Patent GB-405275-A (GB)
Title: Improvements in or relating to the manufacture of artificial filaments, threads, yarns, ribbons and the like
IPC: D01F2/28
Filed: 1932-07-21
Abstract: In processes for the manufacture of artificial filaments, threads, yarns, ribbons, and the like containing cellulose acetate or other organic derivatives of cellulose wherein the materials are subjected to a stretching operation, di- or other polyglycerols, their condensation products, esters, ethers, or ether-esters, or the esters or ethers of such condensation products are used as treating agents incorporated in the materials before stretching.  Processes involving stretching to which the invention is applicable include such as are described in Specifications 277,089, 323,790, 336,217, [all in Class 2 (ii), Cellulose &c.], 340,324, 340,436, and 340,437.  The processes may be carried out either continuously with the production of the materials, whether by wet or dry spinning, as a separate operation while the materials are travelling from one point to another, or the materials may be treated in hank form.  Stretching may be effected in a single stage or in more than one stage as in Specification 370,430. It may also be applied to the treatment of yarns and the like in warp formation as described in Specification p  371,461.  When the process is carried out continuously with the production of the materials, the polyglycerine or similar compound may be incorporated in the dope itself or in the coagulating bath or in an after-treatment bath. Examples of suitable treating agents are diglycerine, the substance known as polyglyceryl acetate, the mono-, tri-, and tetra-acetates of diglycerine, the diethyl derivative of diglycerine trichlorhydrin the monoacetyl derivative of diglycerine trichlorhydrin, and the acetyl derivatives of triglycerine tetrachlorhydrin.  Further, condensation products of di- and other polyglycerols and esters and ethers of such condensation products may also be employed, for example, di-glycide, diacetyldiglycide (diglyceryl diacetate), and dibenzoyldiglycide (diglyceryl dibenzoate).  The treatment may be carried out at elevated temperatures, for example, at 80 to 100, 150, or even 200 DEG  C.  The substance is normally applied as a solution or dispersion in an aqueous or organic medium, the water naturally found in the hygroscopic di- and polyglycerines and their esters being in some cases sufficient.  Suitable diluents for use when moderate temperatures are employed are water and relatively low boiling organic liquids having no action on the cellulose derivative, for example, alcohol, ethers, and benzene, toluene, or other hydrocarbons.  At higher temperatures compounds such as amyl alcohol, tetrahydro- and decahydronaphthalene, high-boiling petroleum fractions, cyclohexane and xylene may be used.  Water and water-miscible liquids are normally the best suitable diluents for the polyglycerines and their ethers with lower alcohols, while water-immiscible liquids such as ethers are suitable with highly-etherified or esterified polyglycerines containing radicles of the higher alcohols or higher fatty acids.  Other substances which are solvents, latent solvents or swelling agents for the cellulose derivative may be employed in conjunction with the compounds used according to the invention, either in presence or absence of diluents.  Suitable compounds are acetone, diacetone alcohol, mono-or di-ethers or esters of olefine glycols or mixed ether-esters thereof, e.g. glycol mono-acetate and methyl glycol mono-acetate, dioxane, methylene ethylene oxide, methylene chloride and dichlorethylene. Such compounds may be applied simultaneously with the polyglycerine or similar compound, or as a separate operation.  The concentration of the polyglycerine or similar compound in the diluent, if such is employed, may be from 30 to 50 up to 70 per cent.  The polyglycerine or the like may be applied to the materials by passing them through or immersing them in baths, or by means of wicks or rollers, or by spraying or otherwise projecting the substance on the materials.  The application may take place prior to or simultaneously with stretching, and two or more softening treatments of different strength may be used as in Specification 392,185.  When application is simultaneous with the stretching, means may be employed to limit the action of the stretching force to the portion of the filaments or other materials already in a softened condition.  A shrinking process may be applied to the materials before or after stretching, as is described in Specifications 389,823 and 403,106.  Salts, sugars, or other polyhydric alcohols may be applied in the same or in subsequent treatment baths, as described in Specifications 343,062, 391,158, and 391,480.  The filaments may be partially or completely saponified, for example, with aqueous or alcoholic solutions of caustic alkali, as described in Specifications 402,104 and 402,141.  The use of the cyclic ethers or esters obtainable by the condensation of a trihydroxy alcohol with a di- or tri-hydroxy alcohol as treating agents is excluded from the scope of the invention.  Examples are given.  Specifications 367,896, 392,160, and 392,186 also are referred to.