Process for producing styrenic polymer

Abstract

There is disclosed a process for producing a styrenic polymer, especially, syndiotactic polystyrene, which comprises polymerizing a styrenic monomer by the use of (a) a transition metal compound, (b) a coordination complex compound comprising an anion in which a plurality of radicals are bonded to a metal and a cation or methylaluminoxane, (c) an alkylating agent (alkyl group-containing aluminum, magnesium or zinc compound) and (d) a reaction product between a straight-chain alkylaluminum having at least two carbon atoms and water (alkylaluminoxane). The above process is capable of simplifying the production process and producing high-performance styrenic polymer having a high degree of syndiotactic configuration in high catalytic activity without deteriorating the catalyst activity, increasing the amounts of residual metals in the objective polymer or leaving the decomposition products of the alkylaluminum therein, thereby curtailing the production cost of the objective polymer.

What is claimed is:  
     
       1. A process for producing a styrenic polymer having a high degree of syndiotacticity, which comprises: 
       polymerizing a styrenic monomer in the presence of a catalyst of (a) a transition metal compound, (b) methylaluminoxane, (c) at least one alkylating agent selected from the group consisting of triethylaluminum, tri-n-propylaluminum, triisopropylaluminum, tri-n-butylaluminum, triisobutylaluminum, tri-tert-butylaluminum, dialkylaluminumhalide, dialkylmagnesium and dialkylzinc, and (d) a reaction product between a straight-chain alkylaluminum having at least 2 carbon atoms in the alkyl group as represented by formula (XVIII) and water:  
       
         
           R o   3 Al  (XVIII)  
         
       
       wherein R o  is a straight-chain alkyl group having 2 to 10 carbon atoms.  
     
     
       2. The process according to claim  1  wherein the reaction product as the component (d) is a compound represented by formula                    
       wherein R o  is a straight-chain alkyl group having 2 to 10 carbon atoms and n is an integer of 1 to 20. 
     
     
       3. The process according to claim  1  wherein the reaction product as the component (d) is at least one member selected from the group consisting of ethylaluminoxane, propylaluminoxane, butylaluminoxane, pentylaluminoxane, hexylaluminoxane and heptylaluminoxane. 
     
     
       4. The process according to claim  1 , wherein (a) said transition metal compound is of formula (I), (II), (VI) or (VII): 
       
         
           MR 1   a R 2   b R 3   c R 4   4-(a+b+c)   (I)  
         
       
       
         
           MR 1   d R 2   e R 3   3-(d+e)   (II)  
         
       
       wherein M is a metal belonging to any of the groups 3 to 6 of the Periodic Table or a lanthanum series metal; R 1 , R 2 , R 3  and R 4  are each an alkyl group, an alkoxy group, an aryl group, a cyclopentadienyl group, an alkylthio group, a substituted cyclopentadienyl group, an indenyl group, a substituted indenyl group, a fluorenyl group, a halogen atom or a chelating agent; a, b and c are each an integer of from 0 to 4; d and e are each an integer of from 0 to 3; and any two of R 1  to R 4  may form a complex which is crosslinked with CH 2  or Si(CH 3 ) 2 ;                    
       wherein R 9  and R 10  each represent a halogen atom, an alkoxyl group having 1 to 20 carbon atoms or an acyloxyl group; and k is an integer of from 2 to 20; 
       
         
           M 1 R 11 R 12 R 13 R 14   (VII)  
         
       
       wherein m 1  is titanium, zirconium or hafnium; R 11  and R 12  are each a cyclopentadienyl group, a substituted cyclopentadienyl group, an indenyl group or a fluorenyl group and R 13  and R 14  are each a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, an alkoxyl group having 1 to 20 carbon atoms, an amino group or thioalkoxyl group having 1 to 20 carbon atoms, but R 11  and R 12  may be each crosslinked by a hydrocarbon group having 1 to 5 carbon atoms, an alkylsilyl group having 1 to 20 carbon atoms and 1 to 5 silicon atoms or a germanium-containing hydrocarbon group having 1 to 20 carbon atoms and 1 to 5 germanium atoms.  
     
     
       5. The process according to claim  4 , wherein M or M 1  is titanium. 
     
     
       6. The process according to claim  4 , wherein R 1  is a cyclopentadienyl group, a substituted cyclopentadienyl group, an indenyl group or a substituted indenyl group. 
     
     
       7. The process according to claim  5 , wherein R 1  is a cyclopentadienyl group, a substituted cyclopentadienyl group, an indenyl group or a substituted indenyl group.