JP6367047B2 - Vacuum heat insulating material and manufacturing method thereof - Google Patents

Description

  The present invention relates to a vacuum heat insulating material and a method for manufacturing the same, and more particularly to a vacuum heat insulating material that can handle a curved wall and a method for manufacturing the same.

Conventionally, as a heat insulating material for a heat-insulated body having a curved surface, a heat insulating material made of a soft material such as Aeroflex (registered trademark, flexible special elastomer heat insulating material having a closed cell structure) or urethane foam has been used.
Further, for example, Patent Documents 1 to 3 have been proposed as foldable vacuum heat insulating materials.
Patent Document 1 is a vacuum heat insulating material in which a plate-shaped core material having two opposing heat transfer surfaces is covered with a gas barrier outer covering material, and the inner portion of the outer covering member is decompressed and sealed. Has a net-like recess that is bent by forming a plurality of folding lines in three or more directions in a portion covering at least one heat transfer surface of the core material in the jacket material, and a vacuum heat insulating material in the heat insulating material The vacuum heat insulating material is arranged along the curved surface of the body to be insulated by bending the plurality of portions of the net-like recesses to deform the vacuum heat insulating material so as to conform to the shape of the curved surface to be arranged. is there.
In Patent Document 2, a vacuum heat insulating material is formed by covering a core material made of powder with an inner packaging material, which is a continuous packaging body divided into squares by thermal welding, with a gas barrier outer covering material, and reducing the inside. The core material 3 is thermally welded and integrated on the front and back of the inner packaging material and the outer covering material, thereby forming an independent space. Therefore, it has the softness | flexibility bent at a heat welding part. Moreover, if it cut | disconnects in a heat welding part, it can be set as the vacuum heat insulating material with an arbitrary shape and a large effective cross-sectional area.
Patent Document 3 is formed by covering a core material made of glass fibers formed in a plurality of substantially regular octagons with a gas barrier outer covering material and reducing the inside, and the core material is parallel to each side of the octagon. Are arranged at predetermined intervals in a lattice shape so as to form vertical, horizontal, and diagonal 45-degree folding lines, and the outer periphery of the core material is positioned so that a plurality of core materials are located in independent spaces. The material is a heat-welded part and has flexibility to be bent in four directions. Moreover, if the heat welding part along a core material is cut | disconnected so that a circumference | surroundings of about 3 mm may remain | survive, it can be set as a vacuum heat insulating material with an arbitrary shape and a large effective heat insulation area. Furthermore, the shape of the core material itself can be arbitrarily set to cope with complicated shapes, through holes, and the like, and any of them can be a vacuum heat insulating material capable of meeting a very wide range of purposes.

JP 2008-202709 A JP 2007-132425 A JP 2004-197935 A

For example, a hydrogen storage alloy tank will be described as an example of a heat-insulated body having a curved surface. When using the alloy reaction heat associated with the storage and release of hydrogen in the hydrogen storage alloy, as much alloy reaction heat as possible is recovered. In order to prevent heat from escaping from the hydrogen storage alloy tank, it is necessary to cover the outer wall of the alloy tank with a heat insulating material. Since the outer cylinder of the alloy tank is generally cylindrical, a heat insulating material made of a soft material such as Aeroflex (registered trademark, flexible special elastomer heat insulating material with closed cell structure) or urethane foam has been used. However, when these heat insulating materials are used to obtain sufficient heat insulating performance, the thickness increases, and the capacity of the alloy tank including the heat insulating materials increases, which causes a problem in securing the installation location.
Therefore, attention has been paid to the conventional vacuum heat insulating materials such as the above-mentioned Patent Documents 1 to 3, but the hydrogen storage alloy tank has a cylindrical shape, and these conventional vacuum heat insulating materials cannot be in close contact with the curved surface of the tank side surface. As a result, sufficient heat insulation performance cannot be obtained. This is because, in the above-described prior art that can be folded, as shown in FIG. 1, the core portion is formed of a flat surface, so that it cannot sufficiently adhere to the cylindrical curved surface of the tank. Then, the jacket material part is not thermally insulated from the vacuum, and there arises a problem that heat penetration or heat escapes from there and a sufficient heat insulation performance cannot be obtained.
Therefore, the problem to be solved by the present invention is to provide a vacuum heat insulating material that can be tightly attached to the curved wall of the object to be heat-insulated and to provide a manufacturing method thereof.

In order to solve the above-described problems, the present invention provides a core material sheet in which protruding microstructures for ensuring a vacuum space are provided on both surfaces of a flexible base material, and a gas barrier property covering the core material sheet. It is a vacuum heat insulating material made of a jacket material, in which an inner space in which the core sheet is covered with the jacket material is sealed under reduced pressure.
The present invention also provides a core material sheet in which projecting microstructures for securing a vacuum space are provided on both surfaces of a flexible base material, wherein a plurality of hole-like spaces are formed in the core material sheet. A plurality of the core material sheets are laminated, and the core material is arranged and laminated so that the hole-like spaces between the core material sheets of the adjacent layers are shifted from each other; and a gas barrier outer covering covering the core material It is a vacuum heat insulating material made of a material, in which an inner space in which the core material is covered with the jacket material is sealed under reduced pressure.
In the vacuum heat insulating material according to the present invention, the protruding microstructure is a male piece and a female piece of a hook-and-loop fastener.
The present invention further includes a belt-like surface fastener in which male and female surface fasteners are arranged on both surfaces of a flexible base material in a lattice shape, and further covers a space portion of the lattice overlapped in the lattice shape. A core material configured by stacking at least one layer of belt-shaped surface fasteners and a gas barrier outer covering material that covers the core material, and an internal space in which the core material is covered with the outer covering material is sealed under reduced pressure. It is a vacuum heat insulating material.
In the vacuum heat insulating material according to the present invention, the belt-shaped surface fastener is a binding band.
The present invention also includes a step of covering a core material sheet provided with a projecting microstructure for securing a vacuum space on both surfaces of a flexible base material with a gas barrier outer covering material, and the core material sheet A method for manufacturing a vacuum heat insulating material, comprising: a step of sealing an inner space covered with the jacket material under reduced pressure.
The present invention also provides a core sheet in which protruding microstructures for securing a vacuum space are provided on both surfaces of a flexible base material, and a core in which a plurality of hole-shaped spaces are formed. A step of constructing a core material by laminating a plurality of material sheets and arranging and laminating so that the hole-like spaces between the core material sheets of adjacent layers are shifted, and covering the core material with a gas barrier covering material It is a method for producing a vacuum heat insulating material comprising a step and a step of sealing the inner space in which the core material is covered with a gas barrier covering material under reduced pressure.
The present invention further includes a belt-like surface fastener in which male and female surface fasteners are disposed on both sides of a flexible base material in a lattice shape, and further covers a space portion of the lattice overlapped in the lattice shape. A step of constructing a core material by stacking at least one layer of belt-shaped surface fasteners, a step of covering the core material with a gas barrier outer covering material, and a decompression of an internal space where the core material is covered with a gas barrier outer covering material It is a manufacturing method of the vacuum heat insulating material which consists of a process to seal.

In the present invention, since the core material itself is a flexible and bent structure, a wide vacuum heat insulating portion can be secured, and if the core material has a laminated structure, a vacuum space can be increased and desired heat insulation can be achieved. Performance can be realized.
Furthermore, if a packaging material for a vacuum pack having a gas barrier property and a degassing sealer as a covering material and a degassing sealer are available, it can be easily manufactured at low cost. Moreover, it becomes a vacuum heat insulating material which can be used in a high temperature area | region by making the structural member of a core material, and a covering material respond | correspond to high temperature.

FIG. 1 is a view showing a conventional vacuum heat insulating material. FIG. 2 is a diagram illustrating a core material in the vacuum heat insulating material according to the first embodiment of the present invention. In order to complete the vacuum heat insulating material, the illustrated core material is covered with a gas barrier covering material, and the inside is sealed under reduced pressure to obtain a vacuum heat insulating material. FIG. 3 shows an example in which the conventional Aeroflex (registered trademark) heat insulating material and the vacuum heat insulating material of Example 1 are applied to a hydrogen storage alloy tank having an outer diameter of 16.5 cmφ, where (a) is the thickness. 6 cm of conventional Aeroflex (registered trademark) insulation material is used, (b) uses the vacuum insulation material of Example 1 with a thickness of 6 mm and conventional Aeroflex (registered trademark) insulation material with a thickness of 1 cm for cosmetic use. It is a thing. FIG. 4 is a diagram showing experimental results comparing the heat insulation performance of FIGS. 3a and 3b. In FIG. 4, (a), (b), and (c) are pressure-composition-temperature (PCT) curves when only 6 cm thick conventional thermal insulation material Aeroflex (registered trademark) is used (see FIG. 3a), hydrogen These are the time variation of the tank internal temperature, circulating water inlet / outlet temperature and tank internal pressure during occlusion, and the time variation of the tank internal temperature, circulating water inlet / outlet temperature and tank internal pressure during hydrogen release. 4 (d), (e), and (f) are pressure-composition-temperature (PCT) curves when the vacuum heat insulating material of Example 1 is employed (see FIG. 3b), the tank internal temperature during hydrogen storage, These are time changes in circulating water inlet / outlet temperature and tank internal pressure, tank internal temperature at the time of hydrogen release, circulating water inlet / outlet temperature and tank internal pressure. FIG. 5 is a diagram illustrating a core material in the vacuum heat insulating material according to the second embodiment of the present invention. In order to complete the vacuum heat insulating material, the illustrated core material is covered with a gas barrier covering material, and the inside is sealed under reduced pressure to obtain a vacuum heat insulating material. FIG. 6 is a diagram illustrating the core material in the vacuum heat insulating material according to the third embodiment of the present invention. In order to complete the vacuum heat insulating material, the illustrated core material is covered with a gas barrier covering material, and the inside is sealed under reduced pressure to obtain a vacuum heat insulating material.

The inventors of the present invention used a band-shaped surface fastener such as a binding band that can be softly bent and can secure a fine vacuum space on the core material of the vacuum heat insulating material, and the band-shaped surface fasteners stacked in a lattice shape. We have developed a flexible vacuum heat insulating material that can be used as a core material, covered with a jacket material with a gas barrier property, and sealed inside under reduced pressure to adhere to a curved wall.
In addition, a soft and foldable core material with protruding microstructures that can secure a vacuum space on both the front and back sides of a thin and flexible substrate is covered with a jacket material that has gas barrier properties, and the inside is sealed under reduced pressure to provide a curved wall Developed a flexible vacuum insulation material that can adhere to the surface.
Furthermore, in order to increase the heat insulation by the vacuum space and reduce the heat conduction by the core material, it can be bent softly by arranging the protruding microstructures that can secure the vacuum space on both the front and back sides of the thin and flexible substrate. A plurality of spaces (holes) are made in the core material and the core materials are stacked to be multi-layered, and the core materials of the overlapping layers are arranged so as to be displaced so that the multi-layer core material has gas barrier properties. We have developed a flexible vacuum heat insulating material that can be covered with a substrate and sealed inside under reduced pressure to adhere to the curved wall. In addition, in the case of multilayering, if the projecting microstructure is composed of male and female pieces of a hook-and-loop fastener, the overlapping core members are formed by the engagement of the male and female pieces when multilayered. Appropriate sticking and loss of shape can be prevented.

Example 1
FIG. 2 is a view for explaining the core material in the vacuum heat insulating material of Example 1 which is an embodiment of the present invention. In Example 1, a belt-shaped surface fastener known as a binding band or the like is used as the core material. Use. As shown in the right figure of FIG. 2, the belt-shaped hook-and-loop fastener has male and female pieces of hook-and-loop fasteners on both sides of the belt-like flexible base material. In the figure, the hook is a typical example of male and female pieces. Although the structure of the male piece and the female piece is not limited to the hook and the loop, any structure can be adopted as long as the structure is a male piece and a female piece used in the hook-and-loop fastener. As can be seen from the figure, there is a fine space at the base of the hooks and loops that are male and female pieces, and heat transfer due to heat conduction is greatly limited by evacuating this space, and it has good performance Can be configured. Furthermore, in order to suppress heat conduction by the belt-shaped surface fastener itself, as shown in the left figure of FIG. 2, the amount of the belt-shaped surface fastener is reduced and the space for vacuum is increased as much as possible. (In the figure, in order to make the explanation easy to understand, three strip surface fasteners are placed on the side, and seven strip surface fasteners are stacked vertically).
Then, from the state of the left figure in FIG. 2, the belt-like surface fasteners are overlapped horizontally so as to cover the space portion of the lattice (in the case of the figure, it is two horizontally), and the belt-like surface fasteners are vertically stacked (in the figure). (In some cases, the length is six), and a structure made by sequentially laminating belt-shaped surface fasteners is used as the core material of the vacuum heat insulating material, which is covered with a jacket material having a gas barrier property, and the inside is sealed under reduced pressure. Thus, a flexible vacuum heat insulating material that can cope with a curved wall can be realized.
When the belt-shaped surface fasteners are stacked, the belt-shaped surface fasteners in which the male pieces and the female pieces are engaged and overlapped with each other can be connected to each other, or the once-connected belt-shaped surface fasteners can be peeled off. In addition, since the male piece and the female piece are connected to each other, they can be prevented from being deformed and can be deformed to some extent according to the curved surface.

FIG. 3 compares the case where Aeroflex (registered trademark), which is a conventional heat insulating material, and the vacuum heat insulating material of Example 1 of the present invention are applied to a hydrogen storage alloy tank. The length of the hydrogen storage alloy tank is 1 m, and the outer diameter is about 16.5 cmφ. FIG. 3 (a) all uses Aeroflex (registered trademark), which is a conventional heat insulating material, and has an outer diameter of about 28.5 cmφ. On the other hand, FIG. 3B shows a case where the vacuum heat insulating material having a thickness of about 6 mm of Example 1 is applied to a cylindrical side wall, and Aeroflex (registered trademark) heat insulating material having a thickness of 1 cm is applied for makeup. It can be seen that the outer diameter is slim, about 19.7 cmφ. The vacuum heat insulating material having a thickness of about 6 mm is formed by sequentially laminating strip-shaped surface fasteners (binding bands) as described above, and laminating in a horizontal-vertical-horizontal-vertical-horizontal-vertical manner. What was done was used.
FIG. 4 shows an outer diameter of about 28.5 cmφ using Aeroflex (registered trademark), which is a conventional heat insulating material of FIG. 3 (a), and a thickness of about 6 mm of Example 1 of FIG. 3 (b). An experiment in which a vacuum insulation material of about 19.7 cmφ with a 1 cm thick Aeroflex (registered trademark) insulation material was applied to a cylindrical side wall and had the same insulation performance. It is a result.
4a, 4b, and 4c in the left column of FIG. 4 are a pressure-composition-temperature (PCT) curve when only a conventional heat insulating material Aeroflex (registered trademark) having a thickness of 6 cm is used, and a tank internal temperature when storing hydrogen 4 represents the time variation of the circulating water inlet / outlet temperature and the tank internal pressure, the tank internal temperature at the time of hydrogen release, the circulating water inlet / outlet temperature and the tank internal pressure, and FIGS. 4d, 4e and 4f in the right column in FIG. Pressure-composition-temperature (PCT) curve when the vacuum heat insulating material of Example 1 is adopted, tank internal temperature at the time of storing hydrogen, circulating water inlet / outlet temperature and tank pressure over time, tank internal temperature at the time of hydrogen release, circulation It represents the time change of water inlet / outlet temperature and tank pressure. In addition, the hydrogen flow rate at the time of occlusion / release of hydrogen, the temperature of circulating water, and the flow rate are performed on the same conditions. As can be seen by comparing the left and right figures, there is no particular difference in the storage and release of hydrogen. The recovery rate of alloy reaction heat when using a conventional thermal insulation material Aeroflex (registered trademark) with a thickness of 6 cm was 89.4% when storing hydrogen and 89.8% when releasing hydrogen. Although the recovery rate of the alloy reaction heat when the vacuum heat insulating material of Example 1 is adopted is 88.6% at the time of hydrogen occlusion and 89.1% at the time of hydrogen release, it seems that the recovery rate is only slightly decreased. It was confirmed experimentally that this is the range of measurement error and the recovery performance is almost equivalent. That is, it can be seen that the performance of the conventional heat insulating material having a thickness of 6 cm can be drawn out by the vacuum heat insulating material of Example 1 having a thickness of only 6 mm and the heat insulating material having a thickness of 1 cm used for makeup. Therefore, it has been confirmed that the vacuum heat insulating material of the present invention can significantly reduce the size of the hydrogen storage device without deteriorating the heat insulating performance.

(Example 2)
In Example 1 above, a core material in which strip-shaped surface fasteners are stacked in a lattice shape is used to increase the vacuum space. However, in Example 2, vacuum space is secured on both the front and back surfaces of a thin and flexible substrate. A flexible vacuum that uses a core material sheet with protruding microstructures to cover it, covers the core material sheet with a jacket material that has a gas barrier property, and seals the inside under reduced pressure to adhere to the curved wall Insulating material is realized. When the vacuum space corresponding to the required heat insulation performance is not so necessary, the vacuum heat insulating material of the second embodiment can be used.
FIG. 5 is a diagram illustrating a core material used in the vacuum heat insulating material of Example 2, the left diagram is a plan view and a cross-sectional view of the core material sheet, and the right diagram is an enlarged cross-sectional view of the core material sheet. It is a cross-sectional enlarged view. The core sheet is composed of a flexible base material provided with protruding microstructures for securing a space on both sides, and the core sheet thus configured has a gas barrier property. When the inside of the covering is covered with the covering material and the inside is decompressed and sealed, the covering material is supported by the protruding fine structure, so that even if the covering material is deformed, it contacts the substrate surface between adjacent protruding fine structures. Thus, a vacuum space is formed continuously at the base of the protruding microstructure, and a flexible vacuum heat insulating material that can be in close contact with the curved wall of the object to be insulated can be realized.
The shape of the protrusion-like microstructure is shown as a hook in FIG. 5, but the protrusion shape is not limited to this, and when the cover material is covered with a cover material and the inside is sealed under reduced pressure, the cover material is deformed in a concave shape. Also, it is only necessary that the concave deformation does not occur until the surface of the base material between adjacent projecting microstructures comes into contact, and a continuous vacuum space is formed at the base of the projecting microstructure. In addition, when the envelope material deformed in concave contact with the base material surface between adjacent projecting microstructures, heat insulation by a vacuum space cannot be realized in the contacted portion, so the thickness and strength of the jacket material to be adopted, What is necessary is just to adjust the height of a protruding fine structure, the space | interval of adjacent protruding fine structures, etc. so that it may not contact.

(Example 3)
In Example 3, in order to increase the vacuum space and improve the heat insulation performance, a core material is formed by laminating a plurality of core material sheets of Example 2 above, and this core material is a jacket material having gas barrier properties. This realizes a flexible vacuum heat insulating material that can be tightly sealed against a curved wall by sealing the inside of the cover under reduced pressure. However, in order to reduce the heat conduction by the core material itself and reduce the amount of the core material used, the core sheet has a plurality of spaces (holes) as shown in FIG. It is arranged so that the space (hole) of the material sheet is shifted. In the example shown in FIG. 6, the space (hole) of the second-layer core material sheet is arranged at a position shifted from the space (hole) of the first-layer core material sheet. If the same core material sheet as the layer is used, the spaces (holes) of the second core material sheet and the third core material sheet are shifted from each other. In the illustrated example, if the same core material sheet as the first layer is used for the odd layers and the same core material sheet as the second layer is used for the even layers, a multi-layer core material corresponding to the desired heat insulation performance can be configured. It is possible to realize a flexible vacuum heat insulating material that covers a core material with a jacket material having a gas barrier property and seals the inside under reduced pressure to be in close contact with a curved wall.
Further, in this Example 3 in which the core material sheet is overlapped and used as the core material, if the protruding fine structures disposed on both surfaces of the core material sheet are made into the male piece and the female piece of the hook-and-loop fastener, the core material sheet is obtained. When overlapping and laminating, it is possible to connect the overlapping core sheets by engaging the male and female pieces, or to peel off the core sheets once connected. Since the piece and the female piece are appropriately connected to each other, they can be prevented from being deformed and can be deformed according to the curved surface.

In Examples 1 to 3, if a packaging material for a vacuum pack capable of heat welding having a gas barrier property as a covering material and a degassing sealer are provided, it can be easily manufactured at low cost.
Moreover, it becomes a vacuum heat insulating material which can be used in a high temperature area | region by making the structural member of a core material, and a jacket material into the material which can respond to high temperature.

The present invention was developed for a hydrogen storage alloy tank that utilizes heat, but can be used in any field that requires a heat insulating material.
For example, demand is expected for consumer products such as refrigerators and air conditioners, and it can also be used for general industrial products that need to be kept warm. It can also be applied to the insulation of pipelines used in the automobile and construction industries. Furthermore, when heat insulation for a high-temperature object is necessary in a plant or the like, it can be applied by making each member compatible with high temperature, and the range of uses is very wide.

Claims (7)

A core sheet in which protruding microstructures for securing a vacuum space on both surfaces of a flexible substrate are disposed;
It consists of a gas barrier covering material covering the core sheet,
The protruding fine structure has a shape that allows the protruding fine structures of the core material sheets of layers adjacent to each other to be detachably engaged when the core material sheets are laminated,
A vacuum heat insulating material in which an inner space in which the core sheet is covered with the jacket material is sealed under reduced pressure. A core material sheet in which projecting microstructures for securing a vacuum space on both surfaces of a flexible base material are disposed, and a plurality of hole-like spaces are formed in the core material sheet,
A plurality of the core material sheets are laminated and arranged so that the hole-like spaces between the core material sheets of adjacent layers are shifted, and the protruding microstructures of the core material sheets are detachably engaged. A core material,
It consists of a gas barrier covering material covering the core material,
A vacuum heat insulating material in which an internal space in which the core material is covered with the jacket material is sealed under reduced pressure. The vacuum heat insulating material according to claim 1 or 2, wherein the protruding microstructures are a male piece and a female piece of a hook-and-loop fastener. A strip-shaped surface fastener in which male and female pieces of hook-and-loop fasteners are arranged on both sides of a flexible base material is layered in a lattice pattern,
A core material formed by stacking at least one layer of a belt-like surface fastener so as to cover the space portion of the lattice stacked in the lattice shape;
It consists of a gas barrier covering material covering the core material,
A vacuum heat insulating material in which an internal space in which the core material is covered with the jacket material is sealed under reduced pressure.   The vacuum heat insulating material according to claim 4, wherein the band-shaped surface fastener is a binding band. A core sheet in which projecting microstructures for securing a vacuum space are provided on both surfaces of a flexible base material, and a plurality of core sheets in which a plurality of hole-shaped spaces are formed Laminating and laminating and laminating so that the hole-shaped spaces between the core material sheets of the layers adjacent to each other are shifted , and constructing the core material by detachably engaging the protruding fine structures of the core material sheets with each other When,
Covering the core material with a gas barrier outer covering material;
A method for producing a vacuum heat insulating material, comprising: a step of sealing an inner space in which the core material is covered with a gas barrier outer covering material under reduced pressure. A belt-shaped surface fastener in which male and female surface fasteners are arranged on both surfaces of a flexible base material is overlapped in a lattice shape, and at least one belt-shaped surface fastener is further provided so as to cover a space portion of the lattice overlapped in the lattice shape. Building a core material by stacking more than one layer;
Covering the core material with a gas barrier outer covering material;
A method for producing a vacuum heat insulating material, comprising: a step of sealing an inner space in which the core material is covered with a gas barrier outer covering material under reduced pressure.

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