Phosphorous-containing flame retardants for polyurethane foams

Abstract

Embodiments of the invention include a phosphorus containing flame retardant which may be the reaction product of a reaction mixture where the reaction mixture includes at least one first polyol and at least one phosphorus containing compound having the general formula (1), (2) or combination thereof:

1 . A phosphorus containing flame retardant comprising the reaction product of a first reaction mixture, the reaction mixture comprising:
 at least one first polyol; and   at least one phosphorus containing compound having the general formula (1), (2) or combination thereof:   
       
         
           
           
               
               
           
         
       
       wherein X is a leaving group, R 1  and R 2  are, independently of one another, a C 1 -C 8 -alkyl, C 1 -C 4 -alkoxyethyl, C 1 -C 4 -alkyl-substituted C 6 -C 10 -aryl radical, alkyl substituted aryl, aryl substituted alkyl, nitro alkyl, hydroxyl alkyl, alkoxy alkyl, hydroxyl alkoxyalkyl, or R 1  and R 2  together form R in a six-membered ring, wherein the six membered ring has the general formula (3), (4) or combination thereof: 
       
         
           
           
               
               
           
         
       
       wherein R is a linear or branched divalent alkylene group containing from 3 to about 9 carbon atoms. 
     
     
         2 . A method of making a phosphorus containing flame retardant, the method comprising: 
       reacting at least:
 at least one first polyol; with 
 at least one phosphorus containing compound having the general formula (1), (2) or combination thereof: 
 
       
         
           
           
               
               
           
         
       
       wherein X is a leaving group, R 1  and R 2  are, independently of one another, a C 1 -C 8 -alkyl, C 1 -C 4 -alkoxyethyl, C 1 -C 4 -alkyl-substituted C 6 -C 10 -aryl radical, alkyl substituted aryl, aryl substituted alkyl, nitro alkyl, hydroxyl alkyl, alkoxy alkyl, hydroxyl alkoxyalkyl, or R 1  and R 2  together form R in a six-membered ring, wherein the six membered ring has the general formula (3), (4) or combination thereof: 
       
         
           
           
               
               
           
         
       
       wherein R is a linear or branched divalent alkylene group containing from 3 to about 9 carbon atoms. 
     
     
         3 . The phosphorus containing flame retardant of  claim 1 , wherein R is at least one of propylene, 2-methylpropylene, neopentylene, and 2-butyl-2-ethylpropylene. 
     
     
         4 . The phosphonate flame retardant of  claim 1 , wherein X is selected from the group consisting of Cl − , Br − , and I − , and sulfonate. 
     
     
         5 . The phosphorus containing flame retardant of  claim 1 , wherein the phosphorus containing compound is 2-Chloro-5,5-dimethyl-1,3,2-dioxaphosphinane. 
     
     
         6 . The phosphorus containing flame retardant of  claim 1 , wherein the at least one first polyol comprises at least one of polyoxalkylene polyol having an equivalent weight about 50-2500 and a combined nominal functionality of about 2-10. 
     
     
         7 . The phosphorus containing flame retardant of  claim 6 , wherein the at least one polyoxalkylene polyol is initiated with glycerol, sucrose, sorbitol, or a combination thereof, and the polyoxalkylene comprises at least one of polyoxyethylene and polyoxypropylene. 
     
     
         8 . The phosphorus containing flame retardant of  claim 1 , wherein the first polyol comprises a sorbitol initiated polyoxypropylene polyol with an equivalent weight of between about 100 and about 200. 
     
     
         9 . The phosphorus containing flame retardant of  claim 1 , wherein the first polyol comprises a polyoxyethylene polyoxypropylene polyol initiated with a blend of glycerol and sucrose and having an equivalent weight of between about 1,000 and about 2500 and a polyoxyethylene percentage of between about 15% and about 40%, based on the weight of the polyoxyethylene polyoxypropylene polyol. 
     
     
         10 . The phosphorus containing flame retardant of  claim 1 , wherein the phosphorus containing flame retardant has a capping index such that the least one first polyol has on average at least one phosphorus containing compound reacted with a polyol OH site. 
     
     
         11 . The phosphorus containing flame retardant of  claim 9 , wherein the phosphorus containing flame retardant has a capping index such that the least one first polyol has on average at least half of its polyol OH sites capped by the at least one phosphorus containing compound. 
     
     
         12 . The phosphorus containing flame retardant of  claim 9 , wherein the phosphorus containing flame retardant has a capping index such that the least one first polyol has on average substantially all of its polyol OH sites capped by the at least one phosphorus containing compound. 
     
     
         13 . A polyurethane product comprising the reaction product of a second reaction mixture, the second reaction mixture comprising:
 at least one isocyanate; and   a polyol blend, the polyol blend comprising:
 at least one phosphorus containing flame retardant according to any one of  claims 1  and  3 - 12 ; and 
 at least one second polyol. 
   
     
     
         14 . The polyurethane product of  claim 13  which passes Cal 117 testing. 
     
     
         15 . The polyurethane product of  claim 13 , wherein the phosphorus containing flame retardant comprises between about 0.1 wt % and 35 wt % of the polyol blend. 
     
     
         16 . The method of  claim 2 , wherein R is at least one of propylene, 2-methylpropylene, neopentylene, and 2-butyl-2-ethylpropylene. 
     
     
         17 . The method of  claim 16 , wherein X is selected from the group consisting of Cl − , Br − , and I − , and sulfonate. 
     
     
         18 . The method of  claim 2 , wherein the phosphorus containing compound is 2-Chloro-5,5-dimethyl-1,3,2-dioxaphosphinane. 
     
     
         19 . The method  claim 2 , wherein the at least one first polyol comprises at least one of polyoxalkylene polyol having an equivalent weight about 50-2500 and a combined nominal functionality of about 2-10. 
     
     
         20 . The method of  claim 19 , wherein the at least one polyoxalkylene polyol is initiated with glycerol, sucrose, sorbitol, or a combination thereof, and the polyoxalkylene comprises at least one of polyoxyethylene and polyoxypropylene.