US1614431A - Manufacture of filaments and films from viscose - Google Patents

Description

Patented Jan. 11,1927.

UNITED STATES WILLIAM MENDEL, F

PATENT OFFICE.

MANUFACTURE OF FILAMENTS AND FILMS FBOM'ITISCOSE.

No Drawing. Application filed May 9,

, viscose (cellulose sulphocarbonate) through orifices into baths containing chemicals which coagulate the viscose as aasemi-solid impure cellulose hydrate of sufficient strength to be handled, and an object and'effect of this invention is to eliminate the impurities from such coagulated cellulose hydrate and thus improve the luster, strength and elasticity of the finished filaments.

Such coagulating or' precipitating baths heretofore employed are of various kinds.

For instance, because oftheir prompt actionand relatively low cost strong acid baths, such as an aqueous solution containing eight per cent of sulphuric acid or five per cent of hydrochloric acid are commonly used for individually thin filaments such as are used in the production of artificial silk. With baths of that character, substantially all of the sulphur primarily chemically combined with the cellulose in viscose is released as free sulphur but is occluded in the mass of. cellulose hydrate and impairs every desirable quality of the finished product; it being impossible to more than partially remove sulphur and its derivatives from the celllulose hydrate by the ordinary processes. Consequently, filaments thus formed have a dull yellow white surface and are comparatively Weak and brittle. Organic acids and inphur and its derivatives, and with the effectthat the effects of free sulphur are somewhat less apparent, but the increased cost of such additional chemicals and treatment is not economical because processes for cleansing the filaments are yet required, as in the caseof the stronger acids. Y

" .duced in such bathsin I have, discovered that if any. suitable coagulating bath is made to include the PO,-

1011, filaments of cellulose hydrate formed .in such bath are practically sel -cleansing because the sulphur derivartives are thereb the disadvantages of thelusual presence of ble sulphidesyare thus automatically eliminated. I Such ions may be added to orproany convenient form or manner. However, tri-sodium phosphate with 2. The

1925. Serial No. 29,9828.

(Na,,PO,) is a cheap vehicle for such ions and may e used in aqueous solution.

Although an aqueous solution of either mono-sodium phosphate or di-sodium phosphate'or said tri-sodium phosphate alone W111 efl'ect coagulation of viscose projected therein, particularly if the viscose is of low alkalin ty and such solution be hot; even a small percentage, approximating a'. mere trace of the 1on PO, is suflicient in association or conjunction with any other suitable coagulating material. For instance, an aqueous bath containing ten -per cent of sulphuric acid (H', S O,) and containing ten per cent of sodlum sulphate (Na,SO,) is an ordinary coagulating bath which is subject to the objections' aforesaid, but I find that the addition of even a fraction of one per cent of P0 to such bath has the advantageous results above contemplated in the elimination of or prevention of formation of, insoluble sulphur derivatives in or upon the cellulose products.

Filaments thus coagulatedin accordance my .invention mayv require no subsequent treatment other than rinsing with ,water and, when so treated and dried, preferably under tension, have unusually high luster, strength and elasticity.

Therefore I do not desire to limit myself to. the precise details of construction, arrangement or procedure herein set forth, as it is obvious that various modifications may e made therein without departing from the essential features of my invention, as de-.

fined in the appended claims.

I claim:

1. The methodof manufacturing articles from viscose which consists in coagulating viscose in an aqueous solution in which trisodium phosphate, (N a PO,) has been dissolved with another solute ing such coagulation.

method of manufacturing articles capable of affectfrom viscosewhich consists in coagulating 100 viscose in an aqueous solution in which trisodium phosphate -(Na PO has been disy .-solved ,-with an acid salt solute, capable of rendered soluble in the bath; so that all of Y 50 sulphur and its derivatives, such as insoluaffecting such coagulation. 3; The method of manufacturing articles from viscose which consists in coagulating viscosein an aqueous-solution in which trisodium phosphate (Na POQ has been dissolve'd,with an acid solute capable of affecting such coagulation.

4. In the manufacture of cellulose articles from viscose (sulphocarbonate), the introduction of the latter into an aqueous solution resultant from mixture of Water with an inorganic acid and tri-sodium phosphate.

, 5. In the manufacture of cellulose articles from viscose (sulphocarbonate), the introduction of the latter into an aqueous solution resultant from mixture of Water with a strong mineral acid and Na PO 6. The method of manufacturing articles from viscose Which consists in coagulatingviscose in an aqueous solution comprising Na PO 7. The method of forming from cellulose sulphocarbonate a semi-solid composition which is principally cellulose hydrate, and free from deleterious sulphur compounds; which consists in coagulating liquid sulphocarbonate in an aqueous solution including an efiicient acid coagulating agent, and P0 ions in such relation With sodium phosphate as to extract such compounds from the sulphocarbon'ate into said aqueous solution and prevent recipitation of such com ounds, by holding them in said solution, in epend-.

ently of said cellulose hydrate.

' 8. The method of preventing formation of insoluble sulphur compounds during the coagulation of cellulose sulphocarbonate; which consists in precipitating liquid cellulose sulphocarbonate as a scmi-solid'composition which is principally cellulose hydrate, and free from deleterious sulphur compounds, in an aqueous solution including an efiicient coagulating agent, and P0 ions in such relation with a sodium derivative as to extract such sulphur compounds from the sulphocarbonatae into said aqueous solution and prevent precipitation of such com pounds by holding them in said solution,

independently of said precipitated cellulose hydrate.

In testimony whereof, I have hereunto signed my name at Philadelphia, Pennsylvania, this eighth day of May, 1925.

WILLIAM MENDEL.