JPH03228817A - Production of anhydrous silica - Google Patents
Production of anhydrous silicaInfo
- Publication number
- JPH03228817A JPH03228817A JP2020393A JP2039390A JPH03228817A JP H03228817 A JPH03228817 A JP H03228817A JP 2020393 A JP2020393 A JP 2020393A JP 2039390 A JP2039390 A JP 2039390A JP H03228817 A JPH03228817 A JP H03228817A
- Authority
- JP
- Japan
- Prior art keywords
- silica
- silanol groups
- water
- tetraalkylammonium
- pore
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 title claims abstract description 157
- 239000000377 silicon dioxide Substances 0.000 title claims abstract description 71
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 9
- 239000011148 porous material Substances 0.000 claims abstract description 44
- 125000005372 silanol group Chemical group 0.000 claims abstract description 27
- 150000005622 tetraalkylammonium hydroxides Chemical class 0.000 claims abstract description 11
- 150000005621 tetraalkylammonium salts Chemical class 0.000 claims abstract description 6
- 238000006460 hydrolysis reaction Methods 0.000 claims abstract description 5
- 230000007062 hydrolysis Effects 0.000 claims abstract description 4
- 238000010304 firing Methods 0.000 claims description 9
- 230000003301 hydrolyzing effect Effects 0.000 claims description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 abstract description 31
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 abstract description 18
- 238000000034 method Methods 0.000 abstract description 16
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 abstract description 8
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 abstract description 7
- 239000002994 raw material Substances 0.000 abstract description 6
- 229910021529 ammonia Inorganic materials 0.000 abstract description 4
- 238000001354 calcination Methods 0.000 abstract description 3
- 239000000203 mixture Substances 0.000 abstract description 2
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 18
- 239000001257 hydrogen Substances 0.000 description 15
- 229910052739 hydrogen Inorganic materials 0.000 description 15
- 239000000499 gel Substances 0.000 description 7
- LFQCEHFDDXELDD-UHFFFAOYSA-N tetramethyl orthosilicate Chemical compound CO[Si](OC)(OC)OC LFQCEHFDDXELDD-UHFFFAOYSA-N 0.000 description 7
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 6
- 238000002835 absorbance Methods 0.000 description 6
- 238000006297 dehydration reaction Methods 0.000 description 6
- 230000000694 effects Effects 0.000 description 6
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 5
- 238000006243 chemical reaction Methods 0.000 description 4
- 230000000052 comparative effect Effects 0.000 description 4
- 239000011259 mixed solution Substances 0.000 description 4
- 230000018044 dehydration Effects 0.000 description 3
- 239000007789 gas Substances 0.000 description 3
- 238000001879 gelation Methods 0.000 description 3
- 229910052757 nitrogen Inorganic materials 0.000 description 3
- 238000007789 sealing Methods 0.000 description 3
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- 238000005033 Fourier transform infrared spectroscopy Methods 0.000 description 2
- BOTDANWDWHJENH-UHFFFAOYSA-N Tetraethyl orthosilicate Chemical compound CCO[Si](OCC)(OCC)OCC BOTDANWDWHJENH-UHFFFAOYSA-N 0.000 description 2
- 239000012159 carrier gas Substances 0.000 description 2
- 238000006482 condensation reaction Methods 0.000 description 2
- 238000009792 diffusion process Methods 0.000 description 2
- 229910052736 halogen Inorganic materials 0.000 description 2
- 125000005843 halogen group Chemical group 0.000 description 2
- 150000002367 halogens Chemical class 0.000 description 2
- 150000002431 hydrogen Chemical class 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- 239000000741 silica gel Substances 0.000 description 2
- 229910002027 silica gel Inorganic materials 0.000 description 2
- 238000001179 sorption measurement Methods 0.000 description 2
- WGTYBPLFGIVFAS-UHFFFAOYSA-M tetramethylammonium hydroxide Chemical compound [OH-].C[N+](C)(C)C WGTYBPLFGIVFAS-UHFFFAOYSA-M 0.000 description 2
- LPSKDVINWQNWFE-UHFFFAOYSA-M tetrapropylazanium;hydroxide Chemical compound [OH-].CCC[N+](CCC)(CCC)CCC LPSKDVINWQNWFE-UHFFFAOYSA-M 0.000 description 2
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 description 1
- CPELXLSAUQHCOX-UHFFFAOYSA-M Bromide Chemical compound [Br-] CPELXLSAUQHCOX-UHFFFAOYSA-M 0.000 description 1
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 150000001298 alcohols Chemical class 0.000 description 1
- 125000003545 alkoxy group Chemical group 0.000 description 1
- 239000000908 ammonium hydroxide Substances 0.000 description 1
- 229910052786 argon Inorganic materials 0.000 description 1
- ZFSFDELZPURLKD-UHFFFAOYSA-N azanium;hydroxide;hydrate Chemical compound N.O.O ZFSFDELZPURLKD-UHFFFAOYSA-N 0.000 description 1
- -1 but in recent years Chemical compound 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 125000004432 carbon atom Chemical group C* 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 235000019353 potassium silicate Nutrition 0.000 description 1
- 239000010453 quartz Substances 0.000 description 1
- 238000005245 sintering Methods 0.000 description 1
- NTHWMYGWWRZVTN-UHFFFAOYSA-N sodium silicate Chemical compound [Na+].[Na+].[O-][Si]([O-])=O NTHWMYGWWRZVTN-UHFFFAOYSA-N 0.000 description 1
- 238000003980 solgel method Methods 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- 125000005207 tetraalkylammonium group Chemical group 0.000 description 1
- UQMOLLPKNHFRAC-UHFFFAOYSA-N tetrabutyl silicate Chemical compound CCCCO[Si](OCCCC)(OCCCC)OCCCC UQMOLLPKNHFRAC-UHFFFAOYSA-N 0.000 description 1
- HWCKGOZZJDHMNC-UHFFFAOYSA-M tetraethylammonium bromide Chemical compound [Br-].CC[N+](CC)(CC)CC HWCKGOZZJDHMNC-UHFFFAOYSA-M 0.000 description 1
- 229940073455 tetraethylammonium hydroxide Drugs 0.000 description 1
- LRGJRHZIDJQFCL-UHFFFAOYSA-M tetraethylazanium;hydroxide Chemical compound [OH-].CC[N+](CC)(CC)CC LRGJRHZIDJQFCL-UHFFFAOYSA-M 0.000 description 1
- ZQZCOBSUOFHDEE-UHFFFAOYSA-N tetrapropyl silicate Chemical compound CCCO[Si](OCCC)(OCCC)OCCC ZQZCOBSUOFHDEE-UHFFFAOYSA-N 0.000 description 1
- BGQMOFGZRJUORO-UHFFFAOYSA-M tetrapropylammonium bromide Chemical compound [Br-].CCC[N+](CCC)(CCC)CCC BGQMOFGZRJUORO-UHFFFAOYSA-M 0.000 description 1
- FBEVECUEMUUFKM-UHFFFAOYSA-M tetrapropylazanium;chloride Chemical compound [Cl-].CCC[N+](CCC)(CCC)CCC FBEVECUEMUUFKM-UHFFFAOYSA-M 0.000 description 1
Landscapes
- Silicon Compounds (AREA)
- Silicon Polymers (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は、ゾル−ゲル法等によって製造された合成シリ
カ中に含まれるシラノール基を除去し、水分含有量が極
めて少なくて耐熱性に優れた無水シリカを製造するのに
好適な方法に関する。[Detailed Description of the Invention] [Field of Industrial Application] The present invention removes silanol groups contained in synthetic silica produced by a sol-gel method, etc., and produces a synthetic silica with extremely low water content and excellent heat resistance. The present invention relates to a method suitable for producing anhydrous silica.
石英ガラスの原料としては、従来より天然の水晶が用い
られてきたが、近年になってこの石英ガラスが電子部品
等の材料として使用されるようになり、より高純度の石
英ガラスを得る必要から、その原料として高純度の合成
シリカの使用が検討されている（特開昭５１−７７、６
１２号公報、特開昭６１−１８６．２３２号公報等）。Natural quartz has traditionally been used as a raw material for quartz glass, but in recent years, quartz glass has come to be used as a material for electronic components, and the need to obtain quartz glass of higher purity has led to the use of quartz glass. , the use of high-purity synthetic silica as a raw material is being considered (Japanese Patent Application Laid-Open No. 1977-77, 6).
12, JP-A-61-186.232, etc.).
しかしながら、一般的に、合成的に製造されたシリカは
、その製造条件により数人から数十穴程度の細孔径を有
し、加熱により脱水が始まり、さらに１，１００℃から
１，３００℃で数時間焼成すると封孔し、この封孔する
までの焼成過程で吸着水や凝縮水が脱離し、また、シラ
ノール基の縮合反応等により脱水が起こる。しかしなが
ら、シリカ内部に孤立したシラノール基は、この焼成過
程で縮合反応を起こすことができず、水分として内部に
残留したまま封孔されてしまう。そして、このようにシ
ラノール基が残留したままのシリカを石英ガラスの原料
として使用すると、優れた耐熱性を有する石英ガラスが
得られないという問題が生じる。However, synthetically produced silica generally has pore diameters ranging from a few to several tens of holes depending on its manufacturing conditions, and dehydration begins when heated, and further at 1,100°C to 1,300°C. After firing for several hours, the pores are sealed, and during the firing process until the pores are sealed, adsorbed water and condensed water are released, and dehydration occurs due to condensation reactions of silanol groups, etc. However, the silanol groups isolated inside the silica cannot undergo a condensation reaction during this firing process, and remain inside as moisture and are sealed. If silica with residual silanol groups is used as a raw material for quartz glass, a problem arises in that silica glass with excellent heat resistance cannot be obtained.
そこで、このシラノール基を除去する方法として、シリ
カゲルをハロゲン系の脱ＯＨ基剤とキャリヤーガスとの
混合ガス気流中で焼成し、シラノール基をハロゲン原子
に置換する反応を利用して除去する方法が知られている
（特開昭６１−１８６．２３２号公報）が、この方法に
おいても、シラノール基に代わってハロゲン基が残留す
ることになり、石英ガラスにしたときに残留ハロゲンに
起因する耐熱性の低下や腐食性等の問題が生じる。Therefore, as a method for removing these silanol groups, silica gel is baked in a mixed gas flow of a halogen-based OH deOH base and a carrier gas, and the silanol groups are removed using a reaction that replaces the silanol groups with halogen atoms. However, even in this method, halogen groups remain in place of silanol groups, and when silica glass is made, the heat resistance due to the residual halogens is reduced. This causes problems such as a decrease in carbon and corrosive properties.
そこで、本発明者らは、これらの問題を解決するために
鋭意研究を重ねた結果、細孔径と細孔容積とが共に充分
大きいシラノール基を有するシリカ、特に好適には細孔
径や細孔容積が充分大きいシリカを水素気流中で焼成す
ることにより、シリカ中に孤立したシラノール基を水素
との反応により除去できることを見出し、本発明を完成
するに到った。Therefore, as a result of extensive research to solve these problems, the present inventors have found that silica having a silanol group with sufficiently large pore diameter and pore volume, particularly preferably It has been discovered that by firing silica having a sufficiently large silica in a hydrogen stream, isolated silanol groups in the silica can be removed by reaction with hydrogen, and the present invention has been completed.
従って、本発明の目的は、シリカ中のシラノール基を可
及的に除去し、石英ガラスの製造原料として好適な水分
含有量の少ないシリカを得る方法を提供することにある
。Therefore, an object of the present invention is to provide a method for removing silanol groups in silica as much as possible to obtain silica with a low water content suitable as a raw material for producing quartz glass.
すなわち、本発明は、基本的にはシラノール基を有する
シリカを水素気流中で１，１００℃以上の温度で焼成す
る無水シリカの製造方法である。That is, the present invention is basically a method for producing anhydrous silica in which silica having a silanol group is calcined in a hydrogen stream at a temperature of 1,100° C. or higher.
なお、本発明において、シリカ中のシラノール基は、シ
リカ中に含まれる水分とみなされる。Note that in the present invention, silanol groups in silica are considered to be water contained in silica.
本発明方法においては、シリカ表面の細孔径が５０Å以
上、好ましくは６０Å以上であり、また、その細孔容積
が１．０ｍ／／ｇ以上、好ましくは１゜１０Ｊ／ｇ以上
であるのがよく、より好ましくはこれら細孔径と細孔容
積とが共に充分に大きいことが望ましい。細孔径が５０
人に満たない場合でも、水素雰囲気中焼成による脱水効
果は認められるが、水素ガスの細孔的拡散の際の抵抗が
大きくてその効果の程度が低く、また、細孔径が大きく
ても細孔容積の小さいものは、シリカ粒子内部まで水素
が供給され難くなり、それだけ効果の発現が少なくなる
傾向がある。In the method of the present invention, the pore diameter of the silica surface is preferably 50 Å or more, preferably 60 Å or more, and the pore volume is preferably 1.0 m//g or more, preferably 1°10 J/g or more. More preferably, both the pore diameter and the pore volume are sufficiently large. Pore diameter is 50
Although the dehydration effect of firing in a hydrogen atmosphere can be observed even in cases where the size of the pores is smaller than that of humans, the degree of the effect is low because the resistance during pore diffusion of hydrogen gas is large, and even if the pore size is large, the pore size If the volume is small, it becomes difficult for hydrogen to be supplied to the inside of the silica particles, and the effect tends to be reduced accordingly.
本発明において、焼成するシリカは、シラノール基を有
するものであれば特に限定されるものではないが、具体
的には水ガラス等から得られるシリカゲルやアルコキシ
シラン類を加水分解して得られるシリカ等を挙げること
ができる。特に、高純度のシリカを得るためには、アル
コキシシラン類を水、アンモニア及び必要に応じて添加
されるアルコールの混合溶液中で加水分解することによ
って製造するのがよい。ここで、この様な高純度のシリ
カを製造するのに使用できるアルコキシシラン類として
は、例えばテトラメトキシシラン、テトラエトキシシラ
ン、テトラプロポキシシラン、テトラブトキシシラン等
を挙げることができ、アルコキシシラン類であれば特に
限定されないが、好ましくは炭素数１〜４のアルコキシ
基を有するものであり、特に加水分解反応速度の大きい
テトラメトキシシランやテトラエトキシシランが好まし
い。また、この方法において使用できるアルコールとし
ては、メタノール、エタノール、プロパツール等を挙げ
ることができる。In the present invention, the silica to be fired is not particularly limited as long as it has a silanol group, but specific examples include silica gel obtained from water glass, silica obtained by hydrolyzing alkoxysilanes, etc. can be mentioned. In particular, in order to obtain high-purity silica, it is preferable to produce it by hydrolyzing alkoxysilanes in a mixed solution of water, ammonia, and optionally added alcohol. Here, examples of alkoxysilanes that can be used to produce such high-purity silica include tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, and tetrabutoxysilane. Although not particularly limited, it preferably has an alkoxy group having 1 to 4 carbon atoms, and tetramethoxysilane and tetraethoxysilane, which have a high hydrolysis reaction rate, are particularly preferred. Moreover, examples of alcohols that can be used in this method include methanol, ethanol, propatool, and the like.
アルコキシシラン類の加水分解は、水とアンモニアの混
合溶液あるいはこれらに必要に応じて添加されるアルコ
ールを加えた混合溶液を使用して行われ、アルコキシシ
ラン類がアンモニアの存在下で水と接触することにより
起こる。このとき、水酸化テトラアルキルアンモニウム
、又は必要に応じて水酸化テトラアルキルアンモニウム
と併せてテトラアルキルアンモニウム塩を添加すること
が好ましい。水酸化テトラアルキルアンモニウムを添加
することにより充分に細孔径及び細孔容積の大きく、比
表面積の大きな多孔質シリカを得ることができ、さらに
テトラアルキルアンモニウム塩を併用することによりそ
の効果が増大し、目的によっては二元細孔構造を有する
多孔質シリカを得るーとが可能となる。ここで、用いら
れる水酸化テトラアルキルアンモニウムとしては、例え
ば水酸化テトラメチルアンモニウム、水酸化テトラエチ
ルアンモニウム、水酸化テトラプロピルアンモニウム等
がある。また、上記水酸化テトラアルキルアンモニウム
類と併用して用いることができるテトラアルキルアンモ
ニウム塩類としては、例えば臭化テトラエチルアンモニ
ウム、塩化テトラプロピルアンモニウム、臭化テトラプ
ロピルアンモニウム等がある。Hydrolysis of alkoxysilanes is carried out using a mixed solution of water and ammonia, or a mixed solution containing alcohol added as necessary, and the alkoxysilanes are brought into contact with water in the presence of ammonia. It happens due to things. At this time, it is preferable to add tetraalkylammonium hydroxide or, if necessary, a tetraalkylammonium salt together with tetraalkylammonium hydroxide. By adding tetraalkylammonium hydroxide, porous silica with a sufficiently large pore diameter and pore volume and a large specific surface area can be obtained, and the effect is increased by using a tetraalkylammonium salt in combination. Depending on the purpose, it is possible to obtain porous silica having a binary pore structure. Examples of the tetraalkylammonium hydroxide used here include tetramethylammonium hydroxide, tetraethylammonium hydroxide, and tetrapropylammonium hydroxide. Examples of the tetraalkylammonium salts that can be used in combination with the above-mentioned tetraalkylammonium hydroxides include tetraethylammonium bromide, tetrapropylammonium chloride, and tetrapropylammonium bromide.
具体的な製造方法としては、例えば、テトラアルコキシ
シラン１モルに対して水を１〜２０モル、必要に応じて
添加されるアルコールを０〜１０モル及び水酸化テトラ
アルキルアンモニウムを１×１０−４〜ｌＸｌ０−’モ
ルの範囲で混合し、さらにテトラアルキルアンモニウム
塩を併用する場合はｌＸｌ０−５〜１×ｌ０−２モルの
範囲で混合し、得られた混合溶液を十分に攪拌しながら
この混合溶液中に上記テトラアルコキシシランを滴下す
る方法がある。このときの反応温度は必要に応じて適当
な温度を選択することができるが、常温でも十分可能で
ある。ゲル化が終了した後、アルコール及び水を除去す
るため、乾燥又は焼成を行う。As a specific manufacturing method, for example, 1 to 20 moles of water, 0 to 10 moles of alcohol added as necessary, and 1 x 10-4 tetraalkylammonium hydroxide to 1 mole of tetraalkoxysilane. - lXl0-' moles, and if a tetraalkylammonium salt is used in combination, mix in lXl0-5 to lxl0-2 moles, and stir the resulting mixed solution thoroughly. There is a method of dropping the above tetraalkoxysilane into a solution. The reaction temperature at this time can be selected as appropriate depending on the need, but room temperature is also sufficient. After gelation is completed, drying or baking is performed to remove alcohol and water.
この様な方法で得られた多孔質シリカを焼成して無水シ
リカとする場合、大気中で焼成しても比較的水分含有量
の少ないシリカを得ることが可能であるが、水素気流中
で焼成することにより、極めて水分含有量の少ないシリ
カを得ることができる。このときの焼成温度は、１，１
００〜１，３００℃の範囲が好ましく、この範囲より低
いと脱水に時間がかかり、高いとシリカが融解して好ま
しくない。また、焼成は細孔が封孔するまで数時間〜数
十時間行う。When porous silica obtained by such a method is fired to produce anhydrous silica, it is possible to obtain silica with relatively low water content even if fired in the air, but it is possible to obtain silica with a relatively low water content by firing in the atmosphere. By doing so, silica with extremely low water content can be obtained. The firing temperature at this time was 1,1
The temperature is preferably in the range of 00 to 1,300°C. If the temperature is lower than this range, it will take a long time to dehydrate, and if it is higher than this range, the silica will melt, which is not preferred. Further, the firing is performed for several hours to several tens of hours until the pores are sealed.
本発明方法においては、合成シリカを水素気流中で焼成
する際に、その雰囲気の気流として水素と水素及びシラ
ノール基に対して不活性な窒素やアルゴン等のキャリヤ
ーガスとの混合ガスを用いることもできる。In the method of the present invention, when synthetic silica is fired in a hydrogen stream, a mixed gas of hydrogen and a carrier gas such as nitrogen or argon that is inert to hydrogen and silanol groups may be used as the gas stream. can.
本発明においては、シリカを水素気流中で焼成するので
、水素がシリカ細孔内に供給され、この水素がシリカ中
に孤立したシラノール基と反応して水を生成し、この水
は水蒸気となって細孔より容易に排気され、この結果と
してシリカ中に含まれるシラノール基が可及的に除去さ
れるものと考えられる。このとき、シリカ表面における
細孔径や細孔容積が共に充分に大きければ、水素ガスの
細孔的拡散の際の抵抗がより小さくなり、効果の発現が
より一層顕著になるものと考えられる。In the present invention, since silica is fired in a hydrogen stream, hydrogen is supplied into the silica pores, and this hydrogen reacts with isolated silanol groups in the silica to generate water, which turns into water vapor. It is thought that the silica is easily exhausted through the pores, and as a result, the silanol groups contained in the silica are removed as much as possible. At this time, if both the pore diameter and pore volume on the silica surface are sufficiently large, the resistance during pore diffusion of hydrogen gas will be smaller, and the effect will be more pronounced.
さらに、水素とシラノール基の反応による脱水反応は高
温になるほど有利であり、高温ではシリカのシンタリン
グにより細孔の消滅すなわち封孔が起こるが、封孔は細
孔径が小さいものほど起こりやすく、より低温で起こる
。すなわち、細孔径が５０人未満では脱水反応が完了す
る以前に封孔が起こることがあるが、５０Å以上では封
孔以前の温度域で充分な脱水反応が起こると考えられる
〔実施例〕
以下、実施例及び比較例に基づいて、本発明を具体的に
説明する。Furthermore, the dehydration reaction caused by the reaction between hydrogen and silanol groups is more advantageous at higher temperatures.At high temperatures, sintering of silica causes pores to disappear, or seal, but sealing occurs more easily as the pore size becomes smaller. Occurs at low temperatures. That is, if the pore diameter is less than 50 Å, sealing may occur before the dehydration reaction is completed, but if it is 50 Å or more, sufficient dehydration reaction will occur in the temperature range before pore sealing [Example] Below, The present invention will be specifically explained based on Examples and Comparative Examples.
実施例１
テトラメトキシシラン、水、メタノール及び水酸化アン
モニウムを第１表に示す割合で使用し、５０℃でゲル化
させ、得られたゲルを２００°Ｃで減圧下に充分乾燥さ
せた後、７００℃で４時間大気中でか焼を行った。得ら
れた焼成物を粉砕し、分級して粒度１００〜３００趨に
調整した。得られたシリカはその細孔径が５２人であり
、また、その細孔容積が１．１０ｄ／ｇの多孔質シリカ
であった。Example 1 Tetramethoxysilane, water, methanol, and ammonium hydroxide were used in the proportions shown in Table 1, gelatinized at 50°C, and the resulting gel was sufficiently dried at 200°C under reduced pressure. Calcination was carried out in air at 700° C. for 4 hours. The obtained baked product was crushed and classified to adjust the particle size to a range of 100 to 300. The obtained silica was porous silica with a pore diameter of 52 mm and a pore volume of 1.10 d/g.
次に、この多孔質シリカを３ｇ秤量してアルミナボード
に入れ、これを両端をシールした内径５０ ｍｍのアル
ミナ管内にセットし、このアルミナ管内に純度セブンナ
インの水素ガスを４００ ｃｃ／ｍｉｎの速度で流し、
４時間かけて１，２００℃まで昇温し、この温度で４時
間保持した後、自然冷却した。Next, 3g of this porous silica was weighed and put into an alumina board, and this was set in an alumina tube with an inner diameter of 50 mm with both ends sealed, and hydrogen gas with a purity of 79 was fed into the alumina tube at a rate of 400 cc/min. Wash it away,
The temperature was raised to 1,200° C. over 4 hours, maintained at this temperature for 4 hours, and then allowed to cool naturally.
得られたシリカをＦＴ−ＩＲで測定した結果、自由シラ
ノール基の伸縮振動に由来する波数３，６７０ｃｍ’の
面積吸光度が３７ （ａｂｓ／ｇ）であった。これは、
水分含有量が既知の石英ガラスを粉砕して分級し、粒度
１００〜３００趨に調整してＦＴ−ＩＲにより自由シラ
ノール基の面積吸光度を求め、得られた結果と水分含有
量との相関関係から、３１ｐｐｍの水分含有量に相当す
る。As a result of measuring the obtained silica by FT-IR, the area absorbance at a wave number of 3,670 cm' derived from the stretching vibration of free silanol groups was 37 (abs/g). this is,
Quartz glass with a known water content is crushed and classified, the particle size is adjusted to a range of 100 to 300, and the area absorbance of free silanol groups is determined by FT-IR. Based on the correlation between the obtained results and the water content. , corresponding to a water content of 31 ppm.
実施例２
テトラメトキシシラン、水、メタノール及び水酸化テト
ラプロピルアンモニウムを第１表に示ス割合で使用し、
室温でゲル化させ、得られたゲルを実施例１と同様に処
理した。得られたシリカの細孔径は９８人であり、また
、その細孔容積は１゜４８ｄ／ｇであった。Example 2 Tetramethoxysilane, water, methanol and tetrapropylammonium hydroxide were used in the proportions shown in Table 1,
The gel was allowed to gel at room temperature, and the resulting gel was treated in the same manner as in Example 1. The pore diameter of the obtained silica was 98 pores, and the pore volume was 1°48 d/g.
この多孔質シリカを実施例１と同様の方法及び条件で水
素気流中で焼成し、自由シラノール基の面積吸光度を測
定した結果、水分含有量は２７ｐｐｍであった。This porous silica was calcined in a hydrogen stream using the same method and conditions as in Example 1, and the area absorbance of the free silanol groups was measured. As a result, the water content was 27 ppm.
実施例３
テトラメトキシシラン、水及びメタノールを第１表に示
す割合で使用し、５０℃でゲル化させ、得られたゲルを
実施例１と同様に処理した。得られたシリカの細孔径は
１０人であり、また、その細孔容積は０．１５ｄ／ｇで
あった。Example 3 Tetramethoxysilane, water and methanol were used in the proportions shown in Table 1, and gelation was carried out at 50° C., and the resulting gel was treated in the same manner as in Example 1. The pore diameter of the obtained silica was 10, and the pore volume was 0.15 d/g.
■
この多孔質シリカを実施例１と同様の条件で水素気流中
で焼成し、自由シラノール基の面積吸光度を測定した結
果、水分含有量は３２０ ｐｐｍであった。(2) This porous silica was calcined in a hydrogen stream under the same conditions as in Example 1, and the area absorbance of free silanol groups was measured, and the moisture content was found to be 320 ppm.
比較例１
実施例１と同様にして得られた多孔質シリカを３ｇ秤量
してアルミナボードに入れ、これを両端をシールしてい
ない内径５０ｍｍのアルミナ管内にセットし、大気雰囲
気中で４時間かけて１，２００℃まで昇温し、この温度
で４時間保持した後、自然冷却した。Comparative Example 1 Weighed 3 g of porous silica obtained in the same manner as in Example 1, put it in an alumina board, set it in an alumina tube with an inner diameter of 50 mm that did not seal both ends, and heated it in the air for 4 hours. The temperature was raised to 1,200° C., maintained at this temperature for 4 hours, and then allowed to cool naturally.
得られたシリカについて、実施例１と同様にその自由シ
ラノール基の面積吸光度を測定した結果、水分含有量は
８４３ ｐｐｍであった。Regarding the obtained silica, the area absorbance of free silanol groups was measured in the same manner as in Example 1, and the water content was found to be 843 ppm.
比較例２
実施例３と同様にして得られた多孔質シリカを比較例１
と同様にして大気中で焼成し、実施例１と同様にその自
由シラノール基の面積吸光度を測定した結果、水分含有
量は８７６ ｐｐｍであった。Comparative Example 2 Porous silica obtained in the same manner as in Example 3 was used in Comparative Example 1.
The product was fired in the air in the same manner as in Example 1, and the area absorbance of the free silanol groups was measured in the same manner as in Example 1. As a result, the water content was 876 ppm.
−ｌ ２ 一
実施例４〜７
テトラメトキシシラン１モル、水、メタノール、水酸化
テトラアルキルアンモニウム及び臭化テトラアルキルア
ンモニウムを第２表に示す割合で使用し、室温でゲル化
させ、得られたゲルを２００℃で減圧下に充分に乾燥し
、多孔質シリカを得た。-l 2 Examples 4 to 7 1 mol of tetramethoxysilane, water, methanol, tetraalkylammonium hydroxide, and tetraalkylammonium bromide were used in the proportions shown in Table 2, and gelation was performed at room temperature. The gel was sufficiently dried at 200° C. under reduced pressure to obtain porous silica.
得られた多孔質シリカの細孔径と細孔容積及び比表面積
を窒素吸着法により調べた。結果を第２表に示す。なお
、実施例４においては２５０人と１２人に、実施例５に
おいては１９３人と１２人にそれぞれ細孔径のピークを
有する二元細孔構造であることが確認された。The pore diameter, pore volume, and specific surface area of the obtained porous silica were investigated by nitrogen adsorption method. The results are shown in Table 2. In addition, it was confirmed that in Example 4, 250 people and 12 people had a binary pore structure, and in Example 5, 193 people and 12 people had a peak in pore diameter.
第
２
表
中及び水素雰囲気中で１，２００℃で４時間焼成し、得
られたシリカ中の水分含有量を実施例１と同様にして測
定した。結果を第３表に示す。The silica in Table 2 was calcined at 1,200° C. for 4 hours in a hydrogen atmosphere, and the water content in the obtained silica was measured in the same manner as in Example 1. The results are shown in Table 3.
第 ３ 表
実施例８〜１３
テトラメトキシシラン１モル、水及びメタノールを第４
表に示す割合で使用し、ゲル化させて得られたゲルを実
施例４〜７と同様に処理した。得られた多孔質シリカの
細孔径と細孔容積及び比表面積を窒素吸着法により調べ
た。結果を第４表に示す。Table 3 Examples 8-13 1 mole of tetramethoxysilane, water and methanol were added to the fourth
The gels obtained by gelling were used in the proportions shown in the table and were treated in the same manner as in Examples 4 to 7. The pore diameter, pore volume, and specific surface area of the obtained porous silica were investigated by nitrogen adsorption method. The results are shown in Table 4.
次いで、実施例４〜７と同様にして焼成し、水分含有量
を測定した。結果を第５表に示す。Next, it was fired in the same manner as in Examples 4 to 7, and the water content was measured. The results are shown in Table 5.
第
表
〔発明の効果〕
本発明方法によれば、シリカ中の水分含有量を低減でき
るので、このシリカを原料として使用することにより耐
熱性や光学特性に優れた性能を有する石英ガラスを製造
することができる。Table [Effects of the Invention] According to the method of the present invention, the water content in silica can be reduced, and by using this silica as a raw material, silica glass with excellent heat resistance and optical properties can be manufactured. be able to.
Claims (3)
１００℃以上の温度で焼成することを特徴とする無水シ
リカの製造方法。(1) Silica having a silanol group is 1,
A method for producing anhydrous silica, which comprises firing at a temperature of 100°C or higher.
１．０ｍｌ／ｇ以上の細孔容積を有する請求項１記載の
無水シリカの製造方法。(2) the silica has an average pore diameter of 50 Å or more, and
The method for producing anhydrous silica according to claim 1, which has a pore volume of 1.0 ml/g or more.
得られたシリカであって、加水分解時に水酸化テトラア
ルキルアンモニウム、又は水酸化テトラアルキルアンモ
ニウム及びテトラアルキルアンモニウム塩を添加する請
求項１記載の無水シリカの製造方法。(3) Anhydrous according to claim 1, wherein the silica is silica obtained by hydrolyzing tetraalkoxysilane, and tetraalkylammonium hydroxide, or tetraalkylammonium hydroxide and tetraalkylammonium salt are added at the time of hydrolysis. Method for producing silica.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2020393A JPH03228817A (en) | 1990-02-01 | 1990-02-01 | Production of anhydrous silica |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2020393A JPH03228817A (en) | 1990-02-01 | 1990-02-01 | Production of anhydrous silica |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH03228817A true JPH03228817A (en) | 1991-10-09 |
Family
ID=12025775
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2020393A Pending JPH03228817A (en) | 1990-02-01 | 1990-02-01 | Production of anhydrous silica |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH03228817A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0801026A4 (en) * | 1994-12-26 | 1997-11-19 | ||
| JP2008201833A (en) * | 2007-02-16 | 2008-09-04 | Shin Etsu Chem Co Ltd | Compositions for forming film, insulating film having low dielectric constant, method for forming insulating film having low dielectric constant and semiconductor apparatus |
-
1990
- 1990-02-01 JP JP2020393A patent/JPH03228817A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0801026A4 (en) * | 1994-12-26 | 1997-11-19 | ||
| JP2008201833A (en) * | 2007-02-16 | 2008-09-04 | Shin Etsu Chem Co Ltd | Compositions for forming film, insulating film having low dielectric constant, method for forming insulating film having low dielectric constant and semiconductor apparatus |
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