Use of Polyoxyalkylated Alkyl Phenols as Dyeing Assistants for Disperse Dyes

The present invention relates to dyeing assistants for dyeing or printing with disperse dyes or for lightening or stripping disperse dyeings or printings.

The invention provides a process for shifting the equilibrium of disperse dyestuffs between an aqueous liquor and a textile substrate comprising adding to the aqueous liquor a compound of formula I ##STR2## wherein R.sub.1 and R.sub.2, independently, are hydrogen or C.sub.4-12 alkyl, provided that R.sub.1 and R.sub.2 are not both hydrogen;

R is a mixed chain containing from 7 to 31 ethyleneoxy and 3 to 27 propyleneoxy units,

with the proviso that R contains at most a total of 34 units.

Any alkyl as R.sub.1 or R.sub.2 may be branched or straight chain. Preferred alkyl groups are C.sub.4-10 alkyl, particularly tert.butyl, octyl, iso-octyl or nonyl, more particularly iso-octyl or nonyl. R.sub.2 is preferably hydrogen. R.sub.1 is preferably alkyl.

R is preferably an ordered chain of a block of ethyleneoxy units followed by a block of propyleneoxy units or an ordered chain of a block of propyleneoxy units followed by a block of ethyleneoxy units or an ordered chain of 2 blocks of propyleneoxy units separated by one block of ethyleneoxy units, the indicated order of each chain beginning from the phenoxy moiety.

Preferably R contains from 7 to 18, preferably 7 to 12 ethyleneoxy units. The total number of propyleneoxy units present in R is preferably from 3 to 16, more preferably from 4 to 10.

Preferred compounds of formula I are those wherein R.sub.1 is C.sub.6-10 alkyl, preferably iso-octyl or nonyl, especially nonyl, R.sub.2 is hydrogen and R is an ordered chain of 7 to 18, preferably 7 to 12, especially 8, ethyleneoxy units and 3 to 16, preferably 4 to 10, especially 6, propyleneoxy units.

Compounds of formula I may be produced by known methods, for example by condensing the corresponding mono- or dialkyl phenol or a mixture thereof, with ethyleneoxide and propyleneoxide in the desired sequence. The condensation is conveniently carried out in the presence of a catalyst such as an alkali metal or an alkali metal hydroxide at temperatures of from 140.degree. to 180.degree. C., preferably 150.degree. to 160.degree. C. Preferably the condensation is effected in the absence of a solvent.

The compounds of formula I are useful as agents for shifting the dyestuff equilibrium between the liquor and the textile substrate. When used in suitable, preferably small, quantities the compounds of formula I are capable of shifting the equilibrium in favour of the liquor to the extent that the adsorption of the disperse dyes onto the fibres is retarded. In this case, the dyeing assistants of formula I are used during the dyeing, padding or printing process and have a notable levelling effect. They are added to the dyebath, the padding liquor or the printing paste in amounts generally ranging from 0.5 to 5 g/l, preferably from 1 to 3 g/l. The dyeings and printings thus achieved have a good levelness and their fastness properties are not impaired.

The compounds of formula I are preferably used for exhaust dyeing, more preferably under high temperature conditions (100.degree.-140.degree. C.). The dyebath may contain further assistants, e.g. one or more dispersing agents, preferably anionic dispersing agents.

The compounds of formula I, especially when used in larger quantities are capable of reversing the dyeing process so that the dyestuff is removed from the dyed fibre. In this case, the compounds of formula I have a lightening or a stripping effect on the disperse dyeings or printings. The textile substrate dyed or printed with disperse dyes is treated with a liquor containing a compound of formula I according to the known lightening or stripping methods. Depending on the desired effect, the compounds of formula I may be used in an amount ranging, for example, from 2 to 100 g/l, preferably from 6 to 100 g/l.

According to a preferred embodiment of the invention, the compounds of formula I are used as levelling agents for dyeing with disperse dyes and are added to the dyebath, padding liquor and printing paste. Preferably the compounds of formula I are used in admixture with one or more anionic dispersing agents, e.g. an at least partially carboxymethylated condensation product of a C.sub.4-15 alkyl- or di(C.sub.4-15 alkyl)-phenol with 5 to 50 mols alkylene oxide, preferably ethylene oxide, sulphonated diphenyl or ditolyl ether, sulphonated alkylC.sub.4-15 benzene or sulphonated castor oil. Mixtures of one or more compounds of formula I with one or more anionic dispersing agents form part of the invention. In such mixtures, the weight ratio of the anionic dispersing agent to the compound of formula I is 0.1-1:1, preferably 0.2-0.5:1.

Suitable textile substrates which may be dyed or printed according to the invention are those consisting of or comprising synthetic or semi-synthetic hydrophobic, high molecular weight organic textile materials, e.g. polyester, cellulose triacetate and cellulose 21/2 acetate, especially linear, aromatic polyester.

The following Examples further serve to illustrate the invention. In the Examples all parts and percentages are by weight and all temperatures in degrees Centigrade.

150 parts (1 mol) 4-tert.-butylphenol and 2 parts sodium hydroxide are heated to 160.degree. C. under a nitrogen atmosphere. 308 parts (7 mols) ethylene oxide are then introduced at the same temperature at such a rate that the reaction is complete after one hour. Subsequently, 232 parts (4 mols) propyleneoxide are added dropwise at 150.degree. over 2 hours to the reaction mixture.

After cooling and the addition of 3 parts glacial acetic acid, there are obtained about 693 parts of a brown liquid which has a cloud point at 32.degree. when diluted to 1% with water.

By following the same procedure and reacting 1 mol phenol with first ethyleneoxide and then propyleneoxide there are obtained the compounds of formula I indicated in the Table below.

220 Parts (1 mol) nonylphenol are reacted at 160.degree. in the presence of 2 parts sodium hydroxide as catalyst first with 174 parts (3 mols) propyleneoxide, then with 440 parts (10 mols) ethyleneoxide and finally with 290 parts (5 mols) propyleneoxide.

1126 Parts of a compound having a cloud point at 44.degree. (diluted to 1% with water) is thus obtained.

A polyester fabric is dyed in a HT-laboratory dyeing machine with a dyebath containing 0.5 g/l of the dye C.I. Disperse Blue 73 (Constitution No. 63265) and 1 g/l of the compound of Example 7 and adjusted with acetic acid to pH 5. The goods to liquor ratio is 1:20. The temperature of the dyebath is raised to 130.degree. at a heating rate of 3.degree./min.

A blue dyeing with an excellent levelness is thus obtained.

Polyester cross-wound bobbins are dyed under high temperature conditions with 2% of the dye C.I. Disperse Red 72 (Constitution No. 111 114), at a goods to liquor ratio of 1:15. The dyebath which circulates at a rate of 30 l/kg/min contains 1 g/l of the compound of Example 8 and 0.5 g/l of a commercially available dispersing agent or a mixture of dispersing agents (e.g. based on an ethoxylated, carboxymethylated mono- or di[C.sub.4-15 alkyl]phenol or a sulphonated diphenyl ether) and is adjusted to pH 5 with ammonium sulphate and formic acid. The dyebath is heated to 130.degree. at a rate of 3.degree./min.

The resulting red dyeing has an excellent levelness.

Polyester knitted goods which have previously been unequally dyed with 2% of C.I. Disperse Red 73 (Constitution No. 11116) are treated for 30 minutes at 130.degree. with a bath containing 2 g/l of the compound of Example 8 and adjusted to pH 5 with acetic acid. The goods to liquor ratio of 1:20.

By this treatment, the dyeing becomes lighter and also level.

A polyester fabric which has previously been dyed with

(a) 0.625% of the commercially available C.I. Disperse Red 73 or

(b) 0.65% of the commercially available C.I. Disperse Blue 183

is treated for 1 hour at 130.degree. with the compound of Example 7. The goods to liquor ratio is 1:40 and the treatment bath is adjusted to pH 5. The following stripping or lightening effects are obtained for the various amounts of compound of Example 7.

These results have been assessed in % of the dye applied on the substrate measured through the remission.

A polyester fabric dyed with 2 g/l of the commercially available C.I. Disperse Blue 183 is padded at room temperature with a bath containing 30, 50 or 100 g/l of the compound of Example 7, to a pick-up of 100% based on the dry weight. The substrate is then dried at 130.degree. for 60 minutes and subsequently treated for 2 minutes at 220.degree. for fixation. The resulting "stripping" effect is evaluated in notes in comparison with an undyed substrate according to the Grey Scale: for 30 g/l of the compound of Example 7 the note is 1.8, for 50 g/l the note is 2.4 and for 100 g/l, the note is 3.3.