Arylphenoxy catalyst system for producing ethylene homopolymer or copolymers of ethylene and alpha-olefins

Abstract

The present invention relates to an arylphenoxy catalyst system producing an ethylene homopolymer or copolymers of ethylene and α-olefins, and a method of producing an ethylene homopolymer or copolymers of ethylene and α-olefins having a high molecular weight under a high temperature solution polymerization condition using the same. The catalyst system includes a group IV arylphenoxy-based transition metal catalyst and an aluminoxane cocatalyst or a boron compound cocatalyst. In the transition metal catalyst, a cyclopentadiene derivative and arylphenoxide as fixed ligands are located around the group IV transition metal, arylphenoxide is substituted with at least one aryl derivative and is located at the ortho position thereof, and the ligands are not crosslinked to each other. The catalyst includes an environmentally-friendly raw material, synthesis of the catalyst is economical, and thermal stability of the catalyst is excellent. It is useful for producing an ethylene homopolymer or copolymers of ethylene and α-olefins having various physical properties in commercial polymerization processes.

1 . An arylphenoxy-based transition metal catalyst of Formula 1, which includes a cyclopentadieyl group and an arylphenoxide group as fixed ligands bound to a transition metal, wherein the ligands are not crosslinked to each other:  
     
       
         
         
             
             
         
       
       wherein M is a group IV transition metal of the periodic table;  
       Cp is a cyclopentadienyl group forming an η 5 -bond with the transition metal, or a derivative thereof;  
       R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , and R 8  are independently a hydrogen atom, a halogen atom, a C 1 -C 20  linear or nonlinear alkyl group optionally substituted with one or more halogen atoms, a silyl group which contains the C 1 -C 20  linear or nonlinear alkyl group optionally substituted with one or more halogen atoms, a C 6 -C 30  aryl group optionally substituted with one or more halogen atoms, a C 7 -C 30  arylalkyl group optionally substituted with one or more halogen atoms, a C 1 -C 20  alkylalkoxy group optionally substituted with one or more halogen atoms, or a C 3 -C 20  alkyl-substituted siloxy group, or a C 6 -C 20  aryl-substituted siloxy group, optionally with the proviso that substituent groups may be optionally bonded to form rings;  
       Each X is independently selected from a halogen atom, a C 1 -C 20  alkyl group, a C 7 -C 30  arylalkyl group, an alkoxy group containing the C 1 -C 20  alkyl group, a C 3 -C 20  alkyl-substituted siloxy group, or an amido group having a C 1 -C 20  hydrocarbon group;  
       Y is a hydrogen atom, a halogen atom, a C 1 -C 20  linear or nonlinear alkyl group optionally substituted with one or more halogen atoms, a silyl group containing a C 1 -C 20  linear or nonlinear alkyl group optionally substituted with one or more halogen atoms, a C 6 -C 30  aryl group optionally substituted with one or more halogen atoms, a C 7 -C 30  arylalkyl group optionally substituted with one or more halogen atoms, a C 1 -C 20  alkylalkoxy group optionally substituted with one or more halogen atoms, a C 3 -C 20  alkyl-substituted siloxy group, or a C 6 -C 20  aryl-substituted siloxy group, an amido group or a phosphido group which has a C 1 -C 20  hydrocarbon group, or a C 1 -C 20  alkyl-substituted mercapto or nitro group; and  
       n is 1 or 2 depending on the oxidation state of the transition metal.  
     
   
   
       2 . The arylphenoxy-based transition metal catalyst as set forth in  claim 1 , wherein M is titanium, zirconium, or hafnium.  
   
   
       3 . The arylphenoxy-based transition metal catalyst as set forth in  claim 1 , wherein Cp is cyclopentadienyl, methylcyclopentadienyl, dimethylcyclopentadienyl, tetramethylcyclopentadienyl, pentamethylcyclopentadienyl, butylcyclopentadienyl, sec-butylcyclopentadienyl, tert-butylmethylcyclopentadienyl, trimethylsilylcyclopentadienyl, indenyl, methylindenyl, dimethylindenyl, ethylindenyl, isopropylindenyl, fluorenyl, methylfluorenyl, dimethylfluorenyl, ethylfluorenyl, or isopropylfluorenyl.  
   
   
       4 . The arylphenoxy-based transition metal catalyst as set forth in  claim 1 , wherein R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , and R 8  are independently selected from a hydrogen atom, a halogen atom, a methyl group, an ethyl group, an isopropyl group, a tert-butyl group, an amyl group, a trimethylsilyl group, a tert-butyldimethylsilyl group, a triphenylsilyl group, a phenyl group, a naphthyl group, a biphenyl group, a 2-isopropylphenyl group, a 3,5-xylyl group, a 2,4,6-trimethylphenyl group, a benzyl group, a methoxy group, an ethoxy group, an isopropoxy group, a tert-butoxy group, a trimethylsiloxy group, a tert-butyldimethylsiloxy group, a triphenylsiloxy group, a trifluoromethyl group, or a pentafluorophenyl group.  
   
   
       5 . The arylphenoxy-based transition metal catalyst as set forth in  claim 1 , wherein X is one or more of a halogen atom, a methyl group, an ethyl group, an isopropyl group, a tert-butyl group, an amyl group, a benzyl group, a methoxy group, an ethoxy group, an isopropoxy group, a tert-butoxy group, a trimethylsiloxy group, a tert-butyldimethylsiloxy group, a dimethylamino group, or a diethylamino group.  
   
   
       6 . The arylphenoxy-based transition metal catalyst as set forth in  claim 1 , wherein Y is a hydrogen atom, a halogen atom, a methyl group, an ethyl group, an isopropyl group, a tert-butyl group, an amyl group, a trimethylsilyl group, a tert-butyldimethylsilyl group, a triphenylsilyl group, a phenyl group, a naphthyl group, a biphenyl group, a 2-isopropylphenyl group, a 3,5-xylyl group, a 2,4,6-trimethylphenyl group, a benzyl group, a methoxy group, an ethoxy group, an isopropoxy group, a tert-butoxy group, a trimethylsiloxy group, a dimethylsiloxy group, a triphenylsiloxy group, a trifluoromethyl group, a pentafluorophenyl group, a dimethylamino group, a diethylamino group, an ethylmercaptan group, an isopropylmercaptan group, or a nitro group.  
   
   
       7 . An arylphenoxy catalyst system for producing an ethylene homopolymer or a copolymer of ethylene and an α-olefin, comprising: 
 a transition metal catalyst including a cyclopentadiene group and an arylphenoxide as fixed ligands around a transition metal, wherein the ligands are not crosslinked to each other; and    an aluminoxane or boron compound cocatalyst,    wherein the transition metal catalyst is:                          wherein M is a group IV transition metal of a periodic table;    Cp is a cyclopentadienel group capable of forming an η 5 -bond along with the central metal, or a derivative thereof;    R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , and R 8  are independently a hydrogen atom, a halogen atom, a C 1 -C 20  linear or nonlinear alkyl group optionally substituted with one or more halogen atoms, a silyl group which contains the C 1 -C 20  linear or nonlinear alkyl group optionally substituted with one or more halogen atoms, a C 6 -C 30  aryl group optionally substituted with one or more halogen atoms, a C 7 -C 30  arylalkyl group optionally substituted with one or more halogen atoms, a C 1 -C 20  alkylalkoxy group optionally substituted with one or more halogen atoms, a C 3 -C 20  alkyl-substituted siloxy group or a C 6 -C 20  aryl-substituted siloxy group, optionally with the proviso that substituent groups may be optionally bonded to form rings;    Each occurrence of X is independently selected from a halogen atom, a C 1 -C 20  alkyl group, a C 7 -C 30  arylalkyl group, the alkoxy group containing the C 1 -C 20  alkyl group, a C 3 -C 20  alkyl-substituted siloxy group, and an amido group having a C 1 -C 20  hydrocarbon group;    Y is a hydrogen atom, a halogen atom, a C 1 -C 20  linear or nonlinear alkyl group optionally substituted with one or more halogen atoms, a silyl group containing a C 1 -C 20  linear or nonlinear alkyl group optionally substituted with one or more halogen atoms, a C 6 -C 30  aryl group optionally substituted with one or more halogen atoms, a C 7 -C 30  arylalkyl group optionally substituted with one or more halogen atoms, a C 1 -C 20  alkylalkoxy group optionally substituted with one or more halogen atoms, a C 3 -C 20  alkyl-substituted siloxy group, a C 6 -C 20  aryl-substituted siloxy group, an amido group or a phosphido group which has the C 1 -C 20  hydrocarbon group, or a C 1 -C 20  alkyl-substituted mercapto or nitro group; and    n is 1 or 2 depending on the oxidation state of the transition metal.    
   
   
       8 . The arylphenoxy catalyst system as set forth in  claim 7 , wherein the aluminoxane cocatalyst is (—Al(R 9 )—O—) m  or (R 9 ) 2 Al—(—O(R 9 )—) p —(R 9 ) 2  having a molar ratio of the transition metal to aluminum of 1:50-1:5000; 
 wherein R 9  is a C 1 -C 4  alkyl group, and m and p are each an integer of from 5 to 20.    
   
   
       9 . The arylphenoxy catalyst system as set forth in  claim 7 , wherein the boron compound cocatalyst is N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate, triphenylmethylinium tetrakis(pentafluorophenyl)borate, or tris(pentafluoro)borane.  
   
   
       10 . The arylphenoxy catalyst system as set forth in  claim 7 , wherein the boron compound cocatalyst is mixed with aluminoxane or organic alkyl aluminum such that the molar ratio of the transition metal to the boron atom: an aluminum atom is 1:0.5-5:25-500.  
   
   
       11 . The arylphenoxy catalyst system as set forth in  claim 10 , wherein the aluminoxane is (—Al(R 9 )—O—) m  or (R 9 ) 2 Al—(—O(R 9 )—) p —(R 9 ) 2 , wherein R 9  is a C 1 -C 20  alkyl group, and m and p are each an integer of from 5 to 20, and the organic alkyl aluminum is (R 3 ) r Al(E) 3-r , wherein R 13  is a C 1 -C 8  alkyl group, E is a hydrogen atom or a halogen atom, and r is an integer ranging from 1 to 3.  
   
   
       12 . The arylphenoxy catalyst system as set forth in  claim 11 , wherein the organic alkyl aluminum is triethylaluminum or triisobutylaluminum.  
   
   
       13 . A method of producing an ethylene homopolymer or a copolymer of ethylene and an α-olefin comprising the step of reacting ethylene alone or in admixture with an α-olefin in the presence of the arylphenoxy-based transition metal catalyst of  claim 1  at 10-150 atm and a reaction temperature of 120-250° C.  
   
   
       14 . A method of producing a copolymer of ethylene and α-olefin wherein the copolymer has an ethylene content of 60 wt % or more comprising the step of reacting ethylene and a comonomer in the presence of the arylphenoxy catalyst of  claim 7 , wherein the comonomer is 1-butene, 1-hexene, 1-octene, or 1-decene.  
   
   
       15 . The arylphenoxy catalyst system as set forth in  claim 11 , wherein R 9  is a metyl or isobutyl group.