Ortho-nitrosophenols as polymerization inhibitors

Abstract

Disclosed herein is a method for inhibiting the premature polymerization of ethylenically unsaturated monomers comprising adding to said monomers an effective amount of at least one nitroso inhibitor of the structure: wherein R 1 , R 2 , R 3 , and R 4 are independently selected from the group consisting of hydrogen, nitro, nitroso, halogen, COOR wherein R is hydrogen or alkyl, alkyl, and heteroatom-substituted alkyl; or adjacent groups R 1 , R 2 , R 3 , and R 4 can be taken together to form a substituted or unsubstituted fused six-membered ring. Also disclosed is a composition of matter comprising: A) an ethylenically unsaturated monomer and B) at least one nitroso compound of the above-described structure.

1 - 11 . (canceled) 
     
     
         12 . A composition of matter comprising:
 A) an ethylenically unsaturated monomer and   B) an effective inhibiting amount, sufficient to prevent premature polymerization during distillation or purification of said ethylenically unsaturated monomer, of at least one nitroso compound of the structure:   
       
         
           
           
               
               
           
         
       
       wherein R 1 , R 2 , R 3 , and R 4  are independently selected from the group consisting of hydrogen, nitro, nitroso, halogen, COOR wherein R is hydrogen or alkyl, alkyl, and heteroatom-substituted alkyl; or adjacent groups R 1 , R 2 , R 3 , and R 4  can be taken together to form a substituted or unsubstituted fused six-membered ring. 
     
     
         13 . The composition of  claim 12  further comprising at least one additional compound selected from the group consisting of quinone alkides, nitroxyl compounds, nitroaromatic compounds, hydroxylamine compounds, phenylenediamine compounds, quinone compounds, and hydroquinone compounds. 
     
     
         14 . The composition of  claim 12  further comprising oxygen. 
     
     
         15 . The composition of  claim 13  further comprising oxygen. 
     
     
         16 . The composition of  claim 12  wherein the nitroso inhibitor is 2-nitroso-naphthol. 
     
     
         17 . The composition of  claim 13  wherein the nitroso inhibitor is 2-nitroso-naphthol. 
     
     
         18 . The composition of  claim 12  wherein the nitroso inhibitor is 1-nitroso-2-naphthol. 
     
     
         19 . The composition of  claim 13  wherein the nitroso inhibitor is 1-nitroso-2-naphthol.