Glass bonding material and use thereof

Abstract

To provide a glass bonding material that exhibits superior water resistance.SOLUTION: A glass bonding material for low-temperature bonding at 650°C or lower, comprises a glass composition. When the total of the glass composition is 100 mol%, the glass composition comprises, in terms of oxides, the following components: TeO2: 50 mol% or more and 85 mol% or less, ZnO: 5 mol% or more and 15 mol% or less, and BaO: 1 mol% or more and 40 mol% or less, and the total of these components accounts for 90 mol% or more of the entire glass composition.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a glass bonding material, and more particularly to a glass bonding material that can be used for bonding in a low temperature range. [Background technology]

[0002] Metallic materials are widely used in various industrial fields as structural members in various devices, equipment, and apparatus. To join members made of such metallic materials (metallic members), various joining materials are used depending on the application of the metallic members, joining conditions, etc.

[0003] For example, organic adhesives or glass bonding materials are generally used to bond metal components. Organic adhesives have elasticity, which allows them to mitigate thermal expansion at the joints of metal components. However, organic adhesives are inherently inferior to glass bonding materials in chemical and physical durability, heat resistance, electrical insulation, and mechanical strength. Therefore, organic adhesives tend to be avoided in applications requiring durability and heat resistance, as well as the associated airtightness, electrical insulation, and mechanical strength. For such bonding, heat-resistant glass bonding materials have traditionally been used.

[0004] Furthermore, in order to improve performance, reduce weight, and cut costs, the use of aluminum-based materials, for example, as metal components in devices is increasing. However, metal components with low melting points (approximately 660°C), such as aluminum, may deform when bonded at high temperatures. Therefore, there is a demand for glass bonding materials that can be bonded at low temperatures.

[0005] For example, Japanese Patent Application Laid-Open No. 2008-308393 and Japanese Patent Application Laid-Open No. 2011-516537 disclose phosphate-based glass bonding materials. These phosphate-based glass bonding materials contain P2O5 as the main glass-forming oxide that constitutes glass. P2O5 forms the glass skeleton and lowers the softening point of the glass, thereby lowering the bonding temperature. These glass bonding materials also contain SiO2 or Al2O3 to improve water resistance. As a result, these materials are exemplified as phosphate-based glass bonding materials with excellent water resistance (and even hot water resistance).

[0006] Furthermore, JP 2017-533164 A discloses a tellurite-based glass bonding material that can bond glass sheets for manufacturing vacuum insulating glass at processing temperatures of 420°C or lower. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-308393 [Patent Document 2] Special Publication No. 2011-516537 [Patent Document 3] Special Publication No. 2017-533164 Summary of the Invention [Problem to be solved by the invention]

[0008] However, depending on the device, the glass bonding material used for bonding may be required to be water resistant. For example, in electrochemical cells such as solid oxide electrolysis cells (SOECs) and solid oxide fuel cells (SOFCs), glass bonding parts (glass bonding parts) are exposed to high-temperature water vapor. In addition to the high-temperature and high-humidity environments described above, even when placed in a humid environment for a long period of time, the glass bonding parts may gradually absorb moisture from the air and may be deteriorated. For this reason, there has been a demand in recent years for the development of glass bonding materials with excellent water resistance.

[0009] Therefore, the present disclosure provides a glass bonding material that can be bonded at low temperatures and has excellent long-term water resistance. [Means for solving the problem]

[0010] The glass bonding material disclosed herein is a glass bonding material for low-temperature bonding at 650° C. or less. The glass composition contained in the glass bonding material contains the following components in oxide terms when the entire glass composition is taken as 100 mol %: TeO2: 50 mol% or more and 85 mol% or less, ZnO: 5 mol% or more and 15 mol% or less, BaO: 1 mol% or more and 40 mol% or less, The total amount of each of the above components is 90 mol % or more of the entire glass composition.

[0011] As a result of various experiments, the inventors discovered that the glass bonding material having the above-described configuration enables bonding at low temperatures and forms glass bonding joints with excellent water resistance (especially long-term water resistance). While not intending to limit the technology disclosed herein, it is speculated that this water resistance is achieved through the following mechanism. First, the glass composition of the glass bonding material disclosed herein contains a tellurium component (TeO). The tellurium component enables low-temperature bonding of the glass bonding material and can improve its water resistance. Next, the zinc component (ZnO) can improve the stability of the glass bonding joint and improve its water resistance. Furthermore, the barium component (BaO) can improve the thermal stability without reducing the water resistance of the glass bonding joint. The technology disclosed herein has achieved a glass bonding material for low-temperature bonding with excellent water resistance by mixing these components in an appropriate ratio.

[0012] The glass composition of the glass bonding material according to one embodiment disclosed herein further contains Al2O3 in an amount of 10 mol% or less, calculated as an oxide, when the total amount of the glass composition is 100 mol%. The addition of Al2O3 further stabilizes the glass matrix, thereby further improving the water resistance of the glass bonding material.

[0013] In one embodiment of the glass bonding material disclosed herein, the thermal expansion coefficient of the glass bonding material from 30°C to 300°C is 14×10 -6 K -1 ~19×10 -6 K -1 This reduces the difference in thermal expansion coefficient between the materials to be joined (for example, metal members). As a result, damage to the joint due to the difference in the amount of expansion can be suppressed.

[0014] The glass bonding material of one embodiment disclosed herein has a yield point of 300° C. or more and 500° C. or less, which allows bonding at a lower temperature more reliably.

[0015] The glass bonding material of one embodiment disclosed herein is intended for metal members, which allows the effects of the glass bonding material of the present disclosure to be more suitably exhibited.

[0016] The metal member to which the glass bonding material of one embodiment disclosed herein is applied has a thermal expansion coefficient of 16×10 from 30° C. to 300° C. -6 K -1 ~22×10 -6 K -1 This metal member is made of a metal material that can bond objects more strongly.

[0017] The metal member targeted by the glass bonding material of one embodiment disclosed herein is selected from the group consisting of at least aluminum, copper, alloys thereof, and stainless steel, thereby enabling stronger bonding of the objects to be bonded.

[0018] The glass bonding material of one embodiment disclosed herein does not contain vanadium (V). The vanadium component is a component that causes a decrease in the water resistance of the glass bonding material. Therefore, the glass bonding material of one embodiment disclosed herein that does not contain a vanadium component can prevent problems such as a decrease in the water resistance of the glass bonding material.

[0019] One embodiment of the bonded structure disclosed herein is a bonded structure of a first metal member and a second metal member. The bonded portion bonding the two metal members is made of the glass bonding material of the present disclosure. This provides a bonded structure having a glass bonding portion that has long-term water resistance.

[0020] In one embodiment of the bonded structure disclosed herein, either or both of the first metal member and the second metal member are made of a metal member selected from aluminum, copper, alloys thereof, and stainless steel, thereby further improving the strength of the bonded joint. [Brief explanation of the drawings]

[0021] [Figure 1] FIG. 1 is a cross-sectional view schematically showing the configuration of a bonded body according to one embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0022] Exemplary embodiments of the present disclosure are described in detail below. Matters necessary for implementation (e.g., raw materials, methods, and processing methods for preparing a glass bonding material) other than those specifically mentioned in this specification (e.g., the composition, physical properties, and other characteristics of the glass bonding material) can be understood as design matters of a person skilled in the art based on the prior art in the relevant field. The present disclosure can be implemented based on the contents disclosed in this specification and the common general technical knowledge in the relevant field. In the drawings described in this specification, components and parts that perform the same function are denoted by the same reference numerals, and redundant descriptions may be omitted or simplified. Furthermore, the dimensional relationships (length, width, thickness, etc.) in each drawing do not necessarily reflect the actual dimensional relationships.

[0023] <Terminology> In this specification, when a numerical range is described as "A to B (where A and B are any numerical values)," it means "A or more and B or less," and also encompasses the meanings of "greater than A and less than B," "greater than A and B or less," and "greater than A and less than B."

[0024] In this specification, the term "thermal expansion coefficient" refers to the average expansion coefficient (average linear expansion coefficient) measured using a thermomechanical analysis (TMA) in the temperature range of 30°C to 300°C, and refers to the value obtained by dividing the change in sample length relative to the initial length of the sample by the temperature difference. The thermal expansion coefficient can be measured, for example, in accordance with JIS R3102:1995.

[0025] In this specification, a "tellurite-based" glass sealing material is a glass sealing material whose main component is tellurite. In other words, a tellurite-based glass sealing material is a glass sealing material whose glass composition contains tellurium (Te). In addition, in this specification, the term "main" used to describe the amount of a component in a composition or article means that the amount exceeds 50 mol%.

[0026] <Glass bonding material> In this embodiment, a glass bonding material for low-temperature bonding is described for bonding a first metal member and a second metal member at a low temperature of 650°C or less. In this specification, the term "metal member" refers to a member whose main component is a metal material. In this specification, "low temperature" is understood to mean a temperature of 650°C or less.

[0027] <Glass composition> The glass bonding material disclosed herein contains a glass composition as a main component. Typically, the content of the glass composition, when the entire glass bonding material is taken as 100 wt%, is preferably 50 wt% or more, more preferably 70 wt% or more, even more preferably 80 wt% or more, and particularly preferably 90 wt% or more. The upper limit of the content of the glass composition is not particularly limited. The upper limit of the content of the glass composition may be 100 wt%, 99 wt% or less, or 95 wt% or less. In this specification, unless otherwise specified, "wt%" means "g / 100g", i.e., the mass (g) of the target component (here, the glass composition) contained in 100 g of the glass bonding material.

[0028] The glass composition disclosed herein comprises, when the entire glass composition is taken as 100 mol %, TeO2: 50 mol% or more and 85 mol% or less, ZnO: 5 mol% or more and 15 mol% or less, BaO: 1 mol% or more and 40 mol% or less, The total of the above components is set to be 90 mol % or more (preferably 92 mol % or more, more preferably 94 mol % or more, even more preferably 96 mol % or more, most preferably 98 mol % or more, and may be 100 mol %) of the entire glass composition. In this specification, "mol %" in the content and total content of glass components means the molar ratio converted to oxide, unless otherwise specified.

[0029] <Essential ingredients> The glass composition of the glass bonding material disclosed herein contains tellurium (Te), zinc (Zn), and barium (Ba) as essential components. Each component contained in the tellurite-based glass bonding material of the present disclosure will be described below in order.

[0030] <Tellurium (Te)> The glass composition of the glass bonding material disclosed herein contains a Te component (TeO2). The Te component is a main glass-forming oxide (network former) in the glass bonding material disclosed herein. Glasses having a skeleton containing a Te component have a lower softening point (or melting point) than glasses having a skeleton containing other components (e.g., SiO2), thereby contributing to a lower bonding temperature. The Te component also has the function of improving the water resistance of the glass composition. As the proportion of the Te component increases, the water resistance tends to improve. From this perspective, in the glass bonding material disclosed herein, the proportion of TeO2 in the entire glass composition is set to 50 mol% or more. Furthermore, if the proportion of TeO2 is too low, the glass transition temperature may increase and the low-temperature sealing property may deteriorate. Furthermore, since crystallization may occur easily during sealing and firing, the lower limit of TeO2 is preferably 55 mol% or more, more preferably 60 mol% or more, and even more preferably 65 mol% or more. On the other hand, although the Te component is a glass-forming oxide, it is difficult to vitrify it alone, but vitrification occurs when it is combined with other components. Therefore, if the content of the Te component is too high, the other components become relatively small, making vitrification difficult. Therefore, the upper limit of TeO2 is set to 90 mol% or less. Furthermore, as the proportion of the Te component increases, the thermal expansion coefficient tends to increase. From the viewpoint of obtaining an appropriate thermal expansion coefficient, the upper limit of TeO2 is preferably 85 mol% or less, more preferably 80 mol% or less, and even more preferably 75 mol% or less.

[0031] <Zinc (Zn)> The glass composition of the glass bonding material disclosed herein contains a Zn component (zinc oxide (ZnO)). The Zn component adjusts the viscosity of the glass bonding material during firing and has the function of improving the airtightness and stability of the glass bonding part formed after firing. Furthermore, the Zn component is stable to water at a pH of 6 to 14, and therefore can contribute to improving the water resistance of the glass bonding part. From this perspective, in the glass bonding material disclosed herein, the proportion of ZnO in the entire glass composition is set to 5 mol % or more. From the perspective of suitably achieving this effect, the lower limit of ZnO is preferably 6 mol % or more, more preferably 7 mol % or more, and even more preferably 8 mol % or more. The Zn component is an intermediate oxide that vitrifies together with other components (here, the Te component). Such ZnO, when combined with the above-mentioned TeO2, enhances the stability of the glass bonding material. Furthermore, as the proportion of ZnO increases, the thermal expansion coefficient tends to decrease. The Zn component makes it easy to adjust the thermal expansion coefficient. If the proportion of ZnO is increased too much, Zn-based crystals are likely to precipitate excessively, which may increase the glass viscosity and impair low-temperature bondability. Therefore, the upper limit of ZnO is set to 15 mol% or less. From the viewpoint of optimally obtaining such effects, the upper limit of ZnO is preferably 14 mol% or less, more preferably 13 mol% or less, and even more preferably 12 mol% or less.

[0032] <Barium (Ba)> The glass composition of the glass bonding material disclosed herein contains a Ba component (barium oxide (BaO)). The Ba component is a modifying oxide that plays a role in stabilizing glass. In particular, in tellurite-based glasses, the atomic radii of Te and Ba in the glass matrix are similar, making the Ba component an effective component for stabilizing glass. The Ba component can improve the thermal stability of the glass bonding material without reducing its water resistance. From this perspective, in the glass bonding material disclosed herein, the proportion of BaO in the entire glass composition is set to 1 mol% or more. From the perspective of suitably achieving this effect, the lower limit of BaO is preferably 5 mol% or more, more preferably 10 mol% or more, and even more preferably 15 mol% or more. The Ba component significantly reduces the viscosity of the glass after melting. The Ba component makes it easy to adjust the glass viscosity. Furthermore, the thermal expansion coefficient tends to increase as the proportion of BaO increases. The upper limit of BaO is set to 40 mol% or less. From the viewpoint of adjusting the thermal expansion coefficient, the upper limit of BaO is preferably 35 mol % or more, more preferably 30 mol % or more, and even more preferably 25 mol % or more.

[0033] <Optional ingredients> The glass composition may also typically contain aluminum (Al) as an optional component. The optional components contained in the glass bonding material of the present disclosure will be described below.

[0034] <Aluminum (Al)> The glass composition of the glass bonding material disclosed herein may contain an Al component (aluminum oxide (Al2O3)). The Al component controls the fluidity of the glass matrix during melting and contributes to adhesion stability. From this perspective, the glass bonding material disclosed herein may contain Al2O3 as an optional component. That is, in the present disclosure, Al2O3 is a non-essential component, unlike the above-mentioned three components, TeO2, ZnO, and BaO. Al2O3 is an intermediate oxide that stabilizes the glass matrix and plays a role in improving chemical durability and weather resistance. In a preferred embodiment, the water resistance of the glass bonding material can be further improved by further adding Al2O3 to the glass composition containing the above three components so that the proportion of Al2O3 in the entire glass composition is 10 mol% or less. Furthermore, the addition of Al2O3 together with the Ba component can generate BaAl2O4 crystals in the glass matrix. Such crystals further improve the thermal stability of the glass bonding material, thereby achieving more suitable heat resistance and durability. From the viewpoint of improving the water resistance of the glass, the lower limit of Al2O3 is more preferably 3 mol% or more. However, if the proportion of Al2O3 exceeds 10 mol%, the glass network bonds become stronger, and the softening point of the glass becomes too high. As a result, this is undesirable because it leads to a deterioration in bondability and an increase in bonding temperature. Furthermore, as the proportion of the Al component increases, the thermal expansion coefficient also tends to decrease. From this viewpoint, the upper limit of the Al2O3 content is more preferably 8 mol% or less.

[0035] <Other optional ingredients> The glass composition disclosed herein may contain optional components other than the above four components, as long as the effects of the technology disclosed herein are not significantly impaired. Examples of such optional components include La2O3, NiO, ZrO2, Nb2O5, SnO, SnO2, CeO2, and Cu2O. Adding these optional components to form a multi-component glass composition can improve the physical stability of the joint after firing. However, from the standpoints of workability and cost, it is preferable that the glass composition be composed of 10 or fewer components. When these optional components other than the Al component are added, the proportion of these optional components in the entire glass composition is preferably 0.01 mol% to 1.00 mol% or less, more preferably 0.05 mol% to 0.75 mol%, and even more preferably 0.1 mol% to 0.5 mol%.

[0036] <Prohibited ingredients> In order to prevent the occurrence of the following problems, the glass bonding material (or glass composition) disclosed herein preferably does not substantially contain vanadium (V), phosphorus (P), alkali metals, boron (B), lead (Pb), bismuth (Bi), or arsenic (As). First, the glass composition of the glass bonding material of the present disclosure preferably does not substantially contain the V component, the P component, or an alkali metal element. The V component, the P component, and an alkali metal element significantly reduce the water resistance of the glass bonding material. Therefore, the glass bonding material of the present disclosure, which does not substantially contain these components, can prevent deterioration of the glass (bonding portion) surface due to moisture absorption. Second, the glass composition of the glass bonding material of the present disclosure preferably does not substantially contain an alkali metal element. Examples of such alkali metal elements include lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), and francium (Fs). Glass joining materials containing these alkali metal elements (especially Na and K) may produce substances that adversely affect the environment during firing. For example, when a glass joining material containing alkali metal elements is used to join ferritic stainless steel, hexavalent chromium, an environmentally restricted substance, may be produced. In contrast, the glass joining material of the present disclosure is substantially free of alkali metal elements, thereby preventing the generation of environmentally restricted substances during firing. Furthermore, the glass composition of the glass joining material of the present disclosure preferably is substantially free of Pb and As components. This prevents the adverse effects of Pb and As on the human body and the environment. Furthermore, the glass composition of the glass joining material of the present disclosure is also substantially free of Bi and B components. The Bi and B components significantly reduce the thermal expansion coefficient of the glass joining material. Therefore, the glass joining material of the present disclosure, which is substantially free of Bi or B components, can prevent an extreme decrease in the joining strength of the glass (joined portion). Note that, in this specification, "substantially free of" refers to the absence of intentional addition of the prohibited components described above. Therefore, when a component that can be construed as a prohibited component is contained in a trace amount due to raw materials or the manufacturing process, this is included in the concept of "substantially not contained" in this specification.For example, when the content of the prohibited components in the entire glass composition is 0.1 mol% or less (preferably 0.005 mol% or less, more preferably 0.01 mol% or less, even more preferably 0.0005 mol% or less, and particularly preferably 0.0001 mol% or less), it can be said to be "substantially not contained."

[0037] <Characteristics of glass bonding material> The glass bonding material of this embodiment as described above has the property of being able to suitably bond objects to be bonded during low-temperature firing at a bonding temperature of 650°C or less. The bonding temperature can be changed within a range of 650°C or less by appropriately adjusting the components of the glass composition. For example, the bonding temperature can be adjusted to be in the range of 300°C to 650°C, more specifically, 320°C to 550°C, and even more specifically, 350°C to 500°C.

[0038] The components of the above-mentioned glass composition are preferably adjusted appropriately from the viewpoint of making the thermal expansion coefficient similar to that of the objects to be joined. For example, the glass joining material disclosed herein has a thermal expansion coefficient of 14×10 between 30°C and 300°C. -6 K -1 ~19×10 -6 K -1 (More preferably 15 × 10 -6 K -1 ~18×10 -6 K -1 This makes it possible to prevent damage to the joint due to a difference in the amount of expansion between the joint and the object to be joined.

[0039] In addition to the above properties, the glass bonding material disclosed herein has water resistance with a weight loss rate of less than 3% when immersed in hot water at 70°C to 90°C for 24 hours. The glass bonding material disclosed herein also has water resistance with a weight gain rate of less than 1% when left in an atmospheric environment for one month. Note that the "atmospheric environment" in this specification refers to the standard conditions defined in JIS Z 8703-1983. Specifically, this refers to a pressure of 1 atmosphere (1013 hPa), a temperature of 25°C, and a humidity of 50% RH. As described above, the glass bonding material disclosed herein forms a bonding part (which can also be called a sealing part) with excellent water resistance, and therefore can be suitably used in a water vapor atmosphere.

[0040] <Materials other than glass compositions> In addition to the glass composition described above, the glass bonding material disclosed herein may contain, as appropriate, conventionally known materials that can be added to this type of glass bonding material. Examples of such additives include organic binders and organic solvents. Examples of organic binders include various binders typically used in this type of glass paste. Examples include cellulose-based polymers such as methyl cellulose, ethyl cellulose, and nitrocellulose, as well as acrylic resins, epoxy resins, and amine resins. Similarly, examples of organic solvents include various organic solvents typically used in this type of glass paste. Examples include terpineol, ether-based solvents, ester-based solvents, and various glycols.

[0041] The form of the glass bonding material disclosed herein is not particularly limited. Any form can be adopted depending on the application. For example, the glass bonding material may be in the form of cullet, powder, frit, pellet, sheet, paste, or the like. For example, in the case of a paste-like glass bonding material, by appropriately adjusting the viscosity, it can be easily applied to the bonding object by a method such as coating or printing. Furthermore, from the viewpoint of operational convenience, a form can be adopted in which a sheet-like bonding material is formed in advance and the sheet-like bonding material is attached to the bonding object.

[0042] <Method of manufacturing glass bonding material> Next, an example of a method for producing the glass bonding material disclosed herein will be described. Note that the description of this manufacturing method is not intended to limit the glass bonding material disclosed herein.

[0043] When manufacturing the glass bonding material disclosed herein, first, a raw material powder containing the above-mentioned TeO2, ZnO, and BaO as main components (the three main components occupy 90 mol% or more in terms of molar ratio of oxides) is prepared. For example, industrial products, reagents, or various mineral raw materials containing oxides, carbonates, nitrates, composite oxides, etc. containing the various components described above are prepared and mixed to achieve the desired composition ratio. The mixing and preparation of this raw material powder can be performed, for example, by charging the raw materials into a mixer such as a ball mill and mixing for several hours to several tens of hours.

[0044] Next, the obtained glass raw material powder is dried and then heated under a predetermined temperature condition (typically, 900°C to 1200°C) to melt the glass raw material powder. The molten glass is then cooled (preferably rapidly cooled) to obtain a glass composition having the above-mentioned configuration. The obtained glass composition is then crushed and classified (sieved) to a desired size (particle size), thereby obtaining a glass powder in the form of cullets or powder. The average particle size of such glass powder is preferably, for example, 0.5 μm to 50 μm (typically, 1 μm to 10 μm).

[0045] The obtained glass powder is then processed into a desired shape to obtain a glass bonding material. The means for processing the glass bonding material into a desired shape can be any conventionally known method without particular limitation, as long as it does not significantly impair the effects of the technology of the present disclosure. For example, a pellet-shaped glass bonding material can be obtained by compression-molding the glass powder into a desired shape and then calcining it. Alternatively, a paste-shaped glass bonding material can be obtained by mixing the glass powder with an organic material such as a binder or an organic solvent.

[0046] <Joining method> As described above, the glass bonding material disclosed herein is easily fixed by low-temperature firing at 650°C or less and exhibits favorable heat resistance after firing. Therefore, it is preferably used for forming a sealing joint of a bonded body to be used in a temperature environment of 650°C or less, which is lower than conventional temperatures.

[0047] As described above, the joining object in the technology disclosed herein is, for example, a metal member. The metal member to be joined can be a member made of a metal material having a relatively similar thermal expansion coefficient. Typically, the thermal expansion coefficient of the metal material is similar to that of the glass joining material of the present disclosure. Furthermore, in order to improve the strength of the joining, the joining object is a metal member having a thermal expansion coefficient slightly higher than that of the glass joining material of the present disclosure. Specifically, the lower limit of the thermal expansion coefficient from 30°C to 300°C is 16×10 -6 K -1 The upper limit of the thermal expansion coefficient from 30°C to 300°C is 22 × 10 -6 K -1 (More specifically, 20 x 10 -6 K -1 ) are preferred. Examples of metal materials include aluminum, chromium, iron, nickel, copper, silver, manganese, and alloys thereof, stainless steel, etc. Among these, the glass bonding material disclosed herein is particularly suitable for use when bonding metal members such as aluminum, copper, and alloys thereof, as well as stainless steel (especially austenitic stainless steel). For example, the strength of aluminum is significantly reduced when heated to temperatures above 660°C, so the firing temperature when forming a sealed bonded portion is required to be less than 660°C. The glass bonding material disclosed herein can ensure suitable bondability even when fired at a low temperature of 650°C or less, as described above, thereby effectively preventing deterioration of the aluminum and other materials. The surfaces of the metal members to be bonded may be coated with a ceramic. Examples of ceramics used for such coatings include zirconia, alumina, forsterite, titania, yttria, magnesia, and manganese-cobalt oxide.

[0048] <zygote> The glass bonding material disclosed herein can provide a bonded body in which a first metal member and a second metal member are bonded. The bonded portion bonding the two metal members is formed of the glass bonding material of the present disclosure. FIG. 1 is a cross-sectional view schematically illustrating the configuration of a bonded body according to one embodiment bonded using the glass bonding material of the present disclosure. FIG. 1 schematically illustrates the bonded portion so that the bonded state between the first metal member and the second metal member can be seen. Note that FIG. 1 illustrates a case in which the first metal member is primarily composed of aluminum and the second metal member is primarily composed of austenitic stainless steel. However, this is not intended to limit the present disclosure to such a configuration. For example, either or both of the first metal member and the second metal member may be formed of a metal member selected from aluminum, copper, alloys thereof, and stainless steel. As shown in FIG. 1, the bonded body 1 includes a glass bonding material portion 10 between aluminum 20 and austenitic stainless steel 21. A bonded structure bonded with the glass bonding material of the present disclosure as described above has a bonded portion with excellent water resistance, and therefore can maintain a strong bonded state even when exposed to the atmospheric environment for a long period of time. [Example]

[0049] Test examples relating to the technology disclosed herein will be described below, although it is not intended that the technology of the present disclosure be limited to such test examples.

[0050] <Sample Preparation (Example)> In this test, six types of glass powders (Examples 1 to 6) were prepared by varying the components of the glass composition. Specifically, raw material powders of predetermined compositions were melted at 1000 to 1100°C for 1 hour and then rapidly cooled to obtain glass bodies. Next, these glass bodies were crushed and classified to prepare glass bonding materials with an average particle size of approximately 10 to 30 μm.

[0051] <Sample preparation (comparison example)> In this test, five types of glass powders (Comparative Examples 1 to 5) were prepared by varying the components of the glass composition. Specifically, raw material powders of predetermined compositions were melted at 900 to 1400°C for one hour and then rapidly cooled to obtain glass bodies. Next, these glass bodies were crushed and classified to produce glass bonding materials with an average particle size of approximately 10 to 50 μm.

[0052] The components of the glass compositions in the above glass bonding materials (11 types in total) are shown in Table 1. The units of values ​​in Table 1 are "mol %."

[0053] [Table 1]

[0054] <Evaluation of vitrification> The glass powder prepared above was subjected to powder X-ray diffraction (XRD) to confirm whether it could be vitrified. An X-ray diffractometer (Rigaku Corporation, SmartLab) was used for this measurement. When the XRD pattern obtained by this measurement showed no sharp crystalline peaks and only broad halo peaks, it was determined that the glass had been vitrified. The glass powder was marked with "Good" if it had been vitrified, and marked with "Poor" if it had not been vitrified. Note that Comparative Example 1 was not vitrified, and therefore the tests described below were not performed.

[0055] <Water resistance evaluation (hot water immersion test)> The glass powder thus prepared was press-molded to produce a pellet-shaped glass compact (φ15 mm × thickness 7 mm). The glass compact was then calcined at a temperature (approximately 450°C) sufficient to prevent corner rounding, and then immersed in hot water at 80°C for 24 hours. A weight loss of less than 3% after immersion in hot water was evaluated as "Good," and a weight loss of 3% or more was evaluated as "Poor." The measured values ​​are shown in parentheses.

[0056] <Water resistance evaluation (long-term atmospheric stability test)> The glass powder thus prepared was press-molded to produce a pellet-shaped glass compact (φ15 mm × thickness 7 mm). The glass compact was then calcined at a temperature (approximately 450°C) sufficient to prevent corner rounding, and then allowed to stand in an air environment for one month. A weight increase of less than 1% after exposure to the air environment was marked with a "Good" and a weight increase of 1% or more was marked with a "Poor." For samples with a weight increase of 1% or more, the measured value was entered in parentheses.

[0057] <Thermal expansion coefficient> The glass powder thus prepared was press-molded to produce a pellet-shaped glass compact (φ20 mm × thickness 7 mm). The glass compact was then calcined at a temperature sufficient to prevent corner rounding, yielding a disk-shaped fired body. This disk-shaped fired body was cut into a φ15 mm × 5 mm piece using a diamond cutter, and the thermal expansion coefficient was measured using a thermomechanical analyzer (Rigaku Corporation, ThermoplusEVO2). Specifically, the thermal expansion coefficient was calculated from the average linear expansion between 30°C and 300°C when the temperature was increased from room temperature (25°C) to 1000°C at a constant rate of 10°C / min.

[0058] <Glass transition temperature> The glass powder thus prepared was press-molded to produce a pellet-shaped glass compact (φ20 mm × thickness 7 mm). The glass compact was then calcined at a temperature that did not round the corners, yielding a disk-shaped fired body. This disk-shaped fired body was cut into a φ15 mm × 5 mm size using a diamond cutter, and the glass transition temperature was measured using a thermomechanical analyzer (Rigaku Corporation, ThermoplusEVO2). Specifically, the temperature was raised from room temperature (25°C) to 1000°C at a constant rate of 10°C / min, and the glass transition temperature was measured.

[0059] <Yield point> The glass powder thus prepared was press-molded to produce a pellet-shaped glass compact (φ20 mm × thickness 7 mm). The glass compact was then pre-fired at a temperature that did not round the corners, yielding a disk-shaped fired body. This disk-shaped fired body was cut into a φ15 mm × 5 mm size using a diamond cutter, and the yield point was measured using a thermomechanical analyzer (Rigaku Corporation, ThermoplusEVO2). Specifically, the temperature was raised from room temperature (25°C) to 1000°C at a constant rate of 10°C / min, and the yield point was measured.

[0060] <Evaluation of bonding> The glass powder thus prepared was press-molded to produce a pellet-shaped glass compact (φ20 mm × thickness 7 mm). The pellet-shaped glass compact was placed on a plate-shaped (25 mm × thickness 2 mm) austenitic stainless steel (SUS304) or the like, and heat-treated in air at 400 to 550 °C for 1 hour to obtain a bonded body. The bonded body was then inverted, and a glass bonding material that fell or cracked was marked "X", and a glass bonding material that did not fall or crack was marked "O". In the evaluation of bondability, three inorganic materials were used as bonding targets: pure aluminum (A1050), austenitic stainless steel (SUS304), and oxygen-free copper (C1020). Bondability to each inorganic material was evaluated.

[0061] <Evaluation results> The results of each of the above tests are shown in Table 2. For the overall evaluation, if there was at least one "x" in the vitrification, water resistance, and bondability evaluation items, the result was marked "x," and if there was no "x," the result was marked "good." The water resistance of the glass bonding material was evaluated by a hot water immersion test and a long-term atmospheric stability test. The thermal properties of the glass bonding material were also evaluated by the thermal expansion coefficient, glass transition point, and yield point.

[0062] [Table 2]

[0063] From the above results, it was confirmed that the glass bonding materials of Examples 1 to 6 exhibited good water resistance and bondability. It was confirmed that Comparative Example 1, which contained less than 50 mol% TeO2, did not vitrify. Comparative Examples 2 and 3 contained P2O5 as a constituent component of the glass composition. Comparative Example 2 did not exhibit sufficient water resistance. Comparative Example 3 showed a weight loss rate of less than 3% even after immersion in hot water at 80°C for 24 hours, demonstrating short-term water resistance. However, Comparative Example 3 did not exhibit long-term water resistance of one month or more. Comparative Example 4 is a bismuthate-based glass bonding material containing Bi2O3 as a main constituent. Comparative Example 4 exhibited a significantly reduced thermal expansion coefficient, resulting in significantly poorer bondability. Comparative Example 5 also exhibited a significantly reduced thermal expansion coefficient, resulting in significantly poorer bondability, similar to Comparative Example 4. In contrast, Examples 1 to 6, which contained 50 mol% or more TeO2, exhibited vitrification. These results confirmed that adding ZnO and BaO to a composition containing TeO2 as the main component can achieve both water resistance and bondability. Furthermore, by adding Al2O3, as in Examples 5 and 6, further improvements in water resistance can be expected.

[0064] The above describes preferred embodiments of the present disclosure, but these descriptions are not limiting, and various modifications are possible, such as the numerical values ​​of the blending amounts and additives.

[0065] In the technology disclosed herein, each component and each process mentioned herein may be omitted or combined as appropriate, unless a particular problem arises, and this specification includes the disclosures described in the following sections.

[0066] Item 1: A glass bonding material for low-temperature bonding at 700 ° C or less, wherein the glass composition contained in the glass bonding material contains the following components in oxide terms when the entire glass composition is taken as 100 mol%: TeO2: 50 mol% or more and 85 mol% or less, ZnO: 5 mol% or more and 15 mol% or less, BaO: 1 mol% or more and 40 mol% or less, wherein the total amount of each of the components is 90 mol % or more of the entire glass composition.

[0067] Item 2: The glass bonding material according to item 1, wherein the glass composition further contains Al2O3 in an amount of 10 mol% or less in terms of oxide when the entire glass composition is taken as 100 mol%.

[0068] Item 3: The thermal expansion coefficient of the glass bonding material from 30°C to 300°C is 14 x 10 -6 K -1 ~19×10 -6 K -1 Item 3. The glass bonding material according to item 1 or 2,

[0069] Item 4: The glass bonding material according to any one of Items 1 to 3, having a yield point of 300°C or higher and 500°C or lower.

[0070] Item 5: The glass bonding material according to any one of items 1 to 4, which is intended for metal members.

[0071] Item 6: The metal member has a thermal expansion coefficient of 16 × 10 from 30 ° C to 300 ° C. -6 K -1 ~22×10 -6 K -1 Item 6. The glass bonding material according to item 5, which is a metal member made of a metal material.

[0072] Item 7: The glass bonding material according to item 5 or 6, wherein the metal member is selected from the group consisting of at least aluminum, copper, alloys thereof, and stainless steel.

[0073] Item 8: The glass bonding material according to any one of Items 1 to 7, wherein the glass bonding material does not contain vanadium (V).

[0074] Item 9: A bonded body of a first metal member and a second metal member, characterized in that the bonding portion bonding the two metal members is made of the glass bonding material according to any one of items 1 to 8.

[0075] Item 10: The joined body according to Item 9, wherein either or both of the first metal member and the second metal member are made of a metal member selected from aluminum, copper, alloys thereof, and stainless steel. [Explanation of symbols]

[0076] 1 zygote 10 Glass bonding material 20 Aluminum 21 Austenitic stainless steel

Claims

1. A glass bonding material for low-temperature bonding at 650°C or less, The glass composition contained in the glass bonding material is When the entire glass composition is taken as 100 mol %, the following components are contained in terms of oxides: TeO ２ :50mol% or more and 85mol% or less, ZnO: 5 mol% or more and 15 mol% or less, BaO: 1 mol% or more and 40 mol% or less, and the total amount of each of the components is 90 mol % or more of the entire glass composition.

2. The glass composition contains, in oxide terms, the following when the entire glass composition is taken as 100 mol %: Al ２ O ３ The glass bonding material according to claim 1, further comprising 10 mol% or less of

3. The thermal expansion coefficient of the glass bonding material from 30°C to 300°C is 14 x 10 －６ K －１ ~19 x 10 －６ K －１ The glass bonding material according to claim 1,

4. 2. The glass bonding material according to claim 1, wherein the yield point is 300°C or higher and 500°C or lower.

5. The glass bonding material according to claim 1 , which is intended for a metal member.

6. The metal member has a thermal expansion coefficient of 16×10 from 30° C. to 300° C. －６ K －１ ~22 x 10 －６ K －１ The glass bonding material according to claim 5, which is a metal member made of a metal material.

7. 7. The glass bonding material according to claim 6, wherein the metal member is selected from the group consisting of at least aluminum, copper, alloys thereof, and stainless steel.

8. The glass bonding material according to claim 1 , wherein the glass bonding material does not contain vanadium (V).

9. A joined body of a first metal member and a second metal member, A joined body, characterized in that a joint joining two metal members is made of the glass joining material according to any one of claims 1 to 7.

10. 10. The joined body according to claim 9, wherein either or both of the first metal member and the second metal member are made of a metal member selected from aluminum, copper, alloys thereof, and stainless steel.

Images