AN IMPROVED PROCESS OF UN- GUMMING AND DECOLOURING SILKS IN GENERAL
Year: 1878

page_text: LETTERS PATENT to Eugène Jules Lebouteux, of Paris, Boulevard de Strasbourg,
No. 23, Industrial, for the Invention of "AN IMPROVED PROCESS OF UN-
GUMMING AND DECOLOURING SILKS IN GENERAL."
Sealed the 6th September 1878, and dated the 9th April 1878.
PROVISIONAL SPECIFICATION left by the said Eugène Jules Lebouteux
at the Office of the Commissioners of Patents on the 9th April 1878.
EUGENE JULES LEBOUTEUX, of Paris, Boulevard de Strasbourg, No. 23, In-
dustrial. "AN IMPROVED PROCESS OF UNGUMMING AND DECOLOURING SILKS IN
GENERAL."
It has not been possible heretofore to effect the perfect disgumming and decolorisa-
tion of silks, particularly Tussah silk, without impairing its natural qualities. Tho
processes heretofore employed burn the silk and leave a deposit on the fibres of
mineral salts, which impair the beauty, the dye, and the brilliancy of the silks.
According to my present Invention I employ for the above purpose oxygen in
its nascent state, produced by the combination of oxygenised water with liquid
ammonia.
It has already been proposed to use ozone as a decolorising medium, but it has
not been possible to obtain practical results thereby on account of the re-agents
employed. My Invention therefore consists in the production of the peculiar
re-action above described, and in the application of the product obtained thereby as
a decolorising medium, as also in the particular processes employed for this
purpose.
For the purposes of my Invention a quantity of oxygenised water, containing
about one volume of oxygen to two of water, has added to it sufficient ammonia or
ammoniacal salts to render the bath slightly alkaline. In the bath thus prepared
the silk to be disgummed or decolorised is then immersed, the silk being either in
its natural state or having been slightly disgummed in the first instance. The
silk having been submitted to the action of the bath, firstly for 12 hours in a cold

page_text: state, and then during 24 hours with the bath heated to a temperature not ex-
ceeding 50° centigrade, it is then removed, rinsed, and cleared.
The bath being entirely free from iron and mineral salts, it will be evident that
there will be nothing remaining in the silk which could impair either its lustre or
the dye which it is to receive.
The same result may be obtained by the use of oxygenised water or oxygen in a
nascent state produced by any other process that will not leave deposits of mineral
salts, such as by the decomposition of binoxide of barium by carbonic acid, or in
the presence of bicarbonate of ammonia.
It is necessary in these operations to use exclusively vessels of earthenware, wood,
gutta percha, or other suitable non-metallic substance.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Eugène Jules Lebouteux in the Great Seal Patent Office on the
13th September 1878.
EUGENE JULES LEBOUTEUX, of Paris, Boulevard de Strasbourg, No. 23, In-
dustrial. "AN IMPROVED PROCESS OF UNGUMMING AND DECOLOURING SILKS IN
GENERAL,"
It has not been possible heretofore to effect the perfect disgumming and decolorisa-
tion of silks, particularly Tussah silk, without impairing its natural qualities. The
processes heretofore employed burn the silk and leave a deposit on the fibres of
mineral salts, which impair the beauty of the dye and the brilliancy of the silks.
According to my present Invention I employ for the above purpose oxygen in
its nascent state, produced by the combination of oxygenated water with liquid
ammonia.
It has already been proposed to use ozone as a decolorising medium, but it has
not been possible to obtain practical results thereby on account of the re-agents
employed. My Invention therefore consists in the production of the peculiar
re-action above described, and in the application of the product obtained thereby as
a decolorising medium, as also in the particular processes employed for this
purpose.
For the purposes of my Invention a quantity of oxygenated water, containing
about one volume of oxygen to two of water, has added to it sufficient ammonia or
ammoniacal salts to render the bath slightly alkaline. In the bath thus prepared
the silk to be disgummed or decolorised is then immersed, the silk being either in
its natural state or having been slightly disgummed in the first instance. The
silk having been submitted to the action of the bath, first for 12 hours in a cold
state, and then during 24 hours with the bath heated to a temperature not ex-
ceeding 120° Fahr., it is then removed, rinsed, and cleared.
Yellow or dull grey silks should finally be passed through a boiling soap bath;
the quantity of oxygenated water required varies according to the character and
condition of the silk to be treated.

page_text: On an average, from 3 to 5 pints of the oxygenated water suffice for the treatment
of 1 lb. of silk.
The bath being free from iron and mineral salts, there is no deposit made in the
silk such as can impair its lusture or interfere with its subsequent dyeing.
Instead of using simple ammonia, compounds of ammonia, such as mono, bi, or tri-
methylamine, or their hydrates or hydrate, or tetramethylammonium, or their
homologues, may be employed.
Also the mixture of oxygenated water and ammonia may have added to it am-
moniacal salts, such as the perchlorate, the hypochlorite, nitrate, arseniate, carbonato,
oxalate, or formiate, in the proportion of 40 to 45 grains of the salt to the pint of
oxygenated water. This addition increases the strength and brilliancy of the
fibre.
The oxygenated water may be produced in presence of ammonia or its salts, as for
example by decomposing binoxide of barium by carbonic, sulphuric, or hydro-
fluosilicic acid in presence of ammonia or its carbonate or bicarbonate, sulphate, or
hydrofluosilicate.
The operation may be shortened by first subjecting the silk to a bath containing
10% of carbonate or acetate of soda, or by heating the oxygenated bath and the
material treated under pressure to a temperature ranging between 130° and 200°.
Fahr.
I find the most rapid action takes place in a bath of the oxygenated water and
ammonia with the addition of almost any proportion above 10% of hypochlorite
of ammonia.
°
The treament may be repeated in successive baths if required for effecting
complete decolorisation.
The compounds of chlorine and ammonia, though unstable when concentrated,
become stable in the state of dilute solution in which they should be employed in
this process. They can be prepared by adding to the hypochlorite, of a base such as
calcium, barium, magnesium, or zinc, a weak solution of any ammoniacal salt, such
as the carbonato, sulphate, or phosphate, the acid of which will form with the base
of the hypochlorite an insoluble precipitate, which is removed by filtration.
A good proportion for the bath is such a quantity of hypochlorite as contains 3
to 7 pints of chlorine added to 35 pints of water containing about half its volume of
oxygen, and these quantities will suffice for treating 3 to 5 lbs. of silk, such as
Tussah.
To render the bath slightly alkaline a little ammonia may be added.
The time of treatment varies with the nature of the material, generally as stated
above; an exposure for about 24 hours in the cold bath, and 12 hours at a
temperature of 100° to 120° Fahr., will effect complete decolorisation.
The process above described is applicable to the bleaching of cotton and linen.
Cotton first scoured in lime or rosin soap, then passed through acid, and then after-
wards through weak hypochlorite of ammonia, and again through acid, is treated in
a weak bath of oxygenated water and ammonia; and linen first steeped in soda
solution at 2° for 24 hours, then passed through a weak solution of hypochlorite of
ammonia, and afterwards through acid, is lixiviated in soda salt, and then after being
subjected to a weak bath of oxygenated water and ammonia it is passed through
acid.
The bath and acid treatment may be several times repeated, and the process
may be completed by a final weak bath of oxygenated water and ammonia.
It is to be understood that in all the operations above described no metallic vessels
must be used, but only such as are made of earthenware, cement, wood, gutta percha,
and like substances.
Having thus described the nature of my Invention, and in what manner the same
is to be performed, I claim,―
First. Treating silk by oxygenated water slightly ammoniacal, with or without
the presence of ammoniacal salts, for the purpose of removing the gum and dis-
charging the colour, substantially as herein described.

page_text: Second. Treating silk by oxygenated water and chlorites or hypochlorites,
employed together or separately in presence of ammonia or its salts, for the
purpose of removing the gum and discharging the colour, substantially as herein
described.
In witness whereof, I, the said Eugène Jules Lebouteux, have hereunto
set my hand and seal, this Twelfth day of September, in the year of our
Lord One thousand eight hundred and seventy-eight.
Witness,
JULES ARMENGAUD, jeune,
Civil Engineer,
23, Bd. de Strasbourg,
Paris.
E. J. LEBOUTEUX. (L.S.)