Year: 1895

page_text: Date of Application, 16th Feb., 1895
Complete Specification Left, 25th Oct., 1895-Accepted, 30th Nov., 1895
I, JOHN IMRAY, of No. 28 Southampton Buildings Chancery Lane, in the
County of London, Consulting Engineer and Chartered Patent Agent, do
hereby declare the nature of this invention to be as follows:-
In the Specification No. 7713 of 1891 colouring matters are described which
can be obtained by combining two molecular proportions of diazo compounds with
one molecular proportion of the 1: 1' amidonaphthol monosulphonic acid described in
the Specification No. 9676 of 1890 or with one molecular proportion of the isomeric
1: 11 amidonaphtholmonosulpho acid which can be obtained by melting with a
caustic alkali the naphthylamine disulpho acid prepared by sulphonating the
naphthylamine monosulpho acid S of the German Patent No. 40571.
It is now known that the constitution of these two isomeric acids can be expressed
by the following formulæ :-
Two directions are given according to which the new umzo dyestuns may be
prepared.
According to the first method, the combination of two molecular proportions of
a diazo compound with one molecular proportion of 1:11 amidonaphtholmono-
sulphonic acid is effected in a solution which is alkaline throughout.
According to the second method only the second combination is effected in
alkaline solution, the first being effected in acid solution.
Neither the one or the other of these two methods is practised so smoothly as is
usually the case in preparing azo dyes, and this fact explains why colouring matters
prepared according to these processes have not hitherto, so far as is known, been
brought into the market.
My foreign correspondents have discovered a third process for preparing disazo
dyes from amidonaphtholsulpho acid and two molecular proportions of diazo bodies,
which presents, in its main points, very remarkable varieties.

page_text: According to their researches, good results are only obtained when the second
combination is performed in a weak acid solution, and not, as is described in the
Patent above referred to, in an alkaline solution. This is of especial importance
when two different molecules of a diazo compound are combined with one molecule
of 11' amidonaphtholmonosulphonic acid (so called mixed disazo dyes). If the
combination be effected under these conditions it is effected very smoothly and the
colouring matters which are obtained are quite different from and superior to those
described in the Specification No. 7713 of 1891.
Of the different combinations possible, the following example may be chosen to
show on the one hand how the invention can be practically carried out, and, on
the other hand, to show the varieties of the resulting colouring matters obtained
under the conditions now given and those set forth in the Specification No. 7713
of 1891.
15 kilos. a-naphthylamine are converted in the well known manner into diazo-
naphthaline which solution is poured into an alkaline solution of 24 kilos. of
11 amidonaphtholmonosulphonic acid. After the formation of the azo compound
is completed, the whole is acidulated by means of acetic acid, and a solution of
para-diazobenzolsulphonic acid is added (obtained from 19.5 kilos. of sulphanilic
acid).
After the combination is completed the colouring matter is separated out with
salt, filtered and dried.
The dyestuff thus obtained dyes wool a greenish blue-black in an acidulated
bath.
If the combination with the same components be carried out under the
conditions given in the Specification No. 7713 of 1891 the resulting colouring
matter will dye wool violet blue tints.
Another special difference exists between the solutions of the two products in
concentrated sulphuric acid. The solution of the colouring matter prepared
according to the method herein described is pure blue and, by diluting it with
water, a blue black precipitate is formed, whilst the colouring matter prepared
according to the methods described in the Specification above referred to,
dissolves in concentrated sulphuric acid with a blue black colour, and the
precipitate formed by diluting with water is of a pronounced blue violet colour.
Dated this 16th day of February 1895.
ABEL & IMRAY,
Agents for the Applicant.
I, JOHN IMRAY, of No. 28 Southampton Buildings, Chancery Lane, in the
County of London, Consulting Engineer and Chartered Patent Agent, 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:-
In the Specification No. 7713 of 1891 colouring matters are described which can
be obtained by combining two molecular proportions of diazo compounds with one
molecular proportion of the 1: 1' amidonaphtholmonosulphonic acid described in
the Specification No. 9676 of 1890 or with one molecular proportion of the isomeric
1: 1 amidonaphtholmonosulpho acid which can be obtained by melting with a
caustic alkali the naphthylamine disulpho acid prepared by sulphonating the
naphthylamine monosulpho acid S of the German Patent No. 40571.

page_text: According to the first method, the combination of two molecular proportions of a
diazo compound with one molecular proportion of 1:11 amidonaphthol mono-
sulphonic acid is effected in a solution which is alkaline throughout.
According to the second method, only the second combination is effected in
alkaline solution, the first being effected in acid solution.
The latter method is said in the Specification No. 7713 of 1891 to be generally.
recommended and in the corresponding French (Certificate of Addition dated
26th August 1891 to the Patent No. 213232) it is even indicated as being more
advantageous.
Neither the one or the other of these two methods is practised so smoothly as is
usually the case in preparing azo dyes, and this fact explains why colouring matters
prepared according to these processes have not hitherto, so far as it is known, been
brought into the market.
My foreign correspondents have discovered a third process for preparing disazo
dyes from amidonaphtholsulpho acid and two molecular proportions of diazo bodies,
which presents, in its main points, very remarkable varieties.
According to their researches, good results are only obtained when the second
combination is performed in a weak acid solution, and not, as is described in the
Patent above referred to, in an alkaline solution. This is of especial importance
when two different molecules of a diazo compound are combined with one molecule
of 1: 11 amidonaphtholmonosulphonic acid (so called mixed disazo dyes). If the
combination be effected under these conditions it is effected very smoothly and the
colouring matters which are obtained are quite different from and superior to those
described in the Specification No. 7713 of 1891.
Of the different combinations possible, the following example may be chosen to
show on the one hand how the invention can be practically carried out, and, on the
other hand, to show the varieties of the resulting colouring matters obtained
under the conditions now given and those set forth in the Specification No. 7713
of 1891.
15 kilos. a-naphthylamine are converted in the well known manner into diazo-
naphthaline which solution is poured into an alkaline solution of 24 kilos. of
11 amidonaphtholmonosulphonic acid. After the formation of the azo compound
is completed, the whole is acidulated by means of acetic acid, and a solution of
para-diazobenzol-sulphonic acid is added (obtained from 19.5 kilos. of sulphanilic
acid).
After the combination is completed the colouring matter is separated out with
salt, filtered and dried.
The dyestuff thus obtained dyes wool a greenish blue-black in an acidulated
bath.
If the combination with the same components be carried out under the conditions
given in the Specification No. 7713 of 1891 the resulting colouring matter will dye
wool violet blue tints.

page_text: Another special difference exists between the solutions of the two products in
concentrated sulphuric acid. The solution of the colouring matter prepared
according to the method herein described is pure blue and, by diluting it with
water, a blue black precipitate is formed, whilst the colouring matter prepared
according to the methods described in the Specification above referred to, dissolves
in concentrated sulphuric acid with a blue black colour, and the precipitate formed
by diluting with water is of a pronounced blue violet colour.
Analogous colouring matters may be obtained if, for the diazo compounds used
in the above example, other diazo compounds, suitable for the production of azo
dyestuffs, be substituted.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
one
1. The herein described manufacture of azo dyes by combining one molecular
proportion of alpha,-alpha-amidonaphthol-alpha,-monosulphonic acid with
molecular proportion of a diazo compound in alkaline solution, and coupling the
combination products thus obtained in acid solution with one more molecular
proportion of a diazo compound.
2. The azo dyes manufactured as above set forth.