| 摘要 |
<p>Polymerisation of olefins CH2CHR11, where R11 is 1-8C alkyl, at 20-80, pref. 40-60 degrees C, and at 40 bars, is effected using a catalyst system comprising (a) catalyst prepd. by reacting Mg, monohalogenated hydrocarbons and TiCl4; (b) cocatalyst from cpds. AlR111, where R111 is 1-12C alkyl, such that cocatalyst to Ti mole ratio is 1-50; (c) >=1 electron-donating cpd(s). The catalyst (a) is prepd. between -20 and 150 degrees C with monohalogenated hydrocarbon to Mg mole ratio 0.5-10, pref. 2-4, and TiCl4 to Mg mole ratio 0.01-0.5, pref. 0.05-0.25. Catalyst (a) is also prepd. in the presence of Mg activators such as iodides or alcoholates of metals in sub-gps. Ia, IIa, IIIa and IVa, partic. an alkyl titanate, in molar quantities 10% of the TiCl4. Catalyst (a) is further prepd. in the presence of electron-donators such as various ethers or esters, or organic P cpds., the electron-donator to TiCl4 mole ratio being 0.05-2, pref. 0.5-1.2. The electron-donators in (c) are aromatic esters or ethers such as ethyl benzoate, phenylethylether or ethyl p-methoxybenzoate, with donator to cocatalyst molar ratio 0.05-5, pref. 0.1-0.4. They are pref. pre-mixed with the cocatalyst. The system can be partic. used for the homopolymerisation of propylene or its copolymerisation with less than 10 wt.% of another olefin. The polymers usually have a mol. wt. of 50,000-1,000,000. The polymers can be used for the usual applications of thermoplastics. They can have a crystalline content >=70%.</p> |
