Phosphorus-sulfur FR additives and polymer systems containing same

Abstract

Phosphorus-sulfur compounds have flame retardant activity in organic polymer systems. The phosphorus-sulfur compounds can be represented by the structure: wherein X is oxygen or sulfur, T is a covalent bond, oxygen, sulfur or nitrogen, provided that at least one of X and T is sulfur, each X′ is independently oxygen or sulfur, each m is independently zero or 1 when X′ is oxygen and zero, 1 or 2 when X′ is sulfur, n is at least 1 and preferably at least 2, each R is independently an unsubstituted or inertly substituted hydrocarbyl group or the R groups together form an unsubstituted or inertly substituted divalent organic group and A is an organic linking group.

1 . A polymer composition comprising a combustible polymer and an effective amount of a phosphorus-sulfur additive represented by the structure I: 
       
         
           
           
               
               
           
         
       
       wherein X is oxygen or sulfur, T is a covalent bond, oxygen, sulfur or —NR 4 —, wherein R 4  is hydrogen, alkyl, inertly substituted alkyl or a P(X)[(X)′ m R] 2  group, provided that at least one of X and T is sulfur, each X′ is independently oxygen or sulfur, each m is independently zero or 1 when X′ is oxygen and zero, 1 or 2 when X′ is sulfur, n is at least 1, each R is independently an unsubstituted or inertly substituted hydrocarbyl group or the R groups together form an unsubstituted or inertly substituted divalent organic group, and A is an organic linking group. 
     
     
         2 . The polymer composition of  claim 1  wherein n is at least 2. 
     
     
         3 . The polymer composition of  claim 6  wherein the phosphorus-sulfur additive contains from 5 to 30% by weight of sulfur. 
     
     
         4 . The polymer composition of  claim 2 , wherein said phosphorus-sulfur additive is represented by the structure: 
       
         
           
           
               
               
           
         
       
       wherein X is oxygen or sulfur, T is a covalent bond, oxygen, sulfur or —NR 4 —, wherein R 4  is hydrogen, alkyl or inertly substituted alkyl, provided that at least one of X and T is sulfur, each X′ is independently oxygen or sulfur, n is at least 2, each R 2  is independently hydrogen, alkyl or inertly substituted alkyl, R 3  is a covalent bond or a divalent linking group and A is an organic linking group. 
     
     
         5 . The polymer composition of  claim 4  wherein T is sulfur, X is sulfur, each X′ is oxygen, each R 2  is independently hydrogen or an alkyl group, and R 3  is a (dialkyl)methylene group. 
     
     
         6 . The polymer composition of  claim 4  wherein said phosphorus-sulfur additive is represented by the structure: 
       
         
           
           
               
               
           
         
       
       wherein X is oxygen or sulfur, A is an organic linking group, and n is at least 2. 
     
     
         7 . The polymer composition of  claim 2  wherein A is an organic polymer. 
     
     
         8 . The composition of  claim 3  wherein A is a polymer of styrene, a polymer of butadiene or a copolymer of styrene and butadiene. 
     
     
         9 . The polymer composition of  claim 1  wherein the combustible polymer is a polyolefin, a polycarbonate, a blend of polycarbonate with a polyester, a blend of a polycarbonate with an acrylonitrile-styrene-butadiene polymer, a blend of a polycarbonate and a styrene-acrylonitrile polymer, a blend of a polycarbonate and polystyrene, a polyamide, a polyester, an epoxy resin, a polyurethane, a vinyl aromatic polymer, a rubber-modified vinyl aromatic polymer, a styrene-acrylonitrile polymer, a styrene-butadiene copolymer or a mixture of two or more thereof. 
     
     
         10 . The polymer composition of  claim 9  wherein the combustible polymer is a foam. 
     
     
         11 . A phosphorus-sulfur compound represented by the structure 
       
         
           
           
               
               
           
         
       
       wherein X is oxygen or sulfur, T is a covalent bond, oxygen, sulfur or —NR 4 —, wherein R 4  is hydrogen, alkyl or inertly substituted alkyl, provided that at least one of X and T is sulfur, X′ is oxygen or sulfur, n is at least 1, each R is independently an unsubstituted or inertly substituted hydrocarbyl group or the R groups together form an unsubstituted or inertly substituted divalent organic group and A is an organic linking group. 
     
     
         12 . The phosphorus-sulfur compound of  claim 11  wherein X′ is oxygen. 
     
     
         13 . The phosphorus-sulfur compound of  claim 11  wherein T is sulfur, n is at least 2, and the R groups together form an unsubstituted or inertly substituted divalent organic group. 
     
     
         14 . The phosphorus-sulfur compound of  claim 11  wherein the A group is bonded to the T atom through an allylic or benzylic carbon atom. 
     
     
         15 . The phosphorus-sulfur compound of  claim 14  wherein the A group is an organic polymer. 
     
     
         16 . A phosphorus-sulfur compound represented by the structure: 
       
         
           
           
               
               
           
         
       
       wherein X is oxygen or sulfur, T is oxygen, sulfur or —NR 4 —, wherein R 4  is hydrogen, alkyl or inertly substituted alkyl, provided that at least one of X and T is sulfur, each X′ is independently oxygen or sulfur, n is at least 1, each R 2  is independently hydrogen, alkyl or inertly substituted alkyl, R 3  is a covalent bond or a divalent linking group and A is an organic linking group. 
     
     
         17 . The phosphorus-sulfur compound of  claim 16  wherein each X′ is oxygen, T is sulfur, X is sulfur, each R 2  is hydrogen, and R 3  is an alkylene diradical having no hydrogens on the carbon atom(s) bonded directly to the adjacent (R 2 ) 2 C groups. 
     
     
         18 . The phosphorus-sulfur compound of  claim 17  wherein the A group is an organic polymer. 
     
     
         19 . A phosphorus-sulfur compound represented by the structure: 
       
         
           
           
               
               
           
         
       
       wherein X is oxygen or sulfur, T is a covalent bond, oxygen, sulfur or —NR 4 —, wherein R 4  is hydrogen, alkyl or inertly substituted alkyl, provided that at least one of X and T is sulfur, X′ is oxygen or sulfur, n is at least 1 and A is an organic linking group. 
     
     
         20 . The phosphorus-sulfur compound of  claim 19  wherein the A group is an organic polymer. 
     
     
         23 . A phosphorus-sulfur compound represented by either of the structures 
       
         
           
           
               
               
           
         
       
       wherein X is oxygen or sulfur, T is a covalent bond, oxygen, sulfur or —NR 4 —, wherein R 4  is hydrogen, alkyl or inertly substituted alkyl provided that at least one of X and T is sulfur, n is at least 1, each R is independently an unsubstituted or inertly substituted hydrocarbyl group or the R groups together form an unsubstituted or inertly substituted divalent organic group and A is
 (1) an organic polymer; 
 (2) an organic group bonded to the -T- linkage through a benzylic carbon; 
 (3) an organic group bonded to the -T- linkage through an acrylic or methacrylic group; 
 (4) a residue of a ester of a diol or diacid having non-aromatic carbon-carbon unsaturation after addition of a phosphorus-sulfur group to the carbon-carbon double bond of the ester; 
 (5) a residue of a fatty acid or ester thereof (including a fatty acid triglyceride), wherein the fatty acid has at least one carbon-carbon unsaturation site, after addition of a phosphorus-sulfur group to such carbon-carbon unsaturation site, or 
 (6) an aromatic group bonded to the -T- linkage through an aromatic carbon atom. 
 
     
     
         25 . The phosphorus-sulfur compound of claim  24  wherein the A group is an organic polymer.