Zusammengesetzte Acrylfaser und Verfahren zu deren Herstellung

摘要

1290716 Composite acrylic filaments MITSUBISHI RAYON CO Ltd 12 Dec 1969 [25 Dec 1968 1 April 1969] 60744/69 Heading B5B The two components of a crimped, composite side-by-side type acrylic filament comprise (I) polyacrylonitrile (PAN) and (2) a copolymer of PAN with 5-50% by wt. of methacrylonitrile, component (1) being on the inside of the crimps. Component (1) may be a blend with up to 50% of a copolymer containing 94-99À7% acrylonitrile and 0À3-6% of a comonomer having a strongly acidic group, e.g. Na-methallylsulphonate. Other monomers, e.g. vinyl acetate, may also be present. Dry-spinning from DMF solution is specified, the filaments being drawn in boiling water and crimped by drying under no tension. Drying may be effected on filaments containing at least 10% water using temperature/humidity conditions within the broad range 10-180‹ C. (dry bulb) at dew-point 10-100‹ C. (see Fig. 7, not reproduced). The filaments may additionally be mechanically crimped and stapled. In Example 7, wet-drawn filaments are mechanically crimped, dried and then crimped with steam. The crimped tow so obtained is further drawn at 80‹ C., recrimped mechanically and stapled.