| 摘要 |
PROBLEM TO BE SOLVED: To provide a method of modifying a Ziegler-Natta catalyst so that it can produce an olefinic polymer having a small number of undesirable short-chain branches.SOLUTION: In the method of modifying a Ziegler-Natta catalyst, the Ziegler-Natta catalyst obtained by using a magnesium compound and a quadrivalent titanium compound is heated at 0-100°C in the presence of an organoaluminum compound represented by following formula (c) to be modified to a catalyst satisfying following conditions (1) to (3). (c): AlXR(OR)(wherein Xis a halogen atom; and Rand Rare each 1-10C hydrocarbon group). (1): The concentration of Ti atoms on the catalyst surface obtained by XPS measurement is larger than before the treatment. (2): The ratio of the concentration of Tion teh catalyst surface to the concentration of Ti(Ti/Ti) thereon obtained by the XPS measurement is larger than before the treatment. (3): The ratio of the content of Al atoms in the catalyst to the content of Ti atoms in the catalyst (Al/Ti) obtained by elemental analysis is larger than before the treatment. |
