JP2014201477A - Low melting point leadless glass composition for ceramics - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a user-friendly leadless enamel color or leadless low fire scale glost having good seizure by firing at low temperature, maintaining transparency after firing, having no risk of causing peeling from an underlayer, and excellent in chemical durability.SOLUTION: A low melting point leadless glass composition is composed by containing: a powder type frit having a specific composition, high chemical durability, low glass transition temperature and a heat expansion coefficient of 7×10to 1×10; a glassy powder having amorphous particle plate shape, and having high chemical durability, a heat expansion coefficient of 1×10to 5×10, a same or similar refraction index as that of the frit and higher fire resistance than the frit, and blended with a ratio of 3 g to 30 g based on 100 g of the content of the frit; and a coloring component blended with a ratio of 1% to 30% based on the total weight.

Description

  The present invention is used for ceramics such as upper paints and glazes used for decorating ceramics, especially low paints that do not contain lead and have a low melting point, such as low-melting glazes such as glazed glazes and easy-fired glazes. The present invention relates to a low melting point lead-free glass composition.

  Traditional ceramics are generally ground and mixed raw materials such as ceramic stone, clay, feldspar, clay kneading, molding, drying, unglazed, painting with a high fire resistance colorant, application of base glaze (glazing), main firing (High temperature firing), painting with an upper paint, and refiring (low temperature firing). Of these steps, the main baking is performed by heating and baking at a high temperature of 1,200 ° C. to 1,350 ° C., and the re-baking is performed by baking at a relatively low temperature of 650 ° C. to 900 ° C. And about rebaking, heat baking is implemented by the temperature of about 650 degreeC-900 degreeC over multiple times according to the kind of upper paint to be used. In addition, the kaki-yaki is baked at a temperature of about 800 ° C. after baking the base at a temperature of 1,200 ° C. or higher and glazing using a low-heat degree koji. Rakuyaki burns the substrate at a temperature of about 800 ° C. to 1,000 ° C., and then burns it at a temperature of 800 ° C. to 900 ° C. with a low-temperature glazed glaze.

  As mentioned above, low-fired flames such as upper paints, shampoos, and easy-fired glazes are materials that are exposed on the outermost surface of the ceramics. ), Depending on the composition of the raw materials used for the base (base or high-temperature fire). In addition, as an indispensable condition when firing, the upper paint and the low-temperature flame are sufficiently covered with the base, the upper paint and the low-temperature flame are not devitrified, the upper paint and the low-temperature flame It is required that defects such as peeling between the base material and the substrate do not occur, and color development by the colorant in the upper paint or low-temperature fire is not hindered. Furthermore, in recent years, when ceramics are used as tableware, it has sufficient acid resistance against acidic foods such as vinegared foods, and has sufficient alkali resistance against alkaline detergents for dishwashers. High chemical durability is required for the flame. In addition, the upper paint and the low firepower are also required to have good handling so that the craftsman can easily perform the painting work. That is, if the workability of overpainting is reduced, it takes extra work time, leading to high costs. As described above, the properties that should be included in ceramic top paints and low-temperature firewood are baked at a relatively low temperature such as 650 ° C. to 900 ° C. and have a glossy appearance, and devitrified during firing. The transparency will not be lost, there will be no defects such as peeling off the substrate, the colorant will be sufficiently colored, acid resistance, alkali resistance, water resistance, and detergent resistance. Therefore, it is required to have a high chemical durability and a material that is easy to use for painters.

  By the way, leaded paints and leaded glazes are relatively well equipped with the above-mentioned properties required for top paints and low-fired glazes. However, in recent years, ceramic products that have been overpainted or glazed using leaded top paint or low-temperature firewood need to be subjected to lead elution inspection at the time of shipment, which increases the cost of the product. There is a problem that leads to. In the first place, as market needs in recent years, it has been demanded to use lead-free upper paint and low-temperature firewood for decorating ceramics. Accordingly, various proposals have been made for lead-free upper paints and low-temperature firewood, which are also provided to the market. For example, lead-free paint for ceramics containing a coloring agent in a frit containing silicon oxide, boron oxide, alkali metal oxide, zinc oxide, zirconium oxide, aluminum oxide and niobium oxide or tantalum oxide in a certain weight range. Is proposed (for example, see Patent Document 1), each containing silicon oxide, aluminum oxide, boron oxide, potassium oxide, sodium oxide, lithium oxide, calcium oxide, zinc oxide, and magnesium oxide in a certain range of weight proportions, In addition, a lead-free paint for painting produced by blending a pigment and a metal oxide with a low-melting-point frit containing fluorine in a certain ratio of the content of boron oxide to the content of silicon oxide. It has been proposed (see, for example, Patent Document 2). In addition, when lead-free paint containing chromium oxide is used to paint on ceramics, and when heated and fired directly in a direct heating type firing furnace, air or oxygen is supplied into the firing furnace in the first half of the firing zone. There has been proposed a baking method with a picture in which the minimum concentration of oxygen in the atmosphere is set to a certain value or more (see, for example, Patent Document 3).

Japanese Patent No. 2975318 (page 2-3) Japanese Patent No. 4022511 (page 2-4) Japanese Patent No. 4284403 (page 3-4)

  However, the various lead-free upper paints and low-temperature flames that have been proposed so far are not suitable for firing at low temperatures, those that peel off from the base, those that are not chemically durable, and have a low specific gravity. Therefore, there have been no lead-free upper paint and lead-free low-fired firewood that satisfy all the above-mentioned requirements for ceramic upper paint and low-fired firewood.

  In particular, it is necessary to lower the glass transition temperature (glass transition point) of the frit, which is a glass material that constitutes paints and glazes, in order to enable baking of the upper paint and low-temperature firewood at low temperatures. In addition, a large amount of alkali metal, alkaline earth metal or boron is added to the frit. In this case, the glass transition point of the frit is lowered by the inclusion of a large amount of alkali metal or alkaline earth metal, but the coefficient of thermal expansion of the frit is increased. Peeling easily occurs. In addition, the glass transition point of the frit is lowered by blending a large amount of boron, but the chemical durability of the frit is lowered. In addition, lead-free upper paint and low-fired firewood use a crushed frit (glass powder), so use a brush compared to traditional leaded paints and leaded low-fired firewood. The workers pointed out that the growth of paints and glazes was poor during painting and glazing. In order to improve this workability, attempts have been made to use an organic binder that decomposes during firing, but it cannot be said that sufficient results have been achieved.

Of the above-mentioned problems, the phenomenon of peeling between the upper paint and the low-heat-haze and the ground will be described in more detail.
When the difference between the coefficient of thermal expansion of the base and the coefficient of thermal expansion of the upper paint or the low heating point is large, the upper paint or the low heating point is easily peeled off from the base during low-temperature firing. Among these, when the thermal expansion coefficient of the upper paint or the low-fired firewood is larger than the thermal expansion coefficient of the base, the following phenomenon occurs in the process of firing the upper paint or the low-fired firewood and lowering the temperature.

  By heating and baking, the upper paint and the frit (glass) in the low-temperature flame are melted, and the melt is integrally bonded to the base. Later, as the temperature of the ceramics decreases, the coefficient of thermal expansion of the upper paint and low-fired firewood is large, which increases the difference in shrinkage from the fired base. Compressive stress is generated between the fire point and the substrate. When this compressive stress is small, cracks are made on the upper paint on the ceramic surface and the low-temperature fire pot, and the stress is relieved by creating a gap generally called penetration. On the other hand, when the compressive stress is large, peeling of the upper paint and low-temperature fire occurs.

  On the other hand, if the thermal expansion coefficient of the base is greater than the thermal expansion coefficient of the upper paint or the low heating point, and a larger compressive stress is generated in the upper paint or the low heating point, the upper part is increased by the compressive stress acting from the base. A phenomenon occurs in which paints and low-temperature firewood peel off from the ground. In particular, in a process in which baking is repeated a plurality of times after overpainting or glazing, the substrate is stressed many times, and thus a peeling phenomenon is more likely to occur. In addition, as the thickness of the upper paint or the low-temperature layer increases, the exfoliation phenomenon becomes more prominent.

  This invention has been made in view of the circumstances as described above, is well baked by firing at a low temperature, maintains a sense of transparency without devitrification during firing, there is no risk of peeling to the base, Satisfies almost all the requirements for ceramic top paints and low-temperature fires, such as excellent chemical durability such as acid resistance, alkali resistance, water resistance, and detergent resistance, and is easy to use for workers. The purpose is to provide such lead-free paints and lead-free low-heat flames.

The invention according to claim 1 is a powdered frit (glass powder) having a predetermined oxide composition, a glassy powder having a non-crystalline particle shape, and a coloring component such as a pigment or a metal oxide. And a low-melting-point lead-free glass composition for ceramics, such as a low-fired pottery, such as an upper paint, a crossing agent, and an easy shochu. The composition of powdered frit, the SiO ₂ by mol% from 40.3 to 67.8, _Al 2 _{O 3} of 1.1 to _3.9, a B 2 _{O 3} 10.5 to 25.3, LiO ₂ of 7.7 to 11.6, Na ₂ O and from 3.5 to 6.1, _{K 2} O of 2.1 to 4.2, the ZnO 5.0 to 8.5, respectively contain, and The ratio of the combined content of SiO ₂ and Al ₂ O ₃ is 43 mol% to 70 mol%. The glassy powder has a high chemical resistance to acids and alkalis and a thermal expansion coefficient of 1 × 10 ^{−6 to} 5 × 10 ⁻⁶ , and has a refractive index equivalent to or close to the refractive index of the frit, and It has a higher fire resistance than the frit, and is blended at a ratio of 3 g to 30 g when the content of the frit is 100 g. The said coloring component is mix | blended in the ratio of 1%-30% with respect to the weight of the whole glass composition.

  The invention according to claim 2 is characterized in that, in the low melting point lead-free glass composition according to claim 1, the colored component contains Bengala whose particle surface is coated with a heat-resistant oxide.

The invention according to claim 3 is a powdery frit (glass powder) having a predetermined oxide composition and containing coloring components such as pigments and metal oxides, and glass having an amorphous particle shape and a plate shape. And a low melting point lead-free glass composition for ceramics. The composition of powdered frit, the SiO ₂ by mol% from 40.3 to 67.8, _Al 2 _{O 3} of 1.1 to _3.9, a B 2 _{O 3} 10.5 to 25.3, LiO ₂ of 7.7 to 11.6, Na ₂ O and from 3.5 to 6.1, _{K 2} O of 2.1 to 4.2, the ZnO 5.0 to 8.5, respectively contain, and The combined content of SiO ₂ and Al ₂ O ₃ is 43 mol% to 70 mol%, and the frit is colored so that the compounding ratio with respect to the weight of the entire glass composition is 1% to 30%. Contains ingredients. The glassy powder has a high chemical resistance to acids and alkalis and a thermal expansion coefficient of 1 × 10 ^{−6 to} 5 × 10 ⁻⁶ , and has a refractive index equivalent to or close to the refractive index of the frit, and It has a higher fire resistance than the frit, and is blended at a ratio of 3 g to 30 g when the content of the frit is 100 g.

  The invention according to claim 4 is characterized in that in the low melting point lead-free glass composition according to claim 1 or 3, manganese silicate is contained as the coloring component.

The invention according to claim 5 is a powdery frit (glass powder) having a predetermined oxide composition and containing coloring components such as pigments and metal oxides, and glass having an amorphous particle shape and a plate shape. A low-melting-point lead-free glass composition for ceramics is formed by including a powdery powder and a coloring component different from the coloring component contained in the frit. The composition of powdered frit, the SiO ₂ by mol% from 40.3 to 67.8, _Al 2 _{O 3} of 1.1 to _3.9, a B 2 _{O 3} 10.5 to 25.3, LiO ₂ of 7.7 to 11.6, Na ₂ O and from 3.5 to 6.1, _{K 2} O of 2.1 to 4.2, the ZnO 5.0 to 8.5, respectively contain, and The combined content of SiO ₂ and Al ₂ O ₃ is 43 mol% to 70 mol%, and the frit is colored so that the compounding ratio with respect to the weight of the entire glass composition is 1% to 30%. Contains ingredients. The glassy powder has a high chemical resistance to acids and alkalis and a thermal expansion coefficient of 1 × 10 ^{−6 to} 5 × 10 ⁻⁶ , and has a refractive index equivalent to or close to the refractive index of the frit, and It has a higher fire resistance than the frit, and is blended at a ratio of 3 g to 30 g when the content of the frit is 100 g. The coloring component contained in the frit and the other coloring component are blended at a ratio of 1% to 30% with respect to the weight of the entire glass composition.

  The invention according to claim 6 is the low-melting-point lead-free glass composition according to claim 5, characterized in that it contains Bengala whose particle surface is coated with a heat-resistant oxide as the other coloring component. .

  The invention according to claim 7 is the low melting point lead-free glass composition according to claim 5, characterized in that it contains manganese silicate as the other coloring component.

  The invention according to claim 8 is the low melting point lead-free glass composition according to any one of claims 1 to 7, wherein amorphous glass-like particles derived from clay such as kaolin are used as the glassy powder. It is characterized by.

  The invention according to claim 9 is the low melting point lead-free glass composition according to claim 8, wherein the amorphous plate-like particles derived from clay are calcined kaolin or metakaolin.

  The invention according to claim 10 is the low melting point lead-free glass composition according to any one of claims 1 to 9, wherein the blending ratio of the glassy powder to the frit is 100 g of the frit. 5 to 20 g.

  The invention according to claim 11 is the low-melting point lead-free glass composition according to any one of claims 1 to 10, further comprising a powder containing a zirconium compound.

  The invention according to claim 12 is the low melting point lead-free glass composition according to claim 11, wherein the zirconium compound is zircon, and the zircon powder is blended in a proportion of 5% or less with respect to the total weight. It is characterized by.

  In the low melting point lead-free glass composition for ceramics of each of the inventions according to claim 1, claim 3 and claim 5, the powdered frit having a predetermined oxide composition is at a relatively low temperature of 650 ° C to 900 ° C. It is a material excellent in chemical durability such as baking, acid resistance, alkali resistance and the like. Moreover, the glassy powder mixed with the frit also has high chemical durability. Furthermore, the frit is excellent in adhesiveness with the base, and firmly adheres to the base by firing.

The frit having the above composition has a thermal expansion coefficient of 7 × 10 ⁻⁶ to 1 × 10 ^−5, which is larger than the thermal expansion coefficient of a general base, but the thermal expansion of the glassy powder mixed in the frit. The coefficient is as small as 1 × 10 ^{−6 to} 5 × 10 ⁻⁶ . For this reason, as a whole glass composition, the difference of the thermal expansion coefficient and the general thermal expansion coefficient of a foundation | substrate becomes small. Therefore, although it becomes advantageous for prevention of the peeling phenomenon of the glass composition with respect to a foundation | substrate, the largest effect by the glass-like powder being mixed is as follows.

  The frit having the above composition can be seized at a relatively low temperature. On the other hand, since the glassy powder has a high fire resistance, the glass composition obtained by mixing the two is fired at a relatively low temperature of 650 ° C. to 900 ° C. However, the frit and the glassy powder do not react and become uniform. For this reason, in the melt of the glass composition or the solidified product thereof, the frit component and the glassy powder component are in a phase-separated state, so that the phase interface is likely to be the starting point of fracture (crack). Therefore, even if a compressive stress is generated between the glass composition and the base in the process of firing the glass composition and lowering the temperature, the stress is alleviated by cracking the glass composition and causing penetration. And since the glass composition is firmly bonded to the base, the glass composition is peeled off from the base only by penetration even when baking is repeated a plurality of times after painting or glazing. There is nothing. Furthermore, when the glassy powder is mixed, when used as an upper paint or a low-fired firewood, the paint and glaze have a good elongation during painting and glazing with a brush, and this glass composition Is convenient for the operator. This is considered to be because the particle shape of the glassy powder is plate-like. In addition, since the refractive index of the frit and the refractive index of the glassy powder are equal or close to each other, transparency is maintained without devitrification during firing.

  As described above, according to each of the inventions according to claim 1, claim 3, and claim 5, lead-free upper paint and lead-free low heat intensity that satisfy almost all the requirements for top paint for ceramics and low heat intensity firewood You can get firewood.

In the glass composition of each invention according to claim 2 and claim 6, the heat resistant oxide is coated on the surface of bengara particles used as a coloring component (or another coloring component). The reaction between the frit and bengara is prevented, and the grain growth of bengara is suppressed. As a result, a good color is produced, and the original bright red color appears.
That is, Bengala is a fine particle of hematite (α-Fe ₂ O ₃ ), which is a kind of iron oxide, and it is known that the red color tone of Bengala changes depending on the particle size and the firing temperature. The grains grow and the bengara and frit react at high temperatures, resulting in a dark red or brown color. The grain growth of Bengala proceeds by heating and baking the glass composition containing it. For this reason, when the firing temperature is increased, the color of the red rose becomes dark, which has been a problem in the past. In the glass compositions of the inventions according to claim 2 and claim 6, since the surface of the particles of Bengala is coated with a heat-resistant oxide, the reaction between the frit and the Bengala in the glass composition is prevented. Moreover, the grain growth of the red rose is suppressed, and as a result, the red rose develops a good color.

In the glass composition of each invention according to claim 4 and claim 7, when the manganese compound used as the coloring component (or another coloring component) is manganese silicate, manganese dioxide is used for overpainting or glazing. The foaming phenomenon at the time of firing as seen when using is not caused.
Here, the reason why the foaming phenomenon seen when manganese dioxide is used is considered as follows. That is, the oxidation number of manganese (the valence of manganese ions) decreases as the firing temperature increases. As for manganese oxide, manganese dioxide (MnO ₂ ) having an oxidation number of 4 is stable near room temperature, but the oxidation number decreases with heating. When a frit containing manganese dioxide is baked at a temperature of about 900 ° C., for example, it changes to dimanganese trioxide (Mn ₂ O ₃ ) having an oxidation number of 3, and furthermore, trioxide tetraoxide having oxidation numbers of 2 and 3. It changes to manganese (Mn ₃ O ₄ ). In the process of changing their oxidation number, oxygen is generated (4MnO ₂ → 2Mn ₂ O ₃ + O ₂ , 6Mn ₂ O ₃ → 4Mn ₃ O ₄ + O ₂ ), and the oxygen is released into the frit melt. At this time, when the viscosity of the melt is sufficiently high, the melt is solidified while leaving a trace of foaming, and a glass composition containing bubbles is obtained. On the other hand, when a frit containing manganese silicate (MnSiO ₃ ) having an oxidation number of 2 is baked at a temperature of, for example, 650 ° C. to 900 ° C., the state in which the oxidation number of manganese remains 2 is maintained, and the foaming phenomenon Does not happen. Then, manganese silicate reacts with the frit during firing, and manganese is ion-dissolved in the frit to generate ionic color.

  In the glass composition of the invention according to claim 8, by using amorphous plate-like particles derived from clay such as kaolin as the glassy powder, the invention according to each of the inventions according to claim 1, claim 3 and claim 5 is used. The effect is definitely obtained.

  In the glass composition of the invention according to claim 9, the effects of the inventions according to claims 1, 3, and 5 are preferably obtained by using calcined kaolin or metakaolin as the glassy powder.

  In the glass composition of the invention according to claim 10, the above-described effects of the inventions according to claims 1, 3, and 5 are more preferably obtained.

  In the glass composition of the invention according to the eleventh aspect, zirconium is partially melted in the glass when it is fired. As a result, the chemical durability of lead-free upper paint and lead-free low-temperature flame is enhanced by the action of zirconium. It will be improved.

  In the glass composition of the invention according to claim 12, the above-described effect by the invention according to claim 11 can be reliably obtained.

Hereinafter, preferred embodiments of the present invention will be described.
Low melting point lead-free glass composition for ceramics according to the present invention, that is, low-melting point lead-free paint that does not contain lead and has a low melting point, such as a low melting point lead-free paint, a crossing agent, and an easy shochu powder, a powder having a predetermined oxide composition And a glassy powder having an amorphous particle shape and a plate shape. Coloring components such as pigments and metal oxides may be contained in the upper paint or low-temperature flame as a separate material from the colorless powdered frit, or contained in the frit and containing the coloring component. A powdery frit may be formed, or may be contained in the frit to form a powdered colored frit, and may be contained as a separate material from the powdered colored frit.

The powdered frit is sufficiently low in chemical durability such as acid resistance, alkali resistance, water resistance, and detergent resistance, and is a low glass suitable for baking temperatures of around 800 ° C. used for ceramic overpainting and glazing. A glass powder having a transition temperature. As a frit having such properties, a glass powder having the following composition range was developed. That is, in terms of mol%, SiO ₂ is 40.3 to 67.8, Al ₂ O ₃ is 1.1 to 3.9, B ₂ O ₃ is 10.5 to 25.3, and LiO ₂ is 7.7 to 11.6, Na ₂ O 3.5-6.1, K ₂ O 2.1-4.2, ZnO 5.0-8.5, respectively, and SiO ₂ and Al ₂ O _A powdery frit having a total content ratio of ₃ of 43 mol% to 70 mol% was prepared. In this frit, the content of Al ₂ O ₃ is 4.0 mol% or less, and the molar ratio of SiO _{2 to} the content of B ₂ O ₃ is 0.15 or more. These composition range values are obtained by repeating the experiment. This frit has a relatively large coefficient of thermal expansion, such as 7 × 10 ⁻⁶ to 1 × 10 ⁻⁵ .

  Such a powdered frit is prepared by mixing and mixing raw materials such as feldspar, silica, and borax so as to have a desired glass composition, and then heating the mixture to a temperature of 1,200 ° C. to 1,500 ° C. It is obtained by a production method in which the melt is melted and then the melt is rapidly cooled, and the obtained solid is pulverized so that the average particle size is, for example, about 0.3 μm to 10 μm. A powdered frit containing a coloring component (powdered colored frit) is prepared by mixing raw materials and then mixing a coloring component composed of a transition metal oxide or a colored rare earth element oxide or both into the composition. Then, the mixture containing the coloring component is heated and melted in the same manner, and the solid is pulverized after rapid cooling.

A glassy powder having an amorphous particle shape and a plate shape has high chemical durability such as acid resistance and alkali resistance, and is a sufficiently small value compared to the above frit, 1 × 10 ^{−6 to} 5 × 10 ^6. It is a powder having a glass composition having a thermal expansion coefficient of ^-6 . The glassy powder may have any composition or mineral as long as it has a refractive index that is equivalent to or close to the refractive index of the frit. For example, kaolinite, halloysite, and sericite, which are natural clay minerals, are suitable from the viewpoint of low cost and relatively easy procurement. Most of these clay minerals are silicon oxide and aluminum oxide, and since the content of silicon oxide is close to that of frit, its refractive index is considered to be equal to or close to the refractive index of frit. On the other hand, clay minerals have a high fire resistance because they have a low content of alkali metals, alkaline earth metals, boron, and the like.

  The clay mineral powder is a crystalline material as it is, but it is amorphized (vitrified) at a temperature of about 400 ° C to 700 ° C during baking of the upper paint and low-temperature firewood. It may be possible to use the substance as it is. However, kaolinite and sericite are highly cohesive because they contain a large amount of hydroxyl groups in their molecules, and therefore cannot be uniformly mixed with powdered frit. Further, when firing in a state where the plate-like particles of kaolinite or sericite are aggregated, there is a problem that after baking, the upper paint and the low heating point become opaque and the transparency is impaired. Therefore, in the present invention, a powder obtained by baking a crystalline substance in advance to be amorphous is used.

  For example, since kaolinite that has been subjected to heat treatment and fine pulverization is on the market for papermaking, if it is used as a raw material for glassy powder, it is preferable in terms of quality and cost. As the glassy powder, one having an average particle diameter of, for example, about 0.3 μm to 10 μm is used. Such raw materials are manufactured by various companies. For example, metakaolin and calcined kaolin manufactured and sold by Imerys Minerals Japan Co., Ltd. can be used as raw materials for glassy powder. The powders of metakaolin and calcined kaolin are obtained by pulverizing raw kaolin after heat treatment, and the names differ depending on the treatment temperature, but both are amorphous. Further, since metakaolin and calcined kaolin are produced from natural raw materials, other elements and crystals are mixed in, but since they are in a very small amount, they can be used without any problem in the glass composition according to the present invention.

  Regarding the mixing ratio of the glassy powder to the powdered frit, the glassy powder is preferably blended at a ratio of 3 g to 30 g when the frit content is 100 g. More preferably, when the frit content is 100 g, the glass powder content is 5 g to 20 g. When the blending amount of the glassy powder is less than the above numerical range, the effect of preventing the upper paint and the low-temperature flame from peeling off from the ceramic base is reduced. On the other hand, if the blending amount of the glassy powder is larger than the above numerical range, the upper paint and the low-temperature flame are not densified and glossiness cannot be obtained. In addition, as the blending amount of the glassy powder is increased, a glossy upper paint and a low flame degree can be obtained by increasing the firing temperature. However, at a firing temperature of about 800 ° C., the content of frit is 100 g. It is appropriate to mix the glassy powder at a ratio of 5 g to 10 g.

  The amount of the coloring component blended in the powdered frit and the glassy powder is set so that the blending ratio with respect to the total weight of the glass composition is 1% to 30%. Even when the colored component is contained in the frit to form a powdered colored frit, the colored component is blended so that the blending ratio with respect to the total weight of the glass composition is 1% to 30%. . Thus, since there are not so many compounding quantities of a coloring component, it is not necessary to change the mixing ratio of the glassy powder with respect to the above-mentioned powdery frit according to the kind of coloring component.

  In the case of preparing a glassy composition (upper paint or low-temperature flame) by mixing a colored powder frit or a powdered colored frit and a glassy powder together with a colored component, a corundum type (manganese pink) is used as the colored component. , Chromium alumina green, iron red, etc.), rutile type (chrome tin lilac, vanadium tin yellow, tin oxide, etc.), fluorite type (vanadium zirconium yellow, etc.), spinel type (sea ridge, peacock, Taisho black, chrome alumina pink) Etc.), garnet type (Victoria green etc.), sphene type (chrome tin pink, chrome titanium etc.) and zircon type (vanadium blue, praseodymium yellow etc.) crystal structures existing ceramic pigments, metal oxide pigments, Pink (round circle) pigments in which silver particles or gold particles are dissolved are used. In this case, when the pigment is dispersed (suspended) in the glass, the upper paint and the low-temperature fire color develop. In addition, transition metal oxides such as copper oxide, iron oxide, and cobalt oxide are also used.

  Here, in the case of using Bengala, which is a fine particle of hematite, which is a kind of iron oxide, as the red pigment, a Bengala particle surface coated with a heat-resistant oxide may be used. As the heat-resistant oxide, silicon oxide, aluminum oxide, zirconium oxide, composite oxide of silicon oxide and aluminum oxide, composite oxide of silicon oxide and zirconium oxide, or the like is used. In this way, by using the bengara whose particle surface is coated with a heat-resistant oxide, the reaction between the frit and the bengara in the glass composition is prevented, and the grain growth of the bengara is suppressed. As a result, a good color is produced, and the original bright red color appears.

  In addition, when manganese dioxide is used as a coloring component, many foaming phenomena are observed during baking during overpainting and glazing. Therefore, when a manganese compound is used as the coloring component, it is preferable to use manganese silicate having an oxidation number of 2. When manganese silicate is used as the coloring component, no foaming phenomenon occurs during firing.

  In addition, when a powdery colored frit containing a coloring component in a frit and a glassy powder are mixed to prepare an upper paint or a low-temperature flame, a powdered colored frit and a glassy powder are different from each other. In the case of preparing an upper paint or a low-temperature flame by mixing with coloring components, transition metal oxides such as copper oxide, iron oxide, cobalt oxide, silver particles and gold particles are included as coloring components to be contained in the frit. A solid solution pink (round circle) pigment is used. When a transition metal oxide is used as the coloring component, the coloring component reacts with the glass component and is ion-dissolved in the glass, resulting in ionic coloring. In addition, when a circle-shaped pigment is used as the coloring component, silver particles and gold particles are dispersed in the glass and color is developed.

The low melting point lead-free glass composition includes a powdery frit and a glassy powder and a coloring component, a powdery colored frit and a glassy powder, or a powdery frit and a glassy powder and a coloring component. In addition, the low-melting-point lead-free glass composition may be configured to include a powder containing a zirconium compound. Examples of the zirconium compound include zircon (ZrSiO ₄ ) alone, which is a composite compound of silicon oxide and zirconium oxide, or prosodymium yellow (ceramic pigment of a ceramic pigment) in which praseodymium (Pr) ion, which is one of rare earth elements, is dissolved in zircon. 1 type) is used. The zircon powder is blended in a proportion of 5% or less with respect to the total weight of the glass composition. In the low melting point lead-free glass composition in which the zircon powder is mixed as described above, zirconium is partially melted in the glass when it is fired, and lead-free upper paint and lead-free low-flame temperature are reduced by the action of the melted zirconium. This further improves the chemical durability.

  The powder of the glassy composition constituted as described above is added to a solvent and a binder, dissolved in a paste form, and used for ceramic top painting and glazing. That is, the obtained paste liquid is applied onto a ceramic and baked at a temperature of about 800 ° C. for baking. As a result, it is possible to obtain an upper paint and a low fire degree flame having high transparency and gloss and high chemical durability.

[Preparation of powdered frit]
As raw materials, natural minerals such as silica and limestone, and boric acid, aluminum hydroxide, zinc oxide, lithium carbonate, sodium carbonate and potassium carbonate (all are primary reagents) are used, and each of these raw materials is used in predetermined amounts. Weighed and mixed them uniformly. The obtained mixture was put into a crucible having a capacity of 170 cc and heated to a temperature of 1,300 ° C. over 17 hours by an electric furnace to melt the mixture. Thereafter, the crucible containing the melt was taken out of the furnace, and the melt was poured into water to quench it. The obtained massive frit was roughly crushed so that the particle size was 3 mm or less, and after sufficiently drying it, the crushed material was ground for about 10 minutes using a planetary ball mill (300 rpm). As a result, a powdered frit having an average particle diameter (median diameter) of about 8 μm was obtained. In this way, four types of powdered frit having different compositions were prepared. Table 1 shows the composition ratio of each frit (No. 1 to No. 5) in terms of mol%, together with the thermal expansion coefficient of each frit.

[Preparation and baking of basic glaze]
As the glassy powder, calcined kaolin (trade name: Polestar200R) manufactured by Imerizu Minerals Japan Co., Ltd. was used. 1-No. A basic glaze was prepared by adding 7.5 parts of glassy powder to 100 parts of powdery frit No. 5. After adding water and funnel to the obtained powder of basic glaze and dissolving it in a paste form, the paste solution was applied in a sheet form on the surface of a porcelain plate that had been fired at a high temperature, and then the temperature rising time was 5 hours. The basic glaze was baked and baked at a temperature of 680C to 900C. The evaluation results are shown in Table 2. Table 2 shows the thermal expansion coefficient of the basic glaze in each composition, the gloss and transparency of the glaze when the basic glaze was baked on a porcelain plate (thermal expansion coefficient: 5.5 × 10 ⁻⁶ ), presence or absence of penetration, In addition, the appearance of the acid when the acid resistance test (immersion in 4% acetic acid at a temperature of 24 ° C. for 24 hours) and alkali resistance test (immersion in a 0.5% aqueous sodium carbonate solution at a temperature of 95 ° C. for 3 hours) Show each change.

  As shown in Table 2, the gloss and transparency after baking were good for any of the basic glazes. In addition, the results of the acid resistance test and alkali resistance test showed no change in gloss and transparency, and the chemical durability was good. Furthermore, no glaze peeling occurred even when firing was repeated four times.

[Comparative example]
As a comparative example, no. 1-No. After adding water and funnel to the powdered frit of No. 5 and dissolving it in a paste form, the paste solution was applied in a planar form on the surface of a porcelain plate that had been fired at a high temperature. The frit was baked and baked at a temperature of from 0C to 900C. The fired product of the frit was sufficiently high in chemical durability, but peeling occurred when fired four times. From this result, it became clear that the addition of glassy powder greatly contributes to prevention of glaze peeling at the time of multiple firings.

[Preparation of upper paint]
No. A basic glaze was prepared by adding 10 parts of the above glassy powder (baked kaolin) to 100 parts of the powdery frit of No. 4. A pigment was added to this basic glaze to prepare three color glazes of cyan, magenta and yellow. That is, 1 part of peacock BG5 is added to 100 parts of basic glaze to prepare a cyan glaze, 5 parts of round circle is added to 100 parts of basic glaze to prepare a magenta glaze, and praseodymium yellow is added to 100 parts of basic glaze. Was added to prepare a yellow color glaze. Using these three color glazes, No. 1 shown in Table 3 was obtained. 4-1. 4-6 top paint was prepared. The numbers in Table 3 indicate the blending ratio (unit: part).

  No. obtained above. 4-1. Water and funnel are added to 4-6 powdery upper paint to dissolve it into a paste, and the paste solution is applied in a planar shape onto a ground plate of a porcelain plate that has been fired at a high temperature. The upper paint was baked and baked at a temperature of 680 ° C. to 900 ° C. for a time. As a result, it was confirmed that it is possible to prepare an upper paint that develops various colors by blending various pigments into a mixture of powdery frit and glassy powder.

[Preparation of red top paint using Bengala]
No. A base glaze was prepared by adding 7.5 parts of the above glassy powder (baked kaolin) to 100 parts of the powdery frit No. 4, and silica (SiO ₂ ) was coated on the particle surface of 100 parts of the basic glaze. The upper paint was prepared by adding 20 parts of red bengara. Bancha was added to the powdery upper paint to dissolve it into a paste, which was thoroughly sprinkled in a mortar for 15 minutes. The obtained paste solution was applied in a planar shape on the lower surface of a porcelain plate that had been fired at high temperature, and then the upper paint was fired at a temperature of 680 ° C. to 900 ° C. for 5 hours. As a result, a bright orange-colored upper paint was obtained as the color difference value * a39 * b34 with respect to the color difference value * a30 * b35 of a red paint using a commercially available bengara.

[Preparation of colored frit for amber color shochu]
No. 4 parts of powdery frit No. 4 were added with 10 parts of iron hydroxide and 4 parts of manganese silicate and fired at a temperature of 900 ° C. As a result, it was possible to prepare a colored frit for an amber-colored shochu without foaming during firing.

  For the upper paint obtained in Example 2 and Example 3 described above, acid resistance test (immersion in 4% acetic acid at a temperature of 24 ° C. for 24 hours), alkali resistance test (95 ° C. in 0.5% aqueous sodium carbonate solution) And a detergent resistance test (washing 1,000 times with a commercial dishwasher). As a result, no deterioration in the glossiness of the upper paint was observed. Moreover, about the upper paint obtained in Example 2 mentioned above, baking was repeated 4 times, but peeling of the upper paint was not seen. From these results, it was confirmed that the chemical durability and non-peelability of the upper paint were maintained even when a pigment was added as a coloring component to the powdered frit and glassy powder.

[Preparation of upper paint mixed with zircon]
No. 1 obtained in Example 1. 7.5 parts of the above glassy powder (calcined kaolin) is added to 100 parts of the powdered frit of No. 5, and praseodymium yellow (zircon in which praseodymium ions are dissolved) is added to the mixed powder. The upper paint was prepared by mixing 3% with respect to the total weight of the composition. Water and funnel are added to the resulting powdery upper paint to dissolve it into a paste, and the paste is applied to the surface of the porcelain plate that has been fired at a high temperature, and then the temperature rise time is 5 hours. The upper paint was baked and baked at a temperature of about 800 ° C.

  As a result of conducting an alkali resistance test on an alkaline detergent for dishwashers on a porcelain plate that has been overpainted and baked, as compared with a glass composition that does not contain praseodymium yellow just by mixing a glassy powder into a frit, Alkali resistance was improved in the upper paint mixed with praseodymium yellow.

  The present invention may be widely used in a ceramic manufacturing industry, a ceramic top paint, particularly a Japanese paint manufacturing industry, a glaze manufacturing industry, and a frit manufacturing glass manufacturing industry.

Claims (12)

In terms of mol%, SiO ₂ is 40.3 to 67.8, Al ₂ O ₃ is 1.1 to 3.9, B ₂ O ₃ is 10.5 to 25.3, LiO ₂ is 7.7 to 11. 6, containing Na ₂ O 3.5 to 6.1, K ₂ O 2.1 to 4.2, ZnO 5.0 to 8.5, and SiO ₂ and Al ₂ O ₃ A powdered frit having a total content ratio of 43 mol% to 70 mol%,
Particle shape is amorphous and plate-like, has high chemical durability against acids and alkalis, and has a thermal expansion coefficient of 1 × 10 ^{−6 to} 5 × 10 ⁻⁶ , which is equal to or close to the refractive index of the frit. A glassy powder having a refractive index and a high fire resistance compared to the frit, and blended in a ratio of 3 g to 30 g when the content of the frit is 100 g;
A coloring component blended at a ratio of 1% to 30% with respect to the total weight;
A low-melting-point lead-free glass composition for ceramics, comprising: The low-melting-point lead-free glass composition for ceramics according to claim 1, wherein the coloring component contains Bengala whose particle surface is coated with a heat-resistant oxide. In terms of mol%, SiO ₂ is 40.3 to 67.8, Al ₂ O ₃ is 1.1 to 3.9, B ₂ O ₃ is 10.5 to 25.3, LiO ₂ is 7.7 to 11. 6, containing Na ₂ O 3.5 to 6.1, K ₂ O 2.1 to 4.2, ZnO 5.0 to 8.5, and SiO ₂ and Al ₂ O ₃ A powdered frit containing a coloring component such that the ratio of the total content is 43 mol% to 70 mol%, and the blending ratio with respect to the total weight is 1% to 30%;
Particle shape is amorphous and plate-like, has high chemical durability against acids and alkalis, and has a thermal expansion coefficient of 1 × 10 ^{−6 to} 5 × 10 ⁻⁶ , which is equal to or close to the refractive index of the frit. A glassy powder having a refractive index and a high fire resistance compared to the frit, and blended in a ratio of 3 g to 30 g when the content of the frit is 100 g;
A low-melting-point lead-free glass composition for ceramics, comprising: The low melting point lead-free glass composition for ceramics according to claim 1 or 3, comprising manganese silicate as the coloring component. In terms of mol%, SiO ₂ is 40.3 to 67.8, Al ₂ O ₃ is 1.1 to 3.9, B ₂ O ₃ is 10.5 to 25.3, LiO ₂ is 7.7 to 11. 6, containing Na ₂ O 3.5 to 6.1, K ₂ O 2.1 to 4.2, ZnO 5.0 to 8.5, and SiO ₂ and Al ₂ O ₃ A powdered frit having a total content of 43 mol% to 70 mol% and further containing a coloring component;
Particle shape is amorphous and plate-like, has high chemical durability against acids and alkalis, and has a thermal expansion coefficient of 1 × 10 ^{−6 to} 5 × 10 ⁻⁶ , which is equal to or close to the refractive index of the frit. A glassy powder having a refractive index and a high fire resistance compared to the frit, and blended in a ratio of 3 g to 30 g when the content of the frit is 100 g;
A coloring component different from the coloring component contained in the frit;
A low melting point lead-free glass composition for ceramics, wherein the blending ratio of the coloring component contained in the frit and the other coloring component is 1% to 30% based on the total weight. The low-melting-point lead-free glass composition for ceramics according to claim 5, comprising Bengala having a particle surface coated with a heat-resistant oxide as the other coloring component. The low melting point lead-free glass composition for ceramics according to claim 5, which contains manganese silicate as the another coloring component. The low melting point lead-free glass composition for ceramics according to any one of claims 1 to 7, wherein the glassy powder is composed of amorphous plate-like particles derived from clay. The low melting point lead-free glass composition for ceramics according to claim 8, wherein the clay-derived amorphous plate-like particles are calcined kaolin or metakaolin. The low melting point lead-free glass composition for ceramics according to any one of claims 1 to 9, wherein a blending ratio of the glassy powder to the frit is 5 to 20 g when a content of the frit is 100 g. Furthermore, the low melting point lead-free glass composition for ceramics in any one of Claim 1 thru | or 10 in which the powder containing a zirconium compound was contained. The low-melting-point lead-free glass composition for ceramics according to claim 11, wherein the zirconium compound is zircon, and the zircon powder is blended at a ratio of 5% or less with respect to the total weight.