Polymerisation process
A process for the copolymerisation of ethylene and an α-olefin having 7 to 10 carbon atoms in a fluidised bed gas phase reactor in the presence of a single site polymerisation catalyst comprises operating the process in condensed mode and wherein the amount of said α-olefin is maintained below that at which substantial condensation in the reactor occurs. The preferred α-olefin is 1-octene and the preferred single site polymerisation catalyst is a metallocene complex. By use of the process conditions of the present invention, higher α-olefins may be successfully employed in a gas phase process provided the amount of higher α-olefin comonomer is maintained below that at which substantial condensation occurs: Such operation is also dependent upon the operation temperature and the boiling point of the higher α-olefin and the process is particularly advantageous when performed in the presence of catalysts able to incorporate high levels of comonomers at low comonomer inventories.
1 - 11 . (canceled)
12 . A process for the copolymerisation of ethylene and an α-olefin having 7 to 10 carbon atoms in a fluidised bed gas phase reactor in the presence of a single site polymerisation catalyst characterised in that said process is operating in condensed mode and wherein the amount of said α-olefin is maintained below that at which substantial condensation in the reactor occurs.
13 . A process according to claim 12 wherein the partial pressure of ethylene in the reactor is in the range 0.5 to 2 Mpa.
14 . A process according to claim 12 wherein the α-olefin is 1-octene.
15 . A process according to claim 14 wherein the ratio of 1-octene/ethylene partial pressure is in the range 0.0001 to 0.02.
16 . A process according to claim 12 wherein the α-olefin is 1-decene.
17 . A process according to claim 16 wherein the ratio of 1-decene/ethylene partial pressure is in the range 0.00005 to 0.005.
18 . A process according to claim 12 wherein the process is continuous.
19 . A process according to claim 12 wherein the single site polymerisation catalyst is a metallocene complex.
20 . A process according to claim 19 wherein the metallocene complex has 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 hydride or a moiety selected from the group consisting of halo, alkyl, aryl, aryloxy, alkoxy, alkoxyalkyl, amidoalkyl, siloxyalkyl etc. having up to 20 non-hydrogen atoms and neutral Lewis base ligands having up to 20 non-hydrogen atoms,
Y is —O—, —S—, —NR*—, —PR*—,
M is hafnium, titanium or zirconium,
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,
and n is 1 or 2 depending on the valence of M.
21 . A process according to claim 19 wherein the metallocene complex has the general formula
wherein:
R′ each occurrence is independently selected from hydrogen, hydrocarbyl, silyl, germyl, halo, canyo, 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 a π-complex with M;
Y is —O—, —S—, —NR*—, —PR* 13 ,
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.
22 . A process according to claim 20 wherein the metal M is titanium.