JPH06256011A - Inorganic pigment composition and its production - Google Patents

Abstract

PURPOSE:To obtain an inorganic pigment composition having low expansion and stability at high temperature by blending prescribed components to prepare a given composition and burn ing. CONSTITUTION:Prescribed components are blended to give a chemical composition consisting essentially of cordierite of the formula ((x) and (y) are 0.03<=x<=0.50, 0.03<=y<=0.50; M' is one or more selected from Cu, Co, Ni and Mn; M'' is one or more selected from Fe and Cr) to give a blend. Then the blend is mixed, heated and melted at >=1,200 deg.C and quenched to give glass. Then the glass is ground, cordierite is crystallized at >=800 deg.C to produce an inorganic pigment composition having about 23X10<-7>/ deg.C coefficient of thermal expansion.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inorganic pigment composition used for coloring glass, ceramics and the like and a method for producing the same.

[0002]

2. Description of the Related Art Coloring a part or all of glass, ceramics or the like has been conventionally performed. For example, a low-melting-point glass frit base containing a pigment of a certain color may be applied and baked on a transparent glass surface for the purpose of designing, shielding, or the like to form a colored layer, thereby coloring the glass. The pigment used here had a crystal structure such as spinel and had a large coefficient of thermal expansion.

[0003]

Since the pigments used conventionally have large thermal expansion, the coefficient of thermal expansion of the colored layer tends to be larger than that of glass. Therefore, there is a problem that tensile stress acts on the glass and the strength of the glass decreases. On the other hand, cordierite has a chemical formula of 2MgO.2Al ₂ O ₃ .5SiO ₂ and is known as a ceramic material having low thermal expansion. However, the powder had a white color, and as it was, it was difficult to use it as an inorganic pigment other than white.

An object of the present invention is to solve the above problems of the prior art and to provide an inorganic pigment composition having a low thermal expansion and stable at high temperature, and a method for producing the same.

[0005]

The present invention is mainly composed of cordierite and is composed of 2 (Mg _1-x · M ′ _x ) O · 2 (A
When expressed as l _{2 (1-y)} · M ″ _2y ) O ₃ / 5SiO ₂ ,
x and y are 0.03 ≦ x ≦ 0.50 and 0.03 ≦, respectively.
y ≦ 0.50 is satisfied, M ′ is at least one selected from Cu, Co, Ni and Mn, and M ″ is Fe.
And at least one inorganic pigment composition selected from Cr and a method for producing the same.

The present invention will be described in detail below.
First, in the chemical formula, 2 (Mg _1-x・ M ' _x ) O ・ 2 (Al
_{2 (1-y) · M} "2y) when expressed as O ₃ · 5SiO _2, M '
Is selected from Cu, Co, Ni, and Mn, and M ″ is selected from Fe and Cr, and mixing is performed. Here, M ′ and M ″ are 2, and 2, respectively.
Represents a trivalent metal ion and colors cordierite.
When x and y are smaller than 0.03, coloring is insufficient, and when larger than 0.50, compounds having a crystal structure other than cordierite increase, and thermal expansion becomes too large.

In the production of such an inorganic pigment composition, the prepared powders are mixed and then fired, and the added divalent and trivalent metal ions are partially solid-dissolved in Mg and Al sites, respectively. An inorganic pigment composition having a cordierite structure is obtained. In addition, the inorganic pigment composition having a cordierite structure can also be obtained by heat-treating again after mixing and vitrifying.

In the former manufacturing method, the firing temperature is 100.
Temperatures above 0 ° C are preferred. If the firing temperature is lower than 1000 ° C., the added divalent and trivalent metal ions do not sufficiently form a solid solution, resulting in insufficient coloring.

In the latter production method, although depending on the type and amount of the added divalent and trivalent metal ions, first, the mixture is heated and melted at a temperature of 1200 ° C. or higher and then rapidly cooled to form a cordierite glass. to make. Then, the glass is heated at a temperature of 800 ° C. or higher to crystallize the inorganic pigment composition having a cordierite structure. The glass may be crushed before the crystals are precipitated.

The raw materials M'and M "may be added in the form of a metal or in the form of a compound.

[0011]

In the present invention, it is considered that the originally white cordierite is colored by the solid solution of the added divalent and trivalent metal ions in the Mg and Al sites, respectively.

[0012]

【Example】

[Examples 1 to 9] 2 (Mg _1-x · M ′ _x O · 2 (Al
_{2 (1-y)} · M ″ _2y ) O ₃ · 5SiO ₂ was mixed and mixed in the proportions (unit: atomic ratio) shown in Table 1. After that, 1000 kg / cm in an outer diameter of 20 mm and a length of 30 mm.
Molded in ² and fired for 2 hours at the firing temperature (unit: ° C) shown in Table 1 to obtain a sintered body. After observing the color of the obtained sintered body with the naked eye, a sample having an outer diameter of 5 mm and a length of 15 mm was cut out, and the coefficient of thermal expansion from room temperature to 700 ° C. (unit: 10 ⁻⁷ /
C) was measured. The results are shown in Table 1. Table 1 also shows Comparative Examples 1 and 2. As is clear from Table 1,
The inorganic pigment composition according to the present invention has a small coefficient of thermal expansion,
It is colored black, blue, green, etc.

[0013]

[Table 1]

[Comparative Examples 1 and 2] Preparation, mixing and firing were carried out under the conditions shown in Table 1 and evaluated in the same manner as in Example 1. In Comparative Example 1, although the coefficient of thermal expansion was small, whitish coloring was not observed. Was enough. Comparative Example 2 was colored sufficiently black, but had a large coefficient of thermal expansion.

[Example 10] Cordierite powder 10
When Cu powder was added and mixed in a ratio of 0 g to 0 g, and the mixture was molded and fired in the same manner as in Example 1, it was colored black and had a thermal expansion coefficient of 23 × 10 ⁻⁷ / ° C.

[Example 11] The composition of Example 1 was prepared,
After mixing, the mixture was heated and melted at 1600 ° C., and rapidly cooled to vitrify. Then, it was kept at 1200 ° C. for 2 hours to carry out a crystallization treatment. As a result, it was colored black and had a coefficient of thermal expansion of 24 × 10 ^−7.
/ ° C.

[Embodiment 12] In Embodiment 11, after vitrification, it is crushed to have an outer diameter of 20 mm and a length of 30 mm of 1000 k.
Molded at g / cm ² . Then, crystallization treatment was performed in the same manner as in Example 11. As a result, it is colored black and has a coefficient of thermal expansion of 2
It was 3 × 10 ⁻⁷ / ° C.

[0018]

According to the present invention, an inorganic pigment composition having a low expansion and stable at high temperature can be obtained.

Claims (4)

[Claims] 1. Mainly composed of cordierite, 2 (Mg
_{1-x · M 'x)} O · 2 (Al 2 (1-y) · M "2y) O 3 · 5
When expressed as SiO ₂ , x and y are each 0.03 ≦ x
≦ 0.50, 0.03 ≦ y ≦ 0.50, and M ′ is at least one selected from Cu, Co, Ni, and Mn, and M ″ is at least one selected from Fe and Cr. An inorganic pigment composition. 2. The method for producing an inorganic pigment composition according to claim 1, wherein the chemical composition is adjusted to the above chemical composition, the mixture is mixed, and then the composition is baked at a temperature of 1000 ° C. or higher. 3. The composition is prepared to have the above chemical composition, and after mixing, heated and melted at a temperature of 1200 ° C. or higher and rapidly cooled to obtain glass, and cordierite is crystallized at a temperature of 800 ° C. or higher. The method for producing the inorganic pigment composition according to claim 1. 4. Mixing to have the above chemical composition, mixing, heating and melting at a temperature of 1200 ° C. or higher and quenching to obtain glass, and crushing cordierite at a temperature of 800 ° C. or higher after crushing. The method for producing the inorganic pigment composition according to claim 1, wherein