Dispersant having multifunctional head and phosphor paste composition comprising the same

Abstract

Disclosed is a dispersant having a multifunctional head, and a phosphor paste composition comprising the dispersant. The dispersant has a multifunctional head that comprises an acidic group, a basic group and an aromatic group, thereby enhancing an affinity for the surface of phosphor particles and improving dispersibility.

1 . A dispersant having a multifunctional head represented by Formula 1 or 2: 
       
         
           
           
               
               
           
         
         wherein A is an aromatic group, B is an acidic group and C is a basic group; 
         a, b and c are independently an integer from 0 to about 10 with the proviso that two or more of a, b and c are not simultaneously zero; 
         n is an integer of about 1 to about 15; and 
         D is hydrogen, alkyl, polyester or polyether; 
       
       
         
           
           
               
               
           
         
         wherein A is an aromatic group, B is an acidic group and C is a basic group; 
         a, b and c are independently an integer from 0 to about 10 with the proviso that two or more of a, b and c are not simultaneously zero; 
         n is an integer of about 1 to about 15; and 
         D is hydrogen, alkyl, polyester or polyether. 
       
     
     
         2 . The dispersant according to  claim 1 , wherein in Formula 1 and 2, A is selected from the group consisting of benzene and a heterocyclic compound substituted with nitrogen (N), sulfur (S) or oxygen (O),
 B is selected from the group consisting of carboxyl (COOH) and phosphoryl (POOH) groups, and   C is selected from the group consisting of aliphatic amine (—NR 2 ) wherein R is H, CH 3 , CH 2 CH 3 , (CH 2 ) 2 CH 3 , or (CH 2 ) 3 CH 3  and aromatic amine (—XNR 2 ) wherein X is benzene and R is H, CH 3 , CH 2 CH 3 , (CH 2 ) 2 CH 3 , or (CH 2 ) 3 CH 3 .   
     
     
         3 . The dispersant according to  claim 1 , wherein the dispersant of Formula 1 is represented by Formula 3 below: 
       
         
           
           
               
               
           
         
         wherein a, b and c are independently an integer from 0 to about 10 with the proviso that two or more of a, b and c are not simultaneously zero, and 
         n is an integer of about 1 to about 15. 
       
     
     
         4 . The dispersant according to  claim 1 , wherein the dispersant of Formula 2 is represented by Formula 4 below: 
       
         
           
           
               
               
           
         
         wherein a, b and c are independently an integer from 0 to about 10 with the proviso that two or more of a, b and c are not simultaneously zero, and 
         n is an integer of about 1 to about 15. 
       
     
     
         5 . The dispersant according to  claim 1 , wherein the dispersant has a molecular weight of 1,000 to 20,000 grams per mole. 
     
     
         6 . A fluorescent film for a display device produced from a phosphor paste composition, the phosphor paste composition comprising:
 a dispersant represented by Formula 1 or 2 below;   a binder solution of an organic binder in a solvent; and   a phosphor   
       
         
           
           
               
               
           
         
       
       wherein A is an aromatic group, B is an acidic group and C is a basic group,
 a, b and c are independently an integer from 0 to about 10 with the proviso that two or more of a, b and c are not simultaneously zero, 
 n is an integer of about 1 to about 15, and 
 D is hydrogen, alkyl, polyester or polyether; 
 
       
         
           
           
               
               
           
         
         wherein A is an aromatic group, B is an acidic group and C is a basic group, a, b and c are independently an integer from 0 to about 10 with the proviso that two or more of a, b and c are not simultaneously zero, and n is an integer of about 1 to about 15. 
       
     
     
         7 . A display device comprising the fluorescent film according to  claim 6 . 
     
     
         8 . The display device according to  claim 7 , wherein the display device is a cathodoluminescent display, a liquid crystal display, an electroluminescence display, a field emission display, or a vacuum fluorescent display. 
     
     
         9 . An article comprising the fluorescent film according to  claim 6 . 
     
     
         10 . The article according to  claim 9 , wherein the article is an exterior decoration or keypad of cellular phone.