AN IMPROVED PROCESS FOR FORMING A HARD PROTECTIVE OR ORNAMENTAL COVERING OF INDIA-RUBBER OR GUTTA PERCHA UPON THE SURFACE OF METAL, WOOD, CLAY, AND OTHER MATERIALS,
Year: 1871

page_text: LETTERS PATENT to George Temple Chapman, of the City and
State of New York, United States of America, now of No. 8,
Southampton Buildings, London, Gentleman, for the Invention
of "AN IMPROVED PROCESS FOR FORMING A
HARD PROTECTIVE OR
ORNAMENTAL COVERING OF INDIA-RUBBER OR GUTTA PERCHA UPON THE
SURFACE OF METAL, WOOD, CLAY, AND OTHER MATERIALS,'
.
°
.
PROVISIONAL SPECIFICATION left by the said George Temple
Chapman at the Office of the Commissioners of Patents, with his
Petition, on the 16th September 1871.
I, GEORGE TEMPLE CHAPMAN, of the City and State of New York,
United States of America, now of No. 8, Southampton Buildings,
London, Gentleman, do hereby declare the nature of the said Invention
for "AN IMPROVED PROCESS FOR FORMING A HARD PROTECTIVE OR ORNAMENTAL

page_text: COVERING OF INDIA-RUBBER OR GUTTA PERCHA UPON THE SURFACE OF METAL,
WOOD, CLAY, AND OTHER MATERIALS," to be as follows:--
The main object of my Invention is the protection of metal, wood,
earthenware, and other surfaces from oxidation, corrosion, and other
destructive influences to which the said surfaces would be liable if left
unprotected, and I effect this object by the application to such surfaces
and the subsequent hardening thercon of a solution of india-rubber or
gutta percha. Another object of the said Invention is the ornamentation
of various articles and objects by the application of the aforesaid solution
of india-rubber and gutta percha, which by the addition to it of various
materials may be made of any desired colour.
My Invention consists in the manner of hardening the solution, which
I effect without the employment of sulphur.
In practising the said Invention I may first dissolve the india-rubber
or gutta percha by the aid of turpentine, benzole, sulphide of carbon,
naphtha, or other solvent, or I may melt it by the application of heat.
In the latter case the operation is best performed in vacuo at a
temperature of from three hundred to four hundred degrees Fahrenheit.
This solution is then mixed with colouring material, of such colours.
and in such proportions as will best adapt it for its destined use. The
ochres, metallic oxides, vermillion, and lampblack will be found.
particularly useful. These substances should be reduced to an
impalpable powder and ground with the dissolved or melted india-
rubber or gutta percha in a paint mill to ensure their being thoroughly
mixed or incorporated with the same.
The solution may be applied to the surfaces to be protected by a brush
or by the immersion of the articles or objects in the said solution,
or where the interior of any utensil or vessel or hollow object or article
is to be coated, the solution may be poured into or through the same. I
then harden the coating by the application of heat without sulphur.
The heat required for ordinary purposes will be from about three
hundred to four hundred degrees Fahrenheit, but in some cases the
temperature may be raised or lowered. The time required for
completing the hardening of the coating will vary from one hour to
twenty-four hours, according to the nature of the material on which
the coating is applied. The heating may either be dry or with steam. .

page_text: By thus hardening the solution without the use of sulphur (which
has heretofore been considered indispensable for this purpose), I simplify
the process of hardening and am enabled to apply over the coating
many substances which would be destroyed by the chemical action
of the sulphur, as for instance metallic powder, which will retain all
its brilliancy instead of being tarnished and blackened as would be
the case if the coating were hardened or vulcanized with sulphur.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said George Temple Chapman in the Great Seal
Patent Office on the 15th March 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE
TEMPLE CHAPMAN, of the City and State of New York, United States
of America, now of No. 8, Southampton Buildings, London, Gentleman,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Sixteenth day of September, in the year
of our Lord One thousand eight hundred and seventy-one, in the thirty-
fifth year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said George Temple Chapman, Her special
licence that I, the said George Temple Chapman, my executors,
administrators, and assigns, or such others as I, the said George
Temple Chapman, my executors, administrators, and assigns, should
at any time agree with, and no others, from time to time and at all
times thereafter during the term therein expressed, should and lawfully
might make, use, exercise, and vend, within the United Kingdom of
Great Britain and Ireland, the Channel Islands, and Isle of Man, an
Invention for "AN IMPROVED PROCESS FOR FORMING A HARD PROTECTIVE OR
ORNAMENTAL COVERING OF INDIA-RUBBER OR GUTTA PERCHA UPON THE SURFACE
OF METAL, WOOD, CLAY, ANd OTHER MATERIALS," upon the condition
(amongst others) that I, the said George Temple Chapman, my
executors or administrators, by an instrument in writing under my,
or their, or one of their hands and seals, should particularly describe
and ascertain the nature of the said Invention, and in what manner
the same was to be performed, and cause the same to be filed in

page_text: the Great Seal Patent Office within six calendar months next and
immediately after the date of the said Letters Patent.
:
NOW KNOW YE, that I, the said George Temple Chapman, do hereby
declare the nature of the said Invention, and in what manner the
same is to be performed, to be particularly described and ascertained in
and by the following statement:-
My Invention consists in the hardening of india-rubber and other
similar gums upon the inner or outer surfaces of metallic and other
articles and substances capable of withstanding the necessary degree
of heat, by heat alone (dispensing with the use of sulphur or other ]
vulcanizing agent), after reducing the raw gum to the liquid state of
requisite consistency by melting or dissolving it, or both, and applying
the liquified gum in any convenient way to whatever object it is desired
to furnish with a hard surface for protection, utility, or ornament.
In practising this Invention I take the raw or crude india-rubber or 1
gutta percha of commerce, and first reduce it to a liquid state by either
one of two distinct ways.
The first method is by distilling the gum in a closed or an open vessel
by applying fire or steam heat of 300° Fahrenheit or more, until it is
thoroughly melted and liquified. It may afterwards be reduced or a
thinned by mixing with it a hydro-carbonaceous solvent, but this is not
necessary, though usually convenient.
The second method is by dissolving the gum with a solvent alone,
without any increase of the natural heat of the materials; that is to say,
without melting or assisting the action of the solvents by heating.
Sometimes a combination of the two separate methods may be
employed to advatange. The fundamental theory of my discovery
is that vulcanizable gums, melted by heat or in solution by the aid of
hydrocarbon solvents, can be hardened as a coating or moderately thick
enamel on the surfaces of metallic, wooden, and other solid substances
and wares, capable of withstanding the effects of a great heat by the
application and use of heat alone without the use of sulphur or any
other substances whatever, such as have been heretofore supposed
essential to the end and object of hardening. By this means I produce
a material as a coating which has all the desirable properties of hard
rubber or ebonite, vulcanite, or by whatever names vulcanized gums,,

page_text: that is to say, gums hardened by means of sulphur or the like, may
be called.
Having thus liquified the gums I next cleanse them by straining
through sieves, muslin, or flannel cloth, and by allowing the particles
of dirt to settle, and then pouring off the clear material. To prevent
the swelling of the raw dissolved gums they are dissolved in alcohol,
and ground in a mill, and the material then further dissolved with the
common hydrocarbons.
The
For many purposes, as in the coating of wires used in telegraphy, the
melted gum is used without thinning or diluting with solvents.
liquid gums may be applied at this stage to the materials requiring the
coating, either in their present pure and unmixed condition, or with the
addition of metallic oxides, ochres, or other coloring matters; or with
the use of litharge, boiled oil, and other mordants, and with resinous or
pitchy substances, as asphalt and coal tar, for economy; or with ground
glass, silica, flints, iron filings, earthy matters, varnishes, bronzes, and
the like; all of these being for ornament or utility, and not absolutely
necessary in practising this Invention. The gums being ready for use
are spread on the surface of the wares to be coated with a brush or by
dipping, as varnishes and japans are applied. If dipped, the excess is
allowed to drain off, until by evaporation of the solvent, or by the drying
action of the air the coating is fixed, and then the articles so covered are
placed in an oven, or they are put into the oven at once without waiting
for the gum to dry.
The hardening is now effected by closing the oven door and raising
the heat inside to a point as near as possible from 290° to 295°
Fahrenheit, but this is practically very difficult in a large and especially
in a very high oven, as the heat is always greater at the top than at the
bottom of the oven. Too much heat causes brittleness of the enamel,
although for some purposes a temperature of 350° is not injurious. Too
low a heat, as 275° or 280° Fahrenheit, requires a long time to effect the
change called hardening. It is just here that practical skill and
familiarity with the process and with the manufacture of india-rubber
is needed most. The wares are baked or heated from one to twenty-four
hours, and the process is completed.
The essential steps of the process as practised by me are thus three in
number: 1. Melting with heat or dissolving with solvents, including

page_text: cleansing and colouring. 2. Applying the material thus prepared by
painting on or dipping the articles on which the enamelled coat is
required. 3. Hardening the coating by heat alone.
-
The principal objects to be attained by this Invention are protection
from rust and decay, prevention of fouling of ships' bottoms, 5
improvements in telegraphic isolation, and improved substitutes for
japans, varnishes, and paints.
Having thus fully described the nature of my said Invention and the
manner of performing the same, I claim as a new manufacture the
hardening of india-rubber, gutta percha, and similar gums by a high 1
degree of steam or dry heat alone, applied as an inner or outer surface
after being melted by heat or dissolved by a solvent, or both.
In witness whereof, I, the said George Temple Chapman, have.
hereunto set my hand and seal, this Ninth day of March, in the
year of our Lord One thousand eight hundred and seventy-two.
1
Witness,
GEORGE TEMPLE CHAPMAN. (L.S.)
GEORGE HASELTINE,
8, Southampton Buildings,
London, W.C.