Manufacture of Safranine Azo Dyestuffs Soluble in Water.
Year: 1896

page_text: Date of Application, 6th Mar., 1896
Complete Specification Left, 3rd Dec., 1896-Accepted, 9th Jan., 1897
[Communicated from abroad by THE FARBWERKE, vormals MEISTER LUCIUS
AND BRUNING, of Hoechst a/ Main, in the Empire of Germany, Chemical
Manufacturers.]
Manufacture of Safranine Azo Dyestuffs Soluble in Water.
I, OLIVER IMRAY, of No. 28 Southampton Buildings, Chancery Lane, in the
County of London, Chartered Patent Agent, do hereby declare the nature of this
invention to be as follows:-
It is known that the diazo compounds of safranines may be combined with a and
B-naphthols and their sulphonic acids thus forming dyestuffs. But the dyestuffs
thus obtained have never been of any practical value, partly on account of their
few prominent properties, and partly on account of their being insoluble in water,
and consequently useless for dyeing or printing purposes.
The latter is chiefly the case with diazotised safranines and compounds of the
two naphthols.
The B-naphthol dyestuff, in particular, has been for some years repeatedly the
subject of researches with a view to render the beautiful indigo blue coloured body
serviceable, in some way or other, for dyeing purposes.
Thus the preparation of dyestuffs on the fibre was first attempted by dyeing or
printing material prepared with naphthol alkali by means of an acetic acid solution
of diazo safranine (Agenda du Chimiste 1890 page 518).
This treatment, however, was practically of little importance; other methods,
having for their object the transformation of the originally insoluble dyestuff into
a soluble form, suitable for dyeing purposes, attained better results by various
treatments; but hitherto no satisfactory method for the transformation of the
insoluble into a soluble form has been given.
My foreign correspondents have succeeded in establishing the surprising fact
that by letting diazo safranines act upon B-naphthol in presence of ammonia,
dyestuffs may be obtained, which, without previous treatment with diluted acids or
water, are easily soluble in cold and warm water and may be used with great
advantage for dyeing and printing purposes.
To manufacture the new dyestuffs, they proceed in the following manner :-
7 kilos. of safranine T (from toluylene-diamine, o-toluidine, y aniline) are
dissolved in 500 litres of water; to the solution are added 54 litres of hydrochloric
acid of 28-7 per cent. strength, and the whole is then diazotised with a solution of
1-6 kilos. of nitrite. On completion of the diazotation the solution is run into a
vessel, provided with an agitator, which contains 200 litres of water, 8 kilos.
ammonia of 20 per cent. strength and 2-9 kilos. of B-naphthol.
When the materials are thoroughly mixed, the agitation is continued for about
two hours, and 50 litres of a saturated solution of salt are added, the precipitated
dyestuff being then collected in a filter press. The filtrate still contains free
ammonia. The dyestuff is pressed and either dried at a gentle heat or made into
paste. It is easily soluble, as already mentioned, in cold and warm water with a
bluish violet colour and it dyes unmordanted or mordanted cotton in indigo
blue tints.

page_text: Instead of safranine T, the equivalent quantity of pheno safranine or tolu
safranine may be employed in the process above described.
Dated this 6th day of March 1806
ABEL & IMRAY,
Agents for the Applicant.
Manufacture of Safranine Azo Dyestuffs Soluble in Water.
I, OLIVER IMRAY, of No. 28 Southampton Buildings, Chancery Lane, in the
County of London, Chartered Patent Agent, do hereby declare the nature of this
invention and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement :--
It is known that the diazo compounds of safranines may be combined with a and
B-naphthols and their sulphonic acids thus forming dyestuffs. But the dyestuffs
thus obtained have never been of any practical value, partly on account of their
few prominent properties, and partly on account of their being insoluble in water,
and consequently useless for dyeing or printing purposes.
The latter is chiefly the case with diazotised safranines and compounds of the
two naphthols.
The B-naphthol dyestuff in particular, has been for some years repeatedly the
subject of researches with a view to render the beautiful indigo blue coloured body
serviceable, in some way or other, for dyeing purposes.
Thus the preparation of dyestuffs on the fibre was first attempted by dyeing or
printing material prepared with naphthol alkali by means of an acetic acid solution
of diazo safranine (Agenda du Chimiste 1890 page 518).
This treatment, however, was practically of little importance; other methods,
having for their object the transformation of the originally insoluble dyestuff into a
soluble form, suitable for dyeing purposes, attained better results by various
treatments, but hitherto no satisfactory method for the transformation of the
insoluble into a soluble form has been given.
My foreign correspondents have succeeded in establishing the surprising fact
that by letting diazo safranines act upon ẞ-naphthol in presence of ammonia,
dyestuffs may be obtained, which, without previous treatment with diluted acids or
water, are easily soluble in cold and warm water and may be used with great
advantage for dyeing and printing purposes.
The same effect is obtained, if, instead of combining diazosafranines with
6-naphthol in presence of ammonia, the dyestuffs insoluble in water obtained in
the usual manner from diazo safranines and B-naphthol in presence of fixed
alkalies, be treated with a solution of an ammonia salt (hydrochlorate of ammonia,
sulphate of ammonia etc.).
To manufacture the new dyestuffs, they proceed in the following manner:-
7 kilos. of safranine T (from toluylene-diamine o-toluidine y aniline) are dissolved
in 500 litres of water; to the solution are added 5 litres of hydrochloric acid
of 28.7 per cent., strength, and the whole is then diazotised with a solution of
1-6 kilos. of nitrite. On completion of the diazotation the solution is run into a
vessel, provided with an agitator, which contains 200 litres of water, 8 kilos.
ammonia of 20 per cent. strength and 2.9 kilos. of ẞ-naphthol.
When the materials are thoroughly mixed, the agitation is continued for about
two hours, and 50 litres of a saturated solution of salt are added, the precipitated
dyestuff being then collected in a filter press. The filtrate still contains free
ammonia. The dyestuff is pressed and either dried at a gentle heat or made into
paste. It is easily soluble, as already mentioned, in cold and warm water with a

page_text: bluish violet colour and it dyes unmordanted or mordanted cotton in indigo blue
tints.
Instead of safranine T, the equivalent quantity of pheno-safranine or tolu-
sufranine may be employed in the process above described.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. The manufacture of blue dyestuffs soluble in water by causing diazo
compounds of safranine dyestuffs to act upon ẞ-naphthol in the presence of
ammonia or by treating with an ammonia salt the insoluble products obtained by
the action of diazo compounds of the safranines upon ẞ-naphthol in the presence
of fixed alkalies, substantially as described.
2. The dyestuffs manufactured as above set forth.
ABEL & IMRAY,
Agents for the Applicant.