Decorative glass frit

Abstract

To provide a decorative glass frit that can be used for decoration of soda-lime glass and is highly safe.SOLUTION: A decorative glass frit comprises a Ta(V) coloring pigment and a glass frit. The glass frit comprises, in molar percentage, SiO2 of 16-30 mol%, B2O3 of 20-40 mol%, ZnO of 22-35 mol%, and Li2O+Na2O+K2O of 8-14 mol% in total, and is substantially free of a component reactive with the Ta(V) coloring pigment for reduction.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a decorative glass frit, and more particularly to a decorative glass frit suitable for coloring tableware glass made of soda-lime glass. [Background technology]

[0002] Decorative glass frit is used to decorate glass products such as flat glass and tableware. Decorative glass frit contains glass frit and pigment, and is dispersed in a solvent to form a paste-like paint. In this process, an organic binder may be added to adjust the fluidity. When this paint is applied to a glass product and fired, the glass frit softens and becomes integrated with the glass product, forming a decorative layer. Generally, decorative glass frits contain lead to lower the melting point, improve workability, and improve physical and chemical durability. Cadmium-based pigments, which have excellent color development and heat resistance, are used to produce warm colors such as vivid red and yellow-red. However, concerns have arisen about the adverse effects of lead and cadmium on the human body and the environment, and decorative glass frits that do not contain these elements are in demand.

[0003] For example, Patent Document 1 discloses a 50×10 -7 A glass composition for decorative glass with an average linear expansion coefficient (hereinafter simply referred to as the expansion coefficient) of less than 1 / °C and a processing temperature (firing temperature) of 630 to 780°C has been proposed. However, the expansion coefficient of soda-lime glass used in many glass products such as plate glass and tableware is 90 to 110 × 10 -7 / °C, and the firing temperature during decoration is preferably 580°C or lower. Therefore, the glass composition described in Patent Document 1 cannot be used to decorate glass products made of soda-lime glass. Additionally, Patent Documents 2 to 4 and Non-Patent Document 1 propose Ta(V)-based color pigments that do not contain cadmium and have a vivid yellow-red color. However, these Ta(V)-based color pigments have the problem that when mixed with low-melting-point glass frit containing lead, which has traditionally been used to decorate glass tableware, and then fired, the vivid yellow-red color is lost. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 5-270860 [Patent Document 2] Patent No. 4789091 [Patent Document 3] Patent No. 5526424 [Patent Document 4] Japanese Patent Application Laid-Open No. 2011-93743 [Non-patent literature]

[0005] [Non-Patent Document 1] Yuki Ohashi, Kenichiro Oshimoto, Hajime Nagae, Keiji Kusumoto, Toyohiko Sugiyama, Development of New Highly Safe Ceramic Pigments - Tantalum-Based Nitride and Oxynitride Pigments, Ceramic Society of Japan, Ceramics, 46(2011), No.10, pp.847-851 Summary of the Invention [Problem to be solved by the invention]

[0006] An object of the present invention is to provide a highly safe decorative glass frit that can be used to decorate soda-lime glass. [Means for solving the problem]

[0007] The means for solving the problems of the present invention are as follows. 1. Contains a Ta(V)-based color pigment and glass frit, the glass frit contains, in molar terms, 16 to 30 mol% of SiO2, 20 to 40 mol% of B2O3, 22 to 35 mol% of ZnO, and 8 to 14 mol% in total of Li2O+Na2O+K2O; The decorative glass frit is substantially free of components that react with the Ta(V)-based color pigment and are reduced. 2. The decorative glass frit according to 1., characterized in that the glass frit contains, in molar percentages, 1 to 8 mol% Al2O3, 1 to 10 mol% MgO+CaO in total, 0.01 to 1 mol% SnO2, and 0.1 to 2 mol% Gd2O3. 3. The decorative glass frit according to 1. or 2., wherein the Ta(V)-based color pigment is composed mainly of Ta3N5. 4. Glass transition temperature is 500°C or less, and the average linear expansion coefficient is 65 to 85 x 10 -7 The decorative glass frit according to any one of 1. to 3., characterized in that: 5. The Lab color system of the decorative baked part with a thickness of 45 μm or more obtained by baking at a maximum temperature of 580°C for 10 minutes has a brightness of L * 50±15, saturation C * 5. The decorative glass frit according to any one of 1. to 4., wherein the hue angle is 45±15 and the color temperature is 48 or more. [Effects of the Invention]

[0008] The decorative glass frit of the present invention is highly safe because it does not contain lead or cadmium, which are feared to have adverse effects on the human body and the environment. The decorative glass frit of the present invention is substantially free of components that react with and are reduced by Ta(V)-based color pigments, so the color does not become dull even after firing, and the vivid color of the Ta(V)-based color pigment can be reproduced as is. The decorative glass frit of the present invention can achieve a vivid yellow-red color by using a yellow-red Ta(V)-based color pigment without incorporating cadmium. The decorative glass frit of the present invention, which does not contain lead or cadmium, can also be suitably used to decorate glass products that come into contact with the mouth, such as plates and cups. The decorative glass frit of the present invention can be used to decorate soda-lime glass. DETAILED DESCRIPTION OF THE INVENTION

[0009] The present invention relates to a decorative glass frit comprising a Ta(V)-based color pigment and a glass frit, the glass frit containing, in molar terms, 16 to 30 mol% of SiO2, 20 to 40 mol% of B2O3, 22 to 35 mol% of ZnO, and a total of 8 to 14 mol% or more of Li2O+Na2O+K2O, and the glass frit being substantially free of components that will react with the Ta(V)-based color pigment and be reduced. In this specification, "substantially free of" a certain component means that the content of that component is 0.1 mol% or less, and the content of the component that is substantially free is preferably 0.08 mol% or less, and more preferably 0.05 mol% or less. Furthermore, in this specification, "A to B" (A and B are numbers) means a numerical range including A and B, i.e., A or more and B or less.

[0010] Ta(V)-based color pigments Ta(V)-based color pigments include tantalum(V) nitrides such as tantalum nitride (Ta3N5), tantalum oxynitride (TaON), and perovskite-type oxynitride (A 1-v A' v TaO 2-v N 1+v[In the formula, A and A' are one or more cations selected from A: alkaline earth elements, A': rare earth elements, and v is a number from 0 to 1.] Tantalum (V)-based oxynitrides such as these can be used. Tantalum nitride is yellow-red, tantalum oxynitride is greenish-yellow, and perovskite-type oxynitride exhibits a reddish-yellow to yellow color tone depending on its composition. Among these, it is preferable to use tantalum nitride, which has a color tone equivalent to that of conventional cadmium-based pigments.

[0011] Glass frit SiO2 is a network former and has the effect of stabilizing glass, and if its content is less than 16 mol%, the stabilizing effect of glass is insufficient, while if it exceeds 30 mol%, the softening point becomes too high. The SiO2 content is 16 to 30 mol%, and preferably 17 to 25 mol%.

[0012] B2O3 has the effect of stabilizing glass and increasing fluidity. If its content is less than 20 mol%, this effect is insufficient and the expansion coefficient increases. If its content exceeds 40 mol%, the effects of stabilizing glass and increasing fluidity are weakened and water resistance is reduced. The B2O3 content is 20 to 40 mol%, and preferably 25 to 35 mol%.

[0013] ZnO is a component that is effective in stabilizing glass, lowering the softening temperature, and suppressing devitrification. If the content is less than 22 mol%, the effect is insufficient, and if it exceeds 35 mol%, crystallization occurs easily and stable glass cannot be obtained. The ZnO content is 22 to 35 mol%, and preferably 25 to 30 mol%.

[0014] Li2O, Na2O, and K2O have the effect of lowering the softening temperature of glass and increasing its fluidity. If the total content of these elements is less than 8 mol%, the effect of lowering the softening temperature of glass may be insufficient, and the yield point may be 550°C or higher. In addition, the viscosity of the glass increases, reducing its fluidity. If the total content exceeds 14 mol%, adverse effects such as reduced chemical durability, reduced electrical insulation, and an excessively high expansion coefficient may occur. The total content of Li2O + Na2O + K2O is 8 to 14 mol%, and preferably 9 to 12.5 mol%. It is preferable to contain two or more of Li2O, Na2O, and K2O, and more preferably to contain 0.1 mol% or more of Li2O. By blending them in this manner, it is possible to lower the softening temperature of the glass, increase the fluidity, and make the glass transition point of the glass frit 500°C or lower. The ratio of Li2O, Na2O, and K2O is preferably, for example, 4:6:2.

[0015] Al2O3 is effective in improving adhesion to glass and in enhancing chemical durability. Although Al2O3 is an optional component, it is preferably contained in an amount of 1 to 8 mol%, and more preferably 4.0 to 7.5 mol%. If it is contained in an amount of less than 1 mol%, the effect is insufficient, and adhesion to the substrate and water resistance may also be poor. If it exceeds 8 mol%, the softening temperature becomes high, and low-temperature firing may become difficult.

[0016] MgO and CaO are effective in stabilizing the glass. MgO and CaO are optional components, but it is preferable to include them in a total amount of 1 to 10 mol%. If the amount is less than 1 mol%, the glass is likely to devitrify, and crystallization during firing may not be suppressed. If the amount exceeds 10 mol%, the softening temperature may become high, making firing difficult. Furthermore, if the amount exceeds 10 mol%, the expansion coefficient may become 80×10 -7 / °C, and when a film is formed on a soda-lime glass product and fired, cracks and other problems tend to occur.

[0017] Generally, low-melting-point glass frits used to decorate glass products contain lead as a main component to lower the melting point. Lead-free low-melting-point glass frits contain bismuth or other main components. Decorative glass frits made by mixing lead- and bismuth-containing glass frits with Ta(V)-based color pigments can lose their color after firing. This occurs because the lead oxide (PbO) and bismuth oxide (Bi2O3) in the low-melting-point glass frit are reduced by reaction with tantalum nitride, resulting in the precipitation of fine metal particles.

[0018] On the other hand, the glass frit used in the present invention has excellent decorative properties because it is substantially free of components that react with and are reduced by Ta(V)-based color pigments, such as tantalum(V) nitrides such as tantalum nitride, tantalum oxynitrides, perovskite-type oxynitrides, etc. Examples of components that react with and are reduced by Ta(V)-based color pigments, such as tantalum nitride, include lead oxide and bismuth oxide.

[0019] It is preferable to include SnO2 and Gd2O3 to achieve a low melting point without including lead, bismuth, etc. By including SnO2 and Gd2O3, it is possible to provide sufficient low melting performance and form a dense and smooth film. In addition, it can be baked onto the substrate at a temperature of 590°C or less, and the expansion coefficient at 40 to 300°C is 65 to 80 x 10 -7 / ℃. The content of SnO2 is preferably 0.01 to 1 mol %, and more preferably 0.1 to 0.8 mol %. The content of Gd2O3 is preferably 0.1 to 2 mol %, and more preferably 0.3 to 1 mol %.

[0020] The decorative glass frit of the present invention has a glass transition temperature of 500°C or less and an average linear expansion coefficient of 65 to 85 × 10 -7 / °C. When the glass transition temperature and the average linear expansion coefficient satisfy these numerical ranges, the composition can be suitably used for decorating soda-lime glass. The glass transition temperature is more preferably 495°C or lower, and even more preferably 490°C or lower. The lower limit of the glass transition temperature is about 450°C or higher. The lower limit of the average linear expansion coefficient is 70 x 10 -7 / °C or more, and the upper limit is 80 × 10 -7 / °C or less is more preferable.

[0021] The decorative glass frit of the present invention is applied to soda-lime glass and fired at a maximum temperature of 580°C for 10 minutes, and the resulting fired decorative portion with a thickness of 45 μm or more has a value of L * 50±15, saturation C * Preferably, the hue angle h is 45±15 and the color tone of the decorative glass frit of the present invention is within the above-mentioned ranges. When the color tone of the decorative glass frit of the present invention is within the above-mentioned ranges, it can be suitably used as a substitute for cadmium-based pigments. When the decorative glass frit has this color tone, it is preferable that it is substantially free of cadmium, and the cadmium content is more preferably 0.08 mol% or less, and even more preferably 0.05 mol% or less. [Example]

[0022] Glass frit (particle size: approximately 25 μm or less) having the composition shown in Table 1 was mixed with Ta3N5 pigment (particle size: nanometer order) in a ratio of 5 to 13.5 weight percent, and medium was added in an amount equal to the total weight of the glass frit and pigment, followed by kneading to obtain a paste containing decorative glass frit. When preparing the glass frit, a glass sample (bulk) for TMA measurement was prepared, and the glass transition temperature and average linear expansion coefficient were measured using a thermomechanical analyzer (TMA8310, manufactured by Rigaku Corporation) under a compressive load of 98 mN and a heating rate of 5°C / min. The glass transition temperature was measured according to JIS R3102, and the average linear expansion coefficient was measured according to JIS R1618.

[0023] [Table 1]

[0024] The paste obtained was applied to soda-lime glass (Slide Glass S1111 manufactured by Matsunami Glass Industry Co., Ltd.) and fired at a maximum temperature of 580°C for 10 minutes using the temperature profile set below to obtain decorative glass with a thickness of 45 μm or more. - Temperature profile settings Room temperature → 100℃, temperature increase at 10℃ / min 100℃ → 200℃ Temperature increase at 3℃ / min 200℃ → 580℃, temperature increase at 10℃ / min 580℃ 10 minutes 580℃ → 550℃, temperature decreasing at 10℃ / min 550℃ → 450℃, temperature decreasing at 3℃ / min 450℃ → Room temperature Furnace cooling Also, as a reference example, a decorative glass having a thickness of 45 μm or more was obtained in the same manner except that a commercially available glass frit containing Pb (Powder A-11 manufactured by Kinansuzu Glass Co., Ltd.) was used.

[0025] The following evaluations were carried out, and the results are shown in Table 2. ·Color tone The resulting decorated glass was placed on a standard white plate and measured with a spectrophotometer (Murakami Color Research Laboratory Co., Ltd., CMS-35FS, sensor head measurement area: diameter 5 mm, light source: D65, 10° field of view), and analyzed with the accompanying software (ColorSpace for PC) to obtain the lightness L * , saturation C * , and the hue angle h was calculated. Lightness L * 50±15, saturation C * Those with a hue angle of 45±15 or more were marked with a circle, and those without a circle were marked with an ×. ·Peeling resistance A transparent cellophane tape (Nichiban Co., Ltd., No. 405, width 12 mm) was firmly attached to the decorative baked portion of the resulting decorative glass with a finger and then immediately peeled off forcefully. This constituted one cycle, and five cycles were repeated on the same location. A weight loss of 0.1 mg or less was considered acceptable.

[0026] [Table 2]

[0027] The decorative glass frits of Examples 1 and 2 of the present invention maintained a vivid yellow-red color even after firing, and can be used as a substitute for cadmium-based pigments. Furthermore, the decorative glass frits of Examples 1 and 2 were not easily peeled off from soda-lime glass, suggesting their use in decorating soda-lime glass. In contrast, the decorative glass frits of Comparative Examples 1 and 2 and the Reference Example using a commercially available glass frit containing Pb had a saturation (C * ) indicates that the color became dull after firing and the vivid yellow-red color was lost. In addition, the decorative glass frits of Comparative Examples 1 and 2 were easily peeled off from the soda-lime glass.

Claims

1. A Ta(V)-based color pigment and a glass frit are included, The glass frit is, in molar terms, SiO ２ 16 to 30 mol%, B ２ O ３ 20 to 40 mol%, ZnO 22 to 35 mol%, Li ２ O + Na ２ O+K ２ O in total 8 to 14 mol%, Li ２ containing 0.1 mol % or more of O, 1 to 8 mol % of Al 2 O 3 , 1 to 10 mol % in total of MgO+CaO, 0.01 to 1 mol % of SnO 2 , and 0.1 to 2.0 mol % of Gd 2 O 3 ; The decorative glass frit is substantially free of components that react with the Ta(V)-based color pigment and are reduced.

2. The Ta(V)-based color pigment is Ta ３ N ５ 2. The decorative glass frit according to claim 1, characterized in that it comprises:

3. Glass transition temperature is 500°C or less, and the average linear expansion coefficient is 65 to 85 x 10 －７ 3. The decorative glass frit according to claim 1, wherein the temperature is 100°C.

4. The Lab color system of the decorative baked part with a thickness of 45 μm or more obtained by baking at a maximum temperature of 580°C for 10 minutes has a brightness of L ＊ is 50±15, saturation C ＊ 4. The decorative glass frit according to claim 1, wherein the hue angle is 45±15.

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