Improvements in the Manufacture of Artificial Ivory or Ivory Substitutes.
Year: 1889

page_text: Date of Application, 4th June, 1889
Complete Specification Left, 21st Dec., 1889-Accepted, 22nd Mar., 1890
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Artificial Ivory or Ivory
Substitutes.
We, ALEXANDRE DE PONT and SILVIUS DE PONT, both of Paris, in the Republic of
France, but temporarily at the Office for Patents, 6 Bank Street, Manchester, in the
County of Lancaster, Manufacturers, HERBERT LUSHINGTON STOREY and ISAAC HENRY
STOREY, both of Lancaster in the County of Lancaster, Manufacturers, do hereby
declare the nature of this invention to be as follows:-
The invention relates to a new or improved method by which we can construct
artificially an ivory having the same properties, component parts and appearance as
the material product.
Hitherto inventions for the manufacture of substitutes for ivory have been based
upon the solidification of animal or vegetable substances with agglutinants or by
subjecting such substances to heat in order to render them plastic and capable of
being compressed or moulded into the required shape. The results of these different
methods, however, have not proved very satisfactory.
•
The object of our invention is to produce or build up ivory synthetically of the
elements or materials which on analysis are found to constitute the natural ivory.
The invention consists essentially in forming or constructing an artificial ivory of
the same chemical constituents as natural ivory by chemically combining such
together under a great pressure and at a high temperature.
In carrying out the invention we take phosphate of calcium in a plastic state
(preferably formed by the addition of phosphoric acid to caustic lime) and add thereto
certain animal matters-(gelatine and albumen) calcium carbonate, magnesia and
alumina, and intimately mix the whole together so that a chemical combination niay
take place. The whole mass after proper desiccation is subjected to a high degree of
heat and compressed at a great pressure in suitable moulds and the resultant product
is left to season or mature. The calcium phosphate acting upon the gelatine and
albumen, converts the whole compound into a hard tenacious insoluble white body,
similar to natural ivory in physical properties and in chemical composition. It can
be turned, drilled, and polished in the usual way.
Pigments or other colouring matters as well as gum, suitable oils, or inert substances,
may be incorporated with the compound according to the article desired to be produced
without materially departing from our invention.
Ooted this 3rd day of June 1880
WM. P. THOMPSON & Co.,
6, Bank Street, Manchester, Patent Agents.
COMPLETE SPECIFICATION.
Improvements in the Manufacture of Artificial Ivory or Ivory
Substitutes.
We, ALEXANDRE DE PONT, and SILVIUS DE PONT, both of Paris, in the Republic of
France, but temporarily at the office for patents, 6 Bank Street, Manchester, in the
County of Lancaster, Manufacturers, HERBERT LUSHINGTON STOREY, and ISAAC
HENRY STOREY, both of Lancaster, in the County of Lancaster, Manufacturers, 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 invention relates to a new or improved substitute for natural ivory and to the

page_text: method by which we can construct artificially an ivory having the same properties,
component parts, and appearance as the natural product.
Hitherto inventions for the manufacture of substitutes for ivory have been based
upon the solidification of animal or vegetable substances with agglutinants or upon
subjecting such substances to heat in order to render them plastic and capable of being.
compressed or moulded into the required shape. The results of these different methods,
however, have not proved very satisfactory.
The object of our invention is to produce or build up ivory synthetically of the
elements or materials which on analysis are found to constitute the natural ivory, of
which a careful chemical analysis gives the following constituents :-
Tri-basic phosphate of lime, carbonate of lime, magnesia, alumina, gelatine and
albumen.
The invention consists essentially in forming or constructing an artificial ivory
having the same physical properties and of the same chemical constituents as natural
ivory by chemically combining the latter together under a great pressure and at a
high temperature.
In carrying out the invention we procure or prepare in as pure a form as possible.
each of the above mentioned materials in the required proportions. The solid bodies
either by mechanical means or by precipitation are reduced to a very fine state of
subdivision.
We first treat caustic lime (Ca O) with water sufficient to hydrate it and before the
hydration is completed and while the lime still remains caustic or retains some of its
causticity we carefully pour over it an aqueous solution of phosphoric acid (H, PO)
and mix the two well together for the purpose of forming phosphate of lime. During
this mixing there is added gradually a small quantity each of carbonate of lime
(Ca CO) magnesia (Mg O) and alumina (Al, O3) and then an admixture of gelatine
and albumen (dissolved together in water) or their chemical equivalents such as fibrine,
caseine, or vegetal fibrine, albumen, or caseine.
The proportions of the several materials by weight are about as follows to produce
a substance closely resembling in properties the tusk of an old elephant.
Caustic lime
Water
-
Phosphoric acid :-
aqueons solution of, specific gravity H, PO
1.05 to 1.07
Carbonate of lime
Magnesia
-
Alumina (precipitated or hydrated)
Albumen
Gelatine
Ca O
H₂O
->
100 parts
300
"
75
"
Ca CO,
•16
"
Mg O
1 to 2
"
"
-
20
"
15 "
The mass thus formed of these materials is mixed until the component parts are
thoroughly incorporated together and the whole is thoroughly kneaded until it assumes
a plastic condition of the consistency of stiff dough.
In this state it is allowed to stand for a few hours during which the continued
action of the phosphoric acid upon the other materials converts the whole into a fine
tenacious white insoluble and uninflammable body similar in its constituent parts to the
natural ivory. The compound while still in a plastic state is placed into shapes or
moulds and removed to a slow drying room (heated to a temperature of about 60°
to 70° F. or with a current of air passing through it) where it remains one or two
days until sufficiently desiccated. Care should be taken not to remove all traces of
moisture at this stage. When desiccated it may be taken from the drying room and
placed direct into moulds of a suitably constructed hydraulic or other press or may
be first finely ground and then placed in the moulds but we prefer the former
method.

page_text: The moulds into which the substance is placed are constructed so that it may be,
subjected to a high temperature and a great pressure. The heat may be produced
either by gas or steam acting upon the walls of the mould the latter being what we
prefer.
In the heated moulds the dried substance is subjected to pressure in an hydraulic or
other press amounting to one, two or more tons per square inch according to the
density of the product to be obtained and the pressure is maintained thereon from one
to two hours more or less according to the quantity of material under operation, the
greater the bulk of material the longer time must the pressure be applied.
The heat and pressure may be varied according to the quality and density of the
ivory required to be produced. We find that blocks closely resembling in physical
properties the tusks of an old elephant may be produced from the materials in the pro-
portions hereinbefore stated by applying a heat of about 270° F. with a pressure of
two tons per square inch applied for about an hour. By altering the heat, pressure,
or duration of pressure the density or specific gravity of the resultant product may be
varied as may be desired to render it more adaptable or serviceable for particular
purposes. The substance when taken from the moulds should be allowed to mature
and season for three or four weeks when it may be cut, turned, and polished in the
ordinary way.
We are aware that the product can be obtained without the application of heat
during the compressing stage of the process by increasing the pressure or the duration
of the pressure or both, and other details of the process may be varied without departing
from our invention, which is essentially to synthetically construct or manufacture
ivory having the same properties, chemical and physical, as the natural tusks with or
without the addition of any foreign matter to render the product more adaptable for
any special purpose.
While we prefer to use only the materials herein before enumerated as producing a
substance more nearly like natural ivory we find that other materials may be added
thereto such as baryta as a substitute for or in addition to magnesia; acetate or
carbonate of lead instead of or in addition to the carbonate of lime to increase the
specific gravity; oxide or sulphate of zinc to increase the bulk, or as an adulterant ;
and cellulose, and certain oils or gums such as animi, mastic, shellac, oil of turpentine,
and castor oil to render the product more plastic or elastic if so desired.
When colours are to be imparted to the product, aniline, alizarine, logwood, Brazil-
wood, fustic or madder extracts or other well known colouring agents such as pigments
may be incorporated with the mass in the earlier stages of the process in such
quantities or proportions as will give the required colour or tint.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :-
1. The artificial ivory or ivory substitute having substantially the same chemical
composition and physical properties as natural ivory, formed by treating the elements
or component materials which go to form natural ivory in the manner described and
subjecting the same to a great pressure while heated.
2. The process of manufacturing artificial ivory which consists in adding an aqueous
solution of phosphoric acid to lime thereby forming phosphate of lime; mixing there-
with finely divided earthy mineral matters such as described, and gelatine and
albumen allowing it to mature, desiccating the mass, and subjecting it hot to great
pressure, substantially as described.
3. The process of manufacturing ivory synthetically which consists in treating
caustic lime (Ca O) or hydrate of lime (Ca H, O₂) with an aqueous solution of
phosphoric acid (H3 PO) to form phosphate of lime, mixing therewith carbonate of
lime (Ca CO₂) magnesia (Mg O) precipitated or non-crystalline, alumina, gelatine

page_text: and albumen (with or without any other material such as described added for a
specific purpose) desiccating the mass, and subjecting it to a great pressure preferably
at a high temperature substantially as described.
Dated this 20th day of December 1889
WM. P. THOMPSON & Co.,
Manchester, Liverpool, and London, Patent Agents.