Improvements in the Manufacture of Red Colouring Matters Suitable for Dyeing and Printing.
Year: 1889

page_text: Date of Application, 20th Feb., 1889
Complete Specification Left, 14th Nov., 1889-Accepted, 18th Jan., 1890
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Red Colouring Matters Suitable
for Dyeing and Printing.
I, IVAN LEVINSTEIN of Minshull Street Manchester in the County of Lancaster,
Manufacturing Chemist, do hereby declare the nature of this invention to be as
follows:-
This Invention relates to red colouring matters suitable for dyeing and printing,
and these Improvements consist in the production of certain new red colouring matters
by first preparing from Metaxylidin, à base which may be called Thiometaxylidin;
second by azotising this base; third by combining the diazo compounds of Thiome-
taxylidin with phenols or with the sulpho acids of phenols. Or, instead of combining
the Thiometaxylidin with phenols or their sulpho acids, I may first convert the
Thiometaxylidin into a sulpho acid and then combine the diazo compound of the
sulpho acid of Thiometaxylidin with phenols or their sulpho acids.
PREPARATION OF THE THỊOMETAXYLIDIN.
I heat 121 parts by weight of pure metaxylidin with 32 parts by weight of sulphur
for from about one to three hours at a temperature varying from about 170 to 240
degrees Centigrade, after which the larger portion of the metaxylidin will have
changed into Thiometaxylidin.
This Thiometaxylidin may then be purified, and I have found the following method of
purification to give satisfactory results. The Thiometaxylidin is dissolved in hot and
diluted sulphuric acid, consisting of about one part of concentrated sulphuric acid
and two parts of water. The solution is then filtered and diluted by the addition of
water, when the sulphate of Thiometaxylidin will be precipitated from its solution. If
it is desirable to obtain the Thiometaxylidin in a state of absolute purity, this process
of purification may be repeated several times. The sulphate of Thiometaxylidin thus
obtained may then be converted into its diazo compound. For this purpose, I have found
it preferable not to dry the sulphate, but to take it in the form of paste and bring it
into a state of finely divided suspension in water to which there is then added the
theoretical quantity of Nitrite of Sodium or its equivalent, or a quantity sufficient to
convert the sulphate of Thiometaxylidin into its diazo compound, in a manner which is
well understood by chemists. The diazo compound of Thiometaxylidin is then
combined for example with an alkaline solution of the alpha-monosulpho-acid of beta-
Naphthol in the calculated theoretical quantity and in the manner well understood by
chemists. The result is a bright red colouring matter.
PRETA
RELANATION 01 THE SULTING HOME OF TH
The herein before described purified sulphate of Thiometaxylidin is washed with water
in order to get rid of free sulphuric acid, pressed, dried at a moderate temperature,
and then added carefully to about four times its weight of tuming sulphuric acid
RELATATION
The herein before described purified sulphate of Thiometaxylidin is washed with water
in order to get rid of free sulphuric acid, pressed, dried at a moderate temperature,
and then added carefully to about four times its weight of tuming sulphuric acid
containing about fifteen to thirty per cent. of anhydrous acid. The mixture is then
heated on a water bath for about one hour or until a sample taken from the solution,
when diluted and washed, will dissolve in an alkaline solution, as for example in a
solution of carbonate of soda. The whole mixture is then cautiously poured into
water, and the sulpho acid of Thiometaxylidin, which is insoluble in water, is separated
by filtration or by other suitable means.
In order to further purify the sulpho acid of Thiometaxylidin thus obtained, it may
be dissolved in a solution of carbonate of soda, when its sodium salt may be precipitated

page_text: by the addition of common salt. This sodium salt of the sulpho acid of the Thiome-
taxylidin may then be converted into its diazo compound in a well known manner and
may then be combined for example with an alkaline solution of beta-Naphthol, also in
a well known manner. The colouring matter resulting from this combination is a
bright red.
The colouring matters obtained from the combination of Thiometaxylidin with the
sulpho acids of alpha or of beta-Naphthol, or those obtained by combining the sulpho
acid of Thiometaxylidin with alpha or with beta-Naphthol, or with the sulpho acids
of either of the two Naphthols, are all colouring matters in which red predominates;
their value can not however be differentiated as this will depend to a large extent
upon the purpose for which they are used, and also upon the caprices of fashion.
As some of the colours are soluble in water with more or less difficulty, it is
preferred to convert those which are less soluble into their sulphate compounds by
treating them hot with a solution of bisulphite of soda in a well known manner.
The
colouring matters are thus obtained in a more soluble form and in a more suitable
state for colouring certain materials. The sulphites are yellow to orange red colouring
matters which however when used for dyeing purposes change into reds after the
dyed goods are passed through alkaline solutions.
Other processes than that herein before described may be employed for the purification
of the Thiometaxylidin. Also, instead of converting the sulphate of Thiometaxylidin
into its diazo compounds, other salts of this base may be used as for example, the
hydrochlorate of Thiometaxylidin, and instead of sulphonating the sulphate of Thiome-
taxylidin, other of its salts or the base itself may be sulphonated while observing special
precautions; but so far as my present knowledge and experience enables me to determine,
I prefer to use in all these cases the sulphate of Thiometaxylidin.
I desire it to be understood that the herein before specified proportions of Metaxy-
lidin and of sulphur and also that the temperature and duration of their treatment
may be varied further, that in sulphonating the Thiometaxylidin, the proportions,
strength of sulphuric acid, period of treatment and other terms may be varied, but
according to my present knowledge and experience I prefer to proceed as hereinbefore
set forth.
Dated this 19th day of Februan Å D 1000
WILLIAM E. HEYS,
Agent for the Applicant.
COMPLETE SPECIFICATION.
Improvements in the Manufacture of Red Colouring Matters Suitable
for Dyeing and Printing.
I, IVAN LEVINSTEIN of Minshull Street Manchester in the County of Lancaster,
Manufacturing Chemist, 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 :-
This Invention relates to red colouring matters suitable for dyeing and printing,
and these Improvements consist in the production from metaxylidine of certain new
colouring matters in which red predominates.
In proceeding according to this Invention, I first prepare from pure Metaxylidine
(1. 3. 4.) a new sulphur base which I call Thionietaxylidine; the next step is to azotise
the new Thio-base, and the third to combine the diazo compound with phenols or their
sulpho-acids. Or, instead of combining the thio-base with phenols or their sulpho-
acids, I may first convert the Thiometaxylidine into a sulpho-acid which may then be
azotised and the diazo compound of the sulpho-acid of Thiometaxylidine combined
with phenols, or with their sulpho-acids. The combinations of the Thiometaxylidine
with phenols produce colouring matters which are insoluble in water, and in order to
obtain these combinations in a soluble form they may be converted into sulpho-
compounds in a manner and by means well known to chemists.

page_text: PREPARATION OF THIOMETAXYLIDINE, A SULPHUR COMPOUND OF METAXYLIDIne.
121 parts by weight of metazylidine (1. 3. 4.) are heated with 32 parts by weight
of sulphur for about from one to three hours at a temperature varying from about
170 degrees to 240 degrees Centigrade, when the larger portion of the metaxylidine
will be changed into Thiometaxylidine. This product may then be purified in the
following manner :-The substance is dissolved in diluted sulphuric acid (about one
part of ordinary concentrated sulphuric acid to about two parts of water). The
solution is then filtered and further diluted with water, when the sulphate of the new
Thio-base will be precipitated from its solution. Should it be desired to obtain the base
in a state of still further purity, the process of purification may be repeated as often
as may be required.
The new base obtained as herein before described may be converted into its azo-
compound by taking it, (preferably in the form of paste) suspending it in water, and
adding Nitrite of Soda or its equivalent in the calculated molecular proportions; for
example, one molecule of Nitrite of Soda to one molecule of Base, or two molecules
of the Nitrite to one molecule of the Base.
The diazo-compound thus produced may be combined with a phenol sulpho-acid as
for example with an alkaline solution of the alpha-mono-sulpho-acid of beta-Naphthol
in the calculated quantity, i.e. one molecule of the alpha-mono-sulpho acid to one
molecule of the diazo-compound. The product is a colouring matter which dyes
unmordanted cotton a bright red.
PREPARATION OF THE SULPHO-ACID OF THIOMETAXYLIDINE.
The sulphate of Thiometaxylidine prepared and purified as herein before described is
washed with water in order to get rid of any free sulphuric acid, pressed, dried at a
moderate temperature, and then carefully added to about four times its weight of
fuming sulphuric acid containing about fifteen to thirty per cent. of anhydrous acid.
The mixture is then heated on a water bath for about one hour or until a sample when
washed will dissolve in an alkaline solution of Carbonate of Soda. The mixture is
then gradually and cautiously poured into water when the new sulpho-acid of
Thio.netaxylidine will be precipitated and may be separated by filtration or otherwise.
If it is desired to still further purify the sulpho-acid it may be dissolved in a solution
of Carbonate of Soda and the sodium salt thus produced may be precipitated from its
solution by means of ordinary common salt. This sodium salt of the sulpho-acid of
Thiometaxylidine may be converted into its diazo-compound by treatment with the
calculated quantities of Nitrite of Soda, for example, one molecule of the Base to one
molecule of the Nitrite, and it may then be combined with, for example, an alkaline
solution of one molecule of beta-Naphthol. The colouring matter resulting from this
combination is a bright red.
Red predominates in all the colouring matters which are obtained from the
combinations of Thiometaxylidine with the sulpho-acids of Phenols or from the com-
binations of the sulpho-acid of Thiometaxylidine with Phenols or the sulpho-acids of
Phenols. Their values can not however be differentiated as they depend upon the
purposes for which they are used and upon the caprices of fashion.
As some of the colouring matters produced as hereinbefore described are soluble in
water with more or less difficulty, those which are less soluble may be converted into
sulphites by heating them in the form of a paste with an excess of Bisulphite of Soda
for several hours or until the colouring matter becomes quite soluble.
The sulphites are yellow to red colouring matters but when the materials dyed or
coloured therewith are passed through or treated with an alkaline solution, the colours
change to reds.
I may employ other processes than that hereinbefore described for the purification
of the new sulphur base Thiometaxylidine, and instead of using the sulphate for

page_text: conversion into the diazo compound I may use other salts as for example the hydro-
chlorate.; also, instead of sulphonating the sulphate, other salts of Thiometaxylidine
or the base itself may be sulphonated under the necessary and known precautions..
In like manner I may vary the proportions of Metaxylidine (1. 3. 4.) and of sulphur
and the temperature and duration of their treatment during the production of the
Thiometaxylidine; also, in sulphonating the Thiometaxylidine or its salts, the propor-
tions, the strength of the sulphuric acid, and the duration of the treatment may be varied
from those hereinbefore set forth but so far as my present knowledge and experience
permit me to judge, the proportions, materials, strengths, temperatures and durations
hereinbefore described are those.found to be most suitable and I therefore at present
prefer to employ them without necessarily limiting myself to them.
Having now particularly described and ascertained the nature of my said Inven-
tion and in what manner the same is to be perfornied, I declare that what I
claim is
(1) A new sulphur compound which may be called Thiometaxylidine and which is
prepared by treating a mixture of metaxylidine (1. 3. 4.) and sulphur at an elevated
temperature, substantially as herein before described.
(2) The production of Thiometaxylidine by the herein before described process
which consists in the treatment of a mixture of metaxylidine (1. 3. 4.) and sulphur at
an elevated temperature, substantially as set forth.
(3) The Diazo compound of Thiometaxylidine produced by treating a salt of Thiome-
taxylidine with an azotising material such as nitrite of soda, substantially as
hereinbefore described.
(4) Colouring matters in which red predominates produced by treating the diazo
compound of Thiometaxylidine with phenols or with the sulpho-acids or phenols,
substantially as herein before described.
(5) A sulpho acid of Thiometaxylidine produced by treating Thiometaxylidine or
suitable salts of Thiometaxylidine with sulphuric acid, substantially as hereinbefore
described.
(6) Colouring matters (which change to red when the material dyed therewith is
passed through an alkaline solution) produced by converting the colouring matters
referred to in the 4th claiming clause into sulphites; substantially as described.
(7) The production of colouring matters by the combination of Thiometaxylidine or
of its salts with phenols and with the sulpho-acids of phenols substantially as herein-
before described.
(8) Colouring matters produced by the combination of the sulpho-acids of Thiome-
taxylidine with phenols and with the sulpho-acids of phenols; substantially as
herein before described.
(9) The production of colouring matters by the combination of the sulpho-acid of
Thiometaxylidine with phenols and the sulpho-acids of phenols; substantially as
herein before described.
Dated this 9th day of November A D 1889.
WILLIAM E. HEYS,
Agent for the Applicant.