Multistep process for preparing heterophasic propylene copolymers
A multistage process comprising the following steps: a) polymerizing propylene with optionally one or more monomers selected from ethylene and alpha olefins of formula CH 2 ═CHT 1 , wherein T 1 is a C 2 -C 20 alkyl radical in the presence of a catalysts system, supported on an inert carrier comprising: i) a transition metal compound containing a ligand having a cyclopentadienyl skeleton; and ii) an alumoxane or a compound capable of forming an alkyl metallocene cation; b) contacting, under polymerization conditions, in a gas phase, ethylene with one or more alpha olefins of formula CH 2 ═CHT 1 , wherein T 1 is a C 2 -C 20 alkyl radical, and optionally a non-conjugated diene, in the presence of the polymer obtained in step a), in the presence of a weigh ratio hydrogen/hethylene higher than 1 ppm and optionally in the presence of an additional organo aluminum compound; wherein the amount of the polymer obtained in step a) ranges from 5% by weight and 90% by weight of the polymer obtained in the whole process and the amount of polymer obtained in step b) ranges from 10% by weight and 95% by weight of the polymer obtained in the whole process.
1 - 19 . (canceled)
20 . A multistage process comprising the following steps:
a) polymerizing a propylene resin optionally comprising one or more monomers selected from ethylene and alpha olefins of formula CH 2 ═CHT 1 , wherein T 1 is a C 2 -C 20 alkyl radical, in presence of a catalyst system, the catalyst system supported on an inert carrier comprising:
(i) a transition metal compound containing a ligand having a cyclopentadienyl skeleton; and
(ii) an alumoxane or a compound capable of forming an alkyl metallocene cation;
b) contacting under polymerization conditions in a gas phase, ethylene with one or more alpha olefins of formula CH 2 ═CHT 1 , wherein T 1 is a C 2 -C 20 alkyl radical, and optionally a non-conjugated diene, to produce an ethylene resin in presence of the propylene resin and hydrogen,
wherein the weight ratio of hydrogen/ethylene being higher than 1 ppm, and the amount of the propylene resin ranges from 5% by weight to 90% by weight, and the amount of the ethylene resin ranges from 10% by weight to 95% by weight.
21 . The process according to claim 20 , wherein the catalyst system further comprises iii) an organo aluminum compound.
22 . The process according to claim 21 , wherein the ethylene resin is produced in presence of an additional organo aluminum compound.
23 . The process according to claim 20 , wherein the weight ratio of hydrogen/ethylene ranges from 5 to 2000 ppm.
24 . The process according to claim 20 , wherein the transition metal compound comprises a ligand having a cyclopentadienyl skeleton of formula (I):
wherein M is a transition metal selected from those belonging to group 3, 4, 5, 6 or to a lanthanide or actinide group in the Periodic Table of the Elements;
p is an integer from 0 to 3, wherein p is equal to a formal oxidation state of M minus 2;
X, equal to or different, is hydrogen, a halogen, or R, OR, OSO 2 CF 3 , OCOR, SR, NR 2 or PR 2 , wherein R is a linear or branched, saturated or unsaturated C 1 -C 20 alkyl, C 3 -C 20 cycloalkyl, C 6 -C 20 aryl, C 7 -C 20 alkylaryl or C 7 -C 20 arylalkyl radical, optionally containing heteroatoms belonging to groups 13-17 of the Periodic Table of the Elements; or two X can optionally form a substituted or unsubstituted butadienyl radical or OR′O, wherein R′ is a divalent radical selected from C 1 -C 20 alkylidene, C 6 -C 40 arylidene, C 7 -C 40 alkylarylidene and C 7 -C 40 arylalkylidene radicals;
L is a divalent bridging group selected from C 1 -C 20 alkylidene, C 3 -C 20 cycloalkylidene, C 6 -C 20 arylidene, C 7 -C 20 alkylarylidene, or C 7 -C 20 arylalkylidene radicals optionally containing heteroatoms belonging to groups 13-17 of the Periodic Table of the Elements, and silylidene radicals containing up to 5 silicon atoms;
R 1 , R 2 , R 3 and R 4 , equal to or different from each other, are hydrogen or linear or branched, saturated or unsaturated C 1 -C 20 -alkyl, C 3 -C 20 -cycloalkyl, C 6 -C 20 -aryl, C 7 -C 40 -alkylaryl, or C 7 -C 40 -arylalkyl radicals, optionally containing one or more heteroatoms belonging to groups 13-17 of the Periodic Table of the Elements;
T, equal to or different from each other, is a moiety of formula (IIa) or (IIb):
wherein the atom marked with symbol * bonds to the atom marked with the same symbol in the transition metal compound of formula (I);
R 5 , R 6 , R 7 , R 8 , R 9 and R 10 , equal to or different from each other, are hydrogen or linear or branched, saturated or unsaturated C 1 -C 40 -alkyl, C 3 -C 40 -cycloalkyl, C 6 -C 40 -aryl, C 7 -C 40 -alkylaryl, or C 7 -C 40 -arylalkyl radicals, optionally containing one or more heteroatoms belonging to groups 13-17 of the Periodic Table of the Elements; or
two or more R 3 , R 4 , R 5 , R 6 and R 7 can join to form a 4-7 membered saturated or unsaturated ring, said ring can bear at least one C 1 -C 20 alkyl substituent.
25 . The process according to claim 24 , wherein M is titanium, zirconium or hafnium; p is 2; X is hydrogen, a halogen, or R, wherein R is defined as in claim 1 ; L is selected from the group consisting of is Si(CH 3 ) 2 , SiPh 2 , SiPhMe, SiMe(SiMe 3 ), CH 2 , (CH 2 ) 2 , (CH 2 ) 3 and C(CH 3 ) 2 ; R 1 and R 2 , equal to or different from each other, are methyl, ethyl or isopropyl radicals; and R 3 and R 4 are hydrogen.
26 . The process according to claim 24 , wherein R 6 and R 8 are hydrogen; R 7 is hydrogen or a C 1 -C 20 -alkyl radical; and R 10 is a linear or branched C 1 -C 20 -alkyl radical.
27 . The process according to claim 24 , wherein R 5 and R 9 are moieties of formula (III):
wherein R 11 , R 12 , R 13 , R 14 and R 15 , equal to or different from each other, are hydrogen or linear or branched, saturated or unsaturated C 1 -C 20 -alkyl, C 3 -C 20 -cycloalkyl, C 6 -C 20 -aryl, C 7 -C 20 -alkylaryl, or C 7 -C 20 -arylalkyl radicals, optionally containing one or more heteroatoms belonging to groups 13-17 of the Periodic Table of the Elements; or two or more R 11 , R 12 , R 13 , R 14 and R 15 can join to form a 4-7 membered saturated or unsaturated membered ring, said ring can bear at least one C 1 -C 10 alkyl substituent;
28 . The process according to claim 27 , wherein at least one substituent selected from the group consisting of R 11 , R 12 , R 13 , R 14 and R 15 is a linear or branched, saturated or unsaturated C 1 -C 20 -alkyl radical.
29 . The process according to claim 24 , wherein T have formula (IIa).
30 . The process according to claim 24 , wherein T have formula (IIb).
31 . The process according to claim 24 , wherein T are different and have formulas (IIb) and (IIa).
32 . The process according to claim 20 , wherein the catalyst system is supported on a porous organic polymer.
33 . The process according to claim 20 , wherein the process of polymerizing a propylene resin further comprises a prepolymerization step.
34 . The process according to claim 20 , wherein the process of polymerizing a propylene resin is carried out in presence of hydrogen.
35 . The process according to claim 20 , wherein the propylene resin comprises from 30% to 70% by weight of a propylene homopolymer or propylene copolymer containing up to 20% by mol of ethylene or one or more alpha olefins of formula CH 2 ═CHT 1 .
36 . The process according to claim 20 , wherein the ethylene resin comprises from 30% to 70% by weight of an ethylene copolymer having from 4% by mol to 60% by mol of comonomers of formula CH 2 ═CHT 1 , and optionally up to 20% by mol of a non conjugated diene.
37 . The process according to claim 20 , wherein the propylene resin comprises a propylene homopolymer.
38 . The process according to claim 20 , wherein the ethylene resin comprises an ethylene 1-butene copolymer.