| 摘要 |
1,064,428. Polyacrylonitrile filaments. ASAHI KASEI KOGYO KABUSHIKI KAISHA. Nov. 19, 1964 [Nov. 21, 1963], No. 47176/64. Heading B5B. A method of producing filament yarns of acrylic polymers comprises extruding a solution of acrylic polymers containing at least 85% acrylonitrile into a liquid coagulating bath to form a plurality of filament yarns through a number of spinnerets mounted in spaced relation, washing the gelled filament yarns thus formed, subsequently stretching the same to a length at least four times the original length thereof, applying to the stretched filament yarns while still in the wet and swollen state less than 2% of their dry weight of a first agent as herein defined, thereafter subjecting the filament yarns to simultaneous shrinking and drying treatment to shrink the yarns by 5 to 20% along the fibre axis while maintaining the filament yarns in spaced relation by guiding the same with combs through a drier at a temperature of from 100‹ to 200‹ C., feeding the filament yarns into a sizing bath to apply to the filament yarns less than 10% of their dry weight of a sizing agent, drying the filament yarns under tension and at a temperature lower than that of the previous drying and shrinking treatment to stretch the same by up to 10% but less than the extent of the aforesaid shrinkage, and subsequently applying a finish oil and taking up the filament yarns. The first agent may be an oiling agent containing a surfactant, which is preferably non-ionic. Preferred surfactants include polyoxyethylene alkyl-ethers, polyoxyethylene alkyl phenols, polyoxyethylene alkyl esters and sorbitan alkyl esters. Desirably, the oiling agent has a melting point below 100‹ C. Alternatively the first agent may be a sizing agent, suitably polyvinyl alcohol, polyacrylic acid salts and copolymers of vinyl acetate and maleic acid, or may be a mixture of an oiling agent and a sizing agent. Said first agent may be in the form of an aqueous emulsion and/or an aqueous solution. The shrinking and drying treatment is preferably applied at a temperature within the range 110‹ C. to 180‹ C., and the sizing agent applied to the filament yarns after the shrinking and drying treatment is suitably selected from polyvinyl alcohol, polyacrylic acid salts and copolymers of vinyl acetate and maleic acid. In a preferred method, the said treatments of the filament yarns are performed while moving a number of such yarns in parallel to one another with small spacing therebetween, from the extrusion to the take up. Examples are given.
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