JP4998016B2 - Glass top plate for cooker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a glass top plate for a cooker, having high-luminance metallic luster and a manufacturing method for it. <P>SOLUTION: A high reflection film 3, which is mainly composed of one kind or more selected from TiO<SB>2</SB>, CeO<SB>2</SB>and ZrO<SB>2</SB>and has a thickness of 20-300 nm is stacked on the back which is an opposite surface to a cooking surface 21 in a base plate glass 2 formed of transparent low-expansion glass, a pearl tone layer 4 containing a pearl tone material 41 is stacked on the high reflection film 3, and further a light shielding layer 5 is stacked on the pearl tone layer 4. Preferably the high reflection film 5 is formed by applying paste composed of a resinated metal of one or more kinds selected from Ti, Ce and Zr and organic resin to the back 22 of the base plate glass 2, and heat-treating the same. <P>COPYRIGHT: (C)2008,JPO&amp;INPIT

Description

  The present invention relates to a glass top plate for a cooker that is placed on top of the cooker.

  Conventionally, a top plate for a cooker made of a glass plate is installed on the top of a cooker such as an electromagnetic cooker or a gas cooker. An object to be heated such as a pan is placed on the top plate for the cooker, and the object to be heated can be cooked by a heating device inside the cooker. In particular, electromagnetic cookers tend to be increasingly demanded in recent years because of their high safety, and accordingly, the demand for top plates for cookers is also increasing.

As such a top plate for a cooker, techniques (Patent Documents 1 and 2) for applying a decoration with a metallic luster to the substrate glass have been reported in order to enhance the design.
The technique described in Patent Document 1 provides a pearly appearance by arranging a pearly tone layer on the back side of a transparent glass layer and a light shielding layer on the backside of the pearly tone layer. To do. However, there is a problem that the feeling of brightness is small.

  Moreover, the technique of the said patent document 2 is the glass top plate for cookers which expresses metallic luster by forming the decoration layer containing a glossy layer and a light shielding layer on the surface of a transparent low expansion glass plate. It is possible to obtain a metallic luster with high brightness by forming the gloss layer by vapor deposition, but there is a problem that a large vacuum apparatus is required for the production equipment, which is disadvantageous in production.

  For this reason, it has been desired to establish a decoration technique that does not require a manufacturing facility such as a large vacuum apparatus and can express a high-brightness metallic luster by screen printing.

JP 2003-86337 A JP 2004-193050 A

  This invention is made | formed in view of this conventional problem, Comprising: It aims at providing the glass top plate for cookers which has a high-intensity metallic luster.

In the present invention, the back side surface, which is the surface opposite to the cooking surface in the substrate glass made of transparent low expansion glass, is mainly composed of at least one of TiO ₂ , CeO ₂ , and ZrO ₂ and has a thickness of 20 to 300 nm. A high reflection film, a pearly layer containing a pearly material is laminated on the high reflection film, and a light-shielding layer is further laminated on the pearly layer. It exists in a glass top plate (Claim 1).

  The most notable point of the present invention is that a specific high-reflection film having a high reflectance is formed on the back side surface of the substrate glass, and a pearl-tone layer expressing a pearl-like appearance is formed on the high-reflection film. Further, a light shielding layer having a light shielding property is formed on the pearl tone layer. Thereby, when it sees from the cooking surface of the front side, the glass top plate for cookers which has a high-intensity metal luster can be obtained.

The high reflection _film, the thickness as well as a main component one or more of TiO _2, CeO 2, ZrO 2 is 20 to 300 nm.
Since the TiO ₂ , CeO ₂ , and ZrO ₂ have a high refractive index, the highly reflective film has a high reflectance.

  Further, the high reflection film having a high reflectance is present between the back side surface of the substrate glass and the pearl tone layer, so that the color of the light shielding layer exhibited by the pearl tone layer and the light shielding layer is pearl. It is possible to give a sense of brightness to the tone-added color and express a high-brightness metallic luster.

Thus, according to this invention, the glass top plate for cookers which has a high-intensity metallic luster can be obtained.
In addition, the back side surface of the substrate glass is a surface on the heating device side (lower side) opposite to a cooking surface on which a pan or the like is placed when the cooking device is used.

In the present invention, a highly reflective film having a thickness of 20 to 300 nm and a main component of at least one of TiO ₂ , CeO ₂ , and ZrO ₂ is laminated on the back side surface of a substrate glass made of transparent low expansion glass, A pearly tone layer is laminated on the highly reflective film, and a light shielding layer is further laminated on the pearly tone layer.

In the high reflection film, the content of one or more of TiO ₂ , CeO ₂ , and ZrO ₂ is in the range of 50 to 100% when the weight of the entire high reflection film after firing is 100% (the same applies hereinafter). Preferably there is.
When the content of one or more of TiO ₂ , CeO ₂ , and ZrO ₂ is less than 50%, the reflection effect cannot be obtained sufficiently, and a high-brightness metallic luster may not be obtained. The content of one or more of TiO ₂ , CeO ₂ , and ZrO ₂ is more preferably 80 to 100%.

The highly reflective film has a thickness of 20 to 300 nm.
When the thickness of the high reflection film is less than 20 nm, the reflection effect by the high reflection film may not be sufficiently obtained. On the other hand, when the thickness of the highly reflective film exceeds 300 nm, a crack occurs due to a difference in thermal expansion between the substrate glass and the highly reflective film, and the reflection effect of the highly reflective film becomes insufficient due to irregular reflection of light. There is a risk of peeling of the highly reflective film.
The thickness of the highly reflective film is more preferably 40 to 110 nm.

In addition, the high reflection film has a range of SiO ₂ , Al ₂ O ₃ , MgO, Bi ₂ O ₃ , SnO ₂ , In ₂ O ₃ , Sb ₂ O ₃ , transition metal element (Fe) as long as the reflection effect is not hindered. , Co, Ni, Cu, Mn, Cr), or one or more of noble metal elements (Au, Pt, Pd, etc.).

  Further, the portion where the three layers of the highly reflective film, the pearl tone layer, and the light shielding layer are laminated is preferably formed on the whole or part of the back side surface of the substrate glass, and the back side surface of the substrate glass is exposed. There may be part which we did.

The substrate glass is preferably transparent. Here, the term “transparent” means a case where the whiteness w measured by the colorimetric color difference meter is less than 30.
The whiteness w is a numerical value represented by the ratio of the amount of light reflection, where the light reflection amount of the magnesium oxide standard white plate is 100 and true black is 0. Specifically, L, a, and b values are measured with a C2 light source using a colorimetric color difference meter (for example, ZE2000 manufactured by Nippon Denshoku Industries Co., Ltd.), and the following formula W (whiteness) = 100 − [(100− L) ² + a ² + b ² ] ^1/2 .

In the cooking glass top plate, the highly reflective film is formed by applying a heat treatment by applying a paste made of one or more metal resinates of Ti, Ce, and Zr and an organic resin to the back side surface of the substrate glass. (Claim 2).
The method for applying the paste is not particularly limited, and examples thereof include a dipping method, a screen printing method, and a bar coating method.

The metal resinate is a dilute solution of one or more organometallic compounds among Ti, Ce, and Zr, and is a liquid having good dispersibility, and therefore forms a uniform film when forming a highly reflective film. be able to.
Examples of the organic resin include acrylic resins, alkyd resins, and cellulose resins.
Moreover, the said paste may contain the organic solvent as needed.

The highly reflective film may be formed by applying a paste made of one or more metal resinates of Ti, Ce, and Zr and an organic resin to the back side surface of the substrate glass and baking at 600 to 900 ° C. preferable.
When the baking temperature is less than 600 ° C., the high reflection film is hardly sufficiently baked, and the high reflection film may be peeled off after baking. On the other hand, when the said calcination temperature exceeds 900 degreeC, when using transparent crystallized glass as substrate glass, there exists a possibility that substrate glass may become cloudy and metal luster may not be obtained. The firing temperature is more preferably 700 to 850 ° C.

Further, the pearl tone layer is preferably formed by applying a pearl tone paint composed of a pearl tone material, a silicone resin, and an organic resin on the highly reflective film, followed by heat treatment. .
The paste is preferably applied by screen printing.

Examples of the organic resin include acrylic resins, alkyd resins, and cellulose resins.
Moreover, the said paste may contain the organic solvent as needed.
The pearl-tone material is a material obtained by coating a plate-like crystal such as natural mica, synthetic mica, aluminum oxide, or silicon oxide with titanium oxide, iron oxide, or the like.
In addition, a specific iris color can be developed by changing the film thickness of titanium oxide, iron oxide, or the like.

  The silicone resin is a polymer of an organic silicon compound having a skeleton in which a siloxane bond and an organic group are bonded by a chemical reaction with silicon, and is a synthetic resin having both organic and inorganic properties.

Moreover, it is preferable to form the said pearl tone layer by apply | coating a pearl tone paint on the said highly reflective film, and baking at 200-900 degreeC.
When the firing temperature is less than 200 ° C., the pearl tone layer is hardly sufficiently baked, and the pearl tone layer may be peeled off after baking. On the other hand, when the said calcination temperature exceeds 900 degreeC, when using transparent crystallized glass as substrate glass, there exists a possibility that substrate glass may become cloudy and metal luster may not be obtained. The firing temperature is more preferably 700 to 850 ° C.

Moreover, it is preferable that the said pearl color paint contains an inorganic pigment further (Claim 4).
In order to adjust the color of the pearl tone material, the inorganic pigment can be added within a range that does not impair the color of the pearl tone material.

Examples of the inorganic pigment include a white inorganic pigment, a black inorganic pigment, a gray inorganic pigment, a yellow inorganic pigment, a brown inorganic pigment, a green inorganic pigment, a blue inorganic pigment, and a pink inorganic pigment.
Specifically, examples of the white inorganic pigment include TiO ₂ , ZrO ₂ , ZrSiO ₄ , Al ₂ O ₃ , 3Al ₂ O ₃ -2SiO ₂ , and Al ₂ TiO ₅ .

Examples of the black inorganic pigment include Cr-Fe-based oxides, Co-Mn-Cr-Fe-based oxides, Co-Ni-Cr-Fe-based oxides, and Co-Ni-Cr-Fe-Mn-based materials. An oxide etc. are mentioned.
Examples of the gray inorganic pigment include Sn-Sb-based oxides and Sn-Sb-V-based oxides.

Examples of the yellow inorganic pigment include Sn-V oxides, Zr-V oxides, Zr-Si-Pr oxides, Ti-Cr-Sb oxides, and the like.
Examples of the brown inorganic pigment include Zn-Al-Cr-Fe-based oxides and Zn-Mn-Al-Cr-Fe-based oxides.

Examples of the green inorganic pigment include Ca—Cr—Si oxides, Cr—Al oxides, Co—Zn—Al—Cr oxides, and Zr—Si—Pr—V oxides. It is done.
Examples of the blue powder include Co—Al—Zn-based oxides, Co—Al-based oxides, and Zr—Si-based oxides.
Examples of the pink inorganic pigment include Mn—Al oxides, Ca—Sn—Si—Cr oxides, Sn—Cr oxides, and Zr—Si—Fe oxides.
These pigments can be mixed in an arbitrary ratio so as to obtain a desired color.

In addition, it is preferable that the pearl color paint further contains boron nitride.
In this case, the impact strength of the glass top plate for a cooker can be improved.

The boron nitride is preferably contained in an amount of 0.1 to 5% on the basis of 100% of the pearl tone material.
If the boron nitride content is less than 0.1%, the impact strength may not be improved. On the other hand, when the boron nitride content exceeds 5%, the reflection effect may be reduced.
The boron nitride content is more preferably 0.5 to 3%.

The boron nitride is preferably a hexagonal boron nitride powder having an average particle size of 10 μm or less.
When the average particle diameter exceeds 10 μm, the reflection effect may be reduced.
The average particle size of the boron nitride is more preferably 5 μm or less.

The light-shielding layer is preferably formed by applying a paste made of an inorganic pigment, a silicone resin, and an organic resin on the pearl tone layer and heat-treating it (claim 6).
The inorganic pigment described above can be used as the inorganic pigment.
Examples of the organic resin include acrylic resins, alkyd resins, and cellulose resins.

The paste is preferably applied by screen printing.
Moreover, the said paste may contain the organic solvent as needed.
The light shielding layer may be heat-treated at the same time as the pearl tone layer, or may be heat-treated separately from the heat treatment of the pearl tone layer.

The light shielding layer is preferably formed by applying a paste composed of an inorganic pigment, a silicone resin, and an organic resin on the pearl tone layer and baking at 200 to 900 ° C.
When the baking temperature is less than 200 ° C., the light shielding layer is not sufficiently baked, and the light shielding layer may peel off after baking. On the other hand, when the said baking temperature exceeds 900 degreeC, when using transparent crystallized glass as substrate glass, there exists a possibility that substrate glass may become cloudy and the effect of a highly reflective film may be lost. The firing temperature is more preferably 250 to 400 ° C.

Further, the light shielding layer may be formed by applying a raster color on the pearly layer and heat-treating it (claim 7).
The raster color is a diluted solution of an organometallic compound.
Examples of the raster colors include organic materials such as Au, Pt, Pd, Rh, Ru, Bi, Sn, Ni, Fe, Cr, Ti, Ca, Si, Ba, Sr, Mg, Ag, Zr, In, and Mn. A diluted solution of a metal compound can be mentioned. A plurality of these organometallic compound diluted solutions can be mixed at an arbitrary ratio.

The application of the raster color is preferably performed by screen printing.
The light shielding layer may be heat-treated at the same time as the pearl tone layer, or may be heat-treated separately from the heat treatment of the pearl tone layer.

The light-shielding layer composed of the raster color is preferably formed by applying the raster color on the pearly layer and baking it at 600 to 900 ° C.
When the baking temperature is less than 600 ° C., the light shielding layer is not sufficiently baked, and the light shielding layer may be peeled off from the highly reflective film after baking. On the other hand, when the said baking temperature exceeds 900 degreeC, when using transparent crystallized glass as substrate glass, there exists a possibility that substrate glass may become cloudy and the effect of a highly reflective film may be lost. The firing temperature is more preferably 700 to 850 ° C.

Moreover, it is preferable that a heat resistant resin layer made of a heat resistant resin is further formed on the light shielding layer.
In this case, the protective effect which suppresses the damage of the back side surface of substrate glass can be acquired.
The heat-resistant resin layer has little influence on the expression of high brightness metallic luster due to the three layers of the high reflection film, the pearl tone layer, and the light shielding layer.

The heat-resistant resin layer is preferably formed by applying a paste made of a heat-resistant resin on the back side of the light-shielding layer so as to cover a part of the light-shielding layer and baking at 200 to 450 ° C.
The paste is preferably applied by screen printing.
Moreover, the said paste may contain an organic solvent and an inorganic pigment as needed.

When the said baking temperature is less than 200 degreeC, baking of a heat resistant resin layer is hard to be performed sufficiently, and there exists a possibility that a heat resistant resin layer may peel after baking. On the other hand, when the calcination temperature exceeds 450 ° C., the heat-resistant resin disappears and the protective effect may be lost.
The firing temperature is more preferably 250 to 400 ° C.

The heat-resistant resin is preferably a silicone resin, a polyamide resin, a fluororesin, or a composite thereof.
In this case, the above-described protective effect can be obtained particularly well.

The substrate glass preferably has a surface roughness Ra on the back surface side of less than 1.0 μm.
In this case, the high reflection effect of the high reflection film can be obtained.
The surface roughness Ra here is based on JIS B0601-2001.
When the surface roughness Ra of the back side surface of the substrate glass is 1.0 μm or more, even if a film having a high reflectance is formed, the back side surface is not flat and light is irregularly reflected. There is a possibility that it cannot be obtained.

The substrate glass preferably has a linear thermal expansion coefficient of −10 × 10 ⁻⁷ to 80 × 10 ⁻⁷ / K (at 30 to 500 ° C.).
When the linear thermal expansion coefficient of the substrate glass deviates from the range of −10 to 80 × 10 ⁻⁷ / K (at 30 to 500 ° C.), it may not be suitable as a substrate glass used for a glass top plate for a cooker. .

The substrate glass is preferably a transparent low expansion crystallized glass plate having a main crystal of β-quartz solid solution or β-spodumene (claim 12).
The transparent low-expansion crystallized glass having the β-quartz solid solution or β-spodumene as a main crystal is particularly suitable as a substrate glass for a glass top plate for an electromagnetic cooker.

Moreover, it is preferable that the decorating glass decoration layer which consists of a glass composition is formed on the said cooking surface of the said board | substrate glass (Claim 13).
In this case, it is possible to prevent the cooking surface from being damaged by wear of the heated object such as a pan and the cooking surface of the glass top plate for a cooker, or to obtain an effect of making the heated object difficult to slip. it can.
Further, the portion where the substrate glass cooking surface is exposed without the painting glass decoration layer expresses a high-brightness metallic luster, and the portion where the painting glass decoration layer is formed on the cooking surface of the substrate glass is glossy. It is not an expression, and diversity can be given to the design.

Moreover, it is preferable that the ratio which occupies for the said painting glass decoration layer to the said cooking surface is 80% or less. In this case, the wear strength can be maintained without impairing the design. When the area occupied by the decorative glass decorative layer exceeds 80%, the exposed portion of the cooking surface of the glass top plate for a cooker becomes small, which may reduce the design.
The occupied area of the decorative glass decorative layer is more preferably 50% or less.

Moreover, it is preferable that the said decorating glass decoration layer is 1-15 micrometers in thickness. When the film thickness of the decorative glass decorative layer is less than 1 μm, the above-described effects may not be sufficiently obtained. On the other hand, when the film thickness of the said decorative glass decoration layer exceeds 15 micrometers, there exists a possibility that the said decorative glass decoration layer may peel.
The film thickness of the decorative glass decorative layer is more preferably 2 to 10 μm.

The glass composition is preferably a lead-free glass composition in consideration of recyclability and the like.
Moreover, it is preferable that the said glass composition is 650 degrees C or less in a softening point. The glass composition contains SiO ₂ , Al ₂ O ₃ , B ₂ O ₃ , Li ₂ O, Na ₂ O, and K ₂ O as essential components, and if necessary, CaO, SrO, BaO, It is more preferable to use a lead-free glass composition that contains one or more of ZnO, TiO ₂ , and ZrO ₂ as an additive component and is welded by heat treatment at 750 to 900 ° C.

The painted glass decorative layer may contain an inorganic pigment or the like in addition to the glass composition.
The inorganic pigment described above can be used as the inorganic pigment.

Moreover, it is preferable that the said decoration glass decoration layer is formed so that it may become an arbitrary pattern (Claim 14).
In this case, the wear strength can be maintained without impairing the design.
Examples of the arbitrary pattern include a dot shape, a line shape, and a stone shape having a certain area.

Example 1
In this example, a glass top plate (sample E1) for a cooker was produced as an example of the glass top plate for a cooker of the present invention.
As shown in FIG. 1, the glass top plate 1 for a cooker of this example has TiO ₂ as a main component on a back side surface 22 which is a surface opposite to the cooking surface 21 in the substrate glass 2 made of transparent low expansion glass. In addition, a high reflection film 3 having a thickness of 110 nm is laminated, a pearl tone layer 4 containing a pearl tone material 41 is laminated on the high reflection film 3, and a light shielding layer 5 is laminated on the pearl tone layer 4. A heat resistant resin layer 6 made of a heat resistant resin is further laminated on the light shielding layer 5. A decorative glass decoration layer 7 made of a glass composition is formed on the cooking surface 21 of the substrate glass 2.
This will be described in detail below.

As the substrate glass 2, transparent low expansion crystallized glass having a thermal expansion coefficient of 10 × 10 ⁻⁷ / K and a surface roughness Ra of 0.6 μm was used.
As a paste for the highly reflective film 3, a paste having a Ti concentration of 1% composed of a titanium resinate and an organic resin (cellulosic resin) was prepared.

Moreover, as a paste for the pearl tone layer 4, the pearl tone color composition 13% of the pearl tone material component which consists of the pearl tone material 41 (Iriodin 123 by Silver Pearl Merck Co., Ltd.), a silicone resin, and organic resin (cellulosic resin) is used. Prepared.
As the paste for the light shielding layer 5, a black raster painting material was prepared.
Moreover, as the paste for the heat resistant resin layer 6, a paste made of a silicone resin and an organic solvent (xylene) was prepared.

The paste for the decorative glass decoration layer 7 includes SiO ₂ : 65 wt%, Al ₂ O ₃ : 7 wt%, B ₂ O ₃ : 22 wt%, Li ₂ O: 1 wt%, Na _2. A paste containing 97% glass composition consisting of 3% by weight of O and ₂ % by weight of K ₂ O and 3% of an additive consisting of white pigment Al ₂ O ₃ and 100% acrylic resin on the outside is prepared. did.

Next, a manufacturing method will be described.
First, the paste for decoration glass decoration layer was applied onto a part of the cooking surface 21 of the substrate glass 2 using a Tetron 355 mesh screen, and baked at 850 ° C. Thereby, the decorative glass decorative layer 7 having a film thickness of 5 μm and occupying 5% of the cooking surface 21 was formed.

Next, the paste for the high reflection film was applied to the entire back side 22 of the substrate glass 2 using a stainless steel 250 mesh screen, and baked at 850 ° C. Thereby, a highly reflective film 3 having a thickness of 110 nm was formed.
Next, the pearl tone layer paste was applied onto the highly reflective film 3 using a stainless steel 250 mesh screen and baked at 820 ° C. Thereby, a pearl tone layer 4 having a film thickness of 15 μm was formed.

Next, using the stainless steel 350 mesh screen, the light shielding layer paste was applied onto the pearl tone layer 4 and baked at 820 ° C. Thereby, the light shielding layer 5 having a film thickness of 600 nm was formed.
Next, the heat-resistant resin layer paste was applied onto the light shielding layer 5 using a Tetron 200 mesh screen and baked at 350 ° C. Thereby, the heat-resistant resin layer 6 having a film thickness of 20 μm was formed.

Three layers of the high reflection film 3, the pearl tone layer 4 and the light shielding layer 5 are laminated, and the portion where the decorative glass decorative layer does not exist has a high brightness metallic luster and the decorative decorative glass layer 7 exists. The portion to be rendered is an expression with no gloss and a contrast.
The highly reflective film, the pearl tone layer, and the light shielding layer were each formed using a screen printing method. Therefore, the glass top plate for cooking appliances having a high-brightness metallic luster could be produced without requiring a large production apparatus.

In the present example, the above-described four layers are formed on the entire back side surface 22 of the substrate glass 2, but may be a part.
The heat-resistant resin layer 7 hardly affects the metallic luster of the glass top plate 1 for cooking appliances.

(Example 2)
In this example, a glass top plate for a cooker (sample E2) was produced as an example of the present invention.
The glass top plate for a cooker of this example is formed by laminating a highly reflective film having a thickness of 80 nm and containing ZrO ₂ as a main component on the back side of the substrate glass made of transparent low-expansion glass opposite to the cooking surface. A pearl tone layer containing a pearl tone material is laminated on the highly reflective film, a light shielding layer is further laminated on the pearl tone layer, and a heat resistant resin layer made of a heat resistant resin is further formed on the light shielding layer. Are stacked.

As the substrate glass, transparent low expansion crystallized glass having a thermal expansion coefficient of 10 × 10 ⁻⁷ / K and a surface roughness Ra of 0.5 μm was used.
A paste having a Zr concentration of 1.0% composed of zirconia resinate and an organic resin (cellulosic resin) was prepared as a paste for the highly reflective film.

Also, as a paste for the pearl tone layer, a pearl tone paint with a pearl tone material component of 13% made of a pearl tone material (Iriodin 123 manufactured by Silver Pearl Merck Co., Ltd.), a silicone resin, and an organic resin (cellulosic resin) is prepared. did.
Moreover, as the paste for the light shielding layer, a black raster painting material was prepared.
Moreover, as the heat resistant resin layer paste, a paste made of a silicone resin and an organic solvent (xylene) was prepared.

Next, a manufacturing method will be described.
The paste for the high reflection film was applied to the entire cooking surface of the substrate glass using a stainless steel 250 mesh screen and baked at 900 ° C. Thereby, a highly reflective film having a thickness of 80 nm was formed.

Next, the pearl tone layer paste was applied onto the highly reflective film using a stainless steel 250 mesh screen and baked at 900 ° C. As a result, a pearl tone layer having a film thickness of 14 μm was formed.
Next, using the stainless steel 350 mesh screen, the light shielding layer paste was applied onto the pearl tone layer and baked at 820 ° C. Thereby, a light shielding layer having a thickness of 600 nm was formed.

Next, the heat-resistant resin layer paste was applied onto the light shielding layer using a Tetron 200 mesh screen and baked at 350 ° C. Thereby, a heat-resistant resin layer having a thickness of 20 μm was formed.
As a result, a portion where the three layers of the high reflection film, the pearl tone layer, and the light shielding layer are laminated represents a high-luminance metallic luster.

(Example 3)
In this example, a glass top plate for a cooking device (sample E3) was produced as an example of the present invention.
The glass top plate 1 for a cooker of the present example has a high reflection film having a thickness of 40 nm as a main component with TiO ₂ as a main component on the back side which is the surface opposite to the cooking surface in the substrate glass made of transparent low expansion glass. Laminating, laminating a pearl tone layer containing a pearl tone material on the highly reflective film, further laminating a light shielding layer on the pearl tone layer, and further, a heat resistant resin comprising a heat resistant resin on the light shielding layer Layers are stacked. Moreover, the decorating glass decoration layer which consists of a glass composition is formed on the said cooking surface of the said board | substrate glass.

As the substrate glass, transparent low-expansion crystallized glass having a thermal expansion coefficient of 0.4 × 10 ⁻⁷ / K and a surface roughness Ra of 0.7 μm was used.
As a paste for a highly reflective film, a paste having a Ti concentration of 0.75% composed of a titanium resinate and an organic resin (cellulosic resin) was prepared.

Also, as a paste for the pearl tone layer, a pearl tone paint with a pearl tone material component of 13% made of a pearl tone material (Iriodin 123 manufactured by Silver Pearl Merck Co., Ltd.), a silicone resin, and an organic resin (cellulosic resin) is prepared. did.
Moreover, as the paste for the light shielding layer, a black raster painting material was prepared.
Moreover, as the heat resistant resin layer paste, a paste made of a silicone resin and an organic solvent (xylene) was prepared.

The paste for the decorative glass decorative layer includes SiO ₂ : 65 wt%, Al ₂ O ₃ : 7 wt%, B ₂ O ₃ : 22 wt%, Li ₂ O: 1 wt%, Na ₂ O. A paste containing 97% glass composition consisting of 3% by weight, K ₂ O: 2% by weight and 3% additive consisting of white pigment Al ₂ O ₃ and 100% acrylic resin as an outer cover was prepared. .

Next, a manufacturing method will be described.
First, the paste for decorative glass decoration layer was applied to a part of the cooking surface of the substrate glass using a Tetron 355 mesh screen, and baked at 850 ° C. As a result, a decorative glass decorative layer having a film thickness of 5 μm occupying 10% of the cooking surface was formed.

The paste for the high reflection film was applied to the entire back surface of the substrate glass using a stainless 325 mesh screen, and baked at 850 ° C. Thereby, a highly reflective film having a thickness of 40 nm was formed.
Next, the pearl tone layer paste was applied onto the highly reflective film using a stainless steel 250 mesh screen and baked at 820 ° C. Thereby, a pearl tone layer having a film thickness of 13 μm was formed.

Next, using the stainless steel 350 mesh screen, the light shielding layer paste was applied onto the pearl tone layer and baked at 820 ° C. Thereby, a light shielding layer having a thickness of 600 nm was formed.
Next, the heat-resistant resin layer paste was applied onto the light shielding layer using a Tetron 200 mesh screen and baked at 350 ° C. Thereby, a heat-resistant resin layer having a thickness of 20 μm was formed.

  The high reflection film, the pearl tone layer, and the light shielding layer are laminated, and the high-brightness metallic luster is obtained in the portion where the painted glass decorative layer is not present, and the bright portion is present in the portion where the painted glass decorative layer is present. There is no expression and there is a contrasting expression.

Example 4
In this example, a glass top plate for a cooker (sample E4) was produced as an example of the present invention.
The glass top plate for a cooker of this example is formed by laminating a highly reflective film having a thickness of 110 nm and having TiO ₂ as a main component on the back side, which is the surface opposite to the cooking surface in the substrate glass made of transparent low expansion glass. A pearl tone layer containing a pearl tone material is laminated on the highly reflective film, a light shielding layer is further laminated on the pearl tone layer, and a heat resistant resin layer made of a heat resistant resin is further formed on the light shielding layer. Are stacked. Moreover, the decorating glass decoration layer which consists of a glass composition is formed on the said cooking surface of the said board | substrate glass.

As the substrate glass, transparent low-expansion crystallized glass having a thermal expansion coefficient of 0.4 × 10 ⁻⁷ / K and a surface roughness Ra of 0.6 μm was used.
As a paste for the high reflection film, a paste having a Ti concentration of 1% composed of titanium resinate and an organic resin (cellulose-based resin) was prepared.

In addition, as a paste for a pearl tone layer, a pearl tone paint having a pearl tone material component of 13% composed of a pearl tone material (Iriodin 123 manufactured by Silver Pearl Merck Co., Ltd.), a silicone resin, and an organic resin (cellulosic resin), Further, a pearl color paint was prepared by adding 0.8% boron nitride (SP-2 manufactured by Denki Kagaku Kogyo Co., Ltd.) to the pearl color material.
Moreover, as the paste for the light shielding layer, a black raster painting material was prepared.
Moreover, as the heat resistant resin layer paste, a paste made of a silicone resin and an organic solvent (xylene) was prepared.

The paste for the decorative glass decorative layer includes SiO ₂ : 65 wt%, Al ₂ O ₃ : 7 wt%, B ₂ O ₃ : 22 wt%, Li ₂ O: 1 wt%, Na ₂ O. A paste containing 97% glass composition consisting of 3% by weight, K ₂ O: 2% by weight and 3% additive consisting of white pigment Al ₂ O ₃ and 100% acrylic resin as an outer cover was prepared. .

Next, a manufacturing method will be described.
First, the paste for decorative glass decoration layer was applied to a part of the cooking surface of the substrate glass using a Tetron 355 mesh screen, and baked at 850 ° C. As a result, a decorative glass decorative layer having a film thickness of 5 μm occupying 5% of the cooking surface was formed.

The paste for the high reflection film was applied to the entire back side surface of the substrate glass using a stainless steel 250 mesh screen, and baked at 850 ° C. Thereby, a highly reflective film having a film thickness of 110 nm was formed.
Next, the pearl tone layer paste was applied onto the highly reflective film using a stainless steel 250 mesh screen and baked at 820 ° C. Thereby, a pearl tone layer having a film thickness of 15 μm was formed.

Next, using the stainless steel 350 mesh screen, the light shielding layer paste was applied onto the pearl tone layer and baked at 820 ° C. Thereby, a light shielding layer having a thickness of 600 nm was formed.
Next, the heat-resistant resin layer paste was applied onto the light shielding layer using a Tetron 200 mesh screen and baked at 350 ° C. Thereby, a heat-resistant resin layer having a thickness of 20 μm was formed.

  The high reflection film, the pearl tone layer, and the light shielding layer are laminated, and the high-brightness metallic luster is obtained in the portion where the painted glass decorative layer is not present, and the bright portion is present in the portion where the painted glass decorative layer is present. There is no expression and there is a contrasting expression.

(Example 5)
In this example, a glass top plate for a cooker (sample E5) was produced as an example of the present invention.
In this example, the pearl tone layer paste of Example 4 is changed.
Specifically, the paste for the pearl tone layer is a pearl tone material having a pearl tone material component of 13% composed of a pearl tone material (Iriodin 123 manufactured by Silver Pearl Merck Co., Ltd.), a silicone resin, and an organic resin (cellulosic resin). In addition, a pearl-colored paint in which boron nitride (SP-2 manufactured by Denki Kagaku Kogyo Co., Ltd.) was further added to the pearl-colored material by 2.5% was prepared.
Others were the same as in Example 4.

(Example 6)
In this example, a glass top plate for a cooker (sample E5) was produced as an example of the present invention.
In this example, the pearl tone layer paste of Example 4 is changed.
Specifically, the paste for the pearl tone layer is a pearl tone material having a pearl tone material component of 13% composed of a pearl tone material (Iriodin 123 manufactured by Silver Pearl Merck Co., Ltd.), a silicone resin, and an organic resin (cellulosic resin). A pearl-colored paint was further prepared by adding 4.2% boron nitride (SP-2 manufactured by Denki Kagaku Kogyo Co., Ltd.) to the pearl-colored material.
Others were the same as in Example 4.

(Example 7)
In this example, a glass top plate for a cooker (sample E5) was produced as an example of the present invention.
In this example, the pearl tone layer paste of Example 4 is changed.
Specifically, the paste for the pearl tone layer is a pearl tone material having a pearl tone material component of 13% composed of a pearl tone material (Iriodin 123 manufactured by Silver Pearl Merck Co., Ltd.), a silicone resin, and an organic resin (cellulosic resin). Further, a pearl-colored paint in which 0.08% of boron nitride (SP-2 manufactured by Denki Kagaku Kogyo Co., Ltd.) was added to the pearl-colored material as an outer coating was prepared.
Others were the same as in Example 4.

(Example 8)
In this example, a glass top plate for a cooker (sample E5) was produced as an example of the present invention.
In this example, the pearl tone layer paste of Example 4 is changed.
Specifically, the paste for the pearl tone layer is a pearl tone material having a pearl tone material component of 13% composed of a pearl tone material (Iriodin 123 manufactured by Silver Pearl Merck Co., Ltd.), a silicone resin, and an organic resin (cellulosic resin). In addition, a pearl-colored paint in which boron nitride (SP-2 manufactured by Denki Kagaku Kogyo Co., Ltd.) was further added to the pearl-colored material by 5.1% was prepared.
Others were the same as in Example 4.

(Comparative Example 1)
In this example, a glass top plate for a cooker (sample C1) was produced as a comparative example of the present invention.
The glass top plate for a cooker of this example is formed by laminating a pearl tone layer containing a pearl tone material directly on the back side which is the surface opposite to the cooking surface in the substrate glass made of transparent low expansion glass, and A light shielding layer is laminated on the adjustment layer, and a heat resistant resin layer made of a heat resistant resin is further laminated on the light shielding layer.

As the substrate glass, a transparent low-expansion crystallized glass having a thermal expansion coefficient of 0.5 × 10 ⁻⁷ / K and a surface roughness Ra of 0.6 μm was used.
As the paste for the pearl tone layer, a pearl tone paint having a pearl tone material component of 15% made of a pearl tone material (Iriodin 123 manufactured by Silver Pearl Merck Co., Ltd.), a silicone resin, and an organic resin (cellulosic resin) was prepared. .

Further, as the paste for the upper light shielding layer, a black raster painting material was prepared.
Moreover, as the paste for the heat resistant resin layer, a paste made of a silicone resin and an organic solvent (toluene) was prepared.

The paste for the decorative glass decorative layer includes SiO ₂ : 65 wt%, Al ₂ O ₃ : 7 wt%, B ₂ O ₃ : 22 wt%, Li ₂ O: 1 wt%, Na ₂ O. A paste containing 97% glass composition consisting of 3% by weight, K ₂ O: 2% by weight and 3% additive consisting of white pigment Al ₂ O ₃ and 100% acrylic resin as an outer cover was prepared. .

Next, a manufacturing method will be described.
The pearl tone layer paste was applied to the entire back surface of the substrate glass using a stainless steel 250 mesh screen, and baked at 820 ° C. Thereby, a pearl tone layer having a film thickness of 15 μm was formed.

Next, using the stainless steel 350 mesh screen, the light shielding layer paste was applied onto the pearl tone layer and baked at 820 ° C. Thereby, a light shielding layer having a thickness of 600 nm was formed.
Next, the heat-resistant resin layer paste was applied onto the light shielding layer using a Tetron 200 mesh screen and baked at 350 ° C. Thereby, a heat-resistant resin layer having a thickness of 20 μm was formed.

(Comparative Example 2)
In this example, a glass top plate for a cooker (sample C2) was produced as a comparative example of the present invention.
The glass top plate for a cooker in this example is formed by laminating a highly reflective film having a thickness of 320 nm as a main component with TiO ₂ on the back side surface, which is the surface opposite to the cooking surface in the substrate glass made of transparent low expansion glass. A pearl tone layer containing a pearl tone material is laminated on the highly reflective film, a light shielding layer is further laminated on the pearl tone layer, and a heat resistant resin layer made of a heat resistant resin is further formed on the light shielding layer. Are stacked. Moreover, the decorating glass decoration layer which consists of a glass composition is formed on the said cooking surface of the said board | substrate glass.

As the substrate glass, transparent low-expansion crystallized glass having a thermal expansion coefficient of 1.0 × 10 ⁻⁷ / K and a surface roughness Ra of 0.6 μm was used.
A paste having a Ti concentration of 3% composed of a titanium resinate and an organic resin (cellulosic resin) was prepared as a paste for the highly reflective film.

In addition, as a paste for the pearl tone layer, a pearl tone paint having a pearl tone material component of 15% made of a pearl tone material (Iriodin 123 manufactured by Silver Pearl Merck Co., Ltd.), silicone resin, and organic resin (cellulosic resin) is prepared. did.
Moreover, as the paste for the light shielding layer, a black raster painting material was prepared.
Moreover, as the heat resistant resin layer paste, a paste made of a silicone resin and an organic solvent (xylene) was prepared.

The paste for the decorative glass decorative layer includes SiO ₂ : 65 wt%, Al ₂ O ₃ : 7 wt%, B ₂ O ₃ : 22 wt%, Li ₂ O: 1 wt%, Na ₂ O. A paste containing 97% glass composition consisting of 3% by weight, K ₂ O: 2% by weight and 3% additive consisting of white pigment Al ₂ O ₃ and 100% acrylic resin as an outer cover was prepared. .

Next, a manufacturing method will be described.
First, the paste for decorative glass decoration layer was applied to a part of the cooking surface of the substrate glass using a Tetron 355 mesh screen, and baked at 850 ° C. As a result, a decorative glass decorative layer having a film thickness of 5 μm, which occupies 15% of the cooking surface, was formed.

The paste for the high reflection film was applied to the entire back side surface of the substrate glass using a stainless 200 mesh screen and baked at 850 ° C. Thereby, a highly reflective film having a thickness of 320 nm was formed.
Next, the pearl tone layer paste was applied onto the highly reflective film using a stainless steel 250 mesh screen and baked at 820 ° C. Thereby, a pearl tone layer having a film thickness of 15 μm was formed.

Next, using the stainless steel 350 mesh screen, the light shielding layer paste was applied onto the pearl tone layer and baked at 820 ° C. Thereby, a light shielding layer having a thickness of 600 nm was formed.
Next, the heat-resistant resin layer paste was applied onto the light shielding layer using a Tetron 200 mesh screen and baked at 350 ° C. Thereby, a heat-resistant resin layer having a thickness of 20 μm was formed.

In this example, as a comparative example of the present invention, a commercially available glass top plate for a cookware with silver reflection decorated by backside sputtering (sample C3) was prepared.
That is, a highly reflective film, a pearl tone layer, and a light shielding film are not formed on the back side surface of the substrate glass.
In order to manufacture this sample C3, a large vacuum apparatus is required in the manufacturing facility.

  Here, in Table 1, the glass top plates for cookers (Samples E1 to E8) of Examples 1 to 8 and the glass top plates for cookers (Samples C1 to C3) of Comparative Examples 1 to 3 are shown on the back side. The surface roughness Ra, the main component and thickness of the highly reflective film, and the boron nitride content of the pearl tone layer (outer coating for the pearl component) are shown. The surface roughness was measured as follows.

<Surface roughness>
Using SURFCOM130 manufactured by Tokyo Seimitsu Co., Ltd., the surface roughness Ra of the back side surface of the substrate glass was measured.

Table 2 shows the visible light reflectance and lightness index L ^* values of Sample E1 to Sample E8 and Sample C1 to Sample C3. The visible light reflectance and the brightness index L ^* value were measured as follows.

<Visible light reflectance>
Using a UV-Vis spectrophotometer V-570 manufactured by JASCO Corporation and an integrating sphere device ISN-570, the spectral reflection curve was measured. According to JIS R 3106, the visible light reflectance was determined by calculation. The measurement was performed from the cooking surface of the substrate glass. The visible light reflectance is preferably 37% or more, and more preferably 40% or more.

<Lightness index L ^* value>
The lightness index L ^* value was determined using an integrating sphere spectrocolorimeter SP60 manufactured by X-Rite. The measurement was performed from the cooking surface of the substrate glass. The lightness index L ^* value is preferably 70 or more, and more preferably 71 or more.

(Experimental example 1)
In this example, first, the glass top plates for cooking utensils of Examples 1 to 8 and Comparative Example 2 in which a highly reflective film is formed between the back side surface of the substrate glass and the pearl tone layer (samples E1 to E8). For sample C2), a glass top plate having the same configuration was prepared except that a highly reflective film was not formed. And the following items were evaluated. The results are shown in Table 2.

<Reflection effect>
Divide the difference in visible light reflectance with and without the high reflective film by the visible light reflectance without the high reflective film and multiply by 100 to obtain the percentage, and reflect within the range of that value. The effect was evaluated. The case where evaluation is (circle) and (triangle | delta) is a pass, and the case where evaluation is x is made disqualified.

(Evaluation criteria)
○: When the reflection effect is 20% or more.
Δ: When the reflection effect is 5% or more and less than 20% ×: When the reflection effect is less than 5%

<Brightness improvement>
Divide the brightness index difference between the high reflection film and the absence of the high reflection film by the brightness index when there is no high reflection film and multiply by 100 to obtain the percentage. evaluated. The case where evaluation is (circle) and (triangle | delta) is a pass, and the case where evaluation is x is made disqualified.

(Evaluation criteria)
○: Brightness improvement is 5% or more.
Δ: Brightness improvement is 1% or more and less than 5%.
X: When the brightness improvement is less than 1%.

(Experimental example 2)
Next, in this example, the sample E1 in which the pearl tone layer produced in Example 1 does not contain boron nitride, and the sample E4 in which the pearl tone layer produced in Examples 4 to 8 contains boron nitride. Sample E8 was subjected to a drop test of a steel ball ball, and samples E4 to E8 were evaluated for the impact strength improvement effect. The results are shown in Table 2.

(Drop test of steel ball)
In the drop test of the steel ball ball, the cooking surface of the glass top plate for a cooker was turned up, the steel ball ball was freely dropped, and the height of the broken ball that broke the glass top plate for the cooker was measured.

Specifically, first, a square test piece of 400 mm × 400 mm square was cut from a glass top plate for a cooker. The test piece was placed on the frame of the test apparatus with the cooking surface up. Then, a steel ball-made spherical ball having a weight of 540 g was freely dropped onto the test piece. The falling height of the steel ball was raised step by step until the specimen was broken.
About each sample, the drop test was performed 5 times and let the average value of the falling ball height at which the test piece was damaged be the broken falling ball height.

(Evaluation of impact strength improvement effect)
The impact strength improvement effect is the difference between the height of the broken ball and the height of the broken ball of sample E1 that does not contain boron nitride in the pearl tone layer for each of samples E4 to E8. And then multiplied by 100 to determine the percentage. When the improvement effect is recognized, the evaluation is ○, and when the improvement effect is not recognized, the evaluation is Δ.

(Evaluation criteria)
○: When the impact strength improvement is 20% or more.
Δ: Impact strength improvement is 0% or more and less than 20%.

As is known from Table 2, Sample E1 to Sample E8 as examples of the present invention have sufficient visible light reflectance and lightness index L ^* value, and are good in both items of reflection effect and lightness improvement. Results are shown.
Moreover, since the sample E4-the sample E6 as an Example of this invention contain boron nitride in the pearl tone layer, the improvement in impact strength was seen.

Further, as can be seen from Table 2, since the sample C1 as a comparative example of the present invention does not form a highly reflective film between the substrate glass and the pearl tone layer, the visible light reflectance and the brightness index L ^* value Was insufficient, and a high-brightness metallic luster could not be obtained.

Sample C2 as a comparative example of the present invention has a film thickness of the high reflection film exceeding the upper limit of the present invention, cracks are generated due to the thermal expansion of the substrate glass and the high reflection film, and high reflection is caused by irregular reflection of light. The reflection effect of the film was insufficient, the visible light reflectance and the lightness index L ^* value were insufficient, and the reflection effect and lightness improvement were unacceptable.
Sample C3 as a comparative example of the present invention has sufficient visible light reflectance and lightness index L ^* value, and has a high metallic luster, but requires a large vacuum apparatus in the production facility. This is disadvantageous in manufacturing.

Thus, by providing a specific highly reflective film between the substrate glass and the pearl tone layer, and providing a light-shielding layer on the pearl tone layer, the reflection effect and lightness can be achieved as compared with the case where the highly reflective film is not provided. It can be seen that high brightness and metallic luster can be expressed.
Therefore, according to this invention, the glass top plate for cookers which has a high-intensity metallic luster can be obtained.

Explanatory drawing which shows the glass top plate for cookers in Example 1. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Glass top plate for cookers 2 Substrate glass 21 Cooking surface 22 Back side surface 3 High reflection film 4 Pearl tone layer 5 Light-shielding layer 6 Heat-resistant resin layer 7 Painted glass decoration layer

Claims (14)

High reflectivity having a thickness of 20 to 300 nm with a main component of at least one of TiO ₂ , CeO ₂ , and ZrO _{2 on} the back side that is the surface opposite to the cooking surface of the substrate glass made of transparent low expansion glass. A glass top plate for a cooking appliance, comprising: a film, a pearly layer containing a pearly material on the highly reflective film, and a light-shielding layer on the pearly layer.   2. The high reflection film according to claim 1, wherein the highly reflective film is formed by applying a heat treatment by applying a paste made of at least one metal resinate among Ti, Ce, and Zr and an organic resin to the back side surface of the substrate glass. A glass top plate for cooking appliances.   3. The pearl tone layer according to claim 1, wherein the pearl tone layer is formed by applying a pearl tone paint composed of a pearl tone material, a silicone resin, and an organic resin on the highly reflective film and performing a heat treatment. Glass top plate for cookware.   4. The glass top plate for a cooker according to claim 3, wherein the pearl color paint further contains an inorganic pigment.   4. The glass top plate for a cooker according to claim 2, wherein the pearl color paint further contains boron nitride.   6. The light-shielding layer according to claim 1, wherein the light-shielding layer is formed by applying a paste made of an inorganic pigment, a silicone resin, and an organic resin on the pearl tone layer and heat-treating the paste. Characteristic glass top plate for cookers.   6. The glass top plate for a cooker according to any one of claims 1 to 5, wherein the light shielding layer is formed by applying a raster color on the pearl tone layer and performing a heat treatment.   The glass top plate for a cooker according to any one of claims 1 to 7, wherein a heat resistant resin layer made of a heat resistant resin is further formed on the light shielding layer.   9. The glass top plate for a cooker according to claim 8, wherein the heat resistant resin is a silicone resin, a polyamide resin, a fluororesin, or a composite thereof.   10. The glass top plate for a cooker according to claim 1, wherein the substrate glass has a surface roughness Ra on the back side of less than 1.0 μm. 11. The cooking according to claim 1, wherein the substrate glass has a linear thermal expansion coefficient of −10 × 10 ⁻⁷ to 80 × 10 ⁻⁷ / K (at 30 to 500 ° C.). Glass top plate for dexterity.   The glass top plate for a cooker according to any one of claims 1 to 11, wherein the substrate glass is a transparent low expansion crystallized glass plate whose main crystal is β-quartz solid solution or β-spodumene.   The glass top plate for a cooker according to any one of claims 1 to 12, wherein a decorative glass decorative layer made of a glass composition is formed on the cooking surface of the substrate glass.   14. The glass top plate for a cooker according to claim 13, wherein the decorative glass decorative layer is formed to have an arbitrary pattern.

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