Patent GB-748393-A (GB)
Title: Process for the manufacture of easily dyed acrylonitrile polymers and shaped structures therefrom
Inventor: SCHLACK PAUL
IPC: C08F8/32
Filed: 1951-11-30
Abstract: Dyeable acrylonitrile polymers are made by treating acrylonitrile polymers containing imide groups with a polyvalent amine which contains at least one amino group capable of being acylated.  Imide groups may be introduced into the acrylonitrile polymers by (a) heating to a high temperature such as 130-180 DEG  C., before or after a shaping operation, copolymers of acrylonitrile containing free carboxyl groups, e.g. in the form of copolymerized acrylic or methacrylic acid, the reaction being accelerated, if desired, by the use as a catalyst of an acid or an acid forming agent; the process may also be applied to copolymers or mixture of polymers containing amide groups in addition to the carboxyl groups, e.g. in the form of acrylamide, methacrylamide, and acrylic acid methylamide; (b) a process similar to that in (a) above applied to copolymers of acrylonitrile and vinyl-carboxylic acid amides; (c) heating acrylonitrile polymers, particularly those containing minor proportions of copolymerized vinyl-carboxylic acid amides, with a carboxylic acid having a dissociation constant K > 1 X 10-4; (d) treating copolymers of acrylonitrile containing amide groups with acylating agents containing the group - NCO or capable of forming that group by thermal decomposition, e.g. isocyanic acid, isocyanates, phenyl N-ethyl carbamate, N-(N1-ethylcarbamyl)-alpha-pyrrolidone, benzazide, salts of urea, nitrourea, and mustard oils, and acid anhydrides and halides, and ketenes; (e) treating acrylonitrile polymers containing free carboxyl groups with carbo-di-imides; and (f) copolymerizing acrylonitrile with monomers containing imide groups such as itaconimide, acrylyl urea, N-acrylyl-N1-alkyl urea, N-acrylyl urethanes, N-acrylyl isobutyramide, and the vinyl ether of glycolic acid ureide.  The treatment of the imide group containing polymers with polyvalent amines may be carried out by adding the amine to a solution of the polymer followed, if necessary, by heating, or by treating the polymer, if desired, in shaped form, with a solution or the vapours of the amine; shaped articles, e.g. films, when treated are preferably first oriented by stretching and then, if required, reshrunk.  In another mode of operation the amines are employed in the form of their salts which are added to solutions of the polymers which are then formed into shaped articles which are subsequently treated with a solution of an alkali.  Amines specified are: ethylene diamine, beta-diethylaminoethylamine, gamma-(dimethylamino)-propylamine, hexamethylene diamine, diethylene triamine, triethylene tetramine, piperido - ethylene amine, N - gamma - aminopropyl - morpholine, 1:4:7 - triaminoheptane, N - di - (beta - diethylaminoethyl) amine, piperazine, the reaction product of tetramethylene diamine or hexamethylene diamine with ethylene bromide, polyethylene imines, the amine produced by reacting propionitrile and acrylonitrile in the presence of an alkali metal and then reducing the product, the hydrolysis product of poly-N-vinyl succinimide, and amines containing mercaptan groups such as N - (beta - mercaptoethyl) - ethylene diamine, N - (beta - mercaptoethyl) - hexamethylene diamine, and N-mono-(beta-mercaptoethyl)-piperazine. The treatment with mercapto-amines leads to the formation of cross-linkages and is preferably carried out in the presence of a reducing agent such as a hydrosulphite or thioglycollic acid.