| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for producing a polyolefin that gives few amount of low-molecular-weight components. SOLUTION: The method for producing a polyolefin includes polymerizing an olefin by carrying out the following steps (1) and (2) one by one, in the presence of a polymerization catalyst prepared by heating at 150-400°C, heating under gas stream, heating under a reduced pressure or azeotropic dehydration with an inactive organic solvent, to obtain a polymer having a weight-average molecular weight of 50,000-2,000,000 and 2 wt.% or less of low-molecular-weight components having a molecular weight of hundredth or less of the weight average molecular weight. In step (1), an ion-exchangeable phyllosilicate of a smectite group is treated in the presence of water and/or an organic solvent with a compound A that is composed of a cation including a chromium atom and at least one anion selected from the group consisting of halogen ions and anions of inorganic acids and organic acids and is a salt soluble in water or an acidic aqueous solution. In step (2), the product obtained in step (1) is treated with an organic metal compound B containing a metal atom of the group 1 or group 2 of the periodic table. COPYRIGHT: (C)2010,JPO&INPIT
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