DE1469067A1 - Process for the production of synthetic fabric fibers - Google Patents

Description

The Dow Chemical Company, Midland, Michigan, V.St.A.

Process for the production of synthetic fabric fibers

The invention relates to synthetic fabric fibers and Process for their manufacture.

It is well known that most synthetic fabric fibers must be stretched or oriented during their manufacture. Depending on the crystal properties and / or the molecular configuration, the degree of stretching and the stretching conditions can be very different. In some cases only a very small stretch is required} in other cases the lasers can be stretched by as much as $ 1300-2000. The stretching can take place in the cold or hot state, in air, water or in any other gaseous or liquid medium. In all cases, the aim is to orient the crystallites or polymer molecules to a certain extent parallel to the fiber axis. This alignment is necessary in order to take advantage of the fibers

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inherent tensile properties are obtained.

When wet spinning of pasern becomes common a solution of the polymer in a solvent is spun into a liquid which does not dissolve the polymer, thereby causing the deposition of a polymeric thread. The polymer solvent is then deposited from the Polymer is washed out or leached out and mostly by an inert liquid, which is often water is replaced. The thread made by this process is usually in a gel state, i.e., it is strongly swollen and the liquid which does not dissolve the polymer or which is inert, e.g. water, can be increased 4 to 6 times Amount of polymer included. The gel thread is usually washed, stretched, and finally to be destroyed the gel structure dried.

The stretching or orientation of wet-spun acrylonitrile polymer fibers is carried out by known processes usually at temperatures between 70 and 110 ^° C. in the presence of moisture. Usually high draw ratios are only possible at the higher temperatures if excessive thread breakage is to be avoided; Draw ratios of about 10: 1 and above are usually required in making fibers with a satisfactory combination of physical properties. The total elongation given to the fiber is the fiber

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in one stage or in several successive stages Levels have been awarded.

According to the invention a process for the production of synthetic fabric fibers with improved properties is provided proposed in which a dispersed in an aqueous or in a water-miscible solvent fiber-producing polymer is wet-spun. This procedure also includes the following stages! (1) Deposition a thread ^ (2) washing, (3) stretching, (4) heating and (5) drying or treating the gel thread to produce a finished fiber product. At an essential stage of the method of the invention, the gel thread of a structuring and setting treatment (structurizing and setting treatment) prior to the treatment stage which the gel thread is converted into the finished fiber product.

The substantially non-stretched gel filament may be patterned by a method in which it with an aqueous medium at temperatures of 50 - 55 and at temperatures of 80 ⁰ G preferably - 75 ⁰ C is brought into contact. Until the structuring treatment, the gel thread can be kept in a non-stretched state or, advantageously, can be stretched to lengths which are 1.5 times the original length. The structured gel thread can be stretched while it is in contact with the aqueous medium used for structuring or by cooling

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to a temperature below the structuring temperature can be set in its structure (structure-set).

As stated above, the Process of the invention produced fabric fibers from fiber-producing polymers obtained from dispersions in aqueous or water-miscible solvents are spinnable. As a fiber-producing polymer can be advantageous an acrylonitrile polymer can be used, the at least 80 wt .- $ misohpolymerized acrylonitrile contains. Good results are also obtained when polyacrylonitrile is used as the fiber-producing polymer. In the method of the invention are particular got good results with gel threads made from a aqueous salt solution such as zinc chloride solution. The polymer dispersion is preferred also spun into a precipitation solution that has the same salt constituents as the polymer dispersion contains.

The best results are obtained when the gel thread obtained by wet spinning is a hydrogel thread, which after washing with water contains up to 5 1/2 parts by weight of water per part by weight of polymer and which contains up to 1.5 times the length of the original length before it is subjected to the structuring and setting treatment.

It is believed that the gel by the invention proposed treatment a special morphological

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Structure is given to which the new improved and "special properties of the fiber obtained are attributed · The change in structure can be determined if from that treated according to the invention Gel a typical tensile strain curve is recorded.

The setting of the structure can, as indicated above, be carried out by one of two methods: Temperature of 50 - 8O ⁰ O is brought into contact. Any sustained stretching is sufficient to set the gel. A stretch ratio of stretched length to unstretched length of 1.1: 1 can be used, but ratios of 2: 1 to 8: 1 are more advantageous. (2) The thread may be made of the Gelstrukturierungsmedium which at 50 - 80 ^0C and preferably at 55 - 75 ° C is maintained, removed and cooled to a temperature below that at which the Gelstrukturierungsmedium has been held. The aqueous gel structuring medium preferably consists essentially of water, but can also contain other water-miscible materials that are inert towards the gel thread or other water-miscible or ice-dispersible auxiliaries with which the gel is to be impregnated.

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Hach performing each process, the fiber is then in a subsequent-on 80 -, preferably G 110 ⁰ 90 - 110 ⁰ C and advantageously at 95-100 ⁰ O heated medium stretched. In this case, at 80-110 ⁰ C, a single stretching are carried out, or it can be in a sequential series of steps at 80-110 ⁰ C are stretched. Either a liquid aqueous bath or a gaseous or vaporous atmosphere, such as saturated water vapor, can be used as the drawing medium.

In the practical implementation of the proposed method, the. Gel structure imparted to gel threads or the change in the gel structure is irreversibly determined, provided that the gel structure is determined by one of the methods described above. For example, if a gel filament treated at 70 ⁰ C and is then cooled to a temperature of 60 ⁰ C or below, and finally stretched, the gel structure has the characteristics of the performed at 70 ⁰ C temperature treatment. The thread would have the same properties if it had been stretched ^{at 70 ° C. during the temperature treatment.} In contrast, if a fiber at 70 ⁰ C and then heated to 80 ⁰ C and is stretched, the effects of the treatment are extinguished at 70 ° C and outweigh the conferred in the treatment of 8O ⁰ C Properties, In all cases, by the top Temperature at which the gel structure is imparted, the properties of the gel thread and thus the physical

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Properties of the resulting "and ultimately converted fabric fiber" are determined, provided that the structure has been "fixed" at this temperature or at a lower temperature ("se # 9. If a treatment or gel structuring temperature below 50 ⁰ C is used,
the beings are not given any characteristics that improve their physical properties. Similarly, but with different end results, are at one temperature
above 8O ⁰ C does not reach the improvements in the treatment at a temperature of 50 - 8O ⁰ C can be achieved, although this structure is obtained, which affects the physical properties. It should
be noted that the advantages of the invention will not be obtained when the Greifäden after the slack by an aqueous medium having a temperature 50-80 ⁰ G
be brought to a higher temperature without a setting step. The treatment must either by cooling to a slightly lower temperature or
interrupted by stretching before the threads are exposed to a higher temperature *

As stated above, the characteristic change in the gel structure caused by the heat treatment at ^ SO - .80 ⁰ C can be determined by determining a tensile strain curve
obtained in a tensile strength test in which the results are recorded simultaneously with, a non-stretched gel thread, (Often

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the gel threads after balling together in a Temperature of 20 - 25 ° C stretched up to 1.4: 1, so that it is sufficient for the subsequent processing Have strength, but for all practical purposes these threads are considered to be undrawn.)

1 shows a typical train-strain curve is illustrated which has been obtained with a non-stretched, naßversponnenen Polyacrylsäurenitrilgelfaden, in a water bath at 20 - 25 ⁰ C is treated.

In Figure 2 jbt a typical tensile strain curve is shown, those in a non-stretched one. Gel thread aue the the same sample has been obtained as that used for FIG. 1, but in a water bath for the one according to the invention proposed temperature has been treated.

When the curves shown in FIGS. 1 and 2 are compared, it can be seen that an unusual peak value ("Peaking") the initial curve and a subsequent drop to the normal tensile-strain curve for is characteristic of the gel threads made by the method of the invention. This peak value and the curve shown in FIG. 1 does not have a return to the more usual curve shape. Those made from such gel threads produced fibers having a tensile elongation curve with such a peak value compared to Fibers made from gel threads with a tensile strain curve similar to that shown in FIG.

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Lich improved physical properties.

The fibers produced by the process of the invention have a significantly improved toughness, Yield strength, an improved modulus and improved transverse properties (originally: "transverse properties") · A measure for the improved transverse properties are the improved Edging properties of the fibers in the moist state (wet fibrillation properties). It is also common to impregnate the gel threads (or hydrogel threads) with a dyeing aid expedient, whereby the proposed method to produce the same colorability compared to the conventional Drawing process required amount of the dyeing aid is reduced. The impregnation is done in the same way improved with other beneficial tools.

The known aqueous salt solvents, which are used for the various fiber-producing polymers and Can be used especially for acrylonitrile polymers, contain zinc chloride, the various thiocyanates, so of calcium, lithium bromide, salt mixtures of the so-called "lyotropic" series and other known means. Zinc chloride can most advantageously as a sol or at least as the main dissolved salt in that used for the polymer Spinning solvents can be used. In such cases the aqueous solution of zinc chloride in the spinning solution can have a concentration of 55-65 and preferably 60 wt .- ^ based on the weight of the aqueous solution. if

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Such aqueous zinc chloride spinning solutions are used, the concentration of zinc chloride in the proportion of the Liquid in the spinning zone at a polymer-non-dissolving, precipitating concentration of at least 25% by weight held; A concentration of 30 - 50 is advantageous and preferably from 40 to 45 wt .- ^ used. When spinning of acrylonitrile polymers in such aqueous zinc chloride solutions, in which the fresh, wet-spun Polymer is usually obtained in the form of a hydrogel, is usually such a spinning solution to be squeezed out used, which is between 4 and 20 wt .- ^ of the dissolved polymer, more advantageous 6-15 Gew .- ^ of the dissolved polymer and - especially when polyacrylic acid nitrile fibers are produced are - preferably 8.5 - 11.5 wt .- ^ of fiber-producing contains polymeric solids in the spinning solution.

Aqueous zinc chloride spinning solutions of the fiberising Acrylsäurenitrilpolymerisate be at a spinning temperature of 0 - 50 ⁰ C, preferably at a temperature of 10 - pressed 30 ⁰ C in an aqueous Zinkchloridfällflüssigkeit that at a precipitation temperature of 0 - held 20 ⁰ C - 30 ° and preferably from 10 will. Thoroughly washed acrylonitrile polymer hydrogel fibers usually contain no more than 5 1/2 parts by weight of water (which includes residual associated, external or external water) per part by weight of the dry polymer contained therein. Washed

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Acrylic acid nitrile polymer hydrogel fibers more often contain about 2 and usually about 3-4 parts by weight of water per part by weight of polymer.

Homopolymers Acjjijjau ^ ßnl ± xilg.elläden or polymers Gel threads made from copolymers of acrylonitrile with one or more other ethylenically unsaturated Monomers which can be copolymerized with aoryl acid nitrile have been produced, which are present in the polymer molecule at least 80 wt .- ^ copolymerized acrylonitrile can be treated successfully according to the method proposed according to the invention. Examples for others monomeric materials which can advantageously be used with acrylonitrile in the practice of the invention, sine? Allyl alcohol, vinyl acetate, acrylic acid amide, methacrylic acid amide, Methyl acrylate, 2-vinylpyridine, dimethylaminoäthylacryiat, Methacrylic acid nitrile, acrylic acid, itaconic acid, vinyl acetic acid, ethyl acrylate, fumaric acid nitrile, 2-vinyl-5-ethylpyridine, Ethylenesulphonic acid and its alkali salts, allylsulphonic acid and its alkali salts, vinyl lactams, such as Vinyl caprolactam and vinyl piperidine, vinyl benzene sulfonic acid and their salts, vinylbenzene trimethylammonium chloride, vinyl methyl ether, N-acryloyl taurine and its salts, 2-aminoethyl methacrylate hydrochloride, 2-sulfoethyl acrylate, X-sulfopropyl acrylate, Maleic anhydride and mixtures thereof.

The properties of certain other modified acrylonitrile polymer fibers can also be determined according to the

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Processes of the invention are improved, which particularly include those consisting essentially of an acrylonitrile polymer matrix and especially consist of polyacrylic acid nitrile, in which intimately and for permanent or practically for permanently smaller proportions of 1 or 5 and up to 20 wt .- ^ or more, based on the weight the polymer composition, advantageous additives or ingredients have been incorporated, which a desired Serve purpose and deliver the beneficial result. These polymer masses are often called "acrylic resin alloys" designated. Such beneficial additives are usually used as coloring auxiliaries. These funds can be beneficial from polymerizing products containing nitrogen Monomers or mixtures of monomers exist, e.g. from the various ΙΓ-vinyl lactams and the ones used with them Products such as IT-vinyl-2-morpholinones, N-vinyl- -2-oxazolidones, and from certain H-vinyl-N-methylalkylsulfonamides.

The "acrylic resin alloy" can thus consist of a Aorylsäurenitrilpolymerisatgrundmasse exist, which by. Graft or block copolymerization of acrylonitrile or an acrylonitrile-containing monomer mixture to a smaller proportion of an already preformed polymer has been prepared from any of the specified nitrogen-containing monomers or monomer mixture has been obtained * The polymer can

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also from a graft copolymer product of any of the specified nitrogen-containing monomers an already pre-trained and preferably already processed Acrylic acid nitrile polymer exist.

The "acrylic resin alloy" fiber can also consist of an acrylonitrile polymer composition, in which a smaller proportion of a polymer product from one of the specified nitrogen-containing monomers or
Monomer mixtures as dyeing auxiliaries have been incorporated permanently through physical homogeneous blending «, The physical blending can take place before the spinning of the fiber-producing solution, whereby in cash spinning the agent can also be incorporated into the hydrogel thread before the hydrogel dries irreversibly»

The auxiliary or the advantageous component in the "aeryl resin alloy" fiber can be a homopolymer or a straight-chain copolymer of one of the specified nitrogen-containing monomers with other mono- or polyfunctional monomers. Aids of this type are essentially made from acrylonitrile existing polymer is usually mixed physically homogeneously so that the desired intimate incorporation of the Auxiliary means and the "alloy * *" created in the fiber effect "can be ensured. In the case of physical Mixing agents and additives which are graft copolymers can also be used in the same way

and which consist of various monomers, which on polymer substrates from one of the specified nitrogen containing monomers, such as poly-IT-vinyllactarn-, poly-N-vinyl-2-oxazolidone- or poly-N-vinyl-N-methylalkylsulfonamide pads, have been graft copolymerized · Graft copolymer additives, which from one of the specified or a closely related nitrogen-containing monomer (such as from IT-Vinyllaetammonomeren, N-Vinyl-2-oxazolidonraonomeren and N-vinyl-N-methylalkylsulfonamide monomers) exist and have been graft copolymerized on other fractional polymer substrates also suitable and can be used.

The polymer products from the nitrogen-containing, functional monomers should be used as an aid in the "acrylic resin alloy" fibers in one Amount present, which is about 5-15 wt .- ^ o, based on the Weight of the "acrylic resin alloy" mass. As a polymeric auxiliary that essentially consists of Acrylonitrile existing polymer base is mixed homogeneously in the "acrylic resin alloy" mass advantageously a ^ N-vinyllaciram homopolymer, such as poly-N-vinylpyrrolidone (also known as poly-N-vinyl-2-pyrrolidone or poly-ir-vinyl-2-pyrrolidone), Poly-N-vinylcaprolaetam or a related poly-Kfvinyl-3-morpholinone, an IT-vinyl-2-oxazolidone homopolymer or a poly-IT-vinyl-5-methyl-2-oxazolidone or a

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II-vinylmethylalkylsulfonamide homopolymer, such as a K-vinyl-N-methylmethylsulfonamide homopolymer, can be used. If "aeryl resin alloy" products produced by physical mixing are used in which the auxiliary or the additive consists of a copolymer or graft copolymer product of the specified nitrogen-containing monomers, polymeric auxiliaries should preferably be used which contain at least 50 or even 80 wt. f6 or more of the specified components obtained from the nitrogen-containing monomers.
example 1

To illustrate the applicability of the invention within half a wide range of conditions were Fibers wet spun under very different conditions, which are then conditioned according to the process of the invention or were not conditioned for comparison.

A spinning solution was prepared from polyacrylonitrile with an average molecular weight between about 30,000 and 35,000 existed in a aqueous solution of 60 wt .- $ zinc chloride had been dissolved. The total amount of polymer solids in the spinning solution was about 10 wt .- ^ based on the weight of the Solution. When spinning the store there were two different ones Pällbäder uses j, · - · ■ ·> .: ■ ·

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An aqueous bath containing 47 wt .- ^ zinc chloride contained and was maintained at a temperature of 24 ⁰ C _o The spun filaments in this bath were designated sample "A"".

An aqueous bath containing 43.4 wt .- ^ containing zinc chloride and maintained at a temperature of 11 ⁰ G · The spun filaments in this bath were designated sample "B".

The spinning solution was pressed into each of the felling baths, whereupon the precipitated gel threads were washed ύοώ. practically freed of the remaining salt, stretched to about 1.45 t 1 (ratio of stretched length to original length) at room temperature and then collected. The filaments of sample ¹¹ B "were denser than those of sample ¹¹ A".

Individual gel threads from each sample "A ^M and ¹¹ B" were selected at random and subjected to a tensile strength test at room temperature. The gel threads were kept under ethylene glycol during the experiment to prevent the gel from drying out. During the tensile strength test, the tensile elongation curves were recorded automatically, which is a generally known and recognized method for determining the physical properties of fibers and fibers. 5 threads were examined from each sample. In Figure 3, a typical tensile strain curve is shown

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which was obtained with the gel threads of sample "A". Figure 4 shows in the same way a tension-elongation curve, was obtained when examining gel threads of sample "B" has been·

Others were randomly selected from Sample "B" and subjected to tensile strength testing the tensile strain curves in the manner indicated above were determined, however, each thread before the examination in a Viasser bath, each on a different Temperature was maintained, brought for a constant period of time, cooled to room temperature and only then examined · The gel threads underwent a gel structuring treatment subjected, with some of the threads in the proposed invention and other threads in a temperature outside this range were treated in Figures 5 to 10 typical curves are shown, which are characteristic of the treated and examined threads. Again, there were 5 sutures from each sample examined. The results obtained are shown in Table I. summarized·

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Table I.

figure OO
ο 5 sample Temperature of
Gel structuring
Water bath (__C) toughness
(ä) strain
W) Stretch limit
(β) module
(*) (O
00 6th ¹¹ B ₁ » 50 7.0 410 4.2 2.0 ο 7th "B ₂ " 52 7.6 400 5.8 1.0 to
W. 8th "B ₅ " 62 7.6 400 6.4 0.8 9
10 "B ₄ " 72 8.4 170 11.0 2.0 3 "B _c "
P.
"B ₆ " £ fi £
82
100 11.6
12.0 18th
10 13.2
12.0 2.0
3.1 4th "A" about 20 3.8. 440 2.2 0.25 "B" about 20 6.7 420 4.3 2.5

-es cn co ο

The curves shown in Figures 3 and 4 (samples "A" and ¹¹ B ") that reflect the physical properties of ffelfäden, which have been treated prior to the study at about 2O ⁰ C, and in Figure 5 (Sample B ^ ) curve shown, which reproduces the physical properties of gel threads that have ^{been treated at 50 0} C, show no peak value in the course of the initial curve, as shown in Figures 6-8 (samples "B ₂ ", "B," and "B curves shown ₄ ¹¹⁾ that reflect the physical properties of gel filaments, which have been treated at a temperature of 52 72 C ^0. Curves in Figures 9 and 10 (samples "Bc" and "Bg") illustrated that reflect the physical properties of gel filaments, which have been treated with 82 and 10O ⁰ C, while indicating the initial curve a peak value, however, later not the slope characteristic of the curves shown in Figures 6-8.

The summary of physical properties given in Table I shows that the most beneficial Combination of physical properties and the greatest improvement in physical properties those "belt threads, which are produced according to the method of Invention have been treated and which are consequently characterized by an abnormal peak value - in their.Jug strain curves which then resume normal inclination.

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Same excellent results have been obtained when the gel filaments of Sample "A" in water baths in the same manner as the gel filaments of Sample ¹¹ B "were treated. The physical properties of these filaments were significantly improved by treatment according to the method of the invention, wherein also these threads showed the characteristic peak value in their tension-elongation curves «

Example 2

Gel threads from sample ¹¹ B "of Example 1 were treated for 1 minute and 10 minutes in a water bath at 65 ⁰ O, cooled to room temperature and then subjected to the tensile strength test. The results obtained are given in Table II"

! Tables

Handling

duration toughness elongation yield point modulus

(Minutes) (gj (#) (g) (g)

1 7.2 290 5.8 3.0

10 7.8 350 7.4 2.0

Although the results given in Table II were for the longer Treatment duration are slightly better, the treatment duration is not particularly special for all practical purposes essential, because significant improvements can be obtained if the treatment lasts only a few seconds, i.e. 5 - 10 seconds.

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example 3

Polyacrylonitrile fibers were spun from the spinning solution described in Example 1. They were ^{deposited in an aqueous solution of 44.5% by weight of zinc chloride at 12 °} C., freed from the remaining salt by washing, stretched to 1.45: 1 at room temperature and passed 100 ⁰ C - then by two aqueous baths having a temperature of 95th The pads were stretched to 3.4 s 1 in the first of the two baths and to 2.4: 1 in the second bath. The total aspect ratio was approximately 11.88: 1 (extended length to original length). The gel fibers were about 7 minutes for the purpose of producing characteristic hydrophobic fabric fibers irreversibly dried at 140 ⁰ C. The finished filaments, designated Sample ⁿ G ⁿ , were then examined for their physical properties, which included the tendency of the filaments to split or detach from the fiber surface, commonly referred to as wet piping.

Two further Paser samples, namely sample "D" and ^M E ", were produced by the same method as sample" C ", except that the conditions of the hot-wet stretching were adapted to the treatment conditions proposed according to the invention. was passed through an aqueous bath with a temperature of 69 ⁰ C and stretched in the bath to 5.39: 1, whereupon the Pädens passed through two aqueous baths with a temperature of 95-100 ⁰ C and in the first

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Bath stretched to 1.35: 1 and in the second bath to 1.19 J 1 became. The total aspect ratio of Sample "D" was about 12.5: 1.

The sample ¹¹ E "was in an aqueous bath at a temperature of 67 ° C to 5.16: 1 and then in an aqueous bath with a temperature of 95 - 10O ⁰ C to 1.32 ι 1 stretched the total stretching of the sample. "E" was about 10: The physical properties as well as the tendency to graining in the wet state of the samples "D" and "E" were determined.

For comparison, fibers were also produced by the method described for sample "D", but the fibers were stretched to 5.3: 1 in the hot state ^{in an aqueous bath at a temperature of 67 0 O, but no longer stretched at 95 100 G} became. This sample was named Sample "P". The total aspect ratio of Sample "P" was about 8: 1.

The results obtained with these four samples are given in Table III.

T abe 1 1 e III

sample toughness
g / denier strain Stretch limit
g / denier module "C" 4.2 30th 1.10 45 - 5.8 31 1.33 60 "E" 5.0 34 1.28 64 up rt 2.9 34 1.13 42.

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As mentioned above, the resistance of samples "0", ¹¹ D "and" E "to fibers in the wet state was also determined Samples of the fibers were cut to staple lengths of about 1.3 cm and then 200 mg samples were weighed for the testing procedure.

After the samples were cut and weighed, the flow time for 1 liter of water was determined Cushions made from this material are intended. The fiber pad was made by passing through a cylinder with a diameter 1.9 cm and a length of 7 »6 cm, the one sieve bottom and the weighed sieve cover showed that water was poured by passing 300 ecm of water through it three times the device created a uniform pad of fiber on the screen.

The cylinder containing the sample was then attached to the bottom of a container holding the water for the flow through experiment whereupon the flow time for 1 liter of water to flow through the sample was determined with a stop watch wasο

After determining the initial flow-through time, the sample can be placed in the "Waring" mixer. The sample was washed out of the cylinder and a sufficient amount of water was added to make it up to 100 ecm. In the standardized test procedure, 100 ecm of water were used and the mixture was kept for 10 minutes at

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a power consumption of the mixing device of 75 watts mixed in the device. After this treatment was after the above-described method again measured the flow time, with the percentage change in the flow time represents the test result. This investigation method is based on the fact that the Paser cushion is all the more dense and therefore the greater the flow resistance when flowing through is obtained by water, the more frayed the fibers have been.

The resistance to defibration of the samples "D" and "E" in the wet state was compared to that Resistance strength of sample "C" has been improved by 2 and 4 times, respectively.

For further explanation of the advantages of the invention, a sample was prepared according to the procedure described for sample ¹¹ C "method in which poly-IT-vinyl-2-pyrrolidone in the hot stretching baths in the Hydrogelfäden wurdej impregnated thereby Wirden about 7 # Poly-H-vinyl -2-pyrrolidone, based on the weight of the dry fiber, is required if the fiber has been dyed with 2 # "Calcodur Pink2BL" (Color Index Direct Red 75) to achieve a reflection value of 21. In contrast, if the poly-if-vinyl -2-pyrrolidone were brought into the hot streok baths and the pads were treated according to the procedure described for sample "D", only 3.48 $> poly-N-vinyl-2-pyrrolidone were required to achieve a reflectance value of 21.

The coloring with "Oalcodur Pink 2 BL" was after a conventional method performed in which the Paserprobe

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—Ίο—

in the dye-off bath containing the dye in an amount equal to $ 2 by weight of the fiber, boiling for 1 hour. The Färbstoffbad also contained sodium sulfate in a 15 $> of the fiber weight corresponding amount has been wherein a weight ratio of bath used for fiber of 30% 1 "After dyeing, the fiber was rinsed thoroughly with water and 20 minutes at 80 ⁰ C dried. The dye uptake of the Oalcodur Pink 2BI dyed fiber was then determined spectrophotometrically by measuring the amount of monochromatic light having a wavelength of 520 mti from a standard source reflected from the dyed sample. A corresponding numerical value was obtained on an arbitrarily fixed scale from 0-100. This value represents the relative comparative value of the amount of light reflected by a standard white brick reflector which, when extrapolating from the 0-100 scale, had a reflectance value of 316. Lower reflection values are a measure of the better dye absorption capacity of a fiber. In the case of acrylonitrile polymer fibers dyed with 2 <fo "Oalcodur Pink 2BL", for example, a reflection value in the order of magnitude of 20-50 is usually regarded as indicative of such a dye absorption capacity that easily meets and even exceeds the mostly strict practical requirements.

Excellent results comparable to those given above are also obtained when others Acrylic acid nitrile polymer gel fibers, to which acrylic acid

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nitrile copolymers and "acrylic resin alloys" are treated according to the method of the invention "

Claims (14)

Patent claims: 1. A process for the production of synthetic fabric fibers with improved properties, in which a fiber-producing polymer dispersed or dissolved in an aqueous or water-miscible solvent is wet-spun, a gel thread is precipitated, the gel thread is washed, stretched, heated and dried or dried to produce a finished fiber is treated, characterized in that the gel thread, prior to the treatment in which the gel thread is converted into a finished fiber product, is subjected to a structuring treatment and a treatment which defines this TStrurab * will. 2. The method according to claim 1, characterized in that the practically unstretched gel thread is structured by bringing it into contact with an aqueous medium kept ^{at a temperature of 50-8O 0 C «} 3 · The method of claim 1 or 2, characterized in that the substantially non-stretched gel filament by contacting with an aqueous, on a! Temperature of 55-75 ⁰ C held medium structured -is. 4. The method according to any one of claims 1-3, characterized in that the gel thread before the structuring 809810/1213 action is pre-stretched to 1.5 times the original length. 5. The method according to any one of claims 1-4 »characterized in that the structure of the structured gel thread by stretching while doing the structuring aqueous medium is in contact. 6. The method according to any one of claims 1-5, characterized in that the structure of the structured gel thread by cooling to a temperature below the structuring temperature is determined. 7. The method according to any one of claims .1.-6, characterized characterized in that the fiber-producing polymer dispersed in the solvent is an acrylonitrile polymer is at least 80% by weight copolymerized acrylonitrile contains. 8. The method according to any one of claims 1-7, characterized in that the dispersed in the solvent fiber-producing polymer is polyaoryl nitrile. 9 · The method according to any one of claims 1-8, characterized characterized in that the acrylonitrile polymer has been spun from an aqueous salt solution, 10. The method according to any one of claims 1-9, characterized in that the aqueous salt solvent in which the fiber-producing polymer is dispersed, is a solution of zinc chloride. 11. The method according to any one of claims 1-10, characterized 80 9810/1213 characterized in that the polymer dispersion in a precipitation solution is spun, which contains the same salt components that are present in the polymer dispersion 12. The method according to any one of claims 1-11, characterized characterized in that the precipitated gel thread is a hydrogel thread. 13 · Method according to one of claims 1 - 12, characterized characterized in that the gel thread prior to structuring and fixation treatment is stretched up to 1.5 s -1. 14. Process for the wet spinning of acrylonitrile polymer fibers which have been produced from fiber-forming acrylonitrile polymers which have at least about 80% by weight polymerized in the polymer molecule of acrylonitrile and a corresponding composition of another mispolymerized, ethylenically unsaturated monomer which can be copolymerized with acrylonitrile, contain, characterized in that the practically non-stretched aoryl nitrile polymer gel fibers ^{are brought into contact with an aqueous medium maintained at a temperature of 50-80 0} O, the gel structure that has been given to the aeryl acid nitrile polymer gel fibers by this contact is established and then the Gel fibers are stretched while they are exposed to a medium heated to ^{80-110 0 C «.} 809810/1213