JPH0524879A - Production of infrared ray transmitting glass - Google Patents

Abstract

PURPOSE:To obtain infrared ray transmitting glass having a low melt temperature, transmitting infrared rays to visible light rays, having low toxicity, comprising Ges, GeS2, Ge2S3 or GeS3. CONSTITUTION:Ges, GeS2, Ge2S3 or GeS3, a crystallization inhibitor and an optimizing agent of coefficient of thermal expansion are sealed in an quartz ampule in vacuum and heated and melted.

Description

Detailed Description of the Invention

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a chalcogenide infrared ray transmitting glass.

2. Description of the Related Art A human body sensor using a pyroelectric infrared sensor is widely used in home electric appliances and industrial equipment. For example, it is used as a sensor for opening and closing a door, a water faucet of a toilet, an operation of an air conditioner, and the like. Generally, 8 ~ 12μ from the human body
In order to collect m infrared rays efficiently, a filter or lens that transmits only infrared light is provided in front of the sensor.
Chalcogenide glass is drawing attention as a material for this filter. Chalcogenide glass is a glass containing a chalcogen element (sulfur, selenium, tellurium) as a main component, and practically, arsenic-sulfur, germanium-arsenic-
Selenium, germanium-selenium-tellurium, and germanium-selenium-antimony systems have been mainly researched and developed (for example, 31st Annual Meeting of Glass Conference, p.71-74 (19).
90)). However, the former two glasses contain arsenic,
There was a problem with toxicity. Also, since the latter two hardly transmit visible light, it is impossible to visually adjust the optical axis alignment between the lens and the sensor during assembly, and an expensive infrared imaging device (thermal imager) is required. It was Therefore, in order to solve the above problems, the inventors searched for chalcogenide glass containing a nontoxic element as a main component. The main elements of chalcogenide glass are sulfur, selenium, tellurium, germanium, arsenic and antimony.
Of these, arsenic and selenium are designated as poisons, but arsenic is particularly toxic. Selenium is contained in a large amount in tomato juice and is considered to be weak in toxicity because it is an essential nutrient for livestock. From the elements excluding arsenic, germanium and sulfur will be the main components under the condition that visible light is also transmitted. In addition to germanium and sulfur, this glass has iodine, antimony, in order to expand the infrared transmission range and suppress crystallization,
Tellurium, selenium, etc. were included. Furthermore, in order to optimize the coefficient of thermal expansion, small amounts of lithium, sodium, copper, silver,
Boron, gallium, indium, silicon, tin, lead,
It was made to contain bismuth, phosphorus, and bromine.

However, in the conventional manufacturing method as described above, when a glass mainly containing germanium and sulfur is manufactured, a raw material obtained by mixing germanium and sulfur so as to have a predetermined composition is made into quartz. A method of encapsulating under reduced pressure in an ampoule and melting this in an electric furnace was adopted. At this time, the vapor pressure of sulfur is extremely high at 10 atm at 640 ° C and 20 atm at 720 ° C, and the ampoule strength is not so strong that it can withstand up to 20 atm, so the temperature is slowly raised until the melting temperature is reached. There was a need. That is, if the temperature rises too fast, the internal pressure rises sharply, and the ampoule cannot withstand this and explodes, resulting in the risk of sulfur burning and causing a fire. In order to avoid such a danger, there is a problem that it takes a long time to manufacture this type of glass. The present invention solves such a problem, and an object of the present invention is to provide a method for producing infrared transparent glass, which has a low melting temperature, is safe, and does not require a long time for melting.

In order to solve such problems, the present invention is produced by adding any one of GeS, GeS ₂ , Ge ₂ S _{3 and} GeS ₃ as a raw material component in the production of glass. The result is a reduction in time and elimination of risks. Since germanium and sulfur have already formed compounds in these raw materials,
It melts quickly with increasing temperature.

[Operation] According to this method, for example, the melting point of GeS is 5
Since the melting point of GeS ₂ is 30 ° C. and the temperature of GeS ₂ is 800 ° C., the melting is completed at a temperature below the melting temperature of germanium. Therefore, the temperature rise is low and the vapor pressure of sulfur does not rise. On the other hand, when using germanium and sulfur as the raw materials, the melting point of germanium is 956 ° C and the melting point of sulfur is 120.
It was difficult to combine easily because ℃ was too far away, and so the vapor pressure was easy to rise because sulfur remained as a single substance up to a fairly high temperature. According to the method of the present invention, it is possible to safely manufacture chalcogenide glass that transmits infrared to visible light, has no toxicity, and is difficult to crystallize in a short time.

EXAMPLE An example of the present invention will be described below. (Example 1) Ge: S: I = 30: 60: 10 in atomic%
In order to produce 10 g of glass, 7.64 g of GeS ₂ and 2.36 g of I were added and vacuum sealed in a quartz ampoule. 6 hours in an electric furnace from room temperature to 600 ℃
4 hours from 00 ℃ to 800 ℃, 12 at 800 ℃
It melted for a time to obtain glass. The total melting time was 18 hours, the obtained glass was brown and 50% or more of infrared rays up to 11 μm were transmitted. Example 2 Ge: S: I = 22.5: 67 in atomic%.
To produce 10 g of 5:10 glass, 7.5 g of Ge
S ₃ and 2.5 g of I were added and vacuum sealed in a quartz ampoule. This in an electric furnace from room temperature to 600 ° C for 2 hours,
4 hours from 600 ℃ to 800 ℃, 1 at 800 ℃
It melted for 2 hours to obtain glass. The total melting time was 18 hours, the obtained glass was brown and 50% or more of infrared rays up to 11 μm were transmitted. Example 3 Ge: S: I = 32: 48: 20 in atomic%.
To produce 10 g of glass, 6.03 g of Ge ₂ S ₃
And 3.97 g of I were added and vacuum sealed in a quartz ampoule. 6 hours in an electric furnace from room temperature to 600 ℃
4 hours from 00 ℃ to 800 ℃, 12 at 800 ℃
It melted for a time to obtain glass. The total melting time was 18 hours, the obtained glass was brown and 50% or more of infrared rays up to 11 μm were transmitted. Example 4 Ge: S: I = 40: 40: 20 in atomic%.
In order to produce 10 g of glass, 6.23 g of GeS and 3.77 g of I were added and vacuum sealed in a quartz ampoule. 6 hours in an electric furnace from room temperature to 600 ℃
4 hours from 00 ℃ to 800 ℃, 12 at 800 ℃
It melted for a time to obtain glass. The total melting time was 18 hours, the obtained glass was brown and 50% or more of infrared rays up to 11 μm were transmitted. (Example 5) Ge: S: Sb = 30: 60: 1 in atomic%
To produce 10 g of 0 glass, 7.71 g of GeS ₂
And 2.29 g of I were added and vacuum sealed in a quartz ampoule. 6 hours in an electric furnace from room temperature to 600 ℃
4 hours from 00 ℃ to 950 ℃, 12 at 950 ℃
It melted for a time to obtain glass. The total melting time was 18 hours, the obtained glass was dark brown and 50% or more of infrared rays up to 11 μm were transmitted. (Example 6) Ge: S: Te = 23.75: 7 in atomic%
8.63 g to make 10 g of 1.25: 5 glass
GeS ₃ and 1.37 g of I were added and vacuum sealed in a quartz ampoule. This is heated in an electric furnace from room temperature to 600 ° C for 2 hours, 600 ° C to 900 ° C for 4 hours, then 90
Glass was obtained by melting at 0 ° C. for 12 hours. The total melting time was 18 hours, the glass obtained was blue and had a thickness of 11.5 μm.
50% or more of infrared rays were transmitted. (Example 7) Ge: S: I: Se = 21.2 in atomic%
To produce 10 g of 5: 63.75: 10: 5 glass, 6.83 g of GeS ₃ and 2.42 g of I and 7.52 g are prepared.
Se was added and vacuum sealed in a quartz ampoule. This was melted in an electric furnace from room temperature to 600 ° C. for 2 hours, from 600 ° C. to 900 ° C. for 4 hours, and further at 900 ° C. for 12 hours to obtain glass. The total melting time is 18 hours, the resulting glass is blue and 50% of the infrared up to 11.5 μm
The above was transmitted. (Comparative Example) To produce 10 g of Ge: S: I = 30: 60: 10 glass in atomic%, 4.06 g of Ge and 3.5
8g S and 2.36g I were added and vacuum sealed in a quartz ampoule. This in an electric furnace from room temperature to 600 ° C for 2 hours, 600 ° C to 800 ° C for 4 hours, then 800 ° C.
I tried to melt it for 12 hours, but the ampoule exploded at 750 ° C. As a result of detailed experiments, it was found that it is necessary to take 12 hours from room temperature to 600 ° C. and 12 hours from 600 ° C. to 800 ° C. to prevent the ampoule from exploding. As a result, the total melting time was 36 hours, which was twice as long as in Example 1. Also, the glasses of Examples 2 to 7 could be melted in a short time as in Example 1.

As is apparent from the above description of the embodiments, according to the present invention, the infrared transparent glass can be manufactured safely in a short time. Further, since the glass produced by this method also transmits visible light, the optical axis can be aligned with the naked eye when the lens is formed and assembled, and simple equipment is required. Moreover, since it uses chalcogenide glass, which is not toxic, it can be incorporated into consumer appliances and industrial equipment with confidence.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Akihiko Yoshida 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (1)

Claim: What is claimed is: 1. As a raw material component, Ge is used as a raw material in the production of infrared-transparent glass mainly containing germanium and sulfur.
A method for producing an infrared transparent glass containing any of S, GeS ₂ , Ge ₂ S _{3 and} GeS ₃ .