JPS5948917B2 - Laminated insulation material for cryogenic temperatures - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in conventional cryogenic laminated insulation materials.

Conventional laminated insulation materials are made by knitting a plastic film such as polyester with a thickness of about 6 to 25 μm, a reflective film with metal such as aluminum vapor-deposited on one or both sides, and plastic fibers such as polyester with a mesh size of about 20 mesh about 200 μm thick. A material made of alternating layers of spacers is used for extremely low temperatures.

This is effectively applied in multiple layers in the narrow gap between the inner and outer containers of cold storage containers. However, recently there has been a desire to further reduce the thermal conductivity and facilitate evacuation by increasing the gap between the inner and outer containers. The present invention addresses these needs. That is, the present invention (1) creates a vacuum between an inner container for storing cryogenic materials and an outer container surrounding it, and installs a spacer and a plastic film on one or both sides of which a metal such as aluminum is vapor-deposited. A laminated insulation material for cryogenic temperatures, which is used alternately or by laminating only the plastic films, and is embossed on one or both sides of the films to reduce the contact area between the films or between them and the spacer. (2) In the above insulation material, one or both sides of a plastic film with a metal such as aluminum vapor-deposited on one side are embossed, and a gap is provided between the film or the spacer. The content is a laminated heat insulating material for cryogenic temperatures, which is made by laminating films so that the metal-deposited side and the non-metal-deposited side are in contact with each other.

The present invention and its effects will be explained below in comparison with conventional heat insulating materials.

That is, in the conventional laminated insulation material method, the spacer is made into a net shape to reduce the contact area between the reflective film and the spacer, but in the present invention, the contact area between the reflective film and the spacer is further reduced by embossing the reflective film. This reduces the contact area and direct thermal conductivity.

Furthermore, in the past, the gap between the reflective films was narrow and consisted only of the gap created by the spacer net, so it tended to be difficult to draw a vacuum due to gas resistance. In the present invention, by embossing, the gap between the spacer and the reflective film, as well as the gap between the reflective films, becomes larger, making it easier to draw a vacuum between the layers, thereby easily solving the problem. In addition, there is a simple laminated insulation material for extremely low temperatures in which only a metal-deposited plastic film is laminated by using the plastic part of the reflective film body as a spacer, although its insulation performance is considerably inferior.
Since the layers are in full contact with each other, there is a drawback that direct heat conduction is large.

In the present invention, this drawback has been solved by using a plastic film which has been vapor-deposited with aluminum or the like on one side and has been given an enamel boss.

That is, by stacking these films so that the vapor-deposited surface and the non-vapor-deposited surface are adjacent to each other, and by shifting the embossed patterns of the adjacent films from each other, or by using different patterns for each,
Hui! To reduce the contact area between rems and create a connected space between films. As described above, a vacuum layer was easily formed between the five film layers, and the contact area between the film layers was small, making it possible to significantly improve the heat insulation performance. (1) above,
Common to (2), materials used as low-temperature insulation materials are heat resistant, cold resistant, low water absorption, and easy to handle. Polyester is preferably used, and for embossing, a polyester film with a thickness of about 25 μm, which is not too stiff and not too thick, is desirable.

An example of the present invention will be described below with reference to the drawings.

FIG. 1 relates to the above (1) of the present invention in which films and spacers are alternately laminated, and A in FIG.

FIG. 1 is a perspective view of the laminated heat insulating material of the present invention. Also, Al in Figure 1,
A2 and A3 are examples of embossed heat insulating films viewed diagonally from above, and are a perspective view and a sectional view, respectively.
A1 is an example in which a circular hill-shaped embossment with a diameter of 5 mm and a height of about 1 mm is placed on the top surface, and the distance between the circular centers is 10 mm.The contact area with the spacer in the above example can be significantly reduced, and the gap between the layers is large. Become.

A2 is an example in which the circular embossing of A1 is performed alternately upward and downward, and the contact area between the reflective film and the upper and lower spacers is further 1/2 of the smaller one in A1.
Therefore, the voids in the reflective film are approximately twice that of A1, making it even more effective than A1.

A3 is an example in which a waveform is embossed on both sides of the reflective film, the waveform is bent in a zigzag manner, and small hills are embossed at the bending points on the mountain side and the valley side. FIG. 2 shows a structure in which only the films described in (2) of the present invention are laminated, and B in FIG.

is a perspective view of a laminated insulation material. Bl, B2, B3 in Figure 2
, B4 are perspective views of the heat insulating materials of the present invention viewed diagonally from above, and each is a polyester film with corrugated embossing on both sides and aluminum vapor-deposited on the upper surface.

Only B3 has a zigzag waveform. and each point is Bl, B2
, B3, the corresponding points are Bl, B2
, B3, it looks like the perspective view of B4.

The contact points of each adjacent layer are only the intersection of the valley of the waveform in the upper example and the peak of the lower waveform, and the contact area of each layer becomes small, and a gap is created between each layer, and a connected space is created. satisfies the conditions of

[Brief explanation of the drawing]

Figure 1 shows an example of the heat insulating material of the present invention. Figure 1 is a perspective view of the laminated heat insulating material of the present invention, and Al, A2, and A3 are examples of the heat insulating material with embossments seen diagonally from above. They are a perspective view and a sectional view, respectively. FIG. 2 also shows an example of the heat insulating material of the present invention, and B in FIG. are perspective views of the laminated heat insulating material of the present invention, Bl and B2 in FIG.
, B3 are perspective views of the heat insulating material of the present invention, B4 are Bl, B2
, B3 are stacked together. 1 is an embossed reflective film, 2 is a net spacer, 3 is an aluminum vapor-deposited corrugated embossed polyester film on the upper surface, and 4 is the same upper aluminum vapor-deposited corrugated embossed film as in 3, but the position is shifted at right angles from the directional position of the vertically adjacent embossed corrugations. Laminated.

Claims (1)

[Claims] 1. A vacuum is created between an inner container for storing cryogenic materials and an outer container surrounding it, and a spacer and a plastic film on one or both sides of which a metal such as aluminum is vapor-deposited are placed in the space. A laminated heat insulating material for cryogenic temperatures that is used in alternating layers or is made by laminating only the plastic films, and is embossed on one or both sides of the films to reduce the contact area between the films or between them and the spacer. A laminated heat insulating material for cryogenic temperatures that is made small and has a gap between it and the film or spacer. 2. The cryogenic material according to claim 1, which is obtained by embossing one or both sides of a plastic film on which a metal such as aluminum is vapor-deposited, and laminating the film so that the metal-vapor-deposited surface and the non-vapor-deposited surface are in contact with each other. Laminated insulation material.