JPH07106926B2 - Heating furnace for producing high-purity quartz base material - Google Patents
Heating furnace for producing high-purity quartz base materialInfo
- Publication number
- JPH07106926B2 JPH07106926B2 JP2039726A JP3972690A JPH07106926B2 JP H07106926 B2 JPH07106926 B2 JP H07106926B2 JP 2039726 A JP2039726 A JP 2039726A JP 3972690 A JP3972690 A JP 3972690A JP H07106926 B2 JPH07106926 B2 JP H07106926B2
- Authority
- JP
- Japan
- Prior art keywords
- purity
- base material
- furnace
- core tube
- heating 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 - Fee Related
Links
- 238000010438 heat treatment Methods 0.000 title claims description 37
- 239000000463 material Substances 0.000 title claims description 37
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicon dioxide Inorganic materials O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 title claims description 25
- 239000010453 quartz Substances 0.000 title claims description 23
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 57
- 229910052799 carbon Inorganic materials 0.000 claims description 26
- 239000011248 coating agent Substances 0.000 claims description 18
- 238000000576 coating method Methods 0.000 claims description 18
- 239000000843 powder Substances 0.000 claims description 18
- 229910002804 graphite Inorganic materials 0.000 claims description 16
- 239000010439 graphite Substances 0.000 claims description 16
- 239000005373 porous glass Substances 0.000 claims description 4
- 239000002585 base Substances 0.000 description 28
- 239000013307 optical fiber Substances 0.000 description 18
- 239000007789 gas Substances 0.000 description 10
- 238000005245 sintering Methods 0.000 description 9
- 239000003575 carbonaceous material Substances 0.000 description 8
- 238000000034 method Methods 0.000 description 5
- 230000003647 oxidation Effects 0.000 description 4
- 238000007254 oxidation reaction Methods 0.000 description 4
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 3
- 239000011230 binding agent Substances 0.000 description 3
- 230000000052 comparative effect Effects 0.000 description 3
- 239000011521 glass Substances 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 239000001301 oxygen Substances 0.000 description 3
- 229910052760 oxygen Inorganic materials 0.000 description 3
- 239000002994 raw material Substances 0.000 description 3
- 238000009864 tensile test Methods 0.000 description 3
- YCKRFDGAMUMZLT-UHFFFAOYSA-N Fluorine atom Chemical compound [F] YCKRFDGAMUMZLT-UHFFFAOYSA-N 0.000 description 2
- 238000005352 clarification Methods 0.000 description 2
- 230000018044 dehydration Effects 0.000 description 2
- 238000006297 dehydration reaction Methods 0.000 description 2
- 238000000280 densification Methods 0.000 description 2
- 239000002019 doping agent Substances 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 229910052731 fluorine Inorganic materials 0.000 description 2
- 239000011737 fluorine Substances 0.000 description 2
- 230000005484 gravity Effects 0.000 description 2
- 239000012535 impurity Substances 0.000 description 2
- 239000011261 inert gas Substances 0.000 description 2
- 230000003287 optical effect Effects 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- 230000000149 penetrating effect Effects 0.000 description 2
- 239000002344 surface layer Substances 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- KZBUYRJDOAKODT-UHFFFAOYSA-N Chlorine Chemical compound ClCl KZBUYRJDOAKODT-UHFFFAOYSA-N 0.000 description 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- 238000003763 carbonization Methods 0.000 description 1
- 239000000460 chlorine Substances 0.000 description 1
- 239000000571 coke Substances 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- 238000007380 fibre production Methods 0.000 description 1
- 239000010419 fine particle Substances 0.000 description 1
- 238000010304 firing Methods 0.000 description 1
- 239000000295 fuel oil Substances 0.000 description 1
- 125000002887 hydroxy group Chemical group [H]O* 0.000 description 1
- 238000004898 kneading Methods 0.000 description 1
- 239000010410 layer Substances 0.000 description 1
- 239000007791 liquid phase Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 239000010742 number 1 fuel oil Substances 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 239000002296 pyrolytic carbon Substances 0.000 description 1
Landscapes
- Glass Melting And Manufacturing (AREA)
- Manufacture, Treatment Of Glass Fibers (AREA)
- Ceramic Products (AREA)
Description
【発明の詳細な説明】 ＜産業上の利用分野＞ 本発明は、光ファイバ用母材等を加熱処理（脱水，ドー
パント添加，焼結等）して、光ファイバ製造等に用いる
透明な高純度石英ガラス母材とするための高純度石英母
材製造用加熱炉に関する。DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention is a transparent high-purity material used for optical fiber production, etc., by heat-treating (dehydrating, adding dopant, sintering, etc.) an optical fiber preform. The present invention relates to a heating furnace for producing a high-purity quartz base material for use as a quartz glass base material.
＜従来の技術＞ VAD法またはOVD法を用いて光ファイバ用プリフォームを
製造するために、VAD法またはOVD法で得られたガラス微
粒子積層体を脱水し、稠密・透明化する必要がある。ま
た屈折率調整用のドーパントであるフッ素は、この脱
水、稠密・透明化工程の進行中に添加される。これらの
脱水、稠密・透明化、フッ素添加工程では、炉芯管を持
った加熱炉が使われる。そして、この炉芯管の材質とし
ては、アルミナ（特公昭57−40096号公報および米国特
許第4,338,111号参照）、石英ガラス（特公昭58−58299
号、同58−42136号参照）が使われていた。しかしなが
ら、前者では、不純物（たとえば、アルカリ）が飛散
し、製品が失透しやすいという問題点があり、後者には
不純物（銅および水酸基）が含まれ、製品の光学吸収が
増加すること、さらに耐熱性が不足しているという問題
点があった。<Prior Art> In order to manufacture a preform for an optical fiber by using the VAD method or the OVD method, it is necessary to dehydrate the glass fine particle laminate obtained by the VAD method or the OVD method to make it dense and transparent. Fluorine, which is a dopant for adjusting the refractive index, is added during the process of dehydration, densification and clarification. A heating furnace with a furnace core tube is used in these dehydration, densification / clarification, and fluorine addition steps. As the material of the furnace core tube, alumina (see Japanese Patent Publication No. 57-40096 and US Pat. No. 4,338,111) and quartz glass (Japanese Patent Publication No. 58-58299) are used.
No. 58-42136) was used. However, the former has a problem that impurities (for example, alkali) are scattered and the product is easily devitrified, and the latter contains impurities (copper and hydroxyl group), which increases the optical absorption of the product. There was a problem that heat resistance was insufficient.
これらの問題点を解決するため、本発明者等が検討を行
なった結果、炉芯管の材質としては高純度のカーボンが
最適であるとの結論に達した。この高純度のカーボン炉
芯管を使った場合の加熱炉の様々な形態および使用方法
については特願昭63−34591号（発明の名称：光ファイ
バ用ガラス母材の加熱炉および製法）および国際出願公
開WO88/06145（PCT/JP88/00151）に詳しく記されてい
る。As a result of studies by the present inventors to solve these problems, it was concluded that high-purity carbon is the most suitable material for the furnace core tube. Regarding the various forms and usage of the heating furnace using this high-purity carbon furnace core tube, Japanese Patent Application No. 63-34591 (Title of Invention: Heating furnace and manufacturing method of glass base material for optical fiber) and International The details are described in WO88 / 06145 (PCT / JP88 / 00151).
この高純度のカーボン炉芯管を用いた加熱炉の一例を第
２図に示す。同図に示すように、従来の加熱炉は、中空
炉体５およびそれを貫通する炉芯管３を有して成り、炉
体５の内側に発熱体４が配置されている。炉体５には不
活性ガスの導入口６が設けられ、炉芯管３には雰囲気ガ
ス（例えばCl2,SiF4,He等）の導入口７が設けられてい
る。この加熱炉を使用するには、支持棒２により多孔質
母材１を炉芯管３内で保持しつつ発熱体４で加熱するこ
とにより加熱処理している。An example of a heating furnace using this high-purity carbon furnace core tube is shown in FIG. As shown in the figure, the conventional heating furnace has a hollow furnace body 5 and a furnace core tube 3 penetrating the hollow furnace body 5, and a heating element 4 is arranged inside the furnace body 5. The furnace body 5 is provided with an inlet 6 for an inert gas, and the furnace core tube 3 is provided with an inlet 7 for an atmospheric gas (for example, Cl 2 , SiF 4 , He, etc.). To use this heating furnace, the porous base material 1 is held in the furnace core tube 3 by the support rods 2 and heated by the heating element 4 to perform heat treatment.
尚、炉芯管３はその経済性（即ち、最も消耗し易い中間
部分と相対的に消耗しにくい上下部分とに分割できるよ
うにして、最も消耗し易し中間部分のみ交換できるよう
になっている。）および製造上の理由で上部34、中間部
35および下部36から構成されており、このうちの少なく
とも中間部35は高純度カーボンからできている。この高
純度カーボンの表面にはガス不透過性のSiCコーティン
グ又はカーボンコーティングが施こされている。The furnace core tube 3 is economical (that is, it can be divided into an intermediate part that is most easily consumed and upper and lower parts that are relatively less consumed, so that only the intermediate part that is most easily consumed can be replaced. 34) and the upper part for manufacturing reasons, the middle part
35 and a lower portion 36, at least the middle portion 35 of which is made of high-purity carbon. A gas impermeable SiC coating or carbon coating is applied to the surface of this high-purity carbon.
更に、該炉芯管３の中間部35には第１図に示すようにコ
ーティング保護のための高純度カーボン製の内筒８を挿
入する場合もある。Further, as shown in FIG. 1, an inner cylinder 8 made of high-purity carbon for protecting the coating may be inserted in the intermediate portion 35 of the furnace core tube 3.
＜発明が解決しようとする課題＞ 前述した高純度カーボンを用いた従来の加熱炉は以下の
ような問題がある。<Problems to be Solved by the Invention> The conventional heating furnace using the high-purity carbon described above has the following problems.
高純度多孔質ガラス母材中に物理的あるいは化学的
に微量に含有されている水分や酸素等が加熱処理により
炉芯管内に放出され、高純度カーボン部品が酸化消耗さ
れてしまうという問題がある。There is a problem that moisture and oxygen, which are contained physically or chemically in a trace amount in the high-purity porous glass base material, are released into the furnace core tube by the heat treatment, and the high-purity carbon parts are consumed by oxidation. .
高純度多孔質ガラス母材を支持している支持棒２が
貫通する上蓋37に設けられた貫通部や炉芯管各構成部品
間の隙間より微量の大気が炉芯管３内に混入し、同様に
高純度カーボンが酸化消耗されてしまうという問題があ
る。A small amount of atmospheric air is mixed into the furnace core tube 3 from the penetrating portion provided in the upper lid 37 through which the support rod 2 supporting the high-purity porous glass base material penetrates and the gap between the respective components of the furnace core tube, Similarly, there is a problem that high-purity carbon is consumed by oxidation.
高純度カーボンの表面にガス不透過製のSiC等のコ
ーティングを施しした場合でも、加熱処理中に例えば塩
素ガスを用いた場合、SiCコーティングはがれてしま
い、その後は前述したのと同様な問題がある。Even when a gas impervious coating such as SiC is applied to the surface of high-purity carbon, if chlorine gas is used during the heat treatment, the SiC coating will peel off, and after that, there is the same problem as described above. .
このため、従来では、この酸化消耗量分の厚さを炉芯管
にあらかじめ確保して、加熱処理を行っていたが、50本
程度しか処理できなかった。For this reason, in the past, the thickness corresponding to this oxidative consumption amount was secured in advance in the furnace core tube and heat treatment was performed, but only about 50 pieces could be treated.
しかも、得られた透明化した母材を用いても光ファイバ
を線引きした場合、低強度のものしか得られないという
問題がある。Moreover, even if the obtained transparent base material is used, when an optical fiber is drawn, only a low strength product can be obtained.
これは、通常のカーボン材はコークスを粉砕した微粉に
ピッチ等のバインダを混練した後成形焼成してカーボン
化し、更に黒鉛化したものである。この黒鉛化した状態
ではバインダ部も原料粉も完全にカーボンであるが、酸
化速度の違いにより、バインダ部が先に酸化されてしま
い、この結果、原料粉が脱落しカーボン粉を発生する。
このカーボン粉が、多孔質母材の表面よりやや内部に入
り込むと、透明ガラス化したときに気泡がこの部分で発
生し、光ファイバ化したときに低強度になってしまう。In this case, a normal carbon material is obtained by kneading a fine powder obtained by crushing coke with a binder such as pitch, molding and firing it to carbonize it, and then graphitizing it. In this graphitized state, the binder portion and the raw material powder are completely carbon, but the binder portion is oxidized first due to the difference in the oxidation rate, and as a result, the raw material powder falls off to generate carbon powder.
If this carbon powder enters a little inside the surface of the porous base material, bubbles will be generated at this portion when it is made into transparent glass, and the strength will become low when made into an optical fiber.
本発明は以上述べた事情に鑑み、線引きした光ファイバ
が低強度になることのない高純度石英母材を、長期間に
亙って安定して加熱処理することの出来る高純度石英母
材製造用加熱炉を提供することを目的とする。In view of the above-mentioned circumstances, the present invention provides a high-purity quartz base material capable of stably heat-treating a high-purity quartz base material whose drawn optical fiber does not have low strength over a long period of time. An object of the present invention is to provide a heating furnace.
＜課題を解決するための手段＞ 前記目的を達成するための本発明の第１の発明に係る高
純度石英母材製造用加熱炉の構成は、発熱体を有する中
空の炉体と、該炉体を貫通する高純度カーボン製又はガ
ス不透過性コーティングを施した高純度カーボン製の炉
管缶とを有してなり、高純度石英多孔質ガラス母材を該
炉芯管内で保持して加熱処理する高純度石英母材製造用
加熱炉において、 上記炉芯管を構成する高純度カーボン部品又は該炉芯管
内に存在する高純度カーボン部品のうちのガス不透過性
コーティングを施していない高純度カーボン部品が、メ
ソフェーズ粉を自己焼結した黒鉛製であることを特徴と
し、一方、本発明の第２の発明に係る高純度石英母材製
造用加熱炉の構成は、前記第１の発明の高純度石英母材
製造用加熱炉において、 上記炉芯管を構成する高純度カーボン又は炉芯管内に存
在する高純度カーボン部品のうちのガス不透過性コーテ
ィングを施した高純度カーボン部品の全部又は一部が、
メソフェーズ粉を自己焼結した黒鉛製であることを特徴
とする。<Means for Solving the Problems> A heating furnace for producing a high-purity quartz base material according to the first invention of the present invention for achieving the above-mentioned object is configured as follows: a hollow furnace body having a heating element; It has a furnace tube can made of high-purity carbon that penetrates the body or a high-purity carbon with a gas impermeable coating, and holds and heats the high-purity quartz porous glass preform in the furnace core tube. In a heating furnace for producing a high-purity quartz base material to be processed, a high-purity carbon part constituting the furnace core tube or a high-purity carbon part of the high-purity carbon part present in the furnace core tube, which is not gas-impermeable coated The carbon component is made of graphite obtained by self-sintering mesophase powder, while the structure of the heating furnace for producing a high-purity quartz base material according to the second invention of the present invention is the same as that of the first invention. In a heating furnace for producing high-purity quartz base material All or part of the high-purity carbon parts subjected to gas impermeable coating of the high-purity carbon parts present in high purity carbon or furnace core tube constituting the reactor core tube,
It is characterized in that it is made of graphite by self-sintering mesophase powder.
＜作用＞ 前記構成の高純度石英母材製造用加熱炉を用いて、高純
度石英母材を加熱焼結する場合、メソフェーズ粉を自己
焼結した黒鉛製のカーボン部品としているので、微量の
水分、酸素によって酸化消耗してもほとんどカーボン粉
の発生がなく、多孔質石英母材の内部にカーボン粉が入
り込んで焼結体の気泡の原因となることがない。従っ
て、母材を光ファイバ化しても低強度部の発生がない。<Operation> When the high-purity quartz base material is heated and sintered by using the heating furnace for producing the high-purity quartz base material having the above-mentioned configuration, the mesophase powder is used as a graphite carbon component that is self-sintered, and therefore a small amount of water is included. However, even if oxygen is consumed by oxidation, almost no carbon powder is generated, and the carbon powder does not enter the inside of the porous quartz base material to cause bubbles in the sintered body. Therefore, even if an optical fiber is used as the base material, no low strength portion is generated.
＜実 施 例＞ 以下、本発明に係る高純度石英母材製造用加熱炉の好適
な一実施例を従来技術で説明した第１図を参照して説明
する。<Examples> Hereinafter, a preferred example of the heating furnace for producing a high-purity quartz base material according to the present invention will be described with reference to FIG.
本実施例は第１図に示す加熱炉の内筒８にメソフェーズ
粉を自己焼結した黒鉛製のカーボン材を用いたものであ
る。In this embodiment, a carbon material made of graphite in which mesophase powder is self-sintered is used for the inner cylinder 8 of the heating furnace shown in FIG.
ここで、メソフェーズ粉を自己焼結した黒鉛とは、石炭
又は重質油を熱処理した際、その炭化初期段階の液相に
おいて光学的異方性を示す小球体（この小球体をメソフ
ェーズ小球体という。）が出現している中間層を自己焼
結して得られた黒鉛をいう。このメソフェーズ粉を自己
焼結した黒鉛は、住友金属（株）及び東芝セラミック
（株）より市販されている。Here, graphite obtained by self-sintering mesophase powder refers to small spheres that show optical anisotropy in the liquid phase at the initial stage of carbonization when heat treating coal or heavy oil (these small spheres are called mesophase small spheres). The graphite obtained by self-sintering the intermediate | middle layer which has appeared. Graphite obtained by self-sintering this mesophase powder is commercially available from Sumitomo Metal Co., Ltd. and Toshiba Ceramics Co., Ltd.
このメソフェーズ粉を自己焼結した黒鉛製のカーボン材
を用いることにより、高純度石英母材の加熱処理する場
合に炉芯管内に微量の水分、酸素が混入して酸化消耗し
てもカーボン粉が発生することがない。By using a carbon material made of graphite that self-sinters this mesophase powder, the carbon powder will not be oxidized even if a small amount of water or oxygen is mixed into the furnace core tube during the heat treatment of the high-purity quartz base material and is oxidized. It never happens.
従って、従来のようにカーボン粉が多孔質石英母材の表
面よりやや内側に入り込んで気泡の原因となることがな
く、光ファイバ化した際にも低強度部が発生することも
なくなる。Therefore, unlike the conventional case, the carbon powder does not enter the surface of the porous quartz base material slightly inside to cause bubbles, and the low-strength portion does not occur even when the optical fiber is formed.
更に炉芯管３の中間部35に、上記メソフェーズ粉を自己
焼結した黒鉛製のカーボン材の表面に、ガス不透過性コ
ーティングを施したものを用いるのが望ましい。但し、
炉芯管３の中間部35の基材として、メソフェーズ粉を自
己焼結した黒鉛を用いなくても中間部35のガス不透過性
コーティングが全く消耗しない条件あるいは十分な時間
消耗しない条件で使用する場合であれば問題はない。Further, it is desirable to use, in the intermediate portion 35 of the furnace core tube 3, a carbon material made of graphite, which is obtained by self-sintering the above-mentioned mesophase powder, and has a gas impermeable coating on the surface. However,
Use as a base material of the intermediate portion 35 of the furnace core tube 3 under the condition that the gas-impermeable coating of the intermediate portion 35 is not consumed at all or for a sufficient period of time without using graphite that self-sinters mesophase powder. If so, there is no problem.
また、ガス不透過性コーティングの種類によっては、メ
ソフェーズ粉を自己焼結した黒鉛製のカーボン材の表面
にコーティングした場合、昇降温時に剥離ないしはクラ
ックを起こしやすくなるものがあるので、そのようなお
それのないコーティングに適したコーティング材を用い
るのが望ましい。In addition, depending on the type of gas impermeable coating, when coating the surface of a carbon material made of self-sintered graphite with mesophase powder, there is a possibility that peeling or cracking may occur during temperature increase / decrease. It is desirable to use a coating material that is suitable for coating without coating.
＜試 験 例＞ 以下、本発明の効果を示す試験例を説明する。<Test Example> Hereinafter, a test example showing the effect of the present invention will be described.
第１図に示す高純度石英母材製造用加熱炉を用い、内筒
８として、メソフェーズ粉を自己焼結した黒鉛製のカー
ボン材（カサ比重:1.95,原料最大粒径５μｍ）を用い
た。炉芯管３の中間部35には、通常の等方性黒鉛製のカ
ーボン材を用い、その表面にはガス不透過性熱分解カー
ボンをコーティングした。A heating furnace for producing a high-purity quartz base material shown in FIG. 1 was used, and a carbon material made of graphite (mass specific gravity: 1.95, maximum raw material particle size 5 μm) made by self-sintering mesophase powder was used as the inner cylinder 8. The middle portion 35 of the furnace core tube 3 was made of a normal carbon material made of isotropic graphite, and the surface thereof was coated with gas impermeable pyrolytic carbon.
この加熱炉を用いて、80本の全合成光ファイバ母材の焼
結を行った。Using this heating furnace, 80 all-synthesized optical fiber preforms were sintered.
この焼結中、炉芯管内でのカーボン粉の発生は認められ
ず、後述する比較例で見られた焼結体表層部の気泡の発
生も観察されなかった。During this sintering, the generation of carbon powder was not recognized in the furnace core tube, and the generation of bubbles in the surface layer portion of the sintered body, which was observed in Comparative Examples described later, was not observed.
得られた焼結母材の中から10本目と80本目の母材をそれ
ぞれ線引きして光ファイバ化し、20mのサンプルを各20
本取り、長尺引張試験を行った。The 10th and 80th preforms were drawn from each of the obtained sintered preforms to form optical fibers, and 20m samples of 20
This was taken and a long tensile test was performed.
この結果、引張強度が4.5kg重以下の低強度のサンプル
は10本目及び80本目のいずれの場合も０％であり、全て
良好であった。As a result, the low-strength samples having a tensile strength of 4.5 kgf or less were 0% in both the 10th and 80th samples, which were all good.
また、第２図に示す加熱炉の炉芯管３の中間部35の基材
として、メニフェーズ粉の自己焼結した黒鉛性としその
表面にカーボン製ガス不透過性コーティングを施した場
合でも、得られた焼結母材を光ファイバ化して長尺引張
試験した結果、先の試験例と同様に低強度のサンプルは
０％であり、全て良好であった。In addition, as the base material of the intermediate portion 35 of the furnace core tube 3 of the heating furnace shown in FIG. 2, even when the self-sintered graphitic property of meniphase powder is used and a carbon gas impermeable coating is applied to the surface, it is obtained. As a result of making the obtained sintered base material into an optical fiber and subjecting it to a long tensile test, the low strength sample was 0% as in the previous test example, and all were good.
＜比 較 例＞ 比較例として従来から使用されていま等方性カーボン
（カサ比重:1.77,原料最大粒径60μｍ）を用いて内筒を
構成した加熱炉を用い、試験例と同条件下にて、60本の
全合成光ファイバ母材の焼結を行った。<Comparative example> As a comparative example, a heating furnace having an inner cylinder made of isotropic carbon (rass specific gravity: 1.77, maximum particle size of 60 μm) was used under the same conditions as the test example. As a result, 60 all-synthesized optical fiber preforms were sintered.
得られた焼結母材から10本目と60本目の母材をそれぞれ
線引きして光ファイバ化し、長尺引張試験に同様を行っ
た。The 10th and 60th preforms were drawn from the obtained sintered preforms to form optical fibers, and the same long tensile test was performed.
この結果、10本目の光ファイバでは低強度部が０％であ
ったが、60本目のものでは30％と悪かった。この時炉芯
管内にはカーボン粉が発生しており、焼結体の表層部に
は多数の気泡が存在していた。As a result, the low-strength portion was 0% in the 10th optical fiber, but was 30% in the 60th optical fiber. At this time, carbon powder was generated in the furnace core tube, and many bubbles were present in the surface layer of the sintered body.
＜発明の効果＞ 以上、実施例，試験例と共に述べたように、本発明の高
純度石英母材製造用加熱炉は、メソフェーズ粉を自己焼
結した黒鉛製のカーボン材の発生がなく得られた焼結体
を光ファイバ化した場合、低強度部の発生がなく、光フ
ェイバを長期間安定して使用できる。<Effects of the Invention> As described above with reference to the examples and test examples, the heating furnace for producing a high-purity quartz base material of the present invention can be obtained without generating a carbon material made of graphite in which mesophase powder is self-sintered. When the sintered body is made into an optical fiber, the low-strength portion does not occur, and the optical fiber can be used stably for a long period of time.
第１図，第２図は高純度石英母材製造用加熱炉の概略断
面図である。 図面中、 １は多孔質母材、 ２は支持棒、 ３は炉芯管、 ４は発熱体、 ５は中空炉体、 ６は不活性ガス導入口、 ７は雰囲気ガス導入口、 ８は内筒、 34〜37は炉芯管構成部材である。1 and 2 are schematic sectional views of a heating furnace for producing a high-purity quartz base material. In the drawings, 1 is a porous base material, 2 is a support rod, 3 is a furnace core tube, 4 is a heating element, 5 is a hollow furnace body, 6 is an inert gas inlet, 7 is an atmospheric gas inlet, and 8 is an internal The cylinders 34 to 37 are core tube constituent members.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 斉藤 真秀 神奈川県横浜市栄区田谷町１番地 住友電 気工業株式会社横浜製作所内 (72)発明者 金森 弘雄 神奈川県横浜市栄区田谷町１番地 住友電 気工業株式会社横浜製作所内 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masahide Saito 1 Taya-cho, Sakae-ku, Yokohama-shi, Kanagawa Sumitomo Electric Industries, Ltd. Yokohama Works (72) Inventor Hiroo Kanamori 1 Taya-cho, Sakae-ku, Yokohama, Kanagawa Sumitomo Electric Ki Industry Co., Ltd. Yokohama Works
Claims (2)
通する高純度カーボン製又はガス不透過性コーティング
を施した高純度カーボン製の炉管缶とを有してなり、高
純度石英多孔質ガラス母材を該炉芯管内で保持して加熱
処理する高純度石英母材製造用加熱炉において、 上記炉芯管を構成する高純度カーボン部品又は該炉芯管
内に存在する高純度カーボン部品のうちのガス不透過性
コーティングを施していない高純度カーボン部品が、メ
ソフェーズ粉を自己焼結した黒鉛製であることを特徴と
する高純度石英母材製造用加熱炉。1. A hollow furnace body having a heating element, and a furnace tube can made of high-purity carbon or a high-purity carbon coated with a gas impermeable coating, which penetrates the furnace body. In a heating furnace for producing a high-purity quartz base material, in which a high-purity quartz porous glass base material is held and heat-treated in the furnace core tube, a high-purity carbon component forming the furnace core tube or a high-purity carbon component forming the furnace core tube A heating furnace for producing a high-purity quartz preform, wherein the high-purity carbon component of the high-purity carbon component not coated with a gas impermeable coating is made of graphite in which mesophase powder is self-sintered.
炉において、 上記炉芯管を構成する高純度カーボン又は炉芯管内に存
在する高純度カーボン部品のうちのガス不透過性コーテ
ィングを施した高純度カーボン部品の全部又は一部が、
メソフェーズ粉を自己焼結した黒鉛製であることを特徴
とする高純度石英母材製造用加熱炉。2. A heating furnace for producing a high-purity quartz base material according to claim 1, wherein a gas-impermeable coating of high-purity carbon constituting the furnace core tube or a high-purity carbon component existing in the furnace core tube. All or part of the high-purity carbon parts subjected to
A heating furnace for producing a high-purity quartz base material, which is made of graphite in which mesophase powder is self-sintered.
Priority Applications (8)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2039726A JPH07106926B2 (en) | 1990-02-22 | 1990-02-22 | Heating furnace for producing high-purity quartz base material |
| CA002025880A CA2025880A1 (en) | 1989-09-25 | 1990-09-20 | Furnace for production of optical fiber preform |
| EP90118393A EP0420148B1 (en) | 1989-09-25 | 1990-09-25 | Furnace for production of optical fiber preform |
| AU63134/90A AU637403B2 (en) | 1989-09-25 | 1990-09-25 | Furnace for production of optical fiber preform |
| DE90118393T DE69005246T2 (en) | 1989-09-25 | 1990-09-25 | Oven for the production of an optical fiber preform. |
| EP92112265A EP0509564B1 (en) | 1989-09-25 | 1990-09-25 | Furnace for production of optical fiber preform |
| DE69012350T DE69012350T2 (en) | 1989-09-25 | 1990-09-25 | Oven for the production of preforms for optical fibers. |
| KR9015203A KR930004550B1 (en) | 1989-09-25 | 1990-09-25 | Furnace for production of optical fiber preform |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2039726A JPH07106926B2 (en) | 1990-02-22 | 1990-02-22 | Heating furnace for producing high-purity quartz base material |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH03247530A JPH03247530A (en) | 1991-11-05 |
| JPH07106926B2 true JPH07106926B2 (en) | 1995-11-15 |
Family
ID=12560986
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2039726A Expired - Fee Related JPH07106926B2 (en) | 1989-09-25 | 1990-02-22 | Heating furnace for producing high-purity quartz base material |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH07106926B2 (en) |
-
1990
- 1990-02-22 JP JP2039726A patent/JPH07106926B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH03247530A (en) | 1991-11-05 |
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