CN1149039A - Antibacterial ceramics and production method thereof - Google Patents

Abstract

The purpose of the invention is to reduce the amount of metal used and to uniformly and firmly attach the antibacterial metal only on the surface of the ceramic through vapor deposition. Metals or metal compounds with antimicrobial activity are attached to the surface of ceramics such as tiles or sanitary ware by vapor deposition. Silver or silver oxide is vaporized by heating the silver or silver oxide in a kiln. In the cooling zone the steam contacts the ceramic to deposit it on the ceramic. The silver or silver oxide can be heated by high temperature or heaters in the kiln. The silver or silver oxide may be contained in a container, preferably a porous container, which is placed in the kiln.

Description

Antibacterial ceramics and production method thereof

The invention relates to an antibacterial ceramic with antibacterial effect and a production method thereof. In particular the invention relates to ceramics on which metals such as silver are deposited by vapor deposition.

When bacteria attach to the surface of ceramics such as tiles and sanitary pottery, the proliferation of bacteria is accelerated due to the nourishment of stains and stains so that the surface tends to become dirty and unhygienic. Therefore, someone has developed ceramics with antibacterial effects.

Conventionally, an antibacterial effect is provided to the surface of ceramics by spraying a photocatalyst (anatase TiO ₂ ) or applying an antibacterial metal on the surface or applying a glaze in which an antibacterial metal is mixed and then baking the ceramic.

However, when the antimicrobial metal is mixed with the glaze, the metal diffuses throughout the glaze. That is, although the part necessary to provide the antibacterial effect is only on the surface, the metal is uniformly diffused therein so that the metal is used more. In addition, the metals used in this way are usually expensive metals such as copper or silver, thus making the ceramics expensive. On the other hand, in the method of spraying the antibacterial metal, it is impossible to uniformly apply the metal or metal compound to the surface of the ceramic and it is difficult to match the surface configuration of the ceramic. When the metal or the metal compound is sprayed before baking the ceramic, the metal or the metal compound is sometimes blown off during the baking so that the ceramic has no antibacterial effect. On the other hand, when the metal or metal compound is sprayed after baking the ceramics, the metal or metal compound tends to come off.

The present invention has been made in consideration of the above problems. It is an object of the present invention to provide antibacterial ceramics which can be manufactured using a small amount of antibacterial metal such as silver by firmly and uniformly fixing the antibacterial metal only on the surface of the ceramic, thereby also reducing the cost. The antibacterial ceramic of the present invention is characterized in that the metal or metal compound having antibacterial effect is fixed on the surface of ceramic such as tile or sanitary pottery by vapor deposition.

Ceramics are produced by vaporizing metals or metal compounds with antimicrobial activity and depositing metals or metal compounds on the surface of ceramics such as tiles or sanitary ware.

Ceramics are preferably produced at atmospheric pressure.

Vapor deposition is preferably performed at a temperature below 1300°C.

According to one aspect of the present invention, the metal or metal compound having antibacterial effect is filled in one or more reservoirs of porous ceramics and vaporized through the reservoir so that the metal or metal compound is attached to ceramics such as tiles by vapor deposition. or the surface of sanitary ware.

The receptacle may be a hollow roller so that the antimicrobial metal or metal is filled in the hollow roller.

The hollow rollers can be some conveying rollers that convey ceramics such as tiles and sanitary ware to the kiln for baking, and the ceramics are on the conveying rollers.

Receptacles can be inserted from the side walls of the kiln and arranged horizontally with ceramics such as tile and sanitary ware.

The receptacle can be rotated in the kiln.

Fig. 1 is a schematic diagram showing that metal or metal compound is deposited on the tile by vapor deposition in a roller kiln according to the first scheme;

Figure 2 is an enlarged sectional view of the tile;

Fig. 3 is the schematic structural view that represents according to the second scheme metal or metal compound is deposited on the tile situation by vapor phase deposition in the roller kiln;

Fig. 4 is the schematic structural diagram of the third scheme, wherein baking and depositing are carried out simultaneously in the roller kiln;

Fig. 5 is a schematic structural diagram of the fourth scheme, wherein baking and deposition are carried out simultaneously in the roller kiln;

Figure 6 is a perspective view showing an example of the reservoir shown in Figure 7;

Figure 7 is a perspective view showing a roller kiln, wherein a receptacle is inserted from a side wall of the roller kiln;

Figure 8 shows a perspective view of a fifth option, in which a roller kiln has transfer rollers arranged therein and metallic silver for deposition is filled in some of the rollers;

Figure 9 shows a schematic diagram of the sixth option, wherein the tiles in each sagger placed on the kiln car are baked and deposited;

Fig. 10 is an enlarged structural view showing the inside of the sagger; and

Figure 11 is a schematic diagram showing a seventh variant in which the baking and deposition of the tiles are carried out simultaneously in a batch kiln.

In the following, aspects of the present invention are described with reference to the drawings.

Fig. 1 is a schematic diagram of the first scheme, in which silver ions are deposited on the surface of each tile by vapor deposition when the tiles are fed into a roller kiln and baked. The roller kiln 1 is equipped with a plurality of rollers 2 which are rotatably aligned in the roller kiln 1 from its entrance to its exit. The axis of each roller 2 extends horizontally and is perpendicular to the loading direction of the tile blank. Each roller 2 is made of refractory material. All rollers are rotated by electric motors. According to the direction of rotation of the rollers 2, the tiles 3, 3, 3 are fed from the entrance of the roller kiln and reach the exit. In the roller kiln 1 the respective tiles 3 are efficiently heated in a preheating zone 11 , baked in a firing zone 12 and then cooled in a cooling zone 13 . The temperature of the firing zone 12 in the roller kiln 1 is preferably greater than 1000°C and less than 1400°C, more preferably greater than 1100°C and less than 1300°C.

Silver metal round rods 4 are also equipped at the cooling zone 13 in the roller kiln 1 . The silver is vaporized from the round rod 4 so that the vaporized silver is deposited on the surface of each tile 3 at the cooling zone 13 . The temperature in the area where the silver metal round rod 4 is placed in the cooling zone 13 is preferably greater than 600°C and less than 920°C, more preferably greater than 800°C and less than 900°C. At this temperature, a large amount of silver can be vaporized from the round rod 4 . Silver is effectively deposited on the surface of the tile 3 when the round rod 4 of silver is located 1-50 mm, preferably 2-10 mm, from the tile surface. Although only one round bar 4 is arranged in the above, many round bars 4, 4 may be arranged. The diameter of the round rod 4 is preferably greater than 5 mm and less than 80 mm, more preferably greater than 20 mm and less than 50 mm.

As mentioned above, since the cooling zone 13 has a temperature range of 600°C to 900°C so that the atmosphere of the cooling zone 13 contains vaporized silver at a low density, silver can be deposited very thinly on the surface of the tile 3 in such a temperature range of the cooling zone 13 superior. Since the cooling zone 13 has a lower temperature close to the outlet temperature of the roller kiln 1, the silver deposited on the surface will not re-vaporize. The amount of silver deposited on the surface of tile 3 is preferably between 0.01 mg and 0.50 mg, more preferably between 0.05 mg and 0.20 mg per 1 m ² of tile 3 surface.

As shown in the cross-sectional view of the tile in FIG. 2, silver is uniformly deposited on the surface of the glaze layer 3b on the blank 3a of the tile 3, thereby enhancing the antibacterial effect of the tile 3 surface. It is thus possible to give the tile 3 an improved appearance in which trace amounts of silver are deposited on its surface without changing the color of the glaze 3b. By changing the feeding speed of the tile 3, the amount of silver Ag deposited on the surface of the tile 3 can be controlled.

As described above, according to this scheme, silver is deposited only on the surface of the glaze layer 3b, thereby reducing the amount of silver diffused into the interior of the glaze layer 3b and the total amount of silver, and compared with the previous mixed silver and glaze Compared with conventional methods, the cost of manufacturing tiles is low. Since the silver is firmly attached to the surface of the tile 3, there is no trouble of the silver coming off the surface. Therefore, silver has an antibacterial effect on the surface.

It should be noted that even when the tile 3 has an uneven surface, the silver is deposited substantially uniformly on the surface matching its unevenness.

Although there is a glaze layer 3b on the tile 3 in FIG. 2, silver Ag can be directly deposited on the surface of the tile 3a without using a glaze.

Referring to Fig. 3, a second scheme is described.

The roller hearth kiln 1 is equipped in a cooling zone 13 with a container 4 such as a crucible, into which silver oxide is filled. The container 4 is attached to a heater such as a high frequency heating device or an electron beam heating device. The silver is oxidized to silver metal by pyrolytic oxidation at the temperature of the cooling zone 13 . The silver is heated with a heater so that the silver is vaporized from a container 4 such as a crucible and then deposited on the surface of each tile 3 by vapor deposition. The temperature of the area where the container 4 is placed in the cooling zone 13 is preferably greater than 700°C and less than 1100°C, more preferably greater than 800°C and less than 1000°C. Therefore, the atmosphere in the cooling zone 13 contains vaporized silver at a low density, enabling very thin deposition of silver on the surface of the tile 3 .

Then, since the silver is deposited substantially uniformly on the surface of the tile 3, the silver Ag adheres firmly and partially to the surface of the tile 3, thereby improving the antibacterial effect of the surface of the tile 3. It is thereby possible to give the tile 3 an excellent appearance without changing the color of the glaze 3b.

Fig. 4 shows a third scheme, wherein when the tiles 3 are continuously fed into the roller kiln 1, frame bricks 5 (refractory brackets) on which silver oxide 6 is placed are also fed into the roller kiln 1. The silver oxide 6 is converted into silver by pyrolysis in the roller kiln 1, and then the silver is heated to vaporize so that the atmosphere of the roller kiln 1 contains the vaporized silver. Therefore, silver is uniformly deposited on the surfaces of the tiles 3, 3 fed into the roller 2.

During the feeding of the silver oxide 6 and the tiles 3 into the roller kiln 1, the vaporized silver effectively provides silver on the surface of each tile and the silver is deposited substantially uniformly and locally on the surface. It is thus possible to improve the antibacterial effect on the tile surface by effectively attaching the reduced amount of silver only to the surface.

FIG. 5 shows a fourth variant in which the roller kiln 1 has a number of receptacles 7 in sections from the end of the firing zone to the cooling zone of the roller kiln 1 . In this solution, each receptacle 7 is made of a hollow roller filled with silver metal and silver oxide 8, as shown in the perspective view of FIG. 6 . Both ends of the hollow roller 7 are sealed by rids. The hollow roller 7 is made of porous ceramics such as mullite, each pore has a diameter of less than 500 μm, preferably between 0.1 μm and 100 μm.

This hollow roller 7 is inserted into the roller kiln from the side wall 9 of the roller kiln and placed horizontally at a position of 1-60 cm above the tile 3 that is sent into the kiln, preferably 5-10 cm, the roller 7 is installed in the kiln On the side wall 9, as shown in Figure 7. The hollow roller 7 can rotate appropriately. Silver metal or silver oxide 8 vaporizes and diffuses into the kiln through the pores of the hollow roller 7 ceramic and deposits on the surface of the tile 3 .

The diameter of each roller 7 is preferably greater than 10 mm and less than 50 mm, more preferably greater than 20 mm and less than 30 mm. The wall thickness of each roller 7 is preferably greater than 1 mm and less than 10 mm, more preferably greater than 2 mm and less than 4 mm. The number of rollers 7 is greater than 1 and less than 20, more preferably greater than 5 and less than 15, and the distance between them is preferably 10-100 cm, more preferably 20-50 cm.

Because the hollow roller 7 is placed horizontally and the roller is installed on the side wall 9 of the kiln, the hollow roller 7 can be properly replaced outside the side wall 9 so that it can be continuously fed into the kiln without interruption when the hollow roller 7 is replaced. The deposition operation of tile 3. Rotating the hollow roller 7 prevents bending of the hollow roller. The porous ceramic of the hollow roller 7 can be previously impregnated with silver metal in order to allow successful diffusion deposition of the silver metal Ag on the tile 3 .

Although in this embodiment, the hollow roller is illustrated as the reservoir 7, the reservoir may be formed in other configurations such as a groove shape with an open upper end. This receptacle, filled with silver metal Ag, can also have the same effect.

Fig. 8 shows a fifth option, in which the roller kiln 1 has a plurality of rollers 2 rotating in a line, some of which are rollers 2A placed at the exit portion of the firing zone. Each roller 2A contains silver metal rods, silver metal powder or silver oxide therein.

Each roller 2A is made of porous ceramics such as mullite and forms a hollow structure with a diameter of eg 20-40 mm. The roller 2 is inserted into the kiln by rotating from the side wall of the roller kiln 1, and the roller is installed on the side wall, so it is convenient to add silver metal Ag to the roller 2A by taking out the roller 2. The silver metal or silver oxide filled in the roller 2A is vaporized and diffused upward in the kiln by air circulation and deposited on the surface of the tile 3 .

The tiles 3 are conveyed from the kiln inlet to the outlet by means of rollers 2 placed in the roller kiln 1 , the tiles 3 on the rollers 2 . During this process, silver metal Ag is continuously vaporized from the rotating roller 2A to be diffused and deposited on the tile 3 by air circulation. There is no need to change the structure of the conventional roller kiln 1 .

Figures 9 and 10 show a sixth variant in which a kiln 20 has a number of kiln cars 21 on which a large number of saggers 22 are stacked. Each sagger 22 includes many tiles 3 arranged in an upright state as shown in FIG. 10 . In this scheme, tiles are placed in pairs with their backs touching each other. The sagger 22 contains silver oxide. The amount of silver oxide in each sagger 22 is preferably between 0.5 g and 20 g, more preferably between 5 g and 10 g per 1 cm 2 of the face of the tile 3 placed in the sagger 22 .

As mentioned above, in the process of conveying the kiln car 21 from the entrance to the exit of the kiln 20, on which many saggers 22 are stacked and tiles 3, 3, 3 stand upright in each sagger 22, the kiln car 21 is fired Zone 25 is heated to a temperature between 1000° C. and 1400° C., preferably between 1100° C. and 1300° C., so that silver oxide 23 is vaporized in sagger 22 as shown in FIG. 10 and the vaporized silver is subsequently deposited on vertical tiles 3 on the front.

According to this scheme, during the transfer of the tile 3 through the preheating zone 24, the firing zone 25 and the cooling zone 26 of the kiln, silver is deposited on the front side of the tile 3 while the tile 3 is being baked, so that by simultaneously firing And deposition to make antibacterial tiles at low cost.

Fig. 11 shows the seventh scheme, wherein the intermittent kiln 30 is equipped with many stacked small platforms 31 on which tiles 3, 3, 3 are respectively placed, and silver oxide pieces 32, 32, 32 are respectively placed on the bottom and top of the kiln. Most tables are 31. When the interior of the kiln 30 is heated to a temperature between 1000°C and 1400°C, more preferably between 1100°C and 1300°C to bake tiles, the silver oxide lumps are vaporized by pyrolysis to diffuse in the batch kiln 30 and this Vaporized silver oxide is deposited on the front side of the tile 3 . Silver Ag is uniformly deposited on the surface of the glaze layer of each tile, so a tile having a highly effective antibacterial effect on its surface is produced.

In the above schemes the baking and deposition are described in a kiln maintained at atmospheric pressure, however, silver can be effectively deposited on the tile faces even when the kiln is in a pressurized or vacuum or reduced pressure atmosphere.

For tiles, the deposition of silver is not limited and can be done in the same manner as above on ceramics such as other sanitary ware and enamelled bathtub surfaces. In addition, zinc, copper or combinations thereof can be used instead of silver as deposited antimicrobial metals. In addition, metal compounds of silver, zinc or copper such as silver nitrate, silver phosphate and silver chloride can be used as deposited antimicrobial metals. The metal or metal compound having antibacterial activity is firmly and uniformly deposited only on the surface of the ceramic, so that a ceramic having a highly effective antibacterial effect is produced.

In the present invention, since the metal or metal compound having antibacterial activity is firmly and uniformly deposited only on the surface of the ceramic by vapor deposition, the ceramic surface has an improved antibacterial effect due to the thus deposited metal or metal compound. Bacteria multiplication by metal ions is thus effectively prevented even when bacteria are on the surface. That is, the ceramics treated as above can have an antibacterial effect, an antimold effect and a deodorizing effect.

In the production method of the present antibacterial ceramics, wherein a metal or metal compound having antibacterial activity is vaporized and deposited on the surface of ceramics such as tiles and sanitary ware, the metal or metal compound is vaporized in a kiln for baking the ceramics and the vaporized metal or metal The compound is deposited uniformly and firmly on the surface of the ceramic. Therefore, the metal or metal compound can be effectively fixed on the ceramic surface and the amount of vaporized metal or metal compound can be easily controlled.

Because the production of antibacterial ceramics is carried out under atmospheric pressure, metal or metal compounds can be deposited on the surface of the ceramics by vapor deposition in the kiln during the firing of the ceramics.

The metal or metal compound can be vaporized and deposited on the surface of the ceramic in the normal temperature range of the kiln so that the baking of the ceramic and the deposition of the metal or metal compound on the ceramic surface can be carried out simultaneously, thereby reducing the production cost of the ceramic.

When a metal or metal compound having antibacterial activity is filled in a reservoir of porous ceramics and vaporized and diffused through the reservoir so that the vaporized metal or metal compound can be deposited on the surface of ceramics such as tiles or sanitary ware, the metal or metal compound can Diffusion effectively through the pores of the porous ceramic so that the fine particles of metal or metal compound are vapor-deposited on the surface of the ceramic, thus becoming a firm and efficient deposit.

When the reservoir is a hollow roller and the metal or metal compound having antibacterial activity is filled in the hollow roller, the metal or metal compound is completely vaporized and diffused from the surface of the hollow roller, thus improving workability.

The hollow rollers are some conveying rollers that are originally placed in the roller kiln to convey ceramics such as tiles and sanitary pottery baked in the kiln. During the process of ceramics, the fine particles of metal or metal compounds are vaporized from the rotating rollers and diffused effectively in the kiln through air circulation so that the metal or metal compounds can be effectively deposited on the surface of the ceramics by conveying the rollers without changing the conventional roller table. The structure of the kiln and other devices are not required.

The receptacle is arranged horizontally above ceramics such as tiles and sanitary ware from the side wall of the kiln, and the receptacle is mounted on the side wall, thus enabling proper replacement of the receptacle from the outside of the kiln side wall. Thus, reservoir replacement can be performed without interrupting the continuous deposition.

By rotating the receptacle in the kiln, bowing of the receptacle is prevented, so continuous deposition can also be efficiently performed.

Example Example 1

Use the roller kiln described in Figure 1 to prepare antibacterial ceramic tiles with a size of 15cm×15cm×0.7cm, and the detailed data are as follows:

Internal volume of the kiln: 22m ³

Length of preheating zone 11: 8m

The length of firing zone 12: 12m

Length of cooling zone 13: 16m

Number of burners: 27

Diameter of silver rod 4: 30mm

Length of silver rod 4: 2m

The conveying speed of the roller: 108m/Hr

Kiln residence time: 21 minutes

Firing temperature: 1300°C

16 mg of silver were deposited on the tiles thus prepared. Example 2

Antimicrobial ceramic tiles with the same dimensions as above were prepared using the roller kiln described in Figure 3.

The container had a volume of 1000 cm ³ and silver oxide was contained therein so that approximately 100 cm ² of oxide was exposed to the atmosphere in the kiln. The container was placed in an area with a temperature of 1200°C.

Silver oxide was consumed at a rate of 0.3kg/Hr.

16 mg of silver were deposited on the tiles thus prepared. Example 3

Antimicrobial ceramic tiles with the same dimensions as above were prepared using the roller kiln described in Figure 4.

The size of the frame brick is 15cm×15cm, which is the same size as the tile. Every 30 tiles have a frame brick and are sent into the kiln, and the tiles are arranged in a line in batches. The amount of silver oxide placed on each frame brick is about 20g.

16 mg of silver were deposited on the tiles thus prepared. Example 4

Antimicrobial ceramic tiles having the same dimensions as above were prepared using the roller kiln described in Figure 5.

The receptacle is loaded in a zone where the temperature in the kiln is 1000 to 1100°C. The reservoirs are separated by 50 cm from each other and located 10 cm above the tiles. Each hollow roller reservoir has a diameter of 35 mm, a length of 3000 mm, and a thickness of 6 mm: the reservoir is made of mullite with a porosity of 25%.

The silver oxide in the hollow reservoir was consumed at a rate of 0.3 kg/Hr.

16 mg of silver were deposited on the tiles thus prepared. Example 5

Antimicrobial ceramic tiles having the same dimensions as above were prepared using the roller kiln described in FIG. 8 .

The kiln is equipped with fifteen hollow rollers 2A in a zone with a temperature of 1000 to 1100°C. Each roller 2A has a diameter of 25 mm, a length of 3000 mm, and a thickness of 2 mm. The rollers 2A are made of mullite having a porosity of 25% and containing silver oxide therein, and the rollers 2A are separated from each other by approximately 90 cm.

Silver oxide was consumed at a rate of 0.3kg/Hr.

16 mg of silver were deposited on the tiles thus prepared. Example 6

Antimicrobial ceramic tiles having the same dimensions as above were prepared using the kiln described in FIG. 9 .

The saggers are stacked 12 layers.

The sagger has a volume of 30 x 30 x 12 cm and contains 50 tiles and 5 g of silver oxide. 480 saggers are sent into the kiln every hour.

7 mg of silver were deposited on the tiles thus prepared. Example 7

Antimicrobial ceramic tiles with dimensions of 10 cm x 10 cm were prepared using a kiln with a volume of 1 ^m3 as described in FIG. 11 . 2000 tiles were deposited with silver in each batch in the kiln. In each batch, the consumption of silver oxide was 0.3 kg. It took 10 hours to raise the temperature in the kiln from room temperature to 1000°C, keep the same temperature for 1 hour, and then lower the temperature.

7 mg of silver were deposited on the tiles thus prepared.

Claims (12)

1. anti-bacteria ceramic, wherein have the metal of anti-microbial activity or metallic compound by the gas deposition firm attachment pottery as watt or the surface of sanitary ware on.

2. the production method of an anti-bacteria ceramic, it comprise that vaporization has the metal of anti-microbial activity or metallic compound in case the metal of this vaporization or metallic compound by gas deposition attached to pottery as watt or the lip-deep step of sanitary ware.

3. the production method of the described anti-bacteria ceramic of claim 2, wherein said vapour deposition is to carry out under barometric point.

4. the production method of the described anti-bacteria ceramic of claim 2, wherein said vapour deposition are in decompression or add to depress and carry out.

5. the production method of any one the described anti-bacteria ceramic in the claim 2,3 and 4, wherein said have in the metal of anti-microbial activity or the storage that metallic compound is filled in one or more porous ceramicss and by this storage vaporization so as by gas deposition metal or metallic compound attached to pottery as watt or the surface of sanitary ware on.

6. the production method of the described anti-bacteria ceramic of claim 5, wherein said storage is that hollow roller and said metal or metallic compound with anti-microbial activity are filled in the said hollow roller.

7. the production method of the described anti-bacteria ceramic of claim 6, wherein said hollow roller be some potteries that are used for being transmitted in baking in the kiln as watt or the transfer roller of sanitary ware.

8. the production method of claim 5 and any one described anti-bacteria ceramic of 6, wherein said storage from the kiln abutment wall insert and lie in a horizontal plane in pottery as watt or sanitary ware above.

9. the production method of claim 6 and any one described anti-bacteria ceramic of 8 also is included in the step of the said storage of rotation in the kiln.

10. the production method of claim 8, wherein said kiln be roller kiln and said storage be placed on be transmitted pottery that roller transmits directly over.

11. the described production method of any one of claim 2 to 10, wherein said metal are silver.

12. the described production method of any one of claim 2 to 10, wherein said metallic compound is a silver suboxide.

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