JPH04331730A - Method for heat-treating porous glass body - Google Patents
Method for heat-treating porous glass bodyInfo
- Publication number
- JPH04331730A JPH04331730A JP12671991A JP12671991A JPH04331730A JP H04331730 A JPH04331730 A JP H04331730A JP 12671991 A JP12671991 A JP 12671991A JP 12671991 A JP12671991 A JP 12671991A JP H04331730 A JPH04331730 A JP H04331730A
- Authority
- JP
- Japan
- Prior art keywords
- glass
- glass body
- porous glass
- porous
- heat
- 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.)
- Pending
Links
- 239000005373 porous glass Substances 0.000 title claims abstract description 46
- 238000000034 method Methods 0.000 title claims abstract description 18
- 239000011521 glass Substances 0.000 claims abstract description 54
- 238000010438 heat treatment Methods 0.000 claims abstract description 27
- 239000000463 material Substances 0.000 claims description 23
- 238000000151 deposition Methods 0.000 abstract description 2
- 230000001678 irradiating effect Effects 0.000 abstract 1
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 17
- 238000004017 vitrification Methods 0.000 description 8
- 239000007789 gas Substances 0.000 description 7
- 239000000377 silicon dioxide Substances 0.000 description 7
- 230000018044 dehydration Effects 0.000 description 6
- 238000006297 dehydration reaction Methods 0.000 description 6
- 239000010419 fine particle Substances 0.000 description 5
- 239000013307 optical fiber Substances 0.000 description 5
- 235000012239 silicon dioxide Nutrition 0.000 description 5
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 4
- 238000005253 cladding Methods 0.000 description 3
- 239000000835 fiber Substances 0.000 description 3
- 239000010453 quartz Substances 0.000 description 3
- 229910052681 coesite Inorganic materials 0.000 description 2
- 238000004891 communication Methods 0.000 description 2
- 229910052906 cristobalite Inorganic materials 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- 229910052682 stishovite Inorganic materials 0.000 description 2
- 229910052905 tridymite Inorganic materials 0.000 description 2
- KZBUYRJDOAKODT-UHFFFAOYSA-N Chlorine Chemical compound ClCl KZBUYRJDOAKODT-UHFFFAOYSA-N 0.000 description 1
- 238000000149 argon plasma sintering Methods 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000012467 final product Substances 0.000 description 1
- YBMRDBCBODYGJE-UHFFFAOYSA-N germanium oxide Inorganic materials O=[Ge]=O YBMRDBCBODYGJE-UHFFFAOYSA-N 0.000 description 1
- 230000020169 heat generation Effects 0.000 description 1
- 239000001307 helium Substances 0.000 description 1
- 229910052734 helium Inorganic materials 0.000 description 1
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 239000002912 waste gas Substances 0.000 description 1
Classifications
-
- 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
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Physics & Mathematics (AREA)
- General Chemical & Material Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Thermal Sciences (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Manufacturing & Machinery (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- Manufacture, Treatment Of Glass Fibers (AREA)
- Glass Melting And Manufacturing (AREA)
Abstract
Description
【０００１】0001
【産業上の利用分野】本発明は通信、光学の分野で用い
られる光ファイバ母材、イメージファイバ母材、ライト
ガイド母材、ロッドレンズの母材などを作製するための
技術に関し、より詳しくは、透明ガラス棒の外周に堆積
された多孔質ガラス体を脱水および／または透明ガラス
化するための熱処理方法に関する。[Industrial Application Field] The present invention relates to a technology for producing optical fiber preforms, image fiber preforms, light guide preforms, rod lens preforms, etc. used in the fields of communication and optics. , relates to a heat treatment method for dehydrating and/or vitrifying a porous glass body deposited on the outer periphery of a transparent glass rod.
【０００２】0002
【従来の技術】外付け法を介して石英系ガラス母材を製
造するとき、コア用とした透明ガラス棒の外周にクラッ
ド用の多孔質ガラス体を外付けした後、所定の雰囲気ガ
スを含む高温の雰囲気下で多孔質ガラス体を熱処理して
、多孔質ガラス体を脱水、透明ガラス化している。ちな
みに、周知の電気炉を用いる方法では、塩素ガス、ヘリ
ウムなどの雰囲気ガスで満たされた炉心管内に多孔質ガ
ラス体を入れ、炉心管の外周に設けられたヒータにより
多孔質ガラス体を加熱して、これの脱水、透明ガラス化
を行なっている。[Prior Art] When manufacturing a silica-based glass base material through an external attachment method, a porous glass body for a cladding is externally attached to the outer periphery of a transparent glass rod used for a core, and then a predetermined atmospheric gas is added. The porous glass body is heat-treated in a high-temperature atmosphere to dehydrate the porous glass body and turn it into transparent glass. By the way, in the well-known method of using an electric furnace, a porous glass body is placed in a furnace core tube filled with atmospheric gas such as chlorine gas or helium, and the porous glass body is heated by a heater installed on the outer periphery of the furnace core tube. This is then dehydrated and made into transparent glass.
【０００３】0003
【発明が解決しようとする課題】上述した電気炉による
熱処理の場合、多孔質ガラス体の脱水または透明ガラス
化が、これの外周から中心に向けて進行するために内部
の脱水や脱泡が十分に行なわれず、透明ガラス化後のガ
ラス中に水分や気泡が残存する。[Problems to be Solved by the Invention] In the case of heat treatment using the above-mentioned electric furnace, the dehydration or transparent vitrification of the porous glass body proceeds from the outer periphery to the center, so that the internal dehydration and defoaming are sufficient. However, water and air bubbles remain in the glass after it has been made transparent.
【０００４】ガラス中に水分や気泡が残留すると、最終
製品である光ファイバの伝送特性が光の散乱損失により
低下し、ガラスの亀裂、破損なども生じる。[0004] If moisture or air bubbles remain in the glass, the transmission characteristics of the final product, the optical fiber, will deteriorate due to light scattering loss, and the glass may crack or break.
【０００５】本発明に係る多孔質ガラス体の熱処理方法
は、このような技術的課題に鑑み、ガラス中に水分や気
泡を残存させることのない多孔質ガラス体の熱処理方法
を提供しようとするものである。[0005] In view of the above-mentioned technical problems, the heat treatment method for a porous glass body according to the present invention aims to provide a method for heat treatment for a porous glass body that does not leave moisture or air bubbles in the glass. It is.
【０００６】[0006]
【課題を解決するための手段】本発明に係る熱処理方法
は、所期の目的を達成するため、ガラス棒の外周に多孔
質ガラス体が堆積されたガラス母材において、その多孔
質ガラス体を熱処理するとき、ガラス母材にマイクロ波
を照射して、ガラス棒、多孔質ガラス体を発熱させるこ
とを特徴とする。[Means for Solving the Problems] In order to achieve the intended purpose, the heat treatment method according to the present invention is to treat a porous glass body in a glass base material in which a porous glass body is deposited on the outer periphery of a glass rod. During heat treatment, the glass base material is irradiated with microwaves to generate heat in the glass rod and porous glass body.
【０００７】[0007]
【作用】上述した誘電体加熱による発熱量は、εｔａｎ
δを材料の固有値、ｆをマイクロ波の振動数とした場合
、εｔａｎδ・ｆに比例する。上述したガラス母材にお
いて、ガラス棒は、透明な石英系ガラスからなり、多孔
質ガラス体は、石英系ガラス微粒子の堆積物からなり、
水分を含んでいる。これらのうち、水分はε＝８０で最
もｔａｎδが大きく、ガラス棒はε＝２、多孔質ガラス
体のガラス微粒子はε≒１．１である。[Operation] The amount of heat generated by the dielectric heating mentioned above is εtan
When δ is the eigenvalue of the material and f is the frequency of the microwave, it is proportional to εtanδ·f. In the glass base material described above, the glass rod is made of transparent silica-based glass, the porous glass body is made of a deposit of silica-based glass fine particles,
Contains moisture. Among these, water has the largest tan δ at ε=80, glass rod has ε=2, and glass fine particles of the porous glass body has ε≈1.1.
【０００８】このような事項に基づく本発明方法におい
て、ガラス母材にマイクロ波（１〜１００００ＭＨｚ）
を照射した場合、はじめ、ε値の最も大きい多孔質ガラ
ス体中の水分が発熱し、つぎに、ガラス棒が高温化する
。その結果、水分は内側から外側に向けてよく抜ける。
必要に応じてさらに加熱すると、その後、多孔質ガラス
体のガラス微粒子が発熱して溶融一体化する。すなわち
、多孔質ガラス体は、これの軸心側から外周側に向けて
脱水および／または透明ガラス化されることになる。こ
のように、多孔質ガラス体を軸心側から外周側に向けて
脱水および／または透明ガラス化するとき、該多孔質ガ
ラス体中の水分や気泡が外へ外へと追いやられて、外部
に排除される。したがって、本発明の熱処理方法による
ときは、多孔質ガラス体の内部に気泡を残留させること
なく、これを脱水および／または透明ガラス化すること
ができる。[0008] In the method of the present invention based on the above matters, microwave (1 to 10,000 MHz) is applied to the glass base material.
When irradiated with , the water in the porous glass body with the largest ε value first generates heat, and then the glass rod becomes hot. As a result, water can escape from the inside to the outside. If necessary, the glass particles in the porous glass body generate heat and are melted and integrated. That is, the porous glass body is dehydrated and/or made into transparent vitrification from the axial center side toward the outer peripheral side. In this way, when a porous glass body is dehydrated and/or made into transparent vitrification from the axial center side to the outer circumference side, moisture and air bubbles in the porous glass body are driven outside and released to the outside. be excluded. Therefore, when using the heat treatment method of the present invention, it is possible to dehydrate and/or make the porous glass body transparent without leaving any bubbles inside the porous glass body.
【０００９】[0009]
【実施例】本発明に係る多孔質ガラス体の熱処理方法を
、図示の一実施例に基づいて説明する。図１において、
加熱炉１１は石英製の炉材を含んで構成されており、こ
れにはガス供給系１２、排気系１５、マイクロ波照射系
１６などが備えられている。ガス供給系１２は、フィル
タ１３、サキュレータ１４を有し、図示しないガスボン
ベに接続されている。排気系１５は、図示しない廃棄ガ
ス処理設備に接続されている。マイクロ波照射系１６は
、マイクロ波発生機１７と、パワーモニタ１８と、イン
ピーダンス調整器１９と、放電検出器２０とで構成され
ている。図１において、ガラス母材２３は透明な石英系
ガラス棒２４の外周に石英系の多孔質ガラス体２５が堆
積されたものである。なお、多孔質ガラス体２５は、乾
式ＣＩＰ法（Ｃｏｌｄ Ｉｓｏｓｔａｔｉｃ Ｐｒｅｓ
ｓｉｎｇ） 、ＯＶＤ法などを介してガラス棒２４の外
周に堆積される。EXAMPLE The method of heat treating a porous glass body according to the present invention will be explained based on an example shown in the drawings. In Figure 1,
The heating furnace 11 includes a furnace material made of quartz, and is equipped with a gas supply system 12, an exhaust system 15, a microwave irradiation system 16, and the like. The gas supply system 12 includes a filter 13 and a circulator 14, and is connected to a gas cylinder (not shown). The exhaust system 15 is connected to waste gas processing equipment (not shown). The microwave irradiation system 16 includes a microwave generator 17, a power monitor 18, an impedance adjuster 19, and a discharge detector 20. In FIG. 1, the glass base material 23 is formed by depositing a quartz-based porous glass body 25 on the outer periphery of a transparent quartz-based glass rod 24. As shown in FIG. Note that the porous glass body 25 is formed using a dry CIP method (Cold Isostatic Press).
The glass rod 24 is deposited on the outer periphery of the glass rod 24 using the OVD method or the like.
【００１０】図１に例示した装置を用いて、多孔質ガラ
ス体２５を脱水、透明ガラス化するとき、一例として以
下のようになる。ガラス母材２３の場合、コア用のガラ
ス棒２４が、外径５ｍｍφ、長さ１００ｍｍのＳｉＯ２
−ＧｅＯ２ からなり、クラッド用の多孔質ガラス体
２５が、外径１５ｍｍφのシリカ微粒子（ＳｉＯ２ 微
粒子）の堆積層からなる。なお、多孔質ガラス体２５は
、平均粒径約２μｍのシリカ微粒子が、前記乾式ＣＩＰ
法（成形圧：１０００ｋｇｆ／ｃｍ２ ）を介して成形
されたものである。When the porous glass body 25 is dehydrated and made into transparent vitrification using the apparatus illustrated in FIG. 1, the following is an example. In the case of the glass base material 23, the glass rod 24 for the core is SiO2 with an outer diameter of 5 mmφ and a length of 100 mm.
-GeO2, and the porous glass body 25 for cladding is made of a deposited layer of silica fine particles (SiO2 fine particles) with an outer diameter of 15 mm. In addition, the porous glass body 25 is made of silica fine particles having an average particle size of about 2 μm.
(molding pressure: 1000 kgf/cm2).
【００１１】図１において、上記のガラス母材２３を加
熱炉１１内に置き、ガス供給系１２から加熱炉１１内に
Ｈｅを供給して、炉内をＨｅ雰囲気に保持した後、マイ
クロ波照射系１６よりマイクロ波照射系１６より９１５
ＭＨｚ、２５ｋＷのマイクロ波をガラス母材２３に照射
する。このマイクロ波により、ガラス母材２３を１６５
０℃まで加熱し、この状態を１時間保持して多孔質ガラ
ス体２５を透明ガラス化した。In FIG. 1, the glass base material 23 described above is placed in a heating furnace 11, He is supplied into the heating furnace 11 from the gas supply system 12 to maintain a He atmosphere inside the furnace, and then microwave irradiation is performed. From system 16, from microwave irradiation system 16, 915
The glass base material 23 is irradiated with microwaves of MHz and 25 kW. This microwave heats the glass base material 23 to 165
The porous glass body 25 was heated to 0° C. and maintained in this state for 1 hour to turn the porous glass body 25 into transparent glass.
【００１２】かくて、多孔質ガラス体２５は完全な透明
ガラスとなり、この透明ガラスには気泡の残留がみられ
なかった。多孔質ガラス体２５を透明ガラス化した後の
ガラス母材２３に、さらにクラッド付けを行ない、これ
を加熱線引きしたところ、高品質の通信用光ファイバが
得られた。[0012] Thus, the porous glass body 25 became completely transparent glass, and no air bubbles remained in this transparent glass. A cladding was further applied to the glass base material 23 after the porous glass body 25 had been made into transparent glass, and this was heated and drawn to obtain a high quality communication optical fiber.
【００１３】前述した実施例では、ガラス母材２３を加
熱炉１１内の下部に置いたまま、これを加熱したが、図
１の仮想線で示すように、たとえば、モータのごとき動
力源を含む回転式の昇降機械を介して、ガラス母材２３
を回転させつつ、これを一端から徐々に加熱炉１１内へ
挿入して所定の熱処理を行なってもよい。このようにす
ると、多孔質ガラス体２５に含まれる水分や気泡が下方
から上方へと徐々に追いやられるから、これら水分、気
泡が、ガラス母材の内部により残留しがたくなる。In the above embodiment, the glass base material 23 was heated while being placed in the lower part of the heating furnace 11, but as shown by the imaginary line in FIG. The glass base material 23 is moved through a rotary lifting machine.
While rotating, it may be gradually inserted into the heating furnace 11 from one end to perform a predetermined heat treatment. In this way, the moisture and air bubbles contained in the porous glass body 25 are gradually driven away from the bottom to the top, making it more difficult for these moisture and air bubbles to remain inside the glass base material.
【００１４】本発明の熱処理方法は、脱水のみの熱処理
、透明ガラス化のみの熱処理、脱水と透明ガラス化とを
含む両方の熱処理など、いずれにも適用することができ
る。光ファイバ母材のほか、イメージファイバ母材、ラ
イトガイド母材、ロッドレンズの母材などを作製する際
の多孔質ガラス体の脱水、透明ガラス化にも適用するこ
とができる。The heat treatment method of the present invention can be applied to any heat treatment, such as heat treatment for dehydration only, heat treatment for transparent vitrification only, or both heat treatment including dehydration and transparent vitrification. In addition to optical fiber base materials, it can also be applied to dehydration of porous glass bodies and transparent vitrification when producing image fiber base materials, light guide base materials, rod lens base materials, etc.
【００１５】本発明の熱処理方法は、光ファイバ母材の
ほか、イメージファイバ母材、ライトガイド母材、ロッ
ドレンズの母材などを作製する際の多孔質ガラス体の脱
水、透明ガラス化にも適用することができる。The heat treatment method of the present invention is applicable not only to optical fiber preforms but also to dehydration and transparent vitrification of porous glass bodies when producing image fiber preforms, light guide preforms, rod lens preforms, etc. Can be applied.
【００１６】[0016]
【発明の効果】本発明に係る熱処理方法は、マイクロ波
照射による発熱作用を利用し、多孔質ガラス体をこれの
軸心側から外周側に向けて発熱かつ高温化させるから、
熱処理後のガラス中に水分や気泡が残留しない。[Effects of the Invention] The heat treatment method according to the present invention utilizes the heat generation effect of microwave irradiation to generate heat and raise the temperature of the porous glass body from the axis side to the outer circumference side.
No moisture or air bubbles remain in the glass after heat treatment.
【図１】本発明に係る多孔質ガラス体の熱処理方法を、
これに用いる加熱手段と共に略示した断面図である。FIG. 1 shows a method for heat treatment of a porous glass body according to the present invention,
It is a sectional view schematically showing a heating means used for this.
１１ 加熱炉 １２ ガス供給系 １６ マイクロ波照射系 １７ マイクロ発生機 ２３ ガラス母材 ２４ ガラス棒 ２５ 多孔質ガラス体 11 Heating furnace 12 Gas supply system 16 Microwave irradiation system 17 Micro generator 23 Glass base material 24 Glass rod 25 Porous glass body
Claims (1)
積されたガラス母材において、その多孔質ガラス体を熱
処理するとき、ガラス母材にマイクロ波を照射して、ガ
ラス棒、多孔質ガラス体を発熱させることを特徴とする
多孔質ガラス体の熱処理方法。Claim 1: In a glass base material in which a porous glass body is deposited on the outer periphery of a glass rod, when the porous glass body is heat-treated, the glass base material is irradiated with microwaves, and the glass rod and the porous glass body are heated. A method for heat treatment of a porous glass body characterized by generating heat from the body.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP12671991A JPH04331730A (en) | 1991-04-30 | 1991-04-30 | Method for heat-treating porous glass body |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP12671991A JPH04331730A (en) | 1991-04-30 | 1991-04-30 | Method for heat-treating porous glass body |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH04331730A true JPH04331730A (en) | 1992-11-19 |
Family
ID=14942178
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP12671991A Pending JPH04331730A (en) | 1991-04-30 | 1991-04-30 | Method for heat-treating porous glass body |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH04331730A (en) |
-
1991
- 1991-04-30 JP JP12671991A patent/JPH04331730A/en active Pending
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