Process for polymerizing an aromatic vinyl compound and a catalyst therefor

Claim 2

A catalyst for polymerizing an aromatic vinyl compound, the catalyst having the formula (1): ##STR5## where M is an element of Group IVa; X 1 is a halogen; R 1 , R 2 , R 3 , R 4 , R 5 , R 6 and R 7 are independently hydrogen or an alkyl group having 1 to 6 carbon atoms; R 8 is hydrogen or an alkyl group having 1 to 5 carbon atoms; m is an integer of from 1 to 6; and n is an integer of from 4 to 60.

Claim 3

The catalyst according to claim 1, in which the catalyst is a complex obtained by isolating a reaction product of a compound of a transition metal of Group IVa with an alumoxane.

Claim 4

The catalyst according to claim 1, wherein R 1 to R 8 are each independently hydrogen or methyl.

Claim 5

The catalyst according to claim 1, which is methylenebis (cyclopentadienyl)-titanium-methylalumoxane (tetramer) or methylenebis (cyclopentadienyl)-titanium-methylalumoxane (16-mer).

Claim 6

A process of preparing a catalyst having the formula (I): ##STR6## wherein M is an element of Group IV a; X 1 is halogen; R 1 -R 7 are each hydrogen or an alkyl group having 1 to 6 carbon atoms; R 8 is hydrogen or an alkyl group having 1 to 5 carbon atoms; m is an integer of from 1 to 6; and n is an integer of from 4 to 60; which process comprises: a) reacting an effective amount of a transition metal compound of the formula (II): ##STR7## wherein M is an element of Group IVa; X 1 and X 2 are each halogen; R 1 -R 6 are each hydrogen or an alkyl having from 1 to 6 carbon atoms; and m is an integer of from 1 to 5, with an effective amount of an alumoxane, to form said catalyst; and b) recovering said catalyst.

Claim 7

A process of preparing a catalyst having the formula (I): ##STR6## wherein M is an element of Group IV a; X 1 is halogen; R 1 -R 7 are each hydrogen or an alkyl group having 1 to 6 carbon atoms; R 8 is hydrogen or an alkyl group having 1 to 5 carbon atoms; m is an integer of from 1 to 6; and n is an integer of from 4 to 60; which process comprises: a) reacting an effective amount of a transition metal compound of the formula (II): ##STR7## wherein M is an element of Group IVa; X 1 and X 2 are each halogen; R 1 -R 6 are each hydrogen or an alkyl having from 1 to 6 carbon atoms; and m is an integer of from 1 to 5, with an effective amount of an alumoxane, to form said catalyst; and b) recovering said catalyst.

Claim 8

The process according to claim 5, wherein the transition metal compound and said alumoxane are used in the ratio of from about 1 to 10 moles of said transition metal compound per mole of said alumoxane.