Control of a solution process for polymerization of ethylene
First Claim
1. 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 C3-12 alpha olefins at a temperature from 105°
- to 320°
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 C3-12 alpha olefin, a hydrocarbon solvent and a catalyst;
wherein said catalyst is prepared by in-line mixing at a temperature of less than 30°
C.;
(i) a catalyst precursor prepared by the in-line mixing at a temperature of less than 30°
C. of a mixture consisting of;
(a) MgR12 and AIR23 wherein each R1 and R2 is the same or different and is a C1-10 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°
C. a composition consisting of;
(d) a first component which is an aluminum alkyl of the formula AIR3 wherein R is an alkyl radical of the 2-8 carbon atoms;
with(e) an alcohol of the formula R4 OH wherein R4 is a C1-20 alkyl radical in a ratio of alcohol to aluminum from 0.1 to 1.
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Abstract
A solution process for the preparation of high molecular weight polymers of alpha-olefins selected from the group consisting of homopolymers of ethylene and copolymers of ethylene and C3 -C12 higher alpha-olefins is disclosed. Ethylene and/or mixtures of ethylene and C3 -C12 higher alpha-olefins are polymerized under non-isothermal conditions in a tubular reactor or in a system of reactors which operate under different conditions, in the presence of a catalytic amount of a titanium-containing coordination catalyst in an inert solvent at a temperature in excess of 105° C. The improvement is characterized in that:
(a) the catalyst is activated with a solution of a mixture of aluminum alkyl and alkoxy aluminum alkyl in inert solvent; and
(b) the process is controlled by adjusting the ratio of aluminum alkyl to alkoxy aluminum alkyl in the mixture of (a). The aluminum alkyl is of the formula AlRn X3-n and the alkoxy aluminum alkyl is of the formula AlR'"'"'m OR"3-m, in which each of R, R'"'"' and R" is alkyl or aryl of 1-20 carbon atoms, X is halogen, n is 2-3 and m is 0-3.
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Citations
1 Claim
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1. 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 C3-12 alpha olefins at a temperature from 105°
- to 320°
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 C3-12 alpha olefin, a hydrocarbon solvent and a catalyst;
wherein said catalyst is prepared by in-line mixing at a temperature of less than 30°
C.;(i) a catalyst precursor prepared by the in-line mixing at a temperature of less than 30°
C. of a mixture consisting of;(a) MgR12 and AIR23 wherein each R1 and R2 is the same or different and is a C1-10 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°
C. a composition consisting of;(d) a first component which is an aluminum alkyl of the formula AIR3 wherein R is an alkyl radical of the 2-8 carbon atoms;
with(e) an alcohol of the formula R4 OH wherein R4 is a C1-20 alkyl radical in a ratio of alcohol to aluminum from 0.1 to 1.
- to 320°
Specification