Manufacture of Dyestuffs of the Triphenylmethane Series fast to Alkali.
Year: 1897

page_text: Date of Application, 12th July, 1897
Complete Specification Left, 4th Apr., 1898-Accepted, 28th May, 1898
PROVISIONAL SPECIFICATION.
Manufacture of Dyestuffs of the Triphenylmethane Series fast to
Alkali.
I, OLIVER IMRAY, of No. 28, Southampton Buildings, Chancery Lane, in the
County of London, Chartered Patent Agent, do hereby declare the nature of this
invention (which has been communicated to me from abroad by The Farbwerke
vormals Meister Lucius and Brünning of Hoechst a/ Main in the Empire of
Germany, Chemical Manufacturers) to be as follows:-
My foreign correspondents have found that valuable green to blue dyestuffs may
be obtained from meta-oxysulphonic acids of the benzene or naphthalene series
having the general formula
10 parts by weight of tetra-methyl-p-diamidobenzhydrol and 8 parts of
m-methoxybenzene sulphonate of sodium are dissolved, whilst being stirred and
cooled, in 6 times the quantity of concentrated sulphuric acid. After a few hours
the whole is poured on ice and from the resulting aqueous solution the leuco-
sulphonic acid is separated by addition of soda and sodium acetate, in form of a
white product which is filtered and dried.
The leucosulphonic acid is dissolved in diluted sulphuric acid to which is gradually
the calculated quantity of a 10% peroxide of lead paste. The blue solution is then
filtered, the sulphuric acid is precipitated with lime and the filtrate is evaporated,

page_text: The pulverized residue is then mixed with 5 times the quantity of fuming sulphuric
acid of 20% and on the sulphonation being completed the dyestuff is isolated in the
usual way.
It forms a brilliant copper-coloured mass, easily soluble in water with
a bluish-green colour, dyeing wool green and having the fast properties of the
"Patent Blue."
EXAMPLE II.
7.5 parts by weight of tetramethyldiamidobenzhydrol and 10 parts of the sodium
salt of 1.3.8 methoxynaphthalenedisulphonic acid are digested with 60 parts of
concentrated sulphuric acid until complete solution, care being taken to avoid a rise
of the temperature. The whole after being left to itself for a few hours, is poured
on ice and having neutralized with lime, the leucosulphonic acid thus obtained in
the form of its calcium salt is isolated whilst the sulphuric acid is separated in form
of calcium sulphate and the remaining solution is evaporated. In order to oxidise,
10 parts by weight of the calcium salt are dissolved in 300 parts of water to which
is added the calculated quantity of diluted sulphuric acid and peroxide of lead. The
greenish-blue solution thus obtained is filtered and evaporated. The dyestuff is
obtained as a brilliant copper red mass, soluble in water with a greenish-blue
colour; it dyes wool greenish-blue in an acid bath and is fast to alkali.
Dated this 12th day of July 1897.
ABEL & IMRAY,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Manufacture of Dyestuffs of the Triphenylmethane Series fast to
Alkali.
I, OLIVER IMRAY, of Birkbeck Bank Chambers, Southampton Buildings, but
formerly of 28, Southampton Buildings, Chancery Lane, in the County of London,
Chartered Patent Agent, do hereby declare the nature of this invention (which
has been communicated to me from abroad by The Farbwerke vormals Meister
Lucius and Brünning of Hoechst a/ Main, in the Empire of Germany, Chemical
Manufacturers) and in what manner the same is to be performed to be par-
ticularly described and ascertained in and by the following statement:-
My foreign correspondents have found that valuable green to blue dyestuffs may
be obtained from meta-oxysulphonic acids of the benzene or naphthalene series
having the general formula:-

page_text: The easily soluble calcium salt of the leucosulphonic acid, obtained by evaporation
of the solution filtered from sulphate of lime, may be oxidised by dissolving 10 parts
by weight of this salt in about 300 parts of water and treating it with the calculated
quantity of dilute sulphuric acid and peroxide of lead paste of 10 %, whereupon it
is filtered from the lead-sulphate and the dyestuff solution is evaporated to dryness.
The dyestuff forms a brilliant substance of dark copper colour soluble in water with
a green tint. It dyes wool in an acid bath a green shade fast to alkali.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. The herein described manufacture of green to blue-green triphenylmethane-
dyestuffs, by condensing meta-alkyloxysulphonic acids with tetra alkyl-para-
diamidobenzhydrols, oxidising the leuco-compounds thus formed, and, when they
are monosulphonic acids, sulphonating them before or after oxidation.
2. The colouring matters of the constitution :-