JP2018189240A - Outer packing material for vacuum heat insulation material, vacuum heat insulation material, and article with vacuum heat insulation material - Google Patents

Abstract

An outer packaging material for a vacuum heat insulating material is provided. A gas barrier film having a heat-weldable film 1, resin base materials 3A, 3B, 3C and gas barrier films 4A, 4B, 4C arranged on one surface side of the resin base materials 3A, 3B, 3C. 2A, 2B, and 2C, and at least one of the gas barrier films 4A, 4B, and 4C is a vacuum heat insulating material envelope 10 that is a metal aluminum film, and has a temperature of 70 ° C. and a humidity of 90 The thickness expansion coefficient of the metal aluminum film farthest from the heat-weldable film 1 after holding for 500 hours in an atmosphere of% RH is not more than a predetermined value. [Selection] Figure 1

Description

  The present disclosure relates to an outer packaging material used for a vacuum heat insulating material.

  In recent years, vacuum heat insulating materials have been used for the purpose of energy saving of articles. The vacuum heat insulating material is good because the core material is arranged in the bag body of the outer packaging material and the bag body is maintained in a vacuum state whose pressure is lower than the atmospheric pressure, and the internal heat convection is suppressed. Insulation performance can be demonstrated. In addition, the outer packaging material used for a vacuum heat insulating material is called and called the outer packaging material for vacuum heat insulating materials, or just an outer packaging material.

  The outer packaging material for vacuum heat insulating material has a gas barrier property for suppressing the permeation of gas such as oxygen and water vapor, a bag body by joining the end parts, in order to maintain the vacuum state inside the vacuum heat insulating material for a long time, Physical properties such as heat welding property for sealing and sealing the material are required. In order to satisfy these physical properties, the outer packaging material generally employs a configuration including a gas barrier layer and a heat-weldable film as members (Patent Documents 1 to 4).

  The gas barrier layer has a metal foil having a thickness of several μm to several tens of μm, or a gas barrier film having a thickness of several nm to several hundreds of nm on one surface of a resin substrate, and the gas barrier film contains an inorganic substance. Is used. Among them, the gas barrier film can exhibit a high gas barrier performance even when it is thin, forms a vacuum heat insulating material because it is less likely to generate a heat bridge than a metal foil and has better flexibility than a metal foil. At the same time, since the occurrence of defects caused by receiving external stress such as bending and the accompanying deterioration in gas barrier performance are unlikely to occur, the adoption as a gas barrier layer of a vacuum insulation outer packaging material has been promoted.

JP 2003-262296 A JP 2013-103343 A JP 2006-70923 A JP 2014-62562 A

  As the inorganic substance constituting the gas barrier film, a metal, an inorganic oxide, or the like is used. Among these, metal aluminum can form a gas barrier film having high gas barrier performance at a relatively low cost. However, when used in a high-temperature and high-humidity environment with a temperature of 70 ° C. and a humidity of 90% RH, the outer packaging material using a gas barrier film having a metal aluminum film deteriorates with time, resulting in long favorable gas barrier performance. There is a problem that it is difficult to maintain the period. Further, the vacuum heat insulating material formed using such an outer packaging material has a problem that it is difficult to maintain the heat insulating performance for a long period of time in a high temperature and high humidity environment due to a decrease in gas barrier performance of the outer packaging material. .

  The present disclosure has been made in view of the above circumstances, and is an outer packaging material for a vacuum heat insulating material capable of maintaining gas barrier performance for a long period of time in a high temperature and high humidity environment, and a vacuum heat insulating material and a vacuum heat insulating material using the same. The main purpose is to provide articles with materials.

  The present disclosure includes a heat-weldable film, and one or more gas barrier films having a resin base material and a gas barrier film disposed on one surface side of the resin base material, and at least one of the gas barrier films Is an outer packaging material for a vacuum heat insulating material, which is a metal aluminum film, and is the metal aluminum film most distant from the heat weldable film after being held in an atmosphere of a temperature of 70 ° C. and a humidity of 90% RH for 500 hours. An outer packaging material for a vacuum heat insulating material having a thickness expansion coefficient of 200% or less is provided.

  Moreover, this indication is a vacuum heat insulating material which has a core material and the outer packaging material in which the said core material was enclosed, Comprising: The said outer packaging material provides the vacuum heat insulating material which is the outer packaging material for vacuum insulation mentioned above. .

  In addition, the present disclosure is an article with a heat insulating region and an article with a vacuum heat insulating material including a vacuum heat insulating material, and the vacuum heat insulating material includes a core material and an outer packaging material in which the core material is enclosed. Provided is an article with a vacuum heat insulating material, wherein the outer packaging material is the above-described vacuum heat insulating outer packaging material.

  According to the present disclosure, it is possible to provide an outer packaging material for a vacuum heat insulating material capable of maintaining gas barrier performance for a long period of time in a high temperature and high humidity environment. In addition, according to the present disclosure, a vacuum heat insulating material capable of maintaining heat insulating performance for a long period of time in a high-temperature and high-humidity environment by using the above-described outer packaging material for a vacuum heat insulating material, and an article including the vacuum heat insulating material There is an effect that can be provided.

It is a schematic sectional drawing which shows an example of the outer packaging material for vacuum heat insulating materials of this indication. It is the schematic perspective view and sectional drawing which show an example of the vacuum heat insulating material of this indication.

  The present disclosure includes, in an embodiment, an outer packaging material for a vacuum heat insulating material, a vacuum heat insulating material, and an article with a vacuum heat insulating 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 modes, and should not be construed as being limited to the description of the embodiments described below. Further, in order to clarify the description, the drawings may be schematically represented with respect to the width, thickness, shape, etc. of each part as compared with the embodiment, but are merely examples, and the interpretation of the present disclosure may be interpreted. It is not limited. In addition, in the present specification and each drawing, elements similar to those described above with reference to the previous drawings are denoted by the same reference numerals, and detailed description may be omitted as appropriate. Further, for convenience of explanation, the description may be made using the terms “upper” or “lower”, but the vertical direction may be reversed.

  Further, in this specification, when a certain configuration such as a certain member or a certain region is “above (or below)” another configuration such as another member or another region, there is no particular limitation. As long as this is not just above (or directly below) other configurations, but also above (or below) other configurations, i.e. Including the case where the above-mentioned components are included.

I. The outer packaging material for vacuum heat insulating material The outer packaging material for vacuum heat insulating material of the present disclosure is one gas barrier film having a heat-weldable film, a resin base material, and a gas barrier film disposed on one surface side of the resin base material. And at least one gas barrier film is an outer packaging material for a vacuum heat insulating material, which is a metal aluminum film, and the heat after holding for 500 hours in an atmosphere at a temperature of 70 ° C. and a humidity of 90% RH The thickness expansion coefficient of the metal aluminum film that is farthest from the weldable film is 200% or less.

  Metallic aluminum is distinguished from aluminum compounds such as aluminum hydroxide and aluminum oxide.

  FIG. 1 is a schematic cross-sectional view illustrating an example of an outer packaging material for a vacuum heat insulating material according to the present disclosure, which includes a heat-weldable film 1 and three gas barrier films 2A, 2B, and 2C. The gas barrier films 2A, 2B, and 2C have gas barrier films 4A, 4B, and 4C disposed on one surface side of the resin base materials 3A, 3B, and 3C and the resin base materials 3A, 3B, and 3C, respectively. In FIG. 1, among the gas barrier films 2A, 2B, and 2C, the gas barrier film 4B of the gas barrier film 2B is a metal aluminum film. The outer packaging material 10 for vacuum heat insulating material of the present disclosure has an expansion coefficient of the thickness T of the metal aluminum film 4B farthest from the heat-weldable film 1 after holding for 500 hours in an atmosphere at a temperature of 70 ° C. and a humidity of 90% RH. Is below a predetermined value.

  When an outer packaging material including a gas barrier film having a metal aluminum film as a gas barrier film is used in a high temperature and high humidity environment with a temperature of 70 ° C. and a humidity of 90% RH, the gas barrier performance tends to deteriorate with time. The present inventors have learned that the above-mentioned tendency that occurs in a high-temperature and high-humidity environment is due to the reaction between metallic aluminum and water vapor.

That is, the metal aluminum constituting the gas barrier film reacts when it comes into contact with high-temperature water vapor to become a hydroxide, and the hydroxide further hydrolyzes to become an oxide depending on the environmental temperature. Here, when metal aluminum reacts with water vapor to form a compound, the volume of the metal aluminum expands more than that of the metal aluminum alone, so that the film thickness of the gas barrier film also increases. When the thickness of the gas barrier film is increased, the bending resistance is deteriorated. Therefore, when the gas barrier film receives mechanical stress from an external force such as bending, the stress is concentrated and defects such as cracks are easily generated. Further, when the resin base material in contact with the gas barrier film is exposed to a high-temperature and high-humidity environment, it thermally expands and contracts depending on the type of resin. The gas barrier film concentrates on the stress generated by the thermal expansion and contraction of the resin base material, so that defects such as cracks are more likely to occur. Then, it is presumed that the gas barrier performance of the entire outer packaging material is deteriorated by allowing gas to easily enter from a defective portion generated in the gas barrier film.
Furthermore, since the gas barrier performance of aluminum hydroxide is lower than that of metal aluminum, if the metal aluminum constituting the gas barrier film reacts with water vapor to form aluminum hydroxide in a high temperature and high humidity environment, the gas barrier performance of the gas barrier film Is greatly reduced from the initial performance.
In this way, when an outer packaging material containing a metal aluminum film is used in a high temperature and high humidity environment for a long period of time, the property changes due to contact between the gas barrier film and water vapor, so the gas barrier performance exhibited by the metal aluminum film is maintained for a long period of time. I guess it will be difficult to do.

  Among these, the position of the metal aluminum film in the outer packaging material is the position away from the heat-weldable film, that is, the position closer to the outermost surface when the outer packaging material is used as a vacuum heat insulating material, the metal aluminum film is the main surface. In this case, it is presumed that it is easy to come into contact with water vapor in the outside air and the metal aluminum is easily hydroxylated or oxidized. In the outer packaging material, the gas barrier film is in contact with a resin base material, another member such as a protective film, and a resin layer such as an adhesive layer for adhering to the other member. It is presumed that when the moisture is absorbed, the main surface of the metal aluminum film, which is a gas barrier film, comes into contact with the water vapor contained in the resin layer, so that the metal aluminum is more easily hydroxylated or oxidized.

  Furthermore, when the outer packaging material has a plurality of gas barrier films, the metal aluminum film of the gas barrier film located farthest from the heat-weldable film deteriorates, so that water vapor easily penetrates into the outer packaging material. For this reason, the penetration of water vapor must be prevented by another gas barrier film located on the side of the heat-weldable film than the metal aluminum film. In some cases, the contact may deteriorate, and as a result, the gas barrier performance of the entire outer packaging material may be further reduced. Therefore, among the gas barrier films constituting the outer packaging material, when the gas barrier film located farthest from the heat-weldable film has a metal aluminum film as the gas barrier film, the deterioration of the gas barrier film due to wet heat is particularly likely to occur. It is thought that it greatly contributes to the deterioration of the gas barrier performance of the whole material.

  Therefore, the present inventors specify the thickness expansion coefficient of the metallic aluminum film farthest from the heat-weldable film before and after holding the outer packaging material for a predetermined time in a predetermined high-temperature and high-humidity environment. It has been found that the gas barrier performance of the outer packaging material can be maintained for a long time even in a humid environment. In addition, by using the outer packaging material having the above characteristics as the outer packaging material constituting the vacuum thermal insulating material, it is found that the vacuum thermal insulating material can maintain the thermal insulation performance for a long period of time in a high temperature and high humidity environment. It was. Specifically, the outer packaging material of the present disclosure, as will be described in the examples described later, is the heat of the vacuum heat insulating material after being held for 150 hours in an atmosphere having a temperature of 70 ° C. and a humidity of 90% with respect to the initial thermal conductivity. The conductivity ratio can be reduced.

  Hereinafter, the characteristics and configuration of the outer packaging material according to the present disclosure will be described.

A. Characteristics The outer packaging material of the present disclosure has a thickness expansion coefficient of the metal aluminum film farthest from the heat-weldable film after holding for 500 hours in an atmosphere of a temperature of 70 ° C. and a humidity of 90% RH is equal to or less than a predetermined value. .

  The “metal aluminum film farthest from the heat-weldable film” is referred to as “outermost metal aluminum film”, and the above after holding for 500 hours in an atmosphere at a temperature of 70 ° C. and a humidity of 90% RH. The “thickness expansion coefficient of the metal aluminum film most distant from the heat-weldable film” may be referred to as “thickness expansion coefficient of the outermost metal aluminum film after being kept at high temperature and high humidity” or simply “thickness expansion coefficient”. is there.

Specifically, in the outer packaging material of the present disclosure, the thickness expansion coefficient of the outermost metallic aluminum film after holding at high temperature and high humidity may be 200% or less, preferably 150% or less, particularly 130% or less. It is preferable that As the reaction between the metal aluminum film and water vapor progresses, the proportion of metal aluminum becoming a compound such as aluminum hydroxide increases, and the volume expansion of the outermost metal aluminum film increases, so that the temperature is 70 ° C. and the humidity is 90% RH. The thickness of the outermost metallic aluminum film becomes larger than before holding in the atmosphere, that is, before holding at high temperature and high humidity. That is, the thickness expansion coefficient of the outermost metallic aluminum film after holding at high temperature and high humidity indicates the degree to which the metallic aluminum film reacted with water vapor and changed to a compound such as hydroxide.
In addition, the lower limit of the thickness expansion rate is not particularly limited, but it is preferable that the expansion of the thickness is small before and after holding at high temperature and high humidity, and in particular, the thickness does not expand, that is, 100%.

In the present disclosure, when the thickness expansion coefficient of the outermost metallic aluminum film after being held at high temperature and high humidity is within the above range, it is possible to suppress a decrease in gas barrier performance due to a change in the properties of the gas barrier film. In addition, a decrease in the bending resistance of the gas barrier film due to an increase in film thickness is suppressed, and a defect is formed in the gas barrier film due to a stress caused by thermal expansion or contraction of a resin layer such as a resin base material or mechanical stress such as bending. Can be suppressed.
Furthermore, it becomes difficult to produce a defect in the adhesion between the outermost metal aluminum film and the layer in contact therewith, and a decrease in the adhesive strength between the outermost metal aluminum film and each layer can be suppressed. Furthermore, even in an environment where the outermost metal aluminum film is in contact with water vapor at a high temperature, the gas barrier performance of the outermost metal aluminum film is suppressed from being lowered. Other gas barrier films can be protected from external high humidity environments. Thereby, the fall of the gas barrier performance of another gas barrier film can be suppressed, and it becomes possible to maintain favorable gas barrier performance for the whole outer packaging material for a long period of time.

The thickness expansion coefficient of the outermost metal aluminum film after holding at high temperature and high humidity is the thickness T ₁ of the outermost metal aluminum film before holding in an atmosphere at a temperature of 70 ° C. and a humidity of 90% RH, that is, before holding at high temperature and high humidity. and the thickness T ₂ of the outermost metallic aluminum film after high temperature and high humidity retention, can be calculated by the following equation (1).
Thickness expansion rate (%) = (T ₂ / T ₁ ) × 100 (1)

The thickness T ₁ of the high temperature and high humidity held before the outermost metallic aluminum film is first prepare a sample obtained by solidifying a high temperature and high humidity held before the outer cover material outer periphery a curable resin (Marumoto Struers manufactured cold embedding resin epo fix) Then, the fixed outer packaging material is cut in the thickness direction with a diamond knife to expose the cross section. Next, an image with a magnification of 50,000 times of the exposed cross section was obtained using a scanning electron microscope (Hitachi High-Tech SU-8000), and the thickness of the five points of the outermost metallic aluminum film in the image was at least the width. Measured with an interval of 200 nm or more in the direction. The above operation is performed on five samples, and the average of a total of 25 measurement values is defined as the thickness T ₁ of the outermost metallic aluminum film before holding at high temperature and high humidity.

The thickness T ₂ of the outermost metallic aluminum film after high temperature and high humidity retention, the outer cover material, temperature 70 ° C., after holding for 500 hours in a thermo-hygrostat in an atmosphere of a humidity of 90% RH high-temperature and high-humidity retention measured in the previous outermost metallic aluminum film the same method as the thickness of 5 samples, the average of the total of 25 measurements, and the thickness T ₂ of the outermost metallic aluminum film after high temperature and high humidity retention.

Further, the outer cover material of the present disclosure, the initial water vapor permeability of 0.1g ^/ (m 2 · day) or less, preferably 0.05g ^/ (m 2 · day) or less, particularly 0.01g ^/ (m 2 · day) The following is preferable. The initial water vapor permeability refers to the water vapor permeability before being held in an atmosphere at a temperature of 70 ° C. and a humidity of 90%.

In addition, the outer packaging material of the present disclosure has a water vapor permeability of 0.5 g / (m ² · day) or less after being held for 500 hours in an atmosphere at a temperature of 70 ° C. and a humidity of 90% RH, and in particular, 0.3 g / (m ² · Day) or less, and particularly preferably 0.1 g / (m ² · day) or less. The water vapor permeability after holding for 500 hours in an atmosphere at a temperature of 70 ° C. and a humidity of 90% may be referred to as “water vapor permeability after holding at high temperature and high humidity”.

  Since the water vapor permeability before and after holding the high temperature and high humidity of the outer packaging material of the present disclosure is in the above range, even in a high temperature and high humidity environment, the outer packaging material alone can exhibit good water vapor barrier performance for a long period of time. In the vacuum heat insulating material using the outer packaging material of the present disclosure, it becomes possible to prevent water vapor from entering the inside, and the heat insulating performance can be maintained for a long time in a high temperature and high humidity environment. Specifically, as will be described in the examples described later, the ratio of the thermal conductivity of the vacuum heat insulating material after being held for 500 hours in an atmosphere at a temperature of 70 ° C. and a humidity of 90% with respect to the initial thermal conductivity is reduced. be able to.

The initial water vapor permeability of the outer packaging material can be measured under the conditions of a temperature of 40 ° C. and a relative humidity difference of 90% RH using a water vapor permeability measuring device in accordance with ISO 15106-5: 2015 (differential pressure method). it can. The initial water vapor permeability can be measured by the following procedure. First, among the two outermost layers facing the thickness direction of the outer packaging material cut to a desired size, the surface of the outermost layer on the side opposite to the heat-weldable film that is one outermost layer has high humidity. It is attached between the upper chamber and the lower chamber of the apparatus so as to be on the side (water vapor supply side), and has a permeation area of about 50 cm ² (permeation region: circular with a diameter of 8 cm), a temperature of 40 ° C., and a relative humidity difference of 90 Measurement is performed under the condition of% RH. As the water vapor transmission rate measuring apparatus, for example, “DELTAPERM” manufactured by Technolox, UK can be used.

  Further, the water vapor permeability after holding the packaging material at high temperature and high humidity is determined by using a water vapor permeability measuring device in accordance with JIS K7129: 2008 (Appendix B: Infrared sensor method, the same shall apply hereinafter). It can be measured under the conditions of 40 ° C. and a relative humidity difference of 90% RH. The measurement of water vapor permeability after holding at high temperature and high humidity can be performed by the following procedure. First, two rectangular outer packaging materials each having a width of 21.0 cm and a length of 29.7 cm were prepared and stacked so that the respective heat-weldable films faced each other, and the end portions (of the outer packaging material) A region having a width of 10 mm at a position 1 cm from the outer edge) is thermally welded at atmospheric pressure and joined to obtain a test piece. The heating temperature at the time of heat welding is set to a temperature suitable for a resin constituting a film that can be heat-sealed within a range of 170 ° C to 240 ° C. The test piece is in a state in which nothing is contained inside and the pressure is not reduced. The test piece was held in an atmosphere at a temperature of 70 ° C. and a humidity of 90% RH for 500 hours, and the non-heat-welded region of the test piece after holding was cut out in a size of 9 cm wide × 9 cm long. The water vapor permeability of the outer packaging material is measured by the same measurement method and conditions as the initial water vapor permeability. For example, “PERMATRAN” manufactured by MOCON, USA can be used as the water vapor transmission rate measuring apparatus.

  The measurement of the water vapor permeability at the initial stage and after holding at high temperature and high humidity is performed for at least three samples under one condition, and the average of the measured values is taken as the value of the water vapor permeability under that condition. Hereinafter, the water vapor permeability after the initial stage in the present disclosure and after holding at high temperature and high humidity can be measured by the above-described methods.

The outer packaging material of the present disclosure preferably has an initial oxygen permeability of 0.1 cc / (m ² · day · atm) or less, and more preferably 0.05 cc / (m ² · day · atm) or less. . The initial oxygen permeability refers to the oxygen permeability before holding for 500 hours in an atmosphere at a temperature of 70 ° C. and a humidity of 90% RH.

In addition, the outer packaging material of the present disclosure preferably has an oxygen permeability of 0.3 cc / (m ² · day · atm) or less after being held for 500 hours in an atmosphere at a temperature of 70 ° C. and a humidity of 90% RH, It is preferably 0.1 cc / (m ² · day · atm) or less. The oxygen permeability after holding for 500 hours in an atmosphere of temperature 70 ° C. and humidity 90% RH may be referred to as oxygen permeability after holding at high temperature and high humidity.

  Since the oxygen permeability after holding the high temperature and high humidity of the outer packaging material of the present disclosure is within the above range, even in a high temperature and high humidity environment, the outer packaging material alone can exhibit good oxygen barrier performance for a long period of time. In the vacuum heat insulating material using the outer packaging material of the present disclosure, it becomes possible to prevent the ingress of oxygen into the inside, and the heat insulating performance can be maintained for a long time in a high temperature and high humidity environment.

The oxygen permeability of the outer packaging material of the present disclosure at the initial stage and after holding at high temperature and high humidity is JIS K7126-2: 2006 (plastic-film and sheet-gas permeability test method-part 2: isobaric method, appendix A: With reference to the oxygen gas permeability test method by the electrolytic sensor method, the state of the carrier gas and the test gas can be adjusted to a temperature of 23 ° C. and a humidity of 60% RH using an oxygen gas permeability measuring device. . As the oxygen gas permeability measuring device, for example, “OXTRAN” manufactured by MOCON of the United States can be used.
The initial measurement of oxygen permeability is the opposite of the heat-weldable film that is one of the outermost layers of the two outermost layers facing the thickness (lamination) direction of the outer packaging material cut to the desired size. The outermost layer on the side is mounted in the apparatus so as to be in contact with oxygen gas, and the state of the carrier gas and the test gas is 23 ° C., humidity with a permeation area of about 50 cm ² (permeation region: a circle with a diameter of 8 cm). Adjust to 60% RH condition. During the measurement, the carrier gas is purged by supplying the carrier gas at a flow rate of 10 cc / min for 60 minutes or more. As the carrier gas, nitrogen gas containing about 5% hydrogen can be used. After purging, the test gas is allowed to flow through the apparatus, and measurement is performed after 12 hours have been secured as the time from the start of flowing until the equilibrium state is reached. The test gas uses at least 99.5% dry oxygen.

  Moreover, the oxygen permeability after holding at high temperature and high humidity can be performed by the following procedure. First, two rectangular outer packaging materials each having a width of 21.0 cm and a length of 29.7 cm were prepared and stacked so that the respective heat-weldable films faced each other, and the end portions (of the outer packaging material) A region having a width of 10 mm at a position 1 cm from the outer edge) is thermally welded at atmospheric pressure and joined to obtain a test piece. The heating temperature at the time of heat welding is set to a temperature suitable for a resin constituting a film that can be heat-sealed within a range of 170 ° C to 240 ° C. The test piece was in a state in which nothing was contained inside and the pressure was not reduced. After holding the test piece in an atmosphere of temperature 70 ° C. and humidity 90% RH for 500 hours, the non-heat-welded region of the test piece was cut out in a size of 9 cm wide × 9 cm long, and the oxygen of the cut outer packaging material The permeability is measured by the same measurement method and conditions as the initial oxygen permeability.

  The measurement of oxygen permeability at the initial stage and after holding at high temperature and high humidity is performed for at least three samples under one condition, and the average of those measured values is taken as the value of oxygen permeability under that condition. Hereinafter, the oxygen permeability after the initial stage in the present disclosure and after holding at high temperature and high humidity can be measured by the above-described methods.

  The outer packaging material of the present disclosure is preferably as the moisture content after holding for 2 hours in an atmosphere of a temperature of 70 ° C. and a humidity of 90% RH, for example, preferably 10,000 ppm or less, and more preferably 9000 ppm or less. By setting the moisture content of the outer packaging material within the above range, it is possible to suppress the amount of moisture absorbed by the resin layer of the gas barrier film, the adhesive layer, the protective film, and the like in a high temperature and high humidity environment. Therefore, the amount of water vapor that comes into contact with the gas barrier film can be reduced, and the reaction between metal aluminum and water vapor can be suppressed.

  The moisture content of the outer packaging material can be calculated from the obtained moisture content value by measuring the moisture content of the outer packaging material by the following method. The water content of the outer packaging material can be measured by the coulometric titration method of the Karl Fischer method in accordance with JIS K0113: 2005. As the measuring device, for example, an integrated Karl Fischer moisture meter (Karl Fischer moisture meter MKC-510 and moisture vaporizer ADP-611 integrated interlocking type, both manufactured by Kyoto Electronics Industry Co., Ltd.) can be used. The water content can be measured by the following procedure. First, a pretreatment is performed in which the outer packaging material is held for 2 hours in an atmosphere of 70 ° C. and 90% humidity. The outer packaging material after the pretreatment is stored in an aluminum pouch until measurement. Next, a plurality of 10 mm × 50 mm sizes are cut out from the pre-processed outer packaging material, and the cut outer packaging material is placed on a quartz sample boat so that the sample weight is about 0.5 g. Set in the heating tube (preparation room). While flowing the carrier gas (nitrogen) at 250 mL / min, the heating tube (preparation chamber) is aged (back purge) for 180 seconds, and then the heating unit at a set temperature of 150 ° C. is aged for 120 seconds. Thereafter, the sample boat is moved to a heating section and titrated for 600 seconds, and the water content is measured in an ambient environment at a temperature of 20 ° C. and a dew point of −50 ° C. The measurement is performed within at least one hour after taking out from the pretreated atmosphere.

The moisture content of the outer packaging material can be defined by the following mathematical formula (2) based on the value of the moisture content obtained by the above method.
Water content (ppm) = (G / M _S ) × 10 ⁶ (2)
(In the above formula (2), G is the water content (g) detected by the above method, and M _s is the sample weight (g) on the sample boat.)

  The moisture content can be measured for at least three samples collected from one outer packaging material, and the average of the measured values can be used as the moisture content value under the conditions.

  The outer packaging material of the present disclosure preferably has an ash content greater than 1.0% by mass, more preferably 1.3% by mass or more, and particularly preferably 1.5% by mass or more. The ash content of the outer packaging material of the present disclosure is preferably 20% by mass or less, more preferably 10% by mass or less, and particularly preferably 5% by mass or less. Here, the ash content of the outer packaging material refers to the ratio of the non-combustible component remaining after the outer packaging material burns out in the mass of the entire outer packaging material, and the above ratio approximates the content of inorganic matter in the entire outer packaging material. Here, the inorganic substance refers to an inorganic compound such as a metal (including an alloy), a compound of a metal element, and a compound of a non-metal element.

  The gas barrier performance of the outer packaging material is exhibited mainly by a layer containing an inorganic substance (inorganic substance layer). For this reason, the gas barrier performance of an outer packaging material can be prescribed | regulated by the content rate of the inorganic substance which occupies for the whole outer packaging material. Here, as a method for adjusting the content of the inorganic substance, for example, a method of specifying the thickness of the inorganic layer is conceivable. However, for example, the gas barrier film has a different film density depending on the formation conditions, and since the inorganic layer may contain an organic compound, the inorganic content in the entire outer packaging material is simply determined as the inorganic layer. It is difficult to specify only by the thickness of the film. The ash content of the outer packaging material can be used as a comprehensive index when the inorganic material is used in a complicated manner.

  When the ash content is less than the above-described range, the content of the inorganic substance in the entire outer packaging material is too small, and thus good initial gas barrier performance may not be obtained. On the other hand, when the ash content is larger than the above-described range, the content of the inorganic matter in the entire outer packaging material is increased, so that heat bridge is generated in the vacuum heat insulating material using the outer packaging material and the thermal conductivity is increased. There is a case.

  In the present disclosure, the ash content is measured using a thermogravimetric / differential thermal analyzer (TG-DTA), and after measuring the mass of the measurement sample, the heating rate is 10 ° C./min in an aluminum pan and in an air atmosphere. After heating from room temperature to 600 ° C., the sample is ashed by heating at 600 ° C. for 30 minutes as it is, and the mass after heating with respect to the mass before heating is expressed as a percentage. As the thermogravimetric / differential thermal simultaneous analyzer, for example, TG8120 manufactured by Rigaku Corporation can be used.

B. Configuration The outer packaging material of the present disclosure includes a heat-weldable film, and one or more gas barrier films including a resin base material and a gas barrier film disposed on one surface side of the resin base material, and at least 1 The gas barrier film is a metal aluminum film.

1. Gas Barrier Film The gas barrier film has a resin base material and a gas barrier film disposed on one surface side of the resin base material.
Hereinafter, among the gas barrier films, a gas barrier film whose gas barrier film is a metal aluminum film will be described as a first gas barrier film, and a gas barrier film whose gas barrier film is other than a metal aluminum film will be described as a second gas barrier film.

(1) First gas barrier film The first gas barrier film has a resin base material and a gas barrier film disposed on one surface side of the resin base material, and the gas barrier film is a metal aluminum film.

(A) Gas barrier film (metal aluminum film)
The metal aluminum film is a film formed of metal aluminum.

  The thickness of the metal aluminum film is not particularly limited as long as the desired gas barrier performance can be exhibited in the entire outer packaging material, but is preferably in the range of 20 nm or more and 200 nm or less, for example, in the range of 40 nm or more and 180 nm or less. It is preferable that it is in the range of 60 nm or more and 150 nm or less. Here, the “thickness of the metal aluminum film” refers to the thickness of the metal aluminum film before being held for 500 hours in an atmosphere at a temperature of 70 ° C. and a humidity of 90% RH, and can be measured by the measurement method described above. .

  The metal aluminum film may be a vapor deposition film formed by a vapor deposition method or a coat film formed by a coating method such as coating. When the metal aluminum film is a vapor deposition film, it may be formed by single vapor deposition or the like, or may be formed by multiple vapor deposition.

  The metal aluminum film can be formed using a conventionally known method such as a coating method, a vapor deposition method, or a pressure bonding method.

(B) Resin base material The resin constituting the resin base material includes known resins used for gas barrier films. Specific examples of the resin include polyolefin resin, polyester resin, cyclic polyolefin resin, polystyrene resin, polyvinyl chloride resin, acrylonitrile-styrene copolymer (AS) resin, acrylonitrile-butadiene-styrene copolymer (ABS) resin, Examples include polymethyl methacrylate (PMMA) resin, polycarbonate resin, polyvinyl alcohol resin, saponified ethylene-vinyl ester copolymer, polyamide resins such as various nylons, polyimide resins, polyurethane resins, acetal resins, and cellulose resins. The resin base material can contain one or more of the various resins described above.

  Especially, it is preferable that resin which comprises the said resin base material is hydrophobic resin. This is because the water absorption is low and deterioration of the metal aluminum film due to water vapor contained in the resin base material can be suppressed. Specific examples of hydrophobic resins include polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyethylene resins, polypropylene resins, cyclic polyolefin resins, polyimide resins, polyvinyl chloride resins, polystyrene resins, and polymethyl methacrylate. Examples thereof include resins, polycarbonate resins, acrylonitrile-styrene copolymers, and acrylonitrile-butadiene-styrene copolymers.

  The resin base material can be a resin film containing as a main component at least one selected from the resin group described above. The resin film may be unstretched or may be uniaxially or biaxially stretched. Moreover, the said resin base material may have transparency and does not need to have it.

  Here, the main component means that a predetermined resin is contained to such an extent that the above-mentioned characteristics after holding at high temperature and high humidity are satisfied. Specifically, the content of the predetermined resin in the resin film is 50% by mass or more, preferably 90% by mass or more, and the resin film is composed of only the predetermined resin. Is preferred. When two or more resins of the same type are included, the main component means that the sum of two or more resins of the same type is within the above range. Specifically, when the resin film contains two types of polyester resins, a polyethylene terephthalate resin and a polybutylene terephthalate resin, the resin film is mainly composed of a polyester resin. It means that the total content of the butylene terephthalate resin is within the above-described range. The same applies to other resins than the polyester resin.

  That is, as a resin film that can be suitably used as the resin substrate, polyester resin film, polypropylene resin film, cyclic polyolefin resin film, polyimide resin film, polyvinyl chloride resin film, polystyrene resin film, polymethyl methacrylate resin Examples thereof include a film, a polycarbonate resin film, an acrylonitrile-styrene copolymer film, and an acrylonitrile-butadiene-styrene copolymer film. Especially, it is preferable that the said resin base material is a polyester resin film. This is because hygroscopicity and heat stretchability are small and relatively inexpensive.

  The resin base material may contain an additive. Examples of the additive include a lubricant, a crosslinking agent, an antioxidant, an ultraviolet absorber, a light stabilizer, a filler, a reinforcing agent, an antistatic agent, a pigment, and a modifying resin. The resin base material may be subjected to a surface treatment. This is because the adhesion to the gas barrier film can be improved.

  The thickness of the resin substrate is not particularly limited as long as it can support the gas barrier film, but can be, for example, in the range of 6 μm to 200 μm, and preferably in the range of 9 μm to 100 μm.

(C) Others The first gas barrier film only needs to have a metal aluminum film on at least one surface of the resin base material, and has a metal aluminum film on both surfaces positioned in the thickness direction of the resin base material. Also good.
When the first gas barrier film farthest from the heat weldable film has a metal aluminum film on both surfaces of the resin base material, the metal aluminum film furthest away from the heat weldable film is the first The metal aluminum film arrange | positioned on the opposite side to the film side which can be heat-welded with respect to the resin base material of 1 gas barrier film.

  The first gas barrier film can have an overcoat layer on the surface of the metal aluminum film opposite to the resin base material. It is because the gas barrier performance of the first gas barrier film can be improved by having the overcoat layer. Examples of the overcoat layer include a film having a M-O-P bond (where M represents a metal atom, O represents an oxygen atom, and P represents a phosphorus atom), a polycarboxylic acid polymer, And a mixed compound film containing a metal element, an oxygen element, and a hydrophilic group-containing resin. Since these films will be described in detail in the section of “(2) Second gas barrier film (a) gas barrier film” described later, description thereof is omitted here. Although the thickness of an overcoat layer is not specifically limited, For example, it can be in the range of 50 nm or more and 500 nm or less.

(2) Second gas barrier film The second gas barrier film has a resin base material and a gas barrier film disposed on one surface side of the resin base material, and the gas barrier film is other than a metal aluminum film.

(A) Gas barrier film The gas barrier film in the second gas barrier film can be a film containing an inorganic substance other than metallic aluminum. Examples of the film containing an inorganic substance other than metal aluminum include, for example, a metal film other than metal aluminum, an inorganic compound film, and a M-O-P bond (wherein M represents a metal atom, O represents an oxygen atom, and P represents A film having a phosphorus atom), a film containing a polyvalent metal salt of a polycarboxylic acid polymer, a mixed compound film containing a metal element, an oxygen element, and a hydrophilic group-containing resin.

(I) Metal film The metal constituting the metal film may be any metal other than metal aluminum, and examples thereof include metals such as stainless steel, titanium, nickel, iron, copper, and alloys containing these metals.

The metal film may be a vapor deposition film formed by a vapor deposition method, or may be a coat film formed by a coating method such as coating. When it is a vapor deposition film, it may be formed by single vapor deposition etc. and may be formed by multiple vapor deposition.
The metal film can be formed using a conventionally known method such as a coating method, a vapor deposition method, or a pressure bonding method.

(Ii) Inorganic compound film Examples of the inorganic compound constituting the inorganic compound film include metal elements such as silicon, aluminum, magnesium, calcium, potassium, tin, sodium, titanium, boron, yttrium, zirconium, mucerium, and zinc. Examples include metal element oxides, oxynitrides, nitrides, oxycarbides, and oxycarbonitrides. Specifically, silicon oxide such as SiO ₂ , aluminum oxide such as Al ₂ O ₃ , magnesium oxide, titanium oxide, tin oxide, silicon zinc alloy oxide, indium alloy oxide, silicon nitride, Examples thereof include aluminum nitride, titanium nitride, silicon oxynitride, and silicon oxide zinc. An inorganic compound may be used independently and may mix and use the above-mentioned material in arbitrary ratios.

The inorganic compound film may be a vapor deposition film formed by a vapor deposition method or a coat film formed by a coating method such as coating. When it is a vapor deposition film, it may be formed by single vapor deposition etc. and may be formed by multiple vapor deposition.
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.

(Iii) Film having M-O-P bond As a film having M-O-P bond (where M represents a metal atom, O represents an oxygen atom, and P represents a phosphorus atom), For example, the film | membrane containing the reaction product of a metal oxide and a phosphorus compound is mentioned.

  Examples of the metal oxide include oxides of metals having a valence of 2 or more. Specifically, metals of Group 2 of the periodic table such as magnesium and calcium; Group 12 of the periodic table of zinc and the like. Examples include metals of Group 13 of the periodic table such as aluminum; metals of Group 14 of the periodic table such as silicon; and oxides of metals such as transition metals such as titanium and zirconium. Among these, aluminum oxide (alumina) is preferable.

  Examples of the phosphorus compound include phosphoric acid, polyphosphoric acid, phosphorous acid, phosphonic acid, and derivatives thereof. Of these, phosphoric acid is preferred. Specific reaction products of metal oxides and phosphorus compounds can be the same as the reaction products disclosed in, for example, Japanese Patent Application Laid-Open No. 2011-226644.

The presence of the M-O-P bond appears in the infrared absorption spectrum (measured wave number range; 800 cm ⁻¹ or more and 1400 cm ⁻¹ or less), and the maximum infrared absorption peak is in the range of 1080 cm ⁻¹ or more and 1130 cm ⁻¹ or less. This can be confirmed. The method of measuring the infrared absorption spectrum is not particularly limited, for example, a measurement method by total reflection measurement method (ATR method), a method of scraping a sample from the gas barrier film of the outer packaging material, and measuring the infrared absorption spectrum by the KBr method, A measuring method or the like can be used for the collected sample by micro infrared spectroscopy.

  In addition, as a gas barrier film which has a gas barrier film | membrane which has a MOPP coupling | bonding, Kuraray Co., Ltd. Clarista CF etc. are mentioned.

(Iv) Film containing polyvalent metal salt of polycarboxylic acid polymer The film containing polyvalent metal salt of polycarboxylic acid polymer is cross-linked by polyvalent metal ions between the carboxyl groups of polycarboxylic acid polymer. Have The polyvalent metal salt of the polycarboxylic acid polymer is a reaction product of a polycarboxylic acid polymer and a polyvalent metal compound.

The presence of polyvalent metal salt of a polycarboxylic acid polymer, in the range of ^{1490cm -1 ~1659cm} -1 in the infrared absorption spectrum may be confirmed by the appearance of the absorption peak having an absorption maximum in the vicinity of 1560 cm ^-1 . The peak is a peak of C═O stretching vibration attributed to a carboxyl group (—COO ⁻ ) forming a salt with a polyvalent metal. Usually, salts of carboxyl groups (-COO ^-) C = O stretching vibration attributable to ^the infrared wave number range of 1490cm ^-1 ~1659cm -1, giving an absorption peak having an absorption maximum in the vicinity of 1560 cm ^-1. The infrared absorption spectrum can be measured by a transmission method, an ATR method (attenuated total reflection method), a KBr pellet method, a diffuse reflection method, a photoacoustic method (PAS method), or the like.

  Examples of the polycarboxylic acid-based polymer include polymers having two or more carboxyl groups in the molecule, such as polyacrylic acid, polymethacrylic acid, polymaleic acid, polyitaconic acid, acrylic acid-methacrylic acid copolymer, and the like. The homopolymer or copolymer of the monomer which has can be mentioned.

  The polyvalent metal compound is not particularly limited as long as the carboxyl group of the polycarboxylic acid polymer can be cross-linked. For example, alkaline earth metal, Group 8 metal, Group 11 metal, Periodic table 12 Examples thereof include hydroxides, carbonates, carboxylates and the like of metals such as Group metals and Group 13 metals of the periodic table. Specifically, magnesium (Mg), calcium (Ca), barium (Ba), zinc (Zn), copper (Cu), cobalt (Co), nickel (Ni), aluminum (Al), iron (Fe), etc. Or a metal of these metals, oxides, hydroxides, halides, carbonates, phosphates, phosphites, hypophosphites, sulfates or sulfites of these metals. At least 1 type is used for these, and even 1 type may be used or 2 or more types may be used together.

  Examples of the polyvalent metal salt of the polycarboxylic acid polymer include zinc acrylate, zinc methacrylate, sodium acrylate, potassium acrylate, magnesium acrylate, calcium acrylate, aluminum acrylate, sodium methacrylate, methacrylic acid. Examples include potassium acid, magnesium methacrylate, and calcium methacrylate.

  In addition, the film containing the polyvalent metal salt of the polycarboxylic acid polymer may contain a binder resin. As the binder resin, a hydrophilic binder or a hydrophobic binder can be used. Examples of the hydrophilic binder include polyvinyl alcohol, polyvinyl pyrrolidone, methyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cell source, sodium alginate, ethylene-vinyl alcohol copolymer, starch, dextran, gelatin, and modified products thereof. , At least one selected from these groups can be used.

  A film containing a polyvalent metal salt of a polycarboxylic acid polymer is, for example, coated with a solution for forming a barrier layer in which a carboxylic acid resin, a polyvalent metal compound and a binder resin are dissolved in a solvent, and then irradiated with an electron beam. Can be formed. Moreover, the polycarboxylic acid polymer layer and the polyvalent metal compound-containing layer can be laminated adjacent to each other, and a film containing a polyvalent metal salt of the polycarboxylic acid polymer can be formed by an interlayer reaction.

  Examples of the gas barrier film having a gas barrier film containing a reaction product of a polycarboxylic acid polymer and a polyvalent metal compound include Besela (registered trademark) manufactured by Toppan Printing Co., Ltd.

(V) Mixed Compound Film Containing Metal Element, Oxygen Element, and Hydrophilic Group-Containing Resin A mixed compound film containing a metal element, oxygen element, and hydrophilic group-containing resin has a general formula R ¹ _n M (OR ² ) _m (In the formula, R 1 and R ² represent an organic group having 1 to 8 carbon atoms, M represents a metal atom, n represents an integer of 0 or more, and m represents an integer of 1 or more. , N + m represents the valence of M.), and includes a sol-gel compound obtained by polycondensation by a sol-gel method. It is a membrane. Hereinafter, a mixed compound film containing a metal element, an oxygen element, and a hydrophilic group-containing resin is referred to as a sol-gel compound film.

  The sol-gel compound film may have a cross-linked C—O—M bond via oxygen (O) between the carbon atom (C) in the hydrophilic group-containing resin and the metal atom (M) in the metal alkoxide. it can.

The metal alkoxide is represented by the general formula R ¹ _n M (OR ² ) _m and may be a partial hydrolyzate of alkoxide, a hydrolysis condensate of alkoxide, or the like. Examples of M include silicon, zirconium, titanium, and aluminum. Examples of R ¹ include a methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, sec-butyl group, t-butyl group, n-hexyl group, Examples thereof include an n-octyl group. Examples of R ² include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, a sec-butyl group, and the like. When a plurality of (OR ² ) are present in the same molecule, (OR ² ) may be the same or different.

Of these, the metal alkoxide is preferably an alkoxysilane containing silicon. Examples of the alkoxysilane include tetramethoxysilane Si (OCH ₃ ) ₄ , tetraethoxysilane Si (OC ₂ H ₅ ) ₄ , tetrapropoxysilane Si (OC ₃ H ₇ ) ₄ , tetrabutoxysilane Si (OC ₄ H ₉ ) ₄ Etc.

The hydrophilic group-containing resin is a resin having a hydrophilic group such as a hydroxy group (—OH), a carboxy group (—COOH), an amino group (—NH ₂ ), a carbonyl group (> CO), or a sulfo group (—SO ₃ H). It is. Examples of the hydrophilic group-containing resin include a polyvinyl alcohol resin and an ethylene / vinyl alcohol copolymer. These may be used alone or in combination.

  Examples of the sol-gel compound include a sol-gel compound containing Si, O, and PVA, which is a polycondensate of tetraethoxysilane (TEOS) and polyvinyl alcohol (PVA).

  For example, the sol-gel compound film is coated with a solution for forming a barrier layer prepared by mixing a metal alkoxide, a hydrophilic group-containing resin, a silane coupling agent, a sol-gel method catalyst, an acid, water, an organic solvent, and the like. It can be formed by heat treatment.

  Other details of the sol-gel compound film not described in the present disclosure can be the same as the details disclosed in, for example, Japanese Patent No. 5568897 and Japanese Patent Application Laid-Open No. 2017-61956.

(Vi) Others The thickness of the gas barrier film in the second gas barrier film is not particularly limited as long as the desired gas barrier performance can be exhibited in the entire outer packaging material, and can be set as appropriate according to the type of the gas barrier film. The thickness of the gas barrier film can be, for example, in the range of 5 nm to 500 nm, in particular, in the range of 10 nm to 400 nm, and in particular in the range of 20 nm to 300 nm. When the gas barrier film is a metal film or an inorganic compound film, the upper limit of the thickness of the gas barrier film can be further reduced. For example, the thickness of the metal film or the inorganic compound film is in the range of 5 nm to 200 nm, It can be in the range of 10 nm or more and 150 nm or less.

(B) Resin base material The resin base material in the second gas barrier film can be the same as the resin base material described in the section “(1) First gas barrier film”, and the description thereof is omitted here. . Among them, the second gas barrier film adjacent to the metal aluminum film of the first gas barrier film preferably has a resin base material mainly composed of a hydrophobic resin.

(C) Overcoat layer When the gas barrier film is a metal film or an inorganic compound film, the second gas barrier film may have an overcoat layer on the opposite side of the gas barrier film from the resin substrate. This is because the gas barrier performance of the second gas barrier film can be further improved. As the overcoat layer, a layer having a M-O-P bond, a layer containing a polycarboxylic acid polymer polyvalent metal salt, a mixed compound layer containing a metal element, an oxygen element and a hydrophilic group-containing resin (sol gel Compound layer) and the like. Since the details of each layer have been described in the section “(a) Gas barrier film”, description thereof is omitted here. The thickness of the overcoat layer can be the same as the thickness of the overcoat layer in the first gas barrier film.

  The 2nd gas barrier film should just have a gas barrier film on the at least one surface of a resin base material, and may have a gas barrier film on both surfaces located in the thickness direction of a resin base material, respectively.

2. Heat-weldable film A heat-weldable film is a layer that can be welded by heating and bears one of the outermost surfaces facing each other in the thickness direction (stacking direction) of the outer packaging material.
The heat-weldable film is in contact with the core material when forming the vacuum heat insulating material using the outer packaging material of the present disclosure, and when the core material is sealed, the end portion of the facing outer packaging material is It is a member to join.

For the heat-weldable film, a material that can be melted and fused by heating is used. As such a material, a thermoplastic resin is preferably used. Examples of the thermoplastic resin include polyolefin resins, polyester resins, polyvinyl acetate resins, polyvinyl chloride resins, poly (meth) acrylic resins, urethane resins, polyvinyl alcohol resins, and ethylene-vinyl alcohol copolymers. (EVOH) resin, polyphenylene sulfide (PPS) resin, tetrafluoroethylene (C ₂ F ₄ ) / ethylene (C ₂ H ₄ ) copolymer (ETFE) resin, and the like.

The heat-weldable film is preferably a film mainly composed of the above-described thermoplastic resin. Specifically, polyethylene resin films such as polyethylene such as linear short chain branched polyethylene (LLDPE) and high density polyethylene (HDPE) and unstretched polypropylene (CPP), polyethylene terephthalate (PET), polyethylene naphthalate (PEN). ), Polyester resin films such as polybutylene terephthalate (PBT), polyvinyl acetate resin films, polyvinyl chloride resin films, poly (meth) acrylic resin films, urethane resin films, polyvinyl alcohol resin films, ethylene- vinyl alcohol copolymer (EVOH) resin films, polyphenylene sulfide (PPS) resin film, tetrafluoroethylene (C ₂ F ₄₎ · ethylene (C ₂ H ₄₎ a copolymer (ETFE) resin film is ani It is. A main component means the component which occupies 50 mass% or more in the film in which heat welding is possible.

  The heat-weldable film can be appropriately selected from the above resin films according to the melting point to be set. For example, a resin film mainly composed of a low melting point resin such as a linear short chain branched polyethylene (LLDPE) has high versatility, and the melting point of a heat-weldable film can be set low, so that the temperature is relatively low. Can be suitably used from the viewpoint that heat welding is possible. In addition, for resin films mainly composed of a resin having a melting point of 145 ° C. or higher, such as PP resin, EVOH resin, PET resin, PBT resin, ETFE resin, PPS resin, etc., the melting point of the heat-weldable film is set to 145 ° C. or higher. The film can be suitably used from the viewpoint of being able to prevent thermal deterioration of the heat-weldable film and obtaining a vacuum heat insulating material that can withstand use in a higher temperature environment.

  The heat-weldable film may contain other materials such as an antiblocking agent, a lubricant, a flame retardant, and a filler in addition to the above-described resin.

  The melting point of the heat-weldable film is preferably 50 ° C. or higher, more preferably 80 ° C. or higher, more preferably 100 ° C. or higher, and particularly preferably 145 ° C. or higher, although it depends on the material. The melting point is preferably 300 ° C. or lower, more preferably 290 ° C. or lower, more preferably 280 ° C. or lower. By setting the melting point of the thermally weldable film within the above range, it is possible to suppress peeling of the sealing surface of the outer packaging material under the usage environment of the vacuum heat insulating material manufactured using the outer packaging material of the present disclosure. Can withstand use in high temperature environments. Moreover, when manufacturing a vacuum heat insulating material using the outer packaging material of this indication, the heat deterioration of the gas barrier film or the film which can be heat-welded can be suppressed by the heating for sealing. Furthermore, the heat-weldable film can be made difficult to expand or contract even when used in a high temperature environment for a long period of time by increasing the melting point.

  The melting point of the heat-weldable film in the outer packaging material of the present disclosure can be measured by the following method using a differential scanning calorimeter (DSC). First, a heat-weldable film is peeled off from the outer packaging material to obtain a measurement sample of about 10 mg. This measurement sample was put in an aluminum cell, and the temperature was raised from 20 ° C. to 300 ° C. at a heating rate of 10 ° C./min under a nitrogen atmosphere using a differential scanning calorimeter (DSC204, manufactured by NETZSCH). Hold for 10 minutes. Furthermore, after cooling to 20 ° C. at a temperature lowering rate of 10 ° C./min and holding at that temperature for 10 minutes, the temperature is raised again to 300 ° C. at a temperature rising rate of 10 ° C./min (second temperature increase). The intersection of the tangent at the melting point observed at the second temperature rise and the baseline of the DSC curve on the lower temperature side than the melting point can be the melting point of the heat-weldable film.

  The thickness of the heat-weldable film is not particularly limited, but is, for example, in the range of 15 μm or more and 100 μm or less, preferably in the range of 25 μm or more and 90 μm or less, more preferably in the range of 30 μm or more and 80 μm or less. be able to. By making the thickness of the heat-weldable film within the above range, it is possible to suppress a decrease in gas barrier properties of the outer packaging material, and when joining the two outer packaging materials in the production of the vacuum heat insulating material, Adhesive strength can be obtained.

3. Protective film The outer packaging material of this indication can have a protective film. The protective film can be distinguished from the above-described gas barrier film in that a gas barrier film or an overcoat layer is not disposed on either side.

The protective film can be a layer that bears the outermost surface on the opposite side of the heat-weldable film in the thickness direction (laminating direction) of the outer packaging material of the present disclosure, and damages the components of the outer packaging material other than the protective film And can be protected from deterioration.
Moreover, by having a protective film, contact between the metal aluminum film and external water vapor and hydroxylation of the metal aluminum film can be suppressed.

  As the protective film, a resin film can be used, and among them, a resin film having a higher melting point than a heat-weldable film is preferable. Examples of the resin film include polyester resins such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and polybutylene terephthalate (PBT), polyamide resins, polypropylene resins, polyurethane resins, amino resins, silicone resins, epoxy resins, and polyimides. Thermosetting resins such as (PI), polyvinyl chloride (PVC), polycarbonate (PC), polystyrene (PS), polyvinyl alcohol (PVA), ethylene / vinyl acetate copolymer (EVAL), polyacrylonitrile (PAN), Examples thereof include a resin film such as cellulose nanofiber (CNF). The protective film may be stretched or non-stretched. Of these, polyester resin films and polypropylene resin films having relatively low water absorption are preferred.

  The protective film may contain other materials such as an antiblocking agent, a lubricant, a flame retardant, and a filler.

  Although the thickness of the said protective film is not specifically limited, For example, it can be in the range of 5 micrometers or more and 80 micrometers or less.

4). Adhesive Layer The outer packaging material of the present disclosure can have an adhesive layer between members constituting the outer packaging material. The members constituting the outer packaging material include, for example, between a heat-weldable film and a gas barrier film, between a gas barrier film and another gas barrier film adjacent thereto, and between a gas barrier film and a protective film. It is done.

  The adhesive layer can be formed using a known adhesive used for lamination. Especially, it is preferable that the said contact bonding layer contains hydrophobic resin as a main component. When the resin contained in the adhesive layer is hydrophilic, the adhesive layer easily absorbs water vapor in the outside air, and when laminating the gas barrier film having the metal aluminum film and another member via the adhesive layer, the metal aluminum This is because when the film is in contact with the adhesive layer, the hydroxylation reaction of the metal aluminum film proceeds due to moisture contained in the adhesive layer, and the film tends to expand. Examples of the hydrophobic resin that is a main component of the adhesive layer include polyester resins and polyurethane resins.

  The adhesive that forms the adhesive layer may be any adhesive as long as it contains the above-described resin, and examples thereof include a pressure-sensitive adhesive, a thermoplastic adhesive, and a curable adhesive.

5. Others The outer packaging material of the present disclosure only needs to have one or more gas barrier films, and the number of gas barrier films is not particularly limited as long as it can have the above-described characteristics. It can be set appropriately. The number of gas barrier films may be one or more, preferably two or more, more preferably three or more, and more preferably four or more. Moreover, although the upper limit of the number of the gas barrier films in the outer packaging material of this indication is not specifically limited, For example, it can be set to eight.

  In the outer packaging material of the present disclosure, at least one of the gas barrier films may be a first gas barrier film in which the gas barrier film is a metal aluminum film, and among them, the number of the first gas barrier films is preferably two or more. More preferably, the number is 3 or more. Moreover, although the upper limit of the number of the 1st gas barrier films in the outer packaging material of this indication is not specifically limited, For example, it can be set to eight.

  When the outer packaging material of the present disclosure has one or more first gas barrier films and one or more second gas barrier films, the above-mentioned heat welding of the first gas barrier film farthest from the heat weldable film is possible. It is preferable to have at least one second gas barrier film on the side opposite to the film. Among them, the gas barrier film of the second gas barrier film disposed on the opposite side of the first gas barrier film farthest from the heat-weldable film from the heat-weldable film is an inorganic compound film or M-O-P. A film having a bond is preferable.

  The thickness of the outer packaging material of the present disclosure is not particularly limited as long as it has the above-described characteristics, and can be, for example, in the range of 30 μm to 200 μm, preferably in the range of 50 μm to 150 μm.

  As a manufacturing method of the outer packaging material of this indication, the method of bonding each film manufactured previously through the adhesive layer mentioned above is mentioned, for example. Further, the outer packaging material of the present disclosure may be manufactured by sequentially extruding and laminating the raw materials of each film that has been heat-melted with a T die or the like.

  The outer packaging material of this indication can be used for a vacuum heat insulating material. In the vacuum heat insulating material, the outer packaging material of the present disclosure can be used by being disposed so as to face each other through the core material such that the heat-weldable film is on the core material side.

II. Vacuum heat insulating material The vacuum heat insulating material of the present disclosure is a vacuum heat insulating material having a core material and an outer packaging material that encloses the core material, and the outer packaging material is the above-mentioned “I. External packaging material for vacuum heat insulating material”. It is what is described in the section.

  FIG. 2 is a schematic cross-sectional view illustrating an example of the vacuum heat insulating material of the present disclosure. The vacuum heat insulating material 20 illustrated in FIG. 2 includes a core material 11 and an outer packaging material 10 that encloses the core material 11, and the outer packaging material 10 is the vacuum heat insulating material outer packaging material described in FIG. 1. The vacuum heat insulating material 20 is a bag body in which two outer packaging materials 10 face each other so that respective heat-weldable films face each other, and end portions 12 are joined by heat welding. The core material 11 is enclosed, and the bag body is decompressed.

According to the present disclosure, the outer packaging material that encloses the core material is the outer packaging material for vacuum heat insulating material described in the above-mentioned section of “I. Outer packaging material for vacuum heat insulating material”. Good thermal insulation performance can be maintained for a period.
Hereinafter, the vacuum heat insulating material of the present disclosure will be described for each configuration.

1. Outer packaging material The outer packaging material in the present disclosure is a member that encloses the core material, and is the same as the outer packaging material for vacuum heat insulating material described in the above-mentioned section of “I. Outer packaging material for vacuum heat insulating material”. Description is omitted.

2. Core Material The core material in the present disclosure is a member that is enclosed by an outer packaging material. The term “encapsulated” refers to sealing inside a bag formed using an outer packaging material.

  The core material preferably has a low thermal conductivity. The core material can be a porous material having a porosity of 50% or more, particularly 90% or more.

  As a material constituting the core material, powder, foam, fiber, or the like can be used. The powder may be either inorganic or organic, and for example, dry silica, wet silica, agglomerated silica powder, conductive powder, calcium carbonate powder, perlite, clay, talc and the like can be used. Among these, a mixture of dry silica and conductive powder is advantageous when used in a temperature range in which an increase in internal pressure occurs because the decrease in heat insulation performance associated with an increase in internal pressure of the vacuum heat insulating material is small. Furthermore, when a substance having a small infrared absorptance such as titanium oxide, aluminum oxide or indium-doped tin oxide is added as a radiation suppressing material to the above-described material, the infrared absorptivity of the core material can be reduced.

  As the foam, urethane foam, styrene foam, phenol foam and the like can be used. Among them, a foam that forms open cells is preferable.

  The fiber body may be an inorganic fiber or an organic fiber, but it is preferable to use an inorganic fiber from the viewpoint of heat insulation performance. Examples of such inorganic fibers include glass fibers such as glass wool and glass fibers, alumina fibers, silica alumina fibers, silica fibers, ceramic fibers, and rock wool. These inorganic fibers are preferable in that they have low thermal conductivity and are easier to handle than powders.

  As the core material, the above-described materials may be used alone, or a composite material in which two or more materials are mixed may be used.

3. Vacuum heat insulating material As for the vacuum heat insulating material of this indication, a core material is enclosed with the inside of an outer packaging material, and the above-mentioned inside is decompressed and it is in a vacuum state. The degree of vacuum inside the vacuum heat insulating material is preferably 5 Pa or less, for example. This is because heat conduction by convection of air remaining inside can be lowered, and excellent heat insulation can be exhibited.

  The heat conductivity of the vacuum heat insulating material is preferably as low as possible. For example, the heat conductivity (initial heat conductivity) is preferably 5 mW / (mK) or less. This is because the vacuum heat insulating material is difficult to conduct heat to the outside, and a high heat insulating effect can be achieved. Among these, the initial thermal conductivity is more preferably 4 mW / (mK) or less, and further preferably 3 mW / (mK) or less.

The thermal conductivity conforms to JIS A1412-2: 1999 (Method for measuring thermal resistance and thermal conductivity of thermal insulation material-Part 2: Heat flow meter method (HFM method)), and uses a thermal conductivity measuring device. It can be a value measured by a heat flow meter method. As the thermal conductivity measuring device, for example, a thermal conductivity measuring device Auto Lambda (product name: HC-074, manufactured by Eihiro Seiki Co., Ltd.) can be used. The measurement is performed under the following conditions so that both main surfaces of the measurement sample (vacuum heat insulating material) are directed in the vertical direction. Before measuring the thermal conductivity, it is preferable to measure in advance using a heat flow meter or the like whether the temperature of the measurement sample is equal to the measurement environment temperature. Under one condition, at least three samples are measured, and the average of the measured values is taken as the thermal conductivity value of the condition.
(Measurement conditions for thermal conductivity)
・ Measurement sample: width 29cm ± 0.5cm, length 30cm ± 0.5cm
・ Time required for steady state of test: 15 minutes or more ・ Type of standard plate: EPS
・ Hot surface temperature: 30 ℃
・ Cold surface temperature: 10 ℃
-Average temperature of measurement sample: 20 ° C

4). Others A general method can be used for the manufacturing method of the vacuum heat insulating material of the present disclosure. For example, two outer packaging materials for vacuum heat insulating material described in the section of “I. Vacuum insulating material outer packaging material” described above are prepared, the respective heat-weldable films are faced to each other, and the outer edges of the three sides are overlapped. The bag body which heat-welds and opens one side is obtained. After putting the core material into the bag body from the opening, the vacuum heat insulating material can be obtained by sucking air from the opening and sealing the opening in a state where the inside of the bag body is decompressed.

  The vacuum heat insulating material of this indication can be used for the article which requires thermal insulation, for example. The article will be described later.

III. Article with vacuum heat insulating material Article with vacuum heat insulating material of the present disclosure is an article with a heat insulating region and an article with a vacuum heat insulating material provided with a vacuum heat insulating material, wherein the vacuum heat insulating material includes a core material and a core material enclosed The outer packaging material is the outer packaging material for vacuum heat insulating material described in the above-mentioned section “I. Outer packaging material for vacuum heat insulating material”.

  According to the present disclosure, the vacuum heat insulating material used for the article is configured by the outer packaging material described in the section “I. Vacuum heat insulating material outer packaging material”, and the vacuum heat insulating material is used for a long time in a high temperature and high humidity environment. Since good heat insulation performance can be exhibited, it is possible to achieve energy saving of an article that becomes a high-temperature and high-humidity environment or an object in which the article is used.

  Since the vacuum heat insulating material and the outer packaging material used in the present disclosure have been described in detail in the above-mentioned sections of “II. Vacuum heat insulating material” and “I. Vacuum heat insulating material outer packaging material”, description thereof is omitted here. To do.

  The article in the present disclosure has a thermally insulating region. Here, the heat insulating region is a region that is thermally insulated by a vacuum heat insulating material, for example, a region that is kept warm or cold, 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. It is. These areas may be spaces or objects. Examples of the above-mentioned articles include, for example, electric devices such as refrigerators, freezers, heat insulators, and coolers, heat insulation containers, cold insulation containers, transport containers, containers, containers such as storage containers, vehicles such as vehicles, airplanes, and ships, houses, warehouses, etc. Building materials such as building materials, wall materials and floor materials.

  Hereinafter, the present disclosure will be described more specifically with reference to examples and comparative examples.

[material]
The members constituting the outer packaging material for vacuum heat insulating materials of Examples and Comparative Examples are shown below and in Table 1. Moreover, the adhesive agent used by the Example and the comparative example is shown below.

(Element)
Gas barrier film A: PET film having a layer having an M-O-P bond on one side (thickness 12 μm, Clarista CF manufactured by Kuraray Co., Ltd.)
Gas barrier film B: PET film with a metal aluminum (Al) film deposited on one side (thickness 12 μm, VM-PET1519 manufactured by Toray Film Processing Co., Ltd.)
Gas barrier film C: PET film with a metal aluminum (Al) film deposited on one side (thickness 12 μm, Toray Film Processing Co., Ltd. VM-PET1510)
Gas barrier film D: ethylene-vinyl alcohol copolymer (EVOH) film (thickness 15 μm, VMXL manufactured by Kuraray Co., Ltd.) with a metal aluminum (Al) film deposited on one side
Gas barrier film E: EVOH film with a metal aluminum (Al) film deposited on one side (thickness 12 μm, TMXL manufactured by Kuraray Co., Ltd.)
Gas barrier film F: A polyethylene terephthalate (PET) film (PET-F, manufactured by Unitika Ltd.) has a silicon oxide (SiO ₂ ) film (thickness 20 nm) on one side, and silica (SiO ₂ ) on the SiO ₂ film. ) A film further having an overcoat layer formed by the following method on the film. A film A that can be thermally welded: an unstretched linear short-chain branched polyethylene film (thickness 50 μm, TUX-HCE manufactured by Mitsui Chemicals, Inc.).
Heat-weldable film B: Polybutylene terephthalate (PBT) film (thickness 25 μm, Unitika P782)
Heat-weldable film C: unstretched polypropylene film (thickness 50 μm, CPP-SC manufactured by Toray Film Processing Co., Ltd.)
Protective film A: Biaxially stretched nylon film (thickness 25 μm, Unitika Emblem ONBC)

(Method for forming overcoat layer in gas barrier film F)
The overcoat layer of the gas barrier film F was formed by the following method. First, liquid A (mixed solution comprising polyvinyl alcohol, isopropyl alcohol and ion-exchanged water) prepared according to the composition shown in Table 1 was mixed with liquid B (tetraethoxysilane (TEOS), isopropyl alcohol) prepared in advance according to the composition shown in Table 1. Then, a hydrolyzate composed of hydrochloric acid and ion-exchanged water) was added and stirred, and a colorless and transparent composition for a barrier coating film was obtained by a sol-gel method. Next, the composition for a barrier coating film prepared by the above-described method is coated on the SiO ₂ film by a gravure coating method, followed by heat treatment at 120 ° C., 140 ° C., and 150 ° C. for 20 seconds each to apply the barrier coating. A film (thickness 200 nm) was formed and aged at 55 ° C. for 1 week. Thereby, a PVA-TEOS sol-gel compound layer containing a metal element (Si), an oxygen element (O), and a hydrophilic group-containing resin (PVA) was formed as an overcoat layer on the SiO ₂ film.

(adhesive)
Adhesive A: Main component mainly composed of polyester polyol (product name: RU-77T manufactured by Rock Paint), curing agent containing aliphatic isocyanate (product name: H-7 manufactured by Rock Paint), and ethyl acetate A two-component curable adhesive / adhesive B in which the solvent is mixed at a weight ratio of main component: curing agent: solvent = 10: 1: 14: a main component (DIC) containing polyester polyol and epoxy resin as main components (DIC) A product name LX-605 manufactured by Graphics, Inc., a curing agent containing aromatic isocyanate (product name KW-40 manufactured by DIC Graphics), and a solvent of ethyl acetate are mixed in a weight ratio of main agent: curing agent: ethyl acetate. = Two-component curable adhesive mixed so as to be 10: 1: 8

[Example 1]
(Preparation of outer packaging material for vacuum insulation)
An outer packaging material having a gas barrier film A as a first member, a gas barrier film B as a second member, a gas barrier film D as a third member, and a thermally weldable film A as a fourth member was obtained in this order. The gas barrier film A is arranged so that the film having the M-O-P bond is directed to the second member side than the PET film, and the gas Al film is directed to the third member side of the gas barrier film B than the PET film. The gas barrier film D was arranged so that the metal Al vapor deposition film faced the second member side than the EVOH film. Between each member, adhesive A is applied to the surface of one member so that the applied amount is 3.5 g / m ² to form an adhesive layer, and the other member is placed on the adhesive layer and added. Press to bond.

(Preparation of vacuum insulation)
Two outer packaging materials (dimensions: 360 mm × 450 mm) obtained in Example 1 were prepared, two sheets were stacked so that the heat-weldable films face each other, and the three sides of the quadrilateral were heat-sealed, and only one side. A bag with an opening was created. The glass wool of 290 mm × 300 mm × 30 mm was used as the core material, and after drying treatment, 5 g of calcium oxide was housed in the bag body as the core material and the desiccant, and the inside of the bag body was evacuated. Then, the opening part of the bag body was sealed by heat sealing to obtain a vacuum heat insulating material. The ultimate pressure was 0.05 Pa.

[Example 2]
An outer packaging material having a gas barrier film A as the first member, a gas barrier film A as the second member, a gas barrier film E as the third member, and a thermally weldable film A as the fourth member was obtained. The gas barrier film A of the first member is arranged so that the film having the M-O-P bond is directed to the second member side than the PET film, and the gas barrier film A of the second member is M-O than the PET film. The film having —P bond was disposed so as to face the third member side, and the gas barrier film E was disposed such that the metal Al vapor deposition film faced the second member side rather than the EVOH film. Each member was bonded using an adhesive A through an adhesive layer in the same manner as in Example 1. Moreover, the vacuum heat insulating material was obtained by the same method as Example 1.

[Example 3]
An outer packaging material having a gas barrier film F as a first member, a gas barrier film C as a second member, a gas barrier film D as a third member, and a thermally weldable film B as a fourth member was obtained in this order. The gas barrier film F is arranged so that the SiO ₂ vapor deposition film faces the second member side than the PET film, and the gas barrier film C is arranged so that the metal Al vapor deposition film faces the third member side than the PET film, The gas barrier film D was disposed so that the metal Al vapor deposition film faced the second member side as compared with the EVOH film. Each member was bonded using an adhesive A through an adhesive layer in the same manner as in Example 1. Moreover, the vacuum heat insulating material was obtained by the same method as Example 1.

[Example 4]
An outer packaging material having a gas barrier film B as a first member, a gas barrier film B as a second member, a gas barrier film E as a third member, and a thermally weldable film C as a fourth member was obtained in this order. The gas barrier film B of the first member is arranged so that the metal Al vapor deposition film faces the second member side than the PET film, and the gas barrier film B of the second member has the metal Al vapor deposition film third member than the PET film. The gas barrier film E was disposed so that the metal Al vapor deposition film was directed to the second member side rather than the EVOH film. Each member was bonded using an adhesive A through an adhesive layer in the same manner as in Example 1. Moreover, the vacuum heat insulating material was obtained by the same method as Example 1.

[Comparative Example 1]
An outer packaging material having a protective film A as the first member, a gas barrier film C as the second member, a gas barrier film D as the third member, and a thermally weldable film A as the fourth member was obtained. The gas barrier film C was arranged so that the metal Al vapor deposition film faces the third member side than the PET film, and the gas barrier film D is arranged so that the metal Al vapor deposition film faces the second member side than the EVOH film. Each member was bonded using an adhesive A through an adhesive layer in the same manner as in Example 1. Moreover, the vacuum heat insulating material was obtained by the same method as Example 1.

[Comparative Example 2]
An outer packaging material was obtained in the same manner as in Comparative Example 1 except that the adhesive B was used in place of the adhesive A. Moreover, the vacuum heat insulating material was obtained by the same method as Example 1.

[Comparative Example 3]
An outer packaging material was obtained in the same manner as in Example 4 except that the adhesive B was used in place of the adhesive A. Moreover, the vacuum heat insulating material was obtained by the same method as Example 1.

[Evaluation]
Table 3 shows the layer structures of Examples 1 to 4 and Comparative Examples 1 to 3. In Table 3, “//” indicates an interface through an adhesive layer.

1. Thickness expansion coefficient of outermost metallic aluminum film after holding at high temperature and high humidity About each outer packaging material obtained in Examples 1 to 4 and Comparative Examples 1 to 3, the method described in the section “I. Outer packaging material for vacuum heat insulating material” And the thickness T ₁ of the outermost metal aluminum film before being held for 500 hours in an atmosphere at a temperature of 70 ° C. and a humidity of 90% RH, and the maximum after holding for 500 hours in an atmosphere of a temperature of 70 ° C. and a humidity of 90% RH. The thickness T ₂ of the outer metal aluminum film was measured, and the thickness expansion rate (%) of the outermost metal aluminum film after holding at high temperature and high humidity was calculated from the obtained T ₁ and T ₂ . The results are shown in Table 4.

2. Water vapor permeability For each outer packaging material obtained in Examples 1 to 4 and Comparative Examples 1 to 3, the initial water vapor permeability (A), according to the method and conditions described in the section of “I. The water vapor permeability (B) after holding for 500 hours in an atmosphere at a temperature of 70 ° C. and a humidity of 90% RH was measured. Moreover, the deterioration amount (BA) of the water-vapor permeability before and behind holding for 500 hours in the atmosphere of temperature 70 degreeC and humidity 90% RH was computed. The results are shown in Table 5.

3. Oxygen permeability For each of the outer packaging materials obtained in Examples 1 to 4 and Comparative Examples 1 to 3, the initial oxygen permeability (A) according to the method and conditions described in the section “I. Outer packaging material for vacuum heat insulating material”, The oxygen permeability (B) after holding for 500 hours in an atmosphere of temperature 70 ° C. and humidity 90% RH was measured. Moreover, the deterioration amount (BA) of oxygen permeability before and after holding for 500 hours in an atmosphere of temperature 70 ° C. and humidity 90% RH was calculated. The results are shown in Table 5.

4). Moisture content About each outer packaging material obtained in Examples 1-4 and Comparative Examples 1-3, the moisture content was measured according to the method and conditions demonstrated in the term of "I. outer packaging material for vacuum heat insulating materials". The results are shown in Table 5.

5. Ash content About each outer packaging material obtained in Examples 1 to 4 and Comparative Examples 1 to 3, ash content was measured according to the method and conditions described in the section “I. External packaging material for vacuum heat insulating material”. The results are shown in Table 5.

6). Thermal conductivity For each vacuum heat insulating material obtained in Examples 1 to 4 and Comparative Examples 1 to 3, the initial (temperature 70 ° C., humidity 90%) according to the method and conditions described in the section “II. Thermal conductivity (A) before holding in an RH atmosphere (A), temperature 70 ° C., humidity 90% RH after holding for 150 hours in an atmosphere (B), temperature 70 ° C., humidity 90% RH The thermal conductivity (C) after holding for 500 hours in the atmosphere was measured. Also, the ratio (B / A) of the thermal conductivity after holding for 150 hours in an atmosphere with a temperature of 70 ° C. and a humidity of 90% RH with respect to the initial thermal conductivity, an atmosphere with a temperature of 70 ° C. and a humidity of 90% RH with respect to the initial thermal conductivity. The ratio (C / A) of thermal conductivity after holding for 500 hours was calculated. The results are shown in Table 6.

[Discussion]
Since the expansion rate of the outermost metal aluminum film was less than or equal to a predetermined value, the outer packaging materials of Examples 1 to 4 had a temperature of 70 ° C. and a humidity of 90% RH as compared with the outer packaging materials of Comparative Examples 1 to 3. It was confirmed that the deterioration amount of water vapor permeability after holding for 500 hours in the atmosphere was small. It was suggested that the deterioration of the outermost metallic aluminum film due to wet heat greatly contributes to the reduction of the water vapor permeability of the entire outer packaging material.

  Moreover, the vacuum heat insulating material using the outer packaging material of Examples 1 to 4 has a temperature of 70 ° C. and humidity relative to the initial thermal conductivity as compared with the vacuum heat insulating material using the outer packaging material of Comparative Examples 1 to 3. The ratio of thermal conductivity after holding for 150 hours in an atmosphere of 90% RH, and the ratio of thermal conductivity after holding for 500 hours in an atmosphere of temperature 70 ° C. and humidity 90% RH with respect to the initial thermal conductivity are small. It was.

  From these results, the vacuum heat insulating material using the outer packaging material in which the expansion coefficient of the outermost metallic aluminum film is a predetermined value or less can maintain the heat insulating performance for a predetermined period in a high temperature and high humidity environment. confirmed.

  Moreover, when the expansion coefficient of the outermost metallic aluminum film is not more than a predetermined value and the ash content is not less than a predetermined value (1.0%), the initial gas barrier performance is good, and after storage in a high temperature and high humidity environment The amount of deterioration of gas barrier performance was also small. From this result, the outer packaging material has an expansion coefficient of the outermost metal aluminum film that is not more than a predetermined value and further has an ash content within a predetermined range. It was suggested that good insulation performance was maintained as a material.

DESCRIPTION OF SYMBOLS 1 ... Film which can be thermally welded 2A, 2B, 2C ... Gas barrier film 3A, 3B, 3C ... Resin base material 4A, 4B, 4C ... Gas barrier film 10 ... Outer packaging material for vacuum heat insulating material 11 ... Core material 20 ... Vacuum heat insulating material

Claims (1)

A heat-weldable film, and one or more gas barrier films having a resin base material and a gas barrier film disposed on one surface side of the resin base material,
At least one of the gas barrier films is a vacuum insulation outer packaging material that is a metal aluminum film,
An outer packaging material for a vacuum heat insulating material, wherein a thickness expansion coefficient of the metal aluminum film farthest from the heat-weldable film after holding in an atmosphere of a temperature of 70 ° C. and a humidity of 90% RH for 500 hours is 200% or less.

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