JP2021091581A - Metal-decorated ceramics and method of producing the same - Google Patents

Abstract

To provide a metal-decorated ceramic ware that can maintain the aesthetic appearance and is less likely to cause peeling of the metallic luster layer applied to the surface and loss of metallic luster even after repeated washing, and a method for producing the same.SOLUTION: A metal-decorated ceramic ware 1 having a metallic luster layer 3 formed on the surface of ceramic 4 and a glass layer 2 formed to cover the metallic luster layer 3. The yield point of the glass layer 2 is 550-580°C. The metal-decorated ceramic ware 1 is produced by laminating a metal paste for forming the metallic luster layer 3 and a glass paste for forming the glass layer 2 on the surface of the ceramic 4, followed by a firing treatment. The glass paste contains a glass powder having a yield point of 550 to 580°C.SELECTED DRAWING: Figure 1

Description

The present invention relates to metal decorative earthenware and a method for producing the same.

Some earthenware is decorated with a layer of precious metal to improve its design. Patent Document 1 discloses a method for producing earthenware having a metallic luster layer using a composition containing a powder of a noble metal.

Japanese Unexamined Patent Publication No. 2000-327462

However, when the precious metal decorative earthenware described in Patent Document 1 is used as tableware, for example, by repeating washing with an alkaline detergent or the like by using a dishwasher, the metallic luster layer applied to the surface thereof can be peeled off. There is a risk of loss of metallic luster.

The present invention has been made in view of the above problems, and a metal decorative earthenware capable of maintaining its aesthetic appearance without causing peeling of the metallic luster layer applied to the surface and loss of metallic luster even after repeated cleaning. It is intended to provide a manufacturing method.

One aspect of the present invention is a metallic luster layer formed on the surface of earthenware.
It has a glass layer formed so as to cover the metallic luster layer.
The yield point of the glass layer is in metal decorative earthenware at 550 to 580 ° C.

Another aspect of the present invention is a method for producing metal decorative earthenware having a metallic luster layer on its surface.
A metal paste for forming a metallic luster layer and a glass paste for forming a glass layer are laminated on the surface of earthenware, and then fired.
The glass paste is in a method for producing metal decorative earthenware, which contains glass powder having a yield point of 550 to 580 ° C.

The metal decorative earthenware has a metallic luster layer and a glass layer formed on the surface of the earthenware so as to cover the metallic luster layer. The glass layer is made of glass having a yield point of 550 to 580 ° C. By positively adopting glass having a yield point in this temperature range, the glass layer becomes a sound film without defects by suppressing the occurrence of cracks during manufacturing. Therefore, the metal decorative earthenware has a laminated structure in which a metallic luster layer is covered with a sound glass layer. Therefore, even if the cleaning is repeated, it is possible to prevent the metallic luster layer from being exposed due to peeling of the glass layer, etc., and it is possible to maintain the structure in which the metallic luster layer is covered with the glass layer for a long time. , The peeling of the metallic luster layer and the disappearance of the metallic luster are unlikely to occur, and the aesthetic appearance can be maintained.

In the above-mentioned production method, as the glass paste for forming the glass layer by firing, one containing glass powder having a yield point of 550 to 580 ° C. is used. As a result, cracks and the like are less likely to occur during cooling after firing, and as described above, a sound glass layer without defects can be formed. Therefore, it is possible to easily manufacture metal decorative earthenware that can maintain the excellent aesthetic appearance for a long period of time.

FIG. 5 is a cross-sectional view of the metal decorative earthenware according to the first embodiment. FIG. 5 is a cross-sectional view of the transfer paper according to the first embodiment. FIG. 2 is a cross-sectional view of the metal decorative earthenware according to the second embodiment. FIG. 2 is a cross-sectional view of the transfer paper according to the second embodiment.

On the glass layer, a second glass layer that covers a part or all of the surface of the glass layer can be further provided. In this case, the presence of the second glass layer can further enhance the durability of the glass layer and maintain the aesthetic appearance of the metal decorative earthenware for a longer period of time.

Further, the yield point of the second glass layer in this case is preferably 550 to 580 ° C. By making the yield point of the second glass layer the same as that of the glass layer, simultaneous firing of both can be facilitated, and the process at the time of manufacturing can be rationalized.

The second glass layer may contain an oxide pigment. In this case, it is possible to obtain a matting effect, a coloring effect, and the like by the oxide pigment, and it is possible to adjust the appearance characteristics to have different tastes instead of the appearance characteristics by only the metallic luster layer. Examples of the oxide pigment include a cobalt-based oxide that can be colored blue, a chromium-based oxide that can be colored green, and a manganese-based oxide that can be colored purple.

As a method for producing the metal decorative earthenware, a ceramic is prepared, a metal paste that forms a metallic gloss layer by firing is applied to the surface of the ceramic and fired, and then a glass paste that forms a glass layer by firing is applied. There is a method of performing a plurality of firing treatments, that is, laminating and firing treatments.

It is also possible to adopt a method in which the metal paste and the glass paste are fired at the same time as described below.
A method for producing metal decorative earthenware having a metallic luster layer on its surface.
A metal paste for forming a metallic luster layer and a glass paste for forming a glass layer are laminated on the surface of earthenware, and then fired.
The glass paste contains a glass powder having a yield point of 550 to 580 ° C., and there is a method for producing metal decorative earthenware. According to this method, the metallic luster layer and the glass layer can be formed by a single firing treatment, which is very advantageous in the manufacturing process.

In the method for producing metal decorative earthenware, a glass paste containing a glass powder having a yield point of 550 to 580 ° C. is used as the glass paste for forming a glass layer by firing. As a result, cracks and the like are less likely to occur during cooling after firing, and as described above, a sound glass layer without defects can be formed. Therefore, it is possible to easily manufacture metal decorative earthenware that can maintain the excellent aesthetic appearance for a long period of time. In order to ensure such an effect, the yield point is more preferably 555 ° C. or higher and 570 ° C. or lower.

The firing process can be performed under the condition that the ceramic is heated to a temperature of 750 to 850 ° C. By keeping the temperature of the firing treatment within this temperature range, the above-mentioned excellent quality glass layer can be formed more reliably. Further, by setting the temperature of the firing treatment within the above temperature range, the formation of the metallic luster layer and the formation of the glass layer can be surely performed at the same time in one firing treatment, and the manufacturing process can be rationalized.

As the glass paste, a glass paste containing 30% by weight or more of glass powder as a solid content and containing squeegee oil or the like in addition to the solid content can be used. As the glass powder, those having various compositions can be adopted as long as the yield point is in the range of 550 to 580 ° C., and examples thereof include those shown in the embodiments described later. Any glass powder can be produced by pulverizing glass having a desired composition.

The glass paste may contain 0.1 to 3.0% by weight of _{titanium oxide (TiO 2) powder as a solid content.} In this case, the effect of suppressing the occurrence of cracks in the glass layer can be further enhanced while maintaining the gloss of the glass layer.

It is also possible to further laminate a second glass paste for forming the second glass layer on the surface of the glass paste, and then perform the firing treatment. As the second glass paste that forms the second glass layer by firing, it is preferable to use a paste containing glass powder having a yield point of 550 to 580 ° C. In this case, it is possible to reliably suppress the occurrence of cracks in the second glass layer during manufacturing.

In addition, the second glass paste can contain the above-mentioned various oxide pigments, and can be adjusted to have different appearance characteristics.

(Embodiment 1)
An embodiment of a metal decorative earthenware and a method for manufacturing the same will be described with reference to FIGS. 1 and 2.
As shown in FIG. 1, the metal decorative earthenware 1 of the present embodiment has a metallic luster layer 3 formed on the surface of the earthenware 4 and a glass layer 2 formed so as to cover the metallic luster layer 3. The yield point of the glass layer 2 is 550 to 580 ° C.

In the present embodiment, the ceramic 4 as the base material decorated with the metallic luster layer 3 is glazed and fired by a general method. In this embodiment, the ceramic 4 is bone china.

The metal decorative earthenware 1 is decorated by applying a pattern to a part of the surface of the earthenware 4 by a metallic luster layer 3 (not shown). The metallic luster layer 3 contains one or more selected noble metals from gold, platinum, and palladium as main components.

Further, the glass layer 2 is formed so as to cover the entire metallic luster layer 3. The glass layer 2 is transparent and is made of inorganic glass that easily transmits visible light.

Next, the method for manufacturing the metal decorative earthenware 1 described above will be described.
In this embodiment, a metal paste 31 for forming a metallic luster layer 3 and a glass for forming a glass layer 2 are formed on the surface of a ceramic material 4 as a base material by a screen printing method using a transfer paper 5. The paste 22 was laminated. Then, a firing process was carried out to manufacture the metal decorative earthenware 1.

As shown in FIG. 2, the transfer paper 5 used for screen printing has a glue layer 52 containing a water-soluble glue formed on the surface of the mount 51. The glue layer 52 contains, for example, starch or dextrin.

In this embodiment, a pattern formed by the metal paste 31 is laminated on the upper surface of the glue layer 52 by screen printing. The metal paste 31 contains one or more selected noble metals as a main component from gold, platinum, and palladium. Further, the metal paste 31 can contain the noble metal as an organometallic compound, not as a powder. The metal paste 31 is, for example, a commercially available gold liquid, and forms a metallic luster layer 3 having a golden color or the like by a firing treatment.

Further, the glass paste 22 is laminated on the upper surface of the metal paste 31 by screen printing. The composition of the glass powder contained in the glass paste 22 is not particularly limited as long as the yield point is in the range of 550 to 580 ° C., but is composed of, for example, the following composition. Glass powder contained in the glass paste 22, as a main component, a SiO ₂ 50-70 _wt%, the B 2 _{O 3} 10 to 20 wt%, the _Al 2 _{O 3} 5 to 15 wt%, _Na 2 O, K ₂ O, containing an alkali metal oxide such as LiO ₂ 0.1 to 20 wt%. Further, as other components, alkaline earth metal oxide, zirconium oxide, zinc oxide and the like may be contained. The yield point of the glass powder is preferably 555 to 570 ° C.

The yield point of the glass constituting the glass powder was measured using a thermomechanical analyzer (Thermo plus EVO2 TMA-8311, manufactured by Rigaku Co., Ltd.). The yield point indicates the temperature at which the expansion of the glass apparently stops in the thermal expansion curve of the glass constituting the glass powder, and is one of the indexes indicating the softness of the glass.

The glass paste 22 mainly contains glass powder as a solid content, but in addition, titanium oxide powder can be further contained in an amount of 0.1 to 3.0% by weight. The content of the titanium oxide powder is more preferably 0.5 to 2.0% by weight. The particle size of the titanium oxide powder can be 0.5 μm or less. It should be noted that the titanium oxide powder does not need to be added indispensably, and in the evaluation test described later, tests were conducted and evaluated in both the case where the titanium oxide powder was not added and the case where the titanium oxide powder was added. Further, the glass paste 22 contains squeegee oil other than the solid content.

Further, in the transfer paper 5, a protective layer 53 for fixing the position of each layer is laminated by screen printing so as to cover the laminated metal paste 31 and glass paste 22. The protective layer 53 is made of, for example, an acrylic resin.

Next, the transfer paper 5 in which the layers produced by the above method are laminated is immersed in water to dissolve the glue layer 52, whereby a composition composed of the metal paste 31 and the glass paste 22 covered with the protective layer 53 is formed from the mount 51. Remove. Next, the constituents removed from the mount 51 are laminated on the surface of the ceramics 4 which is the base material for decoration, and the ceramics 4 and the constituents are brought into close contact with each other for transfer. At the time of transfer, for example, a rubber spatula or the like is used to bring the composition into close contact with the surface of the ceramics 4.

Next, by firing the ceramic 4 in which the metal paste 31 and the glass paste 22 are laminated, the metal decorative ceramic 1 having the metal gloss layer 3 and the glass layer 2 can be obtained. The firing treatment is performed under the condition that the ceramic 4 is heated to a temperature of 750 to 850 ° C. The protective layer 53 burns and disappears during firing.

As shown in FIG. 1, the glass layer 2 after the firing treatment is formed by melting the glass powder by the firing treatment so as to smoothly spread so as to cover the entire upper surface and the outer peripheral edge of the metallic luster layer 3. The metallic luster layer 3 is entirely covered with the laminated glass layers 2.

(Evaluation test 1)
In the configuration of the first embodiment described above, a plurality of metal decorative earthenware (Examples 1 to 4, Comparative Examples 1 and 2) having different yield points of the glass layer 2 (or the glass powder in the glass paste 22) are produced, and the appearance is observed. Was evaluated by. The composition and yield point of the glass powder in the glass pastes 22 of Examples 1 to 4 and Comparative Examples 1 and 2 are shown in Table 1. The production method of each Example and Comparative Example was substantially the same as that of the first embodiment described above, and the firing treatment was performed under the condition of heating the ceramics 4 to a temperature of 800 ° C. Further, in the metal decorative earthenware of each Example and Comparative Example used in the evaluation test 1, the glass paste 22 was configured so that titanium oxide powder was not added. Further, the glass paste 22 was prepared by mixing glass powder and squeegee oil in a weight ratio of 1: 1.

The evaluation items for appearance observation were two items: the presence or absence of cracks in the glass layer 2 and the glossy state of the glass layer 2 and the metallic luster layer 3. The presence or absence of cracks and the state of gloss were visually evaluated and evaluated according to the following evaluation criteria. Regarding the presence or absence of cracks, a plurality of metal decorative earthenware was manufactured in each of Examples 1 to 4 and Comparative Examples 1 and 2, and the proportion of the metal decorative earthenware in which cracks were generated was evaluated among the manufactured plurality of metal decorative earthenware. did. Further, the glossy state of the glass layer 2 and the metallic luster layer 3 was evaluated integrally with the glass layer 2 and the metallic luster layer 3. The results are shown in Table 2.
[Presence / absence of cracks]
⊚: No cracks were found in all of the manufactured metallic decorative earthenware ○: Among the manufactured metallic decorative earthenware, only a few cracks were confirmed ×: Of the manufactured metallic decorative earthenware Cracks were confirmed in more than 10% [Glossy state of glass layer and metallic luster layer]
◎: Strong gloss 〇: Glossy ×: Almost no gloss

As shown in Table 2, in the case of Comparative Example 1 produced using glass powder having a yield point of less than 550 ° C., it was confirmed that cracks were generated in the glass layer 2 in most of the produced plurality of metal decorative earthenware. It is considered that cracks were generated during cooling due to the excessive dissolution of the glass powder and the large difference in the coefficient of linear expansion between the glass layer 2 and the metallic luster layer 3.

Further, in the case of Comparative Example 2 produced using glass powder having a yield point higher than 580 ° C., no crack was observed in the glass layer 2 in all the metal decorative earthenware, but the glass layer 2 and the metallic luster were not observed. The gloss of the layer 3 was weak, which was aesthetically unpleasant. If the yield point of the glass powder is higher than 580 ° C., it is considered that the cause is that the glass powder was not sufficiently melted by the firing treatment.

Further, in Example 1 produced using glass powder having a yield point of 553 ° C., although cracks were slightly confirmed, the occurrence rate was low and there was no major problem in industrial production. there were. On the other hand, in Examples 2 and 3 produced using glass powder having a yield point in the range of 555 to 570 ° C., the glass layer 2 and the metallic luster layer 3 had strong luster, resulting in more aesthetically pleasing results. .. When the yield point of the glass powder is 550 to 580 ° C. (particularly, when the yield point is 555 to 570 ° C.), the glass powder is sufficiently melted by the firing treatment, and the glass layer 2 is formed without excessive melting. Therefore, it is considered that the glass layer 2 has gloss and the occurrence of cracks is suppressed.

(Evaluation test 2)
In the configuration of the first embodiment described above, a plurality of metal decorative earthenware (Examples 2, 5, 6 and Comparative Examples 3 and 4) having different firing treatment temperatures were produced and evaluated by observing their appearance. Each of the examples and comparative examples other than Example 2 used in the evaluation test 2 had the same configuration as that of Example 2 used in the evaluation test 1 except for the temperature of the firing treatment. The metal decorative earthenware 1 of Example 2 evaluated in the evaluation test 2 has the same configuration as the metal decorative earthenware 1 of Example 2 evaluated in the evaluation test 1, including the temperature of the firing process. That is, in each of the Examples and Comparative Examples used in the evaluation test 2, the glass paste 22 used at the time of production was configured so that titanium oxide powder was not added. Similar to the evaluation test 1, the evaluation items for the appearance observation were two items, that is, the presence or absence of cracks in the glass layer 2 and the glossy state of the glass layer 2 and the metallic luster layer 3. The evaluation criteria were the same as in Evaluation Test 1. The results are shown in Table 3.

As shown in Table 3, in the case of Comparative Example 3 in which the firing treatment temperature was less than 750 ° C., the glass layer 2 and the metallic luster layer 3 had almost no luster, which was aesthetically unfavorable. It is considered that the glass powder was not sufficiently melted by the firing treatment, and the gloss of the formed glass layer 2 was weakened.

Further, in the case of Comparative Example 4 in which the firing temperature was higher than 850 ° C., it was confirmed that cracks were generated in the glass layer 2 in 10% or more of the metal decorative ceramics. The cause is considered to be the same as in the case of Comparative Example 1 in the evaluation test 1.

On the other hand, when the firing treatment temperature was 750 to 850 ° C. (Examples 2, 5 and 6), no crack was confirmed in the glass layer 2 in all the metal decorative ceramics 1. Further, the glass layer 2 and the metallic luster layer 3 were glossy, resulting in excellent aesthetics. When the firing treatment temperature is 750 to 850 ° C., the glass powder is sufficiently melted and the glass layer 2 is formed without being excessively melted, so that the glass layer 2 has gloss and the occurrence of cracks is suppressed. It is thought that it was.

(Evaluation test 3)
In the configuration of the first embodiment described above, a plurality of metal decorative earthenware (Examples 7 to 10 and Comparative Example 5) in which titanium oxide powder is contained in the glass paste 22 and the proportions thereof are different are prepared and evaluated by appearance observation. It was. In addition, the metal decorative ceramics 1 of Example 1 to which the titanium oxide powder used in the evaluation test 1 was not added was also evaluated. The metal decorative earthenware of Examples 7 to 10 and Comparative Example 5 had substantially the same constitution as that of Example 1 except for the titanium oxide powder. Similar to the evaluation test 1, the evaluation items were two items, that is, the presence or absence of cracks in the glass layer 2 and the glossy state of the glass layer 2 and the metallic luster layer 3, and the evaluation criteria for each were the same as in the evaluation test 1. The results are shown in Table 4.

As shown in Table 4, in Example 1 in which the titanium oxide powder was not added, as described in the evaluation test 1, cracks were slightly observed, whereas the titanium oxide powder was added to the glass paste 22. In Examples 7 to 10 and Comparative Example 5 in which the above was added, no cracks were observed in all the metal decorative ceramics. It is considered that the occurrence of cracks was suppressed by the crack extension suppressing effect of titanium oxide.

However, in the case of Comparative Example 5 in which the content of the titanium oxide powder exceeded 3.0% by weight, the glass layer 2 became matte, which was aesthetically unfavorable. On the other hand, in the case of Examples 7 to 10 in which the content of the titanium oxide powder was in the range of 0.1 to 3.0% by weight, the gloss of the glass layer 2 and the metallic luster layer 3 was strong. Since the particle size of the added titanium oxide powder is as small as 0.5 μm or less, it is considered that the reason is that the addition amount of 3.0% by weight or less has almost no effect on the gloss of the glass layer 2. Although the effect of suppressing crack growth can be expected by adding a metal oxide other than titanium oxide, the particle size tends to be larger than that of titanium oxide powder, and it is difficult to maintain the gloss of the glass layer 2.

(Evaluation test 4)
The metal decorative earthenware used in the evaluation test 1 (Example 2, Comparative Examples 1 and 2) was repeatedly washed with a dishwasher (JWE-400TUB3 manufactured by Hoshizaki Corporation), and after washing, evaluation was performed by observing the appearance. .. Further, as the metal decorative earthenware of Comparative Example 6, a metal decorative earthenware produced by the same manufacturing method as that of the metal decorative earthenware 1 of Example 2 except that the glass paste 22 is not laminated on the metal paste 31 is prepared and the same. Was evaluated. That is, the glass layer 2 is not formed on the metal decorative earthenware of Comparative Example 6, and the metallic luster layer 3 is exposed.
The conditions for washing with a dishwasher using washing water containing an alkaline detergent are shown below.
<Washing conditions (per wash)>
Cleaning temperature: 70 ° C
Cleaning time: 90 seconds Rinse temperature: 85 ° C
Rinse time: 7 seconds

The evaluation item for appearance observation is the degree of peeling of the metallic luster layer 3. The evaluation was performed visually, and the amount of decrease in the area of the metallic luster layer 3 after cleaning was confirmed based on the area of the metallic luster layer 3 before cleaning. The results are shown in Table 5.

As shown in Table 5, in the metal decorative earthenware of Comparative Example 6 in which the glass layer 2 was not formed, the metallic luster layer 3 was not peeled off after 300 washes, but the metallic luster layer 3 was not formed after 700 washes. Peeling was confirmed. It is considered that the metallic luster layer 3 was peeled off due to the influence of the washing water.

Further, in the metal decorative earthenware of Comparative Example 1, peeling of the metallic luster layer 3 was confirmed by washing 700 times. It is considered that the washing water invaded from the crack and caused the peeling of the metallic luster layer 3.

On the other hand, in the metal decorative earthenware of Example 2 and Comparative Example 2, peeling of the metallic luster layer 3 was not observed even after washing with the dishwasher 1100 times. Since the glass layer 2 is laminated so as to cover the metallic luster layer 3, it is considered that the contact between the metallic luster layer 3 and the washing water is suppressed, and as a result, the peeling of the metallic luster layer 3 can be suppressed.

(Embodiment 2)
As shown in FIG. 3, the metal decorative earthenware 1 of the present embodiment is a form in which the metal decorative earthenware 1 of the first embodiment further has a second glass layer 21.

In the metal decorative earthenware 1 of the present embodiment, a second glass layer 21 that covers a part or all of the surface of the glass layer 2 is further provided on the glass layer 2. The yield point of the second glass layer 21 is 550 to 580 ° C. Further, the second glass layer 21 contains an oxide pigment.

Next, the manufacturing method in the metal decorative earthenware 1 of this embodiment will be described.
In the present embodiment, as shown in FIG. 4, on the transfer paper 5, the metal paste 31 and the glass paste 22 are laminated on the surface of the glue layer 52 by screen printing, and the second glass is further formed on the surface of the glass paste 22. The paste 23 is laminated. Further, the protective layer 53 is laminated so as to cover the glass paste 22 and the second glass paste 23.

Then, by immersing the transfer paper 5 in which each layer is laminated in water to dissolve the glue layer 52, a composition composed of the metal paste 31, the glass paste 22, and the second glass paste 23 covered with the protective layer 53 from the mount 51. Remove. Next, the constituents removed from the mount 51 are laminated on the surface of the ceramics 4 which is the base material for decoration, and fired. That is, the metal decorative earthenware 1 is manufactured by further laminating the second glass paste 23 for forming the second glass layer 21 on the surface of the glass paste 22 and then performing a firing treatment.

The second glass paste 23 contains a glass powder having a yield point of 550 to 580 ° C. and an oxide pigment. The yield point of the glass powder is more preferably 555 to 570 ° C. Further, the second glass paste 23 may contain, for example, an oxide pigment for earthenware in the range of 0.1 to 50% by weight. When the oxide pigment is 0.1% by weight or less, the coloring is weak, and when it exceeds 50% by weight, the formed second glass layer 21 is difficult to adhere to the glass layer 2.

Further, the second glass paste 23 can contain 0.1 to 3.0% by weight of titanium oxide powder as a solid content, similarly to the glass paste 22. The content of the titanium oxide powder is more preferably 0.5 to 2.0% by weight. As in the case of the glass paste 22, the titanium oxide powder does not need to be added indispensably, and in the evaluation tests 5 and 6 described later, the metal decorative earthenware to which the titanium oxide powder was not added was tested and evaluated. .. Further, the second glass paste 23 contains squeegee oil other than the solid content, similarly to the glass paste 22.
Others are the same as in the first embodiment.
In addition, among the codes used in the second and subsequent embodiments, the same codes as those used in the above-described embodiments represent the same components and the like as those in the above-mentioned embodiments, unless otherwise specified.

(Evaluation test 5)
In the configuration of the second embodiment described above, the metal decorative porcelain having different yield points of the glass layer 2 (or the glass powder in the glass paste 22) and the second glass layer 21 (or the glass powder in the second glass paste 23) (Example 11). , Comparative Examples 7 and 8) were prepared, respectively, and evaluated by observing the appearance. The composition and yield point of the glass powder contained in the glass paste 22 and the second glass paste 23 of Example 11 are substantially the same as those of the glass powder contained in the glass paste 22 of Example 3 used in the evaluation test 1. is there. Further, the composition and yield point of the glass powder contained in the glass paste 22 of Comparative Example 7 and the second glass paste 23 are substantially the same as those of the glass powder contained in the glass paste 22 of Comparative Example 1 used in the evaluation test 1. It is the same. The composition and yield point of the glass powder contained in the glass paste 22 of Comparative Example 8 and the second glass paste 23 are substantially the same as those of the glass powder contained in the glass paste 22 of Comparative Example 2 used in the evaluation test 1. is there. Further, the second glass paste 23 of Examples 11 and Comparative Examples 7 and 8 contains 10% by weight of an oxide pigment. In both Example 11 and Comparative Examples 7 and 8, the firing treatment temperature was 800 ° C., and the titanium oxide powder was not added to the glass paste 22 and the second glass paste 23. Further, the glass paste 22 was prepared by mixing glass powder and squeegee oil in a weight ratio of 1: 1 in the same manner as in the evaluation test 1. The second glass paste 23 was prepared by mixing glass powder and squeegee oil in a weight ratio of 1: 1 and further adding an oxide pigment in a weight ratio of 10% by weight and mixing. The evaluation items for appearance observation are the presence or absence of cracks in the glass layer 2 and the second glass layer 21, and the glossy state of the glass layer 2, the second glass layer 21 and the metallic luster layer 3, and the results are shown in the table. Shown in 6. The evaluation criteria for the presence or absence of cracks and the state of gloss are the same as in the evaluation test 1.

As shown in Table 6, in the case of Comparative Example 7 produced using glass powder having a yield point of less than 550 ° C., cracks were generated in the glass layer 2 and the second glass layer 21 in most of the produced plurality of metal decorative earthenware. It was confirmed. It is considered that the cracks in the second glass layer 21 were generated due to the influence of the cracks in the glass layer 2.

Further, in the case of Comparative Example 8 produced using glass powder having a yield point higher than 580 ° C., in all the metal decorative ceramics, the glass layer 2 and the second glass layer 21 did not have cracks, but the glossiness was high. There were few, and the result was aesthetically unpleasant.

Further, in the case of Example 11 produced using glass powder having a yield point in the range of 550 to 580 ° C., no cracks were generated in the glass layer 2 and the second glass layer 21 in all the metal decorative ceramics 1. In addition, the result was glossy and excellent in aesthetics.

(Evaluation test 6)
Next, the metal decorative earthenware of Example 11 and Comparative Examples 7 and 8 used in the evaluation test 5 was repeatedly washed with a dishwasher in the same manner as in the evaluation test 4, and the degree of peeling of the metallic luster layer 3 was confirmed. did. The results are shown in Table 7 below. The evaluation criteria are the same as in the evaluation test 4.

As shown in Table 7, the metal decorative earthenware of Comparative Example 7 was washed with a dishwasher 700 times, and as a result, peeling of the metallic luster layer 3 was confirmed. It is considered that the washing water invaded from the crack and caused the peeling of the metallic luster layer 3.

On the other hand, in the metal decorative earthenware of Comparative Example 8 and Example 11, peeling of the metallic luster layer 3 was not observed even after washing was carried out 1100 times.

The present invention is not limited to each of the above embodiments, and can be applied to various embodiments without departing from the gist thereof.

For example, in the first and second embodiments, the glass layer 2 is formed on the entire upper surface and the outer peripheral edge of the pattern provided by the metallic luster layer 3. However, the glass layer 2 may be formed on the entire surface of the metal decorative earthenware 1, for example.

Further, for example, in the second embodiment, the glass paste 22 is laminated on the upper surface of the metal paste 31, the second glass paste 23 is further laminated on the upper surface of the glass paste 22, and the second glass is fired. It forms layer 21. However, the second glass layer 21 may be formed by laminating the glass paste 22 on the upper surface of the metal paste 31 and performing a firing treatment, and then laminating the second glass paste 23 and performing the firing treatment again.

Further, for example, in the second embodiment, the second glass layer 21 is formed on the glass layer 2. However, a third glass layer or a higher glass layer may be further laminated on the second glass layer 21.

Further, for example, in the metal decorative earthenware 1 of the second embodiment, the second glass layer 21 contains an oxide pigment. However, the glass layer 2 may contain an oxide pigment. Further, both the glass layer 2 and the second glass layer 21 may contain an oxide pigment.

Further, for example, in the metal decorative earthenware 1 of the second embodiment, the second glass layer 21 is colored by containing an oxide pigment. However, it may be colored as colored glass by a method other than containing an oxide pigment, such as dispersing a metal in the second glass layer 21.

1 Metal decorative earthenware 2 Glass layer 3 Metallic luster layer 4 Earthenware

Claims (7)

A metallic luster layer formed on the surface of earthenware,
It has a glass layer formed so as to cover the metallic luster layer.
The yield point of the glass layer is 550 to 580 ° C., which is a metal decorative earthenware. The metal decorative earthenware according to claim 1, further comprising a second glass layer covering a part or all of the surface of the glass layer on the glass layer. The metal decorative earthenware according to claim 2, wherein the yield point of the second glass layer is 550 to 580 ° C. A method for producing metal decorative earthenware having a metallic luster layer on its surface.
A metal paste for forming a metallic luster layer and a glass paste for forming a glass layer are laminated on the surface of earthenware, and then fired.
The glass paste is a method for producing metal decorative earthenware, which contains glass powder having a yield point of 550 to 580 ° C. The method for producing a metal decorative earthenware according to claim 4, wherein the firing treatment is performed under the condition that the earthenware is heated to a temperature of 750 to 850 ° C. The method for producing metal decorative earthenware according to claim 4 or 5, wherein the glass paste contains 0.1 to 3.0% by weight of titanium oxide powder as a solid content. The metal decoration according to any one of claims 4 to 6, wherein a second glass paste for forming a second glass layer is further laminated on the surface of the glass paste, and then the firing treatment is performed. How to make earthenware.

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