US1881740A - Artificial material and process for making same - Google Patents

Description

Patented Oct. 11, 1932 T PATENT orFicE LEON LiLInNrELn, or VIENNA, AUSTRIA- ARTIFICIAL MATERIAL AND iROCESS FOR MAKING SAIaIE No Drawing. Original application filed-J'urieB, 1926, Serial No. 113,582, and in Austria January 5, 1926.

Divided and this application'filed September 19, 1929. Serial No. 393,829.

' Heretofore strong mineral acids (i. e. acids which exercise a plasticizing effect, such as H SO of 45% or 50% or stronger or .HCl of 25% or stronger) have not been used as 5 coagulating or spinning baths in the manufacture of artificial materials, such as artificial threads and films from viscose, because, by means of such acids, the formation of a lustrous thread, band, film or the like has been considered impossible. (See U. S. Patent 836,452.) I

Now I have discovered that this holds good with a strong halogen hydracid, such ,as'hydrochloric acid containing up to about 25 per cent. of H01, but that hydrochloric acid containing about to 40 per cent. of H01, and preferably hydrochloric'acid containing more than 25 per cent, for example per cent. of HCl, when used as coagulating or spinning bath for'viscose brought into the form of a thread or film or band or the like, yieldsthreads, film, bands'or the like which have a good lustre. 1 But-what is still more important: I have I 213 discovered that threads, films, bands'or the like manufactured from viscose by means of hydrochloric acid containing at least about '25 per cent. of HCl, preferably however more v than 25 per cent, of HCl, for example 35 so per cent. of HCl, with regard to their tensile strength, surpass any artificial thread known hitherto and in some cases approach, in some cases equal,and in some cases even surpass v even natural fibres, such as cotton or Wool 35 or real silk. For example, it offers no difficulty to produce according to the present process, artificial silk or staple fibre that has a dry tenacity of more than 2 grammes and even. more than 3 grammes per denier, for ex- 4 ample?) or even 3, 5 to 4 grammes per denier and in some cases even more than 4 grammes per denier, and a wet tenacity of 1,5 to 2,5 grammes per denier and more.

A further advantage of the artificial threads manufactured according to the present process over ordinaryviscose silk is their higher resistance to aqueous alkalles and to soa I have. further found thatit is advantageous to the tensile strength of the artificial materials,particularlythreads,manufactured according to the present process, to stretch the threads either in the coagulating bath or between the coagulating bath and the collecting' device or in both places.

I The process is carried out in such a manner that viscose is brought into the form of an artificial material and coagulated by means of hydrochloric acid, containing at least 25 per cent. of HCl, for example hydrochloric acid containing 35 per cent. of by drogen chloride. In most cases, for instance in manufacturing artificial threads orfilaments, or films, or hands, or plates, this can be effected in such a manner that the viscose is caused to pass through suitably formed openings into hydrochloric acid, containing 25 to per cent. of HCl, for instance hydrochloric acid of 35 per cent. strength. The strong hydrochloric acid'may be employed by itself or in admixture with one or more suitable inorganic substances, for example with another strong mineral acid such as phosphoric acid, or with a neutral or acid salt,

such as sodium sulphate, sodium bisulphate, ammonium sulphate, magnesium sulphate, zinc sulphate, sodium bisulphite, sodium sulphite, sodium nitrite, boric acid or the like. To the strong hydrochloric acid or its mixture with another strong acid or with one or more of the inorganic substances mentioned above, there may be added one or more organic bodies, such as glycerol or a sugar, for example glucose, or alcohol or a salt of an organic base, for'exampleof aniline, or an organic acid, such as acetic acid or formic acid or lactic acid or oxalic acid. If a salt is added which is capable of reacting with the strong hydrochloric acid, the strength of the acid should be so chosen that, after the amount required for the reaction is used up, the coagulating bath contains .freerhydrochloric acid of the desired strength, but at any rate not less than 25 parts by weight of hydrogen chloride in 100 parts'by weight of the precipitating bath.

The suitable strength of the acid depends. ceteris paribus, partly onthe time ofmatur ing given the alkali cellulose, partly on the time ofripening given the finished viscose and partly on the viscosity or amount of cellulose contained in the viscose. As a rule, to which however the invention is not confined, it may be stated that with viscoses which have matured for several days and/or viscoses that have been prepared from alkali 7 cellulose that has been allowed to mature for a longer time, for example 2 to 3 days and/or viscoses that are poor in cellulose or little viscous respectively, preferably an acid is used which is not so strong as would be used when treating viscoses that have not been allowed to mature or have been allowed to mature for a short time (for instance 3 to 48 hours) only and/or have been prepared from alkali cellulose that has been not allowed to .mature at all orhas been allowed to mature for ashorter time than usual, for

.examplefor'3 to 48 hours, and/or are rich in cellulose or viscous respectively. The strength of theacid is further, to a certain degree, dependent on the length of immersi'on in the coagulating bath-and the tension given the coagulated material in theacid or outside it, tor example between the coagulat .ing bath and the collecting device, for ex ample bobbin. V The precipitating bath may be kept at room temperature or at a temperature exceeding room. temperature, for example at 25,1;0'50" 0., or at a temperature lower than room temperature, for example at O to 5 C.,

.or'even below 0 (3., for example at from 1'to-10 G.

.The length of immersion of the thread or filament or plate or film or band in the strong acid or in the bath containing it may be varied within wide limits, for examples from a'cid,.be heated or steamed before or after.

drying. r r

a Any viscose prepared according to any process or any method known hitherto may be used in the present process. The process gives excellent results with viscoses that are prepared from alkali cellulose that has been allowed to mature for such a time as it is commonly given the alkali cellulose in the artificial silk or film art and also with viscoses-in the manufacture of which alkali celluloseis employed which has'inot been-allowed to mature at'all or has been allowed to. mature fora shorter time than such as. is

usual in the artificial silk or film art, i. e. not longer than about 48 hours, for example 1 to 24 hours. I I

The present process gives excellent results with such viscoses also as are prepared without making alkali cellulose, i. e. by direct mixing the ingredients.

If desired, there may be added to the viscose one or more suitable substances known in the viscose-silk art, for example glycerol or glucose orsodium sulphate or sodium sulphlte or sodium blsulplnte or ammonium sulphate or an alkali silicate or an alkali aluminate or ammon a. i i

The process being open to manifold variations, it isnotintended to confine the invention tot-he following examples given for the practical carrying outof the process.

. (a)."10O,parts'by weight of sulphite-pulp are impregnated with 900 to .2000 parts by weight of. a caustic soda solution of 18 per cent. strength at 15 to "18 (1., and themixture allowed to stand for ;3 to V2% hours. Then the mass is pressed to 300 to 400 parts by weight, and the residue comminuted by hand or, in a: suitable apparatus, for instance in a cooled shredder. The comminuted soda cellulose is then kept for tof72 hours at room temperature, whereafter 30 to '60 parts by weight of carbon bisulphideare added, and the reacting mixture,,preferably under stirring (for example in a closed kneading machine) or agitating (for example in a sulphidizing drum), kept for several (for example lto 8) hours: at 16 to 20 C. Thereafter the excess of the carbon 'b'isulphide is removed by driving oil or evacuating, and

' then'the sulphidized mass is dissolvedin water or dilute caustic sodasolution in such a manner that the viscose contains about .8 to 12 per cent. of celluloseldetermined in the known manner by precipitating with acid, washing. and drying), If caustic soda solution is used, it maybe for example so chosen that, if the amount of caustic soda thatwas present in the soda celluloseis taken into consideration the final viscose contains 5 to S per cent. caustic soda. The viscose solution thus obtainedis then filtered in a known manner through cotton wool or a densecott on fabric or through both and freed'from. gas bubbles if any. Immediately after, or after it has been allowed to ripen at 16-18 C. for a shorter (for example 12 hours to'two days) or a longer (forexample four days or seven days) time, the viscose is spun in a known manner into oneofthe following precipitating baths:

(1). Hydrochloric acid of 25 to 40 per cent. strength, or" 7 (2) Hydrochloric acid strength, or I V V 1' j (3) A solution containing,9.345;to 9.48 per of 35 per cent 1 by weight of ammonium sulphate and '25 to 40 per cent hydrogenchloride.

. p (4) A solution containing to 7.5 per cent.

by weight of glucose and 25 to 40 per cent.

hydrogen chloride.

The temperature of the coagulating bath is kept at 0 to 16" (1., for instancel at 8 0.,

The length of immersion in the coagulatbath of the threads forming therein may be short, for example centimetres, or more long, for instance from'80 to 100 centimetres and more. They are then collected in a known manner on a bobbin or in a spinning centrifuge which may be placed either by the precipitating bath or at a distance from to 120 centimetres from the bath,

V whereupon the threads are washed and dried.

The threads may be stretched in any known manner whilst they are in the coagulating bath, or after they have been removed from the bath, i. e. between the coagulating bath and the collecting device. This may be done for example either by choosing a more or less long distance between the bath and the collecting device, or by leading the threads over rods or hooks arranged between the nozit of speed possible is dependent partly upon the temperature of the coagulating bath, partly upon the length of immersion, partly upon the distance between the coagulating bath and the collecting device, partly upon the degree of stretching given the thread during spinning, and partly upon the quantity of viscose delivered by the pump. The following examples to which, however, the process is not intended to be limited, may be adduced for the purpose of illustration.

(1) If the coagulating bath is used at a temperature below 0 (3., for example at minus 5 (1, and if the length of immersion is 60 to 120, for example 80 centimetres, and if the distance between the coagulating bath and the collecting device, for example bobbin, is 60 to 150 centimetres, for instance 120 centimetres, and if the stretching given the thread between the coagulating bath and the collecting device is comparatively high, and if the pump delivers about 2 to 3 cubic centimetres of viscose a minute, then the speed of 18 to 26 meters a minute, at the outside of meters a minute is recommendable.

(2) If all spinning conditions, remain the same as in (1), except that the pump delivers-4to 5 cubic centimetres of viscose a minute, then a speed of to 60 meters a minute may be employed.

(3) If the spinning conditions are exact- 1y as in (1) except that the temperature of the coagulating bath is plus 4 to plus 25 C.,'for example 8 0., the speed may be to meters a minute.

If in (1) the length of immersion hr the distance between the coagulating bath and the collecting device or both are shortened, the speed may be increased.

Before being washed, the threads may be treated in any known manner with a bath known in the viscose-silk art, for example a solution of sodium bisulphate or sodium bisnilphite or with dilute sulphuric acid or the li e. i

The Washed threads may, before or after drying, be heated (for example at IOU-110 C.) or steamed.

They may also be treated with any desulphurating or bleaching agent known in the viscose art. 1

(b). The mode of operation is as in (a), except that 75 to 150 parts by weight of car- 'bon bisulphide are employed for the sulphidizing of the soda-cellulose.

(a). The mode of operation is as in (a) or (b), with the diiference that the sodacellulose is pressed to 200 parts by Weight.

[I (a) to (0) strength.

(2) Hydrochloric acid strength.

(3) A solution containing 9.34 to 9.48 per cent. ammonium sulphate and 25 to 4.0 per cent of hydrogen chloride.

1) A solution containing 5 to 7.5 per cent. by weight of glucose and 25 to 40 per cent. hydrogen chloride.

Mode of operation as in Example I (a) or I (b) or I (0) oras in Example II (a) or II (b) or II (0) with the exception that the viscose is not allowed to mature at all or to mature for 12 to 48 hours only, and that as coagulating bath hydrochloric acid of 25 to 40 per cent. strength, for instance hydrochloric acid of 35 per cent. strength at 6 to 10 C. is used. In using so strong an acid it is preferable to run the spinning at a high speed, for exof 35 per cent.

ample 40 to 60 meters a minute.

IV (a) to (e) (a). 100 parts by weight of sulphite pulp residue comminuted byhandor in a suitable apparatus, for instance in a cooled shredden,

Immediately or soon (for. example 1 hour) after the comminutionhas taken place, 30 to 60 parts by weight of carbon bisulphide are adde d,and the reacting mixture, preferably under stirring (for example in a closed knead- 7 ing machine) or agitating (forexample in a sulphidizing drum) kept for several (for example 4 to 12 hours at 16 to 20 0. Thereafter theexcess of the carbon bisulphide'is weight of a caustic soda; solution of-6,5 to 10 removed by driving off or evacuating, and the sulphidized mass, the weight of which generally amounts to from about330 to 400 parts by weight, is dissolved in 650 to 900 parts. by

per cent. strength. The viscose solution thus obtained is then filtered in a known manner through cotton wool or a dense cotton fabric or through both and freed from gas bubbles if any. Immediately after, or after it has been allowed to ripen'at1618 C. for a shorter (for example 12 hours to two days) or a longer (for example four days or seven days) time, the viscose is spun in a knownmanner into one of the following precipitatingbaths (1) Hydrochloric acid of'25 to 40 per cent. strength, or V (2) Hydrochloric acid of 35 per cent. stren'gtlnorj 1 7 (3) A solution containing 9.34 to 9.48 per cent. byweightof ammonium sulphate and to 40 per cent. hydrogen chloride.

A solution containing 5 to 7.5 per cent. by Weight of glucose and 25 to 40 per cent.

hydrogen chloride.,

The temperature of the coagulating bath is kept at 0 to16 C.,for instance at 8 C., or at 4 130 8 C.

The spinning and treating of the'threads' v during and after spinning is done in the same manner as described in the foregoing eXamles.

(5).,The mode of operationis as in (a), with the difierence that a caustic soda solution of 3 to 5 per cent. strength is employed 1 for the dissolvingof the sulphidized sodacellulose. Accordingly, the viscose is somewhat more viscous.

(5), except that 75 to 150 parts by weight of carbon bisulphide are. employed for the sulphidizing of the soda-cellulose.

(cl). The mode of operation is as in (a) or (b) or (c), with the difference that the sodacellulose is pressed to 200 partsby weight.

(e). The mode of operation is as in (a) or (b) or (0) or (d), with the difference that hydrochloric acidof 25 to 40 per cent. strength (0). The mode-of operation is as. in (a) or at 8 used ajs coagulating bath, the viscose being 12 to 48hours old and the. speed of spinning about to meters a minute.

. V? to The method of preparing the viscos'e'differs from that described in IV (a) ,or (b) or ('0) or (d) or (e) in that the soda-cellulose, after pressing and comminuting and before being sulphidized, is allowed to ripen for 3 to 24 hours at 16 to 20 C. V The amount and concentration of the caustic soda solution used for the dissolving of the sulphidizedma'ss. may be equal to those used in Example IV or somewhat lower, for example so as to produce a 1 0 tov 12 per cent.

viscose" (calculated on starting cellulose).

' The working up into threads. is; edectedas in IV (a) tote). v I

" V! (a) to. (d)

(a). 80400 parts by weight or finelydi- 'vided sulphiteepulp or bleached cotton .or

.mixed with 920900 parts by weight of a' causticsoda solution of 8 to 10 per cent. strength. To this mixture. 40 to 150 parts by weight of carbon bi'sulphide are added and the reacting mixture kept at room tem-' viscose is spun in a known manner into one of the following coagulating baths:

' (1) Hydrochloric acidof 25 to 40 per cent, strength, or

(2) Hydrochloric acid of 3w5 per cent.

strength, or p v v (3) A solution containing 9.34 to 9.48 per cent. by weight of'ammonium sulphate and 25 to 40 per cent. hydrogen chloride.

(4) Asolution containing5 to 7.5 per cent. by weight-of glucose and 25 to 40 per cent. hydrogen chloride. 1 V

lhetemperature of the coagulating bathis kept at 0 to 16 (3., for'instance at8. C. or at --4to8 The spinning and treating of the threads is done as in the foregoing examples.

(6). ,Mode of operation as in ,(a) with the exception that the viscose is prepared according to, the method 3 described in the British Patent 212,865, for example accord ing to the following examples of said specification; I (a) to (e) or' II (a) to "(0) or III(a) to (0) or IV (a) to (e) or V (a) to (b) or VI (a) to (0) or VII or VIII or-IX or X or XII or XIII.

. (0'). Mode of operation asin (a) or (b),

with the exception that, before or after the addition of carbon bisulphide takes place, a small quantity of a catalyzer is added to the mixture of the cellulosic body with the caustic alkali solution, forexample 0,2 to 1 parts by weight of a soluble chromic salt or nickel salt or iron salt.

(d). Mode of operation as in (a) or (b),

. with the difierence that, before or after the addition of carbon bisulphide takes place, a small quantity of a soluble peroxide, such as 5 to parts by weight of sodium peroxide to 100 parts by weight of starting cellulose are added.

' VII J the weight of the sulphidized mass being 330 parts. The final viscose contains 8 per cent. of starting cellulose.

The filtering and spinning of this viscose and the treatment of the threads is done as in the previous examples.

Examples for producing staple fibre follow automatically from the forego ng examples.

According to the foregoing examples, it is possible to obtain artificial silk or staple fibre which has a considerably higher dry and wet tenacity than silk spun under same spinning conditions, but by means of chemicals customary in the viscose silk-art, for example by using a known precipitating bath. For example: It is not difiicult to produce after the present process artificial silk having a dry tenacity of more than 2 grammes per denier, even more than 3 grammes per denier, for example 3 grammes to a grammes per denier and a wet tenacity of 1,5 to 2,5 grammes per denier and more.

VIII

A viscose prepared as described in Example I or II or III or IV or VI or VII is caused to pass through a suitable hopper or slit in one of the coagulating liquors mentioned in these examples,and after having left the precipitating bath, is washed and dried in any known manner.

A cotton fabric is impregnated or filled or coated once or several times with a viscose prepared according to one of the methods described in Example I or II or III or IV or V or VI or VII or VIII, for which purpose any suitable machine, such as a padding machine or a back filling machine or a spreading machine may be employed. To the viscose there may be added a filling substance, for instance talcum or china clay or a colouring matter or a pigment such as mica, or soot or a mineral colour or the like. The impregnated or coated material is, without being dried, optionally in the stretched state, taken through one of the precipitating baths described in Example I, whereupon thematerial is washed and dried.

Instead of strong hydrochloric acid there may be used in the foregoing examples a strong nitric acid, for example such as contains 60 to 90 per cent. of HNOg, or phosphoric acid, for example of 1,5 to 1,86 specific gravity, (i. e. about 67.5 to 99% H PO or arsenic acid, for example such as contains from 60 to 90 per cent. of H AsO In the foregoing examples, in the preparation of viscose, instead of wood pulp, there may be used bleached cotton, or cellulose treated in the cold or in the heat with dilute acids, for example hydrochloric or sulphuric acid, in short any kind of cellulosic bodies employed in, or proposed for the manufacture of viscose.

The expressionstrong hydrochloric acid or hydrochloric acid containing at least 25 per cent. of hydrogen chloride means in the description and claims hydrochloric acid of 25 per cent. strength and above.

The expression: artificial material in the description and claims is intended to mean: artificial threads and filaments of any kind, for example artificial silk, staple fibre, artificial cotton, artificial wool, artificial hair, films, plates, coatings and fillings of any kind. v

The expression cellulose is intended to mean cellulose or cellulose hydrate, as the body regenerated from viscose is regarded by some cellulose chemists as cellulose by others as cellulose hydrate.

The expression heating in the claims is intended to cover any known kind ofheating, steaming included.

The statements in the description and claims regarding percentages relate to percentages by weight.

The present application is a division of my copending application Ser. No. 113,582 filed June 3, 1926.

Having described my invention, I claim:

1. A process which comprises forming viscose into an artificial material, and contacting the same with an acid selected from the herein described group consisting of hydrochloric acid, nitric acid, phosphoric acid and arsenic acid, of a strength suflicient to plasticize the precipitated cellulose.

2. The process of coagulating a viscose 2 which 'comprises contacting it with hyclrochloricfacidofat'least about to 4:0 per cent.

strength, I

3. The process of coagulating a viscose which comprises-contacting it 'with'a liquid which contains at least about 25 to 40 per cent.

hydrogen chloride.

' 4. The process o lflmanufacturing artificial thread of high dry tenacity which comprises contacting a threadlike stream of a viscose witha liquid which contains at least about 25 to 4:0percent. hydrogen chloride.

5.-The process of manufacturing artificial 7 material which comprises bringing a viscose into the form o'f an artificial material; acting upon it witha liquid which contains at least about 25 to l0 per cent. hydrochloric acid to coagulate the viscose and washing the coagulated viscose.

' 6. A-process whichcomprises forming an artificial'materialfrom viscose and treating said artificial material with hydrochloric 7 acid of a concentration sutficient to -p-lasticize precipltated cellulose. V 7. A. process which comprises contacting viscose witha phosphoric acid bath of about 1.5;to 1.86 specific gravity;

8. Aprocess which comprises shaping viscose into" the shape of an artificlal mater] a1 and contacting same with phosphoric acid of at least 67.5%str'ength.

viscose'with a nitric'acid 9. A'pro'cesswhich comprises contacting bath of about to strength. i r 10. A process which comprises shaping viscose into the shape of an artificial material and contactingfthe same with nitric acid ofat least 60% concentration.

-11. A process which comprises forming viscose into the shape of an artificial material, and subjecting said formed material I to contact with an acid bath selected from the herein describeolgroup consisting of (a) a bath containing about 25 to 40% of H01 (6) a bath containing about 60 to 90% of HNO' (c) a bath containing about 67.5- to 99% of H PO and (01) abath containing about 60 to 90% of H AsO c In testimony whereof I affiX, my signature.

LEON LILIENFELD. iv