Non-toxic organotin stabilizers for vinyl chloride polymers

Abstract

Vinyl chloride polymers suitable for use in food packaging materials are stabilized against discoloration and embrittlement resulting from exposure to heat using mono-n-octyltin compounds of the general formula H 17 C 8 Sn(SCH 2 COOR') 3 , wherein R' represents an alkyl radical containing eight carbon atoms.

What is claimed is: .[.1. A food grade liquid organotin stabilizer for polyvinyl chloride and copolymers of vinyl chloride with copolymerizable ethylenically unsaturated compounds, wherein said stabilizer consists essentially of between 95 and 100% by weight of mono-n-octyltin compound of the general formula ##STR4## wherein R' represents an alkyl radical containing eight carbon atoms, the remaining 0-5% of said stabilizer consisting essentially of other octyltin 
     
        compounds..]. .[.2.  The food grade liquid organotin stabilizer of claim 1 wherein the mono-n-octyltin compound is mono-n-octyltin-S,S',S"-tris(isooctyl mercaptoacetate)..]. .[.3. The food grade liquid organotin stabilizer of claim 2 which contains between 0 and 5%, based on the weight of the stabilizer of tri-n-octyltin-S-isooctyl mercaptoacetate..]. .[.4. The food grade liquid organotin stabilizer of claim 1 wherein said mono-n-octyltin compound is 
     
     
        mono-n-octyltin-S,S',S"-tris(2-ethylhexyl mercaptoacetate)..]. .Iadd.5.  A packaged foodstuff, comprising a food or beverage sealedly packaged within a shaped article packaging material which comprises a stabilized food grade vinyl halide polymer composition, said polymer composition comprising a nonhazardous effective stabilizing amount of a monoalkyltin compound having the formula n-C 8  H 17  Sn(SCH 2  COOR) 3  wherein R is a linear or branched alkyl group of 8 carbon atoms and said compound being individually devoid of such contaminants and exhibiting such acute, chronic and no-effect toxicity levels and extractability values as to satisfy FDA Toxicity Quotient criteria..Iaddend. .Iadd.6. The packaged foodstuff of claim 5, said vinyl halide polymer comprising a homopolymer or copolymer of vinyl chloride. .Iaddend. .Iadd.7. The packaged foodstuff of claim 6, said monoalkyltin compound having an acute oral toxicity of greater than 1 gram per kilogram of body weight, a maximum extraction from polyvinyl chloride by foodstuffs of less than 1 part per million, and a no-effect toxicity level for dogs of 300 parts per million per kilogram of foodstuff..Iaddend. .Iadd.8. The packaged foodstuff of claim 7, said polymer composition further comprising an 
     
     
        auxiliary food grade stabilizer..Iaddend. .Iadd.9.  The packaged foodstuff of claim 8, said polymer composition comprising a nonhazardous effective stabilizing amount of said monoalkyltin compound in admixture with di-n-octyltin-S,S'-bis(isooctylmercaptoacetate) auxiliary stabilizer..Iaddend. .Iadd.10. The packaged foodstuff of claim 9, said admixture containing up to about 75% by weight of said auxiliary stabilizer..Iaddend. .Iadd.11. The packaged foodstuff of claim 7, said polymer composition further comprising at least one antioxidant, plasticizer, impact modifying polymer, lubricant, ultra-violet absorber, dye, or mixture thereof..Iaddend. .Iadd.12. The packaged foodstuff of claim 7 wherein said monoalkyltin compound is mono-n-octyltin-S,S',S"-tris(isooctylmercaptoacetate)..Iaddend. .Iadd.13. The packaged foodstuff of claim 7 wherein said monoalkyltin compound is mono-n-octyltin-S,S',S"-tris(2-ethylhexylmercaptoacetate)..Iaddend. .Iadd.14. The packaged foodstuff of claim 7, said shaped article packaging 
     
     
        material comprising a film..Iaddend. .Iadd.15.  The packaged foodstuff of claim 7, said shaped article packaging material comprising a bottle..Iaddend. .Iadd.16. The packaged foodstuff of claim 7, said shaped article packaging material comprising a tray..Iaddend. .Iadd.17. The packaged foodstuff of claim 7, said monoalkyltin compound having a purity of at least 95% by weight..Iaddend. .Iadd.18. The packaged foodstuff of claim 7, said effective stabilizing amount ranging from 0.1 to 5% by weight..Iaddend. .Iadd.19. The packaged foodstuff of claim 18, said effective stabilizing amount ranging from 1 to 2% by weight..Iaddend. .Iadd.20. The packaged foodstuff of claim 9 wherein said monoalkyltin compound is mono-n-octyltin-S,S',S"-tris(isooctylmercaptoacetate). .Iaddend. .Iadd.21. The packaged foodstuff of claim 9 wherein said monoalkyltin compound is mono-n-octyltin-S,S',S"-tris(2-ethylhexylmercaptoacetate)..Iaddend.