Bayer Aktiengesellschaft

Helmut Seidler

Klaus Wunderlich

Walter Hohmann

Hans-Samuel Bien

Gunter Gehrke

Helmut Herzog

Manfred Soll

Heinrich Leister

Sulphur dyestuffs which can be obtained by sulphurizing, in a manner which is in itself known, the residual mixtures obtained on dinitrating anthraquinone or on dinitrating by-products from the preparation of 1-nitroanthraquinone and partially isolating 1,5- and 1,8- and, if appropriate, 1,6- and 1,7-dinitroanthraquinones, optionally after prior reduction and/or hydroxylation and/or introduction of nitro groups, and their use in dyeing cellulose or material containing cellulose.

Sulphur dyestuffs

Coordinatively hexavalent complex salts of trivalent cobalt, in which four of the six coordination positions on the cobalt are occupied by the doubly negatively charged phthalocyanine ring system and the remaining two coordination positions are each occupied by an amine from the series of primary, secondary or tertiary aliphatic, aromatic or heterocyclic monoamines or polyamines and which are obtained by reaction of cobalt phthalocyanine compounds with primary, secondary or tertiary, aliphatic, aromatic or heterocyclic amine are prepared according to an improved process in that the cobalt phthalocyanine compounds used are those in which the central cobalt atom is present in the trivalent state, and which contain anions, bonded in the form of salts, from the series fluoride, chloride, bromide and iodide.

Process for the preparation of complex compounds of the cobalt

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

A process has been invented for the preparation of 1,5-dichloroanthraquinone which comprises reacting 1,5-dichloroanthraquinone with chlorine in the presence of at least 50% by weight of liquid phthalic anhydride, relative to the weight of 1,5-dinitroanthraquinone employed. The 1,5-dichloroanthraquinone is known to be a valuable starting material for the preparation of various dyestuffs.

Process for the preparation of 1,5-dichloroanthraquinone

A process has been developed for the mononitration of anthraquinone to 1-nitroanthraquinone with nitric acid/sulphuric acid mixtures wherein anthraquinone is nitrated in a nitric acid/sulphuric acid mixture, in which the weight ratio of nitric acid to sulphuric acid is about 1:1 to about 2:1, in which the weight ratio of sulphuric acid to anthraquinone is about 0.5:1 to about 1:1 and in which the weight ratio of sulphuric acid to water is about 2.5:1 to about 5.5:1, the weight ratios relating to the sum of the materials employed, at temperatures in the range from about 45.degree. to 70.degree. C. until the anthraquinone content is less than 3% by weight, relative to the sum of the anthraquinone compounds.

Process for the mononitration of anthraquinone

Polycyclic dyestuffs of the formula ##SPC1## Wherein R.sub.1 and R.sub.2 represent alkyl, cycloalkyl, aralkyl or aryl or together form a ring which is optionally interrupted by hetero-atoms and wherein both the benzene nucleus A and the said radicals R.sub.1 and R.sub.2 can carry non-ionic radicals customary in dyestuff chemistry, and their use for the dyeing of organic materials, especially synthetic fiber materials. Dyeings obtained show good general fastness properties.

Growing community of inventors

Bonn, Germany

Helmut Seidler