Patent GB-346793-A (GB)
Title: Improvements in the manufacture of artificial filaments, threads, ribbons, films and the like and in products resulting therefrom
IPC: D01F2/28
Filed: 1929-10-17
Abstract: Cellulose esters and ethers; unspecified cellulose solutions.-A reduced or modified lustre is obtained in artificial filaments, threads, ribbons, films, &c., of cellulose or cellulose derivatives by the distribution in the basic material of fine particles of a natural or synthetic resin which does not melt below about 200 DEG C. Preferably, the resin is insoluble, or substantially so, in the basic material; if soluble, it is used in such quantity that some remains undissolved.  It is also, preferably, insoluble in common organic solvents.  Resins, such as Zanzibar copal or synthetic resins, having melting-points above 250 DEG  or above 290 DEG  C. are particularly suitable.  If synthetic, they may be of the phenol-aldehyde, formaldehyde-urea, formaldehyde-thiourea, or polyhydric alcohol-poly-basic acid types.  Softer resins, such as white Angola, hard Manila, Congo, or Sierra Leone copals are less advantageous.  If the resin has a yellowish tint, this may be counteracted by the incorporation of a substance of complementary colour in the spinning solution or in the filaments &c. after manufacture.  Pigments, particularly white ones such as titanium oxide, zinc oxide, barium sulphate, or silica may also be added; they may be intimately incorporated in the resins, say by introducing or precipitating the pigment in the reaction mixture serving for the preparation of the synthetic resin.  The proportion of resin preferably does not exceed 20 per cent of the weight of the cellulose derivative and proportions of 1/2 to 5 per cent are most suitable. Smaller quantities of hard than of softer resins are required.  The average size of the resin particles should not exceed 0,006 mm., and preferably is not greater than 0,003 mm.; for instance, it may be 0,001-0,005 mm.  Before incorporation, the particles may be graded, say by a cyclone separator.  The resin may be ground either per se or in the presence of the basic substance or of liquids, for instance water, a solvent to be used in the spinning solution, or this solution itself.  Dispersators and protective colloids, e.g. turkey red oil, or oils such as oleic acid, olive oil, or linseed oil may be used to improve dispersion.  Soluble resins may be dissolved in a mixed solvent suitable also for dissolving the cellulose derivative, or in hydrocarbons, esters, &c., which are then added to the spinning solution.  Wet or dry spinning may be employed.  The cellulose derivative may be viscose, cellulose acetate, formate, propionate, or butyrate, or methyl, ethyl, or benzyl cellulose.  In making the solutions, high-boiling solvents or plasticizers should not be used in such proportions as to render the resin soluble in the basic substance. The filaments of modified lustre produced may be associated with products of normal lustre, or with other fibres such as cotton or wool.  Monofil threads may be made entirely or partly from the filaments of modified lustre by the processes described in Specifications 326,461 or 326,462, [both in Class 2 (ii), Cellulose &c.].  The delustring effects may be enhanced by applying the process described in Specifications 328,247, 333,504, 334,195, [all in Class 2 (ii), Cellulose &c.], or 346,678.