JPH0337101B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD The present invention relates to a new configuration of a wall material inside a household high-frequency heating device with a heater, that is, a microwave oven. The present invention relates to a high-frequency heating device with a built-in heater that is inexpensive, available in a wide variety of colors, does not easily stain walls, and has excellent durability. Conventional technology Conventionally, stainless steel or aluminum has been used as the oven wall material for this type of high-frequency heating device, or a steel plate treated with enamel has been used, but these have the drawbacks of high cost and limited color tones. Ta. In the case of single-function microwave ovens, materials such as galvanized iron plates are used and painted. In this case, the paint used is melamine/acrylic resin paint, epoxy resin paint, etc.
These organic paints have a heat resistance of 120 to 130 degrees Celsius at most, so in a high-frequency heating device with a heater, the oven wall temperature is 250 to 300 degrees Celsius, and the temperature near the heater is 500 to 300 degrees Celsius.
It could not be applied because the temperature rose to 600℃. In addition, in the case of enamel, the color tone is limited to black due to adhesion to the base material and concealability.
There are products that have a self-cleaning function by dispersing oxidation catalysts in the parts, but they are not widely applied because they are ineffective in low-temperature parts, and the heat treatment temperature is high and the plates are easily deformed. I haven't reached it yet. Problems to be solved by the invention Instead of stainless steel, which has been used exclusively in the past, it is possible to use inexpensive materials such as iron plates and aluminum-plated steel plates and apply heat-resistant coatings. Based on the usage of the high-frequency heating device, the properties required of the oven wall material include the following conditions. (1) The coating must be hard and scratch-resistant. In particular, the surface should not be scratched even if rubbed with an enamel plate. There should be no scratches on the sliding surface of the turntable. (2) It should have excellent heat resistance and thermal shock resistance, especially when considering the vicinity of the heater, it should have heat resistance of about 600℃. (3) Good stain resistance against food and seasonings;
In particular, there should be no deterioration of the coating film during heating or high-frequency heating. (4) Excellent paintability. It is possible to paint even in the box state, and if possible, electrostatic painting is possible to enhance the painting effect. (5) It must be possible to wear a bright color that matches the image of the interior wall of the cooking cabinet. (6) Of course, there should be no problems with corrosion resistance, steam resistance, and other general coating film properties. It is necessary to satisfy the above conditions. However, in the past, there was no such thing at all. Means for Solving the Problems In order to satisfy the above-mentioned conditions, the present invention provides an oven of a high-frequency heating device with a built-in heater on a metal substrate and a polyborosiloxane resin and a polyether sulfonate resin on the substrate as necessary. A resin layer is formed by applying a paint containing a fluororesin and baking it. Function Iron plates, aluminum plated steel plates, stainless steel/iron clad plates, zinc/aluminum alloy plated steel plates, etc. are used as metal base materials. Polyborosiloxane resins are, for example, The main component is a semi-inorganic polymer having the following structure. This binder has the characteristics of a "semi-inorganic polymer" and has properties similar to organic polymers at room temperature, making it excellent in terms of operability when used in coatings, etc. When heated, the organic content decomposes to form Si,
Ceramic is formed using B and O as the skeleton. Complete ceramicization takes place at 600°C. Polyborosiloxane resin is produced by using diphenyldichlorosilane as a starting material, adding boron hydroxide, hydrochloric acid, water, boric acid, etc. to perform a dehydrochloric acid reaction, and adding hydroquinone etc. to polymerize it into a polymer with a molecular weight of several thousand. used. Polyether sulfone resin is a heat-resistant thermoplastic resin developed by ICI Ltd. in the UK, but it can also be used as a paint by dissolving it in a polar solvent such as n-methylpyrrolidone. Although polyether sulfone resin is a resin that is poorly compatible with other resins, the present inventors have discovered that good physical properties can be obtained when used in combination with polyborosiloxane resin. Both resins are used in the coexistence of a solvent such as n-methylpyrrolidone to create a paint in which pigments, fillers, etc. can be dispersed.
The coating film obtained by baking for 10 minutes at ℃, 10 minutes at 200℃, and 10 minutes at 380℃ has a pencil hardness of about 5H, exhibits extremely excellent drawing workability, and can be bent to a T-bend.
Shows excellent processability with no cracks in IT.
Although this coating film has good food stain resistance as it is, it exhibits excellent non-stick properties by incorporating fluororesin together with a surfactant. Due to the heat resistance of the polyborosiloxane resin, this coating film maintains its adhesion even when heated to 600°C. The high processability of this coating film is thought to be based on the fact that the polyether sulfone resin is a linear polymer. Embodiments Hereinafter, embodiments of the present invention will be described based on the accompanying drawings. FIG. 1 is a perspective view of the main body 1 of the high-frequency heating device with a heater with the door 3 open, and 2 in the figure is an oven. As shown in the cross-sectional view of main parts in FIG. 2, this oven 2 is made of polyborosiloxane resin and polyether sulfonate resin, which completely covers a fabric 2b formed into an oven shape and made of low-cost aluminum-plated steel plate. It is composed of a coating film 2a of threads coated with fluororesin. The oven 2 is formed by processing a base metal such as an aluminum-plated steel plate into an oven shape using methods such as press working and spot welding. Next, after degreasing and other treatments are applied to the oven-shaped base material,
Apply polyborosiloxane resin-polyethersulfone resin paint. After painting, 10 minutes at 100℃,
It is finished by firing at 200℃ for 10 minutes and then at 380℃ for 10 minutes. In the oven of the present invention, as another method, a polyborosiloxane resin or a polyether sulfone resin is applied to a plate-shaped substrate such as an aluminum-plated steel plate.
- Precoat obtained by applying a paint obtained by dispersing pigments, fillers, etc. in the coexistence of a solvent such as methylpyrrolidone to a film thickness of 10 to 30 μm, and then baking at a maximum temperature of 380 to 400°C for 20 to 30 minutes. It can also be obtained by processing a steel plate by curling, seamer processing, single-sided spot welding, etc. This paint can be obtained by the following procedure. The polyborosiloxane resin used is an inorganic polymer "SMP-32" synthesized by Showa Electric Cable Co., Ltd. It contains about 30% by weight polymer and filler, 5% by weight silica and 5% by weight magnesium oxide in n-methylpyrrolidone solvent. For 100 parts by weight of this resin, add polyether sulfone resin [5003P, released by Sumitomo Scientific Co., Ltd.].
20 parts by weight, 10 parts by weight of "Luburon L-2" manufactured by Daikin Industries, Ltd. as a fluororesin, 100 parts by weight of n-methylpyrrolidone, 60 parts by weight of titanium oxide,
Using an attritor with 50 parts by weight of toluene, the mixture is dispersed and mixed for 24 hours to obtain a paint. The blending ratio of polyether sulfone resin to polyborosiloxane resin is 1/1 to 10/1 by weight.
1 is valid. In particular, a range of 2/1 to 3/1 is optimal. The optimal blending amount of the fluororesin is 5 to 15% by weight based on the polyborosiloxane resin. In particular, the addition of fluororesin improves food contamination during microwave heating. In terms of food contamination, the contamination of kechiap, cola, soybean oil, etc. can be improved by adding fluororesin. This is considered to be based on the water repellency of the fluororesin. Various heat-resistant pigments can be used for the purpose of coloring. The weight ratio of the pigment is 5 to 80 parts by weight per 100 parts by weight of the polyborosiloxane resin.
Parts by weight are appropriate. The particle size is preferably 1 μm or less. Particle size exceeds 1μm and blending ratio is 80
This is because the coating film becomes porous when the weight part is exceeded.
This is because food contamination becomes worse. Now, the film performance of the oven coated with the above paint and baked is good as shown below.

[Table] The coating film is particularly smooth and slippery, so it is difficult to coat glass dishes,
Even if you rub the surface with an enamel plate, it will not be easily scratched. Regarding paints other than this paint, silicone-based paints exhibit reduced adhesion and yellowing at around 300°C. In addition, polyamide and imide-based materials have low heat resistance.
The temperature is around 280℃, and the acid resistance and steam resistance are poor. In addition, fluorine-based materials are soft with a hardness of 2H and have poor adhesion to the base material. Polyether sulfone type
It turns yellow after about 200 to 300 hours at 300℃.
In addition, inorganic materials such as silicates and phosphates have poor paintability, and the coating film contains pinholes, resulting in poor corrosion resistance. In treatments such as enamel, the thicker the film, the poorer the heat shock and steam resistance. Further, since the firing temperature is high, there are problems such as the oven being easily deformed. Effects of the Invention As described above, since the high-frequency heating device of the present invention is a heat-resistant coating applied to the metal base material forming the oven, (1) it is cheaper than conventional stainless steel; (2) It does not discolor due to temperature like stainless steel, and
Since the coating is non-adhesive, food contaminants do not stick to it and are easy to wipe off, making it hygienic. (3) The interior of the refrigerator is colorful because it can be colored as desired. (4) Do not use spot welding for pre-painted steel sheets. Oven processing is possible. As described above, an extremely practical oven can be obtained.

[Brief explanation of drawings]

FIG. 1 is a perspective view of the high-frequency heating device with the door open, and FIG. 2 is an enlarged sectional view of the main parts of the present invention. 2...Oven, 2b...Metallic base, 2a...
...Resin layer.

Claims (1)

[Claims] 1. A resin layer made by applying a paint containing polyborosiloxane resin and polyether sulfon resin to a metal base forming the oven of a high-frequency heating device with a built-in heater, and baking the paint. High frequency heating device with formed oven. 2. A resin layer was formed by applying a paint containing polyborosiloxane resin, polyether sulfone resin, and fluororesin to the metal base that forms the oven of a high-frequency heating device with a built-in heater, and baking the paint. High frequency heating device equipped with an oven.