Hygroscopic Paint or Coating Material for Keeping Packing Cases Dry.
Year: 1893

page_text: Date of Application, 13th Apr., 1893
Complete Specification Left, 12th Oct., 1893-Accepted, 3rd Feb., 1894
PROVISIONAL SPECIFICATION.
[Communicated from abroad by WESTFÄLISCH-ANHALTISCHEN SPRengstoff
ACTIEN GESELLSCHAFT, of Coswig Anhalt, Germany, Manufacturers.]
Hygroscopic Paint or Coating Material for Keeping Packing
Cases Dry.
I, CHARLES DENTON ABEL, of No. 28 Southampton Buildings, Chancery Lane
in the County of London, Consulting Engineer and Chartered Patent Agent, do
hereby declare the nature of this invention to be as follows:-
In packing for transport, goods, such as articles of food, drugs, gunpowder, and
the like that are injuriously affected by damp, it has heretofore been endeavoured
to prevent any such injurious action by enclosing the goods in airtight receptacles;
such airtight receptacles could only be made of metal with soldered joints.
Such airtight packing is more particularly necessary for transport on the high
seas, where the cases are kept for a long time in contact with a moist atmosphere
charged with compounds having a strong chemical action, such as magnesium
chloride &c.
My foreign correspondents have found that for preventing the injurious action of
moisture upon the goods to be transported, it is not at all necessary to employ
hermetically closed receptacles, but that receptacles more or less pervious to water
and air, made of pasteboard, wood, or the like can be employed if care be taken to
insure that the moisture which penetrates into the receptacles together with the
air, is at once absorbed, and that nothing can come in contact with the goods
themselves. In order to effect this, there is employed according to the present
invention a paint or coating of a hygroscopic nature which is applied to the inner
surface of the receptacles or packing cases, and which is composed of three
substances, namely, firstly a hygroscopic substance, such as, for example, a
hygroscopic salt (chloride of calcium chloride of magnesium, acid sulphate of
soda &c.), secondly, an absorbent material, such as infusorial earth, which retains
the hygroscopic substance and prevents it from running away in consequence of
having absorbed a large amount of moisture, and thirdly, a binding material, such
as, for example, waterglass, marine glue or gum arabic. By the mixing together
of these three substances, a material is obtained which is very flexible, adheres
firmly to the sides of the receptacle, and which, even after absorbing a com-
paratively large amount of moisture will not run away. For, even if for example
the calcium chloride, which is best employed entirely free from water, is gradually
transformed into a salt having six equivalents of water, and would eventually
become perfectly liquid, it will nevertheless be retained by the absorbent material,
and as the latter is made to adhere firmly to the sides of the receptacle by the added
binding material, the hygroscopic salt will also be maintained uniformly spread on
such surfaces notwithstanding its greater or less degree of liquefaction and is
prevented from running down onto the bottom, maintaining its hygroscopic action
and keeping the goods free from moisture. It is also to be observed that the sides
of the casing, although coated with the said compound nevertheless remain perfectly
dry, as the hygroscopic coating naturally acts not only inwardly but also in the
outward direction.
In employing this material, either all inner sides of the receptacle can be coated
therewith, or only the inner surface of the cover, or a separate slab or plate, such
as a sheet of cardboard coated on one or both sides with the said hygroscopic
compound can be introduced into the receptacle.

page_text: If the compound is applied to the surfaces of the receptacle it may be covered
in with a porous covering such for instance as paper, or woven fabric for the sake
of appearance, or for preventing direct contact with the goods. The coating is by
this means bedded in the material of the receptacle, and when this is itself made of
paper, the hygroscopic compound can be imbedded in its sides at the time of making
the receptacle by either introducing it alone or mixed with paper material, between
two layers of paper or paste board.
In addition to the above named hygroscopic substances namely calcium chloride,
magnesium chloride, acid sulphate of soda, any other suitable solid or liquid
substances having the same effect may be used. In place of infusorial earth may
also be used pumice, brick earth, gypsum, fine sand, glass powder &c., and in
place of the binding materials mentioned may be used caoutchouc or gutta percha
solution, or the like.
1
101 1
*11000
ABEL & IMRAY,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Hygroscopic Paint or Coating Material for Keeping Packing
Cases Dry.
1, CHARLES DENTON ABEL, of No. 28 Southampton Buildings, Chancery Lane,
in the County of London, Consulting Engineer and Chartered Patent Agent, 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 :-
In packing, for transport, goods, such as articles of food, drugs, gunpowder, and
the like that are injuriously affected by damp, it has heretofore been endeavoured
to prevent any such injurious action by enclosing the goods in airtight receptacles.
Such airtight receptacles could only be made of metal with soldered joints.
Such air tight packing is more particularly necessary for transport on the high
seas, where the cases are kept for a long time in contact with a moist atmosphere
charged with compounds having a strong chemical action such as magnesium
chloride &c.
My foreign correspondents have found that for preventing the injurious action of
moisture upon the goods to be transported, it is not at all necessary to employ
hermetically closed receptacles, but that receptacles more or less pervious to water
and air made of paste board, wood or the like can be employed, if care be taken
to insure that the moisture which penetrates into the receptacles together with the
air is at once absorbed, and that nothing can come in contact with the goods
themselves. In order to effect this there is employed according to the present
invention a paint or coating of a hygroscopic nature which is applied to the inner
surface of the receptacles or packing cases, and which is composed of three
substances, namely, firstly a hygroscopic substance, such as, for example, a hygro-
scopic salt, (chloride of calcium chloride of magnesium, acid sulphate of soda &c.),
secondly an absorbent material, such as infusorial earth, which retains the hygro
scopic substance and prevents it from running away in consequence of having
absorbed a large amount of moisture, and thirdly, a binding material such as, for
example, waterglass, marine glue or gum arabic. By the mixing together of these
three substances, a material is obtained which is very flexible, adheres firmly to
the sides of the receptacle, and which, even after absorbing a comparatively large
amount of moisture will not run away. For, even if for example, the calcium
chloride, which is best employed entirely free from water, is gradually transformed
into a salt having six equivalents of water, and would eventually become perfectly
liquid, it will nevertheless be retained by the absorbent material, and as the latter

page_text: is made to adhere firmly to the sides of the receptacles by the added binding
material, the hygroscopic salt will also be maintained uniformly spread on such
surfaces notwithstanding its greater or less degree of liquefaction and is prevented
from running down on to the bottom, maintaining its hygroscopic action and
keeping the goods free from moisture.
It is also to be observed that the sides of the casing, although coated with the
said compound nevertheless remain perfectly dry, as the hygroscopic coating
naturally acts not only inwardly but also in the outward direction.
In employing this material, either all inner sides of the receptacle can be coated
therewith, or only the inner surface of the cover, or a separate slab or plate, such
as a sheet of cardboard coated on one or both sides with the said hygroscopic
compound, can be introduced into the receptacle.
If the compound is applied to the surfaces of the receptacle it may be covered
in with a porous covering such for instance as paper or woven fabric for the
sake of appearance or for preventing direct contact with the goods. The coating
is by this means bedded in the material of the receptacle, and when this is
itself made of paper the hygroscopic compound can be imbedded in its sides at
the time of making the receptacle by either introducing it alone or mixed with
paper material, between two layers of paper or paste-board.
In addition to the above named hygroscopic substances, namely calcium chloride,
magnesium chloride acid sulphate of soda, any other suitable solid or liquid
substances having the same effect may be used. In place of infusorial earth may
also be used pumice, brick, earth, gypsum, fine sand, glass powder &c., and in place
of the binding materials mentioned may be used caoutchouc or gutta percha solution
or the like.
The proportions in which the neutral substance and binding material are mixed
with the hygroscopic substance may be varied between wide limits, according to
the degree of porosity of the neutral substance employed, the more or less hygro-
scopic property of the second body, and the greater or less binding property of the
adhesive material.
Thus if for example a highly absorbent neutral powder such as infusorial earth
be employed I prefer to mix from 10 to 15 parts hereof with, say, 30 to 40 parts
of chloride of calcium, and 30 to 35 parts of glue. When a neutral powder of
less porosity and a body of weak hygroscopic power are employed, I employ these
in greater proportion to the glue, such as 25 parts of chloride of potassium, and
45 parts of powdered silica stone and 30 parts of glue.
Again, if in place of a strong binding material such as glue be used, as for
example starch, a considerably greater proportion hereof must be employed in
order to produce the necessary adhesion of the compound to surfaces of the
receptacles, thus for example 30 parts of pulverised brick, and 30 parts of chloride
of magnesium are mixed with 70 parts of starch.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim is:-
A hygroscopic paint or coating material for keeping packing cases dry, com-
posed of a mixture of a hygroscopic substance, such as calcium chloride, for
absorbing the moisture in the packing case, with a neutral powder, such as
pulverised clay, pumice stone, or the like, serving to bind the hygroscopic
substance, and a cementitious substance such as glue, waterglass, caoutchouc
solution, which secures the hygroscopic mixture on the inner surface of the
packing case or on any other suitable surface or object therein.
1
ABEL & IMRAY,
Agents for the Applicant.