Patent GB-474390-A (GB)
Title: Improvements in the manufacture of textile materials, foils and the like containing organic derivatives of cellulose
IPC: D01F2/28
Filed: 1936-04-29
Abstract: Processes of esterification of textile materials having a basis of an organic derivative of cellulose in a liquid which is a non-solvent for the materials, are carried out on staple fibres or spun yarns containing such fibres, or on mixed yarns, fabrics, or other materials containing cellulose organic derivative filaments and other filaments.  According to another modification, the radicle of an organic acid is introduced into textile materials, foils, films, and the like having a basis of an organic derivative of cellulose with the aid of an anhydride which contains the radicle of a different organic acid and which is dissolved in a liquid medium which is a non-solvent for the materials.  The treatment results in products of improved resistance to moisture, of higher ironing-point, of different affinities for dyestuffs, and of different solubilities from those of the starting materials.  When mixed materials are used, cotton fibres or short or long filaments of regenerated cellulose may be associated with the cellulose derivative filaments.  The acetylating bath may contain acetic anhydride, or other anhydride of a lower fatty acid, ferric chloride and hydrogen chloride, dissolved in benzene, toluene or xylene, or carbon tetrachloride.  If desired, the material may be pretreated by immersing it in benzene or carbon tetrachloride containing the catalyst.  Perchloric acid or a halide of tin, or zinc, may be used instead of ferric chloride as catalyst. When spun yarns are used they may consist entirely of cellulose derivative fibres or they may contain also cotton or other natural cellulosic fibres or regenerated cellulose fibres. The staple fibres may be obtained by dry spinning, and they may have been subjected to stretching or shrinking operations. Esterification may be carried out with aid of an anhydride, acid chloride, or organic acid together with an anhydride.  Swelling agents such as methylene chloride may be present in the esterifying medium.  Yarns having a basis of a cellulose derivative may be treated in presence of a catalyst with acetic anhydride and propionic acid or with acetic-propionic anhydride. The materials may be reacted with an organic acid and chloracetic or methoxyacetic anhydride, or other anhydride which does not itself esterify under the conditions employed.  In an example, a mixed yarn of viscose filaments and stretched cellulose acetate filaments is treated with a mixture of carbon tetrachloride, acetic anhydride and chloride, and ferric chloride.  In another example, cellulose acetate staple fibre yarn is treated with benzene, acetic anhydride, ferric chloride, and hydrogen chloride. In another example, cellulose acetate yarn is treated with carbon tetrachloride, glacial acetic acid, chloracetic anhydride, acetyl chloride, and ferric chloride.  The products may be used in insulating electric conductors or other materials.  Specifications 424,830, 438,584, 438,585, 438,586, 438,587, 438,655, 438,656, 443,707, 448,816, 448,817, 448,917, and 463,323 are referred to.