GB469749A - Improvements in the production and treatment of artificial filaments, yarns and similar materials containing organic derivatives of cellulose - Google Patents

Abstract

Artificial filaments, foils, films, and similar materials made of organic derivatives of cellulose and containing plasticizers are subjected to stretching in wet steam or hot water at a temperature above 100 DEG C. Preferably, the plasticizers used are compatible with the cellulose derivatives in a proportion of at least 50 per cent. The filaments or foils may be of cellulose acetate, formate, propionate, butyrate, or nitro-acetate, or methyl, ethyl, or butyl cellulose, or ethyl or oxyethyl cellulose acetate. The plasticizer may be butyl or amyl phthalate, butyl citrate, glyceryl tri-benzoate, tri-phenyl or cresyl phosphate, but is preferably dibutyl or amyl tartrate, dimethyl or ethyl phthalate, di-(methyl or ethyl glycol) phthalate, triethyl citrate, cresyl glyceryl diacetate, methyl cyclohexanyl oxalate, benzyl benzoate, benzyl alcohol, triacetin, triphenyl acetin, or an aromatic sulphonamide. The plasticizer may be incorporated in a spinning solution or it may be incorporated in the filaments after they have been formed. Hanks or bobbins may be immersed in aqueous or organic solutions or emulsions of the plasticizer. Stretching may be carried out on hanks or while the materials are travelling, e.g. from the spinning cell to the winding device, and there may be one or more stages of stretching. The plasticizer may be removed during or after the stretching operation. Water, or aqueous solutions of alcohols, or organic solvents such as benzene toluene, dichlorethylene, carbon tetrachloride, alcohols, or ethers may be used for removing the plasticizer. In an example, cellulose acetate filaments are formed from a solution containing p-toluene sulphonamide as plasticizer, and passed through a chamber containing wet steam at a temperature above 100 DEG C., and are simultaneously stretched. In other examples, diethyl phthalate and triacetin are used as plasticizer. In another example, cellulose acetate foil containing diethyl phthalate and tri-phenyl phosphate is stretched in wet steam at 105 DEG C. Specifications 438,584, 438,585, 438,586, 438,587, 438,655, 438,656, 443,707, and 443,773 are referred to.