Improvements in the Manufacture of Colouring Matters.
Year: 1898

page_text: Date of Application, 24th Nov., 1898
Complete Specification Left, 29th July, 1899-Accepted, 2nd Sept.,
1899
[Communicated from abroad by FARBWERKE MÜHLIIEIM, formerly A. Leonhardt
& Co., of Mühlheim, on the Main, in the Empire of Germany, Manufacturers.]
Improvements in the Manufacture of Colouring Matters.
I, HENRY HARRIS LAKE, of the Firm of Haseltine, Lake & Co., Patent Agents,
45, Southampton Buildings, in the County of Middlesex, do hereby declare the
nature of this invention to be as follows:-
The dyestuffs derived from 1.8 diazonaphtholsulpho-acids and a-naphthylamine-
8-sulphoacid have not as yet been described in literature. I have found that
they dye wool in reddish violet shades and therefore are of no great importance
for practical purposes. But I have further found that by treating such azo-dyes
with aromatic amines, new dyestuffs can be obtained of a more blue tint, which
are of high technical value regarding purity of shade and fastness to light or
washing.
Such treatment of the primary dyestuffs with aromatic amines must be a gentle
one and I wish it understood especially, that by heating the primary dyestuffs
in the usual way, say with paratoluidine and its chlorhydrate up to about 160° C.,
destruction takes place after a short time. Such destruction however can be
avoided by operating under different conditions, for instance, 10 kilos of the
primary dyestuff are heated at the reflux cooler together with 120 litres of spirit,
30 kilos of paratoluidine and 5 litres of concentrated hydrochloric acid. When
after some hours a sample of the solution when dyed on wool does not show a
further increase of bluishness of shade, the whole mass is acidified with hydro-
chloric acid and then diluted with water, whereby the acid of the new colouring
matter separates. It is then dissolved in water under the addition of acetate
of sodium and the colouring matter is precipitated by common salt.
Dated the 24th day of November 1898
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.
I, HENRY HARRIS LAKE, of the Firm of Haseltine, Lake & Co., Patent Agents,
45, Southampton Buildings, in the County of Middlesex, do hereby declare the
[Price 8d.1

page_text: 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: -
The dyestuffs derived from the combination of 18 diazo naphtholsulphoacids
with a-naphthylamine-8-sulphoacid have not as yet been described in the
literature. I have found that they dye wool in reddish violet shades which are
of no great value for practical dyeing purposes. But I have further found that
by treating those azodyes with aromatic amines under special conditions herein-
after specified dyestuffs can be obtained of a bluer tint, which are of high technical
value regarding purity of shade and fastness to light and washing.
Such treatment of the primary dyestuffs with aromatic amines must be a gentle
one and I wish it to be understood especially that by heating the primary dyestuffs
in the usual way say with paratoluidine and its hydrochlorate to temperatures
above 100° C. destruction takes place after a short time with the formation of red
products of decomposition. However by operating under less energetic conditions
it is possible to lead the reaction in another way so that the desired result is
obtained. I have ascertained the remarkable fact that a prolonged treatment of
the primary dyestuffs with aromatic amines in the cold is sufficient for that pur-
pose. Therefore, the yield of colouring matter is most favorable by employing
ordinary or moderately elevated temperatures because under such conditions
destruction is avoided as much as possible. It is further advisable to carry out
the reaction in the presence of a suitable diluent agent.
According to these general observations I proceed for instance as follows:
15 kilos of the dyestuff produced in the usual manner from 18 diazonaphthol-
35-disulphoacid and 18 naphthylaminesulphoacid in a solution weakly acidu-
lated with acetic acid are dissolved in about 60 litres of hot water. To this
solution whilst stirring 90 litres of spirit are added whereby the dyestuff is again
precipitated in a voluminous form.
To the mass thus obtained 48 kilos of paratoluidine and 75 litres of hydro-
chloric acid of 20° Bé. are added whilst stirring and the whole mass is then
allowed to stand for about 12 days at the ordinary temperature until a sample
worked up as described below, shows that the reaction is finished. The mass is mixed
with ice acidulated with hydrochloric caid diluted with about 500 litres of water
and the acid of the colouring matter is filtered off. The filtrate should not contain
much unchanged primary colouring matter. The acid colouring matter is then
dissolved in 250 litres of water and about 5.5 kilos of acetate of sodium and the
obtained blue solution is salted out.
By treating with paratoluidine not at the ordinary temperature but at about
60° C., the reaction is finished in about 6 hours.
According to my experience also in this case some acid (7.5 litres of hydrochloric
acid in the example) must be present in carrying out the process. Hydrochloric
acid has given the best result.
By employing aniline instead of paratoluidine the raction requires a longer
time and the obtained dyestuffs are of a redder shade.
By employing instead of 1.8 diazo-naphthol-3-5-disulphoacid, isomeric acids,
for instance, 18 diazo-naphthol-3-6,-4 6- or 47-disulphoacid, the result will be an
analogous one. By employing the 36 acid, the reaction requires a longer time
and by employing the 46 acid, it requires a shorter time than with the 35 acid
of the example. The diazonaphthol monosulphoacids are less suitable for the
present purpose.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, as communicated to
me by my foreign correspondents, I declare that what I claim is:-
1. The herindescribed process for the production of blue colouring matters
which process consists in gently treating with aniline or paratoluiding the colour-
ing matters derived from 18 diazonaphthol 35, 36, 46 or 47 disulphoacid and
18 naphthylaminesulphoacid, substantially as described.

page_text: 2. The dyestuffs produced according to the process referred to in Claim 1.
Th 00th low of Lul 1800
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.