Many attempts have been made to develop efficient processes for printing or dyeing polyester-cotton blends.

Two fundamentally different approaches were taken: Processes using one class of dye only and processes using mixtures of two classes of dyes.

Usually reactive dyes or vat dyes are combined with disperse dyes.

However, the use of such dye mixtures is associated with several drawbacks and it is hardly possible to obtain the same colour and depth on the two fibres by this method.

DE 1 811 796 describes a process for dyeing cellulose fibres or blends of cellulose fibres and synthetic fibres with a single disperse dye which process comprises contacting said cellulosic material with water in sufficient amount to swell the cellulose, a solution or dispersion of the dye and a high-boiling water-soluble solvent in an amount sufficient to maintain swelling of the cellulose if water is removed.

In J. Soc. Dyers Colour., 96,347-354 (1980) specific disperse dyes (Cellestrene, supplied by BASF) in combination with Glyzin@ CD, a polyalkylene oxide derivative, are recommended for application in the printing process described in DE 1 811 796. The prints on polyester- cotton blends obtained by this process are described as exhibiting brilliant colours with the same depth of colour on both fibres.

However, the Cellestren/Glyezin system does not meet the top requirements with respect to light fastness and wash fastness.

It has now been found that the application of some specific disperse dyes in the process disclosed in DE 1 811 796 yields prints and dyeings on polyester-cotton blends having extraordinarily good light fastness and wash fastness.

The present invention relates to a process for printing or dyeing cellulose fibres or cellulose/polyester mixed fibres characterised in that the fibres are treated in any sequence with water, a water-soluble organic solvent having a boiling point >150 °C and a disperse dye selected from the compounds of formulae (1) to (10)

wherein Ri and R2 are each independently of the other C1-C8-alkyl, -(CH2)n-O-(CH2)mR5. wherein R5 denotes hydrogen or C1-C8-alkyl, n is a number from 2 to 6 and m is a number from 0 to 6, C6-C24aryl, which is unsubstituted or substituted with one or more hydroxy groups, C1-C8alkyl groups, C1-C4alkoxy groups or halogen atoms or C6-C30aralkyl, which is unsubstituted or substituted with one or more hydroxy groups, C1-C4alkyl groups, C1- C4alkoxy groups or halogen atoms, R3 and R4 are each independently of the other chlorine, bromine, cyano, methyl or trifluoromethyl, X is a radical of formula (1a), (1b), (1c) or (1d) wherein R6 and R7 independently of the other represent hydrogen, chlorine, bromine or cyano, R8 denotes C1-C8-alkyl or -(CH2)n-O-(CH2)mR5, wherein R5 denotes hydrogen or C1-C8-alkyl, n is a number from 2 to 6 and m is a number from 0 to 6, R9 is hydrogen, fluorine, chlorine, bromine, cyano, methyl, trifluoromethyl or-SO2CH3 and Rio represents hydrogen, hydroxy or amino; wherein Rll denotes a radical of formula (2a), (2b), (2c) or (2d)

wherein R17 is hydrogen, chlorine, bromine, methyl or methoxy, Rig is hydrogen, phenylamino, benzamid or C1-C12acylamido, one of the radicals R12, R13 and R14 denotes a radical of formula (2a), (2b), (2c) or (2d) as defined above and the others are hydrogen, and R15 and Rie are each independently of the other hydrogen, bromine or chlorine;

wherein Rig denotes C1-C8alkyl or-(CH2) n-O-(CH2) m-OR20, and R20 is hydrogen, methyl or ethyl, n denotes a number from 2 to 6 and m denotes a number from 0 to 6; wherein R21 is Ci-Csalkyl, C5-C24aryl, which is unsubstituted or substituted with one or more hydroxy groups, C1-C8alkyl groups, C1-C4alkoxy groups or halogen atoms or C6-C30aralkyl, which is unsubstituted or substituted with one or more hydroxy groups, C1-C4alkyl groups, C1-C4alkoxy groups or halogen atoms; wherein R22 and R23 are each independently of the other hydrogen, bromine or chlorine ;

wherein R24 denotes chlorine, bromine, cyano or-CONH2, R25 is C,-C2oalkyl or-(CH2) n-O-(CH2) mR5 wherein Rs denotes hydrogen or C1-C8-alkyl, n is a number from 2 to 6 and m is a number from 0 to 6, D is a radical of formula (1c) as defined above or a radical of formula (6a) wherein Rg, Rio and R25 are as defined above;

wherein R26 denotes C1-C12alkoxy ;

wherein Me denotes Ni, Zn, Pd or preferably Cu, R27 is hydrogen, C1-C12alkoxy or -SO2-NH-R25 and R25 is as defined above;

wherein R28 and R29 are each independently of the other a radical of formula (2b) or (2d) as defined above; wherein R8 and R17 are as defined above.

The compounds of formulae (1) to (10) are known and either commercially available or can be prepared according to known processes.

Preferred compounds of formula (1) are those wherein R3 is cyano and R4 is methyl.

In a preferred embodiment of the invention a compound of formula (1) is used as disperse dye, wherein R3 is cyano, R4 is methyl and X is a radical of formula (1a), (1b) or (1d).

Particularly preferred disperse dyes are the compounds of formula (1), wherein R3 is cyano, R4 is methyl and X is a radical of formula (1d).

Further preferred disperse dyes are the following compounds:

Particularly preferred disperse dyes are the compounds of formulae (101), (102), (108), (109), (110), (115), (116), (118), (119), (120), (124), (133), (141), (143), (144), (152) and (154).

The most preferred disperse dyes are the compounds of formula (101) and (102) All the embodiments described in DE 1 811 796, hereby incorporated by reference, can basically be performed by using the disperse dyes of formula (1) to (10).

The organic solvent used in the process according to the invention should be water-soluble and have a high dissolving capacity for the disperse dyes of formulae (1) to (10) at the fixation temperature.

Water-soluble in this context means solubility in water of at least 2.5 % by weight at 25 °C.

Suitable solvents of this type are glycols and their derivatives, in particular the ethers and esters.

The preferred organic solvents that can be applied in the process according to the invention are polyethylene glycol, polypropylene glycol or an ether or ester derivative of polyethylene glycol or polypropylene glycol.

Polyethylene glycol having a molecular weight of 100 to 600 is particularly preferred.

In dyeing cellulosic materials by the process of the invention, water, dye and solvent can be applied to the substrate in any sequence. The preferred method for dyeing fabrics composed of cellulosic fibres or mixtures of cellulosic and synthetic fibres is to impregnate the fabric with a mixture of one or more dyes, water and solvent in a conventional dye pad bath followed by squeezing to remove excess dye liquor, or to print with a solvent-containing printing paste, and subsequently heating to evaporate sufficient water to effect dissolution of the dye, at which time the fabric is dyed. Alternatively, water is evaporated, but in an insufficient amount to effect dissolution of the dye, after which pressure and heat are applied to effect dissolution without further evaporation of water. Dye pastes can be prepared by conventional techniques such as by milling the dye in the presence of a dispersing agent or surFactant. A dyebath can be prepared by diluting the dye paste with water or with aqueous solvent. Addition of a solvent to the dye paste before addition of water may cause dye separation and usually is avoided. It will be understood by those skilled in the art that conventional additives other than a dye solvent and a dispersing agent can be present in dye baths and printing pastes.

Further components which may be present in the printing pastes or dye baths are e. g. natural or synthetic thickeners, pigments, acids, bases and/or salts to adjust the pH to the desired value, anionic, nonionic or cationic surfactants, antifoaming and antifrosting agents, dispersing agents, fixing agents, polyhydroxy compounds, reaction products of hydroxyl compounds and isocyanates, polyesters prepared by reaction of terephthalic acid and one or more polyethylene glycols. These components are commonly used or recommended for textile printing or finishing.

Although it is possible to treat the fibres in any sequence with water, solvent and dye, the three components are preferably contemporaneously applied to the fibre.

The relative amounts of water, solvent and dye that can be applied in the printing pastes and dye baths are known to the skilled artisan.

The printing paste which can be applied in the process according to the invention preferably contains 50 to 95 %, more preferably 60 to 90 % and in particular 70 to 85 by weight of water, based on the total weight of the printing paste.

The amount of organic solvent is preferably 1 to 20 %, more preferably 2 to 15 % and in particular 5 to 10 by weight of, based on the total weight of the printing paste.

The amount of dye dispersion is preferably 1 to 15 %, more preferably 2 to 10 % and in particular 3 to 8 by weight of, based on the total weight of the printing paste.

The temperature at which dyeing or printing is effected by the instant process depends on the solubility of the dye in the dye solvent or aqueous dye solvent.

Preferably, the fibres are heated in a liquor at 125 °C to 225 °C, said liquor containing as liquid ingredients 10 to 95 % by weight of water and 5 to 90 % by weight of organic solvent.

The cellulosic materials which can be dyed by the process of this invention include all forms of cellulose which increase in size and flexibility upon exposure to water. Suitable materials include natural fibres and purified wood pulps as well as reconstituted cellulose in fiber and film form.

The invention is particularly useful for dyeing cotton/polyester mixed fibres.

The following non-limitative Examples illustrate the invention in more detail.

Application Examples : 1. Dispersion Each dye is dispersed according to the following formulation : 29, 2% dye 7. 3% 1, 2-propylenglykol (solvent) # 3. 7% Lutensol AT25 (dispersant) 0. 8% Geropon T77 (wetting agent) 0. 1% Surfinol DF58 (antifoam agent) 0. 4% Proxel GXL (antimicrobial) # 58. 5% deionised water Zirconium beads (diameter 0.6 to 1 mm) are then added to the above-obtained dispersion in a glass bottle tightly closed. The bottle is then placed in a Scandex apparatus and thereby agitated for 4 hours.

The thus obtained fine dispersion is then filtered on a conventional Bücher funnel to provide the final dye dispersion.

2. Printing paste A typical run consists in the preparation of a mother paste, to which a quantity of the dye dispersion and water will be subsequently added.

- Mother paste: * 84. 2% deionised water 0. 8% NH40H (28%) # 0. 4% Alcoprint PA-NS # 9. 9% PEG400 # 2. 3% Alcoprint PSC # 2. 4% Alcoprint PTP - Printing paste 33. 3% deionised water 60. 1% mother paste # 6.6% dye dispersion

The amount of added deionised water can vary as a function of the viscosity of the dye dispersion and/or of the printing paste.

3. Printing The printing paste is applied in a classical way on the textile (CO or PES/CO) through a screen. After drying at 90°C, the textile is thermofixed at 220°C for 1 minute.

After a brief cold rinse, a 30 minutes wash at 80°C is performed in a bath containing: 2g/L carbonate 1g/L Calgon <BR> 1 g/L Ultravon JU 4. Tests All thus obtained printed fabrics exhibit a very good light fastness, wash fastness and wet rubbing fastness.