OPTICAL GLASS

• US 20180222786A1
• Filed: 08/10/2016
• Published: 08/09/2018
• Est. Priority Date: 08/14/2015
• Status: Active Grant

• Current Assignee: CDGM Glass Company Limited (Konica Minolta Inc.)
• Original Assignee: CDGM Glass Company Limited (Konica Minolta Inc.)
• Inventors: SUN, Wei
• Granted Patent: US 10,442,722 B2
• Time in Patent Office: Days
• CPC Class Codes: C03C 3/068 containing rare earths
• CPC Class Codes: C03C 3/155 containing zirconium, titanium, tantalum or niobium

Abstract

A high refraction low dispersion optical glass, the components thereof including, by weight percentage: B₂O₃: 1-30%; SiO₂: 0-20%; La₂O₃: 25-55%; Gd₂O₃: 5-40%; Y₂O₃: 0-25%; Yb₂O₃: 0-10%; Ta₂O₅: 0-10%; Nb₂O₅: 1-30%; TiO₂: 0-10%; ZrO₂: 0.5-20%; WO₃: 0-10%; ZnO: 0-15%; R₂O: 0-10%; RO: 0-10%; Al₂O₃: 0-10%; GeO₂: 0-10%; Bi₂O₃: 0-10%. A high refraction low dispersion environmentally friendly optical glass having excellent light transmittance may be obtained by reducing the Ta₂O₅ content within the glass components and introducing suitable amounts of rare earth oxide components having a high refraction low dispersion effect.

Claims

1. An optical glass, comprising by weight percentage:

B₂O₃;

1-30%;

SiO₂;

0-20%;

La₂O₃;

25-55%;

Gd₂O₃;

5-40%;

Y₂O₃;

0-25%;

Yb₂O₃;

0-10%;

Ta₂O₅;

0-10%;

Nb₂O₅;

1-30%;

TiO₂;

0-10%;

TiO₂/Nb₂O₅;

less than 0.3;

ZrO₂;

0.5-20%;

WO₃;

0-10%;

ZnO;

0-15%;

(ZnO+Y₂O₃)/La₂O₃;

less than 0.5;

R₂O;

0-10%, in which R₂O is one or more of Li₂O, Na₂O or K₂O;

RO;

0-10%, in which, RO is one or more of BaO, SrO, MgO or CaO;

Al₂O₃;

0-10%;

GeO₂;

0-10%;

Bi₂O₃;

0-10%;

the glass contains no PbO;

the glass refractive index is more than 1.85, and the Abbe number is 35-45.

2. The optical glass according to claim 1, further containing:

Sb₂O₃;

0-1%;

SnO₂;

0-1%;

CeO₂;

0-1%.

3. The optical glass according to claim 1, further containing B₂O₃:

5-25% and/or SiO₂;

0.1-15% and/or La₂O₃;

30-52% and/or Gd₂O₃;

5-35% and/or Y₂O₃;

1-20% and/or Ta₂O₅;

0-5% and/or Nb₂O₅;

2-25% and/or TiO₂;

0.1-5% and/or ZrO₂;

1-15% and/or WO₃;

0-5% and/or ZnO;

0-10% and/or R₂O;

0-5% and/or RO;

0-5% and/or Al₂O₃;

0-5% and/or GeO₂;

0-5% and/or Bi₂O₃;

0-5% and/or Sb₂O₃;

0-0.5% and/or SnO₂;

0-0.5% and/or CeO₂;

0-0.5%.

4. The optical glass according to claim 1, wherein SiO₂/(SiO₂+B₂O₃) is in the range of below 0.5;

and/or Y₂O₃/(La₂O₃+Gd₂O₃+Y₂O₃) is in the range of below 0.2, wherein Nb₂O₅ is greater than or equal to ZrO₂; and

/or Nb₂O₅/(Nb₂O₅+TiO₂+ZrO₂) is in the range of 0.4-0.8; and

/or (Nb₂O₅+Ta₂O₅+ZrO₂)/(SiO₂+B₂O₃) is in the range of less than 1; and

/or (ZnO+Y₂O₃)/La₂O₃ is in the range of 0.05-0.3.

5. The optical glass according to claim 1, wherein SiO₂/(SiO₂+B₂O₃) is in the range of 0.25-0.4;

and/or Y₂O₃/(La₂O₃+Gd₂O₃+Y₂O₃) is in the range of 0.05-0.12;

Nb₂O₅/(Nb₂O₅+TiO₂+ZrO₂) is in the range of 0.48-0.6; and

/or (Nb₂O₅+Ta₂O₅+ZrO₂)/(SiO₂+B₂O₃) is in the range 0.1-0.9; and

/or (ZnO+Y₂O₃)/La₂O₃ is in the range of 0.08-0.15.

6. The optical glass according to claim 1, wherein (Nb₂O₅+Ta₂O₅+ZrO₂)/(SiO₂+B₂O₃) ranges from 0.5 to 0.8.

7. The optical glass according to claim 1, wherein the glass refractive index ranges from 1.87 to 1.91, and the Abbe number ranges from 37 to 41.

8. The optical glass according to claim 1, wherein the glass refractive index ranges from 1.88 to 1.90, and the Abbe number ranges from 38 to 40.

9. A glass preform, made of the optical glass according to claim 1.

10. An optical element, made of the optical glass according to claim 1.