Abstract: An azo pigment or a tautomer thereof represented by the following Formula (1), and having characteristic X-ray diffraction peaks at Bragg angles (2?±0.2°) of 6.5°, 7.1° and 21.8° in the CuK? characteristic X-ray diffraction.

Abstract: There is provided a pigment dispersion including an azo pigment or a tautomer thereof represented by the following Formula (1) and having characteristic X-ray diffraction peaks at Bragg angles (2?±0.2°) of 4.8°, 7.2° and 9.7° in a CuK? characteristic X-ray diffraction.

Abstract: Black disazo dyes of general formula (V) wherein A is a moiety of formula (VI) or of formula (VII) and B is a moiety of formula (VII) or of formula (IX) and wherein M, R1, R2, R3, R4, R5, R6, R7, R8, R9, R10, R11, R12, R13, R14, R15, R16, R17, R18, R19, R20, R21, R22, R23, and R24, are as defined in the specification, are excellent black dyes for dying and printing cellulose containing materials and textile materials and, in particular, for preparation of recording liquids for ink jet printing and for writing utensils.

Abstract: Black disazo dyes of general formula (V) wherein A is a moiety of formula (VI) or of formula (VII) and B is a moiety of formula (VIII) or of formula (IX) and wherein M, R1, R2, R3, R4, R5, R6, R7, R8, R9, R10, R11, R12, R13, R14, R15, R16, R17, R18, R19, R20, R21, R22, R23 and R24 are as defined in the specification, are excellent black dyes for dying and printing cellulose containing materials and textile materials and, in particular, for the preparation of recording liquids for ink jet printing and for writing utensils.

Abstract: Compounds of the general formula (I) a process for their preparation and their use for dyeing and/or printing organic substrates are described.

Abstract: The present invention relates to dyes of formula wherein D, R1, R2, R3, R4 and n are defined as in the claims, to the process for the preparation thereof and to the use thereof in dyeing or printing semi-synthetic and especially synthetic hydrophobic textile materials, more especially textile materials.

Abstract: There is provided an azo pigment having excellently good color reproducibility, dispersibility, and storage stability of pigment dispersions and having excellent hue and tinctorial strength. An azo pigment represented by the following formula (1) and having characteristic peaks at Bragg angles (2?±0.2°) of 7.2°, 13.4°, 15.0°, and 25.

Abstract: Compounds of the general formula (I) a process for their preparation and their use for dyeing and/or printing organic substrates.

Abstract: Compounds of the general formula (I) a process for their preparation and their use for dyeing and/or printing organic substrates are described.

Abstract: The invention relates to a dye of the general formula (I) where D is the residue of a diazo component; R1 is hydrogen, (C1-C6-alkyl, (C1-C4)-alkoxy, hydroxyl, halogen, —NHCHO, —NHCO(C1-C6)-alkyl, —NHCOaryl, —NHSO2(C1-C6)-alkyl or —NHSO2aryl; R2 is hydrogen, (C1-C6)-alkyl, (C1-C4)-alkoxy, phenoxy or halogen; R3 is hydrogen, (C1-C6)-alkyl, substituted (C1-C6)-alkyl, (C3-C4)-alkenyl or substituted (C3-C4)-alkenyl; or R2 and R3 combine to form the radical —C*H(CH3)CH2C(CH3)2—, where the carbon atom marked * is attached to the phenyl nucleus; R4 is hydrogen, (C1-C6)-alkyl or phenyl; R5 is vinyl or a group of the formula —CHR6COR7, where R6 is hydrogen, (C1-C6)-alkyl or phenyl; R7 is (C1-C6)-alkyl, substituted (C1-C6)-alkyl, phenyl or substituted phenyl; and X is C1-C5)-alkylene. The invention for relates to a process to prepare the dye and their use.

Abstract: To provide an azo pigment composition having extremely good hue and extremely good light fastness and showing excellent tinctorial strength (color density) and, preferably, to provide an azo pigment composition further containing an azo pigment having characteristic X-ray diffraction peaks at different positions or a tautomer thereof. An azo pigment composition which contains at least one azo pigment represented by the following formula (1) and having characteristic peaks at Bragg angles (2?±0.2°) of 7.2° and 25.

Abstract: To provide an azo pigment composition exhibiting very good hue and light fastness and having excellent tinctorial strength (color density) and preferably further provide an azo pigment composition containing an azo pigment having characteristic X-ray diffraction peaks at different positions or a tautomer thereof. An azo pigment composition comprising at least one kind of an azo pigment represented by formula (1) having characteristic X-ray diffraction peaks at Bragg angles) (2?±0.2°) of 7.6°, 25.6° and 27.

Abstract: Compounds of the general formula (I) a process for their preparation and their use for dyeing and/or printing organic substrates.

Abstract: In C. I. pigment red 57:1 of the present invention, the total content of 3-hydroxy-2-naphthoic acid and a metal salt thereof, which is measured by quantitative analysis using liquid chromatography, is 2,500 ppm or less as converted into the 3-hydroxy-2-naphthoic acid.

Abstract: The invention relates to novel dyes of the formula (1) in which D represents a phenyl or naphthalene residue which is substituted by one or two sulphonic Acid or carboxylic acid groups and, optionally, by one or two groups selected from C1-C4alkyl, hydroxyl and nitro, each R1 and R2, independently, represent hydrogen or, a C1-C4alkyl group, R?1 represents hydrogen, hydroxyl, C1-C4alkyl or C1-C4hydroxyalkyl, R3 represents hydrogen, C1-C4alkyl or phenyl, which is unsubstituted or substituted by one or two groups selected from C1-C4alkyl, C1-C4alkoxy, halogen, hydroxyl, —NH2, nitro, —SO3M and —CO2M and M represents hydrogen, an alkaline or alkaline earth metal, ammonium or ammonium that is mono-, di-, tri- or tetrasubstituted by C1-C4alkyl or C2-C4hydroxyalkyl or a polyglycolammonium cation and also known dyes of formula (5), in which D? represents a phenyl or naphthalene residue which is substituted by one or two sulphonic acid or carboxylic acid groups and, optionally, by one or two groups selected from C1-C4a

Abstract: Radiation curable compositions, such as UV curable ink compositions, contain a polymeric dispersant, a curable material, and a nanoscale pigment particle composition including an organic monoazo laked pigment including at least one functional moiety, and a sterically bulky stabilizer compound including at least one functional group, wherein the functional moiety of the pigment associates non-covalently with the functional group of the stabilizer; and the presence of the associated stabilizer limits the extent of particle growth and aggregation, to afford nanoscale-sized pigment particles.

Abstract: A process for preparing nanoscale azo pigment particles includes providing an organic pigment precursor that contains at least one functional moiety, providing a sterically bulky stabilizer compound that contains at least one functional group, and carrying out a chemical reaction to form a pigment composition in a microreactor or micromixer, whereby the functional moiety found on the pigment precursor is incorporated within the pigment and non-covalently associated with the functional group of the stabilizer, so as to allow the formation of nanoscale-sized pigment particles and the production of such in a microreactor under laminar or turbulent flow conditions without clogging.

Abstract: Compounds of the general formula (I) a process for their preparation and their use for dyeing and/or printing organic substrates.

Abstract: The invention relates to novel dyes of the formula (1) in which D represents a phenyl or naphthalene residue which is substituted by one or two sulphonic Acid or carboxylic acid groups and, optionally, by one or two groups selected from C1-C4alkyl, hydroxyl and nitro, each R1 and R2, independently, represent hydrogen or, a C1-C4alkyl group, R?1 represents hydrogen, hydroxyl, C1-C4alkyl or C1-C4hydroxyalkyl, R3 represents hydrogen, C1-C4alkyl or phenyl, which is unsubstituted or substituted by one or two groups selected from C1-C4alkyl, C1-C4alkoxy, halogen, hydroxyl, —NH2, nitro, —SO3M and —CO2M and M represents hydrogen, an alkaline or alkaline earth metal, ammonium or ammonium that is mono-, di-, tri- or tetrasubstituted by C1-C4alkyl or C2-C4hydroxyalkyl or a polyglycolammonium cation and also known dyes of formula (5), in which D? represents a phenyl or naphthalene residue which is substituted by one or two sulphonic acid or carboxylic acid groups and, optionally, by one or two groups selected from C1-C4a

Abstract: A nanoscale pigment particle composition includes an organic monoazo laked pigment including at least one functional moiety, and a sterically bulky stabilizer compound including at least one functional group, wherein the mono-azo laked pigment includes a nono-azo dye molecule laked with a divalent metal cation; the functional moiety associates non-covalently with the functional group; and the presence of the associated stabilizer limits the extent of particle growth and aggregation, to afford nanoscale-sized pigment particles. Non-aqueous dispersion compositions, such as ink compositions, contain a polymeric dispersant, an organic liquid, and the nanoscale pigment particle composition.

Abstract: A nanoscale pigment particle composition includes an organic monoazo laked pigment including at least one functional moiety, and a sterically bulky stabilizer compound including at least one functional group, wherein the functional moiety associates non-covalently with the functional group; and the presence of the associated stabilizer limits the extent of particle growth and aggregation, to afford nanoscale-sized pigment particles.

Abstract: A nanoscale pigment particle composition includes an organic monoazo laked pigment including at least one functional moiety, and a sterically bulky stabilizer compound including at least one functional group, wherein the functional moiety associates non-covalently with the functional group; and the presence of the associated stabilizer limits the extent of particle growth and aggregation, to afford nanoscale-sized pigment particles.

Abstract: A monoazo lake pigment composition containing a monoazo lake pigment obtained from a laked pigment aqueous slurry prepared by conducting coupling of a diazo component obtained by diazotizing an aromatic amine having a soluble group and a coupler component and conducting laking after or simultaneously with the coupling, wherein the laking is carried out in the presence of a water-soluble acrylic polymer in an amount of 0.1 to 40 parts by weight per 100 parts of the above coupler component, and a gravure ink containing the above pigment composition and a gravure ink vehicle.

Abstract: This invention relates to azo pigments of general formula (I) wherein D represents the radical of a diazo component; R1 and R2 are the same or different and represent hydrogen, a C1-C4 alkyl radical which is optionally substituted by hydroxy, amino, halogen or methoxy, or a (C6-C10) aryl radical which is optionally substituted by one, two or three substituents from the group C1-C4 alkyl, C1-C4 alkoxy, F, Cl, Br, CF3, NO2, OH, CONH2, CONH(C1-C4 alkyl), CON(C1-C4 alkyl)2, COO(C1-C4 alkyl), SO2NH2, SO2NH(C1-C4 alkyl) and SO2N(C1-C4 alkyl)2, provided that R1 and R2 do not simultaneously represent hydrogen; R4 represents hydrogen, C1-C4 alkyl, halogen, trifluoromethyl, C1-C4 alkoxy, NO2, or CN; and n represents 1, 2 or 3

Abstract: SOD and other active oxygen inhibitors are directly applied in combination with a barrier material at local sites of tissue injury to prevent or decrease formation of adhesions and undesirable proliferation of cells. Preferred barrier materials are polymeric hydrogels providing controlled release of AOI which are directly applied to the afflicted tissue. Examples demonstrate the effects of SOD on pelvic adhesions in the rat when administered by intraperitoneal (I.P.) bolus and by localized sustained release from a topically applied hydrogel system.

Abstract: The invention relates to six new crystal polymorphs, &agr; (alpha), &bgr; (beta), &ggr; (gamma), &dgr; (delta), &zgr; (zeta), and &eegr; (eta), of the disazo colorant of the formula I, having characteristic reflections in the X-ray diffraction spectrum. The novel crystal polymorphs are prepared by treatment in organic solvents.

Abstract: A method for the production of diazomethane comprising the steps of a) feeding a base and a diazomethane precursor into a reactor vessel; b) generating gaseous diazomethane by allowing the base and the gaseous diazomethane precursor to react; and c) removing the gaseous diazomethane using a diluent gas.

Abstract: There is provided a process for the production of a compound of formula I, 1

Abstract: The invention provides a process for preparing azo colorants which comprises spraying one or more coupling components individually or in a mixture and one or more compatible diazonium salts individually or in a mixture, in their solution or suspension form through nozzles to a point of conjoint collision in a reactor chamber enclosed by a housing in a microjet reactor, a gas or an evaporating liquid being passed into the reactor chamber through an opening in the housing for the purpose of maintaining a gas atmosphere in the reactor chamber, and the resulting product solution or suspension and the gas or the evaporated liquid being removed from the reactor through a further opening in the housing by means of overpressure on the gas entry side or underpressure on the product and gas exit side.

Abstract: Disclosed are compositions comprising one or more compounds characterized by the formula: ##STR1## wherein Ar is an aromatic moiety having at least one substituent which is an acid group or salt thereof; X is a hydrocarbyl, carboxylic acid ester, sulfonic acid ester, carboxylic acid amide or sulfonic acid amide group; each Y is independently a hydrocarbyl, halogen, hydrocarbyloxy, carboxylic acid ester, sulfonic acid ester, carboxylic acid amide, imidazolone, sulfonic acid amide or nitro group; and a is 1, 2 or 3. Also disclosed is a process for preparing azo dyes which comprises coupling (i) at least one diazonium component of one or more aromatic amines containing at least one sulfonic acid group or carboxylic acid group, or salts thereof; with (ii) at least one coupling component represented by the formula: ##STR2## wherein X, Y and a are as defined above. The dye compositions prepared by this process and the azo pigments derived from such dyes are also disclosed.

Abstract: Compound of the general formula (I) ##STR1## in which X is an O or S atom or an imino group,Y is an O atom or an imino group,R.sub.1 and R.sub.2 are a hydrogen atom, C.sub.1 -C.sub.4 -alkyl, an unsubstituted phenyl group or a substituted phenyl group having 1 to 5 substituents from the group consisting of C.sub.1 -C.sub.4 -alkyl, C.sub.1 -C.sub.4 -alkoxy, halogen, nitro, cyano, hydroxyl, CF.sub.3, CONH.sub.2, CONH(C.sub.5 -C.sub.6 -cycloalkyl), CON(C.sub.1 -C.sub.4 -alkyl).sub.2, CONH(C.sub.1 -C.sub.4)-alkyl, COO(C.sub.1 -C.sub.4)-alkyl, COO(C.sub.5 -C.sub.6 -cycloalkyl) and CONH(phenyl), with the proviso that at least one of the radicals R.sub.1 or R.sub.2 has one of the meanings mentioned which differ from hydrogen,R.sub.3 is a hydrogen atom, a trifluoromethyl group, a halogen atom or a C.sub.1 -C.sub.4 -alkyl, a C.sub.1 -C.sub.4 -alkoxy, a nitro or a cyano group andR.sub.4 and R.sub.5 independently of one another are a hydrogen atom, C.sub.1 -C.sub.

Abstract: The invention discloses a process for the preparation of azo dyes using an aminodiphenylamine as diazo component. The process comprises reacting the amine, an alkali metal nitrite and a mineral acid continuously in the temperature range from 35.degree. to 65.degree. C. to give the diazo compound, using a 3 to 15% excess of alkali metal nitrite, and thereafter coupling the diazo compound to a coupling component. Azo dyes of superior quality constancy and in high yield are obtained by the novel process.

Abstract: Dyestuffs of the formula ##STR1## in which D is the radical of an aromatic or heterocyclic diazo component andK is the radical of an aromatic or heterocyclic coupling component, or is the radical of an active methylene compound,are obtained in an ecologically advantageous manner by reacting an aromatic or heterocyclic diazo components of the formulaD--NH.sub.2and a coupling component of the formulaH--Kwith a nitrite, for example NaNO.sub.2, in the presence of CO.sub.2 at a pressure of 5-100 at. The process is suitable in particular for the preparation of concentrated dye-stuff solutions, because expensive operations, such as, for example, pressure permeation and reverse osmosis, can be omitted.

Abstract: An ecologically and economically advantageous process for preparing a disazo pigment of the formula (I) or a mixture of said disazo pigments ##STR1## where D.sup.1 and D.sup.2 are identical or different and each is unsubstituted phenyl, phenyl with from 1 to 5 substituents, unsubstituted naphthyl, naphthyl with from 1 to 3 substituents, unsubstituted anthraquinonyl, anthraquinonyl with from 1 to 3 substituents, or a radical of a fused aromatic heterocycle which contains from 1 to 3 identical or different heteroatoms from nitrogen or oxygen and sulfur and is unsubstituted or has from 1 to 3 substituents,R.sup.1 and R.sup.2 are identical or different and each is hydrogen, halogen, C.sub.1 -C.sub.4 -alkyl, C.sub.1 -C.sub.4 -alkoxy, C.sub.1 -C.sub.

Abstract: Dyestuffs of the formula ##STR1## in which D is the radical of an aromatic or heterocyclic diazo component andK is the radical of an aromatic or heterocyclic coupling component, or is the radical of an active methylene compound,are obtained in an ecologically advantageous manner by reacting an aromatic or heterocyclic diazo components of the formulaD--NH.sub.2and a coupling component of the formulaH--Kwith a nitrite, for example NaNO.sub.2, in the presence of CO.sub.2 at a pressure of 5-100 at. The process is suitable in particular for the preparation of concentrated dye-stuff solutions, because expensive operations, such as, for example, pressure permeation and reverse osmosis, can be omitted.

Abstract: Dyestuffs of the formula ##STR1## in which D is the radical of an aromatic or heterocyclic diazo component andZ is the radical of an aromatic or heterocyclic coupling component,are obtained in an ecologically advantageous manner by reacting an aromatic or heterocyclic diazo components of the formulaD--NH.sub.2and a coupling component of the formulaH--Z.sub.1with a nitrite, in the presence of CO.sub.2 at a pressure of 5-100 at. The process is suitable in particular for the preparation of concentrated dyestuff solutions, because expensive operations, such as, for example, pressure permeation and reverse osmosis, can be omitted.

Abstract: Disclosed are dye compositions of the formula ##STR1## wherein Cp and Cp' are each coupler compounds of the formula ##STR2## wherein the --COOH group and the --OH group can be in any position on either ring, provided that in the naphthalene ring system there is present least one hydrogen activated through resonance by the --OH group for an electrophilic aromatic substitution coupling reaction, n represents the number of substituents on the rings and is a number of from 0 to 8, and R represents the substituent groups on the ring, wherein each R is independently selected from the group consisting of hydroxyl groups, alkyl groups, substituted alkyl groups, aryl groups, substituted aryl groups, aryl-alkyl groups, substituted aryl-alkyl groups, halogen atoms, and nitro groups. Also disclosed are aqueous ink compositions containing the dyes, processes for making the dyes, processes for making the inks containing the dyes, and printing processes employing the inks.

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: Sulfonic acids are reacted with sodium nitrite to form new compositions specifically nitrosyl sulfonates. The nitrosyl sulfonates are useful in reacting with a dye base to form a diazo composition which can in turn react with a coupling agent to form a diazo dye. The nitrosyl sulfonate can also be used to react with an aromatic composition to nitrosoate an aromatic composition. These reactions are particularly useful in the formation of a dispersed dye because the dye can be formed directly in a nonpolar organic solvent and can be used without purification of the dye product. Particularly useful is the nitrosyl dodecyl benzene sulfonate since the formed product is soluble in nonpolar solvents and all reaction products remain in solution and aid with the dyeing of fabrics.

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: Monoazo pigments are provided which have improved properties achieved by incorporating certain azomethine compounds. The pigment compositions are prepared by reacting a primary amine-terminated alkylene oxide polymer and an acetoacetanilide to form an azomethine coupler and subsequently preparing the monoazo pigment composition by reacting the desired diazo component and coupling component in the presence of the azomethine coupler so as to form an azomethine composition of matter and the desired pigment.

Abstract: A monoazo dyestuff composition comprising at least two different individual compounds of the formula ##STR1## wherein R.sup.1 and R.sup.2, independently of each other, are linear or branched alkyl having 1 to 4 carbon atoms and R is linear or branched alkyl having 1 to 5 carbon atoms, and where said individual compounds differ from each other in at least the R moiety, has improved dyeing properties compared with the individual dyestuffs when used to dye or print hydrophobic fiber materials.

Abstract: The invention describes a process for the preparation of formulations of water-insoluble to sparingly soluble azo dyes by simultaneous diazotization and coupling in a single step reaction, filtering the dye dispersion and, if desired, drying the dyestuff, which process comprises carrying out said simultaneous diazotization and coupling by intimately mixing the aqueous solution or suspension of the reactants, in the presence of one or more surface-active agents, concentrating the dilute dye dispersion by membrane separating methods, and at the same time at least partially removing salt and/or acid from the dispersion and converting it into a storage stable liquid formulation or, by drying, into a solid dye formulation.

Abstract: The invention relates to a continuous process for the preparation of cationic azo or hydrazone dyes from heterocyclic diazo components and coupling components. The diazo component is diazotised in water and an acid, the diazo solution is coupled with the coupling component and continuously alkylated, preferably using sufficient acid that, after the alkylation, a two-phase system forms, consisting of an aqueous solution which is substantially free from dye and a highly concentrated oil phase or solid dye.

Abstract: Liquid formulations of basic azo dyes are prepared from unsubstituted or C.sub.1 -C.sub.4 -alkyl- or C.sub.1 -C.sub.4 -alkoxy-substituted m-phenylenediamine by diazotizing and coupling in carboxylic acid solution, which comprises performing the reaction with 0.76 to 0.95 mole of nitrile, calculated as nitrous acid and based on 1 mole of m-phenylenediamine, and then heating the resulting reaction mixture at from 60.degree. C. to the boiling point of the reaction mixture.

Abstract: Disazo dyes which are useful for dyeing and printing, of the formula ##STR1## in which: D is the radical of a substituted or unsubstituted, homocyclic or heterocyclic diazo component, V.sup.1 and V.sup.2 independently of one another are hydrogen, substituted or unsubstituted C.sub.1 -C.sub.4 alkyl or C.sub.1 -C.sub.4 alkoxy, halogen or cyano, X is hydrogen, substituted or unsubstituted C.sub.1 -C.sub.4 alkyl or C.sub.1 -C.sub.4 alkoxy, halogen, cyano or a group of the formula --NH--CHO, --NH--CO--NH.sub.2, --NH--CO--NH--Q or --NH--CO--(0).sub.m --Q in which m is zero or 1 and Q is substituted or unsubstituted C.sub.1 -C.sub.4 alkyl or phenyl, Z is C.sub.1 -C.sub.4 alkyl--CO--, --CN, --COO--C.sub.1 -C.sub.4 alkyl, --CONH.sub.2 or --CO--C.sub.6 H.sub.5, R.sup.1, R.sup.2 and R.sup.3 independently of one another are in each case a substituted or unsubstituted alkyl radical or R.sup.1 and R.sup.2, together with the nitrogen atom linking them, or R.sup.1, R.sup.2 and R.sup.

Abstract: Disclosed is a process for continuous preparation of aromatic diazonium fluoride salts wherein diazotizable aromatic primary amines are continuously diazotized in a reactor containing a plurality of sequential reaction zones, wherein a portion of the diazotization agent is continuously injected into each of the reaction zones.

Abstract: Azo dyes of the formula ##STR1## or tautomers thereof, wherein Z is N,S or CH,X is O,S,NR.sup.2 or N, V is N or CH, W is N or C, K is a coupling component from the group consisting of acylacetarylamides, phenols, pyridones, quinolines, pyrazoles, indoles, diphenylamines, aminopyridines, pyrimidines, pyrimidones, naphthols, naphthylamines, aminoathiozoles, thiophenes and hydroxypyridines, R is unsubstituted or substituted alkyl or alkenyl, R.sup.1 is hydrogen, C.sub.1 -C.sub.6 alkyl, C.sub.1 -C.sub.4 alkoxy, halogen, nitro, --CN, --NHR.sup.2, --NH--acyl, phenoxy, --COOR.sup.2, --COOR.sup.2 --CONHR.sup.2 or substituted or unsubstituted phenyl, R.sup.2 is hydrogen, substituted or unsubstituted C.sub.1 -C.sub.6 alkyl or substituted or unsubstituted phenyl, D is a 1,4-phenylene radical which can be substituted further and AN.THETA.

Abstract: The invention relates to an automatically controlled continuous method of eliminating excess nitrite in diazotization solutions of aromatic amines, which comprises controlling the addition of the agent employed for eliminating the nitrite ions by means of an electrochemically controlled variable.The process permits a smooth monitoring of the nitrite ion concentration in diazotization solutions. It is advantageous that the determination of the electrochemical controlled variable is almost instantaneous and that the addition of agent for removing nitrite ions can be controlled in simple manner via the fluctuations in the potential.

Abstract: An improved process for the production of 2-stilbylnaphthotriazole optical bleaches which involves diazotizing aminostilbene 2-sulfonic acids, coupling the thus formed diazonium salt with naphthylamino-sulfonic acid to form the stilbylnaphthyl monoazo salt by adding the naphthylamino-sulfonic acid to the diazonium salt from the diazotization, neutralized to a pH in the range of 6-8, in the presence of 2-butoxyethanol, oxidizing said monoazo salt to form the 2-stilbylnaphthotriazole compounds with air in an aqueous alkaline medium containing butoxyethanol and isolating and recovering said 2-stilbylnaphotriazole optical bleaches as their sodium salts.