JP2006161939A - Vacuum thermal insulating material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vacuum thermal insulating material having excellent close adhesion property of an external wrapping material and a core material and capable of preventing breakage of the external wrapping material irrespective of a vacuum thermal insulating material having a through hole part and/or a cut-out part and a vacuum thermal insulating material having a plurality of core materials. <P>SOLUTION: This vacuum thermal insulating material is provided with at least the core material and the external wrapping material capable of maintaining the inside into a pressure reduced condition. The core material is a sheet-like fiber collected body made of organic fibers. This vacuum thermal insulating material has the through hole part and/or the cut-out part, and rear surfaces of the external wrapping material are mutually sealed along a peripheral fringe part of the external wrapping material and an inner peripheral part of the through hole part and/or the cut-out part. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to a vacuum heat insulating material used as a heat insulating material for a refrigerator, a vending machine, a cold box, a cold car, a hot water storage tank, an ice storage tank, a vacuum heat insulating pipe, a molded ceiling of an automobile, a bathtub, and the like.

  Conventionally, heat insulating materials having various structures and performances are used for refrigerators, vending machines, cold storage boxes, cold storage vehicles, hot water storage tanks, ice storage tanks, vacuum insulation pipes, automobile molded ceilings, bathtubs, and the like. In recent years, a vacuum heat insulating material having a very excellent heat insulating property has been used in many applications. The vacuum heat insulating material generally has a structure in which a core material is filled in an outer packaging material made of a gas barrier metal deposition film or the like, and the inside thereof is decompressed and sealed. The heat insulation, productivity, and handling performance of such a vacuum heat insulating material are greatly influenced by the core material, but as a core material currently widely used, a fibrous core material, a powdered core material, an open-cell resin foam And a core material made of an open-cell ceramic foam.

  The core material using the open-cell foam is very excellent not only in handleability but also in lightness and the like, but has a surface inferior in heat insulation properties compared with a fibrous material such as glass fiber. In addition, the powdery core material is extremely reduced in lightness and handleability. Therefore, a fiber core material, particularly a core material using inorganic fibers such as glass fiber and rock wool has been frequently used in recent years.

On the other hand, the use of the vacuum heat insulating material has been spreading in recent years. For example, the vacuum heat insulating material is wrapped around a cylindrical tank in a water supply device or a cylindrical pipe in a piping facility from the outer periphery thereof to cover the tank and the pipe for improving the thermal efficiency. In such various applications, processing such as through holes, notches and bending is required to provide wiring, piping, and the like in the vacuum heat insulating material. 2. Description of the Related Art Conventionally, a technique in which gas barrier outer covering materials are sealed along an inner peripheral portion of a through-hole portion or a notch portion has been disclosed (Patent Document 1). This is because a flat heat insulating core material provided with a through hole and / or a notch is accommodated in the bag through the bag opening made of the gas barrier packaging material, and the bag is evacuated from the bag opening. While maintaining the desired degree of vacuum, the gas barrier packaging material is fused together along the inner periphery of the through hole and / or the notch, and the gas barrier packaging material at the opening of the bag is fused. A manufacturing method for forming a worn seal portion is used.
Japanese Patent Application Laid-Open No. 08-303686

  However, when evacuating the outer cover material (outer packaging material) on the inner periphery of the through hole or notch or sealing the outer cover material, the film extension of the outer cover material or the film type of the outer cover material However, in a hard core material such as an open-cell resin foam or inorganic powder, a large load is applied to the outer cover material at the inner peripheral portion, and the outer cover material is damaged or between the outer cover material and the core material. A large void portion is generated. The same problem arises when a plurality of core materials are stored in the outer packaging material and the outer packaging material back surfaces are sealed along the peripheral edge of the outer packaging material and the outer peripheral portion of each core material. In particular, problems are likely to occur during the evacuation process in a portion between a plurality of core members.

  It is naturally possible to simply chamfer the core material itself to improve the adhesion between the jacket material and the core material, but the core material needs to be chamfered, and productivity is reduced. In particular, in the case of an inorganic core material, the chamfering process itself is complicated.

In view of the above circumstances, the present invention has good adhesion between the outer packaging material and the core material even in the case of a vacuum heat insulating material having a through-hole portion and / or a notch or a vacuum heat insulating material having a plurality of core materials. An object of the present invention is to provide a vacuum heat insulating material with little damage to the outer packaging material.

According to the present invention, the following inventions 1 to 7 are provided.
1. In a vacuum heat insulating material comprising at least a core material and an outer packaging material that can store the core material and maintain the inside in a reduced pressure state, the core material is a sheet-like fiber assembly made of organic fibers, and the vacuum heat insulating material Has a through-hole portion and / or a cutout portion, and the outer packaging material back surfaces are sealed along the peripheral edge portion of the outer packaging material and the inner peripheral portion of the through-hole portion and / or the cutout portion. Vacuum insulation material.
2. In a vacuum heat insulating material comprising at least a core material and an outer packaging material that can store the core material and maintain the inside in a reduced pressure state, the core material is a sheet-like fiber assembly made of organic fibers, and the outer packaging material includes Is a vacuum heat insulating material characterized in that at least two or more core materials are accommodated, and the back surfaces of the outer packaging materials are sealed along the peripheral edge portion of the outer packaging material and the outer peripheral portion of each core material.
3. 3. The vacuum heat insulating material according to 1 or 2 above, wherein the core material is a sheet-like fiber assembly made of polyester fibers.
4). 3. The vacuum heat insulating material according to 1 or 2 above, wherein the core material is a sheet-like fiber assembly made of polyethylene terephthalate fibers.
5. The vacuum heat insulating material according to any one of 1 to 4 above, wherein an average fiber length of the sheet-like fiber aggregate is 10 to 150 mm.
6). The vacuum heat insulating material according to any one of 1 to 5 above, wherein the core material is a sheet-like fiber aggregate without using a binder.
7). 7. The vacuum heat insulating material according to 6 above, wherein the core material is formed into a sheet-like fiber aggregate by a needle punch method.

  Since the vacuum heat insulating material of this invention has a through-hole part and / or a notch part, or has a some core material, a vacuum heat insulating material can be expand | deployed for various uses. Furthermore, when an organic fiber-based core material, particularly a polyester fiber core material, is used, since the fiber has high flexibility, a plurality of core materials are encased in the inner periphery of the through hole and / or the notch. In the outer peripheral portion of each core material when housed in the material, the outer packaging material is hardly damaged during the evacuation process, and the adhesion between the outer packaging material and the core material is good.

  The vacuum heat insulating material of the present invention comprises at least a core material and an outer packaging material that can accommodate the core material and maintain the inside in a reduced pressure state.

The core material used in the present invention is a sheet-like fiber assembly made of organic fibers.
Organic fibers include polyester fiber, acrylic fiber, polyethylene fiber, polypropylene fiber, nylon fiber, polyvinyl alcohol fiber, polyurethane fiber, polynosic fiber, rayon fiber, synthetic fiber, hemp, silk, cotton, wool, pulp, coconut Organic fibers such as natural fibers are used, and the fibers are used as a single fiber or a plurality of mixed fibers. Polyester fibers are preferred from the viewpoint of low hygroscopicity, excellent heat insulation, and excellent flexibility, mass productivity, and cost. In the present invention, the polyester fiber means a fiber composed of a polymer in which chemical structural units are mainly bonded by an ester bond, and the production method is not particularly limited. For example, a dicarboxylic acid component and a diol The polyester fiber obtained by reaction with a component may be sufficient, or the polyester fiber obtained by reaction of the hydroxycarboxylic acid component which has a hydroxyl group and a carboxyl group in 1 molecule may be sufficient. Specific examples include polyethylene terephthalate (PET) fiber, polybutylene terephthalate (PBT) fiber, polypropylene terephthalate fiber, and polyarylate fiber. Of course, there is no problem even if recycled PET fibers are used. Furthermore, in view of heat insulating properties, mass productivity, etc., polyethylene terephthalate (PET) fibers are particularly preferable.

In the case of using a polyester fiber, the preferred fiber thickness is about 1 to 6 denier. This is because if it is less than 1 denier, it becomes difficult to process into a sheet shape, and if it is 6 denier or more, the heat insulation tends to decrease. As an average fiber diameter, it is 9-25 micrometers, Preferably it is 11-17 micrometers. Furthermore, a preferable fiber length (average fiber length) is 10 to 150 mm. If it is less than 10 mm, it is extremely difficult to form a sheet. In particular, it is very difficult to make fibers less than 10 mm in a sheet state with orientation without using a binder. Moreover, if it is 150 mm or more, density unevenness tends to occur. In addition, the fiber length of 20 mm to 80 mm is preferable from the viewpoint of flexibility and productivity in the vacuum exhaust process.

  In the present invention, “sheet shape” means having a flat plate shape. When the fiber assembly is used as it is, if the core material is not in the form of a sheet, the handling of the core material will be reduced, so the process of storing the core material in the outer packaging will become too complicated and workability will deteriorate. To do.

When providing a through-hole part or a notch part in this invention, the part used as the same through-hole and the part used as a notch are provided also in the core material. In addition, the said part may be previously provided as a sheet-like fiber assembly core material, and when inserting in an outer packaging material, you may make it a through-hole part or a notch part. Furthermore, the position where the through hole portion and the notch portion are provided is appropriately determined depending on the use of the vacuum heat insulating material to be obtained, and the shape and size of the through hole portion and the notch portion are determined according to these uses, i.e. It can be determined as appropriate according to the cross-sectional shape and size of the wiring to be penetrated by using the device, the size, and the shape and size of the portion using the notch. The cross-sectional shape of the through-hole is usually a polygon such as a circle, a quadrangle, a hexagon, etc., but in order to prevent wrinkling of the outer packaging material, the through-hole part and the notch part are preferably close to a circle. Even in the case of providing rectangular or polygonal through holes, it is preferable to chamfer the corners of the four corners into curved surfaces.

The thickness of the sheet-like fiber assembly (core material) is set to be about 0.1 mm to 15 mm after evacuation. In particular, the thickness after evacuation is preferably about 0.5 mm to 5 mm in consideration of damage to the outer packaging material and the adhesion between the outer packaging material and the core material. In addition, the sheet-like fiber assembly may consist of a single-layer sheet, but when a thick core material having a thickness of about 5 mm after evacuation is formed with a single-layer sheet of polyester fiber, the sheet manufacturing is Since it is difficult, it is preferable to laminate two or more sheets to form a sheet-like fiber assembly (core material). Furthermore, the fiber assembly is preferably processed without using other materials such as a binder. For example, it is processed into a sheet shape by a needle punch method or the like. In addition, about the operation | work which accommodates a core material in an outer packaging material, since it is preferable to make it shape-retain using a binder, when using a binder, it is necessary to consider the damage of an outer packaging material, and adhesiveness with a core material. Further, the fiber itself used for the core material may have a core-sheath structure so as to have a fusion property, and may be used in place of the binder. In this case, there is little risk of outgassing. The needle punching method is a method of repeatedly piercing or pulling up many needles with hooks against a polyester fiber lump in which the directions of fibers are aligned to some extent, that is, a polyester fiber web. It is the method of making it into a sheet form by mutually entanglement.

As the outer packaging material for storing the core material, any material can be used as long as it has gas barrier properties and can maintain the inside at a reduced pressure. Preferable specific examples include, for example, a gas barrier film having a four-layer structure of nylon, aluminum vapor-deposited PET (polyethylene terephthalate), aluminum foil, and high-density polyethylene as the innermost layer, from the outermost layer, polyethylene terephthalate resin, intermediate Gas barrier film consisting of aluminum foil as the layer, high density polyethylene resin as the innermost layer, PET resin as the outermost layer, ethylene-vinyl alcohol copolymer resin having an aluminum vapor deposition layer as the intermediate layer, and gas barrier consisting of high density polyethylene resin as the innermost layer A film etc. are mentioned.

  In the outer packaging material of the vacuum heat insulating material of the present invention, from the viewpoint of further improving heat insulation over time, a gas generated inside the vacuum heat insulating material after evacuation, for example, outgas and moisture generated from the core material, and A gas adsorbing material that adsorbs gas and moisture entering from the outside may be stored together with the core material.

  A preferred embodiment of the manufacturing process of the vacuum heat insulating material of the present invention will be described below with reference to FIGS. FIG. 1 is a schematic plan view of a vacuum heat insulating material of the present invention having a through hole. FIG. 2 is a schematic plan view of the vacuum heat insulating material of the present invention having a notch. FIG. 3 is a schematic plan view of the vacuum heat insulating material of the present invention having a plurality of core materials. FIG. 4 is a schematic view showing a cross-sectional structure of the vacuum heat insulating material of the present invention having a through-hole portion.

  The fiber assembly is formed into a sheet shape by a needle punch method or the like to obtain a core material. The obtained core material is cut into an appropriate size and shape (for example, a quadrangle). In the case of a through-hole product, a through portion is provided in the core material itself, and in the case of a notch product, the core material itself is cut. Make a notch. Both may be provided simultaneously. Subsequently, drying is performed to remove moisture contained in the inside. The drying is performed at 120 ° C. for about 1 hour, but it is preferable to vacuum dry at 120 ° C. in order to further remove moisture and the like of the polyester fiber. Furthermore, you may use together the drying by far infrared rays. About a vacuum degree, it is preferable to dry at about 0.5-0.01 Torr.

  Next, the core material 1 is inserted into a bag shape, that is, the outer packaging material 2 in which the three sides of the peripheral edge portion 3 are sealed. Since a plurality of core materials 1 are used, a plurality of core materials 1 are inserted. If necessary, a gas adsorbent is inserted together. In this state, it is put in a vacuuming device and evacuated under reduced pressure so that the internal pressure becomes a degree of vacuum of about 0.1 to 0.01 Torr. Thereafter, the bag-like opening which is the unsealed peripheral portion of the outer packaging material is sealed by heat sealing. In addition, the seal | sticker of the peripheral part 3 of an outer packaging material is a seal | sticker for maintaining the pressure reduction state after evacuation, and what is necessary is just to set suitably about a seal width, a seal position, etc. in the range which can maintain a pressure reduction state. For example, if the core material thickness after evacuation is about 0.5 to 15 mm, the seal width is preferably about 5 to 30 mm. In order to facilitate sealing, if a sealing portion is provided on the inner side from the outermost end portion of the outer packaging material while leaving a blank portion 9, a sealing failure hardly occurs and workability is good. The marginal part 9 may be bent at the time of use and used as it is, or may be cut off.

  With respect to the through hole product and the notch product, the through hole 4 and / or along the inner periphery (6.7) of the through hole 4 and / or the notch 5 or including the inner periphery. About the whole surface of the notch portion 5, the back surfaces of the outer packaging material are sealed by hot pressing or the like. If it is a multi-core material product, the outer packaging material back surfaces are sealed by hot pressing or the like along the outer peripheral portion 8 of each core material. Then, about a through-hole product and a notch product, the outer packaging material is cut out with a cutter etc. in the state which left the said inner peripheral part (6.7) sealed, and has the through-hole part 4 or the notch part 5. Vacuum insulation A is obtained. The inner peripheral portion (6.7) may be left to such an extent that the decompressed state after evacuation can be maintained, and the width of the sealed inner peripheral portion and the like are appropriately set within a range in which the decompressed state can be maintained. You only have to set it.

  If necessary, after completion of the vacuum heat insulating material, it may be pressed, the thickness of the core material can be adjusted, and the density can be controlled.

<Example 1>
As a core material, a polyester fiber (polyethylene terephthalate fiber) having a fiber thickness of 1.5 denier, an average fiber diameter of 12 μm, and a fiber length of 51 mm was used. The polyester fiber was processed into a sheet by a needle punch method. The sheet basis weight immediately after processing was 660 g / m ² . The sheet was cut into a size of 200 mm × 200 mm. Furthermore, the fiber part about 100 mm x 100 mm part of the said sheet | seat center part was cut out, and the through-hole of the said size was provided. The sheet having the through holes was dried at a temperature of 110 ° C. for 1 hour. The sheet was inserted into a gas barrier film outer packaging material having a four-layer structure of nylon, aluminum-deposited PET, aluminum foil, and high-density polyethylene. Thereafter, evacuation was performed with an evacuation device so that the internal pressure was 0.01 Torr, and the unsealed portion of the peripheral portion of the outer packaging material, that is, the bag opening portion was sealed by heat sealing. The evacuation time is 180 seconds. The obtained vacuum heat insulating material has a size of 200 mm × 200 mm and a thickness of 3 mm. Furthermore, the back surface of the outer packaging material was sealed by fusing a 100 mm × 100 mm through-hole portion by hot pressing. Then, about the through-hole part, the center 70mm x 70mm range was cut out. Therefore, a vacuum heat insulating material in which a seal portion having a width of 15 mm was formed along the inner peripheral portion of the through-hole portion was obtained. The vacuum heat insulating material had a through-hole portion and no damage to the outer packaging material at the inner peripheral portion of the through-hole portion, and was excellent in adhesion between the core material and the outer packaging material.

<Example 2>
As the core material, the same polyester fiber as in Example 1 was used. The polyester fiber was processed into a sheet by a needle punch method. The sheet basis weight immediately after processing was 660 g / m ² . The sheet was cut into a size of 200 mm × 200 mm. Furthermore, the fiber part about the 100 mm x 100 mm part of the said sheet | seat edge part was notched, and the notch of the said size was provided. The sheet having the notch was dried at a temperature of 110 ° C. for 1 hour. The sheet was inserted into a gas barrier film outer packaging material having a four-layer structure of nylon, aluminum-deposited PET, aluminum foil, and high-density polyethylene. Thereafter, evacuation was performed with an evacuation device so that the internal pressure was 0.01 Torr, and the unsealed portion of the peripheral portion of the outer packaging material, that is, the bag opening portion was sealed by heat sealing. The evacuation time is 180 seconds. The obtained vacuum heat insulating material has a size of 200 mm × 200 mm and a thickness of 1 mm. Further, the back surface of the outer packaging material was sealed by fusing a notch portion of 100 mm × 100 mm by hot pressing. Then, about the notch part, the range of 60 mm x 60 mm was cut out. Therefore, the vacuum heat insulating material in which the seal part of 20 mm width was formed along the inner peripheral part of the notch part was obtained. The vacuum heat insulating material was excellent in the adhesion between the core material and the outer packaging material, having a notch portion and no damage to the outer packaging material at the inner peripheral portion of the notch.

<Example 3>
As the core material, the same polyester fiber as in Example 1 was used. The polyester fiber was processed into a sheet by a needle punch method. The sheet basis weight immediately after processing was 660 g / m ² . The sheet was cut into a size of 90 mm × 90 mm. Four of the sheets were dried at a temperature of 110 ° C. for 1 hour. The sheet was inserted into a gas barrier film outer packaging material having a four-layer structure of nylon, aluminum-deposited PET, aluminum foil, and high-density polyethylene. The insertion positions were such that each core member had an interval of 20 mm, and the entire four sheets were inserted to be 200 mm × 200 mm. Thereafter, evacuation was performed with an evacuation device so that the internal pressure was 0.01 Torr, and the unsealed portion of the peripheral portion of the outer packaging material, that is, the bag opening portion was sealed by heat sealing. The evacuation time is 180 seconds. The obtained vacuum heat insulating material has a size of 200 mm × 200 mm and a thickness of 3 mm. Furthermore, the outer packaging material back surfaces were sealed together by hot pressing along the outer periphery of each core member having a size of 20 mm × 20 mm. The vacuum heat insulating material had four core materials in the outer packaging material, and was excellent in adhesion between the core material and the outer packaging material without damage to the outer packaging material at the outer peripheral portion of each core material.

  The vacuum heat insulating material of the present invention can also be applied as a vacuum heat insulating material used as a heat insulating material for refrigerators, vending machines, cold storage boxes, cold storage vehicles, hot water storage tanks, ice storage tanks, vacuum heat insulating piping, automobile molded ceilings, bathtubs, etc. Yes, it can be used for a wider range of applications.

Schematic plan view of a vacuum heat insulating material having a through hole portion of the present invention Schematic plan view of a vacuum heat insulating material having a notch according to the present invention Schematic plan view of a vacuum heat insulating material having a plurality of cores of the present invention The schematic diagram which shows the cross-section of the vacuum heat insulating material which has a through-hole part of this invention.

Explanation of symbols

A: vacuum heat insulating material, 1: core material, 2: outer packaging material, 3: peripheral edge portion of outer packaging material, 4: through hole portion, 5: notch portion, 6: inner circumferential portion of through hole portion, 7: notch Inner peripheral part, 8: outer peripheral part of core material

Claims (7)

  In a vacuum heat insulating material comprising at least a core material and an outer packaging material that can store the core material and maintain the inside in a reduced pressure state, the core material is a sheet-like fiber assembly made of organic fibers, and the vacuum heat insulating material Has a through-hole portion and / or a cutout portion, and the outer packaging material back surfaces are sealed along the peripheral edge portion of the outer packaging material and the inner peripheral portion of the through-hole portion and / or the cutout portion. Vacuum insulation material.   In a vacuum heat insulating material comprising at least a core material and an outer packaging material that can store the core material and maintain the inside in a reduced pressure state, the core material is a sheet-like fiber assembly made of organic fibers, and the outer packaging material includes Is a vacuum heat insulating material characterized in that at least two or more core materials are accommodated, and the back surfaces of the outer packaging materials are sealed along the peripheral edge portion of the outer packaging material and the outer peripheral portion of each core material.   The vacuum heat insulating material according to claim 1 or 2, wherein the core material is a sheet-like fiber assembly made of polyester fibers.   The vacuum heat insulating material according to claim 1 or 2, wherein the core material is a sheet-like fiber aggregate made of polyethylene terephthalate fibers. The vacuum fiber heat insulating material according to any one of claims 1 to 4, wherein an average fiber length of the sheet-like fiber aggregate is 10 to 150 mm.   The vacuum heat insulating material according to any one of claims 1 to 5, wherein the core material is a sheet-like fiber assembly without using a binder. The vacuum heat insulating material according to claim 6, wherein the core material is formed into a sheet-like fiber aggregate by a needle punch method.