Improvements in the Manufacture and Production of Colouring Matters from Dihydroxybenzoic Acid.
Year: 1890

page_text: Date of Application, 7th Aug., 1890
Complete Specification Left, 4th May, 1891-Accepted, 6th June, 1891
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture and Production of Colouring
Matters from Dihydroxybenzoic Acid.
I, JAMES YATE JOHNSON of 47 Lincolns Inn Fields, in the County of Middlesex
Gentleman do hereby declare the nature of this invention (which has been com-
municated to me from abroad by The Badische Aniline and Soda Fabrik of
Ludwigshafen on the Rhine in the Empire of Germany) to be as follows:-
:-
It is known that a symmetrical dihydroxybenzoic acid C,H,. COOH. OH. OH
(1. 3. 5) can be obtained by melting meta-disulpho-benzoic acid with an excess of
caustic potash (Barth and Senhofer, Annalen der Chemie 159, 222) but no means
so far as I am aware have hitherto been discovered of technically applying this
compound in the manufacture of colouring matters.
My foreign correspondents have discovered that by causing nitroso-derivatives
of tertiary aromatic bases to act on the said dihydroxy-benzoic acid, new and
valuable colouring matters can be obtained which can be applied to wool with or
without the aid of a mordant and which also can be used in dyeing and printing
suitably mordanted vegetable fibre.
The condensation of the symmetrical dihydroxybenzoic acid with the above
mentioned nitroso-derivatives can be effected in aqueous, alcoholic or acetic acid
solution and usually takes place at temperatures below one hundred degrees
Centigrade.
To illustrate the nature of this invention I give by way of example the following
directions for preparing a new colouring matter from symmetrical dihydroxy-
benzoic acid and nitroso-dimethyl-aniline but I wish it to be understood that I do
not limit myself to the details given in this example.
Dissolve about ten parts by weight of symmetrical dihydroxybenzoic acid in
about one thousand parts by weight of water, raise the temperature to about
seventy degrees Centigrade and when at this temperature and whilst being con-
tinuously stirred gradually add about twelve parts by weight of the hydrochloric
acid, salt of nitroso-dimethyl-aniline. Allow the mixture to stand for, say about
five hours during which the new colouring matter separates out as a crystalline
precipitate shewing a metallic lustre. Filter and wash with cold water. The
paste or pulp so obtained can be applied at once to dyeing and printing, or the
colouring matter can first be further purified by dissolving it in dilute soda
solution, filtering and precipitating the filtrate with an acid.
The nitroso-dimethyl-aniline can be used in forms other than the hydrochlorate,
for instance as free base or in the form of salts with other acids.
In employing for the purposes of this invention nitroso-derivatives of other
tertiary aromatic bases, it is sometimes advisable to vary the conditions of the
example, for instance, it appears to be best, when using nitroso-diethyl-aniline to
effect the condensation in glacial acetic acid solution; but in other respects the
process is similar to that herein before described.
The new colouring matters obtained according to this invention appear to
resemble one another closely in their physical properties. They yield violet-black
crystals having a metallic lustre and but slightly soluble in cold water, but readily
soluble in alkalies yielding beautiful blue solutions. The alcoholic solutions are
reddish blue or violet, and possess a strong red fluorescence.
By dyeing wool either directly or with the aid of a chrome mordant bright
shades of blue and violet are obtained, and similar shades can be printed or dyed
pon cotton with the aid of a chrome or other suitable mordant. The colouring

page_text: matter from nitroso-diethyl-aniline gives a less violet shade of blue than does that
from nitroso dimethyl-aniline.
The new colouring matters surpass in the beauty and brilliancy of the shades
obtainable with them all those having similar dyeing properties hitherto known.
They are further characterized by the valuable property of dyeing well in mixture
with other dyestuffs, which fix themselves on chrome mordants; in particular, a
mixture of alizarine blue and one of the new dyestuffs, gives more brilliant shades
than can be obtained by using alizarine blue alone.
Dated this 7th day of August 1890.
Improvements in
COMPLETE SPECIFICATION.
the Manufacture and Production of Colouring
Matters from Dihydroxybenzoic Acid.
I JAMES YATE JOHNSON of 47 Lincolns Inn Fields in the County of Middlesex,
Gentleman, do hereby declare the nature of this invention (which has been com-
municated to me from abroad by The Badische Anilin and Soda Fabrik of
Ludwigshafen on Rhine in the Empire of Germany) and in what manner the same
is to be performed to be particularly described and ascertained in and by the
following statement :-
It is known that a symmetrical dihydroxybenzoic acid C,H,. COOH. OH. OH
(1.3.5) can be obtained by melting meta-disulpho-benzoic acid with an excess of
caustic potash (Barth and Senhofer, Annalen der Chemie 159, 222) but no means
have so far as I am aware hitherto been discovered of technically applying this
compound in the manufacture of colouring matters.
My foreign correspondents have discovered that by causing nitroso-derivatives
of tertiary aromatic bases such as di-methyl-aniline, diethyl-aniline, methyl-benzyl-
aniline and ethyl-benzyl-aniline to act on the said di-hydroxy-benzoic-acid, new
and valuable colouring matters can be obtained which can be applied to wool
without the aid of a mordant and which also can be used in dyeing chrome
mordanted wool.
The condensation of the symmetrical dihydroxy-benzoic-acid with the above
mentioned nitroso derivatives can be effected either in aqueous or in alcoholic or
in other cases, in acetic acid solution.
As an example to illustrate the manner in which my invention can be carried
into practical effect I give the following directions for preparing a new blue
colouring matter from symmetrical dihydroxy-benzoic acid and nitroso-dimethyl-
aniline premising that I do not limit myself to the precise details given.
Dissolve about ten parts by weight of symmetrical dihydroxy-benzoic acid in
about one thousand parts by weight of water, raise the temperature to about
seventy degrees Centigrade then add gradually about twelve parts by weight of
the hydrochloric acid salt of nitroso-dimethyl-aniline. Stir continuously during
the addition and subsequently allow the mixture to stand for, say, about five hours,
during which the new colouring matter separates out as a crystalline precipitate,
shewing a metallic lustre. Filter and wash with cold water. The paste or pulp
so obtained can be applied at once to dyeing and printing, or the colouring matter
can first be further purified by dissolving it in dilute soda solution, filtering, and
precipitating the filtrate with an acid.
The nitroso-dimethyl-aniline can be used in forms other than the hydrochlorate
for instance as free base or in the form of salts with other acids.
In place of the nitroso-dimethyl-aniline, the equivalent quantity of other nitroso
derivatives of tertiary aromatic bases such as those of diethyl-aniline; methyl-
benzyl-aniline or ethyl-benzyl-aniline may be used as hereinbefore described.
The new colouring matters obtained according to this invention resemble one

page_text: another closely in their physical properties. They yield dark coloured crystals
with a metallic lustre and are but slightly soluble in cold water, but are readily
soluble in alkalis, yielding beautiful blue solutions. The alcoholic solutions are
reddish-blue or violet in colour and possess a strong fluorescence.
The new dyes fix themselves on wool without the aid of a mordant and can also
be dyed on wool which has received a chrome mordant; the mordant does not
however affect the dye in any way. This property is of value inasmuch as it
renders it possible to use the new dyes in mixture with such as fix themselves on a
chrome-mordant, thus for instance more beautiful shades of blue can be obtained
with alizarine blue and my new dye from nitroso-dimethyl-aniline together, than
with alizarine blue alone. The new colouring matters surpass, in the beauty and
brilliancy of the shades obtainable with them all those having similar dyeing
properties.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed 1 declare that what I
claim is :-
1. The manufacture of dye-stuffs by causing the nitroso derivatives of the tertiary
aromatic bases to act upon symmetrical di-hydroxy-benzoic acid.
2. The manufacture of dyestuff's by causing the nitroso derivatives of the tertiary
aromatic bases hereinbefore mentioned to act upon symmetrical di-hydroxy-benzoic
acid, substantially in the manner hereinbefore described.
3. As a new inanufacture the dyestuff's hereinbefore described and produced
according to the process claimed under the preceding claiming clauses.
Dated this 10th day of April 1891.
J. H. JOHNSON & Co.,
47, Lincoln's Inn Fields, Agents.