Improvements in the Preparation of Colouring Matters for Cotton.
Year: 1897

page_text: Improvements in the Preparation of Colouring Matters for Cotton.
We, ARTHUR GEORGE GREEN, F.I.C., F.C.S., of 13, King's Drive, Heaton Moor, near
Stockport, in the County of Lancaster, and ANDRÉ RAOUL WAHL, of 331, Ashton
New Road, Clayton, near Manchester, in the said County, both Chemists to the
Clayton Aniline Company Limited, do hereby declare the nature of our invention to
be as follows:-
The present invention relates to the preparation from di-nitro-diphenyl-ethylene
di-sulphonic acid [4: 2:1] NO, (SOH) CH¸ · CH. CH. C₂H, (SO,H) NO, [1:2:4]
(the production of which is the subject of our application for Letters Patent
No. 5351 of 1897) of a series of colouring matters of which some are new and some
probably identical with colours which may be obtained in other ways. We have
found that the said substance can be converted into colouring matters by the following
four methods of treatment:
A. By reduction.
-
B. By condensation with phenols and amines.
C. By condensation and reduction.
D. From certain of the products obtained according to A, B, and C, by
diazotisation and coupling with phenols and amines.
The colouring matters obtained by either of these methods have a direct affinity for
unmordanted cotton which they dye in a great variety of shades varying from yellow
and orange to red, dark brown, and black.
A. CONVERSION BY REDUCTION.
By the action of weak reducing agents (preferably in alkaline solution) upon
dinitrodiphenylethylene disulphonic acid it is converted into yellow and orange
colouring-matters which are probably identical with the colours obtained by the
combined action of caustic alkalies and oxidisable substances upon paranitrotoluene
sulphonic acid. But when more powerful alkaline reducing agents react upon dinitro-
diphenylethylene disulphonic acid as for instance sodium amalgam the final
product is diamido-diphenylethane disulphonic acid. On the other hand when strong
acid reducing agents are employed diamidodiphenylethylene disulphonic acid is
obtained as described in the Provisional Specification of the above mentioned
application for Letters Patent No. 5351. Suitable reducing agents are zinc dust,
ferrous bydrate, sodium stannite, lead glucose, glycerine, benzaldehyde, and the like,
but we do not confine ourselves to these as any substance may be used which is
capable of taking up oxygen without itself undergoing condensation. When the
reduction is performed in the cold a red unstable intermediate product is generally
first produced which seems to be identical with the red intermediate product of the
action of caustic alkalies upon paranitrotoluene sulphonic acid.

page_text: a blue solution. Thus the further the reduction is carried the redder is the shade
which the product dyes and the bluer is its solution in sulphuric acid.
EXAMPLE 2.
50 lbs. of dinitrodiphenylethylene disulphonate of soda are dissolved in 50 gallons
of water and 5 gallons of aqueous caustic soda (30% NaOH) and 25 lbs. of glycerine
are added thereto. The mixture is heated to from 70° to 80° centigrade until the
formation of colour ceases. The separated colour is then filtered off and dried. It
dyes yellowish orange on cotton and dissolves in sulphuric acid with a reddish-violet
colour.
B. CONVERSION BY CONDENSATION WITH PHENOLS AND AMINES.
When dinitrodiphenylethylene disulphonic acid is heated in the presence of
caustic alkalies with amines phenols, amidophenols, nitro amines, or their sulphonic
or carboxylic acid derivatives, either of the benzene or of the naphthalene series, a
condensation takes place and colouring-matters are produced which dye unmor-
danted cotton. This condensation takes place in some cases in the proportion of 1
molecule of dinitrodiphenylethylene disulphonic acid to 1 molecule of the reacting
substance, in other cases either with molecule or with 2 molecules of the
reacting substance. In some instances a marked difference in properties is obser-
vable according to the proportions in which the reaction takes place whilst in others
there is but a slight difference. Amongst the amido compounds which are particu-
larly suitable for this reaction we mention especially dehydrothiotoluidine sulphonic
acid primuline and other dehydrothio compounds. These bodies give rise to
valuable yellow colouring-matters which are very similar in properties and are per-
haps identical with the compounds obtained according to the Specification of Letters
Patent No. 12922 of 1896 granted to us. The colouring-matters which result when
the reacting substance is a diamine, phenol, amidophenol, or oxycarboxylic, acid, con-
tain, in general, a free amido group and are hence diazotisable either in substance, or
upon the fibre. By combination of these diazotised colours with the usual azo-dye-
stuff components or "developers" a large range of colouring matters result some of
which are distinguished by great fastness. On the other hand the condensation pro-
ducts resulting when the reacting substance is a monamine or amidosulphonic acid do
not as a rule contain an amido group and are therefore incapable of diazotisation.

page_text: dyes orange on unmordanted cotton and this can be diazotised upon the fibre and
gives, with developers, various shades of red, brown and grey. If in the above
example 42 lbs. instead of 21 lbs. of paraphenylene diamine be used, a product is
obtained which dissolves in concentrated sulphuric acid forming a reddish violet
solution, and in water forming an orange solution from which a trace of acid throws
it down in blue flocks. Like the preceding product it dyes orange on cotton and is
diazotisable.

page_text: water. 5 gallons of aqueous caustic soda (30% NaOH) are added and 50 gallons of a
10% solution of glucose are run in. The mixture is boiled for some time and the
product is then salted out, filtered off and dried. It is a dark powder which dissolves
in concentrated sulphuric acid forming a blue solution. It dyes orange on cotton and
can be diazotised and developed upon the fibre.

page_text: precipitated by salt. It is a dark coloured powder soluble in concentrated sulphuric
acid forming a violet-blue solution. It dyes brown on unmordanted cotton.
The above examples are given to illustrate the general method of carrying out this
invention but we do not limit ourselves to the exact conditions and proportions
therein given as these may be varied greatly.
By the action of weak reducing agents (preferably in alkaline solution) upon
dinitrodiphenylethylene disulphonic acid, it is converted into yellow and orange
colouring-matters.
If on the other hand more powerful alkaline reducing agents react upon dinitro-
diphenylethylene disulphonic acid, as, for instance, sodium amalgam, the final product
is diamidodiphenylethane disulphonic acid, and when strong acid reducing agents
are employed diamidodiphenylethylene disulphonic acid is obtained as described in
the Specification of the above mentioned Letters Patent 535197.
Suitable reducing agents for the production of the above mentioned colouring-
matters are zinc dust, ferrous hydrate, sodium stannite, lead, glucose, glycerine,
benzaldehyde, and the like, but we do not confine ourselves to these.

page_text: solution of glucose are then added, and the mixture is heated to 70° Centigrade for
from 3 to 4 hours. The excess of caustic soda is then neutralised by acid and the
precipitated colouring matter is filtered off and dried. It dyes yellow on cotton and
dissolves in concentrated sulphuric acid forming an orange solution. If instead of
15 gallons of 10 % glucose solution 30 gallons be employed the colour obtained dyes
orange on cotton and dissolves in concentrated sulphuric acid forming a violet solu-
tion. If 45 gallons of 10 % glucose be employed the colouring matter obtained
dyes a redder orange on cotton and dissolves in concentrated sulphuric acid forming
a blue solution. Thus the further the reduction is carried the redder is the shade
which the product dyes and the bluer is its solution in sulphuric acid.
When dinitrodiphenylethylene-disulphonic acid is heated in the presence of caustic
alkalies with amines, phenols, amidophenols, nitroamines, or their sulphonic, or
carboxylic, acid derivatives, either of the benzene, or of the naphthalene, series, a
condensation takes place and colouring-matters are produced which dye unmordanted
cotton. This condensation takes place, in some cases, in the proportion of one
molecule of dinitrodiphenylethylene disulphonic acid to one molecule of the
reacting substance, in other cases either with one molecule or with two molecules
of the reacting substance. In some instances a marked difference in properties is
observable according to the proportions in which the reaction takes place, whilst in
others there is but a slight difference. Amongst the amido compounds which are
particularly suitable for this reaction we mention especially dehydrothiotoluidine
sulphonic acid, primuline, and other dehydrothio compounds, which give rise to
valuable yellow dyestuffs.
"
The colouring-matters which result when the reacting substance is a diamine,
phenol, amidophenol, or oxy carboxylic, acid, contain, in general, a free amido group
and are hence diazotisable either in substance, or upon the fibre. By combination of
these diazotised colours with the usual azo-dyestuff components, or developers," a
large range of further colouring matters results. On the other hand the condensa-
tion-products resulting when the reacting substance is a monoamine, or
amidosulphonic acid, do not, as a rule, contain an amido group, and are therefore
incapable of diazotisation.
EXAMPLE 3.
100 lbs. of dinitrodiphenylethylene-disulphonate of soda and 21. lbs. of parapheny-
lene diamine are dissolved in 50 gallons of water. 10 gallons of aqueous-caustic soda
(30 % Na OH) are then added and the mixture is boiled for about 8 hours. The
colour is dissolved in water and precipitated by means of common salt. When dried
it is a dark powder with metallic reflex, soluble in water forming an orange. solution
from which a trace of hydrochloric acid throws down a reddish-violet precipitate, It
dissolves in concentrated sulphuric acid forming a blue solution. It dyes orange on
unmordanted cotton and this can be diazotised upon the fibre and gives, with
developers, various shades of red, brown and grey. If, in the above example, 42.lbs.
instead of 21 lbs. of paraphenylene-diamine.be, used, a product is obtained which
dissolves in concentrated sulphuric acid forming a reddish-violet solution, and in

page_text: 50 lbs. of the colouring-matter obtained according to the preceding Example 4 from
dinitrodiphenylethylene disulphonic acid and salicylic acid are dissolved in 100 gallons
of water, 5 gallons of aqueous caustic soda (30% NaOH) are added and 50 gallons of
a 10% solution of glucose are run in. The mixture is boiled for some time and the
product is then salted out, filtered off and dried. It is a dark powder which dissolves
in concentrated sulphuric acid forming a blue solution. It dyes orange on cotton
and can be diazotised and developed upon the fibre.

page_text: 50 lbs. of the colour obtained according to the preceding Example 4 by condensing
dinitrodiphenylethylene disulphonic acid with salicylic acid, are dissolved in
100 gallons of water and acidified with 5 gallons of hydrochloric acid (30%). The
mixture is cooled and diazotised by the addition of 3 gallons of sodium nitrite
solution containing 6.9% NaNO. A solution of 12 lbs. of amido-naphthol-disul-
phonic acid H is then added together with sufficient sodium carbonate to keep the
mixture alkaline. The combination is completed by heating to 40° to 50° Centigrade,
and the product is precipitated by salt. It is a dark coloured, powder soluble in
concentrated sulphuric acid forming a violet-blue solution. It dyes brown
unmordanted cotton.
on
The above examples are given to illustrate the general method of carrying out this
invention but we do not limit ourselves to the exact conditions and proportions
herein given as these may be varied greatly.

page_text: Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed we declare that what
we claim is:-
1. The herein before described process for the production of yellow to orange
colouring-matters from the dinitrodiphenylethylene-disulphonic acid of Letters
Patent 5351 of 1897 by limited reduction in alkaline solution.
2. The hereinbefore described process for the production of yellow, orange or
brown colouring-matters from the dinitrodiphenylethylenedisulphonic acid of
Letters Patent 5351 of 1897 by condensation in alkaline solution with aromatic
amines, diamines, phenols, amidophenols, nitramines, or their sulphonic, or
carboxylic, acids.
3. The herein before described process for the conversion of the colouring-matters
obtained according to the preceding claims into colouring-matters of redder shade by
limited reduction in alkaline solution.
4. The herein before described process for the conversion of such of the colouring-
matters obtained according to the preceding Claims 2 and 3 as contain a free amido
group, into further colouring-matters of darker shade by diazotisation and coupling
with the usual azo-dyestuff components, whether in substance, or upon the fibre,
or by the employment of the diazo compound as one constituent of a mixed
polyazo-colour.
5. The process described in the foregoing Example 6 for the preparation of a
yellow colouring-matter by condensation of dinitrodiphenylethylenedisulphonic acid
of Letters Patent 5351 of 1897 with dehydrothiotoluidine sulphonic acid in caustic
alkaline solution.
6. The process described in the foregoing Example 8 for the preparation of an
orange colouring-matter by the action of an alkaline reducing agent upon the
product of the preceding Claim 5.
7. As new products the direct dyeing cotton colouring-matters such as are obtained
according to the processes of the foregoing Claims 1, 2, 3, 4, 5 and 6, with exception
of those which are identical with the products of known processes.
Dated this 18th day of July 1040
Dated this 18th day of Tuly 1948
JOHNSONS & WILLCOX,
47, Lincoln's Inn Fields, London, W.C., Agents.
ly 10
1048
JOHNSONS & WILLCOX,
47, Lincoln's Inn Fields, London, W.C., Agents.