| 摘要 |
1,096,873. Producing #-polyamide filaments. FARBWERKE HOECHST A.G. April 15, 1965 [April 18, 1964], No. 16302/65. Heading B5B. A solution of 5 to 50% by weight concentration of a polymer of a #-lactam monosubstituted in the 4-position, the polymer being dissolved in a water-soluble acid is spun into an aqueous coagulation bath and the filaments after they have left the coagulation bath are drawn 3 to 15 times their original length. The temperature of the bath may be 5‹ to 50‹ C. The drawing of the filaments may be effected in water at 50‹ to 90‹ C. The drawn filaments may be heatset in air at 60‹ to 300‹ C. The heat-setting may be effected on a rigid bobbin on which the drawn filaments have been wound. The polymer may have the general formula wherein R, R<1> and R<11> each represent an alkyl group having 1 to 18 carbon atoms, an aryl, aralkyl or cycloalkyl group and R<1> and R<11> may alternatively each represent a hydrogen atom. The polymer solvent may be sulphuric, phosphoric, nitric, acetic, formic, thioglycolic, mono-, di- or trichloro-acetic, trifluoroacetic, lactic, pyroracemic or hydroxyethane sulphonic acid. Concentrated aqueous formic acid is preferred. The ball fall viscosity of the spinning solution at 20‹ C. (DIN Specn. 5401) may be 40 to 800 seconds. The relative viscosity of the polymers, measured in a solution of 1% concentration in concentrated sulphuric acid may be 2 to 300. The coagulating bath may consist of water or an aqueous salt solution of 0À1 to 50% concentration. The salt may be sodium, potassium or zinc chloride, or zinc or sodium sulphate. The filaments may be drawn in water at 5‹ to 100‹ C., preferably 10‹ to 30‹ C., or in air, and may be heat set at 60‹ to 300‹ C. In an example, a solution of 15 parts by weight concentration of poly - 4 - methyl - azetidin - 2 - one (having a relative viscosity of 14À1) in 96% formic acid is splun into an aqueous 16% solution of sodium chloride at 21‹ C. The filament is then drawn to four times its original length in a bath of water at 25‹ C. and heat set under tension by passage over metal plates maintained at 230‹ C.
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