TECHNICAL FIELD
-
The present invention relates to a novel fireproof
container, more particularly, a fireproof container having a
satisfactory fire resistivity that inhibits quality
deterioration of articles to be stored (designated as "storing
articles", hereinafter) even when exposed to a relatively high
temperature condition.
BACKGROUND ART
-
In fireproof containers such as conventional fire-resistant
containers, the heat capacity (multiplication of
specific heat and mass) of walls of the fireproof containers is
gained by using, as materials for the walls, a quantity of
materials with a relatively large mass and specific heat such
as concrete. Because of this, the gross weight of the fireproof
containers becomes too high. Independently of business and
household uses and if only the desired fireproof ability will
be attainable, such an increased gross weight tends to be rather
acceptable for fireproof containers, which are to be used for
storing valuable articles such as money, valuable metals, and
securities, in view of antitheft. Therefore, the weight saving
of fireproof containers has not been focussed on so much until
now.
-
However, even a fireproof container with an
outstandingly high fire resistivity would never secure the
stable keeping of storing articles when the container is
encountered with fire having no promising time for fire
extinction such as fire of tower blocks and other fires
accompanied by earthquakes and volcanic eruptions. To deal with
such disasters, the only way is to bring out fireproof
containers from places at fire as quick as possible, however,
conventional types of extensively heavily fireproof containers
are substantially impossible to be brought out quickly,
depending on disaster conditions. Such a problem will be
overcome by the establishment of a fireproof container with
properties of sufficient fire resistivity and advantageous
transportability.
-
In these days with an increased concerning on articles
having property values such as art objects, there has been an
increased demand for safe storing of such articles which are
possessed privately or publicly. Accordingly, the present
inventors studied on the effectiveness of fire resistivity of
fireproof containers in general now used widely for use in
storing such articles. As a result, they found that the fire
resistivity of conventional fireproof containers such as those
"for papers in general use" specified in JIS S 1037:1998, Fire-resistive
container(s) (designated as "JIS Fire-resistive
container(s), hereinafter), in Japanese Industrial Standards,
revised on March 20, 1998, published by Japanese Standards
Association, can hold storing articles to an extent that it
allows the articles to be recognized as what they are even after
having been exposed to relatively high-temperature conditions
but is not necessarily sufficient for use in storing art objects
and the like which should be avoided from quality deterioration.
Based on these, the present inventors concluded that there is
a great potential need for fireproof containers having both
advantageous fire resistivity of inhibiting quality
deterioration of storing articles and transportability
applicable to the above situations in fire and the like.
-
In addition, though it is not so many, there are some
proposals for fireproof containers with an improved
transportability. For example, a lightweight portable fireproof
container as disclosed in Registered Japanese Utility Model No.
3,033,602, and a fireproof container disclosed in Japanese
Patent Kokai No. 61,323/98 can be mentioned. As evident from
a disclosure in the item of "Effect of the Present Utility
Model" in the former specification, i.e., "The fireproof
container of the present utility model has enabled to completely
protect articles in a fireproof container from fire with only
allowing the container to place in a conventional, widely-used,
relatively low cost fireproof container.", the former fireproof
container has an advantageous transportability but is hard to
say that it exerts a sufficient fire resistivity when used
alone. While, as evident from a disclosure in the item of
"Object of the Invention" of the latter specification, i.e., "By
imparting an advantageous fire resistivity and lowering the
weight as much as possible, a fireproof container with an
improved handleability is provided.", the characteristic feature
of the above proposal resides in the attainment of weight saving
of the container but not distinctive improvement of its fire
resistivity. Also, these proposals could not be said to have
sufficient actual utility. As described above, the fact is
that, in spite of the potential demand, there has not yet been
established any fireproof container possessing both advantageous
fire resistivity of preventing the quality deterioration of
storing articles and the desired transportability applicable to
the aforesaid situations in fire and the like.
DISCLOSURE OF INVENTION
-
In view of the foregoing background, the object of the
present invention provides a fireproof container possessing both
fire resistivity of preventing the quality deterioration of
storing articles and advantageous transportability.
-
First, the present inventors confirmed in a
preliminarily experiment that, as described above, the ability
of acceptable inner temperature of 177°C or lower, which is of
the fire-resistive container "for papers in general use"
specified in JIS Fire-resistive container(s), is thoroughly
insufficient for storing art products and the like, whose
quality deterioration should be avoided, to meet the fire
resistivity aimed at by the present invention. Then, the
present inventors energetically studied to establish a fireproof
container which far exceeds the above fire resistivity of
conventional fireproof containers and has advantageous
transportability.
-
However, as far as the present inventors' tests with
various combinations of materials generally used in conventional
fireproof containers, no sufficiently acceptable fireproof
container was obtained. Accordingly, the present inventors had
changed their conception, then focused on materials other than
those used in conventional fireproof containers and further
continued studying. As a result, they found that the aimed
fireproof container that sufficiently overcomes the object of
the present invention is obtained by forming a fireproof
container with a multilayer structure of three outer-, middle-
and inner-layers positioning in this order from the outside to
the inside of the container; wherein in the multilayer structure
a layer, as the outer layer, comprising a fire-resistant
insulating material having a bulk specific gravity of not higher
than 1.0 g/cm3, which has not been used as a partial structure
of fireproof containers, is employed in combination with another
layer, as the middle layer, comprising a material having an air-spaced
layer and/or endothermic property and the other layer,
as the inner layer, comprising an incombustibility material
having a bulk specific gravity of not higher than 2.0 g/cm3.
The present invention was made based on this complete self-finding
by the present inventors.
-
Thus, the present invention solves the object of the
present invention by providing a fireproof container comprising
a container portion having partially an opening part and a lid
means capable of sealing the opening part to keep the inner
space of the container portion in a sealed condition and
optionally capable of making the inner space into an open
condition, where the container portion comprises a multilayer
structure of three outer-, middle- and inner-layers positioning
in this order from the outside to the inside of the container,
the outer layer comprises a fire-resistant insulating material
having a bulk specific gravity of not higher than 1.0 g/cm3, the
middle layer comprises a material having an air-spaced layer
and/or endothermic property, and the inner layer comprises an
incombustibility material having a bulk specific gravity of not
higher than 2.0 g/cm3.
BRIEF DESCRIPTION OF DRAWINGS
-
- FIG. 1 is a drawing of endothermic property of hydrous
crystalline trehalose.
- FIG. 2 is a standard temperature curve for the
standard heat test specified in JIS Fire-resistive container(s).
- FIG. 3 is a typical drawing of longitudinal sectional
view of an embodiment of the fireproof container of the present
invention, i.e., the fireproof container A in Example 1.
- FIG. 4 is a typical drawing of longitudinal sectional
view of another embodiment of the fireproof container of the
present invention, i.e., the fireproof container B in Example
1.
- FIG. 5 is a typical drawing of longitudinal sectional
view of the other embodiment of the fireproof container of the
present invention, i.e., the fireproof container C in Example
1.
- FIG. 6 is a drawing of the changes of inner
temperatures of the fireproof containers A, B and C of the
present invention and of containers X1 and X2 as controls when
subjected to the 1-hour standard heat test.
- FIG. 7 is a typical drawing of longitudinal sectional
view of another embodiment of the fireproof container of the
present invention in Example 2.
- FIG. 8 is a typical drawing of longitudinal sectional
view of another embodiment of the fireproof container of the
present invention in Example 3.
- FIG. 9 is a typical drawing of longitudinal sectional
view of another embodiment of the fireproof container of the
present invention in Example 4.
- FIG. 10 is a typical drawing of longitudinal sectional
view of another embodiment of the fireproof container of the
present invention in Example 5.
- FIG. 11 is a typical perspective view of outlook of
the fireproof container in Example 5 when the container portion
and the lid means of the fireproof container exist
independently.
-
Explanation of symbols
-
- 1
- Container portion
- 1a
- Outer layer
- 1b
- Inner layer
- 1c
- Middle layer
- 1d
- Spacer
- 1e
- Agent for inhibiting the increase of temperature
- 1f
- Moistureproof layer
- 1g, 1h
- Outermost layer
- 2
- Lid means
- 2a
- Layer of lid means corresponding to outer
layer in container portion
- 2b
- Layer of lid means corresponding to inner
layer in container portion
- 2c
- Layer of lid means corresponding to middle
layer in container portion
- 2d
- Spacer in lid means corresponding to spacer in
container portion
- 2f
- Layer of lid means corresponding to moistureproof
layer in container portion
- 2g, 2h
- Layer of lid means corresponding to outermost
layer in container portion
- 3
- Storing article
BEST MODE OF THE INVENTION
-
As shown in FIG. 4 for a typical drawing of
longitudinal sectional view of an embodiment of the fireproof
container of the present invention, the fireproof container is
characterized in that it comprises a container portion 1 having
partially an opening part and a lid means 2 capable of sealing
the opening part to keep its inner space in a sealed condition,
and optionally capable of making the inner space into an open
condition, where the container portion 1 comprises a multilayer
structure of at least three layers of an outer layer 1a, middle
layer 1c, and inner layer 1b positioning in this order from the
outside to the inside of the container, wherein in the
multilayer structure the outer layer 1a comprises a fire-resistant
insulating material having a bulk specific gravity of
not higher than 1.0 g/cm3, the middle layer 1c comprises a
material having an air-spaced layer and/or endothermic property,
and the inner layer 1b comprises an incombustibility material
having a bulk specific gravity of not higher than 2.0 g/cm3. In
the embodiment of FIG. 4, the lid means 2 comprises each
independent materials of an outer lid means constructed by a
layer 2a corresponding to the outer layer 1a in the container
portion 1. When used by sealing the opening part of the
container portion 1 with the independent materials, a space
between the layers 2a and 2b forms a layer 2c corresponding to
the middle layer 1c in the container portion 1. Also, in FIG.
4, the symbol 3 shows a storing article.
-
As long as the outer layer in the multilayer structure
for forming the container portion of the fireproof container is
a layer comprising a fire resistant material and having a bulk
specific gravity of not higher than 1.0 g/cm3, preferably, not
higher than 0.5 g/cm3, and more preferably, not higher than 0.4
g/cm3, and being capable of exerting the effect to solve the
object of the present invention, any layers either consisting
of single material or comprising different materials can be used
without specific restriction of their properties and chemical
compositions of the materials used. Although the minimum bulk
specific gravity of the outer layer is not specifically
restricted from a viewpoint of transportability of the fireproof
container, it is preferably be set to a level, usually, at least
0.2 g/cm3, preferably, at least 0.25 g/cm3, from a viewpoint of
keeping the physical strength of the fireproof container.
Regarding the thermal property as another preferable property
of the outer layer, it can be exemplified, for example, a
thermal property that does not substantially lose the inherent
mechanical strength of the outer layer when and/or after exposed
to temperature conditions of, usually, up to 1,000°C,
preferably, up to 1,200°C; while regarding the heat insulating
property, it can be exemplified a heat insulating property that
usually shows a coefficient of thermal conductivity of 0.15
W/(m·k) or lower, preferably, 0.12 W/(m·k) or lower at 600°C.
When the outer layer has an adequate flexibility of absorbing
external shock, it may be advantageous in installing an
outermost layer on the outside of the outer layer as described
later. As an example of the fire resistive insulating materials
usable in the present invention, ceramic fibers, aluminum
fibers, and ceramics such as lightweight ceramic products
disclosed in Japanese Patent Kokai No. 109,381/00, can be
mentioned; these materials can be used in practicing the present
invention in such a manner of allowing them to form over the
above layers having the above properties. In addition,
"ISOWOOL® 1260 BOARD", a commercialized ceramic fiber board,
produced by Isolite Insulating Products Co., Ltd., Tokyo, Japan,
and the like can be advantageously used in practicing the
present invention because they have been formed into layers or
plates having the aforesaid properties. The thickness of the
outer layer is appropriately chosen depending on the structure
of other layers used in combination, the types and kinds of
storing articles to be placed, and the fields of the fireproof
containers to be used. For example, in the case of using
fireproof containers having an outer layer of the aforesaid
commercialized products as containers for business or household
use, the thickness of the outer layer is usually at least 10 mm,
preferably, 20-400 mm, and more preferably, 50-200 mm.
-
Regarding the inner layer in the multilayer structure
for forming the container portion of the fireproof container of
the present invention, any layers can be used in the present
invention without restricting to specific property and chemical
composition of the materials used as long as the layers have
usually a bulk specific gravity of 2.0 g/cm3 or lower,
preferably, 0.15-1.5 g/cm3, and more preferably, 0.8-1.2 g/cm3,
and exert the effect of solving the object of the present
invention. Such layers may be those made of a single substance
or a composition of substances. Regarding the incombustibility
of the inner layer, those which do not substantially ignite or
catch fire under temperature conditions, usually, of 800°C or
lower, preferably, 1,000°C or lower, can be preferable. The
inner layer usable in the present invention is preferably those
which attain a desired heat capacity within a limitation that
does not affect the transportability. In addition to the above
bulk specific gravity, the suitable property for keeping the
desired heat capacity is an adequate thermal conductivity,
usually, of 0.6 W/(m·k) or lower, preferably, 0.4 W/(m·k) or
lower at 350°C. As an example of the materials for
incombustibility usable in the present invention, it can be
mentioned, for example, insulating firebricks that fulfill the
standard C-1 specified in "Insulating Firebrick", JIS R
2611:1992, in Japanese Industrial Standards, revised on May 1,
1992. Such insulating firebricks can be used after processed
into the desired shapes depending on needs. For example,
"ISOLITE C-1", a product of Isolite Insulating Products Co.,
Ltd., Tokyo, Japan, can be arbitrarily used as a commercialized
product,that fulfills the above standard. The thickness of the
inner layer is appropriately set depending on the structure of
other layers used in combination, the kind/type of storing
articles to be placed, and the field of the fireproof containers
to be used, etc. For example, in the case of the fireproof
containers comprising inner layers of the above commercialized
products used as containers for business or household use, the
thickness of the inner layer is, usually, at least 1 mm,
preferably, 2-40 mm, more preferably, 5-20 mm.
-
The multilayer structure which forms the container
portion of the fireproof container of the present invention
further comprises a middle layer positioning between the above
outer- and inner-layers. The middle layer is a layer which
comprises a material having an air layer and/or the desired
endothermic property. When such an air layer is provided as the
middle layer, an appropriate spacer(s) is placed between the
outer- and inner-layers in conventional manner. The
installation of the air layer as the middle layer is
particularly advantageous to improve the transportability of the
fireproof container.
-
While in the case of installing as the middle player
a layer comprising a material with the desired endothermic
property, the fire resistivity of the fireproof container is
more improved. Any materials can be used as the above material
as long as they exert the effect of solving the object of the
present invention when formed into the middle layer of the
fireproof container without restriction of their property and
chemical composition and independently of being made of a simple
substance or a composition of substances. The materials with
the desired endothermic property usable in the present invention
include, for example, organic- or inorganic-materials having an
endothermic property of generating an endothermic reaction at
temperatures, usually, of about 80 to about 200°C, preferably,
about 90 to about 150°C without being influenced by humidity.
Examples of the organic materials usable in the present
invention include, particularly, sodium thiosulfate, disodium
hydrogenphosphate, and sodium sulfate. The organic materials
usable in the present invention include, particularly, mono- and
oligo-saccharides such as glucose, maltose, lactose, trehalose
(α,α-trehalose which may be abbreviated as "trehalose"
hereinafter, if specified otherwise), neotrehalose (α,β-trehalose),
raffinose, rhamnose, and lactulose; sugar alcohols
such as erythritol, xylitol, sorbitol, maltitol, and lactitol;
cyclodextrins such as α-, β-, γ-cyclodextrins, and glycosyl
derivatives thereof; and other saccharides such as
cyclotetrasaccharide and glycosyl derivatives thereof, where the
cyclotetrasaccharide is disclosed as "cyclic tetrasaccharide"
along with its detailed crystalline structure by G. M. Bradbrook
in Carbohydrate Research, Vol. 329, pp. 655-665 (2000). Among
these materials, those which can exist in the form of a hydrous
crystal or hydrate are particularly useful in practicing the
present invention because they have also a property of exerting
an endothermic property and inhibiting the internal drying of
the container portion by releasing their bound water. In
addition to the above endothermic property, since more
preferably used are materials having a lesser danger of
generating poisonous gasses when heated, the aforesaid
saccharides with the desired endothermic property can be
particularly advantageously used in the present invention
because they have a relatively lesser fear of generating
poisonous gasses. One of the particularly preferable materials,
which can be mentioned in view of the above aspect, is a hydrous
crystalline trehalose, for example, a commercially available
saccharide, "TREHA®", a product commercialized by Hayashibara
Shoji Inc., Okayama, Japan. Regarding this, FIG. 1 shows a
result of the endothermic property, i.e., the endothermic value
per hour and per weight, of a hydrous crystalline trehalose
using the above commercialized product, measured on a
differential scanning calorimeter under an increasing
temperature condition of 10°C/min within a temperature range of
50 to 170°C. The result shows that hydrous crystalline
trehalose has an advantageous endothermic property in practicing
the present invention. To form the middle layer using the
aforesaid materials, for example, one or more materials,
selected appropriately depending on purposes, would have been
previously formed into multilayer products using appropriate
binders or injected into the space provided between the above
outer- and inner-layers. The thickness of the middle layer is
appropriately set in view of the structure of other layers used
in combination, the kind/type of storing articles to be placed,
and the fields of the fireproof containers to be used. For
example, in the case of the fireproof containers used as
containers for business or household use, the thickness of their
middle layer is usually set to at least 1 mm, preferably, 2 to
40 mm, and more preferably, 5 to 20 mm. Also, in the fireproof
container of the present invention, either of the following
structures can be employed; a structure, as the middle layer,
constructed by two layers of the above-mentioned air layer and
another layer comprising a material(s) having the desired
endothermic property, where the layers are closely adjacent each
other, or the structure comprising partially a material(s)
having the desired endothermic property, for example, the
structure of a layer comprising such a material(s) imparted with
appropriate voids.
-
Although the multilayer structure for forming the
container portion of the fireproof container of the present
invention has basically the above structure, an outermost layer
can be optionally provided on the outside of the above outer
layer of the fireproof container of the present invention. For
example, when an outermost layer made of a metal or ceramic is
provided, the outer layer of the fireproof container can be
avoided from a direct flame when in fire and the like, resulting
in a more effective prevention of increasing the inner
temperature as a merit. Such an outermost layer also exerts a
function of protecting the inner structure from external shocks.
In the case of providing a metallic or ceramic layer as the
outermost layer, when the fireproof container is subjected to
temperature changing conditions, a force is actuated on its
internal layer, for example, the outer layer of the above
container portion by the difference of expansion coefficients
of the metallic layer and the inner structure, and this may
result in deforming the inner layer or inducing cracks and then
affecting the inhibition of inner temperature increase. Such
a problem would be overcome by using a thinnest possible layer
as the outermost layer and making the thinnest layer into a
structure which contacts, but not completely, with the surface
of the inner layer. Alternatively, such a problem can be
overcome by providing either an insulating layer with
flexibility and fire resistivity on the surface of the inner
layer adjacent to the outermost layer or making the inner layer
adjacent to the outermost layer into a layer formed with a
material with adequate flexibility. The thickness of the
outermost layer is appropriately selected depending on the
type/kind of the materials used: For example, when materials
with relatively high thermal tolerance having, usually, heat
tolerance up to a temperature of 1,000°C are used in a ceramic
layer, the resulting ceramic layer should have a thickness of
about 1 to 20 mm, preferably, 5 to 10 mm; when copper or
aluminum is used as a material for a metal layer, the resulting
layer should have a thickness of about 2 mm or lower; and when
iron or stainless steel is used as a material for a metal layer,
the resulting layer should have a thickness of about 0.5 mm or
lower. With these conditions, there exert advantageous features
of improving the fire resistivity and shock tolerance and
effectively avoiding the above problems. In the case of not
installing the outermost layer or of providing, as the outermost
layer, layers made of sheets with moisture permeability such as
papers, cloths, and woods, the resulting fireproof container has
a characteristic feature that the inner moisture level in the
container portion can be controlled by changing the external
circumstances under ambient temperature condition. By
providing, as the outermost layer, layers made of materials such
as papers, cloths and woods which can be appropriately colored,
the fireproof container can be easily modified with the desired
colors or paintings.
-
In addition to the above multilayer structure, a
moistureproof layer is advantageously provided between the
outer- and middle-layers, if necessary. For example, the
fireproof container would be watered during fire fighting when
in fire, and therefore, when the middle layer of the fireproof
container is made of an organic- or inorganic-material, such a
material dissolves in water when watered and then flows out of
the middle layer, and this would possibly affect the function
of the fireproof container or hinder the recycling thereof.
Such a problem can be avoided by installing the above-mentioned
moistureproof layer. The materials and functions of the
moistureproof layer have no restriction as long as they do not
hinder the function of the fireproof container of the present
invention; in this regard, aluminum foil-laminated sheets and
the like can be advantageously used.
-
If necessary, in the fireproof container of the
present invention, another layer(s) which does or does not
fulfil the requirement of either of these layers can be
optionally installed in a part or the whole of one or more
rooms/spaces formed between any of two layers of the above
outermost-, outer-, moistureproof-, middle-, and inner-layers;
and a space of the inside of the inner layer. By employing such
a structure, a more improved fire resistivity can be attained,
although it somewhat deteriorates the transportability of the
fireproof container. For example, the fireproof resistivity of
the fireproof container can be more improved by installing
layers of calcium silicate or foam concrete as a relatively
advantageous incombustible material into an appropriate space,
usually, either of internal rooms/spaces formed between layers
in the inside of the outer layer, preferably, in the inside of
and adjacent to the outer layer. Depending on the shape as
described later, the fireproof container may occasionally have
a high-temperature local site when exposed to heating
conditions, and therefore, the fire resistivity in such a local
site to be assumed can be advantageously reinforced by providing
partially the aforesaid another layer(s). Actually, depending
on conditions, the corner portions of the middle- and inner-layers
of the fireproof container may give a higher temperature
than the other middle- and inner-layers, however, such a problem
can be avoided by installing the aforesaid another layer in the
portions corresponding to the corner portions or preferably
installing an outermost layer made of a material with fire
resistivity.
-
The container portion of the fireproof container of
the present invention is formed by the multilayer structure
described above. As long as the container portion is formed by
the above multilayer structure when made into a sealed condition
internally by combining with a lid means having partially an
opening part and being capable of sealing the opening part, any
procedure for forming the container portion and any structure
thereof in a separate condition from the lid means can be used.
For example, the container portion is formed by providing
previously a structure with the desired shape in the form of a
plain plate having the aimed multilayer structure, and
constructing the structure as a material part into the desired
shape in the form of a box and the like having partially an
opening part. Alternatively, the container portion can be
formed by providing previously a structure with the desired
shape in the form of a box having partially an opening part, and
sequentially layering onto the structure other layers of middle-
and inner-layers. Furthermore, in the case of employing a
structure prepared by making a lid means 2, as shown in FIGs.
10 and 11 as the whole structure of the fireproof container,
into a box shape having partially an opening part, and then
inserting a container portion 1 into the lid means 2 to make the
internal part of the container portion into a sealed condition,
the container portion 1 existing separately from the lid means
2 should not necessary have all of the three outer-, middle- and
inner-layers in a part corresponding to the part of the lid
means having the desired layers, if only the desired layers
corresponding to the outer-, middle- and inner-layers in the
container portion are provided in the lid means 2. The shape
of the container portion should not be restricted to a specific
one and, in view of the type/kind of storing articles to be
applied and the total design, it can be appropriately selected
from columnar, conical, square, pyramidal, and spherical shapes,
as well as a box shape. The position of the opening part in the
container portion is appropriately selected from the top-, side-
and bottom-faces depending on use.
-
The lid means of the fireproof container of the
present invention is a structure capable of sealing the opening
part of the container portion as mentioned above to keep the
internal part in a sealed condition, and of making the internal
part into an open condition depending on need. Although the lid
means should preferably has the same multilayer structure as in
the above-mentioned container portion, the multilayer structure
can be partially omitted or modified within the limitation of
not losing the effect of solving the object of the present
invention when in use, depending on the shape and function of
the container portion and the area of the opening part in the
portion. For example, a lid means having a multilayer structure
comprising a layer corresponding to the outer layer of the
above-mentioned container portion, optionally a layer(s)
corresponding to the middle- and/or inner-layers, and more
optionally a layer(s) corresponding to the outermost- and/or
moistureproof-layers can be usually advantageously used as the
lid means of the present invention. Furthermore, similarly as
the outer- and inner-lids, the lid means can be constructed into
a structure comprising at least two independent lid means
materials having either of the above-mentioned layers. In this
case, each lid means materials can be arbitrarily made into
either a structure where they are closely attached together, or
a structure where an appropriate space is provided between them:
In the latter structure, the space will exert a similar function
as in the air layer in the middle layer of the container
portion. The shape of a lid means for making the internal part
of the container portion into a sealed condition and the method
therefor can be appropriately selected, depending on the shape
of the container portion and the lid means, within the
limitation that they do not affect the effect of solving the
object of the present invention. For example, to a container
portion having an opening part on the top face, a lid means like
a lid means 2 as shown in FIGs. 3 to 5 and FIGs. 7 to 9 is
formed to close each opening part in each container without any
gap and then placed on the container portions from their upper
sides, resulting in attaining a sealed condition in the
container portions. Similarly as in the lid means 2
respectively shown their longitudinal sectional views and
perspective views of FIGs. 10 and 11, the desired sealed
condition is attained by inserting the container portion into
the lid means when the lid means is formed in such a manner of
surrounding the periphery of the container portion without any
gap and then forming into a box shape having partially an
opening part. Independently of the position of the opening part
of the container portion, the sealed condition or the open
condition of the container portion can be appropriately attained
without separating the lid means and the container portion by
forming the lid means into a shape such as a plate shape capable
of sealing the opening part and then installing the resulting
lid means in either end of the opening part of the container
portion using a metal part, etc., to allow the lid means to be
freely opened or closed. If necessary, the fireproof container
of the present invention thus obtained can be arbitrarily
installed with handles or wheels to improve its
transportability, or imparted with a lock function.
-
The fireproof container thus constructed has usually
improved transportability and a fire resistivity far exceeding
the function of "1-hour fire resistivity for papers in general"
that is confirmed when subjected to "1-hour standard heat test"
defined in "JIS Fire-resistive container(s)". Explaining
briefly the standard heat test in the above definition, first,
provide a furnace as a heating furnace for test which gives a
time-dependent thermal change along the standard thermal curve
in FIG. 2 substantially uniformly over the whole surface except
for the bottom part of a test product (a fireproof container),
when a test product is placed therein. Then, place in the
furnace the test product provided previously with a thermometer
or thermo couple in or on the surface of the furnace, and then
heat the test product in the furnace to change the surface
temperature of the test product along the standard thermal
curve. During the heating, the inner temperature of the test
product is measured at appropriate times. When a prescribed
time has passed, terminate the heating, gradually allow to cool,
and then measure the inner temperature of the test product.
Depending on the time period before termination of heating, it
is called, for example, "1-hour standard heat test", "2-hour
standard heat test", etc. The performance of "1-hour fire
resistivity for papers in general", defined in the above
definition, means an ability that keeps the peak of the inner
temperature at temperatures not exceeding 177° C during the
heating for one hour according to the standard heat test, and
then cooling the heated test product until the lowering of the
inner temperature is observed. The fireproof container of the
present invention has an ability that keeps its inner
temperature at temperatures distinctively below 177°C, usually,
not higher than 165°C, preferably, not higher than 150°C, and
more preferably, not higher than 130°C under the 1-hour standard
heat test. In addition to this fire resistivity, the fireproof
container has also a satisfactory transportability. Varying
depending on the capacity or the ability, conventional 20 L-fireproof
containers for papers in general have a total weight
of at least 80 kg or at least 100 kg, however, the fireproof
container of the present invention with a capacity equivalent
to conventional ones weighs usually 40 kg or lower, preferably,
20 kg or lower, and more preferably, 10 kg or lower.
-
The above-mentioned fireproof container of the present
invention is particularly useful as a container for storing
articles, which are directed to be handled by conventional
fireproof containers, such as notes, coins, valuables,
securities, muniments, as well as those which should be avoided
from quality deterioration, for example, art products including
valuable antiques such as paintings, scroll pictures, ceramics,
porcelains, lacquer wares, swords, body armors, and ancient
documents; and flushable/ignitable substances and articles. The
structure of the fireproof container of the present invention
disclosed in the specification can be applied to structures
other than containers for storing articles. Examples of such
applications include containers for transporting articles with
different sizes such as personal use suit cases and containers
for automobiles, ships and passenger airplanes; boxes for
enclosing, storing or arranging articles for personal and
business use; bodies for electronic appliances; and structures
for enclosing electronic appliances in constructions. Since the
fireproof container of the present invention has a character of
lightweight, the structure of the container is applicable to
larger-sized constructions. For example, by applying the
structure according to the present invention to wall materials
in constructions, constructions in general and others such as
storehouses for storing articles which should be avoided from
quality deterioration, or an additional room in constructions
can be formed; or by employing the structure of the fireproof
container according to the present invention as a structure for
enclosing skeleton framings or earthquake-resistive devices in
constructions, particularly, high buildings, the main part
products of these constructions can be protected from fire. In
addition, when employed in the structure of bodies of
transporting means such as automobiles, ships and airplanes, the
structure of the present invention improves their fire
resistivity; and when employed in the structure of the body of
spaceships such as space shuttles, which are repeatedly used in
traveling between the inner and outer atmosphere, the structure
of the present invention would advantageously inhibit the
increase of inner temperature of the spaceships when plunging
into the atmosphere. The structure of the fireproof container
of the present invention can be applied to structures where the
shielding of heat from articles/substances with a potential heat
generation or in a high temperature condition. For example, the
application of the structure of the fireproof container of the
present invention to the structure for enclosing electric
products with a potential heat generation and to the structure
for factories which handle articles/substances with a potential
heat generation or for a room in the factories can minimize the
level or range of disasters caused by abrupt heat generation
from such articles/substances. In this case, the
directional/positional arrangement in the multilayer structure
in the fireproof container can be arbitrarily reversed. When
prepared previously is a multilayer product in a plain shape
having a structure corresponding to the multilayer structure for
constituting the container portion of the fireproof container,
the multilayer product per se can be made into a refractory
panel usable in various fields; such a panel can be used as a
material for the fireproof container of the present invention,
material for the aforesaid containers for transportation,
construction material for the above-mentioned constructions, and
structure material of the body of the above-mentioned
spaceships.
-
The above materials having endothermic property used
in the fireproof container, particularly, saccharides exert a
distinctive effect of solving the object of the present
invention when constructed into the fireproof container as a
part, and exert the desired endothermic property when used
separately from the fireproof container. Because of these, they
can be advantageously used alone, for example, as an agent for
inhibiting the increase of temperature (may be designated as
"temperature increase preventive", hereinafter), in such a
manner of being placed in the container portion. Based of the
fact, the present invention provides an agent for inhibiting the
increase of temperature comprising a saccharide(s) as an
effective ingredient. Any ingredients in any forms can be used
in the temperature increase preventive of the present invention,
as long as the preventive comprises one or more of the above
saccharides and stands in a condition capable of exerting the
inherent thermal property. For example, the temperature
increase preventive is provided in the form of a composition
either consisting of the above saccharide(s) or others
comprising the above saccharide(s) and at least one of pigments,
fragrances, deodorants, moth-proofing agents, fungicides, and
moisture-absorbers, where the content of the saccharide(s) is
usually at least 80%, and preferably, 90-100% by weight. The
temperature increase preventive of the present invention can be
optionally provided in a form prepared by injecting the
saccharide(s) into bags prepared by sewing fabrics, non-fabrics
or the like prepared with materials having moisture-permeability
and/or flexibility such as Japanese/Chinese papers, natural
fibers, synthetic fibers, and fireproof fibers. When used by
placing in the fireproof container, the temperature increase
preventive preferably contains the saccharide(s) in an amount,
usually, of about 1 to about 1,000 g, preferably, about 10 to
about 500 g, varying dependently on the size of the fireproof
container and the kind/type of storing articles. By placing one
or more of the above temperature increase preventives of the
present invention in conventional fireproof containers or in the
fireproof container of the present invention depending on the
volume of each of the container portions, the increase of inner
temperature of these containers will be more effectively
inhibited. Of course, the temperature increase preventive of
the present invention can be used by placing in constructions
other than fireproof containers, it can be advantageously
practiced in such a manner of placing in containers for
transporting articles, constructions, or in a room of the
constructions to inhibit the increase of inner temperature
thereof when externally heated, or inversely in such a manner
of placing in constructions for storing/transporting
articles/substances with a potential heat generation to inhibit
their heat emission to the outside of the constructions. In
addition to the use in walls for fireproof constructions, the
temperature increase preventive can be used as a partial
material for transporting means in general such as automobiles,
ships, and airplanes, as well as for the body of spaceships such
as space shuttles used repeatedly in traveling between the inner
and outer atmosphere, to improve the fire resistivity of the
constructions per se; or used as a partial material for
constructing an enclosing structure for imparting fire
resistivity to skeleton framings and earthquake-resistive
devices in constructions, to improve the fire resistivity of the
enclosing structure.
-
Also, the present invention provides a temperature
increase preventive construction, comprising, at least as a
partial construction material, the temperature increase
preventive of the present invention. The term "temperature
increase preventive construction(s)" as referred to as in the
present invention means a construction(s) capable of shielding
or inhibiting the heat conduction from heat sources or a part
of the construction(s): For example, the term means panels and
sheets, as well as containers, bags, and the like with different
sizes and shapes prepared with the panels and sheets. The term
"comprises at least as a partial construction material" as
referred to as in the present invention means that the
temperature increase preventive constructs the above temperature
increase preventing construction alone or in combination with
another material(s), where the preventive should preferably be
contained in the construction in such a manner of being
contactable with the outside air. For example, as for the
panels, constructions prepared by injecting the temperature
increase preventive of the present invention into the space
formed between two plate products made of a desired material(s)
such as ceramic fibers, aluminum fibers, insulating firebricks,
potteries, aerated concretes, woods, and papers including
cardboards and corrugated fiberboards; sealing around the
periphery of opening of the plate products; attaching the
temperature increase preventive, injected into bags with the
desired sizes and shapes, onto a part or the whole surface of
plate products made of the desired material; or piling up both
the temperature increase preventives, which have been previously
formed in a plate form using an adequate adhesive, and a desired
plate product into multilayer products. As for the above-described
sheets, constructions prepared by sewing fabrics, non-fabrics,
sheets or the like made of the desired materials into
bag-shaped products; injecting the temperature increase
preventive into the products; and optionally further sewing the
products into quilting-like products or sewing the temperature
increase preventives, which have been injected into bags with
the desired sizes and shapes, onto a part or the whole surface
of the desired fabrics, non-fabrics, sheets or the like. By
using the above-mentioned constructions as a partial material
and forming them into containers or bags with the desired
shapes, the following products can be made: Containers,
depositories, storages, transporting containers and the like
usable for storing, housing, or transporting articles which
should be avoided from temperature increase and, reversely,
those which have a potential heat generation. The temperature
increase preventive constructions in the form of a panel or
sheet according to the present invention can be arbitrarily used
as construction materials for larger-sized constructions,
automobiles, ships, airplanes, airships, spaceships, and the
like.
-
The following experiments and examples describe the
present invention in more detail:
Experiment: Quality deterioration of storing articles by heating
-
Samples were subjected to the following heat test to
examine the quality deterioration of papers, woods, and cloths,
which are the main ingredients for material property such as art
products and are poor in fire resistivity, when subjected to
heating conditions. As samples, 14 samples in the Table 1 below
having a rectangular shape with a size of 6 to 7 cm in length
and 7 to 10 cm in wide, and, for wood specimens, having a
thickness of about one centimeter, were used. The heating of
the samples was carried out by keeping them in an electric
furnace adjusted to any of temperatures, as inner temperatures,
in Table 1 for respective periods of time while being hung with
metal rods and kept not to contact with the walls of the
furnace. The evaluation of the test was done based on the
microscopic observation by five persons who engaged in art
museums, where the samples after the heat treatments were
evaluated in five ranks with respect to standard samples with
no heat treatment: The symbol "o ○" means that no substantial
quality deterioration is found; "○", quality deterioration is
found but quite slight; "Δ", relatively clear quality
deterioration is found but acceptable as the quality change of
art products that is inescapable of secular change; "x", clear
quality deterioration is found and unacceptable even though
considering the quality change of art products inescapable from
secular change; and "xx", high level of quality change is found
and thoroughly unacceptable. The evaluations shown by most of
the panels are tabulated in Table 1. The evaluation results
were judged to be sufficiently reliable because each result in
Table 1 was one well coincided with those of at least four
panels out of five.
-
As evident form Table 1, it was revealed that the
papers, woods and cloths generally showed no or a passable range
of quality deterioration up to 130°C when heated within six
hours, and most of them excluding some papers had a roughly
acceptable range of quality deterioration even when heated at
about 140°C. These results show that the fireproof ability of
acceptable inner temperature of 177° C in fireproof containers
for general papers defined in "JIS Fire-resistive container(s)",
i.e., the fireproof ability of fireproof containers now widely
used well, is not necessarily sufficient as a fireproof ability
for storing articles which should be avoided from quality
deterioration.
Example 1 : Fireproof container and its fireproof ability
Example 1-1 : Fireproof container
-
As an embodiment of the fireproof container of the
present invention, a fireproof container A, having the structure
shown in typically with its longitudinal sectional view of FIG.
3, was prepared. As shown in FIG. 3, in a container portion 1
in the fireproof container A, an outer layer 1a is a layer,
having 100 mm in thickness, made of "ISOWOOL® 1260 BOARD", a
ceramic fire board as a fireproof insulation material
commercialized by Isolite Insulating Products Co., Ltd., Tokyo,
Japan; an inner layer 1b is a layer having 10 mm in thickness
made of "ISOLITE C-1", an insulating firebrick as an
incombustible material commercialized by Isolite Insulating
Products Co., Ltd., Tokyo, Japan; and a middle layer 1c is an
air layer, having 10 mm in thickness, provided via a spacer 1d
made of the above insulating firebrick. A lid means 2 is
composed of an inner lid, comprising a layer 2b having 10 mm in
thickness, which is made of the above insulating firebrick
corresponding to the inner layer 1b, placeable on the inner
layer 1b, and in the form of plate with an appropriate size
capable of keeping the inner part of the container portion 1 in
a sealed condition; and an outer layer, comprising a layer 2a
having 100 mm in thickness, which is made of the above
insulating firebrick corresponding to the outer layer 1a, and
has an appropriate size suitably placeable on the outer layer
1a at a distance of 10 mm apart from the inner layer. As shown
in FIG. 3, when the inner and outer lids as part products of the
lid means 2 are provided on the opening part of the container
portion 1, a space formed between the lids results in a layer
2c corresponding to the middle layer 1c of the container portion
1. When the lid means 2 is provided on the container portion
1, the fireproof container A has the following sizes: 63 cm in
wide, 59 cm in depth, and 40 cm in height, where the term "wide"
means the right and left directions with respect to those on the
paper of FIG. 3, and the term "depth" means the vertical
direction with respect to the surface of the paper of FIG. 3.
Throughout FIGs. 3 to 5 and FIGs. 7 to 10, the symbol 3 shows
a storing article.
-
As an another embodiment of the fireproof container
of the present invention, a fireproof container B, having the
structure shown in typically with its longitudinal sectional
view of FIG. 3, was prepared. As shown in FIG. 4, the fireproof
container B has totally the same structure as of the fireproof
container A except that a middle layer 1c, having 10 mm in
thickness, which is made of a hydrous crystalline trehalose
powder ("TREHA®" commercialized by Hayashibara Shoji Inc.,
Okayama, Japan), as a material with a desired endothermic
property, was provided by injecting the powder into the space
formed between the outer and inner layers, in place of the
middle layer containing the spacers in the container portion of
the fireproof container A.
-
As a still another embodiment of the fireproof
container of the present invention, a fireproof container C,
having the structure shown in typically with its longitudinal
sectional view of FIG. 5, was prepared. As shown in FIG. 5, the
fireproof container C has totally the same structure as of the
fireproof container B except that 1,246 g by weight of a hydrous
crystalline trehalose powder, as a temperature increase
preventive 1e, which had been injected into a silk bag, was
placed in the container portion 1.
-
As controls the following were made: A container X1
consisting of the outer layer and the outer lid having 100 mm
in thickness each as in the fireproof container A; and a
container X2 having the same structure as of the container X1
except for making both the outer layer and the outer lid to give
a thickness of 120 mm.
Example 1-2 : Standard heat test
-
The fireproof containers A, B and C in the above
example and the containers X1 and X2 as controls were subjected
to the 1-hour standard heat test specified in "JIS Fire-resistive
container(s)" to examine the inner temperature change
of their container portions. The results are in FIG. 6. In
FIG. 6, the curves A, B and C are respectively the inner
temperature changes for the fireproof containers A, B and C; and
the curves X1 and X2 are respectively those for the container
portions X1 and X2. In this test, a box of Paulownia wood as a
model of storing article was placed in each container portion
and, after completion of the test, the condition of the boxes
were macroscopically observed.
-
As shown in FIG. 6, the peak of inner temperature of
the fireproof container A was about 160°C, and those of the
fireproof containers B and C were respectively about 130°C and
about 120°C. With regard to the condition of the boxes of
Paulownia wood, the fireproof container A gave a slight partial
color change of the box but did not burn it, and the boxes in
the fireproof containers B and C showed no substantial quality
change. These results show that the fireproof containers of the
present invention have an ability far exceeding the ability of
"1-hour fireproof of papers in general", i.e., an ability of
keeping the inner temperature of 177°C or lower on the 1-hour
standard heat test, specified in "JIS Fire-resistive
container(s)"; and among of these fireproof containers, the
fireproof containers with layers, as middle layers, made of
materials with a desired endothermic property are particularly
advantageous for storing articles including art products which
should be avoided from quality deterioration. While the
containers X1 and X2 as controls, their inner temperatures far
exceeded over 200°C, and the boxes of Paulownia wood had totally
burned brown. As evident from the results, in the case of
constructing a container with only the outer layer according to
the present invention, the fire resistivity tends to be improved
by increasing the thickness of the layer, however, it must be
made into a layer with a highly larger thickness to attain the
desired fire resistivity. Therefore, the above results indicate
that the structure consisting of the outer layer according to
the present invention could not substantially solve the object
of the present invention. Also as found in FIG. 6, in the above
heat test, the times, at which the inner temperatures of the
fireproof containers A, B and C of the present invention reached
their peaks, were all later than those of the containers X1 and
X2 as controls. This means that the fireproof containers of the
present invention afford the time needed until they are brought
out when in fire.
Example 2 : Fireproof container
-
A fireproof container, having the structure shown in
typically with its longitudinal sectional view of FIG. 7,
according to the present invention, was prepared. As shown in
FIG. 7, the fireproof container has totally the same structure
as of the fireproof container C in Example 1 except that
moistureproof layers 1f and 2f, made of a laminated aluminum
foil, were respectively placed between the outer layer 1a and
the middle layer 1c in the container portion 1, and on the
surface of the layer 2a in the lid means, facing to the side of
the container portion 1.
-
The product has advantageous fire resistivity and
transportability, will not be affected even when sprayed with
water due to fire fighting when in fire, and also has the merit
that it can be reused even after sprayed with water.
Example 3 : Fireproof container
-
A fireproof container, having the structure shown in
typically with its longitudinal sectional view of FIG. 8,
according to the present invention, was prepared. As shown in
FIG. 8, the fireproof container has totally the same structure
as of the fireproof container in Example 2 except that the
outermost layers 1g and 2g, having 1.5 mm in thickness, made of
aluminum, were provided outside of an outer layer via aluminum
block spacers 1d and 2d.
-
The product has good durability against direct fire,
has advantageous fire resistivity and transportability, will not
be affected even when sprayed with water due to fire fighting
when in fire, and also has the merit that it can be reused even
after sprayed with water.
Example 4 : Fireproof container
-
A fireproof container, having the structure shown in
typically with its longitudinal sectional view of FIG. 9,
according to the present invention, was prepared. As shown in
FIG. 9, the fireproof container has totally the same structure
as of the fireproof container C in Example 1 except that the
outermost layers 1h and 2h, made of a moisture permeable cloth,
were provided outside of an outer layer.
-
The product has advantageous fire resistivity,
transportability, and fine spectacle, and similarly as the
fireproof container C with no outermost layer, it has the merit
that the moisture within the container portion can be controlled
by regulating the outer circumstance while storing articles.
Example 5 : Fireproof container
-
A fireproof container, having the structure shown in
typically with its longitudinal sectional view of FIG. 10 and
its perspective view of FIG. 11, according to the present
invention, was prepared. As shown in FIG. 10, in the container
portion 1 of the fireproof container, an outer layer 1a is a
layer made of "ISOWOOL® 1260 BOARD" commercialized by Isolite
Insulating Products Co., Ltd., Tokyo, Japan; an inner layer 1b
is a layer, having 10 mm in thickness, made of "ISOLITE C-1",
an insulating firebrick as an incombustible material
commercialized by Isolite Insulating Products Co., Ltd., Tokyo,
Japan; and a middle layer 1c is a layer of "TREHA®", a hydrous
crystalline trehalose powder commercialized by Hayashibara Shoji
Inc., Okayama, Japan, having 10 mm in thickness, prepared by
injecting the powder into the space formed between the outer
layer 1a and the inner layer 1b. A lid means 2 surrounds the
whole outer surface of a container portion 1 without gap, has
a box-like form with a partial opening part, and comprises a
layer 2a corresponding to the outer layer 1a of the container
portion 1, and layers 2b and 2c, corresponding to the inner
layer 1b and the middle layer 1c of the container portion 1,
respectively, which are provided on the surface that contacts
with the opening part of the container portion 1. The outer
layer of the fireproof container in this example has a thickness
of 100 mm as of the container portion or the lid means, or of
the container portion plus the lid means.
-
Since the product has advantageous transportability
and a structure for inserting the container portion into the lid
means, it can keep the sealed condition in the container portion
at a higher level, resulting in a characteristic exertion of
particularly advantageous fire resistivity.
Example 6 : Temperature increase preventive
-
Two sheets, having about 10-cm-square, of a satin silk
cloth, were sewed together except for leaving only a pair of
sides, into a bag-shaped product which was then injected with
"TREHA®", a hydrous crystalline trehalose powder commercialized
by Hayashibara Shoji Inc., Okayama, Japan, followed by sewing
the remaining pair of sides to obtain a temperature increase
preventive in the form of a Japanese cushion. The product
contains about 150 g of trehalose.
-
By placing in the fireproof container of the present
invention, as well as in conventional containers and others for
storing and transporting, constructions, and a room thereof, the
product will effectively prevent the inner temperature increase
of the above products when exposed to heating conditions such
as fire.
Example 7 : Temperature increase preventive
-
A rectangular cotton sheet (cotton count No. 10),
having about 20-cm on a longer side and about 9-cm on a shorter
side, where the two longer sides were sewed together and either
of a pair of the shorter sides was sewed to form a bag-shaped
product which was then injected with "TREHA®", a hydrous
crystalline trehalose powder commercialized by Hayashibara Shoji
Inc., Okayama, Japan, followed by sewing the remaining pair of
the shorter sides to obtain a temperature increase preventive
in the form of a column. The product contains about 100 g of
trehalose.
-
By placing in the fireproof container of the present
invention, as well as in conventional containers and others for
storing and transporting, constructions, and a room thereof, the
product will effectively prevent the inner temperature increase
of the above products when exposed to heating conditions such
as fire.
Example 8 : Temperature increase preventive
-
A flax (cotton count No. 60) was sewed into an
otedama-like bag (a beanbag), having a partial opening part and
having about 5-cm in wide, depth and height, which was then
injected with a hydrous crystalline tetracyclic saccharide,
which had been prepared in conventional manner as disclosed by
G. M. Bradbrook in Carbohydrate Research, Vol. 329, pp. 655-665
(2000), followed by sewing the opening part to obtain a
temperature increasing preventive in the form of an otedama.
-
By placing in the fireproof container of the present
invention, as well as in conventional containers and others for
storing and transporting, constructions, and a room thereof, the
product will effectively prevent the inner temperature increase
of the above products when exposed to heating conditions such
as fire.
Industrial Applicability
-
As described above, the present invention was made
based on the completely novel self-finding that a fireproof
container having both outstandingly advantageous fire
resistivity and transportability is obtained by forming the
fireproof container comprising a multilayer structure of an
outer-, middle- and inner-layers positioning in this order from
the outside to the inside portions thereof, wherein in the
multilayer structure a layer as the outer layer comprising a
fire-resistant insulating material having a bulk specific
gravity of not higher than 1.0 g/cm3, which has not been used as
a partial structure for fireproof containers, is employed in
combination with both a layer as the middle layer comprising a
material having an air-spaced layer and/or endothermic property,
and a layer as the inner layer comprising an incombustibility
material having a bulk specific gravity of not higher than 2.0
g/cm3. The fireproof container of the present invention is
advantageously useful for storing articles to which conventional
fireproof containers are applied, and others including art
products whose quality deterioration should be avoided. In
addition, the structure of the fireproof container disclosed by
the present invention can be used in fireproof containers for
storing articles for personal and business uses, and are
applicable to containers for transporting articles such as
suitcases and containers, as well as to the structures for the
whole or a room(s) of constructions, those for enclosing
skeleton framings and earthquake-resistive devices in
constructions, those for the bodies of automobiles, ships, and
airplanes; and others for the body of spaceships used repeatedly
in traveling between the inner and outer atmosphere.
-
The present invention having such advantageous
functions and effects is a significant invention that will
greatly contribute to this art.