Improvements in the Manufacture of Colouring Matters for Dyeing and Printing derived from Benzidine and its Analogües.
Year: 1891

page_text: Date of Application, 9th July, 1891
Complete Specification Left, 30th Mar.. 1892-Accepted, 30th Apr., 1892
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Colouring Matters for Dyeing
and Printing derived from Benzidine and its Analogües.
BENJAMIN WILLCOX of 47 Lincoln's Inn Fields in the County of Middlesex
Patent Agent do hereby declare the nature of this invention which has been
communicated to me from abroad by The Farbenfabriken vormals Friedrich
Bayer & Co. of Elberfeld in the Empire of Germany to be as follows:—
1
This invention relates to the manufacture of a series of valuable dye stuffs.
suitable for dyeing and printing.
My foreign correspondents employ for this purpose those intermediate products
which are obtained by combining one molecule of tetrazodiphenylchloride,
tetrazoditolylchloride tetrazophenyltolylchloride or of the tetrazochloride of
diphenoldimethylether with one molecule of an aromatic hydroxy carbon acid such
as salicylic acid, ortho cresolcarbon acid metacresolcarbon acid, resorcylic acid and
the like. By boiling in a neutral alkaline or acid solution until the disengagement
of nitrogen is finished these so called intermediate compounds are changed into
dye-stuffs which are derived from paraamidohydroxydiphenyl In order to explain
this process the following equation illustrating the formation of such colouring
matter from tetrazodiphenylchloride and salicylic acid is given by way of
example.
C₂H-OH
COOH
(Parahydroxydiphenylparaazo salicylic acid).
The last named azo compound represents merely one colouring matter amongst
the many which may be obtained by means of this invention. These azo dye-stuff's
are very valuable as they are not only capable of dyeing mordanted wool but may
also be employed in calico printing. By these two properties which are similar to
tliose of alizarine and its derivatives the new products differ distinctly from the
tetrazo dye-stuffs obtainable by the combination of one molecular proportion of
tetrazodiphenylchloride or its analogous compounds with two molecular proportions
of one of the above mentioned dye-stuff components inasmuch as the tetrazo
dye-stuff's thus formed although capable of dyeing wool in shades fast against fulling
are not applicable in calico-printing the colour not being fast to soap.
With regard to the production of these azo colouring matters the following is
given as an example illustrating in a general way the production of dyestuffs.
according to this invention the parts being by weight..

page_text: .
COLOURING MATTER FROM TETRAZODIPHENYLCHLORIDE AND SALICYLIC
ACID IN MOLECULAR PROPORTIONS.
=
10 parts of benzidine are dissolved in 500 paits of water and 28 parts of
muriatic acid (20° Baumé) this solution is then diazotised with 7.5 parts of sodium
nitrite dissolved in about 50 parts of water maintained at a low temperature by
ice. The diazo solution is allowed to flow slowly into an icy cold liquid'
containing 8-2 parts of salicylic acid and 15 parts of sodium carbonate dissolved
in 500 parts of water. After standing for about four hours the formation of the
intermediate product is completed the said product being dissolved in the alkaline
solution as a sodium salt. By the addition of diluted sulphuric acid in slight excess.
it is separated and thereafter is filtered off. Without having been dried it is
suspended in 2000 parts of water acidulated with 40 parts of sulphuric acid
nt 66° Baumé with constant stirring it is to be heated for some hours upon a water
bath till the disengagement of nitrogen is finished. The separated precipitate
after having been filtered off is washed out in order to remove the sulphuric acid.
The paste thus obtained containing the colouring matter parahydroxydiphenyl-
paraazo salicylic acid may be employed directly for dyeing and printing the shades
produced thereby are yellow with a reddish hue.
As with regard to the analogous dye-stuffs formed according to this invention
the most valuable are those which contain tetrazodiphenyl or the following
compounds tetrazoditolyl, tetrazophenyltolyl or tetrazodiphenoldimethyl ether and
as second component salicylic acid, ortho or meta cresolcarbon acid 1.35
dihydroxybenzoic acid alpha or beta naphthoic acid. The various shades of these
colouring matters are generally yellow, with a red or brown hue.
Dated this 8th day of July 1891.
J. H. JOHNSON & Co.,
47, Lincoln's Inn Fields, London, Agents.
COMPLETE SPECIFICATION.
Improvements in the Manufacture of Colouring Matters for Dyeing
and Printing derived from Benzidine and its Analogues.
I BENJAMIN WILLCOX of 47 Lincoln's Inn Fields in the County of Middlesex,
Patent Agent do hereby declare the nature of this iuvention (which has been
communicated to me from abroad by The Farbenfabriken vormals Friedrich Bayer
& Co. of Elberfeld in the Empire of Germany) and in what manner the same is
to be performed to be particularly described and ascertained in and by the
following statenient :--
This invention relates to the manufacture of a series of valuable dye-stuffs
suitable for dyeing and printing.
My foreign correspondents employ for this purpose the intermediate products
obtained by combining one molecular proportion of tetrazo diphenylchloride. tetrazo
ditolylchloride, tetrazo phenyltolylchloride, or the tetrazo chloride of diphenol-
dimethylether, with one molecular proportion of an aromatic hydroxy carboxylic
acid such as salicylic acid, ortho cresolcarboxylic acid, metacresol carboxylic acid,
resorcylic acid, and the like. By boiling such intermediate products in a neutral
alkaline or acid solution until the disengagement of nitrogen is at an end they are
changed into dye-stuffs derived from para amido hydroxydiphenyl:

page_text: In order to explain this process the following equation, illustrating the formation
of such a colouring-matter from tetrazodiphenylchloride and salicylic acid is given :.
OH
C¸H₁—N=N—C¸H¸
+N
COOH
C,H-OH
(Para hydroxy diphenyl para azo salicylic acid).
The last named azo compound is representative of but one amongst the many
colouring matters which may be obtained by means of this invention.
These azo dye-stuffs are very valuable as they are not only capable of dyeing
mordanted wool but may also be employed in calico-printing. In possessing these
two propertics (in which respect they resemble alizarin and its derivatives) the new
products distinctly differ from the tetrazo-dye-stuffs obtainable by the combination.
of one molecular proportion of tetrazo diphenylchloride or its analogues, with two
molecular proportions of one of the above mentioned dye-stuff components in as
Duch as the tetrazo dye stuffs thus formed although capable of dyeing wool shades
which withstand fulling, are not applicable in calico-printing the colours they afford
being affected by soap.
With regard to the production of these azo-colouring-matters the following is
given as an example illustrating, in a general way, the production of dye stuffs.
according to this invention. The parts are by weight :-
COLOURING-MATTER FROM TETRAZODIPHENYL-CHLORIDE AND SALICYLIC
ACID IN MOLECULAR PROPORTIONS.
10 parts of benzidine are dissolved in 500 parts of water and 28 parts of muriatic
acid (20° Baume) aud the resulting solution kept at a low temperature by adding
ice is diazotised with 76 parts of sodium uitrite dissolved in about 50 parts of
water. The diazo-solution so obtained is allowed to flow slowly into an icy cold
liquid containing 75 parts of salicylic acid and 15 parts of sodium carbonate
dissolved in 500 parts of water. The formation of the intermediate product is.
completed in about four hours the said product being dissolved in the alkaline
solution as a sodium salt. It is separated by adding dilute sulphuric acid in slight
excess and is subsequently filtered off, and the undried substance is suspended in
2000 parts of water, acidulated with 40 parts of sulphuric acid at 66 degrees
Baume. The resulting mixture is constantly stirred while heated for some liours
upon a water bath till disengagement of nitrogen no longer takes place. The
separated precipitate having been filtered off is washed in order to remove the
sulphuric acid. The paste thus obtained containing the colouring-matter para
hydroxy diphenyl para azo salicylic acid having the formula hereinbefore given
may be directly employed for dyeing and printing. The shades produced thereby
are yellow with a reddish hue.
With regard to the analogous dye-stuffs formed according to this invention the
most valuable are those which contain tetrazo diphenyl or the following compounds:
tetrazo ditolyl, tetrazo-phenyltolyl, or tetrazo diphenol dimethylether and as second

page_text: component salicylic acid, ortho- or meta cresol carboxylic acid, symmetrical
1.35 dihydroxy benzoic acid, alpha- or beta- naphthoic acid. The shades of these
various colouring-matters are generally yellow with a red or brown hue.
Having now particularly described and' ascertained the nature of this said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. The production of new colouring-matters suitable for dyeing and printing by
combining one molecular proportion of tetrazo diphenyl-chloride, tetrazo ditolyl-
chloride, tetrazo phenyl-tolylchloride, or the tetrazo chloride of diphenolether with
one molecular proportion of an aromatic hydroxycarboxylic acid and subsequently
heating the resulting intermediate products in neutral, alkaline, or acid solutions
until the disengagement of nitrogen is at an end.
2. The new products having the properties above described and produced by the
hereinbefore described process or by any other method producing a like result with
the exception however of the dye-stuff parahydroxy diphenyl para azo salicylic
acid which is already described in the German Patent No. 52661 dated 16th June
1888.
1
J. H. JOHNSON & Co.,
47, Lincoln's Inn Fields, London, W.C., Agents.
J. H. JOHNSON & Co.,
47, Lincoln's Inn Fields, London, W.C., Agents.