Improvements in the Manufacture of Red Direct Cotton Colouring Matters.
Year: 1894

page_text: Date of Application, 12th Nov., 1894
Complete Specification Left, 12th Aug., 1895-Accepted, 14th Sept., 1895
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Red Direct Cotton Colouring
Matters.
We, ARTHUR GEORGE GREEN F.C.S., F.I.C., of 13 Kings Drive, Heaton
Moor, Stockport, and ROBERT JANSEN Ph.D., of 16 The Grove, Victoria Park,
Manchester, Chemists to The Clayton Aniline Cc. Ld., Aniline Dye Manufacturers
of Clayton in the County of Lancaster, do hereby declare the nature of our
invention to be as follows:-
In English Patent 17333 of 1888 the production of bluish red colouring matters
is described by the combination of the diazo compounds of dehydrothiotoluidine
or of dehydrothioxylidine with the alpha naphthol--disulphonic acid. The colors
so obtained dye unmordanted cotton bluish red and have the valuable property of
being very resistant to alkalies and light. It has been subsequently shown that
this property is due to the meta position of one of the HSO, groups to the
OH group in the naphthalene nucleus. We have now found that colors possessing
similar valuable properties but which dye cotton yellower shades of red than the
above may be obtained by employing the lower homologue of dehydrothiotoluidine
(here termed provisionally dehydrothioaniline) in combination with such derivatives
of naphthalene as contain an HSO3 group in the meta position to an alpha OH group
and are otherwise suitable for the purpose. Such components are alpha
naphthol-m-sulphonic acid and certain of its amido-, oxy-, sulpho-, chloro-, and
alkyloxy derivatives, of which the following may be especially mentioned :-

page_text: solution of 7 lbs. of sodium nitrite is slowly added until a clear solution of the
diazo compound is obtained. The latter is then added to a solution containing :-
30 lbs. of the sodium salt of a-naphtol-a-disulphonic acid and
20 lbs. of dry sodium carbonate in 30 gallons of water.
--
The precinitated color is filtered off and dried It does cotton. a bright red
Improvements in the Manufacture of Red Direct Cotton Colouring
Matters.
We, ARTHUR GEORGE GREEN, and ROBERT JANSEN, both of Clayton,
Manchester, Chemists, 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 English Patent 17333 of 1888 the production of bluish-red colouring matters
is described by the combination of the diazo compounds of dehydrothiotoluidine
or of dehydrothioxylidine, with the alpha-naphthol epsilon-disulphonic acid. The
colours so obtained dye unmordanted cotton bluish-red and have the property of
being very resistant to alkalis and light. It has been subsequently shewn that this
property is due to the meta position of one of the HSO, groups to the OH group
in the naphthalene nucleus. We have now found that colours possessing similar
valuable properties, (but which dye cotton shades of red yellower than those dyed
by the above) may be obtained by employing the lower homologue of dehydro-
thiotoluidine (which may be termed dehydrothioaniline) in combination with such
derivatives of naphthalene as contain an HSOs group in the meta position to an
alpha OH group and are otherwise suitable for the purpose. Such components
are alpha-naphthol meta-sulphonic acid and certain of its amido-, oxy-, sulpho-,
chloro- and alkyloxy derivatives of which the following may be specially
mentioned -
0
Alpha-naphthol-meta-sulphonic acid-₁H (OH) (SOH) [1:3]
Alpha-naphthol-epsilon-disulphonic-acid-C₁,H, (OH) (SO,H), [1:3:8]
Chloro-alpha-naphthol-disulphonic-acid-C₁,H. (OH) (Cl) (SO,H), [1: 8:3:6]
Amidonaphthol-sulphonic acid-C₁H, (OH) (NH2) (SO,H) [1:8:3]
Amidonaphthol disulphonic acid H-C₁H. (OH) (NH) (SO,H), [1:8:3:6]
Amidonaphthol sulphonic acid-C₁H, (OH) (NH2) (SO₂H) [1:6:3]
Amidonaphthol disulphonic acid-С₁H (OH) (NH₂) (SO₂H), [1:6:3:5]
Dioxynaphthalene disulphonic acid-C₁,H. (OH), (SO,H), [1:8:3:6]
30 4
10 4
The dehydrothioaniline is obtained according to the method of French
Patent 216086 by heating a mixture of one molecular proportion of paratoluidine
and rather more than one molecular proportion of aniline with sulphur (4 atoms)
until the evolution of hydric sulphide ceases. The product after distillation and
crystallisation from amylalcohol forms smill yellow prismatic crystals which melt
constantly at 151° Centigrade (the melting point is given as 154° Centigrade in

page_text: the above French Patent). It is moreover distinguished from the dehydrothio-
toluidine by the ready solubility of the ammonium salt of its mono sulphonic
acid.
The following instance is given as illustrating the general method of carrying
out our invention but we do not limit ourselves to the details of this example.
22 lbs. of dehydrothioaniline are finely suspended in 3 gallons of hydrochloric acid
(30 per cent. HCI) and 20 gallons of water. The mixture is cooled with ice and a
solution of 7 lbs. of sodium nitrite is slowly added until a clear solution of the
diazo compound is obtained.
The latter is then added to a solution containing 30 lbs. of the sodium salt of
alpha-naphthol-epsilon-di-sulphonic acid and 20 lbs. of dry sodium carbonate in
30 gallons of water. The precipitated colour is filtered off and dried. It dyes
cotton a bright red from an alkaline or salt bath.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed we declare that what we
claim is :-
1. The manufacture of red direct cotton colouring matters by combining
dehydrothioaniline with such derivatives of naphthalene as are hereinbefore
defined.
2. The manufacture of red direct cotton colouring matters according to the
example hereinbefore given.
3. As new articles of manufacture, the colouring matters produced by the
process hereinbefore stated, or by any other process affording the same result.
Dated this 12th day of August.
JOHNSONS &
LLCOX,
47 Lincoln's Inn Fields, London, W.C., Agents.