JP2016173145A - Vacuum heat insulation panel, core material, and refrigerator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress a decline in the degree of vacuum even when a core material is constituted of a resin fiber.SOLUTION: A vacuum heat insulation panel includes: a core material comprising the resin fiber; and a low-molecular adsorbent added to the core material to adsorb a low molecule derived from the resin fiber.SELECTED DRAWING: Figure 1

Description

  Embodiments of the present invention relate to a vacuum heat insulation panel, a core material constituting the vacuum heat insulation panel, and a refrigerator including the vacuum heat insulation panel.

  For example, it is considered to use a vacuum heat insulating panel as a heat insulating material in various devices and facilities such as a refrigerator. This type of vacuum heat insulation panel has a problem that gas is generated after the inside is depressurized. For example, Patent Document 1 discloses that most of the total gas amount after decompression is moisture, and discloses that an adsorbent that adsorbs such gas and water vapor is provided. By the way, in recent years, it is considered that the core material of the vacuum heat insulation panel is made of resin fibers. When such resin fibers are provided, low molecules are generated from the resin fibers after decompression. Therefore, only the adsorbent that adsorbs moisture cannot cope with such low-molecular-weight resin fibers. Therefore, there is a possibility that the degree of vacuum of the vacuum heat insulating panel is impaired.

JP 2010-53980 A

  This embodiment is a vacuum heat insulation panel that can suppress a decrease in the degree of vacuum even when the core material is made of resin fibers, the core material that constitutes this vacuum heat insulation panel, and a refrigerator that includes this vacuum heat insulation panel I will provide a.

  The vacuum heat insulation panel according to the present embodiment includes a core material made of resin fibers and a low molecular weight adsorbent that is added to the core material and adsorbs low molecules derived from the resin fibers.

The schematic diagram which shows the core material and nonwoven fabric of the vacuum heat insulation panel by embodiment Typical sectional drawing which shows the vacuum heat insulation panel by embodiment It is a schematic diagram which shows the core material of the vacuum heat insulation panel by embodiment, Comprising: (A) is a disassembled perspective view, (B) is the schematic which shows a side view The schematic diagram which shows the side view of the core material of the vacuum heat insulation panel by embodiment The figure which shows the state where the low molecular weight adsorbent and the moisture adsorbent are added to the core material The typical perspective view showing the heat insulation box of the refrigerator by an embodiment The typical perspective view which shows the vacuum heat insulation panel group of the refrigerator by embodiment

  Hereinafter, an embodiment will be described with reference to the drawings. As shown in FIG. 1, the core material 10 has a nonwoven fabric 11 laminated in a plurality of layers. The nonwoven fabric 11 is formed of resin fibers 12 that are randomly intertwined. The resin fiber 12 is formed by an electrospinning method. The resin fibers 12 formed by the electrospinning method are fine fibers having an average fiber diameter of about 1 μm, and are long fibers whose length is 1000 times or more of the outer diameter. Further, the resin fiber 12 is not linear as a whole, but is a curved shape that is randomly curved. Therefore, the resin fibers 12 are easily entangled with each other, and a plurality of layers are easily formed. By utilizing the electrospinning method, the spinning of the resin fibers 12 and the formation of the nonwoven fabric 11 can be performed simultaneously. As a result, the core material 10 can be easily formed with a short man-hour.

  Moreover, the resin fiber 12 which comprises the nonwoven fabric 11 can ensure an ultra-thin outer diameter of nanometer to micrometer easily by utilizing the electrospinning method. Therefore, the nonwoven fabric 11 has a very thin thickness per sheet, and the core material 10 also has a small thickness. In the case of a conventional glass fiber, the fiber length is short and the fibers are less entangled. Therefore, when glass fiber is used, it becomes difficult to maintain the shape of the nonwoven fabric. In the case of glass fiber, it is generally difficult to simultaneously spin glass fiber and form a nonwoven fabric. When using the conventional glass fiber, the nonwoven fabric is formed in the manner of a paper basket with the glass fiber dispersed in water. If the spinning of the glass fiber and the formation of the nonwoven fabric are performed simultaneously, a cotton-like nonwoven fabric having a large thickness is formed, and it is difficult to form a thin nonwoven fabric having a small thickness.

  Thus, in the case of this embodiment, the core material 10 is formed with the nonwoven fabric 11 which consists of the laminated | stacked several layer. The core material 10 is formed by laminating, for example, several hundred to several thousand nonwoven fabrics 11. The resin fibers 12 forming the nonwoven fabric 11 of the present embodiment are formed in a circular or elliptical shape with a substantially uniform cross section.

  The resin fibers 12 forming the nonwoven fabric 11 are formed of an organic polymer having a density lower than that of glass. By forming the resin fiber 12 with a polymer having a density lower than that of glass, the resin fiber 12 can be reduced in weight. The nonwoven fabric 11 may be a mixture of two or more types of resin fibers 12. As an example of the nonwoven fabric 11 formed by blending, polystyrene fiber and aromatic polyamide resin (registered trademark: Kepler) are used. In addition to the above, the non-woven fabric 11 includes polycarbonate, polymethyl methacrylate, polypropylene, polyethylene, polyethylene terephthalate, polybutylene terephthalate, polyamide, polyoxymethylene, polyamideimide, polyimide, polysulfane, polyethersulfane, poly 1 selected from ether imide, polyether ether ketone, polyphenylene sulfide, modified polyphenylene ether, syndiotactic polystyrene, liquid crystal polymer, urea resin, unsaturated polyester, polyphenol, melamine resin, epoxy resin and copolymers containing these. It can be formed by blending two or more kinds of polymers.

  When the resin fiber 12 is formed by an electrospinning method, the polymer is made into a solution. Examples of the solvent include isopropanol, ethylene glycol, cyclohexanone, dimethylformamide, acetone, ethyl acetate, dimethylacetamide, N-methyl-2-pyrrolidone, hexane, toluene, xylene, methyl ethyl ketone, diethyl ketone, butyl acetate, tetrahydrofuran, dioxane, A volatile organic solvent such as pyridine or water can be used. Further, the solvent may be one kind selected from the above solvents, or a plurality of kinds may be mixed. In addition, the solvent applicable to this embodiment is not limited to the said solvent. The said solvent is an illustration to the last.

  In this case, the resin fibers 12 to be blended are all set so that the outer diameter d is d <1 μm. As described above, by blending a plurality of types of resin fibers 12, it is possible to improve the heat insulation, weight reduction, and strength of the nonwoven fabric 11. On the contrary, when the volume of voids formed between the intertwined resin fibers 12 is reduced in the nonwoven fabric 11, the number of the voids is increased. As the number of voids between the resin fibers 12 increases, the heat insulation is improved. Therefore, it is preferable that the nonwoven fabric 11 has a fiber outer diameter d of the resin fiber 12 constituting the same is reduced to a nanometer order of d <1 μm. By reducing the outer diameter d of the resin fibers 12 in this way, the number of voids formed between the resin fibers 12 is reduced and the number is increased. By reducing the diameter in this way, the volume of voids formed between the intertwined resin fibers 12 becomes smaller and the number thereof increases, and the heat insulating property of the nonwoven fabric 11 is improved.

  For example, various inorganic fillers such as silicon oxide, metal hydroxide, carbonate, sulfate, and silicate may be added to the resin fiber 12. Thus, by adding an inorganic filler to the resin fiber 12, the strength can be improved while maintaining the heat insulating property of the nonwoven fabric 11. Specifically, as the inorganic filler to be added, wollastonite, potassium titanate, zonotlite, gypsum fiber, aluminum porate, MOS (basic magnesium sulfate), aramid fiber, carbon fiber, glass fiber, talc, mica, glass flake Etc. can also be used.

  The core material 10 formed of the nonwoven fabric 11 is accommodated in a bag-shaped outer packaging material 13 as shown in FIG. The outer packaging material 13 is made of an airtight sheet material in which gas permeability is eliminated by evaporating a metal or metal oxide on, for example, one or more resin films. The outer packaging material 13 containing the core material 10 is sealed together with the core material 10 after reducing the inside to a pressure close to vacuum. Thereby, the outer packaging material 13 containing the core material 10 is formed as the vacuum heat insulation panel 14. In this case, the vacuum heat insulation panel 14 may accommodate a skeleton member serving as a skeleton inside the outer packaging material 13 in order to reduce crushing of the formed vacuum heat insulation panel 14.

  The core material 10 may be provided with an aluminum foil 15 on one surface side laminated as shown in FIG. The core material 10 formed of the nonwoven fabric 11 as described above is formed as the vacuum heat insulation panel 14 by reducing the pressure inside the outer packaging material 13 after being accommodated in the outer packaging material 13. Therefore, the vacuum heat insulating panel 14 may be crushed or deformed by the reduced pressure inside the outer packaging material 13. By providing the aluminum foil 15 on one surface side of the nonwoven fabric 11, the strength of the core material 10 is improved. Thereby, the crushing and deformation | transformation by pressure reduction can be reduced. Moreover, the core material 10 may be provided with the glass fiber layer 16 laminated | stacked with the nonwoven fabric 11, as shown in FIG. The glass fiber layer 16 has higher strength than the nonwoven fabric 11 formed of fine resin fibers 12. Therefore, by laminating the nonwoven fabric 11 and the glass fiber layer 16, although the thickness and weight are increased as compared with the case where the core material 10 is formed only by the nonwoven fabric 11, crushing and deformation due to reduced pressure can be reduced. The glass fiber layer 16 is not limited to the two layers shown in FIG. 4 and may be one layer or three or more layers.

  And as shown in FIG. 5, the low molecular adsorbent 100 and the moisture adsorbent 200 are added to the core material 10 of the vacuum heat insulation panel 14 which concerns on this embodiment. In this case, the low-molecular adsorbent 100 and the moisture adsorbent 200 are scattered between the nonwoven fabrics 11 made of the resin fibers 12. The low molecular adsorbent 100 adsorbs low molecules generated from the resin fibers 12. In this case, the low molecular weight adsorbent 100 is made of synthetic zeolite and physically adsorbs low molecules. The adsorption action by such a physical adsorption method is reversible, and the low molecules adsorbed on the low molecular adsorbent 100 are easily separated from the low molecular adsorbent 100 by applying a certain amount of heat, for example. The low molecular adsorbent 100 is not limited to zeolite. On the other hand, the moisture adsorbing material 200 adsorbs moisture. In this case, the moisture adsorbing material 200 is made of calcium oxide and chemically adsorbs moisture. The adsorption action by such a chemical adsorption method is irreversible, and the moisture adsorbed on the moisture adsorbing material 200 is unlikely to be separated from the moisture adsorbing material 200 when a certain amount of heat is applied. The moisture adsorbing material 200 is not limited to calcium oxide.

  In particular, after the inside of the outer packaging material 13 containing the core material 10 is decompressed, low molecules are likely to be generated from the resin fibers 12. According to the vacuum thermal insulation panel 14 according to the present embodiment, such low molecules derived from the resin fibers 12 are adsorbed by the low molecular adsorbent 100. Therefore, even when the core material 10 is composed of the resin fibers 12, it is possible to suppress a decrease in the degree of vacuum in the vacuum heat insulating panel 14. Furthermore, according to the vacuum heat insulating panel 14, the moisture inside the moisture adsorbing material 200 is also adsorbed. Accordingly, it is possible to further suppress a decrease in the degree of vacuum in the vacuum heat insulating panel 14.

  In particular, after the inside of the outer packaging material 13 containing the core material 10 is decompressed, low molecules are likely to be generated from the resin film constituting the outer packaging material 13. According to the vacuum heat insulation panel 14, the low molecule derived from the outer packaging material 13 is also adsorbed by the low molecular adsorbent 100. Accordingly, it is possible to suppress a decrease in the degree of vacuum in the vacuum heat insulating panel 14.

  In this case, the addition amount of the low molecular weight adsorbent 100 is larger than the addition amount of the moisture adsorbent 200. That is, the core material 10 according to the present embodiment is entirely or almost entirely made of resin fibers 12. Therefore, the amount of low molecules derived from the resin fibers 12 tends to increase. Therefore, more low molecules derived from the resin fibers 12 can be adsorbed by increasing the amount of the low molecular adsorbent 100 added. The addition amount of the low molecular adsorbent 100 and the addition amount of the moisture adsorbent 200 can be adjusted as appropriate. For example, the addition amount of both may be the same or the addition of the low molecular adsorbent 100 The amount may be smaller than the amount of moisture adsorbent 200 added.

  The resin fiber 12 may be formed by, for example, a melt spinning method. The melt spinning method is a manufacturing method in which a resin fiber 12 is obtained by heating and melting a raw material of the resin fiber 12 and then extruding it from a nozzle into air or water and cooling it.

Next, a refrigerator using the vacuum heat insulation panel 14 will be described with reference to FIGS. 6 and 7.
As shown in FIG. 6, the refrigerator 40 includes a heat insulating box 41 having an open front surface. In the refrigerator 40, a refrigeration cycle (not shown) is attached to the heat insulating box 41. The refrigerator 40 also includes a partition plate (not shown) that partitions the heat insulation box 41 into a plurality of storage rooms, a heat insulation door (not shown) that covers the front of the storage room, and a drawer (not shown) that moves back and forth inside the storage room. Yes. The heat insulating box 41 of the refrigerator 40 includes an outer box 42, an inner box 43, and a vacuum heat insulating panel set 50 sandwiched between the outer box 42 and the inner box 43. The outer box 42 is formed of a steel plate, and the inner box 43 is formed of a synthetic resin.

  The vacuum heat insulation panel set 50 is divided corresponding to each wall portion of the heat insulation box 41 of the refrigerator 40. Specifically, the vacuum heat insulating panel set 50 is divided into a left wall panel 51, a right wall panel 52, a ceiling panel 53, a rear wall panel 54, and a bottom wall panel 55 as shown in FIG. The left wall panel 51, the right wall panel 52, the ceiling panel 53, the rear wall panel 54, and the bottom wall panel 55 are all configured by the vacuum heat insulating panel 14 described above. The left wall panel 51, the right wall panel 52, the ceiling panel 53, the rear wall panel 54 and the bottom wall panel 55 are assembled as a vacuum heat insulating panel set 50 and sandwiched between the outer box 42 and the inner box 43. A gap formed between the left wall panel 51, the right wall panel 52, the ceiling panel 53, the rear wall panel 54, and the bottom wall panel 55 constituting the vacuum heat insulation panel set 50 between the outer box 42 and the inner box 43. Is sealed with a heat insulating seal member (not shown). The seal member is formed of, for example, a foamable resin.

  Thus, the refrigerator 40 has the vacuum heat insulation panel set 50 which comprises the heat insulation box 41. FIG. The vacuum heat insulation panel set 50 is configured by the vacuum heat insulation panel 14 described above. Therefore, high heat insulation performance can be secured while further reducing the thickness and weight.

  Moreover, when applying the vacuum heat insulation panel 14 to the refrigerator 40, the low molecular weight adsorbent 100 is good to make the addition amount inside the warehouse of the vacuum insulation panel 14 larger than the addition amount outside the warehouse of the vacuum insulation panel 14. . That is, the vacuum heat insulation panel 14 tends to be colder at the inner side than at the outer side. As described above, the adsorption action by the low molecular adsorbent 100 is reversible. Therefore, by increasing the number of low-molecule adsorbents 100 existing inside the thermally stable warehouse, it is possible to suppress the low-molecules once adsorbed from being released again.

  The vacuum heat insulation panel according to the present embodiment includes a core material made of resin fibers and a low molecular weight adsorbent that is added to the core material and adsorbs low molecules derived from the resin fibers. According to this configuration, since low molecules generated from the resin fibers 12 are adsorbed without being released into the vacuum heat insulation panel 14, the degree of vacuum is reduced even when the core material 10 is configured by the resin fibers 12. Can be suppressed.

  This embodiment is presented as an example and is not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. This embodiment and its modifications are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  In the drawings, 10 is a core material, 12 is a resin fiber, 14 is a vacuum heat insulation panel, 40 is a refrigerator, 100 is a low molecular weight adsorbent, and 200 is a moisture adsorbent.

Claims (11)

A core material made of resin fibers;
A low molecular weight adsorbent that is added to the core material and adsorbs the low molecular weight derived from the resin fiber;
Vacuum insulation panel comprising.   The vacuum heat insulating panel according to claim 1, wherein the low molecular weight adsorbent is zeolite. A water adsorbent that is added to the core material and adsorbs moisture;
The vacuum heat insulation panel according to claim 1 or 2 which made the addition amount of said low molecular adsorption material larger than the addition amount of said moisture adsorption material.   The vacuum thermal insulation panel according to any one of claims 1 to 3, wherein an adsorption method of the low molecular weight adsorbent is different from an adsorption method of the moisture adsorbent.   The vacuum insulation panel according to any one of claims 1 to 4, wherein the resin fiber is made of polystyrene.   The vacuum heat insulation panel according to any one of claims 1 to 5, wherein an average fiber diameter of the resin fibers is smaller than 1 µm.   The vacuum insulation panel according to any one of claims 1 to 6, wherein the resin fiber is formed by an electrospinning method.   The vacuum heat insulation panel according to any one of claims 1 to 6, wherein the resin fiber is formed by a melt spinning method.   The core material with which the vacuum heat insulation panel of any one of Claim 1 to 8 is equipped.   A refrigerator provided with the vacuum heat insulation panel of any one of Claim 1 to 8.   The refrigerator according to claim 10, wherein the low molecular weight adsorbent is added more to the inner side than the outer side of the vacuum heat insulating panel.

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