CH672262A5 - - Google Patents

Description

Process for improving the dyeability of textile fibers containing cyan groups with acid dyes

US Pat. No. 2,787,516 describes the treatment of cyanethylated cotton textiles by impregnation with an amine in the liquid phase which contains less than 50% by volume of water, the 5 textiles and the amines at least 5 minutes

Room temperature and normal pressure in touch

to significantly increase tensile strength, elongation and abrasion resistance. These improvements are the swelling and dergi. attributed and are never caused by a chemical reaction. The latter can be recognized by the disappearance of the nitrile absorption band in the infrared and the formation of ammonia, which is due to the formation of the imidazoline ring. In the presence of water, however, a ß-aminoethylamide compound is generated.

French patent 1,027,995 describes the treatment of acrylonitrile polymers with primary aliphatic amines in order to improve the heat resistance and the dyeability with acid dyes. However, the polymers cannot be given a permanent basicity since amine which has penetrated into the fibers easily migrates out again. If the diamine reacts with carboxyl groups formed by hydrolysis of the nitride groups with salt formation, the diamine is also easily washed out by rinsing with water.

The process according to the invention thus surpasses the processes of US Pat. No. 2,707,516 and French Pat. No. 1,027-995 in that it gives the textile fibers permanent basicity by introducing imidazoline residues.

- 3 -

The present invention relates to a process for improving the dyeability of textile fibers containing cyano groups with acid dyes, which is characterized in that 5 the fibers with a lower 1,2-alkylenediamine

The presence of elemental sulfur as a catalyst is implemented in such a way that some of the cyano groups are converted into imidazoline groups.

Compounds 10 which give off elemental sulfur under the reaction conditions can be used as catalysts.

The method according to the invention can be applied, for example, to polyacrylonitrile or cyanoethyl cellulose fibers.

15 The procedure is generally carried out as follows:

The fiber is immersed in the 1,2-diamines, in which a small amount of elemental sulfur or sulfur compound which releases elemental sulfur 20 under the reaction conditions has previously been dissolved, heated to approximately 100 ° C. for a short period of time, washed with water, to remove the 1,2-diamines and then dried. The fiber obtained can be easily dyed with acid dyes.

With this process, however, care must be taken that the long reaction time required for the complete formation of the imidazolines

does not cause the fiber to dissolve in the 1,2-diamines to form polyvinylimidazolines. The polyvinylimidazolines are soluble in water and cannot be converted into the starting substance, namely polyacrylonitrile.

The chemical reaction of the method according to the invention is shown as follows:

V CN n VNH2 NH2 J S wf

^ t I

CH ^ CH-R

Polyvinyl imidazoline

(R: H or lower alkyl)

In addition, the same reaction can be applied to cyanoethyl cellulose fiber to obtain a new cellulose fiber which is easily colored with acid dyes due to the formation of imidazoline groups

- 5 -

Cyano groups in cyanoethyl cellulose. In particular, the paser is treated in the same procedure as in the case of polyacrylonitrile. The imidazoline (2) cellulose fibers thus obtained are lightly dyed with acid dyes. The reaction is shown as follows:

h5n-ch_

2 | 2 -0-CH2CH2CN + H2N-CH

R

"N

1,2-diamine cellulose chain

)

H ylh

- ° 'CH2CH2%

N-

-CH,

I <

-CH Ì

R

Cyanoethyl cellulose

Imidazolinyl (2) cellulose

10 Example 1

0.5 g of polyacrylonitrile fibers (copolymer of 90% acrylonitrile and 10% methyl acrylate) were reacted with 50 g of ethylenediamine in the presence of 0.1 g of elemental sulfur at 60-90 ° C. for 15 minutes in a round bottom flask 15. After that, the fibers were washed with water,

dried, immersed in toluene at room temperature, washed again with water and then dried.

The fibers thus modified were dyed with the acid dye "Solar Brill Scarlet 3R (CIAcid Red 18)" by boiling for 30 minutes at a dye concentration of 2%, based on the weight of the fiber, and a liquor ratio of 1 to 100 . The dye bath was fully drawn out and the light fastness was over 5 degrees. A light fastness of 5 degrees or class 5 means that, compared to unexposed dyed material, practically no fading is found when the dyed material has been exposed in a fade opener for 25 hours.

If the above working catfish was carried out without sulfur, the dyeability of the fiber obtained was only 50%. The dyeability has the value a ^ x 100%,

where a is the concentration of the dye at the start of dyeing and b is the concentration of the dye at the end of dyeing.

Example 2

0.5 g of the polyacrylonitrile fiber used in Example 1 was reacted with 50.0 g of ethylenediamine in the form of a 90% aqueous solution in the presence of 0.1 g of elemental sulfur at 60-90% for 15 minutes.

The fibers thus modified can be dyed with the acid dye "Solar Brill Scarlet 3R (C.I. Acid Red 18)" under conditions similar to those in Example 1; the utilization of the dye bath was 90% and the light fastness was over 5 degrees, i.e. completely unchanged. If no sulfur was added, the dyeability of the fiber was as low as if there was only contamination.

Example 3

Polynosic fibers were immersed in a 1% aqueous sodium hydroxide solution at 20 for 1 hour and squeezed to 100% by weight and then reacted with acrylonitrile at 50 ° C. for 0 minutes. The N content of the cyanoethyl cellulose fibers obtained was 5 %.

10 g of the eyethylated rayon fibers were then reacted with 20 g of ethylenediamine in the presence of 0.1 g of elemental sulfur at 90 ° C. for one minute.

The rayon fibers modified in this way can easily be dyed in a good shade using the acid dye "Du Pont Mill Red SUB". If no sulfur was added in the above process, it was impossible to color the resulting rayon.

Example 4

0.5 g copolymer fiber, which was made from 90 # acrylonitrile and 10% methyl acrylate,

were reacted with 50 g of ethylenediamine and 0.3 g of phosphorus pentasulfide in the liquid state at 60-90 ° C. for 15 minutes while heating. The paser was then washed with water and dried, immersed in toluene at room temperature and washed with water and dried.

The resulting paser showed a 100% dyeability when dyed with the acid dye "Solar Brill Scarlet 3R" 2% (by weight) for 30 minutes with a liquor ratio of 1: 100. In this case, if the phosphorus pentasulfide was not added, the dyeability was only 30% and the light fastness was above class 5.

Example 5

0.5 g of the acrylic fiber used in Example 4 was reacted for 15 minutes with heating to 60-90 ° C. with 50 g of 90% aqueous ethylenediamine solution and 0.3 g of sulfur chloride (SCI or S ^ l ^) in the liquid state and then treated similarly as in Example 4.

The fiber thus obtained showed a dyeability of 90% when a similar dyeing treatment with the acid dye "Solar Brill Scarlet 3Rn" was carried out.

When sulfur chloride was not used, the colorability was as low as if it were only an impurity. The light fastness was above class 5.

Example 6

A strong rayon with high resistance to alkali was immersed in 1 # caustic soda solution at 20 ° C. for one hour and then freed from liquid until the original weight doubled. Then the solution was carried out at 50 × for 30 minutes in acrylonitrile and obtained a cyan ethyl cellulose fiber which had a nitrogen content of 5%.

A fiber obtained by allowing said fiber to react with ethylene diamine at 90 ° C for one hour in the presence of a small amount of phosphorus pentasulfide showed a dyeability in a concentrated shade when dyed with "Du Pont Mill Red SUB" has been. If no phosphorus pentasulfide was used, it was impossible to stain the resulting rayon.

- 10 -

Example 7

0.5 g of polyacrylonitrile fiber obtained by copolymerization of 90% acrylonitrile and 10% methyl acrylate, 40.0 g of propylenediamine and 0.1 g of sulfur were reacted with one another in a similar manner at 60-90 ° for 25 minutes, as in Example 1 described.

The fiber thus obtained can be dyed with the acid dye "Solar Brill Scarlet (C.I. Acid Red 18) under conditions similar to those in Example 1. The dyebath was completely drawn out and the light fastness was above 5 degrees, i.e. completely unchanged.

Example 8

1.0 g of cyanoethylated rayon obtained from polynosian rayon in the same manner as in Example 3 was reacted with 20 g of propylenediamine under the catalytic action of 0.1 g of sulfur at 90 ° C for three minutes and then with water washed.

The rayon obtained showed a dyeability in a concentrated hue when stained with "Du Pont Mill Red SUB".

- 10a -

In the above examples, a large excess of 1,2-alkylenediamines was used, the latter simultaneously serving as solvent and reaction medium, while on an industrial scale corresponding amounts of a non-aqueous solvent,

such as toluene, chlorobenzene or benzene can be used.

- 11 -