GB1579478A

GB1579478A - Process for dyeing blended fabrics comprising polyester fibres and wool and/or other polyamide fibres

Info

Publication number: GB1579478A
Application number: GB53278/77A
Authority: GB
Original assignee: Hoechst AG
Current assignee: Hoechst AG
Priority date: 1976-12-22
Filing date: 1977-12-21
Publication date: 1980-11-19
Also published as: BE862180A; FR2375387B1; DE2658063B1; DE2658063C2; IT1089980B; FR2375387A1; JPS5378382A; CH634710GA3

Abstract

The invention relates to a pad-hot batch-thermofix process for the single-bath dyeing of polyester/polyamide blends with disperse and wool dyes. The textile material is padded from a weakly acid medium with an aqueous liquor that contains both classes of dyes, and the moist impregnation is batched at 85 to 107 DEG C for 15 to 60 minutes and then heated without drying at 160 to 185 DEG C for 60 to 120 seconds to effect thermosoling. The polyester fibre component used comprises carrierlessly dyeable fibres composed of polyethylene terephthalate modified with hydroxycarboxylic acids or aliphatic dicarboxylic acids or composed of polyethylene terephthalate modified with polyethylene oxide in the form of a block copolymer. Wool does not suffer any damage under these fixing conditions.

Description

(54) PROCESS FOR DYEING BLENDED FABRICS COMPRISING MODIFIED POLYESTER FIBRES AND WOOL AND/OR OTHER POLYAMIDE FIBRES (71) We, HOECHST AKTIENGESELLSCHAFT, a body corporate organised according to the laws of the Federal Republic of Germany, of 6230 Frankfurt/Main 80, Postfach 80 03 20, Federal Republic of Germany, do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- This invention relates to the dyeing of blended fabrics comprising polyester fibres and wool and/or other polyamide fibres.

In practice this dyeing has hitherto been carried out mainly by the exhaust process, either in one bath or in two different dyeing baths; continuous and semicontinuous processes are too troublesome owing to the pronounced dyeing differences of the participating fibre components and the sensitivity of the wool.

For example, there is the risk, especially when using thermosoling temperatures, of the formation of frosting on the goods, and the wool tips are consequently not dyed. This disadvantage may be overcome in accordance with the method described in German Patent Specification No. 1 769 647 by means of textile auxiliaries in combination with a specific proportion of moisture and air in the thermosoling process. However even in this process more or less pronounced damage to the wool cannot be avoided because temperatures of 200"C and above are still necessary in order to fix the disperse dyestuffs in the polyester fiber. It is in this temperature range that damage to the wool begins. The result in practice is that the wool yellows, whilst at the same time the cystine bridges are split. The result is losses in quality.Temperatures even a little below the temperature range hitherto customary for thermosoling impair the quality of the wool to a much lesser extent.

In practice, therefore, there have always been objections to the thermosoling method when wool is exposed to such a heat treatment. In addition, the desirability of using the large quantity of auxiliaries necessary here is very questionable in view of the increased price of the dyeing process and the contamination of the waste water with these auxiliaries. Finally, the use of this method on polyester fiber and wool mixtures is very complicated and laborious when two separate methods have to be performed to dye the two fibre components.

There is therefore a need for a process whereby polyester fibre and wool mixtures can be dyed in one bath without damage to the wool by heat.

We have found that the above disadvantages can be substantially avoided by using in these fibre mixtures, instead of "normal" dyeable polyester fibres, modified polyester fibres that can be dyed at boiling temperature without the use of carriers.

The present invention provides a process for dyeing in one bath blended fabrics comprising polyester fibres and of wool and/or other polyamide fibres, with one or more disperse dyestuffs and one or more dyestuffs suitable for dyeing the wool and/or other polyamide fibres in accordance with a padding/heat dwelling/thermofixing process, which comprises impregnating the textile material with an aqueous weakly acidic dyeing liquor containing the dyestuffs of the two classes, allowing the material to dwell in the moist state, e.g. for 15 to 60 minutes, at a temperature in the range of from 85 to 1070C, and then, without prior intermediate drying, heating the textile to a temperature in the range of from 160 to 1850C and thermosoling directly for 60 to 120 seconds at a temperature in this range, and wherein the polyester fibres are carrier-free dyeable fibres of polyethylene terephthalate modified with a hydroxycarboxylic acid and/or an aliphatic dicarboxylic acid and/or of polyethylene terephthalate modified with polyethylene oxide in the form of a block copolymer.

For impregnation, the dyeing liquor is advantageously either applied hot to the fibrous material or heated on the material to 85 to 1070C by infra-red treatment.

In the heat treatment step at 85 to 107"C it is unimportant in what form the padded material is allowed to dwell in the thermo-chamber. For example, it may be wound up or plaited down or hung in loops. In the case of plaiting down, the material is advantageously transported by a sieve web, and in the case of the suspended loop system, by advancing the carrier rods. In this manner a continuous dyeing process is possible if the thermo-chamber has a large capacity. In any case a careful and simple dyeing process may be effected without great expenditure of time.

The dwelling step may be carried out under HT conditions, in so far as these are applied for wool, for example at a temperature of from 100 to 1070C; the time is thereby shortened.

As will be appreciated by a man skilled in the art, the time for which the material is allowed to dwell at a temperature of from 85 to 1070C should be sufficiently long to produce a satisfactory final dyeing and will depend on the temperature selected and other factors. Usually the time is no more than 60 minutes, advantageously 15 to 60 minutes. The expert would have no difficulty in ascertaining the optimum time or range of times for a particular process.

Preferably, the temperature in the dwelling step is from 95 to 1050C.

In accordance with the invention, the drying and thermofixing are effected in one operating step. The prefixing of the woven fabric and the matching off, which generally have to be carried out in the dye works when the exhaust process is used, are thus superseded.

In the thermosoling step, steam may if desired be blown in.

In comparison with the conventional methods in this field, the process of the present invention has a number of advantages that makes it a dyeing process of great practical interest. In comparison with the hitherto known dyeing techniques, less energy needs to be used in the method described herein to obtain a full dyeing.

Since in the thermosoling step temperatures of only approximately 160 to 1800C are necessary, the process of the present invention is especially suitable for the wool fibres: under these conditions the wool fibre is not damaged especially since a part of the thermofixing is a type of steaming process as there is no intermediate drying. With this process it is possible to avoid losses in quality of the wool fibre which could not be overcome hitherto, and this can be seen quite easily by means of colour reactions. On account of its simplicity, the process of the present invention affords a much more reliable dyeing of polyester fibre/wool mixtures.

Moreover, the process of the invention is not harmful to the environment since it is no longer necessary to use a large number of textile auxiliaries, and furthermore not inconsiderable quantities of water can be saved.

The components mixed with the modified polyester fibres may be fibres of any one or more polyamide, but preferably comprises natural wool fibres. The polyester may be a polyethylene terephthalate modified by a polyethylene oxide block copolymer and/or hydroxycarboxylic acid or aliphatic dicarboxylic acid or by two or more such acids. The polyester fibres may be fibres of one or more of these polyethylene terephthalates. Because of the use of these modified polyester fibres, the dyeing of blended fabrics consisting of polyester and wool fibres has become of interest for the first time, since by the padding-warm dwell-hot fixing process according to the invention level dyeings on material with satisfactory feel and satisfactory final properties can be obtained.

The process of the present invention uses one or more disperse dyestuffs and one or more polyamide dyestuffs.

Suitable disperse dyestuffs are, for example, known compounds from the azo series and anthraquinone series, or, for example, of the nitro-, methine-, styryl-, quinophthalone-, benzothioxanthene or naphthoquinone imine type, as quoted to some extent inter alia in the Colour Index, 3rd Edition (1971), volume 2.

The acid and metal complex dyestuffs suitable for dyeing the polyamide fibre constituent e.g. wool in the mentioned fibre mixtures are well known to the expert as wool dyestuffs and are described in the Colour Index (3rd Edition 1971, Volume 5). It is also possible to use reactive dyestuffs, for example those known from German Patent Specification No. 2 047 832.

Special dyestuff mixtures of disperse and acid dyestuffs specified in German Patent Specification No. 2 108 364, may also be used.

The following Examples illustrate the invention.

Example I A gaberdine blended fabric consisting of 55van fibres of polyethyleneterephthalate/polyethylene oxide block copolymer and 45 wool was padded at a liquor pickup of 70% (of the weight of the dry material) with an aqueous padding liquor, heated to 700 C, which contained per litre: 15 g of the red disperse dyestuff of the formula

0.62 g of the yellow disperse dyestuff Disperse Yellow 64, Colour Index No. 47 023 1.8 g of the yellow disperse dyestuff Disperse Yellow 5, Colour Index No. 12 790 5 g of red reactive dyestuff of the formula

4.3 g of the yellow reactive dyestuff of the formula

(in commercial composition and form) as well as:: 5 g of a non-ionic auxiliary based on the reaction product of 1 mole of isotri decyl alcohol with 8 moles of ethylene oxide, 5 g of a non-ionic thickener based on fully etherified carob bean flour, 5 cm3 of formic acid (85% strength) and 10 g of sodium acetate.

After padding, the material was heated to 1000 C, in an infra-red chamber, introduced into a dwell chamber and allowed to dwell there for 15 minutes at 100"C. The material, which was still moist, was then thermosoled in a thermosoling unit for 90 seconds at 1800C. The dyeing so produced was subsequently rinsed with water. The after-treatment was carried out for 15 minutes at 850C with an aqueous bath containing: 2 cm3/l of ammonia (25 /n strength) and 5 g/l of an auxiliary mixture consisting of 500% by weight of the reaction product of I mole of castor oil with 36 moles of ethylene oxide, 350% by weight of the calcium salt of tetrapropylenesulphonic acid and 15% by weight of isobutanol.

A uniform scarlet dyeing of the gaberdine blended fabric with a good solid shade for both fibre constituents was obtained.

Example 2 A blended fabric consisting of 55% fibres of a polyethylene terephthalate/polyethylene oxide block copolymer and 45% wool was padded at 800C with an aqueous liquor which contained the following additives: 16.8 g/l of the disperse dyestuff of the formula

3 g/l of the disperse dyestuff Disperse Blue 56, Colour Index No. 63 285, 2.1 g/l of the disperse dyestuff of the formula

1 g of the disperse dyestuff Disperse Yellow 64, Colour Index No. 47 023 and 7.1 g of the 1:2 chromium complex compound consisting of the dyestuffs of the formula

(the dyestuffs are in commercial composition and form) as well as:: 60 g/l of urea, 5 cm3/l of formic acid (85% strength), 5 g/l of a non-ionic auxiliary based on the reaction product of 1 mole of isotri decyl alcohol with 8 moles of ethylene oxide, and 5 g/l of a fully etherified carob bean flour as non-ionic thickener.

The liquor pick-up in the padding process was 80% (of the weight of dry material). The padded material was then heated to 1020C in a steam chamber and then allowed to dwell in a dwell chamber for 30 minutes at 1020C. Immediately after removing from the dwell chamber, the still moist textile material was thermosoled for 90 seconds at 160"C and subsequently rinsed with water. The after-treatment was carried out for 15 minutes at 700C with an aqueous bath containing: 2 cm3/l of acetic acid (60% strength) and 3 cm3/l of an auxiliary mixture consisting of 50% by weight of the reaction product of 1 mole of castor oil with 36 moles of ethylene oxide, 33% by weight of the calcium salt of tetrapropylenesulphonic acid and 15% by weight of isobutanol.

A good strong solid navy blue dyeing with good fastness properties was obtained.

Example 3 A fabric consisting of 55% of fibres of polyethylene terephthalate/polyethylene oxide block copolymer and 45% wool was padded at a liquor pick-up of 75% (of the weight of the dry material) with an aqueous liquor heated to 800 C, containing: 26.4 g/l of the disperse dyestuff of the formula

0.3 g/l of the disperse dyestuff Disperse Blue 56, Colour Index No. 63 285 8 gIl of the acid dyestuff Acid Red 154, Colour Index No. 24 800, 5 gIl of a non-ionic auxiliary based on the reaction product of 1 mole of isotri decyl alcohol with 8 moles of ethylene oxide, 5 g/l of a nonionic auxiliary based on fully etherified carob bean flour, 60 gIl of urea and 5 cm/l of formic acid (85% strength) and was left to dwell for 30 minutes at 950C in a pad-roll unit. After this dwell period, the textile material was thermosoled for 90 seconds at 1800C without previous interim drying and was then rinsed with water.The after-treatment for the dyeing was carried out for 10 minutes at 700C with an aqueous bath containing: 2 cm3/l of acetic acid (60 /n strength) and 3 g/l of an auxiliary mixture consisting of 50% by weight of the reaction product of 1 mole of castor oil with 8 moles of ethylene oxide, 35% by weight of the calcium salt of tetrapropylenesulphonic acid and 15% by weight of isobutanol.

A strong even Bordeaux red dyeing of the blended fabric with a good solid covering of both fibre constituents was obtained.

WHAT WE CLAIM IS: 1. A process for dyeing in one bath blended fabrics comprising polyester fibres and wool and/or other polyamide fibres, with one or more disperse dyestuffs and one or more dyestuffs suitable for dyeing the wool and/or other polyamide fibres in accordance with a padding/heat dwelling/thermofixing process, wherein the textile material is impregnated with an aqueous weakly acidic dyeing liquor containing the dyestuffs of the two classes, then the material is allowed to dwell in the moist state at a temperature in the range of from 85 to 1070C, then, without prior intermediate drying, heated to a temperature in the range of from 160 to 1850C and directly thermosoled for 60 to 120 seconds in this temperature range, and wherein the polyester fibres are carrier-free dyeable fibres of polyethylene terephthalate modified with a hydroxycarboxylic acid and/or an aliphatic dicarboxylic acid and/or of polyethylene terephthalate modified with polyethylene oxide in the form of a block copolymer.

2. A process as claimed in claim 1, wherein the dwelling time is from 15 to 60 minutes.

3. A process as claimed in claim 1 or claim 2, wherein the dwell temperature is from 95 to 1050C.

4. A process as claimed in any one of claims I to 3, wherein steam is blown in during the thermosoling treatment.

5. A process as claimed in claim 1, carried out substantially as described herein.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. 33% by weight of the calcium salt of tetrapropylenesulphonic acid and 15% by weight of isobutanol. A good strong solid navy blue dyeing with good fastness properties was obtained. Example 3 A fabric consisting of 55% of fibres of polyethylene terephthalate/polyethylene oxide block copolymer and 45% wool was padded at a liquor pick-up of 75% (of the weight of the dry material) with an aqueous liquor heated to 800 C, containing: 26.4 g/l of the disperse dyestuff of the formula 0.3 g/l of the disperse dyestuff Disperse Blue 56, Colour Index No. 63 285 8 gIl of the acid dyestuff Acid Red 154, Colour Index No. 24 800, 5 gIl of a non-ionic auxiliary based on the reaction product of 1 mole of isotri decyl alcohol with 8 moles of ethylene oxide, 5 g/l of a nonionic auxiliary based on fully etherified carob bean flour, 60 gIl of urea and 5 cm/l of formic acid (85% strength) and was left to dwell for 30 minutes at 950C in a pad-roll unit. After this dwell period, the textile material was thermosoled for 90 seconds at 1800C without previous interim drying and was then rinsed with water.The after-treatment for the dyeing was carried out for 10 minutes at 700C with an aqueous bath containing: 2 cm3/l of acetic acid (60 /n strength) and 3 g/l of an auxiliary mixture consisting of 50% by weight of the reaction product of 1 mole of castor oil with 8 moles of ethylene oxide, 35% by weight of the calcium salt of tetrapropylenesulphonic acid and 15% by weight of isobutanol. A strong even Bordeaux red dyeing of the blended fabric with a good solid covering of both fibre constituents was obtained. WHAT WE CLAIM IS:

1. A process for dyeing in one bath blended fabrics comprising polyester fibres and wool and/or other polyamide fibres, with one or more disperse dyestuffs and one or more dyestuffs suitable for dyeing the wool and/or other polyamide fibres in accordance with a padding/heat dwelling/thermofixing process, wherein the textile material is impregnated with an aqueous weakly acidic dyeing liquor containing the dyestuffs of the two classes, then the material is allowed to dwell in the moist state at a temperature in the range of from 85 to 1070C, then, without prior intermediate drying, heated to a temperature in the range of from 160 to 1850C and directly thermosoled for 60 to 120 seconds in this temperature range, and wherein the polyester fibres are carrier-free dyeable fibres of polyethylene terephthalate modified with a hydroxycarboxylic acid and/or an aliphatic dicarboxylic acid and/or of polyethylene terephthalate modified with polyethylene oxide in the form of a block copolymer.

6. A process as claimed in claim 1, carried out substantially as described in any

one of the Examples 1 to 3 herein.

7. A blended fabric comprising modified polyester fibres as specified in claim 1 and wool and/or other polyamide fibres which have been dyed by a process as claimed in any one of claims 1 to 6.