To obtain a polyisoolefin compd. having a high mol.wt. at low cost by (co)polymerizing an isoolefin compd. in the presence of a metallocene initiator system having a specified compsn. under controlled pressure and temp.
An initiator system comprising a compd. represented by the formula Cp'2AlR3 (wherein Cp' represents an optionally substd. cyclopentadienyl; and R3 represents a 1-10C alkyl or a 3-10C cycloalkyl) [e.g. (CP)2Al(CH3)] and a compd. represented by the formula BR4R5R6 (wherein R4, R5, and R6 may be the same as R3 or a 6-18C aryl optionally substd. with a halogen) [e.g., (C6F5)3B] is provided. An isoolefin compd. represented by the formula CH2=CR1 R2 (wherein R1 represents methyl; and R2 is the same as R3) (e.g. isobutene) is polymerized optionally together with a 4-20C diene compd. and/or a 4-20C cation-polymerizable unsatd. compd. in the presence of this initiation system under a pressure of 0.1 to 100 bar and a temp. of -100 to +200°C to obtain a polyisoolefin compd.
MANFUREETO BOHOMAN
DEIBITSUDO EMU DOOSON
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