U.S. patent number 3,889,804 [Application Number 05/341,277] was granted by the patent office on 1975-06-17 for disposable towel.
This patent grant is currently assigned to Gorham International, Inc.. Invention is credited to Leonard E. Ravich.
United States Patent |
3,889,804 |
Ravich |
June 17, 1975 |
Disposable towel
Abstract
This invention relates to a disposable wet towel characterized
by an ability to evolve heat immediately prior to use or in use
such that the temperature of the towel is increased by as much as
25.degree. or more above ambient when applied to the skin. The
evolution of heat is due to the admixture of a reducing agent and
an oxidizing agent reactive with said reducing agent which agents
are kept separated prior to use of the towel and mixed when the
towel is put into use. The agents and products resulting from the
reaction thereof are not irritating to the skin. The invention also
provides pouches for storing said towels prior to use which pouches
contain means for maintaining said oxidizing agent and reducing
agent isolated from each other.
Inventors: |
Ravich; Leonard E. (Boston,
MA) |
Assignee: |
Gorham International, Inc.
(Gorham, ME)
|
Family
ID: |
23336923 |
Appl.
No.: |
05/341,277 |
Filed: |
March 14, 1973 |
Current U.S.
Class: |
206/221;
206/524.4; 206/568; 206/812; 206/222; 206/581; 401/132 |
Current CPC
Class: |
B65D
81/3261 (20130101); F24V 30/00 (20180501); Y10S
206/812 (20130101); A47K 2010/3293 (20130101) |
Current International
Class: |
F24J
1/00 (20060101); B65D 81/32 (20060101); A47K
10/24 (20060101); A47K 10/32 (20060101); B65d
081/32 () |
Field of
Search: |
;206/219,221,812,222,223,205,209,210,525 ;15/104.93 ;128/399 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Summer; Leonard
Attorney, Agent or Firm: Goldberg; Robert L.
Claims
I claim:
1. An article comprising an airtight pouch where said pouch is
divided into two chambers, each containing a towel, the towel in
one of said chambers being impregnated with a solution of oxidizing
agent and the towel in the other of said chambers being impregnated
with a solution of reducing agent, whereupon with rupture of said
chambers, the two towels are brought together causing mixing of
said oxidizing agent and reducing agent to cause an exothermic
reaction and a temperature rise in said towels above ambient
temperature.
2. The article of claim 1 where said towel is of paper.
3. The article of claim 1 where the concentration of said oxidizing
agent and reducing agent in solution is sufficient to provide a
temperature rise in said towels of at least 25.degree.F.
4. The article of claim 1 where said solution of oxidizing agent
contains a stabilizer.
5. The article of claim 4 where said oxidizing agent is selected
from the group of hydrogen peroxide and urea hydrogen peroxide.
6. The article of claim 4 where said oxidizing agent is a
peroxide.
7. The article of claim 6 where the reducing agent is selected from
the group of thiourea and a thiobarbituric acid.
8. The article of manufacture of claim 7 where said reducing agent
is thiourea.
Description
BACKGROUND OF THE INVENTION
This invention relates to wet disposable towels capable of evolving
heat upon use to effect a temperature rise.
Wet disposable towels are known in the art. Typically, they are of
paper and are stored in an airtight pouch such as an aluminum foil
pouch lined with a protective liner such as polyethylene. When
desired for use, the pouch is torn open and the wet towel removed.
Such towels are usually impregnated with an aqueous solution
containing various additives such as perfumes, astringents,
humectants and frequently menthol to give a cooling effect when
applied to the skin.
SUMMARY OF THE INVENTION
The subject invention provides a wet disposable towel that evolves
heat immediately prior to or during use such that it is above
ambient temperature when applied to the skin. The evolution of heat
is accomplished by bringing together a reducing agent and an
oxidizing agent such that an exothermic chemical reaction results.
The amount of heat evolved and the corresponding temperature rise
is in part determined by the relative concentrations of the
oxidizing agent and the reducing agent. The invention also provides
pouches for storing said towels prior to use which pouches contain
means for maintaining said oxidizing agent and reducing agent
separated from each other.
Accordingly, one object of the present invention is to provide a
self-heating, hot disposable towel for application to the skin.
Another object is to provide a towel impregnated with a two part of
aqueous solution, one part of which contains an oxidant and the
other part of which contains a reducing agent reactive therewith
such that upon mixing of the two parts, there is the evolution of
heat.
A further object of the invention is to provide a pouch containing
a towel, an aqueous solution of an oxidizing agent and an aqueous
solution of a reducing agent reactive with said oxidizing agent to
produce heat, said pouch characterized by means to maintain said
oxidizing agent and reducing agent separate from each other.
Other objects and advantages of the invention will be in part
apparent from the description which follows.
DESCRIPTION OF THE DRAWINGS
With reference to the drawings, FIG. 1 represents both a front view
and a cross-sectional view of a pouch containing a towel in
accordance with one embodiment of the invention;
FIG. 2 represents a cross-sectional view of a pouch containing a
towel in accordance with an alternative embodiment of the
invention;
FIG. 3 represents still another cross-sectional view of a pouch in
accordance with a further embodiment of the invention; and
FIG. 4 represents a dispenser for said pouches containing said
towels.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The material used for the towel and the pouch containing said towel
are in accordance with the materials of the prior art. Thus, paper
is the preferred towel material though cloth or a non-woven fabric
may be used and a foil such as aluminum foil lined with
polyethylene, for example, is the preferred pouch material. The
pouch must be airtight.
In order to obtain a heat rise immediately prior to or during use
of the towel of the invention, there are brought together two
solutions in contact with the towel which undergo an exothermic
chemical reaction. In accordance with the invention, these
materials are an oxidizing agent and a reducing agent, said agents
being reactive with each other.
The oxidizing agent may be any one of a wide variety of materials
depending upon the precise requirement of the particular
composition in which it is used. Among the oxidants that may be
used are hydrogen peroxide, urea hydrogen peroxide, sodium
peroxide, sodium perborate, sodium persulfate, ammonium persulfate,
potassium persulfate and mixtures of the foregoing.
The quantity of oxidizing agent and reducing agent contained in the
liquid composition impregnated into the hot towel will depend in
part upon how much heat is desired and in part upon the nature of
the by-products which may result from the reaction. It is generally
desirable that the amount of reducing agent be at least as great as
the amount required for stoichiometric reaction with all of the
oxidizing agent present in the liquid composition. It is generally
preferred that 5 to 10 mole percent excess of the reducing agent be
present in order to insure complete reaction of all of the
oxidizing agent. In some cases, however, the quantity of the
oxidizing agent initially present may be greater than the
stoichiometric quantity required for reaction with all of the
reducing agent because, due to the nature of the reducing agent, it
may be desirable to isnure complete utilization thereof. In these
cases, up to 10 mole percent excess oxidant may be employed, said
oxidant being consumed preferably within 15 seconds when used with
a mixture of a reducing agent, catalyst for the reaction and other
materials. Both the oxidizing agent and reducing agent, as well as
the by-products formed from said reaction, should be harmless to
the skin.
The concentration of the oxidizing agent and reducing agent in the
total aqueous composition impregnated into the towel will depend
upon the amount of heat required to heat up the composition and
towel, and the rate at which the heat is dissipated. As little as
0.8 percent by weight of oxidant based upon the total weight of the
aqueous composition impregnating the towel will suffice when a
stoichiometrically equivalent quantity of reducing agent is used.
However, at least 1 percent is preferred and in general, the amount
is that amount necessary to heat the towel at least 25.degree.F.
above ambient temperature. As the proportion of the oxidizing agent
and reducing agent is increased, the rate of heat generation
approaches a maximum which varies depending upon the particular
materials used. Once the maximum rate of heating has been achieved,
further increase in the amount of oxidizing agent and reducing
agent has no substantial further effect on the heating rate
although the total quantity of heat evolved and hence the ultimate
temperature to which the hot towel is heated may still increase. In
the case of hydrogen peroxide or urea hydrogen peroxide, which
materials are the preferred oxidants, it is desirable to avoid
concentrations above 10 percent by weight.
It is desirable to have present in the part of the composition
containing oxidants, especially peroxides, conventional stabilizers
such as phenacetin, stannates and acid phosphates in order to
ensure stability of the oxidant solution during storage.
Because of the special characteristics required of compositions
applied to the skin, there are only a limited number of reducing
agents which may be employed. These characteristics include an
ability to react with the oxidizing agent to provide rapid and
adequate heat evolution, stability during normal storage, freedom
from objectionable color and odor, freedom from toxicity, from
physiological activity, from irritancy and sensitization. As noted
above, the amount of heat evolved preferably is sufficient to raise
the temperature of the entire composition impregnating the towel by
approximately 25.degree.F. above ambient temperature during a
period of 30 seconds, preferably 15 seconds or less after mixing.
Although there exists a substantial number of reductants which
exhibit the first three of the foregoing characteristics, most of
them lack to an appreciable extent one or more of the remaining
characteristics. The reductants which have been found to possess
all of the foregoing characteristics are thiourea and compounds
having the structure ##SPC1##
in which R.sub.1 may be hydrogen, lower alkyl, lower hydroxy alkyl,
lower alkoxy, or lower alkanoyl, and R.sub.2 may be any of the
foregoing except hydrogen and may in addition by phenyl. Among such
compounds are 1-phenyl-2-thiobarbituric acid,
1-phenyl-5-ethyl-2-thiobarbituric acid, 1-methyl-2-thiobarbituric
acid, 1-methyl-5-ethyl-2-thiobarbituric acid,
1-methyl-5-ethyl-2-thiobarituric acid,
1-ethyl-5-ethyl-2-thiobarbituric acid,
1-phenyl-5-methyl-2-thiobarbituric acid, and the like, all of which
are soluble in weakly alkaline aqueous media. The oxidants which
may be used with the foregoing reductants to produce the desired
results include hydrogen peroxide and urea hydrogen peroxide.
Preferably, the oxidant is present in an amount from 0.8 to about 2
percent by weight of the total aqueous composition. The proportions
of oxidant and reductant relative to each other are usually
adjusted as described above to insure complete reaction of the
oxidant with a small amount of excess reductant of the order of 5
to 10 percent of the total quantity of reductant. However in some
cases an excess of oxidant may be used, as pointed out above.
The preferred compositions also include a catalyst to accelerate
the reaction and hence to accelerate the rise in temperature of the
composition, although in some cases it is possible to achieve the
same result by employing an excess of reductant. While a variety of
catalysts which accelerate such oxidation-reduction reactions are
well known and may be used, best results are achieved with such
water soluble tungstates or molybdates as alkali metal (including
ammonium) tungstates or molybdates, e.g., sodium tungstate,
potassium tungstate, sodium molybdate, ammonium molybdate, etc.,
which not only accelerate the reaction, but also cause it to follow
a different course than that followed in the absence of catalyst,
at least in the case when thiourea is the reductant, so that there
are not produced the objectionable end products which are formed in
the absence of catalyst when thiourea is used.
The amount of catalyst required varies with the particular catalyst
employed and also with the specific oxidant and reductant present.
However, in the case of the preferred tungstate catalyst, the
quantity of catalyst for best results is approximately 75 .times.
10.sup..sup.-3 gram atoms of tungsten per mole of reductant, while
in the case of molybdates approximately 17.5 .times. 10.sup..sup.-3
gram atoms of molybdenum per mole of the reductant is best. As
little as half as much of the catalyst may be used successfully.
Excess catalyst may be used though the additional quantity has very
little effect. Inasmuch as the catalyst promotes decomposition of
the oxidant, it should be kept separated therefrom until
immediately before mixing of the two parts of the composition.
Therefore, the catalyst is preferably included in that part of the
composition containing the reducing agent.
The pH of the composition may be in the range of from 5 to 10. For
optimum results the pH should be in the range of from 7.5 to 8. In
order to maintain the composition within the desired pH range, it
may be necessary to include a buffer in the composition.
While a wide variety of alkaline agents or buffers may be used to
control pH, such as sodium, potassium or ammonium hydroxide or
sodium, potassium, calcium or ammonium carbonate or bicarbonate,
best results and minimum irritation of the skin are obtained by
using a lower polyalkanolamine such as diethanolamine,
di-isopropanolamine, triethanolamine, or tri-isopropanolamine. It
has been found permissible to have an excess of one of the
preferred polyalkanolamine materials present over and above the
minimum required to maintain the desired pH, the excess preferably
amounting to up to five per cent by weight of the total aqueous
composition.
In addition to the ingredients noted above and the composition
impregnated into the towel, other ingredients normally used in the
manufacture of wet disposable towels such as astringents,
humectants, perfumes and the like may be present in the
composition.
As noted above, prior to use, the reducing agent and the oxidizing
agent are kept isolated from each other. This is accomplished by
use of any of the especially designed pouches for the disposable
towel illustrated in the drawings though the drawings should not be
considered limiting of the various embodiments possible. With
reference to FIG. 1 of the drawings, there is shown a folded paper
towel 10 impregnated with a solution of a suitable reducing agent
and contained in a waterproof and airtight pouch 11. A pod 12
contains an aqueous solution of a suitable oxidant along with
stabilizers for said oxidant. When ready for use, a thread 13 is
pulled to rupture pod 12 resulting in release of the oxidant and
the admixture of the same with the reducing agent impregnated in
the towel 10. An exothermic reaction is initiated which will raise
the temperature of the towel about 25.degree.F. above ambient.
After a few seconds, preferably about 10 seconds, the pouch can be
ripped open and the towel used.
In FIG. 2 of the drawings, there is represented a variation of the
pouch disclosed in FIG. 1. In this embodiment, foil pouch 20 lined
with polyethylene is divided into 2 sections 21 and 22 by divider
23. Section 21 contains a folded paper towel, a towel of a
non-woven fabric or a cloth towel 24 impregnated with a solution of
a suitable reducing agent along with perfumes, humectants,
stabilizers and other materials as desired. Towel 25 in compartment
22 is impregnated with a suitable oxidant and stabilizer. The edges
26 and 27 of towel 24 and 25 are so arranged that when pouch 20 is
torn such as at location 28, the two towels can be pulled from the
pouch together to provide intimate contact with each other and
initiate the evolution of heat in accordance with the
invention.
FIG. 3 is a third alternative wherein there is provided pouch 30
containing a folded towel 31 impregnated with a solution of a
reducing agent and any other desired additive. A pod 32 contains an
oxidizing agent in a gel form. When the pouch is torn at location
33, the towel 31 is passed through the oxidizing gel to initiate
the exothermic reaction or, alternatively, the pod is ruptured and
the oxidizing gel squeezed onto the towel as described with
reference to a dispenser pack shown in FIG. 4 below.
In FIG. 4 of the drawing, there is represented a dispenser pack for
both storing pouches containing the paper towel and for removing
the pouches when desired to use the same. The dispenser pack
comprises a rectangular box 40 having stored therein pouches 41
stacked one upon the other. The dispenser pack is provided with a
slot 42 near the bottom thereof which slot is sized to accommodate
the removal of the pouch 41. The slot 42 has projections 43
extending downward and into the slot such that it constricts the
opening. In this way, as the pouch 41 is removed from slot 42, the
projections 43 make indentations on the pouch which will act to
rupture a pod (such as the pod of FIG. 3) containing an oxidizing
gel and spread the same over the towel so that the two components
mix together initiating the exothermic reaction. These projections
43 can be provided by putting a metal strip across the top of the
slit, metal being used because of its strength. A serrated edge
(not shown) or any other means to rupture the pod within the pouch
can be substituted for projections 43.
The following specific examples are intended to illustrate more
fully the invention, but are not intended to limit its scope.
EXAMPLE 1
A first solution of reducing agent is prepared having the following
composition in parts by weight:
Ingredients Parts ______________________________________ Thiourea
1.52 Sodium tungstate dihydrate 0.52 Triethanolamine 1.00 Perfume
0.39 Water 96.57 ______________________________________
The second part consists of an aqueous solution containing 8.2
percent hydrogen peroxide by weight together with the usual amounts
of sodium stannate and phenacetin as stabilizers.
A paper towel was impregnated with the first solution of the
reducing agent. The paper towel was folded and inserted into an
aluminum foil pouch lined with polyethylene. A pod within the pouch
was filled with the second solution of the oxidizing agent. The
ratio of the squeous composition comprising the reducing agent to
the composition comprising the oxidizing agent was 3 to 1. The
pouch was sealed. Thereafter, the pod in the aluminum foil packet
was ruptured by squeezing and opened. The paper towel immediately
began to heat and the temperature of the towel was raised to about
100.degree.F.
EXAMPLE 2
A reducing agent composition was prepared having ingredients as
follows:
Ingredients Parts ______________________________________
1-phenyl-5-ethyl-2-thiobarbituric acid 5.00 Ammonium molybdate
tetrahydrate 0.06 Triethanolamine 1.00 Perfume 0.39 Distilled Water
93.55 ______________________________________
The oxidizing solution was the same as in Example 1. The procedure
of Example 1 was repeated and the rise in temperature of the towel
was to about 105.degree.F.
Similar results are obtained using as the reducing agent a molar
equivalent amount of 1-methyl-2-thiobarbituric acid in place of
1-phenyl-5-ethyl-2-thiobarbituric acid.
EXAMPLE 3
A reducing composition is made having the following
formulation:
Ingredients Parts ______________________________________
Triethanolamine 1.0 1-phenyl-2-thiobarbituric acid 4.8 Sodium
tungstate dihydrate 0.5 Water 93.7
______________________________________
The second part consisted of an aqueous solution containing 7.9
percent hydrogen peroxide by weight together with the usual amount
of sodium stannate and phenacetin.
Following the procedure of Example 1, upon mixing of the two parts
in proportion of 3 parts by weight of the reducing solution to 1
part by weight of the oxidizing solution at room temperature, the
towel underwent a temperature rise of about 130.degree.F.
* * * * *