JP2013130289A - Vacuum heat-insulating structure and laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vacuum heat-insulating structure exhibiting excellent heat-insulating performance and free of the deterioration of the heat-insulating performance even through a long period of service, and to provide a laminate used therein.SOLUTION: The vacuum heat-insulating structure is formed so that a heat insulating material is packaged by the laminate [I] composed of the lamination of a gas-barrier type film (A), a polyester based film (B), and a protection film (C) which are laid one over another using a bonding agent in which the organic volatile component content of the laminate [I] measured by a gas chromatography standard testing method prescribed by the Soft Packing Sanitation Council is not larger than 0.8 mg/m. A laminate used in the vacuum heat-insulating structure is also provided.

Description

  The present invention relates to a vacuum heat insulating structure and a laminated body, and more particularly to a laminated body used for a vacuum heat insulating structure. More specifically, the present invention shows excellent heat insulating performance, and further deteriorates the heat insulating performance even when used for a long time. The present invention relates to a vacuum heat insulating structure and a laminate suitably used for the structure.

  Conventionally, heat insulating materials using polyurethane foam have been used as heat insulating materials for refrigerators and electric pots or heat insulating walls for houses, but in recent years, glass wool, silicon oxide have been used as excellent alternative materials. A vacuum heat insulating structure in which a heat insulating material such as foamed resin is used as a core material, which is sealed with a gas barrier laminate film and the inside is vacuumed, has begun to be used.

  Examples of the gas barrier laminate film include a multilayer film containing an aluminum foil, a multilayer film containing a polyvinyl alcohol-based resin film and an ethylene-vinyl alcohol-based resin film, and the like.

  For example, the vacuum heat insulating structure including a multilayer film containing an ethylene-vinyl alcohol copolymer resin film includes a core material and an outer bag envelope material that encloses the core material, and the outer bag is a vapor deposition Laminate films having layers, or a laminate film having a vapor deposition layer, and a laminate film having a metal foil are formed into a bag shape by heat welding, and the laminate film having the vapor deposition layer is a heat weld layer, A gas barrier layer and an outermost layer, wherein the gas barrier layer is an aluminum vapor-deposited on one side of a plastic film containing an ethylene-vinyl alcohol resin, and the aluminum vapor-deposited surface is on the heat-welded layer side A vacuum insulator (for example, refer to Patent Document 1) or a heat insulating material provided with a biaxially stretched polyvinyl alcohol film. It is a vacuum heat insulating structure obtained by hermetically packaging with a multilayer film containing rum, and as such a multilayer film, a biaxially stretched polyvinyl alcohol and a polyester film, a polyamide film, a polyolefin film, etc. on which a metal may be deposited may be used. A vacuum heat insulating structure (for example, see Patent Document 2) using a laminated multilayer film has been proposed.

JP-A-10-122477 JP 2005-237940 A

  However, in the techniques disclosed in Patent Documents 1 and 2, a multilayer film in which various films are laminated is used for the outer bag, and various films constituting the multilayer film or an adhesive for laminating them are used. It contains volatile components such as moisture and organic solvents that could not be removed during production or absorbed during storage, and these volatile components formed inside the structure over time after constituting the vacuum heat insulation structure As a result, the heat-insulating performance may be significantly deteriorated.

  In view of this, the present invention provides a vacuum heat insulating structure that has excellent heat insulating performance and does not deteriorate heat insulating performance even when used for a long period of time, and a laminate suitably used for the structure. It is intended.

  However, the present inventors have conducted extensive research in view of such circumstances, and as a result, a laminated body formed by laminating the gas barrier film (A), the polyester film (B), and the protective film (C) is insulated as an outer bag. In the hermetic packaging of functional materials, the adhesive used for laminating the gas barrier film (A), the polyester film (B), and the protective film (C), or organic volatile components contained in various films By using an extremely reduced laminate as an exterior bag, there is no release of organic volatile components even during long-term use, and a vacuum heat insulation structure that exhibits extremely high reliability in heat insulation performance over time can be obtained. As a result, the present invention has been completed.

That is, the gist of the present invention is that a heat insulating material is packaged by a laminate [I] obtained by laminating a gas barrier film (A), a polyester film (B), and a protective film (C) with an adhesive. A vacuum insulation structure having an organic volatile component amount of 0.8 mg / m ² or less measured by a gas chromatography standard test method defined by the Flexible Packaging Sanitation Council in the laminate [I]. It relates to a structure.

In the present invention, the gas barrier film (A), the polyester film (B), and the protective film (C) are laminated with an adhesive, and measured by a standard test method for gas chromatography defined by the Flexible Packaging Sanitation Council. A laminate having an organic volatile component content of 0.8 mg / m ² or less is also provided.

In the present invention, as described above, the amount of the organic volatile component is controlled to be smaller than that of the conventional exterior bag, and the conventional exterior bag is considered to adjust the amount of the organic volatile component. Although there is a case where special drying is not used, it is usually considered that moisture is absorbed on the surface of the outer bag or moisture of the constituent material before packaging the heat insulating material. In order to dry the water, a drying process is performed in a range of about 80 to 100 ° C. for about 30 minutes to 1 hour. In setting such drying conditions, an organic volatile component is used. The amount of the organic volatile component is 1.0 mg / m as the amount of the organic volatile component. ² It is surmised that this is over.

The vacuum heat insulating structure of the present invention comprises a gas barrier film (A), a polyester film (B), and a protective film (C) laminated with an adhesive, and a gas chromatography standard test defined by the Flexible Packaging Hygiene Council. A laminate [I] having an organic volatile component amount measured by the method of 0.8 mg / m ² or less is used as an outer bag, and the heat insulating material is hermetically packaged, and has excellent heat insulating performance, Furthermore, it has the effect that the heat insulation performance does not deteriorate even when used for a long time.

The present invention is described in detail below.
First, laminated body [I] used as the exterior bag for sealingly packaging a heat insulating material is demonstrated.

The laminate [I] of the present invention comprises a gas barrier film (A), a polyester film (B), and a protective film (C) laminated with an adhesive, and is a gas chromatography standard defined by the Flexible Packaging Hygiene Council. The amount of organic volatile components measured by the test method is 0.8 mg / m ² or less.

The gas barrier film (A) used in the present invention is a film having gas barrier properties, and may be any known film used as an exterior bag of a vacuum heat insulating structure. Usually, among such gas barrier films, 23 ° C. It is preferable to use a film having an oxygen transmission rate of 1 ml / (m ² · day · atm) or less when measured according to the method described in JIS K 7126 (isobaric method) under the condition of −50% RH. Is preferably 0.1 ml / (m ² · day · atm) or less. Specifically, a vinyl alcohol film is particularly preferable in terms of obtaining high gas barrier properties.

  Such a vinyl alcohol film is formed from a vinyl alcohol resin, and the vinyl alcohol resin only needs to have a vinyl alcohol unit obtained by saponifying a vinyl ester unit, preferably The average saponification degree is 90 mol% or more, particularly preferably 95 mol% or more, and more preferably 97 mol% or more.

Examples of the vinyl alcohol resin include a polyvinyl alcohol resin (hereinafter sometimes abbreviated as PVA resin) and an ethylene-vinyl alcohol resin (hereinafter abbreviated as EVOH resin). Among them, a PVA resin is particularly preferable.

As the vinyl alcohol film, a film made of a known PVA resin or EVOH resin can be used, and these resins will be described below.
First, the PVA resin will be described.

  Examples of the PVA-based resin include PVA obtained by homopolymerizing vinyl acetate and saponification thereof, and modified PVA. Examples of such modified PVA include copolymer-modified products and post-modified products. PVA is produced by homopolymerizing vinyl acetate and further saponifying it. Further, the modified PVA is produced by copolymerizing an unsaturated monomer copolymerizable with vinyl acetate and vinyl acetate and then saponifying, and the amount of modification is within a range not impairing the effect of the present invention. Yes, usually less than 10 mol%.

  Examples of the unsaturated monomer copolymerizable with vinyl acetate include olefins such as ethylene, propylene, isobutylene, α-octene, α-dodecene, α-octadecene, 3-buten-1-ol, and 4-pentene. Derivatives such as hydroxy group-containing α-olefins such as -1-ol and 5-hexen-1-ol and acylated products thereof, acrylic acid, methacrylic acid, crotonic acid, maleic acid, maleic anhydride, itaconic acid, undecylenic acid Unsaturated acids such as salts, monoesters or dialkyl esters, nitriles such as acrylonitrile and methacrylonitrile, amides such as diacetone acrylamide, acrylamide and methacrylamide, ethylene sulfonic acid, allyl sulfonic acid, methallyl sulfonic acid Olefin sulfonic acids such as Or salts thereof, alkyl vinyl ethers, dimethylallyl vinyl ketone, N-vinyl pyrrolidone, vinyl chloride, vinyl ethylene carbonate, 2,2-dialkyl-4-vinyl-1,3-dioxolane, glycerol monoallyl ether, 3,4 -Vinyl compounds such as diacetoxy-1-butene, substituted vinyl acetates such as isopropenyl acetate and 1-methoxyvinyl acetate, vinylidene chloride, 1,4-diacetoxy-2-butene, and vinylene carbonate.

  Further, as the PVA resin, a PVA resin having a 1,2-diol bond in the side chain can also be used, and the PVA resin having a 1,2-diol bond in the side chain is, for example, (a) acetic acid A method of saponifying a copolymer of vinyl and 3,4-diacetoxy-1-butene, (a) a method of saponifying and decarboxylating a copolymer of vinyl acetate and vinyl ethylene carbonate, and (c) vinyl acetate. Of saponifying and deketalizing a copolymer of 2,2-dialkyl-4-vinyl-1,3-dioxolane, and (d) saponifying a copolymer of vinyl acetate and glycerol monoallyl ether. Obtained by a method, etc.

  Furthermore, as modified PVA, it can also manufacture by post-modifying PVA. Examples of such post-modification methods include a method of converting PVA into acetoacetate ester, acetalization, urethanization, etherification, grafting, phosphoric esterification, and oxyalkylene.

  In the present invention, the polymerization degree of the PVA resin is preferably 1100 or more and the average saponification degree is 90 mol% or more. The more preferable range of the polymerization degree is 1100 to 4000, and the particularly preferable range is 1200 to 2600. The more preferable range of the average saponification degree is 95 to 100 mol%, and the particularly preferable range is 99 to 100 mol%. If the degree of polymerization is too low, the mechanical strength of the film tends to decrease. If the degree of polymerization is too high, the processability during film formation and stretching tends to decrease. If the average saponification degree is too low, the water resistance is lowered, and the change of the gas barrier property due to humidity tends to be remarkable. Therefore, it is preferable to select a relatively high saponification degree. In addition, the said polymerization degree and average saponification degree are measured according to JISK6726.

Moreover, as a viscosity of the 4 weight% aqueous solution of the said PVA-type resin, 2.5-100 mPa * s (20 degreeC) is preferable, Furthermore, 2.5-70 mPa * s (20 degreeC), Especially 2.5- 60 mPa · s (20 ° C.) is preferable. If the viscosity is too low, mechanical properties such as film strength tend to decrease, and if it is too high, film-forming properties on the film tend to decrease.
The viscosity is measured according to JIS K6726.

  These PVA resins can be used alone or in combination of two or more.

Next, the EVOH resin will be described.
EVOH resin is a thermoplastic resin that is obtained by copolymerizing ethylene and vinyl ester and then saponifying, and does not dissolve in water (including hot water). Polymerization of ethylene and vinyl ester monomer is The polymerization can be carried out by any known polymerization method such as solution polymerization, suspension polymerization, emulsion polymerization and the like. A typical example of such vinyl ester is vinyl acetate, but other fatty acid vinyl esters (such as vinyl propionate and vinyl pivalate) can also be used. Further, the EVOH-based resin may contain 0.0002 to 0.2 mol% of a vinyl silane compound as a copolymerization component in order to improve stability during heat melting. Here, examples of the vinylsilane compound include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltri (β-methoxy-ethoxy) silane, and γ-methacryloxypropylmethoxysilane. Of these, vinyltrimethoxysilane and vinyltriethoxysilane are preferably used. Further, other copolymerizable monomers such as propylene, butylene; unsaturated (meth) acrylic acid, methyl (meth) acrylate, ethyl (meth) acrylate, etc., as long as the object of the present invention is not inhibited. Carboxylic acid or an ester thereof; vinyl pyrrolidone such as N-vinyl pyrrolidone can be copolymerized.

The ethylene content of the EVOH-based resin is 20 to 60 mol%, but from the viewpoint of obtaining good stretchability, the ethylene content is particularly preferably 25 mol% or more, and more preferably 30 mol% or more. From the viewpoint of gas barrier properties, the ethylene content is particularly preferably 55 mol% or less, and more preferably 50 mol% or less. If the ethylene content is too small, the melt moldability tends to decrease, and if it is too large, the gas barrier property tends to decrease.
In addition, the ethylene content of the EVOH resin can be obtained by a nuclear magnetic resonance (NMR) method.

Further, the saponification degree of such EVOH-based resin is preferably 90% or more, more preferably 95% or more, and further preferably 99% or more. If the degree of saponification is too low, the gas barrier property under high humidity tends to decrease.
Here, when the EVOH-based resin is composed of a blend of two or more types of EVOH-based resins having different saponification degrees, the average value calculated from the blending weight ratio is defined as the saponification degree.

  Furthermore, a boron compound can be blended with the EVOH resin in order to improve the stability at the time of heating and melting within a range that does not obstruct the object of the present invention. Examples of the boron compound include boric acids, boric acid esters, borates, and borohydrides. Specifically, examples of boric acids include orthoboric acid, metaboric acid, and tetraboric acid. Examples of boric acid esters include triethyl borate and trimethyl borate. Examples of boric acid salts include those described above. Examples include alkali metal salts, alkaline earth metal salts, and borax of various boric acids. Among these compounds, orthoboric acid (hereinafter sometimes simply referred to as boric acid) is preferable.

  When a boron compound is blended with an EVOH-based resin, the content of the boron compound is preferably 20 to 2000 ppm, more preferably 50 to 1000 ppm in terms of boron element. By blending the boron compound within this range, it is possible to obtain an EVOH-based resin in which torque fluctuation during heating and melting is suppressed. If the content of the boron compound is too small, the effect of addition is small, and if it is too large, gelation tends to occur and the moldability may be poor.

  A suitable melt flow rate (MFR) (230 ° C., under a load of 2160 g) of such EVOH-based resin is usually 1 to 50 g / 10 minutes, more preferably 3 to 40 g / 10 minutes, and further preferably 5 to 5 g. 30 g / 10 minutes. These EVOH resins can be used alone or in a mixture of two or more.

  In the present invention, the vinyl alcohol resin is used to form a film. However, such a film forming method may be a known one. For example, a vinyl alcohol resin solution is allowed to flow on a metal surface such as a drum or an endless belt. The film is formed by a cast molding method in which a film is formed by stretching, or a melt molding method in which melt extrusion is performed by an extruder.

  Such a vinyl alcohol film may be used as a non-stretched film, but is usually preferably used as a uniaxially stretched film or a biaxially stretched film, and is particularly preferably used as a biaxially stretched film from the viewpoint of gas barrier properties. The stretching ratio in the flow direction (MD direction) of the uniaxially or biaxially stretched film is preferably 2.5 to 5 times.

  Such a stretching treatment method can be performed according to a known method such as a uniaxial stretching method that is usually performed, simultaneous biaxial stretching, and sequential biaxial stretching.

  In the present invention, among such biaxially stretched vinyl alcohol films, a biaxially stretched PVA film and a biaxially stretched EVOH film are preferably used, and a biaxially stretched PVA film is particularly preferably used. Hereinafter, the specific manufacturing method of these biaxially stretched films is demonstrated.

  First, the biaxially stretched PVA resin film will be described.

  A PVA-based film (PVA-based film before stretching) is formed using the PVA-based resin. Usually, a PVA-based resin concentration is 5 to 70% by weight, preferably as a stock solution for film formation. A composition of 10 to 60% by weight of PVA resin-water is prepared.

  Such PVA-based resin-water compositions include plasticizers of polyhydric alcohols such as ethylene glycol, glycerin, polyethylene glycol, diethylene glycol, and triethylene glycol, phenolic, amine-based, and the like as long as the effects of the present invention are not impaired. Add appropriate additives such as antioxidants, stabilizers such as phosphate esters, colorants, fragrances, extenders, defoamers, release agents, UV absorbers, inorganic powders, surfactants, etc. There is no problem. Moreover, you may mix other water-soluble resins other than PVA-type resin, such as starch, carboxymethylcellulose, methylcellulose, and hydroxymethylcellulose.

  The method for forming the PVA film is not particularly limited, but after the PVA resin-water composition is supplied to an extruder and melt-kneaded, the film is extruded by the T-die method or the inflation method and dried. Is preferred.

  The melt kneading temperature in the extruder in such a method is preferably 50 to 170 ° C, particularly 55 to 160 ° C. If the temperature is too low, the film skin will be defective, and if it is too high, the foaming phenomenon tends to occur. Moreover, about the drying of the film after film forming, it is preferable to carry out at 70-120 degreeC, and also it is preferable to carry out at 80-100 degreeC.

The biaxially stretched PVA film preferably used in the present invention is obtained by further biaxially stretching the PVA film obtained above.
For such biaxial stretching, the stretching ratio in the machine flow direction (MD direction) is preferably 2.5 to 5 times, and the stretching ratio in the width direction (TD direction) is preferably 2 to 4.5 times, particularly preferably. The MD has a stretching ratio of 3 to 5 times, and the TD direction has a stretching ratio of 2.5 to 4.5 times. If the draw ratio in the MD direction is too low, it is difficult to improve physical properties due to stretching and the heat resistance tends to be impaired. If it is too high, the film tends to tear in the MD direction. Further, if the stretching ratio in the TD direction is too low, it is difficult to obtain physical properties by stretching, and the heat resistance tends to be impaired. If it is too high, breakage during stretching tends to occur frequently when the film is industrially produced. is there.

  In performing such sequential biaxial stretching or simultaneous biaxial stretching, it is preferable to adjust the water content of the PVA-based film to 5 to 30% by weight, particularly 20 to 30% by weight. The moisture content can be adjusted by a method in which the PVA film before drying is subsequently dried, a method in which a PVA film having a moisture content of less than 5% by weight is immersed in water, or is conditioned. Even if the moisture content is too low or too high, there is a tendency that the stretching ratio in the MD direction and the TD direction cannot be increased in the stretching process.

  Furthermore, after performing biaxial stretching, it is preferable to perform heat setting, and the temperature of such heat setting is preferably selected to be lower than the melting point of the PVA-based resin, particularly 140 to 250 ° C. Is preferred. When the heat setting temperature is lower than the melting point by 80 ° C. or more, the dimensional stability tends to be poor and the shrinkage rate tends to be large. The heat setting time is preferably 1 to 30 seconds, and more preferably 5 to 10 seconds.

  In addition, for the purpose of further reducing the heat deformability, it is possible to subject the biaxially stretched PVA-based film to contact with an aqueous solution and to drying as necessary. In contact with the aqueous solution, an aqueous solution of usually 5 to 60 ° C., preferably 10 to 50 ° C. is used, and the contact time with the aqueous solution is appropriately selected according to the temperature of the aqueous solution, but industrially 10 to Preferably it is 60 seconds.

  Examples of the contact method with an aqueous solution include immersion in an aqueous solution, spraying of an aqueous solution, application of an aqueous solution, steam treatment, and the like, and these can be used in combination. After contact with the aqueous solution, industrially, it is preferable to remove the adhering water on the surface in a non-contact manner with an air shower or the like, and then to remove the moisture in a contact manner with a nip roll or the like. Moreover, as a kind of dryer, the method of using a non-contact dryer etc. etc. etc. which are directly contacted with a metal roll, a ceramic roll etc., for example, are mentioned, for example.

When the obtained biaxially stretched PVA-based film is wound up again after the contact with the aqueous solution and drying, the water content of the film is usually 3% by weight or less, preferably 0.1 to 2% by weight. % Is desired. If the amount of moisture is too large, the films tend to adhere to each other in the film roll, and there is a risk of problems such as damage to the film when unwinding for processing again.
Thus, a biaxially stretched PVA film suitably used in the present invention is obtained.

Next, the biaxially stretched EVOH film will be described.
An EVOH film (an EVOH film before stretching) is formed using the EVOH resin.

  Such EVOH-based resin includes an antioxidant, a colorant, an ultraviolet absorber, a slip agent, an antistatic agent, a plasticizer, a crosslinking agent such as boric acid, an inorganic filler, and the like within a range that does not interfere with the object of the present invention. You may mix | blend various resins, such as various additives, such as an inorganic desiccant, polyamide, polyolefin, and a super absorbent polymer.

When forming an EVOH film using the EVOH resin, melt molding is mainly used. The melt molding method will be described below.
The conditions at the time of melt molding are not particularly limited, but are usually formed by extrusion using a non-vented, screw-type extruder at a melting temperature of 190 to 250 ° C. Usually, a screw having a compression ratio of 2.0 to 4.5 is used to form a film using a T die or a round die.

  Thus, an EVOH film can be obtained, and the film can be further biaxially stretched, preferably sequentially biaxially stretched to obtain a biaxially stretched EVOH film.

  The area ratio of such biaxial stretching is preferably 3 times or more, more preferably 6 times or more, and particularly preferably 9 times or more from the viewpoint of gas barrier properties and mechanical strength. As a stretching method, a known stretching method such as a uniaxial or biaxial stretching method such as a double bubble method, a tenter method, a roll method, etc. can be adopted. In the case of biaxial stretching, either simultaneous stretching or sequential stretching can be used. This method can also be adopted.

  Moreover, easy continuous stretching is possible by pre-hydrating the original film before stretching, and the moisture content of the original film before stretching is preferably 2 to 30% by weight, particularly 5 to 30% by weight. % Is preferable, and further 10 to 30% by weight is preferable. If the moisture content is too low, stretch spots are likely to remain, and particularly when stretched with a tenter, the stretch ratio in the portion close to the grip becomes high, so that tearing near the grip may easily occur. On the other hand, if the moisture content is too high, the elastic modulus of the stretched portion is low, the difference from the unstretched portion is not sufficient, and stretched spots may remain easily.

  The stretching temperature varies somewhat depending on the moisture content of the original film before stretching, but a range of 50 to 130 ° C. is generally applicable. Particularly in simultaneous biaxial stretching, a biaxially stretched EVOH-based film with little thickness unevenness is easily obtained in the range of 70 to 100 ° C., and in sequential biaxial stretching, 70 to 100 ° C. in longitudinal stretching with a roll. By performing the stretching in the width direction with a tenter in the temperature range of 80 to 120 ° C., a biaxially stretched EVOH-based film with few thickness spots is easily obtained.

Further, further important factors relating to the production of the biaxially stretched EVOH film include the heat treatment after stretching, and the density and moisture content of the biaxially stretched EVOH film obtained as a result of the heat treatment. The heat treatment is preferably performed at a temperature 5 to 40 ° C. lower than the melting point of EVOH for 5 to 20 seconds. If the heat treatment temperature is too low, the heat treatment is insufficient, so that heat resistance sufficient to withstand the vapor deposition process and sufficient gas barrier properties may not be obtained. On the other hand, if the heat treatment temperature is too high, the stretching effect may be partially reduced.
Thus, a biaxially stretched EVOH film suitably used in the present invention is obtained.

  In the present invention, it is preferable to use, as the gas barrier film (A), a vinyl alcohol film on which the metal or metal oxide is vapor-deposited on the vinyl alcohol film. .

  As such a metal or metal oxide, for example, a metal such as aluminum, gold, silver, copper, nickel, cobalt, chromium, tin, or an oxide of such a metal can be used. Among these, aluminum, gold, silver, and tin are preferably used, and aluminum is particularly preferably used from the viewpoint of cost.

The thickness of the vapor deposition layer formed by vapor deposition of such metal or metal oxide is preferably 200 to 1000 mm, particularly preferably 300 to 800 mm. If the thickness of the deposited layer is too thin, thermal radiation characteristics tend to be difficult to obtain, and if too thick, the deposition time for obtaining the thickness is too long, and the thermal influence during deposition tends to be too great. , Industrially unfavorable.
Moreover, the said vapor deposition layer may be obtained by one vapor deposition process, and may be obtained by repeating vapor deposition process in multiple times.

  As a deposition method of such metal or metal oxide, for example, a general vacuum deposition method such as a sputtering method, an ion plating method, a resistance heating deposition method, a high-frequency induction heating deposition method, or an electron beam heating deposition method is used. it can.

  In addition, it is possible to pre-treat the surface of the film before performing the vapor deposition treatment on the vinyl alcohol film, and as such pre-treatment, for example, a method for promoting activation of the substrate itself such as corona treatment And a method of forming a thin film layer with a coating agent that uses polyethylene or polyether as a main component and uses a urethane-based curing agent.

  Thus, although the gas barrier film (A) used in the present invention is obtained, the thickness thereof is usually 5 to 100 μm, preferably 8 to 50 μm, particularly preferably 8 to 30 μm. Is advantageous. The film thickness when using the biaxially stretched PVA film is preferably 5 to 50 μm, particularly preferably 8 to 30 μm, and the film thickness when using the biaxially stretched EVOH film is preferably 5 It is -50 micrometers, Most preferably, it is 10-40 micrometers. If this thickness is too thick, the cost increases industrially and the multilayer film formed by lamination becomes too hard, and the shape followability at the time of vacuum packaging is lowered, and in some cases, there is a possibility that a part may be damaged. If the film is too thin, defects may occur in a part of the film or an extreme thinning site may occur, making it difficult to obtain necessary barrier properties.

  The polyester-based film (B) used in the present invention may be a known polyester-based film used for producing a vacuum heat insulating structure exterior bag, and is made of a polyester-based resin. The polyester-based resin is an acid component. And a glycol component.

  Examples of the acid component include terephthalic acid, oxalic acid, isophthalic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid, 5-sodium sulfoisophthalic acid, succinic acid, adipic acid, azelaic acid, sebacic acid, and dodecanedioic acid. , Dimer acid, maleic anhydride, maleic acid, fumaric acid, itaconic acid, citraconic acid, mesaconic acid, dicarboxylic acid such as cyclohexanedicarboxylic acid, 4-hydroxybenzoic acid, ε-caprolactone, oxycarboxylic acid such as lactic acid, etc. It is done.

  Examples of the glycol component include ethylene glycol, 1,3-propanediol, 1,4-butanediol, neopentyl glycol, 1,6-hexanediol, cyclohexanedimethanol, triethylene glycol, polyethylene glycol, polypropylene glycol, And glycols such as polytetramethylene glycol.

  By copolymerizing the above acid (component) and glycol (component), the polyester resin used in the present invention is obtained. The combination of both components is not particularly limited, and those copolymerized in any combination can be used. Among them, as the polyester, polyethylene terephthalate, polyethylene naphthalate, polycyclohexylene dimethylene terephthalate is preferably used. Furthermore, polyethylene terephthalate is particularly preferably used.

  The polyester film (B) used in the present invention may be a mixture of two or more of the above polyester resins, or may be a mixture of other thermoplastic resins.

  In addition, the polyester film (B) is composed of an ultraviolet absorber, an antioxidant, an antistatic agent, a surfactant, a pigment, a fluorescent brightening agent, and other inorganic particles such as silica, calcium carbonate, and titanium oxide, and acrylic acid. In addition, organic particles containing styrene or the like as a constituent component may be appropriately contained as necessary.

  A known manufacturing method can be used for the manufacturing method of the polyester film (B). For example, an oligomer is obtained by a transesterification method from dimethyl terephthalate and ethylene glycol or a direct esterification method from terephthalic acid and ethylene glycol, and then melt polymerization or further solid phase polymerization, etc. be able to.

  The polyester film (B) thus obtained may be used as it is, but it is also preferably used as a uniaxially stretched or biaxially stretched polyester film after being subjected to a stretching treatment, particularly in terms of water vapor barrier properties and gas barrier properties. Therefore, a biaxially stretched polyester film is preferably used.

  As a method for producing such a biaxially stretched polyester film, a publicly known method can be used, and examples thereof include the following methods.

  First, a polyester chip is put into an extruder, heated and melted, extruded from a die orifice of a T die into a sheet shape, closely attached to a cooling drum by an electrostatic application casting method or the like, cooled, and an unstretched sheet is To manufacture. Subsequently, the film is stretched at a temperature of 85 to 140 ° C. at a magnification of 2.5 to 5.0 times in the vertical and horizontal directions, and further heat treated at a temperature of 200 to 245 ° C. to obtain a biaxially stretched film. If the stretching temperature is too low, there is a tendency that a homogeneous stretched film cannot be obtained. If it is too high, crystallization of the polyester is promoted and transparency tends to be lowered. When the draw ratio is too low, the strength of the obtained stretched film is lowered, and when the draw ratio is too large, stretching tends to be difficult. Moreover, when the heat treatment temperature is too low, the thermal shrinkage rate of the obtained stretched film tends to increase and the dimensional stability tends to decrease. When the heat treatment temperature is too high, the film may be melted.

  The biaxial stretching method may be either a tenter simultaneous biaxial stretching method or a sequential biaxial stretching method using a roll and a tenter. Moreover, you may manufacture a biaxially stretched film with a tubular method. Further, the biaxially stretched film can be subjected to surface treatment by corona discharge treatment, surface hardening treatment, plating treatment, coloring treatment, or various coating treatments.

  The thickness of the polyester film (B) is usually 5 to 200 μm, particularly preferably 10 to 100 μm. If the thickness is too thin, tearing or the like tends to occur at the time of processing. On the other hand, if the thickness is too large, not only the workability is lowered but also the economy tends to be uneconomical.

  Furthermore, the polyester film (B) used in the present invention has a metal or metal oxide formed by vapor-depositing a metal or metal oxide on the polyester film for the purpose of improving water vapor barrier properties and gas barrier properties. A vapor-deposited polyester film is preferred. As the metal or metal oxide used for the vapor deposition layer, for example, a metal or metal oxide such as aluminum, gold, silver, copper, nickel, cobalt, chromium, or tin can be used. Among these, aluminum, gold, silver, and tin are preferably used, and aluminum is particularly preferably used from the viewpoint of cost. The thickness of the deposited layer is usually 50 to 1000 mm, particularly 200 to 1000 mm. The method for depositing the polyester film may be performed in accordance with the method for depositing the vinyl alcohol film described above.

  Thus, the polyester film (B) used in the present invention is obtained, and the thickness thereof is usually 5 to 80 μm, preferably 8 to 40 μm, particularly preferably 10 to 30 μm, which is obtained by cost and lamination. It is preferable at the point which gives moderate softness | flexibility to the multilayer film obtained. If the thickness is too thick, the multilayer film obtained by lamination becomes too hard and the shape following property at the time of vacuum packaging becomes low, and there is a tendency to cause breakage in some cases, and if it is too thin, a part of the polyester film layer is lost. The necessary barrier properties tend to be lost.

  As a protective film (C) used by this invention, it is a film used in order to protect the laminated body containing a gas-barrier film (A) and a polyester-type film (B), for example, a polyester-type film, a polyamide-type A film, a polyolefin-type film, a polyurethane-type film etc. are mentioned. Among them, it is preferable to use a polyolefin film, preferably a polypropylene film, a polyvinyl chloride film, a polyvinylidene chloride film, or a fluorine film in order to reduce water vapor reaching the main barrier layer.

  A general-purpose polyolefin film can be used as the polyolefin film.

  For example, homopolymers such as polypropylene, polybutene-1, high-density polyethylene, medium-density polyethylene, and low-density polyethylene may be mentioned, as well as ethylene, butene-1, pentene-1, 4-methylpentene-1 having propylene as a main component. , Hexene-1, octene-1, 5-ethylidene-2-norbornene, 5-methylene-2-norbornene, 1,4-hexadiene, copolymers with styrene, and also grafted with carboxylic acid such as maleic anhydride A modified one, a copolymer of ethylene, propylene, butene-2, isobutylene, butadiene, pentene-1, 4-methylpentene-1, hexene-1, octene-1 and the like mainly containing butene-1; Furthermore, ethylene is the main component that is graft-modified with carboxylic acid such as maleic anhydride. Propylene, butene-1, 4-methylpentene-1, 1-hexene, 1-octene, 5-ethylidene-2-norbornene, 5-methylene-2-norbornene, styrene, vinyl acetate, methyl acrylate, acrylic acid Examples thereof include copolymers with ethyl, acrylic acid, methyl methacrylate, ethyl methacrylate, methacrylic acid, glycidyl methacrylate, and the like and graft-modified with carboxylic acids such as maleic anhydride. Among these, it is particularly preferable to use polypropylene from the viewpoint of moisture resistance and industrial productivity.

  Further, it is also preferable to perform a stretching treatment and use a uniaxially stretched or biaxially stretched polyolefin film, and in particular, a biaxially stretched polyolefin film is preferably used from the viewpoint of obtaining a higher gas barrier property with a thinner film.

  The thickness of the protective film (C) is usually 5 to 200 μm, particularly preferably 10 to 100 μm. If the film thickness is too thin, the filling property of the heat insulating material that becomes the core material of the vacuum heat insulating structure obtained is lowered, and if it is too thick, not only the workability is lowered but also economically disadvantageous.

Further, the protective film (C) preferably has an initial elastic modulus of 1 to 100 GPa, more preferably 0.5 to 50 GPa, and a water vapor transmission rate of 10 g / m ² / day or less, further 8 g / m ^2. / Day or less is preferable.
The initial elastic modulus is 23 ° C. × 60% r.D. measured in accordance with JIS K 7127. h. The water vapor transmission rate is a value at 23 ° C. × Δ90% RH measured according to JIS Z 0208.

The laminate [I] of the present invention is formed by laminating a gas barrier film (A), a polyester film (B), and a protective film (C) with an adhesive, and The amount of organic volatile components measured by the standard gas chromatography standard test method is 0.8 mg / m ² or less.

  A preferred layer configuration of the laminate [I] of the present invention is a layer configuration of gas barrier film (A) / polyester film (B) / protective film (C). As will be described later, in the case of manufacturing a vacuum heat insulating structure by sealing and packaging a heat insulating material with such a laminate [I], it is preferable that the gas barrier film (A) is on the inner side (heat insulating material side). This is preferable in terms of reducing the influence of water vapor from the outside on the film.

  Further, if necessary, it is also preferable to provide a coating layer on the gas barrier film (A) or the polyester film (B) in terms of obtaining a high barrier property in a thinner layer structure. The coating layer may be provided on either side of each film, and when it has a deposited layer on which a metal or metal oxide is deposited, the surface on the deposited layer side and the surface opposite to the deposited layer Either may be provided.

  In the case of applying a paint layer, any paint can be selected, but from the viewpoint of thermal radiation characteristics, the reflectance of the paint layer is preferably 60% or more, particularly 80% or more, White, white silver, silver and the like are preferably used. The method for forming the paint layer is not particularly limited, but a method of applying a commercially available paint by a printing method such as gravure printing, offset printing or flexographic printing is practical. The binder of the gas barrier film (A) or polyester film (B) and the coating layer is not particularly limited, but it is preferable from the viewpoint of adhesion that a urethane curing agent is blended in the binder.

  In addition, when a paint layer is applied to the surface of the gas barrier film (A) or the polyester film (B), the surface of each film on which a metal or a metal oxide is deposited for the purpose of improving the adhesion to the paint layer. Pre-processing can also be performed. Examples of the pretreatment include a method of promoting activation of the substrate itself such as corona treatment, and a method of forming a thin film layer with a coating agent using polyethylene or polyether as a main ingredient and a urethane-based curing agent.

  In addition, when it has a vapor deposition layer by which the metal or metal oxide was vapor-deposited here, said surface is the surface on the vapor deposition layer side by which the metal or metal oxide was vapor-deposited, and the opposite side to this vapor deposition layer Both of these aspects are included.

  Further, in the present invention, a vinyl alcohol film on which a metal or metal oxide is deposited is used as the gas barrier film (A), and a polyester film on which a metal or metal oxide is deposited is used as the polyester film (B). In that case, it is preferable to laminate | stack so that the vapor deposition surface of a vinyl alcohol-type film and the vapor deposition surface of a polyester-type film may face each other.

  When laminating the vapor deposition surfaces so as to face each other, an adhesive or the like is usually used. Examples of the adhesive include an organic titanium compound, an isocyanate compound, and a polyester compound.

  Moreover, although the laminated body [I] of this invention has said layer structure, it may have other layers, such as a seal layer, as well as an adhesive (adhesive) layer.

  In the present invention, the thickness ratio of the gas barrier film (A), the polyester film (B) and the protective film (C) is preferably (A) / (B) / (C) = 1 / 0.5. -3 / 0.5-5, particularly preferably 1 / 1-1.5 / 1-3. If the thickness ratio of each film is out of the above range, the balance between the gas barrier property and the mechanical strength of the bag due to the thickness will be reduced, and in particular, the bag will be too hard and new defects will occur in the wrinkles that occur during sealing. The bag is too soft and tends to cause holes when sealed or used.

The laminate [I] of the present invention is required to have an organic volatile component amount of 0.8 mg / m ² or less measured by a gas chromatography standard test method defined by the Flexible Packaging Sanitation Council. A preferable range of the amount of the organic volatile component is 0.7 mg / m ² or less, and a particularly preferable range is 0.6 mg / m ² or less. If the amount of the organic volatile component is too large, an increase in atmospheric pressure due to the organic volatile component occurs inside the vacuum heat insulating structure that has been depressurized after sealing, and the thermal insulation performance tends to be significantly reduced.

  In the present invention, the organic volatile component is a solvent used for diluting an adhesive used when forming a layer structure, or a dilution of a paint used when forming a paint layer. Solvents used mainly for this purpose are, for example, esters such as ethyl acetate and butyl acetate, ethers such as dimethyl ether and diethyl ether, ketones such as methyl ethyl ketone and acetone, Examples include alcohols such as methanol, ethanol, butanol, and isopropanol. Further, a low molecular weight organic component remaining in the film constituting the laminate [I] of the present invention is also included.

  Examples of the method for adjusting the amount of the organic volatile component to the above range include (1) a method for optimizing the drying conditions of the adhesive at the time of laminating, for example, drying after the adhesive is applied to the first substrate. Methods such as controlling the temperature, air volume or drier residence time, (2) Additional drying after lamination or bag making, (3) Reducing the ultimate vacuum during vacuum packaging There are methods such as extending the time for evacuation and strengthening the packaging conditions. Among them, (2) after laminating or bag making, under the appropriate temperature conditions in terms of easy management and control of residual solvent. A method of additional drying is preferred.

  About the method of said (2), specifically, the laminated body formed by laminating | stacking a gas-barrier film (A), a polyester-type film (B), and a protective film (C) becomes like this. Preferably it is 70-150 degreeC, Especially preferably, Under constant temperature conditions of 80 to 130 ° C., preferably 0.3 hours or more, particularly preferably 0.5 hours or more, more preferably 2 hours or more, preferably 150 hours or less, particularly preferably 100 hours or less, more preferably Can be adjusted to the above range by holding and drying in 80 hours or less.

  In the present invention, as described above, a vinyl alcohol film on which a metal or metal oxide is deposited is used as the gas barrier film (A), and a metal or metal oxide is deposited on the polyester film (B). When the polyester film is laminated so that the vapor-deposited surface of the vinyl alcohol film and the vapor-deposited surface of the polyester-based film face each other, it is particularly preferable to perform drying over time.

  In addition to this method, the inside of the dryer is depressurized and dried at a lower temperature, for example, it is dried at a pressure of 0.001 atm, 60 to 120 ° C., or the film is contacted with a heated material. For example, it can be adjusted by placing it on a metal plate heated to 80 ° C. and drying it in a shorter time.

  In addition, the organic volatile component amount measured by the gas chromatography standard test method defined by the Flexible Packaging Sanitation Council is specifically measured as follows.

That is, the 0.2 m ² size of the multilayer film to be measured is cut or folded so as to fit into a 500 ml Erlenmeyer flask, put into a 500 ml Erlenmeyer flask, sealed with a silicone rubber stopper, 80 After maintaining for 30 minutes in a constant temperature bath at 0 ° C., the gas in the flask was collected with a syringe, and this was collected in a column with PEG-20M (20% on Chromosorb-W (AW-DMCS)), 80/100 mesh, (3 m × 2.6 mm) glass is set, and a gas flow rate of 20 ml / min with carrier gas N ₂ (nitrogen) is injected into a gas chromatograph heated to 80 ° C. The peak of the organic component (e.g., ethyl acetate, methyl ethyl ketone, isopropanol, toluene). Request organic volatile component amount from click strength.

Further, water vapor permeability of the laminate [I] of the present invention is usually less 10g / m ² / day, and further preferably not larger than 8g / m ² / day. If the water vapor permeability of the laminate [I] is too high, excess water vapor will be taken into the laminate, and eventually the water vapor permeability of the gas barrier film (A) will be lowered, and the water vapor permeability of the whole laminate will be reduced. It causes a decrease, and after constructing the vacuum heat insulating structure, there is a tendency that water vapor enters the inside and the performance is remarkably deteriorated.
The water vapor permeability is a value at 23 ° C. × Δ90% RH measured according to JIS Z 0208.

The oxygen permeation amount of the laminate [I] is usually 1 ml / (m ² ) when measured according to the method described in JIS K 7126 (isobaric method) under the condition of 23 ° C.-50% RH. · Day · atm) or less, preferably 0.1 ml / (m ² · day · atm) or less. If the oxygen permeation amount is too high, after the vacuum heat insulating structure is formed as in the case of the water vapor, an outside air constituent gas such as nitrogen or oxygen tends to enter the inside and remarkably deteriorate the performance.

  Next, the vacuum heat insulating structure of the present invention in which the heat insulating material is hermetically packaged by the laminate [I] will be described.

  In packaging such a heat insulating material, the packaging method is, for example, a method of forming an outer bag obtained by processing the laminate [I] into a bag shape, and placing the heat insulating material therein, or the amount of organic volatile components is Form an outer bag that is processed into a bag shape from the laminate before adjustment, put a heat insulating material in it, adjust the amount of organic volatile components before sealing, and make the laminate [I], then seal Or the like can be used.

  The laminate [I] forming the outer bag is preferably provided with a seal layer on the inner surface of the outer bag. As the seal layer, a polyolefin-based resin layer is preferable from the viewpoint of seal strength, and among them, polypropylene, high-density polyethylene, low-density polyethylene, ethylene-vinyl acetate-based resin, and the like are preferably used. For the sealing layer, a film may be prepared separately from the above resin, and the film may be laminated using an adhesive or the like on the inner surface of the outer bag, or the inner side of the outer bag. You may laminate by extruding directly to the surface. When laminating the sealing layer as a film, laminating it as an unstretched film is advantageous in terms of obtaining sealing properties. The thickness of the sealing layer is usually 10 to 100 μm, and particularly preferably 20 to 80 μm.

As a preferable layer structure when the heat insulating material is hermetically packaged by the laminate [I] of the present invention, in particular, from the viewpoint of further reducing the possibility of water vapor entering the vacuum heat insulating structure, the outer layer side (From the opposite side of the heat insulating material)
[Protective film (C) / Adhesive layer / Polyester film (B) / Adhesive layer / Gas barrier film (A) / Adhesive layer / Sealing layer]
In addition, when the gas barrier film (A) and the polyester film (B) have the vapor deposition layer,
(1) [Protective film (C) / adhesive layer / polyester film (B) (deposition surface) / adhesive layer / (deposition surface) gas barrier film (A) / adhesive layer / seal layer],
(2) [Protective film (C) / adhesive layer / (deposition surface) polyester film (B) / adhesive layer / (deposition surface) gas barrier film (A) / adhesive layer / seal layer],
(3) [Protective film (C) / adhesive layer / polyester film (B) (deposition surface) / adhesive layer / gas barrier film (A) (deposition surface) / adhesive layer / seal layer],
(4) [Protective film (C) / adhesive layer / (deposition surface) polyester film (B) / adhesive layer / gas barrier film (A) (deposition surface) / adhesive layer / seal layer],
However, the layer configuration of (1) is most preferable from the viewpoint that the gas barrier property or the water vapor barrier property due to the vapor deposition layer is further increased.

  When manufacturing the vacuum heat insulation structure using the laminate [I], the laminate before the organic volatile component amount is adjusted is processed into a bag shape, and then added to a thermostat at 70 ° C or higher. It is preferable to perform drying.

  As additional drying, it is preferable to dry at 70 ° C. or higher and 150 ° C. or lower, particularly 80 ° C. or higher and 130 ° C. or lower, and further 80 ° C. or higher and 110 ° C. or lower. If the drying temperature is too low, it tends to take too much time to reach the predetermined residual solvent amount. If the drying temperature is too high, the sealing layer used by the outer bag is fused inside the bag, and the inner space of the bag. Tend to be partially blocked.

  Further, the additional drying is generally performed under normal pressure conditions, but can be performed under reduced pressure conditions. In this case, the drying time at the same temperature can be shortened by reducing the pressure as compared with the normal pressure condition.

  Examples of the heat insulating material hermetically packaged by the laminate [I] include fine powders such as alumina, silica and pearlite, glass wool, rock wool, diatomaceous earth, calcium silicate molded body, urethane foam having open cells, carbon Foam, phenol foam, phenol-urethane foam and the like can be used.

  Among these, fibrous heat-insulating materials such as glass wool, granular heat-insulating materials such as granular silicon oxide and foamed resin bodies can retain the shape even when the inside of the outer bag is evacuated, and have bubbles. Therefore, it is preferable in that the heat insulating effect of the vacuum heat insulating structure can be maintained.

  In addition, the heat-insulating material may be mixed with a desiccant such as silica gel or calcium chloride because the moisture content of the gas barrier film (A) used may reduce the degree of vacuum. Is also preferable.

  The heat insulating material is put in an outer bag made of the laminate [I] and vacuum-packed to form a vacuum heat insulating structure. When the heat insulating material is put in the outer bag, the heat insulating material is predetermined. It is preferable to form in the shape (for example, a cube, a rectangular parallelepiped, etc.) in terms of heat insulation performance and workability.

  In the present invention, the vacuum heat insulating structure can be obtained by reducing the pressure in a state where the heat insulating material is put in the outer bag and finally sealing and closing the opening of the bag. The vacuum degree of the vacuum heat insulating structure is preferably 100 Pa or less, more preferably 10 Pa or less, and particularly preferably 5 Pa or less.

  Here, the heat-insulating material is easy to operate at the time of processing or vacuum insulation after compression wrapping by adding processing such as heat compression before inserting into the outer bag. This is preferable in that the shape of the structure is made constant.

  Further, in the present invention, it is preferable to enclose a hygroscopic agent together with the heat insulating material from the viewpoint that the initial heat insulating performance between lots is made constant with high performance.

  As such a hygroscopic agent, when left for 24 hours under the condition of 23 ° C. × 60% RH, it absorbs water vapor or water of 5% or more of its own weight and absorbs water vapor or water of 5% of its own weight. It is a hygroscopic agent that can keep 50% or more of water vapor or water absorbed when it is left for 1 hour at 23 ° C. under a condition of 2500 Pa after moisture absorption. The accompanying one is preferably used.

  Among them, as the hygroscopic agent, a compound or an anhydrous compound in a state where a part or all of the crystal water of the compound is released, for example, a compound or an anhydrous compound in a state where a part or all of 1/2 to 18 hydrate is released. Preferably used. Such hydrates include calcium sulfate hemihydrate, calcium chloride hexahydrate, magnesium chloride (2,4,6) hydrate, copper sulfate pentahydrate, magnesium sulfate heptahydrate. And aluminum sulfate 18 hydrate. Among these types of hygroscopic agents, for example, calcium chloride-based desiccant using anhydrous calcium chloride or calcium chloride monohydrate, or magnesium chloride-based desiccant, tin chloride-based desiccant, sodium sulfate-based A desiccant etc. are mentioned.

  In addition, as the hygroscopic agent, a hygroscopic agent that causes a chemical reaction with surrounding moisture, that is, a hygroscopic agent that forms a separate compound before and after moisture absorption is also preferably used. Examples of this type of hygroscopic agent include phosphorus pentoxide, calcium oxide, magnesium oxide and the like. Each of these compounds absorbs moisture by reacting with moisture to change into phosphoric acid, calcium hydroxide, magnesium hydroxide or the like.

  Such a non-re-releasing hygroscopic agent preferably absorbs water vapor of 5% or more of its own weight when left for a fixed time of 24 hours under normal pressure and normal humidity conditions such as 23 ° C. × 60% RH. If the amount of moisture absorption is less than 5% of its own weight, it is necessary to enclose a considerable amount of moisture absorbent in the vacuum heat insulating structure, and the heat insulation performance of this moisture absorbent is inferior to that of standard silica gel or glass wool. Since there exists a tendency, there exists a tendency which causes the fall of the heat insulation performance as a vacuum heat insulation structure.

  Further, as non-re-releasing properties, when a hygroscopic agent that has absorbed 5% of its own weight is left at 23 ° C. under a condition of 2500 Pa for 1 hour, 50% or more of the absorbed water vapor or water is not contained in the hygroscopic agent itself. It is important to keep it inside, and if the retention rate is less than 50%, it is difficult to say that it is non-re-releasing, and the heat insulation performance is reduced due to the decrease in the degree of vacuum due to the re-release of water vapor. Probability tends to increase and reliability is difficult to obtain.

  As a method of packaging these hygroscopic agents into a vacuum heat insulating structure, the hygroscopic agent can be packaged in the form of powder or flakes and mixed with the internal heat insulating material, or only the hygroscopic agent can be packaged with high permeability. It is also possible to individually wrap with a material and wrap it with a heat insulating material. In this case, the highly permeable packaging material includes paper, non-woven fabric, woven fabric, cellophane film, etc., and these can be used alone or in combination. It is also possible to form a composite by applying a hygroscopic agent to the surface of paper, nonwoven fabric or the like, and wrap it with a heat insulating material.

  The amount of the hygroscopic agent used is preferably 0.01 to 10 parts by weight and more preferably 0.1 to 5 parts by weight with respect to 100 parts by weight of the internal heat insulating material. If the amount of the hygroscopic agent is too small, the degree of vacuum of the vacuum heat insulating structure of the present invention tends to decrease, and if the amount is too large, the hygroscopic agent is more expensive than the heat insulating structure, so the economics of the vacuum heat insulating structure is significantly reduced. There is a tendency to make it. In addition, in this invention, you may use together hygroscopic agents used conventionally, such as silica gel other than the said hygroscopic agent.

  In the present invention, the shape and size of the vacuum heat insulating structure are not particularly limited, and may be determined according to the purpose. For example, the shape of the vacuum heat insulating structure may be a shape that includes one outer bag for one vacuum heat insulating structure, or a shape that includes a plurality of outer bags for one vacuum heat insulating structure. It may be a thing.

  In the case of a shape including a plurality of such exterior bags, the seal part that becomes a joint between the exterior bag parts becomes a thin part in the vacuum heat insulation structure, and deformation when the vacuum heat insulation structure is deformed Therefore, the vacuum heat insulating structure can be easily deformed, which is preferable.

  Furthermore, even when a hole or the like is generated due to an external factor, and the vacuum property of the vacuum heat insulating structure is lost, the decrease in the heat insulating property is kept to a minimum if the shape includes a plurality of exterior bags. Can be preferable.

  As for the size of such a vacuum heat insulating structure, it is generally processed into a rectangular parallelepiped shape having a thickness of 5 to 100 mm and a length and width of 100 to 2000 mm. If the volume of the vacuum insulation structure is unnecessarily large, the area that loses performance increases when a defect such as a hole occurs in the outer bag, which may reduce the performance of the final product using the vacuum insulation structure. Therefore, it is preferable to set the size appropriately.

  Thus, in the present invention, a vacuum heat insulating structure that has excellent heat insulating performance and that does not deteriorate when used for a long period of time can be obtained. Such vacuum heat insulating structures include household appliances such as cooler boxes and bottle cases, household appliances such as refrigerators, jar pots, rice cookers, housing equipment such as water heaters, bathtubs, unit baths, toilet seats, floor heating, solar roofs, Although it can be effectively used as a heat insulating material such as a housing system such as a low-temperature radiation plate and a housing building material such as a heat insulating panel for an outer wall, among them, it can be particularly suitably used as a heat insulating material for a refrigerator.

EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated further more concretely, this invention is not limited to a following example, unless the summary is exceeded.
In the examples, “parts” and “%” mean weight basis.

<Example 1>
The following films were prepared.
[Gas barrier film (A)]
(Biaxially stretched PVA film (A-1))
From a hopper of a twin-screw extruder type kneader (screw L / D = 40) whose jacket temperature is set to 60 to 150 ° C., a PVA (polymerization degree 1700, viscosity of 4 wt% aqueous solution 40 mPa · s, saponification degree 99.7) Mol%, sodium acetate content 0.3%) and water at a PVA / water weight ratio of 40/60 were supplied by a metering pump, kneaded, and discharged under conditions of a discharge amount of 500 kg / hr.
This discharged material was immediately pumped to a single screw extruder (screw L / D = 30), kneaded at a temperature of 85-140 ° C., extruded from a T-die onto a 5 ° C. cast roll, and then heated at 90 ° C. with a hot air dryer. The film was dried for 2 seconds to prepare a PVA film (thickness 150 μm) having a water content of 25%. Subsequently, the PVA film was stretched 3.8 times in the MD direction, then stretched 3.8 times in the TD direction with a tenter, and then heat-fixed at 180 ° C. for 8 seconds to form a biaxially stretched PVA film (thickness 12 μm) (A -1) was obtained.

(Aluminum vapor-deposited biaxially stretched PVA film (A-2))
On one side of the biaxially stretched PVA film (A-1) obtained above, metal aluminum was vacuum evaporated by a vacuum vapor deposition apparatus using an electron beam heating method, and an aluminum vapor deposited biaxially stretched PVA film (A- 2) was obtained.

(Aluminum-deposited biaxially stretched EVOH film (A-3))
40mmφ single screw extruder (L / D = 28) using full flight type screw with compression ratio of 3.4 and 600mm width coat hanger die (L / D = 28), ethylene content 32 mol%, saponification degree 99.6 mol%, melt An EVOH film having a thickness of 125 μm was produced by a take-up device having EVOH extruded at a flow rate value (MFR) of 3.2 g / 10 min and having a cooling roll controlled at 30 ° C. in the first roll.
After adjusting the moisture content to 12% by passing the EVOH film through a humidity control zone at 80 ° C. and a humidity of 90%, it is longitudinally and laterally adjusted by a continuous simultaneous biaxial stretching machine adjusted to a bath temperature of 100 ° C. Each film was stretched 3.2 times and then continuously subjected to heat treatment at 155 ° C. for 5 seconds to obtain a biaxially stretched EVOH film having a thickness of 12 μm.
On one side of the obtained biaxially stretched EVOH film, metal aluminum was vacuum evaporated by a vacuum vapor deposition apparatus using an electron beam heating method, to obtain an aluminum vapor deposited biaxially stretched EVOH film (A-3) having a thickness of 600 mm.

[Polyester film (B)]
Metal aluminum was vacuum evaporated on one smooth surface of a 12 μm thick biaxially stretched polyester film (trade name “Cosmo Shine” manufactured by Toyobo Co., Ltd.), and an aluminum-deposited biaxially stretched polyester film (B− 1) was obtained.

[Protective film (C)]
A 25-μm thick biaxially stretched polypropylene film (C-1) (trade name “Pyrene OT” manufactured by Toyobo Co., Ltd.) was prepared. The water vapor transmission rate of this film at 23 ° C. × Δ90% RH was measured and found to be 7.2 g / m ² / day.

(Seal layer)
A non-stretched polypropylene film having a thickness of 30 μm (trade name “Pyrene CT” manufactured by Toyobo Co., Ltd.) was prepared.

Using each of the above films, a vacuum heat insulating structure was produced as follows.
On the surface of the aluminum vapor-deposited polyester film (B-1) which has not been subjected to the vapor deposition treatment, 17 parts of the main agent for adhesive “Takelac A626” (Mitsui Chemicals) and the hardener for adhesive “Takenate A50” (Mitsui Chemicals) ) A dry laminating machine in which 17 parts of ethyl acetate mixed with 66 parts of dry laminating adhesive was applied by a gravure coater using a gravure roll with a mesh of 100 μm to a coating amount of 10 g / m 2 and heated to 80 ° C. Through the inside, the residence time was 12 seconds, and after drying, the coating amount was 3.4 g / m ^2, and the laminate pressure was 3.5 kg / cm ² , and the biaxially stretched polypropylene film (C-1) was bonded. A laminate (1) was obtained.

Next, 17 parts of an adhesive main agent “Takelac A626” (Mitsui Chemicals) and an adhesive curing agent “Takenate A50” (Mitsui Chemicals) Coated with a gravure coater using a gravure roll with a mesh of 100 μm so that the coating amount is 10 g / m ^2, and heated to 80 ° C. Through the dryer, the residence time was 20 seconds, the coating amount after drying was set to 3.4 g / m ^2, and then the laminate (1) aluminum-deposited polyester at a laminating pressure of 3.5 kg / cm ^2. The film (B-1) was bonded to the aluminum-deposited surface to obtain a laminate (2a).

Next, on the surface of the laminate (2a) obtained above which is not subjected to the vapor deposition treatment of the aluminum vapor-deposited PVA film (A-2), 17 parts of an adhesive main agent “Takelac A626” (manufactured by Mitsui Chemicals) and Adhesive hardener “Takenate A50” (manufactured by Mitsui Chemicals, Inc.) A dry laminating adhesive in which 66 parts of ethyl acetate was mixed with a gravure roll having a mesh of 100 μm was applied to a coating amount of 10 g / m ² . It was applied with a gravure coater, passed through a dryer heated to 80 ° C., and after a residence time of 12 seconds, the coating amount after drying was set to 3.4 g / m ^2, and then the lamination pressure was 3.5 kg / cm ² . Then, an unstretched polypropylene film having a thickness of 30 μm was bonded to obtain a laminate (3a) (outside: biaxially stretched polypropylene film / adhesive layer / aluminum-deposited polyester film (deposited surface)). Adhesive layer / (deposition surface) aluminum deposited biaxially oriented PVA film / adhesive layer / unstretched polypropylene film: the inside).

The obtained laminate (3a) was left for 4 days in an aging room maintained at 40 ° C. in the form of a roll to complete the curing reaction of each adhesive layer.
About the obtained laminated body (3a), it was 1.52 mg / m < ² > when the amount of organic volatile components measured by the gas chromatography standard method which a soft packaging hygiene meeting establishes was measured.

The amount of the organic volatile component was measured by the following method.
After a 0.2 m ² minutes of the laminated film to be measured smaller folded to an extent that fall within Erlenmeyer flask 500 ml, it was placed in a conical flask 500 ml, sealed with silicone rubber stopper, a thermostat at 80 ° C. After holding in the flask for 30 minutes, the gas in the flask was collected with a syringe, and this was collected in a column with PEG-20M (20% on Chromosorb-W (AW-DMCS)), 80/100 mesh, (3 m × 2.6 mm). ) Glass is set, carrier gas N ₂ (nitrogen) is used at a gas flow rate of 20 ml / min, and an injection gas amount of 1 ml is injected into a gas chromatograph heated to 80 ° C., and methanol, ethyl acetate, methyl ethyl ketone, isopropanol are prepared from a separately prepared calibration curve. The toluene peak is identified, and the amount of volatile components is determined from the peak intensity. The amount of the starting component was taken.

  A 30 cm square sheet is cut from the above laminate (3a), and two of these sheets are used to overlap the surfaces of the unstretched propylene film, and the three sides of the four sides are sealed with a width of 10 mm from the end. By heat-sealing at a temperature of 130 ° C., a three-side sealed packaging bag (4a) was obtained.

Laminate commercially available fine glass wool (Mag Izobale, “WR800”) to 2 kg / m ² , heat it to 630 ° C., compress it with a load until it reaches a thickness of 10 mm, Was slowly cooled and then cut into 20 cm square to obtain a heat insulating material (5).

  The heat insulating material (5) is again left in a thermostatic bath at 150 ° C. for 1 hour to dry, then immediately inserted into the center of the three-side sealed packaging bag (4a), and in this state, the thermostatic bath at 100 ° C. And left to dry for 12 hours.

The amount of the organic volatile component measured for the laminate (laminate [I]) constituting the three-side sealed packaging bag (4a) at this time was 0.51 mg / m ² .

  After the drying, 3 g of quicklime desiccant in a nonwoven fabric of polypropylene is enclosed in the inner edge of the three-side sealed packaging bag (4a) and immediately placed in a vacuum packaging machine, and at a pressure of 2.0 Pa in the vacuum packaging machine. Sealed under reduced pressure to obtain a vacuum heat insulating structure (6a).

The obtained vacuum heat insulating structure (6a) was left in a constant temperature room maintained at 20 ° C. for 24 hours, and then the thermal conductivity was measured with a thermal conductivity measuring device “HC-074-304” (manufactured by Eihiro Seiki Co., Ltd.). It was 2.4 mW / mK when measured.
The vacuum heat insulating structure (6a) was left in a constant temperature bath at 70 ° C. for 10 days, and the thermal conductivity was measured in the same manner. As a result, it was 2.8 mW / mK.

<Example 2>
Using the biaxially stretched PVA film (A-1), a laminate (3b) was obtained in the same manner as in Example 1 except that this was directly used as a gas barrier film (A) (outside: biaxially stretched). Polypropylene film / adhesive layer / aluminum-deposited polyester film (deposition surface) / adhesive layer / biaxially stretched PVA film / adhesive layer / unstretched polypropylene film: inside).
The obtained laminate (3b) was left for 4 days in an aging room maintained at 40 ° C. in the form of a roll to complete the curing reaction of each adhesive layer.
The amount of organic volatile components of the laminate (3b) was 1.15 mg / m ² .
Using the obtained laminate (3b), a three-side sealed packaging bag (4b) was produced in the same manner as in Example 1, and the same compression-molded glass wool insulating material (5) as in Example 1 was used. After leaving it to stand in a constant temperature bath at 150 ° C for 1 hour, immediately insert it into the center of the previous three-side sealed packaging bag (4b) and leave it in a constant temperature bath at 100 ° C for 1 hour to dry it. It was.
The amount of organic volatile components of the laminate (laminate [I]) constituting the three-sided sealed packaging bag (4b) after drying was 0.38 mg / m ² .
Then, it vacuum-packed by operation similar to Example 1, and obtained the vacuum heat insulation structure (6b).

The vacuum heat insulating structure (6b) was left in a temperature-controlled room maintained at 20 ° C. for 24 hours, and then the thermal conductivity was measured and found to be 2.3 mW / mK.
After this vacuum heat insulating structure (6b) was left in a thermostat at 70 ° C. for 10 days, the thermal conductivity was measured in the same manner to find 3.0 mW / mK.

<Example 3>
A laminated body (3c) was obtained in the same manner as in Example 1 except that an aluminum-deposited biaxially stretched EVOH film (A-3) was used as the gas barrier film (A) (outside: biaxial). Stretched polypropylene film / adhesive layer / aluminum-deposited polyester film (deposition surface) / adhesive layer / (deposition surface) aluminum-deposited biaxially-stretched EVOH film / adhesive layer / unstretched polypropylene film: inside).
The obtained laminate (3c) was allowed to stand for 4 days in an aging room maintained at 40 ° C. in the form of a roll to complete the curing reaction of each adhesive layer.
With respect to the laminate (laminate [I]) constituting the three-side seal packaging bag (4c) at this time, the amount of the organic volatile component was measured and found to be 0.98 mg / m ² .
Using the obtained laminate (3c), a three-side sealed packaging bag (4c) was produced in the same manner as in Example 1, and the same compression-molded glass wool insulating material (5) as in Example 1 was used. After leaving in a thermostatic bath at 150 ° C for 1 hour to dry, immediately insert it into the central part of the previous three-side seal packaging bag (4c) and leave it in a thermostatic bath at 100 ° C for 3 hours to dry. It was.
The amount of organic volatile components of the laminate (laminate [I]) constituting the dried three-side sealed packaging bag (4c) was 0.15 mg / m ² .
Then, it vacuum-packed by operation similar to Example 1, and obtained the vacuum heat insulation structure (6c).

The vacuum heat insulating structure (6c) was left in a temperature-controlled room maintained at 20 ° C. for 24 hours, and the thermal conductivity was measured to be 2.4 mW / mK.
After this vacuum heat insulating structure (6c) was left in a thermostat at 70 ° C. for 10 days, the thermal conductivity was measured in the same manner to find that it was 3.1 mW / mK.

<Comparative Example 1>
After using the laminate (3a) obtained in the same manner as in Example 1 to obtain a three-sided seal packaging bag (4a) in the same manner as in Example 1, 150 in the center of this three-sided seal packaging bag (4a). The heat insulating material (5) that had been dried at 1 ° C. for 1 hour was inserted, and in this state, it was left in a constant temperature bath at 100 ° C. for 10 minutes for drying.

The amount of the organic volatile component of the laminate constituting the three-sided sealed packaging bag (4a ′) after drying was 1.48 mg / m ² .
Thereafter, vacuum packaging was performed in the same manner as in Example 1 to obtain a vacuum heat insulating structure (6a ′).

The vacuum heat insulating structure (6a ′) was left in a constant temperature room maintained at 20 ° C. for 24 hours, and the thermal conductivity was measured to be 2.6 mW / mK.
The vacuum heat insulating structure (6a ′) was left in a constant temperature bath at 70 ° C. for 10 days, and the thermal conductivity was measured in the same manner to find that it was 4.5 mW / mK.

<Comparative example 2>
After using the laminate (3c) obtained in the same manner as in Example 3 to obtain a three-sided seal packaging bag (4c) in the same manner as in Example 1, 150 in the center of this three-sided seal packaging bag (4c). The heat insulating material (5) that had been dried at 1 ° C. for 1 hour was inserted, and in this state, it was left in a constant temperature bath at 100 ° C. for 10 minutes for drying.

With respect to the laminate constituting the three-side sealed packaging bag (4c ′) after drying, the amount of organic volatile components was measured and found to be 1.14 mg / m ² .
Thereafter, vacuum packaging was performed in the same manner as in Example 1 to obtain a vacuum heat insulating structure (6c ′).

The vacuum heat insulating structure (6c ′) was left in a temperature-controlled room maintained at 20 ° C. for 24 hours, and the thermal conductivity was measured to be 2.4 mW / mK.
The vacuum heat insulating structure (6c ′) was left in a constant temperature bath at 70 ° C. for 10 days, and the thermal conductivity was measured in the same manner to find 5.3 mW / mK.

  From the above results, in the case of an example in which the amount of organic volatile components of the laminate is less than or equal to a predetermined range as an exterior bag of a vacuum heat insulating structure, there is no outflow of organic volatile components and it can be used for a long time at high temperatures. In the case of the comparative example exceeding the predetermined range without any particular adjustment with respect to the amount of organic volatile components of the laminate, the initial heat insulation Although it has performance, after a long period of time, the heat insulation performance is reduced, and it can be seen that the vacuum heat insulation structures of the examples are superior.

In the vacuum heat insulating structure of the present invention, a heat insulating material is packaged by a laminate [I] obtained by laminating a gas barrier film (A), a polyester film (B), and a protective film (C) with an adhesive. In the laminate [I], the amount of organic volatile components measured by the gas chromatography standard test method defined by the Flexible Packaging Hygiene Council is 0.8 mg / m ² or less. Of course, it becomes a vacuum heat insulation structure that does not deteriorate the heat insulation performance even when used for a long time, household appliances such as cooler boxes, bottle cases, household appliances such as refrigerators, jar pots, rice cookers, water heaters, Effectively used as thermal insulation for housing equipment such as bathtubs, unit baths, toilet seats, etc., floor heating, solar roofs, low-temperature radiation panels, etc. Among them, among these, it can be particularly suitably used as a heat insulating material for a refrigerator.

Claims (9)

A gas insulation film (A), a polyester film (B), and a protective film (C) are laminated with a laminate [I], and a vacuum insulation structure in which a heat insulating material is packaged. A vacuum heat insulating structure characterized in that the amount of organic volatile components measured by a gas chromatography standard test method defined by the Flexible Packaging Sanitation Council in the laminate [I] is 0.8 mg / m ² or less. Laminate [I] has a layer structure of gas barrier film (A) / polyester film (B) / protective film (C), and heat-insulating material is hermetically sealed with the gas barrier film (A) inside. The vacuum heat insulating structure according to claim 1, wherein: The vacuum heat insulating structure according to claim 1 or 2, wherein the gas barrier film (A) is a vinyl alcohol film. 4. The vacuum heat insulating structure according to claim 3, wherein the vinyl alcohol film is a vinyl alcohol film on which a metal or a metal oxide is deposited. The vacuum heat insulating structure according to claim 3 or 4, wherein the vinyl alcohol film is a biaxially stretched polyvinyl alcohol film. The vacuum heat insulating structure according to any one of claims 1 to 5, wherein the polyester film (B) is a polyester film on which a metal or a metal oxide is deposited. The vacuum insulating structure according to any one of claims 1 to 6, wherein the protective film (C) is a polyolefin-based film. Laminate [I] is laminated such that the vapor deposition surface of a vinyl alcohol film on which a metal or metal oxide is vapor-deposited and the vapor deposition surface of a polyester film on which a metal or metal oxide is vapor-deposited face each other. The vacuum heat insulating structure according to claim 4 or 6. Organic volatile component measured by gas chromatography standard test method defined by the Flexible Packaging Sanitation Council, which is formed by laminating gas barrier film (A), polyester film (B), and protective film (C) with an adhesive. A laminate having an amount of 0.8 mg / m ² or less.