IMPROVE- MENTS IN DYEING."
Year: 1881

page_text: LETTERS PATENT to William Edward Gaine, of Glendale, Rivercourt Road,
Hammersmith, in the County of Middlesex, for an Invention of "IMPROVE-
MENTS IN DYEING."
PROVISIONAL SPECIFICATION left by the said William Edward Gaine at
the Office of the Commissioners of Patents on the 28th June 1881.
WILLIAM EDWARD GAINE, of Glendale, Rivercourt Road, Hammersmith, in the
County of Middlesex. " IMPROVEMENTS IN DYEING."
This Invention has for its object improvements in dyeing.
When dyeing black it is usual to employ tannin and a salt of iron.
The tannin
is thrown down in the fabric by an alkali and afterward is acted on by sulphate of
iron. But under these conditions the dye color is not rapidly formed even at a
boiling temperature.
According to this Invention the tannin is dissolved with an alkaline salt, say,
for example, sodic chloride, and the fabric is prepared with this solution; it is then
passed into sulphate of iron and afterwards exposed to the action of an alkali.
Under these conditions the action in the iron solution is rapid, and by the alkali
the color is intensified and permanently fixed. The color is perfected by boiling
again in the sulphate of iron solution. By repeating the operation any depth of
color may be obtained.
If the goods be dried after exposure to the tannin and salt solution before being
brought into contact with the solution of sulphate of iron scarcely any coloration
of the solution takes place, the dye being thrown down insoluble in the goods, and
in the final washing little passes off but the surplus iron to color the water.
Or the fabric may be prepared with sulphate of iron and the oxide thrown
down in the fabric by an alkali; then the dyeing is with the tannin and salt
solution. If ferri- or ferro-cyanide of iron be added to the tannin solution a deep
blue is obtained in the fabric.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William Edward Gaine in the Great Seal Patent Office on the
28th December 1881.
WILLIAM EDWARD GAINE, of Glendale, Rivercourt Road, Hanmersmith, in the
County of Middlesex. "IMPROVEMENTS IN DYEING."
This Invention has for its object improvements in dyeing, and relates especially
to dyeing blacks and blue blacks, such as navy blue, when tannin and sulphate of
iron are employed. Together with the tannin I use the salt of an alkali or alkaline
earth. I use also ammonia or other alkali and sulphate of iron, as hereinafter
described.
In using alkaline salts as mordants in the dyeing it will be found in practice
that the best results will be obtained from the salts of nitrate of ammonia, nitrate
of soda, nitrate of potash, sulphate of ammonia, sulphite of ammonia, sulphate of
soda and potash; the muriates (as sodic chloride) are good but do not give such
satisfactory results as the nitrates and sulphates.
In using these salts I prepare a solution of an ounce of the salt in a quart of
water in which I dissolve three drachms of tannic acid.
I boil the cotton or linen fabrics, yarns, or material in the solution for about 20
minutes to half an hour, wring out, and air for a few minutes.
The bath of sulphate of iron is prepared using the same quantity of water and
twice the weight of iron to tannin, or not more than 2 times the weight. I
boil the fabric or material in the iron solution for 20 minutes, then immerse in a
dilute alkaline solution (by preference liquor ammonia and water) for two or three
minutes, then wash off the ammonia and any free iron in clean water. I
afterwards return the goods to the tannin bath and then to the iron, boiling for
half an hour or more till the color desired is attained. Nitrate of ammonia and
nitrate of soda give the best blacks. I prefer the use of dilute ammonia to throw
down the tannin and iron to other alkalies.
I also use as mordants salts of the alkaline earths whose bases are insoluble in
water, and these I prefer, as the results by their use are more satisfactory; they are
reliable and uniform in action, the color is better, the operation cleaner, the goods
softer, and the whole process is effected more quickly, and the water is scarcely
soiled.
The mode of working is slightly different. The salts used are those of magnesia
and alumina, either alone or in combination. I prefer the salts of magnesia, as
affording the best coloration, and the sulphate as the readiest for the purpose.
In using the sulphate of magnesia a solution of three ounces to the quart of
water or a saturated solution of the salt may be employed. In it I dissolve three
hundred grs. of tannic acid. In this bath the goods (cotton, linen, &c.) are boiled
for 20 minutes, then wrung out and immersed for half a minute to a minute in a
solution of dilute ammonia. On removal they are aired or kept in a warm
atmosphere for a few minutes till the free ammonia has passed off. I then
immerse them in the sulphate of iron bath, using in the same quantity of water
twice the weight of iron to the tannin. I boil for a quarter of an hour, air for a
few minutes, and again boil for a quarter of an hour. Next I wash off in clean
water to remove any surplus or loose dye, and then return the goods to the tannin
bath, repeating the preceding directions to obtain density of color.
In using the sulphate of alumina I prepare a saturated solution and afterwards
dilute it with twice its bulk of water; this will be strong enough; the color is not
so good as with the magnesian salt; it has a greyish cast but is remarkably durable
and bears washing well.

page_text: The directions given above for the use of the magnesian salts will give a dead
black. If a twentieth part of aniline mauve (Judson's dye) be added to the iron
bath a fine navy blue is the result, a fortieth will give a blue black. Thus I am
able to dye navy blues without the use of indigo.
Wool and silk can be dyed with less tannin in the proportion of, say, 3 to 5.
Silk may advantageously be dyed without boiling.
Having thus described the nature of my Invention, and the manner of performing
the same, I would have it understood that I claim my improvements in dyeing
consisting in the use of tannin with the salt of an alkali or alkaline earth, and
using also ammonia or other alkali and sulphate of iron, substantially as
described.
I also claim the use of the said process with the addition of aniline mauve as
described in dyeing the blue black and navy blues now obtained by means of
indigo.
In witness whereof, I, the said William Edward Gaine, have hereunto set my
hand and seal, this Twenty seventh day of December, in the year of our
Lord One thousand eight hundred and eighty one.
T T SAINT
Gal