Manufacture of Cotton Dyestuffs.
Year: 1899

page_text: Date of Application, 10th Aug., 1899
Complete Specification Left, 28th Apr., 1900-Accepted, 30th June, 1900
Date of Application, 10th Aug., 1899
Complete Specification Left, 28th Apr., 1900-Accepted, 30th June, 1900
PROVISIONAL SPECIFICATION.
Manufacture of Cotton 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 & Brüning of Hoechst a/Main, in the Empire of Germany,
Chemical Manufacturers) to be as follows:-
My correspondents have invented a method for separating the compound which
is produced in the manufacture of naphthazarine as an intermediate product;
this compound has already been mentioned by Aguiar & Bayer (Ber. 4. p. 440)
and is more particularly characterised in the German Patent No. 76,922.
The present process consists in adding to the mixture obtained in making naph-
thazarine, suitably diluted, a solution of chloride of zinc. The intermediate pro-
duct is thus separated as a zinc compound.
EXAMPLE I.
200 kilos of the mixture obtained in making naphthazarine are added to 600
litres of ice water; the solution is then filtered, and 50 litres of a solution of
chloride of zinc (40° Bé. specific gravity) are added. The "naphthazarine inter-
mediate product" is thus precipitated and may then be filtered, washed with a
solution of common salt and dried; it forms a dark violet powder which is soluble
in water and alcohol; it may be crystallised from water in the form of needles.
By the action of sulphides of alkali metals upon the " naphthazarine inter-
mediate product" a dyestuff is obtained which directly dyes cotton blue-violet ;
the dyes, on subsequent treatment with metallic salts, yield remarkably power-
ful and fast black shades. The best result is obtained if the "naphthazarine inter-
mediate product as obtained above is heated with alkali polysulphides; less
powerful products are obtained by the action of sulphides of alkali metals in an
aqueous solution, or if, instead of the naphthazarine intermediate product, the
corresponding leuco-compound or naphthazarine be treated with sulphides of
alkali metals.
27
EXAMPLE 2.
HEATING THE NAPHTHAZARINE INTERMEDIATE PRODUCT WITH ALKALI
POLYSULPHIDES.
50 parts by weight of the naphthazarine intermediate product, 50 parts by
weight of sulphur and 250 parts by weight of crystallised sodium sulphide are
thoroughly mixed and heated to 150° C. for several hours till an increase in the
intensity of colour is no longer to be observed. The mass is then dissolved in
water and the solution filtered and evaporated to dryness. A dark violet powder
is obtained which is soluble with a blue colour in water, sulphides of alkali metals,
caustic alkalies or their carbonates. The solutions dye cotton blue-violet and
the dyes, on subsequent treatment with metallic salts, shew dark blue tints which
are characterised by their fastness.

page_text: 1 12
HEATING THE NAPHTHAZARINE WITH SULPHIDES OF ALKALI METALS.
50 parts by weight of naphthazarine are dissolved in a little water with 50 parts
by weight of sulphur and 250 parts by weight of sodium sulphide; the solution
is then evaporated to dryness and the residue is heated to 140° to 150° C. for
several hours.
The mass is dissolved in hot water and is then filtered. Acids precipitate
the dyestuff which is easily soluble in alkalies and sulphides of alkali metals.
The solutions dye cotton grey to blue-black tints.
Dated this 10th day of August 1899.
ABEL & IMRAY,
Agents for the Applicant.
Manufacture of Cotton 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 & Brüning of Hoechst a/Main, in the Empire of 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 correspondents have invented a method for separating the compound which
is produced in the manufacture of naphthazarine as an intermediate product;
this compound has already been mentioned by Aguiar & Bayer' (Ber. 4. p. 440)
and is more particularly characterised in the German Patent No. 76,922.
The present process consists in adding to the mixture obtained in making naph-
thazarine, suitably diluted, a solution of chloride of zinc. The intermediate
duct is thus separated as a zinc compound, that is, combined with zinc chloride.
'pro-

page_text: HEATING THE LEUCO-COMPOUND CORRESPONDING WITH THE INTERMEDIATE PRO-
DUCT WITH SULPHIDES OF ALKALI METALS.
30 parts by weight of the leuco-compound, 250 parts by weight of sodium
sulphide and 30 parts by weight of sulphur are heated together.
The mass
becomes at once of a copper-like colour, it is heated to 150° to 180° C. for some
hours. The melt is then dissolved in water and its blue-violet solution is
filtered.
Acids precipitate the dyestuff, which, when dry, is a black powder soluble

page_text: HEATING NAPHTHAZARINE WITH SULPHIDES OF ALKALI METALS.
50 parts by weight of naphthazarine are mixed with a little water with 50 parts
by weight of sulphur and 250 parts by weight of sodium sulphide; the mass
is then evaporated to dryness and the residue is heated to 140° to 150° C. for
several hours.
The mass is dissolved in hot water and is then filtered. Acids precipitate
the dyestuff which is easily soluble in alkalies and sulphides of alkali metals.
The solutions dye cotton grey to blue-black tints.
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 herein described process for separating a naphthazarine intermediate
product and manufacturing cotton dyestuffs by heating the said product, or its
leuco-compound or oxidation product or naphthazarine with alkali poly-sulphides
with or without zinc chloride.
2. The dyestuffs manufactured as above set forth.