IMPROVEMENTS IN VULCANIZED KERITE COMPOUNDS AND IN PROCESSES FOR THE MANUFACTURE OF THE SAME
Year: 1885

page_text: for the Manufacture of the same.
I, HERBERT JOHN ALLISON, of the firm of Allison Brothers, of 52 Chancery Lane,
London, in the County of Middlesex, Patent Agents, do hereby declare the nature
of said invention for "IMPROVEMENTS IN VULCANIZED KERITE COMPOUNDS AND
IN PROCESSES FOR THE MANUFACTURE OF THE SAME," (a communication to me
from abroad. by Austin Goodyear Day, of the City and County of New York, in
the State of New York, and United States of America), and in what manner the
same is to be performed, to be particularly described and ascertained in and by
the following statement :-
Several letters patent have heretofore been granted in Great Britain for inven-
tions made by the said Austin Goodyear Day pertaining to the vulcanized products
termed by him Kerite or Artificial Caoutchouc, especially letters patent number 36
of the year 1878, and the present improvements consist in substituting new
ingredients for a part or for the whole of the sulphur heretofore employed in the
manufacture of the preliminary vulcanized compound of vegetable oils, coal-tar or
bitumen, and sulphur, which has been termed by the said Austin Goodyear Day
"Crude Kerite" and which is generally afterwards mixed with india rubber
whereby a much more intimate chemical union of the substances composing the
compound is insured that it has hitherto been possible to obtain and, in con-
sequence, there are imparted to the crude kerite improved qualities of the greatest
practical importance.
•
The combination of the said vulcanized crude kerite with india rubber in accord-
ance with the aforesaid letters patent of 1878, is especially adapted for telegraphic
and other insulation, the india rubber furnishing the insulating properties and the
Kerite imparting to the combination unequalled durability and capacity to resist
destructive agencies.
In the manufacture of the Kerite.on a commercial scale, however, the said
Austin Goodyear Day has always heretofore encountered much difficulty-and often
great loss-on account of the tendency of the sulphur, in consequence of its rapid
action when or after it begins to combine with the oils, to suddenly generato
chemical heat of such intensity as to "cook" or overheat the compound and either
entirely spoil the batch or seriously impair its value. This danger is referred to in
the said 1878 patent and the use of wax and some other substances is described as
obviating it.
After experimenting for a considerable period, however, the said Austin Good-
year Day has discovered that by the substitution of other ingredients for a part, or
in some cases for the whole of the sulphur, he can control the action of the heat in
a surer and more satisfactory manner than by the use of wax or its equivalents,

page_text: and, as stated above, by reason of the more thorough chemical union of the oils and
the tar which is thereby effected he is able to produce a crude Kerite of much
better quality than he has heretofore made, and to impart to it so great durability
and cohesiveness as in the former respect to largely increase its usefulness for all
purposes, and in the latter respect to especially add to its value for mixing with
india rubber and in some cases for employment as a substitute for the rubber
itself.
The method by which the said Austin Goodyear Day accomplishes this result is
simple. He adopts the same mode of treatment as is described in his said 1878
patent, and follows it until the point is reached at which in that process the
sulphur is introduced. That is to say, he first mixes the cotton-seed oil and coal-
tar or bitumen together in a suitable kettle or boiler under sufficient heat and for
a sufficient length of time to cause them to unite together freely and thoroughly.
The temperature ordinarily required for this purpose will be about 300° to 330°
Fahrenheit, and the time generally from three to five hours. The mixture is then
cooled down to, say, from 200° to 220°, or sometimes to 240° Fahrenheit, or there-
abouts and then the linseed-oil may be added. To obtain the best result, however,
the said Austin Goodyear Day prefers to let the cotton-seed oil and coal-tar or
bitumen stand over night to cool. If this latter course be adopted they will be
found in the morning to be thoroughly combined, and he then heats them up to the
above specified temperature of from 200° to 220°, or sometimes 240° Fahrenheit, and
then adds the requisite quantity of linseed-oil. When the linseed-oil has become
thoroughly incorporated with the other ingredients, which usually takes about one
to two hours, and which is the stage of the said Austin Goodyear Day's 1878
process at which he adds the sulphur, instead of introducing sulphur in the propor-
tion called for by the said 1878 process, he preferably reduces the amount of it
about one-half and substitutes for the omitted portion an equal quantity of the
sulphide of antimony, and introduces the latter together with the remaining sulphur
into the mixture in the same manner as in the said 1878 process, that is, preferably
commencing to add it when the temperature of the mixture is about 230° Fahren-
heit, and introducing it gradually and then as it combines with the other ingredients
he usually raises the temperature to about 275° to 300° Fahrenheit, or in that
vicinity, the degrees of temperature depending largely upon the length of heating-
time employed. The heating of the compound may be continued until vulcanization
of the mass takes place, say, in the case of a usual working batch of about one
hundred pounds, for from three to five hours, or sometimes longer. When the
vulcanization is complete the compound is finished, and it may then be poured into
moulds or pans of any desired dimensions, and allowed to cool for use or for the
market.
As in the mode of treatment set forth in the said 1878 patent, cotton-seed oil,
linseed oil or other equivalent vegetable oils, and bitumen or coal-tar or the
equivalents for the latter described in said patent, are essential ingredients of the
present process, and as stated in that patent their proportions may be greatly
varied, but the same proportions there specified are recommended here as adapted
to produce a compound suitable for most ordinary purposes, to wit:-twenty-seven
pounds of cotton-seed oil mixed with say twenty pounds of coal-tar or fifteen to
twenty-five pounds of bitumen, to which may be added twenty-seven pounds of
linseed-oil and from six to eight pounds or thereabouts of sulphur and the same
amount of the sulphide of antimony.
Instead of sulphide of antimony, other sulphides, such as the sulphide of zinc,
lead, iron or copper, may be employed in a similar manner and with beneficial
results. In fact, the sulphides of nickel, cobalt, silver, aluminium etc., might be
used, but for the reason that their cost renders them impracticable.
.
In practice, whenever desired, gum camphor, as well as sulphuric, nitric or
muriatic acid, or oxide of iron, may be added to the present compound in the same
manner as described in the said 1878 patent, but the proportions in which they are
used should preferably be considerably larger than there specified.

page_text: It will be found to be an important result of using sulphides as herein described,
that as they are stable compounds they greatly tend to prevent oxidation of the
Kerite after it is manufactured.
Instead of retaining about one-half of the sulphur as recommended, the whole of
it may, if preferred, be dispensed with and the sulphide of antimony or other
sulphide substituted for it, care being taken in such case to use about enough of the
latter to make the sulphur in it equal to that which in its other form is omitted.
This plan, however, will be somewhat more expensive and will not present com-
pensating advantages, and the said Austin Goodyear Day has obtained equally good
or better results when proceeding as above directed.
He is aware that various sulphides have been employed in the manufacture of
india rubber goods. But when so used, it has been for a different purpose from
that for which ho employs them, and they have produced a very different result.
Moreover, in that use they obviously have not been combined with substances in
the least resembling those with which he combines them in his crude Kerite.
It may at first appear that the substitution of sulphides for a part or for the
whole of the sulphur of the said 1878 process, does not constitute a substantial
novelty. But in that process the sulphur is used almost solely as a vulcanizer, and
instead of acting in any respect as a controller of the chemical heat, it is the cause
of that heat and hence is constantly liable to produce injury and loss, and therefore
requires to be itself controlled. The sulphides, on the other band, not only perform
the vulcanizing function of the sulphur, but in addition serve as the heat controller,
an office which, as stated, it is impossible for the sulphur used alone to fulfil. They
also aid in preventing oxidation of the finished product. The application of the
sulphides for these purposes is believed to be entirely new.
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 above described new process of making vulcanized crude Kerite, con-
sisting in first mixing together and beating cotton-seed oil and coal-tar or bitumen,
and afterwards adding linseed-oil and sulphide of antimony or other suitable
sulphide, the latter either alone or united with a greater or less proportion of
sulphur in the ordinary form, substantially as set forth.
Second. In any compound designed to form crude Kerite or analogous products,
the mixture of sulphide of antimony or other suitable sulphide either alone or
united with a greater or less proportion of. sulphur in the ordinary form, in such
manner as to enable the chemical heat of the mixture to be controlled by the
sulphide, substantially as described.
Third. In any compound designed to form crude Kerite or analogous products,
the mixture of sulphide of antimony or other suitable sulphide either alone or
united with a greater or less proportion of sulphur in the ordinary form for the
purpose of aiding in preventing oxidation of the finished product, as set forth.
Fourth. The within described new product consisting of a crude Kerite compound
formed by the mixture of cotton-seed oil, linseed-oil, coal-tar or bitumen and the
sulphide of antimony or other suitable sulphide, substantially as set forth.
D