Process of Dyeing Silk a Solid Black by Means of Alizarinė, Flavo- purpurine, Anthrapurpurine, and Mixtures of these Bodies.
Year: 1891

page_text: Date of Application, 3rd July. 1891
Complete Specification Left, 28th Mar., 1892-Accepted. 30th Apr., 1892
PROVISIONAL SPECIFICATION.
[Communicated from abroad by THE FARBWERKE VORMALS MEISTER LUCIUS
AND BRUNING, of Hoechst-am-Main, in the Empire of Germany, Chemical
Manufacturers.]
Process of Dyeing Silk a Solid Black by Means of Alizarinė, Flavo-
purpurine, Anthrapurpurine, and Mixtures of these Bodies.
1, OLIVER IMRAY of 28 Southampton Buildings, Chancery Lane in the
County of London, Fellow of the Institute of Patent Agents, do hereby declare
the nature of this invention to be as follows:-
The black and dark-brown (for linings and imitation sealskins) actually dyed on
silk by means of logwood are not fast against acids, and by reason hereof they
suffer from the action of perspiration and are not carbonisable.
Moreover they do not possess absolute resistance against soap and are not fast
against alkali.
All interested in the silk industry are consequently desirous of obtaining a process
for producing a really fast black.
My foreign correspondents, by making use of alizarine, have succeeded in
producing such a black, and not only has the progress so much desired been
realised by this fact, but at the same time the cost of dyeing has been considerably
lessened.
EXAMPLE.
Boiled silk is mordanted, one or more times, according to the degree of
weightening that is desired to give it, and each time during two hours, with ferric
sulphate of 30° Be. After the last mordanting the silk is well soaped and treated
in a fresh bath with such a quantity of ferro cyanide of potassium (yellow prussiate
of potash) and hydrochloric acid as corresponds to the oxide of iron on the fibre.
In this manner the silk receives a strong ground of Berlin blue.
The silk is now passed into a boiling bath containing the quantity of cutch and
tin-salt corresponding to the degree of weightening,
After having been worked several hours in this bath the silk is washed and passed
to a second bath of cutch, in order to couple to tannic acid all the tin that in the
first bath has got fixed on the fibre. The silk is again well washed and is now\
ready for the dyeing.
The silk can also be prepared in the following way:
Crude or boiled silk is mordanted with a tin tetra chloride solution of 30°, one or
more times according to the degree of weightening to be given, it is then washed
well and, as before said, is treated one or more times with ferric sulphate in the
manner set forth; it is then, as described above, passed through yellow prussiate
of potash and hydrochloric acid and finally is brought into a boiling bath containing
the quantity of cutch corresponding to the degree of weightening given. When
the silk has been treated in this bath a sufficient length of time, it is well washed and
is now ready for the dyeing.
The manner of dyeing is the same, whether the silk has been prepared in the
first or in the second way, namely:
A weak soap bath is prepared containing for every pound of silk 20 to 25 pounds
of water and a quantity of soap varying from 15 to 20 per cent. of the weight of the
silk, according to the degree of hardness of the water, so that, as is commonly said,
the bath will stand in soap. To this bath is added the quantity of alizarine required
for producing the desired shade, which quantity will vary from 20 to 50 per cent. of
the weight of the soap.

page_text: The silk is brought into this bath at a temperature of about 65° C. and is worked
for about hour.
The temperature is then raised to boiling point and the silk worked again at 95° C.
for hour.
When the desired shade has been arrived at, the silk is taken off, a further
quantity of soap is added to the bath, so as to make it very fat and then the bath
is heated to ebullition. The silk is brought in again and worked another hour, to
give lustre and touch.
When the dyeing is finished, the silk is brought for a few minutes into a bath
of 30° C. rendered slightly alkaline by the addition of carbonate of soda. The
silk is then well washed and treated with an acid, some size, and an oil emulsion
(brightening); finally it is shaken out and dried.
The color obtained in this way is fast against acids and alkalies and also against
the influence of sun-light.
By alizarine is understood not only the alizarine properly so called, but also
flavopurpurine, anthrapurpurine and mixtures of these bodies."
Dated this 3rd day of July 1891.
ABEL & IM.KA),
Agents for the Applicant.
COMPLETE SPECIFICATION.
Process of Dyeing Silk a Solid Black by Means of Alizarine, Flavo-
purpurine, Anthrapurpurine, and Mixtures of these Bodies.
I, OLIVER IMRAY, of 28 Southampton Buildings, Chancery Lane, in the County
of London, Fellow of the Institute of Patent Agents, 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:-
The black and dark-brown (for linings and imitation sealskins) hitherto dyed on
silk by means of logwood are not fast against acids, and by reason hereof they
suffer from the action of perspiration and are not carbonisable.
Moreover they do not possess absolute resistance against soap and are not fast
against alkali.
All interested in the silk industry are consequently desirous of obtaining a
process for producing a really fast black.
My foreign correspondents, by making use of alizarine, have succeeded in pro-
ducing such a black, and not only has the progress so much desired. been realised by
this fact, but at the same time the cost of dyeing has been considerably lessened.
EXAMPLE.
Boiled silk is mordanted, one or more times, according to the degree of
weightening that. is desired to give it, and each time during two hours, with ferric
sulphate of 30° Bé. After the last mordanting the silk is well soaped and treated
in a fresh bath with such a quantity of ferro cyanide of potassium (yellow prussiate
of potash) and hydrochloric acid as corresponds to the oxide of iron on the fibre.
In this manner the silk receives a strong ground of Berlin blue.
The silk is now passed into a boiling bath containing the quantity of cutch and
tin-salt corresponding to the degree of weightening.
After having been worked several hours in this bath the silk is washed and
passed to a second bath of cutch, in order to couple to tannic acid all the tin that in
the first bath has got fixed on the fibre. The silk is again well washed and is now
ready for the dyeing.
The silk can also be prepared in the following way:
Crude or boiled silk is mordanted with a tin tetra chloride solution of 30°, one or
more times according to the degree of weightening to be given, it is then washed

page_text: well and, as before said, is treated one or more times with ferric sulphate in the
manner set forth; it is then, as described above, passed through yellow prussiate of.
potash and hydrochloric acid and finally is brought into a boiling bath containing
the quantity of cutch corresponding to the degree of weightening given. When
the silk has been treated in this bath a sufficient length of time, it is well washed
and is now ready for the dyeing.
The manner of dyeing is the same, whether the silk has been prepared in the first
or in the second way, namely
:-
A weak soap bath is prepared containing for every pound of silk 20 to 25 pounds
of water and a quantity of soap varying from 15 to 20 per cent. of the weight of the
silk, according to the degree of hardness of the water, so that, as is commonly
said, the bath will stand in soap. To this bath is added the quantity of alizarine
required for producing the desired shade, which quantity will vary from 20 to
50 per cent. of the weight of the soap.
The silk is brought into this bath at a temperature of about 65° C. and is worked
for about
hour.
The temperature is then raised to boiling point and the silk worked again at 95° C.
for hour.
When the desired shade has been arrived at, the silk is taken off, a further
quantity of soap is added to the bath, so as to make it very fat and then the bath
is heated to ebullition. The silk is brought in again and worked another hour, to
give lustre and touch.
When the dyeing is finished, the silk is brought for a few minutes into a bath
of 30° C. rendered slightly alkaline by the addition of carbonate of soda. The silk
is then well washed and treated with an acid, some size, and an oil emulsion
(brightening); finally it is shaken out and dried.
The color obtained in this way is fast against acids and alkalies and also against
the influence of sun-light.
By alizarine is understood not only the alizarine properly so called, but also
Havopurpurine, anthrapurpurine and mixtures of these bodies."
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
:-
1. The process for dyeing silk black shades fast against acids and alkalies, by
grounding the silk Berlin blue, treating it with cutch or other tannic body and
tinsalt or by mordanting the silk with tin tetrachloride grounding it Berlin blue,
treating it with cutch or equivalent and finally topping it in the soap bath with
alizarine or its equivalents, substantially as described.
2. Silk fibres or textures dyed solid black or dark brown shades by the means
above set forth.
Dated this 24th day of March 1892.
ABEL & IMRAY,
Agents for the Applicant.