JP2023181056A - Top plate for cookers - Google Patents

Abstract

To provide a top plate for cookers having superior thermal shock resistance.SOLUTION: A top plate for cookers includes: a glass substrate having a cooking face where cooking utensils are placed and a rear face opposite the cooking face; and a heat-resistant resin layer disposed on the rear face of the glass substrate. The heat-resistant resin layer includes a first layer including silicone resin and pigments. The first layer is in contact with the rear face of the glass substrate. The pigments in the first layer include an acicular crystal pigment and a second pigment. When the total mass of the first layer is considered as 100 mass%, the content of these pigments is 51 mass% or more and less than 72 mass%. In 100 mass% of these pigments in the first layer, the acicular crystal pigment makes up 30 mass% or more and 70 mass% or less.SELECTED DRAWING: Figure 1

Description

The present invention relates to a top plate for a cooker.

A cooker top plate is provided on the upper part of an electromagnetic cooker, a radiant heater cooker, a gas cooker, and the like. The above-mentioned top plate for a cooker includes a transparent glass substrate having a cooking surface on which cooking utensils are placed and a back surface opposite to the cooking surface. Furthermore, a heat-resistant resin layer containing silicone resin is provided on the back surface of the glass substrate in order to hide the internal structure of the cooking device.

For example, Patent Document 1 below includes a glass plate and a heat-resistant resin layer provided in contact with the back surface of the glass plate, and the heat-resistant resin layer includes a heat-resistant resin and a flaky aluminum filler. A top plate for a cooker is disclosed.

Further, Patent Document 2 below includes a glass plate and a heat-resistant resin layer provided in contact with the back surface of the glass plate, and the heat-resistant resin layer includes a heat-resistant resin and a flake-like material having a Mohs hardness of 3 or more. Disclosed is a top plate for a cooker that includes an inorganic filler.

International Publication No. 2020-130064 Japanese Patent Application Publication No. 2020-094799

The top plate for a cooker may cool down rapidly during use. For example, if you start cooking immediately after one cooking process, such as by placing a pot filled with cold water on top of the top plate where a hot frying pan was previously placed, the top plate will move quickly. cooled down. At this time, the top plate may be exposed to a temperature difference of 500° C. or more. Therefore, the top plate is required to have high thermal shock resistance. However, with conventional top plates, when rapidly cooled due to a large temperature difference, the heat-resistant resin layer peels off from the glass substrate due to the difference in thermal contraction between the glass substrate, which is made of different materials, and the heat-resistant resin layer, which is mainly made of silicone resin. Otherwise, cracks or cracks may occur in the heat-resistant resin layer.

An object of the present invention is to provide a top plate for a cooker that has excellent thermal shock resistance.

The top plate for a cooker according to aspect 1 of the present invention includes a glass substrate having a cooking surface on which a cooking utensil is placed and a back surface opposite to the cooking surface, and disposed on the back surface of the glass substrate. a heat-resistant resin layer, the heat-resistant resin layer has a first layer containing a silicone resin and a pigment, the first layer is in contact with the back surface of the glass substrate, and the first layer is in contact with the back surface of the glass substrate; The pigment in the first layer includes an acicular crystal pigment and a second pigment, and the content of the pigment is 51% by mass or more and less than 72% by mass in 100% by mass of the first layer. The content of the acicular crystal pigment is 30% by mass or more and 70% by mass or less in 100% by mass of the pigment in the first layer.

In the top plate for a cooker according to Aspect 2, in Aspect 1, it is preferable that the silicone resin in the first layer has a siloxane bond content of 40% by mass or more.

In the top plate for a cooker according to Aspect 3, in Aspect 1 or Aspect 2, the acicular crystal pigment in the first layer is at least one selected from the group consisting of potassium titanate, calcium silicate, and titanium oxide. It is preferable to include one type.

In the top plate for a cooker according to Aspect 4, in any one of Aspects 1 to 3, it is preferable that the acicular crystal pigment in the first layer contains potassium titanate.

In the top plate for a cooker according to Aspect 5, in any one of Aspects 1 to 4, it is preferable that the second pigment in the first layer contains a colored pigment.

In the top plate for a cooker according to aspect 6, in any one of aspects 1 to 5, it is preferable that the heat-resistant resin layer has a one-layer structure including only the first layer.

In the top plate for a cooker according to aspect 7, in any one of aspects 1 to 5, the heat-resistant resin layer includes the first layer, a silicone resin, and a second layer containing a pigment; It is preferable that the second layer is located on a side opposite to the glass substrate side in the heat-resistant resin layer.

In the cooking device top plate according to aspect 8, in any one of aspects 1 to 7, the cooking device top plate includes an inorganic layer disposed between the glass substrate and the heat-resistant resin layer. Preferably, the inorganic layer further includes glass and a pigment.

According to the present invention, it is possible to provide a top plate for a cooker that has excellent thermal shock resistance.

FIG. 1 is a schematic cross-sectional view showing a top plate for a cooker according to a first embodiment of the present invention. FIG. 2 is a schematic cross-sectional view showing a top plate for a cooker according to a second embodiment of the present invention. FIG. 3 is a schematic cross-sectional view showing a top plate for a cooker according to a third embodiment of the present invention.

Preferred embodiments will be described below. However, the following embodiments are merely illustrative, and the present invention is not limited to the following embodiments. Further, in each drawing, members having substantially the same function may be referred to by the same reference numerals.

In addition, in this specification, a "top plate for a cooker" may be abbreviated as a "top plate."

[First embodiment]
FIG. 1 is a schematic cross-sectional view showing a top plate for a cooker according to a first embodiment of the present invention.

A top plate 1 for a cooking appliance shown in FIG. 1 includes a glass substrate 2. The top plate 1 shown in FIG. Glass substrate 2 has a cooking surface 2a and a back surface 2b. The cooking surface 2a and the back surface 2b are surfaces facing each other. The cooking surface 2a is a surface on which cooking utensils such as pots and frying pans are placed. The back surface 2b is a surface facing a light source and a heating device on the inside side of the cooking appliance. Therefore, the cooking surface 2a and the back surface 2b are in a front-back relationship.

A heat-resistant resin layer 3 is arranged on the back surface 2b of the glass substrate 2. The back surface 2b of the glass substrate 2 and the heat-resistant resin layer 3 are in contact with each other. In this embodiment, the heat-resistant resin layer 3 has a first layer 4 and a second layer 5. A first layer 4 is arranged on the back surface 2b of the glass substrate 2, and a second layer 5 is arranged on the first layer 4. The first layer 4 is in contact with the back surface 2b of the glass substrate 2. The first layer 4 is located on the glass substrate 2 side in the heat-resistant resin layer 3. The second layer 5 is located on the opposite side of the glass substrate 2 in the heat-resistant resin layer 3 .

The first layer 4 includes silicone resin and pigment. Further, the second layer 5 includes a silicone resin and a pigment.

The pigment in the first layer 4 includes an acicular crystal pigment and a second pigment. The content of the pigment in the first layer 4 (the content of the pigment in 100% by mass of the first layer) is 51% by mass or more and less than 72% by mass. The content of the acicular crystal pigment in 100% by mass of the pigment in the first layer 4 is 30% by mass or more and 70% by mass or less.

Since the top plate 1 has the above configuration, it has excellent thermal shock resistance.

With conventional top plates, when rapidly cooled due to a large temperature difference, the heat-resistant resin layer peels off from the glass substrate due to the difference in thermal contraction between the glass substrate, which is a dissimilar material, and the heat-resistant resin layer, which is mainly made of silicone resin. In some cases, cracks or cracks may occur in the heat-resistant resin layer.

In contrast, the present inventor focused on the layer (first layer) that directly contacts the glass substrate in the heat-resistant resin layer, and set the content and type of pigment in the first layer to a specific configuration. It has been found that the thermal shock resistance of the top plate can be improved by this method.

That is, in the top plate 1, even when the top plate 1 is rapidly cooled due to a large temperature difference, thermal contraction of the first layer 4 can be suppressed, so that peeling of the heat-resistant resin layer 3 from the glass substrate 2 is less likely to occur. . Moreover, cracks and cracks are less likely to occur in the heat-resistant resin layer 3.

Hereinafter, details of the members and each layer constituting the top plate 1 will be explained.

(Glass substrate)
It is preferable that the glass substrate 2 is a glass substrate that transmits at least part of light in a wavelength range of 450 nm to 700 nm. It is preferable that the glass substrate 2 is a transparent glass substrate. Although the glass substrate 2 may be colored and transparent, it is preferably colorless and transparent from the viewpoint of further enhancing the aesthetic appearance of the top plate 1. Note that in this specification, the term "transparent" in a glass substrate means that the light transmittance in the visible wavelength range of 450 nm to 700 nm is 70% or more.

The top plate 1 is repeatedly heated and cooled. Therefore, it is preferable that the glass substrate 2 has high thermal shock resistance and a low coefficient of thermal expansion. Specifically, the softening temperature of the glass substrate 2 is preferably 700°C or higher, more preferably 750°C or higher. Further, the average linear thermal expansion coefficient of the glass substrate 2 at 30°C to 750°C is preferably within the range of -10x10 ^-7 /°C to +60x10 ^-7 /°C, and -10x10 ^-7 It is more preferably within the range of /°C to +50×10 ⁻⁷ /°C, and even more preferably within the range of −10×10 ⁻⁷ /°C to +40×10 ⁻⁷ /°C. Therefore, the glass substrate 2 is preferably made of glass having a high glass transition temperature and low expansion, or crystallized glass. Specific examples of low-expansion crystallized glass include "N-0" manufactured by Nippon Electric Glass Co., Ltd., which is LAS-based crystallized glass. Note that a borosilicate glass substrate or the like may be used as the glass substrate 2.

The thickness of the glass substrate 2 is not particularly limited. The thickness of the glass substrate 2 can be appropriately set depending on the light transmittance and the like. The thickness of the glass substrate 2 can be, for example, about 2 mm to 6 mm.

(Heat-resistant resin layer)
The heat-resistant resin layer 3 is arranged on the back surface 2b of the glass substrate 2. The heat-resistant resin layer 3 has a two-layer structure. That is, the heat-resistant resin layer 3 includes a first layer 4 and a second layer 5 disposed on the surface of the first layer 4 on the opposite side to the glass substrate 2 side. Note that the first layer 4 and the second layer 5 are preferably colored in different colors. For example, the first layer 4 can be a white layer and the second layer 5 can be a gray layer. However, the colors of the first layer 4 and the second layer 5 are not particularly limited, and can be appropriately determined in consideration of the design and the concealability of the internal structure of the cooker. Moreover, the heat-resistant resin layer 3 may have a structure of three or more layers.

<Silicone resin>
In the following description, the common structure of the silicone resin used in the heat-resistant resin layer or each layer of the heat-resistant resin layer will be simply referred to as "silicone resin", and the silicone resin used in the first layer 4 and the second layer 5 will be referred to as "silicone resin". The individual structures of are referred to as "the silicone resin in the first layer 4" and "the silicone resin in the second layer 5."

Heat-resistant resin layer 3 contains silicone resin. The first layer 4 contains silicone resin. It is preferable that the second layer 5 contains silicone resin. When the heat-resistant resin layer 3 has a structure of two or more layers, it is preferable that all layers of the heat-resistant resin layer 3 contain silicone resin. Only one kind of the above-mentioned silicone resin may be used, or two or more kinds thereof may be used in combination. Note that the silicone resins contained in each layer of the heat-resistant resin layer 3 may be the same or different.

The silicone resin in the first layer 4 preferably has a siloxane bond content of 40% by mass or more. When the content of the siloxane bonds is 40% by mass or more, the content ratio of inorganic structural parts that are difficult to thermally decompose in the silicone resin increases, so even when the top plate 1 is heated to a high temperature, the heat of the first layer 4 Shrinkage can be reduced. Therefore, it is possible to prevent the heat-resistant resin layer 3 from peeling off from the glass substrate 2 and to prevent cracks or cracks from occurring in the heat-resistant resin layer 3, thereby increasing the thermal shock resistance of the top plate 1.

The content of siloxane bonds in the silicone resin in the first layer 4 is more preferably 45% by mass or more, preferably 80% by mass or less, and more preferably 75% by mass or less. When the content of the siloxane bonds is not less than the above lower limit and not more than the above upper limit, the above effects can be exhibited even more effectively.

The content of siloxane bonds in the silicone resin in the second layer 5 is preferably 40% by mass or more, more preferably 45% by mass or more, and preferably 80% by mass or less, and 75% by mass or more. It is more preferable that it is less than % by mass. When the content of the siloxane bonds is not less than the above lower limit and not more than the above upper limit, the above effects can be exhibited even more effectively.

The content of siloxane bonds in the silicone resin is the ratio (% by mass) of the total mass of siloxane bonds contained in the silicone resin to the total mass of atoms constituting the silicone resin. More specifically, the total mass of the siloxane bonds contained in the silicone resin is the total mass of silicon atoms and oxygen atoms that constitute the siloxane bonds contained in the silicone resin.

The content of siloxane bonds in the silicone resin can be calculated from the structural formula of the silicone resin component that is the material of the silicone resin.

It is preferable to use a silicone resin having high heat resistance as the silicone resin. From the viewpoint of further increasing the heat resistance of the heat-resistant resin layer 3 and effectively suppressing discoloration of the heat-resistant resin layer 3 when the top plate 1 becomes high temperature, the silicone resin in the first layer 4 and the second All silicone resins in layer 5 are preferably silicone resins having, for example, a methyl group or a phenyl group as a functional group. In this case, for example, a methyl group may be directly bonded to a silicon atom, a phenyl group may be directly bonded to a silicon atom, or a methyl group and a phenyl group may be directly bonded to the same silicon atom. It's okay.

A commercially available product can also be used as the silicone resin component that can satisfactorily obtain a silicone resin having a siloxane bond content of 40% by mass or more. Commercially available products that can be used as the silicone resin component include, for example, "Straight Silicone Varnish KR282", "Straight Silicone Varnish KR271", "Straight Silicone Varnish KR311" manufactured by Shin-Etsu Chemical Co., Ltd., and "TSR-145" manufactured by Momentive. etc.

The content of the silicone resin in the first layer 4 (the content of the silicone resin in 100% by mass of the first layer) is preferably 20% by mass or more, more preferably 30% by mass or more, and still more preferably 32% by mass or more. It is at least 47% by mass, more preferably at most 45% by mass. When the content of the silicone resin is equal to or higher than the lower limit, the heat resistance, solvent resistance, adhesion, and mechanical strength of the heat-resistant resin layer 3 can be further improved. When the content of the silicone resin is below the upper limit, the mechanical strength of the heat-resistant resin layer 3 can be further increased.

The content of the silicone resin in the second layer 5 (the content of the silicone resin in 100% by mass of the second layer) is preferably 20% by mass or more, more preferably 30% by mass or more, and preferably 70% by mass. % or less, more preferably 60% by mass or less. When the content of the silicone resin is equal to or higher than the lower limit, the heat resistance, solvent resistance, adhesion, and mechanical strength of the heat-resistant resin layer 3 can be further improved. When the content of the silicone resin is below the upper limit, the mechanical strength of the heat-resistant resin layer 3 can be further increased.

The content of the silicone resin in the heat-resistant resin layer 3 (the content of silicone resin in 100% by mass of the heat-resistant resin layer) is preferably 20% by mass or more, more preferably 30% by mass or more, and preferably 70% by mass or less. , more preferably 60% by mass or less. When the content of the silicone resin is equal to or higher than the lower limit, the heat resistance, solvent resistance, adhesion, and mechanical strength of the heat-resistant resin layer 3 can be further improved. When the content of the silicone resin is below the upper limit, the mechanical strength of the heat-resistant resin layer 3 can be further increased.

<Pigment>
In the following explanation, the common composition of the pigment used in the heat-resistant resin layer or each layer of the heat-resistant resin layer is simply referred to as "pigment", and the individual composition of the pigment used in the first layer 4 and the second layer 5 is referred to as "pigment". Regarding the composition, it will be referred to as "the pigment in the first layer 4" and "the pigment in the second layer 5." The same applies to the description of the acicular crystal pigment and the second pigment.

The heat-resistant resin layer 3 contains pigment. The first layer 4 contains pigment. The pigment in the first layer 4 includes an acicular crystal pigment and a second pigment. That is, the first layer 4 includes an acicular crystal pigment and a second pigment. The second pigment is a pigment other than the acicular crystal pigment. It is preferable that the second layer 5 contains a pigment. The second layer 5 may or may not contain an acicular crystal pigment. The second layer 5 may or may not contain pigments other than the acicular crystal pigment. However, it is preferable that the second layer 5 includes an acicular crystal pigment and a pigment other than the acicular crystal pigment (second pigment). Note that the pigments contained in each layer of the heat-resistant resin layer 3 may be the same or different.

Acicular crystal pigment:
Acicular crystal pigments are pigments that have a needle shape. Whether the pigment is acicular or not can be confirmed by observing its shape using a scanning electron microscope, a transmission electron microscope, or the like. Only one kind of the above-mentioned needle-like crystal pigment may be used, or two or more kinds thereof may be used in combination.

The content of the acicular crystal pigment in 100% by mass of the pigment in the first layer 4 is 30% by mass or more and 70% by mass or less, preferably 31% by mass or more, more preferably 33% by mass or more. , preferably 60% by mass or less, more preferably 50% by mass or less. When the content of the acicular crystal pigment is at least the above lower limit and below the above upper limit, the acicular crystal pigments intertwine well with each other in the first layer 4 to function as an aggregate, and the top plate 1 is heated to a high temperature. Even when the first layer 4 is cooled rapidly due to the difference in temperature, thermal contraction of the first layer 4 can be suppressed. Therefore, the thermal shock resistance of the top plate 1 can be improved, and it is possible to prevent the heat-resistant resin layer 3 from peeling off from the glass substrate 2 or from generating cracks or cracks in the heat-resistant resin layer 3. Furthermore, since a relatively large amount of colored pigment can be included as the second pigment in the first layer 4, the appearance of the top plate 1 can be easily adjusted to a desired color tone.

The content of the acicular crystal pigment in 100% by mass of the pigment in the second layer 5 is preferably 10% by mass or more, more preferably 15% by mass or more, preferably 70% by mass or less, and more preferably 50% by mass or more. It is not more than 40% by mass, more preferably not more than 40% by mass. When the content of the acicular crystal pigment is at least the above lower limit and below the above upper limit, the acicular crystal pigments intertwine well with each other in the second layer 5 to function as an aggregate, and the top plate 1 is heated to a high temperature. Even if the second layer 5 is cooled rapidly due to the difference, thermal contraction of the second layer 5 can be suppressed. Therefore, the thermal shock resistance of the top plate 1 can be improved, and it is possible to prevent the heat-resistant resin layer 3 from peeling off or from being cracked or cracked. Furthermore, since a relatively large amount of colored pigment can be included as the second pigment in the second layer 5, the appearance of the top plate 1 can be easily adjusted to a desired color tone.

The average length of the acicular crystal pigment is preferably 5 μm or more, more preferably 8 μm or more, preferably 60 μm or less, and more preferably 40 μm or less. If the average length of the acicular crystal pigments is smaller than the above lower limit, the acicular crystal pigments will not be able to intertwine well with each other, and when the top plate 1 is rapidly cooled due to a large temperature difference, the first layer 4 And it becomes difficult to suppress thermal contraction of the second layer 5. Therefore, it becomes difficult to improve the thermal shock resistance of the top plate 1. On the other hand, if the average length of the acicular crystal pigment is larger than the above upper limit, it becomes difficult to obtain the desired appearance and the applicability decreases.

The average diameter of the acicular crystal pigment is preferably 0.1 μm or more, more preferably 0.2 μm or more, preferably 7 μm or less, and more preferably 5 μm or less. If the average diameter of the acicular crystal pigment is smaller than the above lower limit, the acicular crystal pigment will easily break during the process of producing the first layer-forming paste or the second layer-forming paste, and as a result, the acicular crystal pigment will break. When the crystal pigments cannot intertwine well with each other and the top plate 1 is rapidly cooled due to a large temperature difference, it becomes difficult to suppress thermal contraction of the first layer 4 or the second layer 5. Therefore, it becomes difficult to improve the thermal shock resistance of the top plate 1. Furthermore, if the average diameter of the acicular crystal pigments is larger than the above upper limit, the acicular crystal pigments cannot be entwined well with each other, making it difficult to improve the thermal shock resistance of the top plate 1 as described above.

The average aspect ratio of the acicular crystal pigment is preferably 8 or more, more preferably 10 or more, preferably 100 or less, and more preferably 80 or less. If the average aspect ratio of the acicular crystal pigments is smaller than the above lower limit, the acicular crystal pigments cannot intertwine well with each other, and when the top plate 1 is rapidly cooled due to a large temperature difference, the first layer 4 Alternatively, it becomes difficult to suppress thermal contraction of the second layer 5. Therefore, it becomes difficult to improve the thermal shock resistance of the top plate 1. Furthermore, if the average aspect ratio of the acicular crystal pigment is larger than the above upper limit, it becomes difficult to obtain the desired appearance, the applicability tends to decrease, and the paste for forming the first layer or the second layer becomes difficult to obtain. In the manufacturing process, the acicular crystal pigment tends to break, making it difficult to improve the thermal shock resistance of the top plate 1 as described above.

The average length and average diameter of the acicular crystal pigment can be determined by measuring the length and diameter of 50 arbitrary acicular crystal pigments using a scanning electron microscope and averaging them. Further, the average aspect ratio of the acicular crystal pigment means the ratio of the average length of the acicular crystal pigment to the average diameter (average length/average diameter).

The Mohs hardness of the acicular crystal pigment is preferably 2.5 or more, more preferably 3 or more, still more preferably 4 or more. When the Mohs hardness is equal to or higher than the lower limit, the scratch resistance of the heat-resistant resin layer 3 can be further improved.

Examples of the acicular crystal pigment include potassium titanate, calcium silicate, and titanium oxide.

The acicular crystal pigment in the first layer 4 preferably contains at least one selected from the group consisting of potassium titanate, calcium silicate, and titanium oxide, and more preferably contains potassium titanate. . In this case, the thermal shock resistance of the top plate 1 can be further improved.

The acicular crystal pigment in the second layer 5 preferably contains at least one selected from the group consisting of potassium titanate, calcium silicate, and titanium oxide, and more preferably contains potassium titanate. . In this case, the thermal shock resistance of the top plate 1 can be further improved.

Second pigment (pigment other than needle crystal pigment):
Examples of the second pigment include colored pigments and scaly pigments. Only one type of the second pigment may be used, or two or more types may be used in combination.

From the viewpoint of improving the design of the top plate 1, it is preferable that the second pigment in the first layer 4 contains a colored pigment. It is preferable that the first layer 4 contains the above-mentioned acicular crystal pigment and a colored pigment.

From the viewpoint of improving the design of the top plate 1 and the concealability of the inside of the cooking device, the second pigment in the second layer 5 preferably contains a colored pigment. It is preferable that the second layer 5 contains the above-mentioned acicular crystal pigment and a colored pigment.

When the first layer 4 and the second layer 5 each contain a colored pigment, the first layer 4 contains the first colored pigment, and the second layer 5 contains the first colored pigment. may include a different second colored pigment. In this case, an appropriate combination of coloring pigments can be selected in consideration of the design and the concealability of the interior of the cooker. As for the said coloring pigment, only 1 type may be used, and 2 or more types may be used together.

Examples of the colored pigments include spherical colored pigments.

The colored pigments include white pigment powders such as TiO ₂ powder, ZrO ₂ powder, and ZrSiO ₄ powder; blue inorganic pigment powder containing Co; green inorganic pigment powder containing Co; Ti-Sb-Cr-based and Ti -Ni-based yellow inorganic pigment powder; Co--Si-based red inorganic pigment powder; brown inorganic pigment powder containing Fe; black inorganic pigment powder containing Cu, etc.

Examples of the blue inorganic pigment powder containing Co include Co-Al-based and Co-Al-Ti-based inorganic pigment powders. Examples of the Co--Al based inorganic pigment powder include CoAl ₂ O ₄ powder and the like. Examples of the Co--Al--Ti based inorganic pigment powder include CoAl ₂ O ₄ --TiO ₂ --Li ₂ O powder.

Examples of the green inorganic pigment powder containing Co include Co-Al-Cr-based and Co-Ni-Ti-Zn-based inorganic pigment powders. Examples of the Co--Al--Cr based inorganic pigment powder include Co(Al, Cr) ₂ O ₄ powder and the like. Examples of the Co--Ni--Ti--Zn based inorganic pigment powder include (Co, Ni, Zn) ₂ TiO ₄ powder and the like.

Examples of the brown inorganic pigment powder containing Fe include Fe--Zn-based inorganic pigment powder. Examples of the Fe--Zn-based inorganic pigment powder include (Zn, Fe) Fe ₂ O ₄ powder and the like.

Examples of the black inorganic pigment powder containing Cu include Cu-Cr-based inorganic pigment powder and Cu-Fe-based inorganic pigment powder. Examples of the Cu-Cr-based inorganic pigment powder include Cu(Cr,Mn) ₂ O ₄ powder and Cu-Cr-Mn powder. Examples of the Cu-Fe-based inorganic pigment powder include Cu-Fe-Mn powder.

Out of 100% by mass of the pigment in the first layer 4, the content of the colored pigment is preferably 10% by mass or more, more preferably 15% by mass or more, still more preferably 20% by mass or more, and preferably 60% by mass or less. , more preferably 50% by mass or less, still more preferably 40% by mass or less. The effect of the present invention can be further enhanced when the content of the colored pigment is not less than the above lower limit and not more than the above upper limit. In particular, when the colored pigment is a black inorganic pigment powder, the top plate 1 can have a desired black appearance.

Out of 100% by mass of the pigment in the second layer 5, the content of the colored pigment is preferably 10% by mass or more, more preferably 15% by mass or more, still more preferably 20% by mass or more, and preferably 60% by mass or less. , more preferably 50% by mass or less, still more preferably 40% by mass or less. The effect of the present invention can be further enhanced when the content of the colored pigment is not less than the above lower limit and not more than the above upper limit. In particular, when the colored pigment is a black inorganic pigment powder, the top plate 1 can have a desired black appearance.

From the viewpoint of easily giving the top plate 1 a black appearance, at least one of the coloring pigment in the first layer 4 and the coloring pigment in the second layer 5 is a black inorganic material containing Cu. Preferably, it contains pigment powder. At least one of the first layer 4 and the second layer 5 preferably contains black inorganic pigment powder containing Cu. In this case, the top plate 1 can have a desired black appearance with a relatively small content of colored pigment. Therefore, the first layer 4 or the second layer 5 can contain a relatively large amount of acicular crystal pigment, making it easier to realize the top plate 1 having a black appearance and high thermal shock resistance.

From the viewpoint of improving the mechanical strength of the top plate 1, at least one of the colored pigment in the first layer 4 and the colored pigment in the second layer 5 is composed of scales as the second pigment. It is preferable that the pigment contains a type pigment, and it is more preferable that it contains talc. At least one of the second pigment in the first layer 4 and the second pigment in the second layer 5 preferably contains a scaly pigment, and more preferably contains talc. In particular, when the second pigment contains talc, the mechanical strength of the top plate 1 can be improved at relatively low cost.

Other details of pigment:
The content of the pigment in the first layer 4 (the content of the pigment in 100% by mass of the first layer) is 51% by mass or more and less than 72% by mass, preferably 53% by mass or more, more preferably is 54% by mass or more, more preferably 55% by mass or more, preferably 71% by mass or less, more preferably 70% by mass or less, even more preferably 68% by mass or less, even more preferably 65% by mass or less, even more preferably is 63% by mass or less, particularly preferably 60% by mass or less. When the content of the pigment is more than the lower limit and less than the upper limit, the thermal shrinkage rate of the first layer 4 can be reduced even when the top plate 1 is rapidly cooled with a large temperature difference from a high temperature to a low temperature. Can be done. Therefore, the thermal shock resistance of the top plate 1 can be improved, and it is possible to prevent the heat-resistant resin layer 3 from peeling off from the glass substrate 2 or from generating cracks or cracks in the heat-resistant resin layer 3. Furthermore, when the content of the pigment is below the upper limit, the adhesion between the first layer 4 and the glass substrate 2 is effectively increased, and the effects of the present invention are effectively exhibited. Note that if the content of the pigment in the first layer 4 is 72% by mass or more, the adhesion between the first layer 4 and the glass substrate 2 may decrease, making it impossible to form a continuous film. be.

The content of the pigment in the second layer 5 (the content of the pigment in 100% by mass of the second layer) is preferably 30% by mass or more, more preferably 40% by mass or more, and preferably less than 72% by mass. , more preferably 71% by mass or less, still more preferably 70% by mass or less, particularly preferably 60% by mass or less. When the content of the pigment is at least the above lower limit and below the above upper limit (or less than the above upper limit), it becomes easier to impart a desired color tone to the second layer 5, and the strength of the heat-resistant resin layer 3 can be increased. can.

<Other details of the heat-resistant resin layer>
The first layer 4 and the second layer 5 may each contain other components different from both the silicone resin and the pigment.

The composition of the first layer 4 and the composition of the second layer 5 may be the same or different. The thickness of the first layer 4 and the second layer 5 is preferably 5 μm or more, more preferably 8 μm or more, preferably 50 μm or less, and more preferably 30 μm or less. If the thickness of each layer is smaller than the above lower limit, it will be difficult to improve the design and the concealability of the interior of the cooker. On the other hand, if the thickness of each layer is larger than the above upper limit, the amount of evaporation of the organic solvent from each layer increases during the drying or baking process, increasing the number of voids in each layer, and as a result, the top plate 1 is exposed to a large temperature difference. Thermal shrinkage increases when rapidly cooled. Therefore, it becomes difficult to improve the thermal shock resistance of the top plate 1.

Further, the overall thickness of the heat-resistant resin layer 3 (the total thickness of the first layer 4 and the second layer 5) is not particularly limited, and is preferably 5 μm or more, more preferably 10 μm or more, preferably 70 μm or less, and more. Preferably it is 30 μm or less. When the overall thickness of the heat-resistant resin layer 3 is within the above range, it is possible to effectively prevent the heat-resistant resin layer 3 from peeling off from the glass substrate 2 due to repeated heating and cooling, and also improve the design and concealment of the inside of the cooker. performance can be further improved.

When black is desired as the appearance of the top plate 1, the L ^* value of the top plate 1 in the L ^* a ^* b ^* color system when measured from the glass substrate 2 side (cooking surface side) is preferably 35 or less. , more preferably 33.5 or less, still more preferably 32 or less.

The above L ^* value can be measured at 25° C. using a color difference meter (for example, “CM600d” manufactured by Konica Minolta).

Hereinafter, an example of a method for manufacturing the top plate 1 for a cooker will be described.

(Production method)
In an example of a method for manufacturing the top plate 1 for a cooker, first, a paste containing a silicone resin component and a pigment is prepared. The silicone resin described above can be obtained by curing a silicone resin component. The silicone resin component may contain a silicone resin, a monomer, or a silicone oligomer. By including a monomer or a silicone oligomer as the silicone resin component, the number of reaction points for the crosslinking reaction between the silicone resin components increases, the reaction is accelerated, and the mechanical strength of the heat-resistant resin layer 3 is easily increased. As a result, the scratch resistance is easily improved, and scratches are less likely to occur during the transportation process when the top plate 1 is assembled into a cooking appliance, or when it comes into contact with peripheral parts. The paste may also contain other components such as a curing catalyst, a crosslinking agent, a solvent, a viscosity modifier, a leveling agent, and an antifoaming agent. In this embodiment, a first layer-forming paste and a second layer-forming paste are prepared separately. Note that the solvent is not particularly limited, and for example, xylene can be used.

Next, a first layer forming paste is applied onto the back surface 2b of the glass substrate 2. Next, by heating the glass substrate 2 coated with the first layer forming paste, the first layer forming paste is dried and the silicone resin component is cured to form the first layer 4. . Note that depending on the composition of the first layer 4, baking may be further performed after drying.

Next, a second layer forming paste is applied onto the first layer 4. Next, by heating the glass substrate 2 on which the second layer forming paste is applied on the first layer 4, the second layer forming paste is dried, the silicone resin component is cured, and the second layer forming paste is cured. 2 layer 5 is formed. Thereby, the heat-resistant resin layer 3 can be formed. Note that depending on the composition of the second layer 5, baking may be further performed after drying.

The application speed and viscosity of the paste can be appropriately set depending on the content of pigment contained in the heat-resistant resin layer 3. For example, when the content of pigment in the heat-resistant resin layer 3 is large, it is preferable to increase the amount of solvent to lower the viscosity of the silicone resin component and slow down the paste application speed.

The drying temperature of the paste can be, for example, 60°C or higher and 200°C or lower. The drying time of the paste can be, for example, 1 minute or more and 30 minutes or less.

Further, the firing temperature can be, for example, 200°C or higher and 450°C or lower. The firing time can be, for example, 10 minutes or more and 1 hour or less.

Note that before drying or baking the first layer-forming paste, a second layer-forming paste is applied on top of the first layer-forming paste, and the two layers are dried or baked at the same time. Good too.

[Second embodiment]
FIG. 2 is a schematic cross-sectional view showing a top plate for a cooker according to a second embodiment of the present invention.

The cooker top plate 1A shown in FIG. 2 includes a glass substrate 2 and a heat-resistant resin layer 3A. The top plate 1A shown in FIG. 2 and the top plate 1 shown in FIG. 1 have different configurations of the heat-resistant resin layer. That is, the top plate 1 shown in FIG. 1 is provided with a heat-resistant resin layer 3 having a two-layer structure, whereas the top plate 1A shown in FIG. 2 is provided with a heat-resistant resin layer 3A having a one-layer structure. is provided.

The heat-resistant resin layer 3A is arranged on the back surface 2b of the glass substrate 2. The heat-resistant resin layer 3A has a single layer structure including only the first layer 4A. Therefore, the heat-resistant resin layer 3A is the first layer 4A. The heat-resistant resin layer 3A (first layer 4A) is in contact with the back surface 2b of the glass substrate 2.

The first layer 4A includes a silicone resin and a pigment.

The pigment in the first layer 4A includes an acicular crystal pigment and a second pigment. The content of the pigment in the first layer 4A (the content of the pigment in 100% by mass of the first layer) is 51% by mass or more and less than 72% by mass. The content of the acicular crystal pigment in 100% by mass of the pigment in the first layer 4A is 30% by mass or more and 70% by mass or less.

Since the top plate 1A has the above configuration, it has excellent thermal shock resistance. In the top plate 1A, even when the top plate 1A is rapidly cooled due to a large temperature difference, the heat-resistant resin layer 3A (first layer 4A) is unlikely to peel off from the glass substrate 2. Moreover, cracks and cracks are less likely to occur in the heat-resistant resin layer 3A.

Note that the first layer 4A may contain a colored pigment or the like as the second pigment, similarly to the first embodiment.

Details of the glass substrate 2, silicone resin, pigments (acicular crystal pigment and second pigment), and other components are the same as described in the first embodiment, so descriptions thereof will be omitted. In addition, preferable ranges of each content of silicone resin and pigment (acicular crystal pigment and second pigment) in the heat-resistant resin layer 3A and the first layer 4A, etc. The form is similar to the preferable form of the heat-resistant resin layer 3 and the first layer 4 described in the first embodiment. Furthermore, a preferable form of the L ^* value in the L ^* a ^* b ^* color system of the top plate 1A when measured from the glass substrate 2 side (cooking surface 2a side) is the top plate 1 explained in the first embodiment. The details are the same as the details of the preferred form of the L ^* value in the L ^* a ^* b ^* color system.

The thickness of the heat-resistant resin layer 3A (thickness of the first layer 4A) is not particularly limited, and is preferably 5 μm or more, more preferably 10 μm or more, preferably 70 μm or less, and more preferably 50 μm or less. If the thickness of the heat-resistant resin layer 3A is smaller than the above-mentioned lower limit, it will be difficult to improve the design and the concealability of the inside of the cooking device. On the other hand, if the thickness of the heat-resistant resin layer 3A is larger than the above upper limit, the amount of evaporation of the organic solvent from the heat-resistant resin layer 3A increases during the drying or baking process, resulting in an increase in voids in the heat-resistant resin layer 3A. , thermal contraction becomes large when the top plate 1A is rapidly cooled due to a large temperature difference. Therefore, it becomes difficult to improve the thermal shock resistance of the top plate 1A.

The method for forming the heat-resistant resin layer 3A is also not particularly limited, and can be formed by the same method as in the first embodiment. Specifically, first, a paste containing a silicone resin component and a pigment is prepared. The paste may contain other components such as a curing catalyst, a crosslinking agent, a solvent, a viscosity modifier, a leveling agent, and an antifoaming agent. Next, the prepared paste is applied onto the back surface 2b of the glass substrate 2. Subsequently, the paste is dried by heating the glass substrate 2 coated with the paste, and the silicone resin component is cured to form the heat-resistant resin layer 3A. Note that depending on the composition of the heat-resistant resin layer 3A, baking may be performed after drying.

[Third embodiment]
FIG. 3 is a schematic cross-sectional view showing a top plate for a cooker according to a third embodiment of the present invention.

A top plate 1B for a cooking appliance shown in FIG. 3 includes a glass substrate 2, a heat-resistant resin layer 3B, and an inorganic layer 7B. The top plate 1B shown in FIG. 3 and the top plate 1 shown in FIG. 1 differ in the presence or absence of an inorganic layer.

The inorganic layer 7B is arranged on the back surface 2b of the glass substrate 2. The inorganic layer 7B is partially arranged on the back surface 2b of the glass substrate 2. That is, the back surface 2b of the glass substrate 2 has a portion where the inorganic layer 7B is placed and a portion where the inorganic layer 7B is not placed. The inorganic layer 7B is arranged in a dot shape on the back surface 2b of the glass substrate 2. The heat-resistant resin layer 3B is arranged on the back surface 2b of the glass substrate 2. The heat-resistant resin layer 3B is arranged on the back surface 2b of the glass substrate 2 so as to cover the inorganic layer 7B. Therefore, the inorganic layer 7B is arranged between the glass substrate 2 and the heat-resistant resin layer 3B.

The heat-resistant resin layer 3B includes a first layer 4B and a second layer 5B. The first layer 4B is arranged on the back surface 2b of the glass substrate 2 and the front surface of the inorganic layer 7B, and the second layer 5B is arranged on the first layer 4B. The first layer 4B is in contact with the back surface 2b of the glass substrate 2. The first layer 4B is in contact with the back surface 2b of the glass substrate 2 at a portion of the back surface 2b of the glass substrate 2 where the inorganic layer 7B is not disposed. Further, the first layer 4B is in contact with the inorganic layer 7B. The first layer 4B is arranged on the back surface 2b of the glass substrate 2 so as to cover the inorganic layer 7B. The first layer 4B is located on the glass substrate 2 side in the heat-resistant resin layer 3B. The second layer 5B is located on the opposite side to the glass substrate 2 side in the heat-resistant resin layer 3B.

The first layer 4B includes silicone resin and pigment. Further, the second layer 5B includes a silicone resin and a pigment.

The pigment in the first layer 4B includes an acicular crystal pigment and a second pigment. The content of the pigment in the first layer 4B (the content of the pigment in 100% by mass of the first layer) is 51% by mass or more and less than 72% by mass. The content of the acicular crystal pigment in 100% by mass of the pigment in the first layer 4B is 30% by mass or more and 70% by mass or less.

Since the top plate 1B has the above configuration, it has excellent thermal shock resistance. In the top plate 1B, even when the top plate 1B is rapidly cooled due to a large temperature difference, peeling does not easily occur between the glass substrate 2 and the heat-resistant resin layer 3B (first layer 4B), and the heat-resistant resin layer 3B covers the top plate 1B. Peeling is unlikely to occur between the inorganic layer 7B and the heat-resistant resin layer 3B (first layer 4B) that are coated. Moreover, cracks and cracks are less likely to occur in the heat-resistant resin layer 3B.

Note that the first layer 4B may contain a colored pigment or the like as the second pigment, similarly to the first embodiment. Further, the second layer 5B may contain, as a pigment, an acicular crystal pigment, a pigment other than the acicular crystal pigment, and a acicular crystal pigment and a pigment other than the acicular crystal pigment ( (second pigment).

Details of the glass substrate 2, silicone resin, pigments (acicular crystal pigment and second pigment), and other components are the same as described in the first embodiment, so descriptions thereof will be omitted. In addition, the heat-resistant resin layer 3B, the preferable range of each content of the silicone resin and the pigment (acicular crystal pigment and second pigment) in the heat-resistant resin layer 3B, the first layer 4B, and the second layer 5B, etc. The preferred forms of the first layer 4B and the second layer 5B are the same as the preferable forms of the heat-resistant resin layer 3, the first layer 4, and the second layer 5 described in the first embodiment. Furthermore, a preferable form of the L ^* value in the L ^* a ^* b ^* color system of the top plate 1B when measured from the glass substrate 2 side (cooking surface 2a side) is the top plate 1 described in the first embodiment. The details are the same as the details of the preferred form of the L ^* value in the L ^* a ^* b ^* color system.

In this embodiment, the inorganic layer 7B is arranged in dots on the back surface 2b of the glass substrate 2 in order to enhance the design of the top plate 1B. In the top plate 1B, a dot-like pattern originating from the inorganic layer 7B is observed in a plan view viewed from the cooking surface 2a side of the glass substrate 2. However, the shape of the inorganic layer 7B partially disposed on the back surface 2b of the glass substrate 2 may be a shape other than a dot shape, for example, a linear shape when viewed from the cooking surface 2a side of the glass substrate 2. It may be in the shape of a straight line, a broken line, a wavy line, etc., or it may be in the shape of a character, a symbol, or the like. The position and shape of the inorganic layer 7B partially arranged on the back surface 2b of the glass substrate 2 can be selected as appropriate from the viewpoint of design when the top plate 1B is viewed from the cooking surface 2a side of the glass substrate 2. It is.

The inorganic layer 7B is a layer containing an inorganic substance. The inorganic layer 7B is, for example, a layer containing glass and pigment. It is preferable that the inorganic layer 7B is a layer containing glass and a colored pigment. In this case, as the colored pigment in the inorganic layer 7B, for example, the above-mentioned colored pigment can be used. Further, as the glass in the inorganic layer 7B, for example, B ₂ O ₃ -SiO ₂ -based glass can be used.

Note that the inorganic layer 7B may be a metal layer such as titanium.

The thickness of the inorganic layer 7B is not particularly limited. The thickness of the inorganic layer 7B can be appropriately set depending on, for example, the light transmittance, mechanical strength, or thermal expansion coefficient of the inorganic layer 7B. Note that the inorganic layer 7B usually has a different coefficient of thermal expansion than the glass substrate 2. Therefore, the inorganic layer 7B may be damaged due to repeated heating and cooling.

From the viewpoint of further suppressing this damage, the thickness of the inorganic layer 7B is preferably thinner. The thickness of the inorganic layer 7B is preferably 1 μm or more, more preferably 2 μm or more, preferably 20 μm or less, and more preferably 15 μm or less.

The method for manufacturing the top plate 1B is also not particularly limited, and can be manufactured by the same method as in the first embodiment except for forming the inorganic layer 7B.

The method of forming the inorganic layer 7B is not particularly limited. The inorganic layer 7B can be formed, for example, by the method described below.

First, a solvent is added to a mixed powder of colored pigment and glass powder to form a paste. The obtained paste is applied onto the back surface 2b of the glass substrate 2 by a screen printing method or the like and dried. Thereafter, the inorganic layer 7B can be formed by firing. Note that the firing temperature and firing time can be appropriately set depending on the composition of the glass powder used. The firing temperature can be, for example, about 200°C to 900°C. The firing time can be, for example, about 10 minutes to 1 hour.

Note that when the inorganic layer 7B is a metal layer, the inorganic layer 7B can be formed by a sputtering method, a CVD method, or the like.

In the present embodiment, the top plate 1B includes the heat-resistant resin layer 3B having a two-layer structure; however, the top plate 1B may include a heat-resistant resin layer having a one-layer structure, or may have a three-layer or more structure. The heat-resistant resin layer may also include a heat-resistant resin layer having the following properties.

As shown in the embodiments described above, in the present invention, the heat-resistant resin layer may have a structure of one layer, two or more layers, or three or more layers. When the heat-resistant resin layer has a one-layer structure, the heat-resistant resin layer is the first layer. When the heat-resistant resin layer has a structure of two or more layers, the first layer of the heat-resistant resin layer is usually located on the glass substrate side in the heat-resistant resin layer.

In the present invention, the first layer of the heat-resistant resin layer has a portion that is in direct contact with the back surface of the glass substrate. In the present invention, as shown in the first and second embodiments, the entire surface of the first layer on the glass substrate side may be in contact with the back surface of the glass substrate, and the third layer may be in contact with the back surface of the glass substrate. As shown in the embodiment, a part of the surface of the first layer on the glass substrate side may be in contact with the back surface of the glass substrate.

Hereinafter, the present invention will be described in further detail based on Examples. However, the following examples are merely illustrative. The present invention is not limited to the following examples.

The following glass substrates were prepared.

Transparent crystallized glass plate (“N-0” manufactured by Nippon Electric Glass Co., Ltd., average linear thermal expansion coefficient at 30°C to 750°C: 0.5 × 10 ^-7 /°C, thickness: 4 mm)

The following materials for the heat-resistant resin layer were prepared.

<Silicone resin component>
Methylphenyl silicone resin (“TSR-145” manufactured by Momentive, this commercial product is a mixture of a solvent (xylene and toluene) and a silicone resin, and contains 60% by mass of silicone resin and 40% by mass of solvent)
Modified methylphenyl silicone resin Polyfunctional silicone oligomer

<Acicular crystal pigment>
Potassium titanate (Mohs hardness 4, “Tismo D” manufactured by Otsuka Chemical Co., Ltd.)

<Second pigment>
Talc (Mohs hardness 1, scaly pigment)
Black pigment (spherical pigment)

<Solvent>
xylene

<Preparation of pastes X1 to X3, Y1 to Y4>
Pastes X1 to X3 and Y1 to Y4 were prepared by mixing the components listed in Tables 1 and 2 below. The content of each component in 100% by mass of the components excluding the solvent in each paste is shown in Tables 1 and 2 below.

(Example 1)
Paste X1 was used as the first layer-forming paste in the heat-resistant resin layer, and paste X1 was used as the second layer-forming paste. The first layer-forming paste was screen printed on the back surface of the glass substrate to a thickness of 15 μm. Next, heat drying was performed at 300° C. for 10 minutes to form a first layer. Next, the second layer forming paste was screen printed on the surface of the first layer to a thickness of 15 μm. Next, heat drying was performed at 300° C. for 10 minutes to form a second layer. In this way, a top plate (top plate for cooker) having a two-layer heat-resistant resin layer on the back surface of the glass substrate was produced.

(Examples 2 to 4 and Comparative Examples 1 to 5)
A top plate was produced in the same manner as in Example 1, except that the type of paste was changed as shown in Tables 3 and 4 below.

[evaluation]
(1) Thermal shock resistance of top plate The obtained top plate was placed in an oven and heated at 540° C. for 30 minutes. Next, the top plate was taken out of the oven, and the top plate was immediately put into water at a temperature of 10°C. The top plate was taken out 5 minutes after being placed in water, and the condition of the top plate was visually observed.

[Evaluation criteria]
A: The heat-resistant resin layer has not peeled off from the glass substrate, and there are no cracks or cracks in the heat-resistant resin layer. B: The heat-resistant resin layer has not peeled off from the glass substrate, but there are cracks or cracks in the heat-resistant resin layer. has occurred. C: Part of the heat-resistant resin layer has peeled off from the glass substrate. D: The entire heat-resistant resin layer has peeled off from the glass substrate.

(2) Appearance of top plate (L ^* value)
The L ^* value in the L ^* a ^* b ^* color system of the obtained top plate was evaluated from the cooking surface side of the glass substrate of the top plate using a color difference meter (“CM600d” manufactured by Konica Minolta).

Details and results are shown in Tables 3 and 4 below.

As is clear from Tables 3 and 4, in Examples 1 to 4 that satisfy the configuration of the present invention, in which pastes X1 to X3 (Table 1) were used for the first layer, the heat-resistant resin layer did not peel off from the glass substrate. In addition, there were no cracks or cracks in the heat-resistant resin layer, indicating that the thermal shock resistance was effectively improved. On the other hand, in Comparative Examples 1 to 5, which did not satisfy the constitution of the present invention, in which pastes Y1 to Y4 (Table 2) were used for the first layer, the thermal shock resistance was not sufficiently enhanced.

1, 1A, 1B... Top plate for cooker 2... Glass substrate 2a... Cooking surface 2b... Back surface 3, 3A, 3B... Heat resistant resin layer 4, 4A, 4B... First layer 5, 5B... Second layer 7B... inorganic layer

Claims (8)

a glass substrate having a cooking surface on which a cooking utensil is placed and a back surface opposite to the cooking surface;
a heat-resistant resin layer disposed on the back surface of the glass substrate;
Equipped with
The heat-resistant resin layer has a first layer containing a silicone resin and a pigment,
the first layer is in contact with the back surface of the glass substrate,
The pigment in the first layer includes an acicular crystal pigment and a second pigment,
The content of the pigment in 100% by mass of the first layer is 51% by mass or more and less than 72% by mass,
A top plate for a cooker, wherein the content of the acicular crystal pigment in 100% by mass of the pigment in the first layer is 30% by mass or more and 70% by mass or less. The top plate for a cooker according to claim 1, wherein the silicone resin in the first layer has a siloxane bond content of 40% by mass or more. The top plate for a cooker according to claim 1 or 2, wherein the acicular crystal pigment in the first layer contains at least one selected from the group consisting of potassium titanate, calcium silicate, and titanium oxide. . The top plate for a cooker according to claim 1 or 2, wherein the acicular crystal pigment in the first layer includes potassium titanate. The cooker top plate according to claim 1 or 2, wherein the second pigment in the first layer comprises a colored pigment. The top plate for a cooker according to claim 1 or 2, wherein the heat-resistant resin layer has a single layer structure including only the first layer. The heat-resistant resin layer is
the first layer;
a second layer containing a silicone resin and a pigment;
has
The top plate for a cooker according to claim 1 or 2, wherein the second layer is located on a side opposite to the glass substrate side in the heat-resistant resin layer. further comprising an inorganic layer disposed between the glass substrate and the heat-resistant resin layer,
The top plate for a cooker according to claim 1 or 2, wherein the inorganic layer contains glass and a pigment.

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