JP7106941B2 - Outer packaging for vacuum insulation, vacuum insulation, and articles with vacuum insulation - Google Patents

Description

TECHNICAL FIELD The present disclosure relates to a vacuum insulation outer wrapping material used to form a vacuum insulation material.

In recent years, vacuum heat insulating materials have been used for the purpose of saving energy in articles. The vacuum insulation material has a core material arranged in a closed space of a bag body having a sealed end formed by bonding the peripheral edge of the outer wrapping material, and the inside of the closed space is kept in a vacuum state with a pressure lower than atmospheric pressure. Since the heat convection inside is suppressed, good heat insulating performance can be exhibited. In addition, the outer wrapping material used for the vacuum heat insulating material will be referred to as the outer wrapping material for the vacuum heat insulating material or simply as the outer wrapping material.

In order to maintain the vacuum state inside the vacuum insulation material for a long period of time, the outer packaging material for the vacuum insulation material has a gas barrier function to suppress the permeation of gases such as oxygen and water vapor, and heat-welds the peripheral edges of a pair of facing outer packaging materials. Physical properties such as thermal adhesiveness are required for forming a bag body having a sealed end formed by joining with a pliers and enclosing and sealing the core material. In order to satisfy these physical properties, a laminate containing a gas barrier layer and a heat-sealable film as constituent members is generally adopted as an outer packaging material for a vacuum heat insulating material (Patent Documents 1 to 5).

Japanese Patent Application Laid-Open No. 2003-262296 JP 2013-103343 A JP-A-2006-70923 JP 2014-62562 A JP 2004-036749 A

As disclosed in Patent Documents 1 to 5, for example, a polyethylene film is preferably used as the heat-sealable film. However, polyethylene films may have difficulty exhibiting good water vapor barrier performance in high humidity environments. In addition, it is sometimes difficult to exhibit good water vapor barrier performance in a high-humidity environment for outer packaging materials for vacuum insulation materials that use polyethylene films that can be heat-sealed, due to the water vapor barrier performance of polyethylene films. be. Furthermore, when the heat-sealable film is a polyethylene film, even if the outer packaging material for a vacuum insulation material alone can exhibit good water vapor barrier performance, the vacuum insulation material using it has poor insulation performance. Long-term maintenance may be difficult.

The present disclosure has been made in view of the above circumstances, and provides a vacuum insulation material that has good water vapor barrier performance as a single unit in a high-humidity environment and that can maintain the heat insulation performance for a long period of time in a high-humidity environment. It is a primary object to provide formable vacuum insulation envelopes, vacuum insulation, and articles with vacuum insulation.

The present disclosure provides an outer packaging material for a vacuum insulation material, which has a heat-sealable film and a gas barrier layer, and the heat-sealable film is a polyethylene film having a melting rate of 3.0% or less at 40°C. offer.

Further, the present disclosure has a heat-sealable film and a gas barrier layer, and the heat-sealable film is a polyethylene film having a melting rate of 10.0% or less at 70 ° C. An outer package for a vacuum insulation material provide materials.

The present disclosure is a vacuum heat insulating material having a core material and an outer wrapping material enclosing the core material, the outer wrapping material having a heat-sealable film and a gas barrier layer, the heat-sealable film comprising 40 A vacuum heat insulating material is provided which is a polyethylene film having a melting rate at °C of 3.0% or less.

Further, the present disclosure is a vacuum heat insulating material having a core material and an outer wrapping material enclosing the core material, wherein the outer wrapping material includes a heat-sealable film and a gas barrier layer, and the heat-sealable film is and a polyethylene film having a melting rate of 10.0% or less at 70°C.

The present disclosure is an article having a heat insulating region and an article with a vacuum insulation material comprising a vacuum insulation material, wherein the vacuum insulation material has a core material and an outer wrapping material that encloses the core material, and the outer wrapping material is and a heat-sealable film and a gas barrier layer, wherein the heat-sealable film is a polyethylene film having a melting rate of 3.0% or less at 40°C.

The present disclosure also provides an article having a heat insulating region and an article with a vacuum insulation material including a vacuum insulation material, wherein the vacuum insulation material has a core material and an outer wrapping material that encloses the core material, and the outer wrapping The material has a heat-weldable film and a gas barrier layer, and the heat-weldable film is a polyethylene film having a melting rate of 10.0% or less at 70° C. to provide an article with a vacuum insulation material. .

According to the outer packaging material for a vacuum insulation material of the present disclosure, it is possible to form a vacuum insulation material that has good water vapor barrier performance by itself in a high-humidity environment and that can maintain the insulation performance for a long period of time in a high-humidity environment. It has the effect of being

1 is a schematic cross-sectional view showing an example of an outer wrapping material for a vacuum heat insulating material of the present disclosure; FIG. 1A and 1B are a schematic perspective view and a cross-sectional view showing an example of a vacuum heat insulating material of the present disclosure; FIG.

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings and the like. However, the present disclosure can be embodied in many different modes and should not be construed as limited to the description of the embodiments exemplified below. In addition, in order to make the description clearer, the drawings may schematically represent the width, thickness, shape, etc. of each part compared to the embodiment, but this is only an example and limits the interpretation of the present disclosure. not something to do. In addition, in this specification and each figure, the same reference numerals may be given to the same elements as those described above with respect to the existing figures, and detailed description thereof may be omitted as appropriate. Also, for convenience of explanation, the terms "upper" and "lower" may be used, but the up-down direction may be reversed.

Also, in this specification, there is no particular limitation when a configuration such as a member or a region is “above (or below)” another configuration such as another member or another region. So far, this includes not only when directly above (or directly below) other structures, but also when above (or below) other structures, i.e. above (or below) other structures and between other structures. Including cases where the constituent elements of are included.

Hereinafter, the outer packaging material for a vacuum heat insulating material, the vacuum heat insulating material, and the article with the vacuum heat insulating material of the present disclosure will be described respectively. In the present disclosure, the terms "sheet" and "film" may be used synonymously.

I. Vacuum Insulating Material Wrapping Material The vacuum insulating material wrapping material of the present disclosure has a heat-sealable film and a gas barrier layer. The outer packaging material for a vacuum insulation material of the present disclosure is a first embodiment in which the heat-sealable film is a polyethylene film having a melting rate at 40 ° C. of 3.0% or less, and the heat-sealable film is , and the second embodiment, which is a polyethylene film having a melting rate of 10.0% or less at 70°C.

FIG. 1 is a schematic cross-sectional view showing an example of the outer wrapping material for a vacuum heat insulating material of the present disclosure. An outer packaging material 10 for a vacuum heat insulating material has a heat-sealable film 1 and a gas barrier layer 2 disposed on one surface of the heat-sealable film 1 . The gas barrier layer 2 in FIG. 1 is a gas barrier film having a base material 11 and a gas barrier film 12 disposed on one surface of the base material 11 (the surface on the heat-sealable film 1 side). In the first embodiment of the outer wrapping material for vacuum insulation material of the present disclosure, the heat-sealable film 1 is a polyethylene film having a melting rate at 40° C. of 3.0% or less. In a second embodiment of the outer packaging material for a vacuum heat insulating material of the present disclosure, the heat-sealable film 1 is a polyethylene film having a melting rate of 10.0% or less at 70°C.

Here, in the present disclosure, the “melting rate” of the polyethylene film is an index for understanding the crystalline state of the polyethylene film, and the “melting rate at temperature X” is the total crystal phase of the polyethylene film. , refers to the ratio of the crystalline phase to the amorphous phase at a temperature X. For example, a polyethylene film having a melting rate of 20% at temperature X refers to a polyethylene film in which 20% of the total crystalline phase of the polyethylene film is melted at temperature X to become an amorphous phase.

The "melting rate at temperature X" can be obtained from the ratio (%) of the heat of crystal fusion in the temperature range below temperature X to the total heat of crystal fusion of the polyethylene film, and can be calculated from the following formula (1). .
Melting rate (%) at temperature X={(crystal melting heat quantity in temperature range below temperature X)/(total crystal melting heat quantity)}×100 Equation (1)

Note that the temperature X is 40° C. in the first embodiment of the outer packaging material for a vacuum insulation panel of the present disclosure, and 70° C. in the second embodiment. The same applies to the following description.

The total crystal melting heat of the polyethylene film is determined by differential scanning calorimetry (hereinafter sometimes referred to as DSC) in accordance with JIS K7122 (1999), and the temperature is -50°C at a heating rate of 10°C/min in a nitrogen atmosphere. A first temperature raising process in which the temperature is raised from to 200 ° C., a temperature lowering process in which the temperature is lowered to -50 ° C. at a cooling rate of 10 ° C./min after holding at 200 ° C. for 5 minutes, and after holding at -50 ° C. for 10 minutes, again A second heating process in which the temperature is raised to 200 ° C. at a heating rate of 10 ° C./min, and a thermogram (vertical axis: heat amount [J / g], horizontal axis: temperature [° C.]). It is calculated from the melting peak area during the temperature process. DSC measurement is carried out by placing a 5 mg sample taken from a polyethylene film as a heat-sealable film of the outer packaging material for a vacuum insulation material in an aluminum cell. The differential scanning calorimeter used for the measurement can be selected from commercially available ones, such as "DSC204" manufactured by NETZSCH. The melting peak area is the area surrounded by the melting curve and the baseline connecting the endothermic start temperature and the endothermic end temperature in the thermogram (chart diagram) of the second heating process. The baseline is the data point of the thermogram endothermic amount at the low temperature side temperature (0 ° C.) and the thermogram endothermic amount at the high temperature side temperature (150 ° C.) on the thermogram (chart diagram) of the second temperature rising process. A straight line connecting the data points. On the other hand, the heat of crystal fusion in the temperature range below the temperature X of the polyethylene film is calculated from the area of the temperature range below the temperature X among the melting peak areas when calculating the total heat of crystal fusion. That is, the "melting rate at temperature X" is, in other words, a value calculated from the following formula (2).
Melting rate (%) at temperature X={(Area of temperature range below temperature X in melting peak area)/(Melting peak area)}×100 Equation (2)

Hereinafter, the outer wrapping material for a vacuum heat insulating material of the present disclosure will be described for each embodiment.

A. First Embodiment The first embodiment of the outer packaging material for a vacuum insulation material of the present disclosure (hereinafter sometimes referred to as the outer packaging material for a vacuum insulation material of this aspect in this section) is a heat-sealable film and a gas barrier layer and the heat-sealable film is a polyethylene film having a melting rate of 3.0% or less at 40°C.

It is speculated that a part of the crystalline phase of the polyethylene film melts and changes to an amorphous phase even in a temperature environment lower than the melting point. Gases such as water vapor permeate the amorphous phase, so the greater the proportion of the amorphous phase in the film, the more easily the polyethylene film permeates water vapor. be inferred. This tendency is considered to become more pronounced in a high-humidity environment in which a large amount of water vapor exists. If such a polyethylene film with low water vapor barrier performance is used as a film that can be heat-sealed in the outer packaging material for a vacuum heat insulating material, it is thought that the water vapor barrier performance of the entire outer wrapping material for a vacuum heat insulating material will also decline.

In addition, when the heat-sealable film of the outer packaging material for the vacuum insulation material is a polyethylene film, even if the outer packaging material for the vacuum insulation material alone can exhibit good water vapor barrier performance, the vacuum It may be difficult for the heat insulating material to maintain its heat insulating performance for a long period of time in a high humidity environment. Although the reason for this is not clear, the following is presumed. That is, when the heat-sealable film is a polyethylene film, permeation of water vapor from the main surface of the vacuum heat insulating material can be suppressed by a gas barrier layer arranged outside the polyethylene film. However, since the polyethylene film is exposed at the end face of the seal end, the permeation of water vapor from the end face cannot be sufficiently suppressed, and as a result, the internal vacuum state of the vacuum heat insulating material is likely to be impaired. be done.

On the other hand, according to the outer packaging material for a vacuum insulation material of this aspect, the film that can be heat-sealed is a polyethylene film having a melting rate at 40°C of a predetermined value or less, so that the temperature around 40°C and the high temperature Good water vapor barrier performance can be exhibited in a humid environment. The reason for this is presumed to be as follows. That is, since the polyethylene film has a melting rate at 40°C of a predetermined value or less, the rate of change from a crystalline phase to an amorphous phase due to melting in a temperature environment around 40°C is small, and crystals occupying the film It is speculated that the phase fraction is large and can have a dense internal state. Therefore, it is considered that the polyethylene film becomes less permeable to water vapor from the surface and side surfaces in a high-humidity environment at a temperature of around 40°C. By using such a polyethylene film as a film that can be heat-sealed, the vacuum insulation outer packaging material of this embodiment can exhibit high water vapor barrier performance in an environment with a temperature of around 40° C. and high humidity. In addition, since permeation of water vapor from the end face of the seal end can be suppressed, a vacuum heat insulating material capable of maintaining heat insulating performance for a long period of time in the same environment can be formed.

The details of the outer packaging material for a vacuum heat insulating material according to this aspect will be described below.

1. Heat-Sealable Film The heat-sealable film in the outer packaging material for vacuum insulation according to this aspect is a member positioned at one outermost side in the thickness direction of the outer packaging material for vacuum insulation material and serving as one of the outermost surfaces. The heat-sealable film is in contact with the core material when the vacuum heat insulating material is produced using the outer packaging material for the vacuum heat insulating material. It is a member that joins the peripheral edges of the outer packaging material for a vacuum heat insulating material by thermal welding.

In the outer packaging material for a vacuum heat insulating material of this aspect, the heat-sealable film is a polyethylene film having a melting rate at 40° C. of a predetermined value or less. Specifically, the heat-weldable film may be a polyethylene film having a melting rate of 3.0% or less at 40°C, and more particularly polyethylene having a melting rate of 2.5% or less at 40°C. A film is preferred, a polyethylene film having a melting rate at 40° C. of 2.3% or less is more preferred, and a polyethylene film having a melting rate at 40° C. of 2.0% or less is particularly preferred. A polyethylene film having a melting rate at 40°C of a predetermined value or less can have a dense internal state with a large proportion of a crystalline phase in a temperature environment around 40°C, thereby preventing permeation of water vapor from the surface and sides. This is because it is presumed that the

In addition, the polyethylene film having a melting rate at 40°C of a predetermined value or less preferably has a melting rate at 70°C of 10.0% or less, more preferably 9.0% or less, particularly 8 0% or less is more preferable. A polyethylene film having a melting rate at 40°C of not more than a predetermined value and a melting rate at 70°C of not more than a predetermined value is not only in a temperature environment around 40°C but also in a temperature environment around 70°C. This is because it is possible to have a dense internal state with a large ratio of .

A polyethylene film having a melting rate at 40° C. of a predetermined value or less preferably has a molecular weight distribution of 4.0 or more, more preferably 4.5 or more, and particularly preferably 5.0 or more. . The molecular weight distribution is preferably 7.0 or less, more preferably 6.5 or less, and particularly preferably 6.0 or less. The molecular weight distribution of a polyethylene film is a value calculated from the weight average molecular weight (Mw) and number average molecular weight (Mn) of the polyethylene film, and the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn) (Mw/Mn ). The weight-average molecular weight (Mw) and number-average molecular weight (Mn) are polystyrene-equivalent molecular weights measured by gel permeation chromatography (GPC), and samples taken from polyethylene films used as heat-sealable films in outer packaging materials for vacuum insulation materials. was dissolved in o-dichlorobenzene at 145° C. under the conditions of standing for 1 hour and stirring for 1 hour, and filtered under pressure through a membrane filter with a filter pore size of 0.5 μm and a membrane filter with a filter pore size of 1.0 μm. shall be the value measured under the conditions of
(conditions)
・Apparatus: Senshu Kagaku SSC-7120 HT-GPC System
・ Sample volume: around 3 mg of polyethylene film sample for 3 mL of solvent ・ Injection volume: 300 μL
・Guard column: HT-G
・Column: 2 HT-806M ・Column temperature: 145°C
- Mobile phase: o-dichlorobenzene (containing 0.025 wt% BHT)
・Flow rate: 1.0 mL/min
・Detector: Differential refractometer
・Molecular weight calibration: polystyrene conversion

The total thickness of the heat-sealable film in this embodiment may be any size that allows obtaining a desired adhesive strength when joined by heat-sealing. It can be within the following range, more preferably within the range of 30 μm or more and 100 μm or less.

2. Gas Barrier Layer The gas barrier layer in the outer packaging material for the vacuum heat insulating material of this embodiment is arranged on one side of the heat-sealable film. The gas barrier layer is not particularly limited as long as it can exhibit gas barrier performance against gases such as oxygen and water vapor. Such a gas barrier layer may be, for example, a metal foil or a gas barrier film. Here, the gas barrier film in the present disclosure refers to a composite film having a resin substrate and a gas barrier film disposed on at least one surface of the resin substrate.

Examples of metal foils include aluminum, nickel, stainless steel, iron, copper, and titanium.

A gas barrier film can exhibit gas barrier performance mainly by the gas barrier film. The gas barrier film is thinner than the metal foil described above. Gas barrier films of gas barrier films include, for example, metal thin films formed of metals or alloys such as aluminum, nickel, stainless steel, iron, copper, and titanium; silicon (silica), aluminum, stainless steel, titanium, nickel, iron, copper, Inorganic compound films made of compounds such as magnesium, calcium, potassium, tin, sodium, boron, lead, zinc, zirconium, and yttrium can be used. The gas barrier film is usually formed so as to be in direct contact with at least one surface of the resin substrate. The gas barrier film may be a coating film by coating or the like, or may be a vapor deposition film. The resin base material of the gas barrier film is not particularly limited as long as it can support the gas barrier film, and examples thereof include known resin films such as nylon, polyethylene terephthalate, ethylene-vinyl alcohol copolymer and polypropylene.

The outer packaging material for a vacuum heat insulating material of this aspect has at least one gas barrier layer, but may have two or more. Among them, it is preferable to have three gas barrier layers. Moreover, the plurality of gas barrier layers included in the outer packaging material for a vacuum heat insulating material may be the same, or may differ in type, layer structure, material, and the like.

3. Arbitrary Configuration The outer packaging material for a vacuum heat insulating material of this embodiment has a heat-sealable film on one of the outermost sides in the thickness direction, and may have a protective film on the other outermost side. By having the protective film, it can serve as the other outermost surface in the thickness direction of the outer packaging material for a vacuum heat insulating material, and can protect constituent members other than the protective film from damage and deterioration. As the protective film, a general-purpose resin film having a higher melting point than a heat-sealable film can be used, and examples thereof include nylon film, polyethylene terephthalate film, polybutylene terephthalate film, and polypropylene film. The thickness of the protective film is not particularly limited and can be set as appropriate.

The outer wrapping material for a vacuum heat insulating material of this aspect may have an adhesive layer. The adhesive layer can be located, for example, between the heat-sealable film and the gas barrier layer, between two gas barrier layers, between the gas barrier layer and the protective film, and the like. As a material for the adhesive layer, conventionally known pressure-sensitive adhesives, thermoplastic adhesives, curable adhesives, and the like can be used.

4. Others The outer packaging material for a vacuum insulation material of this aspect only needs to have a heat-sealable film and at least one gas barrier layer, and the layer structure may be appropriately designed according to the gas barrier performance of the outer packaging material for a vacuum insulation material. can be done. For example, it is preferable that the outer wrapping material for a vacuum heat insulating material has a heat-sealable film and three gas barrier layers. Specifically, such an outer packaging material for a vacuum heat insulating material preferably has a configuration in which a heat-sealable film, a first gas barrier layer, a second gas barrier layer, and a third gas barrier layer are provided in this order. Among them, the first gas barrier layer, the second gas barrier layer, and the third gas barrier layer are preferably gas barrier films having a gas barrier film on at least one of a resin base material and a resin base material, and particularly the first gas barrier layer. The layer, the second gas barrier layer, and the third gas barrier layer are preferably gas barrier films having a metal aluminum film on at least one surface of a polyethylene terephthalate resin substrate.

Moreover, it is preferable that the outer packaging material for a vacuum heat insulating material of this aspect has a heat-sealable film, two gas barrier layers, and one protective film. Specifically, such an outer packaging material for a vacuum heat insulating material may have a configuration in which a heat-sealable film, a first gas barrier layer, a second gas barrier layer, and a protective film are provided in this order.

The lower the water vapor permeability of the outer packaging material for a vacuum heat insulating material of this aspect, the better, for example, it is preferably 0.1 g/(m ² ·day) or less, and especially 0.05 g/(m ² ·day) or less. , particularly preferably 0.01 g/(m ² ·day) or less. The value of the water vapor permeability can be the initial water vapor permeability of the outer packaging material for a vacuum heat insulating material of this embodiment.

The water vapor transmission rate of the outer packaging material for vacuum insulation material is measured using a water vapor transmission rate measuring device in accordance with ISO 15106-5:2015 (differential pressure method) under the conditions of a temperature of 40 ° C. and a relative humidity difference of 90% RH. value. First, the outermost surface opposite to the heat-sealable film among the outermost surfaces facing each other in the thickness direction (laminating direction) of a sample of the outer packaging material for the vacuum insulation material cut to a desired size is the high humidity side. (water vapor supply side), and mounted between the upper chamber and the lower chamber of the above apparatus, with a permeation area of about 50 cm ² (permeation area: a circle with a diameter of 8 cm), a temperature of 40 ° C., and a relative humidity difference of 90%. Measurement is performed under RH conditions. For example, "DELTAPERM" manufactured by Technolox, UK can be used as the water vapor transmission rate measuring device. The water vapor transmission rate is measured for at least three samples for each outer packaging material for a vacuum insulation panel, and the average of the measured values is taken as the water vapor transmission rate under that condition.

^In addition, the outer packaging material for a vacuum heat insulating material of this aspect preferably has a ^lower oxygen permeability. *day*atm) or less. The value of the oxygen permeability can be taken as the initial oxygen permeability of the outer packaging material for a vacuum insulation panel of this aspect.

JIS K7126-2: 2006 (Plastics - Film and sheet - Gas permeability test method - Part 2: Isobaric method, Annex A: Oxygen gas permeability by electrolytic sensor method Test method)), using an oxygen gas permeability measuring device, the value measured under the conditions of a temperature of 23 ° C. and a humidity of 60% RH. In the above measurement, the carrier gas was supplied at a flow rate of 10 cc/min for 60 minutes or more and purged, then the test gas (at least 99.5% dry oxygen) was flowed, and the time from the start of flow until reaching equilibrium was 12 hours. , the permeation area is adjusted to about 50 cm ² (permeation area: circular with a diameter of 8 cm), the carrier gas and test gas conditions are adjusted to a temperature of 23° C. and a humidity of 60% RH. As the oxygen gas permeability measuring device, for example, "OXTRAN" manufactured by MOCON, USA can be used. The oxygen permeability is measured for at least three samples for each vacuum insulation outer packaging material, and the average of the measured values is taken as the value of the oxygen permeability under that condition.

The thickness of the outer packaging material for a vacuum heat insulating material of this aspect is not particularly limited, and can be, for example, 30 μm or more, preferably 50 μm or more, and can be 200 μm or less, preferably 150 μm or less.

5. Manufacturing Method The method for manufacturing the outer packaging material for a vacuum insulation panel of this embodiment is not particularly limited, and a known method can be used. For example, a dry lamination method in which a heat-weldable film and a gas barrier layer are formed in advance and laminated via an adhesive layer, or a heat-weldable film on one side of the gas barrier layer directly or via an adhesive layer. and a method of extruding.

6. Application The outer wrapping material for a vacuum heat insulating material according to this aspect can be used as an outer wrapping material for covering a core material in a vacuum heat insulating material. The outer wrapping material for a vacuum heat insulating material is used by arranging the vacuum heat insulating material so that the heat-weldable film faces the core material via the core material, and the peripheral edge is joined by heat welding.

B. Second embodiment The second embodiment of the outer packaging material for a vacuum insulation material of the present disclosure (hereinafter sometimes referred to as the outer packaging material for a vacuum insulation material of this aspect in this section) is a heat-sealable film and a gas barrier layer and the heat-sealable film is a polyethylene film having a melting rate of 10.0% or less at 70°C.

According to the outer packaging material for a vacuum heat insulating material of this aspect, the heat-sealable film is a polyethylene film having a melting rate at 70°C of a predetermined value or less, so that it can be used in a high humidity environment at a temperature around 70°C. Good water vapor barrier performance can be exhibited. That is, for the same reason as explained in the section "A. First Embodiment" above, the polyethylene film has a melting rate at 70°C of not more than a predetermined value, so that the temperature around 70°C and high humidity environment It is presumed that the rate of change from the crystalline phase to the amorphous phase by melting is small in the film, and the rate of the crystalline phase occupying the inside of the film is large, so that the film can have a dense internal state. Therefore, it is considered that the polyethylene film is difficult to permeate water vapor even in an environment with a temperature of about 70° C. and high humidity. By using such a polyethylene film as a film that can be heat-sealed, the vacuum insulation outer packaging material of this embodiment can exhibit high water vapor barrier performance in a high-humidity environment at a temperature of around 70°C. In addition, since permeation of water vapor from the end face of the seal end can be suppressed, a vacuum heat insulating material capable of maintaining heat insulating performance for a long period of time in the same environment can be formed.

The details of the outer packaging material for a vacuum heat insulating material according to this aspect will be described below.

1. Heat-Sealable Film The heat-sealable film in the outer packaging material for vacuum insulation according to this aspect is a member positioned at one outermost side in the thickness direction of the outer packaging material for vacuum insulation material and serving as one of the outermost surfaces. The heat-sealable film is in contact with the core material when the vacuum heat insulating material is produced using the outer packaging material for the vacuum heat insulating material. It is a member that joins the peripheral edges of the outer packaging material for a vacuum heat insulating material by thermal welding.

In the outer packaging material for a vacuum heat insulating material of this aspect, the heat-weldable film is a polyethylene film having a melting rate at 70° C. of a predetermined value or less. Specifically, the film that can be heat-sealed may be a polyethylene film having a melting rate of 10.0% or less at 70°C, and more particularly polyethylene having a melting rate of 9.0% or less at 70°C. A film is preferred, and a polyethylene film having a melting rate at 70° C. of 8.0% or less is particularly preferred. A polyethylene film having a melting rate at 70°C of a predetermined value or less can have a dense internal state with a large proportion of a crystalline phase in a temperature environment around 70°C. This is because it is presumed that the

Further, the polyethylene film having a melting rate at 70° C. of a predetermined value or less preferably has a melting rate at 40° C. of 3.0% or less, more preferably 2.5% or less. It is more preferably 3% or less, and particularly preferably 2.0% or less. A polyethylene film having a melting rate at 70°C of not more than a predetermined value and a melting rate at 40°C of not more than a predetermined value is not only in a temperature environment around 70°C but also in a temperature environment around 40°C. This is because it is possible to have a dense internal state with a large ratio of .

A polyethylene film having a melting rate at 70° C. of a predetermined value or less has a molecular weight distribution within the range of the molecular weight distribution of the polyethylene film described in the section “1. Heat-weldable film” in “A. First embodiment” above. is preferably

The total thickness of the heat-sealable film in this embodiment can be the same as the total thickness described in the section "1. Heat-sealable film" in "A. First Embodiment".

2. Gas Barrier Layer The gas barrier layer in the outer packaging material for the vacuum heat insulating material of this embodiment is arranged on one side of the heat-sealable film. Since the details of the gas barrier layer have been described in the section "2. Gas barrier layer" in "A. First embodiment", description thereof will be omitted here.

3. Arbitrary Configuration The outer packaging material for a vacuum heat insulating material of this aspect can have a protective film on the other outermost side in the thickness direction. In addition, the outer packaging material for a vacuum heat insulating material of this aspect may have an adhesive layer. The details of the protective film, and the position and material of the adhesive layer have been described in the section "3. Arbitrary configuration" of "A. First embodiment" above, so descriptions thereof will be omitted here.

4. Others The specific layer structure, water vapor permeability, oxygen permeability and thickness of the outer packaging material for the vacuum heat insulating material of this embodiment are described in the section "4. Others" of "A. First Embodiment" above. , the description here is omitted.

5. Manufacturing Method The manufacturing method of the outer packaging material for the vacuum insulation panel of this aspect has been described in the section "5. Manufacturing method" of the above "A. First embodiment", so the description will be omitted here.

6. Use The use of the outer packaging material for a vacuum heat insulating material of this aspect has been described in the section "6. Use" of the above "A. First embodiment", so the description will be omitted here.

II. Vacuum Insulating Material The vacuum insulating material of the present disclosure has a core material and an outer wrapping material that encloses the core material, and the outer wrapping material has a heat-sealable film and a gas barrier layer. In the vacuum insulation material of the present disclosure, the heat-sealable film is a polyethylene film having a melting rate at 40° C. of 3.0% or less in the first embodiment, and the heat-sealable film 1 is 70 The second embodiment is a polyethylene film having a melting rate at °C of 10.0% or less.

FIG. 2(a) is a schematic perspective view showing an example of the vacuum heat insulating material of the present disclosure, and FIG. 2(b) is a cross-sectional view taken along line XX of FIG. 2(a). In addition, in FIGS. 2(a) and 2(b), illustration of each constituent member of the outer packaging material is omitted. The vacuum heat insulating material 20 illustrated in FIGS. 2A and 2B has a core material 21 and an outer wrapping material 10 enclosing the core material 21, and a pair of outer wrapping materials facing each other with the core material 21 interposed therebetween. It has a sealing edge 22 formed by joining the peripheral edges of 10 . Reference numeral 22a indicates the end face of the seal end portion 22. As shown in FIG. The outer wrapping material 10 has a heat-sealable film and a gas barrier layer disposed on one side of the heat-sealable film (the side opposite to the core material 21). A first embodiment of the vacuum insulation material of the present disclosure is a polyethylene film in which the heat-sealable film has a melting rate of 3.0% or less at 40°C. In a second embodiment of the vacuum insulation material of the present disclosure, the heat-sealable film 1 is a polyethylene film having a melting rate of 10.0% or less at 70°C.

Hereinafter, the vacuum heat insulating material of the present disclosure will be described for each embodiment.

A. First embodiment The first embodiment of the vacuum insulation material of the present disclosure (hereinafter, in this section, may be referred to as the vacuum insulation material of this embodiment) has a core material and an outer wrapping material that encloses the core material. The outer packaging material has a heat-sealable film and a gas barrier layer, and the heat-sealable film is a polyethylene film having a melting rate at 40° C. of 3.0% or less.

According to the vacuum heat insulating material of this aspect, the outer wrapping material for enclosing the core material is the outer wrapping material for vacuum heat insulating material described in the section "A. First embodiment" of "I. outer wrapping material for vacuum heat insulating material" above. Therefore, in a high-humidity environment, especially in a temperature and high-humidity environment of around 40° C., good heat insulating performance can be exhibited for a long period of time.

Details of the vacuum heat insulating material of this aspect will be described below.

1. Outer Wrapping Material The outer wrapping material in the vacuum heat insulating material of this aspect is a member that encloses the core material. The outer wrapping material is the same as the outer wrapping material for vacuum heat insulating material described in the section "A. First embodiment" of "I. outer wrapping material for vacuum heat insulating material", so description thereof will be omitted here.

2. Core Material The core material in the vacuum heat insulating material of this aspect is a member enclosed by the outer wrapping material. Note that "to be enclosed" means to be sealed inside a bag body formed using an outer packaging material.

The material of the core material preferably has low thermal conductivity, and may be an inorganic material, an organic material, or a mixture of an organic material and an inorganic material. Specific examples of the material for the core material include granules, foamed resin, fibers, and the like, and these may be used singly or in combination of two or more.

3. Others In the vacuum heat insulating material of this aspect, a core material is enclosed in a bag formed of an outer wrapping material, and the sealed interior is decompressed to be 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 due to convection of air remaining inside can be reduced, and excellent heat insulating properties can be exhibited.

The lower the thermal conductivity of the vacuum heat insulating material of this aspect, the better. This is because heat is less likely to be conducted to the outside, and a high heat insulation effect can be achieved. The thermal conductivity of the vacuum insulation material of this aspect is preferably, for example, 5 mW/(m K) or less, more preferably 4 mW/(m K) or less, and 3 mW/(m K). ) or less. The thermal conductivity can be a value measured in accordance with JIS A1412-2:1999 under conditions of a high temperature side of 30°C, a low temperature side of 10°C, and an average temperature of 20°C.

4. Manufacturing method The method for manufacturing the vacuum insulation material of this aspect is particularly a method using the vacuum insulation material outer packaging material described in the section "A. First embodiment" of "I. Vacuum insulation material outer packaging material" above. Examples include, but are not limited to, the following methods. That is, two sheets of the outer wrapping material for vacuum insulating material described in the section "A. First embodiment" of "I. Outer wrapping material for vacuum insulating material" are prepared, and the respective heat-sealable films are faced to each other. The bags are stacked and the outer edges of the three sides are joined (heat-sealed) by heat welding to obtain a bag with one side open. After the core material is put into the bag from the opening, air is sucked from the opening, and the opening is joined and sealed by heat welding while the inside of the bag is decompressed to obtain the vacuum of this aspect. Insulation can be obtained.

B. Second embodiment The second embodiment of the vacuum insulation material of the present disclosure (hereinafter, in this section, may be referred to as the vacuum insulation material of this embodiment) has a core material and an outer wrapping material that encloses the core material. The outer packaging material has a heat-sealable film and a gas barrier layer, and the heat-sealable film is a polyethylene film having a melting rate at 70° C. of 10.0% or less.

According to the vacuum heat insulating material of this aspect, the outer wrapping material for enclosing the core material is the outer wrapping material for vacuum heat insulating material described in the section "B. Second embodiment" of "I. outer wrapping material for vacuum heat insulating material". Therefore, in a high-humidity environment, especially in an environment with a temperature of around 70° C. and a high humidity, it is possible to exhibit good heat insulation performance for a long period of time.

Details of the vacuum heat insulating material of this aspect will be described below.

1. Outer Wrapping Material The outer wrapping material in the vacuum heat insulating material of this aspect is a member that encloses the core material. The outer wrapping material is the same as the outer wrapping material for vacuum heat insulating material described in the section "B. Second embodiment" of "I. outer wrapping material for vacuum heat insulating material", so description thereof will be omitted here.

2. Core Material The core material in the vacuum heat insulating material of this aspect is a member enclosed by the outer wrapping material. Since the details of the core material have been described in the section "A. First Embodiment" above, description thereof will be omitted here.

3. Others Since the degree of vacuum and thermal conductivity inside the vacuum heat insulating material of this aspect have been described in the section "A. First embodiment" above, descriptions thereof will be omitted here.

4. Manufacturing method The method for manufacturing the vacuum insulation material of this aspect is particularly a method using the outer packaging material for vacuum insulation material described in the section "B. Second embodiment" of "I. External packaging material for vacuum insulation material". Examples include, but are not limited to, the method described in the section "4. Manufacturing method" of "A. First embodiment" above.

III. Article with Vacuum Insulation Material The article with vacuum insulation material of the present disclosure is roughly divided into two embodiments. Hereinafter, an article with a vacuum heat insulating material of the present disclosure will be described for each embodiment.

A. First embodiment The first embodiment of the article with a vacuum insulation material of the present disclosure (hereinafter sometimes referred to as the article with a vacuum insulation material of this embodiment in this section) includes an article having a thermal insulation region and a vacuum insulation material wherein the vacuum heat insulating material has a core material and an outer wrapping material that encloses the core material, the outer wrapping material has a heat-sealable film and a gas barrier layer, and the heat-sealable The film is a polyethylene film having a melting rate of 3.0% or less at 40°C.

According to the article with a vacuum heat insulating material of this aspect, the outer wrapping material constituting the vacuum heat insulating material provided in the article is the one explained in the section "A. First embodiment" of the above "I. outer wrapping material for vacuum heat insulating material". Therefore, in a high-humidity environment, especially in a high-humidity environment with a temperature of around 40°C, it is possible to exhibit good heat insulation performance for a long period of time. can do.

Hereinafter, each configuration of the article with a vacuum heat insulating material according to this aspect will be described. The vacuum heat insulating material in the article with the vacuum heat insulating material of this aspect and the outer packaging material used for the vacuum heat insulating material are described in "A. First embodiment" of "II. Vacuum heat insulating material" and "I. Since the detailed description has been given in the section "A. First embodiment" of "Outer Wrapping Material for Vacuum Insulator", the description will be omitted here.

The article in the article with vacuum insulation according to this aspect has a thermally insulating region. Here, the thermally insulated region is a region thermally insulated by a vacuum insulation material, and includes, for example, a heat-retained or cold-insulated region, a region surrounding a heat source or a cooling source, or a region isolated from a heat source or a cooling source. is. These regions can be space or objects. Examples of the above-mentioned goods include electrical equipment such as refrigerators, freezers, heat insulators, cold insulators, etc.; buildings, wall materials, building materials such as floor materials, and the like.

B. Second embodiment The second embodiment of the article with a vacuum insulation material of the present disclosure (hereinafter sometimes referred to as the article with a vacuum insulation material of this embodiment in this section) is an article having a thermal insulation region and a vacuum insulation material wherein the vacuum heat insulating material has a core material and an outer wrapping material that encloses the core material, the outer wrapping material has a heat-sealable film and a gas barrier layer, and the heat-sealable The film is a polyethylene film having a melting rate of 10.0% or less at 70°C.

According to the article with a vacuum heat insulating material of this aspect, the outer wrapping material constituting the vacuum heat insulating material provided in the article is the one described in the section "B. Second embodiment" of "I. Outer wrapping material for vacuum heat insulating material" above. Therefore, it can exhibit good heat insulation performance for a long time in a high humidity environment, especially in an environment with a temperature of around 70 ° C and a high humidity. can do.

In the article with a vacuum insulation material of this aspect, the vacuum insulation material and the outer packaging material used for the vacuum insulation material are the same as in "B. Second embodiment" of "II. Vacuum insulation material" and "I. Vacuum insulation material." This is the same as the first embodiment of the article with a vacuum insulation material, except that it is described in the section "B.

Note that the present disclosure is not limited to the above embodiments. The above embodiment is an example, and any device that has substantially the same configuration as the technical idea described in the claims of the present disclosure and achieves the same effect is the present invention. It is included in the technical scope of the disclosure.

EXAMPLES The present invention will be described in more detail below with reference to examples and comparative examples.

[Reference Examples 1 and 2, and Reference Comparative Examples 1 and 3]
The following polyethylene (PE) films A to E were prepared.
・ Polyethylene film A: LL-XHT (manufactured by Futamura Chemical Co., Ltd.)
・ Polyethylene film B: LIX-0 L6100 (Toyobo Co., Ltd.)
・ Polyethylene film C: DS-2 (manufactured by Tamapoly Co., Ltd.)
・ Polyethylene film D: VCS (manufactured by Mitsui Chemicals Tocello Co., Ltd.)
・ Polyethylene film E: MTNAS (manufactured by Futamura Chemical Co., Ltd.)

[Evaluation 1]
For polyethylene films A to E, the melting rate (%) at a temperature of 40 ° C., the melting rate (%) at a temperature of 70 ° C., and the water vapor transmission under the conditions of a temperature of 40 ° C. and a relative humidity difference of 90% RH are measured by the following methods. degree (hereinafter simply referred to as water vapor transmission rate) was measured. The results of evaluation 1 are shown in Table 1 below.

(melting rate)
According to JIS K7122 (1999), differential scanning calorimetry ("DSC204" manufactured by NETZSCH) is performed, 5 mg of a sample taken from a polyethylene film is placed in an aluminum cell, and -50 at a heating rate of 10 ° C./min under a nitrogen atmosphere. C. to 200.degree. C. (first temperature raising process), held at 200.degree. C. for 5 minutes, cooled to -50.degree. C. at a cooling rate of 10.degree. Thermogram obtained when the temperature is raised to 200 ° C. at a heating rate of 10 ° C./min (second heating process) (vertical axis: heat amount [J / g], horizontal axis: temperature [° C.]), second rise The melting peak area during the heating process was calculated. The melting peak area is the area of the portion surrounded by the melting curve and the baseline connecting the endothermic start temperature and the endothermic end temperature in the thermogram (chart diagram) of the second heating process. A straight line connecting the data point of the thermogram endothermic amount at 0° C. and the data point of the thermogram endothermic amount at 150° C. on the thermogram (chart diagram) of the second heating process was used. Also, from the melting peak area, the area of the temperature range below the temperature X (X=40° C. or 70° C.) was calculated. From the calculated melting peak area and the area of the temperature range below the temperature X (X = 40 ° C. or 70 ° C.), and the following formula (3), the melting rate (%) at a temperature of 40 ° C. and the melting rate at a temperature of 70 ° C. (%) were calculated respectively.
Melting rate (%) at temperature X (X = 40°C or 70°C) = {(area of temperature range below temperature X (X = 40°C or 70°C) in melting peak area)/(melting peak area) }×100 Expression (3)

(water vapor permeability)
The water vapor transmission rate of the polyethylene film is measured using a water vapor transmission rate measuring device (manufactured by MOCON, PERMATRAN-W Model 3/33G) according to JIS K7129-B: 2008 (plastic - film and sheet - method for determining water vapor transmission rate ( Instrument Measurement Method), Appendix B: Infrared Sensor Method), the transmission area was about 50 cm ² , the temperature was 40° C., and the relative humidity difference was 90% RH. At least three samples were measured for each polyethylene film, and the average of these measurements was taken as the water vapor permeability value for that polyethylene film.

From Table 1 above, polyethylene films A and B (Reference Examples 1 and 2) having a melting rate of 3.0% or less at 40 ° C. are compared with polyethylene films C to E (Reference Comparative Examples 1 to 3). It was confirmed that the film has a low water vapor permeability and exhibits high water vapor barrier performance in a high humidity environment at a temperature of around 40°C. Therefore, if the configuration of the outer packaging material for vacuum insulation material is the same except for the heat-sealable film, the outer packaging material for vacuum insulation material using polyethylene films A and B as the heat-sealable film is polyethylene film C to E is used as a heat-sealable film, it is speculated that high water vapor barrier performance can be exhibited in a high humidity environment at a temperature of around 40°C.

[Example 1]
(Preparation of outer wrapping material for vacuum insulation material)
An outer wrapping material for a vacuum heat insulating material was obtained, which had polyethylene film A, gas barrier film A, gas barrier film B, and gas barrier film C in this order, using polyethylene film A as a heat-sealable film. As the gas barrier films A to C, a polyethylene terephthalate film substrate (VM-PET1519 manufactured by Toray Advanced Film Co., Ltd.) having a thickness of 12 μm and having an aluminum film (Al film) having a thickness of 65 nm vapor-deposited on one side was used. The film was arranged so that it faced the gas barrier film B side, the gas barrier film B was arranged so that the Al film faced the gas barrier film A side, and the gas barrier film C was arranged so that the Al film faced the gas barrier film A side. . Each film was joined with an adhesive layer. The adhesive for forming the adhesive layer is a main agent mainly composed of polyester polyol (product name: RU-77T manufactured by Rock Paint Co., Ltd.) and a curing agent containing aliphatic polyisocyanate (product name: manufactured by Rock Paint Co., Ltd.). H-7) and a solvent of ethyl acetate were mixed in a weight ratio of main agent:curing agent:solvent=10:1:14 to use a two-liquid curing adhesive. The adhesive described above is applied to one surface of the film on the outer side so that the coating amount is 3.5 g / m ² to form an adhesive layer, and the outer side on which the adhesive layer is formed The film and the inner film were pressurized with an adhesive layer interposed therebetween.

(Production of vacuum insulation material)
Two sheets of the outer packaging material for a vacuum insulation material (dimensions: 360 mm x 450 mm) obtained in Example 1 are prepared, two sheets are stacked so that the heat-sealable films face each other, and the three sides of the quadrilateral are heat-sealed. Then, a bag having only one side opened was produced. Glass wool of 290 mm×300 mm×30 mm was used as the core material, and after drying treatment, the core material and 5 g of calcium oxide as a desiccant were placed in the bag, and the inside of the bag was evacuated. After that, the opening of the bag was sealed by heat sealing to obtain a vacuum heat insulating material. The ultimate pressure was set to 0.05 Pa.

[Example 2]
An outer packaging material for a vacuum heat insulating material and a vacuum heat insulating material were obtained in the same manner as in Example 1, except that the polyethylene film A was replaced with a heat-sealable polyethylene film B.

[Comparative Example 1]
An outer wrapping material for a vacuum heat insulating material and a vacuum heat insulating material were obtained in the same manner as in Example 1, except that the polyethylene film A was replaced with a polyethylene film C that could be heat-sealed.

[Comparative Example 2]
An outer packaging material for a vacuum heat insulating material and a vacuum heat insulating material were obtained in the same manner as in Example 1, except that the polyethylene film A was replaced with a heat-sealable polyethylene film D.

[Comparative Example 3]
An outer packaging material for a vacuum heat insulating material and a vacuum heat insulating material were obtained in the same manner as in Example 1, except that polyethylene film E was used as a heat-sealable film instead of polyethylene film A.

[Evaluation 2]
After storing the vacuum insulation materials obtained in Examples 1-2 and Comparative Examples 1-3 for 10 days in an atmosphere with a temperature of 70 ° C. and a humidity of 90% RH, a thermal conductivity measurement device (Autolamda HC-074, Eiko Seiki JIS A1412-2: 1999 (Method for measuring thermal resistance and thermal conductivity of thermal insulating material-Part 2: Heat flow meter method (HFM method))) was used to measure the thermal conductivity. . The measurement was carried out under the following conditions with the main surface of the vacuum heat insulating material facing up and down. At least three samples were measured for each example and comparative example, and the average of the measured values was taken as the thermal conductivity of the vacuum insulation material of the example or comparative example after wet heat deterioration. The results are shown in Table 2 below.
(Conditions for measuring thermal conductivity)
・ Time required for steady test: 15 minutes or more ・ Standard plate: EPS
・Temperature of hot surface: 30℃
・Temperature of cold surface: 10℃
・Average temperature of measurement sample: 20°C

From Tables 1 and 2 above, the vacuum insulation materials of Examples 1 and 2 in which polyethylene films A and B are heat-sealable films are comparative examples 1-3 in which polyethylene films C to E are heat-sealable films. Compared to the vacuum insulation material of No. 2, the thermal conductivity after wet heat deterioration was low, indicating that the insulation performance was excellent. This is because the outer packaging materials of the vacuum insulation materials of Examples 1 and 2 and Comparative Examples 1 and 3 have the same configuration except for the heat-sealable film, and the polyethylene film A in the vacuum insulation materials of Examples 1 and 2 and B, the melting rate at 70 ° C. was less than the predetermined value, whereas the polyethylene films C to E in Comparative Examples 1 to 3 had a melting rate at 70 ° C. higher than the predetermined value. A and B had higher water vapor barrier performance than polyethylene films C to E in an environment with a temperature of around 70°C and high humidity (specifically, a temperature of 70°C and a relative humidity difference of 90% RH). It is presumed to be due to

REFERENCE SIGNS LIST 1 : heat-sealable film 2 : gas barrier layer 11 : base material 12 : gas barrier film 10 : outer packaging material for vacuum insulation material 20 : vacuum insulation material 21 : core material 22 : seal edge

Claims (9)

It has a heat-sealable film and a gas barrier layer,
The heat-sealable film is a polyethylene film having a melting rate of 3.0% or less at 40°C. It has a heat-sealable film and a gas barrier layer,
The heat-sealable film is a polyethylene film having a melting rate of 10.0% or less at 70°C. 3. The outer packaging material for a vacuum heat insulating material according to claim 1, having three said gas barrier layers. A vacuum insulation material having a core material and an outer wrapping material that encloses the core material,
The outer packaging material has a heat-sealable film and a gas barrier layer,
The vacuum heat insulating material, wherein the heat-sealable film is a polyethylene film having a melting rate of 3.0% or less at 40°C. A vacuum insulation material having a core material and an outer wrapping material that encloses the core material,
The outer packaging material has a heat-sealable film and a gas barrier layer,
The vacuum heat insulating material, wherein the heat-sealable film is a polyethylene film having a melting rate of 10.0% or less at 70°C. The vacuum heat insulating material according to claim 4 or 5, wherein the outer wrapping material has three of the gas barrier layers. An article having a thermally insulated region and an article with vacuum insulation, comprising:
The vacuum heat insulating material has a core material and an outer wrapping material that encloses the core material,
The outer packaging material has a heat-sealable film and a gas barrier layer,
The article with a vacuum insulation material, wherein the heat-sealable film is a polyethylene film having a melting rate of 3.0% or less at 40°C. An article having a thermally insulated region and an article with vacuum insulation, comprising:
The vacuum heat insulating material has a core material and an outer wrapping material that encloses the core material,
The outer packaging material has a heat-sealable film and a gas barrier layer,
The article with a vacuum insulation material, wherein the heat-sealable film is a polyethylene film having a melting rate of 10.0% or less at 70°C. The article with a vacuum insulation material according to claim 7 or 8, wherein the outer wrapping material has three of the gas barrier layers.

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