Enameled ware capable of being placed in microwave oven and preparation method thereof

Abstract

The invention belongs to the technical field of enamel materials, and particularly discloses an enamel ware capable of being placed in a microwave oven, which comprises a metal matrix, and a first enamel layer, a second enamel layer and a third enamel layer which are sequentially coated on the surface of the metal matrix; the first porcelain glaze layer is prepared from the following raw materials in percentage by mass: 1 to 5 percent of titanium dioxide, 40 to 55 percent of silicon dioxide, 2 to 5 percent of zirconium dioxide, 30 to 40 percent of diboron trioxide, 3 to 5 percent of aluminum oxide, 2 to 3 percent of cobalt oxide and 2 to 3 percent of nickel protoxide; the second ceramic glaze layer is prepared from the following raw materials: 1 to 5 percent of titanium dioxide, 48 to 50 percent of silicon dioxide, 3 to 5 percent of zirconium dioxide, 35 to 40 percent of diboron trioxide and 4 to 5 percent of aluminum oxide; and the second ceramic glaze layer is prepared from the following raw materials: 1-5% of titanium dioxide, 48-50% of silicon dioxide, 3-5% of zirconium dioxide, 35-40% of diboron trioxide and 4-5% of aluminum oxide, so that the protection on the metal matrix is enhanced, the metal matrix is prevented from generating electric sparks, the reflection of microwaves is weakened, the microwave oven is not damaged, and the purpose of using the ceramic glaze in the microwave oven is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of enamel materials, in particular to an enamel ware that can be placed in a microwave oven and a preparation method thereof. Background Art

[0002] Enamel is an inorganic glass glaze applied to a metal surface. Applying enamel to a metal surface prevents rust, protects the metal from oxidation when heated, and resists corrosion from various liquids. Enamel products are safe, non-toxic, and easy to clean, making them widely used in daily eating and drinking utensils and washing utensils.

[0003] Ovens and microwave ovens are the most commonly used baking appliances by daily consumers, so the quality of their baking performance will directly affect consumers' cooking experience. However, enamelware cannot be heated in a microwave oven. The reason is that when enamelware is heated in a microwave oven, the metal base will generate electric sparks and reflect microwaves, which will damage the components inside the microwave oven and prevent the food from being cooked thoroughly. At the same time, enamel materials are also more susceptible to temperature changes, especially in a localized heating environment such as a microwave oven. This may cause the enamel layer to crack or partially fall off, and the exposed metal parts will cause the above-mentioned problems, which can easily damage the microwave oven or cause danger. Summary of the Invention

[0004] In order to overcome the defects of the prior art, the present invention provides an enamel ware that can be placed in a microwave oven and a preparation method thereof, which solves the problem in the prior art that when the enamel ware is placed in a microwave oven for heating, the metal substrate generates electric sparks and reflects microwaves, which may damage the components inside the microwave oven.

[0005] The technical solution adopted by the present invention to solve its technical problem is: The first embodiment of the present invention provides an enamel ware that can be placed in a microwave oven, comprising a metal substrate and a first enamel layer, a second enamel layer and a third enamel layer sequentially coated and fired on the surface of the metal substrate; By mass percentage, The raw materials of the first glaze layer contain: titanium dioxide 1-5%, silicon dioxide 40-55%, zirconium dioxide 2-5%, boron trioxide 30-40%, aluminum trioxide 3-5%, cobalt oxide 2-3%, nickelous oxide 2-3%; The raw materials of the second glaze layer contain: titanium dioxide 1-5%, silicon dioxide 48-50%, zirconium dioxide 3-5%, boron trioxide 35-40%, aluminum oxide 4-5%; The raw materials of the second glaze layer include: titanium dioxide 1-5%, silicon dioxide 48-50%, zirconium dioxide 3-5%, boron trioxide 35-40%, and aluminum oxide 4-5%.

[0006] The idea of ​​solving the problem in this solution is that the silicon dioxide and zirconium dioxide in the porcelain glaze layer of this solution serve as absorbing materials, which can absorb part of the microwaves in the microwave oven. Moreover, by sequentially coating the surface of the metal substrate with the first porcelain glaze layer, the second porcelain glaze layer and the third porcelain glaze layer, the first porcelain glaze layer, the second porcelain glaze layer and the third porcelain glaze layer all contain silicon dioxide and zirconium dioxide. Compared with a single-layer porcelain glaze layer, the three-layer porcelain glaze layer can better absorb microwaves, thereby strengthening the protection of the metal substrate, avoiding electric sparks on the metal substrate and weakening microwave reflection, so as not to damage the microwave oven and achieving the purpose of being able to be used in a microwave oven.

[0007] As a further solution, the carbon content of the metal matrix is ​​0.01-0.1% by mass.

[0008] Specifically, the carbon content of the metal matrix is ​​relatively low, between 0.01-0.1%, and the metal matrix is ​​preferably an iron plate, that is, the metal matrix is ​​a low-carbon iron plate, so that the enameled ware can effectively reduce the generation of related gases in the metal matrix during the sintering process, and the porcelain glaze is better combined with the metal matrix, so that the porcelain glaze layer has better adhesion, and the glaze of the porcelain glaze layer is firmly attached to the surface of the metal matrix and is not easy to peel off, which greatly reduces the quality problems of "porcelain explosion" and "scale explosion".

[0009] A second embodiment of the present invention provides a method for preparing a microwave-safe enamel ware, the method being used to produce the aforementioned microwave-safe enamel ware, the method comprising the following steps: S1. Raw materials containing titanium dioxide, silicon dioxide, zirconium dioxide, boron trioxide, aluminum trioxide, cobalt oxide, and nickelous oxide are charged into a ball mill according to a proportion, and water is added thereto for grinding and mixing to obtain glaze slip A. Raw materials containing titanium dioxide, silicon dioxide, zirconium dioxide, boron trioxide, and aluminum trioxide are charged into a ball mill, and water is added thereto for grinding and mixing to obtain glaze slip B. S2: Immerse the metal substrate in glaze slurry A for the first glazing. After soaking, remove the metal substrate and shake the slurry evenly on the surface of the metal substrate. Then, dry it at 100-200°C for 10-30 minutes, then fire it at 820-850°C for 3-5 minutes. After firing, let it cool at room temperature to form the first glaze layer, thus obtaining semi-finished product A. S3, immerse semi-finished product A in glaze slurry B for a second glazing. After immersion, take out the semi-finished product A and shake the slurry evenly. Then, dry it at 100-200℃ for 10-30 minutes, then fire it at 810-830℃ for 3-5 minutes. After firing, let it cool at room temperature to form a second glaze layer, thus obtaining semi-finished product B. S4, immersing the semi-finished product B in the glaze slurry B for the third glazing, taking it out after immersion and shaking the slurry on the surface of the semi-finished product B evenly, then drying it at 100-200°C for 10-30 minutes, and then firing it at 800-820°C for 3-5 minutes. After firing, it is placed at room temperature to cool to form a third glaze layer, thereby obtaining the enameled vessel.

[0010] Specifically, in the preparation method of enamelware, high-temperature firing above 800°C has the following advantages compared to low-temperature firing: ① Improve the glaze layer's resistance to cold and heat shocks to avoid cracks in the glaze layer caused by sudden temperature changes; at the same time, improve the glaze layer's high-temperature resistance, so that the glaze layer of enamelware can better maintain structural stability and surface color in high-temperature cooking environments, avoiding structural damage or color changes.

[0011] ② Improve the chemical corrosion resistance of the porcelain glaze layer to avoid long-term contact of the porcelain glaze layer with certain acidic or alkaline substances, which may cause the porcelain glaze layer to fall off, be damaged or discolored.

[0012] ③ Improve the bonding strength between the porcelain glaze and the metal substrate, making the bonding tighter, thereby improving the adhesion of the porcelain glaze layer and avoiding the problem of porcelain glaze layer breaking or falling off due to collision or friction.

[0013] At the same time, glazing and firing are carried out three times to form the first glaze layer, the second glaze layer and the third glaze layer. Compared with a single-layer glaze layer, the three-layer glaze layer can better absorb microwaves, thereby enhancing the protection of the metal substrate.

[0014] As a further solution, in step S1, after the glaze slurry A is ground and mixed, the weight of the residue after screening through a 200-mesh sieve is 2-6 g, and the specific gravity of the slurry is controlled at 1.65-1.75.

[0015] As a further solution, in step S1, after the glaze slurry B is ground and mixed, the weight of the residue after screening through a 200-mesh sieve is 2-4 g, and the specific gravity of the slurry is controlled at 1.55-1.65.

[0016] The beneficial effects of the present invention are: 1. The silica and zirconium dioxide in the porcelain glaze layer of this scheme serve as absorbing materials to absorb microwaves in microwave ovens. By sequentially coating the surface of the metal substrate with the first, second and third porcelain glaze layers, the first, second and third porcelain glaze layers all contain silica and zirconium dioxide. Compared with a single-layer porcelain glaze layer, the three-layer porcelain glaze layer can better absorb microwaves, thereby strengthening the protection of the metal substrate, preventing the metal substrate from generating electric sparks and weakening microwave reflection, thereby not damaging the microwave oven and achieving the purpose of being able to be used in a microwave oven.

[0017] 2. The metal matrix is ​​a low-carbon iron plate, which can effectively reduce the generation of related gases in the metal matrix during the sintering process of the enameled ware. The porcelain glaze is better combined with the metal matrix, so that the porcelain glaze layer has better adhesion. The glaze of the porcelain glaze layer is firmly attached to the surface of the metal matrix and is not easy to peel off, which greatly reduces the quality problems of "porcelain explosion" and "scale explosion".

[0018] 3. In the preparation method of enamelware, high-temperature firing above 800℃ has the following advantages compared with low-temperature firing: ① Improve the glaze layer's resistance to cold and heat shocks to avoid cracks in the glaze layer caused by sudden temperature changes; at the same time, improve the glaze layer's high-temperature resistance, so that the glaze layer of enamelware can better maintain structural stability and surface color in high-temperature cooking environments, avoiding structural damage or color changes.

[0019] ② Improve the chemical corrosion resistance of the porcelain glaze layer to avoid long-term contact of the porcelain glaze layer with certain acidic or alkaline substances, which may cause the porcelain glaze layer to fall off, be damaged or discolored.

[0020] ③ Improve the bonding strength between the porcelain glaze and the metal substrate, making the bonding tighter, thereby improving the adhesion of the porcelain glaze layer and avoiding the problem of porcelain glaze layer breaking or falling off due to collision or friction. DETAILED DESCRIPTION

[0021] The following is a further description of specific embodiments of the present invention. It should be noted that the description of these embodiments is intended to facilitate understanding of the present invention and does not constitute a limitation of the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

[0022] It should be noted that in the following embodiments, the carbon content of the metal substrate is 0.01-0.1%, preferably 0.06%, and is a low-carbon iron plate. Enamelware has an open structure, and microwaves in a microwave oven can heat the food in the vessel through the opening.

[0023] Example 1 An enamel ware that can be placed in a microwave oven comprises a metal base and a first enamel layer, a second enamel layer and a third enamel layer sequentially coated and fired on the surface of the metal base; By mass percentage, The raw materials of the first glaze layer include: titanium dioxide 3%, silicon dioxide 50%, zirconium dioxide 3%, boron trioxide 35%, aluminum trioxide 4%, cobalt oxide 2%, nickelous oxide 3%; The raw materials of the second glaze layer contain: titanium dioxide 1%, silicon dioxide 50%, zirconium dioxide 5%, boron trioxide 40%, aluminum oxide 4%; The raw materials of the second glaze layer include: titanium dioxide 1%, silicon dioxide 50%, zirconium dioxide 5%, boron trioxide 40%, and aluminum oxide 4%.

[0024] A method for preparing enamelware that can be placed in a microwave oven comprises the following steps: S1. Raw materials containing titanium dioxide, silicon dioxide, zirconium dioxide, boron trioxide, aluminum trioxide, cobalt oxide, and nickelous oxide are mixed according to the mixing ratio. Water is added and the mixture is ground and mixed. The weight of the residue after screening through a 200-mesh sieve is controlled to be between 2-6 g, and the specific gravity of the slurry is controlled to be between 1.65-1.75, thereby obtaining glaze slip A. Raw materials containing titanium dioxide, silicon dioxide, zirconium dioxide, boron trioxide, and aluminum trioxide are mixed in a ball mill. Water is added and the mixture is ground and mixed. The weight of the residue after screening through a 200-mesh sieve is controlled to be between 2-4 g, and the specific gravity of the slurry is controlled to be between 1.55-1.65, thereby obtaining glaze slip B. S2: Immerse the metal substrate in glaze slurry A for the first glazing. After immersion, remove the metal substrate and shake the slurry evenly on the surface of the metal substrate. Then, dry it at 150°C for 20 minutes, then fire it at 850°C for 4 minutes. After firing, let it cool at room temperature to form the first glaze layer, obtaining semi-finished product A. S3, immerse semi-finished product A in glaze slurry B for a second glazing. After immersion, take out the semi-finished product A and shake the slurry evenly. Then, dry it at 150°C for 20 minutes, then fire it at 830°C for 4 minutes. After firing, let it cool at room temperature to form a second glaze layer, thus obtaining semi-finished product B. S4, immersing the semi-finished product B in the glaze slurry B for the third glazing, taking it out after immersion and shaking the slurry on the surface of the semi-finished product B evenly, then drying it at 150°C for 20 minutes, and then firing it at 820°C for 4 minutes. After firing, it is placed at room temperature to cool to form a third porcelain glaze layer, thereby obtaining the enameled vessel.

[0025] Example 2 An enamel ware that can be placed in a microwave oven comprises a metal base and a first enamel layer, a second enamel layer and a third enamel layer sequentially coated and fired on the surface of the metal base; By mass percentage, The raw materials of the first glaze layer contain: titanium dioxide 1%, silicon dioxide 55%, zirconium dioxide 2%, boron trioxide 34%, aluminum trioxide 3%, cobalt oxide 3%, nickelous oxide 2%; The raw materials of the second glaze layer include: titanium dioxide 5%, silicon dioxide 50%, zirconium dioxide 5%, boron trioxide 35%, aluminum oxide 5%; The raw materials of the second glaze layer include: 5% titanium dioxide, 50% silicon dioxide, 5% zirconium dioxide, 35% boron trioxide, and 5% aluminum oxide.

[0026] A method for preparing enamelware that can be placed in a microwave oven comprises the following steps: S1. Raw materials containing titanium dioxide, silicon dioxide, zirconium dioxide, boron trioxide, aluminum trioxide, cobalt oxide, and nickelous oxide are mixed according to the mixing ratio. Water is added and the mixture is ground and mixed. The weight of the residue after screening through a 200-mesh sieve is controlled to be between 2-6 g, and the specific gravity of the slurry is controlled to be between 1.65-1.75, thereby obtaining glaze slip A. Raw materials containing titanium dioxide, silicon dioxide, zirconium dioxide, boron trioxide, and aluminum trioxide are mixed in a ball mill. Water is added and the mixture is ground and mixed. The weight of the residue after screening through a 200-mesh sieve is controlled to be between 2-4 g, and the specific gravity of the slurry is controlled to be between 1.55-1.65, thereby obtaining glaze slip B. S2: Immerse the metal substrate in glaze slurry A for the first glazing. After soaking, remove the metal substrate and shake the slurry evenly on the surface of the metal substrate. Then, dry it at 150°C for 20 minutes, then fire it at 830°C for 4 minutes. After firing, let it cool at room temperature to form the first glaze layer, thus obtaining semi-finished product A. S3, immersing semi-finished product A in glaze slurry B for a second glazing. After immersion, the semi-finished product A is taken out and the slurry on the surface of the semi-finished product A is shaken evenly. The semi-finished product A is then dried at 150°C for 20 minutes and fired at 820°C for 4 minutes. After firing, the semi-finished product is allowed to cool at room temperature to form a second glaze layer, thereby obtaining semi-finished product B. S4, immersing the semi-finished product B in the glaze slurry B for the third glazing, taking it out after immersion and shaking the slurry on the surface of the semi-finished product B evenly, then drying it at 150°C for 20 minutes, and then firing it at 810°C for 4 minutes. After firing, it is placed at room temperature to cool to form a third glaze layer, thereby obtaining the enameled vessel.

[0027] Example 3 An enamel ware that can be placed in a microwave oven comprises a metal base and a first enamel layer, a second enamel layer and a third enamel layer sequentially coated and fired on the surface of the metal base; By mass percentage, The raw materials of the first glaze layer include: titanium dioxide 5%, silicon dioxide 40%, zirconium dioxide 5%, boron trioxide 40%, aluminum trioxide 5%, cobalt oxide 3%, nickelous oxide 2%; The raw materials of the second glaze layer include: titanium dioxide 3%, dioxide 50%, dioxide 3%, boron trioxide 40%, aluminum trioxide 4%; The raw materials of the second glaze layer include: 3% titanium dioxide, 50% silicon dioxide, 3% zirconium dioxide, 40% boron trioxide, and 4% aluminum oxide.

[0028] A method for preparing enamelware that can be placed in a microwave oven comprises the following steps: S1. Raw materials containing titanium dioxide, silicon dioxide, zirconium dioxide, boron trioxide, aluminum trioxide, cobalt oxide, and nickelous oxide are mixed according to the mixing ratio. Water is added and the mixture is ground and mixed. The weight of the residue after screening through a 200-mesh sieve is controlled to be between 2-6 g, and the specific gravity of the slurry is controlled to be between 1.65-1.75, thereby obtaining glaze slip A. Raw materials containing titanium dioxide, silicon dioxide, zirconium dioxide, boron trioxide, and aluminum trioxide are mixed in a ball mill. Water is added and the mixture is ground and mixed. The weight of the residue after screening through a 200-mesh sieve is controlled to be between 2-4 g, and the specific gravity of the slurry is controlled to be between 1.55-1.65, thereby obtaining glaze slip B. S2: Immerse the metal substrate in glaze slurry A for the first glazing. After immersion, remove the metal substrate and shake the slurry evenly on the surface of the metal substrate. Then, dry it at 150°C for 20 minutes, then fire it at 850°C for 4 minutes. After firing, let it cool at room temperature to form the first glaze layer, obtaining semi-finished product A. S3, immerse semi-finished product A in glaze slurry B for a second glazing. After immersion, take out the semi-finished product A and shake the slurry evenly. Then, dry it at 150°C for 20 minutes, then fire it at 830°C for 4 minutes. After firing, let it cool at room temperature to form a second glaze layer, thus obtaining semi-finished product B. S4, immersing the semi-finished product B in the glaze slurry B for the third glazing, taking it out after immersion and shaking the slurry on the surface of the semi-finished product B evenly, then drying it at 150°C for 20 minutes, and then firing it at 810°C for 4 minutes. After firing, it is placed at room temperature to cool to form a third glaze layer, thereby obtaining the enameled vessel.

[0029] Example 4 An enamel ware that can be placed in a microwave oven comprises a metal base and a first enamel layer, a second enamel layer and a third enamel layer sequentially coated and fired on the surface of the metal base; By mass percentage, The raw materials of the first glaze layer include: titanium dioxide 5%, silicon dioxide 50%, zirconium dioxide 5%, boron trioxide 30%, aluminum trioxide 5%, cobalt oxide 3%, nickelous oxide 2%; The raw materials of the second glaze layer contain: titanium dioxide 1%, dioxide 50%, zirconium dioxide 5%, boron trioxide 39%, aluminum oxide 5%; The raw materials of the second glaze layer include: titanium dioxide 1%, silicon dioxide 50%, zirconium dioxide 5%, boron trioxide 39%, and aluminum oxide 5%.

[0030] A method for preparing enamelware that can be placed in a microwave oven comprises the following steps: S1. Raw materials containing titanium dioxide, silicon dioxide, zirconium dioxide, boron trioxide, aluminum trioxide, cobalt oxide, and nickelous oxide are mixed according to the mixing ratio. Water is added and the mixture is ground and mixed. The weight of the residue after screening through a 200-mesh sieve is controlled to be between 2-6 g, and the specific gravity of the slurry is controlled to be between 1.65-1.75, thereby obtaining glaze slip A. Raw materials containing titanium dioxide, silicon dioxide, zirconium dioxide, boron trioxide, and aluminum trioxide are mixed in a ball mill. Water is added and the mixture is ground and mixed. The weight of the residue after screening through a 200-mesh sieve is controlled to be between 2-4 g, and the specific gravity of the slurry is controlled to be between 1.55-1.65, thereby obtaining glaze slip B. S2: Immerse the metal substrate in glaze slurry A for the first glazing. After soaking, remove the metal substrate and shake the slurry evenly on the surface of the metal substrate. Then, dry it at 150°C for 20 minutes, then fire it at 820°C for 4 minutes. After firing, let it cool at room temperature to form the first glaze layer, obtaining semi-finished product A. S3, immerse semi-finished product A in glaze slurry B for a second glazing. After immersion, take out the semi-finished product A and shake the slurry evenly. Then, dry it at 150°C for 20 minutes, then fire it at 810°C for 4 minutes. After firing, let it cool at room temperature to form a second glaze layer, thus obtaining semi-finished product B. S4, immersing the semi-finished product B in the glaze slurry B for the third glazing, taking it out after immersion and shaking the slurry on the surface of the semi-finished product B evenly, then drying it at 150°C for 20 minutes, and then firing it at 800°C for 4 minutes. After firing, it is placed at room temperature to cool to form a third glaze layer, thereby obtaining the enameled vessel.

[0031] Example 5 An enamel ware that can be placed in a microwave oven comprises a metal base and a first enamel layer, a second enamel layer and a third enamel layer sequentially coated and fired on the surface of the metal base; By mass percentage, The raw materials of the first glaze layer contain: titanium dioxide 1%, silicon dioxide 53%, zirconium dioxide 2%, boron trioxide 35%, aluminum trioxide 5%, cobalt oxide 2%, nickelous oxide 2%; The raw materials of the second glaze layer contain: titanium dioxide 2%, silicon dioxide 48%, zirconium dioxide 5%, boron trioxide 40%, aluminum oxide 5%; The raw materials of the second glaze layer include: 2% titanium dioxide, 48% silicon dioxide, 5% zirconium dioxide, 40% boron trioxide, and 5% aluminum oxide.

[0032] A method for preparing enamelware that can be placed in a microwave oven comprises the following steps: S1. Raw materials containing titanium dioxide, silicon dioxide, zirconium dioxide, boron trioxide, aluminum trioxide, cobalt oxide, and nickelous oxide are mixed according to the mixing ratio. Water is added and the mixture is ground and mixed. The weight of the residue after screening through a 200-mesh sieve is controlled to be between 2-6 g, and the specific gravity of the slurry is controlled to be between 1.65-1.75, thereby obtaining glaze slip A. Raw materials containing titanium dioxide, silicon dioxide, zirconium dioxide, boron trioxide, and aluminum trioxide are mixed and the mixture is ground and mixed. The weight of the residue after screening through a 200-mesh sieve is controlled to be between 2-4 g, and the specific gravity of the slurry is controlled to be between 1.55-1.65, thereby obtaining glaze slip B. S2: Immerse the metal substrate in glaze slurry A for the first glazing. After soaking, remove the metal substrate and shake the slurry evenly on the surface of the metal substrate. Then, dry it at 150°C for 20 minutes, then fire it at 820°C for 4 minutes. After firing, let it cool at room temperature to form the first glaze layer, obtaining semi-finished product A. S3, immerse semi-finished product A in glaze slurry B for a second glazing. After immersion, take out the semi-finished product A and shake the slurry evenly. Then, dry it at 150°C for 20 minutes, then fire it at 810°C for 4 minutes. After firing, let it cool at room temperature to form a second glaze layer, thus obtaining semi-finished product B. S4, immersing the semi-finished product B in the glaze slurry B for the third glazing, taking it out after immersion and shaking the slurry on the surface of the semi-finished product B evenly, then drying it at 150°C for 20 minutes, and then firing it at 800°C for 4 minutes. After firing, it is placed at room temperature to cool to form a third glaze layer, thereby obtaining the enameled vessel.

[0033] Comparative Example 1 (the difference from Example 1 is that in the preparation method of enamelware, steps S2, S3, and S4 are fired at a low temperature, and the rest remain the same) An enamel ware that can be placed in a microwave oven comprises a metal base and a first enamel layer, a second enamel layer and a third enamel layer sequentially coated and fired on the surface of the metal base; By mass percentage, The raw materials of the first glaze layer include: titanium dioxide 3%, silicon dioxide 50%, zirconium dioxide 3%, boron trioxide 35%, aluminum trioxide 4%, cobalt oxide 2%, nickelous oxide 3%; The raw materials of the second glaze layer contain: titanium dioxide 1%, silicon dioxide 50%, zirconium dioxide 5%, boron trioxide 40%, aluminum oxide 4%; The raw materials of the second glaze layer include: titanium dioxide 1%, silicon dioxide 50%, zirconium dioxide 5%, boron trioxide 40%, and aluminum oxide 4%.

[0034] A method for preparing enamelware that can be placed in a microwave oven comprises the following steps: S1. Raw materials containing titanium dioxide, silicon dioxide, zirconium dioxide, boron trioxide, aluminum trioxide, cobalt oxide, and nickelous oxide are mixed according to the mixing ratio. Water is added and the mixture is ground and mixed. The weight of the residue after screening through a 200-mesh sieve is controlled to be between 2-6 g, and the specific gravity of the slurry is controlled to be between 1.65-1.75, thereby obtaining glaze slip A. Raw materials containing titanium dioxide, silicon dioxide, zirconium dioxide, boron trioxide, and aluminum trioxide are mixed in a ball mill. Water is added and the mixture is ground and mixed. The weight of the residue after screening through a 200-mesh sieve is controlled to be between 2-4 g, and the specific gravity of the slurry is controlled to be between 1.55-1.65, thereby obtaining glaze slip B. S2: Immerse the metal substrate in glaze slurry A for the first glazing. After immersion, remove the metal substrate and shake the slurry evenly on the surface of the metal substrate. Then, dry it at 150°C for 20 minutes, then fire it at 610°C for 4 minutes. After firing, let it cool at room temperature to form the first glaze layer, thus obtaining semi-finished product A. S3, immerse semi-finished product A in glaze slurry B for a second glazing. After immersion, take out the semi-finished product A and shake the slurry evenly. Then, dry it at 150°C for 20 minutes, then fire it at 610°C for 4 minutes. After firing, let it cool at room temperature to form a second glaze layer, thus obtaining semi-finished product B. S4, immersing the semi-finished product B in the glaze slurry B for the third glazing, taking it out after immersion and shaking the slurry on the surface of the semi-finished product B evenly, then drying it at 150°C for 20 minutes, and then firing it at 600°C for 4 minutes. After firing, it is placed at room temperature to cool to form a third glaze layer, thereby obtaining the enameled vessel.

[0035] Comparative Example 2 (the difference from Example 1 is that the carbon content of the metal matrix is ​​1.5%, and the rest remain the same) Comparative Example 3 (the difference from Example 1 is that only one glaze layer is coated on the surface of the metal substrate, and the other parts remain the same) An enamel ware that can be placed in a microwave oven comprises a metal base and a enamel layer coated and fired on the surface of the metal base; Calculated by mass percentage, the raw materials of the glaze layer contain: 3% titanium dioxide, 50% silicon dioxide, 3% zirconium dioxide, 35% boron trioxide, 4% aluminum trioxide, 2% cobalt oxide, and 3% nickelous oxide.

[0036] A method for preparing enamelware that can be placed in a microwave oven comprises the following steps: S1. Raw materials containing titanium dioxide, silicon dioxide, zirconium dioxide, boron trioxide, aluminum trioxide, cobalt oxide, and nickelous oxide are loaded into a ball mill according to a specific ratio, and water is added for grinding and mixing. The remaining weight after screening through a 200-mesh sieve is controlled to be between 2-6 g, and the specific gravity of the slurry is controlled to be between 1.65-1.75, thereby obtaining a glaze slurry. S2, immerse the metal substrate in the glaze slurry for glazing, take it out after immersion and shake the slurry on the surface of the metal substrate evenly, then dry it at 150℃ for 20 minutes, and then fire it at 850℃ for 4 minutes. After firing, let it cool at room temperature to form a porcelain glaze layer to obtain an enamel vessel.

[0037] Performance Testing 1) Feasibility test of enamelware in microwave oven.

[0038] Purpose of the test: To check whether enamelware can be heated in a microwave oven and whether it will damage the microwave oven.

[0039] Testing equipment: microwave oven, temperature gun.

[0040] Test steps: ① Fill the lunch box with 1 / 3 of room temperature water; ② Place the lunch box in the microwave and close the microwave door; ③ Start the microwave (set to high heat / 10 minutes); ④ Take out the lunch box after microwaving and check whether the enamelware is heated.

[0041] Quality assessment: Enamelware was heated, and the microwave oven did not exhibit any abnormalities during the test.

[0042] The enamelware obtained in Examples 1-5 and Comparative Example 3 was subjected to this test, and the results are shown in Table 1 below: Table 1: The above tests demonstrate that the enameled vessels of the present invention can be used in microwave ovens without damaging them. Because the microwave-absorbing material in the glaze layer generates heat after absorbing microwaves, the surface temperatures of the enameled vessels in Comparative Example 3 were all lower than those in Examples 1-5, indicating that the glaze layers of Examples 1-5 absorb microwaves significantly better than those in Comparative Example 3. Compared to a single-layer glaze layer, a triple-layer glaze layer absorbs microwaves better, thereby enhancing protection for the metal substrate, preventing sparks and reducing microwave reflection.

[0043] 2) Enamel layer adhesion test.

[0044] Test purpose: To ensure the performance of the product.

[0045] Test equipment: Impact test stand (impact rod weight 2kg, impact height 750mm, test rod 15mm).

[0046] Test steps: ① Before testing, check whether there is any porcelain cracking and whether the surface layer thickness is uniform; ② Place the sample under the test rod of the impact tester (the test rod needs to be pressed on the sample plane); ③ Then use a 2kg impact rod to freely fall from a height of 750mm to impact the test rod, causing deformation at the impact point of the sample; ④ Repeat steps ② and ③, and impact 3 random locations on the plane.

[0047] Quality assessment: Observe the degree of damage to the porcelain glaze layer and compare it with the specified requirements.

[0048] Note: The glaze adhesion ratio is the ratio of the area of ​​the glaze remaining on the impact deformation site to the area of ​​the impact deformation site.

[0049] ①Poor adhesion: No glaze adheres to the metal substrate at the impact deformation site after impact, and the edges of the impact deformation site fall off in flakes after impact.

[0050] ② Adhesion failure: After impact, less than 24% of the glaze at the impact deformation site is attached to the metal substrate, but there is no flaking at the edge of the impact deformation site and the glaze is attached; ③ Qualified adhesion: After impact, 25%-49% of the glaze at the impact deformation site is attached to the metal substrate, and the glaze is distributed in a ring shape (no flakes can fall off); ④Good (Grade A): After impact, the glaze at the impact deformation site is distributed in a ring shape (no flakes can fall off), and 50%-74% of the glaze is adhered; ⑤ Excellent adhesion (AA grade): After impact, more than 75% of the glaze at the impact deformation site adheres to the metal substrate and there is no porcelain chipping or falling off.

[0051] The enamelware obtained in Example 1 and Comparative Examples 1-2 were subjected to this test, and the test results are shown in Table 2 below: Table 2: The above tests demonstrate that the glaze layer of the enameled ware of the present invention exhibits excellent adhesion. The glaze adhesion ratio of Example 1 is significantly higher than that of Comparative Example 1, indicating that high-temperature firing above 800°C, compared to low-temperature firing, can enhance the bonding between the glaze and the metal substrate, resulting in a tighter bond and thus improving the adhesion of the glaze layer.

[0052] At the same time, the glaze adhesion ratio of Example 1 is significantly higher than that of Comparative Example 2, indicating that the low carbon content of the metal substrate can effectively reduce the generation of related gases during the sintering process of the enamelware, and the porcelain glaze is better combined with the metal substrate, thereby making the porcelain glaze layer have better adhesion.

[0053] 3) Acid resistance test of porcelain glaze layer.

[0054] Test purpose: To ensure the performance of the product.

[0055] Testing equipment: citric acid, qualitative filter paper, measuring cylinder, measuring cup, stirring rod, cotton cloth, electronic scale.

[0056] Test steps: ① Before testing, wipe off any dirt or impurities on the surface of the product; ② Use an electronic scale and a measuring cup to weigh 5 grams of citric acid, and then use a measuring cylinder to measure out 50 milliliters of water; ③ Slowly pour 50 milliliters of water into the 5 grams of citric acid, and use a stirring rod to mix the citric acid particles and water evenly; ④ Then use the prepared qualitative filter paper to hold it in the citric acid and dip it immediately. Take it out and stick it on the clean surface of enamel for 15 minutes; ⑤ After 15 minutes, tear off the qualitative filter paper, wipe the citric acid on the surface of the enamel with a clean cotton cloth, and observe whether the surface of the test sample has changed color.

[0057] Quality assessment: Hold the qualitative filter paper with your hand and dip it into 10% citric acid. Take it out immediately and stick it on a clean enamel surface. Wait for 15 minutes, then tear off the test paper and wipe off the citric acid. If there is no color change, it is qualified.

[0058] The enamelware obtained in Example 1 and Comparative Example 1 was subjected to this test, and the test results are shown in Table 3 below: Table 3: The above tests show that the enamel layer of the enamelware of the present invention is acid-resistant. The enamel layer of Example 1 does not change color, while the enamel layer of Comparative Example 1 changes color, indicating that high-temperature firing above 800°C can improve the chemical corrosion resistance of the enamel layer compared to low-temperature firing.

[0059] 4) Test of the glaze layer’s resistance to hot and cold temperature differences.

[0060] Test purpose: To ensure the performance of the product.

[0061] Test equipment: constant temperature box.

[0062] Test steps: 1) Before testing, check whether the product has cracks, cracks or surface discoloration; 2) Heat the thermostat to 220±5℃, then put the randomly sampled enamel into the thermostat for 20 minutes; 3) After 20 minutes, take it out and put it into 20±5℃ water to observe whether the product has cracks or discoloration; 4) After wiping off the water of the enamel that has been tested and heated to 220±5℃ and passed, adjust the thermostat to 240±5℃ and then put it into the oven for 20 minutes; 5) After 20 minutes, take it out and put it into 20±5℃ water to observe whether the product has cracks or discoloration; 6) After wiping off the water of the enamel that has been tested and heated to 240±5℃ and passed, adjust the thermostat to 260 ±5℃, then put it in the oven for 20 minutes; 7) After 20 minutes, take it out and put it in water at 20±5℃ to observe whether the product has any cracking or discoloration; 8) After wiping off the water on the enamel that has been tested and heated to 260±5℃ and passed, adjust the thermostat to 280±5℃ and heat it, then put it in the oven for 20 minutes; 9) After 20 minutes, take it out and put it in water at 20±5℃ to observe whether the product has any cracking or discoloration; 10) After wiping off the water on the enamel that has been tested and heated to 280±5℃ and passed, adjust the thermostat to 300±5℃ and heat it, then put it in the oven for 20 minutes; 11) After 20 minutes, take it out and put it in water at 20±5℃ to observe whether the product has any cracking or discoloration.

[0063] Quality Assessment: Randomly sampled enamels are placed in a thermostat at 220±5℃, then kept at this temperature for 20 minutes. After that, take them out and place them in cold water at 20±5℃ to observe if there is any cracking or discoloration on the surface. Products that pass the test of 220±5℃, take them out and place them in cold water at 20±5℃ to observe if there is any cracking or discoloration on the surface are qualified.

[0064] The enamelware obtained in Example 1 and Comparative Example 1 was subjected to this test, and the test results are shown in Table 4 below: Table 4: The above tests show that the porcelain glaze layer of the enamelware of the present invention has a high resistance to cold and heat shocks, indicating that high-temperature firing above 800°C can improve the resistance of the porcelain glaze layer to cold and heat shocks compared to low-temperature firing, thereby avoiding the porcelain glaze layer from bursting or cracking due to sudden temperature changes.

[0065] The embodiments of the present invention are described in detail above, but the present invention is not limited to the described embodiments. It is apparent to those skilled in the art that various changes, modifications, substitutions, and variations of these embodiments may be made without departing from the principles and spirit of the present invention, and the changes still fall within the scope of protection of the present invention.

Claims

1. A microwave-safe enamelware, characterized by: It comprises a metal base and a first glaze layer, a second glaze layer and a third glaze layer which are sequentially coated and fired on the surface of the metal base; By mass percentage, The raw materials of the first glaze layer contain: titanium dioxide 1-5%, silicon dioxide 40-55%, zirconium dioxide 2-5%, boron trioxide 30-40%, aluminum trioxide 3-5%, cobalt oxide 2-3%, nickelous oxide 2-3%; The raw materials of the second glaze layer contain: titanium dioxide 1-5%, silicon dioxide 48-50%, zirconium dioxide 3-5%, boron trioxide 35-40%, aluminum oxide 4-5%; The raw materials of the second glaze layer include: titanium dioxide 1-5%, silicon dioxide 48-50%, zirconium dioxide 3-5%, boron trioxide 35-40%, and aluminum oxide 4-5%.

2. The microwaveable enamel container according to claim 1, characterized in that: In terms of mass percentage, the carbon content of the metal matrix is ​​0.01-0.1%.

3. A method for preparing enamelware that can be placed in a microwave oven, characterized in that: The preparation method is used to produce a microwave-safe enamel ware according to any one of claims 1 to 2, and the preparation method comprises the following steps: S1, according to the ingredients ratio, the raw materials containing titanium dioxide, silicon dioxide, zirconium dioxide, boron trioxide, aluminum trioxide, cobalt oxide, and nickelous oxide are charged into a ball mill, water is added, and they are ground and mixed to obtain glaze slip A; the raw materials containing titanium dioxide, silicon dioxide, zirconium dioxide, boron trioxide, and aluminum trioxide are charged into a ball mill, water is added, and they are ground and mixed to obtain glaze slip B; S2: Immerse the metal substrate in glaze slurry A for the first glazing. After soaking, remove the metal substrate and shake the slurry evenly on the surface of the metal substrate. Then, dry it at 100-200°C for 10-30 minutes, then fire it at 820-850°C for 3-5 minutes. After firing, let it cool at room temperature to form the first glaze layer, thus obtaining semi-finished product A. S3, immerse semi-finished product A in glaze slurry B for a second glazing. After immersion, take out the semi-finished product A and shake the slurry evenly. Then, dry it at 100-200℃ for 10-30 minutes, then fire it at 810-830℃ for 3-5 minutes. After firing, let it cool at room temperature to form a second glaze layer, thus obtaining semi-finished product B. S4, immersing the semi-finished product B in the glaze slurry B for the third glazing, taking it out after immersion and shaking the slurry on the surface of the semi-finished product B evenly, then drying it at 100-200°C for 10-30 minutes, and then firing it at 800-820°C for 3-5 minutes. After firing, it is placed at room temperature to cool to form a third glaze layer, thereby obtaining the enameled vessel.

4. The method for preparing a microwaveable enamel ware according to claim 3, characterized in that: In step S1, after the glaze slurry A is ground and mixed, the weight of the residue after screening through a 200-mesh sieve is 2-6 g, and the specific gravity of the slurry is controlled at 1.65-1.

75.

5. The method for preparing a microwaveable enamel ware according to claim 3, characterized in that: In step S1, after the glaze slurry B is ground and mixed, the weight of the residue after screening through a 200-mesh sieve is 2-4 g, and the specific gravity of the slurry is controlled at 1.55-1.65.

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