Glass powder, sealing material, and sealing material paste

Abstract

The present invention provides: a glass powder which is capable of sealing a high expansion member without containing lead that is harmful to the environment; and a sealing material and a sealing material paste, each of which uses the glass powder.　The glass powder is characterized by containing, as a glass composition, 30-80% by mole of TeO2, 5-30% by mole of B2O3 + WO3, and 0.1-20% by mole of SrO.

Description

Glass powder, sealing material and sealing material paste

[0001] The present invention relates to a glass powder, and more particularly to a glass powder suitable for sealing high-expansion members, and a sealing material and a sealing material paste using the same.

[0002] Glass powder made of low-melting glass is used to seal high-expansion materials (e.g., high-expansion metals, high-expansion ionic crystals, etc.), and the low-melting glass is required to have properties such as chemical durability, mechanical strength, and electrical insulation, depending on the application.

[0003] As a low-melting glass that satisfies these required properties, lead-based glass containing a large amount of PbO has been widely used (see Patent Document 1).

[0004] However, PbO has a problem of having a large environmental impact. For this reason, replacement of lead-based glass with lead-free glass is desired, and various lead-free glasses have been developed. In particular, the bismuth-based glass described in Patent Document 2 and the like is a promising candidate for replacing lead-based glass.

[0005] JP 63-315536 ​​A JP 2000-128574 A

[0006] However, bismuth-based glass has a low thermal expansion coefficient, making it difficult to match it with the thermal expansion coefficient of the high-expansion member. As a result, after sealing the high-expansion member, undue stress remains, which can easily cause cracks or peeling at the interface with the high-expansion member.

[0007] In view of the above, an object of the present invention is to provide a glass powder that is capable of sealing high expansion members without containing lead, which is harmful to the environment, and a sealing material and a sealing material paste that use the same.

[0008] The glass powder of the present invention has a glass composition containing, in mol %, TeO ２ 30-80%, B ２ O ３ +WO ３ 5 to 30% and SrO 0.1 to 20%. ２ O ３ +WO ３ " means B ２ O ３ and W.O.３ means the total amount of

[0009] The glass powder of the present invention preferably contains, in mol %, 0.1 to 40% of MgO+CaO+BaO+ZnO as a glass composition, where "MgO+CaO+BaO+ZnO" means the total amount of MgO, CaO, BaO, and ZnO.

[0010] The glass powder of the present invention has a glass composition of, in mol %, MoO ３ It is preferable that the content is 0.1 to 30%.

[0011] The glass powder of the present invention has a glass composition containing, in mol %, SiO ２ +Al ２ O ３ +La ２ O ３ It is preferable that the content of SiO is 0.1 to 15%. ２ +Al ２ O ３ +La ２ O ３ " means SiO ２ , Al ２ O ３ and La ２ O ３ means the total amount of

[0012] The glass powder of the present invention has a glass composition containing, in mol %, Nb ２ O ５ +CuO+Fe ２ O ３ It is preferable that the content of Nb is 0.1 to 20%. ２ O ５ +CuO+Fe ２ O ３ " means Nb ２ O ５ , CuO and Fe ２ O ３ means the total amount of

[0013] The glass powder of the present invention has a glass composition containing, in mol %, Li ２ O + Na ２ O+K ２ It is preferable that the content of "Li is 0.1 to 20%. ２ O + Na２ O+K ２ "O" means Li ２ O, Na ２ O and K ２ It means the total amount of O.

[0014] The glass powder of the present invention has a thermal expansion coefficient of 100×10 at 30 to 250° C. －７ / ℃~200×10 －７ / °C.

[0015] The sealing material of the present invention is characterized by containing the above-mentioned glass powder.

[0016] The sealing material of the present invention is preferably used for sealing high expansion metals.

[0017] The sealing material of the present invention is preferably used to seal high expansion ionic crystals.

[0018] The sealing material paste of the present invention is characterized by containing the above sealing material and a vehicle.

[0019] The present invention can provide a glass powder capable of sealing high expansion members without containing environmentally harmful lead, and a sealing material and a sealing material paste using the same.

[0020] The glass powder of the present invention contains, in mol %, TeO ２ 30-80%, B ２ O ３ +WO ３ The glass composition is limited as above for the following reasons. In the following description of the content of each component, "%" means "mol %" unless otherwise specified.

[0021] TeO ２ TeO is a component that forms a glass network and improves weather resistance. When glass is sealed to a high-expansion member, TeO is a component that improves the adhesive strength between the glass and the high-expansion member. ２ The content of TeO is 30 to 80%, preferably 40 to 75%, and particularly preferably 43 to 72%. ２If the content of TeO is too low, vitrification becomes difficult. In addition, the adhesive strength between the glass and the high-expansion member tends to decrease, and the glass tends to peel off from the high-expansion member. ２ If the content is too high, the viscosity (softening point, etc.) of the glass increases, making low-temperature sealing difficult and the glass becomes thermally unstable, making it prone to devitrification during melting or firing.

[0022] B ２ O ３ and W.O. ３ is a component that forms a glass network. When glass is sealed to a high-expansion member, it is a component that improves the adhesive strength between the glass and the high-expansion member. ２ O ３ +WO ３ is 5 to 30%, preferably 7 to 28%, and particularly preferably 9 to 26%. ２ O ３ +WO ３ If the amount of B is too small, the adhesive strength between the glass and the high-expansion member is likely to decrease, and the glass is likely to peel off from the high-expansion member. ２ O ３ +WO ３ If the amount of B is too large, the glass becomes thermally unstable and tends to devitrify during melting or firing. Furthermore, the glass tends to undergo phase separation. ２ O ３ and W.O. ３ The content of each component is preferably 0 to 30%, more preferably 1 to 28%, and even more preferably 2 to 26%.

[0023] SrO is a component that broadens the vitrification range and increases the thermal expansion coefficient of glass. The SrO content is 0.1 to 20%, preferably 0.5 to 18%, and particularly preferably 1 to 16%. If the SrO content is too low, the glass becomes thermally unstable and is prone to devitrification during melting or firing. Furthermore, the thermal expansion coefficient of the glass becomes too low. On the other hand, if the SrO content is too high, the glass becomes thermally unstable and is prone to devitrification during melting or firing.

[0024] In addition to the above components, the glass powder of the present invention may contain the following components in its glass composition.

[0025] MgO, CaO, BaO, and ZnO are components that broaden the vitrification range and increase the thermal expansion coefficient of glass. The content of MgO + CaO + BaO + ZnO is preferably 0 to 40%, 0.1 to 40%, 0.1 to 30%, 0.5 to 10%, and particularly preferably 1 to 15%. If the content of MgO + CaO + BaO + ZnO is too high, the glass becomes thermally unstable and is prone to devitrification during melting or firing. Furthermore, the content of each of MgO, CaO, BaO, and ZnO is preferably 0 to 30%, 0.1 to 10%, and particularly preferably 1 to 15%.

[0026] MoO ３ is a component that forms a glass network and improves weather resistance. ３ The content of MoO is preferably 0 to 30%, 0.1 to 30%, 1 to 28%, particularly preferably 3 to 25%. ３ If the content is too high, the glass becomes thermally unstable, the glass is likely to devitrify during melting or firing, and the thermal expansion coefficient of the glass tends to become too high.

[0027] SiO ２ , Al ２ O ３ and La ２ O ３ is a component that improves weather resistance. ２ +Al ２ O ３ +La ２ O ３ is preferably 0 to 15%, 0.1 to 15%, 1 to 13%, particularly preferably 2 to 11%. ２ +Al ２ O ３ +La ２ O ３ If the amount of SiO is too large, the viscosity (softening point, etc.) of the glass increases, making low-temperature sealing difficult and the thermal expansion coefficient of the glass tends to become too low. ２ , Al ２ O ３ and La ２ O ３ The content of each component is preferably 0 to 15%, 0.1 to 15%, 1 to 13%, and particularly preferably 2 to 11%.

[0028] Nb ２ O５ , CuO and Fe ２ O ３ Nb is a component that thermally stabilizes glass. When glass is sealed to a high-expansion member, Nb is a component that improves the adhesive strength between the glass and the high-expansion member. ２ O ５ +CuO+Fe ２ O ３ is preferably 0 to 20%, 0.1 to 20%, 0.5 to 10%, particularly preferably 1 to 5%. ２ O ５ +CuO+Fe ２ O ３ If Nb is too much, the viscosity (softening point, etc.) of the glass becomes high, making it difficult to perform low-temperature sealing, and the thermal expansion coefficient of the glass tends to become too low. ２ O ５ , CuO and Fe ２ O ３ The content of each component is preferably 0 to 20%, 0.1 to 20%, 0.5 to 10%, and particularly preferably 1 to 5%.

[0029] Li ２ O, Na ２ O and K ２ O is a component that reduces the viscosity (softening point, etc.) of the glass. ２ O + Na ２ O+K ２ O is preferably 0 to 20%, 0.1 to 20%, 0.5 to 18%, particularly preferably 1 to 16%. ２ O + Na ２ O+K ２ If there is too much O, the glass becomes thermally unstable and is prone to devitrification during melting or firing. ２ O, Na ２ O and K ２ The content of each O component is preferably 0 to 20%, 0.1 to 20%, 0.5 to 18%, and particularly preferably 1 to 16%.

[0030] GeO ２ , NiO, Y ２ O ３ , P ２ O ５ , CeO ２ , TiO ２ , V ２ O５ , Sb ２ O ３ , ZrO ２ are components that thermally stabilize the glass and suppress devitrification, and each can be added up to less than 2%. If the content of these components is too high, the glass becomes thermally unstable and is prone to devitrification during melting or firing.

[0031] For environmental reasons, the glass powder of the present invention preferably contains substantially no PbO. Here, "substantially no PbO" refers to a glass composition containing 0.1% or less PbO.

[0032] The sealing material of the present invention contains the above-mentioned glass powder. The sealing material of the present invention may also contain a refractory filler powder in order to improve the mechanical strength or adjust the thermal expansion coefficient.

[0033] The refractory filler powder is Zr ２ WO ４ (P.O. ４ ) ２ It is preferable that Zr ２ WO ４ (P.O. ４ ) ２ is unlikely to react with the glass powder, and when the thermal expansion coefficient of the sealing material is too high, it can efficiently lower the thermal expansion coefficient of the sealing material.

[0034] The sealing material of the present invention further contains Zr as the refractory filler powder. ２ WO ４ (P.O. ４ ) ２ Other refractory filler powders may also be used. Other refractory filler powders include NbZr(PO ４ ) ３ , Zr ２ MoO ４ (P.O. ４ ) ２ , Hf ２ WO ４ (P.O. ４ ) ２ , Hf ２ MoO ４ (P.O. ４ ) ２, zirconium phosphate, zircon, zirconia, tin oxide, aluminum titanate, quartz, β-spodumene, mullite, titania, quartz glass, β-eucryptite, β-quartz, willemite, cordierite, Sr ０．５ Zr ２ (P.O. ４ ) ３ Powders consisting of the above can be used alone or in combination of two or more.

[0035] The refractory filler powder is preferably substantially spherical. This makes it difficult for the refractory filler powder to inhibit the flowability of the glass powder when the glass powder softens, resulting in improved flowability of the glass powder. Furthermore, a smooth glaze layer is easily obtained. Even if a portion of the refractory filler powder is exposed on the surface of the glaze layer, the refractory filler powder's substantially spherical shape disperses stress in this portion. Furthermore, even if an object to be sealed contacts the glaze layer during sealing, undue stress is unlikely to be applied to the object, making it easier to ensure airtightness. In the present invention, the term "substantially spherical" does not necessarily refer to a perfect sphere, but rather refers to a refractory filler powder in which the value obtained by dividing the shortest diameter passing through the center of gravity of the refractory filler powder by the longest diameter is 0.5 or more, preferably 0.7 or more.

[0036] The particle size of the refractory filler powder is an average particle size D ５０ In the present invention, it is preferable to use particles having an average particle diameter D ５０ " refers to a value measured using a laser diffraction device, and represents the particle size at which the integrated amount accumulates to 50% from the smallest particle on a volume-based cumulative particle size distribution curve measured using a laser diffraction method.

[0037] The glass transition point of the sealing material of the present invention is preferably 450°C or lower, particularly 430°C or lower. If the glass transition point is too high, the viscosity of the glass increases, and the sealing temperature tends to rise in order to achieve a predetermined fluidity. The lower limit of the glass transition point is not particularly limited, but in reality it is 250°C or higher. Here, the "glass transition point" refers to the average particle diameter D ５０The glass transition temperature (Tg) is measured using a sealing material having a thickness of 0.5 to 20 μm as a measurement sample, using a macro-type differential thermal analyzer. The measurement is started at room temperature, and the temperature is increased at a rate of 10°C / min. The glass transition temperature measured using a macro-type differential thermal analyzer refers to the temperature of the first inflection point in the measurement curve.

[0038] The softening point of the sealing material of the present invention is preferably 520°C or less, 500°C or less, particularly 480°C or less. If the softening point is too high, the viscosity of the glass increases, and the sealing temperature tends to rise in order to achieve a predetermined fluidity. The lower limit of the softening point is not particularly limited, but in reality it is 300°C or more. Here, the "softening point" refers to the average particle diameter D ５０ The softening point is a value measured by a macro-type differential thermal analyzer using a sealing material having a thickness of 0.5 to 20 μm as a measurement sample. The measurement is started at room temperature and the temperature is increased at a rate of 10°C / min. The softening point measured by the macro-type differential thermal analyzer refers to the temperature of the fourth inflection point in the measurement curve.

[0039] The thermal expansion coefficient (30 to 250°C) of the sealing material of the present invention is 100 x 10 －７ / ℃~200×10 －７ / ℃, 110 × 10 －７ / ℃~190×10 －７ / °C, especially 120 x 10 －７ / ℃~180×10 －７ / ° C. If the thermal expansion coefficient is too low or too high, the difference in thermal expansion with the material to be sealed (high-expansion member) makes the sealed portion more susceptible to damage during or after sealing.

[0040] The sealing material of the present invention having the above-mentioned properties is particularly suitable for sealing high-expansion metals such as stainless steel, iron, nickel-chromium steel, and copper, and high-expansion ionic crystals such as calcium fluoride.

[0041] Next, an example of a method for producing the glass powder of the present invention and a method for using the glass powder of the present invention as a sealing material will be described.

[0042] First, raw material powders prepared to have the above composition are melted at 800 to 1400°C for 1 to 2 hours until a homogeneous glass is obtained. Next, the molten glass is formed into a film or the like, and then crushed and classified to produce the glass powder (sealing material) of the present invention. The average particle diameter D of the glass powder is 1.5 mm. ５０ The particle size is preferably about 1 to 20 μm. If necessary, various refractory filler powders may be added to the glass powder.

[0043] Next, a vehicle is added to the glass powder (sealing material) and kneaded to prepare a glass paste (sealing material paste). The vehicle mainly consists of an organic solvent and a resin, and the resin is added to adjust the viscosity of the paste. If necessary, a surfactant, a thickener, etc. can also be added.

[0044] The organic solvent preferably has a low boiling point (for example, a boiling point of 300°C or less), leaves little residue after firing, and does not alter the glass, and its content is preferably 10 to 40% by mass. As the organic solvent, propylene carbonate, toluene, N,N'-dimethylformamide (DMF), 1,3-dimethyl-2-imidazolidinone (DMI), dimethyl carbonate, butyl carbitol acetate (BCA), isoamyl acetate, dimethyl sulfoxide, acetone, methyl ethyl ketone, etc. are preferably used. Furthermore, it is even more preferable to use a higher alcohol as the organic solvent. Since higher alcohols themselves have viscosity, they can be made into a paste without adding a resin to the vehicle. Furthermore, pentanediol and its derivatives, specifically diethylpentanediol (C ９ H ２０ O ２ ) also has excellent viscosity and can be used as a solvent.

[0045] The resin preferably has a low decomposition temperature, leaves little residue after firing, and is unlikely to alter the glass, and its content is preferably 0.1 to 20% by mass. As the resin, nitrocellulose, polyethylene glycol derivatives, polyethylene carbonate, acrylic esters (acrylic resins), etc. are preferably used.

[0046] Next, the glass paste (sealing material paste) is applied to the sealing locations of the objects to be sealed, which are made of a high-expansion material, using an applicator such as a dispenser or a screen printer, dried, and then glazed at 350 to 500° C. Thereafter, the objects to be sealed are brought into contact with each other and heat-treated at 400 to 580° C., whereby the glass powder softens and flows, sealing the two together.

[0047] The glass powder of the present invention can be used for purposes other than sealing, such as coating and filling. It can also be used in forms other than a paste, specifically in the form of a powder, a green sheet, a tablet (a press frit which is a sintered body of the powder), or the like.

[0048] The present invention will be described in detail based on examples. Tables 1 to 3 show examples of the present invention (samples Nos. 1 to 13, 16 to 20) and comparative examples (samples Nos. 14 and 15).

[0049]

[0050]

[0051]

[0052] First, glass raw materials such as various oxides and carbonates were mixed to obtain the glass compositions shown in the table to prepare a glass batch, and then the glass batch was placed in a platinum crucible and melted in the atmosphere at 800 to 1400°C for 1 to 2 hours. Next, a portion of the molten glass was poured into a stainless steel mold as a sample for measuring the thermal expansion coefficient, and the remaining molten glass was formed into a film using a water-cooled roller. The film-like glass was pulverized in a ball mill and then passed through a sieve with an opening of 75 μm to measure the average particle diameter D ５０ A glass powder having a particle size of about 10 μm was obtained.

[0053] The glass transition point, thermal expansion coefficient, softening point, fluidity, and adhesiveness to the high-expansion member were evaluated for samples No. 1 to 20.

[0054] The thermal expansion coefficient was measured by measuring the above-mentioned sample for measuring the thermal expansion coefficient in the temperature range of 30 to 250°C using a TMA device.

[0055] The glass transition point and softening point were measured using a macro differential thermal analyzer, and the value at the first inflection point in the measurement curve was taken as the glass transition point, and the value at the fourth inflection point was taken as the softening point. The measurement was carried out in air at a heating rate of 10°C / min, starting from room temperature.

[0056] The flowability was evaluated as follows: A weight corresponding to the density of the glass powder was placed in a mold with a diameter of 20 mm, press-molded, and then fired for 10 minutes at (softening point + 50°C) on a substrate made of a high-expansion material listed in the table. Fired bodies with a flow diameter of 19 mm or more were evaluated as "Good," and those with a flow diameter of less than 19 mm were evaluated as "Poor."

[0057] The adhesion to the high-expansion member was evaluated as follows. A weight corresponding to the density of the glass powder sample was placed in a mold with a diameter of 20 mm and press-molded. The sample was then fired for 10 minutes at (softening point + 50°C) on a substrate made of the high-expansion member listed in the table. After firing, both ends of the substrate were hung on beams, and the fired body was placed facing downward so that its own weight was applied to the fired body. If the fired body did not peel off from the substrate even after 24 hours, it was evaluated as "Good", and if it peeled off and fell, it was evaluated as "Poor".

[0058] As is clear from the table, samples Nos. 1 to 13 and 16 to 20, which are examples of the present invention, were excellent in fluidity and adhesion to the high-expansion member. On the other hand, sample No. 14, which is a comparative example, had excellent adhesion to the high-expansion member. ２ The comparative sample No. 15 did not vitrify because the content of B was low. ２ O ３ and W.O. ３ Since it did not contain , the adhesion to the high expansion member was poor.

Claims

1. The glass composition is, in mol%, TeO ２ 30-80%, B ２ O ３ +W.O. ３ 5 to 30% and SrO 2 0.1 to 20%.

2. The glass powder according to claim 1, characterized in that the glass composition contains, in mol %, 0.1 to 40% of MgO+CaO+BaO+ZnO.

3. The glass composition is, in mole percent, MoO ３ 3. The glass powder according to claim 1, wherein the content is 0.1 to 30%.

4. The glass composition, in mole percent, is SiO ２ +Al ２ O ３ +La ２ O ３ 3. The glass powder according to claim 1, wherein the content is 0.1 to 15%.

5. The glass composition is, in mole percent, Nb ２ O ５ +CuO+Fe ２ O ３ 3. The glass powder according to claim 1, wherein the content is 0.1 to 20%.

6. The glass composition is, in mol%, Li ２ O+Na ２ O+K ２ 3. The glass powder according to claim 1, further comprising 0.1 to 20% O.

7. The thermal expansion coefficient at 30 to 250°C is 100 x 10 －７ / ℃~200×10 －７ 3. The glass powder according to claim 1, wherein the glass powder has a viscosity of 1000:1 or 1000:

1.

8. A sealing material comprising the glass powder according to claim 1.

9. The sealing material according to claim 8, which is used for sealing high expansion metals.

10. The sealing material according to claim 8, which is used for sealing high expansion ionic crystals.

11. A sealing material paste comprising the sealing material according to any one of claims 8 to 10 and a vehicle.

Images