A method for dealkalization of poly saccharide xanthate solutions and entalkalisierte poly saccharide xanthogenate

摘要

Decausticized viscose is used as a temporary soil binder. It can be used for preparing concrete or as an adjunct to other concrete binders (Example 58). For the method of preparation of the decausticized viscose, see Division C3. U.S.A. Specification 2,705,231 is referred to.ALSO:A decausticized solution of a polysaccharide xanthate is made by subjecting a crude caustic aqueous solution of an alkali xanthate of a film-forming polysaccharide to ion-exchange or ion-retardation or a combination thereof, to remove a substantial proportion of the free caustic therein. Viscose or amylose xanthate may be so treated. A decausticized viscose substantially free of alkali cellulose and free cellulose may be made by contacting an aqueous viscose solution with sufficient cation-exchange material in the hydrogen ion form to neutralize a substantial proportion of the alkali content of the viscose. A decausticized amylose xanthate substantially free of alkali amylose and free amylose may be made by an analogous method. Thus a predetermined amount of cation-exchange material may be mixed with the viscose at ambient temperature until reaction is complete and the cation exchange material is separated by settling or filtration. Alternatively the viscose may be passed through a column containing the cation-exchange material. In further methods the viscose is passed through a column containing either an anion-exchange material in the salt form or an ion-retarding resin, the effluent in either case comprising decausticized viscose having a pH less than 13. Similarly, decausticized amylose xanthate substantially free of alkali amylose and free amylose may be made by passing an aqueous amylose xanthate solution through a column containing an anion-exchange material in the salt form and recovering the effluent comprising decausticized amylose xanthate. In any of the preceding methods, the solution may be partially dealkalized by dialysis prior to the ion-exchange or ion-retardation treatment. Decausticized aqueous solutions of film-forming polysaccharide xanthates so obtained, e.g. of viscose or amylose xanthate, are of pH 4-13 and substantially free of regenerated polysaccharide. Specified products include decausticized viscose of pH 8-13 substantially free of regenerated cellulose and alkalization and xanthation by-products and containing sodium salts in an amount substantially equivalent to the free alkali content of the viscose when initially formed; decausticized viscose of pH 4-8 substantially free of regenerated cellulose and containing xanthic acid groups in excess of 40% of the xanthate content of the viscose; and analogous amylose xanthate products. A wide range of natural and synthetic ion-exchange materials may be used. Preparation of the decausticized viscose is described in Examples 1-4, 6-9 (cation-exchange), 10, 12-14 (anion-exchange), 15 (ion-retardation), 17 (liquid ion-exchanger), 19, 20 (dialysis followed by cation-exchange), 21 (anion-exchange followed by cation-exchange), 22 (cation-exchange followed by anion-exchange), and 23 (mixed-bed ion-exchange). Preparation of the decausticized amylose xanthate is described in Examples 5 (cation-exchange), 11 (anion-exchange), 16 (ion-retardation), and 18 (dialysis followed by cation-exchange). In Example 36, unidentified cellulose derivatives are obtained by treatment of the decausticized viscose with phenyl isocyanate or with adipoyl chloride. In Example 38, cyanoethylation and carbamoethylation of decausticized viscose are disclosed. Example 52 discloses the preparation of ammonium cellulose xanthate and the corresponding lithium and potassium salts by passing decausticized viscose through a cation-exchange resin in the ammonium form. Example 55 discloses etherification and esterification of decausticized viscose with chloracetic acid and adipoyl chloride respectively. Example 40 discloses the preparation of a dispersion comprising a mixture of nylon and graft polymers of nylon and cellulose by treatment of a mixture of decausticized viscose and hexamethylene diamine with adipoylchloride in carbon tetrachloride solution. U.S.A. Specification 2,705,231 is referred to.ALSO:Decausticized viscose is used as a pigment binder in ink formulations for printing on regenerated cellulose. Heat-treatment after printing converts the viscose into regenerated cellulose. In Example 29, a black ink formulation is made from carbon black and decausticized viscose and used to print regenerated cellulose meat casings, which are then cured by heating at 115 DEG C. For the method of preparation of the decausticized viscose, see Division C3. U.S.A. Specification 2,705,231 is referred to.ALSO:Decausticized solutions of polysaccharide xanthates, especially amylose xanthate and viscose, are used as coating materials, subseqquent thermal regeneration thereof yielding amylose or regenerated cellulose. For the method of preparation of the decausticized solutions (see Division C3). Example 24 describes the coating of hemp paper, starch-sized onion skin paper, rayon-hemp paper and wood pulp paper, with decausticized viscose, followed by drying at 80-100 DEG C. or at 180 DEG C. to obtain papers having high dry and wet strengths. Example 26 describes the use of decausticized viscose as an adhesive in seaming flat cellulose impregnated paper to form tubes. In Example 28, decausticized viscose is sprayed over a freshly printed surface of a cellulose casing and dried at 105 DEG C., to prevent smudging and offsetting of the printed matter. Example 39 discloses the use of decausticized viscose as a coating for thermoplastic film to impart adhesivity to regenerated cellulose and so permit heat sealing of the cellulose film to another object. In Example 44, a bast fibre paper is coated with decausticized viscose and regeneration is effected by standing or drying at 100 DEG C. Example 47 discloses the use of a coating of decausticized viscose, reacted with chloracetic acid, as an ultra-violet barrier. Example 48 discloses the coating of cellulose acetate and polyethylene terephthalate films with decausticized viscose to improve printability. Examples 50, 51 and 54 disclose the coating of nylon or "Dacron" (Registered Trade Mark) fibres, wool, silk, and cellulose esters and ethers with decausticized viscose to produce a regenerated cellulose coating. Example 56 discloses the use of decausticized viscose as a binder in the formation of non-woven textiles from glass, nylon, cellulose acetate and "Mylar" (Registered Trade Mark) fibres. Example 57 discloses the use of decausticized viscose as a protective coating for glass. U.S.A. Specification 2,705,231 is referred to.ALSO:Paper and textile materials are treated with decausticized solutions of polysaccharide xanthates, especially amylose xanthate and viscose, thermal regeneration of which yields amylose or regenerated cellulose. For the method of preparation of the decausticized solutions see Division C3. Example 30 discloses the sizing of cotton muslin in decausticized viscose, followed by air drying and force drying at 80 DEG C. Example 38 discloses the use of a decausticized viscose previously subjected to cyanoethylation or carbamoethylation as a water-regain or static-reducing additive on polyester fibres. Example 50 discloses the coating of nylon fibres with decausticized viscose to produce a composite fibre having a regenerated cellulose coating. Example 56 discloses the use of decausticized viscose as a binder in the formation of nonwoven textiles from glass, nylon, cellulose acetate and "Mylar" (Trade Mark) fibres. Example 24 describes the impregnation of hemp paper, starch sized onion-skin paper, rayon-hemp paper, and wood-pulp paper, with decausticized viscose, followed by drying at 80-100 DEG C., or at 180 DEG C., to obtain papers having high dry and wet strengths. Example 27 describes the impregnation of tissue paper with decausticized viscose, or amylose xanthate, the impregnated paper being formed into tubes and regenerated thermally or in an acid bath. Example 45 discloses the use of decausticized viscose in admixture with paper pulp in the formation of paper to promote the exhaustion of basic resins into the paper, and the use of decausticized viscose as a beater additive. Examples 50, 51 and 54 disclose the coating of nylon, "Dacron" (Trade Mark), wool, silk, and cellulose ester and ether fibres with decausticized viscose to produce a regenerated cellulose coating. U.S.A. Specification 2, 705, 231 is referred to.