Improvements in the Manufacture of Colouring Matters.
Year: 1899

page_text: Date of Application, 28th Sept., 1899
Complete Specification Left, 26th June, 1900- Accepted, 28th July, 1900
[Communicated from abroad by FARBWERK MÜHLHEIM, formerly A. Leonhardt
& Co., of Mühlheim on the Maine in the Empire of Germany, Manu-
facturers.]
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:-
In the Specification of Letters Patent No. 248308 I have shown that certain
azodyes deriving from a-naphtylamine-8-sulphoacid when gently treated
with aromatic amines are converted into new dyestuffs of a more blueish tint.
I have since found that this new method is not confined to the azodyes referred
to in the said specification but can be applied to a large number of other dye-
stuffs produced from diazobodies and a-naphtylamine-S-sulphoacid. Such
primary dyestuffs are of little practical value because the shades obtained there-
with have a too reddish tint; but by treating such primary dyestuffs, say with
paratoluidine in a manner similar to that indicated in the said former patent, new
dyestuffs result some of which are of great importance for practical purposes.
Dated this 28th day of September 1899.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.
Improvements in the Manufacture of Colouring Matters.
I, HENRY HARRIS LAKE, of the Firm of Haseltine, Lake & Co., 45, Southampton
Buildings, in the County of Middlesex, 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:-
In the Specification of former Letters Patent No. 24830/98 I have shown that
certain azodyes derived from 1.8-diazonaphtholsuiphoacids and 1.8naphthylamine-
sulphoacid when gently treated with aromatic amines are converted into new
dyestuffs of a more bluish tint.
I have since found that this new method is not confined to the hydroxylated
azodyes referred to in the said specification but can be applied to a large number
of other dyestuffs produced from diazobodies and 1.8 naphthlyaminesulphoacid.
Such primary dyestuffs are of little practical value because the shades obtained
therewith have a too reddish tint; but by alphylating such primary dyestuffs in
.

page_text: a manner similar to that indicated in the said former patent, new dyestuffs
result some of which are of great importance for practical purposes.
In carrying this invention into practice the alphylation must also be a gentle one
and in this respect I refer to the general observations which I have made in the
Specification of my said former Patent. In the following example the parts
indicated are by weight:
One part of the dyestuff produced from paradiazobenzenesulphoacid and
1.8-naphthylaminesulphoacid (in a solution weakly acidulating with acetic acid)
is dissolved in ten parts of water, the solution is mixed with two parts of para-
toluidine and one half part of hydrochloric acid of 30%, and the mass is digested
while stirring at about 60° C., until a sample shows no further increase of the
reddish shade. This point will generally be reached after about two hours. The
mass is then diluted with about double the quantity of water and after acidifying
with hydrochloric acid and digesting for some time at a moderately elevated
temperature, the acid of the coloring matter, which is separated, is filtered,
dissolved in carbonate or acetate of soda solution and salted out. The dyestuff
thus obtained dyes wool in red shades. By employing instead of paradiazo-
benzenesulphoacid other diazocompounds, the mode of operation is essentially
the same. For instance, by employing diazotized naphthionic acid, a claret
coloured dyestuff is obtained; 1.4 nitronaphthylaminesulphoacids (sulphogroup in
the 6-, 7-, or 8-position) yield violet to blue shades. By employing, instead of para-
toluidine, aniline, the obtained dyestuffs are of a more yellowish or reddish shade.
Having now particularly described and ascertained the nature of this 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 hereindescribed process for the production of colouring matters, which
consists in gently treating with aniline or paratoluidine the colouring matters
derived from diazotized sulphanilic acid, naphthionic acid or 1.4-nitronaphthyl-
aminesulphoacid and 1.8 naphthylaminesulphoacid.
2. The dyestuffs produced according to the process referred in to Claim 1.
Dated this 25th day of June 1900.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.