Dyestuffs containing chromophores linked via a piperazine type linking unit are known from literature and are described for example in EP-A-0126265, EP-A- 0693538 and W099/05224.

The inventor of the present invention has surprisingly found that dyestuffs with a very strong and economic scarlet shade'exhibitihg excellent fastness properties can be obtained if piperazine type linking units are used to link two different chromophores each selected from a specific range of chromophores as defined below.

The present invention claims dyestuffs of the formula I wherein each of R1, R2, R3, R4 and R5, independently, is H or an optionally substituted alkylgroup; each of X, andX2, independently, is a labile atom or group; B is H or S03M ; M is H, an alkali metal, an ammonium ion or the equivalent of an alkaline earth metal ;

Ar is a group of the formula 11 or of the formula III wherein Y is S03M or an alkyl group, c is 0,1 or 2, M is defined as given above and # indicates the bond to the azo group in formula I ; D is a group of the formula IV wherein Ar1 is defined as Ar, M is defined as given above and * indicates the bond to the NR'group of formula 1 ; or D is a group of the formula V wherein R6 is an alkyl group, B, is defined as B and M and * are defined as given above; each of x and y, independently, is 0 or 1 and at least one of x and y is 1; each of a and b is 2 to 5 and when each of x and y is 1, a > b; and z is 0, 1,2,3 or 4.

Alkyl groups may be straight-chain or branched and are preferably (C1-C4)-alkyl groups, for example methyl, ethyl, n-propyl, i-propyl or n-butyl. Substituted alkyl groups are preferably substituted by hydroxyl, (C1-C4)-alkoxy, halogen or carboxyl groups.

R'to R6 are preferably H or methyl. R3, R4 and R5 are especially preferably H.

X, and X2 are preferably halogen like fluorine and chlorine and are especially preferably chlorine.

M is preferably H, an alkaline metal, like sodium, potassium and lithium and is especially preferably sodium.

D is preferably a group of the formula IVa

wherein M, Ar, and * are defined as given above. D is especially preferably a group of the formula Va wherein Ar1 is a group of the formula Ha or lib wherein M is defined as given above.

If D is a group of the formula IVa with Ar1 = a group of the formula Ila or Ilb, R is preferably H.

Ar is preferably a group of the formula Illa wherein M is defined as given above.

If Ar is a group of the formula Illa, R2 is preferably H or methyl. If Ar is a group of the formula Illa, R2 and B are especially preferably H.

In preferred dyestuffs of the formula I x = 1 and y = 0 and a = 2 or x = 0 and y = 1 and b = 2.

Especially preferred dyestuffs of the formula I are the dyestuffs of the formula la and of the formula lb

wherein B and M are defined as given above.

The dyestuffs of the present invention can be present as a preparation in solid or liquid (dissolved) form. In solid form they generally contain the electrolyte salts customary in the case of water-soluble and in particular fibre-reactive dyes, such as sodium chloride, potassium chloride and sodium sulfate, and also the auxiliaries customary in commercial dyes, such as buffer substances capable of establishing a pH in aqueous solution between 3 and 7, such as sodium acetate, sodium borate, sodium bicarbonate, sodium citrate, sodium dihydrogen- phosphate and disodium hydrogenphosphate, small amounts of siccatives or, if they are present in liquid, aqueous solution (including the presence of thickeners of the type customary in print pastes), substances which ensure the permanence of these preparations, for example mold preventatives.

In general, the dyestuffs of the present invention are present as dye powders containing 10 to 80% by weight, based on the dye powder or preparation, of a strength-standardizing colorless diluent electrolyte salt, such as those mentioned above. These dye powders may additionally include the aforementioned buffer substances in a total amount of up to 10%, based on the dye powder. If the dye mixtures of the present invention are present in aqueous solution, the total dye content of these aqueous solutions is up to about 50 % by weight, for example between 5 and 50% by weight, and the electrolyte salt content of these aqueous solutions will preferably be below 10% by weight, based on the

aqueous solutions. The aqueous solutions (liquid preparations) may include the aforementioned buffer substances in an amount which is generally up to 10% by weight, for example 0.1 to 10% by weight, preference being given to up to 4% by weight, especially 2 to 4% by weight.

A dyestuff of the formula I may for example be prepared by reacting a piperazine compound of the formula VI

wherin R3, R4, R5, a, b, x, y, and z are defined as given above, with a compound of the formula VII wherein B, M, R2, X2 and Ar are defined as given above and X3 is a labile atom or a group capable of reaction with an amine, preferably chlorine, and with a compound of the formula VIII wherein D, R'and X, defined as given above and X4 has one of the meanings of X3.

It is possible to react a compound of formula VI first with a compound of the formula VII to form a compound of the formula IX

wherein all variables are defined as given above, which is then reacted with a compound of the formula VIII to a dyestuff of the formula 1.

As an alternative is it also possible to react a compound of the formula VI first with a compound of the formula VIII to form the compound of the formula X wherein all variables are defined as given above, which is then reacted with a compound of the formula VII to a dyestuff of the formula I.

In general, one mole of a compound of the formula VI is reacted with 1 mole of a compound of the formula VII and 1 mole of a compound of the formula VIII in a manner known per se to a skilled person.

The compounds of the formulae VI, Vil and VIII are known or can easily be prepared by a skilled person using methods which are known per se.

As an example, a compound of the formula Vll, wherein X2 is chlorine can be obtained by reacting cyanuric chloride with a compound of the formula XI wherein B, M, R2 and Ar are defined as given above.

The compound of the formula XI can be prepared by means of customary diazotization and coupling reactions in a manner familiar to those skilled in the art using a diazotizated amine of the formula XII Ar-NH2 (XII) and a coupling component of the formula X (II

wherein Ar, B, M and R2 are defined as given above and subsequently removing the acetyl group (-COCH3) by saponification.

The dyestuffs of the instant invention are suitable for dyeing and printing hydroxy-and/or carboxamido-containing fibre materials by the application and fixing methods numerously described in the art for fibre-reactive dyes, in scarlet to mid-red shades with good aqueous solubility, color build-up, wash off and robustness to process variables. Moreover, the dyeings obtained surprisingly show very good lightfastness properties.

The present invention therefore also provides for use of the inventive dyestuffs for dyeing and printing hydroxy-and/or carboxamido-containing fibre materials and processes for dyeing and printing such materials using a dyestuff according to the invention. Usually the dyestuff is applied to the substrate in dissolved form and fixed on the fibre by the action of an alkali or by heating or both.

Hydroxy-containing materials are natural or synthetic hydroxy-containing materials, for example cellulose fibre materials, including in the form of paper, or their regenerated products and polyvinyl alcohols. Cellulose fibre materials are preferably cotton but also other natural vegetable fibres, such as linen, hemp, jute and ramie fibres. Regenerated cellulose fibres are for example staple viscose and filament viscose.

Carboxamido-containing materials are for example synthetic and natural polyamides and polyurethanes, in particular in the form of fibres, for example wool and other animal hairs, silk, leather, nylon-6, 6, nylon-6, nylon-11, and nylon-4.

Application of the inventive dyestuffs is by generally known processes for dyeing and printing fiber materials by the known application techniques for fibre- reactive dyes. The dyestuffs according to the invention are highly compatible with similar dyes designed for high temperature (80-100°C) applications and are advantageously useful in exhaust dyeing processes.

Similarly, the conventional printing processes for cellulose fibres, which can either be carried out in single-phase, for example by printing with a print paste containing sodium bicarbonate or some other acid-binding agent and the colorant, and subsequent steaming at appropriate temperatures, or in two phases, for example by printing with a neutral or weakly acid print paste containing the colorant and subsequent fixation either by passing the printed material through a hot electrolyte-containing alkaline bath or by overpadding with an alkaline electrolyte-containing padding liquour and subsequent batching of this treated material or subsequent steaming or subsequent treatment with dry heat, produce strong prints with well defined contours and a clear white ground. Changing fixing conditions has only little effect on the outcome of the prints. Not only in dyeing but also in printing the degrees of fixation obtained with dye mixtures of the invention are very high. The hot air used in dry heat fixing by the customary thermofix processes has a temperature of from 120 to 200°C. In addition to the customary steam at from 101 to 1 03°C, it is also possible to use superheated steam and high pressure steam at up to 160°C.

The inventive dyestuffs can in addition be used to produce inks useful for printing the substrates described above, for example textiles, especially cellulosic textiles, and paper. Such inks can be used in all technologies, for example conventional printing, ink-jet printing or bubble-jet printing (for information on such printing technologies see for example Text. Chem. Color, Volume 19 (8), pages 23 ff and Volume 21, pages 27 ff).

Acid-binding agents responsible for fixing the dyes to cellulose fibres are for example water-soluble basic salts of alkali metals and of alkaline earth metals of inorganic or organic acids, and compounds which release alkali when hot. Of

particular suitability are the alkali metal hydroxides and alkali metal salts of weak to medium inorganic or organic acids, the preferred alkali metal compounds being the sodium and potassium compounds. These acid-binding agents are for example sodium hydroxide, potassium hydroxide, sodium carbonate, sodium bicarbonate, potassium carbonate, sodium formate, sodium dihydrogen- phosphate and disodium hydrogenphosphate.

Treating the dyestuffs according to the invention with the acid-binding agents with or without heating bonds the dyes chemically to the cellulose fibre.

Especially the dyeings on cellulose, after they have been given the usual aftertreatment of rinsing to remove unfixed dye portions, show excellent properties.

The dyeings of polyurethane and polyamide fibres are customarily carried out from an acid medium. The dyebath may contain for example acetic acid and/or ammonium sulfate and/or acetic acid and ammonium acetate or sodium acetate to bring it to the desired pH. To obtain a dyeing of acceptable levelness it is advisable to add customary leveling auxiliaries, for example based on a reaction product of cyanuric chloride with three times the molar amount of an aminobenzenesulfonic acid or aminonaphthalenesulfonic acid or based on a reaction product of for example stearylamine with ethylene oxide. In general the material to be dyed is introduced into the bath at a temperature of about 40°C and agitated therein for some time, the dyebath is then adjusted to the desired weakly acid, preferably weakly acetic acid, pH, and the actual dyeing is carried out at temperature between 60 and 98°C. However, the dyeings can also be carried out at the boil or at temperatures up to 120°C (under superatmospheric pressure).

Example 1 1- (2-aminoethyl) piperazine (IVa) (1.3g, 0.01 mol) was added dropwise to a stirred suspension of the orange dichlorotriazinyl dye (Vlla) (0.01 mol) in water (400 mis) at ambient temperature and pH6. The pH was then adjusted to 10 with sodium hydroxide solution and maintained at this pH for 30 minutes, yielding a slurry of the orange dye (IXa). To this suspension was added the red dichlorotriazinyl dye (Vllla) (13. 56g, 0.01 mol) and the solution was maintained at pH 10 and ambient temperature overnight. The pH was adjusted to 6 with 2N HCI and the dye precipitated by the addition of methylated spirit. The precipitated dye was filtered off and dried to give the expected dye (la) (1 2. 5g).

(#max = 510nm, # = 76000, v., = 102nm). Other analytical data were in full agreement with the expected structure. Following exactly analogous procedures the following dyes (examples 2-17) were synthesised.

Example Dye 1 Dye 2 X max/nm 2 e d 506 3 h d 511 4 e a 508 5 c e 510 6 a f 513 7 c f 514 8 a g 514 9 e b 508 10 b f 513 11 a h 513 12 c h 514 13 b h 513 14 h b 512 15 b e 509 16 i a 506 17 a i 508 18 c j 511