GB1587302A

GB1587302A - Process for dyeing synthetic fibrous materials

Info

Publication number: GB1587302A
Application number: GB7450/78A
Authority: GB
Original assignee: Hoechst AG
Current assignee: Hoechst AG
Priority date: 1977-02-26
Filing date: 1978-02-24
Publication date: 1981-04-01
Also published as: BE864351R; DE2708449C3; FR2381862A2; DE2708449A1; DE2708449B2; CH627327B; IT7820636A0; CH627327GA3; IT1113110B

Abstract

Continuous lengths of textiles made of polyester fibres which are dyeable without carriers, and blends of said polyester fibres with natural fibres, are exhaust-dyed at the boil on the beam with aqueous liquors. The liquors contain not only water-insoluble disperse dyes and pH-regulating substances but also, as a dispersing system having a levelling effect, water-soluble linear polyesters which are obtainable by polycondensation of dicarboxylic acids and optionally hydroxycarboxylic acids with diols with the inclusion of sulpho- or sulphonato-containing chain members and in which not more than 40% of the chain members are hydroxycarboxylic acid units, together with surface-active ethoxylation products.

Description

(54) PROCESS FOR DYEING SYNTHETIC FIBROUS MATERIALS (71) We, HOECHST AKTIENGESELLSCHAFT, a body corporate organised according to the laws of the Federal Republic of Germany, of 6230 Frank furt/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 a process for dyeing synthetic fibrous materials, and is an improvement in or modification of the invention which forms the subject of our copending Application No. 48592/77 (Serial No. 1,585,679) which describes and claims a process for dyeing a material containing synthetic fibres alone or together with natural fibers, with one or more water insoluble disperse dyestuffs, which comprises contacting the material with an aqueous dye liquor containing a water-soluble or dispersible linear polyester obtained by poly-condensation of one or more dicarboxylic acids and one or more diols and including sulfo-group-containing units and having an average molecular weight of from 800 to 5*000, and surface active oxethylation products, in a ratio of from 1:0.25 to 1::1.J'. The process is especially applicable to the dyeing of linear polyester fibers and is suitably carried out by the known high-temperature or rapid-dyeing technique, and the dye liquor preferably contains from 0.5 to 3.0 g/l of the polyesters and oxethylation products.

Although the dyeing of the textile piece goods of non-modified linear polyester fibers with disperse dyes by the exhaust technique on dyeing beams at the boiling temperature or under other high temperature conditions with the use of carriers is well known, the dyeing of carrier-free polyester fibers, that is modified fibers which can be dyed with disperse dyes at the boiling temperature without employing dyeing accelerators, involves numerous problems which depend on the processing state of the fiber and on the particular application technique, and which stem especially from the greater affinity and absorption rates of such fiber materials.

In view of the improved affinity of disperse dyes for such modified fibers, care must be taken when dyeing by the exhaust method to ensure that, during heating (of from 70 to 1000 C) of the dyebath and at the beginning of the dyeing process at the boiling temDerature, the fiber surface is contacted with a dye liquor of uniform composition. When dyeing on winches or on jet dyeing apparatus this can be achieved by increasing the feed rate of textile material, and when dyeing on nozzle dyeing appara tus, by increased dyebath circulation. When dyeing yarns on cross-wound packages with alternating dyebath circulation, this requirement is met, in the case of rapidly dyeing fibers, by increasing the rate of flow of the dyebath through the packages to above a certain minimum value ( > 25 I/kg minute).

However, when dyeing piece goods of modified polyester fibers on dyeing beams at the boiling temperature, there are encountered considerable difficulties concerning the levelness of the dyeings. Since the disperse dyes are absorbed by the fibers ex tremely rapidly, it is impossible to avoid the inner layers of the fabric being dyed more intensely than the outer layers when using customary dyebath circulation from the inside to the outside (cf. Chemiefasern/Textilindustrie 26/78 (1976), page-554).

With the use of conventional levelling auxiliaries, only slight and insignificant im provements are obtained.

The process described in our copending Application No. 48592/77 (Serial No.

1,585,679) involves the use of dispersion/levelling system which enables the levelling problems described above to be largely avoided. The present invention is based on the observation that such a dispersion/levelling system can also be used successfully in the dyeing of textile materials containing carrier-free polyester fibers or mixtures thereof with natural fibers at the boiling temperature on dyeing beams. This is especially surprising since carrier-free polyester fibers differ greatly from normal dyeable polyester fibers in their dyeing behaviour owing to their different fiber structure.

The present invention therefore provides a process for dyeing a material containing carrier-free polyester fibers along or together with natural fibers, with one or more water-insoluble disperse dyestuffs at the boiling temperature on beam dyeing apparatus, which comprises contacting the material with a dye liquor containing a water-soluble or dispersible linear polyester obtained by polycondensation of one or more dicarboxylic acids and one or more diols and including sulfo-group-containing units and having an average molecular weight of from 800 to 5,000, and surface-active oxethylation products, in a weight ratio of from 1:0.25 to 1:1.5.

The process according to the present invention enables modified polyester fiber materials to be dyed uniformly even with combinations of three disperse dyes with which level dyeings can generally be obtained only with difficulty. The dispersion/ levelling system is used in an amount of from 2 to 6%, preferably of 5%, calculated on the weight of the material to be dyed. Its presence reduces the dyeing speed to such an extent that the requirement of uniform composition of the dye liquor in the exhaust phase is fulfilled.

It is surprising that under the conditions of the process of the present invention the dye retardation (retardation of absorption) does not result in dye retention over a customary dyeing period. The dye yield is nevertheless practically the same as in other known processes while the levelness is very good and there are obtained acceptable dyeings independently of the goods-to-liquor ratio (1:10 to 1:30).

In principle any carrier-free polyester fibers which are dyeable at the boiling temperature may be used in the process of the present invention for dyeing textile piece goods. Examples are polyester fibers modified with aliphatic dicarboxylic acids, hydroxycarboxylic acids or relatively long chain diols, although polyethylene terephthalate fibers modified with polyethylene oxide in the form of a block copolymer are preferred. For polyester/natural fiber blends, there may be used any fibers of natural origin, specially cellulose fibers or natural wool fibers.

The disperse dyes which are used in the process of the present invention are known azo and anthraquinone dyes, or dyes of the nitro, methine, styryl, quinophthalone, benzthioxanthene or naphthoquinoneimine types, many of which is listed inter alia, in Colour Index, 3rd edition (1971), volume 2.

According to the present invention, there are used as one component of the disparsing agent, polyesters that have been obtained by polycondensation of (a) one or more saturated or unsaturated aliphatic, cycloaliphatic or aromatic dicarb oxylic acids, with (b) one or more saturated or unsaturated aliphatic, cycloaliphatic or aromatic diols, from 5 to 30 ml /O of the dicarboxylic acid units or diol units carrying sulfo groups or the salts thereof.

In these polyesters up to 40% of the units may be hydroxycarboxylic acid units.

Especially preferred are those polyesters which have been prepared from a benzenedicarboxylic acid as the dicarboxylic acid, optionally carrying a sulfo group, and as the prevailing diol component, aliphatic bisalcohols having ether bridges, preferably diethylene glycol or polyethylene glycols.

Preferred dispersing agent components are polyesters of the formula

in which m is zero or 1 and n is an integer such that the average molecular weight of the polyester is from 800 to 5,000, each X is a hydrogen atom or a group of the formula -O-CH2-CH2-CH2-SO,M or -SO3M, and from 5 to 30 mol % of all phenylene nuclei carrying a sulfo-containing group X, M is a hydrogen atom or an alkali metal atom, especially sodium, or an ammonium group or a substituted ammonium group, especially triethylammonium and each R is a radical having of from 2 to 10 carbon atoms, of a saturated or unsaturated aliphatic, cycloaliphatic or aromatic bisalcohol.

Especially preferred polyesters are those of the above formula in which from 10 to 20 mol % of the phenylene groups have been obtained by condensation of dimethyl 5-sodium sulfonato-propoxy-isophthalate or dimethyl 5-sodium-sulfonato-isophthalate, from 40 to 90 mol % by condensation of isophthalic acid or of derivatives thereof, and from 0 to 40 mol% by condensation of terephthalic acid, preferably in the form of its dimethyl ester, and in which from 0 to 95 mol % of the bisalcohol units are derived from diethylene glycol-and from 5 to 40 mol % of the bisalcohol units are derived from one or more other diols, preferably polyethylene glycols having an average molecular weight of from 300 to 1,000.

Another group of preferred water-soluble polyesters are those in which of from 0 to 40 mol % of the benzene-dicarboxylic acid units in the above general formula are replaced by units of an aliphatic or cycloaliphatic dicarboxylic acid having from 4 to 10 carbon atoms.

The surface-active oxethylation products used as dispersing agent component according to the present invention are preferably mixtures of (A) fatty acid polyglycol esters, (B) polyglycol and ;(C) oxethylated alkylaryl compounds, more preferably mixtures of (A) addition products of from 1 to 10 mols of ethylene oxide to 1 mol of a saturated or unsaturated aliphatic carboxylic acid having from 10 to 20 carbon atoms, (B) polyethylene glycols having an average molecular weight of from 300 to 1,000, especially of from 300 to 800 and (C) addition products of from 5 to 1S mols of ethylene oxide to 1 mol of an alkyl phenol having from 12 to 22 carbon atoms.

In general, these mixtures contain component A in an amount which is in excess or about identical to that of component C. The amount of each of components A and C in the mixture is generally of from about 30 to 40 weight %.

According to the process of the present invention, the dispersion system comprising the polyesters and the surface-active oxethylation products may be added to the dyeing liquor as a mixture or the individual components thereof may be added separately.

The following Examples illustrate the invention.

EXAMPLES.

50 kg of a fabric of carrier-free dyeable polyethylene terephthalate fibers modified with polyethylene oxide in the form of a block copolymer were wound on to a perforated dyeing beam with the fabric edges wound accurately one upon the other (thickness of the package about 30% of the diameter of the beam) and were submitted to a dyeing operation in a HT beam dyeing machine with unilateral circulation of the dye bath from the inside to the outside, at 100"C for a period of 60 minutes, with an aqueous liquor which contained, in the quantities given below, a combination of disperse dyes and of a dispersion/levelling system which consisted of 2 parts of a linear, water-soluble polyester of molecular weight 2,500, prepared by polycondensation of isophthalic acid 50 mol % dimethyl terephthalate 40 mol % dimethyl 5-sulfopropoxy-isophthalate 10 mol % diethylene glycol 100 mol % and polyethylene glycol having an average molecular weight of 600 10 mol % and to which 1 part of a non-ionic combination of 40 weight % of the addition product of 6 mols of ethylene oxide and 1 mol of oleic acid 20 weight % of polyethylene glycol having an average molecular weight of 600, and 40 weight % of the addition product of 13 mols of ethylene oxile and 1 mol of tributyl phenol had been added.

EXAMPLE 1.

0.5 weight % of the disperse dye of the formula

0.3 weight % of the disperse dye Disperse Blue 56, C.I. No. 63285, 0.5% by weight of the disperse dye of the formula

0.5% by weight of the dispersion system, which had been adjusted to a pH of 5.5 with acetic acid (at 20"C), goods-to-liquor ratio: 1:15.

EXAMPLE 2.

2% by weight of the disperse dye of the formula

0.5% by weight of the disperse dye Disperse Blue 56, C.I. No. 63285, 5% by weight of the dispersion system, which had been adjusted to a pH of 5.5 with acetic acid (at 20"C), goods-to-liquor ratio: 1:25.

In both cases there were obtained level dyeings showing no tailing with regard to the end and border zones, the attained effect being in the range of from 1:10 to 1:30, independent on the goods-to-liquor ratio.

When using conventional levelling auxiliaries or when not using the dispersion system according to the invention, the shade of the inner layers of the fabric on the dyeing beam was about 20 to 30% deeper than that of the outer layers, even when the rate of flow of the liquor was considerably increased.

WHAT WE CLAIM IS:- 1. A process for dyeing a material containing carrier-free polyester fibers alone or together with natural fibers with one or more water-insoluble disperse dyestuffs at the boiling temperature on beam dyeing apparatus, which comprises contacting the material with a dye liquor containing a water-soluble or -dispersible linear polyester obtained by polycondensation of one or more dicarboxylic acids and one or more diols and including sulfo group-containing units and which have an average molecular weight of from 800 to 5,000, and surface-active oxethylation products, in a weight ratio of from 1:0.25 to 1:1.5.

2. A process according to claim 1, wherein the carrier-free polyester fibers are fibers of a polyethylene terephthalate which has been modified with polyethylene oxide in the form of a block copolymer.

3. A process according to claim 1, wherein the carrier-free polyester fibers are fibers of a polyethylene terephthalate which has been modified with aliphatic dicarboxylic acids.

4. A process according to claim 1, wherein the carrier-free polyester fibers are fibers of a polyethylene terephthalate fiber which has been modified with hydroxycarboxylic acids.

5. A process according to any one of claims 1 to 5, wherein the water-soluble or -dispersible polyester and oxethylation products are present in the dye liquor in a total concentration of from 2 to 6% of the weight cf the material to be dyed.

6. A process according to any one of claims 1 to 5, wherein the water-soluble

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

Claims

**WARNING** start of CLMS field may overlap end of DESC **. EXAMPLE 1. 0.5 weight % of the disperse dye of the formula 0.3 weight % of the disperse dye Disperse Blue 56, C.I. No. 63285, 0.5% by weight of the disperse dye of the formula 0.5% by weight of the dispersion system, which had been adjusted to a pH of 5.5 with acetic acid (at 20"C), goods-to-liquor ratio: 1:15. EXAMPLE 2. 2% by weight of the disperse dye of the formula 0.5% by weight of the disperse dye Disperse Blue 56, C.I. No. 63285, 5% by weight of the dispersion system, which had been adjusted to a pH of 5.5 with acetic acid (at 20"C), goods-to-liquor ratio: 1:25. In both cases there were obtained level dyeings showing no tailing with regard to the end and border zones, the attained effect being in the range of from 1:10 to 1:30, independent on the goods-to-liquor ratio. When using conventional levelling auxiliaries or when not using the dispersion system according to the invention, the shade of the inner layers of the fabric on the dyeing beam was about 20 to 30% deeper than that of the outer layers, even when the rate of flow of the liquor was considerably increased. WHAT WE CLAIM IS:-

1. A process for dyeing a material containing carrier-free polyester fibers alone or together with natural fibers with one or more water-insoluble disperse dyestuffs at the boiling temperature on beam dyeing apparatus, which comprises contacting the material with a dye liquor containing a water-soluble or -dispersible linear polyester obtained by polycondensation of one or more dicarboxylic acids and one or more diols and including sulfo group-containing units and which have an average molecular weight of from 800 to 5,000, and surface-active oxethylation products, in a weight ratio of from 1:0.25 to 1:1.5.

6. A process according to any one of claims 1 to 5, wherein the water-soluble

polyester is as specified in any one of claims 3 to 8 of Application No. 48592/77 (Serial No. 1,585,679).

7. A process according to any one of claims 1 to 6, wherein the oxethylation products are as specified in claim 9 or claim 10 of Application No. 48592/77 (Serial No. 1,585,679).

8. A process according to claim 1 carried out substantially as described in Example 1 or Example 2 herein.

9. A material containing polyester fibers alone or together with natural fibers which has been dyed by a process according to any one of claims 1 to 8.