Bayer Aktiengesellschaft

Gunter Gehrke

Volker Hederich

Hans-Samuel Bien

Reinold Schmitz

Robert Kuth

Werner Kuhnel

Walter Hohmann

Hans-Gunter Otten

Horst Brandt

Helmut Herzog

Helmut Seidler

Werner Steinbeck

Dieter Wiegner

Rolf Muders

Karl H Duchardt

Mixtures of disperse dyestuffs

95-99% pure 4,5-dinitro-1,8-dihydroxyanthraquinone which is essentially free from by-products is obtained by 'direct nitration' of 1,8-dihydroxyanthraquinones or 1,8-dimethoxyanthraquinones if the concentrations of acid are chosen such that, when the nitration reaction and, if appropriate, the saponification reaction have ended, an 80-100% strength sulphuric acid is present, or such a sulphuric acid concentration is established by adding water, and the 4,5-dinitro-1,8-dihydroxyanthraquinone which crystallizes out is separated off.

Process for the preparation of 4,5-dinitro-1,8-dihydroxyanthraquinone

Cationic anthraquinone dyestuffs of the formula ##STR1## wherein R.sub.1 denotes hydrogen, alkyl or cycloalkyl,

Process for the preparation of cationic anthraquinone dyestuffs

Dimethoxyanthraquinones can be prepared in high purity and in good yield in an economic manner which does not pollute the environment when 1 part by weight of dinitroanthraquinone is reacted with 2-8 parts by weight of methanol and 0.5-1.5 parts by weight of potassium hydroxide until all of the nitro groups have been replaced; the reaction is preferably carried out in the presence of 0.05-0.5 part by weight of amidosulphonic acid.

Process for the preparation of dimethoxyanthraquinones

For dyeing and printing cellulose fibres which have been swollen with water-miscible swelling agents or mixed fibres containing these fibres, the fibres are treated with dyestuffs which are free from sulphonic acid groups and carboxylic acid groups, of the general formula ##STR1## wherein R represents optionally substituted C.sub.1 -C.sub.6 -alkyl, cyclohexyl, C.sub.1 -C.sub.4 -alkoxy, phenyl, benzyl, phenylethyl, phenylpropyl or phenoxy, or chlorine or bromine,

Process for dyeing and printing cellulose fibres

In order to dye and print cellulose fibres swollen with water-miscible swelling agents or mixed fibres containing these fibres, the fibres are treated with dyestuffs which are free from sulphonic acid groups and carboxylic acid groups, of the general formula ##STR1## wherein R denotes hydrogen or optionally substituted alkyl, aryl or acyl,

Fabrics of synthetic fibres, preferably polyester fibres, can be printed in clear blue shades in accordance with the transfer printing principle if dyestuffs of the formula ##STR1## wherein R represents an alkyl radical with 2-6 C-atoms, are used.

Transfer printing process

The invention relates to a process for the preparation of water-insoluble chlorine-containing diaminodihydroxyanthraquinone dyestuffs. The process consists in that 2,8-dichloro-1,5-dinitroanthraquinone and/or 2,5-dichloro-1,8-dinitroanthraquinone is warmed with sulphur in concentrated sulphuric acid having a maximum SO.sub.3 content of 20% - possibly in the presence of boric acid - the resulting compounds are, if appropriate, post-halogenated and/or alkylated, preferably in the same reaction batch. The main advantage of this process is that it starts from 1,6- and/or 1,7-dichloroanthraquinone, for which there was hitherto no industrial use, but which unavoidably also arise during the synthesis 1,5- and 1,8-dichloroanthraquinones.

Anthraquinone dyestuffs

The invention relates to mixtures of water-insoluble anthraquinone dyestuffs of the formula ##STR1## in which A and B are amino or hydroxyl

1-Amino-2-(bromophenoxy-alkoxy)-4-hydroxy anthraquinone dyestuffs

The invention relates to the preparation of anthraquinone disperse dyestuffs from aqueous solutions containing anthraquinone-sulphonic acid mixtures, especially from appropriate waste waters by treating such solutions with chloric acid/hydrochloric acid or their salts or activated halogene, isolating the halogenoanthraquinones thereby obtained, subjecting them to dinitration and warming the dinitrohalogenoanthraquinones thus obtained with elementary sulphur in sulphuric acid optionally in the presence of boric acid. The reaction products are .beta.-halogenated diaminodihydroxyanthraquinones which are suitable for the dyeing of polyesters and polyamides in blue shades with good fastness properties.

Process for the preparation of diamino-dihydroxy anthraquinone disperse

Anthraquinone dyestuffs of the formula ##SPC1## In which

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Cologne, Germany

Gunter Gehrke