Vat dyes

This invention relates to the field of vat dyes.

EP 0 057 375 A2 discloses olive green vat dyes obtained by reaction of 1 mol of cyanuric chloride with altogether about 2.8 mol of a mixture of 2-amino-3,4-phthaloyl- 7-bromoacridone and 1-aminoanthraquinone in a molar ratio of 1 :>1.5 between 2-amino-3,4-phthaloyl-7-bromoacridone and 1-aminoanthraquinone (see in particular Examples 1 and 9). These dyes are notable for good properties, but their olive green hue generally does not correspond to the demands of the marketplace, which wants bluish olive to bluish green hues.

For this reason, the dyes described above are frequently blended with blue-dying dyes, or completely different dyes are used. When these dyes are selected, good infrared emission is another important performance characteristic.

Regrettably, however, the likely blending or alternative dyes are very expensive, so that this approach quickly comes up against the limits of economic feasibility.

It is an object of the present invention to make products available to the market which meet the hue and infrared emission requirements and are more economical.

We have found that this object is achieved, surprisingly, when the proportion of 2-amino-3,4-phthaloyl-7-bromoacridone in the above-described products or procedures is enhanced.

The present invention accordingly provides vat dyes of formula (I)

where

A represents the residue of formula (II)

and

B represents the residue of formula (III)

and m is from 0.5 to 1.5 and n is from 0.5 to 1.5 subject to the proviso that m+n is from 1.8 to 2.

The molar ratio between 2-amino-3,4-phthaloyl-7-bromoacridone and 1-aminoanthraquinone is therefore in the range from 1 :1 to 1 :0.2.

In preferred compounds of formula (I) m is from 1 to 1.5 and n is from 0.5 to 1 , subject to the proviso that m+n is from 1.8 to 2.

The compounds of formula (I) according to the present invention are obtainable for example by reacting chlorotriazine with 2-amino-3,4-phthaloyl-7-bromoacridone of formula (IV)

and with 1-aminoanthraquinone of formula (V)

using 1.5 to 2.5 mol of the compound of formula (IV) and 0.5 to 1.5 mol of the compound of formula (V) per mole of chlorotriazine.

The reaction can be carried out for example analogously to the process described in EP 0 057 375 A2 and is effected in particular in an inert solvent, for example chlorobenzene, dichlorobenzene or nitrobenzene, in the presence or absence of phenol. In addition, the reaction can also be carried out in phenol. The temperatures are preferably in the range from 80 to 150 ⁰ C, and in particular in the range from 90 to 140 ⁰ C.

The reaction can be carried out stepwise by reacting the cyanuric chloride first with 1-aminoanthraquinone and then with 2-amino-3,4-phthaloyl-7-bromoacridone or, conversely, first with 2-amino-3,4-phthaloyl-7-bromoacridone and then with

1-aminoanthraquinone, or directly as a one-pot reaction by reacting cyanuric chloride with a mixture of 1-aminoanthraquinone and 2-amino-3,4-phthaloyl-7-bromoacridone.

The vat dyes of general formula (I) according to the present invention are notable for bluish olive to bluish green hues which are in line with market expectations. The

same applies to their IR reflectance.

This result is surprising in that it was unforeseeable whether the compound of formula (IV) would fully react with chlorotriazine, i.e., whether the compounds of the present invention would be preparable at all at economically acceptable cost. Nor were the IR reflectance properties foreseeable.

The dyes of the present invention can therefore be used with advantage for dyeing and printing cellulosic fiber materials, in particular cotton.

All common vat dyeing and printing processes can be used. In the case of printing processes, the dyes of the present invention will prove particularly advantageous in pigment printing.

The dyeing and printing processes for which the dyes of the present invention are contemplated are exhaustively described in the literature and well known to one skilled in the art.

Example 1

A mixture of 1200 g of phenol and 210 g of 2-amino-3,4-phthaloyl-7-bromoacridone of formula IV (0.5 mol) and 46 g of 1-aminoanthraquinone of formula (V) (0.21 mol) and 48 g of cyanuric chloride (0.26 mol) is homogenized at 80 ⁰ C and heated to 125°C. The reaction batch is stirred at 125°C for five hours. After complete conversion of the reactants the reaction mixture is cooled down to 70 ⁰ C and diluted with 533 g of methanol and stirred at 60 ⁰ C for 20 min. The precipitated product is filtered and is washed phenol-free with methanol and methanol-free and salt-free with water. After drying, 269.5 g are obtained of dye which dyes in bluish green shades.

Products dyeing bluish olive to bluish green are also obtained on repeating the method described in Example 1 with the hereinbelow mentioned use quantities:

Example 8

A mixture of 300 g of phenol and 50 g of 2-amino-3,4-phthaloyl-7-bromoacridone of formula (IV) (0.12 mol) and 11.4 g of cyanuric chloride (0.06 mol) is homogenized at 60 ⁰ C and heated to 92°C. The reaction batch is stirred at 92°C for two hours. After complete conversion of the reactants, 11.5 g of 1-aminoanthraquinone of formula (V) (0.05 mol) are added and the reaction batch is heated to 140 ⁰ C and stirred at 140 ⁰ C for three hours. Subsequently, the reaction mixture is cooled to 70 ⁰ C and diluted with 533 g of methanol and stirred at 60 ⁰ C for 20 min. The precipitated product is filtered and washed phenol-free with methanol and methanol-free and salt-free with water. After drying, 48.9 g are obtained of dye which dyes in bluish green shades.

Example 9

A mixture of 450 g of phenol and 17.5 g of 1-aminoanthraquinone of formula (V) (0.08 mol) and 18.5 g of cyanuric chloride (0.1 mol) is homogenized at 60 ⁰ C and heated to 92°C. The reaction batch is stirred at 92°C for two hours. After complete conversion of the reactants, 80 g of 2-amino-3.4-phthaloyl-7-bromoacridone of formula (IV) (0.19 mol) are added and the reaction batch is heated to 140 ⁰ C and stirred at 140 ⁰ C for three hours. Subsequently, the reaction mixture is cooled to 70 ⁰ C and diluted with 300 g of methanol and stirred at 60 ⁰ C for 20 min. The precipitated product is filtered and washed phenol-free with methanol, methanol-free with water and phenol-free and salt-free with 1% aqueous sodium hydroxide solution. After drying, 79.6 g are obtained of dye which dyes in bluish green shades.