Spacer and multilayer glass

Abstract

A spacer according to the present disclosure is interposed between a first glass substrate and a second glass substrate opposing each other, and is disposed in contact with the first glass substrate and the second glass substrate. The spacer according to the present disclosure is provided with: a first contact surface disposed in contact with the first glass substrate; a second contact surface disposed in contact with the second glass substrate; and a lateral surface located between the first contact surface and the second contact surface. The mean value RΔq1 of root mean square slopes in a roughness curve of the first contact surface is more than the mean value RΔq2 of root mean square slopes in a roughness curve of the lateral surface.

Description

Technical Field

[0001] The present disclosure relates to a spacer and a multilayer glass used for a multilayer glass in which a pair of glass substrates are laminated through a depressurized internal space.

Background Art

[0002] Conventionally, a multilayer glass is known in which a pair of glass substrates are arranged facing each other, an internal space is created by sealing the outer peripheral portions of the pair of glass substrates with a sealing material, and the air inside the space is evacuated to reduce the pressure. For example, Patent Document 1 discloses a plurality of spacers interposed in an internal space in order to hold the internal space located between a pair of glass substrates in a multilayer glass.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Means for Solving the Problems

[0004] The spacer of the present disclosure is interposed between a first glass substrate and a second glass substrate facing each other and is arranged in contact with the first glass substrate and the second glass substrate. The spacer of the present disclosure includes a first contact surface arranged in contact with the first glass substrate, a second contact surface arranged in contact with the second glass substrate, and a side surface located between the first contact surface and the second contact surface. The average value RΔq1 of the root mean square slope in the roughness curve of the first contact surface is larger than the average value RΔq2 of the root mean square slope in the roughness curve of the side surface.

Brief Description of the Drawings

[0005]

Figure 1

Figure 2A

Figure 2B

Figure 3A

Figure 3B

Figure 4A

Figure 4B

Figure 5A

Figure 5B

DETAILED DESCRIPTION OF THE INVENTION

[0006] The thermal conductivity of the spacer 3 is greater than the thermal conductivity of the internal space 4. Therefore, heat is conducted between the first glass substrate 1 and the second glass substrate 2 facing each other (hereinafter, these may be referred to as a pair of glass substrates 1 and 2) via the spacer 3. As a result, the heat insulation property of the multilayer glass 100 is likely to deteriorate. Further, when the side surface 300 of the spacer 3 comes into contact with either of the pair of glass substrates 1 and 2 when the spacer 3 is attached to the pair of glass substrates 1 and 2, exfoliation is likely to occur on the side surface 300 of the spacer 3. As a result, the exfoliated particles float in the internal space 4, and the light transmittance of the multilayer glass 100 is likely to decrease.

[0007] In the spacer 3 of the present disclosure, the average value RΔq1 of the root mean square slope in the roughness curve of the first contact surface 301 is greater than the average value RΔq2 of the root mean square slope in the roughness curve of the side surface 300. Thereby, the contact area between the spacer 3 and the first glass substrate 1 can be reduced, and the heat insulation property of the multilayer glass 100 can be improved. Further, exfoliation from the side surface 300 can be reduced, and the light transmittance of the multilayer glass 100 can be improved.

[0008] Hereinafter, with reference to the drawings, a spacer 3 for a multilayer glass and a multilayer glass 100 according to an embodiment of the present disclosure will be described. FIG. 1 is a schematic cross-sectional view of the multilayer glass 100, and FIGS. 2A and 2B are schematic plan views showing a state where a plurality of spacers 3 are mounted on the surface of the first glass substrate 1.

[0009] As shown in FIG. 1, the multilayer glass 100 according to the present embodiment includes a first glass substrate 1, a second glass substrate 2 disposed opposite to the first glass substrate 1, a spacer 3 interposed between the first glass substrate 1 and the second glass substrate 2, an internal space 4 located between the first glass substrate 1 and the second glass substrate 2, a peripheral edge portion 5 of the first glass substrate 1, a seal portion 6 for sealing the peripheral edge portion 5, and an exhaust pipe 7 for exhausting the internal space 4.

[0010] The first glass substrate 1 and the second glass substrate 2 are, for example, rectangular and flat glass plates. Examples of the first glass substrate 1 and the second glass substrate 2 include float glass such as tempered glass. The thickness of the first glass substrate 1 and the second glass substrate 2 is, for example, 1 mm or more and 5 mm or less. The second glass substrate 2 has the same dimensions as the first glass substrate 1 as shown in FIG. 2B.

[0011] The spacer 3 is interposed in the internal space 4 located between the pair of glass substrates 1 and 2 facing each other and is disposed in contact with the pair of glass substrates 1 and 2. Thereby, the internal space 4 is held. A plurality of spacers 3 are disposed between the first glass substrate 1 and the second glass substrate 2 at a predetermined interval, for example. The arrangement interval of the spacers 3 is, for example, a pitch of 1 to 3 cm.

[0012] As shown in FIG. 2A, for example, the spacer 3 is placed on the surface of the first glass substrate 1 at a predetermined interval. At this time, the surface of the first glass substrate 1 is held horizontally. Therefore, when the spacer 3 is placed at a predetermined position on the surface of the first glass substrate 1, the inadvertent movement of the spacer 3 is reduced.

[0013] The internal space 4 is a space surrounded by the first glass substrate 1, the second glass substrate 2, and the seal portion 6. The internal space 4 is evacuated from the exhaust pipe 7 to be in a vacuum state or a reduced-pressure state. Thereby, heat exchange between the first glass substrate 1 and the second glass substrate 2 is reduced, and the heat insulation property of the double-layer glass 100 can be enhanced. The reduced-pressure state is, for example, 10 -5 Pa or more and 10 -1 Pa or less.

[0014] The seal portion 6 is located at the peripheral edge portion 5 of the first glass substrate 1. The seal portion 6 is, for example, located on the entire circumference of the peripheral edge portion 5 of the first glass substrate 1 and surrounds the internal space 4. The height of the seal portion 6 is, for example, the same as the height of the spacer 3. The seal portion 6 is made of, for example, low-melting glass frit. Examples of the low-melting glass frit that can be used as a sealing material include bismuth-based seals, frit pastes, etc. containing 70% by mass or more of Bi 2 O 3 each, 15% by mass or less of B 2 O 3 and ZnO respectively, and further containing 5% by mass or more of a mixture of organic substances such as ethyl cellulose and terpineol.

[0015] The seal portion 6 can be formed, for example, by the following method. After applying a sealing material to the peripheral edge portion 5 of the first glass substrate 1 using a dispenser, it is dried. Next, the second glass substrate 2 is disposed opposite on the first glass substrate 1, and in this state, the pair of glass substrates 1 and 2 are placed in a furnace and heated to melt the low-melting glass frit to seal the periphery of the pair of glass substrates 1 and 2 to form the seal portion 6. The seal portion 6 is formed, for example, by applying, heating, and melting glass frit.

[0016] The exhaust pipe 7 evacuates the internal space 4 to make the internal space 4 in a vacuum or reduced-pressure state. The exhaust pipe 7 penetrates the second glass substrate 2 in the thickness direction, for example.

[0017] As shown in FIGS. 3A and 3B, the spacer 3 of this embodiment includes a first contact surface 301 disposed in contact with the first glass substrate 1, a second contact surface 302 disposed in contact with the second glass substrate 2, and a side surface 300 located between the first contact surface 301 and the second contact surface 302. The side surface 300 shown in FIGS. 3A and 3B is directly connected to the first contact surface 301 and the second contact surface 302.

[0018] The average value RΔq1 of the root mean square slope in the roughness curve of the first contact surface 301 is larger than the average value RΔq2 of the root mean square slope in the roughness curve of the side surface 300. As a result, when the average value RΔq1 of the root mean square slope in the roughness curve of the first contact surface 301 is large, the slope of the unevenness of the first contact surface 301 becomes large. Therefore, the contact area with the first glass substrate 1 becomes small, and the heat insulation property of the multilayer glass 100 can be improved.

[0019] The average value RΔq2 of the root mean square slope in the roughness curve of the side surface 300 is small. Therefore, the unevenness of the surface properties of the side surface 300 becomes gentle. As a result, even if the side surface 300 touches the first glass substrate 1 or the second glass substrate 2 when the spacer 3 is attached into the multilayer glass 100, the exfoliation from the side surface 300 can be reduced. Therefore, the particles floating in the internal space 4 of the multilayer glass 100 are reduced, and the light transmittance of the multilayer glass 100 can be improved.

[0020] The average value RΔq2 of the root mean square slope in the roughness curve of the side surface 300 is small. Therefore, it is difficult for the spacer 3 to exchange heat with the internal space 4 through the side surface 300. As a result, the temperature of the internal space 4 can be stabilized. Similar to the first contact surface 301, the average value RΔq3 of the root mean square slope in the roughness curve of the second contact surface 302 may be larger than the average value RΔq2 of the root mean square slope in the roughness curve of the side surface 300. As a result, the same effect as that of the first end portion 3211 can be obtained.

[0021] The average values RΔq1 and RΔq3 of the root mean square slope are, for example, 0.3 or more and 0.7 or less. The average value RΔq2 of the root mean square slope is, for example, 0.01 or more and 0.29 or less. The difference between the average values RΔq1 and RΔq3 of the root mean square slope and the average value RΔq2 of the root mean square slope is, for example, 0.05 or more and 0.65 or less.

[0022] The root mean square slope in the roughness curves of the side surface 300, the first contact surface 301, and the second contact surface 302 complies with JIS B0601:2001 and can be measured using a laser microscope (manufactured by Keyence Corporation, ultra-depth color 3D shape measurement microscope (VK-X1000 or its successor model)). As the measurement conditions, the illumination method is coaxial epi-illumination, the measurement magnification is 480 times, the cut-off value λs is none, the cut-off value λc is 0.08 mm, the cut-off value λf is none, correction for end effect is provided, and the measurement range for each surface may be 710 μm × 533 μm. Then, four lines to be measured are drawn at substantially equal intervals in each measurement range, line roughness measurement is performed, and the average value of the root mean square slope may be calculated. When the side surface 300 is the measurement object, the length per line is, for example, 240 μm. When the first contact surface 301 and the second contact surface 302 are the measurement objects, the length per line is, for example, 300 μm.

[0023] In the spacer 3 of the present embodiment, the average value Rsk1 of kurtosis in the roughness curve of the first contact surface 301 is larger than the average value Rsk2 of kurtosis in the roughness curve of the side surface 300. As a result, the average value Rsk1 of kurtosis in the roughness curve of the first contact surface 301 is large. Therefore, the sharpness of the protrusions on the first contact surface 301 increases. As a result, the contact area with the first glass substrate 1 decreases, and the contact thermal resistance with the first glass substrate 1 increases. Therefore, the heat insulation property of the multilayer glass 100 can be further improved.

[0024] The average value Rsk2 of kurtosis in the roughness curve of the side surface 300 is small. Therefore, the sharpness of the protrusions on the side surface 300 is reduced. As a result, even if the side surface 300 touches the first glass substrate 1 or the second glass substrate 2 when the spacer 3 is attached into the multi-layer glass 100, the exfoliation from the side surface 300 can be reduced. Therefore, the particles floating in the internal space 4 of the multi-layer glass 100 can be further reduced, and the light transmittance of the multi-layer glass 100 can be further improved.

[0025] The average value Rsk2 of kurtosis in the roughness curve of the side surface 300 is small. Therefore, heat exchange with the internal space 4 through the side surface 300 becomes difficult, and the temperature of the internal space 4 is stabilized. Similar to the first contact surface 301, the average value Rsk3 of kurtosis in the roughness curve of the second contact surface 302 may be larger than the average value Rsk2 of kurtosis in the roughness curve of the side surface 300.

[0026] The average values Rsk1 and Rsk3 of kurtosis are, for example, 1.7 or more and 5.6 or less. The average value Rsk2 of kurtosis is, for example, 0.6 or more and 3.1 or less. The difference between the average values Rsk1 and Rsk3 of kurtosis and the average value Rsk2 of kurtosis is, for example, 1.5 or more and 4.5 or less. The kurtosis in the roughness curves of the side surface 300, the first contact surface 301, and the second contact surface 302 may be obtained by the same measurement method as the measurement method of the root mean square slope described above.

[0027] In the spacer 3 of the present embodiment, the side surface 300 is a fired surface. The fired surface is a surface in the state as fired without performing processes such as grinding and polishing after firing the ceramics. Thereby, the generation of the crushed layer is suppressed, and the exfoliation from the side surface 300 can be reduced. As a result, the particles floating in the internal space 4 of the multi-layer glass 100 are further reduced, and the light transmittance of the multi-layer glass 100 can be further improved.

[0028] The fact that the side surface 300 is a fired surface can be confirmed by observing the side surface 300 using an ultra-depth color 3D shape measurement microscope (VK-X1000 or its successor model) with a magnification of 480 times.

[0029] The spacer 3 of the present embodiment is, for example, in a disk-shaped or flat-plate-shaped form, or in a columnar shape such as a cylindrical shape or a polygonal columnar shape. FIGS. 3A and 3B show an example where the spacer 3 is disk-shaped. As shown in FIGS. 4A to 5B, the spacer 3 may further include a plate-shaped or columnar central portion 31, a first end portion 3211 protruding from the central portion 31, and a second end portion 3212 located on the opposite side of the first end portion 3211 and protruding from the central portion 31. The side surface 300 is located at the outer edge of the central portion 31, the first contact surface 322 is located on the side of the first glass substrate 1 of the first end portion 3211, and the second contact surface 323 is located on the side of the second glass substrate 2 of the second end portion 3212.

[0030] The central portion 31 is, for example, in a plate shape such as a disk shape or a flat plate shape, or in a columnar shape such as a cylindrical shape or a polygonal columnar shape. The first end portion 3211 and the second end portion 3212 are, for example, in a plate shape such as a disk shape or a flat plate shape. The first end portion 3211 and the second end portion 3212 are, for example, in a tapered shape such as a spherical crown shape, a spherical belt shape, a frustum of a cone shape, or a frustum of a polygonal pyramid shape.

[0031] FIGS. 4A and 4B show an example where the central portion 31, the first end portion 3211, and the second end portion 3212 are flat plate-shaped. FIGS. 5A and 5B show an example where the central portion 31 is disk-shaped and the first end portion 3211 and the second end portion 3212 are spherical crown-shaped.

[0032] When the central portion 31 is plate-shaped or polygonal columnar and the first end portion 3211 and the second end portion 3212 are plate-shaped, the width perpendicular to the height direction of the first end portion 3211 may be smaller than the width perpendicular to the height direction of the central portion 31, as shown in FIGS. 4A and 4B. As a result, the contact area between the first end portion 3211 and the first glass substrate 1 becomes smaller, and the heat insulation property of the multilayer glass 100 can be improved. Since the width of the central portion 31 is large, the mechanical strength of the spacer 3 can be increased and the reliability of the spacer 3 can be enhanced. Similarly to the first end portion 3211, the width perpendicular to the height direction of the second end portion 3212 may be smaller than the width perpendicular to the height direction of the central portion 31. Here, the width perpendicular to the height direction is the length obtained by projecting a cross-section including the axis in the height direction.

[0033] Among the widths perpendicular to the height direction of the first end portion 3211 and the second end portion 3212, the width at the position in contact with the central portion 31 is, for example, 0.34 mm or more and 0.54 mm or less. The width perpendicular to the height direction of the central portion 31 is, for example, 0.37 mm or more and 0.64 mm or less. However, the width perpendicular to the height direction of the central portion 31 is larger than the width at the position in contact with the central portion 31 among the widths perpendicular to the height direction of the first end portion 3211 and the second end portion 3212. The difference between the width perpendicular to the height direction of the central portion 31 and the width at the position in contact with the central portion 31 of the first end portion 3211 and the second end portion 3212 is, for example, 30 μm or more and 100 μm or less.

[0034] When the central portion 31 is disk-shaped or columnar and the first end portion 3211 and the second end portion 3212 are spherical cap-shaped, spherical belt-shaped or frustum of a cone-shaped, the diameter perpendicular to the height direction of the first end portion 3211 may become smaller from the central portion 31 side toward the opposite side, as shown in FIG. 5B. As a result, while reducing the contact area between the first end portion 3211 and the first glass substrate 1, the mechanical strength of the first end portion 3211 can be increased. Similarly to the first end portion 3211, the diameter perpendicular to the height direction of the second end portion 3212 may become smaller from the central portion 31 side toward the opposite side.

[0035] Of the diameters perpendicular to the height direction of the first end portion 3211 and the second end portion 3212, the diameter at the position in contact with the central portion 31 is, for example, not less than 0.34 mm and not more than 0.54 mm. The diameter perpendicular to the height direction of the central portion 31 is, for example, not less than 0.37 mm and not more than 0.64 mm. However, the diameter perpendicular to the height direction of the central portion 31 is larger than the diameter at the position in contact with the central portion 31 among the diameters perpendicular to the height direction of the first end portion 3211 and the second end portion 3212. The difference between the diameter perpendicular to the height direction of the central portion 31 and the diameter at the position in contact with the central portion 31 of the first end portion 3211 and the second end portion 3212 is, for example, not less than 30 μm and not more than 100 μm.

[0036] As shown in FIGS. 5A and 5B, the first end portion 3211 may be spherical-crowned. In this case, the first contact surface 322 is curved, and a part of it will contact the first glass substrate 1. Therefore, the contact area between the first end portion 3211 and the first glass substrate 1 can be reduced. Similarly to the first end portion 3211, the second end portion 3212 may be spherical-crowned.

[0037] When the first end portion 3211 is spherical-crowned, the radius of the sphere of the first contact surface 322 is preferably not less than 0.8 mm and not more than 1.6 mm. When the radius is within this range, both the rigidity and heat insulation of the first end portion 3211 can be increased. Even if the second end portion 3212 is spherical-crowned, the radius of the second contact surface 323 is preferably within the above range.

[0038] The respective radii of the first contact surface 322 and the second contact surface 323 can be measured using a laser microscope (manufactured by Keyence Corporation, ultra-depth color 3D shape measurement microscope (VK-X1100 or its successor model)). The measurement conditions are the same as the measurement conditions for obtaining the root mean square slope of the first contact surface 322 and the second contact surface 323, and profile measurement may be performed for each measurement range.

[0039] As shown in FIGS. 4B and 5B, the height (h1) of the central portion 31 may be greater than the sum of the height (h2) of the first end portion 3211 and the height (h3) of the second end portion 3212. Thereby, the mechanical strength of the spacer 3 can be increased. Even if the height (h1) of the central portion 31 is increased, the average value RΔq2 of the root mean square slope in the roughness curve of the side surface 300 is small. Therefore, threshing from the side surface 300 can be reduced. By making the sum of the height (h2) of the first end portion 3211 and the height (h3) of the second end portion 3212 small, the deflection of the spacer 3 can be suppressed.

[0040] The height (h1) of the central portion 31 is, for example, 0.14 mm or more and 0.18 mm or less. The sum of the height (h2) of the first end portion 3211 and the height (h3) of the second end portion 3212 is, for example, 0.02 mm or more and 0.06 mm or less. The height (h2) of the first end portion 3211 and the height (h3) of the second end portion 3212 may be the same.

[0041] In the spacer 3 of the present embodiment, the area occupancy ratio of the pores in the first end portion 3211 is larger than the area occupancy ratio of the pores at the outer edge of the central portion 31. As a result, the contact area between the first glass substrate 1 and the spacer 3 is reduced, and the heat insulation property of the multilayer glass 100 is improved.

[0042] Since the area occupancy ratio of the pores at the outer edge of the central portion 31 is small, the side surface 300 located at the outer edge of the central portion 31 becomes dense. As a result, the mechanical strength of the side surface 300 can be maintained, and the mechanical strength of the spacer 3 can also be maintained. Since the mechanical strength of the side surface 300 is high, even if the side surface 300 touches the first glass substrate 1 or the second glass substrate 2 when the spacer 3 is attached into the multilayer glass 100, the possibility of threshing occurring from the side surface 300 is further reduced. As a result, the particles floating in the internal space 4 of the multilayer glass 100 can be further reduced, and the light transmittance of the multilayer glass 100 can be further improved. Here, the outer edge in the central portion 31 refers to a region up to 20 μm in the width direction from the side surface 300.

[0043] In particular, the difference between the area occupancy rate of pores at the first end portion 3211 and the area occupancy rate of pores at the outer edge of the central portion 31 is preferably 0.2% or more. In order to suppress threshing generated from the first contact surface 322 and particles floating from within the pores, the first end portion 3211 is preferably dense, and the area occupancy rate of pores at the first end portion 3211 is preferably 2% or less, particularly preferably 1% or less.

[0044] To measure the area occupancy rate of pores, in the height direction from the first contact surface 322 toward the central portion 31, and in the diameter (width) direction from the side surface 300 toward the inside of the central portion 31, for example, with a diamond abrasive grain having an average particle diameter D 50 of 0.5 μm, polish with a tin disk. Photograph the polished surface obtained by this polishing using a scanning electron microscope (SEM) at a magnification of 10,000 times, with the measurement target range being, for example, a horizontal length of 12 μm and a vertical length of 9 μm. Next, set the measurement range from the photographed image and analyze it using image analysis software (for example, Win ROOF manufactured by Mitani Corporation) to obtain the pore area ratio. When analyzing, the threshold value for the equivalent circle diameter of the pores is 0.21 μm, and circles with an equivalent circle diameter of less than 0.21 μm are not included in the calculation of the area occupancy rate.

[0045] The spacer 3 of the present embodiment is formed of, for example, ceramics mainly composed of zirconium oxide, mullite, forsterite, cordierite, steatite, alkali metal aluminosilicate, aluminum titanate, or zinc oxide. By forming the spacer 3 of ceramics, the generation of outgas from the spacer 3 can be reduced. Furthermore, a high heat insulation effect can be maintained over a long period. The mechanical strength of the spacer 3 can be improved. The alkali metal aluminosilicate is, for example, β-spodumene. When the ceramics is mainly composed of zirconium oxide, the ceramics preferably has translucency. The translucent ceramics is, for example, ceramics mainly composed of zirconium oxide in which a stabilizer such as calcium oxide, magnesium oxide, yttrium oxide, scandium oxide, or cerium oxide and lanthanum are solid-soluted.

[0046] When the ceramic has zinc oxide as the main component, it may contain 1.9% by mass or more and 3.8% by mass or less in terms of the oxide of Al out of 100% by mass of the components constituting the ceramic. By containing Al within this range, the sintering temperature can be lowered and the thermal conductivity can be reduced. When the ceramic has eucryptite as the main component, it may contain 20% by mass or less of Ti or Zr in terms of the oxide out of 100% by mass of the components constituting the ceramic. By containing Ti or Zr within this range, the thermal conductivity can be reduced and the rigidity can be increased.

[0047] The spacer 3 may be made of a ceramic formed of a composite compound of aluminum oxide and zirconium oxide (hereinafter, the ceramic formed of this composite compound may be referred to as "composite ceramic"). This composite ceramic has, for example, an aluminum oxide content of 20% by mass or more and 80% by mass or less, and a zirconium oxide content of 80% by mass or more and 20% by mass or less. The composite ceramic may contain Si, Ti, and Mg in the form of oxides respectively, and the total content thereof is 0.6% by mass or more and 4.5% by mass or less in terms of the oxide. The composite ceramic can adjust the thermal conductivity and the static elastic modulus indicating the rigidity by adjusting the respective contents of aluminum oxide and zirconium oxide.

[0048] The main component in the ceramic means a component that occupies 80% by mass or more out of 100% by mass of the components constituting the ceramic. The components constituting the ceramic can be identified using an X-ray diffractometer (XRD), and the content thereof can be determined by the Rietveld method. It may also be determined by converting the metal elements obtained by a fluorescent X-ray analyzer (XRF) or an ICP (Inductively Coupled Plasma) emission spectroscopic analyzer into the identified components.

[0049] The first end portion 3211 may be formed of the same ceramics as the central portion 31 or ceramics having a different main component.

[0050] Next, an example of a method for manufacturing the spacer 3 made of the above-described ceramics will be described. For example, when the spacer 3 is formed of ceramics having zirconium oxide as a main component, first, zirconium oxide powder as a main component, yttrium oxide powder as a stabilizer, a dispersant for dispersing zirconium oxide powder as needed, and a binder such as polyvinyl alcohol are wet-mixed for 40 to 50 hours by a barrel mill, a rotary mill, a vibration mill, a bead mill, a sand mill, an agitator mill, etc. to obtain a slurry.

[0051] Here, the average particle diameter (D 50 ) of the zirconium oxide powder is 0.1 μm or more and 2.2 μm or less, and the content of the yttrium oxide powder in 100% by mass of the total of the above powders is 3.6% by mass or more and 8.8% by mass or less. Next, an organic binder such as paraffin wax, PVA (polyvinyl alcohol), and PEG (polyethylene glycol) is weighed in a predetermined amount and added to the slurry. A thickening stabilizer, a dispersant, a pH adjuster, an antifoaming agent, etc. may be added. As the stabilizer, instead of yttrium oxide (Y 2 O 3 ), at least one kind of powder such as cerium oxide (CeO 2 ), dysprosium oxide (Dy 2 O 3 ), magnesium oxide (MgO), and calcium oxide (CaO) may be used.

[0052] When the spacer 3 is made of ceramics having cordierite as a main component, first, synthetic cordierite (2MgO·2Al 2 O 3 ·5SiO 2 ) powder having an average particle diameter of 0.5 μm or more and 5 μm or less, and magnesium aluminate (MgAl 2 O 4)Prepare a powder and an oxide powder of Y, Yb, Er, or Ce with an average particle size of 0.5 μm or more and 2 μm or less. The synthetic cordierite powder and the magnesium aluminate powder constitute the main components in the present disclosure, and the oxide powder of any one of Y, Yb, Er, and Ce constitutes the sub-component. The synthetic cordierite powder is a powder pre-synthesized in the range of 11.77% by mass or more and 13.3% by mass or less of Mg in terms of oxide, 29.1% by mass or more and 33.8% by mass or less of Al in terms of oxide, and 52.0% by mass or more and 53.6% by mass or less of Si in terms of oxide, excluding the addition amount of the magnesium aluminate powder from 100% by mass of the main component.

[0053] Then, weigh a predetermined amount of the synthetic cordierite powder and the magnesium aluminate powder, for example, 93.5% by mass or more and 99.9% by mass or less of the synthetic cordierite powder and 0.01% by mass or more and 6.5% by mass or less of the magnesium aluminate powder. Next, weigh the sub-component in the range of 4.5% by mass or more and 15.0% by mass or less with respect to the total 100% by mass of the synthetic cordierite powder and the magnesium aluminate powder, and wet-mix using a ball mill for 5 hours or more and 30 hours or less until the average particle size becomes 2 μm or less to obtain a slurry. The addition of an organic binder or the like may be carried out as described above.

[0054] Next, spray-dry the slurry containing zirconium oxide powder or synthetic cordierite powder to obtain granules. Then, fill these granules into a molding die and mold them. The molding process can use pressure molding, injection molding, or the like. The molding pressure in pressure molding is, for example, 78 MPa or more and 128 MPa or less.

[0055] Next, a ceramic sintered body is obtained by firing the molded body. The firing is performed, for example, in an air atmosphere. When obtaining a ceramic mainly composed of zirconium oxide, the firing temperature is set to 1400 °C or higher and 1500 °C or lower. When obtaining a ceramic mainly composed of cordierite, the firing temperature is set to 1340 °C or higher and 1440 °C or lower. In either case, the holding time may be 1 hour or longer and 4 hours or shorter. The ceramic sintered body obtained by firing can be used as the spacer 3 as it is. If necessary, at least one of grinding and polishing may be performed on the ceramic sintered body to form the first contact surface and the second contact surface. Thereby, a spacer 3 with high dimensional accuracy can be obtained.

[0056] Here, in the present embodiment, in the molding step, by appropriately adjusting the surface properties of the mold used for pressure molding or injection molding, surface properties such as the root mean square slope or kurtosis of the spacer 3 can be made as desired. Specifically, the mold includes a die having a molding space for filling granules, an upper punch for pressing the granules filled in the molding space from above the molding space, and a lower punch for pressing the granules from below the molding space. To make the average value RΔq1 of the root mean square slope of the first contact surface larger than the average value RΔq2 of the root mean square slope of the side surface, the average value of the root mean square slope of the first pressure surface of the upper punch forming the first contact surface may be made larger than the average value of the root mean square slope of the inner surface of the die. To make the average value RΔq1 0.7 or less, the average value of the root mean square slope of the first pressure surface of the upper punch may be set to, for example, 0.88 or less.

[0057] To make the average value Rsk1 of the kurtosis of the first contact surface larger than the average value Rsk2 of the kurtosis of the side surface, the average value of the kurtosis of the first pressure surface of the upper punch may be made larger than the average value of the kurtosis of the inner surface of the die. To obtain a spacer in which the difference between the average value RΔq1 and the average value RΔq2 is 0.05 or more, a mold in which the difference between the average value of the root mean square slope of the first pressure surface of the upper punch and the average value of the root mean square slope of the inner surface of the die is, for example, 0.063 or more may be used in consideration of shrinkage.

[0058] As a result, the average value RΔq1 of the root mean square average slope in the roughness curve of the first contact surface 322 can be made larger than the average value RΔq2 of the root mean square average slope in the roughness curve of the side surface 300. The average value Rsk1 of kurtosis in the roughness curve of the first contact surface 301 can be made larger than the average value Rsk2 of kurtosis in the roughness curve of the side surface 300.

[0059] Regarding the relationship between the second contact surface and the side surface, by the same concept as the method described above, the average value of the root mean square slope and the average value of kurtosis of each of the inner surface of the die and the first pressing surface of the lower punch may be adjusted. Both the upper punch and the lower punch are provided with a planar second pressing surface connected to the first pressing surface on the outer peripheral side of the first pressing surface. The second pressing surface forms the upper and lower surfaces of the outer edge of the central portion.

[0060] In the molding process of the present embodiment, by making the mold used for compression molding or injection molding into a desired shape, the spacer 3 having a desired shape can be obtained. In the case of compression molding, the molding pressure is, for example, 98 MPa or more and 294 MPa or more. To make the area occupancy ratio of pores at the first end larger than the area occupancy ratio of pores at the outer edge of the central portion, the molding pressure may be, for example, 147 MPa or more and 294 MPa or more.

[0061] In the present embodiment, by not performing processing such as grinding and polishing on the side surface 300 of the ceramic sintered body obtained by firing, the side surface 300 of the spacer 3 can be used as the fired surface.

[0062] Another example of the manufacturing method of the spacer 3 made of the ceramics described above will be described. For example, the first end portion 3211, the second end portion 3212, and the central portion 31 are manufactured separately. Next, the obtained first end portion 3211 and second end portion 3212 are joined to the end surface of the central portion 31 by adhesion or the like. In this way, the first end portion 3211, the second end portion 3212, and the central portion 31 can be made of different materials.

[0063] Next, a method for manufacturing the multilayer glass 100 will be described. First, the first glass substrate 1 is held so that its surface is horizontal. Next, as shown in FIG. 2A, a plurality of spacers 3 are arranged on the surface of the first glass substrate 1 at a predetermined interval. For this purpose, for example, the spacer 3 is held by a suction means (not shown) having an air suction port, and the spacer 3 is transported to a predetermined position on the surface of the first glass substrate 1. Next, the suction means is lowered at this position and placed on the surface of the first glass substrate 1, and in this state, the air suction is stopped and the suction means is raised. The operation of changing back to the original position in preparation for the next suction may be repeated. The suction and conveyance of the spacer 3 may be performed for each row, or a plurality of examples may be performed at once.

[0064] As another method, for example, a plate (not shown) provided with a plurality of through holes having a size through which only one spacer 3 can pass is placed on the surface of the first glass substrate 1. Next, a large number of spacers 3 are scattered on the plate, and it is confirmed that the spacers 3 are fitted into all the through holes. Thereafter, by removing the plate together with the excess spacers 3, the plurality of spacers 3 can be arranged on the surface of the first glass substrate 1 at a predetermined interval. As described above, after the spacer 3 is arranged on the surface of the first glass substrate 1, a seal portion 6 is formed on the peripheral portion 5 of the first glass substrate 1.

[0065] Next, the air in the sealed internal space 4 between the pair of glass substrates 1 and 2 is evacuated and depressurized, for example, by a rotary pump or the like through the exhaust pipe 7. Thereafter, the exhaust port is adhered and sealed with a metal lid (not shown) or the like. In this way, the multilayer glass 100 is manufactured.

[0066] The above describes one embodiment of the present disclosure, but the present disclosure is not limited to only the above embodiment, and various improvements and enhancements are possible.

[0067] In the above-described embodiment, an example in which the spacer 3 is made of a ceramic sintered body is shown. However, the spacer 3 may be formed of, for example, metal or resin. Examples of the metal include metals with relatively low thermal conductivity such as stainless steels such as SUS304 and SUS316, titanium, or titanium alloys. Examples of the resin include polyvinylidene fluoride, polychlorotrifluoroethylene, polytetrafluoroethylene, tetrafluoroethylene (PTFE), tetrafluoroethylene·perfluoroalkyl vinyl ether copolymer (PFA), or tetrafluoroethylene·hexafluoropropylene copolymer (ETFE). The spacer 3 may be a composite of different materials such as ceramics, metal, or resin. The first end portion 3211 and the central portion 31 may be made of different materials.

[0068] When the spacer 3 is formed of metal, by using the powder metallurgy method and adjusting the surface properties of the mold in contact with the powder, a spacer 3 having desired surface properties can be obtained. When the spacer 3 is formed of resin, by using the injection molding method and adjusting the surface properties of the mold in contact with the molten resin, a spacer 3 having desired surface properties can be obtained. A spacer 3 that is a composite of different materials can be obtained by separately manufacturing a plurality of members made of different materials and joining each member by adhesion or the like.

Explanation of reference numerals

[0069] 1 First glass substrate 2 Second glass substrate 3 Spacer 300 Side surface 301 First contact surface 302 Second contact surface 31 Central portion 3211 First end 3212 Second end 322 First contact surface 323 Second contact surface 4 Internal space 5 Peripheral portion 6 Seal portion 7 exhaust pipes 100 multilayer glasses

Claims

1. A spacer interposed between a first glass substrate and a second glass substrate facing each other and arranged in contact with the first glass substrate and the second glass substrate, a first contact surface arranged in contact with the first glass substrate, a second contact surface arranged in contact with the second glass substrate, a side surface located between the first contact surface and the second contact surface, a plate-shaped or columnar central portion, a first end portion protruding from the central portion, and a second end portion located on the side opposite to the first end portion and protruding from the central portion, comprising: the side surface is located at the outer edge of the central portion, the first contact surface is located at the first end portion, the second contact surface is located at the second end portion, the width perpendicular to the height direction of the first end portion is smaller than the width perpendicular to the height direction of the central portion, the average value RΔq1 of the root mean square slope in the roughness curve of the first contact surface is larger than the average value RΔq2 of the root mean square slope in the roughness curve of the side surface, a spacer.

2. The spacer according to claim 1, wherein the average value Rsk1 of kurtosis in the roughness curve of the first contact surface is larger than the average value Rsk2 of kurtosis in the roughness curve of the side surface.

3. The spacer according to claim 1, wherein the side surface is a fired surface.

4. The spacer according to claim 1, wherein the difference between the average value RΔq1 and the average value RΔq2 is 0.05 or more.

5. The spacer according to claim 1, wherein the average value RΔq1 is 0.7 or less.

6. The spacer according to claim 1, wherein the first end portion is spherical crown-shaped.

7. The spacer according to claim 1, wherein the height of the central portion is larger than the sum of the height of the first end portion and the height of the second end portion.

8. The spacer according to claim 1, wherein the area occupancy rate of pores in the first end portion is larger than the area occupancy rate of pores at the outer edge of the central portion.

9. The spacer according to claim 1, which is made of a ceramic sintered body mainly composed of zirconium oxide, mullite, forsterite, cordierite, steatite, alkali metal aluminosilicate, aluminum titanate or zinc oxide.

10. The spacer according to claim 1, which is made of a ceramic sintered body containing a composite compound of aluminum oxide and zirconium oxide.

11. the first glass substrate, the second glass substrate, an internal space located between the first glass substrate and the second glass substrate, The peripheral portion of the first glass substrate, A seal portion for sealing the peripheral portion, The spacer according to any one of claims 1 to 10, A multi-layer glass comprising the same.

12. The multi-layer glass according to claim 11, comprising an exhaust port for exhausting the internal space.

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