EP0060433A1 - Process for dyeing hydrophobic fibrous material - Google Patents

Abstract

Piece goods made of hydrophobic fibre material can be dyed under HT conditions even with unfinished disperse dyes if under dyeing conditions these dyes are present in a solid form and have a minimum solubility of 1 mg, preferably 5 mg, per litre of dyeing liquor at 130 DEG C, these dyes are introduced directly into the dyebath, and the dyeing machine agitates not only the dyeing liquor but also the material to be dyed (e.g. jet dyeing machines).

Description

Hydrophobic fiber materials, in particular polyester and cellulose triacetate fibers, have hitherto been known to be dyed exclusively with disperse dyes which have previously been subjected to extensive mechanical fine grinding in the presence of dispersants.

It has therefore already been proposed to dispense with this type of formation by simply mixing low-melting dispersion dyes which are liquid under dyeing conditions together with readily biodegradable emulsifiers (cf. DE-OS 2 724 951 = US Pat. No. 4,249,902). However, such dyes are not commercially available and would only have to be obtained by suitable chemical modification of the dyes present. In addition, the emulsifiers to be used are relatively expensive by comparison.

Therefore, it has also been proposed to use unformed, tool-free, preferably commercially available Introducing disperse dyes with a certain minimum solubility into a depot of a circular dyeing apparatus and thus dyeing polyester fibers under HT conditions (cf. EP-OS 00 13 892).

However, this process requires complex changes to existing dyeing machines or the development of new ones. In addition, the procurement of optimally working depots has so far been problematic.

From DE-OS 2 330 622 an isothermal process for dyeing polyester fibers with solutions of low-dispersant or low-disperse disperse dyes has finally become known. Special dyeing apparatuses are also required to carry out this method, since the dye solution must be prepared in a separate vessel and then fed into the actual dyeing bath at the dyeing temperature. Otherwise, only special dyes with relatively good water solubility can be used here, since otherwise the liquor ratio becomes too high.

It has now surprisingly been found that at least piece goods made of hydrophobic fiber materials can be dyed directly with practically unformed disperse dyes in conventional dyeing machines under HT conditions under HT conditions without additional devices, if these dyes are in solid form under dyeing conditions and there is a minimum solubility of 1 mg, preferably 5 mg, per liter of dye liquor at 130 ° C and the dyeing machine is set up so that both the dye liquor and the material to be colored are moved.

In principle, the dyes to be used according to the invention can be used without any aftertreatment, for example in the form of the wet press cake, as is obtained directly in the dye synthesis.

Expediently, however, the dye press cakes are homogenized in a high-speed agitator mill in order to set the type conformity required in practice with the addition of small amounts of adjusting agents and, if appropriate, fed to a spray dryer.

Suitable adjuvants are the conventional auxiliaries which, in contrast to conventional practice, are only added to the dye press cake in amounts of 2 to at most 10 percent by weight (based on pure dye).

“Dyeing conditions” are understood to mean temperatures of 120-150 ° C., pH values 4-7 and liquor ratios from 1: 5 to 1:50.

The liquor circulation should be at least 10 l / min, based on 1 kg of goods.

The minimum solubility of the dyes is a natural upper limit, which results from the dis-. persion dyes usual absence of typical. genuinely solubilizing groups, especially the sulfonic acid groups.

Dyeing machines which meet the requirements according to the invention are, in particular, commercially available jet dyeing machines and high-temperature reel runners with liquor circulation.

Suitable dyeing machines are described in "Encyclopedia of Chemical Technology" by Kirk-Othmer, 2nd edition, volume 8, pages 291-294; in Melliand Textile Reports 12, 1003 ff (1976) and BAYER FARBEN REVUE, No. 25, p. 37 ff (1975). Examples include: Burlington high-temperature reel runners Krantz high-temperature reel runners Spray Jet from S. Pegg &Son; Leicester, (GB) Gaston County Jet Giroflux from Freres, Roanne (FR) Turboflow from Obermeier, Neustadt (DE) Thenjet from Then, Schwäbisch Hall (DE) Aqualuft from Gaston, County (GB) Subtilo from Scholl ( CH) R-Jet 95 from Thies (DE)

The dye is generally introduced into the dyeing liquor in the form of powders, granules or aqueous dispersions at 20-50 ° C., which is then heated to the dyeing temperature together with the piece goods to be colored. The heating time does not need to be controlled.

To achieve true-to-life dyeings, it is advisable to subject the dyed goods to reductive post-treatment. However, due to the lack of the usual dyeing aids and adjusting agents, this post-cleaning can be carried out in the same bath, which is previously cooled to approx. 70 ° C.

• 1) Kosteneinsparung durch Wegfall des Mahlprozesses.
• 2) Hilfsmittel können ganz oder zumindest größtenteils eingespart werden.
• 3) Schaumbildung im Färbebad ist praktisch ausgeschlossen.
• 4) Keine Fleckenbildung auf dem Färbematerial durch Wegfall der sonst üblichen Entschäumungsmittel.
• 5) Bessere Baderschöpfung durch das (fast) vollständige Fehlen von Hilfsmitteln.
• 6) Geringere Abwasserbelastung.
• 7) Verringerte Färbezeiten durch Wegfall der Aufheizsteuerung.
• 8) Einfachere Nachbehandlung.

The new method has compared to dyeing with conventional, dispersant-rich, in bead mills and the like. finely shredded dyes have a number of advantages:

• 1) Cost savings by eliminating the grinding process.
• 2) Aids can be saved completely or at least largely.
• 3) Foam formation in the dye bath is practically impossible.
• 4) No staining on the coloring material due to the elimination of the usual defoaming agents.
• 5) Better bathroom exhaustion due to the (almost) complete lack of aids.
• 6) Lower wastewater pollution.
• 7) Reduced dyeing times by eliminating the heating control.
• 8) Easier post-treatment.

The new method is explained in more detail using the following examples, but without restricting it to them.

example 1

3 g (0.6%) of the only coarsely ground but otherwise not formed disperse dye Disperse Blue 56 (CI 63 285) (water solubility at 130 ° C: 14 mg / 1; mp.> 200 ° C) together with 7 1 cold water and 500 g of textured polyester knitted fabric are placed in a Mathis laboratory jumbo jet and with constant agitation of the fleet at 6 1 / s and a fabric speed of approx. 20 m / min. heated continuously to 130 ° C within 30 minutes. At this temperature, dyeing is continued for a further 50 minutes with constant movement of the liquor and goods, then the mixture is cooled to 70 ° C. in the course of 20 minutes and, after addition of 3 g / 1 sodium hydroxide solution, 38 ° Be and 1.5 g / 1 hydrosulfite for 10 minutes reductively cleaned the same fleet. After the liquor has been drained, it is acidified with 2 - 3 ml of 60% acetic acid and then rinsed cold. After centrifuging, drying and calendering, a full blue color is obtained in 1/1 RTT, which is fuller in color than a 2.2% color with C.I. Disperse Blue 56 is and which does not differ in the known good fastness properties.

If you replace the textured polyester knitted fabric with appropriate amounts of cellulose triacetate fabric and otherwise proceed as described in the example, you will obtain dyeings with the same good result.

Example 2

• a) 37,5 mg (0,0075 %) Disperse Yellow 60 (C.I. 12 712) (Wasserlöslichkeit bei 130°C: 58 mg/l) und
• b) 27,0 mg (0,0054 %) des Farbstoffes der Formel
  
  (Wasserlöslichkeit bei 130°C: 4 mg/l) sowie
• c) 25,5 mg (0,0051 %) Disperse Blue 56 (C.I. 63 285) (siehe Beispiel 1)
  werden unter den gleichen Bedingungen wie in Beispiel 1 beschrieben auf texturiertem Polyestermaterial gefärbt. Nach dem Abkühlen auf 70°C wird die farblose Flotte ohne reduktive Zwischenreinigung der Färbung heiß abgelassen und das Färbegut nach dem Schleudern getrocknet und kalandert.

A dispersion dye combination

• a) 37.5 mg (0.0075%) Disperse Yellow 60 (CI 12 712) (water solubility at 130 ° C: 58 mg / l) and
• b) 27.0 mg (0.0054%) of the dye of the formula
  
  (Water solubility at 130 ° C: 4 mg / l) as well
• c) 25.5 mg (0.0051%) Disperse Blue 56 (CI 63 285) (see Example 1)
  are dyed on textured polyester material under the same conditions as described in Example 1. After cooling to 70 ° C., the colorless liquor is drained off hot without reductive intermediate cleaning of the dyeing, and the material to be washed is dried and calendered after spinning.

You get an absolutely level light gray color with perfect dry and wet rub fastness.

Example 3

• a) 4 g (0,8 %) des Farbstoffs der Formel
  
  (Wasserlöslichkeit bei 130°C: 249 mg/l)
• b) 5,5 g (1,1 %) des Farbstoffs der Formel
  
  Schmelzpunkt: ca. 125°C (Wasserlöslichkeit bei 130°C: 187 mg/l)
• c) 1,25 g (0,25 %) des Farbstoffs der Formel
  
  Schmelzpunkt: ca. 205°C (Wasserlöslichkeit bei 130°C: 5,5 mg/l) wird wie in Beispiel 1 beschrieben gefärbt und nachbehandelt. Man erhält eine gleichmäßige, dunkelbraune Färbung mit ausgezeichneten Echtheiten.

A dispersion dye combination consisting of

• a) 4 g (0.8%) of the dye of the formula
  
  (Water solubility at 130 ° C: 249 mg / l)
• b) 5.5 g (1.1%) of the dye of the formula
  
  Melting point: approx. 125 ° C (water solubility at 130 ° C: 187 mg / l)
• c) 1.25 g (0.25%) of the dye of the formula
  
  Melting point: approx. 205 ° C (water solubility at 130 ° C: 5.5 mg / l) is dyed as described in Example 1 and aftertreated. A uniform, dark brown color with excellent fastness properties is obtained.

If, instead of the dyes or dye combinations mentioned in Examples 1-3, the dyes listed in the following table are used, level dyeings are obtained with otherwise the same procedure, usually with slightly higher color depths than those obtained with finely dispersed dyes with the same dyeing method and raw dye used will..

(RTT = standard depth)

Claims (8)

1. A process for dyeing piece goods from hydrophobic fiber material under HT conditions with non-deformed disperse dyes in the conventional sense, characterized in that a) these dyes are in solid form under dyeing conditions and have a minimum solubility of 1 mg, preferably 5 mg, per liter of dye liquor at 130 ° C., b) these dyes are introduced directly into the dye bath and c) the dyeing machine moves both the dyeing liquor and the material to be colored. 2. The method according to claim 1, characterized in that the dye is used in the form of the wet press cake, as is obtained in the synthesis. 3. The method according to claim 1 and 2, characterized in that the dye is used as the dye by adding a maximum of 10 percent by weight of adjusting agent type press cake, optionally after spray drying. 4. The method according to claim 1, characterized in that the dye is introduced at 20-50 ° C into the dye liquor and this is then heated to the dyeing temperature. 5. The method according to claim 1, characterized in that a jet dyeing machine is used as the dyeing machine. 6. The method according to claim 1, characterized in that the liquor circulation at least 10 1 / min. based on 1 kg of goods. 7. The method according to claim 1, characterized in that the dyed goods are subjected to a reductive aftertreatment and this is carried out in the same dyebath. 8. The textile materials dyed according to claims 1 to 7.