JP2007302527A - Glass workpiece with photocatalytic film and constructed structure using glass workpiece with photocatalytic film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide glass with a laminated film including a photocatalytic film which prevents the pollution of the surface of a base material such as the glass caused by low molecular siloxane or the like isolated from a silicone-based sealing material for a long period and keeps transparency and has a self-running-off-layer free from deterioration of various characteristics such as the hydrophilicity of the photocatalytic film and a method of manufacturing the same. <P>SOLUTION: In the glass workpiece with the photocatalytic film using the base material with the photocatalytic film as the glass with the photocatalytic film comprising glass with the photocatalytic film and the sealing material, the methylene blue decomposition property of the photocatalytic film is ≥0.08 (Abs) and the quantity of the low molecular siloxane eluted from the sealing material is <100 ppm. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a glass construction body with a photocatalyst film and a construction structure using the glass construction body with a photocatalyst film.

In recent years, contamination of the glass construction body surface by low-molecular siloxane released from a silicone-based sealing material used as a sealing material around the building material has become a problem. This contamination is caused by the release of unreacted low-molecular-weight siloxane present in the silicone sealant and diffusion on the glass construction body via air or rainwater, making the surface of the glass construction body water-repellent and hydrophobic contamination. It is thought that it is caused by the fact that a substance easily adheres (for example, see Non-Patent Document 1). In particular, since the glass construction body is often transparent, it not only impairs the aesthetic appearance, but also has a problem that transparency deteriorates due to this contamination and visibility deteriorates.

  On the other hand, a method of forming a photocatalyst film on a glass construction body is known as a method for decomposing dirt adhering to the surface of the glass construction body and restoring the original transparency of the glass construction body. When the photocatalyst is photoexcited, organic stains and the like attached to the surface of the photocatalyst film are decomposed by the action of the photocatalyst, and as a result, the transparency of the glass construction body surface is restored. At present, in addition to transparency, various photocatalytic films have been proposed for the purpose of imparting functions such as hydrophilicity, antifouling property, antifogging property, and flowability. For example, an invention is disclosed in which a hydrophobic material from a sealing material is decomposed or modified with a photocatalyst by coating a photocatalytic film at least in the vicinity of a silicone sealing material (see, for example, Patent Document 1 or 2). However, these photocatalyst films have a problem that the contaminants of hydrophobic contaminants cannot be sufficiently removed.

  There has also been proposed a cleaning agent that restores the surface of the photocatalyst film once changed to water repellency to hydrophilicity (see, for example, Patent Document 3). However, frequent cleaning has a problem that it is very troublesome in practice.

  In addition, by controlling the amount of flowing-off with a sustained-release substance, it is possible to prevent the adhesion of dirt without trouble, and when the dirt adheres, it is also proposed to reproduce the hydrophilic surface repeatedly by removing it quickly. (For example, refer to Patent Document 4). However, in this method, since the sustained-release substance is organic (in the examples, polyether is used as the sustained-release substance), the sustained-release substance is photodegraded on the photocatalyst film by the action of the photocatalyst film. There is a problem in that it disappears and the effect cannot be fully exhibited.

  In addition, a photocatalyst coating layer having a porous structure with fine pores is formed, and a structure that lowers the contact angle with water and a coating film structure that contains a filler and has permeability in the film thickness direction make it possible to contaminate the silicone eluate. An effective exterior material has also been proposed (see, for example, Patent Document 5). However, this method increases the allowable amount for the silicone eluate, but it is difficult to maintain the same cleanliness as the initial state over a long period of time for the eluate that continues to elute over time. Moreover, since a silicone-based coating is used in a high ratio for the coating film, there is a drawback that it has a strong affinity with the eluate of the silicone sealing material and is easily selectively adsorbed on the membrane surface.

JP-A-8-302856 JP 2001-55799 A JP 2001-64683 A JP 2000-265163 A JP 2004-225449 A Satoshi Okamoto, Yuji Shinobu “Architecture Technology” August 1997 p152-160

The present invention prevents the above-mentioned drawbacks of the prior art, in particular, contamination of the surface of the glass construction body due to low molecular siloxane released from the silicone-based sealing material for a long period of time, maintains transparency, and improves the hydrophilicity of the photocatalytic film. It aims at providing the glass construction body with a photocatalyst film and various construction structures in which various characteristics do not deteriorate.

  The glass construction body with a photocatalyst film in the present invention is characterized by comprising a sealing material with low elution of low molecular siloxane and a glass with a photocatalyst film having high photocatalytic activity.

As glass construction body with photocatalyst film,
(A) The photocatalytic activity of the glass with a photocatalyst film is 0 as the amount of decrease in absorbance after 3 hours of irradiation with ultraviolet light having an ultraviolet irradiation intensity of 1.7 mW / cm ² using a black light blue lamp having a maximum wavelength of 352 nm in the evaluation of methylene blue decomposability. 0.08 (Abs) or more.

As a silicone sealant used for this,
(B) When the cured sealing material is immersed in acetone under the conditions shown in (b-1) below, the elution weight of acetone in the low molecular weight siloxane shown in (b-2) below is It is characterized by being a low-contamination sealant that is 100 ppm or less with respect to the weight of the sealant.
(B-1) The cured sealing material is immersed in acetone in a completely sealed container for 24 hours ± 1 hour in an environment of 23 ± 2 ° C., and then the sealing material is taken out.
(B-2) Schematic formula: C ₁₂ H ₃₆ O ₆ Si ₆ , compound name: Dodecamethylcyclohexasiloxane, molecular weight: 445, CAS number: 540-97-6
The abrasion resistance of the photocatalyst film of the glass with a photocatalyst film is a Δhaze value after 100 times of wear in a Taber abrasion test (using a CS-10F worn wheel, load 4.9 N) based on JIS R3221 (2002) 6.4. 4% or less.

  The photocatalytic film is characterized by being a film having a water contact angle of not less than 1 week and not more than 20 ° as a hydrophilic property in a dark place.

The average surface roughness Ra value of the photocatalytic film is preferably 1 nm or more and 20 nm or less.
The photocatalytic film includes a substance that expresses a photocatalyst and SiO ₂ , and the Si ratio in the total metal composition contained in the film is Si / the molar ratio of all metal atoms in the film is 0.80 or less. .
The photocatalyst fine particle ratio in the total metal composition contained in the photocatalyst film is a molar ratio of photocatalyst fine particles / all metal atoms in the film, which is 0.1 or more and 0.9 or less.

  The construction structure of the present invention is obtained from the glass construction body with a photocatalyst film of the present invention.

  By using the glass with a photocatalyst film of the present invention and a silicone-based sealing material, it is possible to prevent contamination of the surface of the glass construction body by low-molecular siloxane and the like released from the sealing material, high transparency and excellent antifouling properties, degradability, hydrophilicity The construction structure using the glass construction body with a photocatalyst film and the glass construction body with a photocatalyst film which can maintain the property and antifogging property for a long period of time can be obtained.

  In the present invention, methylene blue degradability evaluation is used as the photocatalytic activity evaluation of the photocatalytic film. As a silicone-based sealing material used for bonding purposes when the absorbance of the aqueous solution of methylene blue after irradiating ultraviolet light onto glass with a photocatalyst film in contact with methylene blue is 0.08 (Abs) or more and used as a construction structure Glass construction body with photocatalyst film that can prevent contamination on the surface of glass construction body by using low-contamination sealing material and can maintain high transparency and excellent antifouling, degradability, hydrophilicity, and antifogging properties for a long time And the construction structure using the glass construction body with a photocatalyst film can be obtained.

  Moreover, the glass construction body with a photocatalyst film of the present invention can rapidly decompose and remove a small amount of contaminants due to its high photocatalytic activity.

  Furthermore, due to the high hydrophilicity, it is possible to suppress the retention of hydrophobic contaminants on the photocatalyst film and to make it difficult to adsorb the contaminants on the film surface. Moreover, an effect can be continued, so that the duration of hydrophilicity expressed as darkness hydrophilic persistence is long. In particular, when the average surface roughness Ra of the photocatalyst film is large, the surface area becomes large, so that the hydrophilicity is easily improved as compared with the smooth film having the same composition, and the effect of making it difficult to approach hydrophobic contaminants is enhanced. Moreover, since the surface area becomes still larger when the surface has porosity, it is preferable. Some pollutants may be adsorbed on the surface of the photocatalyst film or in some cases, but in this case, the amount of adsorption is small, so the photocatalytic activity of the photocatalyst causes the pollutant to adhere to the photocatalyst film. It can be prevented from being decomposed and removed before fixing and remaining on the surface of the photocatalyst film, and various characteristics of the original photocatalyst film can be maintained.

  In addition, the glass construction body with a photocatalyst film of the present invention has practical wear resistance, and it is suppressed that the film is scratched or peeled off during normal handling or cleaning. Can be used without change.

  By including Si in the film composition of the photocatalyst film, the wear resistance of the film can be expressed even in the low temperature treatment process. Moreover, since hydrophilic retention property increases, it is effective in the expression of hydrophilicity and photocatalytic activity, and as a result, it is effective in suppressing sealant contamination.

  Moreover, the glass construction body with a photocatalyst film in the present invention means all glass construction bodies used where there is a possibility of being polluted by pollutants, and can significantly improve the contamination resistance. Excellent economy. In particular, the transparency of the glass construction body can be maintained for a long time, and the visibility is excellent. Moreover, the frequency | count of the cleaning operation | work of the glass construction body surface can be reduced or eliminated, and it becomes possible to save work and to reduce cleaning expenses.

  The glass construction body with a photocatalyst film of the present invention is excellent in hydrophilicity, soil decomposability and antifogging properties over a long period of time. That is, by preventing contamination by contaminants, water droplets adhering to the surface of the photocatalyst film are wetted and spread, the action of decomposing the photocatalyst film is not deteriorated, and the surface is not fogged and excellent in antifogging properties. Moreover, when the light such as sunlight is irradiated, the soil decomposability (especially, the decomposition of organic matter) is maintained, and further, when water flows down the surface of the glass construction body with the photocatalyst film of the present invention due to rain or the like. In addition, the inorganic dirt is also washed away, and the self-cleaning effect is maintained.

Contaminants from the sealing material are generated immediately after the sealing material is applied, and are considered to continue to occur over the long term. When only the photocatalyst film is formed to solve the contamination by the pollutant (see, for example, Patent Document 1 or 2), the pollutant gradually diffuses to the surface of the photocatalyst film, and the pollutant is bound or adsorbed to the photocatalyst film. By doing so, the film surface changes to water repellency. As a result, substances that are mainly composed of hydrophobic substances in the air are likely to adhere to the film surface, resulting in surface contamination, not only deteriorating the appearance, but also maintaining the characteristics of the original photocatalytic film. I found out. Moreover, although the surface contamination is slightly reduced by forming the photocatalytic film as compared with the case where the film is not formed, it is insufficient to prevent the contamination due to the contaminant.

  When applying the glass construction body with a photocatalyst film to a construction structure for a window glass and an outer wall, the present inventors set the photocatalytic activity of the photocatalyst film to 0.08 (Abs) or more, and By using a low-fouling sealing material with a low-molecular-weight siloxane eluted in a specific organic solvent of 100 ppm or less for fixing, it is possible to prevent contamination of the surface of a glass construction body with a photocatalyst film for a long period of time and transparency It was found that a construction structure that can maintain the various characteristics of the original photocatalytic film can be obtained.

Examples of the low-contamination sealant include a silicone sealant in which the weight of elution of low-molecular siloxane into a specific organic solvent is 100 ppm or less with respect to the weight of the sealant before immersion in the organic solvent. In the present invention, acetone is used as a specific organic solvent, and low molecular siloxane is easily available for quantitative evaluation because it can be stably obtained as a reagent, and reflects the tendency of the total elution amount of low molecular siloxane. The following cyclic siloxane considered to be present was used for quantitative evaluation.
Chemical formula: C ₁₂ H ₃₆ O ₆ Si ₆ , compound name: Dodecamethylcyclohexasiloxane, molecular weight: 445, CAS number: 540-97-6.

  By using a low-contamination sealant, the diffusion of low-molecular siloxanes caused by the sealant is suppressed, and as a result, the hydrophobic dirt that has been induced is less likely to adhere. It can be removed, or it can be removed by rainfall or washing, and contamination by pollutants can be prevented for a long time.

  In the present invention, the photocatalyst generates conduction electrons and holes by excitation of electrons in the valence band when irradiated with light having an energy larger than the energy difference between the valence band and the conduction electron band of the photocatalyst. A material having such properties may be used, and may be not only an ultraviolet-responsive photocatalyst but also a visible-light-responsive photocatalyst. Preferred examples of such a photocatalyst include anatase type titanium oxide, rutile type titanium oxide, tin oxide, zinc oxide, tungsten trioxide, ferric oxide, strontium titanate, bismuth oxide, iron oxide and the like. Titanium oxide is particularly preferable.

Hereinafter, the present invention will be described in detail.
The photocatalyst film used in the present invention has a photocatalytic activity of 0.08 (Abs) or more in methylene blue degradability evaluation. Further, long-term contamination can be prevented by using a sealing material having a low molecular weight siloxane eluted in a specific organic solvent of 100 ppm or less in combination with a photocatalytic film having a photocatalytic activity of 0.08 (Abs) or more. The photocatalytic activity of the photocatalytic film used in the present invention is more preferably 0.10 (Abs) or more.

  The methylene blue degradability in the present invention was defined as follows. A detailed evaluation method will be described later in Example [photocatalytic activity].

  One glass sample with a 10 cm square photocatalyst film that had been initialized (the initialization method will be described later) was prepared, and silicon grease was applied to the cylindrical test cell and pressed against the surface of the sample film. An aqueous methylene blue solution for adsorption was poured into the cell, covered with a cover glass, and allowed to stand in the dark, and the photocatalyst film was sufficiently adsorbed with methylene blue. The aqueous solution in the cell was discarded, and a test methylene blue aqueous solution was newly injected. After thoroughly injecting the injected methylene blue test solution with a pipette, 1.0 millilimit was accurately collected in a spectrophotometer measurement cell (initial solution). Cover the cover glass, irradiate the cover glass with UV light for 3 hours, and then thoroughly stir the methylene blue test solution after 3 hours with a pipette, and then accurately measure 1.0 milimit with a spectrophotometer measurement cell. (Decomposition solution). The absorbance (Abs) at a wavelength of 664 nm of the collected initial solution and decomposition solution was measured, and the value (Abs) obtained by subtracting the absorbance of the initial solution from the absorbance of the decomposition solution was defined as photocatalytic activity.

  When the photocatalytic activity of the photocatalyst film used in the present invention is less than 0.08 (Abs), it is difficult to decompose and remove even a trace amount of contaminants diffused on the film surface. It cannot be prevented and contamination progresses. In addition, even when the photocatalytic activity is 0.08 (Abs) or more, when a silicone sealing material usually used for architectural applications is used, the amount of low-molecular siloxane eluted from the sealing material is large, and the photocatalytic film can be decomposed. As a result, the contamination progresses.

  On the other hand, although a sealing material having a low molecular weight siloxane elution amount of 100 ppm or less has been known for some time, this is a soda-lime glass usually used for architectural applications, and a photocatalytic film having a photocatalytic activity of less than 0.08 (Abs). When applied to a glass construction with glass, the effect of suppressing contamination is not seen for a long time, and after half a year to one year, the degree of contamination of the glass construction is the same as when using a normal sealing material. It was.

  The amount of low molecular siloxane eluted from the sealing material in the present invention was defined as follows. A detailed quantification method will be described later in Example [Method for quantification of low-molecular siloxane eluted from sealing material].

A sealant cured for 7 days in an environment of temperature 23 ° C ± 2 ° C and humidity 50% RH ± 5% is immersed in acetone in a completely sealed container for 24 hours ± 1 hour in an environment of temperature 23 ± 2 ° C. Only the sealing material was taken out of the container. Quantify the low molecular weight siloxane in the remaining acetone by gas chromatography,
[Total weight of eluted low-molecular siloxane (= weight of low-molecular siloxane in all acetone solution used for elution)] in [Dry weight of sealant before dipping in acetone] was expressed in concentration (ppm).

  The present inventors have provided a photocatalytic film having a photocatalytic activity of 0.08 (Abs) or more and a sealing material having a low molecular siloxane elution amount of 100 ppm or less, specifically, a low molecular siloxane content or an elution amount. It has been found that long-term contamination can be avoided by using a silicone sealing material having a reduced size.

  Here, examples of the sealant evaluation method include a method of applying a sealant material to the substrate glass and exposing it. The sealant to be applied can be changed according to the test, but in order to achieve the object of the present invention, a low-molecular-weight siloxane is less volatilized and eluted. Silicone sealing materials that are expected to be used in cleanrooms related to semiconductors are known as those that cause low volatilization and elution of low molecular siloxanes. For example, pure sealant, pure sealant S (all manufactured by Shin-Etsu Silicone), SE5088, SE9184, SE9185 (all manufactured by Toray Dow Corning), Tosseal 80-SC (manufactured by GE Toshiba Silicone), TB3961B (manufactured by Yokohama Three Bond Co., Ltd.) ), Penguin Clean Seal 2555 (manufactured by Sunstar Giken Co., Ltd.) and the like, but are not limited thereto. It was confirmed that the sealing material had a low molecular weight siloxane volatilization and a small amount of elution.

  The photocatalyst film in the present invention is also characterized in that the wear resistance is at a practical level. Some known photocatalyst films have been made thicker or have a porous structure in order to improve photocatalytic activity and hydrophilicity, and these films may have poor wear resistance. On the other hand, the film in the present invention has a Δhaze after the Taber abrasion test of 4% or less and has practical wear resistance.

  The photocatalytic film in the present invention has a hydrophilic property in the dark (hydrophilic property in the dark) of 1 week or more, more preferably 2 weeks or more, more preferably 1 month or more, and a water contact angle of 20 ° or less, preferably Is a film that maintains 10 ° or less, more preferably 5 ° or less.

  The darkness persistence in the present invention was defined as follows. The detailed evaluation method is described in Example [Hydrophilicity in dark place].

The glass construction body with the photocatalyst film that has been initialized is left in a dark place in an ordinary indoor environment (ultraviolet irradiation intensity of 0.01 mW / cm ² or less, temperature 23 ° C. ± 2 ° C., humidity 50 ± 5% RH) for a certain period of time. The water contact angle was measured after time.

  When used outdoors, it is assumed that low-molecular-weight siloxanes are likely to elute from the sealing material in cloudy and rainy weather. High hydrophobicity makes it difficult to approach hydrophobic pollutants and improves anti-contamination properties.

  The photocatalytic film of the present invention has an average surface roughness Ra value of 1 nm to 20 nm, more preferably 2 nm to 10 nm. When Ra was less than 1 nm, the surface area of the photocatalyst film was likely to be small, and sufficient photocatalytic activity could not be expressed. Further, when Ra exceeds 20 nm, the surface roughness is too large, and there is a problem that the transparency and wear resistance of the film cannot be ensured.

In the present invention, the Si ratio in the total metal composition contained in the photocatalytic film is 0.80 or less in terms of the molar ratio of Si / all metal atoms in the film. Here, the metal means all elements other than transition metals, typical metals, and non-metals including metalloids such as Si, P, Ge, and Sn. When Si / all metals exceeds 0.80 (mol ratio), the Si ratio is too high, and the film is easily contaminated. The cause of this is not clear, but it is probably because a film containing a large amount of Si becomes a film having a high affinity with low molecular siloxane. The calculation method here is the same as the number of moles of Si in SiO ₂ and TiO ₂ when the film material is SiO ₂ and TiO ₂ as an example.

  The glass construction body with a photocatalyst film comprised of the glass with a photocatalyst film and a sealing material used therefor in the present invention is suitable as a construction structure used for an outer wall application. The shape of the glass construction body is not limited to a flat plate, and may have a curvature on the entire surface or a part thereof. Furthermore, when a glass construction body is a transparent glass construction body, since the photocatalyst film | membrane is transparent, it is excellent at the point which visibility does not deteriorate. From the viewpoint of visibility, it is preferable that the visible light transmittance (JIS R3106 (1998)) of the glass construction body with a photocatalyst film having a photocatalyst film is 70% or more.

  The photocatalytic film in the present invention can be formed by a wet method such as a sol-gel method, a dry method such as a CVD method, and the production method is not particularly limited. When the photocatalyst film is formed by a wet method, the photocatalyst film can be formed by applying a photocatalyst film-forming composition containing photocatalyst fine particles and a medium to the glass construction body. Therefore, the surface roughness Ra is preferably easily controlled.

Even when the photocatalyst film is formed at low temperature by using titanium oxide fine particles as the photocatalyst fine particles, a film made of titanium oxide can be formed. The titanium oxide film may be a composite film with a metal other than titanium oxide or a metal oxide. In particular, a composite film with silica (SiO ₂ ) is preferable in that high hydrophilicity can be maintained for a long time and photocatalytic activity can be exhibited. However, as described above, if the silica (SiO ₂ ) ratio is too high, the affinity with the low-molecular siloxane that is a pollutant is increased, so that it is easily contaminated in the long term.

The metal or metal oxide constituting the photocatalytic film of the present invention does not need to be a complete metal or metal oxide, and may contain a precursor or amorphous. Moreover, the organic group derived from the raw material which forms a film | membrane, and the part which is not oxidized may remain | survive. For example, when the metal oxide is silica (SiO ₂ ), silanol groups or the like may partially remain, and silica (SiO ₂ ) is formed as the dehydration condensation reaction proceeds.

  In the photocatalyst film in the present invention, when the photocatalyst fine particles are contained, the metal ratio in the photocatalyst fine particles is 0.1 to 0.9, more preferably 0.3 to 0.7 in terms of mole ratio in the total metal composition. It is preferably included.

  When the photocatalyst fine particles in the present invention are used in the composition for forming a photocatalyst film, the average particle size (hereinafter simply referred to as particle size) of the aggregated particles is preferably 5 to 100 nm. The average particle size in the composition can be measured by using a Microtrac UPA particle size distribution meter (manufactured by Nikkiso Co., Ltd.), using light scattering to measure the aggregate particle size of fine particles in the liquid.

  If the particle diameter is too small, the photocatalyst fine particles are buried in the formed photocatalyst film, so that various effects of the photocatalyst are hardly exhibited. On the other hand, if the particle size is too large, the formed photocatalytic film has insufficient mechanical strength, and transparency may not be ensured.

  Before producing the glass construction body with a photocatalyst film in the present invention, it is preferable to pre-treat the glass construction body. It is advantageous that the pretreatment is cleaning, light irradiation treatment, plasma treatment, corona treatment, UV treatment, discharge treatment such as ozone treatment, chemical treatment such as acid or alkali, physical treatment using an abrasive, etc. It is preferable in that it can remove dirt.

  The photocatalytic film in the present invention may contain a composition comprising a substance having a function other than the photocatalytic property. Preferred examples include coloring dyes, pigments, ultraviolet absorbers, antioxidants, oxide fine particles other than photocatalyst fine particles (phosphorus pentoxide, magnesium oxide, etc., preferably having an average particle size of 200 nm or less).

  The photocatalyst film in this invention can apply | coat the composition for photocatalyst film formation to the surface of a glass construction body, for example using a wet method, and can form a glass construction body with a photocatalyst film. Preferable examples of the wet method include spray coating, brush coating, hand coating, spin coating, dip coating, coating by various printing methods, curtain flow, die coating, flow coating, and the like.

  In particular, a glass construction body with a photocatalyst film formed by a spray coating method is suitable in terms of economics and simplicity of production and stability of physical properties of a coating film.

  The photocatalyst film in the present invention may be subjected to a post-treatment for the purpose of removing the medium or increasing the hardness of the photocatalyst film after applying the photocatalyst film forming composition. Examples of the post-treatment include drying and heating at room temperature, irradiation with electromagnetic waves such as ultraviolet rays and electron beams. In consideration of the heat resistance, workability, and mass productivity of the glass construction body, heating is preferably performed in the air at 50 to 700 ° C., particularly 80 to 300 ° C. for 1 to 60 minutes. In particular, it is preferable to perform irradiation with electromagnetic waves such as ultraviolet rays and electron beams as post-processing because the mass production process is shortened.

  In the present invention, the thickness of the photocatalyst film is preferably 1 to 300 nm, and particularly preferably 5 to 100 nm in consideration of economy. If the thickness is less than 1 nm, the desired photocatalytic performance may not be exhibited. If the thickness exceeds 300 nm, the photocatalyst film may be cracked, interference fringes may be formed, or scratches may be noticeable. The thickness of the resulting photocatalyst film can be controlled by adjusting the concentration of the composition for forming the photocatalyst film, the type of solvent, the coating conditions, the post-treatment conditions, and the like.

  The film structure of the photocatalyst film in the present invention may be a single photocatalyst film or a laminated film including a photocatalyst film or a film other than the photocatalyst. For example, an alkali barrier film such as a silica film may be provided between the glass substrate and the photocatalyst film, or a film such as a silica film may be formed on the photocatalyst film.

  In addition to Ti, the photocatalytic film of the present invention may contain one or more metals selected from the group consisting of Al, Si, Zr, and Sn, and metal oxides. The inclusion of these in the photocatalyst film is preferable because the isoelectric point of the film changes and the adsorptivity of charged contaminants can be controlled.

  In the photocatalyst film used for the glass construction body with a photocatalyst film in the present invention, a resin such as a hydrophilic resin or a water absorbent resin may be contained in terms of improving water absorption (propensity to make moisture difficult to repel). Examples of the resin include polyacrylic acid resin, polyvinyl alcohol resin, polybutyral resin, polyurethane resin, cellulose and derivatives thereof.

  The glass construction body with a photocatalyst film of the present invention is developed for various applications in which a glass with a photocatalyst film is attached to a window frame, a casing, or other construction structure with a silicone-based sealing material, for example, on an outer wall, a glass window, an inner wall, a ceiling, it can.

  Examples (base materials: a, b, c, e and sealing materials: B, E, G to J used), comparative examples (base materials: d, f, or sealing materials: A, C, D) , F use). The glass construction body with a photocatalyst film (hereinafter, simply referred to as a film-coated substrate) was evaluated using the following method.

[appearance]
The haze value of the film-coated substrate was measured with a direct reading haze computer (manufactured by Suga Test Instruments Co., Ltd.).

[thickness]
After producing the substrate with a film, the film was scraped with a cutter, and the thickness of the photocatalyst film was measured by a stylus method.

[Initial hydrophilicity]
UV irradiation intensity of 2.0 mW / cm ² (UV illuminance meter: Eihiro Seiki Co., Ltd.) with a black light blue lamp having a peak wavelength of 352 nm (FL20S / BL-B 20 type, manufactured by Matsushita Electric) on the surface of the photocatalyst film Irradiate with UV MONITOR MS-211-I, measurement wavelength range: UV-A (315-400 nm, measurement accuracy: within 10%) for 24 hours. This operation is called initialization. After initialization, the water contact angle on the membrane surface is measured with a contact angle meter (Kyowa Interface Science Co., Ltd .: CA-X150), and this measured value is referred to as initial hydrophilicity. The measurement was performed at five different sites, and the average value was adopted. The contact angle is preferably 20 ° or less, more preferably 10 ° or less, from the viewpoint that hydrophilicity can be exhibited.

[Hydrophilic durability in the dark]
After holding the film-coated substrate whose initial hydrophilicity was measured in an indoor dark place where no light was irradiated (ultraviolet irradiation intensity of 0.01 mW / cm ² or less, temperature 23 ° C. ± 2 ° C., humidity 50 ± 5% RH) for one week. The water contact angle was measured with a contact angle meter (Kyowa Interface Science Co., Ltd .: CA-X150). The measurement was performed at five different sites, and the average value was adopted. The contact angle is preferably 20 ° or less, more preferably 10 ° or less from the viewpoint that hydrophilicity can be exhibited for a long period of time.

[Photocatalytic activity]
Evaluation of methylene blue degradability was carried out by the following method.
Operation One glass construction body with a photocatalyst film of 1.10 cm square was prepared and initialized by the method shown in [Initial hydrophilicity].
Work 2. After applying silicon grease (Dow Corning, HIGH VACUUM SILICON GREESE FS) to a cylindrical test cell (manufactured by Marumoto Struers, Multifoam) with a diameter of 40 mm, and pressing the sample membrane surface to fix it, a methylene blue aqueous solution is placed in the cell. (For adsorption: concentration 20 mmol / m ³ ) 34 milimit was injected, the test cell was covered with a cover glass and allowed to stand in a dark place for 12 hours to sufficiently adsorb methylene blue on the photocatalyst film.
Work 3. The above work 2. The aqueous solution was discarded, and 35 methylene blue (for test: concentration 10 mmol / m ³ ) 35 milimit was newly injected into the cell.
Work 4. After thoroughly stirring the methylene blue test solution in the initial state with a pipette, 1.0 millilimit was accurately collected in the spectrophotometer measurement cell (initial solution), and then operation 2. The lid was covered with a cover glass (soda lime glass: thickness 3.0 mm) in the same manner as described above.
Work 5. From the top of the cover glass, ultraviolet rays were irradiated with a black light blue lamp at a UV irradiation intensity of 1.7 mW / cm ² for 3 hours as measured on the back side of the glass construction body with a photocatalyst film.
The methylene blue test solution after 6.3 hours of work was sufficiently agitated with a pipette, and then exactly 1.0 millilimit was collected in a spectrophotometer measurement cell (decomposition solution).
Work 7. Work 4. And work 6. The absorbance (Abs) at a wavelength of 664 nm of the 1.0 methylene blue solution collected in step 1 was measured with a spectrophotometer (H-4100, manufactured by Hitachi, Ltd.).
Work 8 A value (Abs) obtained by subtracting the absorbance of (initial solution) from the absorbance of (decomposed solution) was defined as photocatalytic activity.

[Abrasion resistance]
A taper abrasion test (JIS R3221 (2002) 6.4 wear frequency: 100 times, load: 4.9 N) is applied to the film-coated substrate, and the haze value before and after the abrasion test is measured (measuring device name: Suga test) (Manufactured by Kikai Co., Ltd .: Direct reading haze computer), and the amount of change was determined. A haze change of 4% or less is practically preferable.

[Membrane surface roughness Ra]
The surface roughness of the substrate with a film was measured by AFM (SII Nanotechnology, SPA400 / SPI4000).

[Si / all metals]
Si in the film of the substrate with film / total metal in film (mol ratio) was calculated from the coating solution composition. In addition, when the film-forming method is a wet coating, it has been confirmed that the value of the Si / all metal atom mol ratio in the film matches the value of the Si / all metal atom mol ratio in the coating solution. It is.

[Ti in fine particles / all metals]
Ti in the TiO ₂ fine particles of the substrate with film / total metal in film (mol ratio) was calculated from the coating solution composition. When the film formation method is wet coating, the value of the molar ratio of Ti / total metal atoms in the TiO ₂ fine particles in the film and the value of the molar ratio of Ti / total metal atoms in the TiO ₂ fine particles in the coating solution. Has been confirmed to match.

(Preparation of pretreated glass substrate <1>)
A soda-lime glass substrate (100 mm × 100 mm, thickness 3.5 mm) is prepared, and the surface of the film forming portion is polished with cerium oxide, washed with distilled water, dried, and pretreated glass substrate <1. >

(Preparation of pretreated glass substrate <2>)
Prepare an alkali-free glass substrate (100 mm × 100 mm, thickness 1.1 mm, # 1737 manufactured by Corning), polish the surface of the film forming part with cerium oxide, wash it with distilled water, dry it, and pre-process A finished glass substrate <2> was obtained.

(Formation of glass substrate a with photocatalyst film)
(Preparation of silica sol (A))
12.5 g of sodium silicate No. 4 (SiO ₂ : 23.35 mass%, Na ₂ O: 6.29 mass%. SiO ₂ / Na ₂ O molar ratio: 3.83) was added to 37.5 g of water. Furthermore, after adding 30 g of strongly acidic cation exchange resin “SK1BH” (trade name, manufactured by Mitsubishi Chemical Corporation) and stirring for 10 minutes at room temperature, the ion exchange resin was separated by filtration, and a desalted sodium silicate solution (silica The sodium ion was 0.12 parts by mass with respect to 100 parts by mass of the acid). 1.0 g of this solution was placed in a weight-weighed alumina crucible, fired in an electric furnace at 200 ° C. for 1 hour, weighed again, and the solid content concentration was measured to find 5.8% by weight. Further, distilled water was added to the desalted silicic acid solution to obtain silica sol (A) (SiO ₂ concentration: 5.0 mass%).

(Preparation of Composition 1)
An aqueous solution “STS-01” (trade name, manufactured by Ishihara Sangyo Co., Ltd., solid content concentration 30 mass%, hereinafter, titania sol (A) and anatase-type titanium oxide fine particles (average particle size: 56 nm) in 65.0 g of methanol 5.0 g and 30.0 g of silica sol (A) are added, and a surfactant “L-77” (trade name, manufactured by Nihon Unicar Co., Ltd.) is added to a total liquid amount of 100 ppm. Thus, composition 1 (solid content concentration: 3.0 mass%) was obtained.

2 ml of the composition 1 is dropped on the surface of the pretreated glass substrate <1>, applied by a spin coating method, baked at 100 ° C. for 10 minutes in an air atmosphere, and glass with a photocatalyst film having a thickness of 80 nm. A substrate a was obtained. Composition, appearance, film thickness, initial hydrophilicity, dark hydrophilicity, photocatalytic activity, abrasion resistance, average surface roughness Ra of film surface, Si ratio in film, and Ti ratio in TiO ₂ fine particles in film Is shown in Table 1.

(Formation of glass substrate b with photocatalyst film)
(Preparation of composition 2)
In 89.7 g of methanol, an aqueous dispersion “A-6” of anatase-type titanium oxide fine particles (average particle size: 20 nm) (trade name, manufactured by Taki Chemical Co., Ltd., 6.0% by mass of TiO ₂ , hereinafter, titania sol (B 6.7 g and TC-100 (trade name, titanium acetylacetonate manufactured by Matsumoto Pharmaceutical Co., Ltd., solid content concentration 16.5% by mass, hereinafter referred to as titania solution (C)) 3.6 g. Further, a nonionic surfactant “Adecatol SO-145” (trade name, manufactured by Asahi Denka Kogyo Co., Ltd.) was added so as to be 100 ppm with respect to the liquid volume, and composition 2 (solid content concentration: 1. 0% by mass) was obtained.

2 ml of composition 2 is dropped on the surface of the pretreated glass substrate <2>, applied by spin coating, then baked at 600 ° C. for 10 minutes in an air atmosphere, and a glass with a photocatalyst film having a thickness of 40 nm. A substrate b was obtained. Composition, appearance, film thickness, initial hydrophilicity, dark hydrophilicity, photocatalytic activity, abrasion resistance, average surface roughness Ra of film surface, Si ratio in film, and Ti ratio in TiO ₂ fine particles in film Is shown in Table 1.

(Formation of glass substrate c with a photocatalytic film)
(Preparation of composition 3)
To 55.0 g of methanol, 3.0 g of titania sol (A) and 42.0 g of silica sol (A) were added, and the surfactant “L-77” (trade name, manufactured by Nihon Unicar) was added to the total liquid amount. It added so that it might be set to 100 ppm, and the composition 3 (solid content concentration: 3.0 mass%) was obtained.

2 ml of the composition 3 is dropped on the surface of the pretreated glass substrate <1>, applied by a spin coating method, baked at 100 ° C. for 10 minutes in an air atmosphere, and glass with a photocatalyst film having a thickness of 80 nm. A substrate c was obtained. Composition, appearance, film thickness, initial hydrophilicity, dark hydrophilicity, photocatalytic activity, abrasion resistance, average surface roughness Ra of film surface, Si ratio in film, and Ti ratio in TiO ₂ fine particles in film Is shown in Table 1.

(Formation of glass substrate d with photocatalyst film)
A commercially available photocatalyst antifouling glass, Sunclean (trade name, manufactured by PPG) was used as a glass substrate d with a photocatalyst film. Composition, appearance, film thickness, initial hydrophilicity, dark hydrophilicity, photocatalytic activity, abrasion resistance, average surface roughness Ra of film surface, Si ratio in film, and Ti ratio in TiO ₂ fine particles in film Is shown in Table 1.

(Formation of glass substrate e with photocatalyst film)
(Preparation of composition 5)
6.7 g of titania sol (B) and 3.6 g of titania liquid (C) were added to 89.7 g of methanol to obtain composition 5 (solid content concentration: 1.0 mass%).
The composition 5 is spray-coated in the atmosphere on a pretreated glass substrate <2> heated to a temperature of 600 ° C. (a set of spray devices: SG2500, manufactured by EM Spraying Co., Ltd.), and a glass with a photocatalyst film having a thickness of 30 nm A substrate e was obtained. Composition, appearance, film thickness, initial hydrophilicity, dark hydrophilicity, photocatalytic activity, abrasion resistance, average surface roughness Ra of film surface, Si ratio in film, and Ti ratio in TiO ₂ fine particles in film Is shown in Table 1.

(Formation of glass substrate f with photocatalyst film)
(Preparation of composition 6)
To 50.0 g of methanol, 2.0 g of titania sol (A) and 48.0 g of silica sol (A) were added, and surfactant “L-77” (trade name, manufactured by Nihon Unicar) was added to the total liquid amount. It added so that it might be set to 100 ppm, and the composition 6 (solid content concentration: 3.0 mass%) was obtained.

2 ml of the composition 6 is dropped on the surface of the pretreated glass substrate <1>, applied by a spin coating method, then baked at 100 ° C. for 10 minutes in an air atmosphere, and a glass with a photocatalyst film having a thickness of 80 nm. A substrate f was obtained. Composition, appearance, film thickness, initial hydrophilicity, dark hydrophilicity, photocatalytic activity, abrasion resistance, average surface roughness Ra of film surface, Si ratio in film, and Ti ratio in TiO ₂ fine particles in film Is shown in Table 1.

[Quantitative determination method for low molecular weight siloxanes eluted from sealing materials]
Quantification of low molecular weight siloxane eluted from the sealing material used for the photocatalytic film was carried out by the following method, and the results are shown in Table 2. The quantified low molecular weight siloxane has the following structure shown in claim 1.
Chemical formula: C ₁₂ H ₃₆ O ₆ Si ₆ , compound name: Dodecamethylcyclohexasiloxane, molecular weight: 445, CAS number: 540-97-6
Work 1. Squeeze the sealant onto the cleaned glass and cure. (7 days, 23 ± 2 ° C, 50 ± 5% RH)
Work 2. Remove the cured sealant from the glass with a cutter and measure the weight. Moreover, this weight is called dry weight.
Operation 3.9cc screw bottle 2. 3. Add the sealant, and add acetone in an amount that allows the sealant to be completely immersed, and seal it for 24 hours ± 1 hour. Immediately remove the sealant, seal it again, and quantify the low molecular weight siloxane in the liquid by gas chromatography. At this time, a solution obtained by dissolving a low-molecular-weight siloxane (Tokyo Chemical Industry Co., Ltd.), a commercially available reagent, in acetone at a known concentration is analyzed by gas chromatography to prepare a calibration curve of concentration versus strength. To do.

(Example 1 to Example 10)
In the center of the glass substrate a with a photocatalyst film, the sealing material shown in Table 2 was applied one by one so that the thickness was 5 ± 2 mm, the length was 10 ± 2 mm, and the width was 40 ± 2 mm, and the temperature was 23 ± 2 ° C. After drying for 2 days (48 hours) in an environment with a humidity of 50 ± 10% RH and creating a glass construction body with a photocatalyst film, it was exposed to the outdoors in the Yokohama area with a 45 ° inclination to the horizontal plane and facing south. Samples were collected when 12 months passed. Place the collected sample horizontally, apply distilled water to the surface of the membrane with canyon spray, determine that the hydrophobic part with water droplets attached is contaminated by the sealing material, and determine the distance between the upper, lower, left and right hydrophobic parts from the edge of the sealing material. It was determined that the longer the length, the greater the contamination with the sealing material.

  The total lengths of the hydrophobic sites were evaluated as ◎ when 10 mm or less, ○ when 10 mm or more and 20 mm or less, Δ when 20 mm or more and 30 mm or less, and × when 30 mm or less. In addition, in objective visual evaluation, generally dirt within 20 mm of the sealant is tolerated. Therefore, in practice, ◎ and ○ are preferable in this order. The exposure results are shown in Table 3.

(Examples 11 to 20)
The photocatalyst film in which the photocatalyst film which apply | coated the sealing material was formed like Example 1-10 except using the glass base material b with a photocatalyst film instead of the glass base material a with a photocatalyst film in Examples 1-10 An attached glass construction body was obtained. Table 3 shows the results of evaluating this glass construction body with a photocatalyst film.

(Examples 21 to 30)
The photocatalyst film in which the photocatalyst film which apply | coated the sealing material was formed like Example 1-10 except using the glass base material c with a photocatalyst film instead of the glass base material a with a photocatalyst film in Examples 1-10 An attached glass construction body was obtained. Table 3 shows the results of evaluating this glass construction body with a photocatalyst film.

(Examples 31-40)
The photocatalyst film in which the photocatalyst film which apply | coated the sealing material was formed like Example 1-10 except using the glass base material d with a photocatalyst film instead of the glass base material a with a photocatalyst film in Examples 1-10 An attached glass construction body was obtained. Table 4 shows the results of evaluating this glass construction body with a photocatalyst film.

(Examples 41-50)
The photocatalyst film in which the photocatalyst film which apply | coated the sealing material was formed like Example 1-10 except using the glass base material e with a photocatalyst film instead of the glass base material a with a photocatalyst film in Examples 1-10 An attached glass construction body was obtained. Table 4 shows the results of evaluating this glass construction body with a photocatalyst film.

(Examples 51 to 60)
The photocatalyst film in which the photocatalyst film which apply | coated the sealing material was formed like Example 1-10 except using the glass base material f with a photocatalyst film instead of the glass base material a with a photocatalyst film in Examples 1-10 An attached glass construction body was obtained. Table 4 shows the results of evaluating this glass construction body with a photocatalyst film.

An article having a substrate with a photocatalyst film of the present invention is particularly excellent in performance of preventing contamination by low molecular siloxanes diffusing from a silicone-based sealing material and the like, and can be developed for various uses including building materials.

Claims (7)

In the glass construction body with a photocatalyst film in which the glass with a photocatalyst film is attached to the construction structure from the silicone sealing material, the photocatalyst film with the photocatalyst film and the silicone sealing material satisfy the following performances: With glass construction body.
(A) The photocatalytic activity of the glass with a photocatalyst film is 0 as the amount of decrease in absorbance after 3 hours of irradiation with ultraviolet light having an ultraviolet irradiation intensity of 1.7 mW / cm ² using a black light blue lamp having a maximum wavelength of 352 nm in the evaluation of methylene blue decomposability. 0.08 (Abs) or more.
(B) When the cured sealing material is immersed in acetone under the conditions shown in (b-1) below, the elution weight of acetone in the low molecular weight siloxane shown in (b-2) below is The low-contamination sealant (b-1), which is 100 ppm or less with respect to the weight of the sealant, is cured with acetone in a completely sealed container for 24 hours ± 1 hour at a temperature of 23 ± 2 degrees. After soaking, the sealing material is taken out.
(B-2) Structural formula C ₁₂ H ₃₆ O ₆ Si ₆ , compound name Dodecamethylcyclohexasiloxane, molecular weight 445, CAS number 540-97-6   Wear resistance of the photocatalyst film is 4% or less in Δ haze value after 100 times of wear in a Taber abrasion test (using CS-10F worn wheel, load 4.9 N) based on JIS R3221 (2002) 6.4 The glass construction object with a photocatalyst film according to claim 1 characterized by things.   The glass construction body with a photocatalyst film according to claim 1 or 2, wherein the photocatalyst film is a film that maintains a water contact angle of not less than 1 week and not more than 20 ° as a hydrophilic property in a dark place.   The glass construction body with a photocatalyst film according to claim 1, wherein the photocatalyst film has an average surface roughness Ra value of 1 nm or more and 20 nm or less. The photocatalyst film contains a substance that expresses a photocatalyst and SiO ₂ , and the Si ratio in the total metal composition contained in the film is 0.80 or less in terms of Si / mol ratio of all metal atoms in the film. The glass construction body with a photocatalyst film in any one of 4.   The ratio of the photocatalyst fine particles in the total metal composition contained in the photocatalyst film is 0.1 or more and 0.9 or less in terms of the molar ratio of metal in the photocatalyst fine particles / all metal atoms in the film. A glass construction body with a photocatalyst film according to claim 1. The construction structure using the glass construction body with a photocatalyst film in any one of Claims 1-6.