US 12,421,166 B2
Chemically strengthened optical glass
Saya Kikkawa, Kanagawa (JP)
Assigned to OHARA INC., Kanagawa (JP)
Appl. No. 17/920,806
Filed by OHARA INC., Kanagawa (JP)
PCT Filed Mar. 24, 2021, PCT No. PCT/JP2021/012343
§ 371(c)(1), (2) Date Oct. 24, 2022,
PCT Pub. No. WO2021/215184, PCT Pub. Date Oct. 28, 2021.
Claims priority of application No. 2020-077383 (JP), filed on Apr. 24, 2020.
Prior Publication US 2023/0167019 A1, Jun. 1, 2023
Int. Cl. B32B 15/04 (2006.01); B32B 17/06 (2006.01); C03C 3/068 (2006.01); C03C 21/00 (2006.01)
CPC C03C 21/002 (2013.01) [C03C 3/068 (2013.01)] 17 Claims
 
1. A chemically strengthened optical glass including a compressive stress layer on a surface,
the chemically strengthened optical glass comprising, by mass % in terms of oxide:
2.0 to 20.0% of a SiO2 component;
5.0 to 35.0% of a B2O3 component;
20.0 to 60.0% of a La2O3 component;
2.0 to 25.0% of a TiO2 component;
2.0 to 15.0% of a Nb2O5 component,
more than 0% and 4.5% or less of a Li2O component;
wherein the sum of the Li2O component, a Na2O component, and a K2O component is more than 0% and 4.5% or less, and
an Hv change rate defined as [(Hvafter−Hvbefore)/Hvbefore]×100 is equal to or greater than 3.0%.