Manufacture of Blue and Black Sulphurised Dyestuffs.
Year: 1898

page_text: Date of Application, 21st Nov., 1898
Complete Specification Left, 21st Aug., 1899-Accepted, 30th Sept., 1899
PROVISIONAL SPECIFICATION.
Manufacture of Blue and Black Sulphurised Dyestuffs.
I, OLIVER IMRAY, of Birkbeck Bank Chambers, Southampton Buildings, in the
County of London, Chartered Patent Agent, do hereby declare the nature of this
invention (as communicated to me from abroad by The Farbwerke vormals Meister
Lucius and Brüning, of Hoechst a/Main, Germany, Chemical Manufacturers,) to
be as follows
My foreign correspondents have found that by heating para-substituted diphenyl-
amine-mono- or disulphonic acids with sulphur and sodium sulphide, blue to black
dyestuffs may be obtained.
Among such acids may be mentioned diamido diphenylamine-mono-sulphonic
acid described in the German Patent No. 86,250 as well as the oxyamidodiphenyl-
amine-sulphonic acid and the diamido-diphenylamine-disulphonic acid, which have
not hitherto been described. These latter acids are obtained as follows; 260 parts.
by weight of para-nitro-chlorobenzene, 110 parts by weight of para-amidophenol
and 136 parts by weight of sodium acetate in 1,000 parts by weight of water are
heated for 6 to 8 hours on the water-bath, when first oxynitrodiphenylamine-
sulphonic acid is formed, which, on the liquid being acidified, separates as a yellow
precipitate soluble with difficulty in water. This separation, however, is not
necessary for the further treatment, as the solution thus obtained, may be reduced
directly, best with iron. After reducing, the liquid is made alkaline with soda,
filtered to separate the iron mud and acidified; the oxyamidodiphenylamine-
sulphonic acid separates as a crystalline mass which is insoluble in water.
To manufacture diamidodiphenylamine-disulphonic acid, 200 parts by weight of
para-nitrochlorobenzene-sulphonic acid, 50 parts by weight of para-phenylene-diamine-
sulphonic acid,, 100 parts by weight of soda and 1,000 parts by weight of water are
boiled in a vessel provided with an inverted condenser for about 6 hours; the
resulting brown-yellow solution is acidified with hydrochloric acid, when the aшnido-
nitrodiphenylaminedisulphonic acid separates as a thick grey-yellow precipitate; it is
filtered, pressed and reduced in the usual manner, for instance, with iron and acetic
acid. After having made the liquid of reduction alkaline with soda, and filtered off
the iron, the diamido-disulphonic acid is precipitated with hydrochloric acid; it.
separates as a greyish-white crystalline precipitate; it is soluble with difficulty in
water.
Dyestuffs are obtained from the above mentioned substances heated with sulphur
and sodium sulphide, as follows:-
1 part by weight of oxyamido-diphenylaminesulphonic acid is heated with one
part by weight of sulphur and 5 parts by weight of sodium sulphide to 180° to
200° C., until the mass, after an active evolution of hydrogen sulphide, becomes
solid and dry. This product may be employed directly for dyeing; it is a porous,
black mass, easily soluble in water with a green colour and dyes cotton a pale green.
The green tint, however, turns slowly when exposed to air, and rapidly when treated
with chromates, or better still with persulphate or peroxide of hydrogen, to a deep
blue. On allowing the aqueous solution of the product to stand for some time, the

page_text: green colour first becomes red and brown and afterwards a beautiful blue. The same
effect, only more rapid, is obtained by introducing air or treating with oxidising
agents, such, for instance, as a persulphate. The dyestuff, therefore, is to every
appearance contained in the product as leuco-compound. To obtain the blue dye-
stuff, the blue solution is acidified, when the dyestuff separates in blue flakes; it is
filtered, redissolved in soda and salted out with common salt. The dyestuff is in the
form of a dark blue powder of coppery lustre, easily soluble in water to a blue solution
and can be reprecipitated from the solution by means of acids.
Instead of oxyamidodiphenylaminesulphonic acid, the unreduced nitro-acid may
also be employed.
If the mixture be heated for a longer time and at a higher temperature such
as 240° C, then by subsequent oxidation, dyestuffs of a darker shade up to deep
black are obtained.
Dated the 21st day of November 1900
ABEL & IMRAY,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Manufacture of Blue and Black Sulphurised Dyestuffs.
I, OLIVER IMRAY, of Birkbeck Bank Chambers, Southampton Buildings, in the
County of London, Chartered Patent Agent, do hereby declare the nature of this
invention (as communicated to me from abroad by The Farbwerke vormals
Meister Lucius and Brüning, of Hoechst a/Main, Germany, Chemical Manufacturers,)
and in what manner the same is to be performed to be particularly described and
ascertained in and by the following statement :-
My foreign correspondents have found that by heating para-substituted diphenyl-
aminesulphonic acids with sulphur and sulphides of alkali metals to 200° C., dye-
stuff's directly dyeing cotton blue may be obtained. Of all acids tried hitherto in
this direction para-oxy-para-amidodiphenylamine-ortho-sulphonic acid
110 parts by weight of para-amidophenol, 136 parts by weight of sodium acetate in
1000 parts by weight of water are heated for 6 to 8 hours on the water-bath; oxy-
nitrodiphenylaminesulphonic acid is first produced, which when the liquid is acidified
separates as a yellow precipitate soluble with difficulty in water.
This separation
however, is not necessary for the further working as the solution obtained may be
reduced directly, best by iron. After the reduction, the liquid is made alkaline with
soda, filtered to separate the iron mud and acidified; the oxyamidodiphenylamine-
sulphonic acid separates in the form of a crystalline mass which is soluble with
difficulty in water.

page_text: EXAMPLE.
To a melted mixture of 100 parts by weight of sodium sulphide and 40 parts by
weight of sulphur are added 30 parts by weight of para-oxy-para-ainidodiphenylamine-
sulphonic acid and the whole is heated to 160° to 200° C., until the mass, after an
active evolution of hydrogen sulphide, becomes solid. On cooling there remains a
dark porous mass which is easily soluble in water and dyes cotton a pale green.
The dyes, however, become blue when dried and exposed to the air, or when
treated with oxidising agents. The dyestuff, therefore, is contained in the product as
leuco-compound and the solution has first to be oxidised so as to obtain the dyestuff.
This is done best by introducing a blast of air, but other oxidising agents may also
be used, such as peroxide of hydrogen, for instance. After oxidation the dyestuff is
filtered from the sulphur and precipitated by adding common salt. When dry, it is
in the form of a dark brown powder of coppery lustre, easily soluble in water to a blue
coloured solution; acids precipitate it from its solutions. If the mass obtained
at 160° to 200° be further heated, for instance for another 3 hours to 200°
to 240° C. an evolution of gas again takes place and a black porous mass is finally
obtained which is soluble in water with a grey black colour directly dyeing cotton
black.
Instead of oxyamidodiphenylaminesulphonic acid the oxynitrodiphenylamine-
sulphonic acid may be employed.
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 :-
1. The herein described manufacture of a blue sulphurised dyestuff from para-oxy-
para-amidodiphenylamine-ortho-sulphonic acid or para-oxy-para-nitrodiphenylamine-
ortho-sulphonic acid by heating said acid with sulphur and a sulphide of an alkali
metal to about 160° to 200° C. and by treating the mass thus obtained with oxidising
agents in an aqueous solution.
2. The herein described manufacture of a black sulphurised dyestuff by further
heating the mass obtained as set forth in Claim 1 to from 200° to about 240° C.
3. The blue and black dyestuffs manufactured as above set forth.
Dated this 21st day of Anonst. 1899
ABEL & IMRAY,
Agents for the Applicant.