DE594859C - Process for the production of rayon with elementary threads from 6 to less than 1 denier by spinning viscose solutions - Google Patents

Description

GERMAN EMPIRE

ISSUED ON MARCH 22, 1934

REICH PATENT OFFICE

PATENT LETTERING

JVe 594859 CLASS 29b GROUP 3 ^.

by spinning viscose solutions

Patented in the German Empire on July 11, 1931

The invention relates to a process for spinning rayon with filaments of 6 to less than 1 denier, which consists in that viscose with a low cellulose content, to which an excess of carbon disulfide is added or which has been produced with the addition of an excess of carbon disulfide, in the normal way is spun in acidic salt baths. As a

to normal CS ₂ content an amount of about 45% C ^ 2 ^'o f the presence of α-cellulose calculated considered.

Such spinning solutions result in a rayon with a particularly good grip that is uniform stains and also has great extensibility while also being able to do so Silk with fine filaments up to less than ι denier, which is very strong when wet, to spin.

The addition of an excess of carbon disulfide to normal viscose is known per se. The purpose of this well-known addition is to influence the ripeness or shine of the thread. However, the effect that is achieved in the present method does not occur a.

It has also already been suggested that the viscose should be made of low thread count for the purpose of spinning to dilute. One has z. B. instead of viscose with 7 to 8% cellulose a viscose with 5% cellulose applied. You can use it to produce a thread with considerably finer threads Capillary threads spin than is possible with undiluted viscose, but when the capillary denier comes close to 2 or below, the capillaries have a tendency to stick together. Because the individual threads are no longer loose, the silk has the appearance of a glued thread.

The method according to the invention enables, even with very low thread thicknesses of yarns, the capillary threads of which are completely loose, the thread having a very good strength having.

It has also been proposed (see French patent 667 542), similar ones Element threads made from completely unripened viscose solutions and completely unripened sodium cellulose to be spun in very special, very long baths at low temperatures. According to the invention is z. B. for 1 to 2 days matured alkali cellulose sulfided in the normal way, the As is customary in the rayon industry, the sulphidation boiler is blown off and the xanthate brought into the dissolving tank for the production of the viscose.

*) The patent seeker stated as the inventor:

Dr. Lambertus Alexander van Bergen in Breda, Holland,

When dissolving, a certain amount of carbon disulfide is added immediately, e.g. B. 20 to 40 ⁰ I ₀ the usual amount for sulfiding. It is also possible to add about 10 to 11 parts of carbon disulfide to 100 parts of α-cellulose in addition to the amount of about 45 parts already used.

The added carbon disulfide is absorbed by the viscose within a very short time, so that no harmful or dangerous consequences are to be feared when carrying out this procedure.

The viscose with z. B. a cellulose content of about 5 to 6 ⁰ J ₀ is then filtered in the normal way, further treated and spun in the usual way in normal spinning baths.

Example 1 20

A highly viscous viscose of the usual composition with 8% cellulose and 7% NaOH content is converted into a dilute viscose containing 5.7% cellulose and 5% NaOH. _{7 parts of CS 2 are} added to 1000 parts of this viscose and mixed. After normal ripening, the viscose is processed in conventional spinning baths under normal conditions on threads of 105 denier with 75 capillaries.

Example 2

A viscose of the usual composition with 8% cellulose and 7 ° / _? NaOH content _J however

very high viscosity, is diluted to a viscose containing 4.1% cellulose and 5.5 ⁰ Z ₀ NaOH. 17 parts of CS _{2 are then} added and, after mixing and ripening, the solution is spun in the customary manner on threads of 105 denier with 75 capillaries.

Example 3

Alkali cellulose with 25% cellulose content is sulfided after 2 days of maturation with 11 ¹ J ₁ parts CS ₃ per 100 parts alkali cellulose. It is a viscose obtained with 5.2 ° / ₀ cellulose and 5.2% NaOH content.

A thread with 75 capillaries of 105 denier is made from this viscose in the usual way.

Result of the thread test:

In addition to the rayon according to Examples 1 to 3, produced with an excess of CS ₂ , comparative samples were also produced in the same way, but without the addition of C Sa. The determination of the tensile strength and elongation, converted to 100 denier, gave the following figures:

According to example 1

with CS ₂ ....

without CS ₂ ...

According to example 2

with CS ₂

without CS ₂ ...

According to example 3
with CS ₂ ....
without CS ₂ ...

Dry

Tear-resistant
speed

strain

137 ί 21.2

95.5- 9-4

135
80

18.6
■ 14.2

132! ig, o
85.2! 12.5

Wet

Tear:

consolidate

speed

^Deh "

; ^6s

54.3 ¹ 28.3

26.3 '14.3

53 j 26.5

19 I 22.6

63.5! 25.2

22 j 17.2

Incidentally, the method can also be carried out in various ways. One can z. B. add the excess of carbon disulfide during sulfiding or from one Viscose normal composition run out, this later the excess carbon disulfide add and then dilute the viscose to the desired cellulose content.

However, it is necessary to adapt the excess of carbon disulfide to the degree of dilution; the lower the cellulose content, the more carbon disulfide must be added to achieve the same effect.

In the above embodiment, the speech of a cellulose content by 5 to 6 ° was / _0; however, this percentage can also be taken lower or higher.

The caustic alkali content of the diluted viscose must be adapted to the circumstances and can switch between 4 and 8%. Also the age of the alkali cellulose can be different to z. B. to bring the viscosity of the finally obtained viscose to the desired value.

Claims (2)

Patent claims: 1. Process for the manufacture of rayon with filaments from 6 to less than ι denier by spinning viscose solutions, characterized in that viscose with a low cellulose content of at most 6% »either after its preparation Carbon disulfide has been added or the addition of an excess on carbon disulfide, spun in the usual way in acidic salt baths will. 2. The method according to claim 1, characterized characterized in that the required "5 amount of carbon disulfide is all the higher, the lower the cellulose content of the viscose.