JPS63112435A - Production of quartz glass - Google Patents

Abstract

PURPOSE:To obtain a quartz glass without the generation of cracks, by producing a dry gel from alkyl silicate by sol-gel process, preliminarily heating the gel in a gas flow system while introducing dry air and heat-treating the gel at a high temperature. CONSTITUTION:A dry gel used as a glass precursor is produced by sol-gel process using alkyl silicate as a raw material. The dry gel is heated up to 1,000 deg.C in a gas flow system while introducing dry air into the system and maintained at the temperature. Thereafter, the gel is heated to a higher temperature and maintained at the temperature for a specific period to obtain the objective quartz glass. Ineffective components such as physically adsorbed water, carbon residue, etc., can be forcibly discharged from the system in the course of heating the gel to 1,000 deg.C under the introduction of dry air and, accordingly, the shrinkage difference between the inner part and the surface of the dry gel can be decreased to enable the suppression of the phenomena such as breakage, cracking etc.

Description

【発明の詳細な説明】 〔産業上の利用分野〕 本発明は、ゾル−ゲル法による石英ガラスの製造方法に
関する。DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for producing quartz glass by a sol-gel method.

〔従来の技術〕[Conventional technology]

ゾル−ゲル法によシ得られたドライゲルを、８００〜１
１００℃まで、ゆっくりと加熱すると、水とアルコール
は取り除かれ、シラノール基はシロキチン結合に変わシ
、シリカゲル微粒子どうしを緻密に接着、結合させ、細
孔のないシリカガラス体を得た。The dry gel obtained by the sol-gel method was
When heated slowly to 100° C., water and alcohol were removed, the silanol groups were converted to silochitin bonds, and the silica gel particles were tightly adhered and bonded to each other, resulting in a pore-free silica glass body.

〔発明が解決しようとする問題点〕[Problem that the invention seeks to solve]

しかし、ドライゲルに含まれる物理吸着水あるいは炭素
残基等、ガラスに対する非有効成分が、密閉系内での焼
結の際、系内に充満し、この処理段階でバルクが割れた
シ、クラックが入る、等所期形状のガラスあるいは、ガ
ラス前駆体を調造することが困難であった。However, during sintering in a closed system, components that are not effective for glass, such as physically adsorbed water or carbon residues contained in the dry gel, fill the system, resulting in bulk breakage and cracks during this processing step. It has been difficult to prepare glasses or glass precursors with a uniform shape.

そこで、本発明は、このような問題点を解決するもので
、その目的とするところは、ガラスあるいは、ガラス前
駆体としてのドライゲルの熱処理に於ける削れ等を著る
しく減少させ、高歩留りで提供するところにある。Therefore, the present invention is intended to solve these problems, and its purpose is to significantly reduce the occurrence of scraping during heat treatment of glass or dry gel as a glass precursor, and to achieve a high yield. It's there to provide.

〔問題点を解決するための手段〕[Means for solving problems]

少なくとも、アルキルシリケートを原料とし、ゾル−ゲ
ル法で作成した、ガラスあるいは、ガラス前駆体を加熱
し、一定時間保持する石英ガラス合成において、そのガ
ラス前駆体としてのドライゲルを、気体フロー系内でド
ライエアーを流入しながら、１０００℃まで昇温、保持
すること？特徴とする。これによシ、１０００℃以上の
熱処理をする前に割れ、クランク等の現象は無くなシ、
さらｖｃ　ｙ：ｔｎ　Ｐ％し、一定時間保持して得られ
るガラスも、所期の形状を保つことができる。At least, in silica glass synthesis in which glass or a glass precursor made from alkyl silicate by the sol-gel method is heated and held for a certain period of time, the dry gel as the glass precursor is dried in a gas flow system. Raise the temperature to 1000℃ and maintain it while introducing air? Features. As a result, phenomena such as cracking and cranking will be eliminated before heat treatment at 1000°C or higher.
Glass obtained by further increasing vc y:tn P% and holding it for a certain period of time can also maintain the desired shape.

〔作用〕[Effect]

ガラス前駆体としてのドライゲルには、依然として、物
理吸着水、炭素残基が多分に含まれておわ、５００℃〜
９００℃まで残存する。さらて、ドライゲルは、９００
℃程度まで加熱処理をした後でも吸湿性に対して可逆的
である。単に密閉系でクリーンな雰囲気にし、１０００
℃まで加熱処理をした場合、２００℃付近での吸着水の
離脱、３００〜４００℃付近での炭素残基あるいは塩の
分解に伴ない、ドライゲルの表面付近は、こういった非
有効成分が充満していると言える。この時、ドライゲル
は、加熱に伴ない収縮が起こっており、表面と内部とで
は、収縮機構に差が生じておシ、この収縮差が原因とな
って割れ、クランク等の現象が起こる。The dry gel as a glass precursor still contains a large amount of physically adsorbed water and carbon residues, and is heated at temperatures of 500°C to
Remains up to 900°C. Furthermore, dry gel is 900
Hygroscopicity is reversible even after heat treatment to about ℃. Simply create a clean atmosphere in a closed system, and
When heat-treated to ℃, the surface of the dry gel is filled with these ineffective components due to the separation of adsorbed water at around 200℃ and the decomposition of carbon residues or salts at around 300 to 400℃. I can say that I am doing it. At this time, the dry gel is shrinking due to heating, and there is a difference in the shrinkage mechanism between the surface and the inside, and this difference in shrinkage causes phenomena such as cracking and cranking.

これに対して、いわゆる気体フロー系内部にドライエア
ーをフローさせることによって、これらの充満した様々
の非有効成分を、強制的に系外へ排除することによって
、ドライゲル内部と表面との収縮差を少なくシ、割れ、
クランク等の現象を著るしく減少させることができる。On the other hand, by flowing dry air inside the so-called gas flow system, these various inactive components filled with the system are forcibly removed from the system, thereby reducing the shrinkage difference between the inside and surface of the dry gel. Fewer scratches, cracks,
Phenomena such as cranking can be significantly reduced.

なお、フローするガスについては、塩化カルシウム、シ
リカゲル等を通過させて水分は極力避けるのが望ましい
。As for the flowing gas, it is desirable to allow it to pass through calcium chloride, silica gel, etc. and avoid moisture as much as possible.

また、高価である高純度の不活性ガス等を使用する必要
はない。Furthermore, there is no need to use expensive high-purity inert gas or the like.

〔実施例〕〔Example〕

エチルシリケー）８ｔとα００５規定塩酸水溶液／ｈ５
ｔを混合撹拌し、無色透明な均一水溶液な得た。ethyl silicate) 8t and α005 normal hydrochloric acid aqueous solution/h5
The mixture was mixed and stirred to obtain a colorless and transparent homogeneous aqueous solution.

そこに超微粉末シリカ（ＡｅｒｏａｉｔＯＸ５０）２．
０ｋを除々に添加し、液温を２５℃に保ち攪拌しながら
超音波（２，４Ｈｚ）を２時間照射し、充分均一な溶液
とした。この分散液を遠心分離機で１５００Ｇで５分間
処理し之後、上澄み液を１μのフィルターを介した。こ
の分散液をＰＨ４０にするためＱｌ規定アンモニア水を
添加した。Ultrafine powdered silica (AeroaitOX50) 2.
0k was gradually added, and while the liquid temperature was kept at 25° C. and stirred, ultrasonic waves (2.4 Hz) were irradiated for 2 hours to obtain a sufficiently uniform solution. This dispersion was centrifuged at 1500G for 5 minutes, and the supernatant was passed through a 1μ filter. In order to adjust the pH of this dispersion to 40, Ql normal ammonia water was added.

調整されたゾルを、ポリエチレン製容器に（３００Ｊ×
１５調）に１ｔずつ、計１２個に注入し、密閉した後、
室温３０℃に制御された場所に一昼夜放置した。この後
、容器のフタに開孔率１％となるよう穴を開け、６０℃
の恒温槽に入れ、１０日間で取シ出したところ、２１　
ｏ擢ｘ７１１ＪＩの白色で板状のドライゲルが得られた
。The adjusted sol was placed in a polyethylene container (300J x
After injecting 1 ton each into 12 pieces (15 tones) and sealing them,
It was left overnight in a place where the room temperature was controlled to 30°C. After this, holes were made in the lid of the container so that the porosity was 1%, and the temperature was increased to 60°C.
When I put it in a constant temperature bath and took it out after 10 days, it turned out to be 21
A white, plate-shaped dry gel of 擢x711JI was obtained.

電気炉内にセントされた石英容器は、エアの流入口、排
気口があり、ガスは、送風ボンダを使用して石英容器内
をフローするようにした。この石英容器内に該ドライゲ
ルを６枚たてかけた。流入するエアーの途中には、塩化
カルシウム管を介し、エアー中の水分を除去するように
した。この状態で３００℃、５００℃、９００℃、　１
ｏｏｏ℃でそれぞれ２時間保持した。尚、昇温速度は一
律に６０℃毎時とした。またエアーの流入量は３を毎時
にした。The quartz container placed in the electric furnace had an air inlet and an air outlet, and gas was made to flow through the quartz container using a blower bonder. Six sheets of the dry gel were stacked vertically in this quartz container. In the middle of the inflowing air, a calcium chloride pipe was used to remove moisture from the air. In this state, 300℃, 500℃, 900℃, 1
Each was held at ooo°C for 2 hours. Note that the temperature increase rate was uniformly set at 60° C./hour. In addition, the air inflow rate was set to 3 per hour.

この後、炉内放冷して取り出したところ、１９６−×６
２−の白色板状の焼結ゲルが得られ次。またセットし之
６枚とも、割れ、クラック等の発生は見られなかった。After that, when I let it cool in the furnace and took it out, it turned out to be 196-×6
2- A white plate-shaped sintered gel was obtained. Furthermore, no breakage, cracks, etc. were observed in any of the six sheets set.

これをさらに黒鉛発熱炉にて１７５０℃に加熱し、３０
分間保持した後、１２００℃まで１０００℃毎時、それ
以下は１００℃毎時で降温し、取シ出したところ、１５
１ｒｊｊ’　Ｘ　５．１−の無色透明な石英ガラス６枚
が得られた。This was further heated to 1750°C in a graphite heating furnace, and
After holding for 1 minute, the temperature was lowered at 1000°C/hour up to 1200°C, and at 100°C/hour below that, and when taken out, the temperature was 15°C.
Six pieces of colorless and transparent quartz glass of 1rjj' x 5.1- were obtained.

得られたガラスを１２７７Ｘ２．３Ｗｒ！の形状とし鏡
面研摩し念後、暗室にて２０００ルクスの光をあてたが
、気泡、介在物等による光点は見られなかった。さらに
赤外吸収にて含水率を測定したところα０５ｗｔ％〜α
１ｖｔ％を示した。The obtained glass was 1277X2.3Wr! After mirror polishing the shape, I exposed it to 2000 lux light in a dark room, but no light spots due to bubbles, inclusions, etc. were observed. Furthermore, when the water content was measured using infrared absorption, α05wt%~α
It showed 1vt%.

〔比較例〕 実施例で得られたドライゲルの残シロ枚を、電気炉内に
石英容器に入れ、エアーは流入せず、自然排気する形に
し、実施例と同様に％電気炉では３００℃、５００℃、
９００℃、　１ｏｏｏ℃でそれぞれ２時間保持した後、
取シ出したところ、４６枚牧牛枚について割れ、クラッ
ク発生が見られた。[Comparative Example] The remaining sheets of the dry gel obtained in the example were placed in a quartz container in an electric furnace, and air was not allowed to flow in, but the air was naturally exhausted. 500℃,
After holding at 900℃ and 1ooo℃ for 2 hours,
When the sheets were taken out, 46 sheets were broken and cracks were observed.

寸法は１９４ｔｍ　×ｆｓ、５ｒｍで白色板状であつ九
。これをさらに黒鉛発熱炉にて１７５０℃に加熱し、３
０分間保持した後、１２００℃まで１０００℃毎時、そ
れ以下は１００℃毎時で降温し、取シ出したところ、ｆ
　５　ｆ　ｔｊｊ　Ｘ　５．１−の無色透明な石英ガラ
スが得られた。これも実施例と同様に割れなかりな３枚
について鏡面研摩した後、暗室にて２０００ルクスの光
をあてたところ、気泡、介在物等による光点が伺ケ所か
に確認された。これを透過型顕微鏡で１００倍で観察し
念ところ、いずれも１０〜１００μレベルの気泡であっ
た。さらに赤外吸収にて含水率を測定したところα１８
〜ａ２５ｖｔ％であった。The dimensions are 194tm x fs, 5rm, and a white plate shape. This was further heated to 1750°C in a graphite heating furnace, and
After holding for 0 minutes, the temperature was lowered at 1000°C/hour up to 1200°C, and at a rate of 100°C/hour below that, and when taken out, f
A colorless and transparent quartz glass of 5 f tjj x 5.1- was obtained. Similarly to the example, three pieces with no cracks were polished to a mirror surface, and when 2000 lux light was applied in a dark room, light spots due to air bubbles, inclusions, etc. were observed in some places. When this was observed under a transmission microscope at 100 times magnification, it was found that all the bubbles were on the 10-100 micron level. Furthermore, when the water content was measured using infrared absorption, α18
~a25vt%.

〔発明の効果〕〔Effect of the invention〕

以上述べたように、本発明によれば、少なくともアルキ
ルシリケートを原料とし、ゾル−ゲル法によシ作成し九
ガラスあるいは、ガラス前駆体を加熱し、一定時間保持
する石英ガラスの合成において、そのガラス前駆体とし
てのドライゲルを。As described above, according to the present invention, in the synthesis of quartz glass produced by the sol-gel method using at least an alkyl silicate as a raw material, or by heating a glass precursor and holding it for a certain period of time, dry gel as a glass precursor.

気体フロー系内にドライエアーを流入しながら１０００
℃まで昇温、保持することＫよって、この焼結段階での
割れ、クラック等の現象が無くなると同時に、１０００
℃以上に加熱保持した後のガラスとしての品質が極めて
良好になるという派生効果を生じ、ＩＣマスクの大型化
への応用が可能となつ之。1000 while flowing dry air into the gas flow system.
By raising the temperature to ℃ and holding it, phenomena such as cracks and cracks in this sintering stage are eliminated, and at the same time
A secondary effect is that the quality of the glass becomes extremely good after being heated and maintained at temperatures above ℃, making it possible to apply it to larger IC masks.

以上that's all

Claims (1)

【特許請求の範囲】[Claims] （１）少なくとも、アルキルシリケートを原料とし、ゾ
ル−ゲル法で作成した、ガラスあるいは、ガラス前駆体
を、加熱し、一定時間保持する石英ガラスの合成におい
て、そのガラス前駆体としてのドライゲルを、気体フロ
ー系でドライエアーを流入しながら、１０００℃まで昇
温、保持することを特徴とする石英ガラスの製造方法。(1) At least in the synthesis of silica glass, which uses alkyl silicate as a raw material and creates glass or a glass precursor by the sol-gel method, the dry gel as the glass precursor is heated and held for a certain period of time. A method for manufacturing quartz glass characterized by raising and maintaining the temperature to 1000°C while flowing dry air in a flow system.