Glasses with high refractive power and low density

Patent metadata

Field	Value
Publication number	US-12570567-B2
Application number	US-202217725024-A
Country	US
Kind code	B2
Filing date	Apr 20, 2022
Priority date	Apr 20, 2021
Publication date	Mar 10, 2026
Grant date	Mar 10, 2026

Abstract

A glass includes a composition characterized by the following constituent phases (in mol-%): 20-80 lanthanum titanate; 10-50 lanthanum niobate; 0-60 lanthanum molybdenum borate; 2-40 lanthanum borate; 2-40 yttrium borate; 0-40 gadolinium borate; 2-40 zirconium silicate; 2-40 diboron trioxide; and 0-20 silicon dioxide. A refractive index is at least 2.00.

First claim

What is claimed is:

1 . A glass, comprising a composition which is characterized by the following constituent phases of the glass:

Min. (%
Max. (%

Constituent phase
by mol)
by mol)

lanthanum titanate
20
80

lanthanum niobate
10
50

lanthanum molybdenum borate
0
60

lanthanum borate
2
40

yttrium borate
2
40

gadolinium borate
0
40

zirconium silicate
2
40

diboron trioxide
2
40

silicon dioxide
0
 20;

wherein a refractive index n D calculated according to the following formula

n
D

=

4
⁢
πα

(

2.26
-

4
⁢
π

3

)

⁢
α

+

V
m

+
1

is at least 2.05, wherein α is a polarizability of a molecular unit of the glass and V m is a molecular volume.

2 . The glass of claim 1 , wherein the composition is characterized by the following constituent phases of the glass:

Min. (%
Max. (%

Constituent phase
by mol)
by mol)

lanthanum titanate
20
60

lanthanum niobate
20
40

lanthanum molybdenum borate
0
20

lanthanum borate
4
20

yttrium borate
4
20

gadolinium borate
0
20

zirconium silicate
4
20

diboron trioxide
4
20

silicon dioxide
0
 10.

3 . The glass of claim 1 , wherein a ratio of the portion of lanthanum titanate to the portion of lanthanum niobate is at least 0.7:1.

4 . The glass of claim 1 , wherein a sum of the portions of the constituent phases diboron trioxide and silicon dioxide is in a range of 4 to 20% by mol.

5 . The glass of claim 1 , wherein a density ρ of the glass calculated according to the following formula

ρ
=

∑

i
=
1

n

c
i

·

M
i

∑

i
=
1

n

c
i

·

M
i

ρ
i

is less than 5.30 g/cm 3 , wherein M i is a molar mass of each constitue

Assignees

• Schott Ag

Inventors

• Fotheringham Ulrich
• Ritter Simone Monika
• Rüdinger Bernd
• Nass Peter

Classifications

• G02C7/022

  Ophthalmic lenses having special refractive features achieved by special materials or material structures (G02C7/049 takes precedence) · CPC title

• C03C3/04 Primary

  containing silica · CPC title

• C03C3/068 Primary

  containing rare earths · CPC title