Abstract: 4,4',7,7'-Tetrachlorothioindigo pigments of high color strength are prepared by oxidizing 3-hydroxy-4,7-dichlorothionaphthene or a mixture of tetrachlorothioindigo and hydroxydichlorothionaphthene in aqueous alkaline suspension with a salt of a nitro-aromatic sulfonic acid, in the presence of a high-boiling, water-immiscible or only slightly water-miscible aromatic liquid, at from 40.degree. to 100.degree. C., and heating the organic suspension to 110.degree.-180.degree. C. Pigmentary forms of tetrachlorothioindigo are isolated which give deep colorations of high brilliance when reduced with white pigments.

Abstract: A transparent pigmentary form of 4,4',7,7'-tetrachlorothioindigo is prepared by oxidizing the leuco compound of tetrachlorothioindigo in aqueous alkaline suspension, in the presence of a dithionite, at from 20.degree. to 100.degree. C., with simultaneous exposure to shearing forces. Preferably, the oxidation is carried out in the presence of a surfactant.The pigment obtained gives brilliant, transparent full-shade colorations, while white reductions have a deep pure reddish hue.

Abstract: A vat dye obtained by heating a condensation product, which itself has been prepared by heating 3,9-di-(1-anthraquinonylamino)-benz[d,e]anthrone in an aluminum chloride/picoline or aluminum chloride/quinoline melt in the presence of sulfuryl chloride or thionyl chloride, in a melt of an alkali metal hydroxide in an alcohol or glycol or aqueous glycol.The dye gives deep clear brown dyeings having good fastness characteristics.

Abstract: A process for the preparation of pigmentary forms of bromoisoviolanthrone, wherein the leuco compound is oxidized in an aqueous alkaline medium, in the presence of a surfactant, at from 10.degree. to 100.degree. C., with exposure to shearing forces.The pigment obtained gives full-shade colorations which are very transparent and very brilliant, while in white reductions very deep colorations are obtained.

Abstract: A process for the preparation of pigmentary forms of perylene-3,4,9,10-tetracarboxylic acid diimide, wherein the diimide is converted to the leuco compound and the latter is oxidized in aqueous suspension, either with exposure to shearing forces in the presence of surfactants, or in the absence of shearing forces and in the presence of non-ionic surfactants, or of mixtures of non-ionic and anionic surfactants.The perylenetetracarboxylic acid diimide pigments give deep, brilliant and transparent full-shade colorations. In white reductions, they give distinctly reddish colorations.

Abstract: In a process for the preparation of 1-amino-2-phenoxy-4-hydroxyanthraquinone by reacting 1-amino-2-halogeno-4-hydroxyanthraquinone with a phenol in an alkaline aqueous medium at an elevated temperature, the improvement that 1-amino-2-chloro-4-hydroxyanthraquinone is reacted in aqueous suspension, at a pH of from 9 to 13 and at from 120.degree. to 150.degree. C., with the phenol in the presence of(a) ammonium salts N.sup..sym. (R).sub.4 A.sup..crclbar., wherein one or more R's are linear or branched C.sub.4 -C.sub.20 -alkyl or C.sub.7 -C.sub.10 -phenylalkyl and the remaining R or R's may also be phenyl or N.sup..sym. (R).sub.3 may be pyridinium, and A.sup..crclbar. is one equivalent of an anion, of(b) ethylene oxide/propylene oxide block copolymers or of(c) oxyethylation products of alkylphenols, of alkenylamines, of alkylamines or of alkanols. A very pure product is obtained, in high yield.

Abstract: A process for the preparation of transparent pigmentary forms, of high tinctorial strength, of perylene-3,4,9,10-tetracarboxylic acid bis-p-phenetidide and bis-p-chloroanilide, in which the diimide concerned is converted to the leuco compound, and the latter, with or without prior isolation, is then oxidized in aqueous suspension in the presence of surfactants or while exposed to shearing forces in the presence or absence of surfactants, after which the pigment is isolated.The pigments give highly transparent very pure colorations when used unreduced, while in white reductions they give very deep colorations with substantially more yellowish hues than those given by the prior art pigments.

Abstract: In a process for the manufacture of 1-amino-2-bromo-4-hydroxyanthraquinone by hydroxylating previously prepared and isolated 1-amino-2,4-dibromoanthraquinone in sulfuric acid in the presence of boric acid at from 110.degree. to 130.degree. C., the improvememt that 1-aminoanthraquinone is brominated (from 1.5 to 2.1 moles of bromine per mole) in sulfuric acid of from 50 to 85 percent strength at from 80.degree. to 130.degree. C., the reaction mixture is brought to a concentration of from 96 percent strength sulfuric acid to 5 percent strength oleum by adding oleum; and the dibromo compound is then hydroxylated in the presence of boric acid. Very pure 1-amino-2-bromo-4-hydroxyanthraquinone, which can be used for all purposes, is obtained in a high yield.

Abstract: A process for the manufacture of a red pigment from perylene-3,4,9,10-tetracarboxylic acid N,N'-bis-methylimide which has been obtained by methylating the corresponding diimide or by fusing naphthalic acid N-methylimide with an alkali metal hydroxide which comprises vatting a suspension of N,N'-bis-methylimide dye with 0.5-1.5 times by weight of an alkali metal dithionite in the presence of up to 4 times by weight of an alkali metal hydroxide relative to the quantity of the dithionite, at a temperature of from room temperature to 100.degree. C., to obtain the corresponding leuco compound, cooling the resulting solution to 20.degree.-40.degree. C., isolating and washing the leuco compound with fresh vatting solution until the solution is virtually colorless and clean and then oxidizing the leuco compound.

Abstract: An .alpha.-indanthrone pigment having improved tinctorial and technological properties is produced by swelling .gamma.-indanthrone in sulfuric acid of from 73 to 80 percent strength by weight at from 20.degree. to 50.degree. C. in the presence of from 0.1 to 20% by weight, based on indanthrone, of a hydroxylammonium salt, a hydrazinium salt, amidosulfonic acid, urea, a salt of urea, formaldehyde or paraformaldehyde or a mixture of these. After precipitation in water which may or may not contain a surfactant, at below 50.degree. C., an .alpha.-indanthrone pigment of high tinctorial strength is obtained, which gives clear and pure colorations and is easily dispersible.

Abstract: In a process for the manufacture of 2-amino-3-bromoanthraquinone by heating 2-aminoanthraquinone with bromine (in the molar ratio of 1:1) in sulfuric acid, while mixing, the improvement wherein crude 2-aminoanthraquinone, in sulfuric acid of from 60 to 90 percent strength by weight, which contains from 10 to 15% by weight of an alkanecarboxylic acid of 3 or 4 carbon atoms or a mixture of such acids, is heated with from 1 to 1.05 moles of bromine per mole of 2-aminoanthraquinone at from 130 to 150.degree. C. The 2-amino-3-bromoanthraquinone which is isolated may be used for the manufacture of dyes. It is at least as pure as that obtained from purified 2-aminoanthraquinone by the process of the prior art.

Abstract: Direct production of 1,9-anthrapyrimidine-2-carboxylic acid-1'-anthraquinonylamide in pigmentary form by reaction of 1,9-anthrapyrimidine-2-carboxylic acid chloride with 1-amino-anthraquinone in a polar water-miscible aprotic solvent. The dye is obtained in a high yield and in a very finely divided and pure form. The isolated reaction product may be used direct as a pigment.