阅读说明：本技术 烹调器用顶板及其制造方法 (Top plate for cooking utensil and its manufacturing method ) 是由 横山尚平 小西弘孙 土谷武史 于 2018-09-27 设计创作，主要内容包括：本发明提供一种金属感优异、能够提高外观设计性,并且含有金属色泽颜料的层的剥离和裂纹的发生少的烹调器用顶板。其特征在于,包括：玻璃基板2,其具有载置烹调器具的烹调面2b和与该烹调面2b为相反侧的背面2a；金属色泽层3,其设置于玻璃基板2的背面2a上,含有第一金属色泽颜料；第一耐热树脂层4,其设置于金属色泽层3上,含有第二金属色泽颜料；和第二耐热树脂层5,其设置于第一耐热树脂层4上,含有无机颜料。(The invention provides a top plate for a cooking device, which has excellent metal feeling, can improve appearance design and has less peeling of a layer containing a metal color pigment and less generation of cracks. It is characterized by comprising: a glass substrate 2 having a cooking surface 2b on which a cooking device is placed and a back surface 2a opposite to the cooking surface 2 b; a metallic luster layer 3 that is provided on the back surface 2a of the glass substrate 2 and contains a first metallic luster pigment; a first heat-resistant resin layer 4 provided on the metallic luster layer 3 and containing a second metallic luster pigment; and a second heat-resistant resin layer 5 provided on the first heat-resistant resin layer 4 and containing an inorganic pigment.)

1. A top plate for a cooking appliance, comprising:

a glass substrate having a cooking surface on which a cooking device is placed and a back surface opposite to the cooking surface;

a metallic luster layer disposed on the back surface of the glass substrate, the metallic luster layer containing a first metallic luster pigment;

a first heat-resistant resin layer which is provided on the metallic luster layer and contains a second metallic luster pigment; and

and a second heat-resistant resin layer which is provided on the first heat-resistant resin layer and contains an inorganic pigment.

2. The top plate for a cooking appliance according to claim 1, wherein:

the second metallic color pigment comprises a metallic color pigment in common with the first metallic color pigment.

3. The top plate for a cooking appliance according to claim 1 or 2, wherein:

the first heat-resistant resin layer contains 40 to 95 mass% of a first heat-resistant resin and 5 to 60 mass% of the second metallic luster pigment.

4. The top plate for a cooking device according to any one of claims 1 to 3, wherein:

the metal color layer contains, by mass%, 40% to 60% of glass cullet and 40% to 60% of the first metal color pigment.

5. The top plate for a cooking device according to any one of claims 1 to 4, wherein:

the content of the second metallic luster pigment per unit volume contained in the first heat-resistant resin layer is less than the content of the first metallic luster pigment per unit volume contained in the metallic luster layer.

6. The top plate for a cooking device according to any one of claims 1 to 5, wherein:

the thickness of the first heat-resistant resin layer is 1-30 μm,

the thickness of the metal luster layer is 1-20 μm.

7. A method for manufacturing a top plate for a cooking device, the method being used for manufacturing the top plate for a cooking device described in any one of 1 to 6, the method comprising:

applying a paste for forming a metal color layer containing the first metal color pigment to the back surface of the glass substrate and firing the paste to form the metal color layer on the back surface of the glass substrate;

applying a first heat-resistant resin layer-forming paste containing the second metallic luster pigment and a second heat-resistant resin layer-forming paste containing the inorganic pigment in this order on the metallic luster layer; and

and a step of firing the first heat-resistant resin layer forming paste and the second heat-resistant resin layer forming paste at the same time or one at a time.

Technical Field

The present invention relates to a top plate for a cooking device and a method for manufacturing the top plate for a cooking device.

Background

As a top plate used for cooking devices such as an electromagnetic cooker, a radiant heating cooker, and a gas cooker, a glass substrate having heat resistance, which is made of crystallized glass, borosilicate glass, or the like having a low thermal expansion coefficient, is used. When a transparent glass substrate is used as the glass substrate, a light-shielding layer or a metallic luster layer is generally formed on the back surface located inside the cooker in order to cover the structure inside the cooker and improve the design.

Patent document 1 below discloses a glass top plate disposed above a heating cooker. In the glass top plate of patent document 1, a bead tone layer is provided on a back surface of the glass ceramic substrate opposite to the cooking surface. In addition, a protective layer is provided on the pearlescent flake layer. The protective layer has a light-shielding portion formed of a heat-resistant resin and an inorganic pigment.

Disclosure of Invention

Technical problem to be solved by the invention

However, when a heat-resistant resin layer is provided on the layer containing the metallic luster pigment on the back surface of the top plate for a cooking device, a sufficient metallic feeling cannot be obtained, and the design may be impaired. On the other hand, in the case where the heat-resistant resin layer is not provided, when a heating device or the like comes into contact with the top plate for a cooking utensil, the layer containing the metallic luster pigment may be peeled off, or the layer containing the metallic luster pigment may be cracked.

The purpose of the present invention is to provide a top plate for a cooking device that has excellent metallic appearance, can improve design properties, and has little delamination of a layer containing a metallic luster pigment and little occurrence of cracks, and a method for manufacturing the top plate for a cooking device.

Technical solution for solving technical problem

The top plate for a cooking device according to the present invention is characterized by comprising: a glass substrate having a cooking surface on which a cooking device is placed and a back surface opposite to the cooking surface; a metal luster layer provided on the back surface of the glass substrate and containing a first metal luster pigment; a first heat-resistant resin layer which is provided on the metallic luster layer and contains a second metallic luster pigment; and a second heat-resistant resin layer which is provided on the first heat-resistant resin layer and contains an inorganic pigment.

In the present invention, it is preferable that the second metallic luster pigment contains a metallic luster pigment common to the first metallic luster pigment.

In the present invention, it is preferable that the first heat-resistant resin layer contains 40 to 95% by mass of the first heat-resistant resin and 5 to 60% by mass of the second metallic luster pigment.

In the present invention, it is preferable that the metal color layer contains 40% to 60% by mass of crushed glass and 40% to 60% by mass of the first metal color pigment.

In the present invention, it is preferable that the content of the second metallic luster pigment per unit volume contained in the first heat-resistant resin layer is less than the content of the first metallic luster pigment per unit volume contained in the metallic luster layer.

In the present invention, it is preferable that the first heat-resistant resin layer has a thickness of 1 to 30 μm and the metallic luster layer has a thickness of 1 to 20 μm.

The method for manufacturing a top plate for a cooking device according to the present invention is a method for manufacturing a top plate for a cooking device configured according to the present invention, the method including: applying a paste for forming a metal color layer containing the first metal color pigment to the back surface of the glass substrate and firing the paste to form the metal color layer on the back surface of the glass substrate; applying a first heat-resistant resin layer forming paste containing the second metallic color pigment and a second heat-resistant resin layer forming paste containing the inorganic pigment to the metallic color layer in this order; and a step of firing the first heat-resistant resin layer forming paste and the second heat-resistant resin layer forming paste simultaneously or one by one.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, a top plate for a cooking device and a method for manufacturing the top plate for a cooking device can be provided, which have excellent metallic feeling, can improve design properties, and can reduce the occurrence of peeling and cracking of a layer containing a metallic luster pigment.

Drawings

Fig. 1 is a schematic front cross-sectional view illustrating a top plate for a cooking device according to an embodiment of the present invention.

Detailed Description

Hereinafter, preferred embodiments will be described. However, the following embodiments are merely examples, and the present invention is not limited to the following embodiments. In the drawings, components having substantially the same function may be referred to by the same reference numerals.

[ Top plate for cooking apparatus ]

Fig. 1 is a schematic front cross-sectional view illustrating a top plate for a cooking device according to an embodiment of the present invention. As shown in fig. 1, a top plate for cooking 1 (hereinafter, "top plate for cooking 1" is abbreviated as "top plate 1") includes a glass substrate 2. The glass substrate 2 has a cooking surface 2b as one main surface and a back surface 2a as the other main surface. The cooking surface 2b is a surface on which a cooking utensil such as a pan or a pan can be placed. The back surface 2a is a surface facing the heating device on the inner side of the cooker. The cooking surface 2b and the back surface 2a are in a front-back relationship with each other.

The glass substrate 2 has a metal-colored layer 3 on the back surface 2a thereof. The metallic luster layer 3 is a porous film comprising crushed glass and a first metallic luster pigment. Of course, the metallic luster layer 3 may be a dense film having substantially no voids, and is not particularly limited as long as it contains the first metallic luster pigment.

The first heat-resistant resin layer 4 is provided on the metallic luster layer 3 (on the side opposite to the side in contact with the glass substrate 2). The first heat-resistant resin layer 4 contains a first heat-resistant resin and a second metallic color pigment. In the present embodiment, the first heat-resistant resin is colorless and transparent. In the present specification, the term "colorless and transparent" means that the transmittance of light in the visible wavelength region having a wavelength of 450 to 700nm is 70% or more.

The second heat-resistant resin layer 5 is provided on the first heat-resistant resin layer 4 (on the side opposite to the side in contact with the metallic luster layer 3). The second heat-resistant resin layer 5 contains a second heat-resistant resin and an inorganic pigment. The inorganic pigment is a different pigment than the first metallic color pigment and the second metallic color pigment. In the present embodiment, the inorganic pigment is a coloring inorganic pigment.

The main feature of the present embodiment is that the first heat-resistant resin layer 4 is provided between the metallic luster layer 3 and the second heat-resistant resin layer 5. Since the first heat-resistant resin layer 4 is provided between the metallic luster layer 3 and the second heat-resistant resin layer 5, the top sheet 1 has an excellent metallic feeling, and the design can be improved. The reason for this will be described below.

As described above, the metallic luster layer 3 is a porous film containing glass cullet and a first metallic luster pigment. Therefore, when the second heat-resistant resin layer 5 containing another inorganic pigment such as a coloring inorganic pigment as an inorganic pigment is directly formed on the metallic luster layer 3, the other inorganic pigment enters the metallic luster layer 3, and the metallic feeling is impaired.

In contrast, in the case where the first heat-resistant resin layer 4 containing the second metallic luster pigment is provided between the metallic luster layer 3 and the second heat-resistant resin layer 5 as in the present embodiment, the presence of the first heat-resistant resin layer 4 makes it difficult for other inorganic pigments contained in the second heat-resistant resin layer 5 to enter the metallic luster layer 3. Further, the first heat-resistant resin layer 4 is directly formed on the metallic luster layer 3. Therefore, even if the second metallic luster pigment contained in the first heat-resistant resin layer 4 enters the porous metallic luster layer 3, the metallic feeling is hardly impaired because the pigment is a metallic luster pigment. This provides the top plate 1 with excellent metallic appearance, and improves the design.

Further, since the first heat-resistant resin layer 4 and the second heat-resistant resin layer 5 are provided in the top sheet 1, even if a heating device or the like comes into contact with the top sheet 1, these resin layers absorb impact, and it is possible to suppress peeling of the metal-colored layer 3 or generation of cracks in the metal-colored layer 3.

The following describes the details of the layers constituting the top plate 1.

(glass substrate)

The glass substrate 2 transmits at least a part of light having a wavelength of 450 to 700 nm. The glass substrate 2 may be colored and transparent, and is preferably colorless and transparent from the viewpoint of further improving the aesthetic appearance of the top sheet 1.

The top plate 1 is repeatedly heated and cooled, and therefore, the glass substrate 2 preferably has high heat resistance and a low coefficient of thermal expansion, and specifically, the softening temperature of the glass substrate 2 is preferably 700 ℃ or more, more preferably 750 ℃ or more, and further, the average linear thermal expansion coefficient of the glass substrate 2 in the range of 30 ℃ to 750 ℃ is preferably-10 × 10^－7/℃～+60×10^－7In the range of-10 × 10/deg.C, more preferably-10 ×^－7/℃～+50×10^－7Within the range of/DEG C, still more preferably-10 × 10^－7/℃～+40×10^－7In the range/° c. Therefore, the glass substrate 2 is preferably made of glass having a high glass transition temperature and a low expansion, or crystallized glass having a low expansion. Specific examples of the low-expansion crystallized glass include "N-0" manufactured by Nippon Denko K.K. As the glass substrate 2, borosilicate glass or the like can be used.

(Metal color layer)

The metallic luster layer 3 comprises crushed glass and a first metallic luster pigment.

As the crushed glass, for example, B can be used₂O₃－SiO₂Glass powder and ZnO-B₂O₃Glass powder, SiO₂－Al₂O₃Glass powder, etc.

The content (ratio) of the crushed glass particles in the metallic luster layer 3 is preferably 40% to 60% by mass, and more preferably 45% to 55% by mass. When the content of the crushed glass particles is within the above range, the adhesion between the glass substrate 2 and the metal luster layer 3 can be further improved. The content of the crushed glass is the content when the entire material contained in the metal luster layer 3 is 100 mass%.

In addition, as the first metallic color pigment, for example, a pigment in which the surface of an inorganic pigment is coated with a metal oxide can be used.

As the inorganic pigment contained in the first metallic color pigment, kaolin, talc, sericite, pyroelectric ferrite, mica, alumina, silica, or the like can be used. Among them, a pearlescent pigment obtained by using a flake obtained by pulverizing natural mica as a base material and coating the surface thereof with a metal oxide is preferably used. Further, an effect pigment obtained by using an artificially produced flake such as an alumina flake, a silica flake, or a flake glass as a base material and coating the surface thereof with a metal oxide can also be used. Examples of the metal oxide used for the pearlescent pigment or the effect pigment include titanium oxide, tin oxide, zirconium oxide, iron oxide, and the like. In addition, these first metallic color pigments may be used alone or in combination of two or more.

The content (ratio) of the first metallic luster pigment in the metallic luster layer 3 is preferably 40% by mass or more and 60% by mass or less, and more preferably 45% by mass or more and 55% by mass or less. When the content of the first metallic luster pigment is within the above range, the metallic feeling of the metallic luster layer 3 can be further improved. The content of the first metallic luster pigment is the content when the entire material contained in the metallic luster layer 3 is 100 mass%.

The thickness of the metal luster layer 3 is not particularly limited. The thickness of the metal luster layer 3 can be appropriately set, for example, in accordance with the light transmittance, mechanical strength, thermal expansion coefficient, or the like of the metal luster layer 3. Among them, the metal color layer 3 generally has a different thermal expansion coefficient from the glass substrate 2. Therefore, the metal color layer 3 may be damaged due to repeated heating and cooling.

From the viewpoint of further suppressing the damage, the thickness of the metal luster layer 3 is preferably small. The thickness of the metallic luster layer 3 is preferably 1 μm or more and 20 μm or less, and more preferably 3 μm or more and 15 μm or less.

(first Heat-resistant resin layer)

The first heat-resistant resin layer 4 contains a first heat-resistant resin and a second metallic color pigment.

The first heat-resistant resin is preferably colorless and transparent. In this case, the metallic feeling of the top plate 1 can be further improved. Of course, the first heat-resistant resin may be colored as long as the metallic feeling of the top panel 1 is not impaired.

The first heat-resistant resin preferably has high heat resistance. As such a first heat-resistant resin, for example, a silicone resin, a polyimide resin, or the like can be used. Among these, a silicone resin in which a functional group directly bonded to a silicon atom is at least one of a methyl group and a phenyl group is preferable. In this case, the heat resistance of the top plate 1 can be further improved. The first heat-resistant resin may be used alone or in combination of two or more.

The content (ratio) of the first heat-resistant resin in the first heat-resistant resin layer 4 is preferably 40% or more and 95% or less, and more preferably 60% or more and 90% or less, in terms of mass%. When the content of the first heat-resistant resin is within the above range, the heat resistance of the top sheet 1 can be further improved. The content of the first heat-resistant resin is a content when the entire material contained in the first heat-resistant resin layer 4 is 100 mass%.

As the second metallic luster pigment, the pearlescent pigment, the effect pigment, and the like described in the column of the first metallic luster pigment can be used. The second metallic luster pigment may be used alone or in combination of two or more kinds of the above pearlescent pigment and effect pigment.

In addition, the second metallic luster pigment may be a different metallic luster pigment than the first metallic luster pigment, but is preferably the same metallic luster pigment as the first metallic luster pigment. When the second metallic luster pigment is the same metallic luster pigment as the first metallic luster pigment, the metallic feel of the top panel 1 can be further improved.

In addition, in the case where a plurality of first metallic luster pigments are contained in the metallic luster layer 3, it is preferable that the first heat-resistant resin layer 4 contains the same second metallic luster pigment as at least 1 of the plurality of first metallic luster pigments, and it is more preferable that the first heat-resistant resin layer 4 contains the same second metallic luster pigment as all of the plurality of first metallic luster pigments. In this case as well, the metallic feeling of the top plate 1 can be further improved.

The content (ratio) of the second metallic luster pigment in the first heat-resistant resin layer 4 is preferably 5% by mass or more and 60% by mass or less, and more preferably 10% by mass or more and 40% by mass or less. When the content of the second metallic color pigment is within the above range, the metallic feeling of the top sheet 1 can be further improved. In addition, even when the top plate 1 is repeatedly heated and cooled, peeling due to cracks caused by expansion and contraction can be further suppressed. The content of the second metallic luster pigment is the content when the entire material contained in the first heat-resistant resin layer 4 is 100 mass%.

The content of the second metallic luster pigment per unit volume contained in the first heat-resistant resin layer 4 is preferably less than the content of the first metallic luster pigment per unit volume contained in the metallic luster layer 3. In this case, the first heat-resistant resin layer 4 easily penetrates into the metallic luster layer 3, and the second heat-resistant resin layer 5 hardly penetrates into the first heat-resistant resin layer 4.

The thickness of the first heat-resistant resin layer 4 is not particularly limited. The thickness of the first heat-resistant resin layer 4 may be appropriately set according to the light transmittance of the first heat-resistant resin layer 4 and the like. The thickness of the first heat-resistant resin layer 4 may be, for example, about 1 μm to 30 μm.

(second Heat-resistant resin layer)

The second heat-resistant resin layer 5 contains a second heat-resistant resin and an inorganic pigment.

As the second heat-resistant resin, for example, the silicone resin, polyimide resin, or the like described in the section of the first heat-resistant resin can be used. The second heat-resistant resin may be used alone or in combination of two or more.

The second heat-resistant resin may be a different resin from the first heat-resistant resin, and is preferably the same resin as the first heat-resistant resin. When the second heat-resistant resin is the same resin as the first heat-resistant resin, the adhesion between the first heat-resistant resin layer 4 and the second heat-resistant resin layer 5 can be further improved.

The content (ratio) of the second heat-resistant resin in the second heat-resistant resin layer 5 is preferably 40% or more and 70% or less, and more preferably 50% or more and 60% or less, in terms of mass%. When the content of the second heat-resistant resin is within the above range, the heat resistance of the top sheet 1 can be further improved. The content of the second heat-resistant resin is a content when the entire material contained in the second heat-resistant resin layer 5 is 100 mass%.

The inorganic pigment contained in the second heat-resistant resin layer 5 is preferably a colored pigment powder. The coloring pigment is a colored inorganic substance. When the coloring pigment powder is used as the inorganic pigment, the second heat-resistant resin layer 5 can be colored, and therefore the structure inside the cooker can be more reliably covered.

Examples of the coloring pigment powder include TiO₂Powder, ZrO₂Powder or ZrSiO₄White pigment powder such as powder, blue inorganic pigment powder containing Co, green inorganic pigment powder containing Co, yellow inorganic pigment powder of Ti-Sb-Cr system or Ti-Ni system, red inorganic pigment powder of Co-Si system, brown inorganic pigment powder containing Fe, black inorganic pigment powder containing Cu, etc.

Specific examples of the Co-containing blue inorganic pigment powder include Co-Al based or Co-Al-Ti based inorganic pigment powders. Specific examples of the Co-Al-based inorganic pigment powder include CoAl₂O₄Powders, and the like. Specific examples of the Co-Al-Ti-based inorganic pigment powder include CoAl₂O₄－TiO₂－Li₂O powder, and the like.

Specific examples of the Co-containing green inorganic pigment powder include Co-Al-Cr-based or Co-Ni-Ti-Zn-based inorganic pigment powders. AsSpecific examples of the Co-Al-Cr-based inorganic pigment powder include Co (Al, Cr)₂O₄Powders, and the like. Specific examples of the Co-Ni-Ti-Zn-based inorganic pigment powder include (Co, Ni, Zn)₂TiO₄Powders, and the like.

Specific examples of the Fe-containing brown inorganic pigment-based powder include Fe — Zn inorganic pigment powders. Specific examples of the Fe-Zn-based inorganic pigment powder include (Zn, Fe) Fe₂O₄Powders, and the like.

Specific examples of the Cu-containing black inorganic pigment powder include Cu-Cr-based inorganic pigment powder and Cu-Fe-based inorganic pigment powder. Specific examples of the Cu-Cr-based inorganic pigment powder include Cu (Cr, Mn)₂O₄Powder, Cu-Cr-Mn powder, etc. Specific examples of the Cu-Fe-based inorganic pigment powder include Cu-Fe-Mn powder and the like.

The content of the inorganic pigment in the second heat-resistant resin layer 5 is preferably 30% by mass or more and 60% by mass or less, and more preferably 40% by mass or more and 50% by mass or less. When the content of the inorganic pigment is within the above range, the structure inside the cooker can be more effectively hidden. The content of the inorganic pigment is a content when the entire material contained in the second heat-resistant resin layer 5 is 100 mass%.

The thickness of the second heat-resistant resin layer 5 is not particularly limited. The thickness of the second heat-resistant resin layer 5 may be appropriately set according to the light transmittance of the second heat-resistant resin layer 5 and the like. The thickness of the second heat-resistant resin layer 5 may be, for example, about 1 μm to 30 μm.

(other embodiments)

In the above embodiment, the case where the metallic luster layer 3, the first heat-resistant resin layer 4, and the second heat-resistant resin layer 5 are formed on the entire back surface 2a of the glass substrate 2 has been described. However, the present invention is not limited to this configuration. The metallic luster layer 3, the first heat-resistant resin layer 4, and the second heat-resistant resin layer 5 may be formed on a part of the back surface 2a of the glass substrate 2, for example. For example, in the case where the cooker is an electromagnetic heating cooker, the first and second heat-resistant resin layers 4 and 5 may be provided only at the electromagnetic heating portion of the top panel 1.

In the above embodiment, an example in which no film is formed on the cooking surface 2b of the glass substrate 2 is described. However, the present invention is not limited to this configuration. For example, a decorative film may be formed on the cooking surface 2b as necessary to improve design and display heater positions.

A film may be further formed on the back surface 2a side of the glass substrate 2. For example, a decorative coating may be formed between the glass substrate 2 and the metal luster layer 3 in order to improve design and display heater positions. Further, a protective layer or the like of the second heat-resistant resin layer 5 may be formed on the second heat-resistant resin layer 5, or an adhesive layer or the like may be formed between the respective layers.

(method of manufacturing Top plate for cooking utensil)

The top plate 1 can be manufactured by the following manufacturing method, for example.

First, the metal luster layer 3 is formed on the back surface 2a of the glass substrate 2. Specifically, first, a solvent is added to a mixed powder of the ground glass particles and the first metallic luster pigment powder to form a paste. The obtained paste for forming a metallic color layer is applied to the back surface 2a of the glass substrate 2 by screen printing or the like, and dried. Next, the dried paste is fired, whereby the metallic luster layer 3 can be formed. The firing temperature and the firing time may be appropriately set according to the composition of the glass cullet or the like to be used. The firing temperature may be, for example, about 700 to 900 ℃. The firing time may be, for example, about 10 minutes to 1 hour.

Next, the first heat-resistant resin layer 4 is formed on the metallic luster layer 3. Specifically, first, the first heat-resistant resin and the second metallic luster pigment powder are mixed, and a solvent is added to form a paste. The obtained first heat-resistant resin layer-forming paste is applied onto the metallic luster layer 3 by screen printing or the like, and dried. Next, the dried paste is fired, whereby the first heat-resistant resin layer 4 can be formed. The firing temperature and the firing time may be appropriately set according to the composition of the resin or the like used. The firing temperature may be, for example, about 250 to 500 ℃. The firing time may be, for example, about 10 minutes to 1 hour.

Next, the second heat-resistant resin layer 5 is formed on the first heat-resistant resin layer 4. Specifically, first, the second heat-resistant resin and the inorganic pigment powder are mixed, and a solvent is added to form a paste. The obtained second heat-resistant resin layer forming paste is applied onto the first heat-resistant resin layer 4 by screen printing or the like, and dried. Next, the dried paste is fired, whereby the second heat-resistant resin layer 5 can be formed. The firing temperature and the firing time may be appropriately set according to the composition of the resin or the like used. The firing temperature may be, for example, about 250 to 500 ℃. The firing time may be, for example, about 10 minutes to 1 hour.

However, the first heat-resistant resin layer forming paste and the second heat-resistant resin layer forming paste may be fired simultaneously.

The present invention will be described in more detail below with reference to examples. However, the following examples are only illustrative. The present invention is not limited in any way by the following examples.

(example 1)

First, a paste was prepared by mixing 50 mass% of crushed glass with 20 mass% of a metal pigment a, 25 mass% of a metal pigment B, and 5 mass% of a metal pigment C as a first metal color pigment, and adding 200 mass% of an organic solvent. As the crushed glass, use is made of B₂O₃－SiO₂Glass powder (trade name "NPF" manufactured by Nippon electric glass Co., Ltd.). As the metal pigment A, a pigment (silver type, average particle diameter: 10 μm to 60 μm) obtained by coating the surface of mica with titanium oxide was used. As the metal pigment B, a pigment (white, average particle) obtained by coating the surface of mica with titanium oxide and tin oxide was usedDiameter: 5-25 μm). As the metallic pigment C, a pigment (a pink pigment having an average particle diameter of 5 to 50 μm) obtained by coating the surface of silica (silica flakes) with iron oxide is used.

Next, the resulting paste was screen-printed (screen mesh; #180M) to a thickness of 20 μ M on a transparent crystallized glass plate (trade name "N-0" manufactured by Nippon electric glass Co., Ltd., average linear thermal expansion coefficient at 30 ℃ to 750 ℃ C.: 0.5X 10-7/. degree. C.) as a whole. Then, the substrate was dried at 100 ℃ for 5 minutes and then fired at 800 ℃ for 60 minutes, thereby forming a metallic luster layer.

Next, 39 mass% of a transparent silicone resin, 9 mass% of metal pigment a, 9 mass% of metal pigment B, and 4 mass% of metal pigment C were mixed, and 39 mass% of an organic solvent was added to prepare a paste. Among them, the same metal pigment A, B, C and organic solvent as used in the metal color layer were used. In addition, a resin containing both methyl groups and phenyl groups is used as the silicone resin.

Next, the paste was screen-printed (screen mesh; #180M) to a thickness of 10 μ M on the entire metallic luster layer thus produced. Then, the sheet was dried at 70 ℃ for 5 minutes and fired at 300 ℃ for 60 minutes, thereby forming a first heat-resistant resin layer.

Next, 34 mass% of a silicone resin, 2 mass% of a Cu-Cr-Mn based black inorganic pigment (coloring inorganic pigment), and 27 mass% of TiO were mixed₂The powders were mixed, and 37 mass% of an organic solvent was added to prepare a paste. Wherein the silicone resin is the same resin as the first heat-resistant resin layer.

Then, the paste was screen-printed (screen mesh; #180M) to a thickness of 10 μ M over the entire first heat-resistant resin layer prepared above. Then, the sheet was dried at 70 ℃ for 5 minutes and fired at 300 ℃ for 60 minutes, thereby forming a second heat-resistant resin layer, and a top sheet was obtained.

(examples 2 to 4)

A top plate was obtained in the same manner as in example 1, except that the first metallic color pigment was changed to the kind and the blending amount shown in table 1 below when the metallic luster layer was formed, and the silicone resin and the second metallic color pigment were changed to the kind and the blending amount shown in table 2 below when the first heat-resistant resin layer was formed. The amount in table 2 is shown as a solid content. As the metallic pigment D, a pigment (orange type, average particle diameter: 5 to 35 μm) obtained by coating the surface of mica with iron oxide or titanium oxide is used.

Comparative example 1

A top plate was produced in the same manner as in example 1, except that the first heat-resistant resin layer was not provided and the second heat-resistant resin layer was directly formed on the metallic luster layer.

(evaluation)

The metallic feeling of the top plates obtained in examples 1 to 4 and comparative example 1 when viewed from the cooking surface side was judged visually according to the following judgment criteria. The results are shown in Table 2.

[ judgment standards ]

Good metallic feeling of O …

The metallic feeling of Δ … was slightly excellent

Metal deficiency of x …

A tape pull test was performed as an evaluation method of film peeling of the top sheet obtained in examples 1 to 4 and comparative example 1. Specifically, a transparent tape (cellophane tape) was pressed with a finger against the printed portion of each top plate, and then the tape was peeled off, and the portion peeled off with the tape and portions other than the portion were visually observed. "o" indicates that the peeled portion is not different from the other portions. On the other hand, a case where the difference is generated is represented as "x".

[ Table 1]

[ Table 2]

As is clear from table 2, the top sheets of examples 1 to 4 provided with the first heat-resistant resin layer are excellent in metallic feeling and less in the occurrence of peeling and cracking of the layer containing the metallic luster pigment, as compared with the top sheet of comparative example 1 not provided with the first heat-resistant resin layer.

Description of the symbols

1 … top plate for cooking utensil;

2 … glass substrate;

2a … back;

2b … cooking surface;

3 … a metallic luster layer;

4 … a first heat resistant resin layer;

5 … second heat resistant resin layer.