CA1037657A

CA1037657A - Process for the dyeing of synthetic fibers

Info

Publication number: CA1037657A
Application number: CA192,612A
Authority: CA
Inventors: Albert Reuther; Hans-Joachim Wassmuth; Hans-Ulrich Von Der Eltz
Original assignee: Hoechst AG
Current assignee: Hoechst AG
Priority date: 1973-11-17
Filing date: 1974-02-15
Publication date: 1978-09-05
Also published as: BR7402004A; DK82174A; CS182242B2; GB1465502A; DD109699A5; JPS5747314B2; ZA741008B; IT1002946B; CH217774A4; ES422805A1; SE404042B; FR2251659B1; CH594771B; AT347396B; DE2357447B2; JPS5082383A; BE811108A; FR2251659A1; DE2357447A1; ATA121074A

Abstract

PROCESS FOR THE DYEING OF SYNTHETIC FIBERS

Abstract of the disclosure:
Process for the exhaust dyeing of wound bodies of synthetic fiber materials with water-soluble cationic dyestuffs or anionic dyestuffs, wherein the wound-up textile material is heated to temperatures in the range of from 100° to 120° C in a pressure-tight dyeing vessel by replacing the air in said dyeing vessel by saturated or superheated steam, preparing the total dyebath in a separate batch vessel, which is likewise pressure-tight but connected with said dyeing vessel by pipes, also heating said dyebath to temperatures in the range of from 100° to 120° C.
control is maintained of the temperature within the mentioned limit values , the steam pressure in both closed systems and the application of external pressure securing the building up of a relative excess pressure of 3 to 10 atmospheres gauge in the batch vessel, and the hot dyeing liquor is pressed by the differential pressure within 3 to 60 seconds simultaneously from inside and from outside into the dry or wet wound bodies.

Description

1~376S7 The present inventlon relates to a process for the dyeing of synthe-tic fibers.
Exhaust processes for the dyeing of synthetlc fibers under high tem-perature conditions (HT conditions) on corresponding pressure-tight apparatuses such as HT-Jet-dyeing apparatus, HT-jiggers, HT-winch becks, HT-beam dyeing apparatus and similar apparatus are well known. Depending on the apparatus, on the kind of the fiber and on the dyestuff class, dyeing times of 60 to 180 minutes are generally required in order to control the absorption of the dye-stuffs in such a manner that level dyeings are obtained. Under those thermic conditions of these processes, the affinity of the dyestuffs is strongly in-creased so that long dyeing times are required for levelling.
According to the invent:lon, there is provided in a process ~or th0 dyeing of textile materials made rom synthetic fibers which are dyeable with ionic dyestuffs or from mixtures which contain such synthetic fibers, in the form of wound bodies, with water-soluble cationic or anionic dyestuffs accord-ing to the exhaust method at temperatures in the range of from 100 to 120~C, in which process the wound bodies contained in a pressure-tight dyeing vessel are heated as well as deaerated before the actual dyeing operation and subse-quently contacted with the dyeing liquor which has been separately heated to about dyeing temperature in a pressure-tight batch vessel, placed under a rela-tive excess pressure of from 2.94 to 9.81 bars and then transferred in its total amount from said batch vessel into said dyeing vessel, after both vessels have attained a temperature of 100 to 120C, whereupon the dyeing operation is completed by circulation of the dyeing liquor, the improvement of which com-prises: exposing the wound bodies to an atmosphere of steam at about dyeing temperature prior to contact with the dyeing liquor in order to preheat and deaerate said textile materials and transferring the dyeing liquor within a time of 3 to 60 seconds by means of said relative excess pressure and towards the pressure of the air-free atmosphere of the steam into the dyeing vessel simultaneously from both the inside and the outside of said wound bodies, there-by entirely condensing the steam in said vessel and filling it completely by the transferred liquor.

-2-~37~;iS~

The principle of the present invention consists in that a dyebath is prepared in a HT-vessel under the selected pressure and temperature conditions and is passed from there by means of pressure (pressurized steam, compressed air, pump pressure) into another autoclave filled with steam and containing the wound bodies of synthetic fibers, for example wound up filaments or balls of piece goods on dyeing beams. This is effected by pressing the bath simultane-ously from the outside and from the inside into the wound bodies through cor-respondingly sized tubes, pumps and a distributor valve. This permits uniform distribution of the dyeing liquor in the goods to be dyed within an extremely iO short time, even with strongly crimped polyacrylonitrile fibers or with textur-ized polyamide fibers, without deformation of the wound bodies and filaments.
In general, periods of less than 60 seconds, in most cases even less than 30 seconds, are required. This rapid "shooting in" of the dyebath is achieved by a high pressure from the side of the vessel which contains the dyebath ~pres-sure difference from 3 to 10 atmospheres gauge). The vessel in which the dye-ing operation takes place is previously -! '^

~ - ~

~376~
de-areated and at the same time the goods are pre-heated. The textile material may be dry or pre-washed, which process can be carried out in the dyeing vessel itself.
The dyeing vessel is pressure tight, well isolated and provided with a heat exchanger of high capacity in order to hold the dyeing temper-ature constant.
The bath is heated in the bath vessel to temperatures in the range of from 100 to 120C ~when dyeing polyacrylonitrile and polyurethane fibers not higher than 110C) and then pressed into the dyeing vessel which is filled with steam. Within this process, the dyeing vessel may be fil~ed completely also with closed valve, provided that the corresponding differ-ential pressure is produced~ since the previously present steam is condens-ing with increasing pressure.
~ modification of the process of the invention consists in con-necting the dyeing vessel filled with pressurized steam to a condensation apparatus which may be closed. This, too, enables the formation of a relative pressure difference which makes it possible to completely fill the dyeing vessel with the dyebath with close de-aeration valve.
When the dyeing liquor is in the dyeing vessel, i.e. when "shoot-ing in" is completed, the liquor is pumped with a circulation pump alter-nately from inside to the outside ancl from the outside to the inside through the wound material. The selected dyeing temperature is maintained during this time. Final fixation of the dyestuff generally takes place within a short time. As the absorption speeds are generally high under these temper-ature conditions, i~ is of advantage to operate with sufficiently high out-put of the pump. An output of 40 - 60 l/kg gives a good dyeing result. In the case of dyestuffs or dyestuff combinations which are more difficult to dye level, the output should be higher than 60 gl/kg.
The fact that the total dyeing liquor is introduced with high speed into the dyeing vessel and onto and into the more or less dry material in the form of wound bodies distinguishes it from the hitherto applied high temperature dyeing processes which with all their variants have largely been ~3'76S~7 discussed in literature. Thus, according to the invention, not just a part of the dyeing liquor or a concentrated dyestuff solution is introduced into the dyeing vessel, but the total dyeing liquor is pressed into it suddenly. It was not foreseeablethat under these conditions level dyeings would be obtained, since all cationic dyestuffs and also the acid dyestuffs have an extremely high absorptive power at these temperatures.
In addition, it was not expected that the dyestuff solutions would be suitable for the penetration into wound bodies at such high temperatures and pressure differences owing to the thermic properties of the fibers.
An essential advantage in the process of the invention resides in the fact that the absorptive power of the dyestuffs is fully utilized at the high temperatures used.
The good levelness of the dyeings produced by the process of the invention is obtained by the rapid shooting-in of the dyeing liquor by which it is brought immediately and at any place into contact with the goods;
dyeing is then continued directly with strong circulation of the bath.
Normally, the process described above is carried out in an aqueous medium; however, it may also be applied in the dyeing from organic solvents.
In the latter case, the boiling point which is typical for the respective solvent and the vapour pressure must be taken into consideration for the reaction conditions.
As dyestuffs, there may be used the usual commercial brands of cationic and anionic dyestuffs in powder form or in the form of liquid prep-arations. Such dyestuffs are described in the Colour Index, 3rd Edition, under the class designation "Basic Dyes", "Acid Dyes" or "Reactive Dyes".
For carrying out the process of the invention, all kinds of fibers of synthetic origin in any stage of processing are suitable, which can be dyed according to the HT-dyeing processes with ionic dyestuffs. Among these~
there are to be understood on ~he one hand polyamide, polyurethane, basic modified p~lyester or polyolefin fibers which can be dyed with anionic dye-stuffs such as acid, chromium, metal complex and reactive dyestuffs.

On the other hand, there may also be used polyacrylonitri]e or ~^

~L~33'7~'7 acid modified polyester or other polymeric fibers which can be dyed with cationic (basic) dyestuffs. Preferably, however, the new process is applied to texturated fibers of polyamide, polyacryl and modified polyes~er, since such fibers tend particularly to unlevel dyeings because of their thermic pretreatment during texturation as well as of their high affinity to dye-stuffs.
When dyeing polyacrylonitrile fibers and polyamide fibers, no other additions are necessary except levelling agents and the substances required for adjusting the pH-value. The constancy of the pH-value of the dyebath between p~l 4.5 and 5.5 permits reproducibility of the dyeings and is attained by known suitable buffer systems. The material to be treated may be dry or wet.
For a level dyeing it is important that the circulation of the bath is not interrupted when switching over, which, as is known, may be achieved by a four-way connection or valve control.
The following Examples illustrate the invention:
EXAMPLE 1:
Wound bodies of polyacrylonitrile fibers were introduced into a dyeing vessel suitable for high temperature dyeings. This vessel was de-aerated with saturated steam of 1.2 kp/cm2 and the goods were so preheated.
At the same time, the total quantity of aqueous bath required for the dyeing was prepared in a pressure-tight batch vessel; the quantity of bath amounted to 10 times the weight of the goods and contained 0.5 % of the cationic dyestuff of the formula

3-N~3 N-CH3 C2H5 ~ N=N ~ - N\ ClQ
~ ~=`/ C2H40H
_ Cl CH3 2% of sodium acetate 2.5% of a cation-active retarder on the basis of coconut fat alkyl-dimethyl-benzyl-ammonium chloride and 1 ccm./l of acetic acid ~3~6~7 (60% strength).
An air pressure of 5.5 kp/cm2 was then adjusted above the level of the bath.
The bath under pressure was then heated to 105C. By opening a blocking valve in a suitable distributor line, the heated bath was allowed to enter into the dyeing vessel within 7 to 10 seconds. This secured penetration of the dyebath into the wound bodies from the inside as well as from the outside. After the beginning of the circulation of the bath, a mixed temperature of 102C adjusted. With alternating circulation of the bath, the bath temperature was raised to 105C and the goods were dyed for 30 minutes at this temperature. The dyed material was rinsed hot and cold with water and dried. A level red dyeing was obtained.
When using in the above example instead of the mentioned cationic dyestuff the product Basic Blue 3 (C.l. No. 51004), a level blue dyeing was obtained.
EXAMPLE 2:
Wound bodies of polyacrylonitrile fibers were introduced in a dye-ing vessel suitable for high temperature dyeing. After having closed the vessel, the goods were preheated with saturated steam to 100C and then treated for 10 minutes at 90C with an aqueous bath which contained, refer-red to the weight of the goods, 2.~% of a cation-active retarder on the basis of coconut fat-alkyl-dimethyl-benzyl-ammonium chloride, 2% of sodium acetate and 1 ccm./l of acetic acid (60% strength).
This bath was then pressed by means of compressed air into the batch vessel and combined with 0.9% (referred to the weight of the dry goods) of the cationic dyestuff Basic Red 9 (C.I. No. 42520) and, if necessary, with acetic acid to correct the pH-avlue to 5. A prcssure of 6 kp/cm2 adjusted over the bath with compressed air and the bath so prepared was heated to 105C.
The further treatment for dyeing the goods was effected as ~L~37~iS7 described in Example 1, but with a dyeing time of 20 mlnutes and 105 C.
A level red dyeing was obtained.
EXAMPLE 3:
Yarn wound bodies of polyacrylonitrile fibers and staple fibers in a mixing ratio of 60:40 were dyed according to the method described in Example 1.
A level red dyeing of the polyacrylonitrile portion was obtained.
The cellulose fiber portion could be dyed using suitable dyestuffs, for example direct, reactive, leucovat ester dyestuffs or other dyestufEs, by the one-bath or two-bath method.
EXAMPLE 4:
Yarn wound bodies of polyacrylonitrile fibers and wool in a mixing proportion of 55:~5 were dyed according to the method described :in Example 1 with an aqueous bath which contained, referred to the weight of the goods, 1.5% of the cationic dyestuff of the formula H3C -N~ N-CH3 ~ ~ < ~ / ~2 5 CH3050311~3 2% of sodium acetate and 1 ccm./l of acetic acid (60% strength).
A level bordo dyeing of the polyacrylonitrile portion was obtained.
The wool fiber portion could be dyed using suitable dyestuffs, for example acid, metal complex and reactive dyestuffs, according to the one-bath or two-bath method.
EXAMPLE 5:
Wound bodies of acid modified texturated polyester fibers were introduced into a dyeing vessel suitable for high temperature dyeing. This vessel was then deaerated with saturated steam of 1.25 kp/cm2 and the goods were preheated in this manner. At the same the total quantity oE aqueous dyebath required for dyeing was prepared in a pressure-tight batch vessel;

~L~3~i57 this bath amounted to lOtimes the weight o the goods and contained referred to the weight of the dry goods, 0.2% of the cationic dyestuff sasic Green 4 ~C.I. No. 42000), 1 g/l of a non-ionic dispersing agent on the basis of the reaction product of 1 mole of stearyl alcohol and 25 moles of ethylene oxide, containing 25% of polyethylene glycol of a molecular weight of about 6000, 3 g/l of sodium sulfate, crystallized, 2% of sodium acetate and 2% of acetic acid (60% strength).
The further treatment of the goods was effected as described in Example l; however, the dyebath was shot in at 110 and the goods were dyed for 30 minutes at this temperature.
The aftertreatment of the dyeing was effected by hot intermediate rinsing with water at 90C and then with an aqueous bath which contained 3 g/l of sodium carbonate, anhydrous, 3 g/l of sodium dithionite and 3 g/l of sodium sulfate~ crystallized, for 10 minutes at 85C. Finally, the goods were again rinsed hot and cold with water and dried.
A level green dyeing was obtained.
EXAMPLE 6:
Knit goods of polyacrylonitrile fibers were wound on a dyeing beam, introduced into a dyeing vessel as that described in Example 1 and treated as described in the said Example 1.
A level red dyeing was obtained.
EXAMPLE 7:
Wound bodies of crimp nylon were introduced into a dyeing vessel suitable for high temperature dyeing. This vessel was then deaerated with saturated steam of 1.5 kp/cm and the goods were thus preheated.
At the same time, the total quantity of aqueous bath required for dyeing was prepared in a pressure-tight batch vessel; the quantlty of bath i~'76~
amounted to 10 times the weight of the goods and contained, referred to the weight of the dry goods, 0.6% of the anionic dyestuff Acid Blue 41 ~C.I. No. 62130), 2.5% of the reaction product of 1 mole of cyanuric chloride and 3 moles of metanilic acid, 0.5% of a mixture of 75% of the reaction product of 1 mole of stearyl-amine and 10 moles of ethylene oxide, and 25% of dodecylsulfonic acid, and 0.8% of acetic acid ~60% strength).
A pressure of 5.5 kp/cm2 was produced with compressed air over the bath in the bath vessel.
The bath under pressure was then heated to 115C. Tho bath was transferred by pressure into the dyeing vessel as described in Example l;
at the beginning of the circulation of the bath, a mixed temperature of 110 C
adjusted. The bath temperature was raised to 115C and the material was further treated as described in Example 1, but with a dyeing time of 15 minutes only.
A level blue dyeing was obtained on the polyamide wound bodies.

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. In a process for the dyeing of textile materials made from synthetic fibers which are dyeable with ionic dyestuffs or from mixtures which contain such synthetic fibers, in the form of wound bodies, with water-soluble cationic or anionic dyestuffs according to the exhaust method at temperatures in the range of from 100° to 120°C, in which process the wound bodies contained in a pressure-tight dyeing vessel are heated as well as deaerated before the actual dyeing operation and subsequently contacted with the dyeing liquor which has been separately heated to about dyeing temperature in a pressure-tight batch vessel, placed under a relative excess pressure of from 2.94 to 9.81 bars and then transferred in its total amount from said batch vessel into said dyeing vessel, after both vessels have attained a temperature of 100° to 120°C, where-upon the dyeing operation is completed by circulation of the dyeing liquor, the improvement of which comprises: exposing the wound bodies to an atmosphere of steam at about dyeing temperature prior to contact with the dyeing liquor in order to preheat and deaerate said textile materials and transferring the dyeing liquor within a time of 3 to 60 seconds by means of said relative excess pressure and towards the pressure of the air-free atmosphere of the steam into the dyeing vessel simultaneously from both the inside and the outside of said wound bodies, thereby entirely condensing the steam in said vessel and filling it completely by the transferred liquor.

2. A process as claimed in claim 1, wherein the relative excess pressure for transporting the dyeing liquor from the batch vessel into the dyeing vessel is produced by compressed air.

3. A process as claimed in claim 1, wherein prior to the shooting in of the dyeing liquor the dyeing vessel is rinsed, deaerated, filled and preheated with the goods with compressed steam.

4. A process as claimed in claim 1, wherein the wound bodies are exposed to an atmosphere of saturated steam, and in which for increasing the relative excess pressure the dyeing vessel is connected with a condensation line that may be closed.

5. A process as claimed in claim 1, wherein polyamide, polyurethane, basic modified polyester or polyolefin fibers, which can be dyed with anionic acid, chromium, metal complex and reactive dyestuffs, are used as synthetic fibers.

6. A process as claimed in claim 1, wherein the synthetic fibers are polyacrylonitrile or acid modified polyester or other polymeric fibers which can be dyed with cationic (basic) dyestuffs.