JPS6144733A - Halide glass for infrared light transmission - Google Patents

Abstract

PURPOSE:To make halide glass permeable to infrared light rays having wavelength up to the maximum 15mum, by using halide glass comprising one or more compounds of one or more halogenous elements of Cl, Br, and I, and K, Rb, Sr, Cd, Ba, and Pb in a desired ratio. CONSTITUTION:Halide glass for infrared light transmission comprising 0-24 mol% KX [X is one or more halogenous elements of Cl, Br, and I], 0-24mol% RbX, 2-30mol% SrX2; 34-53mol% CdX2, 8-40mol% BaX2, and 0-23mol% RbX2. SrX2+BaX2 is 11-42mol%, KX+RbX is 8-26mol%, KX+RbX+SrX2+ CdX2+BaX2+PbX2 is 90-100mol%, and (Cl)/(X) [(Cl) is number of Cl element in glass, and (X) is number of halogen elements in glass ] is controlled to 0.86- 1.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a halide glass that is transparent in a wide wavelength range from visible to far infrared.

[Prior art]

Today, the applications of optical fibers, for which research and development are becoming more active, include quartz glass, germania (Ge02), 1% glass, 7 Zirconium fluoride (ZrF4)-based glasses are being studied. However, the light transmission region of these glass fibers is from the visible light region to the near-infrared light region (2 to II μ
m), and could not be used as an energy transmitter.

Here, if a fiber is made of a material that is transparent from mid-infrared to far-infrared beyond ψμm, it will be a CO2 laser (wavelength 10.
Attm), Go laser (wavelength r,,zμm)
They are being developed because they can transmit optical energy emitted from sources such as light sources, and can be applied to optical waveguides for medical and industrial processing equipment.

There are three types of energy transmission fibers reported to date: halide crystal, chalcogenide glass, and hollow metal waveguide.

As a halide crystal, krillum halide (TIBr-
Tl! I), a polycrystalline body of silver halide (Ag (J-AgBr), and a single crystalline body of cesium iodide (O8I) are 2
However, it is said that it is difficult to reduce loss due to scattering at grain boundaries in the former, and scattering in lattice defects in the latter.
Furthermore, both had the disadvantage that the manufacturing process was extremely complicated.

On the other hand, it is difficult to reduce the loss of lucogenide glass due to absorption due to structural defects and absorption due to impurities, which are the essential characteristics of the material, and the transmission wavelength range is also limited to The limit was 9 μm.

In addition, the manufacturing process for metal hollow waveguides is complicated, and the
However, it was not possible to produce longer lengths, and furthermore, it was extremely difficult to reduce transmission loss.

It is said that the most promising material for A/L energy transmission fibers is non-septide halide glass. It has a very large atomic weight of chlorine, bromine, and iodine, so most of these byid compounds are 1
It has the property of being transparent in far infrared rays of 3 μm or more,
In addition, if it is a glass material, the scattering loss seen in crystal materials is extremely small, there are no structural defects like anodic chalcogenide glasses, and the manufacturing process is expected to be simplified.

However, it is transparent up to the far infrared region of ioμm or more, and I
:1 The reality is that no halide glass that is stable enough to be made into fibers has yet been reported. For example, the classically well-known zinc chloride (ZnC1
2) Glass has significant deliquescent properties, making it difficult to put it into practical use! Yes, other bismuth bismuth (Bi06
3) System i rough, , Xb lead oxide (Pt)Br2)
Since glass has a low glass transition temperature of 60°C or less, there is a risk that it will soften or crystallize during power transmission.

[Problems to be solved by the invention] The present invention has been made in order to eliminate the various drawbacks mentioned above. The purpose of the present invention is to obtain a halide glass that exhibits no chemical properties, has a high glass transition temperature, and is easy to manufacture.

? [Means for Solving the Problems] b In order to solve the above-mentioned problems, the present invention provides that when at least one halogen element selected from the group consisting of chlorine, bromine and iodine is expressed as X, mol% Expressed as KX O~+2t RbX 0-211 srx22~30 (idX2 J4Z-3; 3 BaX2 J'~110 pbx2 o~23 where 5rX2+BaX2 / /"-1
I2KX+RbX Za~2OtsuK
X+Rt)X+5rX2+CdX2+BaX2+PbX
2. To provide an infrared transmitting halide glass which is 90 to 100 and has a ratio of 6 to 100% of the number of chlorine elements in the glass to the number of halogen elements in the glass.

Here, even if Qd, Ba and Sr exist in the glass together with halide ions such as Cl ions, the wavelength λ, S~/Sμ
It is used as the main component of the glass of the present invention because it has no absorption in the infrared region of m and does not cause deliquescent properties in the glass. In addition, Sr and Ba also have the effect of improving the vitrification tendency when they coexist.

The compositional limitations of the glass of the present invention and their reasons will be described below.

First, the reasons for limiting the cation components will be described.
Cl, Br, I) will be collectively referred to as X for explanation.

Here, X is CA! It has the meaning of +Br1I and ■ means KC
It can also be expressed as l+KBr+KI. 0dX in glass
The content of 2 is 3'l-! ; 3 mol%, the content of B aX 2 is g ~ Furthermore, the content of each component is cax2 tto ~
30 mol%, BaX2/2~3 A% le%, 5
rx2'l"-2!; mol%, where BaX2 and 5r
The total of x2 is limited to 20 to 3 g mol%, and Ba
By keeping the molar ratio of X2 and 5rX2 from t to 3 to 2, a more stable glass body is obtained.

If the content of each component of 0dX2, BaX2 and 5rX2 is out of the above-mentioned limited range, the rate of crystallization during the cooling process from the melt increases, making it difficult to obtain a stable glass body.

■ Also acts as a cationic component for glass forming aids.
Even if RbX and PbX2 exist together with halogen ions such as Cl ions in the glass, they do not have any absorption in the infrared region of wavelength 2.3-20 μm, and the glass does not become deliquescent. This is a component that is preferably included.

The KX content of the glass of the present invention is 0 to 21 mol%, Rb
The content of X is O-2'l mol%, and KX and Rb
The total content with X is! '-, 24 mol%. In addition, the content of each component is expressed as KXj-/j mol%, RbX3-/
, 2 mol %, and by limiting the total of (1) and RbX to 70 to 20 mol %, an even more stable glass body can be obtained. Further, the content of pbx2 in the glass of the present invention is 0 to 23 mol%, preferably 2 to 7 mol%. ■
, RbX and pbx2 are outside the above-mentioned limited ranges, it becomes difficult to obtain a stable glass body because the crystallization rate during the cooling process of the melt for producing glass increases.

In addition, the glass of the present invention does not change its infrared transmission properties, and its stability against crystallization changes within the range of
T: Li+Na+Os, TA! Cationic components such as tAg+Zn can be added to the glass.

For example, the range in which it can be added is LiX O-1, NaX o
~10°C8X 0~g, TIX O~10. AgX
Onza, znx2o to y are each mol%, and the total of all these additives is 10 mol% or less. Each additive may be contained in an amount greater than each limited range, or the total amount of all additives may be 7.
If it exceeds 0 mol%, the melt during glass creation will become cloudy,
Since it becomes easy to crystallize, the properties of the glass of the present invention are lost.

Although chlorine ions are preferably used as the anionic component for constituting the glass of the present invention, it is possible to partially replace them with other halogen ions such as BRT. Here, the proportion of the anion component for constituting the glass of the present invention is Gl #; ~100 mol%. Here O/
If the content is less than mol %, the melt becomes cloudy and tends to crystallize, which is a drawback. The content of Br, which can be substituted, is preferably 0 to 74 mol%, and the content of Br, which can be substituted, is preferably 0 to 70 mol%. Here, if the content of Br and E exceeds the above limited range, the melt will become cloudy,
It may become easier to crystallize.

Next, the present invention will be explained in more detail based on examples.

〔Example〕

Example/All halogen compounds used in glass raw materials/20°C
High purity anhydrous crystals were used that had been dried in a dryer for at least 2 days. CdCl2 Q 4 Mok f-* BaO11p
, -21 mol%z 5rCJ29%/l'%z
KClza%le%, Rb(Jzamol%, Pb01
Cd (J2-B) prepared at a ratio of 2 g mol%
aC/2-8rGj? 2-K(J-Rb(J-PbCA
The mixed powder was placed in a quartz test tube with a diameter of iomm and a length of s:smm, and dried at 200"C for 12 hours in a chlorine gas atmosphere.Then, the furnace temperature was quickly raised to sro"c to The mixed powder was melted, and melting was carried out for about ψ hours while blowing 10 cc/min of chlorine gas into the melt.

Thereafter, the chlorine supply was stopped and dry nitrogen was blown into the melt at a rate of 10 cc/min for about 10 minutes. The obtained melt/! ;O'C
A quenched body having a length of 30 mm, a width of 10 mm and a thickness of 8/mm was obtained by pouring it between preheated brass plates with parallel spacing of about 1/2 mm. This rapidly cooled body.

was immediately stored in a dryer at 150°C, and
It was slowly cooled at a rate of C.

The X-ray diffraction pattern of the obtained quenched body is shown in Figure 1 (aJ).As is clear from Figure 1 (al), the sharp peaks seen in the case of crystalline solids are not observed in this quenched body. Therefore, it was confirmed that this material was a glass body.Additionally, when differential thermal analysis of this material was performed, a glass transition point (Tg) was observed around 733°C as shown in Figure 2. This confirms that this material is a glass body.Furthermore, the infrared transmission characteristics of this material measured by the direct transmission method are shown in Figure 3.From Figure 3, this material has a wavelength of 2.5~ It was found that there was no absorption over the range of 1S μm.
A decrease in transmitted light of 20-23% is also seen in
This is considered to be due to diffuse reflection caused by imperfections in the surface condition of the sample, and cannot be considered to be essential absorption.

Furthermore, even if this material is left in the air at temperatures above 50°C, no change in surface quality is observed, and even if it is left in the air at room temperature, the surface only becomes slightly cloudy and no deliquescence occurs. Not observed.

Example! ～//Cd072-Ba(J2-3r(J2-
The KCl-RbCl-PbC12 mixed powder was dried, melted, and cooled in exactly the same manner as in Example 1 to obtain thick glass materials as shown in Table 1. The fact that this material is in a glass state is confirmed by the fact that the scattering characteristic of anisotropic crystals is not observed when observed under a polarizing microscope, the sharp peaks characteristic of crystalline materials do not appear in the X-ray diffraction pattern, and the Tg is determined by differential thermal analysis (8c). Confirmed by observation and other methods. Table 1 shows the Tg of each glass measured by differential thermal analysis. When we investigated the infrared transmission characteristics of each material, we found that
Similarly, wavelength 2. ! No absorption occurred in the range of ;-/ta μm. As a representative example, the infrared transmission characteristics of the material of Example 2 are shown in FIG. In addition, the weather resistance of each of the obtained materials of Examples 2 to 2 horns showed almost the same results as in Example 1, and no deliquescent property was observed.

Examples 12 to 31 The first sample was dried at /20"C for 2 days or more in the same manner as in Example 1.
The mixed powders of Examples 72 to 3/, which were prepared using the various raw materials shown in the table in the proportions shown in Table 1, were dried, melted, and cooled in substantially the same manner as in Example/. A thick glass material as shown was obtained. Confirmation that the material was glassy was performed in the same manner as in Examples / to //. However, the atmosphere during melting was a chlorine atmosphere in Examples 12 to 7, and a nitrogen atmosphere in Examples 1 to 3. The weather resistance of these materials was not significantly different from that of the materials in Examples/Examples, and no deliquescent properties were observed.

Comparative Example/~5 Each of the mixed powders of Comparative Example/~S prepared using the same raw materials as in Example 1 and in the proportions shown in Table 1 was dried, melted, and cooled in the same manner as in Example 1. An opaque white material with a thickness of 0.2 mm or less was obtained. These materials were found to be crystalline since sharp diffraction peaks were observed in their X-ray diffraction patterns. As a representative example, the X-ray diffraction patterns of Comparative Example/and S are shown in FIG. 1(b) and (C). In addition, the infrared transmittance of these materials is 2° in wavelength! In the range of −25 μm, it was 5% or less.

〔Effect of the invention〕

As explained above, the infrared transmitting halide glass of the present invention was able to transmit infrared rays with a maximum wavelength of 1S μm. In addition, it was possible to relatively easily produce a sheet glass with a thickness of 10 mm or more, and it showed a high glass transition point of 130"C or more. For the above reasons, the halide glass for infrared transmission of the present invention has a wavelength of 10 mm or more. Not only can it be used for power transmission of .6 μm CO2 laser beams and 5.2 μm CO laser beams, but it can also be applied to optical waveguides for infrared thermometers in low-temperature areas.

Table 7 continued (1) Table 1 continued (2) Table 1 continued (3) Table 1 continued (4) FIG. 2 is a differential thermal analysis curve diagram of the material of Example 1. FIG. 3 and FIG. 1 are examples/and 2, respectively.
FIG. 3 is an infrared transmission characteristic diagram.

Front of mouth = 20 (&) Figure 1 Figure 2

Claims (4)

[Claims] (1) When at least one halogen element selected from the group consisting of chlorine, bromine, and iodine is expressed as X, expressed in mol%, KX 0-24 RbX 0-24 SrX_2 2-30 CdX_2 34-53 BaX_2 8~40 PbX_2 0~23 However, SrX_2+BaX_2 11~42KX+Rb
X 8~26 KX+RbX+SrX_2+CdX_2+BaX_2+
PbX_2 is 90 to 100, and the number of chlorine elements in the glass is 86 to 100% when expressed as a ratio to the number of halogen elements in the glass. (2) When at least one halogen element selected from the group consisting of chlorine, bromine, and iodine is represented as X, expressed in mol%, KX 5-12 RbX 5-12 SrX_2 4-25 CdX_2 40-50 BaX_2 12~36 PbX_2 2~17 However, SrX_2+BaX_2 20~38SrX_2
/BaX_2 2/3 or less KX+RbX 20 or less, the halide glass for infrared transmission according to claim 1. (3) When at least one halogen element selected from the group consisting of chlorine, bromine, and iodine is represented as X, it is expressed in mol% L1X 0-8 NaX 0-10 AgX 0-8 CSX 0-8 TlX The halide glass for infrared transmission according to claim 1 or 2, having a ZnX_2 of 0 to 10 0 to 8. (4) Claims 1 to 3 which have 0 to 14% bromine and 0 to 10% iodine when the number of bromine and iodine elements in the glass is expressed as a ratio to the number of halogen elements in the glass. Halide glass for infrared transmission as described.