| 摘要 |
<p>Porous acrylic and modacrylic fibre having a porosity above 0.3 cm<3>g<-><1>, an internal surface area of at least 50 m<2>g<-><1> (when its decitex is greater than 2.5) or at least 35 m<2>g<-><1> (when its decitex is not more than 2.5), and a water imbibition of at least 65% (when its decitex is greater than 2.5) or at least 55% (when its decitex is not more than 2.5) and other porous acrylic and modacrylic fibre can be produced by contacting never-dried, standard wet-spun fibre with a water-miscible organic liquid which is a non-solvent for the fibre and has a boiling point below the glass transition temperature of the fibre to exchange the water in the fibre for the organic liquid, and then drying the fibre so as to remove the organic liquid without collapsing the fibre. Porous fibre made in this way or other porous acrylic or modacrylic fibre in dry or never-dried state can be impregnated with an additive either by immersion in a solution of the additive in an organic liquid of the above type or by immersion in a solution or liquid dispersion of the additive in a different liquid followed by exchange of that liquid with an organic liquid of the above type, followed in either case by drying to remove the liquid. The drying conditions can be controlled to provide uncollapsed fibres, fully collapsed fibres or, preferably, novel partially collapsed fibres, from which the additive is released in a sustained fashion at a rate determined by the degree of collapse of the fibres.</p> |
