Process for Discharging Para Nitraniline Red Fabrics White and Coloured, and Manufacture of a Discharging Colour therefor.
Year: 1896

page_text: Date of Application, 27th Apr., 1896
Complete Specification Left, 25th Jan.. 1897-Accepted, 27th Mar., 1897
PROVISIONAL SPECIFICATION
[Communicated from abroad by THE FARBWERKE, vormals MEISTER LUCIUS &
BRUNING, of Hocchst n/Main, in the Empire of Germany, Chemical
Manufacturers.]
Process for Discharging Para Nitraniline Red Fabrics White and
Coloured, and Manufacture of a Discharging Colour therefor.
I, OLIVER IMRAY, of No. 28 Southampton Buildings, Chancery Lane, in tho
County of London, Chartered Patent Agent, do hereby declare the nature of this
invention to be as follows:-
Of the insoluble azn-dyes hitherto produced the so called "para mitraniline red"
has been largely employed in printing and dyeing on account of its fastness and
brilliant tints.
In those cases in which brilliancy of colour, simplicity of method and a low
price, together with fastness, are essential, the para-nitraniline red may be
substituted in many instances for alizarine red, if sufficiently fast, thus largely
reducing the application of the direct red cotton dyestuffs.
In many cases, however, a preference still exists for the latter dyestuffs as being
more easily discharged. Hitherto it has been impossible to discharge thoroughly
white the insoluble azo dyes produced on the fibre, and for the so called "discharging
articles" had to be substituted the resisting style, which again had this disadvantage
of not producing a pure and always equally good discharging white nor to produce
coloured discharges fast to soap.
My foreign correspondents have found that para nitraniline red may be easily
discharged in white and even in colours, if to the discharging colour containing tin
salt, such as has hitherto been used, substances are added, which dissolve the para
Ditraniline red.
The red, transitorily dissolved in steam, is thus easily reduced by the tin salt into
its products of reduction, paraphenylene diamine and amido-naphthol which may
be easily removed by subsequent washing. By means of appropriate concentration
and composition of the discharging colours, the formation of hydrocellulose and
consequently the corrosion of the cotton fibre can be avoided. As substances best
suited for these purposes, may be mentioned, glycerine, acetine, chlorhydrine, aud
glyceride of other equally fixed organic acids or mixed acids like tartracetine &c.,
laevuline acid, and alcohols not readily volatilisable and their esters.
The process is as follows:-
A tin salt discharging colour is printed on para nitraniline red which contains
50 to 150 grs. of one of the above mentioned solvents as well as acetates and
citrates of ammonium or of the alkalies to ensure against corrosion of the fibre,
also thickening such as wheaten starch, dextrine and guin. After printing and
dyeing, the fabric is steamed for about 10 minutes aud passed through hot water,
well washed and then the printed stuffs are passed through a slightly acid and
strongly diluted solution of bleaching powder. Drying with chlorine on the cans
serves the same purpose.
This operation of treating with chlorine is not intended to clean the parts
discharged with white, but to vivify and reproduce the red colour if it should

page_text: appear brown through steaming; the original beauty of the red is again obtained
after the treatment with chlorine.
By the addition of dyestuffs which easily sustain the action of discharges and
which under the present conditions are easily fixed, (such as Persian berries with
or without addition of aniline colours &c.) it is not difficult to obtain coloured
discharges; they can likewise be produced by previously preparing the fabric
with tannin and printing thereupon the aniline dyestuffs mixed with tin salt
discharges or by printing thereupon tannin colours mixed with a discharging
agent.
A further advantage resulting from the application of para nitraniline red is
that the described white, and coloured discharges reduce sufficiently so as to avoid
the formation of the over printed aniline black without damaging the purity of
the red discharges and preserve white and other coloured patterns pure under
souspassement or under-printing of black.
It is evident that the white or coloured discharges permit at the same time the
printing of aniline black, the latter being easily composed so as to become fixed
under the same conditions of steaming.
Dated this 27th day of April 1806
ABEL & IMRAY,
Agents for the Applicant.
Process for Discharging Para Nitraniline Red Fabrics White and
Coloured, and Manufacture of a Discharging Colour therefor.
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:-
Of the insoluble azo-dyes hitherto produced the so called "para nitraniline red"
has been largely employed in printing and dyeing on account of its fastuess and
brilliant tints.
In those cases in which brilliancy of colour, simplicity of method and a low
price, together with fastness, are essential, the para-nitraniline red may be
substituted in many instauces for alizarine red, if sufficiently fast, thus largely
'reducing the application of the direct red cotton dyestuffs.
In many cases, however, a preference still exists for the latter dyestuffs as being
more easily discharged. Hitherto it has been impossible to discharge thoroughly
white the insoluble azo dyes produced on the fibre, and for the so called
"discharging articles" had to be substituted the resisting style, which again had
this disadvantage of not producing a pure and always equally good discharging
white nor to produce coloured discharges fast to soap.
My foreign correspondents have found that para nitraniline red may be easily
discharged in white and even in colours, if to the discharging colour containing
tin salt, such as has hitherto been used, substances are added, which dissolve the
para nitraniline red.
The red, transitorily dissolved in steam, is thus easily reduced by the tin salt
into its products of reduction, parapheuylene diamine and amido-naphthol which
may be easily removed by subsequent washing.
By means of appropriate coucentration and composition of the discharging
colours, the formation of hydrocellulose and consequently the corrosion of the
cotton fibre can be avoided. As substances best suited for these purposes, may be

page_text: mentioned, glycerine, ncetine, chlorhydrine, and glyceride of other equally fixed
organic acids or mixed acids like tartracetine &c., laevuline acid, and alcohols not
readily volatilisable, and their esters.
The process is as follows:-
A tin salt discharging colour is printed on para uitraniline red which contains
50 to 150 grs. per litre of one of the above mentioned solvents as well as acetates
and citrates of ammonium or of the alkalies to ensure against corrosion of the
fibre, also thickening such as wheaten starch, dextrine and gum.
Alter printing and dyeing, the fabric is steamed for about 10 minutes and passed
through hot water, well washed and then the printed stuffs are passed through a
slightly acid and strongly diluted solution of bleaching powder. Drying with
chlorine on the cans serves the same purpose.
This operation of treating with chlorine is not intended to clean the parts
discharged with white, but to vivify and reproduce the red colour if it should
appear brown through steaming; the original beauty of the red is again obtained
after the treatment with chlorine.
By the addition of dyestuffs which easily sustain the action of discharges and
which under the present couditions are easily fixed, (such as Persian berries with
or without addition of aniline colours &c.) it is not difficult to obtain coloured
discharges; they can likewise be produced by previously preparing the fabric with
tanniu and printing thereupon the aniline dyestuffs nixed with tin salt discharges
or by printing thereupon tannin colours mixed with a discharging agent.
A further advantage resulting from the application of para nitraniline red is
that the described white and coloured discharges reduce sufficiently so as to avoid
the formation of the over printed aniline black without damaging the purity of the
red discharges and preserve white and other coloured patterns pure under
souspassement or under-printing of black.
It is evident that the white or coloured discharges permit at the same time the
printing of aniline black, the latter being easily composed so as to becoine fixed
under the same conditions of steaming.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. Process for discharging paranitraniline red consisting in printing upon the
same with discharging colours containing tin salt and substances having a dissolving
action upon the red and allowing the discharge to act in the usual manner by
steaming substantially as described.
2. As new product the herein described discharge for paranitraniline red
containing besides tin salt substances which exercise a dissolving action on the
paranitrapiline red.
Dad his wish dana af tanna1802
ABEL & IMRAY,
Agents for the Applicant.