Glass diaphragm, method for manufacturing glass diaphragm, acoustic device, and glass for diaphragm

Abstract

A glass diaphragm according to the present invention is characterized by comprising a vibrating part having a thickness t of 5-2,000 μm, wherein the vibrating part is composed of a glass containing, as a glass composition, 40-80 mol% of SiO2, 5-25 mol% of Al2O3, 0-30 mol% of B2O3, 0-25 mol% of Li2O, 5-25 mol% of Na2O, 0-25 mol% of K2O, 0-20 mol% of MgO, 0-15 mol% of ZnO, and 0-15 mol% of P2O5.

Description

Glass diaphragm, manufacturing method of glass diaphragm, acoustic device, glass for diaphragm

[0001] The present invention relates to a glass diaphragm, a method for manufacturing a glass diaphragm, an acoustic device, and glass for a diaphragm.

[0002] Conventionally, various materials, such as metal, synthetic resin, wood, or paper, have been used for the diaphragms of acoustic devices such as speakers, headphones, and microphones. Various properties are required of diaphragm materials to achieve good sound quality, and it is considered preferable for the diaphragm material to have a high specific elastic modulus and internal friction, for example. From this perspective, the use of glass materials has been considered as materials with relatively high internal friction (for example, Patent Document 1).

[0003] JP 2015-065649 A

[0004] However, Patent Document 1 did not specifically consider what glass composition is suitable for the diaphragm, meaning that there is still room for improvement in conventional glass diaphragms.

[0005] An object of the present invention is to provide a glass diaphragm and an acoustic device having excellent acoustic properties, as well as a method for producing a glass diaphragm and glass for a diaphragm for obtaining these.

[0006] First aspect of the present invention: The glass vibration plate of the present invention has a vibration part having a thickness t of 5 to 2000 μm, and the vibration part has a glass composition containing, in mol %, SiO ２ 40-80%, Al ２ O ３ 5-25%, B ２ O ３ 0-30%, Li ２ O 0-25%, Na ２ O 5-25%, K ２ O 0-25%, MgO 0-20%, ZnO 0-15%, P ２ O ５ The glass is characterized by being composed of a glass containing 0 to 15% of SiO 2 .

[0007] Second aspect of the present invention: In the glass diaphragm of the present invention according to the above aspect, the vibrating portion preferably has a three-dimensional shape selected from the group consisting of a cone shape, a trumpet shape, a dome shape, and a curved plate shape.

[0008] Third aspect of the present invention: In the glass diaphragm of any of the above aspects of the present invention, the internal friction of the glass constituting the vibration part is 1.0 × 10 －３ It is preferable that this is equal to or greater than this.

[0009] Fourth aspect of the present invention: In the glass diaphragm of any of the above aspects of the present invention, the specific elastic modulus of the glass constituting the vibration part is 25 GPa cm ３ / g or more is preferred.

[0010] Fifth aspect of the present invention: In the glass vibration plate of any of the above aspects of the present invention, the glass constituting the vibration part comprises a compressive stress layer having compressive stress on its surface and a tensile stress layer having tensile stress inside the compressive stress layer, and the maximum compressive stress value CS of the outermost surface of the compressive stress layer is 50 to 1500 MPa, and the ratio DOL / t of the stress depth DOL to the thickness t of the compressive stress layer is preferably 0.001 to 0.25.

[0011] Sixth aspect of the present invention: In the glass vibration plate of any of the above aspects of the present invention, the thickness t of the vibration part is 5 to 70 μm, the depth DOL of the compressive stress layer is 15 μm or less, and the maximum compressive stress value CS is 600 to 1300 MPa. It is preferable that CS / DOL ≧ 40 MPa / μm is satisfied.

[0012] Seventh aspect of the present invention: In the glass diaphragm of any of the above aspects of the present invention, it is preferable that the average transmittance at wavelengths of 400 nm to 700 nm, calculated based on a plate thickness of 1 mm, of the diaphragm is 85% or more.

[0013] Eighth aspect of the present invention: In the glass vibration plate of any of the above aspects of the present invention, the vibration part has a glass composition containing Fe ２ O ３ , TiO ２ , CeO ２ , W.O. ３ , NiO, Cr ２ O ３ , CuO, and Co ３O ４ It is preferable that at least one of the above is contained in an amount of 10 ppm or more in terms of mol %.

[0014] Ninth aspect of the present invention: In the glass diaphragm of any of the above aspects of the present invention, it is preferable that the internal stress of the glass constituting the vibration part is less than 10 MPa.

[0015] Tenth aspect of the present invention: In the glass diaphragm of any of the above aspects of the present invention, the vibrating portion preferably has a flat plate shape.

[0016] An eleventh aspect of the present invention: An acoustic device of the present invention is characterized by comprising a glass diaphragm according to any of the above aspects, and a driving unit that vibrates the vibration portion of the glass diaphragm to generate sound waves.

[0017] A twelfth aspect of the present invention: In the acoustic device of the above aspect, it is preferable that the glass diaphragm is colored glass, and the acoustic device further comprises a light source unit that irradiates the glass diaphragm with colored light.

[0018] Thirteenth aspect of the present invention: The method for manufacturing a glass vibration plate of the present invention is to produce a glass vibration plate having a plate thickness of 5 to 1000 μm and a glass composition containing, in mol %, SiO ２ 40-80%, Al ２ O ３ 5-25%, B ２ O ３ 0-30%, Li ２ O 0-25%, Na ２ O 5-25%, K ２ O 0-25%, MgO 0-20%, ZnO 0-15%, P ２ O ５ The method is characterized by comprising the steps of: preparing glass for vibration plates containing 0 to 15% of cellulose acetate; performing a cutting process to cut the glass for vibration plates into glass plates of a predetermined contour; and performing a shape processing process to process the cut glass plates into a three-dimensional shape.

[0019] A fourteenth aspect of the present invention: In the method for manufacturing a glass vibration plate of the present invention according to the above aspect, it is preferable to further include a step of subjecting the three-dimensionally shaped glass that has been subjected to the shape processing treatment to an ion exchange treatment.

[0020] 15th aspect of the present invention: In any of the above aspects of the manufacturing method of the glass vibration plate of the present invention, it is preferable that the cutting process is performed by scanning laser light along the predetermined contour, and the shape processing process is performed by heating and press-molding the plate glass.

[0021] Sixteenth aspect of the present invention: The glass for a diaphragm of the present invention has a plate thickness of 5 to 200 μm and a glass composition containing, in mol %, SiO ２ 40-80%, Al ２ O ３ 5-25%, B ２ O ３ 0-30%, Li ２ O 0-25%, Na ２ O 5-25%, K ２ O 0-25%, MgO 0-20%, ZnO 0-15%, P ２ O ５ It is characterized by containing 0 to 15%.

[0022] The glass diaphragm, the method for manufacturing the glass diaphragm, the acoustic device, and the glass for the diaphragm of the present invention provide excellent acoustic characteristics.

[0023] FIG. 1 is a schematic cross-sectional view of an acoustic device according to one embodiment of the present invention. FIG. 2 is a schematic cross-sectional view of a glass diaphragm having a conical vibrating portion according to one embodiment of the present invention. FIG. 3 is a schematic plan view of a glass diaphragm having a conical vibrating portion according to one embodiment of the present invention. FIG. 4 is a schematic cross-sectional view of a glass diaphragm having a trumpet-shaped vibrating portion according to one embodiment of the present invention. FIG. 5 is a schematic plan view of a glass diaphragm having a trumpet-shaped vibrating portion according to one embodiment of the present invention. FIG. 6 is a schematic cross-sectional view of a glass diaphragm having a dome-shaped vibrating portion according to one embodiment of the present invention. FIG. 7 is a schematic plan view of a glass diaphragm having a dome-shaped vibrating portion according to one embodiment of the present invention. FIG. 8 is a flow chart showing a method for manufacturing a glass diaphragm according to one embodiment of the present invention. FIG. 9 is a schematic perspective view of a glass diaphragm having a bent-plate-shaped vibrating portion according to one embodiment of the present invention.

[0024] <Acoustic Device> Fig. 1 is a schematic cross-sectional view of an acoustic device 1 according to an embodiment of the present invention. The acoustic device 1 in this embodiment is a so-called speaker device. It includes a glass diaphragm 10 and a driving unit 20. The driving unit 20 is connected to the glass diaphragm 10 to vibrate the glass diaphragm 10, and typically includes a voice coil, a magnet, a damper, etc.

[0025] <Glass Vibration Plate> The glass vibration plate 10 of the present invention includes a vibration portion 11. The vibration portion 11 is a portion that is vibrated by a driving portion 20 to generate sound waves, and may also be referred to as a diaphragm. In addition to the vibration portion 11, the glass vibration plate 10 may also include a connection portion 12 for connecting to other components, an edge portion 13, a center dome 14, etc. The vibration portion 11, the connection portion 12, the edge portion 13, and the center dome 14 may be integrally formed from glass. Alternatively, the glass vibration plate 10 may be formed only from the vibration portion 11.

[0026] The vibrating unit 11 in this embodiment has a three-dimensional shape. Figures 2 and 3 illustrate a case where the vibrating unit 11a is conical. The glass diaphragm 10a is composed only of the vibrating unit 11a. The vibrating unit 11 can also be configured in a trumpet shape (Figures 4 and 5), a dome shape (Figures 6 and 7), a mortar shape, or other shapes. The outline shape of the vibrating unit 11 in a plan view is typically a perfect circle or an ellipse. Furthermore, when the vibrating unit 11 is configured separately from the center dome, the vibrating unit 11 has an opening in the center. The outer diameter of the vibrating unit 11 in a plan view may be determined depending on the application, but may be, for example, 20 mm to 400 mm for speaker applications, 20 mm to 60 mm for headphones, and 4 mm to 15 mm for earphone applications.

[0027] The glass diaphragm 10 of the present invention includes a vibrating portion 11 having a shape disclosed in this specification from a bird's-eye view. For example, a glass diaphragm 10 having a minute uneven shape (a wave shape, a groove, a rib) or a patterned shape, or a glass diaphragm having a minutely processed shape in part, which has a shape disclosed in this specification from a macroscopic view, is included in the concept of the present invention.

[0028] The vibrating section 11 has a thickness t, and the lower limit of the range of t is, for example, 5 μm or more, preferably 10 μm or more, 15 μm or more, 20 μm or more, or 25 μm or more, and the upper limit is, for example, 2000 μm or less, preferably 1000 μm or less, 500 μm or less, 200 μm or less, 100 μm or less, 80 μm or less, 60 μm or less, 50 μm or less, or 40 μm or less. The thickness t may be changed depending on the desired sound quality, but if it is too large, it tends to be difficult to control the vibration and control the sound quality. Furthermore, if the thickness t is too small, sufficient strength cannot be obtained, increasing the risk of breakage. The vibrating section 11 preferably has a uniform thickness. The thickness of the vibrating section 11 may vary partially.

[0029] The vibration section 11 can be made of glass, for example, non-tempered glass or tempered glass. The vibration section 11 of the present invention has a glass composition containing, in mol %, SiO ２ 40-80%, Al ２ O ３ 5-25%, B ２ O ３ 0-30%, Li ２ O 0-25%, Na ２ O 5-25%, K ２ O 0-25%, MgO 0-20%, ZnO 0-15%, P ２ O ５ In the present invention, when the vibration section 11 is made of tempered glass, the glass composition of the center in the thickness direction, i.e., the region that has not been ion-exchanged, refers to the glass composition of the tempered glass.

[0030] By using such a glass composition, it is possible to obtain characteristics such as internal friction that are suitable for the glass diaphragm 10. Furthermore, by using such a glass composition, it is possible to obtain high ion exchangeability, and it is possible to obtain a tempered glass glass diaphragm 10 that combines high strength and good acoustic characteristics. When the vibration part 11 is made of tempered glass, a compressive stress layer is formed on the surface and a tensile stress layer is formed inside.

[0031] The reasons for limiting the content range of each component in the above glass composition are as follows: In the explanation of the content range of each component, % indicates mol % unless otherwise specified.

[0032] SiO ２ is a component that forms the glass network. ２ If the content of SiO is too small, vitrification becomes difficult, and the thermal expansion coefficient becomes too high, which tends to reduce the thermal shock resistance. ２ The preferred lower limit range of SiO is, in mole %, 40% or more, 45% or more, 50% or more, 55% or more, 57% or more, 59% or more, 61% or more, particularly 63% or more. ２ If the content of SiO is too high, the melting property and moldability tend to decrease, and the thermal expansion coefficient becomes too low, making it difficult to match the thermal expansion coefficient of the surrounding material. ２ The preferred upper limit ranges of are 80% or less, 75% or less, 73% or less, 71% or less, and 69% or less.

[0033] Al ２ O ３ is a component that enhances ion exchange performance, and also enhances the strain point, Young's modulus, fracture toughness, and Vickers hardness. ２ O ３ The preferred lower limit range of Al is, in mol %, 5% or more, 6% or more, 7% or more, 8% or more, 8.5% or more, 9% or more, particularly 9.2% or more. ２ O ３ If the content is too high, the high-temperature viscosity increases, and melting property and formability tend to decrease. In addition, devitrification crystals tend to precipitate in the glass, making it difficult to form it into a plate by the overflow downdraw method or the like. In particular, when an alumina-based refractory is used as the formed body refractory and a glass plate is formed by the overflow downdraw method, devitrification crystals of spinel tend to precipitate at the interface with the alumina-based refractory. Furthermore, acid resistance also decreases, making it difficult to apply to an acid treatment process. Therefore, Al ２ O ３ The preferred upper limit range of is 25% or less, 23% or less, 20% or less, 18% or less, 16% or less, 15% or less, 14% or less, 13% or less, 12.5% ​​or less, particularly 12% or less.

[0034] B ２ O ３ is a component that reduces the high-temperature viscosity and density, stabilizes the glass, makes it difficult for crystals to precipitate, and lowers the liquidus temperature. It is also a component that suppresses the Young's modulus and increases the bending strength and crack resistance. However, B ２ O ３ If the content of B is too high, the ion exchange treatment tends to cause surface discoloration called fading, reduce water resistance, and reduce the compressive stress value of the compressive stress layer. ２ O ３ The preferred lower limit range of is, in mole %, 0% or more, 0.01% or more, 0.02% or more, 0.1% or more, or 0.3% or more, and the preferred upper limit range is 30% or less, 25% or less, 22% or less, 20% or less, 15% or less, particularly 10% or less. ２ O ３ The content of B can be more preferably 0.2 to 5%, and more preferably 0.3 to 1%. In addition, from the viewpoint of improving chemical durability for the purpose of suppressing defects during etching treatment, B ２ O ３ The lower limit range of the content can be preferably 1% or more, 1.5% or more, or 2% or more, and the upper limit range can be 5% or less, 4.5% or less, 4% or less, or 3% or less.

[0035] Li ２ O is a component that reduces high-temperature viscosity and improves meltability and moldability. ２ O is an ion exchange component, and is a component that exchanges Li ions contained in the glass with ions in the molten salt to obtain deep surface compressive stress. ２ The preferred lower limit range of O is 0% or more, and 0.1% or more, in mole percent. ２ The upper limit of the O content is preferably 25% or less, more preferably 20% or less.

[0036] Na ２ O is a component that increases the internal friction of the glass. ２ O is an ion exchange component and also a component that reduces high-temperature viscosity and improves meltability and moldability. ２O is also a component that improves devitrification resistance and reaction devitrification resistance with refractory molded bodies, particularly alumina-based refractories. ２ If the O content is too low, the internal friction decreases, the melting property decreases, the thermal expansion coefficient decreases too much, and the ion exchange rate tends to decrease. ２ The preferred lower limit range of O is, in mole %, 5% or more, 6% or more, 7% or more, 8% or more, 9% or more, 10% or more, 11% or more, 12% or more, 13% or more, 14% or more, particularly 15% or more. ２ If the O content is too high, the viscosity at which phase separation occurs tends to decrease. In addition, the acid resistance may decrease, and the balance of the components in the glass composition may be lost, which may result in a decrease in devitrification resistance. ２ The preferred upper limit range of O is 25% or less, 23% or less, or 21% or less.

[0037] K ２ O is a component that reduces high-temperature viscosity and improves meltability and moldability. It also improves devitrification resistance and increases Vickers hardness. ２ If the O content is too high, the viscosity at which phase separation occurs tends to decrease. In addition, the acid resistance tends to decrease, and the balance of the components in the glass composition tends to be lost, which in turn tends to decrease the devitrification resistance. ２ The preferred lower limit range of O, in mole %, is 0% or more, 0.01% or more, 0.02% or more, 0.05% or more, 0.1% or more, 0.5% or more, 1% or more, 1.5% or more, 2% or more, 2.5% or more, and particularly 2.8% or more, and the preferred upper limit range is 25% or less, 20% or less, 15% or less, 10% or less, 9% or less, 8% or less, 7% or less, 6% or less, 5% or less, 4.5% or less, 4% or less, and particularly 3.5% or less.

[0038] MgO is a component that reduces high-temperature viscosity, improves meltability and formability, and increases strain point and Young's modulus. Among alkaline earth metal oxides, it is a component that is highly effective in improving ion exchange performance. However, if the MgO content is too high, the density and thermal expansion coefficient tend to increase, and the glass is prone to devitrification. Therefore, the preferred upper limit of MgO is 20% or less, 12% or less, 10% or less, 8% or less, 6% or less, and particularly 5% or less. When MgO is incorporated into the glass composition, the preferred lower limit of MgO is, in mole percent, 0% or more, 0.1% or more, 0.5% or more, 1% or more, and particularly 2% or more.

[0039] ZnO is a component that reduces high-temperature viscosity without reducing low-temperature viscosity. ZnO also enhances ion exchange performance, and is particularly effective in increasing compressive stress. However, if the ZnO content is too high, the glass tends to undergo phase separation, reduce devitrification resistance, increase density, and reduce the stress depth of the compressive stress layer. Therefore, the ZnO content is preferably 0 to 15%, 0 to 10%, 0 to 6%, 0 to 5%, 0 to 1%, or 0 to 0.5%, particularly preferably 0 to less than 0.1%, in mole percent.

[0040] P ２ O ５ is a component that enhances the ion exchange performance, and in particular, is a component that increases the stress depth of the compressive stress layer. ２ O ５ If the content of P is too high, the Young's modulus is likely to decrease and the glass is likely to undergo phase separation. ２ O ５ The preferred upper limit range, in mole %, is 15% or less, 10% or less, 8% or less, 6% or less, 4% or less, 2% or less, 1% or less, particularly less than 0.1%.

[0041] In addition to the above components, the glass constituting the vibration section 11 may contain, for example, the following components as a glass composition.

[0042] Compared with other components, CaO has a significant effect of reducing high-temperature viscosity, improving meltability and formability, and increasing the strain point and Young's modulus without reducing devitrification resistance. The CaO content is preferably 0 to 10%. However, if the CaO content is too high, the density and thermal expansion coefficient increase, and the component balance of the glass composition is lost, making the glass more susceptible to devitrification and the ion exchange performance more likely to decrease. Therefore, the preferred CaO content is, in mole percent, 0 to 5%, 0.01 to 4%, 0.1 to 3%, and particularly 1 to 2.5%.

[0043] SrO is a component that reduces high-temperature viscosity, improves meltability and formability, and increases strain point and Young's modulus without reducing devitrification resistance. However, if the SrO content is too high, the density and thermal expansion coefficient increase, the ion exchange performance decreases, and the component balance of the glass composition is lost, making the glass more susceptible to devitrification. The preferred range of SrO content is 0 to 5%, 0 to 3%, 0 to 1%, and particularly 0 to less than 0.1%, in mole percent.

[0044] BaO is a component that reduces high-temperature viscosity, improves meltability and formability, and increases strain point and Young's modulus without reducing devitrification resistance. However, if the BaO content is too high, the density and thermal expansion coefficient increase, the ion exchange performance decreases, and the glass composition loses its component balance, making the glass more susceptible to devitrification. The preferred BaO content range, in mole percent, is 0 to 5%, 0 to 3%, 0 to 1%, and particularly 0 to less than 0.1%.

[0045] ZrO ２ is a component that increases the viscosity near the liquidus viscosity and the strain point, and also significantly increases the ion exchange performance, but if its content is too high, there is a risk that the devitrification resistance will be significantly reduced and the density will be too high. ２ The preferred upper limit range of ZrO in mol % is 10% or less, 8% or less, 6% or less, particularly 5% or less. ２ In this case, ZrO ２ The preferred lower limit range of is 0.001% or more, 0.01% or more, 0.5% or more, particularly 1% or more.

[0046] SnO ２ is a component useful as a fining agent. ２ The preferred content range of is 0 to 10,000 ppm (1%), 0 to 7,000 ppm, particularly 50 to 6,000 ppm.

[0047] As a fining agent, Cl, SO ３ One or more elements selected from the group consisting of Cl, SO, and F may be incorporated into the glass in an amount of 0 to 30,000 ppm (3%). ３ From the viewpoint of adequately obtaining the fining effect, the content of "Cl + SO" is preferably 0 to 10,000 ppm, 50 to 5,000 ppm, 80 to 4,000 ppm, 100 to 3,000 ppm, particularly preferably 300 to 3,000 ppm. ３ " is Cl and SO ３ Refers to the total amount of

[0048] The preferred range of Cl content is 0 to 1500 ppm, 0 to 1200 ppm, 0 to 800 ppm, 0 to 500 ppm, particularly 50 to 300 ppm.

[0049] SO ３ The preferred content range is 0 to 1000 ppm, 0 to 800 ppm, particularly 10 to 500 ppm.

[0050] <Colored Glass Diaphragm> In some cases, it is preferable to color the vibration part 11 of the glass diaphragm 10 from the viewpoint of design, concealment, visibility during assembly work, etc. In this case, Fe is used as a coloring agent. ２ O ３ , TiO ２ , CeO ２ , W.O. ３ , NiO, Cr ２ O ３ , CuO, and Co ３ O ４ At least one of the above may be incorporated into the glass in a total amount of 10 ppm or more. By including these components in the glass, the glass can be colored.

[0051] Nd ２ O ３ , La ２ O ３The rare earth oxides such as Nd are components that increase the Young's modulus, and when a complementary color is added, the color disappears, making it possible to control the color of the glass. ２ O ３ and La ２ O ３ may be contained alone or in a combined amount of 0% or more, 0.001% or more, preferably 0.01% or more, 0.05% or more, or 0.1% or more. ２ O ３ , La ２ O ３ The raw material itself is expensive, and when introduced in a large amount, the devitrification resistance is likely to decrease. ２ O ３ , La ２ O ３ The upper limit of the content of each of these elements, either singly or in combination, is preferably 4% or less, 3% or less, 2% or less, 1% or less, particularly preferably 0.5% or less.

[0052] When the vibration section 11 is made of colored glass, it can have a color tone such as black, brown, amber, white, blue, or dark blue. Furthermore, the vibration section 11 made of colored glass preferably has an average transmittance at wavelengths of 400 nm to 700 nm, calculated as a plate thickness of 1 mm, of 90% or less, 80% or less, 70% or less, 60% or less, 55% or less, or 50% or less. By achieving such optical characteristics, the optical concealment of the vibration section 11 is improved, making it easier to provide a design in which the internal structure of the acoustic device 1 is concealed. Since diaphragms in conventional acoustic devices have often been made of opaque materials, it is preferable for users who prefer traditional designs to use a vibration section 11 with such a low average transmittance and a glass diaphragm 10 equipped with the same.

[0053] <Colorless Glass Diaphragm> On the other hand, there are cases where it is preferable to use colorless and transparent glass for the vibration part 11 from the viewpoint of design or functionality. When the vibration part 11 is made of colorless and transparent glass, it is preferable to limit the content of coloring components to a low level. In this case, Fe ２ O ３ , TiO ２ , CeO ２ , W.O. ３ , NiO, Cr ２O ３ , CuO, and Co ３ O ４ It is preferable to limit the total amount of the coloring components to less than 10,000 ppm. In some cases, glass with high transparency is preferred from the viewpoint of design, and by limiting the content of the coloring components in this way, it is possible to obtain a vibration section 11 with high transparency.

[0054] When the vibrating section 11 is made of colorless glass, the average transmittance at wavelengths of 400 nm to 700 nm, calculated as a plate thickness of 1 mm, is preferably 85% or more, more preferably 88% or more, 89% or more, or 90% or more. By achieving such optical characteristics, it is possible to obtain a glass diaphragm 10 with a highly transparent design and an acoustic device 1 equipped with the same.

[0055] <Glass Characteristics> The internal friction of the glass constituting the vibrating part 11 is preferably 1.0×10 －３ More preferably, 2.0 × 10 －３ That's it, 2.5 x 10 －３ That's it, 3.0 x 10 －３ That's it, 3.5 x 10 －３ That's it, 4.0 x 10 －３ That's all. It is believed that the greater the internal friction, the less unwanted resonance and reverberation of the diaphragm can be achieved. There is no particular upper limit to the internal friction, but it is typically 9.0 × 10 －３ The following is the result.

[0056] The Young's modulus E of the glass constituting the vibrating section 11 is preferably 60 GPa or more, 65 GPa or more, or 70 GPa or more. The specific elastic modulus can be increased by increasing the Young's modulus E. From the viewpoint of containing a certain amount or more of alkali metal oxide in order to maintain high ion exchange performance, the upper limit of the Young's modulus E is preferably, for example, 80 GPa or less, 77 GPa or less, or 75 GPa or less.

[0057] The density ρ of the glass constituting the vibrating section 11 is preferably 3.0 g / cm ３ Below, 2.9g / cm ３ Below, 2.8g / cm ３ The specific elastic modulus can be increased by decreasing the density ρ.

[0058] The specific elastic modulus E / ρ of the glass constituting the vibrating section 11 is preferably 25 GPa cm ３ / g or more, more preferably 26 GPa cm ３ / g or more, 27GPa・cm ３ / g or more. It is believed that the higher the specific elastic modulus, the better the response of the diaphragm and the better the sound output. There is no particular upper limit to the specific elastic modulus, but it is typically 35 GPa cm ３ / g or less.

[0059] The value obtained by dividing the specific elastic modulus by the internal friction is 5,000 to 20,000 GPa cm ３ / g, and more preferably 6000 to 15000 GPa cm ３ / g, 7000~14000GPa・cm ３ By setting the value obtained by dividing the specific elastic modulus by the internal friction within this range, well-balanced acoustic characteristics can be obtained.

[0060] The softening point Ts of the glass constituting the vibrating section 11 is preferably 950°C or less, 930°C or less, 920°C or less, 910°C or less, or 900°C or less, particularly 770 to 900°C. If the softening point is too high, bending by heat treatment becomes difficult. The "softening point" refers to a value measured based on the method of ASTM C338.

[0061] High-temperature viscosity 10 of the glass constituting the vibration part 11 ２．５ The temperature at viscosity dPa·s is preferably 1660°C or less, less than 1600°C, 1590°C or less, 1580°C or less, 1570°C or less, 1560°C or less, and particularly preferably 1400 to 1550°C. ２．５ If the temperature at 10 dPa·s is too high, the melting property and formability are reduced, making it difficult to form the molten glass into a sheet. ２．５ "Temperature at dPa s" refers to the value measured by the platinum ball pull-up method. ２．５ The lower the temperature at dPa·s, the lower the melting temperature becomes, which reduces the burden on glass manufacturing equipment such as a melting furnace and also makes it easier to improve the bubble quality. ２．５The lower the temperature at viscosity dPa·s, the easier it is to reduce the manufacturing cost of the glass.

[0062] The liquidus temperature TL of the glass constituting the vibration part 11 is preferably 1200°C or less, 1150°C or less, 1100°C or less, 1050°C or less, 1000°C or less, 950°C or less, 900°C or less, particularly 880°C or less. The lower the liquidus temperature, the better the devitrification resistance and formability. ２ O.K. ２ O, B ２ O ３ The content of Al is increased. ２ O ３ , Li ２ O, MgO, ZnO, TiO ２ , ZrO ２ The "liquidus temperature" is defined as the highest temperature at which devitrification (devitrification particles) is observed inside the glass when a glass powder that passes through a standard sieve of 30 mesh (500 μm) and remains on a 50 mesh (300 μm) sieve is placed in a platinum boat and held in a temperature gradient furnace for 24 hours, and then the platinum boat is removed and the glass is observed under a microscope.

[0063] <Tempered Glass Diaphragm> In one embodiment, the vibration section 11 of the glass diaphragm 10 can be made of tempered glass having the glass composition described above, typically chemically tempered glass. With this configuration, it is possible to achieve both excellent sound quality and high strength.

[0064] The vibration part 11 has a compressive stress layer on the surface and a tensile stress layer inside. When the glass vibration plate 10 is made entirely of glass, the glass vibration plate 10 can be made entirely of tempered glass.

[0065] The maximum compressive stress value CS of the compressive stress layer is, for example, 200 MPa or more, preferably 300 MPa or more, 400 MPa or more, 500 MPa or more, 600 MPa or more, particularly 700 MPa or more. The larger the maximum compressive stress value CS, the easier it is to improve the bending strength. On the other hand, if an extremely large compressive stress is formed on the surface, the maximum tensile stress value CT inherent in the tempered glass becomes extremely high, and there is a risk of large dimensional changes before and after the ion exchange treatment. Therefore, the compressive stress value of the outermost surface can be, for example, 1500 MPa or less, preferably 1300 MPa or less, 1200 MPa or less, 1100 MPa or less, or 1000 MPa or less.

[0066] The smaller the stress depth DOL, the greater the internal friction tends to be, and from the viewpoint of obtaining good sound quality, it is preferable to reduce the stress depth DOL. Therefore, the upper limit of the ratio DOL / t of the stress depth DOL to the thickness t is 0.25 or less, preferably 0.20 or less, 0.19 or less, 0.18 or less, 0.17 or less, 0.16 or less, 0.15 or less. In particular, in a vibrating part 11 made of glass with a thickness of 100 μm or less, the upper limit of the stress depth DOL is preferably 20 μm or less, 15 μm or less, 14 μm or less, 13 μm or less, 12 μm or less, 11 μm or less, particularly 10 μm or less. On the other hand, the greater the stress depth DOL, the greater the advantage that the strength of the vibrating part 11 is improved and it becomes less likely to crack. In addition, when trying to increase the maximum compressive stress value CS, it may be difficult to reduce the DOL. Therefore, the lower limit of the ratio DOL / t of the stress depth DOL to the thickness t is preferably 0.001 or more, 0.01 or more, 0.05 or more, or 0.1 or more. The lower limit of the stress depth DOL is, for example, 1 μm or more, preferably 2 μm or more, 3 μm or more, particularly 4 μm or more.

[0067] When prioritizing the improvement of the strength of the vibration part 11, the ratio DOL / t of the stress depth DOL to the thickness t can be, for example, 0.05 or more, preferably 0.10 or more, 0.15 or more, or 0.20 or more. The stress depth DOL can be, for example, 5 μm or more, 10 μm or more, 15 μm or more, particularly 30 μm or more.

[0068] The lower limit of CS / DOL, the value obtained by dividing the maximum compressive stress value CS by the stress depth DOL, is preferably 50 MPa / μm or more, 60 MPa / μm or more, 70 MPa / μm or more, 80 MPa / μm or more, or 90 MPa / μm or more. By making the stress characteristics satisfy such numerical ranges, it is possible to obtain a vibration section 11 with an excellent balance between sound quality and strength. The upper limit of CS / DOL is, for example, 1000 MPa / μm or less.

[0069] The internal maximum tensile stress value CT is preferably 400 MPa or less, 350 MPa or less, 300 MPa or less, 250 MPa or less, 220 MPa or less, 200 MPa or less, 180 MPa or less, particularly 170 PMa or less. If the internal tensile stress value is too high, the tempered glass is prone to self-destruction due to physical collisions, etc. On the other hand, since the maximum tensile stress value CT is a value determined by the balance between CS, DOL and thickness t, if one attempts to reduce the maximum tensile stress value CT, it is necessary to limit CS to a small value. Therefore, the internal tensile stress value is preferably 20 MPa or more, 30 MPa or more, particularly 40 MPa or more. The internal tensile stress can be calculated using the following formula 1. CT = (CS × DOL) / (t - 2 × DOL) ... (1)

[0070] <Non-tempered glass diaphragm> In one embodiment, the vibration section 11 of the glass diaphragm 10 can be made of non-tempered glass. In this case, the vibration section 11 has substantially no stress on the surface or inside. Here, "substantially no stress" means that the internal stress in the glass is 10 MPa or less, both in terms of compressive stress and tensile stress. In other words, stress due to minute distortions generated during glass molding may be present. In certain glass compositions, non-tempered glass (i.e., glass before ion exchange treatment) has greater internal friction than tempered glass (i.e., glass after ion exchange treatment), which may be advantageous in terms of sound quality.

[0071] <Method for Manufacturing Glass Vibration Plate> As shown in FIG. 8, a method for manufacturing the glass vibration plate 10 according to one aspect of the present invention includes a glass preparation step S10, a cutting step S20, and a shaping step S30, in this order.

[0072] The glass preparation step S10 is a step of preparing a glass for a diaphragm. The glass for a diaphragm has a thickness of 5 to 1000 μm and a glass composition of SiO ２ 40-80%, Al ２ O ３ 5-25%, B ２ O ３ 0-30%, Li ２ O 0-25%, Na ２ O 5-25%, K ２ O 0-25%, MgO 0-20%, ZnO 0-15%, P ２ O ５ Contains 0-15%.

[0073] The glass preparation step S10 need only involve obtaining and preparing the above-mentioned glass for a diaphragm, and does not necessarily include a step of directly manufacturing the glass for a diaphragm. However, if the glass preparation step S10 includes a step of manufacturing the glass for a diaphragm, the following exemplary method can be adopted.

[0074] The manufacturing process of the glass for vibration plates includes a melting step of blending and melting glass raw materials blended to have the above-mentioned glass composition, a forming step of forming the mother glass into a flat plate-like or sheet-like mother glass by a predetermined forming method, and, if necessary, a rough cutting step of cutting the formed mother glass into small glass pieces and a thickness adjusting step of adjusting the thickness of the small glass pieces.

[0075] The forming method in the forming step can be selected from, for example, the overflow downdraw method, the slot downdraw method, the float method, and the redraw method. In order to obtain a smooth surface, it is preferable to use the overflow downdraw method. Note that when formed by the overflow downdraw method, the glass for diaphragm has a forming confluence surface inside.

[0076] In the rough cutting step, for example, a scribe line is formed in the mother glass, and bending stress is applied to break and cut the mother glass. Any cutting method may be used as long as it can cut the mother glass into small pieces of any desired size. Furthermore, in cases where glass can be cut directly from the mother glass in the cutting step described below, the rough cutting step may be omitted.

[0077] In the thickness adjustment step, the thickness of the glass is adjusted to be thin by, for example, polishing or etching, or a combination of these. The polishing step can be a double-sided polishing or single-sided polishing method using a known mechanical polishing device. The etching step can be a wet etching method in which the glass is immersed in an acidic or alkaline etching solution. For example, an acidic aqueous solution containing HF can be used as the acidic etching solution. For example, an alkaline aqueous solution containing NaOH or KOH can be used as the alkaline etching solution. Note that if glass of the desired thickness is obtained directly in the molding step, the thickness adjustment step may be omitted.

[0078] The diaphragm glass prepared in the glass preparation step is cut in the cutting step.

[0079] The cutting step S20 is a step of performing a cutting process to cut the small glass pieces into plates with a predetermined contour. The contour shape can be a shape that corresponds to the shape of the glass vibration plate 10 that is finally obtained. The contour shape of the cut glass can be, for example, a circle, an ellipse, a donut, or a rectangle (a square or a rectangle). In the cutting step, for example, a laser beam can be used to perform the cutting process. Specifically, the laser beam can be scanned along a trajectory that follows the contour of the glass, and the glass can be broken by melting or thermal stress. The laser beam can be, for example, a CO ２ A laser, a CO laser, or a YAG laser can be used. In addition to the method using laser light, cutting can also be performed by mechanical processing.

[0080] In the shape processing step S30, the glass sheet obtained in the cutting step is processed into a three-dimensional shape. Specifically, the glass sheet is heated, softened, and deformed along a forming die. More specifically, the heated glass sheet can be press-molded and shaped by being clamped under pressure between a press die. Alternatively, the glass sheet can be placed on the forming die and softened by heating, causing deformation under its own weight, thereby processing the glass sheet into a shape that conforms to the forming die. Note that if the glass diaphragm 10 has a two-dimensional flat shape, this shape processing step may be omitted.

[0081] <Method for manufacturing tempered glass diaphragm> When the vibration part 11 is made of chemically tempered glass, the above-mentioned method for manufacturing a glass diaphragm further includes an ion exchange process. The ion exchange process can be performed on the three-dimensional glass obtained in the shape processing process.

[0082] In the ion exchange step, the glass is immersed in a molten salt to perform an ion exchange treatment on the glass.

[0083] The molten salt is a salt containing a component that can be ion-exchanged with the component in the tempered glass, and is typically an alkali metal nitrate. Examples of alkali metal nitrates include NaNO ３ , KNO ３ , LiNO ３ These can be used alone (100% by mass) or in combination. When mixing multiple types of alkali metal nitrates, the mixing ratio can be determined arbitrarily. For example, NaNO ３ 5-95%, KNO ３ 5 to 95%, preferably NaNO ３ 30-80%, KNO ３ 20 to 70%, more preferably NaNO ３ 50-70%, KNO ３ It can be 30 to 50%.

[0084] The temperature of the molten salt is, for example, 350 ° C to 500 ° C, preferably 355 ° C to 490 ° C, 360 ° C to 480 ° C, 365 ° C to 450 ° C, or 370 ° C to 440 ° C. The immersion time is, for example, 0.01 to 50 hours, preferably 0.03 to 10 hours, 0.05 to 5 hours, or 0.08 to 1 hour. From the viewpoint of reducing the compression depth DOL, the immersion time is preferably 1 hour or less, 0.5 hours or less, 0.2 hours or less, or 0.15 hours or less.

[0085] After the ion exchange treatment, a cleaning step may be further provided in which the glass is immersed in a cleaning solution containing water to clean it.

[0086] Although the embodiment of the present invention has been described, the embodiment of the present invention is not limited to this, and various modifications can be made without departing from the spirit of the present invention.

[0087] <Modifications> In the above embodiment, the shapes of the glass diaphragm 10 and the vibrating portion 11 are merely examples, and other shapes may also be adopted. For example, the glass diaphragm 10 may be in the shape of a bent plate (FIG. 9) or a split tube.

[0088] The vibration part 11 may also have a two-dimensional shape, i.e., a flat plate shape. In this case, the vibration part 11 may be a rectangular plate shape whose main surface has a substantially rectangular (rectangular or square) outline in a plan view. The vibration part 11 may also be a disk shape whose main surface has a circular or elliptical diameter. In these forms, the glass vibration plate 10 can naturally be composed of the vibration part 11 alone. Furthermore, when the glass vibration plate 10 and the vibration part 11 are flat, the shape processing step can be omitted in the manufacturing method of the glass vibration plate.

[0089] In the above embodiment, the case where the ion exchange step is performed after the shaping step is exemplified, but the ion exchange step may be performed on the two-dimensional plate glass obtained in the cutting step.Furthermore, the two-dimensional plate glass that has been subjected to the ion exchange step after the cutting step may be subjected to the shaping step.

[0090] In the above embodiment, the acoustic device 1 is a speaker unit, but the acoustic device of the present invention is not limited to this as long as it is a device that oscillates sound waves using the glass diaphragm 10. For example, the acoustic device of the present invention may be a driver unit for earphones or headphones.

[0091] In the above embodiment, the acoustic device 1 may further include a light source unit 30 that irradiates light toward the glass diaphragm 10 or the vibration unit 11 that constitutes the glass diaphragm 10. The light source unit 30 is typically an LED (Light Emitting Diode) light source. The light source unit 30 can be configured, for example, as a color-adjustable light source capable of emitting colored light. Specifically, the light source unit 30 can emit, for example, red, orange, yellow, yellow-green, green, light blue, blue, purple, pink, white, and intermediate colors among these colors. The acoustic device 1 may further include a controller that controls the light source unit 30. The light source unit 30 can also change the color tone of the emitted light at predetermined time intervals or in accordance with music. The light source unit 30 can also constantly emit light of a constant color tone. The light source unit 30 can also have a dimming function that can adjust the intensity of the emitted light. These configurations allow the color design of the vibration unit 11 in the acoustic device 1 to be easily changed without changing the glass characteristics.

[0092] In addition, if the glass diaphragm 10 or the vibration part 11 that constitutes it is made of colored glass, the color of the colored light emitted from the light source part 30 can be combined with the color of the glass to produce a color different from the color of the colored light and the glass alone. The light source part 30 can also emit complementary color light that is complementary to the color of the glass diaphragm 10 and the vibration part 11. For example, the light source part 30 can emit bluish colored light onto the glass diaphragm 10 and the vibration part 11 made of yellowish glass. Using complementary color light makes it possible to adjust the color saturation and hue of the glass diaphragm 10 and the vibration part 11 to be lower. <Example>

[0093] The glass diaphragm according to the present invention will be described below based on examples. Note that the following examples are merely illustrative, and the present invention is not limited to the following examples. In Tables 1 to 4, Nos. 1 to 26 are examples of the present invention, and No. X1 is a comparative example. Note that No. X1 is an alkali-free glass that does not substantially contain alkali metal oxides as a glass composition.

[0094] Glass samples were prepared as follows: First, flat glass plates having the glass compositions shown in Tables 1 to 4 were prepared.

[0095] Specifically, glass raw materials were prepared to have the compositions shown in Tables 1 to 4 and melted in a test melting furnace. The resulting molten glass was then formed into a sheet having a thickness shown in the tables by an overflow downdraw method, and cut into a disk having a diameter of 30 mm using a laser beam to obtain a glass sample for a diaphragm glass.

[0096] Some of the glass samples were subjected to ion exchange treatment under the conditions shown in the table to produce tempered glass.

[0097]

[0098]

[0099]

[0100]

[0101] The obtained glass samples were measured for the items shown in Tables 1 to 4 as follows.

[0102] The softening point (Ts) is a value measured based on the method of ASTM C338.

[0103] High temperature viscosity 10 ２．５ Temperature at dPa·s (10 ２．５ The viscosity (dPa·s) is a value measured by the platinum sphere pull-up method.

[0104] The liquidus temperature (TL) was determined as the highest temperature at which devitrification (devitrification particles) was observed inside the glass by placing a glass powder that passed through a standard sieve of 30 mesh (500 μm) and remained on a 50 mesh (300 μm) sieve in a platinum boat and holding it in a temperature gradient furnace for 24 hours, and then removing the platinum boat.

[0105] The maximum compressive stress value CS and stress depth DOL were measured using a surface stress meter (FSM-6000 manufactured by Orihara Seisakusho Co., Ltd.). DOL / t, CS / DOL, and maximum tensile stress value CT were calculated based on the measured values.

[0106] The internal stress was calculated based on measurements by the Senarmont method using a polarizing microscope.

[0107] The Young's modulus and internal friction were measured using a JE-RT3 manufactured by Nippon Technoplus Co., Ltd. in accordance with the dynamic elastic modulus measurement method (flexural resonance method) of JIS R1602.

[0108] The density was measured by the Archimedes method.

[0109] The specific modulus was calculated by dividing the Young's modulus by the density.

[0110] The transmittance and chromaticity of each glass sample were measured by separately preparing a sample having a thickness of 1 mm in the same manner as above.

[0111] The transmittance was measured using UV-3100PC (Shimadzu Corporation) with a slit width of 2.0 nm, a scanning speed of medium speed, and a sampling pitch of 0.5 nm, and the spectral transmittance was measured in the wavelength range of 400 nm to 700 nm.

[0112] The chromaticity was measured using the same equipment and under the same conditions as those for the transmittance described above, and the value was calculated based on the C illuminant.

[0113] The color impression was evaluated by sensory evaluation by three observers.

[0114] It was confirmed that the glass of the example had a relatively large internal friction and was excellent in characteristics as a diaphragm compared to the comparative example No. X1.

[0115] The glass article of the present invention can be used as a diaphragm for acoustic devices such as speakers, sound bars, surround systems, wireless speakers, earphones, headphones, etc. Furthermore, the acoustic devices can be connected to or integrally mounted on devices such as display devices, smartphones, tablet computers, personal computers, vehicles, etc.

[0116] REFERENCE SIGNS LIST 1 Acoustic device 10, 10a, 10b, 10c, 10d Glass diaphragm 11 Vibration section 12 Connection section 13 Edge section 14 Center dome 20 Drive section 30 Light source section

Claims

1. A vibrating part having a thickness t of 5 to 2000 μm, wherein the vibrating part has a glass composition of, in mol %, SiO ２ 40-80%, Al ２ O ３ 5-25%, B ２ O ３ 0-30%, Li ２ O 0-25%, Na ２ O 5-25%, K ２ O 0-25%, MgO 0-20%, ZnO 0-15%, P ２ O ５ A glass diaphragm characterized by being made of glass containing 0 to 15% of cellulose.

2. The glass diaphragm according to claim 1, wherein the vibrating portion has a three-dimensional shape selected from the group consisting of a cone, a trumpet, a dome, and a curved plate.

3. The internal friction of the glass constituting the vibrating part is 1.0 x 10 －３ The glass diaphragm according to claim 1 or 2.

4. The specific elastic modulus of the glass constituting the vibrating part is 25 GPa cm ３ The glass diaphragm according to claim 3, wherein the modulus of elasticity is 1 / g or more.

5. A glass diaphragm according to claim 1 or 2, wherein the glass constituting the vibrating part comprises a compressive stress layer having compressive stress on its surface, and a tensile stress layer having tensile stress inside the compressive stress layer, the maximum compressive stress value CS of the outermost surface of the compressive stress layer is 50 to 1500 MPa, and the ratio DOL / t of the stress depth DOL to the thickness t of the compressive stress layer is 0.001 to 0.

25.

6. The glass diaphragm according to claim 5, wherein the thickness t of the vibrating portion is 5 to 70 μm, the depth DOL of the compressive stress layer is 15 μm or less, the maximum compressive stress value CS is 600 to 1300 MPa, and CS / DOL≧40 MPa / μm is satisfied.

7. A glass diaphragm according to claim 1 or 2, wherein the average transmittance at wavelengths of 400 nm to 700 nm, calculated per 1 mm of plate thickness of the diaphragm, is 85% or more.

8. The vibrating part has a glass composition of Fe ２ O ３ , TiO ２ , CeO ２ , W.O. ３ , NiO, Cr ２ O ３ , CuO, and Co ３ O ４ 3. The glass diaphragm according to claim 1, wherein the glass diaphragm contains at least one of the above in an amount of 10 ppm or more by mole %.

9. A glass diaphragm according to claim 1 or 2, wherein the internal stress of the glass constituting the vibrating portion is less than 10 MPa.

10. The glass diaphragm according to claim 1, wherein the vibrating portion has a flat plate shape.

11. An acoustic device comprising: a glass diaphragm according to claim 1 or 2; and a drive unit that vibrates the vibration part of the glass diaphragm to generate sound waves.

12. The acoustic device according to claim 11, wherein the glass diaphragm is made of colored glass, and further comprising a light source unit that irradiates the glass diaphragm with colored light.

13. A flat plate having a thickness of 5 to 1000 μm, and a glass composition of SiO ２ 40-80%, Al ２ O ３ 5-25%, B ２ O ３ 0-30%, Li ２ O 0-25%, Na ２ O 5-25%, K ２ O 0-25%, MgO 0-20%, ZnO 0-15%, P ２ O ５ A method for manufacturing a glass diaphragm, comprising: a step of preparing glass for a diaphragm containing 0 to 15% of cellulose acetate; a step of cutting the glass for a diaphragm into glass plates having a predetermined contour; and a step of processing the cut glass plates into a three-dimensional shape.

14. The method for manufacturing a glass vibration plate according to claim 13, further comprising a step of subjecting the three-dimensionally shaped glass that has been subjected to ion exchange treatment.

15. A method for manufacturing a glass vibration plate according to claim 13 or 14, wherein the cutting process is performed by scanning a laser beam along the predetermined contour, and the shaping process is performed by heating and press-molding the plate glass.

16. The plate thickness is 5 to 200 μm, and the glass composition is, in mol%, SiO ２ 40-80%, Al ２ O ３ 5-25%, B ２ O ３ 0-30%, Li ２ O 0-25%, Na ２ O 5-25%, K ２ O 0-25%, MgO 0-20%, ZnO 0-15%, P ２ O ５ A glass for a vibration plate, characterized by containing 0 to 15%.

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