CN-116801973-B - Getter activation and use

Abstract

A method of removing a contaminant from an environment is described, the method comprising the steps of (i) heating a reduced and passivated getter material to a temperature in the range of (T T -X) to (T T +Y) to form an activated getter material having a surface active for contaminant removal, the getter material containing crystallites of a metal in elemental form encapsulated by a layer comprising a metal oxide, wherein T T is the Tasman temperature of the metal in elemental form in degrees Celsius, X is 400 and Y is 200, and (ii) exposing the activated getter material to an environment containing the contaminant.

Inventors

• A. Butland
• M. Carlson
• D. DAVIS
• J. Higgins
• A. E. Richardson
• E. Softeli
• J. WEBSTER

Assignees

• 庄信万丰股份有限公司

Dates

Publication Date

20260508

Application Date

20220303

Priority Date

20210317

Claims (11)

1. 1. A method for removing contaminants from an environment comprising the steps of (i) heating a reduced and passivated getter material to a temperature in the range of (T T -X) to (T T +Y) to form an activated getter material having a surface active for contaminant removal and a reduced metal surface area in the range of 5m 2 /g to 50m 2 /g, the reduced and passivated getter material containing crystallites of the metal selected from nickel, cobalt, iron or copper in elemental form encapsulated by a layer of metal-containing oxide dispersed on a support surface, wherein T T is the Tasmann temperature of the metal in elemental form in degrees Celsius, X is 400 and Y is 200, and (ii) exposing the activated getter material to an environment containing the contaminants, wherein the crystallites of the metal in elemental form of the layer of the metal-containing oxide are formed by precipitation of reducible metal compounds and support compounds or impregnation of reducible metal compounds from solution.
2. 2. The method of claim 1, wherein the heating step is performed on the reduced and passivated getter material before, during, or after the material is transferred to a container in which the material is to be used.
3. 3. The method of claim 2, further comprising the step of sealing the container under vacuum or inert gas to form a sealed container.
4. 4. The method of claim 1, wherein the metal in the reduced and passivated getter material comprises nickel.
5. 5. The method of claim 4, wherein the nickel content in the reduced and passivated getter material is in the range of 1 to 95 weight percent.
6. 6. The method of claim 1, wherein the reduced and passivated getter material has a degree of reduction in the range of 10% to 90%.
7. 7. The method of claim 1, wherein the heating step is performed under a vacuum of at least 98.7%.
8. 8. The method of claim 1, wherein the heating step is performed under an inert gas selected from the group consisting of nitrogen, helium, and argon.
9. 9. The method of claim 1, wherein the metal in the reduced and passivated getter material is nickel and the reduced and passivated getter material is heated to a temperature in the range of 190 ℃ to 790 ℃.
10. 10. The method of claim 1, wherein the contaminants are selected from one or more of hydrogen, carbon dioxide, water, oxygen, carbon monoxide, and hydrocarbons.
11. 11. The method of claim 1, wherein the contaminant is hydrogen.

Description

Getter activation and use The present invention relates to a method for activating a getter and to the use thereof for removing contaminants. Getters are sorbent compositions that can function by adsorption or absorption, typically used within a container to remove unwanted substances from the atmosphere within the container. The container may for example be a housing for an electrical or electronic device. Alternatively, the container may be used to maintain a vacuum, or be part of an insulating unit under vacuum, wherein a getter is used to maintain a vacuum. Getter compositions are known. For example, WO2015/015221 discloses a getter composition suitable for gettering hydrogen and moisture comprising an alkaline earth metal oxide or precursor thereof and a transition metal oxide or precursor thereof, wherein the transition metal is selected from copper, nickel and cobalt. One type of getter known as a non-evaporable getter (NEG) is mainly a porous alloy or powder mixture of Al, zr, ti, V and Fe. EP0719609 (A2) discloses a process for preparing non-evaporable getter materials by mixing a metallic getter element, one or more getter alloys and a solid organic compound, wherein all the components are in the form of a powder having a specific particle size. These alloys can be thermally activated to create metal surfaces that adsorb or absorb contaminant gases such as hydrogen, water, oxygen, and carbon oxides, thus acting as a means to maintain a high vacuum (e.g., in a vacuum package) or to maintain the primary purity of the gas. However, NEG alloys are limited by very low metal surface areas, for example as shown in EP0719609 (A2), where the surface area is less than 0.2m 2/g. While the prior art getter compositions are useful in many applications, there are limitations to them due to the inherently low surface area for gettering active metals. A method has been found that overcomes the limitations of the prior art methods and provides a significantly greater active gettering surface area. Accordingly, the present invention provides a method for removing contaminants from an environment comprising the steps of (i) heating a reduced and passivated getter material to a temperature in the range of (T T -X) to (T T +y) to form an activated getter material having a surface active for contaminant removal, the getter material containing crystallites of a metal in elemental form encapsulated by a layer comprising a metal oxide, wherein T T is the taeman temperature of the metal in elemental form in degrees celsius, X is 400 and Y is 200, and (ii) exposing the activated getter material to an environment comprising the contaminants. The taeman temperature is a known property of metals and is the temperature at which atoms or molecules of a solid acquire enough energy to become apparent in their bulk mobility and reactivity. The temperature is typically half the melting point, e.g., copper is 405 ℃, cobalt is 604 ℃, iron is 631 ℃ and nickel is 590 ℃. The heating step produces an activated getter material having a surface active for removing contaminants, such as contaminant gases, from the environment. The environment may be an inert gas such as nitrogen, helium or argon, or may be a vacuum or partial vacuum. The heating step may be performed on the reduced and passivated getter material before, during or after the material is transferred to the container in which the material is to be used. Thus, the method may comprise the step of mounting the reduced and passivated getter material or activated getter material in a container in which the material is to be used. In one arrangement, the container may be a flow-through container, i.e. a container through which an inert fluid (such as an inert gas) may pass. In another arrangement, the container is sealed, in which case the method may further comprise the step of sealing the container under vacuum or an inert gas to form a sealed container. The heating step to create the activated getter may be performed before, during or after the sealing step. The method may be adapted to reduced and passivated getter materials containing any metal capable of capturing or gettering contaminants. The metal may be present in the reduced and passivated getter material in an amount ranging from 1 to 95 wt% (expressed as metal). The method may be particularly suitable for getters containing metals selected from copper, cobalt, iron and nickel. Applicants have found that nickel-containing getters are particularly suitable for activation by the process of the present invention. The reduced and passivated nickel getter activated by the process of the invention may have a nickel content, expressed as Ni, in the range of 1 to 95 wt%, preferably 10 to 60 wt%, more preferably 30 to 60 wt%. The reduced and passivated getter material contains crystallites of a metal in elemental form encapsulated by a layer comprising a metal oxide. Unlike NEG materials, crystallites are dispersed on the surface o