Manufacture of Green Colouring Matters for Dyeing Wool.
Year: 1898

page_text: Date of Application, 31st Jan, 1898
Complete Specification eft. 29th Oct.. 1898-Accepted, 14th Jun., 1899
L
PROVISIONAL SPECIFICATION.
Manufacture of Green Colouring Matters for Dyeing Wool.
I, Dr. HUGO WEIL, Chemist, in Basle, Switzerland, do hereby declare the nature
of this invention to be as follows:-
Although it seems evident that p-nitro-benzaldehyde-ortho-sulphonic acid should
lend itself to the production of colouring matters of the malachite green series; till
now such colouring matters derived from it have not been known. By my researches
on the colouring matters derived from p-nitro-benzaldehyde-o-sulphonic acid, 'by
condensing one molecule of it. with two molecules of ethyl- or methyl-benzylaniline
sulphonic acid or with two molecules of ethyl- or methyl-benzylaniline and sulphona-
ting the two benzyl groups, and oxidising the resulting leuco compound as is done
for example in the ordinary acid-green-process, it has been been ascertained that the
tri-sulphonated colouring matters thus obtained are of little intensity and of inferior
technical value.
I have now found that colouring matters of great intensity and of in high degree;
fast to washing and milling, and to alkalies, are obtained, if the colouring matters
derived from p-nitro-benzaldehyde-o-sulphonic acid and ethyl or methyl-benzyl-
aniline are constituted in coin pliance with the following conditions:-
(1) The presence of no more than two sulpho-groups in the molecule.
(2) The presence of two benzyl groups in the molecule.
(3) Only one of the two benzyl groups should be sulphonated.
Such new colouring matters are obtained by the oxidation of the disulphonated
leuco-compounds produced as follows :-
(1) By condensing para-nitro-benzaldehyde-ortho-sulphonic acid with two molecules
of ethyl or methyl-benzylaniline, carefully sulphonating the product with sulphuric
acid to introduce one sulpho-group, separating the formed disulpho-compound by
pouring the mixture into water, and filtering from the solution of dilute sulphurie
acid and of any easily soluble trisulpho-acid which may have been formed.
(2) By condensing one molecule of para-nitro-benzaldehyde sulphonic acid in the
presence of alcohol with the mixture of one molecule of ethyl- or methyl-benzylaniline
sulphonic acid and one molecule of ethyl- or methyl-benzylaniline dissolving, the
condensation product in a dilute solution of carbonate of soda or acetate of, soda, and.:
separating the leuco-disulpho-acid from the filtered solution by addition of dilute
sulphuric acid.
Under these conditions a small quantity of leuco-trisulpho-acid, which may have"
been formed, remains in the solution.
EXAMPLE.
117
25 parts by weight of sodium para-nitro-benzaldehyde-orthosulphonate is heated-
and continuously stirred with 40 parts of ethyl benzylaniline or methyl benzylaniline..
and 50 parts of dilute sulphuric acid of 30% strength at 110° C. until the amine has
disappeared. The aqueous solution is separated from the solid. leuco-monosulpho
said which is than mushed with a amall

page_text: 15 parts of this product are introduced in 100 parts of monohydrated sulphuric acid
or sulphuric acid containing free sulphuric anhydride in the cold, and after complete
dissolution the liquid is heated in the water bath until a portion dissolves completely
in dilute soda lye.
The whole mixture is then poured into 500 parts of ice water and the precipitate
filtered and washed with a little water on the filter, for dissolving a small quantity of
trisulpho-acid which has been formed. The residual leuco-disulpho-acid thus
obtained is then dried.
24 parts of the leuco-disulpho-acid thus obtained are dissolved in 3-5 parts of a
soda lye of 10% and 55 parts of water, acidified with 3.3 parts of sulphuric acid of
10 % at an elevated temperature. 1.8 parts of lead peroxide (paste of 45 %) are
introduced.
The oxidation immediately takes place, the resulting solution of the colouring
matter is filtered and evaporated, or the colour precipitated with common salt. It
forms in the dry state a dark powder with bronze lustre easily soluble in water with
a green coloration, which is not changed by addition of dilute mineral acids, dilute
alkalies and ammonia.
It produces on wool in an acid bath a green shade of great fastness to alkalies and
to milling. The solution in concentrated sulphuric acid is yellow, and turns to green
by addition of a great quantity of water.
The nitro benzaldehyde ortho-sulpho-acid used may be prepared by oxidation of
paradinitrostilbeneortho-disulpho acid or of paradinitrosostilbene disulpho acid with
permanganate of potassium, or by transforming the mononitrated ortho-chlorbenzyl-
chloride into nitro-orthochlor-benzaldehyde and transforming the resulting nitro-
orthochlor-benzaldehyde into nitro-benzaldehyde ortho sulpho acid by the action of
sulphite of sodium in the known manner.
If instead of para-nitro benzaldehyde sulpho-acid, para-chlor benzaldehyde ortho-
sulpho-acid (derived from para-diamidostilbene ortho disulpho acid, by replacing the
amido groups by chlorine and oxidizing the para-dichlorstilbene ortho disulpho acid
thus obtained with permanganate of potassium) be employed, new colouring matters
of a more bluish shade, but of the same valuable properties (fastness to washing,
milling and alkalies) are obtained.
Dated this 31st day of January 1898.
ABEL & IMRAY,
Agents for the Applicant
Manufacture of Green Colouring Matters for Dyeing Wool.
I, Dr. HUGO WEIL, Chemist, in Basle, Switzerland, do bereby declare the nature
of this invention and in what manner the same is to be performed to he particularly
described and ascertained in and by the following statement :-
Although it seems evident that p-nitro-benzaldehyde-ortho-sulphonic acid should
lend itself to the production of colouring matters of the malachite green series, till
now such colouring matters derived from it have not been known. By my researches
on the colouring matters derived from p-nitro-benzaldehyde-o-sulphonic acid, by
condensing one molecule of it, with two molecules of ethyl- or methyl-benzylaniline
sulphonic acid or with two molecules of ethyl- or methyl-benzylaniline and
sulphonating the two benzyl groups, and oxidising the resulting leuco-compound as
is done for example in the ordinary acid-green process, it has been ascertained that
the tri-sulphonated colouring matters thus obtained are of little intensity and of
inferior technical value.

page_text: I have now found that colouring inatters of great intensity and in high degree
fast to washing, milling and alkalies, are obtained, if the colouring matters derived
from p-nitro-benzaldehyde-o-sulphonic acid and ethyl- or methyl-benzylaniline are
constituted in compliance with the following conditions:-
(1) The presence of no more than two sulpho-groups in the molecule.
(2) The presence of two benzyl groups in the inolecule.
(3) Only one of the two benzyl groups should be sulphonated.
Such new colouring matters are obtained by the oxidation of the disulphonated
leuco-compounds produced as follows:-
(1) By condensing para-nitro-benzaldehyde-ortho-sulphonic acid with two molecular
proportions of ethyl- or methyl-benzyl-aniline, carefully sulphonating the product
with sulphuric acid to introduce one sulpho-group, separating the disulphonic com-
pound thus produced by pouring the mixture into water, and filtering from the
solution of dilute sulphuric acid and of any easily soluble trisulphonic acid which may
have been formed.
(2) By condensing one molecular proportion of para-nitro-benzaldehydesulphonic
acid in the presence of alcohol with the mixture of one molecular proportion of ethyl-
or methyl-benzylaniline-sulphonic acid and one molecular proportion of ethyl- or
methyl-benzylaniline dissolving the condensation product in a dilute solution of
carbonate of soda or acetate of soda, and separating the leuco-disulphonic acid from
the filtered solution by addition of dilute sulphuric acid.
Under these conditions a small quantity of leuco-trisulphonic acid which may have
been formed, remains in the solution.
EXAMPLE.
25 parts by weight of sodium para-nitro-benzaldehyde-orthosulphonate are heated
and continuously stirred with 40 parts of ethyl-benzylaniline or methyl-benzylaniline
and 50 parts of dilute sulphuric acid of 30 per cent. strength at 110° C. until the
amine has disappeared. The aqueous solution is separated from the solid leuco-mono-
sulphonic acid which is then washed with a small quantity of water, dried and
pulverised.
15 parts of this product are introduced into 100 parts of monohydrated sulphuric
acid, or sulphuric acid containing free sulphuric anhydride, in the cold, and after
complete dissolution the liquid is heated in the water bath until a portion dissolves
completely in dilute soda lye.
The whole mixture is then poured into 500 parts of ice water and the precipitate
filtered and washed with a little water on the filter, for dissolving a small quantity of
trisulphonic acid which has been formed. The residual leuco-disulphonic acid thus
obtained is then dried. 2-4 parts of the leuco-disulphonic acid thus obtained are
dissolved in 3-5 parts of a soda lye of 10 per cent. strength and 55 parts of
water, acidified with 3-3 parts of sulphuric acid of 10 per cent. strength at an elevated
temperature and 18 parts of paste containing 45% of lead peroxide are intro-
duced.
The oxidation immediately takes place, the resulting solution of the colouring
matter is filtered and evaporated, or the colour precipitated with common salt.
It forms in the dry state a dark powder with bronze lustre easily soluble in water
with a green colouration, which is not changed by addition of dilute mineral
acids, dilute alkalies and ammonia.
It produces on wool in an acid bath a green shade of great fastness to alkalies
and to milling. The solution in concentrated sulphuric acid is yellow, and turns
to green by addition of a large quantity of water.
The nitrobenzaldehyde-ortho-sulphonic acid used may be prepared by oxidation
of paradinitrostilbeneorthodisulphonic acid or of paradinitrosostilbene orthodisul-
phonic acid with potassium permanganate, or by transforming the mononitrated
ortho-chlorobenzylchloride, into nitro-orthochlorobenzaldehyde and transforming the
resulting nitro-orthochlorobenzaldehyde into nitrobenzaldehyde-ortho-sulphonic acid
by the action of sodium sulphite in the known manner.

page_text: If instead of. para-nitrobenzaldehyde-sulphonic acid, parachlorobenzaldehyde-ortho-
sulphonic acid (derived from para-diamidostilbene-orthodisulphonic acid by replacing
the amido-groups by chlorine and oxidizing the paradichlorostilbene-orthodisulphonic
acid thus obtained with potassium permanganate) be employed, new colouring
matters of a more bluish shade, but of the same valuable properties (fastness to
washing, milling and alkalies) are obtained.
Having now particularly described and ascertained the nature of this
invention and in what manner the same is to be performed, I declare that what
I claim is :-
1: The herein described manufacture of leuco-disulphonic acids of the malachite
green series by reacting upon one molecular proportion of paranitrobenzaldehyde-
ortho-sulphonic acid or of parachlorobenzaldehyde-orthosulphonic acid with two
molecular proportions of ethylbenzylaniline or of methylbenzylaniline, introducing
into the compound thus obtained a second sulphonic acid group by sulphonation, and
precipitating the disulphonic acid by pouring the mixture into water.
2. The herein described manufacture of leuco-disulphonic acids of the malachite
green series by reacting upon one molecular proportion of päranitrobenzaldehyde-
ortho-sulphonic acid or of parachlorobenzaldehyde-orthosulphonic acid with one
molecular proportion of ethylbenzylaniline or of methylbenzylaniline and one
molecular proportion of ethylbenzylanilinesulphonic acid or of methyl-benzyl-
anilinesulphonic acid and separating the disulphonic acid thus produced by treating
the product with a solution of sodium carbonate or of sodium acetate, filtering
the solution and adding dilute sulphuric acid to precipitate the disulphonic acid.
3. The herein described manufacture of green colouring matters for dyeing wool by
reacting upon paran trobenzaldehyde-orthosulphonic acid or parachlorobenzaldehyde-
orthosulphonic acid in the manner referred to in Clain 1) or in the manner referred
to in Claim 2) and oxidising the leuco-disulphonic acids thus obtained by lead
peroxide or another suitable oxidising agent.
4. The products obtained in the manner herein set forth.