JP2001149451A - Photocatalyst member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photocatalyst member having heat exchanging property, preferably total heat exchanging property, and excellent in air cleaning property. SOLUTION: The photocatalyst member is constructed by laminating partition plates (1) having heat transfer property, and preferably moisture permeability, so as to form a plurality of layers with prescribed intervals, and carrying a photocatalyst in the ends (5) of the air permeable faces of the photocatalytist member molded so that primary air stream (3) and secondary air stream (4) may permeate through the layers alternately.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photocatalyst member having excellent heat exchange properties and having an excellent air purifying action such as deodorizing property or antibacterial property.

[0002]

2. Description of the Related Art Problems of conventional environmental pollution caused by industrially generated odors and harmful chemical substances in factories, and odors caused by wastes in service industries such as restaurants and hotels that discharge a large amount of waste. In addition, with the recent increase in amenity-oriented, the problem of indoor environmental pollution due to odors and harmful chemical substances in general living spaces, for example, indoors and cars, has been increasing, and the need for the removal of these harmful substances has been increasing. It is growing rapidly.

[0003] As a method of removing tobacco smoke and various odors generated in a room, ventilation as well as air cleaning such as dust collection and deodorization are particularly effective. However, when ventilation is performed, there is a problem in that warm or cold air or adjusted humidity (moisture) contained in room air is lost.

[0004] On the other hand, a heat conductive, preferably moisture permeable partition plate is superposed on a plurality of layers at predetermined intervals, and formed so that a primary air flow and a secondary air flow alternately pass through each of these layers. A device that ventilates while performing heat exchange by allowing indoor air and outdoor air to pass through such members has been put into practical use. In recent years, the device has been reduced in size and tends to spread to general houses.

[0005] In such a heat exchange device, it is desired to remove harmful microorganisms such as viruses and odors contained in outdoor air, and for example, a technique for adding antiviral properties to the heat exchange element is particularly desirable. Japanese Unexamined Patent Publication No. Hei 7-148407 discloses a technique for deodorizing by using a filter carrying a photocatalyst in combination.
No. 6,086,045.

[0006] Above all, photocatalysts can be regenerated by light,
Since the harmful substance removing effect such as deodorizing property and antibacterial property is perpetuated, heat exchange using a filter carrying the above photocatalyst is particularly preferable, but with the combined use of the filter, air permeability is reduced, or There were problems such as an increase in the size of the device.

[0007]

An object of the present invention is to solve the above-mentioned problems and to provide a photocatalyst member having heat exchangeability, preferably total heat exchangeability, and excellent air cleanliness. It is.

[0008]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, have reached the present invention.

(1) A gas-permeable member formed by laminating a plurality of layers of heat-conductive partition plates at predetermined intervals and forming a primary air flow and a secondary air flow alternately between these layers. A heat-exchangeable photocatalyst member having a photocatalyst carried at the end of the ventilation surface.

(2) In the above invention (1), the photocatalytic member having a total heat exchange property, wherein the partition plate having heat conductivity further has moisture permeability.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION According to the present invention, a heat conductive, preferably moisture permeable partition plate is superposed on a plurality of layers at predetermined intervals, and a primary air flow and a secondary air flow alternately pass between these layers. This is a photocatalyst member in which a photocatalyst is supported at the end of the ventilation surface of the heat exchange type permeable member formed as described above. It has a heat exchange property, preferably a total heat exchange property, and has an excellent air purifying property by the action of a photocatalyst.

The photocatalyst according to the present invention is 0.5 to 5e
V, preferably a photoreactive semiconductor that has a bandgap of 1 to 4 eV and provides a photocatalytic reaction, and exhibits functions such as antibacterial, antiviral, antifungal, deodorizing, and antifouling by irradiating with excitation light. It is a material to do. In particular, its antibacterial properties are excellent, and it not only suppresses the growth of bacteria, but also decomposes toxins generated when bacteria die and detoxifies them, and also decomposes dead bacteria. It is said that it does not deteriorate in a short period of time unlike conventional inorganic antibacterial agents and is permanent.

The photocatalyst according to the present invention includes metal oxide particles such as zinc oxide, tungsten oxide, titanium oxide, and cerium oxide. Among them, titanium oxide is most suitable for use in living space because of its structural stability, ability to remove photoreactive harmful substances, and safety in handling, and zinc oxide is an environment that is not irradiated with excitation light. It also has antimicrobial properties even below, and both are advantageously used as the photocatalyst of the present invention.

The titanium oxide according to the present invention may be a general-purpose titanium dioxide used as a white pigment (provided that the weathering treatment is not completely or partially performed), metatitanic acid, orthotitanic acid, and hydrous titanium oxide. And titanium oxides and hydroxides such as hydrated titanium oxide, titanium hydroxide and titanium peroxide.

Among them, fine particle titanium oxide having a primary particle size of about several tens nm and having an anatase crystal structure is a relatively inexpensive and excellent photocatalyst. However, the titanium oxide according to the present invention is not limited to an anatase crystal structure, and may have a crystal structure such as rutile or brookite or an amorphous titanium oxide as long as it has a photocatalytic ability. .

Examples of the shape of the titanium oxide include a cubic shape, a spherical shape, a true spherical shape, a flaky shape and a nanocluster.

In addition to the above titanium compounds, organic titanates such as titanium alkoxides and titanium chelates may be used, so that a highly uniform and highly transparent photocatalyst layer can be formed.

Pt, Au, Ag, Cu, Pd, Ni, C
o, Fe, Zn, Mo, Ir, Bi, W, Os, Rh,
Compounds such as various metals such as Nb, Zr, Sn, V, Cr, and Ru, and compounds such as ions or oxides thereof may be supported or doped to form a composite.

The photocatalyst according to the present invention may be a microencapsulated photocatalyst coated with a porous substance such as silica or alumina-silica. It is preferable because it is excellent.

The method of supporting the photocatalyst at the end of the ventilation surface includes a method of applying a coating solution containing the photocatalyst using a spray, a brush, or a roll, and a method of attaching the photocatalyst after imparting tackiness to the end of the cell wall. Although not particularly limited, it is preferable to adopt a method that does not block or crush the ventilation hole.

When the photocatalyst is carried at the end of the ventilation surface, it is preferable to carry the adsorbent together, and the photocatalyst and the adsorbent may be mixed and carried. It is particularly preferable to support a photocatalyst on the surface. Examples of the adsorbent according to the present invention include activated carbon, impregnated activated carbon, activated carbon fiber, natural and synthetic zeolites, activated alumina, activated clay, sepiolite, iron compounds such as iron oxide, zinc oxide, magnesium oxide, silica, and silica-oxide. Examples include a zinc composite, a silica-alumina-zinc oxide composite, a composite phyllosilicate, an ion exchange resin, and a mixture thereof.

Among these adsorbents, a substance having a large surface area which is porous is preferable because it sometimes functions as a carrier for the photocatalyst. The adsorbent according to the present invention is mainly composed of physical adsorption, and particularly preferably has an adsorption heat of 46 kJ / mol (11 kcal / mol) or less for an odor substance to be decomposed by a photocatalyst. Regenerated by photocatalyst without saturation.

The adsorbent according to the present invention is preferably an aldehyde adsorbent, and an example of the aldehyde adsorbent is high silica zeolite. The high silica zeolite is chemically a crystal of an aluminosilicate metal salt like a normal zeolite, but particularly has a high ratio of silica to alumina in the crystal, and oxygen atoms in the silica structure have almost no basicity.

Such a high-silica zeolite does not participate in the formation of hydrogen bonds due to the Si—O—Si bond on the surface, exhibits hydrophobicity and does not adsorb water molecules, and thus can be used in a high humidity environment and a high temperature environment. It is also possible to efficiently adsorb aldehydes. Therefore, the high silica zeolite is sometimes called a hydrophobic zeolite.

Further, the high silica zeolite can adsorb not only aldehydes but also a wide range of odorous substances, for example, organic acids, ammonia, amines, ketones, sulfur-containing compounds such as hydrogen sulfide and mercaptans, and indoles. The adsorbent according to the present invention is particularly preferred.

A binder can be used for supporting the photocatalyst according to the present invention. The type of the binder is not particularly limited, and various binders such as a natural polymer such as starch, a modified polymer such as carboxymethyl cellulose, or a synthetic polymer such as polyvinyl alcohol can be used. Thermoplastic polymer emulsions are preferred as binders that provide sufficient adhesion without covering.

As the thermoplastic polymer emulsion, acrylic resins such as polyacrylonitrile and polyacrylate, styrene-acryl copolymer, styrene
Butadiene copolymer, ethylene-vinyl acetate copolymer,
Various copolymer resins such as vinyl chloride-vinyl acetate copolymer and ethylene-vinyl acetate-vinyl chloride copolymer, polypropylene, polyester, phenoxy resin, phenol resin, and butyral resin are exemplified.

The binder used in the present invention has high oxidation resistance and is resistant to photocatalysis, such as a fluororesin or silicon resin antioxidant binder such as polytetrafluoroethylene or a metal oxide. It is preferable to use an inorganic-organic composite binder such as a compound composite thermoplastic polymer emulsion, an inorganic binder, and an appropriate combination thereof. Among them, inorganic binders are preferred.Specific examples include saponite, hectorite, smectite group such as montmorillonite, vermiculite group, kaolinite, kaolinite such as halloysite-serpentine group, and other natural clay minerals such as sepiolite, and colloidal silica. , Colloidal alumina, modified products thereof, and synthetic inorganic polymer compounds.

Next, the partition plate according to the present invention will be described. The partition plate according to the present invention has heat conductivity, and exchanges the sensible heat of the primary airflow and the secondary airflow. Examples of the partition plate having such heat conductivity include a metal plate or a metal foil made of aluminum or stainless steel, or a resin film or paper, especially thin paper and synthetic paper.

The partition plate according to the present invention preferably has moisture permeability in addition to heat transfer, and exchanges latent heat in addition to sensible heat exchange between the primary air flow and the secondary air flow to enable total heat exchange. It is.

Examples of such a heat-conductive and moisture-permeable partition plate include a resin-made moisture-permeable film and a moisture-permeable paper. These moisture-permeable sheets include a net or a nonwoven fabric for the purpose of reinforcement or the like. Such base materials may be laminated. The moisture permeability of the partition plate according to the present invention is such that the moisture permeability measured according to JIS-Z-0208 is 5000 cc / 24 hours.
It is preferably at least m ² .

The partition plate according to the present invention preferably has an appropriate air permeability (non-air permeability) so that the primary air flow and the secondary air flow do not mix, and is Gurley measured according to JIS-P-8117. Air permeability by the method is 100 seconds / 100
cc or more, preferably 500 seconds / 100 cc
More preferably, it is the above.

As a method of stacking the partition plates according to the present invention at predetermined intervals, a method using a corrugated interval plate as disclosed in JP-A-47-19990,
And a method of arranging linear ribs in a row as disclosed in JP-A-61-186795.

As described above, as a method of using the corrugated spacing plate, according to JIS-Z-1516, "corrugated cardboard for exterior use", it is manufactured by using a partition plate for a liner and a spacing plate for a middle lining. Single-sided cardboard can be used, and such single-sided cardboards may be laminated while sequentially intersecting. The angle of intersection is not particularly limited,
They may intersect at other than a right angle, and the intersection angle is preferably 60 ° (or 120 °) to 90 °. The wave shape of the corrugated spacing plate is not particularly limited, and may be a sine wave, a pseudo sine wave, a sea wave, a triangular wave, a square wave, a semicircular or fan-shaped arc or a trapezoidal connected wave. But it is good.

The photocatalyst member of the present invention may contain a deodorant in addition to the above adsorbent. The deodorant used in the present invention is a chemical used mainly for the purpose of removing offensive odor, and specifically, the adsorbents described above, iron ascorbic acid or iron, metal phthalocyanine derivatives such as cobalt or manganese, and the like. Enzymatic deodorants, low-temperature oxidation catalysts such as manganese oxides and perovskite catalysts, synthetic ceramics such as silicon carbide, silicon nitride, calcium silicate, alumina / silica, zirconia, etc. And deodorants using catechins, tannins, flavonoids and the like, which are compounds contained in plant extraction components. If necessary, a plurality of these deodorants may be used in combination, or a hybrid deodorant obtained by combining these deodorants may be used.

The photocatalyst member of the present invention may contain various agents such as an antibacterial agent, an antifungal agent, an antiviral agent, an insect repellent, an insect repellent, an aromatic agent, etc., without departing from the spirit of the present invention. . As such antibacterial agents or antifungal agents, antiviral agents, inorganic antibacterial agents containing silver, zinc or calcium phosphate as main components, organic antibacterial agents such as benzimidazole, isothiazoline, pyrithione, chlorohexidine and the like. And antibacterial agents derived from natural products such as catechin and Meng Song bamboo extract extracted from tea and persimmon, hinokitiol, and hybrid antibacterial agents obtained by combining these.

The site containing various chemicals such as the above-mentioned deodorants and antibacterial agents is not particularly limited.
It is particularly preferable because it can be supported on the surface layer and effectively comes into contact with the airflow. In addition, when the adhesive used for bonding the partition plate and the spacing plate includes a substance that becomes a nutrient such as a microorganism such as starch, the adhesive may include an antibacterial agent, an antifungal agent, or an anti-mite agent. If desired, an insect repellent or the like may be contained.

The photocatalyst member of the present invention may have flame retardancy if necessary. Essentially flame retardant aramid resin, essentially nonflammable metal, glass, oxides such as alumina, etc. Flame retardancy can be imparted by using an inorganic substance as a main component or by adding a flame retardant.

The photocatalyst member of the present invention generally has four ventilation surfaces, that is, an inflow surface and an outflow surface of a primary airflow, and an inflow surface and an outflow surface of a secondary airflow. Any, and a plurality of ventilation surfaces,
In particular, all four ventilation surfaces may be used.

When the photocatalyst member of the present invention is used, for example, in a ventilator for exchanging indoor air and outdoor air, the photocatalyst is carried on the ventilation surface on the outdoor air side to remove harmful substances such as exhaust gas and viruses. It is possible to prevent indoor air pollution, and on the other hand, by carrying a photocatalyst on the ventilation surface on the indoor air side, it is possible to remove household odors such as tobacco odor and cooking odor, thereby reducing outdoor air contamination. It is possible to prevent. In particular, when purifying outdoor air (outside air) sucked indoors, it is preferable to carry a photocatalyst on the vent surface on the outflow side, and when the outside air is humid in summer, for example, water which is an inhibitor of the photocatalytic reaction is removed. Benefits, while
When the outside air is at a low temperature, such as in winter, the temperature rises and approaches room temperature, which has the advantage of promoting the photocatalytic reaction.

As a method for irradiating the photocatalyst member of the present invention with excitation light, a special light source such as a black light, an insect lamp, a health lamp, a germicidal lamp, a high-pressure mercury lamp, a metal halide lamp, and a high-pressure sodium lamp is provided. Although preferred, other than that, it is possible to use irradiation of indoor illumination light such as a fluorescent lamp, and irradiation of sunlight outdoors or near a window. Irradiation may be performed using a light guide plate. Irradiation with photocatalytic excitation light can be continuous or intermittent.

The photocatalyst member of the present invention can be ventilated, and the means for venting is not particularly limited. Examples include sirocco type, axial flow type, propeller type, turbo type, radial type and cross flow type. A method using a fan such as a fan motor, a method using natural wind or a wind generated by an exhaust fan such as a ventilation fan or an air conditioner such as an air conditioner, a method using thermal convection, and a method using an airflow generated by moving a passenger car or the like. And the like. In the ventilation according to the present invention, the air blowing means may be provided only in one of the primary air flow and the secondary air flow, but it is preferable to provide the air blowing means in both of them. In addition, it is preferable that the blowers such as various fan motors are arranged on the inflow side and pressurized for ventilation.

The photocatalyst used in the photocatalyst member of the present invention is excellent in deodorizing, removing harmful substances such as antibacterial or antiviral and has a high air cleaning effect, but is not suitable for removing dust. As long as it does not deviate, dust removing means such as a dust collecting filter or an electric dust collector may be used in combination, and it is preferable to use it on the windward of the photocatalyst and the excitation light source. Dust collection filter, coarse dust filter, medium performance filter, high performance filter, HEPA, ULP
A, electret filters and the like.

[0044]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. However, the present invention is not limited to the embodiment without departing from the spirit of the present invention.

As shown in FIG. 1, a photocatalyst member according to an embodiment of the present invention comprises a partition plate 1 having at least heat conductivity and a plurality of layers laminated at predetermined intervals using a spacing plate 2 or the like. The photocatalyst is carried on the end 5 of the ventilation surface of a gas-permeable member formed so that the airflow 3 and the secondary airflow 4 alternately pass between these layers.

The air-permeable member according to one embodiment of the present invention comprises:
More specifically, in accordance with “corrugated cardboard for exterior” described in JIS-Z-1516, single-faced cardboard produced using a partition plate 1 as a liner and a spacing plate 2 as a middle lining is laminated while sequentially intersecting. Then the top (or bottom)
And a partition plate. The angle of intersection is 90 ° in one embodiment of the present invention, but is not particularly limited to this.

In one embodiment of the present invention, the partition plate 1
Is made of thin paper having a basis weight of 30 g / m ² and a relatively high density, so that it has excellent heat conductivity, and has a moisture permeability of 5000 cc / 24 hours · m ² measured in accordance with JIS-Z-0208.
Due to the above high moisture permeability, total heat exchange is possible between the primary airflow and the secondary airflow.

The end portion 5 of the ventilation surface generally has four surfaces, an inflow surface and an outflow surface of the primary air flow, and an inflow surface and an outflow surface of the secondary air flow. Although it can be applied to any one or more surfaces, in one embodiment of the present invention, the photocatalyst is supported on the outflow surface of the primary airflow.

As shown in FIG. 2, at the end 5 of the ventilation surface, the coating layer 6 containing the photocatalyst is composed of one end of the partition plate 1 and the spacing plate 2a constituting one airflow vent, and the other end. It is mainly carried on the side surface of the partition plate 2b constituting the airflow vent.

The photocatalyst carried at the end of the ventilation surface directly and relatively strongly receives the excitation light emitted from the ultraviolet lamp 7, so that extremely high photocatalytic performance can be obtained.
Excellent air cleanliness such as deodorant and antibacterial properties.

As a comparative example, when a heat exchange element and a photocatalyst filter according to the prior art are used in combination, the air permeability of the photocatalyst filter is reduced in order to improve the light receiving performance of the photocatalyst, and conversely, the air permeability is to be ensured. Then, there was a problem that the light receiving property of the photocatalytic filter was reduced. On the other hand, the photocatalyst member of the present invention has high light-receiving properties, excellent air cleanliness, and excellent air permeability as described above.

The coating layer 6 containing a photocatalyst contains titanium oxide as a photocatalyst and high silica zeolite as an adsorbent, and has a particularly excellent deodorizing property. It is effective for removing species. In addition, when the adsorbent is supported in combination as described above, the irradiation of the ultraviolet lamp 7 can be intermittently regenerated without intermittent irradiation, so that energy related to generation of excitation light can be saved. In addition, it is particularly preferable because sunlight irradiation can be used without using an ultraviolet lamp.

[0053]

According to the present invention, it is possible to obtain a photocatalyst member capable of performing heat exchange (sensible heat exchange) or total heat exchange between a primary airflow and a secondary airflow and having excellent air cleanliness. Such a photocatalyst member of the present invention can be used, for example, as a heat exchange element of a heat exchange type ventilator, but can remove harmful substances from intake air into a room and is included in exhaust air from a room. It is particularly useful for ventilation for the purpose of cleaning the air, since it is possible to remove contaminants that are generated.

[Brief description of the drawings]

FIG. 1 is a perspective view showing one embodiment of a photocatalyst member of the present invention.

FIG. 2 is a partially enlarged cross-sectional view showing one embodiment of a state where a photocatalyst is supported at an end of a ventilation surface of the photocatalyst member of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 partition plate 2 spacing plate 3 arrow indicating the direction of primary air flow 4 arrow indicating the direction of secondary air flow 5 end of ventilation surface 6 coating layer containing photocatalyst 7 ultraviolet lamp

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) B01J 35/04 311 B01D 53/36 JHF Term (Reference) 4C080 AA07 BB02 CC01 HH05 JJ06 KK08 LL02 MM02 QQ20 4D048 AA22 AB01 AB03 BA07X BA41X BB02 BB08 CA06 CC21 CC29 CC36 EA01 4G069 AA01 AA04 AA11 BA04B BA17 BA22B BA29B BA48A BB04B CA01 CA07 CA10 CA17 DA06 EA03X EA21 EE04 EE07 FA02 FA06

Claims (2)

[Claims] An air-permeable member formed by laminating partition plates having heat conductivity on a plurality of layers at predetermined intervals and forming a primary air flow and a secondary air flow so as to alternately pass between these layers. A photocatalyst member having a photocatalyst carried at an end of a ventilation surface. 2. The photocatalyst member according to claim 1, wherein the heat conductive partition plate further has moisture permeability.