JP2010090905A - Vacuum heat insulation material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vacuum heat insulation material exhibiting superior heat insulation performance over a long period. <P>SOLUTION: In the vacuum heat insulation material 1, a core material 2 and an adsorbent 3 are sealed in a decompressed state between two rectangular outer covering parts 4 where thermally fused layers 7 face each other, and three sides of outer peripheral parts near peripheral ends of the two outer covering members 4 covering the core material 2 are thermally fused. The thermally fused layer 7 positioned in a sealing part 8 includes a recession of a substantially circular arc shape when viewing a cross section when the three-side sealing part 8 out of the sealing part 8 where the outer peripheral parts of the covering member 4 are thermally fused are cut in a plane vertical to the peripheral end, and a thin part 9 having a thickness of the thermally fused layer 7 thinner than a peripheral part of an innermost part is formed on the innermost part of the recession, and occurrence of a crack in the thin part 9 suppressing an atmospheric gas amount intruding from an end surface of the peripheral end of the outer covering member 4 through the sealing part 8 and breakage of the sealing part 8 are suppressed. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a vacuum heat insulating material.

  In recent years, as a measure against global warming, which is a serious global environmental problem, there has been an active movement to promote energy conservation in home appliances, equipment, and buildings such as houses, and a vacuum that has an excellent thermal insulation effect over the long term. Insulation is more demanded than ever.

  The vacuum heat insulating material is a material in which a core material having fine voids such as glass wool or silica powder is covered with a jacket material having gas barrier properties, and the inside of the jacket material is sealed under reduced pressure. A vacuum heat insulating material enables expression of a high heat insulating effect by keeping the inner space in a high vacuum and reducing the amount of heat transmitted through the gas phase as much as possible. Therefore, a technique for maintaining a high degree of vacuum inside the vacuum heat insulating material is extremely important in order to exhibit the excellent heat insulating effect over a long period of time.

  As a method for maintaining the degree of vacuum inside the vacuum heat insulating material, a method in which a gas adsorbent or a moisture adsorbent is sealed under reduced pressure inside the vacuum heat insulating material together with the core material is generally used. As a result, residual moisture released into the vacuum heat insulating material from the minute gaps in the core material after vacuum packaging, or atmospheric gases such as water vapor and oxygen that permeate through the jacket material from the outside air and permeate into the vacuum heat insulating material over time. Can be removed.

  However, considering the adsorption capacity of existing adsorbents, it can be said that the use of adsorbents alone is insufficient to provide a vacuum insulation material that maintains a high thermal insulation effect over the long term. It is necessary to take measures to control the amount of atmospheric gas that is generated.

  Here, a gas path entering from the outside air into the vacuum heat insulating material will be described.

  The vacuum heat insulating material is usually a three-way sealing bag that is formed by superposing two rectangular outer covering materials and heat-sealing the outer peripheral portions in the vicinity of the three sides of the outer covering material. It is manufactured by inserting the core material from the opening and thermally welding the opening of the three-side seal bag while evacuating the inside of the bag of the jacket material using a vacuum packaging machine.

  The outer cover material is usually a heat-welded layer made of a thermoplastic resin such as low density polyethylene in the innermost layer, a gas barrier layer made of a material having a barrier property such as an aluminum foil or an aluminum vapor deposited film in the intermediate layer, and an outermost layer in the outer layer. Uses a laminated film obtained by laminating a surface protective layer such as a nylon film or a polyethylene terephthalate film through an adhesive.

  In this case, the atmospheric gas that permeates from the outside air into the vacuum heat insulating material is a component that permeates through the pinholes of the aluminum foil on the surface of the jacket material or the gaps between the vapor deposition layers, and the heat-welded layer on the edge surface of the jacket material. Are classified into two types, that is, a component that penetrates from the exposed portion to the inside through the sealing portion.

  Of these, the thermoplastic resin constituting the heat-welded layer has extremely high gas permeability and moisture permeability compared to the gas barrier layer. Most of the material is transmitted through the sealing portion to the inside from the exposed portion of the heat-welded layer on the end surface of the peripheral edge of the workpiece.

  Therefore, in order to provide a vacuum heat insulating material having excellent heat insulating performance over a long period of time, it is indispensable to suppress the amount of atmospheric gas permeation from the portion where the heat-welded layer on the edge surface of the outer jacket material is exposed. Techniques have been a challenge.

  In response to this problem, there has been reported a vacuum heat insulating material provided with a thin portion in which a part of the heat-welded layer in the sealing portion is thin (see, for example, Patent Document 1).

  FIG. 9 is a cross-sectional view of a conventional vacuum heat insulating material described in Patent Document 1.

  As shown in FIG. 9, in the vacuum heat insulating material 101, a part of the heat welding layer 103 in the sealing portion of the outer covering material 104 having the gas barrier layer 102 and the heat welding layer 103 is thin. The thin-walled portion 105 is formed by using a sealing jig 106 as shown in FIG. 10 to apply a particularly strong pressure to a portion of the jacket material 104 at the sealed portion. It is formed so as to surround the circumference.

In the conventional configuration, the permeation resistance of the gas entering from the end face of the outer periphery of the jacket material is increased by the thin wall portion 105, and it is said that excellent heat insulation performance can be exhibited for a long time by suppressing the gas intrusion into the inside. Yes.
Japanese Utility Model Publication No. 62-141190

  In the configuration of Patent Document 1, although the detailed shape of the jacket material 104 in the thin wall portion 105 is not described, the thin wall portion 105 has corner portions 107 as shown in FIGS. 9 and 10. When the vacuum heat insulating material 101 is manufactured and handled, cracks occur in the outer cover material 104, particularly the gas barrier layer 102, at the corner portion 107. From this crack, there was a problem that the penetration of atmospheric gas components into the vacuum heat insulating material 101 was promoted over time.

  Here, the corner portion 107 refers to the thermal weld layer 103 generated at and near the boundary of the thin portion 105 when the cross section when the sealing portion is cut by a plane perpendicular to the periphery of the outer covering material 104 is seen. This refers to a square-shaped part (a part having a large curvature) formed with a change in thickness.

  The present invention solves the above-mentioned conventional problems, and it is excellent for a long period of time, in which the occurrence of cracks and breakage of the sealed portion are extremely unlikely to occur in and near the thin portion of the heat-welded layer provided in the sealed portion. It aims at providing the vacuum heat insulating material which maintains heat insulation performance.

  In order to achieve the above-described object, the vacuum heat insulating material of the present invention includes two jacket materials that cover the core material by sealing the core material under reduced pressure between the two jacket materials facing the heat-welded layers. In the vacuum heat insulating material in which the outer peripheral portions in the vicinity of the periphery of the outer periphery are thermally welded, a cross section when at least a part of the sealing portion in which the outer peripheral portions of the jacket material are thermally welded is cut along a plane perpendicular to the peripheral edge The heat-welded layer located in the sealing portion has a substantially arc-shaped recess, and the thickness of the heat-welded layer is thinner at the deepest portion of the recess than the peripheral portion of the deepest portion. A thin portion is formed.

  In the above configuration, first, when looking at a cross section when cutting at least a part of the sealing portion in which the peripheral portions of the jacket material are heat-welded with each other in a plane perpendicular to the peripheral portion, the heat-welding layer of the sealing portion By providing a thin portion with a locally thin thickness, the permeation area of gas and moisture entering from the end surface of the outer periphery of the outer cover material is reduced in the thin portion of the heat-welded layer, and the permeation resistance of gas and moisture is increased. In addition, since the permeation rate of gas and moisture is reduced, the amount of gas and moisture that permeate over time is suppressed, and excellent heat insulation performance can be exhibited over a long period of time.

  In addition, when the cross-section when cutting at least a part of the sealing portion in which the peripheral portions of the jacket material are heat-welded is cut by a plane perpendicular to the peripheral portion, the heat-welding layer located in the sealing portion is substantially circular. Since it has an arc-shaped recess, the layer (usually the gas barrier layer) laminated on the outer layer side from the heat-welded layer is in the thin-walled portion of the sealing portion and its vicinity along the shape of the heat-welded layer. The generation of cracks in a layer (usually a gas barrier layer) laminated on the outer layer side from the heat-welded layer is extremely unlikely to bend in an arc shape and form no corners.

  Further, in the thin part of the heat-welded layer, the thickness of the heat-welded layer is thinner than the peripheral part, and the strength is reduced by the thickness reduction, but the concave portion of the heat-welded layer forms a substantially arc shape. In this case, as the thickness of the heat-welded layer gradually increases and decreases along the arc, the strength of the sealing portion also increases and decreases continuously and smoothly. Concentration is unlikely to occur, and cracks in the thin-walled portion of the heat-welded layer and the surrounding jacket material and breakage of the sealing portion are extremely unlikely to occur.

  As described above, it is possible to provide a vacuum heat insulating material that maintains the excellent heat insulating performance for a long period of time, in which the generation of cracks and the breakage of the sealing portion are extremely unlikely to occur in the thin portion of the heat welding layer provided in the sealing portion and in the vicinity thereof.

  According to the present invention, by providing the thin portion where the thickness of the heat-welding layer of the sealing portion is locally thin, the gas and moisture amount entering from the end face of the outer periphery of the outer jacket material are suppressed, and the thermal insulation layer is excellent over a long period of time. Insulation performance can be demonstrated. Moreover, since the heat welding layer located in the sealing portion has a substantially arc-shaped recess, cracks are hardly generated in the layer (usually a gas barrier layer) laminated on the outer layer side from the heat welding layer. Become. Furthermore, it is difficult for external forces to concentrate locally in the thin portion of the heat-welded layer, and cracks and breakage of the sealing portion in the thin-wall portion of the heat-welded layer and the jacket material in the vicinity thereof hardly occur.

  As described above, it is possible to provide a vacuum heat insulating material that maintains the excellent heat insulating performance for a long period of time, in which the generation of cracks and the breakage of the sealing portion are extremely unlikely to occur in the thin portion of the heat welding layer provided in the sealing portion and in the vicinity thereof.

  In the vacuum heat insulating material according to claim 1, the core material is sealed under reduced pressure between the two jacket materials facing each other with the heat-welding layers, and the vicinity of the periphery of the two jacket materials covering the core material In the vacuum heat insulating material in which the outer peripheral portions of the outer cover members were heat-welded, the cross-section when the outer peripheral portions of the jacket material were cut at a part perpendicular to the peripheral edge was cut at least part of the sealing portion. The heat-welded layer located in the sealing portion has a substantially arc-shaped recess, and a thin-walled portion where the thickness of the heat-welded layer is thinner than the peripheral portion of the deepest portion at the deepest portion of the recess. It is formed.

  In the above configuration, first, when looking at a cross section when cutting at least a part of the sealing portion in which the peripheral portions of the jacket material are heat-welded with each other in a plane perpendicular to the peripheral portion, the heat-welding layer of the sealing portion By providing a thin portion with a locally thin thickness, the permeation area of gas and moisture entering from the end surface of the outer periphery of the outer cover material is reduced in the thin portion of the heat-welded layer, and the permeation resistance of gas and moisture is increased. In addition, since the permeation rate of gas and moisture is reduced, the amount of gas and moisture that permeate over time is suppressed, and excellent heat insulation performance can be exhibited over a long period of time.

  In addition, when the cross-section when cutting at least a part of the sealing portion in which the peripheral portions of the jacket material are heat-welded is cut by a plane perpendicular to the peripheral portion, the heat-welding layer located in the sealing portion is substantially circular. Since it has an arc-shaped recess, the layer (usually the gas barrier layer) laminated on the outer layer side from the heat-welded layer is in the thin-walled portion of the sealing portion and its vicinity along the shape of the heat-welded layer. The generation of cracks in a layer (usually a gas barrier layer) laminated on the outer layer side from the heat-welded layer is extremely unlikely to bend in an arc shape and form no corners.

  Here, as a matter of course, it is desirable that corner portions are not formed in the whole sealing portion, not limited to the thin-walled portion and the vicinity thereof.

  Further, in the thin part of the heat-welded layer, the thickness of the heat-welded layer is thinner than the peripheral part, and the strength is reduced by the thickness reduction, but the concave portion of the heat-welded layer forms a substantially arc shape. In this case, as the thickness of the heat-welded layer gradually increases and decreases along the arc, the strength of the sealing portion also increases and decreases continuously and smoothly. Concentration is unlikely to occur, and cracks in the thin-walled portion of the heat-welded layer and the surrounding jacket material and breakage of the sealing portion are extremely unlikely to occur.

  As described above, it is possible to provide a vacuum heat insulating material that maintains the excellent heat insulating performance for a long period of time, in which the generation of cracks and the breakage of the sealing portion are extremely unlikely to occur in the thin portion of the heat welding layer provided in the sealing portion and in the vicinity thereof.

  In addition, since the gas intrusion amount that permeates through the heat-welded layer of the sealing portion from the end surface of the outer covering material is suppressed, the outer periphery of the outer covering material can be offset to the extent that the increase in the permeation resistance of the sealing portion due to the formation of the thin portion Even if the width of the sealing part to be formed is shortened, the heat insulation performance does not deteriorate, so the size of the jacket material used for the vacuum heat insulating material having the same core material can be reduced, and the material cost can be reduced. effective.

  Next, constituent materials of the vacuum heat insulating material will be described.

  The heat welding layer constituting the jacket material is not particularly specified, but a low density polyethylene film, a linear low density polyethylene film, a high density polyethylene film, a medium density polyethylene film, a polypropylene film, a polyacrylonitrile film, etc. These thermoplastic resins or mixed films thereof can be used.

  Here, the thickness of the heat-welded layer that each of the two jacket materials has may be the same or different.

  Moreover, although the material of the heat-welding layer which each of the two jacket materials has may be different, it is desirable that they are the same considering the adhesive strength of the sealing portion.

  The core material is not particularly specified for its type, but is a porous body having a gas layer ratio of about 90%, and is open-celled such as urethane foam, styrene foam, phenol foam, glass wool, rock wool, alumina fiber, Conventionally known core materials such as fiber bodies such as silica-alumina fibers, powders such as pearlite, wet silica, and dry silica can be used.

  The laminate adhesive used for the jacket material is not particularly specified, and conventionally known laminate adhesives such as two-component curable urethane adhesives or epoxy resin adhesives can be used.

  The bag shape of the jacket material is not particularly specified, such as a four-side seal bag, a gusset bag, a three-side seal bag, and a pillow bag.

  Depending on the bag shape of the jacket material, the number of jacket materials covering the core material is one, but in the sealing part near the outer periphery of the jacket material, the two jacket materials facing each other with the heat-welded layers are heated. Since it is welded, the same effect as the present invention can be obtained.

  In addition, a recessed part is a sealing part when seeing the cross section at the time of cut | disconnecting at least one part of the sealing part by which the outer peripheral parts of the jacket material were heat-welded by a plane perpendicular | vertical to the periphery of a jacket material. The position of the heat-welded layer is recessed in a substantially arc shape, and the boundary line (boundary surface) between the heat-welded layer and other layers adjacent to the outside of the heat-welded layer is substantially arc-shaped toward the heat-welded layer side. The curve part which becomes convex is pointed out.

  In addition, the deepest part of a recessed part is the point located in the location where the thickness of the heat welding layer located between the points on the opposing boundary surface among arc-shaped point groups which form the recessed part is the thinnest Refers to the part.

  The invention for a vacuum heat insulating material according to claim 2 is the invention according to claim 1, wherein the heat-welded layer of the sealing portion has a boundary surface with another layer on both sides, and one of the recesses The wave height of the undulation of the boundary surface is larger than the wave height of the undulation of the other boundary surface of the recess.

  In the thin-walled portion and the vicinity thereof, the jacket material on the outer layer side of the heat-welded layer receives stress due to distortion along the shape of the heat-welded layer that is a substantially arc-shaped recess, and the strength decreases.

  Therefore, by making the wave height of the undulation of one boundary surface of the recess larger than the wave height of the undulation of the other boundary surface of the recess, the strength of the outer cover material on the boundary surface side having a relatively small undulation is reduced. Is slightly smaller than the other envelope material on the boundary surface side having a relatively large wave height, and in the sealing portion of the outer envelope material, the outer envelope material having a small strength reduction is the other outer envelope material. The rigidity is maintained in the form of supporting the cracks, and the occurrence of cracks and the breakage of the sealing portion when receiving external force are extremely difficult to occur.

  Here, the wave height of the undulations of the recesses on the same boundary surface may not be constant.

  Here, the constituent material of the other layer of the jacket material adjacent to the heat-welded layer is not particularly specified, but in order to maximize the effect of the present invention, a metal foil or high gas barrier property It is desirable to use a film having

  Further, the layer configuration of the two jacket materials may be different.

  Note that the boundary surface refers to a boundary surface between the heat-welded layer and another layer included in the jacket material adjacent to the heat-welded layer in the sealing portion.

  The wave height refers to the distance between the boundary surface located in the peripheral portion of the recess and a plane parallel to the boundary surface including the deepest portion of the recess.

  The invention for a vacuum heat insulating material according to claim 3 is the invention according to claim 1 or 2, wherein the thermal welding layer of the sealing portion has a boundary surface with another layer on both sides, The deepest part of the part of the boundary surface that is concave on the side of the heat-welding layer is opposed to the deepest part of the part of the concave part that is concave on the side of the heat-welding layer. It is characterized by not doing.

  When there is a thin portion, not only the thickness of the heat-welded layer is thin and the strength is lowered, but also the strength of the jacket material is reduced due to the distortion because the deepest portion of the recess is located.

  In the present invention, the deepest portion of the concave portion on the side of the thermal welding layer on one boundary surface of the concave portion and the deepest portion of the portion of the concave portion on the side of the thermal welding layer on the other boundary surface of the concave portion. By not being opposed to each other, a decrease in strength of the sealing portion where the deepest portion of the concave portion is located is suppressed, and damage or breakage when the sealing portion receives an external force is extremely difficult to occur. At the same time, the effect of suppressing the occurrence of cracks in the gas barrier layer in the recesses is further enhanced.

  The invention of a vacuum heat insulating material according to claim 4 is characterized in that in the invention according to any one of claims 1 to 3, the sealing portion has at least two or more thin portions. Yes.

  In the thin-walled portion, the thickness of the heat-welded layer is thin compared to other portions of the sealing portion, and the sealing strength is reduced, for example, a state in which glass fiber or silica powder as a core material is sandwiched in the manufacturing process When the outer cover material is heat-welded, there is a concern that a heat-welding failure may occur in the thin portion.

  Since there is no resin at the location where the thermal welding failure occurs, the effect of suppressing gas intrusion decreases. As a countermeasure, by providing at least two or more thin-walled portions, the influence of gas and moisture penetration into the vacuum heat insulating material due to poor heat welding is mitigated.

  In particular, when glass fiber is used as the core material, the core material sandwiched during the thermal welding as an interstitial material is often heat-deformed and forms a through hole in the thin portion. The effect becomes more prominent.

  In addition, in the thin part, the strength of the jacket material is lower than the surrounding part, and there is a concern about load concentration when receiving external force, but the load of external force is dispersed due to the presence of multiple thin parts. In addition, generation of cracks in the thin-walled portion and breakage of the sealing portion are extremely difficult to occur.

  In addition, in the case where a plurality of thin portions are provided, the same effect can be obtained even if the thickness of the heat-welded layer in the thin portion is increased compared to the case where there is only one thin portion. The decrease in strength and seal strength is alleviated, and the risk of cracking in the thin-walled portion and breaking of the sealed portion is reduced.

  Further, when the two outer cover materials have both metal foil layers as gas barrier layers, the proximity of the distance between the two metal foil layers in the sealing portion is alleviated. The increase in rate is extremely difficult to occur.

  From this point of view, it is better that the number of thin-walled portions is larger, and it is considered that about 4 to 6 are usually more preferable although it depends on the width of the sealing portion.

  The invention for a vacuum heat insulating material according to claim 5 is the invention according to claim 4, wherein at least a part of the sealing portion positioned between the adjacent thin portions formed in the continuous sealing portion. The thickness of the heat-welded layer is greater than the sum of the thicknesses of the heat-welded layers of the two unsealed portions of the jacket material.

  Usually, when the thin portion is not provided, the thickness of the sealing portion is substantially equal to the sum of the thicknesses of the heat welding layers of the non-sealing portions of the two jacket materials.

  When a plurality of thin portions are formed in the continuous sealing portion, the resin constituting the heat-welded layer at the position of each thin portion moves out of the sealing portion and the sealing portion.

  The thickness of the sealing part located between adjacent thin parts formed in the continuous sealing part is thinner than the sum of the thicknesses of the heat-sealing layers of the two non-sealing parts of the jacket material or In the case of approximately equal, since the resin moving portion is not provided, the load caused by the flow of the resin breaks the other layer adjacent to the heat-welded layer of the outer cover material located in the sealing portion around the thin-walled portion, and the resin The risk of spilling out increases.

  At least a part of the sealing part located between the thin parts provided in the continuous sealing part so as to be thicker than the total thickness of the heat-welded layers of the two non-sealing parts of the jacket material By setting in advance, since the resin escape portion is provided, the load received by the outer cover material of the sealing portion located between the thin-walled portions is relieved, and the outer cover material is hardly broken. To do.

  Also, from the sum of the thicknesses of the heat-welded layers of the two non-sealed portions of the outer cover material between the boundary position between the sealing portion and the non-sealing portion and the thin portion located on the boundary position side It is more desirable to provide a thicker sealing portion.

  In addition, the non-sealing part of a jacket material refers to the location where the jacket material is not heat-welded with the other jacket material.

  The invention of a vacuum heat insulating material according to claim 6 is characterized in that, in the invention according to any one of claims 1 to 5, the core material is made of glass fiber.

  When the core material is glass fiber, a penetrating pinhole from the inside of the vacuum heat insulating material to the jacket material due to the glass fiber is likely to occur.

  Usually, it is effective to increase the thickness of the heat welding layer in the innermost layer of the jacket material facing the inside of the vacuum heat insulating material as a measure for preventing the occurrence of this pinhole, but the thickness of the heat welding layer is increased. As a result, there is a concern that the area of the gas intrusion path in the cross section of the sealing portion is enlarged.

  In the vacuum heat insulating material of the present invention, since the gas intrusion amount can be controlled in the thin wall portion, even if the thickness of the heat welding layer is increased, the inside of the vacuum heat insulating material passes through the sealing portion from the end surface of the outer periphery of the jacket material. An increase in the amount of gas and moisture entering the water is suppressed.

  The invention of a vacuum heat insulating material according to a seventh aspect is characterized in that, in the invention according to any one of the first to sixth aspects, the jacket material has a metal foil layer.

  When a metal foil layer such as an aluminum foil is used as a gas barrier layer for imparting a gas barrier property to the jacket material, the metal foil is more gas barrier than a gas barrier film in which metal atoms and metal oxide molecules are deposited on a resin film. Although it has excellent properties, it is inferior in stretchability and follow-up property, so that cracks and pinholes are likely to occur, and the effects of the present invention are more prominent.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The same reference numerals are given to the same configurations as those of the above-described embodiments, and detailed description thereof will be omitted. The present invention is not limited to the embodiments.

(Embodiment 1)
1 is a cross-sectional view of a vacuum heat insulating material according to Embodiment 1 of the present invention, FIG. 2 is a plan view of the vacuum heat insulating material of the same embodiment, and FIG. 3 is a thin-walled portion of the vacuum heat insulating material of the same embodiment. Sectional drawing which shows an example of the sealing part containing is shown.

  In FIG. 1, a vacuum heat insulating material 1 includes a core material 2, an adsorbent 3 disposed in the core material 2, and two rectangular envelope materials 4 cut to the same dimensions. The core material 2 and the adsorbent 3 are sealed under reduced pressure between the materials 4, and the outer peripheral portions in the vicinity of the peripheral edges of the two jacket materials 4 covering the core material 2 are heat-welded.

  The two jacket materials 4 are formed by laminating a surface protective layer 5, a gas barrier layer 6, and a heat welding layer 7 from the outer layer side. In addition, on the peripheral side (outer peripheral portion) of the jacket material 4, there is a sealing portion 8 in which the heat-welding layers of the jacket material are melted and bonded together, and three of the four sides of the sealing portion 8. Has a thin portion 9.

  Here, the shape of the sealing part 8 around the thin part 9 will be described.

  In FIG. 3, there is a difference in the wave height of the arc-shaped concave portion provided on the boundary surface between the heat welding layer 7 and the gas barrier layer 6, and the concave portion provided on the boundary surface having the concave portion having a large wave height. Only the deepest part is located in the thin part 9.

  Next, in the present embodiment, an example of a method for manufacturing the vacuum heat insulating material 1 of the present embodiment shown in FIGS.

  First, it arrange | positions so that the heat-welding layers 7 of the two jacket | cover materials 4 may oppose, and the three sides of the circumference | surroundings of the jacket | cover_material 4 are heat-welded and it is set as a bag shape. At the time of this thermal welding, the metal heating compression jig 10 (see FIG. 4) and a silicon rubber heater are heated and compressed so as to sandwich the two outer cover materials 4 to form the sealing portion 8 having the shape shown in FIG. To do. Thereafter, the core material 2 and the adsorbent 3 are inserted into the bag, and the vacuum heat insulating material 1 is obtained by thermally welding and sealing the opening of the bag of the jacket material 4 while reducing the pressure inside the bag.

  Here, the two outer jacket materials 4 that are not thermally welded by the heat compression jig 10 are heated and compressed to simultaneously form the sealing portion 8 including the thin wall portion 9. After forming the sealing portion 8 made of a heat-welded layer having a substantially uniform thickness without having a thin portion using a normal flat plate jig, the thin portion is heated and compressed on the sealing portion 8 with the heating compression jig 10. 9 may be formed.

  Moreover, when sealing the bag opening part of the 4th side, in order to seal, reducing the inside of a bag, it is necessary to seal using a vacuum packaging machine.

  Since a normal vacuum packaging machine is equipped with a flat plate heat seal jig, only the bag opening is formed using the vacuum packaging machine after forming the sealing portion 8 made of a heat welding layer having a substantially uniform thickness. You may form the thin part 9 using the heating compression jig 10. FIG.

  The vacuum heat insulating material 1 according to the present embodiment includes two sheets of the core material 2 and the adsorbent 3 that are sealed under reduced pressure between the two rectangular outer cover materials 4 facing each other with the heat-welded layers 7 facing each other. 3 is a vacuum heat insulating material 1 in which the outer peripheral portions of the three sides in the vicinity of the periphery of the jacket material 4 are heat-welded, and the sealing is performed on three sides of the sealing portion 8 in which the outer peripheral portions of the jacket material 4 are heat-welded. When the cross section when the portion 8 is cut by a plane perpendicular to the periphery is viewed, the heat welding layer 7 located in the sealing portion 8 has a substantially arc-shaped recess, and the heat welding is performed at the deepest portion of the recess. A thin portion 9 in which the thickness of the layer 7 is thinner than the peripheral portion of the deepest portion is formed.

  Further, the heat-welding layer 7 of the sealing portion 8 has a boundary surface with another layer (gas barrier layer 6) on both surfaces, and the wave height of the undulation of one boundary surface of the recess is the undulation of the other boundary surface of the recess. Greater than the wave height.

  In addition, the deepest portion of the concave portion on the side of the thermal welding layer on one boundary surface of the concave portion and the deepest portion of the concave portion on the side of the thermal bonding layer on the other boundary surface of the concave portion face each other. Not.

  In the example shown in FIG. 3, the sealing portion 8 has at least two thin portions 9 (four).

  About the vacuum heat insulating material 1 comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

  First, the core material 2 plays a role of forming a fine space as an aggregate of the vacuum heat insulating material 1, forms a heat insulating portion of the vacuum heat insulating material 1 after evacuation, and is made of glass fiber.

  The adsorbent 3 serves to adsorb and remove residual gas components released into the vacuum heat insulating material 1 from the fine gaps of the core material 2 after vacuum packaging, and moisture and gas that enter the vacuum heat insulating material 1. .

  The jacket material 4 is obtained by laminating a thermoplastic resin, a metal foil having a gas barrier property, a resin film, or the like, and plays a role of suppressing atmospheric gas intrusion into the vacuum heat insulating material 1 from the outside.

  The surface protective layer 5 serves to prevent the outer cover material 4, particularly the gas barrier layer 6 from being damaged or torn from an external force, located on the outer layer side of the gas barrier layer 6 among the layers of the outer cover material.

  As the surface protective layer 5, a conventionally known material such as a nylon film, a polyethylene terephthalate film, or a polypropylene film can be used, and one type or two or more types may be used.

  The gas barrier layer 6 is a layer composed of one or more kinds of films having high barrier properties, and imparts excellent gas barrier properties to the jacket material 4.

  As the gas barrier layer 6, metal foil such as aluminum foil, copper foil, stainless steel foil, polyethylene terephthalate film, ethylene-vinyl alcohol copolymer film, metal atoms such as aluminum or copper, or metal oxide such as alumina or silica are used. A vapor-deposited film, a film in which a metal atom or metal oxide is vapor-deposited, or the like can be used.

  The thermal welding layer 7 welds the jacket materials 4 to each other, and in addition to the role of maintaining the vacuum inside the vacuum heat insulating material 1, the gas barrier from the piercing from the inside of the vacuum heat insulating material 1 by the core material 2 and the adsorbent 3, etc. It serves to protect the layer 6.

  The sealing portion 8 is configured by welding the heat welding layers 7 of the jacket material 4, and plays a role of blocking the inside and the outside of the vacuum heat insulating material 1.

  The thin-walled portion 9 serves to maintain the vacuum degree of the vacuum heat insulating material 1 by suppressing the permeation rate of atmospheric gas that enters the vacuum heat insulating material 1 through the sealing portion 8 from the end surface of the outer periphery of the jacket material 4. Yes.

  As described above, in the present embodiment, the thin-walled portion 9 is provided at the deepest position of the substantially arc-shaped concave portion included in the boundary surface between the heat welding layer 7 and the gas barrier layer 6 in the sealing portion 8. Since there is a difference in the wave heights of the recesses on the boundary surface of the layers, the gas barrier layer 6 and the jacket material 4 are extremely unlikely to deteriorate and break, and the atmospheric gas intrusion into the vacuum heat insulating material 1 with time Is suppressed.

  Moreover, when the vacuum heat insulating material 1 is produced by the above-described manufacturing method, the heat-welded layer 7 is usually heated and compressed by the superheated compression jig 10 constituted by the protruding portions 11 having an arcuate curved surface as shown in FIG. 10 is applied to the direction perpendicular to the tangent line of the arc of the protrusion 11, the resin of the heat-welded layer 7 easily flows toward both ends of the thin portion 9. Compared with the case where the flat portion such as the conventional sealing jig 106 is compressed, the temperature condition and pressure condition at the time of manufacturing when the same thin portion 9 is obtained are relaxed, and the gas barrier layer 6 and Deterioration of the jacket material 4 is suppressed.

  In other words, under the same molding conditions, the thickness of the thin portion 9 of the heat-welded layer 7 can be further reduced, and the amount of gas and moisture intrusion from the end surface of the outer periphery of the outer cover material 4 can be easily suppressed.

  The vacuum heat insulating material 1 according to the present embodiment includes two sheets of the core material 2 and the adsorbent 3 that are sealed under reduced pressure between the two rectangular outer cover materials 4 facing each other with the heat-welded layers 7 facing each other. 3 is a vacuum heat insulating material 1 in which the outer peripheral portions of the three sides in the vicinity of the periphery of the jacket material 4 are heat-welded, and the sealing is performed on three sides of the sealing portion 8 in which the outer peripheral portions of the jacket material 4 are heat-welded. When the cross section when the portion 8 is cut by a plane perpendicular to the periphery is viewed, the heat welding layer 7 located in the sealing portion 8 has a substantially arc-shaped recess, and the heat welding is performed at the deepest portion of the recess. A thin portion 9 in which the thickness of the layer 7 is thinner than the peripheral portion of the deepest portion is formed.

  In the above-described configuration, first, when a cross-section when cutting at least a part of the sealing portion 8 where the peripheral portions of the jacket material 4 are heat-welded is cut by a plane perpendicular to the peripheral portion, the heat of the sealing portion 8 is obtained. By providing the thin portion 9 where the thickness of the welding layer 7 is locally thin, the gas and moisture permeation cross-sectional area entering from the end face of the outer periphery of the outer cover material 4 is reduced in the thin portion 9 of the heat welding layer 7. Since the permeation resistance of gas and moisture is increased and the permeation rate of gas and moisture is reduced, the amount of gas and moisture that permeate with time is suppressed, and excellent heat insulation performance can be exhibited over a long period of time.

  Moreover, when the cross section at the time of cut | disconnecting at least one part of the sealing part 8 by which the peripheral parts of the jacket material 4 were heat-welded by a plane perpendicular | vertical to a peripheral part was seen, the heat welding layer located in the sealing part 8 7 has a substantially arc-shaped recess, the layer (gas barrier layer 6) laminated on the outer layer side of the heat-welded layer 7 is the thin-walled portion 9 of the sealing portion 8 and the vicinity thereof. In this way, the generation of cracks in the layer (gas barrier layer 6) laminated on the outer layer side from the heat-welded layer 7 is extremely difficult to occur without forming a corner portion by bending in a circular arc shape.

  Here, as a matter of course, it is desirable that corner portions are not formed in the entire sealing portion 8, not limited to the thin-walled portion 9 and the vicinity thereof.

  Further, in the thin-walled portion 9 of the heat-welded layer 7, the thickness of the heat-welded layer 7 is thinner than the peripheral portion, and the strength is reduced by the thickness reduction, but the concave portion of the heat-welded layer 7 has a substantially arc shape. When formed, the strength (bending strength, etc.) of the sealing portion 8 also increases and decreases smoothly and continuously as the position changes as the thickness of the heat welding layer 7 gradually increases and decreases along the arc. Therefore, it is difficult for external force to concentrate locally in the thin portion 9 of the heat-welded layer 7, and cracks in the thin-wall portion 9 of the heat-welded layer 7 and the jacket material 4 in the vicinity thereof and breakage of the sealing portion 8 are caused. Is extremely difficult to occur.

  By the above, the vacuum heat insulating material which maintains the heat insulation performance excellent in the long term in which the crack generation | occurrence | production and the fracture | rupture of the sealing part 8 do not occur easily in the thin part 9 of the heat welding layer 7 provided in the sealing part 8 and its vicinity. 1 can be provided.

  Further, in the vacuum heat insulating material 1 of the present embodiment, the heat welding layer 7 of the sealing portion 8 has a boundary surface with another layer (gas barrier layer 6) on both surfaces, and the undulation of one boundary surface of the concave portion The wave height is larger than the wave height of the undulation of the other boundary surface of the recess.

  In the thin-walled portion 9 and the vicinity thereof, the covering material 4 (each of the layers 6 and 5) on the outer layer side of the heat-welding layer 7 is distorted along the shape of the heat-welding layer 7 that is a substantially arc-shaped recess. Due to the stress caused by, the strength decreases.

  Therefore, by making the wave height of the undulation of the boundary surface on one side (upper side in FIG. 1) of the concave portion larger than that of the boundary surface on the other side (lower side in FIG. 1), the wave height is relatively small. The lowering of the strength of the outer cover material 4 on the boundary surface side having waviness (lower side in FIG. 1) In comparison with the sealing portion 8 of the outer covering material 4, the outer covering material 4 (lower in FIG. 1) supports the other outer covering material 4 (upper in FIG. 1). The rigidity is maintained in the shape, and the occurrence of cracks and breakage of the sealing portion 8 when receiving external force are extremely difficult.

  When the thin-walled portion 9 is present, not only the thickness of the heat-welded layer 7 is thin and the strength is reduced, but also the strength of the jacket material 4 is reduced due to the distortion due to the deepest portion of the recess being located.

  In the present embodiment, the deepest portion of the concave portion on the heat welding layer 7 side of one boundary surface (upper side in FIG. 1) and the other boundary (lower side in FIG. 1) of the concave portion. Since the deepest portion of the concave portion on the surface of the surface is not opposed to the deepest portion, a decrease in strength of the sealing portion 8 where the deepest portion of the concave portion is located is suppressed, and the sealing portion 8 has an external force. Scratches and breakage are less likely to occur. At the same time, the effect of suppressing the occurrence of cracks in the gas barrier layer 6 in the recesses is further enhanced.

  Moreover, it is preferable that the sealing part 8 has at least two thin parts 9 as in the example shown in FIG.

  In the thin portion 9, the thickness of the heat-welded layer 7 is thinner than that of the other portion of the sealing portion 8, and the sealing strength is reduced. For example, glass fiber or silica powder that is the core material 2 in the manufacturing process When the outer cover material 4 is heat-welded in a state where the material is sandwiched, there is a concern that a poor heat-welding occurs in the thin portion 9.

  Since there is no resin at the location where the thermal welding failure occurs, the effect of suppressing gas intrusion decreases. As a countermeasure, by providing at least two or more thin-walled portions 9, the influence of gas and moisture intrusion promotion into the vacuum heat insulating material 1 due to poor heat welding is mitigated.

  In particular, when glass fiber is used as the core material 2, the core material 2 material sandwiched at the time of heat welding as an interstitial material is often heat-deformed and forms a through hole in the thin portion 9. The effect (of the present embodiment) of the present invention becomes more remarkable.

  Moreover, in the thin part 9, although the intensity | strength of the jacket material 4 becomes lower than a surrounding part and there is a concern about the load concentration at the time of receiving external force, the load of external force is due to the presence of a plurality of thin parts 9. Are dispersed, and the occurrence of cracks in the thin-walled portion 9 and the breakage of the sealing portion 8 are extremely difficult to occur.

  Further, when the plurality of thin portions 9 are provided, the same effect can be obtained even if the thickness of the thermal welding layer 7 in the thin portion 9 is increased as compared with the case where only one thin portion 9 is provided. 9 is reduced, and the risk of cracks in the thin-walled portion 9 and breakage of the sealing portion 8 is reduced.

  In the present embodiment, the sealing portion 8 having the thin portion 9 has three sides, but may be provided on four sides of the entire circumference of the sealing portion 8.

  In addition, the thickness of the heat welding layer 7 in each thin part 9 does not need to be the same.

  In the present embodiment, as shown in FIG. 2, the thin portions 9 are orthogonal, but the thin portions 9 do not have to intersect.

  In addition, the curvature radius of the recessed part of the interface located in each thin part 9 does not need to be the same, The metal foil and film used as the gas barrier layer 6 should just have a curvature radius of the grade which does not deteriorate. .

  In addition, the space | interval of the thin part 9 is not specified in particular, and as shown in FIG. 5, the space | interval of the recessed parts which a boundary surface does not need to be equal.

  In the present embodiment, the position of the thin-walled portion 9 is not particularly specified, but the position of the concave portion on the boundary surface exists at the boundary between the sealing portion 8 of the jacket material 4 and the portion that is not. In such a case, the resin on one side of the thin-walled portion 9 is not sufficiently heated, and the fluidity of the resin is poor.

  Hereinafter, the detailed shape of the thin part 9 and the effect in this invention are demonstrated using an Example.

Example 1
In the first embodiment, a linear low density polyethylene film having a thickness of 50 μm is used as the heat welding layer 7, an aluminum foil having a thickness of 6 μm is used as the gas barrier layer 6, and two nylon films having a thickness of 15 μm and 25 μm are used as the surface protective layer 5. A vacuum heat insulating material 1 composed of a laminated jacket material 4, a core material 2 made of glass fiber, and an adsorbent 3 made of calcium oxide was produced.

  On the peripheral side (outer peripheral portion) of the jacket material 4, there is a sealing portion 8 in which the heat-welding layers 7 of the jacket material 4 are melted and bonded together, and three of the four sides of the sealing portion 8. Four groove-shaped thin portions 9 parallel to the peripheral edge are formed in a direction perpendicular to the peripheral edge, and one of the thin wall portions 9 (in FIG. 3, the upper gas barrier layer 6 and the thermal welding layer 7 are positioned). The radius of curvature at the deepest part of the concave portion of the boundary surface is 1.5 mm, each wave height of the undulation of the boundary surface (in FIG. 3 between the upper gas barrier layer 6 and the thermal welding layer 7) is 0.2 mm, and The distance between adjacent deepest portions was 1.5 mm. Further, the maximum wave height of the concave portion of the other interface (in FIG. 3, the lower gas barrier layer 6 and the heat welding layer 7) was 0.05 mm (see FIG. 3).

At this time, when the seal width (width for thermally welding the jacket materials 4) is 20 mm and the thickness of the thin portion 9 is 10 μm, the sealing portion 8 is removed from the end surface of the outer periphery of the jacket material 4 of the vacuum heat insulating material 1. The amount of atmospheric gas entering through was 9.5 × 10 ⁻¹⁵ mol / m ² / s / Pa.

  Moreover, in the sealing part 8, generation | occurrence | production of the crack was not confirmed in the aluminum foil.

  In Example 1, the core material 2 consists of glass fiber.

  When the core material 2 is a glass fiber, a penetrating pinhole from the inside of the vacuum heat insulating material 1 to the jacket material 4 due to the glass fiber is likely to occur.

  Usually, as a measure for preventing the occurrence of pinholes, it is effective to increase the thickness of the heat welding layer 7 in the innermost layer of the jacket material 4 facing the inside of the vacuum heat insulating material 1. By increasing the thickness, there is a concern that the passage cross-sectional area of the gas intrusion path that enters through the sealing portion 8 from the end face of the outer periphery of the outer cover material 4 increases.

  In the vacuum heat insulating material 1 of the first embodiment (Example 1), since the gas penetration amount can be controlled in the thin portion 9, the end surface of the outer periphery of the outer cover material 4 even if the thickness of the heat welding layer 7 is increased. Increase in the amount of gas and moisture entering from the inside through the sealing portion 8 to the inside is suppressed.

  Moreover, in Example 1, although aluminum foil (metal foil) was employ | adopted as a gas barrier layer for providing gas-barrier property to the jacket material 4, a metal foil vapor-deposits a metal atom and a metal oxide molecule on a resin film. Although the gas barrier property is excellent as compared with the gas barrier film, the stretchability and followability are inferior, so that cracks and pinholes are likely to occur, and the effect of the present invention (Embodiment 1) appears more remarkably.

(Example 2)
In the first embodiment, a linear low density polyethylene film having a thickness of 50 μm is used as the heat welding layer 7, an aluminum foil having a thickness of 6 μm is used as the gas barrier layer 6, and two nylon films having a thickness of 15 μm and 25 μm are used as the surface protective layer 5. A vacuum heat insulating material 1 composed of a laminated jacket material 4, a core material 2 made of glass fiber, and an adsorbent 3 made of calcium oxide was produced.

  On the peripheral side (outer peripheral portion) of the jacket material 4, there is a sealing portion 8 in which the heat-welding layers 7 of the jacket material 4 are melted and bonded together, and three of the four sides of the sealing portion 8. Four groove-shaped thin portions 9 parallel to the peripheral edge are formed in a direction perpendicular to the peripheral edge, and one of the thin wall portions 9 (in FIG. 3, the upper gas barrier layer 6 and the thermal welding layer 7 are positioned). The radius of curvature at the deepest part of the concave portion of the boundary surface is 1.5 mm, each wave height of the undulation of the boundary surface (in FIG. 3 between the upper gas barrier layer 6 and the thermal welding layer 7) is 0.2 mm, and The distance between adjacent deepest portions was 1.5 mm. Further, the maximum wave height of the concave portion of the other interface (in FIG. 3, the lower gas barrier layer 6 and the heat welding layer 7) was 0.05 mm (see FIG. 3).

At this time, when the seal width (the width for heat-sealing the outer cover materials 4) is 20 mm and the thickness of the thin portion 9 is 5 μm, the sealing portion 8 is removed from the end surface of the outer periphery of the outer cover material 4 of the vacuum heat insulating material 1. The amount of atmospheric gas entering through was 8.0 × 10 ⁻¹⁵ mol / m ² / s / Pa.

  Moreover, in the sealing part 8, generation | occurrence | production of the crack was not confirmed in the aluminum foil.

(Example 3)
In the first embodiment, a linear low density polyethylene film having a thickness of 50 μm is used as the heat welding layer 7, an aluminum foil having a thickness of 6 μm is used as the gas barrier layer 6, and two nylon films having a thickness of 15 μm and 25 μm are used as the surface protective layer 5. A vacuum heat insulating material 1 composed of a laminated jacket material 4, a core material 2 made of glass fiber, and an adsorbent 3 made of calcium oxide was produced.

  On the peripheral side (outer peripheral portion) of the jacket material 4, there is a sealing portion 8 in which the heat-welding layers 7 of the jacket material 4 are melted and bonded together, and three of the four sides of the sealing portion 8. Four groove-shaped thin portions 9 parallel to the peripheral edge are formed in a direction perpendicular to the peripheral edge, and one of the thin wall portions 9 (in FIG. 3, the upper gas barrier layer 6 and the thermal welding layer 7 are positioned). The radius of curvature at the deepest part of the concave portion of the boundary surface is 1.5 mm, each wave height of the undulation of the boundary surface (in FIG. 3 between the upper gas barrier layer 6 and the thermal welding layer 7) is 0.2 mm, and The distance between adjacent deepest portions was 1.5 mm. Further, the maximum wave height of the concave portion of the other interface (in FIG. 3, the lower gas barrier layer 6 and the heat welding layer 7) was 0.05 mm (see FIG. 3).

At this time, when the seal width (the width for thermally welding the jacket materials 4) is 20 mm and the thickness of the thin portion 9 is 20 μm, the sealing portion 8 is formed from the end surface of the outer periphery of the jacket material 4 of the vacuum heat insulating material 1. The amount of atmospheric gas entering through was 1.0 × 10 ⁻¹⁴ mol / m ² / s / Pa.

  Moreover, in the sealing part 8, generation | occurrence | production of the crack was not confirmed in the aluminum foil.

Example 4
In the first embodiment, a linear low density polyethylene film having a thickness of 50 μm is used as the heat welding layer 7, an aluminum foil having a thickness of 6 μm is used as the gas barrier layer 6, and two nylon films having a thickness of 15 μm and 25 μm are used as the surface protective layer 5. A vacuum heat insulating material 1 composed of a laminated jacket material 4, a core material 2 made of glass fiber, and an adsorbent 3 formed by enclosing calcium oxide in a ventilation wrapping material was produced.

  On the peripheral side (outer peripheral part) of the jacket material 4, there is a sealing part 8 in which the heat-welding layers 7 of the jacket material 4 are melted and bonded together, and three of the four sides of the sealing part 8 Three groove-shaped thin portions 9 parallel to the peripheral edge are formed in a direction perpendicular to the peripheral edge, and one of the thin-walled portions 9 (in FIG. 6, the upper gas barrier layer 6 and the thermal welding layer 7 are arranged). The radius of curvature at the deepest part of the concave portion of the boundary surface is 1.5 mm, each wave height of the waviness of the boundary surface (in FIG. 6 between the upper gas barrier layer 6 and the thermal welding layer 7) is 0.2 mm, and The distance from the deepest part of the adjacent recesses was 1.5 mm. Further, the maximum wave height of the concave portion of the other interface (in FIG. 6, the lower gas barrier layer 6 and the heat-welded layer 7) was 0.05 mm (see FIG. 6).

At this time, when the seal width (width for thermally welding the jacket materials 4) is 20 mm and the thickness of the thin portion 9 is 10 μm, the sealing portion 8 is removed from the end surface of the outer periphery of the jacket material 4 of the vacuum heat insulating material 1. The amount of atmospheric gas entering through was 1.0 × 10 ⁻¹⁴ mol / m ² / s / Pa.

  Moreover, in the sealing part 8, generation | occurrence | production of the crack was not confirmed in the aluminum foil.

(Example 5)
In the first embodiment, a linear low density polyethylene film having a thickness of 50 μm is used as the heat welding layer 7, an aluminum foil having a thickness of 6 μm is used as the gas barrier layer 6, and two nylon films having a thickness of 15 μm and 25 μm are used as the surface protective layer 5. A vacuum heat insulating material 1 composed of a laminated jacket material 4, a core material 2 made of glass fiber, and an adsorbent 3 formed by enclosing calcium oxide in a ventilation wrapping material was produced.

  On the peripheral side (outer peripheral part) of the jacket material 4, there is a sealing part 8 in which the heat-welding layers 7 of the jacket material 4 are melted and bonded together, and three of the four sides of the sealing part 8 A groove-like thin portion 9 parallel to the peripheral edge is formed in the direction perpendicular to the peripheral edge, and one of the thin wall portions 9 (in FIG. 7, the upper gas barrier layer 6 and the thermal welding layer 7 are positioned). The radius of curvature at the deepest part of the concave portion of the boundary surface is 1.5 mm, each wave height of the waviness of the boundary surface (in FIG. 7 between the upper gas barrier layer 6 and the thermal welding layer 7) is 0.2 mm, and The distance from the deepest part of the adjacent recesses was 1.5 mm. Further, the maximum wave height of the concave portion of the other interface (in FIG. 7, the lower gas barrier layer 6 and the heat-welded layer 7) was 0.05 mm (see FIG. 7).

At this time, when the seal width (width for thermally welding the jacket materials 4) is 20 mm and the thickness of the thin portion 9 is 10 μm, the sealing portion 8 is removed from the end surface of the outer periphery of the jacket material 4 of the vacuum heat insulating material 1. The amount of atmospheric gas entering through was 8.6 × 10 ⁻¹⁵ mol / m ² / s / Pa.

  Moreover, in the sealing part 8, generation | occurrence | production of the crack was not confirmed in the aluminum foil.

(Comparative Example 1)
An outer sheath formed by laminating a linear low-density polyethylene film having a thickness of 50 μm as the heat welding layer 7, an aluminum foil having a thickness of 6 μm as the gas barrier layer 6, and two nylon films having a thickness of 15 μm and 25 μm as the surface protective layer 5. A vacuum heat insulating material composed of a material 4, a core material 2 made of glass fiber, and an adsorbent 3 formed by enclosing calcium oxide in a ventilation wrapping material was produced.

When the thickness of the heat-welding layer 7 in the sealing part 8 is substantially uniform 100 μm, the amount of atmospheric gas entering through the sealing part 8 from the end surface of the outer periphery 4 of the vacuum heat insulating material 1 is 2.0 ×. It was 10 ⁻¹⁴ mol / m ² / s / Pa.

  Moreover, in the sealing part 8, generation | occurrence | production of the crack was not confirmed in the aluminum foil.

(Comparative Example 2)
An outer sheath formed by laminating a linear low-density polyethylene film having a thickness of 50 μm as the heat welding layer 7, an aluminum foil having a thickness of 6 μm as the gas barrier layer 6, and two nylon films having a thickness of 15 μm and 25 μm as the surface protective layer 5. A vacuum heat insulating material composed of the material 4, the core material 2 made of glass fiber, and the adsorbent 3 made of calcium oxide was produced.

  On the peripheral side (outer peripheral part) of the jacket material 4, there is a sealing part 8 in which the heat-welding layers 7 of the jacket material 4 are melted and bonded together, and three of the four sides of the sealing part 8 Four groove-shaped thin portions 9 are formed in parallel to the peripheral edge in a direction perpendicular to the peripheral edge, and the concave portion of the boundary surface (the gas barrier layer 6 and the thermal welding layer 7) is located in each thin portion 9 The heat-welded layer 7 had a substantially uniform thickness of 10 μm, and had corner portions 12 at the boundaries of the thin-walled portions 9 (see FIG. 8).

At this time, the seal width (the width at which the jacket materials 4 are thermally welded) is 20 mm, and the amount of atmospheric gas that enters through the sealing portion 8 from the end surface of the outer periphery of the jacket material 4 of the vacuum heat insulating material 1 is estimated. 9.5 × 10 ⁻¹⁵ mol / m ² / s / Pa.

  However, since the boundary portion of the thin portion 9 has the corner portion 12, the occurrence of cracks in the aluminum foil at the corner portion 12 was confirmed.

  As mentioned above, the Example and the comparative example in this invention are shown in (Table 1).

  However, the deterioration of the jacket material 4 in (Table 1) was determined according to the following criteria.

○: No deterioration (No increase in pinholes was confirmed in the aluminum foil located in the thin part)
X: Deteriorated (an increase in pinholes was confirmed in the aluminum foil located in the thin part)
From the results of (Table 1), the vacuum heat insulating material 1 provided with the thin-walled portion 9 shown in the first embodiment does not have the thin-walled portion 9 although there is a difference in effect depending on the thickness of the thin-walled portion 9 and the number of concave portions. There was always a significant difference compared to vacuum insulation. Moreover, deterioration of the jacket material 4 was not confirmed.

  The vacuum heat insulating material according to the present invention has a heat insulating performance that can withstand long-term use, such as a refrigerator heat insulating material, a vending machine, a building heat insulating material, an automotive heat insulating material, a cold insulation box, and the like. It can also be applied to.

Sectional drawing of the vacuum heat insulating material in Embodiment 1 of this invention The top view of the vacuum heat insulating material in Embodiment 1 of this invention Sectional drawing which shows an example of the sealing part containing the thin part of the vacuum heat insulating material in Embodiment 1 of this invention Sectional drawing which shows an example of the heating compression jig of the vacuum heat insulating material in Embodiment 1 of this invention Sectional drawing which shows the modification of the sealing part containing the thin part of the vacuum heat insulating material in Embodiment 1 of this invention. Sectional drawing of the sealing part containing the thin part of the vacuum heat insulating material in Example 4 Sectional drawing of the sealing part containing the thin part of the vacuum heat insulating material in Example 5 Sectional drawing of the sealing part containing the thin part of the vacuum heat insulating material in the comparative example 2 Cross section of conventional vacuum insulation Sectional drawing which shows the state which forms the thin part with the heating compression jig of the conventional vacuum heat insulating material

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vacuum heat insulating material 2 Core material 4 Cover material 6 Gas barrier layer 7 Heat welding layer 8 Sealing part 9 Thin part

Claims (7)

In a vacuum heat insulating material in which a core material is sealed under reduced pressure between two outer cover materials facing each other with the heat-welding layers, and outer peripheral portions in the vicinity of the peripheral edges of the two outer cover materials covering the core material are heat-welded. The heat-welded layer located on the sealing portion when a cross-section when cutting at least a part of the sealing portion on which the outer peripheral portions of the jacket material are heat-welded is cut by a plane perpendicular to the peripheral edge Has a substantially arc-shaped concave portion, and a thin-walled portion in which the thickness of the heat-welded layer is thinner than the peripheral portion of the deepest portion is formed in the deepest portion of the concave portion. The heat-sealed layer of the sealing portion has a boundary surface with another layer on both surfaces, and the wave height of the undulation of one boundary surface of the concave portion is higher than the wave height of the undulation of the other boundary surface of the concave portion. The vacuum heat insulating material according to claim 1, which is also large. The heat-welded layer of the sealing portion has a boundary surface with another layer on both surfaces, and the deepest portion of a portion recessed on the heat-welded layer side of the one boundary surface of the recess, The vacuum heat insulating material according to claim 1 or 2, wherein a deepest portion of a concave portion on the heat welding layer side of the other boundary surface of the concave portion is not opposed. The vacuum heat insulating material according to any one of claims 1 to 3, wherein the sealing portion includes at least two thin portions. The thickness of the heat welding layer of at least a part of the sealing part located between the adjacent thin parts formed in the continuous sealing part is the non-sealing part of the two outer cover materials. The vacuum heat insulating material of Claim 4 which is thicker than the sum total of the thickness of the said heat welding layer which has. The said heat insulating material consists of glass fiber, The vacuum heat insulating material as described in any one of Claim 1 to 5 characterized by the above-mentioned. The vacuum heat insulating material according to any one of claims 1 to 6, wherein the jacket material has a metal foil layer.