Reference

Alkyl borates as propylene polymerization catalyst modifiers

Alkyl borates as propylene polymerization catalyst modifiers. Karayannis, Nicholas M.; Lee, Sam S. (Amoco Chem. Corp., Naperville, IL 60566, USA). Makromol. Chem., Rapid Commun., 6(1), 43-7 (English) 1985. CODEN: MCRCD4. ISSN: 0173-2803. DOCUMENT TYPE: Journal CA Section: 35 (Chemistry of Synthetic High Polymers) B(OMe)3 [121-43-7], B(OEt)3 [150-46-9], B(OPr)3 [688-71-1], and B(OBu)3 [688-74-4] incresed catalyst activity by 30-40% and stereospecificity by 30-40% at relatively low levels (B-Ti 0.) when used with Et2AlCl [96-10-6] in the polymn. of C3H6. The further addn. of (Bu3Sn)2S [4808-30-4] further improved activity (by 35%) and stereospecificity. Stereospecificity improvement in the order B(OMe)3 < B(OEt3) < B(OPr)3 < B(OBu)3 indicates steric hindrance at the active polymn. site, owing to formation of Al(OR), and possibly Ti(OR), groups.

Olefin polymerization catalyst components

Olefin polymerization catalyst components. (Mitsubishi Petrochemical Co., Ltd., Japan). Jpn. Kokai Tokkyo Koho JP 58117206 A2 12 Jul 1983 Showa, 10 pp. (Japanese). (Japan). CODEN: JKXXAF. CLASS: IC: C08F010-00; C08F004-02; C08F004-64. APPLICATION: JP 81-214953 28 Dec 1981. DOCUMENT TYPE: Patent CA Section: 35 (Chemistry of Synthetic High Polymers) Highly active, stereospecific title solid components were prepd. from (A) a Mg halide, (B) RR1R2CCO2R3 (R = H, C1-12 hydrocarbyl; R1,R2, R3 = C1-12 hydrocarbyl), (C) M(OR5)mR6n-m (M = Ti, B; R5 = C1-20 hydrocarbyl; R6 = halogen; n = valency of M; 1 ￡ m ￡ n), and a Ti halide. Thus, 20 g MgCl2 was vibration-milled with 3.1 g B(OEt)3 [150-46-9], then with 12.1 g Et a-phenylbutyrate [119-43-7]. The milled product (~6 g) was combined with 50 mL ClCH2CH2Cl and 50 mL TiCl4 and heated at 80° for 2 h, then freed from the supernatant, treated again with TiCl4, and washed with heptane to give a solid catalyst component. Polymn. of propylene in the presence of this catalyst component, triisobutylaluminum [100-99-2], ethylaluminum sesquichloride [12075-68-2], and Me p-toluate [99-75-2] in heptane at 70° showed catalyst efficiency 52.2 ′ 104 g polymer/g Ti, atactic polymer formation 0.83%, product isotacticity index 96.5%, and melt index 2.1 g/10 min.