U.S. patent application number 11/632227 was filed with the patent office on 2009-01-08 for wettable heat generating composition compressed body, heat generating body, and process for producing wettable heat generating composition compressed body.
This patent application is currently assigned to MYCOAL PRODUCTS CORPORATION. Invention is credited to Toshihiro Dodo.
Application Number | 20090007899 11/632227 |
Document ID | / |
Family ID | 35783985 |
Filed Date | 2009-01-08 |
United States Patent
Application |
20090007899 |
Kind Code |
A1 |
Dodo; Toshihiro |
January 8, 2009 |
Wettable Heat Generating Composition Compressed Body, Heat
Generating Body, and Process for Producing Wettable Heat Generating
Composition Compressed Body
Abstract
An object of the invention is to provide a wettable heat
generating composition compressed body which has various shapes and
various sizes, is wettable and is capable of generating heat upon
contact with air. Another object of the invention is to provide a
heat generating body having a structure in which the foregoing
wettable heat generating composition compressed body is interposed
between a substrate and a covering material and at least the
periphery of the wettable heat generating composition compressed
body is sealed and having an exothermic part having an
air-permeable part. A wettable heat generating composition
compressed body resulting from compression of a moldable heat
generating composition capable of causing an exothermic reaction
upon contact with air, which is characterized in that the heat
generating composition is one prepared by subjecting a reaction
mixture containing, as essential components, an iron powder, a
carbon component, a reaction accelerator, a crosslinking type water
absorptive polymer and water but not containing a flocculant aid, a
flocculant, an agglomeration aid, a dry binder, a dry binding
agent, a dry binding material, a sticky raw material, a thickener,
an excipient, an alcohol, a crosslinking agent and a plasticizer
and having a water content of from 1 to 20% by weight and a water
mobility value of less than 0.01 to a contact treatment with an
oxidizing gas under circumstances at 0.degree. C. or higher,
regulating a temperature rise of the reaction mixture at 1.degree.
C. or higher within 10 minutes, and adjusting the water content so
as to contain surplus water having a water mobility value of from
0.01 to 20 and has moldability due to the surplus water as a
connecting substance, in which the water in the heat generating
composition does not function as a barrier layer; that the moldable
heat generating composition is molded by in-mold compression by
filling in a mold cavity of a mold cavity-provided die to a depth
substantially the same as the depth of the mold cavity and
compressing to a thickness of from 50 to 99.5% against the depth of
the mold cavity; and that the compressed body is non-flexible and
has shape holding properties.
Inventors: |
Dodo; Toshihiro; (Kanagawa,
JP) |
Correspondence
Address: |
KRATZ, QUINTOS & HANSON, LLP
1420 K Street, N.W., Suite 400
WASHINGTON
DC
20005
US
|
Assignee: |
MYCOAL PRODUCTS CORPORATION
Tochigi-shi
JP
|
Family ID: |
35783985 |
Appl. No.: |
11/632227 |
Filed: |
July 14, 2005 |
PCT Filed: |
July 14, 2005 |
PCT NO: |
PCT/JP05/13002 |
371 Date: |
March 6, 2008 |
Current U.S.
Class: |
126/263.02 |
Current CPC
Class: |
C09K 5/18 20130101; A61F
7/034 20130101; F24V 30/00 20180501 |
Class at
Publication: |
126/263.02 |
International
Class: |
F24J 1/00 20060101
F24J001/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 14, 2004 |
JP |
2004-207830 |
Claims
1. A wettable heat generating composition compressed body resulting
from compression of a moldable heat generating composition capable
of causing an exothermic reaction upon contact with air,
characterized in that: 1) the heat generating composition is one
prepared by subjecting a reaction mixture containing, as essential
components, an iron powder, a carbon component, a reaction
accelerator, a crosslinking type water absorptive polymer and water
but not containing a flocculant aid, a flocculant, an agglomeration
aid, a dry binder, a dry binding agent, a dry binding material, a
sticky raw material, a thickener, an excipient, an alcohol, a
crosslinking agent and a plasticizer and having a water content of
from 1 to 20% by weight and a water mobility value of less than
0.01 to a contact treatment with an oxidizing gas under
circumstances at 0.degree. C. or higher, regulating a temperature
rise of the reaction mixture at 1.degree. C. or higher within 10
minutes, and adjusting the water content so as to contain surplus
water having a water mobility value of from 0.01 to 20 and has
moldability due to the surplus water as a connecting substance, in
which the water in the heat generating composition does not
function as a barrier layer; that 2) the moldable heat generating
composition is molded by in-mold compression by filling in a mold
cavity of a mold cavity-provided die to a depth substantially the
same as the depth of the mold cavity and compressing to a thickness
of from 50 to 99.5% against the depth of the mold cavity; and that
3) the compressed body is non-flexible and has shape holding
properties.
2. The wettable heat generating composition compressed body
according to claim 1, characterized in that the heat generating
composition contains at least one member selected from additional
components consisting of a water retaining agent, a pH adjusting
agent, a hydrogen formatio inhibitor, an aggregate, a fibrous
material, a functional substance, a surfactant, an organosilicon
compound, a pyroelectric substance, a moisturizer, a fertilizer
component, a hydrophobic polymer compound, a heat generating aid, a
metal other than iron, a metal oxide other than iron oxide, an
acidic substance, and a mixture thereof.
3. The wettable heat generating composition compressed body as
according to claim 1, characterized in that the iron powder
comprising particles, a surface of each of which is at least
partially covered with an iron oxide film; that the iron oxide film
has a thickness of 3 nm or more; and that the active iron powder
particles having a region of an oxygen-free iron component in at
least one region selected from a central region of the iron powder
particles and a region beneath the iron oxide film is contained in
an amount of from 20 to 100% by weight.
4. A heat generating body, characterized by having an exothermic
part having a structure in which the wettable heat generating
composition compressed body according to claim 1 is interposed
between a substrate and a covering material and at least the
periphery of the wettable heat generating composition compressed
body is sealed.
5. The heat generating body according to claim 4, characterized in
that the exothermic part is an exothermic part in which a plural
number of sectional exothermic parts are provided at intervals;
that the sectional exothermic parts contain the wettable heat
generating composition compressed body; that the wettable heat
generating composition compressed body has a height of from 0.1 to
10 mm and a volume of from 0.01 to 30 cm.sup.3; and that a ratio of
the capacity of the sectional exothermic parts to the volume of the
wettable heat generating composition compressed body is from 0.6 to
1.0.
6. The heat generating body according to claim 4, characterized in
that in the heat generating body provided with two or more of the
sectional exothermic parts, the air-permeable surface is covered by
an air permeability adjusting material.
7. The heat generating body according to claim 4, characterized in
that an outer periphery of the sealed wettable heat generating
composition compressed body is collapsed by an outer pressure.
8. The heat generating body according to claim 4, characterized in
that at least a part of one of the exposed surfaces of the heat
generating body has a fixing measure.
9. A process for producing a wettable heat generating composition
compressed body resulting from compression of a moldable heat
generating composition capable of causing an exothermic reaction
upon contact with air, which is characterized by: 1) using, as a
heat generating composition, a moldable heat generating composition
prepared by subjecting a reaction mixture containing, as essential
components, an iron powder, a carbon component, a reaction
accelerator, a crosslinking type water absorptive polymer and water
but not containing a flocculant aid, a flocculant, an agglomeration
aid, a dry binder, a dry binding agent, a dry binding material, a
sticky raw material, a thickener, an excipient, an alcohol, a
crosslinking agent and a plasticizer and having a water content of
from 1 to 20% by weight and a water mobility value of less than
0.01 to a contact treatment with an oxidizing gas under
circumstances at 0.degree. C. or higher, regulating a temperature
rise of the reaction mixture at 1.degree. C. or higher within 10
minutes, and adjusting the water content so as to contain surplus
water having a water mobility value of from 0.01 to 20, and 2)
filling the moldable heat generating composition in a mold cavity
of a mold cavity-provided die to a depth substantially the same as
the depth of the mold cavity and compressing to a thickness of from
50 to 99.5% against the depth of the mold cavity.
Description
TECHNICAL FIELD
[0001] The present invention relates to a heat generating body
having a wettable compressed body selected from granules, pallets,
tablets, slugs, and mixtures thereof accommodated therein.
BACKGROUND ART
[0002] In recent years, various thermal materials are widely used
as a simple treatment tool for stiff shoulders, neuralgia, muscular
pain, and the like. Usually, such a thermal material is constituted
such that an exothermic agent capable of generating heat upon
contact with air is covered by a film having a prescribed air
permeability and that the heat generation is held for a prescribed
time by gradually reacting the exothermic agent with air, and this
is provided for use by sticking to the skin, a clothing, or the
like by an adhesive. As this exothermic agent, a mixed powder made
of a mixture of an iron powder, active carbon, NaCl and water is
usually used.
[0003] On the other hand, Patent Document 1 discloses a heat
generating body prepared by adding a binding agent to a powder and
applying a pressure thereto, thereby molding the mixture in a block
form.
[0004] Furthermore, Patent Document 2 discloses a heat generating
body in which a heating element is accommodated in an accommodating
section such as a pocket.
[0005] Furthermore, Patent Document 2 discloses a heat generating
body in which a heat generating composition made of a dry
compressed body heating element having a binding agent such as a
flocculant contained therein is accommodated therein.
[0006] Furthermore, Patent Document 3 discloses a heat generating
body made of a mixture of an exothermic agent capable of generating
heat upon contact with air and a water absorptive polymer and/or a
second polymer other than the water absorptive polymer, in which
the mixture is pressure integrated under a pressure of from 100 to
800,000 kg/cm.sup.2 together with any one of an alcohol, a
crosslinking agent or a plasticizer, and a heat generating body as
prepared by pressure integrating the mixture upon irradiation with
light or heating.
[0007] However, when a powder is used, since the powder moves
within a bag, it is difficult to form a thermal material having a
uniform thickness. Thus, there was involved a problem that a
uniform thermal effect is not obtained over the whole of the
sticking surface. Furthermore, since the thermal material
inevitably becomes thick as a whole, it was difficult to stick it
on the entire surface in a portion with a large curvature. In
particular, in the case where the thermal material is applied to a
face or the like, there was involved a problem that the thermal
material is so heavy that it deteriorates a feeling for use.
[0008] Furthermore, since the heat generating body in a block form
as described in Patent Document 1 does not have flexibility at all,
it is difficult to stick it to a curved part. Also, since this heat
generating body is hard and brittle, when an impact is applied
during the transportation or handling, there was involved a problem
that an edge is cracked or broken.
[0009] Furthermore, in the heat generating body as described in
Patent Document 2, a dry compressed body heating element is
accommodated in an accommodating section such as a pocket, and a
thermal cell is then exposed to oxygen, thereby causing heat
generation. Thus, under the pretext of activation of the heat
generating body, water or a salt solution must be injected into a
hole of the central part or a water storage part of a dry
compressed body heating element such as a tablet, or into a
granulate composition through an oxygen-permeable heat generating
body forming material sheet by an injection needle, resulting in a
problem in productivity. Moreover, since a binding agent such as a
flocculant is contained, there was involved a problem that an
exothermic performance drops.
[0010] Furthermore, in the pressure integrated heat generating body
as described in Patent Document 3, since the pressure integration
is achieved under a pressure of from 100 to 800,000 kg/cm.sup.2
together with any one of an alcohol, a crosslinking agent or a
plasticizer, the performance of the pressure integrated heat
generating body varies depending upon the production conditions
such as pressurization, heating and light irradiation conditions,
resulting in a problem in stabilization of product quality. Thus,
when this pressure integrated heat generating body is used as a
general heat generating body, there was involved a problem in
practical use in view of the exothermic duration, stability of
product quality, and so on.
[0011] [Patent Document 1] JP-A-59-189183
[0012] [Patent Document 2] JP-T-11-508314
[0013] [Patent Document 3] WO 00/13626
DISCLOSURE OF THE INVENTION
Problems that the Invention is to Solve
[0014] An object of the invention is to provide a wettable heat
generating composition compressed body which has various shapes and
various sizes, is wettable and is capable of generating heat upon
contact with air. Another object of the invention is to provide a
heat generating body having a structure in which the foregoing
wettable heat generating composition compressed body is interposed
between a substrate and a covering material and at least the
periphery of the wettable heat generating composition compressed
body is sealed and having an exothermic part having an
air-permeable part. A further object of the invention is to provide
a heat generating body which is flexible so that it is able to be
fitted even to any curved portion of a human body, is free from an
uncomfortable feeling at the time of fitting and is excellent in
usefulness by constituting the foregoing exothermic part by an
exothermic part composed of plural compartments. A still further
object of the invention is to provide a lightweight and
thin-layered heat generating body which is fitting to the whole of
the face.
Means for Solving the Problems
[0015] In order to solve the foregoing problems, the present
inventors made extensive and intensive investigations. As a result,
they have developed a wettable heat generating composition
compressed body having specific physical dimensions and filling
characteristics and being able to form an exothermic part or
including a specific iron oxidation chemical reaction to be put
into an exothermic part, a heat generating body utilizing the same,
and a process for producing for the foregoing wettable heat
generating composition compressed body or heat generating body.
[0016] As set forth in claim 1, a wettable heat generating
composition compressed body of the invention is a wettable heat
generating composition compressed body resulting from compression
of a moldable heat generating composition capable of causing an
exothermic reaction upon contact with air, which is characterized
in that:
[0017] 1) the heat generating composition is one prepared by
subjecting a reaction mixture containing, as essential components,
an iron powder, a carbon component, a reaction accelerator, a
crosslinking type water absorptive polymer and water but not
containing a flocculant aid, a flocculant, an agglomeration aid, a
dry binder, a dry binding agent, a dry binding material, a sticky
raw material, a thickener, an excipient, an alcohol, a crosslinking
agent and a plasticizer and having a water content of from 1 to 20%
by weight and a water mobility value of less than 0.01 to a contact
treatment with an oxidizing gas under circumstances at 0.degree. C.
or higher, regulating a temperature rise of the reaction mixture at
1.degree. C. or higher within 10 minutes, and adjusting the water
content so as to contain surplus water having a water mobility
value of from 0.01 to 20 and has moldability due to the surplus
water as a connecting substance, in which the water in the heat
generating composition does not function as a barrier layer;
that
[0018] 2) the moldable heat generating composition is molded by
in-mold compression by filling in a mold cavity of a mold
cavity-provided die to a depth substantially the same as the depth
of the mold cavity and compressing to a thickness of from 50 to
99.5% against the depth of the mold cavity; and that
[0019] 3) the compressed body is non-flexible and has shape holding
properties.
[0020] Also, a wettable heat generating composition compressed body
as set forth in claim 2 is characterized in that in the wettable
heat generating composition compressed body as set forth in claim
1, the heat generating composition contains at least one member
selected from additional components consisting of a water retaining
agent, a water absorptive polymer, a pH adjusting agent, an
aggregate, a fibrous material, a functional substance, a
surfactant, an organosilicon compound, a pyroelectric substance, a
moisturizer, a fertilizer component, a hydrophobic polymer
compound, a heat generating aid, a metal other than iron, a metal
oxide other than iron oxide, an acidic substance, and a mixture
thereof.
[0021] Also, a wettable heat generating composition compressed body
as set forth in claim 3 is characterized in that in wettable heat
generating composition compressed body as according to claim 1,
characterized in that the iron powder comprising particles, a
surface of each of which is at least partially covered with an iron
oxide film; that the iron oxide film has a thickness of 3 nm or
more; and that the active iron powder particles having a region of
an oxygen-free iron component in at least one region selected from
a central region of the iron powder particles and a region beneath
the iron oxide film is contained in an amount of from 20 to 100% by
weight.
[0022] As set forth in claim 4, a heat generating body of the
invention is characterized by having an exothermic part having a
structure in which the wettable heat generating composition
compressed body as set forth in claim 1 is interposed between a
substrate and a covering material and at least the periphery of the
wettable heat generating composition compressed body is sealed.
[0023] Also, a heat generating body as set forth in claim 5 is
characterized in that in the heat generating body as set forth in
claim 4, the exothermic part is an exothermic part in which a
plural number of sectional exothermic parts are provided at
intervals; that the sectional exothermic parts contain the wettable
heat generating composition compressed body; that the wettable heat
generating composition compressed body has a height of from 0.1 to
10 mm and a volume of from 0.01 to 30 cm.sup.3; and that a ratio of
the capacity of the sectional exothermic parts to the volume of the
wettable heat generating composition compressed body is from 0.6 to
1.0.
[0024] Also, a heat generating body as set forth in claim 6 is
characterized in that in the heat generating body as set forth in
claim 4, in the heat generating body provided with two or more of
the sectional exothermic parts, the air-permeable surface is
covered by an air permeability adjusting material.
[0025] Also, a heat generating body as set forth in claim 7 is
characterized in that in the heat generating body as set forth in
claim 4, an outer periphery of the sealed wettable heat generating
composition compressed body is collapsed by an outer pressure.
[0026] Also, a heat generating body as set forth in claim 8 is
characterized in that in the heat generating body as set forth in
claim 4, at least a part of one of the exposed surfaces of the heat
generating body has a fixing measure.
[0027] As set forth in claim 9, a process for producing a wettable
heat generating composition compressed body of the invention is a
process for producing a wettable heat generating composition
compressed body resulting from compression of a moldable heat
generating composition capable of causing an exothermic reaction
upon contact with air, which is characterized by:
[0028] 1) using, as a heat generating composition, a moldable heat
generating composition prepared by subjecting a reaction mixture
containing, as essential components, an iron powder, a carbon
component, a reaction accelerator, a crosslinking type water
absorptive polymer and water but not containing a flocculant aid, a
flocculant, an agglomeration aid, a dry binder, a dry binding
agent, a dry binding material, a sticky raw material, a thickener,
an excipient, an alcohol, a crosslinking agent and a plasticizer
and having a water content of from 1 to 20% by weight and a water
mobility value of less than 0.01 to a contact treatment with an
oxidizing gas under circumstances at 0.degree. C. or higher,
regulating a temperature rise of the reaction mixture at 1.degree.
C. or higher within 10 minutes, and adjusting the water content so
as to contain surplus water having a water mobility value of from
0.01 to 20, and
[0029] 2) filling the moldable heat generating composition in a
mold cavity of a mold cavity-provided die to a depth substantially
the same as the depth of the mold cavity and compressing to a
thickness of from 50 to 99.5% against the depth of the mold
cavity.
[0030] Also, in the wettable heat generating composition compressed
body, it is preferable that the iron powder contains from 20 to
100% by weight of an active iron powder in which at least a part of
the surface thereof is covered by a wustite film and an amount of
the wustite is from 2 to 50% by weight in terms of an X-ray peak
intensity ratio to iron.
[0031] Also, it is preferable that the substrate and the covering
material prior to sealing the periphery of the wettable heat
generating composition compressed body are substantially flat and
do not have a pocket, an accommodating section or an accommodating
zone.
[0032] Also, it is preferable that in the heat generating body, at
least one member of the substrate and the covering material prior
to sealing the periphery of the wettable heat generating
composition compressed body has a pocket and that the heat
generating composition compressed body is accommodated in the
pocket.
[0033] Also, it is preferable that in the heat generating body, the
seal part is formed by heat seal after temporary adhering by a
sticky layer and then forming a temporary seal and that an adhesive
component which constitutes the sticky layer and a component of a
heat seal material which constitutes a heat seal layer are
co-present in the heat seal part.
[0034] Also, it is preferable that in the heat generating body,
after the heat seal, at least a part of the accommodated wettable
heat generating composition compressed body is transferred to the
temporary adhering part which is not heat sealed, thereby
deadhering the temporary adhering part which is not heat
sealed.
[0035] Also, it is preferable that the heat generating body is
provided with a perforation between the sectional exothermic
parts.
[0036] Also, it is preferable that in the heat generating body, the
fixing measure is an adhesive layer, and the adhesive layer
contains at least one member selected from additional components
consisting of a water retaining agent, a water absorptive polymer,
a pH adjusting agent, a surfactant, an organosilicon compound, a
hydrophobic polymer compound, a pyroelectric substance, an
antioxidant, an aggregate, a fibrous material, a moisturizer, a
functional substance, and a mixture thereof.
ADVANTAGES OF THE INVENTION
[0037] In the wettable heat generating composition compressed body
of the invention, since a heat generating composition having a low
water content is subjected to a contact treatment with an oxidizing
gas, water in a necessary amount for obtaining practically useful
exothermic characteristics is then added, and the mixture is
compressed into a prescribed thickness, the wettable heat
generating composition compressed body of the invention is able to
take various shapes and various thicknesses, is of a thin type and
is excellent in exothermic rising properties.
[0038] Furthermore, by providing plural compressed bodies of a
small size made of a wettable heat generating composition
compressed body at intervals, it is possible to provide a heat
generating body which is able to be easily fitted to any curved
part of a human body and can effectively impart a thermal effect to
the whole of a sticking part.
[0039] Furthermore, exothermic characteristics including exothermic
rising properties are extremely excellent.
[0040] Furthermore, not only the manufacturing costs of a heat
generating body can be reduced, but also a lightweight and
thin-layered heat generating body which is free from a stiff
feeling, excellent in flexibility and extremely good in usefulness
can be provided.
[0041] In the light of the above, in particular, the heat
generating composition compressed body constituting a sectional
exothermic part can be easily incorporated into a throwaway body
wearing implement which can be adapted with various outer shapes of
the body. Accordingly, it is possible to warm the body
conveniently, comfortably and constantly.
BEST MODES FOR CARRYING OUT THE INVENTION
[0042] The wettable heat generating composition compressed body of
the invention is a wettable heat generating composition compressed
body resulting from compression of a moldable heat generating
composition capable of causing an exothermic reaction upon contact
with air, which is characterized in that:
[0043] 1) the heat generating composition is one prepared by
subjecting a reaction mixture containing, as essential components,
an iron powder, a carbon component, a reaction accelerator, a
crosslinking type water absorptive polymer and water but not
containing a flocculant aid, a flocculant, an agglomeration aid, a
dry binder, a dry binding agent, a dry binding material, a sticky
binder, a thickener, an excipient, an alcohol, a crosslinking agent
and a plasticizer and having a water content of from 1 to 20% by
weight and a water mobility value of less than 0.01 to a contact
treatment with an oxidizing gas under circumstances at 0.degree. C.
or higher, regulating a temperature rise of the reaction mixture at
1.degree. C. or higher within 10 minutes, and adjusting the water
content so as to contain surplus water having a water mobility
value of from 0.01 to 20 and has moldability due to the surplus
water as a connecting substance, in which the water in the heat
generating composition does not function as a barrier layer;
that
[0044] 2) the moldable heat generating composition is molded by
in-mold compression by filling in a mold cavity of a mold
cavity-provided die to a depth substantially the same as the depth
of the mold cavity and compressing to a thickness of from 50 to
99.5% against the depth of the mold cavity; and that
[0045] 3) the compressed body is non-flexible and has shape holding
properties.
[0046] By regulating the thickness of the heat generating
composition compressed body at a depth of the mold cavity or making
it on a basis of the depth, not only the degree of compression can
be easily adjusted, but also the shape holding properties can be
kept without scarifying exothermic characteristics such as
exothermic rising properties, exothermic durability, and exothermic
optimum temperature holding properties. The resistance to
compression of the moldable heat generating composition having
resistance to compression according to the invention is preferably
80% or more, more preferably 85% or more, and further preferably
90% or more. The resistance to compression may be 100% or more.
[0047] On the other hand, in the case of adding a flocculant aid, a
flocculant, an agglomeration aid, a dry binder, a dry binding
agent, a dry binding material, a sticky binder, a thickener, an
excipient, an alcohol, a crosslinking agent or a plasticizer or
determining the thickness of the compressed body by applying a
pressure on a basis of a pressure, the exothermic characteristics,
particularly exothermic rising properties are remarkably
deteriorated, and it takes a long period of time for arrival at a
desired temperature. Thus, it becomes difficult to produce a
practically useful heat generating body. Furthermore, while it is
possible to make a heat generating body of a short-time type, it is
difficult to prepare a compressed body capable of continuing the
heat generation of one hour or more at an optimum temperature. When
the heat generating body is compressed, though the shape holding
properties are improved, the exothermic rising properties are
deteriorated, the exothermic maximum temperature drops, and the
exothermic time becomes short. In particular, in a heat generating
body whose flexibility is enhanced by adding a crosslinking agent,
a plasticizer, etc., there was the case where for the purpose of
increasing the exothermic characteristics, the exothermic body is
inevitably used in an open state in which the air permeability is
not adjusted. It was difficult to embody a heat generating body in
which the air permeability is adjusted by using an air-permeable
film, etc. and which is able to be mildly warmed over a long period
of time.
[0048] Though the wettable heat generating composition compressed
body of the invention is not flexible, after compression, it is a
wetting compressed body capable of generating heat upon contact
with air without adding water or a metal salt-containing aqueous
solution to the compressed body, from which various heat generating
bodies including heat generating bodies having one exothermic part
and heat generating bodies having an exothermic part provided with
plural compartments at intervals, all of which are free from
pollution of the environment by a carbon component, etc., have
excellent exothermic characteristics and shape holding properties
and are thoroughly durable against processing to a heat generating
body. That is, it is possible to produce wettable heat generating
composition compresses bodies of various shapes including from a
curved shape to a linear shape and various sizes including from a
small size to a large size, from an extra-thin size to a thick
size, and from a narrow width to a wide width. Following this, it
is possible to produce exothermic parts and heat generating bodies
of various shapes and various sizes.
[0049] The sectional exothermic part or wettable heat generating
composition compressed body of the invention usually has a maximum
width of from 0.5 to 60 mm, preferably from 0.5 to 50 mm, more
preferably from 1 to 50 mm, further preferably from 3 to 50 mm,
still further preferably from 3 to 30 mm, even further preferably
from 5 to 20 mm, even still further preferably from 5 to 15 mm, and
even more still further preferably from 5 to 10 mm. Furthermore,
its maximum height is usually from 0.1 to 30 mm, preferably from
0.1 to 10 mm, more preferably from 0.3 to 10 mm, further preferably
from 1 to 10 mm, and still further preferably from 2 to 10 mm.
Furthermore, its longest length is usually from 5 to 300 mm,
preferably from 5 to 200 mm, more preferably from 5 to 100 mm,
further preferably from 20 to 150 mm, and still further preferably
from 30 to 100 mm.
[0050] Here, since the moldable heat generating composition having
a water mobility value of from 0.01 to 20 according to the
invention contains surplus water, when a pressure is applied,
particles are readily brought into contact with each other, whereby
the particles are fixed by means of a surface tension of water.
Furthermore, since the wettable heat generating composition
compressed body of the invention holds the thickness at the time of
molding, namely the thickness of from 45 to 99.5% of the depth of
the mold cavity, it is possible to sufficiently secure an
exothermic duration without losing the water necessary for the heat
generation at the time of compression and without need of
activation by online or offline addition of water or a salt
solution after the compression. Furthermore, although a rate of
compression is from 50 to 99.5% of the die thickness, it is
preferably from 50 to 95%, more preferably from 55 to 95%, further
preferably from 60 to 95%, and still further preferably from 70 to
90% of the die thickness.
[0051] Furthermore, the surplus water having a water mobility value
of from 0.01 to 20 which is necessary in the invention was
unpredictable. That is, there could be thought some possibility
that surplus water covers the powder surface and functions as a
barrier, whereby the exothermic reaction is remarkably deteriorated
and that a prescribed amount of water must be removed from the heat
generating composition as the case may be. However, since the
surplus water having a water mobility value of from 0.01 to 20 is
optimum in terms of surplus water, it imparted functions to the
heat generating composition such that coupling of carbon and iron
is promoted, a stiff compressed body is formed without excessively
diluting the heat generating composition, and an exothermic
reaction is caused immediately upon contact with air.
[0052] In the invention, by using surplus water having a water
mobility value of from 0.01 to 20 in the compression operation, it
is possible to reduce a carbon dust, to solve various problems in
the manufacture, to increase the manufacture line speed and
precision of charging weight, to improve fluidity of the heat
generating composition, to eliminate non-uniformity of the heat
generating composition within the completed exothermic part, to
improve the performance of the completed exothermic part and to
exclude necessity of special devices and circumstances, thereby
remarkably lowering required labors, health, danger in safety and
entire manufacture costs.
[0053] The exothermic part or heat generating body into which the
heat generating composition compressed body capable of generating
heat on a basis of a specific iron oxidation chemical reaction,
which is produced by the production process of the invention, is
incorporated has specific physical dimension and shape
characteristics and gives long-term durable exothermic properties
and improved temperature control properties. The sectional
exothermic part and exothermic part contain a wet type compressed
granulate exothermic substance or a wettable heat generating
composition compressed body. This wet type compressed granulate
exothermic substance or wettable heat generating composition
compressed body substantially fills an effective exothermic part
capacity in the sectional exothermic part and exothermic part and
reduces an excessive blank capacity which is possibly present,
thereby minimizing an ability of the exothermic substance to move
within the exothermic part. This is achieved without necessity for
applying a differential pressure to the exothermic part wall. Since
these exothermic parts have a flexible physical dimension, when
they are incorporated into a throwaway body wearing implement,
etc., they can be made adaptive with various outer shapes of the
body, whereby it becomes possible to warm the body conveniently,
comfortably and constantly.
[0054] Accordingly, the invention is aimed to provide a wet
compressed body and to provide a process for producing a wettable
heat generating composition compressed body which directly uses
compression of a powdered component including a carbonaceous
material and iron, is able to rapidly reach a maximum temperature,
continuously gives a controlled temperature, and is to be
incorporated into a sectional exothermic part or an exothermic
part. By incorporating such a wettable heat generating composition
compressed body into a throwaway body wearing implement which can
be adapted with various outer shapes, it becomes possible to warm
the body conveniently, comfortably and constantly.
[0055] The wettable heat generating composition compressed body of
the invention is one resulting from compression of a heat
generating composition containing, as essential components, an iron
powder, a carbon component, a reaction accelerator, a crosslinking
type water absorptive polymer and water and containing surplus
water having a water mobility value of from 0.01 to 20 to a
thickness at the time of molding, namely a thickness of from 50 to
99.5% of the depth of a mold cavity and is characterized by
generating heat upon contact with air. That is, in the wettable
heat generating composition compressed body of the invention, a
wettable heat generating composition compressed body of a fixed
shape or a sheet-like wettable heat generating composition
compressed body can be obtained by filling a heat generating
composition containing, as essential components, an iron powder, a
carbon component, a reaction accelerator, a crosslinking type water
absorptive polymer and water and containing surplus water having a
water mobility value of from 0.01 to 20 in a mold cavity of a die
and applying a prescribed pressure by using a compressing tool such
as a compression plate.
[0056] Examples of a process for producing a heat generating body
using the thus produced wettable heat generating composition
compressed body include a production process in which the wettable
heat generating composition compressed body is laminated on a
substantially flat substrate, a covering material is covered
thereon, and the periphery of the wettable heat generating
composition compressed body is then heat sealed; and a production
process in which the wettable heat generating composition
compressed body is filled in a pocket of a pocket-provided
packaging material, other packaging material is covered thereon,
and the periphery of the pocket is then heat sealed. In the
wettable heat generating composition compressed body, a shape
necessary for filling it in a pocket can be sufficiently kept.
Furthermore, in the heat generating body made of an exothermic part
having plural sectional exothermic parts (the term "plural" means
two or more) according to the invention, the space between the
sectional exothermic parts becomes flexible, and the flexibility as
a heat generating body is high. Thus, it is possible to make the
heat generating body of the invention fit to any curved part of a
human body. Furthermore, since exothermic characteristics per unit
weight are excellent, only a small amount of the exothermic agent
component is required for the purpose of realizing exothermic
characteristics comparable to those of conventional heat generating
bodies. Thus, it becomes possible to realize a lightweight and
thin-layered heat generating body so that the feeling for use is
remarkably improved.
[0057] As other production process of a heat generating body using
the wettable heat generating composition compressed body of the
invention, a heat generating body can also be produced by using a
magnetic force outputted from a magnet in the bottom of a die
singly or using a magnetic force jointly with reduced pressure,
holding a magnetic iron-containing wettable heat generating
composition compressed body in a prescribed flat place of a
substrate, placing a covering material on the substrate such that
the compressed body is placed between these two sheets, and
subsequently sealing the compressed body between the substrate and
the covering material. Furthermore, as another process, a heat
generating body can also be produced by using a magnetic force
outputted from a magnet in the bottom of a die singly or using a
magnetic force jointly with reduced pressure, holding a magnetic
iron-containing wettable heat generating composition compressed
body in a pocket as formed in advance in a substrate or a pocket as
formed by reduced pressure, placing a covering material on the
substrate such that the compressed body is placed between these two
sheets, and subsequently sealing the compressed body between the
substrate and the covering material.
[0058] The individual constitutions of the heat generating body of
the invention will be hereunder described in detail. The heat
generating composition which is used in the invention is a heat
generating composition containing, as essential components, an iron
powder, a carbon component, a reaction accelerator, a crosslinking
type water absorptive polymer and water and containing surplus
water having a water mobility value of from 0.01 to 20.
[0059] The heat generating composition is not limited so far as it
is a heat generating composition containing, as essential
components, an iron powder, a carbon component, a reaction
accelerator and water but not containing a flocculant aid, a
flocculent, an agglomeration aid, a dry binding material, a dry
binding agent, a dry binder, an adhesive binder, a thickener and an
excipient, containing surplus water having a water mobility value
of from 0.01 to 20 and having moldability due to the surplus water,
with the water in the heat generating composition not functioning
as a barrier layer, and capable of generating heat upon contact
with air.
[0060] Incidentally, in the invention, what water does not function
as a barrier layer and causes an exothermic reaction upon contact
with air means that water in a heat generating composition does not
function as a barrier layer which is an air intercepting layer and
immediately after the production of a heat generating composition,
comes into contact with air, thereby immediately causing an
exothermic reaction.
[0061] A particle size of the water-insoluble solid component which
constitutes the moldable heat generating composition of the
invention is not limited so far as the heat generating composition
has moldability. In the case where any one of the sizes (length,
width and height) of the heat generating composition molded body
resulting from molding of the heat generating composition is small,
when the particle size is made small, the moldability is
improved.
[0062] In addition, what the particle size of the solid component
which constitutes the moldable heat generating composition is made
small is preferable in view of molding. A maximum particle size of
the water-insoluble solid component exclusive of the reaction
accelerator and water in the components which constitutes the
moldable heat generating composition is preferably not more than
2.5 mm, more preferably not more than 930 .mu.m, further preferably
not more than 500 .mu.m, still further preferably not more than 300
.mu.m, even further preferably not more than 250 .mu.m, and even
still further preferably not more than 200 .mu.m. Moreover, 80% or
more of the particle size of the solid component is usually not
more than 500 .mu.m, preferably not more than 300 .mu.m, more
preferably not more than 250 .mu.m, further preferably not more
than 200 .mu.m, still further preferably not more than 150 .mu.m,
and even further preferably not more than 100 .mu.m.
[0063] In addition, if desired, at least one member selected from
additional components selected from a water retaining agent, a pH
adjusting agent, a hydrogen formation inhibitor, an aggregate, a
fibrous material, a functional substance, a surfactant, an
organosilicon compound, a pyroelectric substance, a moisturizer, a
fertilizer component, a hydrophobic polymer compound, a heat
generating aid, a metal other than iron, a metal oxide other than
iron oxide, an acidic substance, and a mixture thereof may be added
to the heat generating composition.
[0064] The components which constitute the heat generating
composition and the kinds of the components can be used singly or
in combination.
[0065] Furthermore, in the heat generating composition or the like
according to the invention, there is no particular limitation with
respect to the blending proportion thereof. However, it is
preferred to select the blending proportion such that the heat
generating composition contains from 1.0 to 50 parts by weight of a
carbon component, from 0.01 to 10 parts by weight of a water
retaining agent, from 0.01 to 20 parts by weight of a water
absorptive polymer, from 0.01 to 5 parts by weight of a pH
adjusting agent, from 0.01 to 12 parts by weight of a hydrogen
formation inhibitor, and from 1.0 to 50 parts by weight of a
reaction accelerator based on 100 parts by weight of an iron powder
and contains from 1.0 to 60 parts by weight of water so as to have
a water mobility value of from 0.01 to 20 as a heat generating
composition. In addition, the following substances may be added in
the following blending proportion based on the iron powder to the
heat generating composition. That is, examples include a metal
other than iron in an amount of from 1.0 to 50 parts by weight; a
metal oxide other than iron oxide in an amount of from 1.0 to 50
parts by weight; a surfactant in an amount of from 0.01 to 5 parts
by weight; an anti-foaming agent in an amount of from 0.01 to 5
parts by weight; a hydrophobic polymer compound, an aggregate, a
fibrous material, a pyroelectric substance, a far infrared ray
radiating substance, a minus ion emitting substance, and an
organosilicon compound each in an amount of from 0.01 to 10 parts
by weight; a moisturizer, an active substance, a fertilizer
component, and a heat generating aid each in an amount of from 0.01
to 10 parts by weight; and an acidic substance in an amount of from
0.01 to 1 part by weight. In the case of blending a magnetic body,
its blending proportion may be properly determined depending upon
the desire.
[0066] The reaction mixture and the heat generating mixture are the
same as in the moldable heat generating composition.
[0067] Furthermore, the following are preferable in view of
improving the exothermic rising properties of the heat generating
composition.
[0068] 1) A heat generating composition is formed by subjecting a
mixture of the essential components of the heat generating
composition, or to which are further added an acidic substances and
other necessary components, to a contact treatment (for example,
self heat generation) with an oxidizing gas or further subjecting
it to adjustment of water content or further adding and mixing
other components therein.
[0069] 2) An active iron powder having an oxygen-containing film
such as oxides on at least a part of the surface of an iron powder
is used as the iron powder.
[0070] a) An iron powder having an oxygen-containing film of iron
having a thickness, as determined by the Auger electron
spectroscopy, of 3 nm or more with respect to the surface of the
iron power is used.
[0071] b) An iron powder having a wustite content of from 2 to 50%
by weight in terms of an X-ray peak intensity ratio to iron is
used.
[0072] 3) A mixture of an active iron powder having an
oxygen-containing film such as oxides on at least a part of the
surface of an iron powder and an iron powder not having an
oxygen-containing film is used as the iron powder.
[0073] A usual iron powder, an iron alloy powder, an iron powder
having an oxygen-containing film on at least a part of the surface
of the iron powder, and an active iron powder made of an iron alloy
powder are preferable as the iron powder.
[0074] As the usual iron powder, a cast iron powder, an atomized
iron powder, an electrolyzed iron powder, a reduced iron powder,
and the like can be used. Examples of the iron alloy powder include
ones containing, as an alloy component, a metal including the
foregoing semi-conductors.
[0075] The "iron alloy" as referred to herein is an alloy of iron
containing 50% or more of iron. The alloy component is not
particularly limited so far as it is a metal component including
semiconductors other than iron and the iron component functions as
a component of the heat generating composition, and examples
thereof include silicon, zinc, aluminum, magnesium, manganese,
nickel, and copper.
[0076] As the metal oxide other than the iron oxide, any substance
may be employed so far as it does not hinder the oxidation of iron
by an oxidizing gas. Examples thereof include manganese dioxide and
cupric oxide.
[0077] Examples of the iron powder having an oxygen-containing film
on at least a part of the surface of iron include:
[0078] 1) an active iron powder prepared by subjecting a mixture of
the essential components of the heat generating composition, or to
which are further added an acidic substances and other necessary
components, to a contact treatment with an oxidizing gas, thereby
partially oxidizing the iron component and partially oxidizing at
least the surface of the iron component;
[0079] 2) an active iron powder having a wustite content of from 2
to 50% by weight; and
[0080] 3) a mixture of an active iron powder and an iron powder
other than the active iron powder.
[0081] Of these, a mixture containing 60% or more of an active iron
powder and less than 40% of an iron powder other than the active
iron powder is preferably enumerated.
[0082] In the case of storing the heat generating composition which
is treated with an oxidizing gas or the heat generating composition
containing an active iron powder, or a material utilizing the same
over a long period of time, it is preferred to combine a hydrogen
formation inhibitor therewith. This is because in this way, a heat
generating body having excellent exothermic characteristics, which
is inhibited in the formation of hydrogen, is free from swelling of
the outer bag at the time of storage, etc. and has satisfactory
exothermic rising properties, is obtained.
[0083] A thickness of the iron oxide film which covers the surface
of the iron powder is usually from 3 nm or more, preferably from 3
nm to 100 .mu.m, more preferably from 30 nm to 100 .mu.m, further
preferably from 30 nm to 50 .mu.m, still further preferably from 30
nm to 1 .mu.m, even further preferably from 30 nm to 500 nm, and
even still further preferably from 50 nm to 300 nm by using the
Auger electron spectroscopy. When the thickness of the
oxygen-containing film of iron is 3 nm or more, the thickness of
the oxygen-containing film of iron makes it possible to exhibit an
effect for promoting an oxygen reaction, and upon contact with an
oxidizing gas such as air, it is possible to immediately initiate
the oxidation reaction. When the thickness of the oxygen-containing
film of iron is 100 .mu.m or more, though there is some possibility
that the exothermic time becomes short, such can be employed
depending upon the utility.
[0084] An amount of FeO (wustite) which is contained in the iron
component containing the foregoing prescribed amount of wustite is
usually from 2 to 50% by weight, preferably from 2 to 40% by
weight, more preferably from 2 to 30% by weight, and further
preferably from 6 to 30% by weight in terms of an X-ray peak
intensity ratio to iron. Even when the amount of wustite exceeds
50% by weight, though the exothermic rising properties are
satisfactory, an exothermic duration becomes short. When the amount
of wustite is less than 2% by weight, the exothermic rising
properties become dull.
[0085] The thickness of the foregoing prescribed amount of an
oxygen-containing film or the oxygen-containing film of an iron
powder containing wustite and the wustite content are to be applied
to the heat generating composition or heat generating composition
molded body at the time of lamination.
[0086] In the iron powder or active iron powder in the oxidizing
gas-treated heat generating composition of the invention, at least
a part of the surface thereof is covered by an oxygen-containing
film of iron. The degree of covering on the surface of the
oxygen-containing film of iron is not limited so far as at least a
part of the surface thereof is covered, and the surface may be
entirely covered. In the case of the heat generating composition of
the invention, since an ion of the reaction accelerator such as a
chlorine ion is contained in the heat generating composition, there
is no corrosion effect of the oxide film due to a corrosion effect
by the ion of the reaction accelerator such as a chlorine ion.
Thus, the oxidation reaction which is a sort of corrosion is not
hindered. In particular, in the case where an oxygen-containing
film of iron is prepared while the ion of the reaction accelerator
such as a chlorine ion exists together, the subject effect is
large. In the case where a metal other than iron is present on the
surface, it is only required that at least a part of the portion
other than the metal other than iron is covered by the
oxygen-containing film of iron.
[0087] In the iron powder of the invention, not only a region where
(1) entire (uniform) corrosion, (2) pitting or crevice corrosion,
(3) stress corrosion cracking, or the like is generated, but also
irregularities or crevices are formed. For that reason, it is
assumed that the iron powder of the invention has hydrophilicity
and oxidation catalytic properties (for example, FeO) in its own
portion. In producing the heat generating composition, it is
important that the iron powder has an oxygen-containing film in its
own portion without relying upon mixing. In particular, in the iron
component as prepared by contact treating the iron component and
the reaction accelerator and water as essential components with an
oxidizing gas, it is thought that a reaction active part composed
mainly of an oxide, a hydroxide, a chlorine ion, a hydrogen ion,
etc. is formed, whereby exothermic reactivity and hydrophilicity
are improved and exothermic rising properties and moldability are
remarkably improved.
[0088] Furthermore, an iron powder which contains a carbon
component and/or is covered by a carbon component is preferable,
and an iron powder in which the surface of the iron powder is
partially covered by from 0.3 to 3.0% by weight of a conductive
carbonaceous substance is useful. Examples of the conductive
carbonaceous substance include carbon black and active carbon; and
examples of the iron powder include reduced iron powders, atomized
iron powders, and sponge iron powders. In particular, the case
where the conductive carbonaceous substance is active carbon and
the iron powder is a reduced iron powder is useful as a heat
generating body.
[0089] In the case of measuring the water mobility value of the
heat generating composition in the heat generating body and the
thickness and amount of wustite of the iron oxide film of iron
powder in the mixture or the heat generating composition in the
heat generating body, the heat generating composition or mixture
may be measured according to the following items.
1) Water Mobility Value:
[0090] The heat generating composition is taken out from the heat
generating body and measured according to the foregoing method of
measuring a water mobility value.
2) Thickness and Amount of Wustite of Iron Oxide Film of Iron
Powder:
[0091] A measuring sample as prepared by dispersing the heat
generating composition, the heat generating composition molded
body, the heat generating composition compression molded body or
the mixture in nitrogen-purged ion-exchanged water in a nitrogen
atmosphere, separating the iron powder using a magnet and drying
the iron powder in a nitrogen atmosphere is used.
[0092] The carbon component is not particularly limited so far as
it contains carbon as a component. Examples thereof include carbon
black, graphite, active carbon, carbon nanotubes, carbon nanohorns,
and flullerenes. Carbon which has become conductive by doping or
the like is also employable. There are enumerated active carbons as
prepared from coconut shell, wood, charcoal, coal, bone carbon,
etc. and carbons as prepared from other raw materials such as
animal products, natural gases, fats, oils, and resins. In
particular, active carbons having an adsorption retaining ability
are preferable.
[0093] Furthermore, it is not always required that the carbon
component is present alone. In the case where an iron powder
containing the carbon component and/or covered by the carbon
component is used in the heat generating composition, it is to be
noted that the heat generating composition contains the carbon
component even though the carbon component is not present
alone.
[0094] The reaction accelerator is not particularly limited so far
as it is able to promote the reaction of the heat generating
substance. Examples thereof include metal halides, nitrates,
acetates, carbonates, and metal sulfates. Examples of metal halides
include sodium chloride, potassium chloride, magnetic chloride,
calcium chloride, ferrous chloride, ferric chloride, sodium
bromide, potassium bromide, ferrous bromide, ferric bromide, sodium
iodide, and potassium iodide. Examples of nitrates include sodium
nitrate and potassium nitrate.
[0095] Examples of acetates include sodium acetate. Examples of
carbonates include ferrous carbonate. Examples of metal sulfates
include potassium sulfate, sodium sulfate, and ferrous sulfate.
[0096] As the water, one from a proper source may be employed. Its
purity and kind and the like are not particularly limited.
[0097] In the case of the heat generating composition, the content
of water is preferably from 1 to 70% by weight, more preferably
from 1 to 60% by weight, further preferably from 7 to 60% by
weight, still further preferably from 10 to 50% by weight, and even
further preferably from 20 to 50% by weight of the heat generating
composition.
[0098] Furthermore, in the case of the reaction mixture or heat
generating mixture prior to the contact treatment with an oxidizing
gas, the content of water is preferably from 0.5 to 20% by weight,
more preferably from 1 to 20% by weight, further preferably from 3
to 20% by weight, and still further preferably from 4 to 15% by
weight of the reaction mixture or heat generating mixture.
[0099] The water absorptive polymer is not particularly limited so
far as it is a resin having a crosslinking structure and having a
water absorption magnification of ion-exchanged water of 3 times or
more of the dead weight. Furthermore, a water absorptive polymer
the surface of which is crosslinked may be employed. Conventionally
known water absorptive polymers and commercial products may also be
employed.
[0100] The water absorptive polymer is not particularly limited so
far as it is a resin having a crosslinking structure and having a
water absorption magnification of ion-exchanged water of 3 times or
more of the dead weight. Furthermore, a water absorptive polymer
the surface of which is crosslinked may be employed. Conventionally
known water absorptive polymers and commercial products may also be
employed.
[0101] Examples of the water absorptive polymer include
poly(meth)acrylic acid crosslinked materials, poly(meth)acrylic
acid salt crosslinked materials, sulfonic group-containing
poly(meth)acrylic ester crosslinked materials, polyoxyalkylene
group-containing poly(meth)acrylic ester crosslinked materials,
poly(meth)acrylamide crosslinked materials, crosslinked materials
of a copolymer of a (meth)acrylic acid salt and a (meth)acrylamide,
crosslinked materials of a copolymer of a hydroxyalkyl
(meth)acrylate and a (meth)acrylic acid salt, polydioxolane
crosslinked materials, crosslinked polyethylene oxide, crosslinked
polyvinylpyrrolidone, sulfonated polystyrene crosslinked materials,
crosslinked polyvinylpyridine, saponification products of a
starch-poly(meth)acrylonitrile graft copolymer,
starch-poly(meth)acrylic acid (salt) graft crosslinked copolymers,
reaction products of polyvinyl alcohol and maleic anhydride (salt),
crosslinked polyvinyl alcohol sulfonic acid salts, polyvinyl
alcohol-acrylic acid graft copolymers, and polyisobutylene maleic
acid (salt) crosslinked polymers. These water absorptive polymers
may be used alone or in combination with two or more kinds
thereof.
[0102] Of these water absorptive polymers, water absorptive
polymers having biodegradation properties are not limited so far as
they are a biodegradable water absorptive polymer. Examples thereof
include polyethylene oxide crosslinked materials, polyvinyl alcohol
crosslinked materials, carboxymethyl cellulose crosslinked
materials, alginic acid crosslinked materials, starch crosslinked
materials, polyamino acid crosslinked materials, and polylactic
acid crosslinked materials.
[0103] The water retaining agent is not limited so far as it is
able to retain water. Examples thereof include porous materials
derived from plants having high capillary function and
hydrophilicity such as wood meal, pulp powder, active carbon, saw
dust, cotton cloth having a number of cotton fluffs, short fiber of
cotton, paper dust, and vegetable materials, water-containing
magnesium silicate based clay minerals such as active clay and
zeolite, pearlite, vermiculite, silica based porous substances,
coralline stone, and volcanic ash based substances (for example,
terraballoon, shirasu balloon, and taisetsu balloon). In order to
increase a water retaining ability and enhance a shape holding
ability of such a water retaining agent, the water retaining agent
may be subjected to a processing treatment such as baking and/or
pulverization.
[0104] The pH adjusting agent is not limited so far it is able to
adjust the pH. Examples thereof include alkali metal weak acid
salts and hydroxides and alkaline earth metal weak acid salts and
hydroxides such as Na.sub.2CO.sub.3, NaHCO.sub.3, Na.sub.3PO.sub.4,
Na.sub.2HPO.sub.4, Na.sub.5P.sub.3O.sub.10, NaOH, KOH,
Ca(OH).sub.2, Mg(OH).sub.2, and Ca.sub.3(PO.sub.4).sub.2.
[0105] The hydrogen formation inhibitor is not limited so far as it
is able to inhibit the formation of hydrogen. Examples thereof
include one member or two or more members selected from the group
consisting of sulfur compounds, oxidizing agents, alkaline
substances, sulfur, antimony, selenium, phosphorus, and tellurium.
Incidentally, examples of sulfur compounds include compounds with
an alkali metal or an alkaline earth metal, metal sulfides such as
calcium sulfide, metal sulfites such as sodium sulfite, and metal
thiosulfates such as sodium thiosulfate.
[0106] The aggregate is not limited so far as it is useful as a
filler and/or is useful for making the heat generating composition
porous. Examples thereof include fossilized coral (for example,
coral fossil and weathered coral fossil), bamboo charcoal, bincho
charcoal, silica-alumina powders, silica-magnesia powders, kaolin,
colloidal silica, pumice, silica gel, silica powders, mica powders,
clays, talc, synthetic resin powders or pellets, foamed synthetic
resins such as foamed polyesters or polyurethanes, diatomaceous
earth, alumina, and cellulose powder.
[0107] The fibrous material is an inorganic fibrous material and/or
an organic fibrous material. Examples thereof include rock wool,
glass fibers, carbon fibers, metal fibers, pulps, papers, non-woven
fabrics, woven fabrics, natural fibers such as cotton and hemp,
regenerated fibers such as rayon, semi-synthetic fibers such as
acetates, synthetic fibers, and pulverized products thereof.
[0108] The functional substance is not limited so far as it is a
substance having any function. Examples thereof include at least
one member selected from minus ion emitting substances and far
infrared ray radiating substances. The minus ion emitting substance
is not limited so far as it emits a minus ion as a result either
directly or indirectly, and examples thereof include ferroelectric
substances such as tourmaline, fossilized coral, granite, and
calcium strontium propionate, and ores containing a radioactive
substance such as radium and radon. The far infrared ray radiating
substance is not limited so far as it radiates far infrared rays.
Examples thereof include ceramics, alumina, zeolite, zirconium, and
silica.
[0109] The surfactant includes anionic surfactants, cationic
surfactants, nonionic surfactants, and ampholytic surfactants.
Especially, nonionic surfactants are preferable, and examples
thereof include polyoxyethylene alkyl ethers, alkylphenol-ethylene
oxide adducts, and higher alcohol phosphoric acid esters.
[0110] The organosilicon compound is not limited so far as it is a
compound having at least an Si--O--R bond and/or an Si--N--R bond
and/or an Si--R bond. The organosilicon compound is in the form of
a monomer, a lowly condensed product, a polymer, etc. Examples
thereof include organosilane compounds such as
methyltriethoxysilane; and dimethylsilicone oil,
polyorganosiloxane, or silicone resin compositions containing the
same.
[0111] The pyroelectric substance is not limited so far as it has
pyroelectricity. Examples thereof include tourmaline, hemimorphic
ores, and pyroelectric ores. Tourmaline or achroite which is a kind
of tourmaline is especially preferable. Examples of the tourmaline
include dravite, schorl, and elbaite.
[0112] The moisturizer is not limited so far as it is able to hold
moisture. Examples thereof include hyaluronic acid, collagen,
glycerin, and urea.
[0113] The fertilizer component is not limited so far as it is a
component containing at least one of three elements of nitrogen,
phosphorus and potassium. Examples thereof include a bone powder,
urea, ammonium sulfate, calcium perphosphate, potassium chloride,
and calcium sulfate.
[0114] The hydrophobic polymer compound is not limited so far as it
is a polymer compound having a contact angle with water of
40.degree. or more, preferably 50.degree. or more, and more
preferably 600 or more in order to improve the draining in the
composition.
[0115] The shape of the hydrophobic polymer compound is not
limited, and examples thereof include powdery, particulate,
granular, and tablet shapes. Examples of the hydrophobic polymer
compound include polyolefins such as polyethylene and
polypropylene, polyesters, and polyamides.
[0116] Examples of the heat generating aid include metal powders,
metal salts, and metal oxides such as Cu, Mn, CuCl.sub.2,
FeCl.sub.2, manganese dioxide, cupric oxide, triiron tetroxide, and
mixtures thereof.
[0117] As the metal oxide other than iron oxide, any material can
be employed so far as it does not hinder the oxidation of iron by
an oxidizing gas, and examples thereof include manganese dioxide
and cupric oxide.
[0118] The acidic substance may be any of an inorganic acid, an
organic acid, or an acidic salt. Examples thereof include
hydrochloric acid, sulfuric acid, nitric acid, acetic acid, oxalic
acid, citric acid, malic acid, maleic acid, chloroacetic acid, iron
chloride, iron sulfate, iron oxalate, iron citrate, aluminum
chloride, ammonium chloride, and hypochlorous acid.
[0119] The wettable heat generating composition molded body or the
sectional exothermic part is not limited. The shape may be a planar
shape, and examples thereof include a circular shape, an elliptical
shape, a polygonal shape, a star shape, and a flower shape. Also,
the shape may be a three-dimensional shape, and examples thereof
include a polygonal pyramidal shape, a conical shape, a frustum
shape, a spherical shape, a parallelepiped shape, a cylindrical
shape, a semi-pillar shape, a semicylindroid shape, a
semicylidrical shape, a pillar shape, and a cylindroid shape.
Furthermore, in these shapes, the corner may be rounded, thereby
processing the corner in a curvilinear or curved state, or the
central part may be provided with a concave.
[0120] Furthermore, with respect to the shape, a maximum width is
usually from 0.5 to 60 mm, preferably from 0.5 to 50 mm, more
preferably from 1 to 50 mm, further preferably from 3 to 50 mm,
still further preferably from 3 to 30 mm, even further preferably
from 5 to 20 mm, even further preferably from 5 to 15 mm, and even
still further preferably from 5 to 10 mm. Furthermore, a maximum
height is usually from 0.1 to 30 mm, preferably from 0.1 to 10 mm,
more preferably from 0.3 to 10 mm, further preferably from 1 to 10
mm, and still further preferably from 2 to 10 mm. Furthermore, a
longest length is usually from 5 to 300 mm, preferably from 5 to
200 mm, more preferably from 5 to 100 mm, further preferably from
20 to 150 mm, and still further preferably from 30 to 100 mm.
[0121] Next, the heat generating body of the invention will be
described. In the heat generating body using the wettable heat
generating composition compressed body of the invention, the
wettable heat generating composition compressed body is usually
interposed between a substrate and a covering material, and the
periphery of the wettable heat generating composition compressed
body is subjecting to seal (for example, heat seal and compression
seal), thereby obtaining a heat generating body. At this time, at
least a part of the heat generating body has air permeability.
Still further, a heat generating body capable of generating heat
upon contact with air having a different shape may be formed by
covering the heat generating body by a different packaging
material. Furthermore, there is employed a constitution in which an
adhesive is provided on a part of at least one exposed surface of
the heat generating body and when used, the heat generating body is
stuck to the skin, a cloth (for example, underwear), etc.
Incidentally, for the purpose of reinforcing the strength of an
air-permeable film or air-impermeable film which is used as a
substrate or a covering material and achieving heat insulation, a
non-woven fabric may be provided outside.
[0122] By making the thickness of the respective wettable heat
generating composition compressed bodies different, it is possible
to make temperature characteristics such as exothermic time,
exothermic rising properties and exothermic peak temperature of the
wettable heat generating composition compressed bodies different.
Thus, in the heat generating body having a sectional exothermic
part, by providing sectional exothermic parts in which these
wettable heat generating composition compressed bodies having a
different thickness are properly disposed, sectional exothermic
parts having different temperature characteristics such as
exothermic time, exothermic rising properties and exothermic peak
temperature from each other are made present. Thus, the exothermic
time, exothermic rising properties and exothermic peak temperature
of the sectional exothermic parts are altered, thereby obtaining a
heat generating body having desired temperature distribution,
exothermic time, exothermic rising properties and exothermic peak
temperature. A method for making the thickness of the respective
wettable heat generating composition compressed bodies different is
not limited. Examples thereof include a method for making the
thickness of the respective wettable heat generating composition
compressed bodies different by compressing the wettable heat
generating composition compressed bodies by using a compression
machine having a different height of a pushing part, thereby making
a degree of compression different; and a method for making the
thickness of the respective wettable heat generating composition
compressed bodies different by compressing the wettable heat
generating composition compressed bodies by using rubber rolls
having different surface elasticity, thereby making a degree of
compression different.
[0123] With respect to the shape of the heat generating body, any
shape is employable. Examples thereof include a rectangular shape,
a circular shape, an elliptical shape, a polygonal shape, a broad
bean-like shape, an eye mask-like shape, a paper lantern-like
shape, a cocoon-like shape, a gourd-like shape, a rectangular shape
with rounded corners, a square shape with rounded corners, an
egg-like shape, a boomerang-like shape, a comma-shaped bead-like
shape, a wing-like shape, a nose-like shape, a star-like shape, and
a foot-like shape.
[0124] A raw material of the substrate or covering material is not
limited so far as it functions as an accommodating bag of the heat
generating composition. Usually, raw materials which are used in
chemical body warmers or heat generating bodies can be used.
Examples of the raw material include air-impermeable raw materials,
air-permeable raw materials, water absorptive raw materials,
non-water absorptive raw materials, non-extensible raw materials,
extensible raw materials, stretchable raw materials,
non-stretchable raw materials, foamed raw materials, non-foamed raw
materials, non-heat sealable raw materials, and heat sealable raw
materials. The raw material can be properly used depending upon a
desired utility in a desired form such as films, sheets, non-woven
fabrics, woven fabrics, and composites thereof.
[0125] In general, the substrate is made of an air-impermeable film
or sheet, and the covering material is made of an air-permeable
film or sheet or non-woven fabric, and vice versa. The both may be
air-permeable. As the underlay material, an air-permeable underlay
material and an air-impermeable underlay material may be used for
different purposes.
[0126] The packaging material of the accommodating bag may be of a
single-layered structure or multilayered structure, and its
structure is not limited. Furthermore, though the packaging
material is composed of at least a substrate and a covering
material, a packaging material for laminating the heat generating
composition molded body is the substrate, and a packaging material
for covering on the heat generating composition molded body is the
covering material regardless of whether the packaging material is
air-permeable or air-impermeable. An embodiment of a multilayered
structure in which an air-impermeable packaging material is the
substrate and an air-permeable packaging material is the covering
material will be hereunder described as one example. That is, in
this embodiment, the substrate is made of layer A/layer B, layer
A/layer B/layer C, or layer A/layer B/layer C/layer D; and the
covering material is made of layer F/layer G, layer E/layer F/layer
G, or layer F/layer H/layer G. Examples of the layer A include
thermoplastic resin films (for example, polyethylene), heat seal
layers (for example, polyethylene and EVA), and water absorptive
papers; examples of the layer B include non-woven fabrics of a
thermoplastic resin (for example, nylons), non-water absorptive
papers, water absorptive papers, thermoplastic resin films (for
example, polyethylene films, polypropylene films, polyester films,
and polyamide (for example, nylons) films), wicks (for example,
non-water absorptive papers and water absorptive papers); examples
of the layer C include adhesive layers, non-water absorptive
papers, water absorptive papers, thermoplastic resin films (for
example, polyethylene), non-slip layers, and non-woven fabrics of a
thermoplastic resin (for example, polyesters and nylons); examples
of the layer D include separators, thermoplastic resin films (for
example, polyethylene), and non-woven fabrics; examples of the
layer E include heat seal layers; examples of the layer F include
porous films or perforated films made of a thermoplastic resin (for
example, polyethylene), films made of a thermoplastic resin (for
example, polyethylene), non-water absorptive papers, and water
absorptive papers; examples of the layer G include non-woven
fabrics of a thermoplastic resin (for example, polyesters and
nylons); and examples of the layer H include non-water absorptive
papers and water absorptive papers. Examples of the substrate or
covering material include heat seal layer made of polyethylene
obtained by using a metallocene catalyst/polypropylene film,
polyethylene-made heat seal layer/polypropylene film, EVA-made heat
seal layer/polypropylene film, EVA-made heat seal
layer/polypropylene film/adhesive layer/separator, EVA-made heat
seal layer/polyethylene film/nylon non-woven fabric, non-woven
fabric/porous film, heat seal layer made of polyethylene obtained
by using a metallocene catalyst/polyethylene film/nylon non-woven
fabric, heat seal layer made of polyethylene obtained by using a
metallocene catalyst/polypropylene film/polypropylene non-woven
fabric, non-woven fabric/(paper and/or perforated (provided by a
needle or laser) film)/porous film, non-woven fabric/(paper and/or
porous film)/perforated (provided by a needle or laser) film, and
non-woven fabric/(paper and/or porous film)/non-woven fabric. A
method for laminating the respective layers is not limited. The
respective layers may be directly laminated; the respective layers
may be laminated via an air-permeable adhesive layer or a
laminating agent layer; and the respective layers may be laminated
by hot melt extrusion or the like. Furthermore, in the invention,
it is to be noted that polyethylene produced by using a metallocene
catalyst is also included in the polyethylene.
[0127] For example, in the case of laminating the foregoing raw
material such as non-woven fabrics and porous films via an
air-permeable sticky layer, examples of a method for forming the
air-permeable sticky layer include a method in which a sticky
substance is fibrillated by an appropriate system such as a curtain
spray system, a melt blow system or a slot spray system for blowing
and spreading a sticky substance via hot air under heat melting and
spread and accumulated on an appropriate supporting substrate made
of a porous film, an air-permeable substrate, a separator, etc.,
thereby forming a porous sticky layer.
[0128] A thickness of each of the substrate, the covering material,
the underlay material, and the raw material constituting the same
varies depending upon the utility and is not limited. The thickness
is usually from 5 to 5,000 .mu.m, preferably from 10 to 500 .mu.m,
and more preferably from 20 to 250 .mu.m.
[0129] The air-impermeable raw material is not limited so far as it
is air-impermeable. Examples thereof include films, sheets or
coatings made of a polymer (for example, polyethylene,
polypropylene, nylons, polyacrylates, polyesters, polyvinyl
alcohols, and ethylene-vinyl acetate copolymers) and laminates
thereof with a metal (including a semiconductor) compound (for
example, silicon oxide) or composite raw materials using the
same.
[0130] Of the foregoing air-impermeable raw materials, examples of
a film having high air impermeability include films provided with a
single layer or multiple layers of a thin film having a metal
including a semiconductor or a compound thereof provided on an
air-impermeable raw material film. Examples of the metal including
a semiconductor include silicon, aluminum, and alloys or mixtures
containing such a metal. Examples of the metal (including a
semiconductor) compound include oxides, nitrides and oxynitrides of
the foregoing metals or alloys or mixtures. Examples of the layer
include silicon oxide layers, aluminum oxide layers, and silicon
oxynitride layers; layers obtained by laminating an arbitrary layer
of these layers on a polyester-made film; and layers obtained by
further laminating a stretched polyolefin film (for example, a
biaxially stretched polypropylene film) thereon.
[0131] The air-permeable raw material is not limited so far as it
is air-permeable. Examples thereof include air-permeable films (for
example, porous films and perforated films); materials having air
permeability by themselves (for example, papers and non-woven
fabrics); materials prepared by laminating at least one of papers
and air-permeable films and non-woven fabrics so as to have air
permeability; materials prepared by providing an air-impermeable
packaging material comprising a non-woven fabric having a
polyethylene film laminated thereon with fine pores by using a
needle, etc. so as to have air permeability; non-woven fabric whose
air permeability is controlled by laminating a fiber and heat
bonding under pressure; porous films; and materials prepared by
sticking a non-woven fabric onto a porous film. The "perforated
film" as referred to herein is a film prepared by providing an
air-impermeable film (for example, polyethylene films) with fine
pores by using a needle so as to have air permeability.
[0132] The air permeability is not limited so far as the heat
generation can be kept. In the case of use in usual heat
generation, the air permeability is usually from 50 to 10,000
g/m.sup.2/24 hr, preferably from 70 to 5,000 g/m.sup.2/24 hr, more
preferably from 100 to 2,000 g/m.sup.2/24 hr, and further
preferably from 100 to 700 g/m.sup.2/24 hr in terms of moisture
permeability by the Lyssy method.
[0133] When the moisture permeability is less 50 g/m.sup.2/24 hr,
the heat value is small and a sufficient thermal effect is not
obtained, and therefore, such is not preferable. On the other hand,
when it exceeds 10,000 g/m.sup.2/24 hr, the exothermic temperature
is high so that a problem in safety may possibly be generated, and
therefore, such is not preferable. However, there is no limitation
even when the moisture permeability exceeds 10,000 g/m.sup.2/24 hr
depending upon the utility, or even in the use at a moisture
permeability closed to the open system, according to
circumstances.
[0134] The stretchable packaging material is not particularly
limited so far as it is stretchable. That is, it is only required
that the stretchable packaging material is stretchable as a whole.
The stretchable packaging material may be formed of a single
material or a composite material of stretchable substrates or a
combination of a stretchable substrate and a non-stretchable
substrate.
[0135] Examples of the stretchable packaging material include
single materials (for example, natural rubbers, regenerated
rubbers, synthetic rubbers, elastomers, and stretchable shape
memory polymers) and mixtures thereof, mixed materials or blended
materials of such a stretchable raw material and a non-stretchable
raw material or fabrics constituted of a combination of these
materials, films, yarns, strands, ribbons, tapes, and stretchable
films with a scrim structure.
[0136] The porous film is not limited and can be properly selected
among porous films obtained by stretching a film made of a
polyolefin based resin (for example, polyethylene, linear low
density polyethylene, and polypropylene) or a fluorine based resin
(for example, polytetrafluoroethylene) and a filler.
[0137] The non-woven fabric is not limited. Single non-woven
fabrics of a single fiber or composite fiber made of a material
such as rayon, nylons (polyamides), polyesters, polyacrylates,
polypropylene, vinylon, polyethylene, polyurethane, cupra, cotton,
cellulose, and pulp, or laminates of blended or accumulated fiber
layers of such fibers are useful. Furthermore, from the standpoint
of production process, dry non-woven fabrics, wet non-woven
fabrics, spunbonds, spunlaces, and the like can be used. Non-woven
fabrics made of a composite fiber having a core-sheath structure
are also useful. A non-woven fabric in the side which is brought
into contact with the skin is preferably a napping (fluffy)
non-woven fabric. Also, stretchable non-woven fabrics and
non-stretchable non-woven fabrics are useful.
[0138] The water absorptive raw material is not particularly
limited so far as it is a water absorptive film or sheet.
[0139] The water absorptive raw material is not particularly
limited so far as it has water absorption properties consequently
regardless of whether or not the raw material has water absorption
properties by itself.
[0140] Specific examples thereof include water absorptive foamed
films or sheets having water absorption properties (for example,
foamed bodies of water absorptive foamed polyurethane, etc.) or
papers, non-woven fabrics or woven fabrics formed of a fiber having
water absorption properties, non-woven fabrics or woven fabrics
containing a fiber having water absorption properties, and water
absorptive materials such as water absorptive porous films or
sheets. Besides, there are enumerated materials in which regardless
of the presence or absence of water absorption properties, a water
absorbing agent is contained, impregnated, kneaded, transferred or
carried on a foamed film or sheet, a non-woven fabric, a woven
fabric or porous film or sheet, thereby imparting or increasing
water absorption properties; and materials in which regardless of
the presence or absence of water absorption properties, a water
absorptive raw material such as water absorptive foamed films or
sheets, papers, non-woven fabrics, woven fabrics, and porous films
or sheets as cut in a planar shape according to the invention is
attached to one side or both sides of the material according to the
invention, thereby imparting water absorption properties.
[0141] In particular, in the heat generating body of the invention,
for the purpose of forming the plane which is brought into contact
with the skin into a comfortable plane by imparting water
absorption properties against sweat, etc., in order that in the
case of sweating, the sweat is absorbed, it is preferable that a
packaging material in the plane which is brought into contact with
the skin is constituted of a packaging material using a non-woven
fabric or a woven fabric containing, as the major component, a
water absorptive fiber having a water retention of 20% or more.
Examples of the water absorptive fiber having a water retention of
20% or more include cottons, silks, hemps, wools, polyacrylonitrile
based synthetic fibers, polyamide based synthetic fibers, polyvinyl
alcohol based synthetic fibers, acetate fibers, triacetate fibers,
and regenerated fibers. In addition, non-woven fabrics having a
highly water absorptive polymer held in a non-woven fabric can be
used as the non-woven fabric having excellent water absorption
properties. Incidentally, non-woven fabrics or woven fabrics
containing such a fiber as the major component are relatively good
with respect to the feeling against the skin.
[0142] In addition, highly water absorptive packaging materials
having high absorption properties of sweat can be used as the
packaging material. Examples thereof include non-woven fabrics
containing a fiber whose surface is coated with a highly water
absorptive resin, non-woven fabrics containing a hollow fiber
having a number of fine pores on the surface thereof, and non-woven
fabrics containing a fiber having a capillary action by forming a
number of pouches or plural layers in the cross-sectional
shape.
[0143] Besides, non-woven fabrics or films having a water
absorptive inorganic compound held on a non-sticky surface of a
packaging material can be used. Examples thereof include non-woven
fabrics resulting from holding a powder (for example, diatomaceous
earth, zeolite, and silica gel) on a non-woven fabric and films
resulting from holding a relatively large amount of a powder (for
example, silica and alumina) on a synthetic resin (for example,
polyethylene).
[0144] Furthermore, as an example of a different heat generating
body of the invention, a pocket heat generating body having
specific physical dimension and filling characteristics, capable of
continuously generating heat over a long period of time and having
improved temperature control properties by incorporating the
wettable heat generating composition compressed body into a pocket
of a pocket-provided substrate may be formed. This pocket heat
generating body contains a wettable heat generating composition
compressed body on a basis of a specific iron oxidation chemical
reaction. This wettable heat generating composition compressed body
fills in an effective pocket capacity within the pocket heat
generating body and reduces an excessive blank capacity which is
possibly present, thereby minimizing an ability of the wettable
heat generating composition compressed body or exothermic substance
to move. Since such a pocket heat generating body has a flexible
physical dimension, it can be easily incorporated into a body
wearing implement or the like which can be adapted with various
outer shapes of the body. Accordingly, it is possible to warm the
body conveniently, comfortably and constantly. Examples thereof
include heat cells and all heat generating bodies using the same as
described in JP-T-11-508786, JP-T-11-508314, JP-T-11-512954,
JP-T-2002-514104, JP-T-2003-509120, and JP-T-2001-5075930. These
are useful in the invention, and the disclosures of the patent
documents can be totally incorporated in this description by
reference.
[0145] In this case, in the case where two or more plural pockets
are provided at intervals, a perforation may be provided in at
least one pocket.
[0146] Furthermore, with respect to the wettable heat generating
composition compressed bodies in the pocket, at least one thickness
may be different.
[0147] By making the thickness of the respective wettable heat
generating composition compressed bodies different, it is possible
make the temperature characteristics of the wettable heat
generating composition compressed body, such as exothermic time,
exothermic rising properties and exothermic peak temperature
different. Thus, in the heat generating body having a pocket, by
providing a pocket in which these wettable heat generating
composition compressed bodies having a different thickness are
properly disposed, sectional exothermic parts having different
temperature characteristics such as exothermic time, exothermic
rising properties and exothermic peak temperature from each other
are made present, thereby obtaining a heat generating body having
different exothermic time, exothermic rising properties and
exothermic peak temperature among the pockets. A method for making
the thickness of the respective wettable heat generating
composition compressed bodies different is not limited. Examples
thereof include a method for making the thickness of the respective
wettable heat generating composition compressed bodies different by
compressing the wettable heat generating composition compressed
bodies by using a compression machine having a different height of
a pushing part, thereby making a degree of compression different;
and a method for making the thickness of the respective wettable
heat generating composition compressed bodies different by
compressing the wettable heat generating composition compressed
bodies by using rubber rolls having different surface elasticity,
thereby making a degree of compression different.
[0148] Although the compressed body per se of the invention does
not have flexibility, it has integral properties. Thus, in a heat
generating body having an exothermic part in which compressed
body-containing sectional exothermic parts are provided at
prescribed intervals, it is possible to stick it to even a curved
part with a large curvature. In addition, different from the case
of a powder, the heat generating body can be produced in a uniform
thickness and the subject state can be held. Thus, it is possible
to impart a uniform thermal effect in the whole of the sticking
portion. Furthermore, since the heat generating body is free from
the movement of a powder in a bag as in a powder, it is free from
an uncomfortable feeling and has an extremely excellent feeling for
use. In particular, since the exothermic temperature and exothermic
time per a unit weight of the metal powder are extremely excellent
as compared with conventional powdery thermal materials, not only
it is possible to realize a light weight and thin-layered heat
generating body, but also it is possible to omit an air-permeable
film, a non-woven fabric, and the like. Thus, it is possible to
obtain a lightweight and thin-layered thermal sheet with an
excellent feeling for use. Incidentally, with respect to the
utility of the heat generating body of the invention, it is not
limited to a throwaway body warmer, an exothermic sheet for thermal
remedy, etc., but various utilities can be thought. Examples
thereof include exothermic sheets or thermal wet packs in which
various drugs are contained in an adhesive for the purpose of
percutaneously absorbing a medicinal component and cosmetics using
a cosmetic gelling agent as an adhesive. While the heat generating
body of a structure having an adhesive layer constituted of an
adhesive as a fixing measure has been described, the adhesive is
not always required in the invention. In that case, the thermal
material may be fixed by a stretchable bandage or a hook-and-loop
fastener such as Velcro. Incidentally, the thermal material of the
invention is sealed in an outer bag which is an air-impermeable
accommodating bag prior to the use and transported or stored.
[0149] The production process of the invention is a process of
filling a moldable heat generating composition in a mold cavity,
applying a pressure to the moldable heat generating composition
within the mold cavity and compressing it to a thickness of from 45
to 99.5% of the depth of the mold cavity. The pressure at the time
of pressurization is not particularly limited so far as the
moldable heat generating composition can be compressed to a
prescribed thickness. Furthermore, a compression jig which is used
for compression molding is not limited. Examples thereof include
elastic flat plates or rolls and flat plates or rolls having a
pushing part capable of being inserted into the mold cavity.
[0150] In the heat generating composition compressed body which is
produced by the in-mold compression, at least one of the packaging
materials is interposed between oxygen-permeable packaging
materials, and its periphery is heat sealed. For example, the heat
generating composition compressed body is laminated on a
substantially flat substrate, an air-permeable covering material is
covered thereon, and the periphery of the heat generating
composition compressed body is then heat sealed, thereby producing
a heat generating body. Furthermore, in another example, a
substrate having a pocket is used, the heat generating composition
compressed body is charged in the pocket, and a covering material
is then placed so as to cover the heat generating composition
compressed body and the substrate. The substrate and the covering
material are sealed in the periphery of the pocket having the heat
generating composition compressed body charged therein, and the
sealed pocket may be then formed as a completed heat generating
body by cutting off the substrate and the covering material.
Alternatively, for example, it can be incorporated into a body
wearing implement for knee, neck, back, etc. Such a heat generating
body or implement is sealed in an air-impermeable outer bag and
then transported or stored.
[0151] The heat generating composition compressed body is of an
arbitrary standard tablet shape such as a shallow convex surface
shape, a concave surface standard shape, a deep concave surface
shape, a flat surface shape, a flat edge part, a capsule shape with
an obliquely cut edge part, an egg-like shape, and a modified
spherical shape. The production process of the heat generating
composition compressed body is not limited to the foregoing in-mold
compression process, and any process can be employed so far as the
heat generating composition compressed body can be produced.
[0152] The "water mobility value" as referred to herein is a value
showing an amount of surplus water which can transfer to the
outside of the heat generating composition in water present in the
heat generating composition. This water mobility value will be
described below with reference to FIGS. 2 to 6.
[0153] As shown in FIG. 2, a filter paper 20 of No. 2 (second class
of JIS P3801) in which eight lines are drawn-radiating from the
central point with an interval of 45.degree. is placed on a
stainless steel plate 24 as shown in FIGS. 3 and 4; a template 21
having a size of 150 mm in length.times.100 mm in width and having
a hollow cylindrical hole 22 having a size of 20 mm in inner
diameter.times.8 mm in height is placed in the center of the filter
paper 20; a sample 23 is placed in the vicinity of the hollow
cylindrical hole 22; and a stuffer plate 17 is moved on and along
the template 21 and inserted into the hollow cylindrical hole 22
while stuffing the sample 23, thereby leveling the sample (force-in
die molding).
[0154] Next, as shown in FIG. 5, a non-water absorptive 70
.mu.m-thick polyethylene film 19 is placed so as to cover the hole
22, and a flat plate 18 made of stainless steel having a size of 5
mm in thickness.times.150 mm in length.times.150 mm in width is
further placed thereon and held for 5 minutes such that an
exothermic reaction is not caused.
[0155] Thereafter, a shown in FIG. 6, the filter paper 20 is taken
out, and an oozed-out locus of the water or aqueous solution is
read as a distance 25 (unit: mm) from a periphery 26 as an edge of
the hollow cylindrical hole to an oozed-out tip along the radiating
lines. Similarly, a distance 25 from each of the lines is read, and
eight values in total are obtained. Each of the eight values (a, b,
c, d, e, f, g and h) which are read out is defined as a measured
water content value. An arithmetic average value of the eight
measured water content values is defined as a water content value
(mm) of the sample.
[0156] Furthermore, the water content for the purpose of measuring
a real water content value is defined as a compounded water content
of the heat generating composition corresponding to the weight of
the heat generating composition having a size of 20 mm in inner
diameter.times.8 mm in height or the like, similar measurement is
conducted only with water corresponding to that water content, and
a value as calculated in the same manner is defined as a real water
content value (mm). A value obtained by dividing the water content
value by the real water content value and then multiplying with 100
is a water mobility value.
[0157] That is, the water mobility value is represented by the
following expression.
(Water mobility value)={[Water content value (mm)]/[(Real water
content value (mm))].times.100
[0158] With respect to the same sample, five points are measured,
and the five water mobility values are averaged, thereby defining
an average value thereof as a water mobility value of the
sample.
[0159] In the invention, a heat generating body can be formed only
by laminating a heat generating composition molded body obtained by
molding a heat generating composition having surplus water with a
water mobility value of from 0.01 to 20 on a substrate, covering a
covering material thereon, and sealing at least the periphery of
the heat generating composition molded body. After accommodating it
in a packaging material such as a substrate and a covering
material, it is not necessary to add water. Accordingly, since the
process is remarkably simplified, the invention is superior in view
of the costs.
[0160] In the invention, the water mobility value (0 to 100) is
preferably from 0.01 to 20, more preferably from 0.01 to 18,
further preferably from 0.01 to 15, still further preferably from
0.01 to 13, even further preferably from 1 to 13, and even still
further preferably from 3 to 13.
[0161] In a heat generating body using a heat generating
composition molded body obtained by molding a moldable heat
generating composition containing surplus water as a connecting
substance according to the invention, the heat generating
composition contains an appropriate amount of surplus water
expressed by a water mobility value of from 0.01 to 20 as the
connecting substance without using a flocculant aid, a dry binding
agent, a flocculating agent, etc.
[0162] It is assumed that when the amount of surplus water in the
heat generating composition is appropriate, the surplus water
causes hydration against hydrophilic groups in the components of
the composition due to a bipolar mutual action or hydrogen bond,
etc. and that it is present even in the surroundings of hydrophobic
groups while having high structural properties. Thus, it is assumed
that the heat generating composition becomes in a state of a mud
ball, thereby revealing moldability. This is connecting water as a
connecting substance in some meaning. Besides, there is water in a
state called as free water which can freely move, and it is thought
that when the surplus water increases, the structure is softened,
whereby the free water increases. Furthermore, controlling factors
which an iron powder causes an oxidation reaction are an amount of
existing water and a feed amount of oxygen to the surface of the
iron powder. It is said that in a degree of water adsorbing film
(less than 100 angstroms), the water is not sufficient and that the
oxidation rate is small. When the adsorbing film becomes about 1
.mu.m, the water content becomes sufficient. Furthermore, since the
thickness of the water film is thin, feed of oxygen onto the
surface of the iron powder becomes easy, whereby the oxidation rate
becomes large. It is assumed that when the film becomes thicker to
an extent that the adsorbing film exceeds 1 .mu.m, the feed amount
of oxygen is reduced. The present inventors have obtained knowledge
that the water mobility value expressing the optimal water content
at which moldability and oxidation rate in fixed levels or more are
revealed is from 0.01 to 20, leading to accomplishment of the
invention.
[0163] That is, by using an appropriate amount of surplus water,
the respective component particles are coupled with each other by a
surface tension of water, moldability is generated in the heat
generating composition, and the water does not substantially
function as a barrier layer. Thus, the heat generating composition
comes into contact with air to generate heat. In addition, by using
a heat generating composition using an active iron powder or an
active heat generating composition using an active iron powder, the
heat generating composition becomes a heat generating composition
having remarkably excellent exothermic rising properties and high
moldability. Furthermore, heat generation occurs without causing
transfer of the water in the heat generating composition molded
body as produced by a molding and laminating system into a
packaging material or water absorptive sheet. In addition, by
providing plural sectional exothermic parts of the heat generating
composition molded body as sectioned by seal parts, it is possible
to provide a heat generating body which has flexibility itself, is
excellent in installation in places where flexibility is required,
such as various places of a human body and curved bodies, and is
excellent in feeling for use.
[0164] Furthermore, in the substrate, the covering material and the
heat generating composition molded body, by temporarily adhering at
least the covering material and the heat generating composition
molded body to each other via a sticky layer and then heat sealing
the periphery of the heat generating composition molded body and
the surroundings of the heat generating body, certainty of heat
seal is improved so that it becomes possible to design to make the
production speed of a heat generating body high and make the heat
seal width small.
[0165] The "moldability" as referred to in the invention exhibits
that a molded body of the heat generating composition having a
cavity or concave die shape is formed by force-through molding
using a trimming die having a cavity or cast molding using a
concave die, whereby after molding including mold release, the
molding shape of the heat generating composition molded body is
held.
[0166] When the moldability is revealed, since the shape is held
until the heat generating composition molded article is at least
covered by a covering material and a seal part is formed between
the substrate and the covering material, sealing can be achieved in
the periphery of the shape with a desired shape. Also, since
so-called "spots" which are a collapsed piece of the heat
generating composition are not scattered in the seal part, the
sealing can be achieved without causing cutting in seal. The
presence of the spots causes insufficient sealing.
[0167] 1) Measurement Device:
[0168] With respect to the measurement device, a stainless
steel-made molding die (a plate having a size of 2 mm in
thickness.times.200 mm in length.times.200 mm in width and having a
cavity as treated by R5 in four corners of 60 mm in length.times.40
mm in width in a central part thereof) and a fixable leveling plate
are disposed above a travelable endless belt, and magnets (two
magnets having a size of 12.5 mm in thickness.times.24 mm in
length.times.24 mm in width are disposed in parallel) are disposed
under the endless belt.
[0169] The magnets should cover a region of the leveling plate and
the vicinity thereof and a region larger than a region covered by a
cut side (40 mm) vertical to the advancing direction of the cavity
of the molding die.
2) Measurement Method:
[0170] With respect to the measurement method, a stainless steel
plate having a size of 1 mm in thickness.times.200 mm in
length.times.200 mm in width is placed on the endless belt of the
measurement device, a polyethylene film having a size of 70 .mu.m
in thickness.times.200 mm in length.times.200 mm in width is placed
thereon, and a stainless steel-made molding die is further placed
thereon.
[0171] Thereafter, a leveling plate is fixed in a position of the
cavity of the molding die of 50 mm far from the end portion in the
advancing direction of the endless belt, 50 g of a heat generating
composition is then placed in the vicinity of the leveling plate
between the leveling plate and the cavity, and the heat generating
composition is filled in the cavity of the molding die while
leveling it by moving the endless belt at 1.8 m/min. After the
molding die has completely passed through the leveling plate, the
traveling of the endless belt is stopped. Next, the molding die is
removed, and a heat generating composition molded body as laminated
on the polyethylene film is observed.
3) Judgment Method:
[0172] With respect to the judgment method, in the surroundings of
the heat generating composition molded body, in the case where any
collapsed piece of the heat generating composition molded body
exceeding a maximum length of 800 .mu.m is not present and the
number of collapsed pieces of the heat generating composition
molded body having a maximum length of from 300 to 800 .mu.m is not
more than 5, it is to be noted that the heat generating composition
has moldability.
[0173] The moldability is an essential property for a heat
generating composition to be used in the molding system. If the
heat generating composition does not have moldability, it is
impossible to produce a heat generating body by the molding
system.
[0174] The "adjustment of the water content" as referred to herein
means that after contact treating the heat generating mixture with
an oxidizing gas, water or an aqueous solution of a reaction
accelerator is added. Although the amount of addition of water or
an aqueous solution of a reaction accelerator is not limited,
examples thereof include the addition of a weight corresponding to
a reduced weight by the contact treatment and the addition of a
weight such that a desired water mobility value is obtained.
[0175] Whether or nor the adjustment of the water content is
introduced may be properly determined depending upon the
utility.
[0176] The "moldability" as referred to in the invention exhibits
that a laminate of the heat generating composition having a cavity
or concave die shape can be formed by force-through molding using a
trimming die having a cavity or cast molding using a concave die
and after molding including mold release, the molding shape of the
heat generating composition molded body is held. When the
moldability is revealed, since the shape is held until the heat
generating composition molded article is at least covered by a
covering material and a seal part is formed between the substrate
and the covering material, sealing can be achieved in the periphery
of the shape with a desired shape. Also, since so-called "spots"
which are a collapsed piece of the heat generating composition are
not scattered in the seal part, sealing can be achieved without
causing cutting in seal. The presence of the spots causes
insufficient sealing.
[0177] Next, with respect to the moldability, a measurement device,
a measurement method and a judgment method will be described
below.
1) Measurement Device:
[0178] With respect to the measurement device, a stainless
steel-made molding die (a plate having a size of 2 mm in
thickness.times.200 mm in length.times.200 mm in width and having a
cavity as treated by R5 in four corners of 60 mm in length.times.40
mm in width in a central part thereof) and a fixable leveling plate
are disposed above a travelable endless belt, and magnets (two
magnets having a size of 12.5 mm in thickness.times.24 mm in
length.times.24 mm in width are disposed in parallel) are disposed
under the endless belt. The magnets should cover a region of the
leveling plate and the vicinity thereof and a region larger than a
region covered by a cut side (40 mm) vertical to the advancing
direction of the cavity of the molding die.
2) Measurement Method:
[0179] With respect to the measurement method, a stainless steel
plate having a size of 1 mm in thickness.times.200 mm in
length.times.200 mm in width is placed on the endless belt of the
measurement device, a polyethylene film having a size of 70 .mu.m
in thickness.times.200 mm in length.times.200 mm in width is placed
thereon, and a stainless steel-made molding die is further placed
thereon. Thereafter, a leveling plate is fixed in a position of the
cavity of the molding die of 50 mm far from the end portion in the
advancing direction of the endless belt, 50 g of a heat generating
composition is then placed in the vicinity of the leveling plate
between the leveling plate and the cavity, and the heat generating
composition is filled in the cavity of the molding die while
leveling it by moving the endless belt at 1.8 m/min.
[0180] After the molding die has completely passed through the
leveling plate, the traveling of the endless belt is stopped. Next,
the molding die is removed, and a heat generating composition
molded body as laminated on the polyethylene film is observed.
3) Judgment Method:
[0181] With respect to the judgment method, in the surroundings of
the heat generating composition molded body, in the case where any
collapsed piece of the heat generating composition molded body
exceeding a maximum length of 800 .mu.m is not present and the
number of collapsed pieces of the heat generating composition
molded body having a maximum length of from 300 to 800 .mu.m is not
more than 5, it is to be noted that the heat generating composition
has moldability. The moldability is an essential property for a
heat generating composition to be used in the molding system. If
the heat generating composition does not have moldability, it is
impossible to produce a heat generating body by the molding
system.
[0182] The heat generating composition of the invention has
resistance to compression. The "resistance to compression" as
referred to herein means that a heat generating composition
compressed body obtained by compressing a heat generating
composition molded body as accommodated in a molding die within the
die to such an extent that the thickness is 70% of the die
thickness holds 80% or more of exothermic rising properties of the
exothermic rising properties of the heat generating composition
molded body before compression (a difference in temperature between
one minute and 3 minutes after starting a heat generation test of
the heat generating composition).
[0183] Here, the measurement method of exothermic rinsing
properties for the resistance to compression will be described
below.
1. Heat Generating Composition Molded Body:
[0184] 1) A magnet is provided in the vicinity of a central part of
the back side of a polyvinyl chloride-made supporting plate (3 mm
in thickness.times.600 mm in length.times.600 mm in width) of a
footed supporting table so as to cover a cavity shape of a molding
die.
[0185] 2) A temperature sensor is placed on the central part the
surface of the supporting plate.
[0186] 3) A polyethylene film (25 .mu.m in thickness.times.250 mm
in length.times.200 mm in width) as provided with an adhesive layer
having a thickness of about 80 .mu.m is stuck onto the supporting
plate via a sticky layer such that the center of the polyethylene
film is positioned at the sensor.
[0187] 4) On an underlay plate (280 mm in length.times.150 mm in
width.times.50 .mu.m to 2 mm in thickness), a polyethylene film
(230 mm in length.times.155 mm in width.times.25 .mu.m to 100 .mu.m
in thickness) is placed such that one end of the polyethylene film
is projected by about 20 mm outside the underlay plate and that one
end thereof in the length direction is substantially coincident
with one end of the underlay plate.
[0188] 5) A template (230 mm in length.times.120 mm in
width.times.3 mm in thickness) having a cavity (80 mm in
length.times.50 mm in width.times.3 mm in height) is placed on the
polyethylene film placed on the underlay plate; a template is
placed on the polyethylene film such that one end thereof in the
length direction is fitted to one end where the underlay plate and
the polyethylene film are coincident with each other and that in
the width direction, one end part of the width of the template is
placed at a position of the central part by about 20 mm far from an
opposing end to the side where the polyethylene film is projected
outward from the underlay plate. Next, the resulting assembly is
placed on the supporting plate together with the underlay
plate.
[0189] 6) A sample is placed in the vicinity of the cavity; a
force-in die plate is moved along the molding die; the sample is
charged into the cavity while stuffing; and the sample is leveled
while stuffing along the template plane (force-in die molding),
thereby filling the sample in the die.
[0190] 7) Next, the magnet beneath the supporting plate is removed;
the end portion of the projected polyethylene film is pressed; the
underlay plate is removed; and the temperature measurement is
started.
2. Heat Generating Composition Compressed Body:
[0191] 1) to 6) are the same as in the case of the heat generating
composition molded body.
[0192] 8) A die having a convex having a thickness of 0.9 mm which
can substantially tightly come into the cavity in relation of the
cavity with an unevenness is fitted to the cavity and compressed by
a roll press or plate press to prepare a heat generating
composition compressed body having a thickness of 2.1 mm
(compressed to 70% of the die thickness) within the die.
[0193] 9) The resulting assembly is placed on the supporting plate
together with the underlay plate; the magnet beneath the supporting
plate is removed; the end portion of the projected polyethylene
film is pressed; the underlay plate is removed; and the temperature
measurement is started.
[0194] With respect to the measurement of the exothermic
temperature, the temperature is measured for 5 minutes at a
measurement timing of 2 seconds using a data collector, and
resistance to compression is judged in terms of a difference in
temperature between after elapsing one minute and after elapsing 3
minutes.
[0195] The thickness after compression is preferably from 50 to
99.5%, more preferably from 60 to 99.5%, and further preferably
from 60 to 95% of the die thickness.
[0196] Incidentally, in the invention, it is to be noted that the
heat generating composition molded body includes a heat generating
composition compressed body.
[0197] The particle size of the water-insoluble solid component
constituting the moldable heat generating composition of the
invention is not limited so far as the heat generating composition
has moldability. In the case where any one of length, width and
height as the size of the heat generating composition molded body
as molded from the heat generating composition is small, the
moldability is improved by making the particle size small.
[0198] In addition, it is preferable in view of molding that the
particle size of the solid component constituting the moldable heat
generating composition is small. A maximum particle size of the
water-insoluble solid component exclusive of the reaction
accelerator and water in the components constituting the moldable
heat generating composition is preferably not more than 2.5 mm,
more preferably not more than 930 .mu.m, further preferably not
more than 500 .mu.m, still further preferably not more than 300
.mu.m, even further preferably not more than 250 .mu.m, and even
still further preferably not more than 200 .mu.m. Moreover, 80% or
more of the particle size of the solid component is usually not
more than 500 .mu.m, preferably not more than 300 .mu.m, more
preferably not more than 250 .mu.m, further preferably not more
than 200 .mu.m, still further preferably not more than 150 .mu.m,
and even further preferably not more than 100 .mu.m.
[0199] Incidentally, with respect to the particle size of the
water-insoluble solid component, separation is conducted using a
sieve, and the particle size of the component which has passed
through the sieve is calculated from an opening of the sieve. That
is, sieves of 8, 12, 20, 32, 42, 60, 80, 100, 115, 150, 200, 250
and 280 meshes and a receiving dish are combined in this order from
up to down. About 50 g of water-insoluble solid component particles
are placed on the uppermost 8-mesh sieve and shaken for one minute
using an automatic shaker. Weights of the water-insoluble solid
component particles on each of the sieves and the receiving dish
are weighed. The total amount thereof is defined as 100%, and the
particle size distribution is determined from weight fractions.
When the sum of all receiving dishes under the sieve of a specific
mesh size becomes 100% which is the total sum of the particle size
distribution, the size (.mu.m) calculated from the opening of the
specific mesh is defined as the particle size of the
water-insoluble solid component. Incidentally, each of the mesh
sieves may be combined with other mesh sieves. Here, the particles
which have passed through a 16-mesh sieve are defined to have a
particle size of not more than 1 mm; the particles which have
passed through a 20-mesh sieve are defined to have a particle size
of not more than 850 .mu.m; the particles which have passed through
a 48-mesh sieve are defined to have a particle size of not more
than 300 .mu.m; the particles which have passed through a 60-mesh
sieve are defined to have a particle size of not more than 250
.mu.m; the particles which have passed through a 65-mesh sieve are
defined to have a particle size of not more than 200 .mu.m; the
particles which have passed through an 80-mesh sieve are defined to
have a particle size of not more than 180 .mu.m; the particles
which have passed through a 100-mesh sieve are defined to have a
particle size of not more than 150 .mu.m; the particles which have
passed through a 115-mesh sieve are defined to have a particle size
of not more than 120 .mu.m; the particles which have passed through
a 150-mesh sieve are defined to have a particle size of not more
than 100 .mu.m; and the particles which have passed through a
250-mesh sieve are defined to have a particle size of not more 63
.mu.m, respectively. The same is applicable to mesh sizes of less
than these mesh sizes.
[0200] Furthermore, the heat generating composition can be
classified into a powder, a granulate heat generating composition
(having a water mobility value of less than 0.01), a moldable heat
generating composition (having a water mobility value of from 0.01
to 20), and a sherbet-like heat generating composition (having a
water mobility value exceeding 20 but not more than 50) depending
upon the state of adjustment of the water content or surplus water.
The heat generating composition as classified depending upon the
water mobility value is as described previously.
[0201] The "contact treatment with an oxidizing gas" as referred to
herein is a method in which a mixture or heat generating
composition having components of the heat generating composition
mixed therein is brought into continuous or intermittent contact
with an oxidizing gas (for example, oxygen and air) in an oxidizing
gas atmosphere or by blowing an oxidizing gas or other means,
thereby partially oxidizing the iron component. A method for
determining a degree of oxidation is not limited. Examples thereof
include a method in which a degree of contact of the mixture or
heat generating composition with an oxidizing gas is determined by
the water mobility value of the mixture or heat generating
composition, the contact time with the oxidizing gas, the
exothermic temperature rise rate at the time of contact, the
exothermic temperature at the time of contact, the maximum
exothermic temperature at the time of contact, a prescribed
temperature as dropped after reaching the maximum exothermic
temperature at the time of contact, or a combination thereof,
thereby determining a degree of oxidation.
[0202] For examples, the following methods are preferable.
[0203] (1) A heat generating composition having a water mobility
value of not more than 20 (for example, less than 0.01 or from 0.01
to 20) is exposed to air while fluidizing by stirring or the like
to cause self heat generation, intercepted from air for a desired
period of time until the temperature exceeds a maximum exothermic
temperature and then returned to room temperature, thereby forming
a heat generating composition. In particular, a contact treatment
with an oxidizing gas by exposing a heat generating mixture or heat
generating composition having a water mobility value of less than
0.01 to air while stirring, thereby causing self heat generation is
preferable.
[0204] (2) A heat generating composition having a water mobility
value exceeding 20 is brought into contact with air and intercepted
from air for a desired period of time, thereby forming a heat
generating composition.
[0205] (3) Water or a reaction accelerator aqueous solution is
added to the heat generating composition as obtained in either one
of (1) or (2), and the water content of the mixture is adjusted,
followed by mixing to form a heat generating composition having a
desired water mobility value. The weight of the water or reaction
accelerator aqueous solution to be added for the purpose of
adjusting the water content is not limited. Examples thereof
include a weight as reduced against the weight of the mixture or
heat generating composition prior to exposing to air, namely prior
to causing self heat generation, or a weight corresponding to the
weight exceeding it. If desired, the temperature state of the
mixture and the heat generating composition may be controlled prior
to the contact treatment and/or at the time of contact treatment by
warming the mixture, warming the heat generating composition and
warming a reaction vessel, heat insulation, cooling, or a
combination thereof. In this way, a heat generating composition
having remarkably excellent exothermic rising properties can be
obtained.
[0206] The following methods are enumerated.
[0207] (1) A heat generating composition having a water mobility
value of not more than 20 (for example, less than 0.01 or from 0.01
to 30) is exposed to air while fluidizing by stirring or the like
to cause self heat generation, intercepted from air for a desired
period of time until the temperature exceeds a maximum exothermic
temperature and then returned to room temperature, thereby forming
a heat generating composition. In particular, a contact treatment
with an oxidizing gas by exposing a heat generating mixture or heat
generating composition having a water mobility value of less than
0.01 to air while stirring, thereby causing self heat generation is
preferable.
[0208] (2) A heat generating composition having a water mobility
value exceeding 20 is brought into contact with air and intercepted
from air for a desired period of time, thereby forming a heat
generating composition.
[0209] (3) Water or a reaction accelerator aqueous solution is
added to the heat generating composition as obtained in either one
of (1) or (2), and the water content of the mixture is adjusted,
followed by mixing to form a heat generating composition having a
desired water mobility value. The weight of the water or reaction
accelerator aqueous solution to be added for the purpose of
adjusting the water content is not limited. Examples thereof
include a weight as reduced against the weight of the mixture or
heat generating composition prior to exposing to air, namely prior
to causing self heat generation, or a weight corresponding to the
weight exceeding it. If desired, the temperature state of the
mixture and the heat generating composition may be controlled prior
to the contact treatment and/or at the time of contact treatment by
warming the mixture, warming the heat generating composition and
warming a reaction vessel, heat insulation, cooling, or a
combination thereof. In this way, a heat generating composition
having remarkably excellent exothermic rising properties can be
obtained.
[0210] As the "oxidizing gas" as referred to herein, any substance
may be employed so far as it is gaseous and oxidizing. Examples
thereof include an oxygen gas, air, and a mixed gas of an inert gas
(for example, a nitrogen gas, an argon gas, and a helium gas) and
an oxygen gas. Of these, air is especially preferable.
[0211] So far as the atmosphere of the contact treatment region
does not become deficient in oxygen and an oxidation reaction of
the iron component is caused, a temperature of the oxidizing gas, a
temperature of the contact treatment and a time of the contact
treatment are not limited and may be properly determined depending
upon the desire. The temperature of the oxidizing gas is preferably
from 0 to 200.degree. C., more preferably from 10 to 150.degree.
C., and further preferably from 20 to 100.degree. C. Furthermore,
the treatment time is preferably from one second to 10 minutes,
more preferably from 5 seconds to 7 minutes, and further preferably
from 15 seconds to 5 minutes. In the step, it is preferable that
the reaction time is short.
[0212] The amount of the oxidizing gas to be used may be adjusted
depending upon the kind of the oxidizing gas, the kind and particle
size of the iron powder, the water content, the treatment
temperature, the treatment method, and the like. In the case of
using air, the amount of air is preferably from 1 to 1,000
liters/min per 200 g of the iron powder under one atmosphere at
100.degree. C. In the case of other oxidizing gas, the amount of
the oxidizing gas may be reduced into the concentration of oxygen
on the basis of the case of air.
[0213] If desired, an acidic substance or a peroxide may be added
at the time of the contact treatment with an oxidizing gas.
Examples of the peroxide include hydrogen peroxide and ozone.
[0214] The "iron oxide film" as referred to herein is a film made
of oxygen-containing iron such as iron oxide, hydroxide or
oxyhydroxide.
[0215] The "thickness of the iron oxide film" as referred to herein
means a portion in which in the case of sputtering the surface of
the iron powder with Ar at a sputtering rate of 11 nm/min as
reduced into Fe in the depth direction by using the Auger electron
spectroscopy, a ratio (Io/Ii) of a peak intensity of 0 (Io) to a
peak intensity of Fe (Ii) is 0.05 or more. Accordingly, the
thickness of the oxygen-containing film of iron of the invention is
a distance, as reduced into Fe, from the surface of the iron powder
to a depth at which (Io/Ii) is 0.05. With respect to the
measurement condition of the Auger electron spectroscopy, the
sputtering time is 15 minutes, and the sputtering rate is 11 nm/min
(as reduced into Fe). With a lapse of the sputtering time in the
Auger electron spectroscopy, Io decreases, whereas Ii increases. By
reducing the sputtering time from the surface of the iron powder to
a depth at which (Io/Ii) is 0.05 into a thickness, the thickness of
the iron oxide film can be calculated.
[0216] The "amount of wustite" as referred to herein is an amount
expressed by % according to the following expression from an
integrated intensity of peaks of a (110) plane of iron (.alpha.Fe)
and an integrated intensity of peaks of a (220) plane of FeO
(wustite) by using an X-ray diffraction device.
[Amount of wustite (%)]=100.times.KFeO/(K.alpha.Fe)
[0217] KFeO: Integrated intensity of peaks of a (220) plane of FeO
(wustite)
[0218] K.alpha.Fe: Integrated intensity of peaks of a (110) plane
of iron (.alpha.Fe)
[0219] An amount of wustite is usually from 2 to 50% by weight,
preferably from 5.01 to 50% by weight, more preferably from 5.01 to
40% by weight, further preferably from 6 to 40% by weight, still
further preferably from 7 to 30% by weight, and even further
preferably from 7 to 25% by weight. Even when the amount of wustite
exceeds 50% by weight, though the exothermic rising properties are
satisfactory, an exothermic duration becomes short. When the amount
of wustite is less than 2% by weight, the exothermic rising
properties become dull.
[0220] The "active iron powder" as referred to herein is an iron
powder having a region where oxygen and iron are present and a
region whose thickness is 3 nm or more by the Auger electron
spectroscopy and where oxygen is not present or iron is present.
Alternatively, the active iron powder is an iron powder having a
content of wustite of from 2 to 50% by weight in terms of an X-ray
peak intensity ratio to iron. Furthermore, when the active iron
powder is prepared by using a mixture containing an iron powder and
at least any one of other essential components (for example, a
carbon component, a reaction accelerator, and water), in the case
where as a result of separating the iron powder from the mixture
after the preparation by using a magnet, etc. and providing as a
sample for measurement by the Augur electron spectroscopy, the iron
powder has a region where oxygen and iron are present, a thickness
of that region is 3 nm or more, and the iron powder has a region of
an oxygen-free iron component in at least one region selected from
a central part region of the iron powder where at least oxygen and
iron are present and a region beneath the iron oxide film, the
subject iron powder is defined to be an active iron powder.
Alternatively, when as a result of determining the amount of
wustite by using an X-ray diffraction device, it falls within the
range of from 2 to 50% by weight or more in terms of an X-ray peak
intensity ratio to iron, the subject iron powder is defined to be
an active iron powder.
[0221] The "heat generating mixture" as referred to herein is a
material obtained by subjecting a reaction mixture containing, as
essential components, an iron powder, a carbon component, a
reaction accelerator and water and having a water content of from 1
to 30% by weight and a water mobility value of less than 0.01 to a
contact treatment with an oxidizing gas under circumstances at
0.degree. C. or higher, thereby regulating a temperature rise at
1.degree. C. or higher within 10 minutes. So far as some change is
caused in the reaction mixture by the contact treatment with an
oxidizing gas, the iron powder is not always required to be
oxidized. However, it is preferable that the iron powder is
oxidized. In that case, it is preferable that the iron powder
becomes an active iron powder.
[0222] The "active heat generating composition" as referred to
herein is a heat generating composition corresponding to any one of
the following (1) to (3).
[0223] (1) A heat generating composition prepared by contact
treating a reaction mixture containing, as essential components, an
iron powder, a carbon component, a reaction accelerator and water
with an oxidizing gas, or by subjecting the oxidizing gas and the
contact treated mixture to adjustment of the water content by the
addition of water or a reaction accelerator aqueous solution.
[0224] (2) A heat generating composition prepared by contact
treating a reaction mixture containing, as essential components, an
iron powder, a carbon component, a reaction accelerator and water
and having a water content of from 1 to 30% by weight and a water
mobility value of less than 0.01 with an oxidizing gas under
circumstances at 0.degree. C. or higher, thereby regulating a
temperature rise at 1.degree. C. or higher within 10 minutes, or by
subjecting the oxidizing gas and the contact treated mixture to
adjustment of the water content by the addition of water or a
reaction accelerator aqueous solution.
[0225] (3) A heat generating composition containing, as essential
components, an iron powder, a carbon component, a reaction
accelerator and water, wherein an iron powder containing from 20 to
100% of an active iron powder is used as the iron powder.
[0226] The "moldable heat generating composition" as referred to
herein is a heat generating composition which contains, as
essential components, an iron powder, a carbon component, a
reaction accelerator and water but does not contain a flocculant
aid, a flocculant, an agglomeration aid, a dry binder, a dry
binding agent, a dry binding material, a sticky raw material, a
thickener, an excipient, an alcohol, a crosslinking agent and a
plasticizer, contains surplus water so as to have a water mobility
value of from 0.01 to 20 and has moldability due to the surplus
water as a connecting substance, in which the water in the heat
generating composition does not function as a barrier layer, the
heat generating composition being capable of causing an exothermic
reaction upon contact with air.
[0227] The "perforation" as referred to in the invention includes
one which is intermittently cut for improving flexural properties
of the sectioned part and one which is intermittently cut such that
cutting by hand is possible. Its degree is not limited but is
determined depending upon the desire. The perforation may be
provided in all sectioned parts or may be partially provided. The
shape is not particularly limited, and examples thereof include a
circle, an ellipse, a rectangle, a square, and a cut line (linear
shape). For example, in the perforation which is intermittently cut
such that cutting by hand is possible, a circular hole having an
aperture of from +10 to 1,200 .mu.m can be enumerated. The aperture
of the hole is more preferably from +20 to 500 .mu.m. When the
aperture of the hole becomes .phi.20 .mu.m or less, cutting
properties by hand may possibly be deteriorated due to an increase
of the cutting strength of the film, or breakage or fray on the cut
surface tends to be generated; and when the aperture of the hole is
less than +10 .mu.m, such a tendency especially becomes remarkable,
and therefore, such is not preferable. On the other hand, when the
aperture of the hole becomes .phi.500 .mu.m or more, shape
destruction such as breakage may possibly be introduced due to a
lowering of the cutting strength, and stability tends to be lowered
due to a lowering of the workability or line aptitude at the time
of production, oozing, or vaporization and volatilization; and when
the aperture of the hole exceeds .phi.1,200 .mu.m, such a tendency
especially becomes remarkable, and therefore, such is not
preferable.
[0228] It is preferable that the holes are positioned lined up in
the length and width. Furthermore, a shortest space between outer
peripheries of the adjacent holes in the length and width is
preferably from 10 to 2,000 .mu.m, more preferably from 10 to 1,500
.mu.m, further preferably from 20 to 1,000 .mu.m, still further
preferably from 20 to 500 .mu.m, and even further preferably from
20 to 200 .mu.m. When the shortest space between outer peripheries
of the adjacent holes in the length and width is less than 10
.mu.m, shape destruction such as breakage may possibly be
introduced due to a lowering of the cutting strength and a lowering
of the workability or line aptitude at the time of production is
found, and therefore, such is not preferable. On the other hand,
when the shortest space between outer peripheries of the adjacent
holes in the length and width exceeds 2,000 .mu.m, cutting
properties by hand may possibly be deteriorated due to an increase
of the cutting strength of the film and breakage or fray on the cut
surface tends to be generated, and therefore, such is not
preferable. That is, the cutting properties by hand are remarkably
improved by a balance between the aperture of the processed hole
and the shortest space of outer peripheries of the adjacent holes
in the length and width.
[0229] The hole may be a cut line, and its length may be a length
corresponding to the aperture. A shortest space between ends of the
adjacent cut lines in the length and width is corresponding to the
shortest space between outer peripheries of the adjacent holes.
[0230] For example, an aperture of the hole of from +10 to 2,000
.mu.m is corresponding to a length of from 10 to 2,000 .mu.m, and a
shortest space between outer peripheries of the adjacent holes in
the length and width of from 10 to 2,000 .mu.m is corresponding to
a shortest space between ends of the adjacent cut lines in the
length and width of from 10 to 2,000 .mu.m.
[0231] The fixing means is not limited so far as it has capability
for fixing a thermal packaging body for joint surroundings or a
material having an exothermic part to a prescribed part.
[0232] As the fixing means, an adhesive layer, a hook and eye, a
hook and button, a hook and loop fastener such as Velcro, a magnet,
a band, a string, and combination thereof can be arbitrarily
used.
[0233] Incidentally, in the case of a band, fixing means for
adjustment may be further constructed by a combination of a hook
and loop fastener and an adhesive layer.
[0234] Here, the "hook and loop fastener" as referred to herein has
a fastening function by a combination of a loop as a female
fastener with a male fastener capable of fastening the female
fastener thereto, which is known as trade names such as Magic Tape
(a registered trademark), Magic Fastener (a registered trademark),
Velcro Fastener, and Hook and Loop Tape. Examples of the material
having a loop function include non-woven fabrics and woven fabrics
of napped or hole-containing yarns. Such a material having a loop
function (female fastener function) may be covered on the surface
of a paddling forming the band, or the band may be constructed of
such a material itself. Although the hook member which is the male
fastener member is not particularly limited, examples thereof
include hook members formed of a polyolefin based resin (for
example, polyethylene and polypropylene), a polyamide, a polyester,
etc. Although the shape of the hook is not particularly limited, a
hook having a cross-sectional shape such as an I type, an inverted
L type, an inverted J type, and a so-called mushroom type is
preferable because it is easily hooked by the loop and does not
give an extreme stimulus to the skin. Incidentally, the hook may be
adhered to the entire area of a fastening tape, and only the hook
may be used as a fastening tape while omitting a tape
substrate.
[0235] The adhesive layer may contain at least one member selected
from additional components consisting of a water retaining agent, a
water absorptive polymer, a pH adjusting agent, a surfactant, an
organosilicon compound, a hydrophobic polymer compound, a
pyroelectric substance, an antioxidant, an aggregate, a fibrous
material, a moisturizer, a functional substance, and a mixture
thereof.
[0236] The adhesive of the invention is classified into a
non-hydrophilic adhesive, a mixed adhesive, and a hydrophilic
adhesive (for example, a gel).
[0237] The adhesive constituting the adhesive layer is not limited
so far as it has an adhesive strength necessary for adhering to the
skin or clothes. Adhesives of every form such as a solvent based
adhesive, an aqueous adhesive, an emulsion type adhesive, a hot
melt type adhesive, a reactive adhesive, a pressure-sensitive
adhesive, a non-hydrophilic adhesive, and a hydrophilic adhesive
are employable.
[0238] The adhesive layer includes one layer of a non-hydrophilic
adhesive constituted of the non-hydrophilic adhesive and
non-hydrophilic adhesive layers constituted of the non-hydrophilic
adhesive.
[0239] It is to be noted that a material whose water absorption
properties are improving by containing a water absorptive polymer
or a water retaining agent in the non-hydrophilic adhesive layer is
dealt as the non-hydrophilic adhesive layer.
[0240] A hot melt based adhesive may be provided between the
hydrophilic adhesive layer and a substrate or a covering
material.
[0241] Furthermore, in the case where the hydrophilic adhesive is
provided in a thermal packaging body for joint surroundings, there
is no limitation. After seal treating a thermal packaging body for
joint surroundings, a hydrophilic adhesive layer may be provided in
the thermal packaging body for joint surroundings.
[0242] Furthermore, the adhesive layer may or may not have air
permeability and may be properly selected depending upon the
utility. With respect to the air permeability, the adhesive layer
may be air-permeable as a whole. Examples thereof include an
adhesive layer having air permeability as a whole of a region in
which an adhesive is partially present and a portion where no
adhesive is present is partially present.
[0243] In laminating an adhesive on an air-permeable substrate
and/or a covering material in a stratiform state as it is, examples
of a method for keeping its air permeability include a method in
which an adhesive layer is partially laminated by printing or
transferring an adhesive, thereby forming a non-laminated part as
an air-permeable part; a method in which an adhesive is transferred
in one direction while drawing a circle in a filament-like form or
properly moved in the two-dimensional directions by transferring in
a zigzag manner, whereby a space of the filament-like adhesive
keeps air permeability or moisture permeability or the adhesive is
foamed; and a method for forming a layer by a melt blow system.
[0244] Examples of the adhesive which constitutes the
non-hydrophilic adhesive layer include acrylic adhesives, polyvinyl
acetate based adhesives (for example, vinyl acetate resin based
emulsions and ethylene-vinyl acetate resin based holt melt
adhesives), polyvinyl alcohol based adhesives, polyvinyl acetal
based adhesives, vinyl chloride based adhesives, polyamide based
adhesives, polyethylene based adhesives, cellulose based adhesives,
chloroprene (neoprene) based adhesives, nitrile rubber based
adhesives, polysulfide based adhesives, butyl rubber based
adhesives, silicone rubber based adhesives, styrene based adhesives
(for example, styrene based hot melt adhesives), rubber based
adhesives, and silicone based adhesives. Of these, rubber based
adhesives, acrylic adhesives, and adhesives containing a hot melt
based polymer substance for the reasons that they are high in the
adhesive strength, are cheap, are good in long-term stability, and
are small in reduction of the adhesive strength even by providing
heat.
[0245] In addition to the base polymer, if desired, the adhesive
may be compounded with other components such as tackifiers (for
example, petroleum resins represented by rosins, chroman-indene
resins, hydrogenated petroleum resins, maleic anhydride-modified
rosins, rosin derivatives, and C-5 based petroleum resins), phenol
based tackifiers (especially, tackifiers having an aniline point of
not higher than 50.degree. C.; for example, terpene phenol based
resins, rosin phenol based resins, and alkylphenol based resins),
softeners (for example, coconut oil, castor oil, olive oil,
camellia oil, and liquid paraffin), softeners, anti-aging agents,
fillers, aggregates, adhesion adjusting agents, adhesion modifiers,
coloring agents, anti-foaming agents, thickeners, and modifiers,
thereby improving performance such as an improvement in adhesion to
nylon-made clothes and mixed yarn clothes.
[0246] Examples of the hot melt based adhesive include known hot
melt based adhesives imparted with adhesion. Specific examples
thereof include styrene based adhesives made of, as a base polymer,
an A-B-A type block copolymer (for example, SIS, SBS, SEBS, and
SIPS), vinyl chloride based adhesives made of, as a base polymer, a
vinyl chloride resin, polyester based adhesives made of, as a base
polymer, a polyester, polyamide based adhesives made of, as a base
polymer, a polyamide, acrylic adhesives made of, as a base polymer,
an acrylic resin, polyolefin based adhesives made of, as a base
polymer, a polyolefin (for example, polyethylene, super low density
polyethylene, polypropylene, ethylene-.alpha.-olefin copolymers,
and ethylene-vinyl acetate copolymers), 1,2-polybutadiene based
adhesives made of, as a base polymer, 1,2-polybutadiene, and
polyurethane based adhesives made of, as a base polymer,
polyurethane; adhesives made of a modified body of the foregoing
adhesive whose adhesion is improved or whose stability is changed;
and mixtures of two or more kinds of these adhesives. Adhesive
layers constituted of a foamed adhesive and adhesive layers
constituted of a crosslinked adhesive can also be employed.
[0247] The non-aromatic hot melt based adhesive is not limited so
far as it is made of, as a base polymer, a hot melt based adhesive
not containing an aromatic ring. Examples thereof include olefin
based hot melt based adhesives and acrylic hot melt based
adhesives. As the non-aromatic polymer which is the base polymer
not containing an aromatic ring, there are enumerated polymers or
copolymers of an olefin or a diene. Examples thereof include olefin
polymers. The olefin polymer includes polymers or copolymers of
ethylene or an .alpha.-olefin. Also, polymers resulting from adding
a diene (for example, butadiene and isoprene) as other monomer
thereto may be employed.
[0248] The .alpha.-olefin is not limited so far as it is a monomer
having a double bond in the terminal thereof. Examples thereof
include propylene, butene, heptane, hexene, and octene.
[0249] The "aromatic hot melt based adhesive" as referred to herein
is a hot melt based adhesive whose base polymer contains an
aromatic ring. Examples thereof include styrene based hot melt
based adhesives represented by A-B-A type block copolymers.
[0250] In the foregoing A-B-A type block copolymers, the A block is
a non-elastic polymer block made of a monovinyl substituted
aromatic compound A such as styrene and methylstyrene; and the B
block is an elastic polymer block made of a conjugated diene such
as butadiene and isoprene. Specific examples thereof include a
styrene-butadiene-styrene block copolymer (SBS), a
styrene-isoprene-styrene block copolymer (SIS), and hydrogenated
types thereof (for example, SEBS and SIPS), and mixtures
thereof.
[0251] As a countermeasure for preventing a lowering of adhesive
strength caused due to an increase of water of the non-hydrophilic
adhesive layer, an adhesive layer obtained by further compounding a
water absorptive polymer in the non-hydrophilic adhesive can be
used.
[0252] The hydrophilic adhesive which constitutes the hydrophilic
adhesive layer is not particularly limited so far as it contains a
hydrophilic polymer or a water-soluble polymer as the major
component, has adhesion and is hydrophilic as an adhesive.
[0253] Examples of the constitutional components of the hydrophilic
adhesive include hydrophilic polymers (for example, polyacrylic
acid), water-soluble polymers (for example, poly(sodium acrylate)
and polyvinylpyrrolidone), crosslinking agents (for example, dry
aluminum hydroxide and meta-silicic acid aluminic acid metal
salts), softeners (for example, glycerin and propylene glycol),
higher hydrocarbons (for example, soft liquid paraffin and
polybutene), primary alcohol fatty acid esters (for example,
isopropyl myristate), silicon-containing compounds (for example,
silicone oil), fatty acid glycerin esters (for example
monoglycerides), oily components (for example, vegetable oils such
as olive oil), antiseptics (for example, methyl p-hydroxybenzoate
and propyl p-hydroxybenzoate), solubilizing agents (for example,
N-methyl-2-pyrrolidone), thickeners (for example, carboxymethyl
cellulose), surfactants (for example, polyoxyethylene hardened
castor oil and sorbitan fatty acid esters), hydroxycarboxylic acid
(for example, tartaric acid), excipients (for example, light
silicic anhydride, water absorptive polymers, and kaolin),
moisturizers (for example, D-sorbitol), stabilizers (for example,
sodium edetate, p-hydroxybenzoic acid esters, and tartaric acid),
crosslinking type water absorptive polymers, boron compounds (for
example, boric acid), and water. They may be used as an arbitrary
combination.
[0254] A temporary adhering seal part is formed via a sticky layer.
An adhesive which constitutes the sticky layer is a layer formed of
a polymer composition which is tacky at the normal temperature and
is not limited so far as it can be heat sealed after temporary
adhesion.
[0255] Furthermore, the foregoing adhesives of the sticky layer can
be used as the adhesive which constitutes the sticky layer as used
for temporary adhesion. Of these, non-hydrophilic adhesives are
preferable. With respect to the adhesive constituting the adhesive
layer, it is preferable that the adhesive is well compatible with a
heat seal material constituting a heat seal and that a melting
point of the base polymer of the adhesive is not higher than a
melting point of the heat seal material. Hot melt based adhesives
are especially preferable for hot melt based bonding agents.
Furthermore, in the case where the heat seal material is an olefin
based raw material, preferred examples thereof include olefin based
adhesives.
[0256] A bonding layer for fixing the air permeability adjusting
material is constituted of a bonding agent or an adhesive which is
usually used. In particular, an adhesive is useful, and the
foregoing adhesives for constituting the adhesive layer can be
used.
[0257] Furthermore, a method for providing a bonding layer is not
limited so far as the air permeability adjusting material can be
fixed. The bonding layer may be entirely provided or partially or
intermittently provided. Examples of its shape include various
shapes such as a network-like shape, a stripe-like shape, a
dot-like shape, and strip-like shape.
[0258] Furthermore, in the case where an adhesive layer is employed
as the hydrophilic adhesive layer, if there is a difference in a
water retaining force between the hydrophilic adhesive layer and
the heat generating composition molded body, transfer of water
occurs via a packaging material present therebetween such as a
substrate, thereby causing in-conveniences against the both. In
particular, the transfer of water occurs during the storage. In
order to prevent this, it is preferable that the packaging material
present therebetween at least has a moisture permeability of not
more than 2 g/m.sup.2/day in terms of a moisture permeability
according to the Lyssy method. By using this, in the case where the
heat generating body is accommodated in an outer bag as an
air-impermeable accommodating bag and stored, the transfer of water
can be prevented.
[0259] In the case where a hydrophilic adhesive layer is used as
the adhesive layer, the moisture permeability of a moisture-proof
packaging material provided between the heat generating composition
molded body and the hydrophilic adhesive layer is not limited so
far as the transfer of water can be prevented within the range
where the exothermic performance is not affected. The moisture
permeability according to the Lyssy method is usually not more than
2 g/m.sup.2/day, preferably not more than 1.0 g/m.sup.2/day, more
preferably not more than 0.5 g/m.sup.2/day, and further preferably
from 0.01 to 0.5 g/m.sup.2/day. These values are a value under a
condition under an atmospheric pressure at 40.degree. C. and 90%
RH. Incidentally, the moisture-proof packaging material can be used
as a substrate or a covering material and may be laminated singly
on a substrate, a covering material, or the like.
[0260] The moisture-proof packaging material is not limited so far
as the transfer of water between the heat generating composition
molded body and the hydrophilic adhesive layer can be prevented.
Examples thereof include metal vapor deposited films, vapor
deposited films of a metal oxide, metal foil-laminated films, EVOH
(ethylene/vinyl alcohol copolymer or ethylene/vinyl acetate
copolymer saponified product) based films, biaxially stretched
polyvinyl alcohol films, polyvinylidene chloride coated films,
polyvinylidene chloride coated films obtained by coating
polyvinylidene chloride on a substrate film (for example,
polypropylene), metal foils such as an aluminum foil,
air-impermeable packaging materials obtained by vapor depositing or
sputtering a metal (for example, aluminum) on a polyester film
substrate, and packaging laminates using a transparent barrier film
of a structure in which silicon oxide or aluminum oxide is provided
on a flexible plastic substrate. The air-impermeable packaging
materials which are used in the outer bag, etc. can also be
used.
[0261] Furthermore, packaging materials such as moisture-proof
packaging materials as described in JP-A-2002-200108, the
disclosures of which can be incorporated herein by reference, can
be used.
[0262] In the case of using a water-containing hydrophilic adhesive
(for example, a gel) in the adhesive layer, in order to adjust the
moisture equilibrium between the heat generating composition and
the adhesive layer, the content of a reaction accelerator (for
example, sodium chloride) or a substance having a water holding
power (for example, a water absorptive polymer) in the heat
generating composition may be adjusted within the range of from 10
to 40% by weight, preferably from 15 to 40% by weight, and more
preferably from 15 to 30% by weight based on the heat generating
composition.
[0263] Furthermore, as the adhesive having good moisture
permeability and low stimulation to the skin, water-containing
adhesives (for example, hydrophilic adhesives and gels) as
described in JP-A-10-265373 and JP-A-9-87173, adhesives which can
be subjected to hot melt coating as described in JP-A-6-145050 and
JP-A-6-199660, and rubber based adhesives as described
JP-A-10-279466 and JP-A-10-182408, the disclosures of which are
totally incorporated herein by reference, are useful.
[0264] The functional substance which is contained in the adhesive
layer is not limited so far as it is a substance having any
function. There can be enumerated at least one member selected from
aromatic compounds, vegetable extracts, crude drugs, perfumes,
slimming agents, analgesics, blood circulation promoters, swelling
improvers, antibacterial agents, sterilizers, mold inhibitors, odor
eaters, deodorants, percutaneously absorptive drugs, fat-splitting
components, minus ion generators, far infrared ray radiants,
magnetic bodies, fomentations, cosmetics, bamboo vinegar, and wood
vinegar.
[0265] Specific examples thereof include aromatic compounds (for
example, menthol and benzaldehyde), vegetable extracts (for
example, mugwort extract), crude drugs (for example, moxa),
perfumes (for example, lavender and rosemary), slimming agents (for
example, aminophylline and tea extract), analgesic drugs (for
example, indomethacin and dl-camphor), blood circulation promoters
(for example, acidic mucopolysaccharide and chamomile), swelling
improvers (for example, horse chestnut extract and flavone
derivatives), fomentations (for example, aqueous boric acid,
physiological saline, and aqueous alcohols), fat-splitting
components (for example, jujube extract, caffeine, and tonalin),
cosmetics (for example, aloe extracts, vitamin preparations,
hormone preparations, anti-histamines, and amino acids),
anti-bacterial agents and sterilizers (for example, carbolic acid
derivatives, boric acid, iodine preparations, invert soaps,
salicylic acid based substances, sulfur, and antibiotics), and mold
inhibitors.
[0266] The percutaneously absorptive drug is not particularly
limited so far as it has percutaneous absorption. Examples thereof
include corticosteroids, anti-inflammatory drugs, hypertension
drugs, anesthetics, hypnotic sedatives, tranquilizers,
antibacterial substances, antifungal substances, skin stimulants,
inflammation inhibitors, anti-epileptics, analgesics, antipyretics,
anesthetics, mold inhibitors, antimicrobial antibiotics, vitamins,
antiviral agents, swelling improvers, diuretics, antihypertensives,
coronary vasodilators, anti-tussive expectorants, slimming agents,
anti-histamines, antiarrhythmic agents, cardiotonics,
adrenocortical hormones, blood circulation promoters, local
anesthetics, fat-splitting components, and mixtures thereof.
However, it should not be construed that the invention is limited
thereto. These drugs are used singly or in admixture of two or more
kinds thereof as the need arises.
[0267] The content of the percutaneously absorptive drug is not
particularly limited so far as it falls within the range where the
effect of a medicine can be expected. However, from the viewpoints
of adhesive strength as well as pharmacological effect and economy,
the content of the functional substance is preferably from 0.01 to
25 parts by weight, and more preferably from 0.5 to 15 parts by
weight based on 100 parts by weight of the adhesive.
[0268] Furthermore, a method for providing the adhesive layer is
not limited so far as a thermal packaging body for joint
surroundings can be fixed. The adhesive layer may be entirely
provided or partially or intermittently provided. Examples of its
shape include various shapes such as a network-like shape, a
stripe-like shape, a dot-like shape, and strip-like shape.
[0269] The term "substantially planar" as referred to in the
invention means a planar surface not having an accommodating
concave such as an accommodating pocket, an accommodating section,
and an accommodating zone as provided in advance for the purpose of
accommodating the heat generating composition. Accordingly,
irregularities which do not intentionally accommodate the heat
generating composition may be present.
[0270] The "pocket" as referred to in the invention is an
accommodating pocket which is provided in advance for the purpose
of accommodating the heat generating composition and is a pocket as
described in JP-T-2001-507593. Since irregularities which are not
used for intentionally accommodating the heat generating
composition molded body are not the pocket, even when such
irregularities are present on a substrate, it is to be noted that
such a substrate is defined as a substantially planar
substrate.
[0271] The "accommodating section" as referred to herein is an
accommodating section for accommodation as provided in advance on
the packaging material for the purpose of accommodating the heat
generating composition and is an accommodating section as described
in Japanese Patent No. 3,161,605 and JP-T-11-508314. Since
irregularities which are not used for intentionally accommodating
the heat generating composition molded body are not the
accommodating section, even when such irregularities are present on
a substrate, it is to be noted that such a substrate is defined as
a substantially planar substrate.
[0272] The "accommodating zone" as referred to herein is an
accommodating zone for accommodation as provided in advance on the
packaging material for the purpose of accommodating the heat
generating composition and is an accommodating zone as described in
Japanese Patent No. 3,161,605 and JP-T-11-508314. Since
irregularities which are not used for intentionally accommodating
the heat generating composition molded body are not the
accommodating zone, even when such irregularities are present on a
substrate, it is to be noted that such a substrate is defined as a
substantially planar substrate.
[0273] Furthermore, so far as the reaction characteristics and
exothermic characteristics are not affected, the heat generating
composition having a water mobility value of less than 0.01 may
contain a flocculant aid, a flocculent, an agglomeration aid, a dry
binder, a dry binding agent, a dry binding material, a sticky raw
material, a thickener, an excipient, or a water-soluble polymer in
an amount ranging from 0.01 to 3 parts by weight.
[0274] The "flocculant aid" as referred to herein is a flocculant
aid as described in Japanese Patent No. 3161605 (JP-T-11-508314)
such as gelatin, natural gum, and corn syrup.
[0275] The "flocculant" as referred to herein is a flocculant as
described in JP-T-2002-514104 such as corn syrup and maltitol
syrup.
[0276] The "agglomeration aid" as referred to herein is an
agglomeration aid as described in JP-T-2001-507593 such as corn
syrup.
[0277] The "dry binder" as referred to herein is a dry binder as
described in JP-T-2002-514104 such as microcrystalline cellulose,
maltodextrin, and mixtures thereof.
[0278] The "dry binding agent" as referred to herein is a dry
binding agent as described in JP-T-2001-507593 such as maltodextrin
and sprayed lactose.
[0279] The "dry binding material" as referred to herein is a dry
binding material as described in JP-T-11-508314 such as
microcrystalline cellulose, maltodextrin, and mixtures thereof.
[0280] The "sticky raw material" or the "binder" as referred to
herein is a sticky raw material or binder as described in
JP-A-4-293989 such as water glass, polyvinyl alcohol (PVA), and
carboxymethyl cellulose (CMC).
[0281] The "thickener" as referred to herein is a thickener as
described in JP-A-6-343658 such as corn starch and potato
starch.
[0282] The "excipient" as referred to herein is an excipient as
described in JP-A-7-194641 such as .alpha.-starch and sodium
alginate.
[0283] As the "water-soluble polymer" as referred to herein, the
water-soluble polymer in the adhesive layer can be used.
[0284] The term "non-flexible" means that even when a bending test
of the subjective heat generating body as defined in JIS B2403 is
carried out, a crack or the like is not observed at all and that
when bent at 90.degree., the heat generating body is broken and
does not restore to the original shape, an aspect of which is
opposite to that of the term "flexible" which means that even when
bent at 90.degree., the heat generating body is not broken.
[0285] In the invention, as a heat seal material constituting a
heat seal layer, a single raw material may be used, or a composite
raw material having a heat seal layer may be used. The heat seal
material is not limited so far as at least a part thereof can be
welded upon heating. Examples thereof include hot melt based resins
such as polyolefins (for example, polyethylene and polypropylene)
or olefin copolymer resins, ethylene based hot melt resins (for
example, ethylene-vinyl acetate copolymer resins and
ethylene-acrylic acid ester copolymer resins (for example,
ethylene-isobutyl acrylate copolymer resins)), polyamide based hot
melt resins, butyral based hot melt resins, polyester based hot
melt resins, polyamide based hot melt resins, polyester based hot
melt resins, polymethyl methacrylate based hot melt resins,
polyvinyl ether based hot melt resins, polyurethane based hot melt
resins, polycarbonate based hot melt resins, such as polyvinyl
acetate, and vinyl chloride-vinyl acetate copolymers; and films or
sheets thereof. Furthermore, in these hot melt based resins or
films or sheets thereof, ones having various additives (for
example, an antioxidant) compounded therein can be used. In
particular, low density polyethylene and polyethylene obtained by
using a metallocene catalyst are useful.
[0286] In the case of interposing a heat generating composition
molded body between a substrate and a covering material, the
"temporary adhesion" as referred to in the invention means weak
pressure-sensitive bonding or adhesion for the purpose of holding
the accommodated heat generating composition molded body until at
least the substrate and the covering material are adhered to each
other via a sticky layer made of an adhesive and heat sealed.
[0287] Furthermore, the "deadhesion" as referred to herein means
that in the temporary adhering seal part after heat seal, the heat
generating composition in a non-heat sealed region is transferred
to the foregoing region, thereby releasing the temporary
adhesion.
[0288] The temporary adhering seal part is formed via a sticky
layer. An adhesive constituting the sticky layer is not limited so
far as it is a layer formed of a polymer composition which is tacky
at the normal temperature and can be heat sealed after the
temporary adhesion.
[0289] Furthermore, although the adhesive of the foregoing adhesive
layer can be used as the adhesive constituting the sticky layer to
be used for the temporary adhesion, a non-hydrophilic adhesive is
preferable. As the adhesive constituting the sticky layer, one
which is well compatible with the heat seal material constituting
the heat seal is preferable, and a melting point of a base polymer
of the adhesive is preferably not higher than a melting point of
the heat seal material. In particular, hot melt based adhesives are
preferable. Furthermore, in the case where the heat seal material
is made of an olefin based raw material, preferred examples of the
adhesive include olefin based adhesives.
[0290] Incidentally, a method for providing a sticky layer for the
temporary adhesion is not limited. The sticky layer may be entirely
provided or partially or intermittently provided. Examples of its
shape include various shapes such as a network-like shape, a
stripe-like shape, a dot-like shape, and strip-like shape.
[0291] A capacity of the sectional exothermic part or a volume of
the wettable heat generating composition compressed body is usually
from 0.015 to 500 cm.sup.3, preferably from 0.04 to 30 cm.sup.3,
more preferably from 0.1 to 30 cm.sup.3, further preferably from 1
to 30 cm.sup.3, and still further preferably from 3 to 20
cm.sup.3.
[0292] In the sectional exothermic part, when the sectional
exothermic part which is an accommodating region of the heat
generating composition is filled with the heat generating
composition molded body, a capacity ratio of the volume of the heat
generating composition molded body which is an occupying region of
the heat generating composition molded body to the capacity of the
sectional exothermic part which is an accommodating region of the
heat generating composition is usually from 0.6 to 1, preferably
from 0.7 to 1, more preferably from 0.8 to 1, and further
preferably from 0.9 to 1.0.
[0293] Furthermore, a width of the sectioned part which is a space
between the sectional exothermic parts is not limited so far as
sectioning can be achieved. It is usually from 0.1 to 50 mm,
preferably from 0.3 to 50 mm, more preferably from 0.3 to 50 mm,
further preferably from 0.3 to 40 mm, still further preferably from
0.5 to 30 mm, even further preferably from 1.0 to 20 mm, and even
still further preferably from 3 to 10 mm.
[0294] Furthermore, the "capacity of the sectional exothermic part"
as referred to herein means an internal capacity of the sectional
exothermic part having a heat generating composition molded body
accommodated therein.
[0295] Furthermore, a region where the air permeability is higher
than that in the covering part for covering the heat generating
composition molded body may be provided in a local region of the
air-permeable adjusting material, thereby keeping the air
permeability of other region lower than that on the air-permeable
surface of the sectional exothermic part. In this way, it is
possible to control an air passage for air, etc.
[0296] The fixing region between the air permeability adjusting
material and the exothermic part is not limited so far as the both
can be fixed and air can go in and out from at least the periphery
of the sectional exothermic part. However, the following can be
enumerated.
[0297] 1) The fixing region is fixed in the both ends of the
exothermic part or heat generating body.
[0298] 2) A space is provided entirely in a substantially central
part of the exothermic part, and other exothermic part region is
defined as the fixing region.
[0299] 3) A substantially top part of each sectional exothermic
part and a substantially central part of each sectioned part are
defined as the fixing region.
[0300] Here, as the air permeability adjusting material, any
material can be used so far as it is provided with a space which
communicates with the outside in the surroundings of the sectional
exothermic part. Examples of an air permeability adjusting material
having a bonding layer and utilizing a plastic film include
PE/adhesive, PP/adhesive, polyester/adhesive, PE/non-woven
fabric/air-permeable adhesive, PE/non-woven fabric/PE/adhesive,
PE/PET/M/PE/non-woven fabric/air-permeable adhesive, PE/heat seal
material, PE/non-woven fabric/heat seal material, PE/non-woven
fabric/PE/heat seal material, and PE/polyester/M/PE/non-woven
fabric/heat seal material. Here, M represents a metal (for example,
aluminum and silver), a semiconductor (for example, silicon oxide,
silicon oxynitride, silicon nitride, and aluminum oxide), or a
metal oxide, oxynitride or nitride. Furthermore, a portion for
placing fixing means such as an adhesive layer and a heat sealing
agent layer is not limited, and whether it is provided partially or
entirely may be properly determined depending upon the intended
purpose.
[0301] The bonding layer for fixing the air permeability adjusting
material is not limited so far as the air permeability adjusting
material can be fixed to the heat generating body and is
constituted of a usually used bonding agent or adhesive. In
particular, an adhesive is useful, and the adhesive constituting
the foregoing adhesive layer can be used.
[0302] Furthermore, a method for providing the bonding layer is not
limited so far as the air permeability adjusting material can be
fixed. The bonding layer may be entirely provided or partially or
intermittently provided. Examples of its shape include various
shapes such as a network-like shape, a stripe-like shape, a
dot-like shape, and strip-like shape. Its thickness is not
particularly limited but is in the range of from 5 to 1,000 .mu.m,
preferably from 10 to 500 .mu.m, and more preferably from 15 to 250
.mu.m. When the thickness of the bonding layer is less than 5
.mu.m, a desired adhesive strength may not be possibly obtained. On
the other hand, when it exceeds 1,000 .mu.m, not only it becomes
bulky and becomes worse in feeling for use, but also it becomes
worse in economy, and therefore, such is not preferable.
[0303] The heat generating body of the invention is able to give
various shapes, thicknesses and temperature zones and therefore,
can be used for various utilities such as use for a joint, facial
esthetic use, use for eyes, slimming use, use for heating or
warming a dripping solution, use for a wet compress pack, use for a
medical body warmer, use for a neck, use for a waist, use for a
mask, use for a glove, use for hemorrhage, use for relaxation of
symptoms such as shoulder pain, muscular pain, and menstrual pain,
use for a cushion, use for heating or warming a human body during
the operation, use for a thermal sheet, use for thermally
volatilizing an aroma, use for an abdomen, insecticidal use by
thermal volatilization, and use for treating cancer in addition to
common warming of a human body. In addition, the heat generating
body of the invention can be used for heating or warming machines,
pets, etc.
[0304] For example, in the case of using for relaxation of
symptoms, the heat generating body of the invention is applied
directly in a necessary site of the body or indirectly via a cloth,
etc. Furthermore, in the case of using for heating or warming a
human body during the operation, a method for using the heat
generating body of the invention includes the following
methods.
[0305] (1) The heat generating body is directly applied to a body
requiring heating or warming.
[0306] (2) The heat generating body is fixed on a covering, etc.
and covered on the body.
[0307] (3) The heat generating body is fixed on a cushion to be
placed beneath the body, etc.
[0308] (4) The heat generating body is used as a covering or a
cushion which is a product having the heat generating body provided
therein in advance.
[0309] Incidentally, examples of the pain of muscles or bones
include acute muscle pain, acute bone pain, acute reference pain,
previous muscle pain, previous bone pain, chronic reference pain,
and join pain of knee, elbow, etc.
[0310] The holding time is not limited but is preferably from 20
seconds to 24 hours, more preferably from one hour to 24 hours, and
further preferably from 8 hours to 24 hours.
[0311] The holding temperature is preferably from 30 to 50.degree.
C., more preferably from 32 to 50.degree. C., further preferably
from 32 to 43.degree. C., still further preferably from 32 to
41.degree. C., and even further preferably from 32 to 39.degree.
C.
[0312] The invention will be described below in detail with
reference to the following Examples.
BRIEF DESCRIPTION OF THE DRAWINGS
[0313] FIG. 1 is a graph showing exothermic characteristics of the
heat generating composition compressed bodies as prepared in
Example 1 and Comparative Examples 1 to 3.
[0314] FIG. 2 is a plan view of a filter paper for the measurement
of water mobility value in the invention.
[0315] FIG. 3 is an oblique view for explaining the measurement of
water mobility value in the invention.
[0316] FIG. 4 is a cross-sectional view for explaining the
measurement of water mobility value in the invention.
[0317] FIG. 5 is a cross-sectional view for explaining the
measurement of water mobility value in the invention.
[0318] FIG. 6 is a plan view of a filter paper after carrying out
the measurement of water mobility value in the invention.
DESCRIPTION OF REFERENCE NUMERALS AND SIGNS
[0319] 17: Pushing plate [0320] 18: Flat plate [0321] 19: Non-water
absorptive film (polyethylene film, etc.) [0322] 20: Filter paper
in which eight lines are drawn radiating from the central point
with an interval of 45.degree. [0323] 21: Die plate [0324] 22: Hole
[0325] 23: Sample [0326] 24: Stainless steel plate [0327] 25:
Distance to the oozed-out locus of water or aqueous solution [0328]
26: Position corresponding to a hollow cylindrical hole on filter
paper (circumferential part)
EXAMPLES
Example 1
[0329] A batchwise stirring tank consisting of a mixer equipped
with a rotary blade of a blade shape of ventilation fan was used as
an oxidizing gas contact treatment device, and air was used as an
oxidizing gas. A heat generating mixture consisting of 59.5 parts
by weight of an iron powder (particle size: not more than 300
.mu.m), 5.95 parts by weight of active carbon (particle size: not
more than 300 .mu.m), 3.5 parts by weight of a water absorptive
polymer (particle size: not more than 300 .mu.m), and 5 parts by
weight of 11% salt water and having a water mobility value of less
than 0.01 was charged in the oxidizing gas contact treatment
device. Next, in the state that the upper portion of the contact
treatment device vessel was opened to air, the reaction mixture was
subjected to self heat generation with stirring under circumstances
at 20.degree. C. After 30 seconds, at a point of time when a
temperature rise of the reaction mixture reached 10.degree. C., 11%
salt water was mixed in the reaction mixture to obtain a moldable
heat generating composition having a water mobility value of 8.
Next, a cavity-containing trimming die of 3 mm in
thickness.times.80 mm in width.times.110 mm in length was placed on
a substrate made of a 60 .mu.m-thick polyethylene film; the
moldable heat generating composition was filled in the cavity by
pushing molding; a pushing part-provided compression plate having a
height of 1 mm was then covered thereon such that the pushing part
was coincident with the cavity; and a pressure was applied, thereby
molding a wettable heat generating composition compressed body
having a thickness of 2 mm. The compression plate and the die were
removed to obtain a wettable heat generating composition compressed
body having a thickness of 2 mm as laminated on the substrate. The
wettable heat generating composition compressed body was
non-flexible.
Comparative Example 1
[0330] A heat generating composition having a water mobility value
of 8.0 was obtained by using the blending of Example 1 in the same
manner as in Example 1, except that the oxidizing gas contact
treatment was not carried out. By using this heat generating
compound, a heat generating composition compressed body was
obtained in the same manner as in Example 1.
Comparative Example 2
[0331] 0.1 parts by weight of glycerin or phosphorus was added to
the blending of Example 1 prior to the oxidizing gas contact
treatment, and 11% salt water was further added, followed by
stirring and mixing to obtain a heat generating composition having
a water mobility value of 8.0. This heat generating composition was
charged in a cavity-containing trimming die of 3 mm in
thickness.times.80 mm in width.times.110 mm in length, a pushing
part-provided compression plate having a height of 3 mm was then
covered thereon such that the pushing part was coincident with the
cavity, and a pressure of 7,540 kg/cm.sup.2 was applied for 10
seconds, thereby preparing a heat generating composition compressed
body.
Comparative Example 3
[0332] A heat generating composition compressed body was obtained
in the same manner as in Example 1 by using a heat generating
composition of the blending of Comparative Example 2, except for
using CMC in place of the glycerin.
[0333] A sensor was installed on the substrate surface beneath the
substrate in the substantially central part of each of the heat
generating composition compressed bodies as prepared in Example 1
and Comparative Examples 1 to 3, and an exothermic rising test of
heat generating compressed body was carried out. The measurement
results are shown in FIG. 1. As shown in FIG. 1, in the case of
Example 1, the temperature reached 50.degree. C. after 3 minutes
and 73.degree. C. after 10 minutes, respectively. In the case of
Comparative Example 1, the temperature reached 41.degree. C. after
3 minutes and 45.degree. C. after 10 minutes, respectively. In the
case of Comparative Example 2, the temperature reached 38.degree.
C. after 3 minutes and 43.degree. C. after 10 minutes,
respectively. In the case of Comparative Example 3, the temperature
reached 40.degree. C. after 3 minutes and 45.degree. C. after 10
minutes, respectively. In the light of the above, it was noted that
the heat generating body of Example 1 has much more excellent
characteristics in view of the practical use.
Example 2
[0334] A batchwise stirring tank consisting of a mixer equipped
with a rotary blade of a blade shape of ventilation fan was used as
an oxidizing gas contact treatment device, and air was used as an
oxidizing gas. A heat generating mixture consisting of 100 parts by
weight of an iron powder (particle size: not more than 300 .mu.m),
5.0 parts by weight of active carbon (particle size: not more than
300 .mu.m), 3.5 parts by weight of a water absorptive polymer
(particle size: not more than 300 .mu.m), 2.0 parts by weight of a
wood meal, and 5 parts by weight of 11% salt water and having a
water mobility value of less than 0.01 was charged in the contact
treatment device vessel. Next, in the state that the upper portion
of the contact treatment device vessel was opened to air, the heat
generating mixture was subjected to self heat generation with
stirring under circumstances at 30.degree. C. and contact treated
with an oxidizing gas at a maximum exothermic temperature of
67.degree. C. until the exothermic temperature reached 35.degree.
C., thereby obtaining an oxidizing gas contact treated heat
generating mixture. 11% salt water was mixed in this heat
generating mixture to obtain a moldable heat generating composition
having a water mobility value of 8. A cavity-containing trimming
die of 3 mm in thickness.times.80 mm in width.times.110 mm in
length was placed on a substrate made of a 60 .mu.m-thick
separator-provided polyethylene film provided with an acrylic
adhesive layer; the moldable heat generating composition was filled
in the cavity by pushing molding; a pushing part-provided
compression plate having a height of 1 mm was then covered thereon
such that the pushing part was coincident with the cavity; and a
pressure was applied, thereby molding a wettable heat generating
composition compressed body having a thickness of 2 mm. The
compression plate and the die were removed to obtain a wettable
heat generating composition compressed body having a thickness of 2
mm as laminated on the substrate. This wettable heat generating
composition compressed body was non-flexible. A covering material
made of a non-woven fabric-provided polyethylene-made porous film
was covered thereon, the periphery of the wettable heat generating
composition compressed body was heat sealed, and the outer
circumferential part was cut while retaining a seal width of 8 mm,
thereby obtaining a heat generating body. Next, the heat generating
body was sealed in an outer bag which is an air-impermeable
accommodating bag. Incidentally, the air permeability of the
covering material was 600 g/m.sup.2/24 hr in terms of a moisture
permeability by the Lyssy method. After 24 hours, the heat
generating body was taken out from the outer bag and subjected to
an exothermic test by the body. As a result, it was felt warm after
3 minutes, and thereafter, the warmth was continued for 10 hours or
more.
Example 3
[0335] A batchwise stirring tank consisting of a mixer equipped
with a rotary blade of a blade shape of ventilation fan was used as
an oxidizing gas contact treatment device, and air was used as an
oxidizing gas. A heat generating mixture consisting of 100 parts by
weight of a reduced iron powder (particle size: not more than 300
.mu.m), 25 parts by weight of active carbon (particle size: not
more than 300 .mu.m), 3 parts by weight of a water absorptive
polymer (particle size: not more than 300 .mu.m), 0.5 parts by
weight of calcium hydroxide, 0.7 parts by weight of sodium sulfite,
and 5 parts by weight of 11% salt water and having a water mobility
value of less than 0.01 was charged in the contact treatment device
vessel. Next, in the state that the upper portion of the contact
treatment device vessel was opened to air, the heat generating
mixture was subjected to self heat generation with stirring under
circumstances at 30.degree. C. and contact treated with an
oxidizing gas at a maximum exothermic temperature of 67.degree. C.
until the exothermic temperature reached 35.degree. C., thereby
obtaining an oxidizing gas contact treated heat generating mixture.
11% salt water was mixed in the oxidizing gas contact treated heat
generating mixture to obtain a moldable heat generating composition
having a water mobility value of 7. Next, a substrate made of a
laminate of a polyethylene film and a polypropylene-made non-woven
fabric was placed on a stainless steel plate such that the side of
the non-woven fabric was brought into contact with the stainless
steel plate; a trimming die having a cavity of 10 mm in
diameter.times.3 mm in height was subsequently placed on the side
of the polyethylene film of the substrate; the moldable active heat
generating composition was further placed on the trimming die; and
the moldable active heat generating composition was filled into the
cavity while leveling by using a leveling plate. Next, a
compression plate having a convex having a height of 1 mm and
capable of closely coming in the cavity in the central part thereof
was placed such that the convex came in the cavity. The moldable
active heat generating composition which had come in the cavity of
die interposed between the stainless steel plate and the
compression plate was compressed by passing through rolls, and the
die was then removed to obtain a heat generating composition
compressed body of 2 mm in thickness.times.10 mm in diameter. Next,
an air-permeable covering material made of a laminate of a
polyethylene-made porous film and a nylon-made non-woven fabric was
covered on the heat generating composition compressed body such
that the side of the porous film was brought into contact with the
heat generating composition compressed body, and the periphery of
the heat generating composition compressed body was then heat
sealed in a seal width of 8 mm, thereby obtaining a heat generating
body having a diameter of 28 mm in terms of an outer dimension.
This heat generating body was sealed and accommodated in an outer
bag and allowed to stand at room temperature for 24 hours.
Incidentally, the air permeability of the air-permeable covering
material 6 was 400 g/m.sup.2/24 hr in terms of a moisture
permeability by the Lyssy method. Collapsed pieces of the heat
generating composition molded body were not generated in the
surroundings of the heat generating composition molded body, heat
sealing could be surely achieved, and cutting in seal was not
generated. After 24 hours, the heat generating body was taken out
from the outer bag and subjected to an exothermic test. As a
result, the temperature reached 55.degree. C. within 3 minutes.
Example 4
[0336] By using the substrate and the covering material of Example
2, the heat generating composition compressed bodies of 2 mm in
thickness.times.10 mm in diameter of Example 4 were arranged fives
in the length and three in the width, respectively at intervals of
5 mm; the periphery of each of the heat generating composition
compressed bodies was heat sealed in the same manner as in Example
1; and the outer circumference of the heat generating body was
further heat sealed, thereby obtaining a substantially rectangular
heat generating body in which a 4-mm portion between the heat
generating composition compressed bodies and an 8-mm portion of the
outer circumference of the heat generating body were heat sealed.
This heat generating body was sealed and accommodated in an outer
bag and allowed to stand at room temperature for 24 hours.
Incidentally, the air permeability of the air-permeable covering
material 6 was 400 g/m.sup.2/24 hr in terms of a moisture
permeability by the Lyssy method. Collapsed pieces of the heat
generating composition molded body were not generated in the
surroundings of the heat generating composition molded body, heat
sealing could be surely achieved, and cutting in seal was not
generated. After 24 hours, the heat generating body was taken out
from the outer bag, stuck to the outside of underwear and subjected
to an exothermic test by the body to which the heat generating body
had been stuck on the abdominal region. As a result, it was felt
warm after 3 minutes, and the proper temperature was continued for
8 hours or more. The heat generating body was convenient in
handling and well followed and adapted with the curved face of the
abdominal region.
Example 5
[0337] By using the moldable heat generating composition of Example
3, a wettable heat generating composition compressed body of 2 mm
in thickness.times.10 mm in diameter was obtained in the same
manner as in Example 3. The wettable heat generating composition
compressed body was charged in an accommodating section made of a
sheet of an EVA layer and a polypropylene layer and vacuum molded
in a disc shape; a sheet made of an EVA layer and a polypropylene
layer was further covered thereon such that the EVA layers were
superimposed each other; and these two sheets were heat sealed to
seal the wettable heat generating composition compressed body in an
accommodating section between these sheets, thereby forming a
pocket heat generating body. Next, an LDPE film was perforated, and
the pocket heat generating body was sealed in an outer bag which is
an air-impermeable accommodating body. After 24 hours, the pocket
heat generating body was taken out from the outer bag and allowed
to stand in air. As a result, the pocket heat generating body soon
started to generate heat. The polypropylene non-woven fabric/LDPE
sheet was perforated, and an oxygen-diffusible permeability of
about 1.7 cc/min/5 cm.sup.2 (at 21.degree. C. and one atmosphere)
was imparted. Furthermore, the pocket heat generating body had a
height of about 2.1 mm and a diameter of about 11 mm, and a ratio
of the volume of the exothermic part to the volume of the wettable
heat generating composition compressed body was about 0.81. If a
plural number of this pocket heat generating body is fixed on a
non-woven fabric by an adhesive or the like and a fixing measure
such as an adhesive layer is provided, the pocket heat generating
body can be used for body wearing implements and the like likewise
the heat generating body of Example 5.
* * * * *