Cooker top plate and manufacturing method for cooker top plate

Abstract

Provided is a cooker top plate with which it is possible to obtain excellent heat resistance and coating film hardness while maintaining proper light transmittance of a transmissive part for transmitting light from a light source.　A cooker top plate 1 has a transmissive part D1 for transmitting light from a light source 10. The cooker top plate 1 comprises: a glass substrate 2 having a cooking surface 2a on which a cooking instrument is placed and a rear surface 2b on the side opposite from the cooking surface 2a; and a light semi-transmissive layer 3 disposed on the rear surface 2b side of the glass substrate 2. The light semi-transmissive layer 3 is provided to the transmissive part D1, and the light semi-transmissive layer 3 includes a silicone resin, a colored pigment, and transparent fine particles.

Description

Top plate for cooker and method for manufacturing the top plate for cooker

[0001] The present invention relates to a top plate for a cooker and a method for manufacturing a top plate for a cooker.

[0002] Cooking appliances equipped with a top plate for a cooking appliance and a light source such as an LED (Light Emitting Diode) are widely used. The cooking appliance top plate used in combination with the light source generally has a transmissive portion that transmits light from the light source and a non-transmissive portion that blocks the light from the light source. A user of the cooking appliance can visually recognize luminous signs (various information), such as the power on / off status and heating status, by the light from the light source that has transmitted through the transmissive portion.

[0003] Patent Document 1 below discloses a top plate for a cooking appliance that includes a glass substrate having a cooking surface on which a cooking utensil is placed and a back surface opposite the cooking surface, and that is provided with a transmissive portion that transmits light from a light source and a non-transmissive portion that blocks light from the light source. In this cooking appliance top plate, the transmissive portion has a first colored layer provided on the back surface of the glass substrate, and the non-transmissive portion has a light-blocking layer provided on the back surface of the glass substrate. Patent Document 1 also discloses that the first colored layer provided on the transmissive portion may contain a silicone resin and a color pigment.

[0004] Japanese Patent Application Laid-Open No. 2020-186905

[0005] As in Patent Document 1, a resin layer containing a silicone resin and a coloring pigment is sometimes disposed on the rear surface of a glass substrate in the transmissive portion of a top plate for a cooking appliance. The light transmittance of the resin layer can be adjusted, for example, by adjusting the content of the coloring pigment in the resin layer so that the inside of the cooking appliance is difficult to see through the transmissive portion when the light source is off, and light from the light source can be transmitted through the transmissive portion when the light source is on.

[0006] However, in the transparent portion, the conventional resin layer containing a silicone resin and a coloring pigment has a high content of silicone resin, and therefore the heat resistance and coating hardness of the resin layer cannot be sufficiently improved. That is, when the coloring pigment is increased in order to improve the heat resistance and coating hardness of the resin layer, the light transmittance of the resin layer decreases, and it is therefore difficult to obtain excellent heat resistance and coating hardness while maintaining an appropriate light transmittance in the resin layer.

[0007] An object of the present invention is to provide a top plate for a cooker that has excellent heat resistance and coating hardness while maintaining appropriate light transmittance in a transmitting portion that transmits light from a light source, and a method for manufacturing the top plate for a cooker.

[0008] Hereinafter, various aspects of a top plate for a cooker and a method for manufacturing a top plate for a cooker that solves the above problems will be described.

[0009] A top plate for a cooker according to aspect 1 of the present invention is a top plate for a cooker having a transmissive portion that transmits light from a light source, and is characterized by comprising a glass substrate having a cooking surface on which a cooking utensil is placed and a back surface opposite the cooking surface, and a semi-transparent layer disposed on the back surface side of the glass substrate, the semi-transparent layer being provided in the transmissive portion, and the semi-transparent layer containing a silicone resin, a color pigment, and transparent microparticles.

[0010] In the top plate for a cooker according to Aspect 2, in Aspect 1, it is preferable that the transparent fine particles have an average particle size of 0.1 μm or less.

[0011] A top plate for a cooker according to Aspect 3 is the top plate for a cooker according to Aspect 1 or 2, wherein the transparent fine particles preferably contain barium sulfate.

[0012] A top plate for a cooker according to Aspect 4 is the same as Aspect 3, wherein the content of the barium sulfate is preferably 43% by mass or more and 60% by mass or less in 100% by mass of the semi-light-transmitting layer.

[0013] In the top plate for a cooker according to Aspect 5, in Aspect 3 or Aspect 4, it is preferable that the content ratio of the barium sulfate to the silicone resin (barium sulfate / silicone resin) is 0.9 or more and 2 or less in mass ratio.

[0014] In the top plate for a cooking appliance according to aspect 6, in any one of aspects 1 to 5, the top plate for a cooking appliance may further include a light-shielding layer having a non-transparent portion that blocks light from a light source, the light-shielding layer being disposed on the back surface side of the glass substrate and positioned so as to overlap the non-transparent portion in a planar view.

[0015] In the top plate for a cooker according to Aspect 7, in any one of Aspects 1 to 6, the top plate for a cooker is placed on a black board with the back surface side facing downward, and L measured from the cooking surface side in the transmission portion is ＊ a ＊ b ＊ L in color system ＊ Preferably, the value is 30 or less.

[0016] A manufacturing method of a top plate for a cooker according to aspect 8 of the present invention is a manufacturing method of a top plate for a cooker having a translucent portion that transmits light from a light source, and includes the steps of: preparing a glass substrate having a cooking surface on which a cooking utensil is placed and a back surface opposite the cooking surface; applying a paste for forming a semi-light-transmitting layer to a portion of the back surface of the glass substrate where the translucent portion will be formed; and firing the glass substrate to which the paste for forming the semi-light-transmitting layer has been applied, wherein the paste for forming the semi-light-transmitting layer contains a silicone resin, a color pigment, and transparent microparticles.

[0017] A ninth aspect of the present invention relates to the method for manufacturing a top plate for a cookware according to the eighth aspect, wherein the transparent fine particles contain barium sulfate.

[0018] According to the present invention, it is possible to provide a top plate for a cooker, which has excellent heat resistance and coating hardness while maintaining appropriate light transmittance in a transmissive portion that transmits light from a light source, and a method for manufacturing the top plate for a cooker.

[0019] Fig. 1 is a schematic cross-sectional view showing a top plate for a cooker according to a first embodiment of the present invention, and Fig. 2 is a schematic cross-sectional view showing a top plate for a cooker according to a second embodiment of the present invention.

[0020] Preferred embodiments of the present invention will be described below. However, the following embodiments are merely examples, and the present invention is not limited to the following embodiments. In addition, in each drawing, components having substantially the same functions may be referred to by the same reference numerals.

[0021] In this specification, the term "top plate for a cooking appliance" may be abbreviated to "top plate."

[0022] 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.

[0023] The cooker top plate 1 shown in Figure 1 includes a glass substrate 2. The glass substrate 2 has a cooking surface 2a and a back surface 2b. The cooking surface 2a and the back surface 2b are opposite each other. The cooking surface 2a is the surface on which cookware such as pots and frying pans are placed. The back surface 2b is the surface facing the light source and heating device inside the cooker. Therefore, the cooking surface 2a and the back surface 2b are opposite each other.

[0024] A semi-light-transmitting layer 3 is disposed on the rear surface 2b of the glass substrate 2. In this embodiment, the semi-light-transmitting layer 3 is in contact with the rear surface 2b of the glass substrate 2. The semi-light-transmitting layer 3 includes a silicone resin, a color pigment, and transparent fine particles. In this specification, the term "transparent fine particles" refers to fine particles that satisfy the following criteria: Specifically, when a 10 μm-thick thin film composed of 10% by mass of transparent fine particles and 90% by mass of silicone resin is obtained, the thin film exhibits a minimum light transmittance of 80% or more at wavelengths of 450 nm to 810 nm. The silicone resin may be a methylphenyl silicone resin with a weight-average molecular weight (Mw) of 5,000 to 8,000. Examples of such transparent fine particles include inorganic fine particles with an average particle diameter of 0.5 μm or less, and barium sulfate is preferably used as the inorganic fine particles. For example, when a 10 μm-thick thin film composed of 10 mass % barium sulfate having an average particle size of 0.01 μm and 90 mass % methylphenyl silicone resin having a weight-average molecular weight (Mw) of 7000 is formed on a glass substrate (transparent crystallized glass plate, manufactured by Nippon Electric Glass Co., Ltd., "N-0"), the light transmittance at wavelengths of 450 nm to 810 nm measured from the glass substrate side (the side opposite to the surface on which the thin film is formed) is 95%.

[0025] The light transmittance of the thin film can be measured using a spectrophotometer (manufactured by JASCO Corporation, model number "V-770"), and the weight average molecular weight (Mw) of the silicone resin herein can be measured using gel permeation chromatography (GPC).

[0026] Furthermore, a light-shielding layer 4 is disposed on the rear surface 2b side of the glass substrate 2. In this embodiment, the light-shielding layer 4 is in contact with the rear surface 2b of the glass substrate 2. Note that the top plate 1 does not necessarily need to have the light-shielding layer 4 disposed on the rear surface 2b of the glass substrate 2. In this case, instead of the light-shielding layer 4, a light-semitransmitting layer 3 may be disposed in a portion other than the transmissive portion D1.

[0027] A light source 10 is provided below the top plate 1. The light source 10 can be configured by, for example, an LED or a liquid crystal display device.

[0028] The top plate 1 has a transmissive portion D1 that transmits light from the light source 10 and a non-transmissive portion D2 that blocks light from the light source 10. The light semi-transmissive layer 3 is disposed in a region that overlaps with the transmissive portion D1 in a planar view. The light-shielding layer 4 is disposed in a region that overlaps with the non-transmissive portion D2 in a planar view.

[0029] Light from the light source 10 is emitted to the outside (e.g., above the top plate 1) through the transmissive portion D1 and is blocked through the non-transmissive portion D2. The transmissive portion D1 is, for example, a region where information is displayed by light from the light source 10 when the top plate 1 is viewed in a plan view. Examples of displayed information include information indicating the status of the cooker, such as information indicating that the power is on or information indicating that heating is in progress. In the top plate 1, for example, by changing the planar shape of the semi-light-transmitting layer 3, light corresponding to the planar shape of the semi-light-transmitting layer 3 can be emitted to the outside, thereby displaying letters, numbers, symbols, etc. Furthermore, letters, numbers, symbols, etc. can be displayed by transmitting patterned light through the transmissive portion D1. Alternatively, letters, numbers, symbols, etc. can be displayed by transmitting light from a liquid crystal display device through the transmissive portion D1. The non-transmissive portion D2 is the portion other than the transmissive portion D1 when the top plate 1 is viewed in a plan view. The non-transparent portion D2 is a portion that blocks light from the light source 10 and conceals the internal structure of the cooking appliance.

[0030] The top plate 1 has the above-described configuration, and therefore, can obtain excellent heat resistance and coating hardness while maintaining appropriate light transmittance of the transmission portion D1 that transmits light from the light source 10.

[0031] In the past, the resin layer provided in the transparent portion of the top plate sometimes failed to sufficiently enhance the heat resistance of the resin layer. One possible method for enhancing the heat resistance of the resin layer is to increase the content of a coloring pigment. However, increasing the content of the coloring pigment in the resin layer reduces the light transmittance of the resin layer, making it difficult to obtain excellent heat resistance and coating hardness while maintaining an appropriate light transmittance in the resin layer.

[0032] In contrast, in the top plate 1 of this embodiment, the semi-light-transmitting layer 3 (resin layer) contains a silicone resin, a color pigment, and transparent microparticles, so that even if the content of transparent microparticles is increased to improve the heat resistance and coating hardness of the semi-light-transmitting layer 3, the light transmittance of the semi-light-transmitting layer 3 is unlikely to decrease. Furthermore, by adjusting the content of the color pigment and transparent microparticles while increasing the content of transparent microparticles in the semi-light-transmitting layer 3, it is possible to adjust the light transmittance of the semi-light-transmitting layer 3 to an appropriate level. Therefore, the top plate 1 including such a semi-light-transmitting layer 3 can achieve excellent heat resistance and coating hardness while maintaining an appropriate light transmittance in the transmissive portion D1, and therefore can provide a top plate suited to the intended use.

[0033] The members and layers that make up the top plate 1 will be described in detail below.

[0034] (Glass Substrate) The glass substrate 2 is preferably a glass substrate that transmits at least a portion of light in the wavelength range of 450 nm to 810 nm. The glass substrate 2 is preferably a transparent glass substrate. The glass substrate 2 may be colored and transparent, but is preferably colorless and transparent from the viewpoint of further enhancing the aesthetic appearance of the top plate 1. In this specification, the term "transparent" in relation to the glass substrate 2 means that the light transmittance in the visible wavelength range of 450 nm to 810 nm is 80% or more.

[0035] 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 thermal expansion coefficient. Specifically, the softening temperature of the glass substrate 2 is preferably 700°C or higher, and more preferably 750°C or higher. The average linear thermal expansion coefficient of the glass substrate 2 at 30°C to 750°C is -10×10 －７ / ℃~+60×10 －７ / °C, and is preferably within the range of -10 × 10 －７ / ℃~+50×10 －７ / °C, and more preferably within the range of -10 × 10 －７ / ℃~+40×10 －７ / °C. Therefore, the glass substrate 2 is preferably made of glass with a high glass transition temperature and low expansion, such as crystallized glass. A specific example of low expansion crystallized glass is "N-0" manufactured by Nippon Electric Glass Co., Ltd., which is an LAS-based crystallized glass. Note that a borosilicate glass substrate or the like may also be used as the glass substrate 2.

[0036] There is no particular limitation on the thickness of the glass substrate 2. The thickness of the glass substrate 2 can be appropriately set depending on the light transmittance, etc. The thickness of the glass substrate 2 can be, for example, about 2 mm to 6 mm.

[0037] (Semi-Light-Transmitting Layer) The semi-light-transmitting layer 3 is disposed on the rear surface 2b side of the glass substrate 2. The semi-light-transmitting layer 3 is in contact with the rear surface 2b of the glass substrate 2. In the present invention, another layer may be disposed between the semi-light-transmitting layer 3 and the glass substrate 2.

[0038] The semi-light-transmitting layer 3 is a layer that can transmit a portion of the light from the light source 10. The semi-light-transmitting layer 3 is designed to transmit light when the light source 10 is turned on and to conceal the internal structure of the cooking appliance when the light source 10 is turned off. The light transmittance of the semi-light-transmitting layer 3 can be determined appropriately depending on the application of the top plate 1. For example, if information is displayed in the transmissive portion D1 using light from the light source 10, the semi-light-transmitting layer 3 provided in the transmissive portion D1 may be determined to have a light transmittance that is sufficient to allow the displayed information to be visible when the light source 10 is turned on. Furthermore, the semi-light-transmitting layer 3 provided in the transmissive portion D1 may be determined to have a light transmittance that is sufficient to conceal the internal structure of the cooking appliance when the light source 10 is turned off.

[0039] <Silicone Resin> The semi-light-transmitting layer 3 contains a silicone resin. As the silicone resin, a conventionally known silicone resin can be used. Only one type of silicone resin may be used, or two or more types may be used in combination.

[0040] From the viewpoint of further enhancing heat resistance, the silicone resin is preferably a silicone resin having a methyl group or a phenyl group as a functional group. In this case, the methyl group may be directly bonded to a silicon atom, the phenyl group may be directly bonded to a silicon atom, or the methyl group and the phenyl group may be directly bonded to the same silicon atom.

[0041] The weight-average molecular weight (Mw) of the silicone resin is preferably 1,000 or more, more preferably 2,000 or more, and preferably 500,000 or less, more preferably 100,000 or less, and even more preferably 10,000 or less. When the weight-average molecular weight (Mw) of the silicone resin is equal to or greater than the above-mentioned lower limit, the heat resistance of the semi-light-transmitting layer 3 can be further improved, and the curing reaction of the silicone resin is less likely to require a long time, which is preferable. When the weight-average molecular weight (Mw) of the silicone resin is equal to or less than the above-mentioned upper limit, the viscosity of the paint (paste for forming the semi-light-transmitting layer, described later) does not become too high, making the coating work easier.

[0042] The content of the silicone resin in the semi-light-transmitting layer 3 is preferably 20% by mass or more, more preferably 30% by mass or more, even more preferably 35% by mass or more, particularly preferably 40% by mass or more, and preferably 70% by mass or less, more preferably 60% by mass or less, even more preferably 55% by mass or less, particularly preferably 50% by mass or less. When the content of the silicone resin is equal to or greater than the above-mentioned lower limit, the light transmittance of the semi-light-transmitting layer 3 can be further increased. When the content of the silicone resin is equal to or less than the above-mentioned upper limit, the heat resistance and coating hardness of the semi-light-transmitting layer 3 can be further improved. The content of the silicone resin is the content when the total material contained in the semi-light-transmitting layer 3 is taken as 100% by mass.

[0043] <Transparent Fine Particles> The semi-light-transmitting layer 3 contains transparent fine particles. In this specification, the transparent fine particles are pigments different from color pigments and extender pigments. By using the transparent fine particles, it is possible to improve the light transmittance of the semi-light-transmitting layer 3 and the heat resistance of the top plate 1. Only one type of transparent fine particles may be used, or two or more types may be used in combination.

[0044] Examples of the transparent fine particles include barium sulfate and glass beads.

[0045] The transparent fine particles preferably contain barium sulfate, and more preferably are barium sulfate. Since barium sulfate is a colorless and transparent pigment, even if the content of barium sulfate in the semi-light-transmitting layer 3 is increased, the light transmittance of the semi-light-transmitting layer 3 is unlikely to decrease. Therefore, for example, when the light source 10 is turned off, the transmission portion D1 is set to L ＊ In addition, by increasing the content of barium sulfate in the semi-light-transmitting layer 3, the heat resistance and coating hardness of the top plate 1 can be further improved.

[0046] The average particle diameter of the transparent fine particles is preferably 0.5 μm or less, more preferably 0.1 μm or less, even more preferably 0.05 μm or less, and particularly preferably 0.03 μm or less. When the average particle diameter of the transparent fine particles is equal to or less than the upper limit, the light transmittance of the semi-light-transmitting layer 3 is unlikely to decrease even when the content of the transparent fine particles in the semi-light-transmitting layer 3 is increased. Therefore, for example, when the light source 10 is turned off, the light transmitting portion D1 is set to L ＊ The value is low, which facilitates achieving a highly jet-black appearance. Furthermore, by increasing the content of transparent fine particles in the semi-light-transmitting layer 3, the heat resistance and coating hardness of the top plate 1 can be further improved. The lower limit of the average particle diameter of the transparent fine particles is not particularly limited, but is, for example, 0.005 μm or more. In this case, sedimentation and separation of the transparent fine particles can be suppressed in the step of mixing the components in preparing the paste for forming the semi-light-transmitting layer, which will be described later, and productivity can be further improved.

[0047] The average particle size of the transparent fine particles is a median size derived from the volume distribution measured by a laser diffraction scattering method.

[0048] The content of the transparent fine particles in the semi-light-transmitting layer 3 is preferably 20% by mass or more, more preferably 35% by mass or more, even more preferably 43% by mass or more, particularly preferably 45% by mass or more, and is preferably 70% by mass or less, more preferably 65% ​​by mass or less, even more preferably 60% by mass or less, particularly preferably 58% by mass or less. When the content of the transparent fine particles is within the above range, the light transmittance of the transmissive portion D1 can be further increased, and the heat resistance and coating hardness of the top plate 1 can be further improved. Note that the content of the transparent fine particles is the content when the entire material contained in the semi-light-transmitting layer 3 is taken as 100% by mass.

[0049] When the transparent fine particles are barium sulfate, the content of barium sulfate in the semi-light-transmitting layer 3 is preferably 20% by mass or more, more preferably 35% by mass or more, even more preferably 43% by mass or more, particularly preferably 45% by mass or more, and preferably 70% by mass or less, more preferably 65% ​​by mass or less, even more preferably 60% by mass or less, particularly preferably 58% by mass or less. When the barium sulfate content is within the above range, the light transmittance of the transmissive portion D1 can be further increased, and the heat resistance and coating hardness of the top plate 1 can be further improved. Note that the barium sulfate content is the content when the total material contained in the semi-light-transmitting layer 3 is taken as 100% by mass.

[0050] <Coloring Pigment> The semi-light-transmitting layer 3 contains a coloring pigment. By using the coloring pigment, it is possible to adjust the light transmittance of the semi-light-transmitting layer 3 and further improve the design of the top plate 1. Only one type of coloring pigment may be used, or two or more types may be used in combination.

[0051] The color pigment is not particularly limited as long as it is a colored pigment. ２ Powder, ZrO ２ Powder and ZrSiO ４blue 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; and inorganic pigment powder having a pearlescent color.

[0052] Examples of blue inorganic pigment powders containing Co include Co-Al-based and Co-Al-Ti-based inorganic pigment powders. ２ O ４ Examples of Co-Al-Ti based inorganic pigment powders include CoAl ２ O ４ -TiO ２ -Li ２ O powder and the like.

[0053] Examples of green inorganic pigment powders containing Co include Co-Al-Cr and Co-Ni-Ti-Zn inorganic pigment powders. Examples of Co-Al-Cr inorganic pigment powders include Co(Al,Cr) ２ O ４ Examples of Co-Ni-Ti-Zn based inorganic pigment powders include (Co, Ni, Zn) ２ TiO ４ Examples include powder.

[0054] Examples of brown inorganic pigment powders containing Fe include Fe-Zn-based inorganic pigment powders. Examples of Fe-Zn-based inorganic pigment powders include (Zn, Fe)Fe ２ O ４ Examples include powder.

[0055] Examples of black inorganic pigment powders containing Cu include Cu—Cr-based inorganic pigment powders and Cu—Fe-based inorganic pigment powders. Examples of Cu—Cr-based inorganic pigment powders include Cu(Cr,Mn) ２ O ４ Examples of Cu-Fe inorganic pigment powders include Cu-Fe-Mn powders and Cu-Cr-Mn powders.

[0056] A pearlescent pigment may be used as the coloring pigment. Examples of pearlescent pigments that can be used include extender pigments whose surfaces are coated with metal oxides. Specifically, extender pigments such as mica, talc, kaolin, sericite, silicon oxide, calcium carbonate, and barium sulfate can be used as a base material, and the surface of the extender pigments can be coated with metal oxides such as titanium oxide, tin oxide, zirconium oxide, and iron oxide. Among these, it is preferable to use a pearlescent pigment whose surface is coated with titanium oxide and whose base material is natural mica. This can further improve the design of the top plate 1. These pearlescent pigments can be used alone or in combination.

[0057] The average particle size of the color pigment is preferably 0.01 μm or more, more preferably 0.05 μm or more, and preferably 5 μm or less, more preferably 1 μm or less. When the average particle size of the color pigment is within the above range, aggregation of the color pigment is suppressed, thereby more effectively suppressing color unevenness in the semi-light-transmitting layer 3 and making it less likely for the color pigment in the semi-light-transmitting layer 3 to protrude outward from the surface of the semi-light-transmitting layer 3. As a result, when assembling a cookware using the top plate 1 or when using the cookware after assembly, peeling of the semi-light-transmitting layer 3 due to peripheral parts, fingers, or the like getting caught on the surface of the semi-light-transmitting layer 3 can be suppressed.

[0058] The average particle size of the color pigment is a median size derived from a volume distribution measured by a laser diffraction scattering method.

[0059] The content of the color pigment in the semi-light-transmitting layer 3 is preferably 0.1% by mass or more, more preferably 1% by mass or more, and preferably 30% by mass or less, more preferably 20% by mass or less, even more preferably 15% by mass or less, and particularly preferably 12% by mass or less. When the content of the color pigment is within the above range, the desired light transmittance is easily obtained in the transmissive portion D1 of the top plate 1. Note that the content of the color pigment is the content when the entire material contained in the semi-light-transmitting layer 3 is taken as 100% by mass.

[0060] <Extender Pigment> The light semi-transmitting layer 3 may contain an extender pigment. In this specification, the extender pigment is a pigment that is different from transparent fine particles, colored pigments, and glass. By using the extender pigment, it is possible to adjust the light transmittance of the light semi-transmitting layer 3 and further improve the heat resistance and coating hardness of the top plate 1. Only one type of extender pigment may be used, or two or more types may be used in combination.

[0061] Examples of extender pigments include talc, mica, calcium carbonate, and zirconium oxide.

[0062] The average particle size of the extender pigment is preferably greater than 0.5 μm, more preferably at least 1 μm, even more preferably at least 3 μm, and is preferably no greater than 10 μm, more preferably no greater than 7 μm. When the average particle size of the extender pigment is within the above range, the heat resistance and coating hardness of the top plate 1 can be further improved.

[0063] The average particle size of the extender pigment is a median size derived from the volume distribution measured by a laser diffraction scattering method.

[0064] The content of the extender pigment in the semi-light-transmitting layer 3 is preferably 20% by mass or less, more preferably 10% by mass or less, and even more preferably 5% by mass or less. If the content of the extender pigment is greater than the above upper limit, it becomes difficult to improve the light transmittance of the transmissive portion D1. The lower limit of the content of the extender pigment in the semi-light-transmitting layer 3 is not particularly limited as long as the desired light transmittance in the transmissive portion D1 is not impaired, but is, for example, 0.5% by mass or more. The content of the extender pigment is the content when the total material contained in the semi-light-transmitting layer 3 is taken as 100% by mass.

[0065] <Other Details of the Semi-Light-Transmitting Layer> In the semi-light-transmitting layer 3, the total content of the transparent fine particles, color pigment, and extender pigment is preferably 21% by mass or more, more preferably 30% by mass or more, even more preferably 35% by mass or more, particularly preferably 40% by mass or more, and is preferably 80% by mass or less, more preferably 70% by mass or less, even more preferably 65% ​​by mass or less, particularly preferably 60% by mass or less. When the total content of the transparent fine particles, color pigment, and extender pigment is within the above range, the heat resistance and coating hardness of the semi-light-transmitting layer 3 can be further improved. Note that the total content of the transparent fine particles, color pigment, and extender pigment is the content (solids concentration) when the total material contained in the semi-light-transmitting layer 3 is taken as 100% by mass.

[0066] In the light semi-transmitting layer 3, the content ratio of the transparent fine particles to the color pigment (transparent fine particles / color pigment), in mass ratio, is preferably 1.5 or more, more preferably 3 or more, even more preferably 4 or more, and is preferably 750 or less, more preferably 200 or less, even more preferably 50 or less. When the content ratio (transparent fine particles / color pigment) is within the above range, it is possible to further improve the heat resistance and coating hardness of the top plate 1 while maintaining appropriate light transmittance of the transmissive portion D1.

[0067] When the transparent fine particles are barium sulfate, the content ratio of barium sulfate to silicone resin (barium sulfate / silicone resin) in the semi-light-transmitting layer 3 is, in mass ratio, preferably 0.28 or more, more preferably 0.9 or more, even more preferably 1 or more, and preferably 3.75 or less, more preferably 2 or less, even more preferably 1.5 or less. When the content ratio (barium sulfate / silicone resin) is within the above range, the heat resistance and coating hardness of the top plate 1 can be further improved while maintaining an appropriate light transmittance of the transmissive portion D1.

[0068] The semi-light-transmitting layer 3 may contain other components as long as they do not impair the effects of the present invention. Examples of other components include glass. However, it is preferable that the content of other components in the semi-light-transmitting layer 3 is as small as possible.

[0069] The thickness of the semi-light-transmitting layer 3 is preferably 5 μm or more, more preferably 7 μm or more, and preferably 30 μm or less, more preferably 20 μm or less. When the thickness of the semi-light-transmitting layer 3 is equal to or greater than the above-mentioned lower limit, the transparent fine particles, color pigments, and extender pigments in the semi-light-transmitting layer 3 are less likely to protrude from the surface of the semi-light-transmitting layer 3. As a result, when assembling a cookware using the top plate 1 or when using the cookware after assembly, peeling of the semi-light-transmitting layer 3 due to peripheral components or fingers getting caught on the surface can be prevented. Furthermore, when the thickness of the semi-light-transmitting layer 3 is equal to or less than the above-mentioned upper limit, the amount of material used to form the semi-light-transmitting layer 3 can be reduced, thereby reducing the manufacturing cost of the top plate 1. The thickness of the semi-light-transmitting layer 3 can be measured using a scanning electron microscope (SEM).

[0070] (Light-shielding layer) The light-shielding layer 4 is disposed on the rear surface 2b side of the glass substrate 2. The light-shielding layer 4 is in contact with the rear surface 2b of the glass substrate 2. In the present invention, another layer may be disposed between the light-shielding layer 4 and the glass substrate 2.

[0071] The light-shielding layer 4 is a layer for blocking light from the light source 10. The light-shielding layer 4 can also enhance the concealment of the internal structure of the cooking appliance. Furthermore, by appropriately adjusting the color tone of the light-shielding layer 4, the design of the top plate 1 can be improved. The light-shielding layer 4 can have the same structure as a conventionally known light-shielding layer used in top plates.

[0072] The light-shielding layer 4 contains a color pigment. The light-shielding layer 4 may be a layer containing a heat-resistant resin and a color pigment, or a layer containing glass and a color pigment. However, from the viewpoint of improving the continuity between the light-shielding layer 4 and the semi-light-transmitting layer 3 and more reliably suppressing light transmission through the interface between the light-shielding layer 4 and the semi-light-transmitting layer 3, it is preferable that the light-shielding layer 4 does not contain glass but is a layer containing a heat-resistant resin and a color pigment.

[0073] <Coloring Pigment> Examples of the coloring pigment that can be used in the light-shielding layer 4 include the coloring pigments described above in the section on the light-semitransmitting layer 3. The type of coloring pigment can be changed appropriately depending on the desired color tone of the light-shielding layer 4. Only one type of coloring pigment may be used, or two or more types may be used in combination.

[0074] The content of the color pigment in the light-shielding layer 4 is preferably 15% by mass or more, more preferably 20% by mass or more, and preferably 40% by mass or less, more preferably 35% by mass or less. When the content of the color pigment is within the above range, the light-shielding layer 4 can have a further improved light-shielding property, and the ability to conceal the internal structure of the cooking appliance can be further improved. The content of the color pigment is the content when the total material contained in the light-shielding layer 4 is taken as 100% by mass.

[0075] <Heat-Resistant Resin> Examples of heat-resistant resins that can be used in the light-shielding layer 4 include silicone resins and polyimide resins. The heat-resistant resins may be used alone or in combination of two or more.

[0076] The heat-resistant resin is preferably a silicone resin from the viewpoint of further increasing the heat resistance of the light-shielding layer 4. Examples of the silicone resin include the silicone resins described in the section on the semi-light-transmitting layer 3 above.

[0077] The content of the heat-resistant resin in the light-shielding layer 4 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 heat-resistant resin is equal to or greater than the above-mentioned lower limit, the heat resistance, solvent resistance, and impact resistance of the light-shielding layer 4 are further increased, and the continuity between the light-shielding layer 4 and the semi-light-transmitting layer 3 is improved, thereby more reliably suppressing light transmission through the interface between the light-shielding layer 4 and the semi-light-transmitting layer 3. When the content of the heat-resistant resin is equal to or less than the above-mentioned upper limit, the mechanical strength of the light-shielding layer 4 can be further increased. The content of the heat-resistant resin is the content when the entire material contained in the light-shielding layer 4 is taken as 100% by mass.

[0078] <Glass> When the light-shielding layer 4 contains glass, conventionally known glass can be used as the glass. Only one type of glass may be used, or two or more types may be used in combination.

[0079] Examples of glass include borosilicate glass; silicate glass containing at least one of an alkali metal component and an alkaline earth metal component; and phosphate glass containing zinc and aluminum.

[0080] The glass content in the light-shielding layer 4 is preferably 0% by mass or more, more preferably 10% by mass or more, and preferably 55% by mass or less, more preferably 50% by mass or less. When the glass content is equal to or greater than the above-mentioned lower limit, the adhesion between the glass substrate 2 and the light-shielding layer 4 can be further improved. When the glass content is equal to or less than the above-mentioned upper limit, the stress at the interface between the glass substrate 2 and the light-shielding layer 4, which is caused by the difference in thermal expansion coefficient between the glass substrate 2 and the light-shielding layer 4, is reduced, and a decrease in the mechanical strength of the top plate 1 can be further suppressed. The glass content is the content when the entire material contained in the light-shielding layer 4 is taken as 100% by mass.

[0081] <Extender Pigment> The light-shielding layer 4 may contain an extender pigment. The extender pigment is a pigment different from the transparent fine particles, glass, and color pigment. The light-shielding layer 4 may be a layer containing a heat-resistant resin, a color pigment, and an extender pigment, or may be a layer containing glass, a color pigment, and an extender pigment. Only one type of extender pigment may be used, or two or more types may be used in combination.

[0082] Examples of extender pigments that can be used in the light-shielding layer 4 include talc, mica, calcium carbonate, potassium titanate, calcium silicate, and titanium oxide. Use of an extender pigment can further increase the mechanical strength of the top plate 1. These extender pigments may be used alone or in combination.

[0083] The shape of the extender pigment contained in the light-shielding layer 4 is not particularly limited, but for example, scale-like, spherical, needle-like, or irregularly shaped extender pigments can be used.

[0084] The content of the extender pigment in the light-shielding layer 4 is not particularly limited and can be, for example, 10% by mass or more and 50% by mass or less. The content of the extender pigment is the content when the total amount of the materials contained in the light-shielding layer 4 is taken as 100% by mass.

[0085] <Other Details of Light-Shielding Layer> The light-shielding layer 4 may contain other components different from the above-mentioned components, as long as the effects of the present invention are not impaired.

[0086] The thickness of the light-shielding layer 4 is preferably 5 μm or more, more preferably 7 μm or more, and is preferably 40 μm or less, more preferably 20 μm or less. When the thickness of the light-shielding layer 4 is within the above range, the hiding power of the inside of the cooking appliance can be further improved.

[0087] (Other Details of the Top Plate) The light transmittance of the transparent portion D1 in the visible wavelength range at a wavelength of 500 nm is preferably 2% or more, preferably 90% or less, and more preferably 80% or less. When the light transmittance is equal to or greater than the above-mentioned lower limit, the visibility of the information displayed on the transparent portion D1 can be further improved. When the light transmittance is equal to or less than the above-mentioned upper limit, the ability of the transparent portion D1 to conceal the internal structure of the cooking appliance can be further improved.

[0088] The light transmittance of the non-transparent portion D2 in the visible wavelength range at a wavelength of 500 nm is preferably 5% or less, more preferably 1% or less. When the light transmittance of the non-transparent portion D2 is equal to or less than the upper limit, the concealment of the internal structure of the cooking appliance can be further improved.

[0089] In the case of the top plate 1, the top plate 1 was placed on a black board with the back surface 2b facing downward, and the L measured from the cooking surface 2a side in the transmission area D1 was ＊ a ＊ b ＊ L in color system ＊ The value is preferably 38 or less, more preferably 30 or less, and even more preferably 28.5 or less. In this case, the transmissive portion D1 can have a jet-black appearance when the light source 10 is turned off, and therefore the design of the top plate 1 as a whole can be further improved. ＊The lower limit of the value is not particularly limited, but can be set to 25, for example.

[0090] (Manufacturing Method) A manufacturing method of the top plate 1 includes, for example, the steps of preparing a glass substrate 2, applying a semi-light-transmitting layer-forming paste to a portion of the rear surface 2b of the glass substrate 2 where the transmissive portion D1 will be formed, and firing the glass substrate 2 on which the semi-light-transmitting layer-forming paste has been applied. The manufacturing method of the top plate 1 preferably includes the steps of applying a light-shielding layer-forming paste to a portion of the rear surface 2b of the glass substrate 2 where the non-transmissive portion D2 will be formed, and firing the glass substrate 2 on which the light-shielding layer-forming paste has been applied. In this case, for example, first, the portion of the top plate 1 where the transmissive portion D1 will be formed may be masked, the light-shielding layer-forming paste may be applied to the non-transmissive portion D2, and then the semi-light-transmitting layer-forming paste may be applied to the portion of the top plate 1 where the transmissive portion D1 will be formed. However, it is also possible to first mask the portion of the top plate 1 where the non-transparent portion D2 will be formed, apply a paste for forming a semi-transparent layer to the portion where the transparent portion D1 will be formed, and then apply a paste for forming a light-shielding layer to the portion of the top plate 1 where the non-transparent portion D2 will be formed.

[0091] Method for forming semi-light-transmitting layer: The paste for forming the semi-light-transmitting layer is a material for the semi-light-transmitting layer 3, and contains a silicone resin, a color pigment, and transparent fine particles. The paste for forming the semi-light-transmitting layer preferably contains components that volatilize when heated, such as a resin binder and a solvent.

[0092] The solvent is not particularly limited, but for example, an aromatic hydrocarbon can be used. Among them, it is preferable to use xylene as the solvent. In this case, even when transparent fine particles are used, sedimentation and separation of the transparent fine particles can be more reliably suppressed in the process of mixing the components when preparing the paste for forming the light semi-transmitting layer, thereby further improving productivity.

[0093] The semi-light-transmitting layer forming paste is applied to a predetermined region on the rear surface 2b of the glass substrate 2. It is preferable to apply the semi-light-transmitting layer forming paste continuously and uniformly. As a method for applying the semi-light-transmitting layer forming paste, for example, a screen printing method can be used. In this case, masking can be performed by providing a mask on the screen plate to be printed.

[0094] The application speed and viscosity of the paste for forming a semi-light-transmitting layer can be appropriately set depending on the contents of the color pigment and transparent fine particles in the paste for forming a semi-light-transmitting layer.

[0095] The method for manufacturing the top plate 1 may or may not include a step of drying the semi-light-transmitting layer-forming paste. The drying temperature in the step of drying the semi-light-transmitting layer-forming paste can be, for example, 50° C. or higher and 300° C. or lower, and the drying time can be, for example, 1 minute or higher and 100 hours or lower.

[0096] Next, the glass substrate 2 coated with the paste for forming a semi-light-transmitting layer is baked. This allows the semi-light-transmitting layer 3 containing the silicone resin, color pigment, and transparent fine particles to be obtained. The baking temperature can be, for example, 100°C or higher and 700°C or lower. The baking time can be, for example, 1 minute or higher and 100 hours or lower.

[0097] Method for forming light-shielding layer: The light-shielding layer-forming paste is a material for the light-shielding layer 4. The light-shielding layer-forming paste may contain, for example, glass frit and a coloring pigment, or may contain a heat-resistant resin and a coloring pigment. However, from the viewpoint of improving the continuity between the obtained light-shielding layer 4 and the semi-light-transmitting layer 3 and more reliably suppressing light transmission through the interface between the light-shielding layer 4 and the semi-light-transmitting layer 3, it is preferable that the paste contain a heat-resistant resin and a coloring pigment. The light-shielding layer-forming paste preferably contains a component that volatilizes upon heating, such as a solvent. The light-shielding layer-forming paste may also contain an extender pigment.

[0098] The light-shielding layer-forming paste is applied to a predetermined region on the rear surface 2b of the glass substrate 2. It is preferable to apply the light-shielding layer-forming paste continuously and uniformly. As a method for applying the light-shielding layer-forming paste, for example, a screen printing method can be used. In this case, masking can be performed by providing a mask on the screen plate to be printed.

[0099] The application speed and viscosity of the paste for forming a light-shielding layer can be appropriately set depending on the contents of the color pigment and extender pigment in the paste for forming a light-shielding layer.

[0100] The method for manufacturing the top plate 1 preferably includes a step of drying the light-shielding layer-forming paste. The drying temperature in the step of drying the light-shielding layer-forming paste can be, for example, 100° C. or higher and 700° C. or lower, and the drying time can be, for example, 1 minute or higher and 100 hours or lower.

[0101] The method for manufacturing the top plate 1 may include a step of firing the glass substrate 2 on which the light-shielding layer-forming paste has been applied. When the light-shielding layer-forming paste contains glass frit, a color pigment, and an extender pigment, the method for manufacturing the top plate 1 preferably includes a step of firing the glass substrate 2 on which the light-shielding layer-forming paste has been applied. The firing temperature can be, for example, 100°C or higher and 1000°C or lower. The firing time can be, for example, 1 minute or higher and 100 hours or shorter.

[0102] In the method for manufacturing the top plate 1, the light-shielding layer 4 may be formed after the semi-light-transmitting layer 3 is formed, or the light-shielding layer 4 may be formed before the semi-light-transmitting layer 3 is formed. In the method for manufacturing the top plate 1, the light-shielding layer-forming paste may be applied after the semi-light-transmitting layer-forming paste is applied, or the semi-light-transmitting layer-forming paste may be applied after the light-shielding layer-forming paste is applied. The drying of the semi-light-transmitting layer-forming paste and the drying of the light-shielding layer-forming paste may be performed separately or simultaneously. The firing of the glass substrate 2 on which the semi-light-transmitting layer-forming paste is applied and the firing of the glass substrate 2 on which the light-shielding layer-forming paste is applied may be performed separately or simultaneously.

[0103] 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.

[0104] As shown in FIG. 2 , the top plate 21 further includes an inorganic layer 5. The inorganic layer 5 is provided directly on the rear surface 2b of the glass substrate 2. The inorganic layer 5 is provided on both the transmissive portion D1 and the non-transmissive portion D2. In the transmissive portion D1, a semi-transmissive layer 3 is further provided on the inorganic layer 5. Furthermore, in the non-transmissive portion D2, a light-shielding layer 4 is further provided on the inorganic layer 5. In this manner, in the top plate 21, the semi-transmissive layer 3 and the light-shielding layer 4 are provided on the rear surface 2b of the glass substrate 2 via the inorganic layer 5. By providing the semi-transmissive layer 3 and the light-shielding layer 4 on the rear surface 2b of the glass substrate 2 via the inorganic layer 5 as in the top plate 21, the adhesion between the glass substrate 2 and each layer can be further improved. Other points are the same as those in the first embodiment.

[0105] The inorganic layer 5 may be, for example, a layer containing glass and a color pigment, a layer containing glass and an extender pigment, a layer containing glass, a color pigment and an extender pigment, or a layer containing glass, a color pigment, an extender pigment, and transparent microparticles. The glass, color pigment, extender pigment, and transparent microparticles described above in the sections on the light-semitransmitting layer 3 and the light-blocking layer 4 can be used as the glass, color pigment, extender pigment, and transparent microparticles. The inorganic layer 5 is preferably a layer with high light transmittance. Therefore, the content of the color pigment in the inorganic layer 5 is, for example, 1% by mass or more and 10% by mass or less. The content of the extender pigment in the inorganic layer 5 is, for example, 20% by mass or more and 40% by mass or less. The content of the transparent microparticles in the inorganic layer 5 is, for example, 20% by mass or more and 40% by mass or less. The contents of the color pigment, extender pigment, and transparent microparticles are calculated based on the total mass of the materials contained in the inorganic layer 5 taken as 100% by mass. A heat-resistant resin may be used instead of the glass in the inorganic layer 5. That is, a heat-resistant resin layer may be provided in place of the inorganic layer 5. As the heat-resistant resin, the heat-resistant resins described in the above section regarding the light-shielding layer 4 can be used.

[0106] In the top plate 21, the semi-light-transmitting layer 3 (resin layer) also contains a silicone resin, a color pigment, and transparent microparticles. Therefore, even if the content of transparent microparticles is increased in order to improve the heat resistance and coating hardness of the semi-light-transmitting layer 3, the light transmittance of the semi-light-transmitting layer 3 is unlikely to decrease. Furthermore, by adjusting the content of the color pigment and transparent microparticles while increasing the content of transparent microparticles in the semi-light-transmitting layer 3, it is possible to easily adjust the light transmittance of the semi-light-transmitting layer 3 to an appropriate level. Therefore, the top plate 21 including such a semi-light-transmitting layer 3 can obtain excellent heat resistance and coating hardness while maintaining an appropriate light transmittance in the transmissive portion D1, and can provide a top plate suitable for the intended use.

[0107] The present invention will be described in more detail below with reference to examples. However, the following examples are merely illustrative and are not intended to limit the scope of the present invention.

[0108] The following glass substrates were prepared:

[0109] Transparent crystallized glass plate (Nippon Electric Glass Co., Ltd. "N-0", average linear thermal expansion coefficient at 30°C to 750°C: 0.5 × 10 －７ / ℃, thickness: 4mm)

[0110] The following materials for the semi-light-transmitting layer were prepared. The average particle sizes of the color pigment, transparent fine particles, and extender pigment are median sizes derived from volume distributions measured by laser diffraction scattering, and were measured using a laser diffraction particle size distribution analyzer (Microtrac-Bell, model number "Microtrac MT30002"). The weight-average molecular weight (Mw) of the silicone resin was measured using gel permeation chromatography (GPC, Tosoh, model number "HLC-8420GPC").

[0111] Silicone resin component: Methylphenyl silicone resin (weight average molecular weight (Mw): 7000) Multifunctional silicone oligomer (weight average molecular weight (Mw): 700)

[0112] Color pigment: Black pigment (average particle size: 0.1 μm)

[0113] Transparent fine particles: Barium sulfate A (average particle size: 0.01 μm) Barium sulfate B (average particle size: 0.3 μm)

[0114] Extender pigment: Talc (average particle size: 5 μm)

[0115] Solvent: Xylene

[0116] (Example 1) Preparation of paste for forming semi-light-transmitting layer: A silicone resin component, a color pigment, and transparent fine particles were mixed with a solvent in a solid mass ratio (silicone resin component:color pigment:transparent fine particles) of 45:0.3:54.7 to prepare a paste for forming a semi-light-transmitting layer.

[0117] Preparation of a top plate for a cooking appliance: A paste for forming a semi-light-transmitting layer was screen-printed onto the rear surface of a glass substrate to a thickness of 10 μm. The resulting substrate was then baked at 300° C. for 30 minutes to form a semi-light-transmitting layer, yielding a top plate. Tables 1 and 2 show the contents of each component in the semi-light-transmitting layer.

[0118] (Examples 2 to 10 and Comparative Examples 1 to 3) Top plates were obtained in the same manner as in Example 1, except that the content and type of each component in the paste for forming a semi-light-transmitting layer were changed as shown in Tables 1 and 2 below.

[0119] [Evaluation] (1) Light Transmittance The light transmittance of the obtained top plate at a wavelength of 500 nm was measured using a spectrophotometer (manufactured by JASCO Corporation, product number "V-770") from the cooking surface side of the glass substrate of the top plate.

[0120] (2) Appearance of the top plate (L ＊ The obtained top plate was placed on a black board with the back surface (semi-light-transmitting layer side) facing downward, and ＊ a ＊ b ＊ L in color system ＊ The value was measured. ＊ a ＊ b ＊ L in color system ＊The values ​​were evaluated from the cooking surface side (the side opposite to the semi-transparent layer) using a color difference meter (manufactured by Konica Minolta, product number "CM-600D").

[0121] (3) Coating Hardness The pencil hardness of the obtained top plate was evaluated from the light semi-transmitting layer side in accordance with JIS K 5600-5-4.

[0122] (4) Heat Resistance The obtained top plate was placed in an oven and heated for 100 hours at 350° C. Then, the top plate was removed from the oven, and the state of the removed top plate was visually observed.

[0123] <Evaluation criteria> ○...No change ×...Defects such as cracks, breaks, and peeling

[0124] The details and results are shown in Tables 1 and 2 below.

[0125]

[0126]

[0127] As is clear from Tables 1 and 2, the top plates of Examples 1 to 10, in which the semi-light-transmitting layer contained a silicone resin, a color pigment, and transparent fine particles, were confirmed to have excellent heat resistance and coating hardness while maintaining appropriate light transmittance in the transmissive portion that transmits light from the light source. On the other hand, the top plates of Comparative Examples 1 and 2, in which the semi-light-transmitting layer did not contain transparent fine particles, did not have sufficient heat resistance. Furthermore, Comparative Example 3, which contained a white extender pigment, had excellent heat resistance and coating hardness, but low light transmittance.

[0128] DESCRIPTION OF SYMBOLS 1, 21... Cooking appliance top plate 2... Glass substrate 2a... Cooking surface 2b... Back surface 3... Light semi-transmitting layer 4... Light blocking layer 5... Inorganic layer 10... Light source D1... Transmitting portion D2... Non-transmitting portion

Claims

1. A top plate for a cooking appliance having a transmissive portion that transmits light from a light source, comprising: a glass substrate having a cooking surface on which a cooking utensil is placed and a back surface opposite the cooking surface; and a semi-light-transmitting layer disposed on the back surface of the glass substrate, wherein the semi-light-transmitting layer is provided on the transmissive portion, and the semi-light-transmitting layer contains silicone resin, color pigment, and transparent fine particles.

2. The top plate for a cooker according to claim 1, wherein the transparent fine particles have an average particle size of 0.1 μm or less.

3. The top plate for a cooker according to claim 2, wherein the transparent fine particles include barium sulfate.

4. A top plate for a cooker as described in claim 3, wherein the content of said barium sulfate is 43 mass % or more and 60 mass % or less in 100 mass % of said semi-light-transmitting layer.

5. A top plate for a cooker according to claim 3 or 4, wherein the content ratio of the barium sulfate to the silicone resin (barium sulfate / silicone resin) is 0.9 or more and 2 or less in mass ratio.

6. A top plate for a cooking appliance according to any one of claims 1 to 4, further comprising a light-shielding layer having a non-transparent portion that blocks light from a light source, the light-shielding layer being disposed on the back surface side of the glass substrate and positioned so as to overlap the non-transparent portion in a plan view.

7. Place the cooker top plate on a black board so that the back side is the lower surface, and measure the L from the cooking surface side in the transmission area. ＊ a ＊ b ＊ L in color system ＊ The top plate for a cooker according to any one of claims 1 to 4, wherein the value is 30 or less.

8. A method for manufacturing a top plate for a cooking appliance having a translucent portion that transmits light from a light source, comprising the steps of: preparing a glass substrate having a cooking surface on which a cooking utensil is placed and a back surface opposite the cooking surface; applying a paste for forming a semi-light-transmitting layer to a portion of the back surface of the glass substrate where the translucent portion will be formed; and firing the glass substrate with the paste for forming the semi-light-transmitting layer applied, wherein the paste for forming the semi-light-transmitting layer contains a silicone resin, a color pigment, and transparent fine particles.

9. The method for manufacturing a cookware top plate according to claim 8, wherein the transparent fine particles include barium sulfate.

Images