Reference

Tetra(neophyl) zirconium

Tetra(neophyl) zirconium. Setterquist, Robert Alton (du Pont de Nemours, E. I., and Co., USA). U.S. US 4017525 12 Apr 1977, 14 pp. Division of U.S. 3,932,307. (English). (United States of America). CODEN: USXXAM. CLASS: IC: C07F007-00. NCL: 260429300. APPLICATION: US 75-471813 20 May 1975. DOCUMENT TYPE: Patent CA Section: 35 (Synthetic High Polymers) Tetraneophylzirconium (I) [60530-40-7] reaction product with activated alumina is used as a polymn. catalyst to produce linear, high-mol.-wt. polyolefins of high crystallinity. Thus, I was prepd. via the Grignard reaction of neophyl chloride [515-40-2] with ZrCl4 [10026-11-6], dissolved in Decalin, and treated with a mineral oil suspension of activated alumina for 21 h at 25.degree. under stirring. Use of the obtained catalyst in a continuous polymn. process conducted at 2250 psi, 250.degree., ethylene feed rate 200 g/h, and catalyst concn. 9010-79-1 and 60530-40-7 are also in the experiment. (with respect to Zr) 2.0 .times. 10-5 M gave a polyethylene (II) [9002-88-4] prodn. of 177 g/h, compared to 167 g/h in the presence of a tetrabenzylzirconium-Al2O3 catalyst. The activity of I catalyst was 1.5 times that of the benzyl analog. The II obtained in the presence of I catalyst had melt flow (ASTM 1238-65T, condition E) 2.8 dg/min and d. (ASTM D 792-64 T) 0.960 g/cc. Removal of catalyst residues is unnecessary on use of I. .