US2004272A - Production of artificial products - Google Patents

Description

June 11, 1935. H DREYFUS v 2,004,272

\ PRODUCTION OF ARTIFICIAL PRODUCTS Filed July 22, 1951 Patented June 11,1935 i t ENT OFFICE PRonUcrrIoNoF An'rlrrcmr. PRODUCTS I HenryQD reyfus, London, England v Application July 22,1931, serial No. 552,545 1 In Great Britain July30, 1930 '10 Claims. (01. 1 -54) This invention relates to the production of .filaments, yarns, threads, ribbons, films and otherproducts from viscose or other solutions of cellulose or of cellulose derivatives. In' my prior U. S. application S. No. 488,830 filed 15th October, 1930 I have described the production of filaments, threads, ribbons and other productsfrom solutions of viscose'bycoagulating the-viscose in the form of ametallic cellulosexanthate and thereafter treating-the formed products to regenerate the cellulose. The 1 regeneration of the cellulose could, for instance,

be effected by treating the formed products with strong acids, for instance with strong mineral acids, organo mineral acids or acid esters thereof. By this means products were obtainable of fine denier or small cross-section and of high-strength.

I have now found a further means by which products of very fine denier or small cross-sec tion and also of high-strength may be obtained from solutions of viscose and in addition the process of the invention is applicable to the production of filaments or other products from. cu, prammonium solutions of cellulose. or other solutions of cellulose orcellulose derivatives. Ac cording to the present invention the solution of cellulose or of a cellulose derivative is extruded into a medium so that little or no elimination of the solvent takes place from the viscose or other solution or, at least after passage through the medium the viscose or other product is still liquid or substantially liquid.

Preferably the viscose, cuprammonium cellulose or other solution of cellulose or cellulose derivative adapted to yield products of regenerated cellulose is extruded into a liquid which is a' non-solvent for the cellulose or for the cellulose derivative and is a non-solvent for the solvent of the spinning solution, for instance water in the case of viscose. Hydrocarbons or halogenats' the extruded filaments or other products sink or are drawn downwards through the bath of benzene or other light liquid. The specific gravity of the viscose or other spinning solution may it self be adjusted, if desired, as for example by adjustingits concentration or by means of additions made thereto with the object of increasing the specific gravity. As an alternative a liquid which is heavier than theviscose or otherspinning solution may be" used, "and the viscose or other spinning solution extruded vertically upwards or upwards at an angle into the heavy liquid, and the filamentsor other products be-' ing drawn oif or allowedi tdrise through the l If; i i

9 For convenience of starting up it is preferable however not to rely altogetherupon 'diflference in gravityof the spinning solution and the liquid into which it is spun. Startingjup may, forexamp'le, be effected by spinning initially.

into afbathadapted tocoagulate the cellulose solution, and the bath characteristic o'ftheprese ent inVention may be thereafter introduced so that thefilaments or other products are already being drawn from the nozzle before the introduction of the said bath.

The invention also includes a process in which some elimination of the solvent of the spinning solution takes place in the preliminary stage of.

theformation of the products described above. For instance in the case of viscose or other aqueous spinning solutions the liquid may be such'that it dissolves out a proportion of the waterused assolvent in the spinning solution.

Forthis purpose liquids which themselves have V a small solvent power for water may be used, or alternatively the hydrocarbons, halogenated hydrocarbons or. other water repellent liquids referredto above may fb'e mixed with alcohol, 'acetic acid, formic acid, lactic acid or other liquids which are adapted to confer thereon a small solvent power for water, "andwhich are at the same time non-solvents for the cellulose xanthate or other base contained in the spinning solution. The amount of water'thus abstracted from thefilamentsor other products should not however be sufficient to prevent their being liq-' uid orsubstantially liquid on the completion of this preliminary stage of their formation. The length of preliminary bath of hydrocarbon, halogenated hydrocarbon or other suitable liquid which the filaments or other products are formed may vary very widely. It depends to some extent upon the amount of drawdown if any, which is applied and on the viscosityof the spinning solution. In most cases a length up to a 'few inches suflices to produce the advantages of the present invention;

The filaments or other products, which may,

as described above, be substantially of the same ccmposition as that of the original spinning solution or only have comparatively smallamounts of water abstracted therefromso that they are still liquid, may be coagulated by any convenient method. The coagulation may be such as to effect a simultaneous conversion of theviscose, cuprammonium cellulose .orthe like into cellulose, as is the case in'the art as'practised today,

or alternatively the viscose may be coagulated in the form of a metallic or ammonium cellulose xanthate and subsequently treated to regenerate the cellulose. The regeneration of the cellulose, whether carried out simultaneously with or subsequent to coagulation, is preferably effected by means of strong mineral acids or acid esters thereof or by means of sulphonic acids or other organo mineral acids (comparemy, prior U. S. application S. No. 456,872 filed 8th May,

since it presentsadvantages in the manufacture of comparatively large products, such as may be used as artificial horsehair, bristles or the like,

products being producecl'showing high strength as before and also considerable extensibility.

With regard to the details of eifecting the preliminary formation of the filaments in a body of liquidand subsequently coagulating the same I would say that it is convenient to employ the non-solvent liquid contiguous with the coagulating bath proper. Thus for instance benzene or other light hydrocarbon or liquid may be floated on the top of the coagulating bath, the filaments sinking or being drawn through the layer of benzene or like liquid into the coagulating bath wherein they may be ccagulated either in the form of cellulose itself or as xanthate and then carried round suitable guides and finally out of the bath. For instance any ordinary tank or other device customarily employed to contain the coagulating liquid maybe provided: with a partition across the full width of the container but not reachingto the bottom thereof; the container may be partially filled with the coagulating liquid proper atleast as far up as the bottom of the partition and then the benzene or other light liquid may be poured into one side only; of the partition. The spinning nozzle may then be immersed in the benzene or other light liquid, the filaments orbther products. carried down into the coagulati'ng liquid, underneath the partition and finally out of the bath. As an alternative in the case of employing as the special liquid for use according to the present invention a comparatively heavy liquid, such as tetrachlorethane, hexachlorethane or other heavy halogenated hydrocarbon, the container may be partially filled with the heavy liquid and the coagulating bath proper poured in so as to form a layer on the top. In this case the spinning nozzle may be immersed at the bottom of the bath and the filaments or other products drawn up through thetwo layers of liquid.

The coagulatingliquid used according to the present invention may consist, in the case of viscose, of compartively dilute mineral acids, for example sulphuric acid of to or strength, for preference mixed with sodium bisulphate or other salts and/or having additions of glucose or other sugars or like substances, or in the case of cuprammonium solutions of cellulose may consist of relatively dilute caustic soda or other suitable alkaline coagulating liquids. erated may then be treated with a string mineral acid or other agent adapted to exert a solvent, softening or incipient solvent action thereon. Such solvent action may be allowed to develop on the filaments or other products by a concentration of the mineral acid or other reagent employed in the coagulating bath itself.

Preferably, however, the coagulation and reextruded from a jet is is led under thepartition by means of guides? and 8, then round a guide ii to a draw-roller it. From the roller it proceeds to a suitable winding or twisting and winding device, e. g. a bobbin H which may rotate in a washing liquid contained in a vessel 52. For convenience in starting up, the partition l may be made removable, being inserted only after the thread has been led round the thread guides l, 8 and 9 to the feed roller I D. In carrying out the process with such an apparatus spinning is started up with a coagulating liquid in the customary manner, the bundle of filaments being carried round the guides to the roller After spinning has been begun a medium lighter than the coagulating-liquid is run into thecompartinent of the bath containing the spinning nozzle, .until the interfacial surface indicated by line [3 is suitably below the level of the nozzle so that the filaments leave that medium while still in a substantially liquid state. This point in the process is rep resented in the figure by the passage of the filaments through the lighter medium l3 until they reach the coagulant M. V

Referring to Figure 2, a spinning vessel [5 is provided with a spinning nozzle it connected with a candle filter i1 pivoted at N3, the spinning nozzle being adapted. to spin upwardly. The filaments 5 produced are conducted round the feed roller !9, to a thread guide 2%, through a bath 2i containing a softening liquid, and thence round the roller 22 to a bobbin or other suitable winding device 23, the said bobbin being rotated in running water or sprayed with water from a suitable device 2 5. This particular form of apparatus is suitable for carrying out the process inwhich the coagulating liquid 26 is lighter than the medium 27 from which the filaments are removed in substantially liquid form. The latter liquid is run into the spinning bath by means of the tube after spinning has been started up with a normal coagulating bath, forming an interfaoial surface 25 above the spinning nozzle. I

The filaments thus coagulated and regen-' The following examples illustrate the invention, but they are not to be considered as limiting it in any wayr- Example 1 A coagulating vessel is provided with partition extending across the full width thereof, but

neath the partition a thread guide is arranged adapted to lead the filaments from one compartment of the bath to the other compartment.

In one compartment is arranged a spinning nozzle adapted to spin downwards, the height of the spinning nozzle being conveniently 3 or 4 inches above the bottom of the partition. The bath is filled to a point above the spinning nozzle with a 65-80% aqueous solution of sulphuric acid or a 60-70% solution of benzene 'sulphonic acid. Spinning is then started up with a viscose solution in the customary manner, the filaments being carriedround the thread guide and out of the bath through the compartment not containing the spinning nozzle. The thread is carried'roundfa feed roller adapted to exert the required tension and thence to a centrifugal spinning box or a bobbin or other winding or winding and twisting device. Conveniently while being fed into the spinningbox or while being wound on the bobbin the strong acid is removed from thefilaments by winding. A bobbin may, for instance, be rotated in running water. After spinning has begun benzene is run into the compartment of the coagulating bath containing the spinning 'nozzle until its level reaches a point 1 to '2 inches below the spinning nozzle, Spinning is thereafter continued. The speed of the feed'roller may be increased after the introduction of the benzene, so as to obtain filaments of "unusually 'fine denier. W 1

Example 2 A spinning vessel provided with a spinning nozzle adapted to spin upwardly is filled with. an aqueous solution containing 10% of sulphuric acid, 1% of ammonium sulphate, 15% of sodium sulphate and 10% of glucose. Spinning is started up with a viscose solution, preferably obtained from an unmatured alkali cellulose or V H yarns, threads, ribbonsfilms and like extruded from an alkali cellulose which has been matured for a comparatively short time, and the formed filaments are carried round a feed roller and thence into a bath consisting of a 60% aqueous solution of sulphoacetic acid, The yarn is carried out of the coagulating bath and wound on a bobbin rotating in running water or sprayed with water. After starting up, tetrachlorethane is run into the bottom of the spinning bath, for example by means of a suitable tube or pipe reaching to the bottom, until it covers the spinning nozzle to the extent of l to 2 inches. Spinning is thereafter conductedas described in Example 1. r

The term cellulosic solution, as used hereinafter in the claims, is to be understood as meaning solutions of cellulose or of derivatives thereof which are relatively unstable and capable of ready regeneration, erg. viscose and the term does not include solutions of organic esters or ethers of cellulose, which are relatively stable.

What I claim and desire'to secure by Letters- Patent is:-- a

1. Process for the manufacture of filaments,

yarns, threads, ribbons, films and like extruded products from aqueous cellulosic solutions, comprising extruding the said solutions into liquids which are water-repellent, continuously remov- 2. Process for the manufacture of filaments,

yarns, threads, ribbons, films and like extruded products from aqueous cellulosic solutions, comprising extruding the said solutions into a liquid medium comprising hydrocarbons which is a ucts from said medium whilst they are still,

liquid, and thereafter setting the saidproducts.

'4. Process according to claim 1 wherein the cellulosic solutions arewpassed through the medium for a comparatively short distance of the order of 1 to 2 inches.

5. Process for: the manufacture'of filaments, yarns, threads, ribbons, films and like extruded products from solutions of viscose, comprising spinning the said solutions into a. liquid medium which is a non-solvent for the constituents of the solutions and continuously removing the same from said medium while the products are still liquid, and thereafter setting the said filaments and regenerating the cellulosic base thereof by treatment in an acid bath.

6. Process according to claim 5 wherein the acid present in thebath is a body selected from the group consisting of strong mineral acids and acid esters thereof and organo mineral acids.

7. Process according to claim 1 wherein the filaments or other products are drawn down to products. of low denier or small cross-section prior to completion of the setting.

8. Process for the manufacture. of filaments,

products from solutions of viscose, which com prises extruding thesaid solutions into a liquid medium which is a non-solvent for the constituents of the solutions and continuously removing. the products from said medium while they are still liquid, and thereafter setting'the products and regenerating the cellulosic base thereof, the formedproducts beingsubjected: to a stretching operation prior to completion ofthe setting,

9. Process for the manufacture of filaments,

. yarns, threads, ribbons, films and like extruded products from aqueous while they are still liquid and thereafter setting the products, the formed products being sub- ,mitted to a stretching operation prior to completion of the setting.

10. Process for the manufacture of filaments, yarns, threads, ribbons, films and like extruded products from solutions of viscose, which comprises extruding the said solutions into a liquid medium which is a non-solvent for the constitu cuts of the solutions and continuously removing the products from said medium while they are still liquid, and thereaftersetting the products and regenerating the cellulosic base thereof, the

formed products being submitted to a stretching operation prior to regeneration.

. HENRY DREYFUS.

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