Process for producing substantially amorphous propylene-based polymers

Claim 1

A process for producing substantially amorphous propylene homopolymers or copolymers comprising contacting propylene, optionally in the presence of one or more olefins selected from the group consisting of ethylene, alpha-olefins of formula CH 2 ═CHR′ wherein R′ is a linear or branched, C 2 -C 10 alkyl or non conjugate diolefins containing up to 20 carbon atoms, under polymerization conditions with a catalyst system comprising: A) a titanium complex of formula (I): wherein: Ti is titanium; X is a nitrogen (N) or phosphorus (P) atom; Z is a C, Si or Ge atom; the groups R 1 , equal to or different from each other, are selected from the group consisting of hydrogen, 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 and C 7 -C 20 arylalkyl optionally containing Si or heteroatoms belonging to groups 13 or 15-17 of the Periodic Table of the Elements, or two R 1 groups together form a C 4 -C 7 ring; Y 1 is an atom selected from the group consisting of NR 7 , oxygen (O), PR 7 or sulfur (S), wherein the group R 7 is selected from the group consisting of linear or branched, saturated or unsaturated, C 1 -C 20 alkyl, C 6 -C 20 aryl and C 7 -C 20 arylalkyl radicals; the groups R 2 and R 3 , equal to or different from each other, are selected from the group consisting of hydrogen, halogen, —R, —OR, —OCOR, —OSO 2 CF 3 , —SR, —NR 2 and —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; two R groups can also form a saturated or unsaturated C 4 -C 7 ring, or R 2 and R 3 form a condensed aromatic or aliphatic C 4 -C 7 ring that can be substituted with one or more R 9 groups, wherein R 9 is selected from the group consisting of halogen, —R, —OR, —OCOR, —OSO 2 CF 3 , —SR, —NR 2 and —PR 2 , wherein R has the meaning reported above, or two vicinal R 9 groups together form a condensed aromatic or aliphatic C 4 -C 7 ring; the groups R 8 , R 4 and R 5 , equal to or different from each other, are selected from the group consisting of hydrogen, halogen, —R, —OR, —OCOR, —OSO 2 CF 3 , —SR, —NR 2 and —PR 2 , wherein R has the meaning reported above, or R 8 and R 4 , R 4 and R 5 , or R 5 and R 8 together form a condensed C 4 -C 7 ring that can be substituted with one or more R groups; the group R 6 is selected from the group consisting of a linear or branched, saturated or unsaturated C 1 -C 20 alkyl, C 6 -C 20 aryl and C 7 -C 20 arylalkyl radical, optionally containing heteroatoms belonging to groups 13 or 15-17 of the Periodic Table of the Elements; the substituents L, equal to or different from each other, are monoanionic sigma ligands selected from the group consisting of hydrogen, halogen, —R, —OR, —OCOR, —OSO 2 CF 3 , —SR, —NR 2 and —PR 2 , wherein R has the meaning reported above; Y 2 is selected from the group consisting of CR 8 or Y 1 ; and m is 0 or 1; when the group Y 2 is a CR 8 group m is 1 and the 6 membered ring formed is an aromatic benzene ring; when Y 2 is different from CR 8 m is 0 and the carbon atom bonding the R 4 group is directly bonded to the cyclopentadienyl ring and the ring formed is a 5 membered ring; and (B) an activating cocatalyst.