Abstract: Azo colorants are prepared by conducting the diazotization of aromatic or hetaromatic amines or the azo coupling reaction or the diazotization and the azo coupling reaction in a microreactor.

Abstract: A monoazo compound synthesized using 2-hydroxynaphthalene-3,6-dicarboxylic acid (or salt thereof), an amide, an ureide or an ester thereof as a coupler is novel, and is superior in water resistance, chemical resistance and solvent resistance. The present invention provides such a novel azo compound and a process for producing the same.

Abstract: The monoazo compound represented by formula I is excellent in compatibility with, solubility in, and coloring power for, almost all water-immiscible organic liquids, has a low melting point, and is suitable for use to color molten plastics, synthetic fiber spinning solutions, etc., and to color thermal transfer ink. ##STR1## wherein R represents sec-butyl; Cp represents a coupling component residue.The dense solution of at least one kind of said monoazo compound in a hydrocarbon solvent diffuses and dissolves quickly and uniformly in coloring subjects such as petroleum products, and is capable of coloring fuel oil etc. to a desired distinguishable color density with small amounts.

Abstract: A monoazo lake pigment and a process for its production; the monoazo lake pigment excellent in clearness, transparency, gloss and tinting strength is obtained by coupling a diazo component which is an aromatic amine having a sulfonic acid group with a coupler component which contains .beta.-naphthol or .beta.-oxynaphthoic acid and adding a laking agent during or after the coupling reaction, the coupler component further containing 0.1 to 30 mol %, based the coupler component, of a compound of the following formula, ##STR1## wherein n=1 or 2.

Abstract: A monoazo lake pigment and use thereof; the monoazo lake pigment is obtained by subjecting to a coupling reaction a diazo component mixture containing a naphthalene-based or benzene-based amine having a soluble group and 0.1 to 20 mol %, based on said amine, of a naphthalene-based or benzene-based amine having no soluble group and a coupler component mixture containing either .beta.-naphthol or .beta.-oxynaphthoic acid and 0.1 to 30 mol %, based on said .beta.-naphthol or .beta.-oxynaphthoic acid, of at least one member selected from compounds of the following formulae (I) to (III), and carrying out a lake-forming reaction of a coupling reaction product during or after said coupling reaction, ##STR1## wherein each of X.sub.1, X.sub.2 and X.sub.3 is at least one water-insoluble group selected from the group consisting of a halogen atom, a lower alkoxy group, a lower alkyl group, a nitro group and an amino group substituted with a lower alkyl group.

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 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: Azo Pigments are made by subjecting a diazo component to an azo coupling reaction with the equivalent quantity of a coupling component difficultly soluble at less than 65.degree. C. in the aqueous/acid and aqueous/neutral pH-ranges. More specifically, an aqueous/acid-solution of the diazo component is continuously mixed at a temperature of less than 65.degree. C. within a period of less than 1 minute with the aqueous/alkaline solution of the coupling component and a predetermined pH between 2 and 9 is established by controlling the flow of the mass streams of diazo component and coupling component; in this way a portion of the coupling component is caused to undergo immediate reaction to the azo pigment to be made whereas the balance portion of the coupling component simultaneously commences precipitating as finely crystalline reactive matter, which is reacted in a post-reaction phase with unreacted diazo component to give the azo pigment to be made.

Abstract: Azo pigments are made by subjecting a diazo component to an azo coupling reaction with the equivalent quantity of a coupling component difficultly soluble at less than 65.degree. C. in the aqueous/acid and aqueous/netural pH-ranges. More specifically, an aqueous/alkaline solution of the coupling component is continuously mixed in a first reaction step with an aqueous solution of acetic acid, boric acid, phosphoric acid, hydrochloric acid or sulfuric acid at a temperature lower than 65.degree. C. within a period of less than 1 minute, during which the coupling component commenences precipitating at least partially as reactive matter; next, the suspension obtained is continuously mixed, in a second reaction step immediately following the first reaction step, with an aqueous/acid solution of the diazo component at a temperature of less than 65.degree. C.

Abstract: According to the invention, addition of one or more surfactants having a cloud point in aqueous solution to an aqueous suspension of an azo disperse dye gives after the isolation of the dye at a temperature above the cloud point aqueous press cakes containing a large amount of this dye.The direct processing of press cakes as obtained for example after the synthesis and isolation of azo disperse dyes to practical dispersions for use requires a minimum dye content in the press cakes. The minimum content is frequently not obtained when conventional methods of isolation are used, so that it is necessary to proceed via the indirect route of drying to obtain powders and redispersing the powders. By using the process according to the invention it is possible to cut out the costly indirect route or, if desired, to reduce the expense of drying to obtain powders by an appreciable margin.

Abstract: An azo lake pigment is obtained by coupling an aromatic diazo component having a sulfonic acid group with a mixture of 2-hydroxy-3-naphthoic acid and a 2-hydroxy-3-naphthoic acid derivative represented by formula [I] ##STR1## wherein R represents a hydrogen atom, a naphthalene residue, a cyclohexyl group, or a group of the formula ##STR2## in which each of X, Y and Z represents a hydrogen atom, a lower alkyl group, a lower alkoxy group, a halogen atom, an acetylamino group, a benzoylamino group, a carbomoyl group or a phenylcarbamoyl group, and X and Y together may form a cyclized benzimidazolone, benzthiazole or benzoxazole group,and laking the resulting dye with an alkaline earth metal salt or a manganese salt.

Abstract: Azo compounds of the formula I ##STR1## wherein X is --H, --CH.sub.3, --CF.sub.3, --NO.sub.2, --COOR.sub.1, --NHCOR.sub.2 or --COHN.sub.2, and R.sub.1 and R.sub.2 are as defined in claim 1, are suitable for pigmenting high-molecular organic material.

Abstract: Monoazo compounds of the formula ##STR1## in which one of the two substituents R.sub.1 or R.sub.2 or both substituents are C.sub.3 -C.sub.8 -alkyl or a group of the formula ##STR2## in which R.sub.3 and R.sub.4 are independently of each other hydrogen or C.sub.1 -C.sub.4 -alkyl and R.sub.5 is hydrogen, halogen or C.sub.1 -C.sub.4 -alkyl and the other of the two substitutents R.sub.1 or R.sub.2, when the two are not C.sub.3 -C.sub.8 -alkyl or a group of the formula (1a), is hydrogen, halogen or C.sub.1 -C.sub.4 -alkyl, and KK is the radical of a coupling component which is free of water-solubilizing groups the two described. These compounds can be used as dyes for dyeing or printing for example polyester fibre materials.