FREEZING FOR POLYETHY WITH POLYETHYLES AND ENCLOSURES OEVER 500 000

摘要

1451292 Polyethylene production using Ziegler catalyst RUHRCHEMIE AG 9 Dec 1974 [11 Dec 1973] 53141/74 Heading C3P Polyethylene having a molecular weight above 500,000 is obtained by polymerizing ethylene at 30‹ to 130‹ C. in the presence of a Ziegler catalyst comprising (A) a titanium III halide, (B) an organoaluminium compound and (C) an alcohol, the molar raio of (A) to (B) being between 5 : 1 and 1 : 5, the proportion of (C) being 2 to 10 moles per kg. of (A) + (B), and the ethylene monomer containing less than 5 p.p.m. oxygen. Component (C) may be mono- or polyhydric alcohol. The examples refer to batch or continuous ethylene polymerization using a suitably pure monomer, a purified hydrocarbon fraction as diluent, and a catalyst comprising (A) TiCl 3 obtained from TiCl 4 + Et 2 AlCl, (B) Et 2 AlCl and (C) butanol. The minimal oxygen content in the monomer feed ensures that films and deposits on the polymerization vessels and stirrers are largely eliminated.