Improvements in the Treatment of Old or Waste Vulcanised Rubber to render it capable of Re-use.
Year: 1898

page_text: Improvements in the Treatment of Old or Waste Vulcanised Rubber
to render it capable of Re-use.
I,' CHRISTIAN HEINZERLING, Doctor of Philosophy, of 46, Eiserne Hand,
Frankfurt-on-Main, in the Empire of Germany, Chemist, do hereby declare the
nature of this invention to be as follows:-
The object of this process is to convert chips, or scraps, of vulcanized rubber,
or articles thereof which have become unserviceable, or deteriorated into a con-
dition fit to be employed again. According to this invention the rubber to be
regenerated, or restored, is as finely divided as practicable and is dissolved by
means of heat in conjunction with aniline, toluidine, or xylidine; or their higher
homologues, either each by itself, or two or more mixed together. The dissolving
effect of these bodies upon vulcanized soft rubber has been disputed hitherto (sec
the Handwörterbuch der Chemie," vol. 1 p. 574). I have however found by ex-
periment that their dissolving power is greater than that of the solvents hitherto
used for dissolving india rubber and for the purposes of the present invention the
said new solvents have the additional advantage over the ordinary solvents, that
the new solvents are capable of being separated from the rubber solution far more
readily than can ordinary solvents.
"
The proportion in which the solvent should be added to the rubber varies accord-
ing to the nature and quantity of other ingredients or media there may be in the
rubber to be dissolved.
Comparatively pure waste rubber requires more solvent; whilst rubber contain-
ing large amounts of mineral matter may be treated with a less amount of solvent.
The proportion of solvent is to a certain extent dependent upon whether it is
desired, after having dissolved the rubber, to separate the mineral matter or not.
In the former case the solutions should be more fluid so that the mechanical pro-
cess of separation may be conveniently performed.
The rubber should be dissolved at a somewhat high temperature, say from 140°
to 180° Centigrade according to the quality of the material to be dissolved.
When the dissolving process is completed (and after the mineral ingredients
have been mechanically separated from the india rubber, or not, as the case may
be) the solvent and rubber are separated for which purpose a suitable acid (pre-
ferably hydrochloric or sulphuric acid) is added to the solution. The salts formed
by the solvent in conjunction with the acid will dissolve in the water which has
been added along with the acid, while the rubber will separate in the form of a
concrete mass.
Or there may be mixed with the solution a liquid capable of dissolving the sol-
vent employed, but incapable of dissolving the rubber. Among the agents that will
produce this effect wood spirit, amyl-alcohol, and the like are very suitable. .!
The rubber obtained by either of the methods hereinbefore described is sepa-
rated from the liquid, which collects at the top and is decanted and the said, rubber
then washed and dried.

page_text: Or, the solvent may be separated by distillation say in a chamber wherein the
air has been rarefied for the purpose; but this mode of separation however will
prove expedient only in exceptional cases.
111 1
eicne
JOHNSONS & WILLCOX,
47, Lincoln's Inn Fields, London, W.C., Agents.
Improvements in the Treatment of Old or Waste Vulcanised Rubber
to render it capable of Re-use.
I, CHRISTIAN HEINZERLING, Doctor of Philosophy, of 46, Eiserne Hand,
Frankfort-on-Main, in the Empire of Germany, Chemist, 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 object of this process is to convert chips or scraps of vulcanized rubber
or articles thereof which have become unserviceable or deteriorated into a con-
dition fit to be employed again. According to this invention the rubber to be
regenerated, or restored, is as finely divided as practicable and is dissolved hy
means of heat in conjunction with aniline, toluidine, or xylidine or their higher
homologues, either each by itself, or two or more mixed together. The dissolving
effect of these bodies upon vulcanized soft rubber has been disputed hitherto (see
the Handwörterbuch der Chemie," vol. 1 p. 574). I have however found by ex-
periment that their dissolving power is greater than that of the solvents hitherto
used for dissolving india rubber and for the purposes of the present invention the
said new solvents have the additional advantage over the ordinary solvents that
the new solvents are capable of being separated from the rubber solution far more
readily than can ordinary solvents.
The proportion in which the solvent should be added to the rubber varies accord--
ing to the nature and quantity of other ingredients or media there may be in the
rubber to be dissolved.
Comparatively pure waste rubber requires more solvent; whilst rubber contain-
ing large amounts of mineral matter may be treated with a less amount of solvent.
The proportion of solvent is to a certain extent dependent upon whether it is
desired, after having dissolved the rubber, to separate the mineral matter or not.
In the former case the solutions should be more fluid so that the mechanical pro-
'cess of separation may be conveniently performed.
The rubber should be dissolved at a somewhat high temperature, say from 140°
to 180° Centigrade according to the quality of the material to be dissolved.
When the dissolving process is completed (and after the mineral ingredients
have been mechanically separated from the india rubber, or not, as the case may
be) the solvent and rubber are separated for which purpose a suitable acid (pre-
ferably hydrochloric or sulphuric acid) is added to the solution. The salts formed
by the solvent in conjunction with the acid will dissolve in the water which has
been added along with the acid, while the rubber will separate in the form of a
'concrete mass.
Or there may be mixed with the solution a liquid capable of dissolving the sol-
vent employed, but incapable of dissolving the rubber. Among the agents that will
-produce this effect wood spirit, amyl-alcohol, and the like are very suitable.
The rubber obtained by either of the methods herein before described is sepa-
-rated from the liquid, which collects at the top and is décanted and the said rubber
is then washed and dried:

page_text: Or the solvent may be separated by distillation, say in a chamber wherein the
air has been rarified for the purpose; but this mode of separation however will
prove expedient only in exceptional cases.
Having now particularly described and ascertained the nature of this invention
and in what manner the same is to be performed I declare that what I claim is;-
1. Regenerating or restoring old or waste rubber by dissolving by means of
aniline, toluidine or xylidine, or their higher homologues, (either separately or in
any desired admixture) employed as a solvent in conjunction with heat and after
the solution has been completed, separating the solvent from the rubber.
2. In the process referred to in the first claim, separating the said solvent by
converting it by means of an acid, diluted with water, into an aqueous salt solu-
tion from which the rubber separates.
3. In the process referred to in the first claim, dissolving the solvent with wood
spirit, amyl-alcohol or other dissolvent for the solvent but in which india rubber
will not dissolve.
Dated this 3rd day of December 1898
JOHNSONS & WILLCOX,
47, Lincoln's Inn Fields, London, W.C., Agents.