JPH07172860A - Production of porous glass preform for optical fiber - Google Patents
Production of porous glass preform for optical fiberInfo
- Publication number
- JPH07172860A JPH07172860A JP5321903A JP32190393A JPH07172860A JP H07172860 A JPH07172860 A JP H07172860A JP 5321903 A JP5321903 A JP 5321903A JP 32190393 A JP32190393 A JP 32190393A JP H07172860 A JPH07172860 A JP H07172860A
- Authority
- JP
- Japan
- Prior art keywords
- porous glass
- gas
- silica fine
- deposition
- raw material
- 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.)
- Granted
Links
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]
- C03B37/01413—Reactant delivery systems
- C03B37/0142—Reactant deposition burners
-
- 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]
- C03B37/01413—Reactant delivery systems
-
- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
- C03B2207/00—Glass deposition burners
- C03B2207/36—Fuel or oxidant details, e.g. flow rate, flow rate ratio, fuel additives
-
- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
- C03B2207/00—Glass deposition burners
- C03B2207/60—Relationship between burner and deposit, e.g. position
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P40/00—Technologies relating to the processing of minerals
- Y02P40/50—Glass production, e.g. reusing waste heat during processing or shaping
- Y02P40/57—Improving the yield, e-g- reduction of reject rates
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Life Sciences & Earth 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)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は光ファイバ用多孔質ガラ
ス母材の製造方法、特には良好な品質の光ファイバ用多
孔質ガラス母材を高い生産性で効率よく製造する光ファ
イバ用多孔質ガラス母材の製造方法に関するものであ
る。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a porous glass preform for an optical fiber, and more particularly to a porous glass preform for an optical fiber which can efficiently produce a porous glass preform for an optical fiber with high productivity. The present invention relates to a method for manufacturing a glass base material.
【０００２】[0002]
【従来の技術】合成石英系の光ファイバ用多孔質ガラス
母材の製造方法としてはＶＡＤ法、ＯＶＤ法、ＭＣＶＤ
法などが知られており、特にＶＡＤ法とＯＶＤ法は生産
性の面でも高水準なものとされている。そして、この２
つの方法ではいずれも原料ガスとしての四塩化けい素(S
iCl4)などを使用し、これを酸水素火炎を形成している
バーナー中に導入し、ここでの火炎加水分解反応などで
シリカ微粒子を発生させ、これを出発材としての合成石
英ガラス棒に吹きつけ出発材上に堆積させ、この成長で
多孔質ガラス母材とする方法で行なわれており、この場
合原料ガスとしては通常 SiCl4が使用されているが、こ
れにはトリクロロシラン(SiHCl3)、メチルトリクロロシ
ラン(CH3SiCl3)などの可燃性ガスを用いられることもあ
り、これらを単独であるいは混合して用いることもあ
る。2. Description of the Related Art VAD method, OVD method, MCVD are used as a method for producing a synthetic quartz-based porous glass preform for optical fibers.
Methods such as the VAD method and the OVD method are particularly high in terms of productivity. And this 2
In both methods, silicon tetrachloride (S
iCl 4 ), etc., is introduced into the burner forming the oxyhydrogen flame, silica fine particles are generated by the flame hydrolysis reaction, etc., and this is used as the starting material for the synthetic quartz glass rod. It is deposited by spraying on a starting material, and this growth is performed to form a porous glass preform.In this case, SiCl 4 is usually used as the source gas, and trichlorosilane (SiHCl 3 ), Methyltrichlorosilane (CH 3 SiCl 3 ), etc. may be used, and these may be used alone or in combination.
【０００３】このＯＶＤ法では原料として SiCl4が用い
られており、この SiCl4の酸水素火炎中での反応は加水
分解が主体となるが、これは反応性が高く、生成したシ
リカ微粒子は集束性が高いので、この場合には図３に示
したように多孔質ガラス母材の外径と堆積速度を両対数
でプロットすると、これがほぼ傾き１の直線に乗ってお
り、原料ガスの供給速度が一定とされることから、シリ
カ微粒子の付着率が多孔質ガラス母材の外径に対し比例
的に変化していることが判る。In this OVD method, SiCl 4 is used as a raw material, and the reaction of this SiCl 4 in an oxyhydrogen flame is mainly hydrolysis, but this is highly reactive and the silica fine particles produced are focused. In this case, when the outer diameter of the porous glass base material and the deposition rate are plotted in logarithmic logarithm as shown in FIG. 3, this is on a straight line with a slope of approximately 1, and the feed rate of the raw material gas is high. From the above, it is understood that the adhesion rate of the silica fine particles changes in proportion to the outer diameter of the porous glass base material.
【０００４】また、このＯＶＤ法では原料ガスとして可
燃性原料であるCH3SiCl3を用いることもあり、この場合
には原料ガスの燃焼反応が中心となり、反応は原料ガス
と酸素との拡散混合律速となるが、このときは SiCl4を
原料とする場合にくらべて反応速度が遅いために、原料
ガスの拡散が大きくなり、シリカ微粒子の拡散も大きく
なって集束性が低下する。このため、 SiCl4と同様にプ
ロットすると、図４に示したように多孔質ガラス母材の
外径の細い部分での付着率が低くなり、傾き１の直線の
下側に来てしまうことが判るが、しかし可燃性ガスを使
用する場合には原料ガスの燃焼による発熱を有効に使用
することが可能となるので、これはＨ2 原単位の向上に
有効な方法とされる。In the OVD method, combustible raw material CH 3 SiCl 3 may be used as the raw material gas. In this case, the combustion reaction of the raw material gas is the center of the reaction, and the reaction is diffusion and mixing of the raw material gas and oxygen. The rate is controlled, but at this time, the reaction rate is slower than when SiCl 4 is used as the raw material, so that the diffusion of the raw material gas is increased and the diffusion of silica fine particles is also increased, which lowers the focusing property. Therefore, if plotted in the same way as for SiCl 4 , the adhesion rate at the portion with a small outer diameter of the porous glass base material becomes low as shown in FIG. 4, and it may come below the straight line of inclination 1. As can be seen, however, when a flammable gas is used, it is possible to effectively use the heat generated by the combustion of the raw material gas, and this is an effective method for improving the H 2 unit consumption.
【０００５】[0005]
【発明が解決しようとする課題】しかし、この場合 SiC
l4のみを原料とすると、シリカ微粒子の集束性が高いた
めに、得られた多孔質ガラス母材の回転ムラ、バーナー
のトラバース速度ムラ、原料の供給速度変動などにより
堆積状態が変化すると、この多孔質ガラス母材表面にス
パイラル状の凹凸が生じ易く、この凹凸が増幅されると
これがやがて多孔質ガラス母材の軸方向全体に拡がり、
コア径の長手方向変動やコアの偏心などの特性不良を発
生し易いという問題が発生する。However, in this case, SiC is used.
If only l 4 is used as the raw material, the fine silica particles have a high focusing property, and therefore, when the deposition state changes due to uneven rotation of the obtained porous glass preform, uneven traverse speed of the burner, fluctuations in the feed rate of the raw material, etc. Spiral unevenness is likely to occur on the surface of the porous glass base material, and when this unevenness is amplified, it eventually spreads over the entire axial direction of the porous glass base material,
There arises a problem that a characteristic defect such as a variation of the core diameter in the longitudinal direction or an eccentricity of the core is likely to occur.
【０００６】また、この原料ガスとして可燃性原料であ
るCH3SiCl3を用いた場合には、生産性向上のために原料
を多量にフィードしても、生成するシリカ微粒子の拡散
が大きいために多孔質ガラス母材の表面での凹凸の発生
は見られないけれども、この場合には多孔質ガラス母材
の細いときにはシリカ微粒子の付着率が低くなり、生産
性が低下するという問題点がある。Further, when CH 3 SiCl 3 which is a flammable raw material is used as the raw material gas, even if a large amount of the raw material is fed in order to improve the productivity, the generated silica fine particles are largely diffused. Although no unevenness is observed on the surface of the porous glass base material, in this case, when the porous glass base material is thin, the adhesion rate of silica fine particles is low, and there is a problem that productivity is reduced.
【０００７】[0007]
【課題を解決するための手段】本発明はこのような不
利、問題点を解決した光ファイバ用多孔質ガラス母材の
製造方法に関するものであり、これは石英ガラス部材を
出発材とし、酸水素火炎中に不燃性原料である四塩化け
い素と可燃性原料ガスを供給し、これら原料ガスの反応
により生成したシリカ微粒子を該出発材の外周に堆積し
て多孔質ガラス母材を製造する方法において、この酸水
素火炎中に供給する原料ガスの濃度を、シリカ微粒子の
堆積の前半で多孔質ガラス母材の外径が細いときには不
燃性ガスの濃度を高めるようにし、シリカ微粒子の堆積
の後半で多孔質母材の外径が太いときには可燃性ガスの
濃度を高めるようにしてなることを特徴とするものであ
る。SUMMARY OF THE INVENTION The present invention relates to a method for producing a porous glass preform for optical fibers, which solves the above disadvantages and problems, and which uses a quartz glass member as a starting material and oxyhydrogen. A method for producing a porous glass preform by supplying silicon tetrachloride, which is an incombustible raw material, and a combustible raw material gas into a flame, and depositing silica fine particles produced by the reaction of these raw material gases on the outer periphery of the starting material. In this case, the concentration of the raw material gas supplied into the oxyhydrogen flame is set so as to increase the concentration of the noncombustible gas when the outer diameter of the porous glass base material is small in the first half of the deposition of silica fine particles, and the second half of the deposition of silica fine particles. When the outer diameter of the porous base material is large, the concentration of the combustible gas is increased.
【０００８】すなわち、本発明者らは光ファイバ用多孔
質ガラス母材の効率的な製造方法を開発すべく種々検討
した結果、これについては酸水素火炎中に原料ガスを供
給し、この原料ガスの反応により生成するシリカ微粒子
を石英ガラス棒に堆積して多孔質ガラス母材を製造する
方法において、この原料ガスとして四塩化けい素などの
不燃性原料ガスとトリクロロシラン、メチルトリクロロ
シランなどの可燃性原料ガスを併用すると、それぞれの
原料ガスの欠点が補われ、これらのメリットが生かせる
ことを見出し、シリカ微粒子の堆積の前半で未だ多孔質
ガラス母材の外径が細いときには SiCl4の濃度を高くす
ると、この SiCl4から発生したシリカ微粒子が集束性の
高いものであるために堆積速度が高水準となり堆積が促
進されるし、シリカ微粒子の堆積の後半で多孔質ガラス
母材の外径が太くなっているときにはCH3SiCl3などの可
燃性原料ガスの濃度を高くすると、ここに発生したシリ
カ微粒子の拡散が大きくなるので多孔質ガラス母材表面
に凹凸が生ずることがなくなり、結果としてコア径の長
手方向安定性、コア偏芯率の極めて良好な光ファイバ用
石英ガラス母材を得ることができ、さらには可燃性の発
熱によりＨ2 流量を減少させることができるので生産性
をよくし、コストを低下させることもできることを確認
して本発明を完成させた。以下にこれをさらに詳述す
る。That is, the present inventors have conducted various studies to develop an efficient method for producing a porous glass preform for optical fibers. As a result, the raw material gas is supplied into an oxyhydrogen flame, and the raw material gas is supplied. In the method of manufacturing porous glass base material by depositing silica fine particles generated by the reaction of the above, on a quartz glass rod, as the raw material gas, noncombustible raw material gas such as silicon tetrachloride and combustible materials such as trichlorosilane and methyltrichlorosilane are used. It was found that the disadvantages of each raw material gas can be compensated for by using the same raw material gas together, and these merits can be utilized.When the outer diameter of the porous glass base material is still small in the first half of the deposition of silica fine particles, the concentration of SiCl 4 can be increased. the higher, to the SiCl 4 deposition rate for the silica fine particles is as high the converging generated from becomes high deposition is promoted, silica The higher the concentration of combustible material gas, such as CH 3 SiCl 3 when the outer diameter of the porous glass base material in the latter half of the deposition of particles is thickened, the diffusion becomes large silica particles occurring here porous No irregularities occur on the surface of the glass base material, and as a result, it is possible to obtain a quartz glass base material for optical fibers with excellent stability of the core diameter in the longitudinal direction and a very good eccentricity of the core. The present invention has been completed by confirming that the H 2 flow rate can be reduced to improve the productivity and also reduce the cost. This will be described in more detail below.
【０００９】[0009]
【作用】本発明は光ファイバ用多孔質ガラス母材の製造
方法に関するものであり、これは石英ガラス部材を出発
材とし、酸水素火炎中に不燃性原料ガスとしての四塩化
けい素と可燃性原料とを供給し、これらの反応により得
られたシリカ微粒子を出発材の外周上に堆積して多孔質
ガラス母材を製造する方法において、シリカ微粒子の堆
積の前半で多孔質ガラス母材の外径が細いときには不燃
性のガスの濃度を高めるようにし、シリカ微粒子の堆積
の後半で多孔質ガラス母材の外径が太くなっているとき
には可燃性ガスの濃度を高くするようにしてなることを
特徴とするものであるが、これによればシリカ微粒子の
堆積を堆積前半では高い堆積速度で行なうことができ、
堆積後半ではシリカ微粒子の拡散が大きくなるので表面
に凹凸のない多孔質ガラス母材をコア径の長手方向安定
性、コア偏芯率のよいものとして得ることができるとい
う有利性が与えられる。The present invention relates to a method for producing a porous glass preform for optical fibers, which uses a quartz glass member as a starting material, and silicon tetrachloride as a nonflammable source gas in an oxyhydrogen flame and flammability. In the method of producing a porous glass preform by supplying the raw materials and depositing silica fine particles obtained by these reactions on the outer periphery of the starting material, in the first half of the deposition of the silica fine particles, When the diameter is small, the concentration of non-combustible gas should be increased, and when the outer diameter of the porous glass base material is large in the latter half of the deposition of silica fine particles, the concentration of combustible gas should be increased. According to this, it is possible to deposit silica fine particles at a high deposition rate in the first half of the deposition.
In the latter half of the deposition, the diffusion of the silica fine particles becomes large, so that there is an advantage that a porous glass base material having no irregularities on the surface can be obtained as one having a good stability of the core diameter in the longitudinal direction and a good core eccentricity.
【００１０】本発明による光ファイバ用多孔質ガラス母
材の製造は、ガス状のけい素化合物の火炎加水分解、燃
焼などで発生したシリカ微粒子を石英ガラス棒などに堆
積するという公知の方法で行なわれるが、本発明ではこ
の原料ガスが四塩化けい素などの不燃性ガスとトリクロ
ロシラン、メチルトリクロロシラン、ジメチルジクロロ
シランなどの可燃性ガスの混合物からなるものとされ
る。本発明はこのように原料ガスとして不燃性ガスと可
燃性ガスが使用されるのであるが、本発明によれば不燃
性ガスと可燃性ガスの有するそれぞれの欠点が補われる
ので、目的とする光ファイバ用多孔質ガラス母材は品質
性のよいものを生産性よく製造することができるが、こ
の不燃性ガスと可燃性ガスは別々に気化させてからこれ
を混合しバーナーに供給される。The porous glass preform for optical fibers according to the present invention is manufactured by a known method of depositing silica fine particles generated by flame hydrolysis, combustion, etc. of a gaseous silicon compound on a quartz glass rod or the like. However, in the present invention, the raw material gas is composed of a mixture of a nonflammable gas such as silicon tetrachloride and a flammable gas such as trichlorosilane, methyltrichlorosilane and dimethyldichlorosilane. In the present invention, the non-combustible gas and the combustible gas are used as the raw material gas in this way, but since the respective disadvantages of the non-combustible gas and the combustible gas are compensated for according to the present invention, the target light The porous glass preform for fibers can be produced with good quality and with good productivity. However, the incombustible gas and the combustible gas are vaporized separately, and then mixed and supplied to the burner.
【００１１】本発明による光ファイバ用多孔質ガラス母
材の製造は例えばこの製造装置の縦断面図を示した図１
の装置で行なわれる。すなわち、本発明で使用される四
塩化けい素(SiCl4) などの不燃性化合物と、トリクロロ
シラン(SiHCl3)、メチルトリクロロシラン(CH3SiCl3)、
ジメチルジクロロシラン[(CH3)2SiCl2] などの可燃性ガ
スは図１の不燃性原料バブラ１と可燃性原料バブラ２に
それぞれ貯えられており、これらは質量流量計（図中に
はＭＦＣと表示されている）を経由してここに導入され
るキャリヤガスのバブリングによってガス化され、酸水
素火炎バーナー３に火炎形成用のＯ2 、Ｈ2 と共に供給
される。The production of the porous glass preform for optical fibers according to the present invention is shown in FIG. 1 which is a longitudinal sectional view of this production apparatus, for example.
It is performed by the device. That is, a non-combustible compound such as silicon tetrachloride (SiCl 4 ) used in the present invention, trichlorosilane (SiHCl 3 ), methyltrichlorosilane (CH 3 SiCl 3 ),
Combustible gases such as dimethyldichlorosilane [(CH 3 ) 2 SiCl 2 ] are stored in the noncombustible raw material bubbler 1 and the combustible raw material bubbler 2 in FIG. 1, respectively, and these are stored in the mass flowmeter (MFC in the figure). (Denoted as) and is gasified by bubbling of a carrier gas introduced into the oxyhydrogen flame burner 3 together with O 2 and H 2 for flame formation.
【００１２】この酸水素火炎バーナーにおいて不燃性ガ
スは火炎加水分解によりシリカ微粉末となり、可燃性ガ
スはその燃焼によりシリカ微粉末となるので、このシリ
カ微粉末を出発材としての石英ガラス棒４に堆積させれ
ば、ここに多孔質ガラス母材５を得ることができるので
あるが、本発明ではこのシリカ微粒子の堆積の前半で多
孔質ガラス母材５の外径が未だ細いときには不燃性ガス
の濃度を高くしてシリカ微粒子の堆積速度を高くし、シ
リカ微粒子の堆積の後半ですでに多孔質ガラス母材５の
外径が太くなっているときには可燃性ガスの濃度を高く
してシリカ微粒子の拡散を大きくし、多孔質ガラス母材
の表面に凹凸が生じないようにされる。In this oxyhydrogen flame burner, the incombustible gas becomes a fine silica powder by flame hydrolysis, and the combustible gas becomes a fine silica powder by its combustion. Therefore, the fine silica powder is applied to the quartz glass rod 4 as a starting material. The porous glass base material 5 can be obtained here by depositing it. However, in the present invention, when the outer diameter of the porous glass base material 5 is still small in the first half of the deposition of the silica fine particles, a non-combustible gas is generated. The concentration is increased to increase the deposition rate of the silica fine particles, and if the outer diameter of the porous glass base material 5 is already thick in the latter half of the deposition of the silica fine particles, the concentration of the combustible gas is increased to increase the silica fine particles. The diffusion is increased so that the surface of the porous glass base material is not uneven.
【００１３】なお、本発明ではこのシリカ微粒子を発生
させる原料ガスとして上記したように不燃性原料ガスと
可燃性原料の混合物が使用されるのであるが、これにつ
いては図２（ａ）に示したようにシリカ微粒子の堆積前
半で多孔質ガラス母材の外径が未だ細いときには原料ガ
スとして SiCl4などの不燃性ガスを主体とするものと
し、この多孔質ガラス母材の外径が太くなるにしたがっ
て可燃性ガスの比率を高めてこれらを略々等量宛とし、
堆積終了時にも可燃性ガスが主体となるようにすること
がよい。In the present invention, a mixture of a non-combustible raw material gas and a combustible raw material is used as the raw material gas for generating the silica fine particles, as shown in FIG. 2 (a). As described above, when the outer diameter of the porous glass base material is still thin in the first half of the deposition of the silica particles, the main gas is mainly non-combustible gas such as SiCl 4, and the outer diameter of this porous glass base material becomes large. Therefore, increase the ratio of combustible gas and direct these to approximately equal amounts,
It is preferable that the combustible gas be the main component even after the deposition is completed.
【００１４】しかし、これはまた図２（ｂ）に示したよ
うにシリカ微粒子の堆積開始時には原料ガスを不燃性ガ
スのみなるものとし、多孔質ガラス母材の外径が太くな
る途中から可燃性ガスの供給を開始して逐次その供給速
度を増大させると共に、不燃性ガスの供給速度を低下さ
せ、堆積終了時には可燃性ガスのみからなるようにして
もよいし、さらには図２（ｃ）に示したようにシリカ微
粒子の堆積開始から多孔質ガラス母材の外径がある程度
に太るまでは原料ガスを不燃性ガスのみからなるものと
し、それ以降は原料ガスを可燃性ガスのみからなるもの
に切換えるようにしてもよい。However, as shown in FIG. 2 (b), the raw material gas is composed of only noncombustible gas at the start of deposition of silica fine particles, and the combustibility is increased from the middle of the outer diameter of the porous glass preform. The supply of gas may be started and the supply speed thereof may be increased successively, and the supply speed of non-combustible gas may be decreased so that only the combustible gas is formed at the end of the deposition. Further, as shown in FIG. As shown, the raw material gas consists only of non-combustible gas from the start of deposition of silica fine particles until the outer diameter of the porous glass base material becomes thick to some extent, and thereafter the raw material gas consists of only flammable gas. You may make it switch.
【００１５】[0015]
【実施例】つぎに本発明の実施例をあげる。 実施例 図１に示した多孔質ガラス母材製造装置を用いてＯＶＤ
法により多孔質ガラス母材の製造を行なったが、不燃性
原料としての SiCl4と可燃性原料としてのCH3SiCl3をそ
れぞれバブラ１、２に入れ、キャリヤガスとして SiCl4
にはＯ2 を、CH3SiCl3にはアルゴンガスを使用し、この
バブリングで得たそれぞれのガスを混合してＯ2 ガスお
よびＨ2 ガスと共に酸水素火炎バーナー３に供給した。EXAMPLES Next, examples of the present invention will be given. Example OVD was performed using the porous glass base material manufacturing apparatus shown in FIG.
A porous glass base material was manufactured by the method, but SiCl 4 as a non-combustible raw material and CH 3 SiCl 3 as a combustible raw material were put into bubblers 1 and 2, respectively, and SiCl 4 was used as a carrier gas.
O 2 and CH 3 SiCl 3 using argon gas, the respective gases obtained by the bubbling were mixed and supplied to the oxyhydrogen flame burner 3 together with the O 2 gas and the H 2 gas.
【００１６】この酸水素火炎バーナーで発生したシリカ
微粒子を石英ガラス棒４に堆積して多孔質ガラス母材５
を製造したが、この原料供給パターンは図２（ｂ）に示
したようにシリカ微粒子の堆積開始時は不燃性ガスのみ
とし、多孔質ガラス母材の外径がある程度太くなったと
きに可燃性ガスの供給を開始し、この可燃性ガスの供給
速度を逐次増大させると共に、不燃性ガスの供給速度を
逐次低下させ、堆積の後段では可燃性ガスのみとすると
いう方法で多孔質ガラス母材の製造を行なった。Silica fine particles generated by this oxyhydrogen flame burner are deposited on a quartz glass rod 4 to form a porous glass base material 5.
As shown in FIG. 2 (b), the raw material supply pattern is made of only noncombustible gas at the start of deposition of silica fine particles, and is combustible when the outer diameter of the porous glass base material becomes thick to some extent. The supply of gas is started, the supply rate of this combustible gas is sequentially increased, the supply rate of non-combustible gas is gradually decreased, and only the combustible gas is used in the latter stage of the deposition. Manufacturing was performed.
【００１７】この場合、堆積速度を多孔質ガラス母材の
外径に対し両対数をプロットしたところ、その外径の細
い領域から太い領域にまで図３に示したように傾き１の
直線にのっていて、これには堆積速度の低下はみられ
ず、外径が 300mmφで長さが1,000mmLである光ファイバ
多孔質ガラス母材を得ることができ、このものを脱水透
明ガラス化して得た光ファイバ用石英ガラス体は外観が
滑らかで表面に凹凸は全く見られず、これはその屈折率
分布を測定したところ、コア径の変動、コア偏芯率も極
めて良好なものであったし、この場合には可燃性原料ガ
スが有効に使用されたために SiCl4のみを用いた場合に
くらべてＨ2 原単位を約20％向上させることができた。In this case, when the logarithm of the deposition rate was plotted with respect to the outer diameter of the porous glass base material, the straight line with a slope of 1 as shown in FIG. However, there was no decrease in the deposition rate, and an optical fiber porous glass preform with an outer diameter of 300 mmφ and a length of 1,000 mmL could be obtained. The quartz glass body for optical fibers had a smooth appearance and no irregularities were found on the surface. The measurement of the refractive index distribution showed that the fluctuation of the core diameter and the eccentricity of the core were also very good. In this case, since the combustible raw material gas was effectively used, the H 2 unit consumption could be improved by about 20% as compared with the case where only SiCl 4 was used.
【００１８】[0018]
【発明の効果】本発明は光ファイバ用多孔質ガラス母材
の製造方法に関するものであり、これは前記したよう
に、原料ガスとして四塩化けい素などの不燃性原料ガス
と可燃性原料ガスを使用し、ＶＡＤ法などの公知の方法
で光ファイバ用多孔質ガラス母材を製造する方法におい
て、この酸水素火炎中に供給する原料ガスの濃度を、シ
リカ微粒子の堆積の前半で多孔質ガラス母材の外径が細
いときには不燃性ガスの濃度を高めるようにし、シリカ
微粒子の堆積の後半で多孔質ガラス母材の外径が太いと
きには可燃性ガスの濃度を高めるようにしてなることを
特徴とするものであるが、これによれば全工程を通して
堆積速度の低下がみられず、目的とする多孔質ガラス母
材を表面に凹凸のないものとして得ることができ、これ
を透明ガラス化して得られる光ファイバ用石英ガラスを
コア径の長手方向安定性、コア偏芯率の極めて良好なも
のとすることができるという有利性が与えられる。Industrial Applicability The present invention relates to a method for producing a porous glass preform for optical fibers, which, as described above, uses a non-combustible source gas such as silicon tetrachloride and a combustible source gas as source gases. In the method for producing a porous glass preform for optical fibers by a known method such as the VAD method, the concentration of the raw material gas supplied into the oxyhydrogen flame is set in the first half of the deposition of silica fine particles. When the outer diameter of the material is small, the concentration of the incombustible gas is increased, and when the outer diameter of the porous glass base material is large in the latter half of the deposition of the silica fine particles, the concentration of the combustible gas is increased. However, according to this, the deposition rate does not decrease throughout the process, and the target porous glass base material can be obtained without unevenness on the surface. Longitudinal stability of the core diameter quartz glass for an optical fiber which is, advantage is given that can be made very good core eccentricity ratio.
【図１】本発明の光ファイバ用多孔質ガラス母材を製造
する多孔質ガラス母材製造装置の縦断面図を例示したも
のである。FIG. 1 is a view exemplifying a vertical cross-sectional view of a porous glass base material manufacturing apparatus for manufacturing a porous glass base material for an optical fiber of the present invention.
【図２】（ａ）、（ｂ）、（ｃ）は本発明における原料
供給パターンを変えたときの多孔質ガラス母材の外径と
原料供給速度との３種類の関係図を示したものである。2 (a), (b), and (c) show three types of relationship diagrams between the outer diameter of the porous glass base material and the raw material supply rate when the raw material supply pattern in the present invention is changed. Is.
【図３】原料ガスを SiCl4とした公知の方法における多
孔質ガラス母材の外径と堆積速度との両対数プロットに
よる関係図を示したものである。FIG. 3 is a diagram showing the relationship between the outer diameter of a porous glass preform and the deposition rate by a logarithmic log plot in a known method using SiCl 4 as a raw material gas.
【図４】原料ガスを可燃性ガスとした公知の方法におけ
る多孔質ガラス母材の外径と堆積速度との両対数プロッ
トによる関係図を示したものである。FIG. 4 is a diagram showing a relationship diagram by a logarithmic plot of the outer diameter of the porous glass base material and the deposition rate in a known method in which the raw material gas is a combustible gas.
１ 不燃性原料用バブラ ２ 可燃性原料用バブラ ３ 酸水素火炎バーナー ４ 石英ガラス棒 ５ 多孔質ガラス母材 1 Bubbler for non-combustible raw material 2 Bubbler for combustible raw material 3 Oxygen hydrogen flame burner 4 Quartz glass rod 5 Porous glass base material
Claims (3)
炎中に不燃性原料ガスである四塩化けい素と可燃性原料
ガスを供給し、これら原料ガスの反応で発生したシリカ
微粒子を該出発材の外周に堆積して多孔質ガラス母材を
製造する方法において、この酸水素火炎中に供給する原
料ガスの濃度を、シリカ微粒子の堆積の前半で多孔質ガ
ラス母材の外径が細いときには不燃性ガスの濃度を高め
るようにし、シリカ微粒子の堆積の後半で多孔質ガラス
母材の外径が太いときには可燃性ガスの濃度を高めるよ
うにしてなることを特徴とする光ファイバ用多孔質ガラ
ス母材の製造方法。1. A quartz glass member is used as a starting material, silicon tetrachloride which is an incombustible source gas and a combustible source gas are supplied into an oxyhydrogen flame, and silica fine particles generated by a reaction of these source gases are used as the starting material. In the method of producing a porous glass preform by depositing on the outer periphery of the material, the concentration of the raw material gas supplied into the oxyhydrogen flame is set to be small when the outer diameter of the porous glass preform is small in the first half of the deposition of silica fine particles. Porous glass for optical fiber characterized by increasing the concentration of noncombustible gas and increasing the concentration of combustible gas when the outer diameter of the porous glass base material is large in the latter half of the deposition of silica fine particles. Base material manufacturing method.
微粒子の堆積開始時には不燃性原料ガスのみとし、シリ
カ微粒子の堆積終了時には可燃性原料ガスのみとする請
求項１に記載した光ファイバ用多孔質ガラス母材の製造
方法。2. The optical fiber according to claim 1, wherein the gas supplied into the oxyhydrogen flame is only a non-combustible raw material gas at the start of deposition of silica fine particles and only a combustible raw material gas at the end of deposition of silica fine particles. A method for manufacturing a porous glass base material.
Cl3)、メチルトリクロロシラン(CH3SiCl3)、ジメチルジ
クロロシラン[(CH3)2SiCl2] である請求項１に記載した
光ファイバ用多孔質ガラス母材の製造方法。3. The flammable source gas is trichlorosilane (SiH
Cl 3 ), methyltrichlorosilane (CH 3 SiCl 3 ), dimethyldichlorosilane [(CH 3 ) 2 SiCl 2 ], and the method for producing a porous glass preform for an optical fiber according to claim 1.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP05321903A JP3131087B2 (en) | 1993-12-21 | 1993-12-21 | Method for producing porous glass preform for optical fiber |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP05321903A JP3131087B2 (en) | 1993-12-21 | 1993-12-21 | Method for producing porous glass preform for optical fiber |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH07172860A true JPH07172860A (en) | 1995-07-11 |
| JP3131087B2 JP3131087B2 (en) | 2001-01-31 |
Family
ID=18137697
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP05321903A Expired - Fee Related JP3131087B2 (en) | 1993-12-21 | 1993-12-21 | Method for producing porous glass preform for optical fiber |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3131087B2 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0976690A2 (en) * | 1998-07-29 | 2000-02-02 | Shin-Etsu Chemical Co., Ltd. | Porous or vitrified preforms for optical fibres and methods for producing them |
| WO2005005332A1 (en) * | 2003-07-11 | 2005-01-20 | Lg Cable Ltd. | Outside vapor deposition apparatus for manufacturing optical fiber preform and method for manufacturing optical fiber preform using the same |
-
1993
- 1993-12-21 JP JP05321903A patent/JP3131087B2/en not_active Expired - Fee Related
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0976690A2 (en) * | 1998-07-29 | 2000-02-02 | Shin-Etsu Chemical Co., Ltd. | Porous or vitrified preforms for optical fibres and methods for producing them |
| EP0976690A3 (en) * | 1998-07-29 | 2000-12-06 | Shin-Etsu Chemical Co., Ltd. | Porous or vitrified preforms for optical fibres and methods for producing them |
| US6306500B1 (en) | 1998-07-29 | 2001-10-23 | Shin-Etsu Chemical Co., Ltd. | Porous optical fiber base materials, optical fiber base materials and methods for producing them |
| WO2005005332A1 (en) * | 2003-07-11 | 2005-01-20 | Lg Cable Ltd. | Outside vapor deposition apparatus for manufacturing optical fiber preform and method for manufacturing optical fiber preform using the same |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3131087B2 (en) | 2001-01-31 |
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