Abstract: The preparation of anthraquinone imide compounds by condensation of anthraquinone compounds containing at least one primary amino group with halogenized aromatics or by condensation of halogenized anthraquinone compounds with primary aromatic amines, in the presence of a vat-dyeing catalyst and an acid-binding agent in an organic solvent, in which the organic solvent used is an alkyl benzoate.

Abstract: Quinophthalone derivatives of the formula I ##STR1## where the group A completes substituted or unsubstituted heteroaromatic rings and the group B completes a substituted or unsubstituted aromatic ring, are prepared by reacting a methyl-substituted heterocyclic compound of the formula II ##STR2## with an anhydride of an aromatic dicarboxylic acid of the formula III ##STR3## or the corresponding free dicarboxylic acid (IIIa) in the presence of an acid and of an organic solvent, the organic solvent used being an alkyl benzoate.

Abstract: Anthraquinone dyes I ##STR1## (Ar = aryl, A = anthraquinonyl) are prepared by reacting a aryldihalotriazine II ##STR2## (Hal = chlorine or bromine) with an aminoanthraquinone IIIA--NH.sub.2in an N--C.sub.1 --C.sub.4 -alkylpyrrolid-2-one or -piperid-2-one, N-di-C.sub.1 -C.sub.4 -alkylacetamide or -propionamide or urea derivatives of the formula IV ##STR3## (R = identical or different alkyl groups of from 1 to 4 carbon atoms which can also be linked together to form a 5- or 6-membered ring containing the urea group) as solvent.

Abstract: The preparation of 1-amino-2-carboxyanthraquinones I ##STR1## (X denotes hydrogen, chlorine or bromine) by oxidation, under alkaline conditions, of a 1-aminoanthraquinone substituted in the 2-position by an oxidizable carbo-organic radical followed by acidification of the reaction mixture, wherein a 1-amino-2-acetylanthraquinone II ##STR2## (Y denotes chlorine or bromine and n is equal to 0, 1 or 2) is reacted with a peroxide compound or oxygen as oxidizing agent.

Abstract: Solids are dispersed, comminuted or deagglomerated and classified in a single piece of equipment, a classifier jet mill representing a combination of a jet mill and a spiral flow classifier.

Abstract: 1-Nitroanthraquinone-2-carboxylic acid of the formula I ##STR1## is prepared by treating novel 2-substituted 1-nitroanthraquinones of the general formula II ##STR2## where R is --CH.dbd.CH--R.sup.1 or --CH.sub.2 --CHO, where R.sup.1 is C.sub.1 -C.sub.5 -dialkylamino or a cyclic 5- or 6-membered amine which may contain further hetero atoms, with oxidizing agents free of heavy metal.

Abstract: 1-Amino-2-(6'-hydroxyhexoxy)-4-hydroxyanthraquinone (I) is prepared from the corresponding 2-phenoxy- or 2-halo-anthraquinone compound and 1,6-hexanediol with or without a phenol in the presence of an alkaline agent at elevated temperatures by reacting, per mole of the anthraquinone compound, from 2 to 6 moles of 1,6-hexanediol in the presence of ethylene oxide adducts on phenols or alkanols and/or polyethylene glycols at from 125.degree. to 135.degree. C. and then heating the resulting reaction mixture at from 140.degree. to 150.degree. C., in the course of which the stage 1 byproducts, namely the 1',6'-bis(1-amino-4-hydroxyanthraquinonyloxy)hexane diether is cleaved into (I), leaving a diether level of .ltoreq.2% by weight in (I).

Abstract: Blue anthraquinonoid disperse dyes are prepared by reacting a 1-amino-4-nitroanthraquinonecarboxamide (II) with a cyanide in an aqueous medium in the presence of hydroxyl ion acceptors at above 20.degree. C. by a process in which the reaction is carried out in water at a pH of from 7.5 to 10.5 and in the presence of one or more quaternary ammonium salts at from 60.degree. to 100.degree. C.The process gives disperse dyes which are similar to C.I. Disperse Blue 87 and have similar color properties in high yields by an environmentally compatible process, the said disperse dyes having excellent properties.

Abstract: A process for the preparation of bisalkoxy(iso)violanthrenediones involves alkylating the corresponding bishydroxyl compounds in an organic reaction medium with methyl benzoate as the reaction medium.The ester can easily be regenerated and is stable under the reaction conditions.

Abstract: The dye is obtained by alkylating 16,17-dihydroxyviolanthrene-5,10-dione in a tertiary aliphatic or cycloaliphatic amine as solvent at from 100.degree. to 230.degree. C. in high yield and high purity.

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: 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: 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: Dimethylaminobenzenesulfonates are manufactured by reacting nitrobenzenesulfonates with formaldehyde and hydrogen in the presence of a hydrogenation catalyst containing a metal of atomic number from 24 to 29 and of phosphoric acid and water at a pH of from 2 to 3.5, at from 50 to 150.degree. C, under a pressure of at least 40 bars, with a residence time of from 1 to 15 minutes. The products are starting materials for the synthesis of dyes, especially of rhodamine dyes, oxazine dyes and reactive dyes, and also of pharmaceuticals and pesticides.

Abstract: Disclosed is a corrosion inhibitor for metal surfaces. The surface is contacted with an alkaline aqueous solution containing a reaction product of an aliphatic carboxylic acid, a polyhydroxy carboxylic acid and an alkanol amine.