PURPOSE: To obtain a cycloolefin polymer with a mol.wt. suitable for its application by polymerizing a cycloolefin using a specific catalyst in the presence of a specific α-olefin in a controlled concn.
CONSTITUTION: A cycloolefin is polymerized using a catalyst comprising a compd. of a metal of group VIII [e g. bis(acetylacetonato)metal] and an organometallic compd. [e.g. an organoaluminum compd. of formula I or II (wherein R is a 1-3C hydrocarbon group; and n is 1-50)] in the presence of a 3-20C α-olefin (e.g. propylene or heptadecene) in a controlled concn. The mol.wt. of the resultant cycyloolefin polymer is controlled as desired by controlling the concn. of the α-olefin. A cycloolefin polymer formerly obtd. by using the above catalyst has too high a mol.wt., and a method for obtaining the polymer with a desired mol.wt., i.e., desired physical properties, moldability, etc., has been wanted.
ASANO MASAHIKO
OOKITA MASUMIZU
