DE3801112A1 - Process for dyeing cellulose fibre materials - Google Patents

Abstract

Cellulose material is dyed with reactive dyes from electrolyte-containing baths by the exhaust method by starting the dyeing at between pH 6 and pH 8.5 and completing it at between pH 10 and pH 12 and raising the pH during the dyeing by at least 2 pH units by linear metered addition of a solution of alkali at the fixing temperature. In addition, the dyebath already contains, before the start of the metered addition of alkali, a buffer which is active in the alkaline pH region. The metered addition of the alkali solution is controlled in such a way that pH 9 is not exceeded within 15 minutes from the start of the metered addition.

Description

The present invention relates to a method for level, reproducible and automatable dyeing of cellulose fiber material with alkaline fixing Reactive dyes from electrolytic dye baths at 40 to 80 ° C using the pull-out method, in particular for dyeing on dyeing units with liquor circulation and dosing device.

Dyeing cellulosic fiber materials such as cotton, Cotton wool materials and linen are made dependent on the reactivity of the dye used from 5 to 100 g / l sodium sulfate or table salt containing alkaline dye baths, which have a pH Show values from 7 to 12.0 at 40 to 100 ° C.

A basic distinction is made with regard to process control two principles to make the dyeing process so shape that a level, d. H. evenly stained Textile material is obtained.  

One method is based on a lower one Temperature than the optimal fixing temperature, adds dye, salt and the necessary for fixation Add alkali to the dyebath and slowly heat to fix temperature.

The other method uses the dye and salt containing dyebath the fixative alkali only when increased Fixing temperature added. Although cellulose fiber materials better movement of goods at higher temperatures in the machine and thus better laying of wrinkles means adding alkali Fixing temperature a sudden increase in the fixing pH, which often leads to a strong unegality of the generated coloring leads. It is therefore the most diverse Working methods have been developed to make a sudden Avoid fixing.

In US-A 43 72 744 a method is described in which is the proportion of fiber-reactive available for fixation Dye in the dye bath below one for the sudden course of the reaction necessary limit is maintained by continuously adjusting the pH increases from 7 to 12, so that during the temporal Only part of the dyeing process reacts and thus always a mechanical installation problem in an irrelevance irrelevant to the overall color can have an impact.  

In EP-A 01 26 042 a method is described in which the alkali required for fixation Fixing temperature continuously added progressively becomes. This procedure is based on the assumption that the Fixation of the reactive dye only from the progression depends on the addition function of a given amount of alkali and that the pH of a reactive dye bath itself is neither for the fixation of meaning still accurate at all is measurable.

A method for dyeing cellulosic materials has now been found from electrolyte-containing baths with reactive dyes found by the pull-out method, in which the Initial pH of the dyebath at 6 to 8.5 and the final pH is 10 to 12 and at which the pH during Coloring by linear addition of alkali by at least is increased two units and this is characterized is that the dye bath before the start of the Adding alkali is effective in the alkaline range Contains buffer.

The addition of alkali can be continuous or intermittent, d. H. with interruptions. Preferably it is controlled so that within 10 to 15 minutes after the start of alkali dosing pH 9 not is exceeded.

In the reactive dyeing process, one of the color depths of the Coloring dependent amount of alkali consumed directly. The So pH is the most important parameter for yourself  playing chemical reaction and controlling the pH curve, especially at the beginning of the fixation process it can be used as a new way of automation and implementation an all-color reactive dyeing process.

The time course of the pH curve so aimed is aimed the speed of circulation of the fleet in the dyeing machine. As a rule, the pH Increase from 8 to 8.5 to 10.5 to 12 at a time from 30 to 120 minutes, preferably to 45 to 75 minutes. The final pH is free and, depending on the dyeing temperature, Color depth and reactivity of the dye used take any values. It is generally included 10.5 to 12, preferably 10.8 to 11.5.

The course of the pH curve can be at the beginning of the fixation process be steeper than at the end until a constant pH Level is reached at which the for the dyeing process permissible maximum fixing speed has been reached.

By interrupting the alkali metering then set a buffered pH level.

In this case, only as much alkali is dosed first in the dyeing liquor that that caused by the fixation Alkaline consumption is compensated and the buffer prevents the pH from falling.  

Buffer substances are suitable for the process Sodium acetate / acetic acid, sodium or potassium carbonate, Mono- or disodium phosphate or their mixtures as well Sodium borate or boric acid-sodium borate mixtures in Consider. The application amounts are 0.1 to 2 g / l, preferably at 0.25 to 0.75 g / l dyeing liquor.

Sodium hydroxide solution and potassium hydroxide solution in particular come as alkali or soda solution (concentration about 10 to 50%) in Question.

The alkali is generally dem at the fixing temperature Dye bath which contains the material to be colored, dye, Electrolyte, especially NaCl or Na₂SO₄, buffer and optionally contains other auxiliaries, generally over a period of about 30 to 120 minutes, preferably 45 to 75 minutes.

All alkaline fixable, water-soluble reactive dyes in question, for example those of the azo, anthraquinone, phthalocyanine, Formazan or triphendioxazine series, especially those with heterocyclic reactive group or halotriazinyl or halopyrimidinyl reactive group or aliphatic Reactive group or sulfatoethylsulfonyl or Vinyl sulfone group.

The method is preferably suitable for dyeing with Dyes containing a monofluorotriazinyl, a 2,6-di fluoro-5-chloropyrimidinyl- or 2,3-dichlorodoxaline-6- contain carbonyl reactive group.  

Example 1

100 parts of a bleached cotton jersey material are on a linear dosing pump provided jet dyeing machine with 1000 parts of one 50 ° C warm aqueous liquor of pH 7 treated, the 2nd Contains parts of the dye I. After 5 minutes divided the bath into 3 portions, 50 parts of table salt and 1 part of Na bicarbonate added. This sets in pH of 8.2 a (measured at room temperature).

After 30 minutes of treatment under these conditions then on the suction side of the main circulation pump With the help of a linearly working alkali metering pump Dilute caustic soda for 60 minutes in the circulating Dye liquor stream injected, the pH the dye liquor rises to 11.0 during this time.

After the final pH value has been reached, the coloring continues 10 minutes at the same temperature. Subsequently is examined, the exhausted fleet is drained, twice cold, rinsed twice at 80 ° C and 10 as usual Soaped for a few minutes. One obtains in high fixation yield a level red color.  

Example 2

100 parts of a mercerized cotton yarn are opened a yarn dyeing device 15 provided with a metering pump Minutes with 600 parts of a 50 ° C aqueous liquor treated which 2 parts of dye II, 30 parts Table salt and 1 part of monosodium phosphate. Subsequently are at this temperature with the help of a Piston metering pump from an additional vessel for 45 minutes dilute sodium hydroxide solution pumped in evenly, so that the pH of the dye liquor begins at pH 6.5 and has a pH rise ending at pH 11.5. At When pH 11.5 is reached, the alkali metering is switched off. After completing the dosing process, this will be Cotton yarn to complete the dyeing another 15 Treated minutes at 50 ° C. After this time it is patterned the remaining liquor drained and the dyeing rinsed and then soaped at the boil as usual. You get a level dyed-through spool with a deep blue color high fixation yield.  

Example 3

100 parts of a mercerized cotton material on a jet dyeing machine with 750 parts at 50 ° C warm aqueous fleet of softened process water an original hardness of 16 ° DH and a measured pH treated by 6.2, which

0.4 parts sodium borate,
0.4 parts boric acid,
30 parts of table salt,
0.175 parts of dye III
0.987 parts of dye IV and
0.048 parts of dye V

contains.

After 5 minutes of treatment in these conditions diluted to 1:50 over a period of 75 minutes 45% sodium hydroxide solution pumped in linearly. The pH of the Dye bath corresponds to pH 9 after 27 minutes and after 54 minutes pH 10, after 67 minutes pH 11 and after 75 minutes pH 11.5. After reaching pH 11.5, the coloring treated for a further 10 minutes at this pH, then drained the exhausted fleet twice rinsed cold at 20 ° C and twice warm at 80 ° C and 15 Minutes soaped at the boil and rinsed cold. You get fully automatic, level browning with high yield.  

Formula scheme for the above-mentioned dye individuals.

Claims (8)

1. A method for dyeing cellulose material with reactive dyes from electrolyte-containing baths by the exhaust method, in which the dyeing is started at a pH between 6 and 8.5 and ended at a pH between 10 and 12, and in which during the Coloring the pH value by linear addition of an alkali solution at fixing temperature is increased by at least 2 pH value units, characterized in that the dye bath contains a buffer which is effective in the alkaline pH range even before the alkali addition is started. 2. The method according to claim 1, characterized in that that the alkali solution is continuous is metered. 3. The method according to claim 1, characterized in that the addition of the alkali solution intermittent. 4. The method according to claims 1 to 3, characterized characterized in that it was diluted as an alkali solution Sodium hydroxide solution used. 5. The method according to claims 1 to 3, characterized characterized in that it was diluted as an alkali solution Soda solution used.   6. The method according to claims 1 to 5, characterized characterized in that the buffer is monosodium carbonate used. 7. The method according to claims 1 to 5, characterized characterized in that the buffer is monosodium phosphate used. 8. The method according to claims 1 to 7, characterized in that 0.1 to 2 g / l buffer are used.