Patent GB-939196-A (GB)
Title: Process for the regulation of the elasticity moduli of highly elastic fibres and films
IPC: C08G18/10
Filed: 1961-07-14
Abstract: In the manufacture of fibres and films having an elastic elongation of 200-800% from polymers prepared in solution by the isocyanate polyaddition process, the spinning solution contains soluble and compatible substances capable of fixing the orientation of the stretched fibres or films, under action of heat and/or radiation, by condensation and/or free radical cross-linking.  The polymers are shaped to form fibres or films in known manner, and oriented by stretching and applying heat and/or radiation while in the stretched state.  Suitable "souble and compatible compounds" include polyisocyanates such as toluylene diisocyanates, urethdiones, thereof (see Specifications 779,070 and 783,564) 1,5-naphthylene diisocyanate, 4,41-diphenylmethane diisocyanate, thiophosphoric acid-(4,41,411-triphenylester-isocyanate), triphenylmethane-4,41,411-triisocyanate or reaction products of polyhydric alcohols with excess of polyisocyanates. Adducts of polyisocyanates with e.g. phenol, cresol, hydrocyanic acid, bisulphites, acetoacetic ester, malonic ester or acetyl acetone may be used.  Sulphurous acid may be added as a stabilizing agent.  Other suitable additives are formaldehyde and formaldehyde derivatives such as urotropic, methylal, urea-formaldehyde resins and semi-acetals of formaldehyde; polyols such as ethylene glycol, trimethylolpropane, and polymethylol ethers, e.g. melamine-hexamethylol-methyl ether or a copolymer of methyl methacrylate and methacrylamide-methylol-methyl ether. Further additives are triacryl formal, methylene bisacrylamide, diapoxides of glycols or diphenols, epichlorhydrin or a reaction product of g ,g -diamminopropyl-N-methylamine and diane bis-epoxide.  Polyfunctional compounds may be used e.g. ethylmethacrylate-a -isocyanate or mixtures of such compounds. Radical forming substances which may be added include di-tert-butylperoxide, dicumyl peroxide, dibenzoyl peroxide, dichlorobenzoyl peroxide, cumyl peroxide, perbenzoic acid, azo-compounds of the azo-isobutyric acid nitrile type, and Redox systems such as ferric compounds and peroxides.  When such radical cross-linking agents are used, the polymer is preferably provided with olefinic double bonds, a -carbonyl activated double bonds, tertiary carbon atoms or active methylene groups.  These may be achieved by using in the isocyanate polyaddition process such compounds as butanediol, maleic acid, dihydromuconic acid, acrylic and methacrylic acid diethanolamides, N-acrylicor N-methacrylic acid ethyl ester-N1-bisoxethylurea; oxyethylated dihydroxychalcones, 4,41-dioxethyl-distyryl ketone, (cinnamic acid-p-carboxylic acid-bisoxethyleste), 1,4-phenylene bisacrylic acid oxethyl ester, 4,41-bisoxethyl ether diphenylmethyl methane, 3-methypentane-2,4-diol, butane-1,3-diol, hexane-2,5-diol, 4,41-di-phenylmethane diisocyanate and 4,41-bisoxethyl ether diphenylmethane.  Substances containing vinyl or allyl groups may be incorporated into the polymer.  The cross-linking of the shaped polymer may be induced by heating, preferably for 5 to 60 mins. at 50 DEG -150 DEG C. or by irradiation with or without heating, from an ultra-violet source or a lamp of high candle-power, for at least 30 secs.  Sensitizers such as benzophenone may be added to the polymer solution, which may also include dyestuffs stabilizers and pigments such as titanium dioxide.  In an example, a polymer spinning solution made by treating the polyester of adipic acid and ethylene glycol with 4,41-diphenylmethane diisocyanate, and adding solutions of butane-1,4-diol, dimethyl cyclohexylamine, and diethanolamine in methyl ethyl ketone, is modified by incorporating the acetoacetic ester adduct of thiophosphoric acid-(4,41,411-tri-phenylester isocyanate).  The solution is spun into hot air, and is then heated on the spool at 120 DEG C. for 30 minutes.