Polyester-polycarbonate copolymer and method for producing same

Abstract

Polycarbonate block copolymers are provided, which have: (A) a polyester block of chemical formula 1; and (B) a polycarbonate block derived from a dihydric phenol of chemical formula 3 compound and phosgene. The copolymers may be prepared by (1) polymerizing ester oligomers to form a compound of chemical formula 1; and (2) copolymerizing the ester oligomer obtained in (1) with a polycarbonate oligomer prepared from a dihydric phenol compound of chemical formula 3 and phosgene, in the presence of a polymerization catalyst. The block copolymer may have a viscosity average molecular weight (Mv) of 10,000 to 200,000. The thermoplastic copolymer resins have excellent heat resistance, transparency, impact strength, and fluidity, and thus can be usefully applied in various products, including office devices, electric/electronic products, and automotive interior/exterior parts;

1 . A polycarbonate block copolymer comprising, as repeating units, (A) a polyester block having a structure represented by the following chemical formula 1; and (B) a polycarbonate block: 
       
         
           
           
               
               
           
         
         wherein, in the above chemical formula 1, 
         R 1  independently represents hydrogen atom, alkyl, cycloalkyl, cycloalkylalkyl or aryl; 
         X independently represents oxygen or NRR, where R 2  independently represents hydrogen atom, alkyl, cycloalkyl, cycloalkylalkyl or aryl; 
         R 3  independently represents alkyl, cycloalkyl, cycloalkylalkyl or aryl; and 
         m is independently an integer of 2 to 50. 
       
     
     
         2 . The polycarbonate block copolymer of claim I , wherein the polyester block having a structure represented by chemical formula 1 is derived from an ester oligomer prepared by condensation reaction of a compound represented by the following chemical formula 2-1 and a compound represented by the following chemical formula 2-2: 
       
         
           
           
               
               
           
         
         wherein, in the above chemical formulas 2-1 and 2-2, 
         R 1  independently represents hydrogen atom, alkyl having 1 to 4 carbons, cycloalkyl having 3 to 6 carbons, cycloalkylalkyl having 4 to 10 carbons or aryl having 6 to 10 carbons; 
         X independently represents oxygen or NR 2 , where R 2  independently represents hydrogen atom, alkyl having 1 to 4 carbons, cycloalkyl having 3 to 6 carbons, cycloalkylalkyl having 4 to 10 carbons or aryl having 6 to 10 carbons; 
         Y independently represents hydroxyl or halogen atom; and 
         R 3  independently represents alkyl having 1 to 10 carbons, cycloalkyl having 3 to 6 carbons, cycloalkylalkyl having 4 to 10 carbons or aryl having 6 to 10 carbons. 
       
     
     
         3 . The polycarbonate block copolymer of  claim 2 , wherein the reaction molar ratio of a compound of chemical formula 2-1 to a compound of chemical formula 2-2 is 1:0.5 to 1:2. 
     
     
         4 . The polycarbonate block copolymer of  claim 2 , wherein the ester oligomer has a number average molecular weight of 500 to 20,000 g/mol. 
     
     
         5 . The polycarbonate block copolymer of  claim 1 , wherein the polycarbonate block is derived from a polycarbonate oligomer prepared by a phosgene method using a dihydric phenol compound and phosgene. 
     
     
         6 . The polycarbonate block copolymer of  claim 5 , wherein the dihydric phenol compound is bisphenol A. 
     
     
         7 . The polycarbonate block copolymer of  claim 5 , wherein the polycarbonate oligomer has a viscosity average molecular weight of 1,000 to 20,000. 
     
     
         8 . The polycarbonate block copolymer of  claim 1 , wherein the amount of the polyester block (A) having a structure represented by chemical formula 1 is 0.5 to 50 mol %, based on the total moles of the monomer compounds constituting the copolymer as 100 mol %. 
     
     
         9 . The polycarbonate block copolymer of  claim 1 , which has a viscosity average molecular weight (Mv) of 10,000 to 200,000. 
     
     
         10 . A method for preparing a polycarbonate block copolymer, comprising the steps of:
 (1) polymerizing an ester oligomer by condensation reaction of a compound represented by the following chemical formula 2-1 and a compound represented by the following chemical formula 2-2; and   (2) copolymerizing the ester oligomer obtained in the above step (1) and polycarbonate in the presence of a polymerization catalyst:   
       
         
           
           
               
               
           
         
         wherein, in the above chemical formulas 2-1 and 2-2, 
         R 1  independently represents hydrogen atom, alkyl having 1 to 4 carbons, cycloalkyl having 3 to 6 carbons, cycloalkylalkyl having 4 to 10 carbons or aryl having 6 to 10 carbons; 
         X independently represents oxygen or NR 2 , where R 2  independently represents hydrogen atom, alkyl having 1 to 4 carbons, cycloalkyl having 3 to 6 carbons, cycloalkylalkyl having 4 to 10 carbons or aryl having 6 to 10 carbons; 
         Y independently represents hydroxyl or halogen atom; and 
         R 3  independently represents alkyl having 1 to 10 carbons, cycloalkyl having 3 to 6 carbons, cycloalkylalkyl having 4 to 10 carbons or aryl having 6 to 10 carbons. 
       
     
     
         11 . A molded article comprising the polycarbonate block copolymer of  claim 1 . 
     
     
         12 . The molded article of  claim 11 , which is an optical material or an automotive part.