Patent GB-713049-A (GB)
Title: Improvements in or relating to solutions of acrylonitrile polymers
Inventor: KOWOLICK ERNEST JAN
IPC: C08K5/32
Filed: 1951-05-23
Abstract: Homogeneous compositions, substantially free from dihydric phenols, are made from acrylonitrile polymers and a nitrosamine which is stable at temperatures up to 120 DEG C., which contains more than two carbon atoms in the molecule, and which belongs to one of the following classes: (a) compounds in which the ratio of the number of nitrosamino groups to the number of carbon atoms in the molecule is not lower than 1:3, (b) compounds in which said ratio is lower than 1:3 but not lower than 1:4, and in which the amino nitrogen atom of the nitrosamino group forms part of a saturated or unsaturated ring, (c) compounds in which said ratio is not lower than 1:6, and which contain, besides a nitrosamino group or groups, an auxiliary solvogenic group or groups (i.e. a solution promoting group such as oxygen, sulphur, or nitrogen as ring atoms, and nitrile amide, nitro, and carbonyl groups), the ratio of the total number of nitrosamino and auxiliary solvogenic groups to the number of carbon atoms not forming part of a solvogenic group being not lower than 1:3, and (d) compounds in which the ratio of the number of nitrosamino groups to the number of carbon atoms in the molecule is not lower than 1:6 and the amino nitrogen atom of a nitrosamino group forms part of a saturated or unsaturated ring, and which contain one or more auxiliary solvogenic groups, the ratio of the total number of nitrosamino and solvogenic groups to the number of carbon atoms not forming part of a solvogenic group being lower than 1:3 but not lower than 1:4.  Polymers specified are polyacrylonitrile and copolymers of acrylonitrile with vinyl acetate, morpholino-ethyl vinyl ether, styrene, methyl and phenyl acrylates, vinyl and vinylidene chlorides, 2- vinyl pyridine, and 2-methyl-5-vinyl pyridine. Nitrosamines specified are N-nitroso-trimethylene -imine, 1-nitrosopyrroline, N,N1-dinitroso-N,N1-dimethylethylene diamine, N,N1-dinitroso-N,N1-dimethyltrimethylene diamine, N,N1-dinitroso-N,N1- dimethyltetramethylene diamine, N,N1 - dinitroso - N,N1 - diethylethylene diamine, N - nitroso - N - ethylamino aceto-nitrile, nitroso-imino diacetonitrile, N-nitroso-N-butyl urea, N - nitroso - alpha - pyrazolidone, 1-nitroso-3-nitro pyridine, 2-nitroso-1 - ethyl-3-methyl pyrazolidone-5, N-nitroso morpholine, N-nitroso thiomorpholine, N-nitroso-N-ethyl aminoacetamide, nitroso-imino diacetamide, 3 - nitroso-2, 5 - bis - methylimino - 1, 3, 4-thiodiazolidine, dinitrosopiperazine, 3-nitroso-4, 6, 6 - trimethyl - 2 - ethyl - tetrahydro - 1, 3-oxazine, 3 - nitroso - 4, 4, 6 - trimethyl - 2-isopropyl - tetrahydro - 1, 3 - oxazine, 2, 3 - bis (ethylnitrosamino) butane, 2, 21-bis-alphapyridyldiethylnitrosamine, and N-nitroso-bis- 2- nitrobenzylamine.  Also present may be other substances such as water, methanol, ethanol, ether, chloroform, dimethyl formamide, sulpholane, butyrolactone, valerolactone, maleic acid, maleic, succinic, and glutaric anhydrides, nitromethane, cyclic ethylene glycol carbonate, ethylene cyanhydrin, nitro-ethanol, and meta and para nitrophenols.  The compositions of the acrylonitrile polymers and the higher melting point nitrosamines may be employed for preparing fibres by the melt spinning method, whilst solutions of the polymers in the nitrosamines of lower melting point may be wet-spun into fibres by the methods described in Specifications 711,344 and 712,984.  The fibres produced may be stretched by the process described in Specification 636,476. Specification 712,986 also is referred to.  The Provisional Specification describes also the use of dihydric alcohols, such as resorcinol and catechol, in conjunction with the nitrosamine solvents.