Storing solid olefin polymerisation catalyst without loss of activity - by storing solid Ziegler-Natta catalyst components contg. titanium, magnesium, halogen, and electron donor under carbon di:oxide

摘要

A process for the storage of olefin polymerisation catalyst components comprises storing solid Ziegler-Natta catalyst components (I) contg. mainly Ti, Mg, a halogen and an electron donor under CO2 or an inert gas contg. CO2. ADVANTAGE - The process enables (I) to be kept for a long time, even as a dry powder, with no adverse effects on catalyst properties, irrespective of the ambient temp. (esp. at 30 deg.C or above). In an example, a mixt. of 3 g anhydrous MgCl2, 15 ml decane and 15 ml 2-ethyl-hexanol was heated for 2 hrs. at 130 deg.C to give a soln., then 0.7 g phthalic anhydride was added and dissolved in 1 hr. at 130 deg.C, after which the soln. was added over 1 hr. to 120 ml TiCl4, which has been stored at -20 deg.C. The soln. was heated to 110 deg.C in 4 hrs., then 2.2 g di-n-butyl phthalate was added and the mixt. was stirred for 2 hrs. at this temp.; the solid was filtered hot, re-suspended in 120 ml TiCl4, heated for 2 hrs at 120 deg.C, filtered off (hot), washed at 120 deg.C with decane and hexane until the washings contained no Ti cpds., and dried to give catalyst component (I) contg. 2.2. wt.% Ti and 7.8 wt.% hexane. In polymerisation experiments, with propylene (2 hrs. at 70 deg.C and 0.8 MPa, in the presence of 1.5 l hexane, 3 mmoles Et3Al, 0.45 mmole Ph2Si(OMe)2 and 150 ml hydrogen), the catalytic activity of freshly-prepn. (I) was 8700 g PP/g (I) and the polymer obtd. contained 0.54 wt.% hexane-solubles. When the catalyst was sealed under CO2 in transparent glass ampoules and then stored at 40 deg.C in the light, corresp. results after storage times of 14 days, 31 days, and 3 months were 8900, 8800, 8800, and 0.55, 0.56, 0.53 respectively. (cf. 8000, 5700, 4300 and 0.91, 1.40, 2.10 if (I) was stored under nitrogen instead of CO2).