Manufacture of Azo-colouring Mattere, Derivatives of the 1.4 a-naphtholsulphonic Acid, from Corresponding Azo-colouring Matters of Naphthionic Acid.
Year: 1894

page_text: · Date of Application, 21st July, 1894
⚫ Complete Specification Left, 22nd Apr., 1895-Accepted, 8th June, 1895
PROVISIONAL SPECIFICATION.
[Communicated from abroad by THE FARBWERKE, vormals MEISTER
LUCIUS AND BRUNING, of Hoechst, raf Main, in the Empire of Germany,
Manufacturers.]
.:.
:
Manufacture of Azo-colouring Mattere, Derivatives of the 1.4
a-naphtholsulphonic Acid, from Corresponding Azo-colouring
Matters of Naphthionic Acid.
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 to be as follows:-
:-
My foreign correspondents have discovered that the azo-colouring matters which
contain naphthionic acid as the second component exchange the amido group of the
naphthionic acid residue for the hydroxyl group on being heated with caustic
alkalies. This exchange takes place in most cases by simply heating with aquegus
solution of caustic potash in open vessels to from 120° to 150º C., but in a few
cases, especially in those of the tetrazo. colouring matters, which are not easily
soluble, it is necessary to employ dry caustic alkali or caustic alkali with only a
small quantity of water, in other words to proceed in the manner usual for a caustic
potash melt. Even in these last mentioned cases very low temperatures are
sufficient; almost without exception, under 200° C. The conversion takes place in
all cases very smoothly and completely.
In consequence of the above facts, the present method is a new and advantageous
way for obtaining colouring matters which are derivatives of the 1-4 a-naphthol-
sulphonic acid, because the 14 a-naphtholsulphonic acid cannot be nearly so easily
obtained from naphthionic acid as the azo-colouring matters of the former from
those of the latter.
11
la thin mathad.
Ji.

page_text: the evolution of ammonia has ceased, about 1 hour. The isolation of the azo-
orseilline" from the melt is effected according to known methods.
Dated this 21st day of Jule 1804
Manufacture of Azo-colouring Matters, Derivatives of the 14
a-naphtholsulphonic Acid, from Corresponding Azo-colouring
Matters of Naphthionio Acid.
:
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 and in what manner the same is to be performed to be particularly
described and ascertained in and by the following statement:-
My foreign correspondents have discovered that the azo colouring matters which
contain naphthionic acid as the second component exchange the amido group of the
naphthionic acid residue for the hydroxyl group on being heated with caustic
alkalies. This exchange takes place in most cases by simply heating with aqueous
solution of caustic potash in open vessels to from 120° to 150° C., but in a few
cases, especially in those of the tetrazo colouring matters which are not easily
soluble, it is necessary to employ dry caustic alkali or caustic alkali with only a
small quantity of water, in other words, to proceed in the manner usual for a caustic
potash melt. Even in these last mentioned cases very low temperatures are
sufficient, almost without exception, under 200° C. The conversion takes place in
all cases very smoothly and completely.
1
In consequence of the above facts, the present metliod is a new and advantageous
way for obtaining colouring matters which are derivatives of the 14 a-naphthol
sulphonic acid, because the 1-4 a-naphthol sulphonic acid cannot be nearly so easily
obtained from naphthionic acid as the azo colouring matters of the former from
those of the latter.
TL
11
1 "

page_text: ABEL & IMRAY,
Agents for the Applicant.