A Process for Obtaining
Year: 1897

page_text: 1, CHARLES EUGÈNE GASSMANN, of Mulhouse, Alsace, Germany, Doctor, Ingenieur-
Chemiste, do hereby declare the nature of this invention to be as follows:-
This invention relates to a process for obtaining new mordant dyes.
I have found that paranitro-amines, containing a methyl-group in ortho to the
amidic radicle their homologues and sulphonic acids, az tized and combined with
aromatic orthoxycarbonic acids, their sulphonic derivatives, with orthodihydroxyl-or
trihydroxyled aromatic substances. As an example; gaiiic and pyrogallic acids or
1-2 a 3-2 dihydroxy-napthalene, their sulphonic acids, with ortho-amido-naphtols :-as
an example, orthoamidonaphtol 1-2, and their sulphonic acids, give very interesting
and satisfactory dyes, which when fixed on metallic mordants, give very fast yellow-
orange-brown and red colours; while paranitro-benzolazo-salicylic acid gives a brown
orange, the hoinologue paranitro-orthomethylbenzolazo-salicylic acid is a yellow dye
with a very green shade. All these dyes can be solubilised by sulphonation.
Dated the 25th day of October 1897.
WM. BROOKES & SON,
55/56, Chancery Lane, London, W.C., Agents for the Applicant.
A Process for Obtaining New Mordant Dyes.
1, CHARLES EUGÈNE GASSMANN, of Mulhouse, Alsace, Germany, Doctor-Ingenieur-
Chemiste, 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 a process for obtaining new mordant dyes.
I have found that para-nitro-amines, containing a methyl group in the ortho to
amidic radicle, their homologues and sulphonic acids, azotized and combined with.
aromatic orthoxycarbonic acids, their sulphonic derivatives, with orthodihydroxyl
or trihydroxylised aromatic substances-as an example;-gallic and pyrogallic acids,
or 1-2 a 3-2 dihydroxynapthalene, their sulphonic acids, with orthoamido-
naphthols; as an example, orthoamidonaphtol 1-2, and their sulphonic acids, give
very interesting and satisfactory dyes, which when fixed on metallic mordants, give
very fast yellow-orange-brown and red colours; while paranitro-benzolazo-salicylic
acid gives a brown orange, the homologue paranitro-orthomethyl benzol azo-salycylic
acid is a yellow-dye with a very green shade.
These dyes can by sulphonation be solubilised.

page_text: I obtain a mordant dye of a very fine orange shade, whilst the well known
isomeric or homologue combinations are brown without being of any interest
commercially.
For the purpose of my invention I dissolve 15.2 kg. of the said nitrotoluidine
with 3 molecules of aqueous hydrochloric acid and 100 litres boiling water; this
solution is cooled down with the aid of ice to a temperature of 00-5° C. and azotized
by the addition of 7.2 kg. of nitrite of soda in 50 litres of water.
The azotized solution is now introduced into a solution of 18.8 kg. of the said
a-oxynaphtoic acid in 14 kg. of soda lye of 40° Beaumé, with an excess of carbonate
of soda and 300 litres of water.
After four or five hours I proceed to filter and press.
By proceeding in the manner above prescribed, the soda-salt of the dye is
obtained in a slightly soluble condition.
If before filtering an excess of hydrochloric acid is given to the liquid, the acid of
the dye is obtained.
The first is an orange powder when dried and the second is a little more yellow.
In paste form they are of an orange colour. These colours may be fixed on wool with
an orange shade in the presence of chrome as a mordant, and the pastes printed with
acetate of chrome on fabrics give beautiful chestnut coloured effects.
In like manner I have observed that the homologue of the said amine, nitro-
paraxylidine, of the constitution
gives by the same method of treatment with a-oxynaphtoic acid of the above mentioned
constitution a yellow-orange, which resembles very much the described colour.
have therefore come to the conclusion, that by the introduction of the methylic
groups in ortho-to the amidic radicle, yellower shades are given, than such as are
obtained by the inferior homologues such as, for example:--paranitraniline.
I 3

page_text: Following this direction I find that by taking molecular proportions I am able to
obtain the following dyes :-
With resorcylic acid in the absence of alkali, the resorcylic acid being in the state
of fine precipitation, and having the constitution of orthohydroxylised carboxylic
acids :-
OH
-COOH
and
-OH
HO
OH
-COOH
yellow chrome-mordant dyes, slightly soluble as free acids, more as alkaline salts.
In this case I find that the combination of the azotized amine with the resorcylic
acid must be made with an allowance of fourteen days for the completion of the
operation. The resulting precipitate is filtered, dissolved in alkali and the filtered
solution precipitated by the aid of acids. The resulting precipitate is the dye.
With pyrogallic acid in an acid concentrated solution, yellow browns, which also
fix on mordants, are obtained (in this case filter and clear by recrystallization).
With ẞ-oxynaphtoic acid of the PF ("point de fusion") at 216° C. a red is obtained.
If it is desired to obtain dyes of increased solubility in water, I slowly dissolve the
herein before described dried derivatives of the oxynaphtoic acids in sulphuric acid
containing 23 per cent. of anhydric sulphuric acid (taking four parts thereof for one
part of the dye). I have found that the best method is to introduce it at an ordinary
temperature and to heat the mixture to 40°C. until a small quantity of it dissolves
readily in cold ammoniated water. When this point reached it is precipitated in ice
water, washed with water, dissolved in hot diluted alkali and precipitated with the
aid of salt. Then filter, press and dry the result in usual manner.
Dyes so obtained are readily soluble in water and dye mordanted wool the same
shades as the primitive substauce (that is to say dye untreated by sulphuric acid).
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what
I claim is :-
The herein before described manufacture of new mordant dyes by the combina-
tion of the azotized orthomethylic homologues of paranitraniline, such as metanitro-
) orthotoluidine.

page_text: in ortho to a radicle hydroxyl, with soxynaphtoic acid of the F.P. (point de fusion)
2160, with pyrogallic acid.
2. The production of dyes of increased solubility by the sulphonation of the sub-
stances produced by the method of manufacture or production described in
Claim 1.
3. The colouring matters obtained as described.
4. The use of the colouring matters obtained as described.
Dated the 23rd day of July 1898.
WM. BROOKES & SON,
55/56, Chancery Lane, London, Agents for the Applicant.