JP2001064038A - Glass material and glass fiber using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a glass material suitable as a carrier of a photocatalyst or the like, hardly being colored and having high ultraviolet ray transmissivity and to produce a glass fiber. SOLUTION: This glass material contains 35-60 wt.% SiO2, 4-30 wt.% Al203, 4-25 wt.% B2O3, 4-40 wt.% CaO, 0-10 wt.% oxide of an alkali metal and below 50 ppm by weight iron content in terms of Fe. The glass fiber is obtained by spinning this glass material in a spinning furnace.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a glass material and a glass fiber using the same. For more information,
The present invention is suitable, for example, for supporting a photocatalyst used for a photocatalyst filter or the like in a purification device or the like. It relates to a suitable glass fiber.

[0002]

2. Description of the Related Art Silicate glass, aluminosilicate glass, borosilicate glass, phosphate glass, fluorophosphate glass and the like are known as glass materials having severe restrictions on coloring. Such glass materials are required to have various properties in a wide variety of applications, and have various shapes. For example, glass materials that have severe restrictions on coloring of glass materials, or glass materials that highly transmit ultraviolet light are used. It is used as an ultraviolet transmitting glass. Specifically, it is used as a glass for supporting a photocatalyst, an EPROM cover glass, or spun into a glass fiber to be used as a photocatalytic fiber.

[0003] The photocatalyst technology mainly utilizes the strong oxidizing power generated under the light irradiation of the photocatalyst, and uses a gas processing device (a deodorizing device, air) for purifying the atmosphere, exhaust gas, and the like in a room, a vehicle, a cabin, or the like. Purifiers, gas removal equipment, exhaust gas purification equipment, etc.). A gas treatment filter used in a conventional gas treatment apparatus is a filter in which a thin film of a photocatalyst is carried on a surface of a filter material such as a flat shape or a honeycomb shape, and light from a light source is radiated to the filter material from the outside. I am trying to do it.

[0004] Here, the photocatalytic action in a metal having a photocatalytic action, to absorb light energy, superoxide anion (· O ₂ ^-), to generate ionized oxygen molecules such as hydroxyl radicals (· OH), its As a result, organic substances are oxidatively decomposed, and in recent years, attempts have been made actively to apply this photocatalysis to filters to apply them to various water treatments, air treatments, environmental purification, and the like.

On the other hand, a photocatalytic fiber as a filter material generally has a two-layer structure of a core and a clad, and the core corresponds to a monofilament type glass fiber.
The clad supported on the surface of the core corresponds to a photocatalyst. In such a photocatalytic fiber, ultraviolet rays necessary to promote a photocatalytic reaction must be supplied. That is, in the photocatalytic fiber, the refractive index of the cladding covering the core is larger than the refractive index of the core, and ultraviolet light incident from one end is transmitted through the photocatalytic fiber while leaking little by little from the side surface. The photocatalyst formed on the surface must be efficiently irradiated with ultraviolet light. Therefore, as a condition of the glass fiber used as the base material of the photocatalytic fiber, the transmittance in the ultraviolet region must be good. For that purpose, it is required that the glass material applied to the photocatalytic fiber cannot be colored glass, has a bubble number close to 0, and has no foreign matter or striae.

As a non-colored glass material, quartz glass, soda lime glass and the like are known. However, quartz is preferable as a substrate for supporting a photocatalyst without diffusion of impurities into the photocatalyst.
In addition to being impractical, the high softening temperature of glass makes it difficult to hot work into various shapes, and it is unavoidable that the cost will be further increased by forming a fiber. In addition, it has been reported that soda lime glass is not preferable because photocatalytic activity is deteriorated. This deterioration is considered to be caused by sodium ions in the glass being diffused into the photocatalyst and forming a compound when the photocatalyst is thermally oxidized. Therefore, it has been difficult to realize a glass material that exhibits a favorable transmittance and is suitably used as a base material of the glass for supporting a photocatalyst or the glass fiber for supporting a photocatalyst.

Next, a method of manufacturing a conventional general glass material will be described. Generally, in the production of a glass material, a raw material mixture is prepared by mixing raw materials such as hydroxides, carbonates, nitrates, sulfides, oxides, and nitrides so that a glass material having a desired composition is obtained. After that, it is melted. In melting glass, a two-stage method is usually employed.

That is, in the conventional method for producing a glass material, a step of melting a raw material mixture and vitrifying it and then forming the molten glass into a block is performed. A glass material is manufactured by a process of performing fining and homogenization to form a block of molten glass. As described above, in the conventional method for manufacturing a glass material, the vitrification step of the raw material mixture and the fining / homogenization step are performed in completely different melting steps.

As described above, in the conventional production of a glass material, a highly reactive batch material is melted using a silica crucible for vitrification in the first stage of melting. As a two-stage melting, melting is performed using a platinum crucible in order to obtain a glass material having a quality applicable to various uses. Since platinum is a stable material, it is a substance that does not itself elute into a glass material even when used as a crucible. When this platinum crucible is used for molding a glass material, erosion and penetration by the glass at the time of molding the glass are small, and reuse is possible.
It has the advantages that it is difficult to oxidize, is easy to process, can be used as a heating element when energized, is easy to control the temperature, and can be used at low cost in the long term.

FIG. 2 is a time-series graph showing an example of the relationship between time and temperature in a general manufacturing process of a glass material and a glass fiber. As shown in FIG. , First stage melting (point a in FIG. 2)
To point c), a second stage of melting (point c to point j in FIG. 2) to obtain a glass material, and then a spinning treatment (point j to point m in FIG. 2) to obtain a glass fiber The manufacturing method is adopted.

[0011] The first stage of melting is a step performed for the purpose of vitrifying a raw material mixture (hereinafter sometimes referred to as a batch raw material).
A high-purity raw material, which is a high-purity product and contains about 2% of impurities, is used. Then, a high-purity raw material, such as a hydroxide, a carbonate, a nitrate, a sulfide, an oxide, a nitride, a defoaming agent and the like are blended in a predetermined ratio to prepare a batch raw material. Usually, it is heated to about 1400 ° C. in a quartz crucible (hereinafter sometimes referred to as a silica crucible) (point a in FIG. 2), melted for about 7 to 9 hours (point b in FIG. 2), and vitrified. Is done. In the purification of the batch raw material, contact with a metal is generally avoided during blending and melting, and dust is prevented from being mixed in the storage and storage of the raw material and the batch raw material. At this time, since the glass material is heated and melted at a high temperature and vitrified, the reactivity of the batch material becomes very high, and gas components such as CO ₂ and NO ₂ are generated in the batch material in the vitrification process, and countless Bubbles are generated. Then, while stirring these foams while leaving them in the molten glass in the vitrification process, the glass is shaped (point b in FIG. 2), and the glass is quenched (point c in FIG. 2). A cullet-shaped glass block having a size of 1 cm × 1 cm is obtained.

The second-stage melting performed after the first-stage melting satisfies a predetermined standard arbitrarily determined for each application based on the glass block obtained by the first-stage melting. This is a step performed for the purpose of obtaining a quality glass material. That is, in the melting in the second stage, a series of glass material production steps of softening, fining and defoaming, stirring and homogenizing, and outflow and molding steps are performed in a platinum crucible.

In the second stage of melting,
The glass mass obtained in the first stage of melting is put into a platinum crucible (point c in FIG. 2) and heated to about 1400 ° C.
The glass block is softened over about 2-3 hours (point e in FIG. 2). Thereafter, the softened glass material is heated to about 1450 ° C. (point f in FIG. 2), defoamed and stirred for about 7 to 9 hours, and fining and homogenization are performed (point g in FIG. 2).
Then, the refined and homogenized molten glass is
After heating to 350 ° C. (point h in FIG. 2), and further degassing and stirring to clarify and homogenize, pour this into a mold,
It is molded (point i in FIG. 2). Then, it is cooled to obtain a cylindrical block-shaped glass block having a diameter of about 30 mm and a length of about 1000 mm (point j in FIG. 2). Next, in order to produce a glass fiber from the glass lump thus obtained, a spinning treatment is performed. First, the above glass mass is put into a spinning furnace and heated to about 1100 ° C. (point k in FIG. 2), and then the softened glass material is spun (point l in FIG. 2), and then rapidly cooled to obtain a glass fiber. (Fig. 2
Point m).

As described above, so far, the first
Using a silica crucible in the stage melting, the batch material is vitrified and formed once, and then contains a myriad of bubbles in the second stage melting for clarification and homogenization. Using the formed glass lump, it was softened and re-melted in a platinum crucible so that fining and homogenization could be performed. However, in such a method for producing a glass material, there is a problem that the obtained glass material is inevitably colored.

The glass that is usually melted must be vitrified at a high melting temperature for a long period of time, otherwise the devitrification resistance is poor and the internal transmittance of the glass material is reduced. In addition, the higher the vitrification temperature is, the easier the impurities in the raw material mixture are activated and colored, which also causes a reduction in external transmittance. Here, the internal transmittance is a transmittance that does not include surface reflection, and the external transmittance is a transmittance that includes surface reflection.

By the way, in the ultraviolet transmitting glass used for supporting the photocatalyst, the coloring of the glass material hinders the high transmittance of the ultraviolet light, and the bubbles, foreign matters and striae in the glass material also reduce the ultraviolet transmittance. It becomes a factor to lower. Moreover, for glass materials used as fibers,
Even if the melting temperature is lowered, not only glass melting with good devitrification resistance but also good viscoelasticity, mechanical strength and chemical durability are required. Further, the glass material for supporting the photocatalyst is required to have a matching thermal expansion coefficient with that of the photocatalyst.

As an inexpensive glass material having a low melting temperature,
So-called E glass is known. The E-glass is typically SiO ₂ 52 - 56 wt%, Al ₂ O ₃ 12~1
6 wt%, B ₂ O ₃ 8~13 wt%, CaO 16 to 2
It has a composition containing 5% by weight, 0 to 6% by weight of MgO and 0 to 3% by weight of an alkali metal oxide, and has a spinning temperature of about 12%.
It is about 00 ° C. and is widely used as a glass material of general glass fibers or glass fibers for fiber reinforcement. However, since E glass has no restriction on impurities and usually contains a considerable amount of iron, it is colored and has extremely poor ultraviolet transmittance, so that it cannot be used for applications requiring high ultraviolet transmittance.

[0018]

DISCLOSURE OF THE INVENTION The present invention overcomes the drawbacks of the conventional glass materials and glass fibers and has a low coloring and high ultraviolet transmittance which is suitable for supporting a photocatalyst and the like. An object of the present invention is to provide an inexpensive glass material having a low melting temperature and a glass fiber using the same.

[0019]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to achieve the above object, and as a result, a glass material having a specific composition and an iron content of a certain value or less has been obtained. They have found that the object can be achieved, and have completed the present invention based on this finding.

That is, according to the present invention, (1)
_{iO 2 35~60%, Al 2 O} 3 4~30%, B 2 O 3
4 to 25%, CaO 4 to 40% and alkali metal oxide 0 to 10%, and the iron content is Fe
(2) a glass material of the above (1) having a thickness of 10 mm and having an ultraviolet transmittance of 80% or more at a wavelength of 365 nm at a thickness of 10 mm; ₂ 49-56%, Al ₂ O
_{3 12~17%, B 2 O 3} 6~14% and CaO 1
The glass material of the above (1) or (2), containing 6 to 25%,
(4) The glass material of (1) to (3), wherein the total content of SiO ₂ , Al ₂ O ₃ and B ₂ O ₃ is 59 to 90% by weight, and (5) ₂ , Al ₂ O ₃ , B ₂ O ₃
And the glass material of (1) to (4), wherein the total content of CaO is 85 to 100%, and (6) as at least one other component selected from MgO, BaO, and SrO. , The content of which is% by weight,
0-8%, BaO 0-10% and SrO 0-10
A%, and the glass material of the total content thereof is 15% or less (1) to (5), (7) wt%, K ₂
The glass material of the above (1) to (6), which contains O 0 to 10%;
(8) PbO, ZrO ₂ , Ti
O ₂ , La ₂ O ₃ , P ₂ O ₅ , WO ₃ , Bi ₂ O ₃ , Ta ₂ O ₅ ,
_{Nb 2 O 5, Gd 2 O} 3 and F above containing at least one selected from among (1) a glass material to (7),

(9) As other components, As ₂ O ₃ ,
At least one selected from SnO ₂ and Sb ₂ O ₃
(10) The glass material of the above (1) to (8) containing a seed.
(A) a step of melting the raw material mixture into a glassy state, (B)
Step (A): a step of clarifying and homogenizing the glassy melt obtained in the step (A) without solidifying in a crucible made of a platinum-free material, and (C) cooling the molded article The melting of the raw material mixture in the above (1) to (9) and the raw material mixture in the step (11) (A) obtained by the step of obtaining a glass lump is performed in a crucible made of a material not containing platinum. (10) The glass material according to (10), wherein the steps (12), (A) and (B) are carried out in a reducing atmosphere, and (13) reduction. The above (1) wherein the atmosphere is formed by mixing a reducing agent into the raw material mixture or adding the reducing agent to the glassy melt in the step (A).
2) the glass material, (14) the glass material of (1) to (13) used for supporting a photocatalyst, and (15) the (1)
The present invention provides a glass fiber obtained by spinning the glass material of (14) in a spinning furnace, and (16) the glass fiber of (15) used for supporting a photocatalyst.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is intended for supporting a photocatalyst which is free from coloring, bubbles, foreign matter and striae, can achieve high internal transmittance and high external transmittance in the ultraviolet region, and has high solarization resistance. Has been developed as a suitable glass material. Further, the present invention has developed a glass fiber using the above glass material, which has high mechanical strength, is excellent in chemical durability, and is suitable for supporting a photocatalyst which can be manufactured with good moldability.

First, the solarization resistance will be described. Solarization is a phenomenon of blackening when glass is irradiated with ultraviolet light.To improve solarization resistance, conventionally, a small amount of a component having absorption in the ultraviolet region is added, and there is no absorption in the ultraviolet region. A composition that does not
However, the former cannot be applied for the purpose that the glass material of the present invention is an ultraviolet transmitting glass. Therefore, the improvement in solarization resistance can be achieved by using a black light that emits light only at a wavelength of around 365 nm and realizing a glass composition that does not absorb the wavelength of the light of the black light. .

Next, a glass material that can achieve the object of the present invention as described above, that is, a glass material that can achieve high external transmittance and high internal transmittance in the ultraviolet region will be described. As such a glass material, 30% of SiO ₂ is used.
Preferred examples include silicate glass, aluminosilicate glass, and borosilicate glass containing from 0 to 70% by weight and from 0 to 10% by weight of an alkali metal oxide.

The multi-component glass which is the glass material of the present invention comprises:
It is used as an ultraviolet transmitting glass or a glass with little coloring. The first condition is to transmit ultraviolet light at a high transmittance, and as described above, a glass composition having a wavelength of about 365 nm and a small absorption of the wavelength is realized. Must. In particular, the glass to be formed into a fiber is required to have excellent chemical durability. In other words, since the glass fiber has a large surface area, the contact area with the outside air increases as compared with the glass material.Accordingly, the probability of contact with corrosive components such as moisture in the atmosphere is large, so that the chemical durability is reduced. It is important to improve.

In general, when selecting a base glass component of a multi-component glass, three types of glasses, ie, SiO ₂ , P ₂ O ₅ , and B ₂ O ₃ , can be cited. In the present invention, by using SiO ₂ as a base glass component and containing 35 to 60% by weight of SiO ₂ in a glass material to adjust other components, chemical durability is good,
A glass composition that realizes a glass fiber obtained by spinning a glass material having good ultraviolet transmission properties, and thus a glass material having these characteristics, and manufacturing these glass materials and glass fibers without deteriorating the above-described characteristics. The manufacturing method of each was examined. Further, as such a glass material of the present invention, a basic functional property of not deteriorating the required photocatalytic activity, not coloring, capable of firmly adhering a highly active photocatalyst, and having good moldability can be achieved. The glass composition was studied. That is, in the present invention, SiO ₂ is the base glass component (35 to 60% by weight) and the alkali metal oxide is small (0 to 1%).
(0% by weight) Based on the premise that silicate glass is used, a glass material composition having little coloring, a high glass transition temperature, and good devitrification resistance was studied and selected.

However, as described above, when the alkali component is reduced to maintain the photocatalytic activity as described above, the chemical durability is further improved, but the glass material becomes a high melting point glass, and the glass material is manufactured. In addition, it must be melted at high temperature. However, high-temperature melting
There is a tendency to deteriorate the light transmission characteristics such as lowering the external transmittance and the internal transmittance of the glass material, and as a result, the glass material is colored, so that a glass material having a high transmittance of ultraviolet rays is obtained. Becomes difficult.

The coloring of a glass material of a multi-component glass containing SiO ₂ as a base glass component will be described with reference to FIG. 3 showing a spectral transmittance curve. FIG. 3 is a graph showing a different example of the spectral transmittance curve of the glass material, where the horizontal axis represents the wavelength (nm) and the vertical axis represents the transmittance (%). Here, the coloring degree ([lambda] 80 / [lambda] 5) is 700 nm from the rising wavelength using a glass material polished to a thickness of 10 ± 0.1 mm.
The spectral transmittance (including the reflection loss) in the wavelength range up to and including 10% is set to the wavelength showing the transmittance of 80% and 5%.
It is displayed in units.

FIG. 3 shows the characteristics of a silicate glass material manufactured using a high-purity batch material mixed with the above-mentioned commercially available high-purity material (99% or more) in order to transmit ultraviolet rays. Curve a is a theoretical curve for a glass material without coloring, and curve b is a silicate containing a coloring component produced by the method for producing a silicate glass material shown in FIG. 2 (conventional production method). It is a curve which shows the relationship between the actual wavelength and the transmittance | permeability in a salt glass material. In such a glass material, a transmittance curve appears on the short wavelength side, but the transmittance at a wavelength of 310 to 410 nm,
That is, the transmittance in the ultraviolet region is reduced,
The UV transmission characteristics of the glass material are reduced. Due to this phenomenon, it is assumed that the absorption of the wavelength by the trivalent iron ion (hereinafter referred to as Fe ³⁺ ) into the silicate glass material occurs near 365 nm, which is the wavelength region of the ultraviolet region.
This deterioration of the ultraviolet transmission property is caused by coloring of the silicate glass material, and therefore, it is considered that the platinum crucible used for melting in the conventional glass material manufacturing method is one of the causes. For this reason, in the above-mentioned silicate glass material, coloring in a glass material of a type having severe restrictions on coloring as in the present invention causes a decrease in transmittance in a glass material that needs to transmit ultraviolet rays. Since this is not allowed, the conventional method for manufacturing a glass material cannot be applied. Therefore, before selecting a more detailed composition in a silicate glass having a SiO ₂ content of 35 to 60% by weight and an alkali metal oxide of 0 to 10% by weight as described above, a method of manufacturing the glass material is required. Needs to be changed from the conventional one. In other words, in order to improve the conventional glass material manufacturing method, after preventing impurities from entering the atmosphere in the glass material manufacturing process, the glass material manufacturing process further restricted the amount of impurities to high purity. It is conceivable to use a batch raw material of the above or stop using the platinum crucible. Hereinafter, each of these matters will be considered.

First, the use of a high-purity batch raw material having a low content of impurities and thus iron impurities will be examined. In the glass lump obtained in the first stage of melting, even if the content of each component of the impurities mixed into the batch raw material is limited by using the batch raw material purified to a high purity, It is considered that impurities such as metals are mixed. Then, in the second stage of melting, the glass block is softened in a platinum crucible,
When defoaming and stirring can be performed on the glass material, the impurities are also activated, and platinum acts as a catalyst for the impurities, which may oxidize impurities in the molten glass material. . Therefore, by performing fining and homogenization at a high temperature using a platinum crucible, defoaming in the molten glass can be performed efficiently, but as described above, impurities such as iron are mixed even in trace amounts in the batch raw material. Therefore, when it is heated to a high temperature in a platinum crucible, it is oxidized by heat to produce Fe ³⁺ . As described above, since platinum, which is a crucible material, promotes the oxidizing action, there is a possibility that the platinum may be a coloring factor of the glass material.

That is, even when a high-purity batch material having a low iron impurity content is used, in addition to the environment in which a small amount of impurity iron contained in the batch material is thermally oxidized by high-temperature heating, Since the glass material is manufactured under a severe environment in which platinum, which is a crucible material, is a material that contributes to the oxidation reaction of iron, the problem that the glass material is easily colored is difficult to solve easily.

Next, consideration will be given to preventing impurities from entering the atmosphere in the glass material manufacturing process. This method is usually applied in the production of glass fibers, but not in the production process of glass materials. In the manufacturing process of the glass material described above, the batch raw material, the substance melted in the first stage of melting, the glass lump obtained in the first stage, the second
In the process of changing the substance that is being melted in the melting in the step and the glass lump obtained in the second step, it comes into contact with a substance (for example, a metal) other than the material contained in the glass material. That is, a crucible, a stirring rod, a melting atmosphere (air), a mold used for molding, a substance used for cooling, and the like come into contact in the glass material manufacturing process. In addition, when these substances come into contact with the high-temperature glass, they may be melted, whereby the glass material may be colored.

Next, the use of the platinum crucible will be considered. The merits of using a platinum crucible in the manufacturing process of a glass material have been described above, but considering the merit, it was considered that the use of a platinum crucible was essential. However, depending on the type of the glass material, for example, glass type F manufactured by HOYA-SCHOTT Co., Ltd.
In the melting of a lead-based glass material for producing a multi-component fiber for a light guide as in 2, an oxidation reaction occurs with respect to lead, that is, a component of the glass material itself. Further, when the temperature of the molten glass is raised to perform defoaming and homogenization at a high temperature, the glass material may be colored. Moreover, even if it is not a lead-based glass material such as the glass type F2, as described above, the crucible itself serves as a catalyst for accelerating the oxidation reaction only by heating the crucible at a high temperature, and thus contains a coloring component. It is difficult to avoid coloring in the production of glass materials and glass materials containing even trace amounts of metallic impurities to be colored. In the manufacturing process of such a glass material, refining,
From the viewpoint of homogenization, it is difficult to eliminate the step of raising the temperature of the crucible to a high level in the production process of the glass material. If you refine and homogenize at high temperature,
It is difficult to avoid coloring the glass material.

Here, the defoaming and stirring steps in the manufacturing process of the glass material will be examined. As described above, regarding the number of bubbles, the first
In the glass lump described above, only the batch material is vitrified due to the nature of the production process, so that large bubbles and small bubbles coexist innumerably. If this is made into a fiber, for example, large bubbles become linear during spinning and disappear, but small bubbles are mixed in a spherical shape in the fiber, which impedes the transmission of ultraviolet light and attenuates light. ,
This causes a decrease in internal transmittance. Therefore, in order to ensure the quality of the glass material, the melting step of the second stage is indispensable in the manufacturing process of the glass material, and the melting temperature of the second stage is higher than that of the first stage. Then, it is necessary to perform fining and homogenization with a defoaming agent in the batch raw material over a long period of time to prevent bubbles, foreign substances and striae, and to improve the internal transmittance of the glass material.

In the conventional method for producing glass,
The first glass block obtained at the first stage melting (the glass block obtained at point c in FIG. 2) and the second glass block obtained at the second stage melting (at the point j in FIG. 2). When the external transmittance was measured for the obtained glass lump, the following results were obtained. In this case, the relationship between the first glass lump and the second glass lump will be described with reference to FIG. 3, as shown by a curve a in the first glass lump and a curve b in the second glass lump. Become. That is, the external transmittance of the second glass lump has an ultraviolet wavelength of 310 to 410.
In other words, the second glass block obtained after fining and homogenization has a lower external transmittance and is colored than the first glass block obtained by simply vitrifying the batch material. Was.

Comparing the first stage melting and the second stage melting, the first stage melting uses a silica crucible, so that when the batch material is vitrified, the crucible material is used. Although no foreign matter is mixed into the glass material due to this,
In the melting in the second stage, bubbles, foreign substances, and striae are not generated due to the influence of platinum on the glass material described above due to the platinum crucible used for melting, but the glass material is colored. Therefore, the external transmittance is considered to be deteriorated.

Therefore, in order to solve the drawbacks of the conventional method for producing a glass material and not to deteriorate the light transmission characteristics, for example, a crucible such as a silica crucible which does not use platinum as a crucible material is used. After using a high-purity batch material with a limited amount to prevent impurities from entering the atmosphere in the glass material manufacturing process, the glass is melted after the first stage of melting (vitrification of the batch material). It is preferable to continuously perform the second stage of melting (refining / homogenizing treatment) without molding to produce a glass material.

As described above, in the glass material of the present invention, a sub-base glass component used as a network former was examined from the following viewpoints. First, an SiO ₂ glass material is used to ensure glass formation and ultraviolet transmittance, and has a low LT (liquidus temperature) (softening temperature of the glass material in a platinum crucible, for example, about 1200 ° C. or less) or LT In addition, the glass transition point temperature is high (the glass transition point temperature is higher than the temperature at the time of firing the photocatalyst). A sub-base glass component having a glass composition that can be vitrified at a temperature that can withstand (for example, about 1300 to 1450 ° C.) and can further prevent the coloring by lowering the vitrification temperature was studied.

As the sub-base glass component, from the viewpoint that the vitrification region is easily secured and the glass transition temperature is set to a certain level, the alkali component is experimentally reduced to 10% by weight or less. The glass component was selected and the composition of the glass material was examined. In this study,
As described above in the regulation of the method for producing a glass material of the present invention, although it depends on the glass composition, 1400 to 1500 ° C.
Is the upper limit of the melting temperature of the glass, so that it is a component capable of promoting the defoaming of the glass and maintaining the devitrification resistance at a temperature below this temperature, and 365 ± 30 n in the ultraviolet wavelength range.
The high transmittance since it is a component that can be achieved with m, Al ₂
O ₃ and B ₂ O ₃ were used as sub-base glass components in the glass material of the present invention.

The base glass component is SiO ₂ , but in producing a glass material, B ₂ O ₃ is used for ensuring glass formation, glass melting property and devitrification resistance, and Al ₂ O ₃ is used for producing glass material. , Glass formation, chemical durability, devitrification resistance, and glass transition temperature. Further, the glass material of the present invention further contains an alkaline earth metal for lowering the viscosity of the glass and an additive for adjusting various properties of the glass material under melting conditions and the like.

Next, (SiO ₂ )-(Al ₂ O ₃ )-(B ₂
The alkaline earth metal contained in the O ₃ ) -based glass material for decreasing the viscosity was studied. Here, (SiO
_{2) - (Al 2 O 3} ) - In (B ₂ O ₃₎ based glass materials, in order not to degrade the photocatalytic activity, that it is alkali-free or low-alkali, Na ₂ O-K ₂ O is 0
Alternatively, in a glass system having a small amount, the vitrification region of alkaline earth metal was experimentally examined. However, in this case, a high atomic weight component such as Pb and a high valence component such as La, W, Ta, and Nb whose wavelength absorption edge is on the long wavelength side are excluded, and a transition of Ti, Zr and the like, which are ultraviolet absorbing components, is excluded. The examination was conducted except for metals, Zn, As, Sb, Sn and the like. Then, based on the above-mentioned method for producing a glass material, the raw materials were prepared, melted at a high temperature, and quenched to determine whether or not a transparent glass was obtained. The composition in the vitrification limit region is where the melting temperature and the liquidus temperature (LT) are the same. Further, in the method for producing a glass material, the melting temperature required in the vitrification step and the fining / homogenization step can be made as low as possible without devitrification. It is necessary to select an alkaline earth metal to be added as a raw material for the metal. As for LT, as described above, in the manufacturing process of the glass material and the glass fiber of the present invention, a glass composition that does not devitrify (about 1200 ° C. or less) may be selected in consideration of the applied temperature. It is vital.

In the following, the base glass component Si
In addition to O ₂ , B ₂ O ₃ and Al ₂ O ₃ , in various combinations,
Alkaline earth metal oxides MgO, CaO, BaO
Will be described with respect to the range of the vitrification region, the melting temperature, and the LT when glass is contained as an alkaline earth metal subbase component in a glass material.

FIG. 1 shows that (SiO ₂ + B ₂ O ₃ ) —MgO—
Al ₂ O ₃ system, (SiO ₂ + B ₂ O ₃ )-(MgO + Ca
O) -Al ₂ O _{3 system, (SiO 2 + B 2 O} 3) -CaO-A
l ₂ O ₃ system, (SiO ₂ + B ₂ O ₃₎ glass region in -BaO-Al ₂ O ₃ based glass, shows a schematic view of the range of the melting temperature, LT, these and (SiO ₂ + B ₂ O ₃ )
_{- (CaO + BaO) -Al 2} O 3 based on the characteristics of the glass will be described.

As the glass material of the present invention, a glass material having a narrow range of devitrification temperature and a high minimum temperature of devitrification temperature is selected. This is to select the optimum alkaline earth metal for the glass material of the present invention. For example, the direction of the absence of crystals can be predicted by the crystal shape, the crystallization speed can be assumed by the amount of crystals, and the position of the crystals can be assumed to prevent the precipitation of crystals from the stability of the crystals. be able to. The method for selecting the composition of the glass material of the present invention will be described below with reference to FIG.

First, as shown in FIG.
₂ + B ₂ O ₃ ) -MgO-Al ₂ O ₃ -based glass has a narrow vitrification region, and has no LT region of 1200 ° C. or less.
T is high, which is not preferable. As shown in FIG.
(SiO ₂ + B ₂ O ₃ )-(MgO + CaO) -Al ₂ O ₃
Although the vitrification region of the system glass is not narrow, the vitrification region is not in a preferable range, and there are regions where the melting temperature is relatively low, but there are few regions where the LT is 1200 ° C. or lower.
Further, even in the region where the LT is 1200 ° C. or less, the viscosity of the glass is too low, which is not preferable in characteristics.

As shown in FIG. 1C, (SiO ₂ + B _{2
O 3) -CaO-Al 2 O} 3 based glass has a wide vitrification region, there is a relatively low region melting temperature, because of the low LT region in the low melt temperature range, the glass melting conditions Since the devitrification resistance can be maintained even when melting at a low temperature, it is preferable to apply the glass material of the present invention.
As shown in FIG. 1D, (SiO ₂ + B ₂ O ₃ ) -Ba
O-Al ₂ O ₃ based glass has a wide vitrification area, with there is a relatively low area A of the melting temperature, low LT (1
There is a region B (200 ° C. or less), and B is a high-viscosity region.
However, this is not applicable because A and B do not overlap.

Although not particularly shown, (SiO ₂ + B ₂ O ₃ )
_{- (CaO + BaO) -Al 2} O 3 based glass, previously described _{(SiO 2 + B 2 O 3} ) and -CaO-Al ₂ O ₃ based glass is almost similar properties were obtained, viscosity than this This is not preferable under the glass melting condition because of the increase.

Therefore, the glass material of the present invention, S
adding _{iO 2 -B 2 O 3 -Al 2} O 3 in the glass to a network former, alkaline earth is a network model Day Fire metal oxide (alkaline-earth metal sub-base component) to CaO, melt stability For improvement, oxides of other alkaline earth metals include MgO, SrO, B
A small amount of aO was allowed to be added. That is, SiO ₂
By adding CaO to the —B ₂ O ₃ —Al ₂ O ₃ -based glass, it is possible to enhance the glass formation, the glass melting property, and the devitrification resistance. That is, the glass material of the present invention has SiO ₂ as a base component, Al ₂ O ₃ and B ₂ O _3.
Is a sub-base component and CaO is an alkaline earth metal sub-base component for viscosity control. The detailed components and their properties will be described later.

Next, as will be described later, since the absorption region of the Fe ³⁺ wavelength is near 365 nm, the iron content of the impurity causes a decrease in ultraviolet transmittance and coloring, so that the iron content is as small as possible. Need to reduce.

For the reasons explained above, the glass material of the present invention is expressed by 35% to 60% of SiO ₂ and Al ₂ O _{3 in} terms of% by weight.
_{4~30%, B 2 O 3 4~25} %, CaO 4~40
% And an alkali metal oxide of 0 to 10% and an iron content of 50 ppm or less as Fe. Preferably, in terms of weight%, SiO ₂ 49-5
_{6%, Al 2 O 3 12~17} %, B 2 O 3 6~14%,
One containing 16 to 25% of CaO can be mentioned.

Preferably, SiO 2 is expressed in terms of% by weight.
_2, the total content of _{Al 2 O 3, B 2 O} 3 can be mentioned those which are 59-90%. In addition, preferably, the total content of SiO ₂ , Al ₂ O ₃ , B ₂ O ₃ , and CaO in terms of% by weight is 85 to 100%. Furthermore, the iron content is preferably 10 ppm or less, more preferably 1 ppm or less as Fe.

In the glass material of the present invention, if desired, MgO, BaO and Sr
O may be contained at least one selected from the group consisting of MgO 0
-8%, BaO 0-10% and SrO 0-10%
And their total content is preferably 15% or less.

Further, if desired, K ₂ O is expressed in terms of% by weight.
May also contain 0-10%, as still another _{component, PbO, ZrO 2, TiO 2} , La 2 O 3, P 2 O 5,
At least one selected from WO ₃ , Bi ₂ O ₃ , Ta ₂ O ₅ , Nb ₂ O ₅ , Gd ₂ O ₃ and F may be contained. As other components, As ₂ O ₃ , At least one selected from SnO ₂ and Sb ₂ O ₃ may be contained.

The characteristics of the glass material of the present invention and the components forming the glass fiber and the content of each component are described as follows: SiO ₂ , Al ₂ O ₃ , and B ₂ O ₃ are network formers; Si as fire
_{O 2 -Al 2 O 3 -B 2} O 3 -CaO based silicate glass, borosilicate glass, for aluminosilicate glass (glass and the components essential components), respectively will be described in detail.

Since SiO ₂ is a glass forming component, it is an essential component for the present invention. SiO ₂ is 35
When the amount is less than 60% by weight, the devitrification resistance and the chemical durability deteriorate. When the amount exceeds 60% by weight, the viscosity of the glass increases.
Melting becomes difficult. Furthermore, the chemical durability is good and the rise of the transmittance of the glass material is shifted to a short wavelength,
In order to ensure high transmittance near 365 nm in the ultraviolet region, the content of SiO ₂ is preferably set to 49% by weight or more. In order to increase the glass transition temperature, the content of SiO ₂ is set to 56% It is preferred that the content be not more than% by weight. Also,
When the content of the SiO ₂ component is increased, the expansion coefficient of the glass is reduced, and when the content is reduced, the glass can be melted at a low temperature.

Al ₂ O ₃ is a component that has the effect of improving the chemical durability and heat resistance of glass and lowering the liquidus temperature. However, in a glass material containing SiO ₂ at the above-described content and containing SiO ₂ as a base glass component, considering the balance with the essential components SiO ₂ , B ₂ O ₃ and CaO, Al _When the content of ₂ O ₃ is less than 4% by weight, the chemical durability deteriorates and the glass transition temperature decreases. When the content exceeds 30% by weight, the devitrification resistance deteriorates and the glass production becomes difficult. Therefore, the content of Al ₂ O ₃ is 4 to 30% by weight, preferably 12 to 17% by weight. If the content of the Al ₂ O ₃ component is too large, the melt viscosity increases. If the content is too low, the melt viscosity decreases. Therefore, the base glass component (SiO ₂ ) and other sub-base glass components (B ₂ O ₃ ) It is preferable to adjust the content thereof in balance with the alkaline earth metal subbase component (CaO).

B ₂ O ₃ is a component that has the effect of lowering the viscosity of the glass and improving the melting property, and thus lowers the melting temperature and further improves the weathering resistance. B ₂ O ₃ is
It is a component for lowering the melting point, and the higher the content, the lower the viscosity, the lower the melting temperature, and the lower the chemical durability, but the higher the devitrification resistance. SiO ₂ , Al ₂ O ₃ ,
In the glass material of the present invention containing B ₂ O ₃ and CaO as essential components, the content of B ₂ O ₃ is less than 4% by weight in consideration of the balance with the components of SiO ₂ , Al ₂ O ₃ and CaO. In this case, the meltability is poor, the balance with the other components is poor, and as is clear from FIG. Further, in such a glass material, when the content of B ₂ O ₃ exceeds 25% by weight, the tendency of phase separation increases, and it becomes difficult to obtain a homogeneous glass. Therefore, from this perspective,
The content of B ₂ O ₃ is 4 to 25 wt%, preferably 6-14 wt%. More specifically, when the content of B ₂ O ₃ is large, the vitrification region can be enlarged.
The advantage is that the rise of the transmittance shifts by a short wavelength, and if the amount is small, the glass transition point temperature is increased and the chemical durability is improved. There is a disadvantage that it decreases. Therefore, in the glass material of the present invention, the balance of B ₂ O _{3 with} the base glass component (SiO ₂ ), other sub-base glass components (Al ₂ O ₃ ), and the alkaline earth metal sub-base component (CaO) is considered. Adjust the content. If B ₂ O ₃ is used in a small amount, its properties, for example, the property of lowering the viscosity of glass,
Since the characteristics are the same as those of O, if the above characteristics can be improved, the predetermined content of B ₂ O ₃ can be replaced by CaO. When the amount is relatively large, the content of B ₂ O ₃ can be reduced.

In the glass material of the present invention containing SiO ₂ , Al ₂ O ₃ , B ₂ O ₃ and CaO as essential components, SiO ₂ , A
When the total content of l ₂ O ₃ and B ₂ O ₃ , that is, the content of the network former is less than 59% by weight, the components other than the network former forming the glass material become 41%.
However, if it is composed of an alkaline earth metal and a small amount of alkali metal, the glass transition point temperature may be lowered. Due to a decrease in elasticity,
There is a possibility that a situation in which glass cannot be formed may occur. On the other hand, if the content of the components other than the network former exceeds 90% by weight, the viscosity increases. At this time, the remaining component forming the glass material is less than 10% by weight, but if this is composed of an alkaline earth metal and a small amount of alkali metal, the viscosity may increase and the meltability may deteriorate. Further, in this case, even if an alkaline earth metal is composed of a low molecular weight component, the viscosity is reduced and the devitrification is deteriorated, so that it is difficult to form a glass by any method. Therefore, SiO ₂ , Al ₂
The total content of O ₃ and B ₂ O ₃ is 59 to 90% by weight.

CaO is a component exhibiting an action substantially similar to that of MgO described later, and is a component that lowers the viscosity of glass. However, when CaO is adjusted alone, when it exceeds 20% by weight, the devitrification resistance is reduced. Although reduced, the SiO _{2 of} the present invention
In a glass material having a base glass component, Al ₂ O ₃ ,
It is possible to further improve the devitrification resistance by balancing the respective contents of SiO ₂ . In other words, CaO is a component that improves the melting property of glass because it lowers the melting temperature of glass by generating carbon dioxide gas, thereby lowering the viscosity and coefficient of thermal expansion of glass. Is a component that makes it possible to increase the viscosity of glass, perform good spinning, and improve the bending strength of the fiber. That is, in melting the glass, it is possible to reduce the dissolution of SiO _{2 in} the crucible into the glass, to reduce the volatilization of other glass components, and to reduce the intrusion of foreign substances due to erosion of the crucible. it can.

As shown in FIG. 1, SiO ₂ , Al ₂ O ₃ ,
In a glass material containing B ₂ O ₃ and CaO as essential components,
From these balances, it is necessary that the content of CaO be 4% by weight or more in order not to increase the melt viscosity excessively, and to secure devitrification resistance, an additional 40% by weight is required. % Or less. Therefore, the content of CaO is 4 to 40% by weight, preferably 4 to 40% by weight.
It is 30% by weight, more preferably 16 to 25% by weight.

In a glass material containing SiO ₂ , Al ₂ O ₃ , B ₂ O ₃ , and CaO as essential components, the total content thereof, that is, the total content of the network former and the network modifier is determined by the resistance to loss. In order to ensure permeability, the content is preferably 85 to 100% by weight. However, when the content of B ₂ O ₃ is large in the glass material, the content is not limited to this, and it is possible to appropriately adjust the content to less than 85% by weight.

MgO, SrO and BaO are components that can adjust the properties, melting property and devitrification resistance of glass by adding an appropriate amount. MgO is a component that lowers the thermal expansion coefficient and viscosity of the obtained glass, and improves the melting property and devitrification resistance of the glass. However, SiO ₂ , Al ₂ O ₃ , B ₂ O ₃ ,
In the glass material of the present invention containing CaO as an essential component,
When the content of MgO exceeds 8% by weight, the devitrification resistance deteriorates. Therefore, the content of MgO is preferably 0 to 8% by weight,
More preferably, it is 0 to 5% by weight.

SrO is a component for improving the devitrification resistance of the glass. However, the glass material of the present invention containing SiO ₂ , Al ₂ O ₃ , B ₂ O ₃ and CaO as essential components contains SrO. When the amount exceeds 10% by weight, the devitrification resistance deteriorates. When a region having good devitrification resistance is selected, the SrO content becomes higher when the content exceeds 10% by weight. , 0 to 10% by weight, more preferably 0 to 5% by weight.

BaO is a component exhibiting an action almost similar to that of SrO, but is composed of SiO ₂ , Al ₂ O ₃ , B ₂ O ₃ and CaO
In the glass material of the present invention containing, as an essential component, BaO
When the content exceeds 10% by weight, the devitrification resistance deteriorates. When a region having good devitrification resistance is selected, when the content of BaO exceeds 10% by weight, the viscosity becomes high.
Is preferably 0 to 10% by weight.

In the glass material of the present invention containing SiO ₂ , Al ₂ O ₃ , B ₂ O ₃ and CaO as essential components, MgO, Sr
The total content of O and BaO is SiO ₂ , Al ₂ O ₃ , B ₂
When the content of O ₃ and CaO is in the above range,
If the content exceeds 15% by weight, the devitrification resistance deteriorates.
5% by weight is preferred.

Further, ZnO is a component for improving the stability of glass, and is 0 to 20% by weight, preferably 0 to 10% by weight.
% By weight. In this case, Ca
If the total content of O, MgO, SrO, BaO, and ZnO exceeds 60% by weight, the devitrification resistance tends to deteriorate. Therefore, CaO, MgO, SrO, BaO and Zn
The total content of O is preferably from 20 to 60% by weight, particularly 2% by weight.
A range of 0 to 30% by weight is preferred.

The alkali components of Li ₂ O, Na ₂ O, K ₂ O, and Cs ₂ O are components that lower the viscosity of the glass and improve the melting property, and the total content of these alkali components is 1%.
If it exceeds 0% by weight, when used as a photocatalyst carrier,
Photocatalytic activity is undesirably deteriorated. Therefore, their total content is from 0 to 10% by weight. For similar reasons, their total content is preferably from 0 to 5% by weight,
More preferably, it is 0 to 2% by weight. When one kind of these alkali components is selected and used as one component of a glass material, the content of K ₂ O is preferably 0 to 10% by weight, more preferably 0 to 3% by weight, and furthermore Preferably it is 0 to 1% by weight. In other words, K can stabilize the glass with a small amount, so that the devitrification can be reduced and the melting temperature can be lowered. since hard, in the case of applying the glass material as a photocatalyst filter, a photocatalyst in contact with glass, for example, a TiO ₂ side K
It is the most advantageous component as an alkali component because ions are hard to move.

Further, in addition to the above-mentioned components, the glass material may contain PbO, Zr or Zr in a range that does not impair desired properties.
O ₂ , TiO ₂ , La ₂ O ₃ , P ₂ O ₅ , WO ₃ , Bi ₂ O ₃ ,
Components such as Ta ₂ O ₅ , Nb ₂ O ₅ , Gd ₂ O ₃ and F are
To improve devitrification resistance, melting property, chemical durability, etc.
Alternatively, it can be added as a defoaming agent or the like, and is further provided with a measure against solarization. However, in the glass material and glass fiber of the present invention, for example,
_It has the characteristic that bubbles can be removed in the production of glass material without adding a defoaming agent such as ₂ O ₃ , Sb ₂ O ₃ , SnO ₂ as a composition of the glass material. In addition, these defoamers are environmentally harmful substances and need not be added, but may be added if necessary.

The glass material of the present invention as described above is preferably manufactured through the following steps (A), (B) and (C). It is preferably manufactured through the following spinning process. The manufacturing method of the glass material and the glass fiber of the present invention will be described with reference to FIG. FIG. 4 is a graph showing in chronological order one example of the relationship between time and temperature in the manufacturing process of the glass material and the glass fiber of the present invention.

Step (A): As described above, in these steps (A), (B) and (C),
In view of the above, measures have been taken against contamination of impurities in the batch material and the like and contamination of the batch material. In the step (A), first, high-purity hydroxides, carbonates, nitrates, sulfides, oxides, nitrides, and the like, which are limited in the content of impurities, are blended in a predetermined ratio to prepare a batch material. After the preparation, this batch material is heated and melted in a crucible to obtain a glass state. Here, as a high-purity raw material, the amount of impurities in each raw material is 50 ppm or less, for example, when the amount of iron in the raw material mixture is 50 ppm, for the reasons described above.
ppm or less. In the preparation of the raw material mixture, avoid contact with metals during blending and melting, and keep the raw materials and batch raw materials free from dust and dirt during storage and storage. Make sure there is no contamination. In the melting of glass, as described above, since the raw materials are combined, the gases to be decomposed and released are various. When the glass is vitrified in the step (A), the gas becomes 1 atm and the liquid glass is melted. The liquid is floated and rises to the liquid level so that bubbles are not left as much as possible in the molten glass in the step (A).

In this case, the crucible is made of a material not containing platinum, for example, a material selected from quartz, clay, glassy carbon, alumina, and refractory bricks. Are preferred. The silica crucible is made of high-purity SiO ₂ , for example, when impurities such as iron, which cause coloring of the glass material, are mixed in the batch material, and the impurities are thermally oxidized by heating the crucible. Even if it is, silica itself is not a substance exhibiting reactivity, and therefore does not act as a catalyst for impurities. For example, the crucible itself does not act as a factor to oxidize iron or the like which is easily mixed as impurities. Further, even if the crucible material is melted into the glass material in the crucible, if the silica crucible is used, since SiO ₂ is present in the batch raw material, the material of the crucible, SiO _2, is added to the glass being melted. It is excellent in that it does not cause a problem in the glass composition, shows reactivity to other substances, and does not participate in the oxidation reaction of metals.

The above-mentioned clay crucible contains A as a main component.
It contains l ₂ O ₃ and SiO ₂ at a ratio of about 90% by weight, and the inner surface of the crucible is made of SiO ₂ .
The glassy carbon crucible has carbon as the main component and occupies about 99% by weight, and the alumina crucible contains Al ₂ O ₃ as the main component in a proportion of about 90% by weight or more,
In addition, it contains SiO ₂ . Further, the refractory brick crucible contains Al ₂ O ₃ as a main component at a ratio of about 94% by weight or more.

Thus, in the crucible as described above, if Al ₂ O ₃ and SiO ₂ are one component of the glass material,
Since the main component is a component constituting the glass material or a substance that evaporates, there is no problem even if these dissolve or evaporate in the glass material, and a desired glass material can be manufactured.

In the preparation of the raw material mixture,
In the step (A) and the step (B) described later, a glass material having a desired composition is obtained in consideration of the type and amount of components eluted from the material forming the crucible into the glass material. It is advantageous to prepare.

In the step (A), the batch raw material is placed in the crucible and stirred with a stirring rod for 600 to 150 minutes.
The mixture is heated to about 0 ° C. and melted (point A in FIG. 4) to obtain a glassy state (point B in FIG. 4). The heating temperature may be appropriately selected according to the composition of the glass. For the borosilicate glass and silicate glass of the present invention, the heating temperature is preferably from 1,000 to 1,500 ° C, and particularly preferably from 1,300 to 1,400 ° C. The heating and melting time depends on the glass composition and the heating temperature, but is generally about 0.5 to 5 hours. For the same reason as the crucible material, the stir bar is made of a material not containing platinum, and the same material as the material constituting the crucible described above can be used. In particular, a material made of quartz is preferable.

Further, in the method for producing a glass material according to the present invention, in order to reduce Fe ³⁺ originating from a substance such as Fe ₂ O ₃ which is a trace impurity contained in the batch raw material to Fe ^2+. In the step (A), which is a vitrification step of the batch raw material, and the step (B), which is a fining / homogenization step, a reducing atmosphere is created. In this case, Fe
^While the absorption region of the ³⁺ wavelength is near 365 nm,
Since the absorption region of the wavelength of Fe ²⁺ is 850 nm, absorption of the wavelength in the ultraviolet region can be prevented. As described above, the content of iron as an impurity in the batch raw material is 0 to 50 ppm, preferably 0 to 10 ppm, so that Fe ³⁺ as an impurity that causes coloring can be reduced to Fe ²⁺ .
More preferably, it is set to 0 to 1 ppm. Fe ³⁺
As a method for reducing N ₂ , A ₂
a reducing atmosphere, for example, a hydrogen-containing atmosphere (H ₂ 8%, O ₂ 12%, N ₂
(80%) in an atmosphere of a float method, for example, reduction by introducing a reducing agent such as an organic substance, or using a metal raw material, for example, Si, Al or the like. Further, the present invention is not limited to this.
The glass material can also be produced using the batch raw material that has been refined to be close to the above.

As described above, there are various methods for reducing atmosphere, but it is most preferable to use a reducing agent. As a reducing agent, a high temperature (1450-1500 ° C.)
) For a long time, for example, about 8 hours, and capable of stably exhibiting a reducing action. For the reasons described above, reducing agents other than iron and iron Is required to be a reducing agent containing no. As the reducing agent, it is preferable to exclude a metal exhibiting a color. However, if a glass fiber manufactured from a glass material has a diameter of 125 μm, a length of 10 cm, and an ultraviolet transmittance of 80%, it is defined as a good product. A metal reducing agent having no absorption in the ultraviolet region and having a high melting point, for example, A
1, Sn, Zn, Ga, Si, Ge and the like. Among these, Si and Ge are preferably used under the condition that a high-purity reducing agent is easily available. However, from the viewpoint that the reducing agent dissolves in the glass material, it is preferable that the component is a glass-forming component. Therefore, in the case of a SiO ₂ glass material such as the glass material of the present invention, it is optimal to use Si as a reducing agent.

Although the amount of the reducing agent depends on the melting time and the melting temperature of the glass, the amount of the reducing agent is from 0.001 to 10
% Is preferable, and it is possible to select within this range according to the melting time and the melting temperature. In other words, the reducing agent does not melt completely within the melting time, the reducing agent does not remain undissolved in the glass material, and in a range where the bubbles can be removed,
A moderate amount of reducing agent can be used. The impurities in the reducing agent are activated by the heat of the metal reducing agent itself by heat, and the metal reducing agent contains impurities as long as the impurities in the batch raw material and the impurities contained therein can be reduced. There is no problem even if you go out. However, from the viewpoint of the efficiency of the reducing action, it is preferable to use one in which iron as an impurity is not contained in the reducing agent, and the content of iron as an allowable impurity in the reducing agent is usually the total amount. 0 to 200 ppm, preferably 0 to 20 ppm
ppm, more preferably 0 to 1 ppm. Also, the input of the reducing agent is mixed into the batch raw material, or
When vitrification is performed, it can be carried out by a method of charging into a batch material.

FIG. 4 shows an example of the step (A). The raw material mixture is heated to about 1300 ° C. (point A in FIG. 4) and held at this temperature for about 1.5 to 3 hours to melt. And vitrified (point B in FIG. 4). In the glassy melt thus obtained, countless large and small bubbles are present. Here, in the glass material as in the present invention,
The raw material mixture is activated by heat, but if the vitrification temperature is in the above range, coloring of the glass can be limited.

Step (B): In this step (B),
The glassy melt obtained in the step (A) is refined and homogenized in a crucible made of a platinum-free material without solidifying, and then molded. The above clarification,
The homogenization treatment is performed by melting the molten material in a glass state from 700 to 1500.
It is performed by heating to about ° C, defoaming, and homogenizing by stirring to prevent striae. This heating temperature is
It is preferable to appropriately select the composition according to the composition of the glass.
0 to 1500 ° C. is preferred, and especially 1400 to 1450 ° C.
Is suitable. The fining and homogenizing time depends on the type of glass and the heating temperature, but is generally about 0.5 to 5 hours. That is, the heat resistance of the silica crucible is limited to about 1450 to 1500 ° C.,
In the vitrification of the step (A) and the fining and homogenization step of the step (B), the crucible cannot be heated to a higher temperature. There is no problem because the components forming the glass material are adjusted to have a viscosity that can eliminate bubbles. Further, the glass material of the present invention is characterized in that fining and homogenization can be preferably performed within the above-mentioned temperature and time ranges without adding a defoaming agent.

FIG. 4 is a graph showing in chronological order one example of the relationship between time and temperature in the step (B) and the glass fiber production step in the production of the glass material and the glass fiber of the present invention. One example of the step (B) will be described with reference to FIG. 4. The glassy melt obtained in the step (A) is continuously heated to about 1450 ° C. (point C in FIG. 4), and the glass is melted. After defoaming and stirring in this state for about 2 to 3 hours, fining and homogenization are performed, and then the mixture is poured into a mold and molded (point D in FIG. 4).

In the step (B), for example, 13
At 00 to 1,400 ° C., the Fe ³⁺ generated by iron as an impurity mixed in the batch material became glass state is oxidized, it continues to subsequently reduced to (A) step, Fe ^{2 +} , And as described above, for example, (B)
The batch raw material in the glass state in the process is 1400-1450 ° C
The fining and the homogenization of the glass are performed while reducing the Fe ³⁺ by heating. That is,
In the step (B), if the viscosity of the molten glass is reduced while exerting a reducing action on Fe ³⁺ , bubbles having a large diameter rise to the liquid surface, and the gas escapes into the air. The large bubbles existing in the molten glass can be removed, and the Fe ³⁺ in the molten glass can be reduced to Fe ²⁺ . That is, in order to perform the fining and homogenizing treatment of the glass and the reduction of iron in the step (B), the viscosity of the molten glass is preferably not more than 10 ³ poise. In addition, since a crucible made of a material containing no platinum is used (the stirring bar is also made of a material containing no platinum), the molten glass is kept at a high temperature such as 1400 to 1450 ° C. for a long time to be refined. Even if the time is sufficient, the glass material is not colored.

The crucible and the stirring rod made of the material not containing platinum are made of a material selected from quartz, clay, glassy carbon, alumina and refractory brick for the same reason as described in the step (A). Are preferable, and those made of quartz are particularly preferable.

In this production method, after vitrification of the batch raw material having high reactivity in the above-mentioned melting,
By immediately raising the temperature and performing defoaming and homogenization in a state in which gas is generated, it is possible to produce a bubble-free glass.

That is, in the above-mentioned method for producing a glass material, since solidification → liquefaction is not performed between the vitrification step and the fining / homogenization step, the production of the glass material can be performed in a short time.
Eventually, a glass fiber described later can be manufactured. In addition, since vitrification, fining, and homogenization are performed continuously, it is possible to shorten the glass material manufacturing process while effectively utilizing heat energy, and minimize the contamination of foreign materials. Become. In the present invention,
Since there is no need to change the crucible between the vitrification process and the fining / homogenization process, other than the components contained in the glass material, such as jigs and molds required for moving the crucible for batch raw materials, etc. Since there is no chance of contact with the glass material and the melting atmosphere does not change, it is possible to prevent foreign matter from entering during the manufacturing process of the glass material. Further, since iron as an impurity mixed in the batch raw material is reduced, it is possible to eliminate the reduction of the ultraviolet transmittance near 365 nm which is the ultraviolet region wavelength, and to eliminate the coloring of the glass material.

As described above, according to the method for producing a glass material of the present invention, the coloring of the glass material can be prevented, the glass having a severe restriction on the degree of coloring, and various glass molded products using such glass It can be easily applied to glass for steppers, glass fibers that must transmit ultraviolet rays, photocatalytic fibers, and the like.

In the step (B), fining and homogenization are preferably performed at a temperature of 1400 to 1450 ° C., and then, if necessary, the glass is placed in a platinum crucible at 600 ° C.
By heating to about 1300 ° C. and holding at this temperature, the molten glass can be further refined and homogenized, and the molten glass can be poured into a mold and molded. The time required for the glass fiber manufacturing process, which will be described later, is prolonged accordingly, and the glass material and glass fiber are manufactured in a long time.

Step (C): In the step (C), in the step (B), the molten glass that has been subjected to the fining and homogenization treatment is poured into a mold and the molded glass is gradually cooled. The minute bubbles inside are redissolved into the glass to obtain a glass block having a desired shape. The point E will be described with reference to FIG. There is no particular limitation on the shape of the glass lump,
For example, when a glass fiber is manufactured using this glass lump, a glass fiber having a diameter of about 60 mm, a length of about 280 mm, a columnar block, or the like is manufactured in accordance with the shape of a crucible in a spinning furnace. You.

The steps (A), (B),
In the step (C), a description will be given of a change in the transmittance characteristic due to a change in the manufacturing conditions of the glass material which is a coloring factor due to iron impurities as described above.

FIG. 5 shows the spectral transmittance characteristics of a glass material prepared by changing the parameters according to the present invention from the conventional glass material manufacturing method in order under the same glass material composition and the respective glass material manufacturing conditions. FIG. The glass material showing these transmittance curves is a glass material polished to a thickness of 10 ± 0.1 mm, and 700 n from the rising wavelength.
This is a measurement of spectral transmittance (including reflection loss) in a wavelength range up to m.

The transmittance curve a shows the transmittance curve of the glass material manufactured by the conventional method for manufacturing a glass material shown in FIG. According to the transmittance curve a, although the rising of the wavelength is shifted to the shorter wavelength side, the melting method is such that bubbles, foreign substances, and striae do not appear, and thus the transmittance does not decrease for such a reason. However, it is colored due to iron which is an impurity in the glass material, and the transmittance at 310 to 410 nm, that is, the transmittance in the ultraviolet region is reduced.

As described above, the transmittance curves b and c indicate that the amount of impurities in each high-purity batch material is 50 pp.
m, using a high-purity batch raw material containing a small amount of iron impurities and purified so as to prevent the impurities from entering the atmosphere in the glass material manufacturing process, by the step (A) of the present invention, The transmittance curve of the glass material produced by the glass material production process using the silica crucible in the process (B) is shown. According to the transmittance curve b, the rise of the wavelength is shifted to the shorter wavelength side as compared with the transmittance curve a, and according to the transmittance curve c, the wavelength caused by impurities in the batch raw material around 365 nm Absorption is seen,
The transmittance has decreased. As described above, the factor of the decrease in transmittance is Fe ³⁺ in which iron as an impurity in the batch raw material is oxidized. When the glass material is manufactured by the above-described manufacturing method, the transmittance such as the transmittance curve b or the transmittance curve c may vary depending on the amount of impurities and the time required for the steps (A) and (B). It becomes a rate curve.

Further, the transmittance curve d shows the F value caused by the impurity iron in the batch material in the manufacturing process of the glass material of the present invention.
9 shows a transmittance curve when e ³⁺ is reduced. In this case, as compared with the transmittance curves b and c, the transmittance curve is further shifted to the shorter wavelength side, and the transmittance is not reduced at 365 nm near the ultraviolet wavelength region at all. Furthermore, coloring of the glass material is minimized.

Next, a method of manufacturing a glass fiber using the above glass lump will be described. In the method for manufacturing a glass fiber according to the present invention, the glass material obtained as described above is spun in a spinning furnace to manufacture a glass fiber. When a glass material is manufactured by softening and spinning a glass material, a certain degree of viscoelasticity is required. In other words, when fiberizing glass by spinning, it is better to produce fibers of various diameters because the variation of applied products is widened. Therefore, the glass fiber of the present invention has viscoelasticity in composition and has manufacturing characteristics. It becomes more advantageous. Also, when the fiber diameter is the same and the fibers are bundled round,
At the minimum value of the radius of the bundled fiber, the smaller the radius, the more the glass itself has viscoelasticity and the stronger it is. Therefore, the glass fiber of the present invention has excellent viscoelasticity and chemical durability.

The spinning furnace is preferably made of platinum, and the spinning process is advantageously performed at a temperature in the range of 600 to 1300 ° C. An example of this spinning process will be described with reference to FIG.
A 0 mm cylindrical block-shaped block of glass is cut out, the glass block is put into a platinum spinning furnace, and the glass block is re-melted at a temperature equal to or higher than the devitrification temperature of the glass material, which is suitable for spinning. The spinning treatment is performed so as to obtain such a viscosity. For example, heating a lump of glass to about 1100 ° C. (FIG. 4)
At point F), the glass is re-melted, and the re-melted glass is subjected to spinning treatment (point G in FIG. 4).

According to such a method, since a glass mass without coloring and bubbles is used, the coloring of the glass in the remelting step in the platinum spinning furnace can be minimized even in the spinning treatment. Foam-free glass fibers can be spun. Here, in the spinning process, the softening and shaping of the glass mass in the platinum crucible are performed, so that the crystal is not contained in the manufactured glass fiber, the liquidus temperature of the glass, that is, At a temperature higher than the devitrification temperature (hereinafter referred to as LT), the glass block must be softened and the fiber must be formed.

That is, when crystals are precipitated in the glass fiber, the glass becomes opaque and impedes light, or when softening is interrupted during the softening of the glass, the glass hardens. However, there is a problem that clogging occurs at the outlet from the platinum crucible and molding cannot be performed. However, since the softening temperature and the forming temperature of the glass due to LT are different depending on the composition of the glass material, when applying such a method of manufacturing a glass fiber, the glass material as in the present invention is used. If the composition,
Since the softening temperature of the glass is low and the forming temperature is sufficiently low, the glass material can be preferably spun to form a fiber.

In addition, when the glass is devitrified, that is, when the glass is LT, the viscosity becomes softer as the temperature becomes higher, and becomes harder as the temperature becomes lower. Since it must be carried out, it must satisfy the conditions of moderate softening viscosity and fiber molding viscosity, and must not be devitrified at the fiber molding temperature at which spinning is performed. In the glass material of the present invention, the glass composition are determined in view of these points, generally the softening viscosity within the range of the glass composition, will vary according to the balance of each component, 10 ⁵ poise or less And the fiber molding viscosity is 10 ² to 10 ⁶ poise, preferably 10 ³ to 10 ³ poise.
It becomes 10 ⁵ poise.

Here, a platinum crucible is used in the spinning step, and a glass material is manufactured using a silica crucible in the steps (A) and (B). The possibility of coloring arises. That is, when performing fiber molding such as a spinning process,
A platinum crucible must be used for reasons such as good workability. Therefore, the temperature may be lower than the heating temperature of the crucible in the steps (A) and (B) for melting, refining, and homogenizing the glass, but the temperature is higher than the LT of the glass. Must. Therefore,
In the production of the glass fiber of the present invention, it is necessary to perform spinning while preventing coloring of the softened glass. On the other hand, the present inventors have conducted intensive studies on the coloring temperature of the platinum crucible, and as a result, it has been found that when the softened glass is held in a platinum crucible at around 1200 ° C., the softened glass gradually becomes colored.

As an example, using a platinum crucible, 1200
C., and the glass material obtained in the steps (A), (B), and (C) is used to start the spinning process of the glass material, that is, the softening and fiber forming, and the glass fiber ( GF1) was compared with a glass fiber (GF2) obtained 6 hours after the start of fiber molding. Glass fiber GF1, GF2 each 10cm
The glass fibers GF1 and GF2 were examined for external transmittance by a generally known method. As a result, the glass fiber GF1 obtained immediately after the start of fiber molding was obtained.
The transmittance of the glass fiber GF2 was reduced by about 40% as compared with the transmittance of the glass fiber GF2. Thus, 1200 ° C
With the lapse of time to hold the softened glass in the platinum crucible held in the glass fiber, it becomes clear that the coloration of the glass fiber produced by fiber molding progresses, albeit at a low speed, and the glass fiber is colored. And the transmittance decreases at a wavelength of about 365 nm. By softening the glass material manufactured through the steps (A), (B) and (C), the iron contained in the glass material is reduced. It is assumed that Fe ³⁺ is generated in the glass which is gradually oxidized and re-melted, and is colored due to this.

However, the platinum crucible has a shape with a hole at the bottom, and the glass material is softened by holding the glass material at a predetermined temperature, and the softened glass is gradually discharged as a fiber from the bottom of the crucible. When the fiber is formed by the method described above, it is inevitable that the glass material is held in the platinum crucible for a predetermined time according to the outflow speed and the outflow amount of the glass. However,
Since the heating temperature of the crucible in the spinning process is lower than the respective heating temperatures in the manufacturing process of the glass material,
Iron is not easily thermally oxidized, but platinum acts as a catalyst for accelerating the oxidation reaction, and the glass is re-melted little by little. However, in the present invention, since a batch material purified to a high purity with an iron content of 50 ppm or less is used, the iron content in the glass material is small, and the glass fining / homogenization process is also performed. Since the heating temperature of the glass is lower than that of the glass fiber, in order to prevent the coloring of the glass fiber, the holding time of the softened glass in the platinum crucible is reduced by limiting the amount of the glass to be softened and spun. It is also possible to realize a glass fiber having a high ultraviolet transmittance.

Further, as described above, depending on the intended use, if the UV transmittance of the glass fiber produced by the spinning process under the above conditions is about 80% and good, the coloring speed on the glass is not large. Since the coloring of the glass fiber cannot be determined visually,
For example, a glass fiber that can be preferably used as a glass fiber for supporting a photocatalyst can be manufactured. The glass material obtained by such a method is widely used in fields other than a glass material for supporting a photocatalyst, a photocatalyst fiber using the glass material, and a filter using the same as a glass material that does not reduce the photocatalytic activity. Application is possible.

When a photocatalyst fiber is produced using the glass fiber thus obtained, the photocatalyst supported on the glass material is not particularly limited. For example, titanium oxide or its compound, iron oxide or its compound ,
Zinc oxide or its compound, ruthenium oxide or its compound, cerium oxide or its compound, cadmium oxide or its compound, strontium oxide or its compound, and the like. These photocatalysts may be used alone, or two or more photocatalysts may be used in combination or in combination (for example, each independently present).

Here, when the photocatalyst is supported on the glass material of the present invention or the glass fiber of the present invention, the expansion coefficient of the glass is almost equal to that of the photocatalyst, so that the photocatalyst can be preferably supported. That is, since the temperature of the glass coated on the photocatalyst is increased and the photocatalyst is adhered to the glass by firing, if the expansion rates of the photocatalyst and the glass material (glass fiber) are equal, the photocatalyst layer is not distorted, Not only does there be no risk of performance degradation, but also there is no risk of film peeling due to mismatch in expansion coefficients. Examples of the photocatalyst include anatase type TiO _2, whose average expansion coefficient is about 45 × 10 ⁻⁷ , and the glass material of the present invention is 50 × 10 ^−7.
Since they are 10 ^{−7 to} 60 × 10 ⁻⁷ , their average expansion coefficients are almost the same. That is, in the glass material of the present invention, since the base glass component is made of SiO ₂ and is a non-alkali or low alkali glass material, the alkalis having the largest expansion factor are reduced and the SiO ₂ having the smallest expansion factor is used. By being a main component, the expansion rates of the photocatalyst and the glass material (glass fiber) are substantially equal.

Examples of a method for supporting a photocatalyst on a glass fiber produced by the method for producing a glass fiber of the present invention include, for example, a sol-gel method, aerosol method, a wash coat method, a vapor deposition method, a sputtering method, a thermal decomposition method, and a metal decomposition method. Oxidation method and the like can be mentioned. The film thickness is usually about 1 nm to 1 mm. The wavelength and intensity of the light applied to the photocatalyst can be appropriately selected according to the type of the photocatalyst. For example, if the photocatalyst is TiO ₂ , it can excite the photocatalyst.
00 nm UV light is preferred. As a light source, a mercury lamp, a mercury-xenon lamp, or the like can be used.

To the photocatalyst, a substance having an action such as enhancement of catalytic activity, adhesion strength, stability, photoreaction or adsorptivity can be added as an additive, or these substances can be used as an undercoat layer of the catalyst layer. Can be used. Such substances include, for example, Cr, Ag, C
u, Au, Pt, Ru, Pd, Rh, Sn, Si, I
Examples include elements such as n, Pb, As, Sb, and P, and oxides or compounds thereof.

A filter device using a photocatalyst filter in which a photocatalyst is supported on the above glass material is a solid particulate (particulate) composed of black smoke, unburned hydrocarbons and lubricating oil contained in the exhaust gas of a diesel engine. Particulate Filter (DP)
F), a gas treatment filter (for example, an air filter for a clean room, an air purifier), and a liquid treatment filter (for example, a filter for water or seawater purification).

Further, in the above glass fiber, a projection can be formed on the surface of the glass fiber. As a result, the surface area is increased as compared with the case where there is no projection, and it is possible to improve the efficiency of the filter having the function of purifying the fluid by utilizing the surface reaction of the catalyst carried on the filter. Here, the catalyst (including the surface reaction promoting substance)
Is not particularly limited, and a substance having a fluid purifying action can be used.

[0109]

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

Examples 1 to 4 As raw materials, high-purity hydroxides, carbonates and the like purified so that the impurities in each raw material were 50 ppm or less, respectively.
Using nitrates, sulfides, oxides, nitrides, etc., the respective raw materials were mixed so that the compositions after melting and slow cooling would be the glass compositions shown in Examples 1 to 4 and Comparative Example 1 in Table 1. After the raw material mixture was prepared, it was put into a quartz crucible, heated to about 1300 ° C., and kept at that temperature for 2 hours to melt and vitrify the raw material mixture. There were countless large and small bubbles in the molten glass.

Subsequently, the mixture is heated to about 1450 ° C., and while the glass is in a molten state, defoaming and stirring (using a stirring bar made of quartz) are performed for 2.5 hours to perform fining and homogenization. Was poured into a mold and molded.

Next, the molten glass poured into the mold was gradually cooled to a diameter of about 60 mm and a length of about 280.
A cylindrical block of glass having a size of mm was produced. In the manufacturing methods of the glass materials of Examples 1 to 4 and Comparative Example 1, the glass materials were manufactured such that foreign substances due to external factors were not mixed during the manufacturing process.

Further, from the cylindrical block-shaped glass blocks obtained in Examples 1 to 4 and Comparative Example 1, cylindrical block-shaped glass blocks having a diameter of about 60 mm and a length of about 90 mm were cut out. Was. The cut glass lump of each example was put into a spinning furnace made of platinum and heated to about 1100 ° C. to remelt the glass lump (viscosity of about 1000 poise). Next, the re-melted glass was spun to obtain a diameter of 1 mm.
A glass fiber having a length of 25 μm and a length of 100 mm was produced.

The block-like glass block obtained in this manner was evaluated for its thermal properties [devitrification temperature (° C.)] and viscosity (1
(Poise at 300 ° C.), the average expansion coefficient, and the fine drawable diameter of the obtained glass fiber were measured. The results are shown in Table 1, and the Fe content in the glass is also shown.

[0115]

[Table 1]

When Examples 1 to 4 and Comparative Example 1 are compared,
Since the viscosity at 1300 [deg.] C. is much lower in Examples 1 to 4, bubbles were easily removed, and it was found that the glass could be preferably melted even when the melting temperature of the glass was low. Moreover, since the thinning possible diameters of Examples 1 to 4 were smaller than that of Comparative Example 1 and were possible, it was found that they were suitable for fiber molding. Furthermore, the average expansion coefficient of Examples 1-4 are close to the average expansion coefficient of the TiO _2, since the TiO ₂ is carried suitably upon firing of TiO _2, a photocatalyst carrying glass material, a photocatalyst carrying glass fibers Has been found to be preferably used.

Example 5 As raw materials, high-purity hydroxides, carbonates, and the like purified so that impurities in each raw material were 50 ppm or less, respectively.
Using nitrates, sulfides, oxides, nitrides, and the like, and mixing the raw materials to prepare a raw material mixture such that the composition after the slow cooling of the melt becomes the glass composition shown in Example 1 of Table 1, Put into a quartz crucible and, together with it, a high purity (impurity content of 0.1p
pm) of Si in an amount of 0.01% by weight with respect to the raw material mixture, and heated to about 1300 ° C.
After holding for a time, the raw material mixture was melted and vitrified.
There were countless large and small bubbles in the molten glass.

Subsequently, the mixture was heated to about 1450 ° C., and while the glass was in a molten state, defoaming and stirring (using a stirring bar made of quartz) were performed for 2.5 hours, followed by clarification and homogenization. Was poured into a mold and molded. Even in this fining and homogenization, the Si reducing agent continued the reduction reaction.

Next, the molten glass poured into the mold was gradually cooled to obtain a diameter of about 60 mm and a length of about 280.
A cylindrical block of glass having a size of mm was produced. In the method for manufacturing a glass material according to the fifth embodiment,
The glass material was manufactured so that foreign substances due to external factors were not mixed during the manufacturing process. Fe content in glass is 1.0
ppm.

Example 6 A cylinder-shaped block of glass was produced in the same manner as in Example 5, except that 0.05% by weight of high-purity Si was used as a reducing agent.

Test Example From the cylindrical block-shaped glass block obtained by the method for producing glass materials of Examples 1 and 5, a diameter of about 60 mm and a length of about 9 mm were obtained.
A cylindrical block of glass having a size of 0 mm was cut out. Further, two 1-cm × 1-cm × 1-cm cullet-shaped glass blocks were cut out from the cylindrical block-shaped glass block, two for the glass block of Example 1 and one from the glass block of Example 5. FIG. 6 shows the results of measuring the external transmittance of each of the above samples as one sample of Example 1, two samples of Example 1, and a sample of Example 5.

As shown in FIG. 6, the transmittance of the samples of Example 1 and Example 1 at 365 nm was about 81.2 to 84.5%. In contrast, the transmittance of the sample of Example 5 at a wavelength of 365 nm was 9
At 0.9%, it showed a higher UV transmittance than the two samples 1 and 1 of Example 1 above.

Next, in the same manner as described above, Examples 1 and 6
From the cylindrical block-shaped glass block obtained by the method for producing a glass material of Example 1, 3 samples of Example 1, 4 samples of Example 1, and 6 samples of Example 6 were obtained, and the ultraviolet transmittance was measured. FIG. 7 shows the result.

In FIG. 7, as in FIG. 6, the transmittance of the samples of Example 1 and Example 4 at a wavelength of 365 nm was about 81.8% to 83.0%. The transmittance of the sample of Example 6 at a wavelength of 365 nm was 90.2%, which was higher than the samples of 3 of Example 1 and 4 of Example 1 above.

In any of the glass blocks, bubbles, foreign matter,
There was no striae, the coloring of the glass block was reduced as compared with the related art, and a high ultraviolet transmittance was exhibited. In particular, the samples of Examples 5 and 6 using the reducing agent are more prevented from being colored and have a higher transmittance at a wavelength of 365 nm than the samples of Examples 1 to 4 using no reducing agent, This indicates that coloring caused by iron impurities is almost eliminated. The four samples of Example 1 were manufactured in the same manner in terms of the manufacturing method, but the transmittance was different due to slight variations in manufacturing conditions, but an appropriate amount of the Si reducing agent was added ( (Samples of Example 5 and Example 6)
By doing so, it became clear that a cullet-shaped glass lump of 1 cm × 1 cm × 1 cm can achieve a transmittance of 90% or more at a wavelength of 365 nm.

Examples 7 to 9 From the cylindrical block-shaped glass blocks obtained in Examples 1, 5 and 6, cylindrical block-shaped glass blocks having a diameter of about 60 mm and a length of about 90 mm were respectively obtained. I cut it out.
The cut glass lump of Example 1 was put into a platinum spinning furnace and heated to about 1100 ° C. to remelt the glass lump (viscosity of about 1000 poise). Next, the re-melted glass was spun to obtain a diameter of 125 μm and a length of 1 μm.
The glass fibers of Examples 7, 8 and 9 which were 00 mm were produced.

With respect to the glass fibers of Examples 7 to 9, the internal transmittance at an ultraviolet ray having a wavelength of 365 nm was measured. Since such a monofilament type glass fiber cannot be measured by a cutback method using a normal optical spectrum analyzer, the transmittance was measured by the method described below. That is, in this measurement method, (1) cutback is performed from the incident end of the measured fiber, and (2) there is no leakage light due to bending of the measured fiber (a predetermined slack range in the holding state of the measured fiber, etc.). )) And the transmittance is measured, and (3)
This is a method for removing organic substances existing on the measured fiber before measuring the transmittance of the measured fiber. By such a method, the transmittance of the measured fiber was measured.

The glass fiber of Example 7 obtained by using the glass lump obtained in Example 1 has a wavelength of 365 nm.
At m, ultraviolet light was transmitted at a transmittance of about 89.2%. That is, there was no bubble, foreign matter, or striae in the glass fiber, the coloring of the fiber was reduced as compared with the related art, and a high ultraviolet transmittance could be achieved.

The glass fiber of Example 8 obtained by using the glass lump obtained in Example 5 has a wavelength of 365 nm.
m, a high transmittance of about 96.0% was exhibited. In other words, this indicates that the glass fiber has no bubbles, foreign matter, or striae, and has little coloring due to iron impurities.

The glass fiber of Example 9 obtained using the glass lump obtained in Example 6 has a wavelength of 365 nm.
m, a high transmittance of about 97.0% was exhibited. That is, there is no bubble, foreign matter, or striae in the glass fiber, indicating that coloring by iron impurities is further reduced.

Further, the glass fibers thus obtained (Examples 7, 8, and 9) were examined for solarization resistance. For any of the above glass fibers, using a black light, ultraviolet light, minutes, hours, tens of hours,
Irradiate each and the wavelength 365 after each lapse of time
When the change in the transmittance near nm was measured, the deterioration due to solarization was about 2%, and it was confirmed that the solarization resistance was good.

[0132]

The glass material of the present invention uses SiO ₂ as a base glass component, determines the allowable amount of an alkali component in the glass material from the viewpoint of deterioration of photocatalytic activity, further transmits ultraviolet rays with high transmittance, and It is easy to form a thin film, and has excellent chemical durability, heat resistance, light transmission characteristics, etc., and uses a glass composition that can be manufactured at low cost, making it a suitable glass fiber material as a glass material for supporting a photocatalyst. It is useful as a glass material and the glass fiber. Further, by adjusting the composition of the glass material, a glass material for supporting a photocatalyst having characteristics such as a thin glass fiber can be easily obtained and excellent in heat resistance can be obtained at low cost. Moreover,
When the glass composition is configured as in the present invention, fining can be performed without adding a defoaming agent, so that fining can be performed efficiently and As ₂ O ₃ , Sb ₂ O ₃ , S
Since a glass material can be manufactured without using harmful substances such as nO _2, it is possible to cope with environmental problems.

In the production of the glass material of the present invention, a one-stage melting method is employed, and a fining and homogenizing treatment is performed using a crucible made of a material other than platinum such as a silica crucible. The vitrification temperature can be lowered, and the glass material is not colored. Particularly in the fining and homogenization steps, bubbles in the glass material immediately after vitrification can be efficiently eliminated. In other words, by using a high-purity batch raw material and creating a reducing atmosphere by vitrification, fining and homogenization, it is possible to prevent coloring of the glass material even if the crucible is kept at a high temperature for a long time. A transparent glass material can be realized. Further, the glass material thus obtained is softened at a low temperature, and by performing a spinning treatment, the coloring of the glass fiber is prevented,
A glass fiber that can transmit high ultraviolet light and is suitable for supporting a photocatalyst can be realized.

[Brief description of the drawings]

FIG. 1 (SiO ₂ + B ₂ O ₃ ) —MgO—Al ₂ O ₃ system
(SiO ₂ + B ₂ O ₃ )-(MgO + CaO) -Al ₂ O ₃
System, (SiO ₂ + B ₂ O ₃ ) + CaO-Al ₂ O ₃ system, (S
iO ₂ + B ₂ O ₃₎ glass region in -BaO-Al ₂ O ₃ system, which is a schematic diagram of the range of the melting temperature and liquidus temperature.

FIG. 2 is a graph showing in chronological order one example of a relationship between time and temperature in a manufacturing process of a general glass material and a glass fiber.

FIG. 3 is a graph showing different examples of a spectral transmittance curve of a glass material.

FIG. 4 is a graph showing in chronological order one example of a relationship between time and temperature in the step (B) and the glass fiber manufacturing step in the manufacture of the glass material and the glass fiber of the present invention.

FIG. 5 is a graph showing the spectral transmittance characteristics of a glass material manufactured by changing the parameters according to the present invention from the conventional glass material manufacturing method in order under the same glass material composition and the respective glass material manufacturing conditions. It is.

FIG. 6 is an ultraviolet transmittance graph of the samples of Example 1, Example 1, Example 2 and Example 5 in the test example.

FIG. 7 is a graph showing ultraviolet transmittance of samples of Examples 1 to 3, Examples 1 to 4 and Example 6 in a test example.

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[Procedure amendment]

[Submission date] August 25, 2000 (2008.2
5)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0011

[Correction method] Change

[Correction contents]

[0011] The first stage of melting is a step performed for the purpose of vitrifying a raw material mixture (hereinafter sometimes referred to as a batch raw material).
A high-purity raw material containing impurities of about 2 ppm , which is a high-purity purified product, is used. Then, a high-purity raw material, such as a hydroxide, a carbonate, a nitrate, a sulfide, an oxide, a nitride, a defoaming agent and the like are blended in a predetermined ratio to prepare a batch raw material. Usually, it is heated to about 1400 ° C. in a quartz crucible (hereinafter sometimes referred to as a silica crucible) (point a in FIG. 2) and melted for about 7 to 9 hours (FIG. 2).
At point b), vitrification is performed. In the purification of the batch raw material, contact with a metal is generally avoided during blending and melting, and dust is prevented from being mixed in the storage and storage of the raw material and the batch raw material. At this time, since the glass material is heated and melted at a high temperature and vitrified, the reactivity of the batch material becomes very high, and gas components such as CO ₂ and NO ₂ are generated in the batch material in the vitrification process, and countless Bubbles are generated. Then, while stirring these foams while leaving them in the molten glass in the vitrification process, the glass is shaped (point b in FIG. 2), and the glass is quenched (point c in FIG. 2). A cullet-shaped glass block having a size of 1 cm × 1 cm is obtained.

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0040

[Correction method] Change

[Correction contents]

The base glass component is SiO ₂ , but in producing a glass material, B ₂ O ₃ is used for ensuring glass formation, glass melting property and devitrification resistance, and Al ₂ O ₃ is used for producing glass material. , Glass formation, chemical durability, devitrification resistance, and glass transition temperature. The glass material of the present invention further contains an alkaline earth metal oxide for lowering the viscosity of the glass and an additive for adjusting various properties of the glass material under the melting conditions.

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0041

[Correction method] Change

[Correction contents]

Next, (SiO ₂ )-(Al ₂ O ₃ )-(B ₂
Alkaline earth metal oxides for lowering the viscosity, which are contained in an O ₃ ) -based glass material, were studied. here,
In the (SiO ₂ )-(Al ₂ O ₃ )-(B ₂ O ₃ ) -based glass material, in order not to deteriorate the photocatalytic activity, it is made non-alkali or low alkali, so that Na ₂ O—
In a glass system containing 0 or a small amount of K ₂ O , the vitrification region of the alkaline earth metal oxide was experimentally examined. However, in this case, a high atomic weight component such as Pb and a high valence component such as La, W, Ta, and Nb whose wavelength absorption edge is on the longer wavelength side are excluded, and T is an ultraviolet absorbing component.
Investigations were conducted except for transition metals such as i and Zr, and Zn, As, Sb, and Sn. Then, based on the above-mentioned method for producing a glass material, the raw materials were prepared, melted at a high temperature, and quenched to determine whether or not a transparent glass was obtained. The composition in the vitrification limit region is where the melting temperature and the liquidus temperature (LT) are the same. Further, in the method of manufacturing a glass material, the melting temperature required in the vitrification step and the fining / homogenization step can be made as low as possible without devitrification, and from the viewpoint that the LT is as low as possible, It is necessary to select an alkaline earth metal oxide to be added as a raw material for the above. As for LT, as described above, in consideration of the temperature to be applied in the manufacturing process of the glass material and the glass fiber of the present invention,
It is important to select a glass composition that does not devitrify (about 1200 ° C. or less).

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0044

[Correction method] Change

[Correction contents]

As the glass material of the present invention, a glass material having a narrow range of devitrification temperature and a high minimum temperature of devitrification temperature is selected. This is to select the most suitable alkaline earth metal oxide for the glass material of the present invention. For example, the direction of the absence of crystals can be predicted by the crystal shape, the crystallization speed can be assumed by the amount of crystals, and the position of the crystals can be assumed to prevent the precipitation of crystals from the stability of the crystals. be able to. The method for selecting the composition of the glass material of the present invention will be described below with reference to FIG.

[Procedure amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0058

[Correction method] Change

[Correction contents]

In the glass material of the present invention containing SiO ₂ , Al ₂ O ₃ , B ₂ O ₃ and CaO as essential components, SiO ₂ , A
When the total content of l ₂ O ₃ and B ₂ O ₃ , that is, the content of the network former is less than 59% by weight, the components other than the network former forming the glass material become 41%.
% By weight, but if it is composed of an alkaline earth metal oxide and a small amount of an alkali metal oxide , the glass transition temperature may decrease, and a substance other than the alkaline earth metal oxide may be used. In such a case, there is a possibility that a situation may occur in which glass formation becomes impossible due to deterioration of ultraviolet transmittance, decrease of viscoelasticity, and the like. On the other hand, if the content of the components other than the network former exceeds 90% by weight, the viscosity increases. At this time, the rest of the components forming the glass material is less than 10 wt%, the alkaline earth metal oxide it
When it is composed of a compound and a small amount of an alkali metal oxide , the viscosity may increase and the meltability may deteriorate. Further, in this case, even if the alkaline earth metal oxide is composed of a low molecular weight component, the viscosity is reduced and the devitrification is deteriorated, so that it is difficult to form a glass by any method. Therefore, the total content of SiO ₂ , Al ₂ O ₃ and B ₂ O ₃ is 59 to 90% by weight.

[Procedure amendment 6]

[Document name to be amended] Statement

[Correction target item name] 0105

[Correction method] Change

[Correction contents]

[0105] As a method of the glass fibers manufactured by the manufacturing method of a glass fiber carrying a photocatalyst of the present invention, for example, a sol-gel method, Pas Lee Rozoru method, Wash-coating, vapor deposition, sputtering, pyrogenic And a metal oxidation method. The film thickness is usually about 1 nm to 1 mm. The wavelength and intensity of the light applied to the photocatalyst can be appropriately selected according to the type of the photocatalyst. For example, if the photocatalyst is TiO ₂ , it can excite the photocatalyst.
00 nm UV light is preferred. As a light source, a mercury lamp, a mercury-xenon lamp, or the like can be used.

[Procedure amendment 7]

[Document name to be amended] Statement

[Correction target item name] 0126

[Correction method] Change

[Correction contents]

Examples 7 to 9 From the cylindrical block-shaped glass blocks obtained in Examples 1, 5 and 6, cylindrical block-shaped glass blocks having a diameter of about 60 mm and a length of about 90 mm were respectively obtained. I cut it out.
The cut out glass pieces of Examples 1 , 5 and 6 were put into a platinum spinning furnace and heated to about 1100 ° C. to re-melt the glass pieces (viscosity of about 1000 poise). Next, the re-melted glass was spun to obtain a diameter of 1 mm.
Examples 7, 8 and 9 which are 25 μm and 100 mm in length
Was produced.

[Procedure amendment 8]

[Document name to be amended] Drawing

[Correction target item name] Fig. 5

[Correction method] Change

[Correction contents]

FIG. 5

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C03C 3/091 C03C 3/091 F term (Reference) 4G062 AA05 BB01 BB05 BB06 DA05 DA06 DB03 DB04 DC03 DC04 DD01 DD02 DE01 DF01 DF02 EA01 EA02 EA03 EB01 EB02 EB03 EC01 EC02 EC03 ED01 ED02 ED03 EE03 EE04 EE05 EF01 EF02 EF03 EG01 EG02 EG03 FA01 FA10 FB01 GC01 FC01 F01 F02 F01 F01 F02 F01 F01 F01 F01 F01 F02 HH05 HH07 HH08 HH09 HH11 HH13 HH15 HH17 HH20 JJ01 JJ03 JJ04 JJ05 JJ07 JJ10 KK01 KK02 KK03 KK04 KK05 KK07 KK10 MM40 NN16 4G069 AA01 AA03 AA08 BA04B BA14A BA14B03 EB01 EB01 CB01

Claims (16)

[Claims] 1. A method according to claim 1, wherein said SiO _{2 is} 35 to 60% by weight.
_{l 2 O 3 4~30%, B} 2 O 3 4~25%, CaO 4
A glass material containing -40% and an alkali metal oxide of 0-10%, and having an iron content of 50 ppm or less as Fe. 2. At a thickness of 10 mm, a wavelength of 365 n
The glass material according to claim 1, wherein an ultraviolet transmittance of m is 80% or more. 3. SiO ₂ 49-56% by weight, A
_{l 2 O 3 12~17%, B} 2 O 3 6~14% and Ca
The glass material according to claim 1, comprising 16 to 25% of O. 4. The composition according to claim 1, wherein the weight percentages are SiO ₂ , Al ₂ O ₃ and B _2.
Glass material according to claim 1, 2 or 3 the total content of O ₃ is 59 to 90%. 5. The method according to claim 1, wherein in weight percent, SiO ₂ , Al ₂ O ₃ , B ₂ O ₃
The glass material according to any one of claims 1 to 4, wherein the total content of CaO and CaO is 85 to 100%. 6. Other components include MgO and Ba.
O, and at least one selected from the group consisting of SrO, the content of which is% by weight, MgO 0 to 8%, BaO
0 to 10% and SrO 0 to 10%, and their total content is 15% or less.
The glass material according to any one of the above. 7. The glass material according to claim 1, comprising 0 to 10% by weight of K ₂ O. 8. PbO, ZrO as further components
_{2, TiO 2, La 2 O} 3, P 2 O 5, WO 3, Bi 2 O 3, T
_{a 2 O 5, Nb 2 O} 5, Gd 2 O 3 and glass material according to any one of claims 1 to 7 comprising at least one member selected from the group consisting of F. 9. As another component, As ₂ O ₃ , Sn
The glass material according to any one of claims 1 to 8, comprising at least one selected from O ₂ and Sb ₂ O ₃ . (A) a step of melting the raw material mixture into a glassy state; (B) a step of melting the glassy state melt obtained in the step (A) without solidifying it in a crucible made of a platinum-free material. The glass material according to any one of claims 1 to 9, which is obtained by a step of forming after fining and homogenizing, and a step of (C) cooling the formed article to obtain a glass lump. 11. The glass material according to claim 10, wherein the melting of the raw material mixture in the step (A) is performed in a crucible made of a material not containing platinum. 12. The glass material according to claim 10, wherein the steps (A) and (B) are performed in a reducing atmosphere. 13. The glass material according to claim 12, wherein the reducing atmosphere is formed by mixing a reducing agent into the raw material mixture or adding the reducing agent to the glassy melt in the step (A). 14. The method according to claim 1, which is used for supporting a photocatalyst.
14. The glass material according to any one of items 13 to 13. 15. A glass fiber obtained by spinning the glass material according to claim 1 in a spinning furnace. 16. The method according to claim 1, which is used for supporting a photocatalyst.
6. The glass fiber according to 5.