Improvements in Dyeing Cotton Without Previous Mordanting.
Year: 1899

page_text: Date of Application, 1st July, 1899
Complete Specification Left, 23rd Mar., 1900-Accepted, 28th Apr., 1900
PROVISIONAL SPECIFICATION.
Improvements in Dyeing Cotton Without Previous Mordanting.
I, OLIVER IMRAY, of Birkbeck Bank Chambers, Southampton Buildings, in
the County of London, Chartered Patent Agent, do hereby declare the nature of
this invention (as communicated to me from abroad by The Farbwerke vormals;
Meister Lucius & Brüning, of Hoechst "/Main, in the Empire of Germany,
Chemical Manufacturers) to be as follows:-
Many experiments have been made in alizarin dyeing, both in dyeing red, as
well as Bordeaux, lilac, and similar tints, to avoid the previous mordant-
ing and subsequent fixing of the mordant in dyeing yarns and tissues, by adding
mordant salts and preferably salts of organic acids to the dyestuffs in the dye-bath
and then dyeing in the usual manner. These experiments, however, have not
been successful hitherto as the results depend on the capacity to dissociate of the
salts employed. Salts, which do not dissociate at all or only slowly, such as those
of oxalic acid, citric acid &c., produce no results; the salts of laevulinic acid,
phthalic acid, acetic acid &c. dissociate with formation of basic salts & give prac-
tical results, but they are so imperfect and the materials are so expensive that
the old method of previous mordanting had to be again adopted.
My foreign correspondents have found that the salts of the cheap formic acid,
characterised by its low molecular weight, easily decompose in the dye bath
into metallic oxide and free, very volatile acid, giving excellent results in every
respect. The dyes obtained with alizarin according to the new method, the red
produced with aluminium, as well as the Bordeaux obtained with chromium and
the lilac produced with iron, are far more beautiful and even than those obtained
hitherto by the method of previously mordanting the fibre. It is particularly
important that inorganic acids be excluded as much as possible in the dyeing
process, as through their presence the beauty of the colours suffers greatly. The
properties of fastness are the same as those of new-red.
The dyeing process is as follows.
A bath is prepared with the dyestuff, the formate and the requisite lime-water
or calcium salt; then the oiled fibre is introduced, the bath slowly raised to the
boil, while the goods are well manipulated, the boiling is continued for some time
and the goods are steamed.
EXAMPLE I.
For 100 kilos. of cotton yarn to be dyed turkey-red are requisite:-
15 kilos of turkey-red oil of 50 per cent. strength,
15-25 litres of formate of aluminium of 15° Bé. specific gravity,
1-3 litres of acetate of lime solution of 18° Bé. specific gravity,
7-10 kilos. of alizarin of 20 per cent. strength.
Grounding with turkey-red oil is done as usual and the goods are then dried.
The varn is then introduced into the dye-bath containing the calculated quan-
tity of formate of aluminium, acetate of lime and alizarin, manipulated for ½ of
ID 031

page_text: an hour in the cold, heated within 1 hour to the boil, rinsed, steamed and soa
or brightened as usual.
EXAMPLE II.
For 100 kilos. of cotton yarn to be dyed Bordeaux-red are requisite:-
15 kilos of turkey-red oil of 50 per cent. strength,
15-25 litres of formate of chromium of 15° Bé. specific gravity,
1-3 litres acetate of lime of 18°. Bé. specific gravity,
7-10 kilos. of alizarin of 20 per cent. strength.
Grounding and dyeing is done in the usual manner as indicated for red.
Improvements in Dyeing Cotton Without Previous Mordanting.
I, OLIVER IMRAY, of Birkbeck Bank Chambers, Southampton Buildings, in
the County of London, Chartered Patent Agent, do hereby declare the nature of
this invention (as communicated to me from abroad by The Farbwerke vormals;
Meister Lucius & Brüning, of Hoechst "/Main, in the Empire of Germany,
Chemical Manufacturers), and in what manner the same is to be performed, to
be particularly described and ascertained in and by the following statement :-
Many experiments have been made in alizarin dyeing, both in dyeing red, as
well as Bordeaux, lilac, blue and similar tints, to avoid the previous mordant-
ing and subsequent fixing of the mordant in dyeing yarns and tissues, by adding
mordant salts and preferably salts of organic acids to the dyestuffs in the dye-bath
and then dyeing in the usual manner. These experiments, however, have not
been successful hitherto as the results depend on the capacity to dissociate of the
salts employed. Salts, which do not dissociate at all or only slowly, such as those
of oxalic acid, citric acid &c., produce no results; the salts of laevulinic acid,
phthalic acid, acetic acid &c. dissociate with formation of basic salts and give prac-
tical results, but they are so imperfect and the materials are so expensive that
the old method of previous mordanting had to be again adopted.
My foreign correspondents have found that the salts of the cheap formic acid,
characterised by its low molecular weight, easily decompose in the dye bath
in contact with oiled fibre into metallic oxide and free, very volatile acid, giving
excellent results in every respect. The dyes obtained with alizarine dyestuffs
according to the new method, the red produced with aluminium, the Bordeaux
obtained with chromium and the lilac and prune shades produced with iron salts
or mixtures, as well as the colours which may be obtained with the so-called
variegated alizarines (yellow, orange, brown, garnet, maroon, blue etc.) are
far more beautiful and even than those obtained hitherto by the method of pre-
viously mordanting the fibre. It is particularly important that inorganic acids
be excluded as much as possible in the dyeing process, as through their presence
the beauty of the colours suffers greatly.
The previous oiling of the goods or the manner in which the oil requisite for
the formation of the lake is fixed on the fibre is, to a certain extent, of import-
ance for the success of the process. If the oil or part of it be too lightly fixed,
80 as to come off in the dyebath before the fixing of the metallic salts is com-
plete, then the greater part of the lake does not form on the fibre, but in the
dyebath itself, the goods appearing uneven, irregularly dyed and more liable to
lose, colour when rubbed. The best results, therefore, have been obtained with

page_text: 32
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roods oiled in the manner usual for so-called "old-red or mixed process."
Turkey red oils containing soluble sodium salts or an excess of sodium, yield bad
results, whilst ammonia-oils yield good results.
The dyeing process is as follows.
A bath at ordinary temperature is prepared with the dyestuff, the formate and
the requisite lime-water or calcium salt; then the oiled fibre is introduced, the
bath slowly raised to the boil, while the goods are well manipulated, the boiling
is continued for some time and the goods are steamed.
EXAMPLE I.
For 100 kilos. of cotton yarn to be dyed turkey-red are requisite:-
15 kilos of turkey-red oil of 50 per cent. strength,
15-25 litres of formate of aluminium solution, of 15° Bé. specific gravity.
1-3 litres of acetate of lime solution of 18° Bé. specific gravity,
-10 kilos. of alizarin of 20 per cent. strength.
Grounding with turkey-red oil is done as usual and the goods are then dried.
The yarn is then introduced into the dye-bath containing the calculated quan-
tity of formate of aluminium, acetate of lime and alizarin, manipulated for % of
an hour in the cold, heated within 1 hour to the boil, rinsed, steamed and soaped
or brightened as usual.
EXAMPLE II.
For 100 kilos. of cotton yarn to be dyed Bordeaux-red are requisite ;-
15 kilos of turkey-red oil of 50 per cent. strength,
15-25 litres of formate of chromium of 15° Bé. specific gravity,
1-3 litres acetate of lime of 18°. Bé. specific gravity.
710 kilos. of alizarin of 20 per cent. strength,
Grounding and dyeing is done in the usual manner as indicated for red.
XAMPLE III.
For 100 kilos of loose cotion are requisite:-
15 kilos. of turkey-red oil of 50 per cent. strength,
25-30 litres of formate of chromium solution of 150° Bé. specific gravity,
3-5 kilos. of alizarine-blue SB.
The material is oiled, submitted to centrifugal action, dried and then dyed in
a vessel or dyeing apparatus at a temperature raised to boiling point, rinsed and
steamed.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is
The herein described improvement in dyeing vegetable fibres with alizarine dye-
stuffs, which consists in dyeing the fibre, prepared with oil in the usual manner
without special mordanting and fixing operations, in a single bath containing,
besides the dyestuff, formate of aluminium of chromium or of iron.
SI 1000
ABEL & IMRAY,
Agents of the Applicant.