JP2001233636A - Glass ceramic with pearl-like muffle painting and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a glass ceramic with pearl-like muffle painting, capable of exhibiting pearl-like effects, and having the original strength possessed by the light-transmitting low expansion glass ceramic, and further to provide a method for producing the glass ceramic. SOLUTION: A pearl-like paint comprising a pearl-like material obtained by coating an inorganic pigment with zirconium oxide, or a compound composed of titanium oxide and the zirconium oxide, and a silicone resin or a siliceous sol is painted on a light-transmitting low expansion glass ceramic, and the painted glass is fired to provide the objective glass ceramic with the pearl-like muffle painting. A light-shading layer is preferably laminated thereon after forming the pearl-like paint layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a glass ceramic with a pearl pattern used for a top plate of a cooking device and a method for producing the glass ceramic.

[0002]

2. Description of the Related Art Glass ceramics (crystallized glass)
Is a polycrystalline material that is crystallized by reheating raw glass with a special composition. Glass ceramics mainly have five main crystal phases: β-quartz solid solution, β-spodumene solid solution, β-wollastonite, mica crystal, and cordierite. Among these, glass ceramics that precipitate β-quartz solid solution and β-spodumene solid solution have a coefficient of thermal expansion of 10 × 10 ⁻⁷ / ° C. or less and are referred to as low expansion glass ceramics.

Further, in a low expansion glass ceramic which precipitates a β-quartz solid solution, the β-quartz solid solution exhibits a negative expansion characteristic, and cancels out the positive expansion characteristic of the remaining glass layer, so that the expansion coefficient becomes almost zero. . The size of the precipitated crystal of the β-quartz solid solution is 0.1 μm or less, smaller than the wavelength of visible light, and the crystal phase and the remaining glass layer have almost the same refractive index, so that there is no light scattering, It is transparent in nature and transmits light in the visible to infrared regions well. Such β-
Glass ceramics that precipitate a quartz solid solution are called translucent low expansion glass ceramics. When applying a decorative decoration to such a translucent low-expansion glass ceramic, the thermal expansion coefficient of the ceramic paint is 50 to 80 × 10 ⁻⁷ , even if the ceramic paint used for applying the decorative decoration to ordinary glass is used. /
° C and thermal expansion does not occur, so that a decorative layer cannot be formed. For this reason, various devices have been conventionally devised as a method of decorating a transparent low-expansion glass ceramic with a picture.

For example, Japanese Patent Application Laid-Open No. 62-27348 discloses a glass flux painting method in which a pigment obtained by adding a pigment to a glass flux is painted. As a raw material of the glass flux, a glass that precipitates β-eucryptite or β-spodumene having a softening temperature of about 1300 ° C. is used. In order to bring the apparent thermal expansion coefficient of the painted layer closer to that of glass ceramics, a large amount of aluminum titanate having a small thermal expansion coefficient is blended.

Japanese Patent Application Laid-Open No. 61-168586 discloses a method of forming a paint for coating containing a glass flux and a flux on the surface of a light-transmitting low-expansion dehydroceramic. Further, Japanese Patent Application Laid-Open No. 3-65532 discloses a raster painting method for painting with a raster.

[0006]

By the way, in order to obtain a pearl-like decorative effect, it is necessary that materials other than pearl-like pigments among the raw materials for painting become translucent after firing.
However, in the technique disclosed in Japanese Patent Application Laid-Open No. 27348/1987, the painted layer contains a large amount of aluminum titanate for reducing expansion. Since aluminum titanate has a low translucency, even if a pearl pigment is added to the painted layer, the pearl effect disappears.

Further, the strength of the painted layer is reduced unless aluminum titanate is blended in order to make the painted layer transparent. The reason is that the glass flux in the painted layer moves to the glass ceramics, and an intermediate layer having thermal expansion mismatches is formed on the surface of the glass ceramics, and the strength is deteriorated.

In the technique disclosed in Japanese Patent Application Laid-Open No. 61-168586, fine powder of dehydroceramic is an essential element of the translucent heat-insulating ceramic. The dehydroceramic fine powder hardly melts at a firing temperature (850 ° C.) at which the translucency of the translucent low-expansion glass ceramic is not impaired.

In the technique disclosed in Japanese Patent Application Laid-Open No. 3-65532, even if a pearl pigment is blended with the raster, the resin component in the raster is in a carbonized state during firing. It does not adhere well and the layer with pearl pattern is not formed. Even if the painted layer is formed, if the raster is a colored metal oxide, the pearl color effect cannot be obtained because the surface of the pearl pigment is covered with the metal oxide.

No other prior arts exhibit a sufficient pearl-like effect and suppress the strength deterioration.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a pearl-tone glass ceramic having a pearl-like effect, having the original strength of a light-transmitting low-expansion glass ceramic, and a method of manufacturing the same. .

[0012]

According to the first aspect of the present invention, there is provided a pearl material comprising an inorganic pigment coated with zirconium oxide or a mixture of titanium oxide and zirconium oxide, and a pearl material comprising a silicone resin or a siliceous sol. The present invention is a pearl-like glass ceramic having a pearl-like paint layer formed by applying a paint to a translucent low-expansion glass ceramic.

A pearl-colored glass ceramic having the original strength of a translucent low-expansion glass ceramic is obtained by painting a transparent low-expansion glass ceramic using a pearl paint containing the pearl-like material. Can be. The reason is considered as follows.

As shown in FIG. 3, the organic functional groups of the silicone resin or the siliceous sol contained in the pearlescent paint layer 6 are separated during firing, and the silanol groups (Si) on the surface of the translucent low-expansion glass ceramics are removed. -OH group),
A siloxane bond 10 is formed. The pearl material 2 included in the pearl color layer 6 has zirconium oxide 4 on the surface of the inorganic material 3. Since the zirconium oxide coating 4 has a very large surface area, it has high surface activity and high reactivity. As a result, the organic functional groups of the silicone resin or the siliceous sol are released during firing, and the zirconium oxide coating 4
Form a Si—O—Zr bond 1 on the surface of Si-O-
The Zr bond 1 is slightly sparser than the bond formed when the glass flux is melt-bonded, and therefore absorbs the difference in heat shrinkage between the translucent low-expansion glass ceramic 7 and the pearl material 2. Therefore, no crack occurs due to the difference in heat shrinkage between the translucent low-expansion glass ceramic 7 and the pearl color layer 6. Further, since there is no melting process as in the conventional glass flux method, deterioration of the glass strength due to component movement does not occur. Therefore, it is considered that a pearl-tone glass ceramic with high impact resistance and high thermal shock resistance can be obtained without deteriorating the original strength of the translucent low expansion glass ceramic.

The pearl-like material is obtained by coating an inorganic pigment with zirconium oxide or a mixture of zirconium oxide and titanium oxide. The inorganic pigment is not particularly limited,
Examples include kaolin, talc, sericite, pyroferrite, natural mica, synthetic mica, and aluminum oxide. The color of the inorganic pigment may be any color, and the pearlescent color layer has a pearly color added to the color.

A known technique can be used for coating the zirconium oxide. For example, when coating zirconium oxide on mica of an inorganic pigment, urea is added to dissolve the zirconium oxide in an aqueous solution whose pH has been adjusted to 2.7. Here, mica powder is suspended and about 9
Heat to 0 ° C. and maintain temperature for about 1.5 hours with good stirring. Thereafter, there is a method in which the slurry is filtered, washed with water, dried, and fired at a high temperature of 700 ° C to 1000 ° C.

As in the second aspect of the present invention, the content of the pearl material in the pearl color material is preferably 0.1 to 10% by weight in a coated state. At this time, it is preferable that the silicone resin or the siliceous sol is 5 to 20% by weight and the solvent is 70 to 94.9% by weight.
If the content of the pearl material is less than 0.1% by weight, the pearl effect may be reduced. 10% by weight
When the value exceeds, there is a possibility that the adhesion to the light-transmitting low-expansion glass ceramic is weakened due to too much pearl pigment.

The silicone resin or the siliceous sol is
It works as a bonding material for bonding between pearlescent material and translucent low expansion glass ceramics. Silicone resin refers to a polymer of an organosilicon compound having a siloxane bond as a main skeleton. For example, straight silicone varnish K
R271 (manufactured by Shin-Etsu Chemical), modified silicone varnish KR2
11 (manufactured by the company), silicone alkyd varnish (manufactured by the company), and silicone epoxy varnish ES100N (manufactured by the company). An organic solvent in which the silicone resin can be dissolved is used if necessary. If necessary, a resin which burns faster than the silicone resin and has compatibility can be used as a thickener. Siliceous sols are, for example,
A silica sol obtained by hydrolyzing ethyl silicate or the like, a colloidal silica sol, or the like can be used.

The content of the silicone resin or the siliceous sol in the pearl paint is 90 to 9%.
Preferably it is 9.9% by weight. If the content is less than 90% by weight, the amount of the pearl-like material is too large, and the adhesion to the light-transmitting low-expansion glass ceramic may be weak. 9
If the content exceeds 9.9% by weight, bubbles may be generated when the resin component is burned out during firing, which may adversely affect the painted layer, such as dusting, and may reduce the pearl-like effect.

The translucent low expansion glass ceramic is
There is no particular limitation as long as it is translucent and has a low expansion coefficient.
For example, there is one in which β-quartz solid solution is precipitated in the main crystal phase.

The crystallinity of the translucent low-expansion glass ceramic on which the β-quartz solid solution is precipitated is, for example, about 7 by volume.
0%, and the crystal size is 0.1 μm or less. The β-quartz solid solution exhibits a negative expansion characteristic, and cancels out the positive expansion characteristic of the remaining glass phase, so that the coefficient of thermal expansion becomes almost zero. The refractive index (nD) is 1.541, the size of the precipitated crystals of the β-quartz solid solution is 0.1 μm or less, smaller than the wavelength of visible light, and the refractive indices of the crystal phase and the residual glass phase are almost the same. Therefore, there is no scattering of light, the appearance is transparent, and light in the visible light range to the infrared range is well transmitted.

The pearlescent paint may be painted in one layer or two or more layers. Even in the case where a plurality of layers are stacked, firing of the pearl color paint may be performed only once. Pearl paints may be applied to the entire surface of translucent low expansion glass ceramics,
It may be printed in a desired pattern.

It is preferable that the light-shielding layer is formed by laminating after forming the pearl color layer as in the third aspect of the present invention. Thereby, when the pearl-colored glass ceramic is viewed from the side opposite to the pearl-color paint layer, the pearl-color of the pearl-color paint layer can be seen more effectively through the translucent low-expansion glass ceramic. Further, by making the color of the light-shielding layer similar to that of the layer with a pearl-like picture, an elegant pearl-like decorative effect can be obtained.

The light-shielding layer is formed by applying a light-shielding material to the pearl paint layer and baking it. The light-shielding material is
Use a material that becomes opaque after firing that can be used for translucent low expansion glass ceramics. As the light-shielding material, for example, a material obtained by forming a paste of aluminum titanate, a low-expansion glass flux, and an inorganic pigment with an organic binder can be used. As the inorganic pigment, those similar to the inorganic pigments in the pearl material or those for ceramics can be used. Also, a raster painting material can be used as the light-shielding material. A raster is a dilute solution of an organometallic compound.

The light-shielding layer may be sintered together with the pearl color layer, or may be separately sintered after sintering the pearl color layer.

According to a fourth aspect of the present invention, there is provided a pearl color material comprising an inorganic pigment coated with zirconium oxide or a mixture of titanium oxide and zirconium oxide, and a pearl color material comprising a silicone resin or a siliceous sol. A method for producing a pearl-painted glass ceramic, comprising a pearl paint layer formed by painting and firing a low expansion glass ceramic.

According to the present production method, as described above, it is possible to obtain a pearl-tone glass ceramic having a pearl tone and having the original strength of a translucent low expansion glass ceramic.

The above-mentioned glass ceramic with a pearl pattern is
For example, it can be used as a top plate for cookers such as an electromagnetic cooker and an electric heater. In this case, it is preferable that the pearl color layer is arranged on the back side of the top plate. This is for preventing the generation of scratches on the pearl paint layer during use of the cooker. It can also be used as a microwave oven turntable.

[0029]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1 A glass ceramic with a pearl pattern according to an embodiment of the present invention will be described with reference to FIG. As shown in FIG. 1, the glass ceramics 8 with a pearly tone of this example are composed of a translucent low-expansion glass ceramics 7 and a pearly color layer 6 formed on the back side thereof. As the translucent low-expansion glass ceramic 7, the main crystal phase precipitates a β-quartz solid solution, and the thermal expansion coefficient is 6.5 × 10 ⁻⁷ / ° C. (30 to 380).
° C) brand name “Neoceram N-0” (hereinafter “N-0”)
That. ) Was used.

The method for producing the glass ceramic with pearl-like picture of this embodiment will be described. Add 2.7 pH with urea
The zirconium oxide is dissolved in the aqueous solution adjusted to the above, and the mica powder is suspended therein, heated to about 90 ° C., and maintained at the temperature for about one and a half hours with good stirring. And dried, 700 ° C ~ 1000
It was fired at a high temperature of ° C. As a result, a pearl material obtained by coating mica with zirconium oxide was obtained.

5% by weight of a pearl material, 15% by weight of a silicone resin (containing 50% by weight of an organic solvent), 76% by weight of an organic solvent, and 4% by weight of a thickening resin are kneaded to form a paste. Was prepared. Next, as shown in FIG. 1, a pearlescent paint layer 6 was formed by printing a pearlescent paint on one surface of a translucent low expansion glass ceramic 7 (N-0) using stainless steel 250 mesh. This is 85
By firing at 0 ° C., the pearl color layer 6 was sintered to obtain a pearl-colored glass ceramic 8. The obtained pearl-tone glass ceramics 8 exhibited a pearl-tone effect.

Glass ceramic with pearl-like picture 8 of this example
Can be used as a top plate of an electromagnetic cooker. In this case, the pearl-painted glass ceramics 8 is arranged on the housing of the electromagnetic cooker such that the pearl paint layer 6 is arranged on the back side 82 thereof. Front side 8
1 is a surface on which a cooking container such as a pot or a frying pan is placed.
Looking at the glass ceramic with pearl tone from the front side 81, it appeared as a pearl ivory tone transparent plate.

Embodiment 2 The glass ceramic with pearlescent paint of this example used a pearlescent material obtained by coating an inorganic pigment with a mixture of titanium oxide and zirconium oxide. Others are the same as in Experimental Example 1. The obtained glass ceramics with pearl color had a pearl ivory effect and exhibited a pearl effect. The glass ceramic with a pearl-like picture of this example can be used as a top plate of an electromagnetic cooker as in Experimental Example 1.

Embodiment 3 As shown in FIG. 2, the glass ceramic with pearl color of this example is provided with a pearl color layer 6 on the first layer, a light-shielding layer 5 on the second layer, and these layers at the same time. This is an example of sintering.
As shown in FIG. 2, first, a pearlescent paint layer 6 was formed on one surface of a light-transmitting low-expansion glass ceramic as in the first embodiment.

Next, 45% by weight of aluminum titanate
10% by weight of Fe—Cr—Co black inorganic pigment and 45% by weight of low expansion glass flux
The mixture was kneaded using 0% by weight to prepare a paste-like light-shielding material. This was printed on the surface of the pearl paint layer 6 using a stainless steel 250 mesh to form the light-shielding layer 5. Next, the translucent low-expansion glass ceramics 7 on which the pearl color layer 6 and the light shielding layer 5 were formed was fired at 850 ° C., and the pearl color layer 6 and the light shielding layer 5 were simultaneously sintered. In this way, a glass ceramic 8 with a pearl-like picture was obtained. The obtained glass ceramics with pearl tone had a silver tone of pearl tone.

Glass ceramic with pearl-like picture 8 of this example
Can be used as a top plate of an electromagnetic cooker. In this case, the pearl color layer 6 and the light shielding layer 5 are arranged on the back side 82 of the glass ceramic 8 with pearl color,
The front side 81 is a surface on which a cooking container such as a pot or a frying pan is placed. In this case, since the light-shielding layer 5 was provided as the second layer, the pearl-like effect of the pearl-color paint layer 6 as the first layer was more effectively exhibited when viewed from the front side surface 81.

Embodiment 4 This embodiment is an example in which a pearlescent paint layer and a light-shielding layer are separately fired. First, a pearl-like paint was printed on one surface of a translucent low-expansion glass ceramic (N-0) in the same manner as in the first embodiment. Next, these were fired at 850 ° C. to form a pearlescent paint layer 6.

Next, using a 250 mesh stainless steel, a black raster paste LU1404 (trade name)
Was applied to the surface of the pearl color layer 6. These are 85
It was baked again at 0 ° C. to obtain a light shielding layer 5. From the above,
A pearl-like glass ceramic 8 having a pearl-like paint layer 6 and a light-shielding layer 5 provided on one surface of a translucent low-expansion glass ceramic 7 was obtained. The obtained glass ceramics with a pearl tone exhibited a silver tone of pearl tone.

Comparative Example 1 N-0 similar to that of Embodiment 1 was prepared. Stainless 2
Using 50 mesh, commercially available pearl paint for ceramics, N
-0 was printed on one side and baked at 850 ° C. to form a pearlescent paint layer. Next, the same light-shielding material as that of Embodiment 3 was applied to the surface of the pearlescent paint layer, and baked again at 850 ° C. to form a light-shielding layer. In this way, a pearly silver gray glass ceramic with a pearly picture was obtained.

(Experimental Examples) Embodiments 1-4 and Comparative Example 1
The impact test and the thermal shock test were performed on the pearl-painted glass ceramics. The pearl-coated glass ceramics to be subjected to the test were manufactured according to Embodiments 1 to 4 and Comparative Example 1. In addition, a test piece composed of only N-0 and having neither a pearl paint layer nor a light-shielding layer was formed.

Impact Test The impact test was performed assuming that a pot or the like fell on a top plate of a cooker when used. Embodiments 1 to 4 and Comparative Example 1 each having a thickness of 4 mm and a size of 40 cm × 55 cm square were prepared, and an N-0 plate was supported and fixed at four corners with a 2 cm square chip. In addition, the pearl color layer and the light-shielding layer were solid-coated on one entire surface of the N-0 plate and arranged on the lower side of the plate. The impact test method is to drop a 500 g steel ball on a plate. The drop height started from 5 cm and was increased every 5 cm to 40 cm. If you pass 40cm,
The strength has no practical problem. Table 1 shows the test results.

Thermal Shock Test The thermal shock test is based on the assumption that water is spilled on the heated top plate because the plate may be heated up to about 600 ° C. when used as a top plate of a cooker. went. Embodiments 1 to 4, Comparative Example 1 and a N-0 plate cut out to a thickness of 4 mm and a 10 cm square were prepared. The pearlescent paint layer and the light-shielding layer used were those in which the entire surface of the N-0 plate was solid-coated. In the thermal shock test method, a test in which a plate is heated in a furnace to 620 ° C. and dropped into water at 20 ° C. is repeated five times. The test results are shown in Table 2.

[0043]

[Table 1]

[0044]

[Table 2] Thermal shock test ΔT = 600 ℃

As can be seen from the above table, in the case of the first to fourth embodiments and the N-0 plate, the impact test was performed at 40 cm.
Passed, and it was found that the strength was practically acceptable. In the thermal shock test, cracks did not occur in the translucent low-expansion glass ceramic, and the pearlescent paint layer or the light-shielding layer and the pearlescent paint layer did not peel off from the translucent low-expansion glass ceramic. Therefore, it was found that the pearlescent paint layer had a strong adhesive force.

Further, it was found that the glass ceramics with a pearly tone of the present invention had the same impact strength and thermal shock strength as compared with the N-0 plate having no pearly tone paint layer. Therefore, it is understood that the strength of the glass ceramic is not deteriorated even if the pearl color layer is formed. On the other hand, in Comparative Example 1, in the impact test, the translucent low-expansion glass ceramic was broken at a height of 5 cm.
Although there was no crack in the thermal shock test, the pearlescent paint layer peeled off, indicating that the adhesion strength of the pearlescent paint layer was weak.

[0047]

According to the present invention, it is possible to provide a pearl-tone glass ceramic having a pearl-like effect and exhibiting the original strength of a translucent low-expansion glass ceramic, and a method for producing the same.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of glass ceramics with pearl-like pictures according to first and second embodiments.

FIG. 2 is a cross-sectional view of a glass ceramic with a pearly tone according to Embodiments 3 and 4.

FIG. 3 is an explanatory diagram of the operation of the present invention.

[Explanation of symbols]

 1. . . 9. Si-O-Zr bond, . . 1. Si-O-Si bond, . . 2. Pearl-like material, . . 3. inorganic pigments; . . 4. zirconium oxide coating, . . Light-shielding layer, 6. . . 6. Pearl color layer, . . 7. translucent low expansion glass ceramics; . . 81. Glass ceramic with pearl pattern, . . Front side, 82. . . Back side,

Claims (4)

[Claims] A pearl-like material comprising an inorganic pigment coated with a mixture of zirconium oxide or titanium oxide and zirconium oxide, and a pearl-like paint comprising a silicone resin or a siliceous sol, a translucent low-expansion glass ceramic. A glass ceramic with a pearl tone, characterized by having a pearl color layer formed by sintering. 2. The pearl paint according to claim 1, wherein the content of the pearl material is 0.1 to 10% by weight.
A glass ceramic with a pearl-like picture, characterized in that: 3. The glass ceramic with a pearl tone according to claim 1 or 2, wherein a light-shielding layer is formed after the pearl color layer is formed. 4. A pearl color material comprising an inorganic pigment coated with a mixture of zirconium oxide or titanium oxide and zirconium oxide, and a pearl color material comprising a silicone resin or a siliceous sol, into a translucent low expansion glass ceramic. A method for producing a pearl-painted glass ceramic, comprising a pearl paint layer formed by painting and firing.