Improvements in or relating to the Production of Compounds applicable for such uses as for Paints, for Electric Insulating and Waterproofing, as Substitutes for Vulcanizable Rubber and Gum Compounds, and for other purposes.
Year: 1894

page_text: Improvements in or relating to the Production of Compounds
applicable for such uses as for Paints, for Electric Insulating and
Waterproofing, as Substitutes for Vulcanizable Rubber and Gum
Compounds, and for other purposes.
A communication by WILLIAM GRISCOM, Jr., of Bound Brook, in the County of
Somerset and State of New Jersey, United States of America.
I, WILLIAM PHILLIPS THOMPSON F.C.S., M.I.M.E., of The Agency for
Foreign Patent Solicitors, 6 Lord Street, Liverpool, and 6, Bank Street,
Manchester both in the County of Lancaster, and 31 High Holborn in the County
of Middlesex, Civil Engineer, 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 is based upon the discovery of the fact that the residual products
from the distillation of animal fats, oils, etcetera, can be combined with sulphur and
then developed into a vulcanised mass, possessing some of the elastic and other
desirable characteristics of vulcanised caoutchouc or rubber compounds.
The residual products referred to may be embraced within the meaning of the
well known term "candle tar"; although said products vary quite widely in their
character according to the mode of distillation involved in their production. In
some cases animal fat candle tar is quite soft and ropy, and especially when resulting
from steam distillation and without the use of acids, or alkalies and it is from the
use of that particular form or animal fat candle tar, that the best results will
accrue.
In other cases the animal fat candle tar is quite solid and hard, and there are
many intermediate grades and all of them can be used with more or less satisfactory
results, but, as a rule, in using the hard forms, they should first be rendered
comparatively soft, either by compounding them with the specially soft forms, or
with the last or heavy distillate which is evolved from the still, next prior to a
delivery of the residual product. As distinguished from such residuum pitches as
are obtained from the distillation of vegetable oils, the animal fat candle tar,
possesses peculiar and specially valuable capacities for practically resisting the
destructive action of acids and alkalies as well as resisting deterioration by
oxidation, as when long exposed in the open air, to light, heat and frequent wetting
and drying.
In the production of the compound, the procedure will be varied according to
the uses to which it is to be applied. For producing it in bulk, the animal fat
candle tar is heated sufficiently to develope by melting a high degree of liquefaction;
in the meantime the sulphur is heated to a completely melted and well liquefied
condition, and then the two elements are mixed intimately while slowly raising the
temperature of the mass to about 300° to 325° F., after so maintaining it for say
The resultant mass will be
from thirty minutes to an hour, it is allowed to cool.
sometimes more or less honeycombed in appearance, but the main portion thereof
will be quite solid, and if when still quite hot it be transferred to a mould or
cylinder and subjected to piston pressure, it will cool into a comparatively solid
elastic mass. The proportion of sulphur to the candle tar may be quite widely
varied, but the best results have been secured by the use of from one to three
ounces. of sulphur to each sixteen ounces of the candle tar, but the variable

page_text: character of the latter, renders it necessary to make preliminary tests of proportions
in small quantities for securing its satisfactory production in mass.
For use in the manufacture of paint, the vulcanised compound will be in its most
desirable form when well honeycombed or cellular, because of the greater facility
with which the solvents may attack it, and although some of the lightest volatile
hydrocarbons will serve as solvents, the most desirable solvent known to my
correspondent is the light oil from coal tar, not only because of its comparatively
low cost, but it is a thorough solvent, quite prompt in its action, readily maintains
the vulcanised matter in solution, and serves as a thoroughly practical vehicle for
making the compound as a paint.
Variations in compounding and vulcanising the candle tar, or in compounding it
with the vehicle, will involve no departures from the present invention, which,
broadly stated, includes any suitable solvent or vehicle, and elastic vulcanised
animal fat candle tar. It also includes with a similar solvent or solvents,
vulcanised compcunds in which such candle tar is an essential or ruling element as,
for instance, that hereafter described which includes as an ingredient a residuum
from the distillation of petroleum, and preferably that quite solid type thereof
which is normally hard and frequently friable at and below a temperature of
say 70° F. Suitable vulcanised compounds may be produced by the use of from
ten to fifty per cent. of the petroleum product, with the candle tar and sulphur,
the latter ranging say from five to fifteen per cent. of the mass, the mixing and
vulcanising being substantially as before described, except that somewhat higher
temperatures may well be employed, as for instance, at say 380° or 390° F. This
resultant is quite close grained or solid, and quite elastic and tenacious. These
elastic vulcanised compounds having been developed in bulk forin, is described,
they are properly disintegrated or cut up into small pieces, and then combined with
a suitable solvent, but inasmuch as at the close of the vulcanising process, the
elastic mass is hot and more or less soft or liquefied, it can at once be combined
with the solvent. When the cold or hardened vulcanised compound is used it is
quite finely divided, and to each four pounds thereof about one half gallon of the
light oil derived from coal tar is added, the whole being within a strong, tight or
closed digester provided with a mechanically operated agitator and a steam jacket.
The mass is then hoated to a degree afforded by steam usually at about 65 pounds
pressure As a rule, about one hour of heating and agitation will secure a perfectly
formed solution, which, after it has cooled, is drawn off into suitable storage
vessels. This mode of operation is deemned preferable to combining the initially
vulcanised soft plastic mass with the solvent, but in both cases the digester with
heat and agitation will be necessary. The light oils from coal tar are preferred as
the vehicle for the paints, although the heavy oils from coal tar may be used, or
benzole and the naphthas as well as bi-sulphide of carbon. The elastic vulcanised
compound which contains only the said candle tar and sulphur affords a high and
specially valuable grade of paint, but a cheaper, although a very desirable grade is
afforded by the use of the compound which also contains the petroleum residuum.
It is to be understood that the elastic compound of animal fat candle tar and sulphur
constitutes the ruling element, and it is upon that element that my correspondent relies
for those durably elastic properties which impart to the paint one of its greatest
values, and that the addition thereto of the other plastic matters involves economy,
with, for some purposes, greater efficiency. It is also to be understood that the
vulcanised elastic compound of animal fat. candle tar and sulphur may be used with
the other plastic matters whether the latter be also vulcanised therewith, or added
during the forming of the paint.
When the vulcanised compound is to be applied to a sheeted foundation, such as
cloth, the latter should be passed through the heated, and still liquefied vulcanised
compounds, then promptly stripped of all that can be well removed, and then with
its surfaces thoroughly dusted the charged fabric is slowly passed between com-
pressing rolls, care being taken to prevent adhesion of the compounds thereto.
finally hardening, such fabric will be flexible and elastic within the normal limits of
On

page_text: the uncharged cloth, and rendered as durably waterproof as if rubber compounds
had been employed, and as it is believed such fabrics are less liable to deterioration
under ordinary exposures to temperature, air moisture and water.
In like manner
electric wires which have been first coated or jacketted with a braided or a woven
fabric may be passed through the heated mass of compound, then thoroughly
stripped, dusted and rubbed, and thereby developed into a grade of insulated wire
which is quite equal to such as embody vulcanised rubber compounds, and the
insulated wire can be produced at a cost far below that involved in the use of the
comparatively expensive rubber The preferred method of producing the vulcanised
compound differs from all prior methods, in that instead of combining sulphur in
its normal condition with the matter to be vulcanised, and then subjecting the mass
to heat, the matter is highly heated, the sulphur melted, then they are combined
and further exposed to heat, and for the first time in the charging or coating of
textile material with a vulcanisable compound, the whole is united after the
compound has really been vulcanised, instead of as heretofore applying vulcanisable
guin compound to textile material, and then vulcanising the compound. It is
however to be understood that my correspondent is aware that soft animal fat
candle tar and powdered sulphur may be well triturated under a temperature far
below the melting point of sulphur, and then applied to a foundation fabric, and the
whole then exposed to vulcanising temperature, and the vulcanised compound so
produced is intended to be within the meaning of the present application, and
therefore a vulcanisable or vulcanised compound of animal fat candle tar and
sulphur constitutes the main feature of the invention, in that it is a vulcanisable
compound whether developed at once and in bulk into a vulcanised compound, or in
such form that it may be first applied to a foundation fabric and then developed
into a vulcanised compound. The compounds of sulphur and animal fat candle tar,
both prior to and after vulcanisation, may be employed to good advantage in com-
pounds containing rubber, and the metallic salts, and such earthly bodies as are
usually compounded therewith, and especially in such connections as demand
greater economy than would result froin the use of rubber as the sole elastic
medium.
My correspondent has also succeeded in producing a compound which is specially
resilient and tenacious, and instead of increasing the cost as compared with a
compound containing only the prime elements, animal fat candle tar and sulphur, he
has greatly reduced its cost and adapted it to service in many connections, as an
effective substitute for the well known expensive vulcanisable rubber or gum
compounds. This vulcanisable compound contains animal fat candle tar and
sulphur, and in its best form those bodies are combined with the hard or com-
paratively hard residual products from the distillation of petroleum, and inasmuch
as said products vary in accordance with various methods of distillation, and are
variously designated, it can only be said that my correspondent has found none of
said products which would not afford fairly good results in this connection, but that
the very best results will accrue from the use of those forms which are normally
hard and are friable under temperatures say at or below 70° F. and which require a
comparatively high temperature, say at or above 250° F. for reducing then to a
properly liquefied or suitable condition for his purposes. Refined sulphur is
preferred, but the cruder forms thereof may be employed. The compound may be
produced in many forms varied because of different proportions, and also because of
the many variations in the character of the animal fat candle tar, and the petroleum
residuum, and in some cases 90 parts of such candle tar has been used with ten of
the petroleum residuum, these proportions have been reversed and many intermediate
variations have been tested with sulphur in from 5 to 15 per cent of the inass.
a rule, the animal fat candle tar and petroleum residuun should be equal in quantity
when both are exactly suited to each other, and about six per cent. of the weight of
the mass will indicate the proper proportion of sulphur. With the two inain
elements of corresponding equal fitness and with the said candle tar in less pro-
portion than that indicated, the resulting compound will be liable to be weak and
As

page_text: In
below a desirable standard, and if the said candle tar be in excess, the character of
the compound will not be sufficiently improved for most purposes to warrant the
additional cost, although for some purposes, the said comparatively expensive candle
tar is employed in as high a proportion as from 75 to 85 per cent of the mass.
producing the compound in a form adapted to a wide range of use, the following is
the procedure-Forty-seven pounds each of animal fat candle tar in its soft and
ropy forin, and petroleum residuum in its hard form, friable at say 64° F. are
placed in a suitable stean jacketted kettle, and reduced to a well liquefied condition
under a temperature of about 300° F. Six pounds of sulphur previously melted
is then poured into the kettle and well mixed with the other elements, the
temperature being meantime, say during about thirty minutes, slowly raised
to about 345° F. During the latter part of this period, the mass will
foam freely under the evolution of gases, whereupon the temperature is raised
as rapidly as may be practicable to a temperature of say 380° or 390° F
in due time a subsidence of the foam will occur, and this will indicate the close of
the vulcanisation process. If lower temperatures must be employed, a longer time
will be involved in the operation. If the vulcanised compound is to be developed
in bulk, it is allowed tocool and then cut into suitable blocks or lumps, but if it is
to be incorporated with or applied as a coating, or moulded, it should be promptly
worked during its still heated and plastic condition for securing the best results,
although it may for so me purposes be subsequently worked into compounds
containing other materials, and somewhat after the manner of working crude
rubber. The vulcanised compound thus produced in bulk is dark coloured,
frequently very black, quite heavy and solid, quite tenacious in its elasticity, but
slowly resilient, and as a rule is almost absolutely odorless. When applied to
sheeted fabrics in its plastic condition, it is as a rule essential that the coated
surfaces be well stripped and dusted during the compression of the fabrics, as by
passing it between cool or slightly heated rolls or scrapers.
It is to be understood that the compound may be developed by modes of
procedure other than those indicated, without departure from the invention. As,
for instance, if the compound is to be vulcanised after its application to objects of
which it is to form a permanent part, and which may be safely exposed to the
requisite heat, the procedure is as follows:-After melting the two main components,
one-half the usual charge of sulphur is added thereto, and the mass subjected to
less heat, and for a shorter time than by the method before descubed, the object
being to develop the mass into one which after it has cooled inay at any time be
ground or triturated with powdered sulphur, in weight equal to or a little greater
than that initially employed, and then after application to the cavities or surfaces
of the objects to be treated, subjecting the whole to proper heat, say from 350 to
400 within a suitable chamber or retort until the final vulcanization is completed,
and in such cases the compound will be improved by the addition thereto, during
trituration, of small quantities of litharge, or zinc oxide, as well as other of the
well known ingredients employed in vulcanizable rubber compounds. One of the
most valuable uses to which the vulcanized compound may be applied is as already
stated in the production of a paint admirably suited for insulation, in any of the
various connections whether electric or therinal, or with respect of moisture, and
said compound carried by or with a suitable vehicle or solvent In this latter
connection, it may be stated that when the main elements of the compound have
been worked, with a small proportion of sulphur, and imperfectly vulcanized, the
resulting mass may be formed into a thick heavy solution, as with the light oils
from coal tar and bi-sulphide of carbon for instance, and a proper proportion of
flour of sulphur added, say from two to four per cent., with or without metallic
oxides, such as lead and zinc, and then after applying two or more coatings thereof
to the surfaces of cloth, or metal, the coatings of compound inay be vulcanized by
the slow application of heat, up to say from 350° to 400° Fahrenheit, and kept at
that temperature for from say fifteen to sixty minutes, and sometimes longer, and
then allowed to cool gradually.

page_text: The compounds may also be used in the production of hard but flexible insulating
plates which are backed or reinforced by one or more layers of paper or cloth.
About 95 parts of candle tar, and five parts of sulphur are separately melted, and
then united and well mixed under a gradually raised temperature to about 345° F.
Finely powdered coal or plumbago, with about five per cent. of its weight in lamp
black, is well warmed and mixed while dry, and the quantity of this solid matter
must be in excess of that which will be required in any one batch of the compound,
because the proportion of the solid inatter inust in each instance be determined by
the capacity of the soft compound to operate as an adhesive inedium. The candle
tar is not uniforın, and inasmuch as it varies with respect of its adhesive capacity,
the solid matter is to be gradually added to the adhesive matter, and well triturated
or mixed until the mass is quite stiff and not specially clingy or adhesive. Meantine
finely powdered sulphur can profitably be added, in quantity seldom if ever
exceeding the quantity which was initially melted and merged with the candle
tar. While the compounded mass is still hot, it is placed in suitable well
heated moulds, smoothly lined with paper, levelled and surmounted with another
sheet of paper. Several of the filled moulds are piled together and clamped, and
the whole is then subjected to a temperature of from 380° to 390° F. for from six
to twelve hours, and sometimes longer, this depending upon the thickness of the
paper, the character of the moulds, and the thickness of the moulded plates. These
plates when cold on being properly lined or scored, can be readily broken into
various desired forms, and they can be worked into any desired shape. A stronger
and less expensive plate will be afforded by the use of equal parts of petroleum
residuum and candle tar and sulphur in the proportions stated, and worked in the
manner before described. In the production of plates of considerable thickness,
the use of the previously vulcanised compounds is preferably employed. As, for
instance, after either of the two adhesive compounds described have been slowly
raised to say 345° F. it is then rapidly heated up to say 380° or 390° F., and mean-
time the mass will foam freely under the evolution of gaseous matter, and when the
foaming has subsided the heat is slowly withdrawn, and the mass allowed to cool
into an elastic and comparatively solid condition This elastic vulcanised compound
is then cut into small pieces and mixed within a tight digester with light oil froin coal
tar, during the application of heat and mechanical agitation. After cooling, the
resulting product is an adhesive paint compound which is used as an adhesive
medium with finely divided solid matter as described, the two being in proportions
which must of necessity vary in harmony with the viscosity of the paint compound,
and the absorbent or retaining character of the solid matter, but in this mode of
procedure, as in the others, a further addition of powdered sulphur is made at the
time of working in the solid matters, and the vulcanisation is effected as before
described.
In the production of moulded articles, well known precautions against adherence
to the moulds must be employed, such as dusting with foundry facings, or other
finely comminuted matter, or a wiping of the surfaces with vaseline, or the use of
metal foils, or thin paraffined paper. In the producton of moulded articles of
considerable bulk it is sometimes preferable to omit the powdered sulphur in the
mass during its final developinent, and to increase the initial quantity in the melted
mass, in which it need seldom exceed ten per cent. of the weight of the mass, and,
as a rule, six or eight per cent. will secure highly satisfactory results.
It will be readily seen that the solid matter may be almost indefinitely varied as
to its character, and it is to be understood that in many cases oxides of lead and
zinc may be employed, as when special solidity or density is desired, and whiting
or chalk barytes, clays, soapstone, and powdered asbestos, and, for some purposes,
paper pulps, both wood and rags. When designed for use in connections involving
exposure to acids etcetera, or for service in the open air, my correspondent's hard
vulcanised compounds should contain animal fat candle tar as the main or entire
adhesive element, and the solid matters combined therewith, should be such as would
best resist oxidation and the action of acids.

page_text: It will readily be seen that the proportion of sulphur to the inass may be quite
widely varied, as a rule six per cent. in weight need never be exceeded, and if inore
than eight or ten per cent be used, much of it will serve no good purpose, and cause
efforescence in the vulcanised compound In the production of the vulcanised
compound for use in paints, as low as two per cent. of the sulphur is sometimes used
but as a rule the best results will be attained by the use of about six per cent., with
a preference generally for a lesser proportion than a greater.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, as communicated to me by
my foreign correspondent, I declare that what I claim is :-
1. A vulcanisable compound composed of (animal fat) candle tar and sulphur,
substantially as described.
2. An elastic compound consisting of (animal fat) candle tar and sulphur hardened
by vulcanisation substantially as described.
3. A painting compound, composed of an elastic vulcanised compound of animal
fat candle tar and sulphur, and a suitable solvent or vehicle.
4. In a painting compound, elastic vulcanised animal fat candle tar, as an essential
element, combined with such plastic inatter as the residual products from petroleum
distillation, and a suitable solvent or vehicle.
5. A vulcanisable compound substantially as herein before described consisting of
such plastic matter as the residual products from the distillation of petroleum and
animal fat candle tar, in proportions which will secure desired strength, and
elasticity in the compound after vulcanisation, and sulphur in such proportions as
will insure vulcanisation
6. The vulcanisable compound hereinbefore described, composed of substantially
equal parts of animal fat candle tar and a residual product from petroleum
distillation, and sulphur, in proportions of from two to eight per cent. of the mass.
7. A hard vulcanised compound, containing candle tar as a vulcanisable adhesive
element, sulphur and finely divided solid matter, substantially as and for the purposes
specified.
8. A hard vulcanised compound, composed of candle tar, sulphur, petroleum
residuum, and finely divided solid matter substantially as described.
Dated this 26th day of November 1894.
WM. P. THOMPSON & Co.,
Agents.