DE956399C - Process for the production of artificial fibers, foils and the like interspersed with cavities. Like. Shapes - Google Patents

Description

The invention relates to conversion such well-known finished structures made of regenerated cellulose, cellulose esters, proteins, alginates, which are swellable in water, in the form of fibers, films, tapes, etc., in the following Description Called a "structure", in an inflated, porous, spongy form. These wise Compared to the original structures, the following "advantages: better thermal insulation, increased volume, softer and fuller handle, wavy or curly and grained surface, reduced gloss and better penetration for dyes and post-treatment solutions. This transformation does not noticeably weaken the structure ·.

Various methods are known to convert into synthetic fibers, such as. B. viscose fibers, cavities to form, among them, the vegetable or animal fibers which naturally form such cavities included to make it more similar. All of these processes are based on a modified spinning solution, z. B. viscose, from. This can contain finely divided gas bubbles in suspension, or it can be dissolved in it substances that develop gas during the spinning process, such. B. Sodium Bicarbonate. The spinning liquid can also be solid,

contain suspended powdery substances which are subsequently released from the threads and leave voids behind. These procedures are cumbersome and increase the difficulty in doing so Spinning process. The fibers thus obtained are unsatisfactory in various respects. Either If the spaces are too large, the threads are tubular and easily compressible (Cell floss), or they are too small and ineffective. The strength of such fibers is considerable degraded.

According to the present invention, the cavities are in contrast to the known methods produced in finished structures. It is not necessary to have a specially prepared spinning solution to use, still to change something in the spinning process. The ones to be treated. Structure can be used as single threads in the continuous process, in strand, woven fabric, knitted fabric or finished articles subsequently be treated by the dyer or finisher. The manufactured according to known processes, structures interspersed with bubbles are often such that the surface is exposed to the escaping gas was torn, while the structure produced by the process according to the invention was a grained one and have a corrugated, but intact, closed surface. Microscopic observation shows that the microfibrils of the structures partially separate from one another due to the evolution of gas have been separated without tearing. The strength of the structure is therefore only insignificant degraded.

The inventive method consists in to treat the structures with swelling aqueous solutions, one of which is one of them Contains substance which evolves a gas through catalytic decomposition. It is here not a double reaction, as in the case of sodium bicarbonate with acid, where gas is generated comes to a standstill after the equivalent amounts of reagents have been used up. By being there of a catalyst inside the structure, gas is evolved as long as a substance which emits gas when it decomposes, is added to the catalyst. The catalyst will introduced into the structures with the aid of an aqueous solution containing catalyst substance. the Formations can first with this solution and then with the gas evolving liquid or vice versa Order to be treated.

It has been found that hydrogen peroxide develops extraordinarily as a gas-evolving substance well suited. The following description relates to its use. It can go through Metal compounds that have different levels of oxidation, such as manganese or lead compounds, e.g. mangano-manganite compound, pemianganate, sodium plumbate, catalytically under Development of gaseous oxygen can be decomposed. The catalyst can also only be inside the structure to be treated are generated by a non-catalytically active substance such as z. B. Manganosulfat, Manganochlörür, Manganonitrat etc., brought into the interior of the structure in aqueous solution, then with after-treatment an alkali hydroxide solution and oxidizing agents is converted into a catalyte.

Another method to following this procedure To create voids and bubbles in the structures is as follows:

The structures to be treated are saturated with concentrated neutral or acidic hydrogen peroxide, which contains a non-catalytically active, water-soluble manganese salt. Subsequent treatment of the structure in an alkali hydroxide bath converts the manganese compound into a catalyte, which causes the strong evolution of gas. The shape, size and distribution of the gas bubbles generated are determined by the type and physical condition of the tissue as well as by the intensity and duration of the gas evolution. This can be influenced as desired in a precise, reproducible manner by regulating the concentration of the solutions, the temperature and, in particular, through. Addition of salts in various concentrations, which in themselves do not catalyze the decomposition of the peroxide. Thus, alkaline substances increase the swelling of the structures, while z. B. sodium sulfate and sodium chloride reduce this. In general, the process runs at room Tempe ¹ -ratur in a satisfactory manner, but one can; If necessary, accelerate it by heating or delay it by cooling. If a single treatment does not produce the desired effect, the procedure can be repeated. In this way powerful effects can be achieved under very mild conditions.

Tissues or foils can also only be treated topically be done by z. B. the catalyst or the gas-generating substance in the form of a Pattern imprinted or stenciled. Similarly, one can use the fabric or the film by impregnation with a water-repellent substance partially against the effect of the treatment agent Reservations. In this way, one can use itm to take advantage of the diversity Gloss and 'the coloring ability achieve different effects.

The structures treated according to the method have a volume that has been increased several times, they have an increased volume Opacity and therefore give thicker and softer fabrics with the same weight. That Thermal insulation capacity is improved by the enclosed bubbles and the larger volume. Due to the cavities present in the structure, there is an additional matting through production a deposit inside the same possible, so that a matting is achievable, the is particularly effective because the embedded solid matting agent on the walls of the Cavities cause particularly strong light refraction effects compared to a gas. The in. The Matting agent embedded in voids is also less easily washed out than it is e.g. B. at matting agent applied to the surface

medium is the case. This new matting process also gives the viscose structures more weight.

Treated by the method according to the invention te structures are penetrated better by the dyebaths, and therefore more easily stained, and the colors have a pastel-like character. Differences in color absorption will be especially with woven and knitted fabrics, ίο that tend to be unevenly stained, largely equalized.

In the aftertreatment of foils and tapes, the resulting bubbles and changes are the surface immediately apparent. To the structure and surface changes of To illustrate structures that have been treated according to the invention are the special structural elements Changes for fibers shown in the eleven drawings.

Figures 1 to 5 show photomicrographs of treated Viscose fibers, Figures 9 to 11 titre curves. Fig. Ι shows ordinary rayon fibers in Cross-section,

Fig. 4 is a longitudinal view;

Figure 4a is a single fiber, enlarged;

Fig. 2 shows the cross section of the same fiber after treatment,

FIG. 5 shows a longitudinal view and FIG. 5 a shows a single fiber;

3, 6 and 6 a show, in an analogous manner, more heavily treated fibers with simultaneous storage of barium sulfate.

5 a and 6 a show very clearly how the micron glasses are pushed apart, and the undulation of the surface. It can be seen that even the fibrils on the surface did not boil, although the stress was greatest there. The Viviani apparatus, which is generally used to determine the regularity of the thread cross-section, gave the curves in FIGS. 9, 10 and 11 for a strand of viscose artificial silk of which only about two-thirds of its circumference was treated according to induction (FIG. 9 a). In the curves, the points A denote. the treated part and the points B the treated part of such a strand. There are three treatments of different strengths listed. In Fig. 9 the volume increase is 30 to 40 ⁰ Zo, in: Fig. 10 50 to 70% and in Fig. 11 to 160%. The curves show that the increase in volume is very uniform. To the same extent as the volume, the absorbency is increased by the aftertreatment after this process, and the thermal insulation is also increased proportionally to the increase in volume.

Fig. 7 shows an enlarged view of a Vis skosegewebes,

Figure 8 shows the same tissue after treatment. The increased density of the tissue is very evident.

The following examples show different ways of carrying out the process according to the invention Procedure, but without wishing to restrict the same to it.

example 1

Viscose rayon in strand or fabric form is immersed in a solution containing 2 g of potassium permeationate and 150 g of sodium chloride per liter. After removing the excess solution, the fibers or fabrics are thawed in a solution of 300 g of sodium sulphate and 300 g of magnesium sulphate in 1000 ecm of 30% hydrogen peroxide. After a contact time of at most 2 minutes of Zersetzunigsprozeß inside the Viskosegöbilde is interrupted by entering into an i ^fl / oiges acetic acid bath. Then it is washed thoroughly and dried. The ratio of the to be treated. Viscose structures for the treatment baths should be ι: 20.

Example 2

Viscose ribbons in strand form are pretreated for 5 minutes in an aqueous solution of 1% manganese sulfate. After dripping off or spinning off, the tapes are treated with a 2% sodium hydroxide solution for 2 minutes and rinsed well with water. The viscose tapes pretreated in this way are then exposed to a 20% hydrogen peroxide solution in a third treatment bath. The action of hydrogen peroxide sold after 2 minutes to be interrupted by switching g ^ immerse the inflated Viskosegebilde in a i- to 2% acetic acid bath. The aftertreated viscose ribbons; are washed and dried. The ratio of the \ ⁷ to be treated 'iskosegebilde to the treatment baths to 1: 20 in.

Example 3

Viscose films in sheets or cut into ribbons are placed in an aqueous solution of 1% Manganese sulfate and 40 ^ / 0 hydrogen peroxide swollen. After draining, the films are immersed in a 10% sodium hydroxide solution aftertreated, washed in an acetic acid bath of 1 g per liter and dried. The ratio 110 of the foils to be treated for the treatment baths should be about 1:20.

Example 4

A viscose rayon fabric is dipped into a saturated Bariome-Moirid solution, which per Liter contains 2 g Kaliuimpermanganat, and then centrifuged. Then you pull the fabric through a solution of 150 g of magnesium sulfate, 150 g of sodium sulfate and 500 ecm hydrogen peroxide (40%) in 500 ecm water. The weight ratio of the viscose fabric to be treated to the treatment baths should be ι: 20. After this Washing and drying increased the titer of the threads in denier from 100 to 125, i.e. h., it

25 g of barium sulfate per 100 g of threads were incorporated. The increase in volume is such that the thread, which was originally 100 denier, has the volume of a thread of 250 denier, and the absorbency increases in the same degree by at least 100 ^fl / o. All other viscose structures (rayon, foils, ribbons, etc.) can be treated in the same way.

Example

Copper oxide ammonia artificial silk (e.g. 120/90) in strand or fabric form is immersed in a solution for 5 minutes,

ig the per liter 2 g of potassium permanganate and 10 g Contains crystallized sodium sulfate. After removing the excess solution, the Fibers or the fabric in 40% hydrogen peroxide. After an exposure time of at most ι minute the decomposition process inside the fibers is interrupted by typing in an acetic acid bath; this is followed by thorough washing, finishing and drying. The ratio of the fiber material to be treated to the treatment baths should be 1:20. Through this After treatment, the volume of the copper oxide ammonia silk is significantly increased.

Example 6

Nitro silk in strand form is dissolved in a solution of 0.2% potassium permanganate and 2% sodium sulfate (crystallized) immersed at room temperature for 3 minutes and after centrifuging or draining Post-treated for a maximum of 2 minutes in a 20% hydrogen peroxide solution. To Thorough washing, the nitro hollow silk is finished and dried.

Example 7

Acetate rayon in Strangfocm is / dipped 5 minutes in i ° cent, potassium permanganate of 8o °, briefly rinsed with water, post-treated with 30 ⁰ / pc alcohol hydrogen peroxide at most 2 minutes, thoroughly washed, brightened and dried.

Example 8

Casein silk (protein fiber) is immersed in a solution of 0.05% potassium permanganate and 1% sodium sulfate (crystallized) for 2 minutes, after draining or spinning for a maximum of 2 minutes in a ^{2o containing i fl} / o (crystallized) sodium sulfate % Hydrogen peroxide solution and dried after thorough washing.

Example 9

Alginate silk. 40 ecm of a 20% lead acetate solution 20% sodium hydroxide solution is added until the lead hydroxide is dissolved (about 160 ecm) and diluted with water to 1000 ecm. The alginate silk is immersed in this alkaline sodium plumbite solution for 1 minute and then afterwards after the dripping in a weakly acetic acid io% hydrogen peroxide solution, thoroughly washed, finished and dried.

Claims (9)

PaTENTA NS P R 0 C H E: 1. Process for the production of artificial fibers, foils, interspersed with cavities and the like. Shapes using gases-evolving substances, characterized in that, that in any way produced, water-swellable fibers or moldings on the one hand with aqueous solutions of substances, preferably manganese compounds, which are either already catalytic act or through the addition of reagents such as alkali hydroxide and similar bases, as well as Oxidizing agents form a catalyst and use hydrogen peroxide as a gas-evolving agent Substance. 2. The method according to claim 1, characterized in that that the treatment with the catalyst solution and a solution of the gas ^ developing substance takes place separately, in any order. 3. The method according to claim 2, characterized by the use of an aqueous one Solution of 0.5 to 20 g of alkali permanganate per liter and a 30 to 40 volume aqueous Hydrogen peroxide solution, the latter acting on the material for a maximum of about 2 minutes leaves. 4. The method according to claim 2, characterized in that the fibers or shaped structures may be treated sequentially with a 0.1 to io ^fl / o aqueous solution (eg. As manganous sulphate, Manganochlorür, Manganonitrat) of a Manganosalzes, then with a 0 1 to 10% aqueous alkali metal hydroxide solution and finally a maximum of about 2 minutes with a 10 to 40% strength. Hydrogen peroxide solution. 5. The method according to claim 1, characterized in that the fibers or shapes with a 20 to 40 ⁰ / oigen hydrogen peroxide solution, the 1 to io ^fl / o of a non-catalytically acting Manganas al zes (z. B. Manganosulfat, Manganochlorür, Manganese nitrate) is treated, then with a 1 to 10% aqueous alkali metal hydroxide solution. 6. The method according to claim 1 to S, characterized in that the manganese compounds or a solution containing corresponding substances which reduces the swelling of the substance attached, such as sodium chloride, sodium sulfate, magnesium sulfate. 7. The method according to claim 1 to 6, characterized in that at the same time with the inflation the structures inside the cavities chemically produce a precipitate which weighs down the structures and acts as a matting. 8. The method according to claim ι to 7, characterized marked that the hydrogen peroxide solution contains a stabilizer. 9. The method according to claim 7, characterized in that that barium sulfate is stored in the cavities by adding a catalyst solution with sodium or magnesium sulfate addition and a hydrogen peroxide solution used with the addition of barium chloride or vice versa. Considered publications:
German patent specifications No. 274044, 521055. 1 sheet of drawings 609 755 1.