JPS6168348A - Production of porous titanic acid glass plate - Google Patents

Abstract

PURPOSE:To easily produce titled flat glass which is made of the glass skeleton consisting essentially of titanic acid and silicic acid and is stable to a heat treatment and oxidation treatment by forming specifically composed flat glass to phase-separated glass then immersing the glass into an acid soln. to elute away the soluble components. CONSTITUTION:(i) The raw materials mixed at a ratio each of (TiO2+SiO2)/(Al2 O3+B2O3+CaO+MgO)=1.2-1.4 (molar, hereafter the same), TiO2/SiO2=0.5-1, B2O3/Al2O3=1-0.6, MgO/CaO=0.21-0.06 are heated to melt and vitrify and the molten glass is molded to a plate shape. (ii) The resulted flat glass is heated to 600-900 deg.C to form the phase-separated glass and thereafter (iii) the glass is treated with the acid soln. (e.g./ an aq. soln. of about 0.5-1N hydrochloric acid) to remove the soluble components. The treated glass is dried and is tempered by a heat treatment if necessary. The porous titanic acid glass is thus obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a titanic acid-containing porous glass (herein referred to as "
It is called "Titanic acid porous crow".

), and particularly relates to a method of manufacturing a plate glass-like porous titanate glass, that is, a porous titanate glass plate.

At present, it has been processed into a plate shape and has countless pores with diameters ranging from several angstroms to several thousand angstroms, and can be widely used in catalysts, gas sensors, reaction separation membranes, adsorbents, etc. Porous glass has been proposed. Such porous glass is generally manufactured from oxide glass,
Those manufactured from the SiO2-Bz 03-N az O composition system, SiO2-Bz 03-N az O-
Products manufactured from the Alz 03-CaO-MgO composition system have already been reported and put into practical use. All of these porous glasses are highly silicic and are used for producing high silicate glasses such as Vycor glass. S like this
i 02-BZ 03-N az O composition system and S
i Oz -BZ 03 -N
az O-A IZ 03 -CaO-
Porous glass manufactured from the MgO composition system has a feature that can be controlled by adjusting the heat treatment conditions during phase separation, which has large pores.

Shikashinakara, 42nd S i OZ BZ 03-N
azO composition system and S i O2-Bz 03-N a
When producing porous glass from the z O-A I Z O3-Ca O-M g O composition system, the raw glass melt exhibits high viscosity, so bubbles νJ, jL-, ・I think 1
．． There was a drawback that it was necessary to take a melting time of 7 hours or more at 500°C.

Also, instead of producing porous glass having a highly silicic acid glass skeleton using the above production method, titanate gel,
Porous glasses with titanic acid produced from metal alkoxides in the glass skeleton have been reported, but vitrification takes a long time and it is difficult to control the pore size of porous glasses. It has the following disadvantages.

The present inventor conducted various studies and experiments in order to improve the various drawbacks of the conventional porous glass and its manufacturing method as described above, and as a result, the present inventor discovered a method for manufacturing the same using phase separation of conventional oxide glass. This is significantly different from porous glasses with high silicic acid or titanate gels or porous glasses with a titanate glass skeleton made from metal alkoxides, such as titanate and silicic acid glass skeletons. We have found a titanate porous glass in which the glass composition ratio of titanic acid and silicic acid is 0.8 to 1.7.

Such titanate porous glass has greater heat resistance and chemical durability than conventional porous glass, and has T
Since it has an i-OH group, it has the advantage of high chemical reactivity.

The present inventor previously proposed a method for producing such porous glass very effectively (Japanese Patent Application No. 58-251847).

The manufacturing method according to the application is basically T i Oz −
S i Oz −A l z O3−B z O] −
A titanate porous glass was produced from a CaO-MgO(7)6 composition. However, this method has problems in that the melting operation is difficult, crystallization tends to occur during rapid vitrification, and cracks and cracks appear during the oxidation treatment stage. In other words, if such cracking and cracking occur during acid treatment, it becomes impossible to produce titanate porous glass plates that are effective as catalysts, gas sensors, reaction membranes, and adsorbents.

As a result of further research and experiments, the inventor found that cracking and separation during oxidation treatment are due to crystallization and expansion of the glass during acid treatment, etc. It has been found that cracking and separation can be solved by specifying the glass composition.

The present invention has been made based on this new knowledge.

Therefore, the present invention provides a titanate porous glass plate having a glass skeleton of titanic acid and silicic acid.
S i O2-A I203 Bz 03-Ca O
An object of the present invention is to provide a method for manufacturing from six compositions of -MgO.

The aim of the present invention is to provide a method for producing titanate porous glass plates in a short time and of uniform quality.

Another object of the present invention is to provide a method for producing a titanate porous glass plate that is easy to melt, is difficult to crystallize during rapid vitrification, and has extremely few cracks and cracks during the oxidation treatment step. be.

To summarize the invention, according to the invention titanium oxide (T
iOz), silicic anhydride (SiO2), aluminum oxide (AI2O3), boron oxide (BZ 03 ), calcium oxide (Cab), and magnesium oxide (M g
O) with the following composition expressed in mol% of oxide: (TiO2+SiOz)/(Alzo3+e
zo 3 +CaO+8g0)
1.20~1.40TiO2/5iQz
0.5-1. OB z O3/Al
z O31,0~0.6Mg0/GaOO,21~0.
Ti02-S was mixed so as to have 0ft and then vitrified.
i O2-A lz 03 -Bz 03
-CaO-MgO composition sheet glass-like multicomponent oxide glass at 600 to 900°C, preferably 700 to 850°C,
In particular, after reheating at a temperature of 750 to 800°C for a certain period of time to obtain a split phase glass in an opal state or a devitalized state, this split phase glass is immersed in an acid solution to elute and remove acid-soluble components. , a method for manufacturing a titanate porous glass plate in which a glass skeleton mainly composed of titanic acid and silicic acid remains.

In a preferred embodiment, the TiO2/SiO2 value is between 0.5 and 1. Luniturete increases in the range of O, B
The values of Z O3/A l z 03 and MgO/CaO are reduced.

Furthermore, in a preferred embodiment, a portion of 5iOz (
(about 0.5 mol%) as a metal element oxide, e.g. MoO3
, 5eO1 or N12O3, etc., whereby the metal element oxide is supported on the porous glass framework and 1
The separation can be reduced.

In a preferred embodiment of the invention, the titanium oxide is 18
．． 0 to 28.0 mol percent, silicic anhydride (*3B,
O ~ 28.0 mole percent, aluminum oxide is 10
．． 0-12.5 mole percent, boron oxide 7.5 mole percent, calcium oxide 21.0-22.5 mole percent, and magnesium oxide 4.5-1.5 mole percent.

According to the production method of the present invention, the pore size and specific surface area of the titanate porous glass plate can be controlled by adjusting the heat treatment conditions during the phase separation step during production. Since the glass melt has low viscosity, bubbles are easily removed, and a uniform glass can be obtained by melting at a temperature of 1.400°C for 30 to 60 minutes. As described above, according to the present invention, a porous titanate glass plate can be produced by punching with less energy than conventional porous glass plates.

Preferable glass raw material compositions for producing the titanate porous glass plate according to the present invention are shown in Table 1, and the glass raw material compositions when metal element oxides are added are shown in Table 2. That's right.

Table 1 Table 2 Example 1 The method for manufacturing a titanate porous glass plate according to the present invention will be explained in more detail. FIG. 1 shows the manufacturing process of a titanate porous glass plate.

Raw materials Toshite 25, OT i Oz -31, 0Si
Oz-12,5AlzO3-7,5BzO3-22,5
The raw material (4) having a composition such as CaO-1,5Mg0 (molar composition) was used, and the raw material was sufficiently mixed in a ball mill etc. in an electric furnace of 1,400'0 for 30 minutes to 60 minutes.
Melt by heating for 30 minutes, then put into water, cool rapidly, and shape (roll)
0 to obtain a transparent plate glass.Then, the plate glass is
0-900°C, preferably 700-850'0, especially 7
for a certain period of time at a temperature between 50 and 800"0, i.e. 4 to 1
When heated for 2 hours, the glass changes from transparent glass to opalescent glass or devitrified glass, yielding 1-phase glass. This layered glass is o,5N-1,0Ncn90
When immersed in an acidic acid solution for 1 to 12 hours, acid-soluble components are eluted and removed, producing a porous glass plate in which the acid-insoluble TfO (SiO2) glass skeleton remains.The porous glass is immersed in a vacuum at 110°C. 700 as needed after drying
Baking and tightening was performed at ℃.

The titanate porous glass Xa) composition (weight %) produced in this way was 37.5TiOz-46,0Si
02-14, 3A lz 03-2.17CaO.

The compositional analysis of the above raw materials and titanate porous glass is
This was done by line fluorescence analysis.

The present invention has the characteristics as explained above, and can extremely easily produce a titanate porous glass plate that can be used for adsorbents, catalytic gas sensors, reaction separation membranes, etc. and has desired characteristics. A manufacturing method is thus realized. Further, according to the present invention, it is possible to provide a high-quality titanate porous glass plate that is easy to melt, is less likely to crystallize, and has fewer cracks and cracks during the oxidation treatment.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing the manufacturing process of porous titanate glass according to the present invention. Procedural amendment (method) February 27, 1985 Mr. Manabu Shiga, Commissioner of the Patent Office! Indication of progress Patent Application No. 18971 filed in 1989 Name of the invention Relationship with the case of a person amending the manufacturing method of a porous titanate glass plate Address of the person who issued the patent Mr. 34-7 Toshimi-cho, Miyakonojo City, Miyazaki Prefecture given name
Toshinori Kokufu

Claims (1)

[Claims] 1) Contains titanium oxide, silicic anhydride, aluminum oxide, boron oxide, calcium oxide and magnesium oxide,
Also, if desired, it may contain a metal element oxide and the mol% of the oxide may be
The following composition is expressed as: (TiO_2+SiO_2)/(Al_2O_3+B_
2O_3+CaO+MgO) 1.20-1.40 TiO_2/SiO_2 0.5-1.0 B_2O_3/Al_2O_3 1.0-0.6MgO
/CaO 0.21 to 0.06, heated and melted, rapidly cooled and shaped, and then vitrified into TiO_2-SiO_2-Al.
_2O_3-B_2O_3-CaO-MgO-YmOn
(YmOn is a metal element oxide added as desired) A sheet glass-like multi-component oxide glass with a composition of 600°C to 900°C
After reheating at a temperature of °C for a certain period of time to obtain a split-phase glass in an opal state or devitrification state, the split-phase glass is immersed in an acid solution to elute and remove acid-soluble components, thereby producing titanic acid and silicic acid. A method for manufacturing a titanate porous glass plate with a glass skeleton remaining as a main component. 2) Titanium oxide is 18.0 to 28.0 mol percent,
Silicic anhydride is 38.0 to 28.0 mole percent, aluminum oxide is 10.0 to 12.5 mole percent, boron oxide is 7.5 mole percent, and calcium oxide is 2
2. The method of claim 1, wherein the magnesium oxide is 1.0 to 22.5 mole percent and the magnesium oxide is 4.5 to 1.5 mole percent. 3) Metal element oxide is MoO_3, SeO_2 or Ni
The method according to claim 2, wherein _2O_3 is added in an amount of 0.5 to 1.0 mole percent.