JP7233070B2 - vacuum insulation - Google Patents

Description

TECHNICAL FIELD The present invention relates to a vacuum heat insulating material in which a core member is vacuum-sealed with an outer wrapping material.

A vacuum heat insulating material is widely used in which a core member is vacuum-sealed with an outer wrapping material to improve heat insulating performance. Depending on the installation location of the vacuum heat insulating material, it may be desired to bend the vacuum heat insulating material. In order to cope with this problem, a vacuum heat insulating material has been proposed that includes a core portion in which non-stretchable portions and stretchable portions are alternately arranged, and an outer wrapping portion that wraps the core portion (see, for example, Patent Document 1). .

JP 2016-176491 A

The vacuum heat insulating material described in Patent Document 1 has a structure in which a core part containing glass wool as a main component is sealed with an outer wrapping material, so the core part cannot be made very thin in consideration of a decrease in heat insulation. . Therefore, although it can be bent in a predetermined direction depending on the shape and arrangement of the non-stretchable portion and the stretchable portion of the core portion, it is difficult to bend in other directions. Therefore, it cannot be molded into a desired three-dimensional shape.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the above-mentioned problems, and to provide a vacuum heat insulating material capable of being molded into a three-dimensional shape having sufficient heat insulating performance even if it is thin.

The vacuum insulation material of the present invention is
An inner layer composed of inorganic fiber sheets or laminated sheets in which inorganic fiber sheets and resin fiber sheets are alternately arranged, and an outer layer composed of resin fiber sheets disposed so as to be in contact with the upper and lower surfaces of the inner layer. a core member having
an outer packaging material obtained by sealing the core member under reduced pressure;
characterized by comprising

In the present invention, since the inorganic fiber sheet and the resin fiber sheet are in contact with each other, a plurality of very small air layers are present at the boundary, thereby providing sufficient heat insulating performance even if the sheet is thin. Further, by heating and thermally deforming the resin fiber sheet arranged as the outermost layer of the core member, molding into various three-dimensional shapes becomes possible. At this time, a difference in thermal expansion occurs between the inorganic fiber sheet and the resin fiber sheet due to heating, but since the fiber sheets are in contact with each other, the contact area is limited, and a plurality of minute air layers exist at the boundary. Therefore, damage due to the difference in thermal expansion can be suppressed.

As described above, according to the present invention, it is possible to provide a vacuum heat insulating material that can be molded into a three-dimensional shape and has sufficient heat insulating performance even if it is thin.

Further, the present invention is characterized in that the hardness of the resin fiber sheet is lower than the hardness of the inorganic fiber sheet.

In the present invention, since the hardness of the resin fiber sheet is lower than the hardness of the inorganic fiber sheet, the resin fiber sheet is deformed to a greater extent during evacuation during the production of the vacuum insulation material, and a large number of minute air layers are generated. Thereby, it is possible to effectively suppress damage due to a difference in thermal expansion while having excellent heat insulation performance.

Further, the present invention
The resin fiber sheet is characterized by being formed from olefin short fibers.

In the present invention, since the resin fiber sheet is formed from olefin short fibers, it is possible to realize a lightweight and highly reliable vacuum heat insulating material that can be easily molded into a three-dimensional shape. Furthermore, when the temperature is low, the thermal conductivity of the resin fiber sheet made of short olefin fibers is lowered, so that the heat insulating performance is further improved. Therefore, this vacuum heat insulating material can be used particularly suitably for refrigerators, freezers, cold storage containers, and the like.

Further, the present invention
It is characterized in that the fibers of the resin fiber sheet and the inorganic fiber sheet are oriented in substantially the same direction which is substantially perpendicular to the thickness direction of the sheets.

In the present invention, since the fibers of the resin fiber sheet and the inorganic fiber sheet are oriented in a direction substantially perpendicular to the thickness direction of the sheet, a so-called heat bridge, which is a thermal short circuit due to the fibers extending in the thickness direction, occurs. Because there is no heat loss, excellent thermal insulation performance is obtained. Furthermore, since the fibers of the resin fiber sheet and the inorganic fiber sheet are oriented in substantially the same direction, even if there is a difference in thermal expansion, the friction between the fibers of the resin fiber sheet and the inorganic fiber sheet is further reduced, resulting in damage. can be effectively suppressed.

Further, the present invention
The core member is arranged inside the joint portion of the outer wrapping material.

In the present invention, since the core member can be made thin, it is possible to put the core member in an envelope-shaped outer wrapping material and draw a vacuum. As a result, it is possible to realize a vacuum heat insulating material in which the core member is arranged inside the joint portion of the outer wrapping material without having the outer wrapping material. can.

As described above, according to the present invention, it is possible to provide a vacuum heat insulating material that has sufficient heat insulating performance even if it is thin and that can be molded into a three-dimensional shape.

BRIEF DESCRIPTION OF THE DRAWINGS It is side surface sectional drawing which shows typically the vacuum heat insulating material which concerns on the 1st Embodiment of this invention. FIG. 3 is a side cross-sectional view schematically showing a boundary region between an inorganic fiber sheet and a resin fiber sheet; FIG. 4 is a side cross-sectional view schematically showing a vacuum heat insulating material according to a second embodiment of the present invention; FIG. 4 is a perspective view schematically showing a case where a thick core member is put into an outer wrapping material having ears. FIG. 4 is a perspective view schematically showing a case where a thin core member is put in an envelope-shaped outer wrapping material. It is a figure (photograph) which shows the Example which provided the recessed part in the actually manufactured vacuum heat insulating material by bending. It is a figure (photograph) which shows the Example which performed shaping|molding of three-dimensional shape to the vacuum heat insulating material which actually manufactured.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. The embodiments described below are for embodying the technical idea of the present invention, and unless there is a specific description, the present invention is not limited to the following.
In each drawing, members having the same function may be given the same reference numerals. In some cases, the embodiments are shown separately for the sake of convenience in consideration of the explanation of the main points or the ease of understanding, but partial replacement or combination of the configurations shown in different embodiments is possible. In the embodiments to be described later, descriptions of matters common to the above-described embodiments will be omitted, and only different points will be described. In particular, similar actions and effects due to similar configurations will not be mentioned sequentially for each embodiment. The sizes and positional relationships of members shown in each drawing may be exaggerated for clarity of explanation.

(Vacuum insulation material according to the first embodiment of the present invention)
FIG. 1 is a side sectional view schematically showing a vacuum heat insulating material 2 according to a first embodiment of the invention.

Referring to FIG. 1, the vacuum heat insulating material 2 according to the first embodiment of the present invention is constructed by vacuum-sealing a core member 30 functioning as a heat insulating material with an outer wrapping material 40 . The outer wrapping material 40 is a film containing a resin layer.
The core member 30 has an inner layer 10 made of the inorganic fiber sheet 4 and an outer layer 20 made of the resin fiber sheets 6a and 6b arranged so as to be in contact with the upper surface 10a and the lower surface 10b of the inner layer 10. . There is no adhesive layer between the laminated inorganic fiber sheet 4 and resin fiber sheets 6a and 6b, and they are kept in close contact with each other by decompression.

<Inorganic fiber sheet>
In this embodiment, glass wool is used as the material of the inorganic fiber sheet 4, and a wet type is particularly preferable. As for the fiber diameter of the glass wool, if the fiber diameter is small, the space between the fibers increases and the porosity increases, so that the thermal conductivity can be reduced and the variation in basis weight of the fiber can be reduced. On the other hand, when the fiber diameter becomes small, the entanglement between the fibers becomes weak, and the strength decreases. Considering these factors comprehensively, the fiber diameter of the glass wool is preferably about 1 μm to 8 μm, more preferably about 3 μm to 5 μm.

As for the fiber length of the glass wool, if the fiber length is short, the variation in basis weight of the fiber can be reduced. On the other hand, if the fiber length of the glass wool is short, the fibers are less entangled with each other, resulting in a decrease in strength. Considering these factors comprehensively, the fiber length of the glass wool is preferably about 2 to 100 mm, more preferably about 3 mm to 50 mm.
If the fiber length is short, the fibers are oriented in the heat insulation direction, and there is a possibility that the heat insulation performance will deteriorate due to so-called heat bridging.

The material of the inorganic fiber sheet 4 is not limited to glass wool, and inorganic fibers such as glass fiber, alumina fiber, silica-alumina fiber, silica fiber, rock wool, and silicon carbide fiber can also be used.

<Resin fiber sheet>
Resin fibers are usually formed from thermoplastic resins. Among such thermoplastic resins, olefin resins represented by polypropylene and polyethylene are used in this embodiment. In particular, short olefinic fibers having a relatively short fiber length are preferred. Among them, it is more preferable to use a non-woven fabric made of polypropylene by the melt-blown method.

As for the resin fibers, if the fiber diameter is small, the space between the fibers increases and the porosity increases, so that the thermal conductivity can be reduced, and the variation in basis weight of the fibers can be reduced. On the other hand, when the fiber diameter becomes small, the entanglement between the fibers becomes weak, and the strength decreases. Considering these factors comprehensively, the fiber diameter of the resin fiber is preferably about 1 μm to 8 μm, more preferably about 3 μm to 5 μm.

As for the fiber length of the resin fiber, if the fiber length is short, the variation in basis weight of the fiber can be reduced. On the other hand, if the fiber length of the resin fiber is short, the entanglement between the fibers is small, resulting in a decrease in strength. Considering these factors comprehensively, the fiber length of the resin fiber is preferably about 2 to 100 mm, more preferably about 3 mm to 50 mm.
If the fiber length is short, the fibers are oriented in the heat insulation direction, and there is a possibility that the heat insulation performance will deteriorate due to so-called heat bridging.

The material of the resin fiber sheet 6 is not limited to the case of using olefin resin fibers, and any other thermoplastic resin fibers such as nylon, polyester, acrylic, vinylon, and polyurethane can be used.

<Outer packaging material>
As the outer wrapping material 40 according to this embodiment, a gas barrier film having a four-layer structure as shown below is used. Explaining in order from the outermost layer to the innermost layer, nylon, polyethylene terephthalate resin, etc. functioning as a surface protective layer are arranged in the outermost layer. Next, as a first intermediate layer, an aluminum deposited PET (polyethylene terephthalate) functioning as a gas barrier layer is arranged. Next, an aluminum foil is arranged as a second intermediate layer. As the innermost layer, a high-density polyethylene that functions as a sealing layer is arranged.

The outer wrapping material 40 is not limited to the case of using the gas barrier film having the four-layer structure described above. It is also possible to use an ethylene-vinyl alcohol copolymer resin, a gas barrier film made of a high-density polyethylene resin, or the like.
The thickness of the outer wrapping material 40 can be exemplified from 15 μm to 200 μm.

<Heat insulation performance>
In the vacuum insulation material, the core member is sealed inside the outer packaging material in a decompressed state. have a great effect on the thermal insulation performance of

FIG. 2 is a side cross-sectional view schematically showing a boundary region between the inorganic fiber sheet 4 and the resin fiber sheet 6. As shown in FIG. As shown in FIG. 2, in the vacuum heat insulating material 2 according to this embodiment, the inorganic fiber sheet 4 and the resin fiber sheet 6 are in contact at the boundary between the inner layer 10 and the outer layer 20 of the core member 30, so arrow A As indicated by , there are a plurality of minute air layers. Since the air layer has high heat insulating properties, the vacuum heat insulating material 2 according to the present embodiment can have sufficient heat insulating properties even if it is thin.

<Thermal deformation performance>
Since the outer wrapping material is a film having a resin layer as described above, it thermally expands and extends when heated. If the core member does not have an outer layer made of a resin fiber sheet, and the core member made of inorganic fibers and the outer wrapping material are in direct contact with each other, the outer wrapping material will be deformed when heated to thermally deform the vacuum heat insulating material. The material expands due to thermal expansion, but the core member made of inorganic fibers does not thermally expand so much, so a difference in thermal expansion occurs at the boundary between the core member and the outer wrapping material.
At this time, since the outer wrapping material containing the resin film is in close contact with the outer surface of the core member due to the reduced pressure, a large frictional force is generated between the outer wrapping material and the core member, which may cause damage at the boundary.

On the other hand, in the present embodiment, the outer layer 20 composed of the resin fiber sheets 6a and 6b is present between the inner layer 10 composed of the inorganic fiber sheet 4 and the outer wrapping material 40. As shown in FIG. If the vacuum heat insulating material 2 is heated to thermally deform it, the outer layer 20, which is the resin fiber sheet 6, thermally expands following the outer wrapping material 40 containing the resin film. On the other hand, at the boundary between the inner layer 10 and the outer layer 20 of the core member 30, the inner layer 10, which is the inorganic fiber sheet 4, is less thermally expanded than the outer layer 20, and the boundary between the inner layer 10 and the outer layer 20 A difference in thermal expansion occurs between the
However, at the boundary between the inner layer 10 and the outer layer 20, the contact portion is limited because the inorganic fiber sheet 4 and the resin fiber sheet 6 are in contact with each other. Since it exists, the frictional force is small, and it is possible to suppress damage due to the difference in thermal expansion by slipping over each other. As described above, there is no adhesive layer at the boundary between the inner layer 10 and the outer layer 20, so that it does not restrict sliding between the fibrous sheets.

Therefore, by heating the vacuum heat insulating material 2 according to the present embodiment and thermally deforming the resin fiber sheets 6a and 6b arranged in the outermost layer of the core member 30, molding into various three-dimensional shapes becomes possible. .
As described above, according to the present embodiment, it is possible to provide the vacuum heat insulating material 2 that can be molded into a three-dimensional shape and has sufficient heat insulating performance even if it is thin. As a result, the design-free vacuum heat insulating material 2 can be realized, leading to expansion of the vacuum heat insulating material market.

Furthermore, it is preferable that the hardness of the resin fiber sheet 6 is lower than the hardness of the inorganic fiber sheet 4 . When the hardness of the resin fiber sheet 6 is lower than that of the inorganic fiber sheet 4, when the core member 30 is placed in the outer wrapping material 40 and vacuumed, the inorganic fiber sheet 4 does not deform much, but the resin fiber sheet does not deform. 6 deforms more than that. For this reason, a large number of minute spaces are generated between the inorganic fiber sheet 4 and the resin fiber sheet 6 (see arrow A in FIG. 2), and therefore a large number of minute air layers can be formed. Since this air layer works as a heat insulating layer, the vacuum heat insulating material 2 can have excellent heat insulating performance even if it is thin. In addition, since the contact portion is further limited by the air layer at the boundary between the inner layer 10 and the outer layer 20, damage caused by the difference in thermal expansion between the inorganic fiber sheet 4 and the resin fiber sheet 6 can be effectively prevented. can be suppressed.

As shown in FIG. 2, in this embodiment, the fibers f6 of the resin fiber sheet 6 and the fibers f4 of the inorganic fiber sheet 4 are oriented in a direction substantially perpendicular to the sheet thickness direction. As a result, even if the length of the fibers is short, it is possible to suppress the occurrence of so-called heat bridges, which are thermal short circuits caused by the fibers extending in the thickness direction, so that excellent heat insulation performance can be obtained.
Furthermore, since the fibers f6 of the resin fiber sheet 6 and the fibers f4 of the inorganic fiber sheet 4 are oriented in substantially the same direction, even if there is a difference in thermal expansion, it becomes easier to slide in the longitudinal direction of the fibers, and the inner layer 10 and the inner layer 10 are more likely to slide. The frictional force generated at the boundary with the outer layer 20 is further reduced, and damage can be more effectively suppressed.

However, the present invention is not limited to this, and the fibers f6 and f4 of the resin fiber sheet 6 and the inorganic fiber sheet 4 are oriented in a direction substantially perpendicular to the thickness direction of the sheets, but in plan view, the resin The fibers f6 and f4 of the fiber sheet 6 and the inorganic fiber sheet 4 may be arranged at a predetermined angle. In addition, although the fibers f6 and f4 of the resin fiber sheet 6 and the inorganic fiber sheet 4 are oriented in a direction substantially perpendicular to the sheet thickness direction, the fibers f6 of the resin fiber sheet 6 and the inorganic fiber sheet 4 are oriented in a plan view. , f4 may be randomly oriented. In these cases, it can be expected that more air layers are provided between the resin fiber sheet 6 and the inorganic fiber sheet 4 .

As described above, in this embodiment, the resin fiber sheet 6 is made of short olefin fibers. Olefin-based resins are excellent in heat resistance, cold resistance, and weather resistance, and are lightweight and recyclable, so that manufacturing costs can be reduced. As a result, it is possible to realize a lightweight and highly reliable vacuum insulation material that can be easily molded into a three-dimensional shape.

Furthermore, it is noteworthy that when the temperature is low, the thermal conductivity of the resin fiber sheet 6 made of short olefinic fibers is lowered, and the heat insulation performance is further enhanced. Therefore, the vacuum heat insulating material 2 according to this embodiment is particularly suitable for use in refrigerators, freezers, cold storage containers, and the like.

(Vacuum insulation material according to the second embodiment of the present invention)
FIG. 3 is a side sectional view schematically showing a vacuum heat insulating material 2 according to a second embodiment of the invention.
In the above-described first embodiment, the internal layer 10 is composed of one inorganic fiber sheet 4, but in this embodiment, the internal layer 10 is composed of an inorganic fiber sheet 4a, a resin fiber sheet 6c, and a It is different in that it is composed of three layers of laminated sheets 8 alternately arranged in the order of the inorganic fiber sheets 4b. Similar to the above first embodiment, the upper and lower surfaces 10a and 10b of the inner layer 10 are in contact with the resin fiber sheets 6a and 6b, respectively. There is no adhesive layer between the laminated inorganic fiber sheets 4a, 4b and the resin fiber sheets 6a, 6b, 6c, and they are kept in close contact with each other by decompression.

Thus, when the inner layer 10 is composed of the laminated sheet 8 in which the inorganic fiber sheet 4a, the resin fiber sheet 6c, and the inorganic fiber sheet 4b are alternately arranged, the inorganic fiber sheets 4a and 4b and the resin fiber sheet Since a plurality of minute air layers are also formed between 6c, the heat insulating performance is further enhanced.
Also, at the boundary between the inorganic fiber sheets 4a and 4b and the resin fiber sheet 6c in the internal layer 10, the contact area is limited because the fiber sheets are in contact with each other, and furthermore, there are a plurality of minute air layers at the boundary. exists, so damage due to the difference in thermal expansion can be suppressed.
Furthermore, when the internal layer 10 is composed of the laminated sheet 8, in addition to the resin fiber sheets 6a and 6b constituting the external layer 20, the resin fiber sheet 6c constituting the laminated sheet 8 of the internal layer 10 is thermally deformed. By increasing the strength of the three-dimensional shape, the strength of the three-dimensional shape can be increased.

In this embodiment, the laminate sheet 8 is composed of three layers in which the inorganic fiber sheets 4a and 4b and the resin fiber sheet 6c are alternately arranged. and resin fiber sheets can be alternately laminated to form an arbitrary number of laminated sheets. Moreover, the outermost layer of the inner layer 10 that is in contact with the resin fiber sheets 6a and 6b constituting the outer layer 20 does not necessarily have to be an inorganic fiber sheet, and may be a resin fiber sheet. In other words, the resin fiber sheets may come into contact with each other at the boundary between the inner layer 10 and the outer layer 20 .
Other points are the same as those of the above-described first embodiment, so further description is omitted.

In the vacuum heat insulating materials 2 according to the first and second embodiments described above, the following can be exemplified as the dimensions of each member before pressure reduction. The thickness of the inner layer 10 can be exemplified from about 1 mm to 8 mm, and the thickness of the outer layer 20 (total thickness of the upper and lower resin fiber sheets 6) can be exemplified from about 2 mm to 5 mm. Therefore, the thickness dimension of the core member 30 is about 3 mm to 20 mm. Since the thickness of the outer wrapping material 40 is 200 μm or less, the thickness of the vacuum heat insulating material 2 in which the core member 30 is decompressed and sealed in the outer wrapping material 40 is about 1 mm to 15 mm.
As described above, the vacuum heat insulating material 2 according to the present embodiment is extremely thin, so that it can be thermally deformed into a desired shape according to the application, as will be described later.

(Manufacturing method of vacuum insulation material)
In a general method for manufacturing a vacuum insulation material, a sheet formed from a film having gas shielding properties is prepared, and three sides of the sheet are heat-sealed leaving an opening to form a bag-like outer wrapping material. do. Then, the core member is put into the outer wrapping material through the opening and vacuumed, and the opening portion is heat-sealed so that the core member is decompressed and sealed by the outer wrapping material.

FIG. 4 is a perspective view schematically showing a case where a thick core member 130 is inserted into an outer wrapping material 140 having ears B as indicated by an arrow B. FIG. FIG. 5 is a perspective view schematically showing a case where the thin core member 30 is put in the envelope-shaped outer wrapping material 40. As shown in FIG.

As shown in FIG. 4, the core member 130 of the conventional vacuum heat insulating material 102 has a predetermined thickness in order to obtain heat insulating performance. Therefore, in order to secure a space into which the core member 130 can be inserted, it is necessary to use the outer packaging material 140 having ears B of a predetermined size with three sides excluding one side serving as an opening portion being heat-sealed. In this case, when the opening is heat-sealed by drawing a vacuum, the ear portion B, which is not filled with the core member 130, becomes a surplus portion. For this reason, when the vacuum heat insulating material 102 is installed at the heat insulating location, the edge folding operation of the edge portion B occurs, and there is a possibility that the outer wrapping material 140 may be damaged during the edge folding operation.

On the other hand, as shown in FIG. 5, in the vacuum heat insulating material 2 according to the embodiment of the present invention, since the core member 30 is thin, an envelope-shaped outer wrapping material 40 without ears can be used. That is, a gas-shielding sheet is folded, and as shown by arrow C in FIG. A shaped outer wrapping material 40 is formed. Then, the vacuum heat insulating material 2 can be manufactured by inserting the core member 30 into the envelope-shaped outer packaging material 40 through the opening, vacuuming the same, and heat-sealing the opening portion. In this case, no selvage is formed, and there is no problem of edge folding work or breakage during the edge folding work.

As described above, in the vacuum heat insulating material 2 according to the embodiment of the present invention, the core member 30 can be made thin, so that the core member 30 can be hermetically sealed in the envelope-shaped outer wrapping material 40 . That is, in the vacuum heat insulating material 2 according to this embodiment, the core member 30 is arranged inside the joint portion C of the outer wrapping material 40 . Therefore, no selvages are generated, and problems such as edge folding work and breakage during the edge folding work do not occur.
However, also in the vacuum heat insulating material 2 according to the embodiment of the present invention, it is possible to use the outer wrapping material 140 having the ears B with three sides heat-sealed. In this case, since the core member can be thinned, the width of the ear portion can be narrowed.

(Other embodiments)
In the vacuum heat insulating material 2 according to the first and second embodiments described above, two resin fiber sheets 6a and 6b are arranged in contact with the upper and lower surfaces 10a and 10b of the inner layer 10 . However, in addition to the case where different sheets 6a and 6b are arranged above and below the internal layer 10, a single sheet may be used to cover the upper and lower surfaces and side surfaces of the internal layer 10. . In that case, one sheet may cover only one side surface or may cover both side surfaces (that is, cover the entire surface of the inner layer 10).

The vacuum heat insulating material 2 according to the embodiment of the present invention can be molded into a desired shape according to the installation location. can be enhanced. In particular, when the vacuum heat insulating material 2 is installed near the evaporator of a refrigerator, the vacuum heat insulating material 2 is preformed according to the uneven shape of ribs or the like, thereby increasing the volumetric efficiency and the work efficiency of installing the vacuum heat insulating material 2. and reduce the risk of breakage during work.

The vacuum insulation material 2 according to the above embodiment is applied not only to refrigerators, but also to cold insulation boxes, construction panels, cold insulation containers for medical equipment, vending machines, showcases, heat insulation helmets, heat insulation lunch boxes, and water heaters. It can be suitably applied to various devices including the above.

Next, a description will be given of a test conducted by actually manufacturing the vacuum heat insulating material according to the second embodiment.
The specifications of the manufactured vacuum insulation material are as follows.
(1) Core member (a) Inner layer: three-layer laminated sheet alternately arranged in the order of inorganic fiber sheet, resin fiber sheet, and inorganic fiber sheet (b) Outer layer: so as to be in contact with the upper and lower surfaces of the inner layer Arranged resin fiber sheet (c) inorganic fiber sheet: glass wool
Manufacturer_CHANGHAI CHANGZHOU CHINA
Product number_S-VIP120
Average thickness 1.09mm 120g/m2
(c) Resin fiber sheet: Olefin
Manufacturer_Japan Vilene
Product number_OF-13042 (T-1Z)
Average thickness 1.5mm 75g/m2
(2) Outer packaging material Film configuration
Manufacturer_J Film
Specifications_ONY15μ/VMPET12μ/AL7μ/LLDPE50μ

(Test 1)
First, based on JIS A 1412-1, the thermal conductivity of the vacuum insulation material was measured. At this time, two specimens (No. 1 and No. 2) were used for the measurement.
(1) Specimen specifications (a) Dimensions (No. 1) 305 mm × 317 mm, thickness 4.7 mm
(No. 2) 304mm x 302mm, thickness 4.8mm
(b) Weight (No. 1) 97.90g
(No.2) 97.28g

[Test results]

As described above, in the vacuum heat insulating material according to the present embodiment, the thermal conductivity is 0.0054 W/(mK) when the average temperature _θm is 0°C, and the thermal conductivity when the average temperature _θm is 23°C. It has a conductivity of 0.0067 W/(m·K). Therefore, it was demonstrated that the vacuum heat insulating material has a high heat insulating performance in spite of its extremely thin average thickness of 4.75 mm. It was also demonstrated that when the average temperature _θm is 0°C, the heat insulation performance is improved by 24% compared to when the average temperature _θm is 23°C. In other words, it was demonstrated that the heat insulating performance of the vacuum heat insulating material is temperature dependent, and that the lower the temperature, the higher the heat insulating performance.

(Test 2)
Next, the rate of improvement in heat insulation performance was measured when the vacuum heat insulating material according to the present embodiment was added to a cooler box using a conventional vacuum heat insulating material or urethane foam material.

[Test results]

As described above, it was demonstrated that the heat insulating performance was improved by 14% by adding the vacuum heat insulating material according to the above example to a cooler box equipped with a conventional vacuum heat insulating material. It was also demonstrated that the addition of the vacuum heat insulating material according to the above example improved the heat insulation performance of a cooler box made of urethane material, which is thick but has high heat insulation performance, by 7%. In any case, the improvement of the heat insulating performance by the vacuum heat insulating material according to the above examples was demonstrated.

(Test 3)
Next, a test was conducted in which the actually manufactured vacuum insulation material was subjected to bending and three-dimensional molding. FIG. 6 is a diagram (photograph) showing an example in which concave portions are provided in an actually manufactured vacuum heat insulating material by bending. FIG. 7 is a diagram (photograph) showing an example in which an actually manufactured vacuum heat insulating material was molded into a three-dimensional shape.

As shown in FIG. 6, the central portion of the vacuum heat insulating material is provided with a recess without wrinkles. In addition, (a) of FIG. 7 is a perspective view of a molded product obtained by molding a vacuum heat insulating material into a three-dimensional shape, (b) is a top view of the molded product shown in (a), and (c ) is a bottom view of the molded product shown in (a). As is clear from FIG. 7, it was demonstrated that a design-free vacuum insulation material that can be molded into a three-dimensional shape can be realized.

As described above, the vacuum heat insulating material 2 according to the embodiment of the present invention has an inner layer 10 composed of the laminated sheet 8 in which the inorganic fiber sheet 4 or the inorganic fiber sheet 4 and the resin fiber sheet 6 are alternately arranged, and It comprises a core member 30 having an outer layer 20 composed of a resin fiber sheet 6 arranged so as to be in contact with the upper surface 10a and the lower surface 10b of the inner layer 10, and an outer packaging material 40 in which the core member 30 is vacuum-sealed. Therefore, even if it is thin, it has sufficient heat insulating performance and can be molded into a three-dimensional shape. In particular, it is preferable that the hardness of the resin fiber sheet 6 is lower than the hardness of the inorganic fiber sheet 4 . As a result, a large number of very small air layers can be formed between the inorganic fiber sheet 4 and the resin fiber sheet 6, so that even if the core member 30 is thin, excellent heat insulation performance can be achieved, and the inorganic fiber sheet can be heated. Damage due to the difference in thermal expansion between 4 and resin fiber sheet 6 can be effectively suppressed.

Although embodiments and embodiments of the present invention have been described, the disclosure may vary in details of construction, and changes in the combination and order of elements in the embodiments and embodiments, etc., will not affect the claimed invention. without departing from the scope and spirit of

2 Vacuum insulation materials 4, 4a, b Inorganic fiber sheets 6, 6a-c Resin fiber sheet 8 Laminated sheet 10 Internal layer 10a Upper surface 10b Lower surface 20 External layer 30 Core member 40 Outer wrapping material 102 Vacuum insulating material 130 Core member 140 Outer wrapping material f4 , f6 fiber

Claims (5)

An inner layer composed of inorganic fiber sheets or laminated sheets in which inorganic fiber sheets and resin fiber sheets are alternately arranged, and an outer layer composed of resin fiber sheets disposed so as to be in contact with the upper and lower surfaces of the inner layer. a core member having
an outer packaging material for vacuum-sealing the core member;
with
The fibers of the resin fiber sheet and the inorganic fiber sheet are oriented in a direction substantially perpendicular to the thickness direction of the sheet,
The hardness of the resin fiber sheet is lower than the hardness of the inorganic fiber sheet,
A vacuum insulation characterized in that a minute air layer due to a difference in deformation during vacuuming exists between the resin fiber sheet arranged as the outermost layer of the core member and the inorganic fiber sheet adjacent to the inner side thereof. material.
2. The vacuum heat insulating material according to claim 1, wherein the resin fiber sheet arranged as the outermost layer of the core member is thermally deformed by heating to be molded into a three-dimensional shape.
3. The vacuum heat insulating material according to claim 1, wherein the inorganic fibers have a fiber length of 2 to 100 mm, and the resin fibers have a fiber length of 2 to 100 mm .
4. The vacuum heat insulating material according to any one of claims 1 to 3, wherein the resin fiber sheet is made of short olefin fibers.
The vacuum heat insulating material according to any one of claims 1 to 4, wherein the core member is arranged inside the joint portion of the outer wrapping material.

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