Process for production of polyissolefins by means of novel initiator systems

Prepn. of polyisoolefins comprises soln., suspension or gas phase polymerisation of isoolefins of formula CH2=CR R ; in which R = Me; and R = 1-10C alkyl or 3-10C cycloalkyl; and opt. (un)conjugated 4-20C dienes and/or 4-20C mono- or poly-unsatd. cpd(s). capable of cationic polymerisation. Polymerisation is carried out at -100 to +200 degrees C and 0.1-100 bar in the presence of an initiator soln. comprising hydrocarbons of formula R R R C-X (I) and an open-chain and/or cyclic aluminoxane cpd. of the formula (IIA) or (IIB), where X = halogen, SCN, CN, OH, OR ', OCOR ' or COOR '; R ' = 1-10C alkyl or 3-10C cycloalkyl; R , R , R = H, opt. X-substd. 1-10C alkyl, 3-10C cycloalkyl, 6-18C aryl, 2-10C alkynyl or 3-10C alkyne; R(SP>W-R = 1-12C alkyl; and m = 5-30. Also claimed is the initiator system comprising (I) and (IIA) or (IIB) per se. Pref. polymerisation is carried out at -100 to +100 degrees C and 1-50 bar. The (I) concn. is 10 to 10 mole/l and the molar ratio of (I) to (IIA) or (IIB) is 1:100 to 10 :1.