JPH07100638B2 - Color pigment for ceramics and method for producing the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coloring pigment added to a glaze for coloring ceramics such as sanitary ware, interior and exterior tiles, tableware, etc., and a method for producing the same.

[0002]

A glaze for coloring ceramics (hereinafter referred to as a colored glaze) is prepared by mixing a basic glaze and a coloring pigment. Conventionally, as this preparation method, after adding water to the raw material of the color pigment to form a pigment slurry by wet-milling with a ball mill, a method of stirring and mixing in a tank together with the basic glaze slurry, or a raw glaze slurry of the color pigment raw material The method of crushing with a ball mill after mixing with the method was used, and the colored glaze obtained by these methods was used as a glaze for coloring ceramics.

[0003]

The conventional preparation of colored glaze is as follows.
Since the colored pigment is wet-milled with a ball mill, preparation takes time, and it is necessary to prepare a ball mill for each type of color glaze, which is troublesome. In addition, when changing the color for coloring the ceramics, it is necessary to clean the ball mill containing the colored glaze, which is troublesome, and the treatment of cleaning wastewater is also a problem. Further, in order to avoid this problem, there was also the idea of mixing the colored pigment with the basic glaze slurry as a powder without crushing it with a ball mill, but the colored pigment has large cohesiveness because it is fine particles, and when contacted with water. However, there is a fatal defect that the dispersibility is poor because the particles exclude water from each other to form lumps, which has not been put into practical use.

[0004]

The present invention is intended to solve the above problems and provides a colored pigment for ceramics which has good dispersibility even when added to a basic glaze as a powder, and a method for producing the same. It is a thing. That is, the color pigment for ceramics of the present invention is a compound of a transition element such as Fe, Co, Zr or the like, or a compound oxide color pigment fine particles obtained by mixing and firing a compound of another element with the compound, an inorganic electrolyte and an inorganic electrolyte. And at least one of a water-soluble polymer or an anionic surfactant is retained, and it is produced by the following two methods. One is to pulverize a pigment slurry formed by mixing the colored pigment fine particles and water by a wet pulverization method, then mix and dissolve an inorganic electrolyte in the pigment slurry, and then an anionic surfactant and / or After adding a water-soluble polymer, there is a method of evaporating water and pulverizing. Another is to divide the pigment slurry into fine pieces by a wet pulverizing method and then mix and dissolve an inorganic electrolyte to evaporate the water to color. To the pigment powder, anionic surfactant and or water-soluble polymer is added and mixed and pulverized,
It is a method of aging.

The inorganic electrolyte used in the present invention is preferably an ammonium salt such as ammonium chloride, ammonium nitrate or ammonium sulfate or an alkali metal salt such as sodium chloride, sodium nitrate, potassium chloride or potassium nitrate, or a mixture thereof. It is appropriately selected depending on the strength of the surface charge of the color pigment. The amount of the inorganic electrolyte mixed and dissolved in the pigment slurry is preferably up to 5 parts by weight based on the solid content of the colored pigment fine particles. The anionic surfactant contained in the color pigment fine particles together with the inorganic electrolyte needs to be a sulfate ester salt or a sulfonate salt, and one having a high anionization degree is preferable. As the water-soluble polymer, cellulosics such as MC, HEC, HPC, PVA, polyacrylic acid salt, and polyethylene oxide are preferable, and polyethylene oxide is particularly preferable because of its high dispersion effect. Further, among them, those having a molecular weight of about 100,000 to 2,000,000 are excellent in dispersibility and are suitable for the present invention. The content of the anionic surfactant and the water-soluble polymer in the color pigment fine particles is preferably 0.1 to 50% of the solid content of the color pigment, both in total.
It is particularly preferably 0.1 to 10%.

[0006]

By the production method of the present invention, the inorganic electrolyte, the anionic surfactant, and the water-soluble polymer are firmly held on the surface or inside of the colored pigment fine particles. The anionic surfactant or water-soluble polymer retained on the color pigment fine particles is
When the colored fine particles are added to the basic glaze slurry, they absorb the surrounding water and swell, and gradually dissolve in water to promote the dispersion of the colored pigment particles in water. The anionic surfactant neutralizes the adsorption of one molecule and is charged to (-) in the adsorption of two molecules to repel and disperse the fine particles of the coloring pigment. When the water-soluble polymer is contained in the coloring pigment fine particles,
A large number of hydrogen-bonding groups such as OH, CO, and NH ₃ of the water-soluble polymer are well adsorbed on the surface of the fine particles, and the repulsion between the adsorbed molecules accelerates the dispersion effect. Further, the retained inorganic electrolyte is first dissolved when added to the basic glaze slurry, exerts an ion antagonistic action between the released ions and the colored fine particles having a dispersant group, and dispersibility immediately after addition is maintained. increase. Due to the synergistic effect of the above respective actions, the coloring pigment for ceramics of the present invention can be easily dispersed in the basic glaze slurry simply by adding it.

[0007]

EXAMPLES The present invention will be described in detail below with reference to examples. Example 1 1 part after mixing 50 parts of cobalt oxide and 50 parts of silicon dioxide
A lump of the colored pigment obtained by firing at 300 ° C. for 4 hours was wet pulverized with a ball mill for 30 hours, then soluble components were removed, and a pigment slurry in which fine particles of the colored pigment and water were mixed was produced. Transfer this pigment slurry to a tank with a stirrer,
Two parts each of calcium chloride and sodium polyacrylate were added to the solid content of the color pigment and stirred. The pigment slurry after stirring was transferred to a stainless steel container and dried at 120 ° C., 2 parts of polyethylene oxide was added, and dry pulverization was performed to obtain a colored pigment of Example 1. On the other hand, the basic glaze was prepared by grinding 75 parts of frit, 12 parts of feldspar, 10 parts of silica stone, 5 parts of limestone, 5 parts of zinc white, 12 parts of zircon and 6 parts of clay together with 80 parts of water for 6 hours. As a result, a basic glaze slurry having a solid concentration of about 650 g / liter, a specific gravity of 1.4 and a pH of about 9.0, which is weakly alkaline, and contains 80% or more of particles having a solid content of 0.5 to 15 microns is obtained. The obtained basic glaze slurry,
Immediately after starting the stirring at a rotating glaze preparation tank with a stirrer at a rotation speed of 150 rpm, add 3 parts of color pigment to the solid content of the basic glaze, and continue stirring for 60 minutes to produce a colored glaze slurry. did. Then, this colored glaze slurry was spray-glazed on a tile plate and baked at 1100 ° C. to obtain a colored tile (1).

Example 2 A coloring pigment obtained by mixing 60 parts of zirconium oxide, 35 parts of silicon dioxide, 5 parts of praseodymium oxide, 20 parts of sodium chloride and 5 parts of sodium fluoride and then calcining at 1100 ° C. for 4 hours. The lump was wet-milled for 10 hours with a ball mill, and then soluble components were removed to produce a pigment slurry.
To this pigment slurry, add 3 parts of ammonium sulfate,
The mixture was stirred and dried at 120 ° C. 5 parts of HPC (hydroxypropyl cellulose) was added to the dried color pigment powder, and the mixture was pulverized with a high-speed pulverizer and then aged in steam to obtain a color pigment (2). On the other hand, the basic glaze is
Frit 50 parts, feldspar 12 parts, silica stone 10 parts, limestone 5
Parts, 5 parts of zinc white, 12 parts of zircon, and 6 parts of clay were pulverized together with water to prepare. After adding 3 parts of the coloring pigment (2) to the solid content of the basic glaze, the resulting basic glaze slurry was continuously stirred for 60 minutes to produce a colored glaze slurry.
Then, this colored glaze slurry was applied to a tile plate by spraying, and this was baked at 1100 ° C. to obtain a colored tile (2).

Example 3 Obtained by mixing 60 parts of zirconium oxide, 30 parts of silicon dioxide, 10 parts of ferric oxide, 5 parts of potassium nitrate, 10 parts of sodium fluoride and sodium sulfate, and calcining at 950 ° C. for 4 hours. The colored lump was wet pulverized with a ball mill for 10 hours, and then soluble components were removed to obtain a colored pigment slurry. To the obtained colored pigment slurry, 2 parts of calcium chloride and 1 part of polyethylene oxide were added to the solid content of the pigment and dried. Add H to the dried coloring pigment powder.
After 1 part of EC (hydroxyethyl cellulose) was added and pulverized, it was aged with steam to obtain a colored pigment (3). On the other hand, the basic glaze is frit 50 parts, feldspar 12 parts, silica stone 10
Part, limestone 5 parts, zinc white 5 parts, zircon 12 parts, clay 6
Part was crushed with water to prepare. After adding 3 parts of the coloring pigment (3) to the solid content of the basic glaze, the resulting basic glaze slurry was continuously stirred for 60 minutes to produce a colored glaze slurry. Then, this colored glaze slurry was applied to a tile plate by spraying, and this was baked at 1080 ° C. to obtain a colored tile (3).

Comparative Example 1 After mixing 50 parts of cobalt oxide and 50 parts of silicon dioxide,
The lump of the colored pigment obtained by firing at 1300 ° C. for 4 hours and the same basic glaze as in Example 1 were put together in a ball mill and wet-ground with water as a medium to obtain a colored glaze slurry. The tile slurry is glazed with the obtained colored glaze slurry and 1
It baked at 100 degreeC and the colored tile (a) was obtained. this,
When compared with the colored tile (1), no difference was observed in the dispersed state of the pigment particles. In addition, the spectral reflectance of the colored portion of the colored tile (1) and the colored tile (a) was measured, and CIE19
As a result of calculating the color difference using the 76-color-difference calculation formula, the value was 0.09, and it was confirmed that there was almost no difference in the colors of both tiles. For reference, FIG. 1 shows a color control chart when the spectral reflectance of the colored tile (a) is used as a standard value.

Comparative Example 2 A mass of colored pigment obtained by mixing 60 parts of zirconium oxide, 35 parts of silicon dioxide, 5 parts of praseodymium oxide, 20 parts of sodium chloride and 5 parts of sodium fluoride and then calcining at 1100 ° C. for 4 hours. Together with the same basic glaze as in Example 1,
It was put in a ball mill and wet-ground with water as a medium to obtain a colored glaze slurry. The obtained colored glaze slurry was spray-glazed on a tile plate and baked at 1100 ° C. to obtain a colored tile (b). When this was compared with the colored tile (2), no difference was observed in the dispersed state of the pigment particles. Moreover, the spectral reflectance of the colored part of the colored tile (2) and the colored tile (b) was measured, and the color difference was calculated by the CIE1976 color difference calculation formula. As a result, the value was 0.28. It was confirmed that there was no. For reference, FIG. 2 shows a color control chart when the spectral reflectance of the colored tile (b) is set to a standard value.

Comparative Example 3 Obtained by mixing 60 parts of zirconium oxide, 30 parts of silicon dioxide, 10 parts of ferric oxide, 5 parts of potassium nitrate, sodium fluoride and 10 parts of sodium sulfate, and then firing at 950 ° C. for 4 hours. The lump of color pigment and the same basic glaze as in Example 1 were put together in a ball mill and wet-ground with water as a medium to obtain a colored glaze slurry. The obtained colored glaze slurry was spray-glazed on a tile plate, and this was baked at 1080 ° C. to obtain a colored tile (c). When this was compared with the colored tile (3), no difference was observed in the dispersed state of the pigment particles. Moreover, the spectral reflectance of the colored part of the colored tile (3) and the colored tile (c) was measured, and the color difference was calculated by the CIE1976 color difference calculation formula. As a result, the value was 0.39. It was confirmed that there was no. Figure 3 for reference
Figure 3 shows the color control chart when the spectral reflectance of the colored tile (c) is used as the standard value.

[0013]

EFFECT OF THE INVENTION If the coloring pigment for ceramics of the present invention is used,
It was confirmed that even if powder was added as it was to the basic glaze slurry, it could be uniformly dispersed in a short time. This effect saves the labor of wet pulverizing the color pigment and the mixture of the basic glaze and the basic glaze with a ball mill, is not only efficient, but also reduces the yield of the colored glaze when using the ball mill, and the cost required for cleaning the ball mill. , All problems such as wastewater treatment are solved. Further, the color pigment of the present invention and the method for producing the same can be used for various things such as sanitary ware, inner and outer layer tiles, tableware, etc., and its effect should be highly evaluated.

[Brief description of drawings]

FIG. 1 shows the spectral reflectance of the colored tile (a) as a standard value,
Color control chart plotting the spectral reflectance of the colored tile (1). (In the figure, × is the spectral reflectance of the colored tile (a), ◯ is the spectral reflectance of the colored tile (1), ΔL * is the brightness difference, Δa * and Δb * are the saturation differences, and N is the equal hue. The line is shown.)

[FIG. 2] Using the spectral reflectance of the colored tile (b) as a standard value,
Color control chart plotting the spectral reflectance of colored tile (2). (In the figure, × is the spectral reflectance of the colored tile (b), ◯ is the spectral reflectance of the colored tile (2), ΔL * is the brightness difference, Δa * and Δb * are the saturation differences, and N is the equal hue. The line is shown.)

[FIG. 3] Using the spectral reflectance of the colored tile (c) as a standard value,
Color control chart plotting the spectral reflectance of colored tile (3). (In the figure, × is the spectral reflectance of the colored tile (c), ◯ is the spectral reflectance of the colored tile (3), ΔL * is the lightness difference, Δa * and Δb * are the saturation differences, and N is the equal hue. The line is shown.)

Claims (3)

[Claims] 1. A compound of a transition element such as Fe, Co, Zr or the like, or a colored pigment fine particle of a composite oxide obtained by mixing a compound of this element with a compound of another element, and firing the mixture, an inorganic electrolyte and a water-soluble polymer or anion. Colored pigment for ceramics, characterized in that it retains at least one of the organic surfactants. 2. A pigment slurry obtained by mixing the colored pigment fine particles and water is pulverized by a wet pulverization method, and then an inorganic electrolyte is mixed and dissolved in the pigment slurry, and then an anionic surfactant and Alternatively, after adding a water-soluble polymer, water is evaporated and pulverized, and the color pigment fine particles are mixed with an inorganic electrolyte,
A method for producing a colored pigment for ceramics, wherein at least one of a water-soluble polymer and an anionic surfactant is retained. 3. The pigment slurry is pulverized by a wet pulverization method, and then a pigment powder obtained by mixing and dissolving an inorganic electrolyte and evaporating water is added with a water-soluble polymer and / or an anionic surfactant and mixed and pulverized. Then, the color pigment fine particles are aged to retain the inorganic electrolyte and at least one of a water-soluble polymer and an anionic surfactant in the method for producing a color pigment for ceramics.