Patent GB-585874-A (GB)
Title: Manufacture of vat dyestuffs
IPC: C09B6/00
Filed: 1944-06-19
Abstract: Vat dyestuffs are prepared by treating an anthraquinone dicarboxylic acid of which the carboxyl groups are not in ortho-position to one another and at least one is in b -position, or a reactive derivative of such an acid with an amine containing a residue consisting of at least three carbocyclic rings, or with two different amines of which at least one contains a residue as aforesaid, the amine or amines being used substantially in such proportions that one amino group is present for each carboxyl group of the dicarboxylic acid.  The carboxyl groups may be attached to the same ring, but are preferably attached to different rings, both in the b -position such as the 2 : 6-or 2 : 7-positions.  It is preferred that the a -position in the dicarboxylic acid should be occupied by an amino group, but it may be occupied by halogen atoms or alkoxy, nitro or amino groups, and these groups converted to amino groups in the finished dyestuffs. The anthraquinone dicarboxylic acid may have additional rings attached to the anthraquinone ring such as acridone, thioxanthone or pyridine rings.  Anthraquinone dicarboxylic acids mentioned include the 2 : 4-, 2 : 6- and 2 : 7-acids, the 1 : 5-dihalogen-2 : 6-acid, 1-amino-2 : 4-acid, 1 : 5-dinitro-, 1 : 5-dialkoxy-, or diamino-2 : 6 - acids. Acids containing further substituents may also be used such as halogen acylamino or alkoxy in the 4 and/or 8 positions, as well as 1 : 8-dinitro-, and 1 : 8-diamino-2 : 7-acid, and the 1-amino-2 : 4-acid.  The acids are preferably used in the form of their reactive functional derivatives such as their acid chlorides.  The carbocyclic rings of the amine component may be purely aromatic in character, or they may contain in addition heterocyclic rings.  The preferred amines are those which are themselves coloured or which possess fluorescent properties, and which are capable of being vatted, such as an anthraquinone or more highly condensed ring system. Anthraquinone amines mentioned include 1-amino-and 2-amino-anthraquinones which may contain additional substituents such as halogen atoms, and methoxy, arylamino and acylamino groups.  Among the amino compounds containing more highly condensed ring systems, there are mentioned aminodibenzanthrones, aminoisodibenzanthrones, aminopyranthrones, aminoanthrapyrimidines, aminoanthrapyridones and aminoanthraquinoneacridones.  A preferred class of amino compounds are those capable of being vatted which contain in ortho position to the amino group a substituent capable of leading to the formation of a heterocyclic ring such as a hydroxyl, mercapto, nitro or amino group, or a halogen atom.  In the case of a hydroxyl mercapto or amino group, the conditions of the main reaction are such as to induce ring formation.  In other cases, a further operation is necessary.  The products so obtained have an azole ring of the structure: <PICT:0585874/IV/1> The reaction of the dicarboxylic acid with the amine is preferably carried out in an inert dispersing agent or solvent such as mono-, di-, or trichlorobenzene, or nitrobenzene. The presence of acid binding agents such as tertiary bases is desirable.  The Specification contains a very large number of examples illustrating different combinations of anthraquinone dicarboxylic acids and amines falling within the definitions given above to produce vat dyestuffs which can be used in known manner for dyeing and printing animal and vegetable fibres such as wool, silk, leather, cotton, linen, rayon, staple fibre of regenerated cellulose and mixtures of such fibres.  Specifications 339,396, [Class 2 (iii)], and 488,642 are referred to.