GB1290717A - - Google Patents

Abstract

1290717 Conjugate acrylic filaments MITSUBISHI RAYON CO Ltd 27 April 1970 [26 Sept 1969] 20071/70 Heading B5B An acrylic crimped composite fibre is formed from two polymer components, one being an acrylonitrile-methacrylonitrile copolymer containing from 5 to 50% by weight of methacrylonitrile, the other being a copolymer containing from 93 to 99À7% by weight of acrylonitrile and from 0À3 to 7% by weight of a monomer having a strong acid group in either the salt or the free acid form, the acrylonitrile-methacrylonitrile copolymer component being positioned on the outside of the crimps and the component containing the strong acid groups being positioned on the inside of the crimps. The acrylonitrile methacrylonitrile copolymer preferably contains from 7 to 30% of methacrylonitrile and may contain a third component which is either basic or acidic. Examples of the latter are sodium methallyl sulphonate and sodium vinyl benzene sulphonate and of the former 2-vinylpyridine and 2-methyl-5-vinylpyridine. These components serve to enhance the dyeability of the fibres. The monomer containing the strong acid group may be either of the two above or sulphophenyl methallyl ether or sulphophenyl methallyl amide or salts of these. The copolymer containing these may also contain methyl methacrylate, vinyl acetate or another suitable monomer with a view to rendering the copolymer more soluble and the spinning solution more stable. The copolymers are dissolved separately in a suitable solvent, such as dimethylformamide, and conjugately spun into a composite filament of either the side-by-side type or the asymmetric sheath-core type by a dry-spinning technique. The filament thus obtained is drawn in a hot water bath and the drawn wet filament dried in an atmosphere maintained at a dew-point and a dry-bulb temperature within a range enclosed by lines connecting A, B, C, D, E and F, preferably A, B, E and F, in Fig. 2. Optionally, the wet drawn filaments are additionally crimped in a stuffer box before drawing. Since both components of the composite fibre have high Young's moduli, the fibre has good crimp stability. The fibres also exhibit colour fastness and good anti-pilling behaviour and retain a good hand feel after washing. Specifications 1,235,021 and 1,290,716 are referred to.