IMPROVEMENTS IN BITUMINOUS CEMENTS AND COMPOSITIONS FOR PAVING AND OTHER PURPOSES
Year: 1881

page_text: «
LETTERS PATENT to John Henry Johnson, of 47, Lincoln's Inn Fields, in the
County of Middlesex, Gentleman, for an Invention of IMPROVEMENTS IN
BITUMINOUS CEMENTS AND COMPOSITIONS FOR PAVING AND OTHER PURPOSES."
A communication from abroad by Edward J. De Smedt, of Washington, D.C.,
and William J. Twining, Major of Engineers, United States Army, both in the
United States of America.
PROVISIONAL SPECIFICATION left by the said John Henry Johnson at
the Office of the Commissioners of Patents on the 28th February 1881.
JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
Gentleman. "IMPROVEMENTS IN BITUMINOUS CEMENTS AND COMPOSITIONS FOR
PAVING AND OTHER PURPOSES." A communication from abroad by Edward
J. De Smedt, of Washington, D.C., and William J. Twining, Major of Engineers,
United States Army, both in the United States of America.
It is well established that the relatively quick destruction or deterioration of a
bituminous pavement is due in part to the evaporation of certain volatile hydro-
carbons during the heat of summer, but chiefly to the gradual oxidation of
the bituminous substances used as the matrix, which after a certain time
changes the nature of the matrix and produces to a greater or less extent
disintegration.
Coal tar products are much more subject to oxidation by atmospheric air and
other natural influences than are the asphalte products. But the coal tar products
have certain qualities which asphalts do not possess, viz., adhesiveness and great
tensile strength coupled with impermeability resulting from a lack of affinity for
moisture, and they combine to render the coal tar products a particularly valuable
element in bituminous cement. It is therefore desirable to so prepare these
products preliminarily to their use in a bituminous cement or composition that they
shall not thereafter be liable to appreciable evaporation or oxidation under the

page_text: natural influences to which the cement or composition may be subjected during its
period of use.
According to this Invention this object is effected in the following manner :-
I subject the coal tar products (obtained as a residuum by the distillation of coal
tar) while in a heated and melted condition to the action of an oxidizing agent or
an agent which will readily give up its oxygen to the said products when brought
in contact therewith. I prefer to maintain the heat at, say, about 300° Fahrenheit,
inasmuch as I thereby obtain two results. I bring the coal tar products to a con-
dition in which they will more readily combine with the oxidizing agent to produce
the reaction, and I at the same time drive off or evaporate from the said products
oils volatile under 200° Fahrenheit, thus removing constituents which might in a
pavement evaporate by summer heat.
One way of proceeding is as follows:-
The proper coal tar product is placed in suitable known apparatus and is there
heated to, say, about 300° Fahrenheit, at which temperature it is maintained for
twenty four hours more or less in order to drive off oils volatile under 200°
Fahrenheit. The temperature and duration of the operation may however be
varied. For instance, by maintaining the product a longer time at a somewhat
lower temperature the same or approximately the same result might be obtained.
During this process of evaporation I oxydize more or less completely the coal tar
product. This I effect by adding to the said product in proper quantity a
substance which will readily give up its oxygen, of which substances there are
many, for instance, permaganate of potash or preferably permanganic acid. This
agent either powdered or in solution is added gradually and in small quantities, and
is thoroughly stirred into the heated coal tar product in order to ensure a perfect
mixture. The permanganic acid in contact with the coal tar product is transformed
into sesqui-oxide of manganese MB 03 by the loss of four atoms of oxygen which
combine with the coal tar product. In practice one pound of permanganic acid has
been found to be a sufficient quantity for the necessary oxydation of one ton of the
coal tar products before named.
It is not necessary nor perhaps desirable to entirely oxydize the coal tar product;
this would approximate it too closely to an asphalt and would impair its tenacity
and tensile strength. For practical purposes, and with a view to its use in
pavements and the like, it is only necessary to carry the process sufficiently far
to ensure that there shall be no appreciable oxydation during the lifetime of the
pavement.
Besides permanganate of potash or permanganic acid there are other known
substances which can be used, some of which, for instance, picric acid, are preferable
on some accounts to permanganic acid.
The substances referred to give up their oxygen freely in the presence of coal tar
products under the conditions before mentioned, while they do not decompose or
exercise a destructive effect as some acids (such as nitric, chromic, and sulphuric) do.
upon the material.
The oxydized product herein described may be used either alone or in conjunction
with other bituminous substances not only for paving but for roofing, coating iron and
other metal, wood, and the like, and in a paint or composition for coating ships'
bottoms or the like. The said product can also be used in combination with known
oxyginated heavy hydrocarbon oils, whether with or without additional substances
in making a composition or cement for paving and other purposes.
The herein described process, with some modification, can be successfully applied
to heavy oils of petroleum, whether natural or resulting from the distillation of
petroleum, to bring them to the condition of an asphalt or oxygenated bitumen.
One way of proceeding is as follows:-The heavy petroleum oil is heated in a
suitable tank to, say, about 250 °Fahrenheit; while thus heated I mix gradually into
it the oxydizing agent, c.g., permanganic acid or picric acid. I find that for all
practical purposes three hundred (300) grammes of the acid to one ton of the heavy

page_text: petroleum is sufficient, and the oxydizing process is practically over in from a
quarter to half an hour.
The temperature of the oxydized product is then raised to about 500° Fahrenheit,
at which heat (maintained for about an hour) are driven off a small per centage of
volatile substances evolved by and during the oxydizing process, and also other
volatile substances pre-existent in the petroleum as well as some oils not oxydized.
The mass of the petroleum by this process is transformed into a practically homo-
geneous oxydized bitumen which possesses great tenacity and tensile strength and
renders the bituminous cement or composition into which it may enter less brittle
and less liable to be affected by the action of air or water.

page_text: :
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Henry Johnson in the Great Seal Patent Office on the
23rd August 1881.
JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
Gentleman. "IMPROVEMENTS IN BITUMINOUS CEMENTS AND COMPOSITIONS FOR
PAVING AND OTHER PURPOSES." A communication from abroad by Edward
J. De Smedt, of Washington, D.C., and William J. Twining, Major of Engineers,
United States Army, both in the United States of America.
It is well established that the relatively quick destruction or deterioration of a
bituminous pavement is due in part to the evaporation of certain volatile hydro-
carbons during the heat of summer, but chiefly to the gradual oxidation of the
bituminous substances used as the matrix, which after a certain time changes the
nature of the matrix and produces to a greater or less extent disintegration."
Coal tar products are much more subject to oxidation by atmospheric air and
other natural influences than are the asphalte products; but the coal tar products
have certain qualities which asphaltes do not possess, viz., adhesiveness and great
tensile strength coupled with impermeability, resulting from a lack of affinity for
moisture, and they combine to render the coal tar products a particularly valuable
element in bituminous cement. It is therefore desirable to so prepare these
products preliminarily to their use in a bituminous cement or composition that
they shall not thereafter be liable to appreciable evaporation or oxidation under
the natural influences to which the cement or composition may be subjected during
its period of use.
According to the said Invention this object is effected in the following manner,
viz. I subject the coal tar products (obtained as a residuum by the distillation
of coal tar) while in a heated and melted condition to the action of the oxydizing
agent, or an agent which will readily give up its oxygen to the said products when
brought in contact therewith. I prefer to maintain the heat at, say, about 300°
Fahrenheit, inasmuch as I thereby obtain two results, I bring the coal tar products
to a condition in which they will more readily combine with the oxydizing agent to
produce the reaction, and I at the same time drive off or evaporate from the said
products oils volatile under 200° Fahrenheit, thus removing constituents which
might in a pavement evaporate by summer heat.
One way of proceeding is as follows:-
The proper coal tar product is placed in suitable known apparatus, and is there
heated to, say, about 300° Fahrenheit, at which temperature it is maintained for
twenty four hours, more or less, in order to drive off oils volatile under 200°
Fahrenheit. The temperature and duration of the operation may however be varied;
for instance, by maintaining the product a longer time at a somewhat lower tempe-
rature the same or approximately the same result might be obtained. During this
process of evaporation. I oxydize more or less completely the coal tar product. This
I effect by adding to the said product in proper quantity a substance which will
readily give up its oxygen, of which substances there are many, for instance, perman-
ganate of potash, or preferably permanganic acid. This agent, either powdered or
in solution, is added gradually and in small quantities, and is thoroughly stirred
into the heated coal tar product in order to insure a perfect mixture. The per-
manganic acid in contact with the coal tar product is transformed into sesquioxide
of manganese, MB 08, by the loss of four atoms of oxygen which combine with the
coal tar product. In practice one pound of permanganic acid has been found to be

page_text: a sufficient quantity for the necessary oxydation of one ton of the coal tar products
before named.
It is not necessary nor perhaps desirable to entirely oxydize the coal tar product;.
this would approximate it too closely to an asphalt and would impair its tenacity
and tensile strength. For practical purposes and with a view to its use in
pavements and the like it is only necessary to carry the process sufficiently far to
insure that there shall be no appreciable oxydation during the lifetime of the
pavement.
In lieu of permanganate of potash or permanganic acid there are other known
substances which can be used, some of which, for instance, picric acid, are preferable
on some accounts to permanganic acid. The substances referred to give up their
oxygen freely in the presence of coal tar products, under the conditions before
mentioned, while they do not decompose or exercise a destructive effect as some
acids (such as nitric, chromic, and sulphuric) do upon the material.
The oxydised product herein described may be used either alone or in conjunction
with other bituminous substances, not only for paving but for roofing, coating
iron and other metal, wood, and the like, and in a paint or composition for coating
ships' bottoms or the like. The said product can also be used in combination with
known oxygenated heavy hydrocarbon oils, whether with or without additional
substances, in making a composition or cement for paving and other purposes.
The herein described process with some modification can be successfully applied
to heavy oils of petroleum, whether natural or resulting from the distillation
of petroleum, to bring them to the condition of an asphalt or oxygenated
bitumen.
One way of proceeding is as follows:-The heavy petroleum oil is heated in a
suitable tank to, say, about 250° Fahrenheit. While thus heated I mix gradually
into it the oxydising agent, permanganic acid or picric acid (for example). It has
been found that for all practical purposes three hundred (300) grammes of the
acid to one ton of the heavy petroleum is sufficient, and the oxydizing process is
practically over in from a quarter to a half an hour.
The temperature of the oxydized product is then raised to about 500° Fahrenheit,
at which heat (maintained for about an hour) are driven off a small per-centage of
volatile substances evolved by and during the oxidizing process and also other
volatile substances pre-existent in the petroleum as well as some oils not oxydized.
The mass of the petroleum by this process is transformed into a practically
homogeneous oxydized bitumen, which possesses great tenacity and tensile strength,
and renders the bituminous cement or composition into which it may enter less
brittle and less liable to be affected by the action of air or water.
The above described oxydized hydro-carbon product, whether made from coal
tar or from heavy oils of petroleum, can be used to advantage either alone or in
conjunction with other proper substances or materials as an insulating or non-
conducting body for electrical purposes, for instance, for coating or covering
telegraph wires, especially underground, and sub-marine wires and cables.
Having now described and particularly ascertained the nature of the said
Invention, and the manner in which the same is or may be used or carried into
effect, I would observe in conclusion that what I consider to be novel and
original, and therefore_claim as the Invention secured to me by the hereinbefore
in part recited Letters Patent is,-
First. The method of treating coal tar products, which consists in subjecting the
said products while maintained in a heated condition to the action of an oxydizing
agent, substantially as hereinbefore described.
Second. The oxydized coal tar product hereinbefore described.
Third. The application and use to and in the manufacture of bituminous cements
and compositions for paving and other purposes of coal tar products deprived of
their more volatile oils and oxydized, substantially as and for the purposes herein-
before set forth.

page_text: Fourth. The treatment of heavy oils of petroleum, substantially as and for the
purposes hereinbefore described.
In witness whereof, I, the said John Henry Johnson, have to this my
Specification set my hand and seal, this Seventeenth day of August, One
thousand eight hundred and eighty one.
J. HENRY JOHNSON. (L.S.)