Patent ID: 6919414

Claim:
A process for preparing copolymers of ethylene and alpha olefins having 3 to 10 carbon atoms having (a) a density in the range 0.900 to 0.940 (b) an apparent Mw/Mn of 2-3.4 (c) I 21 /I 2 from 16 to 21.5 (d) activation energy of flow from 28 to 45 kJ/mol (e) a ratio Ea(HMW)/Ea(LMW) >1.1, and (f) a ratio g′(HMW)/g′(LMW) from 0.85 to 0.95, said process carried out in the presence of a catalyst system comprising (a) a metallocene complex of the general formula wherein: R′ each occurrence is independently selected from hydrogen, hydrocarbyl, silyl, germyl, halo, cyano, and combinations thereof, said R′ having up to 20 non-hydrogen atoms, and optionally, two R′ groups (where R′ is not hydrogen, halo or cyano) together form a divalent derivative thereof connected to adjacent positions of the cyclopentadienyl ring to form a fused ring structure; X is a neutral η 4 bonded diene group having up to 30 non-hydrogen atoms, which forms π a with M; Y is —O—, —S—, —NR*—, —PR* —, M is titanium or zirconium in the +2 formal oxidation state Z* is SiR* 2 , CR* 2 , SiR* 2 SiR* 2 , CR* 2 CR* 2 , CR*═CR*, CR* 2 SiR* 2 , or GeR* 2 , wherein: R* each occurrence is independently hydrogen, or a member selected from hydrocarbyl, silyl, halogenated alkyl, halogenated aryl, and combinations thereof, said R* having up to 10 non-hydrogen atoms, and optionally, two R* groups from Z* (when R* is not hydrogen), or an R* group from Z* and an R* group from Y form a ring system, (b) a borate, and (c) a support.