US1865358A - Manufacture of artificial silk, artificial horsehair and like products - Google Patents

Description

.Bll

Patented June 28, .1932

PATENT; OFF CE HENRY D BEYFUS, OF LONDON, ENGLAND murac'ruan or an-nrrcmr. SILK, anrrrrcm HOBSEHAIR AND 1.11m rnonuc'rs Iio Drawing. Original applloatlon flled June 28,1923, Serial No. 648,350, and in Great Britain August 11, 1922. Divided and this application filed April 5, 1928., Serial No. 267,808.

This application is a divisional application from my U. S. application Serial No. 648,350 which eventuated. into Patent No.

1,688,531, granted October 23, 1928.

This invention relates to the manufacture of artificial silk, artificial horsehair or like threads or filaments from, solutions of cellulose acetate in particular, but applies also to their production from other solutions of esters of cellulose or of ethers of cellulose such for example as ethyl-, methylor benzyl cellulose, or from mixtures of any of such cellulose derivatives, all of which cellulose derivatives are hereinafter in the claims referred to as organic substitution derivatives of cellulose. The invention solely concerns processes in which the artificial threads or filaments are produced by the dry or evaporative method of formation, that is to say by so extruding a solution of the cellulose derivative or derivatives inror containing a volatile or vaporizable solvent or solvents, through jets or spinnerets into a heated or other atmosphere in which the filaments or threads solidify by evaporation of solvent. In particular the invention relates to the manufacture of threads, filaments or the like from cellulose acetate solutions by dry or evaporative spinning;

Inthe manufacture of artificial threads or filaments from solutions of cellulose acetate or other cellulose esters or ethers such as re-\ ferred to'by the evaporative method it is usual to employ spinning solutions of rela? tively low concentration, containing not more than about 16% of the cellulose derivative or derivatives in the solvent 0 solvents used. It has now been found that y employing for the d or evaporative spinning solu or the like from cellulose acetate solutions, for

tions of su stantially higher concentrations, containing more than 20% of the cellulose derivative or derivatives, and especially in the case of cellulose acetate solutions, artificial threads or filaments of improved quality can be obtained, possessingrg'reatermechanical strength and rounder section, 'and showin much less tendency to crinkle or turn wooll in appearance under the action of very liot or boiling water, than is the case with dry-spun artificial threads or filaments, made from the less concentrated solutions previously employed. It is moreover found that, especially in the case of cel lulose acetate, the employment of solutions of high concentrations as referred to has the further advantage of obviating or greatly reducing what may be called glitter of the threads, filaments or the like, that is to say, a glittering or scintillating efi'ect which is sometimes possessed by filaments or threads formed by dry 'or evaporative spinning from solutions of the relatively low concentration usually employed, and possibly due to the sectional configuration of the filaments resulting from the spinning of such solutions, by the dry or evaporative method of formation. This glitter effect or glitter-producing structure of the filaments or the like can in some cases be adisadvantage. For example, in cases where goods in hank, .79 woven or knitted fabric or other form, made with threads showing such glitter effect are dyed in black or dark colours, it is sometimes found that the dyed goods give an impression as if the artificial silk is dyed only partially or not deep enough or that they have a worn appearance, this being more especially seen in fabrics. Each per cent increase in the, concentration of the solutions of the cellulose acetate or other cellulose derivatives over and above 20% is accompanied by a great increase in the viscosity of thespinning solutions and in the strengthof the filaments or threads obtained. Moreover, at a concentration of about 21%, glitterless filaments are obtainable. At a concentration of 22% theroundness and strength of the filaments is still more marked.

By forming the dry spun threads, filaments example, of high concentrations such as before referred to, namely 21 or 22 to 25%, it will be seen that the filaments or threads are stronger than those made from solutions of the usual low concentrations, not so liable to crinkle or. turn woolly as a result of the action of hot water, and moreover that glitter or glitter-producing structure is obviated or greatly reduced, with its tendenc to give on dyed goods, and especially goods d yed in black or dark colours, the appearance before referred to.

The following are two examples of spinning solutions which may be employed according to the invention, it being understood that these are given only by way of illustration and that other solvents or solvent mixtures may be employed and that the concentrations can be varied without departing from the invention.

- E wample' 1 Cellulose acetate is dissolved inacetone in quantity to give a solution. containing between 21 and 25% cellulose acetate.

Ewample 2- Cellulose acetate is dissolved in acetone containing about 5 to 10% of alcohol and about 5% of water, in a quantity to give a solution containing between 22 and 25% of cellulose acetate in the solvent mixture.

The solutions are dry spun inthe known 'way by extrusion through spinnerets into a heated atmosphere;

While my invention relates especially to the manufacture of artificial threads, filaments or the like from cellulose acetate solutions by the dry or evaporative method it is also applicable to their production by the dry or evaporative method from solutions of other cellulose esters or ethers or mixtures of cellulose esters or/and ethers. v

What I claim and desire to secure by Let ters Patent is 1. Process for the manufacture of artificial filaments and threads, characterized in that the same are dry spun from con'centratedsolutions of organic substitution derivatives of cellulose containing at least 21 and less than 25% of the cellulose derivative.

2. Process for the manufacture of artificial filaments and threads, characterized in that the same are dry spunfrom concentrated solution of organic substitution derivatives of cellulose containing at least 22 and less than 25% of-the cellulose derivative.

3. Process for the manufacture of artificial filaments and threads, characterized in that same are dry spun from concentrated solutions of cellulose acetate containing at least 21 and less than 25% of cellulose acetate.

4. Process for the manufacture of artificial filaments and threads, characterized in that the same are dry spun from concentrated solutions .of cellulose acetate containing at least 22 and less than 25% of cellulose acetate.

, In testimony whereof I have scribed my name.

HENRY DREYFUS.

hereunto sub-