МЕТОД ЗА ПОЛУЧАВАНЕ НА ТРУДНОВЪЗПЛАМЕНИМИ НИШКИ, ВЛАКНА И ФОЛИЯ

1286381 Flame-resistant filaments GLANZSTOFF AG 23 March 1970 [2 May 1969] 13876/70 Heading B5B [Also in Divisions C3 and D1] Flame-resistant cellulosic filaments, fibres, threads and films are prepared by shaping a mixture of viscose and at least one polyacyloxalamidrazone, having recurring units of formula wherein R represents a straight or branched chain saturated or unsaturated aliphatic radical containing 2 to 12 C atoms or a cycloaliphatic, araliphatic, aromatic or heterocyclic radical, into an acid precipitation bath and reacting the resultant shaped article, which preferably contains between 25% and 50% by weight of the polyacyloxalamidrazone, with a solution of one or more compounds of the metals Zn, Sn, Cd, Ba, Sr, Ca, Sb or Ta dissolved in water, dilute aqueous acid or base, or organic solvents. The shaped article may then be washed and dried. The polyacyloxamidrazones are prepared by reacting oxalic acid bisamidrazone with a diacid chloride or bromide of a dicarboxylic acid, preferred acids being terephthalic acid and fumaric acid. Examples relate to the spinning of filaments from viscoses containing polyterephthaloyloxamidrazone, polyadipinoyloxalamidrazone or poly-2,6-pyridinoyloxalamidrazone into acid baths containing sodium and zinc sulphates, the filaments are then washed, dried and then immersed in aqueous baths containing zinc chloride, stannous chloride or calcium hydroxide. Example 1 also describes delustring of the dried filaments, prior to their immersion in the metal salt solution, using an aqueous solution of Marseilles soap at 50-60‹ C.