| 摘要 |
Flame-resistant articles are produced from a spinning solution comprising (1) an acrylonitrile polymer containing at least 85% acrylonitrile, any balance being another monoethylenically unsaturated monomer, dissolved in (2) an aqueous saline solution having dispersed therein (3) at least 10%, based on the weight of polymer, of a mixture comprising (a) a polybromocyclohexane having at least 3 bromine atoms in the molecule providing at least 3.5% Br2, based on the polymer weight and (b) a substantially water-insoluble calcium phosphate, the weight ratio of bromine to calcium phosphate being from 0.7:1 to 5.5:1. Zince chloride is the preferred saline solute. Specified acrylonitrile copolyers are those with vinyl chloride, vinyl acetate, methyl or other alkyl (meth)acrylates, the vinyl pyridines and allyl alcohol. The polybromocyclohexane may be tribromotrichlorocyclohexane, tetrabromodichlorocyclohexane, pentabromomonochlorocyclohexane or hexabromocyclohexane, or mixtures thereof. Tricalcium phosphate, calcium pyrophosphate and calcium metaphosphate are the phosphates specified. A surface-active agent, e.g. a cationic, 70% active, reaction product of ethylene oxide, octadecylamine, octadecanoic acid and octadecyl guanidine may be incorporated in the spinning solution, as can plasticizers, lubricants, dyes and pigments. In the example varying percentages of pentabromomonochlorocyclohexan and tricalcium phosphate are mixed with an equal weight of an aqueous ZnCl2 solution of polyacrylonitrile and with 2% of the said surfactant. These concentrates are ground prior to mixing with further portions of the polyacrylonitrile solution and films are prepared from the resulting samples (see Division B5).
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