Lithium containing glass with high and low oxidized iron content, and products using same

Patent metadata

Field	Value
Publication number	US-10202302-B2
Application number	US-201514712381-A
Country	US
Kind code	B2
Filing date	May 14, 2015
Priority date	Feb 24, 2012
Publication date	Feb 12, 2019
Grant date	Feb 12, 2019

Abstract

A low infrared absorbing lithium glass includes FeO in the range of 0.0005-0.015 wt. %, more preferably 0.001-0.010 wt. %, and a redox ratio in the range of 0.005-0.15, more preferably in the range of 0.005-0.10. The glass can be chemically tempered and used to provide a ballistic viewing cover for night vision goggles or scope. A method is provided to change a glass making process from making a high infrared absorbing lithium glass having FeO in the range of 0.02 to 0.04 wt. % and a redox ratio in the range of 0.2 to 0.4 to the low infrared absorbing lithium glass by adding additional oxidizers to the batch materials. A second method is provided to change a glass making process from making a low infrared absorbing lithium glass to the high infrared absorbing lithium glass by adding additional reducers to the batch material. In one embodiment of the invention the oxidizer is CeO 2 . An embodiment of the invention covers a glass made according to the method.

First claim

What is claimed is:

1. A glass composition consisting essentially of:

Component
Range

SiO 2
60-63
wt %

Na 2 O
10-12
wt %

Li 2 O
4-5.5
wt %

Al 2 O 3
17-19
wt %

ZrO 2
2-5
wt %

(Al 2 O 3 + ZrO 2 )
21.5-24
wt %

FeO
0.0005-0.015
wt %

Fe 2 O 3 (total iron)
50-less than 800 ppm;

and an oxidizer selected from the group of cerium oxide in the range of greater than 0 to 0.50 wt. % and/or manganese oxide in the range of greater than 0 to 0.75 wt. %, and a redox ratio in the range of 0.005-0.15, wherein the glass within the ultraviolet (“UV”) wavelength range of 295-395 nm has a transmission in the range of 50-85%; within a visible (“LTC/2°”) wavelength range of 395-775 nm has a transmission in the range of range of 89-92%;
within an infrared (“IR”) wavelength range of 775-2125 nm has a transmission in the range of range of 80-92%; and within a total solar energy transmittance (“TSET”) wavelength range of 275-2125 nm has a transmission in the range of 82-92%, wherein the glass has a thickness of 0.223 inch (5.7 millimeters).

2. The glass composition according to claim 1 , wherein cerium oxide is in the range of 0.01 to 0.15 wt. %.

3. The glass composition according to claim 1 , wherein the FeO is selected from one of the ranges of 0.0005 to 0.015 wt. % and 0.001 to 0.010 wt. %, the Fe 2 O 3 (total iron) is selected from one of the ranges of 0.005 to 0.06 wt. % and 0.005 to 0.03 wt. %, and the redox ratio is selected from one of the ranges of 0.005 to 0.15 wt. % and 0.005 to 0.10 wt. %.

4. A glass composition consisting essentially of:

Component
Range

SiO 2
60-63
wt. %

Na 2 O
10-12
wt. %

Li 2 O
4-5.5
wt. %

Al 2 O 3
17-19
wt. %

ZrO 2
3.5-5
wt. %

(Al 2 O 3 + ZrO 2 )
21.5-24
wt. %

FeO
0.0005-0.015
wt. %

Fe 2 O 3 (total iron)
800-1200
ppm;

and a redox ratio in the range of 0.006-0.13; and an oxidizer selected from the group of cerium oxide in the range of greater than 0 to 0.50 wt. % and/or manganese oxide in the range of greater than 0 to 0.75 wt. %, wherein glass within the ultraviolet (“UV”) wavelength range of 295-395 nm has a transmission in the range of 67-74%; the glass within a visible (“LTC/2°”) wavelength range of 395-775 nm has a transmission in the range of 88-90%: the glass within an infrared (“IR”) wavelength range of 775-2125 nm has a transmission in the range of 70-79%; and the glass within a total solar energy transmittance (“TSET”) wavelength range of 275-2125 nm has a transmission in the range of 78-84%, wherein the glass given above have a thickness of 0.223 inch (5.7 millimeters).

5. The glass composition according to claim 4 , wherein the FeO is selected from one of the ranges of 0.002 to 0.015 wt. %; 0.002 to 0.001 wt. %; 0.0035 to 0.001 wt. % and 0.003 to 0.0038 wt. %, the Fe 2 O 3 (total iron) is selected from one of the ranges of 0.08 to 0.12 wt. % and 0.09 to 0.10 wt. %, and the redox ratio is selected from one of the range of 0.01 to 0.13 and 0.015 to 0.10.

6. The glass composition according to claim 4 , wherein the FeO is in the range of 0.002-0.012 wt. %; the total iron is in the range of 0.08-0.12 wt. %; the redox ratio is in the range of 0.02 to 0.10.

7. A device for viewing radiated infrared energy, the device comprising a housing having at least one passageway, the passageway having a first open end and a second open end, a lens system for viewing radiated infrared energy, the improvement comprising: a chemically tempered ballistic glass lens mounted adjacent to one end of the passageway, the ballistic glass lens comprising a first surface, an opposite second surface and a glass segment between the first and the second surfaces of the ballistic glass lens, the glass segment consisting essentially of:

Component
Range

SiO 2
60-63
wt. %

Na 2 O
10-12
wt. %

Li 2 O
4-5.5
wt. %

Assignees

• Ppg Ind Ohio Inc

Inventors

• Goodwin George B
• Arbab Mehran
• Harris Caroline S
• Shelestak Larry J
• Blevins Calvin B
• Hartmann James V

Classifications

• C03C3/085 Primary

  containing an oxide of a divalent metal · CPC title

• B32B17/10119

  having a composition deviating from the basic composition of soda-lime glass, e.g. borosilicate · CPC title

• C03C4/10

  for infrared transmitting glass · CPC title

• B32B17/10045

  with at least one intermediate layer consisting of a glass sheet · CPC title

• C03C3/095

  containing rare earths · CPC title