US2021861A - Regenerated artificial structure and process of making same - Google Patents

Description

Patented Nov. 19, 1935 UNITED STATES REGENERATED ARTIFICIAL STRUCTURE AND PROCESS OF MAKING SAME Leon Llllenfcld, Vienna, Austria No Drawing. Application March 13, 1930, Serial No. 435,648. In Austria March 16, 1929 46 Claims.

The present invention relates to the production of artificial structures (including artificial threads, films, and coated products, etc.) from hydroxy-alkyl derivatives (ethers) of cellulose, which products will have satisfactory dry and wet tenacity, at least a fair extensibility and-a good appearance, all as will be hereinafter set forth and illustrated in certain examples and as claimed.

In carrying out the process of the present invention solutions of hydroxy-alkyl cellulosexanthates can be easily converted into artificial structures by-giving their solutions the shape of the desired artificial structure, for example thread, and acting upon the shaped solution with a coagulating agent. This agent may or may not also have a plasticizing action, or if desired the shape solution can be acted upon first with a coagulating agent and thereafter the freshly coagulated artificial structure can be acted upon with a plasticizing agent. The-plasticizing treatment is in some cases usefuLbut the invention in its broader aspect is not restricted to this step.

The alkaline solutions of xanthates of such hydroxy-alkylcellulose ethers as are prepared by reacting upon cellulose, in the presence, of an alkali, with hydroxy-alkylating agents (e. g. halogenhydrins) can be converted into artificial structures (e. g. threads) by treating the said xanthate solutions, while having the shape of the desired artificial structures, with an acid solution, e. g. the said xanthate solutions can be spun, through a spinnerette, into a setting bath known in the viscose industry, whether or not said bath also has a plasticizing action on the freshly coagulated artificial thread. Accordingly the plasticizing baths referred'to in the preceding paragraph, while often advantageous, are

not necessary in the. process.

The artificial structures produced according to the present invention have a satisfactory and, in some instances, even excellent tenacity in the dry and wet state and a pliability, extensibility and elasticity sufllcient for all practical purposes.

This .result of the present invention is rather surprising, considering that it is to be assumed, that, on contacting a shaped solution of a hydroxy-alkyl cellulose xanthate, for example a thread-like stream (as coming through the openings in a spinnerette) with a precipitating agent, for example an acid, the hydroxy-alkyl derivative of cellulose to which, in its xanthate, the CSS-group has been attached, is regenerated.

In other words: Although the artificial materials of thepresent invention probably consist of, or

contain, the very same hydroxy-alkyl ethers of cellulose which are the basic constituents of the artificial materials made heretofore from hydroxy-alkyl ethers of cellulose, with -regard to their properties, the shaped artificial structures 5 made by the present process are superior to any 5 artificial structures heretofore produced from hydroxy-alkyl cellulose ethers.

The present invention consists in making artificial threads or other products by bringing into 10 the appropriate form or shape a solution of a cellulose compound which contains at least one CSS-group and at least one radical of a dior poly-hydroxylic alcohol and which cellulose compound is produced by converting the whole or 15; a part of th'cellulo'se employed into a hydroxy- I alkyl ether of cellulose and thereafter treating the product thus obtained in the presence of an alkali with carbon bisulphide, and then acting uponv this shaped solution with a coagulating 20, agent which may also have a plasticizing effeet on the material during, or immediately after, its coagulation, or acting upon the shaped solution first with a coagulating agent and thereafter if desired, acting with an agent which has 5; a plasticizing eifect on the freshly coagulated material. The hydroxy-alkyl derivatives of cellulose which are intended to be converted into their xanthates may be produced according to the processes described in my concurrently filed ap- 0 plication Ser. No. 435,647 (now U. S. Patent 1,858,097) or my U. S. Patent 1,722,927.

Stated otherwise, the invention of the present case comprises bringing a solution of a xanthate of a hydroxy-alkyl derivative of cellulose or of 5 a near conversion product of cellulose (made for instance by the process set forth in my U. S. Patent 1,858,097, e. g. by xanthating the hydroxyalkyl derivatives of cellulose, which hydroxyalkyl derivatives are at least partially soluble in 40 caustic alkali solution and which may be produced by the process set forth in my Patent 1,722,927, i. e. by a process in which cellulose or a near conversion product is treated with a hydroxyalkylating agent in the presence of an alkali) into the shape of the desired artificial structure and contacting the same with a coagulating agent. The coagulating agent may be any solution known as a setting bath for viscose, (such for example as dilute mineral acids, strong mineral acids, acid salts, mixtures of acid solutions with salts, etc.) The hydroxy-alkyl derivatives of cellulose, before the 'xanthating step may be soluble or insoluble in alkaline solutions (e. g. in caustic alkali solutions), but the xanthated products will be soluble in such alkaline solutions.

The hydroxy-alkyl cellulose xanthates may be worked up into artificial structures, for instance threads, alone or in conjunction with other colloids, such as cellulose xanthate, by mixing a solution of a hydroxy-alkyl cellulose xanthate with viscose orby dissolving cellulose xanthate (sulphidized alkali cellulose) in a solution of a hydroxy-alkyl cellulose xanthate or by dissolving a hydroxy-alkyl cellulose xanthate in viscose, or by conducting the present process so that the carbon bisulphide is allowed to act in presence of caustic alkali upon a mixture of cellulose and a hydroxyalkyl derivative of cellulose, for example by treating alkali cellulose with a halohydrine under such conditions that only part of the alkali cellulose is converted into a hydroxy-alkyl ether of cellulose and thereafter by the action of carbon bisulphide converting the reaction mass into a mixture of a hydroxy-alkyl cellulose xanthate with cellulose xanthate. Also other alkali-soluble derivatives of cellulose or alkali-soluble cellulose hydrates, 01'. proteins, or gelatine, or the like, may be used as admixtures to the hydroxy-alkyl cellulose xanthates or their solutions.

Any suitable softening agents, such as glycerine or a glycol or a sugar, such as glucose, or a soap or Turkey-red oil, or a drying or non-drying oil, or any known elasticizing agents, for example a halogen derivative of a dior poly-hydroxylic alcohol, particularly a halohydrine, such as a dichlorohydrine or a monochlorohydrine for example ethylene chlorohydrine may be added to the solutions of the hydroxy-alkyl cellulose xanthates, or of their mixtures with cellulose xanthate.

As stated above, according to the present invention, the artificial structures, for example threads, are produced by giving a solution or paste of a hydroxy-alkyl cellulose xanthate the appropriate shape or form, and acting upon the shaped solution with a coagulating agent which may also have a plasticlzing effect on the material during, or immediately after, its coagulation, or acting upon the shaped solution first with a coagulating agent and thereafter, if desired, with an agent which has a plasticlzing effect on the freshly coagulated material.

Particularly useful plasticlzing agents, which in the former modification of the present process act also as coagulating agents, are liquids which have a high content of strong mineral acid, particularly such baths as contain not less than per cent. of sulphuric acid monohydrate or an equivalent quantity of another mineral acid. But also other plasticizing .agents can be employed, for example baths containing a fair amount of a zinc halide alone or mixed with an acid.

But within the broad scope of the invention, any chemical coagulating orprecipitating agent or mixture of precipitating agents or mixture of precipitating agents with other inorganic or organic substances, known as setting baths in the viscose art may be usedini, the present process. Excellent results, particularly with regard to tensile strength, are obtained when the freshly coagulated material is exposed to the action of 'a plasticizing agent (but this step is optional).

This purpose can be accomplished either by using as the setting bath a liquid which has a coagulating effect on the shaped solutions of the hydroxy-alkyl cellulose xanthates and a plasticizing effect on the coagulated solution (for acid), or by employing as the setting bath a. liquid that has only a coagulating effect on the formed solutions of hydroxy-alkyl cellulose xanthates (for example, any coagulating but not plasticlzing bath known in the viscose art) and subsequently, (if desired) acting upon the freshly 10 the shaped hydroxy-alkyl cellulose xanthate sol ution.

The methods for the bringing of the solutions of the hydroxy-alkyl cellulose xanthates into the form of artificial structures, for example threads,

for coagulating, washing and finishing, desulphurizing, bleaching, etc., are similar to the methods of forming artificial structures, e. g; threads, in the viscose art in general and the artificial silk art in particular, and the special methods of producing artificial structures, for 30.

example threads by means of coagulating agents that have also a plasticlzing effect on the freshly coagulated artificial structures have become known in the art under the name of Lilienfeldsilk produced by the so-called Lilienfeld processes 35 (see my U. 8. Patents 1,683,199 and 1,683,200) and therefore it seems superfluous here to enter into full particulars of these procedures.

If desired, the extensibility of the artificialstructures, particularly threads, produced ac- 4a.-

cording to the present process may be still more increased by treating them with suitable shrinking agents, i. e. such shrinking agents as have no dissolving effect on the thread, for example with some of the shrinking agents mentioned in my U. S. patent applications, Ser. No. 308,589;

186,575; 367,154 and 367,150, now Patents 1,989,098 to 1,989,101 inclusive, and 2,001,621.

Thus the threads can be subjected to the'action of any mercerizing agent (e. g. NaOH solution preferably of 15-18% strength, or stronger, or NaaS solution of 15% or stronger) preferably applied hot, while not under such a degree of tension as to prevent shrinkage of the thread, and

thereafter washing, treating with a dilute acid solution and again washing. The treatment with the mercerizing solution may be continued for one to five minutes, more or less. If sodium sulphide solution is used as the shrinking agent, it

also will act to desulphurize the artificial threads. Theyals'o may be refined or decolorized by treating them with a warm .or hot solution containing 10% of alkali sulphide (calculated as N8:S.9H2O) or with a warm or hot alkali hydrosulphide solution of equivalent strength. This latter treatment is claimed in a copending case, Patent No. 2,004,875.

It is impossible to indicate every condition for success in every particular case and it is to be understood that preliminary experiment cannot be avoided to find what are the best conditions, when using a particular cellulose, a particular form of hydroxy-alkyl cellulose xanthate and particular details of the shaping and coagulating for example, spinning operation.

accuser The following examples of operation serve as a practical illustration of the present invention, which, however, is in no way limited to the examples; the parts are by weight:

Example 1 Any one of the crude hydroxy-alkyl cellulose xanthates obtained in Examples 1 or 4 or 6 or 7 (the latter two as far as they relate to 100 parts of a-monochlorohydrine or ethylene chlorohydrine) or Examples 9 or 12 or 15 or 17, of my concurrently filed application 435,647, (now Patent 1,858,097) is dissolved in such a quantity of water and caustitc soda as to yield a solution containing about 6.5 to 7 per cent. of the parent hydroxy-alkyl cellulose and 8 per cent. of NaOH. (In case of Example 17 in which the cellulose dihydroxy-propyl ether is xanthated in the dissolved state, the proportions of NaOH to water and cellulose desired in the spinning solution are arranged before xanthating takes place.) The solution is now filtered three times through cotton and after it has attained a total age of 96 to 100 hours (in the case of Examples 1 or 6 or 7 or 9 or 12) or of 48 hours (in the case of Example 17). The solution is spun as follows:

(a) The spinning solution is pressed at a. speed of 3.3 ccm. per minute through a platinum nozzle (having 54 holes of 0.1 mm. diameter) into a bath containing 65 to 73 per cent of H2804 and having a temperature of 16 C. and the length of immersion of the threads in the sulphuric acid being about 20 cm.; then the threads are allowed to pass through the air for 120 cm. and wound on a spool revolving at a speed which produces a speed of spinning of about 18 111. per minute. In the air passage, 3 glass rollers are arranged angularly to one another, over which rollers the thread runs, thus applying an additional stretch or tension to the threads. The lower part of the spool revolves in water, so that the sulphuric acid is removed or is considerably diluted as soon as the thread arrives at the spool. The threads are then washed, purified, twisted and finished in the usual manner. 4

The thread obtained in this manner consists of individual filaments of about 2 to 2.5 deniers each.

(b) The mode of operation is the same as in Example (a) but with the diiference that the spinning bath contains 55 to 60 per cent of H2304- (c) The mode of operation is the same as in (a) or (b), but with the variation that the temperature of the spinning bath is 0 C.

(d) The same mode of operation as in (a) or (0). but with the difference that only 1.6 ccm. of the spinning solution is discharged per minute that the nozzles have 100 perforations of 0.08 mm. diameter, and that the spinning bath contains 61' to 70 per cent of H2804.

The titre of the individual threads is about 0.6 to 0.7 denier.

(e) The same mode of operation as in (d), but with the difference that the spinning bath contains 55 per cent of H2804.

(f) The same mode of operation as .in (a), or

(b), or (c), but with the difference that 3 ccm. of'

the spinning solution are discharged per minute and that the speed of spinning is 30 m. per minute.

The titre of the single filament is about 0.6 to 0.9 denier.

(g) The same mode of operation as in (a) or (0), but with the difference that 6.6 ccm. of the spinning solution is discharged per minute, that a the nozzles have 100 perforationsof 0.08 mm.

diameter, that the speed of spinning is m. per minute and that the setting bath contains 64 5 per cent. of H1804.

The titre of the individual threads is about 1.2 to 1.4 denier.

(h) The same mode of operation as in (a), but with the difference that the spinning bath o contains 60 per cent. of H2804.

(i) The same mode of operation as in (d) but with the difference that 3 ccm. of the spinning solution is discharged per minute, that the nozzles have 24 perforations of 0.1 mm. diameter, 15 that the setting bath contains 61 to 70 per cent. of H2804 and has a temperature of 0 C., and that the length of immersion of the thread in the setting bath is 80 cm.

The titre ofthe individual threads is about 4.5 20 to. 5 denier.

(k) The same mode of operation as in (i) but with the difference that the spinning bath contains 55 per cent of H2804.

(l) The same mode of 'operation as in (g) or 25. (h) but with the difierence that the spinning solution is discharged at a speed of 14 ccm. per minute, that the speed of spinning is about 100 to 120 111. per minute, that the thread is not subjected to additional stretch, and that the length 3 1 of immersion is 80 to 100 cm.

The titre of the silk is about 0.9 to 1 denier per individual filament.

Example 2 35 Any one of the crude hydroxy-alkyl cellulose xanthates obtained in Examples 2 or 10 or 11 of my Patent No. 1,858,097 is dissolved in such a quantity of water and caustic soda as to yield a solution containing about 6.5 to 7 per cent of parent hydroxy-alkyl cellulose and 8 per cent. of NaOH. The solution is now filtered three times through cotton and after it has attained a total age of 96 to 100 hours, the solution is spun as in the preceding example.

The concentrations of the setting baths are as follows:

In spinning method (a) and (c): 55 to 65 pe cent. of H2804.

m spinning method (b) per cent. of H2504.

Inspinning method (e): 50 per cent. of H2804.

In spinning method (f): 58 to 60 per cent. of H2504.

In spinning method (g): H2804.

In spinning method (1): to 64 per cent. of H:SO4.

per cent 1 55,

Example 3 Mode of procedure as in Example 1 or 2, but with the difference that, instead of the hydroxyalkyl cellulose xanthate solutions used therein, the hydroxy-ethyl cellulose xanthate solution obtained according to Example 20 of my U. 8. pato5 ent 1,858,097, may be used. This solution contains about 6.5 to 7 per cent of the hydroxy-ethyl cellulose and about 8 per cent. of NaOH. The solution is now filtered three times through cotton and after it has attained a total age of 96 to hours it is spun as in the preceding example.

The concentrations of the setting baths are as follows:

In spinning method (a) and (c): 60 to 62 per cent of H2804. Y 75.

-In spinning method (1)) 55 per cent of H1804. In spinning method (d) 58 to 61 per cent of In spinning method (e) 55 per cent oi. H2804.

"In spinning method (I): 58 to 61 per cent of In spinning method (9):

, In spinning method (I):

58 to 62 per cent of 50 to 55 per cent of Example 4 The solution of the 1:2-dihydroxy-propyl cellulose xanthate obtained as described in Example 18 or 19 of my U. S. Patent 1,858,097 or the solution of the h'ydroxy-ethyl cellulose xanthate obtained as described in Example 21 of my U. S. Patent 1,858,097 and in either case containing 6.5 to '7 per cent of the respective hydrbxy-alkyl cellulose and 8 per cent of NaOH is now filtered three times through cotton and after it has attained a total age of 48 hours, spun as in the pre- In spinning method (I): 40 to 46 per cent H2804.

Example 5 The process is conducted as in any one of the preceding examples, but with the difierence that the. respective hydroxy-alkyl cellulose xanthate is dissolved in such an amount of water and caustic soda that the solution contains 7 per cent of the parent hydroxy-alkyl cellulose and 5 per cent of NaOH.

Example 6 The process is conducted as in any one of the preceding examples but with the difference that a bath containing in each liter, 160 grams of H2504 and 320 grams of Na2SO4 is used as the coagulating or setting bath at about 45 C.

Example 7 The process is conducted as in any one of the preceding examples, but with the'difi'erence that before entering the setting bath the thread-like stream is conducted through one of the following baths.

1) a solution of ammonium sulphate of 25 to 30 per cent strength, or n (2) a bath consisting of 500 parts of sodium bisulphate, 76 parts of sulphuric acid of 66 B.

" and 587 parts of water, which bath may be kept at room temperature or at a raised temperature, for instance 50 (3., or

(3) a bath consisting of 982 parts of water, 180 parts of sodium sulphate, 60 parts of ammonium sulphate, parts of zinc sulphate, 135 parts of glucose, and 128 parts of sulphuric acid of 66 B.

, Example 8 The process is conducted as in any one of the preceding examples, but with the diflerence that the hydroxy-alkyl cellulose xanthate is dissolved in so much water and caustic alkali as to yield a solution containing about 3 per cent of parent hydroxy-alkyl cellulose and 5 per cent of NaOH.

For the carrying out of this example it is recommended to start with a cellulose of high viscosity (determined by the customary methods).

Example 9 The process is conducted as in any one of the preceding examples, but with the exception that a sulphuric acid of 10 per cent strength is used as the spinning bath: the temperature'of this bath being 16 C. or 4 C.

Example 10 The process is conducted as in Examples 1 to 7, but with the diflference that the alkali cellulose is allowed to mature for 48 hours at'15 to 20 C. 20

. Example 11 Mode of procedure as in any one of' the preceding examples, but with the difference that to the spinning solution 10 to 30 parts of'a-dichlorohydrine or a-monochlorohydrine or ethylene chlorohydrine to 100 parts of the hydroxy-- alkyl cellulose xanthate contained therein, are added after the dissolving step.

In those of the foregoing examples, in which strong acids are used, the action of the acid may be interrupted also by subjecting the threads leaving the bath consisting of, or containing strong acids, to a low temperature, for instance -5 to 15 C. before it is washed, which, for instance may be done by collecting it one. hollow spool containing a cooling agent, for instance solid carbonic acid, or a freezing mixture, or ice. The manufacture of staple fibre will be entirely clear from the foregoing examples.

After the threads have been washed they may be heated or steamed at high temperatures (for instance l00-ll0 C.) before or after the drying process.

Bleaching of the threads may be conducted in the known manner.

The threads may be desulphurized for instance by treating them with a hot or warm solution of alkali metal sulphide, containing at least 5% of alkali metal sulphide (calculated as NazSBHzO) for example by treating them with a solution of Na=S.9H:O of 10 per cent strength for 5 to 60 minutes or with a solution of NazSBHzO of 30 per cent strength for about 5 to 10 minutes at 100 C.

Example 12 A xanthate solution, produced in the manner described in anyone of the foregoing examples is introduced in the known manner into. one of the precipitating liquids mentioned in one of the foregoing examples, through a suitable hopper or slit, and the coagulated film band, after having been run through this bath, is washed in the known manner and dried.

Example 13 A cotton material is impregnated or filled or coated, one or several times in a suitable machine for instance a padding machine or a back filling machine, or a spreading machine, with a xanthate solution produced in the manner described in one of the foregoing examples to which solution a filling material, such as talc or china clay or zinc white for instance 100 to 200 per cent. calculated on the weight of the hydroxy-alkyl cellulose), or a dyestufl or a pigment, such as mica, or lampblack, may be added and without being dried, if necessary in a state of tension, is passed through a bath having the composition of one of the coagulating baths mentioned in the foregoing examples. The dressed or coated fabric isthen washed and dried.

In determining whether or not the alkali cellu-.

' 7 Sodium hydroxy-cthyl mlluloee (Cosmos-10in) ONa Sodium 1:2 dihydmxy-mpyl cellulose and artificialthreads in particular, taking account of the fact that this viscosity will also depend on the kind of cellulose used as starting material. If it is desired to give the hydroxy- 'allnrl cellulose xanthate solution a definite viscoslty then the alkali cellulose produced from the kind of cellulose used as parent material, is subjected to a maturing process, if without maturing this kind of cellulose yields a higher viscosity than that desired. If, however, it exhibits from the first (that is without maturing) the desired degree of viscosity, then maturing is unnecessary. Now as viscosities of the different kinds of cellulose on the market (linters and woodpulp) differ very much from one another, the question of maturing depends in most cases on the one handon the viscosity desired ofthe solution intended for the manufacture of artiflcial material, and on the other hand on the viscosity of the kind of cellulose being worked.

Without restricting the present invention to any lower or upper limits of tenacities or extensibility, it may be mentioned by way of example that it is possible to produce, by the present process, artificial threads, when using coagulating baths that exert no plasticizing action (or substantially no plasticizing action) on the freshly coagulated material, which products have a dry tenacity exceeding 2 grams and in some cases at least 2.5 and even 3 grams per denier or even more, and which, without being subjected to any special after-treatment, have an extensibility of at least 12 and in many cases 16 to 18 and even 20 to 24 per cent. and, when plasticizing baths are used, a dry tenacity of at least 2 grams per denier and even 3 to 4 grams per denier or more, and which have a good extensibility of about 7 to and in some cases even 10 to Whether or not the coagulating bath has a plasticizing action, the wet tenacity of the thread is substantially over 1 gram per denier.

I have referred above to certain matter discussed in detail in my concurrent application 435,647 new Patent No. 1,858,097, which case relates to technically valuable cellulose compounds obtained by acting upon hydroxy-alkyl derivatives of cellulose or of its near conversion products with carbon bisulphide in presence of a basic substance, particularly caustic, alkali.

\ According to their mode of formation, chemical viour and results ofanalysis, the said cellulose compounds, in their free state, are believed to be hydroxy-alkyl-cellulose xanthlc acids (dithiocarbomclhydroxy-alkyl cellulose esters) and in the form of their salts, hydroxy-alkyl cellulose xanthates (salts of dithiocarbonic-hydroxy-alkyl cellulose esters).

The reaction leading to the formation of the said cellulose compounds may (I believe) be represented for the simplest types by the following equations in which, as examples, are taken. the hydroxy-ethyl cellulose and the 1:2 dihydroxypropyl cellulose.

1:2 dlhydroxypropyl cellulose xanthate The present specification (435,648) refers to certain of the examples given in 435,647 (now Patent No. 1,858,097) namely the following ones:- I

, Example 1 1000 parts of wood-pulp (moisture 9 to 10 per cent) or'l 0 parts of cotton linters (moisture 7 to 8 per grit) are steeped in 20,000 parts of caustic sod solution of 18 per cent strength at 15 C., and the reaction mixture is allowed to stand for 3 hours at room temperature. After this time the alkali cellulose is pressed down to 3400 parts and comminuted in a shredder for 3 hours at 12 to 13 C., whereupon 100 parts of a-monochlorohydrine are added graduallyv (i. e. in a few portions), and the reaction mass kneaded in a shredder for about 3 hours at C. Thereafter the reaction mass is transferred to a vessel provided with a lid, and kept in the closed vessel for 21 hours at 20 C.

A sample taken at the time shows that the mass in part has become soluble in dilute caustic soda solution (for instance of 10 per cent strength) and that the filtered solution of the material in NaOH solution, on being acidified with dilute sulphuric acid, yields a bulky precipitate.

The reaction mass is now placed in a filter press or on a straining cloth and-washed with water until free from alkali, whereupon it is pressed down to about three to four times the weight of the parent cellulose. The water content of the pressed product is determined by drying a sample at 105 Ci The mass is now (at 15 C.) well mixed with such an amount of water and caustic soda as, together with the water present in the mass, will give 20,000 parts of a caustic soda solution of 18 per cent strength.

The reaction mixture is now allowed to remain at room temperature for 3 hours, whereupon it is pressed down to 3400 parts to 4000 parts and comminuted in a shredder for 3 hours at 12 to 13 C. Immediately after shredding 600 parts of carbon bisulphide are added, and the reaction mass placed in a closed vessel and kept therein for 10 hours at 19 C. The excess carbon bisulphide is blown off during 15 minutes, and the xanthated mass is disolved in water and caustic soda, for example so as to yield a solutioncontaining about 5 to '7 per cent '01 the dry residue of the washed and pressed hydroxy-alkylated product and 8 per cent ofcaustic soda. 4

' The solution is practically tree from undis solved particles and precipitable with strong solutions of salts, for example ammonium chloride or sodium chloride or ammonium sulphate or alcohol, or acids, for instance sulphuric acid or hydrochloric acid, or acid salts, for instance sodium bisulphate.

- It is found that the precipitate obtained by addition of ethylor methyl alcohol under stirring, is collected on a filter, washed a few times with alcohol, extracted with ether and dried at room temperature under reduced pressure, is an almost colorless, flocculent or lumpy substance which is readily soluble in caustic alkali solution. Its solutions are precipitated on being acidified, for example with sulphuric acid. On being analyzed according to Zeisels method (decomposed in strong hydriodic acid) the substance obtained from the solution by precipitating it with alcohol as well as the washed and dried substance precipitated from the solution by means of sulphuric acid yields 1.79 per cent of CaH-zO.

' If both substances are boiled under reflux with an alcoholic caustic potash solution of 20 per cent strength or with an aqueous caustic potash solution of 20 per cent for 24 hours, all

four products are thoroughly washed until free from alkali, extracted with alcohol and ether, dried and the amount of 031110 determined therein.

Analyses (of particular samples) give the following C3H'zO-figures:

(1) Substance precipitated with alcohol boiled with alcoholic 1.93 per cent.

(2) Substance precipitated with alcohol and and caustic potash solution:

boiled with aqueous caustic potash solution: 1.89

per cent.

(3) Substance precipitated with sulphuric acid and boiled with alcoholic caustic potash solution: 1.78 per cent.

(4) Substance precipitated with sulphuric acid and boiled with aqueous caustic potash solution: 1.91 per cent. This propoxyl figure 1.78, mentioned above, corresponds to one dihydroxypropyl group to about 17CsHmO5-m0lecular units of cellulose.

Example 2 The process is conducted as in Example 1, with the difference that, instead of 100 parts, 200 parts of a-monochlorohydrine are employed.

The working up of the xanthate is carried out as in Example 1.

The properties of the final product and of its solutions are similar to those of the final product obtained in Example 1.

. Example! v The processis conducted as in Example 1, but with thejdifi'erence that, instead of the 100 parts of a-m'onochlorohydrine, 100 parts of ethylene chlorohydrine are added to the alkali cellulose. The .working up otthe xanthate is carried out as inlExample 1. v The properties of the final product and of its solutions'are similarto those of the final product obtainedin Example 1.

--Ea:ample 6 The process is conducted'as in one 01 the preceding examples, with the exception that, im-

mediately after havingbeen mixed with the 15 va-monochlorohydrine or ethylene chlorohydrine respectively for 3 hours, the reaction mass is washed and then dealt with as in any of the preceding examples.

The properties of the final product are similar 9 to those obtained in the preceding examples.

' Example 7 Mode of procedure as in any of the preceding examples, with the difference that the reaction Example. 8

1000 parts of wood-pulp (moisture 9 to 10 per cent) or 1000 parts of cotton'linters (moisture '7 to 8 per cent) are steeped in 20,000 parts of caustic soda solution of 18 per cent strength at 40 15 C., and the reaction mixture is allowed to stand for 3 hours at room temperature. After this time the alkali cellulose ispressed down to 3400 parts and comminuted in a shredder for 3 hours at l2"to 13 C., whereupon 100 parts of a-IIIOXIOChlOl'OhYdIil'lG are added gradually (e. g. in a"few portions) and the reaction mass kneaded in a shredder for about 3 hours at 20 C. Thereafter the reaction mass is transferred to a vessel, provided with a lid, and kept in the closed vessel for 21 hours at 20 C.

Immediately thereafter 600 parts of carbon bisulphide are added and allowed to act for 8 hours at 19 to 20 C. The excess carbon bisulphide is now blown off during 15 to 20 minutes, and the thus produced xanthate dissolved, for example in such a quantity of caustic soda and water that the solution contains the equivalent of about 5'to 6 per cent. of parent cellulose and 8 I per cent of NaOH.

The solution is practically free from undissolved particles and precipitable with strong solutionsof salts, for example ammonium chloride or sodium. chloride or ammonium sulphate, or alcohol, or acids, for instance sulphuric acid or hydrochloric acid, or acid salts, for instance sodium bisulphate.

Then the precipitate obtained by addition of ethylor methyl alcohol under stirring is collected on a filter, washed a few times with alcohol, extracted with ether and dried at room temperature under reduced pressure. The product is-an almost colorless, fiocculent or lumpy substance, which is readily soluble in caustic alkali solution and water. Both solutions are precipitated on being acidified, for example with sulphuric acid.

The analytical results are similar to those obtained in Example 1.

Example 9 Example 10 The process is conducted as in Example 8, but

with the diilerence that instead of 100 parts of' a-monochlorhydrine 200 parts of ethylene chlorhydrine are employed.

- The working up of the xanthate is carried out as in the preceding examples.

The properties of the final product obtained are similar to those of the product obtained in Ex ample 1.

Example 11 The process is conducted as in Example 8, but with the difference that, instead of 100 parts of a-monochlorhydrine, 300 parts 01' ethylene chlorhydrine are employed.

The working up of the xanthate is carried out as in one of the preceding examples.

The properties of the final product and of its solutions are similar to those of the final product I obtained in Example 1.

Example 12 The process is conducted as is Example 9, but

Example 15 1000 parts of wood-pulp (moisture 9 to 10 per cent) or 1000 parts of cotton linters (moisture TI to 8 per cent) are steeped in 20.000 parts 01' canstic soda solution of 18 per cent strength at 15 C., and the reaction mixture is allowed to stand for 3 hours at room temperature. After this time the alkali cellulose is pressed down to 3400 parts and comminuted in a shredder for 3 hours at 12 to 13 C. The comminuted mass is thereafter left in the shredder and its temperature raised to 20 C., whereupon 300 parts of ethylene chlorohydrine and immediately afterwards 600 parts of carbon bisulphide are added'the shredder well closed and the kneading continued for 5 hours at about 20 C. The excess carbon bisul-' phide is blown off during 15 'to 20 minutes, and the xanthate is dissolved in caustic soda and water in such proportions that the solution contains the equivalent of 3 per cent. of the parent.

' cellulose and 8 per cent of NaOH.

The working up 0! the xanthate is carried out- Example 17 '1000 parts of wood-pulp or cotton lintcrs are solutions are similar to those of the final product steeped in 20.000 parts of caustic soda solution of 18 per cent strength at 15 0., and the reaction mixture is allowed to stand for 3 hours at room temperature. After this time the alkali cellulose is pressed down to 3,400 parts and comminuted 5 in a shredder for 3 hours at 12 to 13 C., whereupon 200 parts of a-monochlorhydrine are added in a few portions, and the reaction mass kneaded in a shredder for 3 hours at 20 C. Thereafter the reaction mass is transferred to a m vessel, provided with a lid and kept in the closed vessel for 2| hours at 20 C.

A sample taken at that time shows that the mass in greater part has become soluble in dilute caustic soda solution (for instance of 10 per cent 15 strength), and that the filtered solution, on being acidified with dilute sulphuric acid, yields a bullw precipitate.

The mass is now dissolved in 75,000 parts of a caustic soda solution of 8 per cent strength, 20. wherein it dissolves not completely, but with a residue. After standing for 12 hours at'room temperature, the suspension is filtered and the clear filtrate precipitated by acidifying with sulphuric acid of 15 per cent strength. The fioccu- 2t lent precipitate is freed from the. mother liquor in a filterpress or on a straining cloth, washed with water until free from acid, pressed and after itswater content has been determined dissolved in such an amount of caustic soda and water as to yield a solution containing 7 per cent of the cellulose 1:2 dihydroxy-propyl ether and 8 per cent of NaOH. To this solution parts of carbon bisulphide (calculated on the weight of the cellulose 1:2 dihydroxy-propyl ether) are added, 35 and the reaction mixture kept shaken for 20 hours at 20 C.

The properties of the final product and of its obtained in Example 1. 40

The CaHvO-figures (on particular samples) are as follows:

(1) Body precipitated with sulphuric acid: 2.53%.

(2) Body P ecipitated with sulphuric acid and 45- boiled with. alcoholic caustic potash solution: 2.05%.

- Example 18 Example 19 Mode of procedure as in Examples 1'7 or 18, but with the exception that, instead of 200 parts, 300 parts of u-monochlorohydrine are used.

The working up of the xanthate is carried out 65 as in Example 17.

The properties of the final product and of its solution are similar to those of the final product obtained in Example 17.

Example 20 The process is conducted as in Example 18, but with the diflference that, instead of the 200 parts of a-monochlorohydrlne, 200 parts of ethylene chlorohydrine are used. 75

Example 21 I The process is conducted as in Example 17, but with the difierence that, instead of the 200 parts of a-monochlorohydrine, 300 parts of ethylene chlorohydrine are employed.

In the specification and claims, wherever the context permits, "the expression "cellulose includes the near conversion products and oxida-- tion products of cellulose such as cellulose hydrate, hydroceliuiose and oxycellulose.

The expression hydroxy-alkyl derivative of cellulose" or bydroxy-alkyl ether of cellulose" or hydroxy-alkyl cellulose" used in the specification and claims includes thosederivatives of cellulose in which at least one hydroxylhydrogen atom of cellulose, of a cellulose hydrate, of a hydrocellulose, or of an oxycellulose is replaced a monohalohydrine in the-presence of an alkali.

The expression "halohydrine" used in the specification andthe claims, includes (wherever the context permits) the compounds containing both a halogen and a hydr'oxyll group which may be regarded as being derived from poiyhydrorw alcohol by the partial exchange of the hydroxyl groups and chlorine, bromine or iodine (or from a monoor polyhydroxy alcohol by the substi .tution of one or more hydrogen atoms in the alcohol (radical) and the derivatives (such as the V esters) or internal anhydrides (such as epi-' chiorohydrine) of such halohydrines, or substances or mixtures of substances which are capable of yielding such halohydrines.

The expression strong mineral acids denotes sulphuric acid of at least 35 per cent oi H2804, preferably at least 45 per cent. of H2804, and as regards the other mineral acids, solutions of equivalent strength.

Instead of sulphuric acid of at least 35% strength or stronger, nitric acid of 60 to 90% strength, or phosphoric acid of 67.5 to 99% strength, or arsenic acid of 60 to 90% strength, or a solution containing 60% of ZnClz and 5 to 6% of HCl, or a strong solution of zinc chloride without addition of'HCl, can be used, as plasticizing agents, the use of such baths being included in the appended claims, in the expression plasticizing liquids. I

The expression strong sulphuric acid" or sulphuric acid containing at least about 35 per per cent. of sulphuric 'acid monohydrate denotes sulphuric acid having a content of 35 to 98 per cent. of H2804.

The term hydroxyalkyl is intended to include the halogenated or non-halogenated radicals of dior polyhydric alcohols in conjunction with one or more oxygens or hydroxyls.

The expression shaped artificial structures" used in the specification and claims is intended to include: --artiflcial-threads, particularly artificial silk and staple fibre, film, shaped plastic masses, applied finishes and, coatings of every kind, flnishings, fillings, and dressings on textile fabrics, sizings on yarn, paper-like surfacing, applied paper sizings, artificial leather, transparent paper or cloth, book cloth and tracing-cloth and the like.

droxyalkyl cellulose xanthate into the shape of the desired artificial structure, and acting upon the shaped solution with a coagulating agent.

2. A process of making artificial structures which comprises bringing a solution of a hydroxy-alkyl cellulosexanthate, which hydroxyalkvl cellulose is made by treating cellulose with a hydroxy-alkylating agent in the presence of alkali, into the shape of the desired artificial structure, and acting upon the shaped solution with a coagulating agent.

3. A process '0! making artificial structures which comprises bringing a solution of a hydroxy-alkyl cellulose xanthate, which hydroxyalkyl cellulose has been made by treating cellul lose with a halohydrine in the presence of alkali, into the shape of the desired artificial structure, and acting upon the shaped solution with a coagulating agent.

4. A process as in claim 1, in which a shaped stream of a hydroxy-alkvl cellulose xanthate solution is caused to enter through at least one suitably shaped opening into a coagulating bath.

a 5. A process as covered in claim 1, wherein any coagulating bath known in the viscose industry is used as the coagulating agent.

6. A process as in claim 1, in which the solution of the xanthate of the hydroxy-alkyl derivative of cellulose also contains cellulose xanthate.

7. A process as covered in claim 1, wherein the t0 hydroxy-alkyl cellulose xanthate is a xanthate of a hydroxy-alkyl derivative of cellulose which hydroxy-alkyl cellulose is itself at least partially soluble in caustic alkali solution.

8. A process as in claim 1, in which the artificial structure is treated with a shrinking agent.

9. A process as covered in claim 1, wherein the xanthate of a hydroxy-alkyl derivative of cellulose is a xanthate of a monohydroxy-alkyl derivative, and is made by reacting upon a cellulosic 40 material with a hydroxy alkylating reagent in the presence of an alkali.

10. A process of making a shaped artificial structure, which comprises giving to a solution containing a xanthate of a hydroxyalk'yl ether of cellulose, prepared by acting upon cellulose with a hydroxy-alkylating agent in presence of caustic alkali, the shape of an artificial structure by extruding said solution through a shaped opening directly into a coagulating bath, and

continuously drawing the coagulated artificial staructure away from said shaped opening.

11. A process as covered in claim 10, wherein during a part ofits journey from the shaped opening to a collecting device,- the artificial structure is given a stretching additional to such as is necessary for the formation of the artificial structure.

12. A process as covered in claim 10, in which the shaped opening is of such a construction as to deliver a thread-like stream of the solution.

13. A process as covered in claim 10, in which the shaped opening is of such a construction as to deliver a thread-likestream of the solution and in which the thread is under tension during a portion of its journey from said opening to the collecting device.

14. A process as covered in claim 10, wherein additional stretch is applied to the artificial structure while in the bath. v

15. A process as covered in claim 10, wherein additional stretch is applied to the artificial structure while between the bath and the collecting device. 75

18... A processas coveredinclaim 17, whereina solution of a-hydroxy alkylucellulose xanthate,

having the .formof'therdesired artificial structure is acted upon with-an agent which has a coagulating'efiecton the shaped solution and which also has a plasticizing effect on the freshly coagulatedartificialstructure,

, 19. A process as covered in claim 1'7, wherein the coagulating and plasticizing are conducted in a bath of a. medium. containing at least per cent. of sulphuric. acid rhqnohydrate.

. 20. A process as in claim 17, in which the coagulating and "plasticiz pg actions are effected in a bath containing mineral acid equivalent in strength to sulphuric acid of at least 35% H2804. 21; A process whichccmprises treating a solution containing a 'xanthate of a hydroxy-alkyl derivative=of"cellulose,having the form of an artificial structure; with-a coagulating agent and thereafter with a plasticizing agent.

22. A process which comprises treating a solution' emai'ning' a-xan'thate of a hydroxy-alkyl derivative of cellulose, having the form of an artificial structure, with a coagulating agent and thereafter with a bath containing a mineral acid equivalent to sulphuric acid of at least 35% strength.

23. A process which comprises making a hydroxy-alkyl derivative of cellulose by reacting upon cellulose with a hydroxy-alkylating agent in the presence of an alkali, xanthating said hydroxy-alkyl derivative of cellulose, and treating the xanthate in solution while having the form of the desired artificial structure, with a coagulating agent, a xanthate of a hydroxy-alkyl derivative of cellulose, having the form of an artificial structure, with a coagulating agent and thereafter with a bath containing at least 35% 0f H2SO4.

24. Process as in claim 17, in which the xanthate solution contains caustic alkali.

25. A process as covered inclaim 10, wherein a softening agent is added to the solution of the hydroxy-alkyl cellulose xanthate before its conversion into the artificial structure.

26. A process as referred to in claim 17, wherein the action of the plasticizing agent is checked at a time not considerably after the arrival of the artificial structure at a collecting device.

27. A process of making an artificial structure which comprises forming a solution of a muthate of a hydroxy-alkyl derivative of cellulose, into the form of an artificial structure, and thereafter plasticizing such artificial structure during the completion of its manufacture, by treating same with a mineral acid of a strength equivalent to sulphuric acid of at least 35%.

28. A process of making an artificial structure which comprises forming a solution of a xanthate of a hydroxy-alky'l derivative of cellulose, into the form of an artificial structure, and thereafter plasticizing such artificial structure during the completion of its manufacture, by treating same with a mineral-acid of .a strength equivalent to sulphuric acid of at least 35% and checking the action of -said.mineral;.acid, when the plastic has been sufliciently accomplished.

1129. A; process as inclaim, 28, in checkingtis. eflected by refrigerating the artificial structure.-. a 1

. -30. .A-process as in .claim 28., in which the checkingdseifected by washing. ."31. A-proeess as inclaim 1-, in which a-.halo.- hydrine is added .to the solution of the hydroxy.- alkyi .-cellu-lose xanthate solution to thereby improve the final product. i

- 32. A process. as covered in claim 1, wherein the hydroxy-alkyl cellulose xanthate solution to be worked-up into an artificial structure is produced by treating an alkaline solution containing a hydroxy-alkyl derivative of cellulose, which is at least partially soluble in caustic alkali solution but insoluble in water, with carbon disulphide.

33. A process as covered in claim 1, wherein the-solution to be worked up into an artificial material is produced by a method which includes exposing a reaction product resulting from the treatment of alkali cellulosewith a halohydrine, to the action of carbon bisulphide in the presence of sufiicient caustic alkali for efi'ecting the xanthating reaction.

34. A process which comprises introducing a solution containing a xanthate of a hydroxyalkyl derivative of cellulose through a shaped opening of such a shape as to form an artificial structure, into a setting bath, plasticizing the artificial structure by action thereon with a bath having a plasticizing action at least equal to that of sulphuric acid of 35% concentration, and leading said artificial structure to a collecting device.

which the 35. A process as covered in claim 34 in which 40 the shaped solution is delivered into a setting bath of which the acidity (figured as sulphuric acid) is below 35%, to coagulate the artificial structure, and in which process the coaguiated artificial structure then passes to another bath of mineral acid of a strength equivalent to at least 35% H2804 to plasticize said artificial structure.

36. Process as covered in claim 34, in which the setting bath is a solution containing a mineral acid of a strength equivalent to sulphuric acid of at least 35%, to coagulate and plasticize the artificial structure in said bath.

37. A process as covered in claim 1, wherein the solution to be worked up into an artificial structure, is produced by exposing the crude re action mass resulting from the treatment of alkali cellulose with a halohydrine, to the action of carbon bisulphide, and thereafter dissolving the thus obtained reaction mass.

38. A process as covered in claim 1, wherein the solution to be worked up into an artificial structure, isv produced by reacting upon cellulose with a halohydrine, and treating the hydroxyalkyl derivative of cellulose thereby produced, while in the presence of a caustic alkali, with carbon bisulphide and thereafter dissolving the thus obtained reaction mass.

39. The herein described process of producing artificial structures of high tensile strength and of at least fairly good extensibility which comprises introducing a shaped stream of a solution of a xanthate of an etherified derivative of cellulose intoa coagulating bath and plasticizing the freshly coagulated artificial structure, all without subjecting the formed artificial structure to additional stretch, after contacting the same with the plasticizing agent.

40. The herein described process of producing artificial structures of high tensile strength and of at least fairly good extensibility which comprises introducing a shaped stream of a solution of a xanthate of a hydroxy-alkyl ether of cellulose formed by reaction of a halogenhydrin upon a cellulosic body in the presence of an alkali, into a coagulating bath, all without subjecting the formed artificial structure to additional stretch, after contacting the same with the coagulating bath.

41. As new products, shaped artificial structures containing a hydroxy-alkyl derivative of cellulose, and which products have a tenacity, in the dry state, equivalent to over 2 grams per denier and which products have an extensibility of at least 7%, which products are produced by shaping a solution of a xanthate of a hydroxyalkyl derivative of cellulose into the appropriate shape, and coagulating the so shaped material.

42. Artificial thread or filaments containing a hydroxy-alkyl derivative of cellulose, such product having a dry tenacity of over 2 grams per denier, and an extensibility of over 7%, which products are produced by shaping a solution of a xanthate of a hydroxy-allryl derivative of cellulose into the appropriate shape, and coagulating the so shaped material.

43. As a new product, an artificial thread which consists essentially of at least one hydroxycellulose and which products have a dry tenacity 10 equal to that of a thread having a dry tenacity not less than 2 grams per denier, which products are produced by shaping a solution of a xanthate of a hydroxy-alkyl derivative of cellulose into the appropriate shape, and coagulating the so shaped 15 material.

45. As a new product, artificial thread containing a hydroxy-alkyl derivative of cellulose, which thread has a dry tenacity exceeding 2 grams per denier, and a wet tenacity exceeding 1 gram per 20 denier, and an extensibility exceeding 7%.

46. A process as claimed in claim 1, in which a precipitate obtained by acidifying the solution of the hydroxy-alkyl cellulose xanthate, with sulphuric acid, after said precipitate is washed 0 and dried, upon being decomposed by strong hydriodic acid according to Zeisel's method, yields alkyl iodide in an amount which is stoichiometrically equivalent to about 1.78% to 2.81% 30 oi propoxyl.

LEON IJLIENFEID.