Transparent article made of pvc graft copolymers

Abstract

The invention relates to a method for producing vinyl chloride graft copolymers by emulsion polymerization and to a method for producing mixtures of said graft copolymers. The invention also relates to transparent molded bodies produced using the claimed graft copolymers or mixtures thereof.

1 - 17 . (canceled) 
     
     
         18 . A method of preparing a vinyl chloride graft copolymer composition, the method comprising:
 forming a vinyl chloride graft copolymer by:
 preparing a graft base by polymerizing monomers, wherein the graft base has a first glass transition temperature; 
 grafting a copolymer phase having a second glass transition temperature onto the graft base by emulsion polymerization, to form a vinyl chloride graft copolymer latex including the vinyl chloride graft copolymer; and 
 separating the vinyl chloride graft copolymer as a solid from the vinyl graft copolymer latex, 
 wherein the first glass transition temperature is lower than the second glass transition temperature and the average particle size of the vinyl chloride graft copolymer is less than 200 nm. 
   
     
     
         19 . The method of  claim 18 , wherein the second glass transition temperature is from about 20° C. to about 120° C. and the first glass transition temperature is from about −80° C. to about 20° C. 
     
     
         20 . The method of  claim 18 , wherein the copolymer phase is grafted onto the graft base by emulsion polymerization using at least one emulsifier. 
     
     
         21 . The method of  claim 20 , wherein from about 60 wt. % to about 100 wt. % of the at least one emulsifier is pre-charged. 
     
     
         22 . The method of  claim 18 , wherein the graft base of monomers is polymerized at a temperature of from about 20° C. to about 90° C. 
     
     
         23 . The method of  claim 18 , wherein the copolymer phase is grafted onto the graft base at a temperature of from about 45° C. to about 90° C. 
     
     
         24 . The method of  claim 18 , wherein the vinyl chloride graft copolymer comprises from about 5 wt. % to about 70 wt. % of the graft base and from about 30 wt. % to about 95 wt. % of the copolymer phase. 
     
     
         25 . The method of  claim 18 , wherein the graft base comprises a first polymerized vinyl compound and a second polymerized vinyl compound. 
     
     
         26 . The method of  claim 18 , wherein the copolymer phase comprises from about 60 wt. % to about 100 wt. % vinyl chloride and from about 0 wt. % to about 40 wt. % polymerized vinyl compounds. 
     
     
         27 . The method of  claim 18 , wherein the graft base and the grafted copolymer phase are cross-linked. 
     
     
         28 . The method of  claim 18  and further comprising:
 forming a second vinyl chloride graft copolymer by:
 grafting the copolymer onto the graft base by emulsion polymerization to form a second vinyl chloride graft copolymer latex including the second vinyl chloride graft copolymer; and 
 separating the second vinyl chloride graft copolymer as a solid from the second vinyl graft copolymer latex; and 
 
 combining the vinyl chloride graft copolymer and the second vinyl chloride graft copolymer, wherein the weight ratio of the graft base to the grafted copolymer base of the vinyl chloride graft copolymer is different than that of the second vinyl chloride graft copolymer. 
 
     
     
         29 . The method of  claim 18 , wherein the vinyl chloride graft copolymer composition has at a transmittance of at least 65%. 
     
     
         30 . The method of  claim 18 , wherein the vinyl chloride graft copolymer composition has at a haze value of less than 60. 
     
     
         31 . A vinyl chloride graft copolymer composition comprising:
 a vinyl chloride graft copolymer comprising:
 a polymerized graft base having a first glass transition temperature; and 
 a copolymer phase grafted onto the graft base, the copolymer phase having a second glass transition temperature that is higher than the first glass transition temperature, 
   wherein the average particle size of the vinyl chloride graft copolymer is less than 200 nm.   
     
     
         32 . The vinyl chloride graft copolymer composition of  claim 31 , further comprising a second vinyl graft chloride wherein the vinyl chloride graft copolymer and the second copolymer are selected from the group consisting of:
 graft copolymer A including from about 41 wt. % to about 70 wt. % of the graft base and from about 30 wt. % to about 59 wt. % of the grafted copolymer phase;   graft copolymer B including from about 26 wt. % to about 40 wt. % of the graft base and from about 60 wt. % to about 74 wt. % of the grafted copolymer phase; and   graft copolymer C including from about 5 wt. % to about 25 wt. % of the graft base and from about 75 wt. % to about 95 wt. % of the grafted copolymer phase.   
     
     
         33 . The vinyl chloride graft copolymer composition of  claim 31 , further comprising a second vinyl graft chloride wherein the vinyl chloride graft copolymer and the second copolymer are selected from the group consisting of:
 from about 1.0 wt. % to about 99 wt. % graft copolymer A;   from about 1.0 wt. % to about 99 wt. % graft copolymer B; and   from about 1.0 wt. % to about 99 wt. % graft copolymer C;   wherein the graft base has a glass transition temperature from about −80° C. to about 20° C., the grafted copolymer phase has a glass transition temperature from about 20° C. to about 120° C. and the vinyl chloride graft copolymer composition contains at least 25 wt. % of the graft base, and the balance is the grafted copolymer phase.   
     
     
         34 . The vinyl chloride graft copolymer composition of  claim 31 , wherein the vinyl chloride graft copolymer composition has at a transmittance of at least 65%. 
     
     
         35 . The vinyl chloride graft copolymer composition of  claim 31 , wherein the vinyl chloride graft copolymer composition has at a haze value of less than 60. 
     
     
         36 . The vinyl chloride graft copolymer composition of  claim 31 , further comprising a second vinyl graft chloride wherein the vinyl chloride graft copolymer has a first weight ratio of grafted base to grafted copolymer phase and the second vinyl chloride graft copolymer has a second weight ratio of graft base to grafted copolymer phase.