Method for stainproofing treatment and product having glass layer, reinforced pottery and method for production thereof, and product having glass layer and method for production thereof

The invention relates to an article having a glass layer and a method of making an article having a glass layer.

State of the art

It is known that certain metals, e.g. Ag, Cu, Zn etc., have an antimicrobial effect. Therefore, in the case where an article having a glass layer is to be manufactured, such as a ceramic article, glazed article, etc., with antimicrobial properties, an anti-stain treatment process is performed which includes an antimicrobial treatment step imparting an antimicrobial effect to the surface of the base body. , such as glass molded article, ceramic molded article, metal molded article, etc. The antimicrobial treatment step of the anti-stain treatment process comprises a glaze material preparation step for forming a glass layer containing the antimicrobial metal, and a vitrification step to form a glaze material layer formed on the surface of the base body, and melting the glaze material layer to form a glass layer.

According to this anti-stain treatment process, a product is obtained which comprises a base body with a glass layer, and the glass layer comprises a glaze material. In a product having the glass layer obtained in this way, the antimicrobial metal in the glass layer may kill bacteria or limit their multiplication.

A conventional ceramic product comprises a ceramic main body and a glass layer formed on the surface of the ceramic main body.

A ceramic product is roughly manufactured as follows. In the preparatory step, a base material that can form a ceramic main body and a glaze material that can form a glass layer on the surface of the ceramic main body are prepared. In the glazing step, the material layer of the enamel is formed on the surface of the base material. Then, in a firing step, the base material and the glaze material layer are fired to obtain a ceramic product comprising a ceramic main body and a glass layer.

In the thus obtained ceramic product, the glass layer is finished to obtain a smooth and precise surface and makes the surface difficult to damage and water resistant.

In addition, the ceramic materials used as articles, such as tableware, kitchenware, decorative products, tiles, sanitary ware, electrical equipment, physical and chemical appliances, industrial equipment, roof tiles, ceramic pipes, etc., include a ceramic main body as the base body and a glass layer formed on the surface of the ceramic main body. The glazed product comprises a metal main body as the base body and a glass layer formed on the surface of the metal main body. Moreover, some of the glassware comprises a glass main body as the base body and a glass layer formed on the glass main body.

Among the above articles having a glass layer, ceramic material is roughly produced as follows, for example. In the preparatory step, a base material that can form a ceramic main body and an enamel material that can form a glass layer on the surface of the ceramic main body are prepared. In the glazing step, an enamel layer containing the glaze material is formed on the surface of the base material. Then, in a firing step, the base material and the glaze material layer are fired to obtain a ceramic product comprising a ceramic main body and a glass layer. In this product, the glass layer is finished to a smooth and precise surface that is stain-resistant and waterproof.

The essence of the invention

Since only one glass layer is formed on the surface of the base body by the usual anti-staining treatment process, it is naturally expected to impart an antimicrobial effect to the surface of the glass layer, but the antimicrobial metal is dispersed in this glass layer. Therefore, in an article having the glass layer thus obtained, its performance is weak, unless the concentration of the antimicrobial metal is increased. The anti-stain treatment process uses a large amount of antimicrobial metal to obtain an excellent antimicrobial effect, thereby increasing the manufacturing cost.

PL 205 186 B1

A conventional product having a glass layer is prone to blemishes on its surface and its surface hardness is insufficient because the glass layer is a single layer. It therefore has the disadvantage that the glass layer is prone to breakage on impact due to these flaws. It is also a disadvantage that the stain tends to attach to these blemishes. It is therefore contemplated to use multiple layers of glass. However, it has been found that an article using simply a multi-layer glass layer is still prone to scorch and its surface hardness is insufficient. It therefore has the disadvantage that it is not stain resistant.

The invention has been developed under the circumstances of the prior art, and its aim is to obtain an article having a layer of glass which is hardly blemished on the surface and therefore certainly has excellent stain resistance.

An article having a glass layer according to the invention comprises a base body and a glass layer formed on the surface of said base body, and is characterized in that the glass layer comprises a first glass layer comprising a first glaze material and a second glass layer comprising a second glaze material, the second layer being formed on the outer side of the first layer of glass and contains antimicrobial metal and fine hard particles of zircon, which are dispersed over the surface of the second glass layer, the mean diameter of the fine zirconium particles being not less than 0.8 µm.

In an article having a glass layer according to the invention, it is preferred that the second glass layer has a lower linear thermal expansion coefficient than the first glass layer.

It is also preferred that the main body has a greater linear thermal expansion coefficient than the first glass layer.

According to this configuration, not only the second glass layer receives compressive stress from the first glass layer, but also the first glass layer receives compressive stress from the base body through the base body sintering process, the glaze material layers melting process and the cooling process of the base body and glass layers in the firing step as a result of which not only the second layer of glass is compacted, but also the first layer of glass. Therefore, in a product having a glass layer according to the invention, it is difficult for the glass layer or the like to form cracks.

It is preferred that the base body and the first glass layer have a linear thermal expansion coefficient value difference in the range of 1 x 10^-7 up to 1 x 10^-6/ ° C. In case the difference in the value of the thermal expansion coefficient between the base body and the first glass layer is below this range, the desired strength cannot be obtained, and on the other hand, when the difference is above this range, the compressive stress perceived by the first glass layer from the base body becomes too large to cause the first layer of glass to break. In particular, according to the results of the experiments carried out by the inventors, it is practical if the base body and the first glass layer have a linear thermal expansion coefficient value of 2 × 10^-7 up to 5 x 10^-7/ ° C.

An article having a glass layer according to the invention may have three or more layers of glass on the base body. For example, if it has three glass layers, then the interlayer corresponds to the first glass layer and the top layer corresponds to the second glass layer.

As fine hard particles used in the article with the glass layer according to the invention, metal fine particles and fine particles of inorganic material such as zirconium fine particles and the like may be used. These fine hard particles preferably have an average diameter of 0.8-20 .mu.m. According to this configuration, excellent scorch resistance is demonstrated and the good appearance of an article having a glass layer can be maintained.

According to the results of the experiments carried out by the inventors, it is preferable to use fine zirconium particles. The nature of the fine zirconium particles is that they are harder than the blemishes on the surface of the second glass layer. The brush and the abrasives used for cleaning are considered to be such factors. Such factors are abraded by fine zirconium particles, so it is difficult for them to blemish the second glass layer.

The fine zirconium particles provide scorch resistance as described above, but on the other hand they deteriorate the surface smoothness of the second glass layer and color the second glass layer depending on their content in the second glass layer. The content of the fine zirconium particles in the second glass layer is therefore preferably 0.5-2% by weight.

PL 205 186 B1

According to the results of the inventors' experiments, in an article having a glass layer according to the invention, the second glass layer contains a greater amount of potassium and a lower amount of sodium than the first glass layer. Potassium has a larger ion radius than sodium. Therefore, it is believed that after the glass layers of an article having the glass layer according to the invention are formed, the sodium ions in the second glass layer are replaced by potassium ions in the first glass layer to create a compressive stress in the second glass layer, thereby increasing the strength of the second glass layer. .

An article having a glass layer according to the invention has a high stain resistance when an antimicrobial metal is included in the second glass layer. In particular, in an article having a glass layer according to the invention, since the antimicrobial metal is contained only in the second glass layer of the glass layers, the concentration of the antimicrobial metal on the surface side can be increased, even if a smaller amount of antimicrobial metal is used than in the conventional article. get a stronger antibacterial effect. In addition, unnecessary consumption of the antimicrobial metal can be avoided.

As the antimicrobial metal contained in the second enamel material, Ag, Cu, Zn etc. can be used. Specific examples include an organic silver or copper compound and an inorganic silver or copper supporting compound, and (1) silver, copper, and a silver-copper alloy; (2) silver phosphate, silver nitrate, silver chloride, silver sulfide, silver oxide, silver sulfate, silver citrate and silver lactate; (3) cuprous phosphate, cupric phosphate, organic copper compound, cuprous chloride, cupric chloride, cuprous sulfide, cuprous oxide, cupric oxide, cupric sulfide, cuprous sulfate, cupric sulfate, copper citrate, and copper lactate, etc. As for zinc, likewise the organic zinc compound and the inorganic zinc compound as well as zinc, zinc oxide, zinc chloride, zinc sulphide, zinc sulphate, zinc lactate, etc. are exemplified. These antimicrobial metals can be in the form of an elemental substance or an alloy, or also in the form of a compound.

A method of manufacturing an article having a main body of a ceramic product and a glass layer formed on a surface of the body, the method comprising: the step of preparing the main body of the ceramic product and the glaze material suitable to form a glass layer on the surface of the body, the step of forming a glass layer comprising the glaze material on the surface of the main body of the ceramic product, and the step of firing the main body of the ceramic product and the glaze material layer is characterized by that is formed on the main body of the ceramic product with a first glass layer comprising the first glaze material, by molding a first glass layer and then a second glass layer is formed on the outside of the first glass layer on the outside of the first glass layer, an antimicrobial metal and fine zirconium particles are added to the second glaze material and dispersed on the surface of said second glass layer, wherein the mean diameter of the fine particles of zirconium is not less than 0.8 μm.

By the method of the invention, an article having the glass layer of the invention can be produced.

In the method for producing an article having a glass layer according to the invention, it is possible in the glazing step that a first glaze material layer is formed and then a second glaze material layer is formed on the first glaze material layer. In the thus obtained article having the glass layer according to the invention, the first glaze material is introduced into the surface of the base body when the first glaze material is applied to the base body to form the first glaze material layer, and further the first glaze material which has penetrated the base body forms. also the first glass layer inside the base body. Thereby the first glass layer is firmly adhered to the base body. Further, in the base body, since the second glaze material is applied over the first glaze material layer to form a layer of the second glaze material, the second glaze material penetrates the first glaze material layer so that the first glass layer and the second glass layer are firmly connected to each other. and furthermore, the formation of cracks at their interface is avoided. According to this configuration, the entire firing step can be completed immediately and the production cost can be reduced.

Preferably, in the method of manufacturing an article having a glass layer according to the invention, the main body material is given a higher linear thermal expansion coefficient than the first glass layer.

PL 205 186 B1

Moreover, in a method for producing an article having a glass layer according to the invention, it is preferable that a greater amount of potassium and a lesser amount of sodium are added to the second glass layer than to the first glass layer. Since potassium has a larger ion radius than sodium, sodium ions in the second enamel material are replaced with potassium ions in the first enamel material when the first and second enamel materials are used. Thereby it is possible to obtain an article having a glass layer according to the invention which has a second glass layer containing a higher amount of potassium and a lower amount of sodium than the first glass layer.

In the method of producing an article having a glass layer according to the invention, the second glaze material may contain an anti-bacterial metal. According to this configuration, an article can be made having a glass layer that has been rendered antimicrobial.

In the method of producing an article having a glass layer, according to the invention, fine zirconium particles with an average value of not less than 0.8 μm are added to the second material.

In the method for producing an article having a glass layer according to the invention, fine zirconium particles are added to the second material in an amount of 0.5 to 2 wt.%.

Brief description of the drawings

Fig. 1 is a sectional view of the base material and first glaze material layer of Examples 1-7 relating to the invention.

Fig. 2 is a sectional view of the base material and layer of the first glaze material and the layer of the second glaze material of Examples 1-7 relating to the invention.

Fig. 3 is a sectional view of the main body of the ceramic product, the first glass layer and the second glass layer of Examples 1-7 relating to the invention.

Fig. 4 is a sectional view of a sample of Examples 1-7 relating to the invention.

Fig. 5 is a top view of a sample of Examples 1-7 relating to the invention.

Fig. 6 is a sectional view of a sample of comparative examples 1 and 2 relating to the invention.

Fig. 7 is a sectional view of a sample of comparative examples 3 and 4 relating to the invention.

Fig. 8 is the result of an EPMA potassium surface analysis of a cross section of the sample of Examples 1-7 relating to the invention.

The best mode for carrying out the invention

Examples 1-7 of the practice of the invention and comparative examples 1-4 will be described below.

(Example 1) "Preparation Stage"

As shown in Figures 1 and 2, the basic material for the tiles 1 is prepared from the following composition cut into squares with a side of 50 ± 2 mm (thickness at least 10 mm).

(Mixing ratio of the basic material (wt%))

Field spar 28.2

Silica sand 11.8

Sericite 15.0

Clay 45.0

A first enamel material and a second enamel material with the following compositions are prepared.

(Mixing ratio of the first glaze material (wt%))

Field spar 42,456

Frit

Calcium

Dolomite

Zinc white

The Gairome Clay

Aluminum oxide

Silica sand

Opaque agent Fire-clay refractory Pigment

The frit has the following composition (wt%).

SiO₂

Al2^ABOUT3

CaO

Na2O

1,617

11,827

5,054

1,516

4,043

1,769

9,603

6,368

15,163

0,581

49,3

11,1

0,2

19,1

PL 205 186 B1

K2O 1.0

B2O3 19.2

The first glaze material contains 2 wt.%. K2O.

(Mixing ratio of the second glaze material (wt%))

Silica sand 31.0

Lime 6.0

Clay 13.0

Antimicrobial agent 50.0

The antimicrobial agent has the following composition (wt%).

Ag2O 25.88

P2O5 4.98

CaO 0.01

SiO2 56.84

Al2O3 9.36

Fe2O3 0.10

K2O 0.43

On₂About 0.06

SrO 0.01

Loss on ignition 2.34

In the above composition, 1 wt.% Is used as the fine hard particles to form the second glaze material. in the external settlement of fine zirconium particles 3a with an average particle diameter of 0.81 μm. The second glaze material contains 2 wt.%. On₂ABOUT.

"Glazing stage"

As shown in Fig. 1, the first glaze material is applied to the surface of the base material 1 to form layer 2 of the first glaze material, and then, as shown in Fig. 2, the second glaze material is applied to the surface of the layer 2 of the first glaze material to form the first glaze material. layer 3 of the second glaze material.

"Firing stage"

The base material 1 with the layer 2 of the first glaze material and the layer 3 of the second glaze material is fired at a temperature of 1210 ° C. In this procedure, the base material 1 is sintered and the layer 2 of the first glaze material and the layer 3 of the second glaze material are melted to form a first glass layer 4 and a second glass layer 5 on the main body 1 of the ceramic product as shown in Fig. 3. Fine zirconium particles 3a are dispersed on the surface of the second glass layer 5.

The second glass layer 5 here has a lower linear thermal expansion coefficient than the first glass layer 4, and the difference between them is 3 x 10^-7/ ° C. Moreover, the first glass layer 4 has a lower linear thermal expansion coefficient than the main body 1 of the ceramic product, and the difference therebetween is 4 x 10^-7/ ° C. Moreover, the first glass layer 4 and the second glass layer 5 have a thickness difference of 20/1. The second glass layer 5 has a silver compound 6 as antimicrobial metal dispersed therein.

"Water repellant treatment stage"

Thereafter, a water repellant treatment step is carried out on the surface of the second glass layer.

The first factor that is created from is prepared

C8F17CH2Si (OCH3) 3 as an organic silicon compound containing a perfluoroalkyl group and with Si (CH3) 3CH2CH2- (Si (CH3) 2O) 10-Si (CH3) 2CH2CH2Si (OCH3) 3 as a polymethylsiloxane compound containing a hydrolysable group, which are co-hydrolyzed in a hydrophilic solvent containing 0.1N aqueous hydrochloric acid, t-butanol and hexane. They are contemplated to contain correspondingly silanol (Si-OH) groups.

A mixture of polyorganosiloxane (HO- (Si (CH3) 2O) 30-Si (CH3) 2OH) and methanesulfonic acid as strong acid is prepared as the second agent.

ml of the second agent is added with stirring to 5 ml of the first agent to form a water repellant treatment liquid. A water repellant treatment liquid is applied to the surface of a ceramic main body 1 having a first glass layer 4 and a second glass layer 5, and then dried for about 10 minutes. The surface is then washed with ethanol and dried.

PL 205 186 B1

Through the above procedures as shown in Fig. 4 and obtaining a sample that comprises a base body 1, a first glass layer 4 comprising a first glaze material formed on the base body 1, a second glass layer 5 comprising a second glaze material that differs from the first glaze material and comprises an antimicrobial metal and is formed on the outer surface of the first glass layer 4 as well as the water repellent layer 7, comprising a water-repellent component and formed on the outer surface of the second glass layer 5, and further comprising fine zirconium particles 3a on the second glass layer and on the surface of the water repellent layer 7.

(Example 2)

In the preparation of example 1, 2 wt. in the external settlement of the fine particles 3a, the zirconium in example 1 is contained in the second glaze material. The other conditions are the same as in example 1.

(Example 3)

In the preparation of example 1, 1 wt.%. in the external settlement of the fine zirconium particles 3a with an average particle diameter of 1.55 μm is contained in the second glaze material as fine hard particles. The other conditions are the same as in example 1.

(Example 4)

1.2 wt.% In the preparation of the example. in the external settlement of the fine particles 3a, the zirconium in example 3 is contained in the second glaze material. The other conditions are the same as in example 1.

(Example 5)

In the preparation of example 1, 1 wt.%. in the external settlement of the fine zirconium particles 3a with an average particle diameter of 20 μm is contained as fine hard particles in the second enamel material. The other conditions are the same as in example 1.

(Example 6)

1.2 wt.% In the preparation of the example. in the external settlement of the fine zirconium particles 3a in example 5 is contained in the second glaze material. The other conditions are the same as in example 1.

(Example 7)

1.4 wt.% In the example preparation stage. in the external settlement of the fine zirconium particles 3a in example 5 is contained in the second glaze material. The other conditions are the same as in example 1.

(Comparative example 1)

As shown in Fig. 6, a glaze material of the following composition is applied to a base material 1 of the same type as in Example 1 to form a glaze material layer.

<td colspan="2">(Glaze material mixing ratio (wt%))</td>

<td>Field spar</td><td> 10,0</td>

<td>Kaolin</td><td> 5,0</td>

<td>Frit</td><td> 85,0</td>

<td>The frit has the following composition (wt.%)</td><td></td>

<td>SiO₂</td><td> 67,4</td>

<td>^Al2^ABOUT3</td><td> 8,6</td>

<td>MgO</td><td> 2,7</td>

<td>CaO</td><td> 5,7</td>

<td>SrO</td><td> 3,2</td>

<td>Na2O</td><td> 2,3</td>

<td>K2O</td><td> 3,2</td>

<td>^B2^ABOUT3</td><td> 3,5</td>

<td>ZnO</td><td> 2,3</td>

<td>MoO3</td><td> 1,1</td>

<td colspan="2">The base material 1 with the glaze material layer is fired at 1210 ° C</td>

In accordance with these procedures, the glaze material layer is melted to form a glass layer 8 on the main body 1 of the ceramic product. A sample is obtained which comprises a main body 1 of a ceramic product and a glass layer 8 containing glaze material formed on the base body 1.

PL 205 186 B1 (Comparative example 2)

The glaze material of the following composition is applied to the base material 1 of the same type as in Example 1 to form the glaze material layer. The base material 1 with the glaze material layer is fired at 1210 ° C to obtain a sample similar to that of Comparative Example 1 shown in Fig. 6.

<td colspan="2">(Glaze material mixing ratio (wt%))</td>

<td>Field spar Frit Calcium Dolomite Zinc white The Gairome Clay Aluminum oxide Silica sand Opacity factor. Fireproof chamotte material Pigment The frit here is the same as in example 1.</td><td>4.456 1.617 11.827 5.054 1.516 4.043 1.769 9,603 6.368 15,163 0.581 To form the enamel material, in the above com-</td>

position is included in the external settlement 6.3% wt. fine zirconium particles with an average diameter of 1.55 μm.

(Comparative example 3)

The same base material 1 as in Example 1 is prepared, a first glaze material comprising the glaze material of Comparative Example 1 and a second glaze material having the following composition. The base material 1 with the layer of the first glaze material and the layer of the second glaze material is fired at 1210 ° C to obtain a sample. According to these procedures, as shown in Fig. 7 the main body 1 of the ceramic product is produced, a first glass layer 9 comprising a first glaze material formed on the main body 1 of the ceramic product and a second glass layer 10 comprising a second glaze material formed on the glass layer 9.

(Mixing ratio of the second glaze material (wt%))

Silica sand 31.0

Lime 2.3

Clay 12.4

Zinc white 3.9

Frit 0.5

Antimicrobial agent 50.0

The frit is the same as Comparative Example 1, and the Antimicrobial Agent is the same as Example 1.

(Comparative example 4)

The same base material 1 as in Example 1 is prepared, a first glaze material comprising the glaze material of Comparative Example 2 and a second glaze material having the composition given below. The base material 1 with the first glaze material layer and the second glaze material layer is fired at 1210 ° C to obtain a sample that is similar to the sample of Comparative Example 3 shown in Fig. 7.

(Mixing ratio of the second glaze material (wt%))

Silica sand 33.0

Lime 8.5

Aluminum oxide 7.0

Antibacterial factor 51.2

The antimicrobial agent is the same as in example 1.

(Rating)

The samples of Examples 1-7 and Comparative Examples 1-4 were compared and the presence of microscopic pinholes on the surface was confirmed using a digital microscope to assess the smoothness. These are shown in Table 3. In Table 3, samples with excellent smoothness are labeled A, and samples that are not smooth are labeled B.

PL 205 186 B1

Table 3

<td colspan="2" rowspan="2">A sample</td><td rowspan="2">Smoothness</td><td colspan="3">Number of blemishes</td><td rowspan="2">Total blemish length (mm)</td>

<td>0.7 (mm) or more</td><td>0.3-0.6 (mm)</td><td>0-0.2 (mm)</td>

<td rowspan="7">Example</td><td> 1</td><td>AND</td><td> 1</td><td> 1</td><td> 2</td><td> 1,7</td>

<td> 2</td><td>AND</td><td> 0</td><td> 0</td><td> 0</td><td> 0,0</td>

<td> 3</td><td>AND</td><td> 0</td><td> 1</td><td> 2</td><td> 0,6</td>

<td> 4</td><td>AND</td><td> 1</td><td> 1</td><td> 4</td><td> 1,8</td>

<td> 5</td><td>AND</td><td> 2</td><td> 2</td><td> 0</td><td> 3,0</td>

<td> 6</td><td>AND</td><td> 0</td><td> 1</td><td> 1</td><td> 0,7</td>

<td> 7</td><td>AND</td><td> 0</td><td> 0</td><td> 0</td><td> 0,0</td>

<td rowspan="4">Example comparative</td><td> 1</td><td>B</td><td> 9</td><td> 10</td><td> 8</td><td> 13,7</td>

<td> 2</td><td>B</td><td> 0</td><td> 1</td><td> 1</td><td> 0,6</td>

<td> 3</td><td>AND</td><td> 6</td><td> 5</td><td> 17</td><td> 10,3</td>

<td> 4</td><td>AND</td><td> 1</td><td> 4</td><td> 2</td><td> 2,8</td>

Table 3 shows that the samples of Examples 1-7 and comparative Examples 3 and 4 have essentially no microscopic pinholes on the surface and exhibit excellent smoothness. On the other hand, the samples of comparative Examples 1 and 2 have microscopic holes on the surface, even if only a small number, and have a rather inferior smoothness. This is because the glass layers of the samples of Examples 1-7 and comparative examples 3 and 4 have a first glass layer and a second glass layer, and even if microscopic holes are formed up to the first glass layer due to the action of the base material 1 it is difficult to stretch the influence of the base material 1 on the second glass layer and it is difficult to find microscopic holes on the surface of the second glass layer. It is therefore understood that the samples of Examples 1-7 and Comparative Examples 3 and 4 are smoother and show excellent stain resistance.

In the samples of Examples 1 and 7, the fine particles of zirconium 3a are present in an amount that does not affect the color of the second glass layer 5 and are dispersed such that the surface smoothness of the second glass layer 5 is not affected, giving it an excellent look.

Moreover, since the samples of Examples 1-7 have a water repellent layer 7 on the surface side of the second glass layer 5, even though water containing high levels of stain-causing components is applied to the surface of the second glass layer 5 having a low number of blemishes, it is difficult to remain on the surface of the second glass layer 5. stains due to the water-repellent effect, which provides excellent protection against stains. Moreover, in the samples of Examples 1-7, since the silver compound 6 as antimicrobial metal is contained in the second glass layer 5, it has an antimicrobial effect and also provides excellent stain protection.

The samples of Examples 1-7 and comparative Examples 1-4 were subjected to the following brushing test.

(Brushing test)

A commercial toothbrush was prepared with a commercially available abrasive applied and the surface of the sample was scrubbed with the toothbrush 20 times under constant pressure. According to this procedure, the number of blemishes and the total blemish length (mm) were determined to be 4 cm². The results are also presented in Table 3.

Table 3 shows that the samples of Examples 1-7 and comparative Examples 2 and 4 inhibit scorch. This is because the linear thermal expansion coefficient of the second glass layer is less than the linear thermal expansion coefficient of the first glass layer in Examples 1-7 and Comparative Examples 4, whereby the second glass layer is pressed by receiving a compressive stress. caused by the shrinkage of the first glass layer to increase the surface hardness. In particular, in the samples of Examples 1-7, no major blemishes arise because of abrasive wear

This effect is prevented by the fine zirconium particles 3a situated on the water repellent layer 7. It follows that the specimens of Examples 1-7 have a hard time attaching stains to blemishes and cracks, thereby achieving excellent stain resistance.

Furthermore, it is understood that as shown in Fig. 8 the X-ray resistance of the potassium line Ka in the samples of Examples 1-7 is in the lower range from 198 to 331 cps in the first glass layer 4 but is in the upper range from 331 to 463 cps in the second. layer 5 of glass. Therefore, in the case of the samples of Examples 1-7, it can be said that the sodium ions having a small ion radius contained in the second glass layer 5 are replaced by potassium ions having a large ion radius contained in the first glass layer 4 and the potassium ions diffuse into the second layer 5 glasses. The second glass layer 5 itself creates a compressive stress and is strengthened.

(Antimicrobial test)

Three pieces of each of the samples of Examples 1-7 and Comparative Examples 1-4 were prepared and subjected to an anti-microbial thin film test. The average differences in the differentiation rate of Esherichia coli (IFO3972) at the appropriate medium concentration are shown in Table 4. The average differences in the differentiation rate of Staphylococcus aureus (IFO12732) at the respective medium concentrations are shown in Table 5. In Tables 4 and 5, no antibacterial effect was observed with an average difference in differentiation rate of less than 2.0.

Table 4

<td>Medium concentration</td><td colspan="7">Example</td><td colspan="4">Comparative example</td>

<td></td><td> 1</td><td> 2</td><td> 3</td><td> 4</td><td> 5</td><td> 6</td><td> 7</td><td> 1</td><td> 2</td><td> 3</td><td> 4</td>

<td>1/500 NB</td><td> 5,5</td><td> 5,5</td><td> 5,5</td><td> 5,5</td><td> 5,5</td><td> 5,5</td><td> 5,5</td><td> 2,4</td><td> 2,4</td><td> 5,5</td><td> 5,5</td>

<td>1/200 NB</td><td> 4,2</td><td> 4,2</td><td> 4,2</td><td> 4,2</td><td> 4,2</td><td> 4,2</td><td> 4,2</td><td> 1,2</td><td> 1,2</td><td> 4,2</td><td> 4,2</td>

<td>1/50 NB</td><td> 2,7</td><td> 2,7</td><td> 2,7</td><td> 2,7</td><td> 2,7</td><td> 2,7</td><td> 2,7</td><td> 0,0</td><td> 0,0</td><td> 2,7</td><td> 2,7</td>

Table 5

<td>Medium concentration</td><td colspan="7">Example</td><td colspan="4">Comparative example</td>

<td></td><td> 1</td><td> 2</td><td> 3</td><td> 4</td><td> 5</td><td> 6</td><td> 7</td><td> 1</td><td> 2</td><td> 3</td><td> 4</td>

<td>1/500 NB</td><td> 4,8</td><td> 4,8</td><td> 4,8</td><td> 4,8</td><td> 4,8</td><td> 4,8</td><td> 4,8</td><td> 2,2</td><td> 2,2</td><td> 4,8</td><td> 4,8</td>

<td>1/200 NB</td><td> 3,7</td><td> 3,7</td><td> 3,7</td><td> 3,7</td><td> 3,7</td><td> 3,7</td><td> 3,7</td><td> 0,0</td><td> 0,0</td><td> 3,7</td><td> 3,7</td>

<td>1/50 NB</td><td> 2,3</td><td> 2,3</td><td> 2,3</td><td> 2,3</td><td> 2,3</td><td> 2,3</td><td> 2,3</td><td> 0,0</td><td> 0,0</td><td> 2,3</td><td> 2,3</td>

Table 4 and Table 5 show that with regard to the antimicrobial activity against both types of bacteria, the average difference in the rate of change of at least 2.0 is maintained even when the concentration of the medium is increased in the samples of Examples 1-7, while the average difference is rates of change of at least 2.0 is maintained for only 1/500 of NB or less in the samples of Comparative Examples 1 and 2. Therefore, it is understood that the samples of Examples 1-7 have excellent stain resistance compared to the samples of comparative Examples 1 and 2. It is also understood that since the silver compound 6 as antimicrobial metal is only contained in the second glass layer 5 of the glass layers in the samples of Examples 1-7, the concentration of silver compound 6 on the surface side may be increased even if a smaller amount of the antimicrobial agent is used. than a conventional amount, imparting a greater antimicrobial effect can be achieved. Moreover, it is understood that in the samples of Examples 1-7, unnecessary consumption of the antimicrobial agent could be avoided.

It is understood that the samples of Examples 1-7 erase differences in average rate of change to a similar level as the samples of comparative Examples 3 and 4. It is therefore understood that as shown in Fig. 4, the samples of Examples 1-7 may have stain resistance. which is equivalent to the samples of comparative examples 3 and 4, even though they have fine zirconium particles 3a disposed on the second glass layer 5 to the surface of the water repellent layer 7.

Therefore, the samples of Examples 1-7 have an excellent surface smoothness and hardly blemishes on the surface, and an excellent stain resistance is reliably obtained.

PL 205 186 B1

The examples and comparative examples are given above by way of example only, and the invention can be carried out in embodiments which are varied and varied without departing from the spirit of the invention.

Industrial use

According to the stain resistance treatment method according to the invention, an article having a glass layer can be produced at a low cost, which can have an excellent antimicrobial effect.

In a product having a glass layer according to the invention, it is difficult for the surface to blemish and therefore excellent stain resistance is provided.