JPH11257576A - Vacuum insulation material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a vacuum insulation material which has an excellent heat insulating property at the initial phase, and can maintain the heat insulating property for a long period. SOLUTION: This vacuum insulation material is formed by sealing the end of a laminate body having at least one layer each of a resin including layer (A layer) with a gas barrier property to satisfy the formula: W.λ.P<1×10<-6> (where W, λ, and P in the formula are the thickness (m) of the A layer, the conductivity (W/m.K) of the A layer, and the oxygen permeability (cc/m2.day.atm) at 23 deg.C and 50% RH at the thickness W of the A layer); a thermal fusion layer; and a metal foil respectively, and by providing a hollow part, and the metal foil is divided into the heat flowing-in side and the heat flowing- out side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a vacuum heat insulating material.

[0002]

2. Description of the Related Art A method of evacuating the inside of a structure sealed with a container or an outer wrapping material formed of a gas barrier material to enhance the heat insulating effect has been conventionally known. A vacuum heat insulating material in which a core material is filled in the inside of the structure and evacuated is also known. In such a vacuum heat insulating material, the gas heat transfer is reduced by maintaining the inside at a high degree of vacuum to improve the heat insulating property.In order to maintain the heat insulating property for a long time, for example, the above-described structure is used. It is necessary to use a material having extremely excellent gas barrier properties for the body.

As such a material, a resin, particularly a thermoplastic resin, is preferably used from the viewpoint of moldability, but PVDC (polyvinylidene chloride) or EVOH (ethylene-vinyl acetate copolymer) which is a typical example of a resin having excellent gas barrier properties is used. However, the gas barrier properties of the unified saponified product and the like are insufficient as a vacuum heat insulating material, and it has been difficult to maintain the heat insulating property of the obtained structure for a long period of time. Therefore, for the purpose of improving the gas barrier properties of the resin, for example, Japanese Patent Application Laid-Open
JP-A-279083 and JP-A-63-233284 describe a metal laminate in which an aluminum foil is laminated on a thermoplastic resin film.

[0004] However, a vacuum heat insulating material comprising the above-mentioned metal laminate can maintain a high degree of vacuum for a long period of time, but a metal such as aluminum has a high thermal conductivity (for example, aluminum has a thermal conductivity of about 200 W). / MK
Whereas, the polypropylene resin is about 0.23 W /
m.K, about 0.02 W / m.K in air), a so-called heat bridge in which heat moves along the metal part occurred, resulting in a significant decrease in the initial heat insulation performance.

Although it has been considered to reduce the thickness of the metal layer for the purpose of suppressing the heat bridge, generally, when laminating a metal on a thermoplastic resin layer, a metal such as aluminum is vaporized once at a high temperature and the resin is laminated. To vapor-deposit on the surface of the layer or to separately create a metal foil by rolling or the like, and then laminate it to the resin layer, in these methods, when the thickness of the metal layer is reduced, many pinholes are generated, and the metal layer is provided. Despite this, the gas barrier properties decreased, resulting in a decrease in long-term heat insulation performance.

Further, for the same purpose, the above-mentioned metal deposition film or metal foil is provided intermittently so as to be discontinuous between the heat inflow side and the heat outflow side, and the heat conduction is cut off at the discontinuous portion. (Japanese Patent Laid-Open No. 5-2 / 1993)
However, when such a discontinuous portion is provided, gas permeation at the discontinuous portion increases, and as a result, the gas barrier property over time is greatly reduced, and it is difficult to achieve good heat insulating performance over a long period of time. there were.

[0007]

Means for Solving the Problems Then, the present inventors have studied for the purpose of developing a vacuum heat insulating material which is excellent in the initial heat insulating property and maintains the heat insulating property for a long period of time. As a result, the present invention has been accomplished.

That is, according to the present invention, an end of a laminate having at least one resin-containing layer (layer A) having a gas barrier property satisfying the following formula (1), a heat-sealing layer, and at least one metal foil is sealed. The present invention provides a vacuum heat insulating material having a hollow portion formed, wherein the metal foil is divided between a heat inflow side and a heat outflow side. W · λ · P <1 × 10 ⁻⁶ (1) (where W, λ, and P are the thickness (m) of the A layer, the thermal conductivity (W / m · K) of the A layer, and A Oxygen permeability at 23 ° C. and 50% RH at a layer thickness W (cc /
m2 · day · atm). Hereinafter, the present invention will be described in detail.

BEST MODE FOR CARRYING OUT THE INVENTION

The vacuum heat insulating material of the present invention is covered with a laminate having at least one resin-containing layer (layer A) having a gas barrier property satisfying the above formula (1), at least one heat-sealing layer, and at least one metal foil. It has a core material-containing hollow portion, and by evacuating the inside of the hollow portion, the heat insulating effect is further enhanced.

[0010] The metal foil has a side (heat inflow side) where heat flows into the vacuum heat insulating material from the outside due to heat conduction when the vacuum heat insulating material of the present invention is used, and heat from the vacuum heat insulating material to the outside. Must be separated from the outflow side (heat outflow side). If the metal foil is not divided, heat conduction increases from the heat inflow side to the heat outflow side, resulting in a poor heat insulation effect. The metal foil may be directly laminated on the gas barrier resin-containing layer, or may be laminated on another layer such as a base layer or a heat-sealing layer as described later.

Examples of the metal foil include an aluminum foil and a steel foil. From the viewpoint of gas barrier properties, the thickness of the metal foil is preferably 1 μ or more, more preferably 7 μ or more, and even more preferably 20 μ or more.

In the present invention, the layer A has a thickness W
(M), thermal conductivity λ (W / m · K), and thickness W
Oxygen permeability P at 23 ° C (cc / m^Two・ Day ・ atm)
1 × 10 ^-6Gas barrier layer that satisfies
Having the oxygen permeability as described
It is preferable from the viewpoint of the nature. The product is 1 × 10^-6Above
Is the heat insulation loss caused by the heat bridge?
Is not preferable because heat insulation deteriorates over time.
No. The product of W, λ and P is preferably small, and 2 × 1
0^-7Less than 1 × 10^-7Less than especially preferred
No. A layer contains, for example, an inorganic layered compound as described below.
In case, 1 × 10^-8Less than 1 × 1
0^-9Is preferably less than 1 × 10^-TenLess than preferred
No.

[0013] W, λ and P can be determined by a measuring method as described later. In addition, when the thickness of the layer A is extremely thin and the above values cannot be measured directly, the film is laminated on an appropriate film or the like, and the thickness of the laminate, the values of thermal conductivity and oxygen permeability, and the film before the gas barrier layer is laminated. The above value of the layer A may be determined from the difference from the respective values of the thickness, thermal conductivity, and oxygen permeability.

Each value of W, λ and P is not particularly limited as long as the product of these three satisfies the above range, but from the viewpoint of a heat bridge, W is preferably 10 mm or less.
It is more preferably 1 mm or less, particularly preferably 100 μm or less. From the viewpoint of the heat bridge, λ is 1
It is preferably at most 00 W / m · K, more preferably at most 10 W / m · K, particularly preferably at most 1 W / m · K.

P is 23% of the layer A when the thickness of the layer is the above W.
° C and 50% RH. From the viewpoint of maintaining heat insulation over a long period, P is 0.5 cc / m ² ···
It is preferably from day · atm, more preferably not more than ^{0.1cc / m 2 · day · atm} , and particularly preferably ^{0.01cc / m 2 · day · atm} .

Further, the layer A is a layer containing a resin, and may be a layer made of a resin, or a substance imparting a gas barrier property other than the resin as described later, such as a metal oxide or a metal hydroxide. May be a layer composed of a resin composition containing an inorganic substance. When the layer A is a layer composed of a resin composition, the resin preferably forms a continuous layer from the viewpoint of mechanical strength. Further, the resin of the layer A may be modified, and a crosslinking agent may be used.

The resin to be contained is preferably a resin having excellent gas barrier properties from the viewpoint of maintaining heat insulation.
Liquid crystal polymer such as liquid crystal polyester resin and hydrophobic resin such as aramid resin, weight percentage of hydrogen bonding group or ionic group per unit weight of resin is 20% to 60%
And a thermosetting resin such as an aromatic epoxy resin and a phenol resin satisfying the above ratio. More preferable examples of the high hydrogen bonding resin include those having a weight percentage of the hydrogen bonding group or the ionic group per unit weight of the high hydrogen bonding resin of 30% to 50%.

Examples of the hydrogen-bonding group of the high hydrogen-bonding resin include a hydroxyl group, an amino group, a thiol group, a carboxyl group, a sulfonic acid group, a phosphoric acid group, and the like. Group, a phosphate ion group, an ammonium group, a phosphonium group and the like.

Among the hydrogen bonding groups or ionic groups of the high hydrogen bonding resin, more preferred are a hydroxyl group, an amino group, a carboxyl group, a sulfonic acid group, a carboxylate group, a sulfonic acid ionic group and an ammonium group. Is mentioned.

Specific examples include, for example, polyvinyl alcohol, polyvinyl alcohol modified by crosslinking, etc., an ethylene-vinyl alcohol copolymer having a vinyl alcohol content of 41 mol% or more, and a vinyl alcohol content of 41 mol% or more. Ethylene-vinyl alcohol copolymer modified by crosslinking or the like, hydroxymethyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, amylose, amylopectin, pullulan, curdlan, xanthan, chitin, chitosan, cellulose,
Examples include polysaccharides such as pullulan and chitosan, polyacrylic acid, sodium polyacrylate, polybenzenesulfonic acid, sodium polybenzenesulfonate, polyethyleneimine, polyallylamine, its ammonium salt polyvinyl thiol, and polyglycerin.

The layer A may be, for example, a layer made of a gas-barrier resin as described above, or may have another layer having a gas-barrier property, for example, a unit crystal layer, to form a layered structure. An example is a layer composed of a resin composition composed of an inorganic layered compound and a resin such as polyvinyl alcohol. As the inorganic layered compound, the aspect ratio is preferably 50 or more and 5000 or less, more preferably 100 or more, from the viewpoint of gas barrier properties, economic efficiency, and availability of the obtained A layer.
Particularly preferred is 200 or more and 3000 or less.

As used herein, the term “aspect ratio” refers to a particle diameter (L) determined by a dynamic light scattering method in a solvent, once dispersed in the solvent, sufficiently swelled or cleaved, and then dried by drying the solvent. It is the ratio (L / a) of the collected layered compound to the unit thickness a determined by powder X-ray diffractometry or the like. As a solvent for measuring L and a, a solvent having a density smaller than the density of the inorganic layered compound is used, and for example, water is exemplified. For details of the aspect ratio, reference can be made to JP-A-7-251487 and JP-A-6-93133.

When the above-mentioned inorganic layered compound is used, L is preferably 5 μm or less, more preferably 3 μm or less, from the viewpoint of moldability.

Specific examples of the inorganic layered compound include graphite, a phosphate derivative type compound (zirconium phosphate compound), a chalcogenide [Group IV (Ti, Z
r, Hf), Group V (V, Nb, Ta) and Group VI (M
o, a dichalcogen product of W), represented by the formula MX _2. Here, X represents chalcogen (S, Se, Te)] or a viscous mineral. The composition ratio of the inorganic layered compound and the resin (weight ratio) is such that (inorganic layered compound / resin) is 5 / weight ratio from the viewpoint of heat insulating effect and moldability.
The range of 95 to 90/10 is preferable, and 5/95 to 50 /
More preferably, it is in the range of 50.

The resin used in the heat-sealing layer in the present invention is not particularly limited, but from the viewpoint of heat sealing strength and odor, for example, low-density or high-density polyethylene, ethylene-vinyl alcohol copolymer, ethylene-
Propylene copolymer, ethylene-butene copolymer, ethylene-hexene copolymer, ethylene-4-methyl-1-
Pentene copolymer, ethylene-octene copolymer, polypropylene, ethylene-vinyl acetate copolymer, ethylene-methyl methacrylate copolymer, ethylene-methyl acrylate copolymer, ethylene-acrylic acid copolymer, ionomer resin, etc. Polyolefin resins, polyamide resins such as nylon 6 and nylon 66, acrylonitrile-butadiene-styrene copolymer, acrylonitrile
Examples include styrene copolymers, acrylonitrile copolymers, and polyacrylates such as polymethyl methacrylate.

The vacuum heat insulating material of the present invention seals an end portion of the laminate having at least one layer A and at least one heat-sealing layer, thereby forming a hollow portion inside the bag, for example, as a bag. By evacuating the inside of the hollow portion, the heat insulating effect is further enhanced. There are at least two places to be sealed. For example, a two-way seal for sealing both ends of an opening of a blown film, a three-way seal for folding each overlapped end by folding one film into two, and two or more films. A bag-like material such as a four-sided seal that seals each end by overlapping can be exemplified, but is not particularly limited thereto. From the viewpoint of gas permeation from the seal portion, a two-way or three-way seal is preferable.

The seal portion has a thickness d of the heat-sealing layer.
(mm), when the width of the seal portion is H (mm), H / d> 2
0 is satisfied. When H / d is 20 or less, gas permeation from the seal portion increases. The larger the H / d, the more preferable from the viewpoint of gas barrier properties, more preferably 1 × 10 ² or more, and even more preferably 1 × 10 ³ or more. In the case where there is a possibility that the thickness of the heat-sealing layer of the seal portion may change before and after sealing such as heat sealing as described later, d is the thickness before sealing.

The respective values of H and d may be set so as to satisfy the above ratio, but from the viewpoint of gas barrier properties, d is set to 0.1.
It is preferably at most 2 mm, more preferably at most 0.05 mm, particularly preferably at most 0.04 mm. H is preferably 10 mm or more from the viewpoint of gas barrier properties,
mm or more is more preferable.

There is no particular limitation on the sealing method, and a commonly used sealing method such as heat fusion, pressure bonding, bonding with an adhesive, heating and pressure bonding called hot plate fusion or heat sealing, fusion by high frequency heating, and the like are used. Can be illustrated. Among these methods, heat sealing is preferred from the viewpoint of sealing strength and the like.

In the vacuum heat insulating material of the present invention, from the viewpoint of the heat insulating effect, it is preferable that the hollow portion formed by the above method has a so-called core material. The core material to be used is not particularly limited as long as it has a heat insulating property. For example, a core material having a thermal conductivity of less than 0.1 W / m · K as measured according to JIS R2618 is preferable. Specific examples of the core material include pearlite powder, silica powder,
Precipitated silica powder, glass wool, rock wool, open foamed resin foam and the like can be exemplified. 100 from the viewpoint of lightness
% Communicating urethane foam is preferred.

If necessary, a so-called getter agent having a gas-adsorbing property may be used in combination, or the getter agent may be used as a core material.

In the hollow portion of the vacuum heat insulating material of the present invention,
It may have a hollow structure. The shape of the hollow structure is not particularly limited, and includes a rectangular parallelepiped, a cube, a sphere, and the like.
In light of heat insulation, the thickness of the wall forming the hollow structure is preferably equal to or less than 10 mm, more preferably equal to or less than 5 mm,
Particularly preferred is 1 mm or less. The constituent material is not particularly limited, but is preferably made of resin from the viewpoint of the heat insulating property of the obtained vacuum heat insulator.

Examples of such a resin include low-density or high-density polyethylene, ethylene-propylene copolymer, ethylene-butene copolymer, ethylene-hexene copolymer, ethylene-octene copolymer, polypropylene, and ethylene-acetic acid. Polyolefin resins such as vinyl copolymer, ethylene-methyl methacrylate copolymer, ionomer resin, polyester resins such as polyethylene terephthalate, polybutylene terephthalate and polyethylene naphthalate, nylon-6, nylon-
6,6, meta-xylene diamine-adipic acid condensation polymer,
Amide resins such as polymethyl methacrylimide, acrylic resins such as polymethyl methacrylate, polystyrene, styrene-acrylonitrile copolymer, styrene-acrylonitrile-butadiene copolymer, styrene and acrylonitrile resins such as polyacrylonitrile, cellulose triacetate , Cellulose-based hydrophobic resins such as cellulose diacetate, halogen-containing resins such as polyvinyl chloride, polyvinylidene chloride, polyvinylidene fluoride, and Teflon; hydrogen-bonding resins such as polyvinyl alcohol, ethylene-vinyl alcohol copolymer, and cellulose derivatives , Liquid crystalline polymers such as liquid crystal polyester resin, polycarbonate resin, polysulfone resin, polyethersulfone resin, polyetheretherketone resin, polyphenyleneoxy Resins, polymethylene oxide resins,
Examples include engineering plastic resins such as aramid resins, urethane resins, phenol resins, and epoxy resins.

Further, the above-mentioned hollow structure may have a core material and / or a getter agent as described above therein.

The laminate in the present invention includes, for example, a laminate comprising a gas-barrier resin-containing layer, a metal foil and a heat-sealing layer, or a substrate layer, a gas-barrier resin-containing layer, a metal foil and a heat-sealing layer. Although a laminate can be exemplified, the layer configuration is not particularly limited.

As the vacuum heat insulating material of the present invention, for example, a laminate composed of the layer A, the heat-sealing layer and the metal foil is formed into a bag by heat sealing or the like, and a core material or a hollow structure or the like is provided in the bag. And the inside of the bag is evacuated and then sealed. From the viewpoint of strength, the resin laminate preferably has a base layer as described below, but there is no particular limitation on the layer configuration.

The pressure in the hollow portion after the evacuation is generally 1 Torr or less, preferably 0.1 Torr or less, and preferably 0.01 Ton from the viewpoint of heat insulation inside the vacuum heat insulating material.
rr or less is more preferable.

Further, in the vacuum heat insulating material of the present invention, in view of the shape of the vacuum heat insulating material and the oxygen permeability of the layer A, the area of the layer A covering the hollow portion is S (cm ² ), Void volume
(cm ³ ), it is preferable to satisfy the following expression (2). 1 × 10 ² <V / (P · S) <5 × 10 ³ (2) In the above formula (2), P has the same meaning as described above.

Here, in the present invention, the void volume in the hollow portion is the volume of the hollow portion after the inside of the hollow portion of the vacuum heat insulating material is evacuated, and the vacuum heat insulating material has a core material in the hollow portion. In this case, V is a value obtained by subtracting the true volume occupied by the core material from the volume of the hollow portion. The true volume occupied by the core material can be determined from the true specific gravity of the core material and the total weight of the core material used. When the above-described hollow structure is provided in the hollow portion of the vacuum heat insulating material, V is a value obtained by subtracting the entire volume of the wall forming the hollow structure from the volume of the hollow portion of the vacuum heat insulating material. . When the hollow structure has a core material or the like inside as described above, V is further described above from the value obtained by removing the total volume of the wall forming the hollow structure from the volume of the hollow portion of the vacuum heat insulating material. Thus, the value excluding the true volume occupied by the core material.

S is the area of the layer A covering the hollow portion of the vacuum heat insulating material, and is the area of the surface opposite to the surface facing the hollow portion. The area of the facing surface and the area of the opposite surface may be considered to be approximately the same. Therefore, S can be determined from the weight of layer A, its apparent specific gravity, and the thickness of layer A.

When a substrate layer is provided on the laminate of the present invention, the material used for the substrate layer is not particularly limited, but from the viewpoint of suppressing heat bridge, a material having as low a thermal conductivity as possible is preferable. From the viewpoint of properties, a resin is generally used. As the resin, for example, low-density or high-density polyethylene, ethylene-propylene copolymer, ethylene-butene copolymer, ethylene-hexene copolymer, ethylene-octene copolymer, polypropylene, ethylene-vinyl acetate copolymer Polyolefin resins such as ethylene-methyl methacrylate copolymer and ionomer resin; polyester resins such as polyethylene terephthalate, polybutylene terephthalate and polyethylene naphthalate; nylon-6, nylon-
6,6, meta-xylene diamine-adipic acid condensation polymer,
Amide resins such as polymethyl methacrylimide, acrylic resins such as polymethyl methacrylate, polystyrene, styrene-acrylonitrile copolymer, styrene-acrylonitrile-butadiene copolymer, styrene and acrylonitrile resins such as polyacrylonitrile, cellulose triacetate , Cellulose-based hydrophobic resins such as cellulose diacetate, halogen-containing resins such as polyvinyl chloride, polyvinylidene chloride, polyvinylidene fluoride, and Teflon; hydrogen-bonding resins such as polyvinyl alcohol, ethylene-vinyl alcohol copolymer, and cellulose derivatives , Polycarbonate resin, polysulfone resin, polyethersulfone resin, polyetheretherketone resin, polyphenylene oxide resin, polymethylene oxide resin, liquid crystal poly Such as engineering plastic resins such as ester resins. Among these resins, biaxially stretched polypropylene, polyethylene terephthalate, nylon, etc., biaxially stretched polypropylene coated with polyvinylidene chloride called K coat, polyethylene terephthalate, nylon, etc., aluminum-deposited film, alumina-deposited film, Various vapor-deposited films such as a vapor-deposited silica film, a liquid crystal polyester resin, an aramid resin and the like are preferable. As other base materials, metal foils such as aluminum foil and steel foil, inorganic foils and the like are used.

As a method for obtaining the above-mentioned laminate, a usual method such as a dry laminating method, a coating method and the like can be mentioned. For example, when the A layer is composed of the resin composition composed of the above-described inorganic layered compound and polyvinyl alcohol, after dissolving the polyvinyl alcohol in water, a dispersion in which the inorganic layered compound is dispersed in the solution is used as a coating liquid, What is necessary is just to coat on such a base material layer or a heat sealing layer. As a coating method, a direct gravure method, a reverse gravure method, a microgravure method,
Roll coating methods such as the present roll beat coating method and bottom feed three-reverse coating method, and methods such as a doctor knife method, a die coating method, a dip coating method, a bar coating method, and a coating method combining these methods.

The method of laminating the heat-sealing layer is not particularly limited, but a preferable example is a method of dry laminating the above-mentioned other layer or a layer containing a gas barrier resin. The metal foil can also be laminated by a method such as a dry lamination method.

Further, from the viewpoint of the adhesion strength between the layers of the obtained laminate, each layer may be subjected to a treatment such as a corona treatment, an ozone treatment, an electron beam treatment, or an anchor coating agent, if necessary.

The above-mentioned A layer, heat-sealing layer or base material layer may contain an ultraviolet absorbent, as long as the effects of the present invention are not impaired.
Various commercially available additives, such as a cross-linking agent, a colorant, and an antioxidant, which are usually added to a resin may be added.

From the viewpoint of heat insulation, a vacuum heat insulating material having a heat conductivity of 0.005 W / m · K or less when the pressure in the hollow portion covered with the laminate is 0.01 Torr is particularly preferable. As the vacuum heat insulating material, a detector for checking the degree of vacuum may be used as necessary.

The vacuum heat insulating material of the present invention has excellent heat insulating performance,
Refrigerated (10 ° C or less) refrigerator or refrigerator (0 ° C or less)
It can be used for refrigeration or freezing use as a heat insulating material for walls such as a refrigerator or a freezer compartment. Further, the vacuum heat insulating material of the present invention can be used for building materials used as heat insulating materials for ceilings, walls, floors and the like.

[0048]

The vacuum heat insulating material of the present invention has excellent initial heat insulating properties as compared with conventional ones and maintains heat insulating properties for a long period of time. Further, the vacuum heat insulating material of the present invention can be used for various applications that require heat insulation such as cold insulation, heat insulation (for example, refrigerators, freezers, cool cars, car ceilings, batteries, refrigerated or refrigerated boats, heated containers, refrigerated or refrigerated displays. Cases, portable coolers, cooking insulation cases, vending machines, solar water heaters, floor heating, underfloor, wall or inside walls, ceilings, attic rooms, etc., piping for hot water or cooling water, transfer of low-temperature fluid Pipes and other plant equipment, clothing, bedding, etc.).

[0049]

The present invention will be described below in detail with reference to examples, but the present invention is not limited to these examples.

The methods for measuring various physical properties are as described below. [Measurement of Thermal Conductivity] The thermal conductivity of the above-mentioned A layer was measured according to JIS R261.
8 was measured. When the A layer is a thin layer, the A layer (thickness Lt:
(m)) is measured together with the base material (λt), and the base material alone (thickness: LB: (m)) is separately measured (λB).
According to the following formula, thermal conductivity of layer A only (thickness LA: (m))
(λA) was calculated. Lt / λt = LA / λA + LB / λB The vacuum insulation material was measured according to JIS A1412.

[Oxygen Permeability Measurement] Oxygen permeability measurement device (O
X-TRAN100, manufactured by MOCON) at 23 ° C (5
Oxygen permeability was measured under the condition of 0% RH).

[Heat Sealing Conditions] Temperature 208 ° C., time 0.5 second, heat seal width 10 mm (heat sealer:
FUJI IMPULSE T230: FUJI IM
PULSE CO. (LTD) to form a bag.

[Thickness Measurement] The thickness of 0.5 μm or more was measured with a commercially available digital thickness gauge (contact type thickness gauge, trade name: ultra-high precision decimicro head MH-15M, manufactured by Nippon Kogaku Co., Ltd.). On the other hand, the thickness of less than 0.5 μm was determined by gravimetric analysis (the measured value of the weight of a film having a certain area was divided by the area and further divided by the specific gravity of the composition).

[Coating liquid 1] Dispersion pot (trade name: Despa MH)
-L, manufactured by Asada Tekko Co., Ltd.) and ion-exchanged water (0.7 μS / cm)
3551 g) and 200 g of polyvinyl alcohol (PVA117H; manufactured by Kuraray Co., Ltd., degree of saponification; 99.6%, degree of polymerization: 1700), and under low-speed stirring (1500 rpm)
m, the peripheral speed is 4.10 m / min) and the temperature is raised to 95 ° C.
Stir for hours to dissolve. Next, after lowering the temperature to 60 ° C. while stirring, natural montmorillonite (Kunipia G;
100 g of Kunimine Industries Co., Ltd.) as a powder was added, and after confirming that montmorillonite had substantially precipitated in the solution, high-speed stirring was performed (3100 rpm, peripheral speed 8.47 m / min).
Was carried out for 90 minutes to obtain a resin composition mixed solution (A) having a total solid content of 8 wt%. The mixed solution (A) was cast into a film, and X-ray analysis was performed. The bottom distance from the peak was 41.2 angstroms, indicating that the cleavage was sufficiently cleaved. The particle size of the natural montmorillonite (Kunipia F) determined by dynamic light scattering was 560 nm, the a value obtained from powder X-ray diffraction was 1.2156 nm, and the aspect ratio (Z) was 461.

Further, a silicone-based surfactant SH37
46 (manufactured by Dow Corning Toray Co., Ltd.) in an amount of 0.01 wt% based on the total amount of the solution was used as a coating solution 1 and used below.

[Example 1] Biaxial stretching OP having a thickness of 40 µm
P (FOK, Nimura Chemical Co., Ltd.) as a base film, and an anchor coat agent (Adcoat AD335) on the base film.
/ CAT10 = 15/1 (weight ratio): Toyo Morton Co., Ltd.) by gravure coating (test coater; Yasui Seiki Co., Ltd.): microgravure coating method, coating speed 6 m /
(Min., Drying temperature: 80 ° C.). The dry thickness of the anchor coat layer was 0.1 μm. Further, a coating liquid 1 is gravure coated on the layer (test coater; Yasui Seiki Co., Ltd.)
Manufacture: Microgravure coating method, coating speed 6 m / min, drying temperature 100 ° C.) to obtain an OPP film having a resin-containing layer (A layer) having gas barrier properties. When the thermal conductivity of the layer A was measured, it was 0.24 W / m · K, and the thickness after drying was 0.5 μm.

On the layer A of the obtained OPP film, a linear polyethylene (LL) surface corona-treated with a urethane-based adhesive (Eunoflex J3: manufactured by Sanyo Chemical Industries) was used.
DPE) (KF101, manufactured by Seki Fill Co., Ltd .: thickness 40μ)
m) was dry-laminated to obtain a laminate. Then, the oxygen permeability of the layer A of the laminate was measured (Table 1).

Reference Example 1 OPP Coated with Layer A
(250 mm x 250 mm) on layer A, 220 mm x 2
A 20 mm aluminum foil (20 μ) was dry-laminated at the center of the OPP with a urethane-based adhesive, and further LLDPE (250 mm × 250 mm) was dried on the aluminum foil. Using the obtained two laminates, the inner layer LLD
The three sides of the PE layer were heat-sealed to produce a bag of 250 mm × 250 mm. Then, as a core material in a bag,
The bag was filled with 100% open urethane foam (average cell diameter: 75 μm, manufactured by Kurabo Industries, Ltd.) that had been heated at 20 ° C. for 1 hour, and the inside of the bag was evacuated to 0.01 Torr. The other one is heat-sealed with a vacuum sealer (manufactured by NPC Corporation) (seal width 10 mm) to obtain a vacuum heat insulating material. The initial thermal conductivity of the obtained vacuum heat insulating material is extremely low, and the heat insulating property after aging is extremely low.

Comparative Example 1 Biaxially stretched OP having a thickness of 40 μm
P (FOK, manufactured by Nimura Chemical Co., Ltd.) as a base film, and an anchor coat agent (Adcoat AD3) on the base film.
35 / CAT10 = 15/1 (weight ratio): Toyo Morton Co., Ltd.) by gravure coating (test coater; Yasui Seiki Co., Ltd.): microgravure coating method, coating speed 6 m /
(Min., Drying temperature: 80 ° C.). The dry thickness of the anchor coat layer was 0.1 μm. Further, a polyvinylidene chloride emulsion (Crehalon DO833S, manufactured by Kureha Chemical Co., Ltd.) is gravure coated (test coater;
Yasui Seiki Co., Ltd .: Microgravure coating method, coating speed 6 m / min, drying temperature 100 ° C.) to obtain a biaxially stretched OPP film having a resin-containing layer. When the thermal conductivity of the resin-containing layer of the film was measured, it was 0.24 W / m · K, and the thickness after drying was 2.5 μm.

On the resin-containing layer of the obtained biaxially stretched OPP film, a urethane-based adhesive (Eunoflex J3:
Surface corona-treated linear polyethylene (LLDPE) (manufactured by Sanyo Chemical Industries, Ltd.) (manufactured by Seki-Fill Corporation: thickness 40 μm)
m) was dry-laminated to obtain a laminate. Then, the oxygen permeability was measured. (Table 1) [Comparative Reference Example 2] Further, a vacuum heat insulating material is obtained under the same conditions as in Example 1. It is inferior in the initial heat insulating property, and the heat insulating property is further remarkably reduced with time.

[0061]

[Table 1]

[0062]

[Table 2]

Example 1 A biaxially oriented polypropylene (OPP) film having a thickness of 20 μm (Pyrene P2102;
A surface corona-treated product of Toyobo Co., Ltd.) was used as a base layer, and an anchor coat agent (E) (Adcoat AD335 / CAT10 = 15/1 (weight ratio)) was formed on a protective base film.
Toyo Morton Co., Ltd.) was subjected to gravure coating (test coater; manufactured by Yasui Seiki Co., Ltd .: microgravure coating method, coating speed 3 m / min, drying temperature 80 ° C.). The dry thickness of the anchor coat layer was 0.15 μm. Gravure coating of coating liquid 1 (test coater; manufactured by Yasui Seiki Co., Ltd .: microgravure coating method, coating speed 6 m / min, drying temperature 1
(00 ° C.) and applied on the anchor coat layer. The dry thickness of the coating layer was 0.5 μm.

Then, a linear polyethylene (LLDPE) (Seki Filtration) subjected to a surface corona treatment using a urethane-based adhesive (Eunoflex J3: manufactured by Sanyo Chemical Co., Ltd.) was applied to the coating layer of the coating film obtained above. Manufactured by: 40μ thickness
m) was dry-laminated on the coating layer to obtain a laminate. [Reference Example 1] Using the two laminates obtained above, three sides of the LLDPE layer as the inner layer were thermally fused to 250 mm × 250.
mm bag-like material was produced. At this time, dry lamination was performed on the aluminum foil (20 μ) using a urethane-based adhesive (Eunoflex J3: manufactured by Sanyo Chemical Industries) at a portion where the upper and lower surfaces of the core material of the laminate contact. Next, 100% open-cell urethane (average cell diameter: 75 μm, manufactured by Kurabo Industries, Ltd.), which was heat-treated at 120 ° C. for 1 hour, was filled as a core material, and the inside of the bag was evacuated to 0.01 Torr. Then, the other one of the bag-like materials is heat-sealed with a vacuum sealer (manufactured by NPC Corporation) to obtain a vacuum heat insulating material. The initial thermal conductivity of the obtained vacuum heat insulating material is extremely low, and the heat insulating property after lapse of time is extremely low.

[Comparative Example 1] Aluminum foil (20μ) and a biaxially oriented polypropylene (OPP, 20μ)
Thickness, Pyren P2102, Toyobo Co., Ltd., was dry-laminated using a urethane-based adhesive (Eunoflex J3: manufactured by Sanyo Chemical Industries), and the surface of the aluminum foil side was corona-treated LLDPE (Sekifill Co., Ltd.) Made: thickness 40
μm) as an inner layer to obtain a laminate. [Comparative Reference Example 2] Further, a vacuum heat insulating material can be obtained under the same conditions as in Example 1, but the heat insulating property is significantly reduced with time.

Claims (12)

[Claims] An end portion of a laminate having at least one resin-containing layer (layer A) having a gas barrier property satisfying the following formula (1), a heat-sealing layer, and at least one metal foil is formed by sealing. A vacuum heat insulating material having a hollow portion, wherein the metal foil is divided between a heat inflow side and a heat outflow side. W · λ · P <1 × 10 ⁻⁶ (1) (where W, λ, and P are the thickness (m) of the A layer, the thermal conductivity (W / m · K) of the A layer, and A Oxygen permeability at 23 ° C. and 50% RH at a layer thickness W (cc /
m2 · day · atm). ) 2. The vacuum heat insulating material according to claim 1, wherein the metal foil is an aluminum foil or a steel foil. 3. The vacuum heat insulating material according to claim 1, further comprising a core material in the hollow portion. 4. A hollow structure having a hollow structure in the hollow portion.
2. The vacuum heat insulating material according to 2. 5. The vacuum heat insulating material according to claim 4, wherein a core material is provided in the hollow structure. 6. The vacuum heat insulating material according to claim 2, which satisfies the following expression (3). 1 × 10 ² <V / (P · S) <5 × 10 ³ (2) (where S is the area (cm ² ) of layer A covering the hollow portion, V
Is the void volume (cm ³ ) in the vacuum insulation material, and P represents the same meaning as described above. 7. The formula (1) according to claim 1, wherein W · λ · P
Vacuum insulation material having a value of less than 2 × 10 ⁻⁷ . 8. The vacuum heat insulating material according to claim 1, wherein the layer A contains an inorganic layered compound. 9. In the expression (1) in claim (1), W · λ ·
9. The vacuum heat insulating material according to claim 1, wherein the value of P is less than 2 × 10 ⁻⁸ . 10. The gas barrier resin-containing layer having a temperature of 23.degree.
Vacuum heat insulating material according to claims 1 to 9 oxygen permeability at RH% is equal to or less than ^{0.1cc / m 2 · day · atm} . 11. The vacuum heat insulating material according to claim 1, which is used for refrigeration or freezing. 12. The vacuum heat insulating material according to claim 1, which is used for building materials.