A process for the preparation of a random propylene copolymer comprising polymerising propylene and at least one C2-10 alpha olefin (especially ethylene) in the presence of a catalyst; wherein said catalyst comprises: (i) a complex of formula (I): wherein M is zirconium or hafnium; each X is a sigma ligand; L is a divalent bridge selected from —R′
2
C—, —R′
2
C—CR′
2
—, —R′
2
Si—, —R′
2
Si—SiR
2
—, —R′
2
Ge—, wherein each R′ is independently a hydrogen atom, C1-C20-hydrocarbyl, tri(C1-C20-alkyl)silyl, C6-C20-aryl, C7-C20-arylalkyl or C7-C20-alkylaryl; each R
1
is a C4-C20 hydrocarbyl radical branched at the β-atom to the cyclopentadienyl ring, optionally containing one or more heteroatoms belonging to groups 14-16, or is a C3-C20 hydrocarbyl radical branched at the β-atom to the cyclopentadienyl ring where the β-atom is an Si-atom; n is 0-3; each R
18
is the same or different and may be a C1-C20 hydrocarbyl radical optionally containing one or more heteroatoms belonging to groups 14-16; each R
4
is a hydrogen atom or a C1-6-hydrocarbyl radical; each W is a 5 or 6 membered aryl or heteroaryl ring wherein each atom of said ring is optionally substituted with an R
5
group; each R
5
is the same or different and is a C1-C20 hydrocarbyl radical optionally containing one or more heteroatoms belonging to groups 14-16; and optionally two adjacent R
5
groups taken together can form a further mono or multicyclic ring condensed to W optionally substituted by one or two groups R
5
; and (ii) a cocatalyst comprising an organometallic compound of a Group 13 metal.
一种制备随机
丙烯共聚物的方法,包括在催化剂的存在下聚合
丙烯和至少一种C2-10α烯烃(特别是
乙烯);其中所述催化剂包括:(i)式(I)的配合物:其中M为
锆或
铪;每个X为σ
配体;L为二价桥,选择自-R′2C-,-R′2C-CR′2-,-R′2Si-,-R′2Si-SiR2-,-R′2Ge-,其中每个R′独立地为氢原子,C1-C20-烃基,三(C1-C20-烷基)
硅基,C6-C20-芳基,C7-C20-芳基烷基或C7-C20-烷基芳基;每个R1为在
环戊二烯基β原子处分支的C4-C20烃基基团,可选地含有属于14-16族的一个或多个杂原子,或为在β原子处分支的C3-C20烃基基团,其中β原子为Si原子;n为0-3;每个R18相同或不同,可为C1-C20烃基基团,可选地含有属于14-16族的一个或多个杂原子;每个R4为氢原子或C1-6烃基基团;每个W为5或6元芳基或杂芳基环,其中所述环的每个原子可选地用R5基团取代;每个R5相同或不同,可为C1-C20烃基基团,可选地含有属于14-16族的一个或多个杂原子;并且可选地,相邻的两个R5基团可以共同形成一个进一步的单环或多环环,该环与W融合,可选地用一个或两个R5基团取代;以及(ii)一个共催化剂,包括第13族
金属的有机
金属化合物。