DE886950C - Process for the production of artificial threads or fibers from milk protein - Google Patents

Description

The invention relates to a method of production of artificial fibers.

The man-made filaments or fibers currently produced on a large scale almost exist made exclusively of cellulose, which has been dissolved into a viscous mass by various methods which is subsequently converted into threads and fibers; these artificial structures have one elemental composition that is similar to that of vegetable textile fibers, especially the Cotton. Consequently, some properties of these artificial fibers are also similar to those of identical to vegetable textile fibers, namely

in terms of thermal conductivity, flame safety and dyeability.

The purpose of the present invention is now Manufacture of artificial threads or fibers, which in terms of composition and what thermal conductivity, Flame safety and dyeability concerns that are similar to natural wool and therefore may also be called synthetic wool.

The method according to the invention for the production of artificial structures from milk protein is that you have a spinning solution that consists of an excess of acid over the acidic

Coagulation of casein in skimmed milk treated theoretically required amount of acid Casein dissolved in alkali and matured in the alkaline solution is made into threads and the filaments are coagulated in acidic saline baths, in a deswelling bath with a Hardening agent, preferably formaldehyde, treated, washed and optionally post-treated,

ίο The manufacturing process breaks down into the following essential phases:

i. The extraction of the raw material casein from skimmed milk. The different types of casein that currently produced in the cheese factories are suitable as textile casein. Through numerous attempts it was found that these caseins can be processed into threads and fibers, im but are generally too viscous to ensure regular spinning; It was also found that the threads obtained from these caseins consist of glued individual threads, so that they are brittle after drying. These difficulties occur both when using tactical casein (namely the casein produced by coagulation of the skimmed milk obtained by means of spontaneous acid fermentation at appropriate temperatures) as well as When using casein, the milk is immediately acidified by adding acids has been obtained by known methods. Cause all processes known to date the coagulation of casein by acidic means, the amount being added to milk or intentionally limiting acid generated spontaneously by acidic fermentation in milk to the amount that is just required to coagulate the Carry out caseins while carefully avoiding an excess of acid, which, as before claims to result in a re-dissolution of the casein.

However, this re-dissolution persists after numerous Experiments carried out by the inventor not actually, but only apparently. The acid coagulation of the casein is now according to the invention designed in such a way that what is avoided in the manufacture of common commercial caseins is sought and what has been referred to by experts as the redissolution of casein is, is caused on purpose, d. H. an excess of acid is used.

The following example explains how it works:

100 l of skimmed milk are added in two portions at 20 ° 250 ecm sulfuric acid of 66% Be, to which 2250 ecm water have been previously added ", a casein is obtained which is suitable for the production of artificial threads or fibers; the acid number of the whey at the time of coagulation is 2.9 to 3 p _H.

The amount of the acid used for coagulation of casein according to this example, an excess of 56%) of the theoretically required on for coagulation amount. The full Kaseinkoagulation is already achieved, when heated in the 100 1 skimmed and 20 ⁰ milk 160 ecm of sulfuric acid of 66 ° Be are introduced; if the acid supply is continued up to 250 ecm, the coagulated casein appears to dissolve again.

In fact, there is only an extremely fine distribution of the casein particles in the whey; even if the excess acid is further increased, the casein coagulated by the acid is not redissolved. Rather, it can be removed and separated from its whey, however large the amount of acid used for its coagulation may have been. In general, one has to adjust to a hydrogen ion concentration corresponding to a _pH value which is lower than 4.7.

Of course, the percentage of excess acid can be changed above and below the value of 56 ⁰ Zo given in the example, depending on the effects which one wishes to achieve.

All strong mineral acids such as nitric acid and sulfuric acid can be used, of course always with regard to the concentration of equivalent quantities and taking into account the Need for coagulation to be carried out with an excess of acid, as above is explained with regard to sulfuric acid.

Organic acids can also be used; however, these are less suitable as they are once because of their lower acidity and on the other hand because of their higher price per se the economy of the procedure in question.

Finally, the coagulation of the textile casein can also be done with acid mixtures, e.g. B: from two or more mineral acids, whereby the neutralization capacity of the acid mixture for 100 1 skimmed milk must also correspond to ^{the neutralization capacity of 2150 ecm sulfuric acid of 66 0 Be.}

For example, one can use 100 ^{liters of milk of 2O:} 125 com sulfuric acid of 66 ° Be and 250 ecm of concentrated nitric acid; the result is about the same as when using 25'CS ecm sulfuric acid of 66 ° Be.

One can also modify both the lactic and the sour casein of the trade so that these can be used for the production of artificial textile fibers, and that can be done at the time Insufficient acidity to coagulate lactic casein due to the addition of preferably strong mineral acid with vigorous stirring in the whey after by spontaneous fermentation Once the casein has coagulated, the acid can add to the casein after it has been removed from the whey, preferably after compression or pulverization. However, this is a cumbersome job with lactic casein. With acid casein this is Measure easier to carry out, since the excess acid can be determined more easily.

Finally, the sour whey resulting from one operation can also be used with the addition of the the amount of fresh acid required for coagulation can be used.

After the casein has been coagulated, it is heated to remove the liquid as well as to facilitate the following pressing.

With this measure, the temperatures must not exceed 65 to 66 °, because at 70 ° the coagulation of the milk protein in the whey begins and this protein, mixed with the casein in considerable quantities, would interfere with the subsequent spinning work. It is enough z. B. to gradually warm the casein in the whey up to 61 ° and then remove the liquid immediately to collect the casein. It is true that the length of time the casein remains in the 6i ^c warm whey can be extended to two and a half hours or more, but this is undesirable because staying at this temperature for too long reduces the resistance of the threads or fibers.

It has also been found beneficial to leave the casein in the whey for 1 hour to be heated to 45 °. By regulating the temperature or the heating time one can determine the viscosity grade and the density of the casein solutions affect what is better achieved by the fact that the temperature during preparation and the subsequent ripening of the alkaline casein solution is regulated. If you can in advance want to influence the viscosity and density of the alkaline casein solution, it is best to to choose the excess acid during coagulation correspondingly higher or lower.

The sour or tactical trading caseins are generally presented one or more times washed after pressing; after pressing, they are dried to get the water content that is needed after the compression is 50 to 70%, to 10 to 12%.

The textile caseins produced by the process according to the invention are retained on drying and pressing a higher percentage of whey back than the normal commercial caseins and this, to a certain extent, depending on the greater or lesser excess of acid which is present in coagulation was used. For the production of artificial textile fibers is it is permissible to remove the whey from the casein and to dry it; after pressing and subsequent ones Trituration can easily be made for the preparation of alkaline colloidal solutions be used. In this case, as will be described further below, the in The percentage of acid whey remaining in the casein is taken into account when adding the alkali will. It is appropriate that the percentage of whey after pressing 200% of the weight of dry casein does not exceed.

The casein intended for the manufacture of textile fibers should be as low as possible Fermentation preserved; if the casein has not been washed and another certain one Contains sour whey, it will remain undamaged for a few days anyway.

If, on the other hand, the casein has been washed for whatever reason, it is advisable to add suitable antiseptic or sterilizing agents to prevent fermentation which can easily enter especially during the summer months.

The following is an example of the extraction of the for the production of textile fibers or threads of suitable casein: first, a certain amount is skimmed off Milk is filled into a container with an agitator and a double bottom and double walls for the Circulation of the water that regulates the temperature during the coagulation process is required, is equipped.

The milk is brought to 20 ⁰ . A solution of 250 ecm of sulfuric acid with a specific gravity of 1.84 for every 100 l of skimmed milk is prepared in a separate container; and the acid is brought to 20 ^0th The agitator is now started to set the milk in motion and half of the prepared acid is slowly introduced into the milk while continuing to stir, preferably by means of tubes evenly distributed in the milk.

After the milk has remained in contact with the first part of the acid for about an hour, it is set in the same way add the remaining part of the prepared acid. After the addition of acid has ended you can immediately start heating to the desired temperature, preferably under further Stir, start, but you can also wait a certain time before after it has taken place Coagulation is started with the heating of the mass.

When the heating is complete, the casein is removed from the whey, it is squeezed off to make your own Reduce moisture content and pulverize it to make it easier to dissolve.

The temperature during coagulation can also be lower or slightly higher than 20 ° '.

2. The second stage of the process consists in dissolving the casein and in the Dilution and maturation of the casein solution.

Only sodium hydroxide and potassium hydroxide are suitable for making a spinnable solution. All other alkalis do not make spinnable casein solutions. In practice it is more appropriate only use sodium hydroxide as a solvent.

Small amounts of other alkalis can also be used which either directly derive from the Sodium or potassium hydroxide solution or the mixture of both can be added or the using of sodium hydroxide or potassium hydroxide, or a mixture of both previously prepared Casein solution can be added to make slight changes in the properties of the To effect casein dissolution; in doing so, however

these additives are kept within narrow limits to allow the casein solution to be spinnable does not lose.

The amount of sodium hydroxide preferably to be used to achieve one for the Manufacture of artificial textile products suitable casein solution can vary depending on the temperature that is used at the dissolution of the casein and during its ripening.

ίο It is not recommended to deviate significantly from an average temperature of 24 °, as higher temperatures, e.g. R. 35 '°', too high, the spinning process impairing viscosity and lower temperatures, z. B. below 14 ¹⁰ , cause a useless slowdown in ripening.

The production of casein solutions is explained below with the aid of a few examples.

Example A.

Use of dried casein that has not been washed after coagulation.

A certain amount of dry and ground casein is placed in a container that comes with Agitator as well as with double bottom and double walls for the circulation of the water, which is for the temperature regulation during the processes of dissolving, diluting and maturing the casein solution are required.

For every 100 dry caseins with a water content of 10%, 200 1 24 ⁰ warm water are poured, the water being evenly distributed over the casein; you can also introduce the water first and then the casein into the container. After 2 to 3 hours one leads into the. Container, with vigorous stirring, 23 1 sodium hydroxide solution with a specific gravity of 1.32 (28.83%) mixed with J 71 water which has previously been brought to 24 ⁰ ; once the mixture has become homogenous, the agitation can be slowed down and be temporarily suspended, the temperature is preferably maintained at 24 ^0th It should be noted that at. Instead of caustic soda with a specific gravity of 1.32, a corresponding amount of caustic potash can also be used. If the water content of the casein used is higher or lower than 10%, the amount of water and alkali to be added to the casein must of course be changed accordingly.

As soon as the casein has dissolved and the mass has gradually become more viscous, what is in If it happens a few hours, you start with a gradual dilution and adjust to this The viscosity of the casein solution increases during ripening. Those brought to 24 ° in advance It is advisable to add diluents gradually.

Once the casein solution has reached the desired viscosity, you can increase it further curb the viscosity by lowering the temperature somewhat.

The time required for the casein solution to dissolve and mature can be within further Boundaries are changed; because it also depends on the types of casein used and after that used during the dissolution of the casein and subsequent maturation Temperature.

The casein washed before drying is processed in the same way as the unwashed one Casein dissolved; only the alkali used is according to the amount of acid that has been removed from the casein by the washing.

Example B.

The dissolution of the undried casein, i.e. still containing sour whey, is carried out with the following Changes made:

The casein, which has been coagulated and warmed in its whey and previously collapsed, is squeezed out to the whey content preferably to not more than 200% based on the weight of the dry Caseins, to reduce and to facilitate the subsequent pulverization of the pressed casein.

Put the casein in the container described above without the addition of water and then set Sodium hydroxide solution with a specific gravity of 1.32 to which so much water was added in advance is that the liquid volume of 400 liters per 100kg dry casein is reached.

The diluents that are used for diluting the casein during its ripening are very numerous. Water is of course the cheapest and can if it is tap water or pre-purified water acts to be used as it is; distilled water offers no particular advantages. Man can also use the whey itself, which is contained in the casein of the coagulation has remained. In the latter case, the viscosity is not so high than when using water as a diluent.

The water or the whey used as a diluent can also be made weakly alkaline using a specific one Amount of caustic soda required to dissolve the casein.

If you use sour whey as a diluent without neutralizing it or only under partial neutralization or weakly acidic water, the spinnability is impaired, however, the coagulation ability of the casein solution is somewhat increased. As a diluent neutral or weakly alkaline or acidic solutions, e.g. B. from sodium lactate and sodium formate, Find use.

Solutions with a low content of certain sulfates or sodium bisulfite or the like increase this Viscosity and can therefore be used if so desired. Exercise the same effect Soapy solutions from; they can preferably also be used when desired to introduce saponified fat into the casein solution.

Sometimes it is important to add coagulation-accelerating agents such as carbon disulfide, introduce in order to contribute to a more rapid and perfect coagulation of the threads. Some of the above-mentioned diluents are already suitable, the ability to coagulate to increase the casein solution somewhat. But it is faster and more vigorous coagulation of the solution, it is preferable to include carbon disulfide in the casein solution.

For example one can take one with carbon disulfide in the presence of caustic soda Soap treated with moderate heating, which is then diluted with water, preferably a few Add hours before spinning.

In this way three effects are achieved at the same time, namely an increase in the volume of the casein solution without its viscosity reduce, an increase in the coagulability and a greater softness of the obtained Textile products. Other substances, such as glycerine, can also serve the same purpose, but always under treatment with carbon disulfide.

On the other hand, if you don't want to add fats to the casein solution, you can use caustic soda treat with carbon disulfide and use this solution instead of the previously discussed solution.

The carbon disulfide can also preferably in the form of vapors directly into the Casein solution can be introduced or in any other suitable for the intended purpose Shape.

The alkaline casein solutions can, when ripening, solutions of alkaline silicates, preferably Sodium or potassium silicates, can be added. The casein solutions are preferably used once or filtered several times before being spun.

3. The third step in the process is spinning.

The same machines can be used for this as they are used for the production of viscose rayon. The spinning speed can be 60 to 120 m / min. Since the coagulation of threads formed from casein solutions is slower than that of those made of viscose, the acidity of the coagulation bath must be greater and practically almost twice as great as that customary for viscose precipitation baths. The temperature must also be higher and can be between 48 and 58 °, but in general one works at 52 to 53 ⁰ .

It is advisable to have a lower acidity and, if appropriate, also a lower temperature of the bath, but to increase the diving length.

The coagulation baths can, for example, have the following composition:

_π . . .

Example a

A solution is made that is 140 ecm Contains sulfuric acid with a specific gravity of 1.84 and 400 g of sodium sulphate per liter. This Aluminum salts, preferably aluminum sulfate or potassium alum, can also be added to the solution small amounts of tin salts, e.g. B. tin acetate can be useful.

Example b

A solution is made that is 150 ecm Sulfuric acid with a specific gravity of 1.84, 150 Contains up to 220 g aluminum sulfate and 75 g sodium chloride per liter. The amount of additives and the ratio of aluminum sulfate to sodium chloride can be determined depending on the intended Effect change taking into account the fact that the aluminum salts harden the Fadens cause immediately after coagulation and that the sodium chloride has this effect Aluminum salts supported. When preparing this solution, care must be taken that none excessive heating takes place in order to avoid that hypochlorous acid is formed.

If the casein solution contains carbon disulfide, it is more expedient to follow the instructions given under a Bathroom to use. The fourth operation for the production of textile fibers according to the invention ■ consists in the aftertreatment of the threads or fibers obtained and in their deacidification.

The threads or fibers obtained are strongly acidic after the coagulation process, you have to they therefore deacidify, which is done in running water; a few hours of laundry are sufficient, if it is staple fibers, 15 to 14 hours are required if the threads are wound on spools.

However, washing must not be carried out immediately after coagulation, because dissolve the freshly coagulated threads in water; the threads must therefore be suitable beforehand Subject to treatments to make them insoluble in water.

For this purpose, aqueous solutions of formaldehyde are used, preferably below Addition of sodium chloride. It must be taken into account that one containing less than 10% sodium chloride aqueous solution exerts a swelling effect on the casein fibers, while a more than 10% containing solution has a shrinking effect.

It is advantageous for solutions of increasing concentration to act on the thread material one after the other allow.

These aftertreatment baths can be weakly acidified, preferably with sulfuric acid happens; in and of itself, the continuous introduction of acidic fibers into the aftertreatment bath is already effective a continuous increase in its acidity, so that after achieving the desired Acidity the excess acidity of the bath can be neutralized from time to time even with alkali got to. If it is not spun directly on bobbins or in a pot, as it is in 'production of staple fibers, it is appropriate to remove the fibers immediately after leaving

to introduce the coagulation bath into a bath consisting of a sodium chloride containing more than 10% aqueous solution consists; small amounts of acid and aluminum salts are added to this solution to, so · it is achieved, even without formaldehyde, that the fibers are better separated from one another separate as if they were first placed in an empty container and there for a while Time remains before they are fed to the aftertreatment baths.

Casein fibers suffer, if they have not been applied to spools, in the aftertreatment baths a sharp shortening, especially if the fibers are immediately after the coagulation can be immersed in a highly concentrated bath. On the other hand, if one dives such loose ones Fibers first in a weakly concentrated bath, this will shorten the fibers largely prevented. Do you want a shortening

so completely prevent the threads After coagulation, first reel it and immerse it in a weak bath in this state and then, if necessary, bring into baths with increasing concentration until the average concentration is reached. Now you can cut the threads to the desired length and feed them to the subsequent baths in a loose state. In this way, evenly crimped and less shrunk fibers are obtained.

After hardening, the threads are washed in running water • until they are completely deacidified, if necessary, they can then be treated again with a neutral hardening bath will.

The textile fibers or threads produced in the manner described above are useful still to be treated with an emollient bath.

Aqueous solutions of Turkish red oils, also mixed with soaps, are suitable for this purpose. emulsified mineral oils, glycerine, etc. or with oils emulsified by known processes or Fats.

The treatment in the soaking bath is preferably carried out before drying is complete Deacidification of the structures; the bath temperature can be between 45 and 60 °. Of course, this treatment is unnecessary if the softening agent is used before spinning have been introduced into the Kaseki solution.

Claims (8)

Patent claims: i. Method of making kitnstliehen Threads or fibers made from milk protein, characterized in that casein in alkali like sodium hydroxide solution, is dissolved at 14 to 34 °, with the casein at room temperature from skimmed milk by adding an excess of acid that exceeds the theoretical amount is obtained, then the alkaline casein solution is allowed to mature at temperatures between 14 and 34 °, after which the matured solution, possibly after adding plasticizers, contained in acidic salts - _ the baths is deformed into threads and then the threads with if necessary weakly acidic salts in the amount necessary to avoid thread damage and deswelling baths containing hardening agents, preferably formaldehyde, washed and finished. 2. The method according to claim 1, characterized in that that casein coagulated with acid from milk and then treated with an excess of acid as a starting material is used. 3. The method according to claim 1 or 2, characterized in that 'casein is used as the starting material, which has been treated with such an excess of acid over the amount required for the acidic coagulation of casein in skimmed milk that a hydrogen ion concentration is achieved, which is just is below the isoelectrical point of the casein of pn4.6 . 4. The method according to any one of the preceding claims, characterized in that casein is used as a starting material during or after coagulation with antiseptic 'or sterilizing agents. 5. The method according to any one of the preceding claims, characterized in that 231 sodium hydroxide solution of 35 ¹⁰ Be or the corresponding amount of potassium hydroxide solution with ₌ einör tolerance of 20% above and below the specified amount in addition to water as a solvent for 100 kg of ground, dry casein .100 with ιό! ° / ο moisture content is used. 6. The method according to claims 1 to 5, characterized in that a spinning solution is used which, when ripening, is a diluent, such as alkali neutralized or unneutralized whey, solutions of Sodium lactate, sodium formate, sodium bisulphate or soap solutions have been added are. 7. The method according to claims 1 to 6, characterized in that a spinning solution is used, the coagulation accelerating agent such as carbon disulfide, optionally with solubilizers such as soap or glycerine have been added. 8. The method according to claims 1 to 7, characterized in that the coagulation of the formed casein solution takes place in acidic, salt-containing baths which ^{contain not less than 91 sulfuric acid from 66 0} Be to 100 l bath and optionally formaldehyde. 9. The method according to claims 1 to 8, characterized in that the treatment ■ in the deswelling baths in stages, preferably is carried out with increasing concentration. 5334 8. S3