DE1250963B - Wet spinning process for the production of fibers and filaments from cellulose triacetate - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. CL:

DOIf

German class: 29 b -3/30 OIL-

Number:
File number:
Registration date:
Display day:

W21920IVc / 29b
September 21, 1957
September 28, 1967

3) ολ F -

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The relatively low strength of cellulose triacetate fibers can be improved, as is known, that the threads during or after spinning, expediently in a plastic state. In this way, although the tear strength are increased, but the transverse elastic properties are worsened. Above all the elongation becomes lower and the loop strength is decreased.

In the wet spinning process for cellulose acetate threads, it is necessary to use a liquid for the coagulation bath to use, in which the cellulose acetate is insoluble, but with which the solvent of the Mix liquids containing cellulose acetate. This is intended to remove the solvent be facilitated from the precipitated thread by diffusion into the spinning bath. So are for example Coagulation baths made from organic liquids such as ether or aromatic hydrocarbons in Combination with a cellulose acetate solution in a mixture of methylene chloride and a little alcohol known. In conjunction with similar cellulose acetate solutions, water can also be used as a spinning bath will. The spinning solutions can contain a significantly higher proportion of methyl or ethyl alcohol contain. For example, it is known to add additives to the cellulose acetate solution which are used in are insoluble in the spinning bath and therefore remain in the thread and give it a shimmering appearance impart heating, such as adding diethylene glycol to a solution of cellulose acetate in Acetone and the spinning of this solution in a spinning bath based on kerosene, with which the diethylene glycol does not mix.

Spinning baths have also been proposed which have a strong swelling capacity on the Ccllulose threads have, whereby a spinning bath is very effective, which a high proportion of the used in the context of the spinning solution Contains solvent. Spinning solutions and spinning baths containing methylene chloride are included Advantage to use for cellulose triacetate. The invention relates to this class of wet spinning processes.

With the method according to the invention it is now possible to produce threads or fibers from cellulose triacetate, which are characterized by improved technological properties. In particular, they are the disadvantages described initially avoided, which have hitherto been improved in the manufacture of threads with Strength have occurred.

The invention accordingly relates to a wet spinning process for producing threads or a wet spinning process for producing fibers
and filaments made from cellulose triacetate

Applicant:

Celanese Corporation of America,

New York, N.Y. (V. St. A.)

Representative:

Dr.-Ing. A. v. Kreisler, Dr.-Ing. K. Schönwald,
Dr.-Ing. Th. Meyer and Dr. JF Fues,
Patent attorneys, Cologne, Deichmannhaus

Named as inventor:

Dr. Paul Ernst,

Dr. Walter Fischer, Burghausen (Obb.)

Cellulose triacetate fibers, characterized in that a homogeneous solution of Cellulose triacetate in a mixture of at least

* 5 90 ° / ₀ methylene chloride and monohydric alcohols with 1 to 4 carbon atoms and / or water-soluble glycols with 3 to 6 carbon atoms or the monoethers or polymers of these glycols spun into a precipitation bath, which consists of a mixture of water, 10 to 15 ° / ₀ methylene chloride and not more than 70 ° / ₀ water-soluble glycols with 3 to 6 carbon atoms or their monoethers or polymers.

The products obtained thereafter have an unusually high tear strength, at the same time high elongation, excellent transverse elasticity and loop strength. This not only results in significant advantages in terms of use, but also in terms of processing.
It is advisable that the viscosity of the precipitation bath is not more than 10 cP and that it has a temperature of 20 to 40.degree. The water content of the same may, however, only be so high that the methylene chloride is still clearly soluble. Any desired denier strengths, for example from 1 to 50 denier, can be spun in this way.

The filaments or fibers of cellulose triacetate obtained according to the invention correspond to one Tear strength up to 2.5 g / all textile requirements with regard to high elongation, transverse elasticity, Abrasion resistance, loop resistance, etc. Another advantage is that the can be easily regenerated Precipitation bath that needs to be heated up to the boiling point of the water in order to remove the methylene

709 649/408

Claims (1)

to recover chloride. The precipitation bath adhering to the fiber is without washing with water Difficulties remove and can be recovered practically quantitatively. example 1 A homogeneous solution of 19 weight parts of cellulose triacetate in a mixture of 5 parts by weight of 2-methyl pentanediol-2,4 and 95 weight parts of methylene chloride, which has a viscosity of about lOOOOOcP at 2O ⁰ C, through a nozzle having 1000 to 2000 openings each 0, 07 mm diameter at a speed of 20 m / min, spun in a 35 ° C warm precipitation bath, which consists of 58.5 parts by weight of 2-methylpentanediol-2,4, 31.5 parts by weight of water and 10.0 parts by weight of methylene chloride. After washing, the threads are cut and dried; they have the following properties: Titer 1.85 den Tensile strength 1.92 g / den Elongation 31.7% Abrasion resistance, bei. 3 Fkm 15,000 tours Loop strength 1.18 g / den Relative loop strength 62 ° / _{0 of} the tear strength Example 2 17.9 parts by weight of cellulose triacetate are in a mixture of 90 parts by weight of methylene chloride and 10 parts by weight of isopropanol dissolved. The solution is at room temperature and a take-off speed of 26 m / min, in a precipitation bath 63 parts by weight of 1-methoxybutanol, 27 parts by weight Water and 10 parts by weight of methylene chloride is spun. The fiber obtained has the following values: Titer 3.52 den Tear strength 1.76 g / den Elongation 34.7 ° / ₀ Shear Strength, At. 3 Fkm 66 500 tours Relative loop strength 55 ° / ₀ of the breaking strength Example 3 A dope of the composition: 14.7 parts by weight of cellulose triacetate, 90 parts by weight of methylene chloride, 5 parts by weight of triethylene glycol, 5 parts by weight of methanol, is made from a nozzle with 48 holes, each 0.07 mm in diameter, into a bath consisting of
70 parts by weight of triethylene glycol,
30 parts by weight of water,
10 parts by weight of methylene chloride,
spun. The take-off speed is 20 m / min., The precipitation bath temperature is 32 ° C. Washed and dried the thread spun in this way has the following properties: Titer 1.17 den Tear strength 2.40 g / den Elongation 23.9% Relative loop strength 47 ° / ₀ of tensile strength
Example 4 17.5 parts by weight of cellulose triacetate are dissolved in a mixture of 95 parts by weight of methylene chloride and 5 parts by weight of methanol. The solution is ^{spun at 32 °} C. in a precipitation bath at a take-off speed of 35 m / min, which consists of 45 parts by weight of ethyl diglycol, 45 parts by weight of water and 10 parts by weight of methylene chloride.
The fiber obtained has the following values Titer 2.32 den Tensile strength 2.14 g / den Elongation 49.3 ° / ₀ Abrasion resistance, bei. 3 Fkm 32,000 tours Relative loop strength 72.5% of the tear strength
Claim: Wet spinning process for producing threads or fibers from cellulose triacetate, characterized in that a homogeneous solution of cellulose triacetate in a mixture of at least 90 _% methylene chloride and monohydric alcohols with 1 to 4 carbon atoms and / or water-soluble glycols with 2 to 6 carbon atoms or mono ethers or polymers of these glycols is spun in a coagulating bath, the water-soluble in a mixture of water, 10 to 15 ° / ₀ MethylenchJorid and at most 70% of glycols with 3 to 6 carbon atoms, or their mono ethers or polymers. Considered publications:
German Patent No. 629 589;
British Patent No. 356,343.