Thermoplastic elastomeric olefin polymers, method of production and catalysts therefor

A process for producing a polyolefin comprising the steps of:

• a) providing a metallocene reaction catalyst system comprising a cocatalyst and a transition metal compound of the formula (L)(L')M(X)(X') wherein:
• i) L and L' are hydrocarbon or substituted hydrocarbon ligands at least one of which is a substituted cyclopentadienyl ring and the other is a substituted cyclopentadienyl ring having the formula:
• ##STR10## where R.sub.1 is a, or R.sub.1 and R.sub.2 are, aryl or substituted aryl substituent(s) of the formula:
• ##STR11## where R.sub.4, R.sub.5, R.sub.6, R.sub.7 and R.sub.8 are hydrogen, halogen, aryl, hydrocarbyl, silahydrocarbyl or halohydrocarbyl substituents;
• and at least one of R.sub.2 or R.sub.3 are C.sub.1 -C.sub.20 alkyl, C.sub.1 -C.sub.20 alkylsilyl, or R.sub.2 and R.sub.3 are connected as a ring having at least three carbon atoms;
• ii) said ligands L and L' are selected to provide a preselected degree of steric hindrance to ligand rotation on their respective L-M and L'-M axes, said degree of hindrance being selected on the principle that sterically larger substituents provide a greater hindrance:
• iii) L and L are rotatable about their respective L-M and L'-M bond axes on a time scale slower than that of monomer insertion but faster than the time to construct a polymer chain, to alternate between two distinct states characterizable as rac-like and meso-like states wherein:
• (1) when L=L', said metallocene alternates between chiral rac and achiral meso states;
• and
• (2) when L.noteq.L', said metallocene alternates between a chiral rac-like state and a state which is chiral by virtue of the difference in substituents on the ligands, but meso-like in relative orientation of the two ligands including their substituents;
• iv) M is selected from a Group 3, 4 or 5 Transition metal, a Lanthanide or an Actinide;
• v) X and X' are uninegative hydride, halogen, alkoxide, hydrocarbyl, or halohydrocarbyl ligands;
• and
• b) contacting at least one olefin monomer with said reaction catalyst system for a time sufficient to catalytically polymerize said monomer(s) to form a polymer.

A transition metal compound useful alone or with a cocatalyst as a polymerization catalyst comprising a metallocene of the formula (L)(L')Sm (X)(X') wherein:

• a) L and L' are hydrocarbon or substituted hydrocarbon ligands;
• b) said ligands L and L' are selected to provide a proselected degree of steric hindrance to ligand rotation on their respective L-Sm and L'-Sm axes, said degree of hindrance being selected on the principle that sterically larger substituents provide a greater hindrance;
• c) L and L' are rotatable about their respective L-Sm and L'-Sm bond axes on a time scale slower than that of monomer insertion but faster than the time to construct a polymer chain, to alternate between two distinct states characterizable as rac-like and meso-like states wherein:
• i) when L=L', said metallocene alternates between chiral rac and achiral meso states;
• and
• ii) when L.noteq.L', said metallocene alternates between a chiral rac-like state and a state which is chiral by virtue of the difference in substituents on the ligands, but meso-like in relative orientation of the two ligands including their substituents;
• and
• d) X and X' are uninegative hydride, halogen, alkoxide, hydrocarbyl, or halohydrocarbyl ligands.

A polymerization process for producing a polyacrylate comprising the steps of:

• a) providing a polymerization compound of the formula (L)(L')M(X)(X'), alone or with a cocatalyst, wherein:
• (1) M is selected from Zr, or Hf or Sm;
• (2) L and L' are hydrocarbon or substituted hydrocarbon ligands;
• b) said ligands L and L' are selected to provide a preselected degree of static hindrance to ligand rotation on their respective L-M and L'-M axes, said degree of hindrance being selected on the principle that sterically larger substituents provide a greater hindrance;
• c) L and L' are rotatable about their respective L-M and L'-M bond axes on a time scale slower than that of monomer insertion but faster than the time to construct a polymer chain, to alternate between two distinct states characterizable as rac-like and meso-like states wherein:
• i) when L=L', said metallocene alternates between chiral rac and achiral meso states;
• and
• ii) when L.noteq.L', said metallocene alternates between a chiral rac-like state and a state which is chiral by virtue of the difference in substituents on the ligands, but meso-like in relative orientation of the two ligands including their substituents;
• d) X and X' are uninegative hydride, halogen, alkoxide, hydrocarbyl, or halohydrocarbyl ligands;
• and
• e) contacting an acrylate monomer with said compound or catalyst system for a time sufficient to catalytically polymerize said monomer to form a polymer.

In a method of polymerization of olefin monomers by contacting at least one olefin monomer with a metallocene catalyst/cocatalyst system, the improvement which comprises the steps of:

• a) providing a metallocene having a pair of hydrocarbon or substituted hydrocarbon ligands L and L' independently rotatable about a ligand-metal bond, at least one of which ligands is a substituted cyclopentadiene ring and the other is a substituted cyclopentadienyl ring having the formula:
• ##STR15## where R.sub.1 is a, or R.sub.1 and R.sub.2 are, aryl or substituted aryl substituent(s) of the formula;
• ##STR16## where R.sub.4, R.sub.5, R.sub.6, R.sub.7 and R.sub.8 are hydrogen, halogen, aryl, hydrocarbyl, silahydrocarbyl or halohydrocarbyl substituents;
• and at least one of R.sub.2 or R.sub.3 are C.sub.1 -C.sub.20 alkyl, C.sub.1 -C.sub.20 alkylsilyl, or R.sub.2 and R.sub.3 are connected as a ring having at least three carbon atoms;
• b) controlling the rate of rotation of said ligands by selecting ligand substituents to provide a preselected degree of static hindrance to ligand rotation on said ligand-metal bond, said degree of hindrance being selected on the principle that sterically larger substituents provide greater hindrance, said hindered rotation permitting said catalyst to alternate between two distinct states, wherein the rate of rotation between said states is less than the rate of monomer addition at the catalyst active site such that the lifetime of a given state is greater than the time required for insertion of a monomer unit to a growing polymer chain but shorter than the time required to form said polymer chain;
• c) said states are characterizable as rac-like and meso-like states wherein:
• i) when L=L' said metallocene alternates between chiral rac and achiral meso states;
• and
• ii) when L.noteq.L' said metallocene alternates between a chiral rac-like state and a state which is chiral by virtue of the difference in substituents on the ligands, but meso-like in relative orientation of the two ligands including their substituents;
• and
• d) reacting said monomer(s) for a time sufficient to produce an alpha olefin block polymer having a block index of greater than about 5, and elastomeric properties.