JP2005035198A - Film or sheet with photocatalyst for wallpaper - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a film or sheet with a photocatalyst for wallpaper which enables disposition of photocatalyst particles in a high density on the surface of the wallpaper and of which the base is not corroded by the action of the photocatalyst. <P>SOLUTION: The film or sheet 1 with the photocatalyst for the wallpaper is constituted by laminating sequentially a plastic film or sheet layer 2, a primer layer 3 and a photocatalyst thin film layer 4. The film or sheet layer 2 is formed preferably of a film or sheet of which the elastic modulus is 100 MPa or above at 80-130°C and 100 MPa or below at 150-190°C. The elongation in drying can be suppressed, while the fracture of the photocatalyst particle can be reduced, and also a rugged pattern can be formed beautifully. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a film or sheet with a photocatalyst used to form a wallpaper used by being attached to an indoor wall, ceiling, etc., and more specifically, with a photocatalyst that can form a wallpaper with a photocatalyst by being laminated on a wallpaper substrate. It relates to a film or sheet.

  When photocatalyst is irradiated with light, it exhibits photocatalytic activity and exhibits an oxidizing action, and oxidizes and decomposes organic substances, air pollutants, and bacteria, and exhibits an antibacterial action and an air cleaning action. In addition, the surface is made highly hydrophilic based on the photoreaction and exhibits various actions such as deodorization, antifouling, antibacterial, sterilization, harmful substance removal, and antifogging action. For this reason, photocatalytic technology is used in various fields such as building outer walls, hospital inner walls, mirrors, window glass, sanitary ware, kitchen knives, and cutting boards.

  As for wallpaper (including a decorative sheet), a wallpaper impregnated with a photocatalyst is disclosed (see Patent Document 1). If the photocatalyst action is used in the wallpaper, it can be used to prevent odors such as tobacco odor, pet odor, garbage odor, prevention of mold and mites, decomposition and removal of harmful substances such as formaldehyde, decomposition and removal of pathogenic bacteria, air purification, etc. Various effects can be expected.

  However, since the photocatalyst exerts its action only after being irradiated with light, it does not exert its action unless it exists on the surface of the wallpaper. Since the amount of the photocatalyst existing on the wallpaper surface is smaller than the amount, and the density of the photocatalyst particles on the wallpaper surface is lowered, there is a problem that the obtained photocatalytic action is not sufficient as compared with the amount of the photocatalyst used.

Therefore, for example, in the invention described in Patent Document 2 (Japanese Patent Application Laid-Open No. 10-235802), a photocatalytic titanium oxide powder in which zinc and silicon oxides are supported on a photocatalytic titanium oxide base particle is added to a binder to form a surface of the base sheet. Disclosing a coated decorative sheet;
In the invention described in Patent Document 3 (Japanese Patent Laid-Open No. 2001-341217), a film made of a thermoplastic resin kneaded with photocatalyst fine particles is bonded to a substrate, and the film surface is melted by heating, and a part of the photocatalyst fine particles. Disclosing wallpaper that is exposed on the film surface,
In the invention described in Patent Document 4 (Japanese Patent Application Laid-Open No. 2002-177785), an adhesive is applied to the surface of the wallpaper, and the photocatalyst particles are sprayed on the coating film before it is completely cured. Disclosed is a wallpaper having a titanium oxide-containing film in which particles are fixed by curing the adhesive by drying and visible light reactive titanium oxide particles are exposed from the film.
JP2001-254069A JP-A-10-235802 JP 2001-341217 A JP 2002-177785 A

  In the present invention, the photocatalyst particles can be arranged on the wallpaper surface at a high density, and the base material is not eroded by the action of the photocatalyst, and preferably the photocatalyst particles are not easily cracked. It is intended to provide a sheet.

  The present invention provides a photocatalyst-equipped film or sheet for wallpaper having a structure in which a plastic film or sheet layer, a primer layer, and a photocatalytic thin film layer are sequentially laminated.

  Since the film or sheet of the present invention can form a photocatalyst thin film layer on a plastic film or sheet and can be applied to a wallpaper substrate together with the plastic film or sheet, a wallpaper with a photocatalyst can be formed. . In addition, even with a relatively small amount of photocatalyst, the photocatalyst can be arranged with high density on the wallpaper surface, so that a product with high performance can be provided at a lower cost. Furthermore, since the primer layer is interposed between the plastic film or sheet layer and the photocatalytic thin film layer, the plastic film or sheet layer can be prevented from being soaked and deteriorated by the photocatalytic action.

Next, this invention is demonstrated based on embodiment.
However, the embodiment described below is an example of the embodiment of the present invention, and the scope of the present invention is not limited to the following embodiment.

As shown in FIG. 1, a film or sheet with photocatalyst for wallpaper (hereinafter referred to as “transparent film with photocatalyst”) 1 is formed by sequentially laminating a plastic film or sheet layer 2, a primer layer 3, and a photocatalytic thin film layer 4. Can be configured.
In the present invention, “transparent” means to include colored transparency and translucent.

(Plastic film or sheet layer)
“Plastic film or sheet layer 2” as a base layer of the transparent film 1 with a photocatalyst is made of polyester such as polyethylene terephthalate, vinyl chloride resin, acrylic resin, polycarbonate, polyimide, polyethylene, polypropylene, ethylene-vinyl alcohol copolymer It can be formed from a film or sheet mainly composed of coalescence (EVOH) or other synthetic resin.
In the present invention, the “main component” means that at least 50% or more of all components may be included and other components may be included.

The plastic film or sheet layer 2 is preferably formed from a film or sheet having an elastic modulus of 100 MPa or more, preferably 100 MPa to 10,000 MPa, at 80 ° C. or more and 130 ° C. or less. Since the drying temperature when forming the photocatalyst layer is about 80 ° C. to 130 ° C., if the elastic modulus at 80 ° C. or higher and 130 ° C. or lower is 100 MPa or higher, elongation during drying can be suppressed, and cracking of the photocatalyst particles can be prevented. Can be suppressed.
Among them, the elastic modulus at 80 ° C. or higher and 130 ° C. or lower is 100 MPa or higher, preferably 100 to 10,000 MPa, and the elastic modulus at 150 ° C. or higher and 190 ° C. or lower is 100 MPa or lower, particularly preferably 10 to 0.01 MPa. Particularly preferably, it is formed from a film or sheet having a pressure of 1 to 0.1 MPa. If the elastic modulus at 150 ° C. or more and 190 ° C. or less is 100 MPa or less, it is possible to give a concavo-convex pattern such as embossing neatly in the temperature range. In addition, when the temperature at the time of uneven | corrugated pattern provision is more than the said temperature range, a crack will come to arise in a photocatalyst particle.
Specifically, the elastic modulus at 80 ° C. or higher and 130 ° C. or lower is 100 to 10,000 MPa, and the elastic modulus at 150 ° C. or higher and 190 ° C. or lower is 100 MPa or lower, particularly preferably 10 to 0.01 MPa. It is preferably formed from a film or sheet mainly composed of ethylene-vinyl alcohol copolymer (EVOH) or polyester of 1 to 0.1 MPa.
The thickness of the plastic film or sheet layer 2 is 10 to 100 μm, particularly 10 to 80 μm, and particularly preferably 10 to 50 μm.
The surface of the plastic film or sheet layer 2 may be appropriately subjected to surface treatment as necessary. For example, surface treatment with a corona treatment, silicone, fluorine or other release agent may be performed. Moreover, you may mix the additive which improves a weather resistance, chemical resistance, stain resistance, abrasion resistance, etc.

(Primer layer)
The primer layer 3 can be prepared from inorganic oxide particles, a silicone resin, a silicone resin precursor or a silica precursor, or a composition containing these as a main component. Among these, it is preferable to prepare from a composition containing as a main component any one of an acrylic silicone resin, an acrylic-modified silicone resin, an alkoxysilane, or a combination of two or more of these.
The thickness of the primer layer 3 is preferably 0.01 to 5 μm, particularly 0.05 to 3 μm, and particularly preferably 0.1 to 1 μm.

  The means for applying the primer layer 3 is not particularly limited. For example, various coating methods such as gravure coating, spray coating, dip coating and the like can be selected.

  By forming the primer layer 3, the wettability with the photocatalytic thin film layer 4 can be improved, and the plastic film or the sheet layer 2 can be prevented from being eroded by the action of the photocatalyst.

(Photocatalytic thin film layer)
The photocatalyst thin film layer 4 can be formed by applying a coating liquid containing photocatalyst particles on the primer layer 3 and drying it. However, it is not limited to this formation method.

Examples of the photocatalyst of the photocatalytic thin film layer 4 include metal oxides such as titanium dioxide, zinc oxide, tin oxide, lead oxide, ferric oxide, dibismuth trioxide, tungsten trioxide, and strontium titanate. Fe, Co, Ni, Cu, Zn, Ru, Rh, Pd, Ag, Pt, Au, or the like may be added to these. Among these, titanium dioxide is preferable because it is harmless, chemically stable, and inexpensive. As the titanium dioxide, any of anatase-type titanium dioxide, rutile-type titanium dioxide, and Brooklight-type titanium dioxide can be used, but those mainly composed of anatase-type titanium dioxide having high activity of photocatalytic reaction are preferred.
The particle size of the photocatalyst particles is not particularly limited, but those having an average particle size of 1 to 500 nm, particularly 3 to 400 nm, and particularly 5 to 300 nm are preferred by the dynamic scattering measurement method. If it is this range, the transparency of a photocatalyst thin film layer is securable.
Further, the specific surface area of titanium dioxide needs to be 50 m ² / g or more after drying at 100 ° C. If it is more than this, a large catalytic effect can be expected.
In addition, it is preferable that the decomposition activity calculated | required by the photocatalyst of this invention is 0.01% or more in conversion of a quantum efficiency, especially 0.05 to 5%, especially 0.1 to 2%.
At this time, the quantum efficiency indicating the decomposition activity of the photocatalyst is obtained by continuously irradiating a 10 × 10 cm sample piece with 1 mW / cm ² · sec ultraviolet rays (UV) for 24 hours (pretreatment), and applying n− to the pretreated sample piece. 0.0141 g of octadecane is dropped and applied uniformly, and the weight of the sample piece is measured. Next, UV of 1 mW / cm ² · sec by black light is continuously irradiated from directly above the sample piece, the weight of the sample piece is measured over time, and the time when the remaining amount of n-octadecane becomes 0 is measured. . Based on the measured value thus obtained, the quantum efficiency (φ) can be calculated from the decomposed octadecane amount by the following formula (1).
φ = {(decomposed octadecane weight / molecular weight) × Avocado number} / {1.84 × 10 ¹⁵ × UV irradiation time (sec)} (1)

As described above, the photocatalytic thin film layer 4 can be formed by applying a photocatalyst coating liquid containing a photocatalyst.
At this time, the photocatalyst coating liquid can be prepared by mixing a solvent containing “organic solvent” and “water” and photocatalyst particles, and a solvent containing an organic solvent and water can contain a silane coupling agent or the like. It is preferable to include an “inorganic binder”. The inorganic binder can increase the adhesion of the photocatalyst particles and improve the strength of the film by the photocatalyst.

When preparing the photocatalyst coating liquid, it is possible to mix the photocatalyst in a powder state, but it is preferable to prepare and mix in a slurry form or a sol form as described below.
That is, the photocatalyst is preferably prepared in a slurry or sol state with less sedimentation and added and mixed. Commercially available titanium dioxide slurry or sol may be used as long as necessary physical properties are satisfied.
Further, it is preferable that a dispersion stabilizer is allowed to coexist in order to prevent a change in particle diameter due to particle aggregation and sedimentation. These dispersion stabilizers can coexist from the time of preparing the particles, or may be added when preparing the photocatalyst coating liquid.
Various kinds of chemicals can be used as the dispersion stabilizer, but since titanium dioxide tends to aggregate near neutrality, an acidic or alkaline dispersion stabilizer is preferably used. Examples of the acidic dispersion stabilizer include mineral acids such as nitric acid and hydrochloric acid, and organic acids such as carboxylic acid, oxycarboxylic acid and polycarboxylic acid. Examples of the alkaline dispersion stabilizer include one or more compounds selected from carboxylic acids, alkali metal salts of polycarboxylic acids and ammonia, primary to quaternary amines, and alkanolamines having a hydroxy group added thereto. Can be mentioned. In particular, use of an organic acid is preferable because it has good miscibility with an organic solvent described later, and does not extremely lower the pH and corrodes the equipment used during production. As the organic acid, acetic acid, oxalic acid, glycolic acid, lactic acid, tartaric acid, malic acid, citric acid and the like can be preferably used, and the dispersion can be stabilized with one or more acids selected from these.

  Examples of the “organic solvent” of the photocatalyst coating liquid include monohydric lower alcohols such as methyl alcohol, ethyl alcohol, and isopropyl alcohol, polyhydric alcohols such as ethylene glycol and propylene glycol, and esters thereof such as cellosolve, ethyl acetate, and methyl. Isobutyl ketone, isobutanol, methyl ethyl ketone, toluene, xylene and the like can be suitably used. Monovalent lower alcohols, particularly isopropyl alcohol and ethanol are preferably used.

As the “inorganic binder”, a silica compound is preferably used, and as the silica compound, 4, 3, or bifunctional alkoxysilanes, and condensates, hydrolysates, silicone varnishes, or the like of these alkoxysilanes can be used. . The trifunctional or bifunctional alkoxysilane is generally often referred to as a silane coupling agent, but in the present invention, a compound in which one or more alkoxy groups are bonded to one silicon molecule is referred to as an alkoxysilane. Specifically, tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane as tetrafunctional alkoxysilane, methyltrimethoxysilane, methyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, Vinyltrimethoxysilane, vinyltriethoxysilane, methacryloxypropyltrimethoxysilane, glycidpropoxytrimethoxysilane, glycylpropylpropyldiethoxysilane, aminopropyltriethoxysilane, aminoethylaminopropyltrimethoxysilane, mercaptopropyltrimethoxy Silanes, bifunctional alkoxysilanes include dimethyldimethoxysilane, dimethyldiethoxysilane, diphenyldimethoxysilane, diphenyl Such as diethoxy silane.
Examples of the condensate include, but are not limited to, condensates of tetrafunctional alkoxysilanes such as ethyl silicate 40, ethyl silicate 48, and methyl silicate 51.
As a hydrolyzate, what hydrolyzed the alkoxysilane using the organic solvent, water, and the catalyst can be used. Among these silica compounds, tetramethoxysilane, tetraethoxysilane, ethyl silicate 40, ethyl silicate 48, methyl silicate 51, and alcoholic silica sol as a hydrolysis product thereof can fix the film firmly and relatively It is particularly suitable because it is inexpensive. The method for producing such an alcoholic silica sol is not particularly limited, and the alkoxysilane may be hydrolyzed in the photocatalyst coating liquid, or the alkoxysilane is hydrolyzed or partially hydrolyzed, and the alcoholic silica sol has already been produced. The resulting product may be added to the photocatalyst coating solution.
In mixing the inorganic binder, it is preferable to use a “solvent” in order to mix and stabilize the binder liquid and the aqueous titanium dioxide dispersion.
As the type of “solvent”, monohydric lower alcohols such as methanol, ethanol, propanol and butanol, polyhydric alcohols such as ethylene glycol and propylene glycol, and cellosolve which is an ester thereof can be used as good solvents.
The inorganic binder may be premixed and stored in the photocatalyst coating solution, but if the binder component is deteriorated by a normal storage method, it is used by mixing with the titanium dioxide-containing photocatalyst coating solution immediately before use. You can also.

Regarding the composition of the coating liquid containing the photocatalyst particles, it is preferable to mix the photocatalyst particles in a solid concentration of 0.2 to 20% by weight, particularly 5 to 10% by weight. If it is 5% or more, the effect of the photocatalyst after coating is great, and the effect of preventing contamination is sufficiently exhibited. If it does not exceed 10%, the appearance does not become white (not transparent), and the photocatalyst does not fall off even when the temperature is raised. Also, the viscosity does not become too high.
The inorganic binder (silica compound) preferably contains 0.05 to 5% by weight, particularly 1 to 2% by weight. When the binder is too much, not only the stability of the photocatalyst coating liquid is inhibited, but also the surface of titanium dioxide is covered and the catalytic effect is greatly reduced.
Specifically, a photocatalyst coating liquid containing 0.2 to 20% by weight of titanium dioxide particles having an average particle diameter of 3 to 100 nm and 0.1 to 5% by weight of silica compound as SiO ₂ is preferable. . When the binder is added to the photocatalyst coating liquid and stored for a long time, the content of the silica compound is more preferably 2.5% by weight or less.
In addition, the quantity of a solvent can be adjusted with 5-90 weight% with respect to the whole photocatalyst coating liquid.
In order to increase the viscosity of the photocatalyst coating liquid, a thickener such as a water-soluble polymer may be further added. Examples of the thickener include polysaccharides, polyvinyl alcohol, and polyethylene oxide.

The means for applying the coating liquid containing photocatalyst particles is not particularly limited. For example, various coating methods such as gravure coating, spray coating, and dip coating can be selected. It is preferable to use a gravure roll coater. The coating liquid may be applied not only once but a plurality of times.
It is preferable to heat and dry after applying the coating solution. In this case, the heat drying is preferably performed at a heating temperature of 80 to 100 ° C. Furthermore, it is good to carry out on the conditions of drying hot air wind speed 10-30 m / sec and drying time 20-180 seconds.
It is preferable to perform aging for the required time after the drying of the photocatalytic thin film layer 4 is completed. Thereby, the peeling strength of the coated film can be improved. Aging is preferably performed at 30 to 60 ° C. for 30 hours or more.

The coating thickness of the photocatalyst coating solution, that is, the thickness of the photocatalytic thin film layer 4 is preferably 0.5 μm or less, particularly 0.1 to 0.5 μm, particularly preferably 0.2 to 0.5 μm in terms of the thickness of the coating after drying. . If it is 0.5 μm or less, the activity of the photocatalytic reaction is high, the adhesion strength and the surface hardness are preferable, and the peeling of the film can be prevented.
In addition, you may comprise a photocatalyst thin film layer by the multiple layer comprised by the photocatalyst particle of a different average particle diameter.

(Wallpaper with photocatalyst)
If the transparent film 1 with a photocatalyst is laminated on the wallpaper substrate 5 through the adhesive layer 6, the wallpaper 10 with a photocatalyst can be formed.
At this time, as shown in FIG. 2, the printed pattern layer 7 can also be formed on the surface of the wallpaper 10 with photocatalyst.
Moreover, as shown in FIG. 3, after forming the printed pattern layer 7, uneven | corrugated patterns, such as an embossed pattern, can also be given to the surface of the wallpaper 10 with a photocatalyst.

As the wallpaper base material 5, paper-based, wood-based, cloth-based, synthetic resin-based, other known sheet materials (including laminated sheets) used for wallpaper, or unknown sheet materials (including laminated sheets) are used. Can do. For example, a flame retardant paper mainly composed of cellulose fiber (pulp), an inorganic paper obtained by mixing aluminum hydroxide or the like can be suitably used. However, it is not limited to these.
The thickness of the wallpaper base material 5 is generally 40 μm to 1 mm.

The printed pattern layer 7 may be formed on the surface of the wallpaper base material 5. Since the transparent film 1 with a photocatalyst is excellent in transparency, the printed pattern layer 7 and the concavo-convex pattern can be displayed beautifully, and the design of the wallpaper can be improved.
Alternatively, an adhesive layer may be provided in advance on the back surface of the wallpaper base material 5 and a release paper may be adhered to the surface of the adhesive layer.

(Adhesive layer)
The adhesive layer 6 is preferably selected as appropriate in consideration of the material of the wallpaper substrate 5. For example, when the wallpaper substrate 5 is made of a synthetic resin material, the adhesive layer preferably contains an acrylic resin, an acrylic modified silicone resin compound, or a silicon modified acrylic resin compound as a main component. Taki Chemical Co., Ltd. Product name: Tynock Primer A (containing 20% silicon-modified resin as solid content, 30% colloidal silica, 20% ethanol as solvent, 20% 2-propanol, 10% pure water), etc. It can be preferably used.
The thickness of the adhesive layer 6 is not particularly limited, but is preferably 0.2 μm or more. The adhesive layer 6 may contain photocatalyst particles.

  The means for applying the adhesive layer 6 is not particularly limited, as is the case with the means for applying the coating liquid containing photocatalyst particles. For example, various coating methods such as gravure coating, spray coating, and dip coating can be selected. It is preferable to use a gravure roll coater.

  The means for laminating the wallpaper substrate 5 and the transparent film 1 with a photocatalyst is arbitrary. For example, the transparent film with photocatalyst 1 and the wallpaper base material 5 may be pulled out from different rollers, and the adhesive layer 6 may be interposed between the transparent film 1 and the wallpaper base material 5 so as to be bonded with a pressure roller.

  The wallpaper 10 with photocatalyst is applied to the wall or ceiling surface of the room to receive sunlight or light from the room light, and the photocatalyst is photoexcited to exhibit the photocatalytic function. It decomposes and removes pathogenic bacteria, molds, malodorous substances, tobacco spiders, pathogenic bacteria, molds, etc. adhering to the wallpaper surface over a long period of time. In addition, it reacts with a small amount of moisture in the air to generate reactive oxygen species such as hydroxyl radicals and superoxide ions, which acts on malodorous substances and bacteria, and separates and decomposes the composition. .

  Examples of the present invention will be described below, but the present invention is not limited to these examples. In addition, unless otherwise indicated,% shows weight%.

<Example 1>
(A) Step of applying a base layer to the surface of a synthetic resin film or sheet On the surface of an EVOH film “EVAL HF-ME” (25 μm thickness) manufactured by Kuraray Co., Ltd., a silicon-containing acrylic resin paint “manufactured by Taki Chemical Co., Ltd.” The primer layer of “Primer A” was formed with a gravure roll coater. The roll speed was 50 m / min, the coating amount was 1 g / m ² , and the drying temperature was 130 ° C.
Note that the elastic modulus of EVAL HF-ME at 80 ° C. or higher and 130 ° C. or lower is 1000 MPa, and the elastic modulus at 150 ° C. or higher and 190 ° C. or lower is 10 MPa.

(B) Step of forming a photocatalytic film on the primer layer Next, the “photocatalyst coating liquid A” produced in the following manner was coated on the primer layer with a gravure roll coater and dried. The roll speed was 50 m / min, the coating amount was 1 g / m ² , and the drying temperature was 130 ° C. This obtained the synthetic resin film (transparent film with a photocatalyst) which formed the photocatalyst film.
The obtained film was cut into a size of 10 cm × 10 cm square to obtain a sample piece, which was subjected to a methylene blue decomposition activity test, a tobacco dust decomposition test, a film strength test, a film hardness test, and a film adhesion test described later.

(Photocatalyst coating solution)
A slurry having an average particle size of 0.3 μm obtained by adding citric acid as a dispersant (0.1 mol to titanium oxide) to titanium oxide P-25 (anatase type) manufactured by Nippon Aerosil Co., Ltd. A), Taki Chemical Co., Ltd. Titanium Oxide Sol M-6 (anatase type, average particle size 20 nm) (B), and Taki Chemical Co., Ltd. Titanium Oxide Sol M-5 (anatase type, average particle size 5 nm) ) (C) and tetraethoxysilane (D) manufactured by Kanto Chemical Co., Ltd. in terms of oxide (TiO ₂ , SiO ₂ ), respectively (B) / ((A) + (B) + (C)) × 100 = 10%, (D) / ((A) + (B) + (C) + (D)) = 20% The mixture was mixed, diluted with water and ethanol, and converted to oxide ( TiO _2, total solids concentration of 8% of SiO _2), 50% ethanol in the "photocatalyst coating liquid a" obtained .

<Comparative Example 1>
Asfabric Co., Ltd. “Fabric Wall (registered trademark) No. 1007” was cut into a 10 cm × 10 cm sample and used as a sample piece. Methylene blue decomposition activity test, tobacco disintegration test, film strength test, film hardness test, film adhesion, which will be described later It was subjected to a force test.

<Comparative example 2>
A photocatalyst-impregnated wallpaper was prepared by impregnating Kishu Paper nonwoven fabric (flame retardant paper) with a thickness of 120 μm with the “photocatalyst coating liquid A” of Example 1 and drying at 130 ° C. for 2 hours. This was cut into a size of 10 cm × 10 cm, and used as a sample piece for a methylene blue decomposition activity test, a tobacco dust decomposition test, a film strength test, a film hardness test, and a film adhesion test described later.

(Degradation activity test using methylene blue)
Operating procedure:
a. The coated surface of the test piece is irradiated in advance with 1 mW / cm ² (*) of ultraviolet light (365 nm) for 24 hours.
b. 2 mL of 10-5 mol / L methylene blue aqueous solution is added dropwise.
c. The color of the methylene blue aqueous solution is visually confirmed in 120 minutes after irradiation with ultraviolet rays having an intensity of 1 mW / cm ² .

 Judgment: Judgment was made by the fact that the color of the dropped methylene blue solution disappeared compared to the initial color.

(Tobacco crab degradation test)
Place the above sample in a 30 cm x 30 cm x 30 cm sealed container, smoke one cigarette (JT Mild Seven), take out the test piece after 30 minutes, and apply 365 m of ultraviolet light at 1 mW / cm ² with a black light. Irradiated for hours. Thereafter, the degree of yellowing was measured by the method described in ASTM D1925. This series of cycles was performed 20 times.

(Membrane strength test)
The film strength of the sample pieces obtained in Example 1, Comparative Example 1 and Comparative Example 2 was measured by the following method.

The glass samples prepared in Examples and Comparative Examples were evaluated by repetitive scratching with a plastic eraser described in JISR 6050 in which a weight of 1 kg / cm ² was applied. AA when the film has not disappeared after 200 scratches, A when the film disappears after 100 to 200 scratches, B when the film disappears after 50 to 100 times, and a film after less than 50 times. What disappeared was evaluated as C. The results are shown in Table 1.

(Film hardness test)
The film hardness of the sample pieces obtained in Example 1, Comparative Example 1 and Comparative Example 2 was measured by the following method.

Test method: According to the handwriting method of the “pencil hardness” test of JIS K 5400.
Pencil used: Dragonfly pencil No. 8900 specified by JIS S 6006 Pencil hardness: 4B, 3B, 2B, B, HB, H, 2H, 3H, 4H, F
Test method: (1) Needle tip condition and scratch angle (see Fig. 4)
(2) Draw five 30cm lines by hand with a pencil of the same hardness, wash with water (remove pencil powder), and visually check the surface condition after drying.
Judgment method: The judgment value is the hardness of the pencil one lower level where scratches (not subject to “dent” due to pressure: described in JIS) are recognized in two or more of the five.

(Film adhesion strength test)
Film adhesion strength test of sample pieces obtained in Example 1, Comparative Example 1 and Comparative Example 2 The film hardness was measured by the following method.

Test method: According to a cross tape method adhesion evaluation method of JIS K 5400.
Cellophane: Nichiban “Cellotape (registered trademark)” satisfying 2.94 N / 10 mm or more described in JIS Z 1522
Test procedure: (1) Using a cutter guide with a clearance interval described in JIS K 5400, make a cut on the grid of the test piece. When cutting, the knife edge was always new and kept at a constant angle in the range of 35-45 ° to the paint surface. The cuts were in a range that penetrated the coating but did not reach the substrate layer.
(2) The above-mentioned cellophane was applied from the top of the grid, and the entire surface was rubbed so as to crush bubbles with the above-mentioned eraser.
(3) One minute after the tape was attached, it was peeled off instantaneously while holding one end of the tape and keeping it perpendicular to the coating surface.
Evaluation: The state in which the coating film remained after the tape was peeled off was visually observed.
The evaluation score at that time is as shown in Table 2 below.

It is sectional drawing shown in order to demonstrate the structure of the film | membrane with a photocatalyst for wallpaper based on an example of this invention thru | or a sheet | seat (transparent film with a photocatalyst). It is sectional drawing shown in order to demonstrate an example of the wallpaper with a photocatalyst for film | membrane thru | or a sheet | seat (transparent film with a photocatalyst) for wallpaper based on an example of this invention. It is sectional drawing shown in order to demonstrate another example of the wallpaper with a photocatalyst formed using the photocatalyst-attached film thru | or sheet | seat (transparent film with a photocatalyst) concerning an example of this invention. It is a figure explaining the method of a pencil hardness test.

Explanation of symbols

1 Photocatalyst film or sheet for wallpaper (transparent film with photocatalyst)
2 Plastic film or sheet layer 3 Primer layer 4 Photocatalytic thin film layer 5 Wallpaper substrate 6 Adhesive layer 7 Print pattern layer 10 Photocatalyst wallpaper

Claims (8)

  A film or sheet with a photocatalyst for wallpaper, comprising a structure in which a plastic film or sheet layer, a primer layer, and a photocatalytic thin film layer are sequentially laminated.   The film or sheet with a photocatalyst for wallpaper according to claim 1, wherein the plastic film or sheet layer is formed from a film or sheet having an elastic modulus of 100 MPa or more at 80 to 130 ° C.   The plastic film or sheet layer is formed from a film or sheet having an elastic modulus at 80 ° C. or higher and 130 ° C. or lower of 100 MPa or higher and an elastic modulus at 150 ° C. or higher and 190 ° C. or lower of 100 MPa or lower. The film or sheet with a photocatalyst for wallpaper according to claim 1 or 2.   The film or sheet with a photocatalyst for wallpaper according to any one of claims 1 to 3, wherein a main component of the plastic film or sheet layer is ethylene-vinyl alcohol copolymer (EVOH) or polyester.   The film or sheet with a photocatalyst for wallpaper according to any one of claims 1 to 4, wherein the thickness of the photocatalytic thin film layer is 0.5 µm or less.   The film or sheet with a photocatalyst for wallpaper according to any one of claims 1 to 5, wherein the photocatalytic thin film layer contains anatase type titanium oxide as a photocatalyst.   The film or sheet with a photocatalyst for wallpaper according to any one of claims 1 to 6, wherein the particle diameter of the photocatalyst contained in the photocatalytic thin film layer is 1 to 500 nm. The film or sheet with a photocatalyst for wallpaper according to any one of claims 1 to 7, wherein the decomposition activity of the photocatalyst contained in the photocatalytic thin film layer is 0.01% or more in terms of quantum efficiency.

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