| 摘要 |
Catalyst and solid component of catalyst for the (co)polymerization of ethylene, comprising titanium, magnesium, chlorine, a protic organo-oxygenated compound Dp and a neutral aprotic electron-donor compound D, in the following molar ranges: Mg/Ti= 1.0-50; D/Ti= 1.0-15; Cl/Ti= 6.0-100; DP/D= 0.05-3; and a process for obtaining said component comprising the following steps in succession: (a) formation of a mixture and dissolution, in said electron-donor aprotic compound D, of a magnesium chloride and a titanium compound having formula (II): Tiv(OR3)aX(v-a) wherein each R3 independently represents a hydrocarbyl or acyl radical having from 1 to 15 carbon atoms; each X is selected from chlorine, bromine or iodine; ~v~ has the value of 3 or 4, and ~a~ is a number varying from 0 to ~v~, with a molar ratio between titanium and magnesium ranging from 1/1 to 50/1; (b) partial separation of the compound D from said mixture prepared in step (a) until a residue is obtained, solid at room temperature, wherein the D/Ti ratio ranges from 1.5 to 40, (c) formation of a suspension of said solid organo-oxygenated protic compound DP, in such a quantity that the molar ratio DP/D ranges from 0.1 to 1.2 and maintaining the mixture until equilibrium is reached, to form the desired solid component of catalyst. |
