JP3439629B2 - Low temperature active getter and method for producing the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a low temperature active getter used for holding a vacuum double structure made of metal such as a thermos under vacuum and a method for producing the same.

[0002]

2. Description of the Related Art In a vacuum double structure made of metal such as a thermos, an exhaust hole is formed at an appropriate position of the double structure and a getter is arranged in the exhaust space to heat the double structure. Meanwhile, after the air and gas in the exhaust space are exhausted from the exhaust hole, the getter is activated and the exhaust hole is sealed. The gas released into the exhaust space after the exhaust hole is sealed is absorbed by the activated getter, so that the exhaust space is maintained in a vacuum state.

The getter may be a high temperature active getter such as Ti-Al, Zr-Al, or Ti which is activated at a high temperature of 700 ° C. or higher, and Fe-V which is activated at a relatively low temperature of 100 to 500 ° C. -There are low temperature active getters such as Zr alloys. There are various materials for the high temperature active getter, they are present in large amounts as metals, and they are available at low cost.
However, the high temperature active getter has problems such as heat resistance of the exhaust device, heat resistance of the double structure itself, and sensitization when the double structure is austenitic stainless steel. Therefore, as the getter used for the vacuum double structure, the low temperature activated getter is preferable to the high temperature activated getter, though it is expensive. Therefore, an inexpensive low-temperature active getter has been conventionally demanded.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide such an inexpensive low temperature active getter and a manufacturing method thereof.

[0005]

Since the surface of the getter material is covered with oxides, nitrides, etc. in the atmosphere, the getter action does not occur at room temperature. However, when the getter material is heated, the surface oxide, Nitride decomposes and oxygen atoms, nitrogen atoms, etc. diffuse inside the getter material, exposing a pure surface on the surface.As a result, gas molecules in a vacuum can be taken into the surface and the getter action is exerted. It is known to be done.

The present invention has been made based on such findings. That is, the low temperature activated getter according to the present invention is formed by forming a thin film of the low temperature activated getter material on the surface of the activated high temperature activated getter material.

The low temperature activated getter of the present invention having the above structure is activated by heating the low temperature activated getter material on the surface at the activation temperature of the low temperature activated getter material.
Gas molecules in vacuum can be incorporated on the surface. At this time, since the internal high temperature activated getter material has already been activated, the gas molecules taken into the surface low temperature activated getter material are further diffused to the internal high temperature activated getter. Since the low temperature activated getter material of the present invention has a thin film of the low temperature activated getter material formed on the surface of the inexpensive high temperature activated getter material, the cost is low as a result.

In the method for producing a low temperature activated getter according to the present invention, the high temperature activated getter material is activated in a vacuum atmosphere, and the low temperature activated material is deposited on the surface of the high temperature activated getter material in the vacuum atmosphere. To do. In the step of activating the high temperature activated getter material, the temperature of the high temperature activated getter material is raised to about 700 ° C. or higher, or the surface of the high temperature activated getter material is treated with an inert gas,
For example, the step of cleaning can be performed by sputtering with argon gas.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1A shows a low temperature active getter 1 according to the present invention. This low temperature active getter 1 is a pill,
The high temperature activated getter material 2 and the low temperature activated getter material 3 formed on the surface of the high temperature activated getter material 2. The high temperature activated getter material 2 is, for example, Ti, Ti—Al alloy, or Z that is activated at a high temperature (700 ° C. or higher).
It is made of r-Al or the like and has been previously activated at 700 ° C. or higher. The low temperature activated getter 3 has a low temperature (100-5
The getter material 2 is vapor-deposited on the outer surface of the high temperature activated getter material 2. The outer surface of the low temperature activated getter material 3 is covered with oxide, nitride or the like. The oxide, nitride, etc. may be added intentionally in the getter manufacturing process, or may be added naturally by exposing to the atmosphere immediately before attaching the getter to the vacuum equipment. The outer surface of the high temperature activated getter material 2, that is, the interface between the high temperature activated getter material 2 and the low temperature activated getter material 3 remains pure because the high temperature activated getter material 2 is activated. Has become.

The getter action of the low temperature active getter 1 having the above structure will be described below.
As shown in FIG. 1A, since the outer surface is covered with an oxide or a nitride in a room temperature atmosphere, it does not have a getter action. Next, this low-temperature activated getter 1 is placed in a space to be evacuated, such as the space between the inner bottle and the outer bottle of a thermos bottle, the space is evacuated to a vacuum, and the low-temperature activated getter material 3 is activated. When heated at the activation temperature (250 to 500 ° C.), as shown in FIG.
Oxides, nitrides, etc. on the outer surface of the are separated, and oxygen atoms, nitrogen atoms, etc. diffuse inside. As a result, the outer surface of the low temperature activated getter material 3 becomes pure, and gas molecules such as O, N and CH in a vacuum atmosphere are deposited on the surface of the low temperature activated getter material 3 as shown in FIG. 1 (C). The getter action occurs when hydrogen is taken in and hydrogen in the vacuum atmosphere diffuses inside. Since the high temperature activated getter material 2 inside has already been activated and its surface remains pure, the hydrogen diffused inside the low temperature activated getter material 3 is further absorbed inside the high temperature activated getter material 2. Spread to. Thereby, a sufficient getter action is exhibited.

FIG. 2 shows the manufacturing process of the low temperature active getter of the present invention. First, the high temperature active getter material 2 shown in FIG. 2A is prepared, and this high temperature active getter material 2 is heated in vacuum to its activation temperature, for example, 700 ° C. Alternatively,
The high temperature activated getter material 2 is sputtered with argon gas. By such heating or sputtering, as shown in FIG. 2B, oxides, nitrides, etc. on the outer surface of the high temperature active getter material 2 are separated and oxygen atoms and nitrogen atoms are diffused inside and activated. It becomes a state. Next, FIG.
As shown in (C), the low temperature activated getter material 3 is attached to the outer surface of the activated high temperature activated getter material 2 by a vacuum deposition method. Next, when this is exposed to the atmosphere,
As shown in FIG. 2D, oxides, nitrides and the like are attached to the outer surface of the low temperature activated getter material 3, and
Is manufactured.

FIG. 3 shows an apparatus for producing the low temperature active getter of the present invention. This apparatus has a closed container 12 capable of maintaining a vacuum state by a vacuum exhaust pump 11. Below the inside of the container 12, a high temperature activated getter material having a width of 5 to 10 mm and a thickness of 0.1 to 2 mm.
Supply roller 14 around which the ribbon-shaped titanium foil 13 of is wound.
And a take-up roller 15 for taking up the titanium foil 13 rewound from the supply roller 14 are arranged at a fixed interval so as to be rotationally driven. Also, the supply roller 1
A heater 16 for heating the titanium foil 13 moving from the supply roller 14 toward the take-up roller 15 is arranged between the winding roller 15 and the take-up roller 15. Further, below the inside of the container 12, an Fe metal block 17, a V metal block 18, and a Zr metal block 19, which are metal materials constituting the low temperature activated getter material, are arranged, and these metal blocks are respectively Heaters 20, 21 and 22 for heating are arranged.

A method of manufacturing a low temperature active getter of the present invention using this apparatus will be described. First, the vacuum exhaust pump 11 is driven to maintain the inside of the container 12 at a vacuum of 1 × 10 ⁻³ Torr or less, and then the heater. F by 20, 21, 22
The metal ingot 17, the V metal ingot 18, and the Zr metal ingot 19 are heated at 250 to 500 ° C., respectively. Next, the supply roller 14
Is rotationally driven in the direction of the arrow to feed out the titanium foil 13 and the titanium foil 13 is wound up by the winding roller 15.
The titanium foil 13 fed from the supply roller 14 is heated by the heater 16 at 700 ° C. or higher to activate the titanium foil 13. The activated titanium foil 13 is cooled as it moves away from the heating area, and Fe, V, and Zr are formed on its surface.
Is vapor-deposited, and a thin film of a low-temperature activated getter made of an Fe-V-Zr alloy is formed and wound on the winding roller 15. Thus, the titanium foil 13 activated at high temperature
The ribbon having a thin film of Fe-V-Zr alloy formed on the outer surface thereof can be used as a low temperature active getter.

Although the ribbon-shaped titanium foil 13 is used as the high temperature activated getter material in the above apparatus, a wire material or a plate material may be used. Further, in the above device, the titanium foil 13
Was activated by heating, but it can also be activated by cleaning by sputtering argon gas. Furthermore, the heating region of the titanium foil 13 by the heater 16 shown by the broken line in FIG. 3 is covered with a heat insulating wall,
It is also possible to prevent the escape of heat and prevent the vapor deposition of Fe, V, and Zr.

[0016]

As is clear from the above description, the low temperature activated getter of the present invention is inexpensive because a thin film of the low temperature activated getter material is formed on the surface of the inexpensive high temperature activated getter material. It can be widely used as a getter material that can be activated at low temperature in the production of various vacuum double containers.

[Brief description of drawings]

FIG. 1 is a sectional view showing the internal structure of a low temperature active getter according to the present invention and its getter action.

FIG. 2 is a diagram showing a manufacturing process of a low temperature active getter according to the present invention.

FIG. 3 is a view showing an apparatus for manufacturing a low temperature active getter according to the present invention.

[Explanation of symbols]

1 ... Low temperature activated getter, 2 ... High temperature activated getter material, 3
… Low temperature activated getter material.

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-56-165243 (JP, A) SAIKAI 51-62762 (JP, U) JP-B 61-33613 (JP, B2) SAKURA 43- 2086 (JP, Y1) Tokuyo HEI 8-512435 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) A47J 41/02 102 C23C 14/02 H01J 7/18

Claims (5)

(57) [Claims] 1. A low temperature activated getter, comprising a thin film of a low temperature activated getter material formed on the surface of an activated high temperature activated getter material. 2. A low-temperature activated getter characterized by activating a high-temperature activated getter material in a vacuum atmosphere and depositing a low-temperature activated material on the surface of the high-temperature activated getter material in the vacuum atmosphere. Method. 3. The method for producing a low temperature activated getter according to claim 2, wherein the step of activating the high temperature activated getter material comprises raising the temperature of the high temperature activated getter material to about 700 ° C. or higher. . 4. The low temperature activated getter according to claim 2, wherein in the step of activating the high temperature activated getter material, the surface of the high temperature activated getter material is cleaned by sputtering with an inert gas. Production method. 5. The method for manufacturing a low temperature active getter according to claim 4, wherein the sputtering with the inert gas is sputtering with an argon gas.