WO2012091457A2

WO2012091457A2 - Antimicrobial pad, method for manufacturing antimicrobial pad, toilet seat having antimicrobial pad, and method for sterilizing toilet

Info

Publication number: WO2012091457A2
Application number: PCT/KR2011/010242
Authority: WO
Inventors: Sun-Beom CHOI; Ji-Hye Jeong; Joong-Keun AN; Sun-Dug Kwon; Hyung-Tae Kim
Original assignee: Woongjin Coway Co., Ltd
Priority date: 2010-12-30
Filing date: 2011-12-28
Publication date: 2012-07-05
Also published as: WO2012091457A3

Abstract

The present invention relates to an antimicrobial pad, a manufacturing method thereof, a toilet having an antimicrobial pad, and a method for sterilizing a toilet, and particularly to an antimicrobial pad in which the release of antimicrobials is facilitated by a rise in temperature, a manufacturing method thereof, a toilet seat having an antimicrobial pad, and a method for sterilizing a toilet. An antimicrobial pad of the present invention may comprise polyurethane foam having pore voids of a predetermined size, and a microcapsule containing antimicrobials therein, provided to be encapsulated within the pore voids of the polyurethane foam. A toilet seat having an antimicrobial pad of the present invention may comprise a toilet seat body having a structure mounted in a toilet, and a toilet seat cover connected to the toilet seat body and has the antimicrobial pad.

Description

[DESCRIPTION]

[Invention Title]

ANTIMICROBIAL PAD, METHOD FOR MANUFACTURING ANTIMICROBIAL PAD, TOILET SEAT HAVING ANTIMICROBIAL PAD, AND METHOD FOR STERILIZING TOILET

[Technical Field]

The present invention relates to an antimicrobial pad, a method for manufacturing an antimicrobial pad, a toilet having an antimicrobial pad, and a method for sterilizing a toilet, and more particularly to an antimicrobial pad in which the release of antimicrobials is facilitated by a rise in temperature, a method for manufacturing an antimicrobial pad, a toilet seat having an antimicrobial pad, and a method for sterilizing a toilet.

[Background Art]

In general, when entering a restroom, even if the atmosphere thereof is relatively clean, sitting on a toi let immediately may be a very uninviting thing to do as there may be a contamination in toilets due to the use thereof by many people and due to poor maintenance, bacteria may grow due to the nature of the restroom.

As related art in the field of using toilets more cleanly, tearing off portions of toilet paper to thoroughly wipe off a toilet seat or spreading toilet paper out evenly on the toilet seat to sit thereon, have been selected. In addition, a sanitary sheet made from paper and biodegradable synthetic resins and cut to the shape of a toilet seat has been commercially used in the past. However, it may be so thin as to convey the cold touch of the toilet seat to a user' s buttock leaving a user feeling uncomfortable.

According to recent research, more than 90% of women do not sit directly on the toilet seat. While toilet paper has come into widespread use and can be found in almost every house, toilet seat cover sheets can only be found in toilets provided in selected public places, such as hospitals, airports, hotels, and so on.

There are several factors inhibiting the widespread commercial adaptation of toilet seat cover sheets. For one thing, due to packaging and storage of individually folded toilet seat cover sheets, general manufacturing costs thereof are high. For another thing, the volume of a dispenser for cover sheets may be relatively bulky, such that a restroom should have enough space to accommodate the toilet seat cover sheet dispenser. For these reasons, ordinary people and owners of smaller-scale public places such as restaurants prefer not to purchase bulky, expensive cover sheets.

Meanwhile, bidets are currently more available in restrooms and users can thereby use the restroom with more comfortable and in a cleaner atmosphere. However, when using a bidet in publ ic places or at home, the issue of cleanliness has come to the fore.

Therefore, when using a toilet bowl or a bidet-installed toilet bowl, simplified methods of sterilizing a toilet seat having an antimicrobial pad in a sanitary manner are still required. Therefore, antimicrobial pads having antimicrobial agents have been needed to sterilize toilet seats easily. [Disclosure]

[Technical Problem]

The present invention has been devised to solve the above problems of the related art , and an aspect of the present invent ion provides an antimicrobial pad and a method for manufacturing an antimicrobial pad in which the release of antimicrobials from the antimicrobial pad is facilitated by a rise in temperature to thus sterilize peripheral devices, the antimicrobial pad having excellent durability and a long effective lifespan.

Another aspect of the present invention provides a toilet seat having an antimicrobial pad and a method for sterilizing a toilet in which the antimicrobial pad can sterilize the toilet seat and bacteria present in the toilet without any particular sterilizing devices by attaching the antimicrobial pad to a toilet seat cover.

Another aspect of the present invention provides a toilet seat having an antimicrobial pad and a method for steri lizing a toi let in which, when using the toilet seat having an antimicrobial pad without a separate sheet, the antimicrobial pad can sterilize the toilet seat having the antimicrobial pad and the toilet through released antimicrobials by attaching the antimicrobial pad to a toilet seat cover, particularly to a bidet-instal led toilet seat cover, heating the toilet seat cover to a predetermined temperature, and facilitating the outward release of antimicrobials.

[Technical Solution]

According to an aspect of the present invention, there is provided an antimicrobial pad comprising: polyurethane foam having pore voids of a predetermined size; and a microcapsule containing antimicrobials therein, provided to be encapsulated within the pore voids of the polyurethane foam to coat the surface of the polyurethane foam.

The microcapsule may comprise silica gel having a hollow capsule shape with a particle size of from about 3 to about 10 μχα^', and the antimicrobials present in the silica gel.

The antimicrobials may be propolis extract.

Meanwhile, the silica gel may have a structure in which pores are porous when the antimicrobial pad is heated, and the pores can be enlarged in order to facilitate the outward release of the antimicrobials.

Preferably, the polyurethane foam may have pore voids ranging from about 10 jtrni to about 500 μιη.

Preferably, the polyurethane foam may have pore voids ranging from about 10 μια to about 120 #m.

Preferably, the polyurethane foam may have pore voids ranging from about 80 [mi to about 120 -

Meanwhi le, in order to increase the durabi 1 ity thereof, the antimicrobial pad may further comprise a fixing binder improving adhesiveness between the polyurethane foam and the microcapsule.

The fixing binder may be a si lane coupling agent.

Herein, the antimicrobials may be propolis extract and the microcapsule may contain the propolis extract in an amount of from about 20,000 ppm to about 50,000 ppm.

According to another aspect of the present invention, there is provided a method for manufacturing an antimicrobial pad comprising operations of: a) preparing a microcapsule with propolis extract through a sol-gel process; and b) coating the surface of polyurethane foam with the microcapsule.

Meanwhile, according to the present invention, there is provided a method for manufacturing an antimicrobial pad comprising operations of: a) preparing a microcapsule with propol is extract through a sol -gel process; andb-1) mixing the microcapsule with a fixing binder to prepare a mixed solution and coating the surface of polyurethane foam therewith.

The fixing binder may be a si lane coupling agent.

Preferably, the microcapsule may contain the propolis extract in an amount of from about 20,000 ppm to about 50,000 ppm.

The propolis extract may be extracted through vacuum ultrasonic extraction after removing beeswax from a beehive through hot water gravity separation.

Preferably, the microcapsule may have a particle size of from about 3 im to about 10 yum .

Preferably, the polyurethane foam may have pore voids ranging from about 10 πι to about 120 /zm .

Preferably, the polyurethane foam may have pore voids ranging from about 80 im to about 120 [m.

Preferably, the polyurethane foam may have pore voids ranging from about 10 pm to about 500 fm.

Meanwhile, the microcapsule may be prepared by emulsifying a mixed solution comprising propolis extract, tetraethylorthosi 1 icate (TEOS), and partially hydrolyzed si lane into a solution in which an acid or alkali is dissolved and has polarity opposite to the propolis extract to cause a sol-gel process at the interface to thus encapsulate propolis extract. Meanwhile, operation b) or b-1) may be performed by spraying or co-dipping.

Operation b) may comprise pretreating the polyurethane foam by spraying an alcohol containing an expansion agent over the polyurethane foam to thus enlarge the size of pore voids therein; spraying the microcapsule over the pretreated polyurethane foam or co-dipping the pretreated polyurethane foam with the microcapsule; and drying the spraying-treated or co-dipping treated polyurethane foam.

Operat ion b-1) may comprise pretreat ing the polyurethane foam by spraying an alcohol containing an expansion agent over the polyurethane foam to thus enlarge the size of pore voids therein; spraying a mixed solution of the microcapsule and the si lane coupling agent over the pretreated polyurethane foam or co-dipping the pretreated polyurethane foam with a mixed solution of the microcapsule and the si lane coupling agent; and drying the spraying-treated or co-dipping treated polyurethane foam.

Meanwhile, according to another aspect of the present invention, there is provided a toilet seat having an antimicrobial pad comprising a toilet seat body having a structure mounted in a toilet; and a toilet seat cover connected to the toilet seat body to be opened and closed and having an antimicrobial pad in which the outward release of antimicrobials is facilitated by a rise in temperature.

One side of the antimicrobial pad may be connected to the inner side of the toilet seat cover and the antimicrobial pad may comprise polyurethane foam having pore voids; and a microcapsule containing antimicrobials therein, provided to be encapsulated within the pore voids of the polyurethane foam.

Meanwhile, according to another aspect of the present invention, there is provided a toilet seat having an antimicrobial pad comprising a toilet seat body having a structure mounted in a toilet; and a toilet seat cover connected to the toi let seat body to be opened and closed and having an antimicrobial pad coated with a microcapsule containing antimicrobials therein.

One side of the antimicrobial pad may be connected to the inner side of the toilet seat cover and the antimicrobial pad may comprise polyurethane foam having pore voids and the microcapsule may be provided to be encapsulated within the pore voids of the polyurethane foam.

Preferably, the polyurethane foam may have pore voids ranging from about 10 [M to about 120 fm.

Preferably, the polyurethane foam may have pore voids ranging from about 80 to about 120 μκι.

Preferably, the polyurethane foam may have pore voids ranging from about 10 jtffli to about 500 /m. Meanwhile, the microcapsule may comprise silica gel having a hollow capsule shape with a particle size of from about 3 jam to about 10 #m; and antimicrobials present in the silica gel.

The antimicrobials may be propolis extract.

Meanwhile, the silica gel may have a structure having pores and when the toilet seat cover is heated by a heating unit embedded in the toilet seat body, the pores can be enlarged in order to facilitate the outward release of the antimicrobials.

In order to increase the durability thereof, the antimicrobial pad may further comprise a fixing binder improving adhesiveness between the polyurethane foam and the microcapsule.

Herein, the fixing binder may be a si lane coupling agent.

The antimicrobials may be propolis extract and the microcapsule may contain the propolis extract in an amount of from about 20,000 ppm to about 50,000 ppm.

Meanwhile, according to another aspect of the present invention, there is provided a method for sterilizing a toilet wherein the method comprises operations of a), inputting the sterilization operation to a control unit connected to the toilet seat body; and b), heating a heating unit embedded in the toilet seat body by the operation of the control unit so that when the . sterilization operation is inputted, the temperature of the antimicrobial pad is elevated to reach a predetermined point, antimicrobials are released from the antimicrobial pad and the released antimicrobials are diffused into the inner part of the toilet, and thus, the toilet seat body and the toilet are sterilized by the antimicrobials.

In operation a), the control unit may be operated to perform the sterilization operation in a covered state in which the toilet seat cover is laid on top of the toilet seat body and may not perform the sterilization operation in a uncovered state in which the toilet seat cover is not laid on top of the toilet seat body.

The method for sterilizing a toilet may further comprise operation c) stopping the operation of the heating unit to stop the release of antimicrobials from the antimicrobial pad after a lapse of a pre-set predetermined time or an input of the sterilization stop, after operation b).

[Advantageous Effects]

An antimicrobial pad according to one embodiment of the present invention can facilitate the release of antimicrobials by a rise in temperature to thus sterilize peripheral devices.

In addition, a method for manufacturing an antimicrobial pad according to another embodiment of the present invention can provide an antimicrobial pad having excellent durability and a long effective lifespan.

Further, a toilet seat having an antimicrobial pad according to another embodiment of the present invention can sterilize the toilet seat having an antimicrobial pad and bacteria present in the toilet without any particular sterilizing devices.

Further, before using the toilet seat having an antimicrobial pad according to another embodiment of the present invention, the toi let seat having an antimicrobial pad and the toilet can be sterilized with released antimicrobials by attaching the antimicrobial pad to the toilet seat cover, particularly to the bidet-installed toilet seat cover, and heating the toilet seat cover to a predetermined temperature in a covered state in which the toi let seat cover is laid on top of the toilet seat body and facilitating the outward release of antimicrobials without a separate sheet.

[Description of Drawings] The above and other aspects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

FIG. 1 shows the real shape of a microcapsule for one embodiment of the present invention photographed using a scanning electron microscope (SEM) ;

FIG. 2 is the schematic diagram which shows the structure of a microcapsule for one embodiment of the present invention and the principle of propolis release;

FIG. 3 shows photographs of the real shape of an antimicrobial pad sample in each operation in which the antimicrobial pad sample is prepared by a method of the present invention;

FIG. 4 shows results of testing the antimicrobial effect of an antimicrobial pad according to the present invention;

FIG. 5(a) shows the method of an experiment for testing the antimicrobials release from the antimicrobial pad and FIG. 5(b) shows the result of the experiment; and the experiment is to investigate whether the antimicrobial pad according to the present invention shows the antimicrobial activity over time at a specific temperature and at a specific distance;

FIG. 6 is a schematic perspective view of a toilet seat having an antimicrobial pad in which the toilet seat is installed in a toilet according to an embodiment of the present invention;

FIG. 7 is a schematic cross section of the toilet seat in which the toi let seat is instal led in the toi let and the antimicrobial pad is instal led in the toilet seat according to the embodiment of the present invention;

FIG. 8 is a schematic cross section of the toilet seat when antimicrobials are released from the antimicrobial pad by heating the antimicrobial pad according to the embodiment of the present invention; and

FIG. 9 is a schematic diagram shows the case in which a fixing binder is installed in an antimicrobial pad according to an embodiment of the present invention and the chemical bonding thereof.

[Mode for Invention]

The present invention will now be described in detail with reference to the accompanying drawings.

First, exemplary embodiments described below are proper embodiments to give understanding about features of an antimicrobial pad, a method for manufacturing an antimicrobial pad, a toilet seat having an antimicrobial pad, and a method for steri 1 izing a toi let of the present invention. However, neither applications nor features of the present invention are limited to exemplary embodiments described below, and various modifications can be made within the scope of the present invention.

First, an antimicrobial pad according to one embodiment of the present invention will now be described.

An antimicrobial pad 100 of the present invention comprises a microcapsule 110 containing propolis extract and a polyur ethane foam 120. Herein, the microcapsule 110 is prepared on the surface of the polyurethane foam 120.

As shown in FIG.2, the microcapsule 110 includes a silica gel 111 formed by a sol-gel process and antimicrobials 115 present in the silica gel 111.

In one embodiment of the present invention, the silica gel 111 which forms the exterior of the microcapsule 110 is a material in which pores 113 are formed, and the silica gel 111 has a structure in which the pores 113 can be enlarged in order to release the antimicrobials 115 outwardly when the temperature is elevated to reach a predetermined point (for example, from about 40^°C to about 50 ^°C).

The si lica gel 111 may have a hoi low capsule shape having a particle size of from about 3 πι to about 10 fim, but is not limited thereto. However, where the microcapsule 110 is formed to have a size of less than about 3 im, the amount of the antimicrobials 115 (propolis extract) contained therein decreases. Therefore, the antimicrobial effect may be deteriorated and the durability of the microcapsule 110 may be weakened. In addition, in the case that the microcapsule 110 is formed to have a size of more than about 10 m, preparation of the microcapsule 110 is difficult due to processes required therefor.

In one embodiment of the present invention, the amount of the microcapsule 110 is not particularly limited, but may be from about 3 weight to about 20 weight % of a total weight of the antimicrobial pad 100. Where the amount of the microcapsule 110 is less than 3 weight%, the antimicrobial effect may be poor and where the amount is more than 20 weight%, the antimicrobial effect may not be able to be increased, and may be relatively costly. Meanwhile, the polyurethane foam 120, the remaining component of the antimicrobial pad 100 may be present as the remaining amount, namely, from about 80 weight% to about 97 weight%.

In one embodiment of the present invention, the silica gel 111 has the property of slowly releasing the inner material , the antimicrobials 115 at room temperature, and when the silica gel 111 is heated to from about 40°C to about 50^*C , the outward release of the antimicrobials 115 is facilitated as shown in Start of release in FIG. 2.

Here, substances containing propolis extract may be used for the antimicrobials 115. Specifically, the microcapsule 110 may be prepared by emulsifying a mixed solution comprising propolis extracts, tetraethylorthosi 1 icate (TEOS) , and part ial ly hydrolyzed si lane into a solut ion in which an acid or alkali is dissolved and has a polarity opposite to that of the propolis extract to cause a sol-gel process at the interface to thus encapsulate propolis extract.

Meanwhile, in one embodiment of the present invention, the polyurethane foam 120 contains pore voids (i.e. porous eel Is) so that it has a structure which allows the microcapsule 110 to be easily entrapped therein.

In one embodiment of the present invention, when the antimicrobial pad 100 of the present invention is used for sterilizing a toilet seat having an antimicrobial pad, the polyurethane foam 120 may have pore voids ranging from about 10 jiflii to about 500 μχ&, preferably from about 10 im to about 120 //m, and more preferably from about 80 pm to about 120 μαΐ-

However, where the size of pore voids of the polyurethane foam 120 is less than about 10 p , the microcapsule 110 may not be entrapped into pore voids and the antimicrobial effect may be deteriorated. Where the size of pore voids in the polyurethane foam 120 is more than about 500 m, the microcapsule 110 maybe accommodated in pore voids, but maybe leaked again, and the antimicrobial effect may be deteriorated.

Where the size of pore voids of the polyurethane foam 120 is more than about 500 im, to entrapment of the microcapsule 110 in pore voids in the polyurethane foam 120 is facilitated. Where the size of pore voids of the polyurethane foam 120 is less than about 120 jtan, the leakage of the microcapsule 110 encapsulated in the polyurethane foam 120 is not easy and the antimicrobial effect thereof may be improved.

In one embodiment of the present invention, the antimicrobial life of the antimicrobials 115 contained in the microcapsule 110 may be controlled by controlling the size of pore voids in the polyurethane foam 120 used for the antimicrobial pad 100 within the range stated above and thus controlling the amount of the microcapsule 110 impregnated in the polyurethane foam 120.

Meanwhile, where the polyurethane foam 120 according to one embodiment of the present invention is too thick, the exterior isnot aestheticallypleasing, while in the case it is too thin, the amount of the microcapsule 110 containing the antimicrobials 115 may be too small and the antimicrobial activity thereof may be weak. Therefore, the thickness of the polyurethane foam 120 may range from about 0.5 mm to about 5 mm, but is not limited thereto.

In one embodiment of the present invention, an example of a material on which the microcapsule 110 is coated is the polyurethane foam 120, but not limited to this, and may be any material having pore voids therein or on the surface and thus the microcapsule 110 can be attached thereto like polyurethane foam. Meanwhile, the antimicrobial pad 100 according to one embodiment of the present invention may further comprise a fixing binder 130 improving adhesiveness between the polyurethane foam 120 and the microcapsule 110 in order to increase the durability thereof.

In addition, the fixing binder 130 may be a si lane coupling agent.

In other words, characteristics of a polymer and its filler like the polyurethane foam 120 and the microcapsule 110 are different and mostly, the complete adhesion does not occur at the polymer-fi 1 ler interfaces. In this case, a possibility of the leak of the microcapsule 110 from pore voids in the polyurethane foam 120 becomes higher and the durability of the antimicrobial pad may be weak.

Therefore, the antimicrobial pad 100 according to one embodiment of the present invention may use a si lane coupling agent as the fixing binder 130 like example shown in FIG. 9 in order that the microcapsule 110 may adhere strongly to the polyurethane foam 120. Accordingly, the leak of the microcapsule 110 entrapped in pore voids of the polyurethane foam 120 out of the pore voids may be prevented, and therefore, the durability of the antimicrobial pad 100 may be improved and the lifespan of the antimicrobial pad 100 may be lengthened.

Examples of the si lane coupling agent include amine-based si lane coupl ing agents, sulfur-based si lane coupling agents, alkyl-based si lane coupling agents, and the like, and various si lane coupling agents indicated above may be used without limitation. Besides the examples indicated above, any silane coupling agents may be used and there is no limitation to the kind of silane coupling agents. Examples of the amine-based silane coupling agents include 3-aminopropyltrimethoxysi lane, 3-aminopropyltriethoxysi lane,

3-aminopropylmethyldiethoxysi lane, aminopropylsi lane triol, and N-(2-aminoethyl)-3-aminopropyltrimethoxysi lane. Examples of the sulfur-based silane coupling agents include 3-mercaptiopropyltrimethoxysi lane and bis[3-(triethoxysi lyDpropylltetrasulf ide.

However, the fixing binder 130 is not limited to the silane coupling agents and various binders which can strengthen the attachment between the polyurethane foam 120 and the microcapsule 110 may be applied thereas.

A method for manufacturing an antimicrobial pad according to another embodiment of the present invention will now be described.

A method for manufacturing an antimicrobial pad 100 of the present invention comprises: preparing a microcapsule 110 containing propolis extract through sol-gel process with propolis extracts; and coating the surface of a polyurethane foam 120 with the microcapsule 110 containing propolis extract.

First, the propolis extract may be obtained using ordinary extraction methods through which effective components can be obtained from naturally occurring materials. Examples include hot water gravity separation followed by vacuum ultrasonic extraction, supercritical fluid extraction, vapor extraction, and solvent extraction.

The propolis extract may be extracted through vacuum ultrasonic extraction after removing beeswax from a beehive through hot water gravity separation. In addition, the propolis extract may be purchased commercially for use. Preferably, the propol is extract maybe extracted through vacuum ultrasonic extraction after removing beeswax from a beehive through hot water gravity separation.

The propolis extract is microcapsulated and the microcapsule 110 can be prepared by a generally known microencapsulation processes. For example, the microcapsule 110 may be prepared by, but is not limited to, sol-gel process disclosed in the Korean Patent Publication No. 2003-0064126.

For one example, the microcapsule 110 may be prepared by emulsifying a mixed solution comprising propolis extracts, tetraethylorthosi 1 icate (TE0S), and partially hydrolyzed silane into a solution in which an acid or alkali is dissolved and has polarity opposite to that of the propolis extract to cause a sol-gel process at the interface to thus encapsulate propolis extract.

The particle size of the microcapsule 110 containing propolis extract prepared by the mi crocapsul at ion process like this is not particularly limited, but, preferably, may be from about 3 to about 10 im as described above.

Then, the microcapsule 110 containing propolis extract is coated on the surface of the polyurethane foam 120.

The microcapsule 110 may be impregnated in the polyurethane foam 120 by generally known spraying or co-dipping. For one embodiment, the coating comprises: pretreating the polyurethane foam 120 by spraying an alcohol containing an expansion agent over the polyurethane foam 120 to thus enlarge the size of pore voids therein; spraying the microcapsule 110 over pretreated the polyurethane foam 120 or co-dipping pretreated the polyurethane foam 120 with the microcapsule 110; and drying spraying-treated or co-dipping treated the polyurethane foam 120.

For the pretreating, the alcohol may contain not only an expansion agent but also a hardening agent as necessary. Like this, treating the polyurethane foam 120 with an alcohol like ethanol causes the reaction between alcohol and polyurethane to foam and pore voids of the polyurethane foam 120 are expanded. Accordingly, expansion of pore voids in the polyurethane foam 120 makes the encapsulation of the microcapsule 110 into pore voids easier.

Actually, photos of the material sheet of the polyurethane foam 120 used in one embodiment of the present invention before and after the pretreating are taken and shown in FIG. 3. (The left in the first image is the material sheet magnified by a factor of 10,000 and the remaining images are the actual size of the material sheet.)

After performing the pretreating, spraying the microcapsule 110 over the polyurethane foam 120 having expanded pore voids or co-dipping the polyurethane foam 120 having expanded pore voids with the microcapsule 110 is performed to entrap the microcapsule 110 in the pore voids of the polyurethane foam 120.

Then, drying the spraying-treated or co-dipping treated polyurethane foam 120 makes the expanded pore voids restored to their original sizes. Here, a temperature condition during drying is not particularly limited, but preferably, drying carried out at a temperature from about 20^°C to about 80°C is favorable for restoring the pore voids to their original state.

In case that the antimicrobial pad 100 is manufactured for sterilizing a toilet seat having an antimicrobial pad, the polyurethane foam 120 may have pore voids ranging preferably from about 10 im to about 120 im, and more preferably from about 80 im to about 120 im- the polyurethane foam 120 consists of pore voids like this, so that it has a structure which al lows the microcapsule 110 to be easily entrapped into pore voids.

Where the size of pore voids of the polyurethane foam 120 is less than about 10 μ&, the microcapsule 110 may not be entrapped into pore voids and the antimicrobial effect may be deteriorated and where the size of pore voids of the polyurethane foam 120 is more than about 120 μκι, the microcapsule 110 may be coated into pore voids, but maybe leaked again, and the antimicrobial effect may be deteriorated.

Meanwhile, the antimicrobial pad 100 comprising a fixing binder 130 improving adhesiveness between the polyurethane foam 120 and the microcapsule 110 in order to increase the durabi 1 ity thereof is manufactured by the following manufacturing method.

Namely, a method for manufacturing an antimicrobial pad according to another embodiment of the present invention comprises: preparing a microcapsule 110 with propolis extract through a sol-gel process; and mixing a microcapsule 110 with a fixing binder 130 to prepare a mixed solution and coating the surface of a polyurethane foam 120 with the mixed solution.

The method for manufacturing an antimicrobial pad according to another embodiment of the present invention is different from that according to one embodiment described above in the coating the surface of the polyurethane foam 120 with the mixed solution of the microcapsule 110 and the fixing binder 130 and other operations are same in both methods.

The mixed solution of the microcapsule 110 and the fixing binder 130 may be impregnated in the polyurethane foam 120 by general spraying or co-dipping described above. One embodiment may comprise pretreating the polyurethane foam 120 by spraying an alcohol containing an expansion agent over the polyurethane foam 120 to thus enlarge the size of pore voids therein; spraying a mixed solution of the microcapsule 110 and the si lane coupling agent over pretreated the polyurethane foam 120 or co-dipping pretreated the polyurethane foam 120 with a mixed solution of the microcapsule 110 and the si lane coupling agent; and drying spraying-treated or co-dipping treated the polyurethane foam 120.

The pretreating is the same as described above, and after performing the pretreating, spraying the microcapsule 110 over the polyurethane foam 120 having expanded pore voids or co-dipping the polyurethane foam 120 having expanded pore voids with the microcapsule 110 is performed to entrap the microcapsule 110 in the pore voids of the polyurethane foam 120.

Then, drying the spraying-treated or co-dipping treated polyurethane foam 120 makes the expanded pore voids restored to their original sizes. The drying is the same as described above and detailed description thereof will be omitted.

In thi s manner , by coat ing the mixed solut ion containing the fixing binder 130 over the polyurethane foam 120 to thus strengthen the attachment between the polyurethane foam 120 and the microcapsule 110, leakage of the microcapsule 110 out of the pore voids may be prevented, and therefore, the durability of the antimicrobial pad 100 may be improved and the lifespan thereof lengthened. Here, a si lane coupling agent may be used for the fixing binder 130 as described above. Preferably, the microcapsule 110 may contain the propolis extract in an amount of from about 20,000 ppm to about 50,000 ppm. However, kinds of the fixing binder and the amount of propol is extracts are not limited thereto.

The antimicrobial pad 100 of the present invention is for sterilizing a toilet seat having an antimicrobial pad and may be particularly for use, but not limited to, as a toilet seat cover having an antimicrobial pad for bidet-installed toilet bowls and may be for various uses like filters for air cleaners.

In case that the antimicrobial pad 100 of the present invention is used for sterilizing a toilet seat having an antimicrobial pad, the antimicrobial pad 100 is attached to the toilet seat cover having an antimicrobial pad for a bidet-installed toilet bowel and used. The antimicrobial pad 100 attached to the toi let seat cover having an antimicrobial pad steri 1 izes the toi let seat having an antimicrobial pad by activating the antimicrobials 115 in the antimicrobial pad 100. Activating the antimicrobials 115 can be undertaken by operating one function, for example, heating or drying the toilet seat having an antimicrobial pad in the bidet when the toi let seat cover is laid on the toi let seat .

The antimicrobial pad 100 may also be a filter for an air cleaner as a form of non-woven fabric or polyurethane foam. The antimicrobials 115 which are impregnated in non-woven fabric or polyurethane foam may be released naturally or by strong winds of a fan.

Therefore, the antimicrobial pad 100 is a sort of air cleaning filter and performs a function of decimating fungi in dust filtered through non-woven fabric or polyurethane foam as well as a function of sterilizing fungi or bacteria in dust accumulated in HEPA filter.

Experimental Examples

Experimental Example 1. Manufacture of Antimicrobial Pad 100

The microcapsule 110 used in the present example was Bacto Liquid purchased from BioChemKorea Co. ,Ltd. The particle size of the microcapsule 110 used in the present example was from about 3 to about 10 m and propolis extract (100%) were contained in the microcapsule 110. The polyurethane foam 120 used in the present example had pore voids with average size of 100 .

The particle size of the microcapsule 110 may be from about 3 [m to about 10 im. Where the microcapsule 110 is formed in size of less than about 3 /an, the coating amount of antimicrobials 115 (propolis extracts) decreases and the antimicrobial effect may be deteriorated and the durabi lity of the microcapsule 110 may be weakened. In addition, where the microcapsule 110 is formed in size of more than about 10 im, preparation of the microcapsule 110 is difficult due to its processes. The durability was tested within the particle size range of the microcapsule 110 and the result was shown below in Table 1.

[Table 1]

From above Table 1, where the particle size of the microcapsule 110 was 1 jtffli less than the above range, the lifespan of an antimicrobial pad 100 was 30 days. However, where the particle size of the microcapsule 110 was 5 μχΆ within the above range with the same condition, the lifespan was 120 days or longer. As shown in Table 1, where the particle size of microcapsule is within the above range, the durability of the antimicrobial pad 100 was improved.

For the antimicrobial pad 100, the microcapsule 110 containing propolis extract was impregnated in the polyurethane foam 120 by spraying.

First , in order to entrap the microcapsule 110 into the polyurethane foam 120, pretreating the polyurethane foam 120 to expand pore voids therein was undertaken by spraying an ethanol mixture onto the polyurethane foam 120.

The ethanol mixture used herein was a solution consisting of 90 weight% of 40% ethanol dissolved in water, 7 weight% of an expansion agent (sodium bicarbonate), and 3 weight% of amine hardening agent and spraying ethanol mixture was performed at room temperature.

Then, the microcapsule 110 containing propolis extract was impregnated in the pretreated polyurethane foam 120 by spraying.

Herein, the microcapsule 110 was coated to be contained in the antimicrobial pad 100 in an amount of about 10 weight% based on total weight of the antimicrobial pad 100 and spraying the microcapsule 110 was performed at room temperature. Then, the surface-pretreated polyurethane foam 120 was dried for 60 min. at room temperature (20TC) to thus complete the manufacture of the antimicrobial pad 100. Thus prepared the antimicrobial pad 100 was used for sterilizing a toilet seat having an antimicrobial pad.

While using the same method for manufacturing an antimicrobial pad described above, the microcapsule 110 containing propol is extract was mixed with a fixing binder 130 and impregnated in the polyurethane foam 120 by spraying.

Namely, in order to increase the durabi lity of the antimicrobial pad 100, the antimicrobial pad 100 was manufactured by using the fixing binder 130. Here, the pretreating and drying were the same as described above.

However, the microcapsule 110 may be mixed with the fixing binder 130 to make a mixed solution and the mixed solution may be impregnated in the pretreated polyurethane foam 120 by spraying. Here, a si lane coupling agent may be used for the fixing binder 130 and the amount of the propol is extract contained in the microcapsule 110 may be from about 20,000 ppm to about 50,000 ppm. The durability of the antimicrobial pad 100 was tested with regards to the use of the fixing binder 130 and the amount of the propolis extract and the result was shown in Table 2.

[Table 2]

From Table 2, where nothing was treated in Test 3, the lifespan of the antimicrobial pad 100 was 30 days and where the amount of propolis extract was set within the above range in Test 2, the lifespan of the antimicrobial pad 100 was 15 days.

However, where the fixing binder 130 was used for manufacturing the antimicrobial pad 100 and the amount of the propolis extract was 30,000 ppm, within the range in Test 1, the lifespan of the antimicrobial pad 100 increased to 136 days or longer. As shown in Table 2, the antimicrobial pad 100 according to one embodiment of the present invention has excellent durability and long usable 1 ife by using the fixing binder 130 and control ling the amount of propol is extract to be within the above range.

Experimental Example 2. Antimicrobial Tests of Antimicrobial Pad

1) Halo Test (Visibility Test)

According to the halo test, an antimicrobial pad 100 manufactured for sterilizing a toilet seat having an antimicrobial pad was tested. The halo test condition was as follow: general agar medium, 24 hours or longer at 37 C for culture condition, the antimicrobial pad 100 of 10 cm or more in diameter, Escherichia coli ATCC 25922. The result was shown in FIG. 4.

As shown in FIG. 4, while the control group in which nothing was treated showed no antimicrobial activity, E. coli bacteria within the area of 0.5 to 1 cm apart from samples were all dead in the antimicrobial pad 100 according to the present invention and thus, the antimicrobial pad 100 according to the present invention showed very excellent antimicrobial activity.

2) Quantitative Test

For antimicrobial activity for the antimicrobial pad 100, quantitative test was performed. The test condition was as follow: general agar medium, 24 hours or longer at 37 C for culture condition, the antimicrobial pad 100 of 10 cm or more in diameter, Escherichia coli . Here, the tests were repeated three times (sample 1 to sample 3) and the results were shown in Table 3.

[Table 3]

From Table 3, control groups 1 to 3 in which nothing was treated showed no change in numbers of bacteria after treatment (5 min.) and there were no antimicrobial activity.

However, in tests 1 to 3, the results comparing the bacteria numbers before and after treatment of the antimicrobial pad 100 showed that the numbers of bacteria after 5 min. treatment of the antimicrobial pad 100 of the present invention decreased by 97% in sample 1, 100% in sample 2, and 95.5% in sample

3 compared to the numbers of bacteria before treatment of the antimicrobial pad

100. Accordingly, from Table 3, the antimicrobial pad 100 according one embodiment of the present invention had very excellent antimicrobial activity. 3) Antimicrobials Release Test of Antimicrobial Pad

Whether the antimicrobial pad 100 according to the present invention shows the antimicrobial activity over time at a specific temperature and at a specific distance was investigated. The antimicrobial pad 100 manufactured for steri 1 izing a toi let seat having an antimicrobial pad was tested for the present test .

E. coli bacteria were cultured as described in Test 1), 13 mm of space above the E. coli was left, and the antimicrobial pad 100 was placed above the plate for 12 hours at an ambient temperature of 40 . Antimicrobial activity was evaluated by comparing the numbers of bacteria. The experimental method and result were shown in FIG. 5.

From FIG. 5, the control group in which nothing was treated showed no antimicrobial activity. However, the test group above which the antimicrobial pad 100 of the present invention was placed on showed that the E. coli bacteria were largely eradicated, as shown in the photo. Therefore, the experimental group showed very excellent antimicrobial activity.

Meanwhile, a toilet seat having an antimicrobial pad according to an embodiment of the present invention will be described in detail with reference to FIGS. 6 to 8. As shown in FIG.6, a toilet seat 1 having an antimicrobial pad according to an embodiment of the present invention is a structure mounted on a toilet 2. Here, the toilet seat 1 has a structure which can be mounted on the upper part of the toilet 2.

The toilet seat 1 of the current embodiment comprises a toilet seat body 10 disposed on the toilet 2; and a toilet seat cover 30 connected to the toilet seat body 10. Herein, the toilet seat body 10 and the toilet seat cover 30 are connected to each other with a rotation unit 40.

In the current embodiment , a heating unit 11 may be instal led in the inner space of the toilet seat body 10 to heat the surface of the toilet seat body 10. In addition, the toilet seat body 10 may have an inner space for accommodating various parts for cleaning or using a bidet.

In addition, a nozzle assembly (not shown in the drawings) is installed in the inner space of the toilet seat body 10 to allow a nozzle unit 13 to go forward or backward while cleaning or using a bidet.

Meanwhile, the toilet seat 1 of the current embodiment includes a control unit 20 in one outside of the toilet seat body 10. Herein, the control unit 20 controls operations of the nozzle assembly, the nozzle unit 13, and the heating unit 11. The control unit may include a button unit 22 including a cleaning button, a bidet button, a drying button, and a sterilization button. In the current embodiment, the temperature of the heating unit 11 may be controlled through the control unit 20 and when the sterilization button of the control unit 20 is selected, the heating unit 11 may be operated for heating to a predetermined temperature (for example, 40^°C or higher).

In the current embodiment , the toi let seat cover 30 is rotatably connected to the upper part of the toilet seat body 10 through a rotary unit 40. An antimicrobial pad 100 is attached to the inner side of the toilet seat cover 30.

As described above, the antimicrobial pad 100 is a member in which the outward release of antimicrobials 115 is facilitated by a rise in temperature (for example, 40t: or higher) to sterilize the toilet seat 1 and the inner part of toilet 2.

Here, the antimicrobial pad 100 may have a double-sided adhesive tape in one side and then the double-sided adhesive tape may be attached and fixed to the toilet seat cover 30, or the antimicrobial pad 100 and the toilet seat cover 30 may be connected using various methods like using other adhesive. That is, methods for connecting the antimicrobial pad 100 and the toilet seat cover 30 are not limited.

In the current embodiment, the antimicrobial pad 100 may be attached to the whole inner side of the toilet seat cover 30 or a portion of the toilet seat cover 30 along the contour of the secondary battery 10 as shown in FIG. 6. That is, the shape of the antimicrobial pad 100 is not limited to those which are disclosed and shown in the current embodiment.

A method for sterilizing the toilet 2 in which the toilet seat 1 installed will be described in detail with reference to FIGS. 7 and 8.

First, the toilet seat cover 30 is laid on the toilet seat body 10 so that the antimicrobial pad 100 provided for the toilet seat cover 30 can face the toilet seat body 10. Then, a sterilization operation command is inputted to the control unit 20 connected to the toilet seat body 10.

In the toilet seat 1, if a sterilization operation command is inputted to the control unit 20, the heating unit 11 starts to operated and thus if the temperature of the toilet seat cover 30 reaches at 40°C or higher, pores 113 of a microcapsule 110 and a silica gel 111 which are impregnated in the antimicrobial pad 100 attached to the toilet seat cover 30 are expanded. Thus, the outward release of the antimicrobials 115 which are entrapped in the microcapsule 110 is facilitated.

While the released antimicrobials 115 are diffused into the toilet seat body 10 and/or the inner part of the toilet 2, the toilet seat body 10 and/or the toilet 2 contacting the antimicrobials 115 are sterilized by the antimicrobials 115. For a predetermined time, the above process is maintained, and when a sterilization stop command is inputted to the control unit 20, the operation of the heating unit 11 is stopped. Due to the stop of the operation in the heating unit 11, the temperature of the toilet seat cover 30 starts to decrease and the pores 113 of the silica gel 111 are restored to their original state.

Accordingly, the toilet seat 1 of the current embodiment can control the outward release of the antimicrobials 115 encapsulated in the microcapsule 110 by controlling the temperature of the antimicrobial pad 100 and the sterilization process of the toilet seat body 10 and/or the toilet 2 is stopped upon a decrease in temperature.

While the toilet seat 1 (such as a bidet) has been described in the embodiment, the antimicrobial pad 100 of the present invention can be used for various purposes such as for an air cleaner filter.

The above described exemplary examples are intended to be illustrative and not restrictive within al 1 aspects of the present invention. Therefore, many modifications and detailed practices of the present invention can be made from explanations incorporated in the specif i cat ion by those skilled in the art. All these modifications and variations should be considered to be within the scope and spirit of the invention as defined by the appended claims.

Particularly, in the present invention, the material which the microcapsule is coated thereon is explained as polyurethane foam, but this is merely one illustrative example and any material having pore voids therein or on the surface and thus the microcapsule can be attached thereto like polyurethane foam correspond to equivalents or substitutes of polyurethane foam which fall within the scope of the present invention.

While the present invention has been shown and described in connection with the exemplary embodiments, it will be apparent to those skilled in the art that modifications and variations can be made without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

[CLAIMS]

[Claim 1]

An antimicrobial pad comprising:

polyurethane foam having pore voids of a predetermined size; and a microcapsule which containing antimicrobials therein and is provided to be encapsulated within the pore voids of the polyurethane foam to coat the surface of the polyurethane foam.

[Claim 2]

The antimicrobial pad of claim 1, the microcapsule comprising:

silica gel having a hollow capsule shape with a particle size of from about 3 im to about 10 μχα^', and

the antimicrobials filled in the silica gel.

[Claim 3]

The antimicrobial pad of claim 2, the antimicrobials are propolis extract .

[Claim 4]

The antimicrobial pad of claim 2, wherein the silica gel has a structure in which pores are porous when the antimicrobial pad is heated, and the pores can be enlarged in order to faci 1 itate the outward release of the antimicrobials.

[Claim 5] The antimicrobial pad of claim 1, wherein the polyurethane foam has pore voids ranging from about 10 im to about 500 πι.

[Claim 6]

The antimicrobial pad of claim 1, wherein the polyurethane foam has pore voids ranging from about 10 i to about 120 μπι.

[Claim 7]

The antimicrobial pad of claim 1, wherein the polyurethane foam has pore voids ranging from about 80 (m to about 120 μπι.

[Claim 8]

The antimicrobial pad of any one of claims 1 to 7 further comprising: a fixing binder improving adhesiveness between the polyurethane foam and the microcapsule in order to increase the durability.

[Claim 9]

The antimicrobial pad of claim 8, wherein the fixing binder is a si lane coupl ing agent .

[Claim 10]

The antimicrobial pad of claim 8, wherein

the antimicrobials are propolis extract and

the microcapsule contains the propolis extract in an amount of from about 20,000 ppm to about 50,000 ppm.

[Claim 11]

A method for manufacturing an antimicrobial pad comprising operations of:

a) preparing a microcapsule with propolis extract through a sol-gel process; and

b) coating the surface of polyurethane foam with the microcapsule.

[Claim 12]

A method for manufacturing an antimicrobial pad comprising operations of:

a) preparing a microcapsule with propolis extract through a sol -gel process; and

b-1) mixing the microcapsule with a fixing binder to prepare a mixed solution and coating the surface of polyurethane foam therewith.

[Claim 13]

The method for manufacturing an antimicrobial pad of claim 12, wherein the fixing binder is a si lane coupling agent.

[Claim 14]

The method for manufacturing an antimicrobial pad of claim 11, the microcapsule contains the propolis extract in an amount of from about 20,000 ppm to about 50,000 ppm.

[Claim 15]

The method for manufacturing an ant imicrobial pad of any one of claims 11 to 14, wherein the propol i s extract are extracted through vacuum ultrasonic extract ion after removing beeswax from a beehive through hot water gravi ty separat ion.

[Claim 16]

The method for manufactur ing an ant imicrobial pad of any one of claims 11 to 14, wherein the microcapsule has a part icle si ze of from about 3 jwn to about 10 iM -

[Claim 17]

The method for manufacturing an ant imicrobial pad of any one of claims 11 to 14, wherein the polyurethane foam has pore voids ranging from about 10 im to about 500 [m.

[Claim 18]

The method for manufacturing an ant imicrobial pad of any one of claims 11 to 14, wherein the polyurethane foam has pore voids ranging from about 10 [Mi to about 120 μα.

[Claim 19]

The method for manufacturing an ant imicrobial pad of any one of claims 11 to 14, wherein the polyurethane foam has pore voids ranging from about 80 fjrn to about 120 ΙΜ·

[Claim 20]

The method for manufacturing an antimicrobial pad of any one of claims 11 to 14, wherein the microcapsule is prepared by emulsifying a mixed solution comprising propolis extracts, tetraethylorthosi licate (TEOS), and partially hydrolyzed si lane into a solution in which an acid or alkal i is dissolved therein and has polarity opposite to that of the propolis extract to cause a sol-gel process at the interface to thus encapsulate propolis extract.

[Claim 21]

The method for manufacturing an antimicrobial pad of any one of claims 11 to 14, wherein operation b) or b-1) is performed by spraying or co-dipping.

[Claim 22]

The method for manufacturing an antimicrobial pad of claim 11, wherein operation b) comprises:

pretreating the polyurethane foam by spraying an alcohol containing an expansion agent over the polyurethane foam to thus enlarge the size of pore voids therein;

spraying the microcapsule over the pretreated polyurethane foam or co-dipping the pretreated polyurethane foam with the microcapsule; and

drying the spraying-treated or co-dipping treated polyurethane foam.

[Claim 23]

The method for manufacturing an antimicrobial pad of claim 12, wherein operation b-1) comprises:

spraying a mixed solution of the microcapsule and the si lane coupling agent over the pretreated polyurethane foam or co-dipping the pretreated polyurethane foam with a mixed solution of the microcapsule and the si lane coupling agent; and

drying the spraying-treated or co-dipping treated polyurethane foam.

[Claim 24]

A toilet seat having an antimicrobial pad comprising:

a toilet seat body having a structure mounted in a toilet; and a toilet seat cover connected to the toilet seat body to be opened and closed and having an antimicrobial pad in which the outward release of antimicrobials is facilitated by a rise in temperature.

[Claim 25]

The toilet seat having an antimicrobial pad of claim 24, wherein one side of the antimicrobial pad is connected to the inner side of the toilet seat cover and the antimicrobial pad comprises:

polyurethane foam having pore voids; and

a microcapsule which containing antimicrobials therein, provided to be encapsulated within the pore voids of the polyurethane foam.

[Claim 26]

A toilet seat having an antimicrobial pad comprising:

a toilet seat body having a structure mounted in a toilet; and a toi let seat cover connected to the toi let seat body to opened and closed and having an antimicrobial pad coated with a microcapsule containing antimicrobials therein.

[Claim 27]

The toilet seat having the antimicrobial pad of claim 26, wherein one side of the antimicrobial pad is connected to the inner side of the toilet seat cover and the antimicrobial pad comprises polyurethane foam having pore voids and the microcapsule is provided to be encapsulated within the pore voids of the polyurethane foam.

[Claim 28]

The toilet seat having the antimicrobial pad of any one of claims 25 to 27, wherein the polyurethane foam has pore voids ranging from about 10 im to about 500 im.

[Claim 29]

The toilet seat having the antimicrobial pad of any one of claims 25 to 27, wherein the polyurethane foam has pore voids ranging from about 10 μκι to about 120 im-

[Claim 30]

The toilet seat having the antimicrobial pad of any one of claims 25 to 27, wherein the polyurethane foam has pore voids ranging from about 80 [m to about 120 [M .

[Claim 31]

The toilet seat having the antimicrobial pad of any one of claims 25 to 27, wherein the microcapsule comprises:

silica gel having a hollow capsule shape with a particle size of from about 3 [M to about 10 pm^', and

antimicrobials present in the silica gel.

[Claim 32]

The toilet seat having the antimicrobial pad of claim 31, wherein the antimicrobials are propolis extract.

[Claim 33]

The toilet seat having the antimicrobial pad of claim 31, wherein the silica gel has a structure having pores and

when the toilet seat cover is heated by a heating unit embedded in the toilet seat body, the pores can be enlarged in order to facilitate the outward release of the antimicrobials.

[Claim 34]

The toilet seat having the antimicrobial pad of any one of claims 25 to 27, wherein the antimicrobial pad further comprises:

a fixing binder improving adhesiveness between the polyurethane foam and the microcapsule in order to increase the durability.

[Claim 35]

The toilet seat having the antimicrobial pad of claim 34, wherein the fixing binder is a si lane coupling agent.

[Claim 36]

The toilet seat having the antimicrobial pad of claim 34, wherein the antimicrobials are propolis extract and the microcapsule contains the propolis extract in an amount of from about 20,000 ppm to about 50,000 ppm.

[Claim 37]

A method for sterilizing a toilet wherein the method comprises: operations of

a) inputting the sterilization operation to a control unit connected to the toilet seat body; and

b) heating a heating unit embedded in the toilet seat body by the operation of the control unit so that when the sterilization operation is inputted, the temperature of the antimicrobial pad is elevated to reach a predetermined point , antimicrobials are released from the antimicrobial pad and the released antimicrobials are diffused into the inner part of the toilet, and thus the toilet seat body and the toilet are sterilized by the antimicrobials.

[Claim 38]

The method for steri 1 izing a toi let of claim 37, wherein the control unit in operation a) is operated to perform the sterilization operation in a covered state in which the toilet seat cover is laid on top of the toilet seat body and may not perform the sterilization operation in a uncovered state in which the toilet seat cover is not laid on top of the toilet seat body.

[Claim 39]

The method for sterilizing a toilet of claim 37, further comprising operation c) stopping the operation of the heating unit to stop the release of antimicrobials from the antimicrobial pad after a lapse of a pre-set predetermined time or an input of the sterilization stop, after operation b).