JP2007031227A - Unleaded overglaze color for pottery and porcelain and method for manufacturing the color - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an unleaded overglaze color for pottery and porcelain, in which a lead component is not incorporated at all and which exhibits excellent durability to an acid while having deep color development and beautiful gloss even when the unleaded overglaze color is formed into the thin layer equal to that of the conventional leaded overglaze color for pottery and porcelain and is suitable for using as a western overglaze color and to provide a method for manufacturing the unleaded overglaze color for pottery and porcelain. <P>SOLUTION: The unleaded overglaze color for pottery and porcelain is manufactured by mixing a pigment, in which lead and cadmium are not incorporated, in a frit containing silicon dioxide, aluminum oxide, boron oxide, an oxide of an alkali metal, zinc oxide, at least one of lanthanum oxide and cerium oxide and at least one of tungsten oxide and molybdenum oxide. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a ceramic upper paint and a method for producing the same, and more particularly to a ceramic upper paint that does not contain lead and cadmium which are harmful substances in the human body.

  Usually, when manufacturing ceramics, after clay clay is unglazed at 700 ° C to 950 ° C, it is then painted with a pigment such as cobalt, manganese, etc., and a glaze is applied on the sketch, at about 1200 ° C to 1300 ° C. Baked. Thereafter, painting is performed with an upper paint made of frit and pigment, and the upper picture is baked at about 800 ° C.

  The above baking conditions are extremely important from the standpoint of maintaining the meltability of the upper paint and maximizing the chemical durability against color development of the pigment, gloss of the paint surface, acid, and the like. (1) The color development of the paint pigment component is maximized, (2) the paint surface has sufficient gloss, and (3) the paint has sufficient acid resistance. is necessary.

  In general, there are “Japanese paint” and “Western paint” in the upper paint for ceramics. In the Japanese paint, there is a transparency after firing, and the upper paint has a thickness of 200 μm or more. After firing, there is a characteristic that there is no transparency and the thickness of the upper paint is a thin film of less than 200 μm. The inventors of the present invention have previously proposed a ceramic upper paint having a pigment content of about 12% by mass (Patent Document 1). However, in western paint, the upper paint layer is a thin film, so that a deep color is developed. Currently, it is added in a large amount of 15 to 30% by mass. Like these Western paints, the upper paint layer is made into a thin film, and if a large amount of pigment is contained in order to exhibit the color developability of the pigment, the frit content is reduced, and if the melting temperature of the frit is not lowered, the dark color is developed. There is a problem that a beautiful gloss on the surface of the paint cannot be obtained while obtaining a color, and the gloss on the surface of the paint is low, and only a paint surface with a feeling of roughness can be obtained. On the other hand, when the amount of the alkali metal oxide component or boron oxide is increased in order to lower the frit melting temperature, there is a problem that the acid resistance is deteriorated.

  Normally, it contains a large amount of lead component to make it a low melting temperature frit, and it is said to be a top paint for ceramics suitable for Western paint, but when used for tableware, the lead component is eluted and its harmfulness is pointed out Has been. For this reason, many studies have been conducted in the past to suppress elution of lead components. For example, a small amount of zirconium silicate is added to the frit in addition to the lead components to improve durability against acids, or in the manufacturing process. In addition, steam is blown during cooling of the upper firing to form a film with durability against acid on the surface of the paint, a kiln packing method is devised, and the furnace temperature is made uniform, and firing is performed during firing. Attempts have been made to reduce the elution of lead components from tableware by improving the firing conditions, such as ventilating the furnace in order to discharge the vapor of the lead components in the furnace outside the furnace.

However, the conventional paint for ceramics basically contains lead components in its chemical composition, so the addition of components that simply improve acid resistance, or the improvement of firing conditions etc., basically elution It is impossible to eliminate In the safety standards defined by the standards for food additives based on the provisions of Article 10 Paragraph 1 of the Food Sanitation Law, the amount of lead eluted after being immersed in a 4% aqueous acetic acid solution for 24 hours is determined. However, in conventional upper paints for ceramics, even if the firing conditions are slightly changed, lead elution exceeding the safety standard may be observed.
Patent No. 1842054

  The present invention does not contain any lead component, and is excellent in durability against acid while having a dark color and beautiful gloss even with a thin layer equivalent to a conventional leaded ceramic upper paint, for use as a Western paint It is an object of the present invention to provide a suitable ceramic upper paint and a manufacturing method thereof.

  The upper paint for ceramics of the present invention contains silicon dioxide, aluminum oxide, boron oxide, alkali metal oxide, zinc oxide, at least one of lanthanum oxide or cerium oxide, and at least one of tungsten oxide or molybdenum oxide. It is characterized in that a pigment containing no lead or cadmium is mixed with the frit.

  The frit further contains at least one of an alkaline earth metal oxide and zirconium oxide.

  The pigment is characterized by being at least one of ferric oxide and antimony trioxide.

  The pigment is contained in the upper paint in an amount of 15 to 30% by mass.

  It is characterized in that it is dispersed in a dispersion medium to form a coating solution, which is applied and formed on a ceramic surface after drying to a film thickness of 50 μm to 250 μm.

  It is dispersed in a dispersion medium to form a coating liquid, which is dried and coated on a transfer paper to a film thickness of 50 μm to 250 μm to form a transfer paper for forming a ceramic upper paint.

  It is characterized by having a film thickness after firing of 20 μm to 200 μm on ceramics, which is a Western paint.

  The method for producing a ceramic top paint of the present invention comprises mixing at least one of silica, kaolin, boric acid, alkali metal carbonate, zinc oxide, lanthanum oxide or cerium oxide, at least one of tungsten oxide or molybdenum oxide, It is characterized by melting and aging at 1100 ° C. to 1300 ° C., rapidly cooling to form a frit, pulverizing, and then mixing a pigment not containing lead or cadmium.

  In the above production method, at least one of silica, kaolin, boric acid, alkali metal carbonate, zinc oxide, lanthanum oxide or cerium oxide, at least one of tungsten oxide or molybdenum oxide, an alkaline earth metal oxide, It is characterized in that after at least one kind of zirconium oxide is further mixed, it is melted and aged to form a frit.

  The upper paint for ceramics according to the present invention has a frit composition in which at least one kind of rare earth element, particularly lanthanum oxide or cerium oxide, and at least one kind of tungsten oxide or molybdenum oxide are allowed to coexist. Since the acid resistance of the upper paint can be prevented from deteriorating while being lowered, even if the thickness of the paint layer is 200 μm or less, an upper paint having a deep color and gloss can be obtained. Since the upper paint for ceramics of the present invention can be an upper paint comparable to conventional leaded and thin-layer ceramic upper paints, it can be used as a ceramic upper paint suitable for use as a Western paint.

The silicon dioxide component in the ceramic upper frit for ceramics of the present invention is formed using silica (Indian silica, Hinooka silica) and New Zealand kaolin which are natural raw materials. The alumina component is formed using aluminum hydroxide or New Zealand kaolin which is a natural raw material. New Zealand kaolin is composed of 51% by mass of silicon dioxide and 36% by mass of alumina, and other similar ones can be used as long as they contain as little impurities as possible. In addition, as an unavoidable component derived from natural raw materials such as silica and New Zealand kaolin, for example, Fe ₂ O ₃ or TiO ₂ may be contained in an amount of 0.5% by mass or less.

  Lanthanum oxide, cerium oxide and zinc oxide may be used in the form of an oxide or hydroxide. Boron oxide is derived from boric acid, alkali metal oxides and alkaline earth metal oxides are derived from carbonates, and zirconium oxide is derived from zirconium silicate. As long as it has the form of

The preparation purpose, raw material form, and usage ratio of each component in the present invention will be described.
Silicon dioxide, which is the main component in the ceramic frit for ceramics according to the present invention, may be contained so as to be 30 to 60% by mass in terms of oxide-based frit composition. The content is preferably 35 to 55% by mass, and more preferably 40 to 50% by mass. If it is less than 30% by mass, the chemical durability deteriorates, and if it exceeds 60% by mass, the melting temperature is too high.

  Alumina is used for modifying the silicon dioxide skeleton when forming the frit. By using kaolin or aluminum hydroxide, the reactivity in forming the frit can be improved. Alumina is preferably contained so as to be 3 to 6% by mass in terms of oxide-based frit composition. The content is preferably 3.5 to 5.5% by mass, and more preferably 4 to 5% by mass. If it is less than 3% by mass, the chemical durability deteriorates, and if it exceeds 6% by mass, the melting temperature becomes high, and the frit becomes devitrified.

  Boron oxide is contained for the purpose of lowering the melting temperature of the frit. The frit composition contains 15 to 25% by mass, preferably 18 to 22% by mass, and more preferably 18 to 21% by mass. Good. If it is less than 15% by mass, the effect of lowering the melting temperature is small, and if it exceeds 25% by mass, the chemical durability deteriorates.

  The alkali metal oxide may be one or more added in the form of carbonate and may be in the form of an oxide upon firing, and is contained for the purpose of lowering the melting point. It is good to contain so that it may become ~ 15 mass%. The content is preferably 7 to 13% by mass, and more preferably 9 to 12% by mass. If it is less than 5% by weight, the effect of lowering the melting temperature is small, and if it exceeds 15% by weight, the chemical durability deteriorates.

  Zinc oxide is added in the form of an oxide, and is contained for the purpose of imparting a melting point reduction and chemical stability. The content is preferably 5 to 13% by mass, and more preferably 6 to 12% by mass. If the amount is less than 4% by mass, the effect of lowering the melting temperature is small, and if it exceeds 15% by mass, the chemical durability deteriorates.

  Lanthanum oxide and cerium oxide can be added in the form of oxide or hydroxide, and any other oxide can be formed by firing to improve the chemical durability of the upper paint. The total frit composition is 0.1 to 3% by mass, preferably 0.3 to 2.5% by mass, and more preferably 0.5 to 2% by mass. Good. If it is less than 0.1% by mass, the effect of improving the chemical durability is small, and if it exceeds 3% by mass, the melting temperature becomes too high, the melting becomes insufficient, and the frit is devitrified.

  The upper paint for ceramics of the present invention further contains one or two of tungsten oxide and molybdenum oxide in each of the above components. These oxides are contained for the purpose of increasing the resistance to acid and increasing the glossiness of the paint while lowering the melting temperature, and are used in the form of an oxide, with a frit composition of 0.5 to 15% by mass, Preferably it is 1-12 mass%, It is good to contain so that it may become 3-10 weight% more preferably. If it is less than 0.5% by mass, these effects are small, and if it exceeds 15% by mass, the frit becomes crystalline, and the frit itself becomes devitrified.

  Although the basic composition of the thin-layer upper paint for ceramics of the present invention has been described, the following additives can be contained as optional components. That is, in order to provide chemical stability, zirconium oxide may be contained, and the content thereof is 0 to 10% by mass in the frit composition. If included, the total frit is preferably 0.5 to 8% by mass.

  Further, an alkaline earth metal oxide such as barium oxide or calcium oxide may be contained to give gloss to the upper paint for ceramics, and the content thereof is 0 to 1% by mass in the frit composition. If included, the content may be 0.1 to 0.8% by mass, and more preferably 0.2 to 0.6% by mass.

  Examples of the pigment used in the ceramic thin-layer upper paint of the present invention include metal oxide pigments, spinel pigments, zircon pigments, and the like that exhibit various colors, but are pigments that do not contain lead or cadmium. Lead, cadmium, and the like are harmful metal components pointed out in the Food Sanitation Law, and pigments that do not have these harmful metal components as constituent metals may be used as pigments. Further, ferric oxide and antimony trioxide can be added to form iron red pigments for ceramics.

  The upper paint for ceramics of the present invention has a pigment content of 15 to 30% by mass, preferably 15 to 25% by mass, more preferably 20 to 25% by mass, and can be an upper paint for ceramics suitable as a Western paint. .

  Next, the manufacturing process of the ceramic thin-layer upper paint according to the present invention will be described.

  Natural raw materials such as silica and kaolin are mixed with raw materials such as carbonates and oxides, and the resulting mixture is heated in a refractory crucible for frit melting at a temperature of 1100 ° C to 1350 ° C, preferably 1200 ° C to 1300 ° C for about 2 hours. After being melted and aged, it is rapidly cooled by dropping it into water, and it is pulverized into fine particles having an average particle diameter of several μm to make a thin frit for ceramics. And a pigment is mixed with the obtained frit, and it is set as the ceramic layer top paint of this invention.

  The upper paint for ceramics of the present invention may be dispersed and mixed in a dispersion medium such as water or oil, for example, acrylic oil, to form an application paint, and applied on the glaze layer formed on the ceramic.

  Also, after the ceramic upper paint of the present invention is dispersed and mixed in a dispersion medium such as acrylic oil to form an application paint, it is printed on a transfer paper to form a ceramic upper paint layer, The obtained transfer paper may be stuck on the glaze layer formed on the ceramic from the upper paint layer side for the ceramic, so that the upper paint for the ceramic is formed on the ceramic surface.

  The ceramic top paint of the present invention may be formed as a Western paint, for example, on a glaze layer with a film thickness of 50 μm to 250 μm after drying, preferably 50 μm to 200 μm, more preferably 50 μm to 150 μm. And the upper paint layer thickness for ceramics on the transfer paper.

  After the ceramic upper paint layer is formed, it may be fired at 700 ° C. to 900 ° C., preferably 750 ° C. to 850 ° C., but the ceramic upper paint of the present invention has a film thickness after firing of 20 μm to 200 μm, The film thickness is preferably 30 μm to 150 μm, more preferably 50 μm to 100 μm, and a film thickness suitable for Western paint can be obtained.

  The ceramic upper paint of the present invention can be a beautiful colored and glossy paint even when the thickness of the fired paint layer is 200 μm or less, and a conventional leaded ceramic upper paint was used. It can be comparable to a thin upper paint layer.

The upper paint for ceramics of the present invention has a coefficient of thermal expansion of 7.0 × 10 ⁻⁶ to 8.5 × 10 ⁻⁶ / ° C. (30 to 400 ° C.), which is 6.0 of the conventional leaded material. × 10 ^-6 ~ 16. no means inferior compared 0 × 10 ^-6 / ℃ and (30 to 400 ° C.). Moreover, a glass softening point is also 500 degreeC-600 degreeC, and is almost the same as 500 degreeC-600 degreeC of the conventional leaded material. Also, the firing temperature range with good color developability of the pigment is 700 ° C to 900 ° C, which is almost the same as 700 ° C to 900 ° C of the conventional leaded material.

  Furthermore, the upper paint for ceramics of the present invention has no change in appearance such as cloudiness even when immersed in a 4% aqueous acetic acid solution for 1 day as an acid resistance test, and lead and cadmium are not detected at all.

EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, the evaluation method described in the following Example is as follows.
(Acid resistance test)
As for acid resistance, even when immersed in a 4% aqueous acetic acid solution for 1 day, there was no change in cloudiness and the like on the appearance, and lead and cadmium were not detected at all.
(Glossiness)
The glossiness of the surface of the ceramic upper paint after firing was measured using “Glossmeter VG-2000” manufactured by Nippon Denshoku Industries Co., Ltd.
(Coefficient of thermal expansion)
The coefficient of thermal expansion was obtained by melting the upper paint for ceramics into a button-like lump, cutting it into a prismatic shape of about 5 x 5 x 20 (mm), making it a measurement sample, and using "TMA4000" manufactured by Mac Science Co., Ltd. The coefficient of thermal expansion in the temperature range of 30 to 400 ° C. was measured.
(Glass softening point)
The glass softening point is obtained by melting the upper paint for ceramics into a button-like lump, cutting it into a prismatic shape of about 5 x 5 x 20 (mm), and using it as a measurement sample, using "TMA4000" manufactured by Mac Science Co., Ltd. Measured.

(Example 1 to Example 6)
Hinooka silica and New Zealand kaolin are used as natural raw materials, and zirconium silicate (manufactured by Wako Pure Chemical Industries, Ltd.), boric acid (same), barium carbonate (same), calcium carbonate (same), When firing sodium carbonate (same product), potassium carbonate (same product), zinc oxide (same product), lanthanum oxide (same product), and tungsten oxide (same product), the composition ratios shown in Table 1 below are obtained. Added and mixed to a uniform batch of 200 g.

  Next, the mixture is transferred to a frit melting crucible, melted and aged at 1250 ° C. for 1 hour in a melting furnace having a silicon knit heating element of 20 kw, then the melt is dropped into water, rapidly cooled, and then 10 μm to The frit powder was pulverized to about 500 μm.

For 100 g of the obtained frit powder,
(1) When a mixture of 25 g of ferric oxide and 0.5 g of antimony trioxide is added and mixed and pulverized in an automatic mortar and pulverized to an average particle size of about 3 μm to 5 μm,
(2) When 30 g of a pigment (pigment number YW520) manufactured by Kawamura Chemical Co., Ltd. is added and ground in the same manner,
(3) When 20 g of chromium oxide (manufactured by Wako Pure Chemical Industries, Ltd.) is added and ground in the same manner,
(4) When 20 g of a pigment (pigment number MD300) manufactured by Kawamura Chemical Co., Ltd. is added and ground similarly,
Each ceramic upper paint was prepared.

  100 g of each of these upper paints is dispersed and mixed in 100 g of acrylic oil (manufactured by Kyoyo Chemical Industry Co., Ltd.) to form a paint by printing on a 4 × 4 cm square transfer paper with a dry thickness of 50 μm. did.

The resulting transfer sheet was stuck onto the glaze layer of ceramic respectively, firing the result at 800 ° C., the upper paint layer is 80 [mu] m, the reddish color ones of (1) above, those of (2) is Yellow, (3) was green, and (4) was blue.

  Table 1 below shows the frit composition for ceramics for upper paint (based on oxide), the glass softening point, the thermal expansion coefficient, the glossiness after firing of the ceramic upper paint of (1), and its acid resistance. The result about the external appearance finding about the paint surface state after a test is shown.

(Example 7 to Example 12)
Examples 1 to 6 were prepared so as to have the compositions shown in Table 2 except that cerium oxide (manufactured by Wako Pure Chemical Industries, Ltd.) was added instead of lanthanum oxide in the frit (oxide composition) in Examples 1 to 6. 1 to Example 6 A thin layer upper paint for ceramics was prepared.

  When a transfer paper was prepared in the same manner as in Examples 1 to 6 and an upper paint layer was formed in the same manner, (1) was red, (2) was yellow, and (3) was The green ones (4) developed a beautiful blue color.

  Table 2 below shows the frit composition for ceramic upper paint (oxide standard), the glass softening point, the coefficient of thermal expansion, the gloss after firing of the ceramic upper paint of (1), and its acid resistance. The result about the external appearance finding about the paint surface state after a test is shown.

(Example 13 to Example 18)
Except for adding molybdenum oxide (manufactured by Wako Pure Chemical Industries, Ltd.) instead of tungsten oxide in the frit (oxide composition) in Examples 1 to 6, Examples 1 to In the same manner as in Example 6, a ceramic thin layer upper paint was prepared.

  When a transfer paper was prepared in the same manner as in Examples 1 to 6 and an upper paint layer was formed in the same manner, (1) was red, (2) was yellow, and (3) was The green ones (4) developed a beautiful blue color.

  Table 3 below shows the frit composition for ceramic upper paint (based on oxide), the glass softening point, the thermal expansion coefficient, the glossiness after firing of the ceramic upper paint of (1), and its acid resistance. The result about the external appearance finding about the paint surface state after a test is shown.

(Example 19 to Example 24)
Except for adding cerium oxide (manufactured by Wako Pure Chemical Industries, Ltd.) instead of lanthanum oxide in the frit (oxide composition) in Examples 13-18, Examples 1- In the same manner as in Example 6, a thin ceramic upper layer paint was prepared.

  When a transfer paper was prepared in the same manner as in Examples 1 to 6 and an upper paint layer was formed in the same manner, (1) was red, (2) was yellow, and (3) was The green ones (4) developed a beautiful blue color.

  Table 4 below shows the frit composition for oxides for ceramics (based on oxide), the glass softening point, the coefficient of thermal expansion, the glossiness after firing of the ceramics for ceramics described in (1) above, and the acid resistance thereof. The result about the external appearance finding about the paint surface state after a test is shown.

Claims (9)

Lead and cadmium are contained in a frit containing at least one of silicon dioxide, aluminum oxide, boron oxide, alkali metal oxide, zinc oxide, lanthanum oxide or cerium oxide, and at least one of tungsten oxide or molybdenum oxide. A top paint for ceramics, characterized by mixing non-pertaining pigments. The ceramic upper paint according to claim 1, wherein the frit further contains at least one of an alkaline earth metal oxide and zirconium oxide. 3. The ceramic upper paint according to claim 1, wherein the pigment is at least one of ferric oxide and antimony trioxide. 4. The ceramic upper paint according to claim 1, wherein the pigment is contained in an amount of 15 to 30% by mass in the upper paint. The ceramic according to any one of claims 1 to 4, wherein the ceramic is dispersed in a dispersion medium to form a coating liquid, and is formed on the surface of the ceramic by coating to a film thickness of 50 µm to 250 µm after drying. Top paint. 2. A coating liquid dispersed in a dispersion medium, dried and coated on a transfer paper to a film thickness of 50 μm to 250 μm, and used as a transfer paper for forming an upper paint for ceramics. The upper paint for ceramics according to any one of claims 1 to 4. 7. The ceramic upper paint according to claim 5, wherein the ceramic has a post-baking film thickness of 20 to 200 [mu] m and is a Western paint. After mixing at least one of quartzite, kaolin, boric acid, alkali metal carbonate, zinc oxide, lanthanum oxide or cerium oxide, at least one of tungsten oxide or molybdenum oxide, melting and aging at 1100 ° C to 1300 ° C, A method for producing an upper paint for ceramics, comprising rapidly cooling to form a frit, pulverizing, and then mixing a pigment not containing lead or cadmium. At least one of quartzite, kaolin, boric acid, alkali metal carbonate, zinc oxide, lanthanum oxide or cerium oxide, at least one of tungsten oxide or molybdenum oxide, at least one of alkaline earth metal oxide, zirconium oxide 9. The method for producing a ceramic upper paint according to claim 8, wherein the mixture is further mixed and then melted and aged to form a frit.