JPH08231213A - Production of transparent porous body having water repellency - Google Patents
Production of transparent porous body having water repellencyInfo
- Publication number
- JPH08231213A JPH08231213A JP7065192A JP6519295A JPH08231213A JP H08231213 A JPH08231213 A JP H08231213A JP 7065192 A JP7065192 A JP 7065192A JP 6519295 A JP6519295 A JP 6519295A JP H08231213 A JPH08231213 A JP H08231213A
- Authority
- JP
- Japan
- Prior art keywords
- alkoxysilane
- porous body
- water
- water repellency
- silica
- 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
Classifications
-
- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
- C03B19/00—Other methods of shaping glass
- C03B19/12—Other methods of shaping glass by liquid-phase reaction processes
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Manufacturing & Machinery (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- Glass Compositions (AREA)
- Silicon Compounds (AREA)
- Silicon Polymers (AREA)
- Glass Melting And Manufacturing (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、撥水性を有する透光性
多孔体の製造方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a translucent porous body having water repellency.
【０００２】[0002]
【従来の技術】従来、透光性多孔体の製造方法として、
テトラメトキシシラン、テトラエトキシシラン等の４官
能アルコキシシランを加水分解し縮重合して得たシリカ
アルコゲルを超臨界乾燥することにより、軽量の透光性
多孔体が得られることは知られている。ここで、超臨界
乾燥を行う媒体として、エタノール、メタノール、二酸
化炭素等が用いられるが、二酸化炭素を用いた場合、臨
界温度、臨界圧力ともエタノール、メタノールよりも緩
やかな条件で行うことができ有利な方法である。しかし
ながら、かかる媒体を用いて製造した多孔体は、吸水性
が高く、水に浸漬した場合、吸水が生じることが問題と
なっていた。2. Description of the Related Art Conventionally, as a method for producing a translucent porous body,
It is known that a lightweight translucent porous body can be obtained by supercritically drying a silica alcogel obtained by hydrolyzing and polycondensing a tetrafunctional alkoxysilane such as tetramethoxysilane and tetraethoxysilane. . Here, ethanol, methanol, carbon dioxide or the like is used as a medium for performing supercritical drying, but when carbon dioxide is used, both the critical temperature and the critical pressure can be performed under milder conditions than ethanol and methanol, which is advantageous. That's the method. However, the porous body produced by using such a medium has a high water absorbing property, and when immersed in water, it has been a problem that water absorbing occurs.
【０００３】これに対応するものとして、特開平３−２
５７０２７号公報には、出発原料として、２官能または
３官能アルコキシシラン、或いは２官能または３官能ア
ルコキシシランと４官能アルコキシシランを用い、これ
らを加水分解し縮重合して得たシリカアルコゲルを超臨
界乾燥することにより、２０℃、湿度４０〜５０％の条
件下において、透明性の経時変化の少ない多孔体を得ら
れることが開示されている。As a means for dealing with this, Japanese Patent Laid-Open No. 3-2
JP-A-57027 discloses a silica alcogel obtained by hydrolyzing and polycondensing a bifunctional or trifunctional alkoxysilane, or a bifunctional or trifunctional alkoxysilane and a tetrafunctional alkoxysilane as starting materials. It is disclosed that by performing critical drying, it is possible to obtain a porous body with a small change in transparency over time under the conditions of 20 ° C. and a humidity of 40 to 50%.
【０００４】[0004]
【発明が解決しようとする課題】しかしながら、かかる
方法で得られた多孔体の評価が、２０℃、湿度４０〜５
０％の緩やかな条件下でなされたものであり、撥水性の
評価は不明である。また出発原料として２官能または３
官能アルコキシシランを用いる場合、透明性が十分でな
い。出発原料として２官能または３官能アルコキシシラ
ンと４官能アルコキシシランを用いる場合、各原料の反
応性が大きく異なるため得られる多孔体にクラックを生
じやすい等の問題があった。However, the evaluation of the porous body obtained by such a method was conducted at 20 ° C. and a humidity of 40-5.
It was performed under a mild condition of 0%, and the evaluation of water repellency is unknown. Also, as a starting material, bifunctional or trifunctional
When using a functional alkoxysilane, the transparency is not sufficient. When a bifunctional or trifunctional alkoxysilane and a tetrafunctional alkoxysilane are used as starting materials, there is a problem that cracks are likely to occur in the obtained porous body because the reactivity of the respective materials is greatly different.
【０００５】このように、シリカアルコゲルの超臨界乾
燥を行う媒体として二酸化炭素を用いた場合、臨界温度
や臨界圧力ともエタノール、メタノールよりも緩やかな
条件下で行うことができ有利な方法であるが、かかる媒
体を用いて製造した多孔体は、吸水性が大であり、水に
浸漬した場合吸水が生じ破壊に至ること、或いは多湿条
件下において吸湿が生じ、性能（熱伝導率や透光性）の
劣化が起こり易いことが問題となっていた。Thus, when carbon dioxide is used as a medium for supercritical drying of silica alcogel, it is an advantageous method because it can be carried out under conditions more gentle than those of ethanol and methanol for both critical temperature and critical pressure. However, a porous body produced by using such a medium has a large water absorption property, and when it is immersed in water, water absorption causes water absorption and destruction, or moisture absorption occurs under high humidity conditions, resulting in performance (heat conductivity and light transmission). It has been a problem that deterioration of property) is likely to occur.
【０００６】そこで、本発明は、シリカアルコゲルの超
臨界乾燥を行う媒体として二酸化炭素を用いた場合で
も、耐水性、耐湿性に優れ、水分の影響による性能の劣
化をきたさない透光性多孔体を得ることのできる、撥水
性を有する透光性多孔体の製造方法を提供することを目
的とする。Therefore, the present invention provides a light-transmitting porous material which is excellent in water resistance and moisture resistance even when carbon dioxide is used as a medium for supercritical drying of silica alcogel and which does not cause deterioration of performance due to the influence of water. It is an object of the present invention to provide a method for producing a translucent porous body having water repellency capable of obtaining a body.
【０００７】[0007]
【課題を解決するための手段】上記の課題を解決するた
めに、本発明の撥水性を有する透光性多孔体の製造方法
は、４官能アルコキシシランを溶媒中にて加水分解し縮
重合して得たシリカアルコゲルを、３官能アルコキシシ
ランまたは２官能アルコキシシラン中にて浸漬処理した
後、二酸化炭素を用いて超臨界乾燥すること、を特徴と
している。In order to solve the above-mentioned problems, the method for producing a translucent porous body having water repellency according to the present invention is a method in which a tetrafunctional alkoxysilane is hydrolyzed in a solvent to perform polycondensation. The silica alcogel thus obtained is characterized by being soaked in a trifunctional alkoxysilane or a bifunctional alkoxysilane and then supercritically dried using carbon dioxide.
【０００８】本発明の好ましい態様において、３官能ア
ルコキシシランまたは２官能アルコキシシラン中でのシ
リカアルコゲルの浸漬温度を１０〜７０℃とすることが
できる。また、本発明の好ましい他の態様において、シ
リカアルコゲルをアセトン溶媒中にて得るようにするこ
とができる。In a preferred embodiment of the present invention, the dipping temperature of the silica alcogel in the trifunctional alkoxysilane or the bifunctional alkoxysilane can be 10 to 70 ° C. In another preferred embodiment of the present invention, the silica alcogel can be obtained in an acetone solvent.
【０００９】発明の具体的説明 本発明において、シリカアルコゲル製造の出発原料とし
て、４官能アルコキシシランを用いる。このように出発
原料として同種のものを用いることにより、反応性が均
一で、クラックの発生し難い透光性多孔体を得ることが
できる。４官能アルコキシシランとしては、テトラメト
キシシラン、テトラエトキシシラン等の１種または２種
以上の混合物が挙げられるが、反応の均一性の点から単
一物が好ましい。ここで、４官能アルコキシシランと
は、モノマーだけでなく、２〜８量体程度のオリゴマー
の１種または２種以上の混合物、或いはこれらとモノマ
ーとの混合物をも含む。かかる４官能アルコキシシラン
に水、溶媒及び触媒を加え、混合し、アルコキシシラン
を加水分解し、縮重合してシリカアルコゲルを得る。こ
こで溶媒としては、エタノール、メタノール、アセトン
等が挙げられるが、アセトンが好ましい。エアロゲルの
作製は、先ずアルコゲルを作製し、ゲル内部を溶媒で置
換し、さらに液体二酸化炭素で置換した後、二酸化炭素
による超臨界乾燥を行って作製する。ここで、溶媒置換
の際の溶媒として液体二酸化炭素と相溶性の良好なアセ
トンを用いるのが好ましく、従って、アルコゲル作製の
際にアセトンを溶媒として用いれば、溶媒置換が簡単
で、処理時間の短縮が可能となる。また、触媒として
は、アンモニア、フッ化アンモニウム、ピペリジン等の
アルカリ触媒が挙げられる。[0009] In a specific description of the invention The invention, as the starting material silica Arco gel preparation, using tetrafunctional alkoxysilane. Thus, by using the same kind of starting material, it is possible to obtain a translucent porous body having uniform reactivity and less likely to cause cracks. Examples of the tetrafunctional alkoxysilane include one kind or a mixture of two or more kinds such as tetramethoxysilane and tetraethoxysilane, and a single substance is preferable from the viewpoint of reaction uniformity. Here, the tetrafunctional alkoxysilane includes not only a monomer, but also one or a mixture of two or more oligomers of about 2 to 8 mer, or a mixture of these and a monomer. Water, a solvent and a catalyst are added to and mixed with the tetrafunctional alkoxysilane, and the alkoxysilane is hydrolyzed and polycondensed to obtain a silica alcogel. Here, examples of the solvent include ethanol, methanol, and acetone, and acetone is preferable. The aerogel is produced by first producing an alcogel, substituting the inside of the gel with a solvent, further substituting with liquid carbon dioxide, and then performing supercritical drying with carbon dioxide. Here, it is preferable to use acetone, which has a good compatibility with liquid carbon dioxide, as the solvent for solvent replacement, and therefore, if acetone is used as the solvent for the alcogel preparation, solvent replacement is easy and the treatment time is shortened. Is possible. Further, examples of the catalyst include alkali catalysts such as ammonia, ammonium fluoride and piperidine.
【００１０】このようにして得たシリカアルコゲルを３
官能アルコキシシランまたは２官能アルコキシシラン中
にて一定時間浸漬処理する。かかる浸漬処理により撥水
性が付与され、その後の二酸化炭素による超臨界乾燥に
よって撥水性を有する透光性多孔体を得ることができ
る。ここで、３官能アルコキシシランとしては、メチル
トリエトキシシラン、メチルトリメトキシシラン、エチ
ルトリエトキシシラン、エチルトリメトキシシラン等が
挙げられる。また、２官能アルコキシシランとしてはジ
メチルジエトキシシラン、ジメチルジメトキシシラン、
ジエチルジエトキシシラン、ジエチルジメトキシシラン
等が挙げられる。なお、本発明において、３官能アルコ
キシシランまたは２官能アルコキシシランとは、モノマ
ーだけでなく、２〜８量体程度のオリゴマーの１種また
は２種以上の混合物、或いはこれらとモノマーとの混合
物をも含む。The silica alcogel thus obtained was mixed with 3
Immersion treatment is carried out for a certain period of time in a functional alkoxysilane or a bifunctional alkoxysilane. Water repellency is imparted by such an immersion treatment, and then, supercritical drying with carbon dioxide makes it possible to obtain a translucent porous body having water repellency. Here, examples of the trifunctional alkoxysilane include methyltriethoxysilane, methyltrimethoxysilane, ethyltriethoxysilane, and ethyltrimethoxysilane. As the bifunctional alkoxysilane, dimethyldiethoxysilane, dimethyldimethoxysilane,
Examples thereof include diethyldiethoxysilane and diethyldimethoxysilane. In the present invention, the term “trifunctional alkoxysilane” or “bifunctional alkoxysilane” means not only a monomer, but also one or a mixture of two or more oligomers of about 2 to 8 monomers, or a mixture of these and a monomer. Including.
【００１１】シリカアルコゲルの３官能アルコキシシラ
ンまたは２官能アルコキシシラン中での浸漬時間は、シ
リカアルコゲルの寸法、浸漬温度等によって異なるが、
１時間〜７日間程度、作業能率等を考慮し好ましくは８
〜１００時間程度である。浸漬時間が１時間未満では充
分に３官能アルコキシシランまたは２官能アルコキシシ
ランがアルコゲル内に拡散されず充分な撥水性が得られ
ない。一方、浸漬時間が７日間以上であると撥水性は充
分に得られるが、得られる多孔体の透明度が低下する。
また、浸漬温度は、１０〜７０℃程度、作業性等を考慮
し好ましくは３０〜５０℃程度である。浸漬温度が１０
℃未満では、充分な撥水性が得られず、７０℃を越える
と３官能アルコキシシランまたは２官能アルコキシシラ
ンの蒸発が大となる。なお、浸漬温度と浸漬時間との関
係は、浸漬温度が高ければ浸漬時間は短時間でよく、低
ければ長時間を要すると考えられるが、シリカアルコゲ
ル作製時の溶媒の種類や浸漬する溶液の種類等によって
異なり、適宜選択する。The immersion time of the silica alcogel in the trifunctional alkoxysilane or the bifunctional alkoxysilane depends on the size of the silica alcogel, the immersion temperature, etc.
1 hour to 7 days, considering work efficiency, etc., preferably 8
It is about 100 hours. When the immersion time is less than 1 hour, the trifunctional alkoxysilane or the bifunctional alkoxysilane is not sufficiently diffused in the alcogel and sufficient water repellency cannot be obtained. On the other hand, when the immersion time is 7 days or more, the water repellency is sufficiently obtained, but the transparency of the obtained porous body is lowered.
The immersion temperature is about 10 to 70 ° C, and preferably about 30 to 50 ° C in consideration of workability and the like. Immersion temperature is 10
If the temperature is lower than 0 ° C, sufficient water repellency cannot be obtained, and if the temperature exceeds 70 ° C, evaporation of the trifunctional alkoxysilane or the bifunctional alkoxysilane becomes large. The relationship between the immersion temperature and the immersion time is such that if the immersion temperature is high, the immersion time may be short, and if it is low, it may take a long time. It depends on the type, etc. and is selected appropriately.
【００１２】また、使用する溶媒、浸漬処理する溶液に
よって、同じ浸漬時間、浸漬温度でも、得られる透光性
多孔体の撥水性が異なる。その傾向を下記の表１に示
す。Further, depending on the solvent used and the solution to be dipped, the water repellency of the obtained light-transmitting porous body varies even with the same dipping time and dipping temperature. The tendency is shown in Table 1 below.
【００１３】[0013]
【表１】 [Table 1]
【００１４】上記のようにしてシリカアルコゲルを浸漬
処理した後、ゲル内部の溶媒置換を行う。次いで、液体
二酸化炭素中に保持してゲル内部の二酸化炭素置換を行
った後、二酸化炭素を超臨界状態にして乾燥する。ここ
で、溶媒置換に用いる溶媒としては、液体二酸化炭素と
相溶性の良好な溶媒、具体的にはアセトンが好ましい。After dipping the silica alcogel as described above, the solvent inside the gel is replaced. Next, after the carbon dioxide inside the gel is replaced by holding it in liquid carbon dioxide, the carbon dioxide is brought into a supercritical state and dried. Here, the solvent used for solvent substitution is preferably a solvent having a good compatibility with liquid carbon dioxide, specifically acetone.
【００１５】[0015]
【作用】４官能アルコキシシランを加水分解し、縮重合
して得たシリカアルコゲルを３官能または２官能アルコ
キシシラン中にて一定時間浸漬処理することにより、撥
水性が付与される。その理由は明らかでないが、例えば
メチルトリメトキシシランを例に説明すると、化１に示
すように、アルコゲル中の親水基であるＳｉＯＨとメチ
ルトリメトキシシランが反応し、結果としてＣＨ3 −Ｓ
ｉという疎水基が存在することにより、撥水性が得られ
るものと考えられる。The water repellency is imparted by subjecting the silica alcogel obtained by hydrolyzing the tetrafunctional alkoxysilane to polycondensation and immersing it in the trifunctional or bifunctional alkoxysilane for a certain period of time. Although the reason for this is not clear, for example, using methyltrimethoxysilane as an example, as shown in Chemical formula 1, SiOH, which is a hydrophilic group in the alcogel, reacts with methyltrimethoxysilane, resulting in CH 3 --S.
It is considered that the water repellency is obtained due to the presence of the hydrophobic group i.
【００１６】[0016]
【化１】 Embedded image
【００１７】[0017]
【実施例】以下の実施例は、本発明をさらに具体的に説
明するためのものである。これらの実施例は本発明を例
示的に示したものであって、本発明を制限するものでは
ない。The following examples serve to explain the present invention more specifically. These examples are illustrative of the invention and are not intended to limit the invention.
【００１８】実施例１ テトラメトキシシランと水をモル比１：４とし、これに
アセトン及び触媒としてピペリジンを混合し、これを円
筒状容器（８０ｍｍφ、高さ１５ｍｍ）に流し込み、常
温で２４時間放置することによりシリカアルコゲルを作
製した。この際、混合比は、モル比でテトラメトキシシ
ラン：水：アセトン：ピペリジン＝１：４：１２：５×
１０-5であった。このシリカアルコゲルを円筒状容器か
ら取り外し、メチルトリメトキシシラン中で４０℃にて
３日間浸漬処理を行った。次いでアセトン中に３日間放
置してゲル内部を溶媒置換した後、７〜１０℃、４０〜
８０気圧の液体二酸化炭素中に２日間保持して二酸化炭
素置換を行った。その間に交換を３回程度行った。次い
で、系内を１００℃、１００気圧にし、超臨界乾燥を１
時間行うことにより、透光性多孔体を得た。 Example 1 Tetramethoxysilane and water having a molar ratio of 1: 4 were mixed with acetone and piperidine as a catalyst, and the mixture was poured into a cylindrical container (80 mmφ, height 15 mm) and left at room temperature for 24 hours. By doing so, a silica alcogel was prepared. At this time, the mixing ratio is a molar ratio of tetramethoxysilane: water: acetone: piperidine = 1: 4: 12: 5 ×.
It was 10 -5 . The silica alcogel was removed from the cylindrical container and immersed in methyltrimethoxysilane at 40 ° C. for 3 days. Then, after leaving the gel in acetone for 3 days to replace the solvent inside the gel,
Carbon dioxide substitution was carried out by holding in liquid carbon dioxide at 80 atm for 2 days. In the meantime, exchange was performed about 3 times. Then, the system is heated to 100 ° C. and 100 atm, and the supercritical drying is performed to 1
By carrying out for a time, a translucent porous body was obtained.
【００１９】この透光性多孔体の熱伝導率を熱伝導率測
定装置（英弘精機株式会社製、ＨＣ−０７２）で測定し
た。熱伝導率は０．０１２１kcal/m・hr・℃であった。
この透光性多孔体を１０日間水面に浮かべたが、水没は
ほとんど見られず、充分な撥水性を示した。また、この
処理後に熱伝導率を測定したが、熱伝導率は０．０１２
２kcal/m・hr・℃で、ほとんど断熱性能の劣化はみられ
なかった。かかる処理前後において、外見上透光性の劣
化も見られなかった。また、得られた透光性多孔体を、
４０℃、湿度９０％の条件下に３０日間放置したとこ
ろ、透光性の劣化は見られなかった。The thermal conductivity of this translucent porous body was measured with a thermal conductivity measuring device (HC-072, manufactured by Eiko Seiki Co., Ltd.). The thermal conductivity was 0.0121 kcal / m · hr · ° C.
When this translucent porous body was floated on the water surface for 10 days, it was hardly submerged and showed sufficient water repellency. Also, the thermal conductivity was measured after this treatment, and the thermal conductivity was 0.012.
At 2 kcal / m · hr · ° C, almost no deterioration of heat insulation performance was observed. Before and after such treatment, no apparent deterioration in translucency was observed. In addition, the obtained translucent porous body,
When left for 30 days under the conditions of 40 ° C. and humidity of 90%, deterioration of translucency was not observed.
【００２０】実施例２ 実施例１において、シリカアルコゲル作製の出発原料と
して、テトラメトキシシランに替えてテトラエトキシシ
ランを用い、浸漬処理溶液として、メチルトリメトキシ
シランに替えてメチルトリエトキシシランを用いた他
は、実施例１と同様に処理して透光性多孔体を得た。 Example 2 In Example 1, tetraethoxysilane was used in place of tetramethoxysilane as a starting material for producing silica alcogel, and methyltriethoxysilane was used in place of methyltrimethoxysilane as the dipping treatment solution. Otherwise, the same treatment as in Example 1 was carried out to obtain a translucent porous body.
【００２１】この透光性多孔体の熱伝導率を実施例１に
おけると同様に測定した。熱伝導率は０．０１３６kcal
/m・hr・℃であった。この透光性多孔体を１０日間水面
に浮かべたが、水没はほとんど見られず、充分な撥水性
を示した。また、この処理後に熱伝導率を測定したが、
熱伝導率は０．０１３９kcal/m・hr・℃で、ほとんど断
熱性能の劣化はみられなかった。かかる処理前後におい
て、外見上透光性の劣化も見られなかった。また、得ら
れた透光性多孔体を、４０℃、湿度９０％の条件下に３
０日間放置したところ、透光性の劣化は見られなかっ
た。The thermal conductivity of this translucent porous body was measured in the same manner as in Example 1. Thermal conductivity is 0.0136kcal
/ m · hr · ° C. When this translucent porous body was floated on the water surface for 10 days, it was hardly submerged and showed sufficient water repellency. Also, the thermal conductivity was measured after this treatment,
The thermal conductivity was 0.0139 kcal / m · hr · ° C, and almost no deterioration in heat insulation performance was observed. Before and after such treatment, no apparent deterioration in translucency was observed. In addition, the obtained translucent porous body was subjected to 3 ° C. under the conditions of 40 ° C. and a humidity of 90%.
When left for 0 days, no deterioration in translucency was observed.
【００２２】比較例１ 実施例１と同様に処理してシリカアルコゲルを得、この
シリカアルコゲルを円筒状容器から取り外し、そのまま
アセトン中に３日間放置してゲル内部を溶媒置換した
後、実施例１と同様に処理して透光性多孔体を得た。 Comparative Example 1 Silica alcogel was obtained by treating in the same manner as in Example 1. The silica alcogel was removed from the cylindrical container and allowed to stand in acetone for 3 days to replace the inside of the gel with a solvent. The same procedure as in Example 1 was carried out to obtain a translucent porous body.
【００２３】この透光性多孔体の熱伝導率を実施例１に
おけると同様に測定した。熱伝導率は０．０１２９kcal
/m・hr・℃であった。この透光性多孔体は、水面に浮か
べると吸水が生じてすぐに水没し、クラックが多数生じ
た。この処理後の熱伝導率の測定は、試料に割れが生じ
たためできなかった。また、得られた透光性多孔体を、
４０℃、湿度９０％の条件下に３０日間放置したとこ
ろ、白濁した。The thermal conductivity of this translucent porous body was measured in the same manner as in Example 1. Thermal conductivity is 0.0129kcal
/ m · hr · ° C. When this translucent porous body was floated on the water surface, it absorbed water and immediately submerged in water, resulting in many cracks. The thermal conductivity after this treatment could not be measured because the sample cracked. In addition, the obtained translucent porous body,
When it was left for 30 days under the conditions of 40 ° C. and humidity of 90%, it became cloudy.
【００２４】以上の実施例及び比較例から明らかなよう
に、撥水処理を行わない未処理品が水面に浮かべた場
合、吸水が生じてすぐ水没するのに対し、本発明の撥水
処理を行って作製した透光性多孔体は、１０日間以上水
面に浮かんでおり、全く水没は見られず、充分な撥水性
を示した。また、４０℃、湿度９０％の条件下におい
て、撥水処理を行わない未処理品が白濁するのに対し、
本発明の撥水処理を行って作製した透光性多孔体は、ほ
とんど変化がみられず、このような高温、多湿条件に対
しても充分な抵抗性を示した。As is clear from the above Examples and Comparative Examples, when an untreated product that has not been subjected to water repellent treatment floats on the water surface, it absorbs water and is immediately submerged, whereas the water repellent treatment of the present invention is applied. The translucent porous body produced by performing the operation floated on the water surface for 10 days or longer, no submersion in water was observed, and sufficient water repellency was exhibited. Further, under the conditions of 40 ° C. and humidity of 90%, the untreated product not subjected to the water repellent treatment becomes cloudy, while
The translucent porous body produced by the water repellent treatment of the present invention showed almost no change and showed sufficient resistance to such high temperature and high humidity conditions.
【００２５】[0025]
【発明の効果】本発明の製造方法によれば、シリカアル
コゲルの超臨界乾燥に先立ち、シリカアルコゲルを撥水
処理するようにしたので、耐水性、耐湿性に優れ、水分
の影響による断熱性能、透光性の劣化のほとんどない透
光性多孔体を得ることができる。According to the production method of the present invention, since the silica alcogel is subjected to the water repellent treatment prior to the supercritical drying of the silica alcogel, it is excellent in water resistance and moisture resistance, and is insulated by the influence of moisture. It is possible to obtain a translucent porous body with almost no deterioration in performance and translucency.
Claims (3)
分解し縮重合して得たシリカアルコゲルを、３官能アル
コキシシランまたは２官能アルコキシシラン中にて浸漬
処理した後、二酸化炭素を用いて超臨界乾燥することを
特徴とする、撥水性を有する透光性多孔体の製造方法。1. A silica alcogel obtained by hydrolyzing and polycondensing a tetrafunctional alkoxysilane in a solvent is immersed in a trifunctional alkoxysilane or a bifunctional alkoxysilane and then treated with carbon dioxide. A method for producing a translucent porous body having water repellency, which comprises performing supercritical drying.
コキシシラン中でのシリカアルコゲルの浸漬温度が１０
〜７０℃である、請求項１に記載の撥水性を有する透光
性多孔体の製造方法。2. The dipping temperature of the silica alcogel in the trifunctional alkoxysilane or the bifunctional alkoxysilane is 10.
The method for producing a light-transmitting porous body having water repellency according to claim 1, wherein the temperature is ˜70 ° C. 3.
る、請求項１または２に記載の撥水性を有する透光性多
孔体の製造方法。3. The method for producing a translucent porous body having water repellency according to claim 1, wherein the silica alcogel is obtained in an acetone solvent.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7065192A JPH08231213A (en) | 1995-02-27 | 1995-02-27 | Production of transparent porous body having water repellency |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7065192A JPH08231213A (en) | 1995-02-27 | 1995-02-27 | Production of transparent porous body having water repellency |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH08231213A true JPH08231213A (en) | 1996-09-10 |
Family
ID=13279819
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP7065192A Pending JPH08231213A (en) | 1995-02-27 | 1995-02-27 | Production of transparent porous body having water repellency |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH08231213A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6855759B2 (en) | 1998-05-18 | 2005-02-15 | Shin-Etsu Chemical Co., Ltd. | Silica particles surface-treated with silane, process for producing the same and uses thereof |
| JP2007238794A (en) * | 2006-03-09 | 2007-09-20 | Matsushita Electric Ind Co Ltd | Silica drying gel |
| JP2008144053A (en) * | 2006-12-11 | 2008-06-26 | Dow Corning Toray Co Ltd | Composite microparticle and method for producing the same |
| JP2009173701A (en) * | 2008-01-22 | 2009-08-06 | National Institute Of Advanced Industrial & Technology | Method for producing organic-inorganic hybrid material and organic-inorganic hybrid material |
| JP2009184853A (en) * | 2008-02-04 | 2009-08-20 | Nippon Chem Ind Co Ltd | Colloidal silica composed of silica particles with fixed piperidine |
-
1995
- 1995-02-27 JP JP7065192A patent/JPH08231213A/en active Pending
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6855759B2 (en) | 1998-05-18 | 2005-02-15 | Shin-Etsu Chemical Co., Ltd. | Silica particles surface-treated with silane, process for producing the same and uses thereof |
| JP2007238794A (en) * | 2006-03-09 | 2007-09-20 | Matsushita Electric Ind Co Ltd | Silica drying gel |
| JP2008144053A (en) * | 2006-12-11 | 2008-06-26 | Dow Corning Toray Co Ltd | Composite microparticle and method for producing the same |
| JP2009173701A (en) * | 2008-01-22 | 2009-08-06 | National Institute Of Advanced Industrial & Technology | Method for producing organic-inorganic hybrid material and organic-inorganic hybrid material |
| JP2009184853A (en) * | 2008-02-04 | 2009-08-20 | Nippon Chem Ind Co Ltd | Colloidal silica composed of silica particles with fixed piperidine |
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