Improvements in Treatment of Gum Copals, Gum Resins, and other Gums for the Manufacture of Varnishes and other Solutions for Coating Surfaces, and for other Uses.
Year: 1889

page_text: Date of Application, 17th Apr., 1889
Specification Accepted, 1st June, 1889
Improvements in Treatment of Gum Copals, Gum Resins, and other
Gums for the Manufacture of Varnishes and other Solutions for
Coating Surfaces, and for other Uses.
I, GEORGE HAND SMITH of 71 Edith Road, West Kensington, in the County
of Middlesex, Doctor of Medicine, 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 my process is to improve the quality of the aforesaid gums, and
their suitability for the manufacture of varnishes and other solutions for coating
surfaces and for other uses.
It is specially useful for the treatment of the harder or more insoluble gums,
as it reduces the gums to a state of increased solubility or tractability to the action
of solvents, and effects its object without exposing them to the action of heat except at
so moderate a temperature as not to be injurious to the said gums.
My invention consists in subjecting the said guns to the action of the vapours
of volatile solvents prior to their being dissolved in solvents of the same or like nature
to produce solutions of the gums. By this process they are rendered tractable to
the solvent action of the said solvent liquids.
To carry out my invention I expose the guns in a comminuted state in layers
upon perforated plates or reticulate surfaces or floors arranged at proper distances
apart in a chamber or chambers, which may be constructed of iron, or brick lined
with iron, which may be capable of supporting and containing large quantities
of the matters to be treated. The volatile liquids to be used are placed in shallow
trays, or other means of exposure, open above, (or so arranged as best to maintain
dispersion in vapour) placed beneath the perforated plates or floors, which are supplied
through proper pipes with suitable inlet and outlet taps. These trays are gently
beated to a temperature sufficient for setting up and maintaining the desired
D

page_text: vapourous atmosphere (and the heat is maintained uniform by the aid of thermometers
placed in the trays if necessary) so as to cause the vapour to fill the spaces in which
the gums are placed to act upon the guns until the action is complete.
The duration of treatment may vary from some hours to days, according to
quantity or other conditions of mass treated, the character of gums employed, or
product desired. The object to be attained, as before stated is to render the guins
more readily soluble in usual solvents suitably applied for manufacturing purposes,
without fusion or high and destructive heats as is general in varnish manufacture.
Gums treated by this process are rendered more soluble, whilst preserving brilliancy,
elasticity and quality and are especially improved for the manufacture of varnishes and
other covering products.
The agents employed with heat in these chambers are phenol or phenolic or derivative
bodies, creosol or creosylic acid or other coal tar distillates having solvent properties for
the gums, spirits of turpentine and methylated alcohol or analogous solvents of a volatile
character. It is not necessary that only one of these should be applied as they may be
used mixed or in succession provided that the solvents thus mixed or succeeding one
to the other are not of a kind to interfere with one another's solvent action.
Ordinarily for copals of difficult solubility the phenol vapours may be first employed,
and after penetration the phenol may be combined with or replaced by vapour of
spirits of turpentine or with vapour of alcohol or methylated alcohol-one or both.
The temperature ordinarily employed may be 200° F. or 212°, but will vary according
to the gum to be treated. Other things being equal, the higher the temperature the less
time required in the exposure of the gunis. So also, the harder or more refractory the
gums, the longer the time of exposure required. Generally the lower the temperature
the lighter the colour of the resulting gums. Experimental treatment on a sample
as described will readily show the proper limits of temperature and time suited to
particular qualities or specimens of gum so as to produce a required result. Or
samples may be drawn during the process and the process continued until the desired
result is obtained.
The vapour of phenol or the other named bodies is only required in small quantities,
as liquidity is afterwards chiefly effected by the spirits of turpentine, methylated
alcohol, oil or attenuating bodies.
One convenient arrangement for applying my method of treating the gums as above
described, (such as gum animi Sierra Leone and the like) is by subjecting them in a
comminuted state on perforated plates to the action of the vapours of spirits of
turpentine methalcohol and other analogous bodies as before described the vapours
being supplied from open horizontal tubes, arranged side by side directly beneath the
perforated plate, each open conduit being protected from the flowing gum by a
narrow roof, with space left between for the flow to run between the open tubes, and
drop from tray to tray so as to increase the exposure and consequent liquifying
action.
DESCRIPTION OF THE DRAWINGS.
Figure 1 shows a vertical sectional elevation of an apparatus adapted for carrying
out the present invention for the treatment of hard gums by subjecting them to
the action of the vapour of volatile solvents. This apparatus consists of a series of
trays or supports a, a', a³, a³, a, a, a, arranged one above another and each having
its bottom formed of open work, perforated plates or reticulate or woven wire-work,
upon which the gums to be treated are placed. These trays ride on supports a
projecting from the sides of the inner metal chamber as, which chamber is formed
with a door, preferably reaching from top to bottom of the chamber and formed
double, packed with non-conducting packing of a suitable or ordinary kind. This
door is not shown as it would be of ordinary construction, and simply provided
to give access to the trays, for renewing the supply of gum or otherwise.
b, b, b, b. b4, 6, 6º, are shallow trays adapted to contain and expose suitable liquid
for providing the vapour to act upon the gums on the trays above them. C 18 &

page_text: conduit or pipe of supply for the liquid supplied to the trays b, b¹, b², b², bª, bº, 6º,
by means of branches therefrom c¹, c², c², c¹, c³, c³, c², each branch having a
controlling valve c. d, d¹, d³, d³, d', d³, d, are pipes leading from the trays
b, b¹, h², b³, bª, b³, 66, and communicating with the conduit or pipe d³, each branch
being controlled by a separate valve d'. The metal chamber as is shown supported by
blocks or brick supports e which again are supported on the foundation from which
spring surrounding brick walls g. which support a roof h. i is an internal lining
supported some short distance within the outer wall g. The space k between. this
lining and the wall being packed with non-conducting packing so as to prevent as
much as possible the escape or variation of heat. is one end of a series of steam
pipes which pass around the lower portion of the chamber formed within the
walls a, g, and below the chamber as, so as to heat the contained atmosphere and
cause vapour to be evolved from the liquid in the trays b, 61, 62, 63, 64, 6º, 6º. After
the hard gums, broken up or reduced to suitable sized pieces in the trays, have been
submitted to the vapours at the desired temperature for a suitable time, they are
removed therefrom and are ready for further treatment in such a vessel as is shown
by Fig. 2.
Figure 2 is a similar view to Fig. 1 of an arrangement of apparatus, differing
somewhat in construction and arrangement and working from the apparatus shown in
the previous Figure, in which the further treating of the gums is carried on in order
to prepare therefrom varnishes or other coating solutions. In this Figure, m is the
inner vessel which may be of wrought iron bolted and otherwise constructed in the
usual manner, m¹-m¹³ are a series of surfaces of woven wire open work, perforated
plates or other reticulate material supported by brackets m" from the sides of the
vessel m.
n are a series of troughs open at the top, running across the chamber, and
which at each end are connected to and communicate with a cross channel closed on
all sides except where it communicates with these longitudinal open channels.
a series of covers, arranged above the open troughs n, to prevent drip thereinto.
These longitudinal troughs are supported by the transverse end channels, which again
are supported from the side walls of the containing vessel m. p are inclined sides to
the vessel leading to the exit channel p¹ and exit pipe p², provided with a suitable
valve.
o are
Between this inclined bottom p, and the bottom of the chamber m, may be applied
an open vessel p³ for liquid. Drip through the openings p' from the contents of the
chamber m is prevented by guards p³. The supply of liquid to the open troughs n is
maintained and regulated by means of the main channel r, subsidiary channels 1,
each controlled by a valve, and like subsidiary pipes each controlled by a valve b
communicating with exit pipe 7º. s shows a portion of a series of steam pipes
passing around the lower part of the chamber formed around the inner chamber m by
the inner lining t, between which and the outer wall u in the space t' is contained a
suitable non-conducting packing material. v is the foundation, v¹ the bricks or blocks
for supporting the chamber m.
In operation the gum produced in the preceding apparatus is introduced through
the opening w and channel w¹ (or by an opening w), into the chamber m, on the
upper reticulate floor m', where it is acted upon by vapours produced from the liquid
in the open channels n, under the influence of heat provided by the steam pipes s.
The gums becoming dissolved by the vapour drip through the reticulate surface m' are
again caught and detained by the surface m³, then pass on through that onto the next
surface m³, and so on, each reticulate surface detaining and further exposing the now
solving gum, until at last it falls onto the inclined surface at the bottom, to be run
off.
Although I have in the foregoing description and in the drawings, alluded more
particularly to apparatus wherein the vapour is generated directly, such vapour may
be introduced from another chamber in which the generation is effected, but prefer
to generate the vapour within the apparatus itself on account of the economy of heat
more direct and effective action of the vapours and other advantages.
The operation may be repeated if required.

page_text: Having now particularly described and ascertained the nature of my said Inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
1. In the manufacture of varnishes and other like solutions the use of gums that
have previously been subjected to the action of the vapour of volatile solvents at a
temperature so moderate as not to injure the gums, substantially as herein described.
2. The manufacture of varnishes and other solutions for coating surfaces and for
other uses from guin copals, gumiresins and other gums by (1st) reducing said gums to a
state of increased solubility by treating them with the vapours of volatile solvents
aided by heat so gentle as not to be injurious to the gums, and (2ndly) forming solu-
tions from such gums 30 increased in solubility by the addition thereto of solvent
liquids of the same or analogous nature as were used to provide the solvent vapours
either with or without the addition of other liquid bodies suitable for further attenua-
tion of the resulting solution of gums substantially as set forth.
.3. In the treatment of gum copal, gum resins and other gums for the manufacture
of varnishes and other solutions for coating surfaces and for other uses subjecting the
same to the vapours of solvents such as herein referred to in closed vessels on suitable
supports with only gentle beat (heat insufficient to injuriously affect the gums), either
alone or in combination with vapours of other solvent bodies.
4. In the manufacture of varnishes and other solutions thereof, the treatment of
comminuted or divided gum copals, gum resins and other gums whilst supporte: on
suitable extended surfaces in closed chambers with only gentle heat, by means of
vapours evolved from suitable solvent bodies until such matters are sufficiently
penetrated and rendered more readily tractable to solution and the subsequent solution
of the same by means of subsequent treatment of suitable solvents as set forth.
5. In the treatment of comminuted or divided gum copals, gum resins and other
guins for the manufacture of varnishes and other solutions for coating and for other
uses the use of apparatus constructed substantially as hereinabove set forth.
Dated the 17th day of Anril 1400
WM. BROOKES & SON,..
55 & 56, Chancery Lane, London,
Agents for the Applicant.