GB397881A - Improvements in the manufacture and treatment of filaments and the like - Google Patents

Abstract

The stretching of artificial filaments, yarns, ribbons, and like materials, made from or containing cellulose acetate or other film-forming substances which are relatively resistant to penetration by water, is facilitated by stretching materials from which an additional substance has been removed before or during the application of the stretch-assisting agent. The additional substance is defined as a substance of different nature from the base of the materials and from the solvent or other substance which is removed from the spinning solution or like composition in order to form the materials, and examples of such substances are glycerine, cyclohexanol, cyclohexanyl acetate, methyl cyclohexanol, methyl cyclohexanyl acetate, cyclohexanone, methyl cyclohexanone, cyclobutanone, acetyl acetone, ethers of olefine and polyolefine glycols, benzyl alcohol, benzyl acetate, ethyl oxybutyrate, diacetin, triacetin, tribenzoyl glycerine, triphenyl and tricresyl phosphates, diethyl and dibutyl phthalates, diethyl and dibutyl tartrates, paratoluene sulphonamide and sulphonanilide, oils, fats, and waxes. The additional substance may be wholly or partly dissolved out by suitable liquids which may or may not have a solvent action on the substance of the materials. In wet spinning processes, a volatile additional substance insoluble in the coagulating bath may be employed, and subsequently removed from the materials by the action of heat. If the liquid used to eliminate the additional substance from the filaments is itself a relatively strong swelling agent for the substance of the filaments, it may be unnecessary to treat again with a stretch-assisting agent, the stretching operation being, for example, continuous with the removal of the additional substance by means of a liquid having swelling properties. The stretching may be effected on the filaments &c. in hank form as in Specification 277,089, [Class 2 (ii), Cellulose &c.], or may be conducted on the travelling filaments as in Specification 323,790, [Class 2 (ii), Cellulose &c.], or intermittently stretching may be employed as is described in Specification 370,430. In examples, (1) an aqueous acetone solution of cellulose acetate containing 10 per cent of triphenyl phosphate is spun, and the filaments stretched by the process of Specifications 277,089, 323,790, or 370,430, after first removing the triphenyl phosphate by means of a bath of benzene; (2) an aqueous acetone solution of cellulose acetate containing 8-12 per cent of diethylene glycol monobutyl ether is dry-spun, and the filaments are passed through a bath of 40 per cent aqueous acetone to remove the ether and to soften them, after which they are stretched to 200-400 per cent or more of their original length. According to the Provisional Specification, the process is applicable to the production of filaments and the like of regenerated cellulose from viscose, cuprammonium cellulose, and nitrocellulose. Specifications 391,829, 392,186, 392,191, 396,761, and 400,180, also are referred to.