Inhibition of thermal polymerization and the growth of popcorn polymer

摘要

The growth of undesirable polymer in monomer/latex systems comprising at least one ethylenically unsaturated hydrocarbon or ester monomer is inhibited by admixing therewith at least one N-nitrosoarylhydroxylamine or a salt thereof. Specified stabilizers are N-nitrosophenylhydroxylamine, N - nitroso - 1 - naphthylhydroxylamine and N - nitroso - p - chloro or -p-bromophenylhydroxylamine and the sodium, potassium, iron, copper, titanium, vanadium, molybdenum, tin, ammonium and amine salts thereof. Examples describe the inhibition of polymerization in monomer latex systems comprising styrene/butadiene copolymer, styrene and popcorn seed polymer with (IV-VI) ammonium salt of N-nitrosophenylhydroxylamine, (VII) iron and copper chelates of N - nitrosophenylhydroxylamine, (VIII) ammonium salt of N-nitroso-1-naphthylhydroxylamine and (IX) myristylammonium, N-octylammonium and 1,4-dimethylheptyl-ammonium salts of N-nitrosophenylhydroxylamine; and the addition of ammonium, myristyl-ammonium, 1,4 - dimethylheptylammonium salts of N-nitrosophenylhdroxylamine to emulsion copolymerizations of butadiene and styrene in the presence of potassium disproportionated rosin soap, sodium alkylnaphthalene sulphonate, trisodium phosphate, sodium formaldehyde sulphoxylate, ferrous sulphate, p-menthane hydroperoxide, sodium ethylenediamine tetraacetate, t.-dodecyl mercaptan and sodium hydrosulphite.ALSO:The growth of undesirable polymer in ethylenically unsaturated hydrocarbons and in drying and semi-drying oils is inhibited by admixing therewith at least one N-nitrosoaryl-hydroxylamine or a salt thereof. Preferred nitroso compounds are N-nitrosophenyl-hydroxylamine and N-nitroso-1-naphthylhydroxylamine, and the ammonium, amine, sodium, potassium, iron, copper, titanium, vanadium, molybdenum and tin salts. Materials which may be stabilized include mono-olefins, conjugated di-olefins, vinyl aromatic hydrocarbons and tung, corn, soybean, linseed, fish, perilla and dehydrated castor oils. Examples describe the stabilization of (I,III-VI and XI) styrene, (II) a mixture of styrene and butadiene and (X) isoprene, butadiene, vinyl naphthalene, propylene, butene-1, butene-2, octene-1, n-octadecene-1, tung oil and linseed oil with the ammonium salt of N-nitrosophenylhydroxylamine; and of styrene with (VII) iron and copper chelates of N-nitrosophenylhydroxylamine, (VIII) N-nitroso-1-naphthylhydroxylamine and (IX) myristylammonium, N-octylammonium and 1,4-dimethylheptyl ammonium salts of N-nitrosophenylhydroxylamine.ALSO:The growth of undesirable polymer in ethylenically unsaturated esters is inhibited by admixing therewith at least one N-nitrosoaryl-hydroxylamine or a salt thereof. Preferred nitroso compounds are N-nitrosophenyl-hydroxylamine and N-nitroso-1-naphthylhydroxylamine and ammonium, amine, sodium, potassium, iron, copper, titanium, vanadium, molybdenum and tin salts. Many allyl, methacrylic, crotonic, cinnamic, maleic and fumaric esters are specified and examples describe the stabilization of (X) methyl methacrylate, allyl maleate, allyl cinnamate, allyl oxalate and allyl fumarate with the ammonium salt of N-nitrosophenylhydroxylamine.