Patent GB-859506-A (GB)
Title: Stabilized acrylonitrile polymers
IPC: C08K5/524
Filed: 1957-05-06
Abstract: A composition comprises a polymer containing at least 80% of acrylonitrile, a solvent therefor, and an inhibiting agent of the group consisting of (A) a reagent comprising an inorganic acid having an ionization constant greater than 1,186 X 10-5 and preferably greater than 1 X 10-4 and a substance of the group consisting of dicyclopentadiene, phenolphthalein, cumene, glycolic acid, ethylene diamine tetra-acetic acid, a mixture of glycolic acid and ethylene diamine tetra-acetic acid, a mixture of glycolic acid and the sodium and acid salts of ethylene diamine tetra-acetic acid, tricresyl phosphate, an organic metal sulphoxylate of the general formula: <FORM:0859506/IV(a)/1> where R is an alkanol group containing 1 to 3 carbon atoms, an acyl group containing 1 to 3 carbon atoms or an aryl group containing 6 to 8 carbon atoms, n is 1 or 2 and M is sodium, potassium or zinc, a heterocyclic ring compound having the general formula:  <FORM:0859506/IV(a)/2> where R is -CH2- or oxygen, and an aldehyde of the group consisting of formaldehyde, acetaldehyde, acrolein, propionaldehyde and benzaldehyde; (B) a three component reagent in which one component is formaldehyde or acrolein, the second component is an inorganic acid having an ionization constant greater than 1 X 10-4 and the third component is a compound selected from the group consisting of ethylene diamine tetra-acetic acid, the sodium salt of ethylene diamine tetra-acetic acid, the disodium acid salt of ethylene diamine tetra-acetic acid, hydroxylamine sulphate, ethylacetoacetate, acetophenone zinc dicetyldithiophosphate, alkalimetal hydrosulphites, zinc hydrosulphite, sodium bisulphite, sodium phosphate, tricresyl phosphate, an organic metal sulphoxylate of the above formula, tris (hydroxy methyl) phosphonium oxide and a compound of the general formula:  <FORM:0859506/IV(a)/3> where R is hydrogen, methoxy, ethoxy or OH and (C) a three component reagent in which one component is an organic metal sulphoxylate of the above formula, the second component is an inorganic acid having an ionization constant greater than 1 X 10-4 and the third component is a compound selected from the group consisting of ethylene diamine tetra-acetic acid, a sodium salt or acid salt thereof, sulphonic, phosphoric, oxalic, tartaric or citric acid, zinc dicetyl dithiophosphate, trisodium phosphate, trisodium pyrophosphate, phosphorous pentoxide, N-formyl pyrrolidine and a heterocyclic ring compound having the general formula:  <FORM:0859506/IV(a)/4> where R is CH2 or NCHO.  The polymer may be polyacrylonitrile or a copolymer of acrylonitrile with one or more monomers such as acrylic, alphachloroacrylic and methacrylic acids, methyl, ethyl, butyl, methoxymethyl and betachloroethyl acrylate, methacrylate and alpha-chloroacrylate, vinyl chloride, fluoride bromide, acetate, chloroacetate, propionate and stearate, vinylidene chloride, 1-chloro-1-bromo-ethylene, methacrylonitrile, acrylamide, methacrylamide, alphachloroacrylamide, methyl vinyl ketone, N-vinyl phthalimide, N-vinyl succinimide, methylene malonic esters, itaconic acid and ester, N-vinyl carbazole, vinyl furane, vinyl sulphonic acid, diethyl citraconate or mesaconate, styrene, vinyl naphthalene, 2- and 4-vinyl pyridine, 2-methyl5-vinyl pyridine, 1-vinyl imidazole and 2-, 4-and 5-methyl-1-vinylimidazole, or may be a blend of polyacrylonitrile or of a binery copolymer of from 80 to 99% acrylonitrile and from 1 to 20% of at least one other monomer with from 2 to 50% of the weight of the blend of a copolymer of from 10 to 70% of acrylonitrile and from 30 to 90% of at least one other monomer, preferably one receptive to dyestuffs.  Solvents which may be used include N, N-dimethylformamide, N, N-dimethylacetamide, aqueous zinc chloride, sulphuric acid, aqueous nitric acid, aqueous sodium thiocyanate, ethylene carbonate, sulpholane and nitromethane. Inorganic acids which may be used include sulphuric, nitric, phosphoric and hydrochloric acid.