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US4468349A Expired / Lapsed US ⏱️ 0.0 years remaining

Process for the preparation of solutions of cationic azo dyestuffs

Assignee: Bayer AG
•
Filing: 1981-07-30
•
Granted: 1984-08-28
•
Expires: 2001-07-30
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Abstract

Abstract Concentrated stable solutions of cationic azo dyestuffs of the formula ##STR1## wherein A denotes the radical of an aromatic-carbocyclic or aromatic-heterocyclic diazo component, R denotes alkylene, R 1 denotes hydrogen or alkyl, R 2 denotes alkyl, alkenyl or aralkyl, R 3 denotes alkyl, R 4 denotes hydroxyalkyl with 2 or more C atoms, R 5 denotes halogen, alkyl, alkoxy, aryloxy, acyl or acylamino, m denotes 0, 1, 2, 3 or 4 and An .sup.(-) denotes a carboxylate ion, and wherein the cyclic and acyclic substituents can carry further non-ionic substituents, which solutions have a low salt content, are prepared by simultaneously reacting amines of the formula A--NH.sub.2 (II) coupling components of the formula ##STR2## and alkali metal nitrites or alkaline earth metal nitrites in aqueous carboxylic acids and, if appropriate, organic water-soluble solvents, and then separating off the alkali metal sulphates or alkaline earth metal sulphates which thereby crystallize out.

Inventors

  • 👤 Karl Linhart
  • 👤 Harald Gleinig
  • 👤 Gunther Boehmke
  • 👤 Kurt Breig

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-07 14:51
CPC Classifications
C; C09; C09B; C09B44/00; C09B44/02; C09B44/04; C09B41/00; C09B41/006; C09B41/009; C09B67/00; C09B67/0071; C09B67/0075; C09B67/0076

Claims Analysis

Total Claims: 7
Claim 1
Independent Claim 148 words
In the preparation of concentrated stable solutions of cationic azo dyestuffs of the formula ##STR16## wherein A denotes the radical of an aromatic-carbocyclic or aromatic-heterocyclic diazo component, R denotes alkylene, R 1 denotes hydrogen or alkyl, R 2 denotes alkyl, alkenyl or aralkyl, R 3 denotes alkyl, R 4 denotes hydroxyalkyl with 2 or more C atoms, R 5 denotes halogen, alkyl, alkoxy, aryloxy, acyl or acylamino, m denotes 0, 1, 2, 3 or 4 and An.sup.(-) denotes a carboxylate ion, and wherein the cyclic and acyclic substituents can carry further non-ionic substituents, which solutions have a low salt content, by coupling, the improvement which comprises simultaneously reacting amines of the formula A--NH.sub.2 coupling components of the formula ##STR17## and alkali metal nitrites or alkaline earth metal nitrites in aqueous carboxylic acids, and separating off the alkali metal sulphates or alkaline earth metal sulphates which thereby crystallize out.
Claim 2
Dependent Claim 148 words
In the preparation of concentrated stable solutions of cationic azo dyestuffs of the formula ##STR16## wherein A denotes the radical of an aromatic-carbocyclic or aromatic-heterocyclic diazo component, R denotes alkylene, R 1 denotes hydrogen or alkyl, R 2 denotes alkyl, alkenyl or aralkyl, R 3 denotes alkyl, R 4 denotes hydroxyalkyl with 2 or more C atoms, R 5 denotes halogen, alkyl, alkoxy, aryloxy, acyl or acylamino, m denotes 0, 1, 2, 3 or 4 and An.sup.(-) denotes a carboxylate ion, and wherein the cyclic and acyclic substituents can carry further non-ionic substituents, which solutions have a low salt content, by coupling, the improvement which comprises simultaneously reacting amines of the formula A--NH.sub.2 coupling components of the formula ##STR17## and alkali metal nitrites or alkaline earth metal nitrites in aqueous carboxylic acids, and separating off the alkali metal sulphates or alkaline earth metal sulphates which thereby crystallize out.
Claim 3
Dependent Claim 40 words
Process according to claim 1, wherein solutions which contain 10-60% by weight of the cationic dyestuff, 10-80% by weight of the water-soluble carboxylic acid, 2-20% by weight of the water-soluble organic solvent and 3-30% by weight of water are prepared.
Claim 4
Dependent Claim 13 words
Process according to claim 1, wherein the reactants are employed in equimolar amounts.
Claim 5
Dependent Claim 14 words
Process according to claim 1, wherein acetic acid is used as the carboxylic acid.
Claim 6
Dependent Claim 16 words
Process according to claim 1, wherein the aqueous carboxylic acid further contains an organic water-soluble solvent.
Claim 7
Dependent Claim 15 words
Process according to claim 5, wherein the organic water-soluble solvent is ethylene glycol or caprolactam.

References Cited (Backward Citations)

US2478767A Cited
DE1162665B Cited
FR1355911A Cited
DE1644323A1 Cited
FR1578454A Cited
US3941768A Cited
US3793305A Cited
US4058517A Cited
FR2219204A1 Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1987-08-28 1988-02-27 1988-08-28 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1991-08-28 1992-02-27 1992-08-28 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1995-08-28 1996-02-27 1996-08-28 $7700.00 Window Closed / Lapsed

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