JP2000107270A - Antimicrobial and deodorant filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an antimicrobial and deodorant filter which is capable of highly and surely exhibiting antimicrobial and deodorant effects and allows easy maintenance. SOLUTION: A sheet 1 constituting the filters 10 and 12 consist of many irregular fibers 3, 3 and so forth which constitute paper 2 and are entangled with each other, ordinary photocatalyst type TiO2 particulates 4, another photocatalyst type TiO2 particulates 6 and adsorbents 5 which are embedded and held among these fibers. The photocatalyst type TiO2 particulates 4 are <=20 nm in size and the another photocatalyst type TiO2 patriculates 6 are also <=20 nm in size and are formed by dispersing and adhering many extremely fine antimicrobial metals 8, such as Ag (silver), to their surfaces. The TiO2 particulates 6 are embedded in a range of 0.1 to 50 wt.% in the entire part of the sheet 1 (the paper 2). Odorous materials are adsorbed by the particulates 4 via the adsorbents 5 and the bacteria are killed by the antimicrobial metals 8 on the surface of the particulates 6 via the adsorbents 5, by which the antimicrobial treatment is executed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antibacterial / deodorizing filter which is disposed in, for example, an air conditioning system and performs sterilization and deodorization in supplied air.

[0002]

2. Description of the Related Art In recent years, deodorizing products using activated carbon, deodorizing products having an antibacterial function using silver particles, or antibacterial products have been widely used due to improvement in hygiene awareness. Generally, a filter using activated carbon is used, but it mainly removes odorous substances and has no sterilizing effect. on the other hand,
Air conditioning equipment in hospitals, etc.
There is a demand for a filter having excellent antibacterial properties. In addition, a filter having antibacterial properties is also required for a circulation path for circulating cool air inside a refrigerator car or a large refrigerator.

[0003] Accordingly, antimicrobial metal particles such as silver having a mean particle size of 0.01 to 0.5 µm are dispersed and attached to the surface of ceramic particles or base metal particles in an amount of 0.1 to 60% by weight based on their weight. A resin product or a fiber product in which a powdery metallic antibacterial material is buried in a state where a part thereof is exposed has been proposed (see JP-A-8-99812). However, the above antibacterial fiber products are also applied only to clothes, sheets, packaging sheets, and the like.

Recently, it has been studied to apply photocatalytic (anatase) type TiO ₂ fine particles having a particle size of 10 nm or less to a deodorizing filter. When the photocatalytic TiO ₂ microparticles are irradiated with a fluorescent lamp having a certain illuminance or higher, the surface is activated, and hydroxyl radicals are generated from moisture in the atmosphere, which is considered to oxidize and decompose odorous substances. .
On the other hand, it is said that the hydroxyl radical is sterilized, but the effect is not so great because it needs to be brought into contact with TiO ₂ .

[0005]

[SUMMARY OF THE INVENTION to be solved] The present invention is to solve the problems in the above prior art, by utilizing the photocatalytic TiO ₂ particles, with may increase and reliably exhibit the antibacterial and deodorizing properties, maintenance It is another object of the present invention to provide an antibacterial / deodorizing filter that is easy to use.

[0006]

Means for Solving the Problems As a result of intensive studies made by the inventors, the present invention has focused on the fact that by dispersing and attaching an antibacterial metal to photocatalytic TiO ₂ , both antibacterial properties and deodorization are exhibited. It was made. That is, the antibacterial-deodorizing filter of the present invention, the antibacterial metal photocatalytic TiO ₂ particles dispersed attached to the surface embedded in the sheet, characterized in that. According to this, a number of poles small antimicrobial metal bacteria adhered to a sheet of paper or the like constituting the filter, together with obtaining excellent antimicrobial action can be surely sterilized, also deodorization effect by photocatalytic TiO ₂ particles Obtainable.

Further, the photocatalytic TiO ₂ particles dispersed attaching an antibacterial metal on the surface, embedded in a sheet mixed with an ordinary photocatalytic TiO ₂ particles, it is also included antibacterial and deodorizing filter. According to this, exclusively the normal adsorption and decompose odorous substances photocatalytic TiO ₂ particles by dispersing function and photocatalytic TiO ₂ particles to sterilizing bacterial the surface together with the same deodorizing, reliable and The filter has a stable antibacterial and deodorizing effect.

Further, the TiO ₂ fine particles having the antibacterial metal dispersed and adhered to the surface thereof are used in an amount of 0.1 to 5% with respect to the whole filter.
An antibacterial / deodorizing filter containing 0 wt% and each of the fine particles having a size of 20 nm or less is also included. According to this, it can be easily buried in the filter, and the antibacterial and deodorizing effects can be exhibited more reliably and reliably. When the content of the fine particles is less than 0.1% by weight, the antibacterial property becomes insufficient. On the other hand, when the content exceeds 50% by weight, the antibacterial effect is saturated and the cost is increased.

Further, the antibacterial metal is Ag or Cu or an alloy based on either of them, and 0.001 to 5.0% by weight of the whole filter is contained. An antibacterial / deodorizing filter having a thickness of 10 nm to 10 nm is also included. According to this, a sterilizing / antibacterial effect can be exhibited with high and certainty. When the content of the antibacterial metal is less than 0.001 wt%, the bactericidal effect becomes insufficient. On the other hand, when the content exceeds 5.0 wt%, the bactericidal effect becomes saturated and the cost becomes high. Range. In addition, the size may be in a range that can be attached to the surface of the fine particles.

Further, as an adsorbent, at least one of activated carbon, impregnated carbon, activated carbon fiber, zeolite, sepiolite, silica gel or zinc oxide is added in an amount of 5 wt% or more.
Also includes antibacterial and deodorizing filters. According to this, the deodorizing and antibacterial effects can be more and more reliably exerted. That is, once adsorbs organic substances underlying bacteria and odor by them photocatalytic TiO ₂ particles with a conventional photocatalytic TiO ₂ particles and antimicrobial metal is dispersed adhere to the surface, decomposition and sterilization at the adsorbent The deodorizing and antibacterial effects can be ensured.

Further, photocatalytic TiO ₂ fine particles having the antibacterial metal dispersed and adhered to the surface thereof, and ordinary photocatalytic TiO ₂
An antibacterial / deodorizing filter having a total amount of not more than 70% by weight of fine particles is also included. According to this, a filter having a sheet capable of stably exhibiting the deodorizing and antibacterial effects can be obtained. If the total amount exceeds 70% by weight, the strength of the sheet starts to decrease and the cost increases, so this range is excluded. In addition, an antibacterial and deodorizing filter, wherein the sheet is any of paper, nonwoven fabric, or fabric, is included. According to this, it is possible to entangle and hold each fine particle with an irregular fiber group such as paper, or it is possible to obtain a filter in which cloth is uniformly dispersed and held in a cloth material via an adhesive or the like.
In addition, as described later, this sheet may be formed into a filter having a corrugated or honeycomb core shape and a vent passage evenly opened.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. FIGS. 1 (A) and (B)
It is a front view of the antibacterial and deodorizing filters 10 and 12 of the present invention. The filter 10 is formed by alternately laminating and adhering sheets 1 folded in a corrugated (wave) shape and flat sheets 1, and has a large number of ventilation paths 11 in the depth direction as shown in the figure. Further, the filter 12 is formed by laminating and adhering the sheets 1 folded into a waveform formed of a number of horizontal portions and an oblique portion connecting them in a honeycomb shape vertically, and as shown in FIG. Road 13 is established. As shown in the drawing, both filters 10 and 12 have a cross-sectional structure with little resistance to the blowing of the air to be sterilized and deodorized, so that there is almost no pressure loss in the blowing. Incidentally, the ventilation paths 11 and 13 are less than 1 cm ² , the total aperture ratio is about 85 to 90%, and the length in the depth direction is about 1 to 2 cm.

FIG. 1C schematically shows an enlarged cross section of the sheet 1 constituting the filters 10 and 12. Sheet 1
Are composed of a large number of intertwined irregular paper fibers 3 constituting the paper 2, ordinary photocatalytic TiO ₂ fine particles 4 embedded and held therebetween, an adsorbent 5, another photocatalyst Type TiO ₂ fine particles 6. Ordinary photocatalytic TiO ₂
The fine particles 4 have a size of 20 nm or less. Another photocatalytic TiO ₂ fine particle 6 also has a size of 20 nm.
In the following, antimicrobial metal 8 such as Ag (silver)
Are dispersed and attached. These TiO ₂ fine particles 6
Is embedded in the range of 0.1 to 50% by weight with respect to the entire filters 10 and 12. Incidentally, the photocatalytic (anatase) type TiO ₂ is
One of the crystal systems formed by the manufacturing method, which is a low-temperature type that reacts and activates with light from a fluorescent lamp or the like, and is distinguished from another high-temperature type (rutile) or the like. The adsorbent 5 is added in an amount of 5 wt% or more. This is because if it is less than 5 wt%, the adsorption effect becomes insufficient.

FIG. 2 relates to a method of manufacturing the paper (sheet) 2 constituting the filters 10 and 12. FIG. 2A shows the water tank 1.
4 and a large number of paper fibers 3, 3... And an adhesive component such as starch are previously dissolved in water W.
The step of charging the O ₂ fine particles 4, the photocatalytic TiO ₂ fine particles 6 with the antibacterial metal 8 dispersed and attached thereto, and the adsorbent 5 is shown.
At this time, the input amount of the fine particles 6 is adjusted with respect to the paper fibers 3, 3,. After the introduction of the fine particles 4, 6 and the adsorbent 5, the water W is stirred for a predetermined time.

Next, as shown in FIG.
The strainer 15 into the water W. This machine 15
The screen 18 is made up of four frames 16 and a mesh screen 18 stretched between the frames. The screen 18 is made substantially horizontal, and the whole squeezer 15 is swung in a horizontal direction so as to draw a gentle arc. After a lapse of a predetermined time, the strainer 15 is taken out of the water W, drained, and dried. As a result, as shown in FIG. 1C, two types of photocatalyst T
Paper (sheet 1) 2 in which iO ₂ fine particles 4, 6 are embedded and held can be obtained. The photocatalytic TiO ₂ fine particles 4, 6
The total amount of the filter including the paper 2 is set to 70% by weight or less to maintain strength and reduce costs. Further, in order to obtain the strength of the paper 2, it is necessary that at least 10 wt% or more of the paper fiber 3 is contained therein.

According to the filters 10 and 12 formed using the paper (sheet 1) 2, bacteria and odorous substances contained in the passing air are buried in the paper 2 from the paper fiber 3 itself of the paper 2. The adsorbent 5 is positively adsorbed. In addition, the adsorbed bacteria are surely sterilized by the antibacterial metal 8 of the fine particles 6 located in the immediate vicinity. That is, since the antibacterial metal 8 has a very small size of several to 10 nm even if the absolute amount is small, the surface area is significantly increased, and a small amount of metal ions which are said to have an antibacterial effect are eluted. So
It can be easily sterilized. On the other hand, odor substances are adsorbed by the fine particles 4. Therefore, the air that has passed through the ventilation passages 11 and 13 of the filters 10 and 12 is more reliably subjected to antibacterial and deodorizing treatment than in the state before the passage. In addition, since each of the fine particles 4 and 6 can be activated only by irradiating light such as a fluorescent lamp, a stable antibacterial and deodorizing effect can be maintained for a long time, and maintenance is reduced. Has advantages.

[0017]

EXAMPLES Specific examples of the present invention will be described below together with comparative examples. 5 cm × 5 in which each of the fine particles 4 and 6 shown in Table 1 was embedded using the adsorbent 5 shown in the same table.
Examples 1 to 4 comprising paper 2 having a thickness of 0.3 mm and a thickness of 0.3 mm, Comparative Example 1 of paper 2 of the same size having nothing embedded therein, and Comparative Example 2 comprising only ordinary photocatalytic TiO ₂ fine particles 4 embedded therein Prepared. The percentage of Ag, which is the antibacterial metal 8, is the ratio to the fine particles 6 to which it is attached. Therefore, Examples 1 to
Ag content in paper 2 of No. 4 was 0.003 w each.
t%, 0.006 wt%, 0.032 wt%, 0.9 wt%. Two sheets of paper 2 of each example were separately placed in a Petri dish, and the bacterial solution was dropped on the surface. This bacterial solution contains the initial number of E. coli shown in Table 1 per ml. In this state, each petri dish was kept at 30 ° C. for 24 hours. At this time, 30
It was held separately under a 00-lux fluorescent light box and in a dark room. Then, the paper 2 of each example was taken out from the Petri dish, Escherichia coli was washed out with 10 ml of physiological saline phosphate, and the viable cell count was measured. Table 1 shows the results.

[0018]

[Table 1]

The results in Table 1 show that in Examples 1 to 4, the viable cell count was drastically reduced under fluorescent light and in a dark place.
The viable cell count increased in any place, and in Comparative Example 2, the viable cell count decreased slightly under a fluorescent light, but did not disappear, and increased remarkably in a dark place. From these results, it was confirmed that all of Examples 1 to 4 had remarkable antibacterial properties, and that no difference was observed between a fluorescent light and a dark place. Therefore, Table 2
In Examples 5 to 8 and Comparative Examples 3 and 4 of the same paper 2 in which the fine particles 4 and 6 shown in FIG. Then, after placing each paper 2 in a petri dish and dripping the bacterial solution in the same manner as described above, the paper 2 is held under the same conditions as under the fluorescent lamp,
The viable cell count was measured in the same manner as described above every 1, 2, and 3 hours. Table 2 shows the results.

[0020]

[Table 2]

The results in Table 2 show that in Examples 5 to 8, the more the fine particles 6 of the photocatalytic TiO ₂ having 3% of Ag (8) dispersed and adhered to the surface, the more quickly and clearly the antibacterial property was exhibited. . On the other hand, in Comparative Examples 3 and 4, rutile (non-photocatalyst) type TiO ₂ fine particles 6 in which 5% of Ag (8) was dispersed and adhered to the surface were buried. In Comparative Example 4, the viable cell count was rather increased. From these results, in Examples 5 to 8, it is understood that the fine particles 6 activated by irradiation with a fluorescent lamp significantly promoted the bactericidal action of Ag (8) on the surface, and the present invention (claims) The effect of 1) was also supported.

Next, the deodorizing performance was measured. FIG. 3 shows the deodorizing performance measuring device 20 used for this. This device 2
No. 0 inserts the petri dish 30 into the separable flask 21 via the tripod 28. In the Petri dish 30, the papers 2 of Examples 1 to 4 and Comparative example 1 shown in Table 1 are individually contained in advance. The flask 21 is closed with a lid 22, and the two are brought into close contact with a ring-shaped clip 23. In this state,
First, a vacuum pump (not shown) is driven to evacuate the exhaust pipe 26, and pure air is separately supplied from the intake pipe 25 to the flask 2.
Introduce into 1. By repeating this operation three times, the valve 24
Close.

Next, a malodorous gas (trimethylamine / concentration: 4940 ppm) is injected into the flask 21 from the sampling port 27 by an amount corresponding to a predetermined concentration. Further, the flask 21
Is turned on, and the paper 2 in the petri dish 30 is irradiated with ultraviolet rays ( ² mW / cm ² ) for 90 minutes. In the meantime, every 15 minutes or 30
The above-mentioned odor gas concentration in the flask 21 was measured every minute using a dedicated gas detector tube. The results are shown in the graph of FIG. From FIG. 4, in Examples 1 to 4 and Comparative Examples 1 and 2, both dropped sharply at first, but with the passage of time, Examples 1 to 4
No. 4 clearly showed a decreasing tendency. On the other hand, in Comparative Example 1, almost no decrease was observed after 15 minutes. Further, Comparative Example 2 was slightly lower than Examples 1 to 3, and the photocatalytic TiO ₂
The effect of the fine particles 4 appeared.

This was initially reduced by dilution of the offensive odor gas itself in each case, but from around 15 minutes, Examples 1-4 were reduced.
In this case, the odorous gas was adsorbed and decomposed on the surface by the action of the photocatalytic TiO ₂ fine particles 4, so that the deodorizing effect was maintained.
On the other hand, in Comparative Example 1, the odorous gas was not reduced so much by the paper 2, so it is considered that the odorous gas did not decrease from the middle. From these results, the deodorizing effect of the present invention (claim 2) was also confirmed. In addition, the deodorizing performance of Examples 1 to 4 and Comparative Examples 1 and 2 was similarly measured using acetaldehyde and methyl mercaptan as the malodorous gas, respectively.
In each case, the result was similar to the graph of FIG.

The present invention is not limited to the embodiments and examples described above. For example, as shown in Example 8 in Table 2, it is apparent that only the photocatalytic TiO ₂ fine particles 6 having Ag (8) dispersed and adhered to the surface may be embedded in the paper 2. Further, the sheets of Examples 1 to 8 may be made of a foamed resin sheet, and may be a filter in which fine activated carbon is also embedded. Further, a filter can be formed from a sheet sewn with a large number of the fine particles 4 and 6 sandwiched between two cloths. It is also possible to form a sheet of paper or the like into a corrugated shape and form a cylindrical filter in which the sheet is spirally wound. In addition to the above, the filter of the present invention can be used in air-conditioning equipment for a room requiring a severe indoor environment such as a clean room, a computer room, and a precision measurement room, or in various processes for obtaining clean air or gas. Can also be used.

[0026]

According to the antibacterial / deodorizing filter of the present invention described above, the photocatalytic TiO ₂ fine particles activate the antibacterial metal dispersed and adhered to the surface thereof, thereby exhibiting a reliable antibacterial / deodorizing effect. Therefore, it is only necessary to expose to a fluorescent lamp or the like, so that maintenance is small and stable performance can be maintained. Further, it also exhibits a reliable and stable antibacterial and deodorizing effect by conventional photocatalytic TiO ₂ particles and the antibacterial and deodorizing filters embedded in a mixed and photocatalytic TiO ₂ particles dispersed adhering an antibacterial metal to the surface Can be.

[Brief description of the drawings]

1 (A) and 1 (B) are front views showing embodiments of filters of the present invention, and FIG. 1 (C) is a sheet constituting these filters.
Sectional drawing which expanded the (paper) typically.

FIGS. 2A and 2B are schematic views showing respective manufacturing steps for obtaining a sheet (paper) of FIG. 1;

FIG. 3 is a schematic view of an apparatus used for measuring the deodorizing performance of the sheets of Examples and Comparative Examples of the present invention.

FIG. 4 is a graph showing the deodorizing performance of each sheet of an example of the present invention and a comparative example.

[Explanation of symbols]

1 ............... sheet 2 ............... paper 4,6 ......... photocatalyst-type TiO ₂ fine particles 5 ............... adsorbent 8 ............... Ag (antibacterial metal) 10 and 12 ... filter

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Kazuo Yanagihara 1-10-14 Tatsumi Minami, Okazaki City, Aichi Prefecture (72) Inventor Toshihiro Takehana 3-10 Fukuura, Kanazawa-ku, Yokohama-shi, Kanagawa Prefecture, Japan Incorporated Company (72) Inventor Kenji Murakami 3-10 Fukuura, Kanazawa-ku, Yokohama-shi, Kanagawa Japan F-term (reference) 4C080 AA05 AA07 BB02 BB05 CC02 CC05 CC09 CC12 HH05 JJ05 JJ06 JJ09 LL10 MM02 MM04 MM05 MM06 MM07 NN22 NN20 4CB03 CF10 CG03 CG04 CH05 CK10 4D019 AA01 BA03 BA05 BA07 BA12 BA13 BB03 BC06 BC07 BC10 4D048 AA22 BA07X BA13X BA34X BA35Y BA41X BB01 BB02 BB04 CA06 CC40 CD01 EA01 EA04 EA10

Claims (7)

[Claims] 1. A photocatalyst is dispersed attaching an antibacterial metal on a surface-type TiO ₂ particles embedded in the sheet, the antibacterial and deodorizing filter characterized in that it. Wherein the antimicrobial metal to photocatalytic TiO ₂ particles dispersed deposited on the surface, embedded in a sheet mixed with an ordinary photocatalytic TiO ₂ particles, the antibacterial and deodorizing filter characterized in that it. 3. The T in which the antibacterial metal is dispersed and attached to the surface.
iO ₂ particles, contains 0.1-50% relative to the entire filter, and the antibacterial and deodorizing filter according to claim 1 or 2 size of each particle is 20nm or less, wherein the. 4. The antibacterial metal is Ag or Cu or an alloy based on either of them, 0.001 to 5.0% by weight of the whole filter, and the size of each metal is a few. The antibacterial / deodorizing filter according to any one of claims 1 to 3, wherein the thickness is 10 nm to 10 nm. 5. The method according to claim 1, wherein at least one of activated carbon, impregnated carbon, activated carbon fiber, zeolite, sepiolite, silica gel, and zinc oxide is added as an adsorbent in an amount of 5 wt% or more. The antibacterial / deodorizing filter according to any one of the above. 6. The total amount of the photocatalytic TiO ₂ particles dispersed attaching the antimicrobial metal to the surface, the conventional photocatalytic TiO ₂ particles, claim or less 70 wt%, it is characterized by 2 6. The antibacterial / deodorizing filter according to any one of claims 1 to 5. 7. The antibacterial and deodorizing filter according to claim 1, wherein the sheet is any one of paper, nonwoven fabric, and fabric.