Control of a solution process for polymerization of ethylene

A process for the solution polymerization of high molecular weight polymers of alpha olefins selected from the group consisting of homopolymers of ethylene and copolymers of ethylene and C.sub.3-12 alpha olefins at a temperature from 105.degree. to 320.degree. C. and a pressure from 4-20 MPa, said process comprising feeding to a tubular reactor kept under non-isothermal conditions or a series of reactors which operate under different conditions, monomer, selected from the group consisting of ethylene and mixtures of ethylene and at least one C.sub.3-12 alpha olefin, a hydrocarbon solvent and a catalyst;

• wherein said catalyst is prepared by in-line mixing at a temperature of less than 30.degree. C.:
• (i) a catalyst precursor prepared by the in-line mixing at a temperature of less than 30.degree. C. of a mixture consisting of:
• (a) MgR.sup.1.sub.2 and AIR.sup.2.sub.3 wherein each R.sup.1 and R.sup.2 is the same or different and is a C.sub.1-10 alkyl radical;
• (b) a reactive halide;
• and
• (c) titanium tetrachloride;
• to provide a molar ratio of halide to magnesium from 2.2 to 2.4;
• magnesium to titanium of 5;
• and aluminum to titanium of 0.9;
• with
• (ii) a catalyst activator prepared by in-line mixing at a temperature of less than 30.degree. C. a composition consisting of:
• (d) a first component which is an aluminum alkyl of the formula AIR.sub.3 wherein R is an alkyl radical of the 2-8 carbon atoms;
• with
• (e) an alcohol of the formula R.sup.4 OH wherein R.sup.4 is a C.sub.1-20 alkyl radical in a ratio of alcohol to aluminum from 0.1 to 1.