GB2035387A

GB2035387A - Process for dyeing polyacrylonitrile fibres

Info

Publication number: GB2035387A
Application number: GB7937798A
Authority: GB
Original assignee: Ciba Geigy AG
Current assignee: Novartis AG
Priority date: 1978-11-02
Filing date: 1979-10-31
Publication date: 1980-06-18
Also published as: JPS5567081A; DE2943750A1; FR2440434A1; IT7950712A0

Abstract

A process for dyeing polyacrylonitrile fibre material to obtain level dyeings of good penetration and excellent fastness properties consists in dyeing the fibre material with an aqueous dyebath which contains at least one migrating cationic dye and at least one quaternary compound of the formula <IMAGE> wherein R is an aliphatic hydrocarbon radical containing 6 to 22 carbon atoms or a cycloaliphatic radical of 5 to 12 carbon atoms, each of X1 and X2 is methyl or ethyl or together with the nitrogen atom to which they are attached are a 5- to 6-membered saturated heterocyclic radical, X3 is lower alkyl, hydroxy-lower alkyl or cyano- lower alkyl, and An<(-)> is an anion of an organic or inorganic acid.

Description

SPECIFICATION Process for dyeing polyacrylonitrile fibres The present invention relates to a process for dyeing polyacrylonitrile fibres with migrating cationic dyes.

The cationic dyes specially developed for dyeing polyacrylonitrile fibres are distinguished in general by very good exhaustion properties and build-up, excellent fastness characteristics, and by brilliant shades. As against this, their migration properties on most polyacrylonitrile fibre substrates at boiling temperature (98 -1 00 C) are only slight. The consequence is that the unlevel dyeings obtained on account of the high exhaustion rate of these dyes during the exhaust procedure can only be rectified under conditions which impair the productivity of the dyehouse or the retention of the quality of the textile, for example by prolonging the boiling phase or substantially increasing the dyeing temperature.

To avoid these difficulties, different dyeing processes have been developed which, however, have the drawback that they have to be adapted to the type of polyacrylonitrile fibre, the make-up of the fabric, the apparatus employed, the rate of exhaustion of the dyes employed, and the depth of shade. These processes have for their object to prolong the exhaustion procedure, either by slow heating or by adding substantial amounts of cationic or anionic retarders. In actual practice, a combination of there two possibilities is usually favoured.

Further, processes for dyeing polyacrylonitrile fibres are known in which dyeing is carried out in the presence of quaternary ammonium salts as retarders, levelling agents or migration assistants.

German Auslegeschrift 1123 286 for example discloses a process for dyeing polyacrylonitrile textiles with basic dyes or disperse dyes, wherein dyeing is carried out in the presence of quaternary ammonium compounds of the formula

in which R1 to R5 represent unsubstituted or substituted aliphatic, aromatic, araliphatic or hydroaromatic hydrocarbon radicals, one or two of which contain at least 8 carbon atoms, whilst ze'is an anion.

Non-migrating dyes are employed in this known process and the dodecyloxymethyl-dimethyl-benzylammonium chloride used in it acts as retarder for the non-migrating dyes. Likewise, US patent specification 3716329 discloses alkoxymethyltripropyl- or -tributyl-ammonium compounds and octadecyloxymethylpyridinium chloride, which are used for dyeing polyacrylonitrile fibres with non-migrating dyes. However, both dodecyloxymethyl-dimethyl-benzyl-ammonium chloride and alkoxymethyltripropyl- or -tributylammonium compounds and octadecyloxymethyl-pyridinium chloride do not yield satisfactory resuits when dyeing polyacrylonitrile fibres with migrating dyes, because they do not migrate and accordingly are not adapted to the dyes.

There have now been found further dyeing assistants with which, on account of their suitable affinity, substantially more level dyeings are obtained than with the ammonium compounds discussed above when dyeing polyacrylonitrile fibres with migrating cationic dyes. The novel assistants are of lower affinity than the retarders mentioned above. They must promote the levelness characteristics of the migrating cationic dyes, so that dyeings of improved levelness are obtained. In addition, a heating phase of only 5 to 20 minutes is required, so that a distinct shortening of the entire dyeing process is achieved.

Accordingly, the present invention provides a process for dyeing polyacrylonitrile fibre material which comprises dyeing said material with an aqueous dyebath which contains at least one migrating cationic dye and at least one quaternary compound of the formula

wherein R is an aliphatic hydrocarbon radical of 6 to 22, preferably 10 to 14, carbon atoms, or a cycloaliphatic radical of 5 to 12 carbon atoms, each of X1 and X2 iS methyl or ethyl or together with the nitrogen atom to which they are attached are a 5- or 6-membered saturated heterocyclic radical, X3 is lower alkyl, hydroxy-lower alkyl or cyano-lower alkyl, and An(3 is the anion of an organic or inorganic acid. Preferably, the dyebath contains at least two or more preferably at least three migrating cationic dyes.

In the definition of Xs, lower alkyl ordinarily denotes those groups or group constituents which contain 1 to 5, in particular 1 to 3, carbon atoms, e.g. methyl, ethyl, n-propyl, iso-propyl, n-butyl, sec-butyl or n-amyl.

As defined herein, the cation dyes which can be used in the process of the invention have migration properties. Suitable migrating cationic dyes are in particular those having a more or less delocalised positive charge, a cationic weight which is lower than 310, a parachor which is smaller than 750, and a log P which is smaller than 3.6. The parachor is calculated in accordance with the article by O.R. Quayle in Chem. Rev. 53, 439 (1953), and log P denotes the relative lipophilic properties, the calculation of which has been described by C. Hansch et al. in J. Med. Chem. 16, 1207 (1973). The influence of the charge ofthe dye cations was not taken into account in this calculation, thus resulting in log P values which are higher by 6 log units.

Preferred migrating cationic dyes are those having a cationic weight lower than 275, a parachor smaller than 680, and a log P smaller than 2.8.

These dyes can belong to different classes of dye. In particular, they are salts, e.g. chlorides, sulfates or metal halides, e.g. zinc chloride double salts, of azo dyes, such as monoazo dyes or hydrazone dyes, anthraquinone, diphenylmethane, triphenylmethane, methine or azomethine dyes, coumarin, ketone-imine, cyanine, xanthene, azine, oxazine or thiazine dyes.

Particular good results are obtained when using the yellow dye of the formula

having a cation weight of 226, a parachor of 558 and a log P of 2.49; the red dye of the formula

having a cation weight of 244, a parachor of 610 and a log P of 2.68; and the blue dye of the formula

having a cation weight of 248, a parachor of 693 and a log P of 6.32.

These dye salts are suitable in particular for obtaining level combination shade dyeings including trichromatic dyeing, i.e. the triple combination of the basic shades, yellow (or orange), red and blue.

The amounts in which the migrating dyes are added to the dyebaths can vary within wide limits, depending on the desired depth of shade. In general, amounts of 0.01 to 5, preferably 0.1 to 2, percent by I weight, based on the weight of the goods to be dyed, have been found advantageous.

In formula (1), R preferably represents an alkyl radical of 6 to 22, in particular 10 to 14, carbon atoms.

Examples of such alkyl radicals are: hexyl, octyl, decyl, dodecyl, myristyl, hexadecyl, heptadecyl, octadecyl, arachidyl or behenyl. Preferably, R is octyl, decyl, dodecyl, tetradecyl (myristyl) or a mixture of these alkyl radicals.

As a cycloaliphatic radical, R is for example cyclopentyl or preferably cyclohexyl. The X radicals can be different from each other or they are preferably identical. As a lower alkyl group, X3 is in particular methyl or ethyl. X3 as hydroxy-lower alkyl or cyano-lower alkyl is in particular 2-hydroxyethyl, 3-hydroxypropyl or 2-cyano-ethyl. X3 is preferably methyl or ethyl.

A heterocyclic radical represented by X1 and X2 together with the nitrogen atom to which they are attached is e.g. pyrrolidino, piperidino, pipecolino, thiomorpholino or preferably morpholino. Each of X1 and X2 is preferably ethyl or methyl or together with the nitrogen atom they are morpholino. Suitable anions An0 are both anions of inorganic acids, e.g. the chloride, bromide, fluoride, sulfate or phosphate ion, and of organic acids, e.g. of aromatic or aliphatic sulfonic acids, such as the benzenesulfonate, p-toluene-sulfonate, chlorobenzenesulfonate, methanesulfonate or ethanesulfonate ion, and also the anions of acid alkyl esters of inorganic acids, such as the methosulfate or ethosulfate ion. An 8 its in particular the chloride, bromide or methosulfate ion.

The quaternary ammonium compounds of the formula (1 ) are obtained by reacting alcohols of the formula R-OH (2) with formaldehyde or a formaldehyde donor and a hydrogen halide, preferably hydrogen chloride, and subsequently further reacting the resulting halomethyl ether with a tertiary amine of the formula

Suitable formaldehyde donors are in particular paraformaldehyde, trioxane or hexamethylenetetramine.

rhe manufacture of such ammonium compounds is described e.g. in British patent specification 394 196.

The quaternary compounds of formula (1) are used in amounts of 0.1 to 5, preferably 0.5 to 2, percent by weight, based on the weight of the polyacrylonitrile fibre material.

Mixtures which contain two or more of the quaternary compounds of the formula (1) can also be used in the process of the present invention.

Particularly suitable quaternary ammonium compounds of the formula (1) are those having a cation weight greater than 250, a parachor greater than 720, and a log P smaller than 3.05.

Important representatives of quaternary ammonium compounds of the formula (1) are: n-octyloxymethyl-trimethylammonium chloride, n-octyloxymethyl-trimethylammoniummethylsulfate, n-octyloxymethyl-triethylammonium chloride, n-decyloxymethyl-trimethylammonium chloride, n-decyloxymethyl-triethylammonium chloride, n-dodecyloxymethyl-trimethylammonium chloride, n-dodecyloxymethyl-triethylammonium chloride, n-tetradecyloxymethyI-trimethylammonium chloride, n-tetradecyloxymethyl-triethylammonium chloride, n-tetradecyloxymethyl-trimethylammoniummethylsulfate, n-tetradecyloxymethyl-triethylam mon i u methylsulfate, n-tetradecyloxymethyl-trimethylammon iu m-p-toluene sulfonate, n-tetradecyloxymethyl-N-methyl-morpholinium chloride, n-tetradecyloxymethyl-N-ethyl-morpholinium chloride.

Mixtures of these ammonium salts can also advantageously be used. Particularly preferred quaternary compounds of the formula (1) are n-dodecyloxymethyl-trimethylammonium chloride, n-dodecyloxymethyltriethylammonium chloride and n-dodecyloxymethyl-N-methyl-morpholinium chloride.

The dyebath can also contain electrolytes, in particular inorganic salts, such as alkali metal salts, preferably sodium salts, such as sodium chloride or sodium sulfate, potassium salts, such as potassium chloride or potassium sulfate, ammonium salts, such as ammonium chloride or ammonium sulfate. These electrolytes are employed in amounts of 1 to 10, preferably 5 to 10, percent by weight, based on the weight of the material to be dyed. Preferred dyebaths, however, contain no electrolytes.

In addition, the dyebaths can contain acids, e.g. mineral acids, such as sulfuric acid or phosphoric acid, or organic acids, preferably lower aliphatic carboxylic acids, such as formic, acetic or oxalic acid. These acids are employed in particular to adjust the pH value of the dyebaths of the invention, which is ordinarily 2.5 to C, preferably 3 to 5. The dyebath can also contain an alkali metal acetate, e.g. sodium acetate, ammonium acetate, ammonium citrate or ammonium phosphate, to stabilise a specific pH value.

Dyeing is advantageously carried out from an aqueous liquor by the exhaust method. The liquid ratio depends on the apparatus employed, the substrate, the make-up of the goods, and on the package density. It can be chosen, however, within a wide range, for example from 1 to 1:100, but is usually between 1:5 and 1:40. The dyeing temperature is at least 70"C and is ordinarily not higher than 106"C. Preferably it is in the range from 80 to 1030C.

The process can be carried out such that the goods to be dyed are either briefly treated first with the quaternary compounds of the formula (1) and subsequently dyed or, preferably, treated simultaneously with the quaternary compound and the migrating dye. Preferably, the goods are put at 70 to 900C into a bath which has been adjusted to a pH of 3 to 5, then the quaternary compound of the formula (1) and the dye are added and the temperature is raised in the course of 5 to 15 minutes to 98"C and dyeing is carried out for 15 to 45 minutes at this temperature, or the goods are put into the dyebath at boiling temperature and dyed for 30 to 60 minutes at this temperature.It is also possible, however, to heat the dyebath in the course of 15 to 30 minutes to a temperature of 105"C (high temperature dyeing) and then to maintain this temperature for 15 to 45 minutes. When dyeing is complete, the dyebath is slowly cooled and the goods are rinsed with water and dried.

The acrylic fibres which can be dyed by the process of the present invention comprise the commercially available types of polymers and copolymers of acrylonitrile. The content of acrylonitrile in acrylonitrile copolymers is advantageously at least 80%, based on the weight of the copolymer. Polyacrylonitrile fibres usually consist of about 85% by weight of acrylonitrile and about 15% by weight of copolymer.

The polyacrylonitrile fibres can have different dyeing properties, i.e. the process of the present invention can be used for all types of polyacrylonitrile fibres, namely for rapid-dyeing, standard-dyeing and slow-dyeing polyacrylonitrile fibres.

There is a very close connection between the different dyeing rates of the different types of polyacrylonitrile fibres and the respective glass transition temperature. The lower the glass transition temperature, the higher the rate of dyeing of the fibre and vice versa. The migration follows the same rules.

In addition, it increases sharply with rising temperature. At a given dyeing temperature, the dyes migrate onto rapid-dyeing fibres about four times as quickly as onto slow-dyeing fibres.

The material to be dyed can be made up in different forms, e.g. loose material, slubbing, cable, yarn, cheeses, warp beam, muffs, wound packages, knitted fabrics, wovens, carpets. The fibre materials can also be employed as blends with each other or with other fibres, e.g. blends of polyacrylonitrile/polyester or polyacrylonitrile/wool. As already mentioned, level single-shade and, in particular combination shade dyeings are obtained by the process of the invention at conventional dyeing temperatures and using migrating dyes. Irrespective of the type of polyacrylonitrile fibre to be dyed, shorter heating times are possible than when using non-migrating cationic dyes. In addition, the process of the invention makes it possible to rectify in simple manner unlevel dyeings which may be obtained, and it also permits shading at boiling temperature.

The dyeings obtained are distinguished by good fastness properties, in particularwetfastness properties, such as fastness to washing, water, perspiration and decatising. The other fastness properties of the dyeings, e.g. lightfastness and fastness to rubbing, are not affected by the use of the quaternary compounds according to the invention.

In the following Examples the percentages are by weight, unless otherwise stated. In connection with the dyes, the amounts relate to commercially obtainable, i.e. diluted, product, and in connection with the quaternary compounds, the amounts relate to pure substance.

With respect to the dyes and the quaternary compounds, K denotes cation weight, Pa denotes parachor and log P denotes relative lipophilic properties.

Example I: In a dyeing machine, 25 g of a pre-shrunk woven fabric made from rapid-dyeing polyacrylonitrile fibres are treated for 5 minutes at 80"C in 350 ml of an aqueous liquor which is adjusted to a pH value of 4 with 80% acetic acid. To the dyebath are then added 0.125 g of a quaternary compound of the formula

having a cation weight of 258, a parachor of 728 and a log P of 1.35,0.025 g of a dye of the formula (102) and 0.025 g of a dye of the formula (103). The temperature of the dyebath is then raised in the course of 10 minutes to 98"C and the fabric is dyed for 30 minutes at this temperature. The dyebath is subsequently slowly cooled to 60"C and the fabric is rinsed and dried.A level violet dyeing of good penetration, good wetfastness properties, and good fastness to light and rubbing, is obtained.

Strong and level dyeings having good fastness properties are also obtained by using, instead of the quaternary compound of the formula (11), the same amount of the compound of the formula (12)

having a cation weight of 300, a parachor of 798 and a log P of 1.68, or of the formula (13)

having a cation weight of 300, a parachor of 849 and a log P of 2.94.

Example 2: In a dyeing machine, 25 g of a woven fabric made from standard-dyeing polyacrylonitrile fibres are pre-shrunkfor 10 minutes at boiling temperature in 200 ml of a liquorwhich is adjusted to a pH value of 4 with 80% acetic acid. To the liquor are then added 0.05 g of a quaternary compound of the formula (12), 0.025 g of a dye ofthe formula (103) and 0.025 of a dye of the formula (101). The fabric is then dyed for 60 minutes at boiling temperature. The dyebath is subsequently slowly cooled, whereupon the goods are rinsed and dried. A level, brilliant green dyeing of good penetration and excellent fastness to light and rubbing is obtained. A level and brilliant green dyeing is likewise obtained by using, instead of the morpholinium compound of the formula (12), the same amount of an ammonium compound of the formula (11) or (13).

Claims

1. A process for dyeing polyacrylonitrile fibre material, which comprises dyeing said material with an aqueous dyebath which contains at least one migrating cationic dye and at least one quaternary compound of the formula

wherein R is an aliphatic hydrocarbon radical containing 6 to 22 carbon atoms or a cycloaliphatic radical of 5 to 12 carbon atoms, each of X1 and X2 is methyl or ethyl or together with the nitrogen atom to which they are attached are a 5-to 6-membered saturated heterocyclic radical, X3 iS lower alkyl, hydroxy-lower alkyl or cyano-lower alkyl, and An 8 is an anion of an organic or inorganic acid.

2. A process according to claim 1,wherein the dyebath contains at least two or three migrating cationic dyes.

3. A process according to either of claims 1 or 2, wherein the dyebath contains a migrating cationic dye having a cation weight lower than 310, a parachor smaller than 750, and a log P smaller than 3.6.

4. A process according to claim 3, wherein the migrating cationic dye has a cation weight lower than 275, a parachor smaller than 680, and a log P smaller than 2.8.

5. A process according to any one of claims 1 to 4, wherein the dyebath contains a quaternary compound of the formula (1), wherein R represents alkyl of 6 to 22 carbon atoms.

6. A process according to any one of claims 1 to 5, wherein the dyebath contains a quaternary compound of the formula (1), wherein each of X1 and X2 is methyl or ethyl, or together with the nitrogen atom to which they are attached, are a morpholino radical.

7. A process according to any one of claims 1 to 6, wherein the dyebath contains a quaternary compound of the formula (1), wherein X3 is methyl or ethyl.

8. A process according to any one of claims 1 to 7, wherein the quaternary compound of the formula (1) has a cation weight greater than 250, a parachor greater than 720, and a log P smaller than 3.05.

9. A process according to any one of claims 1 to 8, wherein the quaternary compound of the formula (1) is n-dodecyloxymethyl-trimethylammonium chloride, n-dodecyloxymethyl-triethylammonium chloride or n-dodecyloxymethyl-N-methyl-morpholinium chloride.

10. A process according to any one of claims 1 to 9, wherein the dyebath contains the quaternary compound of the formula (1) in an amount of 0.1 to 5, percent by weight, based on the weight of the polyacrylonitrile fibre material.

11. A process according to any one of claims 1 to 10, wherein the dyebath additionally contains an inorganic electrolyte.

12. A process according to any one of claims 1 to 11, wherein dyeing is carried out at a temperature of 70 to 106"C.

13. A process according to any one of claims 1 to 12, which comprises putting the material to be dyed into the dyebath at a temperature ranging from 80 to 90"C, heating the dyebath in the course of 5 to 15 minutes to 98"C, and dyeing at this temperature for 15 to 45 minutes.

14. A process according to any one of claims 1 to 13, which comprises the use of rapid-dyeing, standard-dyeing or slow-dyeing polyacrylonitrile fibres.

15. An aqueous dyebath for dyeing polyacrylonitrile fibres which comprises at least one migrating dye and at least one quaternary compound of the formula

wherein R is an aliphatic hydrocarbon radical containing 6 to 22 carbon atoms or a cycloaliphatic radical of 5 to 12 carbon atoms, each of X, and X2 is methyl or ethyl or together with the nitrogen atom to which they are attached are a 5-to 6-membered saturated heterocyclic radical, X3 is lower alkyl, hydroxy-lower alkyl or cyano-lower alkyl, and An O is an anion of an organic or inorganic acid.

16. A process according to Claim 1, substantially as hereinbefore described with reference to either of the foregoing Examples.

17. An aqueous dyebath according to Claim 15, substantially as hereinbefore described with reference to either of the foregoing Examples.