Phosphorus-sulfur FR additives and polymer systems containing same
View Patent ↗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 either of the structures:
wherein X is oxygen or sulfur, T is 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.
2. The polymer composition of claim 1 wherein the phosphorus-sulfur additive contains from 5 to 30% by weight of sulfur.
3. The polymer composition of claim 1 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.
4. The polymer composition of claim 1 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.
5. The polymer composition of claim 1 wherein A is an organic polymer.
6. The composition of claim 2 wherein A is a polymer of styrene, a polymer of butadiene or a copolymer of styrene and butadiene.
7. 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.
8. The polymer composition of claim 7 wherein the combustible polymer is a foam.
9. A phosphorus-sulfur compound represented by the structure:
wherein X is oxygen or sulfur, T 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.
10. The phosphorus-sulfur compound of claim 9 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.
11. The phosphorus-sulfur compound of claim 10 wherein the A group is an organic polymer.
12. A phosphorus-sulfur compound represented by the structure:
wherein X is oxygen or sulfur, T is 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 2 and A is an organic linking group.
13. The phosphorus-sulfur compound of claim 12 wherein the A group is an organic polymer.