| 摘要 |
<p>1389979 Ring-opening polymerization catalyst SHELL INTERNATIONALE RESEARCH MAATSCHAPPIJ BV 12 April 1973 [14 April 1972] 17660/73 Heading C3P Cyclic olefins having 5 or 7-12 carbon atoms in the ring are polymerized in the liquid phase using a catalyst comprising a hydride and/or hydrocarbyl of a non-transition metal and a tungsten compound of the formula (Hal) m - W-(OR) n , where the Hal are halogen atoms, the R are aryl groups at least one of which is substituted in at least one of the positions ortho to the oxygen with a sterically hindering organic group, each of m and n is at least 1, and m + n is 5 or 6. Suitable sterically hindering groups are alkyl groups having a secondary or tertiary carbon atom which is joined directly or through an oxygen or nitrogen atom to the aryl group. The catalyst may be formed in situ or may be pre-formed with or without a small portion of the monomer. Polymerization may be carried out in a solvent such as toluene or in bulk, preferably at 40 to 80‹ C. An open chain monounsaturated or non-conjugated polyunsaturated compound such as pentene-1 or hexadiene-1,5 may be used as a molecular weight regulator. Exemplified catalysts are derived from EtAlCl 2 and tungsten tetrachloride bis-(2-isopropylphenoxide), tungsten dichloride tetrakis-(2- isopropylphenoxide) and tungsten dichloride tetrakis-(2,6-diisopropylphenoxide). They are used to polymerize cyclopentene.</p> |
