JPS62113737A - Production of quartz glass - Google Patents

Abstract

PURPOSE:To obtain glass of high quality containing very small amounts of impurities, crystals, air bubbles and foreign materials of irregular shape, by gelatinizing a specific sol solution, drying the resultant gel and sintering the dried gel. CONSTITUTION:An alkyl silicate is hydrolyzed with a basic reagent to give the first solution containing fine silica particles having 0.01-1.0mu average particle diameter in 0.05g/ml concentration. On the other hand, an alkyl silicate is hydrolyzed with an acidic reagent to give the second solution, which is mixed with the first solution to afford 0:100-100:0 molar ratio of the silicon respectively contained in the first and second solutions and give a sol solution at >=3pH containing >=0.10g/ml effective available silica content, which is then put in a vessel in a given shape made of a hydrophobic material, gelatinized in a hermetically sealed state and kept at 10-50 deg.C. The resultant wet gel is then shrunk at >=8% linear shrinkage and dried in a vessel with <=10% opening ratio while heating from 20 deg.C to a temperature within 50-160 deg.C range at <=120 deg.C heating rate/hr to afford a dried gel, which is sintered to give the aimed transparent glass material.

Description

【発明の詳細な説明】 〔産業上の利用分骨〕 本発明はゾル−ゲル法による石英ガラスの製造方法に明
するう 〔従来の技術〕 従来からゾル−ゲル法による石英ガラスの製造方法が何
例か報告されている。（（１）野上、中釜らＪｏｎｒｎ
ａｌ　ｏｆ　Ｎｏｎ−０ｒｙｓｔａｌｌｉｎｓ　Ｓｏｌ
：ｄｓ、　　３７゜１９１　（１９８０）　　（２）ラ
ビノービッヒら、Ｊｏｎｒｎａ’１ｏｆ　Ｎｏｎ−０ｒ
ｙｓｔａｌｌｉｎｅ　５ｏｌｉｄｓ、　４７　、４５５
（１９８２）　　（３）土岐ら、特、頌１１ｆ１５８−
２５７５７７）なかでも土岐らの方法は超微粉末シリカ
微粒子ぐ均一に分散させ几金属アルコキシド加水分解溶
液のＰＨＶＬを３〜６に調整し之ゾルを用いて得られる
多孔性のドライゲルｔｉ結するという構成ｔＶしている
ｔめ、他の２例では作製することの困難な大きさの石英
ガラス（例えば１５５Ｘ　１５３ＸＣＬ　５　ｔｙｎ　
）　ｆ歩留Ｏしく作製でき、石英ガラスの製造方法とし
て最もすぐれている。[Detailed Description of the Invention] [Industrial Application] The present invention is directed to a method for producing quartz glass by a sol-gel method [Prior Art] Conventionally, a method for producing quartz glass by a sol-gel method Several cases have been reported. ((1) Nogami, Nakagama et al.
al of Non-0rystallins Sol
:ds, 37°191 (1980) (2) Rabinovich et al., Jonrna'1 of Non-0r
ystalline 5olids, 47, 455
(1982) (3) Toki et al., Special Ode 11f158-
Among them, the method of Toki et al. consists of uniformly dispersing ultrafine silica particles, adjusting the PHVL of a metal alkoxide hydrolysis solution to 3 to 6, and condensing a porous dry gel obtained using this sol. Due to the t
) It can be manufactured with a high yield and is the most excellent method for manufacturing quartz glass.

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

しかし、従来の土岐らの製造方法では、焼結して出未几
石英ガラス中に、金属イオン等の不純物、結晶、気泡、
不定形状の異物が含まれやすく、九とえば光フアイバ用
母材やフォトマスク用石英基板等の特に高品質を要求さ
れる用途に使用する場合、品質的に問題があつ几。However, in the conventional manufacturing method of Toki et al., impurities such as metal ions, crystals, bubbles, etc.
It tends to contain irregularly shaped foreign matter, which causes quality problems when used in applications that require particularly high quality, such as base materials for optical fibers and quartz substrates for photomasks.

そこで、本発明は従来のこのような品質上の問題点を解
決するもので、その目的は、金属イオン等の不純物、結
晶、気泡、不定形状の異物のない均質で高品質な石英ガ
ラスを製造する方法を提供するところにある。Therefore, the present invention solves these conventional quality problems, and its purpose is to manufacture homogeneous, high-quality quartz glass that is free from impurities such as metal ions, crystals, bubbles, and irregularly shaped foreign substances. We are here to provide you with a way to do so.

〔発明の概要〕[Summary of the invention]

本発明は、ゾル−ゲル法による石英ガラスの製造方法に
おいて、前記石英ガラスの製造方法がアルキルシリケー
トを、塩基性触媒で加水分解して得られるシリカ微粒子
を溶液中に含む第一の溶液と、アルキルシリケートを、
酸性試薬で加水分解して得られる第二の溶液とを、所定
の割合で混合して得られるゾル溶液をゲル化させてウェ
ットゲルを作る工程、前記ウェットゲルを乾燥してドラ
イゲルを作る工程、前記ドライゲルを焼結して透明ガラ
ス体とする工程からなることにエフ、極めて高品質の石
英ガラスを低コストで製造することができるようにし次
ものである、 〔問題点を解決するための手段〕 本発明の石英ガラスの製造方法は、アルキルシリケート
を、塩基性試薬で加水分解して得られるシリカ微粒子を
溶液中に含む第一の溶液と、アルキルシリケートヲ、酸
性試薬で加水分解して得られる第二の溶液とを、所定の
割合で混合して得られるゾル溶液をゲル化させてウェッ
トゲルを作る工程、前記ウェットゲルを乾燥してドライ
ゲルを作る工程、前記ドライゲルを焼結して透明ガラス
体とする工程からなることを特徴とする。The present invention provides a method for producing quartz glass by a sol-gel method, wherein the method for producing quartz glass includes a first solution containing fine silica particles obtained by hydrolyzing an alkyl silicate with a basic catalyst; alkyl silicate,
A step of gelling a sol solution obtained by mixing a second solution obtained by hydrolysis with an acidic reagent at a predetermined ratio to form a wet gel, a step of drying the wet gel to form a dry gel, The process of sintering the dry gel to form a transparent glass body makes it possible to manufacture extremely high quality quartz glass at low cost. [Means for solving the problem] ] The method for producing quartz glass of the present invention includes a first solution containing fine silica particles obtained by hydrolyzing an alkyl silicate with a basic reagent, and a first solution containing fine silica particles obtained by hydrolyzing the alkyl silicate with an acidic reagent. a step of gelling the sol solution obtained by mixing the sol solution with a second solution in a predetermined ratio to form a wet gel; a step of drying the wet gel to form a dry gel; and a step of sintering the dry gel to make it transparent. It is characterized by a process of forming a glass body.

本発明の石英ガラスの製造方法は、原料として高純度な
液体原料を選べるので金属イオン等の不純物や、ゴミ、
チリ、その他の異物がなく、本質的に高品質な石英ガラ
スを作ることができるが、大きなサイズまで歩留０工ぐ
経済的に作製するｔめには以下の条件を選ぶことが望ま
しい。The method for producing quartz glass of the present invention allows the selection of highly pure liquid raw materials as raw materials, which eliminates impurities such as metal ions, dust, etc.
Although it is possible to produce essentially high-quality quartz glass without dust or other foreign matter, it is desirable to select the following conditions for economical production with zero yield up to large sizes.

１）第一の溶液中に含まれるシリカ微粒子の平均粒径が
１０１〜１．０μｍの範囲にあること２）第一の溶液中
に含まれるシリカ微粒子の濃度が１０５１／−以上であ
ること ３）第一の溶液と第二の溶液ｔ、含まれるシリコンのモ
ル比でｏ　：　１ｕｕ〜Ｉ　Ｄｏ　：　０の範囲、さら
に望ましくは２０：８０〜８５：１５の１厄囲の所定の
割合で混合すること ４）ゾル溶液中の有効シリカ分の濃度がＱ、１０ｆ／−
以上であること ５）ゾル溶液のＰＨＶＬを３以上の所定の値に調整しｔ
後ゲル化させること ６）ゾル溶液を所定形状の容器に移しｔ後、密゛閉状態
にてゲル化させ１０〜５０℃にて保持し、ウェットゲル
がある糧度、望ましくは線収縮率で８慢以上、収縮して
から乾燥ｔ−開始すること７）　ウェットゲルの乾燥を
１１］チ以下の開口重上もつ几答器の中で行なうこと ８）容器のゾル溶液と接触する面の材料は疎水性の材料
であること ９）ウェットゲルの乾燥を２０℃から昇温速度１２０℃
／ｈｒ以下で５０〜１６０℃の範囲の所定の温度まで昇
温することによって行なうこと１０）　ドライゲルを焼
結して透明ガラス体とする工程が以下の５つの工程から
なること （１）　　脱吸着水処理ｔする工程 （２）　　脱炭素処理金する工程 （３）　　脱水縮合反応の促進処、ＱＪ　ｙ、する工程
１１）脱吸着水処理を、昇温速度４００℃／　ｈ　ｒ以
下で２０〜４０１Ｊ℃の範囲の所定の温度に昇温し、必
要ならその温度で１時間以上保持して行なうこと １２）脱炭素処理ｔ、昇温速度３　Ｑ　〜４００／ｈｒ
で４００〜９００℃の範囲内の所定の温度に昇温して行
なうこと １３）脱水縮合反応の促進処理を、昇温速度１〜４００
℃／　ｈｒ　テ９１Ｊ　Ｏ〜１５　ｕ　０℃の範囲内の
所定の温度に昇曳し、必要ならその温度で５０分以上保
持して行なうこと １４）開孔化処理を、昇温速度５０〜４００℃／ｈｒで
９１Ｊ　Ｏ〜１４ＱＵ℃の範囲内の所定の温度に昇湿し
、必要ならその温度で１時間以上保持して行なうこと １５）透明ガラス化処理’ｉ、１２００〜２ｔ］００℃
の範囲の所定の温度に昇温し、所定の時間そのｉ度で保
持して行なうこと このうち条件１）３）５）は、主に焼結工程で割れにく
い多孔性のドライゲル全作製する几めの条件であり、条
件２）４）は王に乾燥工程で割れにくい組成のウェット
ゲルを作製する几めの条件であり、条件６）７）Ｂ）９
）は歩留りよくドライゲルを作製するための熟取、乾燥
条件であり、条件１０）　１１）　１２）　１５）　１
４）　１５）　　は歩留りよく透明ガラス体を作製する
ｔめの焼結条件である。1) The average particle size of the silica fine particles contained in the first solution is in the range of 101 to 1.0 μm.2) The concentration of the silica fine particles contained in the first solution is 1051/- or more.3 ) The first solution and the second solution t are mixed at a predetermined ratio of silicon contained in a molar ratio of O: 1 uu to I Do: 0, more preferably 20:80 to 85:15. 4) The concentration of effective silica in the sol solution is Q, 10f/-
5) Adjust the PHVL of the sol solution to a predetermined value of 3 or more.
Post-gelling 6) After transferring the sol solution to a container of a predetermined shape, it is gelled in a tightly closed state and kept at 10 to 50°C to form a wet gel with a certain density, preferably a linear shrinkage rate. Start drying after the gel has shrunk for more than 8 hours. 7) Dry the wet gel in a container with an opening size of 11 or less. 8) The material on the surface of the container that will come into contact with the sol solution. is a hydrophobic material 9) Dry the wet gel at a heating rate of 120°C from 20°C.
10) The process of sintering the dry gel to form a transparent glass body consists of the following five steps (1) Desorption Water treatment process (2) Decarbonization process (3) Dehydration condensation reaction acceleration process, QJy process 11) Desorption water treatment at a heating rate of 400°C/hr or less for 20 to 401J Raising the temperature to a predetermined temperature in the range of ℃ and holding it at that temperature for 1 hour or more if necessary 12) Decarbonization treatment t, heating rate 3 Q ~ 400/hr
13) Accelerating the dehydration condensation reaction at a heating rate of 1 to 400°C.
°C/hr Te91J O~15 u Raise the temperature to a predetermined temperature within the range of 0℃, and if necessary, hold at that temperature for 50 minutes or more 14) Perform the pore opening treatment at a temperature increase rate of 50~400 15) Transparent vitrification treatment 'i, 1200-2t] 00°C
Conditions 1), 3) and 5) are mainly used to create a porous dry gel that is difficult to break during the sintering process. Conditions 2) and 4) are strict conditions for producing a wet gel with a composition that is difficult to break during the drying process, and conditions 6), 7), and B) 9.
) are carefully selected and drying conditions for producing dry gel with good yield, conditions 10) 11) 12) 15) 1
4) 15) are the tth sintering conditions for producing a transparent glass body with a good yield.

以上の方法を用いることによって従来のものエフ、金属
イオン等の不純物、結晶、気泡、不定形状の異物が極め
て少ない高品質の石英ガラスが作製できるが、以下の条
件を選ぶとさらに気泡、不定形状の！Ａ物を減らすこと
ができる。By using the above method, it is possible to produce high-quality quartz glass with very few impurities such as conventional F, metal ions, crystals, bubbles, and irregularly shaped foreign substances, but if the following conditions are selected, bubbles and irregularly shaped of! You can reduce the amount of A items.

１６）開孔化処理を以下の３つの方法のうちいずれかの
方法を用いて行なうこと （１１Ｈｅ雰囲気中で開孔化する （２）減圧下で開孔化する （３）ＥｅｙＪ囲気にし九後減圧にして開孔比する １７）開孔化処理の前に脱ＯＨ基処理と、脱塩素処理あ
るいは脱フツ素処理を行なうこと条件１４）は、開孔の
内部ｆ　Ｈｅで満たすか、あるいは減圧にし、透明ガラ
ス化する時に生成しやすかった主に１μｍ以下の微小な
気泡や異物に含まれる空間を消滅させるだめの条件であ
る。また条件１５）はガラス中のＯＨ基を減らす定めの
条件であり、この条件な用いると、透明ガラス化する時
に工Ｖ発泡しにくくなり、透明ガラス化の工程゛が集に
行なえる工うになる。ｔた含水率の極めて低い石英ガラ
スを得ることができる。16) Perform the pore-forming treatment using one of the following three methods (forming the pores in an 11He atmosphere (2) forming the pores under reduced pressure (3) after 9 days in an EeyJ atmosphere. 17) Perform OH group removal treatment, dechlorination treatment, or defluorination treatment before the pore formation treatment Condition 14) is to fill the inside of the pores with f He or reduce the pressure. This is a condition that eliminates the spaces contained in microbubbles and foreign matter, mainly 1 μm or less, which tend to be generated during transparent vitrification. Condition 15) is a predetermined condition for reducing the OH groups in the glass, and when this condition is used, it becomes difficult to form bubbles during transparent vitrification, and the process of transparent vitrification can be carried out more efficiently. . It is possible to obtain quartz glass with extremely low water content.

これらの方法を用いることによって、例えば、フォトマ
スク用石英基板等の特に高品質を要求される用途に弔い
られる極めて高品質な石英ガラスを容易に作製すること
ができろ、 またこうした作製できる極めて高品質な石英ガラス２以
下の方法を併用することに工って、さらに安定して歩留
り良く天運することができる。By using these methods, it is possible to easily produce extremely high-quality quartz glass, which is used in applications that require particularly high quality, such as quartz substrates for photomasks. By combining the methods below with high-quality quartz glass, it is possible to achieve a more stable and high yield.

１）第一のｔ８液と第二の溶液の原料は高純間のものを
使用し、蒸留、濾過（孔径［Ｌ２μｍ以下のフィルター
）等によって微小なゴミ、異物を除いて〉くこと ２）ゾル溶液を所定の容器に移し入れるまでの操作ｔク
ラス５ｕｕｏ以下、望ましくはクラス１０ＥＩ以下のク
リーンな環境で行なうこと３）第一の溶液に５Ｕ〜１ｕ
ＵＯｕＧの遠心力をかけｔ後、そのうわずみ液を用いて
第二の溶液と混合すること ４）第一の溶液全５０μｍ工ｖａＩかいフィルター１用
いて１回以上濾過しｔ後、第二の溶液と混合すること ５）第二の溶液を５０μｍよＶ細かいフィルターを用い
て１回以上濾過した後、第一の溶液と混合すること ６）ゾル溶液ｔ−５０μｍより細かいフィルターを用い
て１回以上濾過すること ７）ゾル溶液をゲル化までの工程の中で少なくとも一度
、減圧処理を行なうこと ８）ゾル溶液全所定の容器に移し入れ、５０〜５００Ｇ
の遠心力ｔかけながらゲルイヒさせること上記１）　４
）　５）　６）　　について、用いるフィルターは使え
る範囲で細かい方が望ましいのはいうまでもない。1) The raw materials for the first T8 solution and the second solution should be of high purity, and minute dust and foreign matter should be removed by distillation, filtration (filter with a pore diameter of L2 μm or less), etc.2) The operation until the sol solution is transferred to the designated container must be carried out in a clean environment of class 5 uuo or less, preferably class 10EI or less. 3) Add 5 U to 1 u to the first solution.
After applying the centrifugal force of UOuG, use the vasa to mix with the second solution. 4) Filter the first solution at least once using a 50 μm VAI filter 1, then use the second solution. Mixing with the solution 5) Filtering the second solution one or more times using a filter finer than 50 μm and then mixing with the first solution 6) Filtering the sol solution once using a filter finer than 50 μm 7) Perform vacuum treatment on the sol solution at least once during the process up to gelation 8) Transfer the entire sol solution to a designated container and apply 50 to 500 g
1) 4 above.
) Regarding 5) and 6), it goes without saying that it is desirable that the filter used be as fine as possible.

〔実施例〕〔Example〕

■　第一の溶液の作製 蒸留ｍｆｉ　Ｌ几エチルシリケート、蒸留４ＭＬｅｅエ
タノール、蒸留Ｍｆｆしｔ水、と（１，２μｍの孔径勿
もつメンブランフィルタ−にＬつ゛て濾過し定市販特級
の２９％アンモニア水を第−表に示し定組成で混合し、
４時間激しく攪拌した後、冷暗所にて一晩静置しシリカ
微粒子ｔｇ長させた。この溶液ｔ−ｍ縮した後、ＰＨ値
を調整し、１０μｍの孔径をもつメンブランフィルタ−
を通し、第一の溶液を作製した。■ Preparation of the first solution Distilled mfiL ethyl silicate, distilled 4M Lee ethanol, distilled Mfft water, and (filtered through a membrane filter with a pore size of 1.2 μm) and commercially available special grade 29% ammonia water. are shown in the table and mixed at a constant composition,
After vigorously stirring for 4 hours, the mixture was allowed to stand overnight in a cool, dark place to increase the length of the silica particles. After condensing this solution for tm, the pH value was adjusted and a membrane filter with a pore size of 10 μm was used.
A first solution was prepared.

第−表 なお、得られた第一の溶液Ａ、第一の容器Ｂ、第一の溶
？％ＩＣに含まれるシリカ微粒子の平均粒径は、それぞ
れａ、１５μ、［１Ｌ２５μ、ｒｌ、４０μｍであつ九
。Table 1 also shows the obtained first solution A, first container B, first solution? The average particle diameters of the silica fine particles contained in %IC are a, 15μ, [1L25μ, rl, and 40μm, respectively.

■　第二の溶液の作製 蒸留稽展したエチルシリケー）　１　＆９　ｔＫｒｌ、
２μｍの孔径ｔもつメンブランフィルタ−に工って濾過
し几１１０２規定の塩酸＆１ｓｔを加え、激しく攪拌し
て加水分屏し、第二の溶液とした。なお第二の溶液は全
部で３つ作製し次。■ Preparation of the second solution Distilled ethyl silica) 1 & 9 tKrl,
The mixture was filtered through a membrane filter with a pore diameter of 2 μm, and 1102 normal hydrochloric acid &1st was added thereto, and the mixture was vigorously stirred and hydrolyzed to obtain a second solution. A total of three second solutions were prepared.

■　ゾル溶液の作製 第一の溶液人と第二の溶液のうちの１つ全混合し、その
後１８μｍの孔径ｔもつメンブランフィルタ−に１って
一過し、ゾルメ液Ａｔ−作製し之。(2) Preparation of sol solution The first solution and one of the second solutions were completely mixed, and then passed through a membrane filter with a pore size of 18 μm to prepare a sol solution At.

同様にして第一の溶液Ｂと第二の溶液のうちの１つ全混
合し、その後２．０μｍの孔径をもつメンブランフィル
タ−によって濾過し、ゾル溶液８２作製し九〇 同様にしてＰ−の溶液Ｃと第二の溶液のうちの１つを混
合し、その後入〇μｍの孔径をもつメンブランフィルタ
−によって濾過し、ゾル溶製Ｃｔ−作製した。なお上記
のゾル溶液のＰＨ値と、液温はそれぞれ４，５．２０℃
であった。In the same manner, the first solution B and one of the second solutions were completely mixed, and then filtered through a membrane filter with a pore size of 2.0 μm to prepare sol solution 82. Solution C and one of the second solutions were mixed and then filtered through a membrane filter with a pore size of 0 μm to prepare a sol solution Ct. The pH value and liquid temperature of the above sol solution are 4 and 5.20°C, respectively.
Met.

■　ゲル化と乾燥 次に前記ゾル溶液Ａ４５０コの容器（内寸で５００藺　
×１００間　）に９００づずつ移し入れ、フタをして密
閉した状態でゲル化させ、５０コのウェットゲルを作製
した。同様にして前記ゾル溶液Ｂとゾル溶液Ｃから、そ
れぞれ５ｕコのウェットゲル全作製した。つぎに、得ら
れ之１５０コのウェットゲルｋｆｆｉ閉状態の′１まで
３０℃で５日間熟成し、その後α４チの開口率をもった
フタにと９かえ６５℃で乾・凍させたところ１４日間で
、大気中に放課しても割れない安定なドライゲルが第二
表に示した歩留りでイＪらｆ′した。■ Gelling and drying Next, add a container containing 450 pieces of the above sol solution A (inner size: 500 pieces).
50 wet gels were prepared by transferring 900 gels into 100 × 100 × 100 × 100 × 100 × 100 × 100 tubes and gelling them with the lids closed. In the same manner, 5 u of each wet gel was prepared from the sol solution B and sol solution C. Next, the obtained 150 wet gel kffi were aged at 30°C for 5 days until the closed state '1', then changed to a lid with an opening ratio of α4, and dried and frozen at 65°C. A stable dry gel that did not crack even when exposed to the atmosphere was produced at the yield shown in Table 2 in a few days.

第二表 ■焼結 前記３種のドライゲルｔ−１０枚ずつ焼結炉に入れ昇温
速度６０°Ｃ／ｈｒで５０°Ｃから２００°Ｃまで加熱
し、この温度で５ＩｆＦ間保持し、つづいて２００°Ｑ
　２ｈら３００°Ｃまで昇温速度６０°Ｃ／ｈｒで加熱
し、この温度で５時間保持して脱吸着水処理を行なつ友
。Table 2 - Sintering 10 pieces of each of the above three types of dry gel t-shirts were placed in a sintering furnace and heated from 50°C to 200°C at a heating rate of 60°C/hr, held at this temperature for 5 IfF, and continued. te 200°Q
Heat the sample to 300°C for 2 hours at a temperature increase rate of 60°C/hr and hold it at this temperature for 5 hours to perform desorption water treatment.

つづいて昇温速度６０°Ｃ／ｈｒで３００°Ｃから７０
０°Ｃまで加熱し、この温度で２０時間保持し。Continue from 300°C to 70°C at a heating rate of 60°C/hr.
Heat to 0°C and hold at this temperature for 20 hours.

つづいて昇温速度６０°Ｃ／ｈｒで７００°Ｃから９０
０°Ｃまで加熱し、この温度で１０時間保持し。Continue from 700°C to 90°C at a heating rate of 60°C/hr.
Heat to 0°C and hold at this temperature for 10 hours.

つづいて昇温速度６０°Ｃ／ｈｒで９００°Ｃ〃為ら１
０００°Ｃまで加熱し、この温度で１０時間保持して脱
炭素、脱塩化アンモニウム処理、脱水縮合反応の促進処
理上行なった。Next, heat up to 900°C at a heating rate of 60°C/hr.
The sample was heated to 000°C and maintained at this temperature for 10 hours to perform decarbonization, dechlorination ammonium treatment, and dehydration condensation reaction acceleration treatment.

つづいて炉内にＨｅガスを流しながら昇温速度６０°Ｃ
／ｈｒで１２００’Ｃまで加熱し、この温度で２時間保
持して閉孔化処理を行なった。Next, while flowing He gas into the furnace, the temperature was increased to 60°C.
/hr to 1200'C and held at this temperature for 2 hours to perform pore-closing treatment.

その後昇温速度６０’Ｃ／ｈｒで１３００°Ｃまで加熱
し、この温度で１時間保持したところ無孔化し１歩留り
１００％で５０枚の透明ガラスが得られた。Thereafter, the glass was heated to 1300°C at a heating rate of 60'C/hr and held at this temperature for 1 hour, resulting in 50 pieces of transparent glass with a 100% yield.

この石英ガラスの両面を研磨して１５２鵡０×。Both sides of this quartz glass were polished to 152mm 0x.

３ｍｔの石英ガラス板が得られた。A 3 mt quartz glass plate was obtained.

本実施例で得られ九石英ガラス板は観測される異物がな
く極めて高品質であった０まｔ紫外・可視域での分光特
性もフラットであシ、ＩＣ製造に用いられるフォトマス
ク基板として使用され得る品質であった。The quartz glass plate obtained in this example had no observed foreign matter and was of extremely high quality.The spectral characteristics in the ultraviolet and visible regions were also flat, and it was used as a photomask substrate used in IC manufacturing. The quality was as good as it could be.

〔実施例２〕 実施例１で得られ次前記３種のドライゲルを１０枚ずつ
＠ｔ３０枚）次の焼結プログラムに従って焼結しｆｃ。[Example 2] The three dry gels obtained in Example 1 were sintered (10 sheets each @30 sheets) according to the following sintering program.

昇温速度３０°Ｃ／ｈｒで６０°Ｃから２００°Ｃまで
加熱し、この温度で５時間保持し、つづいて２００°Ｃ
ｚｈら３００°Ｃまで昇温速度３０°Ｃ１ｈｒで加熱し
、この温度で５時間保持して脱吸着水処理上行なった。Heating from 60°C to 200°C at a heating rate of 30°C/hr, holding at this temperature for 5 hours, then heating to 200°C
The sample was heated to 300° C. at a rate of temperature increase of 30° C. 1 hr, and maintained at this temperature for 5 hours to perform desorption water treatment.

つづいて昇温速度３０°Ｃ／ｈｒで３００°Ｃ〃為ら７
００°Ｃまで加熱し、この温度で２０時間保持し。Next, heat up to 300°C at a heating rate of 30°C/hr.7
Heat to 00°C and hold at this temperature for 20 hours.

つづいて昇温速度３０°Ｃ／ｈｒで７００’Ｃから９０
０°Ｃまで加熱し、この温度で１０時間保持して、脱炭
素、脱塩化アンモニウム処理、脱水縮合の促進処理を行
なった。Continue from 700'C to 90°C at a heating rate of 30°C/hr.
It was heated to 0°C and held at this temperature for 10 hours to perform decarbonization, dechlorination ammonium treatment, and dehydration condensation acceleration treatment.

つづいて７００°Ｃまで降温しＨｅ２Ｒ／ｓ＋ｍ−０２
１α２ｆｉ／ｍの混合ガスを流しながら３０分間保持し
、昇温速度３０°Ｃ／ｈｒで１０００°Ｃまで加熱し、
この温度で５時間保持して、脱ＯＨ基処理を行なった。Subsequently, the temperature was lowered to 700°C and He2R/s+m-02
Hold for 30 minutes while flowing a mixed gas of 1α2fi/m, and heat to 1000°C at a temperature increase rate of 30°C/hr.
This temperature was maintained for 5 hours to perform OH group removal treatment.

つづいて０１ガスｆ２１ｔ１ｍで流しながら、この温度
で１時間保持し、その後昇温速度６０°Ｃ／ｈｒで１１
００°Ｃまで加熱し、この温度で２０時間保持して脱塩
素処混ヲ行なった。Next, while flowing 01 gas f21t1m, this temperature was maintained for 1 hour, and then the heating rate was 60°C/hr for 11 hours.
The mixture was heated to 00°C and held at this temperature for 20 hours to perform dechlorination treatment.

つづいてＨｅガスｆ２Ａｌ■で流しながら、この温度で
１時間保持し、その後昇温速度３０°Ｃ／ｈｒで１２０
０°Ｃまで加熱し、この温度で１０時間保持し、その後
昇温速度３０’Ｃ／ｈｒで１２５０°Ｃまで加熱し、こ
の温度で１０時間保持して閉孔化処理を行なった０ その後昇温速度６０°Ｃ／ｈｒで１４００°Ｃまで加熱
し、この温度で１時間保持したところ無孔化し１歩留ｐ
１００％で３０枚の透明ガラスが得られた。Subsequently, the temperature was maintained at this temperature for 1 hour while flowing with He gas f2Al■, and then heated to 120°C at a temperature increase rate of 30°C/hr.
It was heated to 0°C, held at this temperature for 10 hours, then heated to 1250°C at a heating rate of 30'C/hr, and held at this temperature for 10 hours to perform pore-closing treatment. When heated to 1400°C at a temperature rate of 60°C/hr and held at this temperature for 1 hour, it became non-porous and 1 yield p
Thirty pieces of transparent glass were obtained at 100%.

この石英ガラスの両面を研Δして１５２１１ｓ口×５襲
ｔの石英ガラス板が得られた。Both sides of this quartz glass were polished to obtain a quartz glass plate with a size of 15211s x 5mm.

本実施例で得らｆｌた石英ガラス板は観測される異物が
なく極めて高品質であった。また紫外・可視域での分光
特性もフラットであり、ＩＣ製造に用いられるフォトマ
スク基板として使用され得る品質であった。さらに含ま
れるＯＨ基も１　ｐｐｍ以下であり、紫外〜赤外域にわ
たる広い範囲において透明であるので各種理化学実験用
セル等にも十分使用できる品質である。The quartz glass plate obtained in this example had no observed foreign matter and was of extremely high quality. Furthermore, the spectral characteristics in the ultraviolet and visible regions were flat, and the quality was such that it could be used as a photomask substrate used in IC manufacturing. Further, the amount of OH groups contained is 1 ppm or less, and it is transparent in a wide range from ultraviolet to infrared, so it is of a quality that can be used in various physical and chemical experiment cells.

〔発明の効果〕〔Effect of the invention〕

以上述べたように本発明によれば、アルキルシリケート
ケ、塩基性試薬で加水分解して得られるシリカ微粒子を
溶液中に含む第一の溶液と、アルキルシリケート？、酸
性試薬で加水分解して得られる落二の溶液とを、所定の
割合で混合して得られる高純度なゾル液をゲル化させて
ウェットゲルを作り、該ウェットゲルを乾燥して多孔性
のドライゲルとした後焼結し透明ガラスとするため、金
属イオン等の不純物、結晶、気泡、不定形状の異物の極
めて少ない高品質の石英ガラスが歩留りよく作製できる
。また焼結工程において閉孔化処理をＢｅ雰囲気で、あ
るいは減圧下で、あるいはＨｅ雰囲気にした後減圧にし
ながら行なうこと。As described above, according to the present invention, an alkyl silicate, a first solution containing fine silica particles obtained by hydrolysis with a basic reagent, and an alkyl silicate? , and Rachiji's solution obtained by hydrolysis with an acidic reagent in a predetermined ratio, gelatinize the high-purity sol solution to make a wet gel, and dry the wet gel to make it porous. Since it is made into a dry gel and then sintered to make transparent glass, high-quality quartz glass with very few impurities such as metal ions, crystals, bubbles, and irregularly shaped foreign substances can be produced with a high yield. In addition, in the sintering process, the pore-closing treatment is performed in a Be atmosphere, under reduced pressure, or under reduced pressure after being in a He atmosphere.

さらにあるいは閉孔化処理の前に悦ＯＨ基処理と。Furthermore, or before the pore-closing treatment, Etsu OH group treatment is performed.

脱塩素処理あるいは脱フツ素処理を行なうことによって
１βｍ以下の微小な気泡や不定形状の異物をもほぼ完全
に取り除くことができ極めて高品質の石英ガラスが作製
できる。さらにゴミ、異物等の混入を防ぐ手段と、それ
ら七取シ除ぐ手段を併用することによって、上記の極め
て高品質の石英ガラスを安定して歩ａｂ工〈製造す、る
ことができる。By performing the dechlorination treatment or the defluorination treatment, even minute bubbles of 1βm or less and irregularly shaped foreign matter can be almost completely removed, and extremely high quality quartz glass can be produced. Furthermore, by using means for preventing the incorporation of dust, foreign matter, etc., and means for removing them, the above-mentioned extremely high quality quartz glass can be stably manufactured by ablation.

Claims (3)

【特許請求の範囲】[Claims] （１）アルキルシリケートを、塩基性試薬で加水分解し
て得られるシリカ微粒子を溶液中に含む第一の溶液と、
アルキルシリケートを、酸性試薬で加水分解して得られ
る第二の溶液とを、所定の割合で混合して得られるゾル
溶液をゲル化させてウエツトゲルを作る工程、前記ウエ
ツトゲルを乾燥してドライゲルを作る工程、前記ドライ
ゲルを焼結して透明ガラス体とする工程からなることを
特徴とする石英ガラスの製造方法。(1) a first solution containing fine silica particles obtained by hydrolyzing an alkyl silicate with a basic reagent;
A process of gelling a sol solution obtained by mixing an alkyl silicate with a second solution obtained by hydrolyzing with an acidic reagent at a predetermined ratio to form a wet gel, and drying the wet gel to form a dry gel. A method for producing quartz glass, comprising the steps of: sintering the dry gel to form a transparent glass body. （２）前記焼結して透明ガラス体とする工程において、
開孔化処理を以下の３つの方法のうちいずれかの方法を
用いて行なうことを特徴とする特許請求の範囲第１項記
載の石英ガラスの製造方法。 ガラスの製造方法 １）Ｈｅ雰囲気中で開孔化する ２）減圧下で開孔化する ３）Ｈｅ雰囲気にした後減圧にして開孔化する。(2) In the step of sintering to form a transparent glass body,
2. The method for producing quartz glass according to claim 1, wherein the pore-forming treatment is performed using one of the following three methods. Glass manufacturing method 1) Opening in He atmosphere 2) Opening under reduced pressure 3) Opening under reduced pressure after creating He atmosphere. （３）前記焼結工程において、開孔化処理の前に脱ＯＨ
基処理と、脱塩素処理あるいは税フツ素処理を行なうこ
とを特徴とする特許請求の範囲第１項または第２項記載
の石英ガラスの製造方法。(3) In the sintering process, OH is removed before the pore-forming treatment.
3. A method for producing quartz glass according to claim 1 or 2, characterized in that base treatment and dechlorination treatment or fluorine treatment are performed.