DE1669501A1 - Polynose fibers and processes for their manufacture - Google Patents

Description

The invention "relates to improved polynosis fibers and a Process for their manufacture.

Recently, many processes have been proposed for the production of polynose fibers having excellent properties by extruding a viscose having a high "value into a formaldehyde-containing coagulating or precipitating bath and basin of the filaments formed in a hot, dilute acid bath (second bath).

If the filaments formed in the precipitation bath containing formaldehyde are used in the second bath at a relatively low temperature and at very low tensions, such as

009831/1674 ./.

BAD ORiOtNAL

Ο »3 g / d or less, stretched and then in a third, watery bath relaxes, so curled polynosis

fibers are obtained.

Furthermore, the threads drawn from the formaldehyde-containing precipitation bath have a high degree of stretchability, which is why Fibers with high tenacity, high modulus of hate and high water and alkali resistance are obtained, if they are strongly stretched in the second bath at relatively high temperatures.

The methods given above are described, for example, in U.S. Patents 2,937,070, 3,107,970 and 3,226,461, British patents 910 878, 993 786 and 1 027 153, French patents 1 266 492, 80 314/1 266 492, 1 3O2 294 and 1 351 736, as well as the Belgian patents 602 660, 608 811 and 626 075.

In general, fibers obtained using a formaldehyde-containing precipitation bath have many the excellent properties noted above. On the other hand, however, they have insufficient ductility and dyeability as well as insufficient knot tenacity, etc. Furthermore, fibers that in the second bath have been stretched to a great extent, in particular poor fray resistance.

00Ü31 / U74

In order to overcome these disadvantages, the Belgian patent specification 626 075 proposes a method in which the fibers are swollen by treatment with an aqueous alkali solution, for example a sodium hydroxide solution. However, this method leads to a decrease in the toughness of the fibers at the same time and is unsuitable for improving the fiberization resistance, which is one of the important properties. Furthermore, in this method, a large amount of alkali solution is consumed in the swelling treatment, and therefore this method is not desirable from an economical point of view either.

It has now been found that to improve the fiber properties without these disadvantages, it is extremely effective to use a process in which the threads, which are produced by extruding a viscose with a value of at least 50 in a formaldehyde-containing precipitation bath and by drawing of the filaments formed were obtained in a second bath, treated in an aqueous solution (third bath) containing an alkali, alkaline earth or ammonium salt of a mineral acid or mixtures of these salts , the third aqueous bath at a pH of 2.0 to 10.5 and at a temperature of 30 to 90 ⁰ C is kept . The third bath can contain a small amount of a zinc or admium salt of a mineral acid.

009831/1674

Are the fibers obtained by extruding a viscose with a high j / "value in a formaldehyde-containing precipitation bath and by drawing the filaments formed in a second bath in an aqueous solution of For example, sodium sulfate is introduced, so the swell The threads surprisingly open up a lot and sometimes even dissolve over time. This appearance is not just having Sodium sulfate, but also with other alkali, alkaline earth and ammonium salts of mineral acids are observed. This swelling effect is made strong by the pH value and the temperature the saline solution used. Therefore, the pH and the temperatures should be those used according to the invention Saline solutions are within the ranges given above. If the pH value is lower than 2.0, one occurs pronounced diffusion of hydrogen ions into the fiber, whereby the actual swelling of the fiber by the salt used is reduced. If, on the other hand, the pH value is .J higher than 10.5, the fiber swells very much and its toughness is considerably reduced. Even if in In this case, a zinc or cadmium salt of a mineral acid is added to the salt solution, the following can be used specified special effect cannot be achieved. Regarding the temperature, it can be said that the swelling effect the higher the temperature, the stronger the salt. However, if the temperature is excessively high, it progresses

009831/1674

the regeneration of the fiber continues, which makes the swelling of the fibers more difficult. The "preferred Beriandlungstemperatur is in the range 30-90 ⁰ C * It was also found that" when adding an aqueous solution of the salts indicated above, with swelling effect on the fiber small amounts, eg less than 0.5 g / Diter a Zitik - Or edmium salt of a mineral acid, the swelling of the fiber is well controlled and the fiber properties can be improved even more.

When performing the "method according to the invention in industrial scale is usually a third bath aqueous solution used containing "up to 50 g / diter of sodium sulfate and "contains up to 1 g / tdter sulfuric acid-, -Daa third However, bath is expedient with up to 0, Γ> g / diter sink sulfate offset,

Erfinäung3gemäß can aar fibers containing fsllungsbades using a Pcrinaläehyd have been generated, the invention Iiabici immei- be aehandelt with an aqueous salt solution, "Me drawn fibers according to still a high value Jf ~. From this one concludes that _f üis swelling or dissolution of these fibers uirfcer the action of said salts exerts on the Cellule- for £ fc "Hydroxymetbylj; back mT5kGgenat characteristic behavior ^ rtführeii is? the 9ΐκ. Äfjaktic ^ sp ^ Ou'ül-rt represents cellulose xanthate and formaldehyde.

In the accompanying drawings, Figure 1 is a graph showing the above relationship well expresses! Figure 2 shows the treatment according to fibers obtained according to the invention in cross section.

Figures 3 and 4 show the present fiber or a conventional fiber in side view.

Figures 5 and 6 show the defibered state (fibrillation state) of the present fibers or of conventional fibers.

In Figure 1, the sodium sulfate concentration in the third bath is plotted on the abscissa * while the dyestuff depletion, which is characteristic of the swelling effect, is plotted on the ordinate. The solid line shows the case in which a viscose containing 7 $ cellulose and 4 $ alkali with a j ^ value of. 80 and a viscosity of 260 poise was ^{extruded into a precipitation bath maintained at 25 °} C., which contained 26 g / liter sulfuric acid, 75 g / liter sodium sulfate, 0 ₅ 1 g / diter zinc sulfate and 7 _f 5 g / liter formaldehyde were contained in a stretched maintained at 80 ⁰ C to 38O $ second bath and then in a third, gshaltanen ^C to 70 C aqueous bath "the tiö eu 10 g / liter Na ■ fcriumsuifa-c and 0.1 g / liter Zinkaulfat , treated. The dashed line indicates the case where the treatments

BATH ORIGINAL

■ were carried out under otherwise the same conditions as above, but with the difference that no formaldehyde was contained in the plating bath and the stretching ratio in the second bath was 150 io . It is clear from this graph that there is no swelling effect at all if the precipitation bath contains no formaldehyde.

The conditions for determining the dye depletion are as follows χ

sample

Japanol Brillant Blue 6BEX sodium sulfate

Bath ratio

Tenoratura and Time

3 g

0.3% (based on fiber weight) 20 i * (based on fiber weight) 1: 100

45 ⁰ O χ 20 kin.

The specific absorption of the residual liquid is measured with the aid of a photoelectric colorimeter, whereupon the dye depletion is calculated.

In FIG. 2, the black parts show the surface-colored layer (skin-stained layer). For coloring the Surface were the following conditions applied?

Japanol Brillant Blue 6BKX (CI. Direct blue 1)

Sodium chloride

Temperature and time

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1% (based on fiber weight)

IO% (based on fiber weight) 100 ⁰ C χ 30 min.

In FIGS. 3 and 4, the black parts show the core-stained layer.

The following conditions were used for the coloring in the nucleus}

Solophenyl Fast Blue Green B.L. 1 $ (based on fiber weight) (CI. Direct green 27)

Sodium Sulphate $ 0.3 (based on fiber weight)

'' Temperature and time room temperature χ 5 hours

If the treatment method according to the invention is on threads applied, which were drawn in the second bath at a tension of less than 3 g / d, are the fibers formed better, without a noticeable decrease in tenacity, the lateral properties of the fiber, such as extensibility, Knot tenacity and abrasion resistance, as well as the dyeability and the degree of crimp occurs.

If the present treatment method continues to be applied to sutures that are in the second bath at tension have been drawn by more than 0.3 g / d, the fibers obtained have not only improved lateral properties, such as Extensibility, etc., and dyeability, but also one better resistance to shredding.

The invention is explained below on the basis of a case

009831/1874

ORIGINAL

which treats the fibers drawn at the lower tension in the second bath.

The '"value of the viscose used must be at least 50, preferably be at least 65 (corresponding to a salt point of at least 16). If the j "value is below this Value, the effect of the formaldehyde in the precipitation bath is insufficient and it cannot be satisfactory Develop ripple.

The formaldehyde concentration of the precipitation bath is preferably 5-15 g / liter. It is particularly desirable that the sulfuric acid concentration of the precipitation bath be within of the range defined by the equations below is «

Minimum concentration of sulfuric acid (g / liter) = 3A + 8 Maximum concentration of sulfuric acid (g / liter) = 8A + 16,

where A is the total alkali concentration in the viscose, which is preferably only 2-8 $> . The concentration of sodium sulphate is preferably 20-250 g / liter and that of any zinc sulphate added is expediently up to 0.3 g / liter.

The threads pulled out of the precipitation bath are then

009831/1874 ^{m / m}

stretched in the second bath. In this case, the bath temperature and the tension applied to the fibers during drawing are the most important factors. The temperature of the second bath is preferably in the range of 45 -75 ⁰ C. If the bath temperature is outside this range, then no excellent crimp may develop. The tension applied to the fibers during drawing should be less than 0.3 g / d. If the tension is higher than 0.3 g / d, highly curled fibers cannot be obtained. The second bath preferably contains a small amount of sulfuric acid in view of the subsequent treatment. The bath can also contain small amounts of salts and formaldehyde.

The fibers stretched in the manner indicated above are then either still as threads or after being cut into staple fibers, relaxed in a third bath, which is an aqueous salt solution in which the fibers swell and at the same time develop pronounced, fine crimps. In this case, the temperature of the third bath advantageously 30 - 70 ⁰ G. If the temperature below 30 ⁰ C, the swelling effect is small, while no more excellent crimps are developed at temperatures of more than 70 ⁰ C. The curled fibers are then placed in a high temperature acidic bath to complete the regeneration.

009831/1874 /.

The fibers obtained by this process have the properties given below.

The cross-section and the side view of the fibers have the particular shape shown in FIGS. 2 and 3, respectively In the fibers, the core-stainable layer is arranged at an angle. So the fibers have one heterogeneous structure as if they were composite fibers. the The crimp of the fibers is helical, but different from the usual crimped staple fibers, as shown in 4, the layer which can be dyed in the core is always on the inside or inside track of the crimping sheet. In water, the crimp therefore stretches somewhat as a result of the greater swellability of those that can be dyed in the core Layer} however, it returns to its old form when it dries. This means that the fibers according to the invention Representing composite fibers with so-called water-reversible crimps «This contrasts with the usual composite fibers (conjugate fibe'rs) or the so-called "broken skin" crimped staple fibers made of viscose, the surface-dyeable layer is always on the inner lane of the curling sheet. Furthermore, in the case of the usual crimped viscose staple fibers, the thicker side is the one that can be dyed on the surface Layer on the inside trace of the curling sheet. These fibers behave differently to water than the fibers according to the invention. It is believed that the excellent

009831/1674 ^{# /} '

Crimping properties of the fibers according to the invention are due to the specified particular structure, which differs fundamentally from that of the usual crimped viscose staple fibers.

The filaments according to the invention have not only excellent curling properties but also excellent mechanical properties. The tenacity and the wet modulus of the fibers are much higher than those of the usual crimped viscose staple fibers. In particular, the wet modulus of 5 $ elongation for the present fibers is generally 0.5-1.8 g / d or higher. Therefore, the fibers have excellent dimensional stability and can withstand repeated washing. They also have high knot tenacity and excellent abrasion resistance. The water retention capacity of the fibers is equal to or slightly higher than that of newer polynose fibers, while the water resistance and the dimensional stability are sufficiently high. Another good property of the fibers is their excellent dyeability. "Expressed in numbers, the fibers show a dye depletion of more than 4-0 #, usually in the range of 45-85 #, a wet tenacity of 1.8-4 g / d, a wet modulus at 5 ° elongation of 0.5 to 1.8 g / d and more than 10 crimps to 25 mm.

009831/1674

Because of this excellent frizz and mechanical Properties can be used for a large number of fabrics with or without synthetic or cotton fibers will. Fabrics made from these fibers have a pleasant feel, high slip resistance and high dimensional stability and excellent mechanical properties.

The invention is further explained on a case "at which was subjected to the salt treatment in the second bath at a tension of more than 0.3 g / d will.

The J ₁ ^ value of the viscose used should be at least 50 % . If it is lower, the fibers in the second bath cannot be drawn strongly enough, with the result that not only cannot fibers with high tenacity be obtained, but also that the effects of the salt treatments cannot be exhibited sufficiently.

A bath containing sulfuric acid, sodium sulfate, zinc sulfate and formaldehyde is used as the precipitation bath. In some cases, however, zinc sulfate need not be included in the bath . The formaldehyde concentration in the bath is 1-15 g / liter, preferably 3-10 g / liter. The threads pulled out of the precipitation bath are immediately strongly stretched in the second bath. In this case, the tension applied to the threads should be

009831/1674

be at least 0.3 g / d. If the tension is less than O> 3 g / d, the drawing becomes insufficient, so that it is no longer possible to obtain fibers with high tenacity. Because of the subsequent salt treatment, the second bath is preferably a bath with a low sulfuric acid concentration. Furthermore, the temperature of the second bath should be at least 60 ⁰ ". If the temperature is lower, the fibers cannot be stretched sufficiently. The threads stretched in the second bath are then treated in the relaxed state with an aqueous solution of the aforementioned salt . were strongly stretched, the fibers, as to the treatment temperature in the range of 40 -. be kept 90 the temperature is below 40 ⁰ C, so only a small swelling effect can be achieved, while at temperatures of more than 90 ⁰ C, the regeneration of the fiber progresses so far that only a small swelling effect is also achieved.

The salt-treated fibers are then placed in a high temperature acid bath for regeneration to complete.

Will be proportionate in the salt treatment given above When strong swelling conditions are applied, the cross-section of the fibers can and it can be varied under certain circumstances even hollow fibers can be obtained.

009831/1874 /

The following examples illustrate the invention.

example 1

A 6.5 $ cellulose and 4.5 ^ Total alkali-containing viscose with a viscosity of 170 poise, a salt point of 21 and a κ "value of 82 is extruded into a precipitation bath maintained at 25 ⁰ C containing 35 g / liter of sulfuric acid , 75 g / liter of sodium sulphate and 7 g / liter of formaldehyde. The threads pulled out of the precipitation ^{bath are placed at a tension of 0.05 g / d in a second bath maintained at 60 0} G, which contains 2 g / liter of sulfuric acid, Immediately stretched to $ 300 of their original length. The fibers are then placed in a third ^{bath, kept at 50 °} C. and at a pH of 6.8, which contains 5 g / liter of sodium sulfate and 0.1 g / diter of zinc sulfate, relaxed to form crimps. The: "values of the fibers just before entering the second and third baths were 65 and 57, respectively.

The regeneration of the fibers is then completed in an ^{aqueous bath maintained at 85 °} C. and containing 5 g / Li ^ er sulfuric acid, whereupon the fibers are subjected to a degreasing treatment in a manner known per se. The fiber properties of the fibers thus obtained are shown in Table 1- (A)? Figure 2 shows the cross sections of the fibers after dyeing.

009831/1674 ./.

For Vsrglsioh the fibers (B) in the same manner as C were shown JBN ^1, with the exception that the third bath L: -3in§ containing sulfates and was maintained at 50 ⁰ C. The properties of these fibers are shown in Table 1- (B).

009831/1674

Table 1

Titer toughness, Naßaä ~ elongation, wet knot- B "aß ~ number of Krausol ~ i'ai'bs' (denier? Conditio- ness condition- elongation toughness modul Ivräuse- gray erased ) ned (g / d) ned (%) conditional with 5% lungs Xfo) ( ^c / o) (g / d) (96) nates elongation to 25 mm

3.7

12th

1.9

1.1

23

³ S ³ '°

3.9

10

1.4

20th

; 669501

- Example 2

Eins 7 io Öallulosa and 4,5 # .Alkeli &: _ ■■:>? .. lts: i :: β viscose with a viscosity τοπ 320 Poise, ^ .Ir ^ z, Bal2: pv..nkv " ^r on 22 and a y "~ value of 64, It ... " N avif 2? ⁰ g of a full precipitation bath was extruded which contained 37 g / liter sulfuric acid, 10 g / liter sodium sulfate and 8 g / liter "i orüialashyd" .iten 2.:;i, UEAs 1 g / contained and Diter sulfuric -ν · :: iO ⁰ O ^ ^ s ^ l s v \ nirdej immediately aiii '290 fo of its original length stretched. spell were the threads in a ⁼ third bath maintained at 5- " ^: " ^, which contained 0.2 g / liter of sulfuric acid, 10 -r / tiiter of sodium sulphate and 0.1 g / liter of zinc sulphate, ": · 5ΐ ~" 0 ⁰ C and at a pH -Value of 3.4 relaxed to form crimps. Then the regeneration of the fibers was completed in an aqueous ^{bath maintained at 85 0} G and containing 5 g / liter sulfuric acid. The L- " values of the fibers immediately before the entry into the second and third Sad were 66 and 59, respectively.

The fiber properties of the fibers thus obtained are shown in Table 2- (A). For comparison, the fibers (B) were produced in the same way as above, with the difference that the third bath contained only 10 g / liter of sulfuric acid and had a pH of 1 _? A was held. The fiber properties of this fiber are shown in Table 2- '^; *: * & ■ £ g'ibi? ■. *

009831/1674

BATH ORIGINAL

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009831/1 67

Example 3

A viscose containing 7 1 ° cellulose and 4 % alkali with a viscosity of 340 poise and a _ | "Value of 83 was ^{extruded into a precipitation bath maintained at 25 0} G, which contained 16 g / liter of sulfuric acid, 80 g / liter of sodium sulfate, 0.2 g / liter of zinc sulfate and 7 g / liter of formaldehyde precipitation was extracted filaments were d maintained at a voltage of 1.2 g / in a second bath containing 1.2 g / liter of sulfuric acid and ⁰ to 80 C, "immediately stretched to 45O io their original length. After cutting into staple fibers, the fibers were treated for one minute in a third bath which contained 0.1 g / liter sulfuric acid, 10 g / liter sodium sulfate and 0.1 g / liter zinc sulfate and which "at a pH of 3» 5 and "was kept at a temperature of 65 ^° C. The '> value of the fibers immediately before entering the third bath was 32. The regeneration of the fibers was then completed in an ^{aqueous bath maintained at 75 °} C. and containing 5 g / liter sulfuric acid. The fiber properties of the fibers thus obtained are shown in Table 3- (A). For comparison, fibers were produced in the same manner as above, except that the drawn fibers were cut into staple fibers and then immediately subjected to regeneration without treatment in the third bath. The fiber properties are shown in Table 3- (B).

009831/1674

Table 3

Titer Naßzä- barrel-r knot- dye- defiber- (the! Ability elongation tough- creation state d) (i / d) (<f °) speed (#)

■ Conditioned (g / d)

A 1.3 5.3 H 7.5 '84 see Pig. 3 B 1.2 5.8 9 1.9 27 see Fig. 4

Figures 5 and 6 are photographs showing the state of disintegration of the fibers after the fibers have been cut to a length of 5 mm for 10 minutes with 10,000 times the amount of water at 20 ^° G using a 320 watt household mixer with 3000U / kin. turned, were stirred.

009831/1674 /

Example 4

The same viscose as in Example 3 was ^{extruded into a precipitation bath maintained at 25 °} C. and containing 15 g / liter sulfuric acid, 75 g / liter sodium sulfate, 0.2 g / liter zinc sulfate and 8 g / liter formaldehyde. The threads pulled out of the precipitation bath were immediately opened at a tension of 1.1 g / d in a second bath which contained 1 g / liter sulfuric acid and was kept at 75.degree

410 i * stretched to its original length. After cutting into staple fibers, the fibers were 2 1.II nut s in a maintained at 70 ⁰ O third bath containing 5 g / liter of sodium sulfate and 0.1 g / liter containing zinc sulfate, at a pH value of 7.0 . The Rf value of the fiber immediately before entering in the third bath was 39 · Then, the regeneration of the fibers in a maintained at 80 ⁰ G bath containing 5 g / Eiiter sulfuric completed. The fiber properties of the fibers thus obtained are shown in Table 4- (A): About 10 μs of the fibers obtained were hollow.

For comparison, fibers were produced in the same way as above, with the difference that the third bath did not contain sulfates and was kept at 70 ^° C. The fiber properties of these fibers are shown in Table 4- (B).

009831/1674

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- patent claims -

009831 / 167A

Claims (10)

Patent to claims ι 1. Process for the production of improved polynose fibers, characterized in that one is a viscose with a '"Value of at least 50 is extruded into a formaldehyde-containing precipitation bath, the threads formed are drawn in a second bath, the drawn threads are treated in a third aqueous Sad which contains an alkali, alkaline earth or ammonium salt of a mineral acid or mixtures of these salts , the third aqueous bath being kept at a pH of 2.0-10.5 and at a temperature of 30-90 ⁰ O and subjecting the fibers to a regeneration treatment. 2. The method according to claim 1, characterized in that a bath is used as the third bath, which additionally up to 0.5 g / liter of a zinc and / or cadmium salt contains a mineral acid. 3. The method according to claim 1 and 2, characterized in that that a third bath is used which additionally contains up to 1 g / liter of sulfuric acid. 4. The method according to claim 1 to 3> characterized in that a third aqueous bath is used, which is up to Contains 50 g / liter sodium sulfate and up to 0.5 g / liter zinc sulfate. 009831/1674 5. The method according to claim 1 "to 3> characterized in that the threads formed in the precipitation ^{bath in the second bath held at 45-75 0} C" stretched at a tension of "up to 0.3 g / d and then in one at 30-70 ⁰ C held third bath "treated. 6. The method according to claim 5, characterized in that a viscose with a total alkali content of 2-8 $> and a salt point of at least 16 is extruded into a precipitation bath containing 4-15 g / liter of formaldehyde, 20-250 g / liter of sodium sulfate and contains sulfuric acid in a concentration determined by the following equations "* Minimum concentration of sulfuric acid (g / liter) = 3A + maximum concentration of sulfuric acid (g / liter) = 8A + 16, where A is the percentage alkali concentration in the viscose means. 7. The method according to claim 6, characterized in that a precipitation bath is used, which in addition up to 0.3 g / diter of zinc sulphate. 8. The method according to claim 1 to 3 »characterized in that the threads formed in the precipitation bath in the second, held at more than 60 ⁰ C bath at a tension of at least 0.3 g / d and then stretched in the third .40-90 ⁰ C held bath treated. 009831/1674 - do - 9. Heavily crimped polynosis fiber with a heterogeneous structure that is asymmetrical in the cross-sectional direction of the fiber, in which a layer that can be dyed in the core is always on the inner track of the curling sheet and in which the dye creation is at least $ 40 « 10. Paser according to claim 9, characterized in that it has a wet toughness (wet tenacity) of 1.8-4 g / d, a wet modulus at 5 $> elongation of 0.5 to 1.8 g / d and more than 10 crimps to 25 mm. 009831/167 if. Blank page