Reactor continuity
AssigneeNOVA Chemicals (International) S.A.
InventorsLee Douglas Henderson, Peter Phung Minh Hoang, Ian Ronald Jobe, Xiaoliang Gao
Life of this patent
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Abstract
A supported catalyst system comprising a phosphinimine ligand containing catalyst on an alumina support treated with a metal salt has improved reactor continuity in a dispersed phase reaction in terms of initial activation and subsequent deactivation. The resulting catalyst has a lower consumption of ethylene during initiation and a lower rate of deactivation. Preferably the catalyst is used with an antistatic agent.
Claims6
A catalyst system having an activity greater than 1,500 g of polymer per gram of supported catalyst per hour normalized to 1,379 kPag (200 psig) of ethylene partial pressure and a temperature of 90° C. in the presence of 1-hexene comonomer. and a kinetic profile for a plot of ethylene consumption in standard liters of ethylene per minute against time in minutes, at a reaction pressure of 1,379 kPag (200 psig) and 90° C., corrected for the volume of ethylene in the reactor prior to the commencement of the reaction, in a 2 liter reactor over a period of time from 0 to 60 minutes is such that the ratio of the maximum peak height over the first 10 minutes to the average ethylene consumption from 10 to 60 minutes taken at not less than 40 data points, is less than 2.5, comprising:
- (i) an alumina support having an average particle size from 10 to 150 microns, a surface area greater than 100 m2/g, and a pore volume greater than 0.3 ml/g impregnated with
- (ii) at least a 1 weight % based on the weight of alumina of Zr(SO4)2.4H2O, based on the weight of the support of said salt;
- (iii) from 10 to 60 weight % of an aluminum activator based on the weight of said alumina support said activator having the formula:
- R122AlO(R12AlO)qAlR122
- wherein each R12 is independently selected from the group consisting of C1-20 hydrocarbyl radicals and q is from 3 to 50;
- and
- (iv) from 0.1 to 30 weight % of a phosphinimine catalyst of the formula:
- wherein M is a group 4 metal having an atomic weight less than 179;
- PI is a phosphinimine ligand of the formula
- wherein each R21 is independently selected from the group consisting of a hydrogen atom;
- a halogen atom;
- C1-10 hydrocarbyl radicals which are unsubstituted by or further substituted by a halogen atom;
- L is a monoanionic ligand selected from the group consisting of a cyclopentadienyl radical which is unsubstituted or substituted by a substituent selected from the group consisting of a C1-6 alkyl radical which is substituted by 2n+1 fluorine atoms where n is the number of carbon atoms in the alkyl radical, and a C6F5 radical which cyclopentadienyl ligand is optionally further substituted with up to two C3-6 alkyl radicals [in the 2 or 3 position relative to the fluorine containing substituent];
- Y is an activatable ligand;
- m is 1 or 2;
- q is 1;
- and p is an integer and the sum of m+q+p equals the valence state of M.
A process of making a catalyst system having an activity greater than 1,500 g of polymer per gram of supported catalyst per hour normalized to 1,379 kPag (200 psig) of ethylene partial pressure and a temperature of 90° C. in the presence of 1-hexene comonomer and a kinetic profile for a plot of ethylene consumption in standard liters of ethylene per minute against time in minutes, at a reaction pressure of 1379 kPag (200 psig) and 90° C., corrected for the volume of ethylene in the reactor prior to the commencement of the reaction, in a 2 liter reactor over a period of time from 0 to 60 minutes is such that the ratio of the maximum peak height over the first 10 minutes to the average ethylene consumption from 10 to 60 minutes taken at not less than 40 data points, is less than 2.5, comprising:
- (i) impregnating an alumina support having an average particle size from 10 to 150 microns, a surface area greater than 100 m2/g, and a pore volume greater than 0.3 ml/g with
- (ii) at least a 1 weight % aqueous solution of a metal salt selected from the group consisting of Zr(SO4)2-4H2O, to provide not less than 1 weight % based on the weight of the support of said salt;
- (iii) recovering the impregnated support;
- (iv) calcining said impregnated support in one or more steps at a temperature from 300° C. to 600° C. for a time from 2 to 20 hours in an inert atmosphere;
- (v) and either
- (a) contacting said calcined support with a hydrocarbyl solution containing an aluminum activator compound of the formula:
- R122AlO(R12AlO)qAlR122
- wherein each R12 is independently selected from the group consisting of C1-20 hydrocarbyl radicals and q is from 3 to 50 to provide from 10 to 60 weight % of said aluminum compound based on the weight of said calcined support;
- optionally, separating said activated support from said hydrocarbyl solution and contacting said activated support with a hydrocarbyl solution containing a single site catalyst as set out below to provide from 0.1 to 30 wt % of said catalyst ;
- or
- (b) contacting said support with a hydrocarbyl solution containing an aluminum activator compound of the formula:
- R122AlO(R12AlO)qAlR122
- wherein each R12 is independently selected from the group consisting of C1-20 hydrocarbyl radicals and q is from 3 to 50 to provide from 10 to 60 wt % of said activator and a single site catalyst of the formula:
- wherein M is selected from the group consisting of Ti, Zr and Hf;
- PI is a phosphinimine ligand of the formula:
- wherein each R21 is independently selected from the group consisting of a hydrogen atom;
- a halogen atom;
- C1-10 hydrocarbyl radicals which are unsubstituted by or further substituted by a halogen atom;
- L is a monoanionic ligand selected from the group consisting of a cyclopentadienyl radical which is unsubstituted or substituted by a substituent selected from the group consisting of a C1-6 alkyl radical which is substituted by 2n+1 fluorine atoms where n is the number of carbon atoms in the alkyl radical, and a C6F5 radical which cyclopentadienyl ligand is optionally further substituted with up to two C3-6 alkyl radicals [in the 2 or 3 position relative to the fluorine containing substituent];
- Y is an activatable ligand;
- m is 1 or 2;
- q is 1;
- and p is an integer and the sum of m+q+p equals the valence state of M to provide from 0.1 to 30 wt % of said catalyst.
- and
- (vi) recovering and drying the catalyst.
Dependencies are inferred from the claim text.