Hoechst Aktiengesellschaft

Hasso Hertel

Willy Gronen

Klaus Hunger

Erich Feess

Heinrich Frolich

Rudolf Kostka

Horst Curtius

Paul Karacsonyi

Hans Kaiser

Peter Frey

Adolf Trampusch

Bisdiazonium salts of the formula (1) ##STR1## in which R denotes a linear or branched alkyl or alkoxyalkyl radical having 3-5 carbon atoms and X.sup.- represents the radical of a strong acid or of a zinc chloride double salt, and a process for their preparation by diazotizing a 4,4'-diamino-3,3'-dialkoxybiphenyl of the formula (2) ##STR2## in which R has the meaning mentioned, in an aqueous, strong, non-oxidizing inorganic or organic acid at temperatures from about -10.degree. C. to about +40.degree. C. by means of an alkali metal nitrite, and precipitating the resulting bisdiazonium salts by adding an alkali metal chloride, bisulfate, monosulfonate of 1,5-naphthalenedisulfonic acid or tetrafluoroborate or zinc chloride. These salts are useful in dyeing and printing textile fiber materials by the methods of the ice color technique, using suitable coupling components; they are also useful for preparing photographic tracings by the methods of reprography.

Bisdiazonium salts of 4,4'-diamino-3,3'-dialkoxybiphenyls and a process

Using the method of azoic dyeing, fast blue dyeings are obtained when the bis-diazotable diazo component used is a compound of the general formula (1) ##STR1## in which R is a straight-chain or branched alkyl group of 3 to 5 carbon atoms or a (C.sub.1 -C.sub.3)-alkoxy-(C.sub.2 -C.sub.4)-alkyl group having straight-chain and/or branched alkyl groups of in total 3 to 5 carbon atoms, and the coupling component used is a compound conforming to the general formula (2) ##STR2## in which Z stands for a hydrogen atom or a halogen atom or an alkoxy group of 1 to 4 carbon atoms and Aryl denotes a phenyl radical or a 1-naphthyl radical which can be substituted by 1, 2 or 3 substituents from the group consisting of halogen, nitro, alkyl of 1 to 4 carbon atoms and alkoxy of 1 to 4 carbon atoms, and the coupling reaction and dye formation on the fiber are carried out at a pH value between 4 and 10.

Process for preparing water-insoluble blue azo dyes on the fiber:

Acid nitro dyestuffs are prepared by treating aminonitrodiphenylaminesulfonic acids with an oxidizing agent in an aqueous medium, the oxidizing agent employed being a manganese-(VI) or manganese-(VII) compound and the reaction being carried out at a pH higher than 5 and at a temperature between 20.degree. and 100.degree. C. The dyestuffs thus obtainable dye even fresh full-grained chrome leather in full shades.

Process for the preparation of acid nitro dyestuffs

Acid nitrodyestuffs are prepared by treating aminonitrodiphenylaminesulfonic acids with an oxidizing agent in an aqueous medium, the oxidizing agent being hypochlorous acid or its alkali metal or alkaline earth metal salts and the reaction taking place at above pH 4 and at a temperature between 0.degree. and 100.degree. C. The dyestuffs thus obtainable dye even fresh full chrome grained leather in deep shades.

Process for preparing acid nitro dyestuffs for leather

Liquid compositions of nitro group-containing aniline compounds containing no sulfonic acid and/or carboxylic acid groups and having a melting point of below 140.degree. C., especially those suitable for use as diazo component in ice color dyeing, which contain 20 to 70% of this nitro-aniline, 5 to 80 weight % of a castor oil oxethylated with 25 to 60 mols of ethylene oxide, and 5 to 65 weight % of N-methyl-pyrrolidone as solvent. By simply mixing these components clear solutions are obtained which can be diazotized within a few seconds by means of an aqueous sodium nitrite solution and thus give diazonium salt solutions free from residue. These diazonium salt solutions can be used in simple manner and very advantageously as developing baths or liquors for producing water-insoluble azo dyestuffs on the fiber according to the ice color technique.

Compositions of nitro-anilines for producing azo dyes on fibers

Concentrated solutions of water-insoluble bis-acetoacetic acid-diphenylamides as coupling components; these solutions contain in addition to one or more of these coupling components water and sodium and/or potassium hydroxide and as aliphatic solvent one or more mono- or di- to hexa-ethyleneglycol monoalkyl ethers having lower alkyl radicals, and optionally ethyleneglycol, diethyleneglycol and/or propyleneglycol. The coupling components are contained in the solutions in a concentration of up to about 50% by weight without deteriorating the storage stability of the solutions. The solutions may be used for preparing water-insoluble azo dyestuffs on the fiber according to 'ice-color' dyeing. On pouring into water containing a small amount of sodium hydroxide they give immediately ready-to-use impregnation baths.

Concentrated solutions of water-insoluble coupling components

An anionic surfactant can be used for the preparation of aqueous dispersions of specific composition with a high degree of fineness of the particle sizes of primary aromatic amines free from carboxylic acid or sulfonic acid groups. Besides said aromatic amine and said anionic surfactant these aqueous dispersion contain as a dispersing agent a water-soluble condensation product containing one or several radicals of oxalkylated, hydroxy and/or carboxy group-containing aromatic compounds, which radicals are linked with one another by methylene bridges either directly or via radicals of aromatic compounds. The dispersions may further contain a polyhydric alcohol and optionally a high molecular weight polyglycol. The dispersions have a good viscosity behavior, a good stability in storage and are stable at temperatures of about -15.degree. to +50.degree. C. They can be readily and rapidly diazotized and yield residue-free diazonium salt solutions with low tendency to foam formation. The dispersion and the diazonium salt solutions produced therefrom can be readily used for the production of water-insoluble azo dyes on the fiber, for example in ice-color technique.

Aqueous dispersions of primary aromatic amines, their use for the

By the present invention there has been found an improved process for the production of water-insoluble azo dyestuffs on the fiber according to the methods of the ice color dyeing, in which the fiber material is at first impregnated with a coupling component in an alkaline medium and thereafter developed by treating it with a developing bath which contains the diazonium compound; the improvement is characterized in that the developing bath contains an alkali metal-tri- or -tetrapolyphosphate and the pH value of the developing bath is greater than 4.5 prior to the coupling and smaller than 9 after the same. As compared with known processes, the novel process has the advantage that in this case there are not used any heavy metal salts, such as chromium and zinc salts, which have an adverse effect on the waste waters, and that besides there are no precipitates of zinc phosphate even in the case of zinc ions being present in the dye baths. The dyeings obtained with the novel process are marked by a good color yield, a good evenness and favorable fastness properties.

Process for the production of water-insoluble azo dyestuffs on the fiber

o-Aminophenol ethers deriving from lower alkylene glycols, lower alkylene polyglycols and the corresponding mono-lower alkyl ethers which may be substituted in the phenyl nucleus by halogen or nitro, are useful as diazo components in the 'all-in' printing process for preparing developing dyes on cellulose. In this process the printing paste contains the alkaline solution of the coupling component, a dispersion of the amine, sodium nitrite and a thickening composition and developing of the dye is brought about with acidic means, followed by or combined with a heat treatment.

Process for printing with developing dyes which employs having ether

An improved process for the preparation of water-insoluble azo dyestuffs on vegetable fibers according to the method of the ice-color technique had been found, impregnating first the fibrous material with an azo component and then developing it with a diazo solution of an aromatic amino compound in the neutral or slightly alkaline range, wherein an alkali metal borate is used to neutralize the diazo solution. The dyeings prepared in this improved dyeing process for ice color dyeing have very good fastness properties and are obtained with high color yields. The improvement of the dyeing process is seen in the use of alkali metal borate as a neutralizing agent, which avoids the creation of foam in the surfactant-containing diazo solution.

Cellulosic material is printed with a paste containing the alkaline solution of a coupler, the dispersion of a diazotable aromatic amine, a nitrite and a thickener and the dyestuff is developed on the fiber by acidic steaming or by adding solutions of organic acids and steaming or drying.

Process for the printing with developing dyes

It had been found that boric acid can advantageously be used as a buffer and neutralization agent in the developing bath containing the azonium compound in a process for the preparation of water-insoluble azo dyestuffs on the fiber according to the ice-color technique, thus avoiding ecological problems with regard to the waste water obtained in the dyeing process.

Highly concentrated solutions of coupling components of the ice-color dyeing technique had been found which possess a very good stability to storage and can readily be used for the preparation of diluted aqueous bottoming baths of the ice-color technique; these novel solutions contain the coupling component, water, sodium-or potassium hydroxide, and are characterized by the imperative content of diethylene-glycol or a content of a mixture of diethylene-glycol and ethylene-glycol or propylene-glycol or both.

Concentrated stable solutions of coupling components for the ice color

New improved dyeing preparations (formulations) have been found for preparing water-soluble azo dyestuffs on fiber according to ice-color dyeing which contain a diazonium or tetrazonium compound of an aromatic mono- or diamine having a pKa-value of more than 2.5 as well as boric acid instead of the usual aluminum sulfate or chromium (III)-acetate. These new dyeing compositions have the same good properties as comparable known dyeing preparations but avoid the severe disadvantages of the known preparations in respect to requirements in industrial medicine and ecology.

Dyeing preparations containing boric acid for preparing water-insoluble

Aqueous dispersions of primary aromatic amines which contain at least 30 per cent by weight of a primary aromatic amine, a water-soluble condensation product which contains 2 to 6 radicals of oxalkylated aromatic compounds carrying hydroxy or carboxy groups, these radicals being linked to each other over methylene groups either directly or via radicals of aromatic compounds, and containing water and, optionally, a polyvalent alcohol. These dispersions are very stable and storable for a very long period, the primary aromatic amines therein are so finely dispersed that they do not precipitate; they have a low viscosity and can easily be introduced with stirring in a dyeing liquor or in pastes. These novel dispersions are suitable for the preparation of water-insoluble azo dyestuffs according to the methods of ice-color technique by mixing them with a sodium nitrite solution and a hydrochloric acid solution for diazotization thereafter, the diazo compounds obtained may be used in known and usual manner for the preparation of the dyestuffs.

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Muhlheim, Germany

Hasso Hertel