JP2018141517A - Vacuum heat insulation material, equipment including the same and manufacturing method of vacuum heat insulation material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vacuum heat insulation material which can prevent intrusion of a gas to the inside of an outer packaging material and which can prevent lowering of heat insulation characteristics for a long time, and equipment including the same and a manufacturing method of vacuum heat insulation material.SOLUTION: A vacuum heat insulation material includes: a core material; and an outer packaging material comprising a pair of laminated films (10a, 10b) provided facing with each other by sandwiching the core material. The laminated films (10a, 10b) are a substance in which surface protection layers (5a, 5b), protection layers (6a, 6b), gas barrier layers (7a, 7b) and thermal fusion layers (8a, 8b) are laminated in this order from the outside sequentially. At an end part (4) of the pair of laminated films, the respective thermal fusion layers (8a,8b) of the pair of laminated films are bonded with each other. Angles α formed by a bonded surface (81) of the respective thermal fusion layers (8a, 8b) of the pair of laminated films and surfaces (80a, 80b) on the outside of the respective thermal fusion layers (8a, 8b) of the pair of laminated films are acute angles.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a vacuum heat insulating material, a device including the same, and a method for manufacturing the vacuum heat insulating material.

  In recent years, from the viewpoint of protecting the global environment or from the viewpoint of energy saving, improvement in heat insulation of home appliances and industrial equipment has been studied. Resin foams and organic or inorganic fibers are used as the heat insulating material for insulating the equipment. However, in order to improve the heat insulating property, the heat insulating material needs to be thickened. However, when the heat insulating material is thickened, the volume of the entire device increases, and problems such as a reduction in the proportion of space in which components and the like can be mounted arise.

  In order to solve such a problem, a vacuum heat insulating material excellent in heat insulating properties as compared with the above-described resin foam, organic or inorganic fibers, etc. has been proposed. The vacuum heat insulating material is a bag-shaped outer packaging material (laminate film) having a gas barrier property, a core material made of a fiber assembly and a getter agent for gas adsorption are put inside, the inside of the bag is decompressed, and the end of the bag It is a thing produced by sealing. Compared to conventional heat insulating materials such as resin foam and organic or inorganic fibers, the heat insulating property is 20 to 40 times, so that sufficient heat insulation can be performed even if the heat insulating material is thinned.

  On the other hand, heat transfer of the vacuum heat insulating material is caused by heat conduction, radiation, and convective heat transfer of solid components and gas components existing in the space. When a vacuum heat insulating material is used in a temperature range below room temperature, heat conduction due to radiation is small and negligible. Furthermore, since the vacuum heat insulating material puts the core material in the bag-shaped outer packaging material and depressurizes the inside, when the heat conduction of the solid is constant, the heat conductivity is suppressed by suppressing the heat conduction of the gas component. Can be reduced. That is, a vacuum heat insulating material with higher heat insulation can be obtained by reducing the internal pressure. In general, the outer packaging material used for the vacuum heat insulating material is a laminate of a plurality of plastic films, but the plastic film alone has insufficient gas barrier properties. Are known.

  As a known example of the vacuum heat insulating material, there is, for example, Patent Document 1. Patent Document 1 discloses a laminate film formed by laminating a heat seal layer, a gas barrier layer, a polyethylene film layer having a Young's modulus of 200 MPa or less in JISK7127 or a polypropylene film layer, and a protective layer in this order. .

JP 2006-21429 A

  However, when the vacuum heat insulating material as described above is used in an apparatus, it is known that the heat insulating properties deteriorate over time due to the gas gradually entering through the outer packaging material and the internal pressure rising.

  In view of the above circumstances, the present invention is a vacuum heat insulating material capable of preventing gas from entering the outer packaging material and preventing deterioration of heat insulating characteristics over a long period of time, and an apparatus and a vacuum heat insulating material including the same It aims at providing the manufacturing method of.

  In order to solve the above problems, the present invention includes a core material and an outer packaging material made of a pair of laminated films provided to face each other with the core material interposed therebetween. A layer, a protective layer, a gas barrier layer, and a heat welding layer are laminated in this order, and at each end of the pair of laminated films, the respective heat welding layers of the pair of laminated films are joined together, There is provided a vacuum heat insulating material characterized in that an angle α formed by a bonding surface of each heat-welded layer of the laminated film and an outer surface of each heat-welded layer of the pair of laminated films is an acute angle.

  Moreover, this invention provides the apparatus provided with the said vacuum heat insulating material.

  Furthermore, the present invention includes a core material and an outer packaging material made of a pair of laminated films provided to face each other with the core material interposed therebetween, and the laminated film comprises a surface protective layer, a protective layer, and a gas barrier in order from the outside. A method of manufacturing a vacuum heat insulating material in which a layer and a heat-welded layer are laminated in this order, a step of producing a pair of laminated films, a core material disposed inside the pair of laminated films, Bonding the respective thermal welding layers of the pair of laminated films at the end of the laminated film, and in the step of bonding the respective thermal welding layers of the pair of laminated films, The heat welding layers of the pair of laminated films are heat-welded so that an angle α formed by a bonding surface of the heat welding layers and an outer surface of each of the pair of laminated films is an acute angle. A method for producing a vacuum heat insulating material is provided.

  More specific configurations of the present invention are described in the claims.

  ADVANTAGE OF THE INVENTION According to this invention, the vacuum heat insulating material which can prevent the penetration | invasion of the gas to the inside of an outer packaging material, and can prevent the deterioration of a heat insulation characteristic over a long period of time, the apparatus provided with it, and the manufacturing method of a vacuum heat insulating material Can be provided.

  Problems, configurations, and effects other than those described above will become apparent from the following description of embodiments.

The schematic diagram which shows the cross section of the vacuum heat insulating material which concerns on this invention. The figure which expands the A section of FIG. The schematic diagram which shows the cross section of the conventional vacuum heat insulating material. The figure which expands the B section of FIG. The schematic diagram which shows the cross section of an example of the apparatus (refrigerator) provided with the vacuum heat insulating material which concerns on this invention. The schematic diagram which shows the cross section of an example of the apparatus (heat pump water heater) provided with the vacuum heat insulating material which concerns on this invention. The cross-sectional schematic diagram which shows an example of the laminator used for the manufacturing method of the vacuum heat insulating material which concerns on this invention. The figure which expands the C section of FIG. The flowchart which shows an example of the manufacturing method of the vacuum heat insulating material which concerns on this invention.

  Hereinafter, embodiments according to the present invention will be described in detail.

[Vacuum insulation]
FIG. 1 is a schematic view showing a cross section of a vacuum heat insulating material according to the present invention. As shown in FIG. 1, the vacuum heat insulating material 1 includes an outer packaging material 3, a core material 2 accommodated in the outer packaging material 3, and an adsorbent (getter agent 11). The outer packaging material 3 is sealed by bonding a pair of laminated films 10a and 10b by thermal welding at end portions (portion A in FIG. 1). The adsorbent 11 is enclosed in the outer packaging material 3 as necessary, and is not an essential component in the present invention.

  FIG. 2 is an enlarged view of portion A in FIG. As shown in FIG. 2, the laminated film 10 a constituting the outer packaging material 3 has a first layer (surface protection) from an outer surface in contact with the outside air (a surface on the opposite side to the surface in contact with the vacuum inside of the outer packaging material 3). Layer) 5a, second layer (protective layer) 6a, third layer (gas barrier layer) 7a, and heat-welded layer 8a are laminated in this order. The laminated film 10b has the same configuration as the laminated film 10a. As described above, the outer packaging material 3 is sealed by laminating the laminated films 10a and 10b and heat-welding the end portions (heat-welded portions and joint portions) 4 of the heat-welded layers 8a and 8b. A surface on which the heat-welded layers 8a and 8b are bonded by heat welding is referred to as a bonding surface 81.

  In the present invention, an angle α (enlarged in FIG. 2) formed by the joining surface 81 and the outer surfaces 80a, 80b of the heat-welded layers 8a, 8b in the heat-welded portion 4 is an acute angle ( 0 ° <α <90 °). In other words, the heat welding layers 8 a and 8 b are thinned toward the outer periphery of the vacuum heat insulating material 1. With such a configuration, only the end faces 82 of the heat welding layers 8a and 8b are exposed to the outside air, and other portions of the heat welding layers 8a and 8b are almost covered with the other layers of the laminated films 10a and 10b. It has a structure.

  Here, the structure of the conventional vacuum heat insulating material is demonstrated. FIG. 3 is a schematic view showing a cross section of a conventional vacuum heat insulating material, and FIG. 4 is an enlarged view of a portion B in FIG. As shown in FIGS. 3 and 4, the outer packaging material 3 ′ of the conventional vacuum heat insulating material 1 ′ is bonded to the outer surfaces 80 a ′ and 80 b ′ of the heat welding layers 8 a ′ and 8 b ′ in the heat welding portion 4 ′. 81 'is parallel to each other, and the areas of the end faces 82a' and 82b 'exposed to the outside air of the weld layers 8a' and 8b 'are larger than in the case of the present invention shown in FIG.

  The gas that enters the inside of the outer packaging material 3 is a gas that enters from the stacking direction of the layers 5a ′ to 8a ′ and 5b ′ to 8b ′ constituting the outer packaging material 3 (from the surface of the first layer (surface protective layer) 5a). Intruding gas) 30 and gas entering from a direction perpendicular to the stacking direction of the outer packaging material 3 (gas entering from the end faces 82a ′ and 82b ′ of the heat welding layers 8a ′ and 8b ′) 31 are conceivable. According to the knowledge obtained by the present inventor, even if the first layer (surface protective layer) 5a ′ is made of aluminum foil and the intrusion of the gas 30 from the stacking direction of the outer packaging material 3 ′ is suppressed, the inside of the outer packaging material 3 ′ It was found that the heat pressure increased and the thermal conductivity increased (insulation characteristics deteriorated). That is, in order to reduce the gas intruding into the outer packaging material 3 ′, not only the gas 30 enters from the stacking direction of the outer packaging material 3 ′ but also the end faces 82 a ′ and 82 b of the heat-welded layers 8 a ′ and 8 b ′. It is necessary to suppress the gas 31 entering from '.

  As described above, in the conventional configuration, the end portion of the outer packaging material 3 ′ is in contact with the outside air, and gas enters through this portion over time, and the pressure inside the vacuum heat insulating material 1 ′ increases. As a result, the thermal conductivity is increased. In particular, the heat-welded layers 8a ′ and 8b ′ are disposed closer to the inside than the gas barrier layers 7a ′ and 7b ′, and tend to be thicker than other layers. , The structure is easy for gas to enter.

  Therefore, in the present invention, as shown in FIG. 2, most of the end faces of the heat-welded layers 8a and 8b are covered with other layers of the laminated film constituting the outer packaging material 3, and the heat-welded layers 8a and 8b The part which touches external air was reduced as much as possible, the gas intrusion into the outer packaging material 3 was prevented, and the heat insulating property could be prevented from deteriorating over a long period of time.

  Patent document 1 mentioned above aims at maintaining the heat insulation characteristic by suppressing the invasion of gas from the end face of the vacuum heat insulating material. Specifically, a vacuum heat insulating material in which a cross section of a laminate film used as a covering material of a vacuum heat insulating material is coated with an ethylene polyvinyl alcohol copolymer or a polyacrylic acid resin is disclosed. However, although the gas permeability of the ethylene polyvinyl alcohol copolymer or polyacrylic acid resin used in the coating is relatively low, the amount of permeation is not zero, so that the heat insulation characteristics deteriorate. In addition, the use of a resin material for coating the end face and the number of coating processes increase, leading to an increase in cost.

  In the present invention, the angle α may be an angle at which the end faces of the heat welding layers 8a and 8b are almost covered. The angle α is preferably 3 ° or less. By setting the angle α to 3 ° or less, gas intrusion from a direction perpendicular to the stacking direction of the outer packaging material 3 can be suppressed. In addition, the angle α varies depending on the thickness of the weld layer and the width of the heat-welded portion 4 (to be described later) (the size of the portion indicated by the arrow in FIG. 2). It is preferable to do. In addition, angle (alpha) can be measured by cross-sectional observation with an electron microscope (Scanning Electron Microscope, SEM).

  The width (seal width) of the heat-welded portion (joint surface) 4 is preferably 7 to 20 mm (7 mm or more and 20 mm or less). The width of the heat-welded portion 4 depends on the angle α. If the width is larger than 20 mm, the ratio to the entire outer packaging material is increased and the efficiency is poor, and if it is less than 7 mm, the adhesive strength is reduced. Therefore, the width is preferably 7 to 20 mm.

Furthermore, it is preferable that the thickness of the heat-welded layers 8a and 8b (thickness before heat-welding, that is, thickness of a portion other than the heat-welded portion 4) is 30 × 10 ⁻⁶ m or more. As a result, gas intrusion from the end faces of the weld layers 8a and 8b is reduced, and the change in thermal conductivity over time can be reduced by suppressing the pressure rise inside the vacuum heat insulating material.

  First layer (surface protective layer) 5a, 5b, second layer (protective layer) 6a, 6b, third layer (gas barrier layer) 7a, 7b, heat welded layer 8a, 8b, core material 2 and deoxidizing material 11 Can use a conventionally used material. For example, as the first layer (surface protective layer) 5a and the second layer (protective layer) 6a, stretched products such as a polyethylene terephthalate film, a polyamide film, and a polypropylene film can be used. As the third layer (gas barrier layer) 7a, a metal vapor-deposited film, an inorganic vapor-deposited film, a metal foil, or the like can be used. As the heat welding layers 8a and 8b, a low density polyethylene film, a high density polyethylene film, a polypropylene film, a polyacrylonitrile film, an unstretched polyethylene terephthalate film, a linear low density polyethylene film, or the like can be used.

  As the core material 2 having the role of a spacer, it is desirable to use a member having a high porosity from the viewpoint of reducing thermal conductivity. Moreover, it is desirable that the voids inside the core material 2 have a continuously connected shape so that the gas can be removed by decompression. As an example of a material having such characteristics, there is a fiber assembly in which inorganic materials are fiberized and accumulated. A fiber assembly is made by using glass such as soda lime glass as a raw material and fiberizing the molten glass material by a stretching method or a flame method, and after fiberization, it is collected by a conveyor having a suction function. .

  Moreover, after dispersing the glass fiber produced by the melt drawing method in water, the inorganic fiber sheet produced by the wet method for accumulating and forming the sheet or the fiber produced by the melt drawing method are accumulated and then molded by applying heat and pressure. A core material such as an inorganic fiber mat can be used. Furthermore, in order to remove the moisture adsorbed on the fiber surface before use, the inorganic fiber as the core material is desirably dried by heating, thereby reducing the time for evacuating the vacuum heat insulating material. be able to.

  Further, it is preferable to enclose an adsorbent (getter agent) 11 that adsorbs the residual gas and moisture after vacuum sealing together with the core material 2. As the getter agent, molecular sieves, silica gel, calcium oxide, synthetic zeolite, activated carbon, potassium hydroxide, sodium hydroxide, lithium hydroxide and the like can be used.

[Equipment with vacuum insulation]
Next, the example of the apparatus provided with the vacuum heat insulating material which concerns on this invention mentioned above is demonstrated. FIG. 5 is a schematic view showing a cross section of an example of a device (refrigerator) provided with the vacuum heat insulating material according to the present invention, and FIG. 6 shows a cross section of an example of a heat pump water heater using the vacuum heat insulating material according to the present invention. It is a schematic diagram.

  The refrigerator box body of the refrigerator 12 shown in FIG. 5 is a combination of the refrigerator outer box 13 and the refrigerator inner box 14 after the above-described vacuum heat insulating material according to the present invention is attached to the refrigerator outer box 13 or the refrigerator inner box 14. The urethane foam resin 15 can be injected into the gap formed between the two. The refrigerator door 16 can be produced in the same manner as the refrigerator box. The refrigerator 12 can be completed using the produced refrigerator box and parts such as the refrigerator door 16, the compressor 17, the heat exchanger, and electrical equipment. Since the refrigerator 12 using the vacuum heat insulating material according to the present invention can suppress the intrusion of outside air into the vacuum heat insulating material over a long period of time, it suppresses the increase in thermal conductivity over a long period of time and reduces the power consumption of the device. It can be kept low.

  Hot water (not shown) warmed by the heat pump unit 21 is stored in the hot water storage tank 19 of the heat pump water heater 18 shown in FIG. When hot water is not used, when the hot water temperature in the tank is lowered, it is necessary to re-boil, so that the coefficient of performance (COP: Coefficient of Performance) of the water heater is lowered. As shown in FIG. 6, if the vacuum heat insulating material 1 according to the present invention is provided on the side surface of the hot water storage tank 19, an increase in thermal conductivity can be suppressed over a long period of time. The decrease can be suppressed, and the power consumption of the device can be suppressed low.

  The vacuum heat insulating material 1 according to the present invention is suitable not only for the refrigerator 12 and the heat pump water heater 18 described above, but also for vending machines and commercial showcases.

[Method of manufacturing vacuum insulation]
FIG. 9 is a flowchart showing an example of a method for manufacturing a vacuum heat insulating material according to the present invention. As shown in FIG. 9, the manufacturing method of the vacuum heat insulating material according to the present invention includes a step (S1) of producing a pair of laminated films 10a and 10b constituting the outer packaging material 3, and a produced pair of laminated films 10a and 10b. The step (S2) of disposing the core material 2 on the inside of the pair, and bonding (thermal fusion) of the respective heat-welded layers (8a, 8b) of the pair of laminated films 10a, 10b at the ends of the pair of laminated films 10a, 10b (Step S3).

  In S1, the surface protective layer 5a (5b), the protective layer 6a (6b), and the heat-welded layer 8a (8b) constituting the laminated film 10a (10b) are overlapped and joined by dry sealing or the like to be laminated film 10a (10b). ) Can be produced.

  FIG. 7 is a schematic cross-sectional view showing an example of a laminator (heat sealer) used in the method for manufacturing a vacuum heat insulating material according to the present invention, and FIG. 8 is an enlarged view of a portion C in FIG. Joining (thermal welding) of the heat welding layers (8a, 8b) is performed using the apparatus shown in FIGS.

  As the heat sealer, a bar type that can be sealed for each piece, a continuous sealer, or the like can be used. The heat sealer 70 shown in FIGS. 7 and 8 is of a bar type having an upper seal bar 77 and a lower seal bar 78.

  The angle α of the vacuum heat insulating material according to the present invention can be adjusted by the inclination angle of the seal bars 77 and 78.

  As the vacuum heat insulating material in the present disclosure, an outer packaging material in which a core material having glass fibers and a portion welded by heat are inclined and thinned in an outer peripheral direction can be used. As a result, gas intrusion from the end face of the weld layer is reduced, and the change in thermal conductivity over time can be reduced by suppressing the pressure rise inside the vacuum heat insulating material.

  Hereinafter, the present invention will be described in more detail based on examples.

(1.1) Production of vacuum heat insulating material of Example 1 A vacuum heat insulating material having the configuration shown in FIG. 1 was produced. As the core material 2, a glass fiber aggregate (fiber aggregate) was used. This is a glass wool sheet in which glass wool fibers having an average fiber diameter of 5.0 μm obtained by melting and spinning soda lime glass by a centrifugal method are accumulated on a conveyor having a suction function. The basis weight of the glass wool sheet (weight per 1 m ^{2 of} sheet-like glass wool) is 1500 g / m ² per sheet, and three sheets were used in this embodiment. Moreover, the core material 2 was cut into a size of 300 mm × 300 mm before use and dried in a drying furnace at a temperature of 200 ° C. for 30 minutes.

The outer packaging material 3 is a polyethylene terephthalate film (thickness 12 × 10 ⁻⁶ m) with a polyamide film (thickness 25 × 10 ⁻⁶ m) as the surface protective layers 5 a and 5 b and an aluminum vapor deposition layer added as the protective layers 6 a and 6 b. As the gas barrier layers 7a and 7b, an aluminum-deposited ethylene-vinyl alcohol copolymer (thickness 15 × 10 ⁻⁶ m) was used. Further, a linear low density polyethylene film (thickness 50 × 10 ⁻⁶ m) is used as the heat welding layers 8a and 8b, and the surface protective layers 5a and 5b, the protective layers 6a and 6b, the gas barrier layers 7a and 7b, and the heat The welding layers 8a and 8b were laminated by a dry lamination method to produce a laminated film (10a and 10b) having a four-layer structure.

  The produced outer packaging material 3 is cut into 380 × 450 mm, stacked so that the heat-welded layers 8a and 8b are in contact with each other, the end of the three sides is set to a width of 10 mm of the heat-welded portion 4, and a heat sealer having an inclined structure. Heat-welded and heat-welded. When the cross section of the produced heat welding part 4 was observed with the electron microscope, the heat welding layers 8a and 8b had the structure shown in FIG. 2, and the angle (alpha) was 0.6 degrees.

  As the adsorbent 11, synthetic zeolite (weight: 5 g) was used. The core material 2 from which moisture was removed by drying and the adsorbent 11 were put together in a bag-like outer packaging material 3, and then set in a vacuum chamber and subjected to a vacuum operation. The depressurization operation was performed for 5 minutes with an oil rotary pump, and then for 5 minutes with an oil diffusion pump. After the decompression operation was completed, the opening (one side that was not heat-sealed) was adhered and sealed by thermal welding. The shape of the heat welded portion was the same as the other three sides. The structure of the heat weld layer of Example 1 is described in Table 1 described later.

(1.2) Evaluation of thermal conductivity of vacuum heat insulating material of Example 1 The thickness of the manufactured vacuum heat insulating material 1 was 18 mm. The heat conductivity (initial value) of the produced vacuum heat insulating material 1 was measured at an average temperature of 10 ° C. using an auto lambda manufactured by Eihiro Seiki Co., Ltd. As a result, it was 1.89 mW / m · K. Furthermore, the produced vacuum heat insulating material was subjected to a heating test for 30 days at 70 ° C. in order to evaluate the change in thermal conductivity over time. As a result, the thermal conductivity after the heating test was 3.01 mW / m · K, and the change rate of thermal conductivity was 59 by dividing the change in thermal conductivity by the initial value and multiplying by 100. The evaluation results of the thermal conductivity of the vacuum heat insulating material of Example 1 are also shown in Table 1 described later.

(1.3) Production and evaluation of equipment provided with vacuum heat insulating material of Example 1 The refrigerator shown in FIG. 5 was produced using the vacuum heat insulating material of Example 1, and the power consumption was measured. Compared to the case where no vacuum heat insulating material was used, the temperature was reduced by about 40%. From this, it became clear that the power consumption of the equipment can be kept low by using the vacuum heat insulating material of the present embodiment.

(2.1) Production of vacuum heat insulating material of Example 2 The vacuum heat insulating material of Example 2 is the same as that of Example 1 for the surface protective layers 5a and 5b, protective layers 6a and 6b, and gas barrier layers 7a and 7b of the outer packaging material 3. It is the same. In Example 2, a high-density polyethylene film (thickness 75 × 10 ⁻⁶ m) was used as the heat-welded layers 8a and 8b, and the width of the heat-welded portion was 7 mm. When a laminated film (10a, 10b) was produced in the same manner as in Example 1 and the cross section was observed with a microscope, the angle α was 1.2 °. The structure of the heat-welded layer of Example 2 is also shown in Table 1 described later.

(2.2) Evaluation of thermal conductivity of vacuum heat insulating material of Example 2 The thickness of the manufactured vacuum heat insulating material 1 was 18 mm. When the thermal conductivity (initial value) of the manufactured vacuum heat insulating material 1 and the thermal conductivity and change rate after the acceleration test were evaluated using the same apparatus and conditions as in Example 1, the thermal conductivity (initial value) ) Showed a thermal conductivity of 2.75 mW / m · K after a 1.79 mW / m · K heating test, and a thermal change rate of 54. The evaluation results of the thermal conductivity of the vacuum heat insulating material of Example 2 are also shown in Table 1 described later.

(2.3) Production and Evaluation of Equipment Comprising Vacuum Insulating Material of Example 2 A heat pump water heater 18 shown in FIG. 6 was produced using a plurality of the vacuum insulating materials 1 of Example 2. About 10% improvement in COP was confirmed when the vacuum heat insulating material of the present Example was applied. From this, it became clear that the power consumption of the equipment can be kept low by using the vacuum heat insulating material of the present embodiment.

(3.1) Production of vacuum heat insulating material of Example 3 The vacuum heat insulating material of Example 3 is the same as that of Example 1 for the surface protective layers 5a, 5b, protective layers 6a, 6b and gas barrier layers 7a, 7b of the outer packaging material 3. And 2. In Example 3, a linear low density polyethylene film (thickness 50 × 10 ⁻⁶ m) was used as the heat welding layers 8a and 8b, and the width of the heat welding portion was 20 mm. When a laminated film (10a, 10b) was produced in the same manner as in Example 1 and the cross section was observed with a microscope, the angle α was 0.3 °. The configuration of the heat-welded layer of Example 3 is also shown in Table 1 described later.

(3.2) Evaluation of thermal conductivity of vacuum heat insulating material of Example 3 The thickness of the manufactured vacuum heat insulating material 1 was 18 mm. When the thermal conductivity (initial value) of the manufactured vacuum heat insulating material 1 and the thermal conductivity and change rate after the acceleration test were evaluated using the same apparatus and conditions as in Example 1, the thermal conductivity (initial value) ) Was 1.83 mW / m · K, the thermal conductivity after the heating test was 2.8 mW / m · K, and the rate of change was 53. The evaluation results of the thermal conductivity of the vacuum heat insulating material of Example 3 are also shown in Table 1 described later.

(4.1) Production of vacuum heat insulating material of Example 4 The vacuum heat insulating material of Example 4 is the same as that of Example 1 for the surface protective layers 5a, 5b, protective layers 6a, 6b and gas barrier layers 7a, 7b of the outer packaging material 3. Same as ~ 3. In Example 4, a linear low density polyethylene film (thickness 100 × 10 ⁻⁶ m) was used as the heat welding layers 8a and 8b, and the width of the heat welding portion was 7 mm. When the laminated films (10a, 10b) were produced in the same manner as in Example 1 and the cross section was observed with a microscope, the heat-welded layer was inclined toward the outer periphery, and the angle α was 1.6 °. . The structure of the heat-welded layer of Example 4 is also shown in Table 1 described later.

(4.2) Evaluation of thermal conductivity of vacuum heat insulating material of Example 4 The thickness of the manufactured vacuum heat insulating material 1 was 18 mm. When the thermal conductivity (initial value) of the manufactured vacuum heat insulating material 1 and the thermal conductivity and change rate after the acceleration test were evaluated using the same apparatus and conditions as in Example 1, the thermal conductivity (initial value) ) Was 1.83 mW / m · K, the thermal conductivity after the heating test was 2.92 mW / m · K, and the rate of change was 60. The evaluation results of the thermal conductivity of the vacuum heat insulating material of Example 4 are also shown in Table 1 described later.

(5.1) Production of Vacuum Heat Insulating Material of Comparative Example 1 As shown in FIG. 4, the outer surfaces 80a ′ and 80b ′ of the heat-welded layers 8a ′ and 8b ′ are not provided with the angle α in the heat-welded portion 4 ′. The laminated films 10a ′ and 10b ′ of Comparative Example 1 were produced in the same manner as in Example 1 except that the bonding surface 81 ′ and the bonding surface 81 ′ were parallel to each other.

(5.2) Evaluation of thermal conductivity of vacuum heat insulating material of Comparative Example 1 The thickness of the manufactured vacuum heat insulating material 1 was 18 mm. When the thermal conductivity (initial value) of the manufactured vacuum heat insulating material 1 ′, the thermal conductivity and the change rate after the acceleration test were evaluated using the same apparatus and conditions as in Example 1, the thermal conductivity (initial value) Value) was 1.83 mW / m · K, the thermal conductivity after the heating test was 3.9 mW / m · K, and the rate of change was 113, which was significantly higher than that of Example 1. This is considered to be because the area where the heat-welded layer is in contact with the outside air is increased and the amount of gas permeation is increased.

(6.1) Production of Vacuum Insulating Material of Comparative Example 2 As shown in FIG. 4, the outer surfaces 80 a ′ and 80 b ′ of the heat welding layers 8 a ′ and 8 b ′ in the heat welding part 4 ′ are not provided with the angle α. The laminated films 10a ′ and 10b ′ of Comparative Example 2 were produced in the same manner as in Example 2 except that the bonding surface 81 ′ and the bonding surface 81 ′ were parallel to each other.

(6.2) Evaluation of thermal conductivity of vacuum heat insulating material of Comparative Example 2 The thickness of the manufactured vacuum heat insulating material 1 was 18 mm. When the thermal conductivity (initial value) of the manufactured vacuum heat insulating material 1 ′, the thermal conductivity and the change rate after the acceleration test were evaluated using the same apparatus and conditions as in Example 1, the thermal conductivity (initial value) Value) was 1.85 mW / m · K, the thermal conductivity after the heating test was 3.78 mW / m · K, and the rate of change was 104, which was significantly higher than that of Example 2. This is considered to be because the area where the heat-welded layer is in contact with the outside air is increased and the amount of gas permeation is increased.

  As described above, according to the present invention, a vacuum heat insulating material capable of preventing gas from entering the outer packaging material and preventing deterioration of heat insulating properties over a long period of time, and an apparatus equipped with the same A manufacturing method of a vacuum heat insulating material can be provided.

  In addition, this invention is not limited to an above-described Example, Various modifications are included. For example, the above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described. Further, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Further, it is possible to add, delete, and replace other configurations for a part of the configuration of each embodiment.

  DESCRIPTION OF SYMBOLS 1,1 '... Vacuum heat insulating material, 2 ... Core material, 3, 3' ... Outer packaging material, 4, 4 '... Thermal welding part (joining part), 5a, 5b, 5a', 5b '... 1st layer (surface Protective layer), 6a, 6b, 6a ', 6b' ... Second layer (protective layer), 7a, 7b, 7a ', 7b' ... Third layer (gas barrier layer), 8a, 8b, 8a ', 8b' ... Thermal welding layer, 80a, 80b, 80a ', 80b' ... outer surface of the thermal welding layer, 81, 81 '... bonding surface, 82, 82a', 82b '... end face of the thermal welding layer, 10a, 10b, 10a' , 10b '... laminated film, 11 ... adsorbent (getter agent), 12 ... refrigerator, 13 ... refrigerator outer box, 14 ... refrigerator inner box, 15 ... foamed urethane resin, 16 ... refrigerator door, 17 ... compressor, 18 ... heat pump Water heater, 19 ... Hot water storage tank, 20 ... Hot water storage tank unit, 21 ... Heat pump unit, 70 ... Toshira, 71 ... support platform, 72 ... base, 73 ... arm, 74 ... body, 76 ... stopper, 77 ... upper seal bar, 78 ... lower seal bar 79 ... upper heater, 80 ... lower heater.

Claims (7)

A core material, and an outer packaging material made of a pair of laminated films provided facing each other with the core material interposed therebetween,
The laminated film is a product in which a surface protective layer, a protective layer, a gas barrier layer, and a heat welding layer are laminated in this order from the outside,
At the end portions of the pair of laminated films, the thermal welding layers of the pair of laminated films are bonded to each other,
A vacuum heat insulating material characterized in that an angle α formed between a bonding surface of each of the pair of laminated films and the outer surface of each of the pair of laminated films is an acute angle. .   The vacuum heat insulating material according to claim 1, wherein α is 3 ° or less.   The vacuum heat insulating material according to claim 1 or 2, wherein a width of the joint surface is 7 to 20 mm. 3. The vacuum heat insulating material according to claim 1, wherein a thickness of a portion other than a bonding surface of the heat welding layer is 30 × 10 ⁻⁶ m or more. A core material, and an outer packaging material made of a pair of laminated films provided facing each other with the core material interposed therebetween,
The laminated film is a product in which a surface protective layer, a protective layer, a gas barrier layer, and a heat welding layer are laminated in this order from the outside,
At the end portions of the pair of laminated films, the thermal welding layers of the pair of laminated films are bonded to each other,
A vacuum heat insulating material characterized in that an angle α formed between a bonding surface of each of the pair of laminated films and the outer surface of each of the pair of laminated films is an acute angle. With equipment.   6. The device according to claim 5, wherein the device is a refrigerator or a heat pump water heater. A core material, and an outer packaging material made of a pair of laminated films provided opposite to each other with the core material interposed therebetween, the laminated film including a surface protective layer, a protective layer, a gas barrier layer, and heat welding in order from the outside. A method for producing a vacuum heat insulating material in which layers are laminated in this order,
Producing the pair of laminated films;
Arranging the core material inside the pair of laminated films, and joining the respective heat-welded layers of the pair of laminated films at the ends of the pair of laminated films,
In the step of bonding the thermal welding layers of the pair of laminated films, the bonding surfaces of the thermal welding layers of the pair of laminated films and the outer sides of the thermal welding layers of the pair of laminated films, respectively. A method for manufacturing a vacuum heat insulating material, characterized in that the heat-welded layer of the pair of laminated films is heat-welded so that an angle α formed with the surface is an acute angle.

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