JPS60137850A - Production of mixed halide glass - Google Patents

Abstract

PURPOSE:To produce a transparent mixed halide glass having low absorption loss, by heating and melting a raw material added with an F-substitution additive, adding a halide other than fluoride to the obtained molten fluoride, and melting the mixture. CONSTITUTION:A raw material stable in a hydrated state, e.g. GaF3, ZnF2, etc., or an oxide raw material or other halide raw material is mixed with an additive for F-substitution (e.g. NH4F.HF), the mixture is heated and melted, and the impurities in the raw material is expelled to obtain a molten fluoride. The melt is added with a halide other than fluoride (e.g. CsCl), and melted again. A mixed halide glass having low water-content can be produced easily by this process.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing halide glass, and more particularly to a method for manufacturing a mixed halide glass for infrared transmission containing fluorine and halide ions other than fluorine.

Conventionally, when manufacturing fluoride glass, a method is known in which acidic ammonium fluoride (NH4F-HF) and ammonium chloride (NH+(J)) are added to raw material powder and then melted. 23 ZL?) This method is an effective method that can remove oxides and water in the raw material mixed powder of heptadide glass from the glass melt and reduce absorption loss due to oxygen bonding and OH. It was an indispensable method for removing unnecessary substances, especially when producing fluoride glass containing stable elements such as Ga and Zn in the form of crystallization water.

On the other hand, in the ongoing development of infrared transmitting glasses, attempts have been made to develop glasses containing two or more types of halide ions, fluorine ions and other halide ions, in order to obtain more stable glasses.

However, even if an attempt is made to create a glass containing two or more types of halide ions using the above method, the halide ions other than 7 atoms are expelled from the glass melt by the action of NH4F-HF, and the resulting glass contains the desired lI. (There was a drawback that they did not exist. Therefore, to produce glass containing two or more halide ions, there is usually a method in which the halide compound raw materials are mixed and melted as is without adding any additives, instead of using method L.) However, in this method, the fluoride that is the core of Ga1zn contains stable elements in the form of water of crystallization. This has the disadvantage that a good glass cannot be obtained because of the formation of grime in the glass and increased absorption loss.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for producing a mixed halide glass that can produce a mixed halide glass containing two or more types of halide ions in a transparent state with little absorption loss.

The present invention is a method for producing a mixed halide glass, characterized in that after adding an additive for fluorine substitution to produce a 7) compound melt, a halide other than fluorine is added and melted, When creating a heptadide melt, for example, a heptadide melt containing elements that are more stable in the form of crystal water than the heptadide molten material, such as a, Zn, etc., is used, for example, NH4F.
-Mixed halide obtained in a state with no residual ugliness or water using HF, and then mixed with raw materials containing other yuzu halogen ions and melted to obtain mixed halide glass with little residual oxygen or water. This is a method of manufacturing glass. In other words, the present invention is a method for reducing the amount of oxygen and water by primary melting.

According to the present invention, seven raw materials (such as GaF3.znF2, which are stable raw materials with water of crystallization, oxide raw materials, and other halide raw materials) that constitute a part of the target mixed halide glass are used. In order to melt together with the additive for element substitution, the impurities in the raw material (impurities as fluoride glass, oxygen and water) are expelled from the melt due to the additive for 7 element substitution, and the raw material Purity is improved. This melt is then transferred to secondary melting (mixed melting with other halides) after the additive for fluorination has been completely expelled. The halide glass melted during secondary melting does not contain any fluorine-substituted additives in the melt.
1” is melted as a mixed halide glass that maintains the anion ratio of fishing equipment.

Next, the present invention will be explained in more detail based on examples.
211mol%tGaF32gmol%pPbF24'/mol%rOsCg7%ru% (7) 1J14
7FtGa203sPbF, 2 and cscz raw materials were weighed, and 0s (excluding J<T7FyGa
The three components of 2O3rPbF2 and ammonium 7) acid (NH4F-HF), which is twice as strong as the theory for converting Ga2o3 to GaF3, were mixed, placed in a platinum crucible with a lid, and heated at 1Ioo°C. Heat treatment was performed in a furnace for 30 minutes to convert Ga2O3 to GaF3.

Thereafter, the furnace temperature was quickly raised to 100"C to evaporate the NH4F-HF remaining in the melt. The resulting melt was poured onto a brass plate, cooled to room temperature, and then finely ground. The mixture was mixed with C8Cl powder that had been weighed out in advance, and placed in a platinum crucible with a 7-point cap and melted for 00" cis minutes. Pour the irrigated melt onto a brass plate, press it down with another brass plate, and make the diameter tIomm, the thickness o,
A colorless and transparent disk-shaped particle of tmm was obtained. As shown in the X-ray diffraction pattern of FIG. 1, this powder was confirmed to be glassy since there were no sharp peaks characteristic of crystalline material. In addition, the infrared transmission properties of this fine particles were determined in 2. As a result of measurement in the range of t-23μm, as shown in Figure 2, 2.5μmNg
Translucency was observed for wavelengths in the range of , 0 μm. Here, the decrease in transmitted light of about 30% is considered to be due to a defect in the surface condition, and water absorption is observed at around 3 μm. This water absorption in QsO# powder and TIF-pbF2-G
This is thought to be caused by moisture that got mixed in during the handling of the aF3 glass, and it is thought that it will be possible to sufficiently reduce it through operational improvements such as handling under dry conditions.

Comparative Example t The composition of the final slurry in terms of raw material is T#F.
TlFrPb so that the ratio of
After weighing and mixing the raw materials for F2rGaF3C5CJ, they were placed in a platinum crucible with a 7-point cap and melted for 00"C7j. The resulting melt was poured onto a brass plate and pressed from above with another brass plate. A disc-shaped material with a diameter of 10 mm and a thickness of o and t mm was obtained.The inclination was colored grayish white, and the light transmittance was 73% or less.

Comparative Example 2 The composition of the finally obtained inverted slope is TIF
24 mol%, PbF241 mol%, GaF328 mol%
, T4F weighed to have a ratio of csc 17 mol%
.

A mixed powder of NH4I-1'.HF and NH4(J) was mixed with each raw material of PbF2+GaF31C6Cl at 20 u noz% of this raw material.

Here, the ratio between NH4F-HF and NH4(J) is determined so that the ratio of fluorine ions and chloride ions contained in the powder is equal to the ratio of 7] elemental ions and chloride ions in the target glass composition. After mixing these raw material powders well, they were placed in a platinum crucible with a 7-point cap and heated at 100°C in the air.
! Melting was carried out for r minutes. Pour out the obtained melt onto a brass plate and press it down with another brass plate to make a diameter of ttommm.
A disk-shaped 4n material with a thickness of o and smm was obtained. This inverted slope was colored grayish white, and the light transmittance was 75% or less.

Here, the difference between the example and this comparative example is that in the example, the ratio of fluorine ions and chloride ions is maintained accurately, whereas in this comparative example, the chlorine ions in the melt are NH4H
This is probably because the fluorine ions and chlorine ions are expelled by the action of F-HF, and the ratio of fluorine ions to chlorine ions is not maintained.

As is clear from the above examples, according to the method for producing a mixed halide glass of the present invention, a mixed halide glass with a low moisture content, which could not be obtained conventionally, can be easily obtained.

In the above example, the molten body obtained after the first melting was cooled, (vitrified) and pulverized, and then mixed with other halogen compounds and secondly melted, but the molten body obtained after the seventh melting was It is acceptable to directly add other halogen compound raw materials and mix them as a melt.

In addition, the halogen compound raw material added in the secondary melting may be a powder, whether it is one type of halogen compound, two or more types, or seven or more types of halogen ions. It does not matter whether it is a molten body or a molten body. The halogen compound added must have a low concentration of moisture and oxides, and the effect will be even higher if it has been pretreated to remove moisture and oxides.

Also, performing the secondary melting in an inert gas atmosphere such as Ng+Ar will shorten the melting time because the molten material will be collected during the secondary melting and will be prevented from accumulating in the glass. This is a more desirable method for producing mixed halide glass because it takes a long time and produces more homogeneous glass.

Figure 1 shows the X-ray diffraction pattern of the mixed halide glass obtained in the example of the present invention, and Figure 2 shows the infrared transmission characteristics of the mixed halide glass.

Claims (3)

[Claims] (1) In a method of manufacturing a mixed halide glass containing fluorine by heating and melting, an additive for 7-substitution is added to the raw material and this is heated to form a 7-solide melt, and then this A method for producing mixed halide glass, which comprises adding a halide other than fluoride to and melting the mixture. (2) The heptafluoride melt produced by adding additives is
The method for producing a mixed halide glass according to claim 1, which contains Ga-rin or Zn ions. (3) The method for producing a mixed halide glass according to claim 1 or 2, wherein the additive for fluorine substitution is NH4F-)iF.