JPH0416416B2 - - Google Patents
Info
- Publication number
- JPH0416416B2 JPH0416416B2 JP60210328A JP21032885A JPH0416416B2 JP H0416416 B2 JPH0416416 B2 JP H0416416B2 JP 60210328 A JP60210328 A JP 60210328A JP 21032885 A JP21032885 A JP 21032885A JP H0416416 B2 JPH0416416 B2 JP H0416416B2
- Authority
- JP
- Japan
- Prior art keywords
- base material
- quartz glass
- temperature
- heating furnace
- furnace
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 239000000463 material Substances 0.000 claims description 80
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims description 70
- 238000010438 heat treatment Methods 0.000 claims description 41
- 238000004519 manufacturing process Methods 0.000 claims description 15
- 239000011521 glass Substances 0.000 claims description 10
- 150000003377 silicon compounds Chemical class 0.000 claims description 6
- 239000010419 fine particle Substances 0.000 claims description 4
- 239000000377 silicon dioxide Substances 0.000 claims description 4
- 238000000151 deposition Methods 0.000 claims 1
- 230000003301 hydrolyzing effect Effects 0.000 claims 1
- 238000000034 method Methods 0.000 description 18
- 238000010304 firing Methods 0.000 description 16
- 238000004017 vitrification Methods 0.000 description 14
- 239000010453 quartz Substances 0.000 description 5
- VXEGSRKPIUDPQT-UHFFFAOYSA-N 4-[4-(4-methoxyphenyl)piperazin-1-yl]aniline Chemical compound C1=CC(OC)=CC=C1N1CCN(C=2C=CC(N)=CC=2)CC1 VXEGSRKPIUDPQT-UHFFFAOYSA-N 0.000 description 4
- 238000006243 chemical reaction Methods 0.000 description 4
- 239000005049 silicon tetrachloride Substances 0.000 description 4
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 3
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 239000007789 gas Substances 0.000 description 3
- 239000001307 helium Substances 0.000 description 3
- 229910052734 helium Inorganic materials 0.000 description 3
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 description 3
- 238000005245 sintering Methods 0.000 description 3
- 238000001308 synthesis method Methods 0.000 description 3
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 238000010574 gas phase reaction Methods 0.000 description 2
- 239000011261 inert gas Substances 0.000 description 2
- 239000011159 matrix material Substances 0.000 description 2
- 239000011148 porous material Substances 0.000 description 2
- 238000002791 soaking Methods 0.000 description 2
- 239000000758 substrate Substances 0.000 description 2
- 238000003786 synthesis reaction Methods 0.000 description 2
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- 229910003902 SiCl 4 Inorganic materials 0.000 description 1
- 229910004298 SiO 2 Inorganic materials 0.000 description 1
- 229910052786 argon Inorganic materials 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 239000012159 carrier gas Substances 0.000 description 1
- 238000007872 degassing Methods 0.000 description 1
- 229910001873 dinitrogen Inorganic materials 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 238000006460 hydrolysis reaction Methods 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 239000013307 optical fiber Substances 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- -1 photomask substrates Chemical compound 0.000 description 1
- 239000005373 porous glass Substances 0.000 description 1
- 230000035939 shock Effects 0.000 description 1
- AIFMYMZGQVTROK-UHFFFAOYSA-N silicon tetrabromide Chemical compound Br[Si](Br)(Br)Br AIFMYMZGQVTROK-UHFFFAOYSA-N 0.000 description 1
- 235000011121 sodium hydroxide Nutrition 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- ZDHXKXAHOVTTAH-UHFFFAOYSA-N trichlorosilane Chemical compound Cl[SiH](Cl)Cl ZDHXKXAHOVTTAH-UHFFFAOYSA-N 0.000 description 1
- 239000005052 trichlorosilane Substances 0.000 description 1
- 239000012808 vapor phase Substances 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
- C03B19/00—Other methods of shaping glass
- C03B19/14—Other methods of shaping glass by gas- or vapour- phase reaction processes
- C03B19/1453—Thermal after-treatment of the shaped article, e.g. dehydrating, consolidating, sintering
-
- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
- C03B37/00—Manufacture or treatment of flakes, fibres, or filaments from softened glass, minerals, or slags
- C03B37/01—Manufacture of glass fibres or filaments
- C03B37/012—Manufacture of preforms for drawing fibres or filaments
- C03B37/014—Manufacture of preforms for drawing fibres or filaments made entirely or partially by chemical means, e.g. vapour phase deposition of bulk porous glass either by outside vapour deposition [OVD], or by outside vapour phase oxidation [OVPO] or by vapour axial deposition [VAD]
- C03B37/01446—Thermal after-treatment of preforms, e.g. dehydrating, consolidating, sintering
-
- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
- C03B37/00—Manufacture or treatment of flakes, fibres, or filaments from softened glass, minerals, or slags
- C03B37/01—Manufacture of glass fibres or filaments
- C03B37/012—Manufacture of preforms for drawing fibres or filaments
- C03B37/014—Manufacture of preforms for drawing fibres or filaments made entirely or partially by chemical means, e.g. vapour phase deposition of bulk porous glass either by outside vapour deposition [OVD], or by outside vapour phase oxidation [OVPO] or by vapour axial deposition [VAD]
- C03B37/01446—Thermal after-treatment of preforms, e.g. dehydrating, consolidating, sintering
- C03B37/0146—Furnaces therefor, e.g. muffle tubes, furnace linings
Description
【発明の詳細な説明】
［産業上の利用分野］
本発明は、気相反応合成法によつて多孔質石英
ガラス母材を形成させ、これを加熱炉中で焼成し
て透明ガラスとする高純度石英ガラスの製造方法
に関するものである。Detailed Description of the Invention [Industrial Field of Application] The present invention is a method for producing transparent glass by forming a porous quartz glass base material by a gas phase reaction synthesis method and firing it in a heating furnace. The present invention relates to a method for producing pure quartz glass.
［従来の技術］
従来より、石英ガラスを製造する方法の一つと
して、気相反応合成法により多孔質石英ガラス母
材を形成し、この母材を加熱してガラス化する方
法が採用されている。すなわち、四塩化珪素等の
珪素化合物を酸水素炎中で加水分解させ、出発部
材である石英製の種棒（以下出発部材あるいは種
棒と書く）の下端部にシリカ微粒子を付着・堆積
させて多孔質石英ガラス母材を形成する。そし
て、この多孔質石英ガラス母材を加熱炉に入れ、
ヒータで加熱して母材を焼結することによりガラ
ス化する方法である。[Prior Art] Conventionally, one of the methods for manufacturing quartz glass has been to form a porous quartz glass base material by a vapor phase reaction synthesis method, and then heat this base material to vitrify it. There is. That is, a silicon compound such as silicon tetrachloride is hydrolyzed in an oxyhydrogen flame, and silica fine particles are attached and deposited on the lower end of a starting member, a quartz seed rod (hereinafter referred to as starting member or seed rod). Form a porous quartz glass matrix. Then, this porous quartz glass base material is placed in a heating furnace,
This is a method of vitrifying the base material by heating it with a heater and sintering it.
光フアイバーなどの製造に際しては、VAD法
といわれる石英ガラス製造方法が採用されてい
る。この方法は、気相反応合成法により種棒の下
端部にシリカ微粒子を付着・堆積させて多孔質石
英ガラス母材を形成させながら、徐々に引上げて
ヒータ中を通し、母材の上部から徐々にガラス化
する方法である。この方法では、多孔質石英ガラ
ス母材の形成と、この母材のガラス化とを連続的
に行なえる利点がある。 A silica glass manufacturing method called the VAD method is used to manufacture optical fibers. In this method, fine silica particles are attached and deposited on the lower end of the seed rod using a gas-phase reaction synthesis method to form a porous quartz glass base material, which is then gradually pulled up and passed through a heater, gradually starting from the top of the base material. This is a method of vitrification. This method has the advantage that the formation of a porous quartz glass base material and the vitrification of this base material can be performed continuously.
［発明が解決しようとする問題点］
しかしながら、フオトマスク基板などのように
大型の石英ガラスを製造しようとする場合、多孔
質石英ガラス母材を大口径で長尺のものにする必
要があり、その重量は、例えば径が30cmで長さ１
ｍの母材の場合１本当り約14Kg相当のものにな
る。このような大型の多孔質石英ガラス母材をガ
ラス化するに際して、上記VAD法を採用しよう
とすると、母材を上部から加熱してガラス化する
ため、種棒の下端近傍が先に軟化して下方につな
がる母材を支持することができず、下方の母材が
種棒の下端部近傍から分離して落下してしまう。
これを避ける手段として石英製種棒の径を太くす
ることも考えられるが、1400℃の温度条件下で上
記母材を支持させるためには種棒のコストが相当
高くなり実際的には困難である。[Problems to be Solved by the Invention] However, when attempting to manufacture large quartz glass such as photomask substrates, it is necessary to make the porous quartz glass base material large in diameter and long. For example, the weight is 30 cm in diameter and 1 in length.
In the case of a base material of m, each piece weighs approximately 14 kg. When attempting to vitrify such a large porous quartz glass base material using the VAD method described above, the base material is heated and vitrified from the top, so the area near the bottom end of the seed rod softens first. The lower base material cannot be supported, and the lower base material separates from the vicinity of the lower end of the seed rod and falls.
One way to avoid this is to increase the diameter of the quartz seed rod, but the cost of the seed rod would be considerably high in order to support the base material at a temperature of 1400°C, making it difficult in practice. be.
一方、上記問題を解決する方法として、多孔質
石英ガラス母材を加熱炉の上部から挿入し前記母
材をその底部から徐々に透明ガラス化させつつ前
記母材を下降させ種棒の下端部が1400℃の温度域
に達した時点で下降を停止する方法がある。しか
し一般的に前述の方法によつて製造される多孔質
石英ガラス母材は十分な強度を有しておらず、こ
のような母材を炉の上部から挿入して一段の工程
で、焼成かつ透明ガラス化しようとすると炉内の
気流の乱れによる熱シヨツクや焼結時の熱変形に
耐えられなくなり、焼成途中で多孔質石英ガラス
母材が崩れてしまい、大口径の石英ガラスを製造
することが出来なかつた。 On the other hand, as a method to solve the above problem, a porous quartz glass base material is inserted from the upper part of the heating furnace, and the base material is gradually turned into transparent glass from the bottom, and the base material is lowered so that the lower end of the seed rod becomes transparent. There is a way to stop the descent when the temperature reaches the 1400℃ range. However, the porous quartz glass base material produced by the above-mentioned method generally does not have sufficient strength, and such a base material is inserted from the top of the furnace and fired and fired in one step. If you try to make it transparent, it will not be able to withstand the heat shock caused by the turbulence of the airflow in the furnace and the thermal deformation during sintering, and the porous quartz glass base material will collapse during firing, making it difficult to manufacture large-diameter quartz glass. I couldn't do it.
本発明は上記の問題点を解決し、フオトマスク
基板用などの大型の高純度石英ガラスの製造方法
を提供することを目的とするものである。 SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and provide a method for manufacturing large-sized, high-purity quartz glass for photomask substrates.
［問題点を解決するための手段］
本発明は前記した問題点を解説すべくなされた
ものであり、珪素化合物を酸水素炎中で加水分解
して生成したリシカ微粒子を出発部材に付着・堆
積させて多孔質石英ガラス母材を形成させる第１
の工程と、該母材を炉の下部より上部に向けて高
まる温度勾配をもつ領域を少なくとも有する第１
の加熱炉の下端部から回転させながら徐々に引上
げる方法により1150〜1350℃の温度範囲で予備焼
成する第２の工程と、さらに前期第２の工程を経
た前記母材を炉の上部より下部に向けて高まる温
度勾配をもつ領域を少なくとも有する第２の加熱
炉の上部から回転させながら下降させる方法によ
り1400〜1500℃の温度範囲で徐々に透明ガラス化
する第３の工程とからなることを特徴とする高純
度石英ガラスの製造方法を提供するものである。[Means for Solving the Problems] The present invention has been made to solve the above-mentioned problems. The first step is to form a porous quartz glass matrix.
and a first step in which the base material has at least a region having a temperature gradient increasing from the bottom to the top of the furnace.
A second step of preliminary firing at a temperature range of 1150 to 1350°C by gradually pulling up the heating furnace from the lower end while rotating it, and further, the base material that has undergone the previous second step is moved from the upper part of the furnace to the lower part of the furnace. A third step of gradually turning the glass into transparent glass in a temperature range of 1,400 to 1,500 degrees Celsius by lowering it while rotating from the top of the second heating furnace, which has at least a region with a temperature gradient increasing toward The present invention provides a method for manufacturing characteristic high-purity quartz glass.
本発明において、多孔質石英ガラス母材は例え
ば第１図に示すような装置によつて製造される
（第１の工程）。すなわち、ボンベ１およびボンベ
２から水素および酸素がマスフロ−コントローラ
ー３，４を通して多重管バーナ５に供給される。
また四塩化珪素、トリクロロシラン、四臭化珪素
等の珪素化合物のガスが、タンク６からポンプ７
により熱交換器８を通して予熱され多重管バーナ
５に供給される。多重管バーナ５は反応室９内に
おいて酸水素炎を形成し、珪素化合物を加水分解
してシリカ微粒子を形成する。なお図示していな
いが、窒素、アルゴン等の不活性ガスもバーナ５
に供給され、これら珪素化合物のキヤリアガスと
してあるいは酸水素炎中のエアーカーテンとして
使用される。この加水分解反応の化学式を珪素化
合物が四塩化珪素である場合について示すと次式
の様になる。 In the present invention, a porous quartz glass base material is manufactured using, for example, an apparatus as shown in FIG. 1 (first step). That is, hydrogen and oxygen are supplied from cylinders 1 and 2 to multi-tube burner 5 through mass flow controllers 3 and 4.
In addition, gases of silicon compounds such as silicon tetrachloride, trichlorosilane, and silicon tetrabromide are supplied from the tank 6 to the pump 7.
The fuel is preheated through a heat exchanger 8 and supplied to the multi-tube burner 5. The multi-tube burner 5 forms an oxyhydrogen flame in the reaction chamber 9 and hydrolyzes the silicon compound to form silica fine particles. Although not shown, inert gases such as nitrogen and argon can also be used in the burner 5.
It is used as a carrier gas for these silicon compounds or as an air curtain in an oxyhydrogen flame. The chemical formula for this hydrolysis reaction when the silicon compound is silicon tetrachloride is as follows.
2H2＋O2→2H2O ……(1)
2H2O＋SiCl4→SiO2＋4HCl ……(2)
このシリカ微粒子が反応室９で出発部材として
鉛直に懸下された石英製種棒１０の下端部に付
着・堆積して順次成長し、大口径の多孔質石英ガ
ラス母材１１が形成される。なお、反応によつて
発生する塩酸は苛性ソーダ水と洗浄塔１３で向流
に接触して吸収除去される。 2H 2 +O 2 →2H 2 O ...(1) 2H 2 O+SiCl 4 →SiO 2 +4HCl ...(2) This silica fine particle is placed at the lower end of the quartz seed rod 10 suspended vertically as a starting member in the reaction chamber 9. The silica glass adheres to and accumulates on the parts and grows sequentially, forming a large-diameter porous quartz glass base material 11. Note that hydrochloric acid generated by the reaction comes into contact with the caustic soda water in a countercurrent flow in the washing tower 13 and is absorbed and removed.
本発明における第１の工程、第２の工程、第３
の工程を第２図に例示する。即ち第２図に示した
ように前記方法により第１の工程で製造された多
孔質石英ガラス母材１１を予備焼成用加熱炉２０
の下部に挿入し、種棒１０を回転させながら加熱
炉２０の上方に移動させ、多孔質石英ガラス母材
の上部より徐々に予備焼成させたのち、前記加熱
炉２０の上部から予備焼成母材１１を抜き出すよ
うにする。かかる予備焼成が終了したのち、ただ
ちに又は時間をおいて前記予備焼成母材１１を透
明ガラス化用加熱炉３０の上方まで移動し、該母
材１１を加熱炉３０の上部から挿入し、回転させ
ながら加熱炉３０の下部方向に移動させることに
より前記母材の下端部から徐々に透明ガラス化す
ることにより高純度な石英ガラスを製造する。な
お、前記母材の種棒の下端部近傍が加熱炉３０の
1400℃以上の高温域に達した時点で前記下部方向
への移動を停止させ、母材が種棒から落下するの
を防ぐ。 The first step, the second step, and the third step in the present invention
The process is illustrated in FIG. In other words, as shown in FIG.
The seed rod 10 is rotated and moved above the heating furnace 20 to gradually pre-fire the porous quartz glass base material from the top, and then the pre-fired base material is removed from the top of the heating furnace 20. Try to pull out 11. After the pre-firing is completed, the pre-baked base material 11 is immediately or after some time moved to the upper part of the heating furnace 30 for transparent vitrification, and the base material 11 is inserted from the top of the heating furnace 30 and rotated. By moving the base material toward the lower part of the heating furnace 30, the base material is gradually turned into transparent glass from the lower end, thereby manufacturing high-purity quartz glass. Note that the vicinity of the lower end of the seed rod of the base material is in the heating furnace 30.
When the temperature reaches a high temperature range of 1400°C or higher, the downward movement is stopped to prevent the base material from falling from the seed rod.
このように、多孔質石英ガラス母材を加熱炉の
下部から挿入し予備焼成したのち、透明ガラス化
域の温度が1400〜1500℃に保たれた加熱炉の上部
から下方に移動させて透明ガラス化するようにし
たので、本焼成過程で母材がこわれたり、又種棒
が熱変形してガラス化時に母材が落下したりする
ことがなくなる。さらにガラス化に伴なつて流出
する気泡ないし気泡中の気体は、まだガラス化さ
れていない母材上部の多孔質層を通つて上方へ逃
げることができるので、得られた石英ガラス中に
気泡等が含有されるのを防止できる。 In this way, the porous quartz glass base material is inserted from the bottom of the heating furnace and pre-fired, and then moved downward from the top of the heating furnace, where the temperature of the transparent vitrification area is maintained at 1400 to 1500℃, to form transparent glass. This prevents the base material from breaking during the main firing process, and prevents the seed rod from being thermally deformed and causing the base material to fall during vitrification. Furthermore, the bubbles that flow out during vitrification, or the gas in the bubbles, can escape upward through the porous layer above the base material that has not yet been vitrified. can be prevented from being contained.
本発明の好ましい態様によれば、多孔質石英ガ
ラス母材の予備焼成に用いる加熱炉は下部から上
部に向けて高まる温度勾配をもつようにヒータが
設けられている。このようにすれば、多孔質石英
ガラス母材を加熱炉に挿入するに際し、母材の温
度を徐々に高めていくことができ、これにより急
激な加熱により母材にクラツクが発生するのを防
止することができる。なお、温度勾配は多孔質石
英ガラス母材の挿入可能な温度が600℃以下であ
るため、炉の下部を500℃前後とし、母材の焼結
温度が1100℃以上で、1400℃以上の温度では石英
製種棒が熱変形して母材の重量に耐えられなくな
ることから炉の上部の温度を1150〜1350℃にする
のが適当である。さらにまた、前記予備焼成に用
いる加熱炉は、該加熱炉内上部に上下方向に温度
がほぼ均等な均温域を設け、該均温域の下部から
前記加熱炉内の下部に向けて低下する温度勾配を
有するものであつてもよい。こ場合、予備焼成の
作業条件の選択の自由度が高まる利点がある。 According to a preferred embodiment of the present invention, the heating furnace used for pre-firing the porous quartz glass base material is provided with a heater so as to have a temperature gradient increasing from the bottom to the top. In this way, when inserting the porous quartz glass base material into the heating furnace, the temperature of the base material can be gradually raised, thereby preventing cracks from occurring in the base material due to sudden heating. can do. The temperature gradient is set at around 500°C at the bottom of the furnace because the temperature at which the porous quartz glass base material can be inserted is 600°C or lower, and when the sintering temperature of the base material is 1100°C or higher, the temperature at 1400°C or higher is In this case, since the quartz seed rod is thermally deformed and cannot withstand the weight of the base material, it is appropriate to set the temperature at the upper part of the furnace to 1150 to 1350°C. Furthermore, the heating furnace used for the preliminary firing is provided with a uniform temperature area in the upper part of the heating furnace where the temperature is almost uniform in the vertical direction, and the temperature decreases from the lower part of the uniform temperature area toward the lower part of the heating furnace. It may have a temperature gradient. In this case, there is an advantage that the degree of freedom in selecting working conditions for pre-firing increases.
上記温度分布を有する加熱炉内に多孔質石英ガ
ラス母材を徐々に引上げながら予備焼成を行なう
が、この際の雰囲気はクリーンな方が好ましく必
要に応じてフイルター等で浄化された空気、窒素
ガス又はその他の不活性ガスを炉の下部より上方
に向けて導入しながら行なう。引上げ速度は加熱
炉中段の温度レベルや均温域の長さによつても異
なるが、例えば温度が1300℃で均温域の長さが20
cmの炉を用いた場合は250mm／Hr前後が適当であ
る。 Pre-firing is performed while gradually pulling the porous quartz glass base material into a heating furnace with the above temperature distribution, but it is preferable that the atmosphere at this time be clean, such as air purified with a filter, nitrogen gas, etc. as necessary. Or other inert gas is introduced upward from the bottom of the furnace. The pulling speed varies depending on the temperature level in the middle of the heating furnace and the length of the soaking zone, but for example, if the temperature is 1300℃ and the length of the soaking zone is 20
When using a cm furnace, approximately 250 mm/Hr is appropriate.
かかる予備焼成を行なつたのち隣接する加熱炉
の上方に母材を搬送し炉上部から下方に移動させ
ることにより前記母材を徐々に透明ガラス化する
が、この際の炉内雰囲気はHe濃度を70％以上好
ましくは80〜90％に保つて行なう。この前記母材
を徐々に透明ガラス化する際の加熱炉は上部から
下部にかけて高まる温度勾配が設けられているよ
うにするのが好ましい。この際の温度勾配は、多
孔質石英ガラス母材のガラス化温度が1400℃以上
であることから、加熱炉の上部を1200℃前後、炉
の下部の温度を1400〜1500℃にするのが適当であ
り、焼成に際して種棒の下端部近傍が1400℃以上
の高温域に達した時点で下降を停止するのが適当
である。さらにまた、前記透明ガラス化に用いる
加熱炉は、該加熱炉内下部に上下方向に温度がほ
ぼ均等な均温域を設け、該均温域の上部から前記
加熱炉内の上部に向けて低下する温度勾配を有す
るものであつてもよい。この場合、透明ガラス化
の作業条件の選択の自由度が高まる利点がある。 After performing such pre-firing, the base material is transported above the adjacent heating furnace and moved downward from the top of the furnace, thereby gradually turning the base material into transparent glass. At this time, the atmosphere in the furnace has a He concentration. 70% or more, preferably 80 to 90%. It is preferable that the heating furnace used to gradually convert the base material into transparent vitrification is provided with a temperature gradient that increases from the top to the bottom. Since the vitrification temperature of the porous quartz glass base material is 1400°C or higher, it is appropriate to set the temperature gradient at the upper part of the heating furnace to around 1200°C and the temperature at the lower part to 1400 to 1500°C. Therefore, during firing, it is appropriate to stop the descending when the vicinity of the lower end of the seed rod reaches a high temperature range of 1400° C. or higher. Furthermore, the heating furnace used for transparent vitrification is provided with a uniform temperature area in the lower part of the heating furnace where the temperature is almost uniform in the vertical direction, and the temperature decreases from the upper part of the uniform temperature area toward the upper part of the heating furnace. It may also have a temperature gradient. In this case, there is an advantage that the degree of freedom in selecting the working conditions for transparent vitrification is increased.
［実施例］
第２図Ａ，Ｂ，Ｃ，Ｄには、多孔質母材から透
明石英ガラスロツドまでを製造する装置・工程が
示されている。以下、本発明の実施例を図に従つ
て説明する。[Example] FIGS. 2A, B, C, and D show an apparatus and process for manufacturing a transparent quartz glass rod from a porous base material. Embodiments of the present invention will be described below with reference to the drawings.
第２図Ａに示すように、酸水素炎中で四塩化珪
素を加水分解させて石英製の種棒上にシリカの微
粒子を堆積・成長させて径が約30cm、長さ100cm
の多孔質石英ガラス母材１１を形成させた。この
母材を合成装置９の上方に引上げたのち、種棒を
ジヨイント部１５から切りはなし、隣接する場所
に設置された加熱炉２０の下部から挿入する。加
熱炉２０は下部から上部に向けて高まる温度勾配
を有しており、炉の下部が約500℃、炉の上部の
温度が約1300℃になるように制御されている。第
２図Ｂに示すように種棒１０をゆつくり矢印方向
に回転させながら、毎時10〜50cmの速度で上方に
引上げることにより多孔質石英ガラス母材１１を
ヒータ内に徐々に挿入し予備焼成を行なつた。こ
のため多孔質石英ガラス母材は上部から徐々に加
熱され、該多孔質石英ガラス母材中の気泡は外周
方向又は下部の低温部に移動し、内部の気泡が脱
泡されて前記多孔質石英ガラス母材はオープンポ
アーを残した状態で径方向・軸方向に収縮し、次
に行なう透明ガラス化が容易な予備焼成母材１２
となつた。かかる予備焼成が終了したのち、前記
母材を加熱炉２０の上部から抜き出し母材の寸法
を測定した結果、径が21cmで長さ81cmであつた。 As shown in Figure 2A, silicon tetrachloride is hydrolyzed in an oxyhydrogen flame to deposit and grow fine silica particles on a quartz seed rod, with a diameter of approximately 30 cm and a length of 100 cm.
A porous quartz glass base material 11 was formed. After this base material is pulled up above the synthesis apparatus 9, the seed rod is cut from the joint portion 15 and inserted from the lower part of the heating furnace 20 installed at an adjacent location. The heating furnace 20 has a temperature gradient that increases from the bottom to the top, and is controlled so that the temperature at the bottom of the furnace is about 500°C and the temperature at the top of the furnace is about 1300°C. As shown in FIG. 2B, the porous quartz glass base material 11 is gradually inserted into the heater by slowly rotating the seed rod 10 in the direction of the arrow and pulling it upward at a speed of 10 to 50 cm per hour. Fired. For this reason, the porous quartz glass base material is gradually heated from the top, and the air bubbles in the porous quartz glass base material move toward the outer periphery or to the low temperature part at the bottom, and the air bubbles inside are defoamed and the porous quartz glass base material is heated. The glass base material shrinks in the radial and axial directions while leaving open pores, and the pre-fired base material 12 is easily made into transparent glass.
It became. After the preliminary firing was completed, the base material was taken out from the upper part of the heating furnace 20 and the dimensions of the base material were measured and found to be 21 cm in diameter and 81 cm in length.
第２図Ｃに示すように、上記予備焼成母材１２
を隣接する加熱炉３０の上方に移動させ、種棒１
０をゆつくり回転させながら毎時およそ10cmの速
度で加熱炉３０の上部から徐々に下方に移動させ
ヒータ３１内に挿入させることにより多孔質石英
ガラス母材の下部より透明ガラス化させた。 As shown in FIG. 2C, the pre-fired base material 12
is moved above the adjacent heating furnace 30, and the seed rod 1
0 was slowly rotated at a speed of about 10 cm per hour from the top of the heating furnace 30 and gradually moved downward and inserted into the heater 31, thereby converting the porous quartz glass base material into transparent vitrification from the bottom.
この加熱炉３１は上記予備焼成母材１２が充分
挿入できる大きさを有しており、上部から下部に
向けて高まる温度勾配を有している。この温度勾
配は加熱炉の上部が約1200℃、下部が約1430℃に
なるように制御されている。図示されていない装
置により、炉の下部よりヘリウムガスを毎時1.3
m3／Hrの速度で導入し炉内のヘリウム雰囲気が
80〜90％になるように保たれている。炉内で多孔
質石英ガラス母材１２は下端部から徐々に加熱溶
融して脱泡がなされ、母材１２よりも径の小さな
透明石英ガラス１３になる。この際、気泡はまだ
透明ガラス化していない上部の多孔質ガラス層を
通つて外部に脱出するので、形成された石英ガラ
ス中に気泡が混入することはない。 The heating furnace 31 is large enough to allow the pre-fired base material 12 to be inserted therein, and has a temperature gradient that increases from the top to the bottom. This temperature gradient is controlled so that the upper part of the heating furnace is approximately 1200°C and the lower part is approximately 1430°C. A device (not shown) pumps helium gas from the bottom of the furnace at a rate of 1.3 per hour.
Helium is introduced at a rate of m 3 /Hr to create a helium atmosphere inside the furnace.
It is maintained at 80-90%. In the furnace, the porous quartz glass base material 12 is gradually heated and melted from the lower end to be degassed, and becomes a transparent quartz glass 13 having a smaller diameter than the base material 12. At this time, the air bubbles escape to the outside through the upper porous glass layer that has not yet become transparent vitrified, so that the air bubbles will not be mixed into the formed quartz glass.
第２図Ｄに示すように、種棒１０の下端部近傍
がヒータ３１の上端に達した時点で下降は停止し
透明ガラス化が終了する。従つて種棒１０の下端
部近傍が加熱変形することがなくなり、下方につ
ながる石英ガラス１３を落下させることなく支持
できる。また、種棒１０の下端部が熱変形するの
を防止できる。 As shown in FIG. 2D, when the vicinity of the lower end of the seed rod 10 reaches the upper end of the heater 31, the descent stops and transparent vitrification is completed. Therefore, the vicinity of the lower end of the seed rod 10 will not be heated and deformed, and the quartz glass 13 connected below can be supported without falling. Further, thermal deformation of the lower end of the seed rod 10 can be prevented.
［発明の効果］
以上説明したように、本発明によれば多孔質石
英ガラス母材を上部から加熱して徐々に予備焼成
し、次いで下端部から加熱して透明ガラス化する
二段焼成法を採用したので、大口径母材を焼成す
る際に急激な熱収縮により、母材に割れが発生し
たり、種棒が1400℃以上の高温にさらされて熱変
形し、母材が種棒下端部から落下したりするのを
防止できる。[Effects of the Invention] As explained above, according to the present invention, a two-stage firing method is employed in which a porous quartz glass base material is heated from the top to gradually pre-fire, and then heated from the bottom to become transparent vitrified. As a result, when firing a large-diameter base material, rapid heat shrinkage may cause cracks in the base material, or the seed rod may be exposed to high temperatures of 1400℃ or more and be thermally deformed, causing the base material to break at the bottom end of the seed rod. This can prevent it from falling from the room.
また母材径の増大に伴い焼成時の径方向の温度
差が大きくなつてくるが、本発明ではクローズド
ポアーが形成されない条件下で多孔質石英ガラス
母材を予備焼成して径を収縮させているので、透
明ガラス化時の径方向（外周部と中心部）の温度
差が小さくなり、脱泡が均一に進むので、高速で
透明ガラス化しても、石英ガラス中に気泡が混入
するのを防止できる。 Furthermore, as the base material diameter increases, the temperature difference in the radial direction during firing increases, but in the present invention, the porous quartz glass base material is pre-fired under conditions that do not form closed pores to shrink the diameter. As a result, the temperature difference in the radial direction (outer periphery and center) during transparent vitrification is reduced, and degassing proceeds uniformly, preventing air bubbles from entering the quartz glass even when vitrifying it at high speed. It can be prevented.
第１図は多孔質石英ガラス母材を得るための装
置の一例を示す説明図、第２図は本発明による透
明石英ガラス製造方法の実施例を示す説明図であ
り、Ａは多孔質石英ガラス母材を得る装置・工
程、Ｂは予備焼成の装置・工程、ＣとＤは透明ガ
ラス化の装置・工程を示す説明図である。
９……多孔質石英ガラス母材合成反応器、１０
……出発部材、種棒、１１……多孔質石英ガラス
母材、１２……予備焼成ずみ多孔質石英ガラス母
材、１３……透明石英ガラス、１５……ジヨイン
ト、２０，３０……加熱炉、２１，３１……ヒー
タ。
FIG. 1 is an explanatory diagram showing an example of an apparatus for obtaining a porous quartz glass base material, FIG. 2 is an explanatory diagram showing an example of the transparent quartz glass manufacturing method according to the present invention, and A is a porous quartz glass B is an explanatory diagram showing an apparatus and process for obtaining a base material, B is an apparatus and process for preliminary firing, and C and D are an apparatus and process for transparent vitrification. 9...Porous quartz glass base material synthesis reactor, 10
...Starting member, seed rod, 11...Porous quartz glass base material, 12...Prefired porous quartz glass base material, 13...Transparent quartz glass, 15...Joint, 20, 30...Heating furnace , 21, 31... heater.
Claims (1)
したシリカ微粒子を出発部材に付着・堆積させて
多孔質石英ガラス母材を形成させる第１の工程
と、該母材を炉の下部より上部に向けて高まる温
度勾配をもつ領域を少なくとも有する第１の加熱
炉の下端部から回転させながら徐々に引上げる方
法により1150〜1350℃の温度範囲で予備焼成する
第２の工程と、さらに前期第２の工程を経た前記
母材を炉の上部より下部に向けて高まる温度勾配
をもつ領域を少なくとも有する第２の加熱炉の上
部から回転させながら下降させる方法により1400
〜1500℃の温度範囲で徐々に透明ガラス化する第
３の工程とからなることを特徴とする高純度石英
ガラスの製造方法。 ２ 前記第１の加熱炉が、炉の下部より上部に向
けて高まる温度勾配をもつ領域の上方に該領域に
連続して、上下方向に温度がほぼ均等な均温域を
有することを特徴とする特許請求の範囲第１項記
載の高純度石英ガラスの製造方法。 ３ 前記の第２の加熱炉が、炉の上部より下部に
向けて高まる温度勾配をもつ領域の下方に該領域
に連続して、上下方向に温度がほぼ均等な均温域
を有することを特徴とする特許請求の範囲第１項
記載の高純度石英ガラスの製造方法。[Scope of Claims] 1. A first step of forming a porous quartz glass base material by adhering and depositing silica fine particles produced by hydrolyzing a silicon compound in an oxyhydrogen flame on a starting member, and the base material. The second heating furnace is pre-fired in a temperature range of 1150 to 1350°C by rotating and gradually pulling it up from the lower end of the first heating furnace, which has at least a region with a temperature gradient increasing from the bottom to the top of the furnace. 1400 by rotating and lowering the base material that has undergone the first step and the second step from the top of a second heating furnace, which has at least a region with a temperature gradient that increases from the top to the bottom of the furnace.
A method for producing high-purity quartz glass, comprising a third step of gradually turning it into transparent glass in a temperature range of ~1500°C. 2. The first heating furnace is characterized in that it has a uniform temperature area above and continuous with the area where the temperature gradient increases from the bottom to the top of the furnace, and where the temperature is approximately equal in the vertical direction. A method for producing high-purity quartz glass according to claim 1. 3. The second heating furnace is characterized in that it has a uniform temperature area below and continuous with the area where the temperature gradient increases from the top to the bottom of the furnace, and where the temperature is approximately equal in the vertical direction. A method for producing high-purity quartz glass according to claim 1.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP21032885A JPS6272536A (en) | 1985-09-25 | 1985-09-25 | Production of high-purity quartz glass |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP21032885A JPS6272536A (en) | 1985-09-25 | 1985-09-25 | Production of high-purity quartz glass |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6272536A JPS6272536A (en) | 1987-04-03 |
| JPH0416416B2 true JPH0416416B2 (en) | 1992-03-24 |
Family
ID=16587598
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP21032885A Granted JPS6272536A (en) | 1985-09-25 | 1985-09-25 | Production of high-purity quartz glass |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6272536A (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5066784B2 (en) | 2005-02-04 | 2012-11-07 | 旭硝子株式会社 | Method for producing synthetic quartz glass |
| JP2006219309A (en) * | 2005-02-08 | 2006-08-24 | Asahi Glass Co Ltd | Method and apparatus for producing porous quartz glass preform |
| WO2006088236A1 (en) * | 2005-02-18 | 2006-08-24 | Asahi Glass Co., Ltd. | Process for producing synthetic quartz glass, jig for synthetic-quartz-glass production, and synthetic quartz glass for optical member |
| JP5691384B2 (en) * | 2010-10-22 | 2015-04-01 | 住友電気工業株式会社 | Manufacturing method of glass base material |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS59174538A (en) * | 1983-03-24 | 1984-10-03 | Hitachi Cable Ltd | Manufacture of base material for optical fiber |
| JPS6217035A (en) * | 1985-07-15 | 1987-01-26 | Furukawa Electric Co Ltd:The | Production of base material for optical fiber |
| JPS6230636A (en) * | 1985-07-30 | 1987-02-09 | Furukawa Electric Co Ltd:The | Vitrification of optical fiber preform |
-
1985
- 1985-09-25 JP JP21032885A patent/JPS6272536A/en active Granted
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS59174538A (en) * | 1983-03-24 | 1984-10-03 | Hitachi Cable Ltd | Manufacture of base material for optical fiber |
| JPS6217035A (en) * | 1985-07-15 | 1987-01-26 | Furukawa Electric Co Ltd:The | Production of base material for optical fiber |
| JPS6230636A (en) * | 1985-07-30 | 1987-02-09 | Furukawa Electric Co Ltd:The | Vitrification of optical fiber preform |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6272536A (en) | 1987-04-03 |
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