Outer packaging material for vacuum heat-insulating material, vacuum heat-insulating material, article with vacuum heat-insulating material, and method for producing outer packaging material for vacuum heat-insulating material

Abstract

The present disclosure provides an outer packaging material for a vacuum heat-insulating material, the outer packaging material having a water vapor permeability of 0.1 g / (m2·day) or less and an oxygen permeability of 0.1 cc / (m2·day·atm) or less. The outer packaging material for a vacuum heat-insulating material has a plane-direction thermal diffusivity α and a thickness T which satisfy the following (expression 1). Expression 1: α≤6.375×10-5 / (T×V) (In the expression, α is the plane-direction thermal diffusivity (m2 / s) of the outer packaging material for a vacuum heat-insulating material, T is the thickness (m) of the outer packaging material for a vacuum heat-insulating material, and V is the volumetric specific heat of the outer packaging material for a vacuum heat-insulating material and is 2.2×106 J / (m3·K) to 2.4×106 J / (m3·K).)

Description

Outer packaging material for vacuum insulation material, vacuum insulation material, article with vacuum insulation material, and method for manufacturing outer packaging material for vacuum insulation material

[0001] The present disclosure relates to a vacuum insulation outer packaging material capable of forming a vacuum insulation material, a vacuum insulation material, an article with vacuum insulation material, and a method for manufacturing a vacuum insulation outer packaging material.

[0002] In recent years, vacuum insulation materials have been used to reduce the energy consumption of products. Vacuum insulation materials are components in which a core material is disposed within a bag of an outer packaging material, and the inside of the bag is maintained in a vacuum state where the pressure is lower than atmospheric pressure. This suppresses internal thermal convection, thereby enabling the material to exhibit good thermal insulation performance. The outer packaging material used for vacuum insulation materials will be referred to as an outer packaging material for vacuum insulation materials, or simply as an outer packaging material.

[0003] For example, in refrigerators, shipping containers, etc., an insulating box is provided to cover the periphery of the storage space to insulate it from the surroundings. Lightweight and thin insulating materials are required for the insulating materials used in insulating boxes, etc. This is expected to reduce the weight of the insulating box and increase its internal volume. Vacuum insulation materials are thin and have high insulating performance, so they are ideally used as insulating materials for insulating boxes.

[0004] Patent Documents 1 to 3 disclose techniques for forming a honeycomb structure or hollow spaces in the heat insulating member in order to reduce the weight of the heat insulating box.

[0005] JP 2015-014326 A JP 2017-155892 A JP 2013-189996 A

[0006] In the above Patent Documents 1 to 3, the weight of the insulating material is reduced by changing the materials surrounding the vacuum insulating material, but this cannot be adopted when it is not necessary for the structure of the insulating box. Therefore, there is a need to reduce the weight of the vacuum insulating material itself while maintaining high insulating performance.

[0007] The present disclosure is an invention made in consideration of the above circumstances, and its main object is to provide an outer packaging material for vacuum insulation material that can reduce the weight of the vacuum insulation material while maintaining the insulating performance of the vacuum insulation material.

[0008] One embodiment of the present disclosure is an outer packaging material for a vacuum insulation material,２ · day) or less, and the oxygen permeability is 0.1 cc / (m ２ The present invention provides an outer packaging material for a vacuum heat insulating material, wherein the thermal diffusivity α in the surface direction of the outer packaging material for a vacuum heat insulating material and the thickness T satisfy the following (Equation 1): α≦6.375×10 －５ / (T × V) (Equation 1) (wherein α is the thermal diffusivity (m ２ / s), T is the thickness (m) of the outer packaging material for vacuum insulation panels, V is the volumetric specific heat of the outer packaging material for vacuum insulation panels, and ６ J / (m ３ ・K) or more 2.4×10 ６ J / (m ３ ・K) or less.

[0009] Another embodiment of the present disclosure provides a vacuum insulation material having a core material and an outer packaging material in which the core material is enclosed, wherein the outer packaging material is the outer packaging material for a vacuum insulation material described above.

[0010] Another embodiment of the present disclosure provides an article with vacuum insulation comprising an article having a thermal insulation region and a vacuum insulation material, wherein the vacuum insulation material has a core material and an outer packaging material in which the core material is enclosed, and the outer packaging material is the outer packaging material for the vacuum insulation material described above.

[0011] Another embodiment of the present disclosure is a method for producing an outer packaging material for a vacuum insulation material, the outer packaging material having one or more gas barrier films and a heat-sealable layer, wherein the outer packaging material for a vacuum insulation material has a water vapor permeability of 0.1 g / (m ２ · day) or less, and the oxygen permeability is 0.1 cc / (m ２ The present invention also provides a method for producing an outer packaging material for a vacuum insulation material, which comprises selecting and laminating at least one or more gas barrier films and the heat-sealable layer so that the thermal diffusivity α in the plane direction of the outer packaging material for a vacuum insulation material and the thickness T satisfy the following (Equation 1): α≦6.375×10 －５ / (T × V) (Equation 1) (wherein α is the thermal diffusivity (m ２ / s), T is the thickness (m) of the outer packaging material for vacuum insulation panels, V is the volumetric specific heat of the outer packaging material for vacuum insulation panels, and ６ J / (m ３ ・K) or more 2.4×10 ６ J / (m ３ ・K) or less.

[0012] According to the present disclosure, it is possible to provide an outer packaging material for a vacuum insulation material that can reduce the weight of the vacuum insulation material while maintaining the insulating performance of the vacuum insulation material.

[0013] Fig. 1 is a schematic cross-sectional view showing an example of an outer packaging material for a vacuum insulation material according to the present disclosure. Fig. 2 is a schematic cross-sectional view showing another example of an outer packaging material for a vacuum insulation material according to the present disclosure. Fig. 3 is a schematic perspective view and cross-sectional view showing an example of a vacuum insulation material according to the present disclosure. Fig. 4 is a model of a vacuum insulation material for determining the effective thermal conductivity of the entire vacuum insulation material. Fig. 5 is a schematic cross-sectional view showing an example of an outer packaging material for a vacuum insulation material according to the present disclosure. Fig. 6 is a schematic cross-sectional view showing an example of an outer packaging material for a vacuum insulation material according to the present disclosure.

[0014] The present disclosure includes embodiments of an outer packaging material for vacuum insulation materials, a vacuum insulation material, and an article with vacuum insulation material. Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. However, the present disclosure can be implemented in many different embodiments, and should not be construed as being limited to the description of the embodiments exemplified below. Furthermore, to clarify the explanation, the drawings may schematically depict the width, thickness, shape, etc. of each part compared to the embodiments, but these are merely examples and do not limit the interpretation of the present disclosure. Furthermore, in this specification and each figure, elements similar to those described above with reference to the previous figures are given the same reference numerals, and detailed explanations may be omitted as appropriate. Furthermore, for convenience of explanation, the terms "upper" and "lower" may be used in some cases, but the up-down direction may be reversed.

[0015] Furthermore, in this specification, when a certain component, region, or other structure is said to be "above (or below)" another component, region, or other structure, unless otherwise specified, this includes not only the case where it is directly above (or below) the other structure, but also the case where it is above (or below) the other structure, i.e., the case where another component is included between the two above (or below) the other structure.

[0016] As described above, there is a need for an outer packaging material for vacuum insulation that can reduce the weight of vacuum insulation. When investigating the physical properties of an outer packaging material that can reduce the weight of vacuum insulation while maintaining the insulating performance of the vacuum insulation, the inventors of the present application adopted "V08621B (manufactured by Avery Dennison Hanita)," which is the most commonly used outer packaging material for vacuum insulation, as a reference film. Then, a vacuum insulation material in which a core material is enclosed in this reference film (outer packaging material) was used as the reference vacuum insulation material (reference vacuum insulation material).

[0017] The inventors of the present application investigated the physical properties of outer packaging materials so that, when producing a vacuum insulation material using the same type of core material as that used in the standard vacuum insulation material, a vacuum insulation material with the same thermal insulation performance as the standard vacuum insulation material can be obtained even if the weight of the core material is reduced by 10% or more. Note that V08621B has, in the thickness direction, a first aluminum-vapor-deposited PET film (12 μm), a second aluminum-vapor-deposited PET film (12 μm), a third aluminum-vapor-deposited PET film (12 μm), and a heat-sealable layer (50 μm), in this order. The aluminum-vapor-deposited PET film is a film in which a metal aluminum layer is vapor-deposited on one side of a PET film. The physical properties (measured values) of V08621B are as follows. The measurement methods for each property are described below. However, in the method for measuring thermal diffusivity α, the frequency of the heating light is 0.25 Hz.

[0018] <Physical properties of V08621B (measured values)> Thermal diffusivity in the surface direction α: 4.6 × 10 －７ m ２ / s Specific heat capacity S: 2.08 x 10 ３ J / (kg・K) ・Density D: 1.09×10 ３ kg / m ３ Water vapor permeability: 0.0072 g / (m ２ ・day) ・Oxygen permeability: 0.06cc / (m ２ ・day・ATM)

[0019] Next, the volumetric specific heat V and thermal conductivity X of the reference film were calculated using the following (Equation 2) and (Equation 3), respectively. Volumetric specific heat V [J / (m ３·K)] = specific heat capacity S [J / (kg ·K)] × density D [kg / m ３ ] (Equation 2) Thermal conductivity X [W / (m K)] = volumetric specific heat V [J / (m ３ ・K)]×thermal diffusivity α[m ２ / s] (Formula 3)

[0020] <Physical properties of V08621B (calculated values)> Volume specific heat V: 2.26 x 10 ６ J / (m ３ · K) Thermal conductivity X: 1.04 W / (m · K)

[0021] When viewed from the thickness direction, the center of the vacuum insulation material has extremely low thermal conductivity because the porous core material is sealed under reduced pressure. On the other hand, at the edges of the vacuum insulation material, heat is trapped by the outer packaging material, creating a thermal bridge. This increases the effective thermal conductivity of the vacuum insulation material as a whole.

[0022] Generally, when two structures (structure A and structure B) having the same thickness t but different areas and thermal conductivities when observed from the thickness direction are arranged in parallel, the thermal conductivity of the entire structure can be expressed as follows: 1 / R ｔｏｔａｌ = 1 / R Ａ +1 / R Ｂ = λ Ａ S Ａ / t+λ Ｂ S Ｂ / t = (λ Ａ S Ａ +λ Ｂ S Ｂ ) / t λ ｔｏｔａｌ = t / R ｔｏｔａｌ S ｔｏｔａｌ = (λ Ａ S Ａ +λ Ｂ S Ｂ ) / S ｔｏｔａｌ (In the formula, R ｔｏｔａｌ is the thermal resistance of the entire structure (K / W), R Ａ is the thermal resistance of structure A (K / W), R Ｂ is the thermal resistance (K / W) of structure B. t is the thickness (m) of structure A and structure B. S Ａ is the area (m ) when observed from the thickness direction of structure A ２ ), S Ｂis the area (m ) when observed from the thickness direction of structure B ２ ), S ｔｏｔａｌ is the area (m ) of the entire structure including Structure A and Structure B when observed from the thickness direction. ２ ) λ ｔｏｔａｌ is the thermal conductivity (W / (m·K)) of the entire structure including Structure A and Structure B.

[0023] The inventors of the present application have newly discovered that, as shown in Figure 4, if the decompressed core region (center) and outer packaging region (edge) of a vacuum insulation material are considered to have two structures with different areas and thermal conductivities when observed from the thickness direction, as described above, the effective thermal conductivity of the entire vacuum insulation material can be calculated using the following formula: λ ｅｆｆ = {(λ ｃｏｐ × (L １ −T×2)×(L ２ -T×2)+X×(T×p)) / (L １ ×L ２ ) = {(λ ｃｏｐ × (L １ ×L ２ -2 (L １ +L ２ ) x T + 4 x T ２ )+X×(T×p)} / (L １ ×L ２ ) (where λ ｃｏｐ is the thermal conductivity (W / (m·K)) of the center of the vacuum insulation material when the vacuum insulation material is observed in the thickness direction, which is the insulating direction. X is the thermal conductivity (W / (m·K)) of the outer packaging material. T is the thickness (m) of the outer packaging material. p is the perimeter (m) of the vacuum insulation material when the vacuum insulation material is observed in the thickness direction. L １ is the vertical length (m) when observed from the thickness direction of the vacuum insulation material, L ２ is the horizontal length (m) when observed from the thickness direction of the vacuum insulation material.

[0024] In this disclosure, λ ｃｏｐ = 0.002 W / (m·K), the horizontal length and vertical length are each 0.5 m (i.e., p = 2 m, L １ ×L ２ = 0.25 m ２ ) vacuum insulation material is assumed. Here, λ ｃｏｐThe factor of T multiplied by is T = 5.0 × 10 －５ ~5.0 x 10 －４ m (50 μm to 500 μm), as shown below, １ ×L ２ is less than 1% of L, which is small enough to be ignored. １ ×L ２ = 0.25 m ２ 2 x (L １ +L ２ )×T=0.0001~0.001m ２ 4 x T ２ = 1.0 × 10 ―８ ~4.0 x 10 ―６ m ２

[0025] Therefore, the effective thermal conductivity λ considering the thermal bridge at the end of the vacuum insulation material ｅｆｆ can be calculated using the following formula (4): ｅｆｆ = λ ｃｏｐ +X×T×p÷A (Formula 4) (In the formula, λ ｃｏｐ , X, T, and p are as described above. A is the area (m ２ )

[0026] The thermal conductivity of the reference film (outer packaging material) was X = 1.04 W / (m K), and the thickness T = 9.50 × 10 －５ m, the perimeter of the vacuum insulation material p = 2 m and the area of ​​the vacuum insulation material A = 0.25 m ２ By substituting into the above (Equation 4), the effective thermal conductivity λ of the entire standard vacuum insulation material is ｅｆｆ is calculated to be 2.79 mW / (m·K).

[0027] Here, the thermal conductivity is used as an index of the thermal insulation performance of a thermal insulation material. Generally, the relationship of thermal conductivity = effective thermal conductivity / thickness of the thermal insulation material holds. Therefore, when the same type of core material is used, if the effective thermal conductivity is reduced by 10% or more, the thickness of the vacuum insulation material (core material) required to obtain the same thermal conductivity can be reduced by 10% or more. In other words, if the vacuum insulation material has an effective thermal conductivity of 2.51 mW / mK, which is 10% or more lower than the effective thermal conductivity (2.79 mW / mK) of the above-mentioned standard vacuum insulation material, the thickness and weight of the vacuum insulation material can be reduced by 10% or more.

[0028] For example, the thermal conductivity is 0.1 W / m ２ The thickness of the standard vacuum insulation material (effective thermal conductivity 2.79 mW / mK) required to obtain a vacuum insulation material with a density of 200 kg / m is approximately 27.9 mm. As mentioned above, the thickness of the core material is significantly thicker than the thickness of the outer packaging material, so the weight of the vacuum insulation material can be roughly calculated as the weight of the core material. ３ In this case, the weight of the vacuum insulation material (core material) with a thickness of about 27.9 mm is 1.39 kg. In contrast, if the vacuum insulation material has an effective thermal conductivity of 2.48 mW / mK (effective thermal conductivity reduced by 11%), the heat transmission coefficient will be 0.1 W / m ２ The thickness of the vacuum insulation material required to achieve K can be reduced to approximately 24.8 mm. The density of the core material is 200 kg / m ３ In this case, the weight of the vacuum insulation material (core material) is approximately 1.24 kg. Therefore, the weight of the core material can be reduced by approximately 0.15 kg compared to the standard vacuum insulation material. In the case of an insulation box with 0.5 m square vacuum insulation material arranged on six sides, a weight reduction of approximately 0.9 kg per box can be expected. ３ It is expected that the internal volume will be expanded.

[0029] Substituting the effective thermal conductivity of the vacuum insulation material (0.00251 W / mK), which is 10% lower than the effective thermal conductivity of the standard vacuum insulation material using the standard film (0.00279 W / mK), into the above (Equation 4), yields (Equation 5) for calculating the thermal conductivity X of the outer packaging material that results in a vacuum insulation material having an effective thermal conductivity 10% lower than that of the standard vacuum insulation material. 0.00251≧0.002+X×T×2 / 0.25 X≦(0.00051×0.25) / (T×2) (Equation 5)

[0030] Next, the thermal diffusivity α in the plane direction of the outer packaging material that provides a vacuum insulation material with an effective thermal conductivity that is 10% lower than the effective thermal conductivity of the standard vacuum insulation material can be calculated from the above (Equation 5) and (Equation 3) using the following (Equation 1): X = V × α ≦ (0.00051 × 0.25) / (T × 2) α ≦ 6.375 × 10 －５ / (T × V) (Equation 1) (wherein α is the thermal diffusivity (m ２ / s), T is the thickness (m) of the vacuum insulation outer packaging material, V is the volumetric specific heat of the vacuum insulation outer packaging material, and ６ J / (m ３ ・K) or more 2.4×10 ６ J / (m ３ ・K) or less.

[0031] For the reasons stated above, the inventors of the present application have discovered that by using an outer packaging material whose thermal diffusivity α in the surface direction of the outer packaging material and thickness T satisfy the above-mentioned relationship, it is possible to make the vacuum insulation material thinner and reduce its weight. By using the outer packaging material of the present disclosure, it is possible to obtain a vacuum insulation material that is 10% or more lighter in weight than the standard vacuum insulation material while maintaining the same insulating performance as the standard vacuum insulation material using the above-mentioned standard film as the outer packaging material.

[0032] The outer packaging material for a vacuum insulator, the vacuum insulator, and the article with vacuum insulator according to the present disclosure will be described below.

[0033] A. Vacuum Insulation Packaging Material The vacuum insulation packaging material in this disclosure has a water vapor permeability of 0.1 g / (m ２ · day) or less, and the oxygen permeability is 0.1 cc / (m ２The thermal diffusivity α in the surface direction of the outer packaging material for vacuum insulation panels and the thickness T satisfy the following (Equation 1): α≦6.375×10 －５ / (T × V) (Equation 1) (wherein α is the thermal diffusivity (m ２ / s), T is the thickness (m) of the vacuum insulation outer packaging material, V is the volumetric specific heat of the vacuum insulation outer packaging material, and ６ J / (m ３ ・K) or more 2.4×10 ６ J / (m ３ ・K) or less.

[0034] The components and properties of the outer packaging material for vacuum insulation materials according to the present disclosure will be described in detail below.

[0035] 1. Physical Properties of the Vacuum Insulation Packaging Material (1) Thermal Diffusivity The vacuum insulation packaging material of the present disclosure has a thermal diffusivity α in the surface direction of the vacuum insulation packaging material and a thickness T that satisfy the following (Equation 1): α≦6.375×10 －５ / (T × V) (Equation 1) (wherein α is the thermal diffusivity (m ２ / s), T is the thickness (m) of the vacuum insulation outer packaging material, V is the volumetric specific heat of the vacuum insulation outer packaging material, and ６ J / (m ３ ・K) or more 2.4×10 ６ J / (m ３ ・K) or less.

[0036] According to the above formula (1), the outer packaging material for vacuum insulation material in the present disclosure has a thickness of 75 μm and a volume specific heat of 2.20 × 10 ６ J / (m ３ ・K), the thermal diffusivity in the surface direction is 3.86 × 10 －７ m ２ / s or less, and is 3.50 × 10 －７ m ２ / s or less, and may be 3.00 × 10 －７ m ２ On the other hand, the thermal diffusivity in the plane direction may be, for example, 2.20×10 －７ m ２ / s or more, and may be 2.50 × 10 －７ m２ / s or more.

[0037] According to the above formula (1), the outer packaging material for vacuum insulation material in the present disclosure has a thickness of 85 μm and a volume specific heat of 2.20 × 10 ６ J / (m ３ ・K), the thermal diffusivity in the surface direction is 3.41 × 10 －７ m ２ / s or less, and is 3.20 × 10 －７ m ２ / s or less, and may be 3.00 × 10 －７ m ２ On the other hand, the thermal diffusivity in the plane direction may be, for example, 2.20×10 －７ m ２ / s or more, and may be 2.50 × 10 －７ m ２ / s or more.

[0038] According to the above formula (1), the outer packaging material for vacuum insulation material in the present disclosure has a thickness of 95 μm and a volume specific heat of 2.20 × 10 ６ J / (m ３ ・K), the thermal diffusivity in the surface direction is 3.05 × 10 －７ m ２ / s or less, and is 3.00 × 10 －７ m ２ / s or less, and may be 2.80 × 10 －７ m ２ On the other hand, the thermal diffusivity in the plane direction may be, for example, 2.20×10 －７ m ２ / s or more, and may be 2.50 × 10 －７ m ２ / s or more.

[0039] According to the above formula (1), the outer packaging material for vacuum insulation material in the present disclosure has a thickness of 105 μm and a volume specific heat of 2.20 × 10 ６ J / (m ３ ・K), the thermal diffusivity in the surface direction is 2.76 × 10 －７ m ２ / s or less, and is 2.50 × 10 －７ m ２ / s or less, and may be 2.40 × 10 －７m ２ On the other hand, the thermal diffusivity in the plane direction may be, for example, 2.20×10 －７ m ２ / s or more, and may be 2.30 × 10 －７ m ２ / s or more.

[0040] In the present disclosure, in order to obtain an outer packaging material for a vacuum insulation material that satisfies the above formula 1, both the thermal diffusivity α of the outer packaging material and the thickness T of the outer packaging material are adjusted. The thermal diffusivity α of the outer packaging material can be adjusted by changing the composition of the inorganic layer of the gas barrier film contained in the outer packaging material, the composition of the inorganic layered compound layer, the number of gas barrier films, etc.

[0041] The thermal diffusivity in the surface direction of the outer packaging material is measured using an AC light thermal diffusivity measuring device, with the surface opposite the heat-sealable layer as the heated surface, and the value is measured under the following conditions. As an AC light thermal diffusivity measuring device, for example, a Laser PIT (manufactured by Advance Riko) can be used. <Measurement conditions> - Measurement temperature: 26°C - Heated surface: Surface opposite the heat-sealable layer of the outer packaging material - Frequency of heating light: 0.1 Hz - Atmosphere: Reduced pressure (0.01 Pa or less) - Surface treatment: Application of blackening agent (heated surface only)

[0042] (2) Water Vapor Permeability In order to maintain the vacuum state inside the vacuum insulation material for a long period of time, the outer packaging material for a vacuum insulation material is required to have gas barrier properties to suppress the permeation of gases such as oxygen and water vapor. The outer packaging material for a vacuum insulation material in the present disclosure has excellent gas barrier properties. The outer packaging material for a vacuum insulation material in the present disclosure usually has an initial water vapor permeability of 0.1 g / (m ２ · day) or less, and ２ In this way, the outer packaging material for a vacuum insulation material according to the present disclosure has excellent water vapor gas barrier properties.

[0043] The water vapor transmission rate is measured in accordance with ISO 15106-5:2015 (differential pressure method) using a water vapor transmission rate measuring device under conditions of a temperature of 40°C and a relative humidity difference of 90% RH. First, a sample of the outer packaging material for vacuum insulation material cut to a desired size is placed between the upper and lower chambers of the device so that the outermost surface opposite to the heat-sealable layer, which is one of the outermost surfaces facing each other in the thickness direction, is on the high humidity side (water vapor supply side). ２ Measurements are made under conditions of a temperature of 40°C and a relative humidity difference of 90% RH (permeation area: a circle with a diameter of 8 cm). The water vapor transmission rate measuring device used is, for example, a "DELTAPERM" manufactured by Technolox, UK. Measurements of water vapor transmission rate are made for at least three samples per vacuum insulation outer packaging material, and the average of these measurements is taken as the water vapor transmission rate value under those conditions.

[0044] (3) Oxygen permeability In the outer packaging material for vacuum insulation material in the present disclosure, the initial oxygen permeability is usually 0.1 cc / (m ２ ·day·atm) or less, and 0.01 cc / (m ２ ·day·atm) or less is more preferable.

[0045] The oxygen permeability is measured using an oxygen gas permeability measuring device under conditions of a temperature of 23°C and a humidity of 60% RH, with reference to JIS K7126-2:2006 (Plastics - Films and Sheets - Gas Permeability Testing Methods - Part 2: Isobaric Method, Appendix A: Testing Method for Oxygen Gas Permeability by Electrolytic Sensor Method). As an oxygen gas permeability measuring device, for example, an "OXTRAN" manufactured by MOCON Corporation, USA, is used. For the measurement, an outer packaging material for vacuum insulation panels cut to a desired size is placed in the device so that one of the two outermost surfaces facing each other in the thickness direction, the outermost surface opposite the heat-sealable layer, is in contact with oxygen gas, and the outermost surface is measured over a permeation area of ​​approximately 50 cm. ２Measurements are performed using a permeation area (circular with a diameter of 8 cm) with the carrier gas and test gas at a temperature of 23°C and a humidity of 60% RH. During the measurement, the carrier gas is supplied into the device at a flow rate of 10 cc / min for at least 60 minutes to purge. Nitrogen gas containing approximately 5% hydrogen can be used as the carrier gas. After purging, the test gas is flowed into the device, and measurements are performed after allowing 12 hours for the gas to reach equilibrium from the start of flow. The test gas used is at least 99.5% dry oxygen. Oxygen permeability measurements are performed on at least three samples under one condition, and the average of these measurements is used as the oxygen permeability value under that condition.

[0046] (4) Volumetric specific heat In the present disclosure, the volumetric specific heat of the outer packaging material shown in the following (Equation 2) is 2.2 × 10 ６ J / (m ３ ・K) or more 2.4×10 ６ J / (m ３ The volumetric specific heat of currently used outer packaging materials usually falls within the above range. Volumetric specific heat V [J / (m ３ ·K)] = specific heat capacity S [J / (kg ·K)] × density D [kg / m ３ ] (Formula 2)

[0047] The specific heat capacity S is a value obtained in accordance with the method for measuring the specific heat capacity of plastics specified in JIS K 7123:1987 at a measurement temperature of 26.85°C. The density D is a value measured from the weight and thickness of a 10 cm x 10 cm outer packaging material.

[0048] (5) Thickness The thickness of the outer packaging material in the present disclosure is not particularly limited as long as it satisfies the above formula (1). However, from the viewpoint of satisfying the above-mentioned oxygen permeability and water vapor permeability, it is, for example, 50 μm or more, preferably 75 μm or more, and more preferably 80 μm or more. On the other hand, the thickness of the outer packaging material is, for example, 120 μm or less, preferably 105 μm or less. If the thickness of the outer packaging material is too thick, it is difficult to obtain the range of thermal diffusivity α that satisfies the above formula (1). In particular, from the viewpoint of satisfying the above formula (1), the thickness of the outer packaging material is preferably 75 μm or less.

[0049] 2. Layer Structure: The vacuum insulation packaging material of the present disclosure is not particularly limited in its layer structure, so long as the thermal diffusivity and thickness in the in-plane direction satisfy the above-mentioned formula (1) and the water vapor permeability and oxygen permeability are within the above-mentioned ranges. FIG. 1 is a schematic cross-sectional view illustrating an example of a vacuum insulation packaging material of the present disclosure. As shown in FIG. 1, the vacuum insulation packaging material 10 of the present disclosure includes, for example, at least one gas barrier film (two gas barrier films F1 and F2 in FIG. 1) and a heat-sealable layer 1. When multiple gas barrier films are included, the layers are labeled F1 and F2 in order from the heat-sealable layer side. As shown in FIG. 1, an adhesive layer 4 may be present between the gas barrier film F1 and the heat-sealable layer 1, and between the two gas barrier films F1 and F2. The gas barrier films F1 and F2 shown in FIG. 1 each include a resin substrate 2 and an inorganic layer 3 disposed on one side of the resin substrate 2.

[0050] The number of gas barrier films included in the packaging material for vacuum insulation materials may be, for example, one, two, or three. From the viewpoint of satisfying the relationship of (Formula 1) above, it is preferable that the total number of inorganic layers included in the packaging material for vacuum insulation materials is small, for example, three or less layers, and preferably two or less layers. It is preferable that the inorganic layer of at least one of the gas barrier films is an inorganic compound layer. It is preferable that the total number of inorganic compound layers included in the packaging material for vacuum insulation materials is two or less. Furthermore, it is also possible that the inorganic layer of at least one of the gas barrier films is a metal layer. It is preferable that the total number of metal layers included in the packaging material for vacuum insulation materials is two or less.

[0051] In the vacuum insulation outer packaging material 10 according to the present disclosure, for example, as shown in Fig. 2, a protective film 5 may be disposed on the main surface opposite the heat-sealable layer 1. The protective film protects the gas barrier film. The protective film is distinguished from a gas barrier film in that no layer having gas barrier properties is disposed on either side of the protective film.

[0052] In the present disclosure, as shown in Figures 5 and 6, at least one of the gas barrier films (gas barrier film F1 in Figures 5 and 6) preferably has an inorganic layered compound layer 6 containing an inorganic layered compound and a binder resin on the side of the inorganic layer 3 opposite the resin substrate 2. The outer packaging material 10 for vacuum insulation materials shown in Figure 5 has, in this order, a heat-sealable layer 1, two gas barrier films F1 and F2, and a protective film 5. The outer packaging material 10 for vacuum insulation materials shown in Figure 6 has, in this order, a heat-sealable layer 1 and three gas barrier films F1, F2, and F3. In Figures 5 and 6, the gas barrier film F1 located closest to the heat-sealable layer 1 has, in this order from the heat-sealable layer 1 side, the resin substrate 2, the inorganic layer 3, and the inorganic layered compound layer 6. The gas barrier films F2 and F3 have, in this order from the gas barrier film F1 side, the inorganic layer 3 and the resin substrate 2.

[0053] From the viewpoint of satisfying the relationship of the above-mentioned (Equation 1), it is preferable that the outer packaging material for vacuum insulation materials does not have a metal layer. Examples of the metal layer include metal foils and thin metal films made of aluminum, nickel, stainless steel, iron, copper, titanium, etc. The absence of a metal layer in the outer packaging material for vacuum insulation materials can reduce the thermal diffusivity α. On the other hand, even outer packaging materials that do not have a metal layer may not satisfy the above-mentioned (Equation 1) depending on the thickness of the outer packaging material. Conversely, even outer packaging materials that have a metal layer may satisfy the above-mentioned (Equation 1) depending on the thickness of the outer packaging material. In the present disclosure, it is important to adjust the layer structure and thickness of the outer packaging material so as to satisfy the above-mentioned (Equation 1).

[0054] (1) Heat-sealable layer The vacuum insulation packaging material of the present disclosure preferably has a heat-sealable layer on one main surface. The heat-sealable layer is a layer that can be welded by heating. The heat-sealable layer is a member that forms one surface in the thickness direction of the vacuum insulation packaging material, comes into contact with the core material when producing a vacuum insulation material using the vacuum insulation packaging material of the present disclosure, and is a member that joins the ends of opposing vacuum insulation packaging materials when sealing the core material.

[0055] As the material for the heat-sealable layer, for example, a thermoplastic resin or a heat-meltable resin can be used, since it can be melted and fused by heating. Specific examples include polyolefin-based resins such as polyethylene, polypropylene, and cyclic polyolefins, polyester-based resins such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and polybutylene terephthalate (PBT), polyvinyl acetate-based resins, polyvinyl chloride-based resins, poly(meth)acrylic resins, and urethane resins. Among these, polyolefin-based resins are preferred. As described above, layers containing polyolefin-based resins have a low amount of dissolved gas, so when used as a vacuum insulation material, the amount of dissolved gas that penetrates into the interior can be reduced, and deterioration of the internal vacuum can be further suppressed.

[0056] The heat-sealable layer may contain additives such as anti-blocking agents, lubricants, flame retardants, and fillers, as required.

[0057] The thickness of the heat-sealable layer may be any thickness that allows the desired adhesive strength to be obtained when joining outer packaging materials for vacuum insulation materials together, and is preferably, for example, 15 μm or more and 100 μm or less, more preferably 25 μm or more and 90 μm or less, and even more preferably 30 μm or more and 80 μm or less.

[0058] (2) Gas Barrier Film The outer packaging material for a vacuum insulation material according to the present disclosure preferably includes a gas barrier film. The gas barrier film is disposed outside the heat-sealable layer and acts as a barrier against gases such as oxygen and water vapor, preventing the gases from penetrating from the outside to the inside of the vacuum insulation material.

[0059] The packaging material for a vacuum insulation material according to the present disclosure may have one gas barrier film or two or more gas barrier films. In particular, the packaging material for a vacuum insulation material according to the present disclosure preferably has two or more gas barrier films, because this improves the gas barrier properties.

[0060] The gas barrier film has, for example, a resin substrate and an inorganic layer disposed on at least one surface of the resin substrate. When the outer packaging material has one gas barrier film, it is preferable that the inorganic layer in the gas barrier film be disposed on the side of a layer that can be heat-sealed to the resin substrate. This is because gas dissolved in the resin substrate can be prevented from penetrating into the vacuum insulation material. When the outer packaging material has two or more gas barrier films, it is preferable that the inorganic layer in the innermost gas barrier film of the two or more gas barrier films be disposed on the side of a layer that can be heat-sealed to the resin substrate. As above, it is possible to prevent gas dissolved in the resin substrate from penetrating into the vacuum insulation material. When the outer packaging material has two or more gas barrier films, it is preferable that the inorganic layer in the outermost gas barrier film of the two or more gas barrier films be disposed on the side of a layer that can be heat-sealed to the resin substrate. This is because the inorganic layer can be protected by the resin substrate.

[0061] (a) Resin substrate: A film is preferably used as the resin substrate. When the resin substrate is a film, the film may be an unstretched film or a stretched film. The stretched film may be a uniaxially stretched film or a biaxially stretched film.

[0062] The resin substrate may or may not be transparent. Examples of materials that can be used for the resin substrate include polyolefin resins such as polyethylene, polypropylene, and cyclic polyolefin, polyester resins such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and polybutylene terephthalate (PBT), polystyrene resin, acrylonitrile-styrene copolymer (AS resin), acrylonitrile-butadiene-styrene copolymer (ABS resin), poly(meth)acrylic resin, polycarbonate resin, ethylene-vinyl ester copolymer and saponified products thereof, various polyamide resins such as nylon, polyimide resin, urethane resin, acetal resin, and cellulose resin.

[0063] The resin substrate may contain various plastic compounding agents and additives, etc. Examples of additives include lubricants, crosslinking agents, antioxidants, ultraviolet absorbers, light stabilizers, fillers, reinforcing agents, antistatic agents, pigments, and modifying resins.

[0064] The thickness of the resin substrate is not particularly limited, but is, for example, 6 μm or more and 200 μm or less, and preferably 9 μm or more and 100 μm or less.

[0065] (b) Inorganic Layer The gas barrier film according to the present disclosure has an inorganic layer disposed on at least one surface of the resin substrate. It is preferable that the inorganic layer and the resin substrate are in direct contact with each other. From the viewpoint of obtaining a thermal diffusivity that satisfies the above-mentioned formula (1), the inorganic layer is preferably a layer other than a metal layer, such as a metal foil or a metal thin film. Examples of the inorganic layer include an inorganic compound film, a film having an M-O-P bond (where M represents a metal atom, O represents an oxygen atom, and P represents a phosphorus atom), and a film containing a polyvalent metal salt of a polycarboxylic acid polymer. The inorganic layer according to the present disclosure is preferably an inorganic compound film, particularly a metal oxide film. On the other hand, the inorganic layer may be a metal layer. The metal layer is preferably a metal thin film, as described below.

[0066] Examples of inorganic compounds constituting the inorganic compound film include oxides, oxynitrides, nitrides, oxycarbides, and oxycarbonitrides of metal elements or nonmetal elements such as silicon, aluminum, magnesium, calcium, potassium, tin, sodium, titanium, boron, yttrium, zirconium, cerium, and zinc. Specifically, SiO ２ silicon oxides such as Al ２ O ３ Examples of the inorganic compound include aluminum oxide, magnesium oxide, titanium oxide, tin oxide, silicon-zinc alloy oxide, indium alloy oxide, silicon nitride, aluminum nitride, titanium nitride, silicon oxynitride, and zinc silicon oxide. Metal oxides, especially aluminum oxide (alumina) and silicon oxide (silica), are particularly preferred. The inorganic compound may be used alone or in any combination of the above materials.

[0067] The inorganic compound film may be a vapor-deposited film formed by a vapor deposition method, or a coated film formed by a coating method such as coating. In the case of a vapor-deposited film, it may be formed by a single vapor deposition or the like, or may be formed by multiple vapor depositions. The inorganic compound film can be formed using a conventionally known method such as a coating method, a vapor deposition method, or a pressure bonding method.

[0068] Among these, a vapor-deposited film is preferred from the viewpoint of high adhesion to the resin substrate and high gas barrier performance. One gas barrier film may be a single film formed by a single vapor deposition, or may have a laminated structure formed by multiple vapor depositions.

[0069] An example of a film having an M-O-P bond (where M represents a metal atom, O represents an oxygen atom, and P represents a phosphorus atom) is a film containing a reaction product of a metal oxide and a phosphorus compound.

[0070] Examples of the metal oxide include oxides of metals having a valence of 2 or more, specifically, oxides of metals such as metals in Group 2 of the periodic table, such as magnesium and calcium, metals in Group 12 of the periodic table, such as zinc, metals in Group 13 of the periodic table, such as aluminum, metals in Group 14 of the periodic table, such as silicon, and transition metals, such as titanium and zirconium. Of these, aluminum oxide (alumina) is preferred.

[0071] Examples of the phosphorus compound include phosphoric acid, polyphosphoric acid, phosphorous acid, phosphonic acid, and derivatives thereof. Among these, phosphoric acid is preferred. Specific reaction products of metal oxides and phosphorus compounds may be similar to those disclosed in, for example, JP 2011-226644 A.

[0072] The presence of the M-O-P bond can be confirmed by infrared absorption spectroscopy (measurement wavenumber range: 800 cm －１ More than 1400cm －１ Within the range below), the maximum infrared absorption peak is 1080 cm －１ 1130cm or more －１The infrared absorption spectrum can be confirmed by its appearance within the following range: The method for measuring the infrared absorption spectrum is not particularly limited, and examples thereof include a measurement method using attenuated total reflectance (ATR) method, a method in which a sample is scraped from the gas barrier film of the outer packaging material and the infrared absorption spectrum thereof is measured by the KBr method, and a method in which the collected sample is measured by microscopic infrared spectroscopy.

[0073] The thickness of the inorganic layer is not particularly limited, but is preferably 50 nm or less. By setting the thickness of the inorganic layer to the above value or less, sufficient flexibility can be maintained and barrier breakdown is less likely to occur.

[0074] The inorganic layer may have a single layer structure or a multilayer structure. In the case of a multilayer structure, films of the same composition may be combined, or films of different compositions may be combined.

[0075] The inorganic layer may be disposed on only one side of the resin substrate, or on each side of the resin substrate. The compositions and thicknesses of the two or more inorganic layers contained in the outer packaging material for a vacuum insulation material of the present disclosure may be the same or different.

[0076] The inorganic layer may be formed by any method that can form a film of the desired thickness on one or both sides of the resin substrate, and any conventionally known method such as coating, vapor deposition, or pressure bonding can be used depending on the type of gas barrier layer.

[0077] (c) Inorganic layered compound layer The gas barrier film preferably contains an inorganic layered compound layer as a barrier layer that complements the performance of the outer packaging material without using a metal layer. That is, at least one of the gas barrier films preferably has an inorganic layered compound layer on the side of the inorganic layer (preferably the inorganic compound layer) opposite the resin substrate. In order to improve the barrier properties, it is generally necessary to increase the number of barrier films. However, increasing the number of barrier films increases the overall thickness of the outer packaging material. By providing an inorganic layered compound layer, the thermal diffusivity α of the outer packaging material can be reduced while maintaining the overall thickness of the outer packaging material thin.

[0078] The inorganic layered compound layer contains at least an inorganic layered compound and a binder resin. Unlike a layer that prevents gas permeation by a continuous film such as a vapor-deposited thin film, the inorganic layered compound layer exhibits barrier properties by blocking and diverting the progress of gas (maze effect) due to the innumerable inorganic layered compounds dispersed within the layer, thereby extending the path required for gas permeation.

[0079] (c1) Inorganic layered compound: An inorganic layered compound is an inorganic compound that has a layered structure in which unit crystal layers are stacked on top of each other. In other words, a "layered compound" refers to a compound or substance that has a layered structure. Also, a "layered structure" refers to a structure in which densely arranged planes of atoms that are strongly bonded by covalent bonds or the like are stacked in parallel by weak bonding forces such as van der Waals forces.

[0080] The inorganic layered compound may be any compound having a layered structure, and examples thereof include graphite, phosphate derivative compounds (zirconium phosphate compounds), chalcogenides, clay minerals, etc. Among these, clay minerals are preferred.

[0081] Specific examples of clay minerals include phyllosilicate minerals such as hydrous silicates; kaolinite clay minerals such as halloysite, kaolinite, endelite, dickite, and nacrite; antigorite clay minerals such as antigorite and chrysotile; smectite clay minerals such as montmorillonite, iron-montmorillonite, beidellite, nontronite, saponite, hectorite, sauconite, and stevensite; vermiculite clay minerals such as vermiculite; micas such as muscovite and phlogopite; mica or mica clay minerals such as margarite, tetrasilylic mica, and taeniolite; chlorite clay minerals such as cookeite, sudoite, clinochlore, chamosite, and nimite, as well as substituted or derivatives thereof. These clay minerals may be natural or synthetic, or may be used in combination of two or more.

[0082] The average particle size of the inorganic layered compound particles is preferably 50 nm or more and 5 μm or less, and more preferably 100 nm or more and 4 μm or less. By setting the average particle size of the inorganic layered compound particles in the above range, the oxygen barrier performance of the inorganic layered compound layer is improved. The particle size of the inorganic layered compound particles is the median diameter (major diameter) determined by photon correlation spectroscopy using a dynamic light scattering method measured using an ultrafine particle size analyzer at a temperature of 25°C and in an aqueous solvent.

[0083] The aspect ratio of the inorganic layered compound is preferably 50 or more and 5000 or less, and more preferably 200 or more and 3000 or less. By setting the aspect ratio of the inorganic layered compound within the above range, the oxygen barrier performance of the inorganic layered compound layer is improved. The aspect ratio of the inorganic layered compound is the ratio of the average interplanar spacing (average unit thickness) to the average particle size of the particles of the inorganic layered compound, and is calculated by the following formula: Z = L / a (In the above formula, Z is the aspect ratio, L is the average particle size of the inorganic layered compound, and a is the average interplanar spacing (average unit thickness) of the inorganic layered compound.)

[0084] The average particle size L of the inorganic layered compound is the value determined by the above-mentioned method. The interplanar spacing (unit thickness) a of the inorganic layered compound is a value determined, for example, by powder X-ray diffraction measurement of the inorganic layered compound using an X-ray diffractometer. It can be confirmed from powder X-ray diffraction measurement of a composition containing an inorganic layered compound and a binder resin that there are portions where the interplanar spacing of the inorganic layered compound is widened.

[0085] (c2) Binder Resin The binder resin is not particularly limited, but a hydrophilic resin containing a hydrophilic group is preferred. This is because hydrophilic resins exhibit high barrier properties against oxygen. Specific examples include polyvinyl alcohol (PVA), ethylene-vinyl alcohol copolymer (EVOH), polyacrylonitrile (PAN), polyacrylic acid or a salt thereof, polybenzenesulfonic acid or a salt thereof, polyethyleneimine, polyallylamine, polyglycerin, etc., and further examples include polysaccharides such as hydroxymethyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, amylose, amylopectin, curdlan, xanthan, chitin, cellulose, pullulan, and chitosan. In the present disclosure, polyvinyl alcohol and polyacrylic acid are particularly preferred.

[0086] Hydrophilic resins generally have a tendency to lose their gas barrier properties due to water vapor. However, as shown in Figure 5, the layered compound layer 6 is sandwiched between the inorganic layer 3 of the barrier film F1 and the inorganic layer 3 of the barrier film F2, which makes it possible to suppress deterioration of the hydrophilic resin and maintain high oxygen barrier properties of the inorganic layered compound layer.

[0087] (c3) Other inorganic layered compound layers have improved oxygen barrier performance as the volume of the inorganic layered compound increases. On the other hand, the volume of the binder resin increases as the volume increases. Therefore, the volume ratio of the inorganic layered compound to the binder resin (inorganic layered compound / resin) is preferably 5 / 95 to 90 / 10, and more preferably 5 / 95 to 50 / 50. By setting the volume ratio of the inorganic layered compound to the binder resin within the above range, an inorganic layered compound layer having excellent oxygen barrier performance and flex resistance can be obtained.

[0088] The thickness of the inorganic layered compound layer is preferably 1 μm or less, and more preferably 50 nm or more and 500 nm or less. By setting the thickness of the inorganic layered compound layer within this range, it is possible to exhibit sufficient oxygen barrier performance, and also to make the hardness of the inorganic layered compound layer relatively small, so that even when the outer packaging material for a vacuum insulation material is subjected to bending stress, the layer structure of the inorganic layered compound in the inorganic layered compound layer can be maintained.

[0089] (d) Overcoat layer: At least one of the gas barrier films according to the present disclosure preferably has an overcoat layer disposed on the main surface of the inorganic layer opposite the resin substrate. By providing an overcoat layer, it is possible to impart even better gas barrier properties to the outer packaging material for a vacuum insulation material.

[0090] The overcoat layer contains a hydrophilic group-containing resin. The presence or absence of the hydrophilic group-containing resin can be determined, for example, by infrared absorption spectroscopy. Furthermore, the ratio of metal atoms to carbon atoms (number of metal atoms / number of carbon atoms) among the atoms constituting the overcoat layer is in the range of 0.1 to 2, preferably in the range of 0.5 to 1.9, and particularly preferably in the range of 0.8 to 1.6. If the ratio is below the above range, the overcoat layer may become more brittle, and the water resistance and weather resistance of the resulting overcoat layer may be reduced. On the other hand, if the ratio exceeds the above range, the gas barrier properties of the resulting overcoat layer may be reduced.

[0091] An overcoat layer having the above-mentioned ratio can be obtained, for example, by adjusting the content of the hydrophilic group-containing resin in the overcoat layer-forming composition to a blending ratio within the range of 5 parts by mass or more and 500 parts by mass or less, particularly 20 parts by mass or more and 200 parts by mass or less, relative to 100 parts by mass of the total amount of alkoxide described below. An example of the overcoat layer-forming composition can be a colorless and transparent overcoat layer-forming composition obtained by a sol-gel method, in which a pre-prepared liquid B (a hydrolysis liquid consisting of tetraethoxysilane (TEOS), isopropyl alcohol, hydrochloric acid, and ion-exchanged water) is added to a liquid A (a mixed liquid consisting of polyvinyl alcohol (PVA), isopropyl alcohol, and ion-exchanged water) so that the PVA is in a specific ratio relative to 100 parts by mass of TEOS, and the mixture is stirred.

[0092] Although there are no particular limitations on the thickness of the overcoat layer, it is preferably 200 nm or more, because this value or more can reliably improve the gas barrier properties of the outer packaging material for a vacuum heat insulating material.

[0093] (3) As described above, in order to obtain a thermal diffusivity that satisfies the above formula (1), it is preferable that the outer packaging material does not have a metal layer such as a metal foil or a metal thin film. On the other hand, by reducing the thickness of the outer packaging material, the above formula (1) may be satisfied even if the outer packaging material has a metal layer. In this case, the thickness of the outer packaging material is, for example, 95 μm or less, or may be 85 μm or less, or may be 75 μm or less.

[0094] For example, the outer packaging material may have a gas barrier film having a metal foil. Examples of metal foils used in gas barrier films include aluminum, nickel, stainless steel, iron, copper, and titanium foils. Metal foils have good gas barrier properties and are excellent in bending resistance and puncture resistance. Furthermore, aluminum foil is easy to process and inexpensive. A gas barrier film having a metal foil may be composed of only a metal foil, or may be composed of multiple metal foils, or may have other layers laminated on the metal foil.

[0095] The gas barrier film may also be a gas barrier film having a resin substrate and a metal thin film as an inorganic layer, such as a thin metal film made of aluminum, nickel, stainless steel, iron, copper, or titanium.

[0096] 3. Adhesive Layer In the outer packaging material for vacuum insulation materials according to the present disclosure, the layers constituting the outer packaging material may be arranged in direct contact with each other by heat welding or the like, or may be arranged via an adhesive layer.

[0097] Examples of adhesives used in the adhesive layer include pressure-sensitive adhesives, thermoplastic adhesives, and curable adhesives. For example, a two-component curing adhesive containing a base agent and a curing agent is used. Alternatively, a one-component curing adhesive containing a base agent and a latent curing agent blocked by a known method so as not to react when mixed with the base agent, or a one-component curing adhesive containing a curing agent and a latent base agent blocked by a known method so as not to react when mixed with the curing agent, may be used.

[0098] Specific examples of adhesives that can be used include epoxy adhesives, polyvinyl acetate adhesives, polyacrylic ester adhesives, cyanoacrylate adhesives, ethylene copolymer adhesives, cellulose adhesives, polyester adhesives, polyamide adhesives, polyimide adhesives, amino resin adhesives, phenol resin adhesives, polyurethane adhesives, reactive (meth)acrylic acid adhesives, inorganic rubber adhesives, silicone adhesives, and inorganic adhesives made of alkali metal silicates, low-melting point glass, etc.

[0099] Among these, the adhesive is preferably a polyacrylic ester adhesive or a polyurethane adhesive. In particular, the adhesive preferably contains a compound having an isocyanate group as a functional group, and specifically, a polyurethane adhesive is preferred.

[0100] The adhesive may contain any material such as a curing accelerator, a catalyst, an antioxidant, a stabilizer, an ultraviolet absorber, a light stabilizer, an antistatic agent, and the like.

[0101] The thickness of the adhesive layer may be any thickness that can exhibit the desired adhesive strength, and may be appropriately set depending on the composition of the adhesive layer, etc. The thickness of the adhesive layer may be, for example, 0.1 μm or more and less than 10 μm, or 1 μm or more and 4 μm or less.

[0102] The adhesive layer may or may not have transparency. When transparency is required as an outer packaging material for a vacuum heat insulating material, the adhesive layer preferably has transparency.

[0103] The adhesive layer may be a sheet- or film-shaped adhesive, or may be formed by applying an adhesive composition, followed by drying and curing.

[0104] 4. Protective Film In the outer packaging material 10 for vacuum insulation materials according to the present disclosure, a protective film 5 may be disposed on the main surface opposite the heat-sealable layer 1, as shown in Fig. 2, for example. The protective film is disposed on the side of the gas barrier film opposite the heat-sealable layer, and protects the gas barrier film. The protective film is distinguished from the gas barrier film in that no layer having gas barrier properties is disposed on either side of the protective film.

[0105] Examples of materials for the protective film include polyester resins such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and polybutylene terephthalate (PBT), and polyamide resins such as nylon.

[0106] The thickness of the protective film is not particularly limited, and may be, for example, 5 μm or more and 200 μm or less, or 10 μm or more and 100 μm or less.

[0107] 5. Others As shown in Figure 2, the outer packaging material for a vacuum insulation material according to the present disclosure preferably has a heat-sealable layer 1, a first gas barrier film F1, a second gas barrier film F2, and a protective film 5, in this order in the thickness direction, and the protective film 5 is preferably a nylon film, and each of the first gas barrier film F1 and the second gas barrier film F2 is preferably a gas barrier film including a resin substrate and an inorganic compound layer.

[0108] The outer packaging material for a vacuum insulation material according to the present disclosure may or may not have transparency, and this can be set appropriately depending on the application of the vacuum insulation material that the outer packaging material for a vacuum insulation material according to the present disclosure is to be used in. The transparency of the outer packaging material for a vacuum insulation material is not strictly defined by transmittance, but can be determined appropriately depending on the application, etc.

[0109] When the outer packaging material for a vacuum insulation material according to the present disclosure is transparent, the interior of the vacuum insulation material using the outer packaging material for a vacuum insulation material can be visually confirmed. Therefore, by placing a detecting agent together with a core material inside the vacuum insulation material, it becomes possible to visually confirm the internal vacuum state from changes in the detecting agent.

[0110] The vacuum insulation packaging material of the present disclosure may be produced, for example, by laminating pre-produced films together via the adhesive layer described above. Alternatively, the vacuum insulation packaging material of the present disclosure may be produced by sequentially extruding and laminating the raw materials of the films that have been heat-melted using a T-die or the like.

[0111] The outer packaging material for a vacuum insulator according to the present disclosure can be used in a vacuum insulator. In the vacuum insulator, the outer packaging material for a vacuum insulator according to the present disclosure can be used by arranging the heat-sealable layer on the core material side and facing the core material therebetween.

[0112] B. Vacuum Insulation Material The vacuum insulation material in the present disclosure is a vacuum insulation material having a core material and an outer packaging material that encapsulates the core material, and the outer packaging material is the outer packaging material for a vacuum insulation material described above.

[0113] Fig. 3(a) is a schematic perspective view showing an example of a vacuum insulation material according to the present disclosure, and Fig. 3(b) is a cross-sectional view taken along the line X-X of Fig. 3(a). The vacuum insulation material 50 shown in Fig. 3 has a core material 11 and an outer packaging material 10 that encloses the core material 11, and the outer packaging material 10 is the outer packaging material for the vacuum insulation material described in Fig. 1. The vacuum insulation material 50 is a bag formed by two outer packaging materials 10 arranged so that their heat-sealable layers face each other and their ends 12 are joined by heat fusion, with the core material 11 enclosed within the bag and the interior of the bag being depressurized.

[0114] According to the present disclosure, by using the above-mentioned outer packaging material for vacuum insulation materials as the outer packaging material for the core material, the vacuum insulation material can be reduced in weight while maintaining good insulation performance. For example, a vacuum insulation material using the outer packaging material of the present disclosure can be obtained that is 10% or more lighter in weight than a standard vacuum insulation material using the above-mentioned standard film as the outer packaging material while maintaining insulation performance equivalent to that of the standard vacuum insulation material.

[0115] Below, the vacuum insulation material of the present disclosure will be described for each configuration.

[0116] 1. Outer packaging material for vacuum insulation material The outer packaging material for vacuum insulation material in this disclosure is a component that encloses the core material, and is the same as the outer packaging material for vacuum insulation material explained above in the section "A. Outer packaging material for vacuum insulation material," so explanation here will be omitted.

[0117] 2. Core Material The core material in this disclosure is a component that is enclosed by the outer packaging material for vacuum insulation material. Enclosed means that the core material is sealed inside the bag formed using the outer packaging material for vacuum insulation material.

[0118] The core material preferably has low thermal conductivity. The core material may be a porous material with a porosity of 50% or more, particularly 90% or more.

[0119] Materials that can be used to form the core material include powders, foams, fibers, and the like. The powders can be either inorganic or organic, and examples of such materials include dry silica, wet silica, agglomerated silica powder, conductive powder, calcium carbonate powder, perlite, clay, and talc. A mixture of dry silica and conductive powder is particularly advantageous for use in a temperature range where internal pressure increases, because it reduces the loss of insulation performance associated with an increase in the internal pressure of the vacuum insulation material. Furthermore, adding a substance with low infrared absorptivity, such as titanium oxide, aluminum oxide, or indium-doped tin oxide, to the above-mentioned materials as a radiation suppressor can reduce the infrared absorptivity of the core material.

[0120] The foam may be urethane foam, styrene foam, phenol foam, etc. Among them, foams that form open cells are preferred.

[0121] The fibrous material may be either inorganic or organic, but inorganic fibers are preferred from the viewpoint of heat insulating performance. Examples of such inorganic fibers include glass fibers such as glass wool and glass fiber, alumina fibers, silica-alumina fibers, silica fibers, ceramic fibers, and rock wool. These inorganic fibers are preferred because they have low thermal conductivity and are easier to handle than powders.

[0122] The core material may be any of the above materials, or may be a composite material made by mixing two or more materials.

[0123] 3. Other features of the vacuum insulation material disclosed herein include that a core material is enclosed inside an outer packaging material for vacuum insulation material, and the interior is reduced in pressure to create a vacuum. The degree of vacuum inside the vacuum insulation material is preferably, for example, 5 Pa or less. This is because it is possible to reduce heat conduction due to convection of air remaining inside, enabling the material to exhibit excellent heat insulation properties.

[0124] The lower the thermal conductivity of the vacuum insulation material, the more preferable. For example, it is preferable that the thermal conductivity (initial thermal conductivity) is 5 mW / (mK) or less. This is because the vacuum insulation material is less likely to conduct heat to the outside, and can provide a high thermal insulation effect. In particular, it is more preferable that the initial thermal conductivity is 4 mW / (mK) or less. The thermal conductivity is a value measured in accordance with JIS A1412-2:1999 under conditions of a high temperature side of 30°C, a low temperature side of 10°C, and an average temperature of 20°C.

[0125] The vacuum insulation material of the present disclosure can be manufactured by a general method. For example, two sheets of the above-described outer packaging material for vacuum insulation material are prepared, stacked with their heat-sealable layers facing each other, and the outer edges of three sides are heat-sealed to obtain a bag with one side open. After placing a core material in this bag through the opening, air is sucked through the opening and the opening is sealed while the inside of the bag is decompressed, thereby obtaining the vacuum insulation material.

[0126] The vacuum insulation material of the present disclosure can be used, for example, in articles requiring thermal insulation, as described below.

[0127] C. Vacuum Insulated Article The vacuum insulated article of the present disclosure is an article having a thermal insulation region and a vacuum insulated article including a vacuum insulated material, wherein the vacuum insulated material has a core material and an outer packaging material in which the core material is enclosed, and the outer packaging material is the outer packaging material for vacuum insulated material described above.

[0128] According to the present disclosure, the vacuum insulation material used in an article has the above-described outer packaging material for the vacuum insulation material, so that the vacuum insulation material can be made lighter while maintaining its excellent insulating performance. By providing such a vacuum insulation material in an article, energy savings can be achieved for the article or the object in which the article is used, which will be exposed to high-temperature or high-temperature, high-humidity environments. Furthermore, for example, when such a vacuum insulation material is used in an insulating box, the weight of the insulating box can be reduced and the internal volume can be increased.

[0129] The vacuum insulation material and the outer packaging material for vacuum insulation material used therein in this disclosure have been described in detail in the above sections "B. Vacuum insulation material" and "A. Outer packaging material for vacuum insulation material," so further description will be omitted here.

[0130] The article of the present disclosure has a thermally insulated region. Here, the thermally insulated region is a region thermally insulated by vacuum insulation material, such as a region that is insulated to a warm or cold temperature, a region that surrounds a heat source or a cooling source, or a region that is isolated from a heat source or a cooling source. These regions may be spaces or objects. The article of the present disclosure preferably includes an insulated box containing the above-mentioned vacuum insulation material. The insulated box preferably has, for example, a total of six surfaces, including top, bottom, and side surfaces, and vacuum insulation material is disposed on each surface.

[0131] Examples of the above-mentioned goods include electrical equipment such as refrigerators, freezers, warmers, and coolers; containers such as warm-insulating containers, cold-insulating containers, transport containers, containers, and storage containers; vehicles such as cars, aircraft, and ships; buildings such as houses and warehouses; and building materials such as wall materials and floor materials.

[0132] D. Manufacturing Method of Vacuum Insulation Packaging Material The present disclosure provides a manufacturing method of a vacuum insulation packaging material having one or more gas barrier films and a heat-sealable layer, wherein the vacuum insulation packaging material has a water vapor permeability of 0.1 g / (m ２· day) or less, and the oxygen permeability is 0.1 cc / (m ２ The present invention also provides a method for producing an outer packaging material for a vacuum insulation material, which comprises selecting and laminating at least one or more gas barrier films and the heat-sealable layer so that the thermal diffusivity α in the plane direction of the outer packaging material for a vacuum insulation material and the thickness T satisfy the following (Equation 1): α≦6.375×10 －５ / (T × V) (Equation 1) (wherein α is the thermal diffusivity (m ２ / s), T is the thickness (m) of the outer packaging material for vacuum insulation panels, V is the volumetric specific heat of the outer packaging material for vacuum insulation panels, and ６ J / (m ３ ・K) or more 2.4×10 ６ J / (m ３ ・K) or less.

[0133] According to the present disclosure, for the reasons described above, an outer packaging material can be obtained that can reduce the thickness and weight of a vacuum insulation material by selecting and laminating at least one gas barrier film and one or more heat-sealable layers so that both the thermal diffusivity α of the outer packaging material and the thickness T of the outer packaging material satisfy the above-mentioned (Equation 1). By using the outer packaging material of the present disclosure, it is possible to obtain a vacuum insulation material that is 10% or more lighter in weight than a standard vacuum insulation material while maintaining the same insulation performance as a standard vacuum insulation material using the above-mentioned standard film as the outer packaging material.

[0134] The gas barrier film and heat-sealable film selected in the method for producing an outer packaging material for a vacuum insulation material of the present disclosure are the same as those described above in "A. Outer packaging material for a vacuum insulation material."

[0135] The present disclosure is not limited to the above-described embodiments. The above-described embodiments are merely examples, and any embodiment that has substantially the same configuration as the technical idea described in the claims of the present disclosure and exhibits similar effects is included within the technical scope of the present disclosure.

[0136] The present disclosure will be described in more detail below with reference to examples and comparative examples.

[0137] (Example 1) A linear low-density polyethylene film (thickness: 50 μm) was prepared as the heat-sealable film. As the gas barrier film A, a film was prepared in which alumina was vapor-deposited on one side of a PET film (thickness: 12 μm), and the following coating layer (PVA+TEOS layer: 250 nm) was provided on the vapor-deposited film. As the protective film B, a nylon film (thickness: 25 μm) was prepared.

[0138] (Coating layer (PVA + TEOS layer)) Liquid B (a hydrolysis liquid consisting of tetraethoxysilane (TEOS), isopropyl alcohol, hydrochloric acid, and ion-exchanged water) previously prepared according to the composition shown below was added to Liquid A (a mixed liquid consisting of polyvinyl alcohol, isopropyl alcohol, and water) prepared according to the composition shown below, and the mixture was stirred to obtain a colorless and transparent coating layer composition by the sol-gel method. The coating layer composition was coated onto a vapor-deposited film to be coated by gravure coating, and then the coating was heated at 120°C, 140°C, and 150°C for 20 seconds each, and aged at 55°C for 1 week to obtain a coating layer (PVA + TEOS layer) as a second barrier layer.

[0139] <Composition of PVA+TEOS layer composition> (Solution A) Polyvinyl alcohol: 1.81% by mass Isopropyl alcohol: 39.80% by mass Water: 2.09% by mass (Solution B) Tetraethoxysilane: 21.49% by mass Isopropyl alcohol: 5.03% by mass 0.5N hydrochloric acid aqueous solution: 0.69% by mass Ion-exchanged water: 29.10% by mass (*Solutions A and B combined equal 100% by mass)

[0140] An outer packaging material for a vacuum insulation material was obtained having, in this order, a protective film B as a first layer, a gas barrier film A as a second layer, a gas barrier film A as a third layer, and a heat-sealable film as a fourth layer. The second-layer gas barrier film A was positioned so that the PVA+TEOS layer faced the third-layer gas barrier film A. The third-layer gas barrier film A was positioned so that the PVA+TEOS layer faced the second-layer gas barrier film A.

[0141] That is, in Example 1, an outer packaging material for a vacuum insulation material was obtained having a layer structure in which the layers were laminated in the following order: protective film B / / gas barrier film A (PET film / alumina vapor deposition layer / PVA + TEOS layer) / / gas barrier film A (PVA + TEOS layer / alumina vapor deposition layer / PET film) / / heat-sealable film (LLDPE film). Note that " / " indicates that the two are in direct contact, and " / / " indicates that they are in contact via an interlayer adhesive layer.

[0142] The total thickness of the vacuum insulation packaging material is 1.10 x 10 －４ The thickness was m. The results of measuring the thermal diffusivity in the in-plane direction, water vapor permeability, oxygen permeability, specific heat capacity, and density are shown in Table 1. The measurement methods for each parameter were as described above. The results of calculating the volumetric specific heat and thermal conductivity from the above (Equation 2) and (Equation 3) are shown in Table 1.

[0143] By substituting the volumetric specific heat and thickness into the above (Equation 1), the thermal diffusivity α≦2.51×10 ―７ m ２ The thermal diffusivity (measured value) in the plane direction of the vacuum insulation packaging material obtained above was 2.4 × 10 ―７ m ２ / s, which satisfied the above (Equation 1).

[0144] In the above formula (3), α = 2.4 × 10 ―７ m ２ / s and volumetric specific heat V = 2.30 x 10 ６ J / (m ３ The thermal conductivity X of the outer packaging material was calculated by substituting λ ｃｏｐ= 0.002 W / (m·K), the horizontal length and vertical length are each 0.5 m (i.e., p = 2 m, L １ ×L ２ = 0.25 m ２ ) vacuum insulation material, and the effective thermal conductivity of the entire vacuum insulation material was calculated using the above (Equation 4), resulting in 2.48 × 10 －３ W / (m·K).

[0145] (Comparative Example 1) A linear low-density polyethylene film (thickness 50 μm) was prepared as the heat-sealable film, a metal aluminum foil (6 μm) was prepared as the gas barrier film B, a nylon film (thickness 15 μm) was prepared as the protective film A, and a nylon film (thickness 25 μm) was prepared as the protective film B.

[0146] An outer packaging material for a vacuum heat insulating material was obtained having, in this order, protective film A as the first layer, protective film B as the second layer, gas barrier film B as the third layer, and a heat-sealable film as the fourth layer.

[0147] That is, in Comparative Example 1, an outer packaging material for vacuum insulation materials was obtained having a layer structure in which the layers were laminated in the following order: Protective film A / / Protective film B / / Gas barrier film B / / Heat-sealable film (LLDPE film). Note that " / " indicates that the two are in direct contact, and " / / " indicates that they are in contact via an interlayer adhesive layer.

[0148] The thickness of the outer packaging material for vacuum insulation is 1.05 x 10 －４ The thickness was m. The results of measuring the thermal diffusivity in the in-plane direction, water vapor permeability, oxygen permeability, specific heat capacity, and density are shown in Table 1. The measurement methods for each parameter were as described above. The results of calculating the volumetric specific heat and thermal conductivity from the above (Equation 2) and (Equation 3) are shown in Table 1.

[0149] By substituting the volumetric specific heat and thickness into the above (Equation 1), the thermal diffusivity α≦2.57×10 ―７ m ２ The measured thermal diffusivity in the plane direction of the vacuum insulation outer packaging material obtained above was 7.2 × 10 ―６ m ２ / s, which did not satisfy the above (Equation 1).

[0150] The thermal conductivity X of the outer packaging material was calculated using the above formula (3) and was found to be 17.00 W / (m·K). ｃｏｐ = 0.002 W / (m·K), the horizontal length and vertical length are each 0.5 m (i.e., p = 2 m, L １ ×L ２ = 0.25 m ２ ) vacuum insulation material, and the effective thermal conductivity of the entire vacuum insulation material was calculated using the above (Equation 4), and the result was 16.27 × 10 －３ W / (m·K).

[0151] (Example 2) A linear low-density polyethylene film (thickness: 30 μm) was prepared as a heat-sealable film, one sheet of the gas barrier film A used in Example 1, a PET film (thickness: 12 μm) having metal aluminum vapor-deposited on one side as gas barrier film C, and an EVOH film (thickness: 12 μm) having metal aluminum vapor-deposited on one side as gas barrier film D were prepared.

[0152] An outer packaging material for a vacuum insulation material was obtained having, in this order, a gas barrier film A as the first layer, a gas barrier film C as the second layer, a gas barrier film D as the third layer, and a heat-sealable film as the fourth layer. The first-layer gas barrier film A was arranged so that the PVA+TEOS layer was on the side of the second-layer gas barrier film C. The second-layer gas barrier film C was arranged so that the metal aluminum layer was on the side of the third-layer gas barrier film D. The third-layer gas barrier film D was arranged so that the metal aluminum layer was on the side of the second-layer gas barrier film C.

[0153] That is, in Example 2, an outer packaging material for a vacuum insulation material was obtained having a layer structure in which the layers were laminated in the following order: gas barrier film A (PET film / alumina vapor deposition layer / PVA+TEOS layer) / / gas barrier film C (PET / metallic aluminum layer) / / gas barrier film D (metallic aluminum layer / EVOH) / / heat-sealable film (LLDPE film).

[0154] The thickness of the outer packaging material for vacuum insulation is 7.3 x 10 －５The thickness was m. The results of measuring the thermal diffusivity in the in-plane direction, water vapor permeability, oxygen permeability, specific heat capacity, and density are shown in Table 2. The measurement methods for each parameter were as described above. The results of calculating the volumetric specific heat and thermal conductivity from the above (Equation 2) and (Equation 3) are shown in Table 2.

[0155] By substituting the volumetric specific heat and thickness into the above (Equation 1), the thermal diffusivity α≦3.6×10 ―７ m ２ The thermal diffusivity in the plane direction of the vacuum insulation packaging material obtained above was measured to be 3.4 × 10 ―７ m ２ / s, which satisfied the above (Equation 1).

[0156] The thermal conductivity X of the outer packaging material was calculated using the above formula (3) and was found to be 0.82 W / (m·K). ｃｏｐ = 0.002 W / (m·K), the horizontal length and vertical length are each 0.5 m (i.e., p = 2 m, L １ ×L ２ = 0.25 m ２ ) vacuum insulation material, and the effective thermal conductivity of the entire vacuum insulation material was calculated using the above (Equation 4), resulting in 2.47 × 10 －３ W / (m·K).

[0157] (Example 3) As heat-sealable films, a linear low-density polyethylene film (thickness: 30 μm), one sheet of the gas barrier film A used in Example 1, and two sheets of the gas barrier film C used in Example 2 were prepared.

[0158] An outer packaging material for vacuum insulation materials was obtained having, in this order, gas barrier film A as the first layer, gas barrier film C as the second layer, gas barrier film C as the third layer, and a heat-sealable film as the fourth layer. The first-layer gas barrier film A was arranged so that the PVA+TEOS layer was on the side of the second-layer gas barrier film C. The second-layer gas barrier film C was arranged so that the metal aluminum layer was on the side of the third-layer gas barrier film C. The third-layer gas barrier film C was arranged so that the metal aluminum layer was on the side of the second-layer gas barrier film C.

[0159] That is, in Example 3, an outer packaging material for vacuum insulation material was obtained having a layer structure in which the layers were laminated in the following order: gas barrier film A (PET film / alumina vapor deposition layer / PVA+TEOS layer) / / gas barrier film C (PET / metallic aluminum layer) / / gas barrier film C (metallic aluminum layer / PET) / / heat-sealable film (LLDPE film).

[0160] The thickness of the outer packaging material for vacuum insulation is 7.3 x 10 －５ The thickness was m. The results of measuring the thermal diffusivity in the in-plane direction, water vapor permeability, oxygen permeability, specific heat capacity, and density are shown in Table 2. The measurement methods for each parameter were as described above. The results of calculating the volumetric specific heat and thermal conductivity from the above (Equation 2) and (Equation 3) are shown in Table 2.

[0161] By substituting the volumetric specific heat and thickness into the above (Equation 1), the thermal diffusivity α≦3.7×10 ―７ m ２ The thermal diffusivity in the plane direction of the vacuum insulation packaging material obtained above was measured to be 3.2 × 10 ―７ m ２ / s, which satisfied the above (Equation 1).

[0162] The thermal conductivity X of the outer packaging material was calculated using the above (Equation 3) and was found to be 0.76 W / (m·K). ｃｏｐ = 0.002 W / (m·K), the horizontal length and vertical length are each 0.5 m (i.e., p = 2 m, L １ ×L ２ = 0.25 m ２ ) vacuum insulation material, and the effective thermal conductivity of the entire vacuum insulation material was calculated using the above (Equation 4), resulting in 2.44 × 10 －３ W / (m·K).

[0163] (Example 4) As heat-sealable films, a linear low-density polyethylene film (thickness 50 μm), the gas barrier film A used in Example 1, and protective film B (nylon film (thickness 25 μm)) were prepared. Furthermore, as gas barrier film E, a film having a PET film (thickness 12 μm), an alumina vapor deposition layer, and an inorganic layered compound dispersion layer in this order was prepared.

[0164] An outer packaging material for a vacuum insulation material was obtained having, in this order, a protective film B as a first layer, a gas barrier film A as a second layer, a gas barrier film E as a third layer, and a heat-sealable film as a fourth layer. The second-layer gas barrier film A was positioned so that the PVA+TEOS layer faced the third-layer gas barrier film E. The third-layer gas barrier film E was positioned so that the inorganic layered compound layer faced the second-layer gas barrier film A.

[0165] That is, in Example 4, an outer packaging material for a vacuum insulation material was obtained having a layer structure in which the layers were laminated in the following order: protective film B / / gas barrier film A (PET film / alumina vapor deposition layer / PVA + TEOS layer) / / gas barrier film E (inorganic layered compound dispersion layer / alumina vapor deposition layer / PET) / / heat-sealable film (LLDPE film).

[0166] The thickness of the outer packaging material for vacuum insulation is 1.1 x 10 －４ The thickness was m. The results of measuring the thermal diffusivity in the in-plane direction, water vapor permeability, oxygen permeability, specific heat capacity, and density are shown in Table 1. The measurement methods for each parameter were as described above. The results of calculating the volumetric specific heat and thermal conductivity from the above (Equation 2) and (Equation 3) are shown in Table 1.

[0167] By substituting the volumetric specific heat and thickness into the above (Equation 1), the thermal diffusivity α≦2.4×10 ―７ m ２ The measured thermal diffusivity in the plane direction of the vacuum insulation outer packaging material obtained above was 2.3 × 10 ―７ m ２ / s, which satisfied the above (Equation 1).

[0168] The thermal conductivity X of the outer packaging material was calculated using the above formula (3) and was found to be 0.55 W / (m·K). ｃｏｐ = 0.002 W / (m·K), the horizontal length and vertical length are each 0.5 m (i.e., p = 2 m, L １ ×L ２ = 0.25 m ２ ) vacuum insulation material, and the effective thermal conductivity of the entire vacuum insulation material was calculated using the above (Equation 4), resulting in 2.48 × 10 －３ W / (m·K).

[0169] Comparative Example 2 As heat-sealable films, a linear low-density polyethylene film (thickness: 50 μm), two sheets of the gas barrier film A used in Example 1, and two sheets of protective film B (nylon film (thickness: 25 μm)) were prepared.

[0170] An outer packaging material for a vacuum insulation material was obtained having, in this order, protective film B as the first layer, protective film B as the second layer, gas barrier film A as the third layer, gas barrier film A as the fourth layer, and a heat-sealable film as the fifth layer. The third-layer gas barrier film A was arranged so that the PVA+TEOS layer faced the fourth-layer gas barrier film A. The fourth-layer gas barrier film A was arranged so that the PVA+TEOS layer faced the third-layer gas barrier film A.

[0171] That is, in Comparative Example 2, an outer packaging material for a vacuum insulation material was obtained having a layer structure in which the layers were laminated in the following order: protective film B / / protective film B / / gas barrier film A (PET film / alumina vapor deposition layer / PVA + TEOS layer) / / gas barrier film A (PVA + TEOS layer / alumina vapor deposition layer / PET film) / / heat-sealable film (LLDPE film).

[0172] The thickness of the outer packaging material for vacuum insulation is 1.36 x 10 －４ The thickness was m. The results of measuring the thermal diffusivity in the in-plane direction, water vapor permeability, oxygen permeability, specific heat capacity, and density are shown in Table 2. The measurement methods for each parameter were as described above. The results of calculating the volumetric specific heat and thermal conductivity from the above (Equation 2) and (Equation 3) are shown in Table 2.

[0173] By substituting the volumetric specific heat and thickness into the above (Equation 1), the thermal diffusivity α≦2.1×10 ―７ m ２ The thermal diffusivity in the plane direction of the vacuum insulation packaging material obtained above was measured to be 2.4 × 10 ―７ m ２ / s, which did not satisfy the above (Equation 1).

[0174] The thermal conductivity X of the outer packaging material was calculated using the above formula (3) and was found to be 0.53 W / (m·K). ｃｏｐ= 0.002 W / (m·K), the horizontal length and vertical length are each 0.5 m (i.e., p = 2 m, L １ ×L ２ = 0.25 m ２ ) vacuum insulation material, and the effective thermal conductivity of the entire vacuum insulation material was calculated using the above (Equation 4), resulting in 2.57 × 10 －３ W / (m·K).

[0175] (Comparative Example 3) As heat-sealable films, a linear low-density polyethylene film (thickness: 50 μm), two sheets of the gas barrier film A used in Example 1, a gas barrier film D, and a protective film B (a nylon film (thickness: 25 μm)) were prepared.

[0176] An outer packaging material for vacuum insulation materials was obtained having, in this order, protective film B as the first layer, barrier film A as the second layer, gas barrier film A as the third layer, gas barrier film D as the fourth layer, and a heat-sealable film as the fifth layer. The second-layer gas barrier film A was positioned so that the PVA+TEOS layer faced the third-layer gas barrier film A. The third-layer gas barrier film A was positioned so that the PVA+TEOS layer faced the fourth-layer gas barrier film D.

[0177] That is, in Comparative Example 3, an outer packaging material for vacuum insulation material was obtained having a layer structure in which the layers were laminated in the following order: protective film B / / gas barrier film A (PET film / alumina vapor deposition layer / PVA + TEOS layer) / / gas barrier film A (PET film / alumina vapor deposition layer / PVA + TEOS layer) / / gas barrier film D (metallic aluminum layer / EVOH) / / heat-sealable film (LLDPE film).

[0178] The thickness of the outer packaging material for vacuum insulation is 1.21 x 10 －４ The thickness was m. The results of measuring the thermal diffusivity in the in-plane direction, water vapor permeability, oxygen permeability, specific heat capacity, and density are shown in Table 2. The measurement methods for each parameter were as described above. The results of calculating the volumetric specific heat and thermal conductivity from the above (Equation 2) and (Equation 3) are shown in Table 2.

[0179] By substituting the volumetric specific heat and thickness into the above (Equation 1), the thermal diffusivity α≦2.2×10―７ m ２ The measured thermal diffusivity in the plane direction of the vacuum insulation packaging material obtained above was 2.8 × 10 ―７ m ２ / s, which did not satisfy the above (Equation 1).

[0180] The thermal conductivity X of the outer packaging material was calculated using the above formula (3) and was found to be 0.66 W / (m·K). ｃｏｐ = 0.002 W / (m·K), the horizontal length and vertical length are each 0.5 m (i.e., p = 2 m, L １ ×L ２ = 0.25 m ２ ) vacuum insulation material, and the effective thermal conductivity of the entire vacuum insulation material was calculated using the above (Equation 4), resulting in 2.64 × 10 －３ W / (m·K).

[0181] The outer packaging materials obtained in the above Examples and Comparative Examples were used, and the permeability was 0.1 W / (m ２ The thickness of the vacuum insulation material and the weight of the core material required to obtain a vacuum insulation material with a thermal conductivity of 0.1 W / (m ２ -K) The thickness of the vacuum insulation material and the weight of the core material required to obtain the vacuum insulation material are shown.

[0182] A vacuum insulation material using the reference film as an outer packaging material, a vacuum insulation material using the outer packaging material of Example 1, and a vacuum insulation material using the outer packaging material of Example 4 were stored under conditions of 70°C and 90RH for the time periods shown in Table 1, and the thermal conductivity after storage was measured using the method described above. The thickness of the vacuum insulation material and the weight of the core material were as shown in Table 1. As shown in Table 1, the vacuum insulation material using the outer packaging material obtained in the example had a thermal conductivity equivalent to that of the vacuum insulation material using the reference film as an outer packaging material, confirming that it fully functions as an outer packaging material.

[0183]

[0184]

[0185] (Experimental Examples 1-1 to 1-15, Comparative Experimental Examples 1-1 to 1-2) The thickness T of the outer packaging material was 75×10 －６ m, and the volumetric specific heat is 2.2 J × 10 ６ J / (m ３ ・K) or more 2.4×10 ６ J / (m ３ The upper limit of the thermal diffusivity α calculated from the above (Equation 1) was calculated for each experimental example and comparative experimental example. The thermal conductivity of the outer packaging material was also calculated from the thermal diffusivity and volumetric specific heat shown in the table using (Equation 3). Next, λ ｃｏｐ = 0.002 W / (m·K), the horizontal length and vertical length are each 0.5 m (i.e., p = 2 m, L １ ×L ２ = 0.25 m ２ The effective thermal conductivity of each vacuum insulation material was calculated using (Equation 4) assuming a vacuum insulation material of 0.1 W / m. The ratio of the effective thermal conductivity of the vacuum insulation material of each experimental example and comparative experimental example to the effective thermal conductivity of the vacuum insulation material using the reference film was calculated (in the table, the ratio is shown as the reference example). ２ The thickness of the vacuum insulation material and the weight of the core material required to achieve a temperature of 100 K were calculated. The results of these calculations are shown in Tables 3 and 4.

[0186]

[0187]

[0188] (Experimental Examples 2-1 to 2-10, Comparative Experimental Examples 2-1 to 2-10) The thickness T of the outer packaging material was 95×10 －６ m, and the volumetric specific heat is 2.2 J × 10 ６ J / (m ３ ・K) or more 2.4×10 ６ J / (m ３ The upper limit of the thermal diffusivity α calculated from the above (Equation 1) was calculated. The thermal conductivity of the outer packaging material was calculated from each thermal diffusivity and volumetric specific heat shown in the table using (Equation 3). Next, λ ｃｏｐ = 0.002 W / (m·K), the horizontal length and vertical length are each 0.5 m (i.e., p = 2 m, L １ ×L ２ = 0.25 m ２The effective thermal conductivity of each vacuum insulation material was calculated using Equation 4. The ratio of the effective thermal conductivity of the vacuum insulation material of each experimental example to the effective thermal conductivity of the vacuum insulation material using the reference film was calculated (in the table, the ratio is shown as the reference example). ２ The thickness of the vacuum insulation material and the weight of the core material required to achieve a temperature of 100 K were calculated. The results of these calculations are shown in Tables 5 and 6.

[0189]

[0190]

[0191] As shown in Tables 3 to 6, it was confirmed that if the outer packaging material satisfies (Equation 1), a vacuum insulation material can be obtained that can reduce the weight of the core material by 10% or more while maintaining heat insulation performance.

[0192] Thus, the present disclosure provides, for example, the following inventions.

[0193] [1] An outer packaging material for vacuum insulation materials, having a water vapor permeability of 0.1 g / (m ２ · day) or less, and the oxygen permeability is 0.1 cc / (m ２ The thermal diffusivity α in the surface direction of the outer packaging material for a vacuum heat insulating material and the thickness T of the outer packaging material for a vacuum heat insulating material satisfy the following (Equation 1): α≦6.375×10 －５ / (T × V) (Equation 1) (wherein α is the thermal diffusivity (m ２ / s), T is the thickness (m) of the outer packaging material for vacuum insulation panels, V is the volumetric specific heat of the outer packaging material for vacuum insulation panels, and ６ J / (m ３ ・K) or more 2.4×10 ６ J / (m ３ ・K) or less.

[0194] [2] The water vapor permeability is 0.01 g / (m ２ The outer packaging material for vacuum insulation materials according to [1], wherein the average temperature is 100°C or less.

[0195] [3] The oxygen permeability is 0.01 cc / (m ２The outer packaging material for vacuum insulation materials according to [1] or [2], wherein the temperature is 1000°C (day-atm) or less.

[0196] [4] The packaging material for a vacuum heat insulating material according to any one of [1] to [3], wherein the thickness of the packaging material for a vacuum heat insulating material is 75 μm or less.

[0197] [5] The packaging material for a vacuum insulation material according to any one of [1] to [4], wherein the packaging material for a vacuum insulation material has one or more gas barrier films and a heat-sealable layer, wherein the one or more gas barrier films each have a resin substrate and an inorganic layer disposed on at least one surface of the resin substrate, and the resin substrate is any one of a polyolefin-based resin film, a polyamide-based resin film, and a polyester-based resin film.

[0198] [6] The outer packaging material for a vacuum insulation material according to [5], wherein the inorganic layer of at least one of the gas barrier films is an inorganic compound layer.

[0199] [7] The outer packaging material for a vacuum insulation material according to [6], wherein the inorganic compound layer is a vapor deposition film.

[0200] [8] The packaging material for a vacuum heat insulating material according to [6] or [7], wherein the number of inorganic compound layers contained in the packaging material for a vacuum heat insulating material is two or less. [9]

[0201] [5] The outer packaging material for a vacuum insulation material according to [5], wherein the inorganic layer of at least one of the gas barrier films is a metal layer.

[0202]

[10] At least one of the gas barrier films has an inorganic layered compound layer containing an inorganic layered compound and a binder resin on the side of the inorganic layer opposite to the resin substrate.

[11] The outer packaging material for a vacuum insulation material according to any one of [5] to [9].

[0203]

[11] The outer packaging material for a vacuum insulation material according to any one of [5] to

[10] , which has a protective film arranged on the opposite side of the gas barrier film from the heat-sealable layer.

[0204]

[12] The outer packaging material for a vacuum insulation material according to

[11] , wherein the protective film is a nylon film and the inorganic layer is an inorganic compound layer.

[0205]

[13] A vacuum insulation material having a core material and an outer packaging material in which the core material is enclosed, wherein the outer packaging material is the outer packaging material for vacuum insulation material described in any of [1] to

[12] .

[14] An article with vacuum insulation material comprising an article having a thermal insulation region and a vacuum insulation material, wherein the vacuum insulation material has a core material and an outer packaging material in which the core material is enclosed, and the outer packaging material is the outer packaging material for vacuum insulation material described in any of [1] to

[12] .

[0206]

[15] The vacuum insulated article according to

[14] , comprising an insulating box containing the vacuum insulated material.

[0207]

[16] A method for producing an outer packaging material for a vacuum insulation material, the outer packaging material having one or more gas barrier films and a heat-sealable layer, wherein the outer packaging material for a vacuum insulation material has a water vapor permeability of 0.1 g / (m ２ · day) or less, and the oxygen permeability is 0.1 cc / (m ２ and at least one or more gas barrier films and the heat-sealable layer are selected and laminated so that the thermal diffusivity α in the surface direction of the outer packaging material for a vacuum insulation material and the thickness T of the outer packaging material for a vacuum insulation material satisfy the following (Equation 1): α≦6.375×10 －５ / (T × V) (Equation 1) (wherein α is the thermal diffusivity (m ２ / s), T is the thickness (m) of the outer packaging material for vacuum insulation panels, V is the volumetric specific heat of the outer packaging material for vacuum insulation panels, and ６ J / (m ３ ・K) or more 2.4×10 ６ J / (m ３ ・K) or less.

[0208] REFERENCE SIGNS LIST 1 ... heat-sealable layer 2 ... resin substrate 3 ... gas barrier layer 4 ... adhesive layer 5 ... protective film 6 ... inorganic layered compound layer 10 ... outer packaging material for vacuum insulation material 11 ... core material 50 ... vacuum insulation material

Claims

1. An outer packaging material for vacuum insulation material, with a water vapor permeability of 0.1 g / (m ２ · day) or less, and the oxygen permeability is 0.1 cc / (m ２ The thermal diffusivity α in the surface direction of the outer packaging material for a vacuum heat insulating material and the thickness T of the outer packaging material for a vacuum heat insulating material satisfy the following (Equation 1): α≦6.375×10 －５ / (T × V) (Equation 1) (wherein α is the thermal diffusivity (m ２ / s), T is the thickness (m) of the outer packaging material for vacuum insulation panels, V is the volumetric specific heat of the outer packaging material for vacuum insulation panels, and ６ J / (m ３ ・K) or more 2.4×10 ６ J / (m ３ ・K) or less.

2. The water vapor permeability is 0.01 g / (m ２ The outer packaging material for vacuum insulation materials according to claim 1, wherein the heat resistance is 1000 times or less.

3. The oxygen permeability is 0.01 cc / (m ２ 2. The outer packaging material for vacuum insulation materials according to claim 1, wherein the temperature is 100°C or less.

4. The packaging material for vacuum insulation material according to claim 1, wherein the thickness of the packaging material for vacuum insulation material is 75 μm or less.

5. The packaging material for vacuum insulation material according to claim 1, wherein the packaging material for vacuum insulation material has one or more gas barrier films and a heat-sealable layer, each of the one or more gas barrier films having a resin substrate and an inorganic layer disposed on at least one surface of the resin substrate, and the resin substrate is any one of a polyolefin-based resin film, a polyamide-based resin film, and a polyester-based resin film.

6. The outer packaging material for vacuum insulation materials according to claim 5, wherein the inorganic layer of at least one of the gas barrier films is an inorganic compound layer.

7. The packaging material for vacuum insulation materials according to claim 6, wherein the inorganic compound layer is a vapor deposition film.

8. The packaging material for vacuum insulation materials according to claim 6, wherein the number of inorganic compound layers contained in the packaging material for vacuum insulation materials is two or less.

9. The outer packaging material for vacuum insulation materials according to claim 5, wherein the inorganic layer of at least one of the gas barrier films is a metal layer.

10. An outer packaging material for vacuum insulation material as described in claim 5, wherein at least one of the gas barrier films has an inorganic layered compound layer containing an inorganic layered compound and a binder resin on the side of the inorganic layer opposite the resin substrate.

11. The outer packaging material for vacuum insulation material according to claim 5, further comprising a protective film disposed on the gas barrier film opposite the heat-sealable layer.

12. The packaging material for a vacuum insulation material according to claim 11, wherein the protective film is a nylon film and the inorganic layer is an inorganic compound layer.

13. A vacuum insulation material having a core material and an outer packaging material in which the core material is enclosed, wherein the outer packaging material is an outer packaging material for vacuum insulation material as defined in any one of claims 1 to 12.

14. An article with vacuum insulation comprising an article having a thermal insulation region and a vacuum insulation material, wherein the vacuum insulation material has a core material and an outer packaging material in which the core material is enclosed, and the outer packaging material is an outer packaging material for vacuum insulation material as defined in any one of claims 1 to 12.

15. The vacuum insulated article of claim 14, wherein the vacuum insulated article comprises an insulated box containing the vacuum insulated material.

16. A method for producing an outer packaging material for a vacuum insulation material, which has one or more gas barrier films and a heat-sealable layer, wherein the outer packaging material for a vacuum insulation material has a water vapor permeability of 0.1 g / (m ２ · day) or less, and the oxygen permeability is 0.1 cc / (m ２ and at least one or more gas barrier films and the heat-sealable layer are selected and laminated so that the thermal diffusivity α in the surface direction of the outer packaging material for a vacuum insulation material and the thickness T of the outer packaging material for a vacuum insulation material satisfy the following (Equation 1): α≦6.375×10 －５ / (T × V) (Equation 1) (wherein α is the thermal diffusivity (m ２ / s), T is the thickness (m) of the outer packaging material for vacuum insulation panels, V is the volumetric specific heat of the outer packaging material for vacuum insulation panels, and ６ J / (m ３ ・K) or more 2.4×10 ６ J / (m ３ ・K) or less.

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