JPS61115840A - Refractory housing vessel for photographic film and magnetictape and the like - 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 The present invention relates to a fire-resistant container for storing photographic film, magnetic tape, etc.

Current general-purpose photographic films and magnetic tapes are mainly based on thin thermoplastic sheets, which inherently have poor heat resistance, and in the event of a fire, they can be replaced by conventional flammable sheets. Of course, those using
Even if it is based on a flame-retardant sheet, it will inevitably be severely damaged and become unusable.

Furthermore, even if these are stored in a normal fireproof safe, unlike paper documents, they are subject to severe deterioration due to heating and temperature rise in the event of a fire, and it is extremely difficult to maintain their usable condition, including the paint film.

This invention can withstand fire well and prevent its damage.
This product provides a storage container for photographic films and magnetic tapes, and its basic structure consists of two layers of stainless steel plates, the middle part of which is sealed under near-vacuum pressure, forming the inner and outer peripheral walls of a so-called Maho bottle. A layer of mainly inorganic heat insulating material that can withstand high temperatures is installed along the inside, and photographic film, magnetic tape, etc. can be inserted and stored in the internal space. The opening on one side of this storage container for loading and unloading shall be provided with a removable lid as in the case of the Maho jar, and a sufficient thickness of insulation layer similar to the above shall be installed inside and outside of the lid. .

Stainless steel with chromium and nickel content of 1 each
As is well known, metals with an austenite structure of 8.8 or higher have extremely low thermal conductivity among metals, so they are used as mirror-finished glass, which is the main material of traditional Maho bottle bodies. What was replaced with is the heat retention,
Although there is a slight decrease in the cooling effect, it is still sufficient for practical use, and on the other hand, it has much superior mechanical strength compared to conventional products, so it has rapidly become popular as it has been introduced to the market in recent years. It is becoming widely used.

This invention consists of a composite body that has a container of the same type as this stainless steel Maho bottle as its main component, and a layer of mainly inorganic heat-resistant heat insulating material installed as a sub-component on the inner and outer peripheral walls of the container. When this material is heated, firstly, the heat transfer to the inside is considerably reduced by the outer circumferential insulation layer, and then the low thermal conductivity of the stainless steel itself and the vacuum between its double walls reduce the heat transfer to the inside. Combined with its excellent thermal insulating effect, which functions as a Maho bottle (blocking radiation and convection), the rise in temperature of its inner wall is significantly suppressed.

Therefore, a layer of insulation material was installed along the inner wall,
In addition, if an appropriate and sufficient layer of insulation is installed around the lid of the opening on the edge of the Maho bottle, their effect will reduce the average thickness of the container in the event of a fire. Within the range of continuous heating time, the internal space is
It exhibits excellent performance that cannot be expected from conventional fireproof safes, as it does not raise the temperature to the point where it burns out the stored items, which are mainly made of thermoplastic synthetic polymers.

Regarding the above-mentioned sub-component, the inorganic heat-resistant heat insulating material layer, in order to achieve its purpose, it must first be used on the outer periphery of the main Maho bottle at a temperature of 1, which is the maximum temperature in the event of a fire.
,000 to 1,200 degrees Celsius is required, and conventional products such as fireproof and insulating bricks used to cover the inner walls of high-temperature heating furnaces are suitable for this purpose, but here Recent ceramic fibers, which are made by melting materials mainly made of high-purity alumina and silica and turning them into fibers using centrifugal force, are lightweight and have excellent heat insulation properties, especially at high temperatures of 1,200 to 1,400 degrees Celsius. It can be used as the most suitable material for this purpose because it has good resistance to water. (Although asbestos can also be used, it is undesirable for health reasons and should be avoided as much as possible.) Specifically, we used this ceramic fiber in its cotton form.
Alternatively, it can be attached by an appropriate method, such as wrapping a felt-shaped material around the outer periphery of the Maho bottle, or covering it with a sleeve-shaped material. In order to mechanically protect this heat insulating material layer, it is also preferable to cover it with a metal plate or the like. The thickness of the insulation layer attached to the outer periphery is determined by taking into consideration its density and the duration of high temperature during a fire.
Usually, a practically sufficient effect can be expected within a range of several cm.

Next, the heat insulating material used for the inner wall of the Maho bottle is different from the outer wall, which is exposed to high-temperature flames either directly or through a simple protective coating, because of the excellent thermal insulation effect of the Maho bottle mentioned above. Therefore, properties that can withstand such high temperatures are not required, so in addition to the above-mentioned insulation materials suitable for external walls, foam glass, glass wool, rock wool, etc. can also be used, depending on the conditions. In addition, in combination with these inorganic materials, some relatively heat-resistant organic insulation materials, such as polyisocyanurate foam, can also be used supplementarily in the innermost part, and in that case, due to their characteristics, It is also possible to reduce the total thickness of this inner wall insulation material layer to some extent.

Examples of the present invention are shown below: (1). 18-8 stainless steel plate with a thickness of 0.6 mm,
Inner diameter 200mm, outer diameter 230mm, length 350mm,
It is molded into a Maho bottle-shaped container with double walls and a dome-shaped bottom at one end and an open end, and the space between the double walls is evacuated to 5 mm or less of mercury. On the outer wall of this container, short fibers of the aforementioned ceramic fiber with an average fiber diameter of 3.5 microns that can withstand 1.260°C are placed at a density of 16
0kg/m3, 10mm thick felt-shaped sheets are wrapped or laminated 3 to 4 times, and the outside is made of a 0.4mm thick single layer steel plate with a diameter of 300mm and a length of 40mm.
Cover and exterior with a cylinder with a 0 mm bottom. On the other hand, on the inner wall,
Glass wool with an average diameter of 8 microns and a density of 100 kg/
m3, molded into a sleeve with an outer diameter of 200 mm and a thickness of 25 mm, is inserted along the inner wall of the cylinder,
A matching glass wool molding of the same quality, density, and thickness is installed at the bottom of the cylindrical edge, and the thickness is adjusted to protect their surfaces (sleeve and inner surface of the bottom) from contact with stored items. The interior is coated with a 100 micron polycarbonate film.

The opening at the other end of the cylindrical container is fitted with a matching disc-shaped double lid made of stainless steel plate, with a 1-inch thick lid on the outside.
00mm mats made of the same ceramic fiber as above, and on the inside, in order, a 30mm thick mat made of ceramic fiber as above and a 30mm thick mat made of glass wool as above were placed one on top of the other. On the surface, an exterior made of steel plate and an interior made of polycarbonate film are provided, similar to the main container.

(2). The lid part in Example (1) is omitted, and two cylindrical main containers including a heat insulating material layer and an interior and exterior are joined in a removable manner with their openings facing each other, and the outside of the joint is The above-mentioned ceramic fiber mat having a thickness of 50 mm is additionally wound in a band shape of 100 mm in width along the surface of the mat, and the outer covering made of a steel plate is applied to the surface of the mat in the same manner as above.

Both of the above containers contained photographic film and magnetic tape (the latter contained in a cassette case) in their respective internal spaces, and were tested in a simulated fire test to reproduce the conditions of flashover during a fire. When exposed, no damage to the contents was observed in either case, and the results showed that there was no problem at all in terms of their respective functions as photographic film and magnetic tape. Furthermore, this container is
Due to its performance, it is used as a storage container for thermoplastic films and tapes, but it can also be used to store paper documents and banknotes that are slightly more heat resistant than these materials. Needless to say, the above effects can be expected.

As described above, the present invention combines a Maho bottle-shaped container made of stainless steel plate as a main component and a heat-resistant heat insulating material layer as a sub-component, and utilizes the synergistic effect thereof. To provide a fireproof storage container which has a small and simple form and has better performance than a full-scale large fireproof safe. that's all

Claims (1)

[Claims] A Maho bottle-shaped container is made of double layers of stainless steel plates spaced apart, the middle part of which is reduced to near vacuum and sealed, and a layer of mainly inorganic heat-insulating material that can withstand high temperatures is installed on the inner and outer peripheries of the container and the inner and outer surfaces of its lid. A fire-resistant storage container for photographic film, magnetic tape, etc., whose internal space is used as a storage area.