The Manufacture and Production of New Cotton or Substantive Dye-stuffs.
Year: 1891

page_text: Date of Application, 4th Nov., 1891
Complete Specification Left, 26th July, 1892-Accepted, 27th Aug., 1892
PROVISIONAL SPECIFICATION.
The Manufacture and Production of New Cotton or Substantive
Dye-stuffs.
I BENJAMIN WILLCOX of 47 Lincolns Inn Fields in the County of Middlesex
Patent Agent. do hereby declare the nature of this invention which has been
communicated to me from abroad by the Farbenfabriken vormals Friedrich Bayer
& Co. of Elberfeld in the Empire of Germany to be as follows :-
In the Specification of the French Patent No. 209519 dated November 14th
1890 Messieurs Guinon Picard and Gay have described a process for converting
the colouring matters primuline polychromine and the like by treatment with
hypochlorites into new products suitable for dyeing.
The compounds thus made use of are dyes possessing considerable affinity for
vegetable fibre. My foreign correspondents have found that the sulpho acids of the
products which are obtained by melting para-toluidine, meta-xylidine or 4-cumidine
with sulphur and which according to the researches of Gattermann and Pfitzinger
(see Berichte der Deutschen Chemischen Gesellschaft volume XXII page 1063)
are derivatives of benzenyl-ortho-amido-thio-meta-cresol
=
can be transformed into dye-stuffs of high value by the same reagent (sodium
hypochlorite) although the sodium salts of the said sulpho acids which are
employed in my foreign correspondents' process are colourless and are destitute of
affinity to vegetable fibres.
The dye-stuffs obtained from the said sulpho acids are by far superior in colouring
power and purity of their shades to those which are produced according to the said
French Patent No. 209519.
The following is given as an example of the manufacture of a yellow colouring
matter from the sulpho acid of dehydro paratoluidine melting at 191 degrees
centigrade.
50 kilos of dehydro-thio-paratoluidine sulpho acid are dissolved in 1000 litres of
water together with from eight to ten kilos of sodium carbonate. The solution is
then mixed at a temperature of about 10 to 15 degrees centigrade with a watery
solution of sodium hypochlorite in water obtained by adding the requisite quantity
of sodium carbonate to 50 kilos of chloride of lime (bleaching-powder). The fluid
which is at first colourless and exhibits only a slight violet fluorescence first turns
gray and then becomes of a deeper and deeper reddish-yellow colour. The reaction
is complete after about 24 hours.
The dye-stuff is precipitated by the addition of common salt, filtered off and
washed with a solution of common salt until the adherent sodium hypochlorite is
removed. The precipitate is dried.
The dyestuff thus obtained forms a brown powder easily soluble in water and
produces on unmordanted wool a brilliant yellow colour (similar to that produced
by chrysamine R) which will withstand alkalies, acids, chlorine and light.
This new product probably belongs to the series of azo or azoxy colouring
matters. It is apparently produced from two molecules of dehydrothioparatoluidine
sulpho acid by the simultaneous oxidation of two amido groups into an azo or azoxy
group, as my foreign correspondents have found that the dye-stuff which is obtained
by operating in accordance with the above example that is to say by oxidising

page_text: dehydro-thio-paratolnidine sulpho acid is no longer diazotable and therefore does
not contain an amido group.
The analogous products which result when the sulpho acids of dehydrothio-
xylidine or dehydro-thio-cumidine are oxidised with sodium hypochloride in the
before described manner yield yellow shades differing from those of the toluidine
derivative by their reddish hue.
Dated thi ith day of Nimemhan 1001
J. H. JOHNSON & Co.,
47, Lincoln's Inn Fields, Agents.
COMPLETE SPECIFICATION.
The Manufacture and Production of New Cotton or Substantive
Dye-stuffs.
I BENJAMIN WILLCOX of 47 Lincolns Inn Fields in the County of Middlesex
Patent Agent do hereby declare the nature of this invention (which has been
communicated to me from abroad by the Farbenfabriken vormals Friedrich Bayer
& Co. of Elberfeld in the Empire of Germany) 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 of the French Patent No. 209519 dated Novr. 14th 1890
Messrs. Guinon Picard and Jay have described a process for converting, the
colouring matters primuline, polychromine and the like by treatment with hypo-
chlorites into new products suitable for dyeing. The compounds thus made use of
are dyes possessing considerable affinity for vegetable fibres.
My foreign correspondents have found that the sulpho acids of the products
which are obtained by melting para-toluidine, meta-xylidine or -cumidine with
sulphur and which according to the researches of Gattermann and Pfitzinger (see
Berichte der Deutschen Chemischen Gesellschaft volume XXII page 1063) are
derivatives of benzenyl-ortho-amido-thio-meta-cresol
=
CH, C, H,
S
C - C, H,
N.
can be transformed into dyestuffs of high value by the same reagent (sodium 30
hypochlorite) or analogous oxidising agents although the sodium salts of the said...
sulpho acids which are employed in my foreign correspondents' process. are
colourless and are destitute of affinity to vegetable fibres.
The dyestuffs obtained from the said sulpho acids are far superior in colouring..
power and purity of their shades to those which are produced according to the.said: 36
French Patent No. 209519.
The following is given as an example of the manufacture of a yellow. colouring...
matter from the sulpho acid of dehydrothioparatoluidine melting at 191 degrees..
centigrade.
50 kilos of dehydro-thio-paratoluidine sulpho acid are dissolved in 1000 litres of 40
water together with from eight to ten. kilos of sodium carbonate. The solution is
then mixed at a temperature of about 10 to 15 degrees centigrade. with a watery,
solution of sodium hypochlorite obtained by adding the requisite quantity of sodium..
carbonate to 50 kilos of chloride of lime (bleaching powder). The fluid which is
at first: colourless and exhibits only a slight violet fluorescence first turns.dull.grey. 4
and then becomes of a deeper and deeper reddish-yellow colour. The reaction is..
complete after about 24 hours.
The dye stuff is. precipitated by the addition of common salt,. filtered off. and..
washed with a watery solution of common salt until the adherent. sodium. hypo-.
chlorite is removed. The precipitate is then dried...
50
The dye-stuff thus obtained is a brown powder which is readily soluble.in.water..

page_text: and produces on unmordanted cotton a brilliant yellow colour (similar to that
produced by chrysamine R) which will withstand alkalies, acids, chlorine and
light.
This new product and the corresponding dye-stuffs from dehydrothiometaxylidine
and dehydrothio-4-cumidine sulpho acid probably belong to the series of azo- or
azoxy colouring-matters. The colouring-matter of the foregoing example is
apparently produced from two molecules of dehydrothio paratoluidine sulpho acid
by the simultaneous oxidation of two amido groups into an azo or azoxy group as
my foreign correspondents have found that the dye-stuff which is obtained by
operating in accordance with the above example that is to say by oxidising
dehydrothioparatoluidine sulpho acid is no longer diazotisable and therefore does
not contain an amido group.
The analogous products which result when the sulpho acids of dehydrothio-
xylidine or dehydrothiocumidine are oxidised with sodium hypochlorite in the
hereinbefore described manner yield yellow shades differing from those of the
toluidine derivative by their reddish-hue.
Instead of hypochlorites also hypobromites or other oxidising agents such as for
example potassium ferricyanide or lead dioxide and the like in the presence of
alkalies can be employed.
All colouring-matters thus obtained withstand the action of alkalies, acids,
chlorine and light. They are also by far superior to the dye-stuff's described in the
said French Patent No. 209519 by reason of their greater colouring power and the
purity of their shades.
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 process of preparing new cotton or substantive dye-stuffs by acting with
oxidising agents such as hypochlorites, hypobromites or potassium ferricyanide,
lead dioxide and the like in the presence of alkalies, on the sulpho acids of
debydrothio-paratoluidine, dehydrothio-meta-xylidine and dehydrothio-4-cumidine.
2. As new manufactures the new colouring-matters having the properties as
hereinbefore described.
Dated this 26th day of July 1800
J. H. JOHNSON & Co.,
47, Lincoln's Inn Fields, Agents.