JP7047820B2 - Outer packaging material for vacuum heat insulating material, vacuum heat insulating material, and articles with vacuum heat insulating material - Google Patents

Description

The present disclosure relates to an outer packaging material for a vacuum heat insulating material, a vacuum heat insulating material, and an article with the vacuum heat insulating material capable of forming the 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 a member in which the core material is arranged inside the bag of the outer packaging material and the inside of the bag is held in a vacuum state where the pressure is lower than the atmospheric pressure, and the internal heat convection is suppressed, which is good. Can demonstrate excellent heat insulation performance. The above-mentioned outer packaging material used for the vacuum heat insulating material will be described by referring to the outer packaging material for the vacuum heat insulating material or simply the outer packaging material.

The general vacuum heat insulating material outer packaging material adopts a structure including a gas barrier layer and a heat-weldable film as members, and a metal foil may be used for the gas barrier layer. In particular, among metal foils, aluminum alloy foils are used as a gas barrier layer because they have excellent gas barrier properties that suppress the permeation of gases such as oxygen and water vapor (Patent Document 1).

Japanese Unexamined Patent Publication No. 2018-53949

As the aluminum alloy foil, the present inventors, among the aluminum alloys of the alloy number A8079 specified in JIS H4160: 1994, the aluminum alloy foil corresponding to the basic symbol O specified in JIS H0001 (hereinafter, simply aluminum of A8079). (In some cases, it may be an alloy foil), but from the viewpoint of the physical properties exhibited by its composition, and because it is relatively inexpensive, we tried to use it as a gas barrier layer for the outer packaging material for vacuum heat insulating materials. However, it has been found that the vacuum heat insulating material using the vacuum heat insulating material outer packaging material using the aluminum alloy foil of A8079 may deteriorate the heat insulating performance when used for a long time.

The present disclosure is an invention made in view of the above problems, an outer packaging material for a vacuum heat insulating material capable of producing a vacuum heat insulating material capable of maintaining good heat insulating performance even when used for a long period of time, and a vacuum heat insulating material using the same. The main purpose is to provide articles with vacuum heat insulating materials.

The present disclosure is an outer packaging material for a vacuum heat insulating material having a heat-weldable film and an aluminum alloy foil arranged on one main surface side of the heat-weldable film. Among the aluminum alloys of alloy number A8079 specified in JIS H4160: 1994, the aluminum alloy foil corresponding to the basic symbol O specified in JIS H0001 is composed, and the area average of the crystal grains of the aluminum alloy contained in the aluminum alloy foil is average. Provided is an outer packaging material for a vacuum insulating material having a crystal area of 75 μm ² or less.

Further, the present disclosure provides a vacuum heat insulating material having a core material and an outer packaging material in which the core material is enclosed, wherein the outer packaging material is the above-mentioned vacuum heat insulating outer packaging material. ..

Further, the present disclosure is an article having a heat insulating region and an article with a vacuum heat insulating material provided with the vacuum heat insulating material, and the vacuum heat insulating material has 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-mentioned 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 producing a vacuum heat insulating material capable of maintaining good heat insulating performance.

It is a schematic cross-sectional view which shows an example of the outer packaging material for a vacuum heat insulating material of this disclosure. It is a schematic perspective view and sectional drawing which shows an example of the vacuum heat insulating material of this disclosure. It is a schematic diagram for demonstrating the method of performing the crystal analysis by the EBSD method of the aluminum alloy foil.

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings and the like. However, the present disclosure can be implemented in many different embodiments and is not construed as being limited to the description of the embodiments exemplified below. Further, in order to clarify the explanation, the drawings may schematically represent the width, thickness, shape, etc. of each part as compared with the embodiment, but this is merely an example and the interpretation of the present disclosure is limited. It's not something to do. Further, in the present specification and each figure, the same elements as those described above with respect to the above-mentioned figures may be designated by the same reference numerals, and detailed description thereof may be omitted as appropriate. Further, for convenience of explanation, the phrase "upper" or "lower" may be used for explanation, but the vertical direction may be reversed.

Further, in the present specification, there is no particular limitation 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. As long as this includes not only the case of being directly above (or directly below) the other configuration, but also the case of being above (or below) the other configuration, that is, separately above (or below) the other configuration. Including the case where the components of are included.

As for the vacuum heat insulating material, the outer packaging material for the vacuum heat insulating material may be bent at the time of its manufacture or use. Specifically, the portion corresponding to the corner portion of the core material of the vacuum heat insulating material outer packaging material, the folded portion of the heat-sealed portion of the vacuum heat insulating material outer packaging material, and the like are bent with a certain strain. In particular, when the vacuum heat insulating material is used, the folded portion of the heat seal portion is repeatedly bent with a constant strain. In order to make the vacuum heat insulating material capable of maintaining good heat insulating performance, the vacuum heat insulating material outer packaging material is an excellent gas barrier even when the bent portion is bent with a constant strain for a long period of time. It is required to have performance.

The present inventors have found that the aluminum alloy foil of A8079 used as a gas barrier layer for an outer packaging material may not have sufficient heat insulating properties after being repeatedly bent.

As a result of diligent studies to solve the above problems, the present inventors have found that the average crystal area of the crystal grains of the aluminum alloy is found in the aluminum alloy foil of A8079 as the gas barrier film of the outer packaging material for the vacuum heat insulating material. By using a vacuum heat insulating material having a size of 75 μm ² or less, the vacuum heat insulating material can be manufactured as an outer packaging material for a vacuum heat insulating material having excellent gas barrier performance even when bending is repeated, and a vacuum heat insulating material capable of maintaining good heat insulating performance can be manufactured. It was found that it would be an outer packaging material for heat insulating materials.
Hereinafter, the outer packaging material for the 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 in detail.

A. Outer packaging material for vacuum heat insulating material The outer packaging material for vacuum heat insulating material of the present disclosure has a heat-welding film and an aluminum alloy foil arranged on one main surface side of the heat-welding film. The aluminum alloy foil is an outer packaging material, and is made of an aluminum alloy foil corresponding to the basic symbol O specified in JIS H0001 among the aluminum alloys having the alloy number A8079 specified in JIS H4160: 1994. It is characterized in that the area average crystal area of the crystal grains of the aluminum alloy contained in the alloy foil is 75 μm ² or less.

FIG. 1 is a schematic cross-sectional view showing an example of the outer packaging material for the vacuum heat insulating material of the present disclosure. The outer packaging material 10 for a vacuum heat insulating material of the present disclosure includes a heat-weldable film 1 and an aluminum alloy foil 2 arranged on one main surface side of the heat-weldable film. In the example of FIG. 1, the protective layer 3 is further provided on the surface side of the aluminum alloy foil 2 opposite to the heat-weldable film 1.

In the present disclosure, the aluminum alloy foil is composed of an aluminum alloy foil corresponding to the basic symbol O specified in JIS H0001 among the aluminum alloys having the alloy number A8079 specified in JIS H4160: 1994, and is included in the aluminum alloy foil. The average crystal area of the crystal grains of the aluminum alloy is 75 μm ² or less.

In the case of the outer packaging material for the vacuum heat insulating material of the present disclosure, since the area average crystal area of the crystal grains of the aluminum alloy contained in the aluminum alloy foil is 75 μm ² or less, excellent gas barrier performance is obtained even when bending is repeated. Will have. This is because the crystal grains of the aluminum alloy are relatively small and there are many interfaces between the crystal grains, so that the stress is dispersed when external stress such as bending or twisting is applied during bending, which causes cracks and the like. It is presumed that this is because the generation can be suppressed and the deterioration of the gas barrier performance can be suppressed.

On the other hand, when the area average crystal area of the aluminum alloy crystal grains contained in the aluminum alloy foil is larger than the above range, the interface of the crystal particles is small, that is, large particles are present, so that external stress is applied. There is a high possibility that stress concentration will occur in the aluminum. In the portion where such stress is concentrated, fine cracks are likely to occur, and it is presumed that the fine cracks grow and become cracks or the like due to bending for a long time, and as a result, the gas barrier performance deteriorates.

Hereinafter, each configuration of the vacuum heat insulating material outer packaging material in the present disclosure will be described in detail.
1. 1. Aluminum Alloy Foil The aluminum alloy foil in the present disclosure is arranged on one main surface side of a heat-weldable film, has a function as a gas barrier film, and has an alloy number A8079 specified in JIS H4160: 1994. Among the alloys, the alloy is made of an aluminum alloy foil corresponding to the basic symbol O specified in JIS H0001.

Further, the aluminum alloy foil in the present disclosure is characterized in that the area average crystal area of the crystal grains of the aluminum alloy (hereinafter, also referred to as aluminum crystal grains) is 75 μm ² or less. Area The average crystal area is preferably 55 μm ² or less, more preferably 45 μm ² or less.
The lower limit of the area average crystal area is not particularly limited, but is preferably 10 μm ² or more, and more preferably 20 μm ² or more.

In the present disclosure, the area average crystal area is a direction perpendicular to the rolling direction of the aluminum alloy foil, and the cross section obtained by cutting the aluminum alloy foil in the direction perpendicular to the surface of the aluminum alloy foil is referred to as EBSD ( It is an average value obtained by concatenating a plurality of images obtained by performing crystal analysis by the Electron Backscatter Diffraction Patterns method and weighting the crystal area included in the measurement region of about 10,000 μm ² or more by the area.

Here, the rolling direction of the aluminum alloy foil corresponds to the RD when the aluminum alloy foil is manufactured through the rolling process. In the rolling direction of the aluminum alloy foil, linear streaks, so-called rolling marks, are formed on the surface of the aluminum alloy foil. Since the rolling marks extend along the rolling direction, the rolling direction of the aluminum alloy foil can be grasped by observing the surface of the aluminum alloy foil with a metal microscope or the like.

FIG. 3 shows a schematic diagram for explaining a method of performing crystal analysis by the EBSD method for the cross section of the aluminum alloy foil. In FIG. 3, a sample of the aluminum alloy foil 30 is installed so that Axis1 is ND, Axis2 is TD, and Axis3 is RD, and electrons are received from the objective lens 41 of the SEM with respect to the cross section 30a of the aluminum alloy foil 30. The line 41a is irradiated, and the crystal analysis is performed from the Axis3 direction by the EBSD detector 40. The angle formed by each of Axis1, Axis2, and Axis3 is 90 °, and the sample of the aluminum alloy foil 30 is tilted 70 ° in the Axis1 direction. Specific measuring devices, pretreatment methods, and measurement conditions are as follows. The RD (Rolling Direction) is the rolling direction of the aluminum alloy foil, and the ND (Normal Direction) is the direction perpendicular to the rolling direction (RD) of the aluminum alloy foil, which is the direction perpendicular to the surface of the aluminum alloy foil. TD (Transverse Direction) is a direction perpendicular to the same plane as ND and RD.

(measuring device)
A device equipped with an EBSD detector (manufactured by TSL Solutions Co., Ltd.) is used for the Schottky field emission scanning electron microscope.

(Preprocessing)
As a pretreatment, the aluminum alloy foil is cut in the direction perpendicular to the rolling direction (RD) to obtain a cross section. The rolling direction of the aluminum alloy foil is the direction in which the linear rolling marks are extended by observing the glossy surface of the aluminum alloy foil with a metallurgical microscope. As a specific procedure, first, the aluminum alloy foil as a sample is cut out to 5 mm (direction perpendicular to the rolling direction) × 10 mm (rolling direction) with a trimming razor or a metal cutting scissors, and then embedded in a resin. .. Next, using a trimming razor or a metal cutting scissors, the aluminum alloy foil is cut together with the resin in the direction perpendicular to the rolling direction of the aluminum alloy foil and in the direction perpendicular to the surface of the aluminum alloy foil to form the aluminum alloy foil. To expose the cross section of. Next, the obtained cross section is trimmed using a microtome (an ultramicrotome manufactured by Leica Microsystems). In this trimming, in order to reduce the mechanical distortion of the cross-sectional shape, the material is cut with the embedded resin by a microtome about 1 mm in the direction perpendicular to the cross-sectional direction. Next, using an ion milling device (manufactured by Hitachi High-Technologies Corporation), a broad argon beam is irradiated in the direction perpendicular to the cross section under the conditions of a protrusion width of 50 μm, a voltage of 6 kV, and 4 hours to prepare a measurement cross section. .. This is the work of precisely exposing the cross section of the aluminum alloy foil so as to minimize the damage to the mechanical crystal structure that occurs in the previous process.

(SEM condition)
The conditions of the scanning electron microscope (SEM) used in the EBSD method are as follows.
Observation magnification: 3000 times
Acceleration voltage: 15kV
Working distance: 15mm
Tilt angle: 70 °

(EBSD condition)
The conditions for crystal analysis by the EBSD method are as follows.
Step size: 200nm

(analysis method)
Using the crystal orientation analysis software OIM (Ver.7.3) manufactured by TSL Solutions Co., Ltd., the analysis can be performed as follows.
A plurality of images are connected, and the measurement area is about 10,000 μm ² or more. At this time, the measurement region is from the center to both ends in the thickness direction of the aluminum alloy foil, and the portion where the resin adheres to the cross section and the portion where the acid resistant film exists are excluded from the measurement region.
Confidence index (CI value) defined by crystal orientation analysis software OIM manufactured by TSL Solutions Co., Ltd. After excluding data with a CI value of 0.1 or less, each crystal grain measured by OIM The area average crystal area is calculated from the crystal grain area.

The area average crystal area is an average value obtained by weighting the crystal areas of a plurality of aluminum crystal grains included in the measurement region of the cross section of the exposed aluminum alloy foil by the crystal area. That is, it is a value obtained by dividing the sum of the squares of the crystal areas of the aluminum crystal grains by the sum of the crystal areas of the aluminum crystal grains.
The "crystal grains" refer to individual crystals of the polycrystalline structure constituting the aluminum alloy foil.

Specifically, the area average crystal area X (μm ² ) is calculated by the following formula.
X = (A1 ² + A2 ² + A3 ² ... + An ² ) / (A1 + A2 + A3 ... + An)
(In the formula, A1 to An are the areas of each aluminum crystal grain contained in the measurement region of the cross section, respectively. N is the total number of aluminum crystal grains included in the measurement region of the cross section.)

The area average crystal area is distinguished from the normal average crystal area (μm ² ). The normal average crystal area Y is a value calculated by dividing the total area of aluminum crystal grains included in the measurement region of the cross section by the number of aluminum crystal grains, which is calculated by the following formula.
Y = (A1 + A2 + A3 ... + An) / n
The average crystal area Y is a simple average value in which both large-area crystal grains and small-area crystal grains are considered equally, but the area average crystal area used in the present disclosure is obtained by weighting the crystal area by the area. Since it is an average value, it is a value that is in line with the actual state of the crystal grains of the aluminum alloy in the measurement area.

The thickness of the aluminum alloy foil in the present disclosure is not particularly limited, and is preferably 2 μm or more and 50 μm or less, and particularly preferably 5 μm or more and 12 μm or less, from the viewpoint of being preferably used as the outer packaging material for the vacuum heat insulating material.

2. 2. Heat-weldable film In the outer packaging material for vacuum heat insulating material of the present disclosure, a heat-weldable layer is arranged on one main surface side. Such a heat-weldable film is a film that can be welded by heating. The heat-weldable film is a member that bears one surface in the thickness direction of the vacuum heat insulating material outer packaging material, and is used as a core material when the vacuum heat insulating material outer packaging material of the present disclosure is used to produce the vacuum heat insulating material. It is a member that joins the ends of the outer packaging materials for vacuum heat insulating materials that are in contact with each other and that are opposed to each other when the core material is sealed.

As the heat-weldable film, a resin film that can be melted and fused by heating can be used. For example, polyethylene such as linear short-chain branched polyethylene (LLDPE) or unstretched polypropylene (CPP) can be used. ) Etc., Polyethylene terephthalate (PET), Polyethylene naphthalate (PEN), Polybutylene terephthalate (PBT) and other polyester resin films, Polyvinyl acetate resin film, Polyvinyl chloride resin film, Poly ( Meta) Examples thereof include acrylic resin films and urethane resin films.

The heat-weldable film may contain other materials such as an anti-blocking agent, a lubricant, a flame retardant, and a filler.

The thickness of the heat-weldable film may be any thickness as long as it can obtain a desired adhesive force when the outer packaging materials for vacuum heat insulating materials are bonded to each other, for example, in the range of 15 μm or more and 100 μm or less, preferably 25 μm. The range may be 90 μm or less, more preferably 30 μm or more and 80 μm or less.

3. 3. Arbitrary configuration (1) Protective film The outer packaging material for the vacuum heat insulating material of the present disclosure is arranged on the opposite side of the heat-weldable film of the gas barrier film, and a protective film for protecting the outside of the gas barrier film is arranged. It is preferable to have.

Examples of the main component material of such a protective film include polyester resins such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN) and polybutylene terephthalate (PBT), and polyamide resins such as nylon. ..

The thickness of the protective film is not particularly limited, but may be, for example, 5 μm or more, 10 μm or more, 200 μm or less, and 100 μm or less. One protective film may be arranged on the side opposite to the heat-weldable film of the gas barrier film, or two or more protective films may be laminated.

(2) Adhesive layer The outer packaging material for the vacuum heat insulating material of the present disclosure may have an adhesive layer. The adhesive layer can be located, for example, between a heat-weldable film and an aluminum alloy foil, between an aluminum alloy foil and a protective film, and the like. As the material of the adhesive layer, conventionally known pressure-sensitive adhesives, thermoplastic adhesives, curable adhesives and the like can be used.

The adhesive constituting the adhesive layer is usually a two-component curable adhesive containing a main agent and a curing agent, but is not limited thereto. For example, a one-component curable adhesive mixed with a main agent and a latent curing agent blocked by a known method so as not to react when mixed with the main agent, or a known curing agent so as not to react when mixed. It may be a one-component curable adhesive in which a latent main agent blocked by the method and a curing agent are mixed.

Specific examples of the adhesive constituting the adhesive layer include an epoxy adhesive, a polyvinyl acetate adhesive, a polyacrylic acid ester adhesive, a cyanoacrylate adhesive, an ethylene copolymer adhesive, and cellulose. Adhesives, polyester adhesives, polyamide adhesives, polyimide adhesives, amino resin adhesives, phenol resin adhesives, polyurethane adhesives, reactive (meth) acrylic acid adhesives, inorganic rubber adhesives An adhesive, a silicone-based adhesive, an inorganic adhesive made of an alkali metal silicate, low melting point glass, or the like can be used.

In particular, as the adhesive, a polyacrylic acid ester-based adhesive, a polyurethane-based adhesive, or the like is preferable, and in particular, the above-mentioned adhesive is preferably a compound having an isocyanate group as a functional group, and specifically, a polyurethane-based adhesive. It is preferably an adhesive.

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

The thickness of the adhesive layer may be any thickness as long as it can exhibit a desired adhesive force, and can be appropriately set according to the composition of the adhesive layer and the like. Usually, the thickness is preferably about 0.1 g / m ² to 10 g / m ² in a dry state.

As the adhesive layer, a sheet or film formed by the above-mentioned adhesive may be used, and a coating liquid prepared by mixing the above-mentioned adhesive with a desired solvent is prepared, and one of a heat-weldable film or an aluminum alloy foil is prepared. It may be applied directly to the surface, dried and cured to form.

4. Others (1) Oxygen permeability The outer packaging material for the vacuum heat insulating material of the present disclosure has an oxygen permeability of 0.1 cc / (m ² · day · atm) or less under the conditions of a temperature of 23 ° C. and a humidity of 60% RH. It can be 0.01 cc / ( ^m2 · day · atm) or less.

For oxygen permeability, refer to JIS K7126-2: 2006 (Plastic-film and sheet-gas permeability test method-Part 2: isobaric method, Annex A: oxygen gas permeability test method by electrolytic sensor method). , The value is measured under the conditions of a temperature of 23 ° C. and a humidity of 60% RH using an oxygen gas permeability measuring device. The oxygen permeability can be measured as follows.

First, a sample of the vacuum heat insulating material outer packaging material cut to a desired size is placed so that the outermost layer of the outermost surfaces facing each other in the thickness direction (lamination direction) is in contact with oxygen gas on the side opposite to the heat-weldable film. The arrangement is performed by adjusting the conditions of the permeation area of about 50 cm ² (permeation area: circle with a diameter of 8 cm), the carrier gas and the test gas to 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, and then the test gas (at least 99.5% dry oxygen) was flowed, and the time from the start of the flow to the reaching the equilibrium state was 12 hours. After securing, start the measurement. As the oxygen gas permeability measuring device, for example, "OXTRAN" manufactured by MOCON of the United States can be used. The measurement of oxygen permeability is performed for at least three samples for one vacuum heat insulating outer packaging material, and the average of those measured values is taken as the value of oxygen permeability under the conditions.

The outer packaging material for the vacuum heat insulating material of the present disclosure has excellent gas barrier performance even after bending, and in particular, the oxygen permeability under the conditions of temperature 100 ° C. and humidity 0% RH after the bending test performed 100 times refraction treatment. , 50 cc / (m ² · day · atm) or less, especially 40 cc / (m ² · day · atm) or less. This makes it possible to obtain a vacuum heat insulating material that can maintain good heat insulating performance.

In the present disclosure, in the bending test, a rectangular sample having a width of 210 mm and a length of 297 mm (A4 size) is cut out, both ends in the width direction are bonded together, rolled into a cylindrical shape, and used as a test piece. Then, both ends of this test piece are held by the fixed head and drive head of a gelboflex tester (manufactured by Tester Sangyo Co., Ltd., model name BE1006), and fixed while twisting at an angle of 440 degrees in accordance with ASTM F392. Reduce the head-to-drive head spacing from 7 inches to 3.5 inches, then reduce the head spacing to 1 inch while maintaining a further twist, and then increase the head spacing to 3.5 inches. Then, the reciprocating motion of widening the head spacing to 7 inches while returning the twist is performed 100 times at a speed of 40 times / min at a temperature of 25 ° C.

As described above, the outer packaging material for the vacuum heat insulating material of the present disclosure has the above-mentioned excellent gas barrier performance even after many bendings are repeated. Therefore, in particular, the aluminum alloy foil is cracked at the bent portion corresponding to the corner portion of the core material of the vacuum heat insulating material outer packaging material and the folded portion of the heat seal portion of the vacuum heat insulating material outer packaging material. It is hard to occur and the gas barrier performance is kept good.

Examples of the method for manufacturing the outer packaging material for the vacuum heat insulating material of the present disclosure include a method of bonding a pre-manufactured aluminum foil and each film via the above-mentioned adhesive layer. Further, the outer packaging material for the vacuum heat insulating material of the present disclosure may be manufactured by sequentially extruding and laminating the raw materials of the heat-melted films with a T-die or the like.

The outer packaging material for the vacuum heat insulating material of the present disclosure can be used as the vacuum heat insulating material. In the vacuum heat insulating material, the outer packaging material for the vacuum heat insulating material of the present disclosure can be used by arranging them facing each other via the core material so that the heat-weldable film is on the core material side.

B. 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 for enclosing the core material, and the outer packaging material is the above-mentioned "A. Outer packaging material for vacuum heat insulating material". It is characterized by being the one described in the section.

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 sectional view taken along the line XX of FIG. 2 (a). The vacuum heat insulating material 20 exemplified in FIG. 2 has a core material 11 and an outer packaging material 10 for enclosing the core material 11, and the outer packaging material 10 is the outer packaging material for the vacuum heat insulating material described with reference to FIG. The vacuum heat insulating material 20 is a bag body in which two outer packaging materials 10 face each other so that the heat-weldable films face each other, and the end portions 12 are joined by heat welding. The core material 11 is enclosed, and the inside of the bag body is depressurized.

According to the present disclosure, the outer packaging material for enclosing the core material is the outer packaging material for the vacuum heat insulating material described in the above-mentioned "A. Outer packaging material for vacuum heat insulating material", thereby maintaining good heat insulating performance. It becomes a vacuum heat insulating material that can be used.
Hereinafter, the vacuum heat insulating material of the present disclosure will be described for each configuration.

1. 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 the vacuum heat insulating material described in the above-mentioned "A. Outer packaging material for vacuum heat insulating material". The explanation is omitted.

2. 2. Core material The core material in the present disclosure is a member enclosed by an outer packaging material. It should be noted that "sealing" means that the bag is sealed inside a bag formed by using the outer packaging material.

The core material preferably has a low thermal conductivity. The core material has a porosity of 50% or more, especially 9
It can be a porous material of 0% or more.

As a material constituting the core material, powder, foam, fiber, or the like can be used. The powder may be inorganic or organic, and for example, dry silica, wet silica, aggregated silica powder, conductive powder, calcium carbonate powder, pearlite, clay, talc and the like can be used.

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

3. 3. Others In the vacuum heat insulating material of the present disclosure, the core material is enclosed inside the outer packaging material, and the inside is decompressed to a vacuum state. The degree of vacuum inside the vacuum heat insulating material is preferably 5 Pa or less, for example. This is because the heat conduction due to the convection of the air remaining inside can be lowered, and excellent heat insulating properties can be exhibited.

The lower the thermal conductivity of the vacuum heat insulating material, the more preferable. For example, the thermal conductivity (initial thermal conductivity) is preferably 5 mW / (mK) or less. This is because the vacuum heat insulating material is less likely to conduct heat to the outside and can exert a high heat insulating effect. Above all, the initial thermal conductivity is more preferably 4 mW / (mK) or less. The thermal conductivity shall be a value measured under the conditions of 30 ° C. on the high temperature side, 10 ° C. on the low temperature side, and an average temperature of 20 ° C. in accordance with JIS A1412-2: 1999.

Further, since the vacuum heat insulating material of the present disclosure uses the above-mentioned outer packaging material for the vacuum heat insulating material, deterioration of the heat insulating performance is suppressed.

As the method for producing the vacuum heat insulating material of the present disclosure, a general method can be used. For example, two sheets of the vacuum heat insulating material outer packaging material described in the above-mentioned "A. Vacuum heat insulating material outer packaging material" are prepared, and the heat-weldable films are overlapped with each other facing each other, and the outer edges of the three sides are overlapped. It is heat-welded to obtain a bag body with one side open. A vacuum heat insulating material can be obtained by inserting the core material into the bag through the opening, sucking air through the opening, and sealing the opening with the inside of the bag decompressed.

The vacuum heat insulating material of the present disclosure can be used, for example, for an article requiring heat extinction. The above articles will be described later.

C. The article with the vacuum heat insulating material The article with the vacuum heat insulating material of the present disclosure is an article having a heat insulating region and an article with a vacuum heat insulating material provided with the vacuum heat insulating material. The outer packaging material is the outer packaging material for the vacuum heat insulating material described in the above-mentioned "A. Outer packaging material for vacuum heat insulating material".

According to the present disclosure, the vacuum heat insulating material used for the article is composed of the outer packaging material described in the section "A. Vacuum heat insulating material outer packaging material", and in the process of manufacturing or using the vacuum heat insulating material, Even when the outer packaging material has a bent portion, deterioration of the gas barrier performance at the bent portion can be suppressed. Therefore, the vacuum heat insulating material can exhibit good heat insulating performance for a long period of time, and when the article is provided with such the vacuum heat insulating material, the article or the object in which the article is used in a high temperature and high humidity environment is used. Energy saving can be achieved.

The vacuum heat insulating material and the outer packaging material used therein have been described in detail in the sections "B. Vacuum heat insulating material" and "A. Vacuum heat insulating material outer packaging material" described above, and thus the description thereof is omitted here. do.

The article in the present disclosure has a heat insulating region. Here, the heat-insulated region is a region that is heat-insulated by the 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, and a region that is isolated from a heat source or a cooling source. Is. These areas may be spaces or objects.

Examples of the above-mentioned articles include electric devices such as refrigerators, freezers, warmers, and coolers, heat-retaining containers, cold-retaining containers, transport containers, containers, containers such as storage containers, vehicles such as vehicles, aircraft, and ships, houses, and warehouses. Building materials such as buildings, wall materials, floor materials, etc.

The present disclosure is not limited to the above embodiment. The above embodiment is an example, and any object having substantially the same structure as the technical idea described in the claims of the present disclosure and having the same effect and effect is the present invention. Included in the technical scope of the disclosure.

Examples and comparative examples are shown below, and the present disclosure will be described in more detail.

[material]
The members and adhesives constituting the vacuum heat insulating outer packaging materials of Examples and Comparative Examples are shown below and in Table 1.
(Member: Aluminum alloy foil)
-Aluminum alloy foil 1: Of the aluminum alloys with alloy number A8079 specified in JIS H4160: 1994, aluminum alloy foils corresponding to the basic symbol O specified in JIS H0001 (product name aluminum foil, Rakuyo Manki Aluminum Processing Co., Ltd.) Made by Ltd., film thickness: 6 μm)
-Aluminum alloy foil 2: Of the aluminum alloys with alloy number A8079 specified in JIS H4160: 1994, aluminum alloy foils corresponding to the basic symbol O specified in JIS H0001 (product name AA8079-O, manufactured by Kunshan Aluminum Co., Ltd.) , Film thickness: 6 μm)
-Aluminum alloy foil 3: Of the aluminum alloys with alloy number A8079 specified in JIS H4160: 1994, aluminum alloy foils corresponding to the basic symbol O specified in JIS H0001 (product name A8079-O, Hangzhou Gosei Aluminum Co., Ltd.) Made, film thickness: 6 μm)
-Aluminum alloy foil 4: Of the aluminum alloys of alloy number A8079 specified in JIS H4160: 1994, aluminum alloy foils corresponding to the basic symbol O specified in JIS H0001 (product name aluminum foil (8079 for general use), Made by UACJ Co., Ltd., film thickness: 6 μm)

(Member: Heat-weldable film)
-Heat-weldable film A: Linear low-density polyethylene film (trade name: TUX-HCE, manufactured by Mitsui Chemicals Tocello Co., Ltd., thickness 50 μm)

(Member: protective layer)
-Protective film A: Nylon film (trade name: emblem ON, manufactured by Unitika Ltd., thickness 25 μm)
-Protective film B: Polyethylene terephthalate film (trade name: Emblet PTMB, manufactured by Unitika Ltd., thickness 12 μm)

[Example 1]
An outer packaging material 1 for a vacuum heat insulating material having a protective layer film A, a protective layer film B, an aluminum alloy foil 1, and a heat-weldable film A in this order was obtained.

[Example 2]
An outer packaging material 2 for a vacuum heat insulating material having a protective layer film A, a protective layer film B, an aluminum alloy foil 2, and a heat-weldable film A in this order was obtained.

[Example 3]
An outer packaging material 3 for a vacuum heat insulating material having a protective layer film A, a protective layer film B, an aluminum alloy foil 3, and a heat-weldable film A in this order was obtained.

[Comparison example]
An outer packaging material 4 for a vacuum heat insulating material having a protective layer film A, a protective layer film B, an aluminum alloy foil 4, and a heat-weldable film A in this order was obtained.

Each film was bonded with an adhesive. As the adhesive, a trade name: RU-77T / H-7, manufactured by Rock Paint Co., Ltd. was used.

In the production of the outer packaging material for a vacuum heat insulating material, first, an adhesive is applied to one surface of the protective film A, and the film is dried to evaporate the solvent to form an adhesive layer on the protective film A to form a protective film. By pressing the adhesive layer of A and the protective film B from both sides, the protective film A and the protective film B were joined by the adhesive. Next, an adhesive was applied to the other surface of the protective film B, and then dried to evaporate the solvent to form a layer of the adhesive on the protective film B. Next, the protective film A, the protective film B, and the aluminum alloy foil were joined by the adhesive by pressing the adhesive layer of the protective film B and the aluminum alloy foil from both sides. In the same procedure, after forming a layer of adhesive on the aluminum alloy foil, a heat-weldable film was joined to complete the outer packaging material for the vacuum heat insulating material.

(Area average crystal area)
For the aluminum alloy foils 1 to 4, the area average crystal area of the crystal grains of the aluminum alloy was measured as follows. The results are shown in Table 1.
Area of crystal grain The average crystal area is an average value obtained by concatenating a plurality of images acquired by crystal analysis by the EBSD method and weighting the crystal area included in the measurement region having a measurement area of about 10,000 μm ² or more by the area. The pretreatment method and measurement conditions are shown below.

(Preprocessing)
As a pretreatment, aluminum alloy foils 1 to 4 were cut in a direction perpendicular to the rolling direction (RD) to obtain a cross section. The rolling direction of the aluminum alloy foil is the direction in which the linear rolling marks are extended by observing the glossy surface of the aluminum alloy foil with a metallurgical microscope. As a specific procedure, first, the aluminum alloy foil as a sample is cut out to 5 mm (direction perpendicular to the rolling direction) × 10 mm (rolling direction) with a trimming razor or a metal cutting scissors, and then embedded in a resin. rice field. Next, using a trimming razor or a metal cutting scissors, the aluminum alloy foil is cut together with the resin in the direction perpendicular to the rolling direction of the aluminum alloy foil and in the direction perpendicular to the surface of the aluminum alloy foil, and the aluminum alloy foil is formed. The cross section of was exposed. Next, the obtained cross section was trimmed using a microtome (an ultramicrotome manufactured by Leica Microsystems). In this trimming, in order to reduce the mechanical distortion of the cross-sectional shape, the material was cut with a microtome about 1 mm in the direction perpendicular to the cross-sectional direction together with the embedded resin. Next, using an ion milling device (manufactured by Hitachi High-Technologies Corporation), a broad argon beam was irradiated in the direction perpendicular to the cross section under the conditions of a protrusion width of 50 μm, a voltage of 6 kV, and 4 hours to prepare a measurement cross section. .. This is the work of precisely exposing the cross section of the aluminum alloy foil so as to minimize the damage to the mechanical crystal structure that occurs in the previous process.

(measuring device)
A device equipped with an EBSD detector (manufactured by TSL Solutions Co., Ltd.) was used for the Schottky field emission scanning electron microscope.

(SEM condition)
The conditions of the scanning electron microscope (SEM) used in the EBSD method are as follows.
Observation magnification: 3000 times
Acceleration voltage: 15kV
Working distance: 15mm
Tilt angle: 70 °

(EBSD condition)
The conditions for crystal analysis by the EBSD method are as follows.
Step size: 200nm

The following analysis was carried out using the crystal orientation analysis software OIM (Ver.7.3) manufactured by TSL Solutions Co., Ltd.
A plurality of images were connected, and the measurement area was set to about 10,000 μm ² or more. At this time, the measurement region was defined from the center to both ends in the thickness direction of the aluminum alloy foil, and the portion where the resin adhered to the cross section and the portion where the acid resistant film was present were excluded from the measurement region.
Confidence index (CI value) defined by crystal orientation analysis software OIM manufactured by TSL Solutions Co., Ltd. After excluding data with a CI value of 0.1 or less, the area of each crystal grain is measured by OIM. The average crystal area of the crystal grains was calculated based on the formula described in the above section "A. Outer packaging material for vacuum heat insulating material I. Aluminum alloy foil".

[Gas barrier performance test after bending]
For each of the vacuum heat insulating outer packaging materials obtained in Examples 1 to 3 and Comparative Example, rectangular test pieces (number of test pieces N = 1) having a width of 210 mm and a length of 297 mm (A4 size) were collected. In accordance with ASTM F392, each test piece was bent 100 times using a gelboflex tester (manufactured by Tester Sangyo Co., Ltd., model name: BE1006).

(Oxygen permeability)
For each of the test pieces after bending the outer packaging materials 1 to 4 for the vacuum heat insulating materials obtained in Examples 1 to 3 and Comparative Examples 100 times, the above-mentioned "A. Outer packaging material for vacuum heat insulating material 4. Vacuum heat insulating material". The oxygen permeability (oxygen permeability after bending treatment) was measured under the conditions of a temperature of 100 ° C. and a humidity of 0% RH by the method described in the section "(1) Oxygen permeability". The results are shown in Table 1.

As shown in Table 1, the vacuum heat insulating material (Examples 1 to 3) having the vacuum heat insulating material outer packaging material of the present disclosure has gas barrier properties even after bending treatment as compared with the vacuum heat insulating material outer packaging material of the comparative example. It became an excellent one.

1 ... Heat-weldable film 2 ... Aluminum alloy foil 3 ... Protective film 10 ... Outer packaging material for vacuum heat insulating material 11 ... Core material 20 ... Vacuum heat insulating material

Claims (5)

An outer packaging material for a vacuum heat insulating material having a heat-weldable film and an aluminum alloy foil arranged on one main surface side of the heat-weldable film.
The aluminum alloy foil is made of an aluminum alloy foil corresponding to the basic symbol O specified in JIS H0001 among the aluminum alloys having the alloy number A8079 specified in JIS H4160: 1994.
An outer packaging material for a vacuum heat insulating material, wherein the area average crystal area of the crystal grains of the aluminum alloy contained in the aluminum alloy foil is 75 μm ² or less. The outer packaging material for a vacuum heat insulating material according to claim 1, wherein the area average crystal area is 55 μm ² or less. The outer packaging material for a vacuum heat insulating material according to claim 1 or 2, wherein the protective film is provided on the surface side of the aluminum alloy foil opposite to the heat-weldable film. A vacuum heat insulating material having a core material and an outer packaging material in which the core material is enclosed.
The vacuum heat insulating material, wherein the outer packaging material is the vacuum heat insulating outer packaging material according to any one of claims 1 to 3. An article having a heat insulating region and an article with a vacuum heat insulating material provided with the vacuum heat insulating material.
The vacuum heat insulating material has a core material and an outer packaging material in which the core material is enclosed.
An article with a vacuum heat insulating material, wherein the outer packaging material is the outer packaging material for vacuum heat insulating according to any one of claims 1 to 3.

Images