Improvements in or connected with the Obtaining of Gutta Percha.
Year: 1897

page_text: Date of Application, 26th Aug., 1897
Complete Specification. Left, 26th May, 1898-Accepted, 2nd July, 1898
PROVISIONAL SPECIFICATION.
Improvements in or connected with the Obtaining of Gutta Percha.
We, RICHARD JOHN FRISWELL, a Vice-President of the Institute of Chemistry,
Fellow of the Chemical Society, and a Manager and Director to Brooke, Simpson
& Spiller, Ld., and the said BROOKE, SIMPSON AND SPILLER LIMITED, Chemical
and Dye Manufacturers, both of Atlas Works, Hackney Wick, in the County of
Middlesex, do hereby declare the nature of this invention to be as follows:-
This invention relates to the obtaining of the substance called, or known as
gutta percha," and the object of the invention is to effect improvements in the
process employed for obtaining such substance by methods depending upon the
crushing, or grinding of the leaves, twigs, bark, wood and other parts of gutta
percha containing plants, the removal of vegetable matter, other than cellulose
and gutta percha therefrom by means of caustic soda solution, and the extraction
of the gutta percha from the dried substance, obtained by the above mentioned
treatment, by means of a new solvent, viz.: bisulphide of carbon, which may be
used cold, or hot, and in the form of liquid, or of vapour condensing upon the
matter from which the gutta percha is to be extracted, as may be the most con-
venient and desirable.
In employing our said new solvent bisulphide of carbon, we find that alcoho!
is of no use as a precipitant, with which to treat the resulting solution of gutta
percha, and we therefore precipitate with the substance, well known to chemists
and manufacturers of chemicals as acetone.
In place of precipitation, since bisulphide of carbon evaporates with great ease
and at a low temperature, the gutta percha may be obtained from the solution, by
evaporation of the solvent, with or without the use of a vacuum, according to
methods well known and practised in performing similar operations, viz., the
recovery of dissolved substances from volatile solvents thereof.
Where objects requiring to be coated with gutta percha are of irregular form,
or, for any reason, may be conveniently coated by the application of a solution,
the solution of gutta percha in bisulphide of carbon is very suitable to be employed
for such purposes.
As an example of the method of carrying our invention into practise, we treat
the leaves, twigs, wood, chips, roots and other parts of gutta percha containing
piants with caustic soda and water, wash and dry the insoluble residue, and digest
the same in hot, or cold bisulphide of carbon in closed vessels, or we distil the
vapour of bisulphide of carbon into vessels packed with the substance resulting
from the above mentioned caustic soda treatment and previously dried, the said
vessels being maintained at such a temperature, that the said vapour condenses
upon their contents, penetrates and extracts from them the gutta percha, and flows
away with it back into the same vessel from which it was distilled, or into another
vessel, as may be more convenient.
The resulting solutions of gutta percha in bisulphide of carbon, are then, if
necessary, concentrated by distilling off part of the solvent by any convenient
mathed

page_text: The solution, whether concentrated or not, is precipitated by the addition of
acetone, and the gutta percha thrown out, is finished for use by removal of the
traces of solvent and precipitant adhering to it, by washing, preferably with
alcohol, and heating or boiling with water, maceration and drying in the usual
manner.
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Improvements in or connected with the Obtaining of Gutta Percha.
We, RICHARD JOIN FRISWELL, a Vice-President of the Institute of Chemistry,
Fellow of the Chemical Society, and a Manager and Director to Brooke, Simpson
& Spiller, Ld., and the said BROOKE, SIMPSON. AND SPILLER, LIMITED Chemical
and Dye Manufacturers, both of Atlas Works, Hackney Wick, in the County of
Middlesex, 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:-
This invention relates to the obtaining of the substance called, or known as
gutta percha," and the object of the invention is to effect improvements in the
process employed for obtaining such substance from the leaves, twigs, bark, wood
or other parts of gutta percha containing plants. Such process consists in the
removal of vegetable matter, other than cellulose and gutta percha, therefrom,
by means of caustic soda solution, and the extraction of the gutta percha from the
dried substance resulting from such treatment by means of a new solvent, viz.
bisulphide of carbon, which may be used cold or hot, and in the form of liquid,
or of vapour condensing upon the matter from which the gutta percha is to be
extracted, as may be the more convenient and desirable.
In employing our said new solvent, bisulphide of carbon, we find that alcohol
is of no use as a precipitant, with which to treat the resulting solution of gutta
percha, and we therefore precipitate with the substance, well known to chemists
and manufacturers of chemicals, as acetone.
In place of precipitation, since bisulphide of carbon evaporates with great ease
and at a low temperature, the gutta percha may be obtained from the solution by
evaporation of the solvent, with or without the use of a vacuum, according to
methods well-known and practised in performing similar operations viz. the
recovery of dissolved substances from volatile solvents thereof.
As an example of the method of carrying our invention into practice, we take
the leaves, twigs, wood, chips, roots, or other parts of gutta percha containing
plants, grind or crush them, if they are not already in sufficiently small pieces,
and then heat them under pressure with caustic soda and water in a boiler, or
closed vessel of iron, or other suitable metal, provided with an agitator, or capable
of being rotated, or in any other way so arranged, that its contents are well stirred
and thoroughly agitated.
When a sample drawn from the vessel, shows that the softer organic tissues of
the materials have been decomposed, dissolved, or destroyed, and that only the
cellulose, or woody skeleton thereof, together with the gutta percha are left, the
contents are discharged from the vessel, filtered and washed free, or nearly so,
from soda compounds.
The resulting matter is pressed, centrifugated, or, in any other suitable way,
freed from water and dried.

page_text: Such dried matter is then digested in closed vessels with hot or cold bisulphide
of carbon, or the vapour of bisulphide of carbon is distilled into vessels packed
with the said dried matter, the said vessels being maintained at such a temperature,
that the said vapour condenses on their contents, penetrates and extracts from
them the gutta percha, and flows away with it back into the same vessel from
which it was distilled, or into another vessel, as may be more convenient.
The resulting solutions of gutta percha in bisulphide of carbon, are then, if
necessary, concentrated by distilling off part of the solvent by any convenient
method.
The solution, whether concentrated or not, is precipitated by the addition of
acetone, and the gutta percha thus thrown out is finished for use, by removal of
the traces of solvent and precipitant adhering to it, by washing, preferably with
alcohol, and heating or boiling with water, maceration and drying in the usual
manner.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what
we claim is:
1. In the preparation, or extraction of gutta percha; dissolving the gutta percha
out of the materials containing it, by means of bisulphide of carbon, and precipi-
tating the gutta percha from the solution in bisulphide of carbon so obtained, by
means of acetone, substantially as herein set forth.
2. The process for the preparation, or extraction of gutta percha, consisting of,
treatment of the parts of gutta percha containing plants with soda, washing and
drying, extraction of the gutta percha therefrom with bisulphide of carbon, precipi-
tation of the gutta percha from the bisulphide of carbon solution with acetone,
washing, and finally maceration and finishing, substantially as herein set forth.
3. As a new article of manufacture, gutta percha, prepared or extracted by
means of the process as herein described and claimed.
Dated the 26th day of May 1808
AMBROSE MYALL,
2, Lancaster Place, London, W.C., Agent for the Applicants.