JP2017116097A - Method for manufacturing vacuum heat insulation material and vacuum heat insulation material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for easily and economically manufacturing a vacuum heat insulation material in which a decrease in degree of vacuum is suppressed in long-term use, and a vacuum heat insulating material in which a decrease in a degree of vacuum is suppressed in long-term use.SOLUTION: The present invention relates to a method of manufacturing vacuum heat insulation materials 100A-I, 100A-II, in which a frame-like welded part is formed by welding of a thermally welded layer 1, and a core material 4 is decompressed and sealed in an outer cover material 3. The method has each step of: 1) storing the core material inside the outer cover material having a non-welded part; 2) after 1), welding a part of the non-welded part beforehand (X1), or without welding, welding the thermally welded layer under reduced pressure so that the whole non-welded part is welded, wherein, heat welding is performed to leave an end part having a predetermined width from the outer edge of the outer cover material in which the core material is stored; 3) cleaning the surface of the facing thermally welded layer at the end part 7 of the outer cover material left on an outside of a welded part X2 thermally welded after storing the core material, and 4I) thermally welding the cleaned thermally welded layer to form a protective welded part Y.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for manufacturing a vacuum heat insulating material and a vacuum heat insulating material.

  Normally, a vacuum insulation material is a porous core material in which powders such as glass fiber and silica are hardened, and is loaded into a bag-like outer jacket material having an airtightness and a heat-welded layer on the inner surface, and is removed under reduced pressure. It is produced by heat-sealing or the like by heat-welding the heat-welding layers in the outer portion of the outer periphery of the core material, that is, the portion where the core material does not exist.

  In this case, when the core material is loaded into the bag-shaped outer cover material, dust is generated by the core material coming into contact with the outer cover material at the opening of the outer cover material, and the dust is thermally welded near the opening. May adhere to the layer. When heat sealing is performed as described above in this state, a seal portion in which dust is sandwiched is formed in the vicinity of the opening.

  The vacuum heat insulating material obtains high heat insulation by reducing the pressure inside, but if dust exists in the seal part as described above, there is an example in which the degree of vacuum decreases during long-term use and the heat insulating performance decreases. It was a problem.

  In order to solve such a problem, for example, Patent Document 1 describes a technique for reducing the sealing failure by increasing the width of the seal portion as follows. That is, the seal portion of the vacuum heat insulating material is usually provided in a frame shape at an appropriate distance from the outer periphery of the core material on the outer portion of the outer periphery of the stored core material. Therefore, the region from the outer periphery of the core member to the outer periphery toward the inner periphery of the seal portion is an unsealed region that is not sealed. In patent document 1, the width | variety of a seal part is made wide by carrying out the heat welding of such a non-seal area | region in non-contact.

  However, in the above method, the amount of dust sandwiched between the seal portions is not reduced, and the reduction in the degree of vacuum in the vacuum heat insulating material cannot be sufficiently suppressed.

  In addition, for example, the entire core material is covered with a non-woven fabric that is air permeable but does not allow the powder to pass from the core material (see, for example, Patent Document 2), or an opening in a bag-shaped outer jacket material A method has been proposed in which a filter that allows air to pass through but does not allow powder to pass therethrough (see, for example, Patent Document 3) prevents the powder from being caught in the seal portion of the vacuum heat insulating material.

  However, in the above method, since an extra process or material is added to the manufacturing process of the vacuum heat insulating material, it causes a cost increase, or when the entire core material is covered with a nonwoven fabric, a hole is formed in the core material. There was a drawback that it was difficult to handle specially shaped products such as opening the door.

JP 2007-182997 A Japanese Patent No. 5394474 Japanese Patent No. 5161781

  The present invention has been made from the above viewpoint, and a method for easily and economically manufacturing a vacuum heat insulating material in which a decrease in vacuum degree is suppressed in long-term use and a decrease in vacuum degree in long-term use are suppressed. It aims at providing a vacuum heat insulating material.

The present invention has the following configuration.
[1] A vacuum heat insulating material having a jacket material in which a film having a heat-welded layer and an airtight layer is arranged so that the heat-welded layers face each other, and a core material housed inside the jacket material. The jacket material has a welded portion in which the heat-welded layers are heat-welded with a predetermined width over the entire periphery of the core material, and a protective welded portion formed on the outside of the welded portion. A method for producing a vacuum heat insulating material in a reduced pressure state,
A step of storing the core material in the outer cover material having an unwelded portion in which the portion to be the welded portion is not welded in the welded portion;
About the jacket material containing the core material, the heat-welded layers of the unwelded portions are heat-welded in advance, leaving a part necessary for decompression, or without heat-welding, It is a step of heat-welding the heat-welded layers under reduced pressure so that the whole is in a welded state, and for any of the heat-welded, a predetermined width from the outer edge of the jacket material containing the core material A process to be performed leaving the edge,
Cleaning the surface of the opposing heat-welded layer at the end of the outer cover material that is left outside the post-storage welded portion that has been heat-welded after the core material is stored; A step of forming the cleaned heat-welded layers on the outside of the post-welded portion so as to have a region where heat-welded with each other;
The manufacturing method of the vacuum heat insulating material which has this.
[2] The vacuum heat insulating material has a protective welding part formed on the outside of the welding part so as to partially overlap at least a part of the welding part, and the step of forming the protective welding part includes: The protective welding portion is a step of forming a predetermined overlapping width inward from the outer side of the post-storage welding portion and having a region where the cleaned heat welding layers are thermally welded to each other. [1 ] The manufacturing method of the vacuum heat insulating material.
[3] The method for producing a vacuum heat insulating material according to [1] or [2], wherein the core material is a compression molded body including powder and a fiber body.
[4] The method for producing a vacuum heat insulating material according to [2] or [3], wherein an overlap width between the protective welded portion and the post-storage welded portion is 1 to 5 mm.
[5] A jacket material in which a film having a heat-welded layer and an airtight layer is arranged so that the heat-welded layers face each other, and a core material housed in a reduced pressure state inside the jacket material, The jacket material is a vacuum heat insulating material having a seal portion in which the heat-welded layers are in close contact with each other by thermal welding in a region covering the entire periphery of the core material outside the outer periphery of the core material,
A vacuum heat insulating material in which at least a part of the seal portion has a smaller dust amount of the core material sandwiched by the seal portion in an outer region than in an inner region of the seal portion.
[6] The vacuum heat insulating material according to [5], wherein the core material is a compression molded body including powder and a fiber body.

  ADVANTAGE OF THE INVENTION According to this invention, the vacuum heat insulating material by which the fall of the vacuum degree was suppressed in long-term use can be manufactured easily and economically. Moreover, the vacuum heat insulating material by which the fall of the vacuum degree was suppressed in long-term use can be provided.

It is a figure which shows typically an example of the manufacturing method of this invention. It is a figure which shows typically another example of the manufacturing method of this invention. It is a top view which shows the jacket material in which the core material was accommodated in an example of the manufacturing method shown in FIG. It is sectional drawing in the AA of the jacket material in which the core material shown to FIG. 3A was accommodated. It is a top view which shows the jacket material (vacuum heat insulating material precursor) by which the core material was accommodated and vacuum-welded in the example of the manufacturing method shown in FIG. It is sectional drawing in the BB line of the jacket material (vacuum heat insulating material precursor) by which the core material shown to FIG. 4A was accommodated and it pressure-welded. It is a top view which shows vacuum heat insulating material 100A-I manufactured in an example of the manufacturing method shown in FIG. It is sectional drawing in CC line of the vacuum heat insulating material 100A-I shown to FIG. 5A. It is a top view which shows the vacuum heat insulating material 100A-II manufactured in an example of the manufacturing method shown in FIG. It is sectional drawing in CC line of the vacuum heat insulating material 100A-II shown to FIG. 6A. FIG. 2 is an enlarged plan view of a post-housing welded part and a protective welded part of vacuum heat insulating material 100A-II manufactured in the example of the manufacturing method shown in FIG. It is a flowchart which shows an example of the manufacturing method of this invention. It is a flowchart which shows another example of the manufacturing method of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention is not limited to this. In the following description, an abbreviation such as “substantially the same size” means a range that can be seen by visual observation. In the vacuum heat insulating material, “inside” and “outside” refer to the side from the outer periphery toward the center and the side from the center toward the outer periphery, respectively, when the vacuum heat insulating material is viewed in the surface direction.

[Method of manufacturing vacuum insulation]
The method for manufacturing a vacuum heat insulating material according to the present invention is a method for manufacturing a vacuum heat insulating material having the following configuration (I), preferably (II), in which a core material is sealed in a sheath material under reduced pressure.
(I) The vacuum heat insulating material according to the production method of the present invention includes a jacket material in which a film having a heat-welded layer and an airtight layer is arranged so that the heat-welded layers face each other, and the inside of the jacket material A vacuum heat insulating material having a core material housed in the outer periphery of the core material, the outer cover material having a predetermined width over the entire periphery of the core material, and a heat-welded portion of the heat-welded layers on the outside of the weld portion While having the formed protective welding part, the inside is in a reduced pressure state.

  The vacuum heat insulating material of the structure of (II) which is a preferable structure in the vacuum heat insulating material which concerns on the manufacturing method of this invention arrange | positions the film which has a heat welding layer and an airtight layer so that the said heat welding layers may oppose. An outer cover material and a core material housed inside the outer cover material, the outer cover material being located outside the outer periphery of the core material, and the heat-welded layers covering the entire periphery of the core material Has a welded portion that is thermally welded and a protective welded portion formed on the outside of the welded portion so as to partially overlap at least a part of the welded portion, and the inside is in a reduced pressure state.

  The production method of the present invention is a method for producing such a vacuum heat insulating material having the structure (I), preferably (II), and the structure (I) has the following (1), (2), ( 3) and (4I). The configuration (II) includes the steps (1), (2), (3), and (4II) in which the step (4I) in the configuration (I) is specialized for the following step (4II). .

(1) A step of storing the core material in the outer cover material having an unwelded portion in which the portion to be the welded portion is not welded in the welded portion (hereinafter referred to as step (1) or “accommodating step”) Called.)
(2) About the jacket material containing the core material, the heat-welded layers of the unwelded portions are heat-welded in advance leaving a part necessary for decompression, or without heat-welding, It is a step of heat-welding the heat-welded layers under reduced pressure so that all of the welded parts are in a welded state, and for any of the heat-welding, a predetermined distance from the outer edge of the jacket material in which the core material is stored The process performed leaving the edge part of the width | variety (it is hereafter called process (2) or a "welding process after accommodation").
(3) a step of cleaning the surface of the facing heat-welding layer at the end portion of the outer covering material left outside the post-storage welded portion that has been heat-welded after the core material has been stored (hereinafter referred to as step (3) ) Or “cleaning process”.)
(4I) A step of forming the protective welded portion so as to have a region where the cleaned heat-welded layers are thermally welded to the outside of the post-storage welded portion (hereinafter referred to as step (4I) or “protective welded”). Step I ”)
(4II) A step of forming the protective welded portion so as to have a predetermined overlapping width from the outer side of the post-storage welded portion to the inside and to have a region where the cleaned heat-welded layers are thermally welded to each other; (Hereinafter referred to as step (4II) or “protective welding step II”)

  In the step (4I), the protective weld portion may be formed outside the post-storage weld portion, and the protective weld portion as shown in (4II) is formed so as to overlap with the post-storage weld portion. Embodiments are also included. Further, the step (4I) and the step (4II) may be collectively referred to as a step (4). The protective welding process I and the protective welding process II described below may be collectively referred to as a protective welding process.

Hereinafter, each process in the manufacturing method of this invention is demonstrated.
1 and 2 are diagrams schematically showing examples of the production method of the present invention. In the production method of the present invention, the above step (2) is the part necessary for decompression of the heat-welded layers in the unwelded portion (2a) with respect to the jacket material after storing the core material obtained in step (1). (2b) Non-welding of the jacket material after passing through the step (hereinafter also referred to as the step (2a) or “normal pressure welding step”) or without performing the step (2a). This is a step (hereinafter also referred to as “step (2b)” or “vacuum welding step”) in which the heat-welded layers are thermally welded under reduced pressure so that all of the parts are welded. That is, in the step (2), the step (2a) is an arbitrary step. FIG. 1 shows an example in which the step (2) is composed only of the step (2b), and FIG. 2 shows an example in which the step (2) is composed of the step (2a) and the step (2b). Show.

  1 and 2, reference numerals (1), (2a), (2b), (3), (4I), and (4II) denote the steps (1), (2a), and ( This corresponds to 2b), step (3), step (4I), and step (4II). In FIG. 1 and FIG. 2, step (4I) is shown as a case where the protective welding portion is formed outside the post-storage weld portion so as not to overlap with the post-storage weld portion. Step (4II) is a case where the protective welding portion is formed so as to have an overlapping portion with the post-storage weld portion outside the post-storage weld portion as described above.

  Further, in FIG. 1, 100A-I obtained through the steps (1), (2b), (3), (4I) corresponds to the vacuum heat insulating material having the configuration (I), and the steps (1), 100A-II obtained through (2b), (3), and (4II) corresponds to the vacuum heat insulating material having the configuration of (II), which is a preferred embodiment among the configurations of (I). Further, in FIG. 2, 100B-I obtained through the steps (1), (2a), (2b), (3), (4I) corresponds to the vacuum heat insulating material having the configuration (I), and the step ( 100B-II obtained through 1), (2a), (2b), (3), and (4II) is a vacuum heat insulation having the configuration of (II), which is a preferred embodiment among the configurations of (I). Corresponds to the material.

  First, the manufacturing method of the vacuum heat insulating material 100A-I of this invention in case the process (2) shown in FIG. 1 is comprised only by a process (2b) is demonstrated. 3A, FIG. 4A, and FIG. 5A are each an example of the manufacturing method shown in FIG. 1, and is also referred to as an outer sheath material (hereinafter referred to as “core material accommodating outer sheath material”) in which the core material after step (1) is accommodated. .), A jacket material (hereinafter, also referred to as “vacuum heat insulating material precursor”) in which the core material after the completion of the step (2) is accommodated and vacuum-welded, and the vacuum heat insulation obtained after the completion of the step (4I). The top view of material 100A-I is shown. 3B, FIG. 4B, and FIG. 5B are cross-sectional views of members that are shown in plan views in FIG. 3A, FIG. 4A, and FIG. 5A, respectively.

  The vacuum heat insulating material having the configuration (I) and obtained by the manufacturing method schematically shown in FIG. 1 is a vacuum heat insulating material 100A-I shown in FIGS. 5A and 5B. The vacuum heat insulating material 100 </ b> A-I is housed in an outer covering material 3 in which a film having a heat welding layer 1 and an airtight layer 2 is arranged so that the heat welding layers 1 face each other, and the outer covering material 3. It has a core material 4. The jacket material 3 has welding portions X1 and X2 that are located on the outer side of the outer periphery of the core material 4 and in which the heat-welded layers 1 are thermally welded with a predetermined width over the entire periphery of the core material 4.

  In addition, in vacuum heat insulating material 100A-I, the welding part X1 is a welding part (welding part before accommodation) formed before accommodating the core material 4 in the jacket material 3, and the welding part X2 is the core material 4. It is the welding part (after-storage welding part) formed after accommodating in the jacket material 3. FIG. The welded portion X1 and the welded portion X2 form a continuous frame-like welded portion so as to surround the entire periphery of the core material 4, and the inside of the jacket material 3 that stores the core material 4 can be in a reduced pressure state. It is said. Hereinafter, the entire frame-like welded portion including the welded portion X1 and the welded portion X2 is also referred to as a welded portion X.

  In the vacuum heat insulating materials 100A-I shown in FIGS. 5A and 5B, the jacket material 3 is a film having a rectangular main surface, and the core material 4 is a flat plate having a rectangular main surface. The inner periphery and the outer periphery are each formed in a rectangular frame shape. In the welded part X, the three sides of the frame are the welded part X1, and the remaining one side is the welded part X2. In vacuum heat insulating material 100A-I, about the welding part X2, it has the protective welding part Y formed in the outer side of the welding part X2. The protective welded portion Y forms a region welded in a continuous frame shape so as to surround the entire periphery of the core material 4 together with the welded portion X1. By setting it as such a structure, it becomes possible to interrupt | block the welding part X2 formed after accommodating the core material 4 in the jacket material 3 from external atmosphere. As a result, the obtained vacuum heat insulating material 100A-I becomes a vacuum heat insulating material in which a decrease in the degree of vacuum is suppressed.

  In the manufacturing method of the present invention, it is indispensable to provide a protective weld portion Y formed outside the weld portion X2 for the weld portion X2 formed after the core material 4 is accommodated in the jacket material 3. It is. Moreover, you may provide the protective welding part Y with respect to the welding part X1. In that case, the structure which forms the area | region welded in the shape of a frame without a cut | interruption so that only the protective welding part may surround the circumference | surroundings of a core material may be sufficient. The welded portion X1 is a welded portion formed before the core material 4 is accommodated in the jacket material 3, and dust is not sandwiched between the welded portions. Therefore, the protective welded portion Y is not necessarily required for the welded portion X1. However, since an extra process is added to the manufacturing process, the cost is increased, but there is an advantage that the airtightness becomes higher.

  Here, in the vacuum heat insulating material 100A-I, as another configuration of the frame-shaped welded portion X, two sides of the frame are the welded portions X1, and the remaining two sides are the welded portions X2. A configuration in which the side is the welded portion X1 and the remaining three sides are the welded portion X2 or a configuration in which all the sides are the welded portion X2 may be employed. In any case, the protective weld Y is provided outside the weld X2 for the weld X in the weld X. In any case, the protective welding portion Y forms a continuous frame-like region so as to surround the entire periphery of the core material 4 together with the welding portion X1 or only the protective welding portion Y. Thus, by providing the welded part X2 to the welded part X2 formed after the cored material 4 is accommodated in the jacket material 3 by the method of the present invention, the welded part X2 becomes the cored material 4. Even when dust caused by the above is sandwiched, it is possible to manufacture a vacuum heat insulating material in which a decrease in the degree of vacuum is suppressed in long-term use.

  Note that, in the vacuum heat insulating material 100A-I, the welded portion X2 and the protective welded portion Y are welded portions obtained in different steps in manufacturing, and are distinguished, but in the obtained vacuum heat insulating material 100A-I, Cannot be identified. In the present specification, a welded part consisting only of the welded part X1, a welded part formed by the welded part X2 and the protective welded part Y (including an unwelded part between the welded part X2 and the protective welded part Y), and The welded portion where the welded portion X2 and the protective welded portion Y are combined is referred to as a “seal portion”.

(Process (1))
In FIG. 1, in (1), the core material 4 is inserted into the jacket material 3 in which the welded portion X is partially unwelded, and the core material 4 is stored in the jacket material 3 (1). ). 3A and 3B show the core material housing material 10a after completion of the step (1). In the manufacturing method of the present invention, a portion where the welded portion X when it finally becomes a vacuum heat insulating material is not welded in the manufacturing process is referred to as an unwelded portion M. In the step (1), the jacket material 3 having the unwelded portion M is used.

  1 (A), FIG. 3 (A), and FIG. 3 (B), the outer cover material 3 has a rectangular two-layer film formed by laminating the heat-welding layer 1 and the air-tight layer 2, and each film has a heat-welding layer having the same size. 1 is a bag-shaped outer covering material in which three sides are overlapped with each other facing each other and three sides are heat-welded in advance with a predetermined width (w1). That is, three of the frame-like welded portions X that are finally composed of four sides are already formed as welded portions X1, and the remaining one side is an unwelded portion M, so that the jacket material 3 is not welded. It has a bag shape having an opening 5 corresponding to the part M.

  The width (w1) of the welded portion X1 is not particularly limited as long as it does not cause a decrease in the degree of vacuum during long-term use as a vacuum heat insulating material. The width (w1) of the welded portion X1 is specifically preferably 5 to 20 mm, and more preferably 5 to 10 mm, although it depends on the constituent material of the heat-welded layer 1 and the size of the jacket material 3. In addition, the distance between the outer side of the welded part X1 that is the outer periphery of the welded part X and the outer periphery of the jacket material 3 is not particularly limited as long as it does not cause a decrease in the degree of vacuum during long-term use as a vacuum heat insulating material. Depending on the constituent material of the heat-welding layer 1 and the size of the outer covering material 3, specifically, about 0 to 15 mm is preferable, and about 1 to 10 mm is more preferable.

  In the step (1), the jacket material 3 formed in a bag shape in this way is prepared, and the core material 4 formed in a flat plate shape is inserted into the inside from the opening 5. The main surface of the core material 4 shown in FIG. 1 is a size that can be stored inside the welded portion X, and the thickness is a thickness that can be stored inside the jacket material 3. In this way, the core material housing material 10a is obtained. 3A and 3B show a plan view and a cross-sectional view of the core material housing material 10a. In addition, in the cross section of the core material housing material 10a, the interface between the opposing heat welding layers 1 of the jacket material 3 is not clearly present by welding in the welding portion X1, but in FIG. The interface between the heat welding layers 1 is indicated by a broken line as the interface before the heat welding. Hereinafter, in the sectional views, the description of the cross section of the welded portion is the same as described above.

  Examples of the material constituting the covering material 3 and the core material 4 used in the manufacturing method of the present invention include the following known materials. In addition, the method of process (1) is a conventionally well-known method. In the step (1), when the core material 4 includes a factor that generates dust regardless of the types of the jacket material 3 and the core material 4, when the core material 4 is loaded on the jacket material 3, Dust is generated when the core material 4 comes into contact with the outer jacket material 3 at the opening 5 of the workpiece 3, and for example, the dust 6 adheres to the surface of the heat welding layer 1 near the opening 5 as shown in FIG. 3B. I think that. In the conventional method, when the opening is finally thermally welded, a welded portion is formed in which the dust is sandwiched, and the degree of vacuum may decrease due to the welded portion that sandwiches the dust. It was. In the manufacturing method of the present invention, steps (2) to (4) are provided after step (1) to form a protective welded portion that hardly holds dust, thereby suppressing a decrease in vacuum caused by dust. Is.

  In the present specification, “dust” is a microscopic object including a part of the material constituting the core material generated from the core material, and induces leakage of the welded portion by sandwiching it. It refers to all microscopic objects that are expected to have an adverse effect on the degree of vacuum of a vacuum heat insulating material.

  Such an effect of the manufacturing method of the present invention is particularly remarkable because dust is easily generated and adhered when a core material containing powder is used as the core material. As a core material used for the manufacturing method of the vacuum heat insulating material of this invention, the compression molding body containing a powder and a fiber body is preferable.

<Coating material>
In the manufacturing method of the present invention, the outer cover material may be an outer cover material having a structure in which a heat-welded layer and an airtight layer are laminated in a film shape, and is usually an outer cover material used as an outer cover material of a vacuum heat insulating material. The material can be used without any particular limitation. The jacket material may have a surface protective layer in addition to the heat-welded layer and the airtight layer, and preferably has a surface protective layer. In this case, the jacket material has a structure having a heat-welded layer on the side where the core material is accommodated, an airtight layer as an intermediate layer, and a surface protective layer as an outermost layer.

  As a constituent member of the jacket material, for example, a laminate film having a metal layer made of a metal foil as an airtight layer or a metal vapor deposition layer on one surface of the surface protective layer can be used. Moreover, you may use combining two types of laminate films, the laminate film which has metal foil, and the laminate film which has a metal vapor deposition layer. A jacket material is formed by laminating a heat-welding layer on the metal layer side of these laminate films. Here, although the code | symbol 2 is demonstrated as an airtight layer in the above, the code | symbol 2 may be an airtight layer itself in each drawing, and the laminate film which has an airtight layer and a surface protective layer may be sufficient as it.

  Examples of the material constituting the heat-welded layer, the airtight layer, and the surface protective layer of the outer covering material include the same materials as those constituting the respective layers used for the outer covering material of the vacuum heat insulating material. Specifically, the constituent material of the heat welding layer is low density polyethylene, linear low density polyethylene, high density polyethylene, polypropylene, polyacrylonitrile, unstretched polyethylene terephthalate, ethylene-vinyl alcohol copolymer, ethylene-tetrafluoroethylene. A copolymer etc. are mentioned. As a heat welding layer, you may consist of the composite material which combined the film which consists of the material which comprises these heat welding layers, and this film.

  Specifically, a metal is mentioned as a constituent material of an airtight layer. As the surface protective layer, known materials such as nylon film, polyethylene terephthalate film, and stretched polypropylene film can be used.

<Core>
As a core material, the well-known core material used for a vacuum heat insulating material can be used. Specifically, a core material obtained by processing a porous body having a gas phase ratio of about 90% into a plate shape is used. Examples of the porous body that can be industrially used include foams, powders, and fiber bodies having air permeability. For the core material, a known heat insulating material (hereinafter also referred to as “heat insulating material”) can be appropriately selected and used depending on the intended use and required characteristics.

Among these, as the foam, open-cell bodies such as urethane foam, styrene foam, and phenol foam can be used. In view of facilitating evacuation at the time of vacuum encapsulation, the air flow rate of the open cell body used as the core material is preferably 1 cm ³ / cm ² sec or more. In addition, inorganic, organic, and mixtures thereof can be used as the powder, but industrially, powders mainly composed of dry silica, wet silica, pearlite, and the like can be used.

  In addition, inorganic, organic, and mixtures thereof can be used as the fibrous body, but inorganic fibers are advantageous from the viewpoint of cost and heat insulation performance. As an example of the inorganic fiber, a known material such as glass wool, glass fiber, alumina fiber, silica alumina fiber, silica fiber, rock wool, or the like can be used.

  Furthermore, mixtures and composites of these foams, powders, and fiber bodies can also be applied to the core material. Specific examples of such a core material include a composite of a porous powder and a fibrous body, for example, an airgel blanket. Examples of the airgel blanket include pyrogel (manufactured by Aspen).

  Of these, a core material in which a heat insulating material containing powder is compression-molded into a plate shape will be described below. As the heat insulating material of the core material including powder, it is preferable that fibers are included in addition to the powder from the viewpoint of easily obtaining a high-strength core material. In addition to the fibers, a binder may be included, but in order to obtain better heat insulating performance, the binder ratio is preferably small and may not be included.

<< Powder >>
The case of a core material containing powder will be described below as an example.
As powder, the well-known powder normally used for a core material can be used. Specific examples include fumed silica, porous silica, and a radiation suppressing material. The powder preferably contains fumed silica from the viewpoint of easily obtaining a core material having sufficient strength.
Only one type of powder may be used, or two or more types may be used in combination.

Specific examples of fumed silica include, for example, Aerosil 200 (specific surface area 200 m ² / g, manufactured by Nippon Aerosil Co., Ltd.), Aerosil 300 (specific surface area 300 m ² / g, manufactured by Nippon Aerosil Co., Ltd.), CAB-O-SIL M- 5 (specific surface area 200 m ² / g, manufactured by Cabot Specialty Chemicals Inc.), CAB-O-SIL H-300 (specific surface area 300 m ² / g, manufactured by Cabot Specialty Chemicals Inc.), Leoroseal QS30 ( And a specific surface area of 300 m ² / g, manufactured by Tokuyama Corporation).
Fumed silica may use only 1 type and may use 2 or more types together.

  Specific examples of the porous silica include M.I. S. Examples include GEL and sunsphere (both manufactured by AGC S-Tech).

  Examples of the radiation suppressing material include metal particles (aluminum particles, silver particles, gold particles, etc.), inorganic particles (graphite, carbon black, silicon carbide, titanium oxide, tin oxide, iron oxide, potassium titanate, etc.). It is done.

  The binder is preferably used as a binder solution by dissolving an inorganic binder such as sodium silicate, aluminum phosphate, magnesium sulfate, or magnesium chloride in a solvent, and more preferably an aqueous solution.

≪Fiber≫
When fibers are included in the heat insulating material, a high-strength core material is easily obtained.
As a fiber, the fiber normally used for a vacuum heat insulating material can be used, For example, a resin fiber and an inorganic fiber are mentioned. Of these, inorganic fibers are preferred because they have less outgas in a vacuum, can easily suppress a decrease in heat insulation performance due to a decrease in the degree of vacuum, and are excellent in heat resistance.

  Examples of the inorganic fiber include alumina fiber, mullite fiber, silica fiber, glass wool, glass fiber, rock wool, slag wool, silicon carbide fiber, carbon fiber, silica alumina fiber, silica alumina magnesia fiber, silica alumina zirconia fiber, silica magnesia. Examples include calcia fiber.

≪Powder, binder, fiber ratio≫
The ratio of fumed silica in the powder (100% by mass) is preferably 50 to 100% by mass, more preferably 70 to 100% by mass, and particularly preferably 80 to 100% by mass. If the ratio of fumed silica is not less than the lower limit of the above range, a core material with high strength can be easily obtained.

  When the powder contains a radiation suppressing material, the proportion of the radiation suppressing material in the powder (100% by mass) is preferably 3 to 30% by mass, more preferably 5 to 25% by mass, and particularly 10 to 20% by mass. preferable.

  The ratio of the fiber is preferably 1 to 30 parts by mass, more preferably 2 to 20 parts by mass, and particularly preferably 4 to 10 parts by mass with respect to 100 parts by mass of the powder. When the fiber ratio is equal to or higher than the lower limit of the above range, a high-strength core material is easily obtained. If the ratio of the fiber is equal to or less than the upper limit of the above range, an increase in solid heat transfer due to the fiber can be suppressed, so that it is easy to suppress a decrease in heat insulation performance.

  When powder is used as the core material, the preferred composition of the powder is mass ratio, and 70 to 90: 0 to 20:10 to 20 is preferred as fumed silica: porous silica: radiation suppression material. Moreover, 70-90: 0-20: 5-10: 5-20 are preferable as a preferable composition when a powder contains a fiber as a fumed silica: porous silica: fiber: radiation suppression material by mass ratio.

(Process (2))
As described above, in the method for manufacturing the vacuum heat insulating material 100A-I shown in FIG. 1, the step (2) is the unwelded portion of the core material housing material 10a that is the skin material 3 housing the core material 4. It consists only of the process (2b) of heat-welding the heat welding layers 1 under reduced pressure so that all of M is welded, that is, the vacuum welding process. About the vacuum heat insulating material precursor obtained after completion | finish of a process (2), in FIG. 1, the code | symbol of 10b is attached | subjected and shown as the state returned to atmospheric pressure conditions after the said heat welding under pressure reduction. 4A and 4B are a plan view and a cross-sectional view of the vacuum heat insulating material precursor 10b. In addition, the process (2a) which is an arbitrary process in the process (2), that is, the atmospheric pressure welding process will be described in the manufacturing method of the vacuum heat insulating material 100B shown in FIG.

  In FIG. 1, in (2b), the core material housing material 10a prepared in (1) is placed under reduced pressure, and heat is applied so that the entire unwelded portion M of the skin material 3 is welded. Perform welding. Specifically, the portion of the frame-like welded portion X that is finally composed of four sides so that the remaining one side except the three sides already formed as the welded portion X1 is welded. The heat welding layers 1 facing each other are thermally welded to obtain a vacuum heat insulating material precursor 10b. That is, the vacuum heat insulating material precursor 10b has a configuration in which all the frame-shaped welded portions X are welded and sealed under reduced pressure so that the core material 4 is positioned inside thereof. In addition, the welding part obtained by heat-welding at a process (2b) is the welding part (welding part after accommodation) X2 formed after accommodating the core material 4 in the jacket material 3. FIG.

  Moreover, you may substitute the bending part which bent one sheet | seat covering material 10a as 1 side of the welding part X1. In addition, in the step (2b), it is preferable to temporarily fix the outside of the unwelded portion M with a clip or the like because it is possible to prevent the covering material from being displaced when the vacuum is applied.

  The width (w2) of the welded portion X2 in the vacuum heat insulating material precursor 10b is a width that allows the inside of the jacket material to maintain a reduced pressure state by forming the welded portion X2, so as to assist the sealing function of the welded portion X2 later. If it is the width | variety which does not cause the fall of a vacuum degree in long-term use as a vacuum heat insulating material with the protective welding part Y formed in this, it will not restrict | limit in particular. It may be the same as or different from the width (w1) of the weld portion X1. Although it depends on the configuration of the protective welded portion Y, specifically, the width (w2) of the welded portion X2 is preferably 5 to 20 mm.

  Further, in the step (2b), the thermal welding for forming the welded portion X2 leaves the end portion 7 having a predetermined width (w3) inward from the outer edge of the jacket material 3 in which the core material 4 is accommodated. Done. The width (w3) of the end portion 7 is the distance between the outer side of the welded portion X2 that is the outer periphery of the welded portion X and the outer edge of the jacket material 3, and the step (3) that is performed next ( In 4), the width is not particularly limited as long as the protective welding portion Y can be formed. The width (w4) of the protective welding portion Y described later and the width (w8) of the unwelded portion between the welding portion X2 and the protective welding portion Y in the vacuum heat insulating material 100A-I, and the welding in the vacuum heat insulating material 100A-II. It adjusts suitably according to the overlap width (w5) etc. of the part X2 and the protective welding part Y. The width (w3) of the end portion 7 is preferably adjusted so that the distance from the outer side of the protective welding portion Y to the outer edge of the outer jacket material 3 is about 0 to 15 mm.

  As an apparatus for executing the step (2b), a normally used apparatus can be used without particular limitation in a vacuum heat insulating material manufactured by inserting a plate-shaped core material into a bag-shaped outer cover material. For example, a vacuum chamber with a heat seal function may be used. In addition, the same conditions as in the case of producing the vacuum heat insulating material as described above using such an apparatus can be applied to the decompression conditions and the heat welding conditions during the production.

In addition, in the vacuum heat insulating material 100A-I, the degree of vacuum inside the jacket material 3 inside the welded portion X of the jacket material 3 provides excellent heat insulating performance, and the life of the vacuum heat insulating material is prolonged. 1 × 10 ³ Pa or less is preferable, and 1 × 10 ² Pa or less is more preferable.

The manufacturing conditions in the reduced pressure welding step are preferably set to conditions that allow the vacuum degree to be achieved. Moreover, the material which comprises the heat welding layer which the jacket material 3 has is as above, In the case of the said heat welding, suitable welding temperature is set according to this material. Furthermore, heat welding is usually performed under a pressurized condition of about 1 to 5 kg / cm ² .

  Here, in the vacuum heat insulating material precursor 10b obtained through the steps (1) and (2b) shown in FIG. 1, the welded portion X2, which is a post-storage welded portion after the core material is stored, is In the step (1), the dust 6 that is mainly generated from the core material 4 and adheres to the surface of the heat welding layer 1 near the opening 5 is sandwiched as it is. In the conventional manufacturing method, since the vacuum heat insulating material precursor 10b in such a state is used as a finished product of the vacuum heat insulating material as it is, the rate at which the degree of vacuum decreases with time due to leakage from the welded portion X2 increases. There is a risk. In the present invention, by the following step (3), step (4I), preferably step (4II), on the outer side, preferably on the outer side of the welded portion X2, so as to supplement the sealing property of the welded portion X2. The protective welding part Y is formed so as to cover the surface, and the risk of increasing the rate of decrease in the degree of vacuum in long-term use is suppressed.

  In addition, in order to reduce the amount of dust sandwiched by the welded portion X2, the welded portion which is the welded portion after storing after the core material 4 is stored in the outer cover material 3 between the steps (1) and (2). Before forming X2, the dust 6 adhering to the surface of the heat-welded layer 1 of the unwelded portion that becomes the welded portion X2 may be removed, for example, a step similar to the following cleaning step may be provided. However, the dust 6 is moved by the decompression operation in the step (2b), and as a result, a considerable amount of the dust 6 is sandwiched between the welded portions X2, so that the effect of reducing the amount of dust sandwiched between the welded portions X2 is small and efficient. It may be disadvantageous in terms.

(Process (3))
In the step (3), for the vacuum heat insulating material precursor 10b obtained in the step (2), the outer covering material 3 left outside the welded portion X2 which is the welded portion after welding that is thermally welded after the core material is accommodated. This is a step of cleaning the surface of the thermal welding layer 1 facing at the end 7. FIG. 1 (3) and FIG. 4B are diagrams schematically showing the cleaning process.

  As described above, in the vacuum heat insulating material precursor 10b obtained in the step (2), the outer jacket material 3 has the end 7 having the width (w3) outside the welded portion X2. As shown in FIG. 1 (3) and FIG. 4B, at the end 7 of the jacket material 3, the two films having the heat-welding layer 1 and the airtight layer 2 are arranged so that the heat-welding layers 1 face each other. This is a state in which heat welding has not been performed. Moreover, as shown in FIG. 4B, at the end portion 7 after the step (2), the dust mainly generated from the core material 4 in the step (1) and adhering to the surface of the heat welding layer 1 facing each other. 6 remains.

  In the step (3), the dust 6 remaining on the surface is removed by cleaning the surface of the heat-welding layer 1 at the end 7. As a method for cleaning the surface of the heat-welded layer 1, that is, a method for removing dust 6 remaining on the surface of the heat-welded layer 1, there are various methods usually used for removing dust such as powder adhering to a resin film or the like. The method is applicable.

  Specific cleaning methods include wiping dust with paper and cloth, attaching dust to adhesive materials such as adhesive tape, blowing dust by blowing air, and sucking dust with a vacuum cleaner. It is done. Among these, from the viewpoint of removing dust without scratching the heat-welded layer, wiping off dust using paper or cloth is preferable. The paper or cloth used is preferably one that does not generate dust itself. Specifically, a method of wiping with wet paper or cloth such as wet tissue is particularly preferable because dust can be removed easily and effectively. As the paper or cloth, a nonwoven fabric in which synthetic fibers such as rayon and polyester are formed into a sheet shape is preferable.

  In the cleaning step, when a method of wiping with wet paper or cloth is used, it is preferable to sufficiently dry the surface of the heat-welded layer 1 before the step (4).

(Process (4I))
Step (4I) is a step of forming protective weld Y that is performed subsequent to step (3). In FIG. 1, the vacuum heat insulating material 100A-I obtained after the step (4I) in the case of taking the step (4I) as (4) is shown in the lower right together with the vacuum heat insulating material 100A-II. 5A and 5B are a plan view and a cross-sectional view of the vacuum heat insulating material 100A-I.

  In the step (4I), the protective welding portion Y is formed by thermally welding the heat-welded layers 1 cleaned in the step (3) to the outside of the welded portion X2, which is a post-storage welded portion that is thermally welded after the core material is stored. It is formed with a width (w4) so as to have a region formed. The protective welded portion Y forms a region welded over the entire periphery of the core together with the welded portion X1 which is the welded portion before storage.

  The protective weld Y is parallel to the weld X2 on the outside of the weld X2, and the width (w4) is such that the outer side of the weld X2 and the inner side of the protective weld Y have a predetermined distance (w8). ). Since the region outside the outer side of the welded portion X2 is cleaned in the step (3), the region where the heat-welded layers 1 in the protective welded portion Y are thermally welded is in the cleaned region.

  The width (w4) of the protective welded portion Y is preferably 3 to 15 mm, and more preferably 5 to 10 mm from the viewpoint of maintaining a high sealing effect.

  As described above, the seal portion S is configured by combining the weld portion X2 and the protective weld portion Y (including the unwelded portion between the weld portion X2 and the protective weld portion Y) formed outside the weld portion X2. Is done. The width (w9) of the seal portion S is indicated by w2 + w4 + w8. w8 is the width of the unwelded portion between the welded portion X2 and the protective welded portion Y. w8 is preferably 0 to 5 mm. The distance from the outer side of the seal portion, that is, the outer side of the protective welding portion Y, to the outer periphery of the jacket material is preferably 0 to 15 mm, and more preferably 1 to 10 mm.

In addition, about the conditions of the heat welding at the time of forming the protective welding part Y, the conditions similar to the case where the heat welding layers which the above-mentioned jacket materials have are heat-welded normally are applicable. Moreover, the material which comprises the heat welding layer which a jacket material has is as above, and in the case of the said heat welding, suitable welding temperature is set according to this material. Furthermore, heat welding is usually performed under a pressurized condition of about 1 to 5 kg / cm ² . Here, in this specification, unless otherwise specified, thermal welding other than thermal welding performed under reduced pressure is performed in an environment of normal pressure.

  In the vacuum heat insulating material 100A-I thus obtained, the amount of dust 6 sandwiched between the weld layers X2 in the seal portion S composed of the protective weld portion Y and the weld portion X2 has a corresponding amount. On the other hand, since the protective welding portion Y is formed by thermally welding the heat welding layers 1 in the region cleaned in the step (3), the amount of dust sandwiched between the protective welding portions Y is very small. Further, the amount of dust to be sandwiched is small even in the unwelded portion between the welded portion X2 having the predetermined width (w8) and the protective welded portion Y.

  Further, in the vacuum heat insulating material 100A-I, among the seal portion formed in a frame shape including the weld portion X1 formed before the core material is stored, the weld portion X2 formed after the core material is stored, and the protective weld portion Y. In the welded part X1, it can be said that there is almost no dust to be sandwiched. In the production method of the present invention, a vacuum in which a decrease in the degree of vacuum is suppressed in a long-term use by adding simple steps (3) and (4I) to the conventional method for producing a vacuum heat insulating material in this way. Insulation can be manufactured easily and economically. The production method of the present invention can be preferably used particularly when the porous body serving as a core material contains powder that is a factor that generates dust.

  Next, the manufacturing method of the vacuum heat insulating material 100B-I of this invention in case the process (2) shown in FIG. 2 is comprised by the process (2a) and the process (2b) is demonstrated.

  In the vacuum heat insulating material 100B-I, the welded portion X1 is a welded portion (a welded portion before storage) formed before the core material 4 is housed in the jacket material 3, and the welded portion X2 covers the core material 4 as the jacket. It is the welding part (after-storage welding part) formed after accommodating in the material 3. FIG. In the manufacturing method shown in FIG. 2, the welded part X2 is formed by the step (2a) and the step (2b). The welded portion X1 and the welded portion X2 form a continuous frame-like welded portion so as to surround the entire periphery of the core material 4, and the inside of the jacket material 3 that stores the core material 4 can be in a reduced pressure state. It is said.

  In the manufacturing method shown in FIG. 2, the jacket material 3 having an unwelded portion prepared in step (1) includes the jacket material 3 having an unwelded portion shown in the manufacturing method shown in FIG. All are the same except that is different.

  Specifically, the outer cover material 3 shown in (1) of FIG. 2 is a heat welding layer in which each film has a rectangular two-layer film in which a heat welding layer 1 and an airtight layer 2 are laminated. 1 is a structure in which 1 is opposed to each other and two adjacent sides are heat-welded in advance with a predetermined width (w1). That is, the two adjacent sides of the frame-shaped welded portion X finally composed of four sides are already formed as welded portions X1, and the remaining two adjacent sides are unwelded portions M, so that the jacket material Reference numeral 3 denotes a shape having an opening 5 corresponding to the unwelded portion M.

  In the step (1), the jacket material 3 molded in this way is prepared, and the core material 4 molded into a flat plate shape is inserted into the inside from the opening 5. The main surface of the core material 4 shown in FIG. 2 has such a size that the outer periphery is located inside the inner periphery of the welded portion X, and the thickness is a thickness that can be accommodated inside the jacket material 3.

  Even when the shape of the opening 5 of the jacket material 3 is made larger than that shown in FIG. 1 as shown in FIG. 2 in the step (1), the core material 4 is loaded into the jacket material 3. In particular, the dust is generated when the core material 4 comes into contact with the jacket material 3 at the opening 5 of the jacket material 3, and the dust 6 adheres to the surface of the heat-welded layer 1 near the opening 5. There is no. Therefore, the manufacturing method of the present invention which performs the welding process after storing in step (2) and then performs the cleaning process in step (3) and the protective welding process in step (4I) reduces the degree of vacuum even in long-term use. It is effective in obtaining a suppressed vacuum heat insulating material.

  In the manufacturing method shown in FIG. 2, one side of the unwelded portion is thermally welded in the step (2a) prior to the vacuum welding in the step (2b) for the core material housing material obtained in the step (1). Then, the remaining one side of the jacket material on which the three sides are heat-welded is vacuum-welded in the step (2b). The welded part X2 obtained by heat welding in the step (2a) is a welded part (post-contained welded part) formed after the core material 4 is housed in the jacket material 3. In addition, the specific method of the heat welding by a process (2a) can be performed similarly to the method of the heat welding at the time of forming the protective welding part Y demonstrated above.

  About the width | variety and formation position of the welding part X2 obtained by heat welding by a process (2a), in the manufacturing method shown in FIG. 1, it is the same as the width | variety and formation position at the time of forming the welding part X2 in a process (2b). it can. That is, the width of the welded portion X2 is preferably 5 to 20 mm, and the welded portion X2 is formed while leaving the end portion 7 having a predetermined width (w3) from the outer edge of the jacket material 3 toward the inside.

  In the manufacturing method shown in FIG. 2, next, step (2b) which is a welding step under reduced pressure similar to step 2 (b) shown in FIG. 1 is performed. In this way, the vacuum heat insulating material precursor 10b obtained through the steps (1), (2a), and (2b) shown in FIG. 2 is a post-storage welded portion that is thermally welded after the core material is stored. The welded part X2 on two sides is formed in a state in which dust 6 mainly generated from the core material 4 in the step (1) and attached to the surface of the heat welded layer 1 near the opening 5 is sandwiched as it is. In addition, dust 6 remains on the surface of the thermal welding layer 1 that is opposed to the end portion 7 of the covering material 3 that is left outside the welding portion X2 on the two sides.

  Therefore, in the step (3), the end portion 7 of the outer covering material 3 left outside the welded portion X2 on the two sides is cleaned in the same manner as described above, and further in the same manner as described above in the step (4I). For both of the welded parts X2 on the side, the protective welded part Y is placed outside the welded part X2, and the outer side of the welded part X2 and the inner side of the protective welded part Y have a predetermined distance (w8). The heat-welded layers 1 cleaned in the step (3) are formed with a width (w4) so as to have a heat-welded region. The protective welded portion Y forms a continuous welded region in a frame shape so as to surround the entire periphery of the core material 4 together with the welded portion X1 or only by the protective welded portion Y.

  As described above, in the manufacturing method of the present invention, even when the method shown in FIG. 2 is adopted, by adding simple steps (3) and (4I) to the conventional vacuum heat insulating material manufacturing method, Similarly to the material 100A-I, it is possible to easily and economically manufacture the vacuum heat insulating material 100B-I in which the decrease in the degree of vacuum is suppressed in the long-term use.

  Next, the manufacturing method of the vacuum heat insulating material of the structure of (II) which is a preferable structure in the vacuum heat insulating material of the structure of (I) is demonstrated.

  The vacuum heat insulating material according to (II), which is a preferred configuration of the production method of the present invention, is a jacket material formed by arranging a film having a heat welding layer and an airtight layer so that the heat welding layers face each other, It is a vacuum heat insulating material having a core material housed inside a jacket material, and the jacket material is a welded portion in which the heat-welded layers are heat-welded with a predetermined width over the entire periphery of the core material and While having the protective welding part formed in the outer side of the said welding part so that it may partially overlap with at least one part of a welding part, the inside is a pressure reduction state.

The manufacturing method of the vacuum heat insulating material of the structure of (II) of this invention is a method of manufacturing the above-mentioned vacuum heat insulating material of the structure of (II), Comprising: The process of the following (1)-(4II) is provided.
(1) A step (hereinafter referred to as a step (1) or “housing step”) in which the core material is housed in the outer cover material having an unwelded portion where the welded portion of the welded portion is unwelded. .)
(2) About the jacket material containing the core material, the heat-welded layers of the unwelded portions are heat-welded in advance leaving a part necessary for decompression, or without heat-welding, It is a step of heat-welding the heat-welded layers under reduced pressure so that all of the welded parts are in a welded state, and for any of the heat-welding, a predetermined distance from the outer edge of the jacket material in which the core material is stored The process performed leaving the edge part of the width | variety (henceforth a process (2) or "welding process after accommodation").
(3) A step of cleaning the surface of the facing heat-welded layer at the end portion of the outer cover material remaining outside the post-storage welded portion that has been heat-welded after the core material has been stored (hereinafter, step (3) Or referred to as “cleaning process”.)
(4II) A step of forming the protective welded portion so as to have a predetermined overlapping width inward from the outer side of the post-storage welded portion and a region where the cleaned heat-welded layers are thermally welded ( Hereinafter, referred to as step (4II) or “protective welding step II”.)

  Hereinafter, each process in the manufacturing method of the vacuum heat insulating material of the structure of (II) of this invention is demonstrated. In addition, in description using the same figure as the manufacturing method of the vacuum heat insulating material which has the structure of (I), description is abbreviate | omitted when description overlaps. 1 and 2 are diagrams schematically showing examples of the production method of the present invention.

  In FIG. 1, steps (1), (2b), and (3) are the same as the manufacturing method of the vacuum heat insulating material 100A-I having the configuration of (I). The step (4II) in the vacuum heat insulating material having the structure (II) is shown in the lower right in FIG. 1 together with the step (4I) in the vacuum heat insulating material having the structure (I).

  FIG. 6A shows a plan view of the vacuum heat insulating material 100A-II obtained after completion of the step (4II). 6B is a cross-sectional view of the member showing a plan view in FIG. 6A.

  The vacuum heat insulating material having the configuration of (II) and obtained by the manufacturing method schematically shown in FIG. 1 is a vacuum heat insulating material 100A-II shown in FIGS. 6A and 6B. The vacuum heat insulating material 100 </ b> A-II is housed in an outer covering material 3 in which a film having a heat welding layer 1 and an airtight layer 2 is arranged so that the heat welding layers 1 face each other, and the outer covering material 3. It has a core material 4. The jacket material 3 has welding portions X1 and X2 that are located on the outer side of the outer periphery of the core material 4 and in which the heat-welded layers 1 are thermally welded with a predetermined width over the entire periphery of the core material 4.

  In addition, in vacuum heat insulating material 100A-II, the welding part X1 is a welding part (welding part before accommodation) formed before accommodating the core material 4 in the jacket material 3, and the welding part X2 attaches the core material 4 to it. It is the welding part (after-storage welding part) formed after accommodating in the jacket material 3. FIG. The welded portion X1 and the welded portion X2 form a continuous frame-like welded portion so as to surround the entire periphery of the core material 4, and the inside of the jacket material 3 that stores the core material 4 can be in a reduced pressure state. It is said. Hereinafter, the entire frame-like welded portion including the welded portion X1 and the welded portion X2 is also referred to as a welded portion X.

  In the vacuum heat insulating material 100A-II shown in FIGS. 6A and B, the jacket material 3 is a film having a rectangular main surface, the core member 4 is a flat plate having a rectangular main surface, and the welded portion X is The inner periphery and the outer periphery are each formed in a rectangular frame shape. In the welded part X, the three sides of the frame are the welded part X1, and the remaining one side is the welded part X2. In the vacuum heat insulating material 100A-II, the welded portion X2 is overlapped with the welded portion X2, specifically, a predetermined width is overlapped inward from the outer side of the welded portion X2. The protective welded portion Y is formed outside the welded portion X2.

  By forming the protective welded portion Y as described above, the protective welded portion Y forms a region that is welded in a continuous frame shape so as to surround the entire periphery of the core material 4 together with the welded portion X1. By setting it as such a structure, it becomes possible to interrupt | block the welding part X2 formed after accommodating the core material 4 in the jacket material 3 from external atmosphere. As a result, the obtained vacuum heat insulating material 100A-II is a vacuum heat insulating material in which a decrease in the degree of vacuum is suppressed.

  In the method for manufacturing a vacuum heat insulating material having the configuration (II), the outer side of the welded portion X2 is covered with respect to the welded portion X2 formed after the core material 4 is accommodated in the jacket material 3. Thus, it is essential to provide the protective welding portion Y formed so as to partially overlap the welding portion X2. Although the protective welding part Y may be provided with respect to the welding part X1, the welding part X1 is a welding part formed before accommodating the core material 4 in the jacket material 3, and dust is clamped by the welding part. Therefore, it is not always necessary, and an extra process is added to the manufacturing process, which causes an increase in cost.

  Here, in the vacuum heat insulating material 100A-II, as another configuration of the frame-shaped welded portion X, a configuration in which two sides of the frame are welded portions X1 and the remaining two sides are welded portions X2, A configuration in which the side is the welded portion X1 and the remaining three sides are the welded portion X2 or a configuration in which all the sides are the welded portion X2 may be employed. In any case, the welded portion X2 of the welded portion X is a protective welded portion so as to partially overlap the welded portion X2 so as to cover the outer side of the welded portion X2 outside the welded portion X2. Y is provided.

  By providing the welded portion X2 formed after the core material 4 is accommodated in the jacket material 3 by the method of the present invention, the protective welded portion Y is provided so as to have an overlapping portion of a predetermined width outside thereof. Even when the welded part X2 sandwiches dust caused by the core material 4 or the like, it is possible to manufacture a vacuum heat insulating material in which a decrease in the degree of vacuum is suppressed in long-term use. When the overlap portion is provided, the degree of vacuum is reduced in long-term use as compared with the case where there is no overlap between the weld portion X2 and the protective weld portion Y or there is an unwelded portion between the weld portion X2 and the protective weld portion Y. Is easily suppressed. It is considered that when the welded portion X2 deteriorates before the protective welded portion Y, the degree of vacuum decreases due to the air remaining in the unwelded portion.

(Process (1))
Step (1) is the same as the vacuum heat insulating material A100-I, including the preferred embodiment.

<Coating material>
In the manufacturing method of the vacuum heat insulating material A100-II, the jacket material is the same as that of the vacuum heat insulating material A100-I including the preferred embodiment.

<Core>
In the manufacturing method of the vacuum heat insulating material A100-II, the core material is the same as that of the vacuum heat insulating material A100-I including the preferred embodiment.

(Process (2))
In the manufacturing method of the vacuum heat insulating material A100-II, the step (2) is the same as the vacuum heat insulating material A100-I including the preferred embodiment.

(Process (3))
In the manufacturing method of the vacuum heat insulating material A100-II, the step (3) is the same as the vacuum heat insulating material A100-I including the preferred embodiment.

(Step (4II))
Step (4II) is a step of forming protective weld Y that is performed after step (3). In FIG. 1, the vacuum heat insulating material 100A-II obtained after the step (4II) in the case of taking the step (4II) as (4) is shown in the lower right together with the vacuum heat insulating material 100A-I. 6A and 6B are a plan view and a cross-sectional view of the vacuum heat insulating material 100A-II, and FIG. 7 is an enlarged plan view of the post-housing welded portion X2 and the protective welded portion Y of the vacuum heat insulating material 100A-II. The relationship between the formation part of the welding part X2 and the protection welding part Y is demonstrated by these. In addition, the dust 6 shown in FIG. 7 does not exist on the surface of the vacuum heat insulating material 100 </ b> A-II, but schematically shows what exists at the interface where the opposing heat-welding layers are heat-welded.

  In the step (4II), the protective welding portion Y has a predetermined overlap width (w5) on the inner side from the outer side of the welded portion X2, which is a post-storage welded portion that is thermally welded after the core material is stored, The heat-welded layers 1 cleaned in 3) are formed with a width (w4) so as to have a heat-welded region.

  The width of the protective welded portion Y is further increased so that the predetermined width (w5) overlaps the entire length of the outer side of the welded portion X2 and parallel to the welded portion X2 on the outer side of the welded portion X2. (W4) is formed larger than the overlap width (w5). A region outside the outer side of the welded portion X2 in the protective welded portion Y is a region where the heat-welded layers 1 cleaned in the step (3) are thermally welded. Here, the width (w4) of the protective welded portion Y is a value obtained by subtracting the overlap width (w5) from the width (w4), that is, a region where the heat-welded layers 1 cleaned in the step (3) are heat-welded. The width (w6) is set so as not to exceed the width (w3) of the end portion 7 of the jacket material 3. In other words, the outer side of the protective welding portion Y is formed so as to be located on the inner side of the outer periphery of the jacket material 3.

  The overlapping width (w5) of the protective weld Y and the weld X2 may be the same as the width (w2) of the weld X2. From the viewpoint of maintaining a high sealing effect, the overlap width (w5) is preferably 1 to 5 mm, and more preferably 2 to 4 mm. Similarly, from the viewpoint of maintaining a high sealing effect, the width (w4) of the protective welded portion Y is preferably 3 to 15 mm, and more preferably 5 to 10 mm. Furthermore, 2-10 mm is preferable and, as for the width | variety (w6) of the area | region where the heat welding layers 1 cleaned in the process (3) were heat-welded among the protective welding parts Y, 3-8 mm is more preferable.

  As described above, the seal portion S is configured by combining the weld portion X2 and the protective weld portion Y formed to overlap the weld portion X2 with a predetermined width. The width (w7) of the seal portion S is represented by w2 + w6, preferably 12 to 20 mm, and more preferably 15 to 18 mm. Moreover, 0-15 mm is preferable and, as for the distance from the outer side of a seal | sticker part, the outer periphery of a jacket material, 1-10 mm is more preferable.

In addition, about the conditions of the heat welding at the time of forming the protective welding part Y, the conditions similar to the case where the heat welding layers which the above-mentioned jacket materials have are heat-welded normally are applicable. Moreover, the material which comprises the heat welding layer which a jacket material has is as above, and in the case of the said heat welding, suitable welding temperature is set according to this material. Furthermore, heat welding is usually performed under a pressurized condition of about 1 to 5 kg / cm ² . Here, in this specification, unless otherwise specified, thermal welding other than thermal welding performed under reduced pressure is performed in an environment of normal pressure.

  In the vacuum heat insulating material 100A-II obtained in this way, as shown in FIG. 7, the amount of dust 6 sandwiched between the weld layers X2 in the seal portion S composed of the protective weld portion Y and the weld portion X2 is appropriate. In the region where the heat-welded layers 1 cleaned in the step (3) are thermally welded in the protective welded portion Y, the amount of dust is very small. Further, in the vacuum heat insulating material 100A-II, among the seal portion formed in a frame shape including the weld portion X1 formed before the core material is stored, the weld portion X2 formed after the core material is stored, and the protective weld portion Y. In the welded part X1, it can be said that there is almost no dust to be sandwiched. In the production method of the present invention, a vacuum in which a decrease in the degree of vacuum is suppressed in a long-term use by adding simple steps (3) and (4II) to the conventional method for producing a vacuum heat insulating material in this way. Insulation can be manufactured easily and economically. The production method of the present invention can be preferably used particularly when the porous body serving as a core material contains powder that is a factor that generates dust.

  Next, the manufacturing method of the vacuum heat insulating material 100B-II shown in FIG. 2 when the step (2) is composed of the step (2a) and the step (2b) will be described.

  In the vacuum heat insulating material 100B-II, the welded portion X1 is a welded portion (a welded portion before storage) formed before the core material 4 is housed in the jacket material 3, and the welded portion X2 covers the core material 4 as the jacket. It is the welding part (after-storage welding part) formed after accommodating in the material 3. FIG. In the manufacturing method shown in FIG. 2, the welded part X2 is formed by the step (2a) and the step (2b). The welded portion X1 and the welded portion X2 form a continuous frame-like welded portion so as to surround the entire periphery of the core material 4, and the inside of the jacket material 3 that stores the core material 4 can be in a reduced pressure state. It is said.

  In the manufacturing method shown in FIG. 2, the jacket material 3 having an unwelded portion prepared in step (1) includes the jacket material 3 having an unwelded portion shown in the manufacturing method shown in FIG. All are the same except that is different.

  Specifically, the outer cover material 3 shown in (1) of FIG. 2 is a heat welding layer in which each film has a rectangular two-layer film in which a heat welding layer 1 and an airtight layer 2 are laminated. 1 is a structure in which 1 is opposed to each other and two adjacent sides are heat-welded in advance with a predetermined width (w1). That is, the two adjacent sides of the frame-shaped welded portion X finally composed of four sides are already formed as welded portions X1, and the remaining two adjacent sides are unwelded portions M, so that the jacket material Reference numeral 3 denotes a shape having an opening 5 corresponding to the unwelded portion M.

  In the step (1), the jacket material 3 molded in this way is prepared, and the core material 4 molded into a flat plate shape is inserted into the inside from the opening 5. The main surface of the core material 4 shown in FIG. 2 has such a size that the outer periphery is located inside the inner periphery of the welded portion X, and the thickness is a thickness that can be accommodated inside the jacket material 3.

  Even when the shape of the opening 5 of the jacket material 3 is made larger than that shown in FIG. 1 as shown in FIG. 2 in the step (1), the core material 4 is loaded into the jacket material 3. In particular, the dust is generated when the core material 4 comes into contact with the jacket material 3 at the opening 5 of the jacket material 3, and the dust 6 adheres to the surface of the heat-welded layer 1 near the opening 5. There is no. Therefore, the preferred manufacturing method of the present invention in which the post-storage welding step in the step (2) is performed, and then the cleaning step in the step (3) and the protective welding step in the step (4II) is performed is reduced in the long-term use. This is effective in obtaining a vacuum heat insulating material in which is suppressed.

  In the manufacturing method shown in FIG. 2, one side of the unwelded portion is thermally welded in the step (2a) prior to the vacuum welding in the step (2b) for the core material housing material obtained in the step (1). Then, the remaining one side of the jacket material on which the three sides are heat-welded is vacuum-welded in the step (2b). The welded part X2 obtained by heat welding in the step (2a) is a welded part (post-contained welded part) formed after the core material 4 is housed in the jacket material 3. In addition, the specific method of the heat welding by a process (2a) can be performed similarly to the method of the heat welding at the time of forming the protective welding part Y demonstrated above.

  About the width | variety and formation position of the welding part X2 obtained by heat welding by a process (2a), in the manufacturing method shown in FIG. 1, it is the same as the width | variety and formation position at the time of forming the welding part X2 in a process (2b). it can. That is, the width of the welded portion X2 is preferably 5 to 20 mm, and the welded portion X2 is formed while leaving the end portion 7 having a predetermined width (w3) from the outer edge of the jacket material 3 toward the inside.

  In the manufacturing method shown in FIG. 2, next, step (2b) which is a welding step under reduced pressure similar to step 2 (b) shown in FIG. 1 is performed. In this way, the vacuum heat insulating material precursor 10b obtained through the steps (1), (2a), and (2b) shown in FIG. 2 is a post-storage welded portion that is thermally welded after the core material is stored. The welded part X2 on two sides is formed in a state in which dust 6 mainly generated from the core material 4 in the step (1) and attached to the surface of the heat welded layer 1 near the opening 5 is sandwiched as it is. In addition, dust 6 remains on the surface of the thermal welding layer 1 that is opposed to the end portion 7 of the covering material 3 that is left outside the welding portion X2 on the two sides.

  Therefore, in the step (3), the end portion 7 of the outer covering material 3 left outside the welded portion X2 on the two sides is cleaned in the same manner as described above, and further in the same manner as described above in the step (4). About both the welding part X2 of a side, while having predetermined overlap width (w5) inside from the outer side of the welding part X2, each heat welding layer 1 cleaned by the process (3) was heat-welded. The protective weld Y is formed with a width (w4) that has a region.

  As described above, in the preferable manufacturing method of the present invention, even when the method shown in FIG. 2 is adopted, by adding simple steps (3) and (4II) to the conventional manufacturing method of the vacuum heat insulating material, a vacuum is obtained. Similarly to the heat insulating material 100A-II, it is possible to easily and economically manufacture the vacuum heat insulating material 100B-II in which the decrease in the degree of vacuum is further suppressed in the long-term use.

  FIG. 8 is a general diagram of the vacuum heat insulating material 100A-I and the vacuum heat insulating material 100A-II (hereinafter, the vacuum heat insulating material 100A-I and the vacuum heat insulating material 100A-II are collectively referred to as “vacuum” according to the schematic diagram shown in FIG. 1 described above. It is the flowchart which showed the flow of the (1)-(4) process at the time of manufacturing the heat insulating material 100A ". FIG. 9 is a general term for the vacuum heat insulating material BI and the vacuum heat insulating material 100B-II (hereinafter referred to as the vacuum heat insulating material 100B-I and the vacuum heat insulating material 100B-II) according to the schematic diagram shown in FIG. It is the flowchart which showed the flow of the (1)-(4) process at the time of manufacturing "vacuum heat insulating material 100B."

  As described above, the method for manufacturing the vacuum heat insulating material according to the embodiment of the present invention has been described by taking the vacuum heat insulating materials 100A and 100B as an example with reference to the schematic diagrams shown in FIGS. 1 and 2. As long as it is not contrary to the above, the conditions in each step, the order of steps, and the like can be appropriately changed. Further, steps other than those described above may be provided as necessary.

  For example, for a vacuum heat insulating material having a welded portion X formed in a frame shape with four sides, a welded portion that is a welded portion before storage that is heat-welded before storing the core material in step (1) as necessary. The core material is housed in a jacket material that does not have X1, and in step (2), three sides are thermally welded in step (2a) to form weld portion X2, and the remaining one side is decompressed in step (2b). The welded portion X2 may be formed by heat welding underneath. In that case, the protective welding layer Y is formed by the steps (3) and (4) in the same manner as described above for all four sides of the welded portion X.

[Vacuum insulation]
The vacuum heat insulating material of the present invention is housed in a reduced pressure state inside a jacket material in which a film having a heat-welded layer and an airtight layer is arranged so that the heat-welded layers face each other. The outer cover material is a vacuum heat insulating material having a seal portion in which the heat-welded layers are adhered to each other by heat welding in a region covering the entire periphery of the core material outside the outer periphery of the core material. Thus, at least a part of the seal portion is a vacuum heat insulating material in which the amount of dust of the core material sandwiched by the seal portion in the outer region is smaller than that in the inner region of the seal portion.

  As such a vacuum heat insulating material, for example, the vacuum heat insulating material obtained by the manufacturing method of the present invention, specifically, the vacuum heat insulating material shown in FIGS. 1, 5A, 5B, 6A, 6B, and FIG. 100A and the vacuum heat insulating material 100B shown by FIG. 2 are mentioned.

  5A and 5B, a vacuum heat insulating material 100A-I includes a covering material 3 in which a film having a heat-welding layer 1 and an airtight layer 2 are arranged so that the heat-welding layers 1 face each other, and a covering material. 3 is provided with a core material 4 housed in a decompressed state, and the outer cover material 3 is adhered to the entire area around the core material 4 outside the outer periphery of the core material 4 by heat welding. Having a sealed portion. The seal part is formed outside the welded part (pre-storage welded part) X1 formed before the core material is stored, the welded part (post-storage welded part) X2 and the welded part X2 formed after the core material is stored. It consists of a protective welding part Y (including an unwelded part between the welding part X2 and the protective welding part Y).

  6A and 6B, a vacuum heat insulating material 100A-II includes a covering material 3 in which a film having a heat welding layer 1 and an airtight layer 2 are arranged so that the heat welding layers 1 face each other, and a covering material 3 The core material 4 is housed in a decompressed state inside the outer cover material 3, and the outer cover material 3 is in close contact with the heat-welding layer 1 by heat welding in a region covering the entire periphery of the core material 4 outside the outer periphery of the core material 4. It has a seal part. The seal part partially overlaps the welded part (pre-storage welded part) X1 formed before the core material is stored, the welded part (post-storage welded part) X2 and the welded part X2 formed after the core material is stored. It consists of the protective welding part Y formed in this.

  In the vacuum heat insulating material 100A-I, although not illustrated, a seal portion including a welded portion X2 and a protective welded portion Y formed outside the welded portion X2 and an unwelded portion between the welded portion X2 and the protective welded portion Y. In S, the outer region, here, the welded portion X2 having a predetermined width (w8), compared to the inner region of the seal portion S, here, the formation region of the welded portion X2 having a predetermined width (w2). The amount of dust sandwiched between the non-welded portion between the protective welded portion Y and the protective welded layer Y having a predetermined width (w4) is small.

  In the vacuum heat insulating material 100A-II, as shown in FIG. 7, the seal portion S including the welded portion X2 and the protective welded portion Y formed so as to partially overlap the welded portion X2 is disposed inside the seal portion S. Compared with the formation region of the welded portion X2 having a predetermined width (w2) in this region, the outer region, here, the overlapping portion with the welded portion X2 in the protective welded layer Y having the predetermined width (w6) The amount of dust 6 sandwiched by the seal portion in the region excluding the region is small. Specifically, the width (w2) of the welded portion X2 and the width (w6) of the region excluding the overlapping portion with the welded portion X2 in the protective welded layer Y are as described above.

  In addition, the dust 6 shown in FIG. 7 is shown as all the dusts including the dust resulting from the core material 4. The dust 6 is mainly caused by the core material 4, and it can be said that the dust amount of the core material in the seal portion S of the vacuum heat insulating material 100A is smaller in the outer region than in the inner region.

  The jacket material and the core material in the vacuum heat insulating material of the present invention can be the same as described in the above-described method for manufacturing a vacuum heat insulating material of the present invention, including preferred embodiments. For example, with respect to the core material in the vacuum heat insulating material of the present invention, a compression molded body including a powder and a fiber body is preferably used.

  The vacuum heat insulating material according to the embodiment of the present invention has been described above by taking the vacuum heat insulating material 100A-I and the vacuum heat insulating material 100A-II shown in FIGS. 1, 5A, 5B, 6A, 6B, and 7 as examples. However, in the vacuum heat insulating material of the present invention, the shape, material, and the like of each constituent member can be appropriately changed within the limits not departing from the spirit of the present invention. Moreover, you may provide structural members other than having demonstrated above as needed.

  A vacuum heat insulating material having the same configuration as that of the vacuum heat insulating material 100A-II was produced by the same manufacturing method as shown in FIG. 1, and the amount of dust in the seal portion was observed and evaluated. In the following description, the same reference numerals as those shown in FIG.

(Manufacture of core material)
Silica magnesia calcia fiber (trade name “Super Wool Bulk”) with respect to 100 parts by weight of fumed silica (trade name “CAB-O-SIL H300”, specific surface area 300 m ² / g, manufactured by Cabot Specialty Chemicals Inc.) 10 parts by weight of “Nippon Nippon Thermal Ceramics Co., Ltd.” was added and mixed with a blender to obtain a mixed powder. The obtained mixed powder is put into a mold, pressed to form a flat plate having a length of 80 mm × width of 80 mm × thickness of 15 mm, and then heated at 200 ° C. for 1 hour to form a core 4. Was made.

(Process (1))
Two square films of the same size formed by laminating the heat-welding layer 1 and the air-tight layer 2 are overlapped with the heat-welding layers 1 of the respective films facing each other, and the three sides are heat-sealed and the welded portion Commercially available transparent gas barrier film (outer material) 3 (trade name “standard for vacuum packaging with magic cut”) configured to have X1 and the other side is not heat-sealed but has an opening 5 "Bag, Hiryu", manufactured by Asahi Kasei Pax Corporation).
The core material 4 obtained above was inserted into the inside of the opening 5 of the transparent gas barrier film 3 to obtain a core material housing material 10a.

(Process (2))
About the core material housing material 10a obtained above, the width (w3) of the end 7 of the transparent gas barrier film 3 is about 25 mm in a state where the inside of the chamber is decompressed using a vacuum chamber with a heat sealing function. In this manner, the remaining unwelded part on one side was heat-sealed with a width (w2) of 10 mm to form a welded part X2 and sealed to obtain a vacuum heat insulating material precursor 10b.

  When the vacuum insulator precursor 10b taken out was observed, it was found that the powder remained inside the welded portion X2 of the transparent gas barrier film 3 and on the inner surface side of the film. It was observed that the powder remained at various locations on the inner surface side of the film also in the portion X2 and the end portion 7 left on the outer peripheral side.

(Process (3))
Next, the powder adhering to the inner surface of the transparent gas barrier film 3 left on the outer side of the welded portion X2, that is, the surface of the opposing thermal welding layer 1, is left at least visually by using a wet tissue. Removed to a lesser extent. Thereafter, the cleaned part was sufficiently dried.

(Step (4II))
A heat seal portion having a width (w4) of 12 mm was formed as a protective weld portion Y so as to be parallel to the weld portion X2 on the outside of the weld portion X2 so that the width (w5) substantially overlaps with the weld portion X2. . When comparing a region where the width (w6) excluding the overlap width region from the welded portion X2 and the protective weld portion Y is 10 mm, a region excluding the overlap width region from the protective weld portion Y (the cleaning is performed). In this case, no residual powder was observed visually.

  The vacuum heat insulating material of the present invention can be applied to places where energy saving is required and heat insulation, cold insulation, and heat insulation are required. Specifically, for example, residential and building walls / roofs / floors / piping, solar / heat facilities, etc .; constant temperature baths, water heaters, hot water tanks, rice cookers, refrigerators, freezers, cold storage / cold storage tanks, Refrigerated gas tanks, vending machines, cooler boxes, cold covers, heat insulation and other cold insulation fields; notebook and liquid crystal projectors, photocopiers, batteries, fuel cells and other electrical and electronic equipment, and industrial equipment fields such as semiconductor manufacturing equipment Mobile fields such as automobiles, buses, trucks, cold trucks, trains, freight cars, ships, etc .; can be applied to plant piping, etc.

100A-I, 100A-II, 100B-I, 100B-II ... Vacuum heat insulating material, 10a ... Core material housing material, 10b ... Vacuum heat insulating material precursor 1 ... Heat welding layer, 2 ... Airtight layer, 3 ... Outside Substrate, 4 ... core material, 5 ... opening, 6 ... dust, 7 ... end X1 ... welded part formed before storage of core material (welded part before storage), X2 ... formed after storage of core material Welded part (welded part after storage), Y ... Protective welded part

Claims (6)

It is a vacuum heat insulating material having a jacket material formed by arranging a film having a heat welding layer and an airtight layer so that the heat welding layers face each other, and a core material housed inside the jacket material, The jacket material has a welded portion in which the heat-welded layers are heat-welded with a predetermined width over the entire periphery of the core material, and a protective welded portion formed on the outside of the welded portion, and the inside is in a reduced pressure state. A method of manufacturing a vacuum insulation material,
A step of storing the core material in the outer cover material having an unwelded portion in which the portion to be the welded portion is not welded in the welded portion;
About the jacket material containing the core material, the heat-welded layers of the unwelded portions are heat-welded in advance, leaving a part necessary for decompression, or without heat-welding, It is a step of heat-welding the heat-welded layers under reduced pressure so that the whole is in a welded state, and for any of the heat-welded, a predetermined width from the outer edge of the jacket material containing the core material A process to be performed leaving the edge,
Cleaning the surface of the opposing heat-welded layer at the end of the outer cover material that is left outside the post-storage welded portion that has been heat-welded after the core material is stored; A step of forming the cleaned heat-welded layers on the outside of the post-welded portion so as to have a region where heat-welded with each other;
The manufacturing method of the vacuum heat insulating material which has this. The vacuum heat insulating material has a protective weld part formed on the outside of the weld part so as to partially overlap at least a part of the weld part,
The step of forming the protective welded portion includes a region where the protective welded portion has a predetermined overlapping width from the outer side of the post-storage welded portion to the inner side and the cleaned heat welded layers are thermally welded to each other. A step of forming to have
The manufacturing method of the vacuum heat insulating material of Claim 1.   The method for producing a vacuum heat insulating material according to claim 1 or 2, wherein the core material is a compression molded body containing powder and a fiber body.   The method for manufacturing a vacuum heat insulating material according to claim 2 or 3, wherein an overlap width between the protective welded portion and the post-storage welded portion is 1 to 5 mm. An outer cover material in which a film having a heat-welded layer and an airtight layer is disposed so that the heat-welded layers face each other; and a core material housed in a reduced pressure inside the outer cover material, The material is a vacuum heat insulating material having a seal portion in which the heat-welding layers are in close contact with each other by heat-welding in a region covering the entire periphery of the core material outside the outer periphery of the core material,
A vacuum heat insulating material in which at least a part of the seal portion has a smaller dust amount of the core material sandwiched by the seal portion in an outer region than in an inner region of the seal portion.   The vacuum heat insulating material according to claim 5, wherein the core material is a compression molded body including powder and a fiber body.

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