WO2011142266A1

WO2011142266A1 - Drinking water server

Info

Publication number: WO2011142266A1
Application number: PCT/JP2011/060288
Authority: WO
Inventors: 健太郎石鍋; 和正守本
Original assignee: エア・ウォーター株式会社
Priority date: 2010-05-10
Filing date: 2011-04-27
Publication date: 2011-11-17
Also published as: KR20130059315A; TW201143870A; CN102781814A; KR101757500B1; JP5904717B2; TWI527618B; JP2011255960A; CN102781814B

Abstract

Provided is a drinking water server whereby, using a simple structure, bacterial invasion with the introduction of outside air can be prevented and bacterial proliferation within the drinking water server can be inhibited. The drinking water server is provided with an air filter (1) for introducing outside air, which comprises a porous film being formed of a fluororesin and having a pore diameter of 0.2-0.8 µm, and protective porous films fixed to both faces of the aforesaid porous film. In the drinking water server, moreover, an antibacterial member (2), which comprises multiple antibacterial particles comprising a low-density polyethylene and an ion exchanger, wherein silver ions are ionically bound to zeolite, said multiple antibacterial particles being sealed in a water-permeable porous bag, is placed in a tank.

Description

Drinking water server

The present invention relates to a drinking water server that can collect water from a container containing drinking water that can be exchanged into a glass or the like, and that can prevent the invasion of bacteria and suppress the propagation of bacteria. is there.

Conventionally, a drinking water server has been used in the workplace or the like that can replace a container containing drinking water and collect a necessary amount of drinking water from the container into a cup or the like when necessary. In general, a hard type (gallon bottle type) that does not deform is used as the drinking water container.

For example, as shown in FIG. 8, this type of drinking water server is provided with a container connecting portion 11 that removably connects the mouth portion of the drinking water-containing container B at the top, and below the container connecting portion 11. A cold water tank 12 and a hot water tank 13 for storing drinking water dropped from the container B are provided, and a cold water faucet (four set) 14a for collecting the drinking water stored in the

tanks

12 and 13, respectively. A hot water side faucet (four set) 14b is provided (in FIG. 8, the hot water side faucet 14b is hidden behind the cold water side faucet 14a). In addition, an outside air intake 15 that communicates with the inside of the container B containing drinking water via the container connection portion 11 is provided, and an air filter 16 is provided in a state of covering the outside air intake 15.

The container connecting portion 11 is formed in a double cylinder shape, the outer side is formed in a bottomed cylindrical fitting cylindrical body 11a into which the mouth of the container B is fitted, and the inner side is formed in the above-described manner. It is formed in the cylindrical body 11b for insertion which is inserted in the mouth part of the container B. A through-hole 11c for air circulation and a through-hole 11d for circulation of drinking water are formed in the peripheral wall of the inner cylindrical body 11b, and an opening 11e is formed on the bottom surface. The hot water tank 13 is a watertight sealed tank, is disposed below the cold water tank 12, and the bottom of the cold water tank 12 communicates with the inside of the hot water tank 13 through a communication pipe 17. The cold water tank 12 is a tank with an open ceiling, and a through hole is formed in the center of the cold water tank 12 in the height direction and integrated with the relay pipe 19. A circular plate-shaped separator 18 is disposed in a state where a gap is formed between the peripheral wall of the cold water tank 12. The through hole at the center of the separator 18 and the connecting pipe 17 are connected by a relay pipe 19. A cooling pipe 12 a is wound around the outer surface of the peripheral side wall of the cold water tank 12, and a heater 13 a is wound around the outer surface of the peripheral wall of the hot water tank 13.

The drinking water server is used as follows. That is, first, the mouth part of the container B with the drinking water is connected to the container connection part 11 provided at the upper part of the drinking water server, and the container B with the drinking water is attached to the upper part of the drinking water server. Then, air enters the container B from the opening 11e on the bottom surface of the insertion cylindrical body 11b of the container connection part 11 through the air circulation through hole 11c, and the drinking water in the container B flows. The container connecting portion 11 drops from the drinking water circulation through hole 11d of the insertion tubular body 11b through the opening 11e on the bottom surface. The dropped drinking water first enters the hot water tank 13 and the cold water tank 12 through the through hole of the separator 18 and the gap between the separator 18 and the peripheral side wall of the cold water tank 12. Thereby, drinking water is stored in the cold water tank 12, and the surface of the drinking water rises. And if the water surface passes the separator 18 and reaches the bottom face of the container connection part 11, the opening part 11e of the bottom face is closed, and the fall of the drinking water from the said container B is stopped. Next, in this state, drinking water is collected from the cold water side faucet 14a or the hot water side faucet 14b. Then, the surface of the drinking water on the separator 18 descends and the plugging by the surface is released. For this reason, in the same manner as described above, air enters the container B from the container connecting portion 11 and drinking water falls from the mouth of the container B. Next, water sampling from the

faucets

14a and 14b is stopped. Then, the surface of the drinking water rises on the separator 18, and when the water surface reaches the bottom surface of the container connecting portion 11, the opening 11e on the bottom surface is closed again to stop the drinking water from dropping. In this manner, drinking water can be collected from the container B by the drinking water server.

Here, the air entering the container B is taken only through the air filter 16 from the outside of the drinking water server. At that time, the air filter 16 prevents dust and the like from entering the drinking water server from the outside. As the air filter 16, a non-woven fabric, sponge, or the like that has a rough eye (increases the hole diameter) and improves air permeability is used. If a finer one is used, the air permeability is deteriorated and sufficient air (outside air) cannot be taken into the container B, so that the drinking water cannot be properly dropped from the container B, and the

faucets

14a and 14b. This is because the water collection in the water deteriorates.

However, when the outside air is taken in through a coarse material such as a non-woven fabric or sponge, the entry of relatively large items such as dust can be prevented, but the entry of relatively small items such as bacteria cannot be sufficiently prevented. Further, bacteria may not only enter through the air filter 16 but also enter from the

faucets

14a and 14b when the hands or fingers touch the

faucets

14a and 14b. If water is collected frequently, the drinking water will move in the drinking water server, so it is difficult for the bacteria that have invaded to breed. There is no movement in the drinking water, and bacteria are easy to propagate.

Therefore, in order to sterilize the bacteria, a drinking water server provided with a heating device (see, for example, Patent Documents 1 and 2), a drinking water server provided with an ultraviolet lamp (see, for example, Patent Document 3), an ozone generator. A drinking water server (see, for example, Patent Document 4), a drinking water server (see, for example, Patent Document 5) that includes a plasma ion generator and another sterilization device, and the like have been proposed.

JP 2006-076662 A JP 2009-038771 A JP 2009-083868 A Japanese Patent No. 4317259 Utility Model Registration No. 3110564

However, the drinking water server provided with the heating device has a problem that the piping system becomes extremely complicated and the drinking water server itself is not only expensive, but also increases the power consumption and the running cost. There is a problem that the drinking water server cannot be used while is operating. Moreover, the drinking water server provided with the ultraviolet lamp has a problem that ultraviolet rays are harmful to a human body and an eyeball, a problem that ultraviolet rays deteriorate resin parts and rubber parts in the drinking water server, and the like. Moreover, the drinking water server provided with the ozone generator has a problem that ozone gas concentration is restricted because ozone gas is not useful for the human body, a problem that there is an unpleasant odor peculiar to ozone, and the flavor of drinking water is impaired. Moreover, since the drinking water server provided with the plasma ion generator and other sterilizers operates several sterilizers simultaneously, there exists a problem that energy consumption becomes large, and a problem that an apparatus becomes very complicated.

The present invention has been made in view of such circumstances, and has a simple structure that prevents invasion of bacteria accompanying intake of outside air and can suppress the propagation of bacteria in the drinking water server. The purpose is to provide a water server.

In order to achieve the above object, a drinking water server according to the present invention includes a container connecting portion that removably connects a mouth portion of a container with drinking water, and a beverage that is provided below the container connecting portion and has dropped from the container. A tank that stores water, a faucet that collects drinking water stored in the tank, an outside air intake port that communicates with the inside of the container containing drinking water via the container connection portion, and the outside air intake port. A drinking water server provided with an air filter provided in a state where the air filter is an air filter of (A) below, and an antibacterial member of (B) below is installed in the tank. It takes the composition that it is.
(A) a fluororesin porous membrane and a protective porous membrane fixed on both front and back surfaces of the fluororesin porous membrane, and the pore diameter of the fluororesin porous membrane is in the range of 0.2 to 0.8 μm And an air filter in which the pore diameter of the protective porous membrane is set to be equal to or larger than the pore diameter of the fluororesin porous membrane.
(B) It consists of a plurality of granular antibacterial agents and a water-permeable porous bag in which these granular antibacterial agents are sealed, and the granular antibacterial agent comprises low density polyethylene and an ion exchanger in which silver ions are ion-bonded to zeolite. An antibacterial member.

In order to realize sanitary management in a drinking water server with a simple structure, the present inventors do not adopt a conventional means for sterilizing invading bacteria in the drinking water server, but bacteria accompanying intake of outside air. A means for preventing the invasion of bacteria and a means for suppressing the propagation of bacteria due to bacteria entering the drinking water server from the faucet by touching the faucet with a human hand or finger. Inspired by adoption.

Therefore, the present inventors first conducted research on the air filter forming material and structure in order to prevent the invasion of bacteria accompanying the intake of outside air. In the process, when a fluororesin is used as a forming material, it was found that a porous film having excellent air permeability can be produced even if the pore diameter is reduced. And since fluororesin is excellent in water resistance, it is suitable for the drinking water server which uses water. Furthermore, in order to protect the fluororesin porous membrane and maintain the filter performance, the inventors conceived of fixing protective porous membranes on both sides of the fluororesin porous membrane. And based on this idea, further research was repeated. As a result, in the air filter in which the protective porous membrane is fixed on both surfaces of the fluororesin porous membrane, the pore diameter of the fluororesin porous membrane is set within the range of 0.2 to 0.8 μm, When the pore size of the protective porous membrane is set to be equal to or larger than the pore size of the fluororesin porous membrane, it is possible to prevent the invasion of bacteria due to the intake of outside air while ensuring sufficient air permeability and maintaining water collection over a long period of time. I found out.

Food poisoning bacteria and the like are smaller than the pore diameter of 0.2 to 0.8 μm of the fluororesin porous membrane, but the action of static electricity and inertial collision and Brownian motion during the penetration of the fluororesin porous membrane such as food poisoning bacteria. From this effect, it can be assumed that it does not permeate the fluororesin porous membrane.

Next, the present inventors conceived of installing an antibacterial member in the tank of the drinking water server in order to suppress the growth of bacteria in the drinking water server, and the formation material and structure of the antibacterial member Repeated research. As a result, the antibacterial member is composed of a plurality of granular antibacterial agents and a water-permeable porous bag in which these granular antibacterial agents are sealed. The granular antibacterial agent is ion-bonded with low density polyethylene and zeolite with silver ions. It was found that the granular antibacterial agent released the silver ions into water, and the growth of bacteria in the drinking water server could be suppressed by the action of the silver ions. Moreover, it was also found that the granular antibacterial agent does not adversely affect the human body.

That is, the present inventors adopt the specific air filter as the air filter of the drinking water server, and install the specific antibacterial member in the tank of the drinking water server, thereby allowing the outside air to have a simple structure. The present inventors have found that it is possible to prevent the invasion of bacteria accompanying the incorporation and to suppress the propagation of bacteria in the drinking water server, and have reached the present invention.

Since the drinking water server of the present invention is adapted to take in outside air through the air filter of (A) above, it is possible to prevent bacteria from entering due to taking in outside air. Furthermore, since the antibacterial member of (B) is installed in the tank, even if bacteria enter from the faucet, their propagation can be suppressed. And the hygiene management by the air filter of said (A) and the antibacterial member of said (B) can be implement | achieved by a simple structure unlike complicated sterilizers, such as a heating apparatus in the conventional drinking water server. Therefore, there are advantages that maintenance is easy and power is not used for hygiene management.

In particular, in the air filter (A), the thickness of the fluororesin porous membrane is set in the range of 1 to 15 μm, and the thickness of the protective porous membrane is set in the range of 120 to 170 μm. In addition, the balance between the ventilation performance and the bacteria invasion prevention performance of the air filter can be further optimized.

In the antibacterial member (B), the ratio of the low density polyethylene and the ion exchanger (low density polyethylene / ion exchanger) constituting the granular antibacterial agent is (70% by weight / 30% by weight) to (95%). Wt% / 5 wt%), the average diameter of the granular antibacterial agent is set in the range of 3-10 mm, the pore diameter of the water-permeable porous bag is set in the range of 50-100 μm, When the volume ratio occupied by the granular antibacterial agent in the water-permeable porous bag is set within a range of 30 to 70%, the bacterial growth suppression performance of the antibacterial member can be further improved.

It is sectional drawing which shows typically one Embodiment of the drinking water server of this invention. It is sectional drawing which shows typically the air filter used for the said drinking water server. It is sectional drawing which expands and shows typically the external air intake part to which the said air filter is attached. It is a perspective view which shows typically the antibacterial member used for the said drinking water server. It is a graph which shows the relationship between a cumulative filter flow and a pore diameter of an Example. It is a graph which shows the relationship between pore diameter distribution and an average pore diameter of an Example. It is a graph which shows the analysis result of the colony number of the general living microbe in an Example and a comparative example. It is sectional drawing which shows the conventional drinking water server typically.

Next, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a cross-sectional view schematically showing an embodiment of the drinking water server of the present invention. As shown in FIG. 1, this drinking water server is similar to a conventional drinking water server (see FIG. 8), and includes a container connection part 11, a cold water tank 12, a hot water tank 13, a cold water side faucet 14a, a hot water side faucet 14b, and outside air. An intake port 15 and an air filter 1 are provided. Similar parts are denoted by the same reference numerals, and description thereof is omitted. In the drinking water server of this embodiment, as the air filter 1, as shown in an enlarged view in FIG. 2, the fluororesin porous membrane 1a and the protection fixed to both surfaces of the fluororesin porous membrane 1a are provided. And the pore diameter of the fluororesin porous membrane 1a is set in the range of 0.2 to 0.8 μm, and the pore diameter of the protective porous membrane 1b is the fluororesin porous membrane 1a. This is one of the features of the present invention. In this embodiment, as shown in FIG. 3 (the air filter 1 having the three-layer structure is shown as one layer in FIG. 3), the air filter 1 is external air that is airtightly attached to the external air intake 15. It is heat welded to the intake cylindrical body 3 so as to cover the hollow portion (flow path of outside air). Further, the air filter 1 is covered with a lid body 4 in a state in which ventilation is possible (see the arrow shown in FIG. 3).

Moreover, in the drinking water server of this embodiment, the antibacterial member 2 that has not been used in the conventional general drinking water server (see FIG. 8) is installed on the separator 18 in the cold water tank 12. Yes. As shown in FIG. 4, the antibacterial member 2 is composed of a plurality of granular antibacterial agents 2a and a water-permeable porous bag 2b in which the granular antibacterial agents 2a are sealed. The granular antibacterial agent 2a is composed of low density polyethylene and an ion exchanger in which silver ions are ion-bonded to zeolite. It is another feature of the present invention that the antibacterial member 2 is installed in a tank (in this embodiment, the cold water tank 12).

As described above, the drinking water server of the present invention employs the specific air filter 1 as the air filter 1, and is characterized by installing the specific antibacterial member 2 in the tank of the drinking water server. It is.

More specifically, polytetrafluoroethylene (PTFE) is preferable as the forming material (fluororesin) of the fluororesin porous membrane 1a constituting the air filter 1 (see FIG. 2). The fluororesin porous membrane 1a is produced, for example, by biaxially stretching a fluororesin semi-fired body 50 times or more and heat-treating it at a temperature not lower than the melting point of the fluororesin. Thereby, a fluororesin porous membrane 1a having a pore diameter in the range of 0.2 to 0.8 μm is produced.

Here, the pore diameter (within a range of 0.2 to 0.8 μm) of the fluororesin porous membrane 1a can be confirmed, for example, by a bubble point method. This bubble point method is performed as follows. That is, first, the fluororesin porous membrane 1a is impregnated with a fluorine-based test solution under atmospheric pressure. Next, the fluororesin porous membrane 1a is attached to an adapter, and the adapter is attached to the sample chamber of the porous material multi-physical property evaluation apparatus. Thereafter, the detection of the maximum pore diameter and the wetting flow rate curve (WET curve) are measured until the maximum pressure or the maximum flow rate is reached by the porous material multi-physical property evaluation apparatus. Moreover, the measurement of the dry curve (DRY curve) is measured until the maximum pressure or the maximum flow rate is reached by the porous material multi-physical property evaluation apparatus. And by the said measurement, the distribution of the hole diameter of the said fluororesin porous membrane 1a is obtained, and the range of the said hole diameter can be confirmed from this distribution.

The protective porous membrane 1b fixed on both surfaces of the fluororesin porous membrane 1a is preferably a nonwoven fabric or a woven fabric made of resin. The resin is the same as the resin material of the external air intake cylindrical body 3 from the viewpoint of simplifying the mounting structure by enabling heat welding to the external air intake cylindrical body 3 to which the air filter 1 is attached. Is preferred. An example of such a resin is polyethylene.

As a method for fixing the protective porous membrane 1b on both sides of the fluororesin porous membrane 1a, for example, the protective porous membrane 1b is superposed on both sides of the fluororesin porous membrane 1a and thermocompression bonded. Is called. As described above, the air filter 1 manufactured in this manner has a performance capable of preventing invasion of bacteria while sufficiently ensuring air permeability. Further, as described above, since the pore diameter of the protective porous membrane 1b is set to be larger than the pore diameter of the fluororesin porous membrane 1a, the performance depends on the fluororesin porous membrane 1a. Performance. From the viewpoint of improving the performance, the thickness of the fluororesin porous membrane 1a is preferably set in the range of 1 to 15 μm, more preferably about 2 to 9 μm. The thickness of the protective porous membrane 1b is preferably set in the range of 120 to 170 μm, more preferably about 145 μm.

Here, the thickness (within a range of 1 to 15 μm) of the fluororesin porous membrane 1a can be confirmed by, for example, a field emission scanning electron microscope. That is, first, since the fluororesin porous membrane 1a is very thin and flexible, the fluororesin porous membrane 1a is resin-embedded and hardened. Next, the cross section of the fluororesin porous film 1a is formed by a cross section polisher (CP). This cross section polisher is an apparatus for forming a cross section by irradiation with an ion beam, and is used when a sample is deformed when the cross section is formed by mechanical polishing. And the range of the said thickness can be confirmed by observing the cross section with the said field emission type scanning electron microscope. In order to reduce charging during observation, platinum may be coated on the cross section of the fluororesin porous membrane 1a.

Note that the air filter 1 has a performance of JIS Z 8122 that has a particle collection rate of 99.9995% or more with respect to particles having a rated air volume of 0.15 μm and an initial pressure loss of 245 Pa or less. It has the same performance as an ULPA (Ultra Low Low Penetration Air) filter, which is defined as “Air Filter”. The said pressure loss shows that it is excellent in air permeability, so that a value is small.

The outside air intake tubular body 3 (see FIG. 3) to which the air filter 1 is thermally welded is composed of an upper large-diameter portion 3a and a lower small-diameter portion 3b. The boundary part between 3a and the small diameter part 3b is formed in the step part. The peripheral portion of the circular air filter 1 is thermally welded to the step portion (the bottom portion of the large diameter portion). Further, four convex portions 3c (two are shown because FIG. 3 is a cross-sectional view) are evenly arranged on the upper end opening edge of the large diameter portion 3a. The upper end surface supports the lid 4 on the peripheral edge of the ceiling surface. And the clearance gap between the adjacent convex parts 3c becomes a flow path (refer the arrow shown in FIG. 3) of the outside air, and is connected with the hollow part of the said cylindrical body 3 for taking in outside air. In FIG. 3, reference numeral 3 d is an O-ring attached to the outer peripheral surface of the outside air intake cylindrical body 3, whereby the outside air intake cylinder 3 is attached to the outside air intake port 15. Then, the space between the outer peripheral surface of the outside air intake cylindrical body 3 and the inner peripheral surface of the external air intake port 15 is made airtight. Also, the outside air intake cylindrical body 3 is detachably attached to the outside air intake 15.

The lid 4 is formed in a cylindrical shape. The top surface is formed into a curved surface that gradually decreases from the central portion toward the peripheral portion, and the curved surface prevents dust, water droplets, and the like from accumulating on the top surface. Further, on the inner surface of the peripheral side surface of the lid body 4, there are 4 engagement claws (not shown) that are detachably engaged with the lower edge of the large-diameter portion 3 a of the outside air intake cylindrical body 3. They are arranged evenly and are detachably attached to the outside air intake tubular body 3 by their engaging claws. The lid 4 is attached to the upper part of the outside air intake cylindrical body 3 so as to cover the air filter 1, thereby preventing dust, water droplets, and the like from coming into contact with the air filter 1.

On the other hand, the production of the granular antibacterial agent 2a constituting the antibacterial member 2 (see FIG. 4) is, for example, about 100 μm in which an ion exchanger in which silver ions are ion-bonded to the zeolite is supported on the low density polyethylene. The powder is heat-molded at about 100 ° C., and the low-density polyethylene resin is not completely dissolved, leaving a void. From the viewpoint of suppressing the growth of bacteria, the ratio of the low density polyethylene to the ion exchanger (low density polyethylene / ion exchanger) is (70 wt% / 30 wt%) to (95 wt% / 5 wt). %), And more preferably (90% by weight / 10% by weight). The average diameter of the granular antibacterial agent 2a is preferably set in the range of 3 to 10 mm, more preferably about 6 mm. The mass of the granular antibacterial agent 2a having an average diameter of 6 mm is about 53.3 mg / piece. In addition, as said ion exchanger, what is shown by following Chemical formula (1) is mention | raise | lifted, for example. The silver content in the granular antibacterial agent 2a is in the range of 0.1 to 0.5% by weight, preferably 0.2 to 0.3% by weight. Moreover, the said average diameter measures the diameter of arbitrary 1 places with calipers about arbitrary 10 granular antibacterial agents 2a, and takes those average values.

Here, the silver content (within a range of 0.1 to 0.5% by weight) in the granular antibacterial agent 2a can be confirmed by, for example, ICP emission analysis. That is, first, sulfuric acid is added to the granular antibacterial agent 2a to ash the granular antibacterial agent 2a. Next, the ashed product is treated with hydrofluoric acid and then melted with potassium hydrogen sulfate. Next, dissolve in dilute nitric acid and make a constant volume with pure water. And it can be applied to an ICP emission analyzer to confirm the silver content.

Moreover, it is preferable that the water-permeable porous bag 2b which comprises the said antibacterial member 2 is the nonwoven fabric or woven fabric which consists of resin. The resin is preferably a composite material of, for example, polyethylene terephthalate and polyethylene from the viewpoint of strength and the like. The mass of the nonwoven fabric or the like is preferably set in the range of 17.0 to 27.0 g / m ² , more preferably 22.4 g / m ² . The thickness of the nonwoven fabric or the like is preferably set in the range of 0.05 to 0.15 mm, more preferably 0.10 mm. Further, from the viewpoint of improving water permeability, the pore diameter of the nonwoven fabric is preferably set in the range of 50 to 100 μm.

And sealing of the granular antibacterial agent 2a to the said water-permeable porous bag 2b is performed by wrapping the granular antibacterial agent 2a with the said nonwoven fabric etc., and heat-sealing the peripheral parts, such as the nonwoven fabric, and making it into a bag shape, for example. . From the viewpoint of making the contact between the granular antibacterial agent 2a and drinking water more appropriate and further suppressing the growth of bacteria, and making the passage of drinking water through the antibacterial member 2 more appropriate, the water-permeable porous bag. The volume ratio occupied by the granular antibacterial agent 2a in 2b is preferably set in the range of 30 to 70%.

In the above embodiment, the antibacterial member 2 is installed on the separator 18 in the cold water tank 12, but it may be installed below the separator 18.

In the above embodiment, the two tanks, the cold water tank 12 and the hot water tank 13, are provided, but only one of the tanks may be provided. In that case, since the separator 18 is not necessary, the installation position of the antibacterial member 2 may be any position in the tank.

Next, examples will be described together with comparative examples. However, the present invention is not limited to the examples.

The drinking water server shown in FIG. 1 was prepared. The air filter has a diameter from a sheet material (Daikin Co., Ltd., Neurofine (registered trademark), total thickness 300 μm) formed by heat-pressing a polyethylene porous film (thickness 145 μm) on both sides of a PTFE porous membrane (thickness 10 μm). What was punched into a 22.8 mm circle was used. The pore diameter of the PTFE porous membrane of the air filter was confirmed to be within the range of 0.2 to 0.8 μm as a result of confirmation by the bubble point method. The air filter satisfies the ULPA filter particle collection rate of 99.9995% or more and the initial pressure loss of 245 Pa or less specified in JIS Z 8122. Then, the peripheral portion of the circular air filter is subjected to an outside air intake cylinder by ultrasonic waves (oscillator output 1200 W, oscillation frequency 15.15 ± 0.15 kHz, welding time 0.2 seconds, holding time 0.4 seconds). It heat-sealed so that the hollow part (flow path of external air) of a shape body might be covered. The channel diameter of the outside air intake cylindrical body was 14 mm. The particulate antibacterial agent constituting the antibacterial member comprises 90% by weight of low density polyethylene and 10% by weight of an ion exchanger in which silver ions are ion-bonded to zeolite, and has an average diameter of 6 mm (53.3 mg / piece). A heat-molded product (PB6LJ10-1 manufactured by Sinanen Zeomic Co., Ltd .: silver content 0.23% by weight) was used. Then, 30 g of the granular antibacterial agent is weighed, and a non-woven fabric (22.4 g / m ² , pore diameter 50 to 100 μm) made of a composite material of polyethylene terephthalate and polyethylene is formed into a bag shape (170 mm × 90 mm). The water-permeable porous bag was sealed and sealed by heat sealing. The volume ratio occupied by the granular antibacterial agent inside the water-permeable porous bag was 50%.

Here, the bubble point method was performed as follows. That is, first, the above-mentioned fluororesin porous membrane was impregnated with Galwick (fluorine type test solution, surface tension 0.0157 N / m) under atmospheric pressure. Then, it was measured with a porous material multi-physical property evaluation apparatus (manufactured by PMI, USA, palm porometer: CFP-1200AEXLCBBJ). As a result, the “cumulative filter flow vs. pore diameter” graph shown in FIG. 5 and the “pore diameter distribution vs. average pore diameter” graph shown in FIG. 6 were obtained. From these graphs, a peak was confirmed with a pore size around 0.39 μm as a maximum, and it was confirmed that the pore size was in the range of 0.2 to 0.8 μm. It was also confirmed that the average flow pore size was 0.389 μm and the maximum pore size was 0.386 μm.

Further, the silver content (0.23% by weight) in the granular antibacterial agent was confirmed by an ICP emission analysis method using an ICP emission analyzer (ICPS-8100, manufactured by Shimadzu Corporation).

[Comparative Example 1]
In the drinking water server of the above example, a polyethylene sponge (circular shape with a diameter of 22.8 mm, thickness of 5 mm) was used as an air filter, and was attached to a cylindrical body for taking in outside air (without heat welding). The other parts were the same as in the above example.

[Comparative Example 2]
In the drinking water server of the above embodiment, the antibacterial member is not installed. The other parts were the same as in the above example.

[Comparative Example 3]
In the drinking water server of the above example, a polyethylene sponge (circular shape with a diameter of 22.8 mm, thickness of 5 mm) was used as an air filter, and was attached to a cylindrical body for taking in outside air (without heat welding). Moreover, the antibacterial member was not installed. The other parts were the same as in the above example.

[Method of analyzing the number of general viable colonies]
The drinking water servers of the above Examples and Comparative Examples 1 to 3 were installed on the floor (area 600 m ² ) of an office where 80 people perform office work. And about each drinking water server, the number of colonies of general viable bacteria was analyzed for 14 days as follows, and was shown with the graph in FIG.
(A) First, each part of the drinking water server was sterilized and washed by hot water sterilization and alcohol sterilization.
(B) Next, a gallon bottle containing 12 L of mineral water (AW Water, manufactured by East Japan Air Water Energy Co., Ltd.) was attached to each drinking water server.
(C) Next, 500 mL of mineral water was collected from the cold water side faucet and discarded.
(D) Then, 100 mL of mineral water is collected from the cold water side faucet into a 100 mL polyethylene sterilized water sampling bottle (Sansei Medical Equipment Co., Ltd., model number 2-6425-05). General viable bacteria were cultured in (manufactured by Sumitomo 3M Ltd., model number 6400AC, medium inoculation area 20 cm ² ).
(E) After 48 hours, the number of colonies in the Petri film medium was visually counted at a dilution factor of 1. At this time, when the number of colonies exceeds 250, the average value of the number of colonies in the 1 cm ² lattice of the Petri film medium is obtained, and the number of colonies is estimated by multiplying it by 20. In addition, the upper limit of the number of colonies when the dilution factor was 1 was set to 2500.
(F) For each drinking water server, the number of colonies was confirmed once a day as in (c) to (e) above.

As shown in the graph of FIG. 7, in the drinking water server of the example, no viable bacteria were confirmed at all for 14 days. On the other hand, in the drinking water server of Comparative Example 1, general viable bacteria were confirmed from the 9th day, and increased slightly thereafter, and rapidly increased after the 11th day. From this, in Comparative Example 1 using a coarse air filter, general viable bacteria had invaded and sterilization was possible by the action of the antibacterial member until the 9th day. It can be seen that general bacteria that exceed the ability to suppress bacterial growth have invaded. Moreover, in the drinking water server of the comparative example 2, general viable bacteria were confirmed from the 2nd day, and increased only a little after that, and increased rapidly after the 7th day. Therefore, in Comparative Example 2, the fine air filter can prevent the invasion of general viable bacteria to some extent, but since there is no antibacterial member, the invading general viable bacteria grow and the number of colonies cannot be controlled. I understand that. And in the drinking water server of the comparative example 3, general viable bacteria were confirmed from the 2nd day, and it increased only a little after that, increased rapidly after the 3rd day, and reached the upper limit 2500 pieces on the 12th day. In this test, since the upper limit is set to 2500, in the graph of FIG. 7, it is 2500 after the 12th day, but there is a possibility that the 12th day is also proliferating. From this, it can be seen that in Comparative Example 3, the air filter has a rough mesh, so that viable bacteria can easily invade, and since there is no antibacterial member, the invading common viable bacteria can easily grow. From the above, it can be seen that the combined use of the specific air filter and the specific antibacterial member as in the drinking water server of the example is useful for suppressing the number of colonies of general viable bacteria.

In the above examples, the thickness of the PTFE porous membrane and the polyethylene porous membrane of the air filter were changed, and the number of colonies of general viable bacteria was analyzed in the same manner as described above. As a result, the PTFE porous membrane was analyzed. When the thickness of the membrane was set in the range of 1 to 15 μm and the thickness of the polyethylene porous membrane was set in the range of 120 to 170 μm, similar results to the above examples were obtained.

Here, the thickness of the fluororesin porous membrane (within a range of 1 to 15 μm) was confirmed as follows. That is, first, the main agent [Oken Trading Co., epoch 812 (EM grade)], the curing agent [Oken Shoji, MNA (methyl nadic anhydride)], the polymerization accelerator [Oken Trading Co., Ltd. M.M. P. Using an epoxy resin made of -30 (Tri-dimethylaminophenyl), the fluororesin porous membrane was embedded and solidified. Next, a cross section of the fluororesin porous membrane was formed by a cross section polisher (manufactured by JEOL Ltd., SM-09010). At that time, argon was used as the processing ions, the ion acceleration voltage was 5 kV, the processing speed was 1.3 μm / min (acceleration voltage 6 kV, converted to SiO ₂ ), and the cross-sectional positioning accuracy was 15 μm (positioning with an optical microscope). Thereafter, a platinum coating for reducing charge was applied to the cross section. The cross section was observed at a magnification of 3500 using a field emission scanning electron microscope (S-4800, manufactured by Hitachi High-Technologies Corporation). As a result, the thickness of the cross section was non-uniform, but it was formed within the range of 1 to 15 μm.

In addition, the numerical ratio of the particulate antibacterial agent component ratio of the antibacterial member, the average diameter of the granular antibacterial agent, the pore diameter of the water-permeable porous bag, and the volume ratio occupied by the granular antibacterial agent inside the water-permeable porous bag are changed as described above. As a result of analyzing the number of colonies of general viable bacteria in the same manner as described above, the ratio (low density polyethylene / ion exchanger) of the low density polyethylene and the ion exchanger constituting the granular antibacterial agent (70 wt% / 30) Wt%) to (95 wt% / 5 wt%), the average diameter of the granular antibacterial agent is set within the range of 3 to 10 mm, and the pore diameter of the water-permeable porous bag is within the range of 50 to 100 μm When the volume ratio was set within the range of 30 to 70%, a preferable result was obtained as in the above example.

In the above embodiments, specific forms in the present invention have been described. However, the above embodiments are merely examples and are not construed as limiting. Further, all modifications belonging to the equivalent scope of the claims are within the scope of the present invention.

The drinking water server of the present invention uses a specific air filter and a specific antibacterial member in combination to prevent the invasion of bacteria due to the intake of outside air and to suppress the growth of bacteria in the drinking water server. Management is realized with a simple structure.

1 Air filter 2 Antibacterial member

Claims

A container connecting part for detachably connecting a mouth part of a container containing drinking water, a tank provided below the container connecting part for storing drinking water dropped from the container, and drinking water stored in the tank A drinking water server comprising: a faucet that collects water; an outside air intake port that communicates with the inside of the container containing drinking water through the container connecting portion; and an air filter that covers the outside air intake port. And the said air filter is an air filter of the following (A), The antibacterial member of the following (B) is installed in the said tank, The drinking water server characterized by the above-mentioned.
(A) a fluororesin porous membrane and a protective porous membrane fixed on both front and back surfaces of the fluororesin porous membrane, and the pore diameter of the fluororesin porous membrane is in the range of 0.2 to 0.8 μm And an air filter in which the pore diameter of the protective porous membrane is set to be equal to or larger than the pore diameter of the fluororesin porous membrane.
(B) It consists of a plurality of granular antibacterial agents and a water-permeable porous bag in which these granular antibacterial agents are sealed, and the granular antibacterial agent comprises low density polyethylene and an ion exchanger in which silver ions are ion-bonded to zeolite. An antibacterial member.
2. The air filter according to (A), wherein the thickness of the fluororesin porous membrane is set in a range of 1 to 15 μm, and the thickness of the protective porous membrane is set in a range of 120 to 170 μm. The described drinking water server.
In the antibacterial member of (B), the ratio of the low density polyethylene and the ion exchanger (low density polyethylene / ion exchanger) constituting the granular antibacterial agent is (70% by weight / 30% by weight) to (95% by weight). / 5 wt%), the average diameter of the granular antibacterial agent is set in the range of 3 to 10 mm, the pore diameter of the water-permeable porous bag is set in the range of 50 to 100 μm, The drinking water server according to claim 1 or 2, wherein a volume ratio occupied by the granular antibacterial agent in the aqueous porous bag is set within a range of 30 to 70%.