JP4334525B2 - refrigerator - Google Patents

Description

  The present invention relates to a refrigerator having a vacuum heat insulating material in which the inside of an outer packaging material covering a core material is maintained in a vacuum.

  The refrigerator has a main body part that forms a storage chamber, and a heat insulating wall of the main body part is filled with a foam heat insulating material. A vacuum heat insulating material is disposed on the heat insulating wall in contact with the foam heat insulating material. A conventional vacuum heat insulating material is disclosed in Patent Document 1. This vacuum heat insulating material encloses a core material such as glass fiber with a bag-like outer packaging material, and the inside of the outer packaging material is maintained in a vacuum by using the core material as a spacer. Thereby, a vacuum heat insulating material has a heat insulation effect. The vacuum heat insulating material is widely used with a foam heat insulating material inside a heat insulating wall of a refrigerator.

  The outer packaging material has first and second laminated films in which a plurality of film-like members such as a polyamide film, an aluminum-deposited polyester, and a high-density polyethylene film are laminated. The outer packaging material is formed in a bag shape by sticking both ends of the first and second laminated films.

  The high-density polyethylene film is a sealant layer that is disposed in the innermost layer and adheres the end portions of the first and second laminate films by heat welding. Two layers of polyester subjected to aluminum vapor deposition are laminated to form a gas barrier layer that shields water vapor and carbon dioxide. The polyamide film is a protective layer that is disposed on the outermost layer to protect the surface.

Rigid polyurethane foam obtained by reacting isocyanate with polyol using cyclopentane and water as a mixed foaming agent is widely used as the foam insulation. Since isocyanate reacts with water to generate carbon dioxide, entry of water vapor and carbon dioxide into the outer packaging material is prevented by the gas barrier layer. Thereby, the inside of a vacuum heat insulating material can be insulated by maintaining a high vacuum.
Japanese Patent Laying-Open No. 2005-106312 (pages 4-8, FIG. 2)

  However, according to the above conventional refrigerator, the aluminum vapor deposition film provided on the gas barrier layer of the vacuum heat insulating material is formed of crystal grains, and there is a gap between the crystal grains. Thereby, the gas etc. which generate | occur | produce at the time of foaming of a foaming heat insulating material penetrate | invade into an outer packaging material gradually via a vapor deposition film and polyester with progress of a period. For this reason, there has been a problem that the degree of vacuum of the vacuum heat insulating material changes with time and the heat insulating effect decreases.

  An object of this invention is to provide the refrigerator which can maintain a high heat insulation effect for a long period of time.

In order to achieve the above object, the present invention provides a bag-like outer package in which a front surface of a main body having a storage chamber is opened and closed by an open / close door, and a core material serving as a spacer and the core material are contained and the interior is maintained in a vacuum In the refrigerator in which a vacuum heat insulating material provided with a material is provided on the heat insulating wall of the main body, the outer packaging material has a first laminated film in which a plurality of film-like members are laminated, and the first laminated film is made of ethylene vinyl alcohol. have a first gas barrier layer coated with polychlorinated vinyl resin to the surface subjected to aluminum vapor deposition on a base made of polymer, than the first gas barrier layer having an aluminized on a base composed of polyester The second gas barrier layer having a small thickness is provided adjacent to the first gas barrier layer .

  According to this configuration, the vacuum heat insulating material in which the core material is wrapped with the outer packaging material has a predetermined volume by the core material, and the inside is maintained in a vacuum. The outer packaging material is composed of a first laminated film having a first gas barrier layer, and gas such as carbon dioxide and cyclopentane is shielded by the first gas barrier layer.

Also, a gas such as water vapor is shielded by the second gas barrier layer.

  In the refrigerator having the above-described configuration, the present invention is characterized in that an adsorbent that adsorbs a gas that enters the outer packaging material is disposed on the storage chamber side in the outer packaging material. According to this configuration, the adsorbent is disposed on the low temperature side.

  According to the present invention, in the refrigerator configured as described above, the outer packaging material is formed in a bag shape by closely contacting both ends of the second laminate film in which a plurality of film-like members including aluminum foil are laminated and both ends of the first laminate film. The second laminate film is arranged on the storage chamber side. According to this configuration, the vacuum heat insulating material is covered with the second laminate film having the aluminum foil on the side close to the storage chamber where the adsorbent is disposed, and the first laminate having the first gas barrier layer on the side away from the storage chamber and close to the outer surface. Covered with film.

  According to the present invention, the first laminated film forming the outer packaging material of the vacuum heat insulating material is the first gas barrier layer in which the surface of the base made of an ethylene vinyl alcohol copolymer is subjected to aluminum vapor deposition and coated with the polyvinyl chloride resin. Therefore, the vacuum heat insulating material has a reduced gas permeation amount, and the refrigerator can maintain the heat insulating effect for a long time by the vacuum heat insulating material.

  Further, according to the present invention, since the second gas barrier layer on which aluminum vapor deposition has been performed is provided adjacent to the first gas barrier layer on the base made of polyester, the heat insulating effect of the refrigerator can be maintained longer.

  According to the present invention, since the adsorbent is disposed on the storage chamber side in the outer packaging material, the adsorbent can be maintained at a low temperature to improve the adsorption efficiency.

  Moreover, according to this invention, since the 2nd laminate film which has aluminum foil was arrange | positioned at the storage chamber side, the permeation | transmission amount of gas can be reduced more by aluminum foil. Furthermore, by disposing the second laminate film on the low temperature side, the heat bridge that is transferred from the high temperature side to the adsorbent through the aluminum foil is reduced, and the decrease in the adsorption efficiency of the adsorbent is suppressed. Can do.

  Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 are a side sectional view and a top sectional view showing a refrigerator using a vacuum heat insulating material according to an embodiment. The refrigerator 1 has a main body 2 having an open front surface, and a plurality of storage chambers 4 are provided by dividing the main body 2 vertically. The front surface of each storage chamber 4 is opened and closed by an opening / closing door 3.

  The main body 2 is filled with a foam heat insulating material 7 between an outer box 5 made of an iron plate and an inner box 6 made of a resin molded product. For the foam insulation 7, a rigid polyurethane foam obtained by reacting a polyol with an isocyanate using cyclopentane and water as a mixed foaming agent is used. On the ceiling wall 2a, the back wall 2b, and the side wall 2c of the main body 2, a vacuum heat insulating material 10 fixed to the inner surface side of the outer box 5 is provided.

  FIG. 3 is a side sectional view showing the vacuum heat insulating material 10. The vacuum heat insulating material 10 includes a core material 12 such as glass fiber in a bag-shaped exterior material 11. The outer packaging material 11 is hermetically sealed with the end portion 11a in close contact with the core material 12 as a spacer by evacuation for 5 to 6 minutes to maintain a vacuum. A recess 12a is formed in the core material 12, and an adsorbent 13 that adsorbs gas that has entered the outer packaging material 11 is fitted into the recess 12a. By fitting the adsorbent 13 in the recess 12a, irregularities are not formed on the surface of the core material 12, and breakage of the outer packaging material 11 can be prevented.

  Moreover, the vacuum heat insulating material 10 is arrange | positioned so that the adsorbent 13 may become the storage chamber 4 side. Since the adsorbent 13 has a higher adsorption efficiency at a low temperature, the adsorbent 13 is arranged on the side of the storage chamber 4 where the adsorbent 13 is at a low temperature, thereby suppressing a decrease in the degree of vacuum of the vacuum heat insulating material 10 due to gas entering the outer packaging material 11. be able to.

  FIG. 4 is an enlarged view of a part of FIG. The outer packaging material 11 is formed in a bag shape by closely contacting both ends of the first and second laminated films 21 and 22 in which a plurality of film-like members such as a resin film and a metal foil are laminated. The first and second laminated films 21 and 22 are laminated from the inside in the order of sealant layers 21a and 22a, first gas barrier layers 21b and 22b, second gas barrier layers 21c and 22c, and protective layers 21d and 22d.

  The sealant layers 21a and 22a are made of high density polyethylene (HDPE), and the end portions of the first and second laminate films 21 and 22 are brought into close contact with each other by heat welding. The first gas barrier layer 21b of the first laminate film 21 is formed by coating a surface of a base made of ethylene vinyl alcohol copolymer (EVOH) with aluminum deposition and coating a polyvinyl chloride (PVC) resin. . Thereby, gas, such as a carbon dioxide and cyclopentane, can be shielded.

  The first gas barrier layer 22b of the second laminate film 22 is made of an aluminum foil and shields gases such as water vapor, carbon dioxide, and cyclopentane. The second gas barrier layers 21c and 22c are made of polyester (PET) subjected to aluminum vapor deposition. Thereby, while shielding gas, such as water vapor | steam, the surface of the 1st gas barrier layers 21b and 22b is protected.

  In particular, the ethylene vinyl alcohol copolymer used for the first gas barrier layer 21b of the first laminate film 21 easily absorbs moisture. For this reason, water vapor is shielded by the second gas barrier layer 21c to prevent the vacuum degree in the outer packaging material 11 from being lowered. The protective layers 21d and 22d are made of nylon and are arranged in the outermost layer to protect the surface of the outer packaging material 11.

  In the first gas barrier layer 21b of the first laminate film 21, a vapor deposition film of aluminum is formed of crystal grains, so that a gap is formed between the crystal grains. However, the gap between the crystal grains of the aluminum deposited film is closed by the coating of the polyvinyl chloride resin. Thereby, the first laminate film 21 has a small gas permeability coefficient.

  Table 1 shows the result of measuring the gas permeability coefficient of helium gas of the first laminate film 21 (the value of the SI unit system is also shown for reference). For comparison, the measurement results when the polyvinyl chloride resin coating is not provided on the first gas barrier layer 21b are listed. In any case, the thickness of the sealant layer 21a is 50 μm, the thickness of the first gas barrier layer 21b is 15 μm, the thickness of the second gas barrier layer 21c is 12 μm, and the thickness of the protective layer 21d is 15 μm.

According to Table 1, the gas permeation coefficient without a polyvinyl chloride resin coating is 0.9 cc / (m ² · day · atm) (1.03 × 10 ⁻¹⁴ cm ^{3 in the} SI unit system). / (Cm ² · s · Pa)). The gas permeation coefficient when a polyvinyl chloride resin coating is provided is 0.07 cc / (m ² · day · atm) (0.08 × 10 ⁻¹⁴ cm ³ / (cm ² · in SI unit system). s · Pa)). That is, when the coating of the polyvinyl chloride resin is provided, the gas permeability coefficient is about 1/12 as compared with the case where it is not provided. Therefore, the first laminate film 21 having the first gas barrier layer 21b provided with the coating of the polyvinyl chloride resin has a high gas shielding ability.

  Further, the second laminated film 22 in which the first gas barrier layer 22 b is made of an aluminum foil has a higher gas shielding capability than the first laminated film 21. However, the vacuum heat insulating material 10 is installed so that the side on which the adsorbent 13 is arranged faces the storage chamber side which is the low temperature side, and the other faces the outer surface which is the high temperature side.

  When the second laminated film 22 is disposed facing the high temperature side, a heat bridge is generated in which heat on the high temperature side is transferred from the end of the vacuum heat insulating material 10 to the adsorbent 13 through the aluminum foil, and the adsorbent 13 Adsorption capacity decreases. For this reason, by arrange | positioning the 2nd laminate film 22 to the storage chamber side, the heat transmitted to the adsorbent 13 arrange | positioned facing the low temperature side can be reduced, and the fall of adsorption | suction capability can be suppressed.

  FIG. 5 shows the result of an acceleration test at 70 ° C. of the change in thermal conductivity in the state where the adsorbent 13 is omitted in the vacuum heat insulating material 10. The vertical axis represents thermal conductivity (unit: W / mK), and the horizontal axis represents elapsed days (unit: day). In the figure, A shows the vacuum heat insulating material 10 of this embodiment. Moreover, B, C, and D have shown the result tested about the vacuum heat insulating material which has the 1st laminate film 21 of another structure for the comparison.

  In Comparative Example B, aluminum vapor deposition is performed on a base in which the first gas barrier layer 21b is made of an ethylene vinyl alcohol copolymer, and a coating of polyvinyl chloride resin is not provided on the aluminum vapor deposition surface. In the comparative example C, the first gas barrier layer 21b is formed by coating a polyvinyl chloride resin on the surface on which aluminum is deposited on a base made of polyester. In Comparative Example D, two layers in which a polyvinyl chloride resin is coated are laminated on the surface of the first gas barrier layer 21b made of polyester on which aluminum is deposited.

  In any case, the thickness of the sealant layer 21a is 50 μm, the thickness of the first gas barrier layer 21b is 15 μm (only 30 μm in Comparative Example D), the thickness of the second gas barrier layer 21c is 12 μm, and the thickness of the protective layer 21d is 15 μm. It is.

  According to the figure, the vacuum heat insulating material 10 of this embodiment has the least change in thermal conductivity. Therefore, the heat insulation effect of the vacuum heat insulating material 10 can be maintained high for a long period of time.

  According to the present embodiment, the first laminated film 21 forming the outer packaging material 11 of the vacuum heat insulating material 10 is coated with a polyvinyl chloride resin on the surface on which aluminum is deposited on the base made of an ethylene vinyl alcohol copolymer. Since it has the 1st gas barrier layer 21b, the permeation | transmission amount of the vacuum heat insulating material 10 reduces, and the refrigerator 1 can maintain the heat insulation effect with the vacuum heat insulating material 10 for a long period of time.

  Further, the second laminate film 22 may have the same configuration as the first laminate film 21. Thereby, a heat bridge can be further reduced. Therefore, the heat insulation performance of the vacuum heat insulating material 10 can be improved by further suppressing the adsorption capacity decrease.

  INDUSTRIAL APPLICATION This invention can be utilized for the refrigerator using the vacuum heat insulating material which has a core material in the outer packaging material by which the inside is maintained at a vacuum.

Side surface sectional drawing which shows the refrigerator of embodiment of this invention Top sectional drawing which shows the refrigerator of embodiment of this invention Side surface sectional drawing which shows the vacuum heat insulating material of the refrigerator of embodiment of this invention Side surface sectional drawing to which the principal part of the vacuum heat insulating material of the refrigerator of embodiment of this invention was expanded. The figure which shows the change of the heat conductivity of the vacuum heat insulating material of the refrigerator of embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Refrigerator 2 Main-body part 3 Opening / closing door 4 Storage room 5 Outer box 6 Inner box 7 Foam heat insulating material 10 Vacuum heat insulating material 11 Outer packaging material 12 Core material 12a Recessed part 13 Adsorbent material 21 1st laminated film 22 2nd laminated film 21a, 22a Sealant Layer 21b, 22b First gas barrier layer 21c, 22c Second gas barrier layer 21d, 22d Protective layer

Claims (3)

Opening and closing the front surface of the main body having a storage chamber by an open / close door, and a vacuum heat insulating material including a core material serving as a spacer and a bag-shaped outer packaging material containing the core material and maintaining the interior in a vacuum. In the refrigerator provided on the heat insulating wall of the part,
The outer packaging material has a first laminated film in which a plurality of film-like members are laminated,
The first laminate film have a first gas barrier layer coated with polychlorinated vinyl resin on a surface having been subjected to aluminum vapor deposition on a base of ethylene-vinyl alcohol copolymer,
A refrigerator characterized in that aluminum vapor deposition is performed on a base made of polyester, and a second gas barrier layer having a thickness smaller than that of the first gas barrier layer is provided adjacent to the first gas barrier layer . The refrigerator according to claim 1, wherein an adsorbent that adsorbs a gas that enters the outer packaging material is disposed on the storage chamber side in the outer packaging material . The outer packaging material is formed into a bag shape by sticking both ends of the second laminate film and the both ends of the first laminate film in which a plurality of film-like members including aluminum foil are laminated, and the second laminate film is placed on the storage chamber side. The refrigerator according to claim 2, wherein the refrigerator is arranged .

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