| 摘要 |
1300820 Regenerated cellulose microfibres MITSUBISHI RAYON CO Ltd 21 Oct 1970 [24 Oct 1969] 49965/70 Heading B5B [Also in Divisions D1 and D2] A fibrous product comprising a large number of regenerated cellulose fibril-like microfibres having a diameter of 0À1 to 5 microns, at least a portion of said fibril-like microfibres being mutually entangled may be prepared by a process in which a coagulation liquid is ejected at a high flow rate through inner tube 1 of an aspirator-type spinning apparatus (Fig. 3) and a viscose spinning solution is introduced (by a Venturi effect or under pressure) through pipe 2 and is coagulated under conditions of high stress in the narrow portion of the apparatus c, the resultant mixture of coagulation liquid and microfibrous product being discharged through discharge pipe 3. Preferably the coagulation liquid is an aqueous solution containing an acid (e.g. H 2 SO 4 ) with or without formaldehyde and/or a hydrophilic solvent, suitably acetone, ethyl, methyl or propyl alcohol, THF or dioxane. The viscose spinning solution or the coagulation liquid may additionally contain other organic materials, preferably of synthetic polymers in the form of cut fibres, granules or flakes, or inorganic materials, when the fibrous product of the invention also contains these added materials. Examples relate to the production of fibrous products consisting of regenerated cellulose microfibres alone or from viscose spinning solutions containing a granulated ethylene-vinyl acetate copolymer, aqueous emulsions of vinyl acetate/ ethylene copolymers, hydrophilic solvent solutions of polyvinylchloride or polyethylene, or aqueous dispersions of powdered polytetrafluoroethylene, bleached tree pulp or glass fibre strands or from viscose spinning solutions coagulated with an acidic coagulation liquid containing granulated kaolin, dried flakes of cellulose diacetate or cut acrylic fibres. The fibrous products were subjected to conventional regeneration, scouring and drying treatments, and made into non-woven fabrics by defibrating and paper-making operations (Details D1-D2 Abridgment]. |
