a co-catalyst for activating the metallocene pro-catalyst employing a specific molar ratio of the components of the co-catalyst to the metal of the pro-catalyst.
1 . A process for the polymerization or copolymerization of at least one alpha olefin, and optionally at least one diene monomer, to obtain an elastomer, the process comprising:
a. forming a catalytically effective homogenous solution of toluene free aliphatic hydrocarbon catalyst mixture by blending together:
(i) a co-catalyst blend;
(a) a first component consisting of a modified methylaluminoxane (MMAO) in an aliphatic hydrocarbon; and
(b) a second component having the formula M-R 3 , wherein the M is a metal or metalloid, and R is any alkyl group, aryl group or combinations thereof, with each alkyl or aryl group possessing at least one electron-withdrawing substituent;
(ii) a metallocene pro-catalyst comprising a transition metal; and
b. polymerizing an alpha olefin in the presence of the catalytically effective homogenous solution of toluene free aliphatic hydrocarbon catalyst to form a polyolefin elastomer.
2 . The process of claim 1 , wherein the co-catalyst is selected from the group consisting of: alkylaluminum alkoxide, siloxalane, dimeric aluminoxane and oligomeric aluminoxane.
3 . The process of claim 2 , wherein the co-catalyst is a perfluoroarylborane.
4 . The process of claim 3 , wherein the perfluoroarylborane is tris(pentafluorophenyl) borane.
5 . The process of claim 1 , wherein the metalloid is a boron compound other than a boron salt.
6 . The process of claim 1 , wherein the metallocene pro-catalyst is selected from the group consisting of: zirconocene dichloride, dimethylbis(indenyl) zirconium, racemic-ethylenebis(indenyl) zirconium dichloride, dimethylsilyl bis(cyclopentadienyl) zirconium dichloride, dimethylsilyl(tetramethylcyclopentadienyl)(tert-butylamido) titanium dichloride, diphenylmethylene (cyclopentadienyl-9-fluorenyl)zirconium dichloride and diphenylsilyl(cyclopentadienyl-9-fluorenyl)zirconium dichloride.
7 . The process of claim 2 , wherein the alkylaluminum alkoxide is diisobutylaluminum-tert-butoxide.
8 . The process of claim 2 , wherein the siloxalane is diethylaluminum trimethylsiloxane.
9 . The process of claim 2 , wherein the dimeric aluminoxane is tetraisobutylaluminoxane.
10 . The process of claim 2 , wherein the oligomeric aluminoxane is methylaluminoxane or modified methylaluminoxane.
11 . The process of claim 1 , wherein the molar ratio of the first component of the co-catalyst to the transition metal is from 10 to 1,000.
12 . The process of claim 1 , wherein the molar ratio of the second component of the co-catalyst to the transition metal is from 0.2 to 10.
13 . The process of claim 1 , wherein the first component of the co-catalyst is combined with the second component of the co-catalyst.
14 . The process of claim 13 , wherein the metallocene pro-catalyst is combined with a reaction product of the combination of the first component of the co-catalyst and the second component of the co-catalyst.
15 . The process of claim 1 , wherein the co-catalyst further comprises a third component.
16 . The process of claim 15 , wherein the third component is a trialkylaluminum.
17 . The process of claim 16 , wherein the trialkylaluminum is selected from the group consisting of: trimethylaluminum, triethylaluminum, tri(n-propyl)aluminum, triisopropylaluminum, tri(n-butyl)aluminum, triisobutylaluminum tri(n-hexyl)aluminum and tri(n-octyl)aluminum.
18 . The process of claim 15 , wherein the molar ratio of the third component to the transition metal is from 0.1 to 1,000.
19 . The process of claim 1 , wherein the .alpha.-olefin contains from 2 to 20 carbon atoms and the diene, where present, is a conjugated or nonconjugated, acyclic or cyclic, diene.
20 . The process of claim 1 , wherein the alpha-olefin is selected from the group consisting of: ethylene and propylene.
21 . The process of claim 1 , wherein the elastomer possesses an M w of from 70,000 to 2,000,000, an ML 1+4 at 125 degrees Celsius of from 10 to 200, an M w /M n of from 1.5 to 10, and a T g of below a −40 degrees Celsius.
22 . The process of claim 1 , wherein the elastomer possesses an M, of from 250,000 to 1,750,000, an ML 1+4 at 125 degrees Celsius of from 15 to 150, an M w /M n of from 2 to 7.5, and a T g of below −40 degrees Celsius.