DE1217914B - Process for improving the tintability of films or textiles made from hydrophobic polymer resins - Google Patents

Description

Process for improving the dyeability of films or textiles made of hydrophobic polymer resins Hydrophobic polymers of various origins are usually used in the manufacture of shaped objects such as films, tapes, Fibers, hair fibers, yarns, threads and the like, used in the following under particular Consideration of the fibers are treated. Polymers and copolymers from acrylonitrile, the at least about 85 percent by weight of acrylonitrile in the polymer are well suited for these purposes. Difficulties arise, however often when synthetic hydrophobic fibers are to be dyed, especially when they were made from polymers or copolymers of acrylonitrile. This is especially the case when trying to use relatively deep hues to get the finished colored product.

Various methods have been developed to improve colorability of polyacrylonitrile fibers and other synthetic hydrophobic fibers. As far as polyacrylonitrile fibers are concerned, this includes copolymers of acrylonitrile with various monomeric materials that make up the product obtained the mixture of polyacrylonitrile with one or more other dye-affine polymeric substances prior to the formation of one Fiber product and the impregnation of a molded acrylic fiber with a color receptive Means which can be a polymeric material.

These procedures. were not always entirely satisfactory, since many fiber products made in accordance with it often have the physical properties worsen. It is also possible that these products, after they have been manufactured, for many dyes are not absorbent, as the material that increases dyeability, has limited affinity for dyes. It also penetrates in the case of fibers treated in this way. the dye is not always uniform into the whole cross-section of the fiber. Often they take that. Dye only on the outside on. If this is the case - this is called ring coloring -, become with each abrasion of the fiber, as they are regularly in the use of the same Appearance occurs, exposing the uncolored inner parts.

It would be beneficial to have polyacrylonitrile fibers and other hydrophobic ones Synthetic fibers could be treated in such a way that without impairing the physical Properties not only increases the color absorption capacity of the fiber, but also the dye in the whole cross-section of the fiber practically completely and uniformly can penetrate and be absorbed to create deep and lasting colorations with a to obtain a large number of different dyes.

This can be achieved according to the present invention if one a shaped hydrophobic polymer with monomeric vinylpyrrolidone, vinylbenzene-4-sulfonic acid or diallyl glycerol in amounts of 0.5 to 20 percent by weight, based on weight the fiber, and impregnated in the presence of a catalyst and then the impregnated polymerized monomeric substance in situ in the molded polymeric product.

Shaped structures made in this way with color-absorbing components are provided have excellent dyeability. Dyed fiber products match the existing norms for wash resistance and rub resistance and are on the whole Colored cross-section. In the case of the colored products, the wet strength is particularly important much larger than using other methods to improve the dyeability applies. In addition, you need less color-able components in the fiber, in order to achieve a flawless coloring, as if color-absorbing substances on be incorporated into the fiber in another way.

Any shaped hydrophobic polymer can be used in accordance with the present invention be treated, especially those polymers that are essentially Polyacrylonitrile or copolymers made of acrylonitrile with at least 85 percent by weight Are acrylonitrile. The fibers can be used in any desired treatment Are in the state of formation. You can get treated just before or after the fiber is stretched will. In addition, the fiber can be different in the treatment according to the invention Stages of orientation or in a swollen or dried or in a Gel condition. Wet spun fibers are useful after wet drawing when the fiber is in a hydrogel state before being dried.

The monomer can be in any suitable aqueous or non-aqueous Solvents are used while conventional catalysts or catalyst mixtures can be used to polymerize the impregnated monomer.

In most cases it is appropriate to use the monomer from the point of view the special ability to absorb a certain type of dye, which is otherwise have no effect on the respective treated structures. The impregnation of the molded product with monomerization and the subsequent polymerization in situ can take place under very different conditions. Usually it will molded product so long into the the polymerizable substance and the catalyst containing treatment bath immersed until it reaches the desired monomer content Has. The in situ polymerization can then take place after that with the monomer impregnated molded product is taken out of the treatment bath. Polyacrylonitrile fibers z. B. can in a bath with a monomer concentration of 0.5 to 50 percent by weight are impregnated, up to 0.5 to 20 percent by weight monomer, based on the weight the fiber. Usually a treatment bath with a concentration of monomers from 5 to 15 percent by weight to impregnate each fiber with a monomer can be used in an amount of from 5 to 15 percent by weight of the fiber.

The impregnation and subsequent polymerization can be carried out at 0 to 200 ° C. for up to 4 and more hours. A temperature of 50 to 100 ° C. in a time of 15 to 45 minutes is often more advantageous for this purpose, although the most suitable conditions in each case differ depending on the nature of the monomeric substances used.

After the molded product is impregnated with the monomer, the excess monomer can be expressed or otherwise appropriately removed. The treated product can then, after the polymerization has taken place, before it is colored, washed, dried, heat-cured and otherwise treated as desired. Example 1 A 5-part wet-drawn sample of a wet-spun polyacrylonitrile fiber is immersed in an aqueous bath containing, in 94 parts of water, 5.9 parts of vinylpyrrolidone, 0.035 part of 30% aqueous hydrogen peroxide and 0.11 part of concentrated aqueous ammonia. The sample remains in the bath at 75 ° C for 4 hours and is then removed, washed with water, dried, cured at 150 ° C and cleaned. The treated fiber sample is then treated for about 1 hour at boiling temperature in a bath containing 8% CI Acid Black 26 A (CI No. 27 675) [cf. Colono Indix, 2nd edition, 1956], an acidic dye and 15% sodium sulfate and 5% acetic acid, based on the weight of the fiber. The ratio of dye bath to fiber is 30: 1. The dyed fiber is removed from the bath, rinsed thoroughly and dried at 100 ° C. for about 1/2 hour. The fiber has a deep, uniform color which, as microphotographic examination shows, extends over practically the entire cross-section of the fiber.

For comparison, a similar unprocessed sample of a fiber made from a copolymer of acrylonitrile with about 3% vinyl pyridine is dyed in the same way. The result is a much less intense color. A photomicrographic examination of the dyed samples reveals an undesirable ring coloration in the untreated fiber. Example 2 A 5-part wet-drawn sample of a wet-spun polyacrylonitrile fiber is treated by impregnation with vinylpyrrolidone which has been polymerized in situ according to the method given in Example 1. The treated fiber sample is dyed with CI Direct Red 75 (CI No. 25 380), a direct dye, in a dye bath containing 40/0 of the dye and 15010 sodium sulfate, based on the weight of the fiber. The ratio of bath to fiber is 30: 1. The temperature of the dyebath is kept at about 100 ° C., the sample remains in the bath for about 11/2 hours. After dyeing, the fiber is removed from the bath and rinsed thoroughly in water before drying at 100 ° C for about 1/2 hour. The sample is brightly colored over the entire cross-section of the fiber without any noticeable signs of ring coloring.

In contrast, the color was untreated, wet-stretched Inadequate sample of a wet-spun polyacrylonitrile fiber by the same dyeing process. The untreated fiber showed clear signs of ring staining. Example 3 A wet-drawn sample of a wet-spun polyacrylonitrile fiber is with - on based on the weight of the fiber - 15% of a mixture of vinylbenzene-4-sulfonic acid and potassium persulfate impregnated in equal amounts by weight. The impregnated fiber is exposed to water vapor under a pressure of 1.05 kg / cm2 for 30 minutes and then dried, heat treated and cleaned. The treated fiber sample is receptive for C.I. Basie Green 1 (C.I. No. 42040), a basic dye that is deep and penetrates evenly throughout the fiber.

In comparison, take an untreated sample of polyacrylonitrile C. I. Basic Green 1 does not appear to any significant extent.

Example 4 A sample of drawn and dried polyacrylonitrile fiber is placed in a treatment bath, that from 20 parts of vinyl pyrrolidone and 0.2 part of hydrogen peroxide in 150 parts of diethyl ether. After 30 minutes the ether is removed by evaporation at 50 ° C. The impregnated fiber is then Heated to about 120 ° C for 1/2 hour and then to about 150 ° C for 5 minutes. The fiber possesses then excellent dyeability and wash fastness without a tendency to ring staining, when colored with acid, direct, acetate or vat dyes. example Part of a wet-spun, wet-drawn polyacrylonitrile fiber in hydrogel form is immersed for 15 minutes in a treatment bath containing 15 parts of acrylamide and Contains 0.0005 parts of riboflavin in 25 parts of water. After this treatment will the impregnated fiber taken out of the treatment bath to remove the excess fluid expressed and approximately '], for an hour at a distance of about 27.5 cm placed next to a reflective photo special lamp to protect the impregnated Polymerize acrylamide in situ in the fiber by photocatalyst. After completion After the photopolymerization, the treated fiber is dried in the air at 150 ° C heat treated and cleaned. The fiber treated in this way is highly absorbent for both C.I. Disperse Red 7 (C.I. No. 11150) and C.I. Acid Violet 34 (C. I. No. 61710 and 61800) with deep, even tones and more complete Penetration of the fiber.

Claims (3)

Claims: 1. Process for improving the dyeability of Films or textiles made of hydrophobic polymer resins, thereby marked e t that the molded product with monomeric vinylpyrrolidone, vinylbenzene-4-sulfonic acid or diallyl glycerin in amounts of 0.5 to 20 percent by weight based on weight the fiber, and impregnated in the presence of a catalyst and then the impregnated monomeric substance polymerized in situ in the molded product. 2. Procedure according to Claim 1, characterized in that wet-spun polyacrylonitrile fibers in the gel state be treated. 3. The method according to claim 2, characterized in that the Fibers are treated in a partially oriented gel state. Into consideration Extracted publications: German Auslegeschrift No. 1042 520; British patent specification No. 572 959.