PURPOSE: To keep the temp. rise during polymn. low and obtain an isobutylene polymer which gives a cured item with a high hardness by conducting a specific cationic polymn. in a solvent contg. a specific monohalogenated hydrocarbon.
CONSTITUTION: This isobutylene polymer is produced by mixing an isobutylene- contg. cationically polymerizable monomer, a compd. represented by the formula [wherein R1 is an arom. group or an optionally substd. aliph. hydrocarbon group; R2 and R' are each an optionally substd. monovalent hydrocarbon group provided when R1 is an aliph. hydrocarbon group, then R2 and R3 are not simultaneously H; X is a halogen, R4COO (wherein R4 is H or a 1-5C alkyl), or R5O (wherein R5 is H or a 1-5C alkyl); and (n) is 1-8], a Lewis acid, and an electron donor having a donor number of 15-50 at -100°C to 0°C in a solvent contg. a 3-8C prim. and/or sec. monohalogenated hydrocarbon and subiecting the resultant mixture to cationic polymn. Thus, the temp. rise during polymn. can be kept lower than the case when a 2C or lower monohalogenated hydrocarbon is used, and a cured item with high strengths can be obtd.
FUJISAWA HIROSHI
CHIBA TAKESHI
DEGUCHI YOSHIKUNI
YONEZAWA KAZUYA
