JP2011178603A - Glass ceramic and production method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a glass ceramic having excellent surface durability and having crystal phases of at least one kind of titanium oxide selected from the group consisting of anatase, rutile and brookite types and also of an alkali earth titanium phosphate compound, and to provide its production method, and a photocatalytic member and a hydrophilic member, containing the glass ceramic. <P>SOLUTION: The glass ceramic includes at least one selected from R<SB>0.5</SB>Ti<SB>2</SB>(PO<SB>4</SB>)<SB>3</SB>and their solid solutions and also either one or both of TiO<SB>2</SB>and its solid solutions. The decomposition activation index of methylene blue based on JIS R 1703-2:2007 is at least 3.0 nmol/L/min. (In the formula, R is at least one kind selected from Be, Mg, Ca, Sr, Ba, and Zn). The glass ceramic is produced by a method including the steps of: mixing and melting raw materials to obtain a glass melt or a glass; and crystallizing it by keeping the temperature at which a crystallization nuclei are generated and grown in the melt or the glass. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to glass ceramics, use thereof, and manufacturing methods thereof. Particularly preferably, the present invention relates to a glass ceramic containing a crystal phase exhibiting a catalytic action when irradiated with light, its use as a photocatalyst, and a production method thereof.

A photocatalyst is a material that absorbs light and enters a high energy state, and uses this energy to cause a chemical reaction with a reactant. Metal ions and metal complexes are also used as photocatalysts. In particular, inorganic compounds of semiconductors such as titanium dioxide (TiO ₂ ) are known to have high catalytic activity as photocatalysts, and are most often used. ing. Semiconductors normally do not conduct electricity, but when irradiated with light with energy higher than the band gap energy, electrons move to the conduction band, and holes that have lost electrons are generated, and these electrons and holes are strong. Has redox power. This oxidation-reduction power of photocatalysts has attracted attention as an energy-free environmental purification technology because it works by decomposing, removing, and purifying dirt, pollutants, and offensive odor components as well as using sunlight. Yes. Further, it is known that the surface of a molded body containing an inorganic titanium compound has a so-called self-cleaning action that is washed with water droplets such as rain because it exhibits hydrophilicity that allows water to easily get wet when irradiated with light.

On the other hand, an inorganic compound having photocatalytic activity such as titanium oxide (TiO ₂ ) is a very fine powder and is difficult to use as it is. In most cases, it is used in the form of a film by a method such as vacuum deposition, sputtering, or plasma.
For example, Japanese Patent Application Laid-Open No. 2008-81712 includes a high concentration inorganic titanium compound in an aqueous emulsion having a synthetic resin as a dispersed phase as a coating agent used to form an inorganic titanium compound layer on the surface of a substrate. An improved photocatalytic coating is disclosed. Japanese Unexamined Patent Publication No. 2007-230812 discloses a photocatalytic titanium oxide thin film formed by gas flow sputtering using a TiO _y target. In addition, as a technique for including an inorganic titanium compound in the substrate without taking the form of a coating or a film, for example, in JP-A-9-315837, SiO ₂ , Al ₂ O ₃ , CaO, MgO, B ₂ O ₃ , glass for photocatalysts containing a predetermined amount of each component of ZrO ₂ and TiO ₂ is disclosed.

  However, when the inorganic titanium compound is applied or coated on the surface of the substrate, the durability of the coating film or coating layer is not sufficient, and the coating film or coating layer may be peeled off from the substrate. For example, when a coating film is formed using a photocatalytic coating agent disclosed in JP-A-2008-81712, a resin or an organic binder remaining in the coating film is decomposed by ultraviolet rays or the like, or a catalyst of an inorganic titanium compound As a result of being oxidized and reduced by the action, the durability of the coating film tends to deteriorate over time. In addition, the inorganic titanium compound catalyst described above requires nano-sized fine particles in order to bring out sufficient photocatalytic activity. However, such ultra-fine particles are expensive to produce and have a problem that they tend to aggregate. .

  Moreover, since the photocatalyst member using a film forming method called a so-called dry process method disclosed in Japanese Patent Application Laid-Open No. 2007-230812 is also formed as a film, there is only a concern that the photocatalytic characteristics deteriorate due to peeling. In addition, there is a problem in that a precise atmosphere control by an expensive device is required, and the manufacturing cost becomes very high.

  In addition, in the photocatalyst glass disclosed in JP-A-9-315837, titanium oxide does not have a crystal structure and exists in the glass in an amorphous form, so that its photocatalytic properties are insufficient.

As a technique for collectively solving these problems, that is, generation of crystals having photocatalytic properties and immobilization thereof, there is a technique of depositing photocatalytic crystals such as TiO ₂ from glass. Crystallized glass in which photocatalytic crystals are dispersed in the entire glass has an advantage that the characteristics of the crystals can be used semi-permanently with almost no change over time such as cracking or peeling of the surface.

For example, JP 2008-120655 A and JP 2009-57266 A disclose TiO ₂ —Bi ₂ O ₃ —B ₂ O ₃ —Al ₂ O ₃ —RO (R: alkaline earth metal) as a photocatalytic material. Disclosed is a crystallized glass in which a titanium oxide crystal is obtained by heat-treating a system glass.

JP 2008-81712 A JP 2007-230812 A Japanese Patent Laid-Open No. 9-315837 JP 2008-120655 A JP 2009-57266 A

  The present invention has been made in view of the above circumstances, and there is no need to process a thin film or coating on the surface, and a material having photocatalytic properties as a bulk material, specifically, excellent in durability and photocatalyst. An object of the present invention is to provide a glass ceramic in which fine crystals having characteristics are present inside or on the surface of the material. Furthermore, it aims at providing the photocatalyst functional member and hydrophilic member containing the glass ceramics manufactured with the manufacturing method of the glass ceramics, and this manufacturing method.

In order to solve the above-mentioned problems, the present inventors have conducted intensive test research. As a result, there is no need to use a nano-sized raw material depending on a specific composition range and manufacturing method, and titanium oxide (TiO ₂ ) and the like The present inventors have found that glass ceramics having fine crystals of an inorganic titanium compound can be obtained and have completed the present invention. Specifically, the present invention provides the following.

(1) As a crystal phase, it has R _0.5 Ti ₂ (PO ₄ ) ₃ and at least one selected from these solid solutions, and TiO ₂ and either or both of these solid solutions, JIS R 1703-2 : Glass ceramics having a decomposition activity index of methylene blue based on 2007 of 3.0 nmol / L / min or more. (In the formula, R is at least one selected from Be, Mg, Ca, Sr, Ba, Zn)

(2) The glass ceramic according to (1), wherein the crystalline phase contains one or more TiO ₂ selected from anatase type, rutile type, and brookite type.

  (3) The glass ceramic according to any one of (1) and (2), wherein the crystal phase is contained in a volume ratio of 1.0% to 99.0% with respect to the total volume of the glass ceramic.

(4) 15 to 95% of TiO ₂ component in mol% of oxide conversion composition,
1% to 70% of SiO ₂ component, P ₂ O ₅ component, B ₂ O ₃ component, and / or GeO ₂ component,
0.1 to 50% of RO component,
(In the formula, R is at least one selected from Be, Mg, Ca, Sr, Ba, Zn)
The glass ceramic according to any one of (1) to (3).

(5) The glass ceramic according to any one of (1) to (4), which contains 0 to 50% of an Rn ₂ O component in mol% of the oxide equivalent composition. (In the formula, Rn is at least one selected from Li, K, Na, Rb, and Cs)

(6) 0-30% of _Al 2 _{O 3} component in mole percent on the oxide composition in terms of,
Ga ₂ O ₃ component 0-30%,
0-30% of In ₂ O ₃ component,
0 to 20% of ZrO ₂ component,
0 to 20% of SnO component,
Bi ₂ O ₃ component and / or TeO ₂ component 0-20%
0-30% of Nb ₂ O5 component and / or Ta ₂ O5 component,
WO ₃ component 0-30%,
0-30% of MoO component,
0-30% of Ln ₂ O ₃ component (Ln is one or more selected from Y, Ce, La, Nd, Gd, Dy, Yb),
M _x O _y component 0 to 10% (M is at least one selected from V, Cr, Mn, Fe, Co, and Ni, and x and y are each x: y = 2: (valence of M)) The smallest natural number satisfying
As ₂ O ₃ component and / or Sb ₂ O ₃ component 0-5%,
The glass ceramic according to any one of (1) to (5).

  (7) 0.01% to 10% of one or more non-metallic element components selected from F, Cl, Br, S, N, and C in an externally divided mass% with respect to the total amount of glass in the oxide-based composition The glass ceramic according to any one of (1) to (6).

  (8) One or more metal element components selected from Cu, Ag, Au, Pd, Pt, Ru, Re, and Rh, in an externally divided mass% with respect to the total glass material amount of the oxide reference composition, are 0.001 to 0.001. The glass ceramic according to any one of (1) to (7), containing 5%.

  (9) The glass ceramic according to any one of (1) to (8), wherein catalytic activity is expressed by light having a wavelength from the ultraviolet region to the visible region.

  (10) The glass ceramic according to any one of (1) to (9), wherein the contact angle between the surface irradiated with light having a wavelength from the ultraviolet region to the visible region and a water droplet is 10 ° or less.

  (11) A glass ceramic molded body comprising the glass ceramic according to any one of (1) to (10).

  (12) A photocatalyst comprising the glass ceramic molded body according to (11).

  (13) The photocatalyst according to (12), which has a granular or fiber form.

  (14) A slurry mixture containing the photocatalyst described in (13).

  (15) A photocatalytic member comprising the photocatalyst according to any one of (12) to (14).

(16) A purification device comprising the photocatalyst according to any one of (12) to (14).

(17) A filter comprising the photocatalyst according to any one of (12) and (14).

(18) A sintered body obtained by sintering pulverized glass,
A sintered body comprising the glass ceramic according to any one of (1) to (10) in the sintered body.

(19) The obtained glass body is a mol% of the oxide equivalent composition, the TiO ₂ component is 15 to 95%, the SiO ₂ component, the P ₂ O ₅ component, the B ₂ O ₃ component, and / or the GeO ₂ component. Raw material prepared so as to contain 1% to 70% and 0.1 to 50% of RO component (wherein R is one or more selected from Be, Mg, Ca, Sr, Ba, Zn) A vitrification step for producing a glass body by melting and vitrifying the composition,
Crushing step of crushing the glass body to produce a crushed glass;
A molding step of molding the crushed glass into a molded body having a desired shape;
The molded body is heated to be sintered, and at least one or both of R _0.5 Ti ₂ (PO ₄ ) ₃ and a solid solution thereof, and TiO ₂ and / or a solid solution thereof are contained in the glass. A sintering step of producing a sintered body by generating a crystalline phase including,
The sintered body according to (18), which is produced by a method comprising:

(20) The sintered body according to (19), wherein the method further includes a step of mixing ZnO crystal, WO ₃ crystal and / or TiO ₂ crystal with the crushed glass.

  (21) A glass ceramic composite comprising a base material and a glass ceramic layer provided on the base material, wherein the glass ceramic layer comprises the glass ceramic according to any one of (1) to (10) A glass-ceramic composite comprising:

  (22) Glass that produces a crystalline phase having photocatalytic activity from glass by heating and becomes the glass ceramic according to any one of (1) to (10).

  (23) The glass according to (22), which has a granular or fiber form.

  (24) A slurry mixture containing the glass according to (23).

  (25) A method for producing a glass ceramic according to any one of (1) to (10), wherein the glass ceramic is melted by holding a mixture of raw materials at a temperature of 1200 ° C. or higher, and then cooled and solidified. Production method.

  (26) A method for producing a glass ceramic according to any one of (1) to (10), wherein a melting step of mixing raw materials to obtain a melt thereof, and cooling to obtain glass by cooling the melt. A reheating step for raising the temperature of the glass to a crystallization temperature range, a crystallization step for maintaining the temperature in the crystallization temperature range to form crystals, and the temperature in the crystallization temperature range. A re-cooling step of obtaining the glass ceramic by lowering it to the outside.

  (27) The glass ceramic manufacturing method according to (26), wherein the crystallization temperature region is 500 ° C. or higher and 1200 ° C. or lower.

  (28) The method for producing a glass ceramic according to any one of (25) to (27), further comprising an etching step of performing dry etching and / or wet etching on the glass ceramic.

According to the present invention, by setting the composition of the glass within a predetermined range, one or more selected from R _0.5 Ti ₂ (PO ₄ ) ₃ and these solid solutions, and any one of TiO ₂ and this solid solution. Or the photocatalyst crystal | crystallization of the inorganic titanium compound including both becomes easy to precipitate. Since this crystal phase is uniformly deposited on the inside and the surface of the glass, there is no problem of peeling of the surface, and even if the surface is scraped, the photocatalytic performance is not inferior, and the ceramic glass ceramics having excellent durability, and its manufacturing method Can be obtained.

In addition, according to the method for producing glass ceramics of the present invention, one or more selected from R _0.5 Ti ₂ (PO ₄ ) ₃ and their solid solutions in the glass by controlling the composition of raw materials and the heat treatment temperature, and Since crystals containing TiO ₂ and / or both of these solid solutions can be produced, it has excellent photocatalytic activity without using special equipment for handling fine photocatalytic crystal powder, and photocatalytic functionality Glass ceramics useful as a raw material can be easily produced on an industrial scale.

It is an XRD pattern about the glass ceramic molded object of Example 1 of this invention. It is a graph showing the decomposition activity index | exponent before and behind an etching about the glass-ceramic molded object of Example 3 of this invention.

  The reason why the crystal phase and the components contained in the glass ceramic of the present invention are limited as described above will be described below. The description of the content of each component is expressed in mol% based on oxide unless otherwise specified. It is assumed that all anionic components in the glass ceramics are oxygen, and when considering only the content of the cation component, all of the cation component is made of an oxide combined with oxygen that balances the charge. And each component contained in the glass is expressed by the mole fraction of oxides × 100.

  The glass ceramic in the present invention is a material obtained by precipitating a crystalline phase in a glass phase by heat-treating the glass, and not only a material composed of a glass phase and a crystalline phase, but also the glass phase is entirely a crystalline phase. In other words, a material having a crystal amount (crystallinity) in the material of 100 wt% may be included. Engineering ceramics and ceramic sintered bodies obtained from commonly used powders are difficult to become pore-free fully sintered bodies. Therefore, the glass ceramics of the present invention can be distinguished from those glass ceramics by the presence of such pores (for example, porosity). Glass ceramics can be used as an effective means for producing desired crystals in the production of a photocatalytic material because the crystal grain size, the type of precipitated crystals, and the degree of crystallization can be controlled by controlling the crystallization process.

The glass ceramic of the present invention contains at least one selected from R _0.5 Ti ₂ (PO ₄ ) ₃ and a solid solution thereof, and TiO ₂ and either or both of the solid solutions (wherein R is 1 or more types selected from Be, Mg, Ca, Sr and Ba). By including these crystals, the glass ceramic of the present invention can be provided with a photocatalytic function.

The glass ceramic of the present invention preferably contains a crystal phase of TiO ₂ or a solid solution thereof. TiO ₂ is not only superior in photocatalytic properties, but also has a chemically stable property that is not affected by most acids, bases, and organic solvents, and is safe for the human body. It is the component used. As crystal forms of TiO ₂ used industrially, a rutile type, anatase type, and brookite type are known. In order to provide high photocatalytic properties, anatase type, rutile type are used. It is preferable to contain 1 or more types of titanium oxide of the group which consists of a type | mold and a brookite type. Brookite-type crystals exhibit high photocatalytic properties even in weak light, but their crystal structure is unstable and it is difficult to obtain them as a single phase, and they often precipitate in a mixed phase with anatase type. In order to develop a photocatalytic function in a stable state, the TiO ₂ crystal is preferably anatase and / or rutile, particularly anatase. The solid solution of TiO ₂ is not limited in type, and examples thereof include Ti _1-x Zr _x O ₂ .

In addition to the crystal, the glass ceramic of the present invention preferably has a crystal of an alkaline earth metal titanium phosphate composite salt. These have a NASICON type structure, and when a TiO ₂ crystal phase is simultaneously contained, a higher photocatalytic effect can be found. Among them, the effect of R _0.5 Ti ₂ (PO ₄ ) ₃ is particularly remarkable. Moreover, since the band gap energy can be adjusted by using these solid solutions, it is possible to improve the response to light. A solid solution means a state in which two or more kinds of metal solids or non-metal solids are dissolved in each other at an atomic level to form a uniform solid phase as a whole, and may be called a mixed crystal. Depending on how the solute atoms permeate, there are interstitial solid solutions in which elements smaller than the gaps in the crystal lattice enter, and substitutional solid solutions in which they replace the parent phase atoms. The glass ceramic of the present invention preferably contains either or both of R _0.5 Ti ₂ (PO ₄ ) _{3 and a} solid solution thereof. Among these, Mg _0.5 Ti ₂ (PO ₄ ) ₃ particularly contributes greatly to the decomposition activity index described later, so it is more preferable to contain it. Hereinafter, in the present specification, the crystals having the above-mentioned photocatalytic properties and solid solutions thereof are collectively referred to as “photocatalytic crystals”.

  The amount of the crystal phase with respect to the entire glass ceramic of the present invention can be freely selected in the range of 1.0% to 95% by volume according to the purpose of use, such as placing importance on transparency or giving priority to photocatalytic properties. it can. The amount of crystal phase precipitated from the glass is controlled by controlling the heat treatment conditions. If the amount of crystal phase is large, the photocatalytic function tends to increase, but the amount of crystals other than the target one increases, it becomes difficult to process, and the transparency that is important depending on the application may decrease. Therefore, the amount of the crystal phase is preferably in the range of 95% or less by volume ratio, more preferably in the range of 93% or less, and most preferably 90% or less. On the other hand, if the amount of the crystal phase is small, effective photocatalytic properties cannot be obtained. Therefore, the amount of the crystal phase is preferably 1% or more by volume, more preferably 3% or more, and most preferably 5% or more. preferable.

The glass ceramic of the present invention preferably contains a TiO ₂ component in the range of 15.0 to 95.0%. The TiO ₂ component is an indispensable and indispensable component for crystallizing and precipitating from the glass as a crystal of TiO ₂ or a crystal of a compound with phosphorus or an alkaline earth metal to bring about photocatalytic properties. In particular, when the content of the TiO ₂ component is 15.0% or more, the photocatalytic crystal is likely to precipitate, and the amount of the photocatalytic crystal in the glass ceramic is increased, so that desired photocatalytic characteristics can be ensured. . On the other hand, when the content of the TiO ₂ component exceeds 95.0%, vitrification becomes very difficult. Therefore, the content of the TiO ₂ component with respect to the total amount of the glass ceramic material in the oxide conversion composition is preferably 15.0%, more preferably 25.0%, most preferably 30.0%, and preferably 95%. 0.0%, more preferably 85.0%, and most preferably 80.0%. The TiO ₂ component can be introduced into the glass ceramic using, for example, anatase type, rutile type or brookite type TiO ₂ as a raw material.

The SiO ₂ component is a component that constitutes a glass network structure and improves the stability and chemical durability of the glass, and is present in the vicinity of the photocatalytic crystal on which Si ⁴⁺ ions are deposited, contributing to the improvement of the photocatalytic activity. It is a component and can be optionally added to the glass ceramic of the present invention. However, when the content of the SiO ₂ component exceeds 70.0%, the meltability of the glass is deteriorated, and the photocatalytic crystal is hardly precipitated. Therefore, the content of the SiO ₂ component with respect to the total amount of the glass ceramic material with an oxide conversion composition is preferably 70.0%, more preferably 50.0%, and most preferably 30.0%. SiO ₂ component may be incorporated in the glass ceramic is used as a raw material such as _{SiO 2, K 2 SiF 6,} Na 2 SiF 6 or the like.

The P ₂ O ₅ component constitutes a network structure of glass and is a useful component for incorporating more TiO ₂ component into the glass, and can be arbitrarily added to the glass ceramic of the present invention. Moreover, since it becomes possible to precipitate a photocatalytic crystal at a lower heat treatment temperature by containing the P ₂ O ₅ component, one or more members of the group consisting of anatase type, rutile type and brookite type having high photocatalytic activity can be obtained. TiO ₂ crystals, particularly anatase TiO ₂ crystals and NASICON type R _0.5 Ti ₂ (PO ₄ ) ₃ crystals can be easily formed. However, when the content of the P ₂ O ₅ component exceeds 70.0%, the photocatalytic crystal is hardly precipitated. Therefore, the content of the P ₂ O ₅ component with respect to the total amount of the glass ceramic material having an oxide conversion composition is preferably 70.0%, more preferably 60.0%, and most preferably 50.0%. _Further, by incorporating the P 2 _{O 5} component, the crystal of TiO ₂ and _{R 0.5 Ti 2 (PO 4)} 3 is easily more _{precipitation,} the content of P 2 _{O 5} component is at least 5% More preferably, the lower limit is 10%, and most preferably 20%. For example, Al (PO ₃ ) ₃ , Ca (PO ₃ ) ₂ , Ba (PO ₃ ) ₂ , Na (PO ₃ ), BPO ₄ , H ₃ PO _4, or the like can be introduced into the glass ceramic as a raw material. .

The B ₂ O ₃ component is a component that constitutes a glass network structure and improves the stability of the glass ceramic, and can be optionally added. However, when the content exceeds 70%, the tendency for the photocatalytic crystals to hardly precipitate is increased. Therefore, the content of the B ₂ O ₃ component is preferably 70%, more preferably 40%, still more preferably 25.0%, and most preferably 15.0% with respect to the total amount of glass ceramics having an oxide equivalent composition. The upper limit. B ₂ O ₃ component may be incorporated in the glass ceramics used as the material for example _{H 3 BO 3, Na 2 B} 4 O 7, Na 2 B 4 O 7 · 10H 2 O, the BPO ₄ and the like.

The GeO ₂ component is a component having a function similar to that of the above-described SiO ₂ and contributes to the stability of the molten glass. Although it is an optional component that can be added to adjust the refractive index and viscosity of the mother glass member, it is a rare mineral resource and is expensive, so it preferably does not exceed 10%, more preferably 5% or less, most preferably none Does not contain.

The glass ceramic of the present invention preferably contains one or more components selected from SiO ₂ component, P ₂ O ₅ component, B ₂ O ₃ component, and GeO ₂ component in a total range of 1 to 70%. . These are glass-forming oxides and are important components for obtaining glass. If the total amount is less than 1%, there is a high possibility that glass cannot be obtained. A more preferred amount is 10% or more, and a most preferred amount is 25% or more. On the other hand, if the amount exceeds 70%, the TiO ₂ crystal phase is difficult to precipitate. Therefore, the content is preferably 70% or less, more preferably 60% or less, and most preferably 50% or less.

The BeO component is a component that improves the meltability and stability of glass, and lowers the glass transition temperature to lower the heat treatment temperature, and is one of the group consisting of anatase type, rutile type and brookite type with high photocatalytic activity. It is a component that facilitates the formation of the above TiO ₂ crystals, particularly anatase TiO ₂ crystals and NASICON type R _0.5 Ti ₂ (PO ₄ ) ₃ crystals, and is a component that can be optionally added to the glass ceramics of the present invention. . However, when the content of the BeO component exceeds 50%, the stability of the glass is deteriorated, and the precipitation of the photocatalytic crystal becomes difficult. Therefore, the upper limit of the content of the BaO component with respect to the total amount of glass ceramics having an oxide conversion composition is preferably 50%, more preferably 30%, and most preferably 20%.

The MgO component is a component that improves the meltability and stability of glass, and lowers the glass transition temperature to lower the heat treatment temperature, and is one of the group consisting of anatase type, rutile type and brookite type with high photocatalytic activity. It is a component that facilitates the formation of the above TiO ₂ crystals, particularly anatase TiO ₂ crystals and NASICON type R _0.5 Ti ₂ (PO ₄ ) ₃ crystals, and is a component that can be optionally added to the glass ceramics of the present invention. . However, if the content of the MgO component exceeds 50%, the stability of the glass is deteriorated, and it is difficult to deposit photocatalytic crystals. Accordingly, the upper limit of the content of the MgO component with respect to the total amount of the glass ceramic material having an oxide conversion composition is preferably 50%, more preferably 30%, and most preferably 20%. The MgO component can be contained in the glass ceramic using, for example, MgCO ₃ , MgF ₂ or the like as a raw material.

The CaO component is a component that improves the meltability and stability of the glass, and lowers the glass transition temperature to lower the heat treatment temperature, and is one of the group consisting of anatase type, rutile type and brookite type with high photocatalytic activity. It is a component that facilitates the formation of the above TiO ₂ crystals, particularly anatase TiO ₂ crystals and NASICON type R _0.5 Ti ₂ (PO ₄ ) ₃ crystals, and is a component that can be optionally added to the glass ceramics of the present invention. . However, if the content of the CaO component exceeds 50%, the stability of the glass is deteriorated, and the photocatalytic crystals are difficult to precipitate. Therefore, the upper limit of the content of the CaO component with respect to the total amount of glass ceramics having an oxide conversion composition is preferably 50%, more preferably 30%, and most preferably 25%. The CaO component can be contained in the glass ceramic using _, for example, CaCO _3, CaF ₂ or the like as a raw material.

The SrO component is a component that improves the meltability and stability of glass, and lowers the glass transition temperature to lower the heat treatment temperature, and is one of the group consisting of anatase type, rutile type and brookite type with high photocatalytic activity It is a component that facilitates the formation of the above TiO ₂ crystals, particularly anatase TiO ₂ crystals and R _0.5 Ti ₂ (PO ₄ ) ₃ crystals, and can be optionally added to the glass ceramics of the present invention. However, when the content of the SrO component exceeds 50%, the stability of the glass is deteriorated, and the precipitation of the photocatalytic crystal becomes difficult. Therefore, the upper limit of the SrO component content is preferably 50%, more preferably 30%, and most preferably 20% with respect to the total amount of glass ceramics having an oxide equivalent composition. The SrO component can be contained in the glass ceramic using, for example, Sr (NO ₃ ) ₂ , SrF ₂ or the like as a raw material.

The BaO component is a component that improves the meltability and stability of glass, and lowers the glass transition temperature to lower the heat treatment temperature, and is one of the group consisting of anatase type, rutile type and brookite type with high photocatalytic activity. It is a component that facilitates the formation of the above TiO ₂ crystals, particularly anatase TiO ₂ crystals and R _0.5 Ti ₂ (PO ₄ ) ₃ crystals, and can be optionally added to the glass ceramics of the present invention. However, when the content of the BaO component exceeds 50%, the stability of the glass is deteriorated, and the precipitation of the photocatalytic crystal becomes difficult. Therefore, the upper limit of the content of the BaO component with respect to the total amount of glass ceramics having an oxide conversion composition is preferably 50%, more preferably 30%, and most preferably 20%. The BaO component can be contained in the glass ceramic using, for example, BaCO ₃ , Ba (NO ₃ ) ₂ or the like as a raw material.

The ZnO component is a component that improves the meltability and stability of glass, and lowers the glass transition temperature to lower the heat treatment temperature, and is one of the group consisting of anatase type, rutile type and brookite type with high photocatalytic activity. It is a component that facilitates the formation of the above TiO ₂ crystals, in particular anatase TiO ₂ crystals, and R _0.5 Ti ₂ (PO ₄ ) ₃ crystals, and can be optionally added to the glass ceramics of the present invention. However, when the content of the ZnO component exceeds 50%, the glass is liable to be devitrified and the stability of the glass is deteriorated, and the precipitation of the photocatalytic crystal becomes difficult. Therefore, the upper limit of the content of the ZnO component with respect to the total amount of the glass ceramic material having an oxide conversion composition is preferably 50%, more preferably 30%, and most preferably 20%. The ZnO component can be contained in the glass ceramic using, for example, ZnO, ZnF2 or the like as a raw material.

The total amount of the RO component (wherein R is one or more selected from the group consisting of Be, Mg, Ca, Sr, Ba, Zn) is R _0.5 Ti ₂ useful for providing photocatalytic performance. Since (PO ₄ ) ₃ crystal or a solid solution thereof is precipitated, it is preferably 0.1% or more, preferably 1.0% or more, more preferably 1.5% or more, and most preferably 5% or more. On the other hand, if the total amount of at least one component selected from the RO components is 50% or more, the stability of the glass is deteriorated and the photocatalytic crystals are difficult to precipitate, so that the catalytic activity of the glass ceramic is ensured. I can't. Accordingly, the total amount of at least one component selected from the RO components is preferably 50%, more preferably 40%, and most preferably 30% with respect to the total amount of glass ceramics having an oxide equivalent composition. . In addition, Mg _0.5 Ti ₂ (PO ₄ ) ₃ in the R _0.5 Ti ₂ (PO ₄ ) ₃ crystal greatly contributes to the decomposition activity index described later, and therefore contains the Mg component in the RO component. Is more preferable.

The Li ₂ O component is a component that improves the meltability and stability of the glass and makes it difficult to cause cracks in the glass ceramic after heat treatment, and lowers the glass transition temperature to lower the heat treatment temperature, and has high photocatalytic activity. It is a component that facilitates the formation of one or more TiO ₂ crystals of the group consisting of anatase type, rutile type and brookite type, particularly anatase type TiO ₂ crystal and NASICON type R _0.5 Ti ₂ (PO ₄ ) ₃ crystal. The glass ceramics of the present invention can be optionally added. However, if the content of the Li ₂ O component exceeds 50%, the stability of the glass is deteriorated, and the precipitation of the photocatalytic crystal becomes difficult. Therefore, the upper limit of the content of the Li ₂ O component with respect to the total amount of the glass ceramic material having an oxide conversion composition is preferably 50%, more preferably 30%, and most preferably 15%. The Li ₂ O component can be contained in the glass ceramic using, for example, Li ₂ CO ₃ , LiNO ₃ , LiF or the like as a raw material.

The Na ₂ O component is a component that improves the meltability and stability of the glass and makes it difficult to crack the glass ceramic after the heat treatment, and lowers the glass transition temperature to keep the heat treatment temperature lower, and has a high photocatalytic activity. It is a component that facilitates the formation of one or more TiO ₂ crystals of the group consisting of anatase type, rutile type and brookite type, particularly anatase type TiO ₂ crystal and NASICON type R _0.5 Ti ₂ (PO ₄ ) ₃ crystal. It is a component that can be optionally added to the glass ceramics of the present invention. However, when the content of the Na ₂ O component exceeds 50%, the stability of the glass is deteriorated, and the precipitation of the photocatalytic crystal becomes difficult. Therefore, the upper limit of the content of the Na ₂ O component with respect to the total amount of the glass ceramic material having an oxide equivalent composition is preferably 50%, more preferably 30%, and most preferably 15%. The Na ₂ O component can be contained in the glass ceramic using, for example, Na ₂ O, Na ₂ CO ₃ , NaNO ₃ , NaF, Na ₂ S, Na ₂ SiF ₆ or the like as a raw material.

The K ₂ O component is a component that improves the meltability and stability of the glass and makes it difficult to crack the glass ceramic after the heat treatment, and lowers the glass transition temperature to keep the heat treatment temperature lower, and has high photocatalytic activity. It is a component that facilitates the formation of one or more TiO ₂ crystals of the group consisting of anatase type, rutile type and brookite type, particularly anatase type TiO ₂ crystal and NASICON type R _0.5 Ti ₂ (PO ₄ ) ₃ crystal. It is a component that can be optionally added to the glass ceramics of the present invention. However, when the content of the K ₂ O component exceeds 50%, the stability of the glass is deteriorated, and the precipitation of the photocatalytic crystal becomes difficult. Therefore, the upper limit of the content of the K ₂ O component with respect to the total amount of the glass ceramic material having an oxide conversion composition is preferably 50%, more preferably 30%, and most preferably 15%. The K ₂ O component can be contained in the glass ceramic using, for example, K ₂ CO ₃ , KNO ₃ , KF, KHF ₂ , K ₂ SiF ₆ or the like as a raw material.

The Rb ₂ O component is a component that improves the meltability and stability of the glass and makes it difficult to cause cracks in the glass ceramic after the heat treatment, and lowers the glass transition temperature to lower the heat treatment temperature and has a high photocatalytic activity. It is a component that facilitates the formation of one or more TiO ₂ crystals of the group consisting of anatase type, rutile type and brookite type, particularly anatase type TiO ₂ crystal and NASICON type R _0.5 Ti ₂ (PO ₄ ) ₃ crystal. It is a component that can be optionally added to the glass ceramics of the present invention. However, when the content of the Rb ₂ O component exceeds 10%, the stability of the glass is deteriorated, and the precipitation of the photocatalytic crystal becomes difficult. Therefore, the upper limit of the content of the Rb ₂ O component with respect to the total amount of the glass ceramic material having an oxide conversion composition is preferably 10%, more preferably 8%, and most preferably 5%. The Rb ₂ O component can be contained in the glass ceramic using, for example, Rb ₂ CO ₃ , RbNO ₃ or the like as a raw material.

The Cs ₂ O component is a component that improves the meltability and stability of the glass and makes it difficult to crack the glass ceramic after the heat treatment, and lowers the glass transition temperature to keep the heat treatment temperature lower, and has a high photocatalytic activity. It is a component that facilitates the formation of one or more TiO ₂ crystals of the group consisting of anatase type, rutile type and brookite type, particularly anatase type TiO ₂ crystal and NASICON type R _0.5 Ti ₂ (PO ₄ ) ₃ crystal. It is a component that can be optionally added to the glass ceramics of the present invention. However, when the content of the Cs ₂ O component exceeds 10%, the safety of the glass is deteriorated, and the precipitation of the photocatalytic crystal becomes difficult. Therefore, the upper limit of the content of the Cs ₂ O component with respect to the total amount of the glass ceramic material with an oxide conversion composition is preferably 10%, more preferably 8%, and most preferably 5%. The Cs ₂ O component can be contained in the glass ceramic using, for example, Cs ₂ CO ₃ , CsNO ₃ or the like as a raw material.

The total amount of the Rn ₂ O component (wherein Rn is one or more selected from the group consisting of Li, Na, K, Rb, and Cs) is preferably in the range of 0 to 50%. Further, if these components are made 0.1% or more, the meltability and stability of the glass will be improved, so it is preferably 0.1% or more, more preferably 0.5% or more, and most preferably 1.5% or more. It is preferable to contain. On the other hand, when the total amount of at least one component selected from the Rn ₂ O component is 50% or less, the stability of the glass is improved and the photocatalytic crystal is likely to be precipitated. Can be secured. Therefore, the total amount of at least one component selected from the Rn ₂ O components is preferably 50%, more preferably 30%, and most preferably 20% with respect to the total amount of glass ceramics in oxide equivalent composition. And

Further, the glass ceramic of the present invention comprises an RO (wherein R is one or more selected from the group consisting of Be, Mg, Ca, Sr, Ba) and Rn ₂ O (wherein Rn is Li, Na , K, Rb, Cs, preferably selected from the group consisting of at least one component selected from the group consisting of K, Rb, and Cs). In particular, when the total amount of at least one component selected from the RO component and the Rn ₂ O component is 50% or less, the stability of the glass is improved, the glass transition temperature (Tg) is lowered, and cracking occurs. Glass ceramics which are difficult and have high mechanical strength can be obtained more easily. On the other hand, when the total amount of at least one component selected from the RO component and the Rn ₂ O component is more than 50%, the stability of the glass is deteriorated, and the precipitation of the photocatalytic crystal becomes difficult. Therefore, the total amount (Rn ₂ O + RO) with respect to the total amount of glass ceramics in terms of oxide composition is preferably 50%, more preferably 40%, and most preferably 30%. The lower limit of the total amount of the Rn ₂ O component and the RO component is 0.1%, preferably 1.0%, more preferably 1.5%, and most preferably 5%.

Al ₂ O ₃ component enhances the stability of glass and the chemical durability of glass ceramics, promotes the precipitation of photocatalytic crystals from glass, and improves the photocatalytic properties by dissolving Al ³⁺ ions in the TiO ₂ crystal phase. It is a component that contributes to the above and can be optionally added. However, when the content exceeds 20%, the melting temperature is remarkably increased and vitrification becomes difficult. Therefore, the upper limit of the content of the Al ₂ O ₃ component with respect to the total amount of glass ceramics having an oxide equivalent composition is preferably 20%, more preferably 12%, and most preferably 8%. Further, the lower limit when the Al ₂ O ₃ component is contained is preferably 0.1%, more preferably 0.5%, and most preferably 1%. The Al ₂ O ₃ component can be contained in the glass ceramic using, for example, Al ₂ O ₃ , Al (OH) ₃ , AlF ₃ or the like as a raw material.

The ZrO ₂ component is a component that enhances chemical durability, promotes the precipitation of photocatalytic crystals, and contributes to the improvement of photocatalytic properties when Zr ⁴⁺ ions are dissolved in the TiO ₂ crystal phase, and can be optionally added It is. However, when the content of the ZrO ₂ component exceeds 20.0%, vitrification becomes difficult. Therefore, the upper limit of the content of the ZrO ₂ component with respect to the total amount of the glass ceramic material having an oxide conversion composition is preferably 20%, more preferably 15%, and most preferably 10%. Further, the lower limit when the ZrO ₂ component is contained is preferably 0.1%, more preferably 0.5%, and most preferably 1%. The ZrO ₂ component can be contained in the glass ceramic using, for example, ZrO ₂ , ZrF ₄ or the like as a raw material.

SnO component promotes the precipitation of the photocatalyst crystals were easy to obtain a TiO ₂ crystal phase by suppressing the reduction of Ti ^4+, and a solid solution to TiO ₂ crystal phase be a component is effective in improving the photocatalytic properties In addition, when added together with Ag, Au or Pt ions, which will be described later, which has the effect of enhancing the photocatalytic activity, it acts as a reducing agent and indirectly contributes to the improvement of the photocatalytic activity. It is a possible ingredient. However, if the content of these components exceeds 10%, the stability of the glass is deteriorated, and the photocatalytic properties are liable to deteriorate. Therefore, the upper limit of the SnO component content is preferably 10%, more preferably 8%, and most preferably 5% with respect to the total amount of glass ceramics having an oxide equivalent composition. Further, the lower limit when the SnO component is contained is preferably 0.1%, more preferably 0.5%, and most preferably 1%. The SnO component can be contained in the glass ceramic using, for example, SnO, SnO ₂ , SnO ₃ or the like as a raw material.

The Bi ₂ O ₃ component is a component that increases the meltability and stability of glass, and the heat treatment temperature is lowered by lowering the glass transition temperature (Tg). Therefore, from anatase type, rutile type, and brookite type having high photocatalytic activity. It is a component that can easily form one or more types of TiO ₂ crystals, particularly anatase TiO ₂ crystals, and R _0.5 Ti ₂ (PO ₄ ) ₃ crystals, and can be optionally added. However, when the content of the Bi ₂ O ₃ component exceeds 20%, the stability of the glass is deteriorated, and the photocatalytic crystal is hardly precipitated. Therefore, the upper limit of the content of the Bi ₂ O ₃ component with respect to the total amount of the glass ceramic material having an oxide conversion composition is preferably 20%, more preferably 15%, and most preferably 10%. In particular, in the case where TiO ₂ crystals are precipitated while B ₂ O ₃ is used as the component constituting the main network of the glaze glass, Bi ₂ O ₃ / TiO ₂ is used to increase the stability of the glass and obtain the desired crystals. The content ratio of is preferably less than 0.12. The Bi ₂ O ₃ component can be contained in the glass ceramic using, for example, Bi ₂ O ₃ as a raw material.

The TeO ₂ component is a component that enhances the meltability and stability of the glass, and the heat treatment temperature is lowered by lowering the glass transition temperature (Tg). Therefore, the group consisting of anatase type, rutile type and brookite type having high photocatalytic activity These are components that can easily form one or more TiO ₂ crystals, particularly anatase TiO ₂ crystals, and R _0.5 Ti ₂ (PO ₄ ) ₃ crystals, and can be optionally added. However, when the content of the TeO ₂ component exceeds 20%, the stability of the glass is deteriorated, and the photocatalytic crystal is hardly precipitated. Accordingly, the content of the TeO ₂ component with respect to the total amount of the glass ceramic material having an oxide conversion composition is preferably 20%, more preferably 15%, and most preferably 10%. The TeO ₂ component can be contained in the glass ceramic using, for example, TeO ₂ as a raw material.

The Bi ₂ O ₃ component and / or TeO ₂ component is preferably not more than 20%, more preferably 15%, and most preferably not more than 10% in terms of the total amount of the two components.

The Nb ₂ O ₅ component is a component that enhances the meltability and stability of the glass, and is a component that improves photocatalytic properties when present in the vicinity of the photocatalytic crystal, and can be optionally added to the glass ceramic of the present invention. It is. However, when the content of the Nb ₂ O ₅ component exceeds 30%, the stability of the glass is remarkably deteriorated. Therefore, the upper limit of the content of the Nb ₂ O ₅ component with respect to the total amount of the glass ceramic material in oxide equivalent composition is preferably 30%, more preferably 20%, and most preferably 10%. The Nb ₂ O ₅ component can be contained in the glass ceramic using, for example, Nb ₂ O ₅ as a raw material.

The Ta ₂ O ₅ component is a component that enhances the stability of the glass, and is a component that improves photocatalytic properties when present in the vicinity of the photocatalytic crystal, and is a component that can be arbitrarily added. However, when the content of the Ta ₂ O ₅ component exceeds 30%, the stability of the glass is remarkably deteriorated. Therefore, the upper limit of the content of the Ta ₂ O ₅ component with respect to the total amount of glass ceramics having an oxide equivalent composition is preferably 30%, more preferably 20%, and most preferably 10%. The Ta ₂ O ₅ component can be contained in the glass ceramic using, for example, Ta ₂ O ₅ as a raw material.

The WO ₃ component is a component that improves the meltability and stability of the glass, and is a component that improves photocatalytic properties when present in the vicinity of the photocatalytic crystal, and can be optionally added. However, when the content of the WO ₃ component exceeds 30%, the stability of the glass is remarkably deteriorated. Therefore, the upper limit of the content of the WO ₃ component with respect to the total amount of the glass ceramic material having an oxide conversion composition is preferably 30%, more preferably 20%, and most preferably 10%. WO ₃ can be contained in glass ceramics using, for example, WO ₃ as a raw material.

The total amount of at least one component selected from Nb ₂ O ₅ component, Ta ₂ O ₅ component, and WO ₃ component is preferably 30% or less. When it is more than this, the stability of the glass ceramics is deteriorated, and it becomes impossible to form good glass ceramics. More preferably, the upper limit is 20%, and most preferably 10%. In addition, although it is possible to obtain glass ceramics having high photocatalytic properties even when none of the Nb ₂ O ₅ component, Ta ₂ O ₅ component, and WO ₃ component is contained, at least one selected from these components By making the total amount of the above components 0.1% or more, the photocatalytic properties of the glass ceramic can be further improved. Therefore, the total amount (Nb ₂ O ₅ + Ta ₂ O ₅ + WO ₃ ) with respect to the total amount of glass ceramics in the oxide conversion composition is preferably 0.1%, more preferably 0.5%, and most preferably 1.0. % Is the lower limit. Of these, the WO ₃ component is particularly effective in improving the photocatalytic properties.

Ln ₂ O ₃ component (wherein Ln is one or more selected from the group consisting of Y, Ce, La, Nd, Gd, Dy, and Yb) is a component that enhances the chemical durability of glass ceramics. It is a component that improves the photocatalytic properties by being present in the vicinity of the photocatalytic crystal, and can be optionally added. However, if the total content of the Ln ₂ O ₃ components exceeds 30%, the stability of the glass is significantly deteriorated. Accordingly, the total amount of at least one component selected from the Ln ₂ O ₃ components is preferably 30%, more preferably 20%, and most preferably 10% with respect to the total amount of glass ceramics having an oxide equivalent composition. The upper limit. The Ln ₂ O ₃ component includes, for example, La ₂ O ₃ , La (NO ₃ ) ₃ .XH ₂ O (X is an arbitrary integer), Gd ₂ O ₃ , GdF ₃ , Y ₂ O ₃ , YF ₃ , CeO as raw materials. ₂ , Nd ₂ O ₃ , Dy ₂ O ₃ , Yb ₂ O ₃ , Lu ₂ O _{3, and the} like can be contained in the glass ceramic.

M _x O _y component (wherein M is one or more selected from the group consisting of V, Cr, Mn, Fe, Co, and Ni, and x and y are each x: y = 2: (valence of M The minimum natural number satisfying the number) is dissolved in the TiO ₂ crystal phase or is present in the vicinity of the photocatalytic crystal, thereby contributing to the improvement of the photocatalytic properties and absorbing visible light of some wavelengths. It is a component that imparts an appearance color to the glass ceramic, and is an optional component in the glass ceramic of the present invention. In particular, when the total amount of at least one component selected from the M _x O _y components is 10% or less, the stability of the glass ceramic can be improved and the color of the appearance of the glass ceramic can be easily adjusted. . Therefore, the total amount of at least one component selected from the M _x O _y components is preferably 10%, more preferably 8%, and most preferably 5% with respect to the total amount of the glass ceramics having an oxide equivalent composition. The upper limit.

As ₂ O ₃ component and Sb ₂ O ₃ component are components for clarifying and defoaming glass ceramics, and when added together with Ag, Au, and Pt ions, which will be described later, and have the effect of enhancing photocatalytic activity, Since it plays the role of a reducing agent, it is a component that indirectly contributes to improving the activity of the photocatalyst and can be added arbitrarily. However, when the content of these components exceeds 5% in total, the stability of the glass is deteriorated, and the photocatalytic properties are liable to deteriorate. Therefore, the total content of As ₂ O ₃ component and / or Sb ₂ O ₃ component with respect to the total amount of glass ceramics in oxide equivalent composition is preferably 5%, more preferably 3%, most preferably 1%. The upper limit. As ₂ O ₃ component and Sb ₂ O ₃ component are, for example, As ₂ O ₃ , As ₂ O ₅ , Sb ₂ O ₃ , Sb ₂ O ₅ , Na ₂ H ₂ Sb ₂ O ₇ .5H ₂ O and the like as raw materials. It can be used and contained in glass ceramics.

The components for clarifying and defoaming glass ceramics are not limited to the above As ₂ O ₃ component and Sb ₂ O ₃ component, but for example, glass production such as CeO ₂ component and TeO ₂ component. Well-known fining agents and defoaming agents in the field, or a combination thereof can be used.

The glass ceramic of the present invention may contain at least one nonmetallic element component selected from the group consisting of an F component, a Cl component, a Br component, an S component, an N component, and a C component. These components are components that improve photocatalytic properties by being present in the vicinity of the photocatalytic crystal, and can be optionally added. However, when the content of these components exceeds 10% in total, the stability of the glass is remarkably deteriorated, and the photocatalytic properties are liable to deteriorate. Therefore, in order to ensure good characteristics, the total content of the nonmetallic element component with respect to the total mass of the glass ceramic of the oxide conversion composition is preferably 10%, more preferably 5%, and most preferably 3%. And These non-metallic element components are preferably introduced into the glass ceramic in the form of alkali metal or alkaline earth metal fluoride, chloride, bromide, sulfide, nitride, carbide or the like. Note that the content of the non-metallic element component in this specification is assumed to be made of an oxide in which all of the cation components constituting the glass ceramic are combined with oxygen that balances the charge, and the glass made of these oxides. The total mass is 100%, and the mass of the nonmetallic element component is expressed in mass% (extra divided mass% with respect to the oxide-based mass). The raw material of the nonmetallic element component is not particularly limited, but AlN ₃ , SiN ₄ or the like as the N component raw material, NaS, Fe ₂ S ₃ , CaS ₂ or the like as the S component raw material, ZrF ₄ or AlF ₃ as the F component raw material , NaF, CaF _2, etc., by using NaCl as a raw material for Cl component, AgCl, etc., NaBr or the like as a raw material of Br components, TiC as a raw material of component C, SiC or ZrC and the like, can be contained in the glass ceramic . In addition, these raw materials may be added integrally or may be added independently.

The glass ceramic of the present invention may contain at least one metal element component selected from Cu, Ag, Au, Pd, and Pt. Since these metal element components are present in the vicinity of the photocatalytic crystal and have an effect of improving the photocatalytic activity, they can be arbitrarily added. However, if the total content of these metal element components exceeds 5%, the stability of the glass is remarkably deteriorated, and good glass ceramics cannot be obtained. Therefore, the upper limit of the total content of the metal element component with respect to the total mass of the glass ceramic having an oxide conversion composition is preferably 5%, more preferably 3%, and most preferably 1%. These metal element components can be contained in glass ceramics using, for example, Cu ₂ O, Ag ₂ O, AuCl ₃ , PtCl ₄ or the like as a raw material. In addition, the content of the metal element component in this specification is assumed to be made of an oxide in which all the cation components constituting the glass ceramic are combined with oxygen sufficient to balance the charge, and the entire glass made of these oxides. The mass of the metal element component is expressed in terms of mass% (externally divided mass% with respect to the oxide-based mass).

  If necessary, other components can be added to the glass ceramic of the present invention as long as the properties of the glass ceramic are not impaired.

  However, lead compounds such as PbO, and components of Th, Cd, Tl, Os, Se, and Hg tend to refrain from being used as harmful chemical substances in recent years. Environmental measures are required until disposal after commercialization. Therefore, when importance is placed on the environmental impact, it is preferable not to substantially contain them except for inevitable mixing. As a result, the glass ceramics are substantially free of substances that pollute the environment. Therefore, the glass ceramics can be manufactured, processed, and discarded without taking any special environmental measures.

  The glass ceramic of the present invention preferably exhibits catalytic activity by light having a wavelength from the ultraviolet region to the visible region. Here, the light having a wavelength in the ultraviolet region referred to in the present invention is an invisible electromagnetic wave having a wavelength shorter than that of visible light and longer than that of soft X-ray, and the wavelength is in the range of approximately 10 to 400 nm. In addition, the light having a wavelength in the visible region referred to in the present invention is an electromagnetic wave having a wavelength that can be seen by human eyes among electromagnetic waves, and the wavelength is in a range of about 400 nm to 700 nm. When the surface of the glass ceramics is irradiated with light of wavelengths from the ultraviolet region to the visible region, the catalytic activity is expressed, so that dirt substances and bacteria attached to the surface of the glass ceramics are decomposed by oxidation or reduction reaction. Therefore, glass ceramics can be used for antifouling applications, antibacterial applications, purification applications such as water quality, and the like.

  In the glass ceramic of the present invention, the contact angle between the surface irradiated with light and the water droplet is preferably 10 ° or less. When the contact angle with water becomes small (that is, when wettability with water becomes high), water drops spread on the surface and a uniform water film is formed. Remove dirt. Thereby, since the surface of the glass ceramic exhibits hydrophilicity and has a self-cleaning action, the surface of the glass ceramic can be easily washed with water. In addition, since there is no irregular reflection of light due to minute water droplets, the clouding phenomenon is eliminated. The contact angle between the glass ceramic surface irradiated with light and the water droplet is more preferably 5 ° or less.

  The glass ceramic of the present invention is a material obtained by precipitating a crystal phase in a glass phase by heat-treating glass. Since the base material is glass, it can be processed into shaped bodies of various shapes by a conventional glass forming process. The shape of the molded body is appropriately designed according to the application and is not particularly limited. Examples thereof include a plate-shaped bulk body, a granular material such as beads, and a fibrous molded body.

  Moreover, since the glass processed into the desired shape according to a use turns into glass ceramics which have a photocatalyst crystal | crystallization by subsequent heat processing, the glass ceramics of this invention can become a photocatalyst which has various shapes. In particular, for example, by adopting the form of beads or fibers (fibers), the surface area is increased, so that the photocatalytic activity of the photocatalytic glass-ceramic shaped article can be further increased. Moreover, it can be used as a photocatalyst powder raw material in powder form. Since the glass of the present invention deposits fine photocatalytic crystals in the nano-order in the glass phase, it does not need to be fine particles as in the case of conventionally used photocatalyst raw materials, and is used by processing into a powder with a size that is easy to handle. can do. Hereinafter, as typical processing forms of the glass ceramic according to the present invention, beads and fibers will be described as examples.

[Photocatalytic glass ceramic beads]
The glass ceramic beads in the present invention relate to industrial beads, not decorative beads and handicraft beads. Industrial beads are mainly made of glass due to advantages such as durability, and generally refer to glass microspheres (diameters from several μm to several mm). Typical applications of industrial beads include road sign boards, paints used on road surface display lines, reflective cloths, filter media, and blasting abrasives. When beads are mixed and dispersed in road sign paint, reflective cloth, etc., light emitted from car lights etc. at night is reflected (retroreflected) to the original place through the beads, and visibility is improved. Such functions of the beads can be used for jogging wear, construction waistcoats, bike driver vests, and the like. When the glass ceramic beads of the present invention are used for these applications, the photocatalytic function makes it easy for the dirt attached to the label plate and the line to be decomposed and to easily flow down. Can be reduced. The glass ceramic beads of the present invention may be used by mixing with general glass beads or may be used alone. In order to obtain glass beads with higher retroreflective properties, the refractive index of the glass phase constituting the beads is preferably in the range of 1.8 to 2.1, particularly around 1.9. preferable.

  As other applications, industrial beads are used as filter media. Unlike sand and stones, beads are all spherical and have a high filling rate and can also calculate the porosity, so they are widely used alone or in combination with other filter media. The glass ceramic beads of the present invention have a photocatalytic function in addition to the original functions of such glass beads. In particular, it does not have a film or a coating layer, and exhibits photocatalytic properties as a single substance, so that there is no deterioration of catalytic activity due to peeling, and labor and time for replacement and maintenance can be saved. In addition, the filter member and the purification member using the photocatalyst function are often arranged adjacent to the light source member in the apparatus, but the photocatalyst glass ceramic beads are suitable because they can be easily stored in a container in the apparatus. Available to:

  Furthermore, since the photocatalytic glass ceramic beads are excellent in chemical stability and spherical, they do not damage the workpiece so much that they are used for blast polishing materials. Blasting refers to performing cleaning, beautification, peening, and the like by jetting granular material and causing it to collide with the surface to be processed. Since the photocatalytic glass ceramic beads of the present invention have a photocatalytic function in addition to the merits, simultaneous processing using photocatalytic reaction can be performed simultaneously with blasting.

  The particle size of the glass ceramic beads of the present invention can be appropriately determined according to the application. For example, when blended in a paint, the particle size can be 100-2500 μm, preferably 100-2000 μm. When used for a reflective cloth, the particle diameter can be 20-100 μm, preferably 20-50 μm. When used as a filter medium, the particle size can be 30 to 8000 μm, preferably 50 to 5000 μm. As the average particle diameter, for example, a value of D50 (cumulative 50% diameter) when measured by a laser diffraction scattering method can be used. Specifically, a value measured by a particle size distribution measuring apparatus MICROTRAC (MT3300EXII) manufactured by Nikkiso Co., Ltd. can be used. In addition, when the minimum diameter of beads exceeds 2000 μm, the average particle diameter can be obtained by a sieve analysis method defined in JIS A 120.

  Next, the manufacturing method of the glass ceramic bead of this invention is demonstrated. The method for producing beads of the present invention can include a melting step of mixing raw materials to obtain a melt thereof, and a molding step of forming a bead body using the melt or glass obtained from the melt. In addition, since the general manufacturing method of the glass ceramics of this invention can be applied to this specific example in the range which does not contradict, they are used suitably and the overlapping description is abbreviate | omitted.

(Melting process)
It can be carried out in the same manner as the above glass ceramic production method.

(Molding process)
Then, it shape | molds from the melt obtained at the melting process to a fine bead body. There are various methods for forming the bead body, which may be selected as appropriate. In general, the bead body can be formed by following the process of glass melt or glass → pulverization → particle size adjustment → spheronization. In the pulverization step, the cooled and solidified glass is pulverized, or the molten glass is poured into water and pulverized, or further pulverized by a ball mill to obtain granular glass. Then, adjust the particle size using a sieve, etc., reheat to form a spherical shape with surface tension, put it into a drum together with a powder material such as graphite, and shape it into a spherical shape with physical force while rotating, etc. There is a way. Or it can also take the method of making it spheroidize directly from a molten glass, without passing through a grinding | pulverization process. For example, molten glass is jetted into the air to spheroidize by surface tension, molten glass that exits from the outflow nozzle is cut into pieces with a member such as a rotating blade, and spheroidized. There is a method of making it spherical. Usually, the molded beads are commercialized after the particle size is adjusted again. In view of the viscosity of the glass at the molding temperature and the easiness of devitrification, the most suitable method may be selected from these methods.

  Although the glass ceramic beads of the present invention can exhibit high photocatalytic properties as they are, the specific surface area is increased by performing an etching process on the glass beads. It is possible to increase it further. Further, it is possible to obtain porous beads by controlling the solution used in the etching step and the etching time. The etching process can be performed in the same manner as described above.

[Photocatalytic glass fiber]
The fiber made of the glass ceramic of the present invention has the general properties of glass fiber. In other words, it has higher tensile strength and specific strength than conventional fibers, large elastic modulus and specific modulus, good dimensional stability, high heat resistance, nonflammability, good chemical resistance, etc. It has merits and can be used for various purposes. Moreover, since it has a photocatalytic crystal inside and on the surface of the fiber, it is possible to provide a fiber structure having photocatalytic properties in addition to the above-described merits and applicable to a wider range of fields. Here, the fiber structure refers to a three-dimensional structure in which fibers are formed as a woven fabric, a knitted fabric, a laminate, or a composite thereof, and examples thereof include a nonwoven fabric.

  There are curtains, sheets, wall-clothing cloths, insect screens, clothes, or heat insulating materials, etc. as applications that make use of heat resistance and nonflammability of glass fibers. The article can be given a deodorizing function and a dirt decomposing function by photocatalytic action, and the labor of cleaning and maintenance can be greatly reduced.

  Glass fiber is often used as a filter material due to its chemical resistance. However, the glass ceramic fiber according to the present invention is not only filtered, but also by a photocatalytic reaction, malodorous substances, dirt, bacteria in the object to be treated. Therefore, it is possible to provide a purification device and a filter having a more active purification function. Furthermore, since the deterioration of the characteristics due to the separation / detachment of the photocatalyst layer hardly occurs, it contributes to extending the life of these products.

  Next, the manufacturing method of the photocatalyst glass fiber of this invention is demonstrated. The method for producing a photocatalytic glass fiber of the present invention includes a melting step of mixing raw materials to obtain a melt thereof, and a spinning step of forming into a fiber shape using the melt or glass obtained from the melt. it can. In addition, since the general manufacturing method of the said glass ceramics can be applied to this specific example in the range which does not contradict, they are used suitably and the overlapping description is abbreviate | omitted.

(Melting process)
It can be carried out in the same manner as the above glass ceramic production method.

(Spinning process)
Next, it shape | molds into the photocatalyst glass fiber from the melt obtained at the melting process. The method for forming the fiber body is not particularly limited, and may be formed using a known method. When forming into a fiber (long fiber) of a type that can be continuously wound on a winder, it may be spun by a known DM method (direct melt method) or MM method (marble melt method), and the fiber length is several tens of centimeters. When forming into short fibers of a certain degree, a centrifugal method may be used, and the long fibers may be cut. What is necessary is just to select a fiber diameter suitably with a use. However, the thinner the fabric, the higher the flexibility and texture. However, the spinning production efficiency and cost increase, and conversely, if it is too thick, the spinning productivity is improved, but the workability and handleability are poor. Become. When making a textile product such as a woven fabric, the fiber diameter is preferably in the range of 3 to 24 μm, and when making a laminated structure suitable for uses such as a purification device and a filter, the fiber diameter should be 9 μm or more. preferable. Then, depending on the application, it can be made into a cotton shape, or a fiber structure such as roving or cloth can be made.

  Although the glass fiber can exhibit high photocatalytic properties as it is, the photocatalytic properties of the glass fiber can be further enhanced by performing an etching process on the glass fiber, since the specific surface area is increased. Is possible. Moreover, it is possible to obtain a porous body fiber by controlling the solution used for an etching process, and etching time. An etching process can be implemented similarly to the said glass ceramics.

  The glass ceramic of the present invention can be used as a photocatalytic functional glass ceramic member and / or a hydrophilic glass ceramic member for various machines, devices, instruments and the like. In particular, it is preferably used for applications such as tiles, window frames, building materials, and home appliances that require antifouling and antifogging functions. The glass ceramics of the present invention are excellent in moldability and the material itself has a photocatalytic function, so that it can be used in any shape without worrying about deterioration of characteristics. For example, it can be used as a purification filter or a deodorizing filter in the form of beads or fibers.

The beads or fibers made of the glass ceramic of the present invention obtained as described above can be easily applied to a substrate by preparing a slurry-like mixture by mixing with a solvent or the like used for a paint or the like. The slurry-like mixture of the present invention may be a mixture of only beads or fibers made of glass ceramics with a solvent or a binder, or a glass powder for glaze and / or glaze of the present invention in a solvent that is generally used. It may be a bead or fiber made of crystallized glass for use.

  Although it does not specifically limit as an inorganic binder, The thing of the property which permeate | transmits an ultraviolet-ray or visible light is preferable, for example, a silicate type binder, a phosphate type binder, an inorganic colloid type binder, an alumina, a silica, a zirconia And fine particles such as ash, lime, quartzite, feldspar, clay and frit used in glazes.

  As the organic binder, for example, a commercially available binder widely used as a molding aid for press molding, rubber press, extrusion molding, or injection molding can be used. Specific examples include acrylic resin, ethyl cellulose, polyvinyl butyral, methacrylic resin, urethane resin, butyl methacrylate, vinyl copolymer and the like. When using an organic binder, after apply | coating to a base material, you may remove these components through a degreasing process.

  As the solvent, for example, known solvents such as water, methanol, ethanol, propanol, butanol, isopropyl alcohol (IPA), acetic acid, dimethylformamide, acetonitrile, acetone, polyvinyl alcohol (PVA) can be used, but the environmental load is reduced. Alcohol or water is preferable because it can be used.

  In order to homogenize the slurry, an appropriate amount of a dispersant may be used in combination. The dispersant is not particularly limited, and examples thereof include hydrocarbons such as toluene, xylene, benzene, hexane, and cyclohexane, ethers such as cellosolve, carbitol, tetrahydrofuran (THF), dioxolane, acetone, methyl ethyl ketone, and methyl isobutyl ketone. And ketones such as cyclohexanone, and esters such as methyl acetate, ethyl acetate, n-butyl acetate and amyl acetate can be used, and these can be used alone or in combination of two or more.

  In addition to the above components, for example, an additive component for adjusting the curing rate and specific gravity can be blended with the slurry-like mixture of the present invention.

The content of glass ceramic beads or fibers in the slurry-like mixture of the present invention can be appropriately set according to the application. Therefore, the content of the glass in the slurry mixture is not particularly limited, but for example, from the viewpoint of exerting sufficient photocatalytic properties, it is preferably 50% by mass, more preferably 55% by mass, Preferably, 60% by mass is the lower limit, and from the viewpoint of ensuring fluidity and functionality as a glaze slurry, it is preferably 99% by mass, more preferably 80% by mass, and most preferably 65% by mass. .

Furthermore, the glaze of the present invention can be mixed with a crystalline photocatalyst powder (for example, TiO ₂ and WO ₃ ) for the purpose of further enhancing the photocatalytic activity. By adding these raw materials, a photocatalyst layer having more photocatalytic crystal phases can be more reliably produced.

In addition, in the manufacturing method of a slurry-like mixture, you may have the process of removing the aggregate of a bead and a fiber. As the particle size of the glass powder decreases, the surface energy tends to increase and tend to aggregate. If the glass powder is agglomerated, uniform dispersion cannot be achieved, and the desired photocatalytic activity may not be obtained. The removal of the aggregate can be performed by, for example, filtering the glaze. The glaze can be filtered using a filter medium such as a mesh having a predetermined mesh.

  The slurry-like mixture thus prepared can be suitably used as a material such as paint or glaze that provides a photocatalytic function.

  Next, the manufacturing method of the glass ceramic of this invention is demonstrated.

<First Embodiment>
1st Embodiment of the manufacturing method of the glass ceramics of this invention is a manufacturing method of the glass ceramics characterized by melt | dissolving a raw material composition mixture, obtaining the melt, and cooling and solidifying after that. More specifically, a predetermined starting material is uniformly mixed, put into a container made of platinum or refractory, and heated and held at a predetermined temperature of 1250 ° C. or higher in an electric furnace to prepare a melt. Thereafter, the melt is poured into a mold and solidified to obtain a target crystallized glass. Here, generation and growth of crystal nuclei occur in the process of cooling the melt. This technique is effective, for example, when a desired crystal phase is richly precipitated and the state of the glass melt is relatively unstable.

  Here, the melting temperature is preferably appropriately changed according to the type and amount of the composition to be mixed, but is generally preferably 1250 ° C. or higher, more preferably 1300 ° C. or higher, and most preferably 1350 ° C. or higher. Specifically, a predetermined starting material is uniformly mixed and placed in a container composed of a platinum crucible, a quartz crucible, or an alumina crucible, heated at a predetermined temperature of 1250 ° C. or higher in an electric furnace, and stirred and homogenized. Make it.

Then, while controlling the cooling rate of the melt, it is poured into a mold and cooled to a crystallization temperature region where generation and growth of crystal nuclei occur (first cooling step). Crystals are deposited on the glass after reaching the crystallization temperature region. By controlling the temperature of the region, the residence time in the temperature region, the cooling rate in the temperature region, etc., the target crystal The type, size and amount of crystal phase can be controlled (crystallization step). The crystallization temperature region may pass at a constant cooling rate, or may be maintained at a specific temperature for a certain time. Since the cooling speed and temperature greatly affect the formation of crystal phase and the crystal size, it is very important to control them precisely. When a desired crystal is obtained, it is cooled to a temperature outside the range of the crystallization temperature region to obtain a glass ceramic in which the crystal is dispersed (second cooling step).

Second Embodiment
The second embodiment of the glass ceramic manufacturing method of the present invention includes a melting step of mixing raw materials to obtain a melt, a cooling step of cooling the melt to obtain a glass body, and a temperature of the glass body. A reheating step for raising the temperature to a temperature range exceeding the glass transition temperature, a crystallization step for maintaining the temperature in the temperature range to produce crystals, and a recooling step for reducing the temperature again to obtain a crystal-dispersed glass. It is a manufacturing method of the glass ceramic which has.

(Melting process)
The melting step is a step of obtaining a melt by mixing raw materials having the above-described composition. More specifically, the raw materials are prepared so that each component of the glass ceramic is within a predetermined content range, uniformly mixed, and the prepared mixture is put into a platinum crucible, a quartz crucible or an alumina crucible, and electric Melt in a furnace at a temperature range of 1200 to 1600 ° C. for 1 to 24 hours, and homogenize with stirring to prepare a melt. In addition, the conditions for melting the raw material are not limited to the above temperature range, and can be appropriately set according to the composition and amount of the raw material composition.

(Cooling process)
A cooling process is a process of producing a glass body by cooling and vitrifying the melt obtained at the melting process. Specifically, a vitrified glass body is formed by flowing out the melt and appropriately cooling it. Here, the conditions for vitrification are not particularly limited, and may be appropriately set according to the composition and amount of the raw material. Moreover, the shape of the glass body obtained at this process is not specifically limited, Although it may be plate shape, a granular form, etc., it is preferable that it is plate shape at the point which can produce a glass body rapidly and in large quantities.

(Crystallization process)
The crystallization process is a process in which the temperature of the glass body is raised to a temperature region exceeding the glass transition temperature and held at that temperature for a predetermined time. By holding for a predetermined time in a predetermined temperature range in this crystallization step, R _0.5 Ti ₂ (PO ₄ ) ₃ crystal and TiO ₂ crystal having a desired size from nano to micron units, or a solid solution thereof can be obtained. Glass ceramics having photocatalytic properties can be more reliably produced because they can be uniformly deposited and dispersed inside the glass body.

In the above crystallization step, it is necessary to set the crystallization temperature in accordance with the glass transition temperature for each glass composition. Specifically, it is preferable to perform heat treatment in a temperature region higher by 10 ° C. than the glass transition temperature. Since the glass of the present invention has a glass transition temperature of 500 ° C. or higher, the lower limit of the preferable heat treatment temperature is 510 ° C., more preferably 600 ° C., and most preferably 650 ° C. On the other hand, if the heat treatment temperature becomes too high, the photocatalytic crystal phase tends to decrease and the photocatalytic properties are easily lost. Therefore, the upper limit of the heat treatment temperature is preferably 1200 ° C, more preferably 1100 ° C, and most preferably 1050 ° C. preferable. In particular, 1000 ° C. or lower is preferable in that R _0.5 Ti ₂ (PO ₄ ) ₃ crystals are precipitated simultaneously with one or more types of TiO _{2 in the} group consisting of anatase type, rutile type and brookite type. This temperature range is also applied to the crystallization temperature region that is passed or maintained when the glass ceramic is produced in the first embodiment.

(Etching process)
The glass body after crystals are formed by performing the crystallization process can exhibit high photocatalytic properties as glass ceramics as it is, but the crystal phase is obtained by performing an etching process on the glass ceramics. The glass phase around is removed, and the specific surface area of the crystal phase exposed on the surface increases, so that the photocatalytic properties of the glass ceramic can be further enhanced. Moreover, it is possible to obtain a porous body in which only the photocatalytic crystal phase remains by controlling the solution used in the etching step and the etching time. Here, examples of the etching step include dry etching and / or immersion in a solution. The acidic or alkaline solution used for the immersion is not particularly limited as long as the surface of the glass ceramic can be corroded, and may be, for example, an acid containing fluorine or chlorine (hydrofluoric acid, hydrochloric acid). This etching step may be performed by spraying hydrogen fluoride gas, hydrogen chloride gas, hydrofluoric acid, hydrochloric acid, or the like on the surface of the glass ceramic. The etching process can also be applied to a sintered body and a glass ceramic composite described below.

[Sintered glass ceramics]
When a powdery material made of glass (glass before crystallization) as a glass ceramic precursor according to the present invention is sintered and solidified, at least R _0.5 Ti ₂ (PO ₄ ) ₃ and these solid solutions are used. One or more selected, as well as TiO ₂ and a glass ceramic sintered body in which the solid solution is uniformly dispersed inside and on the surface can be obtained. The manufacturing method of a glass ceramic sintered body has a vitrification process, a crushing process, a forming process, and a sintering process as main processes. Details of each step will be described below.

(Vitrification process)
In the vitrification process, a predetermined raw material composition is melted and vitrified to produce a glass body. Specifically, the raw material composition is put into a container made of platinum or refractory, and the raw material composition is melted by heating to a high temperature. By vigorously cooling the resulting molten glass, a vitrified glass body is formed. The conditions for melting and vitrification can be performed in accordance with the above-described melting step and cooling step. Moreover, the shape of the glass body to produce is not specifically limited, For example, plate shape, a granular form, etc. may be sufficient.

(Crushing process)
In the pulverization step, the glass body is pulverized to produce pulverized glass. The particle diameter and shape of the crushed glass can be appropriately set according to the required accuracy of the shape and size of the molded body produced in the molding step. For example, when the pulverized glass is deposited on an arbitrary base material in the subsequent step and then sintered, the average particle diameter of the pulverized glass may be a unit of several tens of mm. On the other hand, when glass ceramics are molded into a desired shape or combined with other crystals, if the average particle size of the crushed glass is too large, it becomes difficult to mold, so the average particle size should be as small as possible. preferable. Therefore, the upper limit of the average particle size of the crushed glass is preferably 100 μm, more preferably 50 μm, and most preferably 10 μm. In addition, the value of D50 (cumulative 50% diameter) when measured by the laser diffraction scattering method can be used for the average particle diameter of pulverized glass, for example. Specifically, a value measured by a particle size distribution measuring apparatus MICROTRAC (MT3300EXII) manufactured by Nikkiso Co., Ltd. can be used.

  The method for pulverizing the glass body is not particularly limited, and can be performed using, for example, a ball mill, a jet mill or the like.

(Addition process)
In this method, you may perform the mixing process which mixes arbitrary components with respect to the granular material obtained at a grinding | pulverization process. Thereby, since content of each component contained in a glass ceramic sintered compact is fluctuate | varied, the sintered compact which has a desired characteristic can be formed. Here, the component to be added to the granule is not particularly limited, but the component that can enhance the function of the component by increasing the amount at the stage of the granule or the raw material composition of the molten glass because vitrification becomes difficult Although only a small amount can be added to the product, it is preferable to mix a component capable of promoting photocatalytic action. In particular, in order to increase the photocatalytic activity, it is preferable to mix powdery ZnO crystals, WO ₃ crystals, and / or TiO ₂ crystals.

(Molding process)
The forming step is a step of forming crushed glass to which a desired additive is added into a formed body having a desired shape. In order to obtain a desired shape, it is preferable to use press molding in which crushed glass is put into a mold and pressed. It is also possible to form the crushed glass by depositing it on a refractory. In this case, a binder can also be used.

(Sintering process)
In the sintering step, the crow compact is heated to produce a sintered body. Thereby, the particles of the glass body constituting the molded body are bonded together, and at the same time, one or more selected from R _0.5 Ti ₂ (PO ₄ ) ₃ and these solid solutions, TiO ₂ and this solid solution are produced, and glass Ceramics are formed. For example, when a molded object is manufactured from the mixture which added the photocatalyst crystal to the ground glass, the crystal | crystallization which has more photocatalytic activity is produced | generated by glass ceramics. Therefore, higher photocatalytic activity can be obtained.

  Although the specific procedure of the sintering process is not particularly limited, the step of preheating the molded body, the step of gradually raising the molded body to a set temperature, the step of holding the molded body at a set temperature for a certain time, the molded body May be gradually cooled to room temperature.

The sintering conditions can be appropriately set according to the composition of the glass body constituting the molded body. In the sintering process, in order to generate crystals from glass, it is necessary to match conditions such as the heat treatment temperature with the crystallization conditions of the glass constituting the compact. If the sintering temperature is too low, a sintered body having a desired crystal cannot be obtained. Therefore, sintering at a temperature higher than at least the glass transition temperature (Tg) of the glass body is required. Specifically, the lower limit of the sintering temperature is not less than the glass transition temperature (Tg) of the glass body, preferably not less than Tg + 50 ° C., more preferably not less than Tg + 100 ° C., and most preferably not less than Tg + 150 ° C. On the other hand, if the sintering temperature is too high, the precipitation of crystals including TiO ₂ crystals, WO ₃ crystals, ZnO crystals, etc. is reduced, and the optional TiO ₂ crystals are transformed into rutile having a lower activity than the anatase type. There is a strong tendency for the photocatalytic activity to decrease significantly due to transfer or precipitation of crystals other than the intended one. Therefore, the upper limit of the sintering temperature is preferably Tg + 600 ° C. or less of the glass body, more preferably Tg + 500 ° C. or less, and most preferably Tg + 450 ° C. or less.

  Further, the lower limit of the sintering time needs to be set according to the sintering temperature, but it is preferable to set it short for a high temperature and long for a low temperature. Specifically, the lower limit is preferably 3 minutes, more preferably 20 minutes, and most preferably 30 minutes in that the sintering can be sufficiently performed. On the other hand, if the sintering time exceeds 24 hours, the target crystals may become too large or other crystals may be formed, and sufficient photocatalytic properties may not be obtained. Therefore, the upper limit of the sintering time is preferably 24 hours, more preferably 19 hours, and most preferably 18 hours. In addition, the sintering time mentioned here refers to the length of time during which the firing temperature is maintained at a certain level (for example, the set temperature) or more in the sintering process.

  The sintering step is preferably performed while exchanging air in, for example, a gas furnace, a microwave furnace, an electric furnace or the like. However, the present invention is not limited to this condition. For example, it may be performed in an inert gas atmosphere, a reducing gas atmosphere, an oxidizing gas atmosphere, or the like.

The glass ceramic sintered body formed by the sintering process includes one or more selected from R _0.5 Ti ₂ (PO ₄ ) ₃ and these solid solutions, and TiO ₂ and this solid solution in the crystal phase. Yes. In this case, it is more preferable that crystals comprising TiO _{2 of} anatase type or brookite type are included. By containing these crystals, the glass-ceramic sintered body can have a high photocatalytic function. Among them, in particular, anatase type titanium oxide (TiO ₂ ) has a higher photocatalytic function than a rutile type, so that a higher photocatalytic function can be imparted to the glass ceramic sintered body.

[Glass ceramic composite]
Moreover, the composite body provided with the functional layer which has photocatalytic activity on a base material can be made using the glass ceramics of this invention. This glass ceramic composite (hereinafter sometimes referred to as “composite”) includes a glass ceramic layer obtained by heat-treating glass to form crystals, and a substrate. Specifically, the ceramic layer is a layer made of an amorphous solid and a crystal. The glass ceramic layer is selected from 15 to 95% of a TiO ₂ component, a SiO ₂ component, a P ₂ O ₅ component, a B ₂ O ₃ component, and a GeO ₂ component with respect to the total amount of the oxide-converted composition. Containing 1% to 70% of components of more than one species, 0.1 to 50% of RO component (wherein R is one or more selected from Be, Mg, Ca, Sr, Ba, Zn), One or more selected from R _0.5 Ti ₂ (PO ₄ ) ₃ and solid solutions thereof, and TiO ₂ and a crystal phase containing the solid solution are uniformly dispersed inside and on the surface of the glass ceramic.

In the method for producing a glass-ceramic composite according to the present invention, a crushed glass obtained from a raw material composition is fired on a substrate, and at least mol% of TiO ₂ with respect to the total amount of oxide-converted composition. 15% to 95% of components, 1% to 70% of one or more components selected from SiO ₂ component, P ₂ O ₅ component, B ₂ O ₃ component, and GeO ₂ component, and RO component of 0.1 to 50 % (Wherein R is one or more selected from Be, Mg, Ca, Sr, Ba, Zn), and a step of forming a glass ceramic layer (firing step). In a preferred embodiment of the method of the present invention, a vitrification step in which the raw material composition is melted and vitrified to produce a glass body, a pulverization step in which the glass body is crushed to produce crushed glass, and the crushed glass on the substrate The baking process which forms a glass-ceramics layer by baking can be included.

  In the present embodiment, “pulverized glass” is obtained by pulverizing a glass body obtained from a raw material composition, and is obtained by pulverizing amorphous glass and glass having a crystal phase. It is used to include a pulverized ceramic product and a crystal phase precipitated in a pulverized glass product. That is, “ground glass” may or may not have a crystalline phase. When the pulverized glass has a crystal phase, the glass body may be manufactured by heat treatment to precipitate the crystal phase and then pulverized, or after the glass body is crushed and heat treated, the crystal phase in the crushed glass You may manufacture by precipitating. In the case where the “pulverized glass” does not contain a crystal phase, the crystal phase can be precipitated by disposing the pulverized glass on a substrate and controlling the firing temperature (crystallization treatment).

  Here, the crystallization treatment can be performed, for example, at each timing of (a) after the vitrification step and before the pulverization step, (b) after the pulverization step and before the firing step, and (c) at the same time as the firing step. Among these, from the viewpoints of easy sintering of the glass ceramic layer and no need for a binder, improvement of throughput due to simplification of the process, energy saving, and the like, the crystal in the firing is performed simultaneously with the firing step (c). It is preferable to perform the conversion treatment. However, when using a substrate having low heat resistance as the base material constituting the composite, (a) after the vitrification step and before the pulverization step, or (b) after the pulverization step and before the firing step, It is preferable to perform crystallization at the timing.

Hereinafter, details of each process will be described.
(Vitrification process)
In the vitrification process, a predetermined raw material composition is melted and vitrified to produce a glass body. Specifically, the raw material composition is put into a container made of platinum or refractory, and the raw material composition is melted by heating to a high temperature. By vigorously cooling the resulting molten glass, a vitrified glass body is formed. Here, the shape of the glass body is not particularly limited, and may be, for example, a plate shape or a granular shape.

(Crushing process)
In the pulverization step, the glass body is pulverized to produce pulverized glass. By producing the pulverized glass, the glass body has a relatively small particle size, which makes it easy to apply on the substrate. Moreover, it becomes easy to mix other components by setting it as pulverized glass. The particle diameter and shape of the pulverized glass can be appropriately set according to the type of base material and the surface characteristics required for the composite. Specifically, if the average particle size of the pulverized glass is too large, it becomes difficult to form a glass ceramic layer having a desired shape on the substrate. Therefore, the average particle size is preferably as small as possible. Therefore, the upper limit of the average particle size of the crushed glass is preferably 100 μm, more preferably 50 μm, and most preferably 10 μm. In addition, the value of D50 (cumulative 50% diameter) when measured by the laser diffraction scattering method can be used for the average particle diameter of pulverized glass, for example. Specifically, a value measured by a particle size distribution measuring apparatus MICROTRAC (MT3300EXII) manufactured by Nikkiso Co., Ltd. can be used.

  The method for pulverizing the glass body is not particularly limited, and can be performed using, for example, a ball mill, a jet mill or the like.

(Addition process)
By adding an arbitrary component to the crushed glass, an addition step of increasing the amount of the component can be included. This step is an optional step that can be performed after the pulverization step and before the molding step. This addition process can be implemented according to the addition process demonstrated with the manufacturing method of the said glass ceramic sintered compact.

(Baking process)
In the firing step, the composite is produced by placing the crushed glass on the substrate and then heating and firing. Thereby, the glass ceramic layer which has a crystal phase containing a photocatalyst crystal | crystallization is formed on a base material. Here, the specific procedure of the firing step is not particularly limited, but the step of placing the crushed glass on the base material, the step of gradually raising the temperature of the crushed glass placed on the base material to the set temperature, pulverization A step of holding the glass at a set temperature for a certain time and a step of gradually cooling the crushed glass to room temperature may be included.

(Arrangement on the substrate)
First, crushed glass is placed on a substrate. Thereby, a photocatalytic characteristic and hydrophilicity can be provided with respect to a wider base material. Although the material of the base material used here is not particularly limited, it is preferable to use, for example, an inorganic material such as glass or ceramic, a metal, or the like because it can be easily combined with the photocatalytic crystal.

  In order to arrange the crushed glass on the substrate, it is preferable to arrange the slurry containing the crushed glass on the substrate with a predetermined thickness and size. Thereby, the glass ceramic layer which has a photocatalytic characteristic can be easily formed on a base material. Here, the thickness of the glass ceramic layer to be formed can be appropriately set according to the application of the composite. It is one of the features of the method of the present invention that the thickness of the glass ceramic layer can be set in a wide range. From the viewpoint of giving sufficient durability so that the glass ceramic layer does not peel off, the thickness is preferably, for example, 500 μm or less, more preferably 200 μm or less, and most preferably 100 μm or less. Examples of the method for arranging the slurry on the substrate include a doctor blade method, a calendar method, a coating method such as spin coating and dip coating, a printing method such as inkjet, bubble jet (registered trademark), offset, a die coater method, and a spray. Method, injection molding method, extrusion molding method, rolling method, press molding method, roll molding method and the like.

  In addition, as a method of arrange | positioning pulverized glass on a base material, it is not restricted to the method of using the above-mentioned slurry, You may place the powder of pulverized glass directly on a base material. In addition, when the crushed glass to be placed on the base material already contains crystals by heat treatment, depending on the crystallinity, it is mixed with an organic or inorganic binder component, or a binder layer is interposed between the base material. You can also In this case, an inorganic binder is preferable in terms of durability against photocatalysis.

(Baking)
The firing conditions in the firing step can be appropriately set according to the composition of the glass body constituting the crushed glass, the type and amount of the mixed additive, and the like. Specifically, the atmosphere temperature at the time of firing can be controlled in the following two ways depending on the state of the crushed glass placed on the substrate.

  The first firing method is a case where a desired photocatalytic crystal has already been generated in the crushed glass disposed on the substrate, for example, when a crystallization treatment is applied to a glass body or crushed glass. Is mentioned. In this case, the firing temperature can be appropriately selected within a temperature range of 1100 ° C. or less in consideration of the heat resistance of the substrate. However, when the firing temperature exceeds 1100 ° C., the generated photocatalytic crystal is easily transferred to another crystal. Become. Therefore, the upper limit of the firing temperature is preferably 1100 ° C., more preferably 1050 ° C., and most preferably 1000 ° C.

  The second firing method is a case where the crushed glass disposed on the base material has not yet been crystallized and does not have photocatalytic crystals. In this case, it is necessary to perform crystallization treatment of glass simultaneously with firing. If the firing temperature is too low, a sintered body having a desired crystal phase cannot be obtained. Therefore, firing at a temperature higher than at least the glass transition temperature (Tg) of the glass body is required. Specifically, the lower limit of the firing temperature is the glass transition temperature (Tg) of the glass body, preferably Tg + 50 ° C., more preferably Tg + 100 ° C., and most preferably Tg + 150 ° C. On the other hand, if the firing temperature becomes too high, the crystal phase containing the photocatalytic crystals tends to decrease and the photocatalytic properties tend to disappear, so the upper limit of the firing temperature is preferably Tg + 600 ° C. of the glass body, more preferably Tg + 500 ° C. Yes, most preferably Tg + 450 ° C.

  Moreover, it is necessary to set baking time according to the composition of glass, baking temperature, etc. If the rate of temperature increase is slow, it may be only necessary to heat to the heat treatment temperature. However, as a guideline, it is preferable that the temperature is short when the temperature is high and long when the temperature is low. Specifically, the lower limit is preferably 3 minutes, more preferably 5 minutes, and most preferably 10 minutes from the viewpoint that crystals can be grown to a certain extent and a sufficient amount of crystals can be precipitated. On the other hand, if the heat treatment time exceeds 24 hours, the target crystals may become too large or other crystals may be formed, and sufficient photocatalytic properties may not be obtained. Therefore, the upper limit of the firing time is preferably 24 hours, more preferably 19 hours, and most preferably 18 hours. In addition, the baking time said here refers to the length of the period when the baking temperature is hold | maintained more than fixed (for example, the said setting temperature) among baking processes.

Tables 1 to 10 show the compositions and crystallization temperatures of the glass ceramic molded bodies of Examples 1 to 11 of the present invention, the types of crystal phases deposited on these glass ceramic molded bodies, and the decomposition activity index (nmol / L / min). It is shown in 2. It should be noted that the following examples are for illustrative purposes only, and the present invention is not limited to these examples.

  The glass ceramic molded bodies of Examples (No. 1 to No. 11) of the present invention are all oxides, hydroxides, carbonates, nitrates, fluorides, hydroxides, hydroxides corresponding to the raw materials of the respective components, After selecting high-purity raw materials used for ordinary glass such as metaphosphoric acid compounds and weighing them to the proportions of the compositions of Examples and Comparative Examples shown in Tables 1-2, uniformly mixing, Put into a platinum crucible, melt in an electric furnace for 1 to 24 hours in a temperature range of 1200 ° C to 1600 ° C depending on the melting difficulty of the glass composition, homogenize with stirring and blow out bubbles, etc. After the temperature was lowered and homogenized with stirring, it was cast into a mold and slowly cooled to produce a glass. About the obtained glass, after heating to the crystallization temperature described in each Example of Table 1-2, holding for the described time and performing crystallization, it cools from crystallization temperature and is the target crystal | crystallization. A glass ceramic having a phase was obtained.

  Here, the kind of the crystallized crystal phase of the glass ceramic molded body of Examples (No. 1 to No. 11) was identified with an X-ray diffractometer (manufactured by Philips, trade name: X'Pert-MPD).

  Among these, the decomposition activity index (nmol / l / min) of methylene blue was calculated | required about the sample of the sample 1-10 of the Example in which the photocatalytic characteristic was recognized based on Japanese Industrial Standard JISR1703-2: 2007.

More specifically, the decomposition activity index of methylene blue was determined by the following procedure.
A 0.020 mM methylene blue aqueous solution (hereinafter referred to as an adsorption solution) and a 0.010 mM methylene blue aqueous solution (hereinafter referred to as a test solution) were prepared.
Then, the surface of the sample and one opening of the quartz tube (inner diameter 10 mm, height 30 mm) are fixed with high vacuum silicone grease (manufactured by Dow Corning Toray) and adsorbed from the other opening of the quartz tube. The liquid was injected to fill the test cell with the adsorbent. Thereafter, the other opening of the quartz tube and the liquid surface of the adsorbing liquid are covered with a cover glass (manufactured by Matsunami Glass Industry Co., Ltd., trade name: white edge polished frost No. 1), and the light is not exposed to the glass. The adsorbed liquid was sufficiently adsorbed to the sample over 24 hours. About the adsorption liquid after adsorption | suction, the light absorbency with respect to the light of wavelength 664nm was measured using the spectrophotometer (The JASCO Corporation make, model number: V-650), and the light absorbency of this adsorption liquid was similarly measured about the test liquid. Adsorption was completed when the absorbance was greater.
At this time, from the values of absorbance (Abs (0)) and methylene blue concentration (c (0) = 10 [μmol / L]) measured for the test solution, the conversion coefficient K [μmol / L].
K = c (0) / Abs (0) (1)
Next, after removing the cover glass and replacing the liquid in the quartz tube with the test solution, the other opening of the quartz tube and the liquid surface of the adsorbing liquid were covered again with the cover glass, and ultraviolet rays of 1.0 mW / cm 2 were irradiated. And the light absorbency with respect to the light of wavelength 664nm after irradiating an ultraviolet-ray for 60 minutes, 120 minutes, and 180 minutes was measured.
From the value of absorbance Abs (t) measured t minutes after the start of ultraviolet light irradiation, the concentration C of the methylene blue test solution t minutes after the start of ultraviolet light irradiation using the following formula (2) (T) [μmol / L] was determined. Here, K is the conversion factor described above.
C (t) = K × Abs (t) (2)
A plot was created with C (t) determined as described above on the vertical axis and the irradiation time t [min] of ultraviolet rays on the horizontal axis. At this time, the slope a [μmol / L / min] of the straight line obtained from the plot was determined by the least square method, and the decomposition activity index R [nmol / L / min] was determined using the following equation (3).
R = | a | × 1000 (3)

  On the other hand, about the glass of the composition described in the Example (No. 3), the crystallization process was performed at the time and temperature described in Table 1 to form glass ceramics. This glass ceramic was immersed in a hydrofluoric acid solution (manufactured by Wako Pure Chemical Industries, Ltd.) having an HF concentration of 46% (mass percentage) for 3 minutes to carry out an etching process. The above methylene blue decomposition test was performed on the glass ceramics before and after the crystallization step and the etching step, and the decomposition activity index (nmol / l / min) before and after the crystallization step and the etching step was obtained.

On the other hand, the hydrophilicity of the glass ceramic molded body of Example (No. 11) was evaluated by measuring the contact angle between the sample surface and water droplets by the θ / 2 method. That is, water is dripped onto the surface of the glass ceramic after irradiation with UV-A (10 mW / cm ² ) ultraviolet rays, and the height h from the surface of the glass ceramic molded body to the top of the water drop and the water drop test piece are in contact with each other. The surface radius r was measured using a contact angle meter (DM501) manufactured by Kyowa Interface Science Co., Ltd., and the contact angle θ with water was determined from the relational expression θ = 2 tan ⁻¹ (h / r). .

As a result, as shown in Tables 1 and 2, the precipitated crystal phases of the glass ceramic molded bodies of the examples all have anatase-type TiO ₂ crystals with high photocatalytic activity, and R _0.5 Ti ₂ (PO ₄ ) ₃ crystals were included. This is because, in the XRD pattern for the glass-ceramic molded body of Example (No. 1) shown in FIG. 1, “● = TiO ₂ , □ = Mg _0.5 Ti, including the vicinity of the incident angle 2θ = 24 °. It is also clear from the fact that a peak occurs at the incident angle represented by “ ₂ (PO ₄ ) ₃ ”. For this reason, it was guessed that the glass-ceramic molded object of the Example of this invention has a high photocatalytic characteristic and hydrophilicity compared with the glass molded object of a comparative example.

And the glass-ceramic molded object of an Example (No.1-No.10) has a decomposition activity index | exponent of 3.0 nmol / l / min or more as shown in Tables 1-2, More specifically, 10.2 nmol. / L / min or more. For this reason, it became clear that the glass-ceramic molding of the Example of this invention has a desired photocatalytic characteristic.

As shown in FIG. 2, the decomposition activity index of the glass ceramic molded body of Example (No. 3) after the etching process was improved. Specifically, the decomposition activity index changed from 18.1 to 26.2, which was higher than the decomposition activity index before the etching step. Therefore, it became clear that the glass-ceramic molded body of the Example of this invention can obtain a higher photocatalytic characteristic, since a decomposition activity index | variation fluctuates by performing an etching process.

  Further, when the hydrophilicity of the glass ceramic molded body of Example 11 was evaluated, the contact angle with water before ultraviolet irradiation was 49 °, but the contact angle after 30 minutes of ultraviolet irradiation was 6.5 °. It was confirmed that the contact angle was 10 ° or less. Thereby, it became clear that the glass-ceramic molding of the Example of this invention has high hydrophilicity by ultraviolet irradiation.

  Moreover, the chemical durability (water resistance and acid resistance) of the glass ceramic molded bodies of Examples (No. 1 to No. 11) was prepared by crushing to a particle size of 425 to 600 μm and washing with methanol. Measured according to Japan Optical Glass Industry Association Standard “Measurement Method of Chemical Durability of Optical Glass” JOGIS06-2008.

  Water resistance is obtained by placing a glass ceramic sample in a platinum basket, immersing the platinum basket in a quartz glass round bottom flask containing pure water (pH 6.5-7.5), and in a boiling water bath for 60 minutes. It measured using the weight loss rate (%) of the glass sample after processing. Here, when the weight loss rate (wt%) is less than 0.05, it is class 1, when the weight loss rate is less than 0.05 to 0.10, it is class 2, and when the weight loss rate is less than 0.10 to 0.25. Class 3, when the weight loss rate is less than 0.25 to 0.60, class 4, when the weight loss rate is less than 0.60 to 1.10, class 5, and when the weight loss rate is 1.10 or more, class 6 The smaller the number of classes, the better the water resistance of the glass.

  On the other hand, the acid resistance is obtained by placing a glass ceramic sample in a platinum basket, immersing the platinum basket in a quartz glass round bottom flask containing a 0.01N nitric acid aqueous solution, and treating it in a boiling water bath for 60 minutes. It measured using the weight loss rate (%) of a glass sample. Here, when the weight loss rate (wt%) is less than 0.20, class 1, when the weight loss rate is less than 0.20 to 0.36, class 2, and when the weight loss rate is less than 0.35 to 0.65 Class 3, when the weight loss rate is less than 0.65 to 1.20, class 4 when the weight loss rate is less than 1.20 to 2.20, class 6 when the weight loss rate is 2.20 or more The smaller the number of classes, the better the acid resistance of the glass.

  As a result, the water resistance and acid resistance of the glass ceramic molded bodies of Examples (No. 1 to No. 11) were both first grade.

Therefore, in the glass ceramic molded body of the example of the present invention, one or more types of titanium oxide (TiO ₂ ) of the group consisting of anatase type, rutile type and brookite type, and R _0.5 Ti ₂ (PO ₄ ) ₃ Since the photocatalytic crystals of the inorganic titanium phosphate compound to be deposited easily and these crystals are uniformly dispersed in the glass, there is no loss of the photocatalytic function due to peeling, and a photocatalytic functional body having excellent durability can be obtained. It was confirmed.

Claims (28)

As a crystal phase, it has R _0.5 Ti ₂ (PO ₄ ) ₃ and at least one selected from these solid solutions, and TiO ₂ and either or both of these solid solutions, and in JIS R 1703-2: 2007 Glass ceramics having a decomposition activity index of methylene blue based on 3.0 nmol / L / min or more. (In the formula, R is at least one selected from Be, Mg, Ca, Sr, Ba, Zn) The glass ceramic according to claim 1, wherein the crystal phase contains one or more TiO ₂ selected from anatase type, rutile type and brookite type.   3. The glass ceramic according to claim 1, wherein the crystal phase is contained in a volume ratio of 1.0% to 99.0% with respect to the total volume of the glass ceramic. 15 to 95% of TiO ₂ component in mol% of oxide conversion composition,
One or more components selected from SiO ₂ component, P ₂ O ₅ component, B ₂ O ₃ component, and GeO ₂ component are 1% to 70%, RO component is 0.1 to 50%, (in the formula, R The glass ceramics according to any one of claims 1 to 3, comprising: one or more selected from Be, Mg, Ca, Sr, Ba, and Zn. 4 or described glass-ceramics claim 1 containing 0-50% of Rn ₂ O component in mole percent on the oxide composition in terms. 0-30% of _Al 2 _{O 3} component in mole percent on the oxide composition in terms of,
Ga ₂ O ₃ component 0-30%,
0-30% of In ₂ O ₃ component,
0 to 20% of ZrO ₂ component,
0 to 20% of SnO component,
Bi ₂ O ₃ component and / or TeO ₂ component 0-20%
0 to 30% of Nb ₂ O ₅ component and / or Ta ₂ O 5 component,
WO ₃ component 0-30%,
0-30% of MoO component,
0-30% of Ln ₂ O ₃ component (Ln is one or more selected from Y, Ce, La, Nd, Gd, Dy, Yb),
M _x O _y component 0 to 10% (M is at least one selected from V, Cr, Mn, Fe, Co, and Ni, and x and y are each x: y = 2: (valence of M)) The smallest natural number satisfying
As ₂ O ₃ component and / or Sb ₂ O ₃ component 0-5%,
The glass ceramic according to claim 1, which is contained. In the externally divided mass% with respect to the total amount of glass of oxide standard composition,
The glass ceramic according to any one of claims 1 to 6, comprising 0.01 to 10% of one or more non-metallic element components selected from F, Cl, Br, S, N, and C. In the externally divided mass% with respect to the total amount of glass of oxide standard composition,
The glass ceramic according to any one of claims 1 to 7, comprising 0.001 to 5% of one or more metal element components selected from Cu, Ag, Au, Pd, Pt, Ru, Re, and Rh.   The glass ceramic according to any one of claims 1 to 8, wherein the catalytic activity is expressed by light having a wavelength from an ultraviolet region to a visible region.   The glass ceramic according to any one of claims 1 to 9, wherein a contact angle between a surface irradiated with light having a wavelength from an ultraviolet region to a visible region and a water droplet is 10 ° or less. The glass-ceramic molded object which consists of glass ceramics in any one of Claim 1 to 10.   A photocatalyst comprising the glass-ceramic molded article according to claim 11.   The photocatalyst according to claim 12, which has a granular or fiber form.   A slurry-like mixture containing the photocatalyst according to claim 13.   The photocatalyst member containing the photocatalyst in any one of Claim 12 to 14.   The purification apparatus containing the photocatalyst in any one of Claim 12 to 14.   A filter comprising the photocatalyst according to claim 12. A sintered body obtained by sintering crushed glass,
A sintered body comprising the glass ceramic according to claim 1 in the sintered body. The obtained glass body is mol% of the oxide conversion composition, TiO ₂ component is 15 to 95%, SiO ₂ component, P ₂ O ₅ component, B ₂ O ₃ component, and / or GeO ₂ component is 3% to 3%. A raw material composition prepared to contain 70% and 0.1 to 50% of RO component (wherein R is one or more selected from Be, Mg, Ca, Sr, Ba, Zn) A vitrification step for producing a glass body by melting and vitrifying,
Crushing step of crushing the glass body to produce a crushed glass;
A molding step of molding the crushed glass into a molded body having a desired shape;
The molded body is heated to be sintered, and at least one or both of R _0.5 Ti ₂ (PO ₄ ) ₃ and a solid solution thereof, and TiO ₂ and / or a solid solution thereof are contained in the glass. A sintering step of producing a sintered body by generating a crystalline phase including,
The sintered body according to claim 18, which is produced by a method comprising: The sintered body according to claim 19, wherein the method further includes a step of mixing ZnO crystal, WO ₃ crystal and / or TiO ₂ crystal with the pulverized glass.   It is a glass-ceramics composite which has a base material and the glass-ceramics layer provided on this base material, Comprising: The said glass-ceramics layer contains the glass ceramics in any one of Claim 1 to 10 characterized by the above-mentioned. A glass-ceramic composite.   The glass which produces | generates the crystal phase which has a photocatalytic activity from glass by heating, and becomes the glass ceramic in any one of Claim 1 to 10.   The glass according to claim 22, which has a granular or fiber form.   A slurry-like mixture containing the glass of claim 23.   The method for producing glass ceramics according to any one of claims 1 to 10, wherein the raw material mixture is melted by holding at a temperature of 1200 ° C or higher, and then cooled and solidified. It is a manufacturing method of the glass ceramics in any one of Claims 1-10,
A melting step of mixing raw materials to obtain a melt;
A cooling step of cooling the melt to obtain glass;
A reheating step of raising the temperature of the glass to a crystallization temperature region;
A crystallization step of maintaining the temperature within the crystallization temperature region to produce crystals;
A re-cooling step of obtaining the glass ceramic by lowering the temperature to outside the crystallization temperature region.   The method for producing glass ceramics according to claim 26, wherein the crystallization temperature region is 500 ° C or higher and 1200 ° C or lower.   The method for producing glass ceramics according to any one of claims 25 to 27, further comprising an etching step of performing dry etching and / or wet etching on the glass ceramics.