AN IMPROVED METHOD AND MATERIALS FOR THE PRODUCTION OF FIREPROOF DOCUMENTS AND DRAWINGS
Year: 1881

page_text: LETTERS PATENT to John Rudolph Meihé, of No. 2, Laurence Pountney Hill,
in the City of London, for an Invention of "AN IMPROVED METHOD AND
MATERIALS FOR THE PRODUCTION OF FIREPROOF DOCUMENTS AND DRAWINGS."
A communication from abroad by Louis Frobeen, of Berlin, in the German
Empire.
PROVISIONAL SPECIFICATION left by the said John Rudolph Meihé at
the Office of the Commissioners of Patents on the 6th August 1881.
JOHN RUDOLPH MEHÉ, of No. 2, Laurence Pountney Hill, in the City of
London. "AN IMPROVED METHOD AND MATERIALS FOR THE PRODUCTION OF
FIREPROOF DOCUMENTS AND DRAWINGS." [A communication from abroad by
Louis Frobeen, of Berlin, in the German Empire.]
This Invention has for its object the production of printed and manuscript
documents and drawings in such a manner that neither the material on which
these are prepared nor the writing, printing, drawing, or painting can be destroyed
by fire.
Various attempts for producing fireproof documents have been made from time
to time; thus, for instance, a material composed of paper pulp with an admixture
of asbestos has been prepared which is as capable of withstanding moderate
temperatures, but was destroyed by a heat of below 1500° Fahr., that is, below
red heat, and it possessed the further disadvantage that it was too rough for
printing or writing upon.
A really fireproof material, such as will withstand a red heat, has never yet
been manufactured, and even if it had, this by itself would be of little use, as a
writing or printing ink would also be required that would withstand the same
high temperatures, and that would be legible even when blackened with smoke.
According to one part of the present Invention a fireproof paper material is
prepared consisting of about 95 parts of asbestos of best quality washed in a
solution of permanganate of potash, and treated with sulphuric acid, whereby it
becomes bleached, after which it is mixed with 5 parts of ground wood fibre, such
[Price 4d.]

page_text: as is used in paper factories, and the mixture is then treated in an ordinary rag
engine with admixture of lime water and borax. The so prepared paper material
is then converted into sheets either by the hand process or by means of the con-
tinuous paper machine, during which process it may be provided with water marks.
The fireproof paper thus produced, which possesses a smooth surface that may be
perfected by the satin press, is composed entirely of asbestos, and will withstand a
white heat.
According to another part of this Invention fireproof printing and writing inks
are produced from a mixture of chloride of platinum and oil of lavender, which
may be rendered black by adding for printing inks variable proportions of lamp-
black and varnish, and for writing inks, Indian ink with water and gum arabic.
The foundation of the fireproof pigment consists in every case of dry chloride
of platinum and oil of lavender. The following proportions have been found
serviceable for printing ink :-
100 parts.
Other proportions may however be used, and I in no way bind myself to these.
As the chloride of platinum is very hygroscopic, it is first slightly heated in a
porcelain vessel to remove all moisture, after which the oil of lavender is added,
whereupon a strong effervescence ensues under strong development of gas, during
which time the mixture must be stirred until the generation of gas has stopped.
By this means the chloride of platinum is converted into a black tar like or
syruppy mass, to which lampblack and varnish are added in small proportions.
When ink thus prepared is subjected to fire heat the platinum becomes reduced
by the carbon of the lampblack, and forms a brown black residiuum. This
reduction of the platinum will however only take place to a very small extent, or
not at all, if the platinum is not free from acid, but this is easily avoided by
carrying out the above process.
For writing on the fireproof paper a similar ink is prepared that can be used
with an ordinary metallic pen. Suitable proportions for this are as follows:-.
Dry chloride of platinum
5 parts.
but other proportions may be used.
100 parts;
By the use of the above described inks not only is the written or printed
document rendered indestructible by fire, but the written, printed, or drawn
characters or figures receive through the chloride of platinum the property of
rendering the paper transparent, where they occur, on its being heated to a strong
red heat, so that documents that have been rendered illegible by becoming smoked
or from other causes can easily be read on heating them to a red heat.
This property of the ink constitutes an essential feature of the present
Invention.
Such fireproof documents or drawings can also be produced in fireproof colours,
for which purpose the ordinary metallic fireproof colours ("under-glaze colours") i
may be used for printing, writing, or painting on the paper in combination with dry
chloride of platinum and printing or lithographic varnish, to which may, if required,
be added any water colour for imparting greater body.

page_text: The use of a mixture of dry chloride of platinum with printing varnish also in
this case forms the basis of the application of the fireproof colours.
The following may serve as an example for the production of a blue colour :-
Under glaze colour (such as cobalt blue) -
-
45 parts.
Ordinary colour (such as ultramarine water colour) : 14 "
Other proportions may however be used.
The use of the dry chloride of platinum is also of great importance in this case,
because without it the colour would not become sufficiently transparent on heating
to a red heat. In a similar manner colours of different tints may be prepared by
treating metallic underglaze colours according to the above method.
Fireproof water colours can also be produced in a similar manner, specially
applicable for preparing important plans and surveys, by the use of the said
metallic underglaze colours with chloride of platinum, such colours possessing in
addition to their fireproof property all the qualities of the ordinary colours used for
these purposes. Such colours may be prepared as follows:-
114
100 parts.
The metallic or underglaze colour is first levigated, and is then boiled with the
25 desired water colour, and to the boiling mixture is then added a suitable quantity
of chloride of platinum dissolved in water, together with gum arabic or other
cement. The fireproof colour thus produced is used like ordinary water colour.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said John Rudolph Meihé in the Great Seal Patent Office on the
4th February 1882.
JOHN RUDOLPH MEIHÉ, of No. 2, Laurence Pountney Hill, in the City of
London. "AN IMPROVED METHOD AND MATERIALS FOR THE PRODUCTION OF
FIREPROOF DOCUMENTS AND DRAWINGS." A communication from abroad by
Louis Frobeen, of Berlin, in the German Empire.
This Invention has for its object the production of printed and manuscript
documents and drawings in such a manner that neither the material on which
these are prepared nor the writing, printing, drawing, or painting can be destroyed
by fire.
Various attempts for producing fireproof documents have been made from time
to time; thus, for instance, a material composed of paper pulp with an admixture
of asbestos has been prepared which was capable of withstanding moderate
temperatures, but was destroyed by a heat of below 1500° Fabr., that is, below
red heat, and it possessed the further disadvantage that it was too rough for printing
or writing upon.
.
A really fire proof material, such as will withstand a red heat, has never yet
been manufactured, and even if it had this by itself would be of little use, as a
writing or printing ink would also be required that would withstand the same
high temperatures and that would be legible even when blackened with smoke.
According to one part of the present Invention a fire proof paper material is
prepared consisting of about 95 parts of asbestos of best quality washed in a
solution of permanganate of potash and treated with sulphuric acid, whereby it
becomes bleached, after which it is mixed with 5 parts of ground wood fibre, such
as is used in paper factories, and the mixture is then treated in an ordinary rag
engine with admixture of lime water and borax. The so prepared paper material
is then converted into sheets either by the hand process or by means of the
continuous paper machine, during which process it may be provided with water
marks. The fire proof paper thus produced, which possesses a smooth surface that
may be perfected by the satin press, is composed entirely of asbestos and will
withstand a white heat.
According to another part of this Invention fireproof printing and writing inks
are produced from a mixture of chloride of platinum and oil of lavender, which
may be rendered black by adding for printing inks variable proportions of
lamp-black and varnish, and for writing inks indian ink with water and gum
arabic.
The foundation of the fireproof pigment consists in every case of dry chloride of
platinum and oil of lavender. The following proportions have been found serviceable
for printing ink :—
100 parts.
Other proportions may however be used, and I in no way bind myself to these.
As the chloride of platinum is very hygroscopic, it is first slightly heated in a
porcelain vessel to remove all moisture, after which the oil of lavender is added,
whereupon a strong effervescence ensues under strong development of gas, during
which time the mixture must be stirred until the generation of gas has stopped.
By this means the chloride of platinum is converted into a black-tar like or syruppy

page_text: mass, to which lamp-black and varnish are added in small proportions. When ink
thus prepared is subjected to fire heat the platinum becomes reduced by the carbon
of the lamp-black and forms a brown black residuum. This reduction of the
platinum will however only take place to a very small extent, or not at all, if the
platinum is not free from acid, but this is easily avoided by carrying out the above
process.
For writing on the fireproof paper a similar ink is prepared that can be
used with an ordinary metallic pen. Suitable proportions for this are as
follows:-
but other proportions may be used.
100 parts;
By the use of the above described inks not only is the written or printed
document rendered indestructible by fire, but the written, printed, or drawn
characters or figures receive through the chloride of platinum the property of
rendering the paper transparent where they occur on its being heated to a strong
red heat, so that documents that have been rendered illegible by becoming smoked
or from other causes can easily be read on heating them to a red heat.
This property of the ink constitutes an essential feature of the present
Invention.
Such fireproof documents or drawings can also be produced in fire-proof colours,
for which purpose the ordinary metallic fireproof colours ("underglaze colours")
may be used for printing, writing, or painting on the paper, in combination with
dry chloride of platinum and printing or lithographic varnish, to which may if
required be added any water colour for imparting greater body. The use of
a mixture of dry chloride of platinum with printing varnish also in this case forms
the basis of the application of the fireproof colours.
The following may serve as an example for the production of a blue
aloun
Other proportions may however be used.
The use of the dry chloride of platinum is also of great importance in this case,
because without it the colour would not become sufficiently transparent on heating
to a red heat. In a similar manner colours of different tints may be prepared by
treating metallic underglaze colours according to the above method.
Fireproof watercolours can also be produced in a similar manner, specially
applicable for preparing important plans and surveys, by the use of the said
metallic underglaze colours with chloride of platinum, such colours possessing in
addition to their fireproof property all the qualities of the ordinary colours used
for these purposes. Such colours may be prepared as follows:-

page_text: The metallic or underglaze color is first levigated, and is then boiled with the
desired water colour, and to the boiling mixture is then added a suitable quantity
of chloride of platinum dissolved in water, together with the gum arabic or
other cement. The fireproof colour thus produced is used like ordinary water
colour.
Having thus described the nature of this Invention, and in what 'manner
the same is to be performed, as communicated to me by my foreign correspondent,
I claim,―
First. The production of a fireproof colour or pigment for printing composed of
chloride of platinum, oil of lavender, lamp black, and varnish, substantially as
herein described.
Second. The production of a fire proof ink or pigment composed of chloride of
platinum, oil of lavender, indian ink, water, and gum-arabic, substantially as
herein described.
Third. The production of a fire proof colour or pigment composed of underglaze
colour and chloride of platinum, substantially as herein described.
Fourth. The production of a fireproof watercolour consisting of underglaze
colour, chloride of platinum, and a binding material soluble in water, substantially
as herein described.
Fifth. The use of the fireproof colours or pigments referred to in the several
preceding claims for printing, writing, drawing, or painting on asbestos or other
suitable paper.
In witness whereof, I, the said John Rudolph Meibé, have hereunto set my
hand and seal, this Fourth day of February, in the year of our Lord One
thousand eight hundred and eighty two.
JOHN RUDOLPH MEIHE. (L.S.)