Patent EA-005112-B1 (EA)
Title: Ethylene copolymers and films thereof
Inventor: CHAI CHOON KOOI
IPC: G06F7/72
Filed: 2000-04-26
Abstract: 1. A copolymer of ethylene and an alpha olefin having 3 to 10 carbon atoms, said polymer having (a) a density in the range 0.900 to 0.940 (b) an apparent Mw/Mn of 2-3.4 (c) I21/I2 from 16 to 24 (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 Ea is activation energy of flow, and g' is the ratio of the measured intrinsic viscosity divided by the intrinsic viscosity of a linear polymer having the same molecular weight, HMW is high molecular weight components, LMW is low molecular weight components and I21/I2 is ratio of melt viscosity based on melt flow ratio at (190/21.6) and (190/2.16). 2. A copolymer according to claim 1 having an apparent Mw/Mn in the range 2 to 3 and I21/I2 from 18 to 24. 3. A copolymer according to claim 2 having an apparent Mw/Mn in the range 2.5 to 3, an activation energy of flow from 30 to 35 KJ/mol., and a ratio Ea(HMW)/Ea (LMW) > 1.2. 4. A process for preparing copolymers according to claims 1 to 3 comprising polymerising ethylene and alpha olefins having 3 to 10 carbon atoms 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 nonhydrogen 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 eta<4> bonded diene group having up to 30 non-hydrogen atoms, which forms a pi-complex 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*2SiR*2, CR*2CR*2, CR*=CR*, CR*2SiR*2 or GeR2 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) an activator, and (c) a support. 5. A process according to claim 4 wherein the metallocene complex is a titanium complex. 6. A process according to claim 4 wherein the metallocene complex is (t-butylamido)(tetramethyl-eta<5>-cyclopentadienyl) dimethylsilanetitanium-eta<4>-1,3-pentadiene. 7. A process according to claims 4 or 5 wherein the alpha olefin is 1-hexene. 8. A process according to claims 4 to 7 carried out continuously in the gas phase. 9. A film or other article of manufacture produced from a copolymer according to claims 1 to 3. 10. A film exhibiting a haze determined by ASTM D-1003 ranging from 3 to 20, a dart impact measured by ASTM D-1709 of > 100g, a hexane extractables content of 0.11.5%, said film comprising a copolymer of ethylene and an alpha-olefin having 3-10 carbon atoms and which has (a) a density in the range 0.900 to 0.940 (b) an apparent Mw/Mn of 2-3.4 (c) I21/I2 from 16 to 24 (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. 11. A film according to claim 11 wherein the copolymer has an apparent Mw/Mn in the range 2.5 to 3, an activation energy of flow from 30 to 35 KJ/mol., and a ratio Ea(HMW)/Ea (LMW) > 1.2. 12. A blend of two or more components comprising (a) from about 1 weight percent to about 99 weight percent of a copolymer according to claims 1 to 3, and (b) from about 99 weight percent to about 1 weight percent of one or more resins that are different from component (a).