JP2022159240A - Glass member and method for producing the same - Google Patents

Abstract

To provide a glass member and a method for producing the same that can suppress elution of antibacterial ions.SOLUTION: A glass member according to the present invention comprises a glass plate having a first surface and a second surface, and an antibacterial film formed on the first surface, and the antibacterial film contains a binder containing metal oxide constituting three-dimensional network bond, and antibacterial metal ions.SELECTED DRAWING: Figure 2

Description

TECHNICAL FIELD The present invention relates to a glass member and a manufacturing method thereof.

Patent Literature 1 discloses a glass in which an antibacterial ion component is ion-exchanged to provide an antibacterial substance on the surface of a glass plate.

JP-A-11-228186

However, the glass plate implanted with antibacterial ions as disclosed in Patent Document 1 has a problem that the ions are easily eluted. The present invention has been made to solve this problem, and an object of the present invention is to provide a glass member and a method for manufacturing the same that can suppress the elution of antibacterial ions.

Section 1. a glass plate having a first side and a second side;
an antibacterial film formed on the first surface;
with
The antibacterial membrane is
a binder containing a metal oxide that forms a three-dimensional network bond;
an antibacterial metal ion;
A glass member containing

Section 2. Item 2. The glass member according to Item 1, wherein the antibacterial film contains 1% by mass or more of the antibacterial ion.

Item 3. Item 3. The glass member according to Item 1 or 2, wherein the antibacterial film contains at least one kind of fine particles.

Section 4. Item 4. The glass member according to Item 3, wherein the antibacterial film contains 60% by mass or more of the fine particles.

Item 5. Item 5. The glass member according to Item 3 or 4, wherein the antibacterial film contains a plurality of types of the fine particles.

Item 6. Item 6. The glass member according to Item 5, wherein the plurality of types of fine particles have different average particle sizes.

Item 7. Item 7. The glass member according to Item 6, wherein, among the plurality of kinds of fine particles, the fine particles having the largest average particle size have a maximum diameter larger than the film thickness of the antibacterial film.

Item 8. Item 8. The glass member according to any one of Items 1 to 7, wherein the antibacterial ion is a monovalent or divalent copper ion.

Item 9. Item 9. The glass member according to any one of Items 1 to 8, wherein the antibacterial film contains a plurality of types of fine particles, and one of the plurality of types of fine particles is a photocatalyst fine particle.

Item 10. Item 10. The glass member according to Item 9, wherein the photocatalyst fine particles are made of _TiO2 .

Item 11. forming a coating liquid by adding photocatalyst fine particles and antibacterial metal ions to silicon alkoxide;
a step of irradiating the coating liquid with ultraviolet light;
applying the coating liquid to a glass plate;
heating the glass plate coated with the coating liquid;
A method for manufacturing a glass member, comprising:

According to the present invention, elution of antibacterial ions can be suppressed.

It is a sectional view showing one embodiment of the glass member concerning the present invention. FIG. 2 is a cross-sectional view showing an example of a schematic diagram of the antibacterial film of FIG. 1; 4 is a graph showing changes over time in the amount of eluted copper ions in Examples 1 to 3. FIG. 10 is a graph showing changes over time in the amount of eluted copper ions in Examples 4 and 5. FIG. 1 is a SEM photograph of the surface and cross section of the antibacterial film of Example 1. FIG.

Hereinafter, one embodiment of the glass member according to the present invention will be described with reference to the drawings. The glass member according to the present embodiment can be used in various applications such as, for example, as a glass member for covering an article or as a part of a structure. In addition to general displays, for example, goods include mobile PCs, tablet PCs, in-vehicle devices such as car navigation systems, devices that at least partially have a display function using electronic components, and external displays that do not have an electronic display function. Various devices such as a display device for displaying some kind of display are targeted. In addition, even if it is not a device, for example, a product to be shown to the outside, such as a product, is also a target. Examples of the above structures include various structures using glass, such as buildings, cases such as showcases, glass plates of copiers, partitions, and the like.

FIG. 1 is a cross-sectional view of a glass member. As shown in FIG. 1, a glass member 10 according to this embodiment includes a glass plate 1 having a first surface and a second surface, and an antibacterial film 2 laminated on the first surface of the glass plate 1. ing. When this glass member 10 is used as a cover member, it is arranged so as to cover the article 100 described above. At this time, the second surface of the glass plate 1 is arranged to face the article 100, and the antibacterial film 2 is arranged to face the outside. A detailed description will be given below.

<1. Glass plate>
The glass plate 1 can be made of general-purpose soda-lime glass, borosilicate glass, aluminosilicate glass, alkali-free glass, or other glass, for example. Further, the glass plate 1 can be formed by a float method. According to this manufacturing method, a glass plate 1 having a smooth surface can be obtained. However, the glass plate 10 may have unevenness on its main surface, and may be a figured glass, for example. A figured glass can be molded by a manufacturing method called a roll-out method. A figured glass produced by this method usually has periodic irregularities in one direction along the main surface of the glass plate.

In the float method, molten glass is continuously supplied onto a molten metal such as molten tin, and the supplied molten glass is made to flow on the molten metal to form a strip. The glass thus formed is called a glass ribbon.

The glass ribbon is cooled toward the downstream side, cooled and solidified, and then pulled up from the molten metal by rollers. Then, it is conveyed to a slow cooling furnace by rollers, and cut after slow cooling. A float glass sheet is thus obtained.

The thickness of the glass plate 1 is not particularly limited, but a thinner one is preferable for weight reduction. For example, it is preferably 0.3 to 5 mm, more preferably 0.6 to 2.5 mm. This is because if the glass plate 10 is too thin, the strength will decrease, and if it is too thick, the article 100 viewed through the glass member 10 may be distorted.

The glass plate 1 may generally be a flat plate, but may be a curved plate. In particular, when the surface shape of the protected member to be protected is non-planar such as a curved surface, the glass plate 1 preferably has a non-planar main surface that conforms thereto. In this case, the glass plate 1 may be bent so as to have a constant curvature as a whole, or may be bent locally. The main surface of the glass plate 1 may be configured by, for example, connecting a plurality of flat surfaces with curved surfaces. The radius of curvature of the glass plate 1 can be, for example, 5000 mm or less. The lower limit of the radius of curvature can be, for example, 10 mm or more, but it may be even smaller, for example, 1 mm or more, especially in a locally bent portion.

A glass plate having the following composition can also be used. Hereinafter, unless otherwise specified, percentages indicating the components of the glass plate 1 all mean mol%. In the present specification, the phrase “substantially composed of” means that the total content of the listed components is 99.5% by mass or more, preferably 99.9% by mass or more, more preferably 99.95% by mass. It means that it occupies more than % by mass. “Substantially free” means that the content of the component is 0.1% by mass or less, preferably 0.05% by mass or less.

Based on the composition of float plate glass (hereinafter sometimes referred to as "SL in a narrow sense" or simply "SL"), which is widely used as a glass composition suitable for the production of glass plates by the float method, the inventor of the present invention , the composition range considered by those skilled in the art to be soda lime silicate glass suitable for the float process (hereinafter sometimes referred to as “broadly defined SL”), specifically within the following mass% range in which the properties such as T ₂ and T ₄ are approximated to SL in the narrow sense as much as possible while improving the chemical strengthening properties of SL in the narrow sense.
SiO ₂ 65-80%
Al ₂ O ₃ 0-16%
MgO 0-20%
CaO 0-20%
Na ₂ O 10-20%
_K2O 0-5%

Each component constituting the glass composition of the glass plate 1 will be described below.
( _SiO2 )
SiO ₂ is a main component that constitutes the glass plate 1. If the content is too low, the chemical durability such as water resistance and heat resistance of the glass are lowered. On the other hand, if the SiO ₂ content is too high, the viscosity of the glass plate 1 at high temperatures becomes high, making melting and molding difficult. Therefore, the content of SiO ₂ is suitably in the range of 66-72 mol %, preferably 67-70 mol %.

_{( Al2O3} )
Al ₂ O ₃ improves the chemical durability such as water resistance of the glass plate 1, and facilitates the movement of alkali metal ions in the glass to increase the surface compressive stress after chemical strengthening. It is a component for deepening the depth. On the other hand, if the content of Al ₂ O ₃ is too high, the viscosity of the glass melt will increase, T ₂ and T ₄ will increase, and the clarity of the glass melt will deteriorate, making it difficult to produce a high-quality glass plate. becomes difficult.

Therefore, the content of Al ₂ O ₃ is appropriately in the range of 1 to 12 mol %. The content of Al ₂ O ₃ is preferably 10 mol % or less, preferably 2 mol % or more.

(MgO)
MgO is an essential component for improving the meltability of glass. From the viewpoint of sufficiently obtaining this effect, the glass plate 1 preferably contains MgO. Moreover, when the content of MgO is less than 8 mol %, the surface compressive stress after chemical strengthening tends to decrease and the depth of the stress layer tends to become shallow. On the other hand, if the content is increased beyond the appropriate amount, the strengthening performance obtained by chemical strengthening is lowered, and in particular the depth of the surface compressive stress layer is sharply reduced. Among the alkaline earth metal oxides, MgO has the least adverse effect, but in this glass plate 1, the content of MgO is 15 mol % or less. Moreover, when the content of MgO is high, T ₂ and T ₄ are increased and the clarity of the glass melt is deteriorated, making it difficult to produce a high-quality glass plate.

Therefore, in this glass plate 1, the content of MgO is in the range of 1 to 15 mol %, preferably 8 mol % or more and 12 mol % or less.

(CaO)
CaO has the effect of lowering the viscosity at high temperatures, but if the content is too high beyond an appropriate range, the glass plate 1 tends to devitrify and the movement of sodium ions in the glass plate 1 is inhibited. end up When CaO is not contained, the surface compressive stress after chemical strengthening tends to decrease. On the other hand, if the CaO content exceeds 8 mol %, the surface compressive stress after chemical strengthening is significantly reduced, the depth of the compressive stress layer is significantly reduced, and the glass plate 1 is likely to devitrify.

Therefore, the appropriate CaO content is in the range of 1 to 8 mol %. The CaO content is preferably 7 mol % or less, and preferably 3 mol % or more.

(SrO, BaO)
SrO and BaO greatly lower the viscosity of the glass plate 1, and when contained in small amounts, the effect of lowering the liquidus temperature _TL is more pronounced than CaO. However, even if added in very small amounts, SrO and BaO significantly hinder the movement of sodium ions in the glass plate 1, greatly reduce the surface compressive stress, and make the depth of the compressive stress layer considerably shallow.

Therefore, it is preferable that this glass plate 1 does not substantially contain SrO and BaO.

( _Na2O )
Na ₂ O is a component for increasing the surface compressive stress and increasing the depth of the surface compressive stress layer by replacing sodium ions with potassium ions. However, if the content is increased beyond the appropriate amount, the stress relaxation during the chemical strengthening treatment will exceed the generation of surface compressive stress due to ion exchange during the chemical strengthening treatment, and as a result, the surface compressive stress will tend to decrease. be.

Further, Na ₂ O is a component for improving the solubility and lowering T ₄ and T ₂ , but if the content of Na ₂ O is too high, the water resistance of the glass is remarkably lowered. In the glass plate 1, if the content of Na ₂ O is 10 mol % or more, the effect of reducing T ₄ and T ₂ is sufficiently obtained, and if it exceeds 16 mol %, the surface compressive stress is significantly reduced due to stress relaxation. Become.

Therefore, the content of Na ₂ O in the glass plate 1 of this embodiment is appropriately in the range of 10 to 16 mol %. The Na ₂ O content is preferably 12 mol % or more, and more preferably 15 mol % or less.

₍ K2O)
K ₂ O, like Na ₂ O, is a component that improves the solubility of glass. In addition, in the range where the K ₂ O content is low, the ion exchange rate in chemical strengthening increases, the depth of the surface compressive stress layer increases, and the liquidus temperature _TL of the glass plate 1 decreases. Therefore, it is preferable to contain K ₂ O at a low content.

On the other hand, K ₂ O is less effective than Na ₂ O in reducing T ₄ and T ₂ , but a large amount of K ₂ O inhibits clarification of the glass melt. Also, the higher the K ₂ O content, the lower the surface compressive stress after chemical strengthening. Therefore, the appropriate K ₂ O content is in the range of 0 to 1 mol %.

₍ Li2O)
Li ₂ O significantly reduces the depth of the compressive stress layer even if it is contained in a small amount. Further, when a glass member containing Li ₂ O is chemically strengthened with a molten salt of potassium nitrate alone, the deterioration rate of the molten salt is significantly faster than that of a glass member containing no Li ₂ O. Specifically, when the chemical strengthening treatment is repeatedly performed with the same molten salt, the surface compressive stress formed on the glass surface decreases with a smaller number of times. Therefore, the glass plate 1 of the present embodiment may contain Li ₂ O in an amount of 1 mol % or less, but preferably does not substantially contain Li ₂ O.

_{( B2O3} )
B ₂ O ₃ is a component that lowers the viscosity of the glass plate 1 and improves its solubility. However, if the content of B ₂ O ₃ is too high, the glass plate 1 tends to undergo phase separation and the water resistance of the glass plate 1 decreases. In addition, the compound formed by B ₂ O ₃ and the alkali metal oxide may volatilize and damage the refractories in the glass melting chamber. Furthermore, the inclusion of B ₂ O ₃ reduces the depth of the compressive stress layer in chemical strengthening. Therefore, the appropriate content of B ₂ O ₃ is 0.5 mol % or less. In the present invention, it is more preferable that the glass plate 1 does not substantially contain B ₂ O ₃ .

_{( Fe2O3} )
Fe usually exists in the glass in the form of Fe ²⁺ or Fe ³⁺ and acts as a colorant. Fe ³⁺ is a component that enhances the ultraviolet absorption performance of the glass, and Fe ²⁺ is a component that enhances the heat ray absorption performance. When the glass plate 1 is used as a cover glass for a display, it is required that the coloring be inconspicuous, so the Fe content is preferably as low as possible. However, Fe is often inevitably mixed with industrial raw materials. Therefore, the iron oxide content in terms of Fe ₂ O ₃ is preferably 0.15% by mass or less, more preferably 0.1% by mass or less, when the entire glass plate 1 is taken as 100% by mass. It is preferably 0.02% by mass or less, more preferably 0.02% by mass or less.

( _TiO2 )
TiO ₂ is a component that lowers the viscosity of the glass plate 1 and increases the surface compressive stress due to chemical strengthening. Therefore, the appropriate content of TiO ₂ is 0 to 0.2% by mass. In addition, it is inevitably mixed with commonly used industrial raw materials, and may be contained in the glass plate 1 in an amount of about 0.05% by mass. This level of content does not color the glass, so it may be included in the glass plate 1 of the present embodiment.

₍ ZrO2)
ZrO ₂ may be mixed into the glass plate 1 from the refractory bricks constituting the glass melting kiln, especially when the glass plate is manufactured by the float method, and its content is about 0.01% by mass. Are known. On the other hand, ZrO ₂ is a component that improves the water resistance of glass and increases surface compressive stress due to chemical strengthening. However, a high ZrO ₂ content may cause an increase in the working temperature T ₄ and a rapid increase in the liquidus temperature _TL . It tends to remain as a foreign substance in the manufactured glass. Therefore, the appropriate ZrO ₂ content is 0 to 0.1% by mass.

₍ SO3)
In the float method, sulfates such as Glauber's salt (Na ₂ SO ₄ ) are commonly used as clarifiers. Sulfate decomposes in the molten glass to produce gas components, which promotes defoaming of the glass melt, but some of the gas components dissolve and remain in the glass plate 1 as SO ₃ . In the glass plate 1 of the present invention, SO ₃ is preferably 0 to 0.3% by mass.

₍ CeO2)
CeO ₂ is used as a fining agent. _{CeO 2} contributes to degassing since it produces O ₂ gas in the molten glass. On the other hand, too much CeO ₂ causes the glass to turn yellow. Therefore, the CeO ₂ content is preferably 0 to 0.5% by mass, more preferably 0 to 0.3% by mass, and even more preferably 0 to 0.1% by mass.

₍ SnO2)
It is known that in a glass sheet molded by the float method, tin diffuses from the tin bath to the surface that comes into contact with the tin bath during molding, and the tin exists as SnO ₂ . Also, SnO ₂ mixed with the glass raw material contributes to defoaming. In the glass plate 1 of the present invention, SnO ₂ is preferably 0 to 0.3% by mass.

(other ingredients)
Preferably, the glass plate 1 according to the present embodiment is substantially composed of the components listed above. However, the glass plate 1 according to the present embodiment may contain components other than the components listed above, preferably within a range where the content of each component is less than 0.1% by mass.

_Examples of components that _are allowed to be included include _As2O5 , _Sb2O5 , _Cl , and F, which are added for the purpose of defoaming the molten glass _, in addition to SO3 and SnO2 described above. However, As ₂ O ₅ , Sb ₂ O ₅ , Cl, and F are preferably not added because they have a large adverse effect on the environment. Further, other examples that _are allowed to be included _are ZnO _{, P2O5 , GeO2 , Ga2O3} , Y2O3 and _La2O3 . Components other than the above derived from industrially used raw materials are acceptable as long as they do not exceed 0.1% by mass. Since these components are added as appropriate or mixed inevitably as necessary, the glass plate 1 of the present embodiment may be substantially free of these components. do not have.

(Density (specific gravity): d)
From the above composition, in this embodiment, the density of the glass plate 1 is reduced to 2.53 g·cm ⁻³ or less, further 2.51 g·cm ⁻³ or less, and in some cases 2.50 g·cm ⁻³ or less. be able to.

In the float method, if there is a large difference in density between different types of glass, the molten glass with the higher density stays at the bottom of the melting furnace when switching the type of glass to be manufactured, which may hinder the switching of types. . The density of soda-lime glass currently mass-produced by the float method is about 2.50 g·cm ⁻³ . Therefore, considering mass production by the float method, the density of the glass plate 1 should be close to the above values, specifically 2.45 to 2.55 g·cm ⁻³ , particularly 2.47 to 2.53 g·cm −3 . cm ⁻³ is preferred, and 2.47 to 2.50 g·cm ⁻³ is more preferred.

(Elastic modulus: E)
When chemical strengthening with ion exchange is performed, the glass substrate may warp. In order to suppress this warp, it is preferable that the elastic modulus of the glass plate 1 is high. According to the present invention, the elastic modulus (Young's modulus: E) of the glass plate 1 can be increased to 70 GPa or higher, or even 72 GPa or higher.

Chemical strengthening of the glass plate 1 will be described below.
(Chemical strengthening conditions and compressive stress layer)
A glass plate 1 containing sodium is brought into contact with a molten salt containing monovalent cations having an ionic radius larger than that of sodium ions, preferably potassium ions, so that the sodium ions in the glass plate 1 are replaced with the above monovalent cations. The chemical strengthening of the glass plate 1 according to the present invention can be carried out by performing an ion-exchange treatment that replaces with . Thereby, a compressive stress layer having a compressive stress applied to the surface is formed.

Potassium nitrate can typically be mentioned as the molten salt. A mixed molten salt of potassium nitrate and sodium nitrate can also be used, but since it is difficult to control the concentration of the mixed molten salt, a molten salt of potassium nitrate alone is preferable.

The surface compressive stress and compressive stress layer depth in the tempered glass member can be controlled not only by the glass composition of the article, but also by the molten salt temperature and treatment time in the ion exchange treatment.

By contacting the above glass plate 1 with a potassium nitrate molten salt, a tempered glass member having a very high surface compressive stress and a very deep compressive stress layer can be obtained. Specifically, a tempered glass member having a surface compressive stress of 700 MPa or more and a compressive stress layer having a depth of 20 μm or more can be obtained. Certain tempered glass members can also be obtained.

In addition, when using the glass plate 1 with a thickness of 3 mm or more, it is possible to use wind tempering as a general strengthening method instead of chemical strengthening.

<2. Antibacterial membrane>
Next, the antibacterial film 2 will be described with reference to FIG. FIG. 2 is an enlarged cross-sectional view schematically showing the vicinity of the surface of the antibacterial film. The antibacterial film 2 comprises an inorganic oxide that forms a three-dimensional network bond, at least one kind of inorganic oxide fine particles held in the inorganic oxide, and an antibacterial metal ion held in the inorganic oxide. I have. These will be described below.

<2-1. Inorganic oxide>
The inorganic oxide serves as a binder that holds the inorganic oxide fine particles and metal ions. The inorganic oxide includes, for example, silicon oxide, which is an oxide of Si, and preferably contains silicon oxide as a main component. Using silicon oxide as a main component is suitable for lowering the refractive index of the film and suppressing the reflectance of the film. The antibacterial film may contain a component other than silicon oxide, or may contain a component partially containing silicon oxide.

The component partially containing silicon oxide forms, for example, a three-dimensional network structure of siloxane bonds (Si--O--Si) in which silicon atoms and oxygen atoms are alternately connected and spread three-dimensionally. Also, it is a component in which atoms other than both atoms, functional groups, and the like are bonded to silicon atoms or oxygen atoms in this portion. Examples of atoms other than silicon atoms and oxygen atoms include nitrogen atoms, carbon atoms, hydrogen atoms, and metal elements described in the next paragraph. Examples of functional groups include organic groups described as R in the next paragraph. Such components are not strictly silicon oxides in that they are not composed solely of silicon and oxygen atoms. However, in describing the properties of the antibacterial film 2, it is appropriate to treat the silicon oxide portion composed of silicon atoms and oxygen atoms as "silicon oxide", which is consistent with the common practice in the field. In this specification, the silicon oxide portion is also treated as silicon oxide. As is clear from the above description, the atomic ratio of silicon atoms and oxygen atoms in silicon oxide need not be stoichiometric (1:2).

The antimicrobial film 2 may contain metal oxides other than silicon oxide, specifically metal oxide components or metal oxide portions containing other than silicon. The metal oxide that the antibacterial film 2 may contain is not particularly limited, but for example, an oxide of at least one metal element selected from the group consisting of Al, Ti, Zr, Ta, Nb, Nd, La, Ce and Sn. is. The antibacterial film 2 may contain inorganic compound components other than oxides, such as nitrides, carbides, and halides, and may contain organic compound components.

Metal oxides, such as silicon oxide, can be formed from hydrolyzable organometallic compounds. Examples of hydrolyzable silicon compounds include compounds represented by formula (1).
RnSiY4 _{-n (} 1)
R is an organic group containing at least one selected from an alkyl group, a vinyl group, an epoxy group, a styryl group, a methacryloyl group and an acryloyl group. Y is at least one hydrolyzable organic group selected from an alkoxy group, an acetoxy group, an alkenyloxy group and an amino group, or a halogen atom. A halogen atom is preferably Cl. n is an integer from 0 to 3, preferably 0 or 1;

R is preferably an alkyl group, such as an alkyl group having 1 to 3 carbon atoms, especially a methyl group. Y is preferably an alkoxy group such as an alkoxy group having 1 to 4 carbon atoms, particularly a methoxy group and an ethoxy group. Two or more of the compounds represented by the above formulas may be used in combination. Such a combination includes, for example, a combination of a tetraalkoxysilane in which n is 0 and a monoalkyltrialkoxysilane in which n is 1.

A preferred specific example of the silicon compound having a hydrolyzable group represented by formula (I) is a silicon alkoxide in which X in formula (I) is an alkoxyl group. Further, the silicon alkoxide more preferably contains a tetrafunctional silicon alkoxide corresponding to the compound (SiX ₄ ) where m=0 in formula (I). Specific examples of tetrafunctional silicon alkoxides include tetramethoxysilane and tetraethoxysilane. The silicon alkoxide may be used alone or in combination of two or more. When two or more are used in combination, it is more preferable that the main component of the silicon alkoxide is tetrafunctional silicon alkoxide.

After hydrolysis and polycondensation, the compound represented by formula (1) forms a network structure in which silicon atoms are bonded to each other via oxygen atoms. In this structure, the organic group represented by R is included directly attached to the silicon atom.

<2-2. Inorganic oxide fine particles>
The antibacterial film 2 further contains inorganic oxide fine particles as at least part of the inorganic oxide. The inorganic oxide constituting the inorganic oxide fine particles is, for example, an oxide of at least one element selected from Si, Al, Ti, Zr, Ta, Nb, Nd, La, Ce and Sn. A plurality of kinds of inorganic oxide fine particles can also be contained. For example, a plurality of inorganic oxide fine particles having different average particle diameters can be contained. Silica fine particles, for example, can be used as the inorganic oxide fine particles having a large average particle size. Silica microparticles can be introduced into the antibacterial film 2 by adding colloidal silica, for example. The fine particles of inorganic oxide are excellent in transferring the stress applied to the antibacterial film 2 to the glass plate 1 supporting the antibacterial film 2 and have high hardness. Therefore, addition of inorganic oxide fine particles is advantageous from the viewpoint of improving the wear resistance of the antibacterial film 2 . The inorganic oxide fine particles can be supplied to the antibacterial film 2 by adding preformed inorganic oxide fine particles to the coating liquid for forming the antibacterial film 2 .

As the inorganic oxide fine particles, photocatalyst fine particles can be contained in addition to the silica fine particles described above. As the photocatalyst fine particles, for example, fine particles such as titanium oxide (TiO ₂ ) and cerium oxide (CeO ₂ ) can be used.

If the average particle diameter of the inorganic oxide fine particles is too large, the antibacterial film 2 may become cloudy. From this point of view, the average particle size of the primary particles of the inorganic oxide fine particles is preferably 1 to 200 nm, more preferably 5 to 150 nm. The average particle size of the inorganic oxide fine particles having a large particle size (for example, silica fine particles) is preferably, for example, 50 to 150 nm, more preferably 80 to 130 nm. Moreover, the average particle size of the inorganic oxide fine particles having a large particle size is preferably larger than the film thickness of the antibacterial film 2 .

On the other hand, the average particle size of the photocatalyst fine particles is smaller than the fine particles having a large average particle size such as the silica fine particles described above, and is preferably 1 to 50 nm, more preferably 5 to 30 nm.

Here, the average particle size of the inorganic oxide fine particles is described in the state of primary particles. The average particle diameter of the inorganic oxide fine particles is determined by measuring the particle diameters of 50 arbitrarily selected fine particles by observation using a scanning electron microscope and adopting the average value. If the content of the inorganic oxide fine particles is too large, the antibacterial film 2 may become cloudy. The content of the inorganic oxide fine particles in the antibacterial film 2 is preferably 60 to 90% by mass, preferably 65 to 85% by mass. The content of inorganic oxide fine particles having a large average particle size such as silica fine particles is preferably 10 to 40% by mass, more preferably 15 to 35% by mass. Also, the content of the photocatalyst fine particles is preferably 20 to 60% by mass, more preferably 25 to 55% by mass.

<2-3. Metal ion>
Metal ions have antibacterial properties and can be formed from monovalent or divalent copper ions, silver ions, and the like. The content of metal ions in the antibacterial film 2 is, for example, preferably 1 to 30% by mass of the antibacterial film, more preferably 3 to 15% by mass.

<2-4. Thickness of the antibacterial film>
The thickness of the antibacterial film 2 is, for example, preferably 10 to 500 nm, more preferably 20 to 200 nm. If the thickness is too thick, the haze ratio may increase or excessive coloring may occur. On the other hand, if the thickness is too thin, the inorganic oxide microparticles and metal ions cannot be retained and may be separated from the antibacterial film 2 . Moreover, there is also a possibility that durability may become low.

<2-5. Method for Forming Antibacterial Film>
The method of forming the antibacterial film 2 is not particularly limited, but it can be formed, for example, as follows. First, a material forming the three-dimensional network structure described above, for example, a silicon alkoxide such as tetraethoxysilane is made into a solution under acidic conditions to generate a precursor liquid. In addition, a liquid containing the above-mentioned antibacterial metal ions, for example, a copper chloride aqueous solution, a dispersion containing inorganic oxide fine particles such as colloidal silica, and a dispersion containing photocatalyst fine particles such as titanium oxide, is added to the precursor. Mix to form a coating solution for the antimicrobial film.

In addition, the coating liquid can be irradiated with ultraviolet rays in order to activate the photocatalyst fine particles. In this case, for example, ultraviolet rays of 5 to 50 W/m ² can be irradiated for 1 to 24 hours.

Next, a coating liquid is applied to the first surface of the cleaned glass plate 1 . Although the coating method is not particularly limited, for example, a flow coating method, a spray coating method, a spin coating method, or the like can be employed. After that, the applied coating liquid is dried in an oven or the like at a predetermined temperature (eg, 80 to 200 ° C.) to volatilize the alcohol content in the solution, for example, for hydrolysis and decomposition of the organic chain. By sintering at a predetermined temperature (for example, 200 to 500° C.), the antibacterial film 2 can be obtained.

<3. Optical Properties of Glass Member>
As for the optical properties of the glass member 10, for example, the visible light transmittance is preferably 80% or more, more preferably 85% or more. Further, the haze ratio of the glass member 10 is, for example, 20% or less, further 15% or less, particularly 10% or less, and in some cases 0.1 to 8.0%, further 0.1 to 6.0%. may

<4. Features>
(1) In the glass member 10 according to the present embodiment, the antibacterial film 2 includes an inorganic oxide forming a three-dimensional network bond and an antibacterial metal ion held in the inorganic oxide. The oxide acts as a binder that holds the metal ions. Therefore, elution of metal ions can be suppressed.

(2) When the antibacterial film 2 contains a plurality of kinds of inorganic oxide fine particles with different average particle sizes, the gaps between the inorganic oxide fine particles with a large average particle size are filled with the inorganic oxide fine particles with a small average particle size. be able to. That is, when inorganic oxide fine particles with the same average particle size are contained, voids occur between the fine particles even when the particles are packed closely. Voids formed by oxide fine particles can be filled with small inorganic oxide fine particles. As a result, the path length of metal ions can be extended, and the elution of Cu ions can be suppressed. For example, FIG. 2 is a schematic diagram for explaining this, and photocatalyst fine particles are used as fine particles having a small average particle size. Therefore, the elution of antibacterial metal ions in the antibacterial film 2 can be further suppressed. When crystalline fine particles are used, it is difficult for metal ions to pass through the crystallites, so that the path length can be made longer. Therefore, from the viewpoint of suppressing elution of metal ions, it is preferable to use crystalline particles.

(3) When the antibacterial film 2 is irradiated with light such as ultraviolet rays, the photocatalyst fine particles are activated, and the antibacterial metal ions are reduced and deposited on the surface of the photocatalyst fine particles. This further suppresses the elution of metal ions. Such an effect can be obtained not only when the antibacterial film 2 of the finished product is irradiated with light, but also when the coating solution for the antibacterial film 2 is irradiated with light as described above. Moreover, since the photocatalyst fine particles and the metal ions or ion complexes are electrostatically bound, the elution of the metal ions is further suppressed. Furthermore, since the photocatalytic fine particles have an antibacterial effect, in addition to the antibacterial metal ions, the antibacterial performance can be further improved.

(4) When photocatalyst fine particles having a smaller average particle size than inorganic oxide fine particles having a large average particle size are included, the photocatalyst fine particles are bound around the inorganic oxide fine particles having a large average particle size, so that the photocatalyst fine particles are laminated. It is possible to increase the surface area of the region where the Therefore, the effect of the photocatalyst is more likely to manifest.

(5) If the maximum diameter of the inorganic oxide fine particles having a large average particle diameter is larger than the film thickness of the antibacterial film 2, unevenness is formed on the surface and the apparent refractive index can be reduced. As a result, transmittance can be improved.

<5. Variation>
Although one embodiment of the present invention has been described above, the present invention is not limited to this, and various modifications are possible without departing from the gist of the present invention. Note that the following modified examples can be combined as appropriate.

Although the inorganic oxide fine particles are contained in the antibacterial film in the above embodiment, the inorganic oxide fine particles are not necessarily required, and may be added as necessary.

Examples of the present invention will be described below. However, the present invention is not limited to the following examples.
(1) Preparation of Examples A float glass plate having a size of 50 mm x 50 mm and a thickness of 1.1 mm was prepared, and its surface was subjected to alkaline ultrasonic cleaning. Next, a coating liquid for an antibacterial film having the composition shown below was prepared. The concentration of solids in the coating liquid was 4%. Further, Table 2 shows the details of Concentrate in Table 1. All units are g.

なお、表１中のＳＴＳ－０１は、石原産業株式会社のＴｉＯ₂微粒子分散液であり、表２中のＰＬ―７は、扶桑化学工業株式会社のＳｉＯ₂微粒子分散液である。

STS-01 in Table 1 is a TiO ₂ fine particle dispersion available from Ishihara Sangyo Co., Ltd. PL-7 in Table 2 is a SiO ₂ fine particle dispersion available from Fuso Chemical Industries.

In Example 4 above, the coating liquid was irradiated with ultraviolet rays of 10 W/m ² for 24 hours. Subsequently, the coating liquids of Examples 1 to 5 were applied to the surface of the glass plate by spin coating, and then heated in an oven at 300° C. for 30 minutes. Thus, glass members according to Examples 1 to 5 were obtained. The film thickness of the antibacterial film in each example was about 100 nm.

The composition of the antibacterial film on the completed glass member is as follows. The unit is % by mass.

(2) Evaluation The glass members of Examples 1 to 5 were subjected to the following tests.

(2-1) Elution test The glass members according to Examples 1 to 5 were immersed in 25 ml of purified water at 25°C, and after 24 hours the relationship between the copper elution rates was calculated. The elution rate was calculated as follows. First, the sample water was colored with PACKTEST COPPER (manufactured by Kyoritsu Rikagaku Kenkyusho) and measured with Digital PACKTEST COPPER (same as above) to determine the concentration of copper ions contained in the liquid. It was converted into a weight ratio with respect to the contained copper.

FIG. 3 is a graph showing changes over time in the elution rate of copper ions in Examples 1-3. According to FIG. 3, the elution rates of Examples 1 and 3, which contain photocatalyst fine particles, are suppressed compared to Example 2, which does not contain photocatalyst fine particles. In particular, after 20 hours, the difference in dissolution rate becomes large. It is considered that this is because titanium oxide fine particles having a small average particle size fill the gaps between the silica fine particles, thereby suppressing the elution of copper ions. In particular, when Examples 1 and 3 are compared, the elution rate of copper ions is suppressed in Example 1, which has a higher content of titanium oxide fine particles. However, even in Example 2, the elution rate of copper ions is suppressed until 10 hours have passed.

FIG. 4 is a graph showing changes over time in the elution rate of copper ions in Examples 4 and 5. FIG. According to FIG. 4, the elution rate of copper ions is suppressed in Example 4 in which the coating liquid was irradiated with ultraviolet rays. It is considered that this is because copper ions were reduced by irradiation with ultraviolet rays and deposited on the surface of the titanium oxide fine particles.

FIG. 5 is a SEM image of the surface and cross section of the antibacterial film of Example 1. FIG. As shown in this photograph, silica fine particles with a large average particle size are dispersed on the surface of the antibacterial film, and titanium oxide fine particles with a small average particle size are stacked in the gaps between them. It is considered that the elution of copper ions is suppressed by such a laminated structure. The present inventor has confirmed that such a laminated structure is the same in Examples 3 to 5 as well.

(2-2) Antibacterial test Antibacterial properties were evaluated as follows based on JIS R1702:2020 (film adhesion method).
- Test bacteria: E. coli (Escherichia coli NBRC3972)
・Sample form: above glass member ・Action time: 8 hours ・UV irradiation (wavelength: 360 nm): 0.25 mW/cm ²
・ Calculation of antibacterial activity value (R): R = (Ut-U0) - (At-U0) = Ut-At
U0: Average value of the logarithmic value of the viable count immediately after inoculation of the glass plate Ut: Average value of the logarithmic value of the viable count of the glass plate after 8 hours At: Logarithm of the viable count of the glass member after 8 hours Average value and operating conditions: temperature 35 ° C, humidity 90% or more (JIS compliant)
・ Adhesive film: 40 mm x 40 mm PP film (JIS standard)
・Ingestion of test bacteria solution: 0.2 ml
・Number of viable bacteria in test bacterial solution: 1.1 × 10 ⁶
・Measurement of the number of viable bacteria: Measure the number of viable bacteria on the glass plate immediately after inoculation of the glass plate and after culturing for 24 hours.

As a result of the above test, the antibacterial activities of the glass members according to Examples 1 and 3 to 5 were all 3.5 or higher. In addition, the antibacterial activity of Example 2, which does not contain titanium oxide fine particles, was 2.5 or higher. If it is 2.0 or more, it is evaluated that there is antibacterial activity, so it was confirmed that the glass members according to Examples 1 to 5 had sufficient antibacterial performance.

1 glass plate 2 antibacterial film 10 glass member 100 article

Claims (11)

a glass plate having a first side and a second side;
an antibacterial film formed on the first surface;
with
The antibacterial membrane is
a binder containing a metal oxide that forms a three-dimensional network bond;
an antibacterial metal ion;
A glass member containing The glass member according to claim 1, wherein the antibacterial film contains 1% by mass or more of the antibacterial ion. 3. The glass member according to claim 1, wherein said antibacterial film contains at least one kind of fine particles. 4. The glass member according to claim 3, wherein the antibacterial film contains 60% by mass or more of the fine particles. 5. The glass member according to claim 3, wherein said antibacterial film contains a plurality of types of said fine particles. 6. The glass member according to claim 5, wherein said plurality of types of fine particles have different average particle sizes. 7. The glass member according to claim 6, wherein, among the plurality of kinds of fine particles, the fine particles having the largest average particle diameter have a maximum diameter larger than the film thickness of the antibacterial film. 8. The glass member according to any one of claims 1 to 7, wherein said antimicrobial ions are monovalent or divalent copper ions. The glass member according to any one of claims 1 to 8, wherein the antibacterial film contains a plurality of types of fine particles, and one of the plurality of types of fine particles is a photocatalyst fine particle. The glass member according to claim 9, wherein the photocatalyst fine particles are made of _TiO2 . forming a coating liquid by adding photocatalyst fine particles and antibacterial metal ions to silicon alkoxide;
a step of irradiating the coating liquid with ultraviolet light;
applying the coating liquid to a glass plate;
heating the glass plate coated with the coating liquid;
A method for manufacturing a glass member, comprising:

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