IMPROVED PROCESSES FOR THE MANUFACTURE OF YELLOW, RED, AND VIOLET COLOURING MATTER
Year: 1879

page_text: PROVISIONAL SPECIFICATION left by William Robert Lake at the Office
of the Commissioners of Patents on the 8th December 1879. A communication
from abroad by Rudolf Krügner, of Elberfield, in the Empire of Germany.
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, & Co., Patent Agents,
Southampton Buildings, London. "IMPROVED PROCESSES FOR THE MANUFACTURE
OF YELLOW, RED, AND VIOLET COLOURING MATTER." A communication from
abroad by Rudolf Krügner, of Elberfeld, in the Empire of Germany.
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This Invention relates to a new process for the production of yellow, red, and
violet coloring or dyeing materials by the reaction of the diazo-combinations of
amido-azo-benzole C, H, N=N.-C. H. (NH)) and of its homologues as well as
by the reaction of the disulpho-acids of these bodies upon naphtoles (C₁, H, O),
dioxy-naphtalines (C, H, O₂), phenol (C, H, O) and mono-and-disulpho-acids.
The said process has for its object the production of pigments the color or shade
of which is purer and clearer, and the coloring power greater than those of the
naphtol colors produced heretofore.
To produce, for instance, in accordance with this process, a red pigment which is
nearly equal in color to cochineal, and which I term ponceau 3 R, I proceed as
follows, that is to say:-To 230 kilogrammes of Nordhausen sulphuric acid containing
14% of anhydrite I add (constantly cooling the vessel) 50 kilogrammes of sulphate
of amido-azo-benzole (C₁₂ H₁, N,) 2 H, SO,, or 47 kilogramines of the hydro-chlorate,
then I heat the mixture in the water bath gradually to a temperature of from 60° to
70° Celsius until a sample will dissolve clearly in water. It will be seen by this
experiment that the disulpho-acid of the amido-azo-benzole (C₁₂ H, N, (SO, H) 2)
has been formed. The above described process I will herein call, for convenience of
description, "sulphuring."
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This experiment being made I dilute with water and neutralize with caustic soda
(hydrate of soda), and I add as much water as will be necessary to keep the whole
in solution while getting cool.
To this solution of the combination of hydrate of soda with the disulpho-acid of
the amido-azo-benzole I add 50 kilogrammes of muriatic acid of 30%, cooling the
mixture considerably (3° to 5° Celsius); then I add gradually the calculated
quantity of 14 kilogrammes of nitrite of soda (Na NO.) of 100%, this quantity
dissolved in from 2 to 3 parts of water cooling constantly. It is by this action that
the disulpho-acid of the diazo-azo-benzole is formed. This process or treatment I
will call, for convenience of description, "diazoting."
On the other hand I dissolve 29 kilogrammes of ẞ naphtol with 16 kilogrammes
of hydrate of soda or caustic soda (100%) in as much water as will be necessary to

page_text: keep the whole in solution while cooling; then I allow it to cool to 3° or 5° Celsius
and add slowly (while agitating) the above described solution of the disulpho-acid
of the diazo-benzole.
The mixture is to be kept always in an alkaline state to the end of the reaction.
The pigment forms immediately; the greater part of it precipitates, and the
remainder must be separated by addition of chloride of sodium, then filtered and
purined by re-dissolving.
The homologues of the amido-azo-benzole, such as-
Amido-azo-toluol (C, H,-N-N-C, H₂ (NH)>, and
purined by re-dissolving.
The homologues of the amido-azo-benzole, such as-
Amido-azo-toluol (C, H,-N-N-C, H, (NH)), and
Amido-azo-xylol (Cg H,-N=N— Cg Hg (NH₂) ).
As well as
Methylamido-azo-benzole = (C, H, (C H₁)—N=N-C H₁ (NH2))
Methylamido-azo-toluol=(C, H, (CH)-N-N-C, H, (NH.))
Methylamido-azo-xylol= (C, H,, (C H)-N-N-C, H. (NH))
Aethylamido-azo-benzole (C, H, (C. H)-N-N-C, H, (NH,))
Aethylamido-azo-toluol-(C, H, (C. H)-N-N-C, H, (NH,))
Aethylamido-azo-xylol=(C, H, (C, H)-N-N-C, H. (NH))
=
when "sulphured" and "diazoted" according as herein before described, and then
brought together with 3 naphtol-natron produce also very brilliant orange-red and
red pigments.
The naphtol may be replaced by a naphtol phenol or by dioxy-naphtaline.
The amido-azo-naphtaline gives also by a treatment similar to that above
described, with ẞ and a naphtol, as well as with phenol and dioxy-naphtaline, a
very brilliant red pigment.
The hydrochlorate of amido-azo-benzol or its above mentioned homologues, also
the amido-azo-naphtaline when "diazoted" with nitrite of soda and hydrochloric
acid give in combination with the mono-and disulpho-acids of the naphtols dioxy-
naphtalines and phenol coloring or dyeing matters which vary in their color or
shade from red to violet, and are remarkable as powerful dyes.
Furthermore, I produce also the following mixed amido-azo-combinations, which
must be considered as completely new-

page_text: "diazoted" with nitrite of soda and hydrochloric acid give diazo-azo-combinations
which produce with the naphtoles dioxy-naphtalines and phenol yellow, red, violet,
and blue-violet colors or pigments.
The above mentioned mixed amido-azo-combinations when "diazoted" with
nitrite of soda and hydrochloric acid give in combination with the mono-and
disulpho-acids of the naphtoles dioxy-naphtalines and the phenol, also colors which
in their shade are more red and more blue than those above mentioned.
The advantages resulting from the use of this Invention are as follows,
namely
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The pigments produce a clearer and purer dyeing effect than the naphtol colours
heretofore used; their resistance to the action of air and soap is greater; they
possess a considerably greater strength for dyeing purposes than the colors of the
same kind heretofore produced, and the cost of production is comparatively low.