IMPROVEMENTS RELATING TO THE TREATMENT OF ALKALINE SILICATES AND OTHER MATERIALS AND TO THE FORMATION OF VARIOUS ARTICLES THEREFROM
Year: 1885

page_text: I, WILLIAM ROBERT LAKE, of the firm of Haseltine, Lake, and Co, Patent Agents,
Southampton Buildings, in the County of Middlesex do hereby declare the nature
of my invention for "IMPROVEMENTS RELATING TO THE TREATMENT OF ALKALINE
SILICATES AND OTHER MATERIALS AND TO THE FORMATION OF VARIOUS ARTICLES
THEREFROM and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement:—
:
"
This invention relates firstly to an improved process of treating alkaline silicates
based upon the discovery that turpentine, or its equivalent, with or without
camphor, may be used with good results, as hereinafter described; secondly: to an
improved process of treating alkaline silicates and to the resultant composition
and products, and has for its object the production of a material which may be
utilized in the manufacture of articles usually made of ivory and its substitutes;
and thirdly, to an improved process of treating silicate of soda in combination with
zinc oxide, and to the composition produced by such process, as hereinafter set
forth.
:
In carrying out the first part of this invention I take any alkaline silicate,
selecting by preference one having a minimum quantity of alkali. The silicate
being in solution I add a quantity of water, and after filtering the solution, reduce
it to such an extent that at a temperature of sixty degrees, it has a specific gravity
of about twenty-six degrees Baumé.
Of the solution just described I take, say, eight pounds, and if desired, add, say,
two pounds of any suitable oxide or inert material; the purpose of adding the
oxide or inert material being to give color, weight or finish to the article.
Having prepared a solution consisting of turpentine and camphor, in the pro-
portion of say, six parts turpentine to two parts camphor, I take of such solution
(where the quantities of silicate and oxide just referred to are used) say ten
ounces, which is added to the first mentioned solution.

page_text: The ingredients aforesaid having been brought together in the proportions
specified, are thoroughly mixed in any convenient way, after which the compound
is placed by preference on a water bath, and the aqueous particles evaporated until
they have been so far removed as to allow the material to be readily comminuted.
Before the comminution is attempted the compound is by preference, allowed to
become cool, when it is subjected to the action of a mill of any convenient kind, or
otherwise treated so as to be reduced to a very fine powder, after which it is ready
to be subjected to the action of the moulds. But to ensure a good result, it will be
necessary to ascertain whether or not the compound is in a right condition for
moulding. This may be determined by placing it in an evaporating pan and
stirring it continuously until it is in a condition in which it will not adhere to a
piece of polished metal under, say three hundred degrees (Fahrenheit) of heat, and
a pressure of say eight thousand pounds to the square inch. If the powder does
not attach itself to the polished surface of heated metal, and will weld together, it
is in a proper condition to be introduced into the moulds.
The dies employed are of usual construction and heated to a temperature of, say,
from about two hundred to three hundred degrees, Fahrenheit, and the material is
subjected to a pressure of about, say, two thousand pounds to the square inch,
more or less, according to the character of the article; the beat' and pressure being
continued until a complete solidification of the contents of the mould has been
accomplished.
The powder having been subjected to the action of the mould to form the
article, it is immersed in a bath, consisting preferably, of chloride of ammonium,
Bay, in the proportion of two parts water, to say, one part of chloride of ammonium,
for from ten to fifteen hours, or until a test will show no further alkaline re-action.
Upon the removal from the bath the article may be polished or it may be polished
before it is introduced into the bath.
It is important that great care be exercised in desiccating the material; the test
herein before mentioned, is believed to be a safe one, which may be relied upon
under ordinary conditions.
I prefer to use the ingredients herein before described in the proportions specified,
and to treat them in the manner set forth; but, as has been stated, the camphor,
and also the oxide or other inert material, may be omitted, and only the silicate and
turpentine, or its equivalent, made use of in the proportions herein before specified;
the process being substantially the same except that the silicate and turpentine
may be brought together in the manner herein before described, or in other ways,
if desired.
In specifying turpentine I have given it only as an example, as other resinous
substances having similar characteristics may be employed with substantially
similar results.
The bath too, may be varied according to circunstances; thus a bath consisting
of sulphate of lime or chloride of calcium may be used, the object being in all cases
to correct the tendency of the material under certain conditions to attract moisture
and to effloresce.
The proportions given are those which I prefer to make use of, although they
may be varied to some extent.
In relation to the second part of this invention, the process herein described is
based upon the discovery that alkaline silicates when properly desiccated and com-
minuted, may be successfully moulded to form articles of exceptional durability and
value. The silicate, with or without suitable oxides or other inert materials, is
subjected to heat and pressure when it is in a particular condition, as hereinbefore
described, whereby a new result is produced.
In practice I make use of any alkaline silicate, selecting by preference one
having a minimum percentage of alkali. The silicate being in solution I add to it
a sufficient quantity of water to enable a thorough filtration to be effected, and
reduce the filtered solution to such an extent that at a temperature of sixty degrees;
it has a specific gravity of about twenty-six degrees Baumé. Of the solution in

page_text: the condition just.stated, I take, say, eight pounds, and add to it, say, two pounds
of zinc oxide (or other metallic oxide, or inert substance, many kinds of which may
be used according to the quality of material desired) and mix the two ingredients
together as thoroughly as possible. I then place the mixture, preferably on a water
bath, and evaporate it slowly until the aqueous particles have so far been removed
as to permit the material to be comminuted, which may be effected by grinding or
otherwise; or the removal of the aqueous particles to the proper extent and tho
comminution of the material may be accomplished in other ways.
Before the comminution of the material is attempted, it is allowed to become
cool, when its reduction to a powder may be readily effected by means of a mill of
appropriate construction. The material is ground to an impalpable powder and by
preference sifted so as to ensure the production of a powder composed as far as
practicable of particles of relatively equal size. After the powder has been sifted,
it has been customary to put it in an evaporating pan and stir it continuously until
it is in a condition in which it will not adhere to the surface of the die under
the degree of heat and pressure required to weld it as hereinafter stated, say
a temperature of three hundred degrees Fahrenheit, and a pressure of eight
thousand pounds to the square inch, by which test the operator may ascertain
whether the proper degree of desiccation has been reached. If the powder does not
adhere to the die it may be concluded that it is in a proper condition.
The next step in the process consists in subjecting the powder, formed as herein-
before described, to pressure in heated. dies, whereby any desired article may be
formed. The dies employed are of usual construction. They are heated to a
temperature of say about two hundred and fifty to three hundred and fifty degrees,
Fahrenheit, or thereabouts, and the material is subjected to a pressure of about, say,
eight thousand pounds to the square inch, more or less, according to the character
of the article; the heat and pressure being continued until the contents of the mould
have been completely welded.
After the article is formed, it may be polished in any convenient way, when it
may be placed in a bath preferably of chloride of ammonium, consisting of, say,
about two parts of water and one part of chloride of ammonium, in which it is
permitted to remain from, say, ten to fifteen hours, or until a test shows, no further
alkaline reaction.
I prefer to use a bath of chloride of ammonium, but other baths may be used
with satisfactory results, the object of the treatment in the bath, being to correct
the tendency of the material to attract moisture and to effloresce. After the article
is taken from the bath it is thoroughly washed, when it is ready for use.
I do not wish to be understood as confining myself to any particular oxide or
inert material.
It is important that it be borne in mind that unless the material is reduced to the
proper degree of dryness without being completely dehydrated, the result will not
be satisfactory. The means I have described of ascertaining when the material has
been brought to the proper condition of dryness, is the best and most convenient of
which I am aware and if carefully observed, will enable the operator to accomplish
the desired result, without difficulty.
I do not restrict myself to the use of any alkaline silicate, or any oxide, inert
material, or coloring substance; and it is not essential that any oxide or inert
material be added to the silicate to produce useful results.
If an oxide, inert material, or coloring substance is employed, the proportions
which I have given, that is to say about four parts of the silicate to one part of the
inert material, may be used with satisfactory results; but it is not to be understood
that there can be no departure from these proportions, nor that other formulas
involving a use of other oxides or inert substances, cannot be made use of
'
In the third part of this invention, I take silicate of soda, which is made into
a solution, a sufficient quantity of water being added to enable a thorough filtration.
This solution I reduce to such an extent that at a temperature of sixty degrees, it
has a specific gravity of about twenty six degrees Baumé.

page_text: Of the solution of silicate of soda in the condition just stated, I take, say, eight
pounds to which I add, say two pounds of white zinc oxide and mix the two as
effectually as possible. I then place the mixture preferably on a water. bath and
evaporate it slowly until a sufficient part of the water has been removed to allow
the material to be comminuted. Before the commiinution is attempted the compound
is allowed to cool and is then ground to a fine powder by means of a inill of any
convenient kind, or reduced in any other way.
1
It is essential that great care be taken not to carry the evaporation too far. To
ascertain. whether the powder is in a proper condition to be subjected to the action
of the mould, I have been accustomed to press it upon a heated surface of polished
metal. If it is in such a condition that it will not adhere to the metal surface
when subjected to the degree of beat and pressure required to weld it, say
,a temperature of about three hundred degrees Fahrenheit, and a pressure of,
say eight thousand pounds to the square inch the proper degree of desiccation will
have been reached.
The material, having been brought to a condition in which it is ready to be
subjected to heat and pressure, is introduced into moulds of ordinary construction
and pressed to form the desired article.
1
:
The dies employed are of usual construction. They will be heated to a tem-
perature say, of from two hundred and fifty to three hundred and fifty degrees
Fahrenheit, or thereabouts, and the material is subjected to a pressure of about say,
eight thousand pounds to the square inch, more or less, according to the character
of the articles: the heat and pressure being continued until a complete consolidation
of the contents of the mould has been effected.
One of the chief difficulties connected with the utilization of alkaline silicates in
the production of articles of commerce, has been that after the article has been
completed, it attracts moisture and has a tendency to effloresce, to such an extent
as to destroy its value. To correct these difficulties is one of the principal objects
of this process and it is accomplished by the use of a bath of ammoniacal salts in
which the material is introduced after it is subjected to the action of the moulds.
In practice I prefer to immerse the completed article in the bath after it has
been moulded and polished. Having proceeded in the formation of the article as
herein before described, it is polished in any convenient way, and then introduced
into a bath consisting of say, two parts water to one part of chloride of ammonium
in which it is permitted to remain from, say, ten to fifteen hours, or until a test
shows that there is no further alkaline reaction.
Any of the ammoniacal salts may be made use of, and the strength of the bath is
varied according to circumstances.
It is not to be understood that this invention is limited to the exact proportion
of silicate and zinc oxide described, as they may be varied to some extent, or that
the employment of a bath of any particular strength is contemplated neither is
it limited to the bath for the treatment of the particular compound I have
described.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed I declare that what
I claim is
First. The process herein described of treating an alkaline silicate, which consists
(1) in forming a solution of the silicate, (2) adding thereto a resinous material, and
(3) comminuting the compound and subjecting it to heat and pressure substantially
as described.
Second. The within described process of treating an alkaline silicate, which
consists in forming a solution, adding thereto a resinous material and camphor,
and then desiccating, comminuting and moulding the compound, substantially as
described.
2 t
Third: The use of a resinous material for the purpose of facilitating the treatment
of an alkaline silicate, substantially as described.

page_text: Fourth. The use of a resinous material and camphor for the purpose of facilitating
the treatment of an alkaline silicate, substantially as described.
Fifth. The within described process of forming articles of an alkaline silicate
with or without an inert material, which consists in (1) forming a solution of the
silicate, and, if preferred, adding the inert material, (2) desiccating the solution, and
(3) subjecting the desiccated compound to pressure in heated moulds, substantially
as described.
Sixth. The within described process of forming articles of an alkaline silicate
with or without an inert material, which consists in (1) forming a solution of
silicate and introducing, if preferred, an inert material, (2) removing the aqueous
elements in part, (3) comminuting the compound (4) subjecting the desiccated
powder to pressure in heated moulds, and (5) subjecting the article to the action of
a bath, substantially as set forth.
Seventh. The within described process of forming articles of an alkaline silicate
with or without an inert material, which consists in (1) forming a solution of the
silicate and introducing if preferred, an inert material, (2) removing the aqueous
elements in part (3) comminuting the compound, and (4) subjecting the desiccated
powder to pressure in heated moulds, substantially as set forth.
Eighth. The within described process of forming articles of silicate of soda and
oxide of zinc, which consists in (1) forming an aqueous solution of the silicate of
soda with an admixture of zinc oxide in the proportion of about four parts of
silicate (twenty-six Baumé) to one part of zinc oxide (2) dessiccating and commi-
nuting the compound, and (3) subjecting the desiccated powder to pressure in
heated moulds, and (4) treating the article in an ammoniacal bath, substantially as
set forth.
Ninth. The use of an ammoniacal bath for the purpose of correcting the tendency
of an alkaline silicate to attract moisture and to effloresce, substantially as set
forth.
Tenth. The within described process of forming articles of silicate of soda and
oxide of zinc, which consists in (1) forming an aqueous solution of the silicate of
soda with an admixture of zinc oxide in the proportion of about four parts of
silicate (twenty-six Baumé) to one part of zinc oxide, and (2) desiccating the com-
pound, comminuting it, aud subjecting it to treatment in an ammoniacal bath,
substantially as set forth.
Eleventh. A composition consisting essentially of silicate of soda and zinc oxide,
combined, comminuted and partly dehydrated, substantially as set forth.
Twelfth. An article composed of an alkaline silicate and white zinc oxide com-
bined in the proportions and united by heat and pressure, substantially as set forth.
D
1 300-
HASELTINE, LAKE & Co.,
For the Applicant.