JPS6144734A - 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 14mum, 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 of Cl, Br, and I], 0-24mol% RbX, 0-8mol% SrX2, 20-53mol% CdX2, 0-25 BaX2, and 24-60mol% PbX2. KX+RbX is 8- 24mol%, KX+RbX+CdX2+BaX2+PbX2 is 85-100mol%, and (Cl)/(X) [(Cl): number Cl elements in glass, and (X) is number of halogen elements in glass] is controlled to 0.75-1.

Description

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

[Prior Art] Glass bodies, unlike crystal bodies, can be easily formed into various shapes and have optical isotropy, so they have been used as optical media for a long time. Optical glass fibers (optical fibers), which are recently being used in optical communications, are one example of applications that take advantage of the characteristics of glass.
In addition to quartz (Si02) glass, which is already in practical use as a material for optical communication fibers, germania (
Ge02) type glass and zirconium heptadide (ZrF4
) type glasses are being considered.

On the other hand, as research into laser oscillation sources becomes more active, gas lasers having high output in the infrared wavelength region, such as carbon dioxide lasers (wavelength: 10.6 μm), have been developed. This high-energy infrared light is used in medical (laser scalpel), industrial (
It can be used in a wide range of applications (welding, cutting), and carbon dioxide laser processing machines are currently on the market. However, the laser energy transmission section of currently commercially available carbon dioxide laser processing equipment uses an articulated metal reflector, and this method is extremely lacking in versatility. There is a strong demand for fibers for However, the above-mentioned ordinary glass for optical communication has a light transmission wavelength range from visible to near-infrared (o,
4 kj μm), and in the infrared wavelength range beyond that, absorption occurs due to lattice vibration of the glass skeleton and becomes opaque, so the wavelength is 10. It could not be used for energy transmission such as μm.

Fibers for transmitting infrared energy that have been reported to date include halide crystals, chalcogenide glass, hollow metal waveguides, and halide glass. As a halide crystal, thallium halide (TlBr-T/I')
, polycrystalline silver halide (AgOA!-AgBr), and single crystalline cesium iodide (Cs).The former is caused by scattering at grain boundaries, and the latter is caused by scattering at lattice defects. It is said that it is difficult to reduce loss in both types, and both have the disadvantage that the manufacturing process is extremely complicated and productivity is low.

On the other hand, lucogenide glass cannot be used as an optical waveguide because it is difficult to reduce losses due to absorption due to structural defects, which are the essential characteristics of the material, and absorption of impurities such as boiled oxides. The wavelength range obtained is 7-9μ
It was limited to m.

Furthermore, the manufacturing process for metal hollow waveguides is complicated;
It had the disadvantage that it was not possible to make long sheets of several meters or more, and it was extremely difficult to reduce the transmission paper loss.

Therefore, non-septide-based halide glass has been cited as a promising candidate for energy transmission fiber material.

As is well known, the atomic weight of halogens (chlorine, bromine, iodine) is very large, and therefore most halide compounds have the property of being transparent to far infrared wavelengths of 151 tm or more. If a glass body can be obtained using this halide compound, the scattering loss seen in halide crystals will be extremely small, there will be no loss due to structural defects as in chalcogenide glass, and the manufacturing process will be significantly simplified, resulting in lower costs. It was expected that this material would become an optical transmitter with low energy consumption.

[Problem that the invention seeks to solve]

However, at present, no halide glass has been reported that is transparent to the far infrared region of 70 μm or more and is stable enough to be made into fibers. For example, the conventionally well-known zinc chloride (ZnC12) glass has significant deliquescent properties, making it difficult to put it to practical use.
iCl2)-based glasses and lead bromide (PbBr2)-based glasses have also been reported, but each has a glass transition temperature of 60"C.
Due to the low temperature below, there was a risk of softening or crystallization during power transmission.

The present invention was made to eliminate the various drawbacks mentioned above, and is transparent over a wide wavelength range from visible to /4'μm4', does not exhibit deliquescent property, has a high glass transition humidity, The purpose is also to obtain a ride glass that is easy to manufacture.

[Means for solving problems]

In order to solve the above-mentioned problems, the present invention provides the following formula: When at least one halogen element selected from the group consisting of chlorine, bromine, and iodine is expressed as X, expressed in mol%, 'l 5rX2 0 A-g cax2 , 2O-53 Bax20-, -. 2j pbx2xv~x.

However, KX+RbX, 1' ~ 2 lI
u+RbX+0dX2+BaX2+PbX2 1! ;
~100 and 73~1D when the number of chlorine elements in the glass is expressed as a ratio to the number of halogen elements in the glass
To provide a halide glass for transmitting infrared rays with a transmission rate of 0%. Here, cadmium (cd), lead (Pb), barium (Ba
) do not have any absorption in the infrared wavelength range of 2.1 to 71 μm even if they exist in glass together with halogen ions such as chlorine CO6), and do not cause deliquescence in the glass. It is the main component of the glass of the present invention.

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

First, the reason for limiting the cation component will be described. The /10 gen ion (
Cl, Br, ■) will be collectively referred to as X for explanation.

Here, X means Cl-Br 1, and ■ means KGl
It can also be expressed as +KBr+KI.

The content of CdX2 in the glass of the present invention is 20 to S3 mol%
, the content of PbX2 is 2'l/-A O%
, the content of BaX2 is 0-23 mol%. Furthermore, the content of each cation component is cax2: o-hirog mol%
A more stable glass body can be obtained by limiting the amounts of PbX to 22s to 1I mol% and BaX2 to 20 mol%.

If the contents of CdX 21 P b

On the other hand, it acts as a cationic component for glass forming aids■
, RbX and 5rX2 are glasses that do not have any absorption in the infrared region of wavelengths 2.5 to 73 μm even if they exist together with halogen ions such as Cl, and do not cause significant deliquescent properties in the glass. This is a component that is preferably included. The KX content of the glass of the present invention is O to J1 mol%, the RbX content is 0 to 2 q mol%,
5rX20~g mol%, and the total content of both K and Rb ions is g~21I mol%. Also KX,
Each content of RbX and 5rX2 is KXt ~ 72 mol%
, RbX 4'~/2 mol%, and 5rx2 o~g
The total content of Kx and RbX is 72 to 20 mol%.
By limiting the amount to mol%, a more stable glass body can be obtained.

(2) If each of the RbX and 5rx2 components is outside the above-mentioned limited range, the rate of crystallization during the cooling process from the melt during glass production will increase, making it difficult to obtain a stable glass body.

Furthermore, the glass of the present invention may contain NaX, OuX, ZnX r AgX, within a range that does not change its infrared transmission properties and does not change its stability against crystallization.
t Cationic components such as CsX and TdX can be added to the glass. For example, the possible addition range is NaX O-/(+, GuX O-r, znx O~O, AgX O~IO, C3XC1'l+TAX o~/
& each mole%, and the total of all these additives is 75 mole%
It is as follows. If each additive is contained in an amount greater than the respective limited range, or if the total amount of all additives exceeds 75 mol%, the melt during glass production will become cloudy and crystallization will occur more easily during cooling. lose.

Further, chlorine ions are preferably used as the halogen ion component for constituting the glass of the present invention, but a portion thereof can be replaced with at least one of bromine (Br) ions and iodine CI) ions. Here, the proportion of the ion component for constituting the glass of the present invention is 0/ion 73 to 100 mol%. Here, the content of Cl ions is 7! If it is less than mol %, it has the disadvantage that it tends to crystallize during the cooling process from the melt. In addition, the content of Br ions that can be substituted is 0 to 20
The mole% and Aion content is 0-2! ;mol%
is preferred. If the content of Br ions and Aions exceeds the above-mentioned limited range, the melt becomes cloudy and tends to crystallize.

〔Example〕

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

Example 1 All halogen compounds used in glass raw materials are 1.20'
High purity anhydrous crystals dried in a C dryer for at least 2 days were used. KO/g mol%, Rb(J mol%r C
dO,i! 2! jmol%, Pb012ko! mole%.

Place it in a quartz test tube with a length of 10 mm and a length of t mm, and heat it in a hydrogen chloride gas atmosphere. Drying was carried out at 10"C for 2 hours. Thereafter, the oven temperature was quickly raised to 10"C. However, the atmosphere during the temperature rise was a chlorine gas or nitrogen gas atmosphere. After the furnace temperature reached sio''CK and the mixed powder became a uniform melt, melting was carried out for about 2 hours while blowing hydrogen chloride gas into the melt at a rate of 1 occ per minute.Then, the hydrogen chloride gas was stopped. , instead, 1 occ/min of dry nitrogen was blown into the melt for about 10 minutes.The resulting melt was
The material was poured between brass plates preheated to .degree. C. and spaced parallel to each other with a spacing of approximately 1/2 mm to obtain a quenched body measuring 30 mm (vertical), 30 mm (width), and 8/mm (thick). This rapidly cooled body quickly 735
The sample was placed in a dryer at a temperature of 0.degree. C. and slowly cooled at a rate of 1.degree.

The X-ray diffraction pattern of the obtained quenched body is shown in Figure 1 (alK).As is clear from the ((trans)) in Figure 1, no sharp peaks characteristic of crystallinity were observed in this quenched body sample. from,
This material was confirmed to be a glass body. In addition, when differential thermal analysis of this material was performed, a glass transition point (Tg) was observed near 1lIll''C as shown in Figure 2, which also confirmed that this material was a glass body. Further, an infrared transmission characteristic diagram of this material measured by the direct transmission method is shown in Fig. 3. From Fig. 3, this material has a diameter of 20 gμm.

B, wavelength λ, S~/lIμm, excluding water absorption of 3μm
It was found that there was no absorption in the infrared wavelength region. Here, absorption due to OH stretching vibration of 20 gμm,
It can be seen that the intensity of absorption due to the bending vibration of the 3 μm H20 molecule is almost equal, and since the molar extinction coefficients of these two absorption bands are generally almost equal, 2. Most of the absorption in the 6.3 μm band is due to adsorbed water adhering to the material surface before and during the measurement, and it is thought that there is very little OH or H2O present inside the material.

Also, in FIG. 3, wavelength 2. ! ;-/! A decrease in transmitted light of 20 to 2 S% is observed over the entire iμm range, but this is due to diffuse reflection caused by imperfections in the surface condition of the material and cannot be considered to be an essential absorption of the material. Furthermore, even if this material is left in air at temperatures above 25°C for several days, no surface deterioration is observed; No phenomena were observed.

Examples 2 to 10 KCl-RbC1-Cd (lJ2-Pb
(J2-Ba (J, jl mixed powder) was dried, melted, and cooled in exactly the same manner as in Example/1 to obtain a thick colorless translucent material as shown in Table 1. This material The fact that it is in a glass state is confirmed by the fact that no scattering as seen in anisotropic crystals is observed under polarized light microscopy, that sharp peaks characteristic of crystalline materials do not appear in the X-ray diffraction pattern, and by differential thermal analysis. It was confirmed by methods such as observation of Tg. The Tg of each glass measured by differential thermal analysis is also shown in Table 1. When the infrared transmission characteristics of each material were investigated, it was found that Similarly, with the exception of water absorption, no absorption occurred in the wavelength range of 2.5 to /4' μm.As a representative example, when the material of Example 1 transmits infrared light,
The sex diagram is shown in Figure Q.

In addition, the weather resistance of each of the obtained materials of Examples 2 to io is almost the same as that of the material of Example 1, and in particular, Examples 7 and 10.
The material had excellent weather resistance.

Examples/1 to 30 Examples in which various raw materials shown in Table 7 were dried in 2Q'C for λ days or more in the same manner as in Example 1, and were prepared in the proportions shown in Table 1//- ! Example 1
By drying, melting, and cooling in substantially the same manner as above, a thick translucent material as shown in the first example was obtained.

However, the melting atmosphere in the case of Example//-# is
However, Examples 17 to 30 were conducted in a nitrogen atmosphere. Polarized light microscopy of these materials revealed that no light scattering was observed in the medium as seen in the case of optically anisotropic crystals, and Tg was observed by differential thermal analysis, as well as by KX-ray diffraction. The absence of sharp peaks characteristic of crystalline materials confirmed that these materials were glassy. None of these traits were observed.

Comparative Examples 1 to 7 Table 1 continued (1) Table 1 continued (2) Table 1 continued (3) Table 7 continued (4) Using the same raw materials as in Example/, as shown in Table 1 The mixed powders of Comparative Examples 1 to 7 prepared in the same proportions were dried, melted,
After cooling, an opaque white material with a thickness of less than 0 J mm was obtained. These materials were found to be crystalline since sharp diffraction peaks were observed in their X-ray diffraction patterns. Comparative example/3. ．． ! The X-ray diffraction pattern of ; is shown in Figure 1(b).

(C1, (dl). In addition, the infrared transmittance of these materials was 5% or less in the wavelength range of 2.3 to 2 j μm.

〔Effect of the invention〕

As explained above, the halide glass for transmitting infrared rays of the present invention was able to transmit infrared rays with wavelengths up to /4'μm. In addition, sheet glass with a thickness of 7 mm or more can be produced relatively easily, and most materials are 100"C
It showed a high glass transition point. Furthermore, lead chloride (PbC12), one of the main components, has low solubility in water, so by choosing a composition with a high content of PbC7!2, it became possible to obtain a glass body with excellent weather resistance. .

For the above reasons, the halide glass for infrared transmission of the present invention is suitable for use with a carbon dioxide laser with a wavelength of 1066 μm and a wavelength of 5.2 μm.
Not only can it be used as a transmission medium for laser beams in the mid-infrared wavelength range, such as μm carbon monoxide lasers, but it can also be applied to optical waveguides for infrared thermometers in low-temperature areas.

[Brief explanation of the drawing]

FIG. 1 is an X-ray diffraction diagram, and (a) to (dJ in the figure are the X-ray diffraction patterns of the materials of Example 11, Comparative Examples 1 and 3, and S, respectively. Fig. 3 and Fig. 1 are infrared transmission characteristic charts of Examples 11 and -, respectively. 1 Name of the invention Halide glass for infrared transmission 3 Relationship with the case of the person making the amendment Patent applicant address 4-8 Doshomachi, Higashi-ku, Osaka-shi, Osaka Name (
zoo) Nippon Sheet Glass Co., Ltd. Representative Makoto Saga
Ogu agent 7 Contents of amendment (11 Specification, page 10, line 10 to line l1 r 0sXO
-4J is corrected to [C3Xo~/IJ. (2) Example 2 in the Sample Thickness (mm) column of Table 1 (Continued) (3) on page 19 of the specification! ;-30VC compatible;
0.113J. "0.3/", "0.23J, [0,J7J,
``0.l13'', ``O, Otsu 0'' is replaced with ``0.I13''.
/-", "0.3", "o, η+ [o-IIJ r"
o, B + "Correct as 0.'J.

Claims (4)

[Claims] (1) When at least one halogen element selected from the group consisting of chlorine, bromine, and iodine is represented as X, expressed in mol%, KX 0-24 RbX 0-24 SrX_2 0-8 CdX_2 20-53 BaX_2 0~25 Pbx_2 24~60 However, KX+RbX 8~24 KX+RbX+CdX_2+BaX_2+PbX_2
85 to 100, and when the number of chlorine elements in the glass is expressed as a ratio to the number of halogen elements in the glass, 75
Halide glass for transmitting infrared rays up to 100%. (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 4-12 RbX 4-12 SrX_2 0-6 CdX_2 30-48 BaX_2 4-20 PbX_2 25-48 However, KX+RbX 12-20 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, expressed in mol%, NaX 0-10 CuX 0-5 ZnX 0-6 AgX 0-10 CSX The halide glass for infrared transmission according to claim 1 or 2, which has 0 to 14 TlX 0 to 15 . (4) Claims 1 to 3 which have 0 to 20% bromine and 0 to 25% 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.