The Production of New Azo-coloring Matters.
Year: 1889

page_text: Date of Application, 10th Sept., 1889
Complete Specification Left, 10th July, 1890-Accepted, 10th Nov., 1890
PROVISIONAL SPECIFICATION.
The Production of New Azo-coloring Matters.
We, ARTHUR GEORGE GREEN, and THOMAS ATKINSON LAWSON, Chemists to the
firm of Brooke Simpson & Spiller Limited, of Atlas Works, Hackney Wick, in the
County of Middlesex, Aniline Dye Manufacturers, do hereby declare the nature of this
invention to be as follows :-
Our invention relates to the preparation of azo-colors of various shades of yellow,
orange, and red, most of, which have a decided substantive affinity for cotton. These
colors are obtained by combining any of the known phenols or amines, or their
sulphonic or carboxylic acids with the tetrazo compounds of either of the following
bases:
Para azoxy- ortho- toluidine [1:2:4] CH, (CH) (NH). N, O. C, H, (NH,)
(CH3) [421], which melts at about 168° C.
Para- azo- ortho- toluidine [1:2 : 4] C. H₂ (CH) (NH₂). N. CH₂ (NH₂)
(CH) [421], which melts at about 197° C.
Para- hydrazo- ortho- toluidine [1:24] C, H, (CH) (NH) (N, H.) (H,
(NH2) (CH) [421], which decomposes at a high temperature without
melting.
These three bases are described by Limpricht in 1885 (see Berichte of the German
Chemical Society, XVIII page 1403), and are obtained progressively by the alkaline
reduction of para- nitro- ortho- toluidine C, H, (CH) (NH) (ÑO₂) [1: 2: 4].
The conversion into dye stuffs is performed according to the well known methods used
in the preparation of the azo colors. Both diazo groups of the tetrazo-compound
may be combined with the said phenol or amine, or one may be combined with one
phenol or amine, and the other with a different phenol or amine according to methods
now well known to chemists. As an instance of the application of this invention
the preparation of a bluish red color may be given, for which purpose we may proceed
as follows:-
A solution of 25 lbs. of the above mentioned azoxy-toluidine in 200 gals. of water
and 4 gals. of hydrochloric acid are quickly added to an iced solution of 14 lbs. of
sodium nitraté (96 %) in 20 gals. of water. The solution of the tetrazo compound
thus obtained is now run into a solution containing 50 lbs. of sodium and naphthol-
para sulphonate (corresponding to Piria's naphthionic acid) and kept alkaline by.
sodium carbonate or ammonia. The coloring matter is precipitated by the addition
of salt filtered off and dried.
It dyes cotton from an alkaline bath without a mordant. The properties of the
product are not much altered, if in the above example the 25 lbs. of azoxy-toluidine
are replaced by 24 lbs. of the above mentioned azotoluidine or by 24 lbs. of the
above mentioned hydrazótoluidine.
Dated this 10th day of September 1889.
:
J

page_text: COMPLETE SPECIFICATION.
The Production of New Azo-coloring Matters.
We, ARTHUR GEORGE GREEN, and THOMAS ATKINSON LAWSON, Chemists to the
firm of Brooke Simpson & Spiller Limited, of Atlas Works Hackney Wick in the
County of Middlesex, Aniline Dye Manufacturers 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:-
Our invention relates to the preparation of azo colours of various shades of yellow,
orange, and red, most of which have a decided substantive affinity for cotton. These
colours are obtained by combining any of the known phenols, or amines, or their
sulphonic, or carboxylic acids (such as are capable of combining with diazo
compounds in general) with the tetrazo compounds of either of the two following
bases.
Para azoxy- ortho- toluidine [1: 2: 4] C, H, (CH) (NH2). N, O. C, H,
(NH₂) (CH₂) [4:21], which melts at about 168° Cente.
Para- azo- ortho- toluidine [124] H, (CH₂) (NH₂) N2. C₁ H3 (NH2)
(CH) [421], which melts at about 197°° C'ente.
These bases were described by Limpricht in 1885 (see Berichte of the German
Chemical Society, XVIII, page 1403) and are obtained progressively by the
alkaline reduction of para- nitro- ortho- toluidine, C, H₂ (CH) (NH₂) (NO2)
[124].
The very important object we wish to attain in the first place, is the preparation of
either one of these two bases, as may be required, in considerable and definite
quantities, unmixed with the other, or so mixed only to a very slight degree.
We have found that by employing an aqueous solution of sodium stannite, in
certain suitable proportions, as the reducing agent, para-, nitro- ortho- toluidine
(melting point 107° C.) can be readily and quantitatively converted into para- azoxy-
ortho- toluidine, and the process of reduction may be stopped here, or the para- azoxy-
ortho- toluidine can be further reduced to para- azo- ortho- toluidine, by treatment in
alcoholic solution with a further quantity of sodium stannite. The tin used in the
reduction, may be recovered, and employed for the preparation of a fresh quantity of
sodium stannite.
In accordance with this part of our invention, in preparing para- azoxy- ortho-
toluidine, 16 pounds of para- nitro- ortho- toluidine (melting point 107° C.) are
suspended and partially dissolved in 150 gals. of boiling water. A cold solution of
sodium stannite, prepared by adding 40 pounds of tin crystals (Stannous chloride)
dissolved in 10 gals. of water, to 40 pounds of caustic soda (98% of Na HO)
dissolved in 30 gals. of water, is run into the boiling liquor. The azoxy- ortho-
toluidine separates out completely from the boiling solution and is filtered off and
washed. It is then dissolved in 60 gals. of boiling water and 2 gals. of hydrochloric
acid, filtered, and the hydrochloride precipitated from the filtrate by the addition of an
excess of hydrochloric acid. From the hydrochloride, the base is obtained by
dissolving it in boiling water and precipitating with an alkali.
para-
The para- azo- ortho- toluidine is prepared by dissolving 15 pounds of the
ázoxy- ortho- toluidine in 35 gals. of methylated spirit (90% alcohol), to the boiling
alcoholic solution is added a solution of sodium stannite, prepared by adding 15 pounds
of tin crystals (Stannous chloride) dissolved in 2 gals. of spirit, to 15 lbs. caustic
soda (98% Na HO) dissolved in 5 gals. of water. The whole is kept boiling till the
reaction is complete, and it is then poured into several times its bulk of water. The
precipitated azo- ortho- toluidine, is filtered off and washed. For further purification
it can be dissolved in dilute hydrochloric acid, filtered and precipitated as hydro-
chloride from the filtrate by the addition of an excess of hydrochloric acid.
Either of the two bases, obtained, as above described in large and definite
quantities, and unmixed, or mixed to only a very slight degree or extent with the other
base, is converted into dye stuffs in accordance with the well known methods used in

page_text: the preparation of the azo colours. Both diazo groups of the tetrazo compound may
be combined with the same phenol or amine, or one may be combined with one phenol
or amine, and the other with a different phenol or amine, according to methods now
well known to chemists.
As an instance of the application of the second part of this invention, the pre-
paration of a bluish red colour may be given. For this purpose we proceed as
follows: A solution of 14 lbs. of sodium nitrite (96%) in 20 gals. of water is added
slowly to an iced solution of 25 lbs. of the aforesaid azoxy- ortho- toluidine in
100 gals. of water, containing 5 gals. of hydrochloric acid (33% H Cl). The solution
of the tetrazo compound, thus obtained, is then added to a solution containing 50 lbs.
of sodium, alpha- naphthol- para- sulphonate (corresponding to Piria's naphthionic
acid) and about 20 lbs. of "pure alkali" (commercial anhydrous sodium carbonate)
in 50 gals. of cold water. The red colouring matter which is formed is precipitated
by salt, filtered and dried. It dyes cotton from an alkaline bath without a mordant.
A very similar color is obtained, if in the above example the 25 lbs. of azoxy-
ortho- toluidine is replaced by 24 lbs. of the above mentioned azo- ortho- toluidine,
the rest of the substances remaining the same. Less useful colouring matters are
obtained if the sodium- alpha- naphthol para- sulphonate be replaced by the same
weight of the sodium salt of any other mono- sulphonate of alpha- or beta-
naphthol.
Colouring matters are also obtained by combining the tetrazo compound of azoxy-
ortho- toluidine, or of azo- ortho- toluidine, with phenyl, salicylic acid, phenylene
diamine, tolylene diamines, diphenylamine sulphonic acids, resorcine, resorcylic acid,
orcin, the sulphonic acids of alpha- or beta- naphthylamine or of their alkylated
derivatives, phenyl- or tolyl- naphthylamine sulphonic acids, dioxynaphthalene
sulphonic acids &c. &c. The tetrazo compound may be combined with two molecules
of any of these bodies, or with one molecule of one and one molecule of another, in
the manner well known to chemists.
We do not lay claim to the discovery of azoxy- or azo- ortho- toluidine as new
bodies, for, as above stated, they have already been described by Limpricht, nor do we
claim the method of reducing nitro- ortho- toluidine, so as to obtain these bodies
mixed together in indefinite proportions nor do we claim the method of diazotization
of these bodies, but what we believe to be novel is the preparation of these bodies
by the process as described, separately, and in large and definite amounts, unmixed
with one another.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :-
1. The preparation of azoxy- and azo- ortho- toluidine, by the alkaline reduction,
with sodium stannite of nitro- ortho- toluidine, in the manner described.
2. The preparation of colouring matters by diazotising either of the compounds
azoxy-, or azo- ortho- toluidine, when obtained as above described, and combining the
tetrazo compound so obtained with the sulphonic acids of various phenols and amines,
more especially with the para-sulphonic acid of alpha naphthol (corresponding to
Piria's naphthionic acid) substantially as herein set forth.
3. The colouring matters prepared in the manner substantially as herein set
forth.
Jun way
о цу
AMBROSE MYALL,
21, Cockspur Street, S.W., Agent for the Applicants.