JPH0623070B2 - Method for producing titanic acid porous glass ceramics - Google Patents

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to a porous glass ceramics, in particular, a titanic acid-containing porous glass ceramics having a glass skeleton mainly containing titanic acid and silicic acid (hereinafter referred to as “titanic acid porous glass”). Quality glass ceramics ").

Conventional technology and problems Currently, innumerable pores with diameters of several angstroms to several thousand angstroms are used as those that can be used for adsorbents, catalysts, catalyst carriers, gas sensors, ultrafiltration media, immobilized oxygen carriers, etc. A porous glass provided with this is proposed. Such porous glass is generally made of oxide glass, and S
iO ₂ -B ₂ O ₃ those made from -Na ₂ O composition _{system, SiO 2 -B 2 O 3 -Na} 2 O 3 -CaO-MgO
Those produced from the composition system and _{Na 2 O-P 2 O 5} -S
Those produced from iO ₂ have already been reported and put to practical use. Most of these porous glasses are highly silicic and are used in the production of highly silicic glasses such as Vycor glass. Such _{SiO 2 -B 2 O 3 -Na 2} O composition _{system, SiO 2 -B 2 O 3 -Na} 2 O-Al 2 O 3 -Ca
Porous glass produced from O-MgO composition system and _{Na 2 O-P 2 O 5} -SiO 2 composition system has features that can be controlled by adjusting the heat treatment conditions of phase separation upon the size of the pores ing.

However, the _{SiO 2 -B 2 O 3 -Na 2} O composition _{system, SiO 2 -B 2 O 3 -Na} 2 O-Al 2 O 3 -Ca
When a porous glass is produced from the O—MgO composition system and the Na ₂ O—P ₂ O ₅ —SiO ₂ composition system, the glass melt of the raw material exhibits high viscosity, so that the foaming is poor and the temperature is 1,500 ° C.
However, there is a drawback that it is necessary to take a melting time of 2 hours or more.

Further, instead of producing a porous glass having a high silicic acid glass skeleton by the production method as described above, a titanic acid gel or a porous glass having a titanic acid produced from a metal alkoxide in the glass skeleton. However, it has drawbacks such that it takes a long time to vitrify and it is difficult to control the size of the pores of the porous glass.

The present inventor has conducted various studies and experiments on various drawbacks of the conventional porous glass and the method for producing the same as described above, and as a result, has been produced using the phase separation of the conventional oxide glass. Porous glass of silicic acid, or titanic acid gel, or significantly different from the porous glass having a glass skeleton of titanic acid produced from metal alkoxide, titanic acid and silicic acid as a glass skeleton, for example, with titanic acid We have found a titanic acid porous glass in which the glass composition ratio of silicic acid is 0.8 to 1.7 (Japanese Patent Application Nos. 58-251847 and 59-59).
92985).

Such a titanic acid porous glass has high heat resistance and chemical durability as compared with conventional porous glass, and T
Since it has an i-OH group, it has the advantage of high chemical reactivity.

The present inventor has conducted further research and experiments on a method for producing a titanic acid porous glass having the above-described various characteristics, and as a result, found that the same titanic acid porous glass has TiO ₂ —SiO _2.
5- Al ₂ O ₃ -P ₂ O ₅ -CaO composition system or Ti
_{O 2 -SiO 2 -Al 2 O 3} -P 2 O 5 -CaO (Mg
_{O) - (X 2 O)} - (YmOn) composition system (where _X 2 O
It has been found that can be produced extremely efficiently from an alkali metal oxide and YmOn is a metal element oxide. Further, as shown in the above both composition systems, by having phosphoric acid (P ₂ O ₅ ) in the titanic acid porous glass composition system, the moldability is good, and crystallization during molding is difficult to occur and stable. It has been found that it is possible to produce a titanic acid porous glass having excellent properties and constant quality.

The titanic acid porous glass produced in this manner carries a TiO ₂ crystalline phase formed during the phase separation and heat treatment steps, and is therefore referred to as “titanic acid porous glass ceramics” in the present invention. Praised. The present invention has been made based on such novel findings.

Accordingly, a main object of the present invention is to provide a titanic acid porous glass ceramic having a glass skeleton made of titanic acid and silicic acid, which have good heat resistance, chemical durability (alkali resistance) and chemical reactivity in terms of energy saving. It is to provide a method capable of manufacturing.

An object of the present invention is to provide a method for producing a titanic acid porous glass ceramics of uniform quality in a short time.

Another object of the present invention is that the melting operation is easy, crystallization hardly occurs during the quenching operation, the stability is good, and the number of cracks in the acid elution treatment stage is extremely small, that is, the titanate porous glass having good moldability. It is to provide a method for manufacturing a ceramic.

Means for Solving the Problems The above objects are achieved by the method according to the present invention. In summary, according to the present invention, a raw material consisting of a titanium oxide source, a silicic acid anhydride source, an aluminum oxide source, a phosphoric acid (P ₂ O ₅ ) source and a calcium oxide source is prepared, heated and melted, and then rapidly cooled to vitrify. _{TiO 2 -SiO 2 -Al 2 O 3} -P 2 O 5
-CaO composition system multi-component oxide glass 700 ℃ ~ 10
After reheating at a temperature of 00 ° C for a certain period of time to form a phase-separated crystallized glass, the phase-separated crystallized glass is immersed in a solution of an acid to dissolve and remove soluble components. This is a method for producing a titanic acid porous glass ceramics in which a glass skeleton supporting a crystal phase of TiO ₂ as a component remains.

Further, the present invention is mainly composed of a titanium oxide source, a silicic acid anhydride source, an aluminum oxide source, a phosphoric acid (P ₂ O ₅ ) source and a calcium oxide source, and a magnesium oxide source, an alkali metal oxide source and a metal element oxidation source. A raw material containing at least one of the material sources as a subcomponent is prepared, heated and melted, and then rapidly cooled to vitrify TiO ₂ —SiO ₂ —Al ₂ O ₃ —P.
_{2 O 5 -CaO- (MgO) -} (X 2 O) - (YmO
n) composition system (where X represents an alkali metal, Y represents a metal element other than the previous metal element, and m represents a metal element Y).
Represents the number of atoms of n, and n represents the number of oxygen atoms satisfying the oxidation number of m. ) Multi-component oxide glass of 700 ℃ ~
After reheating at a temperature of 1000 ° C. for a certain period of time to form a phase-separated crystallized glass in an opal or devitrified state, the phase-separated crystallized glass is immersed in an acid solution to elute and remove the acid-soluble component. , With titanic acid and silicic acid as the main components, T
Provided is a method for producing a titanic acid porous glass ceramics in which a glass skeleton supporting a crystal phase of iO ₂ remains.

The method for producing a titanic acid porous glass ceramics according to the present invention is schematically shown in FIG.

First, raw materials, that is, a titanium oxide source, a silicic acid anhydride source, an aluminum oxide source, a phosphoric acid (P ₂ O ₅ ) source, and a calcium oxide source are mixed in predetermined amounts. As the titanium oxide source, titanium oxide, hydroxide, alkoxide, carbonate,
Nitrate or the like is used. As the silicic acid anhydride source, silica sol, fumed silica, silica gel, silicon alkoxide, silicic acid anhydride, silicic acid alkali metal salt, feldspar, volcanic ash shirasu and the like are used. As the aluminum oxide source, aluminum alkoxide, pseudoboehmite,
Alumina, gibbsite, sodium aluminate, aluminophosphate, etc. are used. As a phosphoric acid source, a calcium salt of phosphoric acid such as calcium monohydrogen phosphate,
Magnesium salt, aluminum salt, alkali metal salt and the like are used. As the calcium oxide source, calcium carbonate, calcium salt of phosphoric acid or the like is used.

Further, in the method of the present invention, when a magnesium oxide source, an alkali metal oxide source and a metal element oxide source are used, oxides of those metals, alkoxides, carbonates, nitrates, carboxylates, etc. Phosphates, aluminates, silicates, etc. are used. Here, the alkali metal refers to lithium, sodium, potassium and the like, and the metal element refers to the metal as described above, that is, titanium, aluminum, calcium, magnesium, other metals excluding the alkali metal, for example. , I in the periodic table
B, IIB, IIIB, IVB, VB, VIB, VIIB, IIA,
Examples include metals such as IIIA, IVA, VA, iron group, and platinum group. Particularly preferred are copper, silver, gold, zinc, cadmium, yttrium, germanium, tin, lead, zirconium, bismuth, vanadium, niobium, tantalum, chromium, molybdenum, tungsten, manganese, technitium, rhenium, iron, cobalt, nickel. , Ruthenium, rhodium, palladium, iridium, platinum, lanthanides, actinides, and the like.

The compounded ingredients are then melted. Melting is generally 1
It is carried out at a temperature of 400 ° C to 1500 ° C for 10 minutes to 60 minutes. Next, this melt is put into water or cooled using various devices for rapid cooling to obtain a transparent raw material glass.

In order to obtain the porous glass ceramics of the present invention, it has been found that there is a suitable region in the composition of the above raw material glass. According to a preferred embodiment of the present invention, the composition of the raw oxide glass is such that titanium oxide is 7.5 to 40 mol%, silicic acid anhydride is 10 to 40 mol%, and aluminum oxide is 7.5 to 20 mol%. Phosphoric acid (P ₂ O ₅ )
Is 1 to 10 mole percent, calcium oxide is up to 40 mole percent, more preferably 20 to 30 mole percent titanium oxide and 2 silicic anhydride.
5 to 35 mole percent, aluminum oxide 10 to 1
5 mole percent, 1 to 5 mole percent phosphoric acid _(P 2 _{O 5),} calcium oxide is one such that 25 to 35 mole percent. When a subcomponent is present, a suitable composition range is 7.5 to 40 mol% titanium oxide, 10 to 40 mol% silicic acid anhydride, and 7.5 to 20 mol% aluminum oxide.
Phosphoric acid (P ₂ O ₅ ) is 1 to 10 mol%, calcium oxide is up to 40 mol%, magnesium oxide is 1 to 40 mol%, and alkali metal oxides are 0 to 0 mol%.
7.5 mol%, such that the content of the metal element oxide is 0 to 5 mol% or less, more preferably 20 to 30 mol% of titanium oxide and 25 of silicic anhydride.
~ 35 mole percent, aluminum oxide 10-15
Mole percent, phosphoric acid (P ₂ O ₅ ) 2 to 5 mole percent, calcium oxide 25 to 35 mole percent,
The content of magnesium oxide is 1.0 to 2.5 mol% and the content of the metal element oxide is 2 mol% or less.

This raw oxide glass is then subjected to a phase separation heat treatment. This is the raw material oxide glass 700 ℃ ~ 1000 ℃
Heating for 0.5 to 100 hours, whereby the transparent glass is changed to opal-like glass or devitrified glass to form a phase-separated crystallized glass.

Depending on the composition, partial phase crystallization may occur during the rapid cooling operation in the previous stage.

By dipping this phase-separated crystallized glass in a solution of an acid at 60 to 100 ° C. for 0.5 to 48 hours, the acid-soluble component (A
(I ₂ O ₃ , P ₂ O ₅ , CaO, MgO, X ₂ O) is partially or entirely eluted. The elution of the acid-soluble component changes depending on the type and concentration of the acid used, temperature, time and the like. Examples of the acid used include hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid and the like.

In the present invention, the acid elution treatment described above does not elute the metal element oxide mainly composed of heavy metals, and the metal element oxide is supported in the titanic acid porous glass skeleton. As described above, the ability to support the metal element oxide on the porous carrier means that the internal energy state of the porous glass ceramics can be controlled, and when used for the use as a catalyst or other functional ceramics. It becomes important.

By the acid elution treatment as described above, acid-insoluble TiO ₂
And a glass skeleton of SiO ₂ remains, and a porous glass ceramic supporting a crystal phase of TiO ₂ is manufactured.

The porous glass ceramics produced by the method of the present invention has a high specific surface area of 30 to 500 m ² / g and an average pore diameter of 1
It has a pore volume of 0 to 200Å and a pore volume of 0.1 to 0.6 ml / g, and can be used as an adsorbent, a catalyst, a catalyst carrier, a gas sensor, an ultrafiltration material, an immobilized oxygen carrier and the like.

According to the method of the present invention, the viscosity of the glass melt is low, so that the defoaming is good, and at a temperature of 1400 to 1500 ° C, 10 to 10
A uniform glass can be obtained by melting for 60 minutes. or,
As can be seen from FIG. 2, Tg point (723 ° C.) and T
It has a long time between the point c1 (crystallization temperature 847 ° C.), crystallization hardly occurs at the time of molding, and is excellent in stability and moldability.
As described above, according to the present invention, it is possible to stably manufacture the inorganic porous material titanic acid porous glass ceramics in an energy-saving and stable manner as compared with the conventional porous glass.

Preferred Embodiments of the Invention Next, the method for producing the titanic acid porous glass ceramics according to the present invention will be described in more detail.

Experimental Example 1 Titanium dioxide (TiO ₂ ), silicic acid anhydride (SiO ₂ ), aluminum oxide (Al ₂ O ₃ ), calcium hydrogen phosphate (C
It is prepared by using a reagent such as aHPO ₄ ), calcium carbonate (CaCO ₃ ), magnesium oxide (MgO) as a raw material.
After mixing the raw material bag with a ball mill or the like, 1400
C. to 1500.degree. C. in an electric furnace for 10 minutes to 60 minutes to melt and melt, and then put into water or cooled using various devices for rapid cooling to obtain a transparent raw material glass. The raw material glass composition at this time is shown in Table 1.

FIG. 2 shows the result of DTA analysis (thermal analysis) of the raw glass shown in Table 1 which was vitrified by the above method.
The measurement was performed using a DTA analyzer manufactured by Rigaku Denki Co., Ltd., and about 70 mg of a finely ground material glass sample was measured at a temperature rising rate of 10 ° C./min. TiO ₂ -SiO ₂ -Al ₂ O
_{3 -P 2 O 5 -CaO (-MgO} ) multicomponent oxide glass having the composition system has a marked exothermic peak between the 700 ° C. C. to 1100 ° C. As shown in DTA curve of FIG. 2.

Crystallization of TiO ₂ crystals (anatase, rutile) CaAl ₂ SiO is involved in this exothermic reaction. The low temperature side peak is TiO ₂ crystallization and the high temperature side peak is CaAl ₂ S.
The crystallization of iO 2 is involved. The endothermic start point indicated by TG in FIG. 2 is Tg (glass transition temperature), and in the phase-separating glass, the phase separation of the glass is induced by heat treatment at a temperature of Tg or higher.

Therefore, in the composition system of the present invention, the Tg value is somewhat changed depending on the glass composition, but the heat treatment is performed at a temperature of about 700 ° C. or higher.

In the raw glass having the composition of the present invention, as shown in FIG. 2, the temperature immediately above the glass transition point (800 to 110) was used.
An exothermic peak due to an exothermic reaction of crystallization is observed at 0 ° C. Therefore, when heat treatment is performed at a temperature between 700 ° C. and 1100 ° C., crystallization occurs at the same time as phase separation, and the phase-change crystallized glass is formed. It should be noted that the temperature is lower than the crystallization exothermic peak (Tg
Even when the heat treatment is performed at (between 1 and 2), the crystallization activation energy is reached when the material is heated for a long time, crystallization gradually occurs, and a phase-separated crystallized glass is obtained.

The upper limit of the phase separation heat treatment temperature is a temperature at which crystallization of CaAl ₂ SiO occurs. With the formation of this crystal, TiO ₂ —S
SiO ₂ forming the porous skeleton of iO ₂ is reduced. The temperature varies depending on the composition, but is in the range of 900 ° C to 1100 ° C.

In addition, in the DTA curve shown in FIG.
Some endothermic peaks near 350 ° C. are endothermic peaks due to melting of the above-mentioned produced crystals. From these results, in the composition system according to the present invention, the melting operation of the raw material is 138
It can be understood that it is necessary to carry out at a temperature of 0 ° C. or higher.

Therefore, in the composition system according to the present invention, the raw material bag is melted at a temperature of 1380 ° C. or higher to be vitrified, and then 70
It is necessary to perform the phase separation heat treatment at a temperature between 0 ° C and 1000 ° C.

The raw material glass thus obtained by the above method is 70
At a temperature between 0 ° C and 1000 ° C for a certain period of time, that is, 0.5
When heated for 10 hours, it changes from transparent glass to opal glass or devitrified glass and a phase-separated crystallized glass can be obtained. Depending on the composition, phase separation crystallization may occur during the rapid cooling operation. (In the case of Experimental Example 8 shown in Table 5) This phase-separated crystallized glass was immersed in an acid at 60 to 100 ° C., in this experimental example, a hydrochloric acid, nitric acid, sulfuric acid, or phosphoric acid solution having a concentration of 0.1N to 10.0N. When it is immersed for 0.5 to 48 hours, the acid-soluble components are removed, the glass skeleton of TiO ₂ and SiO ₂ insoluble in acid remains, and a porous glass ceramic carrying a crystal phase of TiO ₂ is produced.

The composition of the titanic acid porous glass ceramics produced in this way is shown in Table 1.

From the results shown in Table 1, Al other than TiO ₂ and SiO _{2 was obtained} by acid elution treatment of the phase-separated crystallized glass after the phase-separation heat treatment.
₂ O ₂ -P ₂ O ₅ most of the components of -CaO-MgO is found to be eluted and removed.

Through the present invention, the composition analysis of the raw material glass and the titanic acid porous glass ceramics was carried out by the following methods by wet chemical analysis.

That is, SiO ₂ is a gravimetric method, TiO ₂ , Al ₂ O ₃ ,
CaO, MgO, and metal element oxides were quantified by atomic absorption spectrometry after dissolving in hydrofluoric acid sulfuric acid, and P ₂ O ₅ by absorptiometry.

FIG. 3 and FIG. 4 show the difference in the crystal phase generated by the phase-separation heat treatment performed on the raw glass formed into a plate shape. A is a TiO ₂ crystal anatase in FIG, R represents shows the X-ray diffraction peak of the crystal rutile TiO _2, respectively. It can be seen from FIG. 3 that when the temperature of the phase-separation heat treatment is increased, the crystal phase changes from the difficulty of anatase to the rutile type. Also, from FIG. 4, low temperature (780
(° C), it is observed that the anatase type changes to the rutile type as the heat treatment time increases. Incidentally, 78
0 ° C. is the temperature before the crystallization exothermic peak of the DTA curve in FIG. 2, and 880 ° C. is the temperature after the exothermic peak.

The crystalline phase generated by these phase-separation heat treatments is supported in the porous glass ceramics after the acid elution treatment, so that by controlling the phase-separation heat treatment conditions, a titanate porous glass ceramics in which the generated crystals are controlled is produced. You know you will get.

5 and 6 show the specific surface area of the titanic acid porous glass ceramics when the phase-separation heat treatment conditions (temperature and time) were changed when the titanic acid porous glass ceramics were produced using the raw material compositions shown in Table 1. Shows the change of. The surface area was measured by a BET method (a nitrogen gas adsorption method) for a sample degassed at 200 ° C. according to the present invention.

As can be seen from FIGS. 5 and 6, the specific surface area decreases as the heat treatment temperature increases and the heat treatment time increases.

FIG. 7 shows the pore size distribution of the porous glass ceramics produced by subjecting the raw material glass of Experimental Example 1 to phase heat treatment at 760 ° C. for 12 hours. By the above-mentioned phase separation heat treatment time, a porous glass ceramic having a specific surface area of 172 m ² / g, an average pore radius of 57 Å and a pore volume of 0.49 ml / g was produced. These measurements were performed on a sample degassed at 200 ° C. using a soap mat manufactured by Carlo Carlo Eld Co., Ltd. In the present invention, the pore distribution was measured under the same conditions using the above-mentioned device.

Experimental Examples 2, 3 and 4 Experimental Examples 2, 3 and 4 are TiO ₂ —SiO ₂ —A shown in Table 2.
In _{l 2 O 3 -P 2 O 5} -CaO5 components in the raw material composition system similar to Experimental Example 1 of the method is the experimental example of producing a porous glass ceramic try at minute heat treatment conditions and shown in Table 15 . The raw material composition, the raw material glass composition, and the composition of the produced porous glass ceramics of each experimental example are shown in Tables 2 to 4. The chemical analysis of each component was performed in the same manner as in Experimental Example 1.

FIG. 8 shows D of the raw material glass of Experimental Examples 2 to 4 in Table 3, Experimental Example 6 in Table 5 and Experimental Example (Comparative Experimental Example) 16 shown in Table 9.
The results of TA analysis are shown together. As shown in the DTA analysis of FIG. 2, in the raw material glass having the composition capable of producing the porous glass ceramics, the temperature is between 700 ° C. and 800 ° C. and between 950 ° C. and 1100 ° C.
It has a significant exothermic peak between ° C. Figure 8 shows TiO
It is shown that the exothermic peak between 700 ° C. and 800 ° C. becomes gradually smaller as the content of ₂ decreases.

FIG. 9 shows the composition of Experimental Examples 2, 3, and 4 shown in Table 2,
The pore distribution of the porous glass ceramics produced under the phase separation heat treatment conditions shown in Table 15 and the porous glass ceramics produced under the phase separation heat treatment conditions also shown in Table 15 from the compositions of Experimental Examples 11 and 12 shown in Table 6 are shown. It is shown collectively.

As can be seen from the results of Experimental Examples 2, 3, and 4, it is confirmed that the pore volume decreases as the TiO ₂ content decreases. The measurement results of those pore volumes are shown in Table 15.

When the results shown in FIGS. 8 and 9 are compared with the composition of the porous glass ceramics shown in Table 4, the TiO ₂ content decreases and the exothermic peak on the low temperature side (700 to 800 ° C.) of DTA is found. As it becomes smaller, remaining Al ₂ O ₃ −
It can be seen that the amount of P ₂ O ₅ —CaO component increases and the pore volume decreases.

From the above results, as TiO ₂ decreases, TiO ₂ and S
_Al 2 _O 3 _-P 2 _{O 5} to form a porous skeleton of iO ₂ -
It is considered that the phase separation (phase separation) of the CaO acid-soluble component phase caused by the phase-separation overheat treatment becomes insufficient, and the portion that is not dissolved even by the acid treatment increases.
Therefore, it can be understood that a porous body cannot be produced from a composition having a TiO ₂ content of 5 mol% or less as shown in Experimental Example (Comparative Experimental Example) 16 in Table 9. On the other hand, the TiO ₂ content as shown in Experimental Example (Comparative Experimental Example) 17 in Table 9 was 4
When the composition is 0 mol% or more, crystal precipitation occurs during the quenching operation of the glass melt, and it becomes difficult to produce a uniform raw material glass. When the composition of TiO ₂ is close to 40 mol%, vitrification is possible by using an apparatus for ultra-quenching such as twin rolls.

FIG. 10 shows Al ₂ O ₃ -P ₂ O ₅ -CaO-MgO which is soluble in acid with respect to the components forming the porous skeleton of TiO ₂ and SiO ₂ for the experimental compositional examples carried out in the present invention.
The component phase is regarded as a group of components soluble in acid, and TiO ₂ and Si
Fig. 3 is a diagram showing a composition region in which a porous glass ceramics can be produced by drawing a diagram of three components of O ₂ and an acid-soluble phase. Numerical values are shown in mol%, and the O mark indicates a composition side where production was possible, and the X mark indicates a composition experiment example (comparative experiment example) where production was impossible.

From FIG. 10, the composition region in which the titanic acid porous glass ceramics can be manufactured is 7.5 to 40 mol% of TiO _{2 and} 10 to 45 mol% of SiO ₂ Al ₂ O ₃
-P ₂ O ₅ -CaO-MgO phase can be seen that in the range of 40 to 55 mole percent.

Experimental Examples 5 to 10 By setting the contents of TiO ₂ and SiO ₂ in the substantially central portion of the region where the titanic acid porous glass ceramics of FIG. 10 can be manufactured, Al ₂ O ₃ -P ₂ O soluble in acid is set. ₅ and Ca
The raw material compositions of the glass produced by changing the respective contents of the alkaline earth metal oxides of O and MgO are the compositions of Experimental Examples 5 to 10 shown in Table 5. The raw material of P ₂ O ₅ is C
aHPO ₄ 2H ₂ O (calcium hydrogen phosphate) is used, and is shown as the number of moles of P ₂ O ₅ by conversion, and CaH
Calcium from PO ₄ 2H ₂ O is added to the mole percent of CaO. Throughout the present invention, the raw material composition is expressed in the same manner by calculating the mole percentages of P ₂ O ₅ and CaO.

Porous glass ceramics having the same specific surface area and pore volume shown in Table 15 were produced from the compositions of Experimental Examples 5 to 10 under the phase separation heat treatment conditions shown in Table 15.

_{3 of} these Al ₂ O ₃ , P ₂ O ₅ , and CaO + MgO
FIG. 11 is a phase diagram of the composition showing a region where the porous glass ceramics can be manufactured. O is a compositional experimental example in which manufacture is possible, and X is a compositional experimental example (experimental example (comparative experiment example) in Table 9) 14, 15 and 18 in which manufacture is impossible. Numerical values are shown as molar percentages of the three compositions, and the molar numbers of TiO ₂ and SiO ₂ are excluded.

From the results shown in FIG. 11, the composition regions in which the titanic acid porous glass ceramics can be manufactured are Al ₂ O ₃ and P ₂ O.
₅ , the composition of CaO + MgO in terms of mole percent of each other is 15 to 40 mole percent of Al ₂ O ₃ , P ₂ O ₅
1.0 to 25 mol%, CaO + MgO is 65
It can be seen that it is ˜85 mole percent. In addition, about 50 mol% of TiO ₂ and S are added.
Considering the number of moles of iO ₂ , it can be seen that the amount added to the raw material composition is about half of the above-mentioned mole percentage of Al ₂ O ₃ , P ₂ O ₅ , and CaO + MgO 3 components.
Therefore, Al ₂ O ₃ , P ₂ O ₅ , CaO + MgO that can be added to the raw material composition to produce porous glass ceramics.
It is understood that the molar percentage region of Al ₂ O ₃ is in the range of 7.5 to 20 mol%, P ₂ O ₅ is in the range of 0.5 to 10.0 mol%, and CaO + MgO is in the range of 20 to 40 mol%. It

Experimental Examples 11 and 12 For a porous glass having MgO in the raw material composition and manufactured by the same method as in Experimental Example 1 and under the heat treatment conditions shown in Table 15, the raw material composition, the raw material glass composition, and the manufactured The composition of the porous glass is shown in Tables 6-8. The pore distribution of the produced porous glass ceramics is shown in FIG. The pore distribution of the porous glass ceramics from Experimental Example 12 in FIG. 9 has a peak near a pore radius of 100 angstroms, and this pore radius generally shows a large value as the phase separation temperature increases. That SiO
_In Experimental Example 12 known in the _2- B ₂ O ₃ —Na ₂ O composition system, the phase-separation heat treatment was performed at 880 ° C., and the phase-separation heat treatment was performed from the experimental example 11 at 800 ° C. and the experimental example 2 at 850 ° C. It is understood that the pore radius is increased due to the high value. On the other hand, when the compositions of the porous glass ceramics manufactured in Experimental Example 11 and the porous glass ceramics manufactured in Experimental Example 12 are compared, Al ₂ O ₃ is contained in the composition of Experimental Example 12 having a high TiO ₂ content. It can be seen that the content is high.

Therefore, TiO ₂ --S from the composition region having a high TiO ₂ content is obtained.
It is considered that the porous glass ceramics containing iO ₂ —Al ₂ O ₃ as a main component is manufactured.

The addition of an appropriate amount of MgO has the effect of significantly reducing the cracking of the molten glass during cooling, and is particularly effective when shaping sheet glass.

Experimental Examples (Comparative Experimental Examples) 13 to 19 In Experimental Examples 13 to 18, the glass subjected to the phase-separated heat treatment does not dissolve in acid (Experimental Examples 13, 16, 19-1), and the phase-separated heat-treated glass dissolves in the acid. For example, due to the fact that impurities are left at the bottom of the molten crucible (Experimental Examples 19) (Experimental Examples 14 and 15), crystallization has already occurred and devitrification occurs in the process of quenching vitrification (Experimental Examples 17 and 18). This is a comparative experiment example in which a porous glass ceramic could not be manufactured. These comparative composition experimental examples are shown by X in FIGS. 10 and 11.

Experimental Examples 20 to 23 It was shown in Experimental Examples 11 and 12 that the titanic acid porous glass ceramics can be produced from the composition to which MgO was added, but even from the composition in which CaO is partially or entirely replaced with MgO, The porous glass ceramics could be manufactured by the process shown in FIG. Experimental Examples 20 to 23 are Ca
It is an experimental example of a raw material composition in which a part or all of O is replaced with MgO. From each composition shown in Experimental Examples 20 to 23, Table 15
Under the heat treatment conditions shown in Table 1, a porous glass ceramic having the same specific surface area and pore volume as shown in Table 15 can be manufactured.

Experimental Examples 24 to 27 In addition to the composition in which CaO is replaced by MgO, a composition in which a part of CaO is replaced by an alkali metal oxide of Na ₂ O or Li ₂ O, and a part of P ₂ O ₅ is B ₂ O. _The titanic acid porous glass ceramics can be manufactured by the process shown in FIG. 1 from the glass having the composition replaced by ₃ . Experimental Examples 24 and 2
5 is a composition in which a part of CaO is replaced with Na ₂ O, Experimental example 26 is a composition in which Li ₂ O is replaced, Experimental example 27 is P ₂ O
It is a composition in which a part of ₅ is replaced with B ₂ O ₃ . Porous glass ceramics having specific surface areas and pore radii as shown in Table 15 were produced from the raw material compositions of these experimental examples under the phase separation heat treatment conditions shown in Table 15. In addition, Na
_In the raw material composition of Experimental Example (Comparative Experimental Example) 39 shown in Table 14 in which ₂ O was used at 10 mol%, insoluble matter remained in the molten crucible, and it was impossible to produce the porous glass ceramics.

Experimental Examples 28 to 36 One of the characteristics of the present invention is that the composition of the raw material is, for example, Ni ₂ O ₃ ,
ZrO ₂ , GeO _{2 and} other metal element oxides are added,
This means that such a metal element oxide can be supported on the glass skeleton. In general multi-porous glass produced from oxide-based glass, most of the metal element oxide mixed in the raw material is eluted and removed by acid treatment,
Although only traces remain in the porous gas, in the present invention, the metal element oxide added to the raw material composition is not removed by the acid elution treatment and is supported in the titanate porous glass skeleton.

Experimental Examples 28 to 36 are experimental examples in which various metal element oxides were added to the raw material composition to produce metal element oxide-supported porous titanic acid glass ceramics. The added metal element oxides and glass raw material compositions are shown in Table 12, and the compositions of the metal element oxidation-supported titanic acid porous glass ceramics produced from those raw material glass in the same process as the process of FIG. Are shown in Table 13. Table 15 shows the phase separation heat treatment temperature, the specific surface area, and the pore volume of these porous glass ceramics.

As shown in Table 12, the metallic element oxide-supporting titanic acid porous glass ceramics can be produced by using the additional metallic element oxides alone or in combination of two or more elements.

These added metal element oxides give a unique color to the manufactured titanic acid porous glass ceramics,
It has a function of suppressing crystallization when the glass melt is rapidly cooled to vitrify and reducing cracks during acid elution treatment.

The fact that the metal oxide can be supported on the porous carrier in this way means that the internal energy state of the porous glass ceramics can be controlled, and when used for the use as a catalyst or its various functional ceramics. This is an important feature.

Experimental Examples 37 to 40 The range of the addition amount of the metal oxide or the alkali metal oxide that can be added when producing the titanic acid porous glass ceramics varies depending on the element, and is 10 mol% or less in the alkali metal oxide, while For metal oxides, the amount of ZrO ₂ that can be added in a relatively large amount is 5.0 mol% or less, and for noble metal element oxides, it is 1.0 mol% or less, so there is a difference in the amount that can be added depending on the element. I understand.

Experimental examples (comparative experimental examples) 37 to 40 shown in Table 14 are crystallized in a glass melt when an attempt is made to produce a raw material glass by adding a metal element oxide and an alkali metal oxide,
This is a comparative experimental example in which a uniform molten glass could not be produced due to the formation of a precipitate due to insolubility. Ni ₂ O ₃ 5 mol% (Experimental Example 37) ZrO ₂ 7.5 mol% (Experimental Example 38), RuO ₂ 1.5 mol% (Experimental Example 39), Na ₂ O 10.0 mol% With the addition amount of (Experimental Example 40), a devitrification portion that precipitates in the glass melt was generated, and a uniform raw material glass could not be obtained.

Table 15 shows the specific surface area and pore volume of the titanic acid porous glass ceramics produced from the raw material glass having the composition of the experimental example carried out in the present invention by the heat treatment conditions shown in the table by the process shown in FIG. is there. The surface area is measured by a titanium gas adsorption method (BET method) for a sample degassed at 200 ° C. as described above, and the pore volume is a value measured by a soap mat manufactured by Carlo Carlo Erba Co. of Italy.

EFFECTS OF THE INVENTION AND INDUSTRIAL APPLICABILITY According to the present invention, a titanic acid porous glass ceramic having a glass skeleton made of titanic acid and silicic acid having good durability, chemical durability (alkali resistance) and chemical reactivity is provided. Furthermore, according to the present invention, a high-quality titanium that is easy to melt and does not generate crystals in the quenching vitrification step, has few cracks in the stage of acid elution treatment, and has excellent formability and stability. An acid porous glass can be provided.

The titanic acid porous glass according to the present invention has the above-mentioned characteristics and is suitably used as an adsorbent, a catalyst, a catalyst carrier, a gas sensor, an ultrafilter, a reaction separation membrane, an immobilized oxygen carrier, and the like. obtain.

[Brief description of drawings]

FIG. 1 is a block diagram showing a manufacturing process of a titanic acid porous glass ceramics. FIG. 2 is a DTA curve between 600 ° C. and 1400 ° C. measured for the raw material glass powder of Experimental Example 1 at a temperature rising rate of 10 ° C./min, and particularly Tg value (723 ° C.) and Tc1 value (crystallization temperature). 847 ° C.) is increasing. FIG. 3 shows X-ray diffraction patterns when the raw material glass plate of Experimental Example 1 was subjected to the phase-separation heat treatment at various temperatures while keeping the heating time constant. The symbol A in the figure is crystalline anatase of TiO ₂ , R
Is also a diffraction peak of crystalline rutile of TiO ₂ . FIG. 4 shows the raw glass plate of Experimental Example 1 at 780 ° C. and 8 ° C.
The X-ray-diffraction figure at the time of heating at the heating temperature of 80 degreeC for a long time is shown. The abbreviations A and R are the same as in FIG. FIG. 5 shows that the raw material glass of Experimental Example 1 was heated at a constant heating time of 8
Changes in the surface area of the titanic acid porous glass ceramics produced by performing the phase-separation heat treatment at various temperatures as time are shown. FIG. 6 shows the raw material glass of Experimental Example 1 at 780 ° C. and 880 ° C.
The change of the surface area of the titanic acid porous glass ceramics manufactured by carrying out the phase separation heat treatment at ℃ for a long time is shown. FIG. 7 shows that the raw glass of Experimental Example 1 was used at 12 ° C. at 760 ° C.
The pore distribution of the titanic acid porous glass ceramics manufactured by the phase separation heat treatment condition of time is shown. FIG. 8 shows 500 ° C. to 12 ° C. when the raw material glass powders of Experimental Examples 2, 3, 4, 6, and 16 were measured at a temperature rising rate of 5 ° C./min.
The DTA curve between 00 ° C is shown. Tg in the figure indicates the glass transition temperature. FIG. 9 shows the pore distribution of the titanic acid porous glass ceramics produced from the raw material glasses of Experimental Examples 2, 3, 4, 11 and 12 under the phase splitting heat treatment conditions shown in Table 15. FIG. 10 shows Ti for the glass composition carried out in the present invention.
It is shown as a three-composition phase diagram of an O ₂ —SiO ₂ -acid-soluble phase, and shows a region where the titanic acid porous glass ceramics can be manufactured. Numbers indicate mole percentages. FIG. 11 shows that Al ₂ O ₃ , P ₂ O ₅ , and CaO-Mg which are acid-soluble components in the glass composition of the present invention.
O (alkali oxides) is represented by a three-composition phase diagram,
The area | region where a titanic acid porous glass ceramics can be manufactured is shown. The values are given as mole percent of the three compositions,
The amount added to the actual raw material composition is about half.

Claims (4)

[Claims] 1. A TiO that is prepared by mixing raw materials containing titanium oxide, silicic acid anhydride, aluminum oxide, phosphoric acid (P ₂ O ₅ ) and calcium oxide, heating and melting, and then rapidly cooling to vitrify.
_After reheating the multi-component oxide glass of the 2-SiO ₂ -Al ₂ O ₃ -P ₂ O ₅ -CaO composition system at a temperature of 700 ° C. to 1000 ° C. for a certain time to form a phase-separated crystallized glass, By immersing phase-phase crystallized glass in an acid solution to elute and remove soluble components, Ti
A method for producing a titanic acid porous glass ceramics in which a glass skeleton supporting an O ₂ crystal phase remains. 2. The composition of the multi-component oxide glass comprises 7.5 to 40 mol% of titanium oxide and 10 to 10 of silicic acid anhydride.
45 mole percent, aluminum oxide 7.5-20
Mole percent, 1 to 10 mole percent phosphoric acid _(P 2 _{O 5)} The method of claim 1 wherein the range of the is claimed up to 40 mole percent calcium oxide. 3. Titanium oxide, silicic acid anhydride, aluminum oxide, phosphoric acid (P ₂ O ₅ ) and calcium oxide as main components, and at least one of magnesium oxide, alkali metal oxides and metal element oxides. TiO that was prepared by mixing the raw materials contained as subcomponents, heating and melting, and then rapidly cooling to vitrification
_{2 -SiO 2 -Al 2 O 3 -P} 2 O 5 -CaO- (Mg
_{O) - (X 2 O)} - (YmOn) composition (X represents an alkali metal, Y represents a metal element other than the metal element, m represents the atomic number of the metal elements Y, n is the number of atoms m (Representing the number of oxygen atoms satisfying the oxidation number of 1.) is reheated at a temperature of 700 ° C. to 1000 ° C. for a certain period of time to obtain an opalized or devitrified split-phase crystallized glass, By dipping this phase-separated crystallized glass in an acid solution to elute and remove the acid-soluble component, the titanic acid porosity containing titanic acid and silicic acid as the main components and the glass skeleton supporting the crystal phase of TiO ₂ remains. Of manufacturing high quality glass ceramics. 4. The composition of the multi-component oxide glass comprises 7.5 to 40 mol% of titanium oxide and 10 to 10 of silicic acid anhydride.
40 mole percent, aluminum oxide 7.5-20
Mole percent, phosphoric acid (P ₂ O ₅ ) is 1 to 10 mole percent, calcium oxide is up to 40 mole percent,
The manufacturing method according to claim 3, wherein the magnesium oxide is 0 to 40 mol%, the alkali metal oxide is 0 to 7.5 mol%, and the metal element compound is 0 to 5 mol%.