| abstract |
New olefin polymerization catalysts are disclosed which are prepared by mixing (A) the product obtained by contacting (1) a halogen-containing, or a halogen free, oxygen-containing organic compound of Ti, V or Zr, with (2) a hydrocarbon-insoluble solid product containing at least metal M and halogen and resulting from decomposition of a complex having the formula MX2.nAlRX2.pAlX3 (I) to M dihalide, or to a product containing M dihalide. In formula (I): M is Mg, Mn or Ca; X is chlorine or bromine in the case of MX2 and AlX3, and chlorine, bromine or alkoxy group in the case of AlRX2; R is a hydrocarbon radical containing from 1 to 20 carbon atoms; n is a number from 1 to 4, inclusive; p is a number from 0 to 1, inclusive; 1</=n+p</=4; with (B) an organometallic compound of a metal belonging to Groups I-III of the Mendelyeev Periodic Table. In the decomposition product of formula (I) M in the M dihalide has the same significance as M in formula (I). |