Process for polymerizing a polymerizable olefin and catalyst therefor
The present invention generally relates to a process that copolymerizes two or more polymerizable olefins, and to cataclyst comprising a metal-ligand complex (precatalyst). The present invention also generally relates to ligands useful for preparing the metal-ligand complex.
1. A process for copolymerizing polymerizable olefins, the process comprising contacting together ethylene, a (C 3 -C 40 ) olefin comonomer, a first aprotic solvent, and a catalytic amount of a catalyst, wherein the catalyst is prepared before the contacting step as a solution in a second aprotic solvent and wherein the catalyst comprises a mixture or reaction product of a metal-ligand complex and at least one activating co-catalyst; wherein the metal-ligand complex is at least one metal-ligand complex (1) or (2):
(2′,2″-(propane-1,3-diylbis(oxy))bis(3-(3,6-di-tert-butyl-9H-carbazol-9-yl)-5′-fluoro-5-(2,4,4-trimethylpentan-2-yl)biphenyl-2-ol)dimethyl-hafnium, (1); or (2′,2″-(propane-1,3-diylbis(oxy))bis(3-(3,6-di-tert-butyl-9H-carbazol-9-yl)-5′-chloro-5-(2,4,4-trimethylpentan-2-yl)biphenyl-2-ol)dimethyl-hafnium, (2);
wherein the ratio of total number of moles of the at least one metal-ligand complex to total number of moles of the at least one activating co-catalyst is from 1:10,000 to 100:1;
wherein the contacting is performed under olefin polymerizing conditions that include a reaction temperature of from 30 degrees Celsius to 300 degrees Celsius and prepares a polyolefin copolymer comprising repeat units comprising residuals of ethylene and the (C 3 -C 40 )olefin comonomer;
wherein the process forms reactive chains (in situ) and is characterized by a reaction rate constant k 11 for adding the ethylene to a first reactive chain end comprising an ethylene residual; a reaction rate constant k 12 for adding the (C 3 -C 40 )olefin comonomer to a second reactive chain end comprising an ethylene residual; and a reactivity ratio r 1 equal to k 11 divided by k 12 of less than 20 (r 1 =k 11 /k 12 <20); and
wherein the first and second aprotic solvents comprise (C 2 -C 40 )alkane solvents, (C 3 -C 40 )cycloalkane solvents or mixtures thereof.
2. A ligand, wherein the ligand is the ligand (Q1) or (Q2): 2′,2″-(propane-1,3-diylbis(oxy))bis(3-(3,6-di-tert-butyl-9H-carbazol-9-yl)-5′-fluoro-5-(2,4,4-trimethylpentan-2-yl)biphenyl-2-ol, (Q1); or 2′,2″-(propane-1,3-diylbis(oxy))bis(3-(3,6-di-tert-butyl-9H-carbazol-9-yl)-5′-chloro-5-(2,4,4-trimethylpentan-2-yl)biphenyl-2-ol, (Q2).