JP2005315346A - Vacuum insulator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vacuum insulator, decreasing heat bridge of a contour member while securing air shut-off performance to attain more excellent thermal insulation performance. <P>SOLUTION: This vacuum insulator is composed of: an outer casing body 12 formed by joining two sheets of contour members 13 made of metal foil 15 at least to form a sealed container and put in the vacuum state by discharging the air in the interior; and a filler 17 stored in the outer casing body 12 and having thermal insulation property. The metal foil 15 is stainless steel foil 15 containing aluminum of 3 to 10 mass %. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a vacuum heat insulator that is configured by evacuating a container-like exterior body containing a filler.

  In this type of vacuum heat insulating body, for example, a container-shaped outer body constituted by bonding the peripheral portions of two outer members constituted by attaching an aluminum foil to a plastic film and preparing a paper Alternatively, a filled body in which pearlite powder or silica fine powder, which is a heat insulating material, is contained in a bag body having air permeability such as a nonwoven fabric and molded into a predetermined shape, or made of a plastic foam having a high continuous porosity. In a state where a filler is prepared and such a filler is accommodated in the exterior body, air in the exterior body is opened in the exterior body (opening on one side of the peripheral portions of the two outer members removed from the joint). It is known that the structure is hermetically sealed by evacuating from the part) and then joining the opening of the exterior body.

  FIG. 1 is a sectional view showing an example of the vacuum heat insulating material having this configuration. In the same figure, the exterior body 12 is comprised in the shape of the flat rectangular container sealed by joining the peripheral part of the two outline members 13 which make a rectangular shape. The two outer members 13 are both made of a non-breathable laminate film. Specifically, an aluminum foil 15 for blocking air permeability is bonded to one side of a plastic film 14 serving as a base material. And a three-layer structure in which a heat seal layer 16 made of a thermoplastic is provided on the surface of the aluminum foil 15, and the bonding between the two outer members 13 is performed by thermocompression bonding between the heat seal layers 16. It is done by.

  Here, as the plastic film 14, a film such as polyethylene terephthalate (PET) or nylon is used, and as the heat seal layer 16, polyethylene (PE), polypropylene (PP), or the like is used.

  A filling body 17 is accommodated in the exterior body 12, and the filling body 17 is a pearlite powder, a silica fine powder, or the like, which is a heat-insulating material, in a breathable bag body 18 such as paper or nonwoven fabric. The filler 19 is accommodated and molded into a predetermined shape.

  The vacuum heat insulator 11 having such a configuration is manufactured by the following process. That is, the outer shell 12 is formed in a bag body having an opening on one side by overlapping the two outer members 13 and joining the three sides thereof, and the heat insulating material 17 is passed through the opening. Accommodate. Next, the air in the exterior body 12 is exhausted by evacuation through the opening, and then the opening is joined. This vacuum insulator 11 is used, for example, as a constituent material of a heat insulating box of a refrigerator, and is arranged so that one side is the inside of the box and the other side is the outside of the box in a shape in which the peripheral portion is bent. It is common.

  In the vacuum heat insulating material 11 configured in this way, the initial thermal conductivity exhibits excellent heat insulating property of about 0.006 kcal / mh ° C., and a heat insulating body using a conventional rigid polyurethane foam and When compared, the insulation performance is about 3 times or more.

  However, since the plastic film 14 used as the base material of the outer member 13 and the thermoplastic plastic used for the heat seal layer 16 do not have a complete air barrier property, aluminum having an excellent air barrier property to compensate for this. A foil 15 is attached. Although the aluminum foil 15 is extremely thin of about 6 μm, the heat conductivity of the aluminum itself is high, so that heat conduction called heat bridge occurs on both surfaces of the heat insulating material 17 through the aluminum foil 15 of the outer member 13, and the vacuum heat insulating body. 11 heat insulation performance is reduced.

  Furthermore, when the aluminum foil 15 is viewed microscopically, there are innumerable fine holes. For this reason, the inside of the exterior body 12 maintains a high air barrier property (high vacuum) in the initial stage and has excellent heat insulation performance, but gas molecules gradually pass through the outer member 13 and enter the exterior body 12. As a result, the degree of vacuum in the exterior body 12 is lowered, and the heat insulation performance is lowered. In order to prevent such intrusion of gas molecules through the outer member 13, the aluminum foil 15 is thickened to such an extent that there are no fine holes penetrating between the front and back surfaces (thickness direction) in the aluminum foil 15. Alternatively, it is necessary to form aluminum in advance on the plastic film 14 by vacuum deposition or the like. However, in such a case, the above-described heat bridge phenomenon due to the high thermal conductivity of the aluminum itself becomes large, and there is a problem that the heat insulating performance of the vacuum heat insulating body 11 is lowered. In particular, there is a problem that the thermal conductivity including the heat bridge of the bent portion becomes higher, and the heat insulating performance of the entire vacuum heat insulating body 11 further decreases.

Therefore, in order to reduce the heat bridge through the outer shell member 13, instead of the aluminum foil 15 attached to ensure air insulation, Cr such as SUS304 or SUS430 having poorer thermal conductivity is used. And a vacuum heat insulator using Ni-based stainless steel foil (see, for example, Patent Documents 1 to 3).
JP-A-7-98091 (Claim 4) Japanese Patent Laid-Open No. 7-63469 (7th sentence of paragraph 0009) JP-A-8-105687 (paragraph 0019)

  In the stainless steel foil described above, the thermal conductivity inherent to the material is lower than that of aluminum and can be reduced to about 1/10 to 1/8 that of aluminum, and the thermal conductivity of the vacuum insulator is also 0.0029 to 0.0030 kcal / The heat insulation performance can be improved up to mh ° C.

  It is an object of the present invention to provide a vacuum heat insulating body having a more excellent heat insulating performance by reducing the heat bridge of the outer member than the vacuum heat insulating material using the stainless steel foil.

  The gist of the present invention is as follows.

(1) An exterior body that is formed into a sealed container shape by joining outer members formed of at least a metal foil, and is evacuated by discharging the air inside;
It consists of a filler having heat insulation contained in the exterior body,
A vacuum heat insulator, wherein the metal foil is a stainless steel foil containing 3 to 10% by mass of aluminum.

(2) an exterior body that is formed into a sealed container shape by joining at least an outer member composed of a metal foil, and is evacuated by discharging the air inside;
It consists of a filler having heat insulation contained in the exterior body,
The vacuum heat insulating body characterized in that at least one of the metal foils is formed of a stainless steel foil containing 3 to 10% by mass of aluminum.

  (3) The vacuum heat insulator according to (1) or (2) above, wherein the stainless steel foil has a thickness of 8 to 30 μm.

  (4) The outer shell member is joined by joining the thermoplastic resin films laminated on the metal foil by thermocompression bonding, as described in any one of (1) to (3) above Vacuum insulation.

  (5) The two outer members constituting the exterior body are each selected from the group consisting of a heat seal layer / metal foil two-layer structure material and a heat seal layer / metal foil / surface protective layer three-layer structure material The vacuum heat insulating body according to any one of the above (1) to (4), wherein both are used with the heat seal layer side inside.

  (6) The stainless steel foil used for the vacuum heat insulating material in any one of said (1)-(5) containing 3-10 mass% of aluminum.

  In the vacuum heat insulating body of the present invention, by using a stainless steel foil containing 3 to 10% by mass of aluminum as the metal foil constituting the outer member, the thermal conductivity of stainless steel containing 3 to 10% by mass of aluminum is used. Is about 1/16 compared to conventional aluminum, and about 1/2 compared to stainless steel such as Cr, Ni-based SUS304, SUS430, etc. that do not contain aluminum. When compared with a thickness that does not exist, vacuum insulation using foil made of stainless steel containing 3 to 10% by mass of aluminum can reduce the outer bridge member, particularly the heat bridge including the bent portion. The thermal conductivity including the heat bridge of the bent portion can be lowered (insulating performance can be increased).

  According to the vacuum heat insulating body according to claim 3, by setting the thickness of the stainless steel foil to 8 to 30 μm, it is possible to prevent the formation of fine holes in the stainless steel foil by increasing the thickness, The work of manufacturing the exterior body from the members can be made good.

  For this reason, in addition to building materials such as household or commercial refrigerators, refrigerated and refrigerated cargo (trucks), etc., equipment that has refrigeration and refrigeration functions, and insulation box bodies such as refrigeration and refrigeration warehouses, buildings such as walls and floors It can be widely applied to heat insulating materials such as building materials for heat insulation such as wood, and building materials for heat insulation such as wall materials and floor materials. In particular, when it is used as a component material for heat-insulating boxes such as refrigerators and refrigerator / refrigerated cargo (trucks), etc. The inside of the cabinet can be increased without changing the volume outside the refrigerator, and can greatly contribute to power saving.

  As a first embodiment of the vacuum heat insulating body according to the present invention, it is formed into a sealed container shape by joining at least outer members made of metal foil, and the inside air is discharged to be in a vacuum state. The metal foil is a stainless steel foil containing 3 to 10% by mass of aluminum. In 1st Embodiment, as described above, the heat conductivity including the heat bridge of a bending part can be made low, and the heat insulation performance of a vacuum heat insulating body can be improved further.

  Further, as a second embodiment of the vacuum heat insulating body according to the present invention, it is formed in a sealed container shape by joining at least an outer member made of a metal foil, and the inside air is discharged to form a vacuum state. A stainless steel foil containing 3 to 10% by mass of aluminum, wherein at least one metal foil of the metal foil is made of a heat-insulating filler housed in the exterior body. It is formed. In the embodiment, at least one metal foil of the outer member metal foil is formed of a stainless steel foil containing 3 to 10% by mass of aluminum, and the remaining one side portion is made of another metal foil such as an aluminum foil or aluminum. By forming the stainless steel foil out of the range of 3 to 10% by mass, the vacuum heat insulator can be constructed at a low cost while maintaining the effects described in the first embodiment to some extent. It has the advantage that it can.

  Hereinafter, each embodiment of the vacuum heat insulator according to the present invention will be described with reference to the drawings.

  First, a first embodiment of the present invention will be described with reference to FIG. FIG. 1A is a schematic perspective view of a vacuum heat insulating body, and FIG. 1B is a cross-sectional view taken along line AA of FIG. 1A, and shows a three-layer structure as one typical structural example of the first embodiment of the present invention. It is the longitudinal cross-sectional view which represented typically the vacuum heat insulating body which uses this outer shell member. FIG. 2A is a schematic perspective view of another typical vacuum insulator according to the first embodiment of the present invention, and FIG. 2B is a cross-sectional view taken along line AA of FIG. It is the longitudinal cross-sectional view which represented typically the vacuum heat insulating body which uses the outer-layer member of a 2 layer structure as another typical structural example of embodiment.

  FIG. 1 and FIG. 2 show a panel-shaped vacuum heat insulating body 11 in a completed state, and an airtight container-shaped exterior body 12 whose inside is evacuated is composed of two outer members formed in a rectangular shape. It is comprised by joining 13 by the peripheral part (peripheral part) 13a. In addition, the outer package 12 contains a filler 17 having heat insulation properties.

  In this case, the two exterior members 13 are both made of a non-breathable laminate film. Specifically, as shown in FIG. 1B, the breathability is blocked on one surface of the plastic film 14 as a base material. As a metal foil, a stainless steel foil 15 containing 3 to 10% by mass of aluminum is bonded, and a heat seal layer 16 made of a thermoplastic resin is provided inside the stainless steel foil 15 to form a three-layer structure. ing. Alternatively, as shown in FIG. 2B, a stainless steel foil 15 containing 3 to 10% by mass of aluminum is bonded as a metal foil for blocking air permeability, and a thermoplastic resin is formed inside the stainless steel foil 15. It has a two-layer structure provided with a heat seal layer 16. And the joining of the peripheral part (peripheral part) 13a between the said 2 outer shell members 13 is performed by carrying out the thermocompression bonding of the heat seal layers 16. FIG.

  Here, the plastic film 14 constituting the outer member 13 is not particularly limited as long as it does not impair the effects of the present invention, but it does not melt when the heat seal layer is thermocompression bonded. Polyethylene terephthalate (PET), polyamide from the viewpoints of heat resistance, easy processability (molding processability) that can be easily molded into a container shape, insulation, flexibility, mechanical strength suitable for surface protection, weather resistance, etc. (Nylon) and the like are preferable.

  The thickness of the plastic film 14 is not particularly limited as long as it does not impair the effects of the present invention, but is in the range of 10 to 30 μm. If it is less than 10 μm, it is difficult to produce a plastic film due to the influence of dust and the like. On the other hand, when the thickness exceeds 30 μm, there is no particular problem, but there is no advantage in increasing the thickness.

  Moreover, in this invention, the stainless steel foil 15 containing 3-10 mass% of aluminum (Al) is used as metal foil for interrupting | blocking the air permeability which comprises the outer shell member 13, It is characterized by the above-mentioned. This is due to the following reason. Among metal elements, Al has a relatively high thermal conductivity, and Cr and Ni are significantly lower by about 1/3 than the thermal conductivity of Al. For this reason, these stainless steel foils containing Cr and Ni have a thermal conductivity as low as about 1/8 as compared with Al foils. Therefore, such stainless steel foils are used as outer members of vacuum heat insulating materials. In the present invention, a stainless steel foil containing 3 to 10% by mass of Al having higher thermal conductivity than Cr or Ni is compared with Cr or Ni-based stainless steel foil (not containing Al) such as SUS304 and SUS430. It was found that the thermal conductivity, which was supposed to be high, was halved to about ½ (see Example 1 and Comparative Examples 1 and 2 in comparison). As a result, in the vacuum heat insulating material using the stainless steel foil containing 3 to 10% by mass of this Al, the heat insulating performance as compared with the vacuum heat insulating material using the Cr, Ni-based stainless steel foil (not containing Al). This is advantageous in that it can be improved.

  Here, when the aluminum content in the stainless steel foil 15 is less than 3% by mass, the thermal conductivity is increased, and the performance difference from the stainless steel of SUS304 or SUS430 containing ordinary Cr or Ni is reduced. . Moreover, when there is more aluminum content than 10 mass%, productivity of foil rolling will deteriorate very much and it cannot apply to actual production.

  The thickness of the stainless steel foil 15 is preferably 8 to 30 μm in consideration of eliminating pinholes and production efficiency in the foil rolling process. More preferably, the thickness is 10 to 20 μm. If it is thinner than 8 μm, the probability of pinholes is increased and the production of foil becomes very difficult, which is not practical. On the other hand, if it is thicker than 30 μm, the heat conduction increases and the performance difference from normal stainless steel becomes small. In addition, it goes without saying that the effect is more remarkable as the thickness is reduced in order to reduce the heat bridge. On the other hand, in order to prevent gas molecules from gradually passing through the outer shell member by the fine holes penetrating between the front and back surfaces (thickness direction) of the stainless steel foil 15, the effect is more remarkable as the thickness increases. It can be said that having a thickness of 8 μm or more is effective in maintaining the degree of vacuum for a long time.

  The heat seal layer 16 constituting the outer member 13 is not particularly limited as long as it exhibits good sealing performance by thermocompression bonding and does not impair the effects of the present invention. Examples thereof include polyethylene (PE) and polypropylene (PP) which are plastic plastics.

  The thickness of the heat seal layer 16 is not particularly limited as long as it does not impair the effects of the present invention, but is in the range of 20 to 50 μm. When the thickness is less than 20 μm, a problem in heat seal reliability is likely to occur due to the influence of dust or the like. On the other hand, when it exceeds 50 μm, the degree of vacuum tends to deteriorate with time due to the gas permeability of the resin itself of the heat seal layer.

  The joining of the peripheral part (peripheral part) 13a between the two outer shell members 13 is preferably performed by thermocompression bonding of the heat seal layers 16 to each other. The joining of the two outer members 13 is a thermoplastic laminated on the stainless steel foil 15 containing 3 to 10 mass% of aluminum rather than joining the stainless steel foil 15 containing 3 to 10 mass% of aluminum by welding. This is because it is better to thermocompression-bond resin films 16 having heat sealing properties such as resin films. Moreover, it is also because a heat bridge becomes small in order to pass through the thermoplastic resin film whose heat conductivity is worse than the stainless steel foil 15 containing 3-10 mass% of aluminum.

  Therefore, if the width (area) of the joint portion of the peripheral portion (peripheral portion) 13a between the two outer members 13 is increased, it is advantageous in increasing the adhesive strength and the sealing property and maintaining the vacuum state for a long time. That is, if the joint portion (seal portion) is weak, air may enter the inside through the seal surface. On the other hand, in order to reduce the thermal conductivity including the joint (bent part), it is preferable that the width (area) of the joint is small. Taking these into consideration, the width of the peripheral portion (peripheral portion) 13a = joining portion is 10 to 30 mm. If it is less than 10 mm, the adhesive strength and sealability may be insufficient. On the other hand, if it exceeds 30 mm, it may be difficult to lower the thermal conductivity including the bent portion.

  In this embodiment, in addition to the three-layer outer member 13 as shown in FIG. 1B, for example, a two-layer outer member 13 of the stainless steel foil 15 and the heat seal layer 16 as shown in FIG. 2B is used. May be. That is, the plastic film 14 can be an optional component. However, since it is difficult to give the metal foil or the heat seal layer 16 all the various functions required for the plastic film 14, it can be said that it is desirable to use the plastic film 14 to have a three-layer structure. Furthermore, a multilayer structure of four or more layers may be used as long as the effects of the present invention are not impaired. In this case, the above-described stainless steel foil 15 and a plurality of plastic films may be laminated in multiple layers, and still other functions such as a resin film layer having excellent gas barrier properties and a heat insulating function other than the stainless steel foil 15 There is no particular limitation such that a resin film layer or the like having a suitable thickness may be provided at an optimal position.

  Furthermore, in the present embodiment, the outer member 13 is not limited to the multilayer structure. For example, even if the innermost heat seal layer 16 is not formed on the entire surface of the outer member 13, at least the peripheral portion (peripheral portion) where the heat seal layer is required and the vicinity thereof can achieve the purpose. It may be provided only in the part. Thus, regarding the structure of the outer shell member 13, it may have the stainless steel foil 15 containing at least 3 to 10% by mass of aluminum, and is not particularly limited as long as the effects of the present invention are not impaired. .

  The shape of the container-shaped exterior body 12 formed by joining the peripheral portions (peripheral portions) 13a of the two outer shell members 13 is also particularly limited as long as it does not impair the effects of the present invention. It is not a thing. For example, as shown in FIG. 1, two outer members 13 are both convex (or concave) in cross section, and as shown in FIG. 2, one outer member 13A is convex (or concave) in cross section. Examples include a shape in which the outer member 13B is joined to a planar one. Furthermore, although the central convex (or concave) portion of FIGS. 1 and 2 has a flat shape, it may be wavy or a shape having protrusions.

  Moreover, in FIG.1 and FIG.2, although the one exterior body 12 is formed by joining the surrounding part 13a of the two outer shell members 13, it is large so that many exterior bodies 12 can be formed at once. A plurality of exterior bodies 12 may be created using the outer member 13, and the joined peripheral portion (peripheral portion) 13a may be cut and separated as necessary, or the plurality of exterior bodies 12 are connected. It may be used in the state.

  FIG. 3 is a schematic perspective view of still another typical vacuum insulator according to the first embodiment of the present invention. As shown in FIG. 3, in the present invention, the exterior body 12 may be formed using a single outer member 13. Specifically, one outer member 13 is rolled into a cylindrical shape, and the overlapped peripheral portions 13b are joined together by thermocompression bonding (the joining portion 13b). Next, of the cylindrical upper and lower openings, One of the two is bonded by thermocompression bonding (the bonding portion 13c), and a filler (not shown) having heat insulating properties is accommodated from the remaining opening, and after the internal air is discharged, the opening 13c is thermocompression bonded. Thus, the vacuum heat insulating body 11 whose inside is evacuated may be formed by bonding (the bonding portion 13d). In this way, the vacuum heat insulating body 11 may be formed by using one outer shell member 13, and if necessary, the inner portion is vacuumed by appropriately thermocompression bonding the three or more outer shell members 13. It is not particularly limited, for example, a vacuum heat insulator made into a state may be used.

  In addition, the outer package 12 contains a filler 17 having heat insulation properties. The structure of the filler 17 having the heat insulating property is not particularly limited as long as it does not impair the effects of the present invention. For example, (1) as shown in FIG. 1B and FIG. 2B, the air-permeable bag 18 made of paper or nonwoven fabric is filled with pearlite powder, silica fine particles or the like with low gas adsorbability and heat insulation. Examples thereof include those formed by accommodating the material 19 and formed into a desired shape, and (2) those made of a plastic foam having a high continuous porosity.

  The thickness of the bag body 18 is not particularly limited as long as the air permeability defined above can be maintained when the air inside the filler 19 is exhausted when evacuated.

  Next, the manufacturing method of the vacuum heat insulating body 11 of this invention is demonstrated using drawing.

  A vacuum heat insulator 11 having a structure as shown in FIGS. 1 and 2 was manufactured by the following process. That is, the outer peripheral body 12 has an opening (not shown) on one side by joining the peripheral portions of the three sides of the rectangular outer shell member 13 by thermocompression bonding (thermal fusion). It forms in a bag shape and the filling body 17 is accommodated in the inside from the said opening part. Next, the air in the exterior body 12 is evacuated from the opening functioning as an exhaust port, and the pressure is reduced to about 0.001 torr (1 torr = corresponding to about 133.3224 Pascals). And it can form by thermocompression-bonding and joining the one side part (opening part) which the exterior body 12 remains.

  The vacuum heat insulating body 11 configured in this way has a shape in which a peripheral portion (peripheral portion) is bent, and is used, for example, as a constituent member of a heat insulating box body of a refrigerator. It arrange | positions so that it may become a warehouse inner side (not shown).

  Next, a second embodiment of the present invention will be described with reference to the drawings. FIG. 4 is a longitudinal sectional view schematically showing a vacuum heat insulating body using a three-layer outer shell as a typical structural example of the second embodiment of the present invention. FIG. 5 is a longitudinal sectional view schematically showing a vacuum heat insulating body using a two-layer outer shell as another typical structural example of the second embodiment of the present invention. 4 and 5 are the same as the external perspective view of the vacuum heat insulating body of the first embodiment shown in FIGS. 1A and 2A, and therefore the drawings are omitted for these. . Also in the second embodiment, the same structure as that of the external perspective view of the vacuum heat insulating body of the first embodiment as shown in FIG. 3 can be used, but the drawing is omitted because it does not change in the drawing.

  4 and 5 show a panel-shaped vacuum heat insulating body 11 in a completed state, and an outer casing 12 in a sealed container shape whose inside is evacuated is composed of two outer members 13A formed in a rectangular shape. , 13B are joined by the peripheral part (peripheral part) 13a. In addition, the outer package 12 contains a filler 17 having heat insulation properties.

  Also in this embodiment, the two exterior members 13A and 13B are both made of a non-breathable laminate film. Specifically, as shown in FIG. 4, on one side of the plastic film 14 as a base material. A metal foil 15 for blocking air permeability is adhered, and a three-layer structure is provided in which a heat seal layer 16 made of a thermoplastic resin is provided inside the metal foil 15. Alternatively, as shown in FIG. 5, a stainless steel foil 15 containing 3 to 10 mass% of aluminum is bonded as a metal foil for blocking air permeability, and a thermoplastic resin is formed inside the stainless steel foil 15. It has a two-layer structure provided with a heat seal layer 16. And joining of the peripheral part (peripheral part) 13a between the said 2 outer shell members 13A and 13B is performed by carrying out the thermocompression bonding of the heat-seal layer 16. FIG.

  In this embodiment, at least one side portion of the container-shaped outer package 12 of the metal foil 15 is formed of a stainless steel foil 15A containing 3 to 10% by mass of aluminum, and the remaining one side portion is made of another metal foil (FIG. 4). No. 5 is formed by an aluminum foil 15B).

  The stainless steel foil 15A containing 3 to 10% by mass of aluminum that can be used for at least one side portion of the container-shaped exterior body 12 is the same as that described in the first embodiment of the present invention, so here. Description of is omitted.

  Here, as shown in FIGS. 4 and 5, at least one side portion of the exterior body is (1) a stainless steel foil 15A containing 3 to 10% by mass of aluminum in the entire exterior member 13A of the exterior body. In addition, (2) only one surface portion of the outer package 12 may be a stainless steel foil 15A containing 3 to 10% by mass of aluminum. This is because even with such a configuration, the effects of the present invention can be sufficiently exhibited. That is, in order to reduce the thermal conductivity including the outer member, particularly the bent portion, the peripheral portion 13a of the outer package 12 has the greatest influence, and aluminum is added to 3 to 10% by mass on at least one side of this portion. The object can be achieved by applying the stainless steel foil 15 to be contained.

  Moreover, as other metal foil (in FIG. 4, 5, aluminum foil 15B) which can be used for the part on the opposite side of the container-shaped exterior body 12, for example, stainless steel whose aluminum content deviates from 3 to 10% by mass In addition to foil, other metal foils other than stainless steel foil such as aluminum foil can be used as appropriate. These may have a single-layer structure or a multilayer structure of two or more layers. Needless to say, in the case of a multilayer structure of two or more layers, a stainless steel foil containing 3 to 10% by mass of aluminum in one layer may be used.

  In 2nd Embodiment of this invention, except the structure regarding the above-mentioned metal foil, it is the same as that of 1st Embodiment of this invention, and the vacuum heat insulating body 11 of this embodiment can be obtained with the same manufacturing method. Therefore, the description here is omitted.

  Moreover, in the vacuum heat insulating body 11 of the present invention, the initial thermal conductivity including the bent portion of the vacuum heat insulating body 11 (the peripheral portion 13a of the exterior body 12) is 0.0025 kcal / mh ° C., regardless of the embodiment. In the following, it is desirable to appropriately select each component so that it is preferably 0.002 kcal / mh ° C. or less. That is, in the present invention, the heat conductivity including the bent portion of the vacuum heat insulating body 11 (the peripheral portion 13a of the exterior body 12) is further reduced as compared with the prior art, and high heat insulating performance is maintained for a long time. It is further desirable to provide such a vacuum insulation at a lower cost. For this reason, it is desirable to select a component that is optimal in terms of both performance and cost with respect to the component requirements other than the material of the metal foil. In addition, in the case where the initial thermal conductivity including the bent portion of the vacuum heat insulator 11 exceeds 0.003 kcal / mh ° C., as compared with the conventional vacuum heat insulator as described in Patent Documents 1 to 3, The thermal conductivity including the bent portion cannot be sufficiently reduced.

  Hereinafter, examples according to each embodiment of the present invention will be described in detail with reference to the drawings.

Example 1
A specific example of the first embodiment of the present invention will be described with reference to FIG. The figure shows the panel-shaped vacuum heat insulating body 11 in a completed state, and the sealed container-shaped outer body 12 whose inside is evacuated to 0.001 torr (corresponding to 1 torr = about 133.3224 Pascals) It is configured by joining two outer shell members 13 formed in a rectangular shape at the periphery (joining width 15 mm). The two exterior members 13 are both made of a non-breathable laminate film, and a stainless steel foil 15 for blocking the breathability is bonded to one side of the plastic film 14, and the inside of the stainless steel foil 15. The heat seal layer 16 made of a thermoplastic resin is provided in the three-layer structure, and the joining between the two outer members 13 is performed by thermocompression bonding between the heat seal layers 16. Moreover, the exterior body 12 is formed in a desired shape shown in FIG. 1A by accommodating a filler 17 having heat insulation properties.

  In this example, a 25 μm thick film made of nylon was used as the plastic film 14, and a 50 μm thick polyethylene film was used as the heat seal layer 16. The stainless steel foil 15 is made of stainless steel containing 5% by mass of aluminum and has a thickness of 10 μm (YUS205M1 manufactured by Nippon Steel Corporation). Moreover, the foaming urethane of thickness 10mm was used as the filler 17 which has heat insulation.

  The vacuum heat insulator 11 having such a configuration was manufactured by the following process. That is, the outer side body 12 is formed in a bag shape having an opening on one side by thermocompression bonding of the three sides of the two rectangular outer members 13A, and the opening is formed therein. From above, the filler 17 having the heat insulating property was accommodated. Next, the air in the exterior body 12 is evacuated from the opening functioning as an exhaust port, and the pressure is reduced to about 0.001 torr (1 torr = corresponding to about 133.3224 Pascals). Then, the remaining one side (opening) of the exterior body 12 is bonded by thermocompression bonding. The vacuum heat insulating body 11 configured in this manner has a shape in which a peripheral portion is bent, and is used, for example, as a constituent member of a heat insulating box body of a refrigerator, with one surface being the outer side and the other surface being the inner side. Therefore, in the following measurement, the measurement was performed in a shape in which the peripheral portion was bent similarly.

  According to the vacuum heat insulating body 11 having the above structure, the thermal conductivity of the stainless steel foil 15 used for the metal foil of the outer member 13 constituting the exterior body 12 is 11.3 kcal / mh ° C., and the vacuum heat insulating material using this The initial thermal conductivity of the body 11 was 0.0021 kcal / mh ° C. including the heat bridge at the bent portion.

Example 2
Similarly to Example 1 of the present invention, a vacuum heat insulating material was made of stainless steel foil 15 made of stainless steel containing 8% by mass of aluminum.

  The thermal conductivity of the stainless steel foil 15 is 9.8 kcal / mh ° C., and the initial thermal conductivity of the vacuum heat insulating body 11 using the stainless steel foil 15 is 0.0018 kcal / mh ° C. including the bent partial heat bridge. It was.

Example 3
A specific example of the second embodiment of the present invention will be described with reference to FIG. The figure shows the panel-shaped vacuum heat insulating body 11 in a completed state, and the sealed container-shaped outer body 12 whose inside is evacuated to 0.001 torr (corresponding to 1 torr = about 133.3224 Pascals) The two outer members 13A and 13B formed in a rectangular shape are joined at their peripheral portions (joining width 15 mm). Both the exterior members 13A and 13B are made of a non-breathable laminate film, and a metal foil 15 for blocking air permeability is bonded to one surface of the plastic film 14 and a thermoplastic is provided inside the metal foil 15. It has a three-layer structure in which a heat seal layer 16 made of resin is provided, and the outer members 13A and 13B are joined by thermocompression bonding of the heat seal layers 16. In addition, the exterior body 12 is formed in a desired shape shown in FIG. 4 (the same external shape as in FIG. 1A) by accommodating a filler 17 having heat insulation properties.

  In the present embodiment, as the metal foil 15 of the outer member 13A constituting the exterior body 12 of the vacuum heat insulating body 11 in FIG. 4, a stainless steel foil 15A (Nippon Steel Corporation) having a thickness of 10 μm and containing 5% by mass of aluminum is used. YUS205M1) manufactured by company was used. Further, as the metal foil 15 of the outer member 13B constituting the opposite side, an aluminum foil 15B having a thickness of 6 μm was used. Except for this configuration, the vacuum heat insulator 11 of Example 2 was produced in the same manner as in Example 1 by the same manufacturing method as in Example 1.

  The thermal conductivity of the stainless steel foil 15A is 11.3 kcal / mh ° C., and the thermal conductivity of the aluminum foil 15B is 200 kcal / mh ° C., and the initial thermal conductivity of the vacuum thermal insulator 11 using these. Was 0.0025 kcal / mh ° C. including the bent part heat bridge.

Comparative Example 1
As Comparative Example 1, SUS304 (generally composition 18Cr-8Ni; aluminum content 0 mass%) stainless steel having a thickness of 10 μm is used as the metal foil 15 of the outer members 13A and 13B constituting the exterior body 12 of the vacuum heat insulating body 11 of FIG. Steel foil 15 was used. Except for this configuration, the vacuum heat insulator 11 of the present comparative example 1 was produced in the same manner as in Example 1 and the same manufacturing method.

  The thermal conductivity of the stainless steel foil 15 is 16.3 kcal / mh ° C., and the initial thermal conductivity of the vacuum heat insulator 11 using the stainless steel foil 15 is 0.0032 kcal / mh ° C. including a bent partial heat bridge. there were.

Comparative Example 2
As Comparative Example 2, as the metal foil 15 of the outer members 13A and 13B constituting the exterior body 12 of the vacuum heat insulating body 11 of FIG. 1, SUS430 (generally composition 18Cr; aluminum content 0 mass%) stainless steel foil having a thickness of 10 μm 15 was used. Except for this configuration, the vacuum heat insulator 11 of Comparative Example 2 was produced in the same manner as in Example 1 by the same manufacturing method.

  The thermal conductivity of the stainless steel foil 15 is 26.0 kcal / mh ° C., and the initial thermal conductivity of the vacuum heat insulator 11 using the stainless steel foil 15 is 0.0045 kcal / mh ° C. including the bent part heat bridge. there were.

Comparative Example 3
As Comparative Example 3, an aluminum foil 15 having a thickness of 6 μm was used as the metal foil 15 of the outer members 13A and 13B constituting the exterior body 12 of the vacuum heat insulating body 11 of FIG. Except for this configuration, the vacuum heat insulator 11 of Comparative Example 3 was produced in the same manner as in Example 1 and the same manufacturing method.

  The thermal conductivity of the aluminum foil 15 was 200 kcal / mh ° C., and the initial thermal conductivity of the vacuum heat insulator 11 using the aluminum foil 15 was 0.0105 kcal / mh ° C. including the heat bridge of the bent portion. .

  As is apparent from the measurement results of the thermal conductivity including the bent portions of the vacuum heat insulators 11 of Examples 1 and 2 and Comparative Examples 1 to 3, an aluminum foil or a conventional stainless steel is used as the metal foil 15 of the exterior body 12. Compared to SUS304 and SUS430 (not containing Al), which are steel foils, by using the stainless steel foil 15 containing 5% by mass of aluminum according to the present invention, the thermal conductivity of the vacuum insulator 11 is lowered. Can do. For this reason, when using the vacuum heat insulating body 11 for the constituent material of the heat insulation box of a refrigerator, for example, one surface (for example, lower surface) made into the refrigerator outer side through this stainless steel foil 15 The amount of heat transferred from one side to the other side (upper surface), that is, the heat bridge, that is, the heat bridge, is smaller than that when an aluminum foil or a stainless steel foil containing no aluminum is used. That is, higher heat insulation performance can be exhibited.

FIG. 2 is a schematic perspective view of an upper and lower double-sided convex vacuum heat insulator using a three-layer outer shell as a typical structural example of the first embodiment of the present invention. 1A is a cross-sectional view taken along the line AA of FIG. 1A, and is a vertical cross-sectional view schematically showing a vacuum heat insulating body using a three-layer outer member as a typical structural example of the first embodiment of the present invention. It is a top view (it was employ | adopted also as the longitudinal cross-sectional view of the vacuum heat insulating body obtained in Example 1 of this invention and Comparative Examples 1-3). FIG. 4 is a schematic perspective view of a vacuum heat insulating body that is convex only on one upper surface, using a two-layer outer shell as another typical structural example of the first embodiment of the present invention. FIG. 2B is a cross-sectional view taken along line AA in FIG. 2A, schematically showing a vacuum heat insulating body using a two-layer outer member as another typical structural example of the first embodiment of the present invention. FIG. FIG. 6 is a schematic perspective view of still another vacuum heat insulator representative of the first embodiment of the present invention, in which a vacuum heat insulator is formed using a single outer member. As a typical structural example of the second embodiment of the present invention, a longitudinal sectional view schematically showing a vacuum heat insulating body using a three-layer outer shell member (obtained in Example 2 of the present invention) It was also adopted as a vertical cross-sectional view of the vacuum insulator. It is the longitudinal cross-sectional view which represented typically the vacuum heat insulating body which uses the outer-layer member of a 2 layer structure as another typical structural example of the 2nd Embodiment of this invention.

Explanation of symbols

11 Vacuum insulator,
12 exterior body,
13 (and 13A, 13B) outer member,
13a, 13b, 13c, 13d Joining part (thermocompression sealing part) of outer member
14 Plastic film,
15 (and 15A) metal foil or stainless steel foil,
15B aluminum foil,
16 heat seal layer,
17 Filling body having heat insulation properties,
18 Breathable bag body,
19 Filling material having low heat absorption properties with low gas adsorption.

Claims (6)

Formed in a sealed container shape by joining outer members made of at least metal foil, and has an exterior body that is evacuated by discharging the air inside, and has a heat insulating property accommodated in the exterior body A filling body,
A vacuum heat insulator, wherein the metal foil is a stainless steel foil containing 3 to 10% by mass of aluminum. Formed in a sealed container shape by joining outer members made of at least metal foil, and has an exterior body that is evacuated by discharging the air inside, and has a heat insulating property accommodated in the exterior body A filling body,
A vacuum heat insulating body, wherein at least one of the metal foils is formed of a stainless steel foil containing 3 to 10% by mass of aluminum.   The vacuum insulator according to claim 1 or 2, wherein the stainless steel foil has a thickness of 8 to 30 µm.   The vacuum insulator according to any one of claims 1 to 3, wherein the joining of the outer member is performed by joining thermoplastic resin films laminated on a metal foil by thermocompression bonding. Two outer members to be joined
(1) A heat seal layer and a metal foil two-layer structure material, and (2) a heat seal layer, a metal foil, and a three-layer structure material of a surface protective layer. The vacuum heat insulator according to any one of claims 1 to 4, wherein the vacuum heat insulator is used with the layer side inward.   The stainless steel foil used for the vacuum heat insulating body in any one of Claims 1-5 containing 3-10 mass% of aluminum.

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