| 摘要 |
U.S. 18,188 A new catalyst system for alphaolefin type polymerizations, includes at least one hindered alkyl metal amide compound having the formula R'2YNR2 in combination with a Group IVB-VIII transition metal compound on a support and at least one Lewis base wherein R is selected from the group consisting of C3 to C20 bulky alkyl, cycloalkyl, aralkyl, aryl and substituted aryl groups or R2N is a hindered cyclic amide group; R' is selected from the group consisting of C1 to C20 primary alkyl, secondary alkyl, tertiary alkyl, neopentyl alkyl, branched alkyl, cycloalkyl or aralkyl groups, and Y is selected from the group consisting of aluminum, galium or indium. The catalyst system provides polymers having increased isotactic stereoregularity as well as lower catalyst residue. |
