Composite getter material, getter paste

Abstract

To provide a composite getter material that reduces the chances of gases remaining in the vacuum space.SOLUTION: A composite getter material contains at least particles composed of zeolite and particles composed of a cerium compound. The content of the cerium compound is 50 mass% or less with respect to the mass of the composite getter material. The particles composed of the cerium compound have an average particle diameter of 10 nm or more and 30 μm or less.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This disclosure relates to composite getter materials and getter pastes. [Background technology]

[0002] Patent Document 1 discloses a method for manufacturing a glass panel unit. In this method, a glass composite comprising a first substrate, a second substrate, a gas adsorbent, and a glass adhesive containing glass powder and a binder is heated to remove the binder. In this method, resin is used as the binder. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] International Publication No. 2017 / 056416 [Overview of the project] [Problems that the invention aims to solve]

[0004] However, even if the binder is removed by heating as in Patent Document 1, gases originating from the binder and organic solvents, as well as gases released from bubbles contained in the glass adhesive, may remain in the reduced-pressure space (vacuum space) created by exhausting the internal space surrounded by the first substrate, the second substrate, and the molten glass adhesive. Furthermore, gases may also be released from organic contaminants adhering to the first and second substrates. Moreover, there is a possibility that the gas adsorbent may not be able to adequately adsorb these gases.

[0005] The object of this disclosure is to provide a composite getter material and a getter paste that can prevent gas from remaining in the vacuum space. [Means for solving the problem]

[0006] A composite getter material according to one aspect of the present disclosure contains at least particles made of zeolite and particles made of a cerium compound. The proportion of the cerium compound is 50% by mass or less with respect to the mass of the composite getter material. The particles made of the cerium compound have an average particle diameter of 10 nm to 30 μm.

[0007] A composite getter material according to another aspect of the present disclosure contains at least particles made of zeolite and particles made of a cerium compound. The zeolite is copper ion exchange zeolite. The particles made of the cerium compound have an average particle diameter of 10 nm to 30 μm.

[0008] A getter paste according to one aspect of this disclosure is a mixture of the composite getter material and a solvent. [Effects of the Invention]

[0009] According to this disclosure, it is possible to make it less likely for gas to remain in a vacuum space. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1A is a plan view showing an assembly that is an intermediate part of the glass panel unit according to the first embodiment. Figure 1B is a cross-sectional view taken along line AA of Figure 1A. [Figure 2] Figure 2 is a plan view showing the same glass panel unit. [Figure 3] Figure 3 is an explanatory diagram of the manufacturing method of the glass panel unit according to the first embodiment. [Figure 4] Figure 4 is an explanatory diagram of the manufacturing method of the glass panel unit according to the first embodiment. [Figure 5] Figure 5 is an explanatory diagram of the manufacturing method of the glass panel unit according to the first embodiment. [Figure 6] Figure 6 is an explanatory diagram of the manufacturing method of the glass panel unit according to the first embodiment. [Figure 7] Figure 7 is an explanatory diagram of the manufacturing method of the glass panel unit according to the first embodiment. [Figure 8] FIG. 8 is an explanatory view of a method for manufacturing a glass panel unit according to the first embodiment. [Figure 9] FIG. 9A is a plan view showing a glass panel unit according to the second embodiment. FIG. 9B is a cross-sectional view taken along line B-B of FIG. 9A. [Figure 10] FIG. 10 is an explanatory view of a method for manufacturing a glass panel unit according to the second embodiment. [Figure 11] FIG. 11 is a plan view showing an assembled product which is an intermediate of the glass panel unit according to the second embodiment. [Figure 12] FIG. 12 is an explanatory view of a method for manufacturing a glass panel unit according to the second embodiment. [Figure 13] FIG. 13 is an explanatory view of a method for manufacturing a glass panel unit according to the second embodiment. [Figure 14] FIG. 14 is an explanatory view of a method for manufacturing a glass panel unit according to the second embodiment. [Figure 15] FIG. 15A is an explanatory view showing an assembled product which is an intermediate of the glass panel unit according to the third embodiment. FIG. 15B is an explanatory view showing an assembled product which is an intermediate of the glass panel unit according to the third embodiment. [Figure 16] FIG. 16 is an explanatory view of a method for manufacturing a glass panel unit according to the fourth embodiment. [Figure 17] FIG. 17 is a graph showing the relationship between the intensity (detection intensity) corresponding to the amount of oxygen desorbed from cerium (IV) oxide powder when the cerium (IV) oxide powder is heated, and the temperature. [Figure 18] FIG. 18A is a plot showing the relationship between the addition amount of cerium (IV) oxide in a composite getter material using copper ion-exchanged zeolite powder, and the thermal conductivity of the glass panel unit. FIG. 18B is a plot showing the relationship between the addition amount of cerium (IV) oxide in a composite getter material using hydrogen ion-exchanged zeolite powder, and the thermal conductivity of the glass panel unit. [Figure 19]Figure 19 is a plot showing the relationship between the concentration of cerium(IV) oxide in the composite getter material and the thermal conductance of the glass panel unit. [Figure 20] Figure 20 is a graph showing the relationship between the amount of oxygen released from cerium(IV) oxide when cerium(IV) oxide powder is heated and the temperature. [Figure 21] Figure 21 is a plot showing the relationship between the amount of cerium(IV) oxide in the getter material and the thermal conductance of the glass panel unit. [Modes for carrying out the invention]

[0011] First, I will explain the circumstances that led to this disclosure.

[0012] Glass panel units have thermal insulation properties by forming a vacuum space between two glass plates. However, even with a vacuum space between the two glass plates, the thermal insulation of such glass panel units is thought to be reduced if gas remains in this vacuum space. Therefore, to reduce the amount of gas remaining in the vacuum space, a gas adsorbent is provided in the vacuum space (see Patent Document 1).

[0013] However, gas adsorbents often contain only one type of gas-adsorbing component. When using such a gas adsorbent, gases that are not adsorbed by the gas-adsorbing component may remain in the vacuum space as residual gas.

[0014] Furthermore, it was considered difficult to suppress gas residue in the low-pressure environment of a vacuum simply by combining two or more gas adsorption components. In other words, it was considered difficult to select two or more gas adsorption components suitable for gas adsorption in a vacuum.

[0015] Therefore, the inventors, through diligent research, discovered that various gaseous components such as water vapor, carbon dioxide, oxygen, nitrogen, and methane exist in a vacuum space, with water vapor and carbon dioxide accounting for the largest proportions. On the other hand, they found that nitrogen and methane are not easily adsorbed by gas adsorbents, and remain even when the amount of gas adsorbent is increased. For this reason, it is essential to use a gas adsorbent that can adequately adsorb nitrogen, methane, and other gases. However, nitrogen and methane are types of gases that are difficult to adsorb, and it is difficult to adequately adsorb them with general gas adsorbents, and it becomes even more difficult to achieve sufficient adsorption when using gas adsorbents in a vacuum space of 10 Pa or less.

[0016] Furthermore, generally speaking, for a gas adsorbent such as zeolite to be able to adsorb gas, any gas already adsorbed at the adsorption site must be desorbed beforehand. However, gas adsorbents that can adsorb even gases that are difficult to adsorb, such as nitrogen and methane, have strong gas adsorption capabilities, and therefore the activation energy for gas desorption is high. In other words, if a gas adsorbent is left in the atmosphere, for example, it will have already strongly adsorbed gases other than nitrogen and methane, so a great deal of energy will be required to desorb these gases. This tendency is particularly pronounced when desorbing gases at temperatures below 350°C. Moreover, if the result of using a gas adsorbent requires that the total partial pressure of nitrogen and methane be kept below 10 Pa, even stronger adsorption capabilities are needed to maintain a low equilibrium pressure, and this tendency becomes even more pronounced.

[0017] Therefore, if the manufacturing process of a glass panel unit in which a vacuum space is formed is lowered to a low temperature, it becomes difficult to sufficiently desorb gas from the gas adsorbent during the manufacturing process of the glass panel unit. Consequently, it becomes difficult to sufficiently open up the adsorption sites of the gas adsorbent, making it difficult to adequately adsorb nitrogen, methane, etc. In other words, it has been fundamentally difficult to achieve a state in which a sufficient amount of nitrogen and methane can be adsorbed by the gas adsorbent in a low-temperature process below 350°C.

[0018] This disclosure was made to address these challenges.

[0019] In the following, particles made of zeolite may be referred to as "zeolite particles," and particles made of cerium compounds may be referred to as "cerium compound particles." Zeolite particles consist mostly of zeolite, but may also contain impurities that are inevitably present. Similarly, cerium compound particles consist mostly of cerium compounds, but may also contain impurities that are inevitably present.

[0020] <First Embodiment> Next, an overview of the manufacturing method for the glass panel unit 10 according to this embodiment will be described.

[0021] The manufacturing method for the glass panel unit 10 includes a processing step, an assembly step (see Figures 3 to 5), a joining step (first melting step, see Figure 6), and an exhaust step (see Figure 6). The processing step includes a composite getter material manufacturing step to obtain a composite getter material containing at least particles made of zeolite and particles made of a cerium compound. The assembly step is a step of preparing an assembled product 100. The assembled product 100 comprises a first glass plate 200, a second glass plate 300, a frame-shaped peripheral wall 410, an internal space 500, a gas adsorbent 60, and an exhaust port 700 (see Figures 1A and 1B). The second glass plate 300 faces the first glass plate 200. The peripheral wall 410 is located between the first glass plate 200 and the second glass plate 300. The internal space 500 is surrounded by the first glass plate 200, the second glass plate 300, and the peripheral wall 410. The gas adsorbent 60 is placed within the internal space 500 and contains the composite getter material described above. The exhaust port 700 connects the internal space 500 to the external space. The joining process is a process of melting the peripheral wall 410 to hermetically join the first glass plate 200 and the second glass plate 300. The exhaust process is a process of exhausting the internal space 500 through the exhaust port 700 to create a vacuum space 50.

[0022] According to the above manufacturing method, the gas adsorbent 60 contains at least particles made of zeolite (zeolite particles) and particles made of cerium compound (cerium compound particles), thereby adsorbing gases such as CO2 that are easily adsorbed by cerium compound particles in the vacuum space 50. This prevents the zeolite adsorption sites from being filled with CO2 and ensures sufficient adsorption sites for adsorbing nitrogen, methane, etc., which can only be adsorbed by zeolite. As a result, nitrogen and methane gases, which are difficult to adsorb by either zeolite or cerium compound alone, can be sufficiently adsorbed, and these gases are less likely to remain in the vacuum space 50. In other words, the amount of residual gas in the vacuum space 50 is reduced.

[0023] In this embodiment, "getter material" refers to a material that has the property of adsorbing molecules smaller than a predetermined size. In this embodiment, zeolite particles and aggregates (powder) of multiple zeolite particles are getter materials. Cerium compound particles and aggregates (powder) of multiple cerium compound particles are also getter materials. "Composite getter material" refers to a getter material that contains multiple types of getter materials. In this embodiment, the composite getter material contains both zeolite particles and cerium compound particles. The composite getter material may also contain other getter materials other than zeolite particles and cerium compound particles.

[0024] Next, the manufacturing method of the glass panel unit 10 according to this embodiment (hereinafter sometimes referred to as the manufacturing method) will be described in detail with reference to Figures 1 to 8. This manufacturing method is a method for manufacturing the glass panel unit 10 shown in Figure 2. In this embodiment, direction D1 is parallel to the thickness direction of the first glass plate 200, direction D2 is perpendicular to direction D1, and direction D3 is perpendicular to directions D1 and D2. Direction D1 may also be a first direction, direction D2 may be a second direction, and direction D3 may be a third direction.

[0025] The manufacturing method includes a preparation step and a removal step.

[0026] The preparation step is the process of preparing the work-in-progress 110 shown in Figure 7. The work-in-progress 110 is formed from the assembled parts 100 shown in Figures 1A and 1B. In other words, the work-in-progress 110 is an intermediate product for manufacturing the glass panel unit 10 (see Figure 2), and the assembled parts 100 is an intermediate product for manufacturing the work-in-progress 110.

[0027] The preparation process includes a processing process, an assembly process (see Figures 3 to 5), a joining process (first melting process, see Figure 6), an exhaust process (see Figure 6), and a sealing process (second melting process, see Figures 6 and 7).

[0028] The processing step involves preparing a composite getter paste. This composite getter paste contains at least particles made of zeolite, particles made of cerium compound, and a solvent (e.g., water). The gas adsorbent 60 is the dried composite getter paste. As a result, even if the cerium compound releases a small amount of oxygen after the second melting step, this oxygen is adsorbed by the zeolite. Therefore, the amount of oxygen contained in the reduced-pressure space (vacuum space 50 described later) after the internal space 500 has been evacuated can be reduced. Since the cerium compound has high adsorption capacity for carbon dioxide in the reduced-pressure space, the amount of carbon dioxide contained in the reduced-pressure space can be reduced. Furthermore, by reducing the amount of carbon dioxide contained in the reduced-pressure space in this way, it is possible to prevent the adsorption sites of zeolite that can adsorb nitrogen, methane, etc. from being filled with carbon dioxide. As a result, zeolite can sufficiently adsorb nitrogen and methane, which are difficult for cerium compounds to adsorb. Therefore, the presence of zeolite and cerium compound in the reduced-pressure space reduces not only carbon dioxide but also hydrocarbons such as nitrogen and methane compared to when either is present alone, resulting in less residual gas in the reduced-pressure space.

[0029] In this embodiment, the melting points of the thermal adhesives (first thermal adhesive and second thermal adhesive) described later are not particularly limited, but the effect of mixing cerium oxide particles and copper ion exchange zeolite particles becomes significant when the melting point of the thermal adhesive is 400°C or lower, and even more significant when it is 350°C or lower. Alternatively, it becomes particularly significant when the temperature of the exhaust process is 350°C or lower. This is because, above 350°C, it becomes relatively easier to desorb the gas adsorbed by the copper ion exchange zeolite during heat treatment such as the exhaust process. In other words, even under conditions where the melting point of the thermal adhesive is 350°C or lower, or the temperature in the exhaust process is 350°C or lower, the residual gas in the reduced-pressure space can be reduced.

[0030] Furthermore, cerium oxide particles are particles containing cerium oxide as a cerium compound, and copper ion exchange zeolite particles are particles containing copper ion exchange zeolite as a zeolite.

[0031] The processing steps include a heating step, a composite getter material manufacturing step, and a mixing step. However, even if the heating step in this processing step is omitted, the effect of mixing cerium compound particles with zeolite particles can still be obtained. Therefore, it is not always necessary to perform a heating step on either the zeolite particles or the cerium compound particles.

[0032] The heating step involves heating one or both of the zeolite particles and the cerium compound particles. When heating both the zeolite particles and the cerium compound particles, they may be heated separately, or a mixture of the zeolite particles and cerium compound particles may be heated. Furthermore, when heating only one of the zeolite particles and the cerium compound particles, the remaining components do not need to be heated. Specifically, the zeolite particles may be heated without heating the cerium compound particles, or the cerium compound particles may be heated without heating the zeolite particles. The temperature in the heating step is preferably higher than the temperature in the exhaust step (exhaust temperature Te described later), more preferably higher than the temperature in the first melting step (first melting temperature Tm1 described later), and particularly preferably higher than the temperature in the second melting step (second melting temperature Tm2 described later). In this case, before manufacturing the assembly 100, the gas components adsorbed by one or both of the zeolite particles and the cerium compound particles can be desorbed. In particular, heating cerium compound particles can cause oxygen to be removed from them. This can reduce the amount of oxygen released by the cerium compound into the internal space 500, and in some cases, it can also improve the gas adsorption properties of the cerium compound particles.

[0033] Furthermore, in the heating process, heating only the zeolite particles, or both the zeolite particles and the cerium compound particles, allows the oxygen adsorbed on each of the zeolite particles and cerium compound particles to be removed by the heating process. This reduces the amount of oxygen removed in the bonding process and beyond, allowing the exhaust process to be cooled, and consequently, the first and second melting processes to be cooled. Therefore, the manufacturing cost of the glass panel unit 10 can be reduced.

[0034] Zeolite is a porous component having a plurality of zeolite structures. Therefore, zeolite particles have a plurality of pores. And gas is adsorbed in these pores. Examples of the gas adsorbed by zeolite include hydrocarbons such as water vapor, carbon dioxide, oxygen, nitrogen, and methane. Among them, zeolite can adsorb gases such as nitrogen and hydrocarbons (especially nitrogen) to which cerium compounds are difficult to adsorb in a reduced-pressure space. The zeolite structure has the composition of the following general formula (1). Me2 / XO·Al2O3·mSiO2·nH2O …(1) Here, Me is an x-valent cation present in the pores. m is the silica / alumina ratio and is an integer of 2 or more. n is an integer of 0 or more. In the composition of formula (1), a monovalent negative charge occurs for each Al. Therefore, when Me is a cation of 2 or more valences, a positive charge occurs in the pores of the zeolite particles. When Me is a monovalent cation, the inside of the pores becomes electrically neutral.

[0035] In the zeolite structure, Me may be a monovalent cation. Me may be a cation of 2 or more valences. Me may be a combination of a monovalent cation and a cation of 2 or more valences. Examples of the monovalent cation include Li + , Na + , and K + and other alkali metal ions; protons; and ammonium ions (NH4 + ), Ag + , etc. Examples of the cation of 2 or more valences include Ca 2+ , Mg 2+ , and Ba 2+ and other alkaline earth metal ions; and Cu 2+ , Au 2+ , Fe 2+ , Zn 2+ and Ni 2+ and other transition metal ions.

[0036] Examples of the zeolite structure include A-type zeolite structure, X-type zeolite structure, Y-type zeolite structure, and ZSM-5 structure. Zeolite may contain any zeolite structure other than the above structures.

[0037] The water (H2O) in general formula (1) is contained in the zeolite as crystal water. This water is contained, for example, within the pores of zeolite particles. When zeolite is heated, not only this crystal water but also gaseous components such as oxygen that were adsorbed before heating can be desorbed from the zeolite. This improves the gas adsorption properties of the zeolite. When the crystal water is completely desorbed, n in general formula (1) becomes 0.

[0038] Preferably, the zeolite obtained in the heating process has had oxygen removed and adsorbed at least one component from nitrogen, carbon monoxide, and water (hereinafter sometimes referred to as the adsorbent component). In other words, it is preferable that the adsorption capacity of the zeolite particles obtained in the heating process is saturated with the adsorbent component. In this case, the gas adsorption properties of the zeolite can be restored by the desorption of the adsorbent component during heating in the exhaust process or other processes. It should be noted that when the zeolite particles after the heating process are mixed with water, even if nitrogen or carbon monoxide is adsorbed on the zeolite, it is thought that some of it will be replaced by water.

[0039] The zeolite preferably contains copper ion exchange zeolite. This copper ion exchange zeolite is the component in which Me in general formula (1) is a copper ion. Here, copper ion exchange zeolite is the component in which copper ions are retained in the zeolite structure. Therefore, "copper ion exchange zeolite" is not limited to the component before copper ions are retained in the zeolite structure. Furthermore, the crystal structure of the zeolite is more preferably MFI type such as ZSM-5, Y type, USY type, mordenite type, ferrielite type, L type, etc. In particular, copper ion exchange ZSM-5 type zeolite (Cu-ZSM5) is more desirable because it can strongly adsorb nitrogen, methane, etc., even at room temperature and under low pressure. The molar ratio of silica / alumina of the zeolite is preferably 5 or more, and the molar ratio of silica / alumina of ZSM-5 type is preferably 10 to 45, and more preferably 20 to 40, but is not limited to this.

[0040] Cerium compounds are compounds containing cerium that have the property of adsorbing at least carbon dioxide in a reduced-pressure space. Therefore, even if the carbon dioxide adsorption capacity of zeolite particles in a reduced-pressure space is insufficient, the carbon dioxide can be adsorbed by the cerium compound particles. Cerium compounds contain, for example, at least one compound selected from the group consisting of cerium oxides such as cerium(IV) oxide (CeO2) and cerium(III) oxide (Ce2O3), cerium hydroxide, and cerium carbonate. Among these, it is preferable that the cerium compound particles contain cerium(IV) oxide. Furthermore, cerium compound particles may also contain metals such as Cu and Fe, or rare earth elements such as Sc and Y. In addition, cerium compound particles containing rare earth elements such as La, Nd, and Gd, or cerium compound particles supported with noble metals such as Au, Pt, and Pd, are also possible. Furthermore, it is desirable that the pore distribution of the cerium compound (especially in the case of cerium oxide) particles has a peak of 1 nm to 10 nm.

[0041] When the cerium compound is cerium oxide, it is preferable that the cerium oxide particles exhibit an oxygen release curve with a temperature at which the oxygen release rate is maximum in a temperature-controlled desorption gas analysis when heated at 30°C / min. It is preferable that the maximum point of this oxygen release curve is 200°C or lower. Alternatively, it is preferable that the maximum point of the oxygen release curve is 250°C or higher, and the oxygen release onset temperature of the oxygen release curve is 250°C or higher.

[0042] When cerium compound particles are reduced by heating and release oxygen, this oxygen is adsorbed onto the adsorption sites of zeolite, which tends to reduce the gas adsorption performance of the zeolite. In particular, Cu-ZSM5 gains strong gas adsorption capacity when copper oxide is reduced, so it is difficult to achieve adsorption capacity in environments where oxygen is supplied from the surroundings. Also, if cerium oxide is in a state that is easily reduced, the cerium may react with silica in the zeolite, changing the structure of the zeolite and potentially reducing the adsorption capacity of the zeolite. For cerium compounds, the higher the oxygen release initiation temperature, the higher the oxygen desorption energy, making oxygen desorption less likely and suppressing the decrease in the gas adsorption performance of the zeolite.

[0043] Therefore, in this embodiment, it is preferable that the cerium oxide particles exhibit an oxygen release curve with a temperature at which the oxygen release amount is maximum in a temperature-controlled desorption gas analysis when heated at 30°C / min. It is preferable that the maximum point of this oxygen release curve is 200°C or lower. Alternatively, it is preferable that the maximum point of the oxygen release curve is 250°C or higher, and the oxygen release onset temperature at the maximum point is 250°C or higher. This makes oxygen desorption from the cerium compound particles less likely to occur, and suppresses the decrease in the gas adsorption performance of the zeolite particles. In other words, if the cerium compound particles have an oxygen release curve with a peak at 250°C or higher, it is preferable to use cerium oxide particles that begin to release oxygen from 250°C or higher.

[0044] In this embodiment, it is preferable that the temperature at which O2 begins to desorb from the cerium compound is above the process temperature. The process temperature is the exhaust temperature Te used in the exhaust stroke described later, for example, 250°C. It is even more preferable that the temperature at which O2 begins to desorb from the cerium compound is above the melting temperature of the seal. The melting temperature of the seal is the second softening point of the second sealant described later, for example, 265°C. Furthermore, it is preferable that the temperature at which O2 begins to desorb from the cerium compound is 300°C or higher, more preferably 500°C or higher, and particularly preferably 550°C or higher.

[0045] The temperature at which O2 begins to desorb from cerium compounds varies depending on the pore size distribution of the cerium compound particles, the supporting metal of the cerium compound, and the concentration of additives. Furthermore, some supporting materials may release oxygen themselves, so these factors must also be considered when evaluating different types of cerium compounds.

[0046] Furthermore, thermal desorption gas analysis is a mass spectrometry method that uses an instrument capable of monitoring the gas generated by vacuum heating / temperature increase at each temperature, and is called TDS (Thermal Desorption Spectrometry).

[0047] The composite getter material manufacturing process is a process of obtaining a composite getter material using zeolite particles and cerium compound particles after or before the heating process. During the composite getter material manufacturing process, the zeolite particles and cerium compound particles are mixed. In this embodiment, the composite getter material contains a first getter material containing zeolite particles and a second getter material containing cerium compound particles. The composite getter material may also contain getter materials other than the first and second getter materials. The composite getter material also includes a sintered body of a composite powder of the first and second getter materials. Alternatively, it may be formed by combining single getter materials to create a sintered body.

[0048] The average particle size of the zeolite particles and the cerium compound particles are preferably in the range of 0.001 μm to 30 μm, respectively, but are not particularly limited to this range. If the average particle size of the zeolite particles and the cerium compound particles are within the above range, they mix easily and have excellent gas adsorption performance. In particular, it is preferable that the average particle size of the zeolite particles and the cerium compound particles are in the range of 0.3 μm to 2 μm, respectively.

[0049] The proportion of cerium compounds in the composite getter material is preferably 50% by mass or less relative to the mass of the composite getter material. In this case, the amount of oxygen detached from the cerium compound can be reduced, making it less likely for this oxygen to remain in the internal space 500 (vacuum space 50) after the second melting process. The proportion of cerium compound particles in the composite getter material is preferably smaller than the proportion of zeolite particles. That is, the proportion of zeolite particles is preferably larger than the proportion of cerium compound particles. The larger the proportion of zeolite particles, the less likely nitrogen and hydrocarbons, which are difficult for cerium compound particles to adsorb, are to remain in the reduced pressure space because they are adsorbed by the zeolite particles. Moreover, the oxygen detached from the cerium compound particles after the second melting process makes it less likely for the adsorption capacity of the zeolite particles to be saturated. The proportion of cerium compound particles is more preferably 40% by mass or less, even more preferably 20% by mass or less, and particularly preferably 15% by mass or less. The lower limit of the proportion of cerium compound particles is not particularly limited, but the proportion of cerium compound particles is, for example, greater than 0% by mass, preferably 0.5% by mass or more, more preferably 1% by mass or more, and particularly preferably 2% by mass or more.

[0050] Furthermore, if a heating process is performed and the zeolite particles and cerium compound particles are mixed during the heating process, the getter material preparation process is performed simultaneously with the heating process. After the getter material preparation process, the mixing process is performed.

[0051] In this embodiment, for the purpose of the composite getter material, the zeolite particles and cerium oxide particles do not need to be supported on each other. For this reason, it is desirable that the average particle size of the zeolite particles and cerium oxide particles be at least 10 nm. This is to prevent the particles from diffusing into the pores of the zeolite particles or cerium oxide particles and degrading their performance. More preferably, the average particle size of the zeolite particles and cerium oxide particles is 20 nm or more, and even more preferably 50 nm or more. This suppresses the adhesion of cerium oxide fine particles to the zeolite particles or cerium oxide fine particles, and allows for a large surface area to be maintained. For example, it is desirable to mix Cu-ZSM5 powder with an average particle size of 50 nm or more with cerium oxide powder with an average particle size of 20 nm or more. In this disclosure, the average particle size may be considered as the equivalent spherical diameter observed by microscopy using TEM or SEM.

[0052] The mixing step is a process of mixing the composite getter material with a solvent to obtain a getter paste. When water is used as the solvent, the water in the getter paste is present in a way that covers the composite getter material. As a result, the composite getter material is less likely to come into contact with air in the state of the getter paste. In other words, the composite getter material is less likely to adsorb air (especially oxygen in the air). Therefore, the storage of the getter paste becomes easier, and the complexity of manufacturing the glass panel unit 10 can be reduced. The water content in the getter paste can be arbitrarily selected. Water can be used as the solvent. Alternatively, a solution with water as the main component can be used as the solvent. For example, the solvent may be water mixed with organic matter or components such as calcium and sodium as impurities. Alternatively, the solvent may be water mixed with an organic solvent such as ethanol at a concentration of 50% by mass or less. Alternatively, the solvent may be ethanol or an organic solvent such as butyl carbitol acetate or terpineol, or mixtures thereof. In addition, a common organic binder such as polycarbonate or polyisobutyl methacrylate may be added. For example, using highly viscous organic solvents or organic binders can suppress the sedimentation of solids and improve coating performance. Furthermore, in the case of a paste made by mixing copper ion-exchange zeolite particles and cerium oxide particles with water, it was confirmed that the performance slightly deteriorated when stored as a paste for a long period of time. This is thought to be because a slight reaction occurs between cerium oxide and copper ion-exchange zeolite in the aqueous solvent. Therefore, under certain conditions, such as when long-term storage is required, organic solvents may be more advantageous. In addition, since cerium compound particles also adsorb carbon dioxide released when organic solvents or organic binders decompose, the effect of mixing cerium compound particles, zeolite particles, and solvent is greater. However, assuming that the coating is applied relatively quickly, it is recommended to use pure water, ultrapure water, ion-exchanged water, distilled water, etc., whenever possible. However, this is more desirable in order to suppress the adverse effect of the solvent on the adsorption capacity of the zeolite particles. After the mixing process, the assembly process is carried out.

[0053] The assembly process is the process of preparing the assembled product 100.

[0054] As shown in Figures 1A and 1B, assembly 100 comprises a first glass plate 200, a second glass plate 300, a peripheral wall 410, and a partition 420. Assembly 100 also has an internal space 500 enclosed by the first and second glass plates 200, 300 and the peripheral wall 410. Furthermore, within the internal space 500, assembly 100 includes a gas adsorbent 60 and a plurality of pillars (spacers) 70. Finally, assembly 100 includes an exhaust port 700.

[0055] The first glass plate (first glass substrate) 200 is a base component for the first glass plate 20 described later, and is made of the same material as the first glass plate 20. The second glass plate (second glass substrate) 300 is a base component for the second glass plate 30 described later, and is made of the same material as the second glass plate 30. The first and second glass plates 200 and 300 have the same planar shape. In this embodiment, the first glass plate 200 is sized to form at least one of the first glass plates 20 described later, and the second glass plate 300 is sized to form at least one of the second glass plates 30 described later.

[0056] The first and second glass plates 200 and 300 are both polygonal (rectangular in this embodiment) flat plates.

[0057] The first glass plate 200 includes a main body 210 and a low-emissivity film 220.

[0058] The low-emissivity film 220 is located within the internal space 500 and covers the main body 210. The low-emissivity film 220 is in contact with the main body 210. The low-emissivity film 220 is also called an infrared reflective film and, although it is translucent, it reflects infrared rays. For this reason, the low-emissivity film 220 can improve the thermal insulation of the glass panel unit 10. The low-emissivity film 220 is, for example, a thin film made of metal. The low-emissivity film 220 contains, for example, silver. An example of a low-emissivity film 220 is a Low-E film.

[0059] The first glass plate 200 includes a body 210 as described above. The body 210 has a first surface 211 and a second surface 212. The first surface 211 is a flat surface covered with a low-emissivity film 220. The second surface 212 is parallel to the first surface 211 and is a flat surface located on the opposite side of the internal space 500 in direction D1. The body 210 is a rectangular flat plate as it constitutes the main shape of the first glass plate 200. The material of the body 210 is, for example, soda-lime glass, high-strain point glass, chemically strengthened glass, alkali-free glass, quartz glass, neoceram, or physically strengthened glass.

[0060] The second glass plate 300 includes a main body 310. The main body 310 has a first surface 311 and a second surface 312. The first surface 311 is a flat surface facing the low-emission film 220. The second surface 312 is parallel to the first surface 311 and is a flat surface on the opposite side of the internal space 500 in direction D1. The main body 310 is a rectangular flat plate to constitute the main shape of the second glass plate 300. The main body 310 has the same shape as the main body 210. In this embodiment, the second glass plate 300 consists only of the main body 310, but it may also be equipped with a low-emission film similar to the low-emission film 220 in addition to the main body 310. If the second glass plate 300 is equipped with a low-emission film, this low-emission film covers the main body 310 and is in contact with the main body 310 within the internal space 500. The materials for the main body 310 include, for example, soda-lime glass, high-strain point glass, chemically strengthened glass, alkali-free glass, quartz glass, neoceram, and physically strengthened glass.

[0061] The peripheral wall 410 contains a first sealant (first thermal adhesive). The peripheral wall 410 is positioned between the first glass plate 200 and the second glass plate 300. The peripheral wall 410 is frame-shaped, as shown in Figure 1A. In particular, the peripheral wall 410 is rectangular in shape. The peripheral wall 410 is formed along the outer periphery of the first and second glass plates 200 and 300. As a result, in the assembly 100, an internal space 500 is formed surrounded by the peripheral wall 410, the first glass plate 200, and the second glass plate 300.

[0062] The first thermal adhesive includes, for example, glass frit. Examples of glass frit include low-melting-point glass frit. Examples of low-melting-point glass frit include bismuth-based glass frit, lead-based glass frit, and vanadium-based glass frit. Furthermore, the first thermal adhesive is not limited to glass frit and may include, for example, a low-melting-point metal or a hot-melt adhesive. The first thermal adhesive may further include one or both of an organic binder and an organic solvent. In this case, even if a gas originating from one or both of the organic binder and the organic solvent is released into the vacuum space 50 after the sealing step (second melting step), the gas adsorbent 60 will adsorb this gas, making it less likely for the gas to remain in the vacuum space 50.

[0063] The organic binder includes, for example, a resin. Examples of such resins include polyisobutyl methacrylate, ethyl cellulose, aliphatic polycarbonate, acrylic resin, and butyral resin. The organic binder is not limited to the above resins and may contain any other components. The resin constituting the organic binder is preferably a low molecular weight resin that is easily decomposed.

[0064] Examples of organic solvents include esters such as butyl carbitol acetate and ethyl carbitol. However, the organic solvent is not limited to the above components and may include at least one of the solvents commonly used in screen printing, such as terpene solvents, and solvents used in dispensing.

[0065] If the peripheral wall 410 further contains resin, even if gas derived from this resin is released into the internal space 500 after the assembly process, the resin-derived gas is exhausted by the exhaust process. Even if the resin-derived gas remains as residual gas in the vacuum space 50 after the exhaust process, the gas adsorbent 60 can adsorb this residual gas.

[0066] The partition 420 is positioned within the internal space 500. The partition 420 divides the internal space 500 into a first space 510 and a second space (ventilation space) 520. Therefore, the first space 510 is the space from which exhaust is performed during the exhaust process, and the second space 520 is the space used for exhausting the first space 510. The partition 420 is formed on the first end side (right end side in Figure 1A) of the second glass plate 300 in the longitudinal direction (left-right direction in Figure 1A) rather than the center of the second glass plate 300, such that the first space 510 is larger than the second space 520. The partition 420 is positioned within the internal space 500 along the width direction (up-down direction in Figure 1A) of the second glass plate 300. However, both ends of the partition 420 in the longitudinal direction are not in contact with the peripheral wall 410. In this embodiment, the width direction of the second glass plate 300 is parallel to direction D2, and the length direction of the second glass plate 300 is parallel to direction D3.

[0067] The partition 420 comprises a main body portion (partition main body portion) 421 that constitutes its body, and a blocking portion 422. The blocking portion 422 comprises a first blocking portion 4221 and a second blocking portion 4222. The main body portion 421 is linear along direction D2. This direction D2 is, for example, the width direction of the second glass plate 300. Also, in direction D2, both ends of the main body portion 421 are not in contact with the peripheral wall 410. Of the ends of the main body portion 421, the first blocking portion 4221 is formed so as to extend toward the second space 520 from one end, and the second blocking portion 4222 is formed so as to extend toward the second space 520 from the other end. One end of the main body portion 421 may be the first end (upper end side in Figure 1A), and the other end (lower end side in Figure 1A) may be the second end.

[0068] The partition 420 includes a second sealant (second thermal adhesive). The second thermal adhesive is, for example, glass frit. Examples of glass frit include low-melting-point glass frit. Examples of low-melting-point glass frit include bismuth-based glass frit, lead-based glass frit, and vanadium-based glass frit. Furthermore, the second thermal adhesive is not limited to glass frit, and may be, for example, a low-melting-point metal or a hot-melt adhesive. In this embodiment, the first thermal adhesive and the second thermal adhesive are the same. In other words, the first sealant and the second sealant are made of the same material.

[0069] As shown in Figure 1A, the ventilation passage 600 connects the first space 510 and the second space 520 within the internal space 500. The ventilation passage 600 includes the first ventilation passage 610 and the second ventilation passage 620. The first ventilation passage 610 is the gap between the first end of the partition 420 (the upper end in Figure 1A) and the peripheral wall 410. The second ventilation passage 620 is the gap between the second end of the partition 420 (the lower end in Figure 1A) and the peripheral wall 410.

[0070] The exhaust port 700 is a hole connecting the second space 520 to the external space. The exhaust port 700 is used to exhaust the first space 510 through the second space 520 and the ventilation passage 600 (first ventilation passage 610 and second ventilation passage 620). Therefore, the ventilation passage 600, the second space 520, and the exhaust port 700 constitute an exhaust passage for exhausting the first space 510. The exhaust port 700 is formed in the second glass plate 300 so as to connect the second space 520 to the external space. Specifically, the exhaust port 700 is located at the corner of the second glass plate 300.

[0071] The gas adsorbent 60 and the multiple spacers 70 are arranged within the first space 510. In particular, the gas adsorbent 60 is formed along the width direction of the second glass plate 300 on the second end side in the longitudinal direction of the second glass plate 300 (the left end side in Figure 1A). In other words, the gas adsorbent 60 is positioned at the edge of the first space 510 (vacuum space 50). This makes the gas adsorbent 60 less conspicuous. Furthermore, the gas adsorbent 60 is located away from the partition 420 and the ventilation passage 600. Therefore, the possibility of the gas adsorbent 60 obstructing exhaust during the exhaust of the first space 510 is reduced.

[0072] The assembly process involves forming a first glass plate 200, a second glass plate 300, a peripheral wall 410, a partition 420, an internal space 500, a ventilation passage 600, an exhaust port 700, a gas adsorbent 60, and a plurality of spacers 70 in order to obtain an assembled product 100. The assembly process has six steps, from the first to the sixth. The order of the second to fifth steps may be changed as appropriate.

[0073] The first step is the process of forming the first glass plate 200 and the second glass plate 300 (substrate formation process). For example, in the first step, the first glass plate 200 and the second glass plate 300 are manufactured, and the first glass plate 200 and the second glass plate 300 are cleaned as necessary.

[0074] The second step is to form the exhaust port 700. In the second step, the exhaust port 700 is formed on the second glass plate 300. Also in the second step, the second glass plate 300 is cleaned as needed.

[0075] The third step is the step of forming the spacers 70 (spacer forming step) (see Figure 3). In the third step, multiple spacers 70 are formed in advance, and the multiple spacers 70 are placed in predetermined positions on the second glass plate 300 using a chip mounter or the like. The multiple spacers 70 are used to maintain a predetermined distance between the first and second glass plates 200 and 300 when the assembled product 100 is in work-in-progress 110. Examples of materials that make up such spacers 70 include metal, glass, and resin. The spacers 70 may include one or more of these materials.

[0076] In the third step of this embodiment, as described above, the spacers 70 are formed in advance and placed on the second glass plate 300. However, multiple spacers 70 may be formed on the second glass plate 300 using well-known thin-film formation techniques. Furthermore, if the spacers 70 contain resin, the multiple spacers 70 may be formed using photolithography and etching techniques, as a method different from the above-described formation method. In this case, the multiple spacers 70 can be formed using photocurable materials or the like.

[0077] The size of the spacers 70, the number of spacers 70, the spacing between the spacers 70, and the arrangement pattern of the spacers 70 can be selected as appropriate. Each spacer 70 is cylindrical in shape and has a height approximately equal to the predetermined spacing. For example, a spacer 70 has a diameter of 1 mm and a height of 100 μm. Each spacer 70 may also have any desired shape, such as a prismatic or spherical shape.

[0078] The fourth step is the step of forming the gas adsorbent 60 (gas adsorbent formation step) (see Figure 3). In the fourth step, the getter paste from the processing step is applied onto the second glass plate 300 using a dispenser or the like. Then, the gas adsorbent 60 is formed by drying the applied getter paste. In other words, the fourth step includes a drying step of drying the getter paste. By drying the getter paste, the gas adsorption properties of the composite getter material can be restored. In addition, by applying the getter paste, the size of the gas adsorbent 60 can be reduced. Therefore, the gas adsorbent 60 can be placed even if the first space 510 is narrow.

[0079] The fifth step is the step of arranging the peripheral wall 410 and the partition 420 (sealant arrangement step) (see Figure 3). In the fifth step, the first sealant is applied to the second glass plate 300 using a dispenser or the like, and then the first sealant is dried to form the peripheral wall 410. Also, the second sealant is applied to the second glass plate 300 using a dispenser or the like, and then the second sealant is dried to form the partition 420.

[0080] Upon completion of steps 1 through 5, a second glass plate 300 is obtained, as shown in Figure 3. This second glass plate 300 has a peripheral wall 410, a partition 420, a ventilation passage 600, an exhaust port 700, a gas adsorbent 60, and a plurality of spacers 70 formed thereon.

[0081] The sixth step is the arrangement step of the first glass plate 200 and the second glass plate 300. In the sixth step, as shown in Figure 4, the first glass plate 200 and the second glass plate 300 are arranged parallel to each other and facing each other.

[0082] The assembly process described above yields the assembled product 100 shown in Figure 5. Following the assembly process, the first melting process (joining process), the exhaust process, and the second melting process (sealing process) are performed as shown in Figure 6.

[0083] The first melting step is a step in which the peripheral wall 410 is melted and the first glass plate 200 and the second glass plate 300 are airtightly joined by the peripheral wall 410. Specifically, the first glass plate 200 and the second glass plate 300 are placed in the melting furnace and heated at a first melting temperature Tm1 for a predetermined time (first melting time) tm1 (see Figure 6). In this embodiment, since the first sealant and the second sealant are made of the same material as described above, the softening point of the first sealant (first softening point) is the same as the softening point of the second sealant (second softening point). For this reason, the first melting temperature Tm1 is set to be above the first and second softening points. Even if the first melting temperature Tm1 is above the first and second softening points, the exhaust step is started after the first melting step (see Figure 6), so the partition 420 does not block the ventilation passage 600 during the first melting step. In other words, an air passage 600 is ensured in the first melting process. In the first melting process, for example, if the first and second softening points are 265°C, the first melting temperature Tm1 is set to 285°C. Also, the first melting time tm1 is, for example, 15 minutes.

[0084] In this embodiment, the configuration in which the first softening point is the same as the second softening point includes not only the configuration in which the first softening point is exactly the same as the second softening point, but also the configuration in which the first softening point is approximately the same as the second softening point.

[0085] By heating the peripheral wall 410 at a first melting temperature Tm1, the peripheral wall 410 can be softened while suppressing deformation of the partition 420. This makes it easier to airtightly join the first glass plate 200 and the second glass plate 300 using the peripheral wall 410.

[0086] The exhaust process is a process of exhausting the first space 510 through the ventilation passage 600, the second space 520, and the exhaust port 700 to make the first space 510 a vacuum space 50. Exhaust is performed, for example, using a vacuum pump. As shown in Figure 5, the vacuum pump is connected to the assembly 100 by an exhaust pipe 810 and a seal head 820. The exhaust pipe 810 is joined to the second glass plate 300, for example, so that the inside of the exhaust pipe 810 and the exhaust port 700 are in communication. The seal head 820 is then attached to the exhaust pipe 810, thereby connecting the intake port of the vacuum pump to the exhaust port 700. The first melting process, the exhaust process, and the second melting process are performed with the assembly 100 still in the melting furnace. Therefore, the exhaust pipe 810 is joined to the second glass plate 300 at least before the first melting process.

[0087] In the exhaust process, before the start of the second melting process, the first space 510 is exhausted through the ventilation passage 600, the second space 520, and the exhaust port 700 at an exhaust temperature Te or higher for a predetermined time (exhaust time) te or longer (see Figure 6). The exhaust temperature Te is set lower than the second softening point of the second sealant (e.g., 265°C). For example, the exhaust temperature Te is 250°C. In this way, the partition 420 does not deform even during the exhaust process. During the exhaust process, at least the moisture in the gas adsorbent 60 vaporizes and is released into the first space 510, and the first space 510 is discharged through the ventilation passage 600, the second space 520, and the exhaust port 700. By exhausting the moisture released from the gas adsorbent 60, the gas adsorption properties of the composite getter material can be further restored. The exhaust time te is set so that a vacuum space 50 with a desired vacuum level (e.g., a vacuum level of 0.1 Pa or less) can be obtained. For example, the exhaust time te is set to 120 minutes.

[0088] The second melting step is a step in which a partition wall 42 is formed by deforming the partition 420 to block at least the ventilation passage 600, thereby obtaining a work-in-progress product 110. In other words, in the second melting step, the partition 420 is deformed to block the ventilation passage 600. To put it another way, the first space 510 is blocked by the deformed partition 420, and the first space 510 and the second space 520 are separated. This forms a frame 40 surrounding the vacuum space 50 (see Figure 7). In this embodiment, the partition 420 is deformed so that both ends of the partition 420 in the longitudinal direction (first and second blocking parts 4221, 4222) are in contact with the peripheral wall 410 and become one. As a result, as shown in Figure 7, a partition wall 42 is formed that hermetically separates the internal space 500 into the first space 510 (vacuum space 50) and the second space 520. More specifically, the partition 420 is deformed by melting it at a predetermined temperature (second melting temperature) Tm2 above the second softening point of the second sealant. Specifically, the first glass plate 200 and the second glass plate 300 are heated in a melting furnace at the second melting temperature Tm2 for a predetermined time (second melting time) tm2 (see Figure 6). The second melting temperature Tm2 and the second melting time tm2 are set so that the partition 420 softens and the ventilation passage 600 is blocked. The lower limit of the second melting temperature Tm2 is the second softening point (e.g., 265°C). The second melting temperature Tm2 is set to, for example, 290°C. The second melting time tm2 is, for example, 30 minutes. The sealing step in this embodiment is the second melting step, but the sealing step is, in short, This is a process of spatially separating the vacuum space 50 from the space other than the vacuum space 50. In this embodiment, the space other than the vacuum space 50 corresponds to the second space 520.

[0089] In this embodiment, as shown in Figure 6, the exhaust process is started after the first melting process and ends at the end of the second melting process. Therefore, during the second melting process, the first space 510 is exhausted through the ventilation passage 600, the second space 520, and the exhaust port 700. As a result, a pressure difference is created inside and outside the assembly 100, and this pressure difference causes the first and second glass plates 200 and 300 to move closer to each other. Thus, in the second melting process, at the second melting temperature Tm2, ​​the first space 510 is exhausted through the ventilation passage 600, the second space 520, and the exhaust port 700, while the partition 420 is deformed to form a partition wall 42 that blocks the ventilation passage 600.

[0090] Furthermore, in the second melting process shown in Figure 6, after the second melting time tm2 has elapsed, the temperature inside the melting furnace is cooled at a constant rate to room temperature. Then, the second melting process and the exhaust process are completed by removing the seal head 820.

[0091] The above preparation process yields the work-in-progress 110 shown in Figure 7. As shown in Figure 7, the work-in-progress 110 comprises a first glass plate 200, a second glass plate 300, a peripheral wall 41, and a partition wall 42. The work-in-progress 110 also has a vacuum space 50 and a second space 520. Furthermore, within the vacuum space 50, the work-in-progress 110 includes a gas adsorbent 60 and a plurality of pillars (spacers) 70. The work-in-progress 110 also includes an exhaust port 700.

[0092] The first and second glass plates 200 and 300 are both rectangular and flat. The first and second glass plates 200 and 300 have the same planar shape.

[0093] The partition wall 42 spatially separates the vacuum space 50 from the second space 520. In other words, since the second space 520 of the work-in-progress 110 is spatially connected to the outside space via the exhaust port 700, the partition wall 42 separates the vacuum space 50 from the outside space. The partition wall 42 and the peripheral wall 410 then form a frame 40 that surrounds the vacuum space 50. The frame 40 completely encloses the vacuum space 50 and hermetically joins the first glass plate 200 and the second glass plate 300.

[0094] The gas adsorbent 60 is placed in the vacuum space 50. Specifically, the gas adsorbent 60 is a long, flat plate and is placed on the second glass plate 300. The gas adsorbent 60 is used to adsorb unwanted gases (residual gases, etc.). Unwanted gases are, for example, gases released from the thermal adhesives (first thermal adhesive and second thermal adhesive) that form the frame 40 when they are heated.

[0095] Multiple spacers 70 are placed within the vacuum space 50. The multiple spacers 70 are used to maintain the distance between the first and second glass plates 200, 300 at a desired value.

[0096] As described above, the vacuum space 50 is formed by evacuating the first space 510 through the second space 520 and the exhaust port 700. In other words, the vacuum space 50 is the first space 510 with a vacuum level below a predetermined value. The predetermined value is, for example, 0.1 Pa. Since the vacuum space 50 is completely sealed by the first glass plate 200, the second glass plate 300, and the frame 40, it is separated from the second space 520 and the exhaust port 700.

[0097] The removal process is performed after the preparation process. As shown in Figure 8, the removal process involves removing the portion 11 having the second space 520 from the work-in-progress 110 to obtain the glass panel unit 10, which is the portion having the vacuum space 50.

[0098] The glass panel unit 10 comprises a first glass plate 20 and a second glass plate 30. The first glass plate 20 is the portion of the first glass plate 200 corresponding to the first space 510 (vacuum space 50), and the second glass plate 30 is the portion of the second glass plate 300 corresponding to the first space 510 (vacuum space 50).

[0099] On the other hand, the unnecessary portion 11 includes the portion 230 of the first glass plate 200 corresponding to the second space 520, and the portion 320 of the second glass plate 300 corresponding to the second space 520. It is preferable that the unnecessary portion 11 be as small as possible, considering the manufacturing cost of the glass panel unit 10.

[0100] In the removal process, specifically, the work-in-progress 110 removed from the melting furnace is cut along the partition wall 42, dividing it into a portion (glass panel unit) 10 having a vacuum space 50 and a portion (unnecessary portion) 11 having a second space 520. The shape of the cutting line (the part where the work-in-progress 110 is cut) is determined by the shape of the glass panel unit 10. Since the glass panel unit 10 is rectangular, the cutting line is a straight line along the length of the partition wall 42.

[0101] After the preparation and removal processes described above, the glass panel unit 10 shown in Figure 2 is obtained.

[0102] Figure 2 shows a glass panel unit (finished product of the glass panel unit) 10 of this embodiment. The glass panel unit 10 comprises a first glass plate 20, a second glass plate 30, and a frame 40. The glass panel unit 10 also has a vacuum space 50 surrounded by the first and second glass plates 20, 30 and the frame 40. Furthermore, the glass panel unit 10 includes a gas adsorbent 60 and a plurality of pillars (spacers) 70 within the vacuum space 50. The glass panel unit 10 does not have exhaust ports 700 on the first and second glass plates 20, 30.

[0103] The first and second glass plates 20 and 30 are both rectangular flat plates. The first and second glass plates 20 and 30 have the same planar shape.

[0104] The first glass plate 20 in this embodiment is obtained by removing the unnecessary portion 230 of the first glass plate 200 in a removal process. Therefore, the first glass plate 20 has the same configuration as the first glass plate 200. That is, the first glass plate 20 includes a main body that constitutes its main shape and a low-emission film 220. This main body is covered with the low-emission film 220 in a vacuum space 50. The first glass plate 20 is a rectangular flat plate.

[0105] In this embodiment, the second glass plate 30 is obtained by removing the unnecessary portion 320 of the second glass plate 300 through a removal process. Therefore, the second glass plate 30 has the same configuration as the second glass plate 300. That is, the second glass plate 30 has a main body that constitutes its main shape. In this embodiment, the second glass plate 30 consists only of its main body, but it may also have a low-emission film similar to the low-emission film 220 in addition to this main body. If the second glass plate 30 has a low-emission film, this low-emission film covers the main body of the second glass plate 30 and is in contact with this main body in the vacuum space 50.

[0106] The frame 40 is located between the first glass plate 20 and the second glass plate 30, and hermetically joins the first glass plate 20 and the second glass plate 30. As a result, the vacuum space 50 is enclosed by the first glass plate 20, the second glass plate 30, and the frame 40. The frame 40 is a polygonal frame (a quadrilateral in this embodiment) similar to the first and second glass plates 20 and 30. The frame 40 is formed along the outer circumference of the first and second glass plates 20 and 30.

[0107] Multiple spacers 70 are placed within the vacuum space 50. The multiple spacers 70 are used to maintain the distance between the first and second glass plates 20 and 30 at a desired value.

[0108] The gas adsorbent 60 contains a composite getter material. That is, the gas adsorbent 60 has both a first getter material, which is zeolite particles, and a second getter material, which is cerium compound particles. In this case, the gas adsorbent 60 is composed of a mixture (powder) of particles containing zeolite particles and cerium compound particles.

[0109] <Second Embodiment> Next, the manufacturing method of the glass panel unit 10A according to this embodiment (hereinafter sometimes simply referred to as the manufacturing method) will be described with reference to Figures 9A to 14. In the following, components that overlap with those of the first embodiment may be denoted by the same reference numerals in the drawings and their description may be omitted. In this embodiment, direction D1 is parallel to the thickness direction of the first glass plate 20, direction D2 is perpendicular to direction D1, and direction D3 is perpendicular to directions D1 and D2.

[0110] The manufacturing method of this embodiment is a method for manufacturing a glass panel unit 10A as shown in Figures 9A and 9B.

[0111] The glass panel unit 10A comprises a first glass plate 20, a second glass plate 30, a frame 40, a hole sealing material 43, and a gas adsorbent 60. The glass panel unit 10A also has a vacuum space 50 surrounded by the first and second glass plates 20, 30 and the frame 40. Furthermore, the glass panel unit 10A includes a plurality of pillars (spacers) 70 and a weir member 47 within the vacuum space 50.

[0112] The first and second glass plates 20 and 30 are both rectangular flat plates. The first and second glass plates 20 and 30 have the same planar shape.

[0113] The first glass plate 20 includes a main body 21, a low-emission film 220, and an exhaust port 700. The low-emission film 220 is located in the vacuum space 50 and covers the main body 21. The exhaust port 700 is sealed with a hole sealing material 43. The low-emission film 220 is in contact with the main body 21. The main body 21 is a rectangular flat plate as it constitutes the main shape of the first glass plate 20. Examples of materials for the main body 21 include soda-lime glass, high-strain point glass, chemically strengthened glass, alkali-free glass, quartz glass, neoceram, and physically strengthened glass. The main body 21 has the same shape as the first glass plate 20.

[0114] The second glass plate 30 comprises a body 31. The body 31 is a rectangular flat plate, as it constitutes the main shape of the second glass plate 30. In this embodiment, the second glass plate 30 consists only of the body 31, but it may also be provided with a low-emission film similar to the low-emission film 220 in addition to the body 31. When the second glass plate 30 is provided with a low-emission film, this low-emission film covers the body 31 and is in contact with the body 31 in the vacuum space 50. Examples of materials for the body 31 include soda-lime glass, high-strain point glass, chemically strengthened glass, alkali-free glass, quartz glass, neoceram, and physically strengthened glass.

[0115] As shown in Figure 9A, the weir member 47 has an annular (for example, C-shaped) form with a portion cut out. In a plan view, the weir member 47 is positioned along the periphery of the exhaust port 700. This allows the weir member 47 to retain the hole sealing material 43 within the space on its inner circumference. As a result, the hole sealing material 43 can seal the exhaust port 700.

[0116] In this embodiment, the above-described glass panel unit 10A is obtained by performing a processing step, an assembly step (see Figures 10 to 11), a joining step (melting step, see Figure 12), an exhaust step (see Figures 12 to 13), and a sealing step (see Figures 12 and 14). However, the manufacturing method of this embodiment does not include the removal step of the first embodiment.

[0117] The processing step is the same as in the first embodiment, a step of preparing getter paste. The processing step includes a heating step, a composite getter material manufacturing step, and a mixing step. The temperature of the heating step is preferably higher than the temperature of the sealing step (sealing temperature Ts described later), and more preferably higher than the temperature of the melting step (melting temperature Tm described later). However, the heating step can be omitted.

[0118] The assembly process involves preparing an assembled product 101 as shown in Figure 11. The assembled product 101 comprises first and second glass plates 20, 30 and a peripheral wall 410, as shown in Figures 10 and 11. The assembled product 101 also has an internal space 500 enclosed by the first and second glass plates 20, 30 and the peripheral wall 410. Furthermore, the assembled product 101 contains a gas adsorbent 60, a plurality of pillars (spacers) 70 and a weir member 47 within the internal space 500. The assembled product 101 also has an exhaust port 700. In the assembled product 101, the internal space 500 is not vented, the peripheral wall 410 and the weir member 47 are not melted and hardened, and the exhaust port 700 is not sealed.

[0119] The weir member 47 contains a sealing material (thermal adhesive). The weir member 47 is formed on the second glass plate 30 and within the internal space 500. The weir member 47 has an annular shape (for example, C-shaped) with a portion cut out, along the outer circumference of the exhaust port 700. The weir member 47 is formed spaced apart from the peripheral wall 410 but close to the peripheral wall 410. That is, the weir member 47 is formed at the edge of the internal space 500. The weir member 47 contains the same sealing material as the peripheral wall 410. Forming this weir member 47 has the effect of stabilizing the shape after the hole sealing material 43 is pressed in during the sealing process, but the weir member 47 is not required.

[0120] The assembly process involves forming the first glass plate 20, the second glass plate 30, the gas adsorbent 60, the peripheral wall 410, the weir member 47, the internal space 500, the exhaust port 700, and a plurality of spacers 70 in order to obtain the assembled product 101. The assembly process has steps 1 to 6. The order of steps 4 and 5 may be changed as appropriate.

[0121] The first step is the process of forming the first glass plate 20 and the second glass plate 30 (glass plate forming step). For example, in the first step, the first glass plate 20 and the second glass plate 30 are made into plate shapes. Also in the first step, the first glass plate 20 and the second glass plate 30 are washed as needed.

[0122] The second step is to form the exhaust port 700. In the second step, for example, the exhaust port 700 is formed on the first glass plate 20. In the second step, the first glass plate 20 is also cleaned as needed.

[0123] The third step is the step of forming the spacers 70 (spacer formation step). In the third step, multiple spacers 70 are formed in advance, and the multiple spacers 70 are placed in predetermined positions on the second glass plate 30 using a chip mounter or the like. The multiple spacers 70 may be formed using photolithography and etching techniques. In this case, the multiple spacers 70 are formed using a photocurable material or the like. Alternatively, the multiple spacers 70 may be formed using well-known thin-film formation techniques. Furthermore, the multiple spacers 70 may be formed by punching or laser processing a resin film.

[0124] The fourth step is the step of arranging the peripheral wall 410 and the weir member 47 (sealant arrangement step). In the fourth step, sealant is applied to the second glass plate 30 along the outer circumference of the second glass plate 30 using a dispenser or the like to form a frame-shaped sealant, and then the frame-shaped sealant is dried to form the peripheral wall 410 (see Figure 10). Alternatively, sealant is applied to the second glass plate 30 at a position close to the peripheral wall 410 but at a distance from the peripheral wall 410 using a dispenser or the like to form an annular sealant with a portion cut out, and then the annular sealant is dried to form the weir member 47 (see Figure 10). In the fourth step, the frame-shaped sealant and the annular sealant may be dried and pre-fired. For example, the second glass plate 30 with the frame-shaped sealant and the annular sealant formed on it is heated at 480°C for 20 minutes. In this case, the first glass plate 20 may be heated together with the second glass plate 30. That is, the first glass plate 20 may be heated under the same conditions as the second glass plate 30 (480°C for 20 minutes). This reduces the difference in warping between the first glass plate 20 and the second glass plate 30.

[0125] The fifth step is the step of forming the gas adsorbent 60 (gas adsorbent formation step). In the fifth step, the getter paste from the processing step is applied onto the second glass plate 30 using a dispenser or the like. The gas adsorbent 60 is then formed by drying the applied getter paste. In other words, the fifth step includes a drying step for drying the getter paste.

[0126] Upon completion of steps 1 through 5, a second glass plate 30 is obtained, which has a peripheral wall 410, a weir member 47, a gas adsorbent 60, and a plurality of spacers 70 formed thereon. In this embodiment, step 6 is performed after steps 1 through 5 are completed.

[0127] The sixth step is the arrangement step of the first glass plate 20 and the second glass plate 30. In the sixth step, as shown in Figure 10, the first glass plate 20 and the second glass plate 30 are arranged parallel to each other and facing each other.

[0128] The assembly process described above yields the assembled product 101 shown in Figure 11. Following the assembly process, a melting process (joining process), an exhaust process, and a sealing process are performed, as shown in Figure 12.

[0129] The melting process involves melting the peripheral wall 410 at a first predetermined temperature (melting temperature) Tm, and then airtightly joining the first glass plate 20 and the second glass plate 30 with the molten peripheral wall 410. Specifically, the assembly 101 is placed in a firing furnace. The assembly 101 is then heated at the melting temperature Tm for a first predetermined time (melting time) tm (see Figure 12). In the melting process, the weir member 47 is also melted, and the molten weir member 47 airtightly joins the first glass plate 20 and the second glass plate 30. The melting temperature Tm is selected to be above the softening point of the sealant. The melting temperature Tm is preferably 500°C or less, more preferably 350°C or less, and even more preferably 300°C or less. Furthermore, if at least one of the first glass plate 20 and the second glass plate 30 includes tempered glass, the melting temperature Tm is preferably selected to be 300°C or lower. The softening point of the sealant is, for example, 265°C. The melting time tm can be arbitrarily selected, for example, depending on the size of the first and second glass plates 20 and 30 and the size of the peripheral wall 410.

[0130] Furthermore, in this embodiment, after the melting process, the temperature inside the firing furnace is lowered in order to perform the sealing process. As a result, the peripheral wall 410 hardens to become the frame 40, and the weir member 47 hardens. This yields the work-in-progress 111.

[0131] The exhaust process is a process of exhausting the internal space 500 through the exhaust port 700 to create a vacuum space 50. Exhaust is performed, for example, using a vacuum pump. The vacuum pump is connected to the work-in-progress 111 by a depressurization mechanism 71, as shown in Figure 13. The depressurization mechanism 71 comprises an exhaust head 75, a connecting part 753, and a pressing mechanism 73. The connecting part 753 connects the exhaust head 75 to the vacuum pump. The exhaust head 75 is pressed against the work-in-progress 111 so as to connect its interior to the internal space 500 through the exhaust port 700. Specifically, the exhaust head 75 is airtightly pressed against the portion of the first glass plate 20 surrounding the opening of the exhaust port 700. When the air inside the exhaust head 75 is drawn in through the connecting part 753 (see the white arrow in Figure 13), the internal space 500 is exhausted through the exhaust port 700. The pressing mechanism 73 is located inside the exhaust head 75. The pressing mechanism 73 is configured to push the hole sealing material 43 inserted into the exhaust port 700 toward the second glass plate 30 while the vacuum space 50 is maintained by the depressurization mechanism 71. During the exhaust process, the hole sealing material 43 and plate 46, which have a diameter smaller than the inner diameter of the exhaust port 700, are inserted into the exhaust port 700 (see Figure 13). The plate 46 is interposed between the hole sealing material 43 and the pressing mechanism 73. In this state, the hole sealing material 43 and plate 46 are elastically pushed toward the second glass plate 30 by the pressing mechanism 73.

[0132] The pore sealing material 43 is a solid sealing material formed using, for example, glass frit. The pore sealing material 43 has a block-like shape, but it is also preferable that it has a cylindrical shape with holes running through it vertically. In addition to glass frit, the pore sealing material 43 may further contain an organic binder similar to that of the peripheral wall 410. In this case, even if gas is released into the vacuum space 50 from the pore sealing material 43 after the sealing process, the gas adsorbent 60 will adsorb this gas, making it less likely for gas to remain in the vacuum space 50.

[0133] In this embodiment, the exhaust process is started midway through the melting process, as shown in Figure 12. Therefore, even during the melting process, the internal space 500 is exhausted through the exhaust port 700. As a result, a pressure difference is created inside and outside the assembly 101 during the melting process, and this pressure difference causes the first and second glass plates 20 and 30 to move closer to each other. This makes it easier to airtightly join the first glass plate 20 and the second glass plate 30 by the peripheral wall 410, even if the first and second glass plates 20 and 30 are warped. In addition, by starting the exhaust process midway through the melting process, unwanted gases released from the peripheral wall 410 and the weir member 47 during the melting process are exhausted. Therefore, it is possible to prevent unwanted gases originating from the peripheral wall 410 and the weir member 47 from remaining in the vacuum space 50 as shown in Figure 9B.

[0134] The sealing process involves locally heating and melting a hole sealing material 43 inserted into the exhaust port 700, and then sealing the exhaust port 700 with the melted hole sealing material 43. During the sealing process, the exhaust process continues as shown in Figure 12. The temperature during the sealing process is maintained at a second predetermined temperature (sealing temperature) Ts, which is lower than or equal to the melting temperature Tm of the melting process. Specifically, the temperature during the sealing process is maintained at a sealing temperature Ts that is lower than the melting temperature Tm. In the sealing process, only the hole sealing material 43 is locally heated and melted at a temperature higher than the sealing temperature Ts. The sealing temperature Ts is, for example, 250°C. In addition, the hole sealing material 43 is locally heated for a second predetermined time (sealing time) ts during the sealing process. The sealing time ts is arbitrarily selected according to the size of the hole sealing material 43. In essence, the sealing process in this embodiment is a process of spatially separating the vacuum space 50 from the space other than the vacuum space 50. In this embodiment, the space other than the vacuum space 50 corresponds to the space outside the work-in-progress 111.

[0135] In this embodiment, the sealing process is performed using a heating mechanism 72, as shown in Figure 14. The heating mechanism 72 is positioned on the opposite side of the work-in-progress 111 from the exhaust head 75. The heating mechanism 72 is configured to heat the hole sealing material 43 inserted into the exhaust port 700 without contact. In this case, since the hole sealing material 43 is locally heated by the heating mechanism 72, the temperature of the work-in-progress 111 is maintained at the sealing temperature Ts.

[0136] The heating mechanism 72 includes an irradiator 720. The irradiator 720 is configured to heat the hole sealing material 43 by irradiating it with infrared (near-infrared) light through the second glass plate 30.

[0137] During the sealing process, by operating both the heating mechanism 72 and the pressing mechanism 73, the vacuum space 50 is maintained while the exhaust port 700 is sealed with the hole sealing material 43. In this case, the hole sealing material 43 is melted, and the molten hole sealing material 43 is retained in the space on the inner circumference side of the weir member 47. Subsequently, the exhaust port 700 is sealed as the molten hole sealing material 43 hardens.

[0138] In other words, during the sealing process, the sealing material 43 is heated and melted by the heating mechanism 72, and the sealing material 43 is pressed toward the second glass plate 30 by the biasing force exerted by the pressing mechanism 73 via the plate 46. The sealing material 43 deforms within the vacuum space 50 until it contacts the inner circumferential surface of the weir member 47. The notched portion provided in the weir member 47 is sealed by the deformed sealing material 43.

[0139] By sealing the exhaust port 700, the vacuum space 50 can be maintained even when the exhaust head 75 is removed. When removing the exhaust head 75, the molten hole sealing material 43 is hardened by heat removal. After sealing the exhaust port 700 with the hole sealing material 43, the exhaust process is stopped. This results in a glass panel unit 10A as shown in Figures 9A and 9B.

[0140] <Applications of composite getter materials> In the above description, examples were given in which the composite getter material was used in the glass panel units 10 and 10A of the first and second embodiments, respectively. However, the composite getter material of this disclosure can also be used in electronic devices such as MEMS devices and displays. Of course, getter paste containing the composite getter material can also be used in electronic devices such as MEMS devices and displays.

[0141] <Third Embodiment> The manufacturing method of the glass panel unit 10 according to this embodiment differs from that of the first embodiment in the getter paste manufacturing step and the configuration of the gas adsorbent. In the following, components that overlap with those of the first embodiment may be denoted by the same reference numerals in the drawings and their descriptions may be omitted.

[0142] In this embodiment, in the getter paste manufacturing process, the zeolite particles, which are the first getter material, and the cerium compound, which is the second getter material, are obtained separately without mixing. That is, in the first embodiment, the composite getter material manufacturing process produces a composite getter containing both zeolite particles and cerium compound particles, but in this embodiment, the getter paste manufacturing process includes forming a first getter paste containing zeolite particles and a second getter paste containing cerium compound separately. That is, the first getter paste does not contain the second getter material (cerium compound particles). The second getter paste does not contain the first getter material (zeolite particles).

[0143] Furthermore, in this embodiment, instead of the gas adsorbent 60 in the first embodiment, a first gas adsorbent 61 and a second gas adsorbent 62 are provided, as shown in Figures 15A and 15B. The first gas adsorbent 61 contains a first getter material; that is, the first gas adsorbent 61 contains zeolite particles. The second gas adsorbent 62 contains a second getter material; that is, the second gas adsorbent 62 contains cerium compound particles.

[0144] In Figure 15A, the second gas adsorbent 62 is formed on the second end side in the longitudinal direction of the second glass plate 300 (the left end side in Figure 15A), along the width direction (direction D2) of the second glass plate 300. The first gas adsorbent 61 is formed on one end side in the width direction of the second glass plate 300, along the longitudinal direction (direction D3) of the second glass plate 300. If the first and second glass plates 200 and 300 are rectangles where direction D3 is longer than direction D2, the first gas adsorbent 61 is formed to be longer than the second gas adsorbent 62. As a result, more zeolite than cerium compound is arranged in the internal space 500.

[0145] In Figure 15B, both the first gas adsorbent 61 and the second gas adsorbent 62 are formed along the width direction (direction D2) of the second glass plate 300, on the second end side in the longitudinal direction of the second glass plate 300 (the left end side in Figure 15B). That is, the first gas adsorbent 61 and the second gas adsorbent 62 are arranged in parallel. This may improve the design of the glass panel unit 10. The first gas adsorbent 61 and the second gas adsorbent 62 are not limited to those shown in Figures 15A and 15B, and may be formed in any shape or position.

[0146] In this embodiment, the glass panel unit 10 is manufactured in the same manner as in the first embodiment, except for the fourth step in the mixing and assembly processes.

[0147] In this embodiment, a getter paste is obtained by mixing a getter material and a solvent in a mixing step. In this case, a first getter paste is obtained by mixing a first getter material and a solvent, and a second getter paste is obtained by mixing a second getter material and a solvent. The solvent for the first getter paste and the solvent for the second getter paste may be of the same type or may be of different types.

[0148] In this embodiment, similar to the first embodiment, the first gas adsorbent 61 and the second gas adsorbent 62 are formed in the fourth step of the assembly process. In this case, the first getter paste and the second getter paste are applied to the second glass plate 300, respectively, using a dispenser or the like. The first gas adsorbent 61 and the second gas adsorbent 62 are then formed by drying the applied getter paste.

[0149] As in the first embodiment, forming a gas adsorbent 60 containing zeolite and a cerium compound, while forming a first gas adsorbent 61 containing zeolite and a second gas adsorbent 62 containing a cerium compound separately, as in this embodiment, makes the zeolite (especially Cu-ZSM5) less susceptible to oxygen desorption from the cerium compound (especially CeO2). Therefore, a high adsorption capacity can sometimes be obtained with the first gas adsorbent 61.

[0150] <Fourth Embodiment> The manufacturing method of the glass panel unit 10 according to this embodiment differs from that of the first embodiment in the getter material manufacturing process and the configuration of the gas adsorbent. In the following, components that overlap with those of the first embodiment may be denoted by the same reference numerals in the drawings and their descriptions may be omitted.

[0151] In this embodiment, in the getter paste manufacturing process, a first getter paste containing particles made of copper ion exchange zeolite, which is the first getter material, and a second getter paste containing particles made of a cerium compound, which is the second getter material, are obtained. That is, in the first embodiment, the composite getter material contains both zeolite particles and cerium compound particles, but in this embodiment, the first getter paste containing copper ion exchange zeolite particles and the second getter paste containing cerium compound particles are formed separately. That is, the first getter paste does not contain the second getter material (cerium compound particles). The second getter paste does not contain the first getter material (copper ion exchange zeolite particles).

[0152] Furthermore, in this embodiment, the gas adsorbent 60 in the first embodiment comprises a first gas adsorbent 601 and a second gas adsorbent 602, as shown in Figure 16. The first gas adsorbent 601 contains a first getter material; that is, the first gas adsorbent 601 contains copper ion exchange zeolite particles. The second gas adsorbent 602 contains a second getter material; that is, the second gas adsorbent 602 contains cerium compound particles.

[0153] In this embodiment, the gas adsorbent 60 has at least two types of getter materials (a first getter material and a second getter material). The two types of getter materials each contain copper ion exchange zeolite particles and cerium compound particles. That is, the first getter material contains copper ion exchange zeolite particles, and the second getter material contains cerium compound particles. The first gas adsorbent 601 and the second gas adsorbent 602 are arranged separately in the vacuum space 50. As a result, the first gas adsorbent 601 and the second gas adsorbent 602 are located in different positions.

[0154] Here, the state in which the first gas adsorbent 601 and the second gas adsorbent 602 are arranged separately includes the case in which the first gas adsorbent 601 and the second gas adsorbent 602 are in contact with each other's surfaces. In this case, the first gas adsorbent 601 and the second gas adsorbent 602 may be in contact over their entire surfaces, or only some of their surfaces may be in contact. For example, when the first gas adsorbent 601 and the second gas adsorbent 602 are arranged in an overlapping state, the positions of the first gas adsorbent 601 and the second gas adsorbent 602 are different in the direction perpendicular to the first glass plate 200 and the second glass plate 300 (direction D1). Therefore, the copper ion exchange zeolite powder and the cerium compound particles are in contact only at the boundary between the first gas adsorbent 601 and the second gas adsorbent 602, and are therefore included in the state of being arranged separately.

[0155] Furthermore, the first gas adsorbent 601 and the second gas adsorbent 602 may be placed separately. The state in which the first gas adsorbent 601 and the second gas adsorbent 602 are placed separately means that the first gas adsorbent 601 and the second gas adsorbent 602 are placed in a state where they are not in contact with each other. For example, if either the first gas adsorbent 601 or the second gas adsorbent 602 is placed on the first glass plate 200 and the other is placed on the second glass plate 300, and the first gas adsorbent 601 and the second gas adsorbent 602 appear to overlap when viewed from a direction perpendicular to the first glass plate 200 or the second glass plate 300 (direction D1 in Figure 16), then this is also included in the state of being placed separately because their positions perpendicular to the first glass plate 200 and the second glass plate 300 (direction D1) are different.

[0156] However, it is more desirable to arrange the copper ion-exchange zeolite particles and cerium compound particles in a way that minimizes contact between them, as this reduces the effect of oxygen desorption from the cerium compound particles.

[0157] In Figure 16, the first gas adsorbent 601 is formed on the second end side in the longitudinal direction of the second glass plate 300 (the left end side in Figure 16), along the width direction (direction D2) of the second glass plate 300. Multiple second gas adsorbents 602 are formed in a point-like manner. That is, multiple point-like second gas adsorbents 602 are formed over the entire surface of the second glass plate 300 (the surface facing the first space 510). Each second gas adsorbent 602 is formed to be smaller than the spacer 70. Furthermore, the multiple second gas adsorbents 602 are arranged apart from the spacer 70 and the first gas adsorbent 601. That is, the multiple second gas adsorbents 602 are arranged between adjacent spacers 70, or between the spacer 70 and the first gas adsorbent 601.

[0158] In this embodiment, the glass panel unit 10 is manufactured in the same manner as in the first embodiment, except for the fourth step in the mixing and assembly processes.

[0159] In this embodiment, the first gas adsorbent 601 is formed from a first getter paste. The first getter paste is obtained by mixing a getter material and a solvent in a mixing step, similar to the first embodiment. In this case, the first getter material and the solvent are mixed. On the other hand, the second gas adsorbent 602 is composed of a powder containing a getter material. That is, the second gas adsorbent 602 is composed of a powder containing a plurality of cerium compound particles. The second gas adsorbent 602 can be formed from, for example, cerium oxide powder. An example of cerium oxide powder is cerium oxide nanopowder manufactured by Strem Chemicals, Inc. (a commercially available product, model 50-1400, similar to that used in manufacturing examples 18 and 19 described later). This cerium oxide powder is an aggregate of nanoparticles (particle size 1 to 100 nm) as cerium oxide compound particles. By using cerium oxide nanopowder as the second gas adsorbent 602, it becomes less visible when the second gas adsorbent 602 is scattered, and the transparency of the glass panel unit 10 is less likely to be impaired. In addition, the second gas adsorbent 602 composed of nanopowder can have a larger surface area compared to the second gas adsorbent 602 composed of large chunks (bulk). Therefore, even without a supporting material for the nanopowder, the adsorption capacity of the second gas adsorbent 602 can be increased.

[0160] In this embodiment, as in the first embodiment, the first gas adsorbent 601 and the second gas adsorbent 602 are formed in the fourth step of the assembly process. In this case, the second gas adsorbent 602 is formed by scattering nanopowder of cerium oxide particles over the entire surface of the second glass plate 300. The first gas adsorbent 601 is formed by applying the first getter paste onto the second glass plate 300 using a dispenser or the like, and then drying the applied first getter paste.

[0161] In the first, second, and third embodiments, the gas adsorbent 60 is formed near the outer periphery of the second glass plate 300. Therefore, the amount of getter paste that can be applied is limited, and it may be difficult to form a large gas adsorbent 60. On the other hand, in this embodiment, when the second gas adsorbent 602 is formed using only cerium oxide nanopowder, the second gas adsorbent 602 can be formed even in a narrow space by scattering the cerium oxide nanopowder over the entire surface of the second glass plate 300. Therefore, space can be utilized efficiently.

[0162] Furthermore, since zeolite particles change color when they adsorb gas, the discoloration of the first gas adsorbent 601 containing zeolite particles makes it easier to check the vacuum level inside the glass panel unit 10 (vacuum space 50). On the other hand, when zeolite particles and cerium oxide particles are mixed to form the gas adsorbent 60, it becomes difficult to check the color change of the gas adsorbent 60. In this embodiment, since copper ion exchange zeolite particles and cerium compound particles are arranged separately, the color change of the copper ion exchange zeolite particles can be checked, making it easier to check the vacuum level of the vacuum space 50.

[0163] Furthermore, in this embodiment, since the first gas adsorbent 601 containing zeolite particles and the second gas adsorbent 602 containing cerium compound particles are formed separately, the zeolite (especially Cu-ZSM5) particles are less susceptible to oxygen desorption from the cerium compound (especially CeO2) particles. Therefore, a high adsorption capacity can sometimes be obtained by the first gas adsorbent 61. [Examples]

[0164] The present disclosure will be specifically described below with reference to examples.

[0165] <Analysis of Cerium(IV) Oxide> Unheated cerium(IV) oxide powder was placed in a chamber. After this, the chamber was evacuated to create a vacuum. Then, the temperature inside the chamber was increased at a heating rate of 30°C / min, and the amount of oxygen desorbed from the cerium(IV) oxide powder at each temperature was quantified using a temperature-controlled desorption gas analysis method. The results are shown as an oxygen release curve in Figure 17. The "intensity" on the vertical axis of Figure 17 represents the common logarithm of the oxygen detection intensity (oxygen ion current value). From the results in Figure 17, it was found that a large amount of oxygen is desorbed from the cerium(IV) oxide powder at temperatures above 200°C.

[0166] <Manufacturing example A> Manufacturing Example A of this disclosure will be explained in Manufacturing Examples 1 to 6 below.

[0167] <<Manufacturing Examples 1-6>> Each manufacturing example was carried out using the components shown below. • First glass plate (glass plate size: width x length x thickness = 300mm x 300mm x 3mm, Low-E glass emissivity = 0.04), • Second glass plate (glass plate size: width x length x thickness = 300mm x 300mm x 3mm), • Spacer (size: diameter x height = 0.5mm x 0.1mm, made of resin) • Glass frit; vanadium-based glass frit (softening point: 265°C).

[0168] [Manufacturing Example 1] First, a composite getter material was prepared by mixing cerium(IV) oxide powder (2 parts by mass) and copper ion exchange zeolite (Cu-ZSM5) powder (98 parts by mass). Then, a getter paste was prepared by uniformly mixing 100 parts by mass of the composite getter material with 400 parts by mass of water. Next, the getter paste was applied to one surface of the second glass plate having an exhaust port using a spatula, with an amount of 50 mg of the composite getter material. After this application, the getter paste on the second glass plate was dried to prepare a gas adsorbent. After the preparation of the gas adsorbent, a peripheral wall made of a sealing material, a partition made of a sealing material, a ventilation passage, and multiple spacers were further formed on one surface of the second glass plate. When forming the peripheral wall and partition, a sealing material was prepared by mixing 88 parts by mass of glass frit, 2 parts by mass of organic binder, and 10 parts by mass of organic solvent. This sealing material was applied to the second glass plate and then dried. When preparing the sealing material, aliphatic polycarbonate was used as the organic binder and ethyl acetate carbitol as the organic solvent. Furthermore, when forming the spacers, multiple spacers were placed on the second glass plate using a chip mounter, with a spacing of 20 mm between adjacent spacers.

[0169] Next, the first glass plate was positioned opposite the second glass plate. This resulted in an assembly in which an internal space was formed between the first and second glass plates.

[0170] Next, the vacuum pump and exhaust port were connected using an exhaust pipe and a seal head, and then the assembled product was placed inside the melting furnace. After this placement, the assembled product was heated at 285°C (first melting temperature) for 15 minutes to melt the surrounding walls. The ventilation passage was not blocked during this melting process.

[0171] After the surrounding walls melted, the temperature inside the melting furnace was lowered to the exhaust temperature of 250°C. Then, by operating a vacuum pump, the internal space was evacuated at 250°C for 120 minutes.

[0172] Subsequently, with the vacuum pump still running, the temperature inside the melting furnace was raised to the second melting temperature of 290°C, and the assembled product was heated at this temperature for 15 minutes. This heating deformed the partition, forming a partition wall that blocked the ventilation passage.

[0173] After forming the partition wall, the temperature inside the melting furnace was lowered to room temperature. After this cooling, the vacuum pump was stopped and the seal head was removed. After removing the seal head, the glass panel unit was fabricated by removing the unnecessary parts through cutting.

[0174] [Manufacturing Example 2] A glass panel unit was fabricated in the same manner as in Manufacturing Example 1, except that cerium(IV) oxide powder (10 parts by mass) and copper ion exchange zeolite (Cu-ZSM5) powder (90 parts by mass) were used.

[0175] [Manufacturing Example 3] A glass panel unit was fabricated in the same manner as in Manufacturing Example 1, except that cerium(IV) oxide powder (20 parts by mass) and copper ion exchange zeolite (Cu-ZSM5) powder (80 parts by mass) were used.

[0176] [Manufacturing Example 4] A glass panel unit was fabricated in the same manner as in Manufacturing Example 1, except that cerium(IV) oxide powder (50 parts by mass) and the heat-treated product of copper ion exchange zeolite (Cu-ZSM5) powder preparation example 2 (50 parts by mass) were used.

[0177] [Manufacturing Example 5] A glass panel unit was fabricated in the same manner as in Manufacturing Example 1, except that the amount of cerium(IV) oxide powder was 100 parts by mass and copper ion exchange zeolite (Cu-ZSM5) powder was not used.

[0178] [Manufacturing Example 6] A glass panel unit was fabricated in the same manner as in Manufacturing Example 1, except that the amount of copper ion exchange zeolite (Cu-ZSM5) powder was 100 parts by mass and cerium(IV) oxide powder was not used.

[0179] {evaluation} <Thermal conductance> The thermal conductance of the glass panel units in each manufacturing example was evaluated using the following procedure. With the high-temperature and low-temperature sections of the measuring device separated by the glass panel unit, a first thermometer was placed on the outer surface of the first glass plate, and a second thermometer and sensor were placed on the outer surface of the second glass plate. After this arrangement, the heat flux transmitted from the heating section to the cooling section via the glass panel unit was detected by the sensor, the surface temperature of the first glass plate was measured with the first thermometer, and the surface temperature of the second glass plate was measured with the second thermometer.

[0180] Then, the thermal conductance of the glass panel unit was calculated by introducing the heat flux, the surface temperature of the first glass plate, and the surface temperature of the second glass plate into the following equation (1). Q = C(T1 - T2) ... (1) In equation (1), Q is the heat flux (W / m 2 ) indicates the surface temperature (K) of the first glass plate, T1 indicates the surface temperature (K) of the second glass plate, and C indicates the thermal conductance (W / m²). 2 This indicates K).

[0181] Figure 18A shows the relationship between the thermal conductance of each production example and the amount of cerium(IV) oxide (CeO2) added. From the results in Figure 18A, it was found that the thermal conductance of production examples 1-4 tended to be lower than that of production examples 5-6. From this trend, it was considered that in a vacuum, CeO2 adsorbs carbon dioxide, and the copper ion exchange zeolite adsorbs not only oxygen desorbed from CeO2 but also gases such as nitrogen and methane. Therefore, it was considered that using copper ion exchange zeolite and CeO2 together makes it less likely for gases to remain in the vacuum.

[0182] Furthermore, the results in Figure 18A showed that the thermal conductance tended to decrease with the addition of CeO2, and that the thermal conductance tended to decrease as the amount of CeO2 added decreased. These trends suggest that the amount of oxygen detached from CeO2 can be reduced, and that less gas remains in the vacuum space.

[0183] Here, we will explain the case where hydrogen ion exchange zeolite (HZSM-5) is used instead of copper ion exchange zeolite. Hydrogen ion exchange zeolite is ZSM-5 type zeolite that has undergone hydrogen ion exchange. Therefore, hydrogen ion exchange zeolite is a component in which hydrogen ions are retained in the zeolite structure.

[0184] Figure 18B, similar to Figure 18A, is a graph showing the relationship between the amount of CeO2 added to the composite getter material and the thermal conductance of the glass panel unit. The glass panel unit that yields the results shown in Figure 18B is fabricated using hydrogen ion exchange zeolite instead of copper ion exchange zeolite in the composite getter material.

[0185] In comparative manufacturing example 2, a glass panel unit was fabricated in the same manner as in manufacturing example 1, except that cerium(IV) oxide powder (10 parts by mass) and hydrogen ion exchange zeolite (HZSM-5) powder (90 parts by mass) were used.

[0186] Comparative Manufacturing Example 4 was manufactured in the same manner as Manufacturing Example 1, except that cerium(IV) oxide powder (50 parts by mass) and hydrogen ion exchange zeolite (HZSM-5) powder (50 parts by mass) were used in Manufacturing Example 4.

[0187] Comparative Manufacturing Example 5 was prepared in the same manner as Manufacturing Example 1, except that the amount of cerium(IV) oxide powder was 100 parts by mass, and hydrogen ion exchange zeolite (HZSM-5) powder was not used.

[0188] Comparative Manufacturing Example 6 was prepared in the same manner as Manufacturing Example 1, except that the amount of hydrogen ion exchange zeolite (HZSM-5) powder was 100 parts by mass and cerium(IV) oxide powder was not used.

[0189] Comparing Figure 18A and Figure 18B, Figure 18A shows a minimum value of thermal conductance near the amount of CeO2 added in the plots for manufacturing examples 1-4. On the other hand, Figure 18B does not show a minimum value of thermal conductance near the amount of CeO2 added in the plots for comparative manufacturing examples 2 and 4.

[0190] In other words, a getter material using a mixture of copper ion exchange zeolite and CeO2 exhibits a unique effect compared to a getter material using a mixture of hydrogen ion exchange zeolite and CeO2. Specifically, a getter material containing copper ion exchange zeolite and CeO2 yields a glass panel unit with lower thermal conductance even with a smaller amount of CeO2 added compared to a getter material containing hydrogen ion exchange zeolite and CeO2.

[0191] <Manufacturing example B> The process is the same as in Production Example A, except that the cerium(IV) oxide powder and copper ion exchange zeolite powder were treated as in Preparation Example 1 and Preparation Example 2 below before mixing.

[0192] [Adjustment Example 1] 0.2 g of unheated copper ion exchange zeolite powder was placed in a chamber. After placement, the chamber was evacuated to create a vacuum, and the copper ion exchange zeolite powder was heated at 500°C for 4 hours. This desorbed the components adsorbed by the unheated copper ion exchange zeolite powder. Subsequently, the chamber was cooled to room temperature. After cooling, nitrogen gas was introduced into the chamber to bring the pressure inside the chamber to atmospheric pressure. This yielded a heat-treated copper ion exchange zeolite powder.

[0193] [Adjustment Example 2] 0.1 g of cerium(IV) oxide powder (unheated) was placed in a chamber. After placement, the chamber was evacuated to create a vacuum, and the cerium(IV) oxide powder was heated at 500°C for 2 hours. This removed oxygen from the cerium(IV) oxide powder. The chamber was then cooled to room temperature. After cooling, carbon dioxide gas was introduced into the chamber to bring the pressure inside the chamber to atmospheric pressure. This yielded a heat-treated product of cerium(IV) oxide powder.

[0194] By pre-heat-treating the zeolite powder or cerium(IV) oxide powder in this manner, the adsorption capacity of the composite getter material was improved and the amount of oxygen desorption from the cerium oxide powder was reduced, resulting in a composite getter material with higher adsorption performance.

[0195] <Manufacturing example C> In manufacturing examples 7-13, the total amount of cerium(IV) oxide powder and copper ion exchange zeolite powder (the "amount of getter material" in manufacturing example A) was changed to 20 mg. Furthermore, in manufacturing examples 10-13, the cerium(IV) oxide and copper ion exchange zeolite powder were not mixed before coating, but were placed in separate, distant locations within the same vacuum space. Other than these changes, the process was the same as in manufacturing example A.

[0196] [Manufacturing Example 7] A glass panel unit was prepared in the same manner as in Manufacturing Example 1, except that cerium(IV) oxide powder (10 parts by mass) and copper ion exchange zeolite (Cu-ZSM5) powder (90 parts by mass) were used, with a total amount of 20 mg.

[0197] [Manufacturing Example 8] A glass panel unit was fabricated in the same manner as in Manufacturing Example 7, except that cerium(IV) oxide powder (15 parts by mass) and copper ion exchange zeolite (Cu-ZSM5) powder (85 parts by mass) were used.

[0198] [Manufacturing Example 9] A glass panel unit was fabricated in the same manner as in Manufacturing Example 7, except that cerium(IV) oxide powder (25 parts by mass) and copper ion exchange zeolite (Cu-ZSM5) powder (75 parts by mass) were used.

[0199] [Manufacturing Example 10] Using cerium(IV) oxide powder (10 parts by mass) and copper ion exchange zeolite (Cu-ZSM5) powder (90 parts by mass), a total of 20 mg was prepared. Two types of getter pastes were created by mixing the cerium(IV) oxide powder with water (40 parts by mass) and the copper ion exchange zeolite powder with water (360 parts by mass). Glass panel units were fabricated in the same manner as in Manufacturing Example 1, except that each getter paste was applied to different positions within the same vacuum space.

[0200] [Manufacturing Example 11] A glass panel unit was fabricated in the same manner as in Manufacturing Example 10, except that cerium(IV) oxide powder (15 parts by mass) and copper ion exchange zeolite (Cu-ZSM5) powder (85 parts by mass) were used.

[0201] [Manufacturing Example 12] A glass panel unit was fabricated in the same manner as in Manufacturing Example 10, except that cerium(IV) oxide powder (25 parts by mass) and copper ion exchange zeolite (Cu-ZSM5) powder (75 parts by mass) were used.

[0202] [Manufacturing Example 13] A glass panel unit was fabricated in the same manner as in Manufacturing Example 10, except that cerium(IV) oxide powder (50 parts by mass) and copper ion exchange zeolite (Cu-ZSM5) powder (50 parts by mass) were used.

[0203] {evaluation} <Thermal conductance> The thermal conductance was measured using the same method as in manufacturing example A. The results are shown in Figure 19.

[0204] In manufacturing examples 7, 8, and 9, the thermal conductance increases with increasing cerium oxide concentration between 10 wt% and 25 wt%. On the other hand, in manufacturing examples 10, 11, and 12, the thermal conductance decreases with increasing cerium oxide concentration between 10 wt% and 25 wt%. This is thought to be because the effect of oxygen desorbed from CeO2 on Cu-ZSM5 was suppressed.

[0205] Furthermore, as shown in manufacturing example 13, the thermal conductance increases even when the cerium oxide concentration reaches 50 wt%, even in the case of separate coating. This is thought to be because, although the cerium oxide and copper ion exchange zeolite are coated separately, the cerium oxide and copper ion exchange zeolite are in the same vacuum space, causing Cu-ZSM5 to be affected by oxygen desorption from CeO2. In addition, it is thought that increasing the CeO2 concentration reduces the amount of Cu-ZSM5 that can adsorb nitrogen and methane, which are normally difficult to adsorb.

[0206] For 20 mg of Cu-ZSM5 alone, the thermal conductance value is 20 W / m². 2 The temperature will be around K. Therefore, it can be seen that the effect of mixing CeO2 is significant even in mixed coating. Separate coating has the great advantage of being less affected by oxygen desorbed from CeO2, but it also has disadvantages such as a longer coating process time and the gas adsorbent being more visible. For this reason, the more desirable option between mixed coating and separate coating should be selected after considering the manufacturing process and product characteristics.

[0207] <Manufacturing example D> The process is the same as in Production Example 8, except that cerium(IV) oxide powders with different reduction temperatures are used and the mixing ratio of cerium oxide powders differs. Production Examples 14 and 15 use metal-supported cerium(IV) oxide powder. Production Examples 16 and 17 use cerium(IV) oxide powder with a lower concentration of metal-supported material than in Production Examples 14 and 15. Production Examples 18 and 19 use cerium(IV) oxide powder without metal support.

[0208] [Manufacturing Example 14] A glass panel unit was fabricated in the same manner as in Manufacturing Example 7, except that cerium(IV) oxide powder (15 parts by mass) with a reduction temperature of 200°C was used.

[0209] [Manufacturing Example 15] A glass panel unit was prepared in the same manner as in Manufacturing Example 14, except that cerium(IV) oxide powder (50 parts by mass) with a reduction temperature of 200°C and copper ion exchange zeolite (Cu-ZSM5) powder (85 parts by mass) were used, totaling 27 mg.

[0210] [Manufacturing Example 16] A glass panel unit was fabricated in the same manner as in Manufacturing Example 14, except that cerium(IV) oxide powder (15 parts by mass) with a reduction temperature of 550°C was used.

[0211] [Manufacturing Example 17] A glass panel unit was fabricated in the same manner as in Manufacturing Example 15, except that cerium(IV) oxide powder (50 parts by mass) with a reduction temperature of 550°C was used.

[0212] [Manufacturing Example 18] A glass panel unit was fabricated in the same manner as in Manufacturing Example 14, except that cerium(IV) oxide powder (15 parts by mass) with a reduction temperature exceeding 650°C was used.

[0213] [Manufacturing Example 19] A glass panel unit was fabricated in the same manner as in Manufacturing Example 15, except that cerium(IV) oxide powder (50 parts by mass) with a reduction temperature exceeding 650°C was used.

[0214] {evaluation} <Reduction temperature> The reduction temperature was determined by examining the onset of oxygen release using a temperature-controlled desorption gas analysis. Under ultra-high vacuum, the heating rate was set to 30°C / min, and measurements were taken until the sample temperature reached 650°C. The sample temperature was measured by placing the sample between 1 cm diameter carbon sheets, heating it from below with infrared light, and applying a thermocouple from above the carbon sheets. The measurement results are shown as an oxygen release curve in Figure 20. The O2 release amount was measured using a temperature-controlled desorption analyzer TDS1200II manufactured by Denshi Kagaku Co., Ltd. The vertical axis of the graph in Figure 20 shows the O2 ion current value at each temperature, as the O2 release amount per unit time. The maximum value on the vertical axis is 8E-10[A].

[0215] <Cerium oxide increase test> For each manufacturing example, the thermal conductance was measured using the same method as in manufacturing example A. Figure 21 shows the ratio of thermal conductances, with the thermal conductance when 15 parts by mass of cerium oxide powder was used set to 1.

[0216] In the case of cerium oxide powder with a reduction temperature of 200°C, increasing the amount of cerium oxide increases the thermal conductance. Furthermore, in the case of cerium oxide powder with a reduction temperature of 550°C, increasing the amount of cerium oxide results in almost no change in thermal conductance, although there is a slight increase. On the other hand, in the case of cerium oxide powder with a reduction temperature exceeding 650°C, the thermal conductance value decreases. This is related to the fact that copper oxide in Cu-ZSM5 begins to release oxygen at around 250°C, and the reduced copper ion sites adsorb poorly adsorbed gases such as nitrogen and methane.

[0217] In the cerium oxide powders of manufacturing examples 14 and 15, where reduction begins at 200°C, oxygen is released from 200°C, significantly inhibiting the reduction of copper oxide in Cu-ZSM5. In the case of cerium oxide powder that is reduced at 550°C, there is almost no oxygen released at 250°C when it is alone, but the reducing action of Cu-ZSM5 releases a small amount of oxygen, which also slightly inhibits the reduction of copper oxide in Cu-ZSM5. In the case of cerium oxide that is not reduced even at temperatures above 650°C, the energy required to desorb oxygen is high, so it is not reduced even when mixed with Cu-ZSM5 and does not adversely affect Cu-ZSM5. As a result, increasing the amount of cerium oxide can increase the amount of CO2 adsorbed, preventing the adsorption sites of Cu-ZSM5 from being filled with CO2, and thus maintaining a high amount of nitrogen and methane adsorption. For this reason, in order to avoid adversely affecting Cu-ZSM5, a reduction temperature of 250°C or higher is desirable, and moreover, 550°C or higher is particularly desirable.

[0218] In Figure 20, the oxygen release initiation temperature (the temperature at which reduction begins) is the temperature at which the oxygen release curve rises (the slope becomes positive). The peak (maximum point) below 200°C is thought to be due to trace amounts of oxygen release by physical adsorption. Furthermore, the slope of the oxygen release curve is negative at 250°C (or 300°C, 500°C, and 550°C). Therefore, oxygen release initiation temperatures of 300°C or higher, 500°C or higher, and 550°C or higher are more desirable.

[0219] There are three main reasons why cerium oxide is useful because it does not adversely affect Cu-ZSM5.

[0220] The first advantage is that it does not degrade the adsorption capacity of Cu-ZSM5, thus tending to increase the overall adsorption capacity. For example, the thermal conductance of production example 15 using cerium oxide powder at a reduction temperature of 200°C is 3.8 W / m². 2 The value is K. The thermal conductance of production example 17 using cerium oxide powder at a reduction temperature of 550°C is 1.3 W / m². 2 The value is K. The thermal conductance of production example 19 using cerium oxide powder with a reduction temperature of 650°C or higher is 1.0 W / m². 2 It is K.

[0221] The second advantage is that the precision requirements for cerium oxide concentration are relaxed. In cases where a slightly higher cerium oxide concentration significantly worsens the thermal conductance, precision is required in concentration adjustment.

[0222] The third advantage is the ability to freely design the CO2 adsorption capacity. For example, when vacuum-insulated glass is irradiated with ultraviolet light, a large amount of CO2 may be released. If the amount of cerium oxide powder can be increased in anticipation of this, the total amount of gas adsorbent does not need to be increased significantly. On the other hand, if cerium oxide is negatively affecting Cu-ZSM5, the concentration cannot be increased, so both cerium oxide and Cu-ZSM5 must be increased in the same ratio, which may unnecessarily increase the total amount of gas adsorbent.

[0223] The reduction temperature of cerium oxide powder is affected by the type and amount of additives, pore size distribution, and particle size. Generally, the carbon dioxide adsorption capacity of cerium oxide powder increases with the addition of metals or rare earth elements, and with finer pore size distribution, but conversely, the reduction temperature tends to decrease. Therefore, it is desirable to appropriately adjust the carbon dioxide adsorption capacity so that the reduction temperature is 250°C or higher.

[0224] Furthermore, only a trace amount of cerium oxide powder with a reduction temperature of 250°C or lower or 550°C or lower, for example 10% or less, and more preferably 5% or less, is mixed in, and another cerium oxide powder with a higher reduction temperature is added in addition. This allows for a greater degree of freedom in designing carbon dioxide adsorption capacity while further suppressing adverse effects on Cu-ZSM5. In this case, it is desirable that the proportion of cerium oxide powder with a lower reduction temperature is smaller than that of cerium oxide powder with a higher reduction temperature among the two types of cerium oxide powders with different reduction temperatures.

[0225] (modified version) The embodiments of this disclosure are not limited to the first to fourth embodiments. The first to fourth embodiments can be modified in various ways depending on the design, etc., as long as the objectives of this disclosure are achieved. The following lists some modifications of the first to fourth embodiments. In the following description, the first to fourth embodiments will be considered as basic examples.

[0226] In the basic example, of the first and second glass plates 200 and 300, only the first glass plate 200 is equipped with the low-emission film 220, but in the modified example, the second glass plate 300 may also be equipped with the low-emission film. That is, both the first and second glass plates 200 and 300 may be equipped with the low-emission film. For this reason, both the first and second glass plates 20 and 30 may also be equipped with the low-emission film.

[0227] In the basic example, of the first and second glass plates 200 and 300, the first glass plate 200 is equipped with a low-emission film 220, while the second glass plate 300 is not. However, in the modified example, the second glass plate 300 may be equipped with a low-emission film, while the first glass plate 200 may not be equipped with a low-emission film 220. Therefore, in the modified glass panel unit 10, the second glass plate 30 may be equipped with a low-emission film, while the first glass plate 20 may not be equipped with a low-emission film 220.

[0228] In the basic example, the exhaust process starts after the first melting process, but in the modified example, the exhaust process may start in the middle of the first melting process after the first melting time tm1 has elapsed and the temperature inside the melting furnace is lower than the first softening point.

[0229] In the basic example, the exhaust process ends at the same time as the second melting process, but in the modified example, the exhaust process may start after the first melting process and end before the second melting process.

[0230] In the basic example, the glass panel unit 10 is rectangular, but in the modified example, the glass panel unit 10 may be any desired shape, such as circular or polygonal. In other words, the first glass plate 20 and the second glass plate 30 may be any desired shape, such as circular or polygonal, rather than rectangular.

[0231] The first and second glass plates 20 and 30 do not have to have the same planar shape and planar size. Furthermore, the first glass plate 20 does not have to have the same thickness as the second glass plate 30. These points also apply to the first and second glass plates 200 and 300.

[0232] The peripheral wall 410 does not have to have the same planar shape as the first and second glass plates 200 and 300.

[0233] The surrounding wall 410 may further include other elements such as a core material.

[0234] Furthermore, in the assembled product 100, the peripheral wall 410 is simply located between the first and second glass plates 200 and 300 and does not join them together. However, at the stage of the assembled product 100, the peripheral wall 410 may join the first and second glass plates 200 and 300 together. In short, in the assembled product 100, the peripheral wall 410 only needs to be located between the first and second glass plates 200 and 300, and it is not essential that they are joined together.

[0235] In the basic example, the partition 420 is not in contact with the peripheral wall 410. As a result, the gaps between both ends of the partition 420 and the peripheral wall 410 form the ventilation passages 610, 620. However, the partition 420 may be connected to the peripheral wall 410 at only one end, in which case a single ventilation passage 600 may be formed between the partition 420 and the peripheral wall 410. Alternatively, both ends of the partition 420 may be connected to the peripheral wall 410. In this case, the ventilation passage 600 may be a through-hole formed in the partition 420. Alternatively, the ventilation passage 600 may be the gap between the partition 420 and the first glass plate 200. Alternatively, the partition 420 may be formed by two or more partitions spaced apart. In this case, the ventilation passage 600 may be the gap interposed between the two or more partitions.

[0236] In the basic example, the ventilation passage 600 has two ventilation passages 610 and 620, but the ventilation passage 600 may consist of only one ventilation passage or three or more ventilation passages. Furthermore, the shape of the ventilation passage 600 is not particularly limited.

[0237] In the basic example, the internal space 500 is divided into one first space 510 and one second space 520. However, the internal space 500 may be divided into one or more first spaces 510 and one or more second spaces 520 by a partition 420. If the internal space 500 has two or more first spaces 510, two or more glass panel units 10 can be obtained from one work-in-progress 110.

[0238] In the basic example, the first space 510 is defined as a vacuum space 50, but a reduced-pressure space may be used instead. The reduced-pressure space is the first space 510 in a reduced-pressure state. A reduced-pressure state is defined as a state where the pressure is lower than atmospheric pressure.

[0239] In the basic example, the weir member 47 is C-shaped, but it may also be a polygonal ring with a portion cut out. Furthermore, the weir member may be omitted.

[0240] In the basic example, the vacuum space 50 is spatially separated from the outside space by a partition wall 42 or a hole sealing material 43. However, in a modified example, the vacuum space 50 may be spatially separated from the outside space by a sealing portion formed by melting and cutting the exhaust pipe connected to the exhaust port 700. In other words, the partition wall 42 or the hole sealing material 43 is not essential as a component for spatially separating the vacuum space 50 from the outside space.

[0241] Furthermore, the exhaust port 700 is not limited to being formed in the first or second glass plate, but may also be formed in the peripheral wall 410 between the first glass plate 200 and the second glass plate 300. Also, when exhausting gas from the exhaust port 700, it is not always necessary to connect an exhaust pipe. For example, an assembly 100 of the glass panel unit 10 before sealing may be placed in a vacuum chamber, and the entire vacuum chamber may be evacuated to create a vacuum space 50 by exhausting the inside of the glass panel unit 10 through the gap in the peripheral wall 410, and then the peripheral wall 410 may be heated to seal it.

[0242] (summary) As is evident from the above basic examples and modifications, this disclosure includes the following aspects.

[0243] The first embodiment is a glass panel unit (10; 10A) comprising a first glass plate (20), a second glass plate (30), a frame (40), a vacuum space (50), and a gas adsorbent (60). The second glass plate (30) faces the first glass plate (20). The frame (40) hermetically joins the first glass plate (20) and the second glass plate (30). The vacuum space (50) is surrounded by the first glass plate (20), the second glass plate (30), and the frame (40). The gas adsorbent (60) is placed within the vacuum space (50). The gas adsorbent (60) has at least particles made of zeolite and particles made of a cerium compound.

[0244] According to the first embodiment, by including particles made of zeolite and particles made of cerium compound in the gas adsorbent (60), it is possible to make it difficult for gas to remain in the vacuum space (50).

[0245] The second embodiment is a glass panel unit (10;10A) of the first embodiment, wherein the proportion of the cerium compound is 50% by mass or less with respect to the total mass of the getter material of the gas adsorbent (60).

[0246] According to the second embodiment, the amount of oxygen detached from the cerium compound can be reduced, making it less likely for this oxygen to remain in the vacuum space (50) after the sealing process.

[0247] A third embodiment is a glass panel unit (10;10A) according to the first or second embodiment, wherein the gas adsorbent (60) contains more zeolite than cerium compound.

[0248] According to the third embodiment, the amount of oxygen detached from the cerium compound can be reduced, making it less likely for this oxygen to remain in the vacuum space (50) after the sealing process.

[0249] The fourth embodiment is a glass panel unit (10;10A) according to any one of the first to third embodiments, wherein the zeolite includes copper ion exchange zeolite.

[0250] According to the fourth embodiment, it is possible to make it less likely for gas to remain in the vacuum space (50).

[0251] The fifth embodiment is a glass panel unit (10;10A) of any one of the first to fourth embodiments, wherein the cerium compound is cerium oxide, and the particles made of the cerium compound exhibit an oxygen release curve having a temperature at which the amount of oxygen released is maximum in a temperature-controlled desorption gas analysis when the temperature is increased at 30°C / min. The oxygen release curve is such that the maximum point of the oxygen release curve is 200°C or less, or the maximum point of the oxygen release curve is 250°C or higher, and the oxygen release onset temperature is 250°C or higher.

[0252] According to the fifth embodiment, even in a gas adsorbent (60) containing the zeolite and the cerium compound, the gas adsorption performance of the zeolite and the cerium compound is less likely to be affected.

[0253] The sixth embodiment is a glass panel unit (10;10A) according to any one of the first to fifth embodiments, wherein the gas adsorbent (60) has a mixture of particles made of the zeolite and particles made of the cerium compound.

[0254] According to the sixth aspect, it is possible to make it difficult for gas to remain in the vacuum space (50).

[0255] The seventh aspect is any one of the first to fifth aspect glass panel units (10; 10A), and the gas adsorbent (60) includes a first gas adsorbent (61, 601) containing particles made of the zeolite, and a second gas adsorbent (62, 602) containing particles made of the cerium compound. The first gas adsorbent (61, 601) and the second gas adsorbent (62, 602) are separately arranged in the vacuum space (50).

[0256] According to the seventh aspect, since the first gas adsorbent (61, 601) contains zeolite and the second gas adsorbent (62, 602) contains a cerium compound, it is possible to make it difficult for gas to remain in the vacuum space (50). Also, by separately forming the first gas adsorbent (61, 601) containing zeolite and the second gas adsorbent (62, 602) containing a cerium compound, each of the zeolite and the cerium compound is less likely to affect the gas adsorption performance of the other. Moreover, the degree of freedom in the arrangement positions of the first gas adsorbent (61, 601) and the second gas adsorbent (62, 602) increases, and the designability is excellent.

[0257] The eighth aspect is the glass panel unit (10; 10A) of the seventh aspect, and the first gas adsorbent (61, 601) and the second gas adsorbent (62, 602) are arranged apart from each other.

[0258] According to the eighth aspect, each of the zeolite and the cerium compound is less likely to affect the gas adsorption performance of the other.

[0259] The ninth embodiment is a glass panel unit (10; 10A) according to the seventh or eighth embodiment, wherein either a first gas adsorbent (61, 601) or a second gas adsorbent (62, 602) is arranged over the entire surface of at least one of the first glass plate (20) and the second glass plate (30). The other of the first gas adsorbent (61, 601) or the second gas adsorbent (62, 602) is arranged along the outer circumference of at least one of the first glass plate (20) and the second glass plate (30).

[0260] According to the ninth embodiment, the degree of freedom in the placement of the first gas adsorbent (61, 601) and the second gas adsorbent (62, 602) is increased, resulting in superior design.

[0261] The tenth embodiment is a glass panel unit (10) according to the first to ninth embodiments, wherein the first glass plate (20) and the second glass plate (30) are not provided with exhaust ports (700).

[0262] According to the tenth embodiment, by including a zeolite and a cerium compound in the gas adsorbent (60), it is possible to reduce the amount of gas remaining in the vacuum space (50). Furthermore, it is possible to reduce the deterioration of appearance due to the exhaust port (700).

[0263] The eleventh embodiment is a composite getter material containing particles made of zeolite and particles made of a cerium compound.

[0264] According to the eleventh embodiment, when the composite getter material is placed in a vacuum space (50), gas is less likely to remain in this vacuum space (50).

[0265] The twelfth embodiment is a composite getter material according to the eleventh embodiment, wherein the proportion of the cerium compound is 50% by mass or less with respect to the mass of the composite getter material.

[0266] According to the twelfth embodiment, when the composite getter material is placed in a vacuum space (50), the amount of oxygen that is removed from the cerium compound can be reduced, so that this oxygen is less likely to remain in the vacuum space (50).

[0267] The 13th aspect is a getter paste, which is a mixture of a composite getter material according to the 11th or 12th aspect and a solvent.

[0268] According to the 13th embodiment, in the getter paste, the solvent is present so as to surround the particles made of zeolite and the particles made of cerium compound, so that the particles made of zeolite and the particles made of cerium compound do not come into contact with air. As a result, the particles made of zeolite and the particles made of cerium compound do not adsorb air easily. Therefore, the getter paste can be stored easily. In addition, when the solvent is water, compared to when organic solvents such as alcohol or terpineol are used, no organic components that are difficult to desorb remain on the zeolite, especially copper ion exchange zeolite (Cu-ZSM5). Therefore, even at low temperatures in the exhaust process, gas can be sufficiently desorbed from the zeolite, and high adsorption performance can be obtained.

[0269] The 14th aspect is a method for manufacturing a glass panel unit (10;10A), comprising a processing step, an assembly step, a joining step, and an exhaust step. The processing step includes a composite getter material manufacturing step for obtaining a composite getter material containing particles made of zeolite and particles made of a cerium compound. The assembly step is a step for preparing an assembled product (100;101). The assembled product (100;101) comprises a first glass plate (200;20), a second glass plate (300;30), a frame-shaped peripheral wall (410), an internal space (500), a gas adsorbent (60), and an exhaust port (700). The second glass plate (300;30) faces the first glass plate (200;20). The peripheral wall (410) is located between the first glass plate (200;20) and the second glass plate (300;30). The internal space (500) is surrounded by a first glass plate (200;20), a second glass plate (300;30), and a peripheral wall (410). The gas adsorbent (60) is placed within the internal space (500) and contains the composite getter material. The exhaust port (700) connects the internal space (500) to the external space. The joining process is a process of melting the peripheral wall (410) to hermetically join the first glass plate (200;20) and the second glass plate (300;30). The exhaust process is a process of exhausting the internal space (500) through the exhaust port (700) to create a vacuum space (50).

[0270] According to the 14th embodiment, by including a zeolite and a cerium compound in the gas adsorbent (60), it is possible to make it less likely for gas to remain in the vacuum space (50).

[0271] The 15th aspect is a method for manufacturing a glass panel unit (10;10A) according to the 14th aspect, wherein the processing step further includes a mixing step of mixing the composite getter material and a solvent to obtain a getter paste.

[0272] According to the 15th embodiment, since the solvent is present so as to cover the particles made of zeolite and the particles made of cerium compound, the particles made of zeolite and the particles made of cerium compound are less likely to come into contact with air. As a result, the getter material is less likely to adsorb air. Therefore, the storage of the getter paste becomes easier, and the complexity of manufacturing the glass panel unit (10;10A) can be reduced.

[0273] The sixteenth aspect is a method for manufacturing a glass panel unit (10;10A), comprising a processing step, an assembly step, a joining step, and an exhaust step. The processing step includes a getter paste manufacturing step for obtaining a first getter paste containing particles made of zeolite and a second getter paste containing particles made of a cerium compound. The assembly step is a step for preparing an assembled product (100;101). The assembled product (100;101) comprises a first glass plate (200;20), a second glass plate (300;30), a frame-shaped peripheral wall (410), an internal space (500), a first gas adsorbent (61;601), a second gas adsorbent (62;602), and an exhaust port (700). The second glass plate (300;30) faces the first glass plate (200;20). The peripheral wall (410) is located between the first glass plate (200;20) and the second glass plate (300;30). The internal space (500) is enclosed by the first glass plate (200;20), the second glass plate (300;30), and the peripheral wall (410). The first gas adsorbent (61;601) is placed in the internal space (500) and formed from the first getter paste. The second gas adsorbent (62;602) is placed in the internal space (500) and formed from the second getter paste. The exhaust port (700) connects the internal space (500) and the external space. The joining process is a process of melting the peripheral wall (410) to airtightly join the first glass plate (200;20) and the second glass plate (300;30). The exhaust process involves exhausting the internal space (500) through the exhaust port (700) to create a vacuum space (50).

[0274] According to the 16th aspect, since the first gas adsorbent (61; 601) contains zeolite and the second gas adsorbent (62; 602) contains a cerium compound, it is possible to make it difficult for gas to remain in the vacuum space (50). Further, by separately forming the first gas adsorbent (61; 601) containing zeolite and the second gas adsorbent (62; 602) containing a cerium compound, each of the zeolite and the cerium compound is less likely to affect the gas adsorption performance of each other. Moreover, the degree of freedom in the arrangement positions of the first gas adsorbent (61; 601) and the second gas adsorbent (62; 602) increases, and the designability is excellent.

[0275] The 17th aspect is a method for manufacturing the glass panel unit (10; 10A) according to the 15th or 16th aspect, wherein the assembly step includes a drying step of drying each getter paste to obtain each gas adsorbent (60; 61; 601; 62; 602).

[0276] According to the 17th aspect, the gas adsorption property of each gas adsorbent (60; 61; 601; 62; 602) can be restored by drying each getter paste.

[0277] The 18th aspect is a method for manufacturing the glass panel unit (10; 10A) according to any one of the 14th to 17th aspects, wherein the peripheral wall (410) contains one or both of an organic binder and an organic solvent.

[0278] According to the 18th aspect, even if gas derived from the organic binder is released into the vacuum space (50) after the sealing step, the gas adsorbent (60) adsorbs this gas, making it difficult for gas to remain in the vacuum space (50).

[0279] In the 19th aspect, the getter paste is applied near the outer periphery inside the glass panel with a dispenser or sprayed with a device such as a spray coater.

[0280] According to the 19th aspect, it is possible to realize a glass panel in which the getter material is inconspicuous and the appearance is excellent.

Explanation of Signs

[0281] 10 Glass Panel Units 10A Glass Panel Unit 100 Assembled items 101 Assembled product 20 First glass plate 200 First glass plate (first glass substrate) 30. Second glass plate 300 Second glass plate (second glass substrate) 40 Frame 50 Vacuum space 60 Gas adsorbent 61 First gas adsorbent 62 Second gas adsorbent 410 Peripheral wall 500 interior space 700 exhaust port

Claims

1. A composite getter material containing at least particles made of zeolite and particles made of a cerium compound, The zeolite is a copper ion-exchanged ZSM-5 type zeolite. The cerium compound is cerium oxide, The particles made of the zeolite and the particles made of the cerium compound are not supported on each other. The proportion of the cerium compound is 50% by mass or less relative to the mass of the composite getter material. The particles made of the cerium compound have an average particle diameter of 10 nm or more and 30 μm or less. The particles made of the zeolite have an average particle diameter of 10 nm to 30 μm. Composite getter material.

2. A mixture of the composite getter material and solvent described in claim 1, Getta paste.

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