Near infrared cutoff filter glass

Patent metadata

Field	Value
Publication number	US-9926221-B2
Application number	US-201615250010-A
Country	US
Kind code	B2
Filing date	Aug 29, 2016
Priority date	Apr 9, 2014
Publication date	Mar 27, 2018
Grant date	Mar 27, 2018

Abstract

To provide a near infrared cutoff filter glass which is excellent in optical properties such that the transmittance of visible light is high, and the transmittance of near infrared light is low. A near infrared cutoff filter glass comprising components of P, F, Al, R (R is at least one member selected from Li, Na and K), R′ (R′ is at least one member selected from Mg, Ca, Sr, Ba and Zn) and Cu, wherein (Cu + /the total amount of Cu)×100[%] is within a range of from 0.01 to 4.0%.

First claim

What is claimed is:

1. A near infrared cutoff filter glass comprising components of P, F, Al, R, R′ and Cu, wherein R is at least one member selected from Li, Na and K, R′ is at least one member selected from Mg, Ca, Sr, Ba and Zn, the near infrared cutoff filter glass comprises, as represented by cation %:
P 5+ : from 38.2 to 50%;
Al 3+ : from 5 to 15%;
R + : from 20 to 40%, wherein R + is the total amount of Li + , Na + and K + ;
R′ 2+ : from 5 to 30%, wherein R′ 2+ is the total amount of Mg 2+ , Ca 2+ , Sr 2+ , Ba 2+ and Zn 2+ ;
Cu 2+ : from 0.1 to 15%; and
Sb 3+ : from 0 to 1%, and as represented by anion %:
O 2− : from 30 to 90%; and
F − : from 10 to 70%, and
a ratio of an amount of Cu + to a total amount of Cu (Cu + /the total amount of Cu) is within a range of from 0.01 to 4.0%.

2. The near infrared cutoff filter glass according to claim 1 , wherein a content of Al 3+ is from 7 to 11.5%.

3. The near infrared cutoff filter glass according to claim 1 , wherein a content of Li + is at most 21.3%.

4. The near infrared cutoff filter glass according to claim 1 , wherein the ratio of the amount of Cu + to the total amount of Cu (Cu + /the total amount of Cu) is within a range of from 0.01 to 2.5%.

5. The near infrared cutoff filter glass according to claim 1 , wherein the ratio of the amount of Cu + to the total amount of Cu (Cu + /the total amount of Cu) is within a range of from 0.01 to 1.5%.

6. The near infrared cutoff filter glass according to claim 1 , wherein a value obtained by dividing an absorption coefficient at a wavelength of 400 nm of the near infrared cutoff filter glass by an absorption coefficient at a wavelength of 800 nm of the near infrared cutoff glass is within a range of from 0.00001 to 0.02.

7. The near infrared cutoff filter glass according to claim 1 , wherein a value obtained by dividing an absorption coefficient at a wavelength of 400 nm of the near infrared cutoff filter glass by an absorption coefficient at a wavelength of 800 nm of the near infrared cutoff glass is within a range of from 0.001 to 0.02.

8. The near infrared cutoff filter glass according to claim 1 , wherein a value obtained by dividing an absorption coefficient at a wavelength of 400 nm of the near infrared cutoff filter glass by an absorption coefficient at a wavelength of 800 nm of the near infrared cutoff glass is within a range of from 0.003 to 0.016.

9. The near infrared cutoff filter glass according to claim 1 , wherein in a thickness of 0.3 mm, the spectral transmittance at a wavelength of 400 nm of the near infrared cutoff filter glass is from 83 to 92%.

10. The near infrared cutoff filter glass according to claim 1 , wherein in a thickness of 0.3 mm, the spectral transmittance at a wavelength of 400 nm of the near infrared cutoff filter glass is from 85 to 90%.

Assignees

• Asahi Glass Co Ltd

Inventors

• Shiratori Makoto
• Yamaguchi Takeshi

Classifications

• G02B5/226

  Glass filters · CPC title

• C03C2204/00

  Glasses, glazes or enamels with special properties · CPC title

• C03C3/247 Primary

  containing fluorine and phosphorus · CPC title

• C03C4/082

  for infrared absorbing glass · CPC title

• G02B5/208

  for use with infrared or ultraviolet radiation, e.g. for separating visible light from infrared and/or ultraviolet radiation · CPC title