IMPROVEMENTS IN THE MANUFACTURE OR PRODUCTION OF COLOURING MATTERS OBTAINED FROM SULPHO-DERIVATIVES OF BENZIDINE AND IN THE PREPARATION OF SUCH SULPHO DERIVATIVES
Year: 1884

page_text: I JOHN PETER GRIESS of Burton-on-Trent Chemist do hereby declare the nature
of said Invention for "IMPROVEMENTS IN THE MANUFACTURE OR PRODUCTION OF
COLOURING MATTERS OBTAINED FROM SULPHO-DERIVATIVES OF BENZIDINE AND IN
THE PREPARATION OF SUCH SULPHO DERIVATIVES," to be as follows:-
I discovered some years ago that a Sulpho derivative of Benzidine (called
Benzidine di Sulphonic acid) could be obtained and that coloring matter could be
produced from it; but no useful application of my said Invention was ever made.
I have now discovered that certain other sulpho derivatives of Benzidine may be
prepared and valuable coloring matters may be prepared therefrom. My present
Invention consists in the preparation of four new Sulpho derivatives of Benzidine
and their conversion into coloring matters. These new Sulpho Derivatives may
in chemical language be termed Benzidine trisulphonic acid, Benzidine tetra
Sulphonic acid, Benzidine Sulphon-monosulphonic acid and Benzidine Sulphon
Disulphonic Acid respectively and their respective chemical composition may be
expressed as follows
CULO
carried out.
One part of Sulphate of Benzidine is gradually introduced into about 3 or 4 parts
of Fuming Sulphuric Acid and both heated together for one hour at about from
170 to 200 Centigrade care being taken that no charring takes place.-I now
introduce the mixture under stirring into about 20 parts of cold water by means
of which the Benzidine Sulphon-Mono-Sulphonic acid and Benzidine Sulphon-
disulphonic acid (and also some Benzidine di Sulphonic acid which may be present)
are separated whilst the Benzidine trisulphonic acid and Benzidine tetra sulphonic
acid remain dissolved and may be obtained in a crystalline state by concentrating
the filtered solution and then removing the excess of sulphuric acid by means of
straining or otherwise.

page_text: In order to separate the Benzidine Sulphon Monosulphuric acid from the
Benzidine Sulphon disulphonic acid I prefer to heat the mixture repeatedly with
boiling water, by means of which the latter compound is extracted whilst the
Benzidine Sulphon Monosulphonic acid (together with some Benzidine-disulphonic
acid that may be present) remains undissolved.
The Benzidine Sulphon-Disulphonic acid can be obtained in a solid state either
by evaporation or by precipitating it with Hydrochloric acid or common salt from
its previously sufliciently concentrated solution.
In order to remove the Benzidine di sulphonic acid which may be mixed with
the Benzidine sulphon mono-sulphonic acid I prefer to convert these acids into their
calcium salts and separate the somewhat insoluble calcium salt of the Benzidine
sulphon monosulphonic acid from the easily soluble calcium salt of the Benzidine
disulphonic acid by means of crystallization.
In like manner the separation of Benzidine tri sulphonic acid and Benzidine
tetrasulphonic acid may be effected by converting them into their Barium salts.
The Barium salts of the first named acid being easily soluble and that of the latter
not readily soluble in water, but for the preparation of colouring matter I prefer to
use the mixture of these acids.
Considering that the dyes produced by means of Benzidine sulphone disulphonic
acid are superior to those produced from Benzidine sulphon mono sulphonic acid
I prefer in most instances to convert the latter compound into the former, which
1 effect by heating it for a' out 1 hour with twice its weight of Fuming Sulphuric
acid.
To produce coloring matter from the above mentioned new derivatives 1 convert
the same into their corresponding Tetrazo compounds which I combine in a manner
well understand by Chemists with Amines and Phenoles and the sulpho acids
thereof.
Under the names of Amines I especially include Alpha and Beta Napthylamine
and Methyl and Phenyl Napthylamines and their homologues and also the sulpho
acids of these Amines.
Under the name of Phenols I especially include alpha and beta napthol and their
sulpho acids.

page_text: I JOHN PETER GRIESS of Burton on Trent Chemist do hereby declare the
nature of said invention for "IMPROVEMENTS IN THE MANUFACTURE OR PRO-
DUCTION OF COLORING MATTERS OBTAINED FROM SULPHO DERIVATIVES OF
BENZIDINE AND IN THE PREPARATION OF SUCH SULPHO DERIVATIVES und in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement :-
"
I discovered some years ago that a sulpho derivative of Benzidine (called
Benzidine di-sulphonic acid) could be obtained and that coloring matter could be
produced from it but no useful application of my said discovery was ever made
I have now discovered that certain other sulpho derivatives of Benzidine may bo
prepared and valuable coloring matters may be prepared therefrom-My present
Invention consists in the preparation of four new sulpho derivatives of Benzidino
and their conversion into coloring matters-These new sulpho derivatives may in
chemical language be termed Benzidine, Trisulphonic Acid Benzidine, Tetra-
sulphonic Acid, Benzidine Sulphon monosulphonic acid and Benzidine Sulphon
Disulphonic Acid respectively and their respective chemical composition may be
be carried out in practice.
One part of Sulphate of Benzidine is gradually introduced into about 3 or 4
parts of Fuming Sulphuric Acid and both are heated together for one hour at about
from 170° to 200° Centigrade care being taken that no charring takes place. I now
introduce the mixture under stirring into about 20 parts of cold water by means
of which the Benzidine sulphon-mono-sulphonic acid and Benzidine Sulphon
disulphonic acid (and also some Benzidine Di Sulphonic acid which may be
present) are separated whilst the Benzidine trisulphonic Acid and Benzidine
tetrasulphonic acid remain dissolved and may be obtained in a crystalline state by
concentrating the filtered solution and then removing the excess of sulphuric acid
by means of straining or otherwise.
In order to separate the Benzidine Sulphon mono-sulphuric acid from the
Benzidine sulphon disulphonic Acid prefer to treat the mixture repeatedly with
boiling water by means of which the latter compound is extracted whilst the
Benzidine Sulphion-monosulphonic acid (together with some Benzidine-disulphonic
acid that may be present) remains undissolved.
The Benzidine Sulphon-Disulphonic acid can be obtained in a solid state either
by evaporation or by precipitating it with hydrochloric acid or common salt from
its previously sufficiently concentrated solution.
In order to remove the Benzidine di-sulphonic acid (which may be mixed with
the Benzidine Sulphon mono-sulphonic acid) I prefer to convert these acids into
their calcium salts and separate the somewhat insoluble calcium salt of the
Benzidine sulphon-mono-sulphonic acid from the easily soluble calcium salt of the
Benzidine disulphonic Acid by means of crystallization.
In like manner the separation of Benzidine trisulphonic acid and Benzidine
tetrasulphonic acid may be effected by converting them into their Barium Salts-
The Barium Salts of the first named acid being easily soluble and that of the
latter not readily soluble in water but for the preparation of coloring matter I
prefer to use the mixture of these acids.

page_text: Considering that the dyes produced by means of Benzidine Sulphon disulphonic
Acid are superior to those produced from Benzidine sulphon mono-sulphonic acid
I prefer in inost instances to convert the latter compound into the former which
I effect by heating it for about one hour with twice its weight of Fuming sulphuric
Acid.
To produce coloring matter from the above mentioned new derivatives 1 convert
the same into their corresponding Tetrazo compounds which I combine in a manner
well understood by Chemists with Amines and Phenols and the Sulpho acids
thereof.
Under the name of Amines I especially include Alpha and Bela Napthylamine
and Methyl and Phenyl Napthylamines and their hoinologues and also the sulpho
Acids of these Amines.
Under the name of phenols I especially include Alpha and Beta Napthol and
their sulpho acids.
The following is the way in which an Indigo blue dye may be prepared.
10 of dry Benzidine Sulphon-Disulphonic acid are heated with about 100¹³ of
water then mixed with about 5 lbs of strong hydrochloric acid and afterwards left
to cool To the cold mixture is now very gradually added an aqueous solution of
commercial Nitrite of Sodium containing about 3 lbs G oz of pure Nitrite of Sodium
and then left to stand for about 6 hours-If the whitish pasto of the Tetrazo-
compound of Benzidine-Sulphon Disulphonic acid thus obtained be now poured
into a solution of about 8 lbs of Dimethyl-Beta Napthylamine in very dilute
Hydrochloric acid the formation of the dye soon begins and is accelerated by
occasional stirring; after the lapse of about 24 hours it may be considered complete-
The blue dye thus formed is now separated from the mother liquor by filtration
washed pressed and dried or if preferred may be used as a paste.
The following is the way in which a dye may be prepared that imparts to cotton
fabrics a dark red color.
10 of Benzidine-tri-sulphonic acid are converted into the corresponding Tetrazo
compound by treating with 2 equivalents of pure Nitrito of Soda in a manner
similar to the one mentioned above-This Tetrazo compound is then gradually
introduced into a cold. alkaline solution of Beta Naphtol which may be prepared
by dissolving about 63%, lbs of Beta Naphtol in about 50 lbs of water and about
14 lbs of a solution of Caustic Soda of a specific gravity of about 1-37-The brown
red mixture thus obtained which throughout this operation is to be kept alkaline
is then precipitated with Hydrochloric acid or Chloride of Sodium and the
precipitate of the coloring matter filtered pressed and dried or if preferred used
as a paste.
Having now particularly described and ascertained the nature of my said
Invention and in what manner the same is to be performed I declare that what
I claim is
The preparation of the Sulpho derivatives of Benzidine herein before termed
Benzidine Trisulphonic Acid, Benzidine, Tetrasulphonic acid Benzidine Sulphon-
inono-Sulphonic acid Benzidine Sulphon Disulphonic acid and also their conversion
into coloring matters all substantially as hereinbefore described.
Dated this 2nd day of September 1884.
J. P. GRIESS.
J. Henry Johnson,
47, Lincoln's Inn Fields, London, W.C.,
Agent for the said John Peter Griess.