Abstract: The invention relates to three new crystal modifications (.gamma., .delta., .epsilon. modification) of C.I. Pigment Yellow 16 ##STR1## having their characteristic reflections in the X-ray diffraction spectrum. The new crystal modifications are prepared by heat treatment of the known .alpha. or .beta. modification in selected organic solvents.

Abstract: The production which is customary in practice of monoazo compounds based on dichloro- and trichloroanilines or disazo compounds of the chlorinated biphenyl series by conventional coupling methods meets with difficulties in that the resulting pigments are contaminated by traces of polychlorinated biphenyls.According to the invention, it has now been found that by addition of water-soluble olefins of the type ##STR1## (R =H, alk or Oalk; X =--COOR.sup.1, --CONHR.sup.2 or --NR.sup.3 COR.sup.4)in the azo coupling, the side reactions which form PCBs can be decidedly suppressed during synthesis of the pigments.

Abstract: The industrial preparation of C.I. Pigment Yellow 81 by conventional coupling methods has the disadvantage that traces of polychlorinated biphenyls are formed in the course of the reaction of the two components.The invention now provides that the addition of quaternary dialkyldiallylammonium compounds during the azo coupling will decisively suppress the PCB-forming secondary reactions during the pigment synthesis.

Abstract: The invention relates to monoazo pigments prepared from dichloroanilines as diazo components and CH-acidic coupling components of the acetoacetarylamide or naphthol series, these pigments only containing an extremely low level of polychlorinated biphenyls (PCBs) (at most 25 .mu.g per g of pigment).The process for preparing the pigments takes the form of an azo coupling in an aqueous medium, whereina) azo coupling is effected by adding the diazonium salt solution to a suspension or solution of the coupling component or by simultaneously metering the aqueous suspensions or solutions of the diazonium salt and of the coupling component into the reaction mixture,b) azo coupling is effected at a pH or within a pH range of less than pH 7 andb1) between pH 4 and 7 during and after azo coupling less than 0.

Abstract: Addition compounds which are suitable as dispersants for solids in organic media are obtained from polyepoxides based on novolaks having 3 to 11 nuclei and a mixture of aliphatic, aromatic and/or heterocyclic amines.

Abstract: Powdered azo pigments with improved rheological properties for use in paint systems on an alkyd/melamine, acrylic/melamine, acrylate/isocyanate or polyester/isocyanate basis, both of a conventional nature and also of a modern nature of the "high solids" type, to which--as appropriate before, during or after finishing--1 to 20% by weight of the active substance of a paint additive of the polyurethane series, prepared by reacting polyisocyanurates which still carry free isocyanate groups and are based on toluylene diisocyanate, hexamethylene diisocyanate or mixtures thereof, with (1) aliphatic mono- or polyhydroxycarbonylic acid C.sub.1 -C.sub.20 -alkyl esters (degree of polycondensation 2-50), (2) polyethylene glycols (molecular weight 500-1,500) and (3) 5- or 6-membered, saturated or unsaturated heterocyclic compounds which contain at least one nitrogen atom in the ring and reactive amino or hydroxy-C.sub.1 -C.sub.

Abstract: Process for improving the application properties of disazo pigments obtained by coupling bis-diazotized chlorine-substituted 4,4'-diaminobiphenyls with acetoacetylaminobenzenes, which includes adding sulfite ions to the pigment suspension obtained in the coupling and then heating for one half to two hours at 50.degree. to 100.degree. C. The process produces, above all in large scale industrial batches, a product of uniform quality and having acceptable fastness to solvents, overlacquering, migration and bleeding.

Abstract: Addition products formed from polymeric diphenylmethane 4,4'-diisocyanates, amines, monoactive and diactive polymers are suitable for use as dispersants for solids in organic media.

Abstract: The invention relates to a process for improving the application properties of Pigment Yellow 13. The crude pigment is heated in an aqueous suspension to temperatures above 100.degree. C. Pigment Yellow 13 thus obtained is particularly suitable for replacing lead-containing chrome yellow pigments of comparable shade.

Abstract: Process for the aftertreatment of the azo pigment of the formula ##STR1## C.I. PIGMENT ORANGE 36 wherein the crude pigment obtained after coupling is heated to temperatures from 100.degree. to 150.degree. C. in dry or wet condition in a solvent which is water-immiscible or not indefinitely water-miscible and the pigment is isolated in known manner. The pigment aftertreated in this way shows substantially improved hiding power while the same pigment prepared in the usual way has poor hiding power and can not be used in stoving lacquers.

Abstract: The preparation of 3-amino-1-phenylpyrazol-5-one by heating phenylhydrazine and a lower cyanoacetic acid alkyl ester in a polar solvent, using a lower alcoholate of an alkali metal as the condensation agent, leads to particularly high yields and quality, if the phenylhydrazine and 1 to 1.2 moles of the alcoholate are initially taken, the cyanoacetic ester is metered in and the reaction is carried out at 105.degree. to 140.degree. C., volatile alcohols which have been liberated from the ester and, if appropriate, from the alcoholate being distilled off at the reaction temperature. It is advantageous to employ the phenylhydrazine in an excess of up to about 200 mole % and to select, as the polar solvent, an alcohol or ether having a boiling point above 105.degree. C.

Abstract: A process for the purification of azo pigments, wherein the crude pigment is stirred for some time in an aqueous alkaline suspension in a pH range from 9 to 12, preferably from 11 to 12, at temperatures between 20.degree. to 80.degree. C and subsequently the crude pigment is filtered off and washed neutral. The pigments treated by this process show a clearer and more brilliant shade and are faster to bleeding when incorporated, for example, into a thermoplastic material than the untreated pigments.

Abstract: Monoazo compounds obtained by diazotising meta- or para-acylamino anilines and coupling on acetoacetylamino benzimidazolones are pigments of excellent fastness properties.

Abstract: A form of the disazo pigment C.I. 20040 having the formula 30% of ##STR1## IS SHOWN HAVING IMPROVED COVERING POWER, IMPROVED FLUIDITY IN LACQUER SYSTEMS AND HIGH LUSTER, WHICH IS CHARACTERIZED BY A SPECIFIC SURFACE OF 10 - 20, PREFERABLY 12 - 17 M.sup.2 /G AND A MAXIMUM IN GRAIN DIAMETER DISTRIBUTION BETWEEN 500 AND 1000 NM, AT LEAST 30 % OF ALL GRAINS HAVING A DIAMETER OF FROM 500 TO 1000 NM AND LESS THAN 25% OF ALL GRAINS HAVING A DIAMETER OR MORE THAN 1000 NM. This new pigment is obtained by isolating the pigment, after coupling, by stirring it out with alkali and, after having filtered it off and washed until neutrality, heating it to temperatures above 100.degree. C with an organic solvent which is immiscible with water or miscible with water to a limited degree only.

Abstract: Monoazo dyestuffs of the formula ##SPC1##Wherein R.sub.1, R.sub.2 and R.sub.3 are identical or different and are hydrogen, alkyl or alkoxy, preferably having 1 to 2 carbon atoms, or halogen, especially chlorine, X is hydrogen or halogen, preferably chlorine and A is acetoacetyl or and a process for preparing them by coupling diazotized amines of the general formula ##SPC2##With coupling components of the formula ##SPC3##Where R.sub.1, R.sub.2, R.sub.3, X and A have the above meaning. These new pigments may be used for dyeing and printing of material or synthetic materials. They have good fastness properties, especially an improved fastness to heat.

Abstract: A highly covering disazo pigment having the chemical constitution ##SPC1##Which is characterized by a specific surface of 12 - 30, preferably 15 to 25, m.sup.2 /g, a maximum of the grain size distribution of between 250 and 500 nm and a proportion of these grain sizes in the total distribution of 35 - 65 percent, preferably 45 - 60 percent. This new pigment form is obtained by heating the pigment obtained after coupling with a solvent which is immiscible with water or miscible with water to a limited degree only to temperatures above 100.degree.C.

Abstract: The disazo pigment of the formula ##SPC1##Characterized by a specific surface of 12 - 20, preferably 13 - 18 m.sup.2 /g, a maximum of the distribution of the grain sizes of between 500 and 1000 nm and a proportion of these grain sizes in the total distribution of between 35 and 65 %. This disazo pigment is obtained by isolating the pigment, after coupling, by stirring it out with alkali and, after having filtered it and washed it to neutrality, heating it to temperatures above 100.degree. C in a mixture of water and a solvent which is immiscible with water or miscible with water to a limited degree only.