Glass plate and window
To provide a glass plate for a window material and a window comprising the glass plate, which are less likely to be a barrier to radio transmitting/receiving in use of a radio-utilizing apparatus, and a radio communication apparatus comprising the glass plate. A glass plate having a radio transmittance of at least 20% at a frequency of 100 GHz as calculated as 18 mm thickness, a window comprising the glass plate, and a radio communication apparatus comprising the glass plate.
1. A glass plate having a radio transmittance of at least 20% at a frequency of 100 GHz as calculated as 18 mm thickness,
wherein the glass plate contains, as represented by mol % based on oxides, the following components in the following contents:
55≤SiO 2 ≤75
1.3≤Al 2 O 3 ≤3.35
0≤B 2 O 3 ≤15
0≤MgO≤2.6
0≤CaO≤20
0≤SrO≤4
0≤BaO≤15
0≤Li 2 O≤0.01
0.1≤Na 2 O≤16
1≤K 2 O≤16
0≤ZrO 2 ≤2
0.001≤Fe 2 O 3 ≤5
0.001≤TiO 2 ≤1.5
1.1≤R 2 O≤20
0≤RO≤20
85≤SiO 2 +Al 2 O 3 +MgO+CaO+SrO+BaO+Li 2 O+Na 2 O+K 2 O+Fe 2 O 3 +TiO 2 ≤100
9.1≤7Al 2 O 3 +3MgO≤23.5
0.05≤Na 2 O/R 2 O≤0.8
1.1≤R 2 O+B 2 O 3 ≤22
0≤PbO<0.001
0≤ZnO≤8,
wherein R 2 O is a total content of alkali metal oxides, and RO is a total content of MgO, CaO, SrO and BaO, and
the glass plate has a NiO content of 0 mass ppm to 100 mass ppm.
2. The glass plate according to claim 1 , which contains, as represented by mol % based on oxides, the following components in the following contents:
60≤SiO 2 ≤74
1.5≤Al 2 O 3 ≤3.0
0≤B 2 O 3 ≤10
0.1≤MgO≤2.6
1≤CaO≤18
0≤SrO≤2.5
0.5≤BaO≤12
2≤Na 2 O≤15
1.5≤K 2 O≤13
0.5≤ZrO 2 ≤1.8
0.001≤TiO 2 ≤1
5≤R 2 O≤19
5≤RO≤18
98≤SiO 2 +Al 2 O 3 +MgO+CaO+SrO+BaO+Li 2 O+Na 2 O+K 2 O+Fe 2 O 3 +TiO 2 ≤100
10.8≤7Al 2 O 3 +3MgO≤23
0.1≤Na 2 O/R 2 O≤0.75
5≤R 2 O+B 2 O 3 ≤20
0≤ZnO≤6.
3. The glass plate according to claim 1 , which contains substantially no NiO.
4. The glass plate according to claim 1 , wherein the content of Na 2 O, as represented by mol % based on oxides, is:
0.1≤Na 2 O≤11.
5. The glass plate according to claim 1 , which has a radio transmittance of at least 25% at a frequency of 100 GHz as calculated as 18 mm thickness.
6. The glass plate according to claim 1 , which has a radio transmittance of at most 84% at a frequency of 100 GHz as calculated as 18 mm thickness.
7. The glass plate according to claim 1 , which satisfies, when plane waves at a frequency of 10 GHz at an electric field strength of 1 V/m are made to enter the glass plate having a thickness of 1.2λ, from a wave source 2λ apart from an opening, a linear approximation of y>(0.0607×x), wherein y (V/m) is the electric field strength at a measurement point 10λ apart from the opening, and x is a value obtained by dividing the opening area S (mm 2 ) by λ 2 .
8. The glass plate according to claim 1 , which satisfies an exponential approximation of y′>exp(−0.081×x′), wherein y′ is the approximate transmittance at a frequency of 100 GHz, and x′ is the thickness (mm) of the glass plate.
9. The glass plate according to claim 1 , which satisfies an exponential approximation of the relation between the frequency x″ and the radio transmittance y″ at a frequency of from 6 to 20 GHz, as calculated as 18 mm thickness, approximated to a function y″=[constant 1]×e [constant 2]×x″, of y″> 0.8619e −0.015x″ .
10. The glass plate according to claim 1 , which has a specific gravity of from 2.40 to 3.00, a Young's modulus of from 60 GPa to 100 GPa and an average coefficient of linear expansion from 50° C. to 350° C. of from 35×10 −7 to 120×10 −7 .
11. The glass plate according to claim 1 , which has a Na 2 O elution amount in a water resistance test of from 0.001 mg to 0.6 mg.
12. The glass plate according to claim 1 , wherein T 2 is at most 1,750° C., T 4 is at most 1,350° C., and T 4 -T L is at least −150° C., wherein (T 2 is a temperature at which the glass viscosity becomes 10 2 (dPa·s), T 4 is a temperature at which the glass viscosity becomes 10 4 (dPa·s), and T L is the liquid phase temperature of the glass.
13. The glass plate according to claim 1 , which has a glass transition point Tg of from 400° C. to 750° C.
14. The glass plate according to claim 1 , which has a visible light transmittance T VA of from 30 to 92% as calculated as 3.85 mm plate thickness.
15. The glass plate according to claim 1 , which has a solar direct transmittance Te of from 35 to 91% as calculated as 3.85 mm plate thickness.
16. The glass plate according to claim 1 , wherein A x radio transmittance is from 0.0225 m 2− % to 8,400 m 2− %, wherein A is the area (m 2 ) of the glass plate.
17. The glass plate according to claim 1 , wherein radio transmittance/t is from 0.7%/mm to 84%/mm, wherein t is the thickness (mm) of the glass plate.
18. The glass plate according to claim 1 , which has an area of at least 900 mm 2 .
19. A window comprising the glass plate as defined in claim 1 .
20. The window according to claim 19 , which is for an automobile or for a building.
21. A radio commtmication apparatus comprising the glass plate as defined in claim 1 .