JPS62158974A - Vacuum heat-insulating material for electrical apparatus - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a vacuum heat insulating material used for heat insulating walls of household refrigerators, etc.

<Prior art> A conventional vacuum insulation material using a bag-shaped outer cover 1 made of plastic laminate film as a container for maintaining a vacuum state is as follows:
In the outer cover 1 made of a single plastic film, the degree of vacuum inside the outer cover 1 decreases due to air, steam, etc. penetrating through the plastic film, and the heat insulation properties deteriorate. To prevent this, a plastic laminate film is used as the outer cover 1, which is a composite of plastic and metal foil, or plastic and metal vapor-deposited film, etc., and has enhanced gas barrier properties.

FIG. 5 is a cross-sectional view of a conventional vacuum heat insulating material, and FIGS. 6 and 7 are examples of enlarged cross-sectional views of a plastic laminate film in which a metal foil and a metal vapor-deposited film are combined with plastic, respectively.

In FIG. 5, 3 is a filler (insulating spacer) such as perlite or glass wool, and AI is the filler 3.
A2 is the front surface on the high temperature side among the crossing surfaces, and A2 is the rear surface on the low temperature side. Reference numeral 4 denotes a breathable inner bag for packaging the filler 3, and this has the function of preventing the filler 3 from scattering during vacuum packing. Bl and B2 are the outer cover 1
CI and C2 are the front and rear outer coverings of the flat part, Dl and B2 are the front and rear outer coverings of the same peripheral edge, and E is the heat seal during bag making. Department.

Figure 6 shows the cross-sectional form of the outer cover 1, in which 1.5 is a fused plastic film layer for heat sealing, 6 is an adhesive layer, 7 is a metal foil layer, and 8 is a protective plastic film. It is a layer.

In the case of the outer cover 1 made of a plastic laminate film using the metal foil layer 7, the metal foil layer 7 needs to have a thickness of about 20 micrometers or more in order to obtain sufficient gas barrier properties.

By the way, since the thermal conductivity of metal is very high, the surface heat conduction of the metal foil layer 7 causes the outer covering material C1,
A thermal bridge is formed near C2, and the outer covering material B1 on the front surface of the flat part of the outer covering body 1 → the same, the outer covering material C1 on the front surface of the connecting part → the same, the outer covering material D1 on the front surface of the peripheral part → the same, heat Seal part E → same, outer covering material D2 on the rear surface of the peripheral edge → outer covering material C on the rear face of the connecting part
2->Same, there is a drawback that heat is conducted to the outer sheathing material B2 on the rear surface of the flat part, and the heat insulation properties of the vacuum heat insulating material 2 deteriorate.

Moreover, FIG. 7 shows the cross-sectional form of the conventional outer cover 1.
9 is a fused plastic film layer, 6 is an adhesive layer, 10
11 is a plastic film layer for a vapor deposition base material, and 11 is a metal vapor deposition film layer applied to the plastic film layer 10 for a vapor deposition base material.

In this case, since the metal vapor-deposited film layer 11 has a thickness of only about 500 angstroms, there is almost no surface heat conduction of the metal, but the gas barrier properties are quite good compared to the outer cover 1 made of a single plastic film. Compared to the outer cover 1 using layer 7, it is still not sufficient, and air and water vapor gradually penetrate into the vacuum insulation material 2, the degree of vacuum inside the outer cover 1 decreases, and the insulation properties gradually deteriorate. However, it still has the disadvantage that its lifespan as an insulating material is limited.

When an outer cover including the metal foil layer 7 over the entire outer cover material is used to impart sufficient gas barrier properties to the outer cover 1 made of a laminate film, heat conduction as described in -1- occurs.

However, if we take a closer look at the outer cover 1 that covers each part of the filler 3, we find that heat conduction occurs in areas where there is a temperature difference within the outer cover 1 itself, that is, along the thickness direction of the filler 3 where there is a temperature gradient. This is the part where This mainly occurs in the outer covering materials C1 and C2 at the connecting part of the outer covering 1, and in other parts perpendicular to the thickness direction of the heat insulating material, that is, the outer covering materials B1 and B2 on the front and rear surfaces of the same plane part. , the outer covering material D1. on the front and rear surfaces of the same peripheral portion. D
2. Since there is almost no temperature difference inside the vacuum filling material 3 in the heat-sealed portion E, the outer cover 1 itself does not form a thermal bridge. By physically connecting these to each other, a thermal bridge is formed as a whole of the outer cover 1, and if the outer cover materials C1 and C2 of the connecting parts do not exist, a metal foil layer is formed in other parts. Even if 7 exists, it cannot be a thermal bridge.

However, it is also possible to think that a thermal bridge will not be formed if the physical contact between the metal foil layers 7 near the outer sheathing materials C1 and C2 of the connecting parts is cut off, and according to this idea, the metal foil layer 7 can only be formed in the heat-sealed part E. It seems that it is sufficient to remove the following, but according to this, the outer covering material B1 of the flat part of the outer covering 1 → the outer covering material C of the same spanning part
1 → Same, outer covering material D1 of the peripheral edge → Same, outer covering material D2 of the peripheral edge
→ In the same way, since heat is conducted to each part in the order of outer covering material C2 of the connecting part → outer covering material B2 of the same plane part, outer covering material C of the connecting part
1 → Crossing surface A1 of filler 3 → Same, A2 → Outer covering material C2 of the extending part of outer covering 1 or outer covering material D1 of the same peripheral part →
Similarly, heat is transferred in the order of the outer sheathing material D2, and heat conduction due to contact between various parts remains, so even if there is no direct thermal bridge due to surface heat conduction of the metal foil layer 7, there is an indirect thermal bridge (made of materials other than metal). heat conduction), which inevitably has an adverse effect on the heat insulation properties, which is undesirable.

Alternatively, all metal foil layers 7 that can become thermal bridges
may be removed, but since only the flat outer covering materials Bl and B2 are covered with the metal foil layer 7, which has excellent gas barrier properties, gas and water vapor that permeate and enter from other parts are prevented. Therefore, the insulation properties deteriorate over time.

<Objective> The present invention aims to provide a vacuum heat insulating material whose heat insulating properties are less deteriorated over time.

<Example> Hereinafter, an example of the present invention will be described based on FIGS. 1 to 4. This will be explained based on FIG. 1 to FIG. 4. ] are formed substantially parallel to each other, and an outer cover 1 is provided for covering the heat insulating filler 3 and maintaining the inside of the heat insulating filler 3 in a vacuum state, and the outer cover 1 is formed substantially parallel to the high temperature side surface. 3a and cold side 3
1) High temperature side outer covering material B1 and low temperature side outer covering material B
2, and the peripheral edge spanning surface A1 of the high temperature side surface 3a and the low temperature side surface 31]. The outer covering material Ail covering A2, A1
2, the high-temperature side outer covering material B1 and the low-temperature side outer covering material B2 are composed of a film X including a metal foil layer 7 for maintaining a vacuum state, and the above-mentioned span outer covering materials A11 and Al1 are formed from a vacuum state. It is composed of a coating Y including a vapor deposited layer 11 for maintaining the condition.

The vacuum heat insulating material main body 2 includes the heat insulating filler 3, the outer cover 1, and an inner bag 4 interposed between the outer cover 1 and the heat insulating filler 3.

The heat insulating filler 3 is formed to have an external cross-sectional shape as shown in FIG. That is, the ends of the heat insulating filler 3 are squeezed into a triangular shape to form the connecting surfaces AI and A2.

The outer cover 1 is made into a bag shape by heat-sealing the peripheral edges of two sheet materials, and as shown in the prior art, the high temperature side and low temperature side outer cover materials B1. B2 and the delivery surface A
I, A12, and a spanning part outer covering material All, which covers A2,
The outer sheathing material D1°D2 of the peripheral edge portion, and the outer sheathing material D1.D2 of the peripheral edge portion.
It consists of heat seal outer covering materials El and E2 which are connected to D2. E is a heat seal part.

3 and 4 show an example of the laminate structure of the outer covering 1 made of a laminate film of the vacuum heat insulating material 2 according to the present invention, and FIG. 3 shows an example of the outer covering material A11. A12
FIG. 4 is an enlarged sectional view of each outer covering material of other parts. In the figure, 9 is a fusion plastic film layer, 6 is an adhesive layer, 10 is a plastic film layer for a vapor deposition base material, 11 is a metal vapor deposition film layer, 8 is a protective plastic film layer, and 7 is a metal foil layer. In the figure, the fused plastic film layer 9 is on the inside (the side of the heat insulating filler 3).

Next, to explain the function, heat conduction from the high temperature side to the low temperature side of the outer cover 1 is as described in the prior art, but the films forming the outer cover materials Ajl and AI2 of the connecting part are metal vapor-deposited. It includes a film layer 11, which can prevent heat conduction to the cold side outer covering material. By the way, there are various methods for removing the metal foil layer from the outer sheathing material A11°A12. For example, when laminating the film, after laminating the metal foil layer 7 on the protective plastic film layer 8, the outer sheathing material can be removed. There is a method of applying resist ink to areas other than the All and A12 parts, removing the metal foil layer 7 by etching, and then laminating the remaining film.

Further, after laminating the fusion bonded plastic film layer 9, the metal vapor deposition film layer 11, and the plastic film layer 10 for the vapor deposition substrate, a release ink is applied to the plastic film layer 10 for the vapor deposition substrate, and the metal foil is coated with release ink. Laminate the layer 7 and apply the outer covering material A1.1. A12 may be mechanically peeled off.

Furthermore, it is also possible to separately laminate the outer covering materials El and E2 of the high-temperature side and low-temperature side heat-sealing portions of the outer covering 1 and the metal foil layers 7 of the outer covering materials Di and D2 on the front and rear peripheral edges. Needless to say.

It should be noted that the present invention is not limited to the above embodiments, and it goes without saying that many modifications and changes can be made to the above embodiments within the scope of the present invention.

For example, when the cross section of the heat insulating filler is rectangular, a film containing a vacuum-maintaining vapor deposited layer may be used only for the outer covering material at the left and right ends.

<Effects> As is clear from the above description, the present invention provides a method in which the high-temperature side surface and the low-temperature side surface of the heat-insulating filler, which determine the shape of the vacuum heat-insulating material body, are formed substantially parallel to each other, and the heat-insulating filler is covered with the heat-insulating filler. An outer covering is provided to maintain a vacuum state inside the heat insulating filling material, and the outer covering includes a high temperature side outer covering material and a low temperature side outer covering material that cover the high temperature side surface and the low temperature side surface, and a high temperature side outer covering material and a low temperature side outer covering material that cover the high temperature side surface and the low temperature side surface. and a spanning outer sheathing material that covers the peripheral spanning surface of the low-temperature side surface, and the high-temperature side outer covering material and the low-temperature side outer covering material are composed of a coating including a metal foil layer for maintaining a vacuum state, The present invention relates to a vacuum heat insulating material for electrical equipment, characterized in that the spanning outer covering material is composed of a film including a vapor-deposited layer for maintaining a vacuum state.

Therefore, according to the present invention, with a simple structure in which a coating containing a vacuum-deposited layer for maintaining a vacuum state is used only in the part of the outer jacket where a temperature difference occurs, it is possible to sufficiently prevent heat conduction, thereby achieving insulation. This has the excellent effect of being able to provide a vacuum heat insulating material with less deterioration of properties over time.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view of the vacuum insulation material of the present invention, Fig. 2 is a plan view thereof, Fig. 3 is an enlarged sectional view of the outer covering material, and Fig. 4 is a cross-sectional view of the outer covering material. 5 is a cross-sectional view of a conventional vacuum insulation material, FIG. 6 is an enlarged sectional view showing an example of the outer covering material, and FIG. 7 is another example of =11. = It is an enlarged sectional view showing. AI, A2: Crossing surface, All, A12: Crossing part outer cover material, 1: Outer cover, 2: Vacuum insulation material, 3: Heat insulation filler, 3
a: high temperature side surface, 3b: low temperature side surface, 7: metal foil layer for maintaining vacuum state, 11: metal vapor deposited film layer for maintaining vacuum state, B1: high temperature side outer covering material, B2: low temperature side outer covering material.

Claims (1)

[Claims] A high-temperature side surface and a low-temperature side surface of a heat-insulating filler that determine the shape of the vacuum heat-insulating material body are formed substantially parallel to each other, and an outer covering covers the heat-insulating filler and maintains the inside of the heat-insulating filler in a vacuum state. The outer covering includes a high-temperature side outer covering material and a low-temperature side outer covering material that cover the high-temperature side surface and the low-temperature side surface, and a spanning outer covering material that covers the peripheral edges of the high-temperature side surface and the low-temperature side surface. The high-temperature side outer covering material and the low-temperature side outer covering material are composed of a film including a metal foil layer for maintaining a vacuum state, and the spanning outer covering material includes a vapor-deposited layer for maintaining a vacuum state. A vacuum insulation material for electrical equipment, characterized in that it is composed of a film containing: