Alkali-free cover glass composition, and light extracting member using same
View Patent ↗A glass composition and a light extracting member using the same is provided, where the glass composition does not substantially contain a lead oxide and an alkali metal oxide and has a glass transition temperature of 530° C. or less and acid resistance property. An alkali-free cover glass composition is also provided which does not substantially contain a lead oxide and an alkali metal oxide; has a refractive index (n d ) of 1.7 to 2.3; has a glass transition temperature of 530° C. or less; has a dissolution depth of less than 1.3 μm as measured by an acid dipping weight loss measurement method; and contains 8 to 25% of Nb 2 O 5 in terms of mol % on the basis of an oxide thereof.
1. An alkali-free cover glass composition, which: does not substantially contain a lead oxide and an alkali metal oxide; has a refractive index (n d ) of 1.7 to 2.3; has a glass transition temperature of 530° C. or less; has a dissolution depth of less than 1.3 μm as measured and calculated by an acid dipping weight loss measurement method; and comprising, in terms of mol % on the basis of oxides thereof:
4 to 32% of ZnO;
5 to 35% of Bi 2 O 3 ;
10 to 30% of P 2 O 5 ;
8 to 25% of Nb 2 O 5 ; and
0 to 5% of BaO,
wherein when a content of the Bi 2 O 3 is 30 mol % or more, ZrO 2 is contained in an amount of 1 to 5%,
a value obtained by dividing a sum of a content of the Bi 2 O 3 and a content of the BaO by a content of the Nb 2 O 5 is 0.3 to 2.5.
2. An alkali-free cover glass composition, comprising, in terms of mol % on the basis of oxides thereof:
4 to 32% of ZnO;
5 to 35% of Bi 2 O 3 ;
10 to 30% of P 2 O 5 ;
8 to 25% of Nb 2 O 5 ; and
0 to 5% of BaO,
wherein when a content of the Bi 2 O 3 is 30 mol % or more, ZrO 2 is contained in an amount of 1 to 5%,
a value obtained by dividing a sum of a content of the Bi 2 O 3 and a content of the BaO by a content of the Nb 2 O 5 is 0.3 to 2.5, and
the alkali-free cover glass composition does not substantially contain a lead oxide and an alkali metal oxide.
3. The alkali-free cover glass composition according to claim 2 , comprising, in terms of mol % on the basis of oxides thereof:
0 to 17% of B 2 O 3 ;
0 to 5% of ZrO 2 ;
0 to 5% of MgO;
0 to 5% of CaO;
0 to 5% of BaO;
0 to 5% of SrO;
0 to 5% of TiO 2 ;
0 to 5% of V 2 O 5 ;
0 to 5% of MoO 3 ; and
0 to 20% of WO 3 .
4. A light extracting member, comprising:
a substrate;
a light-scattering layer having a light-scattering property and being placed on the substrate; and
an alkali-free cover glass layer being placed on the light-scattering layer and composed of a glass composition, wherein the glass composition does not substantially contain a lead oxide and an alkali metal oxide; has a refractive index (n d ) of 1.7 to 2.3; has a glass transition temperature of 530° C. or less; has a dissolution depth of less than 1.3 μM as measured by an acid dipping weight loss measurement method; and comprising, in terms of mol % on the basis of oxides thereof:
4 to 32% of ZnO;
5 to 35% of Bi 2 O 3 ;
10 to 30% of P 2 O 5 ;
8 to 25% of Nb 2 O 5 ; and
0 to 5% of BaO,
wherein when a content of the Bi 2 O 3 is 30 mol % or more, ZrO 2 is contained in an amount of 1 to 5%,
a value obtained by dividing a sum of a content of the Bi 2 O 3 and a content of the BaO by a content of the Nb 2 O 5 is 0.3 to 2.5.