Note: Descriptions are shown in the official language in which they were submitted.
~a~'73~2
The present invention relates to an exothermic com-
position forwarmingbags for use in warming the humanbody by using
as a heat source a compound of a metal powder generating heat
in the presence of water and oxygen. The present invention
also provides a warming bag containing the composition.
A warmlng bag is known containing a composition
prepared by adding an aqueous solution of a metallic halide
salt, such as NaCl, KCl, CaC12, FeC13, FeC12, MgC12, or AlC13,
or a metallic sulfate salt, such as Na2SO4, K2SO4, Fe(SO~)3,
FeSO4 or MgSO4 to a mixture of active carbon with an exothermic
metal such as an iron powder in a single bag so as to generate
heat in the introduction of air. However, when such exothermic
composition is lefi insulated all from air, hydrogen will be
gradually and continuously generated, will accumulate in the
bag/ will become high in concentration with the lapse of days,
will occasionally inflate the bag and there will be the danger
of ignition and explosion. The merchandised conventional warm-
ing bag is usually of a structure in which an exothermic metal
and a reaction assistant are separately sectioned from each
other in a vented inner bag which is enclosed with a non-vented
outer bag. When the bag is to be used, the outer bag must be
broken and the inner bag taken out, shaken and kneaded to mix the
contents which is troublesome. When the mixing is insufficient,
the time of heat generation will be reduced and the iron powder
will become block-like and will give a different ~eeling.
Further, the charying structure is so complicated that the pro-
duction rate can not be increased and the cost is high.
The present invention provides an exothermic composition
wherein an exothermic metal and an exothermic assistant are not
sectioned from each other but are mixed together, such exothermic
charactexs as a warm feeling and heat generation durability are
not impaired and there is no danger of ignition and explosion.
~2~392:
Thus the disadvantages of the conventional warming bag are
avoided.
According to the present invention there is provided
an exothermic composition ~or warming bags which is prepared by
mixing 20 to 25 parts by weight of an iron powder with a mixed
~ibrous and carbonaceous powder impregnated with a solution
prepared by dissolving a proper amount of a neutral salt in
8 to 15 parts by weight of an aqueous solution of a 0.05 to 1-
normal alkali or alkaline weak acid salt and leaving the mixture
as sealed, to mature. The exothermic composition according to
the present invention has the following effects: (I) It is
possible to produce a warming bag wherein even though the
exothermic metal and reaction assistant are mixed together in
a bag, the generation of hydrogen is inhibited and, even when
it is stored for a long time, there is no danger of ignition and
explosion and the exothermic performance of the composition are
not impaired. (II) The exothermic metal (iron powder) and
reaction assistant (the aqueous salt solution, carbonaceous
and fibrous materials, water and the like) are uniformly mixed,
the generation of hydrogen is prevented by adding a proper
amount of the alkali or alkaline weak acid salt to mature.
Therefore the quality of the product does not fluctuate and a
highly efficient heat generation durability and an excellent
warm feeling are exhibited. (III) As the exothermic composition
is homogenously mixed, such charging structure of the exothermic
composition as (a) means of containing it in an inner bag having
a ventilating part in a ~ortion and packing and sealing the inner
bag with a non-ventilated outer bag or (b) means of containing
it in a non-ventilated bag having a ventilating part in a
portion on which a non-ventilated label is pasted is simple.
An ordinary automatically made bag can be easily charged at a
high speed and the production cost can be substantially reduced
~ 739
.
as compared with the sectioned charged conventional warming bag.
(IV) In the case of ~III)(a), the inner bag is taken out of the
outer bag and can be used per se fitted to the human body. In
the case of (III) (b), the label is peeled off the inner bag
which can be used per se fitted to the human body.
Therefore, the warming bag accordiny to the present
invention is much simpler in the using operation than the sec-
tioned charged conventional warming bag.
The present invention will be further illustrated by
way of the accompanying drawings in which:
Fig. 1 is a partly sectioned perspective view of a
warming bag according to one embodiment of the present invention.
Fig. 2 is a partly sectioned perspective view of an
inner bag.
The experimental results comparing respectively the
exothermic performances and the amounts of hydrogen generated
as insulated from air (e.g. during the storage) of the convention-
al exothermic composition and the exothermic composition of the
present invention are as follows.
(1) Method of measuring the amount of generated hydrogen.
A container having an inlet pipe and outlet pipe was
charged in the centra-l portion with a fixed amount of each
sample so that nitrogen gas might contact and carry it, was
arranged in a thermostatic tank and was kept at a predetermined
temperature. Nitrogen in a bottle was humidified to be of a
selected humidity in a selected flow volume and was piped into
the inlet pipe. The nitroyen gas having contacted the sample
was piped through a gas-chromatograph and flow meter connected
to the outlet pipe, The amount of hydrogen generated per hour
delivered by the sample was calculated from the analysis value
of the hydrogen concentration in the outlet nitrogen gas and the
gas flow measured value.
(2) Method of measuring the heat ~eneration (warm feeling test).
A rectangular flat inner bag of outer peripheral
effective dimensions of 8 cm. wide x 12 cm. long was made by
thermally fusing a film made by laminating a nonwoven fabric
(of 40 g./m2.) and a polyethylene film (of 70 microns) on the
outer periphery,except one end hacl 230 pinholes of a diameter
of 0.5 mm. through one surface 50 as to be ventilated, was
charged with a fixed amount of each sample, it was thermally
fused on the end, was then put into an outer bag of a non-
ventilated film and was seAled.
In the testing method, the inner bag was taken out of
the outer bag, was once gripped down to introduce air into the
bag and was closely fitted to a human body through underwear.
The time when the inner bag was taken out of the outer bag was
made a starting point. The time until a pleasant temperature
was reached was made the temperature rising time. Then the time
until the temperature lowered to 40C was made ~ heat yeneration
lasting time. ~ach sample was tested under the same conditions.
(3) Conditions of preparing the sample.
A mixture of 2~ g. of an iron powder, 4.5 g. of an
active carbon powder as a carbonaceous material and 6 g. of a
wood powder as a fibrous material was common to the respective
samples. The above described mixture of the active carbon
and wood powder was impregnated with an aqueous solution of a
salt shown in the following Table or a solution prepared by
dissolving hydrochloric acid in a normal solution of an alkali
or alkaline weak acid salt and was mixed the iron powder to
prepare a sample. Each sample was left to mature as sealed
for 15 hours and was tested. That is to say, the known conven-
tional exothermic composition was made a reference and had
(NaOH~ and Ba(OH)2 as alkalis and Na2CO3, NaHCO3 and Na3PO4 as
alkaline weak acid salts added thereto.
~;~392
Known exother~ic composition samples ~a, b), samples
of the present invention to which an alkali or an alkaline weak
acid salt was added ~c to j) and samples containing no salt and
having had an alkali or an alkaline weak acid salt added (k and
1) for information were prepared and were tested under the same
conditions.
Sample sign Added amount of Added amount of the alkali
the salttin g.) or alkaline weak acid salt
_ (in ml.)
a FeC13 1.5 Pure water 10
b NaCl 1.5 " 10
c ll ll lN NaOH
d ll ll 0.lN NaOH
e ll ll 0.05N NaOH
f " ,. 0.lN Ba(OH)2
g ll ll lN Na2CO3
h ll ll 0.lN Na2CO3
i 11 tl O . lN NaHCO3
j 11 ,l O . lN Na3PO4
k None 0 lN NaOH
1 None 0 lN NaHCO3
(4) Test results.
~I) Amount of generated hydrogen.
~s the amount of generated hydrogen of each exothermic
composition sho~ed a stabilized value in about 50 hours after
nitrogen gas began to be passed, the measured value of each
sample in 50 hours from the beginning was shown. The temperature
of the composition was maintained at the room temperature (1~C)
and 40C. The humidity was maintained at the atmospheric
pressure saturation at the testing temperature.
7;~Z
Sample Sign A~ount of generated hydrogen (in ml./hr.)
At the room At 40C
. _ . _ temperature (18C)
a ' 1.2 3.1
b 0.15 0.3
c O 0.001>
d 0.014 0.025
e 0.035 0.06
f 0.04 0.038
g 0.005 0.024
h - 0.03 0.063
i 0.035 0.06
i 0.02 0.04
k 0 0
1 O , .
(II) Exothermic performances.
_
~ample sign Temperature Lasting time Warm feeling
rising time ~in hours)
: _ . _(in minutes.) . .
a 3 20 Pleasant (rather
high in tempera-
ture)
b 5 20 Pleasant
c 18 36 Rather low
d 3 27 Pleasant
e 5 26 Pleasant (rather
ture)
f 3 24 Pleasant
g 17 32 Rather low
h 3 28 Pleasant
i 4 25 Pleasant
~7392
-(II) Exothermlc pexformances. (continued~
i 3 24 Pleasant (rather¦
high in tempera-¦
k None 0 No heat genera- ¦
_ None No heat genera-
When an a~ueous solution of an alkali of 0.05 to lN
was added to mature the composition, the amount of generated
hydrogen of the exothermlc composition could be maintained less
than the amount of hydrogen permeated through the nonventilated
outer bag film and the danger could be eliminated.
When the nonventilated bag was charged with each of
the compositions (c to j) of the present invention and was left
at ambient temperature for one year, the bag was not seen to
in~late. The hydrogen concentration within the bag was shown
to be less than 0.1% and it was confirmed that there was no
danger. However, the hydrogen concentration within the bag
charged with each of the known compositions (a and b) was
shown to be 5 to 9%.
The a~ueous lN alkalisolution additivehad along duration
of heat generation but was slow in the temperature rising and
was rather low in the warm feeling. However, the O.lN alkali
or alkaline weak acid salt additive was fast in the temperature
rising, was favorable in the warm feeling and was shown to be
longer in the heat generation duration than the conventional
compositions. The alkali or alkaline weak acid salt concentra-
tion of about 0.1 to 0.5N showed favorable results in the warm
feeling and durability.
Even when the exothermic composition was sealed and
matured for 10 hours after being mixed, the generation of hydrogen
73~2
could be substantially pxevented. The sealed maturiny for
more than 15 hours was preferable. As shown in the control
samples (k and 1~, in case an aqueous solution of an alkali or
an alkaline weak acid salt was added to the exothermic composi-
tion from which the salt had been removed, no heat was generated
and the amount of the generated hydrogen was zero.
As described above, as compared with the conventional
composition, the exothermic composition of the present invention
is very low in the amount of generated hydrogen, provides no
danger and shows excellent exothermic performances. In the
production, the composition o~ the present invention can be
made at a bag charging rate twice as high as the conventional
article (charged as sectioned) and can be remarkably reduced
in the production cost.
Referring once more to the accompanying drawings, an
exothermic composition 1 prepared by mixing 25 g. of an iron
powder, 4.5 g. of active carbon, 6 g. of a wood powder and
1.5 g. of table salt, adding 10 c.c. of 0.1N NaOH to the mixture,
putting the mixtur~ in a sealed container and then leaving it
to mature, is contained in an inner bag 2. Th~ inner bag 2 is
made of the above mentioned sample, that is, a nonventilated
film 3 formed of a laminated film of a nonwoven fabric of
40 g./m and polyethylene of 70 microns, is made a flat rectangle
of effective outer peripheral dimensions of 8 cm. long x 12 cm.
wide and is thermally fused at 4 on the three sides. One side
has a ventilating hole group 5 of about 230 pinholes of diameter
of 0.5 mm. formed on the surface and has a nonventilated label 6
pasted with an acrylic resin paste on this ventilating hole
group 5.
An outer bag 7 which contains the inner bag 2 and in
which a nonventilated film 8 formed of a transparent KOPET
~a trademark) ~ilm made by laminating polypropylene of 15 microns
~Z73~;~
on the outside and polyethylene of 50 microns on the inside
and coated with vinylidene chlorlde is used, is in the form of
a rectangle of effective outer peripheral dimensions of 11 cm.
long x 16 cm wide and is thermally fused at 9 on the three
sides. The inner bag 2 charged with the above mentioned e~o-
thermic composition 1 is contained in this outer bag 7 and then
the outer bag 7 is thermally fused on the remaining one side to
form the warming bag 11. ~ notch 12 is made on the outer bag 7.
One side of the outer bag 7 is cut off through this notch 12
and the inner bag 2 is taken out to use the warming bag 11.
Examples
Six samples of the above mentioned exothermic composi-
tion were prepared. Three inner bags having no label and three
inner bags pasted with labels were charged with the respective
samples under the same conditions, were then thermally sealed
and were inserted into the respective outer bags and the outer
bags were thermally sealed to make a total of six sealed samples.
Long standing tests were started on April 1, 1977. In
order to confirm the heat generation duration in the use at the
time of the beginning, each of the bag without the label and
the bag with the label was used. Then each of the bag without
the label and the bag with the label was arranged by the side
of a sunny window. Each of the bag without the label and the
bag with the label was arranged within a shady room. How the
appearance ana the heat generation durability varied when they
were left fox about one year was observed and confirmed. The
results were as foll~ws;
~L~Z73~
Appearance TestS
Sample name S~mple without label Sample with label
. ..
Arranging place By the side ~ithin shady By the side Within shady
of window room of window room
..
April, 1977 Nothing wrong Nothing wrong Nothing wrong Nothing wrong
June, 1977 ll ~- ~-
August, 1977 Water drops
accumulated
within the
outer bag
and the in-
ner bag was
wet
October, 1977 The inner The outer ll
: bag was wet bag was
by 2/3 and cloudy on
a large a- the inside
mount of surface and
water was the inner
present bag was
within the partly wet
: the outer
bag
December, 1977 ll .. . 1~ .,
February, 1978 .. ll ll "
April, 1978 ll .- ~- ll
June, 1978 .
Practice Tests (Heat generation duration in the use)
.. .
Sample without label Sample with label
_____ _ _ ~ , ..... .. ___
April, 1977 27H 27H
June, 1978 By the side With shady By the side With shady
of window room of window room
. 12H 18H 24H 27H
__ . . __ __
When the sample without the label was arranged by the
side of the sunny window, with the rise of the temperature, the
water contentinthe exothermic composition evaporated severely,
when the temperature lowered at night, the inner bag was wet on
--10--
~Z~3~2
the surface ~ith water drops and, with the lapse of days, the
amount of water on the outside increased to stain the surface
of the bag, the commodity value was remarkably reduced and the
heat generation durability in the use remarkably deteriorated.
However, with the sample with the label, irrespective of the
shady room or the window side, the inner bag was not wet on
the surface with water drops, the heat generation durability
did not substantially vary as compared with that at the beginning
of the test and the sample was confirmed to be endurable to
a long perservation.
.~ ~
