JP2008082416A - Vacuum thermal insulation material and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vacuum thermal insulation material usable in a high temperature area of 100 to 500 °C, and capable of surely adhering a joining part. <P>SOLUTION: This vacuum thermal insulation material 10 is provided by putting the inside of an external facing material in a vacuum state, by joining the joining part 2, after exhausting the inside in a vacuum, by wrapping a filler 3 of laminating an inorganic fiber sheet and stainless foil and a getter material 4 by the external facing material composed of a stainless sheet 1 having the thickness of 0.02 mm to 0.05 mm. The joining part 2 is formed by arranging an Ag/Cu-based brazing material 5 having the thickness of 0.01 to 0.1 mm between an electrolytic nickel plating layer 6, by applying the electrolytic nickel plating layer 6 having the thickness of 3 μm or more to an interface surface of the opposed stainless sheets 1. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a vacuum heat insulating material used in a high temperature range up to 500 ° C. mainly in an industrial furnace, an incinerator, a power plant or the like, and a method for manufacturing the vacuum heat insulating material.

The heat insulating performance of the heat insulating material is expressed by thermal conductivity, and the lower the thermal conductivity, the higher the heat insulating effect. As a technique for reducing the thermal conductivity, there is known a “vacuum heat insulating material” that exhibits high heat insulating performance by reducing the thermal conductivity by making the inside of the heat insulating material into a vacuum state. This vacuum heat insulating material is widely known as a vacuum heat insulating material in which a metal foil laminated or metal-deposited resin laminated film is used as an exterior material, and a fiber or inorganic powder is included and the inside is evacuated. It has been put to practical use in a cold storage container or the like (Patent Document 1).
Further, Patent Document 2 describes a vacuum heat insulating material for the purpose of reducing the amount of heat transfer through the metal foil using a stainless steel metal foil as the exterior material. Similarly, the covering material (exterior material) is composed of a stainless steel foil having a thickness of 0.3 mm or less, and due to the synergistic effect of the low thermal conductivity of stainless steel and the high thermal resistance by having a thickness of 0.3 mm or less, Patent Document 3 describes a vacuum heat insulating material that suppresses the thermal conductivity around the outer periphery.
Furthermore, Patent Document 4 describes a vacuum structure for the purpose of heat insulation or heat retention at 100 ° C to 500 ° C.

JP-A-2005-351405 Japanese Patent Application Laid-Open No. 07-098091 JP 08-159376 A JP 2006-081608 A

However, Patent Documents 1 to 4 have the following problems.
(1) In Patent Document 1, the vacuum heat insulating material using the above-described metal foil laminated or metal-deposited resin laminated film as an exterior material is sealed with a resin adhesive, and therefore has a high temperature of 100 ° C. or higher. There is a problem that cannot be used in the area.
(2) In Patent Document 2, when the outer members are joined by welding metal foils or joining with a low melting point metal or a low melting point ceramic, there is a problem that the welded portion is easily damaged or a joining failure due to the low melting point metal is likely to occur.
(3) In Patent Document 3, the thickness of the stainless steel foil used as the coating material (exterior material) is “0.3 mm or less, preferably 0.1 mm” (the same specification [0017]), (Same specification [0018]), but sealing by seam welding requires a thickness of the joining member of at least 0.5 to 0.8 mm. Stainless steel seam welding is difficult. In particular, when the thickness of the joining member is 0.1 mm or less, the exterior material is highly likely to be dissolved during seam welding, and seam welding is difficult.
(4) In patent document 4, although the vacuum double container which consists of an inner member and an outer member is made into the structure made from stainless steel, and the multilayer heat insulating material was provided inside, there is no description regarding the joining method. In general, joining of stainless steel is difficult to braze at 1000 ° C. or less because a passive film is formed on the surface. When performing brazing joining, the passive film is reduced and joined at 1000 ° C. or more. Or a method of brazing using a highly reducing flux is known. However, if brazing is performed in an atmosphere of 1000 ° C. or higher, there is a high possibility that the heat insulating material filled therein will be affected, and the physical properties such as the thermal conductivity of the heat insulating material will change. Further, in joining using a highly reducing flux, there is a problem that the flux component remains in the heat insulating material filled therein, and the degree of vacuum inside the vacuum heat insulating material is lowered.

  Then, this invention solves such a subject, and while ensuring the adhesion | attachment of the junction part of an exterior material in a 100-500 degreeC high temperature area, the highly heat-insulating vacuum heat insulating material provided with low thermal conductivity is provided. It is intended to provide.

In order to achieve the above object, the first invention includes a filler having a heat insulating property, an exterior material that covers and seals the filler, and a vacuum thermal insulation material in which the interior of the exterior material is a vacuum space. It is made of a sheet and is brazed and joined, and the joint portion of the exterior material is plated.
In the second invention, the filler is made of silica-based inorganic fibers, the exterior material is made of a stainless steel sheet having a thickness of 0.02 to 0.05 mm (preferably 0.03 to 0.04 mm), and the plating treatment is electrolytic. It is a nickel plating process.
In the third invention, the filler is made of a laminate in which a silica-based inorganic fiber sheet and a metal foil are laminated, and the outer packaging material has a thickness of 0.02 to 0.05 mm (preferably 0.03 to 0.04 mm). It consists of a stainless steel sheet, and the plating process is an electrolytic nickel plating process.
The fourth invention is characterized in that an additive mainly composed of zirconium / aluminum alloy or zirconia / vanadium alloy is added to the vacuum heat insulating material.
According to a fifth aspect of the present invention, there is provided a vacuum heat insulating material manufacturing method in which a heat-insulating filler is covered and sealed with an exterior material, and the interior of the exterior material is a vacuum space. It is characterized in that the joint portion is plated and then brazed.
In the sixth aspect of the invention, the filler is made of silica-based inorganic fibers, the exterior material is made of a stainless steel sheet having a thickness of 0.02 to 0.05 mm (preferably 0.03 to 0.04 mm), and the plating treatment is electrolytic. It is a nickel plating process.
7th invention is a laminated body which the filler laminated | stacked the silica type inorganic fiber sheet | seat and metal foil, and an exterior material is 0.02-0.05 mm (preferably 0.03-0.04 mm) in thickness. It consists of a stainless steel sheet, and the plating process is an electrolytic nickel plating process.
The eighth invention is characterized in that it is conveyed into a vacuum furnace in a state where the joint portion of the exterior material is pressurized, and the joint portion of the exterior material is joined at a temperature higher than the operating temperature condition in the vacuum furnace. Is.
The ninth invention is characterized in that the inside of the vacuum furnace is maintained at 1 Pa or less, the temperature in the vacuum furnace is set to 780 to 820 ° C., and the joint portion of the exterior material is joined.

According to the said invention, it has the following effects.
(1) By plating the joints of exterior materials made of stainless steel, brazing at 780-820 ° C is possible without heating above the temperature at which the non-conductive film is reduced (about 1000 ° C) It is said.
(2) Since the exterior material is a stainless steel sheet having a thickness of 0.02 to 0.05 mm and the filler filled inside is a silica-based inorganic fiber, it can be used in a temperature range of 100 to 500 ° C. Yes, it can be constructed according to the shape of the object to be insulated. Moreover, since the temperature at the time of joining of an exterior material is 780-820 degreeC, the heat insulation characteristic of a filler is not impaired.
(3) The filler filled inside is a laminated structure in which a silica-based inorganic fiber sheet having a thickness of 0.5 to 2.0 mm and a metal foil having a thickness of 0.03 to 0.04 mm are laminated. Yes, since the exterior material is a stainless steel sheet with a thickness of 0.02 to 0.05 mm, a low thermal conductivity of 0.005 to 0.015 W / (m · k) has been achieved even if the thickness is 20 mm or less. It is possible to provide a vacuum insulation material.
(4) By adding an additive mainly composed of zirconium / aluminum alloy or zirconia / vanadium alloy together with the filler inside the vacuum heat insulating material, moisture, oxygen, nitrogen, etc. generated inside the vacuum heat insulating material The gas component is adsorbed to suppress a decrease in the degree of vacuum, and can be used for a long time.

Embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a cross-sectional view showing a vacuum heat insulating material according to the present invention. The vacuum heat insulating material 10 includes a filler 3 and a getter material 4 obtained by laminating an inorganic fiber sheet having a thickness of 0.5 to 2.0 mm and a stainless steel foil having a thickness of 0.03 to 0.04 mm. After wrapping with an exterior material made of a stainless sheet 1 having a thickness of 02 mm to 0.05 mm and evacuating the inside, the joining portion 2 is joined to bring the interior of the exterior material into a vacuum state. The thickness of the vacuum heat insulating material is about 20 mm. The purpose of adding the getter material 4 is that the vacuum heat insulating material 10 is exposed to a high temperature and reacts with gas components such as moisture, oxygen, and nitrogen generated from the filling material 3 filled therein, and thereby the inside of the vacuum heat insulating material 10 This is to maintain the degree of vacuum and prevent an increase in thermal conductivity. The material and addition amount of the getter material 4 are determined by the size of the filler, the type of filler, and the like.

  FIG. 2 shows details of the joining portion 2 of the stainless steel sheet 1. An electrolytic nickel plating layer 6 having a thickness of 3 μm or more is applied to the joining surface of the opposing stainless steel sheet 1, and an Ag / Cu brazing material 5 having a thickness of 0.01 to 0.1 mm is disposed between the electrolytic nickel plating layers 6. Is. By interposing the brazing material 5 between the electrolytic nickel plating layers 6, the stainless steel sheet 1 having a thickness of 0.02 mm to 0.05 mm can be securely bonded without being damaged even if the bonding portion 2 is plated. Can do.

  FIG. 3 is an explanatory view showing the arrangement of the brazing material. An electrolytic nickel plating layer 6 having a width of about 10 mm is applied to the end portion of the stainless steel sheet 1 that serves as the joining portion 2 (not shown), the brazing material 5 is disposed along the electrolytic nickel plating layer 6, and the stainless steel sheet 1 The brazing material 7 having a thickness of 0.05 mm is further arranged at the drawing port for evacuating the internal space formed by the above. That is, by disposing the brazing material 7, a gap is formed between the electrolytic nickel plating layer 6 and the brazing material 5, and the vacuum heat insulating material 10 is evacuated to be a vacuum port. The inside can be heated and the vacuum heat insulating material 10 can be joined efficiently and reliably.

FIG. 4 shows a pressing jig 8 that sandwiches the filler 3 between the stainless steel sheets 1 and presses the joining portion 2 (the end of the stainless steel sheet 1, the electrolytic nickel plating layer 6, the brazing material 5 and the brazing material 7) of the stainless steel sheet 1. , 8 are shown. FIG. 5 shows a state in which the pressing jigs 8 and 8 are pressed by the upper and lower stainless plates 9 and 9 and the stainless plates 9 and 9 are further tightened (pressurized state). At this time, the pressure applied to the joint portion 2 is preferably 10 to ²⁰ N / cm ² .

  As shown in FIG. 5, the joining portion 2 of the stainless steel sheet 1 is conveyed into the vacuum furnace while being pressed by the pressurizing jig 8 and the stainless steel plate 9 (pressurized state), and the inside of the vacuum furnace is 1 Pa or less. And then held at room temperature for about 90 minutes. Thereafter, the inside of the vacuum furnace was heated from room temperature to 590 ° C. over 240 minutes and held for about 60 minutes. Furthermore, the temperature was raised to 800 ° C. in about 20 minutes, held for 60 minutes, then cooled to 500 ° C., and then cooled to room temperature in a nitrogen atmosphere.

  The joint portion 2 of the vacuum heat insulating material 10 produced in this way is securely bonded without defective adhesion and does not impair the properties of the filling material 3 filled therein.

Sectional drawing which shows the structure of a vacuum heat insulating material. Explanatory drawing which shows the joining method of the stainless steel sheet edge part which is an exterior material. The brazing material arrangement | positioning figure to a stainless steel sheet edge part. Explanatory drawing which shows the manufacturing method of a vacuum heat insulating material (the 1). Explanatory drawing which shows the manufacturing method of a vacuum heat insulating material (the 2).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Stainless steel sheet 2 Stainless steel sheet junction part 3 Filler 4 Getter material 5 Brazing material 6 Electrolytic nickel plating layer 7 Brazing material 8 Pressurizing jig 9 Stainless steel plate 10 Vacuum heat insulating material

Claims (9)

  In a heat-insulating filler, an exterior material that covers and seals the filler, and a vacuum heat-insulating material in which the interior of the exterior material is a vacuum space, the exterior material is made of a metal sheet, and a joint portion of the exterior material is A vacuum heat insulating material characterized in that it is brazed and the joint portion of the exterior material is plated.   2. The filler is made of silica-based inorganic fibers, the exterior material is made of a stainless steel sheet having a thickness of 0.02 to 0.05 mm, and the plating process is an electrolytic nickel plating process. Vacuum insulation material.   The filler is made of a laminate in which a silica-based inorganic fiber sheet and a metal foil are laminated, the exterior material is made of a stainless steel sheet having a thickness of 0.02 to 0.05 mm, and the plating process is an electrolytic nickel plating process. The vacuum heat insulating material according to claim 1, wherein the vacuum heat insulating material is provided.   The vacuum heat insulating material according to any one of claims 1 to 3, wherein an additive mainly comprising a zirconium / aluminum alloy or a zirconia / vanadium alloy is added to the vacuum heat insulating material.   In a method for manufacturing a vacuum heat insulating material in which a filler having a heat insulating property is covered and sealed with an external material, and the inside of the external material is a vacuum space, the external material is made of a metal sheet, and a joint portion of the external material is A method for producing a vacuum heat insulating material, characterized by performing brazing after plating.   6. The filler is made of silica-based inorganic fibers, the exterior material is made of a stainless steel sheet having a thickness of 0.02 to 0.05 mm, and the plating process is an electrolytic nickel plating process. Of manufacturing vacuum insulation material.   The filler is a laminate obtained by laminating a silica-based inorganic fiber sheet and a metal foil, the exterior material is a stainless steel sheet having a thickness of 0.02 to 0.05 mm, and the plating process is an electrolytic nickel plating process. 6. The method for producing a vacuum heat insulating material according to claim 5, wherein:   6. The joint portion of the exterior material is conveyed into a vacuum furnace in a pressurized state, and the joint portion of the exterior material is joined at a temperature higher than the operating temperature condition in the vacuum furnace. 8. A method for producing a vacuum heat insulating material according to any one of 7 above.   The interior of the vacuum furnace is maintained at 1 Pa or less, the temperature in the vacuum furnace is set to 780 to 820 ° C, and the joint portion of the exterior material is joined. Manufacturing method of vacuum heat insulating material.

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