JP2001079420A - Photocatalytic functional body and method for producing the same - Google Patents

Abstract

(57) [Problem] The present invention provides a photocatalyst functional body having more versatility for these photocatalysts and easy to form a film. SOLUTION: Photocatalyst particles 2 provided with optical semiconductor particles 2a
Is sprayed onto the surface of the substrate 1 by a low-temperature thermal spraying method to form a film of the photocatalyst particles 2, and the particle diameter of the optical semiconductor particles 2 a is 25 to 50 μm. Further, the distance between the nozzle for jetting the photocatalyst particles and the substrate is set to 8
Injecting the photocatalyst particles while relatively moving them at a speed in the range of 20 m / min to 50 m / min while keeping them in the range of 0 to 90 mm or 120 to 150 mm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to paper products, cloth products,
The present invention relates to a photocatalyst functional body adhered onto a base material such as a plastic product, a metal product, and a ceramic ball and exhibiting excellent sterilizing power and deodorizing power over a long period of time, and a method for producing the same.

[0002]

BACKGROUND ART In recent years, bacteria existing in our living environment,
Research on photocatalysts as substances that decompose viruses, harmful substances, and the like has been conducted. The applicant of the present invention has disclosed a photocatalyst having a photocatalyst having a bactericidal action or the like by spraying photocatalyst particles on the surface of a base material as disclosed in Japanese Patent Application Laid-Open No.
448.

[0003]

SUMMARY OF THE INVENTION The present invention provides a photocatalyst functional body which is more versatile for these photocatalysts and can easily form a film, and a method for producing the same.

[0004]

According to a first aspect of the present invention, there is provided a photocatalyst functional body formed by spraying photocatalyst particles provided with optical semiconductor particles on a substrate surface by a low-temperature spraying method to form a photocatalyst film. The optical semiconductor particles have a particle size of 25 to 50 μm.
The above problem is solved by a photocatalyst functional body of m.

According to a second aspect of the present invention, there is provided a photocatalyst functional body having a photocatalyst film formed by spraying photocatalyst particles provided with optical semiconductor particles onto a substrate surface by a low-temperature spraying method. The above problem is solved by a photocatalytic functional body having a particle size of 35 to 45 μm.

According to a third aspect of the present invention, in the photocatalytic function body according to the first or second aspect, the optical semiconductor particles are titanium oxide (TiO ₂ ).

According to a fourth aspect of the present invention, there is provided a method for producing a photocatalyst functional body in which a photocatalyst film is formed by spraying photocatalyst particles on a surface of a base material, wherein the nozzle for jetting the photocatalyst particles, the base material, 20m while keeping the distance of
The above object is achieved by a method for manufacturing a photocatalyst functional body that injects the photocatalyst particles while relatively moving at a speed in a range of / m to 50 m / min.

According to a fifth aspect of the present invention, in the method for manufacturing a photocatalyst functional body according to the fourth aspect, the method for manufacturing the photocatalyst functional body may be such that a distance between the substrate and the injection nozzle is 80 mm.
It is characterized in that the photocatalyst particles are jetted in a range of up to 90 mm.

According to a sixth aspect of the present invention, in the method for manufacturing a photocatalyst functional body according to the fourth aspect, the method for manufacturing the photocatalytic functional body includes a step of setting a distance between the base material and the injection nozzle to 120 m.
The photocatalyst particles are jetted in a range of m to 150 mm.

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a state in which photocatalyst particles are adhered to the surface of a substrate 1 by a low-temperature thermal spraying method. Substrate 1
For example, non-woven fabric, woven fabric, paper, wood, ceramic plate, metal plate, plastic plate and the like are used. The photocatalyst particles 2 attached to the surface of the substrate 1 shown in FIG.
O ₂ ) fine particles 2a and silver particles 2b as metal particles are melted and sprayed at about 2900 to 3000 ° C. by a gas spraying method using oxygen, acetylene or the like. It is to be noted that titanium oxide (TiO ₂ ) as the sprayed optical semiconductor particles may use fine particles having a particle diameter of 25 to 50 μm, preferably 35 to 45 μm. on the other hand,
As silver particles as metal particles, particles having a particle size of 1 to 10 μm are preferably used. According to the optical semiconductor particles having a particle diameter in the range shown here, appropriate kinetic energy can be given to each photocatalyst particle at the time of thermal spraying, and a film having a strong adhesive force can be formed on the substrate. On the other hand, when the particle size is 2
In both cases of smaller than 5 μm and larger than 50 μm, only small kinetic energy can be given to the sprayed particles, and only a film having a weak adhesive force can be formed.

The photocatalyst particles 2 composed of titanium oxide and silver particles form an electrochemical cell, and after thermal spraying, 30 to 40 minutes.
The particles become particles of μ and adhere to the substrate 1 by the anchor effect while being melted by the high temperature of the gas. The titanium oxide particles 2a and the silver particles 2 carried on the titanium oxide particles 2a
b acts as an electrode. When titanium oxide has a strong photocatalytic action, silver particles as electrodes are unnecessary.

In the low-temperature thermal spraying method using gas spraying using oxygen, acetylene, etc., a gas torch as a thermal spray gun for spraying fine particles of molten photocatalyst and a substrate 1 are relatively moved so that the surface of the substrate can reach 50 ° C. or higher. It is performed so as not to go up, so that thermal spraying can be performed on paper, cloth, and the like. However, the melting point of the raw material powder is limited to 2000 ° C. or lower. The torch and the substrate 1
Plasma spraying is also possible by adjusting the relative speed with respect to the temperature.
Thermal spraying up to about 0 ° C is possible.

The photocatalyst particles 2 have effects such as sterilization, decomposition, and deodorization.
The ability to adsorb harmful substances and odorous components is extremely weak. Therefore, it is preferable to spray together the optical semiconductor particles and the metal particles with the adsorbent 3 that adsorbs bacteria and the like.

The distance L between the base material 1 and the spray nozzle 4 of the spray gun shown in FIG. 2 affects the strength of the photocatalyst particles 2 adhering to the base material 1 and depends on the type of the base material 1. The distance L can be changed. As in the present invention, the surface temperature of the substrate 1 is set to 50
° C. or less and spraying photocatalyst particles having a particle size of 25 to 50 μm, the base material 1 may be made of a metal material such as steel or stainless steel in consideration of the spread of the photocatalyst particles injected from the injection nozzle 4. Then, the distance L should be set to 80 to 90 mm, preferably around 85 mm. On the other hand, when the substrate 1 is a non-woven fabric, a woven fabric, a polyester, or the like, the distance L is set to 1
It is good to be 20-150 mm, preferably around 130 mm. If the injection nozzle 4 is farther from the substrate 1 than the distance shown here, a sufficient collision force of the particles against the substrate 1 cannot be obtained, and the force for adhering the particles decreases. Conversely, if the distance is shorter than the distance shown here, the surface temperature of the substrate 1 increases, which is not preferable. Further, the spray nozzle 4 of the thermal spray gun and the substrate 1 are relatively moved while maintaining this distance L.
At this time, only the injection nozzle 4 may be moved along the surface of the substrate 1 or the injection nozzle 4 may be fixed as it is
May be moved. Further, both the spray nozzle 4 and the substrate 1 may be moved at the same time. In order to keep the surface temperature of the substrate 1 at 50 ° C. or lower and to surely attach the photocatalyst particles 2 to the substrate 1, the relative moving speed between the injection nozzle 4 and the substrate 1 should be 20 m / min to 50 m. / Min. If the relative speed is lower than 20 m / min, the surface temperature of the substrate will increase. If the substrate is a combustible material such as a nonwoven fabric, the substrate may burn, which is not preferable. On the other hand, when the relative speed is higher than 50 m / min, the particles of the photocatalyst cannot be appropriately attached to the surface of the substrate, which is not preferable.

Under these conditions, when the photocatalyst particles having the photo-semiconductor particles having a particle size of 25 to 50 μm are thermally sprayed, the substrate 1
Can form a photocatalyst functional body strongly adhered to
It can be used for a wide variety of applications.

The photo-semiconductor particles of the photocatalyst particles include:
In addition to TiO ₂ , CdS, CdSe, WO ₃ , Fe ₂ O ₃ , S
rTiO ₃ , KNbO _{3 and the} like can be mentioned. As the metal particles forming the electrode, various metal particles such as gold, platinum, and copper can be used in addition to silver. In addition, since the metal particles require water as one of the indispensable elements for the photocatalyst to exhibit its original function, it is necessary that the metal particles be stable without change over time in the presence of water. For this reason, platinum is most preferable among the above metal particles, but silver is preferable because it has the above characteristics in consideration of economy, and is non-toxic and has sterilization itself. However,
The electrodes are not necessarily limited to metals, and it has been found that, for example, silicon Si can be used instead of these metals, and the silicon electrodes also cause electron transfer. Silver, gold, platinum and the like are expensive and the use of silicon has a great economic effect.

[0018] The adsorbent is used for bacteria, viruses and fungi.
In addition, adsorbs and retains processing objects such as odorous substances and harmful substances
It is for doing. Such adsorbents include Apata
Cellite (apatite), zeolite or sepiolite
A group consisting of lamic particles, activated carbon and silk fiber content
One or more of these can be chosen
Two or more can be used in combination depending on the situation. here
Apatite includes proteins such as bacteria, viruses, molds, etc.
Hydroxyapatite [Ca_Ten
(PO_Four)₆(OH)_TwoIs preferred. Also, silk fiber content
In addition to silk fiber powder,
Gels and the like are also included. These adsorbents (silk fiber content
Is the case of powder) and ensure a larger surface area
In both cases, 0.001 to 0.001
1.0 μm is preferred, and particularly 0.01 to 0.05 μm
preferable. The mixing ratio of the optical semiconductor particles and the adsorbent is sterilized,
In order to suitably exhibit a deodorizing effect, etc., the optical semiconductor particles 1
The adsorbent is 1 to 50 parts by weight based on 00 parts by weight
Is preferred, and particularly preferably 10 to 30 parts by weight.
New The origin of the thermal spray coating mixed with hydroxyapatite
The charge is TiO as an example. _Two80% by weight, Ag 10% by weight
%, And 10% by weight of hydroxyapatite are preferred.

As shown in FIG. 3, the photocatalyst functional body of the present invention may be inferior to a conventional antibacterial agent in terms of immediate effect, but since it is a non-eluting type, it hardly dissolves in a liquid. And the effect will last for a long time. Therefore, if a conventional antibacterial agent, for example, zeolite fine particles carrying metal ions (Ag, Cu, Zn) having an antibacterial action is mixed with photocatalytic particles (TiO ₂ + Ag) and sprayed at a low temperature, there is an immediate effect, In addition, it can be a long-lasting antibacterial and bactericide.

Next, when using a photocatalyst, depending on the object,
It may be necessary to control the intensity of the photocatalytic action, but factors that weaken the photocatalytic function include various metal ions or higher fatty acids. That is, when metal ions such as silver ions are introduced into the processing solution, or when mineral water or the like in which the metal ions are ionized is injected, the photocatalytic function is reduced. In the case of a skin disease, if an ointment or cream, which is a higher fatty acid, is applied thinly to the affected area, and then a towel to which a photocatalytic functional body is attached is applied, the antibacterial action of the towel decreases. In these cases, radicals (OH
This is because-) is trapped by metal ions or higher fatty acids.

Conversely, factors that enhance the photocatalytic function include:
Hydrogen peroxide (H_TwoO_Two), Ozone (O _Three) And UV rays
Exist. When these factors are added to the treatment target, radicals
(OH-) is generated at an accelerated rate to significantly enhance the catalytic action
Let me know. That is, H_TwoO_TwoOr O_Three1% for processing
Addition of only a few ppm accelerates the photocatalysis. Also,
H_TwoO_TwoOr O_ThreeTogether with the photocatalyst
It may be provided in the processing object. For example, PbO_TwoAnd precious metals
Or noble metal oxides (which do not normally elute)
Poles and H on the surface_TwoO_Two, O_ThreeIs generated, the processing target
Can give a strong photocatalysis.

Further, gypsum particles (Ca) are added to the sprayed photocatalyst.
Forming a film mixed with SO ₄ ) is effective in decomposing ethylene gas (C ₂ H ₄ ). Such a film is effective in maintaining the freshness of vegetables and fruits, and if vegetables and fruits are wrapped in wrapping paper (paper, cloth, etc.) on which such a film is formed, the freshness of the vegetables and fruits can be maintained for a long time.

In general, ceramics are excellent as a substance that emits far-infrared rays. However, the coating of TiO ₂ particles, which is a photocatalyst functional body of the present invention, by a low-temperature spraying method has a radiation characteristic close to a black body. It also functions as a good far-infrared radiation coating. For far-infrared radiators, the ratio of anatase to rutile is not critical, and low-temperature sprayed coatings do not necessarily require apatite as an absorber and metal as an electrode in a photocatalyst. Since the photocatalytic functional body of the present invention uses a fine powder before radiation, a dense film can be obtained and a material having good surface roughness is formed, so that the actual radiation area is large and the emissivity is good.
The large surface area of the coating and the large actual emission area mean that the photocatalyst functions as a favorable photocatalyst because contact with the object to be treated is required. In the case of a photocatalyst, when the substrate is a metal plate, a metal as an electrode is not always necessary.

Specific applications of the above-mentioned photocatalyst functional body include the following. (1) A photocatalytic film is formed on the surface of a sheet-like base material such as paper, nonwoven fabric, cloth, metal plate, etc. by low-temperature spraying. FIG. 4 shows the photocatalyst films 11, 11 formed on the substrates 10, 10 cut to a certain size, and FIG. 5 shows the photocatalyst film 13 formed on the surface in a roll shape. Each shows a long strip-shaped substrate 12.

Examples of this type of use include underwear for children, towels, diapers, bibs, pajamas, and even sheets for hospitals where the propagation of germs is a problem for fabrics. In addition, a photocatalyst film formed on a metal plate can be used, for example, as a wall plate of a kitchen, a floor plate, or a wall material such as a food storage, a medical instrument, or a storage for hygiene management.

As a modification of this type, it is conceivable to use a photocatalyst sheet having a fixed size with a release paper attached thereto. For example, as shown in FIG.
0, a photocatalytic film 21 is formed by a low-temperature spraying method, and a release paper 2 having an adhesive 22 on the back side of a polyester nonwoven fabric 20.
3, the release paper 23 is peeled off at the site, and is pasted on a wall. It is conceivable to use it as a small one of a certain size for a bandage for body treatment. As a substrate, P
Not only the ET non-woven fabric but also a stainless plate having a thickness of about 100 μ may be used. With respect to such a photocatalyst functional body, a photocatalytic stainless steel sheet of a certain size is brought to the site, where the release paper is peeled off and adhered to floors and walls of a food plant. (2) A photocatalytic layer is formed on a porous ball 30 of ceramic or the like by a low-temperature spraying method (see FIG. 7). Particularly, as shown in the figure, it is desirable that the balls 30 # 30 be made of a material having a specific gravity smaller than that of water and floating on the water surface. (3) The photocatalyst film 41 is formed on the fixed wall 40 such as a wall surface instead of the sheet-like base material (see FIG. 8), or a container having a specific shape according to the use, or a sanitary device. Form a film on the surface. FIG. 9 shows a scalpel 42 used for surgery or the like as a sanitary instrument, and a photocatalytic film 44 is formed on a surface 43 of a handle of the scalpel 42.

[0027]

As described above, according to the present invention, it is possible to obtain a photocatalyst functional body having a temperature of the substrate of 50 ° C. or less and a strong adhesive force to the substrate. Therefore, versatility is increased, and various products using this photocatalyst functional body can be manufactured.

[Brief description of the drawings]

FIG. 1 is a state diagram of photocatalyst particles sprayed by a low-temperature spraying method.

FIG. 2 is an explanatory diagram showing a positional relationship between an injection nozzle for spraying photocatalyst particles and a device on which a film is formed.

FIG. 3 is a graph showing a comparison of catalytic activity between a conventionally used antibacterial agent and the photocatalytic functional body of the present invention.

FIG. 4 is a perspective view in which a photocatalyst is attached to a sheet-like base material.

FIG. 5 is a perspective view showing a state in which a belt-shaped substrate having a photocatalyst film formed on the surface is wound into a roll.

FIG. 6 is a perspective view of a photocatalyst functional body having a fixed size provided with release paper.

FIG. 7 is a perspective view showing a state in which a ceramic ball having a photocatalytic film formed on its surface is floated in a water tank.

FIG. 8 is a diagram in which a photocatalyst is attached to a wall surface.

FIG. 9 is a perspective view of a scalpel having a photocatalyst film formed on a handle portion.

[Description of Signs] 1, 10, 12 Base material 2 Photocatalyst particles 2a Optical semiconductor particles (titanium oxide particles) 2b Metal particles (silver particles) 3 Adsorbent 4 Injection nozzle 11, 13, 21 Photocatalytic film 20 Polyester nonwoven fabric 22 Adhesive 23 Release Paper 30 Ceramic Ball 40 Fixed Wall 42 Female

[Procedure amendment]

[Submission date] March 30, 2000 (2003.3.3)
0)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0004

[Correction method] Change

[Correction contents]

[0004]

In [SUMMARY OF] of claim 1 invention, the photocatalyst particles with an optical semiconductor particles sprayed on the substrate surface,
The above object is solved by a photocatalyst functional body having a photocatalyst film formed thereon, wherein the optical semiconductor particles have a particle diameter of 25 to 50 μm.

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0005

[Correction method] Change

[Correction contents]

According to a second aspect of the present invention, there is provided a photocatalyst functional body having a photocatalyst film formed by spraying photocatalyst particles having photosemiconductor particles on the surface of a substrate, wherein the photosemiconductor particles have a particle size. The above problem is solved by a photocatalytic functional body having a diameter of 35 to 45 μm.

Claims (6)

[Claims] 1. A photocatalyst functional body in which a photocatalyst film provided with a photocatalyst film is formed by spraying a photocatalyst particle having a photocatalyst particle on a substrate surface by a low-temperature thermal spraying method. A photocatalytic function body having a size of 25 μm to 50 μm. 2. A photocatalyst functional body in which a photocatalyst film provided with a photocatalyst film is formed by spraying a photocatalyst particle provided with an optical semiconductor particle onto a substrate surface by a low-temperature thermal spraying method. A photocatalytic function body having a size of 35 μm to 45 μm. 3. The method according to claim 1, wherein the optical semiconductor particles are titanium oxide (Ti).
_{3. The} photocatalyst functional body according to claim 1, wherein the photocatalyst functional body is O ₂ ). 4. A method for producing a photocatalyst functional body in which a photocatalyst film is formed by spraying photocatalyst particles on a surface of a substrate, wherein a distance between a nozzle for jetting the photocatalyst particles and the substrate is kept constant. While keeping these, 20m / min to 50m / m
A method for producing a photocatalyst functional body, wherein the photocatalyst particles are jetted while relatively moving at a speed in a range of in. 5. The photocatalyst according to claim 4, wherein in the method for producing a photocatalyst functional body, the photocatalyst particles are jetted at a distance between the substrate and the jet nozzle in a range of 80 mm to 90 mm. A method for manufacturing a functional body. 6. The method for producing a photocatalyst functional body, wherein a distance between the base material and the injection nozzle is 120 mm to 150 mm.
The method for producing a photocatalyst functional body according to claim 4, wherein the photocatalyst particles are injected in the range of: