Nitrosophenols and C-nitrosoanilines as polymerization inhibitors
View Patent ↗Inhibitor blends that include both nitrosophenols and nitrosoanilines, optionally in combination with air or oxygen, reduce the premature polymerization of ethylenically unsaturated monomers. unsaturated monomers.
1. A process for inhibiting the premature polymerization of an ethylenically unsaturated monomer during production, distillation, purification or storage of the monomer, which comprises: incorporating in the monomer, in an effective inhibiting amount sufficient to prevent premature polymerization during production, distillation, purification or storage of said monomer, a blend comprising at least one C-nitrosoaniline compound and at least one nitrosophenol selected from the group consisting of 4-nitrosophenol, 2-nitrosophenol, 4-nitroso-o-cresol, 2-nitroso-p-cresol, 2-tert-butyl-4-nitrosophenol, 4-tert-butyl-2-nitrosophenol, 2,6-di-tert-butyl-4-nitrosophenol, 2-tert-amyl-4-nitrosophenol, 4-tert-amyl-2-nitrosophenol, 2,6-di-tert-amyl-4-nitrosophenol, 2-nitroso-1-naphthol, 4-nitroso-1-naphthol, 2-tert-butyl-4-nitroso-1-naphthol, 1-nitroso-2-naphthol, 6-nitroso-2-naphthol and 2-tert-amyl-nitroso-1-naphthol.
2. A process according to claim 1 wherein the blend further comprises oxygen or air.
3. A process according to claim 1 wherein the inhibition of premature polymerization of the ethylenically unsaturated monomer occurs during distillation or purification.
4. A process according to claim 1 wherein the distillation or purification is conducted at a temperature from 50° C. to 150° C.
5. A process according to claim 1 wherein the at least one nitrosophenol is selected from the group consisting of 4-nitrosophenol, 4-nitroso-o-cresol, 2-tert-butyl-4-nitrosophenol, 2,6-di-tert-butyl-4-nitrosophenol, 2-tert-amyl-4-nitrosophenol, 2-nitroso-1-naphthol, 4-nitroso-1-naphthol, 2-tert-butyl-4-nitroso-1-naphthol and 1-nitroso-2-naphthol.
6. A process for inhibiting the premature polymerization of an ethylenically unsaturated monomer during production, distillation, purification or storage of the monomer, which comprises: incorporating in the monomer, in an effective inhibiting amount sufficient to prevent premature polymerization during production, distillation, purification or storage of said monomer, a blend comprising at least one nitrosophenol compound and at least one C-nitrosoaniline compound selected from the group consisting of: 4-nitroso-N-(1,4-dimethylpentyl)aniline, 4-nitroso-N-phenylaniline, 4-nitroso-N-isopropylaniline, 4-nitroso-N,N-dimethylaniline, 4-nitroso-N,N-diethylaniline, 4-nitroso-N,N-diphenylaniline, 4-nitroso-N,N-diisopropylaniline, 4-nitrosoaniline, 2-nitroso-N-(1,4-dimethylpentyl)aniline, 2-nitroso-N-phenylaniline, 2-nitroso-N,N-dimethylaniline, 2-nitroso-N,N-diethylaniline, 2-nitroso-N,N-diphenylaniline, 2-nitrosoaniline, 2-t-butyl-4-nitroso-N-(1,4-dimethylpentyl)aniline, 2-methyl-4-nitroso-N-(1,4-dimethylpentyl)aniline, 2-t-butyl-4-nitroso-N-phenylaniline, 2-methyl-4-nitroso-N-phenylaniline, 4-t-butyl-2-nitroso-N-(1-,4-dimethylpentyl)aniline, 4-t-butyl-2-nitroso-N-phenylaniline, 4t-butyl-2-nitroso-N,N-dimethylaniline, 4-t-butyl-2-nitroso-N,N-diethylaniline, 4t-butyl-1-2-nitroso-N,N-diphenylaniline, 4-nitroso-N-(1,3-dimethyl-butyl)aniline, 2-nitroso-N-(1,3-dimethylbutyl)aniline and 4-t-butyl-2-nitrosoaniline.
7. A process according to claim 6 wherein the at least one C-nitrosoaniline is selected from the group consisting of 4-nitroso-N-(1,4-dimethylpentyl)aniline, 4-nitroso-N-p-henylaniline, 4-nitroso-N-isopropylaniline, 4-nitroso-N,N-dimethylaniline, 4-nitroso-N,N-diethylaniline, 4-nitroso-N,N-diphenylaniline, 4-nitroso-N,N-diisopropylaniline, 4-nitrosoaniline, 2-t-butyl-4-nitroso-N-(1,4-dimethylpentyl)aniline, 2-methyl-4-nitroso-N-(1,4-dimethylpentyl)aniline, 2-t-butyl-4-nitroso-N-phenylaniline and 2-methyl-4-nitroso-N-phenylaniline.
8. A process according to claim 6 wherein the blend further comprises oxygen or air.
9. A process according to claim 6 wherein the inhibition of premature polymerization of the ethylenically unsaturated monomer occurs during distillation or purification.
10. A process according to claim 9 wherein the distillation or purification is conducted at a temperature from 50° C. to 150° C.
11. A method for distilling a feed comprising at least one polymerizable ethylenically unsaturated monomer, said method comprising the steps of: introducing a feed comprising at least one polymerizable ethylenically unsaturated monomer into a distillation apparatus; introducing an effective inhibiting amount, sufficient to prevent premature polymerization of said ethylenically unsaturated monomer, of a blend comprising at least one nitrosophenol compound and at least one C-nitrosoaniline compound selected from the group consisting of: 4-nitroso-N-(1-,4-dimethylpentyl)aniline, 4-nitroso-N-phenylaniline 4-nitroso-N-isopropylaniline, 4-nitroso-N,N-dimethylaniline, 4-nitroso-N,N-diethylaniline, 4-nitroso-N,N-diphenylaniline, 4-nitroso-N,N-diisopropylaniline, 4-nitrosoaniline, 2-nitroso-N-(1-,4-dimethylpentyl)aniline, 2-nitroso-N-phenylaniline, 2-nitroso-N,N-dimethylaniline, 2-nitroso-N,N-diethylaniline, 2-nitroso-N,N-diphenylaniline, 2-nitrosoaniline, 2-t-butyl-4-nitroso-N-(1-4-dimethylpentyl)aniline, 2-methyl-4-nitroso-N-(1-,4-dimethylpentyl)aniline, 2-t-butyl-4-nitroso-N-phenylaniline, 2-methyl-4-nitroso-N-phenylaniline, 4-t-butyl-2-nitroso-N-(1-4-dimethylpentyl)aniline, 4-t-butyl-2-nitroso-N-phenylaniline, 4-t-butyl=2-nitroso-N,N-dimethylaniline, 4-t-butyl-2-nitroso-N,N-diethylaniline, 4-t-butyl-2-nitroso-N,N-diphenylaniline, 4-nitroso-N-(1,3-dimethyl- butyl)aniline, 2-nitroso-N- (1,3-dimethylbutyl)aniline and 4-t-butyl-2-nitrosoaniline, into said distillation apparatus; and distilling said feed under distillation conditions in the presence of said inhibitor blend to recover from said distillation apparatus an overhead product of high purity ethylenically unsaturated monomer and a residual bottoms fraction having a reduced content of polymeric material.
12. A method for distilling a feed comprising at least one polymerizable ethylenically unsaturated monomer, said method comprising the steps of: introducing a feed comprising at least one polymerizable ethylenically unsaturated monomer into a distillation apparatus; introducing an effective inhibiting amount, sufficient to prevent premature polymerization of said ethylenically unsaturated monomer, of a blend comprising at least one C-nitrosoaniline compound and at least one nitrosophenol selected from the group consisting of 4-nitroso-N-(1,4-dimethylpentyl)aniline, 4-nitroso-N-phenylaniline, 4-nitroso-N-isopropylaniline, 4-nitroso-N,N-dimethylaniline, 4-nitroso-N,N-diethylaniline, 4-nitroso-N,N-diphenylaniline, 4-nitroso-N,N-diisopropylaniline, 4-nitrosoaniline, 2-nitroso-N-(1,4-dimethylpentyl)aniline, 2-nitroso-N-phenylaniline, 2-nitroso-N,N-dimethylaniline, 2-nitroso-N,N-diethylaniline, 2-nitroso-N,N-diphenylaniline, 2-nitrosoaniline, 2-t-butyl-4-nitroso-N-(1,4-dimethylpentyl)aniline, 2-methyl-4-nitroso-N-(1,4-dimethylpentyl)aniline, 2-t-butyl-4-nitroso-N-phenylaniline, 2-methyl-4-nitroso-N-phenylaniline, 4-t-butyl-2-nitroso-N-(1-,4-dimethylpentyl)aniline, 4-t-butyl-2-nitroso-N-phenylaniline, 4-t-butyl-2-nitroso-N,N-dimethylaniline, 4-t-butyl-2-nitroso-N,N-diethylaniline, 4-t-butyl-2-nitroso-N,N-diphenylaniline, 4-nitroso-N-(l ,3-dimethyl- butyl)aniline, 2-nitroso-N-(1,3-dimethylbutyl)aniline and 4-t-butyl-2-nitrosoaniline, into said distillation apparatus; and distilling said feed under distillation conditions in the presence of said inhibitor blend to recover from said distillation apparatus an overhead product of high purity ethylenically unsaturated monomer and a residual bottoms fraction having a reduced content of polymeric material.