METHOD FOR PRODUCING SYNDIOTACTIC PROPYLENE POLYMER

摘要

It is an object of the present invention to provide a process for producing a syndiotactic propylene polymer with high polymerization activity and high efficiency by a solution polymerization method without deposition of polymers (excluding a white state), and a production process capable of conducting the above production continuously, provided that these processes could not be attained conventionally. The present invention is:
a process for producing a syndiotactic propylene polymer having a syndiotactic pentad fraction (rrrr fraction), as measured by 13 C-NMR, of at least 85%, a melting point (Tm), as measured by DSC, of from 145°C to 170°C, and an intrinsic viscosity [·] of 0.1 to 10 dl/g, which process comprises a step (P 1 ) of solution polymerizing propylene singly or propylene and at least one monomer selected from ethylene and an ±-olefin having 4 to 10 carbon atoms at a polymerization temperature (T R ) of from 30°C to 250°C in an inert hydrocarbon solvent in the presence of an olefin polymerization catalyst which comprises;
(A) a bridged metallocene compound represented by the following formula (I), and
(B) at least one compound selected from
(b-1) an organoaluminum oxy compound,
(b-2) a compound capable of forming an ion pair by reacting with the metallocene compound (A), and
(b-3) an organoaluminum compound.
in which M is a titanium atom or the like, Q is a halogen atom or the like, j is an integer of 1 to 4, R a and R b may be identically or differently a single nuclear or polynuclear hydrocarbon residue capable of forming a sandwich structure together with M, Y is a carbon atom or a silicon atom, and R c and R d may be the same or different from each other, is selected from hydrogen, a hydrocarbon group and a silicon atom-containing group and further may be bonded each other to form a ring.