The Preparation of New Sulphonic Acids for the Production of a Blue Colouring Matter for Cotton.
Year: 1890

page_text: Date of Application, 23rd Apr., 1890
Complete Specification Left, 21st Jan., 1891-Accepted, 7th Mar., -1891
PROVISIONAL SPECIFICATION,
[Communicated from abroad by DIE CHEMISCHE FABRIK GRÜNAN, LAND-
SHOFF & MEYER, in Grünan, near Berlin, in the Empire of Germany,
Manufacturing Chemists.]
The Preparation of New Sulphonic Acids for the Production of a
Blue Colouring Matter for Cotton.
I, SAMUEL SIDNEY BROMHEAD, of 97. Newgate Street, London, Patent Agent,
(communicated), do hereby declare the nature of this invention to be as
follows:-
This invention consists of a process for the preparation of a blue colouring matter
for cotton as herafter explained.
When a salt of naphthionic acid, preferably the very soluble sodaic salt found in
commerce is heated for some time at a temperature of from 190° to 250° C., the same
is converted into a not readily soluble salt of an isomeric acid hitherto unknown.
While the diluted solutions of this naphthionate produce an intensely violet
fluorescence, the neutral solution of the new acid exhibits only a very feeble reddish
fluorescence. On adding mineral acids to the solutions of its salts the new acid
gradually separates, in a contrary manner to its isomeres, in the form of well shaped
crystals. Its diazo compound crystallises in small greenish yellow scales, and is
converted by boiling with diluted sulphuric acid into a readily soluble
a-naphthol-sulphonic acid and produces a dichloro-naphthaline the melting point of
which is from 34 to 35 C.
The new acid further differs very considerably from all a-naphthylamine-
sulphonic acids owing to the important yellow tints of the azo-colouring material
produced therefrom. Should the new a-naphthylamine-sulphonic acid be treated at
the ordinary temperature with fuming sulphuric acid a likewise new a-naphthyl-
amine disulphonic acid will be formed, which acid is not readily soluble and forms
acrid alkaline salts. Its acid as well as neutral solution produces a characteristic
greenish blue fluorescence. By treatment with nitrite of soda in an acid solution
its diazo-compound is obtained, and crystallises in the form of small brilliant light.
yellow needles.
This a-naphthylamine-disulphonic acid differs also from the hitherto known
isomeres by the prominent yellow tint of the azo-colouring matter extracted,
therefrom.
When the sodaic salt of this a-naphthylamine-disulphonic acid is heated for a long
time in an antoclave with soda lyes, at a temperature of from 200 to 250° C., an
amido naphthol-monosulphonic acid is obtained. This combined with tetrazo-
diphenyl produces in a solution of acetic acid or in an alkaline solution, a colouring
matter which gives cotton in a neutral or slightly alkaline solution a clear blue
dye, without mordant.
DESCRIPTION OF THE PROCESS.
Sodaic naphthionate is heated in a boiler or cylinder, arranged longitudinally
and provided. with an agitator, to a temperature of from 220 to 240° C. until its
full conversion into a salt of the new acid is effected, this being ascertained by
testing the partial insolubility of the product in water, and by finding out the
disappearance of the intense violet blue fluorescence produced by the diluted
solution of the former. To prevent oxidation, a slow current of carbonic acid is
passed through the mass. The product of the re-action is dissolved almost without

page_text: residuum in boiling water, and can be still further purified by successive crystal-
lisation from the same.
The process may be also carried out at a lower temperature than the above but
consumes accordingly a longer time.
The new naphthylamine-sulphonic acid is precipitated by means of sulphuric acid
from the solution of the sodaic salt thus produced, and after being dried, and
pulverized while cooled, it is gradually incorporated with four parts of fuming sulphuric
acid containing 10% of anhydride.
The solution thus produced forms a crystalline mass after it has been allowed to
stand for several hours. This mass is mixed when cool with two parts of water
when the main portion of the new disulphonic acid separates in a crystalline form.
This acid is very easily soluble in water, but scarcely soluble in diluted sulphuric
acid.
The remainder is obtained in the form of a sparingly soluble acid of the sodaic
salt by adding common salt or sulphate of soda to the filtrate.
The sparingly soluble acids of alkaline salts obtained from the new disulphonic
acid, can also be produced directly by dissolving in fuming sulphuric acid the alkaline
salts of the mono-sulphonic acids instead of the free acids, and by decomposing the
product with water after the re-action is terminated.
Instead of the fuming sulphuric acid a combination of sulphuric acid mono-chlor-
hydrine or a solution thereof in sulphuric acid may be used with the same result. By
neutralising with carbonate of soda the free a-disulphonic acid of naphthylamine, or
the acids from its sodaic salts, the easily soluble neutral sodaic salt is obtained, and
if parts of the same are heated in an autoclave with one part of caustic soda and
two parts of water for a period of from 10 to 12 hours at a temperature of from 230
to 260 C., the new amido-naphthol-sulphonic acid is precipitated in a crystalline
form by the addition of mineral acids to the product of the re-action diluted in
water.
The
The relative proportions, temperatures and periods of time hereinbefore mentioned
may be varied within certain limits without having a particular influence upon the
result. The use of strong superfluous alkali and of higher temperatures will easily
cause the formation of ammonia besides dioxi-naphthaline-sulphonic acid.
combination of the amido-naphthol-sulphonic acid with diazo-benzidine in an acetic
acid or alkaline solution, is effected according to known method. The colouring
matter is precipitated from the sodaic solution by means of common salt.
Dated this 23rd day of April 1890
S. S. BROMHEAD,
97, Newgate Street, London, E.C., Patent Agent.
COMI DEI DI ECIFICATION.
The Preparation of New Sulphonic Acids for the Production of a
Blue Colouring Matter for Cotton.
I, SAMUEL SIDNEY BROMHEAD, of 97, Newgate Street, London, Patent Agent,
(communicated), 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 consists of a process for the preparation of a blue colouring matter
for cotton as hereafter explained.
When a salt of naphthionic acid preferably the very soluble sodaic salt found in
commerce is heated for some time at a temperature of from 190° to 250° C., the same
is converted into a not readily soluble salt of an isomeric acid hitherto unknown.
While the diluted solutions of this naphthionate produce an intensely violent
fluorescence the neutral solution of the new acid exhibits only a very feeble reddish
fluorescence. On adding mineral acids to the solutions of its salts the new acid
gradually separates in a contrary manner to its isomeres in the form of well shaped

page_text: crystals. Its diazo-compound crystallises in small greenish yellow scales, and is
converted by boiling with diluted sulphuric acid into a readily soluble a-naphthol-
sulphonic acid and produces a dichloro-naphthaline the melting point of which is
from 34 to 35 C.
The new acid further differs very considerably from all a-naphthylamine-sulphonic
acids owing to the important yellow tints of the azo colouring material produced
therefrom. Should the new a-naphthylamine-sulphonic acid be treated at the
ordinary temperature with fuming sulphuric acid a likewise new a-naphthylamine-
disulphonic acid will be formed which acid is not readily soluble and forms acrid
alkaline salts. Its acid as well as neutral solution produces a characteristic greenish
blue fluorescence.
By treatment with nitrite of soda in an acid solution its diazo compound is
obtained and crystallises in the form of small brilliant light yellow needles.
This a-naphthylamine-disulphonic acid differs also from the hitherto known
isomeres, by the prominent yellow tint of the azo colouring matter produced there-
from.
When the sodaic salt of this a-naphthylamine-disulphonic acid is heated for a long
time in an autoclave with soda lyes at a temperature of from 200° to 250° C. an
amidonaphthol-mono-sulphuric acid is obtained. This combined with tetrazo-
diphenyl produces in a solution of acetic acid or in an alkaline solution, a colouring
matter which gives cotton in a neutral or slightly alkaline solution a clear blue dye
without mordant.
DESCRIPTION OF THE PROCESS.
Sodaic naphthionate is heated in a boiler or cylinder, arranged longitudinally and
provided with an agitator, to a temperature of from 220° to 240° C., until its full
conversion into a salt of the new acid is effected, this being ascertained by testing
the partial insolubility of the product in water, and by finding out the disappearance
of the intense violet blue fluorescence produced by the diluted solution of the
former.
To prevent oxidation, a slow current of carbonic acid is passed through the mass.
The product of the re-action is dissolved almost without residuum in boiling water,
and can be still further purified by successive crystallisation from the same.
The process may also be carried out at a lower temperature than the above but
consumes accordingly a longer time.
The new naphthylamine-sulphonic acid is precipitated by means of sulphuric acid
from the solution of the sodaic salt thus produced, and after being dried, and
pulverized while cooled, it is gradually incorporated with four parts of fuming
sulphuric acid containing 10% of anhydride.
The solution thus produced forms a crystalline mass after it has been allowed.to
stand for several hours. This mass is mixed when cooled with two parts of water,
when the main portion of the new disulphonic acid separates in a crystalline form.
This acid is very easily soluble in water but scarcely soluble in diluted sulphuric
acid.
The remainder is obtained in the form of a sparingly soluble acid sodium salt, by
adding common salt or sulphate of soda to the filtrate.
The sparingly soluble acid alkaline salts obtained from the new disulphonic acid,
can also be produced directly by dissolving in fuming sulphuric acid the alkaline
salts of the mono-sulphonic acids instead of the free acids and by decomposing the
product with with water after the re-action is terminated.
Instead of the fuming sulphuric acid a combination of sulphuric acid mono-chlor-
hydrine, or a solution thereof in sulphuric acid may be used with the same result.
By neutralising with carbonate of soda the free a-disulphonic acid of naphthylamine,
or the acid from its sodium salt, the easily soluble neutral sodaic salt is
obtained; and if parts of the same are heated in an autoclave, with one part of
caustic soda and two parts of water, for a period of from 20 to 22 hours at a
temperature of from 230° to 260° C., the new amido-naphthol-sulphonic acid is

page_text: precipitated in a crystalline form by the addition of mineral acids to the product of
the re-action diluted in water.
The relative proportions, temperatures and periods of time hereinbefore mentioned
may be varied within certain limits without having a particular influence upon the
result. The use of superfluous alkali and of higher temperatures will easily cause
the formation of ammonia besides dioxi-naphthaline-sulphonic acid. The combination
of the amido-naphthol-sulphonic acid with diazo-benzidine in an acetic acid or
alkaline solution is effected according to known method. The colouring matter is
precipitated from the sodaic solution by means of common salt.
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 :-
1. The preparation of a new a-naphthylamine-mono-sulphonic acid by heating
salts of naphthionic acid at a temperature exceeding 190 C., as herein explained.
2. The conversion of the mono-sulphonic acid obtained according to the above
claim into a new a-naphthylamine-disulphonic acid, by treating the free acid or its
salts with fuming sulphuric acid or sulphuric acid with mono-chlorhydine, as herein
explained.
3. The preparation of a new amido-naphthol-mono-sulphonic acid, by heating with
alkalies the a-naphthylamine acid produced according to claim 2, as herein explained.
4. The preparation of a new blue colouring matter for cotton by means of a
combination of the amido-naphthol-sulphonic acid, produced according to claim 3
with tetrazo-diphenyl, as herein explained.
Dated this 21st day of January 1801
S. S. BROMHEAD,
97, Newgate Street, E.C.